Judul: Birth Time Synchronization of Guppy Poecilia reticulata Using  Different Combinations of Temperature and Oxytocin Hormone Dose
Abstrak: Ikan gapi termasuk ke dalam jenis livebearer, yaitu telur berkembang dan menetas dalam tubuh induk yang selanjutnya dilahirkan dalam bentuk anak. Pemijahan massal ikan gapi terdapat kendala, yaitu waktu melahirkan induk yang tidak sinkron, sehingga sulitnya manajemen pemeliharaan yang mengakibatkan produksi menjadi tidak efisien. Penelitian ini bertujuan menentukan dosis hormon oksitosin dan suhu yang digunakan untuk meningkatkan sinkronisasi waktu melahirkan ikan gapi. Metode yang digunakan adalah perendaman induk gapi bunting selama 12 jam. Penelitian ini menggunakan rancangan acak lengkap faktorial dengan delapan perlakuan dan tiga kali ulangan. Dosis oksitosin yang digunakan adalah 0; 0,1; 0,2; 0,4 mL.L-1 pada suhu 28 °C dan 31 °C. Perlakuan hormon oksitosin dosis 0,4 mL.L-1 melalui perendaman induk gapi bunting selama 12 jam, dapat meningkatkan sinkronisasi waktu kelahiran 53,33–56,67% pada suhu 28 °C dan 31 °C. Tidak ditemukan adanya interaksi antara suhu dan dosis hormon oksitosin terhadap persentase induk melahirkan., Guppy is included in the type of livebearer, where the eggs develop and hatch in the broodstock's body which are then born in the form of larvae. The mass spawning of guppy has several problems due to its out of sync birth time, which makes it difficult for the maintenance management and resulting in inefficient production. This study aims to determine the dose of oxytocin hormone and temperature used to increase the birth time synchronization of guppy. The method used was through immersion of the broodstock of guppy for 12 hours. This study used a factorial completely randomized design with eight treatments and three replications. The dose of oxytocin used was 0; 0,1; 0,2; 0,4 mL L-1 at 28 °C and 31 °C. The oxytocin dose of 0.4 mL.L-1 by immersing the broodstock of guppy for 12 hours, can increase the birth of synchronization from 53.33 to 56.67% at 28 °C and 31 °C. There was no interaction between temperature and oxytocin dose treatment on the percentage of broodstock giving birth.
Keyword: :guppy, immersion, oxytocin, synchronization, temperature

Judul: Effectiveness of Giving Thyroxine Hormone and Recombinant Growth Through Feed on the Spawning of Poecilia reticulata Guppy Fish
Abstrak: Ikan guppy merupakan ikan hias air tawar yang memiliki corak menarik dan menjadi salah satu ikan hias air tawar yang memiliki potensi ekspor yang cukup menjanjikan. Permasalahan pada ikan guppy adalah lambatnya ikan mulai berkembang biak dan membutuhkan waktu yang cukup lama yaitu 21–30 hari setelah proses melahirkan untuk melahirkan kembali. Penelitian ini bertujuan untuk menguji efektivitas pemberian tiroksin dan pertumbuhan rekombinan melalui pakan terhadap pemijahan ikan guppy. Penelitian ini dilakukan dengan metode eksperimental menggunakan rancangan acak lengkap (RAL) dengan 5 perlakuan: 15 mg tiroksin dan 1,5 mg/kg rGH, 20 mg tiroksin dan 2 mg/kg rGH, 25 mg tiroksin dan 2,5 mg/kg rGH, 30 mg tiroksin dan 3 mg/kg rGH, dibandingkan dengan perlakuan kontrol tanpa pemberian hormon tiroksin dan rGH dengan 3 ulangan untuk masing-masing perlakuan. Parameter yang diamati meliputi rematurasi, jumlah larva dan abnormalitas. Hasil terbaik dari parameter rematurasi terdapat pada perlakuan 30 mg tiroksin dan 3 mg/kg rGH. Parameter jumlah larva yang terbaik terdapat pada perlakuan 25 mg tiroksin dan 2,5 mg/kg rGH (37 ekor) dan meningkat 37% dari kontrol akan tetapi tidak berbeda nyata, sedangkan larva yang dihasilkan tidak ada yang mengalami abnormalitas., Guppy fish are freshwater ornamental fish that have attractive patterns and are one of the freshwater ornamental fish that have quite promising export potential. The problem with guppy fish is that the fish start to reproduce slowly, and it takes quite a long time, namely 21–30 days after giving birth to give birth again. This research aims to test the effectiveness of providing thyroxine and recombinant growth through feeding on guppy fish spawning. This research was carried out using experimental methods using a completely randomized design (CRD) with 5 treatments: 15 mg thyroxine and 1.5 mg/kg rGH, 20 mg thyroxine and 2 mg/kg rGH, 25 mg thyroxine and 2.5 mg/kg rGH, 30 mg thyroxine and 3 mg/kg rGH, compared with the control treatment without administration of thyroxine and rGH hormones with 3 replications for each treatment. Parameters observed included rematuration, number of larvae and abnormalities. The best results for rematuration parameterswere found in the treatment of 30 mg thyroxine and 3 mg/kg rGH. The best parameters for the number of larvae were found in the treatment of 25 mg thyroxine and 2.5 mg/kg rGH (37 individuals) and increased by 37% from the control but were not significantly different, while the larvae produced did not experience any abnormalities.
Keyword: abnormality, guppy fish, number of larvae, rematuration

Judul: Characterizations of low alloy steel sae 4422  plated with chromic acid (Cro3)
Abstrak: Characterizations of low alloy steel SAE 4422 plated with chromic acid (CrOrO3) was use Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), RD),Energy Dispersive Analysis of X-Ray (EDAX), Hardness Test and Roughness Test. Microstructures analysis exhibits cracks and grain boundaries microcracks as a characteristics of chrome metal found at plating metal. Perlite and Ferrite as grains of steel found at base metal with grain boundaries around it. Phase analysis of plating metal appropriate to chrome metal with lattice constant (a) is 2.559 Å and phase analysis of base metal appropriate to iron ferrite with lattice constant (a) is 3.318 Å. Both plating and base metal have cubic system. Chemical analysis of plating metal at surface section exhibits that cracks area have highest value of carbon element compare with grains and grains boundaries area. While chemical analysis of base metal at cross section exhibits that perlite have highest value of carbon element compare with ferrite and grain boundaries. The hardness value of plating metal at surface section and cross section are 753 and 637 VHN. While, the hardness value of base metal and interface area at cross section are 205 and 373 VHN. The roughness value at measurement points of chrome surface for as received sample are 0.445 μm. Observation used Optical Microscopy and Scanning Electron Microscopy exhibits surface irregularities combine to form surface texture of plating metal at surface section.
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