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Background : The term "Intra-cranial space occupying lesion" (ICSOL) is defined as any neoplasm, benign or malignant, primary or secondary, as well as any inflammatory or parasitic mass lying within the cranial cavity. Advances in intracranial imaging have made the detection of intracranial lesions relatively accurate and enabling us to focus on the etiology of these space-occupying lesions. Many reports suggested that both incidence and pattern of intracranial space occupying lesions are subject to considerable geographic and racial variations. Knowledge of the regional peculiarities of these lesions will help in identifications of possible risk factors. Materials and Methods: This observational study was done in the department of medicine of Mymensingh medical college hospital, Bangladesh from November, 2011 to April, 2012 to evaluate the clinical pattern of ICSOL among the 75 adult admitted patients. Patient aged more than 15 years of either sex with symptoms and signs of ICSOL and at least one CT or MRI evidence in favour of diagnosis were included. Results: The highest participation (22.7%) was observed from 55-64 years age group. Mean age of the participants was 54.35±18.68 years. Neoplastic tumor was (25.8%) in 15-24 years age group and non neoplastic lesion was (31.8%) in 55-64 years age group, among participants (76.0%) came from rural areas and 24% from urban. Population regarding the occupation 30.7% were housewives, 21.3% were service holders and 20.0% are farmers. Headache was the most common symptom noted in 93.33% of patients. Nausea/ vomiting, difficulty in limb movement and imbalance were the other most common three symptoms. In this series intracerebral hemorrhage was found in 53.3% of patients, Astrocytoma was the second most common (20.0%). Meningioma was found in 8% of the participants and another 8% had metastatic lesions in their brain. There were two cases of schwanoma while tuberculoma was diagnosed in another two participants (2.7%). Conclusion: Patients with symptoms and signs of ICSOL should be dealt with great care and CT or MRI helps to evaluate them for early diagnosis and proper management. [ABSTRACT FROM AUTHOR]

Provides information on a study that investigated tangential phase matching for second-harmonic generation in beta barium borate and deuterated potassium dihydrogen phosphate crystals. Equation for the critical tangential phase-matching situtation in a negative uniaxial crystal; Details on the experiments; Cause of the introduction of noncollinearity.

The lifetimes of the excited levels for the two nearly degenerate bands of Ag106 have been measured using the Doppler-shift attenuation method. The deduced B(E2) and B(M1) rates in the two bands are found to be similar, except around the band crossing spin, while their moments of inertia are quite different. This is a novel observation for a nearly degenerate doublet band. [ABSTRACT FROM AUTHOR]

The lower reaches of the Sabarmati River Basin in Gujarat have intense agricultural and industrial activities and this part is affected by problems of groundwater salinity. Here we attempt to assess the processes governing the causes of groundwater salinity in the coastal alluvial aquifer, employing δ 18O and δ D isotopes in integration with ionic ratio. The different hydrochemical facies such Na-Mg-HCO3-Cl, Na-Cl-SO4, Na-Mg-Cl-HCO3-SO4 and Na-Cl of groundwater show the occurrence of complex geochemical phenomenon in the study area. Ionic ratio (such as Mg2+/Ca2+, Na+/Cl-, SO42-/Cl-, K+/Cl-) and isotopic composition (δ 18O and δ D) of groundwater indicate that while in coastal areas seawater intrusion is taking place, in inland areas various anthropogenic activities and overexploitation have induced salinity in groundwater. Over-pumping of groundwater has also induced lateral intermixing of highly saline water in the vicinity of coastal areas with relatively fresh/low saline groundwater along specific flow pathways. [ABSTRACT FROM AUTHOR]

Background It has been reported that patients with cutaneous malignant melanoma (CMM) can lower their risk of a second primary melanoma by limiting recreational sun exposure. Previous studies based on questionnaires and objective surrogate measurements indicate that before their diagnosis, patients with CMM are exposed to higher ultraviolet radiation (UVR) doses than controls, followed by a reduction after diagnosis. Objectives In a prospective, observational case-control study, we aimed to assess sun exposure after diagnosis of CMM by objective measurements to substantiate advice about sun behaviour. Methods The study population consisted of 24 patients recently diagnosed with CMM during the 7 months preceding the start of the study; 51 controls who matched these recently diagnosed patients in age, sex, occupation and constitutive skin type; and 29 patients diagnosed with CMM between 12 months and 6 years before the start of the study. During a summer season participants filled in sun exposure diaries daily and wore personal electronic UVR dosimeters in a wristwatch that continuously measured time-stamped UVR doses in standard erythema dose. Results The UVR dose of recently diagnosed patients on days with body exposure was one-third lower, and the number of days using sunscreen was double that of matched controls. However, in patients diagnosed more than 12 months earlier, the UVR dose on days with body exposure was one-third higher and the number of days using sunscreen was half that of recently diagnosed patients. Conclusions Patients with CMM limited their UVR dose on days with body exposure, and by using sunscreen further reduced UVR reaching the skin, although only immediately after diagnosis. [ABSTRACT FROM AUTHOR]

The present work uses a finite-element approach to study vibration, buckling, and dynamic instability characteristics in damaged cross-ply and angle-ply curved panels. The panels are subjected to nonuniform, centrally, and edge-distributed follower loading. First order shear-deformation theory was used to model the doubly curved panels and was formulated in accordance with Sanders' first approximation. An anisotropic damage formulation was used to model damage. An analysis was carried out on plate and shallow shells to obtain vibration, buckling, and static instability (i.e., divergence) and dynamic instability (i.e., flutter) behavior. The effects of load type, load width, damage, and damage location on natural frequency, buckling load, divergence load, flutter load and flutter frequency were studied. The effect of curvature to improve the stability characteristics of panels is discussed. The desirable position of damage on a panel is discussed on the basis of different stability behavior. Results indicate that narrow edge loading is undesirable in most cases. [ABSTRACT FROM AUTHOR]

