Xains Info: August 2008

Design of the Mechanical Parts for the Neutron Guide System at HANARO

The research reactor HANARO (High-flux Advanced Neutron Application ReactOr) in Korea will beequipped with a neutron guide system, in order to transport cold neutrons from the neutron source to the neutronscattering instruments in the neutron guide hall near the reactor building. The neutron guide system of HANAROconsists of the in-pile plug assembly with in-pile guides, the primary shutter with in-shutter guides, the neutron guides inthe guide shielding room with dedicated secondary shutters, and the neutron guides connected to the instruments in theneutron guide hall. Functions of the in-pile plug assembly are to shield the reactor environment from nuclear radiationand to support the neutron guides and maintain them precisely oriented. The primary shutter is a mechanical structure tobe installed just after the in-pile plug assembly, which stops neutron flux on demand. This paper describes the design ofthe in-pile assembly and the primary shutter for the neutron guide system at HANARO. The design of the guideshielding assembly for the primary shutter and the neutron guides is also presented.Keywords: neutron guide, in-pile plug, primary shutter.PACS: 61.05.fg. J. W. Shi.q, Y. G. Cho, S. J. Cho and J. S RyuKorea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon 305-353, Korea

Dislocations in P-MBE Grown ZnO Layers Characterized by HRXRD and TEM

We have characterized dislocations in ZnO layers grown on c-sapphire (a-Ah03) by plasma-assistedmolecular-beam epitaxy (P-MBE) with and without MgO buffer layer. Zno without MgO buffer was grown three-dimensionally(3D), while ZnO with MgO buffer was grown two-dimensionally (2D). Mosaic spread (tilt and twistangles), types and density of dislocations in the layers were studied by both high-resolution X-ray diffraction (HRXRD)and transmission electron microscopy (TEM). HRXRD experiments reveal that screw dislocation densities in the ZnOlayer are 8.1 x loBcm-2 and 6.1 x 105 cm,2,for Zno with and without MgO buffer, respectively, while edge dislocationdensities are 1.1x 1010 cm,2 and 1.3 x 105 cm,2, for ZnO with and without MgO buffer, respectively. HRXRD and TEMdata showed the same result that the major dislocations in the ZnO layers are edge type dislocations running along c-axis.Therefore, HRXRD technique can be applied to characterize dislocations in ZnO layers.Keywords: ZnO, dislocations, HRXRD, TEMPACS: 81.05.Dz, 61.72.Lk, 61.72.Dd, 68.37.Lp. A.Setiawan, I. Hamidah, S. Maryanto, S. Aisyah, and T. YaoIDepartment of Mechanical Engineering and Graduate School of Science EducationIndonesia University of Education, Setiabudhi 229 Bandung 40154, Indonesia2Geological Research and Development Centre, Diponegoro 57 Bandung 40122, Indonesia3Department of Chemistry Education Indonesia University of EducationSetiabudi 229 Bandung 40154, Indonesia4Center for Interdisciplinary Research, Tohoku University Aramaki, Aoba-ku, Sendai, 980-8578, Japan

Powder Diffraction Studies of Phase Transitions in Manganese Perovskites

The results of recent structural studies of some Manganese perovskites are presented, in particular oxides inthe system Cal_xSrxMn03 and SrRllo.sMno.503' In the fIrst series we fIrstly show the power of synchrotron X-ray powderdiffraction to refme accurate and precise structures for oxides containing fIrst row transition metals and then show thepresence of a direct orthorhombic Pbnm to tetragonal 14/mcm transition associated with the tilting of the Mn06octahedra. The inclusion of a heavier second row transition metal reduces the precision of the structure, however thedetails of the tetmgonal to cubic phase transition in SrRllo.sMno.503 are still established.Keywords: Perovskite, Phase Transition, Synchrotron X-ray Powder Diffraction, Jahn- Teller DistortionPACS: 61.05.Cp; 61.50.Ks; 61.66.Fn. B. J. KennedySchool of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia

