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Sample records for repair automotive mechanic

  1. Case study. Health hazards of automotive repair mechanics: thermal and lighting comfort, particulate matter and noise.

    Science.gov (United States)

    Loupa, G

    2013-01-01

    An indoor environmental quality survey was conducted in a small private automotive repair shop during May 2009 (hot season) and February 2010 (cold season). It was established that the detached building, which is naturally ventilated and lit, had all the advantages of the temperate local climate. It provided a satisfactory microclimatic working environment, concerning the thermal and the lighting comfort, without excessive energy consumption for air-conditioning or lighting. Indoor number concentrations of particulate matter (PM) were monitored during both seasons. Their size distributions were strongly affected by the indoor activities and the air exchange rate of the building. During working hours, the average indoor/outdoor (I/O) number concentration ratio was 31 for PM0.3-1 in the hot season and 69 for the cold season. However I/O PM1-10 number concentration ratios were similar, 33 and 32 respectively, between the two seasons. The estimated indoor mass concentration of PM10 for the two seasons was on average 0.68 mg m(-3) and 1.19 mg m(-3), i.e., 22 and 36 times higher than outdoors, during the hot and the cold seasons, respectively. This is indicative that indoor air pollution may adversely affect mechanics' health. Noise levels were highly variable and the average LEX, 8 h of 69.3 dB(A) was below the European Union exposure limit value 87db (A). Noise originated from the use of manual hammers, the revving up of engines, and the closing of car doors or hoods. Octave band analysis indicated that the prevailing noise frequencies were in the area of the maximum ear sensitivity.

  2. Automotive Chassis; Automotive Mechanics-Basic: 9043.02.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    This automotive chassis course is designed to familiarize the beginning student of the history and development of the automobile with basic concepts common to the automobile industry, and general information that is required for successful advancement in the automotive mechanics field. It is one quinmester in a series of quinmester outlines…

  3. State Articulated Instructional Objectives Guide for Occupational Education Programs. State Pilot Model for Automotive Mechanics (DCC V-003) and Automotive Mechanics (High School).

    Science.gov (United States)

    North Carolina State Dept. of Community Colleges, Raleigh.

    This articulation instructional objective guide for automotive mechanics contains summary information on fifteen blocks (courses) of instruction. They are introduction to automotive technology; lubrication and vehicle operating maintenance; cooling system maintenance and repair; automobile heater maintenance and repair; braking system maintenance…

  4. Social media for knowledge sharing in automotive repair

    CERN Document Server

    Finkbeiner, Patric

    2017-01-01

    This book explores, describes and explains the predictors essential for the acceptance of social media as a digital platform to share professional knowledge in the field of automotive repair in Germany. It reports a rigorous literature review covering key elements of social media, knowledge management and technology acceptance studies. The book assumes a pragmatist approach and applies mixed methods in an exploratory sequential design, combining qualitative and quantitative methods to ensure robust collection and analysis of the collected data. Based on a survey on German automotive repair shops, the author provides a framework, for various stakeholders, to comprehend the motivations for knowledge sharing for automotive repair professionals in Germany. This book not only adds to the existing academic body of knowledge but also provides implications for industry and legislation on a European scale. .

  5. Careers Canada. Volume 3, Mechanical Repair Occupations.

    Science.gov (United States)

    Department of Manpower and Immigration, Ottawa (Ontario).

    This pamphlet, published by the Canadian Department of Manpower and Immigration, is the third of a Careers-Canada series and describes careers in mechanical repair occupations. The pamphlet is divided into eight major sections: (1) history and importance; (2) fields of work; (3) nature of work (this section is subdivided into automotive repair…

  6. Automotive History and Development of the Automobile; Automotive Mechanics I: 9043.01.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    The automotive history and development of the automobile course is designed to familiarize the beginning student with basic concepts common to the automobile history and general information that is required for successful advancement in the automotive mechanics field. A course outline is provided and seven pages of post-tests are included in the…

  7. Analysis of Workplace Accidents in Automotive Repair Workshops in Spain.

    Science.gov (United States)

    López-Arquillos, Antonio; Rubio-Romero, Juan Carlos

    2016-09-01

    To analyze the effects of the factors associated with different types of injury (superficial wounds, dislocations and sprains, bone fractures, concussion and internal injuries, burns scalding and freezing) caused by occupational accidents in automotive repair workshops. Study of a sample consisting of 89,954 industry accidents reported from 2003 to 2008. Odds ratios were calculated with a 95% confidence interval. Belonging to a small company is a risk factor for suffering three of the five types of injury studied. Women are less likely to suffer burns and superficial wounds, and more likely to suffer dislocations or sprains. Foreign workers are more likely to suffer concussion and internal injuries. Health and safety strategies and accident prevention measures should be individualized and adapted to the type of worker most likely to be injured in each type of accident. Occupational health and safety training courses designed according to worker profile, and improving the participation of the workers in small firms creating regional or roving safety representatives would improve working conditions.

  8. Automotive radar - investigation of mutual interference mechanisms

    Science.gov (United States)

    Goppelt, M.; Blöcher, H.-L.; Menzel, W.

    2010-09-01

    In the past mutual interference between automotive radar sensors has not been regarded as a major problem. With an increasing number of such systems, however, this topic is receiving more and more attention. The investigation of mutual interference and countermeasures is therefore one topic of the joint project "Radar on Chip for Cars" (RoCC) funded by the German Federal Ministry of Education and Research (BMBF). RoCC's goal is to pave the way for the development of high-performance, low-cost 79 GHz radar sensors based on Silicon-Germanium (SiGe) Monolithic Microwave Integrated Circuits (MMICs). This paper will present some generic interference scenarios and report on the current status of the analysis of interference mechanisms.

  9. Pneumatic, PLC Controlled, Automotive Gear Shifting Mechanism

    Directory of Open Access Journals (Sweden)

    Muntaser Momani

    2010-05-01

    Full Text Available In this study, a gear shifting mechanism was designed and applied to make the shifting process faster and less destructible for the driver. The new device must be reliable, has a small dimensions, low construction and maintenance cost. This paper aims to improve gear shifting process using devices as: a manual four speed gear box, four pneumatic double acting cylinders, four pneumatic two position five ways directional control valves, Programmable Logic Controller (PLC LOGO unit, an electrical motor, an electrical clutch, a belt, two pulleys, limit switches, push buttons, bulbs, a table (holder and power supply. According to suggested gear_ shifting method the driver can select the transmission gear ratio without moving his hands from the steering wheel by putting the gear shifting push buttons on the steering wheel. Using this method leaves to the driver the excitement of choosing the shifting moment.

  10. Fatigue and Mechanical Damage Propagation in Automotive PEM Fuel Cells

    Science.gov (United States)

    Banan, Roshanak

    Polymer electrolyte membrane (PEM) fuel cells are generally exposed to high magnitude road-induced vibrations and impact loads, frequent humidity-temperature loading cycles, and freeze/thaw stresses when employed in automotive applications. The resultant mechanical stresses can play a significant role in the evolution of mechanical defects in the membrane electrode assembly (MEA). The focus of this research is to investigate fatigue challenges due to humidity-temperature (hygrothermal) cycles and vibrations and their effects on damage evolution in PEM fuel cells. To achieve this goal, this thesis is divided into three parts that provide insight into damage propagation in the MEA under i) hygrothermal cycles, ii) external applied vibrations, and iii) a combination of both to simulate realistic automotive conditions. A finite element damage model based on cohesive zone theory was developed to simulate the propagation of micro-scale defects (cracks and delaminations) in the MEA under fuel cell operating conditions. It was found that the micro-defects can propagate to critical states under start-up and shut-down cycles, prior to reaching the desired lifespan of the fuel cell. The simultaneous presence of hygrothermal cycles and vibrations severely intensified damage propagation and resulted in considerably large defects within 75% of the fuel cell life expectancy. However, the order of generated damage was found to be larger under hygrothermal cycles than vibrations. Under hygrothermal cycles, membrane crack propagation was more severe compared to delamination propagation. Conversely, the degrading influence of vibrations was more significant on delaminations. The presence of an anode/cathode channel offset under the combined loadings lead to a 2.5-fold increase in the delamination length compared to the aligned-channel case. The developed model can be used to investigate the damage behaviour of current materials employed in fuel cells as well as to evaluate the

  11. Maintenance And Repair of Automotive Engine%汽车发动机的维护及保养

    Institute of Scientific and Technical Information of China (English)

    白有俊

    2014-01-01

    Correct and reasonable maintenance and repair of automotive engine is an important link to improve technical performance of the automobile, extend its life, reduce economic losses and ensure traffic safety. The article discusses in details how to have the reasonable and effective maintenance and repair for the automotive engine from the related engine knowledge.%正确合理地对汽车发动机进行维护和保养是提高汽车技术性能,延长其使用寿命,减少经济损失,保证行车安全的重要环节。文章从论述发动机相关知识等入手,对如何进行合理有效的汽车发动机维护和保养两个方面进行详细阐述。

  12. Automotive Air Conditioning and Heating; Automotive Mechanics (Advanced): 9047.04.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    This document presents an outline for a 135-hour course designed to provide the student with all the foundations necessary to become employable in the automotive air conditioning and heating trade. The course of study includes an orientation to the world of work, the elementary physics of air conditioning and heating, and laboratory experiments…

  13. Grain Refiner Effect on the Microstructure and Mechanical Properties of the A356 Automotive Wheels

    Science.gov (United States)

    Aguirre-De la Torre, E.; Afeltra, U.; Gómez-Esparza, C. D.; Camarillo-Cisneros, J.; Pérez-Bustamante, R.; Martínez-Sánchez, R.

    2013-12-01

    A356 aluminum alloy automotive wheels, 17 inch in diameter, were produced by low-pressure die casting. Contents of Al-5Ti-B (ATB) master alloy were added from 0 to 0.79 wt.%. Microstructural and mechanical properties were evaluated under industrial casting process conditions. The obtained results from mechanical testing provide evidence that additions of 0.13 and 0.27 wt.% of ATB have an improvement on the mechanical performance of the automotive wheels. This can be compared with the use of a grain refiner's higher concentrations, leading to a significant reduction in the cost-benefit ratio for the manufacturing of A356 automotive wheels.

  14. A Secure Mechanism to Supervise Automotive Sensor Network by Client on Smart Phone

    Directory of Open Access Journals (Sweden)

    T R Yashavanth

    2013-03-01

    Full Text Available This paper presents a proposal on design of a secure client on smart phone to monitor automotive sensor network. Recently, more and more vehicles, such as BMW X5, are connected from outside via smart phone [3]. From smart phone, users can use the internet resources in automotive. Users can monitor the automotives by using their smart phones. When the automotive is moving or stolen by robber, alert information will be reported to users and users can even brake their automotive via smart phone in emergency status by sending control command to the vehicle information gateway. So client software in smart phone is required to monitor the sensor network in automotives. In order to prevent malicious attack on the client software by malicious attackers which are usually the robbers, there should be a mechanism provided to the clients which offers security by considering few criteria’s like power of computation, level of security and consumption of power. This proposed method uses IDEA for the encryption of all the messages since IDEA has high level of security and suitable to implement in software and also demands on computational power is less. Record management set is being suggested for the storage of critical data which is a Java MIDlet based mechanism. Between client software and its gateway a communication management on transaction is also proposed. The verification of the key updating process is verified with model checking in UPPAAL [7].

  15. Wear effects and mechanisms of soot-contaminated automotive lubricants

    OpenAIRE

    Green, D. A.; Lewis, R; Dwyer-Joyce, R.S.

    2006-01-01

    A study has been carried out to investigate the influence of soot-contaminated automotive lubricants in the wear process of a simulated engine valve train contact. Previous research on this topic has been mainly performed from a chemical point of view in fundamental studies, with insufficient relevance to real engine conditions, i.e. load and geometry. This study investigates the conditions under which wear occurs through specimen testing. The objective of the work was to understand the wear ...

  16. Automotive radar – investigation of mutual interference mechanisms

    OpenAIRE

    2010-01-01

    In the past mutual interference between automotive radar sensors has not been regarded as a major problem. With an increasing number of such systems, however, this topic is receiving more and more attention. The investigation of mutual interference and countermeasures is therefore one topic of the joint project "Radar on Chip for Cars" (RoCC) funded by the German Federal Ministry of Education and Research (BMBF). RoCC's goal is to pave the way for the development of high-per...

  17. Study on Variable Capacity Control Mechanism of Scroll Compressor for Automotive Air Conditioner

    Science.gov (United States)

    Hirano, Takahisa; Shigeoka, Tetsuo

    As for the automotive air conditioner, (1) to keep the automotive cabin temperature in a comfortable region, (2) to improve driving feeling, (3) to drive the air conditioning system economically through all seasons, are universally required. Recently, from these points, compressors with variable capacity control mechanism for automotive air conditioners have been remarkably requested. We have developed a scroll comoressor with variable capacity control mechanism. The capacity control mechanism, which changes the channel area of the bypass hole continuously, according to the suction gas pressure and the discharge gas pressure, has been developed. In this report, we describe the mechanism of variable capacity control and the performance simulation program that has been developed for the scroll compressor. Further, we describe the measuring results of cylinder pressure behavior, the results of energy loss analysis and the effect of comfort, drivability, power saving in the refrigerating cycle using the developed capacity control compressor.

  18. Engine Tune-Up Service. Unit 5: Fuel and Carburetion Systems. Student Guide. Automotive Mechanics Curriculum.

    Science.gov (United States)

    Goodson, Ludy

    This student guide is for Unit 5, Fuel and Carburetion Systems, in the Engine Tune-Up Service portion of the Automotive Mechanics Curriculum. It deals with inspecting and servicing the fuel and carburetion systems. A companion review exercise book and posttests are available separately as CE 031 218-219. An introduction tells how this unit fits…

  19. WEAR FAILURE MECHANISM AND MULTI-IMPACT PROPERTY OF AUTOMOTIVE ENGINE CHAIN

    Institute of Scientific and Technical Information of China (English)

    Meng Fanzhong; Wang Shukun; Lan Hong; Xu Rongjin; Xu Hanxue

    2005-01-01

    The multi-impact characteristics and failure mechanism of two kinds of automotive engine chain made in China are studied through engine assembly and road-drive tests. The worn surface morphologies of rubbing area between pin, bush and roller are also analyzed based on scanning electron microscope. The results show that the main wear mechanism of automotive engine chain is fatigue wear, and its failure mechanism is the forming, extending and flaking of cracks on top layer of pin and bush. In addition, the material, hot-treatment method and shaping technique for roller have a great influence upon the resistance to multi-impact. Ensuring sufficient strength and plasticity of roller, as well as adopting suitable shaping technique are the effective method to increase its resistance to multi-impact.

  20. On the Mechanical Friction Losses Occurring in Automotive Differential Gearboxes

    Directory of Open Access Journals (Sweden)

    Grégory Antoni

    2014-01-01

    Full Text Available In the automobile industry, the mechanical losses resulting from friction are largely responsible for various kinds of surface damage, such as the scuffing occurring in some mechanical assemblies. These scuffing processes seem to be due to a local loss of lubrication between certain mechanical elements of the same assembly, leading to a sharp increase in the friction, which can lead to a surface and volume damage in some of them, and even can cause, in the worst case, the whole destruction of the mechanical system if it has continued to operate. Predicting and checking the occurrence of this kind of undesirable phenomena, especially in some principal systems of the vehicle, represents nowadays, a crucial challenge in terms of automobile reliability and safety. This study focuses on the mechanical friction losses liable to occur in differential automobile gearboxes, which can lead in the long term to the scuffing of these mechanical systems. The friction losses involved were modeled, using a simple analytical approach, which is presented and discussed.

  1. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT II, MECHANICAL TRANSMISSIONS.

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF MECHANICAL TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) PURPOSE OF TRANSMISSIONS, (2) RATIO DIFFERENCE, (3) CONSTANT MESH TRANSMISSIONS, (4) FOUR-SPEED TRUCK TRANSMISSION POWER FLOW, AND (5) TRANSMISSION TROUBLESHOOTING.…

  2. REPAIR MECHANISM IN FOREIGN LANGUAGE CLASSROOM INTERACTION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents practical research on repair mechanismand its four repair trajectories in FL classroom interaction. Thisshows that it is effective and efficient in assisting FL learners todevelop their communicative competence and understand theprocess of language acquisition. Repair strategies that are ofgreat value to FL teachers in FL classroom teaching are also ex-pounded.

  3. DNA repair mechanisms in C. elegans

    NARCIS (Netherlands)

    Brouwer, K.|info:eu-repo/dai/nl/336462557

    2009-01-01

    DNA is the carrier of genetic information. DNA is constantly damaged by, for example, UV light and X-rays. Cells can utilize a large number of proteins that can repair the damages, thereby avoiding changes in the DNA sequence. Damages that are not repaired result in an increase in the number of muta

  4. Reliability of automotive and mechanical engineering. Determination of component and system reliability

    Energy Technology Data Exchange (ETDEWEB)

    Bertsche, Bernd [Stuttgart Univ. (Germany). Inst. fuer Maschinenelemente

    2008-07-01

    In the present contemporary climate of global competition in every branch of engineering and manufacture it has been shown from extensive customer surveys that above every other attribute, reliability stands as the most desired feature in a finished product. To survive this relentless fight for survival any organisation, which neglect the plea of attaining to excellence in reliability, will do so at a serious cost Reliability in Automotive and Mechanical Engineering draws together a wide spectrum of diverse and relevant applications and analyses on reliability engineering. This is distilled into this attractive and well documented volume and practising engineers are challenged with the formidable task of simultaneously improving reliability and reducing the costs and down-time due to maintenance. The volume brings together eleven chapters to highlight the importance of the interrelated reliability and maintenance disciplines. They represent the development trends and progress resulting in making this book essential basic material for all research academics, planners maintenance executives, who have the responsibility to implement the findings and maintenance audits into a cohesive reliability policy. Although, the book is centred on automotive engineering nevertheless, the examples and overall treatise can be applied to a wide range of professional practices. The book will be a valuable source of information for those concerned with improved manufacturing performance and the formidable task of optimising reliability. (orig.)

  5. Automotive electronics design fundamentals

    CERN Document Server

    Zaman, Najamuz

    2015-01-01

    This book explains the topology behind automotive electronics architectures and examines how they can be profoundly augmented with embedded controllers. These controllers serve as the core building blocks of today’s vehicle electronics. Rather than simply teaching electrical basics, this unique resource focuses on the fundamental concepts of vehicle electronics architecture, and details the wide variety of Electronic Control Modules (ECMs) that enable the increasingly sophisticated "bells & whistles" of modern designs.  A must-have for automotive design engineers, technicians working in automotive electronics repair centers and students taking automotive electronics courses, this guide bridges the gap between academic instruction and industry practice with clear, concise advice on how to design and optimize automotive electronics with embedded controllers.

  6. Nucleus geometry and mechanical properties of resistance spot welded coated–uncoated DP automotive steels

    Indian Academy of Sciences (India)

    Ibrahim Sevim; Fatih Hayat; Mustafa Kemal Kulekci

    2013-11-01

    In this study, mechanical properties of resistance spot welding of DP450 and DP600, galvanized and ungalvanized automotive sheets have been investigated. The specimens have been joined by resistance spot welding at different weld currents and times. Welded specimens have been examined for their mechanical, macrostructure and microstructure properties. Depending on the weld current and time, effects of zinc coating on tensile properties, microhardness values as well as microstructure nugget geometry and nucleus size ratio have been investigated. X-ray diffraction analysis has been used to investigate the phase that formed at the joint interface. Result of the experiment show that nugget diameter, indentation depth and tensile load-bearing capacity are affected by weld parameters. Coating prevents full joining at low parameters. Microhardness increased in heat-affected zone and weld metal.

  7. Acquired Color Vision Defects and Hexane Exposure: A Study of San Francisco Bay Area Automotive Mechanics.

    Science.gov (United States)

    Beckman, Stella; Eisen, Ellen A; Bates, Michael N; Liu, Sa; Haegerstrom-Portnoy, Gunilla; Hammond, S Katharine

    2016-06-01

    Occupational exposure to solvents, including n-hexane, has been associated with acquired color vision defects. Blue-yellow defects are most common and may be due to neurotoxicity or retinal damage. Acetone may potentiate the neurotoxicity of n-hexane. We present results on nonhexane solvent and hexane exposure and color vision from a cross-sectional study of 835 automotive repair workers in the San Francisco Bay Area, California (2007-2013). Cumulative exposure was estimated from self-reported work history, and color vision was assessed using the Lanthony desaturated D-15 panel test. Log-binomial regression was used to estimate prevalence ratios for color vision defects. Acquired color vision defects were present in 29% of participants, of which 70% were blue-yellow. Elevated prevalence ratios were found for nonhexane solvent exposure, with a maximum of 1.31 (95% confidence interval (CI): 0.86, 2.00) for blue-yellow. Among participants aged ≤50 years, the prevalence ratio for blue-yellow defects was 2.17 (95% CI: 1.03, 4.56) in the highest quartile of nonhexane solvent exposure and 1.62 (95% CI: 0.97, 2.72) in the highest category of exposure to hexane with acetone coexposure. Cumulative exposures to hexane and nonhexane solvents in the highest exposure categories were associated with elevated prevalence ratios for color vision defects in younger participants.

  8. Reliability in automotive and mechanical engineering determination of component and system reliability

    CERN Document Server

    Bertsche, Bernd

    2008-01-01

    In the present contemporary climate of global competition in every branch of engineering and manufacture it has been shown from extensive customer surveys that above every other attribute, reliability stands as the most desired feature in a finished product. To survive this relentless fight for survival any organisation, which neglect the plea of attaining to excellence in reliability, will do so at a serious cost Reliability in Automotive and Mechanical Engineering draws together a wide spectrum of diverse and relevant applications and analyses on reliability engineering. This is distilled into this attractive and well documented volume and practising engineers are challenged with the formidable task of simultaneously improving reliability and reducing the costs and down-time due to maintenance. The volume brings together eleven chapters to highlight the importance of the interrelated reliability and maintenance disciplines. They represent the development trends and progress resulting in making this book ess...

  9. The Development of Productivity Practical Management Model at Automotive Mechanical Technology Skill Program in Semarang Vocational Schools, Indonesia

    Science.gov (United States)

    Hadromi; Rachman, Maman; Soesanto; Kartana, Tri Jaka

    2015-01-01

    The purpose of this research is to develop automotive Mechanical Technology Skill Program (TMO) in Vocational School. The Research and Development (R&D) object was done in SMK 1, 4 and 7 Semarang, Indonesia. The result was achieved productivity Practical Management Final Model at TMO skill Program in Vocational school named momanticproter.…

  10. Wound repair and regeneration: Mechanisms, signaling, and translation

    Science.gov (United States)

    Eming, Sabine A.; Martin, Paul; Tomic-Canic, Marjana

    2015-01-01

    The cellular and molecular mechanisms underpinning tissue repair and its failure to heal are still poorly understood, and current therapies are limited. Poor wound healing after trauma, surgery, acute illness, or chronic disease conditions affects millions of people worldwide each year and is the consequence of poorly regulated elements of the healthy tissue repair response, including inflammation, angiogenesis, matrix deposition, and cell recruitment. Failure of one or several of these cellular processes is generally linked to an underlying clinical condition, such as vascular disease, diabetes, or aging, which are all frequently associated with healing pathologies. The search for clinical strategies that might improve the body’s natural repair mechanisms will need to be based on a thorough understanding of the basic biology of repair and regeneration. In this review, we highlight emerging concepts in tissue regeneration and repair, and provide some perspectives on how to translate current knowledge into viable clinical approaches for treating patients with wound-healing pathologies. PMID:25473038

  11. SOLUTION TREATMENT EFFECT ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF AUTOMOTIVE CAST ALLOY

    Directory of Open Access Journals (Sweden)

    Eva Tillová

    2012-02-01

    Full Text Available The contribution describes influence of the heat treatment (solution treatment at temperature 545°C and 565°C with different holding time 2, 4, 8, 16 and 32 hours; than water quenching at 40°C and natural aging at room temperature during 24 hours on mechanical properties (tensile strength and Brinell hardness and microstructure of the secondary AlSi12Cu1Fe automotive cast alloy. Mechanical properties were measured in line with EN ISO. A combination of different analytical techniques (light microscopy, scanning electron microscopy (SEM were therefore been used for study of microstructure. Solution treatment led to changes in microstructure includes the spheroidization and coarsening of eutectic silicon. The dissolution of precipitates and the precipitation of finer hardening phase further increase the hardness and tensile strength of the alloy. Optimal solution treatment (545°C/4 hours most improves mechanical properties and there mechanical properties are comparable with mechanical properties of primary AlSi12Cu1Fe alloy. Solution treatment at 565 °C caused testing samples distortion, local melting process and is not applicable for this secondary alloy with 12.5 % Si.

  12. DEVELOPMENT OF PERMANENT MECHANICAL REPAIR SLEEVE FOR PLASTIC PIPE

    Energy Technology Data Exchange (ETDEWEB)

    Hitesh Patadia

    2004-09-30

    The report presents a comprehensive summary of the project status related to the development of a permanent mechanical repair fitting intended to be installed on damaged PE mains under blowing gas conditions. Specifically, the product definition has been developed taking into account relevant codes and standards and industry input. A conceptual design for the mechanical repair sleeve has been developed which meets the product definition.

  13. Effect of Titanium on the Mechanical Properties and Microstructure of Gray Cast Iron for Automotive Applications

    Science.gov (United States)

    Gelfi, M.; Gorini, D.; Pola, A.; La Vecchia, G. M.

    2016-09-01

    Lamellar gray cast iron, with a mainly pearlitic microstructure, is widely used in the automotive industry, mostly in the manufacturing of brake disks. This work analyzes in depth the effects of small variations of titanium content on the microstructure and mechanical properties of cast iron brake disks. For this purpose, eight different heats of EN-GJL-250 cast iron were selected, with a similar chemical composition but with different titanium contents, varying from 0.013 to 0.031%. The drops in mechanical strength and hardness values measured on the high-Ti samples were correlated to microstructural variations quantitatively observed by means of optical and scanning electron microscope. It was found that titanium combines to form titanium nitrides, suppressing the beneficial microstructural effects of nitrogen at solidification. Residual nitrogen, if present in sufficient quantity, promotes the nucleation of primary austenite from the liquid and the formation of a fine microstructure, with small eutectic cells and lower graphite content. Such a microstructure provides brake disks with better mechanical properties. The interpretation of results was further supported by thermal analysis and thermodynamic calculations.

  14. Mechanical behaviour of glass fiber weaven UD/high fluidity PA-based polymers for automotive applications

    Science.gov (United States)

    Dana, Hossein Ramezani; Gomina, Moussa; Bréard, Joël; Orange, Gilles

    2016-10-01

    This experimental work addresses the mechanical behavior of weaven UD glass fiber-thermoplastic composites designed for layered materials to be used in the automotive industry. The investigation was implemented in terms of the formulation of the PA66-based thermoplastic resins, the architecture of the fibrous reinforcement (warp spacer) and the glass fiber content. Longitudinal and transverse tensile tests results demonstrate the excellent mechanical behavior of these composites, which correlates with the rheological/permeability properties and wettability behaviour.

  15. Molecular mechanisms of DNA repair inhibition by caffeine

    Energy Technology Data Exchange (ETDEWEB)

    Selby, C.P.; Sancar, A. (Univ. of North Carolina School of Medicine, Chapel Hill (USA))

    1990-05-01

    Caffeine potentiates the mutagenic and lethal effects of genotoxic agents. It is thought that this is due, at least in some organisms, to inhibition of DNA repair. However, direct evidence for inhibition of repair enzymes has been lacking. Using purified Escherichia coli DNA photolyase and (A)BC excinuclease, we show that the drug inhibits photoreactivation and nucleotide excision repair by two different mechanisms. Caffeine inhibits photoreactivation by interfering with the specific binding of photolyase to damaged DNA, and it inhibits nucleotide excision repair by promoting nonspecific binding of the damage-recognition subunit, UvrA, of (A)BC excinuclease. A number of other intercalators, including acriflavin and ethidium bromide, appear to inhibit the excinuclease by a similar mechanism--that is, by trapping the UvrA subunit in nonproductive complexes on undamaged DNA.

  16. The mechanism of changes in the surface layer of grey cast iron automotive brake disc

    Directory of Open Access Journals (Sweden)

    Adam Polak

    2005-12-01

    Full Text Available The aim of the study was to create a model, describing the run of tribological processes in the surface layer of grey cast iron automotive brake discs. Grey cast iron discs mating with non-asbestos organic brake pads were chosen for the investigations, as the most widely used materials in car brakes. Samples for surface analysis were prepared from disc operating in stand and road conditions. Stand tests were pin-on-disc kind. Operating parameters for the stand tests were chosen on the basis of results of our earlier research. Topography of brake disc surface was evaluated by surface roughness measurements. The surface layer was examined with use of metallography and scanning electron microscopy. In order to differentiate structures of grey cast iron brake discs SE and BSE modes were used in scanning electron microscopy. Chemical investigations of samples were done by X-ray analysis linked with SEM. Studies showed influence of grey cast iron structures on tribological processes taking place in a brake friction pair. The surface layer of grey cast iron discs was described and features and functions of separated structures were presented. On the basis of the obtained results a physical model of friction mechanism was created. Special attention was paid to the influence of graphite on the run of tribological processes and mechanism of compaction and removal of wear debris.

  17. Platinum drugs and DNA repair mechanisms in lung cancer.

    Science.gov (United States)

    Bonanno, Laura; Favaretto, Adolfo; Rosell, Rafael

    2014-01-01

    The standard first-line treatment for around 80% of newly-diagnosed advanced non-small cell lung cancer (NSCLC) is chemotherapy. Currently, patients are allocated to chemotherapy on the basis of clinical conditions, comorbidities and histology. If feasible, platinum-based chemotherapy is considered as the most efficacious option. Due to the heterogeneity in terms of platinum-sensitivity among patients with NSCLC, great efforts have been made in order to identify molecular predictive markers of platinum resistance. Based on the mechanism of action of platinum, several components of DNA repair pathways have been investigated as potential predictive markers. The main DNA repair pathways involved in the repair of platinum-induced DNA damage are nucleotide excision repair and homologous recombination. The most studied potential predictive markers of platinum-sensitivity are Excision Repair Cross Complementing-1 (ERCC1) and Brest Cancer Type-I Susceptibility protein (BRCA1); however, increasing biological knowledge about DNA repair pathways suggests the potential clinical usefulness of integrated analysis of multiple DNA repair components.

  18. Mechanisms and functions of DNA mismatch repair

    Institute of Scientific and Technical Information of China (English)

    Guo MinLi

    2008-01-01

    DNA mismatch repair (MMR) is a highly conserved biological pathway that plays a key role in maintaining genomic stability. The specificity of MMR is primarily for base-base mismatches and insertion/deletion mispairs generated dur-ing DNA replication and recombination. MMR also suppresses homeologous recombination and was recently shown to play a role in DNA damage signaling in eukaryotic cells. Escherichia coli MutS and MutL and their eukaryotic homo-logs, MutSα and MutLα, respectively, are key players in MMR-associated genome maintenance. Many other protein components that participate in various DNA metabolic pathways, such as PCNA and RPA, are also essential for MMR. Defects in MMR are associated with genome-wide instability, predisposition to certain types of cancer including he-reditary non-polyposis colorectal cancer, resistance to certain chemotherapeutic agents, and abnormalities in meiosis and sterility in mammalian systems.

  19. EFFECTS OF TEMPERATURE AND ENVIRONMENT ON MECHANICAL PROPERTIES OF TWO CHOPPED-FIBER AUTOMOTIVE STRUCTURAL COMPOSITES

    Energy Technology Data Exchange (ETDEWEB)

    Ruggles-Wrenn, M.B.

    2003-10-06

    The Durability of Lightweight Composite Structures Project was established at Oak Ridge National Laboratory (ORNL) by the U.S. Department of Energy to provide the experimentally-based, durability-driven design guidelines necessary to assure long-term structural integrity of automotive composite components. The initial focus of the ORNL Durability Project was on composite materials consisting of polyurethane reinforced with E-glass. Current focus of the project is on composite materials reinforced with carbon fibers. The primary purpose of this report is to provide the individual specimen test date. Basic mechanical property testing and results for two chopped-fiber composite materials, one reinforced with glass- and the other with carbon fiber are provided. Both materials use the same polyurethane matrix. Preforms for both materials were produced using the P4 process. Behavioral trends, effects of temperature and environment, and corresponding design knockdown factors are established for both materials. Effects of prior short-time loads and of prior thermal cycling are discussed.

  20. Inter-rater agreement on self-reported exposure to ergonomic risk factors for the upper extremities among mechanic assemblers in an automotive industry

    National Research Council Canada - National Science Library

    d'Errico, Angelo; Fontana, Dario; Merogno, Angela

    2016-01-01

    ...) in a sample of mechanical assemblers of an automotive industry. cross-sectional study; reproducibility was assessed as interrater agreement of a composite index of ergonomic risk, estimated through the intraclass correlation coefficient (ICC...

  1. Mechanical properties of hyaline and repair cartilage studied by nanoindentation.

    Science.gov (United States)

    Franke, O; Durst, K; Maier, V; Göken, M; Birkholz, T; Schneider, H; Hennig, F; Gelse, K

    2007-11-01

    Articular cartilage is a highly organized tissue that is well adapted to the functional demands in joints but difficult to replicate via tissue engineering or regeneration. Its viscoelastic properties allow cartilage to adapt to both slow and rapid mechanical loading. Several cartilage repair strategies that aim to restore tissue and protect it from further degeneration have been introduced. The key to their success is the quality of the newly formed tissue. In this study, periosteal cells loaded on a scaffold were used to repair large partial-thickness cartilage defects in the knee joint of miniature pigs. The repair cartilage was analyzed 26 weeks after surgery and compared both morphologically and mechanically with healthy hyaline cartilage. Contact stiffness, reduced modulus and hardness as key mechanical properties were examined in vitro by nanoindentation in phosphate-buffered saline at room temperature. In addition, the influence of tissue fixation with paraformaldehyde on the biomechanical properties was investigated. Although the repair process resulted in the formation of a stable fibrocartilaginous tissue, its contact stiffness was lower than that of hyaline cartilage by a factor of 10. Fixation with paraformaldehyde significantly increased the stiffness of cartilaginous tissue by one order of magnitude, and therefore, should not be used when studying biomechanical properties of cartilage. Our study suggests a sensitive method for measuring the contact stiffness of articular cartilage and demonstrates the importance of mechanical analysis for proper evaluation of the success of cartilage repair strategies.

  2. MEMS (Micro-Electro-Mechanical Systems) for Automotive and Consumer Electronics

    Science.gov (United States)

    Marek, Jiri; Gómez, Udo-Martin

    MEMS sensors gained over the last two decades an impressive width of applications: (a) ESP: A car is skidding and stabilizes itself without driver intervention (b) Free-fall detection: A laptop falls to the floor and protects the hard drive by parking the read/write drive head automatically before impact. (c) Airbag: An airbag fires before the driver/occupant involved in an impending automotive crash impacts the steering wheel, thereby significantly reducing physical injury risk. MEMS sensors are sensing the environmental conditions and are giving input to electronic control systems. These crucial MEMS sensors are making system reactions to human needs more intelligent, precise, and at much faster reaction rates than humanly possible. Important prerequisites for the success of sensors are their size, functionality, power consumption, and costs. This technical progress in sensor development is realized by micro-machining. The development of these processes was the breakthrough to industrial mass-production for micro-electro-mechanical systems (MEMS). Besides leading-edge micromechanical processes, innovative and robust ASIC designs, thorough simulations of the electrical and mechanical behaviour, a deep understanding of the interactions (mainly over temperature and lifetime) of the package and the mechanical structures are needed. This was achieved over the last 20 years by intense and successful development activities combined with the experience of volume production of billions of sensors. This chapter gives an overview of current MEMS technology, its applications and the market share. The MEMS processes are described, and the challenges of MEMS, compared to standard IC fabrication, are discussed. The evolution of MEMS requirements is presented, and a short survey of MEMS applications is shown. Concepts of newest inertial sensors for ESP-systems are given with an emphasis on the design concepts of the sensing element and the evaluation circuit for achieving

  3. Evaluation of asbestos exposure within the automotive repair industry: a study involving removal of asbestos-containing body sealants and drive clutch replacement.

    Science.gov (United States)

    Blake, Charles L; Dotson, G Scott; Harbison, Raymond D

    2008-12-01

    Two independent assessments were performed of airborne asbestos concentrations generated during automotive repair work on vintage vehicles . The first involved removal of asbestos-containing seam sealant, and the second involved servicing of a drive clutch. Despite the relatively high concentrations (5.6-28%) of chrysotile fibers detected within bulk samples of seam sealant, the average asbestos concentration for personal breathing zone (PBZ) samples during seam sealant removal was 0.006 f/cc (fibers/cubic centimeter of air). Many other air samples contained asbestos at or below the analytical limit of detection (LOD). Pneumatic chiseling of the sealant material during removal resulted in 69% of area air samples containing asbestos. Use of this impact tool liberated more asbestos than hand scraping. Asbestos fibers were only detected in air samples collected during the installation of a replacement clutch. The highest asbestos corrected airborne fiber concentration observed during clutch installation was 0.0028 f/cc. This value is approximately 100 times lower than Occupational Safety and Health Administration's (OSHA) permissible exposure limit (PEL) of 0.1f/cc. The airborne asbestos concentrations observed during the servicing of vintage vehicles with asbestos-containing seam sealant and clutches are comparable to levels reported for repair work involving brake components and gaskets.

  4. A Survey on Optimal Signal Processing Techniques Applied to Improve the Performance of Mechanical Sensors in Automotive Applications

    Science.gov (United States)

    Hernandez, Wilmar

    2007-01-01

    In this paper a survey on recent applications of optimal signal processing techniques to improve the performance of mechanical sensors is made. Here, a comparison between classical filters and optimal filters for automotive sensors is made, and the current state of the art of the application of robust and optimal control and signal processing techniques to the design of the intelligent (or smart) sensors that today's cars need is presented through several experimental results that show that the fusion of intelligent sensors and optimal signal processing techniques is the clear way to go. However, the switch between the traditional methods of designing automotive sensors and the new ones cannot be done overnight because there are some open research issues that have to be solved. This paper draws attention to one of the open research issues and tries to arouse researcher's interest in the fusion of intelligent sensors and optimal signal processing techniques.

  5. Self-repair networks a mechanism design

    CERN Document Server

    Ishida, Yoshiteru

    2015-01-01

    This book describes the struggle to introduce a mechanism that enables next-generation information systems to maintain themselves. Our generation observed the birth and growth of information systems, and the Internet in particular. Surprisingly information systems are quite different from conventional (energy, material-intensive) artificial systems, and rather resemble biological systems (information-intensive systems). Many artificial systems are designed based on (Newtonian) physics assuming that every element obeys simple and static rules; however, the experience of the Internet suggests a different way of designing where growth cannot be controlled but self-organized with autonomous and selfish agents. This book suggests using game theory, a mechanism design in particular, for designing next-generation information systems which will be self-organized by collective acts with autonomous components. The challenge of mapping a probability to time appears repeatedly in many forms throughout this book. The book...

  6. Front-End Types. Automotive Mechanics. Steering & Suspension. Instructor's Guide [and] Student Guide.

    Science.gov (United States)

    Spignesi, B.

    This instructional package, one in a series of individualized instructional units on automotive steering and suspension, consists of a student guide and an instructor guide dealing with automobile front-end types. Covered in the module are three common types of passenger car front suspension systems and their major components as well as two types…

  7. An end-joining repair mechanism in Escherichia coli

    Science.gov (United States)

    Chayot, Romain; Montagne, Benjamin; Mazel, Didier; Ricchetti, Miria

    2010-01-01

    Bridging broken DNA ends via nonhomologous end-joining (NHEJ) contributes to the evolution and stability of eukaryote genomes. Although some bacteria possess a simplified NHEJ mechanism, the human commensal Escherichia coli is thought to rely exclusively on homology-directed mechanisms to repair DNA double-strand breaks (DSBs). We show here that laboratory and pathogenic E. coli strains possess a distinct end-joining activity that repairs DSBs and generates genome rearrangements. This mechanism, named alternative end-joining (A-EJ), does not rely on the key NHEJ proteins Ku and Ligase-D which are absent in E. coli. Differently from classical NHEJ, A-EJ is characterized by extensive end-resection largely due to RecBCD, by overwhelming usage of microhomology and extremely rare DNA synthesis. We also show that A-EJ is dependent on the essential Ligase-A and independent on Ligase-B. Importantly, mutagenic repair requires a functional Ligase-A. Although generally mutagenic, accurate A-EJ also occurs and is frequent in some pathogenic bacteria. Furthermore, we show the acquisition of an antibiotic-resistance gene via A-EJ, refuting the notion that bacteria gain exogenous sequences only by recombination-dependent mechanisms. This finding demonstrates that E. coli can integrate unrelated, nonhomologous exogenous sequences by end-joining and it provides an alternative strategy for horizontal gene transfer in the bacterial genome. Thus, A-EJ contributes to bacterial genome evolution and adaptation to environmental challenges. Interestingly, the key features of A-EJ also appear in A-NHEJ, an alternative end-joining mechanism implicated in chromosomal translocations associated with human malignancies, and we propose that this mutagenic repair might have originated in bacteria. PMID:20133858

  8. Defective DNA repair mechanisms in prostate cancer: impact of olaparib

    Directory of Open Access Journals (Sweden)

    De Felice F

    2017-03-01

    Full Text Available Francesca De Felice,1 Vincenzo Tombolini,1 Francesco Marampon,2 Angela Musella,3 Claudia Marchetti3 1Department of Radiotherapy, Policlinico Umberto I, “Sapienza” University of Rome, Rome, 2Department of Biotechnological and Applied Clinical Sciences, Laboratory of Radiobiology, University of L’Aquila, L’Aquila, 3Department of Gynecological and Obstetrical Sciences and Urological Sciences, “Sapienza” University of Rome, Rome, Italy Abstract: The field of prostate oncology has continued to change dramatically. It has truly become a field that is intensely linked to molecular genetic alterations, especially DNA-repair defects. Germline breast cancer 1 gene (BRCA1 and breast cancer 2 gene (BRCA2 mutations are implicated in the highest risk of prostate cancer (PC predisposition and aggressiveness. Poly adenosine diphosphate ribose polymerase (PARP proteins play a key role in DNA repair mechanisms and represent a valid target for new therapies. Olaparib is an oral PARP inhibitor that blocks DNA repair pathway and coupled with BRCA mutated-disease results in tumor cell death. In phase II clinical trials, including patients with advanced castration-resistant PC, olaparib seems to be efficacious and well tolerated. Waiting for randomized phase III trials, olaparib should be considered as a promising treatment option for PC. Keywords: prostate cancer, metastatic disease, castration resistant, BRCA, DNA-repair, PARP, olaparib

  9. The mechanism of changes in the surface layer of grey cast iron automotive brake disc

    OpenAIRE

    Adam Polak; Janusz Grzybek

    2005-01-01

    The aim of the study was to create a model, describing the run of tribological processes in the surface layer of grey cast iron automotive brake discs. Grey cast iron discs mating with non-asbestos organic brake pads were chosen for the investigations, as the most widely used materials in car brakes. Samples for surface analysis were prepared from disc operating in stand and road conditions. Stand tests were pin-on-disc kind. Operating parameters for the stand tests were chosen on the basis o...

  10. Failure mechanisms of lead/acid automotive batteries in service in the U.S.A.

    Science.gov (United States)

    Hoover, John H.; Boden, David P.

    Discarded lead/acid batteries were selected at random without regard to brand or condition and these were inspected and tested to determine the causes of failure. Samples were limited to 12-V automotive passenger-car batteries. Their age was determined from the manufacturing code and shipping date. In addition to the cause of failure, information on battery components and construction was also noted. Data are presented showing the principal modes of failure, the effect of geographical location, and the influence of grid alloy on life. In particular, the differences observed between those batteries utilizing calcium alloy for the positive grids and those using antimony alloy are discussed.

  11. FISITA 2012 World Automotive Congress

    CERN Document Server

    2013-01-01

    Proceedings of the FISITA 2012 World Automotive Congress are selected from nearly 2,000 papers submitted to the 34th FISITA World Automotive Congress, which is held by Society of Automotive Engineers of China (SAE-China ) and the International Federation of Automotive Engineering Societies (FISITA). This proceedings focus on solutions for sustainable mobility in all areas of passenger car, truck and bus transportation. Volume 8: Vehicle Design and Testing (II) focuses on: •Automotive Reliability Technology •Lightweight Design Technology •Design for Recycling •Dynamic Modeling •Simulation and Experimental Validation •Virtual Design, Testing and Validation •Testing of Components, Systems and Full Vehicle Above all researchers, professional engineers and graduates in fields of automotive engineering, mechanical engineering and electronic engineering will benefit from this book.   SAE-China is a national academic organization composed of enterprises and professionals who focus on research, design a...

  12. MEMS for automotive and aerospace applications

    CERN Document Server

    Kraft, Michael

    2013-01-01

    MEMS for automotive and aerospace applications reviews the use of Micro-Electro-Mechanical-Systems (MEMS) in developing solutions to the unique challenges presented by the automotive and aerospace industries.Part one explores MEMS for a variety of automotive applications. The role of MEMS in passenger safety and comfort, sensors for automotive vehicle stability control applications and automotive tire pressure monitoring systems are considered, along with pressure and flow sensors for engine management, and RF MEMS for automotive radar sensors. Part two then goes on to explore MEMS for

  13. A Survey on Optimal Signal Processing Techniques Applied to Improve the Performance of Mechanical Sensors in Automotive Applications

    Directory of Open Access Journals (Sweden)

    Wilmar Hernandez

    2007-01-01

    Full Text Available In this paper a survey on recent applications of optimal signal processing techniques to improve the performance of mechanical sensors is made. Here, a comparison between classical filters and optimal filters for automotive sensors is made, and the current state of the art of the application of robust and optimal control and signal processing techniques to the design of the intelligent (or smart sensors that today’s cars need is presented through several experimental results that show that the fusion of intelligent sensors and optimal signal processing techniques is the clear way to go. However, the switch between the traditional methods of designing automotive sensors and the new ones cannot be done overnight because there are some open research issues that have to be solved. This paper draws attention to one of the open research issues and tries to arouse researcher’s interest in the fusion of intelligent sensors and optimal signal processing techniques.

  14. EFFECTS OF TEMPERATURE AND ENVIRONMENT ON MECHANICAL PROPERTIES OF TWO CONTINUOUS CARBON-FIBER AUTOMOTIVE STRUCTURAL COMPOSITES

    Energy Technology Data Exchange (ETDEWEB)

    Ruggles-Wrenn, M.B.

    2003-10-06

    The Durability of Carbon-Fiber Composites Project was established at Oak Ridge National Laboratory (ORNL) by the U.S. Department of Energy to develop experimentally based, durability-driven design guidelines to assure the long-term (15-year) structural integrity of carbon-fiber-based composite systems for automotive structural applications. The project addressed characterization and modeling the durability of a progression of carbon-reinforced thermoset materials, each of which has the same urethane matrix. The primary purpose of this report is to provide the individual specimen test data. Basic mechanical property testing and results for a reference [{+-}45{sup o}]{sub 3S} crossply composite and a quasi-isotropic, [0/90{sup o}/{+-}45{sup o}]{sub S} version of the reference crossply are provided. The matrix and individual {+-}45{sup o} stitch-bonded mats are the same in both cases. Although the composite utilized aerospace-grade carbon-fiber reinforcement, it was made by a rapid-molding process suitable for high-volume automotive use. Behavioral trends, effects of temperature and environment, and corresponding design knockdown factors are established for both materials. The reference crossply is highly anisotropic with two dominant fiber orientations--0/90{sup o} and {+-}45{sup o}. Therefore properties were developed for both orientations.

  15. Eukaryotic nucleotide excision repair: from understanding mechanisms to influencing biology

    Institute of Scientific and Technical Information of China (English)

    Sarah C Shuck; Emily A Short; John J Turchi

    2008-01-01

    Repair of bulky DNA adducts by the nucleotide excision repair (NER) pathway is one of the more versatile DNA repair pathways for the removal of DNA lesions. There are two subsets of the NER pathway, global genomic-NER (GG-NER) and transcription-coupled NER (TC-NER), which differ only in the step involving recognition of the DNA lesion. Following recognition of the damage, the sub-pathways then converge for the incision/excision steps and subsequent gap filling and ligation steps. This review will focus on the GGR sub-pathway of NER while the TCR sub-pathway will be covered in another article in this issue. The ability of the NER pathway to repair a wide array of adducts stems, in part, from the mechanisms involved in the initial recognition step of the damaged DNA and results in NER impacting an equally wide array of human physiological responses and events. In this review, the impact of NER on carcinogenesis, neurological function, sensitivity to environmental factors and sensitivity to cancer therapeutics will be discussed. The knowledge generated in our understanding of the NER pathway over the past 40 years has resulted from advances in the fields of animal model systems, mammalian genetics and in vitro biochemistry, as well as from reconstitution studies and structural analyses of the proteins and enzymes that participate in this pathway. Each of these avenues of research has contributed significantly to our understanding of how the NER pathway works and how alterations in NER activity, both positive and negative, influence human biology.

  16. SELECTION METHOD FOR AUTOMOTIVE PARTS RECONDITIONING

    Directory of Open Access Journals (Sweden)

    Dan Florin NITOI

    2015-05-01

    Full Text Available Paper presents technological methods for metal deposition, costs calculation and clasification for the main process that helps in automotive technologies to repair or to increase pieces properties. Paper was constructed based on many technological experiments that starts from practicans and returns to them. The main aim is to help young engineers or practicians engineers to choose the proper reconditioning process with the best information in repairing pieces from automotive industry.

  17. DNA repair mechanisms in eukaryotes: Special focus in Entamoeba histolytica and related protozoan parasites.

    Science.gov (United States)

    López-Camarillo, César; Lopez-Casamichana, Mavil; Weber, Christian; Guillen, Nancy; Orozco, Esther; Marchat, Laurence A

    2009-12-01

    Eukaryotic cell viability highly relies on genome stability and DNA integrity maintenance. The cellular response to DNA damage mainly consists of six biological conserved pathways known as homologous recombination repair (HRR), non-homologous end-joining (NHEJ), base excision repair (BER), mismatch repair (MMR), nucleotide excision repair (NER), and methyltransferase repair that operate in a concerted way to minimize genetic information loss due to a DNA lesion. Particularly, protozoan parasites survival depends on DNA repair mechanisms that constantly supervise chromosomes to correct damaged nucleotides generated by cytotoxic agents, host immune pressure or cellular processes. Here we reviewed the current knowledge about DNA repair mechanisms in the most relevant human protozoan pathogens. Additionally, we described the recent advances to understand DNA repair mechanisms in Entamoeba histolytica with special emphasis in the use of genomic approaches based on bioinformatic analysis of parasite genome sequence and microarrays technology.

  18. Fragile DNA Repair Mechanism Reduces Ageing in Multicellular Model

    DEFF Research Database (Denmark)

    Bendtsen, Kristian Moss; Juul, Jeppe Søgaard; Trusina, Ala

    2012-01-01

    DNA damages, as well as mutations, increase with age. It is believed that these result from increased genotoxic stress and decreased capacity for DNA repair. The two causes are not independent, DNA damage can, for example, through mutations, compromise the capacity for DNA repair, which in turn...... to DNA damage can undergo full repair, go apoptotic, or accumulate mutations thus reducing DNA repair capacity. Our model predicts that at the tissue level repair rate does not continuously decline with age, but instead has a characteristic extended period of high and non-declining DNA repair capacity...... of compromised cells, thus freeing the space for healthy peers. This finding might be a first step toward understanding why a mutation in single DNA repair protein (e.g. Wrn or Blm) is not buffered by other repair proteins and therefore, leads to severe ageing disorders...

  19. Mechanism of DNA loading by the DNA repair helicase XPD.

    Science.gov (United States)

    Constantinescu-Aruxandei, Diana; Petrovic-Stojanovska, Biljana; Penedo, J Carlos; White, Malcolm F; Naismith, James H

    2016-04-07

    The xeroderma pigmentosum group D (XPD) helicase is a component of the transcription factor IIH complex in eukaryotes and plays an essential role in DNA repair in the nucleotide excision repair pathway. XPD is a 5' to 3' helicase with an essential iron-sulfur cluster. Structural and biochemical studies of the monomeric archaeal XPD homologues have aided a mechanistic understanding of this important class of helicase, but several important questions remain open. In particular, the mechanism for DNA loading, which is assumed to require large protein conformational change, is not fully understood. Here, DNA binding by the archaeal XPD helicase from Thermoplasma acidophilum has been investigated using a combination of crystallography, cross-linking, modified substrates and biochemical assays. The data are consistent with an initial tight binding of ssDNA to helicase domain 2, followed by transient opening of the interface between the Arch and 4FeS domains, allowing access to a second binding site on helicase domain 1 that directs DNA through the pore. A crystal structure of XPD from Sulfolobus acidocaldiarius that lacks helicase domain 2 has an otherwise unperturbed structure, emphasizing the stability of the interface between the Arch and 4FeS domains in XPD.

  20. Mechanism of DNA loading by the DNA repair helicase XPD

    Science.gov (United States)

    Constantinescu-Aruxandei, Diana; Petrovic-Stojanovska, Biljana; Penedo, J. Carlos; White, Malcolm F.; Naismith, James H.

    2016-01-01

    The xeroderma pigmentosum group D (XPD) helicase is a component of the transcription factor IIH complex in eukaryotes and plays an essential role in DNA repair in the nucleotide excision repair pathway. XPD is a 5′ to 3′ helicase with an essential iron–sulfur cluster. Structural and biochemical studies of the monomeric archaeal XPD homologues have aided a mechanistic understanding of this important class of helicase, but several important questions remain open. In particular, the mechanism for DNA loading, which is assumed to require large protein conformational change, is not fully understood. Here, DNA binding by the archaeal XPD helicase from Thermoplasma acidophilum has been investigated using a combination of crystallography, cross-linking, modified substrates and biochemical assays. The data are consistent with an initial tight binding of ssDNA to helicase domain 2, followed by transient opening of the interface between the Arch and 4FeS domains, allowing access to a second binding site on helicase domain 1 that directs DNA through the pore. A crystal structure of XPD from Sulfolobus acidocaldiarius that lacks helicase domain 2 has an otherwise unperturbed structure, emphasizing the stability of the interface between the Arch and 4FeS domains in XPD. PMID:26896802

  1. 中职汽车维修专业中物理教学的探索与思考%Exploration and Reflection on Physics Teaching of Automotive Repair Major in Secondary Vocational School

    Institute of Scientific and Technical Information of China (English)

    古静

    2011-01-01

    In view of the current vocational school students',especially automotive repair majors' "tiredness" in physics,this paper explores a teaching strategy fit for secondary vocational automotive repair majors' physics teaching and finds out feasible teaching methods for this course,so as to make class teaching successful,constantly improve teaching quality,cultivate students' innovative thinking and their learning interest as well.%针对目前中职学校学生,尤其是汽修专业学生物理课程普遍"厌学"的现象,为了使物理课堂教学顺利进行,不断提高教学质量,并致力于培养学生创新思维,培养学生的学习兴趣,本文结合我自身的教学实践,探索出符合中职汽修专业学生的物理教学策略,找到切合实际的教学方法。

  2. Personal Achievement Mathematics: Automotive.

    Science.gov (United States)

    Baenziger, Betty

    Utilizing word problems relevant to automotive mechanics, this workbook presents a concept-oriented approach to competency development in 13 areas of basic mathematics: (1) the expression of numbers as figures and words; (2) the addition, subtraction, multiplication, and division of whole numbers, fractions, and decimals; (3) scientific notation;…

  3. Automotive websites

    CERN Document Server

    Jensen, Todd A

    2006-01-01

    For anyone buying a new car, restoring an old favorite, collecting license plates or looking for motorsports information, the internet is the place to go and this is the book to help you get there. Now with over 650 internet addresses, this expanded and updated guide provides detailed descriptions and reviews of the biggest, best and most interesting automotive websites on the net. Beginning with a brief internet history and helpful hints, it aids the novice (or not so novice) user in picking through the countless automotive sites on the internet. Websites are arranged by topics such as afterm

  4. Surgical repair of chronic tears of the hip abductor mechanism.

    Science.gov (United States)

    Davies, Hywel; Zhaeentan, Sohelia; Tavakkolizadeh, Adel; Janes, Gregory

    2009-01-01

    Lateral sided hip pain frequently presents to the orthopaedic clinic. The most common cause of this pain is trochanteric bursitis. This usually improves with conservative treatment. In a few cases it doesn't settle and warrants further investigation and treatment. We present a series of 28 patients who underwent MRI scanning for such pain, 16 were found to have a tear of their abductors. All 16 underwent surgical repair using multiple soft tissue anchors inserted into the greater trochanter of the hip to reattach the abductors. There were 15 females and 1 male. All patients completed a self-administered questionnaire pre-operatively and 1 year post-operatively. Data collected included: A visual analogue score for hip pain, Charnley modification of the Merle D'Aubigne and Postel hip score, Oxford hip score, Kuhfuss score of Trendelenburg and SF36 scores.Of the 16 patients who underwent surgery 5 had a failure of surgical treatment. There were 4 re ruptures, 3 of which were revised and 1 deep infection which required debridement. In the remaining 11 patients there were statistically significant improvements in hip symptoms. The mean change in visual analogue score was 5 out of 10 (p=0.0024) The mean change of Oxford hip score was 20.5 (p=0.00085). The mean improvement in SF-36 PCS was 8.5 (P=0.0020) and MCS 13.7 (P=0.134). 6 patients who had a Trendelenburg gait pre-surgery had normal gait 1 year following surgery.We conclude that hip abductor mechanism tear is a frequent cause of recalcitrant trochanteric pain that should be further investigated with MRI scanning. Surgical repair is a successful operation for reduction of pain and improvement of function. However there is a relatively high failure rate.

  5. Comparative Evaluation of Cast Aluminum Alloys for Automotive Cylinder Heads: Part II—Mechanical and Thermal Properties

    Science.gov (United States)

    Roy, Shibayan; Allard, Lawrence F.; Rodriguez, Andres; Porter, Wallace D.; Shyam, Amit

    2017-05-01

    The first part of this study documented the as-aged microstructure of five cast aluminum alloys namely, 206, 319, 356, A356, and A356+0.5Cu, that are used for manufacturing automotive cylinder heads (Roy et al. in Metall Mater Trans A, 2016). In the present part, we report the mechanical response of these alloys after they have been subjected to various levels of thermal exposure. In addition, the thermophysical properties of these alloys are also reported over a wide temperature range. The hardness variation due to extended thermal exposure is related to the evolution of the nano-scale strengthening precipitates for different alloy systems (Al-Cu, Al-Si-Cu, and Al-Si). The effect of strengthening precipitates (size and number density) on the mechanical response is most obvious in the as-aged condition, which is quantitatively demonstrated by implementing a strength model. Significant coarsening of precipitates from long-term heat treatment removes the strengthening efficiency of the nano-scale precipitates for all these alloys systems. Thermal conductivity of the alloys evolve in an inverse manner with precipitate coarsening compared to the strength, and the implications of the same for the durability of cylinder heads are noted.

  6. Interplay between mechanisms of damage and repair in multiple sclerosis.

    Science.gov (United States)

    Stadelmann, Christine; Brück, Wolfgang

    2008-03-01

    The neuropathology of multiple sclerosis is characterised by focal damage to white matter. However, tissue damage is also present in the cortical grey matter, with a particularly high prevalence of cortical demyelination being observed in secondary progressive and primary progressive forms of the disease. The presence of meningeal B-cell follicle-like structures, which frequently appear during the secondary progressive phase of disease, may be involved in the formation of these subpial cortical lesions. Diffuse white matter inflammation accompanied by axonal damage can also be observed in normal appearing white matter and, again, this is more prominent in chronic progressive forms of multiple sclerosis than in acute stages of disease. Axonal damage is a particularly important component of the pathology of multiple sclerosis and appears to be a critical determinant of clinical outcome. Axons appear to become vulnerable to injury as a result of loss of their myelin sheaths. Remyelination represents an important mechanism of tissue repair in multiple sclerosis and already occurs at an early stage of lesion development and in both white and grey matter lesions. The extent of remyelination appears to be greater in cortical lesions and in lesions further from the ventricles. There is important heterogeneity between patients in terms of the extent of remyelination, which may reflect underlying differences in pathogenetic mechanisms between patients.

  7. Impact of occupational mechanical exposures on risk of lateral and medial inguinal hernia requiring surgical repair

    DEFF Research Database (Denmark)

    Vad, Marie Vestergaard; Frost, Poul; Bay-Nielsen, Morten;

    2012-01-01

    We undertook a register-based cohort study to evaluate exposure-response relations between cumulative occupational mechanical exposures, and risk of lateral and medial inguinal hernia repair.......We undertook a register-based cohort study to evaluate exposure-response relations between cumulative occupational mechanical exposures, and risk of lateral and medial inguinal hernia repair....

  8. 机构创新在汽车设计上的应用%Application of Mechanisms Innovation in Automotive Design

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      从汽车功能设计及机构的合理优化两方面对创新机构进行深入分析,阐述机构创新在解决汽车应用出现的问题及改善性能方面的应用。得出利用中国传统机构的创新及组合再生,设计出具有中国传统特色的汽车,可以提升我国民族汽车品牌的竞争力。%Through deeply analyzing mechanisms innovation from 2 aspects of design of automotive function and reasonable optimization of mechanisms, the paper was expounded application of mechanisms innovation in automotive design. The paper was designed traditional Chinese characteristics automotive by using innovation and combination of Chinese traditional mecha-nism, which improved competitiveness of national automobile brand.

  9. Mechanism and Durability of Repair Systems in Polymer-Modified Cement Mortars

    Directory of Open Access Journals (Sweden)

    Ru Wang

    2015-01-01

    Full Text Available This paper investigated the mechanism and durability of repair systems made of ordinary cement-based repair mortar and three kinds of polymer-modified repair mortars with old concrete, SBR dispersion, SAE dispersion, and SAE powder. By comparing the bonding properties of mortars before and after erosion, it was found that polymers could effectively improve the durability of the repair system and SAE powder had the best improvement. Micromorphology study of the repair mortar and the interface of repair mortar with old concrete through SEM showed that the polymer film formed from SAE powder whatever in the mortar or at the interface was dense and tough, the film formed from SAE dispersion was loose and weak, while the film formed from SBR dispersion was in between them, which explained the difference in the tensile bond strength and the durability of the repair systems.

  10. Control of gene editing by manipulation of DNA repair mechanisms.

    Science.gov (United States)

    Danner, Eric; Bashir, Sanum; Yumlu, Saniye; Wurst, Wolfgang; Wefers, Benedikt; Kühn, Ralf

    2017-04-03

    DNA double-strand breaks (DSBs) are produced intentionally by RNA-guided nucleases to achieve genome editing through DSB repair. These breaks are repaired by one of two main repair pathways, classic non-homologous end joining (c-NHEJ) and homology-directed repair (HDR), the latter being restricted to the S/G2 phases of the cell cycle and notably less frequent. Precise genome editing applications rely on HDR, with the abundant c-NHEJ formed mutations presenting a barrier to achieving high rates of precise sequence modifications. Here, we give an overview of HDR- and c-NHEJ-mediated DSB repair in gene editing and summarize the current efforts to promote HDR over c-NHEJ.

