bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of Surface Forces and Adhesion
Authors: van Spengen W. Merlijn , Fischer H.R.
Published: December 2018

This article first describes surface forces, and the methods of measuring them, followed by a discussion on adhesion. It discusses the instrumental requirements and techniques, including Atomic Force Microscopy (AFM), used for the measurement of surface forces. Measurements of surface roughness, with AFM, can provide a precise picture of surface roughness and can be used as input for contact mechanics computer models. The article also describes microscale adhesion and adhesion measurement methods using microelectromechanical systems technologies. It reviews certain considerations used for the measurement of adhesion, such as fundamental adhesion measurements, history dependence and sample preparation, and practical adhesion measurements. The article describes various arrangements that can be employed in adhesion tests.
Wear Measurement
Authors: Qian Linmao , Chen Lei , Jiang Liang
Published: December 2018

This article describes the determination of wear loss by measuring either mass change or dimensional change of lubricants and materials. It discusses the principles, advantages and disadvantages of mass loss measures and dimensional measures of wear. The article details wear measurement at the nanoscale, such as atomic force microscopy (AFM) measurement and scanning electron microscopy measurement. It reviews the techniques of wear measurement at the atomic level, namely, transmission electron microscopy (TEM) measurement and AFM combined with TEM measurement.
Wear Maps
Authors: Lim S.C.
Published: December 2018

This article describes the usefulness of wear maps and explains how to construct a proper wear map from scratch and effectively employ such a map to make important design decisions for a particular tribological situation. It discusses three categories of wear-data presentation: numeric data, topographic data, and multidimensional graphical data. The article provides a brief description of the development of different groups of wear maps. It also summarizes the essential components of a wear map.
Basic Theory of Solid Friction
Authors: van der Heide Emile , Schipper Dirk Jan
Published: December 2018

This article begins with the basic concept of friction and with the general approaches that can be used to control or minimize it. It focuses on the factors influencing rolling friction: surface topography, composition, subsurface microstructure, and lubrication conditions. The article reviews the microscopic mechanisms generating friction. It concludes by discussing the three components of rolling friction: microslip at the interface, anelastic hyteresis losses, and surface roughness.
Tribological Testing and Presentation of Data
Authors: Czichos Horst , Woydt Mathias
Published: December 2018

The influence of friction and wear on the function and structure of tribological systems is determined by various types of tribological tests. This article introduces the general categories of tribological testing and describes the basic objectives of testing. It reviews the results of tribological tests, where the system-dependent characteristics of friction and wear data can be expressed in different forms, such as tribographs, transition diagrams, and tribomaps. A summary of various methods of surface analysis is presented in a table. The article discusses the relationship between wear and reliability in terms of exponential distribution, Weibull distribution, and gamma distribution. It concludes with information on the effects of interaction on failure probability.
Thermal Spray Coatings for Friction and Wear Control
Authors: Bobzin Kirsten , Öte Mehmet , Königstein Tim , Zhao Lidong , Wietheger Wolfgang
Published: December 2018

This article describes the technology of thermal spraying with regard to tribological applications. It introduces the basics of tribology and presents the fundamentals of thermal spraying and the relevant process variants and suitable materials. Specific application areas are described regarding the different forms of elementary movement in the corresponding tribological system. The article provides an overview of thermal spray coatings and possible uses for friction and wear control, besides operating as corrosion protection and a thermal barrier. The article provides examples that illustrate how tribological performance can be improved.
Wear and Galling Resistance of Borided (Boronized) Metal Surfaces
Authors: Zimmerman Craig
Published: December 2018

Boronizing is a case hardening process for metals to improve the wear life and galling resistance of metal surfaces. Boronizing can be carried out using several techniques. This article discusses the powder pack cementation process for carrying out boronizing. It describes the structures of boride layers in ferrous materials and boride-layer structures in nickel-base superalloys. The primary reason for boriding metals is to increase wear resistance against abrasion and erosion. The article reviews the wear resistance and coefficient of friction of boride layers, as well as galling resistance of borided surfaces. It concludes with a discussion on boronizing plus physical vapor deposition (PVD) overlay coating.
Lubrication and Wear in Drawing Operations
Authors: Ngaile Gracious , Lowrie James
Published: December 2018

Drawing is a process by which a workpiece is pulled against a die to produce a wire, bar, or tube with smaller cross sectional area compared with the initial stock. This article discusses the variables that affect the drawing process and the parameters that influence friction, lubrication, and wear. These parameters include process, lubricant, workpiece, and tooling. The article provides information on dry and wet lubrication in wire drawing. The dry lubrication refers to use of solid lubricants while wet lubrication refers to the practice of providing a liquid lubricant to the workpiece-die interface. The article describes the most common types and causes of die wear: abrasive wear, adhesive wear, surface fatigue wear, thermal fatigue wear, and catastrophic failure. It concludes with a discussion on the surface treatment and texturing that are used to reduce die wear in drawing operations.
Friction, Lubrication, and Wear of Internal Combustion Engine Parts
Authors: Wong Victor W. , Tung Simon C.
Published: December 2018

