High Temperature Uniaxial Compression and Stress–Relaxation Behavior of India-Specific RAFM Steel

India-specific reduced activity ferritic martensitic steel (INRAFM), a modified 9Cr-1Mo grade, has been developed by India as its own structural material for fabrication of the Indian Test Blanket Module (TBM) to be installed in the International Thermonuclear Energy Reactor (ITER). The extensive study on mechanical and physical properties of this material has been currently going on for appraisal of this material before being put to use in the ITER. High temperature compression, stress–relaxation, and strain-rate change behavior of the INRAFM steel have been investigated. The optical microscopic and scanning electron microscopic characterizations were carried out to observe the microstructural changes that occur during uniaxial compressive deformation test. Comparable true plastic stress values at 300 °C and 500 °C and a high drop in true plastic stress at 600 °C were observed during the compression test. Stress–relaxation behaviors were investigated at 500 °C, 550 °C, and 600 °C at a strain rate of 10^?3 s^?1. The creep properties of the steel at different temperatures were predicted from the stress–relaxation test. The Norton’s stress exponent (n) was found to decrease with the increasing temperature. Using Bird–Mukherjee–Dorn relationship, the temperature-compensated normalized strain rate vs stress was plotted. The stress exponent (n) value of 10.05 was obtained from the normalized plot. The increasing nature of the strain rate sensitivity (m) with the test temperature was found from strain-rate change test. The low plastic stability with m ~ 0.06 was observed at 600 °C. The activation volume (V^*) values were obtained in the range of 100 to 300 b³. By comparing the experimental values with the literature, the rate-controlling mechanisms at the thermally activated region of high temperature were found to be the nonconservative movement of jogged screw dislocations and thermal breaking of attractive junctions.     

Relationship between adenovirus-mediated aquaporin 1 expression and fluid movement across epithelial cells

AdhAQP1, a recombinant adenovirus encoding the human water channel aquaporin 1 (AQP1), has been shown to be useful for gene therapy of salivary glands rendered hypofunctional following irradiation. Here we utilized AdhAQP1 to examine the relationship between AQP1 expression and fluid movement across a polarized salivary epithelial cell monolayer. In response to a 440 to 340 mosm gradient, net fluid movement across cells infected with AdhAQP1 was approximately 10-fold that seen in uninfected cells or cells infected with a control virus. At a multiplicity of infection (MOI) of 5, fluid movement was linear for 15-30 min. Increasing the osmotic gradient resulted in a proportional increase in fluid movement. At low virus MOIs (0.1-1.0), fluid movement was markedly enhanced relative to that seen at higher MOIs (approximately 5.10), where the level of AQP1 expression and number of cells transduced were considerably greater. We conclude that significant, osmotically-obliged fluid movement in a salivary cell monolayer with low basal water permeability does not require high levels of AQP1 expression.     

Nanotribological characterization of perfluoroalkylphosphonate self-assembled monolayers deposited on aluminum-coated silicon substrates

Aluminum-coated silicon substrates are commonly used for various micro/nanooptoelectromechanical systems (MOEMS/NOEMS) including Digital Micromirror Devices (DMD^®). For efficient and failure proof operation of these devices, ultra-thin lubricant films of self-assembled monolayers (SAMs) are increasingly being employed. Fluorinated molecules are known to exhibit low surface energy, adhesion, and friction, desirable for tribological applications. In this study, we investigate contact angle, surface energy, friction, adhesion, and wear properties of a perfluoroalkylphosphonate SAM and compare them with those of alkylphosphonate SAMs. The influence of relative humidity, temperature, and sliding velocity on the friction and adhesion behavior is studied. Failure mechanisms of SAMs are investigated by wear tests. These studies are expected to aid in the design and selection of proper lubricants for MOEMS/NOEMS.     

An alternative model for integrated vendor–buyer inventory under controllable lead time and its heuristic solution

Researchers have given a lot of attention to the integrated vendor–buyer problem. Both deterministic and stochastic models on the subject are available in the literature. Most of the models have appeared with the need and requirement of a Just-in-Time (JIT) system environment. The close tie between a vendor and a buyer helps to deliver products in a shorter lead time with reduced inventory cost. Based on this idea, recently, some researchers have presented such a stochastic model with equal sized batch (part of a lot) transfer under controllable lead time. They have shown that their model provides a lower total cost for a numerical problem. To enrich the JIT system literature, considering transportation cost of a batch, this article develops an alternative model of the problem with equal or unequal sized batches transfer under controllable lead time. Then it develops a heuristic solution technique of the model and applying it solves the same numerical example to show a reasonable cost reduction.     

