147 research outputs found
Ecotourism supply chain during the COVID-19 pandemic: A real case study
The coronavirus (COVID-19) disease has caused serious and irreversible damage to the ecotourism industry, posing serious challenges to all parts of the ecotourism supply chain. The ecotourism supply chain is made up of various components, the most important of which are ecotourism centers. During these pandemic times, the primary concerns of these centers are to improve their deplorable economic conditions and retain customers for the post-coronavirus era. As a result, an investigation should be conducted to address these concerns and provide appropriate solutions to help them overcome the challenges that have emerged. To achieve the research goal, a bi-objective mathematical model for the ecotourism supply chain in an uncertain environment is developed, accounting for the effects of COVID-19. The first objective function minimizes the total cost of the supply chain, while the second maximizes customer satisfaction. The proposed mathematical model is solved using a fuzzy goal programming (FGP) method. A sensitivity analysis study is also carried out to examine the performance of some basic parameters. Furthermore, the model is tested in a real case study to determine its efficacy. Finally, some effective managerial insights are proposed to improve the situation of the centers during the pandemic. © 2021 The Author
Genetic Algorithm Based Optimization of Space Vector Modulation Employed in STATCOM to Reduce Harmonics in Power System
Abstract: Existing of nonlinear loads and harmonic generation in electric power systems makes it prevalent to use harmonic filters. STATCOM plays an important role in eliminating harmonics and fixing the voltage using power electronics switches. Various control methods have been introduced for switching in a STATCOM. In this paper the Space Vector Modulation (SVM) is described and it is optimized by Genetic Algorithm (GA) to reduce the harmonic contents. At last, some simulations of power system with STATCOM have been done in MATLAB to prove the efficiency of the proposed switching method employed in a STATCOM. Results including voltage weighted THD show the proper performance of STATCOM using optimized SVM by GA
Vitamin D status of 6- to 7-year-old children living in Isfahan, Iran
Wstęp: Witamina D ma podstawowe znaczenie dla utrzymania dobrego zdrowia. O niedoborach witaminy D donoszą autorzy z wielu
krajów, również tych o dużym stopniu nasłonecznienia. Niniejsze badanie przeprowadzono w celu dokonania oceny stężenia witaminy
D u zdrowych dzieci w wieku 6-7 lat, zamieszkałych w Isfahanie, Iran.
Materiał i metody: Do badania włączono 513 zdrowych dzieci. Zmierzono u nich stężenie PTH i 25-hydroksywitaminy D (25-OHD)
w surowicy. Określono spożycie witaminy D w diecie, czas ekspozycji na słońce w ciągu doby i odsetek powierzchni ciała wystawionej na
działanie słońca. Przyjęto, że stężenia 25-OHD wynoszące < 20 ng/ml i 10 ng/ml odpowiadają odpowiednio łagodnemu i ciężkiemu
niedoborowi witaminy D. Do ustalenia lokalnych punktów odcięcia dla niedoborów witaminy D użyto krzywych ROC.
Wyniki: U 3% dzieci stężenie witaminy 25-OHD wynosiło < 20 ng/ml, a u 26% wynosiło < 33 ng/ml (lokalny punkt odcięcia dla niedoboru
witaminy D). Czas ekspozycji na słońce i dzienne spożycie witaminy D w diecie miały istotny wpływ na stężenie witaminy D
w surowicy.
Wnioski: W omawianym badaniu wykazano częste występowanie niedoboru witaminy D u dzieci zamieszkałych w Isfahanie. Wydłużenie
czasu ekspozycji na słońce i zwiększenie dziennego spożycia witaminy D w diecie może zapobiec niedoborom witaminy D u tych dzieci.
(Endokrynol Pol 2010; 61 (4): 377-382)Introduction: Vitamin D is essential for the maintenance of good health, and vitamin D deficiency has been reported from many countries,
including those with a lot of sunshine. This study was conducted to evaluate the vitamin D status in healthy 6- to 7-year-old children
in Isfahan, Iran.
Material and methods: Five hundred and thirteen healthy children were enrolled. Serum PTH and 25-hydroxyvitamin D (25-OHD) were
measured. Dietary vitamin D intake, duration of daily sunlight exposure, and percentage of exposed body surface area were determined.
25-OHD levels < 20 ng/mL and < 10 ng/mL were defined as mild and severe vitamin D deficiency, respectively. The ROC curve was
utilized to obtain a local cut-off point of vitamin D deficiency.
Results: 25-OHD was < 20 ng/mL in 3% and < 33 ng/mL (local cut-off point of vitamin D deficiency) in 26% of subjects. Duration of
sunlight exposure and daily intake of vitamin D had significant effects on serum level of vitamin D.
Conclusions: A high prevalence of vitamin D deficiency in Isfahan children was observed in this study. Improvements in duration of
sunlight exposure and daily intake of vitamin D can prevent vitamin D deficiency in these children.
