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"The main purpose of this work is to analyze the usefulness of the active cell model (ACM) developed by the author of this article to estimate the flow field around a single-bladed vertical-axis wind turbine (VAWT) with the Darrieus-type rotor. The obtained flow velocity fields were compared with the experimental values taken from the literature available on the Internet. Additionally, the flow fields around the rotor and the aerodynamic forces were determined using the following approaches: the 𝑘-𝜀 RNG turbulence model, the scale-adaptive simulation (SAS) and the laminar model. The velocity profiles behind the turbine rotor obtained with all numerical approaches are consistent with the experiment. The aerodynamic blade loads obtained using numerical methods also appear to be satisfactory."

"Salah satu upaya Pemerintah Indonesia dalam mengembangkan sektor transportasi nasional adalah dengan membangun proyek Kereta Cepat Jakarta-Bandung (KCJB). Proyek KCJB nantinya akan menggunakan model Fuxing CR400AF dengan kecepatan operasional 350 km/jam. Pada kecepatan tinggi, aspek aerodinamik menjadi kritikal untuk dianalisis. Salah satu tantangan yang dialami oleh kereta cepat adalah aerodynamic drag. Pada penelitian ini, dilakukan analisis CFD terkait pengaruh pemasangan vortex generator (VG) beserta variasi ketinggiannya (4 cm, 8 cm, 12 cm) pada tail carriage sebagai perangkat pengontrol aliran pasif. Hasil dari penelitian menunjukkan bahwa efek reduksi drag dan lift yang paling signifikan ditunjukkan oleh konfigurasi VG8 yang dapat mereduksi pressure drag pada tail carriage hingga 18.29% dan mereduksi koefisien angkat keseluruhan hingga 54.44%. Melalui analisis medan aliran ditemukan bahwa pemasangan VG pada titik separasi pada kereta cepat menyebabkan separasi aliran terjadi lebih awal dan memperbesar separation bubble. Separation bubble yang terbentuk ini kemudian mendisrupsi terbentuknya trailing longitudinal vortex sehingga menurunkan intensitas dan volumenya secara signifikan sehingga menghasilkan efek reduksi drag dan lift yang besar dibandingkan dengan efek penambahan pressure drag yang diakibatkan oleh membesarnya separation bubble. Temuan ini dapat menjadi acuan baru dalam upaya pengurangan drag kereta cepat, yaitu dengan melakukan pendekatan yang meminimalisir pembentukan trailing longitudinal vortex di belakang kereta cepat.

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One of the initiatives of the Indonesian government in developing the national transportation sector is by constructing the Jakarta-Bandung High-Speed Rail (KCJB) project. The KCJB project will utilize the Fuxing CR400AF train model with an operational speed of 350 km/h. At high speeds, the aerodynamic aspect becomes a very critical aspect to look for. One of the challenges of high-speed trains is aerodynamic drag. In this study, a computational fluid dynamics (CFD) analysis was conducted to investigate the effects of installing vortex generators (VG) with different heights (4 cm, 8 cm, 12 cm) on the tail carriage as a passive flow control device. The results of the research indicate that the most significant reduction in drag and lift is achieved by the VG8 configuration, which can reduce pressure drag on the tail carriage by up to 18.29% and decrease the overall lift coefficient by 54.44%. Through flow field analysis, it was found that the installation of VG at the separation point on the high-speed train causes the flow separation to occur earlier and enlarges the separation bubble. This separation bubble then disrupts the formation of the trailing longitudinal vortex, leading to a significant decrease in its intensity and volume. As a result, it produces a substantial reduction in drag and lift compared to the increase in pressure drag caused by the enlarged separation bubble. These findings can serve as a new reference in efforts to reduce drag in high-speed trains, specifically by minimizing the formation of trailing longitudinal vortices behind the train."

"Alternative energy, nowadays, becomes more necessary than fossil fuels which might be destructing and polluting the earth’s environment. Wind can be one of the most cheap, secure, environment friendly and reliable energy supplies. Building Integrated Wind Turbine (BIWT) is becoming increasingly common as a green building icon and new method of assessing optimal building energy. However, to employ BIWT, it is important to design the building shape and swept area carefully to increase wind velocity. Some of numerous design forms of BIWT will be explained in this paper using CFD (Computational Fluid Dynamics) analysis to find the most effective BIWT design in urban area. This paper will focus on the maximum wind velocity which passes the swept area to get maximum wind power. The result shows that, building energy can be optimized through aerodynamic building design to get the maximum wind power for building energy consumption."

