bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fatigue in Textile Fibers1
Authors: Lyons W. James 
Published: March 2007

The practical advantages of a knowledge of the appropriate lifetime distribution in fatigue research are pointed out. The logarithmic lifetimes of two sets of polyester specimens, one fatigued over a 47-day period at a constant force amplitude (CFA) of 11.5 g, the other over a shorter period at a CFA of 13.4 g, were judged to conform better to the Weilbull third-asymptotic distribution than to the normal distribution, on the basis of visual inspection. A decline of about a decade and a half in the average logarithmic lifetime resulted from the higher level of loading. Measurements of the deviations from visually fitted straight lines of observed logarithmic lifetimes of the polyester and a polyamide sample, plotted on Weibull and on normal probability coordinates, shows that the observed results conform better to the former distribution. This finding is confirmed when the analysis is applied to the deviations from a line located by the squares method. A series of tests, employing the same polyester, was undertaken to assess the feasibility of attempting to load specimens with force-amplitudes of improved uniformity on a gram-per-denier basis. The technique adopted was to match care fully the slightly scattered linear densities of fiber specimens with the constants of the individual springs on the machine. While, in the final test, the spread in the loading (g/den) had been reduced to 5%, no clearly detectable improvement was found in the uniformity of logarithmic lifetimes—the ultimate objective. The conclusion is that structural dif ferences among specimens so far over-ride small nonuniformity in loading as to make it unprofitable to give time-con suming attention to the latter. For fibers of the polyester sample fatigued at four successively increasing force-amplitudes, the lifetime data showed moderately good conformance to the cumultive-damage principle. Values of 0.79 and 0.75 for the sums of damage ratios were found, where simple theory calls, for unity; though a newer hypothesis predicts deviations. A plot of the results of several tests on the polyester sample shows a general, substantial decline in logarithmic life times with increases in the force-amplitude. The lifetimes of specimens of the aromatic polyamide sample were found to conform to a Weibull distribution and to have an average value and range comparing favorably with those of the polyester sample under relatively the same conditions.
All-Cotton Durable-Press Fabrics of High Strength from Slack-Mercerized, Partially Restretched Yarn
Authors: Murphy A.L. , Margavio M.F. , Welch C.M. 
Published: March 2007

The virtual elimination of break and tear strength losses in cotton sheeting during conventional pad-dry-cure treat ments with DMEU, formaldehyde, APO, and bis(2-hydroxyethyl) sulfone has been observed. At wrinkle recovery angles of 270-300° (W + F), the tearing and breaking strength retention, or the average of these, in yarn-mercerized fabric were often equal to the values for untreated unmercerized fabric. Yet the cross-linking of unmercerized fabric produced 33- 55% losses in breaking strength and 45-68% losses in tearing strength. Moreover the scoured fabrics, yarn-mercerized and unmercerized, were nearly identical in strength prior to cross-linking. The experimental fabrics, woven of yarn only partially restretched after slack-mercerization, possessed higher elongation when cross-linked than did unpretreated cross linked fabric. Since strength losses during cross-linking can be varied or nearly eliminated without changing the wrinkle resistance ob tained, strength losses and wrinkle recovery are evidently produced by separate and, in some cases, independent cross-link mechanisms. Work of others indicates strength and elongation losses in conventional cross-linking processes are due to the spiral structure of fibrillar windings in the secondary wall of the cotton fiber. The fibrils cannot unwind fully and equally under stress after being cross-linked. Present findings suggest conditioned wrinkle recovery, as imparted here, arises in more elementary structural units, such as cross-linked microfibrils, where tensioning has little effect. The possibility that a strength maximum can occur in cotton at optimal levels of cross-linking is re-examined, in view of evidence that swelling and tensioning pretreatments, as well as polymer inclusion during cross-linking, can alter the amount and type of cross-linking already present in cotton because of hydrogen-bonding and crystallinity.
Dynamic Mechanical Properties of Rhinoscerous Horn Keraton in the Frequency Range 2-20 KHz
Authors: Dunlop J.I. 
Published: March 2007

A method is described for measuring the elastic modulus and loss tangent of rhinoscerous horn keratin in the frequency range 2 20 kHz. The technique is based on the forced resonance of a composite made of a specimen of rhinoscerous horn keratin cemented between two matched aluminum bars. Modulus is determined from the resonant frequency and loss tangent from the band width. Elastic modulus was found to be 5.7 8.0 × 1010 dynes/cm2 along the fiber direction, and 3-4 × 1010 dynes cm2 at right angles to the fiber direction, for samples at 9% regain and room temperatures. Loss tangents were found to be 2-4 × 10-2 along the fiber direction and 3-6 × 10 2 at right angles to the fiber direction.
Preparation and Testing of a Local Polymer Composite Based on Urea-Formaldehyde as a Binder
Authors: Ghanem N.A. , Mohsen R. 
Published: March 2007

