Casimir effect in a weak gravitational field and the spacetime index of refraction

In a recent paper [arXiv:0904.2904] using a conjecture it is shown how one can calculate the effect of a weak stationary gravitational field on vacuum energy in the context of Casimir effect in an external gravitational field treated in 1+3 formulation of spacetime decomposition.. In this article, employing quntum field theory in curved spacetime, we explicitly calculate the effect of a weak static gravitational field on virtual massless scalar particles in a Casimir apparatus. It is shown that, as expected from the proposed conjecture, both the frequency and renormalized energy of the virtual scalar field are affected by the gravitational field through its index of refraction. This could be taken as a strong evidence in favour of the proposed conjecture. Generalizations to weak {\it stationary} spacetimes and virtual photons are also discussed.Comment: 11 pages, RevTex, typos corrected (combined with arXiv:0904.2904 published in PRD

Predicting compressive strength of different geopolymers by artificial neural networks

In the present study,six different models based on artificial neural networks have been developed to predict the compressive strength of different types of geopolymers.The differences between the models were in the number of neurons in hidden layers and in the method of finalizing the models.Seven independent input parameters that cover the curing time,Ca(OH)2 content, the amount of superplasticizer, NaOH concentration,mold type,geopolymer type and H2O/Na2O molar ratio were considered.For each set of these input variables,the compressive strength of geopolymers was obtained.A total number of 399 input-target pairs were collected from the literature, randomly divided into 279,60 and 60data and were trained,validated and tested, respectively. The best performance model was obtained through a network with two hidden layers and absolute fraction of variance of 0.9916, the absolute percentage error of 2.2102 and the root mean square error of 1.4867 in training phase. Additionally,the entire trained,validated and tested network showed a strong potential for predicting the compressives trength of geopolymers with a reasonable performance in the considered range

The dual of z-submodules of modules and some of extensions

Let R be a commutative ring with identity and M be an R-module. The purpose of this paper is to introduced the dual notion of z-submodules of M and some of extensions. Moreover, we investigate some properties of these classes of modules when M is a coreduced comultiplication R-module

Evaluation of emerging Fusarium mycotoxins beauvericin, enniatins, fusaproliferin and moniliformin in domestic rice in Iran

The occurrence of emerging Fusarium mycotoxins beauvericin (BEA), enniatins (ENNs) (A, A1, B, B1), Fusaproliferin and moniliformin was evaluated by a liquid chromatography/ electrospray ionization-tandem mass spectrometric (LC/ESI-MS/MS) technique in 65 domestic rice samples produced in Gilan and Mazandaran Provinces in Iran. The results showed that 46 of the samples were contaminated with at least one of the emerging mycotoxins. BEA was the most prevalent mycotoxin, which was found in 26 out of 65 rice samples at the concentrations up to 0.47 µg/Kg. Enniatin A1 which was the only member of ENNs was detected in the samples, occurred in 7.7 of samples with an average level of 0.06 μg/Kg. No detectable level of Fusaproliferin and moniliformin was found. This is the first report concerning the contamination of Iranian domestic rice samples with the emerging Fusarium mycotoxins. © 2015 by School of Pharmac

Simultaneous Determination of Nitrite and Nitrate in Milk Samples by Ion Chromatography Method and Estimation of Dietary Intake

The presence of nitrate and nitrite in foods may be considered hazardous after ingestion in the gastrointestinal tract due to their reaction with naturally occurred secondary amines to form potentially carcinogenic nitrosamines. Due to this fact, a new method was developed in this study for the simultaneous determination of nitrite and nitrate in milk samples using by ion chromatography. Proposed mobile phase composed of sodium hydrogen carbonate and sodium carbonate (1.0 and 3.2 mmol/L) with a flow rate of 0.7 ml/min. The average recoveries for nitrate and nitrite were higher than 86 and 88, respectively. The limit of detection for nitrate and nitrite were 0.24 and 0.09 mg/L, respectively. The results of 102 real milk samples showed nitrate was found in all of the samples (100) with a mean of 34 ± 11 mg/L, while nitrite was found in none of the samples. The mean intake of nitrate in all age groups was lower than World Health Organization guideline. The present assessment concludes that the maximum contaminant level was equal to 82.8 mg/L nitrate. This method was fast, sensitive and accurate and is capable of being an alternative method in food control laboratories for investigation of nitrite and nitrate content. This is the first study of the determination and survey of nitrite and nitrate and exposure assessment of the Iranian population to nitrite and nitrate level in milk, which was widely used in infants and adolescents as one of the basic food components. Copyright © Taylor & Francis Group, LLC

