bluuebunny/crossref_metadata_2025 huggingface dataset:
Combinatorial Searching for Ni-Nb-Zr Amorphous Alloys as Glass Lens Molding Die Materials
Authors: Sakurai Junpei , Abe Mitsuhiro , Ando Masayuki , Hata Seiichi
Published: September 2010

This paper presents a search for Ni-Nb-Zr amorphous alloys for application as glass lens molding die materials. To efficiently screen candidate materials, we employed the combinatorial method partially to evaluate thermal stability. First, compositionally spread Ni-Nb-Zr libraries were fabricated by combinatorial arc plasma deposition (CAPD). In order to evaluate the high thermal stability, Ni-Nb-Zr amorphous samples in the libraries were annealed at 723K, the molding temperature for glass lens, for various times in vacuum. Phases in the annealed samples were identified by X-ray diffraction. From XRD identification, candidate amorphous samples with high thermal stabilities were screened. Sputtered samples with the same compositions as the candidate amorphous samples were then fabricated. Other desired properties for glass lens molding die materials, such as mechanical strength, machinability and anti-sticking properties, were evaluated. These investigations revealed Ni36Nb39Zr25 to be a suitable material for a new glass lens molding die. This material exhibited a high fracture stress f of 1.3 GPa, good heat resistance, good machinability, and excellent anti-sticking properties to molten glass.
Micro Texturing of Polycarbonate Plate with Ion Beam Irradiation and its Friction Properties in Water
Authors: Umehara Noritsugu , Demizu Yasuhito , Nishio Junichi , Tokoroyama Takayuki
Published: September 2010

In order to fabricate micro textured polymer plate, some kinds of ions were irradiated to the substrate by using an Electron Cyclotron Resonance (ECR) ion shower apparatus. Surface morphology of specimens was observed by SEM, and measured by AFM. We observed a lot of micro polymer brushes on the substrate. The surface roughness of untreated specimen increased and reached to 248 nm by N2 ion irradiation. We have used Argon, Nitrogen and Oxygen ions. Oxygen ion shows more effective to etch than the other two ions. Also we measured the contact angle of water on the surface of specimens with optical microscope. The contact angle of untreated specimen decreased and reached to 8 degree by N and O ion irradiation. After the irradiation, we conducted sliding friction test between ion irradiated polycarbonate slider and flat polycarbonate specimen. It was observed that friction coefficient of ion irradiated polycarbonate slider showed lower friction than flat polycarbonate specimen under mixed lubrication condition in water.
Tribology of Micro Milled Surfaces
Authors: Twardy S. , Riemer Otmann , Brinksmeier Ekkard
Published: September 2010

Micro milling is an appropriate technology for the flexible production of precise micro molds with complex shapes for metal forming processes (e.g. micro deep drawing). Besides high form accuracy micro ball end milling also provides a specific surface topography which can enhance the tribological behavior during the forming processes.
This paper is focusing on the tribological behavior of micro structured surfaces generated by micro milling compared to smooth surfaces. The coefficient of friction was investigated on a pin-on-disc test stand for different materials. The results of the tribological tests suggest a relationship between micro structure and coefficient of friction. Finally, the correlations between machining parameters and tribological behavior will be discussed.
Room Temperature Processed Hard Easy Clean Coating Using Ammonia Treatment
Authors: Zhang Xiao , Qian Min , Liu Yu Chan , Xie Hong
Published: September 2010

In this paper we report the fabrication of hydrophobic hard coatings using sol-gel processing and cured at room temperature by an ammonia-assisted process. The coating thickness can be tuned from several hundreds of nanometer to several microns. These coatings show both high transparency (better than PMMA or glass substrates) and high hardness (pencil hardness 2H-4H on PMMA). The coatings are very smooth with surface roughness Ra less than 2 nm for coatings with different thicknesses from 200 nm to 2 m. The water contact angle (WCA) of the coating is about 115 to 120o and the sliding angle for a 20 l water drop is less than 10o. The advantage of this process is the ease for larger area application and especially suitable for plastic surface treatment due to the low temperature curing process.
Microstructural Changes during Precision Machining of Thin Substrates
Authors: Saptaji K. , Sathyan Subbiah
Published: September 2010

This paper reports investigations in machining of thin substrates with thickness less than 100m. The machining process induces severe plastic deformation through the thickness of the machined thin workpiece due to the high ratio of the depth of cut to workpiece thickness. The diamond face turning is used to machine thin workpieces down to a thickness less than 100m. The microstructure of the machined sample is studied and x-ray diffraction used to observe the crystallographic orientation / texture. The microstructures of the thin machined workpieces are seen to become more random, denser, and finer with the shape of the grains less elongated as compare to the bulk and thick machined sample. The x-ray diffraction analyses indicate that machining of thin substrates changes the texture or orientation. Different deformation mechanisms may occur when machining thin workpiece especially at thicknesses below 100m.
Economic Viability of Nickel Recovery from Waste Catalyst
Authors: Yang Q.Z. , Ng R.S. , Qi G.J. , Low H.C. , Zhang Y.P.
Published: September 2010

This paper investigates the economic viability of a closed-loop process for nickel recovery from roasted catalytic wastes. The effects of process parameters and market factors that drive the bottom-line profitability of nickel recovery are identified and analyzed using a cost and revenue evaluation model developed in the study. The main factors include the production batch size, material cost, and nickel selling price. With a nickel market value higher than S$18.85 per kg, the process is economically viable even with a batch size as small as 50 kg/batch. Given that the current nickel selling price at the metal exchange market has reached around S$24-28/kg, the economic feasibility of the process is confirmed.
Qualitative and Quantitative Analysis of Boron Content Precipitates by FEG-SEM and EDS Methods
Authors: Dénes Éva , Tóth Attila Lajos , Enikő-Réka Fábián
Published: September 2010

