Quick Semi-quantitative Test for Lead in Processed Foods

A simple, quick semi-quantitative test for the determination of lead metal in canned fruits,vegetables other than dehydrated onion, fish, and meat products, has been developed using theoptimised concentration of dithizone reagent under alkaline pH as the test solution, which onreaction with the sample solution gives green to blue to violet to red colour, depending on thelead concentration in the sample.  The quick test results were compared with atomic absorptionspectrophotometric analysis. A total of 80 samples were analysed and it was found that the leadcontent ranged from 0.001 ppm to 10.35 ppm in all the samples

Physico-chemical study of groundwater in the Northeast of Kara region (Togo)

Groundwater is a major source of drinking water for people in the Kara region. This study aims at improving the knowledge of groundwater and to determine the processes responsible for groundwater mineralization in this region using hydro-chemical methods and multivariate statistical analysis. 47 water samples taken from the wells in the crystalline basement aquifer were analyzed. Chemical analyses were made on these samples according AFNOR methods to determine hydro-chemical characteristics. The hydro-chemical study showed that the waters in the region have an average temperature of 28.7 °C. They are acid to slightly basic, with a pH ranging between 5.7 and 7.87, but for the most part neutral. The waters are weakly to moderately mineralized, which confirms the well-known chemical characteristic of basement groundwater. However, high conductivity values were found in the waters in some localities. The highest value was measured at Broukou (1083 μS.cm-1). Groundwaters in this region belong to a variety of hydro-chemical facies in relation to the type of geological reservoir. Four hydro-chemical facies were identified. The most dominant is the calcic and magnesian bicarbonated facies (85%) followed by the sodic-potassic bicarbonated facies (8.5%). The sodic-potassic chlorinated facies (2.1%), calcic and chloride (2.1%) and calcic-magnesian sulfated facies are poorly represented in these waters. Major ions which are the cause of the waters mineralization come from rock weathering, hydrolysis of silicated minerals such as anorthite in plagioclase and the decomposition of ferromagnesian minerals such as biotite and amphibole. The contribution of soil leaching and pollution due to anthropic activities is not negligible.Keywords: Groundwater, Kara region, hydrochemistry, weathering, hydrolysis, basement complex

Pulsed electric field and combination processing of mango nectar: effect on volatile compounds and HMF formation

Mango nectar is a commercially familiar and preferred product. The traditional processing of mango nectar has been by thermal processing which resulted in the alteration of the flavour of the product due to the effect of high temperature. The thermal processing of the nectar also resulted in the production of byproducts of non-enzymatic browning such as 5- hydroxy methyl furfural (HMF). These process induced effects, affect both the nutritive and sensory attributes of the fruit product, making it less preferable. With the growing interest and awareness about the benefits of alternative non-thermal technologies, such as pulsed electric field (PEF), the present work was proposed to use PEF to minimize the loss of volatiles and formation of HMF. The study involves thermal (96 ºC for 300 s and 600 s), PEF (24 µs, 120 Hz and 38 kV/cm) and combination processing (PEF + Thermal (96 ºC for 90 s)) of mango nectar. The effect of these treatments on the volatile composition of mango nectar has been analysed using GC-MS technique. The reduction in the volatile compounds was significant (p 0.05) different from unprocessed sample, proving the fresh-like character of the product

Loop effects and non-decoupling property of SUSY QCD in gb→tH−g b\to tH^{-}

One-loop SUSY QCD radiative correction to $gb \to tH^{-}$ cross section is calculated in the Minimal Supersymmetric Standard Model. We found that SUSY QCD is non-decoupling if the gluino mass and the parameter $\mu$, $A_t$ or $A_b$ are at the same order and get large. The non-decoupling contribution can be enhanced by large $\tan\beta$ and therefore large corrections to the hadronic production rates at the Tevatron and LHC are expected in the large $\tan\beta$ limit. The fundamental reason for such non-decoupling behavior is found to be some couplings in the loops being proportional to SUSY mass parameters.Comment: 15 pages, 5 PS figures. A proof of non-decouplings of SUSY-QCD, Comments on corresponding QCD correction and references adde

Virtual Photon Strucutre Functions and the Parton Content of the Electron

We point out that in processes involving the parton content of the photon the usual effective photon approximation should be modified. The reason is that the parton content of virtual photons is logarithmically suppressed compared to real photons. We describe this suppression using several simple, physically motivated ans\"atze. Although the parton content of the electron in general no longer factorizes into an electron flux function and a photon structure function, it can still be expressed as a single integral. Numerical examples are given for the \eplem\ collider TRISTAN as well as the $ep$ collider HERA.Comment: 16 pages and 3 figures (available from DREES@WSICPHEN as topdraw or PS files); LaTeX with equation.sty; MAD/PH/819, BU 94-0

