1,720,986 research outputs found
Energy efficiency ratio (eer) of novel air conditioning system on LPG fuelled vehicle: a lab-scale investigation
No full textAlternative fuels have become an effective solution to reduce the impact of road transport on the environment. On the other hand, the growing uses of air-conditioning (AC) have contributed to worsening the fuel economy of passenger vehicles. Liquid petroleum gas (LPG), if injected in the gaseous phase to power SI engines, may allow reducing the fuel consumption due to AC devices through the recovery of cooling energy from the fuel systems. This paper presents lab-scale tests of an air conditioning system prototype for LPG-fuelled vehicles. The prototype has been assembled using standard vehicle components to quantify the cooling energy recoverable from the LPG evaporation before the fuel is injected into the engine intake manifold. Temperature and humidity of the air exiting the LPG evaporator are measured for fuel mass flow rates typical of light-duty vehicles. The energy efficiency ratio (EER) of the prototype achieves 2.72 when cooling power equals 1.2 kW. Although the system tested needs improvements, the experimental data show that the cooling energy recovered by LPG evaporation can significantly reduce the power consumption of standard AC systems in passenger cars
Characteristics of 1500 cc LPG fueled engine at various of mixer venturi area applied on Tesla a-100 LPG vaporizer
No full textIn the first generation of LPG kit, are called Converter and Mixer (CM), the engine power is influenced strongly by the size of mixer venturi, but this case has not been widely discussed. LPG has lower carbon content than gasoline, so it requires less air to burn. Theoretically, the amount of air to burn LPG is 46% lower than gasoline. However, in practice, the venturi area of the mixer is made from 7.5 mm2 to 10 mm2 per output hp engine. To confirm this, the mixers with venturi area of 705, 960, and 1256 mm2 are applied in Toyota 5A-FE LPG-fueled engine with Tesla A-100 LPG vaporizer. The engine performance characteristics were tested using the Hofmann Dynatest Pro chassis dynamometer and the emissions were tested using QRO-401 engine gas analyzer. The result shows that the venturi area of the mixer has a major influence on the engine power, which generates specific power characteristics. However, differences in the mixer size have little effect on emissions. This study concluded that the Toyota 5A-FE LPG-fueled engine is recommended to use a mixer with venturi area of 960 mm2 (35 mm in diameter)
Energy Efficiency Ratio (EER) of Novel Air Conditioning System on LPG Fuelled Vehicle: A Lab-Scale Investigation
Full text linkAlternative fuels have become an effective solution to reduce the impact of road transport on the environment. On the other hand, the growing uses of air-conditioning (AC) have contributed to worsening the fuel economy of passenger vehicles. Liquid petroleum gas (LPG), if injected in the gaseous phase to power SI engines, may allow reducing the fuel consumption due to AC devices through the recovery of cooling energy from the fuel systems. This paper presents lab-scale tests of an air conditioning system prototype for LPG-fuelled vehicles. The prototype has been assembled using standard vehicle components to quantify the cooling energy recoverable from the LPG evaporation before the fuel is injected into the engine intake manifold. Temperature and humidity of the air exiting the LPG evaporator are measured for fuel mass flow rates typical of light-duty vehicles. The energy efficiency ratio (EER) of the prototype achieves 2.72 when cooling power equals 1.2 kW. Although the system tested needs improvements, the experimental data show that the cooling energy recovered by LPG evaporation can significantly reduce the power consumption of standard AC systems in passenger cars
Karakteristik Pendinginan Langsung (Direct Refrigeration) Dari Proses Evaporasi Bahan Bakar Liquefied Petroleum Gas (Lpg) Untuk Pendinginan Kabin Mobil
No full textSistem Air Conditioning (AC) telah menjadi aksesoris utama pada pada kendaraan untuk
meningkatkan kenyamanan berkendaraan. Namun demikian, selama sistem AC bekerja
dengan sistem kompresi uap, akan mengambil tenaga dari mesin untuk menggerakkan
kompresor. Hal ini meningkatkan konsumsi bahan bakar hingga 21-53%. Sementara itu,
kendaraan berbahan bakar LPG menyediakan potensi pendingin langsung (direct
refrigeration) dari perubahan fase LPG pada perangkat vaporizer Potensi ini belum
dimanfaatkan dan hilang melalui engine coolant. Oleh karena itu, penelitian ini fokus pada
karakteristik direct refrigeration (potensial dan aktual) yang dihasilkan dari penguapan LPG
tersebut untuk pendinginan kabin mobil.
