bluuebunny/crossref_metadata_2025 huggingface dataset:
c-Fos Expression in the Brains of Behaviorally “Split” Hamsters in Constant Light: Calling Attention to a Dorsolateral Region of the Suprachiasmatic Nucleus and the Medial Division of the Lateral Habenula
Authors: Tavakoli-Nezhad Mahboubeh , Schwartz William J.
Published: November 2005

“Splitting” of circadian activity rhythms in Syrian hamsters maintained in constant light appears to be the consequence of a reorganized SCN, with left and right halves oscillating in antiphase; in split hamsters, high mRNA levels characteristic of day and night are simultaneously expressed on opposite sides of the paired SCN. To visualize the splitting phenomenon at a cellular level, immunohistochemical c-Fos protein expression in the SCN and brains of split hamsters was analyzed. One side of the split SCN exhibited relatively high c-Fos levels, in a pattern resembling that seen in normal, unsplit hamsters during subjective day in constant darkness; the opposite side was labeled only within a central-dorsolateral area of the caudal SCN, in a region that likely coincides with a photo-responsive, glutamate receptor antagonist-insensitive, pERK-expressing cluster of cells previously identified by other laboratories. Outside the SCN, visual inspection revealed an obvious left-right asymmetry of c-Fos expression in the medial preoptic nucleus and subparaventricular zone of split hamsters killed during the inactive phase and in the medial division of the lateral habenula during the active phase (when the hamsters were running in their wheels). Roles for the dorsolateral SCN and the mediolateral habenula in circadian timekeeping are not yet understood.
Reentrainment of the Circadian Pacemaker through Three Distinct Stages
Authors: Liu Tiecheng , Borjigin Jimo
Published: November 2005

Circadian rhythms are endogenously generated by a central pacemaker and are synchronized to the environmental LD cycle. The rhythms can be resynchronized, or reentrained, after a shift of the LD cycle, as in traveling across time zones. The authors have performed high-resolution mapping of the pacemaker to analyze the reentrainment process using rat pineal melatonin onset (MTon) and melatonin offset (MToff) rhythms as markers. Following LD (12:12) delays of 3, 6, and 12 h, MTon was phase locked immediately, whereas MToff shifted rapidly during the initial 1 through 3 cycles. In all animals, the MToff shifted beyond their expected phase positions in the new LD cycle, which resulted in a transient expansion of melatonin secretion duration for several cycles. It took MToff only 1, 2, or 3 cycles to complete most of the required phase shifts after 3, 6, or 12 h of the LD cycle delays, respectively. However, the final stabilization of phase relationships of both MTon and MToff required at least 6 cycles for rats experiencing a 3-h LD delay and much longer for the rest. These results reaffirmed the notion that both onset and offset phases of melatonin rhythms are important markers for the pacemaker and demonstrated that the reentrainment of the central pacemaker to a delay shift of the LD cycle is a 3-step process: an immediate phase lock of onset and a rapid delay shift of offset rhythms, overshoot of the offset, and, finally, a slow adjustment of both onset and offset phases. This study represents the 1st detailed analysis of the pacemaker behavior during reentrainment using melatonin and supports the notion that the eventual adaptation of the circadian pacemaker to a new time zone is a time-consuming process.
Tissue-Specific Disruption of Rhythmic Expression of Dec1 and Dec2 in Clock Mutant Mice
Authors: Noshiro Mitsuhide , Furukawa Masae , Honma Sato , Kawamoto Takeshi , Hamada Taizo , Honma Ken-ichi , Kato Yukio
Published: November 2005

DEC1 and DEC2—basic helix-loop-helix transcription factors—exhibit a circadian expression in the suprachiasmatic nucleus and other peripheral tissues and seem to play roles in regulating the mammalian circadian rhythm by suppressing the CLOCK/BMAL1-activated promoters of Per1, Dec1, and Dec2. The authors present data on the expression patterns of mRNA for Dec1, Dec2, Per2, Dbp, and Npas2 in various tissues of wild-type and homozygous Clock mutant mice ( Clock/ Clock). The Clock mutation resulted in extreme reduction of Dec1 expression in kidney, heart, and skeletal muscle but not in liver, whereas it strongly repressed Dec2 expression in liver, kidney, and heart, while Dec2 expression in skeletal muscle remained rhythmic. Per2 also showed the tissue-dependent disruption of the rhythmicity by Clock mutation, whereas rhythmic expression of Dbp in Clock mutant mice disappeared in all tissues examined. Npas2, a structurally and functionally related gene to Clock, showed significant levels of expression in the liver and kidney with a robust rhythmicity, which was also affected by Clock mutation. These marked changes in the Dec1 and Dec2 expression, as well as in the Per2, Dbp, and Npas2 expression in the periphery by Clock mutation, indicated that CLOCK plays a major role in the expression of these genes in most tissues. However, circadian expression of Dec1 in liver and kidney and that of Dec2 in skeletal muscle of Clock mutant mice suggested that CLOCK-independent circadian regulation operates in some tissues.
Osteoblast MC3T3-E1 Culture on a Fast-setting Carbonated Hydroxyapatite Bone-like Material
Authors: Mao K. Y. , Hao L. B. , Tang P. F. , Wang Y. , Wang J. F. , Lu S. B. , Liao S. S. , Cui F. Z.
Published: November 2005