This article focuses on friction, lubrication, and wear of internal combustion engine parts, improvements in which provide important gains in energy efficiency, performance, and longevity of the internal combustion (IC) engine systems. It discusses the types, component materials, and Friction and Wear Control of IC engine. The article explains the process of friction reduction by surface textures or coatings. It provides information on surface hardening of iron and steel, which is commonly employed for engine and powertrain components such as crankshafts, cams, and cylinder liners. The article also discusses advanced surface engineering technologies, such as diamondlike carbon coatings and surface texture technology. Information on thermal-spray methods that have led to improvements in engine components is also provided. The article describes IC engine-components wear, namely, piston assembly wear, valvetrain wear, cylinder-bore wear, and engine bearing wear. It concludes with information on inlet valve and seat wear of IC engine.
Solid Lubricants
Authors: Dugger Michael T.
Published: December 2018

Solid lubricants consist of materials placed at the interface between moving bodies to mitigate friction and wear. This article begins with a historical overview of solid lubricants and discuses the characteristics and fundamental aspects of solid lubricants. It describes the material categories of solid lubricant coatings, including graphite, graphite fluoride, transition metal dichalcogenides, diamond-like-carbon, polymeric materials, and metallic films. The article presents a description of deposition methods from the simplest processes involving burnishing and impingement in open air to modern vacuum-based methods for solid lubricants. It concludes with a discussion on metrics that can be used to qualify solid lubricants in high-consequence applications.
Cyclic Stress-Strain Response and Microstructure
Authors: Christ Hans-Jürgen
Published: December 2018

This article discusses the microstructural processes that take place during plastic deformation and presents a plain phenomenological and general description of the cyclic stress-strain (CSS) response. It emphasizes the microstructural aspects of cyclic loading on single-phase materials tested in initially soft, dislocation-poor conditions resulting from a prior heat treatment. The article discusses deformation-induced phase transformations in austenitic stainless steels and commercial age-hardened aluminum alloys. It describes the interaction of dislocations and the strengthening of second-phase particles. The article also provides a description of the framework used to model the CSS response on a physical basis.
Fundamentals of Modern Fatigue Analysis for Design
Authors: Mitchell M.R.
Published: December 2018

Fatigue crack initiation is an important aspect of materials performance in design. This article summarizes some fundamental concepts and procedures for the fatigue life prediction of relatively homogeneous, wrought metals when a major portion of total life is exhausted in crack initiation. It presents an overview of the strain-based, as opposed to stress-based, criterion of material behavior and fatigue analysis. The article describes the cyclic stress-strain behavior of metals to illustrate the inadequacy of the monotonic or tensile stress-strain curve in accounting for material instabilities caused by cyclic deformations. It discusses the effect of mean stress on fatigue life and presents the analysis of cumulative fatigue damage. The article concludes with examples of application techniques for fatigue life prediction.
Estimating Fatigue Life
Authors: Dowling Norman E.
Published: December 2018

This article discusses two major approaches in estimating fatigue life from the viewpoint of their use as engineering methods. These include the stress-based (S-N curve) approach and strain-based approach. The stress-based and strain-based approaches are compared, with some comments on their manner of use and limitations. The use of the Palmgren-Miner rule for life prediction for variable amplitude loading is also discussed.
An Introduction to Fracture Mechanics
Authors: Antolovich Stephen D. , Antolovich Bruce F.
Published: December 2018

The concepts of fracture mechanics are basic ideas for developing the methods of predicting the load-carrying capabilities of structures and components containing cracks. This article provides an introduction to the methodology for computing the onset of fracture and describes plane strain fracture toughness, denoted as KIC. It presents formulas for the stress-intensity parameter as a function of crack size, crack shape, applied stress (or load), and geometry of load application.
Fracture Resistance of Structural Alloys
Authors: Ravichandran K.S. , Vasudevan A.K.
Published: December 2018

Fracture mechanics is a multidisciplinary engineering topic that has foundations in both mechanics and materials science. This article summarizes the microstructural aspect of fracture resistance in structural materials. It provides a discussion on basic fracture principles and schematically illustrates the mechanism of crack propagation. The article describes the fracture resistance of high-strength steels, aluminum alloys, titanium alloys, and composites such as brittle matrix-ductile phase composites and metal-matrix composites. It also lists the effects of microstructural variables on fracture toughness of steels, aluminum alloys, and titanium alloys.
Fatigue and Fracture Properties of Aluminum Alloy Castings
Authors: Reinhart Theodore L.
Published: December 2018

This article reviews the fatigue and fracture properties of aluminum alloy castings, specifically alloys A356 and A357/D357 (all-T6) and alloy A201-T7, from the perspective of both design and manufacturing considerations. In addition, it provides an overview of the roles played by microstructure, manufacturing processes, test conditions, and casting design in determining the fatigue and fracture properties of aluminum casting alloys.
Fatigue Properties of Copper Alloys
Authors: Crane Jack , Ratka John O. , Breedis John F.
Published: December 2018

