Structural response of SSME turbine blade airfoils

Reusable space propulsion hot gas-path components are required to operate under severe thermal and mechanical loading conditions. These operating conditions produce elevated temperature and thermal transients which results in significant thermally induced inelastic strains, particularly, in the turbopump turbine blades. An inelastic analysis for this component may therefore be necessary. Anisotropic alloys such as MAR M-247 or PWA-1480 are being considered to meet the safety and durability requirements of this component. An anisotropic inelastic structural analysis for an SSME fuel turbopump turbine blade was performed. The thermal loads used resulted from a transient heat transfer analysis of a turbine blade. A comparison of preliminary results from the elastic and inelastic analyses is presented

Perancangan Kendali Pid Dengan Model Process Reaction Curve Pada Showcase Jamur Merang

Jurnal ini menyajikan sebuah model empiris untuk mensimulasikan karakteristik system pendingin untuk jamur merang. Model matematika didasarkan pada hasil pengukuran suhu. Parameter, seperti, Gain (K), waktu tunda (θ), dan waktu konstan (τ) diperoleh dari nilai-nilai eksperimental. System pendingin dirancang dengan menggunakan metode kurva reaksi proses, sedangkan pengontrol PID dengan metode korelasi Ciancone. Kontrol PID berhasil diterapkan, hal ini dapat dilihat dari tidak adanya kesalahan tunak, respon sistem yang lebih cepat mencapai set-point, overshoot dan undershoot tidak terlalu jauh dari nilai masukan

Normal soaking extraction (NSE) of rotenone from Derris elliptica

Derris elliptica or the tuba plant contains rotenone, bio-active compound known that has the potential to be used as bio-pesticide. Bio-pesticide is the best-known alternative bio-pesticide which has the potential to replace the use of conventional pesticides, as it is more environmentally friendly. The main objective of the paper is to obtain the best extraction solvent for optimizing the yield in rotenone extraction. Rotenone was extracted from Derris root using three different parts of roots and three types of solvent in Normal Soaking Extraction (NSE). The types of Derris roots are: (1) Fine root (2) Coarse root (3) Stem. The three types of solvent system are: (1) Acetone 95 % (v/v), (2) Chloroform 99.9 % (v/v) and (3) a mixture of ethanol: H2O (9:1) added with oxalic acid (1mg/ml). The liquid crude extracts were further cleaned up to remove the fine debris of roots. The presence of rotenone was confirmed using qualitative analysis Thin Layer Chromatography (TLC) and thereupon the determination of rotenone content was carried out using High Performance Liquid Chromatography (HPLC). From the results obtained, it was found that the Normal Soaking Extraction (NSE) using acetone 95 % (v/v) was the best method to extract the highest yield of rotenone; 1.14 % (w/w)

Scattering length for helium atom-diatom collision

We present results on the scattering lengths of ^4He--^4He_2 and ^3He--^4He_2 collisions. We also study the consequence of varying the coupling constant of the atom-atom interaction.Comment: Contribution to Proceedings of the International Workshop ``Critical Stability of Few-Body Quantum Systems'' (Dresden, October 17--22, 2005

Origin and stability of the dipolar response in a family of tetragonal tungsten bronze relaxors

A new family of relaxor dielectrics with the tetragonal tungsten bronze structure (nominal composition Ba6M3+Nb9O30, M3+ = Ga, Sc or In) were studied using dielectric spectroscopy to probe the dynamic dipole response and correlate this with the crystal structure as determined from powder neutron diffraction. Independent analyses of real and imaginary parts of the complex dielectric function were used to determine characteristic temperature parameters, TVF, and TUDR, respectively. In each composition both these temperatures correlated with the temperature of maximum crystallographic strain, Tc/a determined from diffraction data. The overall behaviour is consistent with dipole freezing and the data indicate that the dipole stability increases with increasing M3+ cation size as a result of increased tetragonality of the unit cell. Crystallographic data suggests that these materials are uniaxial relaxors with the dipole moment predominantly restricted to the B1 cation site in the structure. Possible origins of the relaxor behaviour are discussed.Comment: Main article 32 pages, 8 figures; Supplementary data 24 pages, 4 figure

Ferromagnetic Ga₁ˍₓ Mnₓ As produced by ion implantation and pulsed-laser melting

We demonstrate the formation of ferromagneticGa₁ˍₓMnₓAsfilms by Mn ion implantation into GaAs followed by pulsed-laser melting. Irradiation with a single excimer laser pulse results in the epitaxial regrowth of the implanted layer with Mn substitutional fraction up to 80% and effective Curie temperature up to 29 K for samples with a maximum Mn concentration of x≈0.03. A remanent magnetization persisting above 85 K has been observed for samples with x≈0.10, in which 40% of the Mn resides on substitutional lattice sites. We find that the ferromagnetism in Ga₁ˍₓMnₓAs is rather robust to the presence of structural defects.The work at the Lawrence Berkeley National Laboratory was supported by the Director, Office of Science, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098. The work at Harvard was supported by NASA Grant No. NAG8-1680. One of the authors ~M.A.S.! acknowledges support from an NSF Graduate Research Fellowship

Pengaruh Laju Aliran Air terhadap Temperatur Sistem Mesin Pengkondisian Udara Hibrida Menggunakan Kondensor Dummy Tipe Helical Coil (Diameter Pipa 1/4") sebagai Water Heater dengan Pembebanan 2000 Watt

Energy saving is one way to reduce energy USAge without decreasing the results. This way can be obtained byusing the hybrid air conditioning. Other than energy saving, the hybrid air conditioning also can reduce theeffects of global warming by condenser waste heat recovery. This research aims to investigate the effect ofvariations flow rate in water heater tank to the system temperatures of hybrid air conditioning using helical coiltype of dummy condenser with 1/4˝ diameter of copper pipe. Experimental method is used in this research. Thetest was conducted with several water flow rate variations (1/3, 2/3, and 3/3 valve openings) and using coolingload of 2000 Watt as residential cooling load simulation. The result showed that the water temperature in waterheater tank was changed in every water flow rate variations. The highest water temperature was obtained at39.77˚C for 0 valve opening (full-closed valve), but, the lowest water temperature was obtained at 32.57˚C in3/3 valve opening (full-open valve)