bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of increased persistence and intensity of precipitation in the northeastern United States
Authors: Guilbert Justin , Betts Alan K. , Rizzo Donna M. , Beckage Brian , Bomblies Arne
Published: February 2015

We present evidence of increasing persistence in daily precipitation in the northeastern United States that suggests that global circulation changes are affecting regional precipitation patterns. Meteorological data from 222 stations in 10 northeastern states are analyzed using Markov chain parameter estimates to demonstrate that a significant mode of precipitation variability is the persistence of precipitation events. We find that the largest region‐wide trend in wet persistence (i.e., the probability of precipitation in 1 day and given precipitation in the preceding day) occurs in June (+0.9% probability per decade over all stations). We also find that the study region is experiencing an increase in the magnitude of high‐intensity precipitation events. The largest increases in the 95th percentile of daily precipitation occurred in April with a trend of +0.7 mm/d/decade. We discuss the implications of the observed precipitation signals for watershed hydrology and flood risk.
A Guide to Engineering Selection of Titanium Alloys for Design
Authors: Donachie Matthew J.
Published: February 2015

This chapter intends to create a sufficient understanding of titanium and its alloys so that selection of them for specific designs will be appropriate. It provides the user with sufficient knowledge to ask the important technical questions of titanium alloy and product providers. Titanium has two elemental crystal structures: in one, the atoms are arranged in a body‐centered‐cubic (bcc) array; in the other they are arranged in a hexagonal close‐packed (hcp) array. Appropriate compositions of all titanium alloys can be forged, rolled to sheet, or otherwise formed into a variety of shapes. Fabricated structures may contain cast as well as wrought parts although wrought parts are assembled in most applications. Single‐piece forged gas turbine fan and compressor disks are prime applications for titanium alloys. Titanium aluminides have been the subject of multidecades of consideration with interesting but limited economically viable results.
Magnesium and Its Alloys
Authors: Brown Robert E.
Published: February 2015

Magnesium, with a density of 1.74 g/cm
3
, is the lightest of all structural metals. There are two major methods of producing magnesium, electrolytic and thermal reduction. The main electrolytic method of reduction is by electrolysis of magnesium chloride. Thermal reduction is principally achieved by reducing magnesium oxide by ferrosilicon. Magnesium is used in many forms and in many applications. This chapter discusses nonstructural applications and structural applications in detail. It presents a table of magnesium alloys in common use. Methods for fabrication of magnesium are Machining, Joining and Forming. Magnesium is a highly recyclable material consuming only 5% of the energy required to manufacture the primary metal. In order to provide an up‐to‐date picture of a current magnesium life cycle in a transport application, the International Magnesium Association (IMA) has initiated a study on the life‐cycle assessment (LCA) of magnesium in 2012.
Acoustical Measurements
Authors: Anderson Brian E. , Blotter Jonathan D. , Gee Kent L. , Sommerfeldt Scott D.
Published: February 2015

This chapter provides a working knowledge of the basic acoustical or sound measurements and measurement techniques for the practicing engineer. It also provides a broad overview and introduction to more advanced acoustical measurement methods. The chapter discusses the acoustical quantities that are typically measured. It presents the definitions of the terms, measurement units, and weighting filters. The chapter also discusses the various types of microphones. It explains the hardware used to make the measurements along with principles of calibration and data acquisition. The chapter gives the detailed steps to the measurement of sound pressure. It also describes the acoustical measurements important in the areas of sound isolation and room acoustics. The chapter focuses on the measurements of sound intensity and sound power, which are the most advanced measures of a sound field. It concludes with a discussion of sound exposure and noise dosage measurements.
Reliability in the Mechanical Design Process
Authors: Dhillon B.S.
Published: February 2015

Various types of statistical distributions and hazard rate models are used in mechanical reliability to represent failure times of mechanical items. This chapter presents some of the distribution methods and models considered useful to perform various types of mechanical reliability analysis. It presents three statistical or probability distributions. They are exponential, Weibull, and normal. Over the years, many reliability allocation and evaluation methods have been developed for use during the design phase. The chapter presents some of the methods and techniques considered useful, particularly in designing mechanical items. There are many mathematical models available in the published literature that can be used to estimate failure rates of items such as bearings, pumps, brakes, filters, compressors, and seals . It presents some of those models. Failure data provide invaluable information to reliability engineers, design engineers, management, and so on concerning the product performance.
Design for Maintainability
Authors: Geoffrey Okogbaa O. , Otieno Wilkistar
Published: February 2015

