Photonic band gap via quantum coherence in vortex lattices of Bose gases

We investigate the optical response of an atomic Bose-Einstein condensate with a vortex lattice. We find that it is possible for the vortex lattice to act as a photonic crystal and create photonic band gaps, by enhancing the refractive index of the condensate via a quantum coherent scheme. If high enough index contrast between the vortex core and the atomic sample is achieved, a photonic band gap arises depending on the healing length and the lattice spacing. A wide range of experimentally accessible parameters are examined and band gaps in the visible region of the electromagnetic spectrum are found. We also show how directional band gaps can be used to directly measure the rotation frequency of the condensate.Comment: 4 pages, 4 figures, Final version to appear in PR

A 5‑year audit of diagnostic gynaecologic laparoscopy under conscious sedation at the University College Hospital, Ibadan

Introduction: Diagnostic laparoscopy affords smaller incisions, shorter recovery time, and fewer complications. In developing countries, access is limited by cost, infrastructural deficit, and expertise. In a bid to reduce cost at our center, conscious sedation for diagnostic laparoscopy was introduced as far back as 1980. We present here a 5‑year audit of our outpatient diagnostic laparoscopy highlighting the various indications, findings, and complications observed. Methodology: A retrospective review of case files of patients who had diagnostic gynecological laparoscopy between 1st January 2011 and 31st December 2015. The retrieved case files had data extracted and analysed using the Statistical Package for Social Sciences version 20 (Chicago IL USA). Data was presented as simple percentages using tables and figures. Results: During the period, 1,329 outpatient gynecological procedures were performed with 207 diagnostic gynecologic laparoscopies (15.6%). Only 187 case notes were retrieved (retrieval rate of 90%). The mean age was 33.04 (±5.2) years, 84.5% (158) had post‑secondary education, and 69.0% (129) were nulliparous. Majority, 131 (70.0%), had laparoscopy and dye test, 26 (14.0%) had laparoscopy alone, and 30 (16.0%) had a combination of laparoscopy, dye test, and hysteroscopy. The commonest indications were secondary infertility (51.9%), primary infertility (24.1%), and chronic pelvic pain (11.2%). Common findings at laparoscopy were pelvic adhesions (53.5%), uterine fibroids (35.1%), and bilateral tubal blockage (30.3%). Normal findings were reported in only 19 patients (10.3%). Conclusion: Diagnostic laparoscopy under conscious sedation is cost‑effective and safe. It has very minimal complications when performed by skilled personnel. It is thus recommended for low resource settings with the view to avail low income patients the opportunity for endoscopic evaluation.Key words: Audit; conscious sedation; diagnostic laparoscopy; low income

Quantum theory of a vortex line in an optical lattice

We investigate the quantum theory of a vortex line in a stack of weakly-coupled two-dimensional Bose-Einstein condensates, that is created by a one-dimensional optical lattice. We derive the dispersion relation of the Kelvin modes of the vortex line and also study the coupling between the Kelvin modes and the quadrupole modes. We solve the coupled dynamics of the vortex line and the quadrupole modes, both classically as well as quantum mechanically. The quantum mechanical solution reveals the possibility of generating nonequilibrium squeezed vortex states by strongly driving the quadrupole modes.Comment: Minor changes in response to a referee repor

UTILIZATION OF ION-PAIR COMPLEX FORMATION FOR THE SPECTROPHOTOMETRIC DETERMINATION OF SOME ANTIDEPRESSANT DRUGS IN PHARMACEUTICAL FORMULATIONS

