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Notes: We investigated the effect of C49-to-C54 conversion behavior on the agglomeration of Ti-silicide fabricated on subquarter micron polycrystalline Si lines by comparing pre-amorphized samples with conventional ones. Pre-amorphization of polycrystalline Si enhances the C49-to-C54 transformation on subquarter micron linewidths, however, it results in the early development of macroscopic grooves during the second rapid thermal annealing. From these results, we suggest the existence of an extra thermal budget during the second rapid thermal annealing of the pre-amorphized samples, which deteriorates the thermal stability of the C54-TiSi2 featured line. It is also shown that C49-to-C54 transformation on a 0.2 μm linewidth in the conventional samples has two kinds of competing factors when postannealing is added. One is the tendency of C54 transformation and the other is agglomeration of C49-TiSi2 grains. During high temperature annealing (〉850 °C), C49-TiSi2 has been agglomerated by a thinning mechanism instead of transformation into the C54 phase. © 1999 American Institute of Physics.

Notes: This letter describes the use of rapid thermal annealing (RTA) to form a barrier layer applicable to the gate electrode in dynamic random access memory devices with a stacked structure [tungsten nitride (WNx)/polycrystalline Si (poly-Si)]. After RTA, the reactively sputtered amorphous WNx film on the poly-Si was transformed to a low-resistive α-phase W and nitrogen-segregated layer. Most of the nitrogen in the WNx film was dissipated and a relatively small amount of the nitrogen was segregated at the interface of the α-phase W and poly-Si. The segregated layer was estimated to be 2 nm thick and revealed a silicon nitride (Si–N) bonding status. More importantly, we found that this thin segregated layer successfully protected the formation of tungsten silicide, even after RTA at 1000 °C for 2 min in a hydrogen environment. © 2000 American Institute of Physics.

Notes: Abstract  Background:  Chronic bacterial prostatitis (CBP) is the most common urological disease in adult men. Antibiotic therapy is the gold standard of treatment. However, long-term therapy resulted in many side-effects and bacterial resistance. Because of these reasons, we need new treatment modality that could replace traditional antibiotic therapy. Catechin, an extract of green tea, has antimicrobial effect against various bacteria and synergy effect to antibiotics. We evaluate the synergistic effects of catechin on the treatment of CBP in an animal model.Methods:  An experimental CBP model was induced in 70 male Wistar rats by instillation of 0.2 mL bacterial suspension (E-coli Z17, O2:K1:H-) containing 1 × 108 CFU/mL into the prostatic urethra. Microbiologically and histologically proven CBP model was demonstrated in 58.6% (41 of 70) of the rats after 4 weeks of bacterial instillation. The 41 rats demonstrating CBP were randomly divided into four groups; the control, catechin, ciprofloxacin and catechin with ciprofloxacin groups. All drug treatments were conducted over a period of 2 weeks. After treatment, the results were analyzed with microbiological cultures and histological findings of the prostate and urine samples to compare each group.Results:  Microbiological cultures and histological findings of the prostate and urine samples demonstrated reduced bacterial growth and improved inflammatory responses in all three experimental groups compared with the control group. The catechin group showed coherent trends of decrease in bacterial growth and improvements in prostatic inflammation compared with the control group, but not to a statistically significant degree (P 〉 0.05). However, the ciprofloxacin and catechin with ciprofloxacin groups showed statistically significant decreases in bacterial growth and improvements in prostatic inflammation compared with the control group (P 〈 0.05). The catechin with ciprofloxacin group showed a statistically significant decrease in bacterial growth and improvements in prostatic inflammation compared with the ciprofloxacin group (P 〈 0.05).Conclusions:  These results suggest that catechin may be an effective material in CBP treatment. Particularly, combination treatment of catechin and ciprofloxacin has synergistic effect. Therefore, we suggest that the combination of catechin and ciprofloxacin may be effective in treating CBP with a higher success rate.

