The stabilization of soil through the addition of fly ash has been shown to be an effective alternative for improving the strength and stiffness of soil through the resulting chemical reactions. The chemical reaction that occurs dissociates the lime (CaO) in the fly ash, and the establishment of cementitious and pozzolanic gels (consisting of calcium silicate hydrate (CSH) gel and calcium aluminate hydrate (CAH) gel) binds the soil particles and increases the strength and stiffness of the soil. Investigations into the mechanical properties of sands stabilized with fly ash (fly-ash-stabilized sands) were conducted through a series of unconfined compressive strength (UCS) and direct shear strength tests for various fly ash percentages, curing times, grain sizes, degrees of saturation during sample preparation, and content of fines. It was found that the mechanical properties—UCS and direct shear strength (DSS)—of fly-ash-stabilized sands increased with both increasing fly ash content in the specimen and curing time, but decreased with increasing grain size, degree of saturation during sample preparation, and content of fines. The results indicated that fly-ash-stabilized sands required more than a month to attain their optimum performance with regard to binding sand particles.

In the face of the depletion of fossil fuels, alternative fuels such as biomass are needed. However, biomass has a fairly low calorific value and several other disadvantages compared to petroleum. Therefore, a new breakthrough is needed to correct these weaknesses, one of which is the Torrefaction process. The purpose of this study was to determine the effect of torrefaction of coconut shell and cashew shell biomass on the physical and chemical properties of the material. This research was conducted using coconut shells and cashew shells. The results of this study indicate that the calorific value of coconut shells and cashew shells after torrefaction is 5115,297-5147,021 cal/gr. The water content in coconut shells is 2.718% and the value of water content in cashew shells is 2.397%, the ash content of coconut shells is 6.853% and the value of cashew shell ash content is 6.600%, the value of volatile levels of coconut shells is 14.885% and the value of volatile levels of cashew shells of 14.557% and the value of fixed carbon content of coconut shell is 75.574% and the value of fixed carbon content of cashew shell is 76.447%. Keywords : Biomass, coconut shell, cashewnut shell, torrefaction

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<div class="section abstract"><div class="htmlview paragraph">An experimental study has been conducted at small kerosene droplet behavior near well-defined butane diffusion flame for the critical need on high efficient and cleaner energy technology. High temperature of background gas was generated using butane flame. Microflame from butane can reach the maximum temperature around 1200K at tip of outer glass. Single droplet of kerosene was injected by a small injector tube (30 μm-diameter) in to hot environment. Droplet of kerosene was released by attachment of piezo actuator on wall injector. Once the droplet is exposed to the hot atmosphere of micro flame, the temporal regression of the droplet surface was recorded. Droplet diameter was observed by CCD camera with strobe light flash at 180ns. The images captured in this experiment were analyzed by post-processing software to determine the vaporization of droplet. Temperature of background gas was measured by K-type thermocouple and speed of droplet released from injector was also measured to investigate the effect of relative velocity between droplet and background gas. The result shows that the linear changing point of droplet diameter is started at different droplet temperature and different initial velocity. For further movement to high temperatures environment the vaporization rate of droplet is almost linear with time.</div></div>

ABSTRAK Tata guna lahan, jaringan infrastruktur jalan dan pergerakan manusia dapat mempengaruhi perkembangan serta peningkatan sistem tranportasi perkotaan. Aktivitas transportasi yang tinggi akan berdampak pada peningkatkan emisi gas buang di udara seperti CO2, CO, HC, CH4, SO2, NO2 dan partikulat yang dapat memicu pencemaran udara.  Apabila tidak di imbangi dengan penambahan kawasan Ruang Terbuka Hijau maka daya dukung penyerapan emisi CO2 menjadi berkurang.Penelitian ini bertujuan untuk menganalisis tingkat emisi CO2 dari konsumsi bahan bakar kendaraan darat serta daya dukung Ruang Terbuka Hijau dalam menyerap emisi CO2 diKota Kendari. Data primer berupa konsumsi bahan bakar berdasakan penyaluran Terminal Bahan Bakar Minyak di kota kendari, sedangkan luasan Ruang Terbuka Hijau mengacu pada RTH yang dikelola oleh Pemerintah Kota Kendari. Analisis yang digunakan dalam menghitung emisi CO2 adalah metode “tier 1” yang dikeluarkan oleh Intergovernmental Panel on Climate Change (IPCC) 2006, sedangkan analisis kemampuan daya serap RTH  menggunakan data luasan pada setiap jenis tutupan lahan.Hasil penelitian ini menunjukan bahwa terjadi peningkatan emisi CO2 yang signifikan akibat konsumsi bahan bakar kendaraan di Kota Kendari sejak tahun 2015 sampai tahun 2018, dimana tingkat emisi tahun 2015 sebesar 265.910,92 ton/tahun, sedangkan tahun 2018 mencapai 326.039,40 ton/tahun.  Luas dan daya dukung Ruang Terbuka Hijau existing tidak mampu menyerap keseluruhan jumlah emisi CO2 yang disebabkan oleh konsumsi bahan bakar kendaraan darat, dimana jumlah emisi yang mampu diserap pada tahun 2018 sebesar 267.884,74 ton dari total emisi 326.039,40 ton sehingga Kota Kendari masih membutuhkan RTH seluas 102,9 hektar. Kata kunci: Emisi CO2, Kendaraan Darat, Ruang Terbuka Hijau ABSTRACT [Study Of Land Transportation Contribution On The Improvement Of CO2 Emissions And Inventory Of Ability Of Green Open Space Absorption In Kendari City]. Land use, road infrastructure networks and human movement can enhance the development and improvement of the transportation system. High transportation activities will increase emissions of CO2, CO, HC, CH4, SO2, NO2 and particulate emissions which can increase air pollution. If it is not balanced with the addition of the Green Open Space area, the carrying capacity of CO2 emissions will be reduced.This study aims to analyze CO2 emissions from land vehicle fuel consumption and carrying capacity of Green Open Space in saving CO2 emissions in Kendari City. Primary data consist of fuel consumption based on the distribution of fuel terminals in the city of Kendari, while the area of the Green Open Space is in accordance with the green space managed by the Kendari City Government. The analysis used in the calculation of CO2 emissions is the "level 1" method issued by the 2006 Intergovernmental Panel on Climate Change (IPCC), while the analysis of the capacity of green space absorption uses area data on each type of land cover.The results of this study indicate a significant increase in CO2 emissions in vehicle fuel consumption in Kendari City from 2015 to 2018, where the level of emissions in 2015 amounted to 265,910.92 tons / year, while in 2018 it reached 326,039.40 tons / year. The extent and carrying capacity of the Green Open Space is unable to reduce the amount of CO2 emissions caused by vehicle fuel consumption, while the amount of emissions that can be absorbed in 2018 is 267,884.74 tons of the total emissions of 326,039.40 tons so that the City of Kendari needs to require green space covering an area of 102.9 hectares. Keywords: CO2 emissions, land transportation, green open space