Objective: A new, simple and sensitive spectrophotometric method has been developed for the determination of some antidepressant drugs, namely desvenlafaxine (DSV), dapoxetine (DAP) and citalopram (CIT) in pharmaceutical formulations.Methods: The proposed method was based on the formation of yellow colored ion-pair complex between the studied drugs and two sulphonphthalein dyes viz., bromophenol blue (BPB), and bromothymol blue (BTB) in acidic medium. The optimizations of the reaction conditions were investigated. Beer's law limits, Sandell's sensitivity, correlation coefficient, detection, and quantification limits were calculated.Results: The formed complexes showed absorption maxima at 412 nm and 410 nm measured for all the drugs with BPB and BTB, respectively. The Job's method of continuous variations indicated that a single l: l ion-pair complex was formed. Calibration curves were linear over the concentration range of 0.8–11.4, 0.8–6.4 and 0.8–8.0 μg/ml for DSV, DAP and CIT, respectively.Conclusion: The proposed method has been applied successfully for the analysis of the investigated drugs in pure and in their dosage forms. No interference was observed from common excipients present in pharmaceutical formulations. The proposed method is suitable for quality control applications.Keywords: Desvenlafaxine, Dapoxetine, Citalopram, Sulphonphthalein dyes, Extraction spectrophotometry, Pharmaceutical formulation

Structural phase transitions of vortex matter in an optical lattice

We consider the vortex structure of a rapidly rotating trapped atomic Bose-Einstein condensate in the presence of a co-rotating periodic optical lattice potential. We observe a rich variety of structural phases which reflect the interplay of the vortex-vortex and vortex-lattice interactions. The lattice structure is very sensitive to the ratio of vortices to pinning sites and we observe structural phase transitions and domain formation as this ratio is varied.Comment: 4 pages, 3 figure

Vortex nucleation in Bose-Einstein condensates in an oblate, purely magnetic potential

We have investigated the formation of vortices by rotating the purely magnetic potential confining a Bose-Einstein condensate. We modified the bias field of an axially symmetric TOP trap to create an elliptical potential that rotates in the radial plane. This enabled us to study the conditions for vortex nucleation over a wide range of eccentricities and rotation rates.Comment: 4 pages 4 figure

Beyond the Landau Criterion for Superfluidity

According to the Landau criterion for superfluidity, a Bose-Einstein condensate flowing with a group velocity smaller than the sound velocity is energetically stable to the presence of perturbing potentials. We found that this is strictly correct only for vanishingly small perturbations. The superfluid critical velocity strongly depends on the strength and shape of the defect. We quantitatively study, both numerically and with an approximate analytical model, the dynamical response of a one-dimensional condensate flowing against an istantaneously raised spatially periodic defect. We found that the critical velocity $v_c$ decreases by incresing the strength of the defect $V_0$, up to to a critical value of the defect intensity where the critical velocity vanishes

Particulate Matter Emitted from Gravel Crushers and Their Health Impacts on Workers, Middle Governorate - Gaza, Palestine

Background: Particulate matter (PM) refers to discrete particles in ambient air that exist as either solid or liquid droplets. A crusher is a machine designed to crush and grind rocks or rubble resulting from construction waste, and convert it to materials can be re-used in the building and construction. Aim: To evaluate the level of PM10 air pollution in crushers plants, and their impacts on respiratory system health, vital signs and complete blood count for crushers workers. Material and Methods: Case-control study was conducted during the period from April to August 2013 on all gravel crushers at Middle Gaza Governorates. 87 individuals participated, case (exposed) and control (non exposed) groups contain 40, 47 respectively. Pm10 concentration level was measured in the six crushers, and all participants were subjected to questionnaire, vital signs measuring, and complete blood counts Results: Results showed that an average of particulate matter contributions is 15153 μg/m3, which is about 100 times higher than PM10 existing standard of 150 μg/m3. As well as, it showed clear links between PM10 exposure and respiratory health, vital signs, and white blood cells among exposed group. Cough, dyspnea and sputum buildup were more common among the exposed group 100%, 97.5%, and 82,5% respectively, the non exposed group 14.9%, 31,9%, and 28.6%, respectively. Increasing in white blood cells count and Vital signs disturbances (Increasing systolic and diastolic blood pressure, increasing pulse rate, increasing respiratory rate and temperature) reported significantly among the exposed workers. Conclusions: PM10 concentration level in crushers plants were much higher than the existing standard. Occupational exposure to PM10 leads to higher prevalence of respiratory symptoms, vital signs disturbance, and increasing WBCs. Recommendations: Environmental and engineering control of PM10 emissions, protective techniques, procedures, measures and equipment and periodic medical examinations