۱طراحی و نظارت بر حفاظت کاتدی سکوهای دریایی
اطلاعات انتشار: سال
تعداد صفحات: ۱۱
One of the important subjects about protection systems for offshore plaforms is that of its Designing and monitoring cathodic protection. In the early years Dwight equation and those simillar to it were used for designing cathodic protection system. As anode coerrode, their dimentions change. In addition sea conditions such as temprature change, salinity variation, Current speeds of water and calcareous deposits formations on underwater parts of offshore plateformes are all variables, that make, Dwight and simillar equations of no use for answering problems concerning design of cathodic protection systems. Today computer modeling is succestully used for designing and monitoring cathodic protection system. In this type of process potential distribution at each part are obtained by measuring potentials of only limited number of points of the offshore plateform. In this article we not only discuss the above subjects but also we talk about a technology for monitoring cathodic protection systems in offshore platforms, equipment used for this purpose and manipulation mathematical calculation used for cathodic protection system. Also in this article methods and related equipment used as data acquisition system, its classifications, mathematical calculation and finally the application of computer in this regard, are all discussed

۲آشکارسازی حفره های زیرسطحی به روش مقاومت ویژه Bristow
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۶
Electrical resistivity method is a suitable tool for investigation on subsurface inhemogenities including subsurface cavities and karst. One kind of resistivity configurations for detection of subsurface cavities is Bristow method. In this method, Pole–Dipole array and a graphical technique for interpretation of field data are applied. The aim of this research is evaluation of Bristow method in detection of subsurface cavities and comparing it with other linear resistivity arrays. Comparisons among different resistivity arrays confirm that Bristow method is an applied and logical way for detection of subsurface cavities and karst.

۳اثر اندازه گیری PMR در تفسیر بهینه مقاومت ویژه الکتریکی
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۴
Groundwater detection by PMR method can obtain an important information like number of equifers, depth and thickness of each equifer together with its water content. Although the resistivity method is an indirect method for ore and equifer detection, but the ability of the method in detecting equifer thickness and performance is not good for the interpretation. So the PMR method is a complementary method for optimum groundwater detection. The interpretation of resistivity method for Qom plane have been done using PMR sounding and the optimum drilling point

۴اکتشاف اورانیوم به روش ژئوفیزیک هوایی در فاز شناسایی در منطقه برندق
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۶
The available radioactive elements in the nature, in themselves decay series to other elements, emit alpha, beta and gamma rays that attention to power of penetration of gamma ray is used from this gamma ray measurements, for radiometric exploration of radiometric element specific for uranium. With use taken data of airborne radiometric simply can be studied a large area in a short time and with a little cost. In this paper, at the first, The tables of frequency distribution of uranium and thorium are designed, and then the frequency distribution histograms that are introducer of distribution and dispertion of uranium and thorium are designed. After drawing frequency distribution histograms the statistical parameters of these elements are estimated. then separation of anomaly value are done based dispertion around the average. At the end introduction of anomaly maps and separation of anomaly values and background are prepared on the base of calculations of classic statistics.

۵استفاده از تبدیل موجک بر روی داده های گرانی و تعیین عمق و شکل توده
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۶
One of the main objectives in interpretation of gravimetric data is determination of depth and structure of the mineral deposits. This article tries to use the wavelet transform as a new method for achieving such a goal. The advantage of this technique over traditional methods is the ability of differentiating the small and large anomalies easily by using windows of different sizes. In this paper we try to apply this method on gravimetric data, to find the depth and structure of the mineral deposits and compare the results of an artificial model with hypothetical one. This method has proved to be satisfactory at least for the one dimensional example mentioned above.

۶اینورژن دو بعدی داده های مقاومت ویژه با استفاده از شبکه های عصبی مصنوعی
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۱۱
The inversion of geoelectrical resistivity data is an important task due to its non–linear nature. Several methods have been suggested for solution of inversion problem. Artificial neural networks are considered as an intelligent system for transferring information of experimental data into network. These intelligent systems are trained on the basis of numerical data calculation. Artificial neural network processing encompasses a broad range of computer algorithms that solve several types of problem. Neural networks can be interconnected in many different ways leading to a variety of neural networks with different architectures, learning rules and abilities. The aim of this article is design of fundamental software for training of artificial neural networks that these trained networks can be applied for different geological structures and by using this software the efficiency of artificial neural network and its applicability to solve ٢D inversion problem investigate.

