bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Graduate Course: Using Simulation Models for Engineering Design
Authors: Barton Russell R. , Schruben Lee W.
Published: March 2007

Supercomputers and low cost high power workstations provide opportunities for the expanded use of large scale simulation models, allowing multiple runs for model validation, sensitivity analysis, or engineering design. Today's practicing engineers use these computing resources to help do design, often through ad hoc strategies for multiple runs of CAD software. Today's students in engineering and science have little access to formal training in the intelligent manipulation of the models that they develop. This paper describes a modern graduate course in engineering design, with a focus on the exercise of computer models to create new device designs, not just to analyze existing designs. Versions of the course have been offered at Cornell, Georgia Tech, and Penn State, to graduate students from a variety of engineering disciplines. Students exercise their knowledge of lecture materials using case studies based on state-of-the-art computer simulation models from industrial sponsors. The multidisciplinary nature of the course provides a foundation for more effective concurrent engineering manufacturing/design teams.
Evolving A Rule-Based Fuzzy Controller
Authors: Cooper Mark G.
Published: March 2007

In this article we demonstrate the application of genetic algorithms (GAs) to the automatic generation of fuzzy process controllers. Since each controller is represented as an unordered list of an arbitrary number of rules, the algorithm evolves both the composition and size of the rule base from initial randomness. Evolving controllers in the form of a rule base offers unique flexibility exceeding that of prior genetic efforts. The key to this methodology is the observation that the genetic algorithm does not merely evolve bit strings, but operates over a higher-level space of control rules. Both aspects are factors in the learning algorithm. To preserve rule integrity in a reproducing pair of strings, the combined loci must match semantically. This was the obstacle that hindered prior rule-based genetic fuzzy approaches. We demonstrate our algorithm by its application to the boat rudder control problem. We believe that this methodology has great potential for scalability since string size varies with the number of rules and not the number of variables or partitions. Finally, the method's generality permits its further application to the evolution of any system that can be specified as a set of rules.
Generating Simulation Models from Natural Language Specifications
Authors: Cyre W.R. , Armstrong J.R. , Honcharik A.J.
Published: March 2007

A prototype system for the automatic generation of VHDL simulation models from requirements expressed in natural language is described. Requirements are parsed and analyzed semantically to produce knowledge representations called conceptual graphs. Multiple references (coreferences) to objects (values and devices) are detected among the graphs so they can be integrated into a single graph representing the given requirements. The graph is then searched for behavioral concepts (actions, events and states) and objects (values, devices and carriers) which are translated into VHDL processes and signals or data values. Causal dependencies represented in the graph are used to organize the behavioral information into if-statements. The resulting collection of processes and signal definitions are then formatted into a VHDL entity for simulation. A designer will first need to define any types left unspecified in the requirements. A simple example for a multi-function register is given, and results of experiments generating VHDL models of up to 60 lines from descriptions of up to 10 sentences are tabulated.
Simulation of Hazardous Material Fallout for Emergency Management During Accidents
Authors: Bruzzone Agostino G. , Giribone Pietro , Mosca Roberto
Published: March 2007

This article proposes a model to evaluate hazardous material fallout. The problem is particularly pertinent since the transport, storage and production of this type of product often occur close to inhabited areas and, in case of accidents, it is important to correctly estimate the lines of action and risk areas. This model can also be used to evaluate the environ mental risk related to specific hazardous installations and therefore can be used to improve industrial planning.
The Environmental Necessity for Higher-Yield Agriculture
Authors: Avery Dennis T.
Published: March 2007

Here we present edited, condensed excerpts from a paper presented at the Annual Meeting of the American Associa tion for the Advancement of Science in Baltimore, Mary land, on 10 February 1996, entitled
A Simulator Design for Studying Operating Systems: Related Issues
Authors: Rao Anil , Ammar Reda A.
Published: March 2007

Using simulators to study the behavior and performance of operating systems is gaining popularity. In this paper, a new simulator design is presented that can be used to quickly assemble a basic prototype that captures most of the functionality of modern multi-tasking operating systems. The design technique is modular and allows the designer to choose the correct level of detail to suit his/her model. It takes into consideration detailed timing information of individual system tasks, and thereby provides results with a high level of accuracy. A new modeling approach is introduced that improves input jobs descriptions. It is also shown how the scope of the basic simulator can be easily extended for studying more complex systems, such as distributed computing environments.
Simulation of Fatal Time of a Bullet Wound Victim
Authors: Rashidur Rotab Khan M.
Published: March 2007

The research reported in this paper focuses on simulating the fatal time of a victim with a bullet wound in his chest. The idea is accomplished through the development of a digital simulation model by expansion and modification of the PHYsiological Simulation Benchmark Experiment (PHYSBE) analog model. The digital simulation program has been written in FORTRAN. It simulates the fatal time using different rates of bleeding from the left ventricle of the heart of a bullet wound victim. This simulation study may prove important and useful in various physiological and cardiovascular studies, rescue operations, biomedical engineering, clinical, and other research findings to help derive conclusions with greater confidence.
Performance Analysis of the Knockout Switch Under Bursty Traffic Based on a Stochastic Activity Network Model
Authors: Kant Latha , Sanders William H.
Published: March 2007

