2,920 research outputs found
Compaction of a granular material under cyclic shear
In this paper we present experimental results concerning the compaction of a
granular assembly of spheres under periodic shear deformation. The dynamic of
the system is slow and continuous when the amplitude of the shear is constant,
but exhibits rapid evolution of the volume fraction when a sudden change in
shear amplitude is imposed. This rapid response is shown to be to be
uncorrelated with the slow compaction process.Comment: 7 pages, 9 figures, accepted for publication in European Physical
Journal
Casimir Energy for a Wedge with Three Surfaces and for a Pyramidal Cavity
Casimir energy calculations for the conformally coupled massless scalar field
for a wedge defined by three intersecting planes and for a pyramid with four
triangular surfaces are presented. The group generated by reflections are
employed in the formulation of the required Green functions and the wave
functions.Comment: Latex, 9 page
Management of Patients with Atrial Fibrillation: Specific Considerations for the Old Age
Atrial fibrillation (AF) is the commonest of all sustained arrhythmias, and most of the patients seeking medical therapy are in the elderly age group. The management of these patients is particularly difficult due to associated comorbidities. Hypertension, congestive heart failure, left ventricular hypertrophy, and coronary artery disease are often present in the elderly patient population, and therefore, antiarrhythmic drugs often fail due to side effects, proarrhythmia, or poor rhythm control. Recently, radiofrequency catheter ablation has been widely performed as an efficient therapy for recurrent, drug-refractory AF. Nevertheless, patients at old age were underrepresented in prior AF ablation trials, and the current guidelines for catheter ablation of AF recommend a noninvasive approach in the elderly patient group due to the lack of clinical data supporting ablation therapy. However, study results of our group and others are suggesting that catheter ablation is a safe and effective treatment for patients over the age of 65 years with symptomatic, drug-refractory AF, and therefore, patients should not be precluded from catheter ablation only on the basis of age. This paper discusses the pharmacological (rhythm control, rate control, and anticoagulation) and catheter management of AF in the elderly population
EFFICACY OF XYLOPIA AETHIOPICA (DUNAL) A. AND AFRAMOMUM MELEGUETA (ROSC) K. SCHUM. FRUIT ON SITOPHULIUS ZEA
The power of combined powder of dried fruits of Xylopia aethiopica(Dunal) A. and Aframomum melegueta on the control of maize weevil Sitophulus zea were evaluated. The aim was to determine, their antifeedant potentials against the insect pests of stored maize. Oven dried fruits of X. aethiopica and A. melegueta was pulverized and mixed in equal proportion. Concentrations of 1,2,3,4,5,6,7,8,9,and10g were mixed with 100g of healthy grain, and incubated for 14 days with 20 weevils in each. Each treatment plus the control (0.0g) were replicated five times and laid out randomly. Results showed that mortality and % mortality of weevils increased progressively with the powder concentrations and the exposure period. Within the 14 days of exposure, mortality and % mortality were 4, 20% in the control and all, 100% in the test treatments. Reduction in seed damage increased significantly with the powder concentration (P<0.05). Weevil perforation index (WPI) showed that the combined powder had high protectant activity and therefore could serve as an alternative to the conventional chemical insect pesticides. Key Words: Xylopia aethiopica, Aframomum melegueta, Sitophulus zea, combined powder
Path integral for a relativistic Aharonov-Bohm-Coulomb system
The path integral for the relativistic spinless Aharonov-Bohm-Coulomb system
is solved, and the energy spectra are extracted from the resulting amplitude.Comment: 6 pages, Revte
Realizations for Kepler and Oscillator Potentials and q-Canonical Transformations
The realizations of the Lie algebra corresponding to the dynamical symmetry
group SO(2,1) of the Kepler and oscillator potentials are q-deformed. The
q-canonical transformation connecting two realizations is given and a general
definition for q-canonical transformation is deduced. q-Schr\"{o}dinger
equation for a Kepler like potential is obtained from the q-oscillator
Schr\"{o}dinger equation. Energy spectrum and the ground state wave function
are calculated.Comment: 12 pages, Latex twice, (Comparison with the other approaches and some
refs. added. The version which will appear in J. Phys. A