Notes: Tensile and fatigue properties were evaluated for base and welded type 316LN stainlesssteel. Welding methods were GTAW (308L, Ar environment) and GTAWN (316L, Ar + N2environment). Yield strength of weld joint was higher than that of base metal but elongation of weldjoint was lower than that of base metal. UTS of weld joint was slightly lower than that of base metal.Yield strength and elongation with welding method were almost same. Fatigue life of weld jointwas lower than that of base metal but fatigue strength of weld joint was higher than that of basemetal. Ferrite content was increased with welding. Fatigue life welded by GTAWN was better thanthat of GTAW at RT and 600℃. This fatigue life behavior was consistent with the behavior offerrite content

Notes: The effects of thermal aging on microstructural evolution and mechanical properties areimportant in the understanding of the in-service behavior of ferritic/martensitic steels in advancednuclear power system. Ferritic/martensitic steels have been aged at 600oC for times up to 20,000 hrs.The change of mechanical properties has been examined for these aged materials. The strength andhardness was hardly changed after the thermal aging at 600oC for 20,000 hrs in all specimens. Theimpact absorbed energy decreased with the aging time. But the decrease of the impact absorbedenergy was larger at the early stage of aging in tungsten added steels. This is attributed to theformation of Laves phase. Nitrogen which is known to increase the creep rupture strength had noeffect on the degradation of the microstructure and mechanical properties during thermal aging

Notes: The precipitation of nano Cr2N particles in high Cr FM steels has been studied. Thenitrogen content of the FM steels was changed to form stable Cr2N particles. Tempering temperaturewas also changed from 500 oC to 800 oC to study the precipitation behavior of the Cr2N particles withthe tempering temperature. The Cr2N particles remained as a stable phase at a higher temperingtemperature by increasing the nitrogen content. The shape of these particle was a fine needle typewhich was very similar to V(C,N) particles. The size of some Cr2N particles was increased as thenitrogen content increased. But these precipitates were not dissolved or largely coarsened during acreep deformation at 600°C. So it seems that they may act as an effective obstacle against adislocation glide during a creep deformation, thus contribute to an increase of the creep rupturestrength in high Cr FM steels

Notes: Fatigue tests of type 316 and 316LN stainless steel were conducted at RT and 600ı,0.8~1.5% strain range for low cycle fatigue (LCF), 300~600ı, 0% strain range for thermal fatigue (TF) and 300~600ı, 2% strain range, in-phase or out-of-phase for thermomechanical fatigue (TMF). LCF, TF, and TMF lives were increased but saturation stresses were decreased with the addition of nitrogen. The higher temperature was the lower TF life at a same temperature change. The minimum temperature change for TF failure was more than 100ı. TMF life was higher at inphase condition than at out-of-phase condition. Fracture mode was transgranular for LCF and outof- phase of TMF and almost transgranular and small intergranular for TF and in-phase TMF

Notes: High Cr alloys were corrosion tested in supercritical water and the oxide scale wasanalyzed. Commercial grade two steel specimens; 9CrMoVNb steels, one 9CrMoVNbW steel, one 12Cr-MoVNbWCu steel and one 20Cr Fe-based O.D.S (Oxide Dispersion Strengthened) alloy specimen were investigated. Corrosion tests were conducted within non-deaerated pure supercritical water at 627, 550, and 500oC with 25 MPa. Corrosion rate was estimated by the weight change perunit surface area and the oxide layer was analyzed using a grazing incidence X.R.D (x-ray diffractometer), S.E.M (scanning electron microscope) and T.E.M (transmission electron microscope) equipped with an E.D.S (energy dispersive spectroscope). Corrosion rates of the 9Cr steel specimens were observed to follow the parabolic growth rate law, while those of the specimens with a 12 per cent or higher Cr content showed significantly lower rates. Oxide scale on the 9Cr steelspecimen after a corrosion test in a supercritical water was found to consist of three distinctive layers. Through the cross-section T.E.M the outermost layer with about a 35 µm thickness after 200 hr at 627 oC was identified to be magnetite type Fe3O4, and about 25 µm thick intermediate layer was a Cr partitioned magnetite type (Fe,Cr)3O4. The outermost layer showed a coarse columnar structure, while the intermediate one revealed an agglomerate of tiny oxide particles (several tens nm indiameter). The innermost layer next to the matrix phase was found to be the internally oxidized zone. Oxygen atoms seemed to have attacked along the grain boundaries and the lath boundaries and formed oxide CrO3 along the boundaries. Also a Cr depleted zone, and consequently a carbide-free zone, was observed along the interface between the internal oxidation zone and the matrix phase