Ändra sökning
Avgränsa sökresultatet
1234567 1 - 50 av 3123
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Aagaard, Annabeth
    et al.
    Aarhus University, Dept. Business Development & Technology.
    Ritzén, Sofia
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Integrerad produktutveckling.
    Creating and capturing sustainable value through business model and service innovation2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    A number of researchers and practitioners emphasize the potentials of creating value through sustainable business models. However, little attention has been paid as to how sustainable value is created and implemented into the organization and how sustainable value is perceived by the customers. This research gap is explored empirically through a case study of active facilitation and implementation of sustainable business models as experience internally and externally among two hotels’ employees and customers. The findings reveal different key control mechanisms in sustainable value creation and value capture through sustainable business models and sustainable service innovation. The managerial implications of creating and implementing sustainable business models in ways that are perceived sustainable by customer, stress the need for employee engagement, customer involvement, and targeted and personal communication educating internal and external sustainability ambassadors.

  • 2.
    Abbasi, Abdul Ghafoor
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Muftic, Sead
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    CryptoNET: Security Management Protocols2010Ingår i: ADVANCES IN DATA NETWORKS, COMMUNICATIONS, COMPUTERS / [ed] Mastorakis, NE; Mladenov, V, ATHENS: WORLD SCIENTIFIC AND ENGINEERING ACAD AND SOC , 2010, s. 15-20Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper we describe several network security protocols used by various components of CryptoNET architecture. The protocols are based on the concept of generic security objects and on well-established security standards and technologies. Distinctive features of our security protocols are: (1) they are complete in terms of their functionality, (2) they are easy to integrate with applications, (3) they transparently handle security credentials and protocol-specific attributes using FIPS 201 (PIV) smart cards, and (4) they are based on generic security objects. These protocols are: remote user authentication protocol, single-sign-on protocol, SAML authorization protocol, and secure sessions protocol. Security protocols use our Security Provider as a collection of cryptographic engines implemented either in software or using FIPS 201 (NV) smart cards. It also manages protocols' attributes using security applets stored in Ply smart card.

  • 3.
    Abbasi, S.
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Particle emissions from rail vehicles: A review2012Ingår i: Civil-Comp Proceedings, ISSN 1759-3433, Vol. 98Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Emission of airborne particles is a side effect from rail transport. This paper reviews recent research on particle emissions from rail vehicles. Both exhaust and non-exhaust particle emissions are characterized by size, morphology, composition, and size distribution. Current legislation, knowledge of adverse health effects, and available and proposed solutions for emission reductions are also treated. There has been much focus on exhaust emissions, but only a few limited studies have investigated non-exhaust particle emissions, which contain a significant amount of metallic materials. A new method for measuring the airborne wear particle emission rate (AWPER) is proposed as a first step to guide new legislations and to focus further research on non-exhaust airborne emission, i.e., research on the generation mechanisms for particle emissions and their adverse health effects. 

  • 4.
    Abbasi, Saeed
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    A comparison between particle characteristics between two railway brake pads2013Rapport (Övrigt vetenskapligt)
  • 5.
    Abbasi, Saeed
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    A study of nanostructured particles in railway tunnels2013Rapport (Övrigt vetenskapligt)
  • 6.
    Abbasi, Saeed
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Characterisation of airborne particles from rail traffic2011Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Since the investigation of wear particles in rail transport started in late-1910s, the high mass concentration of these particles has raised worries among researchers concerned with air quality. However, effective action has yet to be taken because of lack of relevant knowledge. This thesis provides applicable information for the airborne wear particles in rail transport. Some aspects of their characteristics such as diameter size, mass concentration, number concentration, and morphology of particles were investigated in field tests and laboratory tests.The effects on particle characterisations from different operational conditions in the field tests, and applying different braking materials, conducting tests in different applied loads or sliding velocities in the laboratory tests were studied. The main advantage of conducting laboratory tests was to focus on studying particles from one source. The possibility of repetition, using high sensitive instruments and conducting tests at low costs are the other advantages of laboratory studies. Paper A describes how a pin-on-disc machine was used to reproduce similar real operational conditions during mechanical braking in a train. The results were validated by comparing the field tests results with the laboratory studies. The particles morphology and size distribution were also studied.Paper B presents a summary of field tests results. The effects of curve negotiating and applying braking in different real conditions were investigated with an on-board measurement.The element composition of the particles and their potential sources were also investigated outside of the particles morphologies.Paper C presents comprehensive results from laboratory studies on airborne particles from different braking materials. The differences in the particle characteristics in similar test conditions were attributable to different material compositions and dominant wear mechanisms. A new index was introduced in this paper and is suggested to be used as a qualitative factor with regard to the airborne wear particle emission rate.Paper D is a review of the recent studies of exhaust emission and non-exhaust emission from rail vehicles. A summary of results, measurements, adverse health effects, and proposed or applied solutions are reviewed in this paper.

  • 7.
    Abbasi, Saeed
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Nanostructured particles in/outside compartment of running train, an on board measurement2013Rapport (Övrigt vetenskapligt)
  • 8.
    Abbasi, Saeed
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Non-exhaust Nano particle emission in Rail traffic2010Konferensbidrag (Refereegranskat)
  • 9.
    Abbasi, Saeed
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Towards elimination of airborne particles from rail traffic2013Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Since the investigation of wear particles from rail transport started in the late 1910s, the high mass concentrations of these particles have prompted concern among researchers interested in air quality. However, effective action has yet to be taken because relevant knowledge is still missing. This thesis provides knowledge of airborne wear particles originating from rail transport. Some aspects of their characteristic parameters, such as size, mass concentration, number concentration, and morphology, were investigated in the field and in laboratory tests. We also discuss means to mitigate non-exhaust emissions, as well as the advantages and disadvantages of various test set-ups in the seven appended journal papers:Paper A reviews recent studies of exhaust and non-exhaust emissions from rail vehicles. The results, measurements, adverse health effects, and proposed or applied solutions presented in this literature are summarized in this paper.Paper B summarizes the results of field tests we conducted. The effects of curve negotiation and braking under different real conditions were investigated in a field test in which on-board measurements were made. The elemental composition and morphology of the particles emitted and their potential sources were also investigated.Paper C describes how a pin-on-disc machine can be used to reproduce real operating conditions during mechanical train braking in a controlled laboratory setting. The results were validated by comparing the field test results with the results of laboratory studies.Paper D presents comprehensive results of laboratory studies of airborne particles from different braking materials. A new index is introduced in this paper, which can be used as a quantitative metric for assessing airborne wear particle emission rates.Paper E describes the effects of using various friction modifiers and lubricants on the characteristics of airborne particles from wheel–rail contact under lubricated and unlubricated conditions.Paper F reports work to simulate thermoelastic instability in the cast-iron braking material. We simulated the fluctuation of the flash temperature by considering the temperature dependency of the material properties and the transformation of the contact state due to thermomechanical phenomena and wear.Paper G reviews new full- and sub-scale measurements of non-exhaust emissions from ground transport. The advantages and disadvantages of on-board measurements, pin-on-disc tests, dynamometer tests, and test rig studies are discussed in this paper.

