bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contactless electroreflectance spectroscopy of optical transitions in low dimensional semiconductor structures
Authors: Misiewicz J. , Kudrawiec R. 
Published: March 2012

AbstractThe authors present the application of contactless electroreflectance (CER) spectroscopy to study optical transitions in low dimensional semiconductor structures including quantum wells (QWs), step-like QWs, quantum dots (QDs), quantum dashes (QDashes), QDs and QDashes embedded in a QW, and QDashes coupled with a QW. For QWs optical transitions between the ground and excited states as well as optical transitions in QW barriers and step-like barriers have been clearly observed in CER spectra. Energies of these transitions have been compared with theoretical calculations and in this way the band structure has been determined for the investigated QWs. For QD and QDash structures optical transitions in QDs and QDashes as well as optical transitions in the wetting layer have been identified. For QDs and QDashes surrounded by a QW, in addition to energies of QD and QDash transitions, energies of optical transitions in the surrounded QW have been measured and the band structure has been determined for the surrounded QW. Finally some differences, which can be observed in CER and photo-reflectance spectra, have been presented and discussed for selected QW and QD structures.
Quantifying Extrusion Modification of LDPE with a Microcompounder
Authors: Li T. , Kuklisin K. , Auger J. , Nielsen J. , Lin W. 
Published: March 2012

Abstract
Processibility of LDPE is known to be sensitive to processing history. Significant changes in processibility and product properties can occur through repeated extrusion without detectable changes in molecular weight and molecular weight distribution. Such changes of LDPE rheology are simulated with DSM micro-compounder and characterized with the small angle oscillatory tests and the SER uni-axial extensional flow with a K-BKZ analysis.
Both the linear and the nonlinear rheology data suggest the major mechanism in the extrusion with the DSM micro-compounder is the reduction of the effects of long chain branching. The linear rheology analysis, along with GPC and NMR characterization confirms that the changes in the extrusion are not due to chemical crosslinking, though an increase in backbone molecular weight at extreme conditions is perceivable through the minor increase in molecular weight distribution, the increase in zero-shear viscosity and the decrease of melt index. The extensional rheology results, on the other hand, reveal the depression of the strain hardening with prolonged extrusion at 190 degree C or higher extrusion temperature. The stress growth data were evaluated with a K-BKZ constitutive with exponential damping function. The depression of strain hardening is well characterized with the strain hardening factor and the non-linear exponent beta as function of the extrusion conditions. The damping factor β is observed to be especially effective as the parameter to follow the depression of the strain hardening due to microcompounder extrusion. The microcompounder extrusion and the SER analysis with the K-BKZ analysis prove to be a new useful tool for simulating the shear modification of the LDPE.
Application of Dry Nano Powder Inverse Imprint Technology in Transferring and Replication of Micro Patterns
Authors: Weng Y.-J. 
Published: March 2012

Abstract
This research aims to develop a new dry nano powder inverse imprint technology, and probe into transferring and replication of micro patterns. First, a polydimethylsiloxane (PDMS) mould surface, with micro patterns of grating structures, undergo activation treatment with oxygen plasma in order to improve mould surface energy, and thus, spin coat photoresist onto the surface more easily. Then, the surface is heated to restore its hydrophobicity, and by means of nano powder, micro patterns are transfer printed onto the polymethylmethacrylate (PMMA). Research results show that dry nano powder soft coat transferring and forming technology can accurately reproduce the required patterns. In the experiment, gas assisted nano powder imprint technology is used to apply even pressure, coupled with even temperature rise for solidification, then, patterns can be effectively transfer printed and completely formed. Further, these patterns are in perfect contact with the PMMA surface, thus, greatly increasing the valid imprint area and enhancing transferring reproductiveness. The technology integrates technologies, such as, soft lithography, solidifying photoresist, and gas assisted pressure application, and is utilized to transfer print micro patterns in a grating structure, and thus, complete the transferring process of dry micro structure patterns.
Three-dimensional Numerical Study of the Mixing Behaviour of Twin-screw Elements
Authors: Ilinca F. , Hétu J.-F. 
Published: March 2012

