bluuebunny/crossref_metadata_2025 huggingface dataset:
The Stress Relaxation and Set of Wool Fibers with Particular Reference to Their Structure and Mechanical Properties-
Authors: Munakata Hideaki
Published: March 2007

The stress-strain relationship of wool fibers subjected to setting treatment has been investigated using a universal tensile tester. The amount of stress relaxation of wool fibers held strained in a setting medium varies in accordance with fiber stram, but these stresses reach a constant value with respect to fiber strain at the same duration of setting, and this stress value is almost constant over a wide range of setting conditions. The stress-relaxation process may be divided by this value into two stages : the first rapid relaxation of stress may be attributable to the noncrystalline regions of wool fibers, and the second stage to the crystalline regions. It is only at the second stage that the fiber begins to acquire a set.

The significance of the constant stress value is discussed in terms of a model of wool fiber and Flory's theory of elastic mechanisms in fibrous proteins. An attempt is made to explain the stress-strain curves and the setting mechanism of wool fibers using this model and the concept of helix-random coil equilibrium of α-helices in microfibrils.
The Human Factor in Projection Microscope Readings of Wool Fiber Diameter
Authors: Kritzinger C.C. , Linhart H. , van der Westhuyzen A.W.G.
Published: March 2007

It is known that, despite adherence to the rules governing the use of the projection microscope for fiber diameter readings, wide variations occur in the results from different laboratories as well as from different operators. A study has been made of the human factor in this method, using a total of eighteen well-trained female operators in different experiments. It has been found that the microscope or the slide, if used and prepared correctly, cannot account for the variations, but that some operators have significant constant and/or variable bias. It is shown that a correction, for example through read ing a "standard slide" for a variable bias, should preferably not be attempted, but that an operator having such a bias should rather be eliminated by prior tests.
Tensile Strength Distribution and Creep Failure of Cellulosic Filaments
Authors: Cheung Herbert C.
Published: March 2007

Measurements have been made of the lifetime under dead load and the tenacity of single fibers of five types of cellulosic varns. These yarns included a regular rayon, a rayon tire yarn, a high wet modulus rayon, a rayon produced by saponification of cellu lose acetate fiber, and a regular acetate. The logarithm of lifetime is shown to be a linear function of dead load. The tenacity distributions of four of the five fibers are found to be consistent with a static model based on the statisties of extremes, indicating that tensile fracture results from the presence of flaws. The regular rayon differs from the other four in that its tenacity histogram appears to have two modes.
Studies in Wool Yellowing
Authors: Milligan Brian , Tucker Daryl J.
Published: March 2007

The use of thiourea-formaldehyde resin for retarding the rate of yellow ing of wool by sunlight has been examined. This method provides considerable protection against yellowing, particularly of wet fabrics. It has been found that treatment with thiourea- formaldehyde mixtures. which does not give rise to resin, provides similar protection against yellowing. This modification has the advantages that the handle and color of the wool are unaffected, As for the resin treatment, initial rinsing reduces the pro tective effect, although this is not further reduced by subsequent washing.
Mechanics of Elastic Performance of Textile Materials
Authors: Freeston W. Denney , Platt Milton M.
Published: March 2007

Theoretical analyses of the effects of fiber diameter, fiber tensile and torsional stiff ness, fiber distribution and fabric density on the bending rigidity of nonwoven fabrics are presented. The fibers are assumed to exhibit linear tensile and shear stress-strain behavior. The two extreme cases of complete freedom and no freedom of relative fiber motion are analyzed.

A comparison is made between the predicted and experimentally observed bending rigidities of a waterlaid, nonwoven fabric composed of short, straight viscose rayon fibers.
A Comparative Study of Cross-Linked Kiered, Mercerized, and Decrystallized Cotton Yarns and Fabrics
Authors: Ziifle Hilda M. , Wade Clinton P. , Segal Leon
Published: March 2007

Kiered, slack-mercerized, tension-mercerized, and ethylamine-decrystallized cotton yarns, as well as 80 X 80 fabrics woven from these four modified yarns, were subjected to treatment with a melamine-formaldehyde finishing agent under varying conditions of tension during the drying and curing steps. The physical and mechanical properties of the cross-linked products were compared with those of the untreated control materials and with each other. Resin treatment produced similar effects upon the properties of - the decrystallized and those of the slack-mercerized yarns and fabrics. Tension applied during the drying and curing stages of the resin treatment affected the final properties of the finished product. In general, the greater the tension applied to yarns, the greater the retained breaking strength and elastic recovery but the less the elongation at break. Tension applied in this study dur-ing the drying and curing of the resin-treated fabrics adversely affected the elongation at break but was not sufficient to effect improvements in strength and recovery properties over those of similarly treated fabrics dried and cured under slack conditions.
Rate-Dependent Response of Polymers to Tensile Impact
Authors: Pilsworth Malcolm N. , Hoge Harold J.
Published: March 2007

A strain-rate-independent theory is shown to be inadequate to describe the response of polymers to tensile impact. A nylon yarn and a rubber strip were subjected to longi tudinal impact at velocities up to 100 m sec-1 and the resulting strains observed pho tographically. Rate-independent theory is used to calculate the expected results. Fundamental differences are noted between the observed and the calculated response. Particularly noted is the absence, in the observations, of shock waves that are predicted by the rate-independent theory.

