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: Relation of Water Quality and Production Performance of Vaname Shrimp (Litopenaeus vannamei) with Intensive System at BPBAP Takalar, South Sulawesi
Abstrak: Udang vaname (Litopenaeus vannamei) memiliki lonjakan permintaan baik dari pasar lokal maupun pasar ekspor, dengan sistem budidaya udang vaname pada saat ini yaitu sistem intensif hingga supra intensif. Tingginya permintaan dan produksi udang sejalan dengan permasalahan yaitu penurunan kualitas air. Hubungan kualitas air sangat berpengaruh terhadap kinerja produksi sehingga perlu diperhatikan dan dijaga keseimbangannya. Penelitian ini bertujuan untuk menganalisis kaitan kualitas air terhadap kinerja produksi pada tambak Divisi Pembesaran Udang Vaname (Litopenaeus vannamei) di BPBAP Takalar, Sulawesi Selatan. Penelitian ini merupakan penelitian non eksperimental menggunakan data sekunder. Prosedur penelitian melakukan observasi lapangan, wawancara, dan menganalisis parameter kualitas air dengan kinerja produksi udang vaname. Parameter yang diamati yaitu laju pertumbuhan harian (LPH), kelangsungan hidup (KH), rasio konversi pakan (RKP), dan kualitas air. Analisis data dilakukan secara deskriptif dengan pemaparan grafik dan uji statistik principal component analysis (PCA) serta uji korelasi. Hasil analisis deskriptif menunjukan nilai LPH, KH, dan RKP mengalami fluktuasi. Berdasarkan hasil uji PCA kualitas air yang memiliki hubungan terhadap LPH yaitu DO pagi, nitrit, nitrat, dan phospat sedangkan kinerja produksi KH dan RKP yang memiliki hubungan dengan alkalinitas, bahan organik, dan suhu pagi. Berdasarkan hasil uji korelasi kualitas air terhadap kinerja produksi dengan koefisien korelasi dan Sig(<0,05) dihasilkan LPH memiliki korelasi terhadap suhu sore dengan nilai (-0,045) (0,004), DO sore (0,669) (0,00), kecerahan (0,439) (0,005), nitrit (0,398) (0,011), nitrat (0,357) (0,024), dan bahan organic (-0,333) (0,036). Kualitas air yang memiliki pengaruh signifikan terhadap KH yaitu suhu pagi dengan nilai (0,340) (0,032) dan phospat (-0,343) (0,030). Hasil uji korelasi kualitas air terhadap RKP yang signifikan yaitu suhu pagi dengan nilai (0,324) (0,041) dan kecerahan (0,316) (0,047)., Vannamei shrimp (Litopenaeus vannamei) has a surge in demand from both the local and export markets, with the current vaname shrimp cultivation system, namely the intensive to supra intensive system. The high demand and production of shrimp is in line with the problem of decreasing water quality. Water quality correlation of aquaculture environment have impact to production performance so that it needs to be considered and maintained in balance. This study aims to analyze the relationship between water quality and production performance in the Vaname Shrimp (Litopenaeus vannamei) rearing pond at BPBAP Takalar, South Sulawesi. This research is a non-experimental research using secondary data. The research procedure was conducting field observations, interviews, and analyzing water quality parameters with the production performance of vaname shrimp. Parameters observed were average daily growth (ADG), survival rate (SR), feed conversion ratio (FCR), and water quality. Data analysis was carried out descriptively with graphic presentation and principal component analysis (PCA) statistical tests and correlation tests. The results of the descriptive analysis showed that the ADG, SR, and FCR values fluctuated. Based on the results of the PCA test, water quality that has a relationship with ADG is DO, nitrite, nitrate, and phosphate while the production performance of SR and FCR have a relationship with alkalinity, organic matter, and morning temperature. Based on the results of the correlation test of water quality on production performance with a correlation coefficient and Sig (<0.05) the resulting LPH has a correlation with afternoon temperature with
Keyword: production performance, water quality, vaname shrimp

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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