Biobased flexible polyurethane foams manufactured from lactide-based polyester-ether polyols for automotive applications

In this study, biobased polyester-ether polyols derived from meso-lactide and dimer acids were evaluated for flexible polyurethane foams (PUF) applications. Initially, the catalyst concentration was optimized for the biobased PUF containing 30% of biobased polyol (70% petroleum-based polyol). Then, the same formulation was used for biobased PUF synthesis containing 10%–40% of biobased polyols. The performance of biobased PUF was compared with the performance of the control foam made with 100% petroleum-based polyol. The characteristic times (cream, top of the cup, string gel, rise, tack-free) of biobased PUF were determined. The biobased PUF were evaluated for the mechanical (tensile and compressive) and morphological properties. As the wet compression set is important for automotive applications, it was measured for all biobased PUF. The thermal degradation behavior of biobased PUF was also evaluated and compared with the control foam. The effect of different hydroxyl and acid values of polyols on the mechanical properties of biobased PUF is also discussed. The miscibility of all components of PUF formulations is crucial in order to produce a foam with uniform properties. Thus, the miscibility of biobased polyols with commercial petroleum-based polyol was studied.     

Corrosion performance of high pressure die-cast Al-6Si-3Ni and Al-6Si-3Ni-2Cu alloys in aqueous NaCl solution

The corrosion performance of high pressure die-cast Al-6Si-3Ni (SN63) and Al-6Si-3Ni-2Cu (SNC632) alloys in 3.5% (mass fraction) NaCl solution was investigated. X-ray diffraction (XRD) and microstructural studies revealed the presence of single phase Si and binary Al₃Ni/Al₃Ni₂ phases along the grain boundary. Besides, the single Cu phase was also identified at the grain boundaries of the SNC632 alloy. Electrochemical corrosion results revealed that, the SNC632 alloy exhibited nobler shift in corrosion potential (?_corr), lower corrosion current density (J_corr) and higher corrosion resistance compared to the SN63 alloy. Equivalent circuit curve fitting analysis of electrochemical impedance spectroscopy (EIS) results revealed the existence of two interfaces between the electrolyte and substrate. The surface layer and charge transfer resistance (R_ct) of the SNC632 alloy was higher than that of the SN63 alloy. Immersion corrosion test results also confirmed the lower corrosion rate of the SNC632 alloy and substantiated the electrochemical corrosion results. Cu addition improved the corrosion resistance, which was mainly attributed to the absence of secondary Cu containing intermetallic phases in the SNC632 alloy and Cu presented as single phase.     

Screening of β1- and β2-Adrenergic Receptor Modulators through Advanced Pharmacoinformatics and Machine Learning Approaches

Cardiovascular diseases (CDs) are a major concern in the human race and one of the leading causes of death worldwide. β-Adrenergic receptors (β1-AR and β2-AR) play a crucial role in the overall regulation of cardiac function. In the present study, structure-based virtual screening, machine learning (ML), and a ligand-based similarity search were conducted for the PubChem database against both β1- and β2-AR. Initially, all docked molecules were screened using the threshold binding energy value. Molecules with a better binding affinity were further used for segregation as active and inactive through ML. The pharmacokinetic assessment was carried out on molecules retained in the above step. Further, similarity searching of the ChEMBL and DrugBank databases was performed. From detailed analysis of the above data, four compounds for each of β1- and β2-AR were found to be promising in nature. A number of critical ligand-binding amino acids formed potential hydrogen bonds and hydrophobic interactions. Finally, a molecular dynamics (MD) simulation study of each molecule bound with the respective target was performed. A number of parameters obtained from the MD simulation trajectories were calculated and substantiated the stability between the protein-ligand complex. Hence, it can be postulated that the final molecules might be crucial for CDs subjected to experimental validation.     

<Emphasis Type=Bold>Analysis of Spatio-temporal Characteristics and Regional Frequency of Droughts in the Southern Peninsula of India</Emphasis>

A detailed regional drought study is carried out in the southern peninsula of India to characterize the spatio-temporal nature of droughts and to predict the drought magnitudes for various probabilities in the homogeneous drought regions. The method of several random initializations of the cluster centres of the K-means algorithm is suggested for the identification of the initial regions in the context of drought regionalization, which is shown to perform better than the initialization from the Ward’s algorithm and the Ward’s algorithm itself. The peninsula is classified into seven spatially well-separated homogeneous drought regions. The robust L-moment framework is used for the regional frequency analysis of drought magnitudes computed using the standardized precipitation index. The Pearson type III is found to be appropriate for regional drought frequency analysis in six of the regions, while the robust Wakeby distribution is suggested for one region. Low magnitude droughts are frequent and dominant in the northern part of west coast, the north-eastern coast and its adjoining inland region, while high magnitude droughts are less in number and are experienced in semi-arid central part, southern part of western coast, south-eastern part and north-western inland region. The spatial maps of drought magnitudes indicate that at higher return periods (100 and 200 years) the south-eastern part of the peninsula is likely to encounter high magnitude droughts, while the central region is likely to experience the same at lower return periods (10 and 50 years). Hence these regions need to be given special importance in the drought mitigation planning activities.     

Effect of cumin, cinnamon, ginger, mustard and tamarind in induced hypercholesterolemic rats.

