Heat stress tolerance in peas (Pisum sativum L.): Current status and way forward

In the era of climate change, the overall productivity of pea (Pisum sativum L.) is being threatened by several abiotic stresses including heat stress (HS). HS causes severe yield losses by adversely affecting several traits in peas. A reduction in pod yield has been reported from 11.1% to 17.5% when mean daily temperature increase from 1.4 to 2.2°C. High-temperature stress (30.5-33°C) especially during reproductive phase is known to drastically reduce both seed yield and germination. HS during germination and early vegetative stage resulted in poor emergence and stunted plant growth along with detrimental effects on physiological functions of the pea plant. To combat HS and continue its life cycle, plants use various defense strategies including heat escape, avoidance or tolerance mechanisms. Ironically, the threshold temperatures for pea plant and its responses are inconsistent and not yet clearly identified. Trait discovery through traditional breeding such as semi leaflessness (afila), upright growing habit, lodging tolerance, lower canopy temperature and small seeded nature has highlighted their utility for greater adaptation under HS in pea. Screening of crop gene pool and landraces for HS tolerance in a targeted environment is a simple approach to identify HS tolerant genotypes. Thus, precise phenotyping using modern phenomics tools could lead to increased breeding efficiency. The NGS (next generation sequencing) data can be associated to find the candidate genes responsible for the HS tolerance in pea. In addition, genomic selection, genome wide association studies (GWAS) and marker assisted selection (MAS) can be used for the development of HS tolerant pea genotypes. Additionally, development of transgenics could be an alternative strategy for the development of HS tolerant pea genotypes. This review comprehensively covers the various aspects of HS tolerance mechanisms in the pea plant, screening protocols, omic advances, and future challenges for the development of HS tolerant genotypes

Loss of prestress due to time-dependent deformations of concrete and steel

Bibliography: p. 241-243

Observation of grey cesium tin bromide with unusual phase transition

A new grey colour polymorph of CsSnBr3 with non-cubic phase at 295(±1) K is observed. Contrary to black and yellow polymorphs, it seems that not only the β-α transition at 292 K shifted to 304 K but also the new β3-phase with second-order phase transition (β2-β3) can be seen in this new grey polymorph. The structural refinement shows the monoclinic $\text {C}_{2h}^{5} \text {-} P2_{1}/c$ phase with holohedry for β3-CsSnBr3 against the group-subgroup theory. However, the parameters $c/a\,{\sim}\,1.492$ and $b/c\,{\sim}\,1.004$ are suggesting pseudo-tetragonality for β3-CsSnBr3

Performance Analysis of Single Glazed Solar PVT Air Collector in the Climatic Condition of NE India

With the rapid depletion of fossils fuels, opportunities for renewable energy including solar energy are endless. The efficiency of photovoltaic cells to convert the solar energy into electricity drops with the rise in temperature due to increased resistance. Thus, improving the efficiency by lowering the thermal resistance and allowing the cooling fluid (air/water) to flow through photovoltaic thermal (PVT) system is an attractive option. Climate condition based performance of any PVT system varies location wise, and cannot be generalized. Silchar is a city located in Himalayan region has tropical climatic conditions and most of its decentralized villages are out of grid connectivity. Unlike other metro cities of India, PVT will play a critical role for the development of theses villages. Keeping this in mind an attempt is made in the present study to perform an analysis of single glazed solar PVT air collector on the basis of energy and exergy for the climatic conditions of Silchar, India. An analytical model is developed to evaluate the hourly variation of PV cell temperature, cell efficiency, useful thermal heat gain, useful electrical heat gain, energy efficiency and exergy efficiency PVT system. Results depict that efficiency of PV cell decreases with the increase in temperature, and a maximum efficiency of 14.6% for the PV module is found. Out of total useful heat output, the thermal heat output contributes 60.7% while the rest is electrical heat output. Further, magnitude of the heat output is found to increase with the solar radiation and the maximum observed solar ray at around 12:30 h. Trend of both energy and exergy efficiency is similar except the magnitude. Maximum efficiency observed to be 83% and 16.5% for energy and exergy, respectively

Sm/Ti co-substituted bismuth ferrite multiferroics: reciprocity between tetragonality and piezoelectricity

BiFeO3 (BFO) systems co-modified with Ti, Sm and Sm-Ti have been investigated for piezoelectricity together with dielectric and multiferroic properties. Structural studies revealed the coexistence of orthorhombic and rhombohedral (R3c) phases for x > 0.12. Impurity phases were shown to have hardly any effect on the remanent magnetization, which rather depends on the Fe-O-Fe bond angle. The dielectric loss was reduced considerably by substitution. A correlation between the piezoelectric coefficient and tetragonality was observed in these samples. BFO co-substituted with Sm-Ti exhibited a high piezoelectric coefficient with better ferroic properties, which revealed a unique combination of green piezoelectricity and multiferroicity