14,049 research outputs found
Free-convection condensation on single horizontal pin-fin tubes
No full textPhDNew experimental data are reported for free-convection condensation of ethylene
glycol and R-113 on three-dimensional pin-fin tubes. Effects of pin geometry and tube
thermal conductivity (for copper, brass and bronze giving a mean range of 400, 120 and
80 W/m K over the range of temperature of interest) were investigated. All tests were
performed at near atmospheric pressure with downward flowing vapour at low velocity.
Heat-transfer enhancement was found to be approximately twice the corresponding
active surface area of the tubes, i.e. the surface area of the parts of the tube and pin
surface not covered by condensate retained by surface tension. For ethylene glycol, the
best performing pin-fin tube gave a heat-transfer enhancement of 5.8, about 24 %
higher than the ‘equivalent’ two-dimensional integral-fin tube (i.e. with the same finroot
diameter, longitudinal fin spacing and thickness and fin height). For R-113, the
best enhancement was 5.9, about 10 % higher than the equivalent integral-fin tube.
For both fluids tested, vapour-side, heat-transfer enhancement was found to increase
with decreasing circumferential pin spacing and increasing pin height. Circumferential
pin thickness had little effect on heat-transfer enhancement. Effects of tube thermal
conductivity were found to be more significant for ethylene glycol than R-113.
Retention angle measurements were made under static conditions (without
condensation) and were found to be larger than for equivalent integral-fin tubes. An
expression for condensate retention angle on pin-fin tubes was proposed and found to
agree with the measured retention angles to ±15%.
A semi-empirical model for condensation heat transfer on horizontal pin-fin tubes has
been developed which accounts for the combined effect of gravity and surface tension.
The model predicts the majority of available data to ±20 %
Lagu maktab [College song]
No full textThe Teachers’ Training College (TTC) song was first sung at the TTC Graduation on 4 November 1967. Leong Yoon Pin and Muhammad Ariff Ahmad were lecturers of TTC
“Crimson Crest”, “Golden Song” and “Little Blue”
No full textThe three wearable sculptural artworks “Crimson Crest”, “Golden Song” and “Little Blue” that were selected by ANCA gallery directors for exhibition in the national group exhibition PIN 7, were an investigation into the concept of the physical “wearing of identity” as a performance of selfhood, through different artistic strategies and the use of symbolism invested into ornamentation, and the concept of embellishment as an elaboration of self
Establishment of Ecological Engineering Method Retaining Wall by Using Thinning Timbers.
No full textThe Consciousness of Nation in Wang Song\ue2s poetry
No full textAlthough modern Taiwanese literature is emphasized in recent years, there are few dissertations about classic Taiwanese literature. In this dissertation, the author tries to explore into the national consciousness presented in Wang Song\ue2s poetry. Wang Song is a classic poet in Taiwan when the Japanese were ruling Taiwan. Therefore, he has to present his national consciousness implicitly in his poetry. The author tries to explain his national consciousness through the three stages of Wang Song\ue2s life. This is because his poetry is deeply related with his life experience. The readers can observe Wang Song\ue2s paradoxical emotion in his poetry. This paradoxical emotion results from his national consciousness. Wang Song grew up in a traditional chinese family and he believes he is a Chinese. This is why he can\ue2t accept the Japanese government. Through the discussion of Wang Song\ue2s national consciousness, we can understand his motive of creation and the real meaning of his poetry.
The second chapter introduces Wang Song\ue2s life and his work. The third chapter brings in the creative style of the classic Taiwanese society which Wang Song lived in. The forth chapter talks about Wang Song\ue2s creative style and his theory of creation. The fifth and sixth chapter are the analysis of the national consciousness in Wang Song\ue2s poetry. Although Wang Song\ue2s poetry are not as good as the other poets in the classic Chinese literature, his work shows the national consciousness when he survives in a colonialized society. Through the reading of his poetry, the author offers a way to understand the Taiwanese literary work during the Japanese colonializaiton
Author Identification from Song Lyrics
No full textMachine Learning (ML) tools have been used extensively in a wide variety of domains
recently. Due the enormous amount of data being produced, machine learning techniques
are being heavily used to make sense of data & derive meaningful results. Using machine
learning tools, we can turn the data into knowledge.
Music is one of the truest forms of art. Bangladesh has a great history of music with a
great tradition of song writing over centuries. Authorship attribution is the way of
identifying the author from a linguistic corpus.
