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Enzyme use has provided boost to the technoeconomics of many industrial processes. In this chapter, we summarize different cellulase-based industrial processes for preparation of paper, pulp, brewing products, and different foods. This review presents a brief chemistry and mechanism of cellulose degradation by the cellulase enzyme. Also, cellulase production abilities of many microbial species have been addressed in this chapter. Cellulase plays a major role in production of good-quality paper and pulp. It’s used to debark the biomass and to remove lignocellulosic part. This enzyme also has application in recycling of used paper by deinking and biobleaching. Cellulase enhances freeness and drainage ability of the fibers without compromising the brightness of the fibers. In brewing industry, cellulase in combination of other enzymes is used to extract the more sugar for better-quality alcohol production. Cellulases have a wide range of potential applications in food and beverage processing, production of fruit and vegetable juices, and improvement of methods for extraction, clarification, and stabilization.

Paper deinking residue (DIR) is a composite waste material generated from paper deinking processes. It is currently underutilized, and its valorization represents both an environmental and economic burden for relative industries. Effective valorization of this low-value waste stream is crucial for paper recycling industries to improve their competitiveness and profitability. Pyrolysis is a promising thermochemical technology to convert biomass/wastes into value-added products. The integration of microwave irradiation as an alternative heating source allows pyrolysis processes to be carried out in a much more efficient and convenient manner. In this chapter, the thermochemical valorization of DIR through pyrolysis and potential applications of its pyrolysis products are demonstrated. Furthermore, the application of microwave-assisted pyrolysis at relatively low temperatures (

Sustainability is essential in future technologies to harmonize with our environment. Cellulose is one of the nature's most abundant natural polymers, the main chemical components of wood and plants. Owing to its own unique material properties, compared with the conventional usage, nanocellulose with a crystalline structure can be considered for various industrial applications. This chapter reviews the fabrication and performance of nanocellulose-based electroactive paper (EAPap) actuators in terms of its three subareas: piezoelectric, ionic, and hybrid EAPap along with their applications. Cellulose is known to have piezoelectric and ion migration effects, and these two effects can be maximized, which result in piezoelectric EAPap and ionic EAPap. To further improve functionality of cellulose, hybrid composites of inorganic functional materials are introduced by incorporating carbon nanotubes, graphene, titanium dioxide, and tin oxide with cellulose. Since cellulose is biocompatible, sustainable, biodegradable, capable of broad chemical modification, and hydrophilic and has high mechanical strength and stiffness, various cellulose-based devices are possible.

Pre­dicted sea level rise due to global warm­ing will ne­ces­si­tate the con­struc­tion of coastal de­fenses to pro­tect the pop­u­la­tions in the vicin­ity of the coasts. Large quan­ti­ties of con­crete will be re­quired with con­sec­u­tive in­creases in green­house emis­sions, hence an in­creas­ing need for al­ter­na­tive to Or­di­nary Port­land Ce­ment (OPC) ce­ments. Fea­si­ble po­ten­tial al­ter­na­tives could be found in al­kali-ac­ti­vated ce­ments , which also in­clude in­dus­trial by-prod­ucts or waste ma­te­ri­als. This pa­per pre­sents a lab­o­ra­tory study of con­crete mixes based on the al­kali-ac­ti­va­tion of an in­dus­trial by-prod­uct, ground gran­u­lated blast fur­nace slag (GG­BFS) and in­cludes an in­dus­trial waste, pa­per slugde ash (PSA) in the al­kali-ac­ti­va­tor mixes. The use of sea­wa­ter as mix­ing and cur­ing wa­ter was also ex­am­ined. The com­pres­sive strength and a num­ber of dura­bil­ity-re­lated prop­er­ties of al­kali-ac­ti­vated mixes in ma­rine en­vi­ron­ment were in­ves­ti­gated and com­pared to OPC sys­tems. The in­cor­po­ra­tion of pa­per sludge ash led to high early strengths, a de­crease in the ef­fec­tive poros­ity of al­kali-ac­ti­vated slag con­cretes and gen­er­ally a re­duced wa­ter ab­sorp­tion, and en­hanced the per­for­mance against chlo­ride ion at­tack in mixes with fresh­wa­ter, as well as the re­sis­tance of the ce­ments in sul­phate at­tack es­pe­cially when mixed with sea­wa­ter. The ad­di­tion of sea­wa­ter in the mixes in­creased the re­sis­tance to sul­phate at­tack and the com­pres­sive strength in al­kali-ac­ti­vated sys­tems, as op­posed to OPC con­cretes in which mix­ing and cur­ing in sea­wa­ter had dele­te­ri­ous ef­fects. The study gives promise for the suit­abil­ity of the tested al­kali-ac­ti­vated con­crete mixes in sea­wa­ter en­vi­ron­ments.

