Synthesis and adsorption of functionalized polystyrenes/

The effect of specifically interacting functional groups (sticky foot) located at the chain ends of polystyrene on the adsorption rate, adsorbance, graft density and surface excess are discussed from cyclohexane, a theta solvent and toluene. Polystyrenes with hydroxyl and carboxylic acid end-groups (PS-OH, PS-COOH, HO-PS-OH and HOOC-PS-COOH) in narrow molecular weight distribution are synthesized by anionic polymerization of styrene followed by suitable termination reactions. Thin layer chromatography (TLC) is developed as an analytical technique to predict trends in the adsorption of the polymers in a range of solvents. In particular the information about the location of the end-group and therefore different chain architectures at the interface are inferred from this simple technique. Adsorption isotherms are obtained for each of the functionalized polymers of four different molecular weights, the selection of which was based on the TLC results. Kinetics of adsorption and the adsorbance data are determined by liquid scintillation counting of tritium labelled polymers. Graft density and surface excess data are calculated from the adsorbance data and other known parameters. It is shown, from these data, that polystyrenes with a carboxylic acid end-group form weakly stretched brushes at the glass-cyclohexane interface and mushrooms at the glass-toluene interface a result consistent with the higher osmotic repulsions towards packing in good solvents. Polystyrenes with functional groups at both the chain ends are hypothesized to form a range of structures from those dominated by tails at higher concentrations to those dominated by loops (in a good solvent) and trains (in a theta solvent) at lower solution concentrations. At higher molecular weights it is shown that functionalized polystyrenes behave as though they are not functionalized a result consistent with the TLC predictions. Hydroxyl end-group is shown to be an ineffective sticky foot from its adsorbance vis-a-vis polystyrene. The segment density distribution away from a polished silicon surface for a carboxylic acid end-functionalized polystyrene adsorbed from cyclohexane is determined by neutron reflection technique. The dry film thicknesses of polymer modified glass surfaces are determined by x-ray photoelectron spectroscopy. It is shown from the water contact angle data that a highly hrdrophilic surface of glass is converted to a completely hydrophobic surface by the adsorption of the functionalized polystyrenes. (Abstract shortened by UMI.

N,N′-(1,4-Phenyl­ene)bis­(2-bromo-2-methyl­propanamide)

The mol­ecular structure of the title compound, C14H18Br2N2O2, has one half-mol­ecule in the asymmetric unit. The mol­ecule has a crystallographic inversion centre in the middle of the benzene ring. The C—C—N—C torsion angle between the benzene ring and the bromo­amide group is 149.2 (7)°. The crystal is stabilized by a strong inter­molecular N—H⋯O bond and weak C—H⋯O inter­actions. These contacts give rise to a three-dimensional network

SCREENING, ISOLATION, AND ANTIBACTERIAL ACTIVITY OF ANTIBIOTIC PRODUCING BACTERIA OBTAINED FROM SAPROPHYTIC SOIL SAMPLES

ABSTRACTObjective: The aim of the study was conducted to screen and isolate potential antibiotic producing bacteria from saprophytic soils collected fromPotheri and Nandiambakkam.Methods: Soil was collected aseptically and subjected to serial dilution. Crowded plate technique was used for the isolation of the colony. Totallyseven isolates were isolated and were screened for their antibacterial activity. The three isolates (S2A, S2B, and S3A) having better zone of inhibitionwere selected for morphological, microscopical, and biochemical test to prove their validity. The selected isolates were partially purified. The partiallypurified samples further screened for antibacterial activity, minimum inhibitory concentration (MIC) and the isolates, which shown good zone ofinhibition were subjected to 16S rRNA sequencing studies to determine the species.Results: The isolates screened based on size of the zone formed. Best isolate selected by zone of inhibition was subjected to antibacterial activity,morphological, microscopical, and biochemical test, partial purification of three isolates and further screened for antibacterial and MIC. The isolateshowed good zone of inhibition compared to others by MIC was selected for 16S rRNA sequencing studies. Genomic DNA extracted from isolate S2Bconforms it belongs to Pseudomonas species which is named as Pseudomonas putida 2435.Conclusion: The research work revealed that the three isolates showed good antibacterial activity against Gram-positive and Gram-negative bacteria.The S2B isolate was confirmed to P. putida 2435 by 16S rRNA studies.Keywords: Isolation of soil microbes, Biochemical characterization, Antimicrobial activity, Minimum inhibitory concentration, 16S rRNA sequencing,Pseudomonas putida