In India, for food security, the future agriculture faces the challenge of enhancing crop production under uncertain climatic extremes, in a limited (or degraded at many places) land area, with more and more requirement of water (in many places, poor quality water), complexities and rapid erosion of natural biodiversity and agricultural systems, and the socio-economic systems governing food supply and demand. Plant attributes conferring good yields, under fast-depleting/deteriorating natural resource base, are yet to be identified. Breeding for crop improvement, for higher quality, production, heat and water stress resistance, has met with limited success. It is well known that despite planting the improved genetic varieties, and application of the recommended doses of fertilizers and agronomic practices, the dormant seed gets its vigour only in the presence of water. But, reliable assessment of this important resource base and its protection from depletion and degradation has not received its due consideration in the management of agriculture. In this context, analyses of agricultural information reported in the literature, clearly suggest that proper water management can only help in enhancing future food production. Policy guidelines have also been suggested for ensuring food security. [ABSTRACT FROM AUTHOR]

The oxidation behaviour of CrAlYN (at.%) thin film deposited on γ-TiAl based alloy Ti-45Al-8Nb (at.%) was carried out. The tests were performed in the temperature range 750-950 °C for 500 h. The materials showed good corrosion resistance only at temperatures of 750 and 850 °C where AlO and CrO phases developed as a top oxide scale. A lack of corrosion resistance was observed at 950 °C where a thick scale (100 μm) that developed consisted of alternate layers of TiO and AlO phases. To investigate the oxidation behaviour, the corrosion kinetics were determined by means of discontinuous gravimetry of the exposed samples. Surface and cross-sectional analyses of exposed samples were conducted using scanning electron microscopy (SEM) and energy X-ray dispersive spectroscopy (EDS). [ABSTRACT FROM AUTHOR]

Abstract: Ribbon synapses of the vertebrate retina are specialized synapses that release neurotransmitter by synaptic vesicle exocytosis in a manner that is proportional to the level of depolarization of the cell. This release property is different from conventional neurons, in which the release of neurotransmitter occurs as a short-lived burst triggered by an action potential. Synaptic vesicle exocytosis is a calcium regulated process that is dependent on a set of interacting synaptic proteins that form the so-called SNARE (soluble N-ethylmaleimide sensitive factor attachment protein receptor) complex. Syntaxin 3B has been identified as a specialized SNARE molecule in ribbon synapses of the rodent retina. However, the best physiologically-characterized neuron that forms ribbon-style synapses is the rod-dominant or Mb1 bipolar cell of the goldfish retina. We report here the molecular characterization of syntaxin 3B from the goldfish retina. Using a combination of reverse transcription (RT) polymerase chain reaction (PCR) and immunostaining with a specific antibody, we show that syntaxin 3B is highly enriched in the plasma membrane of bipolar cell synaptic terminals of the goldfish retina. Using membrane capacitance measurements we demonstrate that a peptide derived from goldfish syntaxin 3B inhibits synaptic vesicle exocytosis. These experiments demonstrate that syntaxin 3B is an important factor for synaptic vesicle exocytosis in ribbon synapses of the vertebrate retina. [Copyright &y& Elsevier]

This paper deals with the study of dynamic or parametric instability behavior of laminated composite stiffened plates with step-uniform and concentrated in-plane harmonic edge loading. The eight-noded isoparametric degenerated shell element and a compatible three-noded curved beam element are used to model the plate and the stiffeners, respectively. The method of Hill’s infinite determinant is applied to analyze the dynamic instability regions. Numerical results are presented through convergence and comparison with the published results from the literature. The effects of parameters like loading type, stiffening scheme, lamination scheme, dynamic load factor, and boundary conditions are considered in the dynamic instability analysis of laminated composite stiffened plate. It has been shown that the type of loading and the width of loading have remarkable effect on the dynamic instability characteristics of the stiffened plate. [ABSTRACT FROM AUTHOR]

Background: The resistance to antimicrobial agents among Staphylococci is an increasing problem. The resistance to macrolide can be mediated by msr A gene coding for efflux mechanism or via erm gene encoding for enzymes that confer inducible or constitutive resistance to macrolide, lincosamide and Type B streptogramin. Aim: The present study was aimed to find out the percentage of Staphylococcus aureus having inducible clindamycin resistance (iMLSB) in our geographic area using D-test. Also, we tried to ascertain the relationship between Methicillin-resistant Staphylococcus aureus (MRSA) and inducible clindamycin resistance, association of these iMLSB isolates with community or nosocomial setting and treatment options for these iMLSB isolates. Settings and Design: A total of 200 non-duplicate Staphylococcus aureus isolates from various clinical samples from both outdoor and indoor patients were studied. Materials and Methods: Susceptibility to routine antimicrobial agents was carried out using Kirby Bauer method. Methicillin resistance was detected by oxacillin disc on Mueller Hinton agar (MHA) supplemented with 2% NaCl. D-test was performed on all erythromycin-resistant and clindamycin-sensitive Staphylococcus aureus strains to detect inducible clindamycin resistance. Results: Among 200 Staphylococcus aureus strains, 50 (25%) were found to be MRSA and 36 were D-test positive. Also, MRSA isolates showed both higher inducible resistance and constitutive resistance to clindamycin as compared to Methicillin-sensitive Staphylococcus aureus (MSSA). Out of 36 isolates of Staphylococcus aureus showing inducible clindamycin resistance, 24 were from the outpatient department and 12 were recovered from indoor patients. All isolates of Staphylococcus aureus showed 100% sensitivity to vancomycin and linezolid. Conclusions: Clindamycin is kept as a reserve drug and is usually advocated in severe MRSA infections depending upon the antimicrobial susceptibility results. We have reported a higher incidence of iMLSB from both community (66.67%) as well as hospital (33.33%) setup. Therefore clinical microbiology laboratory should report inducible clindamycin resistance routinely. [ABSTRACT FROM AUTHOR]

