273 research outputs found
A Novel Organic Rankine Cycle (ORC) for High Temperature Applications
No full textThe current experimental ORC setups for long-haul Heavy Duty Diesel Engines (HDDE) are not reaching the desired fuel savings within the expected costs. Pathways to improve ORC performance and cost-effectiveness remain a major challenge facing the automotive sector. This paper presents the conceptual overview and simulation results (using Aspen HYSYS) of a novel ORC especially tailored for high temperature heat sources (300-400°C) in truck applications. With a fundamental revision of the expansion and heat transfer characteristics, the advantage of the proposed novel ORC included an equivalent performance to the conventional ORC despite a 20% reduction in the total heat transfer area and a 40% reduction in the size of the expansion machine. This resulted in a 15% improvement in the Cost/kW value of the system, whilst offering 5.1% improvement in engine thermal efficiency at highway driving conditions
Book review: Middle East approaches
No full textAuthor reviews: Andrew Duncan, "Money rush"; Mohamed Heikal, "Sphinx and commissar
IMPLEMENTASI KEBIJAKAN DIPLOMATIK INDONESIA-MALAYSIA DI BIDANG PENDIDIKAN (STUDI KASUS PADA KEDUTAAN BESAR REPUBLIK INDONESIA KUALA LUMPUR DAN KONSULAT JENDERAL REPUBLIK INDONESIA JOHOR BAHRU)
No full textABSTRAK
IMPLEMENTASI KEBIJAKAN DIPLOMATIK INDONESIA-MALAYSIA DI BIDANG PENDIDIKAN (STUDI KASUS PADA KEDUTAAN BESAR REPUBLIK INDONESIA KUALA LUMPUR DAN KONSULAT JENDERAL REPUBLIK INDONESIA JOHOR BAHRU)
Mohammad Heikal Alfredo, Idrus Affandi, Leni Anggraeni
Universitas Pendidikan Indonesia
[email protected]
Pendidikan untuk semua merupakan kesepakatan global yang beririsan dengan konstitusi Republik Indonesia yakni dalam mencerdaskan kehidupan bangsa. Untuk mencapai hal ini maka pelayanan pendidkan haruslah menyinggung setiap sendi kehidupan masyarakat baik itu di dalam negeri maupun luar negeri. Pada penelitian ini akan membahas mengenai kerjasama Indonesia dan Malaysia di bidang pendidikan serta implementasinya secara hubungan diplomatik. Dengan menggunakan metode kualitatif studi kasus penulis hendak menggambarkan peran dan kebijakan serta kendala yang dihadapi KBRI Kuala Lumpur dan KJRI Johor Bahru dalam diplomasi implementasi kerjasama pendidikan , bersama pihak terkait dalam hal ini Atase Pendidikan KBRI Kuala Lumpur dan Konsul Pensosbud KJRI Johor Bahru maka informasi yang di dapat bisa dipastikan valid. Selama lebih dari 60 tahun hubungan diplomatik Indonesia dan Malaysia kerjasama pendidikan yang sudah terjalin sejak dahulu yang mana Indonesia banyak mengirim tenaga pengajar untuk Malaysia hingga saat ini kualitas pendidikan di Malaysia menduduki nomor 2 di Asia Tenggara. Hal ini yang membuat penulis tertarik untuk meneliti kebijakan pendidikan Indonesia dan Malaysia. Kebijakan diplomasi apa yang dilakukan oleh KBRI Kuala Lumpur dan KJRI Johor Bahru dan kendala yang di hadapi akan dijelaskan oleh penulis.
Kata Kunci : Kerjasama Pendidikan, Indonesia dan Malaysia, KBRI Kuala Lumpur, KJRI Johor Bahru
ABSTRACT
IMPLEMENTATION OF INDONESIA-MALAYSIA DIPLOMATIC POLICY IN THE FIELD OF EDUCATION (CASE STUDY AT THE EMBASSY OF THE REPUBLIC OF INDONESIA KUALA LUMPUR AND THE CONSULATE GENERAL OF THE REPUBLIC OF INDONESIA JOHOR BAHRU)
Mohammad Heikal Alfredo, Idrus Affandi, Leni Anggraeni
Universitas Pendidikan Indonesia
[email protected]
Education for all is a global agreement that intersects with the constitution of the Republic of Indonesia, namely in the intellectual life of the nation. To achieve this, education services must touch every aspect of people's lives, both at home and abroad. This study will discuss the cooperation between Indonesia and Malaysia in the field of education and its implementation in diplomatic relations. By using a qualitative case study method, the author would like to describe the roles and policies as well as the obstacles faced by the Indonesian Embassy in Kuala Lumpur and the Indonesian Consulate General in Johor Bahru in the diplomacy of implementing educational cooperation, together with related parties, in this case the Education Attaché of the Indonesian Embassy in Kuala Lumpur and the Consul for Social and Cultural Affairs of the Indonesian Consulate General in Johor Bahru. can be ascertained valid. For more than 60 years of diplomatic relations between Indonesia and Malaysia, educational cooperation has existed for a long time, in which Indonesia has sent many teaching staff to Malaysia. This makes the writer interested in researching the education policy of Indonesia and Malaysia. The diplomatic policies carried out by the Indonesian Embassy in Kuala Lumpur and the Indonesian Consulate General in Johor Bahru and the obstacles faced will be explained by the author. Keywords : Education Coorporation, Indonesia and Malaysia, Indonesia Embassy in Kuala Lumpur, Indonesian Consulate General in Johor Bahru
تراجم مصرية وغربية : كليوباطرة - إسماعيل باشا - توفيق باشا - محمد قدري باشا - بطرس غالي باشا - مصطفى كامل باشا - قاسم أمين بك - إسماعيل صبري باشا - محمود سليمان باشا - عبد الخالق ثروت باشا - بتهوفن - تين - شكسبير - شلي / تأليف الدكتور محمد حسين هيكل بك.