Using ultra-fine grain technology, a fast-setting type of carbonated hydroxyapatite (CHA) material from Ca3(PO4)2·3H2O (ACP), CaCO3, Ca(H2PO4)2 (MCPA) and Na3PO4 was prepared. The ultra-fine particles (3 m) shortens the setting time, to form bone like material with 5.2wt% carbonation. Osteoblastic MC3T3-E1 cells were cultured with CHA material to observe cell adhesion, proliferation and differentiation. There were no obvious differences in adhesion and proliferation rate of MC3T3-E1 cells between the CHA and the control group. MC3T3-E1 cells on the surface of CHA observed by a scanning electron microscope (SEM). The alkaline phosphatase (ALP) activity of the cells on the CHA was higher than the control, and collagen I (COL 1) mRNA expressed on the CHA was also significantly higher than the control. This CHA bone material exhibited biocompatibility and osteo-conductive properties that are sought for bone repair and scaffolding for tissue engineering. *Author to whom correspondence should be addressed.
Biodistribution and Antitumor Activity Induced by Carboxymethylcellulose Conjugates
Authors: Uglea Constantin V. , Pârv Anton , Corjan Maria , Dumitriu Alina D. , Ottenbrite Raphael M.
Published: November 2005

New polymers with antitumor activity were synthesized by conjugating ethyl p-aminobenzoate (benzocaine) and N-hydroxy-2,3-dihydroxybenzamide (Didox) onto carboxymethylcellulose (CMC) and oxidized CMC. The biological tests ( in vitro and in vivo) for these CMC derivatives exhibited prolonged half-life in serum, accumulation in the solid tumors, and inhibition of the tumor growth. The latter effect was attributed to the permeability and retention (EPR) effect.
Perspectives On: Polymeric Drugs and Drug Delivery Systems
Authors: Thatte Suhas , Datar Kapil , Ottenbrite Raphael M.
Published: November 2005

Therapeutic uses of a variety of drug carrier systems have significant impact on the treatment and potential cure of many chronic diseases, including cancer, diabetes, mellitus, rheumatoid arthritis, HIV infection, and drug addiction. Drug delivery technology is a multidisciplinary science involving the physical, biological, medicinal, pharmaceutical, biomedical engineering and biomaterial fields. Polymeric systems can deliver drugs directly to the intended site of action and can also improve efficacy while minimizing unwanted side effects elsewhere in the body, which often limit the long-term use of many drugs. In this article, some recent publications on several polymeric drug conjugates, gene delivery systems and polymer implants are addressed.
Effects of Tape Tension on Residual Stress in Thermoplastic Composite Filament Winding
Authors: Lu Haibo , Schlottermuller Martin , Himmel Norbert , Schledjewski Ralf
Published: November 2005

Thermoplastic composite filament winding is a viable technique for manufacturing composite-reinforced pressure pipes and vessels. Residual stresses developed during the filament winding process have already received much attention in the past. Unreasonable residual stresses may result in distortion, matrix cracking, and interply delaminations. A model containing four submodels is developed in a previous research work. Some methods, such as adjusting tape tensions and temperatures are found to control the residual stress profile. The residual stress profile can be adjusted to a satisfactory level, which can avoid defects and even reduce weight and save material. Adjusting the tape tension is one of the parameters that controls the residual stress in thermoplastic composite filament winding. From a practical point of view, it is easy to realize even on an industrial scale. Experiments on two materials (glass fiber–polypropylene (G–PP) and carbon fiber–poly(ether-ether-ketone) (C–PEEK)) are made by using a variety of different tape tensions. The results proved the conclusions of theoretical work and agree well with the model predictions.
Liquid Molding of Carbon Fabric-reinforced Nylon Matrix Composite Laminates
Authors: Pillay Selvum , Vaidya Uday K. , Janowski Gregg M.
Published: November 2005

The present work addresses the processing parameters, methodology, and limitations of vacuum assisted resin transfer molding (VARTM) of carbon fabric-reinforced thermoplastic polyamide 6 (PA6) matrix panels on the laboratory scale. VARTM is a mature technology for producing large-scale thermoset composite parts/structures but has not been used for thermoplastic composites, which are manufactured primarily by compression molding, extrusion, and/or injection molding. In general, liquid molding of thermoplastics has limitations, such as high resin viscosity, high temperature processing requirements, and a short processing window. The materials used in this study are casting grade PA6, "-caprolactam with a sodium-based catalyst, and an initiator. This system allows the resin to maintain a very low viscosity (<1 Pa s) for a reasonable period of time, at relatively low temperatures (100C). The carbon fabric preform is infused using VARTM after which the resin is fully polymerized in situ. The process developed for using VARTM to produce carbon fabric-reinforced PA6 matrix composites is explained in detail. Microscopic studies are presented to evaluate wet-out of the fibers at both the tow and the filament levels. The effects of infusion temperature and flow distance on the fiber weight fraction and crystallinity of the PA6 resin are investigated. The degree of monomer conversion to polymer is determined.
Mechanical Properties and Swelling Behavior of Short Glass Fiber Reinforced Polyester Composites
Authors: Singh Paramjit , Kaushik Anupama , Kaur Kirandeep
Published: November 2005