  11. Deploying time investigation of automotive active hood lift mechanism with different design parameters of hinge part

    Directory of Open Access Journals (Sweden)

    Tae-Hoon Lee

    2016-04-01

    Full Text Available This article investigates the change in deploying time of an active hood lift mechanism of a passenger vehicle activated by a gunpowder actuator. Especially, in this work, the deploying time is investigated by changing the principal design parameters of the hinge part of the hood mechanism. After briefly introducing the working principle of the active hood lift mechanism operated by the gunpowder actuator, the governing dynamic equations of the active hood lift mechanism are formulated for deploying motion. Subsequently, using the governing equations of motion, the response time for deploying the hood lift mechanism is investigated by changing several geometric locations such as the location of actuator. Then, a comparison is made of the total response time to completely deploy the hood lift mechanism with the existing conventional hood lift mechanism and the proposed active hood lift mechanism. In addition, the workable driving speed of the proposed active hood lift mechanism is compared with the conventional one by changing the powder volume of the actuator.

  12. Microstructure and Mechanical Properties of Fly Ash Particulate Reinforced in LM6 for Energy Enhancement in Automotive Applications

    Science.gov (United States)

    Ervina Efzan, M. N.; Siti Syazwani, N.; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    Fly ash has gathered widespread attention as a potential reinforcement for aluminium matrix composites (AMCs) to enhance the properties and reduce the cost of production. Aluminium alloy LM6 reinforced with three different amounts (0, 4, 5 and 6 wt. %) of fly ash particle that were prepared by compo-casting method. The fly ash particles were incorporated into semi-solid state of LM6 melt. In this study, the microstructure of prepared AMCs with the homogenous distribution of fly ash was analysed using optical microscope. The microstructure having refinement of structure with the decreasing of Si-needle structure and increasing the area of eutectic a-Al matrix as shown in figure. Besides, as the increasing amount of fly ash incorporated, there are more petal-like dark structure existed in the microstructure. The density of the AMCs decreased as the incorporation of fly ash increased. While the hardness and ultimate tensile strength of the AMCs increased with the incorporation of fly ash. The addition of fly ash particles improved the physical and mechanical properties of the AMCs. Thus lead to improve the energy consumption in automotive parts.

  13. A Descriptive Study on the Impact of Knowledge Creation Mechanism on Organizational Performance: A Case study in Malaysian Automotive industry

    Directory of Open Access Journals (Sweden)

    Hassan Bihamta

    2012-07-01

    Full Text Available The process of continues improvement is one of the significant and predominant programs in most of the manufacturers all over the world. These struggles constantly look for improvement breakthrough that it is necessary for achieving efficiency and effectiveness to maintain sustainable quality processes and competitive advantages as well. Moreover, quality is one of the major competitive advantages that it is crucial for improving efficiency. Nowadays, many of company in global market are developing programs to achieve and deploying this process. In this study, we are going to illustrate the influence of knowledge creation mechanism on improving the quality process and its impact on organizational performance. This study applied the framework from Nonaka (1994, called SECI model for creating knowledge. This research focused on an automotive manufacturer companies. Besides, the roles of six sigma and continuous improvement process (CIP were clearly discussed. Moreover, the profound roles of knowledge creation in terms of socialization, externalization, combination and internalization as a model on quality process were examined.

  14. Effects of scuba diving on vascular repair mechanisms.

    Science.gov (United States)

    Culic, Vedrana Cikes; Van Craenenbroeck, Emeline; Muzinic, Nikolina Rezic; Ljubkovic, Marko; Marinovic, Jasna; Conraads, Viviane; Dujic, Zeljko

    2014-01-01

    A single air dive causes transient endothelial dysfunction. Endothelial progenitor cells (EPCs) and circulating angiogenic cells (CAC) contribute synergistically to endothelial repair. In this study (1) the acute effects of diving on EPC numbers and CAC migration and (2) the influence of the gas mixture (air/nitrox-36) was investigated. Ten divers performed two dives to 18 meters on Day (D) 1 and D3, using air. After 15 days, dives were repeated with nitrox-36. Blood sampling took place before and immediately after diving. Circulating EPCs were quantified by flow cytometry, CAC migration of culture was assessed on D7. When diving on air, a trend for reduced EPC numbers is observed post-dive, which is persistent on D1 and D3. CAC migration tends to improve acutely following diving. These effects are more pronounced with nitrox-36 dives. Diving acutely affects EPC numbers and CAC function, and to a larger extent when diving with nitrox-36. The diving-induced oxidative stress may influence recruitment or survival of EPC. The functional improvement of CAC could be a compensatory mechanism to maintain endothelial homeostasis.

  15. The Impact of Hedgehog Signaling Pathway on DNA Repair Mechanisms in Human Cancer

    Directory of Open Access Journals (Sweden)

    Erhong Meng

    2015-07-01

    Full Text Available Defined cellular mechanisms have evolved that recognize and repair DNA to protect the integrity of its structure and sequence when encountering assaults from endogenous and exogenous sources. There are five major DNA repair pathways: mismatch repair, nucleotide excision repair, direct repair, base excision repair and DNA double strand break repair (including non-homologous end joining and homologous recombination repair. Aberrant activation of the Hedgehog (Hh signaling pathway is a feature of many cancer types. The Hh pathway has been documented to be indispensable for epithelial-mesenchymal transition, invasion and metastasis, cancer stemness, and chemoresistance. The functional transcription activators of the Hh pathway include the GLI proteins. Inhibition of the activity of GLI can interfere with almost all DNA repair types in human cancer, indicating that Hh/GLI functions may play an important role in enabling tumor cells to survive lethal types of DNA damage induced by chemotherapy and radiotherapy. Thus, Hh signaling presents an important therapeutic target to overcome DNA repair-enabled multi-drug resistance and consequently increase chemotherapeutic response in the treatment of cancer.

  16. The Impact of Hedgehog Signaling Pathway on DNA Repair Mechanisms in Human Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Erhong; Hanna, Ann; Samant, Rajeev S.; Shevde, Lalita A., E-mail: lsamant@uab.edu [Department of Pathology, Comprehensive Cancer Center, University of Alabama at Birmingham, WTI320D, 1824 6th Avenue South, Birmingham, AL 35233 (United States)

    2015-07-21

    Defined cellular mechanisms have evolved that recognize and repair DNA to protect the integrity of its structure and sequence when encountering assaults from endogenous and exogenous sources. There are five major DNA repair pathways: mismatch repair, nucleotide excision repair, direct repair, base excision repair and DNA double strand break repair (including non-homologous end joining and homologous recombination repair). Aberrant activation of the Hedgehog (Hh) signaling pathway is a feature of many cancer types. The Hh pathway has been documented to be indispensable for epithelial-mesenchymal transition, invasion and metastasis, cancer stemness, and chemoresistance. The functional transcription activators of the Hh pathway include the GLI proteins. Inhibition of the activity of GLI can interfere with almost all DNA repair types in human cancer, indicating that Hh/GLI functions may play an important role in enabling tumor cells to survive lethal types of DNA damage induced by chemotherapy and radiotherapy. Thus, Hh signaling presents an important therapeutic target to overcome DNA repair-enabled multi-drug resistance and consequently increase chemotherapeutic response in the treatment of cancer.

  17. Process Modeling of Low-Pressure Die Casting of Aluminum Alloy Automotive Wheels

    Science.gov (United States)

    Reilly, C.; Duan, J.; Yao, L.; Maijer, D. M.; Cockcroft, S. L.

    2013-09-01

    Although on initial inspection, the aluminum alloy automotive wheel seems to be a relatively simple component to cast based on its shape, further insight reveals that this is not the case. Automotive wheels are in a select group of cast components that have strict specifications for both mechanical and aesthetic characteristics due to their important structural requirements and their visibility on a vehicle. The modern aluminum alloy automotive wheel continues to experience tightened tolerances relating to defects to improve mechanical performance and/or the physical appearance. Automotive aluminum alloy wheels are assessed against three main criteria: wheel cosmetics, mechanical performance, and air tightness. Failure to achieve the required standards in any one of these categories will lead to the wheel either requiring costly repair or being rejected and remelted. Manufacturers are becoming more reliant on computational process modeling as a design tool for the wheel casting process. This article discusses and details examples of the use of computational process modeling as a predictive tool to optimize the casting process from the standpoint of defect minimization with the emphasis on those defects that lead to failure of aluminum automotive wheels, namely, macroporosity, microporosity, and oxide films. The current state of applied computational process modeling and its limitations with regard to wheel casting are discussed.

  18. Automotive sensors

    Science.gov (United States)

    Marek, Jiri; Illing, Matthias

    2003-01-01

    Sensors are an essential component of most electronic systems in the car. They deliver input parameters for comfort features, engine and emission control as well as for the active and passive safety systems. New technologies such as silicon micromachining play an important role for the introduction of these sensors in all vehicle classes. The importance and use of these sensor technologies in today"s automotive applications will be shown in this article. Finally an outlook on important current developments and new functions in the car will be given.

  19. Thermo-Mechanical Compatibility of Viscoelastic Mortars for Stone Repair

    Directory of Open Access Journals (Sweden)

    Thibault Demoulin

    2016-01-01

    Full Text Available The magnitude of the thermal stresses that originate in an acrylic-based repair material used for the reprofiling of natural sandstone is analyzed. This kind of artificial stone was developed in the late 1970s for its peculiar property of reversibility in an organic solvent. However, it displays a high thermal expansion coefficient, which can be a matter of concern for the durability either of the repair or of the underlying original stone. To evaluate this risk we propose an analytical solution that considers the viscoelasticity of the repair layer. The temperature profile used in the numerical evaluation has been measured in a church where artificial stone has been used in a recent restoration campaign. The viscoelasticity of the artificial stone has been characterized by stress relaxation experiments. The numerical analysis shows that the relaxation time of the repair mortar, originating from a low T g , allows relief of most of the thermal stresses. It explains the good durability of this particular repair material, as observed by the practitioners, and provides a solid scientific basis for considering that the problem of thermal expansion mismatch is not an issue for this type of stone under any possible conditions of natural exposure.

  20. Cell resistance to the Cytolethal Distending Toxin involves an association of DNA repair mechanisms

    Science.gov (United States)

    Bezine, Elisabeth; Malaisé, Yann; Loeuillet, Aurore; Chevalier, Marianne; Boutet-Robinet, Elisa; Salles, Bernard; Mirey, Gladys; Vignard, Julien

    2016-01-01

    The Cytolethal Distending Toxin (CDT), produced by many bacteria, has been associated with various diseases including cancer. CDT induces DNA double-strand breaks (DSBs), leading to cell death or mutagenesis if misrepaired. At low doses of CDT, other DNA lesions precede replication-dependent DSB formation, implying that non-DSB repair mechanisms may contribute to CDT cell resistance. To address this question, we developed a proliferation assay using human cell lines specifically depleted in each of the main DNA repair pathways. Here, we validate the involvement of the two major DSB repair mechanisms, Homologous Recombination and Non Homologous End Joining, in the management of CDT-induced lesions. We show that impairment of single-strand break repair (SSBR), but not nucleotide excision repair, sensitizes cells to CDT, and we explore the interplay of SSBR with the DSB repair mechanisms. Finally, we document the role of the replicative stress response and demonstrate the involvement of the Fanconi Anemia repair pathway in response to CDT. In conclusion, our work indicates that cellular survival to CDT-induced DNA damage involves different repair pathways, in particular SSBR. This reinforces a model where CDT-related genotoxicity primarily involves SSBs rather than DSBs, underlining the importance of cell proliferation during CDT intoxication and pathogenicity. PMID:27775089

  1. The 2015 Nobel Prize in Chemistry The Discovery of Essential Mechanisms that Repair DNA Damage.

    Science.gov (United States)

    Lindahl, Tomas; Modrich, Paul; Sancar, Aziz

    2016-01-01

    The Royal Swedish Academy awarded the Nobel Prize in Chemistry for 2015 to Tomas Lindahl, Paul Modrich and Aziz Sancar for their discoveries in fundamental mechanisms of DNA repair. This pioneering research described three different essential pathways that correct DNA damage, safeguard the integrity of the genetic code to ensure its accurate replication through generations, and allow proper cell division. Working independently of each other, Tomas Lindahl, Paul Modrich and Aziz Sancar delineated the mechanisms of base excision repair, mismatch repair and nucleotide excision repair, respectively. These breakthroughs challenged and dismissed the early view that the DNA molecule was very stable, paving the way for the discovery of human hereditary diseases associated with distinct DNA repair deficiencies and a susceptibility to cancer. It also brought a deeper understanding of cancer as well as neurodegenerative or neurological diseases, and let to novel strategies to treat cancer.

  2. Refrigeration Controls: Electrical & Mechanical; Appliance Repair 3: 9027.02.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    This booklet outlines a course designed to equip major appliance service students with the fundamental knowledge and understanding of procedures, basic electrical circuitry, and nomenclatures of components necessary in successfully tracing a circuit and repairing or replacing a malfunctioning component. Course content includes goals, specific…

  3. The mechansims by which solute nitrogen affects phase transformations and mechanical properties of automotive dual-phase sheet steel

    Science.gov (United States)

    Brown, Tyson W.

    Dual-phase steels have seen increased use in automotive applications in recent years, in order to meet the goals of weight reduction and occupant safety. Variations in nitrogen content that may be encountered in steel sourced from a basic oxygen furnace process compared to an electric arc furnace process require that dual-phase steel producers understand the ways that nitrogen affects processing and properties. In the current work, the distribution of nitrogen was investigated in a dual-phase steel with a base chemistry of 0.1 C, 2.0 Mn, 0.2 Cr, 0.2 Mo (wt pct) across a range of nitrogen contents (30-159 ppm) with Al (0.2 and 0.08 wt pct), and Ti (0.02 wt pct) additions used for precipitation control of nitrogen amounts. The distribution of nitrogen amongst trapping sites, including precipitates, grain boundaries, dislocations, and interstitial sites (away from other types of defects) was determined from a combination of electrolytic dissolution, internal friction, and three-dimensional atom probe tomography experiments. Various mechanisms by which different amounts and locations of nitrogen affect phase transformations and mechanical properties were identified from quantitative metallography, dilatometric measurement of phase transformations, tensile testing, and nanoindentation hardness testing. Results indicate nitrogen that is not precipitated with Ti or Al (free nitrogen) partitions to austenite (and thus martensite) during typical intercritical annealing treatments, and is mostly contained in Cottrell atmospheres in martensite. Due to the austenite stabilizing effect of nitrogen, the presence of free nitrogen during intercritical annealing leads to a higher austenite fraction in certain conditions. Thus, the presence of free nitrogen in a dual-phase microstructure will lead to an increase in tensile and yield strengths from both an increase in martensite fraction, and an increase in martensite hardness due to solid solution strengthening. Despite the presence

  4. DNA DSB repair pathway choice: an orchestrated handover mechanism.

    Science.gov (United States)

    Kakarougkas, A; Jeggo, P A

    2014-03-01

    DNA double strand breaks (DSBs) are potential lethal lesions but can also lead to chromosome rearrangements, a step promoting carcinogenesis. DNA non-homologous end-joining (NHEJ) is the major DSB rejoining process and occurs in all cell cycle stages. Homologous recombination (HR) can additionally function to repair irradiation-induced two-ended DSBs in G2 phase. In mammalian cells, HR predominantly uses a sister chromatid as a template for DSB repair; thus HR functions only in late S/G2 phase. Here, we review current insight into the interplay between HR and NHEJ in G2 phase. We argue that NHEJ represents the first choice pathway, repairing approximately 80% of X-ray-induced DSBs with rapid kinetics. However, a subset of DSBs undergoes end resection and repair by HR. 53BP1 restricts resection, thereby promoting NHEJ. During the switch from NHEJ to HR, 53BP1 is repositioned to the periphery of enlarged irradiation-induced foci (IRIF) via a BRCA1-dependent process. K63-linked ubiquitin chains, which also form at IRIF, are also repositioned as well as receptor-associated protein 80 (RAP80), a ubiquitin binding protein. RAP80 repositioning requires POH1, a proteasome component. Thus, the interfacing barriers to HR, 53BP1 and RAP80 are relieved by POH1 and BRCA1, respectively. Removal of RAP80 from the IRIF core is required for loss of the ubiquitin chains and 53BP1, and for efficient replication protein A foci formation. We propose that NHEJ is used preferentially to HR because it is a compact process that does not necessitate extensive chromatin changes in the DSB vicinity.

  5. Biological effects of exposure to intermediate neutron and repair mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Utsumi, Hiroshi; Sasaki, Masao [Kyoto Univ. (Japan); Onishi, Takeo; Onizuka, Masahiko

    2000-01-01

    An investigation was made on cytotoxic effects of neutron capture using chicken B-cell line mutants, DT40, KURO{sup -/-}, RAD54 {sup -/-} and KU70{sup -/-} / RAD54{sup -/-}. Suspensions of these cells were exposed to two times X-radiation at various doses and the cell surviving was evaluated. The sensitivity to radiation was highest in the double defective mutant, KU70{sup -/-} / RAD54{sup -/-} and followed by that of RAD54 {sup -/-}, a homologous recombination mutant, whereas KURO {sup -/-} cell, a non-homologous end-joining mutant showed a peculiar surviving curve composed of two phases and the cell was highly sensitive to a low-dose radiation. This indicates that there are two different DNA repair systems for double-strand breaks and the system for non-homologous end-joining repair can be involved in all phases of cell cycle, but the system for the homologous one is involved only in S-phase. Therefore, it was thought that variation of sensitivity to radiation exposure depending to the phase of cell cycle might explain the alternation of repair system depending to the phase progressing of cell cycle. It was thus likely that the recovery from radiation injury, which is still a black box might be explained with the double strand breaks of DNA. (M.N.)

  6. Mechanisms of renal cell repair and regeneration after acute renal failure.

    Science.gov (United States)

    Nony, Paul A; Schnellmann, Rick G

    2003-03-01

    In many cases, acute renal failure (ARF) is the result of proximal tubular cell injury and death and can arise in a variety of clinical situations, especially following renal ischemia and drug or toxicant exposure. Although much research has focused on the cellular events leading to ARF, less emphasis has been placed on the mechanisms of renal cell repair and regeneration, although ARF is reversed in over half of those who acquire it. Studies using in vivo and in vitro models have demonstrated the importance of proliferation, migration, and repair of physiological functions of injured renal proximal tubular cells (RPTC) in the reversal of ARF. Growth factors have been shown to produce migration and proliferation of injured RPTC, although the specific mechanisms through which growth factors promote renal regeneration in vivo are unclear. Recently, interactions between integrins and extracellular matrix proteins such as collagen IV were shown to promote the repair of physiological functions in injured RPTC. Specifically, collagen IV synthesis and deposition following cellular injury restored integrin polarity and promoted repair of mitochondrial function and active Na(+) transport. Furthermore, exogenous collagen IV, but not collagen I, fibronectin, or laminin, promoted the repair of physiological functions without stimulating proliferation. These findings suggest the importance of establishing and/or maintaining collagen IV-integrin interactions in the stimulation of repair of physiological functions following sublethal cellular injury. Furthermore, the pathway that stimulates repair is distinct from that of proliferation and migration and may be a viable target for pharmacological intervention.

  7. Caracterização mecânica de polipropileno reciclado para a indústria automotiva Mechanical characterization of recycled polypropylene for automotive industry

    Directory of Open Access Journals (Sweden)

    Beatriz L. Fernandes

    2007-06-01

    Full Text Available A indústria automotiva responde, atualmente, por uma grande parte do mercado de consumo de plásticos, por isso existe um crescente interesse no investimento em processos de reciclagem, inclusive devido à vinculação às atividades relacionadas à proteção ambiental. Dentre as peças automotivas, os pára-choques são relativamente fáceis de serem reciclados devido às suas dimensões e por constituírem, geralmente, de um único material, o polipropileno (PP. Neste trabalho, analisaram-se as propriedades mecânicas de misturas de PP virgem e reciclado, em três porcentagens diferentes, a fim de detectar as alterações das mesmas, relacionando-as à qualidade do produto. Concluiu-se que porcentagens de reciclado acima de 30% causam deterioração das propriedades mecânicas do produto. Este estudo visa a fornecer uma contribuição para o aumento na utilização de plásticos reciclados na indústria automotiva.The automotive industry is now responsible for a large share of plastic consumption, which prompted increasing investments in recycling processes, also due to the need of ambient protection. Among the automotives parts, bumpers are relatively easy to be recycled due to their dimensions and because they are made of a single material, polypropylene (PP. In this work, the mechanical properties of mixtures of virgin and recycled PP, in three different percentages, were analyzed in order to detect alterations and associate them with the product quality. It was concluded that percentages of recycled material above 30% deteriorate the mechanical properties of the product. This study aims to provide a contribution to the increase in the recycled plastic use in the automotive industry.

  8. DREMECELS: A Curated Database for Base Excision and Mismatch Repair Mechanisms Associated Human Malignancies.

    Directory of Open Access Journals (Sweden)

    Ankita Shukla

    Full Text Available DNA repair mechanisms act as a warrior combating various damaging processes that ensue critical malignancies. DREMECELS was designed considering the malignancies with frequent alterations in DNA repair pathways, that is, colorectal and endometrial cancers, associated with Lynch syndrome (also known as HNPCC. Since lynch syndrome carries high risk (~40-60% for both cancers, therefore we decided to cover all three diseases in this portal. Although a large population is presently affected by these malignancies, many resources are available for various cancer types but no database archives information on the genes specifically for only these cancers and disorders. The database contains 156 genes and two repair mechanisms, base excision repair (BER and mismatch repair (MMR. Other parameters include some of the regulatory processes that have roles in these disease progressions due to incompetent repair mechanisms, specifically BER and MMR. However, our unique database mainly provides qualitative and quantitative information on these cancer types along with methylation, drug sensitivity, miRNAs, copy number variation (CNV and somatic mutations data. This database would serve the scientific community by providing integrated information on these disease types, thus sustaining diagnostic and therapeutic processes. This repository would serve as an excellent accompaniment for researchers and biomedical professionals and facilitate in understanding such critical diseases. DREMECELS is publicly available at http://www.bioinfoindia.org/dremecels.

  9. Kinetic theory approach to modeling of cellular repair mechanisms under genome stress.

    Directory of Open Access Journals (Sweden)

    Jinpeng Qi

    Full Text Available Under acute perturbations from outer environment, a normal cell can trigger cellular self-defense mechanism in response to genome stress. To investigate the kinetics of cellular self-repair process at single cell level further, a model of DNA damage generating and repair is proposed under acute Ion Radiation (IR by using mathematical framework of kinetic theory of active particles (KTAP. Firstly, we focus on illustrating the profile of Cellular Repair System (CRS instituted by two sub-populations, each of which is made up of the active particles with different discrete states. Then, we implement the mathematical framework of cellular self-repair mechanism, and illustrate the dynamic processes of Double Strand Breaks (DSBs and Repair Protein (RP generating, DSB-protein complexes (DSBCs synthesizing, and toxins accumulating. Finally, we roughly analyze the capability of cellular self-repair mechanism, cellular activity of transferring DNA damage, and genome stability, especially the different fates of a certain cell before and after the time thresholds of IR perturbations that a cell can tolerate maximally under different IR perturbation circumstances.

  10. Molecular Mechanisms of Ultraviolet Radiation-Induced DNA Damage and Repair

    Directory of Open Access Journals (Sweden)

    Rajesh P. Rastogi

    2010-01-01

    Full Text Available DNA is one of the prime molecules, and its stability is of utmost importance for proper functioning and existence of all living systems. Genotoxic chemicals and radiations exert adverse effects on genome stability. Ultraviolet radiation (UVR (mainly UV-B: 280–315 nm is one of the powerful agents that can alter the normal state of life by inducing a variety of mutagenic and cytotoxic DNA lesions such as cyclobutane-pyrimidine dimers (CPDs, 6-4 photoproducts (6-4PPs, and their Dewar valence isomers as well as DNA strand breaks by interfering the genome integrity. To counteract these lesions, organisms have developed a number of highly conserved repair mechanisms such as photoreactivation, base excision repair (BER, nucleotide excision repair (NER, and mismatch repair (MMR. Additionally, double-strand break repair (by homologous recombination and nonhomologous end joining, SOS response, cell-cycle checkpoints, and programmed cell death (apoptosis are also operative in various organisms with the expense of specific gene products. This review deals with UV-induced alterations in DNA and its maintenance by various repair mechanisms.

  11. Experimental Observation of the Skeletal Adaptive Repair Mechanism and Bionic Topology Optimization Method

    Directory of Open Access Journals (Sweden)

    Kaysar Rahman

    2014-01-01

    Full Text Available Bone adaptive repair theory considers that the external load is the direct source of bone remodeling; bone achieves its maintenance by remodeling some microscopic damages due to external load during the process. This paper firstly observes CT data from the whole self-repairing process in bone defects in rabbit femur. Experimental result shows that during self-repairing process there exists an interaction relationship between spongy bone and enamel bone volume changes of bone defect, that is when volume of spongy bone increases, enamel bone decreases, and when volume of spongy bone decreases, enamel bone increases. Secondly according to this feature a bone remodeling model based on cross-type reaction-diffusion system influenced by mechanical stress is proposed. Finally, this model coupled with finite element method by using the element adding and removing process is used to simulate the self-repairing process and engineering optimization problems by considering the idea of bionic topology optimization.

  12. Thermo-mechanical cracking of a new and laser repair welded die casting die

    Directory of Open Access Journals (Sweden)

    D. Klobčar

    2012-07-01

    Full Text Available The paper presents the analysis of thermo-mechanical fatigue cracking of die casting die during industrial use. An innovative, production friendly approach to monitor the surface crack dimensions was introduced, which is based on measuring defect-fin on the casting part. A new four moulds die casting die was monitored 40 000 cycles in order to complete the production series. The production was stopped three times for laser repair welding of cracks since the defect-fins were not acceptable. The defect-fin heights were measured every 1 000 cycles on the castings before and after repair welding of die surface cracks. The in-service die life can be prolonged with laser repair welding for several times, even thought that in-service die life for a particular repair varies.

  13. Sharpening the ends for repair: mechanisms and regulation of DNA resection

    Institute of Scientific and Technical Information of China (English)

    Sharad C.Paudyal; Zhongsheng You

    2016-01-01

    DNA end resection is a key process in the cellular response to DNA double-strand break damage that is essential for genome maintenance and cell survival.Resection involves selective processing of 5' ends of broken DNA to generate ssDNA overhangs,which in turn control both DNA repair and checkpoint signaling.DNA resection is the first step in homologous recombination-mediated repair and a prerequisite for the activation of the ataxia telangiectasia mutated and Rad3-related (ATR)-dependent checkpoint that coordinates repair with cell cycle progression and other cellular processes.Resection occurs in a cell cycle-dependent manner and is regulated by multiple factors to ensure an optimal amount of ssDNA required for proper repair and genome stability.Here,we review the latest findings on the molecular mechanisms and regulation of the DNA end resection process and their implications for cancer formation and treatment.

  14. Automotive vehicle sensors

    Energy Technology Data Exchange (ETDEWEB)

    Sheen, S.H.; Raptis, A.C.; Moscynski, M.J.

    1995-09-01

    This report is an introduction to the field of automotive vehicle sensors. It contains a prototype data base for companies working in automotive vehicle sensors, as well as a prototype data base for automotive vehicle sensors. A market analysis is also included.

  15. DNA damage by reactive species: Mechanisms, mutation and repair.

    Science.gov (United States)

    Jena, N R

    2012-07-01

    DNA is continuously attacked by reactive species that can affect its structure and function severely. Structural modifications to DNA mainly arise from modifications in its bases that primarily occur due to their exposure to different reactive species. Apart from this, DNA strand break, inter- and intra-strand crosslinks and DNA-protein crosslinks can also affect the structure of DNA significantly. These structural modifications are involved in mutation, cancer and many other diseases. As it has the least oxidation potential among all the DNA bases, guanine is frequently attacked by reactive species, producing a plethora of lethal lesions. Fortunately, living cells are evolved with intelligent enzymes that continuously protect DNA from such damages. This review provides an overview of different guanine lesions formed due to reactions of guanine with different reactive species. Involvement of these lesions in inter- and intra-strand crosslinks, DNA-protein crosslinks and mutagenesis are discussed. How certain enzymes recognize and repair different guanine lesions in DNA are also presented.

  16. DNA damage by reactive species: Mechanisms, mutation and repair

    Indian Academy of Sciences (India)

    N R Jena

    2012-07-01

    DNA is continuously attacked by reactive species that can affect its structure and function severely. Structural modifications to DNA mainly arise from modifications in its bases that primarily occur due to their exposure to different reactive species. Apart from this, DNA strand break, inter- and intra-strand crosslinks and DNA–protein crosslinks can also affect the structure of DNA significantly. These structural modifications are involved in mutation, cancer and many other diseases. As it has the least oxidation potential among all the DNA bases, guanine is frequently attacked by reactive species, producing a plethora of lethal lesions. Fortunately, living cells are evolved with intelligent enzymes that continuously protect DNA from such damages. This review provides an overview of different guanine lesions formed due to reactions of guanine with different reactive species. Involvement of these lesions in inter- and intra-strand crosslinks, DNA–protein crosslinks and mutagenesis are discussed. How certain enzymes recognize and repair different guanine lesions in DNA are also presented.

  17. Cetuximab Induces Eme1-Mediated DNA Repair: a Novel Mechanism for Cetuximab Resistance

    Directory of Open Access Journals (Sweden)

    Agnieszka Weinandy

    2014-03-01

    Full Text Available Overexpression of the epidermal growth factor receptor (EGFR is observed in a large number of neoplasms. The monoclonal antibody cetuximab/Erbitux is frequently applied to treat EGFR-expressing tumors. However, the application of cetuximab alone or in combination with radio- and/or chemotherapy often yields only little benefit for patients. In the present study, we describe a mechanism that explains resistance of both tumor cell lines and cultured primary human glioma cells to cetuximab. Treatment of these cells with cetuximab promoted DNA synthesis in the absence of increased proliferation, suggesting that DNA repair pathways were activated. Indeed, we observed that cetuximab promoted the activation of the DNA damage response pathway and prevented the degradation of essential meiotic endonuclease 1 homolog 1 (Eme1, a heterodimeric endonuclease involved in DNA repair. The increased levels of Eme1 were necessary for enhanced DNA repair, and the knockdown of Eme1 was sufficient to prevent efficient DNA repair in response to ultraviolet-C light or megavoltage irradiation. These treatments reduced the survival of tumor cells, an effect that was reversed by cetuximab application. Again, this protection was dependent on Eme1. Taken together, these results suggest that cetuximab initiates pathways that result in the stabilization of Eme1, thereby resulting in enhanced DNA repair. Accordingly, cetuximab enhances DNA repair, reducing the effectiveness of DNA-damaging therapies. This aspect should be considered when using cetuximab as an antitumor agent and suggests that Eme1 is a negative predictive marker.

  18. Long-term anisotropic mechanical response of surgical meshes used to repair abdominal wall defects.

    Science.gov (United States)

    Hernández-Gascón, B; Peña, E; Pascual, G; Rodríguez, M; Bellón, J M; Calvo, B

    2012-01-01

    Routine hernia repair surgery involves the implant of synthetic mesh. However, this type of procedure may give rise to pain and bowel incarceration and strangulation, causing considerable patient disability. The purpose of this study was to compare the long-term behaviour of three commercial meshes used to repair the partially herniated abdomen in New Zealand White rabbits: the heavyweight (HW) mesh, Surgipro(®) and lightweight (LW) mesh, Optilene(®), both made of polypropylene (PP), and a mediumweight (MW) mesh, Infinit(®), made of polytetrafluoroethylene (PTFE). The implanted meshes were mechanical and histological assessed at 14, 90 and 180 days post-implant. This behaviour was compared to the anisotropic mechanical behaviour of the unrepaired abdominal wall in control non-operated rabbits. Both uniaxial mechanical tests conducted in craneo-caudal and perpendicular directions and histological findings revealed substantial collagen growth over the repaired hernial defects causing stiffness in the repair zone, and thus a change in the original properties of the meshes. The mechanical behaviour of the healthy tissue in the craneo-caudal direction was not reproduced by any of the implanted meshes after 14 days or 90 days of implant, whereas in the perpendicular direction, SUR and OPT achieved similar behaviour. From a mechanical standpoint, the anisotropic PP-lightweight meshes may be considered a good choice in the long run, which correlates with the structure of the regenerated tissue. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Mechanical ventilation injury and repair in extremely and very preterm lungs.

    Directory of Open Access Journals (Sweden)

    Nadine Brew

    Full Text Available BACKGROUND: Extremely preterm infants often receive mechanical ventilation (MV, which can contribute to bronchopulmonary dysplasia (BPD. However, the effects of MV alone on the extremely preterm lung and the lung's capacity for repair are poorly understood. AIM: To characterise lung injury induced by MV alone, and mechanisms of injury and repair, in extremely preterm lungs and to compare them with very preterm lungs. METHODS: Extremely preterm lambs (0.75 of term were transiently exposed by hysterotomy and underwent 2 h of injurious MV. Lungs were collected 24 h and at 15 d after MV. Immunohistochemistry and morphometry were used to characterise injury and repair processes. qRT-PCR was performed on extremely and very preterm (0.85 of term lungs 24 h after MV to assess molecular injury and repair responses. RESULTS: 24 h after MV at 0.75 of term, lung parenchyma and bronchioles were severely injured; tissue space and myofibroblast density were increased, collagen and elastin fibres were deformed and secondary crest density was reduced. Bronchioles contained debris and their epithelium was injured and thickened. 24 h after MV at 0.75 and 0.85 of term, mRNA expression of potential mediators of lung repair were significantly increased. By 15 days after MV, most lung injury had resolved without treatment. CONCLUSIONS: Extremely immature lungs, particularly bronchioles, are severely injured by 2 h of MV. In the absence of continued ventilation these injured lungs are capable of repair. At 24 h after MV, genes associated with injurious MV are unaltered, while potential repair genes are activated in both extremely and very preterm lungs.

  20. DNA Repair and Photoprotection: Mechanisms of Overcoming Environmental Ultraviolet Radiation Exposure in Halophilic Archaea

    Directory of Open Access Journals (Sweden)

    Daniel L. Jones

    2017-09-01

    Full Text Available Halophilic archaea push the limits of life at several extremes. In particular, they are noted for their biochemical strategies in dealing with osmotic stress, low water activity and cycles of desiccation in their hypersaline environments. Another feature common to their habitats is intense ultraviolet (UV radiation, which is a challenge that microorganisms must overcome. The consequences of high UV exposure include DNA lesions arising directly from bond rearrangement of adjacent bipyrimidines, or indirectly from oxidative damage, which may ultimately result in mutation and cell death. As such, these microorganisms have evolved a number of strategies to navigate the threat of DNA damage, which we differentiate into two categories: DNA repair and photoprotection. Photoprotection encompasses damage avoidance strategies that serve as a “first line of defense,” and in halophilic archaea include pigmentation by carotenoids, mechanisms of oxidative damage avoidance, polyploidy, and genomic signatures that make DNA less susceptible to photodamage. Photolesions that do arise are addressed by a number of DNA repair mechanisms that halophilic archaea efficiently utilize, which include photoreactivation, nucleotide excision repair, base excision repair, and homologous recombination. This review seeks to place DNA damage, repair, and photoprotection in the context of halophilic archaea and the solar radiation of their hypersaline environments. We also provide new insight into the breadth of strategies and how they may work together to produce remarkable UV-resistance for these microorganisms.

  1. Cellular mechanisms of neurovascular damage and repair after stroke.

    Science.gov (United States)

    Arai, Ken; Lok, Josephine; Guo, Shuzhen; Hayakawa, Kazuhide; Xing, Changhong; Lo, Eng H

    2011-09-01

    The biological processes underlying stroke are complex, and patients have a narrow repertoire of therapeutic opportunities. After the National Institutes of Health (NIH) convened the Stroke Progress Review Group in 2001, stroke research shifted from having a purely neurocentric focus to adopting a more integrated view wherein dynamic interactions between all cell types contribute to function and dysfunction in the brain. This so-called "neurovascular unit" provides a conceptual framework that emphasizes cell-cell interactions between neuronal, glial, and vascular elements. Under normal conditions, signaling within the neurovascular unit helps maintain homeostasis. After stroke, cell-cell signaling is disturbed, leading to pathophysiology. More recently, emerging data now suggest that these cell-cell signaling mechanisms may also mediate parallel processes of neurovascular remodeling during stroke recovery. Because plasticity is a signature feature of the young and developing brain, these concepts may have special relevance to how the pediatric brain responds after stroke.

  2. European Automotive Congress

    CERN Document Server

    Clenci, Adrian

    2016-01-01

    The volume includes selected and reviewed papers from the European Automotive Congress held in Bucharest, Romania, in November 2015. Authors are experts from research, industry and universities coming from 14 countries worldwide. The papers are covering the latest developments in fuel economy and environment, automotive safety and comfort, automotive reliability and maintenance, new materials and technologies, traffic and road transport systems, advanced engineering methods and tools, as well as advanced powertrains and hybrid and electric drives.

  3. Auto Mechanics. Performance Objectives. Basic Course.

    Science.gov (United States)

    Carter, Thomas G., Sr.

    Several intermediate performance objectives and corresponding criterion measures are listed for each of 14 terminal objectives for a basic automotive mechanics course. The materials were developed for a two-semester course (2 hours daily) designed to provide training in the basic fundamentals in diagnosis and repair including cooling system and…

  4. UV-induced dark repair mechanisms in bacteria associated with drinking water.

    Science.gov (United States)

    Jungfer, Christina; Schwartz, Thomas; Obst, Ursula

    2007-01-01

    Caulobacter crescentus and Aquabacterium commune, both isolated from drinking water, as well as environmental isolates of Pseudomonas aeruginosa and Enterococcus faecium were treated with different UV fluences to study their capacity to restore induced DNA damages. Here, the induction of a key mechanism of bacterial dark repair, the so-called recA system, was analysed. With newly designed probes, the specific recA mRNA was detected by Northern blot. Additionally, the RecA protein was measured by the Western blot technique using a specific antibody. In drinking water bacteria as well as in opportunistic microorganisms, a specific induction of dark repair mechanisms was found even at UV fluences higher than 400J/m(2), the German standard for UV disinfection. This induction depended on the incubation time after UV treatment. Nevertheless, the UV-induced recA expressions were found to differ in the bacteria under investigation.

  5. The effects of multiple repairs on Inconel 718 weld mechanical properties

    Science.gov (United States)

    Russell, C. K.; Nunes, A. C., Jr.; Moore, D.

    1991-01-01

    Inconel 718 weldments were repaired 3, 6, 9, and 13 times using the gas tungsten arc welding process. The welded panels were machined into mechanical test specimens, postweld heat treated, and nondestructively tested. Tensile properties and high cycle fatigue life were evaluated and the results compared to unrepaired weld properties. Mechanical property data were analyzed using the statistical methods of difference in means for tensile properties and difference in log means and Weibull analysis for high cycle fatigue properties. Statistical analysis performed on the data did not show a significant decrease in tensile or high cycle fatigue properties due to the repeated repairs. Some degradation was observed in all properties, however, it was minimal.

  6. The cellular and molecular mechanisms of tissue repair and regeneration as revealed by studies in Xenopus

    Science.gov (United States)

    Li, Jingjing; Zhang, Siwei

    2016-01-01

    Abstract Survival of any living organism critically depends on its ability to repair and regenerate damaged tissues and/or organs during its lifetime following injury, disease, or aging. Various animal models from invertebrates to vertebrates have been used to investigate the molecular and cellular mechanisms of wound healing and tissue regeneration. It is hoped that such studies will form the framework for identifying novel clinical treatments that will improve the healing and regenerative capacity of humans. Amongst these models, Xenopus stands out as a particularly versatile and powerful system. This review summarizes recent findings using this model, which have provided fundamental knowledge of the mechanisms responsible for efficient and perfect tissue repair and regeneration.

  7. Understanding the Molecular Mechanism(s) of Formaldehyde-induced DNA-protein Crosslink Repair

    Science.gov (United States)

    Although formaldehyde has been shown to induce many kinds of DNA damage both in in vitro and in vivo assay systems, initial DNA-protein crosslink (DPC) formation might play a major role in FA-induced mutagenesis and carcinogenesis. Several DNA repair pathways, such as base excisi...

  8. Physicochemical Mechanism of Light-Driven DNA Repair by (6-4) Photolyases

    Science.gov (United States)

    Faraji, Shirin; Dreuw, Andreas

    2014-04-01

    DNA photolyases are light-activated enzymes that repair DNA damage induced by ultraviolet (UV) radiation. UV radiation causes two of the most abundant mutagenic and cytotoxic DNA lesions: cyclobutane pyrimidine dimers and 6-4 photolesions. Photolyases selectively bind to DNA and initiate the splitting of mutagenic pyrimidine dimers via photoinduced electron transfer from a flavin adenine dinucleotide anion (FADH-) to the lesion triggering its repair. This review discusses the consecutive steps of the repair process, from both experimental and theoretical points of view. It covers the following issues: the process of how photolyases accommodate the lesion into their binding pockets, excitation energy transfer between two involved catalytic cofactors, photoinduced electron transfer to the lesion, the splitting of the pyrimidine dimer radical anion, and the fate of the unstable radical species created after the splitting of the thymine dimer. In particular, mechanisms of the splitting and restoration of the original bases are described in detail, and the most probable repair pathways are outlined.

  9. Mechanical and toughness properties of robotic-FSW repair welds in 6061-T6 aluminium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Brinckmann, S.; Strombeck, A. v.; Schilling, C.; Santos, J.F. dos; Kocak, M. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Materialforschung; Lohwasser, D. [DaimlerChrysler Aerospace Airbus GmbH, Bremen (Germany)

    2000-07-01

    Panel or structures welded in fixed installations might require local repair of eventual process induced defects. Ideally such repair operations should take place outside the production line to avoid interruption of the manufacturing flow. Robotic FSW systems offer the required flexibility to perform such repairs. The main objective of this work was to conduct a preliminary investigation on the microstructural, mechanical and toughness properties of robotic friction stir repair welds. To achieve this objective defective welds have been purposely produced and subsequently repaired. Specimens for microstructural analysis, mechanical and fracture toughness testing have been obtained from repaired and defect-free welds as well as from the base plate for comparison purposes. The mechanical properties have been established using standard tests, i.e. hardness, bending and tensile. Toughness properties of the joints have been determined using small (compact tension - CT) and large (M(T)) scale specimens. Fatigue pre-cracks were positioned in the nugget and HAZ. Crack resistance curves (R-Curves) were determined using the potential drop technique. The obtained results indicated that the additional thermal cycle and deformation process imposed by the repair weld did not adversely affect the mechanical and toughness properties of the nugget area. Both defect-free and repair welds showed higher toughness than the base material. Pre-cracks positioned in the nugget region were deviated into the lower strength TMAZ after initiation and ductile crack growth within the nugget area due to strength undermatch. Later propagation remained within the TMAZ. (orig.) [German] Das Schweissen von Elementen oder Strukturen kann eine lokale Reparatur erfordern, wenn durch den Fuegeprozess ausgeloeste Fehler auftreten. Vorteilhafterweise sollten die Reparaturen ausserhalb der Fertigungslinie erfolgen, um den Produktionsablauf nicht zu stoeren. Robotergestuetzte FSW-Systeme bieten die benoetigte

  10. Quantum mechanics/molecular mechanics study on the oxygen binding and substrate hydroxylation step in AlkB repair enzymes.

    Science.gov (United States)

    Quesne, Matthew G; Latifi, Reza; Gonzalez-Ovalle, Luis E; Kumar, Devesh; de Visser, Sam P

    2014-01-07

    AlkB repair enzymes are important nonheme iron enzymes that catalyse the demethylation of alkylated DNA bases in humans, which is a vital reaction in the body that heals externally damaged DNA bases. Its mechanism is currently controversial and in order to resolve the catalytic mechanism of these enzymes, a quantum mechanics/molecular mechanics (QM/MM) study was performed on the demethylation of the N(1) -methyladenine fragment by AlkB repair enzymes. Firstly, the initial modelling identified the oxygen binding site of the enzyme. Secondly, the oxygen activation mechanism was investigated and a novel pathway was found, whereby the catalytically active iron(IV)-oxo intermediate in the catalytic cycle undergoes an initial isomerisation assisted by an Arg residue in the substrate binding pocket, which then brings the oxo group in close contact with the methyl group of the alkylated DNA base. This enables a subsequent rate-determining hydrogen-atom abstraction on competitive σ- and π-pathways on a quintet spin-state surface. These findings give evidence of different locations of the oxygen and substrate binding channels in the enzyme and the origin of the separation of the oxygen-bound intermediates in the catalytic cycle from substrate. Our studies are compared with small model complexes and the effect of protein and environment on the kinetics and mechanism is explained.

  11. [Inter-rater agreement on self-reported exposure to ergonomic risk factors for the upper extremities among mechanic assemblers in an automotive industry].

    Science.gov (United States)

    d'Errico, Angelo; Fontana, Dario; Merogno, Angela

    2016-01-01

    to assess reproducibility of self-reported exposure to ergonomic hazards for the upper limbs, measured through a questionnaire based on a diffused checklist for the assessment of ergonomic risk (OCRA) in a sample of mechanical assemblers of an automotive industry. cross-sectional study; reproducibility was assessed as interrater agreement of a composite index of ergonomic risk, estimated through the intraclass correlation coefficient (ICC). 58 mechanical assemblers, working in 29 twin areas, characterised by same work stations and tasks. composite index of ergonomic risk for the upper limbs. reproducibility of the ergonomic index was high in the overall sample (ICC: 0.81) and it was higher for the twin areas employing same-gender workers (ICC: 0.96), compared to those with workers of the opposite gender (ICC: 0.66). these results indicate that a questionnaire measuring with a great detail the exposure to the main ergonomic risk factors for the upper limbs, as the one based on the OCRA checklist used for this study, would allow to obtain a highly reproducible ergonomic index. If its validity against the corresponding observational checklist will be found elevated by future studies, this questionnaire may represent a useful tool for a preliminary assessment of workers' exposure to ergonomic hazards for the upper limbs.

  12. DNA repair pathways underlie a common genetic mechanism modulating onset in polyglutamine diseases

    Science.gov (United States)

    Bettencourt, Conceição; Hensman‐Moss, Davina; Flower, Michael; Wiethoff, Sarah; Brice, Alexis; Goizet, Cyril; Stevanin, Giovanni; Koutsis, Georgios; Karadima, Georgia; Panas, Marios; Yescas‐Gómez, Petra; García‐Velázquez, Lizbeth Esmeralda; Alonso‐Vilatela, María Elisa; Lima, Manuela; Raposo, Mafalda; Traynor, Bryan; Sweeney, Mary; Wood, Nicholas; Giunti, Paola; Durr, Alexandra; Holmans, Peter; Houlden, Henry; Tabrizi, Sarah J.

    2016-01-01

    Objective The polyglutamine diseases, including Huntington's disease (HD) and multiple spinocerebellar ataxias (SCAs), are among the commonest hereditary neurodegenerative diseases. They are caused by expanded CAG tracts, encoding glutamine, in different genes. Longer CAG repeat tracts are associated with earlier ages at onset, but this does not account for all of the difference, and the existence of additional genetic modifying factors has been suggested in these diseases. A recent genome‐wide association study (GWAS) in HD found association between age at onset and genetic variants in DNA repair pathways, and we therefore tested whether the modifying effects of variants in DNA repair genes have wider effects in the polyglutamine diseases. Methods We assembled an independent cohort of 1,462 subjects with HD and polyglutamine SCAs, and genotyped single‐nucleotide polymorphisms (SNPs) selected from the most significant hits in the HD study. Results In the analysis of DNA repair genes as a group, we found the most significant association with age at onset when grouping all polyglutamine diseases (HD+SCAs; p = 1.43 × 10–5). In individual SNP analysis, we found significant associations for rs3512 in FAN1 with HD+SCAs (p = 1.52 × 10–5) and all SCAs (p = 2.22 × 10–4) and rs1805323 in PMS2 with HD+SCAs (p = 3.14 × 10–5), all in the same direction as in the HD GWAS. Interpretation We show that DNA repair genes significantly modify age at onset in HD and SCAs, suggesting a common pathogenic mechanism, which could operate through the observed somatic expansion of repeats that can be modulated by genetic manipulation of DNA repair in disease models. This offers novel therapeutic opportunities in multiple diseases. Ann Neurol 2016;79:983–990 PMID:27044000

  13. Alternative mechanisms of telomere lengthening: Permissive mutations, DNA repair proteins and tumorigenic progression

    Energy Technology Data Exchange (ETDEWEB)

    Gocha, April Renee Sandy; Harris, Julia [Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University College of Medicine, Columbus, OH 43210 (United States); Groden, Joanna, E-mail: joanna.groden@osumc.edu [Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University College of Medicine, Columbus, OH 43210 (United States)

    2013-03-15

    Highlights: ► Neoplastic cells maintain telomeres by telomerase or ALT. ► Genetic mutations in p53, ATRX, DAXX or H3F3A may activate ALT. ► Many DNA repair proteins are involved in ALT. ► Tumor progression is favored by telomerase expression. - Abstract: Telomeres protect chromosome termini to maintain genomic stability and regulate cellular lifespan. Maintenance of telomere length is required for neoplastic cells after the acquisition of mutations that deregulate cell cycle control and increase cellular proliferation, and can occur through expression of the enzyme telomerase or in a telomerase-independent manner termed alternative lengthening of telomeres (ALT). The precise mechanisms that govern the activation of ALT or telomerase in tumor cells are unknown, although cellular origin may favor one or the other mechanisms. ALT pathways are incompletely understood to date; however, recent publications have increasingly broadened our understanding of how ALT is activated, how it proceeds, and how it influences tumor growth. Specific mutational events influence ALT activation, as mutations in genes that suppress recombination and/or alterations in the regulation of telomerase expression are associated with ALT. Once engaged, ALT uses DNA repair proteins to maintain telomeres in the absence of telomerase; experiments that manipulate the expression of specific proteins in cells using ALT are illuminating some of its mechanisms. Furthermore, ALT may influence tumor growth, as experimental and clinical data suggest that telomerase expression may favor tumor progression. This review summarizes recent findings in mammalian cells and models, as well as clinical data, that identify the genetic mutations permissive to ALT, the DNA repair proteins involved in ALT mechanisms and the importance of telomere maintenance mechanisms for tumor progression. A comprehensive understanding of the mechanisms that permit tumor cell immortalization will be important for identifying

  14. Mechanical Complication with Broviac Repair Kit in a 4-Year-Old Boy with MEN 2a

    Directory of Open Access Journals (Sweden)

    Sergio B. Sesia

    2009-01-01

    Full Text Available Background. Mechanical complications in the use of indwelling central venous catheters (CVCs such as the Broviac catheter (BC include kinking, occlusion, dislocation or leaking. We report on a mechanical complication after using a repair kit for the BC. Method. A 4-year old boy, suffering from multiple endocrine neoplasia type 2a (MEN 2a, intestinal aganglionosis (Hirschsprung's disease, and short bowel syndrome, required a BC for home parenteral nutrition. Result. Due to recurrent leakage of the BC, 5 subsequent repairs were necessary within seven months. During one repair a metallic tube belonging to the repair kit was found to have migrated proximally to the skin entrance level within the BC and requiring surgical removal. Conclusion. To our knowledge, this is the first report focusing on such a serious complication using a BC and its repair kit. The proximal migration of this metallic tube constitutes a distinct theoretical risk of endothoracic foreign body embolization.

  15. Process-induced extracellular matrix alterations affect the mechanisms of soft tissue repair and regeneration

    Directory of Open Access Journals (Sweden)

    Wendell Q Sun

    2013-09-01

    Full Text Available Extracellular matrices derived from animal tissues for human tissue repairs are processed by various methods of physical, chemical, or enzymatic decellularization, viral inactivation, and terminal sterilization. The mechanisms of action in tissue repair vary among bioscaffolds and are suggested to be associated with process-induced extracellular matrix modifications. We compared three non-cross-linked, commercially available extracellular matrix scaffolds (Strattice, Veritas, and XenMatrix, and correlated extracellular matrix alterations to in vivo biological responses upon implantation in non-human primates. Structural evaluation showed significant differences in retaining native tissue extracellular matrix histology and ultrastructural features among bioscaffolds. Tissue processing may cause both the condensation of collagen fibers and fragmentation or separation of collagen bundles. Calorimetric analysis showed significant differences in the stability of bioscaffolds. The intrinsic denaturation temperature was measured to be 51°C, 38°C, and 44°C for Strattice, Veritas, and XenMatrix, respectively, demonstrating more extracellular matrix modifications in the Veritas and XenMatrix scaffolds. Consequently, the susceptibility to collagenase degradation was increased in Veritas and XenMatrix when compared to their respective source tissues. Using a non-human primate model, three bioscaffolds were found to elicit different biological responses, have distinct mechanisms of action, and yield various outcomes of tissue repair. Strattice permitted cell repopulation and was remodeled over 6 months. Veritas was unstable at body temperature, resulting in rapid absorption with moderate inflammation. XenMatrix caused severe inflammation and sustained immune reactions. This study demonstrates that extracellular matrix alterations significantly affect biological responses in soft tissue repair and regeneration. The data offer useful insights into the

  16. The structural and mechanical properties of the Achilles tendon 2 years after surgical repair.

    Science.gov (United States)

    Geremia, Jeam Marcel; Bobbert, Maarten Frank; Casa Nova, Mayra; Ott, Rafael Duvelius; Lemos, Fernando de Aguiar; Lupion, Raquel de Oliveira; Frasson, Viviane Bortoluzzi; Vaz, Marco Aurélio

    2015-06-01

    Acute ruptures of the Achilles tendon affect the tendon's structural and mechanical properties. The long-term effects of surgical repair on these properties remain unclear. To evaluate effects of early mobilization versus traditional immobilization rehabilitation programs 2 years after surgical Achilles tendon repair, by comparing force-elongation and stress-strain relationships of the injured tendon to those of the uninjured tendon. A group of males with previous Achilles tendon rupture (n=18) and a group of healthy male controls (n=9) participated. Achilles tendon rupture group consisted of patients that had received early mobilization (n=9) and patients that had received traditional immobilization with a plaster cast (n=9). Comparisons of tendon structural and mechanical properties were made between Achilles tendon rupture and healthy control groups, and between the uninjured and injured sides of the two rehabilitation groups in Achilles tendon rupture group. Ultrasound was used to determine bilaterally tendon cross-sectional area, tendon resting length, and tendon elongation as a function of torque during maximal voluntary plantar flexion. From these data, Achilles tendon force-elongation and stress-strain relationships were determined. The Achilles tendon rupture group uninjured side was not different from healthy control group. Structural and mechanical parameters of the injured side were not different between the Achilles tendon rupture early mobilization and the immobilization groups. Compared to the uninjured side, the injured side showed a reduction in stress at maximal voluntary force, in Young's modulus and in stiffness. Two years post-surgical repair, the Achilles tendon mechanical properties had not returned to the uninjured contralateral tendon values. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Repair mechanisms inducible to the DNA in I.M.M.S. biological systems; Mecanismos de reparacion inducible del ADN en sistemas biologicos I.M.M.S

    Energy Technology Data Exchange (ETDEWEB)

    Guzman, J.; Arceo, C.; Cortinas, C.; Rosa, M.E. De la; Olvera, O.; Cruces, M.; Pimentel, E

    1990-03-15

    Given the characteristics of the MMS and the relative antecedents to the repair mechanisms in eucariontes are sought to determine the effect of the MMS on the genetic material and their repair in Drosophila melanogaster. (Author)

  18. Sp1 facilitates DNA double-strand break repair through a nontranscriptional mechanism.

    Science.gov (United States)

    Beishline, Kate; Kelly, Crystal M; Olofsson, Beatrix A; Koduri, Sravanthi; Emrich, Jacqueline; Greenberg, Roger A; Azizkhan-Clifford, Jane

    2012-09-01

    Sp1 is a ubiquitously expressed transcription factor that is phosphorylated by ataxia telangiectasia mutated kinase (ATM) in response to ionizing radiation and H(2)O(2). Here, we show by indirect immunofluorescence that Sp1 phosphorylated on serine 101 (pSp1) localizes to ionizing radiation-induced foci with phosphorylated histone variant γH2Ax and members of the MRN (Mre11, Rad50, and Nbs1) complex. More precise analysis of occupancy of DNA double-strand breaks (DSBs) by chromatin immunoprecipitation (ChIP) shows that Sp1, like Nbs1, resides within 200 bp of DSBs. Using laser microirradiation of cells, we demonstrate that pSp1 is present at DNA DSBs by 7.5 min after induction of damage and remains at the break site for at least 8 h. Depletion of Sp1 inhibits repair of site-specific DNA breaks, and the N-terminal 182-amino-acid peptide, which contains targets of ATM kinase but lacks the zinc finger DNA binding domain, is phosphorylated, localizes to DSBs, and rescues the repair defect resulting from Sp1 depletion. Together, these data demonstrate that Sp1 is rapidly recruited to the region immediately adjacent to sites of DNA DSBs and is required for DSB repair, through a mechanism independent of its sequence-directed transcriptional effects.

  19. The mechanism of nucleotide excision repair-mediated UV-induced mutagenesis in nonproliferating cells.

    Science.gov (United States)

    Kozmin, Stanislav G; Jinks-Robertson, Sue

    2013-03-01

    Following the irradiation of nondividing yeast cells with ultraviolet (UV) light, most induced mutations are inherited by both daughter cells, indicating that complementary changes are introduced into both strands of duplex DNA prior to replication. Early analyses demonstrated that such two-strand mutations depend on functional nucleotide excision repair (NER), but the molecular mechanism of this unique type of mutagenesis has not been further explored. In the experiments reported here, an ade2 adeX colony-color system was used to examine the genetic control of UV-induced mutagenesis in nondividing cultures of Saccharomyces cerevisiae. We confirmed a strong suppression of two-strand mutagenesis in NER-deficient backgrounds and demonstrated that neither mismatch repair nor interstrand crosslink repair affects the production of these mutations. By contrast, proteins involved in the error-prone bypass of DNA damage (Rev3, Rev1, PCNA, Rad18, Pol32, and Rad5) and in the early steps of the DNA-damage checkpoint response (Rad17, Mec3, Ddc1, Mec1, and Rad9) were required for the production of two-strand mutations. There was no involvement, however, for the Pol η translesion synthesis DNA polymerase, the Mms2-Ubc13 postreplication repair complex, downstream DNA-damage checkpoint factors (Rad53, Chk1, and Dun1), or the Exo1 exonuclease. Our data support models in which UV-induced mutagenesis in nondividing cells occurs during the Pol ζ-dependent filling of lesion-containing, NER-generated gaps. The requirement for specific DNA-damage checkpoint proteins suggests roles in recruiting and/or activating factors required to fill such gaps.

  20. An evaluation of short-term exposures of brake mechanics to asbestos during automotive and truck brake cleaning and machining activities.

    Science.gov (United States)

    Richter, Richard O; Finley, Brent L; Paustenbach, Dennis J; Williams, Pamela R D; Sheehan, Patrick J

    2009-07-01

    Historically, the greatest contributions to airborne asbestos concentrations during brake repair work were likely due to specific, short-duration, dust-generating activities. In this paper, the available short-term asbestos air sampling data for mechanics collected during the cleaning and machining of vehicle brakes are evaluated to determine their impact on both short-term and daily exposures. The high degree of variability and lack of transparency for most of the short-term samples limit their use in reconstructing past asbestos exposures for brake mechanics. However, the data are useful in evaluating how reducing short-term, dust-generating activities reduced long-term exposures, especially for auto brake mechanics. Using the short-term dose data for grinding brake linings from these same studies, in combination with existing time-weighted average (TWA) data collected in decades after grinding was commonplace in rebuilding brake shoes, an average 8-h TWA of approximately 0.10 f/cc was estimated for auto brake mechanics that performed arc grinding of linings during automobile brake repair (in the 1960s or earlier). In the 1970s and early 1980s, a decline in machining activities led to a decrease in the 8-h TWA to approximately 0.063 f/cc. Improved cleaning methods in the late 1980s further reduced the 8-h TWA for most brake mechanics to about 0.0021 f/cc. It is noteworthy that when compared with the original OSHA excursion level, only 15 of the more than 300 short-term concentrations for brake mechanics measured during the 1970s and 1980s possibly exceeded the standard. Considering exposure duration, none of the short-term exposures were above the current OSHA excursion level.

  1. National Automotive Center - NAC

    Data.gov (United States)

    Federal Laboratory Consortium — Encouraged by the advantages of collaboration, the U.S. Army Tank Automotive Research, Development and Engineering Center (TARDEC) worked with the Secretary of the...

  2. Abnormal Base Excision Repair at Trinucleotide Repeats Associated with Diseases: A Tissue-Selective Mechanism

    Directory of Open Access Journals (Sweden)

    Agathi-Vasiliki Goula

    2013-07-01

    Full Text Available More than fifteen genetic diseases, including Huntington’s disease, myotonic dystrophy 1, fragile X syndrome and Friedreich ataxia, are caused by the aberrant expansion of a trinucleotide repeat. The mutation is unstable and further expands in specific cells or tissues with time, which can accelerate disease progression. DNA damage and base excision repair (BER are involved in repeat instability and might contribute to the tissue selectivity of the process. In this review, we will discuss the mechanisms of trinucleotide repeat instability, focusing more specifically on the role of BER.

  3. [Mechanisms of reparative action of a new repair and protect toothpaste].

    Science.gov (United States)

    Elovikova, T M; Ermishina, E Yu; Mikheikina, N I

    The aim of the study was to assess clinical efficacy of Sensodyne repair and protect toothpaste as well as mechanics of its reparative action. Forty-eight patients (29 females and 19 males) were included in the study. The participants brushed twice daily with Sensodyne toothpaste. In 24 patients in addition to clinical examination fluoride, calcium and pH were measured in oral fluid. The study showed OHIS reduction by 40.24% and eradication of tooth hypersensitivity even after single use of the toothpaste in 90% of patients because of sodium monofluorophosphate action.

