Picosecond electronic time-gated imaging of bones in tissues

Two-dimensional in vivo optical images of metacarpal bones of a human palm and in vitro images of turkey and chicken bones embedded in tissues were obtained in the near-infrared region using femtosecond pulse transillumination and picosecond electronic time-sliced detection technique. A small hole drilled in chicken bone and embedded in chicken breast tissue was imaged using early arriving light. Time-gated fluorescence images of an interior marrow region of a bone injected with a fluorescent dye were recorded. The techniques have potential for monitoring bone fracture, bone diseases such as, osteoporosis and arthritis, and diseases that originate in or affect bone marrow     

High ferromagnetic transition temperature in PbS and PbS:Mn nanowires

Spontaneous magnetization measured in the temperature range 5-300 K with high ferromagnetic transition temperature (T(c)) has been observed in both undoped and Mn doped (2-8 mol %) PbS nanowires (diameter 30 nm) in polymer. For undoped sample, we find T(c) ~ 290 K while for doped samples T(c) varies between 310-340 K depending on Mn concentrations. Both T(c) and coercive fields are critically dependent on Mn concentrations. Coercive fields show a T(0.5) dependence with temperature for a moderate concentration of Mn (4 mol %) in PbS while it deviates from T(0.5) behavior for higher Mn concentrations. Anionic defects arising out of nonstoichiometric growth is solely responsible for the observed magnetism in undoped PbS nanowires. The role of intrinsic strain along with reduced dimensionality in determining such high T(c) and overall magnetizations has been discussed.     

Natural convection heat transfer and entropy generation inside porous quadrantal enclosure with nonisothermal heating at the bottom wall

In this work, we study numerically the natural convection heat transfer and entropy generation characteristics inside a two-dimensional porous quadrantal enclosure heated nonuniformly from the bottom wall. The effect of Darcy number is significant in dictating the Nusselt number only for higher values of Rayleigh number and the variation is more profound for larger values of Darcy number. The variation of entropy generation rate is significant with the Darcy number only for higher values of Rayleigh number. The entropy generation due to heat transfer is the significant contributor of irreversibility at low values of Darcy number, while for larger values of Darcy number and Rayleigh number entropy generation due to fluid friction becomes dominant.     

Analysis of Conduction-Radiation Heat Transfer in a 2D Enclosure Using the Lattice Boltzmann Method

Application of the lattice Boltzmann method (LBM) recently extended by Pietro et al. [P. Asinari, S. C. Mishra, and R. Borchiellini, A Lattice Boltzmann Formulation to the Analysis of Radiative Heat Transfer Problems in a Participating Medium, Numer. Heat Transfer B, 57(2), 126–146, 2010] for calculation of volumetric radiative information is extended for the analysis of a combined mode transient conduction and radiation heat transfer in a 2D rectangular enclosure containing an absorbing, emitting and scattering medium. Unlike all previous studies, with volumetric radiative information computed using the proposed LBM, the energy equation is formulated and solved using the LBM. In the combined mode conduction–radiation problem, to assess the computational advantage of computing the radiative information too using the LBM, the same problem is also solved using the LBM–finite volume method (FVM) formulation. In this LBM–FVM formulation, the FVM is used to calculate the volumetric radiative information needed for the energy equation, and the energy equation is solved using the LBM. Comparisons are made for the effects of the extinction coefficient, the scattering albedo and the conduction–radiation parameter on the temperature distributions in the medium. Although the number of iterations for the converged solution in LBM–LBM is much more than that of the LBM–FVM, computationally, the LBM–LBM is faster than the LBM–FVM.     

Sensory evaluation of black pigmented rice (Oryza sativa cv. Poireton) wine fortified with probiotic Lactobacillus acidophilus ATCC 4356 and Lactobacillus sakei ATCC 15521 using fuzzy logic

Rice wine was prepared in the laboratory from a black pigmented rice (cv. Poireton) using standardized methodology. The wine was fortified with the probiotic strains Lactobacillus acidophilus ATCC 4356 and Lactobacillus sakei ATCC 15521 and allowed to undergo a storage period of 28 days at 4°C. These rice wines were compared with a commercial wine used as a standard reference wine. A panel consisting of 30 judges performed the sensory evaluation. The scores obtained were based on the quality attributes of colour, taste, aroma and alcoholic strength. Analysis of the sensory scores and ranking of the different samples were performed using fuzzy analysis. The quality attributes were also ranked according to their importance in the overall acceptability. Colour and alcoholic strength were accorded the highest importance, compared with aroma and taste, as quality attributes. The rice wines were rated as ‘not satisfactory’, ‘fair’, ‘medium’, ‘good’ and ‘excellent’ on the sensory scale. Out of the wines prepared, black pigmented rice wine fortified with L. acidophilus was the most acceptable and was ranked as ‘good’, which was also at par with the commercial wine. On the other hand, black pigmented rice wine fortified with L. sakei and black pigmented rice wine fortified with L. acidophilus and L. sakei were ranked in the ‘satisfactory’ category followed by the unfortified wine ranked in the ‘fair’ category. Copyright © 2015 The Institute of Brewing & Distilling     

Room temperature ferromagnetism in Mn-doped zinc oxide nanorods prepared by hybrid wet chemical route

Mn-doped (2.6-4.8 at%) aligned zinc oxide (Mn:ZnO) nanorod-films were synthesized by hybrid wet chemical route onto glass substrates. The chemical composition, structural, microstructural and magnetic studies were performed to investigate the origin of observed room temperature ferromagnetism (∼0.11 μ_B/Mn) in these Mn doped ZnO nanorod-films. XPS studies indicated that incorporated Mn was in Mn²⁺ and Mn⁴⁺ states. Mn²⁺ atomic concentration was found to be significantly larger than Mn⁴⁺ concentration in all the samples. Disappearance of the Raman peak at ∼577 cm⁻¹ arising due to the Zn interstitials may be related to the substitution of Mn²⁺ in the Zn²⁺ site with annealing. Thus, Mn metal inclusions as Mn²⁺ in the ZnO lattice are possibly responsible for such large magnetic moment in the films.     

