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متن کامل


اطلاعات دوره: 
  • سال: 

    1402
  • دوره: 

    11
  • شماره: 

    2
  • صفحات: 

    61-74
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    186
  • دانلود: 

    27
چکیده: 

ABSTRACTDuring the last century, ports of Persian Gulf become the most important storage, refining and transportation of crude oil, oil derivation, petrochemical products and also, business activities. Nowadays, due to functional diversity between ports, the impact of port activities on the development of urban spaces will be different, and this issue leads to structural differences of port cities. The purpose of this research is to identify the key variables affecting the relations and spatial structure of port-city in Dubai as the most thriving and successful port-city in the Persian Gulf. This research is based on deductive reasoning and carried out by analysis of cross effects with secondary data (results of other prominent articles) and also primary data (questionnaire). sampling method is based on purposive sampling and Micmac software was used to analyze the data. Output of Micmac software shows the position of the instability of the system. Therefore, the position of each variables in the conceptual model can be categorized to driver, linkage, dependent, and autonomous factors. The research findings indicate 4 variables (like as “income, cost and investmnets in port-city”) can be introduced as a driver factor, 5 variables (like as “advanced multimodal transportation in the port”) can be introduced as a linkage factor, 6 variables (like as “quality of living environment and desirable city”) can be introduced as a dependent factor, 3 variables (like as “environmental protection and sustainable development of the city-port”) can be introduced as an autonomous factor. The rapid development of Dubai can be explained by the purposeful distribution of revenues from trade and tourismExtended AbstractIntroductionDuring the last century, ports of Persian Gulf become the most important storage, refining and transportation of crude oil, oil derivation, petrochemical products and also, business activities. The global increase in oil demand since the 1950s led to the creation of discovery of new oil wells and large industrial areas. With the construction of new oil or gas facilities in the port areas, increasing oil revenues contributed to the countries of the Persian Gulf region and form a new geographical relationship between ports and coastal cities which had an impact on the spatial structure and relation of them. Nowadays, due to functional diversity between ports, the impact of port activities on the development of urban spaces will be different, and this issue leads to structural differences of port cities. In the 1950s, Containerization (container loading technology) was based in some of the world's ports and created a huge transformation in the shipping industry, which had a significant impact on the development of ports. Although the ports of the Persian Gulf have made a significant contribution to the economic growth and physical development of other ports in the world, but few researches have been done on the variables and factors affecting the development of the spatial structure of the important ports of the Persian Gulf. This region, due to its unique geographical location, has always been considered as a most important corridor in the field of economic and transportation throughout history. Some of the most important energy and commercial ports in this region are: Dubai, Manama, Kuwait, Dammam, Doha, Bushehr, Bandar-Abbas and Assaluyeh. In this regard, the purpose of this research is to identify the key variables affecting the relations and spatial structure of port-city in Dubai as the most thriving and successful port-city in the Persian Gulf. MethodologyThis research is based on deductive reasoning and carried out by analysis of cross effects with secondary data (results of other prominent articles) and also primary data (questionnaire). The method used in this research is quantitative and the sampling method is based on purposive sampling. the variables affecting the spatial structure of port-city relations were identified in the form of a review of 31 prominent articles. 25 experts (who had comprehensive knowledge and information about the development process of the city-port of Dubai) participated to determine the effectiveness or influence of variables. Finally, the output of data analysis was done by the Micmac software. Results and discussionOutput of Micmac software shows the position of the variables in the diagram that it indicates their status in the system and their role in the dynamics and changes of the system. The method of distribution and dispersion of the variables in the spatial structure of port-city relations indicates the instability of the system. Therefore, based on the output of the system, the position of each variables in the conceptual model can be identified in five categories (driver, linkage, dependent, autonomous and regulatory variables). According to the results, some variables such as “the changes in the strategic positions” and “geopolitics of port-city”, “the modification of the management method” and “regional planning of the ports”, “the promotion of local governance in the relations between port-city” and “the way of national and international management of ports have been introduced as driver variables. On the other hand, five variables consist of “advanced multimodal transportation in the port” and “income, cost and investment in the port-city”, “the contrast and physical integration of the port - city space”, “the development of various industrial and production activities in the ports and their local hinterland” and “their qualities Financial and commercial policies of ports” have been introduced as linkage variables. Findings of research also shows that some variables consist of “quality of living environment and desirable city”, “quantity and quality of transit corridors (rail, road and air) to hinterland”, “construction and launching the new port (sea port or dry port)”, “terminal facilities and infrastructure and warehousing”, “conflict or convergence between the city and the port” and “increase in population growth rate and migration to the port - city” categorized as dependent variables. Three variables including “cultural and historical background of ports”, “use of cheaper energy, Less-polluted, clean and renewable energies in the city-port” and “environmental protection and sustainable development of the city-port” categorized as autonomous variables. Finally, a variable with the title of “improvement in management and information technology and development in loading, unloading and storage of commodities” have been introduced as regulatory variables. The findings of this research have a remarkable similarity with other researches carried out in the field of city-port relation and clearly emphasize the direct impact of the "investment in port-city" in the development of them. For example, Grossmann (2008) emphasized that city-port of Hamburg has become one of the largest ports in Northern Europe during the last few decades due to huge domestic and foreign investment. ConclusionThis research carried out in order to introduce and explain the key variables affecting the development of the spatial structure of the port-city of Dubai. On this basis, 21 variables have been extracted by systematic reviews of prominent articles. In the following, 25 experts were selected with the purposive sampling method. Among the 21 variables extracted, 4 variables (like as “geopolitics of port-city”) introduced as a driver factor, 5 variables (like as “advanced multimodal transportation in the port”) introduced as a linkage factor, 6 variables (like as “quality of living environment and desirable city”) introduced as a dependent factor, 3 variables (like as “environmental protection and sustainable development of the city-port”) introduced as an autonomous factor. The rapid development of Dubai can be explained by the purposeful distribution of revenues from trade and tourism. A part of these revenues has been directed towards investment in important transportation infrastructures such as airports and ports of this city. These strategies have a wide impact on improving the economic growth of the city and the development of the port in order to adapt with the global trade and advanced technologies. FundingThere is no funding support. Authors’ ContributionAuthors contributed equally to the conceptualization and writing of the article. All of the authors approved the content of the manuscript and agreed on all aspects of the work declaration of competing interest none. Conflict of InterestAuthors declared no conflict of interest. Acknowledgments We are grateful to all the scientific consultants of this paper.