Pulsed Neutron Powder Diffraction for Materials Science

The accelerator-based neutron diffraction began in the end of 60's at Tohoku University which was succeeded
by the four spallation neutron facilities with proton accelerators at the High Energy Accelerator Research Organization (Japan), Argonne National Laboratory and Los Alamos Laboratory (USA), and Rutherford Appleton Laboratory (UK). Since then, the next generation source has been pursued for 20 years, and IMW-class spallation neutron sources will be appeared in about three years at the three parts of the world: Japan, UK and USA. The joint proton accelerator project (J-PARC), a collaborative project between KEK and JAEA, is one of them. The aim of the talk is to describe about J-PARC and the neutron diffractometers being installed at the materials and life science facility of J-PARC. The materials and life science facility of J-PARC has 23 neutron beam ports and will start delivering the first neutron beam of 25 Hz from 2008 May. Until now, more than 20 proposals have been reviewed by the review committee, and accepted proposal groups have started to get fund. Those proposals include five poly crystalline diffractometers: a super high resolution powder diffractometer (SHRPD), a 0.2 %-resolution powder diffractometer of Ibaraki prefecture (IPD), an engineering diffractometers (Takumi), a high intensity S(Q) diffractometer (VSD), and a high-pressure dedicated diffractometer. SHRPD, Takumi and IPD are being designed and constructed by the joint team of KEK, JAEA and Ibaraki University, whose member are originally from the KEK powder group. These three instruments are expected to start in 2008. VSD is a super high intensity diffractometer with the highest resolution of Mid = 0.3%. VSD can measure rapid time-dependent phenomena of crystalline materials as well as glass, liquid and amorphous materials. The pair distribution function will be routinely obtained by the Fourier transiformation of S(Q) data. Q range of VSD will be as wide as 0.0IA-1 Q 100A-1. IPD is fully funded by Ibaraki prefecture for the promotion of new industries based on advanced science and technologies. It is for the first time in neutron facilities in Japan that a prefecture owns neutron instruments as well as neutron beam will be provided widely to industrial users. To make it successful, the user system is quite important because those users are expected to use IPD like chemical analyzers in their materials development process. Based on questionnaire data to several hundreds industries, IPD is designed as a versatile diffractometer including texture measurement, small angle scattering and total scattering as well as usual powder diffraction. IPD covers d range 0.15 d (A) 4 with Mid = 0.15 %, and covers 4 d (A) 60 with gradually changing resolution. Q range of IPD will be as wide as 0.0IA-1 Q 50A-1 to be utilized for varieties of structures: local structure, nano structure and crystal structure analyses. Typical measuring time for the typical Rietveld-quality data is several minutes with the sample size of laboratory X-ray: 0.4 cc. SHRPD is designed to be the world highest resolution with Mid = 0.03% without sacrificing intensity. The combination of the high quality data from HRPD and their high-precision analysis gives us information on tiny structural changes which have been overlooked. After careful examination with the moderator group five years ago, we have decided to develop a high-resolution & good SIN moderator to achieve the 0.03 % resolution within 100 m flight path. This development was almost successful up to now. Instrumental simulation and radiation analysis were almost completed. The d range 0.5 d (A) 4 with Mid = 0.03 %, and covers 4 d (A) 45 with gradually changing resolution. Takumi is the first priority instrum_entin IAEA for stress mapping inside structure materials with the highest resolution of Mid = 0.2% (corresponding to 105 to 106 strain precision). The typical gauge volume will be 1 mm3. JED has transmission radiography detectors to support stress mapping. Software group is planning so that basic software to cover data acquisition and data treatment should be common. Since 1 Gbyte data are typically obtained for single experiment in an instrument, the basic software is quite important. International TV conference between ISIS, lPNS, SNS has been held every month to exchange information on each development. KEK developed manyo-lib to help basic analysis. ArJalysis software development including powder diffraction is strongly related with the activity of the software group. However, users of IPD will be from various field of science and their background is different. It should cover wide topics and help both beginners and well-trained users. We have started with neutron intensity database, peak-search software, peak-match software, pattern simulation, whole pattern fitting, PDF and RDF analysis, and now start coding Rietveld software. Keywords: Pulsed neutron, powder diffractometer, crystalline, glass, amorphous. T. Kamiyama Materials and Lift Science Facility, J-PARC Center, High Energy Accelerator Research Organization, Tsukuba, lbaraki 305-0801 JAPAN

Fractal Studies on Titanium-Silica Aerogels using SMARTer

Power-law scattering approximation has been employed to reveal the fractal structures of solid-state titanium-silicaaerogel samples. All small-angle neutron scattering (SANS) measurements were performed using 36 meters SANSBATAN spectrometer (SMARTer) at the neutron scattering laboratory (NSL) in Serpong, Indonesia. The mass fractaldimension of titanium-silica aerogels at low scattering vector q range increases from -1.4 to -1.92 with the decrease ofacid concentrations during sol-gel process. These results are attributed to the titanium-silica aerogels that are growing tomore polymeric and branched structures. At high scattering vector q range the Porod slope of -3.9 significantly down to-2.24 as the roughness of particle surfaces becomes higher. The cross over between these two regimes decreases from0.4 to 0.16 nm,l with the increase of acid concentrations indicating also that the titanium-silica aerogels are growing.Keywords: SANS, aerogels, fractals, power-law scatteringPACS: 25.40. Dn, 82.70. Gg, 83.85. Hf. E. Giri Rachman Putral, A. lkram\ Bharotol, E. Santosol, T. Chiar Fang2,N. Ibrahim2, A. Aziz Mohamed31 Neutron Scattering Laboratory, BATAN, Kawasan Puspiptek Serpong, Tangerang 15314, Indonesia2 Department of Physics, Faculty of Science Universiti Teknologi Malaysia (UTM), 81310 Skudai, lohor, Malaysia3 Materials Technology Group, Industrial Technology Division Agensi Nuklear Malaysia, 43000 Kajang, Malaysia

J-PARC and Prospective Neutron Science

J-PARC is interdisciplinary facility with high power proton accelerator complex to be completed by 2008after 7 years construction. Materials-Life Science Facility (MLF) will be very intensive pulsed neutron and muonfacility at IMW of the accelerated proton power. The neutron peak flux will be as high as several hundred times ofexisting high flux reactors. It is highly expected that new science will be opened up by using MLF. In the presentation Iwill explain the present status of J-PARC, strategy of user programme and prospective neutron science to be performedwith it.Keywords: Proton accelerator, pulsed neutron, muon. M. AraiJ-PARC Centre, Japan Atomic Energy Agency,Tokai, lbaraki 319-1195, Japan

SANS and SAXS Study of Block and Graft Copolymers Containing Natural and Synthetic Rubbers

Small-angle neutron scattering (SANS) and small-angle X-ray scattering (SAXS) are excellent techniques tostudy nano-scale concentration fluctuations in the two-component polymer systems such as block and graft copolymersand polymer blends. The miscibility, phase transitions, microphase-separated structures and interface thicknesses wereinvestigated by SANS and SAXS for the block and graft copolymers, which at least contain natural or synthetic rubberas one component.Keywords: Block copolymer, graft copolymer, SAXS, SANSPACS: 61.05.cf, 61.05.fg, 61.41.+e. H. HasegawaDepartment of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan

Membrane Structure Studies by Means of Small-Angle Neutron Scattering (SANS)

