Showing 11 results for Ms
Volume 8, Issue 2 (10-2009)
Abstract
Propolis or bee-glue is a natural sticky material gathered in the hives by worker honey bees (Apis mellifera L. ,Apidae) from the growing parts of trees and shrubs (e.g., leaf buds, trunk wounds). Typical propolis has approximately 50 constituents, primarily resins and vegetable balsams (50%), waxes (30%), essential oils (10%), and pollen. At least, 180 different compounds have been identified so far in propolis. The aim of this study is to examaine antimutagenesis effects of cosmetic creams containing ethanolic extract of propolis (EEP) against two mutagenic substances named sodium azide (NaN3) and potassium permanganate (KMnO4) by Ames test and microsome. In this test, various strains of Salmonella typhymurium TA100 and TA97 were used each having selective mutation in their operon histidine. Mutant strains (His-) were grown on culture media containing minimum salt and glucose in the presence of mutagen substances above. So, only those bacteria that reversed by mutation (His+) could grow and form colonies on culture media. If antimutagen (EEP) and mutagen substances are gathered, the rate of reversed mutation is reduced and the percentage of mutation inhibition can be calculated by means of the formula. In addition, the significant difference between the average of revertants per plate of the sample in relation to the mutagens was assessed by using statistical software SPSS and interpreted by one-way variant statistical test. Finally the results of in vitro antimutagenicity tests revealed that propolis in 0.1-4% concentrations could inhibit mutagenicity of two mutagens mentioned above in a dose-dependent manner. Also the results of microsomal assay (S9) revealed that propolis has a very high potential for inhibition of mutation and cancer. For these reason, ethanolic extract of propolis in defined concentrations can be used in cream formulation due to these reason
Bahman Soleimani,
Volume 10, Issue 2 (2-2010)
Abstract
The Shadgan petroleum oil field located in Dezful Embayment is a symmetrical anticline with 23.5Km length and 6.5Km width in the Asmari top horizon. The field trend is similar the regional Zagros trend. Asmari reservoir consisted of two separated reservoirs. The aim of the present study is to construct stratigraphy and faults models, reservoir quality evaluation, fault impacts and oil volume determination using RMS software. To construct the structural model, faults and reservoir zones data will be applied to design reservoir geometry. Stratigraphic and fault models revealed that the faults passed through the reservoirs but have not affected on their relations. This fact is verified by different petroleum API in two reservoirs and their independent pressure variations as well during production period. With correlation of faults, porosity distribution and reservoir volume models, it was revealed the fault effects in the reservoir properties quality.
S Bazm, Esmaeil Babolian,
Volume 11, Issue 2 (2-2011)
Abstract
In this paper, we use operational matrices of piecewise constant orthog-
onal functions on the interval [0,1] to solve fractional differential , integral
and integro-differential equations without solving any system. We first ob-
tain Laplace transform of the problem and then we find numerical inversion
of Laplace transform by operational matrices. Numerical examples show
that the approximate solutions have a good degree of accuracy.
M. E. Azim Araghi, Ensieh Khalili Dermani,
Volume 13, Issue 2 (7-2013)
Abstract
In this research work nano porous silicon layers with different porosity were prepared by using electrochemical etching. Surface morphology and size of pores were investigated by scanning electron microscopy (SEM).TiO2 thin films with EBPVD method have been deposited on the surface of PSi layers. The influence of anodization conditions such as anodization time interval and current density on electrical properties and surface morphology of sandwich devices were carried out using I-V measurement .The results showed that, electrical properties were influenced by changes of current density and anodization time interval. We also investigated the AC electrical conductivity of Al/TiO2/PSi/Al sandwich devices over the range of frequency 102 to 105 Hz and temperature range 300 to 378 K. It is known that, over the range of frequency < 103Hz the band theory and over the range of frequency > 103Hz hopping mechanism is applicable in explaining the conductivity of TiO2/PSi thin films nano structures with aluminum electrodes.
Zhaleh Ebrahimi, Ali Asghar Shokri,
Volume 14, Issue 1 (4-2014)
Abstract
in this paper, the effect of rough interface is investigated on spin dependent transmission in a magnetic tunneling junction. For calculating of transmission probability the transfer matrix technique and the approximation of effective mass is used in calculations. The mentioned magnetic structure includes of two semiconductor ferromagnetic separated by a nonmagnetic layer which is attached to two metal nonmagnetic electrodes. The different components of spin dependent transmission probability (direct and indirect) in the presence of roughness is studied while the roughness is distributed as random islands in interfaces. The results of calculations show that roughness affects the transport of incident electrons through mentioned double barrier structure, effectively. Because the scattering due to roughness of interface and therefore opening addition conduction channels, results to reduce the peak of incident electrons transmission probability. Also, the effect of percent of interface roughness is studied on component of indirect transmission probability.