Abstract
In this work the numerical modeling of the flow inside co-rotating twin-screw extruders is performed and solutions are analyzed to determine the mixing behavior of two screw elements: conveying and mixing elements. The flow around intermeshing screws is computed using an immersed boundary finite element method capable of dealing with complex moving solid boundaries. The flow is considered isothermal and the material behaves as a generalized non-Newtonian fluid. Because the viscosity depends on the shear rate, solutions will be shown for various rotation velocities of the screw. The 3D solutions are then analyzed in order to determine various parameters characterizing the flow mixing such as the residence time and the linear stretch. Residence time distribution inside the twin-screw extruder is first computed by using a particle tracking algorithm based on a fourth order Runge-Kutta method. A large number of particles are tracked inside the extruder and the resulting particle data is used to determine the distribution of the residence time and of the linear stretch. The spatial distribution of the residence time is also computed by solving a transport equation tracking the injection time of the polymer melt. The methodology shows important differences in the mixing behavior of the screw elements considered.
Three-Dimensional Observation on the Liquid Emptying Process from a Scaled-up Gravure Cell
Authors: Lee C.-C. , Hu S.-H. , Liu T.-J. , Tiu C. 
Published: March 2012

Abstract
The performance of gravure coating is strongly dependent on the break-up of the liquid bridge connecting the surfaces of the moving roller and gravure cell. The mechanism of the movement and subsequent break-up of the liquid bridge were studied experimentally using a three-dimensional flow visualization technique. Three stages of liquid motion were observed, and two characteristic lengths were defined to quantify the liquid pick-out and bridge break-up. The pick-out and break-up mechanisms were influenced by the capillary number, coating gap and the geometry of the gravure cell. A universal correlation between the pick-out and these variables was found.
The Rheological and Mechanical Properties of PVC-Lignin Blends
Authors: Liu F. , Xu K. , Chen M. , Cao D. 
Published: March 2012

Abstract
The rheological and mechanical properties of PVC-lignin blends were studied, and their alterations were investigated after lignin was treated with poly(ethyl acrylate-co-maleic anhydride). The addition of lignin changes the early rheological properties of the blend comparing with PVC control because the rigidity of lignin particles leads to more intensive shearing in the system, but has little effect on its rheology during the equilibrium period. The processing stability slightly decreases with the increase of lignin content in the blend. The mechanical properties of the blends are worse than that of PVC control. The rheological properties of the blends are little influenced after lignin is treated with polyacrylate, but the mechanical properties, especially toughness, are improved, and the maximum impact strength is 37.7% higher than that of PVC control.
Radio-Frequency Compression Molding of Recycled Commingled Polymers
Authors: Rios F. , Silverstein M. S. 
Published: March 2012

Abstract
The increasing consumption and resistance to natural decomposition of plastic materials has caused an ecological problem that is waiting for solutions, including economical recycling technologies. In this work, the properties of compression molded plastic boards made of commingled pellets of Polyethylene (PE) and Polyvinyl chloride (PVC), two incompatible widely used polymers, are investigated. The commingled pellets were mechanically mixed and flat boards with different ratios of PE and PVC were produced by compression molding, one set using radio frequency (RF) electromagnetic heating and the second using conventional conductive heating (CH). The main advantage of the RF system over the CH system is the much shorter heating time required to reach processing temperatures, making it an economically attractive alternative. However, the speed and intensity of the heat acting on the PVC in the RF process caused a reduction of the mechanical properties of the boards as a consequence of the degradation of the PVC. This problem was solved by the addition of process-specific additives, organic and inorganic, placed at the pellet's interface. The results of this work demonstrate that commingled plastics can be efficiently compression molded using radio frequency, providing an alternative to conventional compression molding using conductive heating.
Solving Injection Molded Part Warpage under Asymmetric Mold Cooling Conditions by Corrugated Variations in Part Thickness
Authors: Chen S. C. , Chang Y. , Huang S. T. 
Published: March 2012

