Protein Condensation Gunton, James D.; Shiryayev, Andrey; Pagan, Daniel L.
09/2007
eBook
The quest to understand the condensation of proteins from solutions is a rapidly evolving field. The purpose of this book is to bring to an interdisciplinary audience the state-of-the-art in current ...research. The first part of the book deals with issues related to the production of high quality protein crystals from solution. Since protein function is determined by structure, high quality protein crystals must be grown in order to determine their structure by X-ray crystallography. The book also discusses diseases that occur due to undesired protein condensation, an increasingly important subject. Examples include sickle cell anemia, cataracts and Alzheimer's disease. Current experimental and theoretical work on these diseases is discussed, which seeks understanding at a fundamental, molecular level, to prevent the undesired condensation from occurring. The book, containing color plate sections, is suitable for graduate students and academic researchers in physics, chemistry, structural biology, protein crystallography and medicine.
The glass transition temperature (Tg) in water is still uncertain, with conflicting values reported in the literature. As with other hyperquenched glasses, water exhibits a large relaxation exotherm ...on reheating at the normal rate of 10 kelvin (K) per minute. This release of heat indicates the transformation of a high enthalpy state to a lower one found in slow-cooled glasses. When the exotherm temperature is scaled by Tg, the good glass-formers show a common pattern. However, for hyperquenched water, when this analysis is performed using the commonly accepted$T_g = 136\>K$, its behavior appears completely different, but this should not be the case because enthalpy relaxation is fundamental to the calorimetric glass transition. With Tg= 165 ± 5 K, normal behavior is restored in comparison with other hyperquenched glasses and with the binary solution behavior of network-former systems (H2O, ZnCl2, or BeF2plus a second component). This revised value has relevance to the understanding of water-biomolecule interactions.
This is a graduate textbook describing atomic-level kinetics (mechanisms and rates) of thermal energy storage; transport (conduction, convection, and radiation); and transformation (various energy ...conversions) by principal energy carriers. These carriers are: phonon (lattice vibration wave also treated as quasi-particle), electron (as classical or quantum entity), fluid particle (classical particle with quantum features), and photon (classical electromagnetic wave also as quasi-particle). The approach combines the fundamentals of the following fields: molecular orbitals-potentials, statistical thermodynamics, computational molecular dynamics, quantum energy states, transport theories, solid-state and fluid-state physics, and quantum optics. These are rationally connected to atomic-level heat transfer and thermal energy conversion. This textbook presents a unified theory, over fine-structure/molecular-dynamics/Boltzmann/macroscopic length and time scales, of heat transfer kinetics in terms of transition rates and relaxation times, and modern applications, including nano- and microscale size effects. Numerous examples, illustrations, and homework problems with answers enhance learning.
In the present study, the effect of S and Se substitution on structural, electrical and optical properties of AgGa(Se2-xSx) thin films has been investigated.
AgGa(Se0.5S0.5 )2 thin films were ...prepared by using the thermal evaporation method. X-ray diffraction (XRD) analysis has revealed that the transformation from amorphous to polycrystalline structure took place at about 450 oC. The detailed information about the stoichometry and the segregation mechanisms of the constituent elements in the structure has been obtained by performing both energy dispersive X-ray analysis (EDXA) and X-ray photoelectron spectroscopy (XPS) measurements.
AgGaSe2 thin films were deposited by using both electron-beam (e-beam) and sputtering techniques. In e-beam evaporated thin films, the effect of annealing on the structural and morphological properties of the deposited films has been studied by means of XRD, XPS, scanning electron microscopy (SEM) and EDXA measurements. Structural analysis has shown that samples annealed between 300 and 600 oC were in polycrystalline structure with co-existance of Ag, Ga2Se3, GaSe, and AgGaSe2. The variation of surface morphology, chemical composition and bonding nature of constituent elements on post-annealing has been determined by EDXA and XPS analyses.
AgGaSe2 thin films were also prepared by using sputtering technique. XRD measurements have shown that the mono-phase AgGaSe2 structure is formed at annealing temperature of 600 oC. The crystal-field and spin-orbit splitting levels were resolved. These levels around 2.03 and 2.30 eV were also detected from the photospectral response measurements.
Thin films of Ag-Ga-S (AGS) compound were prepared by using AgGaS2 single crystalline powder and deposition of the excess silver (Ag) intralayer with double source thermal evaporation method. As a consequence of systematic optimization of thickness of Ag layer, Ag(Ga,S) with the stoichiometry of AgGa5S8 and AgGaS2 were obtained and systematic study to obtain structural, electrical and optical properties was carried out.
This is a graduate textbook describing atomic-level kinetics (mechanisms and rates) of thermal energy storage; transport (conduction, convection, and radiation); and transformation (various energy ...conversions) by principal energy carriers. These carriers are: phonon (lattice vibration wave also treated as quasi-particle), electron (as classical or quantum entity), fluid particle (classical particle with quantum features), and photon (classical electromagnetic wave also as quasi-particle). The approach combines the fundamentals of the following fields: molecular orbitals-potentials, statistical thermodynamics, computational molecular dynamics, quantum energy states, transport theories, solid-state and fluid-state physics, and quantum optics. These are rationally connected to atomic-level heat transfer and thermal energy conversion. This textbook presents a unified theory, over fine-structure/molecular-dynamics/Boltzmann/macroscopic length and time scales, of heat transfer kinetics in terms of transition rates and relaxation times, and modern applications, including nano- and microscale size effects. Numerous examples, illustrations, and homework problems with answers enhance learning.