The possibility of Asynchronous Transfer Mode (ATM)-based B-ISDNs has made desirable the integration of diverse services like voice, data, and multimedia. The success of these high-speed networks is critically dependent on the availability of Fast Packet Switches (FPS) with the capacity to switch and route at high speeds and to provide the required Quality of Service (QoS). The diversity of the applications, however, leads to widely differing QoS demands. The knockout switch is an FPS with low cell-loss probability and latency under steady input traffic. In this paper, we analyze the performance of the knockout switch in terms of cell loss probabil ities and distribution of queue length for a wide range of burst parameters. The switch is modeled using Stochastic Activity Networks (SANs), and the underlying Markov processes are generated and solved using UltraSAN. The results provide useful information about the switch sensitivity and robustness under a variety of burst parameters and illustrate the appropriateness of SANs for modeling and analyzing telecommunication switch architectures.
Coupling Non-Linear Models in Object- Oriented Simulation: Application to Drives with Multiple Induction Motors
Authors: Kawecki Leszek , Raczynski Stanislaw
Published: March 2007

Object-oriented simulation is an excellent tool while treating models of complex systems. The model can be decomposed into several submodels and the structure of the simulation program can be similar to the structure of the real system. In this article the problem of simulation and control of a set of interconnected induction motors is considered. Models of such kind can be useful while working on control problems for complex mechanisms driven by multiple motors, such as belt or chain conveyers or some transport facilities. In particular, an application of the simulation system PASION™ is described. Possible applications of the model in control problems related to the system stability and performance are pointed out.
An Example of a Discrete-Event Simulation on a Spreadsheet
Authors: Greasley Andrew
Published: March 2007

Computer spreadsheets are widely used for a variety of modelling tasks and provide an interface that is well understood by most users. This paper presents a discrete-event simulation system using a spreadsheet as an input/output device which provides a platform on which to widen the base of simulation users. In an educational setting the system can provide an introduction to the student of the concepts behind the discrete-event method. Once the students grasp these concepts, they are better equipped to construct models using specialised simulation software. In a business setting the system could provide an introduction to the technique to a new set of end-users. A case study of a supermarket system is presented to show how the software can be used in an educational context.
Network-Centric Simulation Using NCSOS
Authors: Colvin Kurt , Beaumariage Terrence
Published: March 2007

The Network-Centric Simulation Object System (NCSOS) is a prototype object- oriented, discrete-event simulation environ ment that was designed using a network-centric computing architecture. Developed primarily for use as a manufac turing system simulation environment, simulation models in NCSOS incorporate a mixture of both local and network-based simulation objects. Using NCSOS, a simulationist builds models by selecting a collection of manufacturing workstations. While some of the simulation workstation objects are located on the computer's local file system, the other workstation objects are located on a remote computer connected to the Internet. This distribution of objects is the innovative approach of network-centric simulation modeling using our environ ment. In this article, we present our simulation environment that was developed in Java using a network-centric architecture.
Simulation and Planning of an Intermodal Container Terminal
Authors: Gambardella Luca Maria , Rizzoli Andrea E. , Zaffalon Marco
Published: March 2007

A decision support system for management of an intermodal container terminal is presented. Among problems to be solved are the spatial allo cation of containers in the terminal yard, the allo cation of resources, and the scheduling of opera tions to maximise a performance function based on economic indicators. These problems are solved using techniques from optimisation, such as job-shop scheduling, genetic algorithms or mixed-integer linear programming. At the termi nal, the same problems are usually solved by the terminal manager, using only his experience. The manager can trust computer-generated solutions only by validating them by means of a simulation model of the terminal. Thus, the simulation tool also becomes a means to introduce new ap proaches into traditional settings. We focus on the resource allocation problem and describe our modules for optimisation of the allocation process and the simulation of the terminal. The former is based on integer linear programming; the latter is a discrete-event simulation tool based on the pro cess-oriented paradigm. The simulator provides a testbed for checking the validity and robustness of the policy computed by the optimisation module.
The Effects of Protease Inhibitors on the Spread of HIV and the Development of Drug-Resistant HIV Strains: A Simulation Study
Authors: Zaric Gregory S. , Brandeau Margaret L. , Bayoumi Ahmed M. , Owens Douglas K.
Published: March 2007

Recent advances in the development of protease inhibi tors offer the promise of significantly longer lives for many HIV-infected individuals. However, the drug dosing regimens are often difficult for patients to follow, and non-compliance can enhance the development of drug-resistant strains of HIV. This paper uses com puter simulation to analyze the effects of such "multi- drug therapy" and treatment compliance on the spread of HIV and of multi-drug-resistant HIV strains. The analysis is based on a dynamic compartmental model of the epidemic simulated using Excel, a spreadsheet package. Our analysis shows that multi-drug therapy can lead to significantly high prevalence of multi-drug- resistant HIV strains. Even under optimistic assump tions about rates of compliance and rates at which drug resistance develops, the development of multi-drug- resistant HIV strains in the population may be sig nificant. Our analysis shows that the most important factors affecting the development of multi-drug-resis tant HIV strains are initial and continuing compli ance with treatment. New treatments that are easier to comply with or behavioral interventions that increase patients' compliance could significantly reduce the spread of multi-drug-resistant HIV strains.
HIV Screening and Treatment of Pregnant Women and Their Newborns: A Simulation-Based Analysis
Authors: Anderson James G. , Anderson Marilyn M.
Published: March 2007

