bluuebunny/crossref_metadata_2025 huggingface dataset:
Path Planning for Two-Link Navigation in an Unknown Environment Using Webcam
Authors: Shojaeipour Shahed , Sedigh Ali Khaki , Shojaeipour Ali , Weng Edmund Ng Giap , Hadavi Nooshin
Published: September 2010

In this article, we used image processing by a webcam connected on top of the arm robot. The robot navigation is in an unknown environment. Then start point and target point were determined for the robot, so the robot needs to have a program for path planning using Voronoi diagrams to find the path. After the possible path for moving the robot was found, the route information obtained was sent to the arm robot. The arm robot moves in the workspace and any time new information was processed via the webcam. The program was written using MATLAB software which at controls the robot’s movement the unknown environment.
Optimum Design of Industrial Robot Grippers
Authors: Simionescu Ion , Ion Ion , Vladareanu Luige
Published: September 2010

Of all feasible designs, some are “better” than others. If this is assumed as true, then there must be some quality that the better designs have more of than the lees desirable ones do. This quality must be expressed as a computable function of the design variables, and it can consider optimizing to obtain a “best” design. The function with respect to which the design is optimized is called the objective function. In some design situations, there may appear to be two or more quantities which should be objective functions. The goal of the kinematics synthesis of the linkages is to establish the kinematics dimensions of the component elements provided that some conditions are imposed regarding movements of some points or elements. As a rule, only conditions about the positions of the points or elements are imposed. In the other words, only the transmission functions of the positions are used to write the synthesis equations. The solving of the kinematics synthesis problems is reduced to the solving of some nonlinear equation systems. As a result, the problems of the kinematics synthesis of linkages do not have the unique solutions. Only in some very simples particular cases the system of synthesis equations is linear and problem has a single solution. In the optimum synthesis of the gripper mechanisms, the objective function may express the positioning precision of the work pieces, the magnitude of the driving force, the domain of the stable fastening of the work pieces etc. In the work, some considerations about the optimum synthesis of the two fingered self centering grippers are shown.
Modular Robotic System for Moving Inside of Pipelines - Part 2
Authors: Alutei Adrian , Tatar Mihai Olimpiu , Cirebea Claudiu
Published: September 2010

This paper deals with aspects related to modeling, simulation and development of the drive and control systems for a modular robotic system for inspection and exploration. In the first part of the paper the proposed robotic system model is presented. In the second part of the paper the robotic system simulation in MATLAB / Simulink is presented, obtaining the necessary data to dimension the actuators. The command and control developed systems are presented in the end of the paper.
About an Experimental Approach Used to Determine the Kinematics of the Human Finger Movement
Authors: Berceanu Cosmin , Tarniţă Daniela , Filip Dumitru
Published: September 2010

Nowadays the robotic or prosthetic artificial hands strive to achieve a high degree of anthropomorphism, a concept which expresses the capability of a robotic end-effector to mimic the human hand, partly or totally, as far as shape, size, consistency, and general aspect (including color, temperature, and so on). This paper proposes a new experimental approach regarding the kinematics of the human finger movement. By using video capture of a particular finger movement and dedicated video processing software we have determined the laws of variation for the main joints in the human finger. Therefore, the experimental method presented in detail in this paper is useful to corroborate the kinematic parameters (displacements, velocities and accelerations, linear or rotary) of an artificial robotic finger movement with those of the human finger movement.
Exteroceptive Sensor System of a New Developed Artificial Hand
Authors: Berceanu Cosmin , Tarniţă Daniela , Filip Dumitru
Published: September 2010

In this paper we present a novel approach regarding the exteroceptive sensor system of a new developed artificial hand. Force and proximity (distance) sensors are the main components of the exteroceptive sensor system of the new artificial hand. Modern control algorithms are conceived in relation to the signals received from these sensors.
Remote Controlled Video Inspection Manipulator of Sewage Networks Pipes
Authors: Bruja Adrian , Dima Marian , Frâncu Cătălin
Published: September 2010

The paper presents the research results carried out by the team of authors over the past 10 years in the field of video inspection of sewer pipes manipulators, designed based on the connecting cable technology between inspection module and the surface control unit and on wireless technology.
Parameters of Reserpine Analogs That Induce MSH2/MSH6‐Dependent Cytotoxic Response
Authors: Vasilyeva Aksana , Clodfelter Jill E. , Gorczynski Michael J. , Gerardi Anthony R. , King S. Bruce , Salsbury Freddie , Scarpinato Karin D.
Published: September 2010

Mismatch repair proteins modulate the cytotoxicity of several chemotherapeutic agents. We have recently proposed a “death conformation” of the MutS homologous proteins that is distinguishable from their “repair conformation.” This conformation can be induced by a small molecule, reserpine, leading to DNA‐independent cell death. We investigated the parameters for a small reserpine‐like molecule that are required to interact with MSH2/MSH6 to induce MSH2/MSH6‐dependent cytotoxic response. A multidisciplinary approach involving structural modeling, chemical synthesis, and cell biology analyzed reserpine analogs and modifications. We demonstrate that the parameters controlling the induction of MSH2/MSH6‐dependent cytotoxicity for reserpine‐analogous molecules reside in the specific requirements for methoxy groups, the size of the molecule, and the orientation of molecules within the protein‐binding pocket. Reserpine analog rescinnamine showed improved MSH2‐dependent cytotoxicity. These results have important implications for the identification of compounds that require functional MMR proteins to exhibit their full cytotoxicity, which will avoid resistance in MMR‐deficient cells.
Herpes Zoster Infections in SLE in a University Hospital in Saudi Arabia: Risk Factors and Outcomes
Authors: Sayeeda Afsar , Al Arfaj Hussain , Khalil Najma , Al Arfaj A. S.
Published: September 2010