The effect of the boron in steels is widely known as an element enhancing hardenability, but its role can also be related to the enamelability of steels. While the improvement of the hardenability is due to the solute boron, in the case of enameling grade steels the boron should be kept in form of precipitates 1. The hydrogen accumulated during processing and enameling diffuses to the metal/enamel interface and lead to the formation of the so called fish-scale failure. To prevent this it is needed an adequate type, number and dimension of precipitates which act as hydrogen traps hinder the free diffusion of the hydrogen in steel. The paper deals with the possibilities of investigation by scanning electron microscopy of the boron containing precipitates in the low carbon Al-killed steels apt for two side enamelling.
Modeling of Shape Memory Alloy Actuators Using Matlab and dSpace Platform
Authors: Cosma Ioan Adrian , Măties Vistrian , Lapusan Ciprian , Mîndru Rares Ciprian
Published: September 2010

The aim of the paper is to describe an approach for modeling the dynamic behavior of a positioning system actuated by two shape memory alloy springs, placed in opposition. The mathematical analysis of the system in order to develop the dynamic model is difficult in this case because of the unknown parameters within the dynamic equations (thermodynamics, change in austenite fraction) and therefore a new approach is presented. Thus, a positioning system is considered, and its behavior is determined using Matlab Software, D-space platform and an optical sensor, which analyses the position/velocity of the moving cart. The dynamic model of the system is determined in order to develop a further model based control technique. The model is generated using system identification toolbox within Matlab and input and output (response) of the considered system.
The Design Approach of Human Prostheses and Intelligent Robot End Effectors Based on Mechatronic Philosophy
Authors: Dolga Valer , Dolga Lia
Published: September 2010

The grip operation requires grippers as end effectors, behaving analogous to the human grasping organ, irrespectively if it is performed in robotic systems or in arm prostheses. Improving grippers design involves a biomechanical analysis of the human prehensile organ. The authors evaluated the complexity of both industrial and medical grippers and proposed a common design method, based on the mechatronic philosophy. The aimed upshot might be a better device, with improved functionality, a cost cutback and a more efficient design endeavour.
Fuzzy Reasoning in Mobile Robots Control
Authors: Dumitriu Adrian
Published: September 2010

The paper presents some author’s experiments carried out within the frame of a research project and destined to endow mobile robot modules with small and simple sensors to support navigation. Range sensors, proximity sensors and acceleration sensors in MEMS technology were used and Fuzzy logic has proved to be an adequate tool for sensor data integration. A Fuzzy controller has been developed and tested on a mobile robot moving on rough terrain.
Development of Riding Robot System for Entertainment and Healthcare Service
Authors: Lim Mee Seub , Park Hyung Bae , Lim Joon Hong
Published: September 2010

This paper describes the riding robot system named by "RideBot" which is a riding robot like as a horse. In order to simulate the riding motions, we developed the saddle mechanism which can generate 3 DOF motions including pitch, roll, and bounce movement, and also we controlled the riding motions and the intention of horseman. To generate the riding motions with the bodily sensation, we developed Novel Washout Filter and the algorithms for motion control. And also, we developed some health care service for the health care of horseman. A body state index was proposed that evaluates the personal health state from both the measured physiological variables and the surveyed questions. The physiological variables such as weight, blood pressure, heart rate variability (HRV), accelerated state photoplethysmograph(APG), body fat, and happiness index were measured by the specially designed bio-handle system and survey questions. The efficiency of the proposed ride robot is evaluated in the experiments
Automatic Page Turner
Authors: Aluţei Alexandra Maria , Chetran Beniamin Vasile , Lungu Ion , Mândru Dan
Published: September 2010

This paper presents the development of an Assistive Technology representative product: an automatic page turner system, designed for persons with issues like multiple sclerosis, Parkinson’s disease and other various disabilities that involve the motor functions of the upper limbs. Firstly, the authors emphasize specific features of Assistive Technology and analyse the most important functional aspects concerning different types of page turner devices. The proposed page turner system is based on a four-bar mechanism. Design aspects from the constructive and functional points of view are exposed and the developed prototype is described.
Modeling of the Control Algorithms in Case of a Self Reconfiguring Mobile Robotic System
Authors: Raducu Mihai George , Nitulescu Mircea
Published: September 2010

Self reconfiguring robots are complex robotic systems composed of a finite number of modules, where each module of the system is considered to be a simple agent. Based on this con¬text, the reconfi¬guration represents the process of re-arranging each agent of the robotic system in order to have a working system. One versatile method to determine the most adequate movement and reconfiguration algorithms can be done us¬ing modeling methods and tools. Using this approach, the control algorithms necessary to drive such a system can be modeled, tested and implemented in an embedded system much easier than in a classical approach. This paper presents the case of a self reconfiguring robot for which, a reconfiguration algorithm and a movement algorithm were determined, analyzed, tested and validated.
Automated Test Bench for Study of the Fuel Injection Process
Authors: Barabás István , Todoruţ Ioan Adrian , Kocsis Levente Botond , Băldean Doru Laurean
Published: September 2010

