bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct Processing of Continuous Fibers onto Injection Molding Machines
Authors: Truckenmuller F.M. 
Published: March 2007

A new injection molding process "DIF" (Direct Incorporation of Con tinuous Fibers) is proposed whereby roving strands are directly incorporated into the polymer melt by using a reciprocating-screw-plasticating unit. The DIF-technology offers the possibility to substitute the relatively expensive pultrusion process which is used to produce long fiber pellets. Furthermore it can be used as a fast and flexible R&D tool. In order to improve fiber dispersion with minimum fiber breakage a new mixing non-return-valve" LFMR" ( Long Fiber Mixing Ring) was developed based on the " Twente Mixing Ring." Its mixing capacity and influence on processing charactenstics, fiber breakage and property profile of the injection molded parts is examined and compared to a general purpose non-return-valve of the ring type. The results of fundamental mechanical and physical property investigations are presented including dispersion of fiber clusters and bundles, fiber length distribution and fiber orientation.
Factors Affecting Surface Smoothness and the Role of Unsaturated Polyester Resin and Glass Fiber
Authors: Arakawa Kouji , Iwami Etsuji , Kimura Keiji , Nomaguchi Kanemasa 
Published: March 2007

This paper covers an investigation to determine the factors affecting sur face smoothness of SMC moldings. Many studies have been done at many laboratories to improve the surface smoothness quality of SMC moldings. These studies are aimed at comparison with steel sheets. This goal has almost been realized, resulting in better SMC formulations and molding process conditions. However, the authors could not get suffi cient results even with these better formulations and conditions because the surface smoothness values in the data did not show adequate consistency among the locations mea sured. In addition, they got various smoothness values in their moldings, even when using the same SMC production lot. The authors tried to solve this inconsistency problem by examining the effect of un saturated polyester resin/low profile additive and glass fiber as main factors in surface smoothness. They found substantial effects with actual limitation in surface smoothness that came from "compatibility" between unsaturated polyester resin and low profile addi tive, as well as the "fibrillation state" of chopped glass fibers.
Cellular Analysis of Ocular Circadian Pacemaker Coupling in Bulla: Role of Efferent Impulses in Phase Shifting
Authors: Block Gene D. , Roberts Michael H. , Lusska Amy E. 
Published: March 2007

The eyes of Bulla gouldiana, a marine snail, contain circadian oscillators that are coupled to each other. Obvious candidates for the coupling signals are the optic nerve compound action potentials (CAPs) that express the circadian rhythm and lead to efferent impulses in the contralateral optic nerve. In the present experiments, the role of the CAPs as coupling signals was evaluated. We found that, following desynchronization of the two ocular oscillators by phase-delaying one eye with manganese, subsequent phase shifts in the initially unshifted ocular rhythm only occurred during the time that efferent optic nerve signals were present. In addition, in the absence of ocular desynchrony, phase shifts of the ocular rhythm could still be effected by activation of the efferent pathway. The influence of efferent impulses on identified retinal cells was also evaluated. No effect of efferent signals on receptor layer cells was detected, while it was found that efferent impulses generated depolarizations in basal retinal neurons (BRNs), the putative circadian oscillator cells. Depolarization of the BRNs has been shown previously to be involved in the light entrainment pathway. Depolarization appears to be similarly involved in the coupling pathway, since membrane depolarizations that mimicked the efferent-induced postsynaptic potentials likewise generated phase shifts of the ocular rhythm.
Phase Shifts in the Circadian Rhythm in Plasma Concentrations of Melatonin in Rams Induced by a 1-Hour Light Pulse
Authors: Maeda K.-I. , Lincoln G.A. 
Published: March 2007