Patients with SLE carry an increased risk of infection that account for 11–23% of all hospitalized patients and 50% of all SLE patients develop major infections during the course of their disease. Globally Herpes Zoster has been reported as the most frequent viral infection in SLE patients. We determined the clinical spectrum, disease sequelae and the risk factors associated with the development of Herpes Zoster in patients with SLE and their outcomes. Retrospective case control study of Herpes Zoster infections was done in SLE patients between 1982 and 2006. Cases were matched 1:2 to controls for age, race, sex and duration of follow up. Clinical features of the cases from the time of lupus diagnosis to the time of Zoster were compared to their respective controls over similar time periods. Thirty two SLE cases were compared to sixty four controls. Cases were more likely to have received cyclophosphamide () and intravenous methylprednisolone pulse therapy (), MMF (), had leucopenia () and hemolytic anemia (). More cases than controls had lupus nephritis, cerebritis, thrombocytopenia but the differences did not reach statistical significance. The mean oral prednisolone dose and proportion of patients receiving immunosuppressives including pulse methylprednisolone therapy, IV Cyclophosphamide and mycophenolate was significantly higher in patients with active SLE compared to patients with SLE in remission at the time of Herpes Zoster (). Disseminated Zoster developed in patients with active SLE (7/9) compared to patients with SLE in remission (0/23). None of the patients had postherpetic neuralgia or bacterial super infection. Immunosuppressive medications were discontinued at the time of diagnosis of Zoster in 19 of 32 patients and all patients received antiviral medications.There were no permanent neurologic deficits or deaths. We conclude that Herpes Zoster infections occur at increased frequency among patients with SLE and carry significant morbidity. Immunosuppressive therapy and severe manifestations of lupus may be risk factors for the development of Herpes Zoster although not necessarily at the time of disease flare or immunosuppressive therapy. Our study suggests that although Herpes Zoster occurs frequently in patients with SLE, it has a relatively benign course.
Acute medicine units: the current state of affairs in the North-West of England
Authors: Jayawarna C , Atkinson D , Ahmed SV , Leong K
Published: September 2010

Studies suggest that acute medicine units (AMU) reduce inpatient mortality, length of stay and re-admissions and improve four-hour performance targets. Over the past decade or so, after evaluating the system in place, the Royal College of Physicians of London (RCPL) has made key recommendations for an efficient and effective AMU. This audit reviews the current infrastructure of regional AMUs against those RCPL recommendations in respect of facilities, service provision and staffing. A total of 22 regional hospitals in the North-West of England were invited to participate in this audit; 19 responded. Two units did not have designated AMU facilities. Not a single hospital met all basic infrastructure recommendations. Only four had the recommended bed capacity, nine had recommended cardiacmonitoring facilities and incorporated ‘short-stay units’, 13 used early warning systems for patient triage and six had the recommended number of consultants assigned to AMUs with a designated medical team. Notably, there were suboptimal numbers of allied healthcare professionals in most units. In summary, the majority of the AMUs in the North-West of England lack sufficient resources to meet even the most basic RCPL recommendations. A national in-depth audit is needed to determine fully the current state and thus guide future health planning.
Gastrointestinal tuberculosis: a diagnosis not to miss
Authors: Manuel A , Lim Z , Wiggins J
Published: September 2010

Gastrointestinal tuberculosis is not rare but may present to the clinician in a variety of ways, leading to confusion with several other diseases. It is crucial to send tissue samples for culture.
Unilateral balsalazide-induced eosinophilic pneumonia in an ulcerative colitis patient
Authors: McGrane J , Paravasthu M , Candlish W , Gravil J
Published: September 2010

We report a case of unilateral eosinophilic pneumonia secondary to balsalazide monotherapy for ulcerative colitis. After commencing balsalazide, the patient presented with a history of cough, progressive dyspnoea and lethargy. Blood counts revealed peripheral eosinophilia. Her chest radiograph showed leftsided infiltration, and high-resolution computerised tomography demonstrated widespread nodular shadowing and ground glass opacifiction in the left lung. The right lung was normal. Transbronchial lung biopsy confirmed eosinophilic pneumonia. There was rapid clinical and radiological improvement after withdrawing balsalazide. Drug-induced eosinophilic pneumonia has been described with mesalazine and sulfasalazine, but no case reports of balsalazide-induced eosinophilic pneumonitis have been found.
What is the optimum duration of anticoagulation for the management of patients with idiopathic deep venous thrombosis and pulmonary embolism?
Authors: Hyers TM , Shetty HG , Campbell IA
Published: September 2010

The optimum duration of anticoagulation following idiopathic deep venous thrombosis and pulmonary embolism is controversial. The JRCPE is delighted to publish a debate written by three international experts. Dr Shetty and Dr Campbell recommend that three months’ anticoagulation is sufficient, while Professor Hyers recommends anticoagulation for longer than three months.
Nervous system Lyme disease
Authors: Halperin JJ
Published: September 2010