Maintenance has been long recognized as necessary to increase a system's reliability, availability, and safety. Maintainability and reliability considerations are playing vital roles in virtually all engineering disciplines. This chapter introduces the probability theory and probability distributions. It gives an introduction into system reliability functions, its measurement parameters, and how system maintenance is related to system reliability. Density or mass functions that are often used to describe random variables that typically occur in a manufacturing setting are discussed. These distributions can be categorized into discrete and continuous. The discrete distributions include binomial, negative binomial, geometric, hypergeometric, and Poisson distributions, while the continuous distributions that are examined include normal, exponential, and Weibull distributions. The chapter also delves into maintenance, definitions and maintenance classifications, and system maintenance modeling. Finally, system availability is discussed as a way to measure the integrity of any maintenance policy of a repairable system.
Physical Ergonomics
Authors: Nussbaum Maury A. , van Dieën Jaap H.
Published: February 2015

This chapter focuses solely on the third domain of physical ergonomics (PE), primarily because of its relevance to mechanical engineering and the design of mechanical processes and systems. PE addresses diverse physical characteristics of humans, including anatomical, dimensional, mechanical, and physiological, as they affect physical activity. The chapter provides the fundamental basis of PE, along with its technical foundation and role in the design process, and also provides the summary of key needs motivating PE research and application. It describes several common PE analytical methods. The chapter demonstrates two practical applications of physical ergonomics in design: manual material handling systems and refuse collection. Material handling systems can be generally categorized as positioners (e.g., lift tables, conveyors), used to place or orient objects, and manipulators (articulated arms, hoists), used to move and/or support objects. Several studies have shown that many refuse collectors indeed suffer from musculoskeletal disorders.
Systems Engineering: Analysis, Design, and Information Processing for Analysis and Design
Authors: Sage Andrew P.
Published: February 2015

This chapter concerns with the engineering of large‐scale systems, or systems engineering. It especially concerns with strategic‐level systems engineering, or systems management. The chapter first discusses the need for systems engineering and then provides some definitions of systems engineering. It presents a structure describing the systems engineering process. The result of this is a life‐cycle model for systems engineering processes. This is used to motivate discussion of the functional levels, or considerations, involved in systems engineering efforts: measurements, systems engineering methods and tools, systems methodology or processes, and systems management. A variety of methods are suitable to accomplish the various steps of systems engineering. Some of the methods described are issue formulation; issue analysis; information processing and interpretation. The chapter discusses several topics relevant to the design and evaluation of systems. To develop the design methodology, it discusses the purpose and objectives of systems engineering and systems design.
Organization, Management, and Improvement of Manufacturing Systems
Authors: Gardiner Keith M.
Published: February 2015

Major large‐scale projects to meet architectural, marine, defense, societal, and funereal purposes (harbors, fortifications, aqueducts, and memorial structures) involved substantial mobilization of resources and possibly the use of slaves captured in wars. Smaller artifacts were made by single artisans or by small groups working collectively; agricultural production was also relatively small scale and primarily for local markets. The manufacturing system provides concept implementation from design through realization of a product and completion of the life cycle to satisfy the customer and society. There are two main motivations for workforce reduction, the initial one being cost reduction and the other being productivity improvements. The growth of information technology (IT) has accelerated a shift from the simple exchange of cash for products or services to entire manufacturing or commercial systems that market solutions enabling customer success, provide experiences, and build continuing relationships.
Environmentally Benign Manufacturing
Authors: Biles William E.
Published: February 2015

The environmentally benign manufacturing movement addresses the dilemma of maintaining a progressive worldwide economy without continuing to damage the environment. The issue of environmentally benign manufacturing is not isolated on the manufacturing function. Environmental issues abound from tier I and II suppliers to the manufacturing system all the way through the supply chain to the consumer. The transportation function in the supply chain is also important in terms of its environmental impacts. The manufacturing process itself is perhaps the most important stage in the supply chain in terms of overall environmental impact. This chapter considers five manufacturing processes that apply to metals and plastics: machining processes, metal casting, metal forming, metal joining, and plastics injection molding. Any company that is morally and ethically committed to the goals of environmentally benign manufacturing cannot scrutinize its manufacturing processes without first giving due consideration to the manufactured product itself.
Production Processes and Equipment
Authors: Zohdi Magd E. , Biles William E. , Webster Dennis B.
Published: February 2015