A finite element dynamic instability analysis of stiffened shell panels with cutout subjected to uniform in-plane harmonic edge loading along the two opposite edges is presented in this paper. The eight-noded isoparametric degenerated shell element and a compatible three-noded curved beam element are used to model the shell panels and the stiffeners, respectively. As the usual formulation of degenerated beam element is found to overestimate the torsional rigidity, an attempt has been made to reformulate it in an efficient manner. Moreover the new formulation for the beam element requires five degrees of freedom per node as that of shell element. Bolotin method is applied to analyze the dynamic instability regions. Numerical results of convergence studies are presented and comparison is made with the published results from literature. The effects of various parameters such as shell geometry, radius of curvature, cutout size, stiffening scheme. and dynamic load factors are considered in dynamic instability analysis of stiffened shell panels with cutout. The free vibration and static stability (buckling) results are also presented. With the consideration of radius of curvatures the panels reduce from deep shell case to shallow shell case and finally become flat plate. [ABSTRACT FROM AUTHOR]

The present study investigates the conditions required for forming a hybrid coating consisting of an outer nickel aluminide layer and an inner nickel layer on alloy steels. A commercial alloy steel of 9Cr-1Mo was used as a substrate. Electroless and electronickel plating processes were used to form an initial nickel layer on the steel. The AlCl3 activated packs containing pure Al as a depositing source were then used to aluminise the nickel deposit at temperatures ≤650°C. The effect of phosphorus or boron content in the initial nickel layer deposited with the electroless nickel plating solutions using hypophosphite or boron-hydrogen compound as reducing agent was investigated in relation to the spallation tendency of the coating either immediately after the aluminising process or during the thermal annealing post-aluminising process. Under the aluminising conditions used, the outer nickel aluminide layer formed was Ni2Al3. For the electroplated nickel deposit, the growth kinetics of the outer Ni2Al3 layer during the pack aluminising process was found to obey the parabolic rate law with a parabolic rate constant being 12.67 µm at 650°C for 2 wt-%AlCl3 activated pack containing 4 wt-% pure Al as a deposition source. [ABSTRACT FROM AUTHOR]

Organizational characteristics in English NHS hospitals and the experiences of patients with three common cancers – breast, colorectal and lung – were examined using secondary data analyses. Two specific measures of satisfaction, Respect and Dignity, reflecting inpatient care, and Communication reflecting hospital outpatient care, were drawn from a national survey of cancer patients after first hospital treatment. They were compared at hospital level with hospital cancer service standards, and measures of hospital provision, each drawn from national surveys. Respect and Dignity was greater in hospitals with fewer complaints, slower admission procedures and a greater proportion of medicine consultants, for breast and colorectal cancers only. For breast cancer alone, Respect and Dignity was greater in hospitals achieving more participation in meetings by lead team members at the cancer unit level. For lung cancer alone, there were tumour-specific team organizational measures (relating to outpatient assessment) associated with Communication. However, the majority of recorded standards did not show associations, and there were occasional negative associations (dissatisfaction). The impact of organizational factors on patients may be examined through observational studies when experimental designs are not possible. Understanding how organizational factors affect quality of care for cancer patients can contribute to planning and management of cancer services. [ABSTRACT FROM AUTHOR]

The dynamic instability of doubly curved panels with a centrally located circular cutout, subjected to nonuniform compressive in-plane harmonic edge loading is investigated. The present work deals with the problem of the occurrence of combination resonances in contrast to single (mode) resonances in parametrically excited doubly curved panels with a central circular cutout. The method of multiple scales is used to obtain analytical expressions for the single (mode) and combination resonance instability regions. It is shown that other cases of the combination resonance can be of major importance and yield a significantly enlarged instability region in comparison to the principal instability region. The effects of nonuniform edge loading, centrally located circular cutout, damping, the static, and dynamic load factors on dynamic instability behavior of simply supported doubly curved panels are studied. The results show that under localized edge loading, combination resonance zones are as important as single (mode) resonance zones. The effects of damping show that there is a finite critical value of the dynamic load factor for each instability region below which doubly curved panels cannot become dynamically unstable. A central circular cutout has the destabilizing effect on the dynamic stability behavior of doubly curved panels subjected to nonuniform edge loading. This example of simultaneous excitation of two modes, each oscillating steadily at its own natural frequency, may be of considerable interest in vibration testing of actual structures. [ABSTRACT FROM AUTHOR]

Objective: To investigate whether cancer service standards are associated with survival for breast, colorectal and lung cancers at population level. Methods: Standards of hospital cancer services in England, measured in 2001, were aggregated for 30 cancer networks covering populations of between 500 000 and 3 million people, and compared with 1-year and 5-year relative cancer survival for the incident period 1996-2001, using rank correlation. Results: Relative survival and the cancer standards each showed statistically significant differences across cancer networks. For tumour-specific services, the total score of 35 standards was associated with longer relative survival for both colorectal and lung cancers (p<0.05), but not breast cancer, while colorectal cancer survival was strongly (p<0.01) associated with the specific standard "written agreement describing referral guidelines", and lung cancer (p<0.05) with two other guideline standards. There were also associations of longer survival with two measures of nursing staff specialist qualifications. Compliance with general standards for cancer services was not associated with survival for breast cancer, and showed only borderline {p<0.1) associations for colorectal cancer, while some standards on medical and management lead staff were significantly associated (p<0.05) with poorer survival for lung cancer. Overall, compliance with standards for hospital pathology and radiology services also showed no associations with survival. Conclusion: This study suggests that compliance with some clinical service standards, such as guidelines, could contribute to better survival at population level, while more general organisational aspects of cancer services may not directly improve survival. [ABSTRACT FROM AUTHOR]