Lyme disease, the multi-system infection caused by the tick-borne spirochaete Borrelia burgdorferi, can involve the nervous system, most commonly causing, alone or in combination, lymphocytic meningitis or abnormalities of cranial or peripheral nerves, the latter most typically presenting as a painful radicular syndrome. Diagnosis is based on appropriately used, standard serological tests; in instances where the central nervous system is involved, cerebrospinal fluid assessment for organism-specific antibodies can be useful. Treatment with any of several standard regimens of oral or parenteral antimicrobials is highly effective. Prolonged treatment beyond four weeks is rarely if ever warranted, and carries significant risk.
James Ross (1837–1892) and his forgotten neurology textbook of 1881
Authors: Eadie MJ
Published: September 2010

James Ross (1837–1892) was an Aberdeen medical graduate who, after 13 years in rural general practice, mainly in Lancashire, became a pathologist and then physician to the Manchester Royal Infirmary and professor of medicine at Owens College, Manchester. In mid-career he developed a major interest in clinical neurology and became, apart from Byrom Bramwell in Edinburgh, the only contemporary British physician outside London who had widely recognised neurological expertise. Ross made several notable original contributions to neurological knowledge, particularly in relation to aphasia and peripheral neuritis. He wrote the entire contents of the two editions of the massive two-volume A Treatise on the Diseases of the Nervous System (1881 and 1883), which was very favourably reviewed and commercially successful but which, like its author who died at the height of his powers, was soon forgotten once William Gowers’ A Manual of Diseases of the Nervous System became available in the late 1880s.
Temperature variability and trends in the UT-LS over a subtropical site: Reunion (20.8° S, 55.5° E)
Authors: Bègue N. , Bencherif H. , Sivakumar V. , Kirgis G. , Mze N. , Leclair de Bellevue J.
Published: September 2010

Abstract. This paper mainly focuses on the trends and variability of the UT-LS temperature using radiosonde observations carried out over 16 years (January 1993 to December 2008) from a southern subtropical site, Reunion (20.8° S, 55.5° E), using a linear-regression fitting model. Two kinds of tropopause definitions, namely, cold point tropopause (CPT) and lapse rate tropopause (LRT) are used. In order to characterize and quantify the relationship between regional oceanic forcing and temperature at UT-LS, we took into account the Indian Ocean Dipole (IOD) for the estimation of temperature trends. Results show that the main component is the Annual Cycle (AC), particularly at tropopause (CPT, LRT) and in the lower stratosphere (LS) where more than 26.0±2.4% of temperature variability can be explained by AC. The influence of IOD on the variability of the temperature is at highest ratio at CPT and LS, with respectively 12.3±7.3% and 13.1±5.9%. The correlations between IOD and temperature anomalies at UT-LS are barely significant, which are found to be in close agreement with the results obtained by Rosenlof et al. (2008) over the western tropical Pacific Ocean. The temperature trend in the LS reveals a cooling of about −0.90±0.40 K per decade. The cooling trend at LS is found to be in close agreement with the others studies. Trend estimates in the LS suggest that IOD forcing contributes to increasing cooling by about 0.16±0.05 K per decade. Past works have shown that the additional carbon dioxide increase has a minor effect in the LS, and suggested that other effects than ozone and carbon dioxide changes have to be considered, in order to explain the observed temperature changes in the LS. From this study, we can suggest that the SST changes can be considered also, in addition to effects due to ozone and carbon dioxide changes, in order to explain the observed temperature changes in the LS. As a consequence, our results support the assumption that the Indian Ocean may have a slight impact on temperature variability and on temperature change in the LS over Reunion.
Origin and radiative forcing of black carbon transported to the Himalayas and Tibetan Plateau
Authors: Kopacz M. , Mauzerall D. L. , Wang J. , Leibensperger E. M. , Henze D. K. , Singh K.
Published: September 2010

Abstract. The remote and high elevation regions of central Asia are influenced by black carbon (BC) emissions from a variety of locations. BC deposition contributes to melting of glaciers and questions exist, of both scientific and policy interest, as to the origin of the BC reaching the glaciers. We use the adjoint of the GEOS-Chem model to identify the location from which BC arriving at a variety of locations in the Himalayas and Tibetan Plateau originates. We then calculate its direct and snow-albedo radiative forcing. We analyze the seasonal variation in the origin of BC using an adjoint sensitivity analysis, which provides a detailed map of the location of emissions that directly contribute to black carbon concentrations at receptor locations. We find that emissions from northern India and central China contribute the majority of BC to the Himalayas, although the precise location varies with season. The Tibetan Plateau receives most BC from western and central China, as well as from India, Nepal, the Middle East, Pakistan and other countries. The magnitude of contribution from each region varies with season and receptor location. We find that sources as varied as African biomass burning and Middle Eastern fossil fuel combustion can significantly contribute to the BC reaching the Himalayas and Tibetan Plateau. We compute radiative forcing in the snow-covered regions and estimate the forcing due to the BC induced snow-albedo effect at about 5–15 W m−2 within the region, an order of magnitude larger than radiative forcing due to the direct effect, and with significant seasonal variation in the northern Tibetan Plateau. Radiative forcing from reduced snow albedo accelerates glacier melting. Our analysis can help inform mitigation efforts to slow the rate of glacial melt by identifying regions that make the largest contributions to BC deposition in the Himalayas and Tibetan Plateau.
Biogeochemical controls and isotopic signatures of nitrous oxide production by a marine ammonia-oxidizing bacterium
Authors: Frame C. H. , Casciotti K. L.
Published: September 2010