Copper alloys are classified by the International Unified Numbering System designations to identify alloy groups by major alloying element. This article presents the designations and compositions of various copper alloys, such as brasses, nickel silvers, bronzes, beryllium coppers, and spinodal alloys. It discusses the fatigue testing of the copper alloys and tabulates the tensile and fatigue strengths of the copper alloys. The article schematically illustrates S-N curves for the solid-solution (non-aging) strengthened alloys. It concludes with a discussion on the role of microstructure in the fatigue performance of beryllium copper alloys.
Mechanism Dynamics and Simulation
Authors: Crosheck James E.
Published: December 2018

This article presents an overview of the use of mechanism analysis (kinematics and dynamics) and simulation. It provides indications of the directions in which mechanism simulation is growing and how it is integrated in the evolving computer aided design and computer aided engineering (CAD/CAE) fields. Mechanism simulation is best used as part of a concurrent CAD/CAE approach to design. The article discusses the state, evolution, and direction of application for these techniques in a variety of fields.
Value Analysis in Materials Selection and Design
Authors: Fowler Theodore C.
Published: December 2018

Value analysis (VA) is a team problem-solving process to improve the value of a product from the viewpoint of a user. This article presents a comparison between VA and total quality management in materials selection and design. It discusses the key attributes, concepts, and activities of the VA. The application of value engineering in U.S. government contracts and the construction industry is reviewed. The article describes the eight phases of the VA process: preparation, information, analysis, creation, synthesis, development, presentation and report, and implementation and follow-up. It presents case studies that illustrate the materials-related aspects of the VA process.
Effects of Composition, Processing, and Structure on Properties of Ceramics and Glasses
Authors: Greenhut Victor A.
Published: December 2018

This article provides a discussion on various types of glasses: traditional glasses, specialty glasses, and glass ceramics. It provides information on glazes and enamels and reviews the broad classes of ceramic materials. These include whitewares, structural clay products, technical ceramics, refractories, structural ceramics, engineering ceramics, and electronic and magnetic ceramics. General processing variables that can affect structure and compositional homogeneity are discussed. Traditional ceramics that include both oxide and nonoxide ceramics are also reviewed. The article concludes with several examples of engineering ceramics.
Carbon Matrices
Authors: Pruett James Gary
Published: December 2018

This article describes the various pure forms of carbon matrices and the corresponding methods used to create them or incorporate them into a matrix of a composite. These forms include graphite, diamond, fullerenes, and nanotubes. The article discusses the three types of liquid precursors, namely, thermoplastic, thermosetting, and evaporative or solvent carriers. It provides a description of the advantages and limitations of various methods involved in chemical vapor infiltration. The article concludes with a discussion on matrix contribution to composite properties.
Out-of-Plane Analysis
Authors: Goering Jonathan
Published: December 2018

This article discusses the methods of analyzing the directional dependence of the mechanical properties of composites, especially those perpendicular to the major plane of the laminate. It provides a description of the common indirect load cases and direct out-of-plane load cases. The article concludes with a discussion on composite materials that are reinforced in the z-direction (also known as three-dimensional, or 3-D composites).
Engineering Mechanics and Analysis of Metal-Matrix Composites
Authors: Majumdar Bhaskar S.
Published: December 2018

The goal of micromechanics and analysis is to use the predictive methodology to develop tailored composites and also to make accurate predictions of their performance in service. This article reviews results derived from micromechanics analyses, based on finite-element method of unidirectional fiber reinforced metal matrix composites (MMCs). It discusses the elastic deformation and elastic-plastic deformation analysis of discontinuously reinforced MMCs. The article provides an overview of analysis of strength, fatigue, and fracture toughness for macromechanics fiber-reinforced and discontinuous reinforced composites.
Composite Tooling
Authors: Dorworth Louis C.
Published: December 2018

Composite tooling is the making of tools from composite materials. This article focuses on wet lay-up methods and techniques that are used to fabricate prepreg tooling. It discusses the advantages and disadvantages of composite tools. The article describes the process considerations for composite tool design, such as master model or pattern design selection, fiber and fabric selection, resins, and surface coat and ply. Various tool laminate construction techniques, such as curing and demolding, and cutting and trimming, are reviewed. The article also describes the substructure design for the construction of tool laminates.
Fiber Placement
Authors: Evans Don O.
Published: December 2018

This article schematically illustrates a fiber placement system and provides information on the applications of fiber placement. It discusses materials and design considerations for fiber placement. The article provides information on techniques that can be used to eliminate areas of missing tows.
Resin Transfer Molding and Structural Reaction Injection Molding
Authors: Rudd C.D.
Published: December 2018

Resin transfer molding and structural reaction injection molding belong to a family, sometimes denoted as liquid composite molding. This article provides information on the characteristics and automotive and aerospace applications of liquid composite molding. It reviews techniques that use hard tooling and positive (superatmospheric) pressures to produce structures. The techniques include vacuum-assisted resin injection, vacuum infusion, resin-film infusion, and injection-compression molding. The article provides an overview of the materials that are commonly used together with some of processing characteristics that are important to processing speed and part quality. It concludes with a discussion on design guidelines for the liquid composite molding.
Filament Winding
Authors: Peters S.T. , McLarty J. Lowrie
Published: December 2018

