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Pesantren selain dikenal sebagai lembaga pendidikan Islam, juga dikenal sebagai lembaga sosial keagamaan. Orientasi kemasyarakatan pesantren sudah terwujud jauh sebelum pesantren dikenal oleh banyak orang. Bentuk kegiatan kemasyarakatan tradisional yang dimaksud antara lain pelayanan pengobatan dan berbagai kegiatan berbentuk pelayanan konsultasi kerohanian yang berkaitan dengan masalah kehidupan sehari-hari. Pelayanan kepada masyarakat tersebut pada dasarnya menunjukkan keinginan untuk mempertahankan kedudukan, tradisi, dan ciri kepribadian kyai dan Pesantren (Zeimek, 1986: 200). Oleh karena itu tidaklah mengherankan jika para kyai atau pimpinan pesantren pada zaman dahulu selain menguasai ilmu-ilmu agama, juga senantiasa memperdalam pengobatan tradisional dan ilmu gaib. Latar belakang pendarong utama mengapa mereka memperdalam ilmu-ilmu tersebut didasarkan pada alasan bahwa penguasaan terhadap ilmu-ilmu tersebut merupakan suatu kepandaian yang diperlukan untuk menjaga citra dan posisi kyai dan pesantren. Hal itu sungguh bermakna penting dalam pengembangan dakwah dan pengembangan pengikut kalangan kyai pesantren (Horikhosi, 1979.126 dalam Fakih, 1988:149). Perkembangan selanjutnya selain kegiatan yang bersifat kemasyarakatan dikembangkan, namun kerangka dasar pengembangannya tidak berubah yakni disamping untuk pengembangan dakwah Islam, juga dalam rangka memperkuat pengaruh pesantren di masyarakat (Fakih,l9BB:149).
Sejak awal berdirinya hingga kini, menurut Sartano Kartodirdjo dalam Suyoto (1978:72), pesantren tidak hanya berfungsi sebagai lembaga kependidikan saja tetapi juga merupakan lembaga yang sangat panting dalam membentuk kehidupan sosial, kultural, dan keagamaan. Oleh karena itu, pesantren dianggap sebagai alat transfer budaya yang dapat membawa santri dan masyarakat ke dalam lingkup pengaruh sumber-sumber nilai akhlak sehingga dapat dijadikan kerangka acuan bagi sikap yang ideal menurut ajaran Islam (Wirosardjono, 1988: 81).
Selain itu, pesantren sebagai lembaga pendidikan tradisional masih tetap menampakkan ciri-ciri yang khas. Kekhasan tersebut terletak pada pola budaya yang dapat mempertemukan secara berdampingan antara nilai-nilai tradisional dari lingkungan masyarakatnya dengan manifestasi keislamannya, sehingga terwujudlah suatu konfigurasi khas pesantren oleh Zamakhsyari Dhofier (1982: 44-60) disebut "tradisi pesantren". Kekhasan tradisi pesantren oleh Abdurahman Wahid disebut sebagai "subkultur" yakni komunitas yang mempunyai ciri, watak dan sistem nilai tersendiri. Kekhasan tersebut terletak pada aspek-aspek cara hidup yang dianut, tata nilai dan pandangan hidup yang diikuti, serta hirarki-hirarki kekuasaan intern yang ditaati (Wahid, 1988:43).