(Pol J Endocrinol 2010; 61 (4): 377-382
A Comparative Study of Liability Resulting from Future Loss in Jurisprudence and Law of Iran with France
Undoubtedly, the purpose of establishing the rules of civil liability is to compensate for the loss. In other words and from a technical point of view, a loss must be caused to compensate for it, responsibility should be created, and religion should be responsible. In fact, the occurrence and survival of civil liability depend on the current existence of damage, and quantity and quality are not involved in the principle of liability. In other words, the rule governing civil liability is the rule of all or nothing. That is, the responsibility is considered to exist when the loss is realized, and to be extinguished when it is not. Meanwhile, taking into account one of the conditions of claimable loss, which must be certain in the past and that one cannot be sentenced to compensation based on the mere possibility of loss, this research seeks to find an answer to this question: Considering Iran’s and France’s laws and regulations and through the prevention of civil liability, it is possible to imagine a place for future loss and the possibility of compensation? The findings of this research indicate that a possible loss is a loss that has the possibility of its realization in the future, but a future loss is a loss whose existence and realization in the future are certain and the necessity of its existence has been achieved in such a way that a country’s custom and law consider such losses to be definitely claimable
An evaluation of hospital admission respiratory disease attributed to sulfur dioxide ambient concentration in Ahvaz from 2011 through 2013
There is no doubt that air pollutants have adverse
impacts on human health. The main objective of this study
was to evaluate hospital admission respiratory disease
(HARD) attributed to sulfur dioxide levels in Ahvaz during
three successive years. Data was taken from Iranian
Environmental Protection Agency (EPA). The AirQ2,2,3
model is used to quantify the impact of SO2 on inhabitants
of Ahvaz and in terms of hospital admission respiratory diseases.
This is a kind of statistical model which is based on
some epidemiological indices such as relative risk, baseline
incidence, and attributable proportion. Sampling was already
performed for 24 h in four stations during 2011–2013. Four
stations are good representative for residential, high traffic,
industry, and background sites which cover the whole area
of the Ahvaz city. Regarding to gravimetric scale, raw data
of sulfur dioxide was processed using Excel software.
Encoding, filtering, and processing were conducted to prepare
input file for the Air Q2,2,3 model. After running model,1 Air Pollution and Respiratory Diseases Research Center, Ahvaz
Jundishapur University of Medical Sciences, Ahvaz, Iran
2 Environmental Technologies Research Center, Ahvaz Jundishapur
University of Medical Sciences, Ahvaz, Iran
3 Islamic Azad University, Tehran Medical Sciences Branch,
Tehran, Iran
4 Razi Teaching Hospital, Clinical Research Development Center,
Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
5 Department of Internal Medicine, Division of Pulmonology, Imam
Khomeini Hospital, Ahvaz Jundishapur University of Medical
Sciences, Ahvaz, Iran
6 Nutrition&Metabolic Diseases Research Center, Ahvaz Jundishapur
University of Medical Sciences, Ahvaz, Iran
7 Social Determinants of Health Research Center, Yasuj University of
Medical Sciences, Yasuj, Iran
8 Research Center for Environmental Pollutants, Qom University of
Medical Sciences, Qom, Iran
9 Department of Environmental Health Engineering, Faculty of Health,
Bushehr University of Medical Sciences, Bushehr, Iran
10 The Persian Gulf Marine Biotechnology Research Center, The
Persian Gulf Research Center, Bushehr University of Medical
Sciences, Bushehr, Iran
11 Hyperlipidemia Research Center, Department of Laboratory
Sciences School of Paramedical Sciences, Ahvaz Jundishapur
University of Medical Sciences, Ahvaz, IR, Iran
12 Environmental Research Institute, Academic Center for Education,
Culture and Research (ACECR), Rasht, Iran
13 Department of Anaesthesiology, Faculty of Medicine, Ahvaz
Jundishapur University of Medical Sciences, Ahvaz, Iran
14 Occupational Hazards Control Research Center and Department of
Environmental Health Engineering, School of Public Health
Environmental, Shahid Beheshti University of Medical Sciences,
Tehran, Iran
15 Faculty of Food Science & Technology, Tehran University,
Tehran, Iran
16 Student Research Committee, Department of Environmental Health
Engineering, Ahvaz Jundishapur University of Medical Sciences,
Ahvaz, Iran
Environ Sci Pollut Res
DOI 10.1007/s11356-016-7447-xoutputs presented in term of hospital admissions respiratory
cases. Based on our result, the highest mean and maximum of
seasonal and annual levels for sulfur dioxide were observed in
2013. We concluded that obnoxious quality of fuel and some
deficiencies in maintenance and operation of industries lead to
worse quality of ambient air especially in 2013. Cumulative
cases of HARD attributed to sulfur dioxide level at central of
relative risk (RR) were estimated 24, 25, and 30 persons for
2011, 2012, and 2013, respectively. The finding of this study
showed that total mean of sulfur dioxide was higher than
standard concentration. We also noticed that wintertime concentrations
of sulfur dioxide during three successive years
were higher than of those levels in summer
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