Clinical trials have shown that HIV-positive preg nant women treated with zidovudine during preg nancy and delivery have a much lower rate of HIV transmission to their newborns. Recent studies have also shown the effectiveness of antiretroviral therapy combined with elective cesarean delivery and a short- term antiretroviral therapy. In this study a dynamic computer model was built. The model was used to estimate economic consequences of testing pregnant women for HIV virus and treating the HIV-positive women and their newborns with three different reg imens. Outcomes of data analysis included costs and the number of avoided cases of perinatal transmission of the HIV virus. The study found that while the over all costs of the three treatment programs were simi lar, the short-term antiretroviral program was the least cost-effective and prevented fewer cases of peri natal transmission of the virus. Sensitivity analysis found that the cost-effectiveness of the treatment pro grams were differentially sensitive to screening and treatment rates. Cost-effectiveness of all regimens is highly sensitive to the HIV infection rate among preg nant women. When the rate reaches four to five per 1,000, treatment cost savings from the reduction in pediatric HIVcases exceed the costs of screening and treatment. The model presented provides a useful tool to be used to evaluate treatment programs designed to pre vent mother-to-infant transmission of the HIV virus.
A Software Architecture for Interoperable, Evolvable, Near Real-Time Simulations
Authors: Cioch Frank A. , Sieh Larry
Published: March 2007

An architecture based on the design concept of data communication encapsulation via a layer of abstraction has been developed for simulations to interoperate asynchronously in near real time. It has been used to develop ground vehicle simulations for a variety of Army programs. One benefit is that resulting simulations are interoperable and evolvable to accommodate technological and methodological advances in hardware and software. The development pro cess also benefits, because in order to effectively utilize the architecture, designers must first specify all subsystem interactions. This facili tates requirements-to-design mapping before coding, reduces rework during system integra tion, and promotes designing using application domain concepts.
Simulation of a Multicast ATM Switch for High-Speed Networks
Authors: Chaudhry G.M. , Guizani M.
Published: March 2007

In this paper, a new multicast switch structure (called CCRMS) is proposed that can achieve high throughput at low hardware cost. Instead of using two separate parts, copying and routing networks, the CCRMS uses a combined network, called the copying-routing network (CRN). Additionally, a cell management algorithm is developed for the proposed multicast switch. This cell scheduling algorithm allows cells to be duplicated and routed in the CCRMS without suffering any blocking. The proposed switch hardware architecture will be more economical to fabricate than other multicast switches since both copying and routing functions are performed using a single network, yet its throughput is not sacrificed. With this proposed switch architecture executing the proposed efficient cell management algorithm, a high throughput, non-blocking, and low cost multicast switch can be built.
The Parish and Social Integration
Authors: Fichter Joseph-H.
Published: March 2007

Dans le système social américain, l'intégration sociale des catholiques ne se fait pas via la paroisse, car ils participent à l'ensemble de la vie sociale dans des organismes qui ne sont pas spécifiquement chrétiens. La paroisse n'est donc pas l'instrument principal d'in tégration sociale des catholiques. Elle peut y contri buer en orientant ses membres vers l'extérieur. La paroisse, communauté territoriale, groupant en un groupe toutes les personnes habitant sur le territoire, est un concept rural, qui a de moins en moins de consis tance dans notre monde urbanisé.
Paganization and dechristianization, or the crisis in institutional symbols
Authors: Watzke J.
Published: March 2007

On a appelé déchristianisation une aliénation généralisée des pratiques de la religion institutionnelle. Il est deplorable que l'histoire interprète ce phénomène comme un déclin de la religiosité et qu'elle appuye son point de vue sur des statistiques de diminution de pratique et d'insuffi sance doctrinale. Cette manière de voir est critiquée dans cet article parce qu'elle se base sur une conceptualisation de la religion sociologiquement inadéquate et parce qu'elle est incapable d'attirer l'attention sur le pro blème plus essentiel, à savoir l'échec des systèmes de symboles institution nels dans leur tentative de se brancher de manière valable sur le sens de la personne et de la culture, ce qui est l'essentiel pour l'individu contemporain.

L'engagement institutionnel et l'attention trop exclusive à l'élite de certains observateurs les a conduit à s'accommoder de cette tragique vision de l'histoire et à déprécier certaines formes d'expression religieuse. Leur défaut de percevoir la relation de l'expression religieuse à d'autres déter minantes de l'identité de l'individu est attribué à une deviation socio culturelle (classe et culture). L'auteur suggère que l'on constate à divers niveaux sociaux la dissociation entre sensibilité morale et 'religion', et qu'il existe une religiosité de base en dépit de l'incohérence de bien des éléments dans une religion institutionnelle. Des données rassemblées au Chili ont servi de point de départ à ces réflexions.

