19 research outputs found
Anti-wear properties of bio-grease from modified palm oil and calcium soap thickener
Full text link Sukirno1, Ludi1, Rizqon2, Bismo1, Nasikin1 (1. Department of Chemical Engineering, University of Indonesia; 2. Laboratory for Thermodynamics, Motor and Propulsion BPPT Indonesia, Department of Chemical Engineering, University of Indonesia Depok 16424, Indonesia) Abstract: An environmental friendly palm-grease has already been formulated using modified palm oil as base oil and calcium 12-hydroxy-stearate as thickener. Such palm-grease is dedicated for bearing and gear applications in industrial equipment that requires food-grade lubricant, such as in food processing and pharmaceutical machineries. The grease was manufactured via four steps of processes: saponification in a pressurized reactor, soap dilution by heating, crystallization by cooling, and homogenization. Additive-free palm-grease using modified RBDPO (Refined Bleached Deodorized Palm Oil) and epoxy RBDPO as the base oil and calcium soap as thickener gave dropping point of 130℃ and consistency NLGI Grade 3. In the test using 4-ball wear-test, it showed an anti-wear performance that was comparable to that of the commercial food-grade grease, using mineral oil as base oil. The ability of the palm-grease to provide an anti-wear property was probably due to the presence of epoxy ring -COC-, ester groups -COOC- and hydroxides –OH. Keywords: Bio-grease, modified RBDPO, consistency, dropping point, anti-wear property Citation: Sukirno, Ludi, Rizqon, Bismo, Nasikin. Anti-wear properties of bio-grease from modified palm oil and calcium soap thickener. Agric Eng Int: CIGR Journal, 2010, 12(2): 64-69.  
The Influence of Injection Timing on Performance Characteristics of Diesel Engine Using Jatropha Biodiesel with and without Partial Hydrogenation
Full text linkExperimental research has been conducted to investigate the effects of blend of hydrogenated and unhydrogenated Jatropha biodiesel with diesel fuel in volume ratio of 30:70 (B30) on combustion characteristics (BSFC, thermal efficiency and smoke emission) of single cylinder diesel engine. In this experiment, engine speed was kept constant at 1,500, 2,500, and 3,500 rpm with maximum engine load at BMEP 5 bar and injection timings were varied. Experimental result showed that at engine speed 1,500 rpm, BSFC of B30 hydrogenated and unhydrogenated Jatropha biodiesel were higher than it of diesel fuel at all injection timings (10° to 18° BTDC). At the same condition, partial hydrogenated Jatropha biodiesel showed higher BSFC than unhydrogenated Jatropha biodiesel. However, the difference in BSFC became smaller for all fuels at engine speed 2,500 rpm and 3,500 rpm at all injection timing. Jatropha biodiesel with and without partial hydrogenation tend to have higher thermal efficiency compared with diesel fuel at all engine speed and injection timing. The best injection timings to operate B30 Jatropha biodiesel with and without hydrogenation were 14°, 18° and 24° BTDC at engine speed 1,500, 2,500, and 3,500 rpm respectively. This conclusion was deduced based on the minimum value of BSFC and the maximum value of thermal efficiency. Smoke emissions for all fuels were in the same level for all conditions
Kajian Fuel Economy Untuk Kendaraan Jenis Sedan dan MPV Dengan Menggunakan Bahan Bakar Gas Dan Berbagai Jenis Bensin Yang Tersedia Di Indonesia
No full textThe Nurcu Movement and Tafsir Risale-i Nur: Formation of Muslim Identity in the Midst of Modernization
Full text linkThis article discusses the Nurcu movement and Risale-i Nur amidst the process of modernization during Republican Turkey. The atheistic science adopted during the modernization absorbed Said Nursi’s concern. In attacking the philosophy of materialism and atheism, he resorted to an attempt to interpret the Qur'an, namely Risale-i Nur. Through the Risale-i Nur, a group of Said Nursi's followers came together into a social movement, which is known as the Nurcu movement. This article aims to reveal how Said Nursi faced modernity and posited the Nurcu movement in the midst of modernity. This research used a content analysis approach to the works written by Said Nursi, especially Risale-i Nur, as the main data, and supplementary data were gathered from studies conducted by scholars concerning Said Nursi, Risale-i Nur, and the Nurcu movement. In addition, reading on the intellectual context surrounding the emergence of Risale-i nur becomes a tool to comprehend the content of Risale-i Nur and the thoughts of the author. This research found that with the presence of Risale-i Nur, the followers of Said Nursi's teachings make Risale-i Nur a marker of group identity bringing with them tasks to seize science and modernity. Said Nursi's work is a modernist kind of interpretation of the Quran. Thus, in the midst of modernization and secularization in Turkey, Risale-i Nur offers Muslims an identity
Membangun Peradaban dengan Epistemologi Baru: Membaca Pemikiran Said Nursi
No full textThere are three models of approaches to modernity that was born in the West; 1) accepting it by taken for granted, 2) rejecting it, and 3) trying to find a new alternative in addition to the Western civilization with the spirit of re-establishing the practice of ijtihad, erasing taklid, and returning to al-Quran and al-Sunnah. This article discussed the idea of Said Nursi in the reconciliation of science and Islam. It offered an epistemological approach that integrates Islam and science. The author attempted to break the academic problem and borrowed Ian Barbour’s approach. Four reactions that occur as a result of the encounter of science and religion: conflict, independence, dialogue, and integration. The theory states that the first step to make the integration go smoothly is removing science from materialist philosophy. This step is performed by Nursi. Nursi built a new epistemology as an offer to the condition of Muslims, who at that time should redevelop the civilization which was left behind by European nations. Nursi reconciled Islam and science towards integrity. Nursi was against Materialism for the first step. Secondly, he put the al-Qur’an as the highest source of science. By making the method of science under the principles and worldview of the al-Qur’an, it can change the modern scientific understanding of the universe to be in accordance with the description of the al-Qur’an
ERDOĞAN VERSUS GÜLEN: Perebutan Pengaruh antara Islam Politik Post-Islamis dengan Islam Kultural Apolitis
No full textAbstract: This article is aimed at disclosing a conflict of military coup attempt in Turkey occurring on July 15, 2016. The research question addressed in this article is why Fethullah Gülen was to blame in the military coup. It was clearly read that military coups happening in the story was as a personal feud between Recep Tayyip Erdoğan and Fethullah Gülen. To obtain an overall picture of the dispute in the coup attempt, the author presents three conflicting groups: secularists, Islamist or ultranationalist elites and moderate Muslim called cemaat. Military represents a secular group, Erdoğan represents Islamist or ultranationalist elites, while Gülen represents moderate Muslim pro-Western brand of Sunni Islam. The conflict between the Gülen and Erdoğan was actually triggered to get more influence in the Turkish national political stage. The author noted that this personal conflict was really a feud between the both two men from different groups of Muslims having different perspective though really both of them coming from one religion (Islam) and one stream sect (Sunni). Gülen had struggled through a political cultural lines, while Erdoğan had fought through political channels post-Islamism.