The basic model for membrane structure - a lipid bilayer with imbedded proteins - was formulated 35 yearsago, however the detailed structure is still under active investigation using a variety of physical, chemical andcomputational techniques. Every biologically active cell is encapsulated by a plasma membrane with most cells alsoequipped with an extensive intracellular membrane system. The plasma membrane is an important boundary between thecytoplasm of the cell and the external environment, and selectively isolates the cell from that environment. Passivediffusion and/or active transport mechanisms are provided for water, ions, substrates etc. which are vital for cellmetabolism and viability. Membranes also facilitate excretion of substances either as useful cellular products or as waste.Despite their complexity and diverse function, plasma membranes from quite different cells have surprisingly similarcompositions. A typical membrane structure consists of a phospholipid bilayer with a number of proteins scatteredthroughout, along with carbohydrates (glycoproteins), glycolipids and sterols. The plasma membranes of mosteukaryotic cells contain approximately equal weights of lipid and protein, which corresponds to about 100 lipidmolecules per protein molecule. Clearly, lipids are a major constituent and the study of their structure and function inisolation provides valuable insight into the more complex intact multicomponent membrane. The membrane boundprotein is the other major constituent and is a very active area of research for a number of reasons including the fact thatover 60% of modern drugs act on their receptor sites. The interaction between the protein and the supporting lipidbilayer is clearly of major importance. Neutron scattering is a powerful technique for exploring the structure ofmembranes, either as reconstituted membranes formed from well characterised lipids, or as intact membranes isolatedfrom selected biological systems. A brief summary of membrane structure will be followed by an outline of the neutronscattering techniques used to understand membrane structure and dynamics. The emphasis will be on the small angleneutron scattering technique since there is a very powerful instrument at Serpong, however brief mention of othertechniques will be included to demonstrate how a multidisciplinary approach is usually requiredKeywords: neutron scattering, membrane structure, biology, SANS. R. B. Knottl,21Bragg Institute, ANSTO, Private Mail Bag, Menai NSW 2234, Australia2CSIRO Minerals, Box 312, Clayton South VIC 3169, Australia

Opportunities for Materials Science and Biological Research at the OPAL Research Reactor

Neutron scattering techniques have evolved over more than Yo century into a powerful set of tools fordetennination of atomic and molecular structures. Modem facilities offer the possibility to detennine complex structuresover length scales from -D.l nm to -500 nm. They can also provide infonnation on atomic and molecular dynamics, onmagnetic interactions and on the location and behaviour of hydrogen in a variety of materials. The OPAL ResearchReactor is a 20 megawatt pool type reactor using low enriched uranium fuel, and cooled by water. OPAL is amultipurpose neutron factory with modem facilities for neutron beam research, radioisotope production and irradiationservices. The neutron beam facility has been designed to compete with the best beam facilities in the world. After sixyears in construction, the reactor and neutron beam facilities are now being commissioned, and we will commencescientific experiments later this year. The presentation will include an outline of the strengths of neutron scattering and adescription of the OPAL research reactor, with particular emphasis on it's scientific infrastructure. It will also provide anoverview of the opportunities for research in materials science and biology that will be possible at OPAL, andmechanisms for accessing the facilities. The discussion will emphasize how researchers from around the world canutilize these exciting new facilities.Keywords: Neutron beam facilities, research reactor, atomic and molecular dynamics. S. 1. KennedyThe Bragg Institute, Australian Nuclear Science and Technology Organisation,Menai NSW 2234, Australia

Neutron Protein Crystallography: Beyond the Folding Structure

Neutron diffraction provides an experimental method of directly locating hydrogen atoms in proteins, atechnique complementary to ultra-high-resolution X-ray diffraction. A neutron diffractometers for biologicalmacromolecules has been constructed in Japan, and it has been used to determine the crystal structures of proteins up toresolution limits of 1.5-2.5 A. Results relating to hydrogen positions and hydration patterns in proteins have beenobtained from these studies. Examples include the geometrical details of hydrogen bonds, the role of hydrogen atoms inenzymatic activity, CH3 configuration, HID exchange in proteins and oligonucleotides, and the dynamical behavior ofhydration structures, all of which have been extracted from these structural results and reviewed.Keywords: Neutron, protein, crystallography, hydrogen, hydration, I-PARC, SNSPACS: 83.85.Hf, 87.15.-v

Oxidation of Ni and Ni-5% W

Oxidation of cube textured (100) 001 Ni and Ni-5%W foils were studied in order to verify ifNiO surfacelayer could be fonned on Ni-W similar to that Ni. The principle aim of this study is to prescribe the basic conditions forgrowing a compact, adherent, smooth, and cube texture NiO suitable to be used as a buffer layer in coated conductor,high temperature superconductor architecture. It was found that for Ni 30Jlm thick (002) NiO were fonned at oxidationtemperature of 1250 ± lOoe in air for 60 min. Under the same oxidation condition, (002) NiO with duplex-typemorphology was fonned on Ni-5%W which reduces the mechanical integrity of the sample. Furthennore, due to oxygendiffusion during the oxidation process, spherical NiW04 fonned inside the Ni-W substrate.Keywords: Oxidation, nickel, nickel oxide, nickel-tungsten, rolling assisted biaxially textured substratePACS: 74.72.Bk Y, 81.65.Mq. Z. Lockman\ M. H. Jamaluddin\ R. Nast2I School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia,14300 Nibong Tebal,Penang, Malaysia, 2Forschungszentrum Karlsruhe, Institut fur Technische Physik, Karlsruhe, Germany

Dynamical Scaling, Fractal Morphology and Small-angle Scattering

When a system with continuous symmetry is quenched instantly to a broken symmetry state, new phases oftopological defects appear in an otherwise homogeneous medium of continuous symmetry. The phenomenon of newphase formation is a representative example of first order transition. The phenomenon is of immense interest as anexample of a highly nonlinear process far from equilibrium. The second phase grows with time and in late stages alldomain sizes are much larger than all microscopic lengths. In the large time limit, the new phase forming systemsexhibit self-similar growth pattern with dilation symmetry, with time dependent scale, and scaling phenomenon.Extensive investigations on dynamical scaling phenomenon have been carried out so far for Euclidean systems. Thequestion arises about the validity of the scaling laws for dynamical systems in non-Euclidean fractal geometry. Some ofthe questions, arising purely because of the geometrical constraints in the physical systems and others on experimentalobservations, are posed here.Keywords: Dynamical scaling, fractals, small-angle scatteringPACS: 64.75.+g, 64.90.+b, 61.43.Hv, 61.50.Ks. S. MazumderSolid State Physics DivisionBhabha Atomic Research Centre, Trombay, Mumbai 4000 85, India