Chopped strand glass fiber reinforced particle-filled polymer composite with different volume fractions of glass fibers has been investigated for tensile strength. Both the properties have been studied with respect to varying fiber content i.e., from 1 to 10%. In addition, the effect of various acids, alkalies, and solvents has been investigated. It has been found that fiber reinforcement increases the chemical absorption. Swelling studies have also been done for NaCl (15%) and distilled water, and the diffusivity coefficient and sorption coefficient are calculated. The sorption coefficient increases with increasing fiber content while the diffusivity coefficient decreases with increasing fiber content.
Herman Gorter and the Origins of Marxism in China
Authors: Knight Nick
Published: November 2005

Until 1921, the texts on Marxism aimed at reaching the Chinese Communist movement were dominated by an economic determinist interpretation of the materialist conception of history. Many Chinese converts to Marxism considered that belief in “orthodox” Marxism necessitated belief in its economic determinism. In 1921, with the publication in China of the famous Dutch Marxist Herman Gorter's An Explanation of the Materialist Conception of History, it became evident that there were alternatives to economic determinism which could also claim to be “orthodox” Marxism. Gorter's flexible and multifaceted perspective on Marxism allowed that many factors can influence “historical evolution,” and that they can interact in ways specific to particular historical contexts. Gorter emphasized the political and ideological struggles of the working class as central to the success of revolution. He nevertheless insisted, following Engels, that the economic factor was ultimately dominant. Gorter's ideas were well received by Chinese Marxists, particularly his Chinese translator Li Da who amplified the influence of Gorter's Marxism in his own prolific essays on the materialist conception of history. It is possible that Mao Zedong was influenced by Gorter's ideas, either directly or indirectly via the writings of Li Da, and the evidence for this is evaluated.
Destroying the Remembered and Recovering the Forgotten in Chai
Authors: Xudong Zhao , Bell Duran
Published: November 2005

Beijing is currently undergoing a host of dramatic changes, as reflected in the popular symbol chai (see pdf for characters). Chai means destruction; but it also refers to antiquated things or ideas that should be destroyed. By presenting chai, one is able to arouse into memory certain forgotten things that previously rested in the background. However, the reconstructed forgotten memories that one actually remembers differ from the actually forgotten. In this way prevailing Chinese conceptions of contemporary social transformations can be configured into recollections of constructed images of the past; and the past can be lost while being remembered. In this article, this process of creative remembering and forgetting will be illustrated by reference to changes in customs and residential ownership. We shall argue that traditionalism and modernity in contemporary China should be seen as circular transformations between remembering and forgetting.
Producing the Governable Employee
Authors: Mir Ali , Mir Raza
Published: November 2005

Workplace empowerment and the issues surrounding it have been well documented in the organizational literature on the topic, with critiques centered on the question of whether it is possible to craft an 'empowered' workplace where employees who are embedded within capitalist relations of production are actually able to exercise meaningful control over the environment in which they labor. Our contention in this paper is that workplace empowerment cannot be analyzed in isolation, but must be seen as a part of a broader managerial discourse that attempts to serve the organizational project. Following on from Foucault's delineation of the concept of governmentality and Gramsci's notes on hegemony, we read empowerment as a part of the modern operation of power, and as an integral component of a system of signification that is employed in order to produce a governable, organizational subject.
The Indigenous Woman as Victim of Her Culture in Neoliberal Mexico
Authors: Newdick Vivian
Published: November 2005

This article examines the appearance of an indigenous woman victim subject at the intersection of global and national rights discourses in Mexico. In the case of the rape of three indigenous women by the Mexican Army, in World Bank policy recommendations in which culture and gender are cast as 'impediments to development', and in everyday explanations for poverty, culture is cast as harmful to indigenous women. Structural violence and indigenous women's agency are obscured. This victim subject emerges to contest recent destabilizations of the meanings of gender and culture in the wake of indigenous women's militancy in the 1994 Zapatista uprising.
Dynamic Response of a High Aspect Ratio Wing Equipped with PZT Patches – A Theoretical and Experimental Study
Authors: Abramovich Haim , Weller Tanchum , Ping Siow Yeen
Published: November 2005

The present study is aimed at demonstrating both the capability and the relevant restrictions of piezoceramic elements (patches) to provide enough authority to control the dynamic behavior of a full size wing type structure (supposedly more rigid). Therefore, a 3000-mm long composite wing, that represents a typical high aspect ratio (AR 1/4 16.7) wing was designed and fabricated. The theoretical dynamic behavior of the wing box was calculated using the MSC/NASTRAN finite element code. The wing was excited using bonded piezoelectric patches at its first five natural frequencies. The experimental results proved the capability to excite real type structures using piezoelectric patches. The present composite wing will be used as a test-bed to evaluate the performances of piezoelectric materials in vibration control and flutter suppression of flexible wings.
Dynamic Formulations of Plates with Shunted Piezoelectric Materials
Authors: Park Chul H. , Kim Young H. , Park Hyun C.
Published: November 2005

Vibration control of plates with a passive electrical damper is presented in this article. This electrical absorber, piezoelectric patches connected with a resistor and an inductor in series, is analogous to the damped mechanical vibration absorber. For estimating the effectiveness of the piezoelectric absorber, the governing equations of motion are derived by applying the classical laminate plate theory and Hamilton's principle. The theoretical analysis developed is validated experimentally for the simply supported aluminum plates to demonstrate the performance of a passive electrical damper. The model developed presents an invaluable means for designing and predicting the performance of a smart plate that can be used in many critical engineering applications.
A Magnetorheological Piezohydraulic Actuator
Authors: Yoo Jin-Hyeong , Sirohi Jayant , Wereley Norman M.
Published: November 2005