The paper presents the design, implementation and use of an automatic test bench for the injection process, using an economical solution for recording successive images of a fuel jet injected into a chamber pressurized with nitrogen at ambient temperature, with a camera. Injection pressure can be adjusted with high precision using a closed loop PID control (closed loop). The test bench operation is synchronized by a computer-assisted system. Experimental results are also summarized for research of the diesel injection process.
Modular Robotic System for Moving Inside of Pipelines - Part 1
Authors: Tatar Mihai Olimpiu , Alutei Adrian , Cirebea Claudiu
Published: September 2010

In this paper, the authors present an in-pipe modular robotic system for inspection inside pipes with diameters ranged between 140 and 200 mm. The paper describes the components used for building the modules and the actuating systems.
Java Simulator for Quadruped Walking Robot
Authors: Vatau Steliana , Ciupe Valentin , Maniu Inocentiu
Published: September 2010

With advances in science and technology, the interest to study the animals walking has developed the demand for building the legged robots. Physics-based simulation and control of quadruped locomotion is difficult because quadrupeds are unstable, under actuated, high-dimensional dynamical systems. We develop a simple control strategy that can be used to generate a large variety of gaits and styles in real-time, including walking in all directions (forwards, backwards, sideways, turning). The application named JQuadRobot is developed in Java and Java3D API. A Graphical User Interface and a simulator for a custom quadruped leg's robot and the main features of the interface are presented in this paper. This application is developed in Java and is essential in a development motion for legged robot. The friendly interface, allows any user to define and test movements for this robot. The cross-platform capability was the first reason to choose Java language for developing this application.
Specific Mechanisms for Construction Mobile Robots
Authors: Bruja Adrian , Dima Marian , Frâncu Cătălin
Published: September 2010

The paper presents research results on the development of specific steering and vertical locus orientation mechanisms for mobile construction robots.
Inhibition of NF-κB Signaling in Human Dendritic Cells by the Enteropathogenic Escherichia coli Effector Protein NleE
Authors: Vossenkämper Anna , Marchès Olivier , Fairclough Peter D. , Warnes Gary , Stagg Andrew J. , Lindsay James O. , Evans Paul C. , Luong Le A. , Croft Nicholas M. , Naik Sandhia , Frankel Gad , MacDonald Thomas T.
Published: September 2010

Intestinal dendritic cells (DCs) send processes between epithelial cells into the gut lumen to sample pathogens. Noninvasive enteropathogenic Escherichia coli (EPEC) colonize the gut using a type three secretion system (T3SS) to inject effector proteins into epithelial cells. We hypothesized that EPEC might also inject proteins into DC processes to dampen immune recognition. Using a T3SS-linked fluorescence resonance energy transfer-based system we show that EPEC injects effectors into in vitro grown human myeloid DCs. Injected cells emit a blue signal due to cleavage of the green fluorescence resonance energy transfer-based substrate CCF2/AM by β-lactamase. When cultured with a mutant EPEC unable to translocate effector proteins, myeloid DCs show rapid activation of NF-κB, secrete large amounts of proinflammatory cytokines and increase expression of CD80, CD83, and CD86, whereas wild-type EPEC barely elicits cytokine production and shuts off nuclear translocation of NF-κB p65. By deleting effector protein genes, we identified NleE as being critical for this effect. Expression of NleE in HeLa cells completely prevented nuclear p65 accumulation in response to IL1-β, and luciferase production in an NF-κB reporter cell line. DCs cocultured with wild-type EPEC or NleE-complemented strains were less potent at inducing MLR. EPEC was also able to inject effectors into DCs sending processes through model gut epithelium in a transwell system and into Peyer’s patch myeloid DCs. Thus, EPEC translocate effectors into human DCs to dampen the inflammatory response elicited by its own pathogen-associated molecular patterns.
Chemoattractant Receptors and Lymphocyte Egress from Extralymphoid Tissue: Changing Requirements during the Course of Inflammation
Authors: Brown Meghan N. , Fintushel Sarah R. , Lee Michael H. , Jennrich Silke , Geherin Skye A. , Hay John B. , Butcher Eugene C. , Debes Gudrun F.
Published: September 2010

Memory/effector T cells traffic efficiently through extralymphoid tissues, entering from the blood and leaving via the afferent lymph. During inflammation, T cell traffic into the affected tissue dramatically increases; however, the dynamics and mechanisms of T cell exit from inflamed tissues are poorly characterized. In this study, we show, using both a mouse and a sheep model, that large numbers of lymphocytes leave the chronically inflamed skin. Many T cells capable of producing IFN-γ and IL-17 also entered the draining afferent lymph, demonstrating that memory/effector T cells egress from sites of inflammation. Whereas efficient egress from acutely inflamed skin required lymphocyte-expressed CCR7, chronic inflammation promoted significant CCR7-independent exit as well. Lymphocyte exit at late time points of inflammation was sensitive to pertussis toxin but was only partially affected by the drug FTY720, implying the contribution of alternative chemoattractant receptors other than spingosine 1-phosphate receptor 1. Our data show that CCR7 is an important receptor for lymphocyte egress from both resting and inflamed extralymphoid tissues, but that alternative exit receptors come into play during chronic inflammation.
Responses against a Subdominant CD8+ T Cell Epitope Protect against Immunopathology Caused by a Dominant Epitope
Authors: Ruckwardt Tracy J. , Luongo Cindy , Malloy Allison M. W. , Liu Jie , Chen Man , Collins Peter L. , Graham Barney S.
Published: September 2010