Cet article sert de base à l'élaboration d'une recherche sur la religiosité populaire que FERES va entreprendre en Amérique latine. Il pose le problème des relations avec les perspectives doctrinales et ethiques du développement.
Conflict over Charges of Heresy in American Protestant Seminaries
Authors: Adams Robert L.
Published: March 2007

Comment réagissent les séminaires protestants des Etats- Unis et du Canada face aux conduites d'hérésie et aux situa tions de conflit qui en résultent ?

L'étude porte sur quarante-trois cas d'accusations d'hérésie ayant eu lieu dans trente-trois séminaires différents. Ces sé minaires sont répartis en trois groupes selon qu'ils accusent un projet scientifique (university seminary), qu'ils se consacrent à la formation de militants (movement seminary) ou à la pré paration de pasteurs pour les Eglises (denominational semina ry). Cette dernière catégorie est elle-même subdivisée selon le caractère plus ou moins centralisé de l'autorité dans I'Eglise dont dépend le séminaire: organisation de type hiérarchique, de type fédéré ou de type congrégationaliste.

Parmi les séminaires relevant du troisième groupe (deno minational), l'hérésie a moins de chance de conduire à un éclatement interne lorsqu'il y a organisation de type hiérar chique.

Ce sont également les séminaires à organisation hiérarchique qui obtiennent les meilleurs résultats dans le contrôle des conflits résultant de l'hérésie et qui sont le plus à même de faire prévaloir la solidarité du groupe par l'éjection ou la sou mission du coupable.

Dans les confessions de petites dimensions, la solidarité joue dans le meme sens pour bloquer I'apparition d'un conflit, qui est d'autant plus préjudiciable lorsqu'il se forme dans une confession ne disposant que d'un seul séminaire. Les confes sions plus importantes, de type congrégationaliste, préservent leur solidarité en expulsant l'hérétique.

Ce sont l'université et les confessions pourvues d'une hiérarchie, qui assurent la meilleure protection aux idées théologiques nouvelles.
La sociologie de la religion d'inspiration marxiste en Yougoslavie
Authors: Orsolic Marco
Published: March 2007

Although the problems of religiosity were treated by a number of early Yugoslav ethnological and anthropo-geographical studies, such as those of V. Jagic, N. Nodilo and J. Cvijic, sociology in general and, more particularly, the sociology of religion is, in that country, an emergent science. The post-war development of the sociology of religion in Yugoslavia can be broken down into two phases. In the first ten or more years after the war the sociology of religion — if it can justifiably be called so — was dogmatic and vulgarly Marxian in its approach. Its exponents, notably O. Mandic, A. Fia mengo and V. Ribar, founded their critique of religion on assumptions bequeathed by positivism and the Enlightenment. Following Paul Holbach, Karl Kautsky and Soviet examples, they defended the simplified thesis that knowledge on the one hand and, on the other, the intervention of socialist society in existential socio-economic problems, will do away with the very foundations of religion and with religion itself.

More recently, a new approach has set in. It confronts. the body of knowledge and suppositions based on Marx's concepts with the result of empirical research. This stage in the development of the science is characterised by numerous en quiries into specific socio-religious problems which, in putting away empty theoretical constructs and exercises in pure, unimaginative empiricism, has achieved a more harmonious integration of theory and research results. This trend, represented mainly by Esad Cimic, Marko Kersevan and Zdenko Roter, undoubtedly holds great promise for the future.
Distinguishing Machines
Authors: Mukerji Chandra
Published: March 2007

The analyvsis in this paper suggests that when technology users define some kinds of machines as better than others for their work, they construct a scarcity of "good" equipment. This socialli' defined scarcity encourages users to struggle to get access to "good" equipment and to treat those with access to it as elites. To make this case the author uses participant observation data on film schools and student access to film-making equipment.
Qualitative and Quantitative Evaluation of Cotton Fabric Damage by Tumble Drying
Authors: Buisson Y.L. , Rajasekaran K. , French A.D. , Conrad D.C. , Roy P.S.
Published: March 2007

Abrasion and heat damage to desized and scoured cotton fabric during drying in a household tumble dryer are evaluated by SEM (scanning electron microscopy) and weight and tensile/strain tests for breaking strength and elongation. Wet fabric dried with heat shows severe fiber damage, and wet fabric tumbled at room temperature shows less damage than with heat. Dry fabric tumbled at a high temperature. equivalent to over- drying in a dryer, shows different but still severe damage compared to wet fabric. Moisture loss patterns during drying as a function of time or temperature indicate possible ways to minimize dryer damage by reducing unnecessary tumble-drying time and energy input.
Sorption Kinetics of Water Vapor in Wool Fibers: Evaluation of Diffusion Coefficients and Analysis of Integral Sorption
Authors: Nordon P. , Mackay B.H. , Downes J.G. , McMahon G.B.
Published: March 2007

A number of interval sorption experiments have been made and analyzed, assuming Fick's law; diffusion coefficients were derived. These coefficient have been used to predict the behavior in integral sorption; the disagreement between prediction and experiment is discussed. Integral sorption experiments have also been carried out on horse hairs of various diameters to trace the influence of diameter on the sorption rate.
The Tensile Properties of Twisted Single Fibers
Authors: Dent R.W. , Hearle J.W.S.
Published: March 2007