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نویسندگان: 

FERGUSSON D.B. | PRICE D.A. | WALLACE S.

اطلاعات دوره: 
  • سال: 

    1980
  • دوره: 

    28
  • شماره: 

    -
  • صفحات: 

    301-313
تعامل: 
  • استنادات: 

    1
  • بازدید: 

    121
  • دانلود: 

    0
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نویسندگان: 

Balasekaran Govindasamy | Thompson Sarah | Govindaswamy Visvasuresh Victor | Ng Yew Cheo

اطلاعات دوره: 
  • سال: 

    2022
  • دوره: 

    14
  • شماره: 

    1
  • صفحات: 

    115-140
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    31
  • دانلود: 

    0
چکیده: 

Background: High altitude environments can cause a range of physiological changes in the body, and adolescents may be particularly vulnerable to the effects of altitude sickness. Acetazolamide has been shown to be an effective treatment for altitude sickness, but further research is needed to determine its impact on physiological variables among adolescents at high altitude. Aim: The aim of this study was to investigate the effects of acetazolamide in adolescents over 17 days at high altitude. Materials and Methods: Twenty-five healthy adolescents volunteered for this study and were randomly separated into control group (CG, n=12) and acetazolamide group (AG, n=13). AG took 250mg of acetazolamide. Resting Heart Rate (RHR) and Acute Mountain Sickness (AMS) using the Lake Louise questionnaire were measured each morning and afternoon during field testing, Resting Blood Pressure (RBP) was measured each afternoon. Pre-and post-blood samples (haemoglobin (Hb) and haematocrit (Hct)) were taken at sea level (SL) one week before departure and within 40 hours on return to SL. Results: Significant differences between groups for RHR on days 2, 3 and 5, systolic blood pressures for day 4 and 13 (P<0. 05). No significant difference between groups for diastolic blood pressure, pre-and post-altitude for Hb, Hct and PV. AMS scores did not differ from the two groups except on morning of day 12 (P<0. 05). Discussion and Conclusion: Results revealed that acetazolamide did not significantly induce changes to adolescents’ AMS scores and physiological changes. However, adolescents may consume acetazolamide to achieve lower RHR that may enable them to accommodate to HA, prolonging exercise in similar environments.

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نویسندگان: 

MORRIS D.M. | BELONI R.K. | WHEELER H.E.

