101 research outputs found
Comparison between Low Flow Indices Using FL Approach and Low Flow Frequency Curve (A Case Study of Gharesou River Catchment)
Selection of low flow is necessary for water resource management, water supply planning, and watershed ecosystem restoration. In this study, FL approach was used, which is based on minimum flows and flow duration curve (Q80) categories. This approach was compared with the conventional 7Q10Â approach used in low flow selection. For this purpose, the daily flow series from Gharesou catchment was applied. Low flow frequency analysis related to 7Q10Â approach was done by fitting various distribution functions and using three frequency software, including HYFA, SMADA, and Easy fit. The results of both approaches show that low flows increased as time elapsed and the recurrence probability of low flow increased while the recurrence interval of low flow decreased as time elapsed. In addition, a low flow decline from 1971 to 2000 observed as 1.57 m3/s and 2.46 m3/s for 7Q10Â and FL approaches respectively. The 7Q10Â approach lead to selecting extremely low flows (approximately zero). The FL approach used in this study, could result in selecting low flows, considering role of the environment and minimum flow to protect the ecosystem of the catchment
Characterizations of continuous distributions through inequalities involving the expected values of selected functions
summary:Nanda (2010) and Bhattacharjee et al. (2013) characterized a few distributions with help of the failure rate, mean residual, log-odds rate and aging intensity functions. In this paper, we generalize their results and characterize some distributions through functions used by them and Glaser's function. Kundu and Ghosh (2016) obtained similar results using reversed hazard rate, expected inactivity time and reversed aging intensity functions. We also, via -function defined by Cacoullos and Papathanasiou (1989), characterize exponential and logistic distributions, as well as Type 3 extreme value distribution and obtain bounds for the expected values of selected functions in reliability theory. Moreover, a bound for the varentropy of random variable is provided
The impact of climate change on water and energy security
Abstract
The interdependent fundamental systems, water and energy, face abundant challenges, one of which is climate change, which is expected to aggravate water and energy securities. The hydropower industry's benefits have led to its development and growth around the world. Nonetheless, climate change is expected to disturb the future performance of hydropower plants. This study looks at the Seimareh Hydropower Plant to assess the potential vulnerability of hydropower plants to climate change. Results indicate that climate change will affect the area's hydrological variables and suggest an increase in temperatures and decrease in precipitation during a 30-year future period (2040â2069). It is predicted that Seimareh Dam's inflow will decrease by between 5.2% and 13.4% in the same period. These hydrological changes will affect the Seimareh plant's performance: current predictions are that the total energy produced will decrease by between 8.4% and 16.3%. This research indicates the necessity of considering climate change impacts in designing and maintaining hydraulic structures to reach their optimal performance
Prediction of Post Traumatic Growth based on Secular Attachment and its Components in Married Patients with Blood Cancer
For downloading the full-text of this article please click here.Background and Objective: Several empirical studies reported links between religion, spirituality, and post-traumatic growth. Post-traumatic growth has been reported after traumatic events such as medical conditions (such cancer or HIV). The purpose of the present study was to predict posttraumatic growth based on material attachment and its components in married patients with blood cancer.Methods: The statistical population included all the patients who referred to both inpatients and outpatientsâ centers in Namazi hospital and Motahhari clinic in Shiraz, Iran, in 2018. 124 patients were selected from the sample population using convenient sampling method. The measures used included Posttraumatic Growth Inventory and Material Attachment Inventory. Pearson correlation coefficient and regression analysis were used for analyzing the data. In this study, all the ethical considerations have been observed and no conflict of interest was reported by the authors.Results: The findings showed that material attachment could predict posttraumatic growth negatively (P<0.05). In addition, among the material attachment questionnaire components, "attachment to the present condition" could more strongly predict posttraumatic growth.Conclusion: It is concluded that the strategies that distance the patients with blood cancer from all material attachments and attachment to the present condition can facilitate posttraumatic growth.For downloading the full-text of this article please click here.Please cite this article as: Mousavi SZ, Goodarzi MA, Taghavi SMR.Prediction of Post Traumatic Growth based on Secular Attachment and its Components in Married Patients with Blood Cancer. Journal of PizhĆ«hish dar dÄ«n va salÄmat. 2020;6(2):37-48.https://doi.org/10.22037/jrrh.v6i2.2255
The Incidence and Geographical Distribution of Brucellosis in Iran Using Geographic Information System and Prediction of its Incidence in 2021
Background: Brucellosis is one of the most challenging health issues in many developing countries including Iran. The purpose of this study is to investigate the incidence and geographical distribution of brucellosis using Geographic Information System (GIS) and to predict its incidence in Iran in 2021.
Method: This is a descriptive-analytical cross-sectional study, which contains spatial and climatic information along with the prevalence rate of brucellosis in Iran. Disease information was obtained from the National Center for Infectious Diseases Management during 2011-2015. Then, Arc GIS version 9.3 was used to plot the geographical maps for the incidence and frequency of the disease. Using the Raster calculator tool, the disease prediction map for the future was plotted. For proper spatial distribution of hot and cold spots, Getis-Ord-Gi statistic was employed.
