93 research outputs found

    Single-layer-coated beam splitters for the division-of-amplitude photopolarimeter

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    A design procedure is presented for a near-optimal, single-layer-coated prism beam splitter that serves as the key optical element of the division-of-amplitude photopolarimeter (DOAP). For given film and substrate refractive indices, the angle of incidence and film thickness are selected such that the ellipsometric differential phase shifts in reflection and transmission Delta_r and Delta_t differ by ±pi/2, and the normalized determinant of the instrument matrix is maximized. The best results are obtained by using high-index films on low-index substrates. This is illustrated by examples of ZnS and GaP films on silica prisms in the visible and Si, Ge, and PbTe films on Irtran 1 substrates in the infrared. A 16° Si-prism DOAP beam splitter at the 1.55-µm lightwave-communications wavelength is also presented. It uses a 163-nm SiO2 coating on the entrance face to satisfy the optimum delta condition at 73° incidence, and the determinant of the instrument matrix is 78.23% of its theoretical maximum. The exit face of the Si prism is antireflection coated with a 208-nm Si3N4 film

    Single-layer-coated beam splitters for the division-of-amplitude photopolarimeter

    Get PDF
    A design procedure is presented for a near-optimal, single-layer-coated prism beam splitter that serves as the key optical element of the division-of-amplitude photopolarimeter (DOAP). For given film and substrate refractive indices, the angle of incidence and film thickness are selected such that the ellipsometric differential phase shifts in reflection and transmission Delta_r and Delta_t differ by ±pi/2, and the normalized determinant of the instrument matrix is maximized. The best results are obtained by using high-index films on low-index substrates. This is illustrated by examples of ZnS and GaP films on silica prisms in the visible and Si, Ge, and PbTe films on Irtran 1 substrates in the infrared. A 16° Si-prism DOAP beam splitter at the 1.55-µm lightwave-communications wavelength is also presented. It uses a 163-nm SiO2 coating on the entrance face to satisfy the optimum delta condition at 73° incidence, and the determinant of the instrument matrix is 78.23% of its theoretical maximum. The exit face of the Si prism is antireflection coated with a 208-nm Si3N4 film

    Exploring the impacts of education and unemployment on CO2 emissions

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    The role of human capital and unemployment has been debated in a limited number of empirical studies that have aimed to study the discipline of environmental sustainability. Therefore, by Employing a reliable autoregressive distributed lag (ARDL) model approach, this study examines the dynamic linkage between education, unemployment, and CO2 emissions, by using the Chinese economy’s dataset from the time period pertaining to 1991–2020. The vivacious side of human capital shows that variables such as literacy rate and the average year of schooling curb CO2 emissions in the long run. Moreover, Human capital results are also based on facts in terms of their magnitude and direction. Also, empirical findings have unfolded that unemployment significantly increases CO2 emissions in the longrun. However, the short-run has estimated that the coefficients of education and unemployment provide similar results. Based on these novel findings, a wide set of economic policies are required and hence suggested for maintaining the environmental quality

    Evolution of VANETS to IoV: Applications and Challenges

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    Advancement in wireless communication technology along with the evolution of low power computational devices, have given rise to the Internet of things paradigm. This paradigm is transforming conventional VANETs into Internet-of- vehicles. This transition has led to a substantial commercial interest; as a result, there has been a significant boost in the field of the Internet of vehicles during the past few years. IoV promises a wide range of applications of commercial interest as well as public entertainment and convenience (collision warning systems, on-demand in-car entertainment, smart parking, traffic information). Applications related to vehicular and passenger safety are particularly of great commercial as well as a research interest as such IoV is going to be a core component in implementing the smart city concept. This paper gives an overview of the transition of conventional VANETs to IoV and highlights the potential applications and challenges faced by the Internet of Vehicles (IoV) paradigm

    Synthesis, characterization and preliminary pharmacological evaluation of new non-steroidal anti-inflammatory pyrazoline derivatives

