Constructing warm inflationary model in brane-antibrane system

Recently, various observational data predict a possibility that inflation may naturally occur in a warm region. In this scenario, radiation is produced during the inflation epoch and reheating is avoided. The main question arises that what is the origin of warm inflation in 4D universe? We answer to this question in brane-antibrane system. We propose a model that allows all cosmological parameters like the scale factor a, the Hubble parameter H and phantom energy density depend on the equation of state parameter in transverse dimension between two branes. Thus, an enhancement in these parameters can be a signature of some evolutions in extra dimension. In our model, the expansion of 4D universe is controlled by the separation distance between branes and evolves from non-phantom phase to phantom one. Consequently, phantom-dominated era of the universe accelerates and ends up in big-rip singularity. Also, we show that as the tachyon potential increases, the effect of interaction between branes on the 4D universe expansion becomes systematically more effective, because at higher energies there exists more channels for flowing energy from extra dimension to other four dimensions. Finally, we test our model against WMAP and Planck data and obtain the ripping time. According to experimental data, $N\simeq 50$ case leads to $n_{s}\simeq 0.96$, where \emph{N} and $n_{s}$ are the number e-folds and the spectral index respectively. This standard case may be found in $0.01 < R_{Tensor-scalar } < 0.22$, where $R_{Tensor-scalar }$ is the tensor-scalar ratio. At this point, the finite time that Big Rip singularity occurs is $t_{rip}=33(Gyr)$.Comment: 16 pages, 3 figures, Accepted in Phys. Lett. B. arXiv admin note: text overlap with arXiv:0708.3233 by other author

Isolation Virulence genes ETA, OPrL, gyrB in Pseudomonas aeruginosa clinical samples from hospitals in Kerman by Multiplex-PCR

زمینه و هدف: سودوموناس آئروژینوزا یک پاتوژن فرصت طلب و عامل عفونت های بیمارستانی و مرگ و میر به خصوص در بیماران با ضعف سیستم ایمنی می باشد و مقاومت ذاتی به مواد ضد میکروبی منجر به مشکلاتی در درمان عفونت های آن می شود. هدف از این مطالعه بررسی فراوانی ژن های حدت سودوموناس آئروژینوزا به روش Multiplex-PCR می باشد. روش بررسی: 60 نمونه سودوموناس آئروژینوزا شامل 40 نمونه از کلکسیون آزمایشگاه میکروبیولوژی پاسارگاد و 20 نمونه از بیمارستان های استان کرمان جمع آوری و در محیط های اختصاصی کشت داده و با آزمون های بیوشیمیایی تأیید شد. واکنش PCR بر روی تمامی نمونه ها برای شناسایی ژن های حدت gyrB, oprL, ETAو شناسایی جنس و گونه 16SrDNA صورت گرفت. یافته ها: از میان 60 نمونه سودوموناس آئروژینوزا، 38 نمونه (3/63) دارای ژن gyrB و oprL، 37 نمونه (6/61) دارای ژن ETA و هر 60 نمونه (100) دارای ژن 16SrDNA بودند. نتیجه گیری: با توجه به اهمیت تشخیص سریع این باکتری به جهت بروز مقاومت و مشکلات موجود در روش های بیوشیمیایی، شناسایی همزمان چندین ژن با روش Multiplex-PCR به&shy;عنوان روشی حساس و دقیق در شناسایی این باکتری به شمار می رود

Effects of Daphnia magna and Artemia nauplii on growth performance in Persian sturgeon Acipenser persicus larvae

This study was carried out in a completely randomized design 3×3×4 factorial arrangement in three periods of rearing in spring 1997. Density of 300 larvae was assigned for each oval tank with 0.1m2 surface area, 30cm deep, a volume of 20lit and 0.25 lit/min of water flow per minute at Shahid Rajaie fish breeding and culture center in Sari, north of Iran. The fries were divided into three groups according to their feeding regimes and fed with each of Artemia or D. magna separately, and mixture of the two (50% Artemia+50% Daphnia) in ratioes of 80, 100 and 120% of their body weights in the first period and 30,50,70% of their body weights in the second and third period of rearing. Each period lasted 72 hours. The result indicated, significant differences (p<0.005) between food organisms, body weight gain and Food conservation Ratio (FCR) in the first and third period of rearing. The highest body weight gain was found in 120% food ratio in the first period. The best survival rate achieved with fries feeding at 70% body weight of Artemia nauplii and mixed food in the second period of rearing. The highest growth rate, survival rate and the best FCR obtained when Artemia fed as live food to fries. There were no significant differences between Artemia and mixed food in this study. It seems that mixed food (50% Artemia +50% Daphnia) given at 70% of larval body weight results in a better performance

Hidden Conformal Symmetry of Kerr-Bolt Spacetimes

We extend the recent proposal of hidden conformal symmetry to the four-dimensional spacetimes with rotational parameter and NUT twist. We consider the wave equation of a massless scalar field in background of Kerr-Bolt spacetimes and show in the "near region", the wave equation can be reproduced by the $SL(2,R)_L \times SL(2,R)_R$ Casimir quadratic operators. Moreover, we compute the microscopic entropy of the dual CFT by Cardy formula and find a perfect match to Bekenstein-Hawking entropy of Kerr-Bolt spacetimes. The absorption cross section of a near region scalar field also matches to microscopic absorption cross section of the dual CFT.Comment: 9 pages, re-organized and re-writtend, typos corrected, main results and conclusion unchange