۷تاثیر اعمال خطاهای نگار چاه در تخمین موجک
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۷
A Bayesian inference for wavelet estimation from seismic and well data is studied. The forward model is based on the convolution model where the reflectivity is calculated from the well logs. The estimated wavelet is given as a probability density function such that uncertainty in the wavelet is considered in the problem. Seismic noise and possible mistie between the seismic and well time axis are included in the model. The wavelet estimation is obtained by Markov Chain Monte Carlo (MCMC) simulation and the gibbs sampler as one of its algorithms.

۸تشخیص زمینلرزه و انفجار به کمک تبدیل موجک نمای هورست محلی
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۶
In this paper, the application of fractal methods of local Hurst exponent and their wavelet transform, to differentiation between time series seismograms of earthquake and explosion is considered. By using the Hurst exponent, short or long–range memory in a time series, would be determined and for their local time behavior, the local Hurst exponent is applied instead of typical Hurst exponent. In this case Daubechies' wavelets with fractal structure can be helpful for better analysis. In this study, first we consider three important factors: discreteness, long–range memory and local– time behavior, for seismic signals recorded on the seismograms, then the Hurst exponent in typical time feature, has been transferred to time–frequency environment for doing better analysis. This approach, permitting us to obtain an algorithm for noisy and much damping data, in comparing with the normal time dependent method.

۹تشخیص گسل مدفون صحنه در منطقه کرکسار با استفاده از روش مغناطیسی و VLF
اطلاعات انتشار: سال
تعداد صفحات: ۱۳
Magnetic surveys were performed in the eastern part of the Kargesar village which is on the road between Bisetoon to Songhor towns to identify Sahneh fault. About ٢٠٠ magnetic stations were established in which magnetic data were collected with GSM–١٩ magnetometer. In addition to magnetic data of each point, VLF data have also been collected with the same magnetometer. Interpretation of magnetic and VLF data indicate the location of the buried fault of Sahneh region near Kargesar village. Magnetic data gives the upper level of fault and its dip ٣٧ meter and ٧٤ degree respectively. The station frequency in VLF measurements is ١٨٫٦ KHZ.

۱۰تعیین گسترش کانیسازی اورانیوم با استفاده از همبستگی چاهها در منطقه اکتشافی خشومی
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۷
To get a concept of the spread and distribution of uranium mineralization in a selective section, one of the fast methods is natural gamma–ray logs correlation for boreholes located at those sections. So the, digital gamma–ray logs of four boreholes located at one profile, in Khoshoumi area in central Iran, are processed and analyzed. Different processing methods was tested to find the best and clearest delineation of this section. With regard to the fact that mineral and uranium mineralization distribution are lenticular in this area, the process based on inverse distance to a power is the most suitable method in comparison with other methods and shows the best fit with geological observations in the area.

۱۱تشخیص دیواره ها و تعیین عمق آنها در سایت باستانی عمارت خسرو با استفاده از روش مغناطیسی
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۱۴
One of the geophysical methods is magnetic method that has been used in archaeological prospecting. This method is a primary survey at low cost and very fast in viewpoint of time without any damage to a site. This method has been used to map the historical site (Emarat Khosro) in Ghasr–e–Shirin in Kermanshah province. Total magnetic field and magnetic gradient field were used on this site. Interpretation of magnetic data indicates the location and depth of the walls.

۱۲تفسیری بر برداشت های لرزه نگاری کم عمق در استان لرستان
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۶
Two seismic lines (Shallow Reflection – High Resolution) were shot in Lorestan Province in order to define the weathered layers, crashed zones and faults trend, and to recognize the bed rock with high resolution. At first, the survey for the stages of shallow reflection seismic was designed. After acquiring the data, they were processed by Winseis Turbo Software. The results then were interpreted by taking into consideration the region geology and characteristics of wells. The outcome of this study is recognition of trend of weathered layers and crashed zones, the main fault, minor faults and also the bed rock. In addition, travel time – distance curve and finally tomography sections were prepared by using the first breaks of each line.

