سابقه و هدف: در انسان مواد مخدر و سایر ترکیبات وابسته از ترشح فیزیولوژک آدرنوکورتیکوتروپین از غده هیپوفیز جلوگیری می کنند. هدف از بررسی حاضر تعیین ارتباط فیزیولوژیک بین سطح سرمی کورتیزول بیماران معتاد و نارسایی غده فوق کلیوی در آنهاست.مواد و روشها:...

در این تحقیق دو عامل خونی شامل قند خون و هورمون کورتیزول و تغییرات آنها نسبت به مقادیر مختلف شوری در ماهی کپور معمولی (Cyprinus carpio) مورد مطالعه قرار گرفتند. در 7 آکواریم 100 لیتری غلظت های، (آب معمولی) 0، 3، 6، 9، 12، 15 و 18 گرم در لیتر نمک طعام...

زمینه و اهداف: نقش پالس اکسیمتری در تشخیص زودرس هیپوکسمی در مطالعات مختلف مورد تاکید قرار گرفته است. پزشکان معالج همواره نگران ماهیت بحرانی و حیاتی مشکلات تنفسی و هیپوکسی در بیماران خود بوده اند. اما در کلینیک، اینکه چه سطحی از هیپوکسمی قابل تحمل...

زمینه و اهداف: اختلال دو قطبی نوع 1، بیماری شایع، عود کننده و مزمن شونده ای است که می تواند عملکرد شغلی و اجتماعی بیماران را مختل کند. مطالعات فراوانی برای یافتن روشهای درمانی مناسب برای این بیماری انجام شده است. برخی مطالعات حاکی از آن است که افزودن...

این مطالعه به منظور ارزیابی اثر ضد قارچی روغنهای فرار استخراج شده از آویشن، پونه، ترخان، نعناع و پونه در پنیرهای سفید صنعتی طراحی و به اجرا گذارده شد. روغنهای فرار گیاهان مورد مطالعه در دو غلظت 0.3 و 0.4 درصد به پنیرهایی که جمعیت قارچ (کپک و مخمر)...

پلاک دست دندان عاملی مهم در ایجاد بیماری استوماتیت دست دندانی است. برای جلوگیری از اثرات ویرانگر ناشی از انباشت پلاک بر روی مخاط دهان، تمیز نگاه داشتن پروتز بایسته است. دندانپزشک باید با تاکید بر آموزش بیمار و دندانپزشکی پیشگیری، بتواند تمیز کننده ای...

Use of brick masonry infill panels is a common practice in construction of reinforced concrete structures. Generally, infill panels are considered as non–structural elements and their effect is not contributed in analysis and design. During an...

Concentrically Braced Frame is a structural system which resists lateral forces by forming a vertical truss system and it has also become one of the most common framing systems in regions of high seismicity. Researches on the behavior of CBFs...

In normal foundation construction, piles are used in groups, where the response of the group is influenced by closely spaced piles. This paper contributes to develop a simple efficient, closed form solution to determine the interaction between piles...

Nowadays, many buildings and infrastructures are made of concrete and therefore, strength of concrete structural members ensures longer useful life and serviceability of the structure. Beams are one of the most important structural members that must...

According to recent earthquakes, non–ductile reinforced concrete frames suffer from excessive damages and cause loss of life. Concentric bracing systems have been used to strengthen and rehabilitate weak RC structures during past decade. In this...

The framework of the activities carried out by Accelerograph Network Center of Iran (ANCI) is: design, installation, management, data collection, data processing, and the data bank of the network. The Strong Motion Network of Iran has started its...

The research work is to explore the potential of a multi–disciplinary approach (structural engineering combined with social science) in mitigating the effects of earthquake disaster. The objective is to investigate the role of national and local...

in this paper several collapse pattern of buildings during earthquake are indicated. Collapse pattern are usually well understood by professionals trained in earthquake engineering. However, it is difficult for laymen to understand why and how...