  • 10.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Ekstrand-Hammarström, Barbara
    Division of CBRN Defence and Security, Swedish Defence Research Agency (FOI),.
    Bergström, Ulrika
    Division of CBRN Defence and Security, Swedish Defence Research Agency (FOI),.
    Bucht, Anders
    Deptartment of Public Health and Clinical Medicine, Umeå University Hospital, Umeå, 901 89, Sweden.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Jansson, Anders
    Department of Applied Environmental Science, Stockholm University, Stockholm, 106 91, Sweden.
    Biological response in lung cells by brake dust from a novel set-up to generate one sourcewear particles2013Konferensbidrag (Refereegranskat)
  • 11.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Jansson, Anders
    Stockholm University, Applied Environmental Science, Stockholm, Sweden.
    Olander, Lars
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Installationsteknik.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    A pin-on-disc study of the rate of airborne wear particle emissions from railway braking materials2012Ingår i: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 284, s. 18-29Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The current study investigates the characteristics of particles generated from the wear of braking materials, and provides an applicable index for measuring and comparing wear particle emissions. A pin-on-disc tribometer equipped with particle measurement instruments was used. The number concentration, size, morphology, and mass concentration of generated particles were investigated and reported for particles 10 nm-32 mu m in diameter. The particles were also collected on filters and investigated using EDS and SEM. The effects of wear mechanisms on particle morphology and changes in particle concentration are discussed. A new index, the airborne wear particle emission rate (AWPER), is suggested that could be used in legislation to control non-exhaust emissions from transport modes, particularly rail transport.

  • 12.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Jansson, Anders
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Particle emissions from rail traffic: a literature review2013Ingår i: Critical reviews in environmental science and technology, ISSN 1064-3389, E-ISSN 1547-6537, Vol. 43, nr 23, s. 2211-2244Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Particle emissions are a drawback of rail transport. This work is a comprehensive presentation of recent research into particle emissions from rail vehicles. Both exhaust and non-exhaust particle emissions are considered when examining particle characteristics such as  PM10, and PM2.5 concentration levels, size, morphology, composition, as well as adverse health effects, current legislation, and available and proposed solutions for reducing such emissions. High concentration levels in enclosed rail traffic environments are reported and some toxic effects of the particles. We find that only a few limited studies have examined the adverse health effects of non-exhaust particle emissions and that no relevant legislation exists. Thus further research in this area is warranted.

  • 13.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Moslemi, Kianoush
    A new approach for optimization of heating system in tank wagons2003Konferensbidrag (Refereegranskat)
  • 14.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olander, Lars
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Installationsteknik.
    Larsson, Christina
    Bombardier Transportation Sweden AB, Västerås, Sweden.
    Jansson, Anders
    Stockholm University, Applied Environmental Science, Stockholm, Sweden.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Tribologi.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    A field test study of airborne wear particles from a running regional train2012Ingår i: IMechE, Part F: Journal of Rail and Rapid Transit, ISSN 0954-4097, Vol. 226, nr 1, s. 95-109Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Inhalable airborne particles have inverse health affect. In railways, mechanical brakes, the wheel–rail contact, current collectors, ballast, sleepers, and masonry structures yield particulate matter. Field tests examined a Swedish track using a train instrumented with particle measurement devices, brake pad temperature sensors, and speed and brake sensors. The main objective of this field test was to study the characteristics of particles generated from disc brakes on a running train with an on-board measuring set-up.

    Two airborne particle sampling points were designated, one near a pad–rotor disc brake contact and a second under the frame, not near a mechanical brake or the wheel–rail contact; the numbers and size distributions of the particles detected were registered and evaluated under various conditions (e.g. activating/deactivating electrical brakes or negotiating curves). During braking, three speed/temperature-dependent particle peaks were identified in the fine region, representing particles 280 nm, 350 nm, and 600 nm in diameter. In the coarse region, a peak was discerned for particles 3–6 μm in diameter. Effects of brake pad temperature on particle size distribution were also investigated. Results indicate that the 280 nm peak increased with increasing temperature, and that electrical braking significantly reduced airborne particle numbers. FESEM images captured particles sizing down to 50 nm. The ICP-MS results indicated that Fe, Cu, Zn, Al, Ca, and Mg were the main elements constituting the particles.

     

  • 15.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    A study of friction modifiers on airborne wear particles from wheel-rail contact2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Wheel-rail contact and its wear process are crucial issues in maintenance and operating of rolling stocks. During wheel-rail contact, materials in mating faces are worn off and some of them transferred to airborne particles. Eventhough the wear process in wheel-rail contact are well-known, few studies have been conducted on the airborne particles from wheel-rail contact.

    The purpose of this study is to investigate the effect of using different friction modifier on the amount of airbotne particles from wheel-rail contact in a laboratory simulation. In this regard, a series laboratory tests were used by using round head pin (R=25mm) and dead weight 40 N in a pin-on-disc machine. This set-up simulates a contact pressure around 750 MPa on the pin head.

    The amount of airborne particles and their characteristics were investigated in dry-contact, and non-dry contacts whereas a lubricant, Binol rail 510 and a friction modifier, tramsilence were used. According to the results, the effects of using Binol rail to reduce the amount of airborne particles were considerable.

  • 16.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Airborne wear particles from train traffic2010Konferensbidrag (Refereegranskat)
  • 17.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Experiences of measuring airborne wear particles from braking materials and the wheel - Rail contact2012Ingår i: 9th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems, CM 2012, Southwest Jiaotong University , 2012, s. 608-609Konferensbidrag (Refereegranskat)
    Abstract [en]

    During braking both of the discs and pads of disc brakes are worn. Since disc brakes are not sealed, some of the generated wear particles can become airborne. The same condition also holds for block brakes utilized in rail vehicles. Furthermore, the wheel-rail contact is also subjected to wear processes during braking as well as during normal running. This contact also contributes to generation of airborne particles. Several studies have found an association between adverse health effects and the concentration of particles in the atmosphere, so it is of interest to improve our knowledge of the airborne wear particles. The present work includes results from full scale testing of rail vehicles. Particle size distribution, morphology and elemental contents are presented and discussed. Due to high back ground concentration levels in field tests, dedicated laboratory test set ups on a reduced scale were designed and utilized for airborne particle studies with zero background level. Promising correlation between field test and the lab set up is identified. Different ways of using this test set up for evaluating how the composition of the airborne particles is classified with respect to their health effects are discussed. Furthermore, different ways of using the proposed method to rank and to quantify airborne particle emission factors are presented.