The goal of this work was to prepare a polymer composite from totally local materials that had good abrasive properties, reasonable compressive strength, and one that could be easily applied. A number of local composites based on urea-formaldehyde and using ammonium chloride as a hardener have been prepared. It was concluded that the % hardener depends on the temperature of application, while the cure time depends on the composite formulations. Suggested applications for these composites are flooring material for railways and building bricks.
Using Microprocessor-Based Technology to Enhance the Measurement and Documentation of TDI/MDI Exposures
Authors: McMahon R. 
Published: March 2007

The use of microprocessor-based technology significantly improves the sen sitivity and response speed of existing TDI/MDI detection systems while simultaneously providing the industrial hygienist, occupational health profes sional, or process engineer with greater flexibility in documenting exposure data. The Chemcassette photo-colorimetric detection system, long an industry stan dard for TDI/MDI monitoring, becomes even faster and more sensitive when coupled with a microprocessor-controlled sampling and data acquisition system. As a result, it can detect isocyanate concentrations well below both existing and proposed regulations while simultaneously documenting all pertinent exposure information.
Precocious reading acquisition: psycholinguistic development, IQ, and home background
Authors: Patel P.G. , Patterson P. 
Published: March 2007

One child in one hundred learns to read at home around the age of four. These children are an interesting population, particularly in relation to the different components of their psycholinguistic development and home background. Twenty such children from Ottawa, Canada were administered Woodcock Reading Mastery Tests, CIRCUS (a general language develop ment test), tests related to metalinguistic processing and WISC. Some relevant home background data were also collected. Results show that precocious reading acquisition in these preschoolers cannot be attributed to either intelligence or general language develop ment. Interestingly, these children who read fluently like older children performed badly on metalinguistic processing tasks. The total pattern of the findings on these children suggest that the poor scores on these tests could not be dismissed in terms of task difficulty. An attempt is made to relate the above results to the current scientific scholarship on the possible psycholinguistic deficits associated with failure in reading acquisition, especially involving metalinguistic abilities.
Divisionalization in the UK: Diversity, Size and the Devolution of Bargaining
Authors: Armstrong Peter , Marginson Paul , Edwards Paul , Purcell John 
Published: March 2007

Business historians and theorists of organization have portrayed the divisionalized (M-form) organization as a response to the problems posed by diversity and, to a lesser extent, size. Assuming a drift towards optimal forms of organization, this implies that there should be a cross-sectional association between diversity, size and the incidence of the divisionalized form. This paper presents data from a survey of large UK companies which is only partly consistent with these expectations. The more diverse companies tend to be organised either in the divisionalized or the holding company form, whilst there is no size effect in the sense that divisionalized companies tend to be larger than the rest. There are size effects, however, on particular aspects of divisionalization. First, companies with levels of organization intermediate between their business units and headquarters tend to be larger than those which do not. Second, amongst companies without intermediate levels, size is associated with the reporting against target of profitability at business-unit level. This suggests that the introduction of intermediate levels or profitability targets might be alternatives in the earlier stages of company growth. With the exception of earlier work by Marginson (1985, 1988), the possible relevance of the divisionalized structure to the control of labour has been ignored. Marginson found some evidence that the M-form organization was associated with a raising of the bargaining level to that of the division as a response to the plantlevel trade union strength during the 1960s and 1970s. In the present era of comparative trade-union weakness, this paper argues that the divisionalized structure offers a means of maintaining outline control of a devolved bargaining process which is able to adapt to local contingencies. Partly consistent with this expectation, our data show that the M-form company is associated with a devolution of pay bargaining to the level of the individual establishment, although this is also true of the H-form. Consistent with the argument from trade-union weakness, this is a relatively recent development. In M-form and H-form companies, devolved bargaining tends to be accompanied by genuine managerial autonomy on pay issues. In other forms of organization, establishment-level bargaining occurs within the framework of tight headquarters control, so that the devolution is more apparent than real.
Attitudes, Values and Organizational Culture: Disentangling the Concepts
Authors: Hofstede Geert 
Published: March 2007

