Respon Struktur Portal Baja Akibat Beban Gempa dengan Analisis Riwayat Waktu Nonlinier

Earthquakes are dynamic loads that greatly affect the state of the building structure. If the strength of the building can not withstand the dynamic load, then the building will be damaged even will collapse. The purpose of this study was to identify the structural response in the Indonesian quake region by using nonlinear dynamic analysis. Structural modeling using Banda Aceh, Bengkulu and Pekanbaru earthquake locations with medium soil condition on a 10-storey building made of steel with a constant inter-floor height of 4 m. Time history analysis in earthquake plan using 3 accelerated earthquake accelerator, namely: Kobe, Imperial Valley and Chichi earthquake. Each earthquake accelerator was given three treatments: 1). The earthquake scale is decreased by 50% (0.5 g), 2). Normal earthquake scale (1 g), and 3). The scale of the earthquake is increased by 200% (2 g). The analysis results show that the displacement, velocity, and acceleration of earthquake-load structures in each region are directly proportional to the increasing or decreasing of the earthquake-scale in buildings that do not occur in plastic joints

Teknologi Pengolahan Kandungan Kromium dalam Limbah Penyamakan Kulit Menggunakan Proses Adsorpsi: Review

Permasalahan yang sering terjadi pada industri-industri saat ini adalah pengolahan limbah yang tidak sempurna. Salah satu jenis industri yang memerlukan perhatian serta pengolahannya adalah limbah yang mengandung kromium seperti pada industri penyamakan kulit. Limbah penyamakan kulit masih menyisihkan logam-logam berbahaya dalam limbahnya seperti logam berat kromium (Cr). Kromium yang digunakan untuk menghasilkan olahan kulit yang lebih halus. Sekitar 30-40% kromium akan terbawa dalam limbah cair penyamakan. Tingginya kadar kromium yang tersisa dan terbawa dalam limbah dapat menyebabkan toksisitas akut dan kronis terhadap lingkungan bahkan juga sangat berbahaya terhadap mahluk hidup. Salah satu penanganannya adalah dengan menggunakan metode adsorpsi yang dimana merupakan salah satu metode alternatif dengan berbagai keuntungan yang ada. Biaya penanganan yang relatif murah, proses yang sederhana, dan kemungkinan dapat didaur ulang merupakan beberapa keuntungan dari proses adsorbsi. Selain itu, proses adsorbsi dapat dimaksimalkan dengan menggunakan adsorben yang memiliki spesifikasi potensi tertentu terhadap penyerapan kromium. Artikel ini me-review perbandingan metode adsorbsi batch dan kontinyu pada proses pengolahan kandungan kromium dalam limbah penyamakan kulit.The waste management issue is one of the biggest problems in the industries recently. Every industry has a high probability of releasing toxic by-product to the environment in the form of waste. One example is in the leather tanning industry. Leather tanning waste still removes harmful metals in its waste, such as heavy metal chromium (Cr). Chromium is used to produce finer skin products. About 30-40% chromium will be carried in the tanning liquid waste. The high chromium levels remaining and carried away in the waste can cause acute and chronic toxicity to the environment and even very harmful to living things. Adsorption is one of the highly recommended methods available to overcome this problem. Relatively low handling costs, simple processes, and the possibility of being recycled are some of the adsorption process's advantages. In addition, the adsorption process can be maximized by using adsorbents that have specific potential specifications for chromium absorption. This article reviews batch and continuous adsorption methods in the processing of chromium content in tannery waste

Sintesis Bahan Bakar Padat Berbahan Baku Residu (Char) Hasil Pirolisis Limbah Plastik

Penggunaan produk berbahan plastik memiliki banyak keunggulan yaitu ringan, kuat dan kedap air. Keunggulan plastik ini menyebabkan semakin meningkatnya penggunaan plastik di masyarakat. Plastik memiliki sifat non biodegradable yang menyebabkan penumpukan limbah plastik. Hal tersebut menyebabkan dampak negatif terhadap lingkungan dan kesehatan bagi makhluk hidup. Beberapa jenis plastik bersifat termoplastik sehingga dapat berubah sifat jika dipengaruhi oleh temperatur. Sifat ini menjadi dasar bahwa plastik dapat mengalami Perubahan sifat baik secara fisika maupun kimia melalui proses pirolisis. Konversi limbah Plastik melalui proses pirolisis dapat merubah wujud plastik menjadi Fase liquid, gas dan padat (residu). Pesidu (char) dari hasil proses pirolisis limbah plastik dapat dimanfaatkan sebagai bahan baku sintesis Bahan Bakar Padat. Variabel bebas pada penelitian ini adalah variasi ukuran partikel (50 dan 150 mesh) dan variasi perekat (damar: turpentine, minyak jelantah: oli bekas). Rasio damar: turpentine (30:70, 40:60, 50:50, 60:40, dan 70:30) dan rasio minyak jelantah: oli bekas (100:0, 0:100 dan 50:50). Sampel dikarakterisasi menggunakan analisa proksimat. Hasil analisa sampel yang memenuhi standar Bahan Bakar Padat berdasarkan SNI, nilai kalor optimum 7.843,7 cal/g diperoleh dari sampel dengan ukuran 150 mesh dan perekat oli bekas

Advancements in Ni‐based Catalysts for Direct Urea Fuel Cells: A Comprehensive Review

Abstract The growing demand for sustainable energy sources has spurred significant studies to optimize the potency of fuel cell technology. Direct urea fuel cell (DUFC) has gained attention due to their energy density, eco‐friendliness, and potential applications in power generation using urea from various sources, including wastewater and urine. Efficient electrocatalysts are pivotal in DUFCs, and nickel‐based catalysts, particularly in the form of NiOOH, have demonstrated cost effectiveness, excellent stability in alkaline media, and good activity for urea oxidation reaction. However, low‐density and durability are still the major limitation in the overall DUFC performance. This review provides a comprehensive analysis of the latest development in Ni‐based catalysts, covering synthesis methods, factors influencing the catalytic activity as well as their implications for DUFC performance durability and commercial viability. In addition, another important factor including the use of different oxidant and electrolyte medium is also elaborated. Based on this review, 2D‐3D Ni‐based materials with the addition of other metals and the use of non‐oxide nickel binary compound are predicted to be the future evolution of the effective nickel‐based catalysts