The effect of a 1-hr light pulse, given at night, on the timing of the circadian rhythm in the plasma concentration of melatonin was examined in Soay rams to investigate the mechanisms involved in determining the duration of the nocturnal peak in melatonin secretion. Animals (n = 8) were housed under short days (LD 8:16) or long days (LD 16:8) and received a light pulse at various times of night. They were released into constant dim red light (DD) on day 1. Blood samples were collected hourly for 30 hr from 1000 hr on day 3, and the plasma concentration of melatonin was determined by radioimmunoassay to assess the timing of the melatonin peak. Control animals (n = 8) were maintained under the same conditions but received no light pulse. Under short days, a light pulse given early in the night caused a phase delay in the melatonin peak, and a light pulse given in the late night caused a phase advance. The mean duration of the melatonin peak was slightly reduced following a light pulse in the early or late night, and slightly increased following a pulse given near the middle of the night. Under long days, both light-pulse treatments given at night caused a phase delay in the melatonin peak, but there was no significant change in duration of the melatonin peak. The duration of the melatonin peak at day 3 under DD in the control animals was similar for all treatments, regardless of the previous entraining photoperiod (mean duration: 12.6-14.8 hr) and was similar to that under short days (14.6 hr), but was significantly longer than that under long days (8.2 hr). Information on the phase response curve in the Soay ram and on the period of the circadian oscillator governing the melatonin rhythm (c 23.0 hr under DD) predicts a close phase relationship between the end of the light phase and the onset of the melatonin peak as observed under normal 24- hr LD cycles. The current results also indicate that light acts to entrain the circadian rhythm influencing the onset and offset of melatonin secretion, and thus dictates the duration of the melatonin peak.
Resistance, Persistence, and Change: the Transformation of the Catholic Church in Poland
Authors: Osa Maryjane 
Published: March 2007

Christian social doctrine... is a doctrine of the most important non-religious sociological structures which are erected upon independent foundation, or, to use its own language, of its relation with the most powerful social forces of the `world.' If we admit that the State and Society, together with innumerable other forces, are still the main formative powers of civilization, then the ultimate problem may be stated thus: How can the Church harmonize with these main forces in such a way that together they will form a unity of civilization? Ernst Troeltsch (1911)
Stress and Displacement Analysis of Composite Laminated Plates
Authors: Afshari P. , Widera G.E.O. 
Published: March 2007

Multilayered composite plates are of interest for a variety of structural ap plications in such industries as automotive and aerospace, where high strength-to-weight ratios are desirable. In this investigation a series of plate elements is developed for such structures. These plate elements are formulated based on a variational principle, namely modified complementary energy. Mindlin thin plate theory is selected to govern the gen eral characteristics and behavior of these plates. Transverse shear deformation is included in the formulation. A series of in-plane strain functions is assumed from which the corre sponding in-plane stresses for each lamina are determined. By satisfying the equilibrium equations, the transverse stresses are calculated. The strain parameters can be determined by satisfying the interlaminar transverse stress continuity and the traction-free condition at the bottom surface. The top traction-free condition is ignored in this formulation. It will be demonstrated that the impact of ignoring the top traction-free condition on the results is negligible. Eight-node isoparametric elements with five degrees of freedom per node are utilized to describe the displacement field. These elements are invariant, fast converging, and insen sitive to the number of gauss points used in the numerical integrations. Moreover, it will be shown that these elements do not exhibit any shear locking in the thin plate limit. These elements are capable of handling the effects of transverse shear deformation, extension- bending, twisting-extension, and twisting-bending coupling that exist due to the different orthotropic material properties of each layer. It will also be demonstrated that these ele ments are capable of adequately predicting the displacements and the stresses for a variety of composite plate problems.
Elite Interaction and Constitution Building in Consociational Democracies
Authors: Tsebelis George 
Published: March 2007

This paper uses game theory to provide a common framework to address three questions: (a) Under what conditions is it possible for political elites in segmented societies to pursue accommodating strategies? (b) If elites choose such strategies over long periods of time, why do their followers continue to vote for them? (c) How can political institutions promote accommodating behavior? The essence of the argument is that political elites perceive the political situation as a game of chicken, while the masses may see it as a prisoners' dilemma or deadlock. When elites take into account electoral considerations, a weighting scheme determines the nature of the composite game. This game need not be symmetric with respect to the ranking of payoffs of the different players. The framework explains not only the major independent variable of the consociational democracies literature concerning the accommodating behavior of elites, it explains one of the major criticisms against this literature as well: the phenomenon of elite-intitiated conflict. The same game theoretic framework is used to explain how Belgian institutions work.
Women's Identity in a Country in Rapid Social Change: The Case of Educated Black South African Women
Authors: van Vlaenderen Hilde , Cakwe Mandisa 
Published: March 2007

African societies are currently going through a period of accelerated social change, charac terised by increasing population, rapid urbanisation, high regional, national and inter national migration and the assimilation of western values. These changes are increasingly eroding the clear gender role divisions, characteristic of traditional African society, leaving women with a greater personal responsibility to develop their identities. This article focuses on the identity formation of a group of South African black women in a process of rapid social change. The study involved interviews with 10 black African professional women from a rural background. The data from the interviews were analysed using the grounded theory approach. The study revealed that the women's emergent identity was characterised by a strong feeling of independence as well as a commitment to their families. They largely rejected the traditional African gender roles and embraced an identity that encompassed both male and female roles in the family, taking upon them a heavy burden of responsibilities. In an attempt to find support and to valuate their newly emerging identities, they created a new reference group, consisting of like-minded women.
Productive Inertia and Technical Change
Authors: Bye Pascal 
Published: March 2007

