bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aluminum Foam Structures and Compressive Properties Produced from Multiple and Differently Arranged Precursors
Authors: Asavavisithchai Seksak , Trepetch Supasiri , Sutisakomon Chonlatid 
Published: November 2014

AbstractLarge closed cell aluminum foam components, produced through a powder metallurgical route, normally need multiple foamable precursors. The larger the size of components, the more precursors are required. The placement of precursors in the mold prior to sintering is important for a successful foaming. The present study shows that the initial precursor arrangement has a significant effect on the final foam structure and its mechanical properties. The largest foam expansion, close to the geometry of the mold, with more uniform pore distribution was found in the foam with the arrangement of four precursors, which were placed horizontally at the bottom of the mold in two layers. This was due to the delayed foam collapse as a result of the different onsets of individual precursor expansion. The difference in heat conduction of distinct precursor positions resulted in different cellular structural characteristics which strongly affect compressive behavior of the Al foams.
The Effect of Aging Parameters and Roughness on the Wear Properties of Aluminum Alloy 6082
Authors: Cetinel Hakan , Ayvaz Mehmet 
Published: November 2014

AbstractThe aim of this study was to investigate the influence of aging parameters and initial roughness on the wear properties of the aluminum alloy AA 6082 (Al-Mg-Si). For this purpose, various heat treatments were carried out. Afterwards, the solutionized samples and artificially aged samples (at 185 °C for 3 and 6 h) were prepared in terms of two different average surface roughnesses via various grades of grinding. The wear behavior of the samples was investigated by a pin-on-disc wear test apparatus under four different applied loads (5, 10, 15 and 20 N) and five different sliding distances (250, 500, 750, 1000, 1250 and 1500 m). The sliding velocity was 30 cm × s−1. After the wear tests, the mass loss was measured for all samples and the worn surfaces were examined by scanning electron microscopy (SEM). The wear test results clearly show that with increasing hardness, the mass loss decreases, and the mass loss of the worn surfaces increases with increasing sliding distance, test load and initial roughness.
Behavior of Chopped Strand Mat and Woven Roving under Bending
Authors: Arifin Ahmad Mubarak Tajul , Abdullah Shahrum , Zulkifli Rozli , Wahab Dzuraidah Abdul , Rafiquzzaman Mohammad 
Published: November 2014

AbstractIn this study, lamination panels were fabricated using chopped strand mat (CSM) and woven roving fabric (WR) as reinforcement for two different types of specimens, type Eband type Pb, respectively. By a combination of plain materials composite lamination structures were formed, with [CSM/0/90/CSM]2sas an orientation layer for the structures. In this research study, the structural panel was produced by hand lay-up technique with a combination of unsaturated epoxy and polyester resin, separately. Therefore, with this publication, a characteristic combination of chopped strand mat/woven roving fabric, are presented. The experimental work for both types of specimens were performed by bending until the structure fails. The characteristics of different materials, i. e. the chemicals used and the composite lamination structure, were studied, because there are different types of damages in the structure of composite materials, such as delamination, matrix cracking, fiber-matrix damage and fiber pull-out. Furthermore, it can affect the behavior of composite materials in the whole structure. As a result, this process contributes to failure prevention, as the capabilities of the structures are known, before it can be used for any part, component or area. It was also shown that different configuration lamination layers influence the strength properties of the composite materials.
Experimental and Numerical Analysis of Foam-Filled Aluminum Conical Tubes Subjected to Oblique Impact Loading
Authors: Mat Fauziah , Ismail Khairul Azwan , Yaacob Sazali , Ahmad Zaini 
Published: November 2014