"Pirfenidon yang dihantarkan secara peroral mengalami metabolisme lintas pertama, sehingga memerlukan dosis tinggi dan berpotensi menyebabkan efek samping sistemik. Oleh karena itu, pengembangan rute alternatif bagi pirfenidon perlu dilakukan. Penelitian sebelumnya melaporkan bahwa sistem penghantaran intrapulmonal berbasis solid lipid nanoparticles (SLN) dapat terdeposit dengan baik pada area alveolus paru-paru. Namun, karakteristik SLN dapat dipengaruhi oleh rasio lipid terhadap obat, jenis dan konsentrasi polimer. Oleh karena itu, optimisasi dengan metode permukaan respon perlu dilakukan untuk memperoleh formula SLN pirfenidon (P-SLN) yang optimal untuk penghantaran intrapulmonal. Lima belas formula disusun berdasarkan desain Box Behnken dengan tiga faktor yaitu, rasio lipid terhadap obat, jenis polimer dan konsentrasi polimer, serta tiga respon, meliputi ukuran partikel, PDI dan efisiensi penjerapan. Formula P-SLN optimal dikarakterisasi meliputi morfologi, kadar lembab, performa aerodinamik, studi disolusi dan stabilitas. Hasil optimisasi menunjukkan bahwa P-SLN optimal tersusun dari rasio lipid terhadap obat 6:1 dan 0,5% Plasdone K-29/32 (FO1). P-SLN FO1 memiliki bentuk sferis dengan ukuran partikel 212,67 nm, PDI 0,39, efisiensi penjerapan 95,02%, dan kadar lembab 1,59%. FO1 memiliki mass median aerodynamic diameter berkisar antara 0,54–12,12 μm. Selain itu, FO1 melepaskan pirfenidon sebanyak 89,61% dan 69,28% dalam medium pH 4,5 dan pH 7,4 selama 45 menit. Sebagai kesimpulan, FO1 terbukti memiliki karakteristik yang sesuai untuk menghantarkan pirfenidon melalui rute intrapulmonal.

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Orally administration of pirfenidone undergoes first-pass metabolism, hence requires high dose level and leads to systemic side effects. Therefore, it is necessary to develop an alternative route of administration for pirfenidone. Previous research reported that the solid lipid nanoparticle-based (SLN) intrapulmonary drug delivery system (IPDDS) was deposit well in the alveolar region of the lungs. However, the characteristics of SLN could be influenced by lipid-to-drug ratio, polymer type and concentration. Therefore, optimization using response surface methodology was carried out to obtain the optimized pirfenidon-loaded SLN (P-SLN) formula for IPDDS. Box-Behnken design was applied to create 15 formulas comprising three factors, including lipid-to-drug ratio, type and concentration of polymer and three responses, including particle size, PDI and entrapment efficiency. The optimized P-SLN formula was characterized, including morphology, moisture content, aerodynamic performance, dissolution and stability studies. The optimization results yielded an optimized P-SLN comprised a lipid-to-drug ratio of 6:1 and 0.5% Plasdone K-29/32 (FO1). The P-SLN FO1 had a spherical shape with a particle size of 212.67 nm, PDI of 0.39, entrapment efficiency of 95.02%, and moisture content of 1.59%. FO1 had a mass median aerodynamic diameter ranging from 0.54–12.12 μm. In addition, FO1 release 89.61% and 69.28% pirfenidone for 45 minutes in buffer medium pH 4.5 and pH 7.4. In conclusion, FO1 was proven to have an appropriate IPDDS characteristics for delivering pirfenidone."

"Studi ini mengkaji efek dari hambatan aerodinamik pada performa bus listrik UI dengan basis simulasi numerik. Dengan data yang diperoleh dari pengukuran di UI dan pengumpulan data dari berbagai sumber, dirancang sebuah simulasi yang menguji kemampuan kendaraan dengan masukan profil kecepatan. Pada studi ini dibandingkan performa dari kendaraan saat menggunakan bodi bus konvensional dan bodi bus listrik. Hasilnya adalah Cd dari bodi bus listrik lebih rendah. Walaupun demikian, signifikansi dari hambatan aerodinamik pada performa bus secara keseluruhan tidak besar untuk pengujian dengan profil kecepatan UI maupun profil kecepatan di perkotaan.