AbstractIn this study, corrugated variations in part thickness designed to match the various mold temperature differences between the mold core and mold cavity sides, along with their effects on part warpage, were investigated. Part thickness was varied in a pitched manner and thickness reductions of 10%, 20%, 30%, and 40% of the original part thickness were implemented. The results show that when there is a mold temperature difference between core and cavity, using a corrugated thickness reduction design can greatly reduce or even eliminate part warpage. For a uniform thickness part molded under unbalanced cooling, the thermal neutral axis (where the maximum melt temperature is located) will deviate from the gap center toward the mold wall side with the higher temperature. Variation in thickness will pull the deviated thermal neutral axis back to the center line leading to a reduction in part warpage.
Effects of Pressure and Supercritical Fluid on Melt Viscosity of LDPE in Conventional and Microcellular Injection Molding
Authors: Hsu C.-L. , Turng L.-S. , Osswald T. A. , Rudolph N. , Dougherty E. , Gorton P. 
Published: March 2012

Abstract
In this study, the flow and rheological behaviors of low density polyethylene (LDPE) and single-phase LDPE/N2 polymer/gas solutions at various gas contents were measured using a high-pressure slit-die rheometer. The resulting rheology data of LDPE and LDPE/N2 were curve fit using the Cross–WLF model to obtain the seven material model constants, which were then used in the simulation of conventional and microcellular injection molding processes. The pressure effect on the shear viscosity of LDPE was also studied. The pressure dependency coefficient, D3, in the Cross–WLF model was determined by the use of simulation to best fit the experimental results. In addition, a three-dimensional plot of shear viscosity as a function of shear rate and pressure at various temperatures was constructed. Based on this three-dimensional viscosity–shear rate–temperature–pressure plot, the increase in viscosity due to the pressure effect was found to be more profound at high pressures, low temperatures, and low shear rates.
Influence of Scale Effect on Filling Behavior of Injection Molding by Visualization Method
Authors: Jiang K.-Y. , Tian J.-N. , Wang M.-J. , Ma J.-J. , Yu Z.-K. 
Published: March 2012

Abstract
For better understanding of thin-wall injection molding processes, a visualization injection mold and high speed camera were used to observe the dynamic filling behavior of melt in cavities with different thicknesses during the injection molding process. The impact of the scale effect on the melt-filling rate and filling imbalance in the multi-cavity were also studied. Results indicated that the filling behavior of the melt during the multi-cavity molding process was related to the cavity thickness. The experiment results can be used to describe the filling imbalance phenomenon during the injection molding process and to provide experimental evidence for precise injection molding technology at the micro scale.
Determination of Thermal Response on Mold Surface and Recommendation of Feasible Heating Time and Gas Flow Rate for a Circular Cavity by Gas Preheating
Authors: Chau S. W. , Lee Y. H. 
Published: March 2012

AbstractThis paper studies the thermal response on the mold surface of a circular cavity in the preheating process by high-temperature gas via a numerical approach, where the heat and mass transfer inside the cavity and mold are predicted by a two-fluid model. The dimensionless parameter group is identified from a dimensional analysis of the gas preheating problem. The correlations among dimensionless parameters are established by a least square method applied to the numerical predictions. The upper limit of the temperature rise on the cavity surface at a given gas flow rate is found approximately proportional to the square root of Q∗and h∗, respectively. The lower limit of gas flow rate to achieve a given temperature rise on the cavity surface is inversely proportional to h∗but grows with (Q∗)1.5. The first limiting line to describe the dependence of Q∗on t∗is independent of h∗and T∗, but the second one is governed by Q∗c. For reaching a specified temperature rise on the cavity surface, the growth in the thickness of thermal resistive layer reduces the required preheating time but increases the corresponding gas flow rate. The dependence of (t∗f, Q∗f) on the parameter group (T∗, h∗) is given in this study to obtain the reasonable combinations of (t∗f, Q∗f) based on the balance between the allowable preheating time and heating capacity.
Overall Control System for Injection Molding Process
Authors: Yang Y. , Yao K. , Gao F. 
Published: March 2012

