bluuebunny/crossref_metadata_2025 huggingface dataset:
Functionally Graded Bronze/Tungsten-Carbide Castings: A Characterization and Property Study
Authors: Brown Lloyd , Joyce Peter
Published: January 2013

The contact resistance and wear behavior of electrical contact surfaces is a function of hardness, applied load, and material constituents. This work presents a characterization of the mechanical and physical properties of conducting alloys fabricated as functionally graded metal matrix composites (MMCs), in particular, tungsten-carbide-filled bronze. Tungsten-carbide reinforcing particles are attractive in this application for their high hardness and concomitant wear resistance. When used as bushings, bearings, and sleeve materials, bronze has improved wear performance with the addition of tungsten-carbide particles, which improves the hardness of the contact surface. Bronze might also be attractive as a potential electrical conductor when a need exists for high-strength, wear-resistant contact surfaces as found in circuit breakers and sliding electrical contacts. An overview of two types of MMC production methods, sedimentation and centrifugal casting, is presented. MMCs fabricated using the two different methods are compared and contrasted based on physical and mechanical properties. The use of centrifugal casting provides a more effective improvement in physical and mechanical properties plus significant improvement in hardness with relatively low reduction in base-material conductivity was observed. The centrifugal casting method allows for a more tailored product in terms of locating enhanced material properties within the casting.
An Evaluation Model Using Fuzzy TOPSIS and Goal Programming for TQM Consultant Selection
Authors: Liao Chin-Nung
Published: January 2013

There are many businesses implementing total quality management (TQM) to obtain a competitive advantage and achieve business objectives. However, few businesses have addressed external consultant selection for the successful implementation of a TQM program in business quality management. The decisions made in a TQM program usually involve several objectives or criteria, and it is often necessary to make compromises when choosing from among possibly conflicting factors. In this paper, a novel method integrates the fuzzy analytical hierarchy process (FAHP), the fuzzy technique for order preference by similarity to an ideal solution (TOPSIS), and multi-segment and choice goal programming (MSCGP) methods to solve TQM consultant selection problems. A real-life case study is presented to illustrate the application of the proposed method.
Behavior of Selected Warm Mix Asphalt Additive Modified Binders and Prediction of Dynamic Modulus of the Mixes
Authors: Hossain Zahid , Zaman Musharraf
Published: January 2013

This study evaluated the viscoelastic properties of a performance grade binder modified with different dosages of a selected wax-based warm mix asphalt (WMA) additive (WMA1). The effects of reduced rolling thin film oven (RTFO) aging on the stiffness of the WMA1-modified binder were also evaluated. The viscoelastic properties of the modified binders were then used to estimate the dynamic modulus (E*) values of the WMA mixes through time temperature superposition principles. Furthermore, the effects of a selected liquid anti-stripping agent (ASA), ASA1, on the properties of the WMA1-modified binder were investigated. It was observed that the linear viscoelastic limits of WMA1-modified binders decreased with an increasing dosage of WMA1. Reduced RTFO aging was found to have significant effects on the stiffness of the WMA1-modified binder. The Hirsch model was found to provide better approximations of the E* values than the Witczak model. The Witczak model, based on dynamic shear rheometer data, was found to significantly underestimate the E* values. Although ASA1 did not reduce the beneficial effects of WMA1, it was found to increase the E* values of the WMA mix. The findings of this study are expected to offer transportation professionals a better understanding of the evaluation of WMA binders and mixes.
Performance Evaluation of Asphalt-Rubber Stone Matrix Asphalt Mixtures with Warm Mix Asphalt Additives
Authors: Cao Weidong , Liu Shutang
Published: January 2013

Three kinds of warm mix asphalt (WMA) additives (Sasobit, Evotherm, and CWA) were used in asphalt-rubber stone matrix asphalt (AR-SMA) to reduce the mixing and compaction temperatures of AR-SMA mixtures. In hot mix asphalt (HMA) mixture designs with the same air voids, the compaction temperatures of AR-SMA mixtures with different WMA additives were determined. The wheel tracking test, low temperature beam bending test, and indirect tensile test were conducted in order to evaluate the high temperature performance in terms of the resistance to rutting, the low temperature performance in terms of the resistance to cracking, and the moisture susceptibility of AR-SMA mixtures with WMA additives. The results indicate that the addition of Sasobit can improve high temperature performance significantly relative to the control mixture (AR-SMA without WMA additive), whereas the other additives yield no significant differences. Three WMA additives have significant effects on low-temperature performance, but they do not significantly increase moisture susceptibility relative to the control mixture.
Fuzzy Testing for Regression Coefficient of Fuzzy Numbers
Authors: Chen Cheng-Che , Lai Chun-Mei , Sun Wen-Chi
Published: January 2013

