Synthesis of New Dibenzosulfide and Dibenzosulfoxide Macrocyclic Compounds

Some new dibenzosulfo, dibenzosulfoxo macrocyclic diamides are synthesized.     

Use of liquid chromatography for separation and determination of carrier species associated with the synthesis of no carrier-added11C-labelled compounds determination of the specific activity of {11C} urea

An analytical technique using reversed-phase liquid chromatography has been developed for the determination of urea at quantities as low as 1 ng to quantitate the amount of non-labelled urea produced during the synthesis of no-carrier-added {¹¹C}urea starting from¹¹CN^–. As a result, the specific activity of the {¹¹C} urea thus prepared was calculated to be as high as 3.5±0.8 Ci/mol.Research supported in part by PHS Grant NINCDS 1 PO1 NS 15639.     

Effects of Nonionic and Mixed Cationic-Nonionic Micelles on the Rate of Alkaline Hydrolysis of 4-Nitrophthalimide

Pseudo-first-order rate constants (k_obs) for alkaline hydrolysis of 4-nitrophthalimide show a monotonic decrease with increase in [C₁₂E₂₃]_T (total concentration of Brij 35) at constant [CH₃CN] and [NaOH]. This micellar effect is explained in terms of a pseudophase micelle model. The rate of hydrolysis becomes too slow to monitor at [C₁₂E₂₃]_T≥0.03 M in the absence of cetyltrimethylammonium bromide (CTABr) and at [C₁₂E₂₃]_T≥0.04 M in the presence of 0.006–0.02 M CTABr at 0.01 M NaOH. The plots of k_obs versus [C₁₂E₂₃]_T show minima at 0.006 and 0.01 M CTABr, while such a minimum is not visible at 0.02 M CTABr.     

Comparative analysis of refrigerant performance between LPG and R134a under subtropical climate

Journal of Thermal Analysis and Calorimetry - In this investigation, a series of experiments were conducted to explore the effects of liquefied petroleum gas (LPG) mixture of 60% propane and 40%...     

SYNTHESIS OF NEW BENZOSULFOXIDE MACROCYCLIC COMPOUNDS

Bis(dibenzosulfoxo)-27,30,35,38-tetramethyl-24-crown-6, bis(dibenzosulfoxo)-21,24,29,32-tetramethyl-18-crown-4, dibenzosulfoxo-15,18-dimethyl-12-crown-3 and dibenzosulfoxo-12,15-dimethyl-9-crown-2 macrocycles are synthesized by the reaction of 2,2′-sulfinyl-bis(4-methyl phenol)and 1,2-dibromoethane and diethyleneglycol di-p-toluenesulfonate.     

Clathrate formation and dissociation in vapor/water/ice/hydrate systems in SBA-15, sol-gel and CPG porous media, as probed by NMR relaxation, novel protocol NMR cryoporometry, neutron scattering and ab initio quantum-mechanical molecular dynamics simulation

The Gibbs-Thomson effect modifies the pressure and temperature at which clathrates occur, hence altering the depth at which they occur in the seabed. Nuclear magnetic resonance (NMR) measurements as a function of temperature are being conducted for water/ice/hydrate systems in a range of pore geometries, including templated SBA-15 silicas, controlled pore glasses and sol-gel silicas. Rotator-phase plastic ice is shown to be present in confined geometry, and bulk tetrahydrofuran hydrate is also shown to probably have a rotator phase. A novel NMR cryoporometry protocol, which probes both melting and freezing events while avoiding the usual problem of supercooling for the freezing event, has been developed. This enables a detailed probing of the system for a given pore size and geometry and the exploration of differences between hydrate formation and dissociation processes inside pores. These process differences have an important effect on the environment, as they impact on the ability of a marine hydrate system to re-form once warmed above a critical temperature. Ab initio quantum-mechanical molecular dynamics calculations are also being employed to probe the dynamics of liquids in pores at nanometric dimensions.     