A technique is described for loading a sample at uniform intervals along its length, and thus increasing the strain level reached before the resulting strain wave is reflected, even though the impact velocity is limited. This technique is used to determine a critical velocity for nylon yarn. Critical velocities calculated by a method based on rate- independent theory do not agree with this determination.
Survey of Cotton Fiber Swelling in Various Liquids by Use of the Yarn Untwisting Test
Authors: Porter Blanche R. , Orr Rollin S.
Published: March 2007

The relative swelling of cotton in 67 organic liquids and aqueous solutions of 14 inorganic compounds was evaluated by observing the number of revolutions of a singles yarn of Iquitos variety during untwisting in a 3-min post-immersion interval. Aqueous dilutions of the lower alcohols, two organic acids, acetone, and ethanolamine were also tested. The yarn was used in the unpurified state, after scouring and after scouring and mercerization. The relative swelling of cotton in 17 of the liquids determined by this untwisting technique was in qualitative agreement with values found by microscopi cal measurements of changes in width of fibers taken from the scoured and mercerized yarn. Qualitative agreement with values reported in the literature for measurement of swelling by other techniques was also established. The effects of some experimental variables wrere investigated.
Correlation of Visual Luster with Measured Reflectance of Cotton Fabrics
Authors: Ward Truman L. , Benerito Ruth R.
Published: March 2007

A group of 20 white fabrics and 12 blue fabrics, that were carefully constructed from specially prepared cotton yarns to produce fabrics of varying degrees of luster were used in this study. Some of each group were chemically modified with dimethylolethyleneurea and some of these resin-treated fabrics were calendered to produce fabrics of high luster. These fabrics were rated by a panel and the consensus of visual luster rankings was compared with ranking of luster obtained by measurements of specular and disuse re flectances. Reflectances were measured with both the Photovolt Reflection and Glossmeter and the Farrand Spectrofluorometer modified as a reflectometer. The latter instrument was used to hieasure reflectance of both polarized and unpolarized light. Consideration has been given to angle of incidence and reflectance, peak intensities, areas under re flectance curves, depolarization techniques, size of sample irradiated, and treatment of combinations of specular and diffuse reflectance data in the correlation of measured luster and visual luster indices. Use of polarized light was slightly advantageous when used with blue fabrics. While various treatments of reflectance data obtained with both instruments yielded agreement of approximately 75% between instrument and panel con sensus, the best correlation (82%) was obtained by ranking fabrics according to the ratio of specular to diffuse reflectances as measured with the Photovolt instrument.
The Vapor-Phase Dyeing of Cellulose Acetate
Authors: Jones F. , Seddon R.
Published: March 2007

The rates of absorption of saturated and unsaturated vapors of some model com pounds and disperse dyes by secondary cellulose acetate film have been determined. Initial and integral diffusion coefficients for both types of system and the activation energy of diffusion of azobenzene have been calculated. Low initial rates of absorption from saturated vapor are attributed to a time-dependent surface concentration. Extrap olation of diffusion data for two disperse dyes to higher temperatures gives times of half-dyeing of the same order as those observed in dyeing by dry-heat fixation methods.
The Wrinkle Recovery Properties of Acethydrazide Disulfide-Crossr-Linked Dialdehyde and Dialcohol Cottons
Authors: Hobart Stanley R. , Mack Charles H. , Wade Clinton P.
Published: March 2007

Disulfide-containing cross-links have been introduced into cotton fabric via the dialdehyde derivative. Periodate-oxidized (dialdehyde) cotton. was reacted in an aqueous system under mild conditions with acethydrazide disulfide, H2NNHCOCH2S- SCH2CONHNH2, giving a product of high wrinkle recovery (wet and dry). Sodium borobydride reduced excess dialdehyde groups and ruptured the disulfide cross-links. , Low wet wrinkle recoveries of the reduced samples are cited as evidence for cross link rupture. However, low dry wrinkle recoveries could not be demonstrated for the reduced fabrics due to the facile air-oxidation of the mercapto groups to reform the disulfide cross-links. Although air oxidation appears to occur readily, the moderately high wrinkle recoveries obtained indicate that the number of cross-links reformed falls short of the number originally present. The sulfur contents before and after reduction of the acethydrazide disulfide-treated samples were used to approximate the relative amounts which were reacted monofunctionally (thus parrially lost on reduction) and difunctionally (forming cross links). Syntheses of accthydrazide disulfide are described.
The Measurement of Regain of Wool by Electrical Capacity Type Moisture Meters
Authors: Algie J.E.
Published: March 2007

Ten samples of wool top from different mills have been examined for their dielec tric properties at 21 °C and frequencies from 180 c/see to 1.6 Me/see. A good correla tion was found between the content of water-soluble material and the regain error which would be indicated by a dielectric moisture meter calibrated for an average top. The range of this regain error at 1.6 Me/see was ±1% at 20% regain. An analysis has been made of the combined effect of several factors on the possible accuracy of dielec tric moisture meters.
The Influence of Hooked Fibers on Cotton Comber Waste
Authors: Belin R.E. , Taylor D.S.
Published: March 2007

