Pressure corrections for viscous potential flow analysis of radial fingering in Hele-Shaw cell

The principal problem of interest in this article is that of the area-preserving azimuthal shear strain of an incompressible isotropic hyper-elastic circular cylindrical tube subjected to homogeneous radial tractions on its both inner and outer boundaries. Pure azimuthal shear strain may be considered as a particular case of the present deformation. However, in the present case, equilibrium requires a change of the inner and the outer tube boundaries which, due to the incompressibility constraint, may take place only in a manner that preserves the area of the tube cross section. Nevertheless, it is assumed that the tube retains its circular cylindrical shape. A considerable part of the solution to this problem is described analytically, but the final part requires numerical treatment; the balance between these two parts depends on the specific form of the strain energy density of the material. An appropriately modified version of the outlined method of solution may be further used for solving the generalized counterpart of this plane strain problem, where the radial tractions applied on the inner and the outer boundaries of the tube are not necessarily homogeneous.     

Centralized fleet management system for cybernetic transportation

In this article, we present a centralized fleet management system (CFMS) for cybernetic vehicles called cybercars. Cybercars are automatically guided vehicles for passenger transport on dedicated networks like amusement parks, shopping centres etc. The users make reservations for the vehicles through phone, internet, kiosk etc and the CFMS schedules the cybercars to pick the users at their respective stations at desired time intervals. The CFMS has centralized control of the routing network and performs pooling of customer requests, scheduling and routing of cybercars to customers, empty cybercars to new services or parking stations and those running below their threshold battery levels to recharging stations. The challenges before CFMS are to assure conflict-free routing, accommodate immediate requests from customers, dynamic updation of vehicle paths and minimize congestion on the whole network. We present the approaches used by CFMS to ensure these functionalities and demonstrate a numerical illustration on a test network.     

Effect of chromium on the level of IL-12 and IFN-gamma in occupationally exposed workers

Chromium may affect humoral and cellular immunity, acting on T lymphocytes as well as on granulocytes and monocytes cells. Cytokines play an important role in the immune balance. In this study, the level of IL-12 and IFN-γ were evaluated in the sera and PHA/LPS stimulated culture supernatant of human PBMCs of healthy volunteers and occupationally exposed chromium workers. All the workers were highly exposed to chromium having mean of 104.65 ± 77.21 µg/dL (range 23.7-316.8 µg/dL). A suspension of exposed and unexposed human PBMC (0.5 × 10⁶ cells/ml) prepared and cultured in RPMI-1640 supplemented with 10% FCS for 18 h in the presence or absence of LPS (10 ng/ml) which used for stimulation of IL-12 and IFN-γ. The level of IL-12 and IFN-γ were evaluated in the sera samples as well as LPS stimulated and unstimulated culture supernatant of h-PBMCs of chromium exposed workers. In these chromium exposed workers the level of IL-12 was 433.66 ± 197.49 pg/ml and 983.45 ± 330.99 pg/ml in LPS stimulated culture supernatant of normal individuals and highly chromium exposed workers, which was significant (P < 0.05). Although the level of IL-12 was (78.61 ± 61.03 pg/ml to 146.52 ± 46.37 pg/ml) elevated in unstimulated culture supernatant of h-PBMCs of chromium exposed individuals as compared to control, but it was not significant. This observation also suggests that a significant increase in IFN-γ production in LPS stimulated and unstimulated culture supernatant of h-PBMCs of chromium exposed workers as compared to control. However, IFN-γ level have a significant positive correlation between blood chromium level (r = 0.833, t = 6.3872, P 0.05) and exposure time (in years) (r = 0.8916, t = 8.3540, P 0.05) of the occupationally exposed workers.     

Modified Glasgow Coma Scale to predict mortality in children with acute infections of the central nervous system

BACKGROUND: This study aimed to identify the predictors of hospital mortality in children with acute infective disorders of the central nervous system using an aggregate Modified Glasgow Coma Scale (MGCS) score and other clinical variables assessed within 24 hours of hospitalization. METHODS: We did a prospective cohort study in a teaching and referral hospital in Lucknow, North India. Consecutive children aged 1 month to 12 years of age admitted with acute infective disorders of the central nervous system were included in the study. The diagnosis was based on the presence of symptoms of fever, headache or irritability with or without vomiting, and either altered sensorium or first episode of seizures or both. The main outcome measure was hospital-based mortality. RESULTS: Of the 230 patients included in the study, 42.2% had pyogenic meningitis, 36.9% had tuberculous basal meningitis and 20.9% had meningo-encephalitis. There were 43 (18.7%) deaths of which 44.2% were within 3 days of admission. Death was associated with the day 1 aggregate MGCS score only. The area under the curve of four strata of aggregate MGCS was 0.63 (SE 0.05). The likelihood ratio for discharge with an aggregate MGCS score of < 5 was 0.52 (95% CI:0.29-0.95) and > 10 was 5.52 (9% CI:1.02-31.96). CONCLUSION: The MGCS can be used to predict discharge in patients with acute infective disorders of the central nervous system within 24 hours of hospitalization. The scale is simple, can be applied at the bedside and does not depend on any investigations. In developing countries with limited investigative facilities it can be used for identification and selective referral of patients with a higher risk of death to specialized centres. This study validates the predictive value of the MGCS.     