  4. Effect of repetitive loading on the mechanical properties of synthetic hernia repair materials.

    Science.gov (United States)

    Eliason, Braden J; Frisella, Margaret M; Matthews, Brent D; Deeken, Corey R

    2011-09-01

    Hernia repair materials undergo repeated loading while in the body, and the impact on mechanical properties is unknown. It was hypothesized that exposure to repetitive loading would lead to decreased tensile strength and increased strain, and that these differences would become more pronounced with greater loading and unloading sequences. Polypropylene, expanded polytetrafluoroethylene, composite barrier, and partially absorbable meshes were evaluated. Twenty specimens (7.5 × 7.5 cm) were prepared from each material. Five specimens were subjected to ball burst testing to determine baseline biomechanical properties. Cycles of 10, 100, and 1,000 loading sequences were also performed (n = 5 each). BardMesh (CR Bard/Davol), Dualmesh (WL Gore), and Prolene (Ethicon) exhibited significantly reduced tensile strength; BardMesh, Proceed (Ethicon), Prolene, ProLite (Atrium Medical), ProLite Ultra (Atrium Medical), and Ultrapro (Ethicon) exhibited significantly increased strain after exposure to 1,000 cycles compared with their baseline properties. BardMesh and Prolene demonstrated both reduced tensile strength and increased strain values after 1,000 cycles, suggesting that repetitive loading has the greatest effects on these materials. In addition, BardMesh and Prolene exhibited progressively worsening effects as the number of cycles was increased. Deterioration of the tensile strength of the mesh or an increase in the ability of the mesh material to stretch (ie, increased strain values) could potentially lead to hernia recurrence or a poor functional result. However, the results of this study should not be interpreted to mean that hernia repair materials will fail in the body after only 10, 100, or 1,000 cycles. The conditions used in this study were more extreme than most physiologic scenarios and were intended as a pilot investigation into how the mechanical properties of hernia repair materials are affected by in vitro cyclic testing. Copyright © 2011 American College

  5. Occupational skin diseases in automotive industry workers.

    Science.gov (United States)

    Yakut, Yunus; Uçmak, Derya; Akkurt, Zeynep Meltem; Akdeniz, Sedat; Palanci, Yilmaz; Sula, Bilal

    2014-03-01

    Studies on occupational skin diseases in workers of the automotive industry are few. To investigate the prevalence of occupational skin diseases in workers of the automotive industry. Between September and December 2011, a total of 405 workers from the automotive repair industry in Diyarbakır were interviewed. They were active workers in the repair industry who had been employed for at least six months. Business owners, sellers of spare parts and accounting officers were not included. The employees were examined at their workplaces and the working conditions were observed. Detailed dermatological examination was performed. The mean age of the 405 workers who participated in the study was 27.7 ± 10.3. The mean working time of employees was 13.3 ± 10.4 years. All of the employees were male. Dermatological diseases were not detected in 144 out of 405 workers (35.6%) and at least one condition was diagnosed in 261 (64.4%). The most frequent diagnosis was callus, hyperkeratosis, clavus (27.7%), followed by nail changes (16.8%) and superficial mycoses (12.1%). Contact dermatitis was seen at a rate of 5.9%. Traumatic lesions such as hyperkeratotic lesions and nail changes were found most frequently. Traumatic lesions were common among individuals who did not use gloves. Most nail changes were localized leuconychia, a finding not reported in the studies on automotive industry workers. In accordance with the literature, irritant contact dermatitis was observed in patients with a history of atopy and who had been working for a long time. Occupational skin diseases comprise an important field in dermatology, deserving much attention. Further studies on occupational dermatology are necessary.

  6. A qualitative engineering analysis of occlusion effects on mandibular fracture repair mechanics.

    Science.gov (United States)

    Katona, Thomas R

    2011-01-01

    Objectives. The purpose of this analytical study was to examine and critique the engineering foundations of commonly accepted biomechanical principles of mandible fracture repair. Materials and Methods. Basic principles of static equilibrium were applied to intact and plated mandibles, but instead of the traditional lever forces, the mandibles were subjected to more realistic occlusal forces. Results. These loading conditions produced stress distributions within the intact mandible that were very different and more complex than the customary lever-based gradient. The analyses also demonstrated the entirely different mechanical environments within intact and plated mandibles. Conclusions. Because the loading and geometry of the lever-idealized mandible is incomplete, the associated widely accepted bone stress distribution (tension on top and compression on the bottom) should not be assumed. Furthermore, the stress gradients within the bone of an intact mandible should not be extrapolated to the mechanical environment within the plated regions of a fractured mandible.

  7. Survival and SOS response induction in ultraviolet B irradiated Escherichia coli cells with defective repair mechanisms.

    Science.gov (United States)

    Prada Medina, Cesar Augusto; Aristizabal Tessmer, Elke Tatjana; Quintero Ruiz, Nathalia; Serment-Guerrero, Jorge; Fuentes, Jorge Luis

    2016-06-01

    Purpose In this paper, the contribution of different genes involved in DNA repair for both survival and SOS induction in Escherichia coli mutants exposed to ultraviolet B radiation (UVB, [wavelength range 280-315 nm]) was evaluated. Materials and methods E. coli strains defective in uvrA, oxyR, recO, recN, recJ, exoX, recB, recD or xonA genes were used to determine cell survival. All strains also had the genetic sulA::lacZ fusion, which allowed for the quantification of SOS induction through the SOS Chromotest. Results Five gene products were particularly important for survival, as follows: UvrA > RecB > RecO > RecJ > XonA. Strains defective in uvrA and recJ genes showed elevated SOS induction compared with the wild type, which remained stable for up to 240 min after UVB-irradiation. In addition, E. coli strains carrying the recO or recN mutation showed no SOS induction. Conclusions The nucleotide excision and DNA recombination pathways were equally used to repair UVB-induced DNA damage in E. coli cells. The sulA gene was not turned off in strains defective in UvrA and RecJ. RecO protein was essential for processing DNA damage prior to SOS induction. In this study, the roles of DNA repair proteins and their contributions to the mechanisms that induce SOS genes in E. coli are proposed.

  8. In vitro assessment of human airway toxicity from major aldehydes in automotive emissions

    Energy Technology Data Exchange (ETDEWEB)

    Grafstroem, R.C. [Karolinska Inst., Stockholm (Sweden). Inst. of Environmental Medicine

    1997-09-01

    Automotive exhausts can significantly contribute to the levels of reactive aldehydes, including formaldehyde, acetaldehyde and acrolein, in urban air. The use of alcohols as an alternative fuel for gasoline or diesel may further increase these emissions. Since it is unclear if aldehyde inhalation may induce pathological states, including cancer, in human airways, the toxic properties of the above-mentioned aldehydes were studied in cultured target cell types. Each aldehyde modified vital cellular functions in a dose-dependent manner, and invariably inhibited growth and induced abnormal terminal differentiation. Decreases of cellular thiols and increases of intracellular Ca{sup 2+} were observed, and moreover, variable types and amounts of short-lived or persistent genetic damage were induced. The concentrations required for specified levels of a particular type of injury varied up to 10000-fold among the aldehydes. Overall, distinctive patterns of cytopathological activity were observed, which differed both qualitatively and quantitatively among the aldehydes. Finally, aldehydes inhibited DNA repair processes and increased cytotoxicity and mutagenesis in synergy with other known toxicants, indicating that aldehydes may also enhance damage by other constituents in automotive exhausts. In summary, the aldehydes, notably {sup m}u{sup M}-mM formaldehyde, caused pathological effects and induced mechanisms that relate to acute toxicity and cancer development in airway epithelial cells. Since `no-effect` levels may not exist for carcinogenic agents, the overall results support a need for elimination of aldehydes in automotive exhausts. 41 refs

  9. [Metallothionein-I/II in brain injury repair mechanism and its application in forensic medicine].

    Science.gov (United States)

    Li, Dong; Li, Ru-bo; Lin, Ju-li

    2013-10-01

    Metallothionein (MT) is a kind of metal binding protein. As an important member in metallothionein family, MT-I/II regulates metabolism and detoxication of brain metal ion and scavenges free radicals. It is capable of anti-inflammatory response and anti-oxidative stress so as to protect the brain tissue. During the repair process of brain injury, the latest study showed that MT-I/II could stimulate brain anti-inflammatory factors, growth factors, neurotrophic factors and the expression of the receptor, and promote the extension of axon of neuron, which makes contribution to the regeneration of neuron and has important effect on the recovery of brain injury. Based on the findings, this article reviews the structure, expression, distribution, adjustion, function, mechanism in the repair of brain injury of MT-I/II and its application prospect in forensic medicine. It could provide a new approach for the design and manufacture of brain injury drugs as well as for age estimation of the brain injury.

  10. High integrity automotive castings

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, D. [Eck Industries Inc., St. Manitowoc, WI (United States)

    2007-07-01

    This paper described the High Integrity Magnesium Automotive Casting (HI-MAC) program, which was developed to ensure the widespread adoption of magnesium in structural castings. The program will encourage the use of low pressure permanent molds, squeeze casting, and electromagnetic pumping of magnesium into dies. The HI-MAC program is currently investigating new heat treatment methods, and is in the process of creating improved fluid flow and solidification modelling to produce high volume automotive components. In order to address key technology barriers, the program has been divided into 8 tasks: (1) squeeze casting process development; (2) low pressure casting technology; (3) thermal treatment; (4) microstructure control; (5) computer modelling and properties; (6) controlled molten metal transfer and filling; (7) emerging casting technologies; and (8) technology transfer throughout the automotive value chain. Technical challenges were outlined for each of the tasks. 1 ref., 3 tabs., 5 figs.

  11. Understanding the molecular mechanism of formaldehyde-induced DNA-protein crosslink repair

    Science.gov (United States)

    Formaldehyde induces DNA-protein crosslinks (DPCs) in several experimental in vitro and in vivo test systems, as well as in exposed human workers. DPCs are repaired by several DNA repair pathways in different species, but the molecular understanding of DPC repair in human tissues...

  12. Identification for automotive systems

    CERN Document Server

    Hjalmarsson, Håkan; Re, Luigi

    2012-01-01

    Increasing complexity and performance and reliability expectations make modeling of automotive system both more difficult and more urgent. Automotive control has slowly evolved from an add-on to classical engine and vehicle design to a key technology to enforce consumption, pollution and safety limits. Modeling, however, is still mainly based on classical methods, even though much progress has been done in the identification community to speed it up and improve it. This book, the product of a workshop of representatives of different communities, offers an insight on how to close the gap and exploit this progress for the next generations of vehicles.

  13. Automotive NVH technology

    CERN Document Server

    Nijman, Eugenius; Priebsch, Hans-Herwig

    2016-01-01

    This book presents seven chapters examining selected noise, vibration and harshness (NVH) topics that are highly relevant for automotive vehicle development. These include applications following the major trends toward increased passenger comfort, vehicle electrification and lightweight design. The authors of the seven chapters, all of which are experts from the automotive industry and academia, present the foremost challenges and potential solutions in this demanding field. Among others, applications for sound optimization in downsized engines, noise optimization in electric powertrains, weight reduction options for exhaust systems, porous materials description, and the vibro-acoustic analysis of geared systems are discussed.

  14. Automotive component failures

    CSIR Research Space (South Africa)

    Heyes, AM

    1998-06-01

    Full Text Available be expected[ 023 A[ M[ HEYES Fig[ 6[ Low magni_cation fractograph showing the seam defect "S#\\ fatigue area "F# and the brittle fracture area "B#[ Fig[ 7[ Fracture surface marked F in Fig[ 6\\ typical of a fatigue fracture surface in a high strength steel... Ltd[ All rights reserved[ Keywords] Accident investigation\\ automotive failures\\ decarburization\\ fatigue\\ weld fatigue[ 0[ INTRODUCTION Failure of automotive components is an occurrence which a}ects the life of almost every person at one stage...

  15. A new theoretical formula for fractionated radiotherapy based on a saturable cellular repair mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Reyes, A. (Servicio de Radioterapia, Hospital Clinico y Provincial de Barcelona (Spain)); Farrus, B. (Servicio de Radioterapia, Hospital Clinico y Provincial de Barcelona (Spain)); Biete, A. (Servicio de Radioterapia, Hospital Clinico y Provincial de Barcelona (Spain))

    1993-01-01

    Recently we have published a new model of survival cellular response to radiation based on the existence of a saturable cellular repair mechanism. In the present paper we extend the predictions of this model of calculating the change in total dose necessary to achieve an equal response in a tissue when the dose per fraction in a radiotherapy fractionation schedule is varied. The model provides a new explanation of the difference between late and early radiation reactions. Results obtained from the model for different tissues and standard fractionation schedules are approximately equal to those obtained by the L.Q. (linear-quadratic) model. The model is compatible with in vitro survival curves that are straight at high doses. (orig.).

  16. The Prevalence of Musculoskeletal Disorder and the Association with Risk Factors among Auto Repair Mechanics in Klang Valley, Malaysia

    Directory of Open Access Journals (Sweden)

    Ahmad Faisal AHMAD NASARUDDIN

    2015-10-01

    Full Text Available Background: The primary objective of this study was to determine the association between risk factors and the prevalence of musculoskeletal disorder (MSD among auto repair mechanics in Klang Valley, Malaysia.Methods: Overall, 191 mechanics from eight auto repair centers in Klang Valley, Malaysia were stratified sampling as participants of this study. A modified version of the general Standardized Nordic Questionnaire was used for analyses of perceived MSD in nine different parts of the body. Rapid Upper Limb Assessment (RULA, vibration measurement on hand power tool, questionnaire on job content, force exertion was used in this study. Direct logistic regression was performed to assess the impact of risk factors on the MSD prevalence. The probability limits for evaluating statistical significance was P < 0.05.Results: 87.4% of auto repair mechanics suffered from MSD. Logistic regression analysis revealed that factors were associated with symptoms on MSD: RULA (7.933, 95% CI 4.637-13.573 and orceful exertion (3.173, 95% CI 1.194 – 8.432. The magnitude of vibration of power tool exceeds action level 2.5m/s2 with (Mean=3.99+S.E. 0.071 and showed significant association with MSD in this study (P<0.05.Conclusion: Auto repair mechanics at auto repair centers in Klang Valley are likely to be exposed to a variety of ergonomic hazards and risk factors. Therefore, ergonomics awareness between employer and employee with training and information sharing shall be increase to reduce the prevalence of MSDs. Keywords: Musculoskeletal disorder (MSD, Auto repair mechanics, Hand arm vibration

  17. Dynamic Route Shortening and Route Repairing Mechanism for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    T. R. Rangaswamy

    2012-01-01

    Full Text Available Problem statement: Ad hoc Networks are wireless networks without any fixed infrastructure. The network topology changes frequently and unpredictably due to the random movement of the nodes. The ad hoc on Demand Distant Vector Routing (AODV protocol works in a dynamic fashion, by establishing a route on demand and continues that route until it breaks. Due to the changing network topology of ad hoc networks, if other routes with less hop count become available, the network topology is not able to adapt until the route break occurs. Hence in the route shortening scheme is some redundant nodes in the active route is replaced with a node that is not on the active route. When there is any link failure between any two nodes, the alternative route with optimum route to be constructed and not sending RRER message to the source node to initiate the route discovery process again. Approach: This study proposes a new routing protocol called, Dynamic Route Shortening and Repairing mechanism (DRSR. The route shortening is incorporated with route repairing mechanism, to improve the performance of the AODV. The route shortening scheme works by replacing some redundant nodes in the active route, with a node that is not on the active route. If there is a link failure between the two nodes, the route repairing mechanism repairs the route, by using the nodes that are close enough to the route to overhear the message. Whenever the links go down, the DRSR replaces the failed links with the optimum route that is adjacent to the main route and not sending and RRER message to the source node to initiate the route discovery process again. The alternative route construction process could be initiated at any time, not just when a route has failed. The dynamically constructed alternative route’s information is passed on to the upstream nodes, which then determine by themselves when to direct their packets to the Normal 0 false false false EN-US X

  18. Bringing Excellence to Automotive

    Science.gov (United States)

    Večeřa, Pavel; Paulová, Iveta

    2012-12-01

    Market situation and development in recent years shows, that organization's ability to meet customer requirements is not enough. Successful organizations are able to exceed the expectations of all stakeholders. They are building their excellence systematically. Our contribution basically how the excellence in automotive is created using EFQM Excellence Model in Total Quality Management.

  19. DNA Repair Mechanisms and Their Biological Roles in the Malaria Parasite Plasmodium falciparum

    Science.gov (United States)

    Lee, Andrew H.; Symington, Lorraine S.

    2014-01-01

    SUMMARY Research into the complex genetic underpinnings of the malaria parasite Plasmodium falciparum is entering a new era with the arrival of site-specific genome engineering. Previously restricted only to model systems but now expanded to most laboratory organisms, and even to humans for experimental gene therapy studies, this technology allows researchers to rapidly generate previously unattainable genetic modifications. This technological advance is dependent on DNA double-strand break repair (DSBR), specifically homologous recombination in the case of Plasmodium. Our understanding of DSBR in malaria parasites, however, is based largely on assumptions and knowledge taken from other model systems, which do not always hold true in Plasmodium. Here we describe the causes of double-strand breaks, the mechanisms of DSBR, and the differences between model systems and P. falciparum. These mechanisms drive basic parasite functions, such as meiosis, antigen diversification, and copy number variation, and allow the parasite to continually evolve in the contexts of host immune pressure and drug selection. Finally, we discuss the new technologies that leverage DSBR mechanisms to accelerate genetic investigations into this global infectious pathogen. PMID:25184562

  20. DNA repair mechanisms and their biological roles in the malaria parasite Plasmodium falciparum.

    Science.gov (United States)

    Lee, Andrew H; Symington, Lorraine S; Fidock, David A

    2014-09-01

    Research into the complex genetic underpinnings of the malaria parasite Plasmodium falciparum is entering a new era with the arrival of site-specific genome engineering. Previously restricted only to model systems but now expanded to most laboratory organisms, and even to humans for experimental gene therapy studies, this technology allows researchers to rapidly generate previously unattainable genetic modifications. This technological advance is dependent on DNA double-strand break repair (DSBR), specifically homologous recombination in the case of Plasmodium. Our understanding of DSBR in malaria parasites, however, is based largely on assumptions and knowledge taken from other model systems, which do not always hold true in Plasmodium. Here we describe the causes of double-strand breaks, the mechanisms of DSBR, and the differences between model systems and P. falciparum. These mechanisms drive basic parasite functions, such as meiosis, antigen diversification, and copy number variation, and allow the parasite to continually evolve in the contexts of host immune pressure and drug selection. Finally, we discuss the new technologies that leverage DSBR mechanisms to accelerate genetic investigations into this global infectious pathogen.

  1. The Molecular Mechanisms and the Role of hnRNP K Protein Post- Translational Modification in DNA Damage Repair.

    Science.gov (United States)

    Lu, Jing; Gao, Feng-Hou

    2017-01-01

    DNA damage repair is a kind of cellular self-protection mechanism in which some relevant proteins are activated when DNA damage response occurs in order to maintain the intracellular function stability and structure integrity. Post-translational modifications (PTMs) of proteins can rapidly confer to them more complicated structure and sophisticated function by covalently combining different small molecules with target proteins, which in turn plays an important regulatory role in DNA damage repair. It was reported that heterogeneous nuclear ribonucleoprotein K (hnRNP K) could be involved in DNA damage repair process under the regulation of its many post-translational modifications, including methylation, ubiquitination, sumoylation and phosphorylation. Here, we reviewed molecular mechanisms of hnRNP K protein post-translational modifications and their role in DNA damage repair, which will promote our understanding of how hnRNP K participating in the repair process to maintain the normal operation of biological activities in the cells. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. Development of repair mechanism of FSX-414 based 1st stage nozzle of gas turbine

    Science.gov (United States)

    Rahman, Md. Tawfiqur

    2017-06-01

    This paper describes the failure mechanism and repair technology of 1st stage nozzle or vane of industrial gas turbine which is made of cobalt based super alloy FSX-414. 1st stage nozzles or vanes are important stationery components of gas turbine based power plant. Those are the parts of hot gas path components of gas turbine and their manufacturing process is casting. At present, it is widely accepted that gas turbine based combined cycle power plant is the most efficient and cost effective solution to generate electricity. One of the factors of high efficiency of this type of gas turbine is the increase of its turbine inlet temperature. As an effect of this factor and in conjunction with some other factors, the 1st stage nozzle of gas turbine operates under extremely high temperature and thermal stresses. As a result, the design lifetime of these components becomes limited. Furthermore, attention on nozzles or vanes is required in order to achieve their design lifetime. However, due to unfriendly operational condition and environmental effect, anytime failure can occur on these heat resistant alloy based components which may lead to severe damage of gas turbine. To mitigate these adverse effects, schedule maintenance is performed on a predetermined time interval of hot gas path components of gas turbine based power plant. This paper addresses common failures in gas turbine's 1st stage nozzles or vanes. Usually these are repaired by using ADH process but for several reasons ADH process is not used here. Hence the challenging task is performed using gas tungsten arc welding which is presented in this article systematically.

  3. Course Outline for Lesson Plans for Pre-Employment Laboratory Training in CVAE-VEH Farm and Ranch Mechanical Repair.

    Science.gov (United States)

    Texas A and M Univ., College Station. Vocational Instructional Services.

    This packet contains 88 lesson plans for a laboratory course in farm and ranch mechanical repair. The lesson plans are organized into six units covering the following topics: occupational information, construction and maintenance (safety, farm carpentry, farm water supply and sanitation, farm electricity, concrete), hot metal work (oxyacetylene…

  4. Automotive stamped part fatigue design

    Directory of Open Access Journals (Sweden)

    Caudoux Mélanie

    2014-06-01

    Full Text Available Fatigue design of automotive axle parts is of prior concern because of these are high safety parts and they are expected to drive the overall vehicle mass reduction. In this framework, the stamping process is widely used to form axle parts, before assembling them by welding. Consequently, the mechanical and physical characteristics of the blank sheet are modified, having a strong influence on the fatigue behavior. In this paper, we address the consequences of the stamped process on the fatigue design and how they may be effectively taken into account in the automotive industry. Actually, the coupling between the stamping process and the fatigue design is under development at PSA Peugeot Citroën Company since several years. Such an analysis deals with some major topics: thickness variation, plastic hardening and deformation, and residual stress. All of these ingredients result in fatigue criteria evolutions: it is important to stress that the stamping process can have advantageous or disadvantageous consequences on the fatigue design. This is here highlighted on some examples, dealing with front and rear axles.

  5. Automotive Technology Evolved by Electrical and Electronic Systems

    Science.gov (United States)

    Teratani, Tatsuo; Okuma, Shigeru

    Automotive electrical and electronic systems, e.g. EHV, FCV, future X-By-Wire, have recently been introduced or planned in place of mechanical systems. Drivers are demanding environmental performance (fuel consumption and weight reduction), safety and comfort. For general use of the new technologies, evolution of the automotive technology is required, including energy conversion efficiency improvement, size and weight reduction of components, cost reduction and high reliability. This paper discusses and summarizes the next generation power systems, the future vehicle image, power source combinations, and problems to be solved for development of automotive electronics.

  6. Introduction of a New Suture Method in Repair of Peripheral Nerves Injured with a Sharp Mechanism

    Directory of Open Access Journals (Sweden)

    Alireza Saied

    2015-09-01

    Full Text Available Background: The standard method for repair of an injured peripheal nerve is epineural repair with separate sutures. Herein we describe a method in which the nerve is sutured with continous sutures. In fact this method has not been utilized for nerve repair previously and our purpose was to compare it to the standard method. If it proved to be successful it would replace the standard method in certain circumstances. Methods: The proposal of the clinical trial was given a reference number form the ethics comitee. 25 dogs in which the scaitic nerve was cut by a sharp blade under genaeral anesthesia were divided randomly into three groups: control (5 dogs, repair of sciatic nerve with simple sutures (10 and repair with continous sutures (10. In the control group the nerve was not repaired at all. After 6 weeks the dogs were killed and the nerve was studied by light and electronic microscopes. The amount of consumed suture material, time of repair, myelin thickness and axon diiameter were examined. Ultrastructural studies were performed to assess degeneration and regeneration findings. Results: Time of repair and the amount of consumed suture material were significantly lower in the continous group (P

  7. Rotordynamics of automotive turbochargers

    CERN Document Server

    Nguyen-Schäfer, Hung

    2015-01-01

    Rotordynamics of automotive turbochargers is dealt with in this book encompassing the widely working field of small turbomachines under real operating conditions at the very high rotor speeds up to 300000 rpm. The broadly interdisciplinary field of turbocharger rotordynamics involves 1) Thermodynamics and Turbo-Matching of Turbochargers 2) Dynamics of Turbomachinery 3) Stability Analysis of Linear Rotordynamics with the Eigenvalue Theory 4) Stability Analysis of Nonlinear Rotordynamics with the Bifurcation Theory 5) Bearing Dynamics of the Oil Film using the Two-Phase Reynolds Equation 6) Computation of Nonlinear Responses of a Turbocharger Rotor 7) Aero and Vibroacoustics of Turbochargers 8) Shop and Trim Balancing at Two Planes of the Rotor 9) Tribology of the Bearing Surface Roughness 10) Design of Turbocharger Platforms using the Similarity Laws The rotor response of an automotive turbocharger at high rotor speeds is studied analytically, computationally, and experimentally. Due to the nonlinear character...

  8. Current Automotive Holometry Studies

    Science.gov (United States)

    Marchi, Mitchell M.; Snyder, D. S.

    1990-04-01

    Holometry studies of automotive body and powertrain components have become a very useful high resolution test methodology to knowledgeable Ford engineering personnel. Current examples of studies that represent the static or dynamic operational conditions of the automotive test component are presented. Continuous wave laser holometry, computer aided holometry (CAH) and pulsed laser holometry were the holometric techniques used to study the following subjects: (1) body in prime (BIP) vibration modes, (2) transmission flexplate stud-torque converter deformation due to engine torque pulses, (3) engine cylinder head and camshaft support structure deformation due to cylinder pressure and (4) engine connecting rod/cap lift-off. Static and dynamic component loading and laboratory techniques required to produce usable and valid test results are discussed along with possible conclusions for the engineering concerns.

  9. Automotive Industry in Malaysia

    DEFF Research Database (Denmark)

    Wad, Peter; Govindaraju, V.G.R. Chandran

    2011-01-01

    expanded in terms of sales, production, employment and local content, but failed in industrial upgrading and international competitiveness. The failures can be attributed to (a) lack of political promotion for high challenge-high support environment, (b) low technological and marketing capabilities and (c......This paper explains the evolution and assesses the development of the Malaysian automotive industry within the premise of infant industry and trade protection framework as well as extended arguments of infant industry using a global value chain perspective. The Malaysian automotive industry......) limited participation in the global value chain. Although the Malaysian infant industry protection policy comprised many promising initiatives, the national and the overall domestic automobile industry ended up as a captive of the regionalised Japanese keiretsu system in automobile manufacturing. A new...

  10. Automotive systems engineering

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, Markus [Technische Univ. Braunschweig (Germany). Inst. fuer Regelungstechnik; Winner, Hermann (eds.) [Technische Univ. Darmstadt (Germany). Fachgebiet Fahrzeugtechnik

    2013-06-01

    Innovative state-of-the-art book. Presents brand new results of a joint workshop in the field of automotive systems engineering. Recommendable to students for further reading even though not a primary text book. This book reflects the shift in design paradigm in automobile industry. It presents future innovations, often referred as ''automotive systems engineering''. These cause fundamental innovations in the field of driver assistance systems and electro-mobility as well as fundamental changes in the architecture of the vehicles. New driving functionalities can only be realized if the software programs of multiple electronic control units work together correctly. This volume presents the new and innovative methods which are mandatory to master the complexity of the vehicle of the future.

  11. Mechanical Stress Changes the Complex Interplay Between HO-1, Inflammation and Fibrosis, During Excisional Wound Repair

    Science.gov (United States)

    Cremers, Niels A. J.; Suttorp, Maarten; Gerritsen, Marlous M.; Wong, Ronald J.; van Run-van Breda, Coby; van Dam, Gooitzen M.; Brouwer, Katrien M.; Kuijpers-Jagtman, Anne Marie; Carels, Carine E. L.; Lundvig, Ditte M. S.; Wagener, Frank A. D. T. G.

    2015-01-01

    Mechanical stress following surgery or injury can promote pathological wound healing and fibrosis, and lead to functional loss and esthetic problems. Splinted excisional wounds can be used as a model for inducing mechanical stress. The cytoprotective enzyme heme oxygenase-1 (HO-1) is thought to orchestrate the defense against inflammatory and oxidative insults that drive fibrosis. Here, we investigated the activation of the HO-1 system in a splinted and non-splinted full-thickness excisional wound model using HO-1-luc transgenic mice. Effects of splinting on wound closure, HO-1 promoter activity, and markers of inflammation and fibrosis were assessed. After seven days, splinted wounds were more than three times larger than non-splinted wounds, demonstrating a delay in wound closure. HO-1 promoter activity rapidly decreased following removal of the (epi)dermis, but was induced in both splinted and non-splinted wounds during skin repair. Splinting induced more HO-1 gene expression in 7-day wounds; however, HO-1 protein expression remained lower in the epidermis, likely due to lower numbers of keratinocytes in the re-epithelialization tissue. Higher numbers of F4/80-positive macrophages, αSMA-positive myofibroblasts, and increased levels of the inflammatory genes IL-1β, TNF-α, and COX-2 were present in 7-day splinted wounds. Surprisingly, mRNA expression of newly formed collagen (type III) was lower in 7-day wounds after splinting, whereas, VEGF and MMP-9 were increased. In summary, these data demonstrate that splinting delays cutaneous wound closure and HO-1 protein induction. The pro-inflammatory environment following splinting may facilitate higher myofibroblast numbers and increase the risk of fibrosis and scar formation. Therefore, inducing HO-1 activity against mechanical stress-induced inflammation and fibrosis may be an interesting strategy to prevent negative effects of surgery on growth and function in patients with orofacial clefts or in patients with

  12. Aero and vibroacoustics of automotive turbochargers

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen-Schaefer, Hung [Bosch Mahle Turbo Systems GmbH, Stuttgart (Germany)

    2013-02-01

    First book about the aeroacoustics of automotive turbochargers. Author of the book ''Rotordynamics of Automotive Turbochargers'', Springer, 2012. Written by an R and D expert in the turbocharger industry. Aero and Vibroacoustics of Automotive Turbochargers is a topic involving aspects from the working fields of thermodynamics of turbomachinery, aerodynamics, rotordynamics, and noise propagation computation. In this broadly interdisciplinary subject, thermodynamics of turbomachinery is used to design the turbocharger and to determine its operating conditions. Aerodynamics is needed to study the compressor flow dynamics and flow instabilities of rotating stall and surge, which can produce growling and whining-type noises. Rotordynamics is necessary to study rotor unbalance and self-excited oil-whirl instabilities, which lead to whistling and constant tone-type noises in rotating floating oil-film type bearings. For the special case of turbochargers using ball bearings, some high-order harmonic and wear noises also manifest in the rotor operating range. Lastly, noise propagation computation, based on Lighthill's analogy, is required to investigate airborne noises produced by turbochargers in passenger vehicles. The content of this book is intended for advanced undergraduates, graduates in mechanical engineering, research scientists and practicing engineers who want to better understand the interactions between these working fields and the resulting impact on the interesting topic of Aero and Vibroacoustics of Automotive Turbochargers.

  13. Kenaf Fiber Composite in Automotive Industry: An Overview

    Directory of Open Access Journals (Sweden)

    F. Hassan

    2017-02-01

    Full Text Available Recently, natural fibers become an attractive to automotive industry as an alternative reinforcement for glass fiber reinforced thermoplastics. Additionally, natural fiber components in the automotive industry can provide numerous advantages compared to synthetic conventional such as reduction of weight and cost,  recyclability, renewability and in addition to eco-efficiency. Thus, the use of natural fibers in automotive industry has shown increasingly stringent environmental criteria. Furthermore, amongst grouped bast fibers such as flax, hemp, jute, ramie and kenaf; kenaf fiber seen as potential natural fiber with robust mechanical properties. Kenaf fiber had been explored to enhance desired mechanical properties as an automotive structural components. As usual, natural fibres have some issues and disadvantages when used as reinforcements for polymeric composites. Therefore, some modification performed on fibers such as chemical treatment was carried out. In addition, the use of a coupling agent and a plasticizer can also increase fiber-matrix adhesive bonding.

  14. Cell and protein compatible 3D bioprinting of mechanically strong constructs for bone repair.

    Science.gov (United States)

    Sawkins, M J; Mistry, P; Brown, B N; Shakesheff, K M; Bonassar, L J; Yang, J

    2015-07-02

    Rapid prototyping of bone tissue engineering constructs often utilizes elevated temperatures, organic solvents and/or UV light for materials processing. These harsh conditions may prevent the incorporation of cells and therapeutic proteins in the fabrication processes. Here we developed a method for using bioprinting to produce constructs from a thermoresponsive microparticulate material based on poly(lactic-co-glycolic acid) at ambient conditions. These constructs could be engineered with yield stresses of up to 1.22 MPa and Young's moduli of up to 57.3 MPa which are within the range of properties of human cancellous bone. Further study showed that protein-releasing microspheres could be incorporated into the bioprinted constructs. The release of the model protein lysozyme from bioprinted constructs was sustainted for a period of 15 days and a high degree of protein activity could be measured up to day 9. This work suggests that bioprinting is a viable route to the production of mechanically strong constructs for bone repair under mild conditions which allow the inclusion of viable cells and active proteins.

  15. Human umbilical cord mesenchymal stem cells promote peripheral nerve repair via paracrine mechanisms

    Directory of Open Access Journals (Sweden)

    Zhi-yuan Guo

    2015-01-01

    Full Text Available Human umbilical cord-derived mesenchymal stem cells (hUCMSCs represent a promising young-state stem cell source for cell-based therapy. hUCMSC transplantation into the transected sciatic nerve promotes axonal regeneration and functional recovery. To further clarify the paracrine effects of hUCMSCs on nerve regeneration, we performed human cytokine antibody array analysis, which revealed that hUCMSCs express 14 important neurotrophic factors. Enzyme-linked immunosorbent assay and immunohistochemistry showed that brain-derived neurotrophic factor, glial-derived neurotrophic factor, hepatocyte growth factor, neurotrophin-3, basic fibroblast growth factor, type I collagen, fibronectin and laminin were highly expressed. Treatment with hUCMSC-conditioned medium enhanced Schwann cell viability and proliferation, increased nerve growth factor and brain-derived neurotrophic factor expression in Schwann cells, and enhanced neurite growth from dorsal root ganglion explants. These findings suggest that paracrine action may be a key mechanism underlying the effects of hUCMSCs in peripheral nerve repair.

  16. Rapid Identification of Chemoresistance Mechanisms Using Yeast DNA Mismatch Repair Mutants.

    Science.gov (United States)

    Ojini, Irene; Gammie, Alison

    2015-07-21

    Resistance to cancer therapy is a major obstacle in the long-term treatment of cancer. A greater understanding of drug resistance mechanisms will ultimately lead to the development of effective therapeutic strategies to prevent resistance from occurring. Here, we exploit the mutator phenotype of mismatch repair defective yeast cells combined with whole genome sequencing to identify drug resistance mutations in key pathways involved in the development of chemoresistance. The utility of this approach was demonstrated via the identification of the known CAN1 and TOP1 resistance targets for two compounds, canavanine and camptothecin, respectively. We have also experimentally validated the plasma membrane transporter HNM1 as the primary drug resistance target of mechlorethamine. Furthermore, the sequencing of mitoxantrone-resistant strains identified inactivating mutations within IPT1, a gene encoding inositolphosphotransferase, an enzyme involved in sphingolipid biosynthesis. In the case of bactobolin, a promising anticancer drug, the endocytosis pathway was identified as the drug resistance target responsible for conferring resistance. Finally, we show that that rapamycin, an mTOR inhibitor previously shown to alter the fitness of the ipt1 mutant, can effectively prevent the formation of mitoxantrone resistance. The rapid and robust nature of these techniques, using Saccharomyces cerevisiae as a model organism, should accelerate the identification of drug resistance targets and guide the development of novel therapeutic combination strategies to prevent the development of chemoresistance in various cancers.

  17. Effect of Mechanical Surface Treatment on the Repair Bond Strength of the Silorane-based Composite Resin

    Directory of Open Access Journals (Sweden)

    Parnian Alizadeh Oskoee

    2014-06-01

    Full Text Available Background and aims. A proper bond must be created between the existing composite resin and the new one for successful repair. The aim of this study was to compare the effect of three mechanical surface treatments, using diamond bur, air abrasion, and Er,Cr:YSGG laser, on the repair bond strength of the silorane-based composite resin. Materials and methods. Sixty cylindrical composite resin specimens (Filtek Silorane were fabricated and randomly divided into four groups according to surface treatment: group 1 (control group without any mechanical surface treatment, groups 24 were treated with air abrasion, Er,Cr:YSGG laser, and diamond bur, respectively. In addition, a positive control group was assigned in order to measure the cohesive strength. Silorane bonding agent was used in groups 14 before adding the new composite resin. Then, the specimens were subjected to a shear bond strength test and data was analyzed using one-way ANOVA and post hoc Tukey tests at a significance level of P < 0.05. The topographical effects of surface treatments were characterized under a scanning electron microscope. Results. There were statistically significant differences in the repair bond strength values between groups 1 and 2 and groups 3 and 4 (P < 0.001. There were no significant differences between groups 1 and 2 (P = 0.98 and groups 3 and 4 (P = 0.97. Conclusion. Surface treatment using Er,Cr:YSGG laser and diamond bur were effective in silorane-based composite resin repair.

  18. Horizontal gene transfer regulation in bacteria as a "spandrel" of DNA repair mechanisms.

    Directory of Open Access Journals (Sweden)

    Saliou Fall

    might have led the bacteria to hijack DNA repair mechanisms in order to generate genetic diversity without losing too much genomic stability.

  19. Protecting DNA from errors and damage: an overview of DNA repair mechanisms in plants compared to mammals.

    Science.gov (United States)

    Spampinato, Claudia P

    2017-05-01

    The genome integrity of all organisms is constantly threatened by replication errors and DNA damage arising from endogenous and exogenous sources. Such base pair anomalies must be accurately repaired to prevent mutagenesis and/or lethality. Thus, it is not surprising that cells have evolved multiple and partially overlapping DNA repair pathways to correct specific types of DNA errors and lesions. Great progress in unraveling these repair mechanisms at the molecular level has been made by several talented researchers, among them Tomas Lindahl, Aziz Sancar, and Paul Modrich, all three Nobel laureates in Chemistry for 2015. Much of this knowledge comes from studies performed in bacteria, yeast, and mammals and has impacted research in plant systems. Two plant features should be mentioned. Plants differ from higher eukaryotes in that they lack a reserve germline and cannot avoid environmental stresses. Therefore, plants have evolved different strategies to sustain genome fidelity through generations and continuous exposure to genotoxic stresses. These strategies include the presence of unique or multiple paralogous genes with partially overlapping DNA repair activities. Yet, in spite (or because) of these differences, plants, especially Arabidopsis thaliana, can be used as a model organism for functional studies. Some advantages of this model system are worth mentioning: short life cycle, availability of both homozygous and heterozygous lines for many genes, plant transformation techniques, tissue culture methods and reporter systems for gene expression and function studies. Here, I provide a current understanding of DNA repair genes in plants, with a special focus on A. thaliana. It is expected that this review will be a valuable resource for future functional studies in the DNA repair field, both in plants and animals.

  20. Alkylation damage in DNA and RNA--repair mechanisms and medical significance

    DEFF Research Database (Denmark)

    Drabløs, Finn; Feyzi, Emadoldin; Aas, Per Arne

    2004-01-01

    Alkylation lesions in DNA and RNA result from endogenous compounds, environmental agents and alkylating drugs. Simple methylating agents, e.g. methylnitrosourea, tobacco-specific nitrosamines and drugs like temozolomide or streptozotocin, form adducts at N- and O-atoms in DNA bases. These lesions...... are mainly repaired by direct base repair, base excision repair, and to some extent by nucleotide excision repair (NER). The identified carcinogenicity of O(6)-methylguanine (O(6)-meG) is largely caused by its miscoding properties. Mutations from this lesion are prevented by O(6)-alkylG-DNA alkyltransferase......, inactivation of the MMR system in an AGT-defective background causes resistance to the killing effects of O(6)-alkylating agents, but not to the mutagenic effect. Bifunctional alkylating agents, such as chlorambucil or carmustine (BCNU), are commonly used anti-cancer drugs. DNA lesions caused by these agents...

  1. Dynamics and Mechanism of Efficient DNA Repair Reviewed by Active-Site Mutants

    Science.gov (United States)

    Tan, Chuang; Liu, Zheyun; Li, Jiang; Guo, Xunmin; Wang, Lijuan; Zhong, Dongping

    2010-06-01

    Photolyases repair the UV-induced pyrimidine dimers in damage DNA via a photoreaction which includes a series of light-driven electron transfers between the two-electron-reduced flavin cofactor FADH^- and the dimer. We report here our systematic studies of the repair dynamics in E. coli photolyase with mutation of several active-site residues. With femtosecond resolution, we observed the significant change in the forward electron transfer from the excited FADH^- to the dimer and the back electron transfer from the repaired thymines by mutation of E274A, R226A, R342A, N378S and N378C. We also found that the mutation of E274A accelerates the bond-breaking of the thymine dimer. The dynamics changes are consistent with the quantum yield study of these mutants. These results suggest that the active-site residues play a significant role, structurally and chemically, in the DNA repair photocycle.

  2. Automotive mechatronics automotive networking, driving stability systems, electronics

    CERN Document Server

    2015-01-01

    As the complexity of automotive vehicles increases this book presents operational and practical issues of automotive mechatronics. It is a comprehensive introduction to controlled automotive systems and provides detailed information of sensors for travel, angle, engine speed, vehicle speed, acceleration, pressure, temperature, flow, gas concentration etc. The measurement principles of the different sensor groups are explained and examples to show the measurement principles applied in different types. Contents Basics of mechatronics.- Architecture.- Electronic control unit.- Software development.- Basic principles of networking.- Automotive networking.- Bus systems.- Automotive sensors.- Sensor measuring principles.- Sensor types.- Electric actuators.- Electrohydraulic actuators.- Electronic transmission control.- Electronic transmission control unit.- Modules for transmission control.- Antilock braking system.- Traction control system.- Electronic stability program.- Automatic brake functions.- Hydraulic modu...

  3. DNA repair. [UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, R.

    1978-01-01

    Some topics discussed are as follows: difficulty in extrapolating data from E. coli to mammalian systems; mutations caused by UV-induced changes in DNA; mutants deficient in excision repair; other postreplication mechanisms; kinds of excision repair systems; detection of repair by biochemical or biophysical means; human mutants deficient in repair; mutagenic effects of UV on XP cells; and detection of UV-repair defects among XP individuals. (HLW)

  4. Reliability in automotive ethernet networks

    DEFF Research Database (Denmark)

    Soares, Fabio L.; Campelo, Divanilson R.; Yan, Ying;

    2015-01-01

    This paper provides an overview of in-vehicle communication networks and addresses the challenges of providing reliability in automotive Ethernet in particular.......This paper provides an overview of in-vehicle communication networks and addresses the challenges of providing reliability in automotive Ethernet in particular....

  5. Automotive battery technology

    CERN Document Server

    Watzenig, Daniel

    2014-01-01

    The use of electrochemical energy storage systems in automotive applications also involves new requirements for modeling these systems, especially in terms of model depth and model quality. Currently, mainly simple application-oriented models are used to describe the physical behavior of batteries. This book provides a step beyond of state-of-the-art modeling showing various different approaches covering following aspects: system safety, misuse behavior (crash, thermal runaway), battery state estimation and electrochemical modeling with the needed analysis (pre/post mortem). All this different approaches are developed to support the overall integration process from a multidisciplinary point-of-view and depict their further enhancements to this process.

  6. Automotive systems engineering

    CERN Document Server

    Winner, Hermann

    2013-01-01

    This book reflects the shift in design paradigm in automobile industry. It presents future innovations, often referred as  “automotive systems engineering”.  These cause fundamental innovations in the field of driver assistance systems and electro-mobility as well as fundamental changes in the architecture of the vehicles. New driving functionalities can only be realized if the software programs of multiple electronic control units work together correctly. This volume presents the new and innovative methods which are mandatory to master the complexity of the vehicle of the future.

  7. Ultracapacitors for automotive applications

    Science.gov (United States)

    Ashtiani, Cyrus; Wright, Randy; Hunt, Gary

    In response to a growing consensus in the auto industry that ultracapacitors can potentially play a key role in the modern vehicle power distribution network, a task force was created at the United States Advanced Battery Consortium (USABC) to tackle issues facing the fledging industry. The task force embarked on first developing and establishing standards for performance and abuse tolerance of ultracapacitors in collaboration with the U.S. Department of Energy and National Labs. Subsequently, potential applications in the automotive industry were identified and a consensus requirement specification was drawn as a development guide for the industry.

  8. The automotive transmission book

    CERN Document Server

    Fischer, Robert; Jürgens, Gunter; Najork, Rolf; Pollak, Burkhard

    2015-01-01

    This book presents essential information on systems and interactions in automotive transmission technology and outlines the methodologies used to analyze and develop transmission concepts and designs. Functions of and interactions between components and subassemblies of transmissions are introduced, providing a basis for designing transmission systems and for determining their potentials and properties in vehicle-specific applications: passenger cars, trucks, buses, tractors, and motorcycles. With these fundamentals the presentation provides universal resources for both state-of-the-art and future transmission technologies, including systems for electric and hybrid electric vehicles.

  9. Novel mechanism of regulation of the DNA repair enzyme OGG1 in tuberin-deficient cells

    Science.gov (United States)

    Habib, Samy L.; Bhandari, Besant K.; Sadek, Nahed; Abboud-Werner, Sherry L.; Abboud, Hanna E.

    2010-01-01

    Tuberin (protein encodes by tuberous sclerosis complex 2, Tsc2) deficiency is associated with the decrease in the DNA repair enzyme 8-oxoG-DNA glycosylase (OGG1) in tumour kidney of tuberous sclerosis complex (TSC) patients. The purpose of this study was to elucidate the mechanisms by which tuberin regulates OGG1. The partial deficiency in tuberin expression that occurs in the renal proximal tubular cells and kidney cortex of the Eker rat is associated with decreased activator protein 4 (AP4) and OGG1 expression. A complete deficiency in tuberin is associated with loss of AP4 and OGG1 expression in kidney tumour from Eker rats and the accumulation of significant levels of 8-oxo-deoxyguanosine. Knockdown of tuberin expression in human renal epithelial cells (HEK293) with small interfering RNA (siRNA) also resulted in a marked decrease in the expression of AP4 and OGG1. In contrast, overexpression of tuberin in HEK293 cells increased the expression of AP4 and OGG1 proteins. Downregulation of AP4 expression using siRNA resulted in a significant decrease in the protein expression of OGG1. Immunoprecipitation studies show that AP4 is associated with tuberin in cells. Gel shift analysis and chromatin immunoprecipitation identified the transcription factor AP4 as a positive regulator of the OGG1 promoter. AP4 DNA-binding activity is significantly reduced in Tsc2−/− as compared with Tsc2+/+ cells. Transcriptional activity of the OGG1 promoter is also decreased in tuberin-null cells compared with wild-type cells. These data indicate a novel role for tuberin in the regulation of OGG1 through the transcription factor AP4. This regulation may be important in the pathogenesis of kidney tumours in patients with TSC disease. PMID:20837600

  10. Motorcycle Repair.

    Science.gov (United States)

    Hein, Jim; Bundy, Mike

    This motorcycle repair curriculum guide contains the following ten areas of study: brake systems, clutches, constant mesh transmissions, final drives, suspension, mechanical starting mechanisms, electrical systems, fuel systems, lubrication systems, and overhead camshafts. Each area consists of one or more units of instruction. Each instructional…

  11. INTEGRATED AUTOMOTIVE MANUFACTURING SUPPLY

    Directory of Open Access Journals (Sweden)

    P.J.S. Van Dyk

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Supply planning and traffic flow planning are major activities in the automotive manufacturing environment worldwide. Traditionally, the impact of supply planning strategies on plant traffic is rarely considered. This paper describes the development of a Decision Support System (DSS that will assist automotive manufacturers to analyse the effect of supply planning decisions on plant traffic during the supply planning phase of their logistics planning process. In essence, this DSS consists of a Supply Medium Decision Support Tool (SMDST (an interactive MS-Excel model with Visual Basic interfacing and a traffic flow simulation model tool (using eMPlant simulation software.

    AFRIKAANSE OPSOMMING: Verskaffingsbeplanning en verkeersvloeibeplanning is belangrike aktiwiteite in die motorvervaardigingsbedryf wêreldwyd. Tradisioneel word die uitwerking van verskaffings-beplanningsstrategië op aanlegverkeer selde in ag geneem. Hierdie artikel beskryf die ontwikkeling van ’n Besluitnemings Ondersteuningstelsel (DSS wat motorvervaardigers sal ondersteun in die analise van die effek van verskaffingsbeplanningbesluite op aanlegverkeer tydens die verskaffingsbeplanningsfase van hulle logistieke beplanningsproses. Hierdie DSS bestaan hoofsaaklik uit ’n Verskaffings-vervoermiddel Besluitnemingshulpmiddel (SMDST (’n interaktiewe MS-Excel model met “Visual Basic” koppelling asook ’n simulasiemodel van verkeersvloei (met eM-Plant simulasiesagteware.

  12. Approach to the classical radiation biology. Ionizing radiation effects and repair mechanism of DNA double strand breaks

    Energy Technology Data Exchange (ETDEWEB)

    Utsumi, Hiroshi [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst

    2000-09-01

    Split-dose recovery has been observed under a variety of experimental conditions in many cell systems and believed to be the recovery of sublethal damage (SLD). It is considered to be one of the most widespread and important cellular responses in clinical radiotherapy. To study the molecular mechanism of this recovery, we analyzed the knockout mutants KU70{sup -/-}, RAD54{sup -/-}, and KU70{sup -/-}/ RAD54{sup -/-} of the chicken B-cell line, DT40. Rad54 participates in the homologous recombinational (HR) repair of DNA double-strand breaks (DSB), while Ku proteins are involved in non-homologous end-joining (NHEJ). Split-dose recovery was observed in the parent DT40 and KU70{sup -/-} cells. Moreover the split-dose survival enhancement had all of the characteristics of SLD recovery that had been demonstrated earlier: e.g., the reappearance of the shoulder of the survival curve with dose fractionation; repair at 25degC; and inhibition by the antibiotic actinomycin D. These results strongly suggest that SLD recovery is due to DSB repair via or mediated by HR, and that these breaks constitute SLD. The tonicity-sensitive potentially lethal damage (PLD) recovery was also found only in DT40 and KU70 {sup -/-} cells. Delayed-plating PLD recovery may be controlled by NHEJ repair that works through the cell cycle. These results lead to the conclusion that the repair of DSBs could explain the classical operational recovery phenomena. We have also investigated RBE/LET using those mutants. (author)

  13. Is the Dresden technique a mechanical design of choice suitable for the repair of middle third Achilles tendon ruptures? A biomechanical study.

    Science.gov (United States)

    de la Fuente, C; Carreño-Zillmann, G; Marambio, H; Henríquez, H

    2016-01-01

    To compare the mechanical failure of the Dresden technique for Achilles tendon repair with the double modified Kessler technique controlled repair technique. The maximum resistance of the two repair techniques are also compared. A total of 30 Achilles tendon ruptures in bovine specimens were repaired with an Ethibond(®) suture to 4.5cm from the calcaneal insertion. Each rupture was randomly distributed into one of two surgical groups. After repair, each specimen was subjected to a maximum traction test. The mechanical failure (tendon, suture, or knot) rates (proportions) were compared using the exact Fisher test (α=.05), and the maximum resistances using the Student t test (α=.05). There was a difference in the proportions of mechanical failures, with the most frequent being a tendon tear in the Dresden technique, and a rupture of the suture in the Kessler technique. The repair using the Dresden technique performed in the open mode, compared to the Kessler technique, has a more suitable mechanical design for the repair of middle third Achilles tendon ruptures on developing a higher tensile resistance in 58.7%. However, its most common mechanical failure was a tendon tear, which due to inappropriate loads could lead to lengthening of the Achilles tendon. Copyright © 2016 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Polymer matrix nanocomposites for automotive structural components

    Science.gov (United States)

    Naskar, Amit K.; Keum, Jong K.; Boeman, Raymond G.

    2016-12-01

    Over the past several decades, the automotive industry has expended significant effort to develop lightweight parts from new easy-to-process polymeric nanocomposites. These materials have been particularly attractive because they can increase fuel efficiency and reduce greenhouse gas emissions. However, attempts to reinforce soft matrices by nanoscale reinforcing agents at commercially deployable scales have been only sporadically successful to date. This situation is due primarily to the lack of fundamental understanding of how multiscale interfacial interactions and the resultant structures affect the properties of polymer nanocomposites. In this Perspective, we critically evaluate the state of the art in the field and propose a possible path that may help to overcome these barriers. Only once we achieve a deeper understanding of the structure-properties relationship of polymer matrix nanocomposites will we be able to develop novel structural nanocomposites with enhanced mechanical properties for automotive applications.

  15. Springback prediction of TWIP automotive sheets

    Science.gov (United States)

    Ahn, Kanghwan; Yoo, Donghoon; Seo, Min Hong; Park, Sung-Ho; Chung, Kwansoo

    2009-08-01

    In an effort to reduce the weight of vehicles, automotive companies are replacing conventional steel parts with light weight alloys and/or with advanced high strength steels (AHSS) such as dual-phase (DP), twinning induced plasticity (TWIP), and transformation induced plasticity (TRIP) steels. The main objective of this work is to experimentally and numerically evaluate the macro-performance of the automotive TWIP sheet in conjunction with springback. In order to characterize the mechanical properties, simple tension and tension-compression tests were performed to determine anisotropic properties, as well as the Bauschinger, transient, and permanent softening behaviors during reverse loading. For numerical simulations, the anisotropic yield function Yld2000-2d was utilized along with the combined isotropic-kinematic hardening law based on the modified Chaboche model. Springback verification was performed for the unconstrained cylindrical bending and 2D draw bending tests.

  16. Polymer matrix nanocomposites for automotive structural components.

    Science.gov (United States)

    Naskar, Amit K; Keum, Jong K; Boeman, Raymond G

    2016-12-06

    Over the past several decades, the automotive industry has expended significant effort to develop lightweight parts from new easy-to-process polymeric nanocomposites. These materials have been particularly attractive because they can increase fuel efficiency and reduce greenhouse gas emissions. However, attempts to reinforce soft matrices by nanoscale reinforcing agents at commercially deployable scales have been only sporadically successful to date. This situation is due primarily to the lack of fundamental understanding of how multiscale interfacial interactions and the resultant structures affect the properties of polymer nanocomposites. In this Perspective, we critically evaluate the state of the art in the field and propose a possible path that may help to overcome these barriers. Only once we achieve a deeper understanding of the structure-properties relationship of polymer matrix nanocomposites will we be able to develop novel structural nanocomposites with enhanced mechanical properties for automotive applications.

  17. Delayed onset of tricuspid valve flow in repaired tetralogy of Fallot: an additional mechanism of diastolic dysfunction and interventricular dyssynchrony

    Directory of Open Access Journals (Sweden)

    Benson Lee N

    2011-08-01

    Full Text Available Abstract Background Diastolic dysfunction of the right ventricle (RV is common after repair of tetralogy of Fallot. While restrictive physiology in late diastole has been well known, dysfunction in early diastole has not been described. The present study sought to assess the prevalence and mechanism of early diastolic dysfunction of the RV defined as delayed onset of the tricuspid valve (TV flow after TOF repair. Methods The study population consisted of 31 children with repaired TOF (mean age ± SD, 12.3 ± 4.1 years who underwent postoperative cardiovascular magnetic resonance (CMR. The CMR protocol included simultaneous phase-contrast velocity mapping of the atrioventricular valves, which enabled direct comparison of the timing and patterns of tricuspid (TV and mitral (MV valve flow. The TV flow was defined to have delayed onset when its onset was > 20 ms later than the onset of the MV flow. The TV and MV flow from 14 normal children was used for comparison. The CMR results were correlated with the findings on echocardiography and electrocardiography. Result Delayed onset of the TV flow was observed in 16/31 patients and in none of the controls. The mean delay time was 64.81 ± 27.07 ms (8.7 ± 3.2% of R-R interval. The delay time correlated with the differences in duration of the TV and MV flow (55.94 ± 32.88 ms (r = 0.90, p Conclusions Early diastolic dysfunction with delayed onset of TV flow is common after TOF repair, and is associated with reduced RV ejection fraction. It is a further manifestation of interventricular dyssynchrony and represent an additional mechanism of ventricular diastolic dysfunction.

  18. Outer organic layer and internal repair mechanism protects pteropod Limacina helicina from ocean acidification

    Science.gov (United States)

    Peck, Victoria L.; Tarling, Geraint A.; Manno, Clara; Harper, Elizabeth M.; Tynan, Eithne

    2016-05-01

    Scarred shells of polar pteropod Limacina helicina collected from the Greenland Sea in June 2012 reveal a history of damage, most likely failed predation, in earlier life stages. Evidence of shell fracture and subsequent re-growth is commonly observed in specimens recovered from the sub-Arctic and further afield. However, at one site within sea-ice on the Greenland shelf, shells that had been subject to mechanical damage were also found to exhibit considerable dissolution. It was evident that shell dissolution was localised to areas where the organic, periostracal sheet that covers the outer shell had been damaged at some earlier stage during the animal's life. Where the periostracum remained intact, the shell appeared pristine with no sign of dissolution. Specimens which appeared to be pristine following collection were incubated for four days. Scarring of shells that received periostracal damage during collection only became evident in specimens that were incubated in waters undersaturated with respect to aragonite, ΩAr≤1. While the waters from which the damaged specimens were collected at the Greenland Sea sea-ice margin were not ΩAr≤1, the water column did exhibit the lowest ΩAr values observed in the Greenland and Barents Seas, and was likely to have approached ΩAr≤1 during the winter months. We demonstrate that L. helicina shells are only susceptible to dissolution where both the periostracum has been breached and the aragonite beneath the breach is exposed to waters of ΩAr≤1. Exposure of multiple layers of aragonite in areas of deep dissolution indicate that, as with many molluscs, L. helicina is able to patch up dissolution damage to the shell by secreting additional aragonite internally and maintain their shell. We conclude that, unless breached, the periostracum provides an effective shield for pteropod shells against dissolution in waters ΩAr≤1, and when dissolution does occur the animal has an effective means of self-repair. We suggest

  19. Pension helpdesk calls : A repair mechanism in the client communication of financial institutions

    NARCIS (Netherlands)

    Nell, Louise; Lentz, Leo; Pander Maat, Henk; Koole, Tom

    2015-01-01

    This paper analyzes the role of helpdesk calls in the client communication package of pension funds.Our audio-corpus of 77 helpdesk calls contained 104 client questions. These show that clients seem tocall the helpdesk in order to repair a comprehension problem, to find specific information they mis

  20. Mechanisms and consequences of injury and repair in older organ transplants

    NARCIS (Netherlands)

    B.R. Slegtenhorst (Bendix); F.J.M.F. Dor (Frank); A. Elkhal (Abdala); H. Rodriguez (Hector); X. Yang (Xiaoyong); K. Edtinger (Karoline); R. Quante (Rainer); A.S. Chong (Anita); S.G. Tullius (Stefan)

    2014-01-01

    textabstractDonor organ scarcity remains a significant clinical challenge in transplantation. Older organs, increasingly utilized to meet the growing demand for donor organs, have been linked to inferior transplant outcomes. Susceptibility to organ injury, reduced repair capacity, and increased immu

  1. Dss1 interaction with Brh2 as a regulatory mechanism for recombinational repair

    DEFF Research Database (Denmark)

    Zhou, Qingwen; Kojic, Milorad; Cao, Zhimin;

    2007-01-01

    Brh2, the BRCA2 ortholog in Ustilago maydis, enables recombinational repair of DNA by controlling Rad51 and is in turn regulated by Dss1. Interplay with Rad51 is conducted via the BRC element located in the N-terminal region of the protein and through an unrelated domain, CRE, at the C terminus...

  2. Poly(lactic-co-glycolic acid) conduit for repair of injured sciatic nerve A mechanical analysis*

    Institute of Scientific and Technical Information of China (English)

    Tao Yu; Changfu Zhao; Peng Li; Guangyao Liu; Min Luo

    2013-01-01

    Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) conduit transplantation and autogenous nerve grafting for sciatic nerve injury. This study col ected the sciatic nerve from the gluteus maximus muscle from fresh human cadaver, and established 10-mm-long sciatic nerve injury models by removing the ischium, fol owing which poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts were transplanted. Scanning electron microscopy revealed that the axon and myelin sheath were torn, and the vessels of basilar membrane were obstructed in the poly(lactic-co-glycolic acid) con-duit-repaired sciatic nerve fol owing tensile testing. There were no significant differences in tensile tests with autogenous nerve graft-repaired sciatic nerve. Fol owing poly(lactic-co-glycolic acid) conduit transplantation for sciatic nerve repair, tensile test results suggest that maximum tensile load, maximum stress, elastic limit load and elastic limit stress increased compared with autogen-ous nerve grafts, but elastic limit strain and maximum strain decreased. Moreover, the tendencies of stress-strain curves of sciatic nerves were similar after transplantation of poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts. Results showed that after transplantation in vitro for sciatic nerve injury, poly(lactic-co-glycolic acid) conduits exhibited good intensity, elasticity and plasticity, indicating that poly(lactic-co-glycolic acid) conduits are suitable for sciatic nerve injury repair.

  3. Mechanical restoration and failure analyses of a hydrogel and scaffold composite strategy for annulus fibrosus repair

    NARCIS (Netherlands)

    Long, Rose G.; Buerki, Alexander; Zysset, Philippe; Eglin, David; Grijpma, Dirk W.; Blanquer, Sebastien B. G.; Hecht, Andrew C.; Iatridis, James C.

    2016-01-01

    Unrepaired defects in the annulus fibrosus of intervertebral disks are associated with degeneration and persistent back pain. A clinical need exists for a disk repair strategy that can seal annular defects, be easily delivered during surgical procedures, and restore biomechanics with low risk of her

  4. Poly(lactic-co-glycolic acid) conduit for repair of injured sciatic nerve: A mechanical analysis.

    Science.gov (United States)

    Yu, Tao; Zhao, Changfu; Li, Peng; Liu, Guangyao; Luo, Min

    2013-07-25

    Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) conduit transplantation and autogenous nerve grafting for sciatic nerve injury. This study collected the sciatic nerve from the gluteus maximus muscle from fresh human cadaver, and established 10-mm-long sciatic nerve injury models by removing the ischium, following which poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts were transplanted. Scanning electron microscopy revealed that the axon and myelin sheath were torn, and the vessels of basilar membrane were obstructed in the poly(lactic-co-glycolic acid) conduit-repaired sciatic nerve following tensile testing. There were no significant differences in tensile tests with autogenous nerve graft-repaired sciatic nerve. Following poly(lactic-co-glycolic acid) conduit transplantation for sciatic nerve repair, tensile test results suggest that maximum tensile load, maximum stress, elastic limit load and elastic limit stress increased compared with autogenous nerve grafts, but elastic limit strain and maximum strain decreased. Moreover, the tendencies of stress-strain curves of sciatic nerves were similar after transplantation of poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts. Results showed that after transplantation in vitro for sciatic nerve injury, poly(lactic-co-glycolic acid) conduits exhibited good intensity, elasticity and plasticity, indicating that poly(lactic-co-glycolic acid) conduits are suitable for sciatic nerve injury repair.