Thermal Stress Behavior of Micro- and Nano-Size Aluminum Films

In-situ observation of thermal stresses in thin films deposited on silicon substrate was made by X-ray andsynchrotron radiation. Specimens prepared in this experiment were micro- and nano-size thin aluminum films with andwithout passivation film. The thickness of the film was 1 micrometer for micro-size films and 10, 20 and 50 nanometerfor nano-size films. The stress measurement in micro-size films was made by X-ray radiation whereas the measurementof nano-size films was made by synchrotron radiation. Residual stress measurement revealed tensile stresses in all as-depositedfilms. Thermal stresses were measured in a series of heating- and cooling-stage. Thermal stress behavior ofmicro-size films revealed hysteresis loop during a heating and cooling process. The width of a hysteresis loop was largerin passivated film that unpassivated film. No hysteresis loops were observed in nano-size films with Si02 passivation.Strengthning mechanism in thin films was discussed on a passivation film and a film thickness.Keywords: Thermal stress, in-situ observation, aluminum film. X-ray measurement, synchrotron radiation. T. Hanabusal, M. Nishida2, K. Kusaka3IInstitute of Technology and Science, the University ofTokushima, Tokushima, Japan2Department of Mechanical Engineering, Kobe City Collage of Technology, Kobe, Japan3Institute ofTeclmology and Science, the University ofTokushima, Tokushima, Japan

Structure and Function of Glucansucrases

Glucansucrases are relatively large (-160 kDa) extracellular enzymes produced by lactic acid bacteria. Usingsucrose as a substrate they synthesize high molecular mass glucose polymers, called a-glucans, which allow the bacteriato adhere to surfaces and create a biofilm. The glucan polymers are of importance for the food and dairy industry asthickening and jellying agents. An overview is given of the current insights into the structure and functioning of theseand related enzymesKeywords: glucansucrase; amylosucrase; crystal structure; catalysis; catalytic mechanism.PACS: 87.l7.Uv. B. W. Dijkstra and A. VujiCi6-ZagarLaboratory of Biophysical Chemistry, University ofGroningenNijenborgh 4,9747 AG Groningen, The Netherlands

Neutron Reflectometry as a Surface Probe: A Personal Perspective

Development of neutron reflectometry has enabled neutron scattering laboratories worldwide to makeimportant contributions to the study of surfaces, interfaces and thin-films. As a result, neutron scattering has become aninvaluable research tool for the scientific disciplines that did not traditionally use neutrons for research as recently as 20years ago. At Chalk River (Canada), one discipline with which we have formed a close affiliation is electrochemistry.Our decision in the early 1990s to reach out to this potential user community was based on the fact that Canada hasmany researchers active in corrosion science. The virtue of this affiliation is best demonstrated in our experimentswhere reflectometry is performed simultaneously on the sample being investigated with electro-impedance spectroscopy,a standard electrochemical technique. The two methods in combination have led to the results that would have otherwisebeen missed or wrongly interpreted.Keywords: Neutron reflectometry, electro-impedance spectroscopy, corrosion. Z. TunCanadian Neutron Beam Centre, National Research Council Canada, Chalk River LaboratoriesChalk River, Ontario, Canada KOJ JJO

Magnetic Excitations in Transition-metal Oxides Studied by Inelastic Neutron Scattering

Inelastic neutron scattering using a triple axis spectrometer is a very efficient tool to analyze magneticexcitations. We will discuss several recent experiments on transition-metal oxides where orbital degrees of fIeedom playan important role. Different kinds of experimental techniques including longitudinal and spherical polarization analysiswere used in order to determine not only magnon frequencies but also polarization vectors. In layered ruthenates bandsof different orbital character contribute to the magnetic excitations which are of both, ferromagnetic andantiferromagnetic, character. The orbital dependent magnetic excitations seem to play different roles in thesuperconducting pairing as well as in the metamagnetism . In manganates the analysis of the magnon dispersion in thecharge and orbital ordered phase yields direct insight into the microscopic coupling of orbital and magnetic degrees offreedom and helps understanding, how the switching between metallic and insulating phases in manganates may occur.In multiferroic TbMn03 the combination of our polarized neutron scattering results with the infrared measurementsidentifies a soft collective excitation of hybridized magnon-phonon character.Keywords: Inelastic neutron scattering, magnetic excitations. M. BradenInstitute of Physics, University of Cologne, Germany

Synthesis and Structural Properties of Fe Doped ao.SSrO.2GaO.sMgo.203-o(LSGM) as Solid Electrolyte for Solid Oxide Fuel Cell

LIogSrO.2G!IogMgo203.~(LSGM) is perovskite base oxide material, which exhibits high ion oxygenconductivity, and can it be applied as electrolyte material in solid oxide fuel cell (SOFC). In order to reduce the fuel celloperational temperature, high ionic conductivity must be obtained at lower temperature. High ionic conductivity can beachieved by introducing impurity or defect into material. Doping with Fe for Mg site is expected to increase oxygen ionconductivity in LSGM, since Fe atom has higher valence number (+3) compared with Mg (+2). The LSGM and LSGMF(L!IogSro2G!IogMgo2.xFCx03.~with x = 0, 0.05, 0.1, 0.15) perovskite structure were synthesized by solid state reactiontechnique at high temperature and it was sintered at 1350 °C for 24 hours. Crystal structures were analyzed using X-raysdiffractometer and refined using Rietica program. The lattice parameters were determined using Le Bail method in cubicstructure with space group of Pm3m. The cell parameters for L!IogSro2G!IosMgo2-xFCx03_~(with x = 0, 0.05, 0.1, 0.15)were a = 3.92023(1) A, a = 3.91056(7) A, a = 3.89459(9) A, and a = 3.92463(0) A. Scanning Electron Microscope(SEM) and Energy Dispersive X-Ray Spectroscopy (EDX) was used to study the grain morphology and elementscomposition of the LSGMF in order to analyze the effect of Fe substitution.Keywords: Perovskite, Solid Oxide Fuel Cell, LSGM dope-Fe, Solid State Reaction, X-rays diffractionPACS: 61.10.Nz, 61.43.Gt, 66.1O.Ed. Rusmiati, B. Prijamboedi, and IsmunandarInorganic and Physical Chemistry Research Divisian,Facuity afMathematics and Natural Sciences,Institut Telmalagi Bandung, Jl. Ganesha 10, Bandung, INDONESIA

