1,983 research outputs found

    TEMPERATURE-DEPENDENT PHYSICAL CHARACTERISTICS OF THE ROTATING NONLOCAL NANOBEAMS SUBJECT TO A VARYING HEAT SOURCE AND A DYNAMIC LOAD

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    In this article, the influence of thermal conductivity on the dynamics of a rotating nanobeam is established in the context of nonlocal thermoelasticity theory. To this end, the governing equations are derived using generalized heat conduction including phase lags on the basis of the Euler–Bernoulli beam theory. The thermal conductivity of the proposed model linearly changes with temperature and the considered nanobeam is excited with a variable harmonic heat source and exposed to a time-dependent load with exponential decay. The analytic solutions for bending moment, deflection and temperature of rotating nonlocal nanobeams are achieved by means of the Laplace transform procedure. A qualitative study is conducted to justify the soundness of the present analysis while the impact of nonlocal parameter and varying heat source are discussed in detail. It also shows the way in which the variations of physical properties due to temperature changes affect the static and dynamic behavior of rotating nanobeams. It is found that the physical fields strongly depend on the nonlocal parameter, the change of the thermal conductivity, rotation speed and the mechanical loads and, therefore, it is not possible to neglect their effects on the manufacturing process of precise/intelligent machines and devices

    Military Spending and Inequality: Panel Granger Causality Test

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    The relationship between military spending and economic inequality is not well documented within the empirical literature, while numerous studies have uncovered the linkages between military spending and other macroeconomic variables, such as economic growth, unemployment, purchasing power parity, black market premium, poverty and investment. The purpose of this article is to examine the causal relationship between military spending and inequality using BVC and SIPRI data across 58 countries from 1987 to 1999. Panel unit root tests indicate that two inequality measures (Theil and EHII) under consideration are likely to be non-stationary. The authors' work addresses the adverse implications of modeling with non-stationary variables, since this omission casts serious doubt on the reliability of the relationship between military spending and inequality. The recent developed panel Granger non-causality tests provide no evidence to support the causal relationship in either direction between the military spending and the change in economic inequality. The results are consistently robust to alternative data sources for military spending, to alternative definitions of the inequality measures, to the log transformation of the military spending, to the deletion of some data points, and to the division of OECD and non-OECD countries. Finally, the impulse responses and variance decompositions based on the panel vector autoregressive regression model are consistent with the findings relied on Granger non-causality tests

    Differentiation of frog fats from vegetable and marine oils by Fourier Transform Infrared Spectroscopy and chemometric analysis

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    The agro-based production and consumption of frogs coupled with world-wide trading have been increased in the recent years giving rise to the risk of frog fat adulteration in expensive vegetable and marine oils. For the first time, we profiled here frog fats using Fourier Transform Infrared (FTIR) Spectroscopy coupled with multivariate principal component analysis (PCA). The comparison of the FTIR spectral absorbance intensities demonstrated linkage of frog fats to other edible fats and oils. Three commercially available marine oils and three vegetables oils were studied with frog fats and clear pattern of clusters with distinctive identifiable features were obtained through PCA modeling. PCA analysis identified 2922.21 cm-1, 2852.88 cm-1, 1745.45 cm-1, 1158.29 cm-1 and 721.51 cm-1 FTIR-frequencies as the most discriminating variables influencing the group separation into different clusters. This fundamental study has clear implications in the identification of frog fat from its marine and vegetable counterparts for the potential detection of frog fat adulteration in various fat and oils

    Parámetros sedimentarios y texturales de continuidad y características mineralógicas del río Jajrood, Irán