Filament winding is a process for fabricating a composite structure in which continuous reinforcements, either previously impregnated with a matrix material or impregnated during winding, is placed over a rotating form or mandrel in a prescribed way to meet certain stress conditions. This article describes the advancements in filament winding and lists the advantages and disadvantages of filament winding. It discusses the effects of fiber tension in filament winding and the selection of fibers, resins, and materials for filament winding. The article emphasizes the three basic filament-winding patterns, such as helical, polar, and hoop. It presents information on the applications of filament winding, including rocket motors, natural gas vehicle (NGV) tanks, and sporting goods. The article presents recommendations for the basic design guidelines for filament-winding design/manufacturing process and concludes with a discussion on fabrication recommendations.
Tube Rolling
Authors: Basso Robert J. , Roy Paul A.
Published: December 2018

This article describes processes and equipment that are used to produce composite tubular parts. The processes include sheeting, pattern cutting, tube rolling, shrink tape debulking, and finishing. The article provides a discussion on materials that are most suitable for tube rolling: preimpregnated materials and unidirectional tapes. The article also discusses wrapping techniques of cylindrical and tapered tubes, such as convolute and spiral wrapping.
Introduction to Product Reliability, Maintainability, and Repair
Authors: Hoke Michael J. , Heslehurst Rikard B.
Published: December 2018

This article provides a summary of the concepts discussed in the articles under the Section “Product Reliability, Maintainability, and Repair” in ASM Handbook, Volume 21: Composites. The Section covers a range of topics that include the general issues for reliability, maintenance, and repair of composite structures. Specific structural applications, including marine, infrastructure, and aircraft related issues, are discussed. Operators of equipment employing composite structures in primary load applications must understand the issues with respect to maintenance and repair action. The Section also provides information on these requirements.
Bonded Repair of Metal Structures Using Composites
Authors: Chester Richard J. , Mazza James J.
Published: December 2018

Composite bonded repair technology is based on the use of advanced composite repairs or reinforcements that are adhesively bonded to a damaged structure. This article discusses the key steps that are normally encountered in the design, certification, and application of an adhesively bonded repair. Some examples of successful repairs to military aircraft are also discussed.
Maintainability Issues
Authors: Cole William F. , Forte Mark S. , Heslehurst Rikard B.
Published: December 2018

Maintainability is a function of the durability, damage tolerance, and repairability of a structure. This article discusses the configurations of composite structures, such as sandwich, stiffened-skin, and monolithic structures, used in commercial aircraft composites. It describes the considerations for maintainability of the composite structures during the conceptual design phase. Sources of the defects and damage, such as manufacturing defects and in-service defects, are reviewed. The article describes the nondestructive inspection methods that are used in the repair of composite structures to locate damage, characterize the extent of damage, and ensure post-repair quality. It lists suggestions that can be used as design guidelines for adhesive bonding, general composite structure, sandwich structure, material selection, and lightning-strike protection. The article also provides the basic considerations for personnel, facilities, and equipment during maintenance.
Fractography
Authors: Stumpff Patricia L.
Published: December 2018

This article illustrates typical fractographic features for a number of different composite materials. It describes the differences in fracture characteristics due to different loading, material processing, and environmental conditions. The article presents fractographic data obtained from epoxy matrix materials. Minimal fractographic data from other brittle thermoset resin systems are also presented. The article discusses the interlaminar fracture of composites with ductile thermoplastic matrices. It also provides information on the translaminar fracture features of the composite materials.
Modeling of Creep
Authors: Tin Sammy
Published: December 2018

This article, to develop an understanding of the underlying mechanisms governing deformation at elevated temperatures, discusses the phenomenological effects resulting from temperature-induced thermodynamic and kinetic changes. It describes the deformation behavior of engineering materials using expressions known as constitutive equations that relate the dependence of stress, temperature, and microstructure on deformation. The article reviews the characteristics of creep deformation and mechanisms of creep, such as power-law creep, low temperature creep, power-law breakdown, diffusional creep, twinning during creep deformation, and deformation mechanism maps. It discusses the creep-strengthening mechanisms for most structural engineering components. The article provides a description of the microstructural modeling of creep in engineering alloys.
Application of Neural-Network Models
Authors: Sha Wei , Malinov Savko
Published: December 2018

Neural-network (NN) modeling is most suitable for simulations of correlations that are hard to describe or cannot be accurately predicted by physical models. This article describes the principles and procedures of NN modeling. It discusses the use of NN modeling in general organization of software and graphical user interfaces. The article also provides information on the ways to improve and upgrade the NN models.
Simulation of Microstructure and Texture Evolution in Aluminum Sheet
Authors: Engler Olaf , Karhausen Kai , Hirsch Jürgen
Published: December 2018

