Penggunaan Batubara sebagai Pengganti Kerosin untuk Menghemat Biaya Produksi Campuran Aspal Panas

Studi ini bertujuan untuk mendukung program pemerintah sesuai dengan Peraturan Presiden no. 5tahun 2006 tentang sasaran energi jangka panjang Indonesia tahun 2000-2025, yang tujuannyamencari dan menggunakan energi alternatif lain, yaitu, coal, gas, hydro, geothermal, biomass, angin,surya dan nuklir. Selama ini mesin pembuat campuran aspal panas (Asphalt Mixer Plant)menggunakan kerosin sebagai bahan bakar untuk memanaskan batu pecah, abu batu dan pasirsebelum dicampur dengan aspal semen. Permasalahan yang dihadapi selama ini adalah sampaidengan saat ini ketersediaan bahan bakar kerosin semakin sulit diperoleh dan harganya semakintinggi. Sehingga biaya produksi menjadi tidak effisien lagi dan waktu penyelesaian pekerjaan (proyek)sering tidak sesuai rencana. Dari hasil penelitian, batubara dapat digunakan sebagai penggantikerosin untuk membakar agregat pada Alat pembuat campuran aspal panas (Asphalt Mixer Plant)dengan cara mengganti burner kerosin dengan burner batubara. Dari segi biaya, terbukti bahwapemakaian batubara lebih hemat. Dari segi peralatan mesin produksi campuran aspal panas (AsphaltMixer Plant) dapat dioperasikan dengan menggunakan bahan bakar batubara yang harganya lebihmurah dan performance mesin tersebut sama dengan apabila menggunakan bahan bakar kerosin.Riset ini dilakukan pada Mesin Pembuat Campuran Aspal Panas (Asphalt Mixer Plant) milik PT.Waskita Karya, merek Shin Sheng, type SAP 800 Batch, kapasitas 50 Ton/jam

Reflective low-sideband plasmonic structural colors

It is demonstrated experimentally that an aluminum (Al) nanowire grating structure on silicon substrates can produce low-side-band monochromatic peak when it reflects colored light in the transverse magnetic (TM) mode. The central wavelength of the reflection is shown to be sensitive to the incident angle, which leads to significant color shifts. Formation of the monochromatic peak is attributed to the surface plasmon resonance on the interface between Al and air, together with remarkable diffraction at shorter wavelengths and strong Fabry-Perot (F-P) resonance absorption by Al-surrounding nano-cavities and silicon substrate at longer wavelengths. In contrast, reflection in transverse electric (TE) mode does not show distinct wavelength selectivity due to the cut-off effect of the nano-cavities. The outstanding characters of the proposed structure with polarization dependence, high sensitivity to incident angle, high color rendering facilitate more compact and sophisticated color-filter-based devices for displays, anti-counterfeit, and sensing applications. In addition, the two-dimensional structure with thin grating thickness and high duty ratio tolerance is relatively easy for fabrication

Characterization of thermal, optical and carrier transport properties of porous silicon using the photoacoustic technique

In this work, the porous silicon layer was prepared by the electrochemical anodization etching process on n-type and p-type silicon wafers. The formation of the porous layer has been identified by photoluminescence and SEM measurements. The optical absorption,energy gap, carrier transport and thermal properties of n-type and p-type porous silicon layers were investigated by analyzing the experimental data from photoacoustic measurements. The values of thermal diffusivity, energy gap and carrier transport properties have been found to be porosity-dependent. The energy band gap of n-type and p-type porous silicon layers was higher than the energy band gap obtained for silicon substrate (1.11 eV). In the range of porosity (50–76%) of the studies, our results found that the optical band-gap energy of p-type porous silicon (1.80–2.00 eV) was higher than that of the n-type porous silicon layer (1.70–1.86 eV). The thermal diffusivity value of the n-type porous layer was found to be higher than that of the p-type and both were observed to increase linearly with increasing layer porosity