824 research outputs found
A new method for providing a model to analyze a kite wind turbine
The ultimate purpose of simulating kite wind turbine is to predict the kite movement and the power generated by its mechanism. To simulate because when the initial estimate of the intended values is found, we may have to manipulate the simulation to find the most efficient design for manufacturing our system and then predict the final power generated for our mechanism. Simulation for the system is based on two parts: Simulation of steady-state and dynamic model, which include differential equations. In this paper, we have presented a novel idea for a proper simulation of the system based on the two static and dynamic parts in order to numerical solution of the required amount and to calculate the output power.Keywords: Kite wind turbine; Simulation; Static model; Dynamic model;Winch; Torqu
Age, sex ratio, spawning season, gonadosomatic index, and fecundity of Cobitis faridpaki (Actinopterygii, Cobitidae) from the Siahrud River in the southeastern Caspian Sea basin
Cobitis faridpaki Cobitis faridpaki (Mousavi-Sabet, Vasil'eva, Vatandoust and Vasil'ev, 2011) is found in streams of the Siahrud River in the southeastern Caspian Sea basin, and this is the first report on reproductive parameters of the newly described endemic loach. Reproductive conditions are key parameters of fish populations, and their assessment is very important for endemic fishes. To study reproduction biology of this fish, sampling was done at monthly intervals throughout the year and 258 individuals of Cobitis faridpaki, were caught from Siahrud River in the southeastern Caspian Sea basin, in the north of Iran. Age, sex ratio, fecundity, oocytes diameter and gonadosomatic index were estimated. A regression analysis was used to find relationships between fecundity and fish size (length and weight), gonad weight and age. Sex ratio differed significantly from unity and was biased to females. The mature females and males were longer than 40 and 30 mm in total length, and +2 and +1 in age, respectively. The average egg diameter was 0.578 mm. Spawning took place from beginning of May to late July when water temperature was between 19.4 to 25.1 °C. Average GSI value at the beginning of the reproduction period was 9.12% and ranged between 2% to 20% in ripe mature females. The averages of absolute and relative fecundity were calculated as 1366 and 508, respectively. The absolute fecundity was significantly related to body weight and gonad weight. Based on the pattern of gonadosomatic index, it was concluded that this fish has a prolonged active reproduction period, which is a type of adaptation of short-lived small fishes to environmental conditions
Fibulin-2 is required for basement membrane integrity of mammary epithelium
Fibulin-2 (FBLN2) is a secreted extracellular matrix glycoprotein which has been associated with tissue development and remodelling. In the mouse mammary gland, FBLN2 can be detected during ductal morphogenesis in cap cells and myoepithelial cells at puberty and early pregnancy, respectively. In an attempt to assign its function, we knocked down Fbln2 in the mouse mammary epithelial cell line EpH4. FBLN2 reduction led to an increase in the size of spheroidal structures when compared to scrambled control shRNA-transduced cells plated on Matrigel matrix. This phenotype was associated with a disruption of the collagen IV sheath around the epithelial spheroids and downregulation of integrin β1, suggesting a role for FBLN2 in stabilizing the basement membrane (BM). In contrast to mice, in normal adult human breast tissue, FBLN2 was detected in ductal stroma, and in the interlobular stroma, but was not detectable within the lobular regions. In tissue sections of 65 breast cancers FBLN2 staining was lost around malignant cells with retained staining in the neighbouring histologically normal tissue margins. These results are consistent with a role of FBLN2 in mammary epithelial BM stability, and that its down-regulation in breast cancer is associated with loss of the BM and early invasion
Fibulin-2 is required for basement membrane integrity of mammary epithelium
Fibulin-2 (FBLN2) is a secreted extracellular matrix glycoprotein which has been associated with tissue development and remodelling. In the mouse mammary gland, FBLN2 can be detected during ductal morphogenesis in cap cells and myoepithelial cells at puberty and early pregnancy, respectively. In an attempt to assign its function, we knocked down Fbln2 in the mouse mammary epithelial cell line EpH4. FBLN2 reduction led to an increase in the size of spheroidal structures when compared to scrambled control shRNA-transduced cells plated on Matrigel matrix. This phenotype was associated with a disruption of the collagen IV sheath around the epithelial spheroids and downregulation of integrin β1, suggesting a role for FBLN2 in stabilizing the basement membrane (BM). In contrast to mice, in normal adult human breast tissue, FBLN2 was detected in ductal stroma, and in the interlobular stroma, but was not detectable within the lobular regions. In tissue sections of 65 breast cancers FBLN2 staining was lost around malignant cells with retained staining in the neighbouring histologically normal tissue margins. These results are consistent with a role of FBLN2 in mammary epithelial BM stability, and that its down-regulation in breast cancer is associated with loss of the BM and early invasion