Abstract
A multi-layer injection molding machine control system is proposed in this paper. The first layer, an advanced process parameter control layer, provides accurate and robust control of key process variables. The second layer consists of two modules, a profile setting layer determining the shapes of set-point profiles for the key process variables, to achieve an evenly distributed part quality along the flow directions; and a process fault detection and diagnoses system monitoring the operation of injection molding process. The third layer, a quality control layer, consists of a quantitative quality prediction model and a quality controller. This final layer provides a mechanism for closed-loop control of certain part quality. The related work that has been conducted on these three layers is discussed extensively in this paper, and the future work is introduced as well.
Tuberculomas in the Cavernous Sinus, Temporal Lobe and Basal Subarachnoid Spaces
Authors: Haque Md Raziul , Chowdhury Forhad Hossain , Islam Md Shafiqul , Kawsar Khandkar Ali , Haque AFM Momtazul 
Published: March 2012

Tuberculoma is not an uncommon lesion in intracranial space specially in developing world but tuberculoma in the cavernous sinus is very rare, and only less than ten cases have been reported in the literature, till today. Preoperative neuro-radiological features of such lesions may mimic neoplastic lesions of skull base and brain and post operative histopathological study brings the ultimate diagnosis. Here we report a rare case of cavernous sinus tuberculoma where tuberculomas were also in temporal lobe and Basal subarachnoid spaces (Right cavernous sinus, left temporal lobe, right sylvian fissure, basal cistern, interpeduncular cistern and prepontine cistern). DOI: http://dx.doi.org/10.3329/jom.v13i1.10056 JOM 2012; 13(1): 75-76 Tuberculoma is not an uncommon lesion in intracranial space specially in developing world but tuberculoma in the cavernous sinus is very rare, and only less than ten cases have been reported in the literature, till today. Preoperative neuro-radiological features of such lesions may mimic neoplastic lesions of skull base and brain and post operative histopathological study brings the ultimate diagnosis. Here we report a rare case of cavernous sinus tuberculoma where tuberculomas were also in temporal lobe and Basal subarachnoid spaces (Right cavernous sinus, left temporal lobe, right sylvian fissure, basal cistern, interpeduncular cistern and prepontine cistern). DOI: http://dx.doi.org/10.3329/jom.v13i1.10056 JOM 2012; 13(1): 75-76
Fibroadenoma with Foci of Infiltrating Ductal Carcinoma
Authors: Jahan Fauzia , Ghosh PK , Rahman Saidur , Khanam Rehana 
Published: March 2012

Fibroadenoma is a biphasic tumor of breast with stromal and epithelial components. It is a very common benign tumor among young female. Malignant transformation in a fibroadenoma is uncommon. We report a case of an elderly patient with bilateral fibroadenomas harboring foci of invasive ductal carcinoma. The intent of this presentation is to increase general awareness as to the existence of carcinomas arising in fibroadenomas and also to actively discourage the practice of rendering gross pathological diagnoses of fibroadenomas. DOI: http://dx.doi.org/10.3329/jom.v13i1.10088 JOM 2012; 13(1): 115-117
Systèmes agraires et facettes écologiques au Karnataka (Inde du Sud) : portraits d'une organisation humaine autour d'un gradient bioclimatique exceptionnel / Land systems and land use in Karnataka, South India : patterns of human adaptation to a steep environmental gradient
Authors: Gunnell Yanni 
Published: March 2012

Le fort gradient bioclimatique, qui caractérise le revers des Ghats occidentaux
(Karnataka, Inde méridionale), impose des contraintes physiques qui influencent pour une large part la géographie agraire et les calendriers agricoles de ces hautes terres cristallines. Par référence, en toile de fond, à quelques exemples africains, cette étude d'écologie humaine montre comment l'identité agraire de chacune des régions naturelles définies s'est construite, et s'articule encore étroitement, sur les régimes pluviométriques et le canevas des modelés et des sols, et comment l'organisation caténaire de ces agrosystèmes contrastés institue tantôt des complémentarités économiques, tantôt une certaine autosuffisance.
Marchands ambulants, réglementation et police à Bruxelles au XIXe siècle
Authors: Geyzen Anneke 
Published: March 2012

