JOURNAL OF SCIENCES (ISLAMIC AZAD UNIVERSITY)
Year:2000 | Volume:10 | Issue:35-36|Papers Count:13

Poly (4, 4 - Oxybisphenylene pyromellitimide), which is called Kapton-H is synthesized by two-step condensation polymerization. Aromatic diamines react with pyromelliitic dianhydriede in a solvent such as dimethylformamide to form solution of high molecular weight polyamic acid. These soluble polymers can be converted by thermal curing until 220 C to insoluble aromatic polyimides. This polymer has excellent thermal oxidative stability. For synthesis of 4, 4 - oxydianiline. Preparation was carried out till the formation of para-nitrodiphenyl ether. Nitration of chorobenzene was conducted and then it was reacted with potassium phenoxide in presence of activated copper as catalyst. After vaccum distilation, para nitrodiphenyl ether in yeild of 75% was achieved. FT-IR and FT-NMR showed characteristics of synthesized material.For second monomer, pyromellitic dianhydride after the chloromethylation of on meta - xylene, we obtained four - substituted deriviations of 4, 6 – bis (chloromethl), mera xylene of 66% yeild oxidation was down by nitric acid and followed by potassium permanganate. The products were studied by FT - IR and FT - NMR methods.

Self condensation of acetone in the presence of potassium hydroxide, as zubakhin report, conducted to mesityl oxide, D-Pulegone, isopulegone, thoujone and cyclohexanone formation. In our research work, by using the same method, the major products were isophorone (63.7%) and mesityl oxide (13.9%), and no evidence of D-Pulegone, isopulegone, thoujone and cyclohexanone formation was observed.

In the present paper, an attempt is made to explain the behavior of the magneto hydro - dynamic (MHD) instabilities in low-edge safety factor q(a) on the basis of the experimental results on the Iran Tokamak (IR-Tl). The poloidal magnetic field fluctuations at the Mirnov coils are observed and width of m=2 magnetic island is obtained. The rate of island growth and characteristic time t for the growth of the m=2 mode is estimate and experimentally and theoretically deduced value reasonable agreement. Reproducible major disruptions are observed and triggered by intersecting of a large m=2 magnetic island with the inside of the limiter.

Certain photosynthetic responses and proline accumulation in Champa rice (Oryza sativa L.) cultivars Zayandehrood, Sazandegi, Sorkheh and Nougaran under NaCL salinity were investigated with the aim of identifying salt resistant cultivars. Plants were raised in nutrient solutions. Through which the NaCI stress (7.5 mMohs cm-1 Ec=4800 mg lit-1) were applied to plants. All experiments were Carried out as based on fully randomized design and repeated three times.Results indicated that the content of chlorophylls a, b and the total chlorophyll decreased significantly under stress conditions. The contents of proline, β -caroten and soluble sugars increased but the contents of xanthophyll and starch did not change significantly under NaCI sterss. In order to study the extent of responses of plant cultivars towards the NaCI Salinity. The cultivars were subjected to the salinity stress under the four EC values of 0,5,7.5 and 15 mMohs cm-1 = 0,3200,4800 and 9600 mglit-1 The results indicated that at the tolerance threshold of EC=7.5 mMohsCm-1 the content of proline was greater in Sorkheh and Zayandehrood than that in Sazandegi and Nougaran. With increasing the salinity in the root medium (Ec=15 mMohsCm-1) the content of proline increased in Sazandegi and Nougaran as compared with that of Sorkheh and Zayandehrood.

Kopet Dagh Sedimentary basin is located in north of Iran. Several gas fields are in the area. Mozduran formation which is dominantly composed of carbonate rocks, is the main reservior rock of the gas fields. Evaporites (gypsum and anhydrite) comprise an important sequence of Mozduran formation in the most eastern part of the basin near Afghanistan and Turkamanestan border.The evaporates sequences of the Mozduran formation have locally separated carbonate reserviors and thus have caused considerable effects on the productivity of some of the wells specifically in wells of Gonbadli field. The origin of the evaporates are dominantly sabkha environment and much smaller part of them are lagoonal. Burial diagnosis caused formation of small amount of anhydrites as authigenic mineral. These evaporates are massive to thin bedded and have chicken - wire and nodular structures, and primary or secondary textures such as felty, fibrous, radial to radial fan, lath or bacillary, mosaic, chevron or swallow tail, irregular to regular crystals, rod - like and scattered single crystals. Anhydrite replacement is another diagnosis processes.

To extract boron from boric acid, we obtained first boron oxide after a two steps dehydration. This oxide was then reduced to metallic boron at l000°C. After three steps of consecutive distillation, in concentrated HCI, alcoholic potash, and HF boron was separated from the impurities. It was then burned at high temperature until pure B2O3 is produced. The above preparative steps were repeated many times to obtain boron with a purity of 95.8% and 44.4% yield. To determine the purity of product, potentiometric methods and AAS were used. The impurities were determind by PIXE method.

The place of evaporate mass in Garmsar was belonging to Tertiary period and mostly consist of Evaporate rock, Gypsum, Salt, Sediments of Clay and Marl and red down formation with considering thichness from sediments and Shallow marine fades and sediments of basins of evaporate Eocene & oligocene in all over the area and represent the relationship of Tectonic with younger formation. From the most effective orogenic in this area are late alpionorogenic Which have a strong effecting on Central Alborz and caused the folding and changed the process of old faults.Involving the plate central of Iran with Khazar and the effecting of the tension from collision the plates of Arabia with Iran caused different structural from in both curvature of central Alborz and relative turning of major plates of collision in the length of crustal faults are considered as the most significant structural changes.The evaporate mass of upper & down red formation in this area which made the gradual zone between central Iran and Alborz by having the considering thickens of Gypsum sediments and salt in effecting of strong Dynamic stimulation the central Alborz has been folded and under the effection of Diaprism and salt structural of the area expressed that the tension of diprism are more than similar basin in Central Iran and has continued yet.It is certain that, the area fold and the development of the result of faulting and continuous the curvature of central Alborz are the reason of rising of salts.

In order to compare the efficiencies of Power Plants in Iran, Data Envelopment Analysis (DEA) is used, with as inputs production condition which contains four factors of production, fail, fuel, age, and hardness, number of disobedience’s from the dispatching commands, and number of personnel, and as outputs units performance factor, availability factor, capability factor, capacity factor, and performance factor.Results are given and discussed for different choices of inputs and outputs and also for two kind of categories of power plants. Technical efficiencies evaluated by DEA seem very promising in comparison with the scores given by the existing methods.