SUSY-QCD decoupling properties in H+ -> t \bar b decay

The SUSY-QCD radiative corrections to the \Gamma (H+ -> t \bar b) partial decay width are analyzed within the Minimal Supersymmetric Standard Model at the one-loop level, {\mathcal O}(\alpha_s), and in the decoupling limit. We present the analytical expressions of these corrections in the large SUSY masses limit and study the decoupling behaviour of these corrections in various limiting cases. We find that if the SUSY mass parameters are large and of the same order, the one loop SUSY-QCD corrections {\it do not decouple}. The non-decoupling contribution is enhanced by \tan \beta and therefore large corrections are expected in the large \tan \beta limit. In contrast, we also find that the SUSY-QCD corrections decouple if the masses of either the squarks or the gluinos are separately taken large.Comment: LaTeX, 33 pages, 7 figure included. Uses cite.st

Resolved Photon Processes

We review the present level of knowledge of the hadronic structure of the photon, as revealed in interactions involving quarks and gluons ``in" the photon. The concept of photon structure functions is introduced in the description of deep--inelastic $e \gamma$ scattering, and existing parametrizations of the parton densities in the photon are reviewed. We then turn to hard \gamp\ and \gaga\ collisions, where we treat the production of jets, heavy quarks, hard (direct) photons, \jpsi\ mesons, and lepton pairs. We also comment on issues that go beyond perturbation theory, including recent attempts at a comprehensive description of both hard and soft \gamp\ and \gaga\ interactions. We conclude with a list of open problems.Comment: LaTeX with equation.sty, 85 pages, 29 figures (not included). A complete PS file of the paper, including figures, can be obtained via anonymous ftp from ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-898.ps.

Effect of pulsed electric field and pasteurisation treatments on the rheological properties of mango nectar (Mangifera indica)

The rheological behaviour of pulsed electric field (PEF) processed and thermally pasteurised mango nectar (Mangifera indica) was evaluated using controlled stress rheometer. The mango nectar was subjected to pulsed electric field (PEF) as well as thermal processing. The rheological parameter shear stress was measured up to the shear rate of 750 s-1 using co-axial cylinder attachment at wide range of temperatures from 10 to 70 °C. The investigation showed that pulsed electric field (PEF) processed and thermally pasteurised mango nectar behaved like a pseudo plastic (shear thinning) fluid and obeyed Herschel-Bulkley model (0.9780 0.893, p < 0.05) and flow activation energy (Ea) was significantly (p < 0.05) affected by processing conditions. The results indicated that the pulsed electric field (PEF) and thermal processing condition has affected the rheological properties of mango nectar. The combined equation relating to shear stress (τ) with temperature and shear rate of mango nectar was established

Higgs-Boson Production Induced by Bottom Quarks

Bottom quark-induced processes are responsible for a large fraction of the LHC discovery potential, in particular for supersymmetric Higgs bosons. Recently, the discrepancy between exclusive and inclusive Higgs boson production rates has been linked to the choice of an appropriate bottom factorization scale. We investigate the process kinematics at hadron colliders and show that it leads to a considerable decrease in the bottom factorization scale. This effect is the missing piece needed to understand the corresponding higher order results. Our results hold generally for charged and for neutral Higgs boson production at the LHC as well as at the Tevatron. The situation is different for single top quark production, where we find no sizeable suppression of the factorization scale. Turning the argument around, we can specify how large the collinear logarithms are, which can be resummed using the bottom parton picture.Comment: 18 page

Charged Higgs Boson Production in Bottom-Gluon Fusion

We compute the complete next-to-leading order SUSY-QCD corrections for the associated production of a charged Higgs boson with a top quark via bottom-gluon fusion. We investigate the applicability of the bottom parton description in detail. The higher order corrections can be split into real and virtual corrections for a general two Higgs doublet model and into additional massive supersymmetric loop contributions. We find that the perturbative behavior is well under control. The supersymmetric contributions consist of the universal bottom Yukawa coupling corrections and non-factorizable diagrams. Over most of the relevant supersymmetric parameter space the Yukawa coupling corrections are sizeable, while the remaining supersymmetric loop contributions are negligible.Comment: 18 pages, v2: some discussions added, v3: published versio