Oxidation of ɑ-Haloketones: Part I – V(V) Oxidation of Phenacyl Bromide & p-Nitrophenacyl Bromide

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Efficacy of different oils used for the extraction of annatto colour from the seeds of Bixa orellana L.

Annatto, a naturally obtained colour is a potential and valuable Non Wood Forest Product (NWFP). It is obtained from the seeds of plant species Bixa orellana L. The present experiment was carried out to find the efficacy of different oils used for annatto colour extraction. Experiment was started with the pretreatment of seeds of B. orellana with soaking in water at 0%, 50%, 100% and 150% (v/w) for 24 hrs at room temperature and colour extraction with castor oil at 100°C showed that maximum bixin (%) was found from the pretreated seeds with 50% (v/w) water soaking i.e., 0.46% bixin. Similarly for oil soluble annatto extraction method, the maximum extraction of bixin (0.99 %) was found with castor oil at 120°C for 1 hr and least bixin (0.03 %) was recorded with mustard oil at 60oC temperature for 1 hr. Sesame oil and ground nut oil were also showed better extractability. Out of different treatments, castor oil at 120°C for 1 hr gave better result with respect to bixin extraction as compared to others

Ergonomics of Farm Women in Manual Paddy Threshing

Thin-layer drying experiments with Roselle (Hibiscus sabdariffa .L) were carried out in a constant temperature and humidity chamber. Four temperatures (35, 45, 55, and 65°C) and five relative humidities (30, 35, 40, 45, and 50%RH) were tested. Statistical analysis on twelve thinlayer drying model proved the superiority of two-term exponential model. The objectives of this work were to evaluate and validate the two-term exponential model; besides, examine the effects of the drying conditions on the drying rate and constant. Validation of the developed model was done using two criterions, plotting of the predicted against experimental moisture contents and the residual versus predicted moisture content. The average values of the drying constant (k) and coefficient (a) weA study was taken up to have a comparative study on the ergonomics of farm women in pedal threshing with single and double operators (N =15) and to suggest modifications for further reduction of human drudgery. The mean HR work was found to be 135.9 ± 1.3 and 121.2 ±1.0 beats/min respectively with single and double operators; a significant (P < 0.01) reduction of 10.82 %. The corresponding work pulse (Δ HR) was 65.7 ± 0.9 and 51.5 ± 1.6 beats/min. The Δ HR was more than the allowable limit of 40 beats/min. HR work steadied after 6 minutes of threshing and there was complete recovery of HR after 6 minutes with double operators and 8 minutes with single operator. The increase in HR/kg of grain threshed was found to be 146.4 ± 4.4 and 76.0 ± 4.1 in case of single and double operators respectively; a significant reduction of 48 %. The workload decreased by 13.5 % with double operators but was still higher than the allowable limit of 35 % of VO2 max. The energy expenditure rate (ERR) was 18.9 ± 0.4 kJ/min with single operator and reduced to 16.6 ± 0.3 kJ/min with double operators. The total cardiac cost of work (TCCW) and physiological cost of work (PCW) reduced by 19.84 and 20 % with double operators. No significant variation of blood lactate accumulation between single and double operators was observed. The pedal force required was 232.3 ± 7.0 N and 199.7 ± 5.8 N in case of single operator and double operators respectively but was higher than the mean leg strength of the women of the eastern region of India. Higher pedal force application with double operators increased the number strokes/min (96/min) leading to a 51.15 % increase in output capacity of the thresher per hour per person. An increase of length of the pedal by 2 cm was suggested to reduce the force requirement. The length of the threshing drum can be reduced from 60.5 cm to 40 cm to be used by single operator or it can be increased to 75 cm to comfortably accommodate two persons.e 0.009167 and 0.776132, respectively

Discovery of the VHE gamma-ray source HESS J1641-463

A new TeV source, HESS J1641-463, has been serendipitously discovered in the Galactic plane by the High Energy Stereoscopic System (H.E.S.S.) at a significance level of 8.6 standard deviations. The observations of HESS J1641-463 were performed between 2004 and 2011 and the source has a moderate flux level of 1.7% of the Crab Nebula flux at E > 1 TeV. HESS J1641-463 has a rather hard photon index of 1.99 +- 0.13_stat +- 0.20_sys. HESS J1641-463 is positionally coincident with the radio supernova remnant SNR G338.5+0.1, but no clear X-ray counterpart has been found in archival Chandra observations of the region. Different possible VHE production scenarios will be discussed in this contribution.Comment: 5 pages, 5 figures, 2012 Fermi Symposium proceedings - eConf C12102