Effect of Sintering Ternperature on the Synthesis of High Purity Cordierite

Cordierite is silicate material widely used in ceramic industry. The effect of sintering temperature to theproperties of cordierite by sol gel method was studied with utilizing magnesium nitrate, aluminum nitrate, ethanol, andtetraethyl orthosilicate (TEOS) as starting materials. Gels are dried and sintered at different temperature (lOOO°C,1200°C, 1300°C and 1350°C) then characterized by varies analysis techniques. XRD analysis shows that spinel, 11-cordierite and cristobalite are formed at 1000 °C which spinel as predominant phase. At 1200 DC,l1-cordieriteoccured aspredominant phase, spinel, sapphirine and cristobalite are formed as minor phases. It also confirmed that high purity a-cordieriteformed at 1300 °C and clearly observed at 1350 DC.Result of EDX analysis proved that magnesium,aluminum, silicon and oxygen was existed in the cordierite.Keywords: Cordierite, sol-gel, TEOS, coefficient thermal expansion.PACS: 81.07.-b. Y. P. Chao, T. Y. Chow and H. MohamadSchool of Material and Mineral Resources Engineering, Universiti Sains Malaysia,Engineering Campus 14300 Nibong Tebal, Pulau Pinang, Malaysia

X-Ray Powder Diffraction (XRD) Studies on Kenaf Dust Filled Chitosan Bio-composites

Kenaf dust filled chitosan bio-composites with various compositions of kenaf dust (i.e. 7%, 14%, 21 % and28%) were prepared using solution casting technique. The degree of relative crystallinity of the bio-composites wasdetermined using XRD method. Two distinguishable crystalline peaks were observed in the 28 range of 5 to 40° whichindexed as 020 and 110 respectively. It was noted that the maximum peak of intensity at 020 crystalline peak increasedwith addition of kenaf dust as well as the second maximum peak of intensity at 110. Consequently, Fourier TransformInfrared (FTIR) analysis was done to investigate the interaction between kenaf dust and chitosan matrix. From FTIRanalysis, corresponding peak of chitosan was detected at wavelength of 3233.2cm-1 indicated that there existintermolecular interactions between kenaf dust and chitosan matrix. These results highlighted that there are greaterintermolecular forces formed in chitosan with addition of kenaf dust. Intermolecular forces were attributed to theformation of inter and intra hydrogen bonding between chitosan polymer and cellulosic kenaf dust filler.Keywords: Chitosan, X-ray diffraction, FTIRPACS: 61.10.Nz. N. Muhd Julkapli and H. Md AkilSchool of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia,14300 Nibong Tebal, Pulau Pinang, Malaysia

Dynamical Temperature Study for Spin-Crossover

Making use of the Rugh's dynamical and micro-canonical approach to temperature, we study theclassicalmodel of three dimensional spin-crossover compounds. These compounds are characterized by magnetic ions that can bein a high-spin or low-spin state. We consider the case of diamagnetic low-spin state which are appropriate for Fe-Cocompounds. The values of the magnetization average and fraction of high-spinllow-spin are studied over a wide range ofvalues for the system size, temperature, magnetic field, nearest neighbor coupling and exchange interaction. We alsoaddress metastability according to the relative values of interaction parameters and the phase diagram of the model.Keywords: Phase transition, dynamical temperature, spin crossover.PACS: 05.1O.Ln; 05.50.+q; 07.05.Tp; 75.10.Hk; 75.60.Ej. W. B. Nurdinl and K. D. Schotte21Laboratory of Theoretical and Computer, Department of Physics, FMIPA,University Hasanuddin, Makassar 90245, Indonesia2Fachbereich Physik, Freie Universitaet, Berlin 13353, Germany

Membrane Structure Studies by Means of Small-Angle Neutron Scattering (SANS)

The basic model for membrane structure - a lipid bilayer with imbedded proteins - was formulated 35 yearsago, however the detailed structure is still under active investigation using a variety of physical, chemical andcomputational techniques. Every biologically active cell is encapsulated by a plasma membrane with most cells alsoequipped with an extensive intracellular membrane system. The plasma membrane is an important boundary between thecytoplasm of the cell and the external environment, and selectively isolates the cell from that environment. Passivediffusion and/or active transport mechanisms are provided for water, ions, substrates etc. which are vital for cellmetabolism and viability. Membranes also facilitate excretion of substances either as useful cellular products or as waste.Despite their complexity and diverse function, plasma membranes from quite different cells have surprisingly similarcompositions. A typical membrane structure consists of a phospholipid bilayer with a number of proteins scatteredthroughout, along with carbohydrates (glycoproteins), glycolipids and sterols. The plasma membranes of mosteukaryotic cells contain approximately equal weights of lipid and protein, which corresponds to about 100 lipidmolecules per protein molecule. Clearly, lipids are a major constituent and the study of their structure and function inisolation provides valuable insight into the more complex intact multicomponent membrane. The membrane boundprotein is the other major constituent and is a very active area of research for a number of reasons including the fact thatover 60% of modern drugs act on their receptor sites. The interaction between the protein and the supporting lipidbilayer is clearly of major importance. Neutron scattering is a powerful technique for exploring the structure of membranes, either as reconstituted membranes formed from well characterised lipids, or as intact membranes isolatedfrom selected biological systems. A brief summary of membrane structure will be followed by an outline of the neutronscattering techniques used to understand membrane structure and dynamics. The emphasis will be on the small angleneutron scattering technique since there is a very powerful instrument at Serpong, however brief mention of othertechniques will be included to demonstrate how a multidisciplinary approach is usually requiredKeywords: neutron scattering, membrane structure, biology, SANS. R. B. Knottl,21Bragg Institute, ANSTO, Private Mail Bag, Menai NSW 2234, Australia2CSIRO Minerals, Box 312, Clayton South VIC 3169, Australia