Abstract. Nitrous oxide (N2O) is a trace gas that contributes to the greenhouse effect and stratospheric ozone depletion. The N2O yield from nitrification (moles N2O-N produced per mole ammonium-N consumed) has been used to estimate marine N2O production rates from measured nitrification rates and global estimates of oceanic export production. However, the N2O yield from nitrification is not constant. Previous culture-based measurements indicate that N2O yield increases as oxygen (O2) concentration decreases and as nitrite (NO2−) concentration increases. Here, we have measured yields of N2O from cultures of the marine β-proteobacterium Nitrosomonas marina C-113a as they grew on low-ammonium (50 μM) media. These yields, which were typically between 4 × 10−4 and 7 × 10−4 for cultures with cell densities between 2 × 102 and 2.1 × 104 cells ml−1, were lower than previous reports for ammonia-oxidizing bacteria. The observed impact of O2 concentration on yield was also smaller than previously reported under all conditions except at high starting cell densities (1.5 × 106 cells ml−1), where 160-fold higher yields were observed at 0.5% O2 (5.1 μM dissolved O2) compared with 20% O2 (203 μM dissolved O2). At lower cell densities (2 × 102 and 2.1 × 104 cells ml−1), cultures grown under 0.5% O2 had yields that were only 1.25- to 1.73-fold higher than cultures grown under 20% O2. Thus, previously reported many-fold increases in N2O yield with dropping O2 could be reproduced only at cell densities that far exceeded those of ammonia oxidizers in the ocean. The presence of excess NO2− (up to 1 mM) in the growth medium also increased N2O yields by an average of 70% to 87% depending on O2 concentration. We made stable isotopic measurements on N2O from these cultures to identify the biochemical mechanisms behind variations in N2O yield. Based on measurements of δ15Nbulk, site preference (SP = δ15Nα−δ15Nβ), and δ18O of N2O (δ18O-N2O), we estimate that nitrifier-denitrification produced between 11% and 26% of N2O from cultures grown under 20% O2 and 43% to 87% under 0.5% O2. We also demonstrate that a positive correlation between SP and δ18O-N2O is expected when nitrifying bacteria produce N2O. A positive relationship between SP and δ18O-N2O has been observed in environmental N2O datasets, but until now, explanations for the observation invoked only denitrification. Such interpretations may overestimate the role of heterotrophic denitrification and underestimate the role of ammonia oxidation in environmental N2O production.
Integrating field sampling, spatial statistics and remote sensing to map wetland vegetation in the Pantanal, Brazil
Authors: Arieira J. , Karssenberg D. , de Jong S. M. , Addink E. A. , Couto E. G. , Nunes da Cunha C. , Skøien J. O.
Published: September 2010

Abstract. To improve the protection of wetlands, it is imperative to have a thorough understanding of their structuring elements and of the identification of efficient methods to describe and monitor them. This article uses sophisticated statistical classification, interpolation and error propagation techniques, in order to describe vegetation spatial patterns, map plant community distribution and evaluate the capability of statistical approaches to produce high-quality vegetation maps. The approach results in seven vegetation communities with a known floral composition that can be mapped over large areas using remotely sensed data. The relations between remotely sensing data and vegetation patterns, captured in four factorial axes, were formalized mathematically in multiple linear regression models and used in a universal kriging procedure to reduce the uncertainty in mapped communities. Universal kriging has shown to be a valuable interpolation technique because parts of vegetation variability not explained by the images could be modeled as spatially correlated residuals, increasing prediction accuracy. Differences in spatial dependence of the vegetation gradients evidenced the multi-scale nature of vegetation communities. Cross validation procedures and Monte Carlo simulations were used to quantify the uncertainty in the resulting map. Cross-validation showed that accuracy in classification varies according with the community type, as a result of sampling density and configuration. A map of uncertainty resulted from Monte Carlo simulations displayed the spatial variation in classification accuracy, showing that the quality of classification varies spatially, even though the proportion and arrangement of communities observed in the original map is preserved to a great extent. These results suggested that mapping improvement could be achieved by increasing the number of field observations of those communities with a scattered and small patch size distribution; or by including new digital images as explanatory variables in the model. By comparing the resulting plant community map with a flood duration map, we verified that flooding duration is an important driver of vegetation zonation. We discuss our study in the context of developing a mapping approach that is able to integrate field point data and high-resolution remote sensing images, providing new basis to map wetland vegetation and allowing its future application in habitat management, conservation assessment and long-term ecological monitoring in wetland landscapes.
Linkage between an advanced air quality model and a mechanistic watershed model
Authors: Vijayaraghavan K. , Herr J. , Chen S.-Y. , Knipping E.
Published: September 2010

Abstract. An offline linkage between two advanced multi-pollutant air quality and watershed models is presented. The models linked are (1) the Advanced Modeling System for Transport, Emissions, Reactions and Deposition of Atmospheric Matter (AMSTERDAM) (a three-dimensional Eulerian plume-in-grid model derived from the Community Multiscale Air Quality (CMAQ) model) and (2) the Watershed Analysis Risk Management Framework (WARMF). The pollutants linked include gaseous and particulate nitrogen, sulfur and mercury compounds. The linkage may also be used to obtain meteorological fields such as precipitation and air temperature required by WARMF from the outputs of the meteorology chemistry interface processor (MCIP) that processes meteorology simulated by the fifth generation Mesoscale Model (MM5) or the Weather Research and Forecast (WRF) model for input to AMSTERDAM. The linkage is tested in the Catawba River basin of North and South Carolina for ammonium, nitrate and sulfate. Modeled air quality and meteorological fields transferred by the linkage can supplement the conventional measurements used to drive WARMF and may be used to help predict the impact of changes in atmospheric emissions on water quality.
Water balance modeling of Upper Blue Nile catchments using a top-down approach
Authors: Tekleab S. , Uhlenbrook S. , Mohamed Y. , Savenije H. H. G. , Ayalew S. , Temesgen M. , Wenninger J.
Published: September 2010

