25 research outputs found
The Development of a New Model for Predictions of Urban Water Demand
Population growth, rapid urbanization and climate change have been producing an ever increasing stress on the limited resources of fresh water. This situation makes prediction models of water demand an important tool for decision making regarding urban water management and conservation. However, there is still the need for improvement of the predictions of the existing models, especially in their estimations of base water use. The purpose of this thesis is to develop a more reliable water demand prediction model which gives a better understanding of water use behaviour. The employed techniques represent a new approach to predictions of daily water use; its base use component is predicted using a function of socioeconomic factors, as opposed to a function of time as in existing approaches. The prediction by the model proposed in this thesis is compared with those by two other existing models, in an application to the city of Brossard in Quebec. Time series of predicted daily urban water use captures observed characteristics very well and improves the results of the weighted coefficient of determination, the relative index of agreement and the root mean square error from the existing approaches. Water use in the city exhibits a downward trend possibly due to an increasing annual charge for water use. The analysis procedures reported in this thesis can be applied to analyze water use in any other cities. The new approach would be a useful tool for decision makers to manage water use by adjusting water consumption policies and price
Changing in Thyroid Function Test in Children Underwent Antiepileptic Therapy
ObjectiveTo determine the changes in thyroid function tests in children who underwent antiepileptic therapy in Shahid Beheshti Hospital, Kashan, in 2008.Materials & MethodsThis analytical-observational study was carried out in a cohort fashion without an external control group (self controlled) on 45 children with new onset epilepsy who had not been previously treated with antiepileptic medications. Three subjects were excluded from the study because of presenting clinical symptoms of hypothyroidism. Plasma levels of TSH, T3, FT3, T4 and FT4 hormones were measured and compared at baseline and 3 and 6 months after treatment.ResultsThe results of Mann-Whitney statistical analysis suggested that the increase in the plasma level of TSH was significant only in the Sodium Valproate group.The plasma level of T3 significantly decreased 3 and 6 months after treatment in the Phenobarbital group while the plasma level of FT3 significantly decreased only in the Sodium Valproate group. The decrease in T4 plasma level was significant in all groups (Carbamazepine group, Sodium Valproate group and Phenobarbital group) 3 and 6 months after the onset of treatment but the decreasing in FT4 plasma level was only significant in the Carbamazepine group 6 months after the commencement of treatment.ConclusionPhenobarbital had the least effect on thyroid hormones. Considering the effect of such medications on thyroid function tests, it seems necessary to check the plasma levels of hormones periodically after beginning the treatment
Optimization of Water-Energy-Food Nexus considering CO2 emissions from cropland: A case study in northwest Iran
Water-Energy-Food (WEF) Nexus and CO2 emissions for a farm in northwest Iran were analyzed to provide data support for decision-makers formulating national strategies in response to climate change. In the analysis, inputâoutput energy in the production of seven crop species (alfalfa, barley, silage corn, potato, rapeseed, sugar beet, and wheat) was determined using six indicators, water, and energy consumption, mass productivity, and economic productivity. WEF Nexus index (WEFNI), calculated based on these indicators, showed the highest (best) value for silage corn and the lowest for potato. Nitrogen fertilizer and diesel fuel with an average of 36.8% and 30.6% of total input energy were the greatest contributors to energy demand. Because of the direct relationship between energy consumption and CO2 emissions, potato cropping, with the highest energy consumption, had the highest CO2 emissions with a value of 5166 kg CO2eq haâ1. A comparison of energy inputs and CO2 emissions revealed a direct relationship between input energy and global warming potential. A 1 MJ increase in input energy increased CO2 emissions by 0.047, 0.049, 0.047, 0.054, 0.046, 0.046, and 0.047 kg haâ1 for alfalfa, barley, silage corn, potato, rapeseed, sugar beet, and wheat, respectively. Optimization assessments to identify the optimal cultivation pattern, with emphasis on maximized WEFNI and minimized CO2 emissions, showed that barley, rapeseed, silage corn, and wheat performed best under the conditions studied.publishedVersio
Effect of water storage on ultimate tensile strength and mass changes of universal adhesives
The aim of the present study was to evaluate the influence of water storage on micro tensile strength (”TS) and mass changes (MC) of two universal adhesives.