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This study examines the effects of aerodynamic drag on the performance of UI's electric bus through numerical simulation. With the data obtained from measurements in UI and data collection from various sources, a simulation was designed to test the ability of vehicles with a speed profile as an input. This study compares the performance of the vehicle when using a conventional bus body and the body of the electric bus. The result is, the Cd of the electric bus body is lower than the conventional bus body. However, the significance of aerodynamic drag on the overall bus performance is not great, both during testing with the UI speed profile and speed profile in urban areas."

"Powered flight : the engineering of aerospace propulsion aims to provide a broader context, allowing observations and comparisons to be made across systems that are overlooked by focusing on a single aspect alone. The physics and history of aerospace propulsion are built on step-by-step, coupled with the development of an appreciation for the mathematics involved in the science and engineering of propulsion. Powered flight : the engineering of aerospace propulsion covers its subject matter both theoretically and with an awareness of the practicalities of the industry. To ensure that the content is clear, representative but also interesting the text is complimented by a range of relevant graphs and photographs including representative engineering, in addition to several propeller performance charts."

"Penggunaan bahan bakar fosil, penciptaan energi dari sumber daya tak terbarukan, dan aktivitas manusia penyebab polusi semuanya berkontribusi terhadap perubahan iklim. Meskipun dianggap bahwa menggunakan angkutan umum dapat membantu mengurangi emisi karbon, namun tetap memberikan kontribusi yang signifikan. Untuk menyiasatinya, elektrifikasi transportasi umum mengurangi emisi karbon lebih cepat. Namun, penelitian lain menyatakan bahwa transportasi umum yang melistriki masih akan mahal. Tujuan dari penelitian ini adalah untuk mengetahui apakah bus harian yang digunakan oleh Universitas Indonesia lebih hemat biaya daripada diesel atau listrik. Efisiensi bahan bakar harus ditentukan untuk menilai biaya bahan bakar. Menemukan efisiensi bahan bakar sangat bergantung pada gaya aerodinamis, rolling resistance, gradient resistance, dan tenaga traksi bus. dengan cara yang mempertimbangkan dinamika bus. Simulasi digunakan untuk menghitung efisiensi bahan bakar karena dalam simulasi, kondisi operasi bus, karakteristik seperti driveline, sistem rem, mesin, dan lain-lain, serta dinamikanya, dipertimbangkan untuk menghitung konsumsi bahan bakar sebenarnya. Menggunakan bus listrik lebih hemat biaya dan konsumsi dibandingkan bus diesel. Dengan menggunakan bus berbahan bakar diesel dapat disimpulkan bahwa konsumsi bahan bakar per hari sebesar 0,27 L/Km atau sama dengan 0,891 Kwh/Km sedangkan menggunakan bus listrik konsumsi baterai sebesar 0,52 Kwh/Km. Dan biaya bahan bakar solar per km adalah Rp 2.358.892 per hari untuk satu bus Tarif listrik untuk bus listrik adalah Rp 74.258 per hari untuk satu bus.

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Fossil fuel use, the creation of energy from non-renewable resources, and pollution-causing human activities all contribute to climate change, and Indonesia has the fourth-highest global greenhouse gas emissions because of deforestation, peatland megafires, and fossil fuel consumption. Although it is thought that using public transit can help cut carbon emissions, it still contributes significantly. To get around this, electrifying public transportation reduces carbon emissions more quickly. Yet, other studies claimed that electrifying public transportation would still be costly. The goal of this study is to determine whether of the daily buses used by Universitas Indonesia the diesel or the electric is more cost-effective. The fuel efficiency must be determined to assess fuel costs. Finding fuel efficiency depends heavily on the aerodynamic force, rolling resistance, gradient resistance, and tractive effort of the bus. in ways that consider bus dynamics. Simulation is used to to calculate fuel efficiency because in simulation, the bus's operating conditions, characteristics, such as its driveline, brake system, engine, and others, as well as its dynamics, are considered to calculate the real fuel consumption. Using electric bus is more efficient by cost and by consumption than diesel bus. 1. By using a diesel bus, it can be concluded that per day the fuel consumption is at 0.27 L/Km or equal to 0.891 Kwh/Km while using the electric bus the battery consumption is at 0.52 Kwh/Km. And the fuel cost the diesel per km is Rp 2,358,892 per day for one bus The electric rate for the electric bus is at Rp 74,258 per day for one bus."