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The comparative efficacy of 0.4% carboxymethyl cellulose (CMC) and 0.3% sodium alginate (SA) was evaluated as fat replacer in low-fat (

Short crack propagation under cyclic loading is compared experimentally in hydrogen charged and un-charged SA508 Gr. 3 Cl. I low alloy steel (LAS). This LAS is used in manufacturing of pressure vessels installed in nuclear power plants and is susceptible to hydrogen embrittlement (HE) during operation. Single edge notch tension (SENT) specimens with an initial notch of 85 μm–90 μm are used for this short fatigue crack propagation study. The short crack growth from the notch of SENT specimen subjected to cyclic loading is measured using moving digital microscope fitted on the servo-hydraulic fatigue testing machine. The short fatigue crack growth rate in hydrogen charged SA508 Gr. 3 Cl. I LAS is found to be one order higher as compared to the un-charged subject reactor pressure vessel (RPV) steel. Both trans-granular and inter-granular crack propagation is observed in un-charged and hydrogen charged specimens. In un-charged specimens, inter-granular crack propagation along the prior austenite grain boundaries (PAGBs) occurred only when the short fatigue crack encounters the martensite/austenite (M/A) island present along the PAGB. Whereas, in hydrogen charged specimens, inter-granular crack propagation occurred along the PAGBs of large size prior austenite grains and trans-granular crack propagation through the small size prior austenite grains. Strong resistance to short fatigue crack propagation is provided by PAGBs in un-charged specimens whereas, these PAGBs offered negligible resistance to short fatigue crack growth in hydrogen charged subject RPV steel. A new perspective of studying HE in materials by conducting short fatigue crack growth experiments is demonstrated.

Sensitization is precipitation of chromium carbide in stainless steels during exposure to high temperatures service that leads to premature corrosion failure of components. It is well known that during sensitization process, chromium carbide forms at the grain boundary along with chromium depletion near the grain boundary resulting in the change of the magnetic property of the steel from paramagnetic to ferromagnetic. From this study, it is clear that the magnetic characterisation is sensitive enough to detect the sensitisation. However, the magnetic behavior has contributions from both ferromagnetic and super paramagnetic nature of the phase.

The effect of hydrogen on short crack propagation under cyclic loading in SA508 Grade 3 Class I low alloy steel is investigated. This low alloy steel is used in manufacturing of pressure vessel installed in Indian nuclear power plants. During operation these pressure vessels are subjected to continuous supply of pressurized hot water at 600 K and hence are susceptible to hydrogen embrittlement. In past, research has been conducted on the effect of hydrogen embrittlement on long fatigue crack propagation in this material but, the mechanistic understanding and correlation of hydrogen embrittlement with microstructural features in the material can be understood well by studying the effect of hydrogen embrittlement on short fatigue crack propagation. Short fatigue cracks are of the order of 10 µm to 1 mm and unlike long cracks these short cracks strongly interact with the microstructural features in the material such as grain/phase boundaries. The effect of hydrogen embrittlement on short crack propagation is studied by artificial hydrogen charging of the material through electrochemical process. The single edge notch tension (SENT) specimens with an initial notch of the order of 85 to 90 µm are used to study the short crack propagation. The short cracks in hydrogen charged samples initiated from the notch at lower number of loading cycles as compared to the uncharged notched samples for the same value of applied stress range (Δσ). After initiation, the short fatigue crack in hydrogen charged samples propagated at higher rate as compared to uncharged samples. This dissimilarity in crack propagation behavior is due to the difference in the interaction of short fatigue crack with the microstructural features for a hydrogen charged and uncharged samples.

