224 research outputs found

    Investigation of Natural Effective Gamma Dose Rates case study: Ardabil Province in Iran

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    Gamma rays pose enough energy to form charged particles and adversely affect human health. Since, the external exposure of human beings to natural environmental gamma radiation normally exceeds that from all man-made sources combined, natural background gamma dose rates and corresponding annual effective doses were determined for selected cities of Ardabil province from 2009 to 2010. Outdoor gamma dose rates were measured using an Ion Chamber Survey Meter in 105 locations in selected districts. Average absorbed dose for Ardabil, Sar-Ein, Germy, Neer, Shourabil Recreational Lake, and Kosar were determined as 265, 219, 344, 233, 352, and 358 nSvh-1, respectively. Although dose rates recorded for Germi and Kosar are comparable with some areas with high natural radiation background, however, the dose rates in other districts are well below the levels reported for such locations. Average annual effective dose due to indoor and outdoor gamma radiation for Ardabil province was estimated to be 1.73 (1.35-2.39) mSv, which is on average 2 times higher than the world population weighted average

    The relationship between nurses' clinical competency and job stress in Ahvaz university hospital, 2013

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    زمینه و هدف: صلاحیت بالینی پرستاری، شایستگی کاربرد همزمان دانش، مهارت، نگرش ها و ارزش ها در مراقبت از بیمار است که به دلیل اهمیت آن اخیراً مورد توجه بیشتری قرار گرفته است. با توجه به اهمیت روز افزون موضوع صلاحیت پرستاری، شناخت عوامل مرتبط با آن و از جمله استرس شغلی ضروری به نظر می رسد؛ لذا مطالعه حاضر با هدف تعیین رابطه صلاحیت بالینی و استرس شغلی پرستاران شاغل در بیمارستان های دانشگاهی شهر اهواز در سال1392 انجام شد. روش بررسی: در این پژوهش توصیفی- تحلیلی که به صورت مقطعی در طی سال 1392 انجام شد، 80 نفر پرستار شاغل در بیمارستان های آموزشی شهر اهواز از طریق نمونه گیری تصادفی انتخاب و وارد مظالعه شدند. ابزار گردآوری داده ها شامل پرسشنامه های استرس شغلی Osipow و پرسشنامه صلاحیت بالینی Benner بود که به صورت خود ایفاء تکمیل گردیدند. میزان صلاحیت بالینی پرستاران ارزیابی و ارتباط آن با استرس شغلی تعیین شد. یافته ها: بیشتر پرستاران (3/81 درصد) دارای استرس شغلی متوسط بودند. میانگین نمره کل صلاحیت بالینی پرستاران 48/18± 15/61 بود. آزمون همبستگی پیرسون نشان داد که بین استرس شغلی و صلاحیت بالینی پرستاران در تمام حیطه های آن همبستگی منفی و معنی داری وجود دارد (01/0>P). همچنین بین میزان استرس شغلی و بکارگیری صلاحیت بالینی کل ارتباط معنی داری وجود داشت (001/0>P). نتیجه گیری: بر اساس نتایج مطالعه حاضر، افزایش استرس شغلی پرستاران با کاهش صلاحیت های بالینی آنها رابطه دارد که بایستی مورد توجه مدیران پرستاری قرار گیرد

    Hygroscopicity of secondary organic aerosols formed by oxidation of cycloalkenes, monoterpenes, sesquiterpenes, and related compounds