This article explores the potential of through-process simulations of the development of microstructure, texture, and resulting properties during the thermomechanical processing of Al-Mn-Mg alloys, starting from the as-cast ingot to final-gage sheet. It provides an introduction of the thermomechanical production of aluminum sheet and, in particular, highlights the main effects governing the evolution of microstructure and texture. The simulation tools used to model the evolution of microchemistry, microstructure, and texture upon deformation and recrystallization of aluminum alloys are described. The article discusses the recrystallization behavior of alloy AA 3104 during the interstand times in between two consecutive hot rolling passes with the help of combined microstructure models.
Localization Parameter for the Prediction of Interface Structures and Reactions
Authors: Lojkowski Witold , Fecht Hans J.
Published: December 2018

This article summarizes a physical model of an interface structure and shows how the model helps in optimizing atomistic modeling studies. It presents the orientation relationship of the interface structure to define the mutual crystallographic position of adjacent crystals. The article describes the model-informed atomistic modeling of the interface structures for interpolating the results of atomistic modeling to predict the properties of interfaces. Theories to predict low-energy orientation relationships are described. The article discusses the use of the localization parameter, such as shear modulus, bonding energy, and transformations, for prediction of interface structures. It provides information on the application of the atomistic modeling of interface structure to predict interface reaction mechanisms.
Neural-Network Modeling
Authors: Bhadeshia H.K.D.H. , Stone H.J.
Published: December 2018

Neural networks permit the discovery of fundamental relationships and quantitative structure within vast arrays of ill-understood data. This article provides an overview of neural network modeling method, describing its overfitting nature. It discusses the use of neural networks in modeling noise and uncertainties in conducting experiments. The article also presents examples of the application of neural-network modeling to the behavior of metals.
Modeling Fatigue Crack Growth
Authors: Rosenberger Andrew H.
Published: December 2018

Understanding fatigue crack growth is critical for the safe operation of many structural components. This article reviews the standard fracture mechanics and methods to determine the crack growth rate for a material and loading condition experimentally. It also addresses the two most important aspects of crack-growth modeling: loading environment and crack geometry.
Diffusivity and Mobility Data
Authors: Campbell Carelyn E.
Published: December 2018

Diffusion is the process by which molecules, atoms, ions, point defects, or other particle types migrate from a region of higher concentration to one of lower concentration. This article focuses on the diffusivity data and modeling of lattice diffusion in solid-state materials, presenting their diffusion equations. It discusses different methods for evaluating the diffusivity of a material, including the measurement of diffusion coefficients, composition profiles, and layer growth widths. The article reviews the various types of direct and indirect diffusion experiments to extract tracer, intrinsic, and chemical diffusivities. It provides information on the applications of single-phase and multiphase diffusion.
Cellular Automaton Models of Recrystallization
Authors: Davies C.H.J.
Published: December 2018

This article examines how cellular automaton (CA) can be applied to the simulation of static and dynamic recrystallization. It describes the steps involved in the CA simulation of recrystallization. These include defining the CA framework, generating the initial microstructure, distributing nuclei of recrystallized grains, growing the recrystallized grains, and updating the dislocation density. The article concludes with information on the developments in CA simulations.
Measurement of Thermophysical Properties at High Temperatures for Liquid, Semisolid, and Solid Commercial Alloys
Authors: Quested Peter , Brooks Robert
Published: December 2018

The measurement of thermophysical properties of metal alloys, especially at high temperatures, is difficult because of the reactivity of some alloys. This article reviews the methods available for measurement of thermal and other physical properties for liquid, semi-solid, and solid commercial alloys, including adiabatic calorimetry, modulated calorimetry, Calvet calorimetry, single-pan calorimetry, and drop calorimetry. It describes differential scanning calorimetry and differential temperature analysis for measuring transition temperatures such as phase transformation or glass transition temperatures. The article schematically illustrates the laser flash apparatus for measuring the thermal diffusivity of solids and oscillation viscometer for measurements of the viscosity of metals. A summary of the measurement methods is presented in tables.
Formation of Microstructures, Grain Textures, and Defects during Solidification
Authors: Jacot A. , Gandin Ch.-A.
Published: December 2018

This article reviews the various aspects of the simulation of solidification microstructures and grain textures. It describes the grain structures and morphology of dendrites or eutectics that compose the internal structure of the grains. A particular emphasis has been put on the simulation of defects related to grain textures and microstructures. The article provides information on the application of the most important simulation approaches and the status of numerical simulation.
Modeling of Dendritic Grain Solidification
Authors: Gandin Ch.-A. , Jacot A.
Published: December 2018

This article discusses the three different modeling approaches for grain structures formed during solidification of metallic alloys: direct modeling of dendritic structure, direct modeling of grain structure, and indirect modeling of grain structure. The main construction bases, the scale at which it applies, and the mathematical background are presented for each modeling approach. The article concludes with a table that presents a comparison of the main inputs/outputs, approximations, numerical methods, kinetics laws, and applications for the three approaches to modeling of dendritic grain solidification.
Simulation of Friction Stir Welding
Authors: Xu Junde , Bernath Jeff J.
Published: December 2018