Flexible and wearable electronics have recently attracted increasing attention, because they can open up new possibilities for next-generation portable devices. Cellulose paper serves various purposes in daily life, including in writing, printing, wrapping, and packaging applications. Since paper materials are sustainable, mass produced, inexpensive, biocompatible, recyclable, lightweight, and flexible, the use of paper has recently been extended to flexible electronic applications. In this chapter, we describe cellulose-based flexible paper electronics. Wood-derived cellulose pulp or nanocellulose is composited with conductive nanomaterials such as silver nanowires, carbon nanotubes, and graphene. The as-prepared paper composites are successfully applied as transparent conductive paper, paper antenna, paper sensor, and paper supercapacitor. These paper devices demonstrated both high device performance and flexibility compared with the state-of-the-art polymer-based flexible devices. Our findings provide a promising route to realize green and flexible paper electronics.

The modification of electrodes with nanomaterials is a widespread practice in Electroanalysis because it does not require the use of instrumental components for signal amplification or additional detection techniques, decreasing the cost and facilitating the decentralization of analyses. Different nanostructures, mainly carbon nanotubes, graphene, or metallic nanoparticles, have been used as modifiers on paper-based electrochemical devices. Among others, gold nanoparticles (AuNPs) favor the preconcentration of heavy metals in stripping analysis because of the easy adsorption of the metal in the elementary state on AuNPs. In this experiment, a nanostructured paper-based platform is applied to the electroanalysis of inorganic arsenic in wines by chronoamperometric stripping of the electrodeposited As(0). The electrochemical cell consists of a paper-based carbon working electrode coupled to a screen-printed carbon card. Electrodeposition of AuNPs is performed in a tetrachloroauric(III) acid plating solution.

The paper and packaging industry is an important part of the global economy and plays a critical role in the world economy. Cellulase, a complex enzyme produced by a number of microorganisms, has tremendous potential application in the pulp and paper industry. Cellulase contributes 10% of the worldwide industrial enzyme demand, and there is tremendous potential for cellulase biotechnology in pulp and paper manufacturing to grow steadily commercially, and to give rise to new possibilities. Cellulase, xylanase, laccase, and lipase are the most important enzymes that can be used in the pulp and paper processes. This prospective study aims to enhance the understanding of the most important advanced uses of cellulases for providing benefits to the pulp and paper industry in various areas like increased pulp yield, improved fiber properties, enhanced paper recycling, reduced processing and environmental problems, and energy efficiency.

Company profiles of major pulp and paper chemical suppliers such as Kemira, Akzo Nobel NV, Eka Chemicals AB, Ashland, Inc., BASF, Buckman Laboratories International, Inc., Clariant, and Nalco Chemicals are presented. Major and niche enzyme suppliers—Novozymes, Enzymatic Deinking Technologies, Genencor, AB enzymes, DSM (Netherlands), Diversa (USA), Kao (Japan), and Tritex etc.—are also presented.

The process to be applied to recovered paper to meet the quality requirements of recycled pulp is determined by the grade of the recovered paper and the demands of the final product. Roughly half of the total recovered papers are recycled for the production of case materials, mainly from old corrugated carton (OCC). Besides these brown recovered paper grades, white recovered paper grades, and some high-quality grades, are reused in newsprint, tissue and other graphic paper grades and in whip top layers of packaging papers, so these have to be deinked. Mixed recovered paper grades are used with OCC and for grey solid board layers and thus are not deinked. Deinking lines are more complex than OCC recycling lines. This is because in addition to the re-pulping and contaminant removal process steps, the pulp has to be deinked, and optionally bleached to achieve high brightness. Removing inks that are difficult to deink, like flexo prints and some digital prints, and ‘stickies’ from pressure-sensitive adhesives, are currently the main challenges in the field of deinking. Some examples of typical recycling and deinking lines for different applications – newsprint, fine paper, tissue, market pulp and packaging paper – are presented in this chapter.

A simple method for interlocking glucose oxidase and horseradish peroxidase in a network of cellulose fibers coated with bovine serum albumin (BSA)-exfoliated graphene (biographene) is reported here. The resulting paper reactor is inexpensive and stable. Biographene is expected to function as an electron shuttle, making the reaction between the enzyme and the substrate more efficient, and this hypothesis is examined here. The BSA used to separate the sheets of graphene provides extra carboxylic acid groups and primary amines to help interlock the enzymes and the graphene in between the fibers. The decrease in entropy associated with interlocking the enzymes on a solid support is likely responsible for the increase in enzymatic stability/activity observed. Each cellulose disk contained 5.2 mg of enzyme per gram of paper and 93% of the enzyme is retained after washing for 0.5–2 h. This simple methodology provides a low cost, effective approach for achieving high enzymatic activity and good loadings on a benign, versatile support.