Magnetorheological (MR) fluids can be used in a variety of smart semiactive systems. The MR damper shows an especially great potential to mitigate environmentally induced vibration and shocks. Another aspect of MR fluids is the construction of MR valve networks in conjunction with a hydraulic pump resulting in a fully active actuator. These devices are simple, have few moving parts, and can be easily miniaturized to provide a compact, high energy density pressure source. The present study describes a prototype MR-piezo hybrid actuator that combines the piezopump and MR valve actuator concepts, resulting in a self-contained hydraulic actuation device without active electromechanical valves. Durability and miniaturization of the hybrid device are major advantages due to its low part count and few moving parts. An additional advantage is the ability to use the MR valve network in the actuator to achieve controllable damping. The design, construction, and testing of a prototype MR-piezo hybrid actuator is described. The performance and efficiency of the device is derived using ideal, Bingham plastic and biviscous representations of MR valve behavior, and is evaluated with experimental measurements. This study seeks to provide a design tool to develop an actuator for a specific application.
Suppression of Noise Radiation from a Plate Using Self-Sensing Actuators
Authors: Qiu Jinhao , Tani Junji , Haraguchi Masakazu
Published: November 2005

This article presents a study of active noise isolation using an advanced composite board with built-in piezoelectric elements, which are used as both sensors and actuators. An identification system, which estimates the radiated sound from the voltage signals of the built-in piezoelectric elements in the smart board, was constructed based on Rayleigh's integral formula so that no external microphone is needed for noise control. A FIR (Finite Impulse Response) filter was used as the controller and its coefficients were updated adaptively using the Filtered-X LMS algorithm to minimize the estimated value of the sound pressure. The technique of self-sensing actuators was also used to reduce the number of needed piezoelectric elements in the control. Experiments were performed and the results showed that the transmitted noise level was successfully reduced at several resonant peaks.
Numerical Simulations of Ferromagnetic Microstructures: Motion of the Walls and Effect of Nonmagnetic Impurities
Authors: Bernadou Michel , Depeyre Sophie , He Song , Meilland Philip
Published: November 2005

By using a modelization based on the minimization of appropriate total energy functionals, we have realized numerical simulations of various effects, which appear in ferromagnetic or magnetostrictive materials at a microscopic scale. In particular, we have obtained a good approximation of hysteresis curves, magnetic domains, and interactions between magnetizations and deformations. This article emphasizes more specifically the behavior of the magnetic field inside of the walls, the motion of the walls under an evoluting external magnetic field, and the effect of impurities on this motion of the walls.
Recent Research on Adaptive Structures and Materials: Shape Memory Alloys and Aeroelastic Stability Prediction
Authors: Matsuzaki Yuji
Published: November 2005

Macroscopic, microscopic, and mesoscopic lumped-parameter models of shape memory alloy wires subjected to axial loads and new flutter prediction methods of a steady and a non-steady aeroelastic system will be presented with some comparison to previous studies.
A Study on The New Technological Concept of Robotic Cellular Phone (RCP)
Authors: Kim Seungwoo , Choe Jaeil
Published: November 2005

The robot technology (RT), along with the rapid growth of information technology (IT) is being developed as the next generation of a future technology. Current robots require advanced technology, such as soft computing, human-friendly interface, interaction technique, speech recognition, object recognition, etc., unlike the industrial robots of the past. Recently, cellular phone (CP) has been one of the most important technologies in the IT field, and it has occupied a preeminent position industrially and economically. To produce the best CP in the world, a new technological concept and its advanced implementation technique are required, due to severe competition in the world market. Therefore, this study develops a new technological concept, called the robotic cellular phone (RCP), in which a synergistic effect can be generated by merging RT and IT. RCP, i.e., CP having personal robot services, will be an intermediate hi-tech personal machine between one CP-a-person and one robot-a-person generations.

RCP infra consists of RCPMobility, RCPInteraction, and RCP Integration technologies. For RCPMobility, human-friendly motion automation and personal service with walking and arming ability are developed. RCP Interaction is achieved by modeling an emotion-generating Integration which, in a miniature, integrates the robotic modules into CP, is developed with application service programs. By joining intelligent algorithms and CP communication network with the three base modules, an RCP system is constructed.