Quantum particle displacement by a moving localized potential trap
We describe the dynamics of a bound state of an attractive -well
under displacement of the potential. Exact analytical results are presented for
the suddenly moved potential. Since this is a quantum system, only a fraction
of the initially confined wavefunction remains confined to the moving
potential. However, it is shown that besides the probability to remain confined
to the moving barrier and the probability to remain in the initial position,
there is also a certain probability for the particle to move at double speed. A
quasi-classical interpretation for this effect is suggested. The temporal and
spectral dynamics of each one of the scenarios is investigated.Comment: 5 pages, 6 figure
Microbial quality of meat floss ‘dambun nama’ processed from broiler chickens fed graded levels of ‘sabara’(Guiera senegalensis) leaf meal
This study evaluated the microbial quality of meat floss processed from broiler chickens fed graded levels of Guiera senegalensis leaf meal (GSL) at 0.0% (GSL1), 7.0% (GSL2), 14.0% (GSL3) and 21.0% (GSL4). These were packaged and stored into four (4) different packaging media; Foil Paper Pack (FPP), Wrapped Newspaper Pack (WNP), Plastic Container Pack (PCP) and Disposable Container Pack (DCP). These products were stored and monitored for contaminations at 0, 4, 8 and 12 week intervals. Means were analysed and compared with passable and safe limits of 107cfu/g. The results showed that at 1st day of storage, there were no fungal counts in GSL3 and GSL4 was having the least count of 2.0 x 105. The control (GSL1) had the highest total bacterial count of 24.0 x 105cfu/g. At 12th week of storage, the results showed that the total fungal counts were 0.00, 0.00, 0.00, and 2.0 x 105cfu/g for GSL2, GSL3, GSL4 and GSL1, respectively. The overall effects showed that the total microbial load of meat floss decreased as the concentrations were increased. The results showed that GSL2 (2.0 x 105cfu/g) and GSL3 (3.0 x 105cfu/g) had lower total bacterial counts than GSL1 (24.0 x 105cfu/g) and GSL4 (8.0 x 105cfu/g) across the packaging media at first week (0 week) of storage. WNP had the least bacterial counts (1.0 x 105cfu/g). Conversely, DCP had the highest counts (21.0 x 105cfu/g) across the treatment groups and packaging media. At higher week of storage (12th week), GSL2 (15.0 x 105cfu/g) and GSL3 (18.0 x 105cfu/g) were lower than GSL1 (20.0 x 105cfu/g) and GSL4 (26.0 x 105cfu/g) for bacterial counts. WNP (10.0 x 105cfu/g) had the least counts across the treatments. Storage at higher weeks (8th and 12th) reduced fungal growth in most of the packaging media. This study concludes that the packaging method had suppressive effects against microbial growth. It is suggested that meat floss processed from broiler chickens fed graded levels of GSL should be evaluated for storage above the 12-week period
Electrolyte disorders in a young female following short-term omeprazole therapy
A 29 years old female presented to us in the metabolic clinic of the University of Port Harcourt Teaching Hospital (UPTH) on account of a week history of easy fatigability, weakness, and lower extremity muscle cramps associated with numbness and tingling sensation in the peri-oral area, fingers and toes. Two weeks prior to the onset of her presenting symptoms, she had visited a local pharmaceutical shop on account of a distressing epigastric discomfort and was subsequently placed on daily oral omeprazole 20mg daily for a month by a pharmacist. She had been on the omeprazole medication for two weeks before her present symptoms manifested. Her past medical history was not suggestive of hypoparathyroidism nor pancreatitis. She was married with three children and has an uneventful family, social and obstetric histories. On examination, she was a healthy well-oriented young female with positive Trousseau’s, Chvostek’s and epigastric tenderness signs. Further Laboratory evaluation revealed she had low plasma magnesium, low plasma albumin-corrected calcium, and low serum parathyroid hormone levels, while other laboratory parameters were essentially normal. A diagnosis of omeprazole-induced electrolyte disorders (hypomagnesaemia and hypocalcaemia) associated with hypoparathyroidism was made following the review of her clinical examination and laboratory findings. She was subsequently managed with oral magnesium supplements following the withdrawal of the omeprazole medication (replaced with oral ranitidine), monitored weekly, and full recovery was achieved after three weeks
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