The Effect of Sintering Soaking Time on Microstructural and Properties of CaCu3Mn4012System

The synthesis of CaCu~n4012 (CCMO) has been accomplished via solid-state reaction. The mixture wascalcined at 850 DC for 12 hours. Temperature of 1090 °c has been chosen with 6 differ soaking time ranging from 1 hourto 24 hours. The CCMO formation was confirmed using X-ray diffraction (XRD). The microstructure analysis wascarried out using field emission scanning electron microscopy (FESEM), while electrical properties have been studiedusing AutoLab POSTAT 30 Frequency Analyser. Results shows that differ soaking time for sintering introduce uniqueproperties for CCMO. Microstructural analysis reveal that soaking time more than 12 hours produce grains with almostuniform shape. The physical densification of the sintered pellets promotes the creation of new conduction channels andincrease of intergrain effective area for transport current under conductivity properties. Results for bulk conductivityvary from 0.2148 x 10-4to 0.5825 X 10-4Stcm.Keywords: CaCu3Mil4012'solid-state reaction, bulk conductivityPACS: 81.05.-t. A.R. Mohd Warikh1, A.Z. Ahmad Zahirani2, S.D. Hutagalung2, A. Zainal Ahmad2IDepartment of Engineering Material, Faculty of Manufacturing Engineering,Universiti Teknikal Malaysia Melaka, Locked Backed 1200, Ayer Keroh, 75450 Melak, Malaysia. 2 School of Materials and Mineral Resources Engineering, Engineering Campus, University Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia

Phase Compositions of Self Reinforcement AhOfCaAI12019 Composite using X-ray Diffraction Data and Rietveld Technique

The analysis of x-ray diffraction (XRD) patterns by the Rietveld technique was tested to the quantitativelyphase compositions of self reinforcement AlzOiCaAl12019composite. Room-temperature XRD patterns revealed that a-Al203wasthe only phase presence in the CAOsample, whereas the a-A1203and CaAI12019phases were found for CA5,CA15, CA30, and CA50 samples. The peak intensity of CA6 in the self reinforcement Alz03/CaA112019compositesincreased in proportion with increase in CaAI12019content in contrast to a-AI203. The diffraction patterns for CA100sample shows minor traces of a-Ah03 even in relatively low peak intensity. It is suggesting that the in-situ reactionsintering of raw materials were not react completely to form 100 wt % CaAl12019at temperature 1650 DC.Quantitativephase compositions of self reinforcement AlzOiCaAl12019composites by Rietveld analysis with XRD data has beenwell demonstrated. The results showed that the OOF values are relatively low and the fluctuation in the difference plotsshows a reasonable fit between the observed and the calculated plot.Keywords: X-ray diffraction, Rietveld technique, Al20iCaAl12019PACS: 61.l0.Nz. D. Asmi, I.M. Low2, and B.O'Connor21Department of Physics, Faculty of Mathematics and Natural Sciences, University of Lampung,ll.Sumantri Brojonegoro No.1, Bandar Lampung 35145, Indonesia2Materials Research Group, Department of Applied Physics, Curtin University of Technology,GPO Box U 1987, Perth, Western Australia

Improvements in the Image Quality of Neutron Radiograms of NUR Neutron Radiography Facility by Using Several Exposure Techniques

Since the construction of NUR reactor neutron radiography facility in 1991, only transfer exposure methodwas used as a non destructive technique. The reason is the excess of gamma rays in the neutron beam. To improveradiation performances of the NR system, a stainless steal hollow conical cylinder is introduced at the bottom of thefacility beam port, this filter reduce gamma infiltration through the edges of the NR structure without disturbing neutronbeam arriving from the in pool divergent collimator. First results confmn our prediction; a gamma rays diminution and arelatively stable neutron flux at the point object are confmned, consequently the n/y ratio reaches a value of 2.104 n/cm2mR. Radiograms obtained by using the direct exposure method reveal the feasibility of the technique in the new NRconfiguration facility, but a weak resolution and contrast of the image is observed. In this paper, we describe a procedureto improve the image quality obtained by direct exposure technique. The process consists of using digitized imagesobtained by several exposure techniques (NR, gamma radiography or X radiography) for a comparison study and thenbetter image defmition can be attained.Keywords: neutron radiography, direct exposure technique, image quality, gamma raysPACS: 07.05.Rm, 81.70.-q. T. Zergoug~, A. Nedjarl, M.Y. Mokeddeml, L. MammoulCentre de Recherche Nucleaire de Draria, (CRND) BP 43 Draria 16000, Algiers, Algeria

Small Angle X-ray and Neutron Scattering in the Study of Polymers and Supramolecular Systems