Sentiments collected through paper-and-pencil surveys are often arbitrarily classified according to categories imposed by the researcher, such as attitudes, values, and manifestations of organizational culture. The question is, to what extent are such classifications supported by the distinctions that respondents make in their own minds? In this paper, distinctions between categories of sentiments are supported empirically from the results of an employee survey in a large Danish insurance company (n = 2,590). The 120 questions used were classified into attitudes, values, perceptions of organizational practices (for diagnosing organizational cultures), and demographics. Perceptions of organizational cultures were measured using an approach developed by the author and his colleagues in an earlier study across 20 Danish and Dutch organizational units. In the insurance company study, employee attitudes were found to be clearly distinct from employee values. Perceptions of organizational practices were unrelated to values, and only overlapped with attitudes where both dealt with communication. In the latter case, both can be seen as expressions of the organization's communication climate. Other perceptions of organizational practices did not form recognizable clusters at the level of individuals, but only at the level of organizational (sub)units.
A. Planning and Writing Supervised Correspondence Courses
Authors: Beales Ruth , Rowbotham Alice 
Published: March 2007

WE have established by now a valuable new educational tool, adaptable to a variety of uses. The next question, then, is: How do we use it? What must we do—how should we organize—to help it operate at maximum efficiency? Since supervised correspondence instruction is necessarily a matter of teamwork, we shall need to look at the role of the correspondence center in preparing instructional materials and in teaching the pupils; at the role of the local school in guiding the pupil's choices and supervising his work; and at the role of other state agencies from a legal and technical standpoint. 1Miss Vibella Martin, now Coordinator of Curriculum in the Tamalpais Union High School District, established the pattern used at California in the studybooks for civics, shorthand, and mathematics, developing appreciation and use of important ideas and skills, using the best in teaching methods and indicating opportunities for the applica tion of these basic ideas beyond the confines of the courses.
What Parents Think of Their Schools and What They Know About Them
Authors: Hines Vynce A. , Grobman Hulda 
Published: March 2007

The University of Florida-CPEA Project has had as its purpose the description of how principals work with others—parents, teachers, and pupils—and how variations in these working patterns have differential consequences in such phases of school operations as attitude of parents, human relations among pupils and teachers, teaching methods stressed by teachers, program development within schools, and pupil achievement. Claims for certain types of administrative behavior have been evaluated against consequences in practice and the evidence indicates thus far, that how the principal does his job does make a difference. This article is a report on a part of the results of this project. The November 1956 issue of THE BULLETIN contains another report on this project. It is entitled "What Makes a Good Principal?" With a supplementary grant from the Kellogg Foundation, a new study is underway to test. out the consequences of a program of leadership train ing embodying recent advances in personality theory, perception psy chology, group process, and leadership research findings to see whether or not the more effective behavior patterns which have been identified can be developed among a group of principals.
An Exploratory Psychology Course for Teenagers
Authors: Bryant Larry W. 
Published: March 2007

I am interested in taking psychology because I believe it would help me understand other people better and would help improve myself in the eyes of them. I think a course in psychology would be helpful to me because I plan to major in that line in college. This would be like a preparatory course for me. As for others, psychology would be helpful in the understanding of man's mind and his everyday problems and how to cope with them. I would like to take psychology in high school as I plan to major in mental hygiene when I attend college.
Four Key Issues in the 1969-70 School Integration Crisis
Authors: Cooper Charles R. 
Published: March 2007

This fall the mass media hailed desegregation achievements in the South as a possible break through and suggested, in one case, that "all but a few pockets of segregation" were being wiped out. But the picture was still confused by con flicting court rulings, ambiguous official state ments, and statistics that conceal more than they reveal. As the BULLETIN went to press, the U.S. Supreme Court was working on three key decisions that would soon be made public. Hopefully, they will clarify such questions as: How much mixing of black and white pupils must a district do to qualify as "desegregated"? Must there be a racial balance in every school in a district? Or can predominantly black schools be permitted in all-black neighborhoods? Is massive "cross-busing" of both black and white pupils required to overcome de facto segregation that results from racial housing patterns? In this article Mr. Cooper offers both analysis and opinion on the current integration crisis. The NASSP does not necessarily share his views and welcomes contrary opinions for publication in later issues of the BULLETIN.
Freedom of Speech and Its Relationship to Dissent
Authors: Haiman Franklyn S. 
Published: March 2007

Since time immemorial, teachers have com plained about student apathy, lack of motiva tion, lack of interest in serious social problems. At last students are "turned on." But their manner of expressing themselves turns off people in authority. If we are to save and improve what we have of the democratic process and improve society, says Mr. Haiman, we must find a way to capitalize on the new motivation of the young. He lists a number of essential preconditions, some of which may surprise you.
Reactions to The Reasonable Exercise of Authority
Authors: Ackerly Robert L. 
Published: March 2007