The desirable properties for cutting‐tool material include the ability to resist softening at high temperature, which is known as red hardness; a low coefficient of friction; wear resistance; sufficient toughness and shock resistance to avoid fracture; and inertness with respect to workpiece material. Drills are used as the basic method of producing holes in a wide variety of materials. The milling machines use a rotary multitooth cutter that can be designed to mill flat or irregularly shaped surfaces, cut gears, generate helical shapes, drill, bore, or do slotting work. Gears are made by various methods, such as machining, rolling, extrusion, blanking, powder metallurgy, casting, or forging. Three basic methods are used for the manufacturing of threads: cutting, rolling, and casting. Saws have two general areas of applications: contouring and cutting off. Nontraditional, or nonconventional, machining processes are material removal processes that have recently emerged or are new to the user.
Coatings and Surface Engineering: Physical Vapor Deposition
Authors: Matthews Allan , Rohde Suzanne L.
Published: February 2015

Plasma or ion assistance in physical vapor deposition (PVD) processes is making possible the creation of coating materials and structures which are unachievable by other deposition techniques. This chapter discusses some basic plasma principles and then outlines some aspects of the influence of plasma bombardment on coating morphology. As Jehn has pointed out, a number of film nucleation and growth models have been published. The chapter considers only those models that rely on empirical observations to describe the nature of film growth morphology under different conditions. Then, the main evaporative and sputtering processes are discussed followed by a description of some hybrid techniques. The simplest sputtering plasma is that of dc diode glow discharge and the chapter provides the model in which the basics of the sputtering processes are discussed.
Mechanical Fasteners
Authors: Roblin Murray J. , Luscher Updated by Anthony
Published: February 2015

This chapter focuses on mechanical fastening via rivets and bolts. It uses the term fastening to correspond to removable features and joining as the creation of a permanent connect. The chapter discusses how a creative consideration of assembly constraint can improve the design of mechanically fastened assemblies. There are two types of riveted and bolted joints: lap joints and butt joints. In friction‐type connections, high‐strength bolts of various grades are used and are tightened to high tensile stresses, thereby causing a large residual compression force between the plates. Both structural steel and pressure vessel codes define maximum design allowable stresses for bolts. To distinguish between maximum design stress and the maximum stress that may be allowed in the fastener during assembly, one need to look at the design safety factor. The chapter examines the way a joint responds when exposed to the external loads it has been designed to support.
Seal Technology
Authors: Steinetz Bruce M.
Published: February 2015

Seals are required to fulfill critical needs in meeting the ever‐increasing system performance requirements of modern machinery. This chapter provides design insight and application for both static and dynamic seals. Static seals reviewed include gaskets, O‐rings, and selected packings. The chapter provides useful insight to designers approaching an O‐ring seal design, including the basic sealing mechanism, preload, temperature effects, common materials, and chemical compatibility with a range of working fluids. Dynamic seals reviewed include mechanical face, labyrinth, honeycomb, and brush seals. Honeycomb seals are used extensively in mating contact with labyrinth knife edges machined onto the rotor in applications where there are significant shaft movements. After brazing the honeycomb material to the case, the inner diameter is machined to seal tolerance requirements. For each of these seals, typical configurations, materials, and applications are covered. Where applicable, seal flow models are presented.
Statistical Quality Control
Authors: Zohdi Magd E.
Published: February 2015

The metric and English measuring systems are the two measuring systems commonly used throughout the world. In dimensioning a drawing, the numbers placed in the dimension lines are only approximate and do not represent any degree of accuracy unless so stated by the designer. Quality control enables an inspector to sample the parts being produced in a mathematical manner and to determine whether or not the entire stream of production is acceptable, provided that the company is willing to allow up to a certain known number of defective parts. Mathematical statistics states that the dimension on an assembled product may be the sum of the dimensions of the several parts that make up the product. Control charts detect changes in a pattern of variation. The objective of acceptance sampling is to determine whether a quantity of the output of a process is acceptable according to some criterion of quality.
TRIZ
Authors: McMunigal James E. , Ungvari Steven , Slocum Michael , McMunigal Ruth E.
Published: February 2015

Teoriya Resheniya Izobretatelskikh Zadatch(TRIZ)'s development, evolution, and refinement cover over 50 years of rigorous, empirically based analysis. The catalyst for TRIZ was a Russian named Genrich Altshulle. Altshuller's three discoveries provide the construct for the formation of the foundational underpinnings upon which all TRIZ theory, practices, and tools are built. The three building blocks of TRIZ are ideality, contradictions, and the maximal use of resources. TRIZ is comprised of a comprehensive set of analytical and knowledge‐based tools that were heretofore buried at a subconscious level in the minds of creative inventors. Knowledge‐based tools include the contradiction matrix, the 40 inventive principles, and the laws of systems evolution. Analytical tools include Su‐Field analysis and ARIZ. The tools of TRIZ are subdivided into two major categories. The first division is by the nature of the tool, e.g., analytical versus knowledge base. The second differentiation is chronological: classical TRIZ versus I‐TRIZ.
Data Exchange Using
STEP
Authors: Hardwick Martin
Published: February 2015