Treatment with interferon-β (IFN-β) induces the expression of hundreds of genes in blood mononuclear cells, and the expression of several genes has been proposed as a marker of the effect of treatment with IFN-β. However, to date no molecules have been identified that are stably induced by treatment with IFN-β. We use DNA microarrays to study gene expression in 10 multiple sclerosis (MS) patients who began de novo treatment with IFN-β. After the first injection of IFN-β, the expression of 74 out of 3428 genes changed at least two-fold and statistically significantly (after Bonferroni correction). In contrast, we observed no persisting effects of IFN-β on gene expression. Among the most strongly induced genes was MXA, which has been used in previous biomarker studies in MS. In addition, the study identified the induction of LGALS9 and TCIR1G, involved in negative regulation of T helper type I immunity and T-cell activation, as novel effects of IFN-β therapy in MS. [ABSTRACT FROM AUTHOR]

Abstract: A new series of group 6 carbonyl complexes of N-[(2-pyridyl)methyliden]-α (or β)-aminonaphthalene (α/β-NaiPy) are described in this work. The complexes are formulated as cis-[M(CO)4(α/β-NaiPy)] by elemental, mass and other spectroscopic data. The complexes show emission spectra at room temperature and their quantum yield lies between 0.4 and 0.5. All the complexes exhibit negative solvatochromism. Cyclic voltammetry shows metal centred oxidation and ligand reductions. [Copyright &y& Elsevier]

Application of diazotrophic cyanobacteria, Anabaena variabilis, as biofertilizer for rice cultivation has a beneficial effect on crop productivity and maintenance of soil fertility. However, periodic applications of herbicides used to obtain high crop productivity are not only detrimental to weeds but to biofertilizer strains of cyanobacteria also. Therefore, research was undertaken to isolate four herbicide resistant strains (Arozin-R, Alachlor-R, Butachlor-R and 2,4-D-R) and a multiple herbicide resistant strain (MHR) of natural isolates of A. variabilis exhibiting resistance against these common rice field herbicides. The outdoor survivability of mutant strains and the productivity of rice crop (IR-36) were evaluated by inoculating the wild type and herbicide resistant mutant strains of A. variabilis in the presence and absence of recommended field dosages of test herbicides. No difference in survival and biofertilizer potentials of the herbicide resistant strains was observed in herbicide treated or in untreated conditions. Highest survivability (87%) was exhibited by MHR relative to other mutants. Highest growth and grain yield (76%) were recorded in plants treated with MHR as compared to uninoculated control rice plants. In conclusion, the mutant strains of A. variabilis had stable resistance to herbicides under outdoor conditions in flooded soils. Not only did the herbicide resistance strains increase growth of rice relative to the uninoculated pots, they were more beneficial for rice growth than the wild type strain. [ABSTRACT FROM AUTHOR]

This article investigates complexity and approximability properties of combinatorial optimization problems yielded by the notion of Shared Risk Resource Group (SRRG). SRRG has been introduced in order to capture network survivability issues where a failure may break a whole set of resources, and has been formalized as colored graphs, where a set of resources is represented by a set of edges with same color. We consider here the analogous of classical problems such as determining paths or cuts with the minimum numbers of colors or color disjoint paths. These optimization problems are much more difficult than their counterparts in classical graph theory. In particular standard relationship such as the Max Flow - Min Cut equality do not hold any longer. In this article we identify cases where these problems are polynomial, for example when the edges of a given color form a connected subgraph, and otherwise give hardness and non approximability results for these problems. [ABSTRACT FROM AUTHOR]

In this study, the results from three Nordic linkage disequilibrium screens in multiple sclerosis (MS) were investigated, in a new sample set of 314 Nordic MS trios from Denmark, Norway, Sweden and Iceland. Among 30 non-HLA and two HLA microsatellite markers individually genotyped, eight markers displayed distorted transmission with uncorrected P-value

Abstract: A new series of Cr(0)- and Mo(0)-carbonyl complexes of 1-alkyl-2-(naphthyl-α/β-azo)imidazoles (α/β-NaiR′) are described in this work. The complexes are formulated cis-[M(CO)4(α/β-NaiR′)] by elemental, mass and other spectroscopic data. The complexes are stable and exhibit emission spectra at room temperature. Cyclic voltammetry shows two metal centred oxidations, M+/M0 and M2+/M+, and two ligand centred reductions, azo/azo− and azo−/azo=. [Copyright &y& Elsevier]

The pack aluminisation process is normally applied at temperatures >973 K at which the mechanical properties of alloy steels would degrade. Thus, the present study was undertaken to apply this process to aluminising the alloy steels at temperatures <973 K in order to increase their high temperature oxidation resistance while maintaining their microstructure and hence mechanical strength and creep resistance. A type of commercial alloy steel P92 (9Cr–1Mo) was used for the present study. Pack powder mixtures consisting of Al, AlCl3 (anhydrous) or NH4Cl and Al2O3 were used to carry out the process. The aluminising temperature was varied from 773 to 973 K, pack Al content from 1 to 30 wt-% and aluminising time from 1 to 16 h to investigate their effects on the coating growth kinetics in the AlCl3 activated packs. It was observed that all the coatings formed in the AlCl3 activated packs were of a single layer structure with Fe2Al5 as the main coating phase. It was established that the interrelationship between the thickness h (in μm) of this coating layer and aluminising temperature T (in K), time t (in h) and pack Al content W (in wt-%) can be described by h=83005·9W1/2t1/2e-73330/(RT). In the NH4Cl activated packs, it was found that coating formation and dissolution took place simultaneously at 923 K and stable growth of a coating layer was only possible when the pack Al content was sufficiently high. However, the coatings formed in these packs had highly uneven regions. [ABSTRACT FROM AUTHOR]