AbstractThis study aims to investigate the response of AA6061-T6 conical tubes under oblique impact loading, for variations in filler density and tube material by using experimentally validated model. Good correlations between the numerical and experimental results were observed. The initial peak force and dynamic force increase from AA6061-T6 to carbon steel tubes and further increase with increasing filler density, leading to increased energy absorption capacity. Conversely, the initial peak force and dynamic force of empty and foam-filled AA6061-T6 conical tubes decrease with the introduction of oblique loading as the load angle increases from 0° to 20°, leading to reduced energy absorption capacity. Carbon steel is relatively more advantageous compared with AA6061-T6 in terms of energy absorption, whereas AA6061-T6 is comparable with carbon steel because of its lower initial peak force.
Effects of Cutting Parameters and Point Angle on Thrust Force and Delamination in Drilling of CFRP
Authors: Yardimeden Ahmet , Kilickap Erol , Celik Yahya Hisman 
Published: November 2014

Abstract
Parts made of composite materials are generally produced by near-net-shape technology. However, additional machining operations such as drilling are often required to facilitate components assembling. Drilling of composite materials is also a common process in the assembly of aerospace and automotive composite structures. During drilling, unlike the conventional materials, a few damage forms may take place. Among these damage forms, the delamination is the most important one. Therefore, the experimental studies carried out on drilling of CFRP composite materials for determining optimum processing parameters are of great importance. In this particular study, delamination in CFRP composites caused by drilling was investigated. The composite material was drilled under various spindle speeds, feed rates and drill point angles. The results showed that delamination and thrust forces were affected by cutting parameters. It was demonstrated that feed rate and drill point angle make the largest contribution to the overall performance.
Formulation and evaluation of dexamethasone loaded stearic acid nanoparticles by hot homogenization method
Authors: Parvin Shumaia , Rafshanjani Md. Abu Shuaib , Kader Md. Abdul 
Published: November 2014

Dexamethasone is a type of steroid medication having anti-inflammatory and immunosuppressant effects. One of the major problems with this drug is its low solubility in water which results into poor bioavailability after oral administration. So the objective of the present work is to improve the solubility and dissolution rate of dexamethasone using its solid lipid nano particles (SLNPs) with stearic acid as solid lipid, lutrol F-68 as surfactant and tween-80 as stabilizer. SLNPs are prepared by hot homogenization method at different ratio of drug, lipid, surfactant and stabilizer and designated as DNP1 to DNP6. In vitro dissolution study was performed using the USP type II apparatus (paddle method) at 50 rpm to a temperature of 37°±0.5°C in distilled water containing 0.75% w/v SLS (sodium lauryl sulfate). The absorbance of sample was measured spectrophotometrically at ?max 239nm on a UV-Visible spectrophotometer. Release pattern of drug was found to follow zero order, first order and Korsmeyer-Peppas equations. Improvement of dissolution was observed in all the solid lipid nano particles as compared to pure drug. Pure drug showed only 27.25% release in 50 min whereas the dexamethasone SLNPs showed faster (66.19%) in vitro drug release. Hence, this finding indicates that dexamethasone SLNPs prepared by hot homogenization method can be used to enhance the dissolution rate and to show novel application to this drug delivery system.DOI: http://dx.doi.org/10.3329/icpj.v3i12.20829 International Current Pharmaceutical Journal, November 2014, 3(12): 331-335
Using social media to engage and develop the online learner in self-determined learning
Authors: Blaschke Lisa Marie 
Published: November 2014

Social media technology provides educators with an opportunity to engage learners in the online classroom, as well as to support development of learner skills and competencies. This case study explores the role of social media in promoting cognitive and meta-cognitive learner development while using a heutagogical teaching and learning approach. Research was conducted using questionnaires and interviews and incorporated the perspectives of both students and instructors on the use of social media in the online classroom and how media influenced interaction and learner development. Results indicate that students perceived specific social media (Google Docs, mind mapping and e-portfolio software) in conjunction with a unique learning activity as influencing specific cognitive and meta-cognitive skills (constructing new knowledge, reflecting on course content, understanding individual learning process). Research also indicated an increase in student familiarity with using social media and student research skills. This paper presents the findings from the case study, as well as general guidance to instructors for incorporating social media in the online classroom.Keywords: social media; heutagogy; e-learning; self-determined learning(Published: 10 November 2014)Citation: Research in Learning Technology 2014, 22: 21635 -http://dx.doi.org/10.3402/rlt.v22.21635
Les spécialités pharmaceutiques au XIX e siècle : statuts et fondements de l'innovation
Authors: Sueur Nicolas 
Published: November 2014