If has been shown that a crossover exists in the percent waste versus gauge setting curves and this has been explained in terms of the breakage and the reduction in effec tive length of the fibers due to the presence of hooks.
Interactions of Nonaqueous Solvents with Textile Fibers
Authors: Weigmann H.-D. , Scott M.G. , Ribnick A.S.
Published: March 2007

An investigation of the effects of prior heat treatments on the stabilization of the polyester structure towards subsequent treatments with dimethylformamide (DMF) has been carried out. The results indicate that a DMF treatment at 140°C can overcome changes in the polyester structure produced by prior heat treatment up to a temperature of about 180°C. Void formation and accompanying high dye uptake under atmospheric dyeing conditions are observed. Heat treatments around 200°C, however, stabilize the fiber structure, and subsequent solvent treatments do not produce irreversible swelling and void formation. A further increase in the heat-treatment temperature again permits void formation and high dye-uptake values to occur. A close correlation between dyeability and void volume calculated from density data is observed.

A DMF treatment of a false-twist-set textured yarn leads to void formation and high dyeability, even though the heater temperatures used in the texturing process are near the critical temperature range at which stabilization to sub sequent solvent treatments has been observed. Evidence is presented suggesting that the yarns do not actually experience the temperature of the heaters but rather a significantly lower temperature.
Maturity and Dynamic Elastic Modulus of Cotton Fibers
Authors: Woo J.L. , Postle R.
Published: March 2007

The polarized-light method was used to select mature and immature individual fibers from each of four maturity standard cotton samples. The dynamic elastic modulus, or the sonic modulus, of the selected fibers was determined by the pulse-propagation method at different static strain levels, and continuous dynamic modulus-strain curves and dynamic stress-strain curves were obtained for each fiber type. In general, the maturity of individual cotton fibers influences the general shape of the dynamic modulus-strain curves in two ways: the curve is shifted to the left along the strain axis, and the initial slope becomes steeper as the fiber maturity becomes greater. Recognition of the variation in helix angle through the fiber cross section provided a satisfactory explanation for the experimentally obtained facts. Individual fibers of relatively high maturity were characterized by a high initial slope of the dynamic modulus-strain curve.
Polymerization-Crosslinking of N-Methylolacrylamide in Cotton Fabric
Authors: Rowland Stanley P. , Blouin Florine A. , Mason John S.
Published: March 2007

Several variations of polymerization-crosslinking of N-methylolacrylamide (NMA) in cotton were explored to clarify factors critical to achievement of resilience with superior retentions of strength and abrasion resistance in fabric. Per sulfate catalysis simultaneously initiated both polymerization and crosslinking reactions of NMA in cotton fabric; the results from dry-cure reactions fell in the conventional range of textile performance properties achieved by treatment of cotton fabric with agents such as dimethyloldihydroxyethyleneurea. Wet-cure reactions carried out in scaled bags at or above 100°C resulted in low resilience, high retentions of strength-abrasion resistance, and large increases in stiffness, the last attributed to fiber bonding in yarns. Wet-cure reactions conducted at or below 80°C caused little stiffness, and only in these cases was a subsequent catalyzed dry-cure reaction effective in raising resilience with good retentions of strength and abrasion resistance. Inclusion of alkali metal phosphates in the persulfate-initiated reaction of NMA with cotton in a pad-dry-cure caused retentions of abrasion resistance to be very substantially improved and retentions in breaking and tearing strengths to be significantly improved at durable-press appearance ratings of 4.5. These results are attributed to relatively sequential but rapid polymerization and crosslinking reactions, to reduction in formation of oxymethylene crosslinks, and possibly to reduced molccular degradation of the cellulose.
Adsorption of Polyacrylate Latex on Wool
Authors: Feldtman H.D. , Fleischfresser B.E.
Published: March 2007

The adsorption of a polyacrylate emulsion, Primal K-3, onto wool fibers, promoted by a water soluble, cationic polymer, Hercosett 57, has been studied under various conditions of pH and temperature. Adsorption was observed only under conditions where the latex coagulated, and then only when the latex particles and the fibers were not similarly charged. Depending on the pH of the system and the concentration of the cationic polymer, negatively-charged latex particles could be adsorbed onto positively-charged fibers and vice versa. Measurements of electrophoretic mobility indicated that the main function of the cationic polymer was to destabilize the emulsion by neutralizing the charge on the particles
Factors Influencing the Exact Replication of Double-Knit Fabrics
Authors: Little T.J.
Published: March 2007

Altering settings such as take down tension, stretcher board width, dial height, and stretch cam setting on a commer cially available knitting machine can cause substantial variation in the dimensions of double knit fabrics in the mac hine and dry-related state. Although subsequent relaxation reduces the magnitude of the effets, many romain statistically significant after wetting out and tumble drying. Knitting machine settings other than run in and run in ratio must be clearly specined if exact replicates of wool fabrics are to be obtained at a later date. The results also suggest that a com bination of settings could be derived such that subsequent relaxation shrinkage might also be reduced.
Factors Influencing the Exact Replication of Double-Knit Fabrics Part II: Textured Polyester Fabrics
Authors: Little T.J. , Leaf G.A.V. , Knapton J.J.F.
Published: March 2007

Changes in the dimensions of double-knit fabrics from textured-polyester fabric can be caused by altering knitting machine settings other than run-in and run-in-ratio. The machine settings studied which are responsible for the majority of the variation in dimensions are the take-down tension, stretcher-board width, and the yarn tension before the positive feed system.