This paper is concerned with the problem of occurrence of combination resonances in parametrically excited doubly curved panels. The dynamic instability of doubly curved panels, subjected to non-uniform in-plane harmonic loading is investigated. Sander's first-order shear deformation theory is used to model the doubly curved panels, considering the effects of transverse shear deformation and rotary inertia. The theory can be reduced to Love's and Donnell's theories by means of tracers. Analytical expressions for the instability regions are obtained at Ω = ωm + ωn (Ω is the excitation frequency and ωm and ωn are the natural frequencies of the system), by using the method of multiple scales. It is shown that besides the principal instability region at Ω =2ω1, where ω1 is the fundamental frequency, other cases of Ω = ωm + ωn which are related to other modes, can be of major importance and yield a significantly enlarged instability region. The results show that under localized edge loading, combination resonance zones are as important as simple resonance zones. The effects of edge loading, curvature, shallowness ratio, edge length to thickness ratio, aspect ratio, boundary conditions and the static load factor on dynamic instability regions are considered. [ABSTRACT FROM AUTHOR]

This is a detailed study aimed to understand the effects of pack composition on the formation and growth of aluminide coatings on alloy steels by pack aluminisation at 650°C, a temperature below the melting point of Al (660°C), using pack powders consisting of Al as depositing source, a halide salt as an activator and Al2O3 as inert filler. The packs activated by AlCl3, NH4Cl, AlF3 and NH4F were used to investigate the effects of the type of halide salt on the coating formation and growth process and subsequently to identify the most suitable activator for pack aluminising alloy steels at 650°C. The effects of pack Al content on the rate of coating growth were then studied by varying the pack Al content from 1.4 wt% to 10 wt% whilst fixing the pack activator content at 2 wt%. It was observed that among the halide salts studied, AlCl3 is the only suitable activator for pack aluminising alloy steels at 650°C and the rate of coating growth increases with the pack Al content. The equilibrium partial pressures of vapour species generated at the deposition temperature in packs activated by different types of halide salts were calculated and the results were discussed in relation to the observed deposition tendency of packs activated by different types of activators. A vapour phase transportation model was applied to elucidate the relationship between the rate of coating growth and the pack Al content. It was also demonstrated that by combining the low temperature pack aluminising parameters identified in this study with electroless or electro Ni plating, coherent nickel aluminide coatings free of microcracking can be produced on alloy steels at 650°C. [ABSTRACT FROM AUTHOR]

The present paper is concerned with the vibration, buckling and dynamic instability behavior of laminated composite, cross-ply, doubly-curved panels with a central circular hole subjected to in-plane static and periodic compressive loads. A generalized shear deformable Sanders' theory is used to model the curved panels, considering the effects of transverse shear deformation and rotary inertia. Bolotin's approach is used for studying the dynamic instability regions of doubly-curved panels. The effects of non-uniform edge loads, curvature with different cutout ratios, static and dynamic load factors, and lamination parameters on curved panels are investigated with the results discussed. [ABSTRACT FROM AUTHOR]

Dynamic instability of a beam is solved for second regions of instability. The governing equations are of the Mathieu–Hill type, where the parametric regions are sought. While the solution to the first region of a beam has been widely reported, there is none available in the literature for the second region. In this work, the regions are determined by the finite element method. Bolotin determined the solution analytically, but it is more of a qualitative solution of the problem. In this work, a quantitative solution is sought from the finite element method. The width of the regions are significant. The effects of the static load factor and the dynamic load factor are obtained. [ABSTRACT FROM AUTHOR]

The pack aluminising process is normally conducted on alloy steels at temperatures higher than 900°C at which mechanical properties of steels would degrade. This study aims to investigate the feasibility of pack aluminising a commercial 9Cr – 1Mo alloy steel at 650°C in an attempt to increase its high temperature oxidation and corrosion resistance without adversely affecting its mechanical properties and consequently to increase its long-term structural operating temperatures to up to 700°C. It was demonstrated that this could be achieved using packs containing AlCl3 as an activator and elemental Al as a depositing source. The coatings formed under these conditions consisted of an outer Fe14 Al86 layer and an inner FeAl3 layer with an abrupt interface between the coating and substrate, suggesting that the coating is formed via a mechanism of the inward Al reaction – diffusion. The pack Al content was varied from 1 to 6 wt-% to investigate its effects on the coating formation process. It was found that the pack Al content in this range affected only the coating thickness and therefore the growth rate of the coating, but not the surface Al concentration. A post-aluminising heat treatment study was also undertaken for an aluminised specimen at 650°C under an argon atmosphere to investigate the kinetics of converting the brittle Fe14 Al86 and FeAl3 phase layers to a more ductile FeAl phase layer. It was observed that this was a slow process requiring 1132 h for an initial coating layer thickness of 33μm. The coating after the conversion consisted of a uniform top FeAl layer with all other alloying elements in the solid solution and a diffusion zone underneath. [ABSTRACT FROM AUTHOR]

