Influence of tungsten–carbon mixed layer and irradiation defects on deuterium retention behavior in tungsten

The D₂⁺ fluence dependence on deuterium (D) retention was studied to clarify the D retention mechanism in tungsten. The additional D desorption stage was observed around 660 K in the TDS spectrum for a sample implanted with D₂⁺ up to the fluence of 10²³ D⁺ m^?2, which desorption stage was not observed the D₂⁺ implanted sample with the fluence less than 10²² D⁺ m^?2. The TEM observation showed that the highly dense voids were formed in tungsten by D₂⁺ implantation with the fluence of 10²³ D⁺ m^?2, considering that the D would be trapped by voids. To understand the D trapping by voids in C⁺ implanted tungsten, C⁺–D₂⁺ sequential implantation experiments at various C⁺ implantation temperatures were performed. It was found that the amount of D desorbed around 560 K was increased by increasing the C⁺ implantation temperature. The formation of the voids was observed with increasing the C⁺ implantation temperature by TEM, indicating that the increase of D desorption around 560 K was caused by the formation of voids. However, the desorption temperature of D trapped by voids in C⁺ implanted sample was lower than that in D₂⁺ implanted one. TEM observation and XPS measurement indicated that this difference was caused by the increase of void size and/or the presence of implanted carbon.     

Use of solid phase microextraction (SPME) for profiling the volatile metabolites produced by Glomerella cingulata

The profile of volatile organic compounds (VOCs) released from Glomerella cingulata using solid phase microextraction (SPME) with different fibers, Polydimethylsiloxane (PDMS), Polydimethylsiloxane/Divinylbenzene (PDMS/DVB), Carboxen/Polydimethylsiloxane (CAR/PDMS) and Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), was investigated. C4-C6 aliphatic alcohols were the predominant fraction of VOCs isolated by CAR/PDMS fiber. Sesquiterpene hydrocarbons represented 20.3% of VOCs isolated by PDMS fiber. During the growth phase, Ochracin was produced in the large majority of VOCs. 3-Methylbutanol and phenylethyl alcohol were found in the log phase of it. Alcohols were found in cultures of higher age, while sesquiterpenes were found to be characteristic of initial growth stage of G. cingulata.     

Nickel/Zinc Chloride‐Promoted Domino Reaction of Enynes and Enones Including Unstrained C?C Bond Cleavage

Unstrained C C bond cleavage proceeds during the domino reaction of enynes and enones that includes successive C C bond formation under the nickel/zinc/zinc chloride system. The cleavage occurs through β‐syn‐elimination of the 1,3‐dicarbonyl part. In addition, β‐carbon elimination is selective, unlike the β‐hydrogen elimination in the presence of excess zinc chloride.     

Deuterium trapping by irradiation damage in tungsten induced by different displacement processes

The deuterium trapping behaviors in tungsten damaged by light ions with lower energy (10 keV C⁺ and 3 keV He⁺) or a heavy ion with higher energy (2.8 MeV Fe²⁺) were compared by means of TDS to understand the effects of cascade collisions on deuterium retention in tungsten. By light ion irradiation, most of deuterium was trapped by vacancies, whose retention was almost saturated at the damage level of 0.2 dpa. For the heavy ion irradiation, the deuterium trapping by voids was found, indicating that cascade collisions by the heavy ion irradiation would create the voids in tungsten. Most of deuterium trapped by the voids was desorbed in higher temperature region compared to that trapped by vacancies. It was also found that deuterium could accumulate in the voids, resulting in the formation of blisters in tungsten.     

Study on numerical design method of frozen inert gas plasma MHD generators

A numerical design method to determine basic specifications of high-performance frozen inert gas plasma (FIP) MHD generators is proposed. To validate the proposed method, time-dependent, two-dimensional (r-z)MHD numerical analyses are performed for several FIP MHD generators with different thermal inputs (30, 100, 300, or 1000 MW) designed by the proposed method. The numerical results indicate that the designed FIP MHD generators with the thermal input of 100 MW or more are able to be operated with the performance approximately same as the designed one. For the designed MHD generator with the thermal input of 30 MW; however, the performance shown by the MHD numerical analysis is considerably lower than the designed one. For such a case, the performance can be improved by operating the MHD generator under an applied magnetic flux density larger and an inlet ionization degree lower than those designed values.     

The grindability and wear of Ti-Cu alloys for dental applications

To optimize the properties of titanium for use in dentistry, alloying is necessary. This study reports on the characterization of some titanium alloys for grindability, wear, and corrosion resistance. Improvements in grindability and wear seemed to occur with the presence of the eutectoid in the alloy. For more information, contact Toru Okabe, Baylor College of Dentistry, Dept. of Biomaterials Science, 3302 Gaston Ave., Dallas, TX 75246; (214) 828-8190; fax (214) 828-8458; e-mail tokabe@tambcd.edu.     

Interleukin 12 augments the liver-associated immunity and reduces liver metastases

BACKGROUND/AIMS: It has been reported recently that in vivo administration of interleukin-12 (IL-12) augments the cytotoxic activity of natural killer (NK)/T cells and shows a powerful anti-tumor activity. In this study, we evaluated that the IL-12 effect on liver-associated immunity and in vivo efficacy on the hepatic metastases in a rat model. MATERIALS AND METHODS: Varying amounts of mouse recombinant IL-12 were injected intraperitoneally for 5 days to adult male Fischer rats and hepatic sinusoidal lymphocytes (HSL) were collected. Purified HSL are spontaneously cytolytic to both conventional NK-sensitive target (YAC-1) and NK-resistant target (RCN-H4) tumor cells. RESULTS: IL-12 was found to increase the number of HSL and the cytolytic activity against these target cells in a dose-dependent fashion. Flow cytometric analysis showed that IL-12 caused an increase of CD8+ subpopulation in HSL and a double staining study revealed that the increased subpopulation was not CD3+8+ (cytotoxic T cell) fraction, but actually CD3-8+ (NK cell) fraction. Experimental liver metastases was markedly reduced in rats treated intraperitoneally with IL-12. CONCLUSION: These results demonstrate that IL-12 augments the cytolytic activity of HSL and suggests this cytokine as an attractive choice for liver metastases therapy.