This article discusses the fundamentals of friction stir welding (FSW) and presents governing equations and an analytical solution for heat transfer. It provides the solutions for structural distortion in FSW. The article describes various techniques that have been adopted to solve the equations and simulate the FSW process. The techniques include modeling without convective heat transfer and modeling with convective heat transfer in a workpiece. The article concludes with information on active research topics in the simulation of FSW.
Finite Element Method Applications in Bulk Forming
Authors: Oh Soo-Ik , Walters John , Wu Wei-Tsu
Published: December 2018

This article provides a summary of the overall development of the finite element method (FEM) and its contribution to the materials forming industry. It focuses on the overall philosophy and evolution of the FEM for solving bulk forming issues. A number of applications of FEM are presented in the order they would be used in a typical manufacturing process sequence: primary materials processing, hot forging and cold forming, and product assembly. The article discusses four FEM modules: the deformation model, the heat-transfer model, the microstructural model, and the carbon diffusion model. The article also covers material fracture and die stress analysis and reviews optimization of the design of forming processes.
Introduction to Medical Implant Materials
Authors: Gibbons Don
Published: December 2018

This article provides a summary of the biocompatibility or biological response of metals, ceramics, and polymers used in medical implants, along with their clinical issues. The polymers include ultrahigh-molecular-weight polyethylene, nonresorbable polymer, and resorbable polymers.
Biologic Aspects of Implant Wear
Authors: Hallab Nadim James
Published: December 2018

Implant debris is known to cause local inflammation, local osteolysis, and, in some cases, local and systemic hypersensitivity. The debris can be stainless steel, cobalt alloy, and titanium alloy, and soluble debris obtained due to wear from all orthopedic implants. This article addresses the biologic aspects of implant debris, both locally and systemically. It describes debris-induced local effects, particle-induced proinflammatory responses, and debris-induced systemic effects. The article concludes with a discussion on the four systemic effects of implant debris, namely, neuropathic effects, hypersensitivity effects, carcinogenicity, and general toxicity.
Tribological Characterization of Biomaterials
Authors: Randall N.X.
Published: December 2018

This article provides an overview of the fundamentals of tribology. It describes the advantages, disadvantages, and applications of the pin-on-disk method, which is the most commonly used configuration for testing biomaterials and for the reproducible measurement of friction and wear. The article illustrates a practical tribocorrosion setup that allows a user to perform wear tests in corrosive environments under well-defined electrochemical conditions and at controlled temperature. It explains the effect of changes in electrical contact resistance on tribological mode. The article discusses various in vivo environmental conditions in tribological tests. Some typical examples of biomaterials testing are also provided.
3D MHD vacuum arc model in VI design
Authors: Schellekens Hans , Wu You , Wang Lijun , Qian Zhonghao , Godechot Xavier
Published: December 2018

Contact geometry evaluation using a full 3D Magneto-Hydrodynamic vacuum arc model is presented. The 3D model uses a two-step approach. The time dependent magnetic field is calculated by Flux3D® using the features of the arc control in axial magnetic field (AMF) type vacuum interrupters (VIs). The arc is modeled by a single fluid description of the arc plasma in Fluent®. Current flow is addressed by Ohms law. The model is applied to 3 contact geometries used in commercial AMF VI’s. The general results of the model like ion density, flow fields and energy flow are represented. It is demonstrated that the external transverse magnetic field created by neighboring phases in a circuit breaker causes off-axis deflection of the heat flow to anode. The deflection in the anti-Amperian direction is attributed to the boundary condition of the current flow at the cathode side.
TEZKİRELER ÜZERİNE BİR BİBLİYOGRAFYA DENEMESİ
Authors: Erken Jülide
Published: December 2018

Kaleme alındıkları dönemde şairlerin
ve eserlerinin unutulmasına mâni olan şu’arâ tezkireleri, Klâsik Türk edebiyatı
tarihinde önemli bir yere sahiptir. Eserlerinde biyografik bilgilere yer veren
tezkire yazarları, bu bilgileri sunarken kendi içinde bir güzelliği ve estetiği
barındıran bir tezkire dili meydana getirmişlerdir. Böylece tezkireler,
biyografik eserler olmalarının yanında edebî eser niteliği de kazanmıştır.
Yaşadıkları dönemin münekkidi olarak görülen tezkire yazarları, eserlerinde terminolojik
değeri olan çeşitli sıfat ve terimleri kullanarak edebî değerlendirmelerde
bulunmuşlardır. Bu bağlamda yazarların oluşturdukları bu dil ile tezkireler birer
tenkit metni olarak da görülmüştür.