No full textMuhammad Hussein Heikal, the esteemed writer, masterfully captures the essence of Egyptian politics in the modern era with his captivating and dynamic writing style. He does this by writing biographies about impactful historical figures
Time-resolved fuel injector flow characterisation based on 3D laser Doppler vibrometry
No full textHydrodynamic turbulence and cavitation are known to play a significant role in high-pressure atomizers, but the small geometries and extreme operating conditions hinder the understanding of the flow's characteristics. Diesel internal flow experiments are generally conducted using x-ray techniques or on transparent, and often enlarged, nozzles with different orifice geometries and surface roughness to those found in production injectors. In order to enable investigations of the fuel flow inside unmodified injectors, we have developed a new experimental approach to measure time-resolved vibration spectra of diesel nozzles using a 3D laser vibrometer. The technique we propose is based on the triangulation of the vibrometer and fuel pressure transducer signals, and enables the quantitative characterisation of quasi-cyclic internal flows without requiring modifications to the injector, the working fluid, or limiting the fuel injection pressure. The vibrometer, which uses the Doppler effect to measure the velocity of a vibrating object, was used to scan injector nozzle tips during the injection event. The data were processed using a discrete Fourier transform to provide time-resolved spectra for valve-closed-orifice, minisac and microsac nozzle geometries, and injection pressures ranging from 60 to 160 MPa, hence offering unprecedented insight into cyclic cavitation and internal mechanical dynamic processes. A peak was consistently found in the spectrograms between 6 and 7.5 kHz for all nozzles and injection pressures. Further evidence of a similar spectral peak was obtained from the fuel pressure transducer and a needle lift sensor mounted into the injector body. Evidence of propagation of the nozzle oscillations to the liquid sprays was obtained by recording high-speed videos of the near-nozzle diesel jet, and computing the fast Fourier transform for a number of pixel locations at the interface of the jets. This 6-7.5 kHz frequency peak is proposed to be the natural frequency for the injector's main internal fuel line. Other spectral peaks were found between 35 and 45 kHz for certain nozzle geometries, suggesting that these particular frequencies may be linked to nozzle dependent cavitation phenomena
Investigation of the internal dynamics of diesel nozzles by time-resolved laser doppler vibrometry
No full textThermodynamic analysis and system design of a novel split cycle engine concept
No full textAbstractThe split cycle engine is a new reciprocating internal combustion engine with a potential of a radical efficiency improvement. In this engine, the compression and combustion–expansion processes occur in different cylinders. In the compression cylinder, the charge air is compressed through a quasi-isothermal process by direct cooling of the air. The high pressure air is then heated in a recuperator using the waste heat of exhaust gas before induction to the combustion cylinder. The combustion process occurs during the expansion stroke, in a quasi-isobaric process. In this paper, a fundamental theoretical cycle analysis and one-dimensional engine simulation of the split cycle engine was undertaken. The results show that the thermal efficiency (η) is mainly decided by the CR (compression ratio) and ER (expansion ratio), the regeneration effectiveness (σ), and the temperature rising ratio (N). Based on the above analysis, a system optimization of the engine was conducted. The results showed that by increasing CR from 23 to 25, the combustion and recuperation processes could be improved. By increasing the expansion ratio to 26, the heat losses during the gas exchange stroke were further reduced. Furthermore, the coolant temperatures of the compression and expansion chambers can be controlled separately to reduce the wall heat transfer losses. Compared to a conventional engine, a 21% total efficiency improvement was achieved when the split cycle was applied. It was concluded that through the system optimization, a total thermal efficiency of 53% can be achieved on split cycle engine
A late injection combustion strategy using a novel ramped combustion system
No full textTraffic related NOx and particle emission remain a significant concern particularly in the urban environment. Electrification offers a medium to long term solution, but there remains a need to significantly reduce internal combustion engine emissions in the short and medium term, and potentially in the long term for long range inter city transportation. Late injection low temperature combustion (LTC) has the potential to achieve ultra-low emissions levels in a compression ignition engine by increasing the lean pre-mixed burn fraction. However, significant quantities of diluent are normally required to achieve the required delay in ignition and pre-mixing to achieve LTC. This results in high boost requirements, increased pumping work and the complexity of the air handling system and potentially adversely impacting fuel economy. In this paper, results from a single cylinder light duty research engine are presented using a novel ramped combustion chamber focused at mid to high engine loads. The ramped combustion chamber improves mixing and enables more retarded injection timings than those possible on conventional bowl designs. This combustion strategy has enabled LTC conditions to be achieved at lower dilution rates, typically 20-30% at loads up to 15bar IMEP. CFD analysis of the air-fuel interaction indicates the ramped bowl effectively deflects fuel away from the squish region enabling very late injection timings. One dimensional analysis of the engine system was used to investigate the potential of late exhaust valve opening in improving work recovery, resulting in improved fuel consumption over the baseline LTC valve timing
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