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    In this research, we try to study the sedimentary characteristics and the trend of textural changes in the sediments of the Jajrood River from upstream to downstream at the point of junction to Latiyan dam. Based on the textural changes of sediments along the path from the upstream in the Garmabdar area to the downstream to the Latiyan Dam, the Jajrood River is divided into four A, B, C and D basins. Twenty sediment samples were collected and all sieved by dry and wet method also the specimens were morphoscopically studied. Data from field and laboratory phases were combined and interpreted using reliable scientific sources and finally a detailed summary was obtained regarding sedimentology of the study area. Mineralogically, the sediment type of the river is a clastic carbonate sedimentary type with fragments ranging from 30 to 58 percent and rock fragments between 25 to 50 percent abundance. Other minerals, such as feldspar minerals, account for about 1 to 4 percent, quartz 5 to 10 percent, and opauqe minerals from 1 to 5 percent. Examination of the average particle size in the A to D basins shows that decreasing trend of sediment size from the A to C basin occurs and reverses in the D basin. In the first three basins, the sorting grade of the river sediments is very bad and in the last basin it has become extremely bad. The amount of kurtosis of the particle distribution curve from upstream to downstream of the river is generally increasing trend. Textural changes along the river do not follow natural conditions due to the influence of various natural factors such as the entry of distributary into the main River, and phenomena such as landslide and rock collapses and debris flows, especially during floods along the riverbank.En esta investigación, tratamos de estudiar las características sedimentarias y la tendencia de los cambios de textura en los sedimentos del río Jajrood desde aguas arriba hacia aguas abajo en el punto de unión con la presa de Latiyan. Basado en los cambios de textura de los sedimentos a lo largo del camino desde el río arriba en el área de Garmabdar hasta la presa de Latiyan, el río Jajrood se divide en cuatro cuencas A, B, C y D. Se recogieron veinte muestras de sedimentos y todas se tamizaron por método seco y húmedo, y las muestras se estudiaron morfoscópicamente. Los datos de las fases de campo y laboratorio se combinaron e interpretaron utilizando fuentes científicas confiables y finalmente se obtuvo un resumen detallado sobre la sedimentología del área de estudio. Desde el punto de vista mineralógico, el tipo de sedimento del río es un tipo sedimentario de carbonato clástico con fragmentos que van del 30 al 58 por ciento y fragmentos de roca entre el 25 y el 50 por ciento de abundancia. Otros minerales, como los minerales de feldespato, representan alrededor del 1 al 4 por ciento, los cuarzos del 5 al 10 por ciento y los minerales opacos del 1 al 5 por ciento. El examen del tamaño promedio de partícula en las cuencas A a D muestra que se produce una tendencia decreciente del tamaño del sedimento de la cuenca A a C y se invierte en la cuenca D. En las primeras tres cuencas, el grado de clasificación de los sedimentos del río es muy malo y en la última cuenca se ha vuelto extremadamente malo. La cantidad de curtosis de la curva de distribución de partículas de río arriba a río abajo es generalmente una tendencia creciente. Los cambios de textura a lo largo del río no siguen las condiciones naturales debido a la influencia de varios factores naturales, como la entrada de distribución en el río principal, y fenómenos como derrumbes y derrumbes de rocas y flujos de escombros, especialmente durante las inundaciones a lo largo de la orilla del río

    Parámetros sedimentarios y texturales de continuidad y características mineralógicas del río Jajrood, Irán