Résumé En 1875, les autorités urbaines de Bruxelles rédigèrent un rapport concernant l’opinion publique hostile face aux échoppes mobiles, lors de la rédaction d’un règlement sur le colportage. Les autorités conclurent que maintes villes européennes, confrontées au danger supposé de désordre de l’espace public, lançaient une politique répressive vis-à-vis du commerce ambulant. L’article vise à analyser le processus de décision sociopolitique concernant le commerce ambulant à Bruxelles au XIX e siècle, en étudiant les lois, les intentions et les effets sur les marchands ambulants. Sur la base des archives policières et de documents administratifs (notamment le Bulletin communal de la Ville de Bruxelles ), l’article se propose d’explorer les questions suivantes : Quelles furent les mesures prises afin – ou non – d’abolir ou prohiber le commerce ambulant ? Quels en furent les motifs ? La politique sociale fut-elle efficace ? La politique changea-t-elle au cours du XIX e siècle ? Finalement, l’article tente de comprendre si l’idée d’un espace public net et ordonné, dans lequel les marchands ambulants n’avaient pas leur place, guida les autorités urbaines de Bruxelles.
Comment évaluer un modèle numérique de climat ?
Authors: Guillemot Hélène 
Published: March 2012

La validité et la légitimité scientifiques des modèles numériques de climat et de leurs prévisions des changements climatiques sont basées sur les confrontations entre les simulations et les données d’observation. Les validations ou plutôt les évaluations des modèles par les données constituent la majeure partie du travail des modélisateurs. Il n’y a pas de méthodologie générale d’évaluation des modèles ; on observe une grande variété de pratiques car on ne valide pas un modèle en général mais sa capacité à rendre compte d’un phénomène climatique particulier. À partir des pratiques scientifiques observées dans les deux principaux centres de recherche qui développent et utilisent des modèles de climat en France, cet article donne quelques exemples de la façon dont les chercheurs établissent des connexions, des « dialogues » entre modèles et données qui ne se réduisent pas à la validation des premiers par les secondes. L’analyse de ces pratiques nous permettra de tirer quelques leçons d’« épistémologie bottom‑up » de modélisation du climat.
Connaissances et cours d’expérience
Authors: Dieumegard Gilles 
Published: March 2012

La méthode « cours d’action » permet une étude globale de l’activité des apprenants et de la dynamique de leurs connaissances dans les situations d’éducation et de formation. Elle permet de produire des descriptions rendant compte de leur expérience. Basée sur le paradigme de l’énaction, elle exclut une conception représentationnelle des connaissances, pour en privilégier une conception expérientielle : elles sont considérées en tant qu’expériences de familiarité, de généralité, de transcendance de l’ici et maintenant liée à des expériences précédemment rencontrées.Pour cela, la formulation des connaissances sous forme de propositions est critiquable : elle offre une pluralité de descriptions qui n’est pas suffisamment contrôlée, et risque d’introduire implicitement une conception représentationnelle en contradiction avec les présupposés théoriques adoptés. Aussi est proposée une grammaire minimale contraignant la formulation des connaissances. Elle associe la reconnaissance de totalités familières (Gestalt-type) et l’énaction de propriétés typiques investies dans l’action ou le raisonnement.Cette grammaire permet de rendre compte de l’ensemble des connaissances en jeu du point de vue des apprenants.
Les « passions cognitives » ou la dimension rebelle du connaître en régime de passion
Authors: Roux Jacques , Charvolin Florian , Dumain Aurélie 
Published: March 2012

L’article soutient que la notion de « passions cognitives », par sa sémantique multiple, est heuristiquement puissante. Elle porte une tension d’un enrôlement de la connaissance par une force irrésistible qui emporte avec elle toute possibilité de raisonnement ; la cognition suppose au contraire une forme de « relaxe » dans la posture connaissante. L’article montre la radicalité potentielle de la notion en la confrontant à différentes enquêtes de terrain. Il s’agit de réintroduire le tabou de la passion dans l’étude de la connaissance en train de se faire, avec ses épreuves cognitives et affectives, l’engagement volontaire et l’attachement à l’objet étudié, la participation à des communautés de passionnés ou de contre-passionnés, l’articulation des sujets de passion et des sujets de connaissance, la dérivation des attributs de la connaissance depuis la passion, l’épistémologie d’un « connaître avec et en situation » et pas seulement « sur et à distance », la question des grands amateurs et celle de la production de connaissance dans des passions publiques.