10 disk-shaped specimens were prepared for each adhesive; Scotchbond Universal (SCU) All-Bond Universal (ABU) and Adper Single Bond 2 (SB2). At the baseline and after 1 day and 28 days of water storage, their mass were measured and compared to estimate water sorption and solubility. For ”TS test, 20 dumbbell shaped specimens were also prepared for each adhesive in two subgroups of 1 day and 28 days water storage.
MC was significantly lower for SCU and ABU than SB2 (P < 0.05) at both time intervals. In all three adhesives, the MC was significantly lower at 28 days compared to that at 1 day (P < 0.05). Similarly, ”TS was significantly higher for SCU and ABU than SB2 at both storage intervals (P < 0.05). After 28 days, ”TS increased significantly for universal adhesives (P < 0.05).
MC and ”TS of adhesives were both material and time dependent when stored in water; both universal adhesives showed less water sorption and higher values of ”TS than the control group
Association of vitamin D deficiency with COVID-19 severity and mortality in Iranian people: a prospective observational study
Background As the coronavirus disease 2019 (COVID-19) pandemic continues to escalate, it is important to identify the prognostic factors related to increased mortality and disease severity. To assess the possible associations of vitamin D level with disease severity and survival, we studied 248 hospitalized COVID-19 patients in a single center in a prospective observational study from October 2020 to May 2021 in Tehran, Iran. Methods Patients who had a record of their 25-hydroxyvitamin D level measured in the previous year before testing positive with COVID-19 were included. Serum 25-hydroxyvitamin D level was measured upon admission in COVID-19 patients. The associations between clinical outcomes of patients and 25-hydroxyvitamin D level were assessed by adjusting for potential confounders and estimating a multivariate logistic regression model. Results The median (interquartile range) age of patients was 60 years (44â74 years), and 53% were male. The median serum 25-hydroxyvitamin D level prior to admission decreased with increasing COVID-19 severity (P=0.009). Similar findings were obtained when comparing median serum 25-hydroxyvitamin D on admission between moderate and severe patients (P=0.014). A univariate logistic regression model showed that vitamin D deficiency prior to COVID-19 was associated with a significant increase in the odds of mortality (odds ratio, 2.01; P=0.041). The multivariate Cox model showed that vitamin D deficiency on admission was associated with a significant increase in risk for mortality (hazard ratio, 2.35; P=0.019). Conclusions: Based on our results, it is likely that deficient vitamin D status is associated with increased mortality in COVID-19 patients. Thus, evaluating vitamin D level in COVID-19 patients is warranted
Pulmonary manifestations in a cohort of patients with inborn errors of immunity : an 8-year follow-up study
Background: Inborn errors of immunity (IEIs) are a group of congenital diseases caused by genetic defects in the development and function of the immune system. The involvement of the respiratory tract is one of the most common presentations in IEIs. Methods: Overall, 117 patients with diagnosed IEIs were followed-up within 8 years at the National Research Institute of Tuberculosis and Lung Diseases (NRITLD). Demographic, clinical, and laboratory data were collected in a questionnaire. Pulmonary function test (PFT), chest X-ray (CXR), and high-resolution computed tomography (HRCT) scans were obtained where applicable. Results: Our study population consisted of 48 (41%) patients with predominantly antibody deficiencies (PADs), 39 (32%) patients with congenital defects of phagocytes, 14 (11.9%) patients with combined immunodeficiency (CID), and 16 (14%) patients with Mendelian susceptibility to mycobacterial diseases (MSMD).. Recurrent pneumonia was the most common manifestation, while productive cough appeared to be the most common symptom in almost all diseases. PFT showed an obstructive pattern in patients with PAD, a restrictive pattern in patients with CID, and a mixed pattern in patients with CGD. HRCT findings were consistent with bronchiectasis in most PAD patients, whereas consolidation and mediastinal lesions were more common in the other groups. Conclusions: Pulmonary manifestations vary among different groups of IEIs. The screening for lung complications should be performed regularly to reveal respiratory pathologies in early stages and follow-up on already existing abnormalities. (C) 2022 Codon Publications. Published by Codon Publications.Peer reviewe
Water Transfer As A Solution To Water Shortage: A Fix That Can Backfire
Zayandeh-Rud River Basin is one of the most important basins in central Iran, which has been continually challenged by water stress during the past 60. years. Traditionally, a supply-oriented management scheme has been prescribed as a reliable solution to water shortage problems in the basin, resulting in a number of water transfer projects that have more than doubled the natural flow of the river. The main objective of this study is to evaluate the reliability of inter-basin water transfer to meet the growing water demand in Zayandeh-Rud River Basin. A system dynamics model is developed to capture the interrelationships between different sub-systems of the river basin, namely the hydrologic, socioeconomic, and agricultural sub-systems. Results from simulating a range of possible policy options for resolving water shortage problems indicate that water is essentially the development engine of the system. Therefore, supplying more water to the basin without considering the dynamics of the interrelated problems will eventually lead to increased water demand. It is demonstrated that the Zayandeh-Rud River Basin management system has characteristics of the Fixes that Backfire system archetype, in which inter-basin water transfer is an inadequate water management policy, causing significant unintended side-effects. A comprehensive solution to the problem includes several policy options that simultaneously control the dynamics of the system, minimizing the risk of unintended consequences. In particular, policy makers should consider minimizing agricultural water demand through changing crop patterns as an effective policy solution for the basin\u27s water problems. © 2013 Elsevier B.V
A Survey Of Exemplar Teachers\u27 Perceptions, Use, And Access Of Computer-Based Games And Technology For Classroom Instruction
This study evaluates climate change impacts on crop production and water productivity of four major crops (wheat, barley, rice, and corn) in Iran\u27s Zayandeh-Rud River Basin. Multi-model ensemble scenarios are used to deal with uncertainties in climate change projections for the study period (2015-2044). On average, monthly temperature will increase by 1.1 to 1.5. °C under climate change. Monthly precipitation changes may be positive or negative in different months of the year. Nevertheless, on the annual basis, precipitation will decrease by 11 to 31% with climate change. While warming can potentially shorten the crop growth period, crop production and water productivity of all crops are expected to decrease due to lower precipitation and higher water requirements under higher temperature. Out of the four studied crops, rice and corn are more vulnerable to climate change due to their high irrigation water demand. So, their continued production can be compromised under climate change. This finding is of particular importance, given the locally high economic and food value of these crops in central Iran. © 2012 Elsevier B.V.
Orthopedic effects of splint high-pull headgear â a cephalometric appraisal
Objective: The purpose of this study was to investigate the orthopedic effect of maxillary splint high-pull head gear appliance on maxillary complex.
Design: Retrospective study.
Settings: Patients under treatment in the Department of Orthodontics, Azad University, during one year period from November 2003 to March 2004.
Subjects: Lateral cephalometric radiograph of 26 patients (11 boys and 15 girls, with a mean age of 11.3 years) treated with splint high-pull headgear appliance was compared with a similar control group of 26 individuals (11 boys and 15 girls with a mean age of 12.6 years).
Main outcome measures: The result of the present study showed that the treated group more closely approximated Class I cephalometric values after treatment, whereas the control group with a Class II skeletal pattern did not necessarily become âless Class IIâ due to growth.
Results: Point A was held efficiently in the treated group (SâA = 0.4 mm) whereas in the control group it had relocated downward and forward 2.00 mm along sellaâpoint A (SâA) line. Also, the relocation of the point A in the horizontal (X-axis) and vertical (Y-axis) planes confirmed these findings. No rotational changes of palatal plane were recorded in the treated group. Mandibular skeletal changes were similar to the control group. Maxillary dentition was relocated more posteriorly.
Conclusions: It was concluded that the maxillary splint with high-pull headgear in the present study held the maxilla in position without any rotational changes of the palatal plane. Therefore, a normal skeletal relationship was achieved in the treated group through a combination of maxillary basal bone and dentoalveolar growth inhibition and a normal expression of mandibular growth