Real-time Measurement of Stress and Damage Evolution During Initial Lithiation of Crystalline Silicon

Crystalline to amorphous phase transformation during initial lithiation in (100) silicon-wafers is studied in an electrochemical cell with lithium metal as the counter and reference electrode. It is demonstrated that severe stress jumps across the phase boundary lead to fracture and damage, which is an essential consideration in designing silicon based anodes for lithium ion batteries. During initial lithiation, a moving phase boundary advances into the wafer starting from the surface facing the lithium electrode, transforming crystalline silicon into amorphous LixSi. The resulting biaxial compressive stress in the amorphous layer is measured in situ and it was observed to be ca. 0.5 GPa. HRTEM images reveal that the crystalline-amorphous phase boundary is very sharp, with a thickness of ~ 1 nm. Upon delithiation, the stress rapidly reverses, becomes tensile and the amorphous layer begins to deform plastically at around 0.5 GPa. With continued delithiation, the yield stress increases in magnitude, culminating in sudden fracture of the amorphous layer into micro-fragments and the cracks extend into the underlying crystalline silicon.Comment: 12 pages, 5 figure

Cytogenetic study on Artemia from Urmiyah Lake

To determine the chromosome numbers of artemia brine-shrimp in Urmiyah Lake (Azarbaijan-e- Gharhi province), cytogenetic studies were carried out on artemia cysts. In order to identify the collected samples, each sample of cysts, first incubated in sea water (35 ppt salinity) and then to determine the reproduction mode, the cyst samples were feed with Dunaliella tertiolecta, for three generations (F3) up to adult. The results showed that there were two types of anemia in terms of reproduction mode, namely bisexual and parthenogenesis. Chromosome spreads were prepared from freshly hatched nauplius squashing method. The results of counting 100 metaphases plates from bisexual artemia and 35 metaphases plates of parthenogenetic specimen, it was found that the number of chromosomes in these 2 types of artemia were the same, 2n=42. In these population, very small chromosomes with metacentric, submetacentric, telocentric and acrocentric types were observed. Karyotype formulas of bisexual and parthenogenetic artemia were determined as 2n=30 M / SM+12 A/T and 2n=32 M / SM+10 A/T, respectively. All studied samples in Interphase stage lacked and chromocenter. Due to very small size of chromosomes, it was difficult to do precise determination of the type of chromosomes and in this regard various C.banding experiments were performed. Also, since chromosomes in artemia lacked any chromocenter, the differentiation of chromosomes based on the types of C.banding was impossible

Modeling of wind energy conversion system using PSCAD/EMTDC

This paper aims to model a complete wind energy conversion system (WECS) connected to a grid. The motivation comes from the Distributed Generation System (DGS) installed at the Renewable Energy Lab at UMass Lowell. The objective of this work is to develop universal and standardized manufacturer independent textbook models. Manufacturer specific models are more accurate and detailed, but proprietary and non-disclosure agreements become an issue for research purposes. Since the wind turbines installed in the lab are VSWT (Variable Speed Wind Turbine) with Permanent Magnet Synchronous Generators (PMSG), so such a turbine system is modeled to represent them in general. PMSG requires very less maintenance and has high efficiency since it doesn't have rotor current and is used without a gearbox. Further, there are two more advantages: first, it has the capability of variable speed control due to the fact that its rotor speed can change in a large range; second, it's excitation system is independent of the grid and require any other excitation source. In addition to the turbine generator, other main components of WECS are also modeled namely: wind source model, wind turbine, permanent magnet synchronous generator and AC/DC/AC control. The equations governing these models are also discussed. The entire generation system is implemented on PSCAD/EMTDC and integrated to a grid and a basic fault analysis is done under different conditions. The proposed model can be used for research purposes on distributed generation issues. This model provides a good software simulation test bed for further research

A survey on age, growth and reproduction of Capoeta capoeta gracilis of the Madarsoo River, Golestan National Park, north-east Iran

In the years 2001 and 2002, two great floods occurred in the Madarsoo River in Golestan National Park, north-east of Iran. To study the effects of these floods, we assessed the age, growth and reproduction of Capoeta capoeta gracilis (Keyserlhng, 1861) in the river from November 2003 to December 2004. Fishes were caught by electroshocker and 1025 specimens were randomly selected from the catch. Growth in length was expressed for both sexes with Von Bertalanffy equation. Growth parameters were estimated as L infinity =249mm, K=0.22 per year and t _ (0) = -0.30 year for males and L infinity =306mm, K=0.21 per year and t _ (0) = -0.38 year for females. The length-weight relationships were described for males as lnW= -4.48 + 3.03 lnTL and as lnW= -4.59+3.0551 lnTL for females which shows a good feeding condition and a positive-isometric growth. Difference of length distribution between males and females is significant and males have lower lengths because this sex matures sooner so its growth is lower than females. Difference of fish length distribution between this study and previous studies on the C. capoeta gracilis of the river is significant and Lenkoran's length shows great decrease in this study as compared to previous studies. Age of the fishes ranged from 1 ^+ to 5 ^+ for males and 2 ^+ to 8 ^+ for females, the dominant age was 2 ^+ and the mean age was calculated as 2.009 ±0.034. We found that C. capoeta gracilis population had become younger in this study, so we concluded that the floods had made great changes in age and length structure of the fish