Correlation between caffeine contents of green coffee beans and altitudes of the coffee plants grown in southwest Ethiopia

Caffeine contents of 45 green coffee bean samples collected from coffee plants grown at different altitudes in Southwest Ethiopia was determined by UV-Vis spectrophotometry. The caffeine contents were found in the range of 0.62 - 1.2% (w/w). A moderate negative correlation (R = 0.5463) was found between the caffeine contents of green coffee beans and the altitudes at which the coffee plants were grown. The caffeine contents of 9 of the green coffee bean samples analyzed by high performance liquid chromatography (HPLC) provided comparable results in the range of 0.60−1.1% (w/w). Statistical analysis of data (t-test) indicated absence of significant differences between the caffeine contents obtained by the two methods. Nonetheless, HPLC method is precise, accurate and reliable in determining caffeine content in green coffee bean samples while the UV-Vis spectrophotometry is simple, rapid, precise and more economical. KEY WORDS: Green coffee beans, Caffeine, Correlation between caffeine content and altitude of coffee plant, UV-Vis spectrophotometry, High performance liquid chromatography, Ethiopia Bull. Chem. Soc. Ethiop. 2018, 32(1), 13-25DOI: https://dx.doi.org/10.4314/bcse.v32i1.

Spin and a Running Radius in RS1

We develop a renormalization group formalism for the compactified Randall-Sundrum scenario wherein the extra-dimensional radius serves as the scaling parameter. Couplings on the hidden brane scale as we move within local effective field theories with varying size of the warped extra dimension. We consider this RG approach applied to U(1) gauge theories and gravity. We use this method to derive a low energy effective theory.Comment: 18 pages, minor changes, references adde

Gaugino mass in AdS space

We study supersymmetric QED in AdS4 with massless matter. At 1-loop the ultra-violet regulator of the theory generates a contribution to the gaugino mass that is naively inconsistent with unbroken supersymmetry. We show that this effect, known in flat space as anomaly mediated supersymmetry breaking, is required to cancel an infra-red contribution arising from the boundary conditions in AdS space, which necessarily break chiral symmetry. We also discuss an analogous UV/IR cancellation that is independent of supersymmetry.Comment: 20 pages, 1 figur

Volatile profile of green coffee beans from Coffea arabica L. plants grown at different altitudes in Ethiopia

ABSTRACT. This study was aimed to identify volatile compounds of 31 green coffee bean samples and evalute their correlation with altitude of the coffee plants grown in two zones (Gedeo and Jimma) in Ethiopia. A total of 81 different compounds were detected. The contents of dominant volatile compounds in green coffee beans were in the range: trans-linalooloxide (3.24⎯19.13%), linalool (1.56⎯21.76%), 2-methoxy-4-vinylphenol (2.34⎯15.08%) and cis-linalooloxide (1.03⎯13.27%). In addition, benzene acetaldehyde (0.45⎯10.97%), 2-heptanol (0.67⎯8.49%), ⍺-terpineol (0.64⎯6.52%), phenylethyl alcohol (0.44⎯4.98%) and furfural (0.92⎯5.3%) were the next dominant compounds. The volatile compounds identified in the green coffee beans are groups of alcohols, aldehydes, ketones, pyrazines, pyridines, and furans. The volatile compounds in green coffee beans showed either weak positive or weak negative correlation with the altitude of coffee plants indicating that variation in altitude of the coffee plants does not significantly influence the volative compounds of green coffee beans.               KEY WORDS: Coffea arabica L., Coffee plants, Green coffee beans, Volatile compounds, Effect of altitudes, Heterocyclic compounds Bull. Chem. Soc. Ethiop. 2019, 33(3), 401-413.   DOI: https://dx.doi.org/10.4314/bcse.v33i3.

