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1.
PLoS One ; 18(5): e0285457, 2023.
Article in English | MEDLINE | ID: mdl-37228118

ABSTRACT

Sports tours are a key category of tourism with special interest whose evolution and development are influenced by a variety of limiters and facilitators. Research literature recommends exploring these factors. Therefore, our goal was to present a grounded theory about the development of sports tours in Iran's tourism industry. For this purpose, we considered Glaser's approach and conducted 15 interviews with experts in the field of tourism and sports tours who worked under the supervision of the Ministry of Tourism and Cultural Heritage of Iran. The data were analyzed using the Glaser's approach principles. The developed theory from this study showed that the development of sports tours is an structure that stops moving under the influence of inhibitors such as financial, political, security, structural, and organizational issues, and travels the path of perfection and progress through facilitators such as natural attractions, the role of the media, the role of tour guides, the quality of services, information technology, support, culture, and training, and the human force. Based on this result, it can be said that the development and evolution of sports tours in Iran are influenced by various determinants, and it is important to remove the limiting factors and strengthen the factors that play a facilitating role in the development of sports tours.


Subject(s)
Sports , Tourism , Humans , Industry , Travel , Information Science
2.
Heliyon ; 8(2): e08768, 2022 Feb.
Article in English | MEDLINE | ID: mdl-35198748

ABSTRACT

Robust flow measurement in multi-phase systems has extensive applications in understanding, design, and operation of complex environmental, energy and industrial processes. The nonlinearity and spatiotemporal variability of the interactions between different flow phases makes the multi-phase flow measurement a challenging task. Two Sliding Mode Observer (SMO) schemes are proposed in this study for the state estimation of a decentralized multi-phase flow measurement system. The developed observers are shown to be theoretically valid and numerically applicable for a real-life case study data. The multi-phase flow system considered in this paper can be described as two interconnected sub-systems including fluid and gas sub-systems, and two scenarios are considered in the design of the observers. The first scenario considers the interconnections as bounded disturbance (SMOD), while the second scenario considers the interconnections as an uncertainty (SMOU). Hence, the Sliding Mode Observers are adopted to mitigate the effects of disturbance in the system and uncertainties in the parameters. Numerical simulations are conducted using MATLAB and dynamic HYSYS simultaneously, using the data obtained from field-based multi-phase flow measurements. The results demonstrate the appropriateness and robustness of the proposed Sliding Mode Observer (SMO) for estimation of the multi-phase fluid specifications including the density, velocity, and the volume phases fraction in each subsystem. The analysis of the results highlights that the proposed model is computationally efficient with fast transient response, accurate tracking capability of the real process data, and very low steady-state error. This study shows that choosing an appropriate Lyapunov-Krasovsky function results in the asymptotic stability of the decentralized system and improves the performance of the proposed observers. Uncertainty analysis is conducted on the velocity estimation results obtained from the Sliding Observers. Overall, SMOU method shown better performance with RMSE of 0.24%, while RMSE of 0.46% was achieved for the SMOD. Comparison of the numerical results with the field-based flow measurement, as a benchmark, shows that although uncertainty in SMOU is approximately half of the uncertainty in SMOD, state estimation for both schemes was achieved in a finite time with high order of precision. It was shown that both observers developed in this study are well capable of estimating the multi-phase flow variables and states.

3.
Heliyon ; 6(1): e03193, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31993517

ABSTRACT

This paper presents a new computational method for the decentralized multiphase flow measurement based on the interconnections between the two subsystems to precisely estimate the states of the multiphase flow at the gas refinery. The states of the condensate and gas sub-systems were separately estimated using the Differential Mean Value Theorem by considering the relationship between two subsystems, designing an observer and converting the conditions to linear matrix inequality. To check the stability and performance of the system against the changes, the Lyapunov theory has been used. The states behavior investigated with and without disturbance in the system output and dynamics. Additionally, the Unscented Kalman Filter based on the simplified drift flux model was used to estimate the states. It is found that both observers are capable to identify the states with some differences in performance and drift flux model is sufficient for estimation of parameters and states.

4.
J Sep Sci ; 42(8): 1620-1628, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30758140

ABSTRACT

In the present study, a supramolecular solvent was formed from reverse micelle aggregates of octanol. The proposed supramolecular solvent was used for rapid extraction of some antidepressants drugs including amitriptyline, imipramine, desipramine, maprotiline, sertraline, and doxepin from biological samples. Alkanol-based supramolecular solvents have a unique array of physicochemical properties, making them a very attractive alternative to replace organic solvents in analytical extractions. The parameters affecting the extraction of target analytes (i.e., the volume of tetrahydrofuran and octanol as the major components comprising the supramolecular solvent, chain length of alkanols, sample solution pH, salt addition, and ultrasonic time) were investigated and optimized by factor by factor optimization method. Under the optimum conditions, preconcentration factors of 470, 490, 460, 385, 370, and 430 were obtained for amitriptyline, doxepin, imipramine, desipramine, maprotiline, and sertraline, respectively. The linear ranges and coefficients of determination (R2 ) were obtained in the range of 0.01-100 µg/L and 0.9974-0.9991, respectively. Also the limits of detection (S/N = 3) of 0.003-0.03 µg/L, and precisions (n = 5) of 4.9-8.9% were calculated. Finally, the method was successfully applied for the extraction of antidepressant drugs in biological samples, and relative recoveries in the range of 91-102% were obtained.