CD8+ T cell responses are critical for the control of virus infections. Following infection, epitope-specific responses establish an unpredictable but reproducible pattern of dominance that is dictated by a large number of both positive and negative factors. Immunodomination, or diminution of subdominant epitope-specific responses by dominant epitopes, can play a substantial role in the establishment of epitope hierarchy. To determine the role of a dominant (KdM282–90) and a subdominant (DbM187–195) epitope of respiratory syncytial virus in viral control and immunodomination, MHC-binding anchor residues in the two epitopes were mutated individually in recombinant infectious viruses, greatly reducing or deleting the epitope-specific CD8+ T cell responses. Neither mutation negatively affected viral clearance in mice, and compensation by the unmutated epitope was seen in both cases, whereas compensation by five other subdominant epitopes was minimal. Mutation of the dominant KdM282–90 response resulted in effective viral clearance by the subdominant epitope with less illness, whereas mutation of the subdominant DbM187–195 response resulted in overcompensation of the already dominant KdM282–90 epitope, and increased severity of illness. Increased illness was associated with poor functionality of the abundant population of CD8+ T cells specific to the dominant KdM282–90 epitope, as measured by the percentage and magnitude of IFN-γ production. These data demonstrate efficient viral clearance, and a protective effect of subdominant CD8+ T cell responses.
Novel Zirconia–Alumina Nanocomposites Combining High Strength and Toughness
Authors: Gadow Rainer , Kern Frank
Published: September 2010

Alumina toughened zirconia (ATZ) composites, combining a matrix of tetragonal zirconia polycrystals (TZP) and an alumina dispersion, are known for their high strength, toughness, and abrasion resistance. Depending on the type of stabilizing oxide in TZP the materials can be tailored to be either extremely strong (Y–TZP) or extremely tough (Ce–TZP) with a considerable cutback in the complementary property. Novel nanocomposite ATZ materials consisting of TZP co‐stabilized by neodymium and yttrium oxide (Nd–Y–TZP) combined with a reinforcement of 0–40 vol% alumina were produced to achieve high bending strength of 1200–1500 MPa at a toughness of 8–12 MPa·√m. TZP was produced by coating monoclinic nanopowder with 1.5 mol% yttria and 1.5 mol% neodymia. The powder was then blended with submicron size alumina and consolidated by hot pressing. Mechanical and microstructural properties were investigated.
Combinatorial and High‐Throughput Screening of Biomaterials
Authors: Simon Carl G. , Lin‐Gibson Sheng
Published: September 2010

Combinatorial and high‐throughput methods have been increasingly used to accelerate research and development of new biomaterials. These methods involve creating miniaturized libraries that contain many specimens in one sample in the form of gradients or arrays, followed by automated data collection and analysis. This article reviews recent advances in utilizing combinatorial and high‐throughput methods to better understand cell–material interactions, particularly highlighting our efforts at the NIST Polymers Division. Specifically, fabrication techniques to generate controlled surfaces (2D) and 3D cell environments (tissue engineering scaffolds) as well as methods to characterize and analyze material properties and cell–material interactions are described. In conclusion, additional opportunities for combinatorial methods for biomaterials research are noted, including streamlined sample fabrication and characterization, appropriate and automated bioassays, and data analysis.
Dextromethorphan Plus Ultra Low‐Dose Quinidine Reduces Pseudobulbar Affect
Authors: Pioro Erik P. , Brooks Benjamin Rix , Cummings Jeffrey , Schiffer Randolph , Thisted Ronald A. , Wynn Daniel , Hepner Adrian , Kaye Randall
Published: September 2010

Objective

To evaluate dextromethorphan combined with ultra low‐dose quinidine (DMq) for treating pseudobulbar affect (PBA) in patients with amyotrophic lateral sclerosis (ALS) or multiple sclerosis (MS).

Methods

In a 12‐week randomized, double‐blind trial, ALS and MS patients with clinically significant PBA (a baseline score ≥13 on the Center for Neurologic Studies–Lability Scale [CNS‐LS]) were maintained, twice daily, on placebo, DMq at 30/10mg (DMq‐30), or DMq at 20/10mg (DMq‐20).

Results

In 326 randomized patients (of whom 283, or 86.8%, completed the study), the PBA‐episode daily rate was 46.9% (p< 0.0001) lower for DMq‐30 than for placebo and 49.0% (p< 0.0001) lower for DMq‐20 than for placebo by longitudinal negative binomial regression, the prespecified primary analysis. Mean CNS‐LS scores decreased by 8.2 points for DMq‐30 and 8.2 for DMq‐20, vs 5.7 for placebo (p= 0.0002 andp= 0.0113, respectively). Other endpoints showing statistically significant DMq benefit included, for both dosage levels, the likelihood of PBA remission during the final 14 days and, for the higher dosage, improvement on measures of social functioning and mental health. Both dosages were safe and well tolerated.

Interpretation

DMq markedly reduced PBA frequency and severity, decreasing the condition's detrimental impact on a patient's life, with satisfactory safety and high tolerability. The findings expand the clinical evidence that DMq may be an important treatment for patients suffering from the socially debilitating symptoms of PBA. Ann Neurol 2010
RYR1 mutations are a common cause of congenital myopathies with central nuclei
Authors: Wilmshurst J.M. , Lillis S. , Zhou H. , Pillay K. , Henderson H. , Kress W. , Müller C.R. , Ndondo A. , Cloke V. , Cullup T. , Bertini E. , Boennemann C. , Straub V. , Quinlivan R. , Dowling J.J. , Al‐ Sarraj S. , Treves S. , Abbs S. , Manzur A.Y. , Sewry C.A. , Muntoni F. , Jungbluth H.
Published: September 2010

Objective

Centronuclear myopathy (CNM) is a rare congenital myopathy characterized by prominence of central nuclei on muscle biopsy. CNM has been associated with mutations in MTM1, DNM2, and BIN1 but many cases remain genetically unresolved. RYR1 encodes the principal sarcoplasmic reticulum calcium release channel and has been implicated in various congenital myopathies. We investigated whether RYR1 mutations cause CNM.

