Thermoregulation (homeothermy) in animals involves a complex mechanism involving thermal receptors throughout the body and integration in the hypothalamus that controls shivering and non-shivering thermogenesis. The flowers of some ancient families of seed plants show a similar degree of physiological thermoregulation, but by a different mechanism. Here, we show that respiratory control in home...

Stability results are proved for traveling waves in a class of reaction-diffusion systems that arise in chemical reaction models. The class includes systems in which there is no diffusion in some equations. A weight function that decays exponentially at one end is required to stabilize the essential spectrum. Perturbations of the wave in H1 or BUC that are small in both the weighted norm and th...

Recent theoretical studies have suggested that the parent diazeniumdiolate ion, H2N-N(O)═NO(-) ("diazeniumdiolated ammonia"), might be stable enough to be isolated and that it could potentially serve as a uniquely advantageous prodrug form of bioactive nitroxyl (HNO). Here, we report on an attempt to isolate its O(2)-benzylated derivative by aminolysis of the C═N bond in PhC(NH2)═N-N(O)═NOBn. T...

The interactions of a-chymotrypsinogen A with urea, methyl-, N,N'-dimethyl-, ethyl-, N,N'-diethyl-, and propylurea were studied by means of calorimetry and circular dichroism. It has been found that the enthalpies of interaction of the alkylureas, with the exception of methylurea, with a-chymotrypsinogen A are distinctly from those of urea. Thus the transfer of the protein from water to aqueous...

Nuclear reactions proceed differently in stellar plasmas than in the laboratory due to the thermal effects in the plasma. On one hand, a target nucleus is bombarded by projectiles distributed in energy with a distribution defined by the plasma temperature. The mostly relevant energies are low by nuclear physics standards and thus require an improved description of low-energy properties, such as...

The potential energy along a reaction coordinate can be calculated in terms of the reaction energy, the force constants and the equilibrium bond lengths of the reactive bonds, the bond order at the transition state and, for very exothermic or endothermic reactions, the so called "configuration entropy". Such potential energy curves allows one to assess the importance of quantum mechanical tunne...

The reactions of CO(2) on the Al(100)(+) cluster have been investigated as a function of cluster temperature (300-1100 K) and relative kinetic energy (0.2-10 eV). Two main products are observed at low cluster temperature: Al(100)O(+) (which is believed to result from a stripping reaction) and Al(100)CO(2)(+) from complex formation. As the cluster temperature is raised, both products dissociate ...

The objective of this work is to make use of methodologies and tools from nonlinear Lyapunov theory in the design of bounded control laws for the temperature stabilisation of Continuous Stirred Tank Reactors CSTRs with exothermic or endothermic reactions Simple output feed back control laws i e control laws that feed back only the available mea surements are designed It is shown that these cont...

Some cyclic molecules have been proposed as liquid-organic hydrogen carriers (LOHC) due to their ability undergo dehydrogenation reversibly, with ones containing nitrogen in the ring showing special stability. Here, we examined one of these, 1,2,3,4-tetrahydroquinoline (THQ), for use an endothermic fuel thermal protection hypersonic aircraft engines. The conversion and heats reaction were measu...

On heating pure, fully saturated 2,3-diacyl-DL-phosphatidyl-ethanolamines and 2,3-diacylphosphatidyl-cholines (lecithins) in water to the transition temperature at which large endothermic heat changes occur, they are observed, by light microscopy, to form myelin figures. This result is discussed in terms of the large difference in the transition temperature for "melting" of the hydrocarbon chai...