Le XIX e siècle est marqué, en France, par l’essor des spécialités : sirop d’opium composé d’Aubergier, sinapisme Rigollot, extraits sous vide d’Adrian... Les spécialistes sont le plus souvent des pharmaciens, qui présentent leurs créations comme des nouveautés, fruits de longues recherches en laboratoire. Or ces produits sont en réalité des thérapeutiques qui remontent à l’Antiquité, avec des innovations marginales portant sur les dosages et la composition. Mais ils répondent à une demande croissante de la médecine du XIX e siècle, qui continue d’affectionner ces méthodes anciennes. L’invention pharmaceutique repose d’abord sur la mise au point de procédés techniques permettant de fabriquer des spécialités en grand nombre. Ce changement d’échelle se traduit par la création de sociétés et l’apport de capitaux extérieurs. La mise au point de nouvelles machines accompagne et parfois précède l’invention pharmaceutique, même si la production reste en grande partie manuelle. Le développement de ces nouveaux produits s’explique par des motivations plus commerciales que thérapeutiques, avec une concurrence acharnée des fabricants pour le contrôle de ces spécialités.
Des militants en costume cravate. Regard socio-historique sur l'engagement des dirigeants étudiants de la MNEF (1973-1986)
Authors: Argibay Camilo 
Published: November 2014

Cet article est centré sur l’analyse socio-historique de l’engagement militant des dirigeants étudiants de la MNEF. En s’appuyant sur un matériau archivistique, il propose de revenir sur les espaces de socialisation dans lesquels ces étudiants étaient engagés. La première partie permet de saisir leur engagement au regard de leur environnement politique et syndical. L’évolution des rapports entretenus par la mutuelle avec d’autres organisations étudiantes et des mouvements partisans à partir des années 1970 constitue une grille de lecture indispensable à la bonne compréhension de cet engagement. Ces militants étudiants sont présents dans deux espaces de socialisation entremêlés : d’abord, une socialisation qualifiée de « militante », en raison de leur insertion dans des mondes militants plus vastes ; ensuite, une socialisation « gestionnaire », spécifique à la MNEF, en raison de leur statut particulier de jeunes dirigeants d’entreprise. En s’arrêtant sur les apprentissages de savoir-faire et les intériorisations de représentations, cet article revient finalement sur une forme d’accumulation de capital militant, élément qui permet de comprendre l’entrée en politique de plusieurs de ces leaders.
What’s killing the green menace: mortality factors affecting the emerald ash borer (Coleoptera: Buprestidae) in North America?
Authors: Lyons D. Barry 
Published: November 2014

AbstractEmerald ash borer,Agrilus planipennisFairmaire (Coleoptera: Buprestidae), is an Asian species that was introduced into North America in the mid-1990s. The beetle has the potential to devastate populations ofFraxinusLinnaeus (Oleaceae) species. Several species of Hymenoptera parasitoids have made the transition from North AmericanAgrilusCurtis hosts toA. planipennis, and some (e.g.,AtanycolusFörster (Hymenoptera: Braconidae) species) have caused substantial mortality. Invertebrate predators ofA. planipennishave been poorly investigated. Predation by woodpeckers (Aves: Picidae) has had the greatest impact onA. planipennispopulations. Native entomopathogens have also been observed in populations ofA. planipennisand are being explored as potential biological control agents.Agrilus planipennisis a freeze-intolerant species and as such perishes when its tissues freeze. However, the beetle can achieve a mean supercooling point of −30 °C by the production of cryoprotectants, especially glycerol. This low supercooling point in combination with temperatures higher than ambient in its overwintering microhabitat means that it can survive in most of its invaded range. As its distribution expands northward its cold hardiness may be challenged. North American species ofFraxinuspossess some resistance toA. planipennisvia defensive mechanisms, but these are quickly overcome by expanding larval populations. Intraspecific competition (via cannibalism and starvation) impacts larval survival.
Increased Ligament Thickness in Previously Sprained Ankles as Measured by Musculoskeletal Ultrasound
Authors: Liu Kathy , Gustavsen Geoff , Royer Todd , Wikstrom Erik A. , Glutting Joseph , Kaminski Thomas W. 
Published: November 2014