Abstract. The hydrological behavior and functioning of twenty catchments in the Upper Blue Nile basin have been analyzed using a top-down modeling approach that is based on Budyko's hypotheses. The objective is to obtain better understanding of catchment response for prediction in ungauged catchments. The water balance analysis using Budyko-type curve at annual scale reveals that the aridity index does not exert a first order control in most of the catchments. This implies the need to increase model complexity to a monthly time scale to include the effects of seasonal soil moisture dynamics. The dynamic water balance model used in this study predicts the direct runoff and other processes based on limit concept. The uncertainty of model parameters has been assessed using the GLUE (Generalized Likelihood Uncertainty Estimation). The results show that the majority of the parameters are reasonably well identifiable. Moreover, a multi-objective model calibration strategy has been employed within the GLUE framework to emphasize the different aspects of the hydrographs on low and high flows. The model has been calibrated and validated against observed streamflow time series and it shows good performance for the twenty catchments of the upper Blue Nile. During the calibration period (1995–2000) the Nash and Sutcliffe coefficient of efficiency for monthly flow prediction varied between 0.52 to 0.93 during high flows, while it varied between 0.32 to 0.90 during low flows (logarithms of flow series). The model is parsimonious and it is suggested that the resulting parameters can be used to predict monthly stream flows in the ungauged catchments of the Upper Blue Nile basin, which accounts about 60% of total Nile basin flow.
Investigation of poly(vinyl chloride)/polystyrene mixture miscibility: Comparison of viscometry criteria with Fourier transform infrared spectroscopy and refractive index measurements
Authors: Aquino Kátia Aparecida da S. , da Silva Flávio Ferreira , Araújo Elmo S.
Published: September 2010

The refractive index (RI) and Fourier transform infrared (FTIR) spectrum of a poly(vinyl chloride) (PVC)/polystyrene (PS) mixture were measured. The variation of RI with the mixture composition was found to be nonlinear, which indicated the immiscibility of the PVC/PS mixture. This result agrees with results obtained by the FTIR technique, which indicated negligible intermolecular interactions between the PVC/PS components, and the miscibility of the polymer mixture was limited for the compositions studied. The results obtained by RI and FTIR were compared with the results obtained by the viscosity method with criteria based on interaction parameters proposed by Krigbaum and Wall, Chee, Zhu, and Garcia et al. and the thermodynamic parameter proposed by Jiang and Han. A criterion based on a simple cluster theory proposed by Pan et al. was also applied to the PVC/PS mixture solutions to study the polymer–polymer interactions. The conclusions about PVC/PS immiscibility made by Pan et al. and Jiang and Han agreed with our conclusions obtained by FTIR and RI measurements. On the other hand, the results obtained by Chee, Zhu, and Krigbaum and Wall showed partial miscibility of the PVC/PS mixture, whereas the polymer mixture was miscible according to the Garcia et al. criterion. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
The influence of matrix viscosity on properties of polypropylene/polyaniline composite fibers—Rheological, electrical, and mechanical characteristics
Authors: Soroudi Azadeh , Skrifvars Mikael
Published: September 2010

Electrically conductive composites containing polypropylene (PP) and polyaniline (PANI) were prepared using PP with three different melt flow rates (MFRs) and a commercial PANI‐complex in proportions of 80% by weight and 20%, respectively. Composite blends were melt‐spun to fibers under different solid‐state draw ratios. Rheological studies of dynamic viscosity, as well as the storage modulus and loss modulus showed that the prepared PANI‐complex/PP blends exhibit different dynamic rheological behavior, depending on the PP used. This confirms the blends' morphological differences. PP matrix viscosity was found to play an important role in the electrical properties of the prepared fibers. Fibers prepared using the matrix with the lowest viscosity, showed a larger dispersed phase size in the cross‐sectional SEM micrographs, maximum conductivity observed at higher draw ratios and a more linear resistance–voltage relationship than those of the fibers prepared using the higher viscosity matrices. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Inclusion of Carboxyl Function Inside of Cucurbiturils and its Use in Molecular Switches
Authors: Kolman Viktor , Kulhanek Petr , Sindelar Vladimir
Published: September 2010

We have prepared organic guest molecules in which two pyridinium rings are connected through an aromatic/aliphatic bridge bearing a carboxyl group. The supramolecular interactions between these guests and macrocyclic hosts cucurbit[7]uril (CB7) and cucurbit[8]uril (CB8) has been studied. We have demonstrated that the binding modes of the complexes depend on the type of central bridge present in the guest molecules and the size of the macrocycle. We have also showed that the binding mode between cucurbiturils and guests with aromatic bridges is pH independent. On the other hand, a guest containing an aliphatic bridge and CB7 formed a pseudorotaxane, which behaved as a pH‐driven molecular switch.
Sur quelques dérivés quaternaires du diaminométhyl‐dioxyméthyl‐méthane,
Authors: Govaert F. , Cazier J.
Published: September 2010

Subsequent to a preceding publication(1) entitled «Quaternary Ammoniumsalts of Tetraminotetramethylmethane», the authors give now the preparation of the quaternary base which derives from diaminomethyl‐dioxymethyl‐methane.

