Judul: Analisis Karakteristik Kualitas Air dan Korelasinya Terhadap Kinerja Produksi Udang Vaname (Litopenaeus vannamei) di PT Biru Laut Nusantara, Pangandaran, Jawa Barat
Abstrak: Pengelolaan kualitas air menjadi salah satu faktor keberhasilan dalam budidaya udang vaname. Pengelolaan kualitas air memegang peranan penting terhadap pertumbuhan dan ketahanan terhadap penyakit. Penelitian ini dilakukan dengan melakukan pengamatan secara langsung di tambak udang vaname pada tambak pemeliharaan, tandon air, dan IPAL. Tambak pemeliharaan memiliki luasan 3025 m2 berbentuk persegi dengan konstruksi HDPE (High Density Polyethylene) dengan padat tebar 100 ekor/m2 . Parameter kualitas air yang diamati meliputi kecerahan, suhu, salinitas, pH, oksigen terlarut, kesadahan Ca, kesadahan Mg, total alkalinitas, amonia (NH3), nitrit (NO2), nitrat (NO3), Total Bakteri Count (TBC), Total Green Vibrio (TGV), Total Yellow Vibrio (TYV), Total Vibrio Count (TVC), dan Plankton. Parameter tersebut kemudian dikorelasikan dengan Survival Rate (SR), Average Daily Growth (ADG), dan Feed Conversion Ratio (FCR) serta dilakukan clustering antar tambak berdasarkan kemiripan karakteristik parameter kualitas air. Penelitian dilakukan pada DOC 40 sampai DOC 82. Selama penelitian berlangsung dilakukan sampling setiap 7 hari sekali untung menentukan ADG, SR, serta FCR. Kualitas air berkorelasi terhadap parameter tersebut, namun hanya parameter amonia (NH3), Total Yellow Vibrio (TYV), dan Total Vibrio Count (TVC) berpengaruh signifikan terhadap ADG. Karakterstick kualitas air pada petak pemeliharaan KBU 5 sudah menyerupai kualitas air pada KPL 3 ketika memasuki masa pemeliharaan 40 hari, Water quality management is one of the success factors in vaname shrimp farming. Water quality management plays an important role in growth and disease resistance. This study was conducted by making direct observations in vaname shrimp ponds on the maintenance ponds, water reservoirs, and WWTP. The rearing pond has an area of 3025 m2 square with HDPE (High Density Polyethylene) construction with a stocking density of 100 fish/m2 . Water quality parameters observed included brightness, temperature, salinity, pH, dissolved oxygen, Ca hardness, Mg hardness, total alkalinity, ammonia (NH3), nitrite (NO2), nitrate (NO3), Total Bacteria Count (TBC), Total Green Vibrio (TGV), Total Yellow Vibrio (TYV), Total Vibrio Count (TVC), and Plankton. These parameters were then correlated with Survival Rate (SR), Average Daily Growth (ADG), and Feed Conversion Ratio (FCR) and clustering between ponds based on similar characteristics of water quality parameters. The study was conducted from DOC 40 to DOC 82. During the study, sampling was conducted every 7 days to determine ADG, SR, and FCR. Water quality was correlated with these parameters, but only ammonia (NH3), Total Yellow Vibrio (TYV), and Total Vibrio Count (TVC) had a significant effect on ADG. The character of water quality in KBU 5 rearing plots already resembled the water quality in KPL 3 when entering the 40-day rearing period
Keyword: aquaculture, Litopenaues vannamei, production

Judul: Korelasi Kualitas Air dan Kinerja Produksi pada Pembesaran Udang Vaname (Litopenaeus vannamei) di PT Dewi Laut Aquaculture, Garut
Abstrak: Udang vaname (Litopenaeus vannamei) merupakan komoditas unggulan perikanan yang bernilai ekonomis tinggi. Salah satu faktor yang mempengaruhi keberhasilan budidaya udang vaname yaitu faktor kualitas air. Penelitian ini bertujuan untuk menghitung korelasi kualitas air selama pemeliharaan dan kinerja produksi udang vaname di Dewi Laut Aquaculture, Garut, Jawa Barat. Penelitian ini dilakukan dengan pengamatan secara langsung di tambak udang vaname pada tambak pemeliharaan dengan sistem intensif. Metode yang digunakan pada penelitian ini adalah analisis principal component analysis (PCA) dan uji korelasi. Parameter penelitian yang diamati adalah kualitas air (kecerahan, pH, DO, suhu, salinitas, amonia, nitrit, nitrat, alkalinitas, kesadahan, TOM, plankton, dan bakteri), survival rate (SR), average daily growth (ADG), feed conversion ratio (FCR). Hasil uji korelasi menunjukkan parameter nitrit, dan nitrat menjadi parameter yang paling banyak berkorelasi dengan parameter kinerja produksi. Parameter nitrit - 0,414 dan nitrat -0,496 berkorelasi negatif sedang dengan parameter SR. Parameter nitrit dan nitrat sama-sama berkorelasi negatif sedang dengan ADG yaitu masing masing sebesar -0,416 dan -0,424. Sementara itu, parameter nitrit dan nitrat berkorelasi positif sedang dengan parameter FCR yaitu masing-masing sebesar 0,419 dan 0,427., Whiteleg shrimp (Litopenaeus vannamei) is a leading fishery commodity with high economic value. One of the factors that affect the success of vannamei shrimp farming is the water quality factor. This study aims to calculate the correlation of water quality during rearing and production performance of vannamei shrimp in Dewi Laut Aquaculture, Garut, West Java. This study was conducted by direct observation in vannamei shrimp ponds in ponds with intensive system maintenance. The method used in this study was principal component analysis (PCA) and correlation test. The research parameters observed were water quality (brightness, pH, DO, temperature, salinity, ammonia, nitrite, nitrate, alkalinity, hardness, TOM, plankton, and bacteria), survival rate (SR), average daily growth (ADG), feed conversion ratio (FCR). Correlation test results showed that nitrite and nitrate parameters were the most correlated with production performance parameters. Nitrite -0.414 and nitrate -0.496 were moderately negatively correlated with SR parameters. The nitrite and nitrate parameters were both moderately negatively correlated with ADG at -0.416 and -0.424, respectively. Meanwhile, the nitrite and nitrate parameters were moderately positively correlated with the FCR parameter at 0.419 and 0.427.
Keyword: correlation, pond, production performance, shrimp vannamei, 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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