210 research outputs found
The Integration of Smart Meters into Electrical Grids: Bangladesh Chapter
The Smart Metering Technology paves way for increased utilization of green power through Renewable Energy Sources. With the introduction of Smart Metering Technology at Distribution level, the consumer shall have an incentive to switch on their appliances time specific, to have the benefit of choice of low cost power. This paper identifies specific issues that could be developed for Bangladesh’s deployment of Smart Metering Infrastructure, recommends appropriate goals, key strategies, and critical objectives in solving those shortcomings, and outlines a practical program, identifying key tasks and necessary expert capabilities, to accomplish that solution in a timely and affordable manner. Keywords: AMR, AMI, AMM, Power Line Carrier (PLC
Modeling cancer genomic data in yeast reveals selection against ATM function during tumorigenesis
The DNA damage response (DDR) comprises multiple functions that collectively preserve genomic integrity and suppress tumorigenesis. The Mre11 complex and ATM govern a major axis of the DDR and several lines of evidence implicate that axis in tumor suppression. Components of the Mre11 complex are mutated in approximately five percent of human cancers. Inherited mutations of complex members cause severe chromosome instability syndromes, such as Nijmegen Breakage Syndrome, which is associated with strong predisposition to malignancy. And in mice, Mre11 complex mutations are markedly more susceptible to oncogene- induced carcinogenesis. The complex is integral to all modes of DNA double strand break (DSB) repair and is required for the activation of ATM to effect DNA damage signaling. To understand which functions of the Mre11 complex are important for tumor suppression, we undertook mining of cancer genomic data from the clinical sequencing program at Memorial Sloan Kettering Cancer Center, which includes the Mre11 complex among the 468 genes assessed. Twenty five mutations in MRE11 and RAD50 were modeled in S. cerevisiae and in vitro. The mutations were chosen based on recurrence and conservation between human and yeast. We found that a significant fraction of tumor-borne RAD50 and MRE11 mutations exhibited separation of function phenotypes wherein Tel1/ATM activation was severely impaired while DNA repair functions were mildly or not affected. At the molecular level, the gene products of RAD50 mutations exhibited defects in ATP binding and hydrolysis. The data reflect the importance of Rad50 ATPase activity for Tel1/ATM activation and suggest that inactivation of ATM signaling confers an advantage to burgeoning tumor cells
Improving distribution system state estimation with synthetic measurements
Distribution state estimation is a desired feature of modern power systems. The availability of measurements from smart meters has opened the door to extend the application of state estimation techniques down to end customers, preferably at the secondary distribution transformer level. However, the light coupling between phases makes the estimation of certain state variables, such as voltage phase angles, a great challenge. This paper proposes the use of synthetic measurements as a means of including cross-coupled information in the available set of measurements. This possibility can be easily implemented in line supervisors located at secondary transformer stations without the need for new hardware, just by embracing a different connection of measurement devices. This work demonstrates that this costless action results in a strong reduction of the sensibility of phase angle estimation errors with respect to measurement noise, thus leading to an important improvement in the quality of the results.publishedVersio
Antifungal activities and chemical characterization of Neem leaf extracts on the growth of some selected fungal species in vitro culture medium.
The efficacy of different extracts of neem leaf on seed borne fungi
Aspergillus , Rhizopus and chemical characterization of the neem
leaf extracts were studied in vitro on the culture medium. The growth
of both the fungal species was inhibited significantly (p<0.01) and
controlled with both alcoholic and water extract of all ages and of the
concentrations used. The alcoholic extracts of neem leaf was most
effective in comparison to aqueous extract for retarding the growth of
Rhizopus and Aspergillus. The crude aqueous and alcoholic leaf extracts
of neem was more effective in inhibitions of growth of the fungi
Aspergillus in comparison to inhibitory effects on Rhizopus growth in
the artificial culture medium. Leaf extracts of neem which are cheap
and environmentally safe are promising for protecting crop species
against the fungal infestation and leading towards improvement of the
crop in terms of yield and productivity. @ JASE
Inmobilization of Zn(II) in Portland cement pastes. Determination of microstructure and leaching performance
The aim of this paper is to study the solidification/ stabilization potential of cementitious matrices on
the immobilization of Zn(II) before its disposal into the environment by determining the mechanisms of interaction between the Zn(II) ions and the binder. The results of structural and mineralogical characterization of cement pastes formed with different amounts of immobilized Zn(II) ions are presented and the study includes results from thermogravimetric analysis (TG), scanning electron
microscopy, X-ray diffraction, and leaching performance. Zn(II) ions delay the hydration reaction of Portland cement
due to the formation of mainly CaZn2(OH)6 2H2O , as well
as Zn5(CO3)2(OH)6, Zn(OH)2, and ZnCO3 in minor proportion.