اطلاعات دوره: 
  • سال: 

    2013
  • دوره: 

    38
  • شماره: 

    -
  • صفحات: 

    363-367
تعامل: 
  • استنادات: 

    1
  • بازدید: 

    108
  • دانلود: 

    0
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چکیده: 

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نشریه: 

المپیک

اطلاعات دوره: 
  • سال: 

    1388
  • دوره: 

    17
  • شماره: 

    4 (پیاپی 48)
  • صفحات: 

    41-53
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    2377
  • دانلود: 

    914
چکیده: 

هدف این تحقیق عبارت است از سنجش روایی متغیرهای فیزیولوژیکی آزمون بی هوازی دوی سرعت (RAST) با توجه به آزمون وینگیت. 25 بازیکن تیم ملی فوتسال مردان با سن 23.21±3.24 سال، 23.35±1BMI کیلوگرم بر مترمربع، و چربی بدن 12.93±1.84 درصد آزمون های وینگیت 30 ثانیه و RAST را برای برآورد شاخص های توان بی هوازی (اوج، حداقل، میانگین توان بی هوازی، و شاخص خستگی) به فاصله چهار روز از یکدیگر اجرا کردند. همچنین، تغییرات ضربان قلب و لاکتات خون بلافاصله، 30 ثانیه، و 2 دقیقه پس از دو آزمون با ضربان سنج پولار و دشتگاه لاکتومتر تعیین شد. روایی هم زمان متغیرهای آزمون RAST در برابر آزمون وینگیت با استفاده از آزمون های ضریب همبستگی پیرسون و t استیودنت در گروه های هم بسته تعیین شد. یافته های تحقیق نشان داد بین حداکثر، حداقل، و میانگین توان بی هوازی دو آزمون همبستگی متوسط و معناداری وجود دارد (p<0.01 r=0.49,p<0.01 r=0.52,p<0.01 r=0.5) ولی بین شاخص خستگی دو آزمون همبستگی معناداری مشاهده نشد (r=0.15). میزان لاکتات خون بلافاصله، 30 ثانیه، و 2 دقیقه (r=0.12,r=0.08,r=0.16) همچنین ضربان قلب بلافاصله و 30 ثانیه پس از دو آزمون همبستگی معناداری نداشتند (r=0.22,r=0.35). اما ضربان قلب 2دقیقه پس از دو آزمون همبستگی معناداری داشتند (p<0.01 r=0.39). هرچند اختلاف معناداری بین شاخص های اوج، حداقل، و میانیگن توان بی هوازی، شاخص خستگی، و ضربان قلب بلافاصله و 30 ثانیه پس از دو آزمون مشاهده شد (p<0.05)، اما عدم وجود اختلاف معنادار بین لاکتات خون زمان های منتخب پس از دو ازمون نشان دهنده میزان فشار فیزیولوژیکی تقریبا مشابه در این دو آزمون است. با توجه به یافته های تحقیق می توان از آزمون RAST نیز که ویژگی بیشتری با رشته فوتسال دارد، برای تمرن و برآورد توان بی هوازی بازیکنان فوتسال استفاده کرد اما با توجه به تفاوت های موجود نمی توان کاملا آن را جایگزین آزمون وینگیت کرد.

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اطلاعات دوره: 
  • سال: 

    1389
  • دوره: 

    1
  • شماره: 

    4
  • صفحات: 

    55-69
تعامل: 
  • استنادات: 

    1
  • بازدید: 

    1000
  • دانلود: 

    243
چکیده: 

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اطلاعات دوره: 
  • سال: 

    1403
  • دوره: 

    16
  • شماره: 

    4
  • صفحات: 

    91-106
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    18
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    0
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مقدمه: مدّت کوتاه مرحلۀ حفظ آمادگی در عراق منجر به عدم آمادگی بازیکنان برای مسابقات می شود. هدف از این پژوهش، بررسی تأثیر تمرین های ویژه و مکمّل C4 در مرحلۀ حفظ آمادگی بر VO2max، لاکتات، استقامت در سرعت، چابکی و سرعت بازیکنان مرد فوتسال لیگ برتر عراق بود.روش پژوهش: تحقیق نیمه تجربی و با اندازه گیری در سه مرحلۀ پیش آزمون و دو پس آزمون پس از سه و شش هفته بود. 45 بازیکن فوتسال از باشگاه های مختلف لیگ برتر عراق به سه گروه 15 نفره تقسیم شدند. به گروه آزمایش اوّل (EX1)، برنامۀ تمرینی ویژه و مکمّل C4 به مدّت شش هفته و به گروه آزمایش دوّم (EX2) فقط یک برنامۀ تمرینی ویژه و یک دارونما به مدّت شش هفته داده شد. گروه کنترل (CON) برنامۀ تمرینی باشگاه خود را ادامه دادند. یافته ها: نتایج Mixed model ANOVA در تمامی متغیّرها (VO2max، لاکتات، استقامت سرعت، سرعت و چابکی) بعد از سه هفته و شش هفته در گروه های EX1 و EX2 تفاوت معنا داری نشان داد (05/0 >P ). درحالی که از نظر آماری تفاوت معناداری در گروه CON مشاهده نشد (05/0 نتیجه گیری: تمرین های ویژه طراحی شده در این پژوهش می تواند بر فاکتورهای آمادگی جسمانی در این مطالعه تاثیر مثبت داشته باشد و به عنوان طراحی تمرین خاص در فصل قبل از مسابقات پیشنهاد شود ؛ اما مکمّل یاری C4 تأثیری بر متغیّرهای مورد مطالعه در این فصل از تمرین نداشت.