Molybdenum-containing catalysts are mostly used in petroleum-refining industries for mild hydrogenation processes. These catalytic processes generate huge quantity of spent catalyst. With the increasing demand of metal values and environmental awareness, catalysts can serve as a secondary source for metal recovery.Spent hydro-refining catalyst mainly consists of 10–20% MoO3, 6–8% CaO, 0–12% V2O5, 0.5–6% NiO, 10% S, 10–12% carbon and the balance is Al2O3. The spent catalyst was roasted with soda ash to convert molybdenum into a water-soluble compound. Various parameters like temperature, time and soda ash addition have been studied thoroughly and conditions for the maximum recovery of molybdenum have been established. It has been found that at 600 °C with 30 min of retention time and using 12 wt.% soda ash, it is possible to extract 92% of molybdenum from the spent catalyst. The molybdenum is extracted as sodium molybdate. This sodium molybdate is further purified using carbon adsorption method to obtain a pure grade of molybdenum trioxide. [Copyright &y& Elsevier]

Vibration characteristics of stiffened plates with cutouts subjected to uni-axial in-plane uniform edge loading at the plate boundaries are investigated using the finite element method. The characteristic equations for the natural frequencies, buckling loads and their corresponding mode shapes are obtained from the equation of motion. The vibration frequencies and buckling load parameters for various modes of stiffened plates with cutouts have been determined for simply supported and clamped edge boundary conditions. In the structure modelling, the plate and the stiffeners are treated as separate elements where the compatibility between these two types of elements is maintained. Numerical results are presented for a range of hole to plate width ratios of 0 to 0.8. The correlations of the natural frequencies and buckling parameters obtained by the present approach with those available in the literature are found to show good agreement. [ABSTRACT FROM AUTHOR]

The present investigation deals with the dynamic stability behavior of laminated composite curved panels with cutouts subjected to in-plane static and periodic compressive loads, analyzed using the finite element method. A generalized shear deformable Sanders’ theory with tracers is used in this study. Numerical results obtained for vibration and buckling of composite panels with cutouts compare well with literature. The principal dynamic instability region of composite perforated panels is obtained using Bolotin’s approach. The study reveals that curved panels with cutouts depict higher stiffness with the addition of curvatures. The laminated hyperbolic paraboloid panel shows the highest stiffness with the onset of instability at higher excitation frequencies. The effect of curvature in laminated composite curved panels is reduced with an increase in size of the cutout. The principal instability regions are influenced by the lamination parameters. Thus, the laminate construction, coupled with cutout geometry, can be used to the advantages of tailoring during design of composite structures for practical applications. [ABSTRACT FROM AUTHOR]

The vapour phase compositions of a series of pack powder mixtures containing elemental Al and Hf or W powders as depositing sources and CrCl3·6H2O or AlF3 or CrF3 as activators were analysed in an attempt to further develop the pack cementation process to codeposit Al and Hf or W to form diffusion coatings on nickel base superalloys. The results suggested that Al could be codeposited with Hf, but not with W, from the vapour phase. Compared with both AlF3 and CrF3, CrCl3·6H2O has been shown to be a more suitable activator for codepositing Al with Hf. The optimum coating temperature was identified to be in the range of 1050°C to 1150°C. Based on the thermochemical analysis, a series of coating deposition studies were undertaken, which confirmed that codeposition of Al and Hf could be achieved at a deposition temperature of 1100°C in the CrCl3·6H2O activated packs containing elemental Al and Hf powders. The coating obtained had a multilayer structure consisting of a Ni7Hf6Al16 top layer and a NiAl layer underneath, followed by a diffusion zone, which revealed that the coating was formed by the outward Ni diffusion. It is suggested that the compositions suitable for codeposition of Al and Hf could be effectively identified by comparing the vapour pressures of HfCl4 and HfCl3 with that of AlCl in the packs activated by chloride salts. It has also been experimentally demonstrated that, although W could not be deposited from the vapour phase, a high volume of fine W particles can be entrapped into the outer NiAl coating layer formed by the outward Ni diffusion using a modified pack configuration. This leads to the formation of a composite coating layer with W particles evenly distributed in a matrix of NiAl. It is suggested that this modified pack process could be similarly applied to develop nickel aluminide coatings containing other refractory metals that may not be codeposited with Al from the vapour phase. [ABSTRACT FROM AUTHOR]

The equilibrium partial pressures of vapour species generated in halide activated pack powder mixtures at high temperatures were calculated for a series of compositions using thermochemical analysis tools. The results obtained were applied to identify suitable activators and pack compositions for codepositing Al and Si to form diffusion coatings on nickel base superalloys by the pack cementation process. The calculation results suggested that compositions of the packpowder mixtures activated by CrCl[sub 3].6H[sub 2]O may be adjusted to create deposition conditions favourable for codepositing Al and Si, but, those activated byAlF[sub 3]or AlCl[sub 3] may only deposit Al.A series of coating deposition experiments were also carried out at 1000 ° C and 1100 ° C and the results obtained confirmed that, with adequate control of pack compositions and deposition conditions, codeposition of Al and Si can be achieved with CrCl[sub 3].6H[sub 2]O activated pack powder mixtures. A mixture of elemental Al and Si powders may be used as a depositing source instead of using Al-Si master alloy powders as conventionally recommended. The coatings could be formed either through the inward diffusions of Al and Si or through the outward diffusion of Ni together with other substrate elements such as Cr and Co, depending on the deposition temperature used. Prolonged deposition at 1100 ° C ledtothe formationofa coatingwith amultilayeredstructure consistingofanouter nickelsilicide layerand a middle Simodified NiAl layer followed by a diffusion zone. The pack compositions and deposition conditions may be adjusted to control the microstructure of the coatings formed by the codeposition process. [ABSTRACT FROM AUTHOR]