A simple method to verify Beer–Lambert’s law, which is popularly known as Beer’s law, is presented in this chapter. The law is verified using color solutions and a paper device combined with a smartphone as a detector. This experiment does not require a colorimeter or spectrophotometer. While basic information on Beer’s law is given at the beginning of this chapter, the following sections cover topics related to design of the paper microfluidic device, the chemicals and materials required, and the hazards associated with this experiment. The experimental section includes a step-by-step procedure for with detailed steps for device fabrication, solution preparation including extraction of starch from potato, color assay, and data-acquisition methods. Additional notes that may help instructors and students are also highlighted. Assessment questions given at the end of the chapter will be helpful to determine students’ knowledge of the experiment.

[EN] This work deals with the frost resistance of blended cements containing calcined paper sludge (source for metakaolin) as partial Portland cement replacements. Freeze–thaw tests were performed on blended cement mortars containing 0%, 10% and 20% waste paper sludge calcined at 650 °C for 2 h. Cement mortar specimens were exposed to freezing and thawing cycles until the relative dynamic modulus of elasticity fell below 60%. The performance of the cement mortars was assessed from measurements of weight, ultrasonic pulse velocity, compressive strength, mercury intrusion porosimetry and SEM. Failure of the control cement mortar occurred before 40 freeze/thaw cycles, while cement mortar containing 20% calcined paper sludge failed after 100 cycles. After 28 and 62 freezing and thawing cycles, cement blended with 10% and 20% calcined paper sludge exhibited a smaller reduction in compressive strength than the control cement.

[EN]This paper considers calcined paper sludge as an alternative source of metakaolin, an established supplementary cementitious material. Calcination of the sludge generated in the recycling of newsprint paper at 700 °C yields a product with pozzolanic properties. The effects of this recycled metakaolin on the rheology and conduction calorimetry of cement pastes have been studied and compared to the effects of commercial metakaolin. The effects are similar and the results show that calcined paper sludge has the potential to be used as a supplementary cementitious material. This offers a route for utilising this waste material, as an alternative to the increased environmental burden associated with the production of metakaolin from natural kaolinite resources.

This work presents a first approach towards the development of a cost-effective enzymatic paper-based glucose/O2 microfluidic fuel cell in which fluid transport is based on capillary action. A first fuel cell configuration consists of a Y-shaped paper device with the fuel and the oxidant flowing in parallel over carbon paper electrodes modified with bioelectrocatalytic enzymes. The anode consists of a ferrocenium-based polyethyleneimine polymer linked to glucose oxidase (GOx/Fc-C6-LPEI), while the cathode contains a mixture of laccase, anthracene-modified multiwall carbon nanotubes, and tetrabutylammonium bromide-modified Nafion (MWCNTs/laccase/TBAB-Nafion). Subsequently, the Y-shaped configuration is improved to use a single solution containing both, the anolyte and the catholyte. Thus, the electrolytes pHs of the fuel and the oxidant solutions are adapted to an intermediate pH of 5.5. Finally, the fuel cell is run with this single solution obtaining a maximum open circuit of 0.55 ± 0.04 V and a maximum current and power density of 225 ± 17 μA cm−2 and 24 ± 5 μW cm−2, respectively. Hence, a power source closer to a commercial application (similar to conventional lateral flow test strips) is developed and successfully operated. This system can be used to supply the energy required to power microelectronics demanding low power consumption., F. Javier del Campo acknowledges funding from the Spanish Ministry of Economy through the DADDi2 project (TEC2013-48506-C3). Juan Pablo Esquivel would like to thank the support from Marie Curie International Outgoing Fellowship (APPOCS-328144) within the 7th European Community Framework Programme. Shelley D. Minteer and Fabien Giroud would like to thank the National Science Foundation (CHE-1057597) for funding. Neus Sabaté acknowledges funding from the European H2020 Framework Programme (Grant Agreement 648518 - SUPERCELL - ERC 2014 CoG).

Recovered paper collection is increasing due to public interest and support. Four important grades of recovered paper include, corrugated boxes, newsprint, high grades like office papers and mixed papers. Recovered paper processing depends on the grade and product quality specifications. Some of the widely used processes and associated unit operations such as pulping, screening, cleaning using hydrocyclones, flotation deinking, dispersion, washing, and bleaching are described.