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    In this research, we try to study the sedimentary characteristics and the trend of textural changes in the sediments of the Jajrood River from upstream to downstream at the point of junction to Latiyan dam. Based on the textural changes of sediments along the path from the upstream in the Garmabdar area to the downstream to the Latiyan Dam, the Jajrood River is divided into four A, B, C and D basins. Twenty sediment samples were collected and all sieved by dry and wet method also the specimens were morphoscopically studied. Data from field and laboratory phases were combined and interpreted using reliable scientific sources and finally a detailed summary was obtained regarding sedimentology of the study area. Mineralogically, the sediment type of the river is a clastic carbonate sedimentary type with fragments ranging from 30 to 58 percent and rock fragments between 25 to 50 percent abundance. Other minerals, such as feldspar minerals, account for about 1 to 4 percent, quartz 5 to 10 percent, and opauqe minerals from 1 to 5 percent. Examination of the average particle size in the A to D basins shows that decreasing trend of sediment size from the A to C basin occurs and reverses in the D basin. In the first three basins, the sorting grade of the river sediments is very bad and in the last basin it has become extremely bad. The amount of kurtosis of the particle distribution curve from upstream to downstream of the river is generally increasing trend. Textural changes along the river do not follow natural conditions due to the influence of various natural factors such as the entry of distributary into the main River, and phenomena such as landslide and rock collapses and debris flows, especially during floods along the riverbank.En esta investigación, tratamos de estudiar las características sedimentarias y la tendencia de los cambios de textura en los sedimentos del río Jajrood desde aguas arriba hacia aguas abajo en el punto de unión con la presa de Latiyan. Basado en los cambios de textura de los sedimentos a lo largo del camino desde el río arriba en el área de Garmabdar hasta la presa de Latiyan, el río Jajrood se divide en cuatro cuencas A, B, C y D. Se recogieron veinte muestras de sedimentos y todas se tamizaron por método seco y húmedo, y las muestras se estudiaron morfoscópicamente. Los datos de las fases de campo y laboratorio se combinaron e interpretaron utilizando fuentes científicas confiables y finalmente se obtuvo un resumen detallado sobre la sedimentología del área de estudio. Desde el punto de vista mineralógico, el tipo de sedimento del río es un tipo sedimentario de carbonato clástico con fragmentos que van del 30 al 58 por ciento y fragmentos de roca entre el 25 y el 50 por ciento de abundancia. Otros minerales, como los minerales de feldespato, representan alrededor del 1 al 4 por ciento, los cuarzos del 5 al 10 por ciento y los minerales opacos del 1 al 5 por ciento. El examen del tamaño promedio de partícula en las cuencas A a D muestra que se produce una tendencia decreciente del tamaño del sedimento de la cuenca A a C y se invierte en la cuenca D. En las primeras tres cuencas, el grado de clasificación de los sedimentos del río es muy malo y en la última cuenca se ha vuelto extremadamente malo. La cantidad de curtosis de la curva de distribución de partículas de río arriba a río abajo es generalmente una tendencia creciente. Los cambios de textura a lo largo del río no siguen las condiciones naturales debido a la influencia de varios factores naturales, como la entrada de distribución en el río principal, y fenómenos como derrumbes y derrumbes de rocas y flujos de escombros, especialmente durante las inundaciones a lo largo de la orilla del río

    Mathematical Model for the Temperature Distribution on The Surface of Two Aluminum Alloys Welded by Friction Stir Welding

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    The aim of this study was to predict the temperatures on all surfaces of three-dimensional models using the ANSYS 15.0 program. Firstly, the temperatures from the welding centre to the edges of the models of two aluminium alloys (AA-7075 & AA-2024) welded by friction stir welding process were perceived. Secondly, the distribution of temperatures from the start of the welding process to its end and the derivation of equations to predict the distribution of temperatures with the time spent in the welding process, along with the distribution of temperatures with the distance from the centre of the welding process were observed at different travel speeds of the welding cart (TS = 20, 40, 60, 100 mm/sec) and different speeds of the welding tool (TRS=900, 1050, 1200 rpm). The results indicate that the temperature increases with the increase in the rotational speed of the welding tool, while the temperature decreases with the increase in the travel speed of the welding cart. Another result is that the temperature distribution is not symmetrical. The highest values are in the welding centre and decrease significantly as the welding centre is moved away, and the highest temperatures can be reached between (75 – 80%) in the welding centre from the melting point of the two aluminium alloys welded together. It was also found that the temperatures increase significantly twenty seconds after the beginning of the welding process and, afterwards, the increase is small, and three equations were derived to predict the temperature distribution

    Comparison of low versus high (standard) intraabdominal pressure during laparoscopic colorectal surgery:systematic review and meta-analysis

