Analisis Perbedaan Pendapataan Usaha dan Efisiensi Budidaya Ikan Tambak di Kabupaten Cirebon (Studi Kasus : Ikan Bandeng dan Udang Vaname)

Penelitian ini merupakan penelitian kuantitatif dengan metode survey dan kuisioner pada petambak ikan bandeng dan udang vaname. Judul penelitian ini adalah “ Analisis Perbedaan Pendapatan Usaha dan Efisiensi di Kabupaten Cirebon (studi Kasus: Ikan Bandeng Dan Udang Vaname)” . penelitian ini bertujuan untuk mengetahui pendapatan usaha dan tingkat efisiensi tambak ikan bandeng dan udang vaname serta perbedaannya, agar petambak nantinya dapat meningkatkan pendapatan usaha dan tingkat efisiensi usahanya serta pemerintah dapat membuat kebijakan yang dapat meningkatkan pendapatan usaha dan tngkat efisiensi usaha tambak ikan bandeng dan udang vaname.metode pengumpulan data pada penelitian ini adalah dengan caran memeberikan kuisioner kepada responden sebsnayak 84 orang, data yang digunakan adalah data primer. Alat analisis yang digunakan dalam penelitian ini adalah analisis pendapatan usaha, R/C ratio, uji hipotesis dua mean dengan sampel besar (n1 ; n2 ; ≥ 30). Berdasarkan hasil penelitian diketahui bahwa usaha tambak ikan bandeng dan udang vaname memiliki pendapatan usaha yang besar atau menguntungkan (TR > TC ) dan telah mencapai tingkat efisien (R/C > 1). Pendapatan usaha tambak ikan bandeng lebih kecil dari pendapatan usaha tambak udang vaname. Sedangkan tingkat efisiensi usaha tambak ikan baneng lebih besar dari usaha tambak udang vaname.upaya untuk meningkatkan pendapatan usaha dan tingkat efisiensi usaha tambak ikan bandeng dan udang vaname.adalah dengan cara adanya pengolahan benih sendiri yang dilakukan petambak, pengunaan faktor produksi yang lebih optimal oleh petambak dan penjagaan kualitas air dari limbah oleh pemerinta

Studi Kinerja Turbin Angin Sumbu Horizontal NACA 4412 Dengan Modifikasi Sudu Tipe Flat Pada Variasi Sudut Kemiringan 0º, 10º, 15º

Turbin Angin adalah alat yang digunakan untuk mengkonversi energi angin menjadi energi listrik melalui sudu turbin yang kemudian diteruskan ke generator. Dimensi, sudut serang, maupun material yang digunakan sering kali dimodifikasi oleh para peneliti untuk mendapatkan efisiensi optimum. Dalam penelitian ini modifikasi dilakukan pada sudu turbin dengan material plat besi dengan tebal 3mm. Sudu didesain dengan tipe Flat berdasarkan profil NACA 4412 (National Advisory Committe for Aeronautics) pada variasi sudut kemiringan 0º, 10º, 15º. Proses pembuatan turbin angin diawali dengan mendesain turbin pada software AutoCAD dan SolidWorks. Setelah itu dlanjutkan dengan proses pemindahan desain ke plat besi dengan tebal 3mm yang selanjutnya dilakukan proses shearing sesuai dengan bentuk sudu. Setelah didapatkan bentuk sudu kemudian dilanjutkan proses bending sesuai dengan sudut yang sudah didapatkan dari profil NACA 4412. Proses yang tak kalah penting yaitu proses balancing sudu dengan cara menimbang sudu agar didapatkan berat sudu ketiga-tiganya sama. Proses terakhir yaitu proses pengecekan dengan memasang seluruh instalasi turbin angin dan mencobanya sebelum pengujian di alam. Pada pengujian turbin angin kali ini dilakukan di alam pada ketinggian 8 meter dan variasi sudut kemiringan 0º, 10º, 15º. Pengambilan data meliputi kecepatan angin, daya, energi dan juga Rpm dilakukan selama 2 jam pada masing –masing sudut kemiringan. Dari hasil pengujian didapatkan hasil bahwa Rpm tertinggi yang didapat saat pengujian dengan pembebanan yaitu sebesar 587 Rpm, pada kemiringan sudut 15º. Sedangkan Rpm terendah yaitu sebesar 127,3 Rpm pada pengukuran sudut 10º. Untuk akumulasi energi terbesar didapatkan pada kemiringan sudut 15o yaitu sebesar 51,85 watt.jam. Sedangkan untuk akumulasi energi paling sedikit yaitu pada kemiringan sudut 10o yaitu sebesar 14,96 watt.jam. Sedangakan efisiensi terbesar didapatkan pada pengujian dengan kemiringan sudut 15o, yaitu sebesar 4,44%. Sedangkan nilai efisiensi tekecil didapatkan pada pengujian dengan kemiringan sudut 0o, yaitu sebesar 4,16%

Removal of Copper Ions from Aqueous Solution Using Waste Mill Scales

The optimization of the Copper ions (Cu ions) adsorption from aqueous solution for inclusion in prolonged the milling time of the extracted iron oxides from waste mill scales has been investigated. Different milling times were used to reduce the size of the raw mill scale which are 24, 48 and 72 h. The three adsorbents were characterized using XRD, FESEM and VSM. Adsorbents that milled for 72 hours gave pure magnetite from the XRD results. FESEM images revealed that prolonged the milling time might reduced the particle sizes. Magnetic hysteresis revealed that all the samples having ferromagnetic behavior. Batch adsorption experiment had been carried out with the three adsorbents and as the results, adsorbents that milled with 72 hours shown highest removal of Cu ions with 95% removal efficiency