Validation of photovoltaics powered UPQC using ANFIS controller in a standard microgrid test environment

The power quality improvement becomes one of the important tasks while using microgrid as main power supply. Because the microgrid is combination of renewable energy resources. The renewable energy resources are intermittent in power supply and at the peak loading condition it has to supply the required power. So, the power quality problems may increase in that time. Out of all power quality issues the voltage drop and harmonic distortion is considered as the most serious one. In recent years unified power quality conditioner (UPQC) is emerged as most promising device which compensates both utility as well as customer side power quality disturbances in effective way. The compensating potentiality used in the UPQC is limited by the use of DC link voltage regulation and the conventional proportional integral (PI) controller. In this paper the compensating potentiality of the UPQC device is controlled by an adaptive neuro fuzzy inference system (ANFIS) control and it is powered from the available photovoltaics (PV) power generation. The effect of adding an intelligent UPQC is tested in the standard IEEE-14bus environment. MATLAB 2017b is used here for testing and plotting the simulation results

3-({[(1-Phenyl­eth­yl)sulfan­yl]methane­thio­yl}sulfan­yl)propanoic acid

In the title compound, C12H14O2S3, a chain transfer agent (CTA) used in polymerization, the dihedral angle between the aromatic ring and the CS3 grouping is 84.20 (10)°. In the crystal, carb­oxy­lic acid inversion dimers linked by pairs of O—H⋯O hydrogen bonds generate R 2 2(8) loops

2,4,6-Trimethyl-3,5-bis[(phenylcarbono­thioyl)sulfanylmethyl]benzyl benzenecarbodithioate

In the title compound C33H30S6, the three pendant methyl­ene benzodithio­ate groups lie to one side of the central benzene ring in a cis-cis-cis ‘tripod’ arrangement. The dihedral angles between the central benzene ring and the three pendant rings are 72.54 (4), 89.68 (4) and 86.74 (4)°. In the crystal structure, one of the benzene rings is disordered over two orientations in a 0.559 (13):0.441 (13) ratio

2-Oxo-4-trifluoro­meth­yl-2H-chromen-7-yl 2-bromo-2-methyl­propano­ate

In the title compound, C14H10BrF3O4, the coumarin ring system is almost plannar (r.m.s. deviation = 0.025 Å) and a short C—H⋯F contact occurs. The propano­ate fragment is orientated almost perpendicular to the ring [dihedral angle = 71.80 (12)°]. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, generating [100] chains

2-Bromo-2-methyl-N-(4-methyl-2-oxo-2H-chromen-7-yl)propanamide

In the title compound C14H14BrNO3, the coumarin ring system is almost planar (r.m.s. deviation = 0.008 Å) and an intra­molecular C—H⋯O inter­action generates an S(6) ring. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds, with the C=O unit of the coumarin ring system acting as the acceptor group, generating [010] C(8) chains. The chain connectivity is reinforced by two C—H⋯O inter­actions

Systematic review on nine hallmarks of neurodegenerative disease

249-257Alzheimer's disease (AD) and Parkinson's disease (PD) are the primary diseases in neurodegenerative diseases. Nowadays, AD is common in one of the ten individuals whose age is more than 65, and its prevalence is kept on increasing with aging. Very few treatments and no effective treatments are available for curing neurodegenerative diseases. Pathogenesis of neurodegenerative diseases, Alzheimer's disease, Parkinson's disease, and their association with the nine hallmarks of aging were clearly described in this review. Instability in genomic, attrition in telomere, alterations in epigenetics, proteostasis loss, dysfunction in mitochondria, senescence in cells, sensing of deregulated nutrition, exhaustion of stem cells, and alterations in intercellular communication are the nine biological hallmarks of Aging. Improving the medical facilities for neurodegenerative diseases is very much essential. Doctors and researchers are doing surplus research to overcome the unavailability of proper treatments for such neurodegenerative diseases. Reason and the causes behind the diseases and their effects are explained in this review to enhance the further research to help the society