Statistical regression analysis is one of the important statistical methods and has been widely applied to different scientific areas. Classical regression analysis models are limited to crisp data. In practice, however, data are usually imprecise because data are difficult to measure precisely or data are determined subjectively. When dealing with fuzzy data, using classical regression analysis method to test the regression coefficient would be improper and lead to an incorrect decision. Regarding the topic of fuzzy regression analysis, most of the related literature focused on presenting methods of estimating regression coefficient in order to improve the ability of data interpreting. Unfortunately, those studies ignored the significance of the regression coefficient. That is, after constructing a fuzzy linear regression model, the regression coefficient must be tested as to whether they have the statistical meaning or not. The purpose of this paper is to develop a fuzzy testing method to test the regression coefficient with fuzzy data. Under the environment of crisp hypothesis, crisp critical value, and fuzzy data, the upper bound and lower bound of α-cuts of fuzzy testing statistics can be obtained based on α-cuts of fuzzy sets and extension principle. The membership function of fuzzy testing statistics can then be constructed. Finally, based on the membership function, a fuzzy testing method is developed to analyze those fuzzy data and further to make a statistical decision. Because the proposed testing method is based on membership function, when the data are crisp, the proposed approach can degenerate to the classical testing method.
Field Performance Assessment of Porous Asphalt Pavement Under Heavy Traffic on Yan-Tong Expressway in China
Authors: Fei Chen , Yazhou Zhu , Jun Yang , Gang Xu
Published: January 2013

With their quick drainage, enhanced skid-resistance under wet conditions, noise-reducing effect, and lessened splashing and spraying, porous asphalt pavements are now receiving more and more attention. Since research and application of porous asphalt pavements has just started in China at present, there are no corresponding design and construction specifications. Therefore, it is essential to verify the design through actual field performance monitoring on such pavement as those of the Yan-Tong Expressway. This highway is ideal for such an investigation since it includes a section of porous asphalt surface together with stone mastic asphalt and another type of dense graded surface in the same section. The major parameters of the assessment consist of permeability and skid-resistance that are essential to porous asphalt pavements and rutting depth under heavy traffic. We use a simulation model to predict the rutting depth in the short term. The results show that porous asphalt pavement performs well under the heavy truck traffic volume on the Yan-Tong Expressway.
The Temperature Measuring and Evaluating Methods Based on Infrared Thermal Image for Asphalt-Pavement Construction
Authors: Sha Aimin , Zhang Cheng , Zhou Hao
Published: January 2013

To investigate the temperature segregation of asphalt mixture and the corresponding influence on construction quality, the infrared thermal imager was used to detect the loading, unloading, and paving temperature of the asphalt mixture, and a pavement-quality indicator (PQI) test was used to work out the density of pavement, and several conclusions were obtained. During the mixture delivery, the inner temperature changes little, whereas the surface temperature decreases greatly. The temperature decrease during the process from the unloading to the paving is mainly caused by the heat convection of the surface mixture. The paving mixture temperature is not consistent and obviously there is variation in features serrated. The maximum temperature of mat occurs toward the end of the paving period for a truckload of mixture, the lowest temperature appears after the beginning of the paving period of the next truckload of mixture, and the process repeats in this way. Transversal temperature segregation is more obvious than the longitudinal one. Compaction degree distribution along the transverse has the same variation tendency with temperature distribution. Finally, the evaluation criteria for asphalt-pavement temperature segregation were proposed based on the percentage of the point numbers with more than 6°C variation of average temperature.
A New High Rutting Resistance Asphalt Mixture for Intersection Maintenance under Heavy Traffic
Authors: Guan Yongsheng , Li Hao , Zhang Zhixiang , Li Xiao-yan
Published: January 2013

Intersections of asphalt pavement are easily destroyed under heavy traffic in spite of several different technologies employed to combat such damage. Traditional high modulus asphalt mixtures were optimized according to the requirement of intersection maintenance. Penetration grade 40/60 base asphalt, an anti-rutting additive, and hard basalt aggregate were used to design a new high rutting resistance asphalt mixture. The air void content, compaction characteristics, water sensitivity, high temperature performance, and low temperature performance were investigated. Laboratory test results show that the new high rutting resistance asphalt mixture has very good high temperature performance and other beneficial characteristics. From the sensitivity analysis of the material composition, it can be deduced that the performance of the new high rutting resistance asphalt mixture is stable. Field tests also show that the new asphalt mixture is suitable for intersection maintenance of asphalt pavement and can be paved in one layer 9 to 14 cm in thickness.
Interrelationship between Tire Contact Stress and Longitudinal Construction Joint Layout in Pavement
Authors: Xu Yifeng , Cai Yang , Li Shuming
Published: January 2013

In reconstruction and rehabilitation expressway projects, there are a series of longitudinal construction joints between old and new semi-rigid bases. As the weak parts in the whole structure, the longitudinal construction joints have a trend to damage earlier than other parts. In this paper, based on a highway project, the finite element method was used to analyze the effect of longitudinal construction joint layout and bond conditions on mechanical response of semi-rigid base pavement under normal loading and heavy loading. Analysis results showed that maximum stress under heavy loading of 50 % larger than normal loading would increase 20 %. Bond condition was another significantly important factor. Under heavy loading, the bond between old parts and new parts need higher adhesion strength. The longitudinal construction joints should be set as far as possible away from the wheelpath. If its position was 50 cm away from the load, maximum stress in the structure will decrease more than 25 %.
Effects of Type and Content of Mineral Fillers on the Consistency Properties of Asphalt Mastic
Authors: Mwanza Aaron D. , Hao Peiwen , Wang Hainian
Published: January 2013

