Judul: Design and Performance Test of an Aerator using Venturi Tube Methods as Finebubble Generator
Abstrak: Oksigen merupakan hal penting bagi makhluk hidup di darat maupun di air. Oksigen yang terdapat di air disebut DO (Dissolved Oxygen) merupakan salah satu faktor penentu kualitas air. Penelitian ini bertujuan untuk merancang bangun serta melakukan uji kinerja aerator dengan metode venturi tube sebagai pembangkit finebubble. Penelitian dimulai dengan penyiapan alat dan bahan, penentuan kriteria desain, ide rumusan konsep desain, pembuatan venturi tube, perakitan komponen, pengujian kinerja alat. DO meter dan software ImageJ digunakan pada pengujian kinerja alat. Hasil dari pengujian menunjukkan penggunaan lapisan saringan berpengaruh pada diameter bubble, durasi kembalinya nilai DO, dan konsumsi daya listrik alat. Kenaikan nilai DO saat aerator dirunning menunjukkan kenaikan drastis pada 5 menit pertama. Perlakuan aerator dengan tidak menggunakan saringan menghasilkan diameter sebesar 0,0067 mm dan mengkonsumsi daya listrik per menitnya sebesar 0,00036 kWh dengan durasi nilai DO kembali semula selama 7 jam 26 menit. Perlakuan dengan saringan mesh 200 dan 500 menghasilkan diameter bubble masing-masing 0,005mm dan 0,0023mm. Kebutuhan daya per menit untuk perlakuan mesh 200 dan 500 masing-masing mengalami kenaikan sebesar 25% dan 27,7% dari perlakuan tanpa saringan. Durasi nilai DO kembali semula untuk perlakuan mesh 200 dan 500 masing-masing mengalami kenaikan 23,89% dan 77,6% dari perlakuan tanpa saringan., Oxygen is important thing for organisms on land and in water. The oxygen contained in water is called Dissolved Oxygen. which is one of the determining factors for water quality. This study aims to design and perform aerator performance tests using venturi tube method as a finebubble generator. The research begins with preparing tools and materials, design criteria, conceptual ideas, making venturi tubes, assembling components, testing performance. DO meter and ImageJ software are used in tool performance testing. The results of the test show that the use of the mesh screen affects the bubble diameter, the duration of the return of the DO value, and the power consumption of the appliance. The DO value when aerator is running shows drastic increase in the first 5 minutes. Aerator treatment by without a filter produces a diameter of 0,0067 mm and consumes electricity per minute of 0,00036 kWh, duration of the original DO value for 7 hours 26 minutes. Treatment with 200 and 500 mesh screens resulted in a bubble diameter of 0,005mm and 0,0023mm, respectively. The power requirements per minute for 200 and 500 mesh treatments increased by 25% and 27,7% from untreated treatment. The duration of DO value returned to the original 200 and 500 mesh treatment increased 23,89% and 77,6% from the treatment without filter.
Keyword: Aerator, Bubble, Dissolved Oxygen, Finebubble, Venturi Tube

Judul: Uji Kinerja Aerator Fine bubble pada Perkecambahan Biji Tanaman Sengon (Falcataria moluccana Miq.)
Abstrak: Benih Sengon (Falcataria moluccana Miq.) termasuk benih dengan kulit biji yang keras sehingga sulit ditembus oleh air dan oksigen yang menghambat proses perkecambahan. Micro-Nano Bubble (MBS) memecah dormansi pada benih. Diperlukan uji kinerja penggunaan aerator fine bubble dengan metode venturi tube terhadap benih sengon serta membandingkan hasil perkecambahan tersebut dengan perendaman air Ultrafine Bubble (UFB). Tujuan dari penelitian ini adalah untuk menguji kinerja aerator fine bubble dengan metode venturi tube sebagai pembangkit fine bubble pada perkecambahan biji tanaman sengon (Falcataria moluccana Miq.). Pengamatan yang dilakukan adalah daya berkecambah, potensi tumbuh maksimum, dan indeks vigor. Perlakuan terdiri dari air aquades, aerator tanpa mesh, aerator mesh 200, aerator mesh 500, dan UFB. Aerator di running 1 kali dan 3 kali. Air UFB memiliki DO tertinggi yaitu 9 ppm. DO yang dihasilkan dari running aerator tanpa menggunakan mesh mengalami kenaikan tertinggi sebesar 1,16 ppm. Perkecambahan, potensi tumbuh maksimum, indeks vigor, dan daya berkecambah pada perlakuan aerator 3 kali running lebih besar dibandingkan dengan perlakuan aerator sekali running dan aquades, namun lebih rendah sampai 3,33% dibandingkan dengan perlakuan UFB. Potensi tumbuh maksimum, indeks vigor, dan daya berkecambah tertinggi terjadi pada aerator mesh 200 sebanyak 3 kali running berturut turut sebesar 83%; 80,67%; dan 81,33%. Kata kunci : aerator fine bubble, micro-nano bubble, sengon, viabilitas, vigor
Keyword: aerator fine bubble, micro-nano bubble, sengon, viabilitas, vigor, aerator fine bubble, micro-nano bubble, sengon, viabilitas, vigor

Judul: Lejeuneaceae Subfamily Ptychanthoideae (Hepaticae) in  West Java
Abstrak: Subfamily Ptychanthoideae of the family Lejeuneaceae (Hepaticae) in West Java is still poorly known. Publications on this subfamily are out of dated and written in the 19th or early of 20th century. The last taxonomic treatment of Ptychanthoideae of West Java was in 1933, many species names have changed since then. Studies on Ptychanthoideae of West Java are urgently needed. Studies on the Ptychanthoideae were based on the specimens collected from West Java. A total number of 361 of specimens deposited in the Herbarium Bogoriense (BO), Herbarium Biotrop (BIOT), Gottingen Herbarium (GOET) and Bangi Herbarium (UKMB) were examined, those are old and several recent specimens collected in West Java. Recent collections were made from Telaga Warna, Ciater, Gunung Halimun Salak National Park, Cibodas Botanical Garden, Bodogol Education Center and Conservation (Gunung Gede Pangrango National Park), University of Indonesia Campus Depok, including several collections from Banten Province. Twenty four species of Lejeuneaceae subfamily Ptychanthoideae are known from West Java, belonging to 8 genera namely Acrolejeunea (Spruce) Schiffn. (2 species), Archilejeunea (Spruce) Schiffn. (1 species), Lopholejeunea (Spruce) Schiffn. (10 species), Mastigolejeunea (Spruce) Schiffn. (3 species), Ptychanthus Nees (1 species), Schiffneriolejeunea Verd. (1 species), Spruceanthus Verd. (2 species) and Thysananthus Lindenb. (4 species). Two new records of Ptychanthoideae: Mastigolejeunea indica Steph. and Thysananthus minor Verdoorn are reported for Java. A determination key to the species is presented including their descriptions and illustrations.
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