This article presents the definition, basic theory and experimental results of the RCP subtechnologies. We confirm a good performance of the RCP through the experimental results.
Optimal Allocation of Piezoelectric Passive Dampers for a Panel Exposed to Fluid Flow: Maximum Critical Velocity Design Problem
Authors: Tanaka Masao , Todoh Masahiro , Maetaka Akeshi
Published: November 2005

In this study, the improvement of the stability limit of a panel exposed to fluid flow, a typical nonconservative structural system is discussed. As an adaptive panel, piezoelectric materials are embedded into the panel making piezoelectric passive dampers accompanying a pair of resistance and inductance. The stability limit of such a panel is characterized by means of the critical velocity of external flow that induces panel flutter, and the critical flow velocity is maximized by the appropriate allocation of piezoelectric passive dampers and the selection of circuit parameters of dampers. The damper allocation and circuit parameters selection are optimized using a simple genetic algorithm. Numerical cases demonstrate the increase of critical flow velocity by appropriate design of damper allocation.
Design and Verifications of an Autonomous Gain–Phase Sensor for Thick Beams
Authors: Liu Y. P. , Huang Y. T. , Lee C. K. , Wu Jeremy W. J. , Hsiao Wendy W. H.
Published: November 2005

Both theoretical analysis and experimental verifications are performed on distributed sensors for Timoshenko beams. Development of a modal sensor for thick beams is hindered by the fact that it cannot be observed. It has been found that if we consider a modal sensor that neglects the shear strain effect in thick beams, we can develop an approximated modal sensor for thick beams. In addition, a previous concept is extended based on an APROPOS device (Autonomous Phase–gain Rotational/linear Optimum Piezoelectric Sensing) originally developed for thin beams to thick beams. Our successful results clearly show that autonomous gain and phase of thick-beam-based sensors and actuators are feasible.
Development of a Maximum Energy Extraction Control for the Smart Spring
Authors: Nitzsche Fred , Harold Tim , Wickramasinghe Viresh K. , Yong Chen , Zimcik David G.
Published: November 2005

Most active vibration suppression approaches have attempted to suppress structural vibrations through the use of active material actuators, such as piezoceramic, that are incorporated into a structure to act directly against vibratory loads. These approaches require the actuators to simultaneously supply significant force and deflection to effectively suppress vibration. Unfortunately, successful implementation of these approaches has been hindered by the electromechanical limitations of piezoceramic actuators due to high power requirements in active vibration control applications. The Smart Spring concept is a unique approach that is designed to actively control combinations of dynamic impedance characteristics of a structure, such as the stiffness, damping, and effective mass to suppress vibration. The Smart Spring does not use actuators to perform work directly against excitation loads, but rather adaptively varies the effective structural impedance properties. Therefore, the piezoceramic actuators in the Smart Spring are not required to simultaneously produce large forces and deflections. Thus, the concept requires considerably less power because it enables active vibration control in an indirect manner. This study demonstrates the ability of the Smart Spring to control dynamic impedance characteristics of a structure through numerical simulations and experimental investigations. In addition, the development of a feedback control system is demonstrated. According to the control strategy, the impedance characteristics of the Smart Spring are continuously changing in order to maximize the extraction of the mechanical energy of the system.
Aeroelastic Considerations on Shape Control of an Adaptive Wing
Authors: Bae Jae-Sung , Kyong Nam-Ho , Seigler T. Michael , Inman Daniel J.
Published: November 2005

In this work, the aeroelastic effects on the shape control of an adaptive camber wing are studied through numerical simulation. The adaptive camber concept consists of a compliant beam, actuated by a series of piezoelectric actuators, embedded within the rib to deform the wing in an effort to produce a desired lift. Piezoelectric laminated plate theory is used to model the actuation force and the resulting camber line shape of the wing. The aerodynamic forces are calculated using two-dimensional airfoil theory and a feedback shape control algorithm is applied to obtain the desired camber. The results of the simulations demonstrate that the deformations due to aerodynamic forces are large enough to significantly alter the total lift produced by the wing as compared with the lift produced solely through actuation. Using an adaptive control algorithm, aeroelastic shape control of the adaptive camber wing is successfully achieved. Moreover, it is shown that, due to aerodynamic forces, the power requirements of shape control might be reduced.
Feature Extraction with Discrete Wavelet Transform for Drill Wear Monitoring
Authors: Sun Qiao , Tang Ying , Yang Lu Wei , Ji Yuan
Published: November 2005

The dynamics of drilling processes presents chaotic and unsteady characteristics, which prevent deterministic description. Vibration signals obtained during the microdrilling process contain rich information reflecting tool and process conditions. Experiments described in this paper show that as drill wear develops and intensifies, the energy distribution of the vibration signal tends to shift towards the low-frequency range. Traditional frequency domain analysis through the fast Fourier transform is not able to capture such transitions with desirable accuracy since the process is highly non-stationary. We propose a new method that combines the discrete wavelet transform with statistical estimations of the signal energy distribution to extract features describing such energy shifts quantitatively. Through a multiresolution transformation, four feature parameters most sensitive to drill wear conditions are extracted. A tool wear index is proposed as a linear function of the extracted features, which also represents the severity of tool wear. The effectiveness of the proposed method is shown through a case study at the end.
Robust Sliding Mode Control of a Full Vehicle Without Suspension Gap Loss
Authors: Yagiz N. , Sakman L. E.
Published: November 2005

A seven-degrees-of-freedom full vehicle model is used to design a robust controller and to investigate the performance of active suspensions without losing the suspension working space. Zero reference for vehicle body displacement finishes suspension working distance. Thus, a new approach is suggested in this paper. Force actuators are placed parallel to the suspensions and non-chattering sliding mode control is applied. Since any change in vehicle parameters because of different load or road conditions adversely affects the performance of the ordinary control methods, a robust control method is preferred. To obtain the desired improvement in ride comfort, we aim to decrease the magnitudes of the body vibrations and their accelerations. We present body bounce, pitch and roll motions of the vehicle with the conventional approach and the proposed approach without suspension gap loss, both in the time domain in the case of traveling over a step road profile and in the frequency domain. The results of both approaches are compared. The solution to the suspension gap loss problem has also been presented on periodic road surfaces. At the end of the paper, we discuss the improvement in the performance of the new controller with its robust behavior and the advantage of the new approach.
Global and Local Wave Vibration Characteristics of Materially Coupled Composite Beam Structures
Authors: Mei C.
Published: November 2005