  5. Asymmetric and Nonlinear Impact of Attribute-Level Performance on Overall Customer Satisfaction in the Context of Car Servicing of Four European Automotive Brands in Slovenia

    National Research Council Canada - National Science Library

    Ažman, Slavko; Gomišček, Boštjan

    2012-01-01

    .... The data set that was analysed was acquired from a regular survey on customer satisfaction with vehicle repair and maintenance services of four European automotive brands in Slovenia, carried out...

  6. Transcription-coupled nucleotide excision repair in mammalian cells: molecular mechanisms and biological effects

    Institute of Scientific and Technical Information of China (English)

    Mafia Fousteri; Leon HF Mullenders

    2008-01-01

    The encounter of elongating RNA polymerase Ⅱ (RNAPIIo) with DNA lesions has severe consequences for the cell as this event provides a strong signal for P53-dependent apoptosis and cell cycle arrest. To counteract prolonged blockage of transcription, the cell removes the RNAPllo-hlocking DNA lesions by transcription-coupled repair (TC-NER), a specialized subpathway of nucleotide excision repair (NER). Exposure of mice to UVB light or chemicals has elucidated that TC-NER is a critical survival pathway protecting against acute toxic and long-term effects (cancer) of genotoxic exposure. Deficiency in TC-NER is associated with mutations in the CSA and CSB genes giving rise to the rare hu-man disorder Cockayne syndrome (CS). Recent data suggest that CSA and CSB play differential roles in mammalian TC-NER: CSB as a repair coupling factor to attract NER proteins, chromatin remodellers and the CSA- E3-ubiquitin iigase complex to the stalled RNAPI io. CSA is dispensable for attraction of NER proteins, yet in cooperation with CSB is required to recruit XAB2, the nucleosomal binding protein HMGNl and TFIIS. The emerging picture of TC-NER is complex: repair of transcription-blocking lesions occurs without displacement of the DNA damage-stalled RNAPIIo, and requires at least two essential assembly factors (CSA and CSB), the core NER factors (except for XPC-RAD23B), and TC-NER specific factors. These and yet unidentified proteins will accomplish not only efficient repair of transcrip-tion-blocking lesions, but are also likely to contribute to DNA damage signalling events.

  7. Tank-automotive robotics

    Science.gov (United States)

    Lane, Gerald R.

    1999-07-01

    To provide an overview of Tank-Automotive Robotics. The briefing will contain program overviews & inter-relationships and technology challenges of TARDEC managed unmanned and robotic ground vehicle programs. Specific emphasis will focus on technology developments/approaches to achieve semi- autonomous operation and inherent chassis mobility features. Programs to be discussed include: DemoIII Experimental Unmanned Vehicle (XUV), Tactical Mobile Robotics (TMR), Intelligent Mobility, Commanders Driver Testbed, Collision Avoidance, International Ground Robotics Competition (ICGRC). Specifically, the paper will discuss unique exterior/outdoor challenges facing the IGRC competing teams and the synergy created between the IGRC and ongoing DoD semi-autonomous Unmanned Ground Vehicle and DoT Intelligent Transportation System programs. Sensor and chassis approaches to meet the IGRC challenges and obstacles will be shown and discussed. Shortfalls in performance to meet the IGRC challenges will be identified.

  8. Effect of different mechanical and chemical surface treatments on the repaired bond strength of an indirect composite resin.

    Science.gov (United States)

    Kimyai, Soodabeh; Oskoee, Siavash Savadi; Mohammadi, Narmin; Rikhtegaran, Sahand; Bahari, Mahmoud; Oskoee, Parnian Alizadeh; Vahedpour, Hafez

    2015-02-01

    This study compared the effects of two mechanical surface preparation techniques, air abrasion and Nd:YAG laser, with the use of two adhesive systems, self-etch and etch and rinse, on the repair bond strengths of an indirect composite resin. One hundred fifty cylindrical samples of an indirect composite resin were prepared and randomly divided into six groups (n = 25). In groups 1-3, the composite resin surfaces were respectively prepared as follows: no roughening, roughening by air abrasion, and roughening by Nd:YAG laser, followed by application of an etch-and-rinse adhesive. In groups 4-6, the preparation techniques were respectively the same as those in groups 1-3, followed by application of a self-etch adhesive. Subsequently, a direct composite resin was added and repair bond strengths were measured. Data were analyzed with two-way ANOVA and post hoc Tukey's test. Mean bond strength value was significant based on the preparation technique (P composite resin with air abrasion and Nd:YAG laser resulted in a significant increase in the repair bond strength, with air abrasion being more effective. There were no significant differences in bond strength between the two adhesives.

  9. Mechanisms of DNA repair and radio-induced mutagenesis in higher eukaryotes; Mecanismes de reparation et mutagenese radio-induite chez les eucaryotes superieurs

    Energy Technology Data Exchange (ETDEWEB)

    Averbeck, D. [Centre Universitaire d' Orsay, Institut Curie, Section de Recherche, Lab. Raymond-Latarjet, UMR 2027 CNRS, 91 (France)

    2000-10-01

    Cells of higher eukaryotes possess several very efficient systems for the repair of radiation-induced lesions in DNA. Different strategies have been adopted at the cellular level to remove or even tolerate various types of lesions in order to assure survival and limit the mutagenic consequences. In mammalian cells, the main DNA repair systems comprise direct reversion of damage, excision of damage and exchange mechanisms with intact DNA. Among these, the direct ligation of single strand breaks (SSB) by a DNA ligase and the multi-enzymatic repair systems of mismatch repair, base and nucleotide excision repair as well as the repair of double strand breaks (DSB) by homologous recombination or non homologous end-joining are the most important systems. Most of these processes are error-free except the non homologous end-joining pathway used for the repair of DSB. Moreover, certain lesions can be tolerated by more or less accurately acting polymerases capable of performing trans-lesion DNA syntheses. The DNA repair systems are intimately integrated in the network of cellular regulation. Some of their components are DNA damage inducible. Radiation-induced mutagenesis is largely due to unrepaired DNA damage but also involves error-prone repair processes like the repair of DSB by non-homologous end-joining. Generally, mammalian cells are well prepared to repair radiation-induced lesions. However, some questions remain to be asked about mechanistic details and efficiencies of the systems for removing certain types of radiation-damage and about their order and timing of action. The answers to these questions would be important for radioprotection as well as radiotherapy. (author)

  10. The green microalga Tetraselmis suecica reduces oxidative stress and induces repairing mechanisms in human cells

    Science.gov (United States)

    Sansone, Clementina; Galasso, Christian; Orefice, Ida; Nuzzo, Genoveffa; Luongo, Elvira; Cutignano, Adele; Romano, Giovanna; Brunet, Christophe; Fontana, Angelo; Esposito, Francesco; Ianora, Adrianna

    2017-01-01

    Green microalgae contain many active pigments such as carotenoids having antioxidant and protective activity on human cells. Here we investigate the biological activity of an ethanol/water extract of the marine green microalga Tetraselmis suecica containing high levels of carotenoids such as the xanthophylls lutein, violaxanthin, neoxanthin, antheraxanthin and loroxanthin esters. This extract has a strong antioxidant and repairing activity in the human lung cancer cell line (A549) as shown by the increased expression of dehydrocholesterol reductase-24 (DHCR24) and prostaglandin reductase 1 (PTGR1) genes and proteins. The extract also reduces prostaglandin E2 (PGE2) levels in cells damaged by H2O2 and has tissue repairing effects on reconstructed human epidermal tissue cells (EpiDermTM) indicating a potential cosmeceutical activity of this microalgal species. PMID:28117410

  11. Arsenic Biotransformation as a Cancer Promoting Factor by Inducing DNA Damage and Disruption of Repair Mechanisms

    Directory of Open Access Journals (Sweden)

    Victor D. Martinez

    2011-01-01

    Full Text Available Chronic exposure to arsenic in drinking water poses a major global health concern. Populations exposed to high concentrations of arsenic-contaminated drinking water suffer serious health consequences, including alarming cancer incidence and death rates. Arsenic is biotransformed through sequential addition of methyl groups, acquired from s-adenosylmethionine (SAM. Metabolism of arsenic generates a variety of genotoxic and cytotoxic species, damaging DNA directly and indirectly, through the generation of reactive oxidative species and induction of DNA adducts, strand breaks and cross links, and inhibition of the DNA repair process itself. Since SAM is the methyl group donor used by DNA methyltransferases to maintain normal epigenetic patterns in all human cells, arsenic is also postulated to affect maintenance of normal DNA methylation patterns, chromatin structure, and genomic stability. The biological processes underlying the cancer promoting factors of arsenic metabolism, related to DNA damage and repair, will be discussed here.

  12. A fracture mechanics analysis of bonded repaired skin/stiffener structures with inclined central crack

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Ki Hyun; Yang, Won Ho; Kim, Cheol; Heo, Sung Pil [Sungkyunkwan Univ., Seoul (Korea, Republic of); Ko, Myung Hoon [Daelim College, Anyang (Korea, Republic of)

    2001-07-01

    Composite patch repair of cracked aircraft structures has been accepted as one of improving fatigue life and attaining better structural integrity. Analysis for the stress intensity factor at the skin/stiffener structure with inclined central crack repaired by composite stiffened panels are developed. A numerical investigation was conducted to characterize the fracture behavior and crack growth behavior. In order to investigate the crack growth direction, Maximum Tangential Stress(MTS) criteria is used. The main objective of this research is the validation of the inclined crack patching design. In this paper, the reduction of stresses intensity factors at the crack-tip and prediction of crack growth direction are determined to evaluate the effects of various non-dimensional design parameter including; composite patch thickness and stiffener distance. The research on cracked structure subjected to mixed mode loading is accomplished and it is evident that more work using different approaches is necessary.

  13. The green microalga Tetraselmis suecica reduces oxidative stress and induces repairing mechanisms in human cells.

    Science.gov (United States)

    Sansone, Clementina; Galasso, Christian; Orefice, Ida; Nuzzo, Genoveffa; Luongo, Elvira; Cutignano, Adele; Romano, Giovanna; Brunet, Christophe; Fontana, Angelo; Esposito, Francesco; Ianora, Adrianna

    2017-01-24

    Green microalgae contain many active pigments such as carotenoids having antioxidant and protective activity on human cells. Here we investigate the biological activity of an ethanol/water extract of the marine green microalga Tetraselmis suecica containing high levels of carotenoids such as the xanthophylls lutein, violaxanthin, neoxanthin, antheraxanthin and loroxanthin esters. This extract has a strong antioxidant and repairing activity in the human lung cancer cell line (A549) as shown by the increased expression of dehydrocholesterol reductase-24 (DHCR24) and prostaglandin reductase 1 (PTGR1) genes and proteins. The extract also reduces prostaglandin E2 (PGE2) levels in cells damaged by H2O2 and has tissue repairing effects on reconstructed human epidermal tissue cells (EpiDerm(TM)) indicating a potential cosmeceutical activity of this microalgal species.

  14. Regulation of DNA repair mechanism in human glioma xenograft cells both in vitro and in vivo in nude mice.

    Directory of Open Access Journals (Sweden)

    Shivani Ponnala

    Full Text Available BACKGROUND: Glioblastoma Multiforme (GBM is the most lethal form of brain tumor. Efficient DNA repair and anti-apoptotic mechanisms are making glioma treatment difficult. Proteases such as MMP9, cathepsin B and urokinase plasminogen activator receptor (uPAR are over expressed in gliomas and contribute to enhanced cancer cell proliferation. Non-homologous end joining (NHEJ repair mechanism plays a major role in double strand break (DSB repair in mammalian cells. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that silencing MMP9 in combination with uPAR/cathepsin B effects NHEJ repair machinery. Expression of DNA PKcs and Ku70/80 at both mRNA and protein levels in MMP9-uPAR (pMU and MMP9-cathepsin B (pMC shRNA-treated glioma xenograft cells were reduced. FACS analysis showed an increase in apoptotic peak and proliferation assays revealed a significant reduction in the cell population in pMU- and pMC-treated cells compared to untreated cells. We hypothesized that reduced NHEJ repair led to DSBs accumulation in pMU- and pMC-treated cells, thereby initiating cell death. This hypothesis was confirmed by reduced Ku70/Ku80 protein binding to DSB, increased comet tail length and elevated γH2AX expression in treated cells compared to control. Immunoprecipitation analysis showed that EGFR-mediated lowered DNA PK activity in treated cells compared to controls. Treatment with pMU and pMC shRNA reduced the expression of DNA PKcs and ATM, and elevated γH2AX levels in xenograft implanted nude mice. Glioma cells exposed to hypoxia and irradiation showed DSB accumulation and apoptosis after pMU and pMC treatments compared to respective controls. CONCLUSION/SIGNIFICANCE: Our results suggest that pMU and pMC shRNA reduce glioma proliferation by DSB accumulation and increase apoptosis under normoxia, hypoxia and in combination with irradiation. Considering the radio- and chemo-resistant cancers favored by hypoxia, our study provides important therapeutic potential

  15. The interplay among chromatin dynamics, cell cycle checkpoints and repair mechanisms modulates the cellular response to DNA damage.

    Science.gov (United States)

    Lazzaro, Federico; Giannattasio, Michele; Muzi-Falconi, Marco; Plevani, Paolo

    2007-06-01

    Cells are continuously under the assault of endogenous and exogenous genotoxic stress that challenges the integrity of DNA. To cope with such a formidable task cells have evolved surveillance mechanisms, known as checkpoints, and a variety of DNA repair systems responding to different types of DNA lesions. These lesions occur in the context of the chromatin structure and, as expected for all DNA transactions, the cellular response to DNA damage is going to be influenced by the chromatin enviroment. In this review, we will discuss recent studies implicating chromatin remodelling factors and histone modifications in the response to DNA double-strand breaks (DSBs) and in checkpoint activation in response to UV lesions.

  16. Dynamics and mechanism of UV-damaged DNA repair in indole-thymine dimer adduct: molecular origin of low repair quantum efficiency.

    Science.gov (United States)

    Guo, Xunmin; Liu, Zheyun; Song, Qinhua; Wang, Lijuan; Zhong, Dongping

    2015-02-26

    Many biomimetic chemical systems for repair of UV-damaged DNA showed very low repair efficiency, and the molecular origin is still unknown. Here, we report our systematic characterization of the repair dynamics of a model compound of indole-thymine dimer adduct in three solvents with different polarity. By resolving all elementary steps including three electron-transfer processes and two bond-breaking and bond-formation dynamics with femtosecond resolution, we observed the slow electron injection in 580 ps in water, 4 ns in acetonitrile, and 1.38 ns in dioxane, the fast back electron transfer without repair in 120, 150, and 180 ps, and the slow bond splitting in 550 ps, 1.9 ns, and 4.5 ns, respectively. The dimer bond cleavage is clearly accelerated by the solvent polarity. By comparing with the biological repair machine photolyase with a slow back electron transfer (2.4 ns) and a fast bond cleavage (90 ps), the low repair efficiency in the biomimetic system is mainly determined by the fast back electron transfer and slow bond breakage. We also found that the model system exists in a dynamic heterogeneous C-clamped conformation, leading to a stretched dynamic behavior. In water, we even identified another stacked form with ultrafast cyclic electron transfer, significantly reducing the repair efficiency. Thus, the comparison of the repair efficiency in different solvents is complicated and should be cautious, and only the dynamics by resolving all elementary steps can finally determine the total repair efficiency. Finally, we use the Marcus electron-transfer theory to analyze all electron-transfer reactions and rationalize all observed electron-transfer dynamics.

  17. Characterization of the mechanical properties and structural integrity of T-welded connections repaired by grinding and wet welding

    Energy Technology Data Exchange (ETDEWEB)

    Terán, G., E-mail: gteran@imp.mx [Instituto Mexicano del Petróleo, Eje central Lázaro Cárdenas 152, Col. San Bartolo Atepehuacan, México D.F. CP 07730, México (Mexico); Cuamatzi-Meléndez, R., E-mail: rcuamatzi@imp.mx [Instituto Mexicano del Petróleo, Eje central Lázaro Cárdenas 152, Col. San Bartolo Atepehuacan, México D.F. CP 07730, México (Mexico); Albiter, A., E-mail: aalbiter@imp.mx [Instituto Mexicano del Petróleo, Eje central Lázaro Cárdenas 152, Col. San Bartolo Atepehuacan, México D.F. CP 07730, México (Mexico); Maldonado, C., E-mail: cmzepeda@umich.mx [Instituto de Investigaciones Metalúrgicas, UMSNH, PO Box 52-B, 58000, México (Mexico); Bracarense, A.Q., E-mail: bracarense@ufmg.br [UFMG Departamento de Engeharia Mecánica Belo Horizonte, MG (Brazil)

    2014-04-01

    This paper presents an experimental methodology to characterize the structural integrity and mechanical properties of repaired T-welded connections using in fixed offshore structures. Grinding is employed to remove localized damage like cracking and corrosion and subsequent wet welding can be used to fill the grinded material. But it is important to define the grinding depth and profile in order to maintain structural integrity during the repair. Therefore, in this work different grinding depths were performed, for damage material removal, at the weld toe of the T-welded connections. The grinding was filled by wet welding in a hyperbaric chamber, simulating three different water depths: 50 m, 70 m and 100 m. The electrodes were coated with vinilic varnish, which is cheap and easy to apply. The characterization of the mechanical properties of the T-welded connections was done with standard tensile, hardness and Charpy tests; microstructure and porosity analysis were also performed. The samples were obtained from the welded connections in regions of the wet weld beads. The test results were compared with the mechanical properties of the T-welded connections welded in air conditions performed by other authors. The results showed that the wet welding technique performed in this work produced good mechanical properties of the repaired T-welded connection. The mechanical properties, measured in wet conditions, for 6 mm grinding depth, were similar for the 3 different water depths measured in air conditions. But for 10 mm grinding depth, the values of the mechanical properties measured in wet conditions were quite lower than that for air conditions for the 3 water depths. However a porosity analysis, performed with a Scanning Electronic Microscopy (SEM), showed that the level of porosity in the resulted wet weld beads is in the range of that published in the literature and some samples revealed lower level of porosity. The main resulting microstructure was polygonal

  18. Bacterial radiosensitivity to gamma and ultraviolet. Compositional dependence and repair mechanisms; Radiosensibilidad bacteriana frente a gamma y ultravioleta. Dependencia composicional y mecanismos de reparacion

    Energy Technology Data Exchange (ETDEWEB)

    Saez Angulo, R. M.; Davila, C. A.

    1974-07-01

    The gamma and ultraviolet radiosensitivity of several species of bacteria has been determined its dependence on DNAs composition and repair processes has been studied. Base composition are evaluated by chromatography, DNA melting temperature and isopycnic sedimentation on CsCl gradient. Repair capacity of gamma -and UV- lesions has been studied in two bacterial strains with same DMA base composition. It is concluded that the postulated correlation between radiosensitivity and base composition can not be generalized, the enzymatic repair mechanisms being of determining on radiosensitivity. (Author) 248 refs.

  19. ENVIRONMENTAL ASSESSMENT OF SHOP TOWEL USAGE IN THE AUTOMOTIVE AND PRINTING INDUSTRIES

    Science.gov (United States)

    This assessment identifies the environmental impacts and usage trends of shop towels in the printing and automotive repair industries. The shop towels are used to clean equipment and to wipe up contaminants for a variety of operations. Four types of shop towels were evaluated; wo...

  20. Automotive Service Technician: Apprenticeship Course Outline. Apprenticeship and Industry Training. 0912

    Science.gov (United States)

    Alberta Advanced Education and Technology, 2012

    2012-01-01

    The graduate of the Automotive Service Technician apprenticeship program is a certified journeyperson who will be able to: (1) repair, maintain and overhaul or modify a motor vehicle; (2) comprehend work orders, technical bulletins and estimates, and relate the information to the job at hand; (3) interpret warranty policy in terms of service…

  1. ENVIRONMENTAL ASSESSMENT OF SHOP TOWEL USAGE IN THE AUTOMOTIVE AND PRINTING INDUSTRIES

    Science.gov (United States)

    This assessment identifies the environmental impacts and usage trends of shop towels in the printing and automotive repair industries. The shop towels are used to clean equipment and to wipe up contaminants for a variety of operations. Four types of shop towels were evaluated; wo...

  2. Preparation, bioactivity and mechanism of nano-hydroxyapatite/sodium alginate/chitosan bone repair material.

    Science.gov (United States)

    Liao, Jianguo; Li, Yanqun; Li, Haiyan; Liu, Jingxian; Xie, Yufen; Wang, Jianping; Zhang, Yongxiang

    2017-08-11

    As the major inorganic component of natural bone, nano-hydroxyapatite (n-HA) on its own is limited in its use in bone repair, due to its brittleness. Chitosan (CS) and sodium alginate (SAL) are used to reduce its brittleness and tendency to degradation. However, the compressive strength of the composite is still low, and its biological performance needs further study. Nano-hydroxyapatite/sodium alginate/chitosan (n-HA/SAL/CS) composite was prepared via an in situ synthesis method. Further, we prepared the n-HA/SAL/CS self-setting bone repair material by mixing n-HA/SAL/CS powder with a curing liquid (20 wt.% citric acid). In addition, the in vitro bioactivity and cell cytotoxicity were also explored. Transmission electron microscopy photos revealed that the n-HA crystals were uniformly distributed throughout the polymer matrix. Infrared IR spectroscopy indicated that the HA interacted with the COO- of SAL and NH2- of CS. The compressive strength of the n-HA/SAL/CS bone cement was 34.3 MPa and matched the demands of weight-bearing bones. Soaking in vitro in simulated body fluid demonstrated that the composite material had reasonably good bioactivity, while cytotoxicity tests indicated that the n-HA/SAL/CS cement could promote cell proliferation and was biocompatible. Compressive strength of n-HA/SAL/CS can satisfy the needs of cancellous bone, and in vitro bioactivity and cytotoxicity tests results indicated that the n-HA/SAL/CS composite could act as an optimal bone repair material.

  3. Automotive powerplant evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Stamper, K.R.

    1976-06-01

    A program to obtain automotive engine performance data for use in estimating vehicle emission and fuel economy in varied service and duty is described. An experimental test procedure for generating fuel consumption and emissions data adequate to characterize an engine over its full operating range was developed for steady-state tests. The development of a test procedure for transient testing is currently under way. The steady-state data will be collected from approximately 23 different engines, including: (1) 16 current production spark-ignition engines; (2) 3 pre-production or prototype advanced design spark-ignition engines; and (3) 4 light-duty diesel engines which are, or could be, used in passenger car applications. To date, steady-state ''engine maps'' were completed on 10 engines. A simplified model used to compare steady-state data with chassis dynamometer data indicates that results thus far can be used to obtain estimates of fuel economy in automobiles.

  4. GUIDES TO POLLUTION PREVENTION: THE AUTO REPAIR INDUSTRY

    Science.gov (United States)

    Automotive maintenance and repair shops generate a variety of waste streams during activities such as replacing fluids (e.g., motor oil, radiator coolant, transmission fluid, brake fluid), replacing non-repairable parts (e.g., brake shoes/pads, shocks, batteries, belts, mufflers,...

  5. Escalation Practices in Automotive Development

    Directory of Open Access Journals (Sweden)

    Tomaž Jurejevčič

    2016-12-01

    Full Text Available Research Question (RQ: In automotive business many risk-involved situations occur and when detected, an escalation process takes place. Although defined and controlled by process guidelines and being supported by experts, escalation brings increased emotional pressure and stress for parties involved. Do escalation processes in automotive industry maintain all implied challenges? Purpose: The purpose of the article is to present current status of escalation processes and gaps between theory and practice cases. Results of the analysis are recommendations of good engineering practice derived also from actual experiences and learned lessons. Method: The method involves analysis of practical cases from automotive development process, lessons learned, anonymous survey of automotive engineers and classification of experiences. Results: Results of the survey have shown that the controlled escalation process for know-how related escalations is needed in order to establish the environment where the team is able to provide new, sometimes unconventional ideas for the problem to be solved. Organization: Presented recommendations and measures enable organization and managers to put the expertise and experiences of employees into action for problem solving during escalation. Originality: In this article some practices are presented that, although simple and some yet seen, with proper adjustment stemming from real life processes give a fruitful settlement of escalations in automotive development business.

  6. Divergent impact of Toll-like receptor 2 deficiency on repair mechanisms in healthy muscle versus Duchenne muscular dystrophy.

    Science.gov (United States)

    Mojumdar, Kamalika; Giordano, Christian; Lemaire, Christian; Liang, Feng; Divangahi, Maziar; Qureshi, Salman T; Petrof, Basil J

    2016-05-01

    Injury to skeletal muscle, whether acute or chronic, triggers macrophage-mediated innate immunity in a manner which can be either beneficial or harmful for subsequent repair. Endogenous ligands for Toll-like receptor 2 (TLR2) are released by damaged tissues and might play an important role in activating the innate immune system following muscle injury. To test this hypothesis, we compared macrophage behaviour and muscle repair mechanisms in mice lacking TLR2 under conditions of either acute (cardiotoxin-induced) or chronic (mdx mouse genetic model of Duchenne muscular dystrophy; DMD) muscle damage. In previously healthy muscle subjected to acute damage, TLR2 deficiency reduced macrophage numbers in the muscle post-injury but did not alter the expression pattern of the prototypical macrophage polarization markers iNOS and CD206. In addition, there was abnormal persistence of necrotic fibres and impaired regeneration in TLR2-/- muscles after acute injury. In contrast, TLR2 ablation in chronically diseased muscles of mdx mice not only resulted in significantly reduced macrophage numbers but additionally modified their phenotype by shifting from inflammatory (iNOS(pos) CD206(neg) ) to more anti-inflammatory (iNOS(neg) CD206(pos) ) characteristics. This decrease in macrophage-mediated inflammation was associated with ameliorated muscle histopathology and improved force-generating capacity of the dystrophic muscle. Our results suggest that the role of TLR2 in macrophage function and skeletal muscle repair depends greatly upon the muscle injury context, and raise the possibility that inhibition of TLR2 could serve as a useful therapeutic measure in DMD.

  7. Relationship among the repair mechanisms and the genetic recombination; Relacion entre los mecanismos de reparacion y la recombinacion genetica

    Energy Technology Data Exchange (ETDEWEB)

    Alcantara D, D. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1987-12-15

    In accordance with the previous reports of the Project BZ87 of the Department of Radiobiology, a dependent stimulation of the system exists in E.coli SOS, of the recombination of the bacteriophage Lambda whose genetic material has not been damaged. This stimulation is not due to the increase of the cellular concentration of the protein RecA and the mechanism but probable for which we find that it is carried out, it is through a cooperation among the product of the gene rec N of E. coli and the system Net of recombination of Lambda. The gene recN belongs to the group of genes SOS and its expression is induced when damaging the bacterial DNA where it intervenes in the repair of breaks of the double helix of the molecule (Picksley et, 1984). If the repair of breaks of this type is a factor that limits the speed with which it happens the recombination among viral chromosomes, then the biggest readiness in the protein RecN, due to the induction of the functions SOS, would facilitate the repair of such ruptures. In this new project it is to enlarge the knowledge about this phenomenon, it was, on one hand of corroborating in a way but he/she specifies the relationship between the recombinogenic response of Lambda and the System SOS of E. coli and for the other one to determine the effect that has the inhibition of the duplication of the DNA on the stimulation of the viral recombination. Everything it with the idea of making it but evident and to be able to use it as a system of genotoxic agents detection in E. coli. (Author)

  8. Abstracts of the Conference on Mechanisms of DNA Repair and Mutagenesis on the 100. Anniversary of the Discovery of Polonium and Radium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The conference covered various aspects of mutagenesis and mechanisms of DNA repair. UV and ionizing radiation were use to induce DNA lesions in bacteria, yeast and cell cultures of higher organisms. This allows study of influence of mutations on particular processes in the cell. Mechanisms of resistance were also investigated. Biological investigations were performed using labelled compounds.

  9. [Research on effects of vitamin A palmitate on repair of mechanical corneal epithelial defects and conjunctival goblet cells in rabbits].

    Science.gov (United States)

    Qiu, Xiao-di; Gong, Lan; Chen, Min-jie

    2010-02-01

    Randomized controlled experimental study to investigate the influence of vitamin A palmitate and bovine recombinant basic fibroblast growth factor (bFGF) on repair of mechanical corneal epithelial defects, conjunctival epithelial cells and goblet cells in rabbits. One hundred and twenty New Zealand rabbits (all males) were selected to establish the mechanical corneal epithelial defects models (scratching out a round area with the diameter of 8 mm in the centre of cornea). Forty eight New Zealand rabbits were randomly divided into 4 groups: group A used lincomycin hydrochloride eye drops (LED) after the model had been established; group B used vitamin A palmitate eye gel and LED; group C used recombinant bFGF eye gel and LED; group D used vitamin A palmitate eye gel, bFGF eye gel and LED. Photo slit lamp examination and measurement of repaired area were performed on day 0, day 1, day 4 and day 7; transmission electron microscopy, histological microscope examination and impression cytology were performed on day 0, day 1, day 4 and day 7 to analysis the morphology and repairment of corneal epithelium, conjunctival epithelial cells and the goblet cells. The variants were tested using analysis of variance and Tukey's test. Statistic analysis showed that on day 1, the size of areas of repaired corneal epithelium was: group A(53.512 +/- 18.850) mm(2), group B (92.194 +/- 14.367) mm(2), group C (89.779 +/- 20.535) mm(2), group D (127.816 +/- 16.379) mm(2). The difference in size of repaired areas between different groups was statistically significant (F = 17.663, P = 0.000), with exception of the difference between groups B and C (P = 0.995). Conjunctival impression cytology showed that, the average number of conjunctival goblet cells per 740 microm x 550 microm at day 1 was decreased, group A (10.083 +/- 4.441), group B (10.667 +/- 3.551), group C (9.583 +/- 4.502), group D (9.167 +/- 5.606). The difference between these four groups was not significant (F = 0.239, P = 0

  10. Engineering wear-resistant surfaces in automotive aluminum

    Science.gov (United States)

    Kavorkijan, V.

    2003-02-01

    Inadequate wear resistance and low seizure loads prevent the direct use of aluminum alloys in automotive parts subject to intensive friction combined with high thermal and mechanical loading, such as brake discs, pistons, and cylinder liners. To enable the use of aluminum alloys in the production of automotive brake discs and other wear-resistant products, the insertion of a monolithic friction cladding rather than surface coating has been considered in this work. Three experimental approaches, two based on the pressure-less infiltration of porous ceramic preforms and one based on the subsequent hot rolling of aluminum and metal-matrix composite strips, are currently under investigation.

  11. Constitutional Chromothripsis Rearrangements Involve Clustered Double-Stranded DNA Breaks and Nonhomologous Repair Mechanisms

    Directory of Open Access Journals (Sweden)

    Wigard P. Kloosterman

    2012-06-01

    Full Text Available Chromothripsis represents a novel phenomenon in the structural variation landscape of cancer genomes. Here, we analyze the genomes of ten patients with congenital disease who were preselected to carry complex chromosomal rearrangements with more than two breakpoints. The rearrangements displayed unanticipated complexity resembling chromothripsis. We find that eight of them contain hallmarks of multiple clustered double-stranded DNA breaks (DSBs on one or more chromosomes. In addition, nucleotide resolution analysis of 98 breakpoint junctions indicates that break repair involves nonhomologous or microhomology-mediated end joining. We observed that these eight rearrangements are balanced or contain sporadic deletions ranging in size between a few hundred base pairs and several megabases. The two remaining complex rearrangements did not display signs of DSBs and contain duplications, indicative of rearrangement processes involving template switching. Our work provides detailed insight into the characteristics of chromothripsis and supports a role for clustered DSBs driving some constitutional chromothripsis rearrangements.

  12. Composite materials. Volume 1: Properties, non-destructive testing, and repair

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, M.M. [United Technologies Corp., East Hartford, CT (United States)

    1997-12-31

    This book provides a practical overview of the different types, properties, applications and design implementations of the latest composite materials. It describes important composite families, including metals, ceramics, polymers and other engineered materials; shows how each type of composite may be designed, manufactured, strengthened, and repaired; introduces composite modeling techniques; and explains the major industrial applications for composites. Primary markets for this book include materials engineers and designers in aerospace, automotive and transportation industries; works managers, facilities engineers, test engineers, plant engineers, manufacturing and industrial engineers, and production managers; students in material science, mechanical engineering and metallurgy.

  13. Importance of Projects in Automotive Industry

    Science.gov (United States)

    Babeľová, Zdenka Gyurák; Lenhardtová, Zuzana; Cagáňová, Dagmar; Weidlichová-Luptáková, Stanislava

    2010-01-01

    For automotive companies, research and development is the key to success for new generation of products. The aim of this article is to accent the importance of innovations and innovations-focused projects in automotive industry. Relevance of co-operation between automotive industry and educational institutions is noticed in the article, too. Furthermore, history of automotive industry in Slovakia is outlined in the article. Main part of the article is focused on project AUTOCLUSTERS.

  14. Low-Density Steels: Complex Metallurgy for Automotive Applications

    Science.gov (United States)

    Zuazo, I.; Hallstedt, B.; Lindahl, B.; Selleby, M.; Soler, M.; Etienne, A.; Perlade, A.; Hasenpouth, D.; Massardier-Jourdan, V.; Cazottes, S.; Kleber, X.

    2014-09-01

    The current aim in the development of third-generation steels for lightweighting automotive applications is to increase strength keeping at least the same formability as current steel concepts. In this philosophy, an optimal concept would be one that brings, in addition, a lower density. For this purpose, low-density steels have been designed with important aluminum additions obtaining density reductions of 8-10% or higher in comparison with low-carbon steels. At the levels required for lightweighting, aluminum introduces complex phenomena in steels. Here, some of the effects of aluminum in phase stability, CALPHAD-type modeling, and microstructure development are described, the latter in relation with mechanical properties. Finally, the potential of two families of lightweight steels for automotive applications is assessed by comparison with a steel currently present in automotive structures.

  15. Comparative acoustic performance and mechanical properties of silk membranes for the repair of chronic tympanic membrane perforations.

    Science.gov (United States)

    Allardyce, Benjamin J; Rajkhowa, Rangam; Dilley, Rodney J; Xie, Zhigang; Campbell, Luke; Keating, Adrian; Atlas, Marcus D; von Unge, Magnus; Wang, Xungai

    2016-12-01

    The acoustic and mechanical properties of silk membranes of different thicknesses were tested to determine their suitability as a repair material for tympanic membrane perforations. Membranes of different thickness (10-100μm) were tested to determine their frequency response and their resistance to pressure loads in a simulated ear canal model. Their mechanical rigidity to pressure loads was confirmed by tensile testing. These membranes were tested alongside animal cartilage, currently the strongest available myringoplasty graft as well as paper, which is commonly used for simpler procedures. Silk membranes showed resonant frequencies within the human hearing range and a higher vibrational amplitude than cartilage, suggesting that silk may offer good acoustic energy transfer characteristics. Silk membranes were also highly resistant to simulated pressure changes in the middle ear, suggesting they can resist retraction, a common cause of graft failure resulting from chronic negative pressures in the middle ear. Part of this strength can be explained by the substantially higher modulus of silk films compared with cartilage. This allows for the production of films that are much thinner than cartilage, with superior acoustic properties, but that still provide the same level of mechanical support as thicker cartilage. Together, these in vitro results suggest that silk membranes may provide good hearing outcomes while offering similar levels of mechanical support to the reconstructed middle ear.

  16. Structure and stereochemistry of the base excision repair glycosylase MutY reveal a mechanism similar to retaining glycosidases.

    Science.gov (United States)

    Woods, Ryan D; O'Shea, Valerie L; Chu, Aurea; Cao, Sheng; Richards, Jody L; Horvath, Martin P; David, Sheila S

    2016-01-29

    MutY adenine glycosylases prevent DNA mutations by excising adenine from promutagenic 8-oxo-7,8-dihydroguanine (OG):A mismatches. Here, we describe structural features of the MutY active site bound to an azaribose transition state analog which indicate a catalytic role for Tyr126 and approach of the water nucleophile on the same side as the departing adenine base. The idea that Tyr126 participates in catalysis, recently predicted by modeling calculations, is strongly supported by mutagenesis and by seeing close contact between the hydroxyl group of this residue and the azaribose moiety of the transition state analog. NMR analysis of MutY methanolysis products corroborates a mechanism for adenine removal with retention of stereochemistry. Based on these results, we propose a revised mechanism for MutY that involves two nucleophilic displacement steps akin to the mechanisms accepted for 'retaining' O-glycosidases. This new-for-MutY yet familiar mechanism may also be operative in related base excision repair glycosylases and provides a critical framework for analysis of human MutY (MUTYH) variants associated with inherited colorectal cancer.

  17. Effects of suture position on left ventricular fluid mechanics under mitral valve edge-to-edge repair.

    Science.gov (United States)

    Du, Dongxing; Jiang, Song; Wang, Ze; Hu, Yingying; He, Zhaoming

    2014-01-01

    Mitral valve (MV) edge-to-edge repair (ETER) is a surgical procedure for the correction of mitral valve regurgitation by suturing the free edge of the leaflets. The leaflets are often sutured at three different positions: central, lateral and commissural portions. To study the effects of position of suture on left ventricular (LV) fluid mechanics under mitral valve ETER, a parametric model of MV-LV system during diastole was developed. The distribution and development of vortex and atrio-ventricular pressure under different suture position were investigated. Results show that the MV sutured at central and lateral in ETER creates two vortex rings around two jets, compared with single vortex ring around one jet of the MV sutured at commissure. Smaller total orifices lead to a higher pressure difference across the atrio-ventricular leaflets in diastole. The central suture generates smaller wall shear stresses than the lateral suture, while the commissural suture generated the minimum wall shear stresses in ETER.

  18. β1 integrin signaling in asymmetric migration of keratinocytes under mechanical stretch in a co-cultured wound repair model.

    Science.gov (United States)

    Lü, Dongyuan; Li, Zhan; Gao, Yuxin; Luo, Chunhua; Zhang, Fan; Zheng, Lu; Wang, Jiawen; Sun, Shujin; Long, Mian

    2016-12-28

    Keratinocyte (KC) migration in re-epithelization is crucial in repairing injured skin. But the mechanisms of how mechanical stimuli regulate the migration of keratinocytes have been poorly understood. Human immortalized keratinocyte HaCaT cells were co-cultured with skin fibroblasts on PDMS membranes and transferred to the static stretch device developed in-house for additional 6 day culture under mechanical stretch to mimic surface tension in skin. To detect the expression of proteins on different position at different time points and the effect of β1 integrin mechanotransduction on HaCaT migration, Immunofluorescence, Reverse transcription-polymerase chain reaction, Flow cytometry, Western blotting assays were applied. Mechanical receptor of β1 integrin that recognizes its ligand of collagen I was found to be strongly associated with migration of HaCaT cells since the knockdown of β1 integrin via RNA silence eliminated the key protein expression dynamically. Here the expression of vinculin was lower but that of Cdc42 was higher for the cells at outward edge than those at inward edge, respectively, supporting that the migration capability of keratinocytes is inversely correlated with the formation of focal adhesion complexes but positively related to the lamellipodia formation. This asymmetric expression feature was further confirmed by high or low expression of PI3K for outward- or inward-migrating cells. And ERK1/2 phosphorylation was up-regulated by mechanical stretch. We reported here, a novel mechanotransduction signaling pathways were β1 integrin-dependent pattern of keratinocytes migration under static stretch in an in vitro co-culture model. These results provided an insight into underlying molecular mechanisms of keratinocyte migration under mechanical stimuli.

  19. Intracellular Protein Shuttling: A Mechanism Relevant for Myelin Repair in Multiple Sclerosis?

    Directory of Open Access Journals (Sweden)

    Peter Göttle

    2015-07-01

    Full Text Available A prominent feature of demyelinating diseases such as multiple sclerosis (MS is the degeneration and loss of previously established functional myelin sheaths, which results in impaired signal propagation and axonal damage. However, at least in early disease stages, partial replacement of lost oligodendrocytes and thus remyelination occur as a result of resident oligodendroglial precursor cell (OPC activation. These cells represent a widespread cell population within the adult central nervous system (CNS that can differentiate into functional myelinating glial cells to restore axonal functions. Nevertheless, the spontaneous remyelination capacity in the adult CNS is inefficient because OPCs often fail to generate new oligodendrocytes due to the lack of stimulatory cues and the presence of inhibitory factors. Recent studies have provided evidence that regulated intracellular protein shuttling is functionally involved in oligodendroglial differentiation and remyelination activities. In this review we shed light on the role of the subcellular localization of differentiation-associated factors within oligodendroglial cells and show that regulation of intracellular localization of regulatory factors represents a crucial process to modulate oligodendroglial maturation and myelin repair in the CNS.

  20. Intracellular Protein Shuttling: A Mechanism Relevant for Myelin Repair in Multiple Sclerosis?

    Science.gov (United States)

    Göttle, Peter; Küry, Patrick

    2015-07-03

    A prominent feature of demyelinating diseases such as multiple sclerosis (MS) is the degeneration and loss of previously established functional myelin sheaths, which results in impaired signal propagation and axonal damage. However, at least in early disease stages, partial replacement of lost oligodendrocytes and thus remyelination occur as a result of resident oligodendroglial precursor cell (OPC) activation. These cells represent a widespread cell population within the adult central nervous system (CNS) that can differentiate into functional myelinating glial cells to restore axonal functions. Nevertheless, the spontaneous remyelination capacity in the adult CNS is inefficient because OPCs often fail to generate new oligodendrocytes due to the lack of stimulatory cues and the presence of inhibitory factors. Recent studies have provided evidence that regulated intracellular protein shuttling is functionally involved in oligodendroglial differentiation and remyelination activities. In this review we shed light on the role of the subcellular localization of differentiation-associated factors within oligodendroglial cells and show that regulation of intracellular localization of regulatory factors represents a crucial process to modulate oligodendroglial maturation and myelin repair in the CNS.

  1. CNS repair and axon regeneration: Using genetic variation to determine mechanisms.

    Science.gov (United States)

    Tedeschi, Andrea; Omura, Takao; Costigan, Michael

    2017-01-01

    The importance of genetic diversity in biological investigation has been recognized since the pioneering studies of Gregor Johann Mendel and Charles Darwin. Research in this area has been greatly informed recently by the publication of genomes from multiple species. Genes regulate and create every part and process in a living organism, react with the environment to create each living form and morph and mutate to determine the history and future of each species. The regenerative capacity of neurons differs profoundly between animal lineages and within the mammalian central and peripheral nervous systems. Here, we discuss research that suggests that genetic background contributes to the ability of injured axons to regenerate in the mammalian central nervous system (CNS), by controlling the regulation of specific signaling cascades. We detail the methods used to identify these pathways, which include among others Activin signaling and other TGF-β superfamily members. We discuss the potential of altering these pathways in patients with CNS damage and outline strategies to promote regeneration and repair by combinatorial manipulation of neuron-intrinsic and extrinsic determinants. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Structural basis for a novel mechanism of DNA bridging and alignment in eukaryotic DSB DNA repair.

    Science.gov (United States)

    Gouge, Jérôme; Rosario, Sandrine; Romain, Félix; Poitevin, Frédéric; Béguin, Pierre; Delarue, Marc

    2015-04-15

    Eukaryotic DNA polymerase mu of the PolX family can promote the association of the two 3'-protruding ends of a DNA double-strand break (DSB) being repaired (DNA synapsis) even in the absence of the core non-homologous end-joining (NHEJ) machinery. Here, we show that terminal deoxynucleotidyltransferase (TdT), a closely related PolX involved in V(D)J recombination, has the same property. We solved its crystal structure with an annealed DNA synapsis containing one micro-homology (MH) base pair and one nascent base pair. This structure reveals how the N-terminal domain and Loop 1 of Tdt cooperate for bridging the two DNA ends, providing a templating base in trans and limiting the MH search region to only two base pairs. A network of ordered water molecules is proposed to assist the incorporation of any nucleotide independently of the in trans templating base. These data are consistent with a recent model that explains the statistics of sequences synthesized in vivo by Tdt based solely on this dinucleotide step. Site-directed mutagenesis and functional tests suggest that this structural model is also valid for Pol mu during NHEJ.

  3. Mechanical Stress Changes the Complex Interplay Between HO-1, Inflammation and Fibrosis, During Excisional Wound Repair

    NARCIS (Netherlands)

    Cremers, N.A.J.; Suttorp, M.; Gerritsen, M.M.; Wong, R.J.; Run-van Breda, C. van; Dam, G.M. van; Brouwer, K.M.; Kuijpers-Jagtman, A.M.; Carels, C.E.L.; Lundvig, D.M.; Wagener, F.A.D.T.G.

    2015-01-01

    Mechanical stress following surgery or injury can promote pathological wound healing and fibrosis, and lead to functional loss and esthetic problems. Splinted excisional wounds can be used as a model for inducing mechanical stress. The cytoprotective enzyme heme oxygenase-1 (HO-1) is thought to orch

  4. Molecular pathology of mismatch repair deficient tumours with emphasis on immune escape mechanisms

    NARCIS (Netherlands)

    Dierssen, Jan Willem Frederik

    2010-01-01

    This thesis describes molecular methods to distinguish separate colon tumour entities. Furthermore, it shows that distinct immune escape mechanisms, in particular distinct mechanisms of corrupting the HLA system, are operational in subsets of colon tumours. The apparent necessity of some colon tumou

  5. Distinguishing between chemical and physical promotion mechanisms by CeO{sub 2} in Pt, Rh three-way automotive catalysts under practical industrial conditions

    Energy Technology Data Exchange (ETDEWEB)

    Robota, H.J.; Nunan, J.G. [Allied-Signal Research and Technology, Des Plains, IL (United States)

    1993-12-31

    Under practical industrial conditions, aged, rather than fresh, catalyst performances is required to meet various regulatory emissions levels. While CeO{sub 2} is recognized as critical in allowing practically aged Pt, Rh catalysts to meet these performance targets, debate continues concerning the physicochemical mechanisms responsible for the performance enhancement. Suppressed precious metal sintering and stabilization of support {gamma}-Al{sub 2}O{sub 3} against surface area loss and structural phase changes are the principle physical mechanisms suggested. Chemical promotion by CeO2 has been attributed to oxygen storage, enhanced water gas shift activity, and enhanced CO oxidation activity through a precious metal-CeO2 coupling mechanisms. The authors have attempted to distinguish the relative contributions of these physical and chemical mechanisms to the performance of practical Pt, Rh catalysts. Two catalysts were aged in tandem using standard dynamometer methods. One was a fully formulated reference catalyst and the other was a CeO{sub 2}-free catalyst. Several potential chemical promotional mechanisms of CO oxidation via a more facile reaction pathway involving coupling between the precious metals and CeO{sub 2}.

  6. DNA repair mechanism by photolyase: electron transfer path from the photolyase catalytic cofactor FADH(-) to DNA thymine dimer.

    Science.gov (United States)

    Medvedev, D; Stuchebrukhov, A A

    2001-05-21

    Photolyase is an enzyme that catalyses photorepair of thymine dimers in UV damaged DNA by electron transfer reaction. The structure of the photolyase/DNA complex is unknown at present. Using crystal structure coordinates of the substrate-free enzyme from E. coli, we have recently built a computer molecular model of a thymine dimer docked to photolyase catalytic site and studied molecular dynamics of the system. In this paper, we present analysis of the electronic coupling and electron transfer pathway between the catalytic cofactor FADH(-) and the pyrimidine dimer by the method of interatomic tunneling currents. Electronic structure is treated in the extended Hückel approximation. The root mean square transfer matrix element is about 6 cm(-1), which is consistent with the experimentally determined rate of transfer. We find that electron transfer mechanism responsible for the repair utilizes an unusual folded conformation of FADH(-) in photolyases, in which the isoalloxazine ring of the flavin and the adenine are in close proximity, and the peculiar features of the docked orientation of the dimer. The tunneling currents show explicitly that despite of the close proximity between the donor and acceptor complexes, the electron transfer mechanism between the flavin and the thymine bases is not direct, but indirect, with the adenine acting as an intermediate. These calculations confirm the previously made conclusion based on an indirect evidence for such mechanism.

  7. Cumulative asbestos exposure for US automobile mechanics involved in brake repair (circa 1950s-2000).

    Science.gov (United States)

    Finley, Brent L; Richter, Richard O; Mowat, Fionna S; Mlynarek, Steve; Paustenbach, Dennis J; Warmerdam, John M; Sheehan, Patrick J

    2007-11-01

    We analyzed cumulative lifetime exposure to chrysotile asbestos experienced by brake mechanics in the US during the period 1950-2000. Using Monte Carlo methods, cumulative exposures were calculated using the distribution of 8-h time-weighted average exposure concentrations for brake mechanics and the distribution of job tenure data for automobile mechanics. The median estimated cumulative exposures for these mechanics, as predicted by three probabilistic models, ranged from 0.16 to 0.41 fibers per cubic centimeter (f/cm(3)) year for facilities with no dust-control procedures (1970s), and from 0.010 to 0.012 f/cm(3) year for those employing engineering controls (1980s). Upper-bound (95%) estimates for the 1970s and 1980s were 1.96 to 2.79 and 0.07-0.10 f/cm(3) year, respectively. These estimates for US brake mechanics are consistent with, but generally slightly lower than, those reported for European mechanics. The values are all substantially lower than the cumulative exposure of 4.5 f/cm(3) year associated with occupational exposure to 0.1 f/cm(3) of asbestos for 45 years that is currently permitted under the current occupational exposure limits in the US. Cumulative exposures were usually about 100- to 1,000-fold less than those of other occupational groups with asbestos exposure for similar time periods. The cumulative lifetime exposure estimates presented here, combined with the negative epidemiology data for brake mechanics, could be used to refine the risk assessments for chrysotile-exposed populations.

  8. Asymmetric migration of human keratinocytes under mechanical stretch and cocultured fibroblasts in a wound repair model.

    Directory of Open Access Journals (Sweden)

    Dongyuan Lü

    Full Text Available Keratinocyte migration during re-epithelization is crucial in wound healing under biochemical and biomechanical microenvironment. However, little is known about the underlying mechanisms whereby mechanical tension and cocultured fibroblasts or keratinocytes modulate the migration of keratinocytes or fibroblasts. Here we applied a tensile device together with a modified transwell assay to determine the lateral and transmembrane migration dynamics of human HaCaT keratinocytes or HF fibroblasts. A novel pattern of asymmetric migration was observed for keratinocytes when they were cocultured with non-contact fibroblasts, i.e., the accumulative distance of HaCaT cells was significantly higher when moving away from HF cells or migrating from down to up cross the membrane than that when moving close to HF cells or when migrating from up to down, whereas HF migration was symmetric. This asymmetric migration was mainly regulated by EGF derived from fibroblasts, but not transforming growth factor α or β1 production. Mechanical stretch subjected to fibroblasts fostered keratinocyte asymmetric migration by increasing EGF secretion, while no role of mechanical stretch was found for EGF secretion by keratinocytes. These results provided a new insight into understanding the regulating mechanisms of two- or three-dimensional migration of keratinocytes or fibroblasts along or across dermis and epidermis under biomechanical microenvironment.

  9. NICKEL AS AN ALTERNATIVE AUTOMOTIVE BODY MATERIAL

    Directory of Open Access Journals (Sweden)

    T. Joseph Sahaya Anand

    2012-06-01

    Full Text Available The study of the thermal, chemical and mechanical properties of pure nickel as an alternative automotive body material is presented in this paper. Current automotive components mainly use steel as the body material. Due to the increasing demand for high performance and related issues, interest is moving towards alternative materials to steel. The hardness values of both heat-treated and non-heat treated pure nickel do not change after annealing; the hardness values are in the range of 118 to 123 HV. As the annealing temperature increases, the ultimate tensile strength, yield strength and Young’s modulus decrease, which indicates that the ductility increases. The highest ultimate tensile strength of pure nickel at 300 °C annealed temperature is 758.78 MPa. X-ray diffraction (XRD studies confirmed pure nickel as a face centred cubic (FCC structure with a lattice constant measured as 0.3492 nm for the unannealed sample, which increases to 0.3512 nm for the annealed samples. The corrosion rate of both annealed and non-heat treated pure nickel is in the range of 0.0266 to 0.048 mm/year.

  10. Farm and Ranch Mechanical Repair and VEH Farm and Ranch Maintenance. Curriculum Guide for Agribusiness 121. Agricultural Mechanics.

    Science.gov (United States)

    Texas A and M Univ., College Station. Dept. of Agricultural Education.

    This curriculum guide provides materials for teachers to use in developing a 1- or 2-year course in agricultural mechanics for at-risk and special education students. It is one of 28 semester courses in agricultural science and technology for Texas high schools. The program prepares low-achieving students with employability skills that are…

  11. A Protective Mechanism of Visible Red Light in Normal Human Dermal Fibroblasts: Enhancement of GADD45A-Mediated DNA Repair Activity.

    Science.gov (United States)

    Kim, Yeo Jin; Kim, Hyoung-June; Kim, Hye Lim; Kim, Hyo Jeong; Kim, Hyun Soo; Lee, Tae Ryong; Shin, Dong Wook; Seo, Young Rok

    2017-02-01

    The phototherapeutic effects of visible red light on skin have been extensively investigated, but the underlying biological mechanisms remain poorly understood. We aimed to elucidate the protective mechanism of visible red light in terms of DNA repair of UV-induced oxidative damage in normal human dermal fibroblasts. The protective effect of visible red light on UV-induced DNA damage was identified by several assays in both two-dimensional and three-dimensional cell culture systems. With regard to the protective mechanism of visible red light, our data showed alterations in base excision repair mediated by growth arrest and DNA damage inducible, alpha (GADD45A). We also observed an enhancement of the physical activity of GADD45A and apurinic/apyrimidinic endonuclease 1 (APE1) by visible red light. Moreover, UV-induced DNA damages were diminished by visible red light in an APE1-dependent manner. On the basis of the decrease in GADD45A-APE1 interaction in the activating transcription factor-2 (ATF2)-knockdown system, we suggest a role for ATF2 modulation in GADD45A-mediated DNA repair upon visible red light exposure. Thus, the enhancement of GADD45A-mediated base excision repair modulated by ATF2 might be a potential protective mechanism of visible red light. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Downsizing assessment of automotive Stirling engines

    Science.gov (United States)

    Knoll, R. H.; Tew, R. C., Jr.; Klann, J. L.

    1983-01-01

    A 67 kW (90 hp) Stirling engine design, sized for use in a 1984 1440 kg (3170 lb) automobile was the focal point for developing automotive Stirling engine technology. Since recent trends are towards lighter vehicles, an assessment was made of the applicability of the Stirling technology being developed for smaller, lower power engines. Using both the Philips scaling laws and a Lewis Research Center (Lewis) Stirling engine performance code, dimensional and performance characteristics were determined for a 26 kW (35 hp) and a 37 kW (50 hp) engine for use in a nominal 907 kg (2000 lb) vehicle. Key engine elements were sized and stressed and mechanical layouts were made to ensure mechanical fit and integrity of the engines. Fuel economy estimates indicated that the Stirling engine would maintain a 30 to 45 percent fuel economy advantage comparable spark ignition and diesel powered vehicles in the 1984 period.

  13. Mechanism of repair of acrolein- and malondialdehyde-derived exocyclic guanine adducts by the α-ketoglutarate/Fe(II) dioxygenase AlkB.

    Science.gov (United States)

    Singh, Vipender; Fedeles, Bogdan I; Li, Deyu; Delaney, James C; Kozekov, Ivan D; Kozekova, Albena; Marnett, Lawrence J; Rizzo, Carmelo J; Essigmann, John M

    2014-09-15

    The structurally related exocyclic guanine adducts α-hydroxypropano-dG (α-OH-PdG), γ-hydroxypropano-dG (γ-OH-PdG), and M1dG are formed when DNA is exposed to the reactive aldehydes acrolein and malondialdehyde (MDA). These lesions are believed to form the basis for the observed cytotoxicity and mutagenicity of acrolein and MDA. In an effort to understand the enzymatic pathways and chemical mechanisms that are involved in the repair of acrolein- and MDA-induced DNA damage, we investigated the ability of the DNA repair enzyme AlkB, an α-ketoglutarate/Fe(II) dependent dioxygenase, to process α-OH-PdG, γ-OH-PdG, and M1dG in both single- and double-stranded DNA contexts. By monitoring the repair reactions using quadrupole time-of-flight (Q-TOF) mass spectrometry, it was established that AlkB can oxidatively dealkylate γ-OH-PdG most efficiently, followed by M1dG and α-OH-PdG. The AlkB repair mechanism involved multiple intermediates and complex, overlapping repair pathways. For example, the three exocyclic guanine adducts were shown to be in equilibrium with open-ring aldehydic forms, which were trapped using (pentafluorobenzyl)hydroxylamine (PFBHA) or NaBH4. AlkB repaired the trapped open-ring form of γ-OH-PdG but not the trapped open-ring of α-OH-PdG. Taken together, this study provides a detailed mechanism by which three-carbon bridge exocyclic guanine adducts can be processed by AlkB and suggests an important role for the AlkB family of dioxygenases in protecting against the deleterious biological consequences of acrolein and MDA.

  14. Transcriptomic analysis of tail regeneration in the lizard Anolis carolinensis reveals activation of conserved vertebrate developmental and repair mechanisms.

    Directory of Open Access Journals (Sweden)

    Elizabeth D Hutchins

    Full Text Available Lizards, which are amniote vertebrates like humans, are able to lose and regenerate a functional tail. Understanding the molecular basis of this process would advance regenerative approaches in amniotes, including humans. We have carried out the first transcriptomic analysis of tail regeneration in a lizard, the green anole Anolis carolinensis, which revealed 326 differentially expressed genes activating multiple developmental and repair mechanisms. Specifically, genes involved in wound response, hormonal regulation, musculoskeletal development, and the Wnt and MAPK/FGF pathways were differentially expressed along the regenerating tail axis. Furthermore, we identified 2 microRNA precursor families, 22 unclassified non-coding RNAs, and 3 novel protein-coding genes significantly enriched in the regenerating tail. However, high levels of progenitor/stem cell markers were not observed in any region of the regenerating tail. Furthermore, we observed multiple tissue-type specific clusters of proliferating cells along the regenerating tail, not localized to the tail tip. These findings predict a different mechanism of regeneration in the lizard than the blastema model described in the salamander and the zebrafish, which are anamniote vertebrates. Thus, lizard tail regrowth involves the activation of conserved developmental and wound response pathways, which are potential targets for regenerative medical therapies.

  15. Advanced self-healing asphalt composites in the pavement performance field: mechanisms at the nano level and new repairing methodologies.

    Science.gov (United States)

    Agzenai, Yahya; Pozuelo, Javier; Sanz, Javier; Perez, Ignacio; Baselga, Juan

    2015-01-01

    In an effort to give a global view of this field of research, in this mini-review we highlight the most recent publications and patents focusing on modified asphalt pavements that contain certain reinforcing nanoparticles which impart desirable thermal, electrical and mechanical properties. In response to the increasing cost of asphalt binder and road maintenance, there is a need to look for alternative technologies and new asphalt composites, able to self-repair, for preserving and renewing the existing pavements. First, we will focus on the self-healing property of asphalt, the evidences that support that healing takes place immediately after the contact between the faces of a crack, and how the amount of healing can be measured in both the laboratory and the field. Next we review the hypothetical mechanisms of healing to understand the material behaviour and establish models to quantify the damage-healing process. Thereafter, we outline different technologies, nanotechnologies and methodologies used for self-healing paying particular attention to embedded micro-capsules, new nano-materials like carbon nanotubes and nano-fibres, ionomers, and microwave and induction heating processes.

  16. Transcriptomic analysis of tail regeneration in the lizard Anolis carolinensis reveals activation of conserved vertebrate developmental and repair mechanisms.

    Science.gov (United States)

    Hutchins, Elizabeth D; Markov, Glenn J; Eckalbar, Walter L; George, Rajani M; King, Jesse M; Tokuyama, Minami A; Geiger, Lauren A; Emmert, Nataliya; Ammar, Michael J; Allen, April N; Siniard, Ashley L; Corneveaux, Jason J; Fisher, Rebecca E; Wade, Juli; DeNardo, Dale F; Rawls, J Alan; Huentelman, Matthew J; Wilson-Rawls, Jeanne; Kusumi, Kenro

    2014-01-01

    Lizards, which are amniote vertebrates like humans, are able to lose and regenerate a functional tail. Understanding the molecular basis of this process would advance regenerative approaches in amniotes, including humans. We have carried out the first transcriptomic analysis of tail regeneration in a lizard, the green anole Anolis carolinensis, which revealed 326 differentially expressed genes activating multiple developmental and repair mechanisms. Specifically, genes involved in wound response, hormonal regulation, musculoskeletal development, and the Wnt and MAPK/FGF pathways were differentially expressed along the regenerating tail axis. Furthermore, we identified 2 microRNA precursor families, 22 unclassified non-coding RNAs, and 3 novel protein-coding genes significantly enriched in the regenerating tail. However, high levels of progenitor/stem cell markers were not observed in any region of the regenerating tail. Furthermore, we observed multiple tissue-type specific clusters of proliferating cells along the regenerating tail, not localized to the tail tip. These findings predict a different mechanism of regeneration in the lizard than the blastema model described in the salamander and the zebrafish, which are anamniote vertebrates. Thus, lizard tail regrowth involves the activation of conserved developmental and wound response pathways, which are potential targets for regenerative medical therapies.

  17. Insights into the epigenetic mechanisms involving histone lysine methylation and demethylation in ischemia induced damage and repair has therapeutic implication.

    Science.gov (United States)

    Chakravarty, Sumana; Jhelum, Priya; Bhat, Unis Ahmad; Rajan, Wenson D; Maitra, Swati; Pathak, Salil S; Patel, Anant B; Kumar, Arvind

    2017-01-01

    Cerebral ischemic stroke is one of the leading causes of death and disability worldwide. Therapeutic interventions to minimize ischemia-induced neural damage are limited due to poor understanding of molecular mechanisms mediating complex pathophysiology in stroke. Recently, epigenetic mechanisms mostly histone lysine (K) acetylation and deacetylation have been implicated in ischemic brain damage and have expanded the dimensions of potential therapeutic intervention to the systemic/local administration of histone deacetylase inhibitors. However, the role of other epigenetic mechanisms such as histone lysine methylation and demethylation in stroke-induced damage and subsequent recovery process is elusive. Here, we established an Internal Carotid Artery Occlusion (ICAO) model in CD1 mouse that resulted in mild to moderate level of ischemic damage to the striatum, as suggested by magnetic resonance imaging (MRI), TUNEL and histopathological staining along with an evaluation of neurological deficit score (NDS), grip strength and rotarod performance. The molecular investigations show dysregulation of a number of histone lysine methylases (KMTs) and few of histone lysine demethylases (KDMs) post-ICAO with significant global attenuation in the transcriptionally repressive epigenetic mark H3K9me2 in the striatum. Administration of Dimethyloxalylglycine (DMOG), an inhibitor of KDM4 or JMJD2 class of histone lysine demethylases, significantly ameliorated stroke-induced NDS by restoring perturbed H3K9me2 levels in the ischemia-affected striatum. Overall, these results highlight the novel role of epigenetic regulatory mechanisms controlling the epigenetic mark H3K9me2 in mediating the stroke-induced striatal damage and subsequent repair following mild to moderate cerebral ischemia.