  • 18.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Experiences of measuring airborne wear particles from braking materials and wheel-rail contact2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    During braking both of the discs and pads of disc brakes are worn. Since disc brakes are not sealed, some of the generated wear particles can become airborne.  Wheel-rail is also subjected to wear process during braking as well as normal running. They also contribute to generate airborne particles. Several studies have found an association between adverse health effects and the concentration of particles in the atmosphere, so it is of interest to improve our knowledge of the airborne wear particles generated by disc brakes.

    The present work includes results from full scale testing of rail vehicles. Particle size distribution, morphology and elemental contents are presented and discussed for different combinations of disc and pad materials. Due to high back ground concentration levels in field tests, dedicated laboratory test set ups on a reduced scale were designed and utilized for airborne particle studies with zero background level.

    Promising correlation between field test and the lab set up is identified. Different ways of using this test set up for evaluating how the composition of the airborne particles is classified with respect to their health effects are discussed. Furthermore, different ways of using the proposed method to rank and to quantify airborne particle emission factors are presented.

  • 19.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Lack of applicable criteria in non-exhaust emission legislation: AWPER index a practical solution2011Konferensbidrag (Refereegranskat)
  • 20.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olander, Lars
    A field investigation of the size and morphology and chemical composition of airborne particles in rail transport2010Konferensbidrag (Refereegranskat)
  • 21.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olander, Lars
    Larsson, christina
    A field investigation of the size, morphology and chemical composition of airborne particles in rail transport2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    The health effects of inhalable airborne particles are well documented. In the European Union the European Council mandates that the level of airborne particles with a diameter smaller than 10 µm (PM10) must not exceed an annual average of 40 µg/m3. Examples of possible sources from rail transport are mechanical brakes, wheel rail contact, current collectors, ballast, sleepers and masonry structures. In this regard, a series of field tests have been conducted on a regular Swedish track using a regional train instrumented with: particle measurement devices, temperature sensors in brake pads and sensors to measure the magnitude of train speed and a GPS.

    Two sampling points for airborne particles were designated in the train under frame. One of the sampling points was near a pad to rotor disc brake contact and a second global sampling point was chosen under the frame, but not near a mechanical brake or the wheel-rail contact. The first one was highly influenced by brake pad wear debris and the other one was influenced by all of the brake pads, wheel and rail wear debris as well as re-suspension. In each sampling points, three tubes were linked to three particle measurement devices. Two sets of Ptrak, Dustrak and Grimm devices were used. The Ptrak 8525 was an optical particle measurement device which could measure particle diameter in the size interval of 20 nm up to 1 micrometer. The Dustrak was used to measure particle mass concentration. The Grimm 1.109 was an aerosol spectrometer which counted number of particles from 0.25 micrometer to 32 micrometer in 31 intervals. These two Grimm devices were equipped with Millipore filters in the devices outlets to capture particles for further studies on morphology and matter of particles.

    The total number and size distribution of the particles for these two sampling points were registered and evaluated in different situations such as activating and deactivating electrical brake or train curve negotiating.

    During braking, three peaks of 250 nm, 350 nm and 600 nm in diameter, with the 350 nm peak dominating were identified in the fine particle region. In the coarse particle region, a peak of around 3-6 µm in diameter was discovered. The brake pad temperature effects on particle size distribution were also investigated and the results showed that the peak around 250 nm increased. Furthermore, the activation of electrical braking significantly reduced the number of airborne particles.

    A SEM was used to capture the images from collected particles on filters. Furthermore, an ICP-Ms method was used to investigate the elemental contents of the particulates on the filter.  In this case the main contribution belonged to Fe, Si, Al, Ca, Cu, Zn. The higher amount of some elements weights such as calcium, silicon, sodium and aluminum in the global sampling point filters revealed that ballast and concrete sleepers were the main sources for these particles although some of them originated from rail, wheel, brake disc and brake pad as well.

  • 22.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Tritscher, Trosten
    TSI.
    Krinke, Thomas
    TSI.
    On-board study of nano- and micrometer-particle characteristics of a running electric train2013Konferensbidrag (Refereegranskat)
  • 23.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Zhu, Yi
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Pin-on-disc study of the effects of railway friction modifiers on airborne wear particles from wheel-rail contact2013Ingår i: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 60, s. 136-139Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Knowledge of wheel–rail interaction is crucial to wheel and rail maintenance. In this interaction, some of theworn-off material is transformed into airborne particles. Although such wear is well understood, few studiestreat the particles generated. We investigated friction modifiers' effects on airborne particles characteristicsgenerated in wheel-rail contacts in laboratory conditions. Pin-on-disc machine testing with a round-head pinloaded by a dead weight load 40 N simulated maximum contact pressure over 550 MPa. Airborne particlecharacteristics were investigated in dry contacts and in ones lubricated with biodegradable rail grease andwater- and oil-based friction modifiers. The number of particles declined with the grease; the number ofultrafine particles increased with the water-based friction modifier, mainly due to water vaporization.

  • 24.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Particle emission from rail vehicles: A literature review2012Ingår i: Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, Sage Publications, 2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Emission of airborne particles is a side effect from rail transport. This work reviews recent research on particle emissions from rail vehicles. Both exhaust and non-exhaust particle emissions are characterized by size, morphology, composition, and size distribution. Current legislation, knowledge of adverse health effects, and available and proposed solutions for emission reductions are also treated. There has been much focus on exhaust emissions, but only a few limited studies have investigated non-exhaust particle emissions, which contain a significant amount of metallic materials. A new method for measuring the airborne wear particle emission rate (AWPER) is proposed as a first step to guide new legislations and to focus further research on non-exhaust airborne emission, i.e., research on the generation mechanisms for particle emissions and their adverse health effects.