Although commercial mineral fillers have become mandatory for use in asphalt concrete mixtures by many highway agencies, the consequences of such additives have shown a great effect on the consistency properties of asphalt mastic as compared to the neat asphalt binders. A detailed analysis as to whether neat asphalt binders or asphalt mastic should provide pertinent information for material characterization and construction indices for asphalt mixtures is presented. Laboratory experiments were conducted to investigate the effects of type and content of mineral fillers on the consistency properties of asphalt mastic to the neat asphalt binder designed to meet the JTG F40-2004 specification of China. Three different mineral fillers, namely hydrated lime, pulverized limestone, and Portland cement were separately dry mixed with neat asphalt binder at dust to binder ratios ranging from 0.0 to 1.5 in ratio increments of 0.3 % by weight of asphalt. Analysis of test results shows that asphalt mastic consistency properties are well-defined linear functions of mineral filler content. Hydrated lime mastics showed significant effects on the consistency properties of the neat binder as compared to Portland cement and limestone additives tested at the same mineral filler content. Penetration and ductility of the neat binder showed a linear reduction at increased hydrated lime content estimated at 4.8(0.1 mm) and 8.2 cm per 0.1 % of hydrated lime increment respectively while softening point and apparent viscosity increased at the rate of 4.7°C and 0.1 centipoises per 0.1 % of hydrated lime increment respectively. Asphalt mixtures mixing and compaction temperatures determined from equiviscous lines of 0.17±0.02 Pa·s and 0.280±0.03 Pa·s using hydrated lime mastics show a linear increment of 7.7°C and 7.9°C per 0.1 % increment of hydrated lime respectively.
Study of Expressway Axle Load Spectrum Based on Toll Data of Jinghu Expressway
Authors: Zhang Hongbin , Ni Fujian
Published: January 2013

To describe the pavement load on the expressway, based on toll data, this paper analyzes the time and space distribution of the axle load spectrum for different vehicle types and different axle-wheel types. It studies the distribution of overload rate and overload weight for all kinds of axle-wheel types. It researches the growth rules of traffic volume and axle load. Results show that the axle load spectrum is basically same in the same direction and very different in the different directions on the Jinghu expressway, and axle load distribution of each day is similar to the one of a year. Since the Jinghu expressway was opened to traffic, the overload rate is very high and the rate is similar over the years. During the process of pavement design and maintenance, using the growth rate of traffic volume instead of that of equivalent single axle loads can lead to large errors.
Analysis of the Low-Temperature Rheological Properties of Rubberized Warm Mix Asphalt Binders
Authors: Wang Hainian , Dang Zhengxia , You Zhanping , Hao Peiwen , Huang Xiaoming
Published: January 2013

Warm mix asphalt (WMA) has generated a lot of interest worldwide based on the potential to realize environmental benefits related to lower production temperature and safe disposal of crumb rubber (tires). However, barriers to complete implementation of WMA technology still exist because of the lack of understanding of how different additives affect the performance of crumb rubber modified (CRM) binders. This paper investigates the effects of three WMA additives and crumb rubber concentration on the low-temperature performance of the CRM binders. The WMA additives used in this study were Sasobit, RH, and Advera, and the ambient 40 mesh tire rubber at different concentrations of 10 %, 15 %, 20 %, and 25 % by the weight of asphalt binder were applied in this paper. Burgers model was used to describe the relationship between deformation and time for rubberized WMA binder. The models parameters such as relaxation time, delay time, creep stiffness, m-value and m/S(t)-ratio were applied to evaluate the low-temperature performance of the rubberized WMA binders. Furthermore, the statistical analysis of variance (ANOVA) technique was applied to quantify the effects of different WMA additives and crumb rubber concentrations on the rubberized asphalt binders’ low-temperature performance. It was found that Advera could be used to enhance the low-temperature performance by enhancing the stress relaxation, whereas RH and Sasobit did not exhibit this ability, thereby weakening the low-temperature performance of the CRM binders. The crumb rubber concentration could significantly increase the rubberized WMA binders’ low-temperature performance by influencing the flexural creep stiffness of the control binders.
Laboratory Test and Numerical Simulation of Bond Performance between Basalt Fiber Reinforced Polymer Rebar and Concrete
Authors: Gu Xingyu , Dong Qiao
Published: January 2013