  18. Cellular and molecular mechanisms of repair in acute and chronic wound healing.

    Science.gov (United States)

    Martin, P; Nunan, R

    2015-08-01

    A considerable understanding of the fundamental cellular and molecular mechanisms underpinning healthy acute wound healing has been gleaned from studying various animal models, and we are now unravelling the mechanisms that lead to chronic wounds and pathological healing including fibrosis. A small cut will normally heal in days through tight orchestration of cell migration and appropriate levels of inflammation, innervation and angiogenesis. Major surgeries may take several weeks to heal and leave behind a noticeable scar. At the extreme end, chronic wounds - defined as a barrier defect that has not healed in 3 months - have become a major therapeutic challenge throughout the Western world and will only increase as our populations advance in age, and with the increasing incidence of diabetes, obesity and vascular disorders. Here we describe the clinical problems and how, through better dialogue between basic researchers and clinicians, we may extend our current knowledge to enable the development of novel potential therapeutic treatments.

  19. Antenna Arrays and Automotive Applications

    CERN Document Server

    Rabinovich, Victor

    2013-01-01

    This book throws a lifeline to designers wading through mounds of antenna array patents looking for the most suitable systems for their projects. Drastically reducing the research time required to locate solutions to the latest challenges in automotive communications, it sorts and systematizes material on cutting-edge antenna arrays that feature multi-element communication systems with enormous potential for the automotive industry. These new systems promise to make driving safer and more efficient, opening up myriad applications, including vehicle-to-vehicle traffic that prevents collisions, automatic toll collection, vehicle location and fine-tuning for cruise control systems. This book’s exhaustive coverage begins with currently deployed systems, frequency ranges and key parameters. It proceeds to examine system geometry, analog and digital beam steering technology (including "smart" beams formed in noisy environments), maximizing signal-to-noise ratios, miniaturization, and base station technology that ...

  20. Recycling used automotive oil filters

    Science.gov (United States)

    Peaslee, Kent D.

    1994-02-01

    Over 400 million used automotive oil filters are discarded in the United States each year, most of which are disposed of in landfills wasting valuable resources and risking contamination of ground- and surface-water supplies. This article summarizes U.S. bureau of Mines research evaluating scrap prepared from used automotive oil filters. Experimental results show that crushed and drained oil filters have a bulk density that is higher than many typical scrap grades, a chemical analysis low in residual elements (except tin due to use of tin plate in filters), and an overall yield, oil-filter scrap to cast steel, of 76% to 85%, depending on the method used to prepare the scrap.

  1. GLOBAL PERSPECTIVES IN AUTOMOTIVE INDUSTRY

    Directory of Open Access Journals (Sweden)

    NICOLETA ISAC

    2010-01-01

    Full Text Available The automotive sector is characterised by a relatively low trade/salesratio. While the production of most automotive producers in the world is spread over variouscountries in the value chain, the brands are still considered to reflect some national identity.Internationalisation strategies may change over the lifecycle of the product and automakerstend to pursue diametrically opposed strategies. In mature markets, it is about managing whatgoes on beneath a static surface; in emerging markets’ dynamic environments, companies muststrategically position themselves to benefit from growth opportunities. However, without theright strategy and execution in mature markets, it is clear that traditional OEMs cannot profitfrom emerging markets-the persistence of structural issues in mature market operationseventually will rob all but the most resilient competitors of the opportunity to compete inemerging markets.

  2. A mathematical model of the process of ligament repair: effect of cold therapy and mechanical stress.

    Science.gov (United States)

    Cárdenas Sandoval, Rosy Paola; Garzón-Alvarado, Diego Alexander; Ramírez Martínez, Angélica Maria

    2012-06-07

    This article proposes a mathematical model that predicts the wound healing process of the ligament after a sprain, grade II. The model describes the swelling, expression of the platelet-derived growth factor (PDGF), formation and migration of fibroblasts into the injury area and the expression of collagen fibers. Additionally, the model can predict the effect of ice treatment in reducing inflammation and the action of mechanical stress in the process of remodeling of collagen fibers. The results obtained from computer simulation show a high concordance with the clinical data previously reported by other authors.

  3. Rejuvenation of automotive fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Seung; Langlois, David A.

    2016-08-23

    A process for rejuvenating fuel cells has been demonstrated to improve the performance of polymer exchange membrane fuel cells with platinum/ionomer electrodes. The process involves dehydrating a fuel cell and exposing at least the cathode of the fuel cell to dry gas (nitrogen, for example) at a temperature higher than the operating temperature of the fuel cell. The process may be used to prolong the operating lifetime of an automotive fuel cell.

  4. On Ugliness and the Automotive

    DEFF Research Database (Denmark)

    Herriott, Richard

    2016-01-01

    The function of this essay is to to see what consequences a consideration of ugliness in automotive styling has for the theories of three writers on aesthetics in design: David Pye, Roger Scruton and Ralf Weber. As such, the concepts of beauty and ugliness will be treated in brief before moving...... on to look at an outline of the three aesthetic theories in relation to car design....

  5. Distinct mechanisms for opposite functions of homeoproteins Cdx2 and HoxB7 in double-strand break DNA repair in colon cancer cells.

    Science.gov (United States)

    Soret, Christine; Martin, Elisabeth; Duluc, Isabelle; Dantzer, Françoise; Vanier, Marie; Gross, Isabelle; Freund, Jean-Noël; Domon-Dell, Claire

    2016-05-01

    Homeobox genes, involved in embryonic development and tissues homeostasis in adults, are often deregulated in cancer, but their relevance in pathology is far from being fully elucidated. In colon cancers, we report that the homeoproteins HoxB7 and Cdx2 exhibit different heterogeneous patterns, Cdx2 being localized in moderately altered neoplasic glands in contrast to HoxB7 which predominates in poorly-differentiated areas; they are coexpressed in few cancer cells. In human colon cancer cells, both homeoproteins interact with the DNA repair factor KU70/80, but functional studies reveal opposite effects: HoxB7 stimulates DNA repair and cell survival upon etoposide treatment, whereas Cdx2 inhibits both processes. The stimulatory effect of HoxB7 on DNA repair requires the transactivation domain linked to the homeodomain involved in the interaction with KU70/80, whereas the transactivation domain of Cdx2 is dispensable for its inhibitory function, which instead needs the homeodomain to interact with KU70/80 and the C-terminal domain. Thus, HoxB7 and Cdx2 respectively use transcription-dependent and -independent mechanisms to stimulate and inhibit DNA repair. In addition, in cells co-expressing both homeoproteins, Cdx2 lessens DNA repair activity through a novel mechanism of inhibition of the transcriptional function of HoxB7, whereby Cdx2 forms a molecular complex with HoxB7 and prevents it to recognize its target in the chromatin. These results point out the complex interplay between the DSB DNA repair activity and the homeoproteins HoxB7 and Cdx2 in colon cancer cells, making the balance between these factors a determinant and a potential indicator of the efficacy of genotoxic drugs.

  6. The fluid mechanics of scleral buckling surgery for the repair of retinal detachment.

    Science.gov (United States)

    Foster, William Joseph; Dowla, Nadia; Joshi, Saurabh Y; Nikolaou, Michael

    2010-01-01

    Scleral buckling is a common surgical technique used to treat retinal detachments that involves suturing a radial or circumferential silicone element on the sclera. Although this procedure has been performed since the 1960s, and there is a reasonable experimental model of retinal detachment, there is still debate as to how this surgery facilitates the re-attachment of the retina. Finite element calculations using the COMSOL Multiphysics system are utilized to explain the influence of the scleral buckle on the flow of sub-retinal fluid in a physical model of retinal detachment. We found that, by coupling fluid mechanics with structural mechanics, laminar fluid flow and the Bernoulli effect are necessary for a physically consistent explanation of retinal reattachment. Improved fluid outflow and retinal reattachment are found with low fluid viscosity and rapid eye movements. A simulation of saccadic eye movements was more effective in removing sub-retinal fluid than slower, reading speed, eye movements in removing subretinal fluid. The results of our simulations allow us to explain the physical principles behind scleral buckling surgery and provide insight that can be utilized clinically. In particular, we find that rapid eye movements facilitate more rapid retinal reattachment. This is contradictory to the conventional wisdom of attempting to minimize eye movements.

  7. Mechanical evaluation of gradient electrospun scaffolds with 3D printed ring reinforcements for tracheal defect repair.

    Science.gov (United States)

    Ott, Lindsey M; Zabel, Taylor A; Walker, Natalie K; Farris, Ashley L; Chakroff, Jason T; Ohst, Devan G; Johnson, Jed K; Gehrke, Steven H; Weatherly, Robert A; Detamore, Michael S

    2016-04-21

    Tracheal stenosis can become a fatal condition, and current treatments include augmentation of the airway with autologous tissue. A tissue-engineered approach would not require a donor source, while providing an implant that meets both surgeons' and patients' needs. A fibrous, polymeric scaffold organized in gradient bilayers of polycaprolactone (PCL) and poly-lactic-co-glycolic acid (PLGA) with 3D printed structural ring supports, inspired by the native trachea rings, could meet this need. The purpose of the current study was to characterize the tracheal scaffolds with mechanical testing models to determine the design most suitable for maintaining a patent airway. Degradation over 12 weeks revealed that scaffolds with the 3D printed rings had superior properties in tensile and radial compression, with at least a three fold improvement and 8.5-fold improvement, respectively, relative to the other scaffold groups. The ringed scaffolds produced tensile moduli, radial compressive forces, and burst pressures similar to or exceeding physiological forces and native tissue data. Scaffolds with a thicker PCL component had better suture retention and tube flattening recovery properties, with the monolayer of PCL (PCL-only group) exhibiting a 2.3-fold increase in suture retention strength (SRS). Tracheal scaffolds with ring reinforcements have improved mechanical properties, while the fibrous component increased porosity and cell infiltration potential. These scaffolds may be used to treat various trachea defects (patch or circumferential) and have the potential to be employed in other tissue engineering applications.

  8. [Molecular repair mechanisms using the Intratissue Percutaneous Electrolysis technique in patellar tendonitis].

    Science.gov (United States)

    Abat, F; Valles, S L; Gelber, P E; Polidori, F; Stitik, T P; García-Herreros, S; Monllau, J C; Sanchez-Ibánez, J M

    2014-01-01

    To investigate the molecular mechanisms of tissue response after treatment with the Intratissue Percutaneous Electrolysis (EPI(®)) technique in collagenase-induced tendinopathy in Sprague-Dawley rats. Tendinopathy was induced by injecting 50 μg of type i collagenase into the patellar tendon of 24 Sprague Dawley rats of 7 months of age and weighting 300 g. The sample was divided into 4 groups: the control group, collagenase group, and two EPI(®) technique treatment groups of 3 and 6 mA, respectively. An EPI(®) treatment session was applied, and after 3 days, the tendons were analysed using immunoblotting and electrophoresis techniques. An analysis was also made of cytochrome C protein, Smac/Diablo, vascular endothelial growth factor and its receptor 2, as well as the nuclear transcription factor peroxisome proliferator-activated receptor gamma. A statistically significant increase, compared to the control group, was observed in the expression of cytochrome C, Smac/Diablo, vascular endothelial growth factor, its receptor 2 and peroxisome proliferator-activated receptor gamma in the groups in which the EPI(®) technique was applied. EPI(®) technique produces an increase in anti-inflammatory and angiogenic molecular mechanisms in collagenase-induced tendon injury in rats. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  9. Stimulation of bone repair with ultrasound: a review of the possible mechanic effects.

    Science.gov (United States)

    Padilla, Frédéric; Puts, Regina; Vico, Laurence; Raum, Kay

    2014-07-01

    In vivo and in vitro studies have demonstrated the positive role that ultrasound can play in the enhancement of fracture healing or in the reactivation of a failed healing process. We review the several options available for the use of ultrasound in this context, either to induce a direct physical effect (LIPUS, shock waves), to deliver bioactive molecules such as growth factors, or to transfect cells with osteogenic plasmids; with a main focus on LIPUS (or Low Intensity Pulsed Ultrasound) as it is the most widespread and studied technique. The biological response to LIPUS is complex as numerous cell types respond to this stimulus involving several pathways. Known to-date mechanotransduction pathways involved in cell responses include MAPK and other kinases signaling pathways, gap-junctional intercellular communication, up-regulation and clustering of integrins, involvement of the COX-2/PGE2, iNOS/NO pathways and activation of ATI mechanoreceptor. The mechanisms by which ultrasound can trigger these effects remain intriguing. Possible mechanisms include direct and indirect mechanical effects like acoustic radiation force, acoustic streaming, and propagation of surface waves, fluid-flow induced circulation and redistribution of nutrients, oxygen and signaling molecules. Effects caused by the transformation of acoustic wave energy into heat can usually be neglected, but heating of the transducer may have a potential impact on the stimulation in some in-vitro systems, depending on the coupling conditions. Cavitation cannot occur at the pressure levels delivered by LIPUS. In-vitro studies, although not appropriate to identify the overall biological effects, are of great interest to study specific mechanisms of action. The diversity of current experimental set-ups however renders this analysis very complex, as phenomena such as transducer heating, inhomogeneities of the sound intensity in the near field, resonances in the transmission and reflection through the culture

  10. Development of a novel sodium fusidate-loaded triple polymer hydrogel wound dressing: Mechanical properties and effects on wound repair.

    Science.gov (United States)

    Jin, Sung Giu; Kim, Kyeong Soo; Kim, Dong Wuk; Kim, Dong Shik; Seo, Youn Gee; Go, Toe Gyung; Youn, Yu Seok; Kim, Jong Oh; Yong, Chul Soon; Choi, Han-Gon

    2016-01-30

    To develop a novel sodium fusidate-loaded triple polymer hydrogel dressing (TPHD), numerious polyvinyl alcohol-based (PVA) hydrogel dressings were prepared with various hydrophilic polymers using the freeze-thaw method, and their hydrogel dressing properties were assessed. Among the hydrophilic polymers tested, sodium alginate (SA) improved the swelling capacity the most, and polyvinyl pyrrolidone (PVP) provided the greatest improvement in bioadhesive stength and mechanical properties. Thus, PVA based-TPHDs were prepared using different ratios of PVP:SA. The effect of selected PVP:SA ratios on the swelling capacity, bioadhesive strength, mechanical properties, and drug release, permeation and deposition characteristics of sodium fusidate-loaded PVA-based TPHDs were assessed. As the ratio of PVP:SA increased in PVA-loaded TPHD, the swelling capacity, mechanical properties, drug release, permeation and deposition were improved. The TPHD containing PVA, PVP, SA and sodium fusidate at the weight ratio of 10/6/1/1 showed excellent hydrogel dressing properties, release, permeation and deposition of drug. Within 24h, 71.8 ± 1.3% of drug was released. It permeated 625.1 ± 81.2 μg/cm(2) through the skin and deposited of 313.8 ± 24.1 μg/cm(2) within 24h. The results of in vivo pharmacodynamic studies showed that sodium fusidate-loaded TPHD was more effective in improving the repair process than was a commercial product. Thus, this sodium fusidate-loaded TPHD could be a novel tool in wound care.

  11. Electrospun Matrices for Pelvic Floor Repair: Effect of Fiber Diameter on Mechanical Properties and Cell Behavior.

    Science.gov (United States)

    Vashaghian, Mahshid; Zandieh-Doulabi, Behrouz; Roovers, Jan-Paul; Smit, Theodoor Henri

    2016-12-01

    Electrospun matrices are proposed as an alternative for polypropylene meshes in reconstructive pelvic surgery. Here, we investigated the effect of fiber diameter on (1) the mechanical properties of electrospun poly (lactic-co-glycolic acid)-blended-poly(caprolactone) (PLGA/PCL) matrices; (2) cellular infiltration; and (3) the newly formed extracellular matrix (ECM) in vitro. We compared electrospun matrices with 1- and 8 μm fiber diameter and used nonporous PLGA/PCL films as controls. The 8-μm matrices were almost twice as stiff as the 1-μm matrices with 1.38 and 0.66 MPa, respectively. Matrices had the same ultimate tensile strength, but with 80% the 1-μm matrices were much more ductile than the 8-μm ones (18%). Cells infiltrated deeper into the matrices with larger pores, but cellular activity was comparable on both substrates. New ECM was deposited faster on the electrospun samples, but after 2 and 4 weeks the amount of collagen was comparable with that on nonporous films. The ECM deposited on the 1-μm matrices, and the nonporous film was about three times stiffer than the ECM found on the 8-μm matrices. Cell behavior in terms of myofibroblastic differentiation and remodeling was similar on the 1-μm matrices and nonporous films, in comparison to that on the 8-μm matrices. We conclude that electrospinning enhances the integration of host cells as compared with a nonporous film of the same material. The 1-μm matrices result in better mechanical behavior and qualitatively better matrix production than the 8-μm matrices, but with limited cellular infiltration. These data are useful for designing electrospun matrices for the pelvic floor.

  12. Optimality in DNA repair.

    Science.gov (United States)

    Richard, Morgiane; Fryett, Matthew; Miller, Samantha; Booth, Ian; Grebogi, Celso; Moura, Alessandro

    2012-01-07

    DNA within cells is subject to damage from various sources. Organisms have evolved a number of mechanisms to repair DNA damage. The activity of repair enzymes carries its own risk, however, because the repair of two nearby lesions may lead to the breakup of DNA and result in cell death. We propose a mathematical theory of the damage and repair process in the important scenario where lesions are caused in bursts. We use this model to show that there is an optimum level of repair enzymes within cells which optimises the cell's response to damage. This optimal level is explained as the best trade-off between fast repair and a low probability of causing double-stranded breaks. We derive our results analytically and test them using stochastic simulations, and compare our predictions with current biological knowledge.

  13. International Congress of Automotive and Transport Engineering

    CERN Document Server

    Ispas, Nicolae

    2017-01-01

    The volume will include selected and reviewed papers from CONAT - International Congress of Automotive and Transport Engineering to be held in Brasov, Romania, in October 2016. Authors are experts from research, industry and universities coming from 14 countries worldwide. The papers are covering the latest developments in automotive vehicles and environment, advanced transport systems and road traffic, heavy and special vehicles, new materials, manufacturing technologies and logistics, accident research and analysis and innovative solutions for automotive vehicles. The conference will be organized by SIAR (Society of Automotive Engineers from Romania) in cooperation with FISITA. .

  14. Skeletal myoblasts for heart regeneration and repair: state of the art and perspectives on the mechanisms for functional cardiac benefits.

    Science.gov (United States)

    Formigli, L; Zecchi-Orlandini, S; Meacci, E; Bani, D

    2010-01-01

    Until recently, skeletal myoblasts (SkMBs) have been the most widely used cells in basic research and clinical trials of cell based therapy for cardiac repair and regeneration. Although SkMB engraftment into the post-infarcted heart has been consistently found to improve cardiac contractile function, the underlying therapeutic mechanisms remain still a matter of controversy and debate. This is basically because SkMBs do not attain a cardiac-like phenotype once homed into the diseased heart nor they form a contractile tissue functionally coupled with the surrounding viable myocardium. This issue of concern has generated the idea that the cardiotropic action of SkMBs may depend on the release of paracrine factors. However, the paracrine hypothesis still remains ill-defined, particularly concerning the identification of the whole spectrum of cell-derived soluble factors and details on their cardiac effects. In this context, the possibility to genetically engineering SkMBs to potentate their paracrine attitudes appears particularly attractive and is actually raising great expectation. Aim of the present review is not to cover all the aspects of cell-based therapy with SkMBs, as this has been the object of previous exhaustive reviews in this field. Rather, we focused on novel aspects underlying the interactions between SkMBs and the host cardiac tissues which may be relevant for directing the future basic and applied research on SkMB transplantation for post ischemic cardiac dysfunction.

  15. Mechanical behavior of colonic anastomosis in experimental settings as a measure of wound repair and tissue integrity

    Institute of Scientific and Technical Information of China (English)

    Konstantinos A Ekmektzoglou; Georgios C Zografos; Stavros K Kourkoulis; Ismene A Dontas; Panagiotis K Giannopoulos; Katerina A Marinou; Maria V Poulakou; Despina N Perrea

    2006-01-01

    AIM: To determine the mechanical properties of anastomotic colonic tissue in experimental settings and therefore give a measure of wound healing.METHODS: Thirty-six male Wistar rats were used as experimental models of anastomotic tissue integrity. On the 5th post-operative day, the tensile strength was measured by application of an axial force, providing a quantitative measure of anastomotic dehiscence and leakage.RESULTS: Diagrams of the load as a function of the time [P = P (t)] and of the displacement also as a function of time [△s = △s (t)] were recorded for each test,permitting the design of the load versus the displacement diagram and thus providing significant data about the critical values of anastomotic failure. Quantitative data were obtained concerning the anastomotic strength of both control specimens (healthy rats), as well as specimens from non-healthy rats for comparison.CONCLUSION: This experimental model provides an excellent method of measuring anastomotic strength.Despite the relative small number of specimens used,this method provides an accurate way of measuring wound repair. More experimental measurements need to be performed to correlate emerging tensile strength values to anastomotic failure.

  16. Porous alumina, zirconia and alumina/zirconia for bone repair: fabrication, mechanical and in vitro biological response.

    Science.gov (United States)

    Hadjicharalambous, Chrystalleni; Buyakov, Ales; Buyakova, Svetlana; Kulkov, Sergey; Chatzinikolaidou, Maria

    2015-04-23

    Zirconia (ZrO2) and alumina (Al2O3) based ceramics are widely used for load-bearing applications in bone repair due to their excellent mechanical properties and biocompatibility. They are often regarded as bioinert since no direct bone-material interface is created unless a porous structure intercedes, leading to better bone bonding. In this regard, investigating interactions between cells and porous ceramics is of great interest. In the present study, we report on the successful fabrication of sintered alumina A-61, zirconia Z-50 and zirconia/alumina composite ZA-60 ceramics with medium porosities of 61, 50 and 60%, respectively, indicating a bimodal pore size distribution and good interconnectivity. They exhibit elastic moduli of 3-10 GPa and compressive strength values of 60-240 MPa, similar to those of human cortical bone.We performed in vitro cell-material investigations comparing the adhesion, proliferation and differentiation of mouse pre-osteoblasts MC3T3-E1 on the three porous materials. While all three ceramics demonstrate a strong cell attachment, better cell spreading is observed on zirconia-containing substrates. Significantly higher cell growth was quantified on the latter ceramics, revealing an increased alkaline phosphatase activity, higher collagen production and increased calcium biomineralization compared to A-61. Hence, these porous zirconia-containing ceramics elicit superior biological responses over porous alumina of similar porosity, promoting enhanced biological interaction, with potential use as non-degradable bone grafts or as implant coatings.

  17. Analysis of Workplace Accidents in Automotive Repair Workshops in Spain

    Directory of Open Access Journals (Sweden)

    Antonio López-Arquillos

    2016-09-01

    Conclusion: Health and safety strategies and accident prevention measures should be individualized and adapted to the type of worker most likely to be injured in each type of accident. Occupational health and safety training courses designed according to worker profile, and improving the participation of the workers in small firms creating regional or roving safety representatives would improve working conditions.

  18. Experimental Research of Automotive Needlepunched Carpets at Thermoforming Temperatures

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yun-qing; GUO Zhi-ying; DONG xiang-huai; LI De-qun

    2007-01-01

    Tensile prerties with different thermoformingconditions and deformation mechanism at thermoformingtemperatures of automotive needlepunched carpets made up ofthree layers of different materials were reported.Investigations on the tensile properties were performed as afunction of thermoforming temperature, extensile speed andfiber orientation based on an orthogonal experiment design.The experimental results show that the automotive carpets arerate-dependent anisotropic one and very sensitive to theforming temperature. The tensile properties are stronglydepended an the forming temperature when compared with theextensile speed and the fiber orientation. Experiments onlyvarying with the temperature were performed because of thedominative effect of the temperature. Different defotmationperformances were observed with different temperatures.Deformation mechanisms at the thermoforming temperatureswere presented to explain the nonlinear trend of the ultimateelongation with the temperatures based on the combination ofthe experimental observations and the corresponding polymertheories.

  19. Base excision repair efficiency and mechanism in nuclear extracts are influenced by the ratio between volume of nuclear extraction buffer and nuclei-Implications for comparative studies

    DEFF Research Database (Denmark)

    Akbari, Mansour; Krokan, Hans E

    2012-01-01

    The base excision repair (BER) pathway corrects many different DNA base lesions and is important for genomic stability. The mechanism of BER cannot easily be investigated in intact cells and therefore in vitro methods that reflect the in vivo processes are in high demand. Reconstitution of BER...... using purified proteins essentially mirror properties of the proteins used, and does not necessarily reflect the mechanism as it occurs in the cell. Nuclear extracts from cultured cells have the capacity to carry out complete BER and can give important information on the mechanism. Furthermore...

  20. Automotive Control Systems: For Engine, Driveline, and Vehicle

    Science.gov (United States)

    Kiencke, Uwe; Nielsen, Lars

    Advances in automotive control systems continue to enhance safety and comfort and to reduce fuel consumption and emissions. Reflecting the trend to optimization through integrative approaches for engine, driveline, and vehicle control, this valuable book enables control engineers to understand engine and vehicle models necessary for controller design, and also introduces mechanical engineers to vehicle-specific signal processing and automatic control. The emphasis on measurement, comparisons between performance and modeling, and realistic examples derive from the authors' unique industrial experience

  1. Petroleum Marketing. Selling Automotive Products and Services.

    Science.gov (United States)

    Luter, Robert R.

    This textbook contains material for the individualized instruction of students training for careers in service stations; automotive, tire, battery, and accessory retail stores; oil jobbers and petroleum product wholesalers, or any wholesale or retail establishment that sells automotive products and services. Included among the topics addressed in…

  2. Automotive Thermoelectric Waste Heat Recovery

    Science.gov (United States)

    Meisner, Gregory P.

    2015-03-01

    Considerable fuel energy, as much as 70%, is not converted to useful work by internal combustion engines but is instead rejected as waste heat, and more than half of the waste heat, nearly 40% of fuel energy, is contained in vehicle exhaust gas. This provides an opportunity to recover some of the wasted fuel energy and convert it from heat into useful work, subject to the laws of thermodynamics, and thereby improve vehicle energy efficiency. Thermoelectric (TE) materials have been extensively researched and TE devices are now being developed for operation at high temperatures corresponding to automotive exhaust gases for direct solid-state conversion of heat into electricity. This has stimulated substantial progress in the development of practical TE generator (TEG) systems for large-scale commercialization. A significant enabler of this progress has been the US Department of Energy's Vehicle Technologies Program through funding for low cost solutions for automotive TE waste heat recovery to improve fuel economy. Our current project at General Motors has culminated in the identification of the potential supply chain for all components and assembly of an automotive TEG. A significant focus has been to develop integrated and iterative modeling tools for a fully optimized TEG design that includes all components and subsystems (TE modules, heat exchangers, thermal interfaces, electrical interconnects, power conditioning, and vehicle integration for maximal use of TEG power). We have built and tested a new, low-cost Initial TEG prototype based on state-of-the-art production-scale skutterudite TE modules, novel heat exchanger designs, and practical solutions to the many technical challenges for optimum TEG performance. We will use the results for our Initial TEG prototype to refine our modeling and design tools for a Final automotive TEG system prototype. Our recent results will be presented. Thanks to: J.R. Salvador, E.R. Gundlach, D. Thompson, N.K. Bucknor, M

  3. The mechanics of PLGA nanofiber scaffolds with biomimetic gradients in mineral for tendon-to-bone repair.

    Science.gov (United States)

    Lipner, J; Liu, W; Liu, Y; Boyle, J; Genin, G M; Xia, Y; Thomopoulos, S

    2014-12-01

    along the length of the scaffolds, and Raman spectroscopic analysis revealed that the mineral produced was hydroxylapatite. Mechanical testing showed that the stiffness gradient using the new method was significantly steeper. By analyzing the scaffolds using micromechanical modeling techniques and extrapolating from our experimental results, we present evidence that the new mineralization protocol has the potential to achieve levels of stiffness adequate to contribute to enhanced repair of tendon-to-bone attachments.

  4. Potential of human γD-crystallin for hair damage repair: insights into the mechanical properties and biocompatibility.

    Science.gov (United States)

    Ribeiro, A; Matamá, T; Cruz, C F; Gomes, A C; Cavaco-Paulo, A M

    2013-10-01

    The objective of this work was to develop a new strategy to physically 'repair' chemically damaged hair. Hence the human eye γD-crystallin, a protein from the superfamily characterized structurally by the Greek key motif, was studied. The human γD-crystallin was chosen based on the ability of proteins belonging to this superfamily to be involved in the coating of specific structures. Two crystallins were used on the study, the wild type (Protein Data Bank ID: 1HK0) and the mutant protein. The mutant form was intended to induce a strong and quick protein polymerization as well to have new possible points of anchorage to hair. The ability of both crystallins to bind to damaged hair and even penetrate into its cortex was checked by fluorescence microscopy, confocal microscopy and scanning electron microscopy. Furthermore the reinforcement of hair mechanical resistance, the potential cytotoxic/inflammatory effect of crystallins were studied in order to have a fully comprehension about the protein based formulation. Although the chemical over-bleaching treatment induced a decrease of 20% on the resistance of the hair, the crystallins which bind and penetrate the hair fibre were able to recover and even to improve its mechanical properties when compared to the virgin hair. Moreover none of the crystallins displayed a toxic effect in fibroblasts for all the range of tested concentrations upon 72 h of exposure. The active aggregation process of mutant crystallin induced an inflammatory response in fibroblasts in the first 24 h of contact, measured by the amount of released pro-inflammatory cytokine IL-6 to the medium. In contrast contact with wild type crystallin did not lead to significant inflammation. Outcome from protein formulation characterization supports the hypothesis that the γD-crystallin it is able to recover and improve the mechanical properties of chemical damaged hair. Therefore it can be considered as a very promising strengthening agent for the

  5. Plants Possess a Cyclic Mitochondrial Metabolic Pathway similar to the Mammalian Metabolic Repair Mechanism Involving Malate Dehydrogenase and l-2-Hydroxyglutarate Dehydrogenase.

    Science.gov (United States)

    Hüdig, Meike; Maier, Alexander; Scherrers, Isabell; Seidel, Laura; Jansen, Erwin E W; Mettler-Altmann, Tabea; Engqvist, Martin K M; Maurino, Veronica G

    2015-09-01

    Enzymatic side reactions can give rise to the formation of wasteful and toxic products that are removed by metabolite repair pathways. In this work, we identify and characterize a mitochondrial metabolic repair mechanism in Arabidopsis thaliana involving malate dehydrogenase (mMDH) and l-2-hydroxyglutarate dehydrogenase (l-2HGDH). We analyze the kinetic properties of both A. thaliana mMDH isoforms, and show that they produce l-2-hydroxyglutarate (l-2HG) from 2-ketoglutarate (2-KG) at low rates in side reactions. We identify A. thaliana l-2HGDH as a mitochondrial FAD-containing oxidase that converts l-2HG back to 2-KG. Using loss-of-function mutants, we show that the electrons produced in the l-2HGDH reaction are transferred to the mitochondrial electron transport chain through the electron transfer protein (ETF). Thus, plants possess the biochemical components of an l-2HG metabolic repair system identical to that found in mammals. While deficiencies in the metabolism of l-2HG result in fatal disorders in mammals, accumulation of l-2HG in plants does not adversely affect their development under a range of tested conditions. However, orthologs of l-2HGDH are found in all examined genomes of viridiplantae, indicating that the repair reaction we identified makes an essential contribution to plant fitness in as yet unidentified conditions in the wild.

  6. Down-regulation of the Nucleotide Excision Repair gene XPG as a new mechanism of drug resistance in human and murine cancer cells

    Directory of Open Access Journals (Sweden)

    Geroni Cristina

    2010-09-01

    Full Text Available Abstract Background Drug resistance is one of the major obstacles limiting the activity of anticancer agents. Activation of DNA repair mechanism often accounts for increase resistance to cancer chemotherapy. Results We present evidence that nemorubicin, a doxorubicin derivative currently in clinical evaluation, acts through a mechanism of action different from classical anthracyclines, requiring an intact nucleotide excision repair (NER system to exert its activity. Cells made resistant to nemorubicin show increased sensitivity to UV damage. We have analysed the mechanism of resistance and discovered a previously unknown mechanism resulting from methylation-dependent silencing of the XPG gene. Restoration of NER activity through XPG gene transfer or treatment with demethylating agents restored sensitivity to nemorubicin. Furthermore, we found that a significant proportion of ovarian tumors present methylation of the XPG promoter. Conclusions Methylation of a NER gene, as described here, is a completely new mechanism of drug resistance and this is the first evidence that XPG gene expression can be influenced by an epigenetic mechanism. The reported methylation of XPG gene could be an important determinant of the response to platinum based therapy. In addition, the mechanism of resistance reported opens up the possibility of reverting the resistant phenotype using combinations with demethylating agents, molecules already employed in the clinical setting.

  7. Automotive Battery Modelling and Management

    Directory of Open Access Journals (Sweden)

    N. M. Hammad

    2014-06-01

    Full Text Available The estimation of vehicle battery performance is typically addressed by testing the battery under specific operation conditions by using a model to represent the test results. Approaches for representing test results range from simple statistical models to neural networks to complex, physics-based models. Basing the model on test data could be problematical when testing becomes impractical with many years life time tests. So, real time estimation of battery performance, an important problem in automotive applications, falls into this area. In vehicles it is important to know the state of charge of the batteries in order to prevent vehicle stranding and to ensure that the full range of the vehicle operation is exploited. In this paper, several battery models have studied including analytical, electrical circuits, stochastic and electro- chemical models. Valve Regulated Lead Acid “VRLA” battery has been modelled using electric circuit technique. This model is considered in the proposed Battery Monitoring System “BMS”. The proposed BMS includes data acquisition, data analysis and prediction of battery performance under a hypothetical future loads. Based on these criteria, a microprocessor based BMS prototype had been built and tested in automotive Lab,. The tests show promising results that can be used in industrial applications

  8. Development process of automotive microsensors

    Science.gov (United States)

    Tang, William C.

    1995-05-01

    The phased product development approach can be applied advantageously to develop and manufacture automotive microsensors. The phased approach involves a multifunctional team from innovation to development to eventual production and maintenance phases. The key advantage of this approach is the shortened development cycle and fast product introduction, while minimizing waste of resources and lowering risk of product failure. When applied to the product cycles of automotive sensors based on micromachining technology, this approach elucidates several critical considerations. In particular, since industrial application of micromachining technology is still at the infant stage, standards and design rules are not firmly established. Therefore, several important activities must be initiated simultaneously from the start of the innovation phase, which proves to be crucial to the prudent decision of technology alternatives and sensor system configuration. The use of a multifunctional team, as mandated in the phased approach, enables coherent development and optimization of the sense element, the fabrication technology, the packaging approach, the interface circuit configuration, and design features that allow efficient test and assembly flow. Also, with intermediate milestones within each phase, risk assessment and necessary midcourse adjustment to technology trade- offs can be both timely and accurate. Accelerometers, one of the most developed micromachined sensors, serve as representative examples that illustrate how the phased approach can benefits the commercialization of the newly established and rapidly expanding field of micromechanics.

  9. Tendon repair

    Science.gov (United States)

    Repair of tendon ... Tendon repair can be performed using: Local anesthesia (the immediate area of the surgery is pain-free) ... a cut on the skin over the injured tendon. The damaged or torn ends of the tendon ...

  10. A Study of the Repair Mechanism in Japanese Conversation%日语会话的修正机制研究

    Institute of Scientific and Technical Information of China (English)

    赵刚; 贾琦

    2012-01-01

    本文主要考察日语会话中常见的修正现象,探讨了修正机制和特征。首先在Schegloff,Jefferson&Sacks(1977)的基础上,对修正的定义和结构特征进行了补充。对桥内(1999)的修正内容分类进行了完善,提出了“信息补充修正”这一分类,首次从阻碍源和修正的照应关系,以及从会话管理的视点等方面对修正进行了详细的分类和深入的考察,明确了修正在互动行为中的功能和作用。%This paper mainly focuses on the repair phenomenon which is most common in Japanese daily conversation, discussing the repair mechanism and its features. Firstly, the paper takes its basis from the research of Schegloff, Jefferson & Sacks (1977) and supplements the definition of repair and its structural characteristics. In addition, we perfect the repair content classification system put forward by Hashiuchi (1999) and describe a new classification system called "information supplement repair". Moreover, this paper details the classification system from the aspect of the source of trouble and deeply examines the revision of the anaphoric relationship and conversation management for the first time. Thus, the function of repair in interactive behavior is made clear through the above analysis

  11. Mockup Didatic Set for Students Development in Automotive Electronic

    Directory of Open Access Journals (Sweden)

    Fabio Delatore

    2013-05-01

    Full Text Available The automotive engineering education area, specifically on internal combustion engine, requires the use of suitable systems, capable to simulate, test and obtain specifics data from its operation. Automotive engines are so complex due to it is a mix of engineering subjects, so, a mockup was created to help its study. The mockup is an exactly the same engine that equips a vehicle, but assembled in a mechanical base, equipped with all the necessary components for running it up. The objective of this work is to develop a mockup with a suitable Electronic Control Unit (ECU board, in order to obtain the sensors/actuators signals from the engine and control some important engine functions by using an external ECU, so that the students may test their own strategies, compare with the original ECU.

  12. DNA repair protocols

    DEFF Research Database (Denmark)

    Bjergbæk, Lotte

    In its 3rd edition, this Methods in Molecular Biology(TM) book covers the eukaryotic response to genomic insult including advanced protocols and standard techniques in the field of DNA repair. Offers expert guidance for DNA repair, recombination, and replication. Current knowledge of the mechanisms...... that regulate DNA repair has grown significantly over the past years with technology advances such as RNA interference, advanced proteomics and microscopy as well as high throughput screens. The third edition of DNA Repair Protocols covers various aspects of the eukaryotic response to genomic insult including...... recent advanced protocols as well as standard techniques used in the field of DNA repair. Both mammalian and non-mammalian model organisms are covered in the book, and many of the techniques can be applied with only minor modifications to other systems than the one described. Written in the highly...

  13. Mechanical and Permeability Characteristics of Latex-Modified Pre-Packed Pavement Repair Concrete as a Function of the Rapid-Set Binder Content

    Directory of Open Access Journals (Sweden)

    Jae-Woong Han

    2015-10-01

    Full Text Available We evaluated the strength and durability characteristics of latex-polymer-modified, pre-packed pavement repair concrete (LMPPRC with a rapid-set binder. The rapid-set binder was a mixture of rapid-set cement and silica sand, where the fluidity was controlled using a latex polymer. The resulting mix exhibited a compressive strength of ¥21 MPa and a flexural strength of ¥3.5 MPa after 4 h of curing (i.e., the traffic opening term for emergency repairs of pavement. The ratio of latex polymer to rapid-set binder material was varied through 0.40, 0.33, 0.29, and 0.25. Mechanical characterization revealed that the mechanical performance, permeability, and impact resistance increased as the ratio of latex polymer to rapid-set binder decreased. The mixture exhibited a compressive strength of ¥21 MPa after 4 h when the ratio of latex polymer to rapid-set binder material was ¤0.29. The mixture exhibited a flexural strength of ¥3.5 MPa after 4 h when the ratio of latex polymer to rapid-set binder material was ¤0.33. The permeability resistance to chloride ions satisfied 2000 C after 7 days of curing for all ratios. The ratio of latex polymer to rapid-set binder material that satisfied all conditions for emergency pavement repair was ¤0.29.

  14. Effects of the heat input in the mechanical integrity of the welding joints welded by GMAW and LBW process in Transformation Induced Plasticity steel (TRIP used in the automotive industry

    Directory of Open Access Journals (Sweden)

    Victor H. López Cortéz

    2010-09-01

    Full Text Available In this work an Advanced High Strength Steel (AHSS sheet of the Transformation Induced Plasticity (TRIP type currently employed in the automotive sector was welded using a Gas Metal Arc Welding (GMAW and a CO2 Laser Beam Welding (LBW processes. The mechanical properties of welded tensile specimens including microhardness were determined and the results were related to the exhibited microstructures. It was found that LBW lead to relatively high hardness in the fusion zone (FZ indicating that the resultant microstructure was predominantly martensite. In the Heat Affected Zone (HAZ, a mixture of phases consisting of bainite and ferrite was present. Similar phase mixtures were found in the HAZ and Fusion Zone (FZ of the GMAW samples. The exhibited microstructure did not result in mechanical degradation when the GMAW specimens were tested in tension as all the fractures occurred in the BM. In contrast, the region adjacent to the HAZ of most tensile specimens welded using LBW failed by brittle cleavage. Apparently, in this region tempering effects due to heat dissipation in the LBW process promoted carbide growth and a relatively coarse microstructure. No embrittlement was found that could be associated with the development of martensite.Neste trabalho, uma chapa de aço de alta resistência (AHSS - Advanced High Strength Steel tipo TRIP (Transformation Induced Plasticity empregado atualmente no setor automotivo foi soldado usando o processo de soldagem a arco com arame solido sob proteção gasosa (GMAW e soldagem com LASER de CO2 (LBW. As propriedades mecânicas das amostras soldadas quanto a tração e microdureza foram determinadas e os resultados foram relacionados com as microestruturas apresentadas. Verificou-se que a solda com LBW chegou a valores realtivamente altos de dureza na zona fundida (ZF, indicando que a microestrutura resultante foi predominantemente de martensita. Na zona termicamente afetadas (ZTA, encontrou-se uma mistura de fases

  15. Collagen insulated from tensile damage by domains that unfold reversibly: in situ X-ray investigation of mechanical yield and damage repair in the mussel byssus.

    Science.gov (United States)

    Harrington, Matthew J; Gupta, Himadri S; Fratzl, Peter; Waite, J Herbert

    2009-07-01

    The byssal threads of the California mussel, Mytilus californianus, are highly hysteretic, elastomeric fibers that collectively perform a holdfast function in wave-swept rocky seashore habitats. Following cyclic loading past the mechanical yield point, threads exhibit a damage-dependent reduction in mechanical performance. However, the distal portion of the byssal thread is capable of recovering initial material properties through a time-dependent healing process in the absence of active cellular metabolism. Byssal threads are composed almost exclusively of multi-domain hybrid collagens known as preCols, which largely determine the mechanical properties of the thread. Here, the structure-property relationships that govern thread mechanical performance are further probed. The molecular rearrangements that occur during yield and damage repair were investigated using time-resolved in situ wide-angle X-ray diffraction (WAXD) coupled with cyclic tensile loading of threads and through thermally enhanced damage-repair studies. Results indicate that the collagen domains in byssal preCols are mechanically protected by the unfolding of sacrificial non-collagenous domains that refold on a slower time-scale. Time-dependent healing is primarily attributed to stochastic recoupling of broken histidine-metal coordination complexes.

  16. Plants as concept generators for biomimetic light-weight structures with variable stiffness and self-repair mechanisms

    Institute of Scientific and Technical Information of China (English)

    Thomas Speck; Tom Masselter; Bettina Prüm; Olga Speck; Rolf Luchsinger; Siegfried Fink

    2004-01-01

    Plants possess many structural and functional properties that have a high potential to serve as concept generators for the production of biomimetic technical materials and structures. We present data on two features of plants (variable stiffness due to pressure changes in cellular structures and rapid self-repair functions) that may be used as models for biomimetic projects.

  17. Prospects for MEMS in the Automotive Industry

    Directory of Open Access Journals (Sweden)

    Richard DIXON

    2007-12-01

    Full Text Available An automotive sector as a growth market for MEMS sensors is analyzed in the article. The automotive sector accounted for $1.6 billion, making this the second biggest opportunity after IT peripherals and inkjet print heads. By 2011 the market will top $2.2 billion, a CAGR of around 7%. The main applications in revenues terms are, in order, pressure sensors, gyroscopes, accelerometers and flow sensors and this will remain so for the foreseeable future. Automotive companies are forced to innovate as a result of competition and price pressures.

  18. Automotive Stirling engine development program

    Science.gov (United States)

    Ernst, W.; Richey, A.; Farrell, R.; Riecke, G.; Smith, G.; Howarth, R.; Cronin, M.; Simetkosky, M.; Meacher, J.

    1986-01-01

    This is the ninth Semiannual Technical Progress Report prepared under the Automotive Stirling Engine Development Program. It covers the twenty-eighth and twenty-ninth quarters of activity after award of the contract. Quarterly Technical Progress Reports related program activities from the first through the thirteenth quarters; thereafter, reporting was changed to a Semiannual format. This report summarizes the study of higher-power kinematic Stirling engines for transportation use, development testing of Mod I Stirling engines, and component development activities. Component development testing included successful conical fuel nozzle testing and functional checkout of Mod II controls and auxiliaries on Mod I engine test beds. Overall program philosophy is outlined and data and test results are presented.

  19. Left ventricular mechanics in repaired tetralogy of Fallot with and without pulmonary valve replacement: analysis by three-dimensional speckle tracking echocardiography.

    Directory of Open Access Journals (Sweden)

    Shu-Na Li

    Full Text Available BACKGROUND: Altered septal curvature and left ventricular (LV geometry secondary to right ventricular (RV dilation render two-dimensional assessment of LV mechanics difficult in repaired tetralogy of Fallot (TOF patients. The novel three-dimensional (3D speckle tracking echocardiography enables comprehensive evaluation of true 3D LV mechanics. METHODS AND RESULTS: Seventy-six patients aged 23.6 ± 8.3 years, 55 with isolated repair (group I and 21 with subsequent pulmonary valve replacement (group II, and 34 healthy controls were studied. Three-dimensional volume datasets were acquired for assessment of LV global and regional 3D strain, systolic dyssynchrony index (SDI, twist, twist gradient (twist/LV length, and ejection fraction. A global performance index was calculated as (global 3D strain•twist gradient/SDI. The septal curvature and LV eccentricity were determined from the mid-ventricular short-axis. Compared with controls, group I and II patients had significantly reduced LV global 3D strain, LV twist, twist gradient, septal curvature, and global performance index, and greater LV systolic and diastolic eccentricity and SDI (all p<0.05. All but the four apical LV segments in patients had reduced regional 3D strain compared with controls (all p<0.05. Septal curvature correlated with LV global 3D strain (r=0.41, p<0.001, average septal strain (r=0.38, p<0.001, twist (r=0.32, p<0.001, twist gradient (r=0.33, p<0.001, and global performance index (r=0.43, p<0.001. CONCLUSIONS: Adverse 3D LV mechanics as characterized by impaired global and regional 3D systolic strain, mechanical dyssynchrony, and reduced twist is related to reduced septal curvature in repaired TOF patients with and without pulmonary valve replacement.

  20. Nano-crystalline P/M aluminium for automotive applications

    Science.gov (United States)

    Hummert, K.; Schattevoy, R.; Broda, M.; Knappe, M.; Beiss, P.; Klubberg, F.; Schubert, T. H.; Leuschner, R.

    2009-01-01

    The reduction of total vehicle weight and lowering of moving masses within the engine are key elements to overcome future emission challenges of the automotive industry. Within a German BMBF funded project the melt spinning technology will be driven to a series production status. The very fast cooling condition of the melt leads to a nano-structure of the aluminium material. This results in new material properties of known alloys. The strength increases dramatically without lowered forming behaviour. With this process the freedom of designing complex alloys is very flexible. Different alloys have been investigated for several applications, where high strength at room and elevated temperatures and/or high wear resistance is required. This paper presents some results regarding the processing, microstructure and mechanical properties of a developed Al-Ni-Fe alloy. This joined research project with partners from the automotive industry as well as automotive suppliers and universities is funded by the German BMBF "NanoMobile" Program under Project number 03X3008.

  1. Experimental and numerical analysis of automotive gearbox rattle noise

    Science.gov (United States)

    Kadmiri, Younes; Rigaud, Emmanuel; Perret-Liaudet, Joël; Vary, Laurence

    2012-06-01

    The aim of this work is to characterize the rattle noise of automotive gearboxes, resulting from impacts between toothed wheels of unselected gear ratios. These stereo-mechanical impacts are modeled by a coefficient of restitution which describes damping during the squeezing of the lubricant film for approaching surfaces, and the elastic deformation of impacting bodies. The dynamic response of the loose gear first depends on the design parameters and the engine operating conditions. The unknown parameters are the drag torque and the coefficient of restitution. They are identified experimentally through implementation of two optical encoders in an actual automotive gearbox and the operation of a specific test bench which replicates the automotive power train. Models of the different drag torque sources are validated from analysis of the free damped response of the driveline. The coefficient of restitution and its probability density function are measured from experiments under stationary operating conditions. A nonlinear model is built. The dynamic response of the loose gear depends on the dimensionless backlash, the coefficient of restitution and a dimensionless parameter proposed to describe the rattle excitation level. Experiments under controlled excitation are performed to validate the assumptions, to confirm the ability of the parameter proposed to describe the rattle noise threshold, and to characterize the dynamic response. The nonlinear model predictions are fitted with the drag torque and coefficient of restitution previously identified. They are compared with measurements to demonstrate the ability of the model to predict gear rattle for any loose gear, any gearbox and any operating condition.

  2. Bladder exstrophy repair

    Science.gov (United States)

    Bladder birth defect repair; Everted bladder repair; Exposed bladder repair; Repair of bladder exstrophy ... Bladder exstrophy repair involves two surgeries. The first surgery is to repair the bladder and the second one is to attach ...

  3. Effects of Repair Weld of Reactor Pressure Vessel Upper Head Control Rod Drive Mechanism Penetration Nozzle on J-Groove Weldment Using Finite Element Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ju Hee; Yoo, Sam Hyeon [Korea Military Academy, Seoul (Korea, Republic of); Kim, Yun Jae [Korea University, Seoul (Korea, Republic of)

    2014-06-15

    In pressurized water reactors, the upper head of the reactor pressure vessel (RPV) contains numerous control rod drive mechanism (CRDM) nozzles. These nozzles are fabricated by welding after being inserted into the RPV head with a room temperature shrink fit. The tensile residual stresses caused by this welding are a major factor in primary water stress corrosion cracking (PWSCC). Over the last 15 years, the incidences of cracking in alloy 600 CRDM nozzles have increased significantly. These cracks are caused by PWSCC and have been shown to be driven by the welding residual stresses and operational stresses in the weld region. Various measures are being sought to overcome these problems. The defects resulting from the welding process are often the cause of PWSCC acceleration. Therefore, any weld defects found in the RPV manufacturing process are immediately repaired by repair welding. Detailed finite element simulations for the Korea Nuclear Reactor Pressure Vessel were conducted in order to predict the magnitudes of the repair weld residual stresses in the tube materials.

  4. The spliceosome U2 snRNP factors promote genome stability through distinct mechanisms; transcription of repair factors and R-loop processing.

    Science.gov (United States)

    Tanikawa, M; Sanjiv, K; Helleday, T; Herr, P; Mortusewicz, O

    2016-12-19

    Recent whole-exome sequencing of malignancies have detected recurrent somatic mutations in U2 small nuclear ribonucleoprotein complex (snRNP) components of the spliceosome. These factors have also been identified as novel players in the DNA-damage response (DDR) in several genome-wide screens and proteomic analysis. Although accumulating evidence implies that the spliceosome has an important role in genome stability and is an emerging hallmark of cancer, its precise role in DNA repair still remains elusive. Here we identify two distinct mechanisms of how spliceosome U2 snRNP factors contribute to genome stability. We show that the spliceosome maintains protein levels of essential repair factors, thus contributing to homologous recombination repair. In addition, real-time laser microirradiation analysis identified rapid recruitment of the U2 snRNP factor SNRPA1 to DNA-damage sites. Functional analysis of SNRPA1 revealed a more immediate and direct role in preventing R-loop-induced DNA damage. Our present study implies a complex interrelation between transcription, mRNA splicing and the DDR. Cells require rapid spatio-temporal coordination of these chromatin transactions to cope with various forms of genotoxic stress.

  5. INFLUENCE OF AUTOMOTIVE CLUSTERS IN REGIONAL DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Constantin BORDEI

    2014-11-01

    Full Text Available This paper proposes an overview of the evolution in the automotive sector in the process of regional development. The fundamental changes made by the component supplier sector improved the regional development and manufacturing process. Automotive industry is one of the modern sectors in many countries that benefits of a high technology impact and creates jobs that reduces unemployment across Europe. The auto industry changed cities, regions and countries into poles of development and it becomes more and more efficient. The high foreign direct investments from the automotive sector play an important role in regional development process. Continuous changes are being made in the economy, society, and company; in conclusion the automotive clusters will always be a subject of analysis.

  6. Fatal exit the automotive black box debate

    CERN Document Server

    Kowalick, Tom

    2005-01-01

    "Fatal Exit: The Automotive Black Box Debate cuts through thirty years of political wrangling and institutional biases to provide an argument for the Motor Vehicle Event Data Recorder (MVEDR). This automotive equivalent of an airplane's flight recorder or black box is intended to solve the mysteries of car crashes and improve the safety of our roads. The reader is taken inside the automotive industry and the government highway safety establishment to foster an understanding of the politics and the positions on all sides of this safety debate. The author takes an unbiased approach, chronologically presenting each argument and uncovering the agendas and mandates of each of the stakeholders." "This publication is essential reading for all consumers who need to have their voices heard on this critical issue, as well as for attorneys, public safety advocates, public policy administrators, engineers, automotive professionals, journalists, and insurance executives."--Jacket.

  7. Nonlinear estimation and control of automotive drivetrains

    CERN Document Server

    Chen, Hong

    2014-01-01

    Nonlinear Estimation and Control of Automotive Drivetrains discusses the control problems involved in automotive drivetrains, particularly in hydraulic Automatic Transmission (AT), Dual Clutch Transmission (DCT) and Automated Manual Transmission (AMT). Challenging estimation and control problems, such as driveline torque estimation and gear shift control, are addressed by applying the latest nonlinear control theories, including constructive nonlinear control (Backstepping, Input-to-State Stable) and Model Predictive Control (MPC). The estimation and control performance is improved while the calibration effort is reduced significantly. The book presents many detailed examples of design processes and thus enables the readers to understand how to successfully combine purely theoretical methodologies with actual applications in vehicles. The book is intended for researchers, PhD students, control engineers and automotive engineers. Hong Chen is a professor at the State Key Laboratory of Automotive Simulation and...

  8. INFLUENCE OF AUTOMOTIVE CLUSTERS IN REGIONAL DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Constantin BORDEI

    2014-11-01

    Full Text Available This paper proposes an overview of the evolution in the automotive sector in the process of regional development. The fundamental changes made by the component supplier sector improved the regional development and manufacturing process. Automotive industry is one of the modern sectors in many countries that benefits of a high technology impact and creates jobs that reduces unemployment across Europe. The auto industry changed cities, regions and countries into poles of development and it becomes more and more efficient. The high foreign direct investments from the automotive sector play an important role in regional development process. Continuous changes are being made in the economy, society, and company; in conclusion the automotive clusters will always be a subject of analysis.

  9. 78 FR 36633 - National Automotive Sampling System

    Science.gov (United States)

    2013-06-18

    ... National Highway Traffic Safety Administration National Automotive Sampling System AGENCY: National Highway Traffic Safety Administration (NHTSA), Department of the Transportation (DOT). ACTION: Notice of public... regarding vehicle design and traffic safety. The NASS system currently has two components: the...

  10. 77 FR 37471 - National Automotive Sampling System

    Science.gov (United States)

    2012-06-21

    ... National Highway Traffic Safety Administration National Automotive Sampling System AGENCY: National Highway Traffic Safety Administration (NHTSA), Department of Transportation (DOT). ACTION: Notice and request for... make informed regulatory, program, and policy decisions regarding vehicle design and traffic...

  11. Sustainable automotive energy system in China

    CERN Document Server

    CAERC, Tsinghua University

    2014-01-01

    This book identifies and addresses key issues of automotive energy in China. It covers demography, economics, technology and policy, providing a broad perspective to aid in the planning of sustainable road transport in China.

  12. Graduate Automotive Technology Education (GATE) Program: Center of Automotive Technology Excellence in Advanced Hybrid Vehicle Technology at West Virginia University

    Energy Technology Data Exchange (ETDEWEB)

    Nigle N. Clark

    2006-12-31

    This report summarizes the technical and educational achievements of the Graduate Automotive Technology Education (GATE) Center at West Virginia University (WVU), which was created to emphasize Advanced Hybrid Vehicle Technology. The Center has supported the graduate studies of 17 students in the Department of Mechanical and Aerospace Engineering and the Lane Department of Computer Science and Electrical Engineering. These students have addressed topics such as hybrid modeling, construction of a hybrid sport utility vehicle (in conjunction with the FutureTruck program), a MEMS-based sensor, on-board data acquisition for hybrid design optimization, linear engine design and engine emissions. Courses have been developed in Hybrid Vehicle Design, Mobile Source Powerplants, Advanced Vehicle Propulsion, Power Electronics for Automotive Applications and Sensors for Automotive Applications, and have been responsible for 396 hours of graduate student coursework. The GATE program also enhanced the WVU participation in the U.S. Department of Energy Student Design Competitions, in particular FutureTruck and Challenge X. The GATE support for hybrid vehicle technology enhanced understanding of hybrid vehicle design and testing at WVU and encouraged the development of a research agenda in heavy-duty hybrid vehicles. As a result, WVU has now completed three programs in hybrid transit bus emissions characterization, and WVU faculty are leading the Transportation Research Board effort to define life cycle costs for hybrid transit buses. Research and enrollment records show that approximately 100 graduate students have benefited substantially from the hybrid vehicle GATE program at WVU.

  13. Evidence for repair of ultraviolet light-damaged herpes virus in human fibroblasts by a recombination mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Hall, J.D.; Featherston, J.D.; Almy, R.E.

    1980-09-01

    Human cells were either singly or multiply infected with herpes simplex virus (HSV-1) damaged by ultraviolet (uv) light, and the fraction of cells able to produce infectious virus was measured. The fraction of virus-producing cells was considerably greater for multiply infected cells than for singly infected cells at each uv dose examined. These high survival levels of uv-irradiated virus in multiply infected cells demonstrated that multiplicity-dependent repair, possibly due to genetic exchanges between damaged HSV-1 genomes, was occurring in these cells. To test whether uv light is recombinogenic for HSV-1, the effect of uv irradiation on the yield of temperature-resistant viral recombinants in cells infected with pairs of temperature-sensitive mutants was also investigated. The results of these experiments showed that the defective functions in these mutant host cells are not required for multiplicity-dependent repair or uv-stimulated viral recombination in herpes-infected cells.

  14. INTERNAL REPAIR OF PIPELINES

    Energy Technology Data Exchange (ETDEWEB)

    Bill Bruce; Nancy Porter; George Ritter; Matt Boring; Mark Lozev; Ian Harris; Bill Mohr; Dennis Harwig; Robin Gordon; Chris Neary; Mike Sullivan

    2005-07-20

    liners, indicating that this type of liner is only marginally effective at restoring the pressure containing capabilities of pipelines. Failure pressures for larger diameter pipe repaired with a semi-circular patch of carbon fiber-reinforced composite lines were also marginally greater than that of a pipe section with un-repaired simulated damage without a liner. These results indicate that fiber reinforced composite liners have the potential to increase the burst pressure of pipe sections with external damage Carbon fiber based liners are viewed as more promising than glass fiber based liners because of the potential for more closely matching the mechanical properties of steel. Pipe repaired with weld deposition failed at pressures lower than that of un-repaired pipe in both the virgin and damaged conditions, indicating that this repair technology is less effective at restoring the pressure containing capability of pipe than a carbon fiber-reinforced liner repair. Physical testing indicates that carbon fiber-reinforced liner repair is the most promising technology evaluated to-date. In lieu of a field installation on an abandoned pipeline, a preliminary nondestructive testing protocol is being developed to determine the success or failure of the fiber-reinforced liner pipeline repairs. Optimization and validation activities for carbon-fiber repair methods are ongoing.

  15. 机械式清除冰雪机械的保养和检修%Discussion on maintenance and repair of mechanical snow removing machinery

    Institute of Scientific and Technical Information of China (English)

    张健

    2013-01-01

      由于我国的气候原因,很多城市在冬季来临时道路上会积下很多冰雪,影响道路安全。机械除雪的方法因为基本没有副作用,所以被广泛使用,而对机械式清除冰雪机械的保养和检修也越来越被人们所重视。%  Because of climate in our country, many cities in the winter comes, accumulated a lot of snow and ice on roads, impact on road safety. Mechanical snow removal method for basic have no side effects, so widely used, and the me-chanical removal of snow and ice mechanical maintenance and repair is becoming more and more attention by people.

  16. Low Dose Radiation-Induced Genome and Epigenome Instability Symposium and Epigenetic Mechanisms, DNA Repair, and Chromatin Symposium at the EMS 2008 Annual Meeting - October 2008

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, William F; Kovalchuk, Olga; Dolinoy, Dana C; Dubrova, Yuri E; Coleman, Matthew A; Schär, Primo; Pogribny, Igor; Hendzel, Michael

    2010-02-19

    The Low Dose Radiation Symposium thoughtfully addressed ionizing radiation non-mutational but transmissable alterations in surviving cells. Deregulation of epigenetic processes has been strongly implicated in carcinogenesis, and there is increasing realization that a significant fraction of non-targeted and adaptive mechanisms in response to ionizing radiation are likely to be epigenetic in nature. Much remains to be learned about how chromatin and epigenetic regulators affect responses to low doses of radiation, and how low dose radiation impacts other epigenetic processes. The Epigenetic Mechanisms Symposium focused on on epigenetic mechanisms and their interplay with DNA repair and chromatin changes. Addressing the fact that the most well understood mediators of epigenetic regulation are histone modifications and DNA methylation. Low levels of radiation can lead to changes in the methylation status of certain gene promoters and the expression of DNA methyltransferases, However, epigenetic regulation can also involve changes in higher order chromosome structure.

  17. Advanced high strength steels for automotive industry

    Directory of Open Access Journals (Sweden)

    Galán, J.

    2012-04-01

    Full Text Available The car industry is facing pressure because of the growing demand for more fuel-efficient passenger cars. In order to limit energy consumption and air pollution the weight of the carbody has to be reduced. At the same time, high levels of safety have to be guaranteed. In this situation, the choice of material becomes a key decision in car design. As a response to the requirements of the automotive sector, high strength steels and advanced high strength steels have been developed by the steel industry. These modern steel grades offer an excellent balance of low cost, light weight and mechanical properties.

    La industria del automóvil se enfrenta a una creciente demanda de vehículos de pasajeros más eficientes. Con el fin de disminuir el consumo de energía y la contaminación ambiental, el peso del vehículo tiene que ser reducido, al mismo tiempo que se garantizan altos niveles de seguridad. Ante esta situación, la elección de material se convierte en una decisión crucial en el diseño del vehículo. Como respuesta a las necesidades del sector automovilístico, nuevos aceros avanzados y de alta resistencia, han sido desarrollados por la industria siderúrgica. Dichos tipos de acero ofrecen un excelente equilibrio de precio, peso y propiedades mecánicas.