Task sensitivity in EEG biometric recognition

This work explores the sensitivity of electroencephalographic-based biometric recognition to the type of tasks required by subjects to perform while their brain activity is being recorded. A novel wavelet-based feature is used to extract identity information from a database of 109 subjects who performed four different motor movement/imagery tasks while their data were recorded. Training and test of the system was performed using a number of experimental protocols to establish if training with one type of task and tested with another would significantly affect the recognition performance. Also, experiments were conducted to evaluate the performance when a mixture of data from different tasks was used for training. The results suggest that performance is not significantly affected when there is a mismatch between training and test tasks. Furthermore, as the amount of data used for training is increased using a combination of data from several tasks, the performance can be improved. These results indicate that a more flexible approach may be incorporated in data collection for EEG-based biometric systems which could facilitate their deployment and improved performance.     

Trace metal contents in barbeque (BBQ) charcoal products

In this study, the concentrations of trace elements contained in solid barbeque (BBQ) charcoal products have been investigated. Eleven brands of charcoal products were analyzed, consisting of both Korean (3 types) and imported products (eight types from three countries) commonly available in the Korean market places. The concentrations of trace metals in solid charcoal varied widely across metal types and between samples with the overall range of 5 μg kg(-1) (As) to 118 mg kg(-1) (Zn). The patterns of metal distribution between different products appeared to be affected by the properties of raw materials and/or the processes involved in their production. Although concentrations of certain trace metals were significantly high in certain charcoal samples, their emission concentrations were below legislative guidelines (e.g., the permissible exposure limit (PEL) set by the Occupational Safety and Health Administration (OSHA)). In light of the potential harm of grilling activities, proper regulation should be considered to control the use of BBQ charcoal from a toxicological viewpoint to help reduce the potential health risks associated with its use.     

New concepts for the assessment of concrete slab interfacial effects in pavement design and analysis

For many years, concrete pavement construction, whether new or overlay, has been done with a variety of layer interfaces ranging from strongly cemented having a high degree of shear strength to completely unstabilised having only internal frictional resistance between the individual particles. In this regard, both past and present design methodologies have been limited in their capability to address the bond between the slab and the underlying layers – essentially considering either unbonded or fully bonded conditions for design purposes. However, this limitation ignores a wide range of partially bonded conditions that can exist between these two limits that may consist of a variety of combinations of different levels of friction and adhesion. For most instances of design, unbonded conditions are principally hypothetical where qualification of the amount of adhesive strength and frictional restraint that develops along the interface between the slab and the underlying layer is the key to the characterisation of slab behaviour resulting in varying degrees of partial bond. This paper addresses a framework to model the effects of the concrete pavement slab–subbase interface for design purposes based on research relative to these and other factors as they may pertain to the prediction of short- and long-term performance.     

Fatty acids of boal fish oil by urea fractionation and gas-liquid chromatography.

The fatty acid composition of body and liver fats of boal, Wallago attu (Schn.), a cat fish, belonging to the family Siluridae and commonly known as fresh-water shark has been determined by urea fractionation and gas–liquid chromatography (g.l.c.). The percentages of major component acids were found to be, 16:0, 10.5; 16:1 ω9, 7.6; 18:0, 7.2; 18:1 ω9, 17.4; 18:2ω9, 8.4; 18:3ω3, 6.1; 20:4ω3, 3.7 and 22:6ω3, 4.4. In addition, a number of minor component acids have been detected and estimated. The liver oil fatty acids have also been determined without fractionation and the percentages of major component acids found were 16:0, 23.5; 18:0, 12.7; 18:1ω9, 7.0; 20:4ω3, 13.7; 22:6ω3, 11.2. The oil has been studied for the first time for its fatty acid composition.     

Phenolic acids in fresh and retted jute plants (Corchorus capsularis and Corchorus olitorius)

Fresh and retted bark and stem of the Corchorus capsularis and Corchorus olitorius species of jute plant were analysed for their phenolic acid contents. Free and bound phenolic acids were identified and quantitatively determined by means of HPLC. Ferulic and p-coumaric acids were the main components, whereas p-hydroxybenzoic, protocatechuic, vanillic and caffeic acids were present in varying amounts in different jute fractions. The stem contained more free phenolic acids than the bark, and the differences were very pronounced in the retted samples. On the other hand, the bark from all four samples contained more extractable ester-bound phenolic acid than the stem. The stem of fresh C. olitorius and retted bark (fibre) of both species contained more non-extractable bound phenolic acids, in particular p-coumaric acid, than the other fractions.