The effects of altering the machine settings remain statistically significant in unset fabric, even after a severe relaxation treatment and a heat-setting treatment under controlled conditions is required to further reduce their magnitude. Re laxation of the fabric before heat-setting reduces the magnitude of the effects more than a heat-setting treatment alone. Other important aspects of finishing textured-polyester fabric are the level of fabric extension during setting and the temperature of washing used to assess the dimensional stability.
Weft Insertion by Water Jet
Authors: Kimura Satoo , Iemoto Yoshiyuki
Published: March 2007

In order to make clear a mechanism of weft yarn insertion in a water-jet loom, the flow velocity of the jet, the static pressure on the weft surface, and the driving force acting on the weft in the vicinity of the nozzle exit have been analyzed by utilizing the matched asymptotic expansion technique on the basis of results of the authors' previous paper. The present results are as follows. The flow of jet near the weft surface is perturbed by using the small parameter (the reciprocal of the square root of the Reynolds number). The flow velocity of the jet near the weft surface gradually decelerates, and hence the driving force acting on the weft gradually decreases. The static pressure on the weft surface of the jet portion rapidly decreases to atmospheric pressure.
Applying Microscopy to the Development of a Reference Method for Cotton Fiber Maturity
Authors: Boylston Eileen K. , Thibodeaux Devron P. , Evans Janice P.
Published: March 2007

Two microscopic methods for characterizing the maturity of a cotton sample have been developed, using either cross-sectional or longitudinal scanning of fibers by image analysis. This study compares the two methods for consistency with the aim of opti mizing their efficiency and accuracy as reference methods. Longitudinal scans of cotton fibers at immature (3.5 weeks post-anthesis) and mature (7 weeks, field opened) growth stages are compared with cross-sectional measurements of the same fiber samples. Maximum projections along the length of cotton fibers agree with cross-sectional mea surements, but minimum projections do not. Variations in fiber twisting and folding render minimum width projections inaccurate. The only true measure of wall thickness is from cross-sectional data, and fiber alignment is critical. Sample preparation for developing a reference method dictates that bundles of combed, parallel fibers be sectioned in the center. This procedure will decrease errors in sampling due to the natural taper of the fiber along its length.
Structure and Properties of Aromatic Polyamide and Polyimide Fibers Commercially Available in the Former USSR
Authors: Duobinis N.
Published: March 2007

This paper presents information about the trade names, structures, properties, and applications of aromatic polyamide and polyimide fibers and yarns produced in the former Soviet Union. Standard specification requirements for all commercially avail able fibers, yarns, and tows are presented.
Solvent Texturing of Polyester Yarn
Authors: Hashemi-Pour M. , Lee H.S. , Tucker P.A. , Cates D.M.
Published: March 2007

Solvent texturing experiments are described using partially oriented polyester yarn treated in sequential steps of twisting, solvent setting, and untwisting. Effects of several parameters such as solvent treatment time, pre-immersion solvent, and drawing on the shrinkage values are discussed. Pre-immersion in the solvent before twisting allows faster diffusion into the yarn but "sets" the structure prematurely. Drawing of the twisted, solvent-set structure dilutes the twist and disrupts the structure, reducing the crimp. The potential energy saving over heat-texturing is calculated. This study is intended as a precursor for continuous solvent texturing.
Cohesive Setting of Wool in Air: Effect of Mechanical De-ageing
Authors: Huson M.G.
Published: March 2007

Wool fibers that have been de-aged by water, heat, or tensile strain are shown to - cohesively set in bending more readily than aged fibers. By imposing strains of up to 25%, mechanical de-ageing of wool fibers leads to a temporary reduction in tensile modulus and yield stress, some cohesive linear set, and an increased ability to be cohesively set in bending. The extent to which the wool can be cohesively set in bending is a function of the level of de-ageing strain, the time of setting in the deformed shape, and the conditioning time prior to setting.
Dynamic Mechanical Properties of Carpet Yarns and Carpet Performance
Authors: Grover G. , Zhu S. , Twilley I.C.
Published: March 2007

Dynamic mechanical properties of commercial nylon, polyester and polypropylene carpet yarns are measured with a Rheovibron, and the tan δ] values are used as a measure of yarn resiliency. The effects of fiber drawing, fiber crimp, yarn structure, yam heat setting, and moisture on yarn resiliency and modulus as measured by the Rheovibron are investigated. In this exploratory study, dynamic mechanical mea surements on carpet pile yarns are compared with carpet appearance retention per formance. Rheovibron measurements of yarn resiliency may be related to carpet ap pearance retention during the initial stages of carpet walkout.
Mechanical Characterization and Behavior in Spinning Processing of Milkweed Fibers
Authors: Dréan Jean-Yves F. , Patry Jacinthe J. , Lombard Gérard F. , Weltrowski Marek
Published: March 2007