The present investigation was carried out during 2012-13 with twelve Pea ( Pisum sativum L.) cultivar for protein profiling through SDS-PAGE in The department of Genetics and Plant Breeding, CSA University of Agriculture and Technology, Kanpur (U.P). The Seed protein profiles of pea cultivars were studied by extracting the total proteins from five single seeds in each cultivar and performed SDS-Polyacrylamide gel electrophoresis. All the cultivars were clearly revealed remarkable polymorphism from their protein banding patterns. On the basis of banding patterns through SDS-PAGE, indicated that the number of bands found in cultivars ranged from 12 to 19 with Rm value 0.12 to 0.9. The results found that, the cultivar KPMR-400 had recorded highest number of bands (19) whereas, the minimum number of bands (12) observed in three cultivars viz., KPMR-921, KPMR-902 and KPMR-913. The total seed protein variation were also analyzed using Un-weighted Pair Group Method with Arithmetic Mean (UPGMA) and resultant cluster analysis based on the data of protein profiling, classified twelve cultivars into six major groups. The finally study concluded that, the protein variability analysis clearly showed that there was sufficient genetic divergence among these cultivars of pea with respect to seed storage protein. Among all the cultivars, the KPMR-906 in cluster IV having wider genetic diversity and suggested to utilize in future crop improvement program.

The 197Au(n, γ)198Au reaction cross-sections at the neutron energies of 1.12, 2.12, 3.12 and 4.12 MeV were determined by using activation and off-line γ-ray spectrometric technique. The mono-energetic neutron energies of 1.12–4.12 MeV were generated from the 7Li(p, n) reaction by using the proton energies of 3 and 4 MeV from the folded tandem ion beam accelerator (FOTIA) at BARC as well as 5 and 6 MeV from the Pelletron facility at TIFR, Mumbai. The 115In(n,γ)116mIn reaction cross-section was used as the neutron flux monitor. The 197Au(n, γ)198Au reaction cross-section at the neutron energies of 3.12 and 4.12 MeV are reported for the first time. The 197Au(n, γ)198Au reaction cross-sections at 1.12 and 2.12 MeV are close to the literature data of in between neutron energies. The 197Au(n, γ)198Au cross-section was also calculated theoretically by using the computer code TALYS 1.6 and found to be higher than the experimental data of present work and literature data within the neutron energies of 0.8 to 4 MeV.

The 151Eu(n,γ)152m1Eu reaction cross-section at the neutron energies (E n ) of 1.12, 2.12, 3.12 and 4.12 MeV was determined by using activation and off-line γ-ray spectrometric technique. The mono-energetic neutrons of 1.12–4.12 MeV were generated from the 7Li(p,n) reaction by using the proton beam energies of 3–6 MeV. The 197Au(n,γ)198Au reaction cross-section was used as the neutron flux monitor. The 151Eu(n,γ)152m1Eu reaction cross-section was also calculated by using computer code TALYS 1.6 and compared with the experimental data to check its validity. The Eu(n,γ) reaction cross-section is important for the safety of the fast reactor and conventional fission reactor.

A new lumped-parameter equivalent circuit model using three-diodes is presented in this work for large area (∼154.8 cm 2 ) industrial silicon solar cells. The estimation of values of ideality factors n 1 (>1) and n 2 (>2) using a Particle Swarm Optimization (PSO) algorithm for the two-diode model of the industrial samples has been found not to be in conformity with the theoretical values (n 1 = 1 and n 2 = 2 in the literature). The two diodes of the two-diode model are not able to define the different current components of the solar cells clearly. A model with three-diodes has been proposed to better explain the experimental data. In the proposed model, we considered the series resistance, R s , of the solar cell to vary with the current flowing through the solar cell device. All the parameters of the proposed model have been estimated using a PSO algorithm and they were compared with the parameters of the two-diode model. The new model has been found to be a better model to define clearly the different current components of the large size industrial silicon solar cells.

