Erosion-corrosion of 2205 duplex stainless steel in flowing seawater containing sand particles

2205 duplex stainless steel (UNS S31803) was tested in flowing artificial seawater containing sand particles using a jet impingement apparatus. Erosion-corrosion was measured under a range of hydrodynamic conditions by recording the increase in anodic current density that occurred when the passive film was damaged by particle impacts. The current density increase was shown to be linearly related to the mean kinetic energy of the sand particles. When the stainless steel was held at anodic potentials the surface oxide film developed optical interference colours and these colours were used to identify the film thickness. The highest rate of erosion-corrosion occurred in the stagnation region, immediately beneath the jet, where the particles impacted the surface at angles close to 90°. The results are discussed in terms of the rates of particle impacts and their effects on the processes of film damage and repassivation.     

Reactivity control technique for a pressurized water reactor with an inventive TRISO fuel particle composition

In this research paper a reactivity control technique has been suggested for the conceptual design of a compact sized pressurized water reactor (PWR) core with an inventive tristructural-isotropic (TRISO) fuel particle composition. This conceptual design is a light water cooled and moderated reactor which utilizes TRISO fuel particles in PWR technology. The use of TRISO fuel in PWR technology improves integrity of the design due to its fission fragments retention ability. The fuel provides first retention barrier within fuel itself against the release of fission fragments that makes this design concept safer and environment friendly. The suggested TRISO fuel particle composition has a small amount of Pu-240 with 2.0 w/o in the place of U-238 which acts as reactivity suppressor. Reactor codes WIMS-D/4 and CITATION have been used for simulation and core design modeling. Results reveals that the amount of excess reactivity can be reduced significantly by using a small amount of Pu-240 in TRISO fuel which in turns reduces the number of gadolinia rods in the core required for excess reactivity control and completely eliminates the requirement of soluble boron system. Therefore the effective and optimal use of reactivity suppressor and burnable poison suppresses and flattens the core excess reactivity throughout the core life and hence number of control rods can be reduced without compromising on the shutdown margin.     

Influence of detoxified Indian vetch (Lathyrus sativus L.) on sensory and protein quality characteristics of composite flour chapatti

We studied the effects of different processing treatments, including soaking, steeping, boiling in water and germination and chemical treatments with H₂SO₄, HCl, lime and NaHCO₃, on the removal of a neurotoxin, β‐N‐oxalyl‐L ‐α,β‐diaminopropionic acid (β‐ODAP), from Indian vetch (Iv) and addition of detoxified Iv in chapatti. The toxin level was quantified by using thin‐layer chromatographic and spectrophotometric methods. Maximum removal was observed after steeping in water at 60–70°C for 8 h with seven rinses. The samples were dried, milled into flour and added to chapatti at different levels. Sensory attributes revealed that the chapattis were most acceptable by judges when supplemented with up to 200 g kg⁻¹ of flour. The protein level of Iv flour increased from 124 to 174 g kg⁻¹ as result of supplementation at 300 g kg⁻¹. Biological studies with albino rats showed that detoxified Iv had a better impact on nutritional status. Copyright © 2006 Society of Chemical Industry     

Pavement Roughness Modeling Using Back-Propagation Neural Networks

Abstract:   Quantifying the relationship between material and construction (M&C) variables and pavement performance is an on-going important research area. It is, however, realized that deriving such relationships is too complex and too poorly understood to develop using traditional statistical methods. Therefore, this study is focused on the analysis of a data set from the long-term pavement performance (LTPP) database to quantify the contribution of M&C variables of asphalt concrete on pavement performance (i.e., international roughness indicator) using a back-propagation neural network (BPNN) algorithm. It was found that by using sensitivity analysis neural network trained with optimal number of epochs could be used effectively for better understanding of the factors controlling overall performance indicators, establishing quantitative functions to weigh the role of such factors, and for use in performance-related specifications.     

Influence of second-phase particles on plastic deformation and lattice reorientation of single crystals during uniaxial compression

Changes in the orientation of crystal axes of Al-0.8 wt% Si single crystals in the presence of two different particle sizes and inter-particle spacings were investigated during uniaxial compression. The orientation of crystal axes before and after deformation was precisely determined by the diffractometer method in the unit triangle of the stereographic projection. The reorientation of the compression axes after deformation was found to be influenced by particle size and initial orientation of the undeformed crystals. It was found that particle size also influenced the yield strength and work-hardening characteristics which was explained on the basis of Orowan stresses and solid-solution strengthening.     

