Densification of magnesia-based inert matrix fuels using asbestos waste-derived materials as a sintering additive

A new concept for densification of minor actinide-containing inert matrix fuels (IMFs) using asbestos waste-derived materials was proposed for the effective utilization of resources and health protection of the general public. In this concept, magnesium silicates, which are mainly generated by the decomposition of asbestos in low temperature heat-treatments, are used as a sintering additive to achieve high density magnesia (MgO) -based IMFs at relatively low sintering temperature. In the present study, preliminary fabrication tests of MgO-based IMFs with magnesium silicates were carried out using cerium oxide (CeO₂) as a representative of minor actinide oxides. The sintered densities of MgO-based IMFs increased with use of the additives. The sintering behavior of MgO-based IMFs with magnesium silicate additives was discussed from the viewpoints of the effects of magnesium silicates on the densification of the MgO and CeO₂.     

Sloshing suppression control of liquid transfer systems considering a 3-D transfer path

In plants in many industries, there exist a lot of transfer systems with vibration mechanisms. While transfer without residual vibration is usually demanded in these plants, this requirement necessitates large numbers of sensors and complicated models for control design. Therefore, This work presents a trajectory control design method to suppress residual vibration in transfer systems without the need to directly measure vibration. The proposed method consists of two parts. First, the frequency characteristics of the controller, comprised of control elements with simple structures such as a notch filter and a low-pass filter, are shaped as needed to suppress vibration. Next, various parameters of the control elements are determined by solving an optimization problem with penalty terms expressed by the constraints of both the time and frequency domains. The proposed method is applied to a liquid container transfer system, with special consideration given to the suppression of sloshing (liquid vibration) as well as to the maintenance of a high-speed transfer on the container's three-dimensional transfer path. The obtained controller demonstrates good performance for all demands. The effectiveness of the control design method is shown by experiments.     

Growth of Lactobacillus bulgaricus in milk. 2. Characteristics of purine nucleotides, pyrimidine nucleotides, and nucleic acid synthesis

Lactobacillus bulgaricus incorporated exogenous guanine only into guanine nucleotides and not into adenine nucleotides. Lactobacillus bulgaricus lacks the ability to interconvert adenine nucleotides and guanine nucleotides. Biosynthesis of pyrimidine nucleotides from orotic acid was depressed by addition of guanosine monophosphate or adenosine monophosphate. Some step in pyrimidine biosynthesis from orotic acid may be negatively regulated by the intracellular amount of purine nucleotides. Lactobacillus bulgaricus could not grow in milk from which orotate was removed. This indicates that the activity of de novo pyrimidine synthesis is very low in this organism. When the intracellular amount of purine or pyrimidine base was limited, ribonucleic acid synthesis was markedly depressed, resulting in cell elongation, whereas deoxyribonucleic acid synthesis was not so much affected.     

Varieties of antioxidant and antibacterial properties of Ecklonia stolonifera and Ecklonia kurome products harvested and processed in the Noto peninsula,Japan

Ecklonia stolonifera and Ecklonia kurome are traditional edible brown algae in the fisheries towns in Far East Asia. In the Noto Peninsula area, Ishikawa, Japan, both the Ecklonia are called ‘kajime’ and people believe that the algae improve the property of blood. To determine the varieties of antioxidant and antibacterial properties E. stolonifera and E. kurome products, assays for total phenolic content and antioxidant activities, including DPPH radical-scavenging activity, superoxide anion radical-generated by non-enzymatic system, ferrous-reducing power and WST-8, a tetrazolium salt, redox activity of four dried and two boiled E. stolonifera, and four dried and two raw E. kurome preparations were tested in this study. Furthermore, antibacterial activity of the products was tested. Though the total phenolic content, the antioxidant activity and the antibacterial activities of E. stolorifera and E. kurome products were high, these properties were varied by manufacturers or each product. Especially, two dried and two boiled products of E. stolonifera showed low activities. The results of this study indicate that the contents of functional compounds and their activities were affected or decreased greatly by the processing method.     