Results: The highest incidence of brucellosis during 2009-2015 was observed in the western provinces of Iran (North Khorasan, South Khorasan and Razavi Khorasan provinces). The incidence of brucellosis in Iran decreased from 2009 to 2011 but it exhibited an increasing trend from 2011 to 2014. The provinces of Kurdistan, Lorestan, Ilam, Zanjan and Kermanshah may be among the hot spots in terms of brucellosis incidence in 2021.
Conclusion: We predicted significant variations in brucellosis risk distribution in Iran in the coming years. In the western and northwestern provinces, which are among the high risk areas for the incidence of this disease in the future, this disease can pose a serious health threat to the residents of these areas
Mathematical Modeling for Nanofluids Simulation: A Review of the Latest Works
Exploiting nanofluids in thermal systems is growing day by day. Nanofluids having ultrafine solid particles promise new working fluids for application in energy devices. Many studies have been conducted on thermophysical properties as well as heat and fluid flow characteristics of nanofluids in various systems to discover their advantages compared to conventional working fluids. The main aim of this study is to present the latest developments and progress in the mathematical modeling of nanofluids flow. For this purpose, a comprehensive review of different nanofluid computational fluid dynamics (CFD) approaches is carried out. This study provides detailed information about the commonly used formulations as well as techniques for mathematical modeling of nanofluids. In addition, advantages and disadvantages of each method are rendered to find the most appropriate approach, which can give valid results
Pathogen Identification in Suspected Cases of Pyogenic Spondylodiscitis
Pyogenic spinal infection continues to represent a worldwide problem. In approximately one-third of patients with pyogenic spondylodiscitis, the infectious agent is never identified. Of the cases that lead to organismal identification, bacteria are more commonly isolated from the spine rather than fungi and parasites. This study applied universal prokaryotic 16S rRNA PCR as a rapid diagnostic tool for the detection of bacterial agents in specimens from patients suspected of pyogenic spondylodiscitis. Gram and Ziehl-Neelsen staining were used as a preliminary screening measure for microbiologic evaluation of patient samples. PCR amplification targeting 16S rRNA gene was performed on DNA extracted from 57 cases including specimens from epidural abscesses, vertebral, and disc biopsies. Positive samples were directly sequenced. MRI findings demonstrated that disc destruction and inflammation were the major imaging features of suspected pyogenic spondylodiscitis cases, as 44 cases showed such features. The most common site of infection was the lumbar spine (66.7%), followed by thoracic spine (19%), the sacroiliac joint (9.5%), and lumbar-thoracic spine (4.8%) regions. A total of 21 samples amplified the 16S rRNA-PCR product. Sanger sequencing of the PCR products identified the following bacteriological agents: Mycobacterium tuberculosis (n = 9; 42.9%), Staphylococcus aureus (n = 6; 28.5%), Mycobacterium abscessus (n = 5; 23.8%), and Mycobacterium chelonae (n = 1; 4.8%). 36 samples displayed no visible 16S rRNA PCR signal, which suggested that non-bacterial infectious agents (e.g., fungi) or non-infectious processes (e.g., inflammatory, or neoplastic) may be responsible for some of these cases. The L3âL4 site (23.8%) was the most frequent site of infection. Single disc/vertebral infection were observed in 9 patients (42.85%), while 12 patients (57.15%) had 2 infected adjacent vertebrae. Elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) inflammatory markers were noted in majority of the patients. In conclusion, microbiological methods and MRI findings are vital components for the proper diagnosis of pyogenic spondylodiscitis. Our findings suggest that molecular methods such as clinical application of 16S rRNA PCR and sequencing may be useful as adjunctive diagnostic tools for pyogenic spondylodiscitis. The rapid turnaround time of 16S rRNA PCR and sequencing submission and results can potentially decrease the time to diagnosis and improve the therapeutic management and outcome of these infections. Although S. aureus and M. tuberculosis were the most common causes of pyogenic spinal infections in this study, other infectious agents and non-infectious etiologies should be considered. Based on study results, we advise that antibiotic therapy should be initiated after a definitive etiological diagnosis
Two-phase frictional pressure drop with pure refrigerants in vertical mini/micro-channels
Environmental concerns have urged a search for eco-friendly refrigerants in the refrigeration industry to overcome ozone depletion and global warming problems. Therefore, current research emphasizes frictional pressure drop during flow boiling of environment-friendly refrigerants (GWP\u3c150), isobutane, HFC-152a, HFO-1234yf were tested against commonly reported HFC-134a. The data presented here was collected under heat flux-controlled conditions; the test piece was a round tube (1.60 mm diameter). The data collection was performed at 27 and 32 °C with mass velocities in 50-500 kg/m2s range. Effects of critical controlling parameters, like heat flux, mass velocity, exit vapor quality, operating pressure and medium, were studied in detail. It was observed that pressure drop increases along with mass velocity increment in the test piece and increases with exit vapor quality increment. The same was noticed to decrease with saturation temperature increment. Parametric effects and prediction of assessment methods are reported
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