۱۳چگونگی تشکیل اقیانوس های بازالتی ماه: همرفتی ناشی از برخورد شهاب سنگی و تولید مذاب در جبه ماه
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۴
We present impact–induced convection models in the Moon that explain the formation of lunar mare basalt, and the long duration of the basaltic flow. A large projectile that produces an Imbrium–size impact basin can induce three stage of melting at different depths. The first occurs near the surface, by strong heating of the projectile and target that results in melting and vaporization of the major part of the projectile and near–surface part of the target. This rapid melting does not create mare basalt. The second melting arises from the sudden reduction of the pressure in the upper mantle due to excavation of the basin. The ascending upper mantle material in the process of isostatic adjustment in response to the excavation partially melts by decompression within less than a few Myr after the impact. The possible related volcanism cannot explain basaltic flow on the Moon that lasted about ٨٠٠ Myr. The local impact–induced perturbations, however, trigger global–scale convection, and a large plume from lower mantle ascends directly beneath the impact basin. This convection causes the third stage of melting in the mantle and produces well over ١٠٧ km٣ of mare basalt that give rise to substantial mare flooding. We investigate the effects of an impact on the thermal evolution of the Moon and melt production in the mantle, using convection calculations in an axi–symmetric cylindrical coordinate system. The models have temperature–dependent viscosity, and time dependent heat sources arising from decay of radioactive materials. The mantle is allowed to melt as it crosses the solidus temperature and partial melting is calculated. We consider two different models, permeable and impermeable. Five different viscosity models are examined, where the ratio between the viscosity at the surface and at the bottom of the computation domain is ١٠٠, ٥٠٠, ١٠٠٠, ١٥٠٠ and ٢٠٠٠, respectively. The permeable model with viscosity contrast of ١٠٠٠ can explain the observed amount of basaltic flow as well as the duration of the volcanic eruption.

۱۴خصوصیات زلزله اصلی و پس لرزه های زمین لرزه 4 اسفند ما 1383 داهوئیه زرند کرمان
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۱۰
The Feb. ٢٣،٢٠٠٥ earthquake of Mw ٦,٤ shook west of Zarand in the southeast of Iran .This earthquake killed ٦١٢ persons and destroyed ٦٠ around villages . Field investigation and aftershocks distribution suggest a W–E faulting with northward dip,١١٠(cm)vertical dislocation , ٢٠‐٤٠(cm) right lateral strike–slip motion , ٨(km) surface and about ٨(Km) blind rupture. Enormous aftershocks were recorded by ٥ Stations of Geophysics Institute temporary network and about ٤٠٠ common aftershocks between them with ٤,٤ for strongest one which was separated is processed with other data's, like global and national telemetry network data's and GSI field investigation.

۱۵فعالیت لرزه خیزی ترکیه و مقایسه آن با لرزه خیزی فلات ایران
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۱۰
In this study we evaluated seismic region of Iran and Turkey during this century and from the comparison of this two, the result was obtained that the number of earthquakes in Iran exceeded Turkey. Anatolian plate seismotectonic conditions, is very similar to central Iran zone, special Tehran region. Meanwhile the activities of earthquakes in north of Turkey follow special arrangement that it have been seen in south of khorasan. low–depth earthquakes and strike slip mechanism in two region are caused high intensity, vast damage and many mortality during occurrence earthquakes. with pay attention seismic activity paterns and earthquakes migration, in south of Khorasan, Birjand and west of Turkey, Stambul city, We will have earthquakes in future.

۱۶کاربرد تابع انتقال گیرنده در مطالعه ناهمسانگردی (مطالعه موردی تعیین ناهمسانگردی پوسته البرز مرکزی)
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۷
Although there can be up to ٢١ independent elastic constants, any material in which more than two are needed is called anisotropy. More than two elastic constants means that the material’s properties differ depending on the direction. Seismic wave through anisotropic materials travel faster or slower depend on their direction. The shear wave can be spitted into two pulses, each with a different polarity and travel at a different speed. This phenomenon is called shear wave splitting. Shear wave splitting of different shear phases can be applied to determine the anisotropy parameters. Also, different shear velocities (fast and slow) of Ps phase on horizontal components of Receiver function can interpret the physical description of anisotropy phenomenon. In this paper, we attempt to automate the choice of analysis window by performing a grid search over different windows to find stable splitting measurements with minimum error. Finally, for determining anisotropy in the crust under centeral Alborz, we use ٤ events where recorded by DAMV seismic broad band station. In this study we find out the fast direction of hear wave velocity is about ٧٠ degree and its delay time is about ٠٫٣٣ second.

۱۷مطالعات مغناطیسی و رادار بر روی طاق های عمارت تاریخی خسرو در شهر قصر شیرین
اطلاعات انتشار: سال
تعداد صفحات: ۷
Magnetic and radar prospecting were done at Ghasr e Shirin town in Kermanshah province for detecting a large underground cavity ( Tagh ). The place of study is a historical monument which is named Emarat e Khosro. Magnetic and radar measurements have been done on the eastern part of the complex which is a place of some underground cavities. Magnetic and radar profiles indicate these cavities easily. Radargram , vertical derivative of magnetic field indicate the location of the anomalies which conform with the real situation. This work is completely experimental and research and was done for indicating the effect of underground cavities on magnetic and radar data. We conclude that the magnetic and radar methods are a good methods for finding the underground cavities.