Structural, optical, thermo-mechanical and transport properties of ion irradiated polymer membranes

Summary The modifications in PET induced by swift heavy ion irradiation are analyzed. PET membrane of 15 μm was irradiated by Cl⁹⁺ ions of 100 MeV at TIFR Mumbai. The changes due to exposure to high-energy ions were investigated by Fourier Transform Infrared (FTIR) and Ultraviolet/ Visible absorption (UV/VIS) spectroscopies, X-Ray diffraction technique, dynamic mechanical analysis and by the gas permeation. A significant loss of crystallinity is observed by the XRD data. Particle size or grain size calculated using Scherrer formula indicates measurable change in particle size of irradiated samples. The polymer chain scissions and structure degradations are expected to occur for irradiated samples. Optical properties of the films were changed due to irradiation that could be clearly seen in the absorption and FTIR spectra. Gas permeation through these membranes before and after irradiation using hydrogen and carbon dioxide gases shows that permeability for both gases increased after irradiation but permeability for hydrogen is higher than carbon dioxide due to its small molecular size.     

Application of fuzzy TOPSIS in evaluating sustainable transportation systems

Sustainable transportation systems are the need of modern times. There has been an unexpected growth in the number of transportation activities over years and the trend is expected to continue in the coming years. This has obviously associated environmental costs like air pollution, noise, etc. which is degrading the quality of life in modern cities. To cope us this crisis, municipal administrations are investing in sustainable transportation systems that are not only efficient, robust and economical but also friendly towards environment. The challenge before the transportation decision makers is how to evaluate and select such sustainable transportation systems. In this paper, we present a multicriteria decision making approach for selecting sustainability transportation systems under partial or incomplete information (uncertainty). The proposed approach comprises of three steps. In step 1, we identify the criteria for sustainability assessment of transportation. In step 2, experts provide linguistic ratings to the potential alternatives against the selected criteria. Fuzzy TOPSIS is used to generate aggregate scores for sustainability assessment and selection of best alternative. In step 3, sensitivity analysis is performed to determine the influence of criteria weights on the decision making process. A numerical illustration is provided to demonstrate the applicability of the approach.The strength of the proposed work is its practical applicability and the ability to generate good quality solutions under uncertainty.     

Using fast atomic source and low-energy plasma ions for polymer surface modification

A systematic study was carried out to characterize the effects of argon atomic beam irradiation and low-energy argon ions in plasma for polystyrene (PS) surface modification. The PS samples were exposed to a 1.5 keV, argon atomic beam from a fast atomic source (FAS) at different exposure times. The low-energy (1.5 eV) argon plasma ions were achieved in a two-stage RF discharge and PS samples were exposed to plasma for different times and powers. The surface characterization of these atomic beam and plasma modified PS samples was carried out using X-ray photoelectron spectroscopy. For FAS, the results showed a rapid increase (from 0.01 to 0.18) in oxygen-to-carbon ratio (O/C) at the surface of PS with first 10 s exposure time while further increase in exposure time up to 500 s showed about 50% decrease in O/C. Therefore, first few seconds of atomic beam irradiation useful to increase the O/C at the PS surface whereas at higher irradiation time the surface etching may took places and it could have advantage in surface cleaning. A comparison of O/C with FAS and plasma ions showed FAS is more effective way to achieve oxygen incorporation at PS surface relatively to low-energy flux plasma ions.     

Microporous Hydroxyapatite Ceramic Composites as Tissue Engineering Scaffolds: An Experimental and Computational Study

Bone‐tissue engineering mandates the development of multi‐functional bioactive porous hydroxyapatite (HAp) scaffolds. Herein, microwave sintered HAp/ZnO and HAp/Ag composite scaffolds with ≈5–19% porosity are developed using 0–30 vol% graphite as a porogen. The mechanical properties of the porous scaffold are analyzed in detail, revealing that even being more porous, the reinforcement of ZnO (9% porosity, hardness of 2.8 GPa, and toughness of 3.5 MPa.m^1/2) has shown to have better hardness and fracture toughness when compared to Ag (5% porosity, hardness of 1.6 GPa, and toughness of 2.6 MPa.m^1/2). The flexural strength obtained experimentally are complemented with a finite‐element technique that adopts microstructural features in visualizing the effect of porosity on stress distribution. The antibacterial efficacy and cytocompatibility of these composites are validated by increased metabolic activity and conspicuous cell‐matrix interactions. The anticipation of the results reveal that HAp/ZnO (9% porosity) and HAp/Ag (5% porosity) composites can be used as a potential multi‐functional bone implant scaffolds.