Tri-level resistive switching behavior was observed in an Al2 O3/SiO2 gate stack with Ru metal nanocrystals embedded in the Al2O3 layer. The device was successfully switched among three resistance states (high, medium, and low) after a forming process using a simple electrical method. The resistance ratio of the high-resistance state to the low-resistance state is more than 103. The insulator-to-conductor (and vice versa) transition of the Al2O3 and SiO2 dielectric layers is elucidated by a physical model, which invokes oxygen ion (O2-) trapping/detrapping at the metal-oxide interfaces, as well as O2- transport and annihilation with the oxygen vacancies in the breakdown percolation path. The switching transition of each individual dielectric layer is found to be dependent on the polarity of the gate bias. This new understanding opens the prospect of metal-nanocrystal-based Al2O3/SiO2 gate stacks for a resistive switching memory application.

The effects of concentrations of methyl ethyl ketone peroxide (MEKP) on the gelation characteristics and the shrinkage properties of solventless polyester varnishes were studied. Activation energies for gelation at different concentrations (0.75, 1.0, 1.5, 2.0, 2.5, 3.0 and 5.0 phr) of MEKP were 56.2, 54.3, 53.9, 51.5, 49.4, 44.0, and 41.6 kJ/mole, respectively. The mechanism of gelation and the kinetic rate equation are proposed to define the possible reasons for the variation of the above-mentioned varnish properties in the presence of the catalyst.

A hybrid approach of forming a stabilizing layer of bonded carbon on porous silicon (PSi) surface by photoassisted reaction of acetylene gas at low temperatures is described. The PSi samples were made by anodization in a HF/H 2 O 2 electrolyte at a current density of 80 mA/cm 2 . Samples show a strong luminescence with a peak at 644±4 nm. The photoluminescence (PL) intensity shows a very strong quenching under the influence of continuous laser illumination (∼0.25 W/cm 2 , 488 nm). The PSi samples were subjected to flowing acetylene under optical illumination from quartz halogen lamp (20 mW/cm 2 ). The PL intensity is initially quenched to very low values (less than 5% of initial value) and then recovers on further exposure to acetylene to a final value ∼30% of the initial value. No quenching is observed on further exposure to laser illumination in ambient air instead an improvement of 15–25% in PL intensity is observed. This behaviour is a good indicator of the formation of a practically stable PSi surface.

The effect of cinnamic acid on in vivo nitrate reductase activity and protein content in cucumber cotyledons was studied. Cinnamate increased in vivo nitrate reductase activity and also the total protein content at lower concentrations (0.01–0.1 mM). Higher concentration, however, proved inhibitory. The effect of cinnamate on nitrate reductase activity has been discussed.

The time dependence of organ distribution and excretion of intravenously (iv) injected 210Po was investigated after the single or repeated administration of N,N'-diethylamine-N-carbodithioate (diethyldithiocarbamate, DDTC) and three bis-dithiocarbamates: N,N'-dimethylethylenediamine-N,N'-biscarbodithioate (MeTTC), N,N'-diethylethylenediamine-N,N'-biscarbodithioate (EtTTC), and N,N'-di)20hydroxyethyl)ethylenediamine-N,N'-biscarbodithioate++ + (HOEtTTC). The biokinetics of iv injected 210Po was used as a model for the behaviour of 210Po absorbed into the blood from any other site of entry into the body. The most effective chelating agent was HOEtTTC, which was not only effective when injected subcutaneously (sc) immediately after 210Po, but also 1 h later. Toxic effects of DDTC were observed in a metabolic study when the effect of HOEtTTC was compared with that of DDTC. DDTC caused accumulation of 210Po in brain and transiently in liver. When HOEtTTC was administered, the faecal excretion of 210Po was increased from the very beginning. MeTTC, EtTTC and N-(2,3-dimercaptopropyl)phtalamidic acid (DMPA) were ineffective when the treatment started 1 h after iv injection of 210Po.