Subject(s)
Antidepressive Agents/isolation & purification , Gas Chromatography-Mass Spectrometry/methods , Liquid Phase Microextraction/methods , Ultrasonics/methods , Antidepressive Agents/blood , Antidepressive Agents/urine , Furans/chemistry , Humans , Limit of Detection , Octanols/chemistry , Solvents/chemistry
5.
Turk J Orthod ; 32(4): 200-206, 2019 Dec.
Article in English | MEDLINE | ID: mdl-32110464

ABSTRACT

OBJECTIVE: The purpose of the present study was to determine the facial anatomical landmarks, in order of accuracy, closest to the midline of the face, as well as oral cavity midline, and to specify which intraoral anatomical landmarks are closer to the dental midline. METHODS: Three commonly used anatomical landmarks including nasion, nose, and philtrum tips were marked clinically in 108 subjects. A frontal full-face digital image was used for midline analysis in accordance with the esthetic frame. Deviations from the facial and oral midlines were measured for the three clinical landmarks. Dental midline was considered as the fourth landmark. Alginate impressions were taken, and casts were analyzed under standardized conditions. The labial frenum and incisive papilla were marked. Cast images were taken and analyzed. RESULTS: Data showed difference between the mean ratios of the selected anatomical landmarks and the facial and oral midlines (p≤0/05). The anatomical landmark hierarchies, in proximity to the facial midline, are commissural midlines, nasion, philtrum tip, nose tip, and dental midline, respectively. The anatomical landmark hierarchies, in proximity to the commissural midline, include dental midline, philtrum tip, nose tip, and nasion. The labial frenum was less deviated from the dental midline than the incisive papilla. CONCLUSION: With respect to shortcomings, the results showed that all of the anatomical landmarks were deviated from the facial and oral midlines. The order of proximity of the anatomical landmarks to the facial midline was as follows: commissural midline, nasion, philtrum, and dental midline.

6.
Psychiatry Res ; 261: 40-44, 2018 03.
Article in English | MEDLINE | ID: mdl-29276993

ABSTRACT

Attention deficit hyperactivity disorder (ADHD) is a chronic condition with frequent comorbidities such as obesity, troubled relationships, low self-esteem, and difficulty in motor proficiency. This study aims to elucidate the effect of high-intensity intermittent training on motor proficiency, adiponectin, and insulin resistance in adolescent students with ADHD disorder. Fifty adolescent students of both genders with ADHD diagnosis participated and assigned into four experimental groups (each group with 15 girls and 10 boys students; two experimental and two control groups). High-intensity intermittent training was performed continuously 3 times a week for 6 weeks in experimental groups. Serum adiponectin level significantly increased in the experimental groups of both genders after 6 weeks intermittent training while insulin resistance levels were markedly decreased. Furthermore, motor proficiency score were significantly improved in the experimental groups of both genders. In addition gender had no significant impact on adiponectin, insulin resistance and motor proficiency rating. The findings of this study suggest that high intensity intermittent training improved physiological systems in ADHD population that leads to reduce risk factors for future development of comorbidities.


Subject(s)
Adiponectin/blood , Attention Deficit Disorder with Hyperactivity/blood , Attention Deficit Disorder with Hyperactivity/psychology , High-Intensity Interval Training/psychology , Motor Skills/physiology , Students/psychology , Adolescent , Adolescent Behavior , Attention Deficit Disorder with Hyperactivity/therapy , Biomarkers/blood , Child , Comorbidity , Female , High-Intensity Interval Training/methods , High-Intensity Interval Training/trends , Humans , Insulin Resistance/physiology , Male
7.
J Hazard Mater ; 184(1-3): 869-871, 2010 Dec 15.
Article in English | MEDLINE | ID: mdl-20832939

ABSTRACT

A simple, rapid and environmentally friendly analytical methodology is developed for extraction of pesticides (diazinon, chlorpyrifos and trifluralin) from sediment samples based on a technique called low density miniaturized homogenous liquid-liquid extraction (LDMHLLE) prior gas chromatography mass spectrometry determination. The method based on homogeneous liquid-liquid extraction with methanol containing n-hexane as a solvent of lower density than water (n-hexane). After addition of water, n-hexane solvent immediately forms a distinct water immiscible phase at the top of the vial, which can be easily separated and injected to the GC/MS instrument for quantification. Acquisition was performed in the selected ion monitoring mode. The limits of detection were estimated for the individual pesticides as 3S(b) (three times of the standard deviation of baseline) of the measured chromatogram for pesticides. The proposed method is very fast, simple, and sensitive without any need for stirring and centrifugation and applied to real sediment samples, successfully.


Subject(s)
Chromatography, Liquid/methods , Gas Chromatography-Mass Spectrometry/methods , Geologic Sediments/analysis , Pesticide Residues/analysis , Hexanes/chemistry , Limit of Detection , Solvents/chemistry
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