Storage Life of an Aluminised HE Composition .

Most high explosive compositions are organic in nature and they tend to undergo slow decomposition during storage under different environmental conditions. The decomposition degrade the molecular stability of the explosive, thereby resulting in reduced performance and service life. The knowledge of decomposition behaviour of the explosive mass determines the storage life of the composition. Hence, change in the chemical stability, sensitivity, mechanical strength and performance are of utmost importance in the prediction of storage life of explosive/ammunitions systems. This paper presents the results on the rate of gas evolution, change in sensitivity, and thermal stability and weight loss of high explosive compositions, viz., Dentex and TNT when exposed to elevated temperature. Based on the collected data, a tentative storage life for the aluminised (Dentex) composition has been computed to be 15 years. The data has been compared with TNT, a standard explosive for assessing the storage life

Engineering the microbiota to treat metabolic disorders

Inborn errors of metabolism (IEM) are a family of more than 500 potentially lethal congenital genetic disorders that cumulatively affect 1 in 1000 newborns. In many IEMs, pathologies manifest as a result of improper metabolism of nutrients in food. In Phenylketonuria (PKU) for example, elevated levels of phenylalanine and the accumulation of aberrant metabolic intermediates in the system lead to acute and chronic toxicities. Resultantly, many disorders within this group are generally treated through lifelong nutritional management due to the lack of alternative and pharmacological options. Longitudinal studies have indicated that even with strict adherence to a diet of synthetic supplements, patients experience chronic issues like frailty, delayed growth, and intellectual disabilities. Recently, enzyme-replacement therapies (ERT) have demonstrated promise in pre-clinical and clinical settings by providing a metabolic sink for phenylalanine in PKU. As an enhancement to traditional ERT, we are developing a novel therapeutic for IEMs associated with amino acids by expressing metabolic enzymes in lactic acid bacteria (LAB) that natively colonize the human gastrointestinal (GI) tract. Starting with an enzyme under clinical development for PKU, phenylalanine ammonia-lyase (PAL), and by promoting the intestinal adhesion and colonization characteristics, the engineered LAB will intervene before amino acid absorption occurs in the small intestines during digestion. To engineer new enzymes with activities required for treating IEMs, we have developed a novel facile selection and screening methodology. This can potentially be utilized to enhance enzymatic properties or identify mutants with altered substrate specificity, creating a spectrum of PALs that can be used to treat IEMs associated with other amino acids. Here we describe the methodology, development, and optimization of this method. To characterize and engineer microbial adhesion to intestinal mucus, we developed a novel assay that is able to capture the quantitative and mechanistic binding thermodynamics of cells to mucus. We will discuss the development of this assay and its implementation for engineering improved mucus binding. The platform technologies discussed here will be instrumental in realizing microbiota-based therapeutics as an emerging and urgently-needed treatment for IEMs that currently have inadequate or no options

Evaluation of the Anxiolytic Activity of NR-ANX-C (a Polyherbal Formulation) in Ethanol Withdrawal-Induced Anxiety Behavior in Rats

The present study investigates the anxiolytic activity of NR-ANX-C, a standardized polyherbal formulation containing the extracts of Withania somnifera, Ocimum sanctum, Camellia sinensis, Triphala, and Shilajit in ethanol withdrawal- (EW-) induced anxiety behavior in rats. Ethanol dependence in rats was produced by substitution of drinking water with 7.5% v/v alcohol for 10 days. Then, ethanol withdrawal was induced by replacing alcohol with drinking water, 12 hours prior to experimentation. After confirming induction of withdrawal symptoms in the alcohol deprived animals, the anxiolytic activity of the test compound in graded doses (10, 20, and 40 mg/kg) was compared to the standard drug alprazolam (0.08 mg/kg) in the elevated plus maze and bright and dark arena paradigms. In our study, single and repeated dose administration of NR-ANX-C reduced EW-induced anxiety in a dose-dependent manner. Even though the anxiolytic activity was not significant at lower doses, NR-ANX-C at the highest dose tested (40 mg/kg) produced significant anxiolytic activity that was comparable to the standard drug alprazolam. Based on our findings we believe that NR-ANX-C has the potential to be used as an alternative to benzodiazepines in the treatment of EW-induced anxiety

ORMOSIL–ZrO2 hybrid nanocomposites and coatings on aluminium alloys for corrosion resistance; A sol-gel approach