Geçmişten günümüze kadar
tezkireler hakkında pek çok çalışma yapılmıştır. Zaman içinde tezkirelerin
günümüz harflerine aktarılması ve dijital ortama taşınmasıyla
bu çalışmalar daha ayrıntılı ve
çok yönlü bir hâle gelmiş, yapılan çalışmaların sayısında bir artış olmuştur. Tezkireler
hakkında yapılan bu çalışmalara araştırmacıların kolaylıkla ulaşabilmesi için bunların
bir araya getirilerek tespit edilmesi gerekmektedir. Bu yönde iki
bibliyografya çalışması bulunmaktadır. Bunlardan ilki M. Fatih Köksal’ın “Türkçe
Şu’arâ Tezkireleri Üzerine Yapılan Çalışmalar Bibliyografyası” (1999), ikincisi
ise Filiz Kılıç’ın “Edebiyat Tarihimizin Vazgeçilmez Kaynakları: Şair
Tezkireleri” (2007) isimli makaleleridir.

Klâsik Türk edebiyatında tezkire denildiğinde akıllara çoğunlukla
şu’arâ tezkireleri gelir ancak evliyâlar, belirli meslek grupları vb. için
kaleme alınan tezkireler de vardır. Bu bağlamda tezkirelerin zengin bir kaynak
olması ve çalışmaların çok yönlü bir şekilde yapılması bakımından bu
bibliyografya çalışması -birkaç istisna dışında- Anadolu sahasında verilen
Türkçe şu’arâ tezkireleri ile sınırlı tutulmuştur. Ayrıca daha önce yapılan
çalışmalar dikkate alınarak, yeni çalışmalarla birlikte tasnif edilmiş ve alfabetik
olarak sıralanmıştır. Böylelikle geçmişten günümüze güncellenerek bir tasnif
ışığında bir araya getirilen bu çalışmalara araştırmacıların ilgi alanlarına
göre daha kolay bir şekilde ulaşması hedeflenmiştir.
A situated practice
Authors: Hillary Fiona
Published: December 2018

A situated practice explores one artist’s approach to navigating the shifts and changes inherent in the public space of the post-industrial city and suburbs of Melbourne, Australia. Collaborative, ephemeral, site-specific, relational works in three specific sites; Station Pier in Port Melbourne, automated pedestrian crossings throughout the city, and at the Western Treatment Plant, the sewerage facility on the western edge of Melbourne’s urban sprawl, explore everyday public sites to stake a claim for the imagination. Engaging with the work of critical theorists including Rosi Braidotti, Franco Bifo Berardi and Donna Haraway I am interested in how the abstraction of ordinary experiences and spaces allow artists and audience to co-constitute the possibility of something other, triggering fleeting transformative acts of imagination. Through this body of work, I am learning how to leave the marks of care for the future and ‘stay with the trouble.’ (Haraway, 2016, p.10).
Efecto de la fertilizacion nitrogenada en el rendimiento y calidad del cultivo de ají escabeche (capsicum baccatum var pendulum) en la estacion experimental Donoso — Huaral
Authors: Irigoyen Diaz Gerardo , Laos Ossa Carlos Alfonso
Published: December 2018

Se evaluaron 5 niveles de fuentes nitrogenadas los cuales fueron T, = 150, 1-2 = 200, T,= 250, T, =300, 'I' =350 unidades de nitrógeno, con fuentes de fósforo =120 unidades y potasio =180 unidades en forma constante.
El experimento se realizo en la estación experimental DONOSO — HUARAL, provincia de Huaral, departamento de Lima entre los meses de marzo a septiembre del 2007.
A nivel de campo fue instalado el experimento agronómico bajo el modelo estadístico diseño bloque completo al azar con 3 repeticiones y 5 tratamientos, comparándose los promedios de las variables con DUNCAN al 0.05%.
Se instalo en almacigo en bandejas de polipropileno de 192 celdas utilizando como sustrato humus de lombriz mas arena lavada permaneciendo las plantas por 45 días para luego efectuar el transplante previo riego de campo aplicándose el herbicida preemergente Prow11-400 (Pendimetalin).
La fertilización se realizo a los 15 días de transplante el primer fraccionamiento aplicándose la mitad de nitrógeno, todo el fósforo y todo el potasio a los 45 días del primer fraccionamiento se realizo el segundo fraccionamiento con la mitad del nitrógeno restante a chorro continuo.
Los resultados de los análisis de varianza y la prueba de DUNCAN 0.05% determino de que con niveles de 350 unidades de nitrógeno se obtuvieron rendimientos de T5 51.69 Tm/Ha, T, 45.20 Tm/Ha, T2 43.84 Tm/Ha en relación con el T3 y TI en donde se obtuvieron 40.07 y 40.68 Tm/Ha. no existiendo diferencias significativas entre bloques.
Para los parámetro biométricos también hubieron para cada respuestas para los T5 y T4, siendo estos influenciados significativamente por la fertilización nitrogenada.
En cuanto a los rendimiento se obtuvieron mayores cantidades a medida que se incrementaban las unidades de nitrógeno con fósforo = 120 y potasio = 180 en forma constante.
estabilidad asintótica en el espectro de un semigrupo fuertemente continuo
Authors: Pacheco Castillo Alexander , Yglesias Jáuregui Miguel Angel
Published: December 2018