Final full-text version of the paper available at: http://www.sciencedirect.com/science/journal/00983004, Measuring and storing magnetometer data recorded photographically is a difficult problem for a geomagnetic observatory. In the Ebre Observatory, to overcome the problem, we have developed a system using modern computing advances which include electronic scanning, storage on CD-ROM media, and image analysis. This paper describes the main processes performed by this system. In particular, it describes the main difficulties found in the process of digitization (intersections, gaps,…) and how they were solved., Authors thank the collaboration of the Juan Salañer Foundation and the C.E.T.S. of the Institut Químic de Sarrià, and recognize the contribution of J. Mustany and R. Gené, the true pioneers of this work.

Waste papers are recycled by deinking. All over the world, the flotation method is the mainstream as the deinking method because of the advantages such as higher pulp yield, less use of water, less area for installation and less total reagent cost. The flotation method is mainly consisted of pulping and flotation processes, the former for ink separation from cellulose, the latter for ink rejecting out from the system. Function to assist the mechanical separation of printing ink from cellulose is required for the deinking agent in the pulping process. In the flotation process, there are three particles, namely, ink, cellulose and bubble, and main four interaction between them in the flotation cell. The following relationship must be held to reject out the ink particles effectively. Vr0

This research work deals with durability aspects of ternary cements containing 79 wt.% ordinary Portland cement (CEM I), 10.5 wt.% coal fly ash and 10.5 wt.% thermally activated paper sludge. Aging tests were performed to study the resistance of the new ternary cement matrixes to the following aggressive exposure conditions: accelerated freeze/thaw cycles, marine environment and Spanish plateau climate conditions. Ternary cements revealed a high resistance to accelerated freeze/thaw cycles. In addition, after 18 months of exposure, they exhibited enhanced performance under marine conditions and similar resistance to Spanish plateau’s climate, compared to ordinary Portland cement.

This chapter examines the final step in a research project: publishing the results. The HCI context for conference papers and journals papers is presented with reference to peer-review and the archival requirement for published research. The major sections of a research paper describing a user study are described: title, abstract, keywords, introduction, method (subsections: participants, apparatus, procedure, design), results and discussion, conclusion, and references. Tips for preparing the manuscript are provided, with a focus on formatting, citations, references, visual aids, and writing for clarity.

Publisher Summary This chapter discusses one issue that has remained pervasive across most existing testing programs considering a switch from paper to computer mode of administration—the need to link scores across the two modes of administration. The issue remains a challenge to the psychometric community because at present there is a lack of clarity about the way to best undertake such a linking and the way to best share the results with score users in operational contexts. The major reason for needing to link computer- and paper-based scores in testing programs is that both modes of testing are likely to occur together, at least for some transition period. However, even if it were the case that paper-and-pencil testing could be immediately phased out when computer-based testing is introduced, scores from the paper version would continue to be reported for some period of time until they are officially no longer accepted. The ideal situation in this context would be one in which the computer- and paper-based scores can be reported on a common reporting scale.

Publisher Summary In his book titled Electrical Papers , Heaviside brought together his main writings on circuit theory and the inductive properties of wires, and his thoughts on electromagnetism. The Electrical Papers offers an advanced exposition, as well as many novel contributions to two basic themes: the theory of electromagnetic field dynamics because of Maxwell and an extension of linear circuit theory to the case of continuous transmission lines. Motivation for the expansion theorem appears to reside in the generalized Ohm's law that operational impedances associate with electrical circuits. In a circuit containing standard resistance only, if the impressed voltage is given, then the current at any time may be calculated by simple division. The main product of this endeavor was a series of three long papers “On operators in physical mathematics” that were intended for publication by the Royal Society. Only the first two were published: the third was turned down in the face of stern objections raised by mathematicians to his unconventional and potentially problematic use of divergent series.

The optical properties of paper are extremely important for many of its uses, especially when paper is used for printing. The important optical properties include reflectance and opacity. It is important to know how processing and variations in the composition of paper will affect the optical properties. A generalized approach to the optical properties of paper allows one to predict the properties of paper to avoid a labor—intensive trial—and—error work approach. Absolute reflectances of paper can be calculated if the reflectance of the MgO standard is known or the photometer is calibrated as such. Absolute reflectance is reported from 0 to 1. The Kubelka—Munk theory is relatively simple in terms of the number of constants involved, works very well for many papers, and is well documented for use by the pulp and paper industry. If the optical properties of each pulp, filler, and dye used in papermaking are known, then the optical properties of a paper made with any combination of the materials can be predicted. If the contrast ratio and reflectivity of a paper are known, the changes in these properties with a change in basis weight can be predicted. If any two variables of R 0 , R 0.89 , R ∞ , known, the third can be determined. Thus, one can calculate R ∞ a single sheet of paper by measuring, R 0.89 and R 0 .