The ultimate goal of STEP is to define models for the entire product life cycle for all kinds of products. Manufacturing needs many specifications to make a product. The most important is a description of the tolerances, but other kinds of specifications are also required, such as the material properties and the surface finishes. The ability to support many protocols within one framework was a key strength of STEP. In the early years it allowed many groups to define protocols. All the protocols were built on the same set of integrated resources (IRs) so they all used common definitions for the same information. Each (application protocol) AP includes a scope, an activity diagram, and an application model describing the information requirements of those activities. These information requirements are then mapped into the common set of IRs and the result is a data exchange standard for the activities within the scope.
Nondestructive Inspection
Authors: Crane Robert L. , Dillingham Giles
Published: February 2015

This chapter deals with the nondestructive inspection (NDI) of materials, components, and structures. Inspection of complex materials and structures is frequently carried out by comparing the expected inspection data with a standard and noting any significant deviations. This means a well‐defined standard must be available for calibration of the inspection instrumentation. Furthermore, standards also must contain implanted flaws that mimic those that naturally occur in the material or structure to be inspected. Without a well‐defined standard to calibrate the inspection process, the analysis of NDI results can be significantly in error. This chapter covers some important and some less well‐known NDI tests. Thermal nondestructive inspection methods involve the detection of infrared energy emitted from the surface of a test object. This technique is used to detect the flow of thermal energy either into or out of a specimen and the effect of anomalies on the surface temperature distribution.
Intelligent Control of Material Handling Systems
Authors: Hallenborg Kasper
Published: February 2015

This chapter starts with an introduction of a more decentralized approach for controlling systems for manufacturing and material handling. Different approaches for intelligent control is discussed, and finally two cases of material handling is presented, one large‐scale complex system of baggage handling in an airport and the other a case of scheduling items through a manufacturing process. A conceptual introduction to agent technologies is given which summarizes some of the important characteristics about both the single agent and when they collectively become a multiagent system. Architectures which describe the internal structure of the agent were discussed in the perspective of different agent types. Reactive agents directly respond to perceived inputs, whereas deliberative agents proactively pursue their own goals. This chapter introduced a number of structures to facilitate this, such as a hierarchical or team‐based organization.
Managing People in Engineering and Technology
Authors: Thamhain Hans J.
Published: February 2015

The nature of engineering management, with its multidisciplinary technology requirements, ambiguous authority definition, and complex operating environment, requires experience and sophistication for effective role performance. Tools such as the Project Maturity Model and the Six Sigma Management Process can provide the framework and tool set for analyzing and fine tuning the team development and its management process. Managerial leadership has significant impact on the work environment, affecting engineering personnel and performance. Factors that satisfy personal and professional needs such as professional interest, pride and satisfaction with the work, professional work challenge, accomplishments and recognition seem to have the most favorable impact on individual and team performance, reducing communication barriers while enhancing collaboration and the desire to succeed. Effective engineering managers are social architects who understand the interaction of organizational and behavioral variables who can foster a climate of active participation, accountability, and result orientation throughout the enterprise and its partners.
Engineering Economy
Authors: Abel Kate D.
Published: February 2015

Engineering Economics provides the tools needed to compare the varied technologies on a level playing field. No matter what technologies or technological solutions are being compared whether they be the same or very different often the solution chosen is the one of least cost. Engineering Economics, therefore, provides a rational selection process to determine how to allocate capital. There are two main types of Engineering Economic decisions. The first is a capital expenditure decision. The second kind decision involves cost reduction. Since Engineering Economics is applicable to all disciplines of engineering, it is a required section of the fundamentals in engineering (FE) exam as well as the professional engineering (PE) exam, necessary to attain a professional license. Engineers faced with design decisions that deal with multiple designs, methods or materials commonly encounter the topic of engineering economics.
Lean Management
Authors: Stapp Eric H. , Sabelhaus Cynthia M.
Published: February 2015

Lean management is a philosophy that encompasses all activities from manufacturing to leadership to supply chain interaction. This philosophy includes a number of tools and methods for its implementation and has been responsible for saving costs and improving quality and profitability in U.S. organizations. Although the plan‐do‐check‐act (PDCA) cycle was not born in Japan, it is sometimes called the lean operating framework. While Kaizen is a philosophy of continuous improvement, Kaizen events or blitzes are discrete activities that bring people together to quickly improve the value stream. 5S is a workplace organization method. The name stems from five Japanese words:
seiri, seiton, seiso, seiketsu, and shitsuke
. As the total quality management movement took hold in the 1970s and 1980s, a group of graphical quality control techniques arose as primary data collection and process improvement tools.
Safety Engineering
Authors: ReVelle Jack B.
Published: February 2015

