Pair-correlation properties and momentum distribution of finite number of interacting trapped bosons in three dimension

We study the ground state pair-correlation properties of a weakly interacting trapped Bose gas in three dimension by using a correlated many-body method. Use of the van der Waals interaction potential and an external trapping potential shows realistic features. We also test the validity of shape-independent approximation in the calculation of correlation properties.Comment: Accepted for publication in The Journal of Chemical Physic

Stability of attractive bosonic cloud with van der Waals interaction

We investigate the structure and stability of Bose-Einstein condensate of $^{7}$Li atoms with realistic van der Waals interaction by using the potential harmonic expansion method. Besides the known low-density metastable solution with contact delta function interaction, we find a stable branch at a higher density which corresponds to the formation of an atomic cluster. Comparison with the results of non-local effective interaction is also presented. We analyze the effect of trap size on the transition between the two branches of solutions. We also compute the loss rate of a Bose condensate due to two- and three-body collisions.Comment: 9 pages, 5 figure

Low-cost alternative renewable energy bioethanol production from palm oil in Malaysian context

Biofuels can be broadly defined as solids, liquids, or gas fuels consisting of, or derived from, plant biomass. Its use here is primarily with respect to a liquid transportation fuel (bioethanol or biodiesel). A major environmental issue being addressed by the global community is the sustainable supply of energy in parallel with a significant reduction in greenhouse gas emissions. This will be a significant technological and socioeconomic challenge because of our dependence on fossil fuel combustion for energy and the fact that it is this combustion that is the primary cause of greenhouse gas emissions

Prevalence and predictors of metabolic syndrome with comparison of myoinositol and metformin in PCOS women

Background: The objective is to determine the prevalence of metabolic syndrome (MBS) and the effects of insulin sensitizers to improve the clinical and hormonal milieu for better reproductive outcome in PCOS women.Methods: This prospective cross-sectional study was conducted on 50 PCOS women and 50 age matched control to determine the prevalence of the MBS in two tertiary hospitals over one year. Diagnosis of PCOS was based on at least two of ESHRE/ASRM criteria and diagnosis of MBS was based on at least three of NCEPATPIII criteria. Patients already diagnosed as PCOS were treated with insulin sensitizers myoionositol and metformin which were compared.Results: The study revealed that the prevalence of MBS was 40 % (20/50) nearly 4-fold higher than that of control groups. Among PCOS women, the most prevalent MBS factors were high BMI (52%) and low serum HDL-C (42%). The least prevalent factor was high fasting serum glucose level (16%). The resumption of spontaneous regular menstrual cycle and pregnancy rate in infertile groups of PCOS patients with myoionositol and metformin were 61% vs. 26% and 50% vs.91% respectively. The myoionositol group did not require any extra ovulating agents for pregnancy, while 7 out of 11 patients in metfromin group needed clomiphen citrate for ovulation induction to achieve pregnancy.  With myoinositol there is significant reduction of weight, BMI, LH/FSH ratio and fasting insulin level; whereas metformin shows decrement of weight and BMI only.Conclusions: The prevalence of MBS in PCOS is nearly 4 times in present study and there is significant improvement of symptom profile, weight, BMI and change of hormonal pattern in myoinositol group

Treatment of leather industrial effluents by filtration and coagulation processes

AbstractThis study focused on effluents characterization and accessing physical and chemical treatment by filtration and coagulation processes. The analysis results of the raw effluents reveal that the effluents were yellowish-brown color, having basic pH, very high values of BOD5, COD, TDS, TSS, TS and high concentrations of Cr, Na, SO42− and other organic and inorganic constituents. After settling and a subsequent filtration of raw tannery effluents through sand-stone, the filtered effluents were treated with various doses of FeCl3. The study observed that coagulant (FeCl3) of 150mg/L dose near neutral pH showed the best removal efficiencies for major physico-chemical parameters. The analysis results illustrate that most of the physical and chemical parameters were found well below the prescribed permissible limits for effluent discharged. The study suggests that untreated tannery effluents would be treated by a combined process consisting of settling, filtering and coagulating with FeCl3

Many-body approach to low-lying collective excitations in a BEC approaching collapse

An approximate many-body theory incorporating two-body correlations has been employed to calculate low-lying collective multipole frequencies in a Bose-Einstein condensate containing $A$ bosons, for different values of the interaction parameter $\lambda=\frac{Aa_{s}}{a_{ho}}$. Significant difference from the variational estimate of the Gross-Pitaevskii equation has been found near the collapse region. This is attributed to two-body correlations and finite range attraction of the realistic interatomic interaction. A large deviation from the hydrodynamic model is also seen for the second monopole breathing mode and the quadrupole mode for large positive $\lambda$.Comment: 8 pages, 2 figure

Destruction of attractive bosonic cloud due to high spatial coherence in tight trap

We study coherence of a trapped bosonic cloud with attractive finite-range interaction in a tight harmonic trap. One-body density and pair-distribution function in the ground state for different trap sizes are calculated. We also calculate healing length and the correlation length which signify the presence of high spatial coherence in a very tight trap leading to the destruction of the condensate for a fixed particle number. This is in marked variance with the usual collapse of the attractive metastable condensate when N > Ncr . Thus we investigate the critical frequency and critical size of the trap for the existence of attractive Bose-Einstein condensation. The finite-range interaction gives a nonlocal effect in the effective many-body potential, and we observe a high-density stable branch besides the known metastable branch. Moreover, the new branch shows universal behavior even in the very tight trap