Data on daily nitrogen intake (X) and faecal nitrogen (Y) excretion both expressed as g/100 g of DM consumed were collected from long and short range 4 experiments covering 9 nitrogen balance trials conducted at varied intervals on 3 groups each of 8 non-producing adult male buffaloes. In each experiment, the 3 groups were offered 3 levels of digestible crude protein (DCP) which covered 0.60, 0.50, 0.45, 0.40, 0.35, 0.30 and 0.25 kg DCP/100 kg BW/d intakes through rapeseed cake and wheat straw during these 4 experiments. The data comprising 27 pairs of group-means pertaining to X and Y revealed a close positive correlation (r = 0.628; t significant at P

We present a systematic investigation of the temperature dependent relaxation current behavior for single layer and dual layer Pt metal nanocrystal (MNC)-based Al2O3/SiO2 flash memory gate stacks. Stacks containing single layer Pt MNC exhibit a dual-slope behavior in the log-log plots of the relaxation transient, whereas those with dual layer Pt MNC exhibit a single-slope behavior. We propose a physical model embodying two competing relaxation mechanisms to explain the Pt MNC induced relaxation current-thermionic emission and the quantum tunneling. Based on this model, the dual-slope behavior of single layer MNC-based gate stack can be ascribed to the dominance of thermionic emission at the initial part and quantum tunneling at the tail part. In contrast, the single slope behavior of the dual layer metal nanocrystal-based stack arises from the dominance of the quantum tunneling throughout the relaxation. In addition, we verify that stacks containing dual layer MNC show better retention property than their single layer counterparts. Our results demonstrate that relaxation current measurements offer a simple way to assess the charge retention capability for MNC-based gate stacks. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4764873]

By comparing the relaxation current with pure Al 2 O 3 layer, we postulate that the relaxation process of the dual layer Pt nanocrystal-based Al 2 O 3 /SiO 2 stack mainly arise from the charge leak of the metal nanocrystals, which probably follows the Poole-Frankel behavior. The extracted relaxation current from the metal nanocrystals and its charge leak time constant provide a simple and effective characterization tool to detect the retention property of this Flash memory cell.

Summary The effect of varying nitrate levels (0—20 mM) was studied on the relative growth rate (RGR), acetylene reduction activity (ARA), nitrate uptake and nitrate reductase (NR) activity of A. caroliniana and A. pinnata . In both Azolla species, RGR was higher with 5 mM nitrate as compared to N-free medium whereas higher concentration of nitrate reduced the RGR. The significant inhibition of ARA was observed on 16th day after incubation with 5 mM nitrate, 12th day with 10 mM, 8th day with 15 mM and 4th day with 20 mM. The increasing nitrate levels resulted in increased nitrate uptake and NR activity in both the species. A. caroliniana recorded higher RGR and ARA whereas nitrate uptake and NR activity were higher in A. pinnata .

Amino acid-analogue-resistant mutants of the cyanobacterium Spirulina platensis were isolated using amino acid analogues β-2-thienylalanine, p-fluorophenylalanine, ethionine and azetidine-2-carboxylic acid. The growth and other cellular contents in these mutants were less than in the parent. The internal free amino acid pool showed varying amounts. Maximal overproduction occurred of proline whereas overproduction of aspartic acid, alanine and lysine was much less.

Modeling of recombination velocity of minority carriers at the p-p/sup +/ low-high junction end of the p-base region of n/sup +/-p-p/sup +/ silicon diodes is carried out by taking the minority-carrier recombination effects in the space-charge region (SCR) of the low-high (L-H) junction into account. Solving Poisson's equation in the SCR numerically revealed that the SCR is composed of an accumulation layer on the p side and a depletion layer on the p/sup +/ side. Generally, the depletion layer is very thin as compared with the accumulation layer, and the built-in potential across the depletion layer never exceeds the thermal voltage, i.e. kT/q. Further, the minority-carrier recombination in this layer is also insignificant. For most L-H junction-based silicon devices, in practice, the minority-carrier recombination in the accumulation layer controls the value of the effective minority-carrier recombination velocity (S/sub eff/) at the back surface of the p-base region and the influence of the recombination in the heavily doped p/sup +/ region is less significant. >

The performance and reliability of charge trap flash with single and bi-layer Si-rich and N-rich nitride as the storage node is studied. Single layer devices show lower memory window and poor cycling endurance, and the underlying physical mechanisms for these issues are explained. An engineered trap layer consisting of Si-rich and N-rich nitride interfaced by a SiON barrier layer is proposed. The effect of varying the SiON interfacial layer position on memory window and reliability is investigated. Optimum bi-layer device shows higher memory window and negligible degradation due to cycling (at higher memory window) compared to single layer films. The role of SiON interface in improving the performance and reliability of bi-layer stacks is explained.