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    A series of experiments has been conducted in the Caltech indoor smog chamber facility to investigate the water uptake properties of aerosol formed by oxidation of various organic precursors. Secondary organic aerosol (SOA) from simple and substituted cycloalkenes (C5-C8) is produced in dark ozonolysis experiments in a dry chamber (RH~5%). Biogenic SOA from monoterpenes, sesquiterpenes, and oxygenated terpenes is formed by photooxidation in a humid chamber (~50% RH). Using the hygroscopicity tandem differential mobility analyzer (HTDMA), we measure the diameter-based hygroscopic growth factor (GF) of the SOA as a function of time and relative humidity. All SOA studied is found to be slightly hygroscopic, with smaller water uptake than that of typical inorganic aerosol substances. The aerosol water uptake increases with time early in the experiments for the cycloalkene SOA, but decreases with time for the biogenic SOA. This behavior could indicate competing effects between the formation of more highly oxidized polar compounds (more hygroscopic), and formation of longer-chained oligomers (less hygroscopic). All SOA also exhibit a smooth water uptake with RH with no deliquescence or efflorescence. The water uptake curves are found to be fitted well with an empirical three-parameter functional form. The measured pure organic GF values at 85% RH are between 1.09–1.16 for SOA from ozonolysis of cycloalkenes, 1.01–1.04 for sesquiterpene photooxidation SOA, and 1.06–1.11 for the monoterpene and oxygenated terpene SOA. The GF of pure SOA (GForg) in experiments in which inorganic seed aerosol is used is determined by assuming volume-weighted water uptake (Zdanovskii-Stokes-Robinson or ''ZSR'' approach) and using the size-resolved organic mass fraction measured by the Aerodyne Aerosol Mass Spectrometer. Knowing the water content associated with the inorganic fraction yields GForg values. However, for each precursor, the GForg values computed from different HTDMA-classified diameters agree with each other to varying degrees. Lack of complete agreement may be a result of the non-idealities of the solutions that are not captured by the ZSR method. Comparing growth factors from different precursors, we find that GForg is inversely proportional to the precursor molecular weight and SOA yield, which is likely a result of the fact that higher-molecular weight precursors tend to produce larger and less hygroscopic oxidation products

    Hygroscopicity of secondary organic aerosols formed by oxidation of cycloalkenes, monoterpenes, sesquiterpenes, and related compounds

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    A series of experiments has been conducted in the Caltech indoor smog chamber facility to investigate the water uptake properties of aerosol formed by oxidation of various organic precursors. Secondary organic aerosol (SOA) from simple and substituted cycloalkenes (C<sub>5</sub>-C<sub>8</sub>) is produced in dark ozonolysis experiments in a dry chamber (<i>RH</i>~5%). Biogenic SOA from monoterpenes, sesquiterpenes, and oxygenated terpenes is formed by photooxidation in a humid chamber (~50% <i>RH</i>). Using the hygroscopicity tandem differential mobility analyzer (HTDMA), we measure the diameter-based hygroscopic growth factor (<i>GF</i>) of the SOA as a function of time and relative humidity. All SOA studied is found to be slightly hygroscopic, with smaller water uptake than that of typical inorganic aerosol substances. The aerosol water uptake increases with time early in the experiments for the cycloalkene SOA, but decreases with time for the sesquiterpene SOA. This behavior could indicate competing effects between the formation of more highly oxidized polar compounds (more hygroscopic), and formation of longer-chained oligomers (less hygroscopic). All SOA also exhibit a smooth water uptake with <i>RH</i> with no deliquescence or efflorescence. The water uptake curves are found to be fitted well with an empirical three-parameter functional form. The measured pure organic <i>GF</i> values at 85% <i>RH</i> are between 1.09&ndash;1.16 for SOA from ozonolysis of cycloalkenes, 1.01&ndash;1.04 for sesquiterpene photooxidation SOA, and 1.06&ndash;1.10 for the monoterpene and oxygenated terpene SOA. The <i>GF</i> of pure SOA (<i>GF</i><sub>org</sub>) in experiments in which inorganic seed aerosol is used is determined by assuming volume-weighted water uptake (Zdanovskii-Stokes-Robinson or 'ZSR' approach) and using the size-resolved organic mass fraction measured by the Aerodyne Aerosol Mass Spectrometer. Knowing the water content associated with the inorganic fraction yields <i>GF</i><sub>org</sub> values. However, for each precursor, the <i>GF</i><sub>org</sub> values computed from different HTDMA-classified diameters agree with each other to varying degrees. Comparing growth factors from different precursors, we find that <i>GF</i><sub>org</sub> is inversely proportional to the precursor molecular weight and SOA yield, which is likely a result of the fact that higher-molecular weight precursors tend to produce larger and less hygroscopic oxidation products