Single fibers were twisted to various amounts prior to tensile testing. The variations with twist in tenacity, breaking extension, modulus, and contraction or contractive stress on twisting have thus been measured. Experiments were carried out for both constant- tension and constant-length twisting; subsidiary experiments show the effect of other factors. The results are compared with those of other workers; explanations of them are offered.
Some Studies on the Cross-Linking of Cotton Cellulose
Authors: Perkerson Fred S. , Reeves Wilson A. , Tripp Verne W.
Published: March 2007

The currently-used types of cross-linking agents and some of their effects on cotton are discussed. The primary weaknesses or shortcomings of the finishes achieved with these agents are pointed out. It can be concluded either that the ideal cross-linking agent for cotton has not been found or that the best technique of application has not yet been discovered. However, considerable success is being had in producing minimum- care fabrics by the use of many cross-linking agents, especially the N-methylol type.

Although cross links through primary covalent bonds are largely responsible for the observed physical changes in cross-linked cotton fiber, secondary valence cross links also may produce significant changes, some of which appear to be rather durable. Evidence is presented which indicates that polymer formation produced concurrently with cross-linking improves the over-all minimum-care properties of cotton fabric, although polymer formation alone does not improve the wrinkle recovery. Cross-linking agents which are capable of forming thermosetting resins generally are required in somewhat larger add-ons to produce wrinkle recovery angles in the practical range than are those agents that do not form thermosetting resins. The extent of permanent set is related to the extent of cross-linking. Moisture regain and density of the cross-linked cottons are more dependent upon the state of fiber swotting at the time of cross-linking than upon the extent of cross-linking.
Application of Microscopical Techniques to the Evaluation of Experimental Fibers
Authors: Botty Martin C. , Felton Clinton D. , Anderson Richard E.
Published: March 2007

Three experimental acrylic fibers were characterized by a variety of microscopical methods and by microradiography in order to correlate their microstructures with measured physical properties and to help explain certain test results. By establishntent of a relationship of optical appearances to physical properties for these fibers, future experimental fibers of similar composition could be evaluated and their behavior pre dicted by comparatively rapid optical methods.
The Role of Spiral Structure in Untreated and Treated Cottons
Authors: Orr Rollin S. , Burgis Albert W. , DeLuca Lloyd B. , Grant James N.
Published: March 2007

The untwisting of the spiral structure was observed as load was applied to the cotton fiber. Reversals are shown to be a vital structural feature which affects the twisting. A reversing spirality represents an idealized structure for obtaining optimum strength, elongation, and elastic recovery from the straight-chain molecules of cellulose. Friction between growth layers and fibrils in such a structure is suggested as a possible cause for permanent set, low intrinsic strength of highly oriented cotton, and the weak points near their reversals.

The spiral structure persists through mercerization even though tension is applied; however, the X-ray angle is reduced appreciably. The high alignment achieved by resin treatment of cotton while under tension causes a reduction in elongation and increase in strength from that of slack treatment. The high alignment in cotton resin-treated with tension persists through washing with a detergent in water. Differences between properties of cotton are reduced but not eliminated by mercerization and resin treatment.
Theoretical Aspects of Hook Removal at Drafting Operations
Authors: Merchant V.B.
Published: March 2007

'rhe present theory relates mainly to the effects of changes in draft distribution that lead to concentration of the total draft in fewer zones on the extent of removal of trailing and leading hooks. It is a further refinement of the theory presented in Part I of this paper, which merely indicated that the concentration of draft in fewer zones is likely to facilitate the removal of hooks. On the basis of the present theory it is concluded that (i) at any draft within a single drafting zone the decrease in the hook extent of trailing hooks is always more than the decrease in the hook extent of leading hooks, the disparity between the two increasing rapidly with increase in draft, and (ii) when a given total draft is concentrated in fewer zones the degree of removal of trailing hooks increases whereas that of leading hooks decreases. However the total hook removal (i.e., leading hook removal plus trailing hook removal) increases as the same total draft is concen- , trated in fewer drafting zones.
Studies in the Reaction of Formaldehyde with Unmodified, Modified, and Dyed Celluloses
Authors: Datye Keshav V.
Published: March 2007

The equilibrium reaction between formaldehyde and cotton cellulose has been studied at 30° ± 1° C using the technique described in Part I [4]. The reaction reaches equi librium within the reaction period (96 hr). The equilibrium reaction depends on the concentration of formaldehyde and calcium chloride and seems to be independent of the concentration of hydrogen chloride. The combined formaldehyde ( CF) value for cotton cellulose at saturation has been calculated, and corresponds to ca. 20% accessibility. It is found that the saturation CF value is the same, within experimental limits, as the saturation value of sorbed formaldehyde calculated from published data. It is concluded that the reaction is limited to the accessible fraction of the fiher substance and proceeds at the reactive secondary hydroxyl groups, with the initial formation of the methylol ether of cellulose, which then condenses with the less reactive secondary hydroxyl groups. water molecules being eliminated to form methylene ether. It appears that all the methylene ether linkages are only between the 2 and 3 carbon atoms of anhydroglucose units and are monomeric under the present reaction conditions.