A unique feature of fiber-reinforced composite materials is that it allows structural tailoring for favorable dynamic performance, due to the directional nature of composite materials. The directional nature causes material coupling, which results in coupled vibrational modes and complicates dynamic analysis. Most of the up-to-date composite structure related dynamic studies focus on free vibration analysis. In this paper, the local wave transmission and reflection characteristics at various discontinuities are studied first. Such discontinuities include general point supports, boundaries and change in sections. The matrix relations between the injected waves and externally applied forces and moments are also derived. By assembling these matrices, both free and forced vibration responses of materially coupled composite Euler–Bernoulli beams are obtained. The wave-based vibration analysis approach is found concise and systematic. Numerical examples are given.
Improvement of Dry-cured Iberian Ham Quality Characteristics Through Modifications of Dietary Fat Composition and Supplementation with Vitamin E
Authors: Ruiz J. , de la Hoz L. , Isabel B. , Rey A. I. , Daza Argimiro , López-Bote C. J.
Published: November 2005

The effects of dietary fat composition and vitamin E supplementation on the quality characteristics of dry-cured Iberian hams ripened for two years were studied. Thirty Iberian Duroc pigs were fed diets containing three levels of poly and monounsaturated fatty acids. Within each dietary fat treatment, one group was fed a basal level of vitamin E (20mg α-tocopheryl acetate/kg diet) and the other group received a supplemented level (200mg α-tocopheryl acetate/kg diet). Dietary fat composition significantly affected total saturated fatty acids content of neutral and polar lipids from dry-cured Iberian ham ( p 0.012 and p 0.003, respectively). However, diet fatty acids composition did not influence either total monounsaturated or total polyunsaturated fatty acids of neutral and polar lipids. Vitamin E supplementation significantly enhanced dry-cured Iberian ham α-tocopherol content ( p 0.001). This, in turn, led to significantly lower levels of TBARS on days 6 and 9 of storage in slices from dry-cured Iberian hams made of vitamin E supplemented pigs and also lower oxidation levels in an induced lipid oxidation test in samples from those pigs. Dietary fatty acid composition did not significantly affect either TBARS during slices storage or malonaldehyde content in the induced oxidation test. No effect of vitamin E supplementation was observed in ham volatile aldehyde profile, but dietary fat significantly affected hexanal ( p 0.02), heptanal ( p 0.05) and total aldehyde content ( p 0.02), with those pigs fed a diet rich in PUFA showing higher values. Using diets supplemented in α-tocopherol and rich in monounsaturated fatty acids seemed adequate dietary strategies for feeding Iberian hams reared indoors.
Screening of Portisins (Vinylpyranoanthocyanin Pigments) in Port Wine by LC/DAD-MS
Authors: Mateus N. , Oliveira J. , González-Paramás A. M. , Santos-Buelga C. , de Freitas V.
Published: November 2005

Samples of a two-year-old Port red wine were fractionated by Toyopearl gel column chromatography yielding different coloured fractions. Anthocyanin-derived compounds were tentatively identified by LC/DAD-MS in the different eluted fractions. Several pigments were found to correspond to a recently reported family of pyranoanthocyanin compounds named portisins, supposedly arising from the reaction between anthocyanin-pyruvic acid adducts and flavanols in the presence of acetaldehyde. These pigments present a structure in which pyranoanthocyanins are linked to flavanols (catechins or procyanidin dimers) through a vinyl linkage. These pigments showed a UV-visible spectrum with a λmax batochromically shifted from that of genuine anthocyanins, thereby contributing to a more bluish hue.
Biogenic Amines and Polyamines and Total Aerobic Count During Storage of Vacuum-Packaged Porcine Kidney, Liver and Spleen
Authors: Valero B. Villanueva , Bauer F. , Smulders Frans J.M. , Ariño A. , Hagen U. , Paulsen P.
Published: November 2005

Biogenic amines and polyamines (cadaverine, histamine, 2-phenylethylamine, putrescine, spermidine, spermine, tryptamine and tyramine) were analysed in vacuum-packaged porcine livers, kidneys and spleens stored at 3°C and 7°C (for up to 6 days) or 0°C (for up to 21 days). Total aerobic count, pH and sensory assessment were done in parallel. While histamine, 2-phenylethylamine and tryptamine concentrations were nearly constant, spermidine and spermine showed a moderately declining trend, irrespective of the storage temperature. Cadaverine, putrescine and tyramine concentrations increased with storage time and temperature. Maximum concentrations at day 21 at 0°C were: 122mg/kg for cadaverine, 207.35mg/kg for putrescine and 63.19mg/kg for tyramine. The correlation of concentrations of the latter three amines and the total aerobic count was ranging from r 0.54 to 0.89. A significant rise in amine concentrations was observed only when the total aerobic count exceeded 6 log10 cfu/g. Concentrations of cadaverine, putrescine and tyramine may be useful to confirm spoilage of vacuum-packaged inner organs. The fraction of the potential food-borne pathogen Aeromonas in high-pH organs (spleen, kidney) during storage was significantly higher than in liver, with low pH. It was observed that the spermine: spermidine ratio of spleen (3:2; weight base) was significantly different from that of liver and kidney (4:1).
Note. Seasonal Variations of Fatty Acid Composition in Wild Marine Shrimps (Penaeus semisulcatus De Haan, 1844 and Metapenaeus monoceros Fabricus, 1789) from the Eastern Mediterranean Sea
Authors: Yanar Y. , Çelik M.
Published: November 2005