This paper demonstrates a guideline to identify the author of a Bengali song from the
lyrics of that song using machine learning. This research work presents the first work on
machine learning approach for author attribution from the lyrics of a song. Here six
methods of machine learning are used for the author identification and high accuracies
have been achieved from these methods. It is observed that Naïve Bayes method provides
higher accuracy in comparison with the other methods
Optimization of Pin-Fins for a Heat Exchanger by Entropy Generation Minimization and Constructal Law
No full textP.O. Box 552, Xi’an 710072, Shaanxi, China
Masoud Asadi
Department of Mechanical Engineering, Azad Islamic University Science and Research Branch, Tehran 1615918683, Iran e-mail: [email protected]
Giulio Lorenzini
Full Professor Department of Industrial Engineering, University of Parma, Parco Area delle Scienze, 181A, Parma 43124, Italy
1 Introduction
Employing pin-fins on a heated surface promotes heat transfer performance. Given their inexpensive and simple structure, pin- fins have extensive applications in cooling ranges from electronic equipment to the automobile industry. In diesel engines, about two-thirds of the input energy is wasted through the exhaust gas and cooling water. In this sense, it is important that a serious effort should be launched for conserving this energy. A pin-fin heat exchanger is an excellent choice for recovering waste energy in an automobile with diesel engine. Traditional methods for design- ing the exchanger are not very applicable because of relatively high pressure drop. Effective optimization methods are therefore necessary to enhance heat transfer performance with low pressure drop. Although there exist various methods for optimization of designs of heat exchangers, such optimizations were considered as manual designs by using different optimization algorithm rather than based on nature design from the standpoint of thermodynam- ics. This study focuses on the optimization of pin-fin geometry for a new heat exchanger by using EGM and CL.
EGM is widely used to evaluate thermal and energy systems in view of thermodynamic imperfection [1,2]. For example, Saffari- pour and Culham [3] presented a new nonintrusive method for the measurement of entropy production in microscale thermal-fluid devices. The entropy generation map was also obtained by post- processing the velocity and temperature distribution data. They used microparticle image velocimetry and laser-induced fluores- cence methods to measure data. Li and Kleinstreuer [4] analyzed the entropy generation in trapezoidal microchannels. They found that there existed an optimal Reynolds number range in order to
1Corresponding author.
Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received March 22, 2014; final manuscript received June 25, 2014; published online March 17, 2015. Assoc. Editor: Cesare Biserni.
Optimization of Pin-Fins for a Heat Exchanger by Entropy Generation Minimization and Constructal Law
Pin-fins are considered as one of the best elements for heat transfer enhancement in heat exchangers. In this study, the topology of pin-fins (length, diameter, and shape) is opti- mized based on the entropy generation minimization (EGM) theory coupled with the con- structal law (CL). Such pin-fins are employed in a heat exchanger in a sensible thermal energy storage (TES) system so as to enhance the rate of heat transfer. First, the EGM method is used to obtain the optimal length of pin-fins, and then the CL is applied to get the optimal diameter and shape of pin-fins. Reliable computational fluid dynamics (CFD) simulations of various constructal pin-fin models are performed, and detailed flow and heat transfer characteristics are presented. The results show that by using the proposed system with optimized pin-fin heat exchanger the stored thermal energy can be increased by 10.2%
Song
No full textAuthor attribution from Rudolph, 240. Printed on yellow paper with black ink. Set to the tune of "Happy land of Canaan". First line "You Rebels come along and listen to my song"
The Singer or the Song? Developments in Performers' Rights from the Perspective of a Cultural Economist
No full textOver the last century, performers gradually acquired statutory protection of their economic and moral
rights. These rights are not copyright in the legal sense but neighboring rights and until recently, they
were mainly remuneration rights that are collectively administered. With the WPPT (WIPO
Performers and Phonograms Treaty), performers now have individual exclusive rights for digital
performances; this leads to the question: what has motivated this change – is it a change in the
perception of the value of performer or a change brought about by the changing technology of copying or,
indeed, a change that reflects different economic costs and benefits? The paper discusses the role of
copyright law as an incentive to performers and asks if the economic role of the performer is so different
from that of the author. The conclusion is that a complex interaction of the legal regulations, economic
conditions and institutional arrangements for administering these new rights will determine the outcome
Characterisation of monoclonal antibodies to haemocyte subpopulations of tiger shrimp (Penaeus monodon): immunochemical differentiation of three major haemocyte types
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