The results of acid hydrolysis of cellulose by hydrogen chloride are included in support of the explanation put forward for some of the observations.
Effect of Fiber-Forming Conditions on the Microstructure of Acrylic Fiber
Authors: Takahashi Masao , Nukushina Yasuhiko , Kosugi Setsuko
Published: March 2007

Results on the microheterogeneity of polyacrylonitrile filaments obtained by the wet- spinning process are presented, and the effects of fiber-forming conditions, such as type of spinning bath, spinning temperature, drawing temperature, drawing ratio, and heat- treatment conditions, on the microstructure are discussed.

The microvoid content of filaments that are obtained by spinning into aqueous baths is in many cases markedly larger than the microvoid content of filaments obtained by spinning into nonaqueous baths. Reduced spinning and drawing bath temperatures are favorable to improved fiber microstructure. Drawing of filaments results in great im proyement of fiber microstructure. The temperature of heat treatment in the dry state has an important meaning for the formation of the internal microstructure. The heat treatment in the wet state markedly changed the internal microstructure of both water- swollen gel-like filaments and dried filaments.

A consideration of the relation between small-angle scattering power, which is a measure of the relative content of microvoids of colloidal dimensions, and the properties of the fiber, such as specific gravity, cross-sectional aspect, degree of water retention, and dyeability, leads to a better understanding of the meaning of the internal micro structure of acrylic fiber.
Influences of Fiber Properties on Yarn Twists
Authors: Weiss Louis C. , Tsoi RubyH. , Sands Jack E. , Grant James N.
Published: March 2007

The variation in the twist multiplier for maximum yarn strength in terms of the fiber properties of length. weight fineness, and uniformity of tenacity along bundle length is inferred from data based upon 15 1, 30, 1, and 40/1 yarns of a series of cottons having widely different fiber properties. The optimum twist multipliers that were calculated (1) from the above three fiber parameters (i.e., the tenacity-length uniformity hypothe sis); (ii) from the length and fineness, and (III) from the fiber length alone are com pared to the optimum twist multipliers detemined from the yarn tenacity vs twist curves. The tenacity-length uniformity hypothesis and the Sullivan theory are com pared by utilizing single cotton fiber properties. Considering all comparisons, the cor relation coefficients for theoretical to nommal values of optimum twist range from 0.64 to 0.96. Utilization in yarn twist of the ratio denoting uniformity of tenacity along bundle length in the tenacity-length uniformity hypothesis and of the ratio of single-fiber tenacity transfer in the Sullivan theory is illustrated.
The Fracture of Wool Fibers
Authors: Mason P.
Published: March 2007

Stress-strain curves up to the breaking point have been obtained for wook fibers under the following conditions: in water at 0°, 20°, 50°, and 100° C; at 20° C at 0%, 65%, and 100% RH; immersed (from 65% RH) in liquid nitrogen. Measurements were made under each set of conditions at rates of extension of 5%/mm and 500%/mm. Tests were also carried out on medullated fibers and on fibers with notches cut in the side. In water the tensile strength decreased with increasing temperature or with decreas ing rate of extension; the extensibility varied inversely with the tensile strength. At 20° C the effects of increasing the humidity were generally equivalent to increasing the temperature or decreasing the rate of exteasion. In these tests the tensile strength ranged from 3 × 108 to 2 X 10 9 dynes/cm2, and the extensibility from 36% to 84%. The slopes of each of the three regions of the force-extension curve (Hookean, yield, and post-yield) all varied with temperature, humidity, and rate of extension, although the variation in slope of the post-yield region with humidity was small. The range of moduli observed was from 1.1 × 1010 to 3.9 × 1010 dynes cm2 in the Hookean region ; from 0.19 × 108 to 17.5 × 108 dynes/cm2 in the yield region ; and from 1.2 × 109 to 4.8 × 109 dynes/cm2 in the post-yield region.

The fibers tested in liquid nitrogen behaved like glassy polymers with an extensibility of about 2.5%, a tensile strength of 2.3 × 109 dynes cm2, and an initial Young's modulus approaching 1011 dynes/cm2.

Medullated fibers and tibers notched to a depth of as much as one-third of the fiber diameter showed surprisingly little reduction in strength. This is taken as an mdica tion of the presence of a few serious flaws in "normal" fibers.
Investigation into the Presence of Ozone in Cotton Spinning Milts
Authors: Wanner H.U. , Grandjean E.
Published: March 2007

Systematic investigations of ozone, nitrogen dioxide, and sulfur dioxide concentrations in the air of various cotton spinning mills have shown that within the buildings none of these are present in ahnormal concentrations. The cracks occasionally noticed on top roller cots and aprons made of material containing rubber or of synthetic material can not, therefore, be attributed to increased ozone concentrations.
Reaction Spinning of Polymethylmethacrylate Fibers
Authors: Fok Siu Yuen , Mickles Richard A. , Griskey Richard G.
Published: March 2007