Because of its high strength and durability, basalt fiber reinforced polymer (BFRP) rebar is a promising alternative to the steel counterpart in reinforced concrete. Using BFRP rebar in continuously reinforced concrete pavement (CRCP) allows one to avoid the rusting of traditional steel bars caused by water that infiltrates through cracks. A sufficient bond between BFRP rebar and concrete is critical in order to apply BFRP rebar in CRCP. This paper investigates the effects of different ribs and anchorage lengths on the bond performance of BFRP rebar and concrete through a series of pull-out tests. The finite element method (FEM) is utilized to simulate the bond between BFRP rebar and concrete. The pull-out test results indicate that the bond strength changes with rib depth and rib spacing. The highest bond strength can be achieved when the rib depth is 10 % of the diameter of the BFRP rebar and the rib spacing is 80 % of the diameter. The bond strength of BFRP rebar with an anchorage length of 10 times the diameter is greater than that of BFRP rebar with an anchorage length of 5 times the diameter. The developed FEM models could provide the same bond-sliding relationship as the results of pull-out tests.
Choice of Crack Repairing Material for Asphalt Pavement Based on AHP
Authors: Bian Fenglan , Cai Haiquan
Published: January 2013

In the past decades, little attention was paid to the study on evaluation indexes of the performance of asphalt pavement crack repairing materials. In this paper, the indexes of material performance and economic evaluation based on the analysis of requirements for the crack repairing materials and the regulations are proposed. The indexes are subjected to interact, which will lead to inaccurate evaluation on the selection of crack repairing materials. Analytic hierarchy process (AHP) is employed to rank the indexes and select proper crack repairing material according to the evaluation result. The concrete steps of the AHP based model for the selection of asphalt pavement crack repairing materials is given. Finally, a practical example is employed to check the feasibility of this method.
A Study of the Semi-Perpetual Pavement Performance in Queensland
Authors: Chai Gary , Lewer Giles , Loo Yew-Chaye
Published: January 2013

This paper presents the characteristics of a long-term pavement performance site constructed with semi-perpetual materials. The design life of a perpetual pavement is normally specified as greater than 40 years. The design requires asphalt overlays at the tenth, 20th, and 30th year for extending the life of the pavement structure. A case study of a semi-perpetual pavement with an application of the stage construction technique will be presented. The study shows that the falling weight deflectometer (FWD) central deflection of the semi-perpetual pavement was reported to be between 230 to 240 microns and the deflection curvature is less than 100 microns. The horizontal tensile strain of the semi-perpetual structure varies from 102 to 187 micro-strains and the vertical compressive strain was analyzed to be between 65 to 98 micro-strains. For the structural overlay at the 30th year of service life would improve the tensile and compressive strains of the structure to the levels which would satisfy the fatigue endurance limit and limiting subgrade strains of that of a perpetual pavement. The non-linearity behaviour of the subgrade material of the semi-perpetual pavement was analyzed by computing the surface modulus using Boussinesq’s equation and material constant of subgrade material model. The results obtained from both methods showed that the subgrade material of the semi-perpetual pavement exhibits linear elastic behaviour.
Research on the Design of AR-AC13S Mixtures
Authors: Gao Ying , Cao Rongji
Published: January 2013

Lists of requirements for asphalt concrete (AC)–asphalt rubber (AR) mixture designs and construction have been published by many countries. The criteria indicated by other countries needed to be evaluated when AR-AC mixtures were used in China. This study has produced mixture design requirements for AR-AC13S mixtures (AR-AC mixtures with a 13 mm nominal maximum aggregate size and an S-shaped gradation curve) based on laboratory tests and field application in Jiangsu Province, China. The molding method of the mixture specimen, voids in mineral aggregate (VMA), air voids, mineral filler content, and gradation of the mixture are discussed. Recommendations for 5.5 % air voids and 20 % minimum VMA were made. The ratio of mineral filler to AR should be greater than 0.3 for good high temperature stability. The low temperature performance degrades with an increasing ratio of mineral filler to AR. The gradation of AR-AC13S mixture is recommended based on the analysis of VMA, voids in coarse aggregate, and mineral filler content.
Research on Design Method for Heavy-Duty Asphalt Pavements and Its Application
Authors: Sun Lijun , Liu Liping
Published: January 2013

Premature damage is currently the main problem with heavy-duty asphalt pavements. In order to decrease such premature damage, it is necessary to develop a new design system meeting the requirements of heavy-duty pavements. Based on considerable field investigations and mechanistic analysis, a five-phase design procedure, including data collection, structural combination design, structural thickness design, material testing and examination, and a final decision, was established. The procedure is a comprehensive design tool employing performance-related structural design consideration and mechanistic-based material design consideration that can link performance analysis, structural design, and material design (tests). After consideration of the extensive pavement performance data collected and subsequent analysis, relevant design equations and design criteria were proposed, including whole life asphalt pavement structural behavior equations, life cycle cost analysis models, field fatigue equations, and a shear-based rutting prediction model. As research progressed, test roads and pilot roads were constructed in ten provinces of China, and the first test road has been used successfully for 15 years.
Evaluation of Adult Body Adiposity, Size, and Shape by Stereovision Imaging
Authors: Pepper M. Reese , Freeland-Graves Jeanne H. , Yu Wurong , Stanforth Phillip R. , Xu Bugao
Published: January 2013