Seasonal fatty acid profiles of Penaeus semisulcatus and Metapenaeus monoceros were investigated. Palmitic (16:0), stearic acid (18:0), oleic (18:1), palmitooleic acid (16:1), arachidonic acid (20:4), eicosapentaenoic (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) were found to be the most abundant fatty acids in both shrimp species. Fatty acid profile showed seasonal changes. The highest EPA DHA contents were recorded during winter (January) in both species.
Morphological and Molecular Studies of Banana Starch
Authors: Bello-Pérez L. A. , De Francisco A. , Agama-Acevedo E. , Gutierrez-Meraz F. , García-Suarez F. J.L.
Published: November 2005

Molecular and morphological characteristics of banana starch were determined by different spectroscopic techniques. Light and scanning electron microscopy showed the molecular order, shape and size of starch granules. Banana starch granules had a lenticular shape with an average size of 39 m. The X-ray diffraction study showed starch granules with a pattern of a mixture between the A- and B-type polymorphs, also referred to as C-type. The absorbance ratio (1045/1022cm 1) measured by infrared spectroscopy was 1.12, suggesting that the crystalline component was higher than the amorphous regions. Gelatinisation temperature assessed by differential scanning calorimetry was 77.6°C with a gelatinisation enthalpy of 23.4J/g. These data stated that banana starch had a high crystallinity level, which might be important in several food applications.
Effect of Texture Modifiers on the Physicochemical and Sensory Properties of Dried Fufu
Authors: Adebowale A. A. , Sanni L. O. , Awonorin S. O.
Published: November 2005

Glycerol monostearate (GMS) and monoglyceride phosphate (MGP) were added to fufu flour at different levels (0.5%, 1.0% and 1.5%) in hydrated and powdered form. There were evaluated the effects of those additives on physicochemical and sensory properties of dried fufu. Addition of GMS and MGP had a significant effect on the swelling power, solubility, pasting properties and sensory quality of fufu flour. Results obtained were: Dispersibility (69%-70.33%), water absorption index (WAI, 47.7%-54.4%), least gelation concentration (LGC, 4.67%-6.67%) and water absorption capacity (WAC, 119.3%-136%) for the fufu flour treated with GMS and MGP. Solubility of the samples mixed with the powdered form of the modifier ranged between 23.2% and 31.7%, while that of the samples mixed with the hydrated form of GMS and MGP ranged between 5.3% and 12.7%. The pasting time varied between 8.25min and 18.50min, fufu flour mixed with 1.5% GMS powder had the lowest value while that mixed with 1.0% MGP powder and 0.5% hydrated MGP recording the highest value. Pasting temperature ranged from 67.00°C to 72.00°C, with flour mixed with 1.0% hydrated GMS and 0.5% GMS powder having the lowest and highest value, respectively. The highest value of peak viscosity (762.50BU) was recorded by fufu flour containing 1.0% hydrated GMS. The lowest value of starch stability (255.50BU) was recorded by fufu flour without modifier while the highest value (499.00BU) was recorded by fufu flour containing 0.5% GMS powder. There were significant differences ( p 0.05) in the sensory qualities except for colour of fufu flour samples. The overall quality index (OQI) comprised between 5.24 and 6.01, fufu sample containing 0.5% hydrated GMS had the lowest OQI and that containing 1.0% hydrated MGP the highest OQI. Addition of 0.5% texture modifier to dried fufu may be economically feasible according to the estimated cost of production.
Non-uniform Compressive Strength of Debonded Sandwich Panels – II. Fracture Mechanics Investigation
Authors: Berggreen C. , Simonsen B. C.
Published: November 2005

This article describes the development, validation and application of a FEM based numerical model for prediction of residual strength of damaged sandwich panels. The core of the theoretical method is a newly developed procedure for prediction of the propagation of a face-core debond. As demonstrated, the method can predict the maximum load carrying capacity of real-life panels with debond damages, where the failure is governed by face-sheet buckling followed by debond growth. The developed theoretical procedure is an extension of the as Crack Surface Displacement method, here denoted as the Crack Surface Displacement Extrapolation method. The method is first developed in 2D and then extended to 3D by use of a number of realistic assumptions for the considered configurations. Comparison of the theoretical predictions to a series of large-scale experiments, described in [17], shows that the model is indeed able to predict the failure modes and the residual strength of damaged panels with accuracy sufficient for practical applications. This opens up for a number of important engineering applications, for example risk-based inspection and repair schemes.
Non-uniform Compressive Strength of Debonded Sandwich Panels – I. Experimental Investigation
Authors: Nøkkentved A. , Lundsgaard-Larsen C. , Berggreen C.
Published: November 2005

