Citric Acid and Microbial Phytase Inclusion in the Diet to Improve Utilization Phytate Phosporus and Growth of Broiler

Penelitian ini menggunakan anak ayam umur 3 sampai dengan 38 hari (180 ekor) dan 7 sampai dengan 42 hari (180 ekor). Ayam diberi ransum A, B, dan C yang berbahan dasar jagung (CSM) dan ransum E, F, dan G yang berbahan dasar gandum (WSM) yang diberi perlakuan penambahan steam pada suhu 1000C selama 10 menit. Semua ransum ditambah enzim fitase (SP-1002 ct) sebanyak 500 U/kg dan dibuat dalam bentuk pelet. Khusus ransum C dan G ditambah asam sitrat. Kandungan fosfor total ransum adalah 4,5 g/kg dan fosfor tersedia adalah 1,5 g/kg (defisien P). Bobot badan harian adalah 36, 34, dan 45 g/hari untuk ayam yang diberi ransum A, B, dan C dan 54, 46, dan 55 g/hari untuk ransum E, F, dan G. Deposisi fosfor total adalah 5,75; 5,36; dan 6,99 g berturut-turut untuk ransum A, B dan C dan 8,15; 6,90; dan 7,77 g untuk E, F, dan G. Penambahan asam sitrat dalam ransum CSM yang mengandung enzim fitase rendah mampu meningkatkan pertumbuhan dan deposisi fosfor. Pada ransum WSM, perlakuan panas menyebabkan penurunan aktifitas fitase dan penurunan ini tidak dapat digantikan dengan penambahan enzim fitase (microbial phytase) akan tetapi dapat digantikan dengan penambahan asam sitrat. Hasil penelitian ini dapat disimpulkan bahwa asam sitrat berpengaruh terhadap efisiensi enzim fitase (microbial phytase) dalam mendegradasi senyawa fitat di dalam saluran pencernaan

A method for measuring cooling air flow in base coolant passages of rotating turbine blades

Method accurately determines actual coolant mass flow rate in cooling passages of rotating turbine blades. Total and static pressures are measured in blade base coolant passages. Mass flow rates are calculated from these measurements of pressure, measured temperature and known area

Industry tests of NASA ceramic thermal barrier coating

Ceramic thermal barrier coating (TBC) system was tested by industrial and governmental organizations for a variety of aeronautical, marine, and ground-based gas turbine engine applications. This TBC is a two-layer system with a bond coating of nickel-chromium-aluminum-yttrium (Ni-16Cr-6Al-0.6Y, in wt. percent) and a ceramic coating of yttria-stabilized zirconia (ZrO2-12Y2O3, in wt. percent). Seven tests evaluated the system's thermal protection and durability. Five other tests determined thermal conductivity, vibratory fatigue characteristics, and corrosion resistance of the system. The information presented includes test results and photographs of the coated parts. Recommendations are made for improving the coating procedures

Flow measurement in base cooling air passages of a rotating turbine blade

The operational performance is decribed of a shaft-mounted system for measuring the air mass flow rate in the base cooling passages of a rotating turbine blade. Shaft speeds of 0 to 9000 rpm, air mass flow rates of 0.0035 to 0.039 kg/sec (0.0077 to 0.085 lbm/sec), and blade air temperatures of 300 to 385 K (80 to 233 F) were measured. Comparisons of individual rotating blade flows and corresponding stationary supply orifice flows agreed to within 10 percent

Potential use of ceramic coating as a thermal insulation on cooled turbine hardware

An analysis was made to determine the potential benefits of using a ceramic thermal insulation coating of calcia-stabilized zirconia on cooled engine parts. The analysis was applied to turbine vanes of a high temperature and high pressure core engine and a moderate temperature and low pressure research engine. Measurements made during engine operation showed that the coating substantially reduced vane metal wall temperatures. Evaluation of the durability of the coating on turbine vanes and blades in a furnace and engine were encouraging

Ceramic thermal-barrier coatings for cooled turbines

Coating systems consisting of a plasma sprayed layer of zirconia stabilized with either yttria, magnesia or calcia over a thin alloy bond coat have been developed, their potential was analyzed and their durability and benefits evaluated in a turbojet engine. The coatings on air cooled rotating blades were in good condition after completing as many as 500 two-minute cycles of engine operation between full power at a gas temperature of 1644 K and flameout, or as much as 150 hours of steady state operation on cooled vanes and blades at gas temperatures as high as 1644 K with 35 start and stop cycles. On the basis of durability and processing cost, the yttria stabilized zirconia was considered the best of the three coatings investigated

