System Archetypes Underlying Formal-Informal Urban Water Supply Dynamics

Water Resources Management - Contrary to developed countries, developing countries have been observed to have an increased reliance on a diversity of water supply options to meet their daily...     

Pleurotus mushrooms. Part II. Chemical composition, nutritional value, post-harvest physiology, preservation, and role as human food

The fruit bodies of Pleurotus species as a class of "Edible Fungal Foods" have been discovered to have definite nutritive and medicinal values. They are a good source of nonstarchy carbohydrates, dietary fiber (that can help in reducing the plasma cholesterol), most of the essential amino acids, minerals and vitamins of B group, and folic acid (necessary to counteract pernicious anaemia) in particular. Considering the essential amino acid index, biological value, in vitro digestibility, nutritional index, and protein score, Pleurotus species fall between high grade vegetables and low grade meats. Fractions of water-soluble polysaccharides are reported to possess antitumor activity. The physiological processes such as changes in water content, respiratory rate, texture, color, and activities of enzymes like proteases and polyphenol oxidases during the after-harvest life are delineated. The problems and prospects of processing the fruit bodies by various methods are discussed. Potentialities for production and consumption of the fruit bodies in different parts of the world are brought out.     

Atmospheric corrosion kinetics and dynamics of electrogalvanized mild steel in southeastern coastal area of China–Pakistan Economic Corridor

This study aims to examine atmospheric corrosivity, corrodants, and corrosion products of southeastern coastal area of China–Pakistan Economic Corridor as per ISO protocols 9223 and 9225, and ASTM standards G1, G50, G140-02, D4458-94, and D2010. Test sites are located at National Institute of Oceanography (NIO) and Karachi Port Trust (KPT) at the banks of the Arabian Sea. Electrogalvanized mild steel test coupons were exposed, and levels of corrodants (sulfur dioxide, chloride, and time of wetness) were measured for a period of 24 months, from May 2014 to May 2016. Corrosivity category C5+ is established in terms of the corrosion rate for both NIO and KPT test stations, which does not coincide with the corrosivity category C5 ascertained by employing environmental characteristics and atmospheric corrodants. Corrosion kinetic parameter “n” and correlation coefficient (R²) are 0.71 and 0.97 for NIO and 0.96 and 0.97 for KPT, respectively. Scanning electron microscopy/energy-dispersive spectroscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction spectroscopy have corroborated the presence of simonkolleite and hydrozincite, zinc oxide, zinc hydroxychloride, and zinc in corrosion products at both test sites.     

Physicochemical studies of galvanized steel corrosion in urban,industrial, and marine environments,and corrosion mapping of Karachi city: An important coastal city of the 21st-century modern maritime silk route

The coastal city of Karachi is an imperative part of China–Pakistan Economic Corridor, which is integrated with the modern maritime silk route of the 21st century. This paper presents the corrosion mapping and physicochemical studies of galvanized steel corrosion exposed at the urban, industrial, and marine test sites located in the Karachi coastal city from July 2018 to June 2019. Tests have been performed to determine chloride, sulfur dioxide, time of wetness (TOW), and corrosion rates as per ISO protocols 9223 and 9225, and ASTM standards G1, G50, G140-02, D4458-94, and D2010. All test sites have been assigned the C5+ corrosivity category, based on corrosion rates of the galvanized steel, which is not completely in line with the corrosivity category derived from atmospheric pollutants and TOW values for these test sites. SEM/EDS, XRD, and FTIR have characterized the presence of simonkolleite, hydrozincite, and zincite at nearly all the test sites, whereas gordaite is only detected at the marine test sites. Zinc(I) chlorohydroxysulfate is also observed at an urban test site. This study has furnished a novel product of a galvanized steel corrosion map for Karachi, Pakistan.     

Photochemical interaction of ascorbic acid with riboflavin, nicotinamide and alpha-tocopherol in cream formulations

The present work is based on a study of the effect of some vitamins such as riboflavin (RF), nicotinamide (NA) and alpha‐tocopherol (TP) on the photodegradation of ascorbic acid (vitamin C) (AH₂) in oil‐in‐water cream formulations using a UV irradiation source. A UV spectrophotometric and the official iodimetric methods have been used for the assay of AH₂ in cream formulations. These methods have been validated in the presence of RF, NA and TP before their application to the creams. The recoveries of AH₂ in the creams are in the range of 90–95% and the reproducibility of the method is within ±5%. The apparent first‐order rate constants (k_obs) for the photodegradation of AH₂ in the presence of RF, NA and TP, individually, in the creams have been obtained. The second‐order rate constants for the photochemical interaction of AH₂ and the vitamins RF, NA and TP have been determined from the plots of k_obs for AH₂ photolysis versus the individual vitamin concentration along with the values of k₀ from the intercept on the vertical axis. The values of k₀ in the presence of RF and NA are lower than those of the k_obs, indicating that these vitamins act as photosensitizers for the degradation of AH₂ in creams. On the contrary, the value of k₀ in the presence of TP is higher than that of the k_obs, suggesting a stabilizing effect of this vitamin on the degradation of AH₂ in creams. The mode of interaction of the individual vitamins with AH₂ on photolysis has been discussed.     

Nanoscale elastic modulus of single horizontal ZnO nanorod using nanoindentation experiment

We measure the elastic modulus of a single horizontal ZnO nanorod [NR] grown by a low-temperature hydrothermal chemical process on silicon substrates by performing room-temperature, direct load-controlled nanoindentation measurements. The configuration of the experiment for the single ZnO NR was achieved using a focused ion beam/scanning electron microscope dual-beam instrument. The single ZnO NR was positioned horizontally over a hole on a silicon wafer using a nanomanipulator, and both ends were bonded with platinum, defining a three-point bending configuration. The elastic modulus of the ZnO NR, extracted from the unloading curve using the well-known Oliver-Pharr method, resulted in a value of approximately 800 GPa. Also, we discuss the NR creep mechanism observed under indentation. The mechanical behavior reported in this paper will be a useful reference for the design and applications of future nanodevices.     

