The Effect of Oxidation on the Tribological Performance of Few Vegetable Oils

BackgroundThe use of vegetable oils and their derivatives as lubricant base oils are ever increasing because of sustainability issues and in the context of conservation of nature as they are biodegradable and environmentally friendly. The one disadvantage which is of concern with vegetable oils is their limited oxidative stability.ObjectivesTo study the effect of oxidation on the tribological performance of few vegetable oils by subjecting the oil samples to accelerated ageing in a dark oven at different temperatures, inducing the oxidation under controlled conditions.MethodOils were stored at an elevated temperature in an oven under dark condition and the oxidized oil samples were analyzed in terms of various properties.Results and conclusionsThe samples were analyzed for the changes in viscosity, percentage of free fatty acid, peroxide number and were compared with fresh oils samples. Further tribological property was also evaluated and the observed differences were linked to formation of oxidation products like peroxides, kinetics of the oxidation with reference to ageing temperature

6-(4-Chloro­phen­yl)-2-isobutyl­imidazo[2,1-b][1,3,4]thia­diazole

In the title compound, C14H14ClN3S, the imidazo[2,1-b][1,3,4]thia­diazole system is essentially planar, with a maximum deviation of 0.006 (2) Å. The dihedral angle between the imidazo[2,1-b][1,3,4]thia­diazole and chloro­phenyl rings is 5.07 (8)°. In the crystal, there are no classical hydrogen bonds but stabilization is provided by weak π–π [centroid–centroid distance = 3.5697 (11) Å] and C—H⋯π inter­actions

Hesperidin Ameliorates Immobilization-Stress-Induced Behavioral and Biochemical Alterations and Mitochondrial Dysfunction in Mice by Modulating Nitrergic Pathway

The present study was aimed to evaluate the protective effect of hesperidin against immobilization-stress-induced alterations in biochemical, behavioral, and mitochondrial functions in mice. In many instances neuroscientists have reported that acute immobilization stress for 6 h resulted in anxiety and impaired locomotor activity due to excess oxidative-nitrergic stress, depletion of antioxidant defense mechanisms, and mitochondrial dysfunction in animals. In the present study, 6 h of acute immobilization stress had significantly altered the behavioral (anxiety and memory) and biochemical parameters coupled with mitochondrial dysfunction in Swiss albino mice. Fourteen days of pretreatment with Hesperidin (50 and 100 mg/kg, p.o.) significantly and dose-dependently inhibited the behavioral and biochemical alterations and mitochondrial dysfunction caused by acute immobilization stress. Furthermore, pre-treatment of l-arginine (50 mg/kg, i.p.), a nitric oxide precursor, reversed the protective effect of Hesperidin (50 and 100 mg/kg) (P < 0.05). In contrast, pretreatment of l-NAME (5 mg/kg, i.p.), a nitric oxide synthase inhibitor, potentiated the protective effect of Hesperidin (P < 0.05). These results suggest the possible involvement of nitrergic pathway in the protective effect Hesperidin against immobilization-stress-induced behavioral, biochemical, and mitochondrial dysfunction in mice

DEVELOPMENT AND VALIDATION OF SEVEN PHENYL HYDRAZINE CHLORO ESTER ISOMERS (PGIs) BY RP-HPLC-UV METHOD IN ANTICOAGULANT DRUG SUBSTANCE; APIXABAN

Objective: The objective of this work was to develop and validate a simple and sensitive reverse-phase high-pressure liquid chromatography method for the determination of seven potential genotoxic impurities in Apixaban drug substance. Methods: The optimized separation was achieved by using ACE 3 C18 PFP (150 mm×4.6 mm, 3 µm) HPLC column. The mobile phase-A was a degassed mixture of 0.01M Ammonium acetate buffer(PH adjusted 4.9±0.05 with diluted glacial acetic acid) and mobile phase-B was a degassed mixture of Acetonitrile, Isopropyl alcohol and Buffer PH 4.9 in the ratio of 60:20:20 v/v/v. The gradient program was operated at a flow rate of 1.0 ml/min and UV detection was at 330 nm. Results: The method was superior at linearity for seven impurities and correlation coefficient values were larger than 0.999, moreover, in the separation point of view, this method further achieved no matrix interference through chromatography by better resolution of the other impurities from the Apixaban drug substance and its related impurities for the accurate analysis of seven potential genotoxic impurities. The established limits of detection (LOD), limits of quantification (LOQ) values for the seven mutagenic impurities were each of 5 ppm (0.015µg/ml) and15 ppm (0.045µg/ml) respectively. The developed method was validated as per ICH guidelines and applied as a generic method to determine these seven potential genotoxic impurities for the pharmaceutical process control and drug material release. Conclusion: Validation of this analytical method was carried out including stability, selectivity, linearity, accuracy, system precision, method precision and intermediate precision thus proving that the described RP-HPLC method could be employed for fast and simple analysis of sevenphenyl hydrazine chloro ester isomers in Apixaban drug substance

BER Analysis of Full Duplex Relay assisted BPSK-SIM based VLC System for Indoor Applications