Corrosion resistant coatings are prepared from a hybrid nanocomposite aerogel derived from tri-functional silanes, methyltrimethoxysilane (MTMS) and glycidyloxypropyl trimethoxysilane (GPTMS) and from a zirconium isopropoxide (ZIP) precursor which acts as an inorganic nano-dispersion in an organically modified silane (ORMOSIL) matrix. A series of hybrid compositions of MTMS and GPTMS are prepared in which the amount of ZIP is varied. The variations in the pH, viscosity and gelation time of the prepared compositions are monitored. The wet alcogels thus obtained are homogenized in a solvent using an ultrasonicator followed by coating the suspension on aluminium alloys and glass substrates using a dip coating unit. The prepared coatings are further dried and annealed at 400 °C for 1 h. The wet alcogels are also dried under ambient conditions for seven days resulting in hybrid nanocomposite aerogel monoliths and are calcined at 400 °C. The hybrid nanocomposites and coatings are further characterized using X-ray diffraction analysis, Fourier transform infrared spectroscopy, BET surface area analysis, X-ray photoelectron spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), UV-visible spectroscopy, potentiodynamic polarization and EIS measurements. The hybrid nanocomposite coated aluminium alloy shows enhanced corrosion protection when compared to the uncoated aluminium alloy. The anticorrosive feature of the ORMOSIL-ZrO2hybrid nanocomposite coatings makes them an important candidate in the field of protective environment resistant coatings

DISCOSOMES: A FUTURISTIC UPHEAVAL IN VESICULAR DRUG DELIVERY

The formulation system employed to convey pharmaceutical drugs compound in the body to attain the desired therapeutic effect at a predetermined rate depending on pharmacological aspects, drug profile, and physiological conditions can be referred to as a novel drug delivery system (NDDS). Due to the intricately sensitive anatomy and physiology of the eye pharmacologist find the ocular delivery system to be more involuted than other routes. Pre-corneal, static and dynamic is the 3 types of ophthalmic barriers, which along with the inflow and outflow of lacrimal fluids, nasolacrimal drainage, are some of the germane factors that affect bioavailability. Unlike conventional dosage forms, where the distribution of drugs in non-targeted body fluids and tissues transcends the quantity of required drug in targeted tissues and causes repercussions, these modified drug delivery systems surpass the ocular barriers and adverse reactions, emphasizing on less invasive, prolonged action. It also promotes sustained release formulation that subjugates the drug loss or degradation to treat many ocular diseases effectively. The current review recapitulates the fundamentals of discosomes, a type of vesicular drug delivery system that acts as a vehicle for the drug delivery of both hydrophilic and lipophilic drugs. Discosomes are giant, disc-shaped structures modified from niosomes by arresting the vesicles at the discosome phase. Due to their idiosyncratic size, it provides all due benefits compared to other ocular drug delivery systems. From the review, it can be culminated that discosomes are a potential subject of opposition and opportunities in the arena of safe and effective ocular drug delivery

Numerical Simulation of the 9-10 June 1972 Black Hills Storm Using CSU RAMS

Strong easterly flow of low-level moist air over the eastern slopes of the Black Hills on 9-10 June 1972 generated a storm system that produced a flash flood, devastating the area. Based on observations from this storm event, and also from the similar Big Thompson 1976 storm event, conceptual models have been developed to explain the unusually high precipitation efficiency. In this study, the Black Hills storm is simulated using the Colorado State University Regional Atmospheric Modeling System. Simulations with homogeneous and inhomogeneous initializations and different grid structures are presented. The conceptual models of storm structure proposed by previous studies are examined in light of the present simulations. Both homogeneous and inhomogeneous initialization results capture the intense nature of the storm, but the inhomogeneous simulation produced a precipitation pattern closer to the observed pattern. The simulations point to stationary tilted updrafts, with precipitation falling out to the rear as the preferred storm structure. Experiments with different grid structures point to the importance of removing the lateral boundaries far from the region of activity. Overall, simulation performance in capturing the observed behavior of the storm system was enhanced by use of inhomogeneous initialization

Tagging of Explosives for Detection

This paper gives the results of a study on estimation of shelf life of2,3-dimethyI2,3-dinitrobutane (DMNB)-tagged RDX and PETN expiosives by monitoring DMNB depletion by high performanceliquid chromatography and simultaneously recording the detectability of the tagged explosive composition using explosive vapoUf detector Model-97 HS. DMNB was incorporated in the explosive using methanol as solvent for DMNB and the explosive compositions were stored at 35,55 and 75 °C over a long period. Methods developed for preparing the homogeneously tagged composition with DMNB at 0.5 per cent level and for the analysis ofDMNB for ensuring homogeneity of DMNB in the composition are described. The results show no change in compatibility and sensitivity on the incorporation of DMNB in the explosive. Estimation of shelf life of DMNB in the explosive was done for a period of storage of 202-304 days at different temperatures

Computational studies on heterogenization of homogeneous catalyst of iron(III), nickel(II) and copper(II) N,N′-disalicylidene-1,2-phenylenediamine complex

Density functional theory (DFT) calculations were carried out on iron(III), nickel(II) and copper(II) complexes of N,N′-ethylenebis(salicylimine) both at molecular level (isolated complexes) and encapsulated in a zeolite framework to investigate changes that occur in their geometrical and electronic parameters as well as in their reactivity and stability. The computational results showed that the zeolite encapsulated metal complexes have higher reactivity and less stability as compared to the isolated metal complexes.               KEY WORDS: Density functional theory, N,N′-ethylenebis(salicylimine), Computational studies, Heterogenization, Electronic parameters Bull. Chem. Soc. Ethiop. 2019, 33(1), 91-102DOI: https://dx.doi.org/10.4314/bcse.v33i1.