Frequent occurrence of hepatocytic apoptosis in acute rejection of the grafted rat liver

The present study was conducted to examine the histopathological changes of rat liver grafts in the early post-transplantation period. A total of 44 orthotopic liver transplantations were performed using cuff techniques without anastomosis of the hepatic artery. They were divided into four groups: (i) group 1 (syngeneic, Lewis-->Lewis; n = 10); (ii) group 2 (allogeneic, ACI-->Lewis; n = 20); (iii) group 3 (allogeneic with immunosuppression, ACI-->Lewis; n = 12); and (iv) long-surviving grafts (PVG-->Lewis; n = 2). The histological findings were classified into four categories: (i) mild dilatation of Disse's spaces due to ischemia; (ii) bile duct proliferation; (iii) acute rejection; and (iv) zonal necrosis. Bile duct proliferation occurred on day 6 in all three groups and in one of the two long-surviving grafts (120 days). Acute rejection occurred on day 3 and progressed in groups 2 and 3. Zonal necrosis developed in group 2 after day 6, while acute rejection subsided after day 4 in group 3 receiving 15-deoxyspergualin. A few single cell deaths or acidophilic bodies were variably noted. Most of these cells showed signals by in situ nick end-labeling in their nuclei, implying the cells were undergoing apoptosis. The number of apoptotic hepatocytes increased as the progress and decreased with the regression of acute rejection in group 3. Thus, the extent of hepatocytic apoptosis may reflect the magnitude of acute rejection. More frequent distribution of apoptotic hepatocytes in periportal areas suggests that apoptosis may be induced by a variety of pathological stimuli, including the direct cytotoxic effects of lymphocytes, various cytokines and local circulatory disturbances.     

Effect of voluntary exercise on maximal oxygen uptake in young female Fischer 344 rats

The effect of voluntary exercise on maximal oxygen uptake (VO2 max) was studied in young female Fischer 344 rats. After 10 weeks of wheel-running training, the absolute VO2 max and VO2 max relative to body mass increased without a decline in body mass. The running speed eliciting VO2 max, heart and soleus muscle mass, and succinate dehydrogenase (SDH) activity in the soleus muscle also increased. These results suggest that voluntary exercise is an effective means of increasing the aerobic exercise capacity of young female Fischer 344 rats.     

Receptors on chicken erythrocytes for F42 fimbriae of Escherichia coli isolated from pigs

Haemagglutination of purified F42 fimbriae was found to be inhibited by N-acetyl-galactosamine. Purified F42 fimbrial adhesin reacted with distinct membrane components from chicken erythrocytes (35, 37 and 40 kDa) in immunoblot analysis, suggesting that the binding occurred to proteins or glycoproteins.     

Rapid sensing of trace ionic substances with the novel porous monolith type ion exchanger

Biological and chemical sensor with a rapid response in microlevel test is required for health and environmental monitor. A novel sensing due to porous ion exchanger with three-dimensional acceptor has been first attempted to develop a high-performance sensor. This porous monolith type ion exchanger has an open-cellular monolith structure with 5–50-μm diameter pores. The trace amount of inorganic ions dissolved in aqueous solutions can be quantitatively determined with the impedance given by the monolith, which attracts and adsorbs the ions rapidly. We have succeeded in detecting ions with a concentration as low as 10⁻⁷ mol. The porous ion exchanger has a potentiality as a high-performance device for biological and chemical sensing. POLYM. ENG. SCI., 47:1666–1670, 2007. © 2007 Society of Plastics Engineers     

Recovery of neutron-induced damage of SiC by thermal annealing up to 1400 °C

Recovery of the specimen length of neutron-irradiated SiC was observed using a precision dilatometer. The specimens were heated isothermally and isochronally. The accuracy of length measurement at high temperature using the dilatometer was compared with that of length measurement at room temperature using a micrometer. It was clarified that the dilatometer method showed high accuracy and stability. The dilatometer method was applied to observe length recovery by isothermal annealing at 1200 °C of the neutron-irradiated SiC, and at least two recovery rates were clarified.     

Two-dimensional numerical simulation of side-gating effect in GaAsMESFETs

Two-dimensional device simulations that confirm that the side-gating effect in GaAs MESFETs occurs on semi-insulating substrates containing hole traps are discussed. A negative voltage applied on a side gate, a separate n-type doped region, causes an increase in the thickness of the negatively charged layer at the FET channel interface in the substrate, through hole emission from hole traps. The FET channel current is modulated by the electron depletion of the n-type channel, which results from the compensation for the extension of the negatively charged layer at the n-i interface into the i-substrate containing hole traps. The magnitude of the drain current reduction is determined by the total acceptor concentration in the substrate and the donor concentration of the channel. However, the magnitude is independent of the side-gate distances