Methods

We sequenced the entire RYR1 coding sequence in 24 patients with a diagnosis of CNM from South Africa (n = 14) and Europe (n = 10) and identified mutations in 17 patients. The most common genotypes featured compound heterozygosity for RYR1 missense mutations and mutations resulting in reduced protein expression, including intronic splice site and frameshift mutations.

Results

The high incidence in South African patients (n = 12/14) in conjunction with recurrent RYR1 mutations associated with common haplotypes suggested the presence of founder effects. In addition to central nuclei, prominent histopathological findings included (often multiple) internalized nuclei and type 1 fiber predominance and hypotrophy with relative type 2 hypertrophy. Although cores were not typically seen on oxidative stains, electron microscopy revealed subtle abnormalities in most cases. External ophthalmoplegia, proximal weakness, and bulbar involvement were prominent clinical findings.

Interpretation

Our findings expand the range of RYR1‐related phenotypes and suggest RYR1 mutations as a common cause of congenital myopathies with central nuclei. Corresponding to recent observations in X‐linked CNM, these findings indicate disturbed assembly and/or malfunction of the excitation‐contraction machinery as a key mechanism in CNM and related myopathies.ANN NEUROL 2010
Thermal degradation behavior of low‐halogen flame retardant PC/PPFBS/PDMS
Authors: Dang Xiaorong , Bai Xin , Zhang Yong
Published: September 2010

Flame retardant polycarbonate (FRPC) with 0.2 wt % additives of potassium perfluorbutane sulfonate and polydimethylsiloxane was found to achieve V‐0 rate at 1.6 mm thickness without significantly affecting the mechanical properties of PC. Condensed aromatic bonds with a small amount of SiO bonds were found in the UL‐94 burning residues tested by FTIR spectra. A compact char layer with cavities inside was formed on the surface of the sample during the rapid decomposition of FRPC, and the concentration of Si was found to be much higher inside the surface of the char layer than that outside the surface analyzed by SEM‐EDX, which was related to the synergistic effects of the two flame retardants of PPFBS and PDMS. A schematic diagram was designed to describe the mechanism of the FRPC. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Poly(acrylic acid–sodium styrene sulfonate) organogels: Preparation, characterization, and alcohol superabsorbency
Authors: Kabiri K. , Azizi A. , Zohuriaan‐Mehr M. J. , Marandi G. Bagheri , Bouhendi H.
Published: September 2010

Polymeric organogels based on acrylic acid and sodium styrene sulfonate (SSS) were synthesized and characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, dynamic mechanical thermal analysis (DMTA), and rheometrical analyses. The organogels exhibited medium alcohol absorbency because of counterion binding that formed in solvents with low dielectric constants. After acid treatment, the possibility of counterion binding was decreased, and the organogels achieved superabsorbency in alcohols, for example, about 80 and 50 g/g in methanol and ethanol, respectively. The superabsorbency was also measured in higher alcohols (i.e., n‐propanol and isopropyl alcohol) and polyols (i.e., ethylene glycol, propylene glycol, 1,3‐propanediol, and glycerol). The dielectric constant, viscosity, and structural features of the alcohols were investigated as important parameters determining the alcohol superabsorbency. DMTA of dried samples showed two glass‐transition temperatures (Tg's), that is, the matrix Tg and the complex Tg, which increased with increasing SSS content. The tan δ peak intensity increased after the acid treatment. With increasing SSS, the storage modulus of the dried gel increased; whereas that of the rheometrically measured hydrated gel decreased. Tan δ decreased with increasing SSS because of enhanced counterion binding. These alcohol‐specific superabsorbing organogels are suggested as excellent candidates for the manufacture of products with high alcohol contents, such as hand sanitizers and fuel gels. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Characterization and modeling of sintering of polymer particles
Authors: Asgarpour M. , Bakir F. , Khelladi S. , Khavandi A. , Tcharkhtchi A.
Published: September 2010

An experimental study of simultaneous sintering of several particles has been carried out using spherical polymer grains. Considering rotational molding condition, coalescence of several grains in contact, happens simultaneously on internal surface of the mould. Theoretical model based on the effect of surface tension and viscosity can accurately predict the coalescence of a pairs of grains. However, it was observed in this study that coalescence rate changes with presence of neighboring grains and their position and the theoretical model proposed for two grains, is not able to predict the coalescence rate of mutli‐grains. Based on this finding, we have modified this model with taking into account the effect of neighboring particles in the sintering rate of multi‐grains. Obtained modified model is capable of predicting the multi‐grains sintering rate observed in this study. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Fabrication of Microspheres from Phthalimide‐Substituted Porphyrin Derivatives
Authors: Ozawa Hiroaki , Kawao Masahiro , Nagata Toshi , Uno Shigeyasu , Nakazato Kazuo
Published: September 2010

Microspheres were fabricated from phthalimide‐substituted porphyrin derivatives. Microscopic analysis showed that the structures of the supramolecular assemblies synthesized in the present study were spherical, with diameters in the sub‐micrometer to micrometer range. The size of the microspheres could be controlled by changing the concentration of the casting solution. The spectroscopic properties of the microspheres were measured to determine the influence of their structural components. Thermal studies indicated that the temperature at which these structures became unstable was lower than the bulk melting point. During I–V measurements on devices composed of these microspheres, it was found that the current increased upon light irradiation, and the characteristic photoresponse properties of these devices were reproducible.
L'hydrogénation et la polymérisation de l'éthylène, du propylène et de l'acétylène photosensibilisés par la vapeur de mercure
Authors: Vanhaeren L. , Jungers J. C.
Published: September 2010

L'hydrogénation photosensibilisée de l'éthylène se produit à une vitesse qui croît jusqu' à une limite avec la pression en hydrogène mais est indépendante, dans le domaine étudié, de la pression en éthylène. Le mercure exerce une influence notable sur la réaction. Les mélanges contenant un excès de mercure rélèvent un coefficient thermique faible et fournissent principalement du butane; les mélanges à peine saturés ont un coefficient thermique plus important et fournissent un mélange complexe.