As workplace environments become more technologically complex, the necessity for protecting the workforce from safety and health hazards continues. This chapter addresses the topics and provides the information that engineering practitioners require to professionally perform their responsibilities with respect to the safety of the workforce. The Occupational Safety and Health Act (OSHAct) encourages each state to assume the fullest responsibility for the administration and enforcement of occupational safety and health programs. System safety techniques can provide meaningful predictions of the frequency and severity of accidents. Machine tools provide an example of commonplace conditions where only a limited number of items of personal protective gear are available for use. The type of operation, the size or shape of stock, the method of handling the physical layout of the work area, the type of material, and production requirements or limitations all influence selection of the appropriate safeguarding method(s) for the individual machine.
Patents
Authors: Burge David A. , Burge Benjamin D.
Published: February 2015

This chapter describes the four different types of patent applications that can be filed, the three different types of patents that can be obtained, and what rights are associated with the grant of a patent. It then focuses on topics such as inventions that qualify for patent protection and procedures that are involved in obtaining a patent. The discussion of patents presented in the chapter applies only to U.S. patents and principally to utility patents. For an invention to be patentable, it must meet several requirements set up to ensure that patents are not issued irresponsibly. Once an executed patent application has been received by the U.S. Patent and Trademark Office (USPTO), the patent application is said to be pending, and a serial number and filing date are assigned to it by the USPTO. Patent rights cannot be enforced against infringers until a patent has issued.
Mechanics of Incompressible Fluids
Authors: Ogretim Egemen Ol , Huebsch Wade W.
Published: February 2015

This chapter covers the basics on many of the fluid classifications. Some common fluid classifications are viscous or inviscid, compressible or incompressible, laminar or turbulent, Newtonian or non‐Newtonian, and steady or unsteady. The chapter presents the properties of fluids generally encountered in engineering practice. Included are the commonly used properties of density, specific gravity, bulk modulus (compressibility), viscosity, surface tension, and vapor pressure. Based on the radial variation of the strength of the rotation, two major types of vortices are assumed: forced vortex and free vortex. Viscous flows are typically classified as laminar or turbulent, although in any given flow there may be regions of both laminar and turbulent flow Similitude and dimensional analysis are inextricably tied to experimental testing and the analysis of experimental data.The chapter discusses the flow about immersed objects for the case of an ideal (frictionless) fluid.
Heat Transfer Fundamentals
Authors: Peterson G. P.
Published: February 2015

The exchange of energy or heat resulting from the kinetic energy transferred through the direct impact of molecules is referred to as conduction and takes place from a region of high energy to a region of lower energy. Convection heat transfer is the mode of energy transport in which the energy is transferred by means of fluid motion. Heat transfer can occur in the absence of a participating medium through the transmission of energy by electromagnetic waves, characterized by a wavelength, λ, and frequency, v, which are related by c = λv. Energy transmitted in this fashion is referred to as radiant energy and the heat transfer process that occurs is called radiation heat transfer or simply radiation. Boiling and condensation are both forms of convection in which the fluid medium is undergoing a change of phase.
Temperature Measurement
Authors: Childs Peter R. N.
Published: February 2015

Temperature is the property that determines whether a system is in thermal equilibrium with other systems. If the temperature of two bodies in thermal contact with each other is the same, then there will be no net transfer of thermal energy. Despite the many types of temperature‐measuring systems, the choice for a given application is typically limited by a number of factors, including uncertainty, temperature range, thermal disturbance, level of contact, size of the sensor, transient response, sensor protection, availability, and cost. This chapter provides a review of a range of invasive, semi‐invasive, and noninvasive instrumentation along with an introduction to the measurement process, calibration, and traceability. Some applications permit the installation of a sensor on or within the medium of interest. Alternatively it may be desirable to observe the target remotely using an infrared pyrometer, a thermal imager, or other form of noninvasive method.
Heat Flux Measurement
Authors: Diller T. E.
Published: February 2015

This chapter reviews the most useful current heat flux instrumentation, particularly heat flux gauges. It also briefly discusses the optical methods, but these are generally research methods that require sophisticated equipment and data processing techniques. General principles for the proper use of heat flux gauges are discussed first, followed by the details of specific gauges along with some of their typical applications. Three classifications of gauges are considered based on measured temperature difference over space, the temperature change with time, and the power dissipated at a maintained temperature. The measurement methods are also categorized according to the type of temperature measurement. The three common techniques are thermocouples, resistance temperature devices (RTDs), and optical. Finally, the chapter discusses the calibration of heat flux gauges along with error analysis. There are a number of problems and complications that should be taken into account while planning for any heat flux measurements.
Heat Pipes
Authors: Ma Hongbin
Published: February 2015