In this work we present an extensive reliability and performance evaluation of tungsten dot nanocrystal (NC) devices under NAND mode of operation. Improvement in performance and reliability was observed with scaling W and L. The use of better high-k processing is proposed to improve the reliability. We also propose a numerical simulation model for NC memory devices using transient capacitive charging model. The approach is very generic and computationally less extensive than the previous works.

This paper for the first time, reports the memory enhancement characteristics and good retention with feasibility of two-bit operation of small scale devices with gate length down to 100 nm, using double layer W nanocrystals embedded in HfAlO for the next generation memory application. Double layer device shows increasing memory window with scaling which will be extremely beneficial

The effectiveness of newly synthesised thiol chelating agents has been studied to reduce 210 Po in organs and tissues of rats. From four derivatives of meso-2,3-dimercaptosuccinic acid (DMSA) only the ethoxyethyl diester (DEEDMS) was efficient in decreasing total activity in the analysed tissues (to 80% of control animals) when repeated subcutaneous treatment started 1 h after intravenous injection of 210 Po. The most pronounced effect was achieved with three derivatives of dithiocarbamate: N,N'-dimethyl-(MeTTC), N,N'-diethyl-(EtTrC), N,N'-di(2-hydroxyethyl)ethylenediamine-N,N'-bisdithiocarbamate (HOEtTTC). When treatment started immediately after 210 Po administration, the total content of 210 Po in analysed tissues was reduced to 74-41% of control values

To reduce retention and toxicity of the alpha particle emitter polonium-210 in rats by newly developed chelating agents.Repeated subcutaneous chelation was conducted after intravenous injection of 210Po nitrate. For reduction of 210Po retention the treatment with vicinal dithiols meso-and rac-2,3-dimercaptosuccinic acid (DMSA), mono-i-amylmeso-2,3-dimercapto succinate (Mi-ADMS) and mono-N-(i-butyl)-meso-2,3-dimercapto succinamide (Mi-BDMA) were used. For the reduction of toxic effects of 210Po, treatment effectiveness of Mi-BDMA was compared with that of N,N'-di(2-hydroxyethyl)ethylenediamine-N,N'-biscarbodithioate (HOEtTTC, reference compound).Treatment with meso-DMSA and rac-DMSA altered the main excretion route of 210Po, reduced its contents in the liver but increased its deposition in the kidneys. Treatment with Mi-ADMS or Mi-BDMA increased total excretion of 210Po, mainly via the faeces. Only Mi-BDMA decreased 210Po levels in the kidneys. The effectiveness of all chelators decreased with delay in the start of treatment. In a survival study, the lives of rats treated early with Mi-BDMA or delayed with HOEtTTC were prolonged three-fold when compared with rats receiving a lethal amount of 210Po only.Of the vicinal dithiols examined, Mi-BDMA was the best mobilizing chelating agent for 210Po and it reduced 210Po toxicity when the treatment started immediately. However, the detoxification efficacy of the immediate treatment with HOEtTTC, observed in our previous study, was superior to that of the present result with Mi-BDMA.