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نویسندگان: 

اطلاعات دوره: 
  • سال: 

    2018
  • دوره: 

    15
  • شماره: 

    1
  • صفحات: 

    11-17
تعامل: 
  • استنادات: 

    1
  • بازدید: 

    78
  • دانلود: 

    0
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اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    2
  • شماره: 

    2-4 (11)
  • صفحات: 

    79-85
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    321
  • دانلود: 

    0
چکیده: 

IntroductionDaily rhythm as one of the biological rhythms with a period of about 24 hours on various body systems and physiological responses affect on them. Body temperature is a fundamental variable as one of the specifications used daily rhythms The main purpose of this study was evaluating the effect of circadian rhythms on exercise performing and physiological variants of security system in swimmers.Materials and MethodsIn one study, before and after the 12 men swimmers in the league, of Fars Province with an average age of 19.80+1.87 years, had been invited, and after explaining the situation and also completed a written consent form purposefully participated in the study. To measure the length of 400m and 50 meters breast stroke timer QQ model CR2032 (China) was used. The one-way analysis of variance (ANOVA) was used to this study.ResultResults showed body temperature significantly increased from 6:00 to 18:00. Circadian rhythms significantly showed increase from 6 to 18 (P<0.05); circadian rhythms significantly showed effect on performing record in 400m and 50m chest crawl swimming with decrease of influence in 18:00 rather than 6:00; also circadian rhythms significantly showed influence on Immunoglobulin A (IgA) in resting after 400m and after 50m swimming with increasing from morning to evening (P<0.05). But in Immunoglobulin G (IgG) not significant increase in 6:00 until 18:00 in three conditions. The effects of activities in IgA in 6:00 showed decrease after 400m swimming and increasing after 50m, and in 18:00 increasing after 400m and 50m, but not significant activity in 6:00 showed significantly increase effects in IgG after 400m and 50m swimming and not significant decrease in 18:00 the received (P>0.05).ConclusionIn this study, the body temperature exercise performance and IgA variant of security system, were influenced by circadian rhythms and kinds of practicing programs in 18:00 change IgG. So in the time of measuring body temperature exercise performance and variants of salivary of security system must be pied attention to influence of cicardian rhythms.

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اطلاعات دوره: 
  • سال: 

    1397
  • دوره: 

    8
  • شماره: 

    1
  • صفحات: 

    57-73
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    519
  • دانلود: 

    0
چکیده: 

این تحقیق به منظور بررسی اثر تنش خشکی بر عملکرد و برخی خصوصیات فیزیولوژیک ارقام گندم انجام پذیرفت. شش رقم مورد مطالعه در شرایط گلخانه و مزرعه تحت تنش خشکی رشد یافتند. نمونه های برگی برای اندازه گیری خصوصیات فیزیولوژیک از قبیل طول روزنه سطوح بالایی و زیرین برگ، محتوی نسبی آب، سرعت تعرق، نشت یون، پایداری غشای کلروفیل و فلورسانس کلروفیل از گیاهان رشد یافته در شرایط گلخانه گرفته شدند. عملکرد دانه از گیاهان رشد یافته در شرایط مزرعه اندازه گیری گردید. نتایج نشان داد که تنش خشکی اثرات معنی داری بر صفات اندازه گیری شده داشت. بین ارقام گندم نیز از نظر اکثر صفات مورد نظر اختلاف معنی دار به دست آمد. تنش خشکی باعث افزایش F0 و کاهش Fm شد. همچنین تنش خشکی سبب کاهش عملکرد دانه گردید به طوری که بالاترین عملکرد از شرایط بدون تنش خشکی به دست آمد. ارقام الوند و چمران بالاترین شاخص کلروفیل، راندمان کوانتومی و عملکرد دانه را تحت شرایط تنش خشکی دارا بودند و به عنوان ارقام متحمل به تنش در این مطالعه شناسایی شدند. متن کامل این مقاله به زبان انگلیسی می باشد. لطفا برای مشاهده متن کامل مقاله به بخش انگلیسی مراجعه فرمایید.لطفا برای مشاهده متن کامل این مقاله اینجا را کلیک کنید.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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