Electrical,rheological and morphological studies in co-continuous blends of polyamide 6 and acrylonitrile–butadiene–styrene with multiwall carbon nanotubes prepared by melt blending

Multiwall carbon nanotubes (MWNT) were incorporated in melt-mixed co-continuous blends of polyamide 6 (PA6) and acrylonitrile–butadiene–styrene (ABS) using a conical twin-screw microcompounder. The state of dispersion of MWNT in the blends was assessed through AC electrical conductivity measurements and melt-rheological investigations. The electrical and rheological percolation threshold in PA6/ABS blends was ～3–4 and ～1–2 wt% MWNT, respectively. A unique reactive modifier (sodium salt of 6-amino hexanoic acid, Na–AHA) was employed to facilitate ‘network-like’ structure of MWNT and to confine them in a specific phase. This was achieved by establishing specific interactions with the delocalized ‘π-electron’ clouds of MWNT and melt-interfacial reaction during melt-mixing. The electrical percolation threshold was significantly reduced in the blends (～0.25 wt%) in the presence of Na–AHA modified MWNT and even coincided with the rheological percolation threshold. Significant refinement in the co-continuous structure was also observed in the presence of Na–AHA modified MWNT.     

Flue Gas Carbon Dioxide Sequestration during Water Softening with Ion-Exchange Fibers

This study examines the use of ion-exchange fibers (IX fibers) to permanently sequester carbon dioxide present in flue gas into an aqueous phase as calcium or magnesium alkalinity while concurrently softening hard water. The only process inputs besides carbon dioxide (or flue gas) are snowmelt (or rainwater); no other chemicals are required for the regeneration of the IX fibers. Importantly, the process is not energy intensive and carbon dioxide does not need to be compressed to excessive pressures (>150?psi) for efficient use. Sources of carbon dioxide do not require concentration and, therefore, the use of raw flue gas ( ～ 17% CO2) is feasible with the rate of sequestration governed only by the partial pressure of carbon dioxide. While valid for flue gas obtained from any combustion process (e.g., coal, oil, natural gas, etc.), emissions from oil or gas combustion may be more appropriate for use in the described process due to the absence of mercury and particulates. It should also be noted that the presence of sulfur dioxide in flue gas would not adversely affect the process and may even enhance regeneration efficiency. The only product of the proposed process is an environmentally benign regenerant stream containing calcium and/or magnesium alkalinity. The unique property of IX fibers that makes the proposed process both environmentally sustainable and economically feasible is amenability to efficient regeneration with carbon dioxide and harvested snowmelt. Low intraparticle diffusional resistance is the underlying reason why IX fibers are amenable to efficient regeneration using snowmelt sparged with carbon dioxide; 95% calcium recovery was attained at a CO2 partial pressure of 6.8?atm. On the contrary, commercial weak-acid ion-exchange resins in spherical bead forms are ineffective for regeneration with carbon-dioxide-sparged snowmelt due to extremely slow ion-exchange kinetics involving counter-transport of Ca2+ (or Mg2+) and H+. The energy balance for a typical electric utility shows that up to 1% of carbon dioxide emitted during combustion would be sequestered in the softening process.     

Arsenic groundwater contamination and its health effects in the state of Uttar Pradesh (UP) in upper and middle Ganga plain, India: a severe danger

This communication presents results of our 2-year survey on groundwater arsenic contamination in three districts Ballia, Varanasi and Gazipur of Uttar Pradesh (UP) in the upper and middle Ganga plain, India. Analyses of 4,780 tubewell water samples revealed that arsenic concentrations in 46.5% exceeded 10 microg/L, in 26.7%, 50 microg/L and in 10% 300 microg/L limits. Arsenic concentrations up to 3,192 microg//L were observed. The age of tubewells (n=1,881) ranged from less than a year to 32 years, with an average of 6.5 years. Our study shows that older tubewells had a greater chance of contamination. Depth of tubewells (n=3,810) varied from 6 to 60.5 m with a mean of 25.75 m. A detailed study in three administrative units within Ballia district, i.e. block, Gram Panchayet, and village was carried out to assess the magnitude of the contamination. Before our survey the affected villagers were not aware that they were suffering from arsenical toxicity through contaminated drinking water. A preliminary clinical examination in 11 affected villages (10 from Ballia and 1 from Gazipur district) revealed typical arsenical skin lesions ranging from melanosis, keratosis to Bowens (suspected). Out of 989 villagers (691 adults, and 298 children) screened, 137 (19.8%) of the adults and 17 (5.7%) of the children were diagnosed to have typical arsenical skin lesions. Arsenical neuropathy and adverse obstetric outcome were also observed, indicating severity of exposure. The range of arsenic concentrations in hair, nail and urine was 137-10,900, 764-19,700 microg/kg, and 23-4,030 microg/L, respectively. The urine, hair and nail concentrations of arsenic correlated significantly (r=0.76, 0.61, and 0.55, respectively) with drinking water arsenic concentrations. The similarity to previous studies on arsenic contamination in West Bengal, Bihar and Bangladesh indicates that people from a significant part of the surveyed areas in UP are suffering and this will spread unless drives to raise awareness of arsenic toxicity are undertaken and an arsenic safe water supply is immediately introduced.