Judul: Analisis Kualitas Air dan Kinerja Produksi saat Outbreak Berbagai Penyakit di Tambak Intensif Udang Vaname (Litopenaeus vannamei)
Abstrak: Kualitas air berperan penting pada tambak udang terlebih saat terjadinya outbreak penyakit oleh acute hepatopancreatic necrosis disease (AHPND), white feces disease (WFD), dan white spot disease (WSD). Penelitian ini bertujuan menganalisis kondisi kualitas air dan kinerja produksi saat outbreak berbagai penyakit. Penelitian ini dilakukan pada tiga petak tambak aktif, air tandon, dan air buangan. Parameter yang diamati yaitu kinerja produksi dan kualitas air baik komponen fisika, kimia, ataupun biologi. Analisis statistik dilakukan secara deskriptif dengan teknik principal component analysis (PCA) dan klaster k-means. Hasil penelitian menunjukan parameter kualitas air yang diduga sebagai penyebab terjadinya outbreak penyakit yaitu pH, amonium, nitrit, nitrat, alkalinitas, total bacteria count (TBC), total vibrio count (TVC), total yellow vibrio (TYV), total green vibrio (TGV), dan fitoplankton dengan dominansi Cyanophyceae genus Trichodesmium sp. Laju pertumbuhan bobot harian (LPBH) semakin menurun seiring bertambahnya hari budidaya, tingkat kelangsungan hidup (TKH) dan produktivitas yang dihasilkan rendah, serta rasio konversi pakan (RKP) menunjukan nilai yang tergolong baik. Karakterisasi tambak menunjukan air tandon memiliki kualitas air yang baik dibandingkan dengan petak dan air buangan tambak, semakin meningkatnya hari budidaya karakter kualitas air pada petak tambak semakin mendekati air buangan yang memiliki karakter paling buruk diantara semua lokasi sampling., Water quality plays an important role in shrimp ponds especially during disease outbreaks by acute hepatopancreatic necrosis disease (AHPND), white feces disease (WFD), and white spot disease (WSD). This study aimed to analyze water quality conditions and production performance during outbreaks of various diseases. The study was conducted on three plots of active ponds, reservoir water, and waste water. Parameters observed were production performance and water quality in terms of physical, chemical and biological components. Statistical analysis was conducted descriptively with principal component analysis (PCA) and k-means clustering techniques. The results showed that the water quality parameters suspected as the cause of disease outbreak were pH, ammonium, nitrite, nitrate, alkalinity, total bacteria count (TBC), total vibrio count (TVC), total yellow vibrio (TYV), total green vibrio (TGV), and phytoplankton with dominance of Cyanophyceae genus Trichodesmium sp. The daily weight growth rate decreased with increasing days of cultivation, the survival rate and productivity were low, and the feed conversion ratio showed a relatively good value. Pond characterization showed that the reservoir water has good water quality compared to the plots and pond effluent water, the increasing days of cultivation of water quality characters in pond plots are getting closer to the effluent water which has the worst character among all sampling locations.
Keyword: characterization, disease, production performance, vaname shrimp, water quality

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: 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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