Tempered martensite embrittlement in phosphorus doped steels

In this paper the effect of phosphorus on tempered martensite embrittlement of Ni−Cr steels is reported. It is shown that the measured degree of embrittlement depends on the phosphorus concentration, test temperature, grain size, and austenitizing temperature. Although reducing the prior austenite grain size tends to reduce the observed embrittlement, this can be offset by the fact that the low austenitizing temperatures used to produce the fine grain size cause an increased amount of impurity segregation. It is further shown that bulk phosphorus concentrations below 100 wppm may be required to avoid embrittlement of this type in ultra-high strength steels.     

Chemical composition of acacia seeds

Several plants of Acacieae (family Leguminosae) have been recommended under aforestation programs. The seeds of some such plants have been examined for their fatty acid composition with special reference to epoxy acids. Epoxy 18:1 in Acacia auriculiformis, A. catechu, A. coriacea and A. mellifera was 4.9, 0.1, 2.1, and 0.6%,respectively.     

Butter from Plants

There is a likelihood of food shortage becoming acute in developing countries and people will have to depend increasingly on plants rather than animals for their dietary requirements. To meet the growing demand of fat which have texture like butter because of the higher percentage of saturated fatty acids, little known or neglected plants could be investigated. The paper reviews the work so far done on such aspect and highlights the plants which could be taken up for systematic plantation.     

Incorporation oftrans fatty acids into submandibular salivary gland lipids

Three groups of rats were fed diets containing 20% corn oil, 20% margarine stock (MS) or 19% MS +1% corn oil. Diets were fed for 12 weeks, 1 week of pregnancy, 3 weeks of lactation and 8 weeks post-weaning. The incorporation oftrans-octadecenoate into various lipids of the submandibular salivary gland (SMSG) homogenates and plasma membranes was studied.Trans octadecenoate was incorporated into all the lipid fractions studied. Its levels were the highest in phosphatidylethanolamine. The double bond index of phospholipid fatty acids in the plasma membranes of the SMSG was substantially lower in the group fed 20% MS. The fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) was generally higher in the membranes of SMSG from rats fed MS than that of the other two groups, thus indicating lower fluidity. Also, the breakpoints in fluorescence polarization were at a higher temperature in the membranes from rats fed MS as compared with those fed corn oil. Lower fluidity of plasma membranes of SMSG observed in rats fed 20% MS may result in modification of the activities of membrane-bound enzymes. Part of this work was presented at the Federation of American Societies for Experimental Biology (FASEB) 68th Annual Meeting, St. Louis, Missouri, April 1984. Alam, S.Q., Alam, B.S., and Banerji, A. Fed. proc. 43,317 (1984).     

Core/shell nanoassembly of amphiphilic naproxen‐polyethylene glycol: synthesis,characterisation and evaluation as drug delivery system

Small molecule‐based amphiphiles self‐assemble into nanostructures (micelles) in aqueous medium which are currently being explored as novel drug delivery systems. Here, naproxen‐polyethylene glycol (N‐PEG), a small molecule‐derived amphiphile, has been synthesised, characterised and evaluated as hydrophobic drug carrier. ¹ H, ¹³ C Nuclear magnetic resonance (NMR), mass spectrometry (MS) and Fourier‐transform infrared spectroscopy (FTIR) confirmed the formation of N‐PEG and dynamic light scattering (DLS) revealed the formation of nano‐sized structures of ∼228 nm. Transmission electron microscope (TEM) analysis showed aggregation behaviour of the structures with average size of ∼230 nm. Biodegradability aspect of the micellar‐structured N‐PEG was demonstrated by lipase‐mediated degradation studies using DLS and TEM. High encapsulation efficiency followed by release in a sustained manner of a well‐known anticancer drug, doxorubicin, demonstrated the feasibility of the new drug delivery system. These results advocate the promising potential of N‐PEG micelles as efficient drug delivery system for specific delivery to cancerous cells in vitro and in vivo.Inspec keywords: cancer, biodegradable materials, cellular biophysics, encapsulation, biomedical materials, drugs, nanofabrication, drug delivery systems, nanomedicine, self‐assembly, nanoparticles, transmission electron microscopy, colloids, molecular biophysics, light scattering, hydrophobicity, biochemistry, enzymes, core‐shell nanostructures, nanocomposites, proton magnetic resonance, Fourier transform infrared spectra, mass spectroscopic chemical analysisOther keywords: hydrophobic drug carrier, nanosized structures, transmission electron microscope analysis, doxorubicin, N‐PEG micelles, core/shell nanoassembly, amphiphilic naproxen‐polyethylene glycol, drug delivery system, small molecule‐based amphiphiles self‐assemble, small molecule‐derived amphiphile, ¹ H NMR, ¹³ C NMR, MS, FTIR, dynamic light scattering, aggregation behaviour, biodegradability aspect, lipase‐mediated degradation studies, encapsulation efficiency, cancerous cells     