The heat pipe is a device that utilizes the evaporation heat transfer in the evaporator and condensation heat transfer in the condenser in which the vapor flow from the evaporator to the condenser is caused by the vapor pressure difference and the liquid flow from the condenser to the evaporator is produced by the capillary force, gravitational force, electrostatic force, or other forces directly acting on it. A typical heat pipe consists of three sections: an evaporator or heat addition section, an adiabatic section, and a condenser or heat rejection section. For a heat pipe to function, the capillary pressure difference occurring in the heat pipe must always be greater than the summation of all the pressure losses occurring throughout the liquid and vapor flow paths. One of the simplest heat pipes is the thermosyphon. Cryogenic fluids are used in the cryogenic heat pipe.
Cooling Electric Equipment
Authors: Kraus Allan , Bar‐Cohen Avram , Wative Abhay A.
Published: February 2015

To determine the temperature differences encountered in the flow of heat within electronic systems, it is necessary to recognize the relevant heat transfer mechanisms and their governing relations. In a typical system, heat removal from the active regions of the microcircuit(s) or chip(s) may require the use of several mechanisms, some operating in series and others in parallel, to transport the generated heat to the coolant or ultimate heat sink. Practitioners of the thermal arts and sciences generally deal with four basic thermal transport modes: conduction, convection, phase change, and radiation. This chapter discusses the heat transfer correlations in geometries peculiar to electronic equipment. Two thermoelectric effects are traditionally considered in the design and performance evaluation of a thermoelectric cooler: Seebeck effect and Peltier effect. Finally, the chapter describes the various thermal control techniques.
Refrigeration
Authors: O'Neal Dennis L.
Published: February 2015

This chapter focuses primarily on refrigeration applications, which cover such diverse uses as food processing and storage, supermarket display cases, skating rinks, ice manufacture, and biomedical applications such as blood and tissue storage or hypothermia used in surgery. Most refrigeration systems utilize the vapor compression cycle to produce the desired refrigeration effect. There are four basic components in every vapor compression refrigeration system: compressors, condenser, expansion device, and evaporator. Refrigeration can be accomplished in either closed‐cycle or open‐cycle systems. Ammonia is a popular refrigerant for many industrial and large warehouse applications. Absorption systems offer three distinct advantages over conventional vapor compression refrigeration. For indirect refrigeration, the process or refrigeration load is cooled by an intermediate liquid, which is itself cooled by refrigerant typically in a conventional vapor compression cycle. Several defrost methods are used with refrigeration systems: hot refrigerant gas, air, and water.
Cryogenic Engineering
Authors: Weisend J. G.
Published: February 2015

Cryogenic engineering involves the technology required to both produce and maintain extremely low temperatures. It takes into account the unique properties of fluids and materials at cryogenic temperatures as well as the specific techniques required to operate safely and efficiently at these temperatures. Cryogenic engineering is broad based, using aspects of mechanical, electrical, chemical, and other engineering disciplines. Cryogenic fluids, or cryogens, may be defined as those whose boiling temperature at 1 bar (normal boiling point) is less than 120 K. Good cryogenic engineering practice includes never using materials at cryogenic temperatures unless their behavior at those temperatures is well understood and never extrapolating room temperature properties down to cryogenic temperatures. Cryogenic engineering at sub‐Kelvin temperatures poses a number of challenges. In particular, the heat capacities and available cooling at these temperatures is so small that even microwatt‐scale heat leaks can result in unacceptable temperature rises.
Indoor Environmental Control
Authors: Srebric Jelena
Published: February 2015

Heating, ventilating, and air‐conditioning (HVAC) systems are major engineering systems that significantly affect the country's overall energy consumption and occupants' well‐being through control of indoor air parameters. The indoor environment parameters that are controlled by HVAC depend on the type of the building. The primary purpose of HVAC systems is to maintain thermal comfort for building occupants. Indoor air quality (IAQ) plays a significant role in occupants' well‐being, satisfaction, and health, due to the prolonged time periods spent indoors in a modern society. The building thermal loads represent the thermal energy that is removed (cooling loads) or added (heating loads) to a building in order to keep the occupants thermally comfortable, which is the primary function of an HVAC system. From the perspective of HVAC systems, building simulation programs can be classified as either building energy simulation programs or building airflow simulation programs.
Thermal Systems Optimization
Authors: Aute Vikrant C.
Published: February 2015