Overweight and obesity status is often categorized by body mass index (BMI), although this is not a measurement of body fat. Adiposity, especially in the abdominal area, is a better predictor of obesity-related diseases. However, current methods for assessment of body composition have limitations of bulkiness and expense. The purpose of this study was to evaluate a stereovision imaging system for analysis of body fat. A sample of 105 subjects was measured for body volume using the stereovision imaging system, as compared to air displacement plethysmography and hydrodensitometry. Body density was calculated from total body volume via stereovision imaging, air displacement plethysmography, and hydrodensitometry with weight. Then fat was computed via the Siri equation, and compared to body fat measurements via dual energy X-ray absorptiometry. Mean volume and fat measurements by stereovision and air displacement plethysmography did not differ significantly (mean differences −0.07 ± 0.17 L, −0.36 ± 0.82 kg, respectively, P > 0.05). Stereovision measurements of regional body volumes, lengths, and circumferences were used to develop a prediction equation via internal cross-validation for improved estimation of fat mass. This prediction equation reduced variation in individuals and improved effectiveness of the stereovision imaging system.
Performance Characterization of Bituminous Mixtures With Dolomite Sand Waste and BOF Steel Slag
Authors: Haritonovs Viktors , Zaumanis Martins , Brencis Guntis , Smirnovs Juris
Published: January 2013

The rapid growth of transport load in Latvia increases the demands for asphalt carrying capacity on large motorways. The limestone and sandstone that can be found in Latvia lack the mechanical strength and, for most of the large motorways, the aggregates are imported from other countries causing increase of the costs and growth of emissions from transportation. On the other hand, large amounts of basic oxygen furnace (BOF) steel slag aggregates with good qualities are being produced in Latvia and put to waste. During recent decades, the dolomite sand waste has been accumulating and its quantity has reached a million tons and is rapidly increasing. This huge quantity of technological waste needs to be recycled with maximum efficiency. The lack of experience on the use of steel slag and sand waste requires an accelerated evaluation of the asphalt performance-based characteristics. This paper presents the testing results of different combinations of steel slag, dolomite sand waste, and local limestone aggregates that were proportioned to develop a mixture that would satisfy the requirements of permanent deformation and fatigue. Analysis of the results showed that mixes with steel slag and local limestone in coarse portion and dolomite sand waste in sand and filler portions had high resistance to plastic deformations and good resistance to fatigue failure. These mixes can fully satisfy and, in some cases, significantly overcome the requirements of local asphalt specifications for highly loaded motorways.
Analysis of Colombian Bitumen Modified With a Nanocomposite
Authors: Quintero Luz S. , Sanabria Luis E.
Published: January 2013

Nanotechnology is giving to materials science new opportunities to develop even further all engineering materials. This paper details the preparation of a nanocomposite aimed to be used as a bitumen modifier, the modification itself, and evaluation of some rheological properties of the modified asphalts intended to build long life asphalt pavements. The bitumen was modified with a polymer nanocomposite and its conventional material (without nanostructure) at three different compositions, while their rheological behavior was compared with the asphalt conditioned under the same temperature and stirring time than the modified binders. Evaluation of the binders was carried out to the samples as prepared and to their residues after Aging—Rolling Thin Film Oven Test. According to the experimental results, the Colombian bitumen modified with the new polymer nanocomposite could undergo much less mass loss under aging conditions than the bitumen modified with its standard material getting, at the same time, higher mechanical resistance, and less accumulated strain without being stress sensitive at high temperatures.
Controlling Lubricant Degradation through Performance Specification
Authors: Fox Malcolm F.
Published: January 2013

When lubricants are used they deteriorate by evaporation, oxidation, and contamination. Today lubricants are formulated to resist these causes of deterioration in a planned manner for a stated period of operation, extent of work, distance of travel, or other measures of use. The performance specification for formulations has direct implications for operational service use—the ultimate commercial objective of manufacturing lubricants—to protect machinery from internal wear. Lubricants also reduce energy consumption through reduced friction.
Elastohydrodynamic Lubrication Film Tests and Tribological Bench Tests
Authors: Wang Q. , Tung Simon C. , Liu Y. , Zhang Y. , Zhu D.
Published: January 2013

Elastohydrodynamic lubrication (EHL) film thickness suggests the capability of a lubricant to support load under a set of hydrodynamic conditions. It is related to the rheological properties of a lubricant, contact geometry, materials properties, and operating conditions such as load, speed, and temperature. Film thickness variation with speed or load may follow the prediction made with the theory of EHL. Experimental techniques based on capacity [1-3]; electrical conductivity and contact resistance [4-6]; discharge voltage [7]; X-ray transmission [8]; indirect laser transmission [9,10]; R-C oscillation technique [11]; and optical interferometry [12–35] have been used in EHL experiments for film- thickness measurement. On the other hand, as a result of the rapid development of high-speed computers, in-depth and detailed numerical analyses of EHL problems intend to become a routine practice. More influential factors can be considered now in EHL calculations: several non-Newtonian properties of a lubricant [30,31,36–38], surface roughness [32,33,37,38], the thermal effect [34,39,40], and non-steady-state transitions [35,41,42] have been included in a number of simulation models. Moreover, mixed lubrication simulations based on digitized real rough surfaces have been conducted in wider ranges of speed and load [36,37]. This section reviews and discusses the existing techniques for EHL film-thickness measurements, views of measurement data, and comparisons of measurement results with EHL simulation solutions.
Gasoline Engine and Diesel Engine Powertrain Systems
Authors: Silva P.
Published: January 2013