First they prepared the corresponding tertiary amine by the reaction of the dibromhydrine of pentaerythritol with dimethylamine at 115°. The yield is 70%. By addition of 2 molecules of methyliodide this substance is easily transformed into the quaternary ammoniumsalt.

The alcoholic functions of the tertiary amine were acetylated and the reaction product was converted into the corresponding quaternary ammoniumsalt.
Spektraalanalyse van Palladium in Platina
Authors: van Der Voort P.
Published: September 2010

Une méthode de purification du platine par réduction à l'acide formique, suivie de coprécipication du palladium par la salicylaldoxime en présence de cuivre, est décrite.

Le dosage spectrographique du palladium dans le platine est ensuite examiné tant du point persistance que précision. On compare à cet égard l'arc ordinaire, l'arc interrompu mécaniquement, l'étincelle et une nouvelle source d'émission: l'effluve sous pression atmosphérique. La persistance est la plus élevée dans l'arc (bille de platine sur anode), la reproductibilité des résultats la meilleure dans l'étincelle et l'effluve.
Contribution à l'étude du microdosage du carbone et de l'hydrogène
Authors: Lacourt Meelles , Crets Liliane
Published: September 2010

Le microdosage du carbone et de l'hydrogène est une technique qui dans sa forme primitive présente des difficultés de réalisation lorsqu'il s'agit d'analyser des substances organiques renfermant des éléments singuliers.

Des recherches destinées à perfectionner ce dosage ont été entreprises au Centre de Microchimie, un certain nombre de questions s'y rapportant ont dejà été traitées(1), d'autres sont encore à l'étude.

Dans le présent travail qui appartient à ce cycle de recherches, nous avons envisagé la réalisation de ce dosage par titrage. Un problème analogue a été avantageusement résolu dans le cas du microdosage de l'oxygène par hydrogénation, où apparaissent ègalemem de l'eau et de l'anhydride carbonique, mais ce dernier en petite quantité. Chaque molécule d'eau agissant sur un chlorure d'acide y libère 2 molécules d'acide chlorhydrique. Cet acide transporté en même temps que CO2de l'analyse, dans une pipe alcaline, peut y être titré en même temps que ce dernier. La différence des consommations alcalines à froid et à chaud conduit au résultat.

Jusqu'à quel point cette technique simple peut elle être étendue au microdosage du carbone et de l'hydrogène, alors que toutes choses égales, CO2y apparait en quantité de 30 à 70 fois plus grande que dans le dosage de l'oxygène?

Nos expériences actuelles semblent bien montrer que dans le cas du carbone et de l'hydrogène, il n'est pas possible de capter simultanément dans une seule pipe maintenue alcaline pendant toute la durée de l'expérience, l'acide chlorhydrique et l'anhydride carbonique formés.

Même en complétant l'appareillage de captation, cette technique titrimétrique, comme on le verra dans la partie expérimental, semble devoir conduire à des résultats très imprécis pour l'anhydride carbonique; elle néccssite d'ailleurs de longues manipulations et l'emploi d'une valeur à blanc considérable. La méthode gravimétrique reste donc jusqu'ici la plus avantageuse si l'on adopte la méthode de A. Friedrich (2. 3).

Cette dernière met en jeu en effet, une technique sure de gazéification de la matière organique, elle élimine les causes d'erreurs dues au remplissage universel de Pregl, celles de la pesée, par l'emploi d'un témoin et d'une tare unique, enfin elle élimine aussi la valeur à blanc, ce qui améliore considérablement le résultat. Celui‐ci est obtenu avec une approximation moyenne de 0,1% et les manipulations comportent une durée de 30 à 40 minutes.
De chemische Samenstelling van Kongoleesche Chaulmoograzaden en ‐vetten
Authors: Adriaens L.
Published: September 2010

Devant la nécessité de connaitre la composition chimique la plus exacte possible des huiles de chaulmoogra employées dans la médication de la lèpre, l'auteur s'est efforcé de déterminer la nature et la dose des différents acides gras fournis par les graines des Flacourtiacées indigènes ou introduites au Congo belge.

Il a étudié les graines et les beurres de Caloncoba Welwitschii, Caloncoba glauca, Lindackeria dentata, Hydnocarpus anthelmintica, Hydnocarpus Wightiana.

Les produits de décomposition, qui se trouvent dans les résidus de la distillation sont formés de ces composés que l'on trouve habituellement dans les graisses rances. Toutefois, vu la configuration spéciale des acides de chaulmoogra, l'existence d'acides lactoniques est fort probable; il importe de les éliminer le mieux possible dans les preparations médicinales.
A New Preliminary Treatment of Urine in Preparation to the Microdosage of Mercury, According to Stock
Authors: D'Hoork J.
Published: September 2010

Nous avons mis au point un nouveau traitement de l'urine, préalable au microdosage d'aprés Stock.

Le choix des réactifs s'imposait par leur faible teneur en mercure. 500 ml d'urine+5 mg de Cu (sol. aq. de CuSO4)+25 ml de H2O2 40% sont mélangés dans un Flacon conique d'un litre et chauffés au bain‐marie bouillant, aussi longtemps que des bulles gazeuses se dégagent. Après ce traitement, les urines ont généralement un aspect laiteux légèrement bleuâtre. Le précipité est constitué en majeure partie de phosphates de chaux et de magnésie. Si la couleur jaunâtre persiste, on laisse refroidir jusqu'à 50° C, on ajoute 5 ml d'H2O2 40% et on chauffe de nouveau au bain‐marie comme décrit plus haut.

