Radiochemical analysis of rubble and trees collected from Fukushima Daiichi Nuclear Power Station

To characterize the rubble and trees contaminated by radionuclides released by the recent accident at the Fukushima Daiichi Nuclear Power Station, the radiochemical analysis protocols were modified using those developed by the Japan Atomic Energy Agency for the waste generated by research, industrial, and medical facilities. The radioactivity concentrations of gamma-ray-emitting nuclides ⁶⁰Co, ⁹⁴Nb, ¹⁵²Eu, and ¹⁵⁴Eu, and beta-particle-emitting nuclides ¹⁴C, ¹²⁹I, ³⁶Cl, ⁷⁹Se, and ⁹⁹Tc were successfully applied by the modified analytical method. In contrast, the radioactivity concentrations of ³H, ⁹⁰Sr, ¹³⁷Cs, and alpha-particle-emitting nuclides were applied by the conventional method. Unfortunately, ³⁶Cl, ⁹⁴Nb, ¹²⁹I, ¹⁵²Eu, ¹⁵⁴Eu, and alpha-particle-emitting nuclides were below the detection limit of the conventional method. The measured radioactivity concentrations, except for that of ³H, were not uniform in the area but depended on the reactor unit. Although the radioactivity concentrations were varied widely, this analysis successfully clarified the characteristics of the radioactivity concentrations of the rubble and trees.     

Determination of various constituent elements of polyethylene terephthalate bottles used for beverages in Japan

Polyethylene terephthalate (PET) bottles are some of the most commonly used containers for beverages. During the manufacturing process of PET resin in Japan, metallic catalysts such as Sb and Ge are widely used, with other metals or metallic compounds also being employed to improve the quality of PET bottles. However, few reports into the contents of such elements exist. Thus, we herein report the concentrations of 34 elements (ie, Li, B, Na, Mg, Al, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Zr, Mo, Ag, Cd, Sn, Sb, Cs, Ba, W, Pb, and U) in 16 samples of unused virgin PET bottles for beverages. The measurement was performed by inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS), and these bottles were found to contain five main elements (ie, <0.5- to 50-mg/kg Ge, <1- to 26-mg/kg Ti, <0.1- to 279-mg/kg Sb, <10- to 48-mg/kg P, and <0.5- to 53-mg/kg Co) that were used as polymerisation catalysts, stabilisers, oxidation catalysts, and bluing agents. Furthermore, when these residual element concentrations in 21 commercial mineral-water PET bottles were determined, there was no significant difference from unused bottles.     

Natural convection and radiation heat transfer in a vertical porous layer with a hexagonal honeycomb core (Part 1: numerical analysis)

Combined heat transfer characteristics were obtained numerically for three-dimensional natural convection and thermal radiation in a long and wide vertical porous layer with a hexagonal honeycomb core. We assumed that the porous layer was both homogeneous and isotropic. The pure Darcy law for fluid flow and Rosseland's approximation for radiation were used. The numerical methodology was based on an algebraic coordinate transformation technique and the transformed governing equations were solved using the SIMPLE algorithm. The effect of radiation on the heat transfer characteristics was investigated over a wide range of radiation numbers and temperature ratios for two Darcy-Rayleigh number values (Ra^* = 100 and 1000) and for a fixed aspect ratio of H/L = 1. The results are presented in the form of combined radiation and convection heat transfer coefficients and are compared with the corresponding values for pure natural convection. © 1999 Scripta Technica, Heat Trans Asian Res, 28(4): 278–294, 1999     

Identification of enzyme responsible for erythritol utilization and reaction product in yeast Lipomyces starkeyi

We have identified the enzyme responsible for erythritol utilization and its reaction product in the yeast Lipomyces starkeyi CBS 1807. The enzyme, a polyol dehydrogenase requiring NAD+ as a coenzyme, was induced by erythritol in this yeast. We confirmed that the enzyme product was L-erythrulose by MS, NMR, and polarimeter analyses, meaning that we clarified the first step of erythritol utilization in yeasts for the first time. In the case of the oxidative reaction, D-threitol, (2R,3R)-2,3-butanediol, and erythritol were much better substrates than 21 other polyols tested. These three substrates are tetroses and have an R configuration at C-3, and whose third carbon results in easiest oxidation in this enzyme. The research of the substrate specificity in the reductive reaction demonstrated that L-erythrulose and dihydroxyacetone were better substrates, that D-acetoin was inactive and L-erythrose (aldose) was slightly active.     

Heat transfer characteristics of gaseous slip flow in a micro-channel

Two-dimensional compressible momentum and energy equations with slip boundary conditions are solved to obtain the heat transfer characteristics of gaseous slip flow in a micro-channel with CWT (constant wall temperature) whose temperature is lower or higher than the inlet temperature (cooled case or heated case). The numerical methodology is based on the Arbitrary-Lagrangian-Eulerian (ALE) method. The stagnation temperature is fixed at 300 K and the computations were done for the wall temperature which ranges from 250 K to 350 K. The channel height ranges from 2 to 10 μm and the channel aspect ratio is 200. The stagnation pressure is chosen in such a way that the exit Mach number ranges from 0.1 to 0.7. The outlet pressure is fixed at atmospheric condition. The bulk temperature and the total temperature of the heated case are compared with those of the cooled case and also compared with temperatures of the incompressible flow in a conventional sized channel. Heat transfer characteristics of the gaseous flow are different from those of the liquid flow. And they are also different from each cooled and heated case. A correlation for the prediction of the heat transfer rate of the gaseous slip flow in a micro-channel is proposed.     

The desire to expel unselfish members from the group.

An initial study investigating tolerance of group members who abuse a public good surprisingly showed that unselfish members (those who gave much toward the provision of the good but then used little of the good) were also targets for expulsion from the group. Two follow-up studies replicated this and ruled out explanations grounded in the target being seen as confused or unpredictable. A fourth study suggested that the target is seen by some as establishing an undesirable behavior standard and by others as a rule breaker. Individuals who formed either perception expressed a desire for the unselfish person to be removed from the group. Implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some considerations on thermal boundary condition of slip flow

The slip effect of gaseous flow in a micro-scale channel is dominant when the characteristic length is less than about 10 μm under atmospheric conditions. The slip flow in a channel whose wall temperature is specified can be analyzed by solving the momentum and energy equations with taking into account the slip velocity and temperature jump. However, when there is slip, the shear work due to the slip at the wall should be included to calculate the heat flux from the wall. Unfortunately, the need of inclusion of the shear work in the heat balance equation has not been physically explained. In this paper, the physical reason of the inclusion of the shear work in the heat balance equation is physically explained from the point of view of both conservation law of energy and the kinetic theory of gases.