Reciprocating internal combustion engines have been studied since the middle of the 19th century, but their full industrial development began with their application for vehicle propulsion in the following century. By definition, reciprocating internal combustion engines are volumetric-type engines using internal combustion and their kinematic operation is based on the alternating motion of pistons inside of cylinders. There are two basic types of reciprocating engines: Spark ignition engines and compression ignition or diesel engines. Spark ignition engines for automotive application mainly use gasoline as fuel, but they can also work on ethanol or natural gas. Diesel engines operate on diesel fuel, but in principle they can run in a dual-fuel configuration that primarily burns natural gas with a small amount of diesel pilot fuel (e.g., in some city-bus applications or in cogenerative stationary applications) [1]. As a function of the modality with which the working cycle is performed, the engines can be referred to as two- or four-stroke engines according to the number of strokes of the piston in each working cycle. The present chapter will deal mainly with four-stroke engines, which are nowadays the widespread technology for vehicles. The two-stroke spark-ignited engine is only used in very small devices because of environmental constraints whereas the two-stroke diesel engine is limited to rare applications in slow, very large marine engines [2].
Testing and Evaluation of Lubricating Greases for Rolling Element Bearings of Automotive Systems
Authors: Li Xinglin , Wu Can , Wu Baojie , Zhang Hongyu , Luo Jianbin , Feng Qiang
Published: January 2013

A rapid development has been observed in the design and manufacturing of automobiles worldwide in the past few decades, and nowadays it is confronted with more challenges because of the requirement of saving energy and protecting the environment. Theoretically, this problem can be alleviated by further reducing automotive weight, optimizing driving configuration, and using the appropriate lubricants in a certain degree. All of these require that the bearings that support the operation of the automotive parts operate very well under the conditions of very high speed and high temperature. In most cases, lubricating grease is specifically capable for lubrication of the bearings. However, because of the limited space in rolling element bearings, lubrication technology is a key factor for improving the performance of automotive components [1,2].
Gear Oil Screen Testing with FZG Back-to-Back Rig
Authors: Michaelis Klaus , O'Connor Brian M.
Published: January 2013

For better efficiency in transmissions, lower viscosity grades of gear oils and reduced oil volumes are often used. With increasing power density and extended oil drain intervals, the demands on the lubricant as a design element increase accordingly. The introduction of lubricant properties in load-carrying capacity rating requires not only knowledge of their physical properties such as viscosity, viscosity-temperature, or viscosity-pressure behavior, but also the quantitative influence of the performance additive on scuffing, wear, micropitting, and pitting of gears.
Bench Performance Test Methods for Lubricated Engine Materials
Authors: Blau Peter , Tung Simon C.
Published: January 2013

Internal combustion engines are made from a wide variety of materials. These materials must contain the fuel and combustion pressures, transmit forces to the drivetrain, deliver electrical power, and give form and structure to the engine. In the context of this chapter, some of those materials must withstand bearing pressures and rub smoothly and reliably, without seizing or excessive wear, for thousands of hours. Although bronzes and other nonferrous alloys are used, by far, iron-based metals and alloys, particularly gray cast iron, have comprised the major bearing materials. Cast iron remains available in bulk quantities, is relative inexpensive, and is familiar to engine makers. However, with a density of 7.1–7.7 g/cm3, cast iron parts are more than 1.6 times heavier than titanium, 2.5 times heavier than aluminum, and 4.2 times heavier than magnesium parts of equal size. With a drive toward reducing the weight of engines to improve fuel economy, vehicle designers are motivated to find cost-competitive, lighter weight materials for engines and drivetrains that function well in advanced engines and drivetrains. Engine designers have historically been interested in finding workable alternatives to cast iron for more than three quarters of a century. As early as 1923, Audi announced an aluminum alloy engine and became an early leader in applying lightweight alloys to engines [1]. By 2006, the average aluminum content in U.S. automobiles was 319 lb (149 kg), a nearly 24 % increase over the preceding 5 years [2]. Most of this substitution was in the area of structural materials, but lightweight alloys are not ideally suited for tribocomponents such as engine castings, valvetrains, fuel injector plungers, roller followers, and disc brakes. This is mainly because of high contact pressures for the valvetrain components.
Automatic Transmission Lubricants
Authors: Vickerman Richard J. , Tipton Craig
Published: January 2013

This chapter will cover the functions, properties, and composition of automatic transmission fluids (ATFs), along with a brief description and history of original equipment manufacturer (OEM) ATF specifications for passenger cars. The cited works include an eclectic mixture of materials designed to give the reader interested in further study some historic and some more modern information, along with information from different points of view when possible. By no means is this meant to be a comprehensive review; it is only meant to be a small window into the world of transmission lubricant technology.
Surface Analysis and Tribochemistry of Automotive Engine Components
Authors: Morina Ardian , Zhao Hongyuan
Published: January 2013