How can we evaluate the direction and dynamics of technical change? Indicators or analyses are often based on the immediate causes such as innovation, investment in R&D, or on the anticipated effects such as improved competitiveness and creation of new products. Anxious to demonstrate the economic or social benefits, the forecast ing impact is often reduced to risky comparisons between these two sets of data. This recording of change takes into account only the immediate situation, that is, the short-term. But technical change is first and foremost the product of the long history of societies. The recording of variations, the introduction of variables considered as exogenous, even if it facilitates the introduction of rationality into the choice which presides over change, in no way enables us to understand its origins and the evolution. It is essential that we restore the dimension of time to technical change and to consider it as the product of contradictory forces. In this paper it is proposed that the relationship between changes and non-changes in techniques includes the idea of inertia. Although changes are manifest and justify the analyses which have been devoted to them, non-changes have rarely been taken into consideration. The role of inertia appears even more clearly when the rate of growth slows down, as social values are called into question, as price or regulatory systems are transformed. These considerations have an impact on the formulation of technological policies. They permit a redefinition of industrial innovation strategies in a context which should permit their social and economic insertion.
A Self-Sensing Piezoelectric Actuator for Collocated Control
Authors: Dosch Jeffrey J. , Inman Daniel J. , Garcia Ephrahim 
Published: March 2007

A technique has been developed which allows a single piece of piezoelec tric material to concurrently sense and actuate in a closed loop system. The motivation behind the technique is that such a self-sensing actuator will be truly collocated and has applications in active and intelligent structures, such as vibration suppression. A theoreti cal basis for the self-sensing actuator is given in terms of the electromechanical consti tutive equations for a piezoelectric material. In a practical implementation of the self- sensing actuator an electrical bridge circuit is used to measure strain. The bridge circuit is capable of measuring either strain or time rate of strain in the actuator. The usefulness of the proposed device was experimentally verified by actively damping the vibration in a cantilever beam. A single piezoceramic element bonded to the base of the beam functioned both as a distributed moment actuator and strain sensor. Using a rate feedback control law, the first mode of vibration was suppressed, reducing the settling from 35 seconds to 2.5 seconds. Using a positive position feedback law the first two modes of vibration were suppressed; the first mode settling time was reduced from 35 to 0.3 sec onds and the second mode settling time was reduced from 7 seconds to 0.9 seconds.
Kinematic Model of a Stick Insect as an Example of a Six-Legged Walking System
Authors: Müller- Wilm Uwe , Cruse Holk , Eltze Jürgen , Dean Jeffrey , Weidemann Hans-Jürgen , Pfeiffer Friederich 
Published: March 2007

The model proposed here describes the control of the leg movement of a six-legged walking system. It is based on biological data obtained from the stick insect. The model represents a combined treatment of realistic kinematics and of biologically motivated, adaptive gait generation. ln contrast to previous biologically motivated models, it includes realistic legs with three joints and natural geometry and, with some simplifying assumptions, describes the movement of the joints and the tarsi. The results show that the information obtained from biological experiments can be incorporated into a model for a six-legged system that is able to walk at different speeds over irregular surfaces. The model shows a stable gait even when the movement of the legs is disturbed. The system can start walking beginning from arbitrary starting positions of the legs. Thus, the control system described here can be used to control a real walking machine.
A Shared Multi-Media Design Environment for Concurrent Engineering over the Internet
Authors: Tay Francis E. H. , Chen Ming  
Published: March 2007

The Internet is currently an important resource for businesses to conduct activities ranging from basic communication to data exchange. In addition, the Internet is fast becoming an important portal for concurrent engineering applications. The Virtual Design Studio (VDS) presented in this paper is to construct a virtual design environment over the Internet in order to over come geographical constraints, and satisfy the major issues of concurrent engineering. Traditional design activities have been studied and implemented in the VDS to enable effective and efficient collaborative design. In addition, the proposed virtual design environment also supports both the product design and distributed communication tools used by designers. The aim of VDS is to integrate the exist ing information technologies (such as remote file transfer, multimedia and virtual reality among others) into the design process and to ex plore the possibility of extending collaborative design system over the Internet. This infrastructure will enable the establishment of distrib uted design offices in a global environment by means of the Internet. As such, collaborative design resources can be made readily available to industries, research institutions and educational institutions. CyberCAD is the application developed to support the realization of VDS. Remote file transfer and platform independence have been implemented in CyberCAD to enable the sharing of resources. CyberCAD provides a powerful collaborative CAD system running on a PC based platform. A multimedia communication enabled CAD conference module has been integrated into CyberCAD. Video and audio communications provide the collaborative multimedia environment, which overcome the geographical limitation in traditional "face to face" collaboration and enhances interaction between designers. Drag and drop method has been adopted in the proposed CAD conference module for re mote design information sharing.
Organization Structures, Concurrent Engineering, and Computerized Enterprise Integration
Authors: Jian Dong  
Published: March 2007