Correlations between total mass loss in TG analysis
and leached Zn(II) ions in long-term curing pastes
have been obtained. This result is important because in a
preliminary approach from a TG on an early-aged cement
paste containing Zn(II), it could be possible to perform an
estimation of the amount of Zn(II) ions that could be leached,
thus avoiding costly and time-consuming tests.Mellado Romero, AM.; Borrachero Rosado, MV.; Soriano Martinez, L.; Paya Bernabeu, JJ.; Monzó Balbuena, JM. (2013). Inmobilization of Zn(II) in Portland cement pastes. Determination of microstructure and leaching performance. Journal of Thermal Analysis and Calorimetry. 112(3):1377-1389. doi:10.1007/s10973-012-2705-8S137713891123Mojumdar SC, Sain M, Prasad RC, Sun L, Venart JES. Selected thermoanalytical methods and their applications from medicine to construction, Part I. J Therm Anal Calorim. 2007;90:653–62.Perraki M, Perraki T, Kolovos K, Tsivilis S, Kakali G. Secondary raw materials in cement industry. Evaluation of their effect on the sintering and hydration processes by thermal analysis. J Therm Anal Calorim. 2002;70:143–50.Neves A, Dias Toledo R, de Moraes Rego E, Dweck J. Early stages hydration of high initial strength Portland cement. Part I. Thermogravimetric analysis on calcined mass basis. J Therm Anal Calorim. 2012;108:725–31. doi: 10.1007/s10973-012-2256-z .Balek V, Bydžovský J, Dufka A, Drochytka R, Beckman IN. Use of emanation thermal analysis to characterize microstructure development during Portland cement hydration. J Therm Anal Calorim. 2012. doi: 10.1007/s10973-012-2314-6 .Zhang Q, Ye G. Dehydration kinetics of Portland cement paste at high temperature. J Therm Anal Calorim. 2012. doi: 10.1007/s10973-012-2303-9 .Menéndez E, Vega L, Andrade C. Use of decomposition of portlandite in concrete fire as indicator of temperature progression into the material. Application to fire-affected builds. J Therm Anal Calorim. 2012. doi: 10.1007/s10973-011-2159-4 .Galan I, Andrade C, Castellote M. Thermogravimetrical analysis for monitoring carbonation of cementitious materials. Uptake of CO2 and deepening in C–S–H knowledge. J Therm Anal Calorim. 2012. doi: 10.1007/s10973-012-2466-4 .Batchelor B. Overview of waste stabilization with cement. Waste Manag (Oxford). 2006;26:689–98.Gineys N, Aouad G, Damidot D. Managing trace elements in Portland cement-Part I: interactions between cement paste and heavy metals added during mixing as soluble salts. Cem Concr Compos. 2010;32:563–70.Erdem M, Özverdi A. Environmental risk assessment and stabilization/solidification of zinc extraction residue: II. Stabilization/solidification. Hydrometallurgy. 2011;105:270–6.Nocuń-Wczelik W, Małolepszy J. Application of calorimetry in studies of the immobilization of heavy metals in cementitious materials. Thermochim Acta. 1995;269(270):613–9.Dweck J, Buchler PM, Cartledge FK. The effect of different bentonites on cement hydration during solidification/stabilization of tannery wastes. J Therm Anal Calorim. 2001;64:1011–6.Melchert MBM, Viana MM, Lemos MS, Dweck J, Buchler PM. Simultaneous solidification of two catalyst wastes and their effect on the early stages of cement hydration. J Therm Anal Calorim. 2011;105:625–33.Vessalas K, Thomas PS, Ray AS, Guerbois JP, Joyce P, Haggman J. Pozzolanic reactivity of the supplementary cementitious material pitchstone fines by thermogravimetric analysis. J Therm Anal Calorim. 2009;97:71–6.Tommaseo CE, Kersten M. Aqueous solubility diagrams for cementitious waste stabilization systems. 3. Mechanism of zinc immobilization by calcium silicate hydrate. Environ Sci Technol. 2002;36:2919–25.Peyronnard O, et al. Study of mineralogy and leaching behavior of stabilized/solidified sludge using differential acid neutralization analysis. Cem Conc Res. 2009. doi: 10.1016/j.cemconres.2009.03.016 .Moulin I, et al. Lead, zinc and chromium (III) and (VI) speciation in hydrated cement phases. International conference on the science and engineering of recycling for environmental protection, waste materials in construction (WASCON 2000), Harrogate, England, 2000, pp. 269–280.Ziegler F, Gieré R, Johnson CA. Sorption mechanisms of zinc to calcium silicate hydrate: sorption and microscopic investigations. Environ Sci Technol. 2001;35:4556–61.Qiao XC, Poon CS, Cheeseman CR. Investigation into the stabilization/solidification performance of Portland cement through cement clinker phases. J Hazard Mater. 