The protective effect of N,N'-di(2-hydroxyethyl)ethylene-diamine-N,N'-biscarbodithioate (HOEtTTC) against the subacute lethal radiotoxicity of polonium-210 was investigated in a survival study and by histopathological and haematological examinations of some organs and tissues in Sprague-Dawley rats. This effect was compared with that of N,N'-diethylamine-N-carbodithioate (diethy dithiocarbamate, DDTC). In the survival study, rats injected in intravenously solely with a lethal amount of 210Po (1.45 MBq kg-1 body mass) died within 14-44 days while 90% of rats treated with HOEtTTC survived for 5 months until sacrificed. When treated with DDTC all rats died within 36-93 days. In the histopathological examination, relevant changes resulting from incorporation of 210Po were found in lymph nodes, thymus and humeral bone marrow. After the treatment with HOEtTTC no pathological changes were observed. In the haematological examination, severe reduction in blood and femoral bone marrow (BM) cell counts was revealed in rats injected with 210Po. This reduction was reversed by treatment with HOEtTTC. Treatment with DDTC led only to partial recovery of blood and BM cell count. In conclusion, under the conditions of the experiment only HOEtTTC was fully effective in reducing subacute lethal radiotoxicity of 210Po.

Contaminated puncture wounds were simulated in rat by intramuscular injection of 210Po. The aim of the study was to determine the effectiveness of chelation treatment as a function of time, dosage, and route of chelate administration. Ten newly synthesized substances containing vicinal sulphydryl and carbodithioate groups were used and their effect was compared with that of chelators clinically applicable in man--BAL (2,3-dimercaptopropane-1-ol), DMPS (2,3-dimercaptopropane-1-sulphonate), DMSA (meso-2,3-dimercaptosuccinic acid), and DDTC (sodium diethylamine-N-carbodithioate). The results indicate first that complete removal of 210Po from the injection site is achieved by only two local injections of DMPS, beginning as late as 2 h after injection of 210Po. Second, many of the substances used merely induce translocation of 210Po from the injection site into other tissues. Third, a combined local treatment at the injection site with DMPS plus repeated systemic, subcutaneous, treatments with HOEtTTC (N,N'-di-(2-hydroxyethyl)ethylenediamine-N,N-biscarbodithioate), a derivative of DDTC, results after 2 weeks in a reduction of the estimated total body retention of 210Po to about one-third of that in untreated controls. In the latter case the cumulative excretion of 210Po increased from 8 to 54%, mainly via the faeces.

Nine different sulphur-based chelators, including dithiols and dithiocarbamates, were examined for their ability to remove Po-210 from the rat. In general, treatments merely caused a redistribution of Po-210 in the body. Greatest reduction of Po-210 in blood was achieved by 2,3-dimercaptopropanol (BAL), sodium diethyldithiocarbamate (DDTC), and N-(2,3-dimercaptopropyl) phthalamidic acid (DMPA). Nearly all the compounds tested decreased Po-210 in the spleen and muscle. On the other hand, BAL and DDTC substantially increased the accumulation of Po-210 in the brain while DMPA, DMPS (sodium 2,3-dimercaptopropane-1-sulphonate) and DMSA (meso-2,3-dimercaptosuccinic acid) increased by several times the Po-210 in kidneys. A less pronounced increase of Po-210 was sometimes observed in liver (due to DDTC and DMPA) and in muscle (due to BAL and DDTC). Three of the dithiocarbamates (BGDTC, MeOBGDTC and BLDTC) did not increase accumulation of Po-210 in the brain and muscle but they reduced Po-210 in blood to a lesser degree than DDTC. A derivative of DMSA (Mi-ADMS) reduced Po-210 in blood, bone and muscle more than DMSA, but at the same time increased Po-210 in the kidney. When BAL or DDTC were combined with other agents there was a greater reduction in the whole-body burden of Po-210. Removal of Po-210 from the bone, spleen and kidneys by BAL was increased by repeated treatment. However, under similar experimental conditions the effect of a single injection of BAL on Po-210 in blood was less pronounced when the period of observation was prolonged. Total-body retention of Po-210 could not be reduced to less than 85% of the untreated controls by any of the chelators tested. In spite of this some of them (BAL, DMPS, DMSA, DMPA) could still have a useful role in reducing the toxicity of Po-210.