A la solution chaude on ajoute 50 ml d'HCl 11 N et 2 ml d'H2O2 40%. et on continue de chauffer jusqu'au moment où tout déagement d'oxygène a cessé.

On laisse refroidir; on ferme le flacon au moyen d'un bouchon percé d'un court tube en verre, raccordé à un généateur d'H2S d'après Kipp. On laisse en connection pendant une heure, puis on laisse reposer pendant la nuit. Le lendemain le précipité est séparé au moyen d'un centrifugeur, lavé à l'eau chaude, et dissous par addition de 1 ml d'H2O2 et 3 ml d'HCl 11 N. On chauffe au bain‐marie pour éliminer tout le chlore libre, et on sépare le soufre sur un filtre en verre Jena 3 G 4. Le filtrat, contenant le mercure, peut être soumis à l'électrolyse.

La méthode à été controlée par l'analyse d'échantillons d'urine de même provenance, contenant des quantités connues de mercure.
Open Smeltpuntsbepaling Gebruik van het nieuw Smeltpuntsapparaat volgens Schaorl
Authors: Gillis J. , D'Hoore J.
Published: September 2010

L'appareil pour la détermination du point de fusion d'aprés Schoorl a êté étalonné avec quelques substances pures dont le point de fusion était ou bien connu d'avance comme point fixe, ou bien déterminé au moyen du micro‐appareil d'àpres Kofler. Une courbe des corrections a été établie.

L'appareil, qui est à la fois peu coûteux et simple à manier, donne d'excellents résultats, avec une précision qui est suffisante dans la plupart des cas pratiques.
Fonction et réactions des groupes sulfhydryles de la myosine
Authors: Frédéricq Eugène
Published: September 2010

1. — La méthode de dosage des groupes ‐SH totaux des protéines (Anson) est adaptée au cas de la myosine; elle fournit une valeur de 0,66% de cystéine, dans le cas de la dénaturation par le «Texapon»

2. — L'étude de l'action de la chloropicrine sur les groupes ‐SH de la myosine fournit une courbe mettant en relief la réactivité des groupes libres et cachés, à un PH voisin de la neutralité.

3. — La chloropicrine, l'isosulfocyanate d'allyle. la chloracétophénone, le sulfoxyde et la sulfone de ββ' dichloréthyle réagissent avec les groupes ‐SH de la myosine en laissant subsister la presque totalité de la biréfringence de flux.

4. — La viscosité de la myosine n'est que faiblement affectée par la réaction de la chloropicrine.

Ces deux derniers points montrent que la nouvelle molécule produite par la réaction de «blocage» des groupes ‐SH présente les caractères d'une protéine non dénaturée.
Dosage spectrographique du deutérium
Authors: Tiggelen A. Van
Published: September 2010

Hydrogen‐deuterium mixtures with a composition varying between 15 and 85% have been analysed spectrographically with a precision of 2% on the percentage of the minor constituent.

The mixture (under a pressure of 1, 5 mm Hg), enclosed in a Geissler tube with external electrodes, was submitted to a Tesla discharge. The composition was determined by measuring the relative intensities of the Hβ and Dβ lines on a photographic plate by the stepped sector method. The experimental curve, giving the isotopic content ratios is expressed by the equation:

Reproducible results could only be obtained when the Geissler tubes had been previously degassed during a few hours under high vacuum at 360° C.

Mercury vapour was eliminated by cooling the mixtures at —80° C before admission.

H2S — D2 and NH3 — D2 mixtures have also been analysed on deuterium content by the same method. It appears that the experimental curves differ to some extent when a foreign atomic species is present (in this case sulphur or nitrogen), the reproducibility is lower with the NH2 — D2 mixtures.

The equation expressing the experimental curves can partly be accounted for by assuming a preferential excitation of light hydrogen resulting from the difference in zero point energy between hydrogen and deuterium compounds.
La synthèse du méthane à partir d'anhydride carbonique et d'hydrogène sur le nickel
Authors: Nicolaiu J. , D'Hont M. , Jungers J. C.
Published: September 2010

Cette étude porte sur la cinétique de l'hydrogénation de l'oxyde de carbone et de l'anhydride carbonique sur le nickel dans un domaine de pression allant du dixième d'atmosphere à l'atmosphère et un intervalle de température de 180 à 300° C.

Les résultats obtenus antérieurement dans ce laboratoire sur la réaction de l'oxyde de carbone et de l'hydrogène ont été confirmés et étendus. La cinétique de la réaction s'interprète en admettant que l'hydrogène est plûtot faiblement et l'oxyde de carbone assez fortement adsorbé par le nickel. La vitesse de la réaction n'est pratiquement pas influencée par la présence des produits; elle est plus rapide si on emploie le deutérium au lieu de l'hydrogène.

L'interaction de l'hydrogène et de l'anhydride carbonique répond à une cinétique différente; les deux gaz sont assez faiblement adsorbés; les produits de la réaction en dépriment la vitesse; le deutérium se comporte sensiblement comme l'hydrogène.

Du point de vue de leur coefficient d'adsorption, on peut ranger les gaz impliqués dans ees réactions dans l'ordre:

Les deux réactions obéissent à la loi d'Arrhénius; ainsi qu'on peut le prévoir à partir de ces renseignements on trouve que l'hydrogénation de l'oxyde de carbone est plus lente et caractérisée par une énergie d'activation supérieure.

