The Very Low Head Turbine for hydropower generation in existing hydraulic infrastructures: State of the art and future challenges

The Very Low Head turbine (VLHT) is an axial flow turbine developed for heads below 4.5 m and flow rates up to 30 m3/s. In this work, the state of the art, the technological advancements and the scientific gaps were discussed and generalized, with a special focus on design, ecological behavior, costs, performance at different flows, heads and rotational speeds. The flow field and the hydraulic behavior under different configurations (e.g. in presence of cavitation and with an upstream obstacle) were described, with the aim of deriving engineering suggestions. Results of ecological tests were generalized (fish survival rate is more than 90%) by using the blade strike model, proposing an expeditious method for a preliminary appraisal of the ecological impact on downstream migrating fish. Despite the hundreds of installations worldwide, especially in existing barriers, some scientific gaps need to be better addressed yet, e.g., the influence of the number of blades and axis inclination on the efficiency, the influence of flow, head and rotational speed on the flow field and a quantification of the head losses through the trash rack above the runner

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

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

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

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

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 (<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>_org) 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>_org values. However, for each precursor, the <i>GF</i>_org 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>_org 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

Parental bonding styles in schizophrenia, depressive and bipolar patients: a comparative study

Background: Numerous bio-psychosocial factors play a role in the etiology of psychiatric disorders. In this regard, the relationship between parents and their children is significantly involved in developing the offspring mental health. However, there is no clear-cut answer as to which parental bonding style is more strongly associated with psychiatric diseases of patients. This study aimed to compare parental bonding styles in patients with schizophrenia, depression, and bipolar disorder in Bushehr province, Iran in 2018. Methods: In this cross-sectional comparative study, 130 patients with schizophrenia, depression, and bipolar disorder who referred to four outpatients psychiatric centers in Bushehr were selected using quota sampling. The patients were assessed and compared in terms of parental bonding styles. Data were collected using a valid and reliable parental bonding instrument (PBI). Data were analyzed using SPSS software (ver. 22), Chi-square and Kruskal-Wallis tests at a significant level of 0.05. Results: Results showed that the optimal parental bonding style (low control, high care) in bipolar disorder (43.05%), major depression (47.7%), and schizophrenia (38.5%) was the most prevalent style of parental bonding; however, 62.30% of the above patients suffered from inefficient paternal bonding styles and 51.53% from inefficient maternal bonding styles. Furthermore, the patients’ maternal bonding styles were significantly different (p = 0.007) while their paternal bonding styles did not show any significant differences (p = 0.848). Conclusions: Most of the patients with psychiatric disorders were affected by ineffective parenting styles. The results also confirmed that despite the several bio-psycho-social factors involved in the development of psychiatric disorders, the crucial roles of parents, especially mothers, should not be ignored. It was further suggested that parents and parental bonding were important and fundamental factors for mental health promotion

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

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

Modeling regional aerosol variability over California and its sensitivity to emissions and long-range transport during the 2010 CalNex and CARES campaigns

Abstract. The performance of the Weather Research and Forecasting regional model with chemistry (WRF-Chem) in simulating the spatial and temporal variations in aerosol mass, composition, and size over California is quantified using measurements collected during the California Nexus of Air Quality and Climate Experiment (CalNex) and the Carbonaceous Aerosol and Radiative Effects Study (CARES) conducted during May and June of 2010. The extensive meteorological, trace gas, and aerosol measurements collected at surface sites and along aircraft and ship transects during CalNex and CARES were combined with operational monitoring network measurements to create a single dataset that was used to evaluate the one configuration of the model. Simulations were performed that examined the sensitivity of regional variations in aerosol concentrations to anthropogenic emissions and to long-range transport of aerosols into the domain obtained from a global model. The configuration of WRF-Chem used in this study is shown to reproduce the overall synoptic conditions, thermally-driven circulations, and boundary layer structure observed in region that controls the transport and mixing of trace gases and aerosols. However, sub-grid scale variability in the meteorology and emissions as well as uncertainties in the treatment of secondary organic aerosol chemistry likely contribute to errors at a primary surface sampling site located at the edge of the Los Angeles basin. Differences among the sensitivity simulations demonstrate that the aerosol layers over the central valley detected by lidar measurements likely resulted from lofting and recirculation of local anthropogenic emissions along the Sierra Nevada. Reducing the default emissions inventory by 50% led to an overall improvement in many simulated trace gases and black carbon aerosol at most sites and along most aircraft flight paths; however, simulated organic aerosol was closer to observed when there were no adjustments to the primary organic aerosol emissions. The model performance for some aerosol species was not uniform over the region, and we found that sulfate was better simulated over northern California whereas nitrate was better simulated over southern California. While the overall spatial and temporal variability of aerosols and their precursors were simulated reasonably well, we show cases where the local transport of some aerosol plumes were either too slow or too fast, which adversely affects the statistics regarding the differences between observed and simulated quantities. Comparisons with lidar and in-situ measurements indicate that long-range transport of aerosols from the global model was likely too high in the free troposphere even though their concentrations were relatively low. This bias led to an over-prediction in aerosol optical depth by as much as a factor of two that offset the under-predictions of boundary-layer extinction resulting primarily from local emissions. Lowering the boundary conditions of aerosol concentrations by 50% greatly reduced the bias in simulated aerosol optical depth for all regions of California. This study shows that quantifying regional-scale variations in aerosol radiative forcing and determining the relative role of emissions from local and distant sources is challenging during "clean" conditions and that a wide array of measurements are needed to ensure model predictions are correct for the right reasons. In this regard, the combined CalNex and CARES datasets are an ideal testbed that can be used to evaluate aerosol models in great detail and develop improved treatments for aerosol processes

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]

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