X. B. Zengl, F. Liul, F. Xie\ G. Ungar\ C. Tschierske2, 1. E. Macdonald3I Department of Engineering Materials, Sheffield University, Sheffield Sl 3JD, United Kingdom2 Institute of Organic Chemistry, University Halle, Kurt-Mothes-Strasse 2, D-06120 Halle, Germany3 Department of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA, United Kingdom Some recent work carried out in our research group on complex structures found in polymers andsupramolecular systems, using Small Angle X-ray and Neutron Scattering (SAXS and SANS) methods, are reviewed.These include, Combined SAXS and SANS study of superlattice structures in pure and mixed model polymers; Real-timeSANS study of transient phases during polymer crystallization; Columnar phases with polygonal cross-sections inT-shaped polyphilic compounds;Complex 3-d phases formed by packing spherical objects (e.g. micelles self-assembledfrom tree-like molecules), including the recently discovered liquid quasi-crystals which possess 12-fold rotationalsymmetry. Examples of powder, fibre or surface oriented, and single-domain diffractions will be given. Reconstructionof electron density maps as well as computer modelling are also applied to help solving various complex structures.Keywords: SAXS, SANS, GI-SAXS, supramolecules, liquid crystal

Neutron Radiographic Inspection of Industrial Components using Kamini Neutron Source Facility

Kamini (Kalpakkam Mini) reactor is a U233 fuelled, dernineralised light water moderated and cooled,beryllium oxide reflected, low power (30 kW) nuclear research reactor. This reactor functions as a neutron source with aflux of 1012 n/cm2 S·I at core centre with facilitates for carrying out neutron radiography, neutron activation analysis andneutron shielding experiments. There are two beam tubes for neutron radiography. The length/diameter ratio of thecollimators is about 160 and the aperture size is 220 mm x 70 mm. Flux at the outer end of the beam tube is _ 106 - 107n/cm2 s. The north end beam tube is for radiography of inactive object while the south side beam tube is for radiographyof radioactive objects. The availability of high neutron flux coupled with good collimated beam provides high qualityradiographs with short exposure time. The reactor being a unique national facility for neutron radiography has beenutilized in the examination of irradiated components, aero engine turbine blades, riveted plates, automobile chain linksand for various types of pyro devices used in the space programme. In this paper, an overview of the salient features ofthis reactor facility for neutron radiography and our experience in the inspection of a variety of industrial componentswill be given.Keywords: Kamini, neutron radiography, flux, LID ratio, thermal neutron, pyro device, turbine blade, roller chainPACS: 29.25.Dz. N. Raghu, V. Anandaraj, K.V. Kasiviswanathan and P. KalyanasundaramIndira Gandhi Center for Atomic Research, Kalpakkam - 603102, India

The Use of Rietveld Technique to Study Phase Composition and Developments of Calcium Aluminate

The phase composition and development of calcium aluminates (CA, CA2, and CA6) processed by in-situreaction sintering of AI203 and CaC03 have been studied by Rietveld refinement technique. The formation of calciumaluminates is temperature-dependent. X-ray diffraction result revealed that the CA, CA2, and CA6 phases starts todevelop at approximately 1000 DC,1100 °c and 1375 DC,respectively. The relative phase compositions obtained from x-raydiffraction patterns for the a-A1203 phase decreased markedly with increasing temperature, Le. from 86.0(1.1) wt %at 1000 °c to 34.7(0.4) wt % at 1400 DC.The wt % of CA decreased from 10.9(0.3) - 1.9(0.2) wt % at 1100 - 1200 °cbut disappeared at 1300 DC.The wt % of CA2 reached 36.0(0.7) wt % at 1300 °c and decreased to 18.5 (0.5) wt % at1400°C. The wt % CA6 increased markedly from 1375 to 1400DC,i.e. 12.80(0.6)- 47.3(0.9) wt %. The goodness of fitvalues is relatively low and the fluctuation in the difference plots shows a reasonable fit between the observed and thecalculated plot.Keywords: X-ray diffraction, Rietveld technique, calcium aluminates (CA, CA2, and CA6).PACS: 61.10.Nz. I. Ridwan and D. Asmii Department of Physics, Faculty of Mathematics and Natural Sciences, University of Lampung, Il.Sumantri Brojonegoro No.1, Bandar Lampung 35145, Indonesia

Residual Stress Estimation of Ti Casting Alloy by X-ray Single Crystal Measurement Method

Recently, titanium casting teclmology attracts attention in tile industrial fields. These casting metals areincluding a various residual stresses due to the heat shrinkage and inclusion particles, et a!. In order to apply the castingteclmology, the accurate estimation of residual stresses is desired in many cases. In iliis study, it aims at thenondestructive stress evaluation of titanium casting material by the X-ray stress measurement teclmique. At first in thisstudy, the sin21Jf method which used in the usual X-ray stress measurement was tried to measure the residual stresses.However, it was unsuitable for measurement of titanium casting material because of including coarse grains. Therefore,another X-ray method for single crystal system was employed to coarse crystal grains, in order to investigate thepossibilities of residual stress estimating. Four-axes sample table which can set tile both of tilt angle and rotate one onthe sample surface was prepared. The stereographic diagrams and the theory of elasticity were used to measure tl1esingle crystal stresses on the sample surface.Keywords: Titanium (Ti), X-ray, residual stress measurement, casting alloyPACS: 6L10.-i. A. Shirol, M. Nishida2, T. ling3; IAdvanced Course of Mechanical System engineering, Kobe City College of Technology, Kobe 651-2194, Japan2Department of Mechanical engineering, Kobe City College of Technology, Kobe 651-2194, Japan, 3School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China

Rangkaian Logika

Rangkaian Logika yang disebut juga rangkaian Digital, merupakan rangkaian terpadu skala kecil (small scale integration) dari bahan semikonduktor, seperti halnya dioda-dioda, transistor dan lain-lain. Bahan semikonduktor ini sesuai dengan kegunaannya dan fungsinya dapat dipadukan menjadi rangkaian-rangkain gerbang logika (logical gating) yang selanjutnya dapat berfungsi sebagai NOT gate, AND/NAND gate, OR/NOR gate dan Exclusive OR/NOR gate. Rangkaian -rangkaian gerbang ini sesuai dengan kebutuhannya dan fungsingnya dapat dibentuk menjadi rangkaian terpadu skala menengah (medium scale integration) seperti : ADDER/SUBTRACTOR, FLIP-FLOP, ACCUMULLATORS (Registers), COUNTERS (Pencacah) dan sebagainya. Dari rangkaian terpadu skala menengah ini dapat dipadukan lagi pada skala yang lebih besar (very large scale integration) yang dapat membentuk antara lain yang disebut dengan MICROPROSSESSOR. Dengan sedikit mengerti tentang prinsip-prinsip dasar tentang Rangkaian Logika, maka selanjutnya diharapkan dapat memahami tentang kerjanya Komputer yang dapat mengolah data, menstransfer data, mencetak data dan menyimpan data secara elektronik.Teacher: Ir. Untung Sutoko. M.EngKata kunci : Digital, Gate, Flip-flop, Memories, Computer