۱۸مدلسازی وارون ترکیبی داده های مقاومت ویژه با آرایه های شلومبرژه و دو قطبی–دوقطبی بمنظور تعیین مسیر درز و شکافهای آبدار
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۶
The goal of this work is to determine the directions of fissures that contain water around the Well drilled in the distance of 1930m in main road of Tochal telecabine. To investigate this problem, a geoelectrical survey was conducted combining dipole–dipole and schlumberger arrays. At the beginning of the survey, schlumberger array profile carried out along the road. The electrical tomography obtained from the 2D inversion of the data showed anomaly with low resistivity between 7m to 30m of depth. Then one dipole–dipole array profile overlaying on the schlumberger array profile crossing the well carried out. To improve the inverse model using the vertical resolution of schlumberger array and the horizontal resolution of dipole–dipole array, we performed a joint inversion of schlumberger and dipole–dipole data. We conclude that the joint inversion improves the resolution of section obtained from each array separately._

۱۹مقایسه روشهای آمار کلاسیک و فرکتالی در معرفی اندیسهای معدنی اورانیوم، با استفاده از داده های ژئوفیزیک هوایی در فاز شناسایی منطقه برندق
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۶
In the primal stages of Uranium exploration, the main stage, is to use the airborne geophysics data taken by means of flights of airplanes containing gamma ray detectors. The results of these acquisitions, are the digital data and contour maps of radiometry. attention to distribution of Uranium element in the earth crust and study of these maps, the main parts of first stage of Uranium exploration are the factors and methods of sepaqration of boundaries and hot points of anomaly from background parts. In this paper, in the first method separation of anomaly values is done by means of classic statistics and by calculations of statistical parameres that criterion of this separation is based on the amounts of around of average. In the second method, separation of anomaly values is done by means of fractal geometry. In the fractal method. Separation has done by use of curve of concentration– area. At the end, the maps of anomaly introduction and mine index of Uranium are prepared to continue the exploration work.

۲۰مطالعه ی تولید و مهاجرت مذاب در مناطق فرورانش به کمک شبیه سازی جریان دو فاز
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۴
In this study we investigate the production and migration of melt in subduction zones with the aid of a numerical simulation. We solve the governing equations of the flow of a fluid melt phase through a porous and deforming mantle rock. We investigate the volume of melt produced and its subsequent movement under a variety of conditions. We find that the nonlinear dependence of the mantle rock permeability on its porosity is the defining factor in the time variations of melt production and the pattern of migration through the mantle. Furthermore, we investigate the importance of other parameters, such as the age of the subducting plate, and subduction dip and velocity.

۲۱Assessment of Wave–In–Deck Load Models For Jacket Platforms
نویسنده(ها):
اطلاعات انتشار: هفتمین کنگره بین المللی مهندسی عمران، سال
تعداد صفحات: ۸
In this paper, the influence of wave–in–deck load on the reliability of jacket type offshore platform is investigated . The APIRP2A and Kaplan’s models are considered. It is show that the API RP2A wave load model may offer a much smaller wave–in–deck load compared to Kaplan’s model. It is concluded that the reliability index of the jacket system may very significantly with the inclusion of the wave–in–deck forces. It is also shown that the influence of the wave–in–deck load model may be less profound in comparison to the choice of wave–in–deck and variation of air–gap itself.<\div>

۲۲NONLINEAR FE MODELING OF IN–PLANE BEHAVIOR OF PLAIN MASONRY WALLS AND INVESTIGATING EFFECTS OF POST–TENSIONING AS A PARAMETRIC STUDY
اطلاعات انتشار: پنجمین کنفرانس بین المللی زلزله شناسی و مهندسی زلزله، سال
تعداد صفحات: ۷
In this study, a general analysis tool for in–plane behavior of plain masonry walls has been introduced, and the effects post tensioning on lateral response of masonry walls have been investigated. The analysis tool uses the general–purpose F.E. code of ANSYS and incorporates the effects of bed joints, head joints, brick units, cracking, crushing, and sliding. The study indicates that axial force improves lateral strength but undermines lateral ductility of plain masonry walls.<\div>

