Synthesis, optical and morphological characterization of soluble main chain 1,3,4-oxadiazole copolyarylethers—potential candidates for solar cells applications as electron acceptors

New copoly(arylether)s containing substituted terphenyl, quinquephenyl, fluorene and anthracene moieties with aromatic 1,3,4-oxadiazole units were prepared and the resulting copolymers are soluble in common organic solvents. Investigation of their optical properties revealed that they emit blue and yellow light. Moreover, their photovoltaic response was studied in blends with poly(3-hexylthiophene) (P3HT) as the electron donor. Despite the low power conversion efficiencies it was shown that photo-induced electron transfer does take place and the performances are higher than a single layer P3HT device. In addition, an anthracene-fluorene-oxadiazole main chain copolymer (PAFOXD) was also examined in a single layer photovoltaic device and gave one of the highest reported open-circuit voltage (V_oc) values in the literature (0.89 V). Finally, a detailed morphological study of the blends and the PAFOXD surface using the atomic force microscopy (AFM) technique, revealed the effect of solvent selection to the preparation of thin films exhibiting the desired performance characteristics.     

Cytochrome P450 inhibitory potential of selected Indian spices — possible food drug interaction

Spices constitute an important group of food which is virtually indispensable in the culinary art. In a view, these spices feared to pose a probability to affect the disposition of conventional pharmaceuticals through inhibition of human cytochrome P450 (CYPs) enzymes. In the present study an approach has been made to evaluate the possible CYP inhibition potential with some Indian spices (Capsicum annuum, Murraya koenigii, Zingiber officinale) and their major bioactive compounds, in combination with pooled microsome; as well as commercially available recombinant human CYP3A4, CYP2D6, CYP2C9 and CYP1A2. Quantification of the bioactive compound was determined through RP-HPLC, in order to standardize the plant material. CYP–carbon monoxide (CYP–CO) complex assay result indicated that all the plants and their bioactive compounds have an interaction potential with CYPs. Fluoregenic assay results indicated that the spice extracts have higher inhibition potential comparing to their single bioactive molecule. The higher enzyme inhibition potential by the extracts may be related to the synergistic effects due to the presence of other constituents in the extract. Capsaicin and C. annuum showed the lowest IC₅₀ value and 6-gingerol and Z. officinale extract showed the highest IC₅₀ value among the entire sample tested. The entire sample showed significantly less (P < 0.001, P < 0.01) interaction potential than known inhibitors. These findings indicate that selected spices are unlikely to cause clinically relevant drug interactions involving the inhibition of major CYP isozymes.     

Cold Simulation of Metalloids Transport in Blast Furnaces

Metalloids normally get transferred at the interface of metal droplets passing through the slag system in the dropping zone and at the slag‐metal interface in the hearth zone in the lower region of a blast furnace. In these high temperature processes, the mass transport being the rate‐controlling factor, the viscosity of the slag system determines the kinetics of the refining reactions accompanied by mass and heat transfer at the metal droplets and slag interface. Slag systems generally possess random network structures comprising internal regions of weak ordering. The presence of these regions may result in non‐Newtonian behaviour of the slag. The rheological characteristics of a fluid relating to its network structure is expressed in terms of the indices consistency (k') and flow behaviour (n'). The extent of metalloids presence in hot metal is subjected to their residence time at the slag‐metal interface. The metal droplet descent through a surrounding fluid system has been studied and a co‐relation between drag Reynolds number and modified Reynolds number has been obtained. This correlation has been used to determine the drag velocity of a metal droplet falling through a slag system and the residence time distribution (RTD) of the metalloids at the slag‐metal interface in the lower region of the blast furnace.     

Hydration and strength development of cements produced from raw mixes containing MoO3, Nb2O5, WO3 and ZrO2

The purpose of this paper is to investigate the effects of MoO₃, Nb₂O₅, WO₃ and ZrO₂ on the hydration process and on the mechanical properties of cement. The above oxides were added separately to cement raw mixes and their influence on hydration of derived cements was studied by means of thermal analysis and X-Ray diffraction. Additionally, compressive strength and setting time were measured.     

Continuous User Authentication System: A Risk Analysis Based Approach

With the expansion of smart device users, the security mechanism of these devices in terms of user authentication has been advanced a lot. These mechanisms consist of a pattern based authentication, biometric based authentication, etc. For security purpose whenever a user fails to authenticate themselves, these devices get locked. But as these devices consist of numerous applications (document creator, pdf viewer, e-banking, Social networking app, etc.), locking of the whole devices prevents the user from using any of the applications. Since the variety of applications provided by the devices have different security needs, we feel it is better to have application level security rather than device level. Here, in this paper, we have proposed a behavioral biometric based user authentication mechanism for application level security. First, we have performed a risk assessment of different applications. Then for complete protection, static multi-modal (keystroke and mouse dynamics) authentication at the start of an interactive session, and a continuous keystroke authentication during this session is performed. An analysis of the proposed authentication mechanism has been conducted on the basis of false acceptance rate (FAR), false rejection rate (FRR) and equal error rate (EER). The static multi-modal authentication achieved a FAR of 0.89%, FRR of 1.2% and EER of 1.04% using J48 classification algorithm. Whereas the continuous keystroke authentication has been analyzed by the time (no. of keystrokes pressed) taken to capture an intruder.