Les mesures faites en incorporant à l'éthylène de faibles quantités d'hydrogène. d'acétylène ou d'un mélange des deux n'ont pas permis de confirmer l'hypothèse suivant laquelle la polymérisation de l'éthylène se déroulerait avec production intermédiaire d'acétylène.

L'hydrogénation du propylène offre avec celle de l'éthylène de grandes similitudes; cependant le produit de la réaction est toujours un mélange très complexe. La polymérisation du propylène se poursuit avec une vitesse constante et sans augmentation initiale de pression.

La vitesse d'hydrogénation de l'acétylène croît en fonction de la pression en acétylène et en hydrogène. Même avec un excès d'hydrogène (20:1) la saturation n'est jamais complète; la réaction qui fournit peu de produits volatils s'accompagne d'une polymérisation notable.

En vue de déterminer les rendements quantiques relatits de Les réactions nous avons mesuré, dans les mêmes conditions opératoires, la vitesse de réaction du mélange hydrogène‐oxygène dans des rapports variés. La vitesse est maxima pour les mélanges dans le rapport 4:1 à 3:1.

En fonction du rendement quantique du mélange hydrogène‐oxygène γ, on obtien ainsi pour l'hydrogénation de l'éthylène un rendement quantique de 1, 2 γ, pour l'hydrogénation du propylène 0, 11 γ et pour la polymérisation de l'acétylène 1, 7 γ.
Préparation de la méthoxyacétylacétone
Authors: Renard M. , Maquinay A.
Published: September 2010

On prépare la méthoxyacétylacétone en condensant, en solution éthérée ou benzénique, le méthoxyacétate d'éthyle avec l'acétone, en présence de sodium.

On obtient ainsi le dérivé sodé de la méthoxyacétylacétone. Celle‐ci est mise en liberié par l'acide acétique dilué et purifiée par précipitation à l'état de dérivé cuivrique. Ce dernier, traité par l'acide sulfurique dilué, régénère la méthoxyacétylacétone qu'on extrait à l'éther. Après élimination de l'éther, on distille le résidu sous pression réduite (température d'ébullition: 68‐69° sous 14 mm).

La méthoxyacétylacétone présente, en général, les me'mes propriétés chimiques que l'acétylacétone. Toutefois, la présence dans la molécule du groupement CH3O parai't exalter fortement l'énolisation, au point qu'on peut se demander s'il ne se produit pas, dans cette molécule, une énolisation double.
La spiro‐di‐triméthylènimine 3.3′ ou diaminaspiroheptane. I
Authors: Govaert F. , Beyaert M.
Published: September 2010

In this communication the synthesis of several derivatives of the as yet unknown bistrimethyleneimine‐3.3′‐spiran is described.

In order to obtain this spirodiamine we first synthetised the 2.‐2. bis‐bromomethyl‐1.3. bisaminopropane‐hydrobromide. After the action on this product of exactly two moles of silver hydroxide we could not isolate the corresponding free base, but a spontaneous intramolecular transformation occurred and the hydrobromide of the bistrimethyleneimine‐3.3′‐spiran was obtained:.

magnified image

From the compound obtained we went out to prepare the corresponding hydrochloride, picrate and o. nitrobenzoylderivative. The analyses made upon these were all in accordance with the proposed formula.

Several attempts were made to isolate the free pure spirodiamine but without any success. Although by our experiments it was proved that the free spirodiamine can exist at low temperature in aqueous solution, the evaporation of this latter, even in vacuo, yields an amorphous polymer, insoluble in water or in an organic liquid whatsoever, and even resisting the attack of strongly concentrated mineral acids or bases.
Sur Une Dopplerite Contribution À l'Étude des Acides Humiques et Du Processus de Formation de la Houille
Authors: Kreulen D. J. W.
Published: September 2010

Une couche de dopplerite d'une épaisseur de plusieurs décimètres a été découverte dans une tourbière néerlandaise. Cette découverte a permis une étude détaillée de la composition et des propriétés de cette matière tourbeuse.

La dopplerite est un gel pur d'acide humique, lequel a adsorbé un peu de sels inorganiques. l'ancienne conception, selon laquelle la dopplerite serait un sel calcique d'acide humique, n'est pas soutenable.

L'auteur a préparé des solutions colloïdales de dopplerite dans de la pyridine, de la quinoléine et de l'ortho‐nitroanisol. Les acides humiques dispersés n'accusent pas la même composition que ceux non dissous.

On peut déterminer au moyen de la méthode à l'acétate de chaux deux groupes COOH par molécule d'acide humique dans la dopplerite ainsi que dans la tourbe et le lignite. Si l'on extrait les acides humiques au moyen de soude caustique et les régénère avec l'acide, on détermine cependant dans les acides humiques ainsi obtenus quatre groupes COOH par molécule.

Pendant la distillation pyrogénée de la dopplerite il se forme un goudron, dont la composition a été déterminée.