The reaction spinning of polymethylmethacrylate fibers was studied. Measurements of fiber molecular weight were made for samples taken at various extrusion rates, column heights and temperatures. It was found that chemical reaction appeared to be the domi nant rate process in forming the fibers of the present work. The experimental data , resembled independently determined polymerization studies of polymethylmethacrylate.
Three-Dimensional Analysis of a Plain Knitted Fabric Subjected to Biaxial Stresses1
Authors: Whitney J.M. , Epting J.L.
Published: March 2007

This paper presents a three-dimensional mathematical model which describes a plain knitted fahric subjected to biaxial stresses. A relationship is established between ap plied stresses and fabric deformation through geometric parameters of the fabric structure. Consideration is also given to jamming of the yarns, which prevents further defornmation through the mechanism of loop slippage. Yarn extension and fabric rupture are also accounted for in the analysis.
Nonwoven Fabric Studies
Authors: Michie R.I.C.
Published: March 2007

A study has been made of the mechanical properties of viscose random-laid fabrics, saturation-bonded with at variety of commercial and experimental binder latices. There appears a rational pattern of behavior over all the materials investigated. Thus, fabric stiffness expressed either as initial modulus or bending length is uniquely related to rupture stress over a wide range of binder types and contents. The form of the relation ship indicates that, in a conventional saturation bonded fabric, stiffness cannot be significantly reduced without seriously impairing the strength.

Data obtained with binder films lead to the equation showing fabric modulus Ef to be proportional to binder modulus Eb in the low modulus region and independent of binder modulus in the high modulus region. A similar relationship has been found between fabric and binder rupture stress.

Binder uptake was found to be determined canly by liquor uptake, showing that there was no preferential absorption of either latex particles or of water. In general, fabric strength was linearly related to the amount of binder in the fabric. Variation in latex particle size within the limits 0.1 to 0.5 micron was without effect on the fabric properties.
Translation of Fibers and Yarns into Flexible Structures
Authors: Ross Jack H.
Published: March 2007

The translation of fibers into 'yarns and these into flexible woven forms has been undertaken, using a number of new and unique organic and inorganic fibers. The stranding and twisting of 0.0005-in.-diameter superalloy filaments has resulted in 'yarn. structures with superior flexibility and strength. The woven fabric of these yarns has 2 to 4 times more strength and 20 to 100 times greater fold endurance than fabrics woven of monofilament wires. The weaving of Beta-diameter fibers of E-glass compo sition into narrow webbings intended for decelerators has shown that the higher strength retention achieved after pressure and temperature is a function of its finer diameter, even when compared to fibers of S-glass composition. Investigation of the translation characteristics of high-temperature polymeric yarns has been conducted, utiliiing Nomex1 nylon. The high tninslation efficiencies obtained in weaving this yarn can be attributed to the unique stress-strain hehavior. The comparatively flat shape of the stress-strain curve in the post-yield region explains why little effect of geometry on the fabric strength is visible.
Spinning Performance and Yarn Properties of Cotton-Polyester Blends
Authors: Bargeron J.D. , Perkins H.H. , Mullikin R.A. , Ross J.E.
Published: March 2007

Cottons from the California, Memphis, New Mexico, and West Texas growth areas were blended with polyester staple to determine the effects of different cottons on the spinning performance and yarn quality of several blend levels. Combed 60's and carded 20's yarns were produced. For the combed study 65% cotton 35% polyester, 50% cotton—50% poly cster, and 35% cotton—65% polyester blends were processed. For the carded phase 100% cotton, 75% cotton—25% polyester, and 50% cotton—50% polyester blends were processed. The New Mexico cotton produced the best results in the combed phase. The California cotton produced better results than the Memphis cotton except for the 35% cotton— 65% polyester blend. A 1-in. West Texas cotton, a 29/32-in. West Texas cotton, a 1.50-in. polyester staple, and a 1.25-in. polyester staple were used i the carded study. The longer cotton produced the better results. The number of ends down decreased with the increased presence and length of the polyester staple. The longer polyester produced a superior yarn quality for the 50% cotton 50% polyester blend, but not for the 75% cotton 25% polyester blend.
Studies on the Ozone Fading of Anthraquinone Dyes on Nylon Fibers
Authors: Haylock J.C. , Rusie J.L.
Published: March 2007

A study has been made of the in service fading of a numher of blue anthraquinone dyes on nylon carpot yarns before and after heat setting. Samples were exposed to indoor and outdoor atmospheres in various parts of the U. S. A. The importance of the atmospheric humidity and temperature in the fading, suggested by laboratory testing, was confirmed. The laboratory test was shown to rank dye/fiber combinations in order of resistance to fading, and such a ranking was reproduced in the fading of samples exposed outside the houses. Inside the houses the laboratory ranking was less accu rate, illustrating the difficulties of using laboratory tests to predict the service life of a dyed nylon carpet.
The Dimensional Stability of Carpets in Installations
Authors: Gentry David R.
Published: March 2007

