Smart Loads for Voltage Control in Distribution Networks

This paper shows that the smart loads (SLs) could be effective in mitigating voltage problems caused by photovoltaic (PV) generation and electric vehicle (EV) charging in low-voltage (LV) distribution networks. Limitations of the previously reported SL configuration with only series reactive compensator (SLQ) (one converter) is highlighted in this paper. To overcome these limitations, an additional shunt converter is used in back-to-back (B2B) configuration to support the active power exchanged by the series converter, which increases the flexibility of the SL without requiring any energy storage. Simulation results on a typical U.K. LV distribution network are presented to compare the effectiveness of an SL with B2B converters (SLBCs) against an SLQ in tackling under- and over-voltage problems caused by EV or PV. It is shown that SLBCs can regulate the main voltage more effectively than SLQs especially under overvoltage condition. Although two converters are required for each SLBC, it is shown that the apparent power capacity of each converter is required to be significantly less than that of an equivalent SLQ

Studies on the behaviour of some mono-carboxylic acids at the solution-vapour interface

The behaviour of acetic, propionic and butyric acids at the solution-vapour interface at 30 has been studied systematically. The surface tensions and vapour-pressures of fourteen systems were measured and the Gibbs adsorption equation used to calculate surface excesses, ⌐ (_2) (^N), whilst the amounts of the individual components at the interface were calculated by well known methods. It is assumed that the thickness of the adsorbed phase is essentially monolayer in character. The orientation of the acids at the interface is assumed to be the ‘parallel’ one for adsorption from benzeno, carbon tetrachloride and cyclohexane and the 'perpendicular’ one for adsorption from ethyl alcohol and water. Two factors, - affinity between acid and solvent in the bulk and rate of lowering of surface tension of acid + solvent mixtures by the acids, have been need to account for the extent of acid adsorption at the interface. In general adsorption of acid increases with increasing chain length, although for the cyclohexane systems it decreases with increasing acid chain length. The occurrence of a mixed monolayer at the interface is observed for all the systems, and a uni-monolayer of acid is formed only from the pure component. For the water systems it is possible for the adsorbed layer to contain two water molecules along the length of the acid molecule due to the much smaller size of the water molecule. The present investigations have thrown further light on adsorption behaviour at the solution-vapour interface. A complete understanding of adsorption phenomenon at the interface, involving a reasonable assessment of thickness of the adsorbed layer, composition and orientations at the interface, etc., depends on the particular systems involved, on the properties of the solutions, and on the intermolecular interactions possible both in bulk solution and at the interface

Prunus domestica, Prunus persica and Prunus avium extracts: determination of radical scavenging activities and development of natural antioxidant emulsions

Background: Nowadays antioxidants from plants origin are considered as a promising source of biologically active substances; as synthetic agents are accompanied with a number of side effects.Materials and Methods: Three fruit extracts Prunus domestica (plum), Prunus persica (peach) and Prunus avium (cherry) of family Rosaceae and genus Prunus were prepared and characterized. These natural antioxidant extracts were used for the development of stable oil/water emulsions. DPPH (2, 2-diphenyl-1-picrylhydrazyl) assay was used to evaluate antioxidant activities of various fruit extracts alone and in emulsions containing these extracts. Novel o/w emulsions were developed by using a suitable combination of oil phase and aqueous phase loaded with natural fruit extracts. Physicochemical parameters i.e. organoleptic evaluation (color, liquefaction and phase separation), pH and conductivity were monitored at 8oC, 25oC, 40oC, 40oC + 75% relative humidity and 50oC for 3 months as per stability studies guidelines.Results: Various fruit extracts and emulsions containing these extracts showed good and comparable antioxidant activities. Test formulations containing fruit extracts (6%) showed good stability compared to control formulations and pH and conductivity were found as desired. Formulations were studied for patch test on 33 healthy human (female) volunteers and observed for any skin reaction. No skin irritation was observed.Conclusion: It can be concluded that the final formula was suitable for preparing new antioxidant emulsions loaded with pleasant fruity extracts which remain economical, effective and completely safe for human skin therefore, enhancing patient compliance.Key words: Prunus domestica; Prunus persica; Prunus avium; Rosaceae, antioxidant activity; novel formulations

Many lives of KATs - detector, integrator and modulator of cellular environment

Research over the past three decades has firmly established lysine acetyltransferases (KATs) as central players in regulating transcription. Recent advances in genomic sequencing, metabolomics, animal models and mass spectrometry technologies have uncovered unexpected new roles for KATs at the nexus between the environment and transcriptional regulation. Thousands of reversible acetylation sites have been mapped in the proteome that respond dynamically to the cellular milieu and maintain major processes such as metabolism, autophagy and stress response. Concurrently, researchers are continuously uncovering how deregulation of KAT activity drives disease, including cancer and developmental syndromes characterized by severe intellectual disability. These novel findings are reshaping our view of KATs away from mere modulators of chromatin to detectors of the cellular environment and integrators of diverse signalling pathways with the ability to modify cellular phenotype

Hispanic Subgroups, Acculturation, and Substance Abuse Treatment Outcomes

This study explored Hispanic subgroup differences in substance use treatment outcomes, and the relationship of acculturation characteristics to these outcomes. Data were from a multisite randomized clinical trial of motivational enhancement therapy versus treatment as usual in a sample of Spanish-speaking substance abusers. Participants were Cuban American (n = 34), Mexican American (n = 209), Puerto Rican (n = 78), and other Hispanic American (n = 54). Results suggested that Cuban Americans and individuals with more connection to Hispanic culture had lower treatment retention. Hispanics born in the U.S and those who spoke English at home had a lower percentage of days abstinent during weeks 5–16, although Puerto Ricans born in the U.S. and Cuban Americans living more years in the U.S. had a higher percentage of days abstinent in weeks 1–4 and 5–16, respectively. Results may inform future hypothesis-driven studies in larger Hispanic treatment seeking samples of the relationship between acculturation and treatment outcome