2007;B139:238–43.Chen QY, et al. Immobilisation of heavy metal in cement-based solidification/stabilisation: a review. Waste Manag (Oxford). 2009;29:390–403.Chen QY, et al. Characterisation of products of tricalcium silicate hydration in the presence of heavy metals. J Hazard Mater. 2007;147:817–25.Fernandez-Olmo I, Chacon E, Irabien A. Influence of lead, zinc, iron (III) and chromium (III) oxides on the setting time and strength development of Portland cement. Cem Concr Res. 2001;31:1213–9.Fernandez-Olmo I, Chacon E, Irabien A. Leaching behavior of lead, chromium (III) and zinc in cement/metal oxides systems. ASCE J Environ Eng. 2003;129:532–8.Cappuyns V, Swennenb R. The application of pHstat leaching tests to assess the pH-dependent release of trace metals from soils, sediments and waste materials. J Hazard Mater. 2008;158:185–95.Payá J, Monzó J, Borrachero MV, Velázquez S. Evaluation of the pozzolanic activity of fluid catalytic cracking catalyst residue (FC3R): thermogravimetric analysis studies on FC3R-Portland cement pastes. Cem Concr Res. 2003;33:603–9.Wang S, Yang Z, Zeng L. Study of calcium zincate synthesized by solid-phase synthesis method without strong alkali. Mater Chem Phys. 2008;112:603–6.Stumm A, et al. Incorporation of zinc into calcium silicate hydrates, Part I: formation of C–S–H(I) with C/S = 2/3 and its isochemical counterpart gyrolite. Cem Concr Res. 2005;35:1665–75.Stephan D, Mallmann R, Knöfel D, Härdtl R. High intakes of Cr, Ni, and Zn in clinker, Part II. Influence on the hydration properties. Cem Concr Res. 1999;29:1959–67.Liu Y, et al. Thermal decomposition of basic zinc carbonate in nitrogen atmosphere. Thermochim Acta. 2004;414:121–3.Wahab R, et al. Synthesis and characterization of hydrozincite and its conversion into zinc oxide nanoparticles. J Alloy Compd. 2008;461:66–71.Hatakeyama T, Liu Z. Handbook of thermal analysis. New Yok: Wiley; 2000
Late presenters to HIV care and treatment, identification of associated risk factors in HIV-1 infected Indian population
<p>Abstract</p> <p>Background</p> <p>Timely access to antiretroviral therapy is a key to controlling HIV infection. Late diagnosis and presentation to care diminish the benefits of antiretrovirals and increase risk of transmission. We aimed to identify late presenters in patients sent for first CD4 T cell count after HIV diagnosis, for therapy initiation evaluation. Further we aimed at identifying patient factors associated with higher risk of late presentation.</p> <p>Methods</p> <p>Retrospective data collection and analysis was done for 3680 subjects visiting the laboratory for CD4 T cell counts between 2001 and 2007. We segregated the patients on basis of their CD4 T cell counts after first HIV diagnosis. Factors associated with risk of late presentation to CD4 T cell counts after HIV diagnosis were identified using univariate analysis, and the strength of association of individual factor was assessed by calculation of odds ratios.</p> <p>Results</p> <p>Of 3680 subjects, 2936 (83.37%) were defined as late presenters. Late testing varied among age groups, transmission categories, and gender. Males were twice as likely to present late as compared to females. We found significant positive association of heterosexual transmission route (<it>p </it>< 0.001), and older age groups of 45 years and above (<it>p </it>= 0.0004) to late presentation. Female sex, children below 14 years of age and sexual contact with HIV positive spouse were associated with significantly lower risks to presenting late. Intravenous drug users were also associated with lower risks of late presentation, in comparison to heterosexual transmission route.</p> <p>Conclusions</p> <p>The study identifies HIV infected population groups at a higher risk of late presentation to care and treatment. The risk factors identified to be associated with late presentation should be utilised in formulating targeted public health interventions in order to improve early HIV diagnosis.</p
Pre-ART retention in care and prevalence of tuberculosis among HIV-infected children at a district hospital in southern Ethiopia
[Cu(X-salicylato)2(N,N-diethylnicotinamide)2(H2O)2] complexes: conformational polymorphism and its consequence in supramolecular hydrogen-bonding networks formation
Topically Applied Ceramides Interact with the Stratum Corneum Lipid Matrix in Compromised Ex Vivo Skin
Drug Delivery Technolog
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