     

Dissolution of aluminosilicate minerals and by-products in alkaline media

In this work, the leaching behaviour of six aluminosilicate industrial minerals and by-products (kaolin, metakaolin, fly ash, natural pozzolana from Milos, zeolite and furnace slag) in alkaline solutions is investigated. The variables studied are the kind of alkali metal (K, Na), the concentration of the alkaline solution (2.5, 5 and 10 M) and the time of dissolution (5, 10 and 24 h). The solid residue after the leaching was examined by means of XRD and FTIR. As it is concluded, the leaching ability of Al and Si is according to the following descending order: Metakaolin > Zeolite > Slag > Fly Ash > Pozzolana > Kaolin. The extent of dissolution is higher in NaOH than in KOH solutions, especially when the most reactive materials are concerned. Finally, Si and Al seem to have a synchronized leaching behaviour in both alkaline solutions.     

A QCA design and energy analysis of binary semaphore with a comprehensive case study

Innovations in Systems and Software Engineering - Quantum dot cellular automata appeared as a comprehensive solution to the shortfalls CMOS technology is facing in case of nanoscale...     

Enhancing bioavailability and hepatoprotective activity of andrographolide from Andrographis paniculata,a well‐known medicinal food,through its herbosome

BACKGROUND: Andrographis paniculata is a health food used extensively in Southeast Asia, India and China and contains the pharmacologically important phytochemical andrographolide. Although andrographolide has antihepatotoxic activity, its bioavailability from A. paniculata is restricted by its rapid clearance and high plasma protein binding. The aim of this study was to formulate a herbosome of andrographolide with a naturally occurring phospholipid in order to enhance the bioavailability and hepatoprotective activity of andrographolide in rats. RESULTS: Andrographolide herbosome equivalent to 25 and 50 mg kg⁻¹ andrographolide significantly protected the liver of rats, restoring hepatic enzyme activities with respect to carbon tetrachloride‐treated animals (P < 0.05 and P < 0.01 respectively). The rat plasma concentration of andrographolide obtained from the complex equivalent to 25 mg kg⁻¹ andrographolide (C_max = 9.64 µg mL⁻¹) was higher than that obtained from 25 mg kg⁻¹ andrographolide (C_max = 6.79 µg mL⁻¹), and the complex maintained its effective plasma concentration for a longer period of time. CONCLUSION: The results proved that the andrographolide complex produced by this method has better bioavailability and hence improved hepatoprotective activity compared with andrographolide at the same dose. Andrographolide complexation is therefore helpful in solving the problem of rapid clearance and low elimination half‐life associated with andrographolide from A. paniculata. Copyright © 2009 Society of Chemical Industry     

On-board Vehicle Data Stream Monitoring Using MineFleet and Fast Resource Constrained Monitoring of Correlation Matrices

This paper considers the problem of monitoring vehicle data streams in a resource-constrained environment. It particularly focuses on a monitoring task that requires frequent computation of correlation matrices using lightweight on-board computing devices. It motivates this problem in the context of the MineFleet Real-Time system and offers a randomized algorithm for fast monitoring of correlation (FMC), inner product, and Euclidean distance matrices among others. Unlike the existing approaches that compute all the entries of these matrices from a data set, the proposed technique works using a divide-and-conquer approach. This paper presents a probabilistic test for quickly detecting whether or not a subset of coefficients contains a significant one with a magnitude greater than a user given threshold. This test is used for quickly identifying the portions of the space that contain significant coefficients. The proposed algorithm is particularly suitable for monitoring correlation and related matrices computed from continuous data streams.     

Preparation and characterisation of protein hydrolysates from Indian defatted rice bran meal

Rice bran meal is a very good source of protein along with other micronutrients. Rice bran meal has been utilized to produce protein isolates and respective protein hydrolysates for potential application in various food products. De-oiled rice bran meal, available from Indian rice bran oil extraction plants, was initially screened by passing through an 80-mesh sieve (yield about 70%). A fraction (yield-30%) rich in fibre and silica was initially discarded from the meal. The protein content of the through fraction increased from 20.8% to 24.1% whereas silica content reduced from 3.1% to 0.4%. Rice bran protein isolate (RPI) was prepared by alkaline extraction followed by acidic precipitation at isoelectric point. This protein isolate was hydrolysed by papain at pH 8.0 and at 37 degrees C for 10, 20, 30, 45 and 60 minutes. The peptides produced by partial hydrolysis had been evaluated by determining protein solubility, emulsion activity index (EAI), emulsion stability index (ESI), foam capacity and foam stability (FS). All protein hydrolysates showed better functional properties than the original protein isolate. These improved functional properties of rice bran protein hydrolysates would make it useful for various application especially in food, pharmaceutical and related industries.