The biotechnological use of xylans and xylanases has grown remarkably. Xylanases have stimulated great interest due to their potential application in several industries. Over the years the number of possible applications of xylanases in the pulp and paper industry has increased steadily, and several applications have been commercialized. Xylanases are being used for prebleaching pulp, modifying fiber, deinking, dedarking, and producing dissolving grade pulp. Apart from its use in the pulp and paper industry, xylanases are also used as food additives to poultry; in wheat flour for improving dough handling and quality of baked products; for the extraction of coffee, plant oils, and starch; in the improvement of nutritional properties of agricultural silage and grain feed; in combination with pectinase and cellulase for clarification of fruit juices; and in the degumming of plant fiber sources such as flax, hemp, jute, and ramie. Use of xylanases could greatly improve the overall economics of processing lignocellulosic materials for the generation of liquid fuels and chemicals. Xylanase and cellulase, together with pectinases, account for 20% of the world enzyme market.

This paper reviews the impact of current and future market and legislative needs on tribological aspects of piston assembly design. Emissions, durability and refinement are highlighted as key issues. The paper commences by discussing the influence of the piston assembly upon hydrocarbon emissions and practical issues associated with crevice volume reduction. The development of theoretical studies of piston ring lubrication is then reviewed briefly, prior to consideration of oil consumption, with particular significance placed upon the very low levels of oil consumption required to satisfy forthcoming particulate emissions legislation for diesel engines. Piston assembly friction accounts for approximately half of total engine friction and is, therefore, a primary target in the quest for lower fuel consumption and the consequential reduction in gaseous emissions. Piston assembly design development to reduce friction is discussed prior to a review of empirical and theoretical studies of piston assembly friction. This leads to a brief discussion of the theoretical analysis of piston dynamic behaviour and skirt form optimisation. Throughout the paper practical problems associated with achieving durability and other performance criteria are highlighted.

The focus of the research is to build a compact, high performance lightstripe rangefinder using a Very Large Scale Integration (VLSI) smart photosensor array. Rangefinding, the measurement of the three-dimensional profile of an object or scene, is a critical component for many robotic applications, and therefore many techniques were developed. Of these, lightstripe rangefinding is one of the most widely used and reliable techniques available. Though practical, the speed of sampling range data by the conventional light stripe technique is severely limited. A conventional light stripe rangefinder operates in a step-and-repeat manner. A stripe source is projected on an object, a video image is acquired, range data is extracted from the image, the stripe is stepped, and the process repeats. Range acquisition is limited by the time needed to grab the video images, increasing linearly with the desired horizontal resolution. During the acquisition of a range image, the objects in the scene being scanned must be stationary. Thus, the long scene sampling time of step-and-repeat rangefinders limits their application. The fast range sensor proposed is based on the modification of this basic lightstripe ranging technique in a manner described by Sato and Kida. This technique does not require a sampling of images at various stripe positions to build a range map. Rather, an entire range image is acquired in parallel while the stripe source is swept continuously across the scene. Total time to acquire the range image data is independent of the range map resolution. The target rangefinding system will acquire 1,000 100 x 100 point range images per second with 0.5 percent range accuracy. It will be compact and rugged enough to be mounted on the end effector of a robot arm to aid in object manipulation and assembly tasks.

Publisher Summary Many problems in economic theory, econometrics, multivariate analysis, and mathematical statistics involve the matrix, which is known as the fundamental bordered matrix of linear estimation because of its role in the Inverse Partitioned Matrix method of linear estimation. It is also called the fundamental matrix of constrained minimization because of its importance in the theory of constrained least-squares. The matrix of linear estimation also appears in the theory of optimization of definite quadratic forms under linear constraints, comparative statics analysis, and restricted maximum likelihood estimation the characterization of estimability. Very often, the matrix is known to be singular. The chapter presents properties of matrix and the Moore–Penrose (MP) inverse of matrix. The MP-inverse is unique and, therefore, has certain theoretical and pedagogical advantages over nonunique generalized inverses.

High efficiency engines that operate at high temperatures (400-1500 °F) mandate new innovative lubrication schemes to achieve success. The most significant technical obstacle is the lubrication and wear at these high temperatures. Liquid lubricants and conventional bearing designs may not be adequate to meet existing goals. Recent understanding of the nature of third body or particulate solid dynamics suggests an alternative to conventional liquid lubrication and solid (coatings) lubrication systems. It is postulated that a layered shearing of compacted triboparticulates generates velocity, pressure, density, and temperature profiles akin to those in the liquid lubricant in a fluid film bearing. Thus triboparticulates can be either injected between the mating surfaces or generated by wear so as to generate the required flows and pressures to lubricate. This paper describes a procedure used to select suitable triboparticulates and experiments that are used to develop a fundamental understanding of their behavior. The results and importance of these experiments to attaining a constitutive equation that can be used to provide design guidelines will be discussed.