Effect of ceramic coating of JT8D combustor liner on maximum liner temperatures and other combustor performance parameters

The effect of ceramic coating of a JT8D combustor liner was investigated at simulated cruise and takeoff conditions with two fuels of widely different aromatic contents. Substantial decreases in maximum liner temperatures and flame radiation values were obtained with the ceramic-coated liner. Small reductions in exhaust gas smoke concentrations were observed with the ceramic-coated liner. Other performance parameters such as combustion efficiency and emissions of unburned hydrocarbons, CO, and NOx were not affected significantly. No deterioration of the ceramic coating was observed after about 6 hours of cyclic operation including several startups and shutdowns

Summary of NASA research on thermal-barrier coatings

A durable, two-layer, plasma-sprayed coating consisting of a ceramic layer over a metallic layer was developed that has the potential of insulating hot engine parts and thereby reducing metal temperatures and coolant flow requirements and/or permitting use of less costly and complex cooling configurations and materials. The investigations evaluated the reflective and insulative capability, microstructure, and durability of several coating materials on flat metal specimens, a combustor liner, and turbine vanes and blades. In addition, the effect on the aerodynamic performance of a coated turbine vane was measured. The tests were conducted in furnaces, cascades, hot-gas rigs, an engine combustor, and a research turbojet engine. Summaries of current research related to the coating and potential applications for the coating are included

Gas turbine ceramic-coated-vane concept with convection-cooled porous metal core

Analysis and flow experiments on a ceramic-coated-porous-metal vane concept indicated the feasibility, from a heat transfer standpoint, of operating in a high-temperature (2500 F) gas turbine cascade facility. The heat transfer and pressure drop calculations provided a basis for selecting the ceramic layer thickness (to 0.08 in.), which was found to be the dominant factor in the overall heat transfer coefficient. Also an approximate analysis of the heat transfer in the vane trailing edge revealed that with trailing-edge ejection the ceramic thickness could be reduced to (0.01 in.) in this portion of the vane

Citric Acid and Microbial Phytase Inclusion in The Diet to Improve Utilization Phytate Phosporus and Growth of Broiler

Penelitian ini menggunakan anak ayam umur 3 sampai dengan 38 hari (180 ekor) dan 7 sampai dengan 42 hari (180 ekor). Ayam diberi ransum A, B, dan C yang berbahan dasar jagung (CSM) dan ransum E, F, dan G yang berbahan dasar gandum (WSM) yang diberi perlakuan penambahan steam pada suhu 1000C selama 10 menit. Semua ransum ditambah enzim fitase (SP-1002 ct) sebanyak 500 U/kg dan dibuat dalam bentuk pelet. Khusus ransum C dan G ditambah asam sitrat. Kandungan fosfor total ransum adalah 4,5 g/kg dan fosfor tersedia adalah 1,5 g/kg (defisien P). Bobot badan harian adalah 36, 34, dan 45 g/hari untuk ayam yang diberi ransum A, B, dan C dan 54, 46, dan 55 g/hari untuk ransum E, F, dan G. Deposisi fosfor total adalah 5,75; 5,36; dan 6,99 g berturut-turut untuk ransum A, B dan C dan 8,15; 6,90; dan 7,77 g untuk E, F, dan G. Penambahan asam sitrat dalam ransum CSM yang mengandung enzim fitase rendah mampu meningkatkan pertumbuhan dan deposisi fosfor. Pada ransum WSM, perlakuan panas menyebabkan penurunan aktifitas fitase dan penurunan ini tidak dapat digantikan dengan penambahan enzim fitase (microbial phytase) akan tetapi dapat digantikan dengan penambahan asam sitrat. Hasil penelitian ini dapat disimpulkan bahwa asam sitrat berpengaruh terhadap efisiensi enzim fitase (microbial phytase) dalam mendegradasi senyawa fitat di dalam saluran pencernaan. Kata kunci: gandum, jagung, asam sitrat, enzim fitase, asam fita