  • 25.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Technical note: Experiences of studying airborne wear particles from road and rail transport2013Ingår i: Aerosol and Air Quality Research, ISSN 1680-8584, Vol. 13, nr 4, s. 1161-1169Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Airborne particles and their adverse effects on air quality have been recognized by humans since ancient times. Current exhaust emission legislations increase the relative contribution of wear particles on the PM levels. Consequently, wearbased particle emissions from rail and road transport have raised concerns as ground transportation is developing quickly. Although scientific research on airborne wear-based particles started in 1909, there is almost no legislation that control the generation of wear-based particles. In addition, there is no accepted and approved standard measurement technique for monitoring and recording particle characteristics. The main objective of this study is to review recent experimental work in this field and to discuss their set-ups, the sampling methods, the results, and their limitations, and to propose measures for reducing these limitations.

  • 26.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement. Department of Mechanical engineering, Golpayegan University of Technology.
    Teimourimanesh, Shahab
    Chalmers.
    Vernersson, Tore
    Chalmers.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Lunden, Roger
    Chalmers.
    Temperature and Thermoelastic Instability at Tread Braking Using Cast Iron Friction Material2013Ingår i: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 314, nr 1–2, s. 171-180Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Braking events in railway traffic often induce high frictional heating and thermoelastic instability (TEI) at the interfacing surfaces. In the present paper, two approaches are adopted to analyse the thermomechanical interaction in a pin-on-disc experimental study of railway braking materials. In a first part, the thermal problem is studied to find the heat partitioning between pin and disc motivated by the fact that wear mechanisms can be explained with a better understanding of the prevailing thermal conditions. The numerical model is calibrated using the experimental results. In a second part, the frictionally induced thermoelastic instabilities at the pin-disc contact are studied using a numerical method and comparing them with the phenomena observed in the experiments. The effects of temperature on material properties and on material wear are considered. It is found from the thermal analysis that the pin temperature and the heat flux to the pin increase with increasing disc temperatures up to a transition stage. This agrees with the behaviour found in the experiments. Furthermore, the thermoelastic analysis displays calculated pressure and the temperature distributions at the contact interface that are in agreement with the hot spot behaviour observed in the experiments.

  • 27.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Teimourimanesh, Shahab
    Chalmers.
    Vernersson, Tore
    Chalmers.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Lunden, Roger
    Chalmers.
    Temperature and thermo-elastic instability of tread braking friction materials2012Konferensbidrag (Refereegranskat)
  • 28.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Wahlström, Jens
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olander, Lars
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Installationsteknik.
    Larsson, Christina
    Bombardier Transportation Sweden AB, Västerås, Sweden.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Tribologi.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    A study of airborne wear particles generated from organic railway brake pads and brake discs2011Ingår i: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 273, nr 1, s. 93-99Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Brake pads on wheel-mounted disc brakes are often used in rail transport due to their good thermal properties and robustness. During braking, both the disc and the pads are worn. This wear process generates particles that may become airborne and thus affect human health. The long term purpose of ‘Airborne particles in Rail transport’ project is to gain knowledge on the wear mechanisms in order to find means of controlling the number and size distribution of airborne particles. In this regard, a series of full-scale field tests and laboratory tests with a pin-on-disc machine have been conducted. The morphology and the matter of particles, along with their size distribution and concentration, have been studied. The validity of results from the pin-on-disc simulation has been verified by the field test results. Results show an ultra-fine peak for particles with a diameter size around 100 nm in diameter, a dominant fine peak for particles with a size of around 350 nm in diameter, and a coarse peak with a size of 3-7 μm in diameter. Materials such as iron, copper, aluminium, chromium, cobalt, antimony, and zinc have been detected in the nano-sized particles.

  • 29.
    Abdo, Nawar
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Modularization and evaluation of vehicle’s electrical system2019Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Modularisering är en strategi som används av många företag, för att hjälpa dem att erbjuda sina kunder en mängd olika anpassade produkter på ett effektivt sätt. Detta görs genom anpassning av olika oberoende moduler, som är kopplade med standardiserade gränssnitt som utnyttjas av alla modulvarianterna. Scania, som är ett av de stora företagen som erbjuder modulariserade produkter, har framgångsrikt förbättrat sina modulariseringskoncept under många år och är ett av de mest ikoniska företagen närdet gäller modularisering av bussar, lastbilar och motorer. Men med det ökande behovet av elektronik integrerad i fordonen blir det allt viktigare att modularisera det elektriska systemet.

    Det finns för närvarande en befintlig, modulär produktarkitektur för det elektriska systemet, och Scania vill veta hur väl modulariserat det är, eftersom det inte finns något enat sätt som anger vad som anses vara den bättre lösningen. För att analysera det elektriska systemets nuvarande tillstånd, måste en systematisk metod förmodularisering användas, vilket skulle hjälpa till att svara på tre viktiga frågor: Är modulerna väldefinierade? Finns det ett sätt att systematiskt jämföra alternativa lösningar? Vilka kriterier är viktigare att fokusera på?

    Eftersom det inte finns något enhetligt sätt att modularisera har många modulariseringsmetoder skapats, och var och en har optimerats för ett visst ändamål. I projektet jämförs tre olika modulariseringsmetoder och använder sedan en av de metoder som anses vara den föredragna metoden för att hjälpa till att ge svaren som företaget söker när man undersöker modulariteten hos det elektriska systemet.

    Eftersom det elektriska systemet är väldigt komplext och projektet har begränsat antal resurser beslutades det att välja en av kontrollenheterna som ett exempel, vilket var APS (luftbehandlingssystem). Litteraturstudien visade att den mest givande metoden att använda var MFD (Module FunctionDeployment), eftersom det ger mer information om produkten och vilka kriterier företaget ska fokusera på. Det bestämdes sedan att använda de relevanta stegen i MFD för att analysera APS tillståndet som ett exempel på hur den här metoden fungerar.

  • 30.
    Abdullah, Maizura Ailin
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Integrerad produktutveckling.
    Öhrwall Rönnbäck, A
    Ölundh Sandström, Gunilla
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Integrerad produktutveckling.
    Building Networks for Delivering Integrated Product-Service Offerings (IPSOs)2010Konferensbidrag (Refereegranskat)
  • 31.
    Abedi, Aref
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Wallsten, Jakob
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Beslutsfattande inom Produktutveckling: Kartläggning, analysering & vidareutveckling av PPM process på ett medtech företag2009Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Mängden idéer hos innovativa företag brukar vanligen överskrida de tillgängliga resurserna. Detta gäller

    även idéer för att utveckla nya produkter. Eftersom företagen inte kan välja att utveckla alla idéer så

    måste de kunna välja emellan dessa. Detta innebär att kunna ta beslut gällande start och stop av ett

    projekt samt att kunna prioritera mellan pågående och framtida projekt.