Context:Lateral ankle sprains are among the most common injuries in sport, with the anterior talofibular ligament (ATFL) most susceptible to damage. Although we understand that after a sprain, scar tissue forms within the ligament, little is known about the morphologic changes in a ligament after injury.Objective:To examine whether morphologic differences exist in the thickness of the ATFL in healthy, coper, and unstable-ankle groups.Design:Cross-sectional study.Setting:Laboratory.Patients or Other Participants:A total of 80 National Collegiate Athletic Association Division I collegiate athletes (43 women, 37 men, age = 18.2 ± 1.1 years, height = 175.8 ± 11.1 cm, body mass = 75.0 ± 16.9 kg) participated in this study. They were categorized into the healthy, coper, or unstable group by history of ankle sprains and score on the Cumberland Ankle Instability Tool.Main Outcome Measure(s):A musculoskeletal sonographic image of the ATFL was obtained from each ankle. Thickness of the ATFL was measured at the midpoint of the ligament between the attachments on the lateral malleolus and talus.Results:A group-by-limb interaction was evident (P = .038). The ATFLs of the injured limb for the coper group (2.20 ± 0.47 mm) and the injured limb for the unstable group (2.28 ± 0.53 mm) were thicker than the ATFL of the “injured” limb of the healthy group (1.95 ± 0.29 mm) at P = .015 and P = .015, respectively. No differences were seen in the uninjured limbs among groups.Conclusions:Because ATFL thicknesses of the healthy group's uninjured ankles were similar, we contend that lasting morphologic changes occurred in those with a previous injury to the ankle. Similar differences were seen between the injured limbs of the coper and unstable groups, so there must be another explanation for the sensations of instability and the reinjuries in the unstable group.
Stroke Awareness in Luxemburg: Deficit concerning Symptoms and Risk Factors
Authors: Droste Dirk W. , Safo Jacqueline , Metz René J. , Osada Nani 
Published: November 2014

BackgroundAwareness of stroke risk factors is important for stroke prevention. Knowledge of stroke symptoms and awareness regarding the necessity of seeking urgent stroke treatment are vital to provide rapid admission to a stroke unit. Data on this specific knowledge in Luxemburg are lacking.METHODSWe investigated 420 patients from the Department of Neurology and their relatives using a questionnaire. There were 44% men and 56% women; 25% were immigrants and 75% Luxemburgish nationals; 13% already had had a stroke or transient ischemic attack (TIA); and the mean age was 55 years ranging from 18 to 87 years.ResultsA total of 88% of participants knew that a stroke occurs in the head/brain. In all, 10% of participants did not know any symptom of a stroke. The most frequently quoted symptoms (>15%) were paralysis/weakness (36%), speech disorders (32%), cranial nerve deficit (16%), vertigo (15%), and visual disorders (15%). Sensory deficits were mentioned by only 4% of patients. Known risk factors (>15%) were smoking (40%), hypertension (32%), alcohol (32%), poor nutrition (28%), high cholesterol (26%), stress (23%), and lack of exercise (19%). Age (4%), diabetes (6%), carotid stenosis (2%), and heart disease (1%) were less frequently known. In all, 11% of participants did not know any risk factor of a stroke. A total of 89% of participants would correctly call the 112 (emergency phone number). The following groups were better informed: Luxemburgish nationals, younger people, and participants with higher education level. Stroke/TIA patients were better informed concerning stroke symptoms, but unfortunately not concerning how to react in the case of a stroke. There was no relevant gender difference.DiscussionAlthough most of the participants knew what to do in the case of a stroke, they did not know the relevant stroke symptoms and risk factors. Future campaigns should therefore focus on risk factors and symptoms, and should address immigrants, elderly persons, less-educated persons, and patients who had already suffered a stroke/TIA.
Stability of Equilibrium Solutions in Planar Hamiltonian Difference Systems
Authors: Carcamo Cristian , Vidal Claudio 
Published: November 2014