In this article the author of a widely used NASSP publication, The Reasonable Exercise of Authority, discusses some of the conclusions he has subsequently reached on this vital sub ject. In the next article, his son, an "activist" 14-year-old, comments on the same topic. These two articles introduce more detailed treatments of several aspects of the exercise of school authority in a period when all authority is being questioned.
Is There Any Hope for New York City Schools?
Authors: Griffith Francis 
Published: March 2007

In this article a professor of school administra tion who has taught in New York City for 40 years harshly condemns the quality of teaching in NYC public schools, once known for excel lence. Since 1961 the city's teachers have improved their salaries and working conditions under a series of favorable contracts won by the United Federation of Teachers. UFT President Albert Shanker was invited to respond to Mr. Griffith's allegations. Sandra Feldman, identified as a "Special Representa tive" at UFT headquarters, replied that "[The article] is so poor it does itself in and really is not worth a response." The Bulletin editors think otherwise, and invite knowledgeable New York City educators to comment on the accuracy of Mr. Griffith's generalizations.
The New Social Studies
Authors: Switzer Thomas J. 
Published: March 2007

The inquiry method is full of dynamite for the administrator. For example, in at least one case a project was halted because of negative community reactions. To cope with such reac tions, the administrator must know what is be ing taught, have a procedure for handling com plaints, and be prepared to support his teachers in their pursuit of academic excellence. There are many other problems, all touched upon here.
European Schools: Are They Perfect?
Authors: Hart Manley H. 
Published: March 2007

In July 1969 we left on a one year sabbatical trip to Europe. We were to visit 23 different countries and travel over 31,000 miles. It was a trip that took us within 200 miles of the Arctic Circle, south to Spain and Portugal, and east to Greece and Turkey. My wife, Mary, and Joanne and John, our children who were nine and seven at the time, accom panied me. We made our home for the year in a 16 foot English caravan (travel trailer) which traveled everywhere behind our car. Through the cooperation of the National Association of Secondary School Principals I set up a program of school visits in Belgium, England, Germany, Italy, the Netherlands, Norway, Scotland, Sweden, and Yugoslavia.
The Design of Flexible Robotic Manipulators with Optimal Arm Geometries Fabricated from Composite Laminates with Optimal Material Properties
Authors: Liao D.X. , Sung C.K. , Thompson B.S. 
Published: March 2007

The fabrication of lightweight robot arms in composite mate rials and the ability of robotic devices to dissipate residual vibrations at the termination of a maneuver have both been highlighted as key research problems in a recent report pub lished by the U.S. Congress, Office of Technology Assess ment. Both problems are addressed here. We develop a method for optimally configuring the geometry and the mate rial fabrication parameters of hollow box members for robo tic manipulators constructed with composite laminates. We do it by integrating a formulation for laminated beams with a recent approach for predicting the damping characteristics of laminates before incorporating this general theory into an optimization algorithm, which permits general constraint conditions to be imposed on the solution procedure. To illustrate the proposed design methodology, we give an example of an industrial manipulator with flexible links that describes three-dimensional motion. We make a comparative study of the initial robot and optimal designs to simulate the elastodynamic behavior of the end-effectors for a prescribed maneuver. The results of the finite element simulations clearly demonstrate the superior response of the proposed optimal design.
A Singular Perturbation Approach to Control of Lightweight Flexible Manipulators
Authors: Siciliano Bruno , Book Wayne J. 
Published: March 2007

The control of lightweight flexible manipulators is the focus of this work. Theflexible manipulator dynamics is derived on the basis of a Lagrangian-assumed modes method. The full-order flexible dynamic system does not allow the deter mination of a nonlinear feedback control as for rigid manipu lators, since there are not as many control inputs as output variables. This drawback is overcome by a model order reduction, based on a singular perturbation strategy, where the fast state variables are the elastic forces and their time derivatives. A composite control is adopted. First, a slow control is designed for the slow subsystem, which is shown to be the model of the equivalent rigid-link manipulator. Then a fast control is designed to stabilize the fast subsystem around the equilibrium trajectory set up by the slow subsystem under the effect of the slow control. The one-link flexible-arm prototype in the Flexible Auto mation Laboratory at Georgia Institute of Technology is chosen for developing a case study. Simulation results are illustrated, and a comparison is made between the perform ance achieved with a two-time-scale controller and with a state feedback regulator.