Circular Dichroism Measurements on C-Terminal Fragment of Heat Shock Protein from Rat

The secondary structure of the C-terminal fragment (10 kDa) of rat hsc70 (a. a. #546–646) was analyzed according to circular dichroism spectra. In the pH range 5–9 and at concentrations of Na+ up to 0.18 M, the protein is estimated to contain 32-34% a helix, 18–16% of β sheet, approximately 25% for both turns and disordered structures. This protein is most stable at pH between 6 and 7 in solution with 0.055 M Na⁺ concentration. However, all T_m are relatively large (57–73 °C) and alterations from one condition to another are small. Thus, the C-fragment (10 kDa) of hsc70 is a stably folded protein under physiological conditions.     

Photochemical Activities of N‐Nitroso Carboxamides and Sulfoximides and Their Application to DNA Cleavage

N‐Nitroso compounds containing benzene, fluorene or fluorenone rings were synthesized. Photolysis of these compounds with 312‐nm UV light provided the NO ^. species, the presence of which was corroborated by use of an EPR method and of 2‐phenyl‐4,4,5,5‐tetramethylimidazolin‐1‐oxyl 3‐oxide (PTIO) as a trapping agent. During irradiation of N‐methyl‐N‐nitroso‐9‐fluorenone carboxamide ( 14 c ) in the absence of PTIO, it underwent decomposition followed by recombination to give the heterocyclic nitric oxide radical 15 . Incorporation of intercalating moieties endowed the N‐nitroso compounds with DNA‐cleaving ability through single‐strand scission upon UV irradiation in a phosphate buffer (pH 5.0–8.0) under aerobic conditions.     

Electronic structure of semiconducting crystals under high stress

We present a calculation of the band structure of semiconducting crystals under arbitrarily high stress, in which all input parameters are determined from the properties of the unstressed crystal alone. The method is applied to obtain the band structure of Ge and Si at high stress, and the strain dependence of the energies and matrix elements of a number of critical-point transitions are presented.     

Tidal Effects on Groundwater Motions

Assuming a sharp interface between freshwater and seawater within a coastal aquifer, a theory is developed to account for the piezometric head movement of steady and unsteady components in terms of large- and small-time scales. Tidal fluctuations are simulated by a series of decomposed simple harmonic motions in time. Groundwater fluctuation induced by tidal motion is perturbed to the groundwater head of large-time scale. Ghyben–Herzberg formulation is applied for solutions of large-time scale and a unified formulation for various flows of small-time scale is derived (Strack, 1989). Approximate analytical solutions for amplitudes and phase lags of tidal groundwater motions and the freshwater–seawater interface for a coastal aquifer in a circular island are obtained. The induced fluctuation amplitude generally decays in distance with a parameter consisting of hydraulic conductivity, storage coefficient, thickness of aquifer and tidal period. The present approach can be applied to confined and unconfined aquifers, with only freshwater flows or interfacial flows. The theory is verified with some experimental results (Parlange, et al., 1984; Nielson, 1990). It can also used to determine physical parameters of an aquifer by monitoring the groundwater fluctuations due to tidal motions (Carr and van der Kamp, 1969).     

Generation of stable solitary waves by a piston-type wave maker

The focus of present study is on how to generate solitary waves as pure as possible by using a piston type wave maker. A meshless numerical model, which can simulate the trajectories of fluid particles in a wave motion exerted by the wave paddle, is established for the purpose of present study. The present numerical model is verified by the comparison with experimental data before it is employed to the focused problem. Various wave paddle motions are considered. The results show that solitary waves generated by applying Fenton’s solitary solution to the paddle motion proposed by Goring are purer than those generated by other paddle motions.     

Effects of solid and slotted baffles on the convection characteristics of backward-facing step flow in a channel

This study investigates the enhancement of the laminar forced convection characteristics of backward-facing step flow in a two-dimensional channel through the installation of solid and slotted baffles onto the channel wall. The effects of the height of baffle H _b, inclination of baffle installation ϕ_b, height of slot in baffle H _t, inclination of slot in baffle ϕ_t, and distance between the backward-facing step and baffle D on the flow structure, temperature distribution and Nusselt number variation for the system at various Re are numerically explored. Results show that a slotted baffle can enhance the average Nusselt number for the heating section of channel plate by the maximum 190% when Pr=0.7, H _s=0.5, L=5, H _b ≤ 0.3, W _b ≤ 0.2, 0.1 ≤ D ≤ 0.5, 0° ≤ ϕ_b ≤ 45°, H _t ≤ 0.1, 0° ≤ ϕ_t ≤ 45° and 50 ≤ Re ≤ 400. As for the solid baffle, the enhancement may be up by 230%. The solid baffle might cause the re-separation of main stream, and consequently result in poor local heat transfer coefficient in the end region of heating section. This disadvantage can be obviously improved as the baffle is slotted. Besides the penalty of increase in pressure drop due to the baffle installation is much higher for the situation with solid baffle.     

Combined heat and mass transfer in laminar gas stream flowing over an evaporating liquid film

A numerical analysis was carried out to study the detailed heat and mass transfer characteristics in laminar gas stream flowing over a falling liquid water film by solving the respective governing equations for the liquid film and gas stream together. It was observed that the cooling of the liquid film is mainly caused by the latent heat transfer connected with the vaporization of the liquid film. Significant liquid cooling results for the system with a high inlet liquid temperature, high gas stream velocity or a low liquid flowrate. Additionally, the predicted Nusselt and Sherwood numbers were correlated.