Me Azimaraghi, Sn Riazi, Salar Porteamor,
Volume 14, Issue 3 (10-2014)
Abstract
In the present study, we investigate DC conduction mechanism of electron beam evaporated Bromoaluminium phthalocyanine (BrAlPc) thin films using aluminum and gold electrodes. The current-voltage characteristics of sandwich type device are evaluated for the temperature range 298-413K under dark conditions. It is observed that the current passing through the device is increased by increasing temperature at the same voltage in the range of 0-6v. It is found that at lower voltages about 0 to 2v, the current–voltage characteristics demonstrate Ohmic behavior, while the space charge limited current (SCLC) becomes apparent at higher voltages about 2 to 6v, which is restricted by single discrete trapping level. We obtained more than one linear region in the temperature dependence of electrical conductivity. Also, the values of charge carrier mobility and the activation energy of device are evaluated.
Hamidreza Nassery, Zahra Kayhomayon, Mohammad Nakhaei,
Volume 16, Issue 42 (5-2015)
Abstract
The present study aimed at identifying the nitrate transport in the groundwater of Lenjanat plain, Isfahan. Nitrate concentrations were measured seasonally and groundwater flow was modeled for nitrate transport simulation using MODFLOW and MT3DMS codes. The nitrate concentrations were compared with the human and livestock drinking water and irrigation water standards. The results show that nitrate concentrations are higher than the guidelines limits in groundwaters. The flow modeling reveals that the groundwater flow system of the study aquifer has been influenced by the aquifer hydrogeological characteristics. The falling watertable and reduce aquifer storage are due to the anthropogenic stresses on flow system. The transport model calibration and sensitivity analysis shows that nitrate leaching from agricultural land, first–order irreversible rate reaction, effective porosity and precipitation are the major factors affecting the entry and retention of nitrate in Lenjanat groundwater. Denitrification rate in the aquifer has been decreased due to high concentration of dissolved oxygen in groundwater and low extent of organic carbon. Half-life of nitrate in Lenjanat aquifer is more than 2.5 years. Nitrate transport in the aquifer is mainly by convection. Considering the calculated mass with transport model, the nitrogen leaching to groundwater of study area is 108 kg N ha-1 yr-1.
Azhdar Soleymanpour Bakefayat, Nader Dastranj,
Volume 17, Issue 40 (9-2015)
Abstract
In this paper, We Stabilize a subclass of nonlinear control systems by using neural networks and Zobov's theorem. Zobov’s Theorem is one of the theorems which indicates the conditions for the stability of a nonlinear systems with specific attraction region. We applied neural networks to approximate some functions mentioned in Zobov’s theorem, So as to find the controller of a nonlinear controlled system which is difficult task to find its law in mathematic manner. also we apply nelder meed optimization method to learning neural network. Finally, the effectiveness and the applicability of the proposed method are demonstrated by using some numerical examples.
Volume 18, Issue 48 (2-2007)
Abstract
A numerical method for solving variational problems is presented in this paper. The method is based upon hybrid of Hartley functions approximations. The properties of hybrid functions which are the combinations of block-pulse functions and Hartley functions are first presented. The operational matrix of integration is then utilized to reduce the variational problems to the solution of algebraic equations. Illustrative examples are included to demonstrate the validity and applicability of the technique.
Volume 18, Issue 56 (9-2006)
Abstract
Multiple sclerosis (MS) is one of the degenerative diseases of the central nervous system (CNS), which results in the destruction of myelin sheath. MS could be induced in laboratory animals, by injection of ethidium bromide (EB) into Cerebrospinal Fluid (CSF). This disease may cause impotence or subfertility in men. The objective of this study was to evaluate the role of MS on spermatogenesis, sperm parameters such as… and sex hormones of wistar rats. A total of 36 rats (5 weeks old) were divided into 3 groups of control, sham and experimental. 20ul of physiological saline was injected into cerebellomedullary cistern (CC) of rats in sham group, and, 20ul of EB was injected into CC of experimental group. One week after EB injection, two rats from each group were killed randomly to investigate the morphology of pons. The rest were killed 5 weeks after injections to study the spermatogenic cells, sperm parameters and sex hormones. The results showed that sperm progressive motility was significantly reduced from 74.4 2.2 in control group to 60.61.4 in experimental group (p<0/001). Also, the number of round cells was increased from /73 0/1 in control group to 2.16 /25 in experimental group (p
Volume 18, Issue 56 (9-2006)
Abstract
Premenstrual syndrome is a common cyclic problem among the young and middle -aged women which occurs in the luteal phase of the mestrual cycle. It is characterized by a combination of distressing physical, psychological and behavioral symptoms. The prevalence and frequency of syndrome (PMS) was assessed in all students living in an undergraduate female dormitory of Teacher Training University. The results of this study showed that among 326 nuliparous students, 98.2% of them regularly experienced symptoms consistent with PMS. The 4 most common symptoms were abdominal pain, backache, depression and anger. In this study the most disagreeable symptoms were abdominal ache (29.1%), backache (21.6%), anger(9.7%) , anxiety( 9%), and social withdrawal (8/80%) . There was an association between the city of origin and some of the symptoms such as: depression and acne in north of Iran and abdominal ache and back pain in east of Iran. About 43% of students had familial history of PMS and 51% of them took drug for decreasing their symptoms. A severe form of Premenstrual syndrome is premenstrual dysphoric disorder (PMDD), which its prevalence among the university students was 16.9% .
