Geometric phases for mixed states in interferometry

We provide a physical prescription based on interferometry for introducing the total phase of a mixed state undergoing unitary evolution, which has been an elusive concept in the past. We define the parallel transport condition that provides a connection-form for obtaining the geometric phase for mixed states. The expression for the geometric phase for mixed state reduces to well known formulas in the pure state case when a system undergoes noncyclic and unitary quantum evolution.Comment: Two column, 4 pages, Latex file, No figures, Few change

Reply to `Singularities of the mixed state phase'

The only difference between Bhandari's viewpoint [quant-ph/0108058] and ours [Phys. Rev. Lett. 85, 2845 (2000)] is that our phase is defined modulo $2\pi$, whereas Bhandari argues that two phases that differ by $2\pi n$, $n$ integer, may be distinguished experimentally in a history-dependent manner.Comment: 2 page

Performance of BFRP and GFRP Hollow Circular Steel columns subjected to axial compression loads

Recent research has been focused on rehabilitation and strengthening of deteriorated steel structures and bridges using Fiber Reinforced Polymer (FRP) materials. This paper deals with the behavior of FRP confinement of hollow steel sections subjected to axial compression loads. The load carrying capacity and buckling failure patterns of hallow steel sections strengthened by different FRP were studied experimentally. Numbers of circular hallow steel sections of same diameter with different L/D ratio test specimens were fabricated. Three different L/D ratio test specimens were used as control specimens. The different number of layers in FRP such as basalt (BFRP) and glass (GFRP) fabrics in different orientations has been fabricated. The effects of strengthened elements were observed under axial compression load. The load vz slenderness ratio, stress strain relationship, the ultimate load vz orientation and number of ply wrapping by different FRP were deeply analyzed and are plotted, tabulated and discussed. Besides local and overall buckling modes, failure patterns and rupturing of fiber of strengthened and non strengthened specimens were also observed. It is concluded that BFRP fabric wrapped by double layers in the circumferential direction elements withstand more axial compressive load than other strengthened and non strengthened elements

ORAL DIURETIC ACTIVITY OF HOT WATER EXTRACT OF H-GRADE QUILLS OF CINNAMOMUM ZEYLANICUM BLUME IN RATS

Objective: Cinnamomum zeylanicum Blume is claimed in Sri Lankan traditional medicine as a diuretic. Diuretics that are in current use possess serious adverse effects. Thus, there is a need for discovering efficacious and safe diuretics possibly from natural sources. Hence, the study was carried out to scientifically evaluate the diuretic potential of Cinnamomum zeylanicum Blume in vivo.Methods: Wistar albino rats weighing 180-270 g of either sex were divided into five groups containing six subjects in each. All were starved for 18 h and hydrated subsequently with oral sodium chloride solution (0.9%). Group, I (control) received normal saline (15 ml per animal orally). Group II, III, and IV received different doses (1500, 2250, 3000 mg/kg) of freeze-dried hot water extract of Cinnamomum zeylanicum Blume orally. Group V; (standard) received furosemide (13 mg/kg). Rats were placed individually in metabolic cages. Cumulative urine outputs at hourly intervals for six hours, urinary Na+, K+, Cl-, HCO3-, specific gravity, pH and total dissolved solids were determined. Results: A strong dose-dependent diuretic activity with a rapid onset of action, rapid peak diuresis and short duration of action was observed compared to furosemide. The diuretic action was accompanied with a significant (p<0.05) increase in urinary Na+, HCO3- and pH and decrease in urinary H+. Conclusion: The results indicated that hot water extract of Cinnamomum zeylanicum Blume possesses marked diuretic action compared to furosemide. This is mediated primarily via loop diuretic mechanism similar to furosemide and partly by carbonic anhydrase inhibitory action

Types of refractive errors in northern Pakistan: a hospital-based survey

Background: The World Health Organisation (WHO) reports that about 314 million people are visually impaired worldwide, and in 153 million of them the impairment is due to uncorrected refractive errors. Hence, uncorrected refractive error is one of the leading causes of blindness around the globe. The aim of this study is to assess the prevalence and patterns of different types of refractive errors among the people attending the eye clinic in Northern Pakistan. Material and methods: A hospital-based retrospective audit was done on patients who presented to the Ophthalmology Outpatients Department of Ayub Medical Complex Abbottabad between 1st June 2017 and 31st July 2017. The data of 662 patients were analysed using IBM SPSS Statistics v. 22.0. Results: Refractive errors were found in 487 (73.5%) of the total participants. The crude prevalence of myopia, hyperopia, and astigmatism was found to be 33.5%, 21.9%, and 18.1%, respectively. The refractive error status was found to be independent of gender (p = 0.075), but it varied among different age groups (p = 0.000). Conclusion: Myopia seems to be the most common refractive error in northern Pakistan, followed by hyperopia. The results of our study can be useful for the planning of eye care services in our country so that we can achieve the goal of VISION 2020 with proper care and planning