Multi-technique observations on precipitation and other related phenomena during cyclone Aila at a tropical location

A severe cyclone, named Aila, passed over Kolkata on 25 May 2009. The strong convective activities manifested through rainfall during the cyclone were studied with multi-technique observations involving micro rain radar, disdrometer, rain gauges, and a Ku-band satellite signal receiving system. A number of features of precipitation, namely the presence of large rain drops, the large vertical extent of the precipitating layer, an unusual enhancement of cross-polar component, and strong scintillations of the co-polar component of the satellite signal due to strong turbulences associated with the cyclone, were observed. This study leads to a more comprehensive understanding of the precipitation associated with a cyclonic storm.     

Structural Deterioration Assessment for Steel Bridges

A rational approach for evaluating structural integrity of aged and deteriorated steel bridges—incorporating analytical, mechanical, and microstructural characterizations—is presented. Critical regions of built-up members, salvaged from decommissioned truss bridges, were identified using structural finite element analysis and the results guided the sampling process for microstructural analysis. A set of mechanical and metallurgical characterization procedures were designed to understand the mechanical history of critical sections of the structure. Observations made on the microstructure of a naturally stressed region revealed segregation of pearlite and MnS inclusions and flow of grains. The mechanical flow and microcracks observed in the stress-concentrated tensile region of the member indicate a high probability of eventual brittle failure of the material. Since stress-assisted aging seems to affect the microstructure, this may be used as a means of unobtrusive testing for susceptibility to failure. It follows that the microstructural analysis procedure, to detect stress-assisted aging and failure, may serve as a novel field-evaluation technique for aged steel structures.     

Use of a Moist Granulation Technique (MGT) to Develop Controlled-Release Dosage Forms of Acetaminophen

The moist granulation technique (MGT), which involves agglomeration and moisture absorption, has only been applied to immediate-release dosage forms. Our results indicate that MGT appears to be applicable in developing a controlled-release formulation. A small amount of granulating fluid (water) was added to a powder blend to activate a dry binder (such as polyvinylpyrrolidone [PVP] at 2% and 3.6%) and to facilitate agglomeration. Then, a moisture-absorbing material (microcrystalline cellulose [MCC]) was added to absorb any excess moisture. By adding MCC in this way, a drying step was not necessary. Acetaminophen (APAP) was the model drug, with diluents lactose FastFlo® and dicalcium phosphate. Hydroxypropylcellulose (HPC) was used as the controlled-release agent. The MGT was compared to conventional wet granulation (WG) and direct compression (DC) processing methods. The results indicate that MGT appears to be applicable in developing a controlled-release formulation. Particle size distribution of MGT and WG batches containing 3.6% PVP is similar.     

Cardiac manifestations of polymyositis. Apropos of 2 Senegalese cases]

The relaxations mediated by the activation of 5-HT receptors in the guinea pig proximal colon were investigated. Longitudinal strips were cut from the colon segment and placed into the bath. In the presence of atropine (0.2 microM), the relaxations were evoked by adding increasing concentrations of 5-HT (1-100 microM). Noncumulative concentration-response curves were established in the absence and presence of either 5-HT or nitric oxide synthase (NOS) antagonists. Selective 5-HT3 antagonists tropisetron (10 and 100 nM) and ondansetron (1 microM) inhibited the relaxations and shifted the concentration-response curves to the right. Similar effects were observed in the presence of the NOS inhibitor N(G)-nitro-L-arginine (3.2, 10, 32 microM) and partly reversed with L-arginine (100, 320 microM). N(G)-nitro-D-arginine, serving as a negative control, was ineffective. The relaxations were further inhibited in the presence of the soluble guanylate cyclase blocker methylene blue (10 microM) or NO scavenger hemoglobin (32 microM). These results suggest that the 5-HT3 receptor plays a role in neurogenic relaxations of guinea pig proximal colon, which are at least partly mediated via release of NO from nerve endings.     

Numerical prediction of undrained cyclic triaxial experiments on saturated Kasai river sand using two constitutive models of liquefaction

Bulletin of Engineering Geology and the Environment - The paper presents a numerical simulation of stress-controlled undrained cyclic tri-axial tests conducted on local sand at various relative...     