Study on Ambient Air Quality of Megacity Delhi,India During Odd–Even Strategy

State Government of Delhi had adopted odd–even scheme on vehicles plying in megacity Delhi to understand and improve the air quality of Delhi. To understand the effect of odd–even scheme on the concentration of pollutants, we have analysed the concentrations of chemical constituents [organic carbon, elemental carbon, water soluble inorganic components, trace elements and stable carbon and nitrogen isotopic composition (δ¹³C_TC) and N (δ¹⁵N_TN)] of PM_2.5 and PM₁₀ along with mixing ratios of trace gases (NO _x , CO, SO₂ and NH₃) data collected at an urban site of megacity Delhi during first phase (Phase-I: winter 2016) and second phase (Phase-II: summer 2016). During the Phase-I of the scheme, mass concentrations of PM_2.5 and PM₁₀ were changed by ?13 and ?5%, respectively, whereas, concentrations of PM_2.5 and PM₁₀ were changed by +18 and +16%, respectively during the Phase-II as compared to before the implementation of the scheme. The analysis of chemical constituents of PM_2.5 and PM₁₀ reveals that the odd–even strategy marginally changed the concentrations (markers) of vehicular emission. During both the phases, mixing ratios of trace gases (NO _x , CO, SO₂ and NH₃) were reduced non-significantly during the odd–even scheme as compared to before the implementation of the scheme.     

Performance Evaluation of Aerated Lagoon in Summer and Winter Conditions

A 1-year study evaluated the performance of a full-scale aerated lagoon, located in a midwest community in the United States. The objective of this study was to evaluate the performance of the lagoon under varied temperature conditions. The main parameters for evaluation were 5-day biochemical oxygen demand, total suspended solids, and ammonia-N. In addition, phosphorus and bacteriological qualities of the effluent were investigated. In general, the facility met 5-day biochemical oxygen demand and suspended solids limits required by the National Pollutant Discharge Elimination System. The lagoon reduced the ammonia-N concentration efficiently during late spring, summer, and fall, with values ranging from 0.3 to 4.2 mg∕L. In the winter period the activities of the nitrifying bacteria diminished, resulting in a reduced nitrification rate. The ammonia-N during winter ranged from 8.8 to 23 mg∕L. During the spring months (March to May) the nitrification rate slowly increased with the rise in temperature. This reflects the time period and environment necessary to reach an effective nitrification population in the system. The adjustment period was reversed in the fall months with a declining population of nitrifiers and decreased nitrification rates. The effluent total phosphate levels ranged from 0.6 to 4.9 mg∕L. Effluent fecal coliform values ranged from 10 to 1,110∕100 mL.     

Excited State Dynamics of a Self‐Doped Conjugated Polyelectrolyte

The growing number of applications of doped organic semiconductors drives the development of highly conductive and stable materials. Lack of understanding about the formation and properties of mobile charges limits the ability to improve material design. Thus the largely unexplored photophysics of doped systems are addressed here to gain insights about the characteristics of doping‐induced polarons and their interactions with their surroundings. The study of the ultrafast optical processes in a self‐doped conjugated polyelectrolyte reveals that polarons not only affect their environment via Coulomb effects but also strongly couple electronically to nearby neutral sites. This is unambiguously demonstrated by the simultaneous depletion of both the neutral and polaronic transitions, as well as by correlated excited state dynamics, when either transition is targeted during ultrafast experiments. The results contrast with the conventional picture of localized intragap polaron states but agree with revised models for the optical transitions in doped organic materials, which predict a common ground level for polarons and neighboring neutral sites. Such delocalization of polarons into the frontier transport levels of their surroundings could enhance the electronic connectivity between doped and undoped sites, contributing to the formation of conductive charges.