۲۳نقش زمین ساخت جدید و داده های زمین لرزه های دیرینه در آنالیز خطر لرزه ای زمین لرزه ویرانگر 26 دسامبر 2003 سهرستان بم
نویسنده(ها):
اطلاعات انتشار: سومین کنگره ملی مهندسی عمران، سال
تعداد صفحات: ۱۰
The town of Bam with geographical coordinates of about 59o in eastern length and 28–29o latitude lies east south of Iran. Its distance to the border of Pakistan is about 370 km and to Tehran is about 6o, 51_ and 11__ and its height from high seas is 1050 m. Bam devastating earthquake with the magnitude of 6.5 degree on the scale of Richter which occurred on December 26 2003 caused killing of about 28000 people, wounding of 25000 persons. It made the rest 90 percent of residents in the town and its suburbs homeless, collapsing and devastating 85–90 percent of urban buildings and structures. The region of Bam is located between two large tectonic Lut depression at the north and Jazmourian depression at the south. Two main tectonic elements of Lut block and the zone of flysch extends to out of central Lut and includes the main part of eastern state of Iran. The block of Lut which Bam town resides in its western edge is an extended part with northern extension surrounded with different unstable faults which faults are often at the raw of seismic faults. Lut block extends to the more than 800 km from Jazmourian depression at the south to the region of Gonabad in Khorasan at the north. The average width of it in the central part and south is about 200–250 Km. Its western border is performed by an extended and main fault called Nayband. If we study the movement and action of Nyband fault, it is observed that it has experienced the segmentation of strike – slip fault, and faulting series of 1978–2004 is one of the most obvious type of segmentation which is observable on the ground and any segment of it has been activated at one time and this activity has been accomplished from north to the south, i.e. from Tabas city towards the country of Nayband (Nayband seismic fault is nominated through the same country) and from Nayband towards Shahdad and from there towards Bam.

۲۴Effect of quaternization alkylated chitosan chloride on colonal absorption enhancement (ex–vivo and in–vivo studies)
نویسنده(ها): ، ،
اطلاعات انتشار: پنجمین همایش مراکز تحقیق و توسعه صنایع و معادن، سال
تعداد صفحات: ۳۲
The intestinal absorption of peptides and proteins has a very low bioavailability due to extensive hydrolysis by the proteolytic enzymes and poor membrane permeability of gastro intestinal tract (GIT). Colonic drug delivery for either local or systemic effects has been the subject of much research over the last decade. Recent researches have determined that polymeric compounds are useful carriers for high molecular weight drugs. Biodegradable polymers such as chitosan have been used extensievly in medical fields. Chitosan with mucoadhesive properties and ability to interact with cell membrane is able to open the paracellular permeation of hydrophilic macromolecules. Chitosan exhibits poor solubility at pH values above 6.0 that prevent enhancing effects at sites of absorption of drugs. In the present work , triethyl chitosan (TEC) and N–diethyl methyl chitosan (DEMC) were prepared based on a modified twostep process via a 22 factorial design to optimize the preparative conditions. TEC and DEMC polymers with different degree of quaternization for pharmacological and pharmaceutical experiments were achieved. The reaction was optimized using different amounts of reactants. pH–metric titration and infrared methods predetermined the degree of deacetylation of the starting chitosan. TEC and DEMC were characterized using FTIR and 1H–NMR spectroscopies. Based on NMR calculation, high degree of quaternization was achieved through the optimized one and two–step procedures. The antimicrobial activities of chitosan and DEMC against Escherchia coli were compared by calculation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Our data indicates that although the antimicrobial activity of DEMC is higher than that of chitosan in acetic acid medium, the both compounds are pH dependent and an increase in concentration of acetic acid results in a significant decrease in both MIC and MBC. Ex–vivo studies have shown a significant increase in absorption of brilliant blue (as modeling drug) in the presence of TEC or DEMC in comparison with chitosan. TEC and DEMC with positive charges are able to interact with tight junctions of colon epithelia cells and hence increase permeability of brilliant blue across the tight junctions. In–vivo investigations have exhibited the absorption enhancer effects of DEMC on the colon absorption of insulin in normal and diabetic rats. The insulin absorption from the rat’s colon was evaluated by its hypoglycemia effect. A significant decrease in blood lucose was observed, when mixture of insulin and DEMC was introduced in ascending colon of rats.<\div>

۲۵Lifetime Extension of Transformers by On–line Drying
نویسنده(ها): ، ،
اطلاعات انتشار: سال
تعداد صفحات: ۹
Insulating liquids together with a solid insulant immersed therein is for many kinds of applications like power transformers since more than 100 years in use and remains for the near future still one of the most suitable insulating systems for many applications. A dominant parameter, accelerating the aging and reducing the strength of such insulations, is humidity, thus drying procedures are required to extend lifetime and operation reliability. This contribution presents new systems, which perform a continuous desiccation of the insulating system of power transformers during service and are beneficial for insulating liquids as well as for solid insulations immersed therein. The advantages of the different procedures in comparison to conventional approaches are discussed and an outlook on a new system for the reduction of the water uptake of breathing transformers is given.<\div>
نمایش نتایج ۱ تا ۲۵ از میان ۳۹۱۵ نتیجه