Approximation for the enhancement factor applicable to reversible reactions of finite rate in chemically loaded solutions.

A new explicit relation is proposed for the prediction of the enhancement factor for reversible reactions of finite rate in chemically loaded solutions which also allows for unequal diffusivities. The relation for the enhancement factor is not based on an approximation of the absorption process, but is derived from a similarity which can be observed between the results of the approximation for an irreversible (1,1) order reaction given by, for example, DeCoursey (surface renewal model), and the exact numerical results. The present relation combines the solution of DeCoursey (1974 Chem. Engng Sci. 29, 1867¿1872) for irreversible finite rate reactions, and the solution of Secor and Beutler (film model, 1967 A.I.Ch.E. J. 13, 365¿373) for instantaneous reversible reactions. The diffusivity ratios in the solution of Secor and Beutler (1967) were replaced by the roots of these ratios in order to adapt the enhancement factors to the penetration theory. In general, this adaptation of the solution of Secor and Beutler gave reasonably good results, however, for some situations with unequal diffusivities deviations up to 20% were found. The results of the present approximation were for various reactions compared to the numerical enhancement factors obtained for the model based on the Higbie penetration theory. Generally, the agreement was reasonably good. Only 26 of 2187 preselected simulations (1.18%) had a deviation which was larger than 20%, while the average deviation of all simulations was 3.3%. The deviations increased for solutions with a substantial chemical loading in combination with unequal diffusivities of the components. For reactions with a kinetic order unequal to unity, the Ha number had to be multiplied by a factor, ¿¿, so that Ea = ¿¿H aA in the regime 2 < HaA Ea,¿. This factor agreed well with the factor given by Hikita and Asai (1964, Int. Chem. Engng 4, 332¿340) in their dimensionless numbe

Effect of Silver Ions on Ethylene Metabolism of Mustard Grown Under Irrigated and Non- irrigated Conditions

A field experiment was conducted during the winter season of 2004-2005 at the Experimental farm of Aligarh Muslim University, Aligarh, India on mustard (Brassica juncea L. Czen and Coss, cultivar Alankar) under irrigated and non -irrigated  conditions to evaluate the application of 0  and 200 µl/L  ethrel (E200) or 1 mM silver thiosulphate (S) at flowering stage along with a basal  uniform application of 80 kg N ha-1 on leaf area, plant dry mass, net photosynthetic rate and seed yield. Silver thoisulphate, which inhibits the physiological action of ethylene was used in the experiment with ethrel. Ethrel is a source of ethylene and its effects are manifested through physiological action of ethylene. Ethrel 200 µl/L (E200) treatment enhanced leaf area, net photosynthetic rate, plant dry mass and seed yield by 10.6, 9.1, 7.7 and 11.6% over S treatment. So silver thiosulphate (S) reduces the physiological action of ethrel (source of ethylene) in this study. This clearly indicates that silver ions used in this experiment in the form of silver thiosulphate inhibits the action of ethylene metabolism in mustard

Biopesticides: Ecofriendly and biorational alternatives to vegetable production and environmental sustainability

Insect pests, nematodes and plant diseases of vegetables are generally controlled by frequent applications of chemical pesticides with an objective to increase crop productivity and obtain greater profit in conventional farming. With consumers' awareness and perception, vegetables without residue of chemicals are being preferred in local and export markets. For this purpose, plant-derived crude products or formulated pesticides can be eco-friendly, effective and economical for an average producer. Several pressures have accelerated the search for more environmentally and toxicologically safe and more selective and efficacious pesticides. Biopesticides, including microbial pesticides, entomopathogenic nematodes, baculoviruses, plant derived pesticides, and insect pheromones are receiving increased exposure in scientific annals as alternatives to chemical pesticides and also as key components of integrated pest management (IPM) systems. The reality, however, is that biopesticides currently represent only a small fraction (1.3%) of the world pesticide market. However, the growth rate for biopesticides over the next 10 years has been forecast at 10–l5% per annum in contrast to 2% for chemical pesticides. It is imperative to make aware the farming community regarding the use of biopesticides to reduce the environmental pollution

Effect of ethrel and nitrogen on nitrate reductase activity, photosynthesis, biomass and yield of mustard (Brassica juncea L. Czern and Coss)

      The plants of mustard (Brassica juncea L. Czern and Coss; cultivar Alankar) were treated with 200 µL/L ethrel (2-chloro ethyl phosphonic acid) at flowering stage (60 d after sowing) along with basal application of nitrogen 40, 60, and 80 kg N ha-1. Effect of ethrel and nitrogen on leaf area index (LAI), net photosynthetic rate (PN), nitrate reductase (NR) activity and plant dry mass were recorded at 80 and 100 d after sowing. At harvest pods plant-1, 1000 seed mass and seed yield were recorded. Ethrel 200 µL/L x 80 kg N ha-1 treatment enhanced all the characteristics studied during the experiment