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Asap cair (pyrolysis  oil) merupakan produk yang dihasilkan dari proses pirolisis dari bahan baku biomassa dapat digunakan sebagai bahan bakar, bahan pengawet dan bahan kimia dasar. Produk cair yang dihasilkan dari proses pirolisis dipengaruhi oleh banyak parameter operasi dan jenis bahan baku. Proses optimum dari bahan baku lokal Indonesia dan sesuai dengan kondisi masyarakat menjadi dasar utama dalam penelitian ini. Parameter operasional  seperti temperatur optimum reaksi, laju pemanasan, temperatur uap pada zona reaksi, penyerapan kalor uap pada liquid collection system (LCS) dan jenis bahan baku menjadi kajian utama pada penelitian ini karena parameter-parameter ini menjadi penentu efisiensi proses dan produk pirolisis. Identifikasi jenis biomassa sesuai dengan karakteristiknya diperlukan pada penerapan proses yang sesuai untuk mendapatkan cairan yang maksimum.  Tujuan  penelitian untuk mendapatkan proses yang optimum dan fenomena transfer kalor pada proses pirolisis dengan menggunakan non-sweep gas fixed-bed reactor dengan bahan baku lokal Indonesia. Karakterisasi biomassa berdasarkan sifat difusivitas termalnya. Variasi temperatur reaksi dilakukan untuk mendapatkan temperatur optimum dan laju pemanasan bahan baku. Variasi temperatur pada zona reaksi untuk mendapatkan temperatur uap yang tepat berdasarkan jenis bahan baku. Beberapa jenis LCS digunakan, termasuk LCS yang menggunakan pipa kalor. Penggunaan LCS yang tepat meningkatkan efisiensi sistem secara keseluruhan.  Prediksi jumlah cairan dilakukan berdasarkan difusivitas termal bahan baku dengan menggunakan metode matrik, komposisi cairan yang dihasilkan diuji menggunakan GC/MS.  Temperatur optimum reaksi biomassa adalah 500 °C dan terjadi proses eksotermik pada bahan baku di dalam reaktor karena terjadinya self-ignition. Temperatur yang lebih tinggi cenderung menghasilkan produk gas sedangkan temperatur  yang lebih rendah menghasilkan lebih banyak zat arang.  Laju pemanasan tidak berpengaruh secara signifikan terhadap produk cair.  Temperatur uap pada zona reaksi mempengaruhi proses pirolisis dengan menggunakan Fixed-bed reactor non-sweeping gas. Temperatur optimum pada zona reaksi antara 150 °C sampai dengan 250 °C tergantung dari jenis bahan baku. Temperatur uap yang terlalu tinggi akan menghasilkan lebih banyak gas dan cairan dengan titik didih yang lebih tinggi, cairan ini mempunyai nilai bakar yang relatif lebih tinggi juga. Difusivitas termal  bahan baku yang lebih tinggi akan mengakibatkan penurunan laju pemanasan. Bahan baku dengan kondisi laju pemanasan yang rendah cenderung menghasilkan produk cair yang lebih tinggi. Bahan baku dengan tingkat gradien TGA rendah akan menghasilkan cairan yang lebih sedikit. Pipa kalor sebagai kondenser pada liquid collection system mampu menurunkan temperatur uap hingga mendekati temperatur ruangan dengan jumlah produk cair maksimum 42,5 wt% dengan bahan baku kayu merbau. Jumlah produk cair pada proses pirolisis dapat diprediksi dengan menggunakan variabel difusivitas termal bahan baku, laju pemanasan dan temperatur uap pada zona reaksi.  

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Liquid smokes is a product originated from the pyrolysis process using biomass as a raw material. This product can be applied as fuel oil, preservation as the chemical base material. The liquid product from the pyrolysis process influenced by many operation parameters and feedstock materials. The optimum operation parameter and easy to apply as a base consider obtaining the maximum liquid yield.   The operational parameter such as optimum reaction temperature, heating rate, vapor temperature in the reaction zone, heat absorption in the liquid collection system and the variety of raw material as the main concern in this research. Raw material identified by its thermal characterization. This research aims to obtain optimum process and heat transfer phenomena by using a non-sweep gas fixed bed reactor with local Indonesian biomass in pyrolysis. The thermal characterization base on thermal diffusivity of raw material. The variation of the reaction temperature in the reactor and vapor temperature at the reaction zone was conducted to obtain an optimum temperature base on the type of feedstock and liquid collection system.  The use of proper LCS affects the amount of liquid yield.   The liquid yield prediction base on thermal diffusivity of biomass. The composition of liquid was analyzed using GC/MS. The optimum reaction temperature for biomass was 500 °C. The higher temperature tends to produce more gases, and the lower temperature will produce more char. The heating rate does not affect the liquid yield significantly, and vapor temperature at the reaction zone affect the liquid yield in pyrolysis using a non-sweeping gas Fixed-bed reactor. The optimum temperature at reaction zone between 150 °C - 250°C depends on the raw material. The higher vapor temperature at the reaction zone produce more gases and the liquid with the higher boiling point and has higher heating value. The higher thermal diffusivity of raw material decreases the heating rate.  The lower heating rate of raw material tends to increase liquid yield. The lowest TGA gradient tends to produce less liquid. Heat pipe was applied as a liquid collection system and able to condense pyrolysis vapor up to 42.5 wt%. The liquid yield can be predicted using thermal diffusivity of raw material, heating rate, and vapor temperature at the reaction zone.