Great competition in the contemporary manufacturing industry has resulted in companies taking a close look at their production prac tices. Increasing needs for higher productivity and better product quality is forcing manufacturers to reevaluate their production philosophy, and improve their product and manufacturing processes. Quick and correct decision making during product and manufacturing process development is the key for a company's success. In this paper, following the discussion of organizational structures and Concurrent Engineering (CE) requirements, an object-oriented window-based (OOWB) information framework is introduced for enhancing concurrent engineering decision making and organization integration. This framework at tempts to seamlessly and transparently connect product design, acquisition, manufacturing process development, and other various life-cycle support activities. In the framework, each activity is considered as an object and represented by a window. The OOWB information system forms an integrated virtual manufacturing environment in a company.
Adjusting to Macro-Economic Reforms in Russia: The Crisis Case of the Svetogorsk Mills
Authors: Lilja Kari , Tainio Risto , Törnqvist Stig 
Published: March 2007

This article describes the transformation process of the Svetogorsk paper mills in 1988-1992 under conditions of perestroika, and the subsequent eco nomic reforms in the former Soviet Union. The study was carried out as a piece of action research, which means that crucial knowledge about the transformation was generated in the actual process of changing the produc tion and maintenance management of the mills. The decentralization of the planning system generated enthusiasm, opti mism and energy in the ranks of management. The results of the initial change efforts proved to be positive, and the most acute production prob lems were successfully resolved. But technical improvements and new main tenance practices were not enough. The instability and unpredictability of the institutional environment had destroyed the prerequisites for profitable business. The study provides some insight into the difficulties of organiza tional change under the conditions of a constantly changing environment and a weak internal resource base. It is a study of an organizational crisis under systemic collapse.
The unexplored void of ADHD and African-American research: A review of the literature
Authors: Samuel V.J. , Curtis S. , Thornell A. , George P. , Taylor A. , Brome D. Ridley , Biederman J. , Faraone S.V. 
Published: March 2007

Objective: To identify the body of knowledge exploring the subject of ADHD and African- Americans. Method: A systematic review of the literature was conducted through the Medline, Psychlit and Psychlnfo databases. Results: In contrast to thousands of articles on ADHD, only 16 articles were identified that dealt with ADHD in African-American youth. Additionally, only a handful of these articles had ethnicity as the primary focus of research. Studies that examined ADHD among African-Americans in a school context showed that race may affect how teachers diagnose hyperactivity. Treatment studies suggested that African-Americans may respond similarly to the same ADHD medications as do Caucasians. Studies evaluating ADHD assessment tools were so sparse that they were largely inconclusive. Discussion: The paucity of studies on the subject of ADHD and African-Americans suggests the urgent need for more research to be done in this area. Such studies should be based on culturally sensitive designs.
Comparison of Thermal Performance of Wood Stud and Metal Frame Wall Systems
Authors: Kosny Jan 
Published: March 2007

A series of two- and three-dimensional computer simulations was conducted for several wood stud and metal frame walls. The HEATING 7.2, finite difference computer code developed at Oak Ridge National Laboratory (ORNL), was used to model walls and their components. Eight wood stud and eight metal frame walls were modeled. Several levels of exterior insulation and stud spacing dis tances were considered to compare clear walls thermal performance. R-value reduc tions caused by studs were estimated and compared. A new method of estimating thermal efficiency of insulation material was used to compare modeled walls and to evaluate the effectiveness of the exterior sheathing insulation. Maps of the temperature distribution in two compared wall systems, in their com ponents (i.e., cavity and studs) and the areas where walls intersect with other building envelope components (i.e., other walls, roofs, floors), were developed. These maps were used as an aid to estimate the areas affected by existing thermal bridges and to calculate R-values for these areas. These R-values were used to calculate overall wall (average whole wall) R-values and include the effect of the thermal bridges caused by envelope structural coupling details. Several configurations of wall insulation and structural details for wood stud and metal frame walls were examined.