X-ray Crystallinity Studies of Palladium Polyacrylate

Free radical polymerized palladium polyacrylate was characterized by X-ray diffraction. Various parameters including mean crystallite size, interchain separation and radius of gyration have been calculated and discussed with respect to the concentration of Pd in the polymeric salt. The results show that polymer is predominantly amorphous in nature.     

Intragenic mutations of the p16(INK4), p15(INK4B) and p18 genes in primary non-small-cell lung cancers

The p15(INK4B), p16(INK4) and p18 genes are members of the gene family coding for inhibitors of cyclin-dependent kinases 4 and 6. p15(INK4B) and p16(INK4) are located at 9p21, a chromosomal region frequently deleted in many human neoplasms. To examine the role of these 3 genes in lung carcinogenesis, somatic mutations within the genes were analyzed by single-strand conformation polymorphism and DNA sequencing in 71 non-small-cell lung cancer (NSCLC) samples. Six somatic mutations in the p16(INK4) gene and 3 cases with a polymorphic allele were observed. Loss of heterozygosity in the p18 gene was found in 1 sample. We did not find any intragenic mutations in the p15(INK4B) or p18 genes. We conclude that p16(INK4) mutations play a role in the formation of some NSCLCs, whereas the involvement of p15(INK4B) and p18 is uncommon.     

Lattice changes in the martensitic phase due to ageing in 18 wt% nickel maraging steel grade 350

Changes in the lattice parameter of martensite phase in a maraging steel is measured as a function of ageing temperatures. A decrease in the lattice parameter is observed when aged between 400–650°C which is attributed to the depletion of alloying elements in the martensite matrix as a consequence of precipitation and austenite formation. An increase in the lattice from 650 to 710°C was characteristic of enrichment of alloying elements in the martensite matrix due to dissolution of austenite phase. A minimum value of the lattice parameter of martensite is observed at 650 °C which coincides with the maximum vol % of retained austenite. Electrical resistivity, hardness measurements, andin situ high temperature dilatometry was also carried out to delineate various precipitation reactions that occur in this steel.[/p]     

High-Temperature Oxidation Behavior of HASTELLOY C-4 in Steam

A commercial superalloy HASTELLOY C-4, was studied to evaluate its resistance to oxidation at elevated temperatures. Specimens were exposed to steam from 600° to 1200°C for 1–400 hr. The reaction kinetics of oxidation were determined, and the morphology of the oxide scales was investigated by optical and scanning-electron microscopy. It was observed that C-4 exhibited excellent oxidation resistance at all temperatures under study. This behavior is due to the formation of a compact and adherent oxide. The oxides formed during oxidation were identified by X-ray diffraction. The oxides observed were mainly Cr₂O₃, NiCr₂O₄, NiCrMnO₄, FeCr₂O₄ and (Cr, Fe)₂O₃.     

Controlled study of fluconazole in the prevention of fungal infections in neutropenic patients with haematological malignancies and bone marrow transplant recipients

The efficacy and safety of oral fluconazole versus a polyene regimen in preventing mycoses in neutropenic patients was compared. Patients with haematological malignancy or bone marrow transplantation received as antifungal prophylaxis either fluconazole 200 mg daily or a regimen consisting of clotrimazole trouches 10 mg twice daily with mycostatin, 500,000 I.U. four times daily, benadryl and cepacol mouthwash. Ninety patients at risk for fungus infection were evaluable. Four of 42 patients (9.5%; confidence interval 2%-23%) on fluconazole and 17 of 48 patients (35.4%; confidence interval 22%-52%) (p < 0.01) on the clotrimazole regimen developed a clinically significant fungal infection, including 3 (7.1%) and 11 (22.9%) patients respectively who had severe fungal infection, mainly pulmonary aspergillosis. Death directly due to a fungal infection within 100 days of the start of prophylaxis occurred in 2 of 42 patients (4.8%) and 9 of 48 patients (18.8%) respectively (p < 0.06). Kaplan-Meier analysis showed that the chance of survival on fluconazole was statistically greater than for the clotrimazole regimen (p < 0.04). A decrease of candidal colonisation of the gastrointestinal and genitourinary tracts occurred only in patients receiving fluconazole. No significant toxicity occurred. A 200 mg daily dose of fluconazole given to these patients thus appears to be well tolerated and to provide a protective effect against the development of fungal infection and death from severe fungal disease.