A new technique of seismic retrofit of RC columns has been applied in this paper. Pre–stressed high strength metal strips are externally applied to RC columns. Eight large–scale RC columns with insufficient transverse reinforcements were tested under...

This study highlights the principles of assessing and retrofitting of structures against seismic events. Furthermore, modern retrofitting techniques using a case study of a six storey reinforced concrete gravity design building is illustrated. The...

The finite element method was introduced in marine structural design with a significant delay with respect to other fields, as for example automotive, aircraft and aerospace industry, since the high degree of conventionality of these structures...

In this paper the static instability of a cantilever nanobeam with considering van der waals force and fringing field effect is investigated. The nonlinear differential equation of the model is converted into linear equation by using step–by–step...

حداکثر بارپذیری سیستم ، جلوگیری از ناپایداری استاتیکی و فروپاشی ولتاژ ، حفظ پروفیل آن از مهمترین مباحث در سیستمهای قدرت است. در این مقاله یک روش جدید و موثر برای مکانیابی مناسب جهت نصب Static Var ) SVC (Compensator به منظور جلوگیری از فروپاشی ولتاژ،...

In this article we introduce a new version of Incremental Dynamic Analysis (IDA) by which the effect of earthquake duration on the nonlinear dynamic response of the structure seems to be more obvious. We believe that the input energy of earthquakes...

Large number of collapsed sinkholes had been developed 15 years (1989–2004) in Famenin and Kabudar Ahang plains, Hamadan province, west of Iran. This paper discuses the Hamadan sinkholes conditions and their mechanism of formation. There is Iimestone...

Collapse of non–engineered masonry jack arch roofs and floor slabs during the Bam earthquake was a major contributor to the large fatalities during that earthquake. In this paper the seismic performance of different types of jack arch roofs as...

Welding quality is one the effective and basic factors that influences seismic damageability of building structures. Bam earthquake thought us that the matter of welding quality must be mentioned as important as other factors of strengthening....

Externally bonded fiber–reinforced–polymer (FRP) sheets have been successfully used for strengthening of damaged or deficient reinforced concrete members. Despite of a lot of research conducted and tests on application of these new sheets during the...

Seismic resistance structures must have sufficient ductility to absorb and dissipate earthquake energy and enough stiffness to minimize the structural damages due to excessive drift. To meet these, knee braced steel frame (KBF) was proposed which...

Steel bracing has proven to be one of the most effective systems in resisting lateral loads. Disadvantages of seismic behavior of common braces such as ductility, buckling and also unsymmetrical hysteresis performance in tension and compression...

Piles are normally constructed in groups and close to each other. This causes that piles interact. This paper develops a new approach for determination of interaction factor between closely spaced piles in the group. The segment by segment method...

An increasingly important objective for the structural reliability community is the incorporation of advanced reliability methods into current engineering practice. One initiative to address this objective is the development of nonlinear finite...

Steel sheet piles driven in harsh marine environments are sometimes so corroded that cannot be repaired effectively through coating them with retrofitting materials since due to high corrosion rates –commonly happens in splash\tidal zones– the...

The pressuremeter used was essentially the PENCEL pressuremeter (PPMT), manufactured by ROCTEST, Inc. This paper offers a description of the equipment, testing procedure, theory to obtain parameters of the ground and to develop the p–y curves for...

This paper investigates the optimized parameters for the tuned liquid column dampers (TLCDs) to decrease the earthquake vibrations of high–rise buildings. Considering soil effects, the soil–structure interaction (SSI) is involved in this model. The...

This paper reports on a new bridge deck slab flange–to–flange connection system for pre–cast Deck Bulb Tee (DBT) girders. In prefabricated bridge system made of DBT girders, the concrete deck slab is cast with the prestressed girder in a controlled...

We live in a world of dramatic and incessant change. What worked yesterday may no longer be relied on, and what we once knew as true may no longer apply. In this turbulent sea of change we must also change if we are to succeed or even surviv e....