AbstractIn this paper, we study the stability in the Lyapunov sense of the equilibrium solutions of discrete or difference Hamiltonian systems in the plane. First, we perform a detailed study of linear Hamiltonian systems as a function of the parameters. In particular we analyze the regular and the degenerate cases. Next, we give a detailed study of the normal form associated with the linear Hamiltonian system. At the same time we obtain the conditions under which we can get stability (in linear approximation) of the equilibrium solution, classifying all the possible phase diagrams as a function of the parameters. After that, we study the stability of the equilibrium solutions of the first order difference system in the plane associated with mechanical Hamiltonian systems and Hamiltonian systems defined by cubic polynomials. Finally, we point out important diòerences with the continuous case.
Developing a Refractory Body for Kiln Building in Nigeria
Authors: Okonkwo IE 
Published: November 2014

Pottery today is the outcome of centuries of growth and its beginning in Nigeria stretches back into pre-historic times, a period without written history but potters have since learned much. Any potter who intends to make a living from this craft needs a kiln which combines reliability with economy. In the past thirty years, potters and entrepreneurs in Nigeria have set up many pottery studios. A good number of these pottery studios have not survived partly due to difficulties in procuring a functional kiln and sourcing for cheap and readily available fuels for firing. Firing is considered a crucial stage and the turning point in the process of pottery making. The researcher therefore considers it a challenge to develop a refractory body suitable for the construction of kerosene kiln. This research therefore intends to encourage potters to change their method and material utilization habit through local sourcing and experimentation with some of the locally available resources at hand.
Determinants of Perceived Students’ Academic Performance in Vocational Education in Tertiary Institutions in Lagos State
Authors: Ojo GO 
Published: November 2014

The study investigated determinants of perceived students' academic performance in vocational education in tertiary institutions in Lagos State, Nigeria. The study adopted survey research design. A total number of 310 respondents were selected from higher institutions in Lagos State using proportionate stratified sampling technique. The instrument used in the study was a set of questionnaire title Home- School Factors and Students' Academic Performance in Vocational Education Scale (HSFSAPVES). Five finding of the study revealed that there was a significant relationship between teachers' factors and perceived student's academic performance in vocational education courses. Also, there was a significant relationship between provisions of learning facilities and perceived students' academic performance invocational courses. It was discovered that there is significant relationship between students' factors and their perceived academic performance in vocational education courses. Based on the findings of the study, it is recommended that the teachers should be more motivated by ensuring participation in continuous training programmes. There should be improvement in the conditions of services and recruitment of more competent teachers. Also, government should endeavour to provide adequate learning facilities like computer, laboratory equipment, audio-visual materials and other learning facilities in order to sustain the interest of the students.
Psychological Determinants of Aggressive Behaviour among Adolescents in Secondary Schools in Anambra State
Authors: Izuchi MN , Anetoh BC 
Published: November 2014

The study was aimed at investigating the psychological determinants of aggressive behaviour among adolescents in secondary schools in Awka South L.G.A. of Anambra State. Three research questions and three null hypotheses guided the study. Expost facto design was adopted for the study. The population of the study comprised all the public secondary school students totalling 13296 while the sample size was 450 students drawn through simple random sampling technique. The instruments for data collection were aggressive behaviour scale (ABAS) and Psychological Assessment Scale (PAQ). The instruments were validated by experts in Educational Psychology, Measurement and Evaluation. The reliability coefficient of 0.84 was obtained for ABAS while reliability coefficients of 0.74, 0.85 and 0.88 were obtained for sections B, C and D of the PAQ respectively. The data obtained were analyzed using mean scores to answer the research questions and t-test to test the null hypotheses. The result obtained showed that stress significantly influenced aggressivebehaviour among secondary school adolescents while self-concept and locus of control did not significantly influence aggressive behaviour among them. Based on the findings of the study, recommendations were made which include that counselling psychologists should counsel the students to reduce or eliminate aggressive behaviour among them.Key: Psychological, Aggression, Adolescents, Behaviour