  18. Future automotive materials: Evolution or revolution

    Science.gov (United States)

    Beardmore, P.

    1990-01-01

    An exciting era is evolving in the application of new materials technologies to automotive applications. The desire on the part of the automobile industry to completely satisfy the customers while concurrently meeting increasing demands and regulations for stringent emission control and fuel efficiency is opening a plethora of opportunities for new materials. In many cases, materials solutions are the only mechanisms for resolving some of the upcoming issues. The materials scientist and engineer will therefore have a primary role to play and will assume a position of significance hithertofore unseen in the automobile industry. The nature of the industry dictates that changes are primarily evolutionary with respect to chronology but nevertheless some of the future material changes will be revolutionary in nature. This presentation will treat three primary systems of the vehicle separately, based on the different materials approaches which will be adopted. These areas are: (1) skin panels, (2) structures, and (3) powertrains. The competition between a variety of new materials in these 3 systems will be discussed in detail with the various tradeoffs being outlined. Amongst the more prominent of the new breed of materials will be new steel technologies, structural plastics (FRP), aluminum alloys (conventional and rapidly solidified), titanium alloys, metal matrix composites and smart materials (electrorheological fluids, etc.). The pace of development and application is accelerating rapidly and the impetus is likely to increase.

  19. EXPERIMENTAL STUDY ON HIGH-SPEED CHARACTERISTICS OF AUTOMOTIVE ENGINE OIL-PUMP CHAIN

    Institute of Scientific and Technical Information of China (English)

    CHENG Yabing; MENG Fanzhong; XU Hanxue; WU Jianming

    2007-01-01

    The high-speed multi-cycle impact and speed, load fluctuant characteristics of a kind of narrow-width automotive engine oil-pump chain 06BN-1 are studied through engine assembly and road-drive tests to satisfy the light-weight demand of engine. The worn surface morphologies of rubbing area between pin, bush and roller are also analyzed based on scanning electron microscope. The results show that the main wear mechanism of automotive engine oil-pump chain is fatigue wear, and it's failure mechanism is the forming, extending and flaking of cracks on top layer of pin and bush. Pin and bush both occurred cycle-soften phenomenon, and roller occurred cycle-harden. Fretting wear is one of the most important "fall to pieces" failure causes of automotive chain. Ensuring sufficient strength and plasticity of roller, as well as adopting suitable shaping technology are the effective methods to increase its resistance to multi-cycle impact.

  20. 75 FR 34170 - Plastic Omnium Automotive Exteriors, LLC, Anderson, SC; Plastic Omnium Automotive Exteriors, LLC...

    Science.gov (United States)

    2010-06-16

    ... Employment and Training Administration Plastic Omnium Automotive Exteriors, LLC, Anderson, SC; Plastic Omnium... Assistance on March 18, 2010, applicable to workers of Plastic Omnium Automotive Exteriors, LLC, Anderson... have occurred involving workers in support of the Anderson, South Carolina location of Plastic...

  1. INTERNAL REPAIR OF PIPELINES

    Energy Technology Data Exchange (ETDEWEB)

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; George Ritter; Bill Mohr; Matt Boring; Nancy Porter; Mike Sullivan; Chris Neary

    2004-12-31

    liners, indicating that this type of liner is only marginally effective at restoring the pressure containing capabilities of pipelines. Failure pressures for larger diameter pipe repaired with a semi-circular patch of carbon fiber-reinforced composite lines were also marginally greater than that of a pipe section with un-repaired simulated damage without a liner. These results indicate that fiber reinforced composite liners have the potential to increase the burst pressure of pipe sections with external damage Carbon fiber based liners are viewed as more promising than glass fiber based liners because of the potential for more closely matching the mechanical properties of steel. Pipe repaired with weld deposition failed at pressures lower than that of un-repaired pipe in both the virgin and damaged conditions, indicating that this repair technology is less effective at restoring the pressure containing capability of pipe than a carbon fiber-reinforced liner repair. Physical testing indicates that carbon fiber-reinforced liner repair is the most promising technology evaluated to-date. The first round of optimization and validation activities for carbon-fiber repairs are complete. Development of a comprehensive test plan for this process is recommended for use in the field trial portion of this program.

  2. CRISPR Technology Reveals RAD(51)-ical Mechanisms of Repair in Roundworms: An Educational Primer for Use with "Promotion of Homologous Recombination by SWS-1 in Complex with RAD-51 Paralogs in Caenorhabditis elegans".

    Science.gov (United States)

    Turcotte, Carolyn A; Andrews, Nicolas P; Sloat, Solomon A; Checchi, Paula M

    2016-11-01

    The mechanisms cells use to maintain genetic fidelity via DNA repair and the accuracy of these processes have garnered interest from scientists engaged in basic research to clinicians seeking improved treatment for cancer patients. Despite the continued advances, many details of DNA repair are still incompletely understood. In addition, the inherent complexity of DNA repair processes, even at the most fundamental level, makes it a challenging topic. This primer is meant to assist both educators and students in using a recent paper, "Promotion of homologous recombination by SWS-1 in complex with RAD-51 paralogs in Caenorhabditis elegans," to understand mechanisms of DNA repair. The goals of this primer are to highlight and clarify several key techniques utilized, with special emphasis on the clustered, regularly interspaced, short palindromic repeats technique and the ways in which it has revolutionized genetics research, as well as to provide questions for deeper in-class discussion.

  3. 浅谈现代煤炭企业机电设备维修%On Modern Coal Enterprises of Mechanical and Electrical Equipment Repairing

    Institute of Scientific and Technical Information of China (English)

    吕皋鸣

    2015-01-01

    In recent years,China's coal industry has been rapid developed,in order to ensure the safe production of coal enterprises to improve economic efficiency and electromechanical equipment can work stably, therefore, electrical and mechanical equipment repair management is becoming more and more important. This article from the electrical and mechanical equipment maintenance and coal play an important role in the production of each link, modify the equipment repair plan, deepen the staff technical training, to improve the equipment maintenance personnel business level as a priority task, strict implementation of equipment inspection system, to ensure the safe and stable operation of electrical equipment, the implementation of professional repair, improve the quality of maintenance etc, discusses reform measures of the modern coal enterprises in the production of electrical and mechanical equipment repair work.%近年来,我国煤炭产业得到快速发展,为了确保煤炭企业得以安全生产并提高经济效益,需要机电设备可以稳定工作,因此,机电设备的维修管理工作正变得越来越重要。从几个方面探讨了现代煤炭企业在生产中机电设备维修工作的改革措施:发挥煤炭机电设备的维护在生产各个环节的重要作用,修改设备维修方案;深化员工技术培训工作,把提高设备维护人员业务水平作为重点工作来抓;严格执行设备检查制度,来保障机电设备安全稳定运行;施行专业化维修,提高检修质量。

  4. Automotive Stirling Engine Development Project

    Science.gov (United States)

    Ernst, William D.; Shaltens, Richard K.

    1997-01-01

    The development and verification of automotive Stirling engine (ASE) component and system technology is described as it evolved through two experimental engine designs: the Mod 1 and the Mod 2. Engine operation and performance and endurance test results for the Mod 1 are summarized. Mod 2 engine and component development progress is traced from the original design through hardware development, laboratory test, and vehicle installation. More than 21,000 hr of testing were accomplished, including 4800 hr with vehicles that were driven more dm 59,000 miles. Mod 2 engine dynamometer tests demonstrated that the engine system configuration had accomplished its performance goals for power (60 kW) and efficiency (38.5%) to within a few percent. Tests with the Mod 2 engine installed in a delivery van demonstrated combined metro-highway fuel economy improvements consistent with engine performance goals and the potential for low emission levels. A modified version of the Mod 2 has been identified as a manufacturable design for an ASE. As part of the ASE project, the Industry Test and Evaluation Program (ITEP), NASA Technology Utilization (TU) project, and the industry-funded Stirling Natural Gas Engine program were undertaken to transfer ASE technology to end users. The results of these technology transfer efforts are also summarized.

  5. Gene expression analysis during recovery process indicates the mechanism for innate immune injury and repair from Coxsackievirus B3-induced myocarditis.

    Science.gov (United States)

    Yao, Hai-Lan; Song, Juan; Sun, Peng; Song, Qin-Qin; Sheng, Lin-Jun; Chi, Miao-Miao; Han, Jun

    2016-02-02

    To investigate the innate immune injury and repair mechanism during recovery from Coxsackievirus B3 (CVB3) induced myocarditis, we established an acute viral myocarditis recovery model by infecting BALB/c mice with CVB3. Histopathological examination of cardiac tissues after infection showed a gradual increase of myocardial injury to the maximum degree at 8 dpi (days post infection), followed by a recovery process with reduced viral replication. We also measured expression changes of innate immune genes in heart after 4, 8 and 12 days of infection using innate immune real-time PCR array. The results showed expression alterations in many Pattern Recognition Receptors (PRRs) genes upon CVB3 infection, which activated multiple important signaling pathways during recovery process. The expression of TLRs, RLRs, PKR and cytokines were strongly induced and reached the peak at 4 dpi in early myocarditis stage, followed by a gradual reduction in recovery stage, during which the levels were even lower than normal at 12 dpi. The strong correlation between cardiac histopathology score and chemokine expression level suggested that the chemokines might play a role in pathological changes during early myocarditis stage. In addition, we also found that both cell survival signaling pathways (AKT1, p38MAPK) and antiviral signaling pathways (IKKα/β/ε) were activated and promoted the recovery during late myocarditis stage. Altogether, our observations improved the understanding of formation and progression of the pathological lesions, as well as the repair mechanism for acute viral myocarditis.

  6. TGF-β reduces DNA ds-break repair mechanisms to heighten genetic diversity and adaptability of CD44+/CD24− cancer cells

    Science.gov (United States)

    Pal, Debjani; Pertot, Anja; Shirole, Nitin H; Yao, Zhan; Anaparthy, Naishitha; Garvin, Tyler; Cox, Hilary; Chang, Kenneth; Rollins, Fred; Kendall, Jude; Edwards, Leyla; Singh, Vijay A; Stone, Gary C; Schatz, Michael C; Hicks, James; Hannon, Gregory J; Sordella, Raffaella

    2017-01-01

    Many lines of evidence have indicated that both genetic and non-genetic determinants can contribute to intra-tumor heterogeneity and influence cancer outcomes. Among the best described sub-population of cancer cells generated by non-genetic mechanisms are cells characterized by a CD44+/CD24− cell surface marker profile. Here, we report that human CD44+/CD24− cancer cells are genetically highly unstable because of intrinsic defects in their DNA-repair capabilities. In fact, in CD44+/CD24− cells, constitutive activation of the TGF-beta axis was both necessary and sufficient to reduce the expression of genes that are crucial in coordinating DNA damage repair mechanisms. Consequently, we observed that cancer cells that reside in a CD44+/CD24− state are characterized by increased accumulation of DNA copy number alterations, greater genetic diversity and improved adaptability to drug treatment. Together, these data suggest that the transition into a CD44+/CD24− cell state can promote intra-tumor genetic heterogeneity, spur tumor evolution and increase tumor fitness. DOI: http://dx.doi.org/10.7554/eLife.21615.001 PMID:28092266

  7. Effect of glenohumeral abduction angle on the mechanical interaction between the supraspinatus and infraspinatus tendons for the intact, partial-thickness torn, and repaired supraspinatus tendon conditions.

    Science.gov (United States)

    Andarawis-Puri, Nelly; Kuntz, Andrew F; Ramsey, Matthew L; Soslowsky, Louis J

    2010-07-01

    Rotator cuff tears are difficult to manage because of the structural and mechanical inhomogeneity of the supraspinatus tendon. Previously, we showed that with the arm at the side, the supraspinatus and infraspinatus tendons mechanically interact such that conditions that increase supraspinatus tendon strain, such as load or full-thickness tears, also increase infraspinatus tendon strain. This suggests that the infraspinatus tendon may shield the supraspinatus tendon from further injury while becoming at increased risk of injury itself. In this study, the effect of glenohumeral abduction angle on the interaction between the two tendons was evaluated for supraspinatus tendon partial-thickness tears and two repair techniques. Principal strains were quantified in both tendons for 0 degrees , 30 degrees , and 60 degrees of glenohumeral abduction. Results showed that interaction between the two tendons is interrupted by an increase in abduction angle for all supraspinatus tendon conditions evaluated. Infraspinatus tendon strain was lower at 30 degrees and 60 degrees than at 0 degrees abduction angle. In conclusion, interaction between the supraspinatus and infraspinatus tendons is interrupted with increase in abduction angle. Additionally, 30 degrees abduction should be further evaluated for management of rotator cuff tears and repairs as it is the angle at which both supraspinatus and infraspinatus tendon strain is decreased.

  8. INTERNAL REPAIR OF PIPELINES

    Energy Technology Data Exchange (ETDEWEB)

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; George Ritter; Bill Mohr; Matt Boring; Nancy Porter; Mike Sullivan; Chris Neary

    2004-08-17

    , indicating that this type of liner is only marginally effective at restoring the pressure containing capabilities of pipelines. Failure pressures for larger diameter pipe repaired with a semi-circular patch of carbon fiber-reinforced composite lines were also marginally greater than that of a pipe section with un-repaired simulated damage without a liner. These results indicate that fiber reinforced composite liners have the potential to increase the burst pressure of pipe sections with external damage Carbon fiber based liners are viewed as more promising than glass fiber based liners because of the potential for more closely matching the mechanical properties of steel. Pipe repaired with weld deposition failed at pressures lower than that of un-repaired pipe in both the virgin and damaged conditions, indicating that this repair technology is less effective at restoring the pressure containing capability of pipe than a carbon fiber-reinforced liner repair. Physical testing indicates that carbon fiber-reinforced liner repair is the most promising technology evaluated to-date. Development of a comprehensive test plan for this process is recommended for use in the field trial portion of this program.

  9. A model to assess the comfort of automotive seat cushions.

    Science.gov (United States)

    Jiaxing, Zhan; Fard, Mohammad; Jazar, Reza

    2014-01-01

    A large number of independent and interacting factors affect seating comfort such as seat shape, stability, lumbar support and seat height. Although many subjective comfort studies have been conducted, few of them considered seating comfort from its subassembly level. This paper analyzed the automotive seat cushion designed with geared four-bar linkage for the seat height adjustment. The operation torque and lift distance of this mechanism was investigated as 2 major comfort factors. Ten cushions with this kind of design in the market were compared and assessed.

  10. New microalloyed steel applications for the automotive sector

    Energy Technology Data Exchange (ETDEWEB)

    Matlock, D.K.; Krauss, G.; Speer, J.G. [Advanced Steel Processing and Products Research Center, Colorado School of Mines, Golden, CO (United States)

    2005-07-01

    Developments related to the use of microalloy additions, primarily of Ti, Nb, and V, and controlled processing are reviewed to illustrate how steels with tailored microstructures and properties are produced from either bar or sheet steels for new automotive components. Microalloying additions are shown to control the necessary strengthening mechanisms to produce high strength materials with the desired toughness or formability for a specific application. Selected examples of direct cooled forging steels, microalloyed carburizing steels, and advanced high strength sheet (AHSS) steels are discussed. (orig.)

  11. Cross-talk between nucleotide excision and homologous recombination DNA repair pathways in the mechanism of action of antitumor trabectedin.

    Science.gov (United States)

    Herrero, Ana B; Martín-Castellanos, Cristina; Marco, Esther; Gago, Federico; Moreno, Sergio

    2006-08-15

    Trabectedin (Yondelis) is a potent antitumor drug that has the unique characteristic of killing cells by poisoning the DNA nucleotide excision repair (NER) machinery. The basis for the NER-dependent toxicity has not yet been elucidated but it has been proposed as the major determinant for the drug's cytotoxicity. To study the in vivo mode of action of trabectedin and to explore the role of NER in its cytotoxicity, we used the fission yeast Schizosaccharomyces pombe as a model system. Treatment of S. pombe wild-type cells with trabectedin led to cell cycle delay and activation of the DNA damage checkpoint, indicating that the drug causes DNA damage in vivo. DNA damage induced by the drug is mostly caused by the NER protein, Rad13 (the fission yeast orthologue to human XPG), and is mainly repaired by homologous recombination. By constructing different rad13 mutants, we show that the DNA damage induced by trabectedin depends on a 46-amino acid region of Rad13 that is homologous to a DNA-binding region of human nuclease FEN-1. More specifically, an arginine residue in Rad13 (Arg961), conserved in FEN1 (Arg314), was found to be crucial for the drug's cytotoxicity. These results lead us to propose a model for the action of trabectedin in eukaryotic cells in which the formation of a Rad13/DNA-trabectedin ternary complex, stabilized by Arg961, results in cell death.

  12. PlGF repairs myocardial ischemia through mechanisms of angiogenesis, cardioprotection and recruitment of myo-angiogenic competent marrow progenitors.

    Directory of Open Access Journals (Sweden)

    Hiroto Iwasaki

    Full Text Available RATIONALE: Despite preclinical success in regenerating and revascularizing the infarcted heart using angiogenic growth factors or bone marrow (BM cells, recent clinical trials have revealed less benefit from these therapies than expected. OBJECTIVE: We explored the therapeutic potential of myocardial gene therapy of placental growth factor (PlGF, a VEGF-related angiogenic growth factor, with progenitor-mobilizing activity. METHODS AND RESULTS: Myocardial PlGF gene therapy improves cardiac performance after myocardial infarction, by inducing cardiac repair and reparative myoangiogenesis, via upregulation of paracrine anti-apoptotic and angiogenic factors. In addition, PlGF therapy stimulated Sca-1(+/Lin(- (SL BM progenitor proliferation, enhanced their mobilization into peripheral blood, and promoted their recruitment into the peri-infarct borders. Moreover, PlGF enhanced endothelial progenitor colony formation of BM-derived SL cells, and induced a phenotypic switch of BM-SL cells, recruited in the infarct, to the endothelial, smooth muscle and cardiomyocyte lineage. CONCLUSIONS: Such pleiotropic effects of PlGF on cardiac repair and regeneration offer novel opportunities in the treatment of ischemic heart disease.

  13. Green competitiveness research on Chinese automotive enterprises

    Directory of Open Access Journals (Sweden)

    Yuanhui Li

    2014-05-01

    Full Text Available Purpose: More and more executives of automobileindustry in China start to recognize the concept of green competitiveness recently. However, relatively less research attention has been devoted to the consideration of measurement. This paper aims to find empirical approach to quantify green competitiveness for automotive enterprises. The connotation of green competitiveness is explored and one suite of evaluation index system has been proposed with four dimensions including environmental, resource, capability and knowledge.Design/methodology/approach: By introducing the factor analysis method, green competitiveness has been measured through an empirical analysis of 24 automotive enterprises within China.Findings: The results indicate that those elements, such as enterprise resource possession and utilization; environment, responsibility and knowledge; profitability; management efficiency, have significant effect on the green competitiveness for automotive enterprises. The further analysis also unveils the advantages and disadvantages of green competitiveness for each company and the direction for improvement.Research limitations/implications: Guide regulators and managers of automobile industry to take some measures to enhance their green competitive advantage.Practical implications: Provide practical methods to measure green competitiveness for automotive enterprises.Originality/value: This paper proposes an evaluation index system of green competitiveness for automotive enterprises. The suggestions of our research will be beneficial to enterprise executives and industry regulators.

  14. Platinum availability for future automotive technologies.

    Science.gov (United States)

    Alonso, Elisa; Field, Frank R; Kirchain, Randolph E

    2012-12-04

    Platinum is an excellent catalyst, can be used at high temperatures, and is stable in many aggressive chemical environments. Consequently, platinum is used in many current industrial applications, notably automotive catalytic converters, and prospective vehicle fuel cells are expected to rely upon it. Between 2005 and 2010, the automotive industry used approximately 40% of mined platinum. Future automotive industry growth and automotive sales shifts toward new technologies could significantly alter platinum demand. The potential risks for decreased platinum availability are evaluated, using an analysis of platinum market characteristics that describes platinum's geophysical constraints, institutional efficiency, and dynamic responsiveness. Results show that platinum demand for an automotive fleet that meets 450 ppm greenhouse gas stabilization goals would require within 10% of historical growth rates of platinum supply before 2025. However, such a fleet, due largely to sales growth in fuel cell vehicles, will more strongly constrain platinum supply in the 2050 time period. While current platinum reserves are sufficient to satisfy this increased demand, decreasing platinum ore grade and continued concentration of platinum supply in a single geographic area are availability risk factors to platinum end-users.

  15. Exhaust gas energy recovery system of pneumatic driving automotive engine

    Institute of Scientific and Technical Information of China (English)

    Han Yongqiang; Sun Wenxu; Li Qinghua; Zhong Ming; Hao Wei; Du Wenchang

    2011-01-01

    Almost the same quantity to net output work of energy has been carried out and wasted by exhaust gas in typical automotive engine. Recovering the energy from exhaust gas and converting to mechanical energy will dramatically increase the heat efficiency and decrease the fuel consumption. With the increasing demand of fuel conservation, exhaust gas energy recovery technologies have been a hot topic. At present, many researches have been focused on heating or cooling the cab, mechanical energy using and thermo-electronic converting. Unfortunately, the complicated transmission of mechanical energy using and the depressed efficiency of thermo-electronic converting restrict their widely applying. In this paper, a kind of exhaust gas energy recovery system of pneumatic driving automotive engine, in which highly compressed air acts as energy storing and converting carrier, has been established. Pneumatic driving motor can produce moderate speed and high torque output, which is compatible for engine using. The feasibility has been certificated by GT-Power simulation and laboratory testes. The technologies about increasing recovery efficiency have been discussed in detail. The results demonstrated that the in parallel exhaust gas energy recovery system, which is similar to the compound turbo-charger structure can recovery 8 to 10 percent of rated power output. At last, a comprehensive system,which includes Rankine cycle based power wheel cycle unit etc. , has been introduced.

  16. Materials Challenges for Automotive PEM Fuel Cells

    Science.gov (United States)

    Gasteiger, Hubert

    2004-03-01

    Over the past few years, significant R efforts aimed at meeting the challenging cost and performance targets required for the use of Polymer Electrolyte Membrane (PEM) fuel cells in automotive applications. Besides engineering advances in bipolar plate materials and design, the optimization of membrane-electrode assemblies (MEAs) was an important enabler in reducing the cost and performance gaps towards commercial viability for the automotive market. On the one hand, platinum loadings were reduced from several mgPt/cm2MEA [1] to values of 0.5-0.6 mgPt/cm2MEA in current applications and loadings as low as 0.25 mgPt/cm2MEA have been demonstrated on the research level [2]. On the other hand, implementation of thin membranes (20-30 micrometer) [3, 4] as well as improvements in diffusion medium materials, essentially doubled the achievable power density of MEAs to ca. 0.9 W/cm2MEA (at 0.65 V) [5], thereby not only reducing the size of a PEMFC fuel cell system, but also reducing its overall materials cost (controlled to a large extent by membrane and Pt-catalyst cost). While this demonstrated a clear path towards automotive applications, a renewed focus of R efforts is now required to develop materials and fundamental materials understanding to assure long-term durability of PEM fuel cells. This presentation therefore will discuss the state-of-the-art knowledge of catalyst, catalyst-support, and membrane degradation mechanisms. In the area of Pt-catalysts, experience with phosphoric acid fuel cells (PAFCs) has shown that platinum sintering leads to long-term performance losses [6]. While this is less critical at the lower PEMFC operating temperatures (200C), very little is known about the dependence of Pt-sintering on temperature, cell voltage, and catalyst type (i.e., Pt versus Pt-alloys) and will be discussed here. Similarly, carbon-support corrosion can contribute significantly to voltage degradation in PAFCs [7], and even in the PEMFC environment more corrosion

  17. Branding through trade shows in the automotive industry

    OpenAIRE

    Narui, Jahan

    2013-01-01

    The automotive industry is a major global industry with a great history of exhibitions. As trade shows are getting more attention within studies, the same is not the case for automotive trade shows. Noteworthy, automotive trade shows emphasize non-selling roles such as image-building. This paper seeks to investigate image-building purposes of exhibiting automotive companies using integrated marketing communications (IMC). Data has been gathered from four participating companies in the Geneva ...

  18. Branding through trade shows in the automotive industry

    OpenAIRE

    Narui, Jahan

    2013-01-01

    The automotive industry is a major global industry with a great history of exhibitions. As trade shows are getting more attention within studies, the same is not the case for automotive trade shows. Noteworthy, automotive trade shows emphasize non-selling roles such as image-building. This paper seeks to investigate image-building purposes of exhibiting automotive companies using integrated marketing communications (IMC). Data has been gathered from four participating companies in the Geneva ...

  19. Design of an FMCW radar baseband signal processing system for automotive application.

    Science.gov (United States)

    Lin, Jau-Jr; Li, Yuan-Ping; Hsu, Wei-Chiang; Lee, Ta-Sung

    2016-01-01

    For a typical FMCW automotive radar system, a new design of baseband signal processing architecture and algorithms is proposed to overcome the ghost targets and overlapping problems in the multi-target detection scenario. To satisfy the short measurement time constraint without increasing the RF front-end loading, a three-segment waveform with different slopes is utilized. By introducing a new pairing mechanism and a spatial filter design algorithm, the proposed detection architecture not only provides high accuracy and reliability, but also requires low pairing time and computational loading. This proposed baseband signal processing architecture and algorithms balance the performance and complexity, and are suitable to be implemented in a real automotive radar system. Field measurement results demonstrate that the proposed automotive radar signal processing system can perform well in a realistic application scenario.

  20. Rotordynamics of automotive turbochargers. Linear and nonlinear rotordynamics - Bearing design - Rotor balancing

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen-Schaefer, Hung [Bosch Mahle Turbo Systems GmbH und Co. KG, Stuttgart (Germany)

    2012-11-01

    Describes the rotordynamics of automotive turbochargers. Requires only a minimum of mathematical background. Written by an R and D expert from industry. This book deals with rotordynamics of automotive turbochargers while encompassing the analysis of the dynamics of rotating machines at very high rotor speeds of 300,000 rpm and above. This interdisciplinary field involves 1. thermodynamics and turbo-matching knowledge to compute working conditions of turbochargers, 2. fluid and bearing dynamics to calculate various operating thrust loads and to design the rotating floating ring bearings (two-oil-film bearings), and 3. tribology to improve the rotor stability and to reduce the bearing friction. Mathematical background in modeling and simulation methods is necessary; however, the prerequisites have been kept to a minimum. The book addresses both practitioners working in the field of rotordynamics of automotive turbochargers and graduate students in mechanical engineering.

  1. Nucleotide excision repair in yeast

    NARCIS (Netherlands)

    Eijk, Patrick van

    2012-01-01

    Nucleotide Excision Repair (NER) is a conserved DNA repair pathway capable of removing a broad spectrum of DNA damage. In human cells a defect in NER leads to the disorder Xeroderma pigmentosum (XP). The yeast Saccharomyces cerevisiae is an excellent model organism to study the mechanism of NER. The

  2. Advanced casting technologies for lightweight automotive applications

    Directory of Open Access Journals (Sweden)

    Alan A. Luo

    2010-11-01

    Full Text Available This paper provides an overview of alloy and process developments in aluminum and magnesium castings for lightweight automotive applications. Wear-resistant aluminum alloys, creep-resistant and high strength/ductility magnesium alloys have been developed for automotive applications. On the process front, vacuum-assisted die casting and high vacuum die casting technologies have been developed for high-integrity body and chassis applications. Thin-wall and hollow casting components are being produced by low-pressure die casting processes for structural applications. Overcasting technology is gaining traction and has enabled mixed material designs for automotive sub-systems such as engine cradles and instrument panel beams. Simulation tools developed to predict the interfacial interactions of the dissimilar components and the structural integrity of the overcast systems are being validated in the casting trials.

  3. My father’s automotive dream

    Institute of Scientific and Technical Information of China (English)

    Rain Chen

    2005-01-01

    <正>Memories of Changchun Changchun literally means ’Long Spring’. The city is located in northeast China’s Jilin province, which literally means ’Lucky Forest’. Since my father is an old worker of Changchun’s Yi Qi(the abbreviation of Changchun First Automotive Factory) plant - China’s earliest automotive plant, I have spent 60 years in the city, graduating from the well-established Jilin University and currently working for a periodical association. A friend from Beijing encouraged me to write my family’s history, and since my family’s story is really a story about the good name of Changchun, an automotive city and a college town, I couldn’t refuse.

  4. Optimization and optimal control in automotive systems

    CERN Document Server

    Kolmanovsky, Ilya; Steinbuch, Maarten; Re, Luigi

    2014-01-01

    This book demonstrates the use of the optimization techniques that are becoming essential to meet the increasing stringency and variety of requirements for automotive systems. It shows the reader how to move away from earlier  approaches, based on some degree of heuristics, to the use of  more and more common systematic methods. Even systematic methods can be developed and applied in a large number of forms so the text collects contributions from across the theory, methods and real-world automotive applications of optimization. Greater fuel economy, significant reductions in permissible emissions, new drivability requirements and the generally increasing complexity of automotive systems are among the criteria that the contributing authors set themselves to meet. In many cases multiple and often conflicting requirements give rise to multi-objective constrained optimization problems which are also considered. Some of these problems fall into the domain of the traditional multi-disciplinary optimization applie...

  5. Automotive Radar Sensors in Silicon Technologies

    CERN Document Server

    Jain, Vipul

    2013-01-01

    This book presents architectures and design techniques for mm-wave automotive radar transceivers. Several fully-integrated transceivers and receivers operating at 22-29 GHz and 77-81 GHz are demonstrated in both CMOS and SiGe BiCMOS technologies. Excellent performance is achieved indicating the suitability of silicon technologies for automotive radar sensors.  This book bridges an existing gap between information available on dependable system/architecture design and circuit design.  It provides the background of the field and detailed description of recent research and development of silicon-based radar sensors.  System-level requirements and circuit topologies for radar transceivers are described in detail. Holistic approaches towards designing radar sensors are validated with several examples of highly-integrated radar ICs in silicon technologies. Circuit techniques to design millimeter-wave circuits in silicon technologies are discussed in depth.  Describes concepts and fundamentals of automotive rada...

  6. Materials selection for automotive engines. (Latest citations from Metadex). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    The bibliography contains citations concerning material selection and substitution for automobile engines. Mechanical properties, including dimensional stability, are reviewed. Machined parts, castings, forgings, and extrusions are examined. Citations concerning automotive bodies, frames, and structures are presented in a separate bibliography.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  7. Materials selection for automotive engines. (Latest citations from Metadex). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    The bibliography contains citations concerning material selection and substitution for automobile engines. Mechanical properties, including dimensional stability, are reviewed. Machined parts, castings, forgings, and extrusions are examined. Citations concerning automotive bodies, frames, and structures are presented in a separate bibliography.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  8. Hierarchical modeling of automotive sensor front-ends for structural diagnosis of aging faults

    NARCIS (Netherlands)

    Kerkhoff, Hans G.; Wan, J.; Zhao, Yong

    2012-01-01

    The semiconductor industry for automotive applications is growing rapidly. This is because advanced electronics is now being developed to monitor and control many vital functions previously handled purely mechanical. In addition hybrid and pure electrical cars are emerging. Parts of these electronic

  9. Can Distance Learning Be Used to Teach Automotive Management Skills?

    Science.gov (United States)

    Noto, Teresa L.

    2011-01-01

    Today's automotive college students will shape the future of the automobile industry. The success of college-level automotive programs has long been dependent on the students' ability to participate in hands-on classroom based interactions. In this article, distance learning and how it can be used to teach automotive management skills, as well as…

  10. 25 CFR 117.10 - Purchase of automotive equipment.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Purchase of automotive equipment. 117.10 Section 117.10... COMPETENCY § 117.10 Purchase of automotive equipment. The superintendent may disburse from the surplus funds of an adult Indian not to exceed $2,000 for the purchase of automotive equipment when the...

  11. Best Practices in School-to-Careers: The Automotive Industry.

    Science.gov (United States)

    National Employer Leadership Council, Washington, DC.

    This document highlights the school-to-careers (STC) partnerships connecting workplace experiences to classroom learning to prepare students for successful employment in the automotive industry. First, the current state of the automotive industry is reviewed and the role of STC in addressing automotive service needs is explained. Next, the…

  12. Hypospadias repair

    Science.gov (United States)

    ... the problem. If the repair is not done, problems may occur later on such as: Difficulty controlling and directing urine stream A curve in the penis during erection Decreased fertility Embarrassment about appearance of penis Surgery ...

  13. Excited-state proton coupled electron transfer between photolyase and the damaged DNA through water wire: a photo-repair mechanism.

    Science.gov (United States)

    Wang, Hongjuan; Chen, Xuebo; Fang, Weihai

    2014-12-14

    The photolyase enzyme absorbs blue light to repair damaged DNA through a cyclic electron transfer reaction. A description of the underlying mechanism has proven to be a challenging issue for both experimental and theoretical studies. In the present work, combined CASPT2//CASSCF/AMBER (QM/MM) calculations have been performed for damaged DNA in photolyase. A proton-coupled electron transfer (PCET) mechanism has been determined for restoring cyclobutane pyrimidine dimer (CPD) to two normal thymine bases by irradiation of photolyase. A well-defined water wire between FADH(-) and CPD was determined as a bridge to assist the PCET process within FADH(-) and thereby trigger the forward electron transfer to CPD. The subsequent CPD splitting and the alternation of the H-bond pattern proceed in a concerted way, which makes the productive backward electron transfer occur on an ultrafast timescale. A local minimum of SCT((1)ππ*)-LMin was identified on the pathway of the futile backward electron transfer (BET), which is stabilized by the strong H-bond interaction between the water wire and CPD. As a result, the futile BET process is endothermic by ∼18.0 kcal mol(-1), which is responsible for a 2.4 ns timescale inferred experimentally for the futile BET process. Besides the unbiased interpretation for the majority of the experimental findings, the present study provides a new excited-state PCET mechanism, which leads to a significant step toward a deeper understanding of the photo-repair process of damaged-DNA by the photolyase enzyme.

  14. New market strategies in the automotive industry

    Directory of Open Access Journals (Sweden)

    Kokić Miljko

    2006-01-01

    Full Text Available The world automotive industry has about 30% of excessive capacity. Regardless of that, the new plants are being constantly built. The countries of the East Europe, China and India are selected as suitable areas by almost all world leading car manufactures to build their additional plants in order to make profits. An open world market is subject to an uncompromising striving for each customer. Our manufacturers have to meet the same requirements if want to offer their products in the world market. Finding out of foreign strategic partners is the fastest way to recover a domestic automotive industry and to increase an employment rate.

  15. Nanotechnology impact on the automotive industry.

    Science.gov (United States)

    Wong, Kaufui V; Paddon, Patrick A

    2014-01-01

    Nanotechnology has been implemented widely in the automotive industry. This technology is particularly useful in coatings, fabrics, structural materials, fluids, lubricants, tires, and preliminary applications in smart glass/windows and video display systems. A special sub-class of improved materials, alternative energy, has also seen a boost from advances in nanotechnology, and continues to be an active research area. A correlation exists in the automotive industry between the areas with increased nanotechnology incorporation and those with increased profit margins via improvements and customer demands.

  16. Investigation of metallurgical coatings for automotive applications

    Science.gov (United States)

    Su, Jun Feng

    Metallurgical coatings have been widely used in the automotive industry from component machining, engine daily running to body decoration due to their high hardness, wear resistance, corrosion resistance and low friction coefficient. With high demands in energy saving, weight reduction and limiting environmental impact, the use of new materials such as light Aluminum/magnesium alloys with high strength-weight ratio for engine block and advanced high-strength steel (AHSS) with better performance in crash energy management for die stamping, are increasing. However, challenges are emerging when these new materials are applied such as the wear of the relative soft light alloys and machining tools for hard AHSS. The protective metallurgical coatings are the best option to profit from these new materials' advantages without altering largely in mass production equipments, machinery, tools and human labor. In this dissertation, a plasma electrolytic oxidation (PEO) coating processing on aluminum alloys was introduced in engine cylinder bores to resist wear and corrosion. The tribological behavior of the PEO coatings under boundary and starve lubrication conditions was studied experimentally and numerically for the first time. Experimental results of the PEO coating demonstrated prominent wear resistance and low friction, taking into account the extreme working conditions. The numerical elastohydrodynamic lubrication (EHL) and asperity contact based tribological study also showed a promising approach on designing low friction and high wear resistant PEO coatings. Other than the fabrication of the new coatings, a novel coating evaluation methodology, namely, inclined impact sliding tester was presented in the second part of this dissertation. This methodology has been developed and applied in testing and analyzing physical vapor deposition (PVD)/ chemical vapor deposition (CVD)/PEO coatings. Failure mechanisms of these common metallurgical hard coatings were systematically

  17. Impaired mechanical response of an EDMD mutation leads to motility phenotypes that are repaired by loss of prenylation.

    Science.gov (United States)

    Zuela, Noam; Zwerger, Monika; Levin, Tal; Medalia, Ohad; Gruenbaum, Yosef

    2016-05-01

    There are roughly 14 distinct heritable autosomal dominant diseases associated with mutations in lamins A/C, including Emery-Dreifuss muscular dystrophy (EDMD). The mechanical model proposes that the lamin mutations change the mechanical properties of muscle nuclei, leading to cell death and tissue deterioration. Here, we developed an experimental protocol that analyzes the effect of disease-linked lamin mutations on the response of nuclei to mechanical strain in living Caenorhabditis elegans We found that the EDMD mutation L535P disrupts the nuclear mechanical response specifically in muscle nuclei. Inhibiting lamin prenylation rescued the mechanical response of the EDMD nuclei, reversed the muscle phenotypes and led to normal motility. The LINC complex and emerin were also required to regulate the mechanical response of C. elegans nuclei. This study provides evidence to support the mechanical model and offers a potential future therapeutic approach towards curing EDMD.

  18. Precious metal-support interaction in automotive exhaust catalysts

    Institute of Scientific and Technical Information of China (English)

    郑婷婷; 何俊俊; 赵云昆; 夏文正; 何洁丽

    2014-01-01

    Precious metal-support interaction plays an important role in thermal stability and catalytic performance of the automotive exhaust catalysts. The support is not only a carrier for active compounds in catalysts but also can improve the dispersion of precious metals and suppress the sintering of precious metals at high temperature;meanwhile, noble metals can also enhance the redox per-formance and oxygen storage capacity of support. The mechanism of metal-support interactions mainly includes electronic interaction, formation of alloy and inward diffusion of metal into the support or covered by support. The form and degree of precious metal-sup-port interaction depend on many factors, including the content of precious metal, the species of support and metal, and preparation methods. The research results about strong metal-support interaction (SMSI) gave a theory support for developing a kind of new cata-lyst with excellent performance. This paper reviewed the interaction phenomenon and mechanism of precious metals (Pt, Pd, Rh) and support such as Al2O3, CeO2, and CeO2-based oxides in automotive exhaust catalysts. The factors that affect SMSI and the catalysts developed by SMSI were also discussed.

  19. Composites on the way to structural automotive applications

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, H.; Kopp, J.; Stieg, J. [Volkswagen AG, Wolfsburg (Germany)

    2003-07-01

    Against the background of a steady increase of the standards on comfort, passive safety and driving performance of vehicles as well as the commitment to reduce fuel consumption and carbon dioxide emissions, the demand for lightweight construction attains paramount importance. The use of aluminum, magnesium or new steel alloys in the body structure can lead to significant weight reduction compared with conventional steel concepts. Furthermore, maximum weight reduction will require an intensive use of advanced composites in primary structures. The paper deals with the potentials and the challenges coming along with the introduction of advanced composites into automotive series production. Presently, liquid composite molding and compression molding of high-performance SMC are the most promising technologies to achieve demanding composite parts with high fiber volume fraction, good surface quality and controlled mechanical properties. The performance of specific automotive application processed in these techniques is presented and discussed. On principle, the cost/benefit aspect is of decisive importance for larger volume applications. Considerable efforts are necessary to reduce material and semi-finished product costs and to provide manufacturing technologies which are capable of allowing large-volume automotive production of composite components. Especially concepts are desirable which do not only provide a basic material substitution but rather an intelligent design based on component and functional integration as one of the most effective strategies to exploit the advantages of advanced composites. These aspects will be regarded and a brief summary on some other remaining challenges like recycling, crash simulation or joining and assembly technologies for mixed material concepts will be given. (orig.)

  20. Mechanical behavior of pre tensioned metallic sleeves for pipeline repair; Comportamento mecanico de luvas metalicas pre tensionadas para reparo de dutos terrestres

    Energy Technology Data Exchange (ETDEWEB)

    Meniconi, Luiz C.M.; Paes, Marcelo T. Piza [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas; Frainer, Vitor [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Dept. de Metalurgia. Lab. de Metalurgia Fisica (LAMEF); Souza Filho, Byron G. de [PETROBRAS Transportes S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil); Patricio, Wagner [Foxoil do Brasil Ltda., Macae, RJ (Brazil)

    2005-07-01

    Two different methods for pre-tensioning of metallic sleeves for pipeline repair were appraised: mechanic, by means of hydraulic jacks, and thermal, trough the use of oxyacetylene torches. Hydraulic jacks promote an 'in situ' forming of the sleeves, once they impose loads rather than displacements. There is no need of a perfect match between the external diameter of the pipe and the internal diameter of the sleeve. The thermal method, on the other hand, needs a tight fit between the sleeve and the pipe to assure that thermal expansion will turn into elastic deformation. Test specimens were built with four different defect types: crack, dent, gouged dent and thickness loss due to corrosion. The use of pre-tensioned sleeves led to failure pressures 39% above the hydro test pressure, at least. All the specimen failures occurred outside the reinforced area. (author)

  1. Fix-It Careers: Jobs in Repair

    Science.gov (United States)

    Torpey, Elka Maria

    2010-01-01

    From auto mechanic to HVAC technicians, many occupations require repair skills. For jobseekers with the right skills, there are many advantages to a repair career. Repair work provides millions of jobs throughout the United States. Wages are often higher than average. And in many occupations, the employment outlook is bright. Plus, most repair…

  2. Research progress of aluminum alloy automotive sheet and application technology

    Institute of Scientific and Technical Information of China (English)

    Ma Mingtu; You Jianghai; Lu Hongzhou; Wang Zhiwen

    2012-01-01

    Pretrcatment technology is deeply discussed to explain its importance in guaranteeing properties and form- ability of aluminum alloy automotive sheet. Some typical applications of aluminum alloy automotive sheet to automotive industry are listed. Based on the author's knowledge and recognition and research progress presently, the important re- search contents about aluminum alloy automotive sheet are emphasized. Reducing cost and price of sheet and going deeply into application research are the main work for expending the application of aluminum alloy automotive sheet in the automobile.

  3. Collagen based film with well epithelial and stromal regeneration as corneal repair materials: Improving mechanical property by crosslinking with citric acid

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xuan; Liu, Yang; Li, Weichang; Long, Kai; Wang, Lin; Liu, Sa; Wang, Yingjun [School of Materials Science and Engineering, South China University of Technology, Guangzhou (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou (China); Ren, Li, E-mail: psliren@scut.edu.cn [School of Materials Science and Engineering, South China University of Technology, Guangzhou (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou (China)

    2015-10-01

    Corneal disease can lead to vision loss. It has become the second greatest cause of blindness in the world, and keratoplasty is considered as an effective treatment method. This paper presents the crosslinked collagen (Col)–citric acid (CA) films developed by making use of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The results showed that the Col–CA films had necessary optical performance, water content. The collagenase resistance of CA crosslinked films was superior to that of EDC crosslinked films. And CA5 film (Col:CA:EDC:NHS = 60:3:10:10) had the best mechanical properties. Cell experiments showed that CA5 film was non-cytotoxic and human corneal epithelial cells could proliferate well on the films. Lamellar keratoplasty showed that the CA5 film could be sutured in the rabbit eyes and was epithelialized completely in about 10 days, and the transparency was restored quickly in 30 ± 5 days. No inflammation and corneal neovascularization were observed at 6 months. Corneal stroma had been repaired; stromal cells and neo-stroma could be seen in the area of operation from the hematoxylin–eosin stained histologic sections and anterior segment optical coherence tomography images. These results indicated that Col–CA films were highly promising biomaterials that could be used in corneal tissue engineering and a variety of other tissue engineering applications. - Highlights: • Adding different amounts of citric acid could change the properties of films. • The crosslinked films had better mechanical property than non-modified films. • Crosslinked collagen–citric acid films could tolerate suture during operation. • The films showed good ability of epithelial and stromal repair.

  4. Mechanism of protection of adenosine from sulphate radical anion and repair of adenosine radicals by caffeic acid in aqueous solution

    Indian Academy of Sciences (India)

    M Sudha Swaraga; L Charitha; M Adinarayana

    2005-07-01

    The photooxidation of adenosine in presence of peroxydisulphate (PDS) has been studied by spectrophotometrically measuring the absorbance of adenosine at 260 nm. The rates of oxidation of adenosine by sulphate radical anion have been determined in the presence of different concentrations of caffeic acid. Increase in [caffeic acid] is found to decrease the rate of oxidation of adenosine suggesting that caffeic acid acts as an efficient scavenger of $SO_{4}^{\\bullet-}$ and protects adenosine from it. Sulphate radical anion competes for adenosine as well as for caffeic acid. The quantum yields of photooxidation of adenosine have been calculated from the rates of oxidation of adenosine and the light intensity absorbed by PDS at 254 nm, the wavelength at which PDS is activated to sulphate radical anion. From the results of experimentally determined quantum yields (exptl) and the quantum yields calculated (cal) assuming caffeic acid acting only as a scavenger of $SO_{4}^{\\bullet-}$ show that exptl values are lower than cal values. The ' values, which are experimentally found quantum yield values at each caffeic acid concentration and corrected for $SO_{4}^{\\bullet-}$ scavenging by caffeic acid, are also found to be greater than exptl values. These observations suggest that the transient adenosine radicals are repaired by caffeic acid in addition to scavenging of sulphate radical anions.

  5. Market Opportunities for Automotive Components Used in Non-automotive Applications Manufacturing : Estonian Industrial Market

    OpenAIRE

    Kalajärv, Jaana

    2012-01-01

    This thesis examines the opportunities available for automotive components in the Esto-nian non-automotive industrial market. The literature review part is mainly covers the theory of marketing research, because of the approach chosen for this paper. Only small part of marketing research process is re-searched closer in literature review section, because of the scope of the research. Three most relevant steps for the thesis are chosen from research process for further more in-vestigation,...

  6. DNA-damage response associated with occupational exposure, age and chronic inflammation in workers in the automotive industry.

    Science.gov (United States)

    Savina, Natalya V; Smal, Marharyta P; Kuzhir, Tatyana D; Ershova-Pavlova, Alla A; Goncharova, Roza I

    2012-10-09

    The evaluation of genome integrity in populations occupationally exposed to combine industrial factors is of medical importance. In the present study, the DNA-damage response was estimated by means of the alkaline comet assay in a sizeable cohort of volunteers recruited among workers in the automotive industry. For this purpose, freshly collected lymphocytes were treated with hydrogen peroxide (100μM, 1min, 4°C) in vitro, and the levels of basal and H(2)O(2)-induced DNA damage, and the kinetics and efficiency of DNA repair were measured during a 180-min interval after exposure. The parameters studied in the total cohort of workers were in a range of values prescribed for healthy adult residents of Belarus. Based on the 95th percentiles, individuals possessing enhanced cellular sensitivity to DNA damage were present in different groups, but the frequency was significantly higher among elderly persons and among individuals with chronic inflammatory diseases. The results indicate that the inter-individual variations in DNA-damage response should be taken into account to estimate adequately the environmental genotoxic effects and to identify individuals with an enhanced DNA-damage response due to the influence of some external factors or intrinsic properties of the organism. Underling mechanisms need to be further explored. © 2012 Elsevier B.V. All rights reserved.

  7. On credibility improvements for automotive navigation systems

    NARCIS (Netherlands)

    Schaub, Florian; Hipp, Markus; Kargl, Frank; Weber, Michael

    2012-01-01

    Automotive navigation systems are becoming ubiquitous as driver assistance systems. Vendors continuously aim to enhance route guidance by adding new features to their systems. However, we found in an analysis of current navigation systems that many share interaction weaknesses, which can damage the

  8. International Conference on Vehicle and Automotive Engineering

    CERN Document Server

    Bolló, Betti

    2017-01-01

    This book presents the proceedings of the first vehicle engineering and vehicle industry conference. It captures the outcome of theoretical and practical studies as well as the future development trends in a wide field of automotive research. The themes of the conference include design, manufacturing, economic and educational topics.

  9. Training Issues for the European Automotive Industry

    NARCIS (Netherlands)

    Dankbaar, B.

    1996-01-01

    Provides an overview of the results of an investigation carried out for the European Commission. Aims to identify themes and issues in the field of continuing training in the European automotive industry. A large number of interviews were carried out in all the major car manufacturing countries of

  10. Training issues for the European automotive industry

    NARCIS (Netherlands)

    Dankbaar, B.

    1999-01-01

    Provides an overview of the results of an investigation carried out for the European Commission. Aims to identify themes and issues in the field of continuing training in the European automotive industry. A large number of interviews were carried out in all the major car manufacturing countries of

  11. Green innovation adoption in automotive supply chain

    DEFF Research Database (Denmark)

    Zailani, Suhaiza; Govindan, Kannan; Iranmanesh, Mohammad

    2015-01-01

    Green innovation has currently been receiving a great deal of international attention because of the growing concern of consumers, governments, and the community as a whole with regard to the degradation of natural resources and environmental pollution. The automotive sector is one of the leading...

  12. Metrics for Automotive Merchandising, Petroleum Marketing.

    Science.gov (United States)

    Cooper, Gloria S., Ed.; Magisos, Joel H., Ed.

    Designed to meet the job-related metric measurement needs of students in automotive merchandising and petroleum marketing classes, this instructional package is one of five for the marketing and distribution cluster, part of a set of 55 packages for metric instruction in different occupations. The package is intended for students who already know…

  13. Solidification studies of automotive heat exchanger materials

    Science.gov (United States)

    Carlberg, T.; Jaradeh, M.; Kamgou Kamaga, H.

    2006-11-01

    Modifications of the aluminum alloy AA 3003 have been studied to improve and tailorits properties for applications in automotive heat exchangers. Laboratory techniques have been applied to simulate industrial direct-chill casting, and some basic solidification studies have been conducted. The results are coupled to structures observed in industrial-size ingots and discussed in terms of structure-property relations.

  14. Techno-economic requirements for automotive composites

    Science.gov (United States)

    Arnold, Scot

    1993-01-01

    New technology generally serves two main goals of the automotive industry: one is to enable vehicles to comply with various governmental regulations and the other is to provide a competitive edge in the market. The latter goal can either be served through improved manufacturing and design capabilities, such as computer aided design and computer aided manufacturing, or through improved product performance, such as anti-lock braking (ABS). Although safety features are sometimes customer driven, such as the increasing use of airbags and ABS, most are determined by regulations as outlined by the Federal Motor Vehicle Safety Standards (FMVSS). Other standards, set by the Environmental Protection Agency, determine acceptable levels of emissions and fuel consumption. State governments, such as in California, are also setting precedent standards, such as requiring manufacturers to offer zero-emission vehicles as a certain fraction of their sales in the state. The drive to apply new materials in the automobile stems from the need to reduce weight and improve fuel efficiency. Topics discussed include: new lightweight materials; types of automotive materials; automotive composite applications; the role for composite materials in automotive applications; advantages and disadvantages of composite materials; material substitution economics; economic perspective; production economics; and composite materials production economics.

  15. A listening test system for automotive audio

    DEFF Research Database (Denmark)

    Christensen, Flemming; Geoff, Martin; Minnaar, Pauli;

    2005-01-01

    This paper describes a system for simulating automotive audio through headphones for the purposes of conducting listening experiments in the laboratory. The system is based on binaural technology and consists of a component for reproducing the sound of the audio system itself and a component...

  16. Exposure to electrocution by automotive ignition system in the work environment of car service employees

    Directory of Open Access Journals (Sweden)

    Bernard Fryśkowski

    2014-06-01

    Full Text Available Automotive ignition system diagnostic procedures involve a specific kind of action due to the presence of high voltage pulses rated of roughly several dozen kilovolts. Therefore, the repairers employed at car service coming into direct contact with electrical equipment of ignition systems are exposed to risk of electric shock. Typically, the electric discharge energy of automotive ignition systems is not high enough to cause fibrillation due to the electric effect on the heart. Nevertheless, there are drivers and car service employees who use electronic cardiac pacemakers susceptible to high voltage pulses. The influence of high-voltage ignition systems on the human body, especially in case of electric injury, has not been comprehensively elucidated. Therefore, relatively few scientific papers address this problem. The aim of this paper is to consider the electrical injury danger from automotive ignition systems, especially in people suffering from cardiac diseases. Some examples of the methods to reduce electric shock probability during diagnostic procedures of spark-ignition combustion engines are presented and discussed. Med Pr 2014;65(3:419–427

  17. Femoral hernia repair

    Science.gov (United States)

    Femorocele repair; Herniorrhaphy; Hernioplasty - femoral ... During surgery to repair the hernia, the bulging tissue is pushed back in. The weakened area is sewn closed or strengthened. This repair ...

  18. Undescended testicle repair

    Science.gov (United States)

    Orchidopexy; Inguinal orchidopexy; Orchiopexy; Repair of undescended testicle; Cryptorchidism repair ... first year of life without treatment. Undescended testicle repair surgery is recommended for patients whose testicles do ...

  19. Diverse Responses to UV-B Radiation and Repair Mechanisms of Bacteria Isolated from High-Altitude Aquatic Environments▿

    Science.gov (United States)

    Fernández Zenoff, V.; Siñeriz, F.; Farías, M. E.

    2006-01-01

    Acinetobacter johnsonii A2 isolated from the natural community of Laguna Azul (Andean Mountains at 4,560 m above sea level), Serratia marcescens MF42, Pseudomonas sp. strain MF8 isolated from the planktonic community, and Cytophaga sp. strain MF7 isolated from the benthic community from Laguna Pozuelos (Andean Puna at 3,600 m above sea level) were subjected to UV-B (3,931 J m−2) irradiation. In addition, a marine Pseudomonas putida strain, 2IDINH, and a second Acinetobacter johnsonii strain, ATCC 17909, were used as external controls. Resistance to UV-B and kinetic rates of light-dependent (UV-A [315 to 400 nm] and cool white light [400 to 700 nm]) and -independent reactivation following exposure were determined by measuring the survival (expressed as CFU) and accumulation of cyclobutane pyrimidine dimers (CPD). Significant differences in survival after UV-B irradiation were observed: Acinetobacter johnsonii A2, 48%; Acinetobacter johnsonii ATCC 17909, 20%; Pseudomonas sp. strain MF8, 40%; marine Pseudomonas putida strain 2IDINH, 12%; Cytophaga sp. strain MF7, 20%; and Serratia marcescens, 21%. Most bacteria exhibited little DNA damage (between 40 and 80 CPD/Mb), except for the benthic isolate Cytophaga sp. strain MF7 (400 CPD/Mb) and Acinetobacter johnsonii ATCC 17909 (160 CPD/Mb). The recovery strategies through dark and light repair were different in all strains. The most efficient in recovering were both Acinetobacter johnsonii A2 and Cytophaga sp. strain MF7; Serratia marcescens MF42 showed intermediate recovery, and in both Pseudomonas strains, recovery was essentially zero. The UV-B responses and recovery abilities of the different bacteria were consistent with the irradiation levels in their native environment. PMID:17056692

  20. Conceptual design study of an improved automotive gas turbine powertrain

    Science.gov (United States)

    Wagner, C. E. (Editor); Pampreen, R. C. (Editor)

    1979-01-01

    Automotive gas turbine concepts with significant technological advantages over the spark ignition (SI) engine were assessed. Possible design concepts were rated with respect to fuel economy and near-term application. A program plan which outlines the development of the improved gas turbine (IGT) concept that best met the goals and objectives of the study identifies the research and development work needed to meet the goal of entering a production engineering phase by 1983. The fuel economy goal is to show at least a 20% improvement over a conventional 1976 SI engine/vehicle system. On the basis of achieving the fuel economy goal, of overall suitability to mechanical design, and of automotive mass production cost, the powertrain selected was a single-shaft engine with a radial turbine and a continuously variable transmission (CVT). Design turbine inlet temperature was 1150 C. Reflecting near-term technology, the turbine rotor would be made of an advanced superalloy, and the transmission would be a hydromechanical CVT. With successful progress in long-lead R&D in ceramic technology and the belt-drive CVT, the turbine inlet temperature would be 1350 C to achieve near-maximum fuel economy.

  1. Analysis of Repair Mechanisms following an Induced Double-Strand Break Uncovers Recessive Deleterious Alleles in the Candida albicans Diploid Genome

    Science.gov (United States)

    Feri, Adeline; Loll-Krippleber, Raphaël; Commere, Pierre-Henri; Maufrais, Corinne; Sertour, Natacha; Schwartz, Katja; Sherlock, Gavin; Bougnoux, Marie-Elisabeth

    2016-01-01

    ABSTRACT The diploid genome of the yeast Candida albicans is highly plastic, exhibiting frequent loss-of-heterozygosity (LOH) events. To provide a deeper understanding of the mechanisms leading to LOH, we investigated the repair of a unique DNA double-strand break (DSB) in the laboratory C. albicans SC5314 strain using the I-SceI meganuclease. Upon I-SceI induction, we detected a strong increase in the frequency of LOH events at an I-SceI target locus positioned on chromosome 4 (Chr4), including events spreading from this locus to the proximal telomere. Characterization of the repair events by single nucleotide polymorphism (SNP) typing and whole-genome sequencing revealed a predominance of gene conversions, but we also observed mitotic crossover or break-induced replication events, as well as combinations of independent events. Importantly, progeny that had undergone homozygosis of part or all of Chr4 haplotype B (Chr4B) were inviable. Mining of genome sequencing data for 155 C. albicans isolates allowed the identification of a recessive lethal allele in the GPI16 gene on Chr4B unique to C. albicans strain SC5314 which is responsible for this inviability. Additional recessive lethal or deleterious alleles were identified in the genomes of strain SC5314 and two clinical isolates. Our results demonstrate that recessive lethal alleles in the genomes of C. albicans isolates prevent the occurrence of specific extended LOH events. While these and other recessive lethal and deleterious alleles are likely to accumulate in C. albicans due to clonal reproduction, their occurrence may in turn promote the maintenance of corresponding nondeleterious alleles and, consequently, heterozygosity in the C. albicans species. PMID:27729506

  2. Analysis of Repair Mechanisms following an Induced Double-Strand Break Uncovers Recessive Deleterious Alleles in the Candida albicans Diploid Genome.

    Science.gov (United States)

    Feri, Adeline; Loll-Krippleber, Raphaël; Commere, Pierre-Henri; Maufrais, Corinne; Sertour, Natacha; Schwartz, Katja; Sherlock, Gavin; Bougnoux, Marie-Elisabeth; d'Enfert, Christophe; Legrand, Mélanie

    2016-10-11

    The diploid genome of the yeast Candida albicans is highly plastic, exhibiting frequent loss-of-heterozygosity (LOH) events. To provide a deeper understanding of the mechanisms leading to LOH, we investigated the repair of a unique DNA double-strand break (DSB) in the laboratory C. albicans SC5314 strain using the I-SceI meganuclease. Upon I-SceI induction, we detected a strong increase in the frequency of LOH events at an I-SceI target locus positioned on chromosome 4 (Chr4), including events spreading from this locus to the proximal telomere. Characterization of the repair events by single nucleotide polymorphism (SNP) typing and whole-genome sequencing revealed a predominance of gene conversions, but we also observed mitotic crossover or break-induced replication events, as well as combinations of independent events. Importantly, progeny that had undergone homozygosis of part or all of Chr4 haplotype B (Chr4B) were inviable. Mining of genome sequencing data for 155 C. albicans isolates allowed the identification of a recessive lethal allele in the GPI16 gene on Chr4B unique to C. albicans strain SC5314 which is responsible for this inviability. Additional recessive lethal or deleterious alleles were identified in the genomes of strain SC5314 and two clinical isolates. Our results demonstrate that recessive lethal alleles in the genomes of C. albicans isolates prevent the occurrence of specific extended LOH events. While these and other recessive lethal and deleterious alleles are likely to accumulate in C. albicans due to clonal reproduction, their occurrence may in turn promote the maintenance of corresponding nondeleterious alleles and, consequently, heterozygosity in the C. albicans species.

  3. Analysis of Repair Mechanisms following an Induced Double-Strand Break Uncovers Recessive Deleterious Alleles in the Candida albicans Diploid Genome

    Directory of Open Access Journals (Sweden)

    Adeline Feri

    2016-10-01

    Full Text Available The diploid genome of the yeast Candida albicans is highly plastic, exhibiting frequent loss-of-heterozygosity (LOH events. To provide a deeper understanding of the mechanisms leading to LOH, we investigated the repair of a unique DNA double-strand break (DSB in the laboratory C. albicans SC5314 strain using the I-SceI meganuclease. Upon I-SceI induction, we detected a strong increase in the frequency of LOH events at an I-SceI target locus positioned on chromosome 4 (Chr4, including events spreading from this locus to the proximal telomere. Characterization of the repair events by single nucleotide polymorphism (SNP typing and whole-genome sequencing revealed a predominance of gene conversions, but we also observed mitotic crossover or break-induced replication events, as well as combinations of independent events. Importantly, progeny that had undergone homozygosis of part or all of Chr4 haplotype B (Chr4B were inviable. Mining of genome sequencing data for 155 C. albicans isolates allowed the identification of a recessive lethal allele in the GPI16 gene on Chr4B unique to C. albicans strain SC5314 which is responsible for this inviability. Additional recessive lethal or deleterious alleles were identified in the genomes of strain SC5314 and two clinical isolates. Our results demonstrate that recessive lethal alleles in the genomes of C. albicans isolates prevent the occurrence of specific extended LOH events. While these and other recessive lethal and deleterious alleles are likely to accumulate in C. albicans due to clonal reproduction, their occurrence may in turn promote the maintenance of corresponding nondeleterious alleles and, consequently, heterozygosity in the C. albicans species.

  4. Assessment of Automotive Coatings Used on Different Metallic Substrates

    Directory of Open Access Journals (Sweden)

    W. Bensalah

    2014-01-01

    Full Text Available Four epoxy primers commonly used in the automotive industry were applied by gravity pneumatic spray gun over metallic substrates, specifically, steel, electrogalvanized steel, hot-dip galvanized steel, and aluminum. A two-component polyurethane resin was used as topcoat. To evaluate the performance of the different coating systems, the treated panels were submitted to mechanical testing using Persoz hardness, impact resistance, cupping, lattice method, and bending. Tribological properties of different coating systems were conducted using pin on disc machine. Immersion tests were carried out in 5% NaCl and immersion tests in 3% NaOH solutions. Results showed which of the coating systems is more suitable for each substrate in terms of mechanical, tribological, and anticorrosive performance.