Comparative study of antioxidant effect from extract and fraction of 'Paku Atai Merah' ( Angiopteris ferox Coupel)

Paku Atai Merah tubers with the Latin name Angiopteris ferox Coupel have been used by the Dayak people as empirical treatment and have anticancer and antioxidant activity. The purpose of this study was to find out more the movement of extracts and fractions of Paku Atai Merah tubers in reducing free radicals using the total antioxidant capacity (TAC), CUPRAC, and Iron chelating methods. In this study, the sample used was the ethanol extract (EE) of A.ferox Copel and then partitioned using n-hexane (FHP), ethyl acetate (FEAP), and aqueous-ethanol (FEP) solvents. The effectiveness of the sample in reducing free radicals with various antioxidant assay methods. The results obtained from this study indicate that the extract and fraction of Paku Atai Merah tubers have good effectiveness as an antioxidant agent. The total antioxidant capacity (TAC) method showed that EAP had a total antioxidant capacity of 101.60 μM/mg QEAC compared to EE (44.62 μM/mg QEAC), FEAP (89.88 μM/mg QEAC), and FHP (81.21 μM/mg QEAC). In the CUPRAC method using gallic acid as a standard for comparison, the results obtained were EE (4.00 μM/mg GEAC), FHP (1.45 μM/mg GEAC), FEAP (8.66 μM/mg GEAC), and APA (8.72 μM/mg GEAC). The antioxidant activity using the chelating iron method in each sample of EE, HPA, EAP, and APA showed activity with IC50 values of 384 μg/mL, 387.41 μg/mL, 339.23 μg/mL, and 347.3 μg/mL. Based on the results obtained from this study, it can conclude that the extract and fraction of Paku Atai Merah tubers have an excellent antioxidant agent to develop as a food supplement

Improvements in the development of silicon nitride inserts using hybrid microwave energy for machining Inconel 718

Hybrid Microwave (HMW) sintering is becoming popular for heating ceramics, composites, metals and alloys. It is becoming a trendy research due to its capabilities in saving time, energy and money, increasing efficiency and productivity,improving mechanical and structural properties. Silicon Nitride (Si3N4) is widely used as a cutting insert for machining cast iron, hard steel and nickel based alloys. It is mass produced by traditional powder technology. This research aims to increase the tool life of the Silicon Nitride inserts by enhancing the mechanical and structural properties by using Hot Isostatic Pressing (HIP) at 1800°C and followed by hybrid microwave (HMW) post-sintering at 200°C for 10 minutes with the aid of Silicon Carbide powder as susceptor. Three different compositions (88%, 90% and 92% Si3N4) were synthesized in order to find the optimum composition using these techniques. Mechanical and structural properties were analyzed. The combination of HIP+HMW post sintering for just 10 minutes significantly enhanced the density (93-97%TD), hardness (18-22%), compressive strength (2-4%) and produced finer uniform grains particularly for 88% and 90% Si3N4 when compared with HIP samples without any post sintering effect. Hence, the 88% and 90% Si3N4 compositions produced by the combination of HIP+HMW post sintering are potentially suitable candidates for machining hard materials such as Inconel 718

The colour stability of natural blue dye extracted from Clitoria ternatea L. in poly(acrylamide-co-acrylic acid) coating film

Purpose: This paper aims to focus on a comparison study of the visible stability of natural blue dye consisting anthocyanin molecules extracted from Clitoria ternatea in coating films. Design/methodology/approach: The coating films were prepared by mixing the blue dye with poly(acrylamide-co-acrylic acid) in three different weight ratios. Samples were coded as 10PBA, 15PBA and 20PBA, where PBA is the abbreviation for poly acrylamide-co-acrylic acid, blue dyes and anthocyanin. The number at the beginning of each code represents the weight percentage of poly(acrylamide-co-acrylic acid) to natural blue dye. The mixtures were applied on separate glass substrates to form coating films. Another set of samples were prepared for the comparison study with a commercial acrylic clear coat (cc) applied on the surface of the 10PBA, 15PBA and 20PBA coating films. These coating films were coded 10PBAcc, 15PBAcc and 20PBAcc. The purpose of the clear coat is to observe how it affects the colour stability of the blue coating films with respect to time. All samples were exposed to the ultraviolet (UV) source, an 18 W Philips TL-D 18w/830 UV fluorescent lamp. The UV lamp was placed 15 cm above the surface of the samples for 35 days. The colour of the coatings was measured using CIE L*a*b* colour space coordinate. Findings: The results obtained show 10PBA and 10PBAcc have the highest colour stability after 35 days of exposure to UV light. The reflectivity of the coating films was also measured during exposure to UV lamp. Reflectivity measurements also showed that 10PBA and 10PBAcc coating films had the highest reflective stabilities. Research limitations/implications: The potential of using natural blue dye consisting anthocyanin in coating film to obtain high colour stability. Practical implications: The coating film developed in this work is suitable to be applied on glass substrates. Originality/value: The application of anthocyanin dye extracted from the Clitoria ternatea L. as a colourant in coating films. © 2019, Emerald Publishing Limited