As part of a study of milkweed fibers, various blends of cotton and milkweed were created and the physical fiber and yam properties analyzed. The study included a unique investigation of transverse properties of wall thickness and linear density. Spin ning trials of blends with very high percentages of milkweed fibers revealed new data on specific problems with milkweed because of its smoothness and brittleness. These particular problems also prevented the manufacture of a pure milkweed yarn.
Crosslinking of Cotton Fabrics Premercerized with Different Alkalis
Authors: Chen Wen-Yeong , Liaw Ming-Yih , Lan Gwo-Wei , Chen Cheng-Chi
Published: March 2007

We have studied the dyeing kinetics of mercerized and mercerized and crosslinked cotton fabrics slack-mercerized with different alkalis. Regardless of whether or not the fabrics were treated with the crosslinking agent, the activation energies and the values of equilibrium adsorption for the various fabrics are ranked as follows: unmercenzed fabric > KOH mercerized fabric > NaOH mercerized fabric > LiOH mercerized fabric. However, the order of the rate constants and the structural diffusion resistance constants for the various cottons is LiOH mercerized fabric > NaOH mercerized fabric > KOH mercerized fabric > unmercerized fabric.
Crosslinking of Cotton Fabrics Premercerized with Different Alkalis
Authors: Jang Tyng-Ruey , Sheu Tzyh-Chyang , Sheu Jer-Jia , Chen Cheng-Chi
Published: March 2007

We studied the properties of cotton fabric samples premercerized with three kinds of alkalis and crosslinked with varying DMDHEU concentrations in the finishing bath. At a given nitrogen content and number of crosslinks, the change in wet crease recovery angle of finished fabrics from various premercerizing solutions ranked in the order of LiOH mercerized fabric > NaOH mercerized fabric > KOH mercerized fabric > unmercerized fabric. However, changes in tensile strength and elongation of the finished fabrics for the various premercerized samples are ranked as KOH mer cerized fabric > NaOH mercerized fabric > LiOH mercerized fabric > unmercerized fabric for a given nitrogen content and number of crosslinks. The value of crosslink length for the various finished fabrics has the same order at a given number of crosslinks. Degrees of surface migration of the agent on the finished fabric surface with NaOH and KOH premercerizing are significant.
Mental Accounting and Saving Behavior
Authors: Xiao Jing‐jian , Olson Geraldine I.
Published: March 2007

This study examines the validity of the mental‐accounting concept. Three hierarchical mental accounts are conceptually identified, representing a continuum from most basic (ACCT1) to least basic (ACCT3) needs, and empirically formed. Families are hypothesized to have different marginal propensities to consume from different mental accounts, and two related hypotheses are developed. Using data from 1983 and 1986 Surveys of Consumer Finances, estimates of stock adjustment models indicate that all families at low‐, middle‐, and high‐income level adjusted their savings from real stocks to desirable stocks fastest in ACCT3 and slowest in ACCT1. In the middle‐income sample, results showed that savings in ACCT1 at the end of the previous period had the largest negative influence on changes in ACCT2 and ACCT3, and savings in ACCT3 had the least influence on changes in the other two accounts, over one period of time. These findings supported the hypotheses derived from the mental‐accounting assumption.
Expert Computer Systems In Tourism: Emerging Possibilities
Authors: Crouch Geoffrey I.
Published: March 2007

Expert systems are designed to cope with problems or decisions which conventional computer tools are unable to handle because the solution relies on the knowledge and inferential reasoning capabilities of human experts. Since expertise plays an important part in the activities of many sectors of the tourist industry, and because expert systemts are beginning to have an important impact on business generally, a preview of the potential impact of expert systems on tourism is opportune.
Patterns Of Tourist Expenditure And Types Of Vacation Across The Family Life Cycle
Authors: Lawson Rob
Published: March 2007

This study examined the relationship between the family life cycle and tourist behavior, and found that stages in the family life cycle are reflected in both the type of vacation taken and financial expenditure made. Social orientation of young singles is evident, as are constraints imposed by children. Vacation activities correlate with the age of adult members of the group. Data are presented for accommodation, travel, meals, tours, shopping and entertainment, and reveal strong and consistent patterns of use for market segmentation.
County-level Tourism Impact Assessment: A Case Study in Beaufort County, South Carolina
Authors: Uysal Muzaffer , Pomeroy Robert S. , Potts Thomas D.
Published: March 2007

South Carolina's coastal counties are experiencing tremendous changes in population and economic development as a result of growth in the tourist, recreation, and resort sectors. However, little is known about the overall impact of the tourism industry in detail at the county level. This study presents the results of the application of an economic impact model designed to provide insight into the benefits of various mixes of tourism products at a local level with special reference to Beaufort County, South Carolina.
A nation 'living in different places': Notes on the impossible work of purification in postcolonial Sri Lanka
Authors: Spencer Jonathan
Published: March 2007