Thermal systems include all functional groups of equipment and working fluids that are designed for the purpose of managing temperature and humidity conditions inside various spaces or materials. The optimization of thermal systems usually includes a mixture of technology decisions and the optimization of specific properties of selected components. This chapter presents more advanced approximation‐assisted optimization (AAO) techniques to efficiently optimize computationally expensive heat exchanger models. It also presents two examples for chevron plate heat exchanger segment optimization and the new generation of air‐cooled heat exchanger optimization. There are two basic components, the optimization driver and the simulation tool. The chapter presents case studies that illustrate optimization strategies for various thermal systems. The computational cost is prohibitive when applying optimization algorithms to computationally expensive simulations such as models based on finite element (FE) or computational fluid dynamics (CFD). One way to address this problem is to use AAO techniques.
Combustion
Authors: Eddings Eric G.
Published: February 2015

Combustion is rapid oxidation, usually for the purpose of changing chemical energy into thermal energy—heat. This energy usually comes from oxidation of carbon, hydrogen, sulfur, or compounds containing C, H, and/or S. The purpose of combustion in industrial applications, for the most part, is to transform chemical energy, available in various types of fuels, to thermal energy or heat to be of use in the processing of gas or liquid streams or solid objects. This chapter examines how burner aerodynamics is often the most important factor. It describes the most commonly encountered firing systems for gaseous, liquid, and solid fuels. A firing system provides for mixing of fuel with an oxidizer (typically air) in a manner that promotes stable combustion and desired heat release rates. Combustion processes produce gaseous and particulate emissions that can be harmful to human health and the environment.
Gaseous Fuels
Authors: Reed Richard J.
Published: February 2015

Gaseous fuels are generally easier to handle and burn than are liquid or solid fuels. Gaseous fossil fuels include natural gas (primarily methane and ethane) and liquefied petroleum gases (LPGs) primarily propane and butane. Gaseous man‐made or artificial fuels are mostly derived from liquid or solid fossil fuels. Liquid fossil fuels have evolved from animal remains through eons of deep underground reaction under temperature and pressure, while solid fuel evolved from vegetable remains. Properties that concern most users of natural gases relate to the heat available from their combustion, flow characteristics, and burnability in a variety of burner types. Natural gases are classified as “sweet” or “sour,” depending on their content of sulfur compounds. Properties that concern most users of natural gases relate to the heat available from their combustion, flow characteristics, and burnability in a variety of burner types. LPGs are by‐products of natural gas production and of refineries.
Liquid Fossil Fuels from Petroleum
Authors: Reed Richard J.
Published: February 2015

The major source of liquid fossil fuels is crude petroleum; other sources are shale and tar sands. Synthetic hydrocarbon fuels—gasoline and methanol—can be made from coal and natural gas. Ethanol, some of which is used as an automotive fuel, is derived from vegetable matter. Properties of fuels reflect the characteristics of the crude. Paraffinic crudes have a high concentration of straight‐chain hydrocarbons, which may leave a wax residue with distillation. Aromatic and naphthenic crudes have concentrations of ring hydrocarbons. Asphaltic crudes have a preponderance of heavier ring hydrocarbons and leave a residue after distillation. Kerosene is used mainly in wick‐fed illuminating lamps and kerosene burners. The most important requirements of aircraft jet fuel relate to freezing point, distillation range, and level of aromatics. The chapter lists the properties of a residual fuel oil (DMF) from one shale pilot operation and of a shale crude oil.
Clean Power Generation from Coal
Authors: Butler James W. , Basu Prabir
Published: February 2015

Coal has consistently accounted for about 40% of the world's total electricity generating capacity since the early 1970s, despite the steady growth of the total generation capacity. A number of technologies are available or under development to make the process of converting coal into a transmittable form of energy a less polluting process. These technical options can be broadly divided into the following three categories, based on which stage of the conversion process the pollutant reduction takes place: preconversion technology, In situ control technology, postconversion technologies. As emission standards become more stringent, new and cleaner ways of converting coal to usable forms of energy are being developed and implemented. Postconversion clean‐up is necessary for all types of coal‐fired plants to reduce their environmental impact. Coal produces more carbon dioxide than any other fossil fuel, and as such, the concern over global warming is a major issue with coal‐fired power plants.
Pumps, Fans, Blowers, and Compressors
Authors: Marchildon Keith , Mody David
Published: February 2015

The continuous transport of a liquid requires a pump, and the continuous transport of a gas or vapor requires a fan, blower, or compressor. All of these devices are described by the general term fluid movers. Specialized fluid movers are required for the transport of liquid‐and‐gas mixtures and of slurries and suspensions of solids in liquid or gas. The vast majority are mechanically driven. A few eductors and ejectors use another fluid as the motive source This chapter is organized into two broad sections i.e.; on liquid transport and on gas transport, and within each section it describes the technology of both the dynamic and the positive‐displacement devices. In the case of gas compression, where pressure, volume, and temperature are all in flux, an outline of the relevant thermodynamics is provided. Dynamic devices include centrifugal, axial, mixed flow, and jet pumps.
Cogeneration
Authors: Caton Jerald A.
Published: February 2015