  5. 5th International Conference on Sustainable Automotive Technologies

    CERN Document Server

    Subic, Aleksandar; Trufin, Ramona

    2014-01-01

    This book captures selected peer reviewed papers presented at the 5th International Conference on Sustainable Automotive Technologies, ICSAT 2013, held in Ingolstadt, Germany. ICSAT is the state-of-the-art conference in the field of new technologies for transportation. The book brings together the work of international researchers and practitioners under the following interrelated headings: fuel transportation and storage, material recycling, manufacturing and management costs, engines and emission reduction. The book provides a very good overview of research and development activities focused on new technologies and approaches capable of meeting the challenges to sustainable mobility. About the Editors: Prof. Dr. Jörg Wellnitz is the Dean of the Faculty of Mechanical Engineering, Technische Hochschule Ingolstadt, Germany. Prof. Dr. Aleksandar Subic is the Head of the School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Australia. Ramona Trufin, M.A. is the coordinator of the Facul...

  6. Design of electromagnetic shock absorbers for automotive suspensions

    Science.gov (United States)

    Amati, Nicola; Festini, Andrea; Tonoli, Andrea

    2011-12-01

    Electromechanical dampers seem to be a valid alternative to conventional shock absorbers for automotive suspensions. They are based on linear or rotative electric motors. If they are of the DC-brushless type, the shock absorber can be devised by shunting its electric terminals with a resistive load. The damping force can be modified by acting on the added resistance. To supply the required damping force without exceeding in size and weight, a mechanical or hydraulic system that amplifies the speed is required. This paper illustrates the modelling and design of such electromechanical shock absorbers. This paper is devoted to describe an integrated design procedure of the electrical and mechanical parameters with the objective of optimising the device performance. The application to a C class front suspension car has shown promising results in terms of size, weight and performance.

  7. Graduate Automotive Technology Education (GATE) Center for Hybrid Electric Drivetrains and Control Strategies

    Energy Technology Data Exchange (ETDEWEB)

    David Holloway

    2005-09-30

    Beginning the fall semester of 1999, The University of Maryland, Departments of Mechanical and Electrical Engineering and the Institute for Systems Research served as a U.S. Department of Energy (USDOE) Graduate Automotive Technology Education (GATE) Center for Hybrid Electric Drivetrains and Control Strategies. A key goal was to produce a graduate level education program that educated and prepared students to address the technical challenges of designing and developing hybrid electric vehicles, as they progressed into the workforce. A second goal was to produce research that fostered the advancement of hybrid electric vehicles, their controls, and other related automotive technologies. Participation ended at the University of Maryland after the 2004 fall semester. Four graduate courses were developed and taught during the course of this time, two of which evolved into annually-taught undergraduate courses, namely Vehicle Dynamics and Control Systems Laboratory. Five faculty members from Mechanical Engineering, Electrical Engineering, and the Institute for Systems Research participated. Four Ph.D. degrees (two directly supported and two indirectly supported) and seven Master's degrees in Mechanical Engineering resulted from the research conducted. Research topics included thermoelectric waste heat recovery, fuel cell modeling, pre- and post-transmission hybrid powertrain control and integration, hybrid transmission design, H{sub 2}-doped combustion, and vehicle dynamics. Many of the participating students accepted positions in the automotive industry or government laboratories involved in automotive technology work after graduation. This report discusses the participating faculty, the courses developed and taught, research conducted, the students directly and indirectly supported, and the publication list. Based on this collection of information, the University of Maryland firmly believes that the key goal of the program was met and that the majority of the

  8. Intestinal obstruction repair

    Science.gov (United States)

    Repair of volvulus; Intestinal volvulus - repair; Bowel obstruction - repair ... Intestinal obstruction repair is done while you are under general anesthesia . This means you are asleep and DO NOT feel pain. ...

  9. Aortic aneurysm repair - endovascular

    Science.gov (United States)

    EVAR; Endovascular aneurysm repair - aorta; AAA repair - endovascular; Repair - aortic aneurysm - endovascular ... Endovascular aortic repair is done because your aneurysm is very large, growing quickly, or is leaking or bleeding. You may have ...

  10. Models of the behaviour of (thermally stressed) microbial spores in foods: Tools to study mechanisms of damage and repair

    NARCIS (Netherlands)

    ter Beek, A.; Hornstra, L.M.; Pandey, R.; Kallemeijn, W.W.; Smelt, J.P.P.M.; Manders, E.M.M.; Brul, S.

    2011-01-01

    The ‘Omics’ revolution has brought a wealth of new mechanistic insights in many fields of biology. It offers options to base predictions of microbial behaviour on mechanistic insight. As the cellular mechanisms involved often turn out to be highly intertwined it is crucial that model development aim

  11. Modelling, Analysis, Control and Experimental Validation of Electromechanical Valve Actuators in Automotive Systems

    OpenAIRE

    Hoyos Velasco, Carlos Ildefonso

    2011-01-01

    This Thesis is concerned with the modelling, analysis and control of novel mechatronic valve actuators for automotive systems, specifically, the control of the mechanical valves to intake and exhaust gases in Internal Combustion Engines (ICE). Scientific studies have shown that significant benefits in terms of engine efficiency and emissions can be obtained through the adoption of variable valve actuation. Current engine technology are based on the use of a mechanical driven camshaft, which i...

  12. Risk sharing in the supplier relationship: new evidence from the Japanese automotive industry

    OpenAIRE

    Okamuro, Hiroyuki

    1997-01-01

    The Japanese corporate system is assumed to contain an implicit insurance mechanism in various aspects. This paper proves the existence of risk sharing mechanism in supplier relations in a different way from the previous studies, using a unique data set of Japanese automotive parts suppliers. The results suggest that the auto makers absorb a part of the business risk of the suppliers, in spite of recent structural changes in the supplier system: The relative stability of their profit rate is ...

  13. Turbine repair process, repaired coating, and repaired turbine component

    Energy Technology Data Exchange (ETDEWEB)

    Das, Rupak; Delvaux, John McConnell; Garcia-Crespo, Andres Jose

    2015-11-03

    A turbine repair process, a repaired coating, and a repaired turbine component are disclosed. The turbine repair process includes providing a turbine component having a higher-pressure region and a lower-pressure region, introducing particles into the higher-pressure region, and at least partially repairing an opening between the higher-pressure region and the lower-pressure region with at least one of the particles to form a repaired turbine component. The repaired coating includes a silicon material, a ceramic matrix composite material, and a repaired region having the silicon material deposited on and surrounded by the ceramic matrix composite material. The repaired turbine component a ceramic matrix composite layer and a repaired region having silicon material deposited on and surrounded by the ceramic matrix composite material.

  14. Pulsed electromagnetic fields promote osteogenesis and osseointegration of porous titanium implants in bone defect repair through a Wnt/β-catenin signaling-associated mechanism

    Science.gov (United States)

    Jing, Da; Zhai, Mingming; Tong, Shichao; Xu, Fei; Cai, Jing; Shen, Guanghao; Wu, Yan; Li, Xiaokang; Xie, Kangning; Liu, Juan; Xu, Qiaoling; Luo, Erping

    2016-01-01

    Treatment of osseous defects remains a formidable clinical challenge. Porous titanium alloys (pTi) have been emerging as ideal endosseous implants due to the excellent biocompatibility and structural properties, whereas inadequate osseointegration poses risks for unreliable long-term implant stability. Substantial evidence indicates that pulsed electromagnetic fields (PEMF), as a safe noninvasive method, inhibit osteopenia/osteoporosis experimentally and clinically. We herein investigated the efficiency and potential mechanisms of PEMF on osteogenesis and osseointegration of pTi in vitro and in vivo. We demonstrate that PEMF enhanced cellular attachment and proliferation, and induced well-organized cytoskeleton for in vitro osteoblasts seeded in pTi. PEMF promoted gene expressions in Runx2, OSX, COL-1 and Wnt/β-catenin signaling. PEMF-stimulated group exhibited higher Runx2, Wnt1, Lrp6 and β-catenin protein expressions. In vivo results via μCT and histomorphometry show that 6-week and 12-week PEMF promoted osteogenesis, bone ingrowth and bone formation rate of pTi in rabbit femoral bone defect. PEMF promoted femoral gene expressions of Runx2, BMP2, OCN and Wnt/β-catenin signaling. Together, we demonstrate that PEMF improve osteogenesis and osseointegration of pTi by promoting skeletal anabolic activities through a Wnt/β-catenin signaling-associated mechanism. PEMF might become a promising biophysical modality for enhancing the repair efficiency and quality of pTi in bone defect. PMID:27555216

  15. Sliding mode observers for automotive alternator

    Science.gov (United States)

    Chen, De-Shiou

    Estimator development for synchronous rectification of the automotive alternator is a desirable approach for estimating alternator's back electromotive forces (EMFs) without a direct mechanical sensor of the rotor position. Recent theoretical studies show that estimation of the back EMF may be observed based on system's phase current model by sensing electrical variables (AC phase currents and DC bus voltage) of the synchronous rectifier. Observer design of the back EMF estimation has been developed for constant engine speed. In this work, we are interested in nonlinear observer design of the back EMF estimation for the real case of variable engine speed. Initial back EMF estimate can be obtained from a first-order sliding mode observer (SMO) based on the phase current model. A fourth-order nonlinear asymptotic observer (NAO), complemented by the dynamics of the back EMF with time-varying frequency and amplitude, is then incorporated into the observer design for chattering reduction. Since the cost of required phase current sensors may be prohibitive, the most applicable approach in real implementation by measuring DC current of the synchronous rectifier is carried out in the dissertation. It is shown that the DC link current consists of sequential "windows" with partial information of the phase currents, hence, the cascaded NAO is responsible not only for the purpose of chattering reduction but also for necessarily accomplishing the process of estimation. Stability analyses of the proposed estimators are considered for most linear and time-varying cases. The stability of the NAO without speed information is substantiated by both numerical and experimental results. Prospective estimation algorithms for the case of battery current measurements are investigated. Theoretical study indicates that the convergence of the proposed LAO may be provided by high gain inputs. Since the order of the LAO/NAO for the battery current case is one order higher than that of the link

  16. Platform Based Design for Automotive Sensor Conditioning

    CERN Document Server

    Fanucci, L; Iozzi, F; Marino, C; Rocchi, A

    2011-01-01

    In this paper a general architecture suitable to interface several kinds of sensors for automotive applications is presented. A platform based design approach is pursued to improve system performance while minimizing time-to-market.. The platform is composed by an analog front-end and a digital section. The latter is based on a microcontroller core (8051 IP by Oregano) plus a set of dedicated hardware dedicated to the complex signal processing required for sensor conditioning. The microcontroller handles also the communication with external devices (as a PC) for data output and fast prototyping. A case study is presented concerning the conditioning of a Gyro yaw rate sensor for automotive applications. Measured performance results outperform current state-of-the-art commercial devices.

  17. Automotive Stirling engine: Mod 2 design report

    Science.gov (United States)

    Nightingale, Noel P.

    1986-01-01

    The design of an automotive Stirling engine that achieves the superior fuel economy potential of the Stirling cycle is described. As the culmination of a 9-yr development program, this engine, designated the Mod 2, also nullifies arguments that Stirling engines are heavy, expensive, unreliable, demonstrating poor performance. Installed in a General Motors Chevrolet Celebrity car, this engine has a predicted combined fuel economy on unleaded gasoline of 17.5 km/l (41 mpg)- a value 50% above the current vehicle fleet average. The Mod 2 Stirling engine is a four-cylinder V-drive design with a single crankshaft. The engine is also equipped with all the controls and auxiliaries necessary for automotive operation.

  18. Lightweight Steel Solutions for Automotive Industry

    Science.gov (United States)

    Lee, Hong Woo; Kim, Gyosung; Park, Sung Ho

    2010-06-01

    Recently, improvement in fuel efficiency and safety has become the biggest issue in worldwide automotive industry. Although the regulation of environment and safety has been tightened up more and more, the majority of vehicle bodies are still manufactured from stamped steel components. This means that the optimized steel solutions enable to demonstrate its ability to reduce body weight with high crashworthiness performance instead of expensive light weight materials such as Al, Mg and composites. To provide the innovative steel solutions for automotive industry, POSCO has developed AHSS and its application technologies, which is directly connected to EVI activities. EVI is a technical cooperation program with customer covering all stages of new car project from design to mass production. Integrated light weight solutions through new forming technologies such as TWB, hydroforming and HPF are continuously developed and provided for EVI activities. This paper will discuss the detailed status of these technologies especially light weight steel solutions based on innovative technologies.

  19. Development of light metals automotive structural subsystems

    Energy Technology Data Exchange (ETDEWEB)

    Luo, A.A.; Sachdev, A.K. [General Motors Research and Development Center, Warren, MI (United States)

    2007-07-01

    Key technological developments in aluminum and magnesium alloys were reviewed in relation to the manufacturing processes that enable lightweight automotive structural subsystems. Examples included the materials and processes evolution of lightweight body structures, chassis systems, and instrument panel beams. New aluminum and magnesium alloys and manufacturing technologies used to reduce mass and improve performance in vehicle cradle structures were discussed. Hydroforming processes used to enable the use of lightweight aluminum alloy tubes in automotive body structures were also reviewed, in addition to body architectures enabled by different materials and manufacturing processes. The review noted that magnesium instrument panels are now being designed to provide significant performance improvement, reduced vibration, and enhanced crashworthiness in new automobiles. It was concluded that vehicles will incorporate more lightweight materials such as nanocomposites and aluminum and magnesium sheets. 9 refs., 10 figs.

  20. Innovation and Entrepreneurship in the Automotive Business

    DEFF Research Database (Denmark)

    2011-01-01

    invention have appropriate benefits. The timing of the dialog with a potential user or business partner is important when it comes to which issues that have highest priorities or are most frequently discussed in the organization of said user or business partner. If there exist a special issue that your idea......The global automotive business is one of the most competitive environment you can imagine. As an independent inventor or as a small development company it is very challenging to be successful in implementing new ideas and components. In this mature and somewhat conservative technical environment...... address you will have a much better access the decision making process and get enough interest for a potential business deal. After 20 years as a supplier of engineering services to the automotive industry and 10 years as head of Global R&D at Scania CV AB, I have experienced pros and cons both from...

  1. General Motors automotive fuel cell program

    Energy Technology Data Exchange (ETDEWEB)

    Fronk, M.H.

    1995-08-01

    The objectives of the second phase of the GM/DOE fuel cell program is to develop and test a 30 kW fuel cell powerplant. This powerplant will be based on a methanol fuel processor and a proton exchange membrane PM fuel cell stack. In addition, the 10 kW system developed during phase I will be used as a {open_quotes}mule{close_quotes} to test automotive components and other ancillaries, needed for transient operation.

  2. INNOVATION LEAN PRINCIPLES IN AUTOMOTIVE GREEN MANUFACTURING

    Directory of Open Access Journals (Sweden)

    Dušan Sabadka

    2014-12-01

    Full Text Available Today, industries such as automotive and manufacturing industries deal with a lot of environmental regulations. Lean is a production strategy whose fundamental principles drive the industry towards a more effective production of goods and services. The eco-efficiency concept is primary to sustainable development and intends to provide more value with less environmental impact. The aim of this study is to identify and explore the contributions of Lean to reduce environmental impacts that naturally result from industrial activity.

  3. MICROALLOYED STEELS FOR THE AUTOMOTIVE INDUSTRY

    OpenAIRE

    Debanshu Bhattacharya

    2014-01-01

    Two major drivers for the use of newer steels in the automotive industry are fuel efficiency and increased safety performance. Fuel efficiency is mainly a function of weight of steel parts, which in turn, is controlled by gauge and design. Safety is determined by the energy absorbing capacity of the steel used to make the part. All of these factors are incentives for the U.S. automakers to use both Highly Formable and Advanced High Strength Steels (AHSS) to replace the conventional ...

  4. Characterization of three-way automotive catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Kenik, E.A.; More, K.L. [Oak Ridge National Lab., TN (United States); LaBarge, W. [Delphi Automotive Systems, Flint, MI (United States)] [and others

    1997-04-01

    The CRADA between Delphi Automotive Systems (Delphi; formerly General Motors - AC Delco, Systems) and Lockheed Martin Energy Research (LMER) on automotive catalysts was completed at the end of FY96, after a ten month, no-cost extension. The CRADA was aimed at improved performance and lifetime of noble metal based three-way-catalysts (TWC), which are the primary catalytic system for automotive emission control systems. While these TWC can meet the currently required emission standards, higher than optimum noble metal loadings are often required to meet lifetime requirements. In addition, more stringent emission standards will be imposed in the near future, demanding improved performance and service life from these catalysts. Understanding the changes of TWC conversion efficiency with ageing is a critical need in improving these catalysts. Initially in a fresh catalyst, the active material is often distributed on a very fine scale, approaching single atoms or small atomic clusters. As such, a wide range of analytical techniques have been employed to provide high spatial resolution characterization of the evolving state of the catalytic material.

  5. Brake Fundamentals. Automotive Articulation Project.

    Science.gov (United States)

    Cunningham, Larry; And Others

    Designed for secondary and postsecondary auto mechanics programs, this curriculum guide contains learning exercises in seven areas: (1) brake fundamentals; (2) brake lines, fluid, and hoses; (3) drum brakes; (4) disc brake system and service; (5) master cylinder, power boost, and control valves; (6) parking brakes; and (7) trouble shooting. Each…

  6. Multifunctional Carbon Fibre Tapes for Automotive Composites

    Science.gov (United States)

    Koncherry, V.; Potluri, P.; Fernando, A.

    2016-11-01

    Cabon fibre composites are used where mechanical performance such as strength, stiffness and impact properties at low density is a critical parameter for engineering applications. Carbon fibre flat tape is one material which is traditionally used to manufacture three-dimensional composites in this area. Modifying the carbon fibre tape to incorporate other functions such as stealth, electromagnetic interference, shielding, de-icing, self-repair, energy storage, allows us to create multi-functional carbon fibre tape. Researchers have been developing such material and the technology for their manufacture in order to produce multifunctional carbon fibre based components more economically and efficiently. This paper presents the manufacturing process of a metallised carbon fibre material for a chopped fibre preforming process that uses electromagnets for preforming instead of traditional suction airflow fibre deposition. In addition, the paper further presents mechanical and magneto-static modelling that is carried out to investigate the bending properties of the material produced and its suitability for creating 3D preforms.

  7. POTENTIAL USE OF MAGNESIUM ALLOYS FOR THE AUTOMOTIVE INDUSTRY

    Directory of Open Access Journals (Sweden)

    Kudret KANDEMİR

    2003-01-01

    Full Text Available Recently, there is a high interest in using lightweight materials for automotive applications where weight reduction and improvement in comfort are needed. Magnesium alloys with excellent specific strength and stiffness properties can be comparable with steel and aluminum alloys for applications in the automotive industry. For this reason, the properties of magnesium alloys are in the focus of research. This study aims at reviewing and evaluating the prospects of magnesium alloys use and applications in the automotive industry.

  8. Models of the behaviour of (thermally stressed) microbial spores in foods: tools to study mechanisms of damage and repair.

    Science.gov (United States)

    Ter Beek, Alex; Hornstra, Luc M; Pandey, Rachna; Kallemeijn, Wouter W; Smelt, Jan P P M; Manders, Erik M M; Brul, Stanley

    2011-06-01

    The 'Omics' revolution has brought a wealth of new mechanistic insights in many fields of biology. It offers options to base predictions of microbial behaviour on mechanistic insight. As the cellular mechanisms involved often turn out to be highly intertwined it is crucial that model development aims at identifying the level of complexity that is relevant to work at. For the prediction of microbiologically stable foods insight in the behaviour of bacterial spore formers is crucial. Their chances of germination and likelihood of outgrowth are major food stability indicators, as well as the transition from outgrowth to first cell division and vegetative growth. Current available technology to assess these parameters in a time-resolved manner at the single spore level will be discussed. Tools to study molecular processes operative in heat induced damage will be highlighted.

  9. 40 CFR 426.70 - Applicability; description of the automotive glass laminating subcategory.

    Science.gov (United States)

    2010-07-01

    ... automotive glass laminating subcategory. 426.70 Section 426.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Automotive Glass Laminating Subcategory § 426.70 Applicability; description of the automotive...

  10. Final report: U.S. competitive position in automotive technologies

    Energy Technology Data Exchange (ETDEWEB)

    Albert, Michael B.; Cheney, Margaret; Thomas, Patrick; Kroll, Peter

    2002-09-30

    Patent data are presented and analyzed to assess the U.S. competitive position in eleven advanced automotive technology categories, including automotive fuel cells, hydrogen storage, advanced batteries, hybrid electric vehicles and others. Inventive activity in most of the technologies is found to be growing at a rapid pace, particularly in advanced batteries, automotive fuel cells and ultracapacitors. The U.S. is the clear leader in automotive fuel cells, on-board hydrogen storage and light weight materials. Japan leads in advanced batteries, hybrid electric vehicles, ultracapacitors, and appears to be close to overtaking the U.S. in other areas of power electronics.

  11. AUTOMOTIVE MARKET- FROM A GENERAL TO A MARKET SEGMENTATION APPROACH

    National Research Council Canada - National Science Library

    Liviana Andreea Niminet

    2014-01-01

    Automotive market and its corresponding industry are undoubtedly of outmost importance and therefore proper market segmentation is crucial for market players, potential competitors and customers as well...

  12. AUTOMOTIVE MARKET- FROM A GENERAL TO A MARKET SEGMENTATION APPROACH

    Directory of Open Access Journals (Sweden)

    Liviana Andreea Niminet

    2014-01-01

    Full Text Available Automotive market and its corresponding industry are undoubtedly of outmost importance and therefore proper market segmentation is crucial for market players, potential competitors and customers as well. Time has proved that market economic analysis often shown flaws in determining the relevant market, by using solely or mainly the geographic aspect and disregarding the importance of segments on the automotive market. For these reasons we propose a new approach of the automotive market proving the importance of proper market segmentation and defining the strategic groups within the automotive market.

  13. Aircraft Propeller Hub Repair

    Energy Technology Data Exchange (ETDEWEB)

    Muth, Thomas R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peter, William H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-02-13

    The team performed a literature review, conducted residual stress measurements, performed failure analysis, and demonstrated a solid state additive manufacturing repair technique on samples removed from a scrapped propeller hub. The team evaluated multiple options for hub repair that included existing metal buildup technologies that the Federal Aviation Administration (FAA) has already embraced, such as cold spray, high velocity oxy-fuel deposition (HVOF), and plasma spray. In addition the team helped Piedmont Propulsion Systems, LLC (PPS) evaluate three potential solutions that could be deployed at different stages in the life cycle of aluminum alloy hubs, in addition to the conventional spray coating method for repair. For new hubs, a machining practice to prevent fretting with the steel drive shaft was recommended. For hubs that were refurbished with some material remaining above the minimal material condition (MMC), a silver interface applied by an electromagnetic pulse additive manufacturing method was recommended. For hubs that were at or below the MMC, a solid state additive manufacturing technique using ultrasonic welding (UW) of thin layers of 7075 aluminum to the hub interface was recommended. A cladding demonstration using the UW technique achieved mechanical bonding of the layers showing promise as a viable repair method.

  14. Monitoring automotive oil degradation: analytical tools and onboard sensing technologies.

    Science.gov (United States)

    Mujahid, Adnan; Dickert, Franz L

    2012-09-01

    Engine oil experiences a number of thermal and oxidative phases that yield acidic products in the matrix consequently leading to degradation of the base oil. Generally, oil oxidation is a complex process and difficult to elucidate; however, the degradation pathways can be defined for almost every type of oil because they mainly depend on the mechanical status and operating conditions. The exact time of oil change is nonetheless difficult to predict, but it is of great interest from an economic and ecological point of view. In order to make a quick and accurate decision about oil changes, onboard assessment of oil quality is highly desirable. For this purpose, a variety of physical and chemical sensors have been proposed along with spectroscopic strategies. We present a critical review of all these approaches and of recent developments to analyze the exact lifetime of automotive engine oil. Apart from their potential for degradation monitoring, their limitations and future perspectives have also been investigated.

  15. Effect of low-level mechanical vibration on osteogenesis and osseointegration of porous titanium implants in the repair of long bone defects

    Science.gov (United States)

    Jing, Da; Tong, Shichao; Zhai, Mingming; Li, Xiaokang; Cai, Jing; Wu, Yan; Shen, Guanghao; Zhang, Xuhui; Xu, Qiaoling; Guo, Zheng; Luo, Erping

    2015-11-01

    Emerging evidence substantiates the potential of porous titanium alloy (pTi) as an ideal bone-graft substitute because of its excellent biocompatibility and structural properties. However, it remains a major clinical concern for promoting high-efficiency and high-quality osseointegration of pTi, which is beneficial for securing long-term implant stability. Accumulating evidence demonstrates the capacity of low-amplitude whole-body vibration (WBV) in preventing osteopenia, whereas the effects and mechanisms of WBV on osteogenesis and osseointegration of pTi remain unclear. Our present study shows that WBV enhanced cellular attachment and proliferation, and induced well-organized cytoskeleton of primary osteoblasts in pTi. WBV upregulated osteogenesis-associated gene and protein expression in primary osteoblasts, including OCN, Runx2, Wnt3a, Lrp6 and β-catenin. In vivo findings demonstrate that 6-week and 12-week WBV stimulated osseointegration, bone ingrowth and bone formation rate of pTi in rabbit femoral bone defects via μCT, histological and histomorphometric analyses. WBV induced higher ALP, OCN, Runx2, BMP2, Wnt3a, Lrp6 and β-catenin, and lower Sost and RANKL/OPG gene expression in rabbit femora. Our findings demonstrate that WBV promotes osteogenesis and osseointegration of pTi via its anabolic effect and potential anti-catabolic activity, and imply the promising potential of WBV for enhancing the repair efficiency and quality of pTi in osseous defects.

  16. United States Automotive Materials Partnership LLC (USAMP)

    Energy Technology Data Exchange (ETDEWEB)

    United States Automotive Materials Partnership

    2011-01-31

    The United States Automotive Materials Partnership LLC (USAMP) was formed in 1993 as a partnership between Chrysler Corporation, Ford Motor Company, and General Motors Corporation. Since then the U.S. Department of Energy (DOE) has supported its activities with funding and technical support. The mission of the USAMP is to conduct vehicle-oriented research and development in materials and materials processing to improve the competitiveness of the U.S. Auto Industry. Its specific goals are: (1) To conduct joint research to further the development of lightweight materials for improved automotive fuel economy; and (2) To work with the Federal government to explore opportunities for cooperative programs with the national laboratories, Federal agencies such as the DOE and universities. As a major component of the DOE's Office of FreedomCAR and Vehicle Technologies Program (FCVT) collaboration with the USAMP, the Automotive Lightweighting Materials (ALM) program focuses on the development and validation of advanced materials and manufacturing technologies to significantly reduce automotive vehicle body and chassis weight without compromising other attributes such as safety, performance, recyclability, and cost. The FCVT was announced in FY 2002 and implemented in FY 2003, as a successor of the Partnership for a New Generation of Vehicles (PNGV), largely addressed under the first Cooperative Agreement. This second USAMP Cooperative Agreement with the DOE has expanded a unique and valuable framework for collaboratively directing industry and government research efforts toward the development of technologies capable of solving important societal problems related to automobile transportation. USAMP efforts are conducted by the domestic automobile manufacturers, in collaboration with materials and manufacturing suppliers, national laboratories, universities, and other technology or trade organizations. These interactions provide a direct route for implementing newly

  17. Mechanism of repair of 5'-topoisomerase II-DNA adducts by mammalian tyrosyl-DNA phosphodiesterase 2

    Energy Technology Data Exchange (ETDEWEB)

    Schellenberg, Matthew J; Appel, C Denise; Adhikari, Sanjay; Robertson, Patrick D; Ramsden, Dale A; Williams, R Scott [NIH; (Georgetown); (UNC)

    2012-10-28

    The topoisomerase II (topo II) DNA incision-and-ligation cycle can be poisoned (for example following treatment with cancer chemotherapeutics) to generate cytotoxic DNA double-strand breaks (DSBs) with topo II covalently conjugated to DNA. Tyrosyl-DNA phosphodiesterase 2 (Tdp2) protects genomic integrity by reversing 5'-phosphotyrosyl–linked topo II–DNA adducts. Here, X-ray structures of mouse Tdp2–DNA complexes reveal that Tdp2 β–2-helix–β DNA damage–binding 'grasp', helical 'cap' and DNA lesion–binding elements fuse to form an elongated protein-DNA conjugate substrate-interaction groove. The Tdp2 DNA-binding surface is highly tailored for engagement of 5'-adducted single-stranded DNA ends and restricts nonspecific endonucleolytic or exonucleolytic processing. Structural, mutational and functional analyses support a single–metal ion catalytic mechanism for the exonuclease-endonuclease-phosphatase (EEP) nuclease superfamily and establish a molecular framework for targeted small-molecule blockade of Tdp2-mediated resistance to anticancer topoisomerase drugs.

  18. Early days of DNA repair: discovery of nucleotide excision repair and homology-dependent recombinational repair.

    Science.gov (United States)

    Rupp, W Dean

    2013-12-13

    The discovery of nucleotide excision repair in 1964 showed that DNA could be repaired by a mechanism that removed the damaged section of a strand and replaced it accurately by using the remaining intact strand as the template. This result showed that DNA could be actively metabolized in a process that had no precedent. In 1968, experiments describing postreplication repair, a process dependent on homologous recombination, were reported. The authors of these papers were either at Yale University or had prior Yale connections. Here we recount some of the events leading to these discoveries and consider the impact on further research at Yale and elsewhere.

  19. Some aspects of RNA repair and editing

    Directory of Open Access Journals (Sweden)

    Kovalchuk M. V.

    2010-11-01

    Full Text Available All cellular RNA molecules are damaged at the scale of DNA molecules, or even more. In the present review the RNA damaging agents, some mechanisms of RNA repair and editing, their difference from DNA repair mechanisms have been discussed.

  20. Optimized CRISPR-Cas9 Genome Editing for Leishmania and Its Use To Target a Multigene Family, Induce Chromosomal Translocation, and Study DNA Break Repair Mechanisms

    Science.gov (United States)

    Zhang, Wen-Wei; Lypaczewski, Patrick

    2017-01-01

    of the miltefosine transporter gene and serial transfections of an oligonucleotide donor significantly eased isolation of edited mutants. This cotargeting strategy was efficiently used to delete all 11 members of the A2 virulence gene family. This technical advancement is valuable, since there are many gene clusters and supernumerary chromosomes in the various Leishmania species and isolates. We simplified this CRISPR system by developing a gRNA and Cas9 coexpression vector which could be used to delete genes in various Leishmania species. This CRISPR system could also be used to generate specific chromosomal translocations, which will help in the study of Leishmania gene expression and transcription control. This study also provides new information about double-strand DNA break repair mechanisms in Leishmania. PMID:28124028

  1. Bond strength of repaired amalgam restorations.

    Science.gov (United States)

    Rey, Rosalia; Mondragon, Eduardo; Shen, Chiayi

    2015-01-01

    This in vitro study investigated the interfacial flexural strength (FS) of amalgam repairs and the optimal combination of repair materials and mechanical retention required for a consistent and durable repair bond. Amalgam bricks were created, each with 1 end roughened to expose a fresh surface before repair. Four groups followed separate repair protocols: group 1, bonding agent with amalgam; group 2, bonding agent with composite resin; group 3, mechanical retention (slot) with amalgam; and group 4, slot with bonding agent and amalgam. Repaired specimens were stored in artificial saliva for 1, 10, 30, 120, or 360 days before being loaded to failure in a 3-point bending test. Statistical analysis showed significant changes in median FS over time in groups 2 and 4. The effect of the repair method on the FS values after each storage period was significant for most groups except the 30-day storage groups. Amalgam-amalgam repair with adequate condensation yielded the most consistent and durable bond. An amalgam bonding agent could be beneficial when firm condensation on the repair surface cannot be achieved or when tooth structure is involved. Composite resin can be a viable option for amalgam repair in an esthetically demanding region, but proper mechanical modification of the amalgam surface and selection of the proper bonding system are essential.

  2. Thixoforming of an automotive part in A390 hypereutectic Al-Si alloy

    DEFF Research Database (Denmark)

    Kapranos, P.; Kirkwood, D.H.; Atkinson, H.V.;

    2003-01-01

    Hypereutectic aluminium–silicon alloys offer the possibility of an in situ natural composite (the silicon acting as the reinforcing phase) with properties that make them attractive for a number of automotive applications. However, conventional casting techniques result in excessive growth...... of the silicon particles in the melt, which adversely affect the mechanical properties. Thixoforming allows hypereutectic Al–Si alloys containing 40–50% fraction liquid to be shaped into complex near net shape components, whilst keeping the silicon particle size quite fine. This paper describes the development...... of a series of hypereutectic alloys based on the A390 composition (17%Si, 5%Cu, 0.5%Mg), their thixoforming, their resulting microstructures and mechanical properties. Finally the thixoforming of an automotive component using an A390 alloy is also described....

  3. Nanofluids with CNTs for automotive applications

    Science.gov (United States)

    Srinivas, V.; Moorthy, Ch. V. K. N. S. N.; Dedeepya, V.; Manikanta, P. V.; Satish, V.

    2016-04-01

    This paper summarizes a recent work on anti-corrosive and enhanced heat transfer properties of carboxylated water based nanofluids. DI water mixed with Sebacic acid (C10H18O4) as carboxylate additive is dispersed with multi walled carbon nanotubes and tested for corrosion and heat transfer characteristics. Corrosion studies made as per ASTM D 1384 show that carboxylate water dispersed with MWCNTs is resistant to corrosion and hence suitable for automotive environment. In addition to MWCNTs, carboxylated water dispersed with nano sized silver, copper and Aluminium oxide are also tested for corrosion performance but found to be giving considerable corrosion in automotive environment. The stability of MWCNT based nanofluids in terms of zeta potential is found to be good with carboxylated water compared to DI water. Significant improvement is observed in the thermal conductivity of nanofluids dispersed with MWCNTs. There is a slight increase in viscosity and marginal decrease in the specific heat of nanofluids with addition of carboxylate as well as MWCNTs. The carboxylated water is dispersed with very low mass concentration of multi walled carbon nano tubes at 0.025, 0.05 and 0.1 % and tested for heat transfer performance. The heat transfer studies are made in Reynolds number range of 2500-6000 in the developing flow regime. The heat transfer performance of nanofluids is carried out on an air cooled heat exchanger similar to an automotive radiator with incoming air velocities across radiator maintained at 5, 10 and 15 m/s. The coolant side overall heat transfer coefficient and overall heat transfer coefficient have improved markedly. It is also found that the velocity of air and flow rate of coolant plays an important role in enhancement of overall heat transfer coefficient. Stanton number correlation for the entire data has been developed. It is found that the wall temperature gradients play an important role in the enhancement of heat transfer when nanofluids are

  4. A styrene-butadiene rubber (SBR)/carbon nanotube-based smart force sensor for automotive tire deformation monitoring

    Science.gov (United States)

    Cho, Min-Young; Kim, Ji-Sik; Lee, Ho-Geun; Choi, Seung-Bok; Kim, Gi-Woo

    2016-04-01

    This paper provides a preliminary study on the piezoresistive effect of a styrene-butadiene Rubber (SBR), one of the main ingredients of automotive tire, dispersed with carbon nanotubes (CNTs) to explore its feasibility as a force sensor embedded in automotive tires. Typically, the application of CNTs has been successfully applied to the mechanical sensing technology such as a stress/strain and impact sensor. In this study, the potential of using the SBR/CNT as a force sensor for monitoring automotive tire deformation is evaluated for the first time. Experimental results show that the electrical resistance of the SBR/CNT composite changes in response to the sinusoidal loading, as well as static compressive load. These piezoresistive responses of the SBR/CNT composite will be used for sensing the tire deformation caused by the vehicle loading or cracks of tires.

  5. An Overview of NASA Automotive Component Reliability Studies

    Science.gov (United States)

    Sampson, Michael J.

    2016-01-01

    The results of NASAs studies into the appropriateness of using US Automotive electronic parts in NASA spaceflight systems will be presented. The first part of the presentation provides an overview of the United States Automotive Electronics Councils AECQ standardization program, the second part provides a summary of the results of NASAs procurement and testing experiences and other lessons learned along with preliminary test results.

  6. 76 FR 40591 - Coordinating Policies on Automotive Communities and Workers

    Science.gov (United States)

    2011-07-11

    ... Policies on Automotive Communities and Workers By the authority vested in me as President by the.... Over the last decade, the United States has experienced a decline in employment in the automotive industry and among part suppliers. This decline accelerated dramatically from 2008 to 2009, with more...

  7. Manual Drivetrain and Axles Specialist. Teacher Edition. Automotive Service Series.

    Science.gov (United States)

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This instructor's guide contains materials for teaching the manual drive trains and axle specialist component of a competency-based instructional program for students preparing for employment in the automotive service trade. It is based on National Institute of Automotive Service Excellence task lists. Six instructional units contain materials…

  8. Building best practice automotive after sales network : The Volkswagen case

    NARCIS (Netherlands)

    Mikolik, Gerlinde

    2017-01-01

    This thesis aims to analyze the service operations and networks in the automotive industry as research into the automotive After Sales service network lacks the necessary fine details and industrial feedback. Its purpose is to present the insights and lessons learned from studying the After Sales se

  9. Building best practice automotive after sales network : The Volkswagen case

    NARCIS (Netherlands)

    Mikolik, Gerlinde

    2017-01-01

    This thesis aims to analyze the service operations and networks in the automotive industry as research into the automotive After Sales service network lacks the necessary fine details and industrial feedback. Its purpose is to present the insights and lessons learned from studying the After Sales

  10. Electrohydraulic Forming of Near Net Shape Automotive Panels

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-01-01

    This factsheet describes a research project whose goal is to develop the electrohydraulic forming (EHF) process as a near net shape automotive panel manufacturing technology that simultaneously reduces the energy embedded in vehicles and the energy consumed while producing automotive structures.

  11. Dynamic characteristics of automotive steel sheets

    Directory of Open Access Journals (Sweden)

    M. Mihaliková

    2016-10-01

    Full Text Available The aim of this experimental research was to perform an analysis of deformation characteristics on two different types of steel: IF steel, and micro-alloyed steel were used automotive industry. For that purpose changes of properties of these materials were carried out by static 10-3 · s-1 and dynamic 103 · s-1 strain rate assess its plastic properties. Vickers micro hardness test was carried out by the static and dynamic loading condition and describes different hardness distribution. The higher strain hardening of materials was obtained too that was confirmed by distribution of dislocations.

  12. Characterization of three-way automotive catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Kenik, E.A.; More, K.L. [Oak Ridge National Laboratory, TN (United States); LaBarge, W. [General Motors-AC Delco Systems, Flint, MI (United States)] [and others

    1995-05-01

    This has been the second year of a CRADA between General Motors - AC Delco Systems (GM-ACDS) and Martin Marietta Energy Systems (MMES) aimed at improved performance/lifetime of platinum-rhodium based three-way-catalysts (TWC) for automotive emission control systems. While current formulations meet existing emission standards, higher than optimum Pt-Rh loadings are often required. In additionk, more stringent emission standards have been imposed for the near future, demanding improved performance and service life from these catalysts. Understanding the changes of TWC conversion efficiency with ageing is a critical need in improving these catalysts.

  13. Industrial thermoforming simulation of automotive fuel tanks

    Energy Technology Data Exchange (ETDEWEB)

    Wiesche, S. aus der [Kautex Textron GmbH and Co., Bonn (Germany)

    2004-11-01

    An industrial thermoforming simulation with regard to automotive plastic fuel tanks is presented including all relevant process stages. The radiative and conductive heat transfer during the reheat stage, the deformation and stress behaviour during the forming stage, and the final cooling stage are simulated. The modelling of the thermal and rheological behaviour of the involved material is investigated in greater detail. By means of experimental data it is found that modelling of the phase transition during the process is highly important for predicting correct wall thickness distributions. (author)

  14. Advanced Microsystems for Automotive Applications 2005

    Science.gov (United States)

    Valldorf, Jürgen; Gessner, Wolfgang

    Since 1995 the annual international forum on Advanced Microsystems for Automotive Applications (AMAA) has been held in Berlin. The event offers a unique opportunity for microsystems component developers, system suppliers and car manufacturers to show and to discuss competing technological approaches of microsystems based solutions in vehicles. The book accompanying the event has demonstrated to be an efficient instrument for the diffusion of new concepts and technology results. The present volume including the papers of the AMAA 2005 gives an overview on the state-of-the-art and outlines imminent and mid-term R&D perspectives.

  15. Advanced sheet steels for automotive applications

    Science.gov (United States)

    Fekete, James R.; Strugala, Donald C.; Yao, Zhicong

    1992-01-01

    Vacuum degassing has recently been used by sheet steel producers to improve their products' ductility and strength. Carbon contents can be reduced by an order of magnitude to less than 0.0030 wt.%. Through careful alloying and processing, a range of new steel products has been developed for the automotive industry. These products include interstitial-free, deep-drawing-quality steels; formable, high-strength, interstitial-free steels; and bake-hardenable steels. This article summarizes the chemistry and processing needed to produce these products.

  16. AGT 100 automotive gas turbine system development

    Science.gov (United States)

    Helms, H. E. G.

    1982-01-01

    General Motors is developing an automotive gas turbine system that can be an alternate powerplant for future automobiles. Work sponsored by DOE and administered by NASA Lewis Research Center is emphasizing small component aerodynamics and high-temperature structural ceramics. Reliability requirements of the AGT 100 turbine system include chemical and structural ceramic component stability in the gas turbine environment. The power train system, its configuration and schedule are presented, and its performance tested. The aerodynamic component development is reviewed with discussions on the compressor, turbine, regenerator, interturbine duct and scroll, and combustor. Ceramic component development is also reviewed, and production cost and required capital investment are taken into consideration.

  17. Environmentally responsive material to address human-system interaction in the automotive cockpit

    Science.gov (United States)

    Rehkopf, Jackie D.; Barbat, Saeed D.; Goldman, Neil M.; Samus, Marsha A.; Gold, Harris

    2001-06-01

    There is significant human-system interaction in an automotive cockpit, and for particular components this interaction can be ever-present while being transient in nature. It is envisioned that environmentally responsive materials can be used in some components to accommodate personal and transient differences in the desired human-system interaction. Systems containing responsive gels have been developed to provide user activation and adjustment of the physical properties of a particular interior automotive component. Proprietary reverse viscosification gel formulations were developed that are thermally responsive. Formulations were modified to adjust the dynamic modulus and viscosity in terms of magnitude, amount of change over the viscosification transition, and the temperature over which the transition occurs. Changes in the physical properties of two orders of magnitude and more were achieved over a narrow transition region. Preliminary human factors assessment indicates that this order of magnitude of change is desirable. As the system of responsive gel, encapsulating material and activation mechanism is developed further, additional human factors studies will refine the desired physical properties and thermal activation mechanism. Ultimately, this system will have to perform over the broad range of temperatures imposed on interior automotive components and exhibit long-term durability chemically, physically and mechanically.

  18. Eye muscle repair - discharge

    Science.gov (United States)

    ... Lazy eye repair - discharge; Strabismus repair - discharge; Extraocular muscle surgery - discharge ... You or your child had eye muscle repair surgery to correct eye muscle ... term for crossed eyes is strabismus. Children most often ...

  19. Ventral hernia repair

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/007661.htm Ventral hernia repair To use the sharing features on this page, please enable JavaScript. Ventral hernia repair is surgery to repair a ventral hernia. ...

  20. Brain aneurysm repair

    Science.gov (United States)

    ... aneurysm repair; Dissecting aneurysm repair; Endovascular aneurysm repair - brain; Subarachnoid hemorrhage - aneurysm ... Your scalp, skull, and the coverings of the brain are opened. A metal clip is placed at ...

  1. Influences of mechanical exposure biographies on physical capabilities of workers from automotive industry - a study on possible dose-response relationships and consequences for short and long term job rotation.

    Science.gov (United States)

    Rademacher, Holger; Bruder, Ralph; Sinn-Behrendt, Andrea; Landau, Kurt

    2012-01-01

    This paper describes a field study in production areas of a vehicle manufacturing plant, where 106 male workers (aged from 20 to 63 years) were examined and interviewed by the authors. Aim of study was to identify relationships between specific physical worker capabilities and doses of mechanical exposures using self-developed standardized questionnaires as well as a battery of work-specific tests. The dependent variables are different "physical capabilities", classified using a five-point rating scale with regard to the grade of limitation of the respective capability. Independent variables are "age" and specific "mechanical exposures". Several exposures were combined and multiplied with their respective durations in order to determine doses on three different body regions - back, shoulder-neck and upper limbs. There are significant positive correlations between "age" and "dose of mechanical exposure on back/shoulder-neck/upper limbs region". The analysis of the relationship between dose of exposure and different capabilities to lift or reposition loads (with variable weight) shows weak significant correlations for all three body regions. Data analysis shows no significant correlations between any dose of mechanical exposure and capabilities to work in awkward body postures.These results should be considered in age management programs when scheduling future employee assignments to workplaces, especially for production systems where manual handling tasks are dominant.

  2. Sesbania mosaic virus (SeMV infectious clone: possible mechanism of 3' and 5' end repair and role of polyprotein processing in viral replication.

    Directory of Open Access Journals (Sweden)

    Kunduri Govind

    Full Text Available Sesbania mosaic virus (SeMV is a positive stranded RNA virus belonging to the genus Sobemovirus. Construction of an infectious clone is an essential step for deciphering the virus gene functions in vivo. Using Agrobacterium based transient expression system we show that SeMV icDNA is infectious on Sesbania grandiflora and Cyamopsis tetragonoloba plants. The efficiency of icDNA infection was found to be significantly high on Cyamopsis plants when compared to that on Sesbania grandiflora. The coat protein could be detected within 6 days post infiltration in the infiltrated leaves. Different species of viral RNA (double stranded and single stranded genomic and subgenomic RNA could be detected upon northern analysis, suggesting that complete replication had taken place. Based on the analysis of the sequences at the genomic termini of progeny RNA from SeMV icDNA infiltrated leaves and those of its 3' and 5' terminal deletion mutants, we propose a possible mechanism for 3' and 5' end repair in vivo. Mutation of the cleavage sites in the polyproteins encoded by ORF 2 resulted in complete loss of infection by the icDNA, suggesting the importance of correct polyprotein processing at all the four cleavage sites for viral replication. Complementation analysis suggested that ORF 2 gene products can act in trans. However, the trans acting ability of ORF 2 gene products was abolished upon deletion of the N-terminal hydrophobic domain of polyprotein 2a and 2ab, suggesting that these products necessarily function at the replication site, where they are anchored to membranes.

  3. Stem cell therapy to protect and repair the developing brain: a review of mechanisms of action of cord blood and amnion epithelial derived cells.

    Science.gov (United States)

    Castillo-Melendez, Margie; Yawno, Tamara; Jenkin, Graham; Miller, Suzanne L

    2013-10-24

    In the research, clinical, and wider community there is great interest in the use of stem cells to reduce the progression, or indeed repair brain injury. Perinatal brain injury may result from acute or chronic insults sustained during fetal development, during the process of birth, or in the newborn period. The most readily identifiable outcome of perinatal brain injury is cerebral palsy, however, this is just one consequence in a spectrum of mild to severe neurological deficits. As we review, there are now clinical trials taking place worldwide targeting cerebral palsy with stem cell therapies. It will likely be many years before strong evidence-based results emerge from these trials. With such trials underway, it is both appropriate and timely to address the physiological basis for the efficacy of stem-like cells in preventing damage to, or regenerating, the newborn brain. Appropriate experimental animal models are best placed to deliver this information. Cell availability, the potential for immunological rejection, ethical, and logistical considerations, together with the propensity for native cells to form teratomas, make it unlikely that embryonic or fetal stem cells will be practical. Fortunately, these issues do not pertain to the use of human amnion epithelial cells (hAECs), or umbilical cord blood (UCB) stem cells that are readily and economically obtained from the placenta and umbilical cord discarded at birth. These cells have the potential for transplantation to the newborn where brain injury is diagnosed or even suspected. We will explore the novel characteristics of hAECs and undifferentiated UCB cells, as well as UCB-derived endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs), and how immunomodulation and anti-inflammatory properties are principal mechanisms of action that are common to these cells, and which in turn may ameliorate the cerebral hypoxia and inflammation that are final pathways in the pathogenesis of perinatal brain

  4. Stem cell therapy to protect and repair the developing brain: a review of mechanisms of action of cord blood and amnion epithelial derived cells

    Directory of Open Access Journals (Sweden)

    Margie eCastillo-Melendez

    2013-10-01

    Full Text Available In the research, clinical and wider community there is great interest in the use of stem cells to reduce the progression, or indeed repair brain injury. Perinatal brain injury may result from acute or chronic insults sustained during fetal development, during the process of birth, or in the newborn period. The most readily identifiable outcome of perinatal brain injury is cerebral palsy, however this is just one consequence in a spectrum of mild to severe neurological deficits. As we review, there are now clinical trials taking place worldwide targeting cerebral palsy with stem cell therapies. It will likely be many years before strong evidence-based results emerge from these trials. With such trials underway, it is both appropriate and timely to address the physiological basis for the efficacy of stem-like cells in preventing damage to, or regenerating, the newborn brain. Appropriate experimental animal models are best placed to deliver this information. Cell availability, the potential for immunological rejection, ethical and logistical considerations, together with the propensity for native cells to form terratomas, make it unlikely that embryonic or fetal stem cells will be practical. Fortunately, these issues do not pertain to the use of human amnion epithelial cells (hAECs, or umbilical cord blood (UCB stem cells that are readily and economically obtained from the placenta and umbilical cord discarded at birth. These cells have the potential for transplantation to the newborn where brain injury is diagnosed or even suspected. We will explore the novel characteristics of hAECs and undifferentiated UCB cells, as well as UCB-derived endothelial progenitor cells and mesenchymal stem cells, and how immunomodulation and anti-inflammatory properties are principal mechanisms of action that are common to these cells, and which in turn may ameliorate the cerebral hypoxia and inflammation that are final pathways in the pathogenesis of perinatal brain

  5. 基于数控等离子耐磨技术的综采中部槽修复%Fully mechanized coal mining central trough repair based on numerical control plasma wear resistance technology

    Institute of Scientific and Technical Information of China (English)

    李龑鹏; 丁紫阳; 王腾飞

    2015-01-01

    in order to solve the problem of mechanized coal mining central trough easy to wear and short life, numerical control plasma wear resistance technology was used to repair central trough of fully mechanized coal mining. and numerical control plasma wear resistance technology and equipment are studied and applied. The results showed that numerical control plasma wear resistance technology is suitable for the repair mechanized coal mining central trough, and this method to repair the central trough can increase the life about 2 times. Moreover, it has a good economic and social beneifts.%为了解决煤矿综采中部槽易磨损、使用寿命短的问题,采用数控等离子耐磨技术修复综采中部槽,通过对数控等离子耐磨技术及设备进行研究并应用。结果表明:数控等离子耐磨技术适合于综采中部槽的修复,且该方法修复后中部槽使用寿命提高了约2倍,具有较好的经济效益和社会效益。

  6. Long-Time Stability of Ni-Ti-Shape Memory Alloys for Automotive Safety Systems

    Science.gov (United States)

    Strittmatter, Joachim; Gümpel, Paul

    2011-07-01

    In automotive a lot of electromagnetically, pyrotechnically or mechanically driven actuators are integrated to run comfort systems and to control safety systems in modern passenger cars. Using shape memory alloys (SMA) the existing systems could be simplified, performing the same function through new mechanisms with reduced size, weight, and costs. A drawback for the use of SMA in safety systems is the lack of materials knowledge concerning the durability of the switching function (long-time stability of the shape memory effect). Pedestrian safety systems play a significant role to reduce injuries and fatal casualties caused by accidents. One automotive safety system for pedestrian protection is the bonnet lifting system. Based on such an application, this article gives an introduction to existing bonnet lifting systems for pedestrian protection, describes the use of quick changing shape memory actuators and the results of the study concerning the long-time stability of the tested NiTi-wires. These wires were trained, exposed up to 4 years at elevated temperatures (up to 140 °C) and tested regarding their phase change temperatures, times, and strokes. For example, it was found that A P-temperature is shifted toward higher temperatures with longer exposing periods and higher temperatures. However, in the functional testing plant a delay in the switching time could not be detected. This article gives some answers concerning the long-time stability of NiTi-wires that were missing till now. With this knowledge, the number of future automotive applications using SMA can be increased. It can be concluded, that the use of quick changing shape memory actuators in safety systems could simplify the mechanism, reduce maintenance and manufacturing costs and should be insertable also for other automotive applications.

  7. Improvement of adhesion performance of mortar-repair interface with inducing crack path into repair

    Directory of Open Access Journals (Sweden)

    A. Satoh

    2015-10-01

    Full Text Available The most important performance for repair materials is adhesion to the substrate. The authors experimentally find out that high modulus fine aggregates in repair material enhance strength of it as well as the strength of the interface repaired with it, compared to the ordinary repair without fine aggregates. This paper elaborates the mechanisms for that with fractographic observation and FEM analysis based on the results of experiment. Also the authors discuss the ways for enhancing the strength and ductility of the repaired mortar

  8. Requirements for future automotive batteries - a snapshot

    Science.gov (United States)

    Karden, Eckhard; Shinn, Paul; Bostock, Paul; Cunningham, James; Schoultz, Evan; Kok, Daniel

    Introduction of new fuel economy, performance, safety, and comfort features in future automobiles will bring up many new, power-hungry electrical systems. As a consequence, demands on automotive batteries will grow substantially, e.g. regarding reliability, energy throughput (shallow-cycle life), charge acceptance, and high-rate partial state-of-charge (HRPSOC) operation. As higher voltage levels are mostly not an economically feasible alternative for the short term, the existing 14 V electrical system will have to fulfil these new demands, utilizing advanced 12 V energy storage devices. The well-established lead-acid battery technology is expected to keep playing a key role in this application. Compared to traditional starting-lighting-ignition (SLI) batteries, significant technological progress has been achieved or can be expected, which improve both performance and service life. System integration of the storage device into the vehicle will become increasingly important. Battery monitoring systems (BMS) are expected to become a commodity, penetrating the automotive volume market from both highly equipped premium cars and dedicated fuel-economy vehicles (e.g. stop/start). Battery monitoring systems will allow for more aggressive battery operating strategies, at the same time improving the reliability of the power supply system. Where a single lead-acid battery cannot fulfil the increasing demands, dual-storage systems may form a cost-efficient extension. They consist either of two lead-acid batteries or of a lead-acid battery plus another storage device.

  9. Energy economics of automotive power generation

    Energy Technology Data Exchange (ETDEWEB)

    Tipler, W.

    1975-01-01

    Replacement of 50 percent of the liquid fuels used in static industrial applications by solid fuel would reduce the crude oil offtake by 17 percent; elimination of the demand for high octane gasoline would increase the thermal efficiency of the production of road fuels by 5 percent; replacement of the gasoline engine by diesel or stratified charge engines could reduce the total consumption of automotive fuels by 20 and 10 percent, respectively, and reduce refinery intake by over 25 and 20 percent, respectively; adequate gasoline substitutes can be produced from coal using known technology, but the over-all thermal efficiency of this use of coal is unacceptable because of the 30 to 40 percent efficiency of the fuel production process and the moderate fuel economy of the gasoline engine; replacement of the gasoline engine by the diesel engine could reduce the consumption of coal for automotive purposes by 20 percent and replacement of both by the spark-assisted diesel engine could reduce consumption by 60 percent; the Stirling engine is comparable to the spark-assisted diesel but is bulky and unproven.

  10. Pedestrian recognition using automotive radar sensors

    Science.gov (United States)

    Bartsch, A.; Fitzek, F.; Rasshofer, R. H.

    2012-09-01

    The application of modern series production automotive radar sensors to pedestrian recognition is an important topic in research on future driver assistance systems. The aim of this paper is to understand the potential and limits of such sensors in pedestrian recognition. This knowledge could be used to develop next generation radar sensors with improved pedestrian recognition capabilities. A new raw radar data signal processing algorithm is proposed that allows deep insights into the object classification process. The impact of raw radar data properties can be directly observed in every layer of the classification system by avoiding machine learning and tracking. This gives information on the limiting factors of raw radar data in terms of classification decision making. To accomplish the very challenging distinction between pedestrians and static objects, five significant and stable object features from the spatial distribution and Doppler information are found. Experimental results with data from a 77 GHz automotive radar sensor show that over 95% of pedestrians can be classified correctly under optimal conditions, which is compareable to modern machine learning systems. The impact of the pedestrian's direction of movement, occlusion, antenna beam elevation angle, linear vehicle movement, and other factors are investigated and discussed. The results show that under real life conditions, radar only based pedestrian recognition is limited due to insufficient Doppler frequency and spatial resolution as well as antenna side lobe effects.

  11. Performance evaluation of an automotive thermoelectric generator

    Science.gov (United States)

    Dubitsky, Andrei O.

    Around 40% of the total fuel energy in typical internal combustion engines (ICEs) is rejected to the environment in the form of exhaust gas waste heat. Efficient recovery of this waste heat in automobiles can promise a fuel economy improvement of 5%. The thermal energy can be harvested through thermoelectric generators (TEGs) utilizing the Seebeck effect. In the present work, a versatile test bench has been designed and built in order to simulate conditions found on test vehicles. This allows experimental performance evaluation and model validation of automotive thermoelectric generators. An electrically heated exhaust gas circuit and a circulator based coolant loop enable integrated system testing of hot and cold side heat exchangers, thermoelectric modules (TEMs), and thermal interface materials at various scales. A transient thermal model of the coolant loop was created in order to design a system which can maintain constant coolant temperature under variable heat input. Additionally, as electrical heaters cannot match the transient response of an ICE, modelling was completed in order to design a relaxed exhaust flow and temperature history utilizing the system thermal lag. This profile reduced required heating power and gas flow rates by over 50%. The test bench was used to evaluate a DOE/GM initial prototype automotive TEG and validate analytical performance models. The maximum electrical power generation was found to be 54 W with a thermal conversion efficiency of 1.8%. It has been found that thermal interface management is critical for achieving maximum system performance, with novel designs being considered for further improvement.

  12. Graduate Automotive Technology Education (GATE) Center

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey Hodgson; David Irick

    2005-09-30

    The Graduate Automotive Technology Education (GATE) Center at the University of Tennessee, Knoxville has completed its sixth year of operation. During this period the Center has involved thirteen GATE Fellows and ten GATE Research Assistants in preparing them to contribute to advanced automotive technologies in the center's focus area: hybrid drive trains and control systems. Eighteen GATE students have graduated, and three have completed their course work requirements. Nine faculty members from three departments in the College of Engineering have been involved in the GATE Center. In addition to the impact that the Center has had on the students and faculty involved, the presence of the center has led to the acquisition of resources that probably would not have been obtained if the GATE Center had not existed. Significant industry interaction such as internships, equipment donations, and support for GATE students has been realized. The value of the total resources brought to the university (including related research contracts) exceeds $4,000,000. Problem areas are discussed in the hope that future activities may benefit from the operation of the current program.

  13. Autologous chondrocyte implantation: superior biologic properties of hyaline cartilage repairs.

    Science.gov (United States)

    Henderson, Ian; Lavigne, Patrick; Valenzuela, Herminio; Oakes, Barry

    2007-02-01

    Information regarding the quality of autologous chondrocyte implantation repair is needed to determine whether the current autologous chondrocyte implantation surgical technology and the subsequent biologic repair processes are capable of reliably forming durable hyaline or hyaline-like cartilage in vivo. We report and analyze the properties and qualities of autologous chondrocyte implantation repairs. We evaluated 66 autologous chondrocyte implantation repairs in 57 patients, 55 of whom had histology, indentometry, and International Cartilage Repair Society repair scoring at reoperation for mechanical symptoms or pain. International Knee Documentation Committee scores were used to address clinical outcome. Maximum stiffness, normalized stiffness, and International Cartilage Repair Society repair scoring were higher for hyaline articular cartilage repairs compared with fibrocartilage, with no difference in clinical outcome. Reoperations revealed 32 macroscopically abnormal repairs (Group B) and 23 knees with normal-looking repairs in which symptoms leading to arthroscopy were accounted for by other joint disorders (Group A). In Group A, 65% of repairs were either hyaline or hyaline-like cartilage compared with 28% in Group B. Autologous chondrocyte repairs composed of fibrocartilage showed more morphologic abnormalities and became symptomatic earlier than hyaline or hyaline-like cartilage repairs. The hyaline articular cartilage repairs had biomechanical properties comparable to surrounding cartilage and superior to those associated with fibrocartilage repairs.

  14. Understanding factors that influence protective glove use among automotive spray painters.

    Science.gov (United States)

    Ceballos, Diana; Reeb-Whitaker, Carolyn; Glazer, Patricia; Murphy-Robinson, Helen; Yost, Michael

    2014-01-01

    Dermal contact with isocyanate-based coatings may lead to systemic respiratory sensitization. The most common isocyanates found in sprayed automotive coatings are monomeric and oligomeric 1,6-hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI). Most spray painters use thin (4-5 mil) latex gloves that are not effective at preventing dermal exposures when spraying isocyanate paints. Personal interviews with collision repair industry personnel and focus groups with spray painters were held to characterize risk awareness, to examine perceptions and challenges concerning protective glove use and selection, and to generate ideas for protective glove use interventions. The most popular gloves among spray painters were thin (4-5 mil) and thick (14 mil) latex. We found that medium to thick (6-8 mil) nitrile were not always perceived as comfortable and were expected to be more expensive than thin (4-5 mil) latex gloves. Of concern is the user's difficulty in distinguishing between nitrile and latex gloves; latex gloves are now sold in different colors including blue, which has traditionally been associated with nitrile gloves. Even though spray painters were familiar with the health hazards related to working with isocyanate paints, most were not always aware that dermal exposure to isocyanates could contribute to the development of occupational asthma. There is a need for more research to identify dermal materials that are protective against sprayed automotive coatings. Automotive spray painters and their employers need to be educated in the selection and use of protective gloves, specifically on attributes such as glove material, color, and thickness.

  15. Improving the effectiveness of FMEA analysis in automotive – a case study

    Directory of Open Access Journals (Sweden)

    Ványi Gábor

    2016-06-01

    Full Text Available Many industries, for example automotive, have well defined product development process definitions and risk evaluation methods. The FMEA (Failure Mode and Effects Analysis is a first line risk analysis method in design, which has been implemented in development and production since decades. Although the first applications were focusing on mechanical and electrical design and functionalities, today, software components are implemented in many modern vehicle systems. However, standards or industry specific associations do not specify any “best practice” how to design the interactions of multiple entities in one model. This case study focuses on modelling interconnections and on the improvement of the FMEA modelling process in the automotive. Selecting and grouping software components for the analysis is discussed, but software architect design patterns are excluded from the study.