The article explores the relationship between migration and the nation-state in Sri Lanka. In particular, it investigates the shifting political and moral responses to the movement of human populations in the colonial and postcolonial periods. From at least the mid- 19th century, migration was seen as something requiring active 'management' by colonial officials; with the emergence of mass politics in the 1930s, new rhetorics of national purity are invoked. Theoretically, the article makes two points. The first is to treat all kinds of movement-internal and external—as potentially a single phenomenon. The other is to treat the disparity between the ideal of a bounded and static national popu lation, and the inevitably messier reality of movement, as a necessary and inevitable feature of political modernity.
A case of capital-rich under- development: The paradoxical consequences of successful transnational entrepreneurship from Mirpur
Authors: Ballard Roger
Published: March 2007

No other district in Pakistan has seen a higher proportion of its population engage in transnational migration than Mirpur, and from nowhere else have a higher proportion of such migrants successfully established themselves in Britain. Yet despite the intensity of the trans-local linkages which have thereby been created, and the huge flow of remit tance capital into a district which otherwise occupies a thoroughly marginalised position on the global periphery, in no way has this served to stimulate any kind of sustainable pattern of economic development. This article sets out to place these developments in their appropriate historical, political, environmental, local and global contexts in an effort to establish how and why it is that the Mirpuris'otherwise sophisticated and suc cessful entrepreneurial capabilities have not led to more successful and sustainable outcomes in their home base. There are good reasons why the lessons that can be learned in Mirpur could well be applicable elsewhere.
Identities in motion: Social exchange networks and rural- urban migration in Bangladesh
Authors: Kuhn Randall
Published: March 2007

Expanding on work that demonstrates the importance of rural resources (land, manpower) on rural-urban migrant success in Bangladesh, the article incorporates the role of an expanding network of village-based social connections in perpetuating the flow of migration and ensuring migrant success. As kin groups, lineages, and entire villages shift from their home settings to major cities, identities that had little meaning in the local context are mobilised to create trust between past and future migrants. Identity- based migration opportunities function as a new source of capital in a society with severe constraints on formal credit and insurance markets, allowing small landholders to pre serve their livelihood in exchange for allegiance to an increasingly influential group of urban gatekeepers. This fluid notion of identity often bends to more traditional social and economic concerns, however, generating a network whose membership is determined as much by pre-existing social relationships, spatial proximity and resource holdings, as by a potential migrant's skills, honesty or effort. Thesefindings raise critical concerns over the inherent risks and social costs built into the rural-urban migration process.
Hierarchy, difference and the caste system: A study of rural Bihar
Authors: Sahay Gaurang R.
Published: March 2007

This article seeks to contribute to the conceptual understanding of caste in the light of field data collected from four villages of Bihar. Against the background of two major theoretical positions, the 'hierarchy' thesis and the 'difference'thesis, the article confirms the empirical validity of the 'difference' thesis by demonstrating that castes in these villages have their own ideologies, revealed mainly in diverse and discrete origin tales that contest their hierarchisation on a continuous vertical scale. This does not mean that castes do not hierarchise themselves in respect to one another, but that each caste has a discrete notion of caste hierarchy. Caste members are proud of their caste ideology, and it is this which gives salience to their identity. The phenomenon of caste conflict and struggle for power makes quite clear that castes operate in the villages as separate groups, independent of an all-encompassing caste hierarchy. This apart , there is no specific relationship between caste and occupation , calling into question attempts to hierarchise castes on the basis of occupation. This has implications for the prevailing understanding of the jajmani system.
'The Bedias are Rajputs': Caste consciousness of a marginal community
Authors: Agrawal Anuja
Published: March 2007

This article attempts to further the argument that caste hierarchies are subject to creative manipulation by those who inhabit the supposedly fixed slots. I provide detailed ethno graphic data on the Bedias of North India, a 'denotified' community which lives off the prostitution of its own women. The engagement in this occupation renders the Bedias very 'low' in general opinion. But the data regarding the beliefs and practices of the Bedias shows that the community redefines the non-marital relations of the women with men belonging to higher-ranking castes through recourse to upper-caste norms of patriliny and hypergamy in order to claim upper-caste origin and affiliation. In doing so the community rejects the social position which the broader society accords it.
From Craft to Art
Authors: Kealy Edward R.
Published: March 2007

The paper studies popular music as a production process and delineates the varieties of its social organization. It explores the problems endemic to the collaborative nature of the production process and examines in detail the job experiences of one collaborator in particular, the sound mixer, during a period when craft activities were being transformed into artistic activities.
Decision-Making and Organizational Effectiveness
Authors: Miller Jon
Published: March 2007