 

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Laporan praktik keinsinyuran ini mendokumentasikan langkah-langkah, tantangan, dan keputusan strategis dalam pengembangan prototipe AC untuk Kereta Ringan Hibrid dan Cerdas (KRHC) 35kW. Laporan ini bertujuan memberikan gambaran rinci terkait implementasi konsep keinsinyuran dalam pengembangan teknologi pendinginan inovatif untuk kendaraan kereta ringan. Manfaat laporan ini adalah memberikan pemahaman mendalam bagi pembaca, terkait aspek teknis dan pengambilan keputusan dalam pengembangan AC untuk KRHC 35kW. Selain itu, laporan ini dapat berkontribusi dalam memberikan pemahaman pada mahasiswa, peneliti, dan praktisi keinsinyuran yang tertarik dalam pengembangan teknologi transportasi ramah lingkungan. Aspek Dasar Keselamatan, Kesehatan, dan Kelestarian Lingkungan (K3LL) dan penerapan Kode Etik Insinyur (KEI) menjadi pondasi utama dalam pengembangan prototipe AC untuk KRHC 35kW. K3LL memastikan tidak hanya efektivitas pada teknis AC, akan tetapi juga pada kesejahteraan tim dan dampak lingkungan melalui standar keselamatan, dukungan kesehatan, kebijakan kelestarian lingkungan, dan evaluasi risiko. Sedangkan KEI menjamin keselamatan, kesehatan masyarakat, dan kerahasiaan informasi, sambil mendorong keberlanjutan lingkungan. Pada tahap pengembangan, fokus diberikan pada inovasi desain, efisiensi energi, dan keamanan operasional. Keberhasilan prototipe AC mencerminkan keterampilan teknis, manajemen proyek, dan komitmen terhadap inovasi. Prototipe ini membuka peluang untuk penerapan teknologi serupa pada pengembangan kendaraan kereta ringan hibrid dan cerdas di masa depan. ......This engineering practice report meticulously captures the intricate steps, formidable challenges, and pivotal strategic decisions entailed in crafting a prototype Air Conditioning (AC) system for the Lightweight Hybrid and Smart Train (KRHC) boasting a cooling capacity of 35kW. The primary objective is to furnish a comprehensive insight into the application of engineering principles in the development of cutting-edge cooling technology tailored for lightweight train vehicles. The report's significance extends to offering a profound understanding for readers intrigued by the intricate technical facets and nuanced decision-making processes inherent in the AC development for KRHC 35kW. Furthermore, this report significantly contributes to the knowledge pool of students, researchers, and engineering professionals with an interest in the development of eco-friendly transportation technologies. Foundational elements such as Safety, Health, and Environmental Sustainability (K3LL), coupled with the steadfast adherence to the Engineer's Code of Ethics (KEI), constitute the bedrock of the AC prototype development for KRHC 35kW. K3LL ensures not only the technical prowess of the AC but also the well-being of the development team and the environmental footprint through adherence to safety standards, healthcare support, environmental sustainability policies, and comprehensive risk evaluations. KEI plays a pivotal role in assuring safety, public health, and the confidentiality of project information, concurrently championing environmental sustainability. Throughout the developmental stages, unwavering focus is directed towards fostering design innovation, enhancing energy efficiency, and fortifying operational safety. The resounding success of the AC prototype serves as a testament to the collective technical acumen, astute project management, and unwavering dedication to innovation. Beyond its immediate achievement, this prototype heralds opportunities for the widespread application of similar technologies in the ongoing evolution of lightweight hybrid and smart train vehicles.

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Cooling systems in tropical countries consume a large part of energy usage in a building, especially in a tropical climate, which places a high demand on cooling systems throughout the year. This paper presents a simulation of a two-bed silica gel-water adsorption chiller, utilizing solar energy based in the tropical climate of Indonesia. The adsorption chiller is being mathematically modelled and calculated numerically using MATLAB®. The simulation is used to show the performance of the chiller during the working hours, based on maximum and minimum inputs of solar irradiation in Indonesia Furthermore, mass recovery and heat recovery is also applied in the adsorption cycle in order to increase the cooling capacity. The adsorption chiller is based on the most recent chiller developed by Shanghai Jiao Tong University (SJTU). The simulation results generally demonstrated the running characteristics of the chiller under a range of different values of solar radiation. Furthermore, the simulation results in detail showed that during the maximum value of irradiation, the average value of COP can reach 0.26, while during the minimum value of irradiation the COP is 0.15. At the same time, the cooling capacity is also varied which can reach up to the maximum value of 37.8 kW, whereas in the minimum range of irradiation values, the cooling capacity dropped to 5.3 kW.