    Projektportföljshantering (PPM) är en organisatorisk process med syfte att systematiskt organisera och

    driva verksamhet som syftar till att utvärdera, välja och prioritera idéer och projekt för att utveckla nya

    produkter. PPM inkluderar fyra viktiga mål som skall uppfyllas; maximera värdet av portföljen, att

    uppnå en balanserad portfölj, uppnå en strategisk riktning och driva rätt antal projekt.

    Syftet med examensarbetet var att utveckla en mer visuell och formell PPM process för tidiga skeden i

    produktutvecklingen, detta på en specifik avdelning på St Jude Medical AB, Sverige.

    Examensarbetet har utförts genom att följa en metodik vid namn Process Modules. Metodiken är ett

    förhållningssätt för att utveckla en PPM process som passar ett specifikt företag. Metoden är inte en

    fastställd arbetsordning för beslutsfattande, utan en systematisk metod för att utveckla en.

    Examensarbetet har utförts i nära samarbete med en definierad arbetsgrupp bestående av sex

    beslutsfattare på St Jude Medical AB, Sverige. I ett tidigt stadie lyckades författarna kartlägga den

    nuvarande beslutsprocessen hos den specifika avdelning. Processen visade sig vara rätt så informell och

    bestod inte av nårgra formella kriterier. Under en workshop, identifierades och definierades en mängd

    formella beslutskriterier, tillsammans med arbetsgruppen. Slutligen har den nya PPM processen

    definierats och visualiserats av författarna.

    Ett antal övergripande och viktiga reflektioner togs av författarna efter att ha utfört detta examensarbete.

    Den viktigaste reflektionen är det faktumet att varje PPM process är och bör vara företagsspecifik. Då

    en PPM process utvecklas bör de faktiskt beslutsfattarna vara involverade i denna utveckling. Detta för

    att öka förståelsen för den slutgiltiva processen.

  • 32.
    Abele, Andreas
    et al.
    Continental Gmbd, Germany.
    Johansson, Rolf
    SP.
    Lönn, Henrik
    Volvo Technology AB.
    Papadopoulos, Yiannis
    Hull University, UK.
    Reiser, Mark-Oliver
    Technical Univ of Berlin.
    Servat, David
    CEA, France.
    Törngren, Martin
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Inbyggda styrsystem.
    Weber, Matthias
    Technische Universit¨at Berlin, DE.
    The CVM framework: A prototype tool for compositional variability management2010Ingår i: Proceeding of: Fourth International Workshop on Variability Modelling of Software-Intensive Systems, 2010, s. 101-105Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article announces the first public release ofan experimental research tool for variability management,called “CVM framework” and provides an overview of thetool’s capabilities and architecture.

  • 33.
    Abelin, Sarah
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Investigation of integrated waterlevel sensor solution forsubmersible pumps: A study of how sensors can be combined towithstand build-up materials and improvereliability in harsh environment2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Att övervaka vattennivån i extrema miljöer för att hantera start- och stoppfunktion av dräneringspumpar har varit ett stort problem. Flera påverkande faktorer från pumpomgivningen influerar och stör sensormätningarna. Nuvarande lösningar med mekaniskt rörliga nivåvippor som är monterade utanför pumparna slits ut, trasslar in sig och står för mer än hälften av alla jourutryckningar till pumpstationerna. Eftersom pumpar ofta flyttas runt, behövs en ny sensorlösning som kan integreras i pumpen och som kontinuerligt kan övervaka vattennivån för att optimera pumpdriften och minska  slitage, kostnad och energiförbrukning.

    Den här masteruppsatsen presenterar en undersökning av hur olika givartekniker kan kombineras för att förbättra tillförlitligheten för övervakning av vattennivån och hantera start- och stoppfunktionen av dräneringspumpar i extrema miljöer. Fokus har legat på att identifiera lämpliga givartekniker för att mäta vattennivå och undersöka hur givare påverkas av beläggningar som byggs upp på pumpytan och täcker givarna. En support vector machine algoritm har implementerats för att kombinera givardata i syfte att öka tillförlitligheten hos givarlösningen i kontaminerat skick.

    Resultaten visar att en kombination av en tryckgivare och en kapacitiv givare är den mest lämpliga kombinationen för att motstå beläggningsmaterial. För driftsförhållanden när givarna är täckta med mjuka beläggningar kunde givarna mäta vattennivån genom beläggningarna. Ingen lösning identifierades som på ett tillfredsställande sätt kunde mäta vattennivå genom stelnade, solida beläggningsmaterial.

  • 34.
    Abraham, Adonai
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Göranson, Max
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Att tänka utanför arket: En kartläggning över samarbeten som lett till produktinnovationer inom svensk pappers- och massaindustri 2014Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    För drygt ett decennium sedan började marknaden för tryckpapper att vika. Den svenska pappers- och massaindustrin fick en ny annorlunda konkurrent genom introduktionen av till exempel smarta telefoner och surfplattor. Utvecklingen har medfört att svenska pappers- och massaföretag i högre utsträckning har börjat titta på mer radikala innovationer i sin produktutveckling där nya användningsområden för träråvaran utforskas, en inriktning som kräver kompetenser utöver de som bolagen besitter internt.

    Studiens syfte är att undersöka olika samarbetsformer inom svensk pappers- och massaindustri för att kartlägga vilka faktorer som varit, och är, framgångsrika för produktinnovationer. Ambitionen är också att undersöka om det skett en förändring i samarbetenas karaktär under de senaste 25 åren. De företag som deltagit i studien är

    SCA, Södra Cell, Holmen/MoDo, Stora Enso, BillerudKorsnäs och Rottneros samt ett antal samarbetspartner till dem.

    Resultaten visar att såväl samarbetsformer som vilka aktörer svensk skogsindustri samarbetar med har förändrats i stor utsträckning. Branschen har börjat söka alltmer samarbete med andra branscher samtidigt som samarbeten med konkurrenter har minskat kraftigt. Under samma period har det blivit viktigare att reglera samarbeten i avtal och bland annat hur de immateriella värdena, som patent, fördelas mellan deltagarna i ett samarbete.

    En annan slutsats är att det finns en koppling mellan samarbeten och genereringen av en organisations produktinnovationer. Företag är beroende av extern kompetens för att lyckas med radikala innovationer och en bred kunskapsbas är att föredra för att bäst producera produktinnovationer. Extern kompetens kan till exempel hjälpa företagen att öka förståelsen för andra/nya marknader och kan således vara ett sätta att hitta helt nya användningsområden för den värdefulla råvara skogen erbjuder.