As a way of examining some of the underlying assumptions commonly made about participation in decision-making, data provided by 161 members of a white-collar organization were used to explore the relationship between the structure of influence and member's perceptions of personal and organizational effectiveness. Separate analyses were performed for super ordinates and subordinates. The results showed that being allowed to participate was related to perceptions of effectiveness for subordinates but that allowing participation was not related to perceptions of effectiveness for superordinates. For the latter group, only perceptions of centralization were useful as a predictor of perceived effectiveness. The findings cast doubt on some of the social-psychological reasoning underlying many theories of participation and indicate that differences in organizational position need to be accounted for in assessing the organizational consequences of participation.
Argentina and Peronism: Fragments of the Puzzle
Authors: Corradi Juan Eugenio
Published: March 2007

Juan Eugenio Corradi, the coordinator of this special issue on Argentina and Peron ism, synthesizes past and present developments in his home country. He looks particular ly at the role of agrarian and industrial classes and their internal differences in an effort to clarify the meaning of Peronism through historical periods. He links his analysis to the other essays herein to assist the reader in gaining a coherent and unifying perspective of the diverse themes and content. Juan Corradi teaches sociology at New York University.
The Economy: Liberation or Dependency?
Authors: Ramos Monica Peralta
Published: March 2007

Originally published in Spanish, this contribution attempts to elucidate basic ques tions such as: what is the concrete expression of dependency in Argentina today?, how does imperialism maintain its domination?, who are its local allies?, which forces are cap able of sustaining a struggle for liberation? Peralta Ramos characterizes Argentina as a country in which capitalist relations of production are dominant but which at the same time is thoroughly enmeshed in a network of dependency relations. This distinguishes her analysis from two opposite positions — one that reduces Argentine conflict to that of any capitalist society; the other stressing exclusively the neo-colonial nature of the economy and society. Peralta Ramos maintains that the pole of resistence against imperialism lies with the urban and rural masses, under the leadership of the industrial proletariat. She also holds that the most powerful sectors of the bourgeoisie have long tied their interests to American monopoly capital, while other sectors of the bourgeoisie have been displaced and subordinated. It is the latter that are now directing economic policy, however. Perón ism tries to modify the relationship of forces within the bourgeois camp in favor of nation al capital and the state. Such strategy, Peralta Ramos contends, cannot produce a signifi cant break with imperialism. That can only be the task of a class coalition in which the proletariat assumes the leadership. Her essay locates Peronism yesterday and today in a sequence of stages of capitalist accumulation under conditions of dependency. Her central thesis is that present objective conditions make it impossible for national liberation to take place without a socialist revolution. Mónica Peralta Ramos does research and teach es sociology in Buenos Aires. Her doctoral thesis, written at the Ecole Pratique des Hautes Etudes of Paris, has been published in Spanish under the title Etapas de acumulacion y alianzas de clases en la Argentina (1972). The translation is by Rosa Méndez Gonzalez of the University of California, Irvine.
Chain Conformation and Crystal Structure of Stereoregular Polydienes
Authors: Corradini P. , Allegra G.
Published: March 2007

The conformations of a molecule represent different spatial arrangements of the atoms in a molecule, with a given con stitution and configuration, that may anse by rotations about single bonds. The assignment of the conformation to a ma cromolecule in the crystalline state, therefore, consists in the specification of the internal rotation angles that characterize its molecular structure. The conformation of macromolecules in the crystalline state is dependent on their configuration. The prin ciples underlying the conformation of macromolecules in the crystalline state can be summarized by the so-called equiva lence and minimum conformational energy principles; the equiv alence principle may be stated in this way. Starting from the consideration that in linear crystalline polymers the axis of the macromolecule runs parallel to a crystallographic axis of the crystal, the chain must be built up by structural units that occupy geometrically equivalent positions with regard to that axis; however, they are not bound to be crystallographically equivalent.
Topologically Interpenetrating Polymeric Networks
Authors: Klempner D. , Frisch H.L. , Frisch K.C.
Published: March 2007

This article describes ways of producing interpenetrating poly meric networks (IPN's). Formation of IPN's is one method used in overcoming the difficulty in mixing chemically incompatible poly mers. One method of preparing IPN's is the sorption of liquid curable polymers by crosslinked polymer films, then curing the resultant swollen film. Another method involves simultaneous cross linking of the two chemically different polymers mixed in a single solution. Crosslink density gives a good measure of degree of interpenetration.
Unconventional Chemistry of Isocyanates
Authors: Ulrich Henri
Published: March 2007

This article focuses attention on new uses of isocyanates. m-Phenylenedisulfonyl diisocyanate has been synthesized by direct phosgenation of disulfonamide in presence of catalytic amount of n-butyl isocyanate. Urethanes thusly derived are color stable. A variety of temperature stable heterocyclic polymers have been synthesized by reacting diisocyanates with tetrafunctional mono mers, e.g. diphenylester of resorcinol dicarboxylic acid. Heat stable foams can also be produced by cyclotrimerization of di and poly isocyanates. Within the next ten years, tailor-made polymers for many new applications will be synthesized and diisocyanates will play an important role.
Experimental Study of the Flow of Highly Viscous Materials
Authors: H L.A.
Published: March 2007