Publisher Summary This chapter discusses potential applications of HDTV in the federal government. The use of HDTV in conjunction with high-bandwidth links should enable these changes to occur in a cost-effective manner, one which can be implemented quickly and easily once the broadband networks are in place. Another important application of HDTV in health care will be that of patient care, and health education in the home, which is expected to be another method used to reduce costs, and improve patient care. A display device with the resolution of HDTV should permit household residents to receive information, and training on how to care for a family member recouperating at home, and also, when equipped with a video camera, for physicians to have video visits with the ill person; thus saving the physicians time and also travel discomfort for the patient. A computer connected to monitoring devices could be used in conjunction with the HDTV, and video camera to relay critical patient data to a hospital, or physician, wherever he may be.

The paper presents a further development of studies in zeolite crystallization kinetics carried out earlier in the laboratory of the authors. It was shown that by performing a joint analysis of crystallization curves describing zeolite crystal growth in aluminosilicate gels in the process of their hydrothermal crystallization and of data on size distribution zeolite crystals in the final products of gel crystallization in combination with their pretreatment at different temperatures before subsequent isothermal crystallization, one can attack the problem of studying temperature dependences of zeolite nucleation rate in the crystallizing gels.

The effect of journal misalignment on the performance of a big-end connecting-rod is analysed in this paper. The misalignment considered varies in magnitude and direction during all the cycle up to contact between the shaft and the bearing. The numerical procedure incorporates misalignment velocities. The technique used for bearing characteristics evaluation (minimum film thickness, friction torque, axial flow) is an extension of the mobility method of BOOKER.

Applying EHL theory, the paper derives the mathematical model for analysis of lubricating of cylinder sleeve and piston ring, and composes a general CAD program for computation of the thickness of lubricant film, by which anlyses can be made to the lubricating state of cylinder sleeve and piston ring for engines of various models with different operating mode. Tests of specific point on bench in specific conditions show that the computing method is feasible.

A set of sapphire windows have been inserted in the cylinder liner of a Petter AVI diesel engine. This has enabled the temperatures of the piston ring and piston land surfaces to be measured at various points in the cycle of a firing engine using an infrared emission microscope attached to a storage oscilloscope. In this paper the method is described and some results obtained at mid-stroke and top dead centre are presented. These are compared to previous measurements of the bulk temperature of piston rings taken by other workers.

In this paper, the dynamic performance of the Ruston and Homsby VEB diesel engine connecting-rod bearing is analyzed. The effect of cavitation is considered by using a cavitation algorithm, which mimics JFO boundary conditions. The effect of mass inertia is accounted for by solving coupled nonlinear equations of motion using a fourth order Runge-Kulta method. The performance is predicted for a bearing with a circular profile and two noncircular profiles, viz, worn circular and elliptical. For the circular bearing the results are compared with various published results and the predictions for the non-circular bearings are compared to those with a circular profile.

Fibers such as fabric and bristles can be readily fabricated into a variety of configurations that are compliant and responsive to high-speed or lightly loaded systems. These configurations can be linear, circular, or contoured linear or circular. In this paper visualization and characterization of the complex flow fields in simulated linear bristle configurations as applied to brush seals (bearings) are explored. The full-field flow tracking (FFFT) method is used to visualize the flow field and bristle dynamics, which were nonintrusively determined and graphically reconstructed. Visualization of the flow field revealed regions that are characteristically river, jetting, vortical, cross, and edge flows and exist upstream, downstream, or within the brush. Such flows are caused by variations in fiber packing and stiffness that are both spatial and temporal and strongly influence leakage, stability, and load capacity. Potential applications of brush seals are described herein, and in the appendix a brush seal system design procedure is provided that compares favorably with brush seal leakage results.

This paper presents experimental measurements from laboratory dynamometers of the dependence of the life of automotive timing belts on belt torque and total tension in the transmission of power between two crankshaft sized (19 tooth) pulleys, each with an angle of wrap of 180°. Failure observations of tooth root cracking and of worn belt covers are also presented. Contact loads between belt and pulley teeth have been calculated and it is found that in the conditions of the present experiments tooth load at exit from the driven pulley is the critical load controlling life by tooth root cracking: assuming that this remains the critical load, predictions are made of the effect on life of changing belt tension, pulley size and angle of wrap.