El presente trabajo de investigación es un estudio de la estabilidad asintótica de las soluciones del Problema Abstracto de Cauchy dado por la ecuación diferencial de primer orden fue (t) = Au(t) 6(0) = f donde 41: D (A) c x -4 X un operador lineal cerrado densamente definido sobre ur a n` "` " Banach f E D(A)
X, con la condición inicial . Las solucionac sial nrpblema planteado son de la forma t 1-> T (t) f ,donde T(t) es un operador lineal acotado definido en X Juntado todos los opervinnie nt) con t> O en un conjunto denotado por {T(t)}tl° ,éste es llamado Semigrupo Fuertemente continuo o también Semigrupo de Clase Co. Lo importante en semigrupos de clase Co. es que el operador A genera el semigrupo, y dicho operador se ^^-^^-1- como la derivada de la aplicación t T(t)f ,es por que es llamdo generador infinitesimal del semigrupo {(t)}„0.
Cuando se -otudio de los espectros del {T (tnt »o- y semigrupo del generador A, se confirma que éstos están relacionados mediante los Teoremas de Mapeo Espectral, es por esto que el estudio del espectro de un semigrupo es realizado mediante el estudio del espectro de su generador. Los resultados obtenidos nos demuestran que hay distintos tipos de estabilidad asintótica cuando el espectro del generador está contenido en el semiplano izquierdo de los números complejos
Diagnostico de la problemática agraria del distrito de Anta- Carhuaz
Authors: Barreto Rodríguez Juan F.
Published: December 2018

El trabajo de investigación ha tenido por objeto determinar cuales son los factores que afectan directamente la producción y productividad agrícola en el distrito de Anta - Carhuaz. Para ello se realizo una investigación no experimental, consistente en hacer una encuesta a una muestra de 200 familias tomadas al azar de una población de 525 familias del ámbito del distrito a fin de conocer la versión de ellos referente al tamaño de sus chacras, tecnología empleada, modo de conducción de sus cultivos y los problemas y limitaciones que enfrentan. Además se hizo una entrevista a líderes y autoridades del distrito.
Los resultados del estudio han demostrado que las áreas cultivables están ubicadas en laderas de diferente pendiente, que la fertilidad de los suelos es media a baja, que predomina el minifundio, que manejan sus cultivos mayormente en secano supeditados a la presencia de precipitaciones, que utilizan paquetes tecnológicos bajos a medios y que no hay extensión agrícola de parte del estado. Como consecuencia de ello la productividad de sus cultivos es baja, en algunos casos, por debajo del promedio nacional
Desarrollo de un modelo de autoevaluación con fines de acreditación de las carreras profesionales en la UNASAM
Authors: Montañez Muñoz Eddy Jesús , Villalobos Diaz Roosevelt Benel
Published: December 2018

La autoevaluación es una herramienta de gestión institucional que nos dará la oportunidad de reflexionar acerca de la misión de nuestra institución, es voluntario, excepto para las carreras de educación y salud, es un proceso de análisis orientado al cambio y al mejoramiento viable y conducido por sus propios miembros, basado en criterios preestablecidos y se efectúa a partir del perfil o identidad institucional.
Los ejes centrales de evaluación, según el modelo de autoevaluación de la ANR y que se identifican en otros modelos como el de la CNA de Colombia o CNAP de Chile, para apreciar las condiciones de desarrollo de las actividades que deben cumplir las carreras profesionales son el contexto institucional, el proyecto académico, Docentes, alumnos y egresados e Infraestructura y equipamiento. La dimensión Proyecto académico tiene trece factores de los que se han seleccionado los factores currículo y enseñanza aprendizaje para su evaluación en este trabajo de investigación.
Para evaluar los factores señalados se han considerado las variables, los indicadores y las fuentes de verificación (cuantitativas y cualitativas) que permitan valorar la calidad analizando sus contenidos y alcances según la realidad de la escuela profesional de Ingeniería de Sistemas e Informática de la Facultad de Ciencias.
La autoevaluación implicó el desarrollo necesario de las siguientes etapas: Coordinación y comunicación, Diseño del modelo de autoevaluación, Construcción de la Matriz de Ponderación, Construcción de la matriz de Valoración, Construcción de la Matriz Operativa, Recojo, procesamiento y análisis de información, Construcción de la Matriz de Resultados, Formulación de Planes de mejora y la presentación del informe de evaluación.
Del análisis de los resultados del proceso de autoevaluación se determinó las fortalezas y áreas a mejorar; se obtuvo información que orientó la toma de decisiones sobre cambios en la política y prácticas de gestión en las escuela de Ingeniería de Sistemas e Infonnática y se identificó las estrategias para la implementación y el seguimiento de los Planes para la mejora continua de procesos.
El proyecto de investigación, busca implementar una cultura de calidad en nuestra institución, poner a disposición de un modelo que pueda constituirse como mecanismo para impulsar la implementación de la autoevaluación en todas las carreras profesionales de la UNASAM a fin de mantener niveles de calidad reconocidos nacionalmente