Pendant la destruction thermique de la dopplerite, on obtient du bitume à côté de matières humiques. La composition chimique moyenne de ce bitume a été déterminée par hydrogénation. En outre, ce bitume a été divisé en plusieurs fractions. Les propriétés de ces fractions sont discutées.

Le bitume obtenu à partir de la dopplerite représente un système identique aux extraits obtenus à partir de houille. l'auteur a obtenu même des fractions possédant des propriétés cokéfiantes.

On conclut de ces essais que, pendant la transformation de la tourbe en houille, il se forme à partir des acides humiques du bitume en même temps que des matières humiques.

l'ancienne conception, selon laquelle le bitume de la houille provient de substances spéciales, de cires et de résines par exemple, est done à rejeter.
La recherche des acides α monoaminés monocarboxylés dans les hydrolysats protéiques par la spectrographie Raman III. La recherche du glycocolle dans l'ovalbumine
Authors: Renard M. , Michel G.
Published: September 2010

La méthode qui a été exposée précédemment par l'un de nous (1), a été appliquée à la recherche du glycocolle dans l'ovalbumine. Les résultats obtenus confirment la présence de cet acide aminé dans la protéine en question.
Sur la structure cristallographique du coronène
Authors: Ruston W. R. , Rüdorff W.
Published: September 2010

La structure cristallographique du coronène, C24H12, a été étudiée à l'aide des rayons X et l'orientation des molécules dans la maille élémentaire a été déterminée par la méthode trial and error. Le coronène cristallise dans le système monoclinique et son groupe spatial est C52h‐P21/c. Des lignes d'intensité moindre sur le diagramme par rotation autour de l'axe c indiquent l'existence d'une deuxième variété à axc c doublé.

Cette étude, terminée en 1945, n'avait pas encore pu étre publiée en raison des circonstances, quand parut le travail de J. M. Robertson et J. G. White (1), effectué indépendamment du nôtre.

Les résultats des deux travaux sont pratiquement identiques. Cependant, l'étude par la méthode de Fourier donne plus de détails sur la structure que la méthode trial and error que nous avons suivie.

Nous jugeons cependant utile de publier nos résultats parce que d'une part, ils confirment les premiers et que d'autre part, nous avons fait certaines observations que les auteurs précités n'ont pas aperçues. C'est pourquoi nous éliminons la description complète de notre travail et donnons seulement un rapport abrégé.
La polymérisation du méthacrylate de méthyle en présence de solvants chlorés et de catalyseurs
Authors: Smets G. , Reiske P.
Published: September 2010

l'influence de certains solvants sur le degré de polymérisation du polyméthacrylate de méthyle a été étudiée. En présence de catalyseur, le degré de polymérisation est inversement proportionnel à la racine carrée de la concentration en catalyseur; ce facteur de proportionnalité reste sensiblement constant pour des rapports molaires, solvant‐monomère, variables; sa valeur augmente sensiblement en solution diluée (10 %). L'influence de la température et de la concentration en catalyseur sur le degré de polymérisation moyen sont fonction de l'efficacité de chocs entre solvant et chaines en croissance, et par conséquent, fonction de la nature du solvant.

l'homogénéité des polymères est favorisée par l'utilisation de solvants efficaces, tels les solvants chlorés; les polymères ainsi obtenus contiennent du chlore dans leur molécule; leur degré de polymérisation est toutefois abaissé.
Réalisation et Mise au Point d'un Appareil de Mesure de Double Réfraction De Flux
Authors: Fredericq E. , Desreux V.
Published: September 2010

The detailed description of an apparatus for flow birefringence measurements is given.

The optical adjustment is described and the different causes of errors are discussed.
Mesures, par Double Réfraction de Flux, de la Taille de Particules d'Ovalbumine Dénaturée
Authors: Fredericq Eugène
Published: September 2010

The molecular dimensions of egg albumin denatured in several ways are determined by the method of flow birefringence. For particles of egg albumin denatured at 100° in different concentrations of acid, the long axe varies from 900 to 1.800 Å. The influence of pH is followed by the same method. The size of egg albumin dodecylbenzenesulfonate complexes has been measured at different proportions of the components. A structure is proposed for interpreting this measurements.

The problem of egg albumin sulfhydryl groups in connection with detergent action is discussed. It is shown that there is no correlation between unfolding of polypeptidic chains and SH groups activation under influence of detergents.
Le Mécanisme par Radicaux Libres de la Chimiluminescence en Solutions
Authors: Bernanose A. , Bremer Th. , Goldfinger P.
Published: September 2010

Les réducteurs, qui réagissent avec l'eau oxygénée, activent la luminescence causée par celle‐cis dans des solutions alcalines de phtalhydrazide et de 3‐aminophtalhydrazide. Ces hydrazides sont, d'autre part, des inhibiteurs de la décomposition de l'eau oxygénée.

Une interprétation de ces résultats, ainsi que de ceux d'autres auteurs, est proposée en accord avec la théorie de Haber et Willstaetter, les radicaux OH* et O2H* se comportant comme accepteurs d'électrons vis‐à‐vis de l'ion de l'hydrazide et transformant celui‐ci en un radical semi‐quinone; l'oxydation ou la dismutation subséquente de ce radical serait l'origine de la chimiluminescence.