The purpose of this paper is to reveal the relation between flexibility and clearance of oil film by a co-rotating bearing (bush is rotating together with shaft in the same direction and rotation rate), which can be used for sharing load equally in planetary transmission of vehicle. The authors have adopted a theoretical approach of infinite width bearing and explained the characteristics of oil film for co-rotating bearing. Using the numerical calculation to solve the non-linear equation, the authors have gotten the results on finite width co-rotating bearing. By experiments, the relations between flexibility and clearance of oil film for co-rotating bearing are presented by charts in different clearance, rotation rate and load. A good consistency of the results between experimental and numerical calculation result is gotten.

This paper gives the General Motors (GM) perspective in vehicle tribology. Tribology plays an important role in vehicle durability, reliability, and fuel efficiency. While several areas in the vehicle are included, major emphasis is given to engine tribology. Piston skirt, piston rings, crankshaft and its bearings, and the valve train are identified as the most critical reciprocating engine components for tribological investigation. In addition to discussing these, engine friction, engine lubricants, clutches and brakes, and sheet metal forming are briefly covered. In each case the tribological state-of-the-art, as applied in design, is identified. GM's analytical and experimental capabilities are discussed, and areas where more work is needed are identified.

The purpose of this paper is to clarify a universal method to calculate the speed ratio and the power transmission efficiency of rolling contact continuously variable transmissions with planetary cones (differential type CVT). The authors present a new method in which the instantaneous center of rotation and the speed and torque efficiencies were effectively used. This method can be used to derive the equations for calculating the ratio and the efficiency of any types of CVT's and gear drives with complex mechanism. Using the equations obtained in the present investigation, numerical calculations were conducted in the case of a differential CVT with planetary cones. The calculated results agreed well with the experimental ones when the oil churning and bearing losses were taken into account.

Previous attempts to predict the film thickness in synovial joints have been hindered by inadequate modelling of the joint prior to analysis. It is well known that elastohydrodynamic action between the low elastic modulus (soft) layers of cartilage plays a major role in the effective lubrication of synovial joints, yet it is only recently that the finite thickness of the layers has been incorporated into the analysis. Furthermore, analysis of the lubrication of such layers has been restricted to nominal line contacts, whereas the hip joint presents an essentially point or circular contact problem. In this paper we present a point contact, elastohydrodynamic lubrication analysis for low elastic modulus layers of bearing material mounted on rigid substrates. The solutions indicate the magnitude of the ‘side-leakage’ correction factors which have to be introduced in any complete lubrication analysis of realistic models of synovial joints.

The problem treated in this paper is of interest for the analysis of coatings that consist of one or more elastic or viscoelastic layers bonded together and to a substrate. Each coating-cum-substrate (“cylinder”) is modeled as a twodimensional elastic or viscoelastic half-space consisting of layers with arbitrary thickness whose material constants differ. The cylinders are in rolling contact; friction is modeled by Coulomb's law; partial slip in the contact area is allowed. The analysis is linear. The problem is attacked by an influence function method (Green's functions). The influence functions are the displacement-stress field in the half-space due to a normal and a shearing standard loading moving over the (visco)elastic half-space with rolling velocity. They are determined by means of a complex Fourier transform, which is inverted by a method that warrants a prescribed accuracy. The two influence functions are each convoluted by a weight function. The weight functions are found with the aid of algorithms which have proved their utility in Kalker's programs CONTACT and LAAGROL, and which have been established rigorously by Kalker (1988) in the elastic case. Apart from frictionless and fully sliding contact, loadings due to partial slip in the contact may be determined; the displacement-stress field both on and inside the half-space may be computed. Up to now, an implementation has been made in which the cylinders consist of a single elastic layer bonded to a rigid base, and where only the surface load and displacement distributions are calculated (LAAGROL). The determination of the surface elastic field due to finite creepage resulting in partial slip in the contact area is the main thrust of this program. The method presented is akin to that of Bentall-Johnson (1968), but automated, modernised, and extended.