Ces conclusions se pre'tent à une vérification très nette. On peut prévoir que si on soumet à l'hydrogénation un mélange d'oxyde de carbone et d'anhydride carbonique, c'est le premier, plus fortement adsorbé, qui réagira le premier, cédant alors la place au second qui réagira plus rapidement. Tel est en effet le résultal de l'expérience.
Recherches sur le mécanisme des réactions catalytiques. V. Contribution à L'é de la Promotion
Authors: Herbo CI. , Hauchard V.
Published: September 2010

Un examen du concept «activité catalytique» conduit à la conclusion que l'activité d'un catalyseur dans une réaction déterminée doit s'exprimer par le coefficient cinétiquekdu processus élémentaire constituant l'éapela plus lente de la réaction globale. La fonctionk=f(T) permet de préciser si la variation d'activité d'un catalyseur à l'autre est due à un changement de la qualité ou de la quantité des centres actifs.

L'étude de l'activité d'une séerie de catalyseurs nickel‐oxyde de beryllium dans l'hydrogénation du benzène montre que le nombre de centres actifs varie d'un échantillon à l'autre tandis que la qualité de ces centres reste inchangée.

Lorsqu'on ramène la surface active à un poids constant de nickel, on constate qu'elle tend asymptotiquement vers un palier horizontal, si l'on ajoute à ce poids constant de nickel des quantités croissantes d'oxyde promoteur. L'allure de cette courbe semble indiquer qu'il s'agit non pas d'un effet de dispersion mais d'un effet de contact. La zone active serait constituée par les lignes séparant les phases nickel et oxyde de beryllium.

On développe ensuite une méthode de calcul permettant d'évaluer le nombre absolu de centres actifs. On arrive à la conclusion que la surface active par gramme de catalyseur est si petite que la mesure directe de la capacité °adsorption utile en catalyse est impossible.
Études sur L'Invertase
Authors: Dieu H.
Published: September 2010

Une méthode de fractionnement par l'alcool éthylique ou l'acétone d'autolysats d'invertase obtenus au départ de certaines levures de boulangerie, conduit assez rapidement à l'obtention de solutions d'invertase qui possèdent des temps‐valeurs de l'ordre de 0,059 minute alors que les plus bas renseignés dans la littérature sont de 0,069 minute (Albers et Meyers). I.e fractionnement est suivi en rapportant l'activité de ferment estimée, par une nouvelle technique de dosage basée sur l'évaluation des sucres réducteurs suivant Somogyi, à sa teneur en azote protéique déterminée par micro‐Kjeldahl.
Mesure du pH au Moyen d'un Amplificateur Balistique
Authors: Lasareff V.
Published: September 2010

The construction of a two‐stage impulse amplifier is described. The instrument referred to is especially adapted to pH measurements with a glass electrode of high resistance and shows a sensitivity of 1 millivolt. The advantages inherent in impulse amplifiers as compared with other thermionic voltmeters are emphasized.
Dosage semi‐microchimique des fibres cellulosiques en mélange avec la laine
Authors: Robinet Maurice
Published: September 2010

Le dosage des fibres cellulosiques en mélange avec la laine peut se faire par voie semi‐microchimique en utilisant le principe de la dissolution de la laine par l'hydroxyde sodique. Le procédé décrit permet, par l'emploi d'un matériel très simple, un dosage très rapide et suffisamment précis pour la pratique.

Les avantages de la méthode microchimique: rapidité d'exécution, emploi d'une faible quantité de substance, sont particulièrement appréciables dans certains cas de dosage de fibres cellulosiques en mélange avec la laine; on désire souvent obtenir très vite le résultat ou on ne peut enlever un grand échantillon du fil ou du tissu à analyser.

Cette considération nous a porté à établir une méthode semi‐microchimique qui, tout en présentant les avantages ci‐dessus, permette d'opérer avec le matériel normal de tout laboratoire d'analyse.

Le procédé a été spécialement mis au point pour des filés mixtes laine‐viscose, mais peut s'appliquer à tout mélange de laine avec matières insolubles dans l'hydroxyde sodique: rayonne ou fibranne cuproammoniacale, coton, lin, etc.
Synthèse et étude des deutérométhanols
Authors: Beersmans J. , Jungers J. C.
Published: September 2010

Le trideutérométhanol‐d (CD3OD) fut obtenu par synthèse catalytique à partir d'oxyde de carbone et de deutérium.

L'action du diazométhane sur l'eau lourde a fourni un mélange de différentes formes isotopiques au lieu du monodeutérométhanol‐d attendu (CH2DOD).

Le trideutérométhanol (CD3OH) fut préparé par réaction d'échange entre le trideutérométhanol‐d et l'eau légère.

Le méthanol‐d (CH3OD) fut obtenu par saponification de l'ester di‐méthyloxalique par l'eau lourde et le carbonate de soude.

Les mesures de tension de vapeur révèlent que l'introduction du deutérium dans le groupement méthyle élève la tension de vapeur; dans le groupement hydroxyle il la diminue.

Les chaleurs d'évaporation sont plus élevées (∼ 100 cal.) pour les méthanols‐d.

Les spectres Raman et infra‐rouges ont été mesurés et interprétés par M. de Hemptinne, Th. Doehaerd et Ch. Courtoy.
La recherche des acides α monoaminés monocarboxylés dans les hydrolysats protéiques par la spectrographie Raman II. La recherche de l'isoleucine dans la zéine
Authors: Renard M. , Hardy V.
Published: September 2010

La méthode qui a été exposée précédemment par l'un de nous, a été appliquée à la recherche de l'isoleucine dans la zéine. Les résultats obtenus montrent la présence de cet acide aminé dans la protéine en question.