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    A series of six pyrazoline ring derivatives as a pharmacophore were incorporated to the naproxen; to increase its size were synthesized and preliminarly evaluated as anti-inflammatory agents with expected selectivity toward COX-2 enzyme. In vivo acute anti-inflammatory effects of the final compounds (5a-f) were evaluated in rats using egg-white induced edema model of inflammation. The tested compounds and the reference drug (naproxen) produced significant reduction of paw edema with respect to the effect of control group (propylene glycol 50%, v:v). However, compound 5d and 5e show comparable effect to naproxen at all experimental time while compounds 5a, 5b and 5c produced significantly lower inhibitory effect than naproxen at time 120-240 minutes. Furthermore, compound 5f exert significantly higher paw edema reduction than naproxen at 60-240 min. Also the antibacterial activities of the final compounds were evaluated by Well Diffusion Method. All tested compounds exert significant antibacterial activity against tested Gram positive and Gram negative bacteria in comparison to dimethyl sulfoxide as control group. In comparison the antibacterial results among the tested compound 5e may regard the best one and compound 5c the lower one

    The key roles of salicylic acid and sulfur in plant salinity stress tolerance

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    The salinization of agriculture soils over the globe has become one of the most devastating stresses and is significantly limiting cultivated land area, and crop productivity and quality. It is very imperative to explore both salinity tolerance in plants and insights into approaches (and underlying mechanisms) for effectively controlling salinity impacts. To this end, the role of phytohormone salicylic acid (SA) and plant nutrient sulfur (S) in promoting salinity tolerance has been researched in isolated studies, and SA–S interaction results have been little discussed. Given this, taking into account recent literature on SA, S and soil salinity, this paper aimed to (i) overview of the major impacts of soil salinity on plant health; (ii) highlight the significance of SA and S in improving plant salinity tolerance; (iii) discuss the role and underlying mechanism of SA, S and their interaction in the modulation of plant growth and development under salinity stress; and also to (iv) appraise the discussed literature and enlighten the major prospects

    A cross-sectional study for assessment of menopausal symptoms and coping strategies among Jordanian women of 40-60 years age group

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    Background: Menopause typically occurs between the ages of 45 and 55 and can significantly impact a woman's quality of life. Understanding the prevalence of menopausal symptoms and the strategies of coping with them is crucial for developing targeted interventions that address their unique needs. Methods: This cross-sectional study targeted the Jordanian women aged 40-60 through online questionnaire during January 2023-June 2023. The menopause rating scale (MRS) was utilized to assess the severity of menopausal symptoms, including somatic, psychological, and urogenital domains. Results: The study included a total of 309 successfully completed participations by women from different socio-economic and educational backgrounds in Jordan. The analysis revealed a high prevalence of menopausal symptoms among the participants. The severity of symptoms varied; moderate to severe symptoms, were appreciable across the various domains. The coping strategies employed by the participants were multifaceted. Unfortunately, a proportion of participants admitted to using ineffective coping mechanisms, such as tobacco and excessive caffeine consumption. In general, the study revealed that there is an evident shortage in the overall awareness among women. Conclusions: The findings emphasize the necessity of comprehensive interventions to enhance the well-being of women and consequently the society. The qualitative and the quantitative aspects of the study shall contribute valuable perceptions to both of the academia and the authorized healthcare institutes.  

    Iron Permeable Reactive Barrier for Removal of Lead from Contaminated Groundwater

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    The possibility of using zero-valent iron as permeable reactive barrier in removing lead from a contaminated groundwater was investigated. In the batch tests, the effects of many parameters such as contact time between adsorbate and adsorbent (0-240 min), initial pH of the solution (4-8), sorbent dosage (1-12 g/100 mL), initial metal concentration (50-250 mg/L), and agitation speed (0-250 rpm) were studied. The results proved that the best values of these parameters achieve the maximum removal efficiency of Pb+2 (=97%) were 2 hr, 5, 5 g/100 mL, 50 mg/L and 200 rpm respectively. The sorption data of Pb+2 ions on the zero-valent iron have been performed well by Langmuir isotherm model in compared with Freundlich model under the studied conditions. Finite difference method and computer solutions (COMSOL) multiphysics 3.5a software based on finite element method were used to simulate the one-dimensional equilibrium transport of lead through sand aquifer with and without presence of barrier. The predicted and experimental results proved that the reactive barrier plays a potential role in the restriction of the contaminant plume migration and a reasonable agreement between these results was recognized
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