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    Background: To evaluate outcomes of low with high intraabdominal pressure during laparoscopic colorectal resection surgery. Methods: A systematic search of multiple electronic data sources was conducted, and all studies comparing low with high (standard) intraabdominal pressures were included. Our primary outcomes were post-operative ileus occurrence and return of bowel movement/flatus. The evaluated secondary outcomes included: total operative time, post-operative haemorrhage, anastomotic leak, pneumonia, surgical site infection, overall post-operative complications (categorised by Clavien-Dindo grading), and length of hospital stay. Revman 5.4 was used for data analysis. Results: Six randomised controlled trials (RCTs) and one observational study with a total of 771 patients (370 surgery at low intraabdominal pressure and 401 at high pressures) were included. There was no statistically significant difference in all the measured outcomes; post-operative ileus [OR 0.80; CI (0.42, 1.52), P = 0.50], time-to-pass flatus [OR -4.31; CI (-12.12, 3.50), P = 0.28], total operative time [OR 0.40; CI (-10.19, 11.00), P = 0.94], post-operative haemorrhage [OR 1.51; CI (0.41, 5.58, P = 0.53], anastomotic leak [OR 1.14; CI (0.26, 4.91), P = 0.86], pneumonia [OR 1.15; CI (0.22, 6.09), P = 0.87], SSI [OR 0.69; CI (0.19, 2.47), P = 0.57], overall post-operative complications [OR 0.82; CI (0.52, 1.30), P = 0.40], Clavien-Dindo grade ≥ 3 [OR 1.27; CI (0.59, 2.77), P = 0.54], and length of hospital stay [OR -0.68; CI (-1.61, 0.24), P = 0.15]. Conclusion: Low intraabdominal pressure is safe and feasible approach to laparoscopic colorectal resection surgery with non-inferior outcomes to standard or high pressures. More robust and well-powered RCTs are needed to consolidate the potential benefits of low over high pressure intra-abdominal surgery

    Comparative Study Using WEKA for Red Blood Cells Classification

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    Red blood cells (RBC) are the most common types of blood cells and are the most intensively studied in cell biology. The lack of RBCs is a condition in which the amount of hemoglobin level is lower than normal and is referred to as "anemia". Abnormalities in RBCs will affect the exchange of oxygen. This paper presents a comparative study for various techniques for classifying the RBCs as normal, or abnormal (anemic) using WEKA. WEKA is an open source consists of different machine learning algorithms for data mining applications. The algorithm tested are Radial Basis Function neural network, Support vector machine, and K-Nearest Neighbors algorithm. Two sets of combined features were utilized for classification of blood cells images. The first set, exclusively consist of geometrical features, was used to identify whether the tested blood cell has a spherical shape or non-spherical cells. While the second set, consist mainly of textural features was used to recognize the types of the spherical cells. We have provided an evaluation based on applying these classification methods to our RBCs image dataset which were obtained from Serdang Hospital-alaysia, and measuring the accuracy of test results. The best achieved classification rates are 97%, 98%, and 79% for Support vector machines, Radial Basis Function neural network, and K-Nearest Neighbors algorithm respectively

    Botanicals to Control Soft Rot Bacteria of Potato

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    Extracts from eleven different plant species such as jute (Corchorus capsularis L.), cheerota (Swertia chiraita Ham.), chatim (Alstonia scholaris L.), mander (Erythrina variegata), bael (Aegle marmelos L.), marigold (Tagetes erecta), onion (Allium cepa), garlic (Allium sativum L.), neem (Azadiracta indica), lime (Citrus aurantifolia), and turmeric (Curcuma longa L.) were tested for antibacterial activity against potato soft rot bacteria, E. carotovora subsp. carotovora (Ecc) P-138, under in vitro and storage conditions. Previously, Ecc P-138 was identified as the most aggressive soft rot bacterium in Bangladeshi potatoes. Of the 11 different plant extracts, only extracts from dried jute leaves and cheerota significantly inhibited growth of Ecc P-138 in vitro. Finally, both plant extracts were tested to control the soft rot disease of potato tuber under storage conditions. In a 22-week storage condition, the treated potatoes were significantly more protected against the soft rot infection than those of untreated samples in terms of infection rate and weight loss. The jute leaf extracts showed more pronounced inhibitory effects on Ecc-138 growth both in in vitro and storage experiments
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