Targeting microbial biofilms: by Arctium lappa l. synthesised biocompatible CeO2 ‐NPs encapsulated in nano‐chitosan

This study is planned to synthesise new biocompatible, nano antimicrobial formulation against biofilm producing strains. Aqueous root extract of Arctium lappa l. was used to synthesise ceria nanoparticles (CeO₂ ‐NPs). The synthesised nanoparticles were encapsulated with nano‐chitosan by sol–gel method and characterised using standard techniques. Gas chromatography‐mass spectrometer of Arctium lappa l. revealed the presence of ethanol, acetone, 1‐ propanol, 2‐methylethane, 1,1‐di‐ethoxy, 1‐Butanol, and oleic acid acted as reducing and surface stabilising agents for tailoring morphology of CeO₂ ‐NPs. Erythrocyte integrity after treatment with synthesised nanomaterials was evaluated by spectrophotometer measurement of haemoglobin release having biocompatibility. Scanning electron microscopy revealed the formation of mono dispersed beads shaped particles with mean particle size of 26.2 nm. X‐ray diffractometry revealed cubic crystalline structure having size of 28.0 nm. After encapsulation by nano‐chitosan, the size of CeO₂ ‐NPs enhances to 48.8 nm making average coverage of about 22.6 nm. The synthesised nanomaterials were found effective to disrupt biofilm of S. aureus and P. aeruginosa. Interestingly, encapsulated CeO₂ ‐NPs revealed powerful antibacterial and biofilm disruption activity examined by fluorescent live/dead staining using confocal laser scanning microscopy. The superior antibacterial activities exposed by encapsulated CeO₂ ‐NPs lead to the conclusion that they could be useful for controlling biofilm producing multidrug resistance pathogens.Inspec keywords: particle size, microorganisms, organic compounds, nanomedicine, sol‐gel processing, cellular biophysics, scanning electron microscopy, optical microscopy, nanoparticles, antibacterial activity, fluorescence, biomedical materials, nanofabrication, X‐ray diffraction, chromatography, filled polymers, cerium compoundsOther keywords: microbial biofilms, aqueous root extract, sol–gel method, gas chromatography‐mass spectrometer, 1‐di‐ethoxy, 1‐Butanol, nanomaterial synthesis, mean particle size, antibacterial activities, ethanol, acetone, 1‐ propanol, biocompatible ceria‐nanoparticle encapsulation, nano‐chitosan, Arctium lappa l., oleic acid, erythrocyte integrity, spectrophotometer measurement, haemoglobin release, mono dispersed beads shaped particle formation, X‐ray diffractometry, cubic crystalline structure, fluorescent live/dead staining, confocal laser scanning microscopy, multidrug resistance pathogens, size 26.2 nm, size 28.0 nm, size 48.8 nm, size 22.6 nm, CeO₂      

Particles in silicon deposition discharges

The causes of particle growth in silane discharges, and of their escape to growing devices, are discussed. The relation between particle densities, sizes, and escape to the electrodes in an experimental reactor versus those expected (versus location) in large device-production reactors are explained. Available particle growth, density, and escape data is briefly reviewed and explained. In particular, the important distinction between particles drifting with the gas flow and those trapped at the downstream edge of the plasma is clarified. The very important role of thermophoretic forces is discussed, particularly its influence on the size of particles that incorporate into devices. Methods are suggested to mitigate particle incorporation into devices, and to prevent major particle buildup at the downstream end of a reactor.     

Selective sexual orientation-related differences in object location memory.

The present study examined sexual orientation-related differences in object location memory by using 3 object arrays (testing object exchange, object shift, and novel objects conditions) and 1 metric positional memory array. Heterosexual women and homosexual men significantly outperformed heterosexual men in all 3 object arrays. However, there were no group differences in metric positional memory. Heterosexual males expectedly outperformed the other groups in spatial perception (Judgment of Line Orientation; A. L. Benton, K. D. Hamsher, N. R. Varney, & O. Spreen, 1983). Regression modeling revealed that sexual orientation and spatial perception predicted object exchange performance, whereas recalled childhood gender nonconformity, a robust developmental marker of adult sexual orientation, predicted object shift and novel object performance alone. A measure ascribed to the actions of prenatal androgens, the 2nd to 4th finger length ratio, did not predict object location memory. These data may limit possible developmental pathways for sexual variation in selective forms of spatial memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pleurotus mushrooms. Part III. Biotransformations of natural lignocellulosic wastes: commercial applications and implications

Species of Pleurotus are endowed with the capacity to degrade unfermented natural lignino-cellulosic wastes. From the time the substrate is spawned until the end of cropping, there occurs a spectrum of qualitative and quantitative changes in the various substrate constituents, viz., cellulose, hemicellulose, lignin, sugars, amino acids, phenols, ash, nitrogen, etc. In general, cellulose, hemicellulose, and lignin are degraded, solubility of the substrate is increased, phenolic content is decreased, sugar and amino acid contents are increased, as is the ash content due to a constant utilization of the organic matter. The ability of Pleurotus to effect these degradative changes is discussed under both sterile (monoculture) and nonsterile culturing conditions. The enzymatic aspects affecting these various chemical changes in the lignino-cellulosic substrates are brought out. The various commercial applications and implications of the spent substrate, such as use as an upgraded form of ruminant feed, production of biogas, manufacture of paper/cardboard, recycling into Agaricus compost, garden fertilizer, production of single cell proteins, etc., are critically evaluated.