Face/core debond-damaged sandwich panels exposed to non-uniform compression loads are studied. The panel geometry is rectangular with a centrally located circular debond. The study primarily includes experimental methods, but simple finite element calculations are also applied. The complexity of applying a controlled non-uniform compressive load to the test panels requires a strong focus on the development of a suitable testrig. This is done by the extensive use of product development methods. The experimental results based on full-scale testing of 10 GFRP/foam core panels with prefabricated debonds show a considerable strength reduction with increasing debond diameter, with failure mechanisms varying between fast debond propagation and wrinkling-introduced face compression failure for large and small debonds, respectively. Residual strength predictions are based on intact panel testing, and a comparison between a simple numerical model and the experimental results shows fair agreement.
Static and Nonlinear Impact Analyses of Free–Free Sandwich Plates on a Solid Half-space
Authors: Qiao Pizhong , Yang Mijia
Published: November 2005

In this study, an elastic model for static and nonlinear impact responses of a composite sandwich plate on an elastic half-space including the anti-plane core effect is developed. The effects of the elastic half-space and the anti-plane core are studied, and the contact force history and maximal deflection are predicted. Compared to the available analytical static analysis of rigid plates on a solid half-space and the numerical finite element modeling using LS-DYNA, the proposed theoretical method shows its validity and advantages in predicting the static and impact behaviors of sandwich plates sitting on a solid half-space. The predicted non-uniform distribution of transferred force under static load sheds new light on the understanding of force action mechanism between the sandwich system and the solid half-space. The two important impact factors (i.e., the maximal deflection and the peak contact force) provided by this study can be used to determine the damage size and position. Further, the semi-analytical model developed can be served as a basis for optimal design of fully backed sandwich collision protection systems, of which both minimizing the rebounded residual velocity of the projectile and keeping the underneath protected structures intact are important.
Effects of Estrogen on Platelet Reactivity After Transient Forebrain Ischemia in Rats
Authors: Littleton-Kearney Marguerite T. , Gaines Jessica M. , Callahan Kevin P. , Murphy Stephanie J. , Hurn Patricia D.
Published: November 2005

Estrogen’s prothrombotic effects are of increasing concern, particularly in stroke risk and recovery. Using an ischemic rodent model, the authors sought to determine (a) if estrogen replacement increases postischemic platelet reactivity, (b) if changes in estrogen status alter intraplatelet endothelial nitric oxide synthase (eNOS) synthesis, and (c) if estrogen-mediated effects on platelets alter cerebral blood flow during reperfusion. Intact (I), ovariectomized (OVX), and OVX + 17 β -estradiol (E50) rats were subjected to 30 min of forebrain ischemia and 60 min of reperfusion. Using the platelet activation marker P-selectin, postischemic platelet reactivity was quantified by flow cytometry. In a separate cohort (I, OVX, E50), the authors quantified platelet eNOS by Western blot. Another cohort (OVX, E50) was subjected to ischemia/reperfusion, and cerebral blood flow was determined using the iodoantipyrine technique. Collagen-stimulated platelet P-selectin expression was increased in the OVX rats at 60 min of reperfusion, and this effect was reversed by estrogen treatment. No differences in platelet eNOS expression were detected among groups. Cerebral blood flow at 60 min reperfusion was comparable between the OVX and the E50 rats. The authors conclude that during reper-fusion, estrogen deficiency increases postischemic platelet sensitivity to stimuli in estrogen-deficient rats. Estrogen treatment mitigates effects of estrogen loss on platelets, but this early effect is apparently not caused by intraplatelet eNOS depression. Neither estrogen deficiency nor estrogen treatment changes early postischemic regional brain blood flow. In this rodent global cerebral ischemic model, physiologic doses of estrogen are not deleterious to platelet reactivity and may initially reduce postischemic platelet reactivity.
A Walking Program for Outpatients in Psychiatric Rehabilitation: Pilot Study
Authors: McDevitt Judith , Wilbur JoEllen , Kogan Joseph , Briller Joan
Published: November 2005

The purposes of this quasi-experimental pilot study were to determine adherence to a 12-week group-based moderate-intensity walking program for sedentary adult outpatients with serious and persistent mental illness and to examine change from baseline to after the walking program in health status (mental and physical health, mood, and psychosocial functioning) and exercise motivation (exercise outcomes expectancies, exercise decisional balance). The 15 volunteers in this study were aged 21 to 65 years and enrolled in psychosocial rehabilitation; they participated in a 12-week walking program meeting three times per week for 1 hr, supplemented with four health information workshops delivered at the beginning of the study. Participants received individual exercise prescriptions determined by preprogram fitness testing and used heart rate monitors during walking sessions. Thirteen participants (87%) completed the study and attended 76% of the walking sessions. Overall, they walked at lower intensity than prescribed, with pulses within target heart rate ranges 35% of the time during Weeks 1 through 4, 26% of the time during Weeks 5 through 8, and 22% of the time during Weeks 9 through 12. However, mood improved (Profile of Mood States, t = -2.51, two-tailed, df = 12, p = .02), as did psychosocial functioning (Multnomah Community Ability Scale, two-tailed, df = 12, t = 2.49, p = .02). The findings indicate a walking group may be feasible for rehabilitation programs. In addition to the known cardiovascular risk-reduction benefits of regular walking, walking may improve mood and psychosocial functioning in adults with serious and persistent mental illness.