ملخص: يتناول هذا البحث النزاع المحتدم حول محاولة الانقلاب العسكري الذي حدث في تركيا 15 يوليو 2016. ويحاول هذا البحث الإجابة على سؤال واحد مفاده : لماذا تشير أصابع الاتهام إلى فتح الله كولن ويلقى اللوم عليه؟ من الملحوظ جليا أن الانقلاب العسكري في هذه المرة تعكس نزاعا فرديا بين رجب طيب إردوغان وفتح الله كولن. وتجلية للصورة الحقيقية من هذا النزاع، يتناول الباحث ثلاث فئات لكلٍّ منها دورها في هذه المحاولة الانقلابية: فئة علمانية تتمثل في العسكرية التركية، وفئة إسلامية سياسية تتمثل في حزب رجب طيب إردوغان، وفئة إسلامية ثقافية تحت قيادة فتح الله كولن. فالنزاع المحتدم بين كولن وإردوغان في الحقيقة هو من جرّاء تنافسهما في استجلاب الهيمنة على المسرح السياسي في الدولة. ويرى الباحث أن هذا النزاع الفردي يعود إلى نزاع بين مسلمين يمثلان تيارين إسلاميين مختلفين في منهجية النظر، مع أنهما ينتميان إلى دين واحد (الإسلام) وينبثقان من مذهب واحد (المذهب السني). فكولن يختار المسار الثقافي اللاسياسي، بينما يفضّل إردوغان المسلك السياسي على منوال ما بعد الإسلاموية.
Abstrak: Artikel ini mengupas konflik di seputar kudeta militer di Turki yang terjadi pada tanggal 15 Juli 2016. Pertanyaan riset yang dibahas dalam artikel ini adalah mengapa dalam kudeta militer tersebut justru Fethullah Gülen yang disalahkan? Terbaca dengan jelas bahwa kudeta militer kali ini bercerita tentang perseteruan personal antara Recep Tayyip Erdoğan dengan Fethullah Gülen. Untuk memperoleh gambaran utuh mengenai perseteruan ini penulis menghadirkan tiga kelompok yang berkonflik dalam drama kudeta tersebut: kelompok sekuler, Islam politik dan Islam kultural. Militer mewakili kelompok sekuler. Erdoğan mewakili Islam politik, sedangkan Gülen mewakili Islam kultural. Konflik antara Gülen dengan Erdoğan sesungguhnya dipicu oleh perebutan pengaruh di panggung nasional Turki. Penulis melihat bahwa konflik personal ini tidak lain adalah perseteruan antara dua sosok Muslim dan sekaligus dua kelompok Islam yang berbeda dalam cara pandang meskipun sama-sama berasal dari satu agama (Islam) dan satu aliran (Sunni). Gülen berjuang lewat jalur kultural apolitis, sedangkan Erdoğan berjuang melalui jalur politik post-Islamisme
Optimizing Palm-Based Bio-ⅼubricant Formulations for Diesel Engine Using Machine Learning and Experiment Techniques
No full textIntegrating bio-lubricants into internal combustion engines is crucial for sustainable engineering, driven by the need for renewable and eco-friendly alternatives. However, bio-lubricants in diesel engines often face challenges related to insufficient thermal-oxidative stability. This research introduces a novel approach to enhance the thermal-oxidative stability and lubricity of palm oil-derived bio-lubricants for diesel engine applications. By chemically modifying palm olein through transesterification, epoxidation, and oxirane ring-opening, and leveraging the predictive capabilities of the 'BimolP' machine learning tool, we identified base stocks with improved properties. Our results show significant enhancements in thermal-oxidative stability, with the decomposition onset temperatures (T_) of modified palm olein increasing from 280°C to 281°C and 295°C, and those of palm methyl ester derivatives rising from 222°C to 245°C and 268°C. Additionally, the friction coefficient of palm olein derivatives increased from 0.104 to 0.106 and 0.113, and for methyl ester derivatives, it rose from 0.101 to 0.108 and 0.113. The final bio-lubricant formulation combines various modified base stocks to meet SAE-30 and SAE-40 diesel lubricant specifications. This study underscores the effectiveness of integrating chemical modifications, machine learning predictions, and blending palm-based stocks to optimize bio-lubricant formulations without the need for prior synthesis or modification of palm olein and palm methyl ester
Aircraft and High Speed Train Using the Logit Model A Case Study of The Jakarta-Surabaya Route
No full text