There are 820 million vehicles in the world today, and with the progressive growth of the automotive sector in developing countries such as Brazil, China, India, etc., the number of vehicles worldwide is predicted to reach 1 billion by 20202. Passenger cars and commercial light vehicles have been estimated1 to account for 20 % of the total CO2 delivered into the atmosphere from hydrocarbon sources in the United States and other developed countries, indicating the level of impact of the automotive sector on the environment. As such, the technological improvement on fuel economy will have a great impact in reducing the CO2 emissions. Reduction of mechanical losses in internal combustion (IC) engines as prime drivers in the automotive industry is an action with immediate effect toward increasing the fuel economy through improving engine efficiency.
Application of ASTM E2691 Standard Practice for Job Productivity Measurement
Authors: Daneshgari Perry , Moore Heather
Published: January 2013

Description

This comprehensive manual describes the user’s experience with ASTM E2691, Standard Practice for Job Productivity Measurement (JPM). This manual includes individual efficiencies of labor and other resources, general contractor vs. subcontractor models, scheduling, planning, jobsite flow, on-site correction to reduce waste, and case studies.

Topics cover:
Resilient and Corrosion-proof Rolling Element Bearings Made from Superelastic Ni-Ti Alloys for Aerospace Mechanism Applications
Authors: DellaCorte Christopher , Noebe Ronald D. , Stanford Malcolm K. , Padula Santo A.
Published: January 2013

Mechanical components (bearings, gears, mechanisms) typically utilize hard materials to minimize wear and attain long life. In such components, heavily loaded contact points (e.g., meshing gear teeth, bearing ball-raceway contacts) experience high contact stresses. The combination of high hardness, heavy loads, and high elastic modulus often leads to damaging contact stress. In addition, mechanical component materials such as tool steel or silicon nitride exhibit limited recoverable strain (typically less than 1 %). These material attributes can lead to Brinell damage (e.g., denting), particularly during transient overload events such as shock impacts that occur during the launching of space vehicles or the landing of aircraft. In this paper, a superelastic alloy, 60NiTi, is considered for rolling element bearing applications. A series of Rockwell and Brinell hardness, compressive strength, fatigue, and tribology tests have been conducted and are reported. The combination of high hardness, moderate elastic modulus, large recoverable strain, low density, and intrinsic corrosion immunity provides a path to the creation of bearings largely impervious to shock load damage. It is anticipated that bearings and components made from alloys with such attributes might alleviate many problems encountered in advanced aerospace applications.
Field Analysis of Arc-Flash Incidents and the Related PPE Protective Performance
Authors: Doan Daniel R. , Hoagland Elihu “Hugh” , Neal Thomas E.
Published: January 2013

This paper will provide a field analysis of the effectiveness of personal protective clothing and equipment and the related worker burn injuries in real-world electric arc-flash incidents, and a review of the ASTM test methods used for determining the arc rating of personal protective clothing and equipment used to protect workers from electric arc-flash hazards. New learning and conclusions relating to the causes of arc-flash burn injuries and personal protective clothing and equipment strategies that can be effective in reducing burn injuries will be discussed.
Chemical Protection Garment Redesign for Military Use by the Laboratory for Engineered Human Protecton Years 2005–2011
Authors: Hultzapple Kristen L. , Hirsch Stephen S. , Venafro John , Frumkin Stephen , Brady Janet , Winterhalter Carole , Proodian Scena
Published: January 2013

The Laboratory for Engineered Human Protection (LEHP) at Philadelphia University investigated materials and developed design concepts to optimize the comfort, sizing, and protection of chemical protective garments. Comfort was defined as ergonomic, biophysical, and tactile. This paper describes the iterative design methods used by LEHP's Garment Team (GT) and the results of those methods. Protective clothing is generally bulky, hot, and uncomfortable, adding to the physical burden a soldier endures. LEHP's goal was to develop a more comfortable uniform for use in environments threatened with chemical warfare. The GT designed and produced six prototype iterations described as Generations 1–6. Each included novel design concepts such as built-in kneepad pockets, strategic body/joint articulation, and a shaped structured hood. A novel hood/mask interface was also developed and refined. Two garment styles were produced. Generations 1 through 4 were a coverall with a fixed hood, while Generations 5 and 6 explored a two-piece jacket/trouser ensemble with two different hood designs—fixed and detachable. The two-piece style featured a mid-torso closure that integrated the two pieces into a system that could be doffed as a one-piece garment. This allows for various size jacket and trouser combinations and provides size flexibility to accommodate the fit for a wide range of body types and sizes. In all prototypes, the carbon layer was a separate component. This may reduce waste by allowing the expired carbon items to be removed, disposed, and replaced independent of the non-contaminated shell garment. This may increase the shell's wear life, where it could continue to function as a duty uniform and be returned to service for chemical protection. LEHP used outside testing facilities for Fluorescent Aerosol Screening (FAST), Contaminated Doffing (CD), and Human Factors (HF) studies. In-house evaluations included Sweating Manikin and Human Factors studies.
A New Test Method to Characterize the Grip Adhesion of Protective Glove Materials
Authors: Gauvin Chantal , Airoldi Alexandre , Proulx-Croteau Simon , Dolez Patricia I. , Lara Jaime
Published: January 2013