La plupart des réctions actuellement connues des hydrazides phtaliques peuvent être interprétées suivant ce schéma. Mais aucune explication n'a pu être donnée jusqu à présent des effets de neutralisation, de dilution et des effets de sels décrits par Svesnikov ainsi que par Druckrey et Richter.
Dosage de la Vitamine D2 Dans les Produits d'Irradiation de l'Ergostérol
Authors: Pirlot G. , Rouir E.‐V.
Published: September 2010

The determination of vitamin D2 in the presence of different irradiation products of ergosterol is rather difficult by simple ultra‐violet absorption spectroscopy, due to the superposition of the obsorption bands of these substances.

It is thus necessary to resort to chemical transformations in order to get products wich absorb in different wavelenght ranges for the several substances in presence. The procedure we have worked out; based on a reaction given by Sobel and coworkers, is suited to the determination of vitamin D2 prepared from ergosterol.
Quelques Dérivés de l'Oxodiazol
Authors: Merckx R.
Published: September 2010

The 1‐2‐4‐Oxodiazol derivatives substituted in the 5‐position by the ‐CH2‐CN group have not yet been dealt with in chemical literature. The author has examined the possibility of preparing these compounds from amidoximes.

The various methods applied are discussed.

The best results have been obtained in the following way: the product obtained by the condensation of the amidoximes with cyanacetylchloride is heated in the presence of acetic acid.
Possibilités de Dosage Spectrophotométrique Direct de la Vitamine D2 en Solution Pure et en Présence de Sels Calciques
Authors: Lasareff V. , Rouir E. V.
Published: September 2010

The sensitivity of a direct spectrophotometric determination of vitamin D2 (calciferol), based on its ultra‐violet absorption, proved to be 1 microgram/ml., or better. Compared with the current colorimetric techniques, the ultra‐violet method is capable of a much higher accuracy.‐The ultra‐violet absorption spectrum of calciferol remains unchanged in the presence of calcium phosphate or gluconate. The latter compounds show only a slight continuous absorption in the same spectral range. Consequently, the ultra‐violet determination of calciferol can be performed without previous elimination of calcium salts.
Sur quelques dérivés acylméthyléniques de bases hétérocycliques
Authors: van Dormael A. , Ghys Th.
Published: September 2010

Après avoir donné un aperçu des diverses méthodes de préparation des dérivés acylméthyléniques de bases hétérocycliques, les auteurs décrivent une nouvelle synthèse de ces cétones par l'action d'esters acylpyruviques sur les sels cycloammoniques porteurs d'un groupement thio‐alcoyle réactionnel.

L'action des acides acylpyruviques libres sur ces mêmes sels a également été étudiée.
Mérocyanines Quaternées
Authors: van Dormael A.
Published: September 2010

L'auteur décrit la transformation de rhodanino‐mérocyanines quaternées en dérivés méthyléniques disubstitués correspondants par l'action d'esters ou d'anilides acyl‐acétiques ou d'esters anilides‐maloniques, suivie d'hydrolyse acide en mérocyanines quaternées portant un groupement méthyle dans le noyau de la rhodanine.

La base méthylénique non substituée qui dérive de ce dernier colorant est également décrite.
Dérivés acylméthyléniques. II. Mérocyanines à substitution acylméthylénique
Authors: van Dormael A. , Ghys Th.
Published: September 2010

Les auteurs décrivent des rhodanino‐mérocyanines à substitution acylméthylénique dans le noyau de la rhodanine. Ces nouveaux dérivés s'obtiennent par l'action des chlorures acides sur les mérocyanines quaternées portant un groupement méthyle dans le noyau de la rhodanine, ou bien par hydrolyse des dérivés diacylméthyléniques, obtenus par l'action de β‐dicétones sur les mérocyanines quaternées, ou bien directement aux dépens de ces dernières par l'action d'acides acylacétiques ou d'esters acylpyruviques.
Polymérisation du méthacrylate de méthyle en solution et en bloc
Authors: Smets G. , Masquelier C. , van Tornout F.
Published: September 2010

La polymérisation du méthacrylate de méthyle en solution est fortement influencée par le pouvoir dissolvant du milieu de réaction; à des concentrations de 32,9 p. 100 de monomère, la réaction suit un ordre apparent de premier ordre, par rapport au monomère, si le polymère est soluble dans le solvant. Dans le cas contraire, la réaction subit une accélération notable, concomitamment à une augmentation considérable du poids moléculaire; ces deux effets sont attribués à une diminution de la vitesse de rupture au sein du milieu très visqueux.

Par des essais de polymérisation en bloc du méthacrylate de méthyle pur et en présence de nitrobenzène, comme inhibiteur, cette explication est confirmée. La polydispersité des produits ainsi obtenus a été établie; il se manifeste deux maxima nets dans la courbe de répartition en poids des polymères fractionnés.
Les nitriles et les amides bromcrotoniques II
Authors: Leclercq L. , Bruylants A.
Published: September 2010

Les auteurs ont isolé deux nouveaux couples d'isomères géométriques: les nitriles (Eb. 10 mm 87‐88° C; 74‐75° C) et les amides (Fus. 114‐115° C; 90‐90,5° C) bromcrotoniques γ.

Accessoirement, ils ont préparé les dérivés saturés correspondants, le nitrile (Eb. 10 mm 80‐81° C) et l'amide (Fus. 84‐85° C) brombutyriques γ.

Les nitriles ont été soumis à une étude réfractométrique et les amides à l'analyse thermique.
Sur la substance responsable de la fluorescence de l'adrénaline
Authors: Fischer P.
Published: September 2010

La fluorescence de l'adrénaline et de l'adrénochrome en milieu alcalin est due à la formation du corps (III) isolé par Harley‐Mason. II paraît fort improbable que ce corps résulte de l'évolution d'un ou de plusieurs dérivés réduits de l'adrénochrome.