Formulation and characterization of modified release tablets containing ionizid using swellable polymers

The aim of this work was to develop swellable modified release (MR) isoniazid tablets using different combinations of polyvinyl acetate (PVAc) and sodium-carboxymethylcellulose (Na-CMC). Granules were prepared by moist granulation technique and then compressed into tablets. In vitro release studies for 12 hr were carried out in dissolution media of varying pH i.e. pH 1.2, 4.5, 7.0 and 7.5. Tablets of all formulations were found to be of good physical quality with respect to appearance (width and thickness), content uniformity, hardness, weight variation and friability. In vitro release data showed that increasing total polymer content resulted in more retarding effect. Formulation with 35% polymer content exhibited zero order release profile and it released 35% of the drug in first hr, later on, controlled drug release was observed upto the 12th hour. Formulations with PVAc to Na-CMC ratio 20:80 exhibited zero order release pattern at levels of studied concentrations, which suggested that this combination can be used to formulate zero order release tablets of water soluble drugs like isoniazid. Korsmeyer-Peppas modeling of drug release showed that non-Fickian transport is the primary mechanism of isoniazid release from PVAc and Na-CMC based tablets. The value of mean dissolution time decreased with the increase in the release rate of drug clearly showing the retarding behavior of the swellable polymers. The application of a mixture of PVAc to Na-CMC in a specific ratio may be feasible to formulate zero order release tablets of water soluble drugs like isoniazid.Keywords: Isoniazid, Polyvinyl acetate, Sodium-carboxymethylcellulose, Modified release tablets

The non-specific lethal (NSL) complex at the crossroads of transcriptional control and cellular homeostasis

The functionality of chromatin is tightly regulated by post-translational modifications that modulate transcriptional output from target loci. Among the post-translational modifications of chromatin, reversible ε-lysine acetylation of histone proteins is prominent at transcriptionally active genes. Lysine acetylation is catalyzed by lysine acetyltransferases (KATs), which utilize the central cellular metabolite acetyl-CoA as their substrate. Among the KATs that mediate lysine acetylation, males absent on the first (MOF/KAT8) is particularly notable for its ability to acetylate histone 4 lysine 16 (H4K16ac), a modification that decompacts chromatin structure. MOF and its non-specific lethal (NSL) complex members have been shown to localize to gene promoters and enhancers in the nucleus, as well as to microtubules and mitochondria to regulate key cellular processes. Highlighting their importance, mutations or deregulation of NSL complex members has been reported in both human neurodevelopmental disorders and cancer. Based on insight gained from studies in human, mouse, and Drosophila model systems, this review discusses the role of NSL-mediated lysine acetylation in a myriad of cellular functions in both health and disease. Through these studies, the importance of the NSL complex in regulating core transcriptional and signaling networks required for normal development and cellular homeostasis is beginning to emerge

Corrosion Control of Kunifer-5 Seawater Piping Systems of Naval Ships by Cathodic Protection Technique

The cause of premature corrosion of Kunifer-5(copper alloy containing Ni 5 per cent and Fe 1.35 per cent) pipes used in seawater piping systems on board ships for feeding seawater to various units has been discussed. It has been shown that the Kunifer-5 alloys suffer from heavy corrosion-erosion attack at unavoidable bends and places where local seawater velocity exceeds the specified limit. The field observations as well as laboratory study have indicated that satisfactory protection of the pipes could be achieved by galvanic cathodic protection using aluminium alloy anodes

A headspace-gas chromatography method for isopropanol determination in warfarin sodium products as a measure of drug crystallinity

Coumadin® and several generic products of warfarin sodium (WS) contain the crystalline form (clathrate) in which WS and isopropanol (IPA) are associated in a 2:1 molar ratio. IPA is critical in maintaining the WS crystalline structure. Physicochemical properties of the drug and drug product may change when the crystalline drug transforms to amorphous form. A headspace-gas chromatography (HS-GC) method was developed and validated for IPA determination in the WS drug product. n-propanol (NPA) was used as internal standard and the method was validated for specificity, system suitability, linearity, accuracy, precision, range, limits of detection and quantification, and robustness. The method was specific, with good resolution between IPA and NPA peaks. Chromatographic parameters (retention time, IPA/NPA area ratio, tailing factor, theoretical plates, USP symmetry, capacity factor, selectivity and resolution) were consistent over three days of validation. The analytical method was linear from 2–200 µg mL–1 (0.1–10 % IPA present in the drug product). LOD and LOQ were 0.1 and 2 µg mL–1, respectively. Accuracy at low (2 µg mL–1) and high (200 µg mL–1) IPA concentrations of the calibration curve was 103.3–113.3 and 98.9–102.2 % of the nominal value, resp. The validated method was precise, as indicated by the RSD value of less than 2 % at three concentration levels of the calibration curve. The method reported here was utilized to determine accurately and precisely the IPA content in in-house formulations and commercial products. In summary, IPA determination by HS-GC provides an indirect measure of WS crystallinity in the drug product. Nevertheless, it should be confirmed by another analytical method since IPA from the drug substance is not distinguishable from IPA that may be present outside the drug crystals in a dosage form when prepared by wet granulation with IPA