Judul: Suitability of Water Quality to Vaname Shrimp Production Performance at the Jepara Brackish Water Aquaculture Center
Abstrak: Udang vaname merupakan varietas unggul yang memiliki permintaan pasar tinggi dari skala lokal maupun internasional. Keberhasilan produksi udang vaname yang unggul harus memperhatikan beberapa aspek internal dalam budi daya yaitu kualitas air. Penelitian ini bertujuan menganalisis kesesuaian parameter kualitas air dengan produksi udang vaname yang berjumlah empat tambak di Balai Besar Perikanan Budidaya Air Payau Jepara, Jawa Tengah dengan kepadatan dan lama pemeliharaan yang hampir sama. Hasil pengamatan menunjukkan bahwa kinerja produksi tambak A62 memiliki produktivitas yang paling rendah dibandingkan ketiga tambak lainnya yaitu 17.140,69 kg/ha yang dikarenakan pada tambak A62 memiliki nilai TOM yang tertinggi sebesar 30,10-193,12 mg/L. Data parameter kualitas air yang memiliki hubungan erat dengan kinerja produksi yaitu suhu sore, DO pagi, DO sore, salinitas pagi, salinitas sore, nitrat, alkalinitas, dan fosfat yang diketahui dari uji korelasi bersifat negatif (-0,400-(-0,799)). Data tersebut merupakan hasil analisis korelasi yang berhubungan secara signifikan (<0,05) terhadap kinerja produksi udang., Vaname shrimp is a superior variety that has high market demand on a local and international scale. Successful production of superior white shrimp requires paying attention to several internal aspects in cultivation, namely water quality. This research aims to analyze the suitability of water quality parameters with the production of vaname shrimp in four ponds at the Center for Brackish Water Aquaculture Fisheries in Jepara, Central Java with almost the same density and length of maintenance. Observation results show that the production performance of pond A62 has the lowest productivity compared to the other three ponds, namely 17,140.69 kg/ha, because pond A62 has the highest TOM value of 30.10-193.12 mg/L. Data on water quality parameters that have a close relationship with production performance are afternoon temperature, morning DO, afternoon DO, morning salinity, afternoon salinity, nitrate, alkalinity and phosphate which are known from the correlation test to be negative (-0.400-(-0.799)). This data is the result of correlation analysis which is significantly related (<0.05) to shrimp production performance.
Keyword: kinerja produksi, kualitas air, udang vaname, production performance, vannamei shrimp, water quality

Judul: Relationship of Water Quality and Production Performance of Vaname Shrimp (Litopenaeus vannamei) at PT Persada Karya Lestari, Pesawaran Regency, Lampung
Abstrak: Ekspor udang menjadi sumber devisa yang lebih besar dibandingkan dengan ekspor produk perikanan lainnya di Indonesia. Potensi udang yang prospektif diikuti juga dengan permasalahan dalam budidaya yang dapat menyebabkan kegagalan panen akibat penurunan kualitas air. Penurunan kualitas air cepat terjadi pada tambak udang sistem intensif dengan padat tebar yang tinggi. Faktor lain yang berpengaruh pada budidaya udang yaitu adanya agen patogen yang dapat menurunkan tingkat kelangsungan hidup udang vaname. Penelitian ini bertujuan untuk menganalisis hubungan kualitas air dan kinerja produksi pada tambak udang vaname (Litopenaeus vannamei). Parameter yang diukur pada penelitian ini adalah average daily growth (ADG), survival rate (SR), feed conversion ratio (FCR), kualitas air, dan indikator kesehatan udang. Hasil uji korelasi menunjukkan bahwa kualitas air memiliki hubungan terhadap kinerja produksi udang vaname. Parameter kualitas air yang berhubungan terhadap ADG secara signifikan adalah pH pagi, total ammonia nitrogen (TAN), alkalinitas bikarbonat, dan rasio total vibrio count (TVC) dan total bacterial count (TBC). Tidak ada parameter kualitas air yang berhubungan signifikan terhadap SR. Parameter kualitas air yang berhubungan secara signifikan terhadap FCR adalah pH pagi, pH siang, suhu pagi, alkalinitas karbonat, alkalinitas bikarbonat, dan rasio total vibrio count (TVC) dan total bacterial count (TBC). Kata kunci: kinerja produksi, kualitas air, udang vaname., Shrimp exports become a greater source of foreign exchange compared to the export of other fishery products in Indonesia. The potential of prospective shrimp is also followed by problems in cultivation that can lead to crop failure due to decreased water quality. Rapid decline in water quality occurs in intensive system shrimp ponds with high density. Another factor that affects shrimp cultivation is the presence of pathogenic agents that can decrease the survival rate of shrimp vaname. This study aims to analyze the relationship of water quality and production performance in shrimp ponds vaname (Litopenaeus vannamei). The parameters measured in this study are average daily growth (ADG), survival rate (SR), feed conversion ratio (FCR), water quality, and shrimp health indicators. The results of the correlation test showed that water quality has a relationship to the production performance of vaname shrimp. The water quality parameters associated with ADG are significantly the morning pH, total nitrogen ammonia (TAN), bicarbonate alkalinity, and the ratio of total vibrio count (TVC) and total bacterial count (TBC). There are no water quality parameters significantly related to SR. Water quality parameters significantly related to FCR are morning pH, afternoon pH, morning temperature, carbonate alkalinity, bicarbonate alkalinity, and total vibrio count (TVC) and total bacterial count (TBC) ratio. Keywords: production performance, shrimp vaname, water quality.
Keyword: production performance, shrimp vaname, water quality

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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