A higher bed height - up to 680 mm, including a 30 mm hearth layer of sized return sinter - and high suction below the grate bars up to 1400 mm WG have resulted in increasing productivity to 33 t m[sup -2]/day and have reduced the coke rate to a level of 46 kg t[sup -1] sinter. Ferro wastes such as blue dust, flue dust, mill scale, collection from dust catcher and gas cleaning plant, have been successfully added to the charge mix to produce quality sinters. In this paper, work carried out at the Regional Research Laboratory (CSIR) over the last few years is briefly descibed and two case studies are discussed, including the successful development of pan sintering units. [ABSTRACT FROM AUTHOR]

The finite difference time domain method is applied for the analysis of coupled microstrip lines with multiple right angle bends. The uniaxial perfectly matched layer (UPML) boundary condition is used to absorb outward waves. The UPML parameters are optimized to obtain absorption of both propagating and evanescent waves. It is also shown that this optimization increases the cutoff time and makes it possible to simulate the structures for a larger number of time steps. © 2002 Wiley Periodicals, Inc. Int J RF and Microwave CAE 12, 508–519, 2002. Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mmce.10051 [ABSTRACT FROM AUTHOR]

The Clover detectors in their addback mode are excellent tools for detecting high-energy gamma rays (&ges;2 MeV). The characteristics of these detectors, at energies above 2 MeV, are usually determined from simulation data or from extrapolation of the empirical data. This is the first time that the characteristics of a Compton suppressed Clover germanium detector have been studied up to 5 MeV using a radioactive 66Ga (T1/2=9.41 h) source. [Copyright &y& Elsevier]

The buckling and vibration behaviour of curved panels subjected to various in-plane tensile edge loadings are studied using the finite element method. The first order shear deformation theory is used to model the doubly curved panels, considering the effects of transverse shear deformation and rotary inertia. The theory used is extended from the dynamic, shear deformable theory based on the Sander's first approximation for doubly curved shells, which can be reduced to Love's and Donnell's theories by means of tracers. The in-plane non-uniform internal stresses are obtained as the plane elasticity solution with reasonable accuracy, based on which the buckling and vibration results are obtained. The effects of different edge loadings, aspect ratio, thickness ratio, shallowness parameters are considered in the buckling and vibration analysis. [ABSTRACT FROM AUTHOR]

The vibration and dynamic instability behavior of a stiffened plate subjected to uniform in-plane edge loading is studied using finite element analysis. The method of Hill's infinite determinants is applied to analyze the dynamic instability regions. Rectangular stiffened plates possessing different boundary conditions, aspect ratios, varying mass and stiffness properties and varying number of stiffeners have been analyzed for dynamic instability. The results are obtained considering the bending displacements of the plate and the stiffener. Eccentricity of the stiffeners give rise to axial and bending displacement in the middle plane of the plate. The results show that the principal instability regions have a significant effect considering and neglecting in-plane displacements. Comparison with published results indicates good agreement. [ABSTRACT FROM AUTHOR]

The parametric instability behaviour of curved panels with cutouts subjected to in-plane static and periodic compressive edge loadings are studied using finite element analysis. The first order shear deformation theory is used to model the curved panels, considering the effects of transverse shear deformation and rotary inertia. The theory used is the extension of dynamic, shear deformable theory according to Sanders'' first approximation for doubly curved shells, which can be reduced to Love''s and Donnell''s theories by means of tracers. The effects of static and dynamic load factors, geometry, boundary conditions and the cutout parameters on the principal instability regions of curved panels with cutouts are studied in detail using Bolotin''s method. Quantitative results are presented to show the effects of shell geometry and load parameters on the stability boundaries. Results for plates are also presented as special cases and are compared with those available in the literature. [Copyright &y& Elsevier]

Frequency-dependent scattering matrices for the composite transmission structures of single microstrip lines having two right-angle bend discontinuities have been determined. The scattering parameters found by a mode-matching technique are used in the computations of the time domain responses for trapezoidal pulse inputs. From the time domain responses the delays, distortions and reflections are found. The contributions of higher-order modes, which may be significant in deciding the signal flow behaviour in these types of transmission structure, are also identified. [ABSTRACT FROM AUTHOR]

Purpose: Angiotensin II receptor antagonists are effective in the prophylaxis of radiation nephropathy. Studies were designed to determine whether TGF- beta 1, a fibrogenic cytokine, plays a role in mediating the protective effect of AII antagonism. These studies explored the time-course of glomerular TGF- beta 1 production in the irradiated kidney, and whether AII mediates TGF beta 1 production in glomeruli isolated from irradiated rats. Materials and methods: Rats received 20Gy of bilateral renal irradiation in five fractions and were randomized to receive an AII type 1 receptor antagonist (L-158,809) at 20mg/l in their drinking water, or no treatment. Drug therapy began 9 days prior to irradiation and continued for the duration of the study. Results: Analysis of renal function showed a significant increase in urinary proteinuria and blood urea nitrogen by 37 days and 63 days after irradiation, respectively. Estimation of glomerular TGF- beta 1 levels by quantitative sandwich enzyme immunoassay technique revealed a significant increase in latent but not active TGF- beta 1 levels at 50 days and 63 days after irradiation. In animals treated with the AT1 receptor antagonist, there was a complete elimination in the rise of TGF- beta 1. Conclusions: These studies demonstrate that glomerular TGF- beta 1 production is elevated in the course of radiation nephropathy, and that AII mediates this induction of TGF- beta 1. [ABSTRACT FROM AUTHOR]