Dimensional stability of floor coverings to.forces encountered under end-use conditions has not been investigated extensively, although problems of wrinkling and puckering of carpets in stretch installations arise frequently. Changes in ambient humidity occur over broad ranges in most buildings; consequently, carpets which are not stable to changes in ambient humidity may be susceptible to puckering. A test procedure based on a method adopted by the British Standards Institution was used to characterize a large number of carpets for dimensional stability to changes in ambient humidity. Several carpet construction characteristics—total weight, pile yarn type, gage, and stitch density—were found to have little relationship to stability to humidity change. Large differences in stability were observed among manufacturers. Tufted carpets having jute backings were found to be less stable than carpets manufactured with synthetic backings.
End-Use Performance and Consumer Acceptance of Denim Fabrics Woven from Open-End and Ring-Spun Yarns
Authors: Morris M.A. , Prato H.H.
Published: March 2007

The performance of denim fabrics made from open end and ring spun yarns was compared ly a wear study and by aboratory measurements. For the wear study the fabrics were made into boys' jeans and were warn for a total of 26 wash/wear cycles. The results of both the laboratory tests and the wear study indicated that the ring spun fal ric was more durable than the open end fabric. However, the differences were small, and durability of both fabrics way accept able to consumers. Evaluation of the garments during the wear study was based on abrasion standards developed in the laboratory and the U. S. Army's General Equipment Test Activity system.
Estimation of Fiber Orientation and Length in Fiber Assemblies
Authors: Komori Takashi , Marishima Kunio
Published: March 2007

General formulas are derived for the estimation of fiber orientation and distribution in fiber assemblies whose constituent fibers are arbitrarily crimped. It is found that the density function of orientation can be estimated by solving an integral equation which relates it to the average numbers of fiber cross sections formed on the unit areas of randomly positioned and variously-oriented secant planes. The formula is:

ν(Θ, Φ) = L ∫π0 dθ ∫π 0 dϕ.1(θ, ϕ; Θ, Φ)Ω(θ. ϕ) sin θ ,

where L is the total length of the fibers in a unit volume, Ω(θ, ϕ) sin θ is the density function of fiber orientation, ν Θ, Φ is the areal density of the number of intersections formed by a secant plane with an orientation of (Θ, Φ), and 1 θ, ϕ; Θ,Φ is defined as | sin θ sin Θ cos(ϕ - Φ) + cosθ cos Φ. It is shown also that the total fiber length can be calculated by two methods.
The Dimensions of 1 X 1 Rib Fabrics
Authors: Poole Hardy B. , Brown Peter
Published: March 2007

Rib fabrics from cotton and cotton-blend yarns were treated to a variety of relaxation treatments. Cotton fabrics undergo greater wet relaxation shrinkage than synthetic fiber fabrics, while hot dry treatments have the opposite effect. Blends of cotton and synthetic fibers produce "u" values between high and low values of the 100% fabrics, while relaxation shrinkage is very fiber-sensitive. Consolidation shrinkage appears to be independent of the blend constitution of cotton polyester fabrics. Cotton rib fabrics attain similar "u" values to those reported for wool fabrics.
Heat and Mass Transfer During Steam Pressing of Wool Fabrics
Authors: Le C.V. , Ly N.G. , Postle R.
Published: March 2007

The temperature and humidity of steam and their effects on the absorption of moisture into wool fabrics during steam pressing are investigated. The temperature of buck steam in a steam press is greatly influenced by the temperature of the buck padding. The physics of heat and moisture transfer between the steam and the padding material is modeled to give predictions of the temperature and humidity of the steam entering the fabric. The calculated steam temperature confirms its dependence on the buck padding temperature, as does the steam relative humidity, which decreases steeply with prolonged steaming. A sharp increase in the fabric moisture content during the first few seconds of steaming is predicted by the model and confirmed by experimental measurements. Subsequent changes in moisture content as the fabric equilibrates to the steam condition will depend on the initial fabric regain and the steam condition. Variations in the temperature and humidity of steams between presses are explained as due mainly to the type and conditions of the padding. The model is also used to simulate vacuum cycles and can predict fabric temperature and regain during different cooling procedures.
Influence of Shade Depth on the Effectiveness of Selected Ultraviolet Absorbers in Reducing Fading
Authors: Rich Wendelin Marie , Crews Patricia Cox
Published: March 2007

This study evaluates the ability of seven ultraviolet (UV) absorbers to reduce fading of nylon colored with nine synthetic acid dyes applied at 0.5% and 0.05% owf con centrations. By including two concentrations, we could evaluate the influence of depth of shade on the absorbers' effectiveness. Specimens were treated with UV absorbers using one of two application methods: an exhaust bath at 100°C or an immersion treatment at room temperature. After treatment, specimens were exposed to 160 AFUs of light in a xenon-arc Weather-Ometer, then evaluated instrumentally to determine the amount of color change. The UV absorbers examined here provided only very limited beneficial effects. Only two had no detrimental effects on all dye/shade com binations to which they were applied, and their beneficial effects were limited to four to seven of the eighteen dye/shade combinations evaluated. Based on this research, we cannot make general recommendations regarding UV absorber use because some of the acid-dyed nylon specimens treated with UV absorbers exhibited no improvement in lightfastness, while other treated specimens actually exhibited greater fading or color change than their respective untreated controls. Further testing is needed to determine the effects of specific absorbers on specific dyes not examined in this study, because the effectiveness of each absorber appears to be dye and shade specific.