Axion-Higgs Unification

In theories with no fundamental scalars, one gauge group can become strong at a large scale Lambda and spontaneously break a global symmetry, producing the Higgs and the axion as composite pseudo-Nambu-Goldstone bosons. We show how KSVZ and DFSZ axion models can be naturally realised. The assumption Lambda around 10^{11} GeV is phenomenologically favoured because: a) The axion solves the QCD theta problem and provides the observed DM abundance; b) The observed Higgs mass is generated via RGE effects from a small Higgs quartic coupling at the compositeness scale, provided that the Higgs mass term is fine-tuned to be of electroweak size; c) Lepton, quark as well as neutrino masses can be obtained from four-fermion operators at the compositeness scale. d) The extra fermions can unify the gauge couplings.Comment: 19 pages. Refs. added and eq. 3.6 fixe

TF ripple loss of alpha particles in TFTR DT experiments

Quantitative evaluation of TF ripple loss of DT alpha particles is a central issue for reactor design because of potentially severe first wall heat load problems. DT experiments on TFTR allow experimental measurements to be compared to modeling of the underlying alpha physics, with code validation an important goal. Modeling of TF ripple loss of alphas in TFTR now includes neoclassical calculations of alpha losses arising from first orbit loss, stochastic ripple diffusion, ripple trapping and collisional effects. Recent Hamiltonian coordinate guiding center code (ORBIT) simulations for TFTR have shown that collisions enhance the stochastic TF ripple losses at TFTR. A faster way to simulate experiment has been developed and is discussed here which uses a simple stochastic domain model for TF ripple loss within the TRANSP analysis code

Calculations of alpha particle loss for reversed magnetic shear in the Tokamak Fusion Test Reactor

Hamiltonian coordinate, guiding center code calculations of the toroidal field ripple loss of alpha particles from a reversed shear plasma predict both total alpha losses and ripple diffusion losses to be greater than those from a comparable non-reversed magnetic shear plasma in the Tokamak Fusion Test Reactor (TFTR) [Fusion Technol. 21, 1324 (1992)]. High central q is found to increase alpha ripple losses as well as first orbit losses of alphas in the reversed shear simulations. A simple ripple loss model, benchmarked against the guiding center code, is found to work satisfactorily in transport analysis modelling of reversed and monotonic shear scenarios. Alpha ripple transport on TFTR affects ions within r/a=0.5, not at the plasma edge. The entire plasma is above threshold for stochastic ripple loss of alpha particles at birth energy in the reversed shear case simulated, so that all trapped 3.5 MeV alphas are lost stochastically or through prompt losses. The 40% alpha particle loss predictions for TFTR suggest that reduction of toroidal field ripple will be a critical issue in the design of a reversed shear fusion reactor

Neoclassical Simulations of Fusion Alpha Particles in Pellet Charge Exchange Experiments on the Tokamak Fusion Test Reactor

Neoclassical simulations of alpha particle density profiles in high fusion power plasmas on the Tokamak Fusion Test Reactor (TFTR) [Phys. Plasmas 5 (1998) 1577] are found to be in good agreement with measurements of the alpha distribution function made with a sensitive active neutral particle diagnostic. The calculations are carried out in Hamiltonian magnetic coordinates with a fast, particle-following Monte Carlo code which includes the neoclassical transport processes, a recent first-principles model for stochastic ripple loss and collisional effects. New global loss and confinement domain calculations allow an estimate of the actual alpha particle densities measured with the pellet charge exchange diagnostic

Anderson localization of ballooning modes, quantum chaos and the stability of compact quasiaxially symmetric stellarators

The radially local magnetohydrodynamic(MHD) ballooning stability of a compact, quasiaxially symmetric stellarator (QAS), is examined just above the ballooning beta limit with a method that can lead to estimates of global stability. Here MHDstability is analyzed through the calculation and examination of the ballooning modeeigenvalue isosurfaces in the 3-space (s,α,θk); s is the edge normalized toroidal flux, α is the field linevariable, and θk is the perpendicular wave vector or ballooning parameter. Broken symmetry, i.e., deviations from axisymmetry, in the stellarator magnetic field geometry causes localization of the ballooning mode eigenfunction, and gives rise to new types of nonsymmetric eigenvalue isosurfaces in both the stable and unstable spectrum. For eigenvalues far above the marginal point, isosurfaces are topologically spherical, indicative of strong “quantum chaos.” The complexity of QAS marginal isosurfaces suggests that finite Larmor radius stabilization estimates will be difficult and that fully three-dimensional, high-nMHD computations are required to predict the beta limit.Research supported by U.S. DOE Contract No. DEAC02-76CH0373. John Canik held a U.S. DOE National Undergraduate Fellowship at Princeton Plasma Physics Laboratory, during the summer of 2000