Pure titanium and Ti-6Al-4V were exposed at 750°C in an H/HO/HS P≈10 Pa and P≈10 Pa), H/HO (P≈10 Pa) and air environments for up to 240 hr. The corrosion kinetics, obtained by the discontinuous gravimetric method, showed that the sulfidation/oxidation kinetics were linear for Ti and linear-parabolic for Ti-6Al-4V in the H/HO/HS environment. Both materials obeyed parabolic rate laws in the H/HO atmosphere after a transient period, and linear-parabolic rate laws in air. After exposure to the H/HO/HS atmosphere, the titanium specimen displayed a double scale of TiO with an intervening TiS film between the double-layered scale of TiO and the substrate. Ti-6Al-4V also contained a double layer of TiO together with a stratum consisting of AlS, TiS and vanadium sulfide at the junction of the inner TiO layer and substrate. Some AlO precipitated in the external portion of the outer TiO layer. Following oxidation in the low-P atmosphere a double-layered oxide of TiO scale formed on both Ti and Ti-6Al-4V. The scale on Ti-6Al-4V also contained an α-AlO film situated between the outer and inner (TiO) layers. For both materials, multilayered-scale formation characterized air oxidation. In detail a multilayered oxide scale of TiO formed on the air-oxidized Ti, while a multilayered oxide scale with alternating layers of AlO/TiO developed on Ti-6Al-4V oxidized in air. [ABSTRACT FROM AUTHOR]

The high-temperature-corrosion behavior of a series of Fe(Ni)CrAlX-type alloys (where X=Zr and Hf, e.g.) has been studied in a gas mixture of 50% HCl-10% HO−H at 800°C. The experimental results obtained indicated that Ni-base alloys had superior corrosion resistance to Fe-base alloys in this gas mixture. While the exposed Ni-base alloys showed weight gains due to the formation of oxides (e.g., AlO, CrO) as well as CrCl, the Fe-base alloys exhibited substantial weight losses resulting from the formation and subsequent evaporation of FeCl. This study also demonstrated that Fe(Ni)Cr8AlX-type alloys, which contained high aluminum, had better chloridation resistance than Fe(Ni)25CrAlX-type alloys, which had high chromium. The improved performance of Fe(Ni)Cr8AlX-type alloys was due to the presence of a high level of aluminum which promoted formation of protective AlO. Although the presence of chromium in the alloys promoted the formation of CrO, the high level of chromium adversely affected the chloridation resistance of Fe(Ni)25CrAlX-type alloys, due to the development of chloride (CrCl) at the interface of the oxide scale and alloy substrate. [ABSTRACT FROM AUTHOR]

The sulphidation behavior of a series of MCrAlYX-type alloys, where M is Co or Co and Fe, and X is V, Nb, Mo, or W, added in combination at various levels, has been studied at 750°C in an atmosphere of $$p_{S_2 } $$ ∼ 10 Pa and $$p_{O_2 } $$ ∼10 Pa. Sulphidation kinetics followed a parabolic rate law for each alloy over prolonged periods of exposure (up to 240 hr). Inclusion of Mo in the alloy containing both V and Nb, and particularly the combined additions of Mo and W, greatly enhanced sulphidation resistance. Partial replacement of Co by Fe also provided superior sulphidation resistance. The scales formed on the Co-based alloys consisted of three subscale layers-an outer layer of CoS and CoS, a mid-layer of CrS and an inner layer of chromium and refractory-metal sulphides. In the case of (Fe, Co)-based alloys, the scales were duplex in nature with an outer layer of FeS, CoS and CrS and a compact inner layer consisting of sulphides of chromium and refractory metals. For both categories of alloys, the inner layer of refractory-metal sulphides was decorated by an alumina film which inhibited the outward migration of the base elements. [ABSTRACT FROM AUTHOR]

Bardet-Biedl syndrome (BBS) is a rare autosomal recessive multisystem involvement genetic disorder with a broad spectrum of clinical presentations. It is characterized by rod-cone dystrophy, polydactyly, obesity, learning disabilities, hypogonadism in males or genital abnormalities in females, and renal impairment. We present a case of a 12-year-old boy who complained of gradual loss of vision (particularly noticeable at night), obesity, hypogenitalism, and polydactyly. In addition, he had postaxial polydactyly in all limbs, obesity, retinitis pigmentosa, learning disabilities, hypogenitalism, speech delay, developmental delay, astigmatism, and acanthosis nigricans. Multidisciplinary approaches need to manage this disorder and need regular followup. Genetic counselling is essential. [ABSTRACT FROM AUTHOR]

A technique of suppressing passive Q-switching by inverse saturable absorption in a cw nonlinear mirror mode-locked laser is presented. The nonlinear mirror saturable absorber consists of a second-harmonic generation crystal and a dichroic mirror while the inverse saturable loss is realized by intracavity third-harmonic generation. The inverse saturation reduces significantly the critical intracavity pulse energy for stable, self-starting, self-sustained, and power scalable cw mode-locking. Two LiB3O5 crystals are employed to realize the technique in a diode array pumped Nd:YVO4 oscillator providing a peak power of 918 W, pulse width of 29 ps, and repetition rate of 170 MHz. [ABSTRACT FROM AUTHOR]

Thermal studies were performed on the segregation roasting of pure nickel sulphate. The reaction path was found to be the same as for oxide segregation, although some deviation was observed during product formation, where a metallic nugget was obtained as the end product. The nickel content in the metallic nugget has been analysed at 74% (remainder sulphur). The optimum reaction temperature appears to be 1100°C; with 10% CaCl2 + 10% charcoal addition (by weight); after roasting for 30 min, it is possible to extract a product containing 97% metallic nickel with 3% sulphur. [ABSTRACT FROM AUTHOR]

Optical power transmission changes of 10-20 dB have been experimentally demonstrated by varying the temperature of a tapered monomode optical fiber that is fixed to a glass plate by two drops of adhesive. Tile effect arises from different expansion coefficients of the glass substrate and the silica fiber This induces microbendings in the tapered region. The temperature range of the sensor may be adjusted from 2 to 100°C, depending on the taper length and width. [ABSTRACT FROM AUTHOR]