Judul: Mempelajari pemanfaatan gas buang motor bakar diesel sebagai sumber energi panas mekanis untuk alat pengering gabah tipe rak zig-zag
Abstrak: Motor bakar adalah salah satu sumber tenaga penggerak yang mudah didapat dan digunakan pada setiap waktu dan tem- pat. Pemakaian motor bakar di bidang pertanian sudah semakin luas baik di bidang pra panen maupun pasca panen. Salah satu jenis motor bakar yang digunakan di bidang per- tanian adalah motor bakar diesel. Dalam pengoperasiannya tidak semua tenaga hasil pembakaran bahan bakar pada motor bakar digunakan untuk tenaga mekanis, melainkan sebagian terbuang pada proses pendinginan dan sebagian pada gas bu ang. Gas buang yang bersuhu antara 300 sampai 600°C meru- pakan kerugian yang terbesar yaitu 34 sampai 40 persen. Pengeringan merupakan salah satu kegiatan yang penting dalam penanganan hasil pertanian terutama biji-bijian. Tu- juan pengeringan secara umum adalah untuk menurunkan kadar air bahan sampai pada kadar air yang aman untuk disimpan atau digunakan dalam proses pengolahan lebih lanjut. Pengeringan gabah di Indonesia umumnya dilakukan secara alami yaitu dengan cara penjemuran di bawah sinar matahari. ngeringan cara ini memiliki kekurangan yaitu sangat ...
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Judul: Mempelajari Motor Bakar Bensin Sebagai Sumber Tenaga Panas Dan Mekanis Pada Alat Pengering Tipe Bak
Abstrak: Motor bakar adalah salah satu sumber tenaga mekanis yang telah banyak digunakan dibidang pertanian. Kira-kira sepertiga dari panas hasil pembakaran bahan bakar hilang melalui sistim pendinginan, sepertiga hilang melalui sistim pembuangan sisa pembakaran dan sisanya lagi dirubah sebagai tenaga mekanis. Alat pengering mekanis merupakan instalasi yang ter diri dari sebuah motor penggerak dan kipas untuk mengalir- kan udara melalui bahan, suatu alat pemanas bila udara dipanasi dan sebuah "container" tempat bahan yang dikeringkan. Penelitian ini bertujuan untuk mempelajari sejauh mana tenaga panas dan mekanis motor bakar bensin dapat digunakan untuk pengeringan gabah dengan macam-macam perubahan kecepatan putaran motor dan tebal lapisan gabah. Untuk penelitian ini dibuat sebuah model alat pengering tipe bak. Motor bakar bensin dengan tenaga 4 HP digunakan sebagai sumber panas untuk memanasi udara dan untuk menggerakkan kipas. Motor tersebut diletakkan pada kotak penangkap panas yang berukuran panjang 90 cm, lebar 55 om dan tinggi 60 cm. Bahan yang dikeringkan adalah gabah dari. Varietas Pelita I/1 dengan kadar air mula-mula antara 19,5 20,5 persen. Gabah tersebut diletakkan pada "container" yang berukuran panjang 2,0 meter, lebar 1,0 meter dan tinggi 1,0 meter. Ketebalan lapisan gabah (sebagai perlakuan A) terdiri dari 30,0 cm, 40,0 cm dan 50,0 cm. Untuk kecepatan putaran motor (sebagai perlakuan B) adalah 3000 rpm, 3200 rpm dan 3400 rpm. ...
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Judul: Morfologi dan filogeografi of Clavularia inflata Schenk, 1896 Schenk, 1896 (Karang Lunak: Stolonifera) in daerah pesisir Indonesian
Abstrak: The Coral Triangle is recognized as the center of the world’s marine biodiversity, with species richness declining gradually from this region to the east across the Pacific Ocean and west across Indian Ocean. This region covers many countries, such as Indonesia, Malaysia, Philippines, Brunei, East Timor (Timor Leste), Papua New Guinea, and Solomon Islands. There are around 96 genera and 23 families of soft coral in the Indo-Pacific. In Indonesia around 219 species, 28 genera, and 4 families of soft corals have been recorded. Clavularia is spread widely throughout the Indian and Pacific Ocean, stretching from the Red Sea and East Africa across the Indo-Pacific, reaching as far east as Micronesia. Clavularia is stoloniforous zooxanthellae soft coral, each one of the polyps is connected to the base. Polyps are pink to brownish gray and about 30 mm in diameter. Stolons are brown to dark red, and are often covered with algae or sponges. Genetic connectivity is the key of conservation because it plays important roles in maintaining populations and the potential for restoring damage to the marine environment. The connectivity patterns of sessile animals are affected by reproduction and larval spread. The stage of pelagic larvae is the initial stage of life for recruitment, so that it can maintain its population from extinction. Besides, the pattern of genetic connectivity can help in designing management plans for marine protected areas, which in turn can help to preserve biodiversity. Genetic connectivity between coral reefs is often overlooked when designing an area, but it is very important to ensure the continuity of populations or protection of biodiversity. This study aimed to confirm the identity of 25 colonies collected from 13 Indonesian coral reef location putatively identified as Clavularia inflata using molecular tools, and to describe them morphologically to verify defining characteristics and describe their morphological plasticity. Specimens were morphologically described based on their sclerite characteristics and compared between sites. All specimens were confirmed as Clavularia inflata by molecular identification using mitochondrial DNA with the mtMuts gene. Sclerite observations were divided into four parts for each colony, namely pinnules (finger-like extensions along the tentacless sides), crowns (tentacles covering the upper side of polyps, located between tentacles and calyx), calyx (the middle part of polyps), and stolons (branching between polyps). The form of sclerites found in Clavularia inflata comprised various forms such as rods, fingers, sticks, and brackets. The shortest size sclerites were found in the pinnule. These sclerites had a variety of sclerites such as grains with various geometric shapes such as platelet or finger biscuit shape. In the crown, the form of sclerites found was spindle-shaped sclerites (oval shaped with a shaft in the middle) with a curved shape. The middle part of the polyp (the calyx) is mostly covered by rod-shaped sclerites. Morphometric measurements of Clavularia inflata showed specimens from Kepulauan Seribu, Jakarta had the largest pinnule, calyx, and stolon compared to other locations. The maximum mean length of pinnule, calyx, and stolon were 145.1±19.27 µm, 1605.6±30.58 µm, and 749.5±52.8 µm, respectively. The maximum mean length of crown was 672,6±39.58 µm, found in Maluku
Keyword: Alcyonacea, Coral triangle, Molecular taxonomy, Phylogeography, Population genetics