Characterization of shape and dimensional accuracy of incrementally formed titanium sheet parts with intermediate curvatures between two feature types

Single point incremental forming (SPIF) is a relatively new manufacturing process that has been recently used to form medical grade titanium sheets for implant devices. However, one limitation of the SPIF process may be characterized by dimensional inaccuracies of the final part as compared with the original designed part model. Elimination of these inaccuracies is critical to forming medical implants to meet required tolerances. Prior work on accuracy characterization has shown that feature behavior is important in predicting accuracy. In this study, a set of basic geometric shapes consisting of ruled and freeform features were formed using SPIF to characterize the dimensional inaccuracies of grade 1 titanium sheet parts. Response surface functions using multivariate adaptive regression splines (MARS) are then generated to model the deviations at individual vertices of the STL model of the part as a function of geometric shape parameters such as curvature, depth, distance to feature borders, wall angle, etc. The generated response functions are further used to predict dimensional deviations in a specific clinical implant case where the curvatures in the part lie between that of ruled features and freeform features. It is shown that a mixed-MARS response surface model using a weighted average of the ruled and freeform surface models can be used for such a case to improve the mean prediction accuracy within ±0.5 mm. The predicted deviations show a reasonable match with the actual formed shape for the implant case and are used to generate optimized tool paths for minimized shape and dimensional inaccuracy. Further, an implant part is then made using the accuracy characterization functions for improved accuracy. The results show an improvement in shape and dimensional accuracy of incrementally formed titanium medical implants

Fragmentation of a Circular Disc by Impact on a Frictionless Plate

The break-up of a two-dimensional circular disc by normal and oblique impact on a hard frictionless plate is investigated by molecular dynamics simulations. The disc is composed of numerous unbreakable randomly shaped convex polygons connected together by simple elastic beams that break when bent or stretched beyond a certain limit. It is found that for both normal and oblique impacts the crack patterns are the same and depend solely on the normal component of the impact velocity. Analysing the pattern of breakage, amount of damage, fragment masses and velocities, we show the existence of a critical velocity which separates two regimes of the impact process: below the critical point only a damage cone is formed at the impact site (damage), cleaving of the particle occurs at the critical point, while above the critical velocity the disc breaks into several pieces (fragmentation). In the limit of very high impact velocities the disc suffers complete disintegration (shattering) into many small fragments. In agreement with experimental results, fragment masses are found to follow the Gates-Gaudin-Schuhmann distribution (power law) with an exponent independent of the velocity and angle of impact. The velocity distribution of fragments exhibit an interesting anomalous scaling behavior when changing the impact velocity and the size of the disc.Comment: submitted to J. Phys: Condensed Matter special issue on Granular Medi

Ultrasonic velocity and allied acoustical parameters of 2, 4-dinitrophenyl hydrazine based Schiff base in DMSO

1108-1112Novel 2, 4-dinitrophenyl hydrazine based Schiff bases (L1-L3) has been successfully synthesized and characterized. The ultrasonic velocity (C) and density (ρ) has been measured for the synthesized Schiff bases with DMSO (Dimethyl sulfoxide) solvents at 300 K. Using these experimental data ultrasonic Velocity, adiabatic compressibility, intermolecular free length and specific acoustic impedance have been evaluated. From the experimental data, it has been found that L1 ascribed higher ultrasonic velocity as compared to other molecular probes L2 and L3. The strength and nature of interaction between the molecular probes and DMSO solvents has been discussed. Scanning electron microscope studies of molecular probes are performed to discuss the microstructure and surface functionalities

Evidence for weak antilocalization-weak localization crossover and metal-insulator transition in CaCu3_{3}Ru4_{4}O12_{12} thin films

Artificial confinement of electrons by tailoring the layer thickness has turned out to be a powerful tool to harness control over competing phases in nano-layers of complex oxides. We investigate the effect of dimensionality on transport properties of $d$-electron based heavy-fermion metal CaCu$_{3}$Ru$_{4}$O$_{12}$. Transport behavior evolves from metallic to localized regime upon reducing thickness and a metal insulator transition is observed below 3 nm film thickness for which sheet resistance crosses $h/e^{2} \sim 25~$k$\Omega$, the quantum resistance in 2D. Magnetotransport study reveals a strong interplay between inelastic and spin-orbit scattering lengths upon reducing thickness, which results in weak antilocalization (WAL) to weak localization (WL) crossover in magnetoconductance.Comment: 10 pages, 4 figure