Combined effects of natural substances and modified atmosphere packaging on reducing enzymatic browning and postharvest decay of longan fruit

An integrated control strategy on preventing pericarp browning (BI) and decay incidence (DI) of longan fruit was investigated to replace sulphur dioxide (SO₂) fumigation. Fruit was treated with 5% ascorbic acid (AA), citric acid (CA), oxalic acid (OA), thymol (TH) and 2% chitosan (CH) for 5 min; sealed under modified atmosphere packaging (MAP) using high permeable film; and stored at 5 °C. Fruit treated with distilled water and sealed under MAP condition (MAPC) and air condition (AIRC) was used as controls. Combined effects of chemical treatments and MAP maintained quality of longan for 56 and 49 days in CH and TH, respectively, as compared to 28 days in MAPC and 21 days in AIRC. AA, CA and OA prevented BI, restrained enzyme activities and maintained high phenols. AA, CA and OA were most potent BI inhibitors; however, DI was the limitation of these treatments, while CH and TH effectively inhibited DI.     

Prediction of temperature in secondary steelmaking: mathematical modelling of fluid flow and heat transfer in gas purged ladle

As a first step towards prediction of temperatures in secondary steelmaking, mathematical modelling of fluid flow and heat transfer in ladle furnace was undertaken. A two‐dimensional quasi‐single phase model has been developed for turbulent recirculating flow by solving Reynolds averaged Navier‐Stokes equations along with a two‐equation k‐? model. The model was then extended to include thermal transport in a conjugate domain (i.e., molten steel + refractory shell + steel shell). The flow model was validated with water model data reported in literature by different researchers. Good agreement for velocity field and satisfactory agreement for turbulent kinetic energy field were obtained. The thermal model showed good agreement with results predicted in literature. The paper also presents findings of tests for sensitivity of flow on modelling and process parameters. By comparison with water model experiments, it has been demonstrated that the flow field in a ladle with a porous plug can be represented using a gas voidage fraction in the plume obtained from experiments with nozzles for axial gas injection from the bottom. Flow and thermal fields were insensitive to initial turbulence level at nozzle. Maximum temperature inhomogeneity in the melt was 2 °C after 1.5 min and negligible after 3 min of onset of gas purging.     

State-of-the-Art Report on Optimizing Particle Advection Performance

The computational work to perform particle advection-based flow visualization techniques varies based on many factors, including number of particles, duration, and mesh type. In many cases, the total work is significant, and total execution time (“performance”) is a critical issue. This state-of-the-art report considers existing optimizations for particle advection, using two high-level categories: algorithmic optimizations and hardware efficiency. The sub-categories for algorithmic optimizations include solvers, cell locators, I/O efficiency, and precomputation, while the sub-categories for hardware efficiency all involve parallelism: shared-memory, distributed-memory, and hybrid. Finally, this STAR concludes by identifying current gaps in our understanding of particle advection performance and its optimizations.     

Core Fluorination Enhances Solubility and Ambient Stability of an IDT‐Based n‐Type Semiconductor in Transistor Devices

The synthesis of a novel fluorinated n‐type small molecule based on an indacenodithiophene core is reported. Fluorination is found to have a significant impact on the physical properties, including a surprisingly dramatic improvement in solubility, in addition to effectively stabilizing the lowest‐unoccupied molecular orbital energy (?4.24 eV). Single‐crystal analysis and density functional theory calculations indicate the improved solubility can be attributed to backbone torsion resulting from the positioning of the fluorine group in close proximity to the strongly electron‐withdrawing dicyanomethylene group. Organic thin‐film transistors made via blade coating display high electron mobility (up to 0.49 cm² V^?1 s^?1) along with good retention of performance in ambient conditions.     

Phenomenal Effect of Stable (Ti,Mo)C Nano-Sized Precipitates in Retarding the Recrystallization and Grain Growth in High-Strength Ferritic Steel

Metallurgical and Materials Transactions A - The present study demonstrates remarkable retardation of recrystallization and grain growth during sub-critical annealing of 60 pct cold-rolled ferritic...