    The evolution of business relationships between technology-intensive new ventures and incumbents during the new product development process

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    This study investigates how technology-intensive new ventures shape and manage their relationships with incumbents to successfully develop new products. We undertake the dynamic views of business relationship to reveal under what conditions new ventures should emphasize more on transactional contract or alliance approach to develop their relationships with incumbents. Using longitudinal multiple case analysis, we show that transactional contract is less effective during discovery and development stages to facilitate knowledge share and collaborative learning between new ventures and incumbents. However, adopting transactional contract is essential during commercialization to strengthen the relationship, minimize the drawbacks of social bonds, and motivate both parties to engage in new projects. The results show that tensions between exchange partners are likely to increase when the incumbent is flexible to re-negotiate and share the fair benefits during the commercialization stage. Our findings provide new insights about the evolution of new ventures’ relationships with incumbents across NPD stages

    Assessing the Mediating Role of Depression in the Relationship Between Feeling of Loneliness and Social Functioning in the Elderly [بررسی نقش میانجی افسردگی در ارتباط بین احساس تنهایی با عملکرد اجتماعی سالمندان شهر بوشهر]

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    Objectives Due to the rapid growth of the elderly population, it is very important to pay attention to their mental health indicators including feeling of loneliness, social functions and depression. This study aims to determine the mediating role of depression in the relationship between feeling of loneliness and social functioning in the elderly. Methods & Materials In this correlational cross-sectional study, 318 older adults covered by the comprehensive health centers in Bushehr, south of Iran in 2018 were selected using a simple random sampling method. To collect data, Russell’s UCLA loneliness scale (version 3), and Goldberg’s general health questionnaire (Depression and social dysfunction subscales) were used. We applied the partial least squaresstructural equation modeling to analyze the data in PLS Graph version 3.00 software. The significance level was set at 0.05. Results The mean age of the participants was 66.74±5.87 years; 55.3% were male and the rest were female. The results showed that feeling of loneliness directly (β=0.199, P<0.01) and through mediation by depression (β=0.183, P<0.001) could cause social dysfunction. Felling of loneliness and depression together explained 20% of the variance in social dysfunction. The outer and inner model fit indices indicated the models’ good fit. Conclusion Feeling of loneliness directly or by causing depression can reduce the social functioning of the elderly. The results of this study can be used in designing effective interventions to increase the social functioning of the elderly © 2022, Iranian Journal of Ageing.All Rights Reserved

    The permeability and selectivity of nanocomposite membrane of PEBAx 1657/PEI/SiO2 for separation of CO2, N2, O2, CH4 gases: A data set

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    The poly ether-block-amide (PEBAx)/Poly-ether-imide (PEI)/SiO2 nanocomposite membranes were fabricated using the solution casting method and utilized for separation of N2, O2, CH4, and CO2 gases. The effect of SiO2 nanoparticles loading on permeability and selectivity of gases using the nanocomposite membranes was tested. The data showed that the permeability of the gases increased with increasing SiO2 nanoparticle content. dBy adding SiO2 nanoparticles (10 wt%), the permeability of N2, O2, CH4, and CO2 gases elevated from 0.39, 1, 1.83 and 11.1 to 2.01, 1.95, 2.98 and 19.83 Barrer unit, respectively (at a pressure of 2 Bar). In contrast, with increasing SiO2 content the selectivity of the studied gases decreased. The morphology, crystallinity and the functional groups of the fabricated membranes were evaluated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) techniques. The data presented confirm the influence of the nanoparticles on the membrane structure and thus on the permeability and selectivity of the membranes

    Uterus dysplasia associated with cervico-vaginal agenesis

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    Müllerian ducts can form upper parts of normal female reproductive system and any failure in ductal fusion may result in to müllerian duct anomalies (MDA). We present a case of MDA and a uterus dysplasia with no evidence of cervical or upper vaginal tissue. This case showes the role of magnetic resonace imaging (MRI) on MDA diagnosis and urges the need for a unified reliable and practical classification more compatible with clinical practice. © 2017, Royan Institute (ACECR). All rights reserved
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