An experimental apparatus was designed and fabricated to study the flow of highly viscous synthetic rubber material. The flow rate, pressure drop, and temperature rise of the material was monitored during flow through the test section. Viscous heating was found to generate a significant temperature rise. Density, thermal conductivity, heat capacity, and apparent viscosity measurements were made for the test material at various temperatures. The dependence of viscosity upon shear rate was also measured. At temperatures above 250° F, the material starts vulcanizing and the Mooney viscosity increases rapidly. This was also observed for flow in capillary tubes at elevated temperatures where dramatic pressure increases reflect curing of material during flow. The property measure ments are used to predict the flow curve with a mathematical model that considers temperature-dependent viscosity. Agreement with the experimentally determined flow curve is excellent.
Creep, Self Heating and Failure of Thermoplastics Under Pulsating Tensi Le Stress
Authors: Menges G. , Alf E.
Published: March 2007

Fatigue behaviour of plastics is discussed by means of creep curves and the phenomenon of self heating. Amorphous thermoplastics such as polymethyl methacrylate (PMMA) and rigid suspension polyvinyl chloride (S-PVC) and partially crystalline polypropylene (PP) are examples. In practice, the first formation of crazes and microcracks and their defor mation have to be taken as a limit for mechanical loading rather than the ultimate failure.
Reaction Injection Molding: Filling of a Rectangular Mold
Authors: Castro J.M. , Macosko C.W. , Critchfield F.E. , Steinle E.C. , Tackett L.P.
Published: March 2007

The present trend in fascia reaction injection molding is to ward larger, more complex parts and faster reacting systems. This has lead to short shot problems. To study this, slow motion movies were taken of filling and flow around objects in a transparent plaque mold with fascia type urethane formulations. Mold pressure and temperatures were recorded simultaneously. For fill times less than a characteristic reaction time, pres sures can be predicted assuming constant viscosity during filling. For filling times greater than the characteristic reaction time, weld lines and short shots can occur. Criteria for good filling based on the dimensional analysis of the flow field equations are developed. Flow front instability was ob served for high flow rates.
Emulsion Paint of Aromatic Petroleum Resin. I. Emulsification of Aromatic Petroleum Resin Solution in Water
Authors: Iwase Yoshiyuki
Published: March 2007

Industrial emulsification of an aromatic petroleum resin solu tion in bodied linseed oil was investigated using an emulsion inversion process. It was found that the preferred surfactant had the best match in solubility parameter between olefinic group and resin solution A slight variation was found in optimum H LB for emulsification, depending on the chemical family of surfactants chosen, but independent on resin molecular weight. The average particle size of the emulsion obtained showed an ordi nary tendency to be dependent on speed of agitation, rate of water addi tion, resin viscosity, and surfactant concentration.
Relative Toxicity of Gases From Overheating of Rubbers and Plastics
Authors: Hilado Carlos J. , Huttlinger Nancy V.
Published: March 2007

Rubber and plastic materials may produce toxic gases when overheated to the point of decomposition. This paper reviews and discusses the available data on the relative toxicity of these pyrolysis gases.
Naphthalene-1.5-Diisocyanate as a Building Block for High Performance Polyurethane Elastomers
Authors: Prolingheuer E.C. , Lindsey J.J. , Kleimann H.
Published: March 2007

For many years naphthalene-1.5-diisocyanate (NDI) has been used in the polyurethane elastomer VULKOLLAN. NDI differs from the widely used diphenylmethane diisocyanate (MDI) and tolulene diisocyanate (TDI) with regard to its rigid structure and high melting point, resulting in sig nificantly higher melting points of the corresponding NDI/glycol hard seg ments. Combined with special polyadipate diols and crosslinked with glycols, NDI has proven to be the key building block to ensure the high property profile of the VULKOLLAN elastomer system. The NDI elastomer combines the elasticity of an ether based material with the toughness of an ester based elastomer.
Effect of Frequency and Temperature on Dielectric Properties of Polypropylene at X-Band Microwave Region
Authors: Chaki Tapan K. , Khastgir Dipak K.
Published: March 2007

Dielectric behaviour of large-molecular weight, high density, sol vent insoluble, isotactic samples of polypropylene have been studied in the X-band microwave region as a function of frequency (8.4-10.835 GHz) at ambi ent temperature (30 ° C) and as a function of temperature ( —120 ° C to 160 ° C) at three different frequencies by the method of Smith and von Hippel as modified by Dakin and Works. The sample exhibits two types of dispersion/relaxation in the semilog frequency plots of ∈' and ∈". The lower frequency dispersion is asso ciated with the crystalline region of the polymer while the higher frequency dispersion is related to the amorphous region of the polymer. Percent relative dispersions and relaxation magnitudes are found to be small. The values of "a" factors corresponding to the two loss peaks are 0.023 and 0.031, respectively. The most probable relaxation times for the two relaxation processes have also been calculated. Three types of dispersions namely β, γ 1, and γ2 have been observed in the ∈" vs. temperature plots at three different frequencies. The av erage apparent energy of a polypropylene molecule associated with its induced dipoles has also been calculated. The average values of the intrinsic activation energy, ΔE', decreases with increase of frequency, changing from 2.764 to 0.886 kcal/mol in the specific frequency region used.