    Nyckelord: radikal innovation, samarbete, svensk pappers- och massaindustri

  • 35.
    Abrahamsson, Johan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Danmo, Johan
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    The Stabilizing Spoon: Self-stabilizing utensil to help people withimpaired motor skills2017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Teknologiska hjälpmedel för människor som har en funtionsnedsättning

    har förbättrats under de senaste decennierna.

    Med dagens teknologi kan personer drabbade av

    Parkinson’s disease, med en apparat på deras handled, vara

    kapabla till att måla teckningar. Mänskliga lemmar som

    förlorats vid olyckor kan ersättas med bioniska lemmar, och

    med hjälp av smartphones kan blinda personer bli informerade

    om vilken typ av objekt som finns framför dem. Detta

    är bara några få exempel på när teknologi har underlättat

    vardagen för människor med funktionsnedsättning.

    Syftet med detta projekt är att undersöka hur en Arduino

    mikrokontroller kan implementeras vid måltider för att assistera

    människor som har en motorisk funktionsnedsättning.

    En prototyp av en stabiliserande sked konstruerades för att

    fungera under verkliga förhållanden och dess intention var

    att verka som ett komplement för människor som behöver

    assistans vid måltider.

    För att göra detta möjligt användes en sensor med gyroskop

    och accelerometer för att identifiera vilken riktning

    enhetens handtag var lutad åt samt hur snabbt handtaget

    förflyttades. Två servomotorer placerades ortogonalt mot

    varandra f¨or att skapa ett system med tv°a frihetsgrader.

    Med denna upps¨attning var det t¨ankt att skeden skulle

    h°alla dess skedsk°al i en horisontell position. Experimentella

    resultat av skeden visade lovande prestanda med n°agra

    begränsningar.

  • 36.
    Abukar, Hared
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Al Saati, Firas
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Weda pool cleaner Concept P1002016Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syftet med detta examensarbete var att ta fram en ny drivlina för Wedas nuvarande robot poolrengörare W50. I nuläget är pumpen integrerad i drivlinan som består endast av en motor som driver både hjul och pump. Detta orsakar ett kritiskt problem som påverkar städning vid lutningar i poolen då roboten glider ner för lutningen. För att få en bättre insikt i hur produkten fungerar gjordes studiebesök till Weda. Projektgruppendokumenterade och observerade hur den nuvarande modellen och dess komponenter är monterade. Intervjuer utfördes med vaktmästare och fastighetsskötare inom olika kommunala bad och hotellpooler för att få en djupare förståelse för hur dessa robot poolrengörare används och vilka förbättringsområden som finns. Faktainsamlingen användes som grund för att ta fram förslag för nya och alternativa komponenter till det nya konceptet. De olika lösningarna blev sedan utvärderade med hjälp en beslutsmatris för att kunna bestämma vilka komponenter som skulle ingå i det slutgiltiga konceptet. Arbetet har utförts i nära samarbete med Adigo Drives, som bistått med sin expertis gällande motorer och drivlinor. Resultatet utmynnade i ett slutgiltigt koncept med en ny drivlina och en lägre vikt än den befintliga roboten.

  • 37.
    ACHKOUDIR, HOUSSAM
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Hanna, Naowar
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Studie av verkningsgrad potentialen för ett vatten baserat Waste Heat Recovery system med kolvexpander2011Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    SammanfattningEn ånganna monterades i EGR (Exhaust Gas Recirculation) slingan på en 12,7 liters Scania Euro V motor (DC1306). En modell som beskriver Rankine cykel togs fram med vatten som köldmedium i simuleringsverktyget GT-Power. Ångpannan i GT-power modellen kalibrerades m.h.a experimentell data.Simuleringarna visade att det optimala ångtrycket, det trycket där högst effekt kan erhållas från expandern, är beroende av EGR temperaturen. Det innebär att ju högre EGR inloppstemperatur desto högre optimalt ångtryck. EGR temperaturen i punkt 2 i ESC cykeln är 514˚ C för denna motor, vilket resulterar i ett optimalt tryck på 120 bar enligt simuleringen. Vidare analyserades den optimala överhettningsgraden, vilket innebär antalet grader som ångan uppvärms vid konstant tryck efter att allt vatten har förångats. Simuleringarna visar att högst effekt i expandern erhålls då ångan överhettas 10 grader, alltså den lägsta överhettningsandelen. Detta beror på att ångeffekten från ångpannan är högst vid lägst andel överhettningsgrad, vilket beror på ett högre vatten flöde.Simuleringen visar att EGR temperaturen är viktigare än EGR flödet. Ett sätt att öka EGR temperaturen är genom att tillsatselda. Detta innebär att spruta in bränsle i avgasröret. Beräkningar visar dock att det är lönsammare att spruta in bränslet direkt i förbränningsrummet. Att öka EGR temperaturen med 150˚C skulle resultera i ca 2,5 kW ökning i erhållen effekt från exandern. Att spruta in samma dieselflöde i förbränningsrummet skulle medföra en effektökning med ca 5,2 kW från motorn.Vid det optimala ångtrycket samt 10 graders överhettad ånga minskar bränsleförbrukningen för punkt 2 i ESC cykeln med 1,4 %. WHR (Waste Heat Recovery) systemet verkningsgrad ligger på 18,4 %. Vid montering av ytterliggare en ångpanna efter turbinen för att på så vis utnyttja energin i avgasflödet, istället för bara i EGR gaserna, skulle bränsleförbrukningen minska med 3,41 %.

  • 38.
    Adamsson, Niklas
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Interdisciplinary integration in complex product development: managerial implications of embedding software in manufactured goods2007Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Incorporating electronics and software systems into manufactured goods is becoming very common in manufacturing companies. New technical functions, increased flexibility, and compensation for mechanical design weaknesses are some key drivers of this technological change in our everyday products. The automotive industry exemplifies this trend, since approximately 80–90% of new functions in cars are based on electronics and software, and it is expected that at least a third of the total cost of a car will eventually be accounted for by electronics and software. However, one of the main downsides of this technological trend is the increasing number of quality issues related to these new technologies, something usually claimed to be a result of the increased product development complexity.