Assessment of marker-trait associations for drought and heat tolerance in bread wheat

Abiotic stresses are major constraints to wheat productivity in many parts of the world. Tolerance to abiotic stresses can be achieved indirectly by selection for morpho-physiological traits. Physiological trait based breeding has been associated with improved performance under stress; and hence can combat and adapt wheat to drought and heat stress. Therefore, in the present study, phenotyping was carried out for agro-physiological traits in 52 diverse wheat germplasm lines under timely sown, rainfed and late sown environments for two years. Mean yield of the genotypes over the six environments were positively correlated with NDVI, days to maturity and negatively correlated with canopy temperature. The phenotypic data validated marker-trait associations of a number of meta-QTLs identified earlier for different physiological and agronomic traits. Six and seven meta-QTL genomic regions were found to be consistent in their expression for two years under rainfed/restricted irrigation and late sown environments, respectively. Expression analysis of the underlying candidate gene AK248593.1 in meta-QTL26 region revealed two folds higher expression in the NILs carrying the co-localized SSR markers. The linked markers of the thirteen meta-QTL regions associated with different traits can be used for effective transfer of the QTLs through marker assisted selection in wheat breeding programmes

Plasma Turbulence in the Local Bubble

Turbulence in the Local Bubble could play an important role in the thermodynamics of the gas that is there. The best astronomical technique for measuring turbulence in astrophysical plasmas is radio scintillation. Measurements of the level of scattering to the nearby pulsar B0950+08 by Philips and Clegg in 1992 showed a markedly lower value for the line-of-sight averaged turbulent intensity parameter $$than is observed for other pulsars, consistent with radio wave propagation through a highly rarefied plasma. In this paper, we discuss the observational progress that has been made since that time. At present, there are four pulsars (B0950+08, B1133+16, J0437-4715, and B0809+74) whose lines of sight seem to lie mainly within the local bubble. The mean densities and line of sight components of the interstellar magnetic field along these lines of sight are smaller than nominal values for pulsars, but not by as much expected. Three of the four pulsars also have measurements of interstellar scintillation. The value of the parameter$$ is smaller than normal for two of them, but is completely nominal for the third. This inconclusive status of affairs could be improved by measurements and analysis of ``arcs'' in ``secondary spectra'' of pulsars.Comment: Submitted to Space Science Reviews as contribution to Proceedings of ISSI (International Space Science Institute) workshop "From the Heliosphere to the Local Bubble". Refereed version accepted for publicatio

Radio precursors to neutron star binary mergings

We discuss a possible generation of radio bursts preceding final stages of binary neutron star mergings which can be accompanied by short gamma-ray bursts. Detection of such bursts appear to be advantageous in the low-frequency radio band due to a time delay of ten to several hundred seconds required for radio signal to propagate in the ionized intergalactic medium. This delay makes it possible to use short gamma-ray burst alerts to promptly monitor specific regions on the sky by low-frequency radio facilities, especially by LOFAR. To estimate the strength of the radio signal, we assume a power-law dependence of the radio luminosity on the total energy release in a magnetically dominated outflow, as found in millisecond pulsars. Based on the planned LOFAR sensitivity at 120 MHz, we estimate that the LOFAR detection rate of such radio transients could be about several events per month from redshifts up to $z\sim1.3$ in the most optimistic scenario. The LOFAR ability to detect such events would crucially depend on exact efficiency of low-frequency radio emission mechanism.Comment: 6 pages, 2 figures, Accepted for publication in Astrophysics & Space Science. Largely extended version of ArXiv:0912.521

Triaxial projected shell model study of chiral rotation in odd-odd nuclei

Chiral rotation observed in $^{128}$Cs is studied using the newly developed microscopic triaxial projected shell model (TPSM) approach. The observed energy levels and the electromagnetic transition probabilities of the nearly degenerate chiral dipole bands in this isotope are well reproduced by the present model. This demonstrates the broad applicability of the TPSM approach, based on a schematic interaction and angular-momentum projection technique, to explain a variety of low- and high-spin phenomena in triaxial rotating nuclei.Comment: 14 pages, 4 figures, 1 Tabl

Multi-quasiparticle gamma-band structure in neutron-deficient Ce and Nd isotopes

The newly developed multi-quasiparticle triaxial projected shell-model approach is employed to study the high-spin band structures in neutron-deficient even-even Ce- and Nd-isotopes. It is observed that gamma-bands are built on each intrinsic configuration of the triaxial mean-field deformation. Due to the fact that a triaxial configuration is a superposition of several K-states, the projection from these states results in several low-lying bands originating from the same intrinsic configuration. This generalizes the well-known concept of the surface gamma-oscillation in deformed nuclei based on the ground-state to gamma-bands built on multi-quasiparticle configurations. This new feature provides an alternative explanation on the observation of two I=10 aligning states in 134Ce and both exhibiting a neutron character.Comment: 15 pages, 9 figures, accepted by Nucl. Phys.