Parallel plate capacitors for the broadband dielectric characterisation of both high (amorphous BaTiO3 and amorphous TaOx) and low (parylene) dielectric constant thin films were fabricated at low temperature (< 200 °C). The dielectric constant and loss tangent were dermined through the measurement of C, G and the S parameters of the capacitors. These thin film dielectrics exhibit no dispersion in the frequency range 1 kHz – 40 GHz.

Boron trifluoride diacetic acid, when reacted with semicarbazones or thiosemicarbazones yields products of the type, FB(SCZ) and FB(TSCZ). Another series of complexes has been obtained by the reaction of boron triacetate with the same ligands, of general formulae, (AcO)B(SCZ) and (AcO)B(TSCZ). All are monomers in freezing dioxane and non-electrolytes in dry dimethylformamide. Some IR, 1H NMR, and 19F NMR data have also been recorded.

A set of experiments is described in which CO/sub 2/ is injected into large cores of CH/sub 4//sup -/ and water-saturated bituminous coal at elevated pressures. CO/sub 2/ at pressures up to 800 psig (5516 KPa) is used to simulate the enhanced recovery of in-situ CH/sub 4/ from coal beds. CO/sub 2/ injection increases the recovery of CH/sub 4/ by a factor of two to three times that achieved in simple desorption by pressure drawdown and atmospheric diffusion. In general, higher CO/sub 2/ pressures achieve greater CH/sub 4/ recovery. The presence of even small amounts of N/sub 2/ in the injection gas greatly reduces the CH/sub 4/ recovered. CO/sub 2/ at 500 to 800 psig (3447 to 5516 kPa) is shown to be capable of completely demethanating integral coal samples. This was confirmed by tests run on crushed cores. CO/sub 2/ consumption by permanent adsorption is quite high vis-a-vis the CH/sub 4/ recovered and may preclude its use as an enhanced-recovery energy process. Its primary function would appear to be as a means of safely demethanating coal beds before mining.

Effect of single superphosphate, urea, ammonium sulphate, potassium sulphate and animal dung on the formation of sporocarps inAzolla pinnata under the field conditions is studied. Of the 4 strains (India, Thailand, Vietnam and Bangladesh), the Bangladesh strain produced maximum number of sporocarps (mega+micro); the Vietnam strain developed maximum number of microsporocarps, but no megasporocarps. Animal dung at 1·0 t/ha enhances sporocarp formation. Phosphorus deficiency enhances formation of megasporocarps, while superphosphate decreases their number. Ammonium sulphate or urea at 30 kg N/ha increases the number of microsporocarps, while potassium sulphate increases their number irrespective of the rate of application.

Freshly-harvested blue-green algae (20 t ha −1 ) or Azolla (20 t ha −1 ) were incorporated into a waterlogged rice soil and changes of redox-potential and the availability of nitrogen and phosphorus were measured periodically. The soil progressively became reduced where blue-green algae or Azolla had been incorporated. The rate of N release from Azolla was more rapid than from blue-green algae and the amounts released after 7–35 days of flooding were between 41 and 76% and 12 and 35% respectively. Increased P availability was also recorded in soil following the incorporation of blue-green algae or Azolla and reached highest values after 21 days incubation.

Summary The nitrogenase activity (acetylene reduction activity) and chlorophyll content of Azolla pinnata R. Br. strains from India, Thailand, Vietnam, Bangladesh were examined in fallow flooded rice fields at 7, 12, 17 h of the day in April (Summer), July (Rainy) and January (Winter) months at C. R. R.I., Cuttack, India. All the strains showed maximum nitrogenase activity at 12 h of the day although the differences in chlorophyll at 7, 12, and 17 h were insignificant. The enzyme activity was maximum in the month of April when light incidence and temperature were also maximum but the amount of chlorophyll was more in July than other months. The Bangladesh strain showed significantly higher nitrogenase activity and activity was ranked in the order of Bangladesh > Thailand > Vietnam > India strains.The Thailand strain was superior to others in chlorophyll content.