    Previous research into product development management has mainly concentrated on either physical products or software systems, but not concurrently on both. Additionally, much of the research has concentrated on issues of integrating marketing, R&D, and manufacturing in these companies, and has treated the engineering disciplines in R&D as a homogenous group. Motivated by this change in technology content and the lack of research into complex product development and especially into integration between engineering disciplines, the present work investigates how to increase operational performance in multidisciplinary engineering organizations. This work has especially focused on interdisciplinary integration and the feasibility of various so-called integration mechanisms, such as building common physical facilities, job rotation programs, the implementation and use of information and communications technology, and computer-aided engineering tools.

    Both qualitative and quantitative research has been performed, involving 11 different companies and over 300 respondents. Supported by the present findings, it is demonstrated that interdisciplinary integration is a crucial factor to consider, and it is concluded that certain integration mechanisms stand out as more important than others. Organizational structure, work procedures and methods, training, social systems, and computer-aided engineering were the five types of mechanisms that displayed the greatest potential for improvement.

    It is further concluded that the ability to successfully match the body of practices to current products is essential, since there is a high risk of current practices becoming out-dated with respect to the technology content. Furthermore, inadequate identification of or managerial ability to establish the currently most important interfaces complicate the choice of trade-offs between various technologies that are found to be essential to cope with the inherent dynamic complexity. The organizational powerbase is often re-positioned in the studied organizations, and the loss of decisive power can result in a demoralizing ignorance of newly established disciplines and their design practices. Additionally, rigid structures and counterproductive traditions can reduce the potential gains accruing from new boundary-spanning innovations, so organizational responsibilities and mandates must be declared unambiguously, in many cases differently from how they have been in the past.

    Based on these conclusions, it is suggested that managers in organizations like those studied must be able to do the following: cultivate software knowledge in all parts and levels of the product development organization; reassess their recruitment strategies; organize for interdisciplinary collaboration; articulate and communicate the technology fusion strategy to all disciplines; and realize and disseminate the fact that product launches do not only concern manufacturability.

  • 39.
    Adamsson, Niklas
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Management of mechatronics engineering: reflections and propositions2005Ingår i: Proceedings of 12th International Product Development ManagementConference, vol. 1, 2005, Vol. 1(3), s. 35-48Konferensbidrag (Refereegranskat)
  • 40.
    Adamsson, Niklas
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Mechatronics engineering: New requirements on cross-functional integration2005Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Several industrial sectors experience an increased reliance on mechatronic systems as electronics and software are being embedded into the traditional mechanical systems of these industries. Important challenges within mechatronics engineering comes from management of multi-disciplinary development project teams and the highly complex scope of problems, which in turn require extensive coordination and integration, both in terms of technical and organisational matters.

    The concept of cross-functional integration in product development research has in previous research mainly addressed integration of the functions marketing, R&D, and manufacturing, and whereas the present thesis is delimited to include only the R&D organization and the functions and engineering disciplines within such an organization.

    The purpose with thesis has been to investigate mechatronics engineering in order to understand and explain how co-operation, integration, and knowledge sharing between engineering disciplines can be supported.

    This research has been realized by empirical studies in mechatronic development settings in engineering companies, but also by taking part in industrial and academic research projects that develop and study computer-aided mechatronics engineering.

    Findings presented in this thesis show that mechatronics is a matter of integration at three organizational levels where the most substantial needs are found to be at the team-level and the individual level. Furthermore, it is identified that to be able to succeed in mechatronics engineering, managers and engineers must look beyond disciplinary needs. Subsequently, both teamwork and competence management become key issues for management of mechatronics engineering. Finally, computer-supported and model-based development of mechatronics show great potential for successful integration of engineering disciplines, even though such technological aids are still rather immature and needs further research and development. A tentative analysis model of organizational integration for mechatronics engineering is also presented and discussed in this thesis.

    Based on the presented findings, it is concluded that companies incorporating electronics and software in their mechanical products must effectively manage software and electronics development of these embedded systems. Despite the focus on cross-functional integration in engineering companies, this thesis shows examples of inadequate integration of software and electronics engineering with mechanical integration in organisations dominated by the latter.

    Future research studies are needed to investigate the relation between factors influencing the need for organizational integration and potential integration mechanisms. To further understand mechatronics engineering it is important to look deeper into research issues such as changed conditions for the engineering profession implied by multidisciplinary settings, social systems supporting integration of disciplines, changed work conditions due to implementation of technological aids for model-based system development, relationship between product and organizational complexity, organizational designs supporting integration of engineering disciplines, and cross-disciplinary training of highly specialized engineers.

  • 41.
    Adamsson, Niklas
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Integrerad produktutveckling.
    Grimheden, Martin
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    The Product Developer: Education and Professional Role2007Ingår i: Proceedings of ICED 2007, the 16th International Conference on Engineering Design, 2007Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this paper is to present results from a study examining the relation between the educational background and professional roles with engineers engaged in product development. Derived from previous studies, the product development engineer ought to be a multifaceted engineer, knowledgeable and skilled in several fields. This engineer should work interdisciplinary, integrative and with the aim to be creative and innovative. By using a substantial data set consisting of 300 engineers in Swedish product development organizations, we derive some important research propositions. The data shows that there are correlations between organizational responsibilities and educational program, in particular regarding focus on design, system integration, project management and technical coordination. If we want to understand how the engineering education affects the professional role of an engineer; we believe that it is critical to further investigate the developed propositions. One example is mechanical engineers; the data shows that the studied mechanical engineers rarely work with design. Our proposition is therefore to investigate the identity and legitimacy of these programs to further clarify the professional role.

  • 42.
    Adamsson, Niklas
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Malvius, Diana
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Formal and informal roles in complex product development2005Ingår i: 2005 IEEE International Engineering Management Conference, Vols 1 and 2, 2005, s. 559-563Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper illustrates the importance of well-articulated and demarcated roles in complex product development settings. In order to support interdisciplinary knowledge and information sharing formally assigned roles in an organization can be an effective facilitator. It is argued that without comprehensive technical knowledge it is difficult for individuals to identify the relevance and distinctiveness of technical and administrative information.