The effect of a few common spices--cumin (Cuminum cyminum, cinnamon (Cinnamomum zeylanicum), ginger (Zingiber officinale), mustard (Brassica nigra) and tamarind (Tamarindus indica)--added to normal and hypercholesterolemia inducing diet on serum and liver cholesterol levels in rats was studied. These spices did not show any cholesterol lowering effect when included in the diet at about 5-fold the normal human intake level.     

Large Eddy Simulation of Turbulent Slot Jet Impingement Heat Transfer at Small Nozzle-to-Plate Spacing

We present fluid flow and heat transfer of a slot jet impingement heat transfer at a small value of the nozzle-to-plate spacing at which a secondary peak in the Nusselt number is observed. Large eddy simulation has been performed with a finite-volume-based computational fluid dynamics code and using a dynamic Smagorinsky model. The optimum domain size and grid for large eddy simulation (LES) have been produced based on LES computations on a coarse mesh and Reynolds-averaged Navier–Stokes-based computations. Two inflow conditions, namely, using the vortex method and no perturbations, were compared. The present LES results, using the vortex method, capture the secondary peak in the Nusselt number better as compared to the case with no perturbations. Results show that mean velocity profile in the stagnation region deviates from the standard law of the wall. Further, large-scale vortical structures were observed near the location of the secondary Nusselt number peak. Increases in both the streamwise and wall normal turbulence fluctuations are observed near the secondary peak in the Nusselt number. The secondary peak in Nusselt number is found to be associated with the combined effect of flow acceleration and an increase in the turbulence kinetic energy.     

澳大利亚水资源管理及水权制度建设的经验与启示

根据赴澳大利亚水资源的现状、管理体制的考察和学习,总结澳洲水资源管理和水权制度建设的经验,针对目前江西水权制度建设工作提出建议。     

Influence of dietary spices and their active principles on pancreatic digestive enzymes in albino rats

A few common spices or their active principles were examined for their possible influence on digestive enzymes of pancreas in experimental rat. Groups of animals were maintained for 8 weeks on the following spice diets: curcumin (0.5%), capsaicin (15 mg%), piperine (20 mg%), ginger (50 mg%), cumin (1.25%), fenugreek (2%), mustard (250 mg%) and asafoetida (250 mg%). Dietary curcumin, capsaicin, piperine, ginger, fenugreek and asafoetida prominently enhanced pancreatic lipase activity. Curcumin, capsaicin, piperine, ginger, cumin and asafoetida also stimulated pancreatic amylase. Trypsin was significantly stimulated by curcumin, capsaicin, piperine, ginger and cumin, while chymotrypsin was stimulated by all the spices tested except mustard. This stimulatory influence of test spices on the pancreatic digestive enzymes was however not observed when their intake was restricted to a single oral dose. The positive influences on the pancreatic digestive enzymes exerted by a good number of spices consumed in diet could be a factor contributing to the well recognised digestive stimulant action of spices.     

Development and Integration of Sub-hourly Rainfall–Runoff Modeling Capability Within a Watershed Model

Increasing urbanization changes runoff patterns to be flashy and instantaneous with decreased base flow. A model with the ability to simulate sub-daily rainfall–runoff processes and continuous simulation capability is required to realistically capture the long-term flow and water quality trends in watersheds that are experiencing urbanization. Soil and Water Assessment Tool (SWAT) has been widely used in hydrologic and nonpoint sources modeling. However, its subdaily modeling capability is limited to hourly flow simulation. This paper presents the development and testing of a sub-hourly rainfall–runoff model in SWAT. SWAT algorithms for infiltration, surface runoff, flow routing, impoundments, and lagging of surface runoff have been modified to allow flow simulations with a sub-hourly time interval as small as one minute. Evapotranspiration, soil water contents, base flow, and lateral flow are estimated on a daily basis and distributed equally for each time step. The sub-hourly routines were tested on a 1.9 km² watershed (70% undeveloped) near Lost Creek in Austin Texas USA. Sensitivity analysis shows that channel flow parameters are more sensitive in sub-hourly simulations (Δt = 15 min) while base flow parameters are more important in daily simulations (Δt = 1 day). A case study shows that the sub-hourly SWAT model reasonably reproduces stream flow hydrograph under multiple storm events. Calibrated stream flow for 1 year period with 15 min simulation (R ² = 0.93) shows better performance compared to daily simulation for the same period (R ² = 0.72). A statistical analysis shows that the improvement in the model performance with sub-hourly time interval is mostly due to the improvement in predicting high flows. The sub-hourly version of SWAT is a promising tool for hydrology and non-point source pollution assessment studies, although more development on water quality modeling is still needed.     

Fast estimation of outage probabilities in MIMO channels

Fast estimation methods for small outage probabilities of signaling in fading multiple-input multiple-output (MIMO) channels are developed. Communication over such channels is of much current interest, and quick and accurate methods for estimating outage capacities are needed. The methods described herein use adaptive importance sampling (IS) techniques as developed in a series of recent publications. Fast algorithms are provided for evaluating "nonergodic" capacities of Rayleigh fading MIMO channels. The methodology can be extended to more general models. Numerical results on outage capacity are provided, and these extend and complement known results in the literature.