Summary The effect of nitrogen fertilizers ammonium sulphate (825 mg pot −1 ) and urea (395 mg pot −1 ) corresponding to 40 kg N ha −1 was studied on acetylene reduction activity (ARA) and heterocyst frequency (HF) in the cyanobacterium Anabaena azollae occurring in successive leaves of Azolla caroliniana Willdenow , Azolla microphylla Kaulfuss , Azolla filiculoides Lamark , Azolla mexicana Presl ., Azolla nilotica Decaisne , Azolla rubra R. Brown and Azolla pinnata R. Brown (the last from both Malaysia and India) grown on flooded soil in pots under net house conditions. Both HF and ARA increased from first leaf (shoot apex) to the last one (before branch) in all the species, although these were highest with no nitrogen treatment followed by that with ammonium sulphate and urea treatments. The two nitrogen fertilizers had little effect on the relative growth rate of A. microphylla and A. mexicana . The relative growth rates of the remaining Azolla species were also unaffected by ammonium sulphate, but were significantly lower with urea than with no nitrogen treatment.

Summary Algal growth medium (Chu-10) and saline magnesium chloride solution (100 mM NaCl + 2 mM MgCl 2 · 6 H 2 O) conferred total stability to the virus N-1 infecting the blue-green alga Nostoc muscorum , whereas inactivation in distilled water, saline solution (10 to 100 mM) and magnesium chloride solution (2 and 100 mM) was observed. The loss of biological activity of the virus in absence of the suitable salts was irreversible and the decline of virus titre in the incomplete diluent could be checked by supplementing the deleted salts at any stage of inactivation. Monovalent cations (100 mM) conferred stability to the virus in the order: Na + > K + alongwith 2 mM MgCl 2 · 6 H 2 O. The divalent cations (2 mM) were also ranked according to their stabilizing effectivity to the virus particles alongwith 100 mM NaCl in the decreasing order: Mg 2 + > Ca 2 + > Zn 2 + > Co 2 + > Ba 2 + > Mn 2 + > Sr 2 + .

Summary The chlorate and L-methionine DL-Sulfoximine resistant mutants were isolated in rice field cyanobacterium Aulosira spec. after N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. MSX-resistant mutant was partially blocked in the glutamine synthetase (GS) and exhibited 44.1 % GS transferase activity compared to the parent grown on N2. Unlike its parent, the mutant showed nitrogenase activity of 2.19 nmol/µ g chlorophyll a/h when grown in ammonia. The mutant resistant to both chlorate and JISX (ClrR MSXR) was defective in both nitrate reductase and GS. It possessed only 39.4 % GS transferase activity in NZ grown culture and 6.2 % of nitrate reductase activity in nitrate grown culture as compared to the parent. Unlike its parent this mutant exhibited nitrogenase activity of 2.22 and 4.34 nmol/µg chl - a/h when grown in nitrate and ammonia respectively. The maximum of the GS transferase and nitrogenase activities were observed on N2 grown cultures of parent, MSXR and ClrR MSXR mutants whereas minimum level of GS transferase was noticed in glutamine grown culture.

An exact theory of spectral response of thin-film epitaxial solar cells is developed, and a new expression for the effective back surface recombination velocity is derived. On the basis of this theory, the spectral response as a function of relevant cell parameters, such as dopings, diffusion lengths, and thicknesses of the substrate and epitaxial layer regions and the dead layer, is calculated. It was found that two effects mainly control the spectral response of epitaxial solar cells: (i) the doping ratio of substrate to epitaxial layer and (ii) the dead layer thickness. The former markedly influences the long wavelength region spectral response, while the latter has a profound effect on the short wavelength response. The theory also predicts a significant contribution from the substrate to the quantum efficiency. >

The magnetic susceptibility of II–VI compounds is correlated with certain physical paitameters, such as atomic numbers, band-gap energy, refractive index and lattice parameter. A plausible explanation is given to some of these correlations in the light of recent theories.