1,720,956 research outputs found
การพัฒนาและประเมินผลเครื่องอบแห้งแบบปั๊มความร้อนขนาดเล็กสำหรับกล้วยน้ำว้าสไลด์
Get PDFวารสารวิชาการและวิจัย มทร.พระนคร, ปีที่ 15, ฉบับที่ 1 (ม.ค.-มิ.ย. 2564), หน้า 179-192The purposes of this research were to develop and to test performance of mini heat pump dryer
for slice banana. Drying chamber of 0.48×0.47×0.39 m3 was designed and it could contain three trays. The three trays had dimension of 0.33×0.409 m2. A blower with 174.6 W motor of air condition was modify and could adjust flow rates of three levels for air cycle system in dryer. The air system had bypass air at evaporator. The refrigerant of R-134a and four main parts were used in the heat pump system. The four main parts were a 497 W hermetic compressor, a 1,800 W condenser, an expansion valve and a 1,300 W evaporator. Experiments for test performance of the mini heat pump dryer used close loop air system, an evaporator bypass air of 60 %, a temperature of 60 oC and various flow rates of 0.117, 0.128 and 0.140 m3/s. Slide bananas of 400-500 g had an initial moisture content of 244-281 %dry basis and were dried until final moisture content lower than 6.24±0.007 %dry basis. It was found that the flow rates of 0.117, 0.128 and 0.140 m3/s had coefficients of performance (COPh) of 3.32±0.066, 3.88±0.031 and 4.24±0.08, respectively and had specific moisture extraction rates (SMER) of 184.5±11.85, 186.2±8.17 and 200.1±21.34 g/kWh, respectively. The flow rate at 0.140 m3/s was the best condition because it had high specific moisture extraction rate.Rajamangala University of Technology Phra Nakho
Comparative Performance of Updraft-Gasified Gas Yields and Gasoline Fuel for Water Pumping
No full textAbstractThis research study investigates the performance of an updraft gasifier for a water pump powered by a small engine. The main components of the system are a 0.0793 m3 updraft gasifier, a cooling coil tube, a 0.050 m3 gas tank and a gas mixer. The proposed gasifier system is modified to prevent corrosion by covering the inside of the steel gasifier cover with fireproof cement. A HONDA GX120 gasoline engine and a water pump (MOKRO MK39 model) are used. Dried wood (5kg), charcoal (5kg) and gasoline are fuels in the experiments. The experiments are to identify a suitable fuel used with and without the gasifier in terms of the shortest time required to pump 5-liter water from a suction tank to a discharge tank with a water head of 13 m. The engine speed to drive the water pump is maintained at approximately 2500rpm. The engine speeds, the lengths of time to pump out 5-liter water and the fuel consumption are observed and documented. The flow rates of the dried wood, charcoal and gasoline under study are respectively 0.000134±2.4x 10-6, 0.000130±4.21 x 10-7 and 0.00017±4.22 x10-7 m3/s, while their respective power of fluid flow are 17.1±0.35, 16.7±0.54 and 22.01±0.05W. Their specific energy consumption levels are 0.45±0.0081, 0.46±0.0151and 0.0180±0.000045MJ/liter, respectively
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Modified Compression Ratio Effect on Brake Power of Single Piston Gasoline Engine Utilizing Producer Gas
No full textAbstractAn objective of this research is to test the brake power of Honda Model GX-120-four strokes-spark ignited engine. The producer gas was made from dry wood by the gasification process. The producer gas was used as a fuel for the engine. To study the effect of compression ratio and percentage of opened air inlet valve on break power, the compression ratio of 7.5:1 and 9.3:1 and percentage of opened air inlet valve of 30% and 75% were used. It was found that the brake power of compression ratio at 9.3:1 with 75% of opened air inlet valve was 1,443.6 Watts at 3,800rpm showed the highest break engine power because the high compression ratio was high, and the brake power was also high as the basic theory of an ideal Otto cycle
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Modified Hot Air Dryer by Leaf Stove for Banana Drying
No full textAbstractIn this paper, a modified hot air dryer by using leaf stove (MHAD_LS) was proposed for banana drying. The objectives of this research were to evaluate the efficiency of the leaf stove and the performance of MHAD_LS. The MHAD_LS system consisted of a drying chamber, heat exchanger in dryer, leaf stove and control system for using the speed adjustment on leaf feed motor and air feed motor to serve the thermal load. There were two experiments in this work. The first experiment was used to test the efficiency of the stove. It was found that the system efficiency was 18.68%. And the second experiment was used to find the performance of MHAD_LS which was performed in a partial-loop dryer at a drying air temperature and air velocity of 60 oC and 0.65 ms-1 respectively. The recycle air ratio was 90%. It was found that the product capacity of 30kg with the initial moisture at 250.10%dry basis and the resulting final moisture at 63%dry basis used time 22hours. The leaf amount of Indian almond for using in the experiment was 44.96kg, the total electric power consumption was 3.64 kWh and an average drying rate was 0.73 kgwater h-1
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