Evaluation of preoperative anxiety and stress, and ways to modify it, the patients in Kashani hospital operating room in 2013

زمینه و هدف: با وجودی که در عصر حاضر بی هوشی و جراحی نسبت به گذشته کم عارضه تر و موفقیت آمیز تر شده است، ولی اضطراب قبل از عمل جراحی همچنان به قوت خود باقی است. اضطراب نوعی تشویش و نگرانی است که به دنبال وجود نوعی احساس تهدید یا خطر در فرد ایجاد می شود و می تواند در کاهش یا افزایش توانایی درک فرد، موثر باشد. این مطالعه با هدف ارزیابی عوامل اضطراب و استرس قبل از عمل جراحی و راه های تعدیل آن در بیماران جراحی شده انجام شده است. روش بررسی: این مطالعه ی توصیفی در سال 1392 بر روی 120 بیمار جراحی شده در اتاق عمل بیمارستان کاشانی شهرکرد انجام گرفت. افراد به روش تصادفی سیستماتیک انتخاب شدند. جهت سنجش اضطراب، از پرسشنامه محقق ساخته استفاده شد. یافته ها: بیشترین میزان اضطراب مربوط به نگرانی های قبل از عمل جراحی (13/15)، عوامل تنش زا و مراقبت انجام شده در بخش (12/19)، عوامل تنش زا در رابطه با کارکنان اتاق عمل (10/35) و عوامل تنیدگی آور محیط فیزیکی اتاق عمل (7/26) بوده است. نتیجه گیری: یافته های نهایی این پژوهش حاکی از آن است که با شناسایی عوامل مؤثر بر اضطراب قبل از عمل و رفع آن ها می توان میزان اضطراب قبل از عمل را به حداقل رساند؛ لذا پیشنهاد می گردد با به کارگیری روش های متنوع جهت آموزش بیماران و مشخص کردن برنامه مدون آموزشی در جهت رفع عوامل موثر بر اضطراب اقدام گردد

Effect of the timing of initial feeding on growth and survival of Persian sturgeon (Acipenser persicus) larvae

Effect of the timing of first feeding (9, 10, 11, 12 and 13 days post hatch) with a live food (Artemia naupli) on Persian sturgeon was examined at 17.7±0.8 and 18.1±0.4°C. The results showed that the timing of first feeding affected on weight, length, length-weight ratio and specific growth rate, but one day delay in the timing of initial feeding doesn't affect on the survival and two days delay in the timing of initial feeding doesn't affect on the condition factor. Results of this research showed that some factors such as weight, length, length-weight ratio and specific growth rate, are more suitable than survival and condition factor for exhibiting of effects of delay in the starting time of initial feeding in Persian sturgeon fish larvae. Thus it is better that the initial feeding of Persian sturgeon at 17.7±0.8 and 18.1 ±0.4°C started on 12 and 9 days after hatching, respectively, as well as more delay in initiating exogenous feeding has negative effects on growth of larvae

Seroprevalence of human T-cell lymphotropic virus type 1 infection (HTLV1) in different patients in the north of Iran

Human T-cell lymphotropic virus type-1 (HTLV1) is a lymphotropic virus which can contribute to carcinogenesis in adult T-cell leukemia, myleopathy and other disorders. 20 million people are affected by this virus in the world. The aim of this study was to determine the incidence of human T-cell lymph tropic virus type 1 infection in patients referred to Emam’s hospital laboratory in Sari. A cross-sectional study was done in 2009 to 2010 based on the different patients that were referred to Emam`s hospital laboratory in Sari. Our samples were selected by simple random selection, after venous blood sample was centrifuged and reserved in -70°C. All the samples were tested by enzyme-linked immuno sorbent assay (ELISA). An ELISA positive result was checked by Western blot (WB) assays. Out of 1200 cases, 776 were female (65%) with ages between 1 and 76 years old. Most of the cases were Mazandaranian (99%); although only one person was recorded as HTLV1 positive (0.08%). He was a 41 years old man, living in Sari, with high school education. He was married (one wife) without any risk factor in past medical history, such as surgery, transfusion and abuse of injection, but he had HBV infection. Most of the females were housewives and most of the males were non-governmental employees; moreover, diabetes was more common among them. The results of the samples show that 122 women were pregnant, 92 cases had transfusion and 642 cases had different surgery. It was observed that the incidence of HTLV1 infection was very rare in the north of Iran (Sari); therefore, the routine HTLV1 screening was not recommended.Key words: Seroprevalence, human T-cell lymphotropic virus type-1 (HTLV1), patients, Iran