This chapter presents a brief overview of cogeneration systems, which includes introductory comments, descriptions of basic systems and terminology, descriptions of prime movers and major equipment, some comments on technical designs, a summary of relevant regulations, descriptions of economic evaluations, and comments on financial and ownership aspects. A cogeneration system may be classified as either a topping‐cycle system or a bottoming‐cycle system. Cogeneration systems consist of several major pieces of equipment and many smaller components. The chapter describes the other major equipment (electrical equipment, heat recovery devices, absorption chillers, and balance of plant equipment). The selection of a prime mover for a cogeneration system involves the consideration of a variety of technical and nontechnical issues. The chapter includes overviews of the relevant federal regulations on electric power generation by cogenerators and the related environmental constraints. Cogeneration systems are attractive options for facilities where electrical power and thermal energy are used.
Fuel Cells
Authors: Mench Matthew M. , Zhang Feng‐Yuan
Published: February 2015

Early development of fuel cells had a focus on use of coal to power fuel cells, but poisons formed by the gasification of the coal limited the fuel cell usefulness and lifetime. Potential applications of fuel cells can be grouped into four main categories: transportation, portable power, stationary or grid‐based power, and niche applications. Stationary and distributed power applications include power units for homes or auxiliary and backup power generation units. This chapter discusses the particular limitations and advantages of several different fuel cell systems. The operating principle of a fuel cell is similar to a common battery, except that a fuel (hydrogen, methanol, or other) and oxidizer (commonly air or pure oxygen) are brought separately into the electrochemical reactor from an external source, whereas a battery has stored reactants. The solid oxide fuel cells (SOFC) and molten carbonate fuel cell (MCFC) represent high‐temperature fuel cell systems.
Fluid Power Systems
Authors: Alleyne Andrew
Published: February 2015

The use of fluids for power delivery has been a part of human civilization for many centuries. One key advantage of fluid power systems is the high power density available. This chapter illustrates some of the basic hydraulic symbols and terms that is commonly encountered and is referred. The oil used in a hydraulic circuit is designed to withstand high pressures and large pressure drops without deterioration in performance. The primary other types of common fluids are synthetic ones, including phosphate ester or silicone‐based fluids. In a fluid power system, the hydraulic valve serves to restrict the flow of fluid through the system. This chapter details several of the components that make up a fluid power system. These components are useful only when they are combined and integrated into an overall system. There are some key nonlinearities that are common in fluid power systems and greatly affect their dynamic performance.
Thermally Stable, Biocompatible, and Flexible Organic Field‐Effect Transistors and Their Application in Temperature Sensing Arrays for Artificial Skin
Authors: Wu Xiaohan , Ma Yan , Zhang Guoqian , Chu Yingli , Du Juan , Zhang Yin , Li Zhuo , Duan Yourong , Fan Zhongyong , Huang Jia
Published: February 2015

Application of degradable organic electronics based on biomaterials, such as polylactic‐co‐glycolic acid and polylactide (PLA), is severely limited by their low thermal stability. Here, a highly thermally stable organic transistor is demonstrated by applying a three‐arm stereocomplex PLA (tascPLA) as dielectric and substrate materials. The resulting flexible transistors are stable up to 200 °C, while devices based on traditional PLA are damaged at 100 °C. Furthermore, charge‐ trapping effect induced by polar groups of the dielectric is also utilized to significantly enhance the temperature sensitivity of the electronic devices. Skin‐like temperature sensor array is successfully demonstrated based on such transistors, which also exhibited good biocompatibility in cytotoxicity measurement. By presenting combined advantages of transparency, flexibility, thermal stability, temperature sensitivity, degradability, and biocompatibility, these organic transistors thus possess a broad applicability such as environment friendly electronics, implantable medical devices, and artificial skin.
MEMS: Enabled Drug Delivery Systems
Authors: Cobo Angelica , Sheybani Roya , Meng Ellis
Published: February 2015

Drug delivery systems play a crucial role in the treatment and management of medical conditions. Microelectromechanical systems (MEMS) technologies have allowed the development of advanced miniaturized devices for medical and biological applications. This Review presents the use of MEMS technologies to produce drug delivery devices detailing the delivery mechanisms, device formats employed, and various biomedical applications. The integration of dosing control systems, examples of commercially available microtechnology‐enabled drug delivery devices, remaining challenges, and future outlook are also discussed.