Penelitian ini terdiri dari empat tahapan utama. Pertama, pengujian komposisi LPG
dengan Gas Chromatography-Mass Spectromety (GC-MS). Kedua, simulasi energy delivery
dan potensi efek pendinginan pada evaporator dengan data yang diperoleh dari GC-MS.
Ketiga, validasi efek pendinginan aktual pada berbagai variasi laju aliran massa LPG dan
tekanan evaporasi. Terakhir, perhitungan COP direct refrigeration (COPDR).
Hasil penelitian ini menunjukan bahwa: 1) LPG yang keluar dari tangki selama proses
pengosongan tangki menunjukkan bahwa komposisi molekul propane dan butane 2-methyl
tidak konstan selama proses pengosongan tangki. Namun demikian, perubahan komposisi
LPG tidak berpengaruh signifikan terhadap efek pendinginan yang dihasilkan, selama LPG
yang mengalir dalam fuel line (sebelum diekspansikan) berbentuk cairan; 2). Semakin tinggi
tekanan penguapan LPG dalam evaporator dan semakin besar laju aliran massa LPG, semakin
besar efek pendinginan yang dihasilkan. Namun demikian, efek pendinginan yang dihasilkan
adalah tidak linier dengan kenaikan laju aliran massa LPG karena keterbatasan area transfer
kalor pada evaporator. Hasil pengujian menunjukkan efek pendinginan maksimal yang dapat
dibangkitkan adalah sebesar 1,2 kW. Dengan beban pendinginan sebuah mobil penumpang
berkisar antara 3-6 kW, ini berarti bahwa efek pendinginan dari sistem bahan bakar LPG
memberikan kontribusi pada sistem AC hingga 40% untuk kendaraan dengan beban
pendinginan 3 kW dan 20% untuk kendaraan dengan beban pendinginan 6 kW; dan 3) Pada
kasus Direct refrigeration, COPDR dihitung dengan membandingkan efek refrigerasi dengan
kerja kompresi untuk menghasilkan LPG cair bertekanan. Hasil perhitungan COPDR menurun
ketika laju aliran massa LPG ditingkatkan dan COPDR meningkat ketika tekanan evaporasi
dinaikkan. Nilai COPDR tertinggi adalah 6,27 yang diperoleh pada laju aliran massa LPG 1
g/s dan tekanan evaporasi 0,15 MPa. Sebagai kesimpulan, konsep direct refrigeration pada
kendaraan dengan bahan bakar LPG sangat menjanjikan untuk dikembangkan sebagai sistem
hibrida dengan sistem AC
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Hasil Peer Review "The Effect of Additive on Pertalite to Increase Motorcycle Fuel Efficiency"
Full text linkBerikut hasil Peer Review "The Effect of Additive on Pertalite to Increase Motorcycle Fuel Efficiency" oleh Prof. Dr. Ir. Abdullah Shahab, M.Sc. dan Dr. Muji Setiyo, ST., MT
Hasil Peer Review "Analisis Head Pompa Sentrifugal pada Rangkaian Seri dan Paralel"
Full text linkBerikut hasil Peer Review "Analisis Head Pompa Sentrifugal pada Rangkaian Seri dan Paralel" oleh Prof. Dr. Ir. Abdullah Shahab, M.Sc. dan Dr. Muji Setiyo, ST., MT
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