Self-burning: A common and tragic way of suicide in fars province, Iran
Self-burning is the most devastating burn injury. It is a common social and medical problem in Iran. In a longitudinal prospective study, from April 2003 to March 2006, all burn patients admitted to Ghotb-eddin burn Hospital were enrolled in this study. Suicide attempts by burning accounted for 283 (21.9%) of all burn patients admitted to the hospital. Most (68.2%) of self-burning patients were female. Self-burn patients had significantly large burned body surface area (64.8±29%). Suicidal burns occurred predominantly in the age group 15-24 years (44.6%). The mortality rate for suicidal burns was (60.4%). Fars is a province composed of many different tribes and cultural minorities whereby major decisions are made by forums of clergymen. It is important to involve those clergymen in burn prevention programs to achieve a meaningful reduction in Self-burning prevalence
OL-009 Role of Giardia lamblia infection in the pathogenesis of gastritis in patients with dyspepsia in Upper Egypt
The Study of Cognitive Function and Related Factors in Patients With Heart Failure
Background: Cognitive impairment is increasingly recognized as a common adverse consequence of heart failure. Both Heart failure and cognitive impairment are associated with frequent hospitalization and increased mortality, particularly when they occur simultaneously.
Objectives: To determine cognitive function and related factors in patients with heart failure.
Materials and Methods: In this descriptive cross-sectional study, we assessed 239 patients with heart failure. Data were collected by Mini Mental status Examination, Charlson comorbidity index and NYHA classification system. Data were analyzed using descriptive statistics, Kolmogorov-Smirnov test, chi-square test, t-test and logistic regression analysis.
Results: The mean score of cognitive function was 21.68 ± 4.51. In total, 155 patients (64.9%) had cognitive impairment. Significant associations were found between the status of cognitive impairment and gender (P < 0.002), education level (P < 0.000), living location (P < 0.000), marital status (P < 0.03), living arrangement (P < 0.001 ), employment status (P < 0.000), income (P < 0.02), being the head of family (P < 0.03), the family size (P < 0.02), having a supplemental insurance (P < 0.003) and the patient’s comorbidities (P < 0.02). However, in logistic regression analysis, only education and supplementary insurance could predict cognitive status which indicates that patients with supplementary insurance and higher education levels were more likely to maintain optimal cognitive function.
Conclusions: More than a half of the subjects had cognitive impairment. As the level of patients cognitive functioning affects their behaviors and daily living activities, it is recommended that patients with heart failure should be assessed for their cognitive functioning
Solar Irradiance Anticipative Transformer
This paper proposes an anticipative transformer-based model for short-term solar irradiance forecasting. Given a sequence of sky images, our proposed vision transformer encodes features of consecutive images, feeding into a transformer decoder to predict irradiance values associated with future unseen sky images. We show that our model effectively learns to attend only to relevant features in images in order to forecast irradiance. Moreover, the proposed anticipative transformer captures long-range dependencies between sky images to achieve a forecasting skill of 21.45 % on a 15 minute ahead prediction for a newly introduced dataset of all-sky images when compared to a smart persistence model
Vision transformer models to measure solar irradiance using sky images in temperate climates
Solar Irradiance measurements are critical for a broad range of energy systems, including evaluating performance ratios of photovoltaic systems, as well as forecasting power generation. Using sky images to evaluate solar irradiance, allows for a low-cost, low-maintenance, and easy integration into Internet-of-things network, with minimal data loss. This work demonstrates that a vision transformer-based machine learning model can produce accurate irradiance estimates based on sky-images without any auxiliary data being used. The training data utilizes 17 years of global horizontal, diffuse and direct data, based on a high precision pyranometer and pyrheliometer sun-tracked system; in-conjunction with sky images from a standard lens and a fish-eye camera. The vision transformer-based model learns to attend to relevant features of the sky-images and to produce highly accurate estimates for both global horizontal irradiance (RMSE =52 W/m2) and diffuse irradiance (RMSE = 31 W/m2). This work compares the model's performance on wide field of view all-sky images as well as images from a standard camera and shows that the vision transformer model works best for all-sky images. For images from a normal camera both vision transformer and convolutional architectures perform similarly with the convolution-based architecture showing an advantage for direct irradiance with an RMSE of 155 W/m2
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