Genetic variation for high temperature tolerance exists in wheat cultivars. Identifying key metabolic steps in this regard will help in improving grain yield. Effect of high temperature on activities of sucrose metabolizing enzymes and aminotransferases in relation to transformation of free sugars to starch and protein in developing grains of four wheat cultivars PBW 343, PBW 550, C 306, C 273 was studied by raising the crop under normal (October) and late planting (December) conditions. Significant reduction in chlorophyll content and increase in membrane injury index and lipid peroxidation were observed in all the cultivars. C 306 and C 273 showed higher membrane stability over PBW 343, PBW 550. High temperature accentuated sucrolytic enzymes and aminotransferases while activities of sucrose synthase/phosphate synthase got repressed. Higher build up of sugars and starch in PBW 343, PBW 550 cvs over C 306, C 273 resulted in higher yield in the former but their lower membrane integrity under heat stress leads to yield reductions. Disruption of starch biosynthesis resulted in their favoured utilization in nitrogen metabolism leading to higher amino acid and protein accumulation. Results indicated that sustainability for yield enhancement under stress could be possible by cross-breeding high yielding cvs PBW with increased membrane stability C ones for increasing thermotolerance. Grain filling processes in terms of sugars/starch were strongly correlated to sucrose synthase/phosphate synthase activities while protein to aminotransferases.
Information about patterns, mechanisms, and kinetic parameters of high-temperature decomposition of EM (that includes all explosives, pyrotechnic compositions, gun powders, and modern solid, liquid, and hybrid rocket propellants) is of large
Portland cement paste is a complex material that might contain some minor hydration products and calcium carbonate (CaCO 3 ). These minor phases can effect the total mass loss of cement paste at hightemperature. Therefore
Authors:Michael L. Hobbs, James T. Nakos, and Patrick D. Brady
hightemperatures include measuring thermal conductivity and specific heat during decomposition. Difficulties arise when the endothermic and/or exothermic reaction enthalpies confound the thermophysical property measurement. Significant volume changes
A research program has been in progress to obtain reliable thermodynamic data on various binary and ternary alkali metal compounds
in the temperature range of 300 to 1500 K. To date, heat capacity measurements have been made on cesium and rubidium chromates,
dichromates, zirconates, molybdates, dimolybdates, and halides in the temperature range of 300 to 800K. In addition, measurements
are planned or are currently in progress on cesium and rubidium chalcogenides, aluminates, uranates, silicates, and several
other lithium, sodium, and potassium compounds. The status of the research program is discussed.
Authors:Alexandra Ioana Bucur, Raul Bucur, Titus Vlase, and Nicolae Doca
weighing of the sample and (b) room temperature XRD (after cooling) [ 2 ], the high-temperature X-ray diffraction (HTXRD) presents the advantage of in situ analysis of the sample, at the desired temperature, eliminating errors that may appear due to factors
Authors:Saet Byul Kim, Mi Ran Lee, Eun Duck Park, Sang Min Lee, HyoKyu Lee, Ki Hyun Park, and Myung-June Park
catalyst but in hightemperature water (HTW), suggesting that side reactions are decreased at low temperature. Akiya and Savage [ 12 ] reported that HTW can be substituted for acid catalysts due to its high tendency for ionization; both temperature and