  • 43.
    Adamsson, Niklas
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Zika-Viktorsson, Annika
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Challenges and outlooks for software and electrical engineering in traditional mechanical engineering companies: an investigation into workforce implications2006Artikel i tidskrift (Övrigt vetenskapligt)
  • 44.
    Adamsson, Niklas
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Zika-Viktorsson, Annika
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Multidisciplinary product development: - a case study of mechatronics enineeringArtikel i tidskrift (Övrigt vetenskapligt)
  • 45.
    Adamsson, Niklas
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Zika-Viktorsson, Annika
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    The relative effectiveness of different mechanisms for integrating engineering disciplines in complex product development2007Artikel i tidskrift (Övrigt vetenskapligt)
  • 46.
    Adamsson, Niklas
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Zika-Viktorsson, Annika
    Understanding the importance of interdisciplinary integration in complex product development2007Rapport (Övrigt vetenskapligt)
  • 47. Adlercreutz, Ludvig
    et al.
    Cronhjort, Andreas
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Andersen, J.
    Ogink, R.
    Optimizing the Natural Gas Engine for CO2 reduction2016Ingår i: SAE Technical Papers, SAE International , 2016, Vol. 2016-April, nr AprilKonferensbidrag (Refereegranskat)
    Abstract [en]

    With alternative fuels having moved more into market in light of their reduction of emissions of CO2 and other air pollutants, the spark ignited internal combustion engine design has only been affected to small extent. The development of combustion engines running on natural gas or Biogas have been focused to maintain driveability on gasoline, creating a multi fuel platform which does not fully utilise the alternative fuels' potential. However, optimising these concepts on a fundamental level for gas operation shows a great potential to increase the level of utilisation and effectiveness of the engine and thereby meeting the emissions legislation. The project described in this paper has focused on optimising a combustion concept for CNG combustion on a single cylinder research engine. The ICE's efficiency at full load and the fuels characteristics, including its knock resistance, is of primary interest - together with part load performance and overall fuel consumption. In the process of increasing the efficiency of the engine the following areas have been of primary interest, increased compression ratio, thermal load at high cylinder pressure and the use of EGR to further increase efficiency. The overall goal in the project was to reduce the CO2-emissions while maintaining the performance and characteristics of the engine. The ambition is to reduce specific tail-pipe CO2-emissions in g/kWh by 50% compared to a modern gasoline engine. The goal was close to being reached at 45% reduction at full load and 25-34% on part load. This was done by theoretically downsizing the engine and increasing the specific performance of the engine.

  • 48. Adlercreutz, Ludvig
    et al.
    Cronhjort, Andreas
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Stenlåås, Ola
    Particle Emission Measurements in a SI CNG EngineUsing Oils with Controlled Ash Content2019Ingår i: SAE Technical Papers, 2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Clean combustion is one of the inherent benefits of using a high methane content fuel, natural gas or biogas. A single carbon atom in the fuel molecule results, to a large extent, in particle-free combustion. This is due to the high energy required for binding multiple carbon atoms together during the combustion process, required to form soot particles. When scaling up this process and applying it in the internal combustion engine, the resulting emissions from the engine have not been observed to be as particle free as the theory on methane combustion indicates. These particles stem from the combustion of engine oil and its ash content. One common practice has been to lower the ash content to regulate the particulate emissions, as was done for diesel engines. For a gas engine, this approach has been difficult to apply, as the piston and valvetrain lubrication becomes insufficient. However, the low particle emissions from the combustion of CNG does allow for an investigation of particle contribution from engine oil ash content with only a minor particle contribution from the fuel itself. The hypothesis for this study is that there is a relationship between the engine oil ash content and the particulate emissions from a CNG engine. The investigation was conducted for several operating points with varying engine speeds and load on a single cylinder engine. The single cylinder approach was chosen to reduce sources of engine oil intrusion in the combustion chamber. The obtained results were not in line with the hypothesis, the particle emissions from the lower ash content oil did not decrease in number but the size of the particles did. The results also showed a spiking behavior in the particulate emissions, originating from the lubrication oil consumption past the piston rings. Mass flow through the engine proved to affect the particle size distribution as well as the total number of particles for all levels of oil ash content.

  • 49. Adlercreutz, Ludvig
    et al.
    Cronhjort, Andreas
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Stenlåås, Ola
    Variation in Squish Length and Swirl to Reach Higher Levels of EGRin a CNG Engine2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Gaseous methane fuel for internal combustion engineshave proved to be a competitive source of propulsionenergy for heavy duty truck engines. Using biogascan even reduce the carbon footprint of the truck to near-zerolevels, creating fully environmentally friendly transport. Gasengines have already been on the market and proved to be apopular alternative for buses and waste transport. However,for long haulage these gas engines have not been on par withthe equivalent diesel engines. To improve the power and efficiencyof EURO VI gas engines running stoichiometrically, adirect way forward is adding more boost pressure and sparkadvance in combination with more EGR to mitigate knock.Using in-cylinder turbulence to achieve higher mixing rate,the fuel can still be combusted efficiently despite the increasedfraction of inert gases. In this paper, previous findings onin-cylinder air flows for diesel engine simulations are investigatedfor the applicability on to stoichiometric gas combustion.Two key parameters were identified, swirl and squish.By varying the levels of swirl with different squish lengths inthe piston design, the in-cylinder flow motion is altered toinvestigate its effect on stoichiometric gas combustion. Thetesting was performed on a single cylinder research engineoperated in the equivalent multi cylinder engine operatingpoints. The results show that previous modelling findings areverified on the pre-mixed gas combustion studied. By choosingswirl and squish for the design of the gas engine, it is possibleto increase the combustion speed and thus the fraction of EGRin the combustion charge, without the latter having a negativeimpact on the combustion.

  • 50.
    Adolfsson, Johan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Thalén, David
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Utveckling av barnvagn2008Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    After contacting the company Elite Group Sverige AB, who sells strollers under the brand Crescent Baby, it was determined that the project group were to develop a three wheeled stroller which was going to be Crescents first own developed stroller. Only the frame of the stroller was considered within the demarcation of this project however care was taken to the placement of the carry-cot and the wheels etc. Crescent Baby wished for the frame would be smaller than the competitor Urban Jungle, that the frame would have at least three unique selling points and that the number of unique parts was to be minimized. The work began with information seeking regarding strollers, competitors, independent tests, European standards and consumer interviews. After that a number of concepts were developed and past to Crescent. From these concepts the one that was to be called Stealth was chosen. Stealth was further developed and CAD-files, pictures and blueprints were made for the frame Stealth has a classic and well tested suspension but now applicable with a three wheeled stroller. The frame is made up by aluminum profiles and injection moulded plastic details which link the profiles together. The frame is dimensioned to be smaller than Urban Jungle and its form is inspired by bicycles. Stealth has as of today a number of unique selling points and the frame is smaller than the maximum measurements specified. The number of unique parts has also been kept at a minimum. To continue the development the specifications for manufacturing have to be more defined, and the parts not treated in this thesis has to be developed.

1234567 1 - 50 av 3123
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf