61 research outputs found

    Evaluation of Iranian Code No.2800 for Seismic Resistant Design of Near Source Buildings Based on Real Record of Iran

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    In this paper characteristics of near-field earthquakes and difference of ground motion response key parameters in these earthquakes, based on real records of Iran are presented and efficiency of Iranian seismic building code for design of buildings subjected to near-field earthquakes is evaluated. The equivalent static method to calculate the lateral earthquake force exerted on buildings, is common and extensively used. Iranian code of practice for seismic resistant design of buildings, Standard No.2800-05, uses V= (ABI /R)*W relationship to calculate this lateral force. Where A (=design basis acceleration over the bedrock) and B (=the amplification factor) are related to earthquake, and near-field earthquakes may induce dramatically high response in fixed-base building. In this research peak ground acceleration over the bedrock & amplification factor suggested by Iranian Standard No.2800-05 are assessed according to near field earthquake records in Iran and also the results are compared with UBC97 code. The outcomes show the inefficiency of Standard No.2800- 05 for calculating the near source structures. Furthermore, according to this study, a design spectrum is suggested for Iran which it can be used in both near field and far field regions

    Using kriging and co-kriging to predict distributional areas of Kilka species (Clupeonella spp.) in the southern Caspian Sea

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    Understanding ecological and anthropogenic drivers of fish population dynamics and achieving a sustainable yield requires detailed studies on habitat selection and spatial distribution. The objective of this study was to predict spatial density and distribution of kilka species in the southern Caspian sea in relation to satellite-derived sea surface temperature, chlorophyll-a concentration, turbidity and water depths  using ordinary kriging and co-kriging  geostatistical methods and introduction an appropriate potential fishing area according to the present fishing points. Three hundred and fifty fishing surveys were done in two main kilka fishing ports in the southern Caspian Sea (Anzali and Babolsar ports) from 2015 to 2016. The Geostatistical analysis showed that the co-kriging spatial interpolation method provided the best prediction of fish abundance when chlorophyll-a content was included in model

    Evaluating Seismicity Parameters of Sanandaj, Iran Based on Instrumental Earthquakes

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    The main goal of this paper is to evaluate the seismic parameters of Sanandaj, Iran. For this reason, at first, all the occurred instrumental earthquakes (1900-2006) in a radius of 200 km of Sanandaj city have been gathered. After elimination of the aftershocks and foreshocks, the main earthquakes were taken into consideration to calculate the seismic parameters by Gutenberg-Richter method, cumulative distribution functions, and Kijko-Sellevoll approach. This paper aims at estimation of seismicity parameters based on the seismic events and the relation between the cumulative frequency of earthquake occurrence and its magnitude. For this purpose the variable windows in time and location domains are employed, and the earthquakes are supposed to follow Poisson’s formulation. Subsequently, the seismicity coefficients for Gutenberg–Richter, cumulative distribution functions, and Kijko–Sellevoll methods are calculated and the magnitude–period graphs are constructed. These results serve to illustrate the need to carefully reassess the reliability of seismicity parameters using them for seismology, or seismic-hazard purposes

    Modeling some drying characteristics of sour cherry (Prunus cerasus L.) under infrared radiation using mathematical models and artificial neural networks

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    The effect of air temperature, air velocity and infrared (IR) radiation on the drying kinetics of sour cherry was investigated using a laboratory infrared dryer.  Experiments were conducted at air temperatures of 35, 50 and 65°C, air velocities of 0.5, 1.1 and 1.7 m/s and IR radiations of 500, 1,000 and 1,500 W.  Five empirical drying models for describing time dependence of the moisture ratio change were fitted to experimental data.  Artificial neural network (ANN) method was used to predict the effective moisture diffusivity and specific energy consumption of the samples.  Among the applied models, Midilli et al. model was the best to predict the thin layer drying behavior of sour cherry.  Effective moisture diffusivity of sour cherry varied between 1.17×10-10 and 8.13×10-10 m2/s.  Activation energy of sour cherry was in the range of 30.31–     41.68 kJ/mol.  Specific energy consumption was in the range of 56.12–891.16 MJ/kg.  After well training of the ANN models, it proved that the ANN model was relatively better than the empirical models.  The best neural network feed and cascade forward back-propagation topologies for the prediction of effective moisture diffusivity and energy consumption were the 3-2-3-1 and 3-3-3-1 structures with the training algorithm of trainlm and threshold functions of tansig, tansig-logsig-tansig, respectively.  The best R2 value for predication of moisture diffusivity and energy consumption were 0.9944 and 0.9905, respectively.    Keywords: sour cherry, drying, effective moisture diffusivity, activation energy, artificial neural networ

    Uniform Seismic Hazard Spectra of Sanandaj, Iran

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    This paper presents uniform seismic hazard spectra of Sanandaj city of Iran. Sanandaj is the administrative center of Kurdistan province, in which more than 500,000 people live in. A collected catalogue, containing both historical and instrumental events and covering the period from the 10th century BC to the year 2006, is used. Then seismic sources and The seismotectonic model of the considered region have been modeled within the radius of 200 km and recurrence relationship is established. After elimination of the aftershocks and foreshocks, the main earthquakes were taken into consideration to calculate the seismic parameters. For this purpose the method proposed by Kijko [2000] was employed considering uncertainty in magnitude and incomplete earthquake catalogue. Sanandaj and its vicinity has been meshed as an 8(vertical lines)* 10(horizontal lines) and the calculations were performed using Ambraseys and et al. [1996] attenuation relationship. These calculations have been performed by the Poisson distribution of four hazard levels. Seismic hazard assessment is then carried out for each grid point using SEISRISK ΙΙΙ [1987]. The evaluation of the probabilistic occurrence of earthquake for the specific area is shown by horizontal spectral acceleration maps with the probability of 2% and 10% occurrences in 50 years

    Multi-Response Design Optimisation of a Combined Fluidised Bed-Infrared Dryer for Terebinth (Pistacia atlantica L.) Fruit Drying Process Based on Energy and Exergy Assessments by Applying RSM-CCD Modelling

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    The present investigation aimed to perform an optimisation process of the thermodynamic characteristics for terebinth fruit drying under different drying conditions in a fluidised bed-infrared (FBI) dryer using response surface methodology (RSM) based on a central composite design (CCD) approach. The experiments were conducted at three levels of drying air temperature (40, 55, and 70 °C), three levels of drying air velocity (0.93, 1.765, and 2.60 m/s), and three levels of infrared power (500, 1000, and 1500 W). Energy and exergy assessments of the thermodynamic parameters were performed based on the afirst and second laws of thermodynamics. Minimum energy utilisation, energy utilisation ratio, and exergy loss rate, and maximum exergy efficiency, improvement potential rate, and sustainability index were selected as the criteria in the optimisation process. The considered surfaces were evaluated at 20 experimental points. The experimental results were evaluated using a second-order polynomial model where an ANOVA test was applied to identify model ability and optimal operating drying conditions. The results of the ANOVA test showed that all of the operating variables had a highly significant effect on the corresponding responses. At the optimal drying conditions of 40 °C drying air temperature, 2.60 m/s air velocity, 633.54 W infrared power, and desirability of 0.670, the optimised values of energy utilisation, energy utilisation ratio, exergy efficiency, exergy loss rate, improvement potential rate, and sustainability index were 0.036 kJ/s, 0.029, 86.63%, 0.029 kJ/s, 1.79 kJ/s, and 7.36, respectively. The models predicted for all of the responses had R2-values ranging between 0.9254 and 0.9928, which showed that they had good ability to predict these responses. Therefore, the results of this research showed that RSM modelling had acceptable success in optimising thermodynamic performance in addition to achieving the best experimental conditions.info:eu-repo/semantics/publishedVersio

    Prevalence and Correlates of Psychiatric Disorders in a National Survey of Iranian Children and Adolescents

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    Objective: Considering the impact of rapid sociocultural, political, and economical changes on societies and families, population-based surveys of mental disorders in different communities are needed to describe the magnitude of mental health problems and their disabling effects at the individual, familial, and societal levels. Method: A population-based cross sectional survey (IRCAP project) of 30 532 children and adolescents between 6 and 18 years was conducted in all provinces of Iran using a multistage cluster sampling method. Data were collected by 250 clinical psychologists trained to use the validated Persian version of the semi-structured diagnostic interview Kiddie-Schedule for Affective Disorders and Schizophrenia-PL (K-SADS-PL). Results: In this national epidemiological survey, 6209 out of 30 532 (22.31%) were diagnosed with at least one psychiatric disorder. The anxiety disorders (14.13%) and behavioral disorders (8.3%) had the highest prevalence, while eating disorders (0.13%) and psychotic symptoms (0.26%) had the lowest. The prevalence of psychiatric disorders was significantly lower in girls (OR = 0.85; 95% CI: 0.80-0.90), in those living in the rural area (OR = 0.80; 95% CI: 0.73-0.87), in those aged 15-18 years (OR = 0.92; 95% CI: 0.86-0.99), as well as that was significantly higher in those who had a parent suffering from mental disorders (OR = 1.96; 95% CI: 1.63-2.36 for mother and OR = 1.33; 95% CI: 1.07-1.66 for father) or physical illness (OR = 1.26; 95% CI: 1.17-1.35 for mother and OR = 1.19; 95% CI: 1.10-1.28 for father). Conclusion: About one fifth of Iranian children and adolescents suffer from at least one psychiatric disorder. Therefore, we should give a greater priority to promoting mental health and public health, provide more accessible services and trainings, and reduce barriers to accessing existing services

    Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021

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    Background: Estimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period. Methods: 22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30 763 location-years of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In location-years where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution. Findings: Global all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations. Interpretation: Global adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic

    Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

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    BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed
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