Preparation and characterization of gamma irradiated ZnO/PANI hybrid films

Journal of Radioanalytical and Nuclear Chemistry - In this study, Zinc Oxide/Polyaniline (ZnO/PANI) hybrid was successfully synthesized using the combination of in-situ chemical oxidative...     

The Multifunctional Role of Herbal Products in the Management of Diabetes and Obesity: A Comprehensive Review

Obesity and diabetes are the most demanding health problems today, and their prevalence, as well as comorbidities, is on the rise all over the world. As time goes on, both are becoming big issues that have a big impact on people’s lives. Diabetes is a metabolic and endocrine illness set apart by hyperglycemia and glucose narrow-mindedness because of insulin opposition. Heftiness is a typical, complex, and developing overall wellbeing worry that has for quite some time been connected to significant medical issues in individuals, all things considered. Because of the wide variety and low adverse effects, herbal products are an important hotspot for drug development. Synthetic compounds are not structurally diverse and lack drug-likeness properties. Thus, it is basic to keep on exploring herbal products as possible wellsprings of novel drugs. We conducted this review of the literature by searching Scopus, Science Direct, Elsevier, PubMed, and Web of Science databases. From 1990 until October 2021, research reports, review articles, and original research articles in English are presented. It provides top to bottom data and an examination of plant-inferred compounds that might be utilized against heftiness or potentially hostile to diabetes treatments. Our expanded comprehension of the systems of activity of phytogenic compounds, as an extra examination, could prompt the advancement of remedial methodologies for metabolic diseases. In clinical trials, a huge number of these food kinds or restorative plants, as well as their bioactive compounds, have been shown to be beneficial in the treatment of obesity.     

An Accurate Space–Time Pseudospectral Method for Solving Nonlinear Multi-Dimensional Heat Transfer Problems

In this paper, we consider the numerical solution of the nonlinear one- and two-dimensional heat transfer problems subject to the given initial conditions and linear Robin boundary conditions. We propose a pseudospectral scheme in both time and spatial discretizations for these problems. The discretization processes are constructed through the multi-variate interpolation of the desired solutions in terms of Chebyshev Gauss Lobbato collocation points. Operational matrices of differentiation are constructed via the tensor products for speeding up of the proposed numerical algorithms’ implementation. Some test problems are provided and the numerical simulations are illustrated to show the spectral accuracy in both space and time of the suggested scheme.     

Synthesis,Characterization and Photocatalytic Activity of Mg‐Impregnated ZnO–SnO2 Coupled Nanoparticles

ZnO–SnO₂ nanoparticles were prepared by coprecipitation method; then Mg, with different molar ratios and calcination temperatures, was loaded on the coupled nanoparticles by impregnation method. The synthesized nanoparticles were characterized by X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X‐ray spectroscopy (EDX), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), and Brunauer–Emmett–Teller (BET) techniques. Based on XRD results, the ZnO–SnO₂ and Mg/ZnO–SnO₂ nanoparticles were made of ZnO and SnO₂ nanocrystallites. According to DRS spectra, the band gap energy value of 3.13 and 3.18 eV were obtained for ZnO–SnO₂ and Mg/ZnO–SnO₂ nanoparticles, respectively. BET analysis revealed a Type III isotherm with a microporous structure and surface area of 32.051 and 49.065 m² g^?1 for ZnO–SnO₂ and Mg/ZnO–SnO₂, respectively. Also, the spherical shape of nanocrystallites was deduced from TEM and FESEM images. The photocatalytic performance of pure ZnO–SnO₂ and Mg/ZnO–SnO₂ was analyzed in the photocatalytic removal of methyl orange (MO). The results indicated that Mg/ZnO–SnO₂ exhibited superior photocatalytic activity to bare ZnO–SnO₂ photocatalyst due to high surface area, increased MO adsorption and larger band gap energy. Maximum photocatalytic activity of Mg/ZnO–SnO₂ nanoparticles was obtained with 0.8 mol% Mg and calcination temperature of 350°C.