This paper contemplates a relay-assisted visible light communication (VLC) system, where the light source (Table lamp) acts as a relay node and cooperates with the main light source. Following the IEEE 802.15.7r1 VLC reference channel model, we assume that there are two different light sources present in an office room. The first one is the source terminal present on the ceiling and another one is the desk lamp that serves as the relay station which works in full-duplex method. Because of the loop interference channel, we model VLC relay terminal using ray tracing simulations. We have analyzed bit error rate (BER) performance of the relay-assisted VLC system using binary phase shift keying-subcarrier intensity modulation (BPSK-SIM) technique. The proposed method outperforms existing phase shift keying (PSK) and square M-quadrature amplitude modulation (M-QAM) techniques. The proposed VLC system using BPSK-SIM technique achieves a BER performance of for an SNR of 20 dB. The results of proposed full duplex and half duplex relayed VLC system are evaluated using equal power allocation (EPA) and optimum power allocations (OPA) techniques over three different modulation schemes which are 2-PSK, square M-QAM, BPSK-SIM

Mammogram Based Automatic Computer Aided Detection Of Masses In Medical Images

Breast cancer was a treacherous disease, which leads to large scale of death for women. Substantial numbers of patients are reaching to a progressive breast cancer stage due to increase in the false negatives coming out of cumbersome and tedious job of continuously observing the mammograms in fatigue. Mammogram is a scanning image of breast, used to aid in the early detection as well as diagnosis of breast diseases. Because of high sensitivity, mammogram will lose precision of an image. To overcome this issue, the Automatic Mass Detection of Mammogram was developed based on the Computer Aided Detection (CAD) techniques for the correct identification of cancer in the breast and it gives 80-90% of high detection rate. This technique will guide radiologist to determine the presence of cancer accurately. The proposed Independent Component Analysis will involve local and texture feature for mass detection. The two complex features are extracted, based upon the co-occurrence matrix and optical density transformation to describe local texture characteristic. The proposed method uses Independent Component Analysis for selecting normal and abnormal area of individual region, which will give more accuracy. Finally, compared to LDA the obtained successive rate of accuracy in ICA method is  93.82

Preparation, Characterization and In Vitro Drug Release Studies of 6-mercaptopurine Thin Film

Oral thin films of 6-mercaptopurine were fabricated from mucoadhesive polymer, chitosan and polyvinylpyrrolidone for the purpose of prolonging drug release and improving its bioavailability. All fabricated film formulations prepared were smooth and translucent, with good flexibility. The weight and thickness of all the formulations were found to be uniform. These films were also evaluated for surface pH, folding endurance, swelling percentage (% S) and in vitro disintegration time. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) were used to evaluate the physico-chemical nature of the films. In-vitro drug release have shown enhanced release profiles for thin films compared to pure drug and the release patterns have been found to be pH dependant. The results of the study reveals that fabrication of 6-MP oral thin film by using solvent cast technology is a simple and an efficient method for drug delivery to achieve desired therapeutic compliance.Keywords: 6-mercaptopurine; In Vitro Drug Release; SEM; FTI

Interface-engineered templates for molecular spin memory devices

The use of molecular spin state as a quantum of information for storage, sensing and computing has generated considerable interest in the context of next-generation data storage and communication devices(1, 2), opening avenues for developing multifunctional molecular spintronics(3). Such ideas have been researched extensively, using single-molecule magnets(4, 5) and molecules with a metal ion(6) or nitrogen vacancy(7) as localized spin-carrying centres for storage and for realizing logic operations(8). However, the electronic coupling between the spin centres of these molecules is rather weak, which makes construction of quantum memory registers a challenging task(9). In this regard, delocalized carbon-based radical species with unpaired spin, such as phenalenyl(10), have shown promise. These phenalenyl moieties, which can be regarded as graphene fragments, are formed by the fusion of three benzene rings and belong to the class of open-shell systems. The spin structure of these molecules responds to external stimuli(11, 12) (such as light, and electric and magnetic fields), which provides novel schemes for performing spin memory and logic operations. Here we construct a molecular device using such molecules as templates to engineer interfacial spin transfer resulting from hybridization and magnetic exchange interaction with the surface of a ferromagnet ; the device shows an unexpected interfacial magnetoresistance of more than 20 per cent near room temperature. Moreover, we successfully demonstrate the formation of a nanoscale magnetic molecule with a well-defined magnetic hysteresis on ferromagnetic surfaces. Owing to strong magnetic coupling with the ferromagnet, such independent switching of an adsorbed magnetic molecule has been unsuccessful with single-molecule magnets(13). Our findings suggest the use of chemically amenable phenalenyl-based molecules as a viable and scalable platform for building molecular-scale quantum spin memory and processors for technological development

Application of 57Fe Mössbauer spectroscopy as a tool for mining exploration of bornite (Cu5FeS4) copper ore

Nuclear resonance methods, including Mössbauer spectroscopy, are considered as unique techniques suitable for remote on-line mineralogical analysis. The employment of these methods provides potentially significant commercial benefits for mining industry. As applied to copper sulfide ores, Mössbauer spectroscopy method is suitable for the analysis noted. Bornite (formally Cu5FeS4) is a significant part of copper ore and identification of its properties is important for economic exploitation of commercial copper ore deposits. A series of natural bornite samples was studied by 57Fe Mössbauer spectroscopy. Two aspects were considered: reexamination of 57Fe Mössbauer properties of natural bornite samples and their stability irrespective of origin and potential use of miniaturized Mössbauer spectrometers MIMOS II for in-situ bornite identification. The results obtained show a number of potential benefits of introducing the available portative Mössbauer equipment into the mining industry for express mineralogical analysis. In addition, results of some preliminary 63,65Cu nuclear quadrupole resonance (NQR) studies of bornite are reported and their merits with Mössbauer techniques for bornite detection discussed