Protective gloves can reduce the number and severity of hand injuries but may also impair manual performance such as grip strength. A worker wearing poorly adherent gloves must apply additional muscular effort to retain the handled parts, leading to discomfort, pain, and possibly musculo-skeletal disorders. Glove grip depends on the coefficient of friction (COF) between the glove and handled object surfaces. Knowledge of COF values can be helpful to workers for selecting suitable gloves. However, existing standard test methods for measuring COF are not applicable to gloves. In a previous study, a test method was proposed to evaluate COF of glove materials, using a modified version of the TDM-100 test apparatus initially designed to characterize the cut resistance of protective materials. The test method consists in sliding a flat metal probe on a flat material specimen at a constant speed while applying a load perpendicular to the contact surface. The friction force is measured with a load cell attached to the probe. The friction force versus displacement curve typically presents an initial peak representing the static COF, followed by a plateau representing the dynamic COF. In this study, the effect of the applied load and probe roughness on the COF was characterized with neoprene and nitrile rubber as well as with six different thermoplastic materials. The study demonstrates that both of them affect the measured static and dynamic COFs. A normal load of 10 N, and a probe surface roughness of 1.0 or 2.0 μm gave the most reproducible results and seemed to be the more appropriate to perform testing with different polymer materials. The coefficient of variation of both static and dynamic COFs values obtained was generally lower than 15 %. This test protocol demonstrates to be well adapted to characterize the grip adhesion of glove materials.
Apparatus for Use in Evaluating Protection from Low Pressure Hot Water Jets
Authors: Jalbani S. H. , Ackerman M. Y. , Crown E. M. , van Keulen M. , Song G.
Published: January 2013

Use of hot water has become extensive, especially in bitumen extraction from oil sands and in the production of heavy oil. The hot water is often under pressure and is 80–90°C, which is well above temperatures that result in immediate, potentially severe burn injuries. The ASTM F2701-08 apparatus consists of a funnel through which hot liquid is hand-poured to produce a 10 s exposure. Two 40 mm diameter copper calorimeters, mounted in an insulating sheet are positioned beneath the funnel outlet and are intended to measure the energy transfer through the fabric from the hot liquid. For this research, changes were made to the apparatus and procedures to more closely simulate low pressure hot water streams found in the oil industry and to improve reproducibility. The funnel producing the liquid splash was replaced with a small pipe directly fed by a circulating hot water bath via a small pump, through a hose and valve system, allowing for consistent application of a given quantity of water at a consistent temperature and flow rate. Water temperature, flow rate, and pressure can be altered as desired. A series of fabrics varying systematically on several parameters were tested with the modified equipment. Resulting heat transfer data suggest the system differentiates well among both semi-permeable and impermeable fabrics. Specifications for hot water protection are proposed.
Protective Clothing for Pesticide Operators: The Past, Present, and Proposed Plans
Authors: Shaw Anugrah
Published: January 2013

Pesticide operators have the risk of being exposed to chemicals while handling or spraying pesticides. Use of appropriate Personal Protective Equipment (PPE) is one of the methods for protecting the operators against harmful effects. This paper includes a historical perspective, current scenario, and proposed future plans. The historical perspective includes information on United States pesticide regulations; pesticide safety/stewardship programs; and protective clothing studies and standards. The current scenario provides information on PPE regulation and the challenges it poses in the selection of protective clothing. The section on proposed plans outlines the process for implementation of international performance standards as the basis for providing a risk-based approach to selection of protective clothing. The process could be used as a model to develop recommendations for other types of PPE.
Analyzing Spectral Repeatability of Different Asphalt Pavements Using the OBSI Method in New Jersey and Massachusetts
Authors: Hencken John , Haas Edwin H. , Bennert Thomas
Published: January 2013

For the past two years, the Center for Advanced Infrastructure and Transportation has used the On-Board Sound Intensity Method (OBSI) to examine tire/pavement noise on in-service pavements throughout NJ and the northeast United States. The research initiative originated as a result of the NJ Department of Transportation's (NJDOT's) pavement resource program, which monitors the conditions of NJ roadways and provides engineering-based research about mechanistic pavement design, pavement material characterization, and pavement evaluation. NJDOT is interested in a long-term evaluation of the effects of the age and condition of asphalt pavement on the noise generated at the tire-pavement interface. Of the vast number of asphalt pavement design types found on interstates in NJ, Superpave-based dense graded asphalt (DGA) mixes and open-graded friction course (OGFC) mixes constitute the majority. Throughout the analysis of the OBSI levels measured, patterns that would be beneficial to the industry were illustrated in the one-third octave band profile for each pavement type. This paper provides a brief background of the OBSI method utilized in NJ and MA, an explanation of the analysis utilized to evaluate these pavements, and an explanation of the different spectral signatures attributed to DGA and OGFC pavements.