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Electric car is one technology that is designed to reduce the risk of pollution that causes global warming but an air conditioning system is required to create thermal comfort for its users. Therefore national electric car (MOLINA) made by the University of Indonesia will use BLDC compressor for the air conditioning system. Cooling load calculation is required to design the air conditioning system. This research will calculate the cooling load of MOLINA UI and also select the compressor that will be used in the air conditioning system. Then, the air conditioning system that has been designed and built will be tested for its performance. In the performance test, temperature and flow velocity of MOLINA air conditioning duct will be measured. Then proceed with simulation of temperature distribution and air flow in MOLINA cabin. Moreover, the energy consumption of MOLINA air conditioning systems that is using a BLDC compressor will also be measured. Based on this research it is known that the value of the cooling load on MOLINA UI is 2894.12 Watt (9875.15 BTU/h), average energy consumption of air conditioning systems MOLINA UI without inverter is ranged about 540 to 857.3 Watts and efficiency of inverter is ranged about 84.7% to 89.4%.

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The increasing demand for energy and the current environmental issues are motivating experts to develop appropriate technology to face both problems. The binary cycle system is a highly effective generating technology which can be applied in the utilization of small-scale geothermal energy by using a working fluid that has a lower boiling point than water. In this paper, a geothermal power plant binary cycle system model was tested by using waste brine at a temperature of 180oC at well pad 4 of the Dieng geothermal power plant. In the optimization procedure, total exergy destruction and total annual cost are chosen as the objective functions. Optimization is made by using a multi objective genetic algorithm. Based on the simulation, it is known that the exergy efficiency and economic value of the optimal binary cycle of the geothermal power plant system has optimum conditions at an evaporation temperature of 163.3oC, a brine temperature in the preheater outlet of 130oC, and a water cooling temperature at condenser outlet of 35.4oC. The working fluid pressure at pump outlet is 3859 kPa with the composition of the working fluid mixture being 86% R601 and 14% R744, resulting in turbine power of 119.8 kW, total exergy destruction of 742.4 kW, and a total annual cost of 36,723 US dollars. These results indicate that, by setting the above operating conditions, the system can achieve optimum efficiency, as indicated by the minimum values of both exergy destruction and total annual cost.

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Cooling systems in tropical countries consume a large portion of the overall energy usage in a building, especially in tropical climates, where there is an especially high demand on cooling systems throughout the year. This paper presents a simulation of the effect of zeolite adsorbent granular size on a zeolite-water solar adsorption chiller for Universitas Indonesia. The adsorption chiller is being mathematically modeled and calculated numerically, using MATLAB®. The mathematical modeling is based on heat transfer principles inside the system for the water inlet and outlet of the system. The adsorption chiller is based on the most recent chiller developed by Shanghai Jiao Tong University (SJTU). The simulation results generally demonstrated the running characteristics of the chiller under a range of different values of granular size. The average granular sizes used in the simulation ranged from 0.5 mm to 1.5 mm. Furthermore, the simulation results showed in detail that the smaller the average granular size of zeolites, the faster the time needed to reach the maximum hot water temperature and the balance state of chilled water outlet temperature.

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In this paper, we perform combination methods of semi-empirical research, a theoretical approach, and force-matching to determine the optimum adsorption capacity on an open-ended single-walled carbon nanotube (SWCNT) as a diameter function. Using a semi-empirical study, we can determine the value of monolayer coverage and isosteric heat of adsorption from available thermodynamic data. By completing the semi-empirical study, we carried out quantum mechanical calculations to determine the adsorption energy on the interior and exterior of SWCNTs. Furthermore, monolayer coverage, specific surface area, and maximum adsorption capacity as the main quantity in the adsorption process was estimated using the combination method of force-matching and a classical Lennard-Jones potential model. Hydrogen physisorption was investigated on zig-zag SWCNTs at conditions for a pressure range of 0.1 to 10 MPa at 233 K and 298.15 K temperature. The adsorption of all data can be explained with the Toth model. The results shows the SWCNT exterior physisorption energy range between 1.35 to 1.62 kcal/mol. The interior range from 1.22 to 2.43 kcal/mol. With a wide degree of temperature and pressure variations, we obtained an optimum SWCNT diameter of 8-12 Å . At the optimum diameter maximum adsorption capacity, we achieved 1.75 wt% at 233 K and an operating pressure of 10 MPa.