The generation of ultra-high molecular weight polyethylene (UHMWPE) wear particles from bearing surfaces in patients remains a major concern with long term implants. Both the volume and morphology of the wear debris are important factors in determining the response of the body to particles and subsequent effects on secure fixation. Uni-directional tri-pin on disc tests of UHMWPE sliding on a smooth stainless steel counterface have shown a low underlying wear rate with periodic transient increases in wear rate of the UHMWPE pins. Monitoring of the topography of the wear pins revealed the formation of ridges in the surface parallel to the direction of travel. The periodic increases in wear rate corresponded to the loss of UHMWPE from the tops of the ridges subjected to the largest deformations. Birefringent micrographs of sections of UHMWPE pins cut perpendicular to the surface showed residual sub-surface shear strains under these ridges. The sub-surface strains were much higher in the sections cut parallel to the direction of sliding than in those perpendicular to the sliding direction. Wear debris collected from the fluid consisted of two types, the first having a large aspect ratio and the second being more granular. Wear debris was also attached to the trailing edge of the pin in the form of an extruded ribbon of few microns thick. The observations indicated that a sub-surface failure mechanism operating on a macroscopic scale caused the incremental increases in the wear rate. The intermittent higher wear rates were associated with the removal of UHMWPE that had been subjected to the highest deformations. After the removal of the highly strained material the wear rate returned once more to the underlying lower wear rate assocaited with a particular level of counterface asperity interactions with the UHMWPE.

An experimental study of particulate metallic contaminant deformation and of the effect on surface indentation in high speed ball bearing is presented. Particles are initially spherical and are composed of M50 high carbon steel powder. A high speed rig with a controled level of oil contamination was built. Information concerning initial and final particle dimensions and indent shape on the bearing raceway was given by microscopic investigation. An optical measurement system is also used to describe the indent topography. Investigation shows that a hard spherical metallic particle is uniformly flattened as it passes through the EHD contact.

A mass-conserving simulation algorithm for cavitating hydrodynamic lubrication has been described elsewhere. The algorithm, which is particularly well adapted to finite element implementation, is outlined qualitatively and demonstrated quantitatively through real and ideal engine bearing applications studied previously by others. Present simulation results and previous data agree reasonably closely for these applications, providing a limited validation of the present algorithm and demonstrating the importance of mass conservation in engine bearing design analysis.

The modern concept of a car wheel bearing is a complete unit that is ready to use, greased and sealed for life. Thus today the lubricant and the seal form an integral part of the bearing. With ongoing improvement in bearing internal geometry and materials, the performance of the seal can even replace rolling contact fatigue as the limiting factor for bearing service life. At the same time, demands for reliability and long, service-free running periods are continuously increasing. Systematic efforts during recent years have resulted in improved seal designs and have provide deeper insight into their functioning and the tribology effects involved. Seals for grease lubricated bearings are defined as active hydrodynamic engineering elements, with a preferential outward pumping effect to prevent penetration of foreign matter into a bearing unit. Seal life is thus governed by the existence of preferential pumping effects. When these have vanished, the seal transforms from an active into a passive engineering element. Bearing life from then depends on environmental factors only. Several mechanisms were identified which influence these effects negatively and thus restrict seal life: of these ageing of the seal lip material and counterface abrasive wear are described. Limiting factors were found and incorporated in a seal life model.

Experimental investigations on connecting-rod bearings in operating engines required the use of a mechanical scissor linkage to support the wires carrying the electronic signals. In many applications, one end of the linkage is attached to the big-end bearing cap by a yoke, the other end being fixed to the engine frame. The mass and inertia of the linkage modify the load acting to the bearing and change the bearing characteristics. The effect of the mechanical linkage is estimated by carrying out both rigid and elastic bearing calculations with and without a contribution from the linkage to the connecting-rod load. The loads arising from the yoke and links on the connecting-rod were calculated as a function of crankangle for different crankshaft speeds. The calculations showed that the linkage and yoke increase the inertial part of the load diagramm by about 10% and modify the orbit of the bearing center at small eccentricity ratios.

Methods of calculating oil flow in connecting rod big end bearings are discussed and a numerical example typical of engine practice is presented. The commonly used oil feed arrangement for connecting rod bearings, consisting of a single hole emerging from the crank pin, results in small flows and the bearing oil film may be depleted. It is therefore necessary to consider a rigorous ‘oil film history’ model where the transportation and availability of oil in the bearing clearance is allowed for. Cycle-averaged oil flow results for over 150 bearing cases are summarized in design chart and equation form. The design charts are of two types, one relating the flow from the rigorous oil film history method with the oil flows based on rapid methods. The other type considers directly the many engine and bearing parameters involved thus making this technique suitable for general use. Also included are sensitivity charts showing the effect on oil flow of changes in particular parameters.

Empirically-derived correlations of dimensionless flow and load are presented as a direct means of predicting cycle-averaged feed pressure and hydrodynamic flows in ungrooved connectingrod bearings which are pressure-lubricated through a crankpin feed hole. The correlations allow quick estimation of flow sensitivity to small engine/bearing dimensional variations, as well as provide a simple relation that indicates when feed pressure flow can be a good indicator of actual flow.