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: Correlation of Water Quality and Production Performance in Vaname Shrimp Breeding (Litopenaeus vannamei) at 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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