  16. Rotordynamics of Automotive Turbochargers Linear and Nonlinear Rotordynamics – Bearing Design – Rotor Balancing

    CERN Document Server

    Nguyen-Schäfer, Hung

    2012-01-01

    This book deals with rotordynamics of automotive turbochargers while encompassing the analysis of the dynamics of rotating machines at very high rotor speeds of 300,000 rpm and above. This interdisciplinary field involves 1. thermodynamics and turbo-matching knowledge to compute working conditions of turbochargers, 2. fluid and bearing dynamics to calculate various operating thrust loads and to design the rotating floating ring bearings (two-oil-film bearings), and 3. tribology to improve the rotor stability and to reduce the bearing friction. Mathematical background in modeling and simulation methods is necessary; however, the prerequisites have been kept to a minimum. The book addresses both practitioners working in the field of rotordynamics of automotive turbochargers and graduate students in mechanical engineering.

  17. Preliminary Results from Duplex Procedure for Obtain of Fe Based Materials for Automotive Applications

    Science.gov (United States)

    Crăciun, R. C.; Stanciu, S.; Geantă, V.; Voiculescu, I.; Manole, V.; Gârneţ, I. A.; Alexandru, A.; Cimpoesu, N.; Săndulache, F.

    2017-06-01

    Abstract Iron based materials still represent a high percentage from metallic materials used in industry, in general, and in automotive industry, in particular. In this case we used a duplex process in order to obtain the FeMnSiAl experimental alloy for a more efficient use of various units. In the first stage iron, manganese, silicon and aluminum were melted and mixed together using arc melting technology and for the second stage the alloy was re-melt for homogeneity in an induction furnace. Chemical composition, after each melting step, was analyzed using EDS Bruker detector for various areas and microstructural characterization using SEM, VegaTescan LMH II with SE detector, equipment. This alloy is proposed as a metallic approach of mechanical dumpers used in automotive industry for low and medium impact contacts.

  18. Base excision repair in sugarcane

    Directory of Open Access Journals (Sweden)

    Agnez-Lima Lucymara F.

    2001-01-01

    Full Text Available DNA damage can be induced by a large number of physical and chemical agents from the environment as well as compounds produced by cellular metabolism. This type of damage can interfere with cellular processes such as replication and transcription, resulting in cell death and/or mutations. The low frequency of mutagenesis in cells is due to the presence of enzymatic pathways which repair damaged DNA. Several DNA repair genes (mainly from bacteria, yeasts and mammals have been cloned and their products characterized. The high conservation, especially in eukaryotes, of the majority of genes related to DNA repair argues for their importance in the maintenance of life on earth. In plants, our understanding of DNA repair pathways is still very poor, the first plant repair genes having only been cloned in 1997 and the mechanisms of their products have not yet been characterized. The objective of our data mining work was to identify genes related to the base excision repair (BER pathway, which are present in the database of the Sugarcane Expressed Sequence Tag (SUCEST Project. This search was performed by tblastn program. We identified sugarcane clusters homologous to the majority of BER proteins used in the analysis and a high degree of conservation was observed. The best results were obtained with BER proteins from Arabidopsis thaliana. For some sugarcane BER genes, the presence of more than one form of mRNA is possible, as shown by the occurrence of more than one homologous EST cluster.

  19. Price auditing research of equipment repair based on the price formation mechanism of target price%目标价格形成机制下的装备修理价格审核研究

    Institute of Scientific and Technical Information of China (English)

    陈雪曼; 孙胜祥

    2011-01-01

    In order to promote the development of the price aduting of equipment repair and increase the beneficial cost of equipment repair based on the analysis of the target price, this paper explains how to use the price formation mechanism of target price during the price management of equipment repair, discusses the change of price aduiting work, and last bring forward some suggestions on how to put the price formation mechanism of target price into effect.%为促进装备修理价格审核工作的发展,提高装备修理费用的使用效益,通过对目标价格的相关分析,说明了如何在装备修理价格管理中运用目标价格的价格形成机制,并对新的价格机制下审价工作的改变进行了研究,提出了实施目标价格的价格形成机制的几点建议。

  20. United States Automotive Materials Partnership LLC (USAMP)

    Energy Technology Data Exchange (ETDEWEB)

    United States Automotive Materials Partnership

    2011-01-31

    The United States Automotive Materials Partnership LLC (USAMP) was formed in 1993 as a partnership between Chrysler Corporation, Ford Motor Company, and General Motors Corporation. Since then the U.S. Department of Energy (DOE) has supported its activities with funding and technical support. The mission of the USAMP is to conduct vehicle-oriented research and development in materials and materials processing to improve the competitiveness of the U.S. Auto Industry. Its specific goals are: (1) To conduct joint research to further the development of lightweight materials for improved automotive fuel economy; and (2) To work with the Federal government to explore opportunities for cooperative programs with the national laboratories, Federal agencies such as the DOE and universities. As a major component of the DOE's Office of FreedomCAR and Vehicle Technologies Program (FCVT) collaboration with the USAMP, the Automotive Lightweighting Materials (ALM) program focuses on the development and validation of advanced materials and manufacturing technologies to significantly reduce automotive vehicle body and chassis weight without compromising other attributes such as safety, performance, recyclability, and cost. The FCVT was announced in FY 2002 and implemented in FY 2003, as a successor of the Partnership for a New Generation of Vehicles (PNGV), largely addressed under the first Cooperative Agreement. This second USAMP Cooperative Agreement with the DOE has expanded a unique and valuable framework for collaboratively directing industry and government research efforts toward the development of technologies capable of solving important societal problems related to automobile transportation. USAMP efforts are conducted by the domestic automobile manufacturers, in collaboration with materials and manufacturing suppliers, national laboratories, universities, and other technology or trade organizations. These interactions provide a direct route for implementing newly

  1. Bosch automotive electrics and automotive electronics systems and components, networking and hybrid drive

    CERN Document Server

    2014-01-01

    The significance of electrical and electronic systems has increased considerably in the last few years and this trend is set to continue. The characteristics feature of innovative systems is the fact that they can work together in a network. This requires powerful bus systems that the electronic control units can use to exchange information. Networking and the various bus systems used in motor vehicles are the prominent new topic in the 5th edition of the "Automotive Electric, Automotive Electronics" technical manual. The existing chapters have also been updated, so that this new edition brings the reader up to date on the subjects of electrical and electronic systems in the motor vehicle. Content Electrical and electronical systems – Basic principles of networking - Examples of networked vehicles – Bus systems – Architecture of electronic systems – Mechatronics – Elektronics – Electronic control Units – Software – Sensors – Actuators – Hybrid drives – Vehicle electrical system – Start...

  2. Repairs the added value of being wrong

    CERN Document Server

    Brandt, Patrick

    2013-01-01

    Grammatical structures connect systems of thought and articulation, the conditions of which hardly seem to fit each other. Repairs are productive mechanisms that solve translation problems between modules or levels by adapting derivations or representations to requirements that have to be met unconditionally. Compensating for derivational and interpretive defects, repairs

  3. Advances in LEDs for automotive applications

    Science.gov (United States)

    Bhardwaj, Jy; Peddada, Rao; Spinger, Benno

    2016-03-01

    High power LEDs were introduced in automotive headlights in 2006-2007, for example as full LED headlights in the Audi R8 or low beam in Lexus. Since then, LED headlighting has become established in premium and volume automotive segments and beginning to enable new compact form factors such as distributed low beam and new functions such as adaptive driving beam. New generations of highly versatile high power LEDs are emerging to meet these application needs. In this paper, we will detail ongoing advances in LED technology that enable revolutionary styling, performance and adaptive control in automotive headlights. As the standards which govern the necessary lumens on the road are well established, increasing luminance enables not only more design freedom but also headlight cost reduction with space and weight saving through more compact optics. Adaptive headlighting is based on LED pixelation and requires high contrast, high luminance, smaller LEDs with high-packing density for pixelated Matrix Lighting sources. Matrix applications require an extremely tight tolerance on not only the X, Y placement accuracy, but also on the Z height of the LEDs given the precision optics used to image the LEDs onto the road. A new generation of chip scale packaged (CSP) LEDs based on Wafer Level Packaging (WLP) have been developed to meet these needs, offering a form factor less than 20% increase over the LED emitter surface footprint. These miniature LEDs are surface mount devices compatible with automated tools for L2 board direct attach (without the need for an interposer or L1 substrate), meeting the high position accuracy as well as the optical and thermal performance. To illustrate the versatility of the CSP LEDs, we will show the results of, firstly, a reflector-based distributed low beam using multiple individual cavities each with only 20mm height and secondly 3x4 to 3x28 Matrix arrays for adaptive full beam. Also a few key trends in rear lighting and impact on LED light

  4. MICROALLOYED STEELS FOR THE AUTOMOTIVE INDUSTRY

    Directory of Open Access Journals (Sweden)

    Debanshu Bhattacharya

    2014-12-01

    Full Text Available Two major drivers for the use of newer steels in the automotive industry are fuel efficiency and increased safety performance. Fuel efficiency is mainly a function of weight of steel parts, which in turn, is controlled by gauge and design. Safety is determined by the energy absorbing capacity of the steel used to make the part. All of these factors are incentives for the U.S. automakers to use both Highly Formable and Advanced High Strength Steels (AHSS to replace the conventional steels used to manufacture automotive parts in the past. AHSS is a general term used to describe various families of steels. The most common AHSS is the dual-phase steel that consists of a ferrite-martensite microstructure. These steels are characterized by high strength, good ductility, low tensile to yield strength ratio and high bake hardenability. Another class of AHSS is the complex-phase or multi-phase steel which has a complex microstructure consisting of various phase constituents and a high yield to tensile strength ratio. Transformation Induced Plasticity (TRIP steels is another class of AHSS steels finding interest among the U.S. automakers. These steels consist of a ferrite-bainite microstructure with significant amount of retained austenite phase and show the highest combination of strength and elongation, so far, among the AHSS in use. High level of energy absorbing capacity combined with a sustained level of high n value up to the limit of uniform elongation as well as high bake hardenability make these steels particularly attractive for safety critical parts and parts needing complex forming. A relatively new class of AHSS is the Quenching and Partitioning (Q&P steels. These steels seem to offer higher ductility than the dual-phase steels of similar strengths or similar ductility as the TRIP steels at higher strengths. Finally, martensitic steels with very high strengths are also in use for certain parts. The most recent initiative in the area of AHSS

  5. The effects of reconditioning by welding of crankshafts in automotive industry

    Directory of Open Access Journals (Sweden)

    O. Chivu

    2015-10-01

    Full Text Available The reconditioning by welding process applied to the crankshafts in the automotive industry can be carried out by using various reconditioning technologies that are based on different welding parameters and processes. This paper presents a comparison between Shielded Metal Arc Welding (SMAW and Welding in Gas (WIG reconditioning processes from the perspective of the metallographic analysis conducted on the zones resulted after the depositing process. The heat cycle resulted during the two welding processes influences in a different manner the welding behavior of the base material due to the occurrence of micro-structural changes in the main zones of the deposit. The occurred structural changes may influence to a significant degree the operating behavior of the structures repaired by welding.

  6. Mammalian mismatch repair

    DEFF Research Database (Denmark)

    Pena Diaz, Javier; Jiricny, Josef

    2012-01-01

    A considerable surge of interest in the mismatch repair (MMR) system has been brought about by the discovery of a link between Lynch syndrome, an inherited predisposition to cancer of the colon and other organs, and malfunction of this key DNA metabolic pathway. This review focuses on recent...... advances in our understanding of the molecular mechanisms of canonical MMR, which improves replication fidelity by removing misincorporated nucleotides from the nascent DNA strand. We also discuss the involvement of MMR proteins in two other processes: trinucleotide repeat expansion and antibody maturation...

  7. DNA-Protein Crosslink Proteolysis Repair.

    Science.gov (United States)

    Vaz, Bruno; Popovic, Marta; Ramadan, Kristijan

    2017-06-01

    Proteins that are covalently bound to DNA constitute a specific type of DNA lesion known as DNA-protein crosslinks (DPCs). DPCs represent physical obstacles to the progression of DNA replication. If not repaired, DPCs cause stalling of DNA replication forks that consequently leads to DNA double-strand breaks, the most cytotoxic DNA lesion. Although DPCs are common DNA lesions, the mechanism of DPC repair was unclear until now. Recent work unveiled that DPC repair is orchestrated by proteolysis performed by two distinct metalloproteases, SPARTAN in metazoans and Wss1 in yeast. This review summarizes recent discoveries on two proteases in DNA replication-coupled DPC repair and establishes DPC proteolysis repair as a separate DNA repair pathway for genome stability and protection from accelerated aging and cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Carbon fiber reinforced thermoplastic composites for future automotive applications

    Science.gov (United States)

    Friedrich, K.

    2016-05-01

    After a brief introduction to polymer composite properties and markets, the state of the art activities in the field of manufacturing of advanced composites for automotive applications are elucidated. These include (a) long fiber reinforced thermoplastics (LFT) for secondary automotive components, and (b) continuous carbon fiber reinforced thermosetting composites for car body applications. It is followed by future possibilities of carbon fiber reinforced thermoplastic composites for e.g. (i) crash elements, (ii) racing car seats, and (iii) production and recycling of automotive fenders.

  9. Hydrogenated nitrile rubber for improved durability of automotive rubber parts

    Energy Technology Data Exchange (ETDEWEB)

    Mirza, J.; Leibbrandt, F.; Thoermer, J.

    1987-01-01

    Rubber articles with improved heat resistance and better performance characteristics are becoming of increasing importance for the automotive industry. A new type of elastomer has therefore been developed based on saturated hydrocarbon backbone - for improved heat resistance - with nitrile side groups providing good resistance to swelling. Some of the typical characteristics of hydrogenated nitrile rubber (HNBR) vulcanizates such as good physical properties pattern at elevated low temperatures dynamic properties, ozone resistance and swelling in automotive fluids are discussed. Potential applications are suggested to improve the performance of various rubber parts used in automotive applications such as high performance seals.

  10. Cortical Button Fixation: A Better Patellar Tendon Repair?

    Science.gov (United States)

    Ode, Gabriella E; Piasecki, Dana P; Habet, Nahir A; Peindl, Richard D

    2016-10-01

    Patellar tendon ruptures require surgical repair to optimize outcomes, but no consensus exists regarding the ideal repair technique. Cortical button fixation is a secure method for tendon repair that has not been studied in patellar tendons. Cortical button repair is biomechanically superior to the standard transpatellar repair and biomechanically equivalent to suture anchor repair. Controlled laboratory study. Twenty-three fresh-frozen cadaveric knees were used to compare 3 techniques of patellar tendon repair after a simulated rupture at the inferior pole of the patella. Repairs were performed at 45° of flexion using a standard transpatellar suture repair (n = 7), polyetheretherketone (PEEK) suture anchor repair (n = 8), or cortical button repair (n = 8). All specimens were tested on a custom apparatus to simulate cyclic open kinetic chain quadriceps contraction from extension to 90(o) of flexion. Outcomes of gap formation up to 250 cycles, maximum load to failure, and mode of failure were evaluated. Cortical button repair had significantly less gap formation than anchor repair after 1 cycle (P button repair sustained significantly higher loads to failure than anchor repair and suture repair (P button repairs either failed through the suture (n = 5), secondary failure of the patellar tendon (n = 2), or subsidence of the button through the anterior cortex of the patella (n = 1). Patellar tendon repair using cortical button fixation demonstrated mechanical advantages over suture repair and anchor repair in cadaveric specimens. Cortical button fixation showed less cyclic gap formation and withstood at least twice the load to failure of the construct. The biomechanical superiority of cortical button fixation may impart clinical advantages in accelerating postoperative rehabilitation. © 2016 The Author(s).

  11. Improvement of Automotive Part Supplier Performance Evaluation

    Science.gov (United States)

    Kongmunee, Chalermkwan; Chutima, Parames

    2016-05-01

    This research investigates the problem of the part supplier performance evaluation in a major Japanese automotive plant in Thailand. Its current evaluation scheme is based on experiences and self-opinion of the evaluators. As a result, many poor performance suppliers are still considered as good suppliers and allow to supply parts to the plant without further improvement obligation. To alleviate this problem, the brainstorming session among stakeholders and evaluators are formally conducted. The result of which is the appropriate evaluation criteria and sub-criteria. The analytical hierarchy process is also used to find suitable weights for each criteria and sub-criteria. The results show that a newly developed evaluation method is significantly better than the previous one in segregating between good and poor suppliers.

  12. Spectroscopic analysis of automotive engine oil

    Science.gov (United States)

    Dahmani, Rachid; Gupta, Neelam

    2002-02-01

    Infrared absorption spectroscopy (IR) and acousto-optic tunable filter (AOTF) technology were combined to develop a portable spectrophotometer for use in engine oil analysis to identify and quantify oil contaminants and residue products, Preliminary measurements were taken with a field-portable AOTF-based spectrometer (2 to 4.5 micrometers ) and an FTIR spectrometer (2 to 25 micrometers ) for comparison. Absorption spectra of used and unused oil samples were measured and compared to determine absorption changes between the various samples resulting from oil degradation and any chemical reactions that might have taken place during high- temperature engine lubrication. These preliminary results indicate that IR spectroscopy can be used for oil quality monitoring in automotive engines, which will help predict and prevent engine failure and degradation. This work can be extended to other remote sensing applications, such as the monitoring of environmental oil spills.

  13. Advanced automotive diesel engine system study

    Science.gov (United States)

    1983-01-01

    A conceptual study of an advanced automotive diesel engine is discussed. The engine concept selected for vehicle installation was a supercharged 1.4 liter, 4 cylinder spark assisted diesel of 14:1 compression ratio. A compounding unit consisting of a Lysholm compressor and expander is connected to the engine crankshaft by a belt drive. The inlet air charge is heated by the expander exhaust gas via a heat exchanger. Four levels of technology achievement on the selected engine concept were evaluated, from state-of-the-art to the ideal case. This resulted in the fuel economy increasing from 53.2 mpg to 81.7 mpg, and the 0-60 mph time decreasing from 17.6 seconds to 10.9 seconds.

  14. Multi-channel automotive night vision system

    Science.gov (United States)

    Lu, Gang; Wang, Li-jun; Zhang, Yi

    2013-09-01

    A four-channel automotive night vision system is designed and developed .It is consist of the four active near-infrared cameras and an Mulit-channel image processing display unit,cameras were placed in the automobile front, left, right and rear of the system .The system uses near-infrared laser light source,the laser light beam is collimated, the light source contains a thermoelectric cooler (TEC),It can be synchronized with the camera focusing, also has an automatic light intensity adjustment, and thus can ensure the image quality. The principle of composition of the system is description in detail,on this basis, beam collimation,the LD driving and LD temperature control of near-infrared laser light source,four-channel image processing display are discussed.The system can be used in driver assistance, car BLIS, car parking assist system and car alarm system in day and night.

  15. An Assembly Line Balancing Problem Automotive Cables

    Directory of Open Access Journals (Sweden)

    Triki Hager

    2015-02-01

    Full Text Available In this paper, an Assembly Line Balancing Problem (ALBP is presented in a real-world automotive cables manufacturer company. This company found it necessary to balance its line, since it needs to increase the production rate. In this ALBP, the number of stations is known and the objective is to minimize cycle time where both precedence and zoning constrains must be satisfied. This problem is formulated as a binary linear program (BLP. Since this problem is NP-hard, an innovative Genetic Algorithm (GA is implemented. The full factorial design is used to obtain the better combination GA parameters and a simple convergence experimental study is performed on the stopping criteria to reduce computational time. Comparison of the proposed GA results with CPLEX software shows that, in a reasonable time, the GA generates consistent solutions that are very close to their optimal ones. Therefore, the proposed GA approach is very effective and competitive.

  16. Design of Polymer Coatings in Automotive Engines

    Institute of Scientific and Technical Information of China (English)

    LIAO Han-lin; ZHANG Ga; BORDES Jean-Michel; CHRISTIAN Coddet

    2004-01-01

    Driven by economical and ecological reasons, thermoplastics based coatings were more and more used in automotive engines. Two design concepts, flame spraying and serigraphy PEEK coatings on light metal substrate, were introduced in this paper. The friction and wear behavior of PEEK based coatings were investigated systematically. Coatings with different crystallinities can be obtained when cooling speed is controlled. Among three sprayed coatings considered with different crystallinities, the one with highest crystallinity exhibits best friction and wear behavior under dry sliding condition. Under lubricated sliding condition, however, the amorphous coating gives lower friction coefficient. The micron particles such as SiC,MoS2 and graphite in composite coatings can improve significantly the coating wear resistance and have a impact on coating friction behavior.

  17. Aero and vibroacoustics of automotive turbochargers

    CERN Document Server

    Nguyen-Schäfer, Hung

    2013-01-01

    Aero and Vibroacoustics of Automotive Turbochargers is a topic involving aspects from the working fields of thermodynamics of turbomachinery, aerodynamics, rotordynamics, and noise propagation computation.   In this broadly interdisciplinary subject, thermodynamics of turbomachinery is used to design the turbocharger and to determine its operating conditions.  Aerodynamics is needed to study the compressor flow dynamics and flow instabilities of rotating stall and surge, which can produce growling and whining-type noises. Rotordynamics is necessary to study rotor unbalance and self-excited oil-whirl instabilities, which lead to whistling and constant tone-type noises in rotating floating oil-film type bearings. For the special case of turbochargers using ball bearings, some high-order harmonic and wear noises also manifest in the rotor operating range. Lastly, noise propagation computation, based on Lighthill’s analogy, is required to investigate airborne noises produced by turbochargers in passenger vehi...

  18. Visual comparison testing of automotive paint simulation

    Science.gov (United States)

    Meyer, Gary; Fan, Hua-Tzu; Seubert, Christopher; Evey, Curtis; Meseth, Jan; Schnackenberg, Ryan

    2015-03-01

    An experiment was performed to determine whether typical industrial automotive color paint comparisons made using real physical samples could also be carried out using a digital simulation displayed on a calibrated color television monitor. A special light booth, designed to facilitate evaluation of the car paint color with reflectance angle, was employed in both the real and virtual color comparisons. Paint samples were measured using a multi-angle spectrophotometer and were simulated using a commercially available software package. Subjects performed the test quicker using the computer graphic simulation, and results indicate that there is only a small difference between the decisions made using the light booth and the computer monitor. This outcome demonstrates the potential of employing simulations to replace some of the time consuming work with real physical samples that still characterizes material appearance work in industry.

  19. Determining organic pollutants in automotive industry sludge.

    Science.gov (United States)

    Munaretto, Juliana S; Wonghon, Audrey L; von Mühlen, Carin

    2012-12-01

    In Brazil, the policy for disposing industrial sludge is changing from an emphasis on using controlled landfills to other treatment or co-processing methods; however, the monitoring of organic pollutants is not mandatory. The present study evaluated two general screening methods for organic pollutants in sludge generated in an automotive industrial complex in southern Brazil. The screening was performed using Soxhlet and sonication extractions and Gas Chromatograph coupled with Quadrupole Mass Spectrometry (GC/qMS). It was concluded that both techniques were effective and that most of the compounds identified were alkanes, phenols and esters. Important pollutants were detected in the sludge, which confirms the necessity of monitoring this type of residue.

  20. Advancing Material Models for Automotive Forming Simulations

    Science.gov (United States)

    Vegter, H.; An, Y.; ten Horn, C. H. L. J.; Atzema, E. H.; Roelofsen, M. E.

    2005-08-01

    Simulations in automotive industry need more advanced material models to achieve highly reliable forming and springback predictions. Conventional material models implemented in the FEM-simulation models are not capable to describe the plastic material behaviour during monotonic strain paths with sufficient accuracy. Recently, ESI and Corus co-operate on the implementation of an advanced material model in the FEM-code PAMSTAMP 2G. This applies to the strain hardening model, the influence of strain rate, and the description of the yield locus in these models. A subsequent challenge is the description of the material after a change of strain path. The use of advanced high strength steels in the automotive industry requires a description of plastic material behaviour of multiphase steels. The simplest variant is dual phase steel consisting of a ferritic and a martensitic phase. Multiphase materials also contain a bainitic phase in addition to the ferritic and martensitic phase. More physical descriptions of strain hardening than simple fitted Ludwik/Nadai curves are necessary. Methods to predict plastic behaviour of single-phase materials use a simple dislocation interaction model based on the formed cells structures only. At Corus, a new method is proposed to predict plastic behaviour of multiphase materials have to take hard phases into account, which deform less easily. The resulting deformation gradients create geometrically necessary dislocations. Additional micro-structural information such as morphology and size of hard phase particles or grains is necessary to derive the strain hardening models for this type of materials. Measurements available from the Numisheet benchmarks allow these models to be validated. At Corus, additional measured values are available from cross-die tests. This laboratory test can attain critical deformations by large variations in blank size and processing conditions. The tests are a powerful tool in optimising forming simulations

  1. Reactive Boride Brazing on Low-Alloy Automotive Grade Steel

    Science.gov (United States)

    Palanisamy, B.; Upadhyaya, A.

    2011-11-01

    Brazing is a widely used process to improve the performance of steels used in automotive applications. The substrate material is often exposed to harsh conditions in these applications and may affect the service life of the component. Reactive boride brazing aims to improve the mechanical properties of the substrate material by forming a ceramic-metal composite coating in a single-step process in situ. In this study, sintered Ancor 4300 low-alloy steel is used as the substrate with chromium-rich braze and chromium-lean braze materials. The mechanical properties of the brazed samples were studied in detail using microindentation hardness measurements and the transverse rupture test. The results indicate that the brazed superlayer has a 10 times higher hardness. There was a significant improvement in the transverse rupture strength of the steel brazed with the chromium-rich boride as compared to the pure substrate material. In an effort to reduce processing time, green compacts of the substrate were also directly brazed and yielded favorable results.

  2. Vibration isolation of automotive vehicle engine using periodic mounting systems

    Science.gov (United States)

    Asiri, S.

    2005-05-01

    Customer awareness and sensitivity to noise and vibration levels have been raised through increasing television advertisement, in which the vehicle noise and vibration performance is used as the main market differentiation. This awareness has caused the transportation industry to regard noise and vibration as important criteria for improving market shares. One industry that tends to be in the forefront of the technology to reduce the levels of noise and vibration is the automobile industry. Hence, it is of practical interest to reduce the vibrations induced structural responses. The automotive vehicle engine is the main source of mechanical vibrations of automobiles. The engine is vulnerable to the dynamic action caused by engine disturbance force in various speed ranges. The vibrations of the automotive vehicle engines may cause structural failure, malfunction of other parts, or discomfort to passengers because of high level noise and vibrations. The mounts of the engines act as the transmission paths of the vibrations transmitted from the excitation sources to the body of the vehicle and passengers. Therefore, proper design and control of these mounts are essential to the attenuation of the vibration of platform structures. To improve vibration resistant capacities of engine mounting systems, vibration control techniques may be used. For instance, some passive and semi-active dissipation devices may be installed at mounts to enhance vibration energy absorbing capacity. In the proposed study, a radically different concept is presented whereby periodic mounts are considered because these mounts exhibit unique dynamic characteristics that make them act as mechanical filters for wave propagation. As a result, waves can propagate along the periodic mounts only within specific frequency bands called the "Pass Bands" and wave propagation is completely blocked within other frequency bands called the "Stop Bands". The experimental arrangements, including the design of

  3. Introducing The Traceable Mechanism of Automotive Engine High Frequency Fault Automatic Detection System Design%引入可溯源机制的火电汽轮机高频故障自动检测系统设计

    Institute of Scientific and Technical Information of China (English)

    朱晓明

    2013-01-01

    火电汽轮机故障诊断系统中,存在故障信号非线性强,故障特征信号容易被干扰,很难建立稳定诊断模型。在传统的神经网络汽轮机故障诊断模型中,引入可溯源机制,利用贝叶斯网络的故障推理学习和边沿信号概率分析能力组成故障追溯模型,对汽轮机中的汽缸、隔板、喷嘴、静叶片、汽封和轴封模块高频故障信号进行追溯,再通过故障特征值和实际输出之差与设定汽轮机故障阈值的大小比较关系判断故障,实验结果表明,该方法有效地解决故障信号非线性带来的干扰,完成火电汽轮机高精度的故障检测。%Thermal power steam turbine fault diagnosis system, the fault signal nonlinear, strong fault feature signals are easy to be interference, it is difficult to establish stable diagnosis model. In the traditional steam turbine fault diagnosis model of neural network, the introduction of traceable mechanism, and the use of bayesian network inference ability to learn and edge signal probability analysis of the fault trace model, cylinder of steam turbine, baffle plate, nozzle, stator blade, seal and shaft seal module back on high frequency fault signal, again through the fault characteristic value and the difference between the actual output and setting the size of the steam turbine fault threshold comparison judgment fault, the experimental results show that this method is effective to solve the fault signal of nonlinear disturbance, complete thermal power turbine high accuracy of fault detection.

  4. 汽车产业逆向供应链知识共享激励机制研究%Research on the Incentive Mechanism of Knowledge Sharing in Reverse Supply Chain of Automotive Industry

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    为了分析制造商、回收商在技术使用阶段的影响力,以及回收商最优提成比例之间的关系,在一个汽车制造商与一个回收商组成的逆向供应链系统中,本文通过在利润函数中引入影响力参数建立制造商与回收商进行知识共享模型,得出了回收商与制造商进行知识共享的最优激励机制,分析了对称和非对称信息下不同效率回收商的提成比例与影响力参数之间的关系。研究表明回收商在对称信息下影响力越大,其提成比例越高;制造商影响力越大,提成比例越低;在非对称信息下,高效率回收商提成比例与双方影响力的关系与对称信息下的一致,低效率回收商则相反。%In view of a secondary reverse supply chain system composed of one car manufacturer and one recycler, a knowledge sharing model is built on the basis of principal-agent theory by introducing the parameter of influence, ai-ming to analyze the market influence of manufacturer and recycler in the technology using stage and the relationship be-tween optimal royalty rate of recycler.An optimal incentive mechanism of knowledge sharing between manufacturer and recycler is proposed, and relationship between optimal royalty rate of different efficiency recycler and the influence pa-rameter with symmetric and asymmetric information is analyzed.The results show that the optimal royalty rate of recycler will increase under the greater market influence in symmetric information case, while the manufacturer′s optimal royalty rate will decrease;in asymmetric information case, the results of high efficiency recycler are the same with the symmetric information case, but the low efficiency recycler′s results are opposite.

  5. Nuclear translocation contributes to regulation of DNA excision repair activities

    DEFF Research Database (Denmark)

    Knudsen, Nina Østergaard; Andersen, Sofie Dabros; Lützen, Anne;

    2009-01-01

    , it is evident that proteins from the different DNA repair pathways interact [Y. Wang, D. Cortez, P. Yazdi, N. Neff, S.J. Elledge, J. Qin, BASC, a super complex of BRCA1-associated proteins involved in the recognition and repair of aberrant DNA structures, Genes Dev. 14 (2000) 927-939; M. Christmann, M......DNA mutations are circumvented by dedicated specialized excision repair systems, such as the base excision repair (BER), nucleotide excision repair (NER), and mismatch repair (MMR) pathways. Although the individual repair pathways have distinct roles in suppressing changes in the nuclear DNA.......T. Tomicic, W.P. Roos, B. Kaina, Mechanisms of human DNA repair: an update, Toxicology 193 (2003) 3-34; N.B. Larsen, M. Rasmussen, L.J. Rasmussen, Nuclear and mitochondrial DNA repair: similar pathways? Mitochondrion 5 (2005) 89-108]. Protein interactions are not only important for function, but also...

  6. Modeling of a seated human body exposed to vertical vibrations in various automotive postures.

    Science.gov (United States)

    Liang, Cho-Chung; Chiang, Chi-Feng

    2008-04-01

    Although much research has been devoted to constructing specific models or to measuring the response characteristics of seated subjects, investigations on a mathematical human model on a seat with a backrest to evaluate vehicular riding comfort have not yet attracted the same level of attention. For the responses of a seated body to vertical vibrations, mathematical models of the mechanisms must be at least two-dimensional in the sagittal plane. In describing the motions of a seated body, two multibody models representative of the automotive postures found in the literature were investigated, one with and the other without a backrest support. Both models were modified to suitably represent the different automotive postures with and without backrest supports, and validated by various experimental data from the published literature pertaining to the same postural conditions. On the basis of the analytical study and the experimental validation, the fourteen-degrees-of-freedom model proposed in this research was found to be best fitted to the test results; therefore, this model is recommended for studying the biodynamic responses of a seated human body exposed to vertical vibrations in various automotive postures.

  7. Systems Approach for Designing Cordierite Ceramic Converters for Automotive Emissions Control

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The successful application of porous cordierite ceramic monolithic converters for automotive emissions control over the past 24 years in North America has been attributed to systems approach for optimizing the total converter package from reliability point of view. The systems approach examines the interaction between various components of monolithic converter package, namely the cordierite substrate, the alumina washcoat, the braided wire-rope end seals, the intumescent ceramic mat or steel wiremesh, and the stainless steel can, from long-term durability point of view. Such an approach has also proven successful in the Japanese, European, Korean and South American automotive industries. The key objectives of this paper are: i) to describe Corning′s methodology for assessing the impact of alumina washcoat on mechanical and thermal integrities of cordierite converter; ii) to examine the impact of mount density of ceramic mat or steel wiremesh on containment of cordierite converter against engine vibrations, gas pulsations and thermal gradients, and; iii) to analyze the impact of can design on strength and thermal shock resistance of cordierite converter. The above objectives will be illustrated by several examples of successful converter design for automobiles. This paper also addresses the Chinese automotive converter requirements and how they might be met via systems approach.

  8. Active Vibration Isolation Using an Induced Strain Actuator with Application to Automotive Seat Suspensions

    Directory of Open Access Journals (Sweden)

    Mark Malowicki

    2001-01-01

    Full Text Available Active vibration isolation of automotive seats requires actuators that achieve millimeter-range displacements and forces on the order of 300 N. Recent developments in piezoceramic actuator technology provide a means for achieving these force and displacement levels in a compact device. This work demonstrates that prestressed, curved piezoceramic actuators achieve the force and displacement levels required for active isolation of automotive seats. An estimate of the force and displacement requirements are obtained from numerical simulations on a four-degree-of-freedom car and seat model that utilize representive road accelerations as inputs. An actuator that meets these specifications is designed using piezoceramic materials. Free displacement of 4.4 mm and blocked force greater than 300 N are measured. The actuator is integrated within a dead mass setup that simulates the isolation characteristics of an automotive seat. Control experiments demonstrate that active vibration is achievable with realistic road disturbances. Feedback control is able to eliminate any amplification due to mechanical resonance and reduce the isolation frequency from 9.5 Hz to 2 Hz.

  9. Non-Destructive Thermography Analysis of Impact Damage on Large-Scale CFRP Automotive Parts

    Directory of Open Access Journals (Sweden)

    Alexander Maier

    2014-01-01

    Full Text Available Laminated composites are increasingly used in aeronautics and the wind energy industry, as well as in the automotive industry. In these applications, the construction and processing need to fulfill the highest requirements regarding weight and mechanical properties. Environmental issues, like fuel consumption and CO2-footprint, set new challenges in producing lightweight parts that meet the highly monitored standards for these branches. In the automotive industry, one main aspect of construction is the impact behavior of structural parts. To verify the quality of parts made from composite materials with little effort, cost and time, non-destructive test methods are increasingly used. A highly recommended non-destructive testing method is thermography analysis. In this work, a prototype for a car’s base plate was produced by using vacuum infusion. For research work, testing specimens were produced with the same multi-layer build up as the prototypes. These specimens were charged with defined loads in impact tests to simulate the effect of stone chips. Afterwards, the impacted specimens were investigated with thermography analysis. The research results in that work will help to understand the possible fields of application and the usage of thermography analysis as the first quick and economic failure detection method for automotive parts.

  10. Non-Destructive Thermography Analysis of Impact Damage on Large-Scale CFRP Automotive Parts

    Science.gov (United States)

    Maier, Alexander; Schmidt, Roland; Oswald-Tranta, Beate; Schledjewski, Ralf

    2014-01-01

    Laminated composites are increasingly used in aeronautics and the wind energy industry, as well as in the automotive industry. In these applications, the construction and processing need to fulfill the highest requirements regarding weight and mechanical properties. Environmental issues, like fuel consumption and CO2-footprint, set new challenges in producing lightweight parts that meet the highly monitored standards for these branches. In the automotive industry, one main aspect of construction is the impact behavior of structural parts. To verify the quality of parts made from composite materials with little effort, cost and time, non-destructive test methods are increasingly used. A highly recommended non-destructive testing method is thermography analysis. In this work, a prototype for a car’s base plate was produced by using vacuum infusion. For research work, testing specimens were produced with the same multi-layer build up as the prototypes. These specimens were charged with defined loads in impact tests to simulate the effect of stone chips. Afterwards, the impacted specimens were investigated with thermography analysis. The research results in that work will help to understand the possible fields of application and the usage of thermography analysis as the first quick and economic failure detection method for automotive parts. PMID:28788464

  11. Predictive Process Optimization for Fracture Ductility in Automotive TRIP Steels

    Science.gov (United States)

    Gong, Jiadong

    In light of the emerging challenges in the automotive industry of meeting new energy-saving and environment-friendly requirements imposed by both the government and the society, the auto makers have been working relentlessly to reduce the weight of automobiles. While steel makers pushed out a variety of novel Advanced High Strength Steels (AHSS) to serve this market with new needs, TRIP (Transformation Induced Plasticity) steels is one of the most promising materials for auto-body due to its exceptional combination of strength and formability. However, current commercial automotive TRIP steels demonstrate relatively low hole-expansion (HE) capability, which is critical in stretch forming of various auto parts. This shortcoming on ductility has been causing fracture issues in the forming process and limits the wider applications of this steel. The kinetic theory of martensitic transformations and associated transformation plasticity is applied to the optimization of transformation stability for enhanced mechanical properties in a class of high strength galvannealed TRIP steel. This research leverages newly developed characterization and simulation capabilities, supporting computational design of high-performance steels exploiting optimized transformation plasticity for desired mechanical behaviors, especially for the hole-expansion ductility. The microstructure of the automotive TRIP sheet steels was investigated, using advanced tomographic characterization including nanoscale Local Electrode Atom Probe (LEAP) microanalysis. The microstructural basis of austenite stability, the austenite carbon concentration in particular, was quantified and correlated with measured fracture ductility through transformation plasticity constitutive laws. Plastic flow stability for enhanced local fracture ductility at high strength is sought to maintain high hole-expansion ductility, through quantifying the optimal stability and the heat-treatment process to achieve it. An additional

  12. Impact behaviour of an innovative plasticized poly(vinyl chloride) for the automotive industry

    Science.gov (United States)

    Bernard, C. A.; Bahlouli, N.; Wagner-Kocher, C.; Ahzi, S.; Rémond, Y.

    2015-09-01

    Plasticized poly(vinyl chloride) (PPVC) is widely used in the automotive industry in the design of structural parts for crashworthiness applications. Thus, it is necessary to study and understand the influence of the mechanical response and mechanical properties of PPVC over a wide range of strain rate, from quasi-static to dynamic loadings. The process is also investigated using different sample thicknesses. In this work, the strain rate effect of a new PPVC is investigated over a wide range of strain rates at three temperatures and for three thicknesses. A modelling of the yield stress is also proposed. The numerical prediction is in good agreement with the experimental results.

  13. The effect of systemic administration of G-CSF on a full-thickness cartilage defect in a rabbit model MSC proliferation as presumed mechanism: G-CSF for cartilage repair.

    Science.gov (United States)

    Sasaki, T; Akagi, R; Akatsu, Y; Fukawa, T; Hoshi, H; Yamamoto, Y; Enomoto, T; Sato, Y; Nakagawa, R; Takahashi, K; Yamaguchi, S; Sasho, T

    2017-03-01

    of MSCs in a rabbit model.Cite this article: T. Sasaki, R. Akagi, Y. Akatsu, T. Fukawa, H. Hoshi, Y. Yamamoto, T. Enomoto, Y. Sato, R. Nakagawa, K. Takahashi, S. Yamaguchi, T. Sasho. The effect of systemic administration of G-CSF on a full-thickness cartilage defect in a rabbit model MSC proliferation as presumed mechanism: G-CSF for cartilage repair. Bone Joint Res 2017;6:123-131. DOI: 10.1302/2046-3758.63.BJR-2016-0083. © 2017 Sasho et al.

  14. Repair welding process of friction stir welding groove defect

    Institute of Scientific and Technical Information of China (English)

    LIU Hui-jie; ZHANG Hui-jie

    2009-01-01

    The groove defect formed in the friction stir welding dramatically deteriorates weld appearances and mechanical properties of the joints owing to its larger size and penetration. Therefore, the friction stir repair welding was utilized to remove such a groove defect, and the focus was placed on the mechanical properties and microstructural characteristics of the repair joints so as to obtain an optimum repair welding process. The experimental results indicate that the groove defect can be removed by friction stir repair welding, and the offset repair welding process is superior to the symmetrical repair welding process. In the symmetrical repair welding process, a large number of fine cavity defects and an obvious aggregation of hard-brittle phase Al2Cu occur, accordingly the mechanical properties of the repair joint are weakened, and the fracture feature of repair joint is partially brittle and partially plastic. A good-quality repair joint can be obtained by the offset repair welding process, and the repair joint is fractured near the interface between the weld nugget zone and thermal-mechanically affected zone.

  15. METHOD OF HYDROGEN FEEDING FOR AUTOMOTIVE ENGINE SUPPLY

    Directory of Open Access Journals (Sweden)

    F. Abramchuk

    2010-01-01

    Full Text Available On basis of analysis of various methods of hydrogen feeding for automotive engine supply methods of multipoint hydrogen distribution with microprocessor-based control are proposed.

  16. Conference on Future Automotive Technology Focus Electro Mobility

    CERN Document Server

    2013-01-01

    The increasing trend towards electric cars leads to several challenges for the automobile industry, research institutes and politics as well as for the society. Research and serial development move closer together to meet automotive standards with new components such as traction batteries integrated into hybrid and electrical drivetrains. Furthermore, the influence of e-mobility on the daily mobility behavior, the effects on the automotive supply chain and the impact on industrial production have to be taken into account. According to these complex aspects it is crucial to not only acquire specific knowledge in the particular fields but also to consider their functional interaction. Therefore, it seems essential to merge competence from science, economy and politics. This year, the annual „Conference on Future Automotive Technology“ as the follow-up of the „2. Automobiltechnisches Kolloquium München” focuses on the economical realization of widespread automotive electro mobility. Contents - Energy St...

  17. Springback Compensation Process for High Strength Steel Automotive Parts

    Science.gov (United States)

    Onhon, M. Fatih

    2016-08-01

    This paper is about an advanced stamping simulation methodology used in automotive industry to shorten total die manufacturing times in a new vehicle project by means of benefiting leading edge virtual try-out technology.

  18. THE AUTOMOTIVE INDUSTRY IN A NEW TEHNOLOGICAL ERA

    Directory of Open Access Journals (Sweden)

    Simona Catalina ALBULESCU

    2014-11-01

    Full Text Available The business world is changing at an impressive speed: the global financial crisis, challenging markets, technology and talent crisis have a major impact on business. The last century can be associated with the triumph of the automobile industry. At the beginning of the 21st century the automotive industry has experienced one of the largest shifts in the automotive history. The new CO2 regulations on global level have determined the automotove industry to adopt new and original technologies faster than anticipated. The emerging tendency of car sharing in larger cities added to the media information related to the negative environmental effects of car mobility generate concerns that customers were seeking a replacement to the traditional, individual car ownership. The automotive industry will face challenging years ahead taking into consideration the shifting paradigm in auto-mobility. In this context, this article aims to provide a general perspective of the tendencies in the automotive sector.

  19. THE AUTOMOTIVE INDUSTRY IN A NEW TEHNOLOGICAL ERA

    Directory of Open Access Journals (Sweden)

    Simona Catalina ALBULESCU

    2014-11-01

    Full Text Available The business world is changing at an impressive speed: the global financial crisis, challenging markets, technology and talent crisis have a major impact on business. The last century can be associated with the triumph of the automobile industry. At the beginning of the 21st century the automotive industry has experienced one of the largest shifts in the automotive history. The new CO2 regulations on global level have determined the automotove industry to adopt new and original technologies faster than anticipated. The emerging tendency of car sharing in larger cities added to the media information related to the negative environmental effects of car mobility generate concerns that customers were seeking a replacement to the traditional, individual car ownership. The automotive industry will face challenging years ahead taking into consideration the shifting paradigm in auto-mobility. In this context, this article aims to provide a general perspective of the tendencies in the automotive sector.

  20. COMPOSITION CHANGES IN REFRIGERANT BLENDS FOR AUTOMOTIVE AIR CONDITIONING

    Science.gov (United States)

    Three refrigerant blends used to replace CFC-12 in automotive air conditioners were evaluated for composition changes due to typical servicing and leakage. When recommended service procedures were followed, changes in blend compositions were relatively small. Small changes in b...

  1. Firm and Product Heterogeneity in China's Automotive Exports

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2015-12-01

    Full Text Available The main purpose of this paper is to provide an in-depth analysis of the anatomy of China's automotive exports, relying on the literature on firm and product heterogeneity. For this purpose, we use highly disaggregated HS 8-digit product-category level data collected by the Chinese Customs Office for 2000 and 2008, and we distinguish between foreign firms, domestic public firms, and domestic private firms. We also decompose automotive products into autos and auto parts and components (P/C. We then calculate both the extensive margins – number of products exported – and intensive margins – average value of exports per product – of China's automotive exports. We estimate gravity equations to assess the determinants of China's exports of autos and auto P/C. Overall, our analysis yields a number of new, interesting stylized facts about China's automotive exports by confirming the need for taking into account different types of heterogeneity in analyzing international trade.

  2. Chromatin structure and DNA damage repair

    Directory of Open Access Journals (Sweden)

    Dinant Christoffel

    2008-11-01

    Full Text Available Abstract The integrity of the genome is continuously challenged by both endogenous and exogenous DNA damaging agents. These damaging agents can induce a wide variety of lesions in the DNA, such as double strand breaks, single strand breaks, oxidative lesions and pyrimidine dimers. The cell has evolved intricate DNA damage response mechanisms to counteract the genotoxic effects of these lesions. The two main features of the DNA damage response mechanisms are cell-cycle checkpoint activation and, at the heart of the response, DNA repair. For both damage signalling and repair, chromatin remodelling is most likely a prerequisite. Here, we discuss current knowledge on chromatin remodelling with respect to the cellular response to DNA damage, with emphasis on the response to lesions resolved by nucleotide excision repair. We will discuss the role of histone modifications as well as their displacement or exchange in nucleotide excision repair and make a comparison with their requirement in transcription and double strand break repair.

  3. Databases and Bioinformatics Tools for the Study of DNA Repair

    Directory of Open Access Journals (Sweden)

    Kaja Milanowska

    2011-01-01

    Full Text Available DNA is continuously exposed to many different damaging agents such as environmental chemicals, UV light, ionizing radiation, and reactive cellular metabolites. DNA lesions can result in different phenotypical consequences ranging from a number of diseases, including cancer, to cellular malfunction, cell death, or aging. To counteract the deleterious effects of DNA damage, cells have developed various repair systems, including biochemical pathways responsible for the removal of single-strand lesions such as base excision repair (BER and nucleotide excision repair (NER or specialized polymerases temporarily taking over lesion-arrested DNA polymerases during the S phase in translesion synthesis (TLS. There are also other mechanisms of DNA repair such as homologous recombination repair (HRR, nonhomologous end-joining repair (NHEJ, or DNA damage response system (DDR. This paper reviews bioinformatics resources specialized in disseminating information about DNA repair pathways, proteins involved in repair mechanisms, damaging agents, and DNA lesions.

  4. On a learning precedence graph concept for the automotive industry

    OpenAIRE

    Hanne Klindworth; Christian Otto; Armin Scholl

    2010-01-01

    Assembly line balancing problems (ALBP) consist in assigning the total workload for manufacturing a product to stations of an assembly line as typically applied in automotive industry. The distribution of the tasks to the stations is due to restrictions which can be expressed in a precedence graph. However, automotive manufacturers usually do not know complete precedence graphs describing the production processes of their models. Unfortunately, the known approaches for graph generation are no...

  5. Joining Technology of Dissimilar Materials for Automotive Components(Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    Meung Ho Rhee; Jong Ho Song; Woo Young Chung; Young Myoung Kim

    2004-01-01

    Joining techniques of dissimilar materials for lightweight multi-material automotive body structure were discussed. The joining of 1 .4 mm thickness steel and 2 mm thickness of Al were performed by the new method that is hybrid laser welding system. After aluminum and steel were welded by laser hybrid welding process, the micro-structure investment and the micro-hardness test were carried out. Hybrid laser welding promises a bright future in joining technology of dissimilar materials for automotive components.

  6. Meeting the Embedded Design Needs of Automotive Applications

    CERN Document Server

    Lyons, Wayne

    2011-01-01

    The importance of embedded systems in driving innovation in automotive applications continues to grow. Understanding the specific needs of developers targeting this market is also helping to drive innovation in RISC core design. This paper describes how a RISC instruction set architecture has evolved to better meet those needs, and the key implementation features in two very different RISC cores are used to demonstrate the challenges of designing for real-time automotive systems.

  7. THE AUTOMOTIVE INDUSTRY IN A NEW TEHNOLOGICAL ERA

    OpenAIRE

    Simona Catalina ALBULESCU; Anca Alexandra PUCÃREA; Ovidiu DASCÃLU

    2014-01-01

    The business world is changing at an impressive speed: the global financial crisis, challenging markets, technology and talent crisis have a major impact on business. The last century can be associated with the triumph of the automobile industry. At the beginning of the 21st century the automotive industry has experienced one of the largest shifts in the automotive history. The new CO2 regulations on global level have determined the automotove industry to adopt new and original technologies f...

  8. The impact of alternate fuels on future candidate automotive engines

    Energy Technology Data Exchange (ETDEWEB)

    Rahnke, C.J.; Nichols, R.J.

    1982-06-01

    The thermal efficiency that could occur in the future for a variety of automotive engine candidates operating on conventional and alternate fuels is projected based on current automotive engine development trends and the special characteristics of the various alternate fuels. The multi-fuel engine candidates include mixture cycle and direct injection reciprocating engines, as well as adiabatic turbocompound engines and advanced gas turbine and Stirling engines. The alternate fuels considered are propane, methanol, ethanol, diesel and methane.

  9. Changes in DNA repair during aging

    Science.gov (United States)

    Gorbunova, Vera; Seluanov, Andrei; Mao, Zhiyong; Hine, Christpher

    2007-01-01

    DNA is a precious molecule. It encodes vital information about cellular content and function. There are only two copies of each chromosome in the cell, and once the sequence is lost no replacement is possible. The irreplaceable nature of the DNA sets it apart from other cellular molecules, and makes it a critical target for age-related deterioration. To prevent DNA damage cells have evolved elaborate DNA repair machinery. Paradoxically, DNA repair can itself be subject to age-related changes and deterioration. In this review we will discuss the changes in efficiency of mismatch repair (MMR), base excision repair (BER), nucleotide excision repair (NER) and double-strand break (DSB) repair systems during aging, and potential changes in DSB repair pathway usage that occur with age. Mutations in DNA repair genes and premature aging phenotypes they cause have been reviewed extensively elsewhere, therefore the focus of this review is on the comparison of DNA repair mechanisms in young versus old. PMID:17913742

  10. EGFR相关的DNA修复及放射抗拒机制研究现状%Relativity of EGFR signal as a regulatory mechanism to DNA repair and radiation resistance

    Institute of Scientific and Technical Information of China (English)

    白静; 白晓平; 赵巧艳

    2012-01-01

    目的:总结国外关于表皮生长因子受体(EGFR)通过各种信号通路调节DNA修复导致辐射抗拒相关机制的研究进展.方法:应用PubMed数据库系统,以“表皮生长因子受体、信号通路、DNA损伤修复、放射抗拒”为关键词检索2005-01-2011-12的相关文献,共检索到英文文献198篇.纳入标准:1)EGFR的表达;2)辐射抗拒和DNA损伤修复机制;3)EGFR和辐射诱导的DNA损伤修复;4)EGFR信号通路调控DNA损伤修复导致放射抗拒的可能机制.根据纳入标准,纳入分析22篇文献.结果:EGFR过表达与放化疗抗拒相关.它可以通过联接DNA蛋白激酶催化亚单位(DNA-PKcs)来调节放疗诱导的DNA损伤的修复.EGFR及其对DNA修复能力之间的分子连接可能通过该受体的一个或多个下游信号通路介导.结论:EGFR作为调节DNA损伤修复机制的信号通路与放射抗拒之间存在相关性,靶向于其中激活的信号通路可以为改善放射抗拒提供新的治疗思路.%OBJECTIVE:To sum up the articles related to improvement that epidermal growth factor receptor (EGFR) modulate DNA repair after radiation-induced damage through many signal pathways. METHODS: Epidermal growth factor receptor,signal pathway ,DNA-damage repair and radiation resistance were searched as key words by Pubmed database system from 2005-01 to 2011-12, Altogether 198 English literatures were obtained. Enrolled criteria: 1, EGFR expression; 2. mechanism of DNA repair and radiation resistances 3, EGFR and radiation resistances 4, EGFR signal as a regulatory mechanism to DNA repair and radiation resistance. By extraction according to enrolled criteria, among roughing hundreds of relative articles,46 papers were selected, and 22 papers were finally analyzed. RESULTS: EGFR Overexpres-sion is associated with resistance to chemotherapy and radiotherapy. It modulates DNA repair after radiation-induced damage through association with the catalytic subunit of DNA protein

  11. Origin of Online Metaphor Misunderstanding and Its Repair Mechanism from CBT Perspective%CBT观照下的在线隐喻误解根源及修正机制探究

    Institute of Scientific and Technical Information of China (English)

    李运河

    2012-01-01

    将概念合成理论用于隐喻构建和理解的构想模型,较为合理地解释了部分隐喻的运作机制,这为隐喻误解根源的探究和误解修正机制的假设提供了研究视角。认知图式的差异是在线隐喻误解的重要根源之一,施喻者的补救和受喻者的求同构成误解的修正机制。%The conceived model under the Conceptual Blending Theory (CBT) reasonably explains the operation mechanism of some online metaphors, and the study provides a new perspective for the origin of metaphor misunderstanding and the hypothesis of the repair mechanism. Cognitive schema differences are one of the key sources of the online metaphor misunderstanding. The repair mechanism is realized by the remedy of the metaphor provider and the identification of the metaphor recipient.

  12. RESILIENT INTERFACE DESIGN FOR SAFETY-CRITICAL EMBEDDED AUTOMOTIVE SOFTWARE

    Directory of Open Access Journals (Sweden)

    Harald Sporer

    2016-01-01

    Full Text Available The replacement of the former, purely mechanical, functionality with mechatronics-based solutions, the introduction of new propulsion technologies, and the connection of cars to their environment are just a few reasons for the continuously increasing electrical and/or electronic system (E/E system complexity in modern passenger cars. Smart methodologies and techniques have been introduced in system development to cope with these new challenges. A topic that is often neglected is the definition of the interface between the hardware and software subsystems. However, during the development of safety-critical E/E systems, according to the automotive functional safety standard ISO 26262, an unambiguous definition of the hardware-software interface (HSI has become vital. This paper presents a domain-specific modelling approach for mechatronic systems with an integrated hardware-software interface definition feature. The newly developed model-based domain-specific language is tailored to the needs of mechatronic system engineers and supports the system’s architectural design including the interface definition, with a special focus on safety-criticality.

  13. Torsional Oscillations in Automotive Transmissions: Experimental Analysis and Modelling

    Directory of Open Access Journals (Sweden)

    Enrico Galvagno

    2016-01-01

    Full Text Available The paper investigates the torsional oscillations of an automotive transmission system by means of an experimental test bench used to validate the proposed lumped parameter model. The rig consists of a Dual Clutch Transmission (DCT and a Manual Transmission (MT connected through the respective output shafts, while the excitation is provided by two electric motors, which are controlled in speed or torque. The experimental analysis includes the measurement of the external torques, applied by the two electric motors to the mechanical system, and the measurement of the system response in terms of angular speeds at different positions along the transmission line. The frequency response of the system is estimated from the experimental data and compared with the results of a 5-degree-of-freedom lumped parameter model, which proves to be adequate to describe the dynamic behaviour of the system up to a frequency of 200 Hz. The comparison between simulated results and experimental data shows good agreement, so the model can be used to predict the torsional vibrations of the transmission system in the linear field. Moreover, the effects of the nonlinearities associated with the mean value of the excitations are shown. Finally the influence of the selected gear ratio on the experimental frequency response is discussed.

  14. Multi-tool design and analysis of an automotive HUD

    Science.gov (United States)

    Irving, Bruce; Hasenauer, David; Mulder, Steve

    2016-10-01

    Design and analysis of an optical system is often a multidisciplinary task, and can involve the use of specialized software packages for imaging, mechanics, and illumination. This paper will present a case study on the design and analysis of a basic heads-up display (HUD) for automotive use. The emphasis will be on the special requirements of a HUD visual system and on the tools and techniques needed to accomplish the design. The first section of this paper will present an overview of the imaging design using commercially available imaging design software. Topics addressed in this section include modeling the windshield, visualizing the imaging performance, using constraints and freeform surfaces to improve the system, and meeting specific visual performance specifications with design/analysis methods. The second section will address the use of a CAD program to design a basic mechanical structure to support and protect the optics. This section will also discuss some of the issues and limitations involved in translating data between a CAD program and a lens design or illumination program. Typical issues that arise include the precision of optical surface prescriptions, surface and material properties, and the management of large data files. In the final section, the combined optical and mechanical package will be considered, using an illumination design program for stray light analysis. The stray light analysis will be directed primarily toward finding, visualizing, and quantifying unexpected ray paths. Techniques for sorting optical ray paths by path length, power, and elements or materials encountered will be discussed, along with methods for estimating the impact of stray light on the optical system performance.

  15. 78 FR 48467 - Delphi Automotive Systems, LLC, Products and Service Solutions Division, Including On-Site Leased...

    Science.gov (United States)

    2013-08-08

    ... Employment and Training Administration Delphi Automotive Systems, LLC, Products and Service Solutions... workers of Delphi Automotive Systems, LLC, Product and Service Solutions Division, Original Equipment... of ] Delphi Automotive Systems, LLC, Product and Service Solutions Division, including on-site...

  16. Pectus excavatum repair

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002949.htm Pectus excavatum repair To use the sharing features on this page, please enable JavaScript. Pectus excavatum repair is surgery to correct pectus excavatum . This ...

  17. Double strand break (DSB) repair in heterochromatin and heterochromatin proteins in DSB repair.

    Science.gov (United States)

    Lemaître, Charlène; Soutoglou, Evi

    2014-07-01

    Chromosomal translocations are a hallmark of cancer cells and they represent a major cause of tumorigenesis. To avoid chromosomal translocations, faithful repair of DNA double strand breaks (DSBs) has to be ensured in the context of high ordered chromatin structure. However, chromatin compaction is proposed to represent a barrier for DSB repair. Here we review the different mechanisms cells use to alleviate the heterochromatic barrier for DNA repair. At the same time, we discuss the activating role of heterochromatin-associated proteins in this process, therefore proposing that chromatin structure, more than being a simple barrier, is a key modulator of DNA repair.

  18. DNA损伤修复机制和糖尿病造成的动脉粥样硬化%Advances in the Relationship between DNA Damage Repair Mechanism and Diabetic Atherosclerosis

    Institute of Scientific and Technical Information of China (English)

    曾理(综述); 丁群芳(审校)

    2015-01-01

    Atherosclerosis and the subsequent cardiovascular complications such as myocardial infarc-tion,stroke,and coronary atherosclerotic heart disease are major causes of death among the elderly. DNA damage is the cause of the activation of the DNA damage repair pathway resulting in cell senescence,and the evidence that DNA damage and DNA damage repair mechanism participate in the process of atherosclerosis has been found in some studies. Diabetes,as a risk factor of cardiovascular disease,can lead to DNA damage, so as to accelerate the aging of blood vessels. Here is to make a review of the research development of DNA damage and DNA double strand damage repair mechanism,to provide a new method to prevent and treat ath-erosclerosis.%动脉粥样硬化及其所引起的心肌梗死、脑卒中、冠状动脉粥样硬化性心脏病(冠心病)等是导致老年人病死率增加的重要原因。 DNA损伤是激活DNA损伤修复路径导致细胞早衰的重要原因,而动脉粥样硬化中存在DNA损伤及DNA损伤修复机制参与的证据。糖尿病作为心血管疾病危险因素具有导致DNA损伤,从而加速血管老化的作用。该文综述了动脉粥样硬化疾病中DNA损伤和DNA双链损伤修复机制的研究进展,从而为防治动脉粥样硬化疾病提供新的思路。

  19. Automotive Catalyst State Diagnosis Using Microwaves

    Directory of Open Access Journals (Sweden)

    Moos Ralf

    2015-01-01

    Full Text Available The state of catalysts plays a key role in automotive exhaust gas aftertreatment. The soot or ash loading of Diesel particulate filters, the oxygen loading degree in three-way catalysts, the amount of stored ammonia in SCR catalysts, or the NOx loading degree in NOx storage catalysts are important parameters that are today determined indirectly and in a model-based manner with gas sensors installed upstream and/or downstream of the catalysts. This contribution gives an overview on a novel approach to determine the catalyst state directly by a microwave-based technique. The method exploits the fact that the catalyst housing acts as a microwave cavity resonator. As “sensing” elements, one or two simple antennas are mounted inside the catalyst canning. The electrical properties of the catalyst device (ceramic honeycomb plus coating and storage material can be measured. Preferably, the resonance characteristics, e.g., the resonance frequencies, of selected cavity modes are observed. The information on the catalyst interior obtained in such a contactless manner is very well correlated with the catalyst state as will be demonstrated for different exhaust gas aftertreatment systems.

  20. DYNAMIC TASK SCHEDULING ON MULTICORE AUTOMOTIVE ECUS

    Directory of Open Access Journals (Sweden)

    Geetishree Mishra

    2014-12-01

    Full Text Available Automobile manufacturers are controlled by stringent govt. regulations for safety and fuel emissions and motivated towards adding more advanced features and sophisticated applications to the existing electronic system. Ever increasing customer’s demands for high level of comfort also necessitate providing even more sophistication in vehicle electronics system. All these, directly make the vehicle software system more complex and computationally more intensive. In turn, this demands very high computational capability of the microprocessor used in electronic control unit (ECU. In this regard, multicore processors have already been implemented in some of the task rigorous ECUs like, power train, image processing and infotainment. To achieve greater performance from these multicore processors, parallelized ECU software needs to be efficiently scheduled by the underlaying operating system for execution to utilize all the computational cores to the maximum extent possible and meet the real time constraint. In this paper, we propose a dynamic task scheduler for multicore engine control ECU that provides maximum CPU utilization, minimized preemption overhead, minimum average waiting time and all the tasks meet their real time deadlines while compared to the static priority scheduling suggested by Automotive Open Systems Architecture (AUTOSAR