New Control Strategies On PSS Optimization Improvement

The weighting Q and R in the optimization process and PSS parameters are important components of the multimachine power system. To improve the performance of power system, this paper presents new strategies of control. The strategy-1 tunes the optimal PSS paremeters using the generic algorithm (GA) calculation through LQ optimal control equation solution as an objective funciton. The strategy-2 develops strategy-1 through a modification of inverse-square method (ISM) ti design the weighting matrices. The strategy-3 uses the special GA to handle the duty of ISM by using the modification of a mutation process. In the last strategy, the initial chromosomes are created from ISM. Using these strategies, the application of multi-PSS and a conventional PSS are applied in the multimachine power system as comparison study. In the final, the strategy-3 has shown the best effort for power system behaviors improvements. It shows that convergences of GA has great improvement in theri penalty evaluation, in eigenvalues and settling time analyses. Keywords: power system dynamics and control, optimal control, inverse square method, genetic algorithm. Imam Robandi; Department of Electrical Engineering, FTI ITS, E-mail: robandi@ee.its.ac.id

Exploration and Development of Indigenous Knowledge of Ethnomedicine at Gede Pangrango Mountain

Plant diversity of Indonesian tropical fo-rest, including about 40,000 species of medicinal plants, is one of Indonesia’s invaluable natural resources. Besides, existence of almost 370 ethnic groups with their uniqueness in culture and tra-ditions enrich Indonesian cultures and etnome-dicine treasure. The process of deriving this in-digenous knowledge is orally prevails from one generation to the other. This circumstances will lead to the extinct of indigenous knowledge of et-nomedicine worsen by the introduction of modern culture. Therefore, the exploration of indigenous knowledge of etnomedicine is worth to be imple-mented followed by its development. Research activity to explore etnomedicine was conducted at Gede Pangrango mountain National Park areas, from January to December 2001. Survey has be-en done at 6 locations around Gede Pangrango, mountain within 2 districts (Sukabumi and Cian-jur). Surveyed locations and the respondent were decided deliberately regard to ease access. The results showed that utilization of folklore me-dicine around Gede Pangrango mountain Natio-nal Park areas was restricted to dukun ber-anak. Furthermore, at the buffer zones of Ge-de-Pangrango mountain National Park, 23 kinds of illness have been treated by using 72 tradi-tional prescriptions of 80 medicinal crops species. In general, the raw materials used for traditional medicine at the surveyed areas were MMI’s stan-dardized in quality. Therefore, that simplisia are prospected to be further developed for traditional medicine as well as modern drugs and cosmetic industries. Keywords : Gede Pangrango Mountain, survey, medicinal plants. Rosita SMD, Otih Rostiana, E. R. Pribadi dan Hernani; Balai Penelitian Tanaman Obat dan Aromatik. Keywords : Gede Pangrango Mountain, survey, medicinal plants

Semua dalam bentuk digital, dimana saya meletakkannya? Mengulas tentang teknologi penyimpanan data

Andry Yudianto; Mahasiswa SI Bid. Ilmu Perpustakaan UWKSTeknologi telah berkembang pesat dewasa ini. Perangkat keras, perangkat lunak dan konsep teknologi lainnya berkembang dengan pesat di mana hanya dalam waktu beberapa tahun telah dapat merubah bentuk dari bentuk cetak kemudian menjadi dalam bentuk digital. Hal ini secara tidak langsung juga merubah kebiasaan kita dalam mencari informasi yang sebelumnya kita biasa mendapatkannya dalam bentuk cetak, kemudian kita dapat mencari informasi secara cepat dan akurat dalam bentuk digital . Misalnya kita mencari informasi mengenai perkembangan teknologi dalam bidang kedokteran, dengan sekali klik kita sudah mendapatkan informasi yang kita cari dalam bentuk digital, tetapi apabila kita menginginkannya dalam bentuk cetak kita juga bisa langsung mencetaknya. Teknologi kali ini yang akan dibahas adalah media penyimpanan. Sebagian besar perpustakaan berusaha untuk mendigitalisasikan semua koleksinya dengan harapan bahwa adanya peningkatan dalam pelayanan Perpustakaan. Proses yang harus dilalui tidaklah mudah, sebagai langkah pertama harus merubah dari bentuk cetak menjadi bentuk digital dimana didalamnya terdapat proses yang sedikitnya memerlukan waktu. Setelah menjadi bentuk digital, kita memerlukan sebuah media penyimpanan untuk menyimpan koleksi bentuk digital tersebut, seperti halnya kita memerlukan rak buku untuk menyimpan buku tersebut, tetapi dalam hal ini bentuk digital memerlukan suatu media penyimpanan yang berbeda.

The control of flowering in time and space

The transition to flowering is one of the most important developmental decisions made by plants. Classical studies have highlighted the importance of photoperiod in controlling flowering time. More recently, the identification of mutants specifically affected in the photoperiod pathway in the model system Arabidopsis thaliana has enabled the flowering time pathways to be placed in a molecular context. This review highlights recent advances in understanding how photoperiod signals (perceived in the leaves) act at the apex of the plant where the floral stimulus is perceived. The photoperiod pathway acts predominantly through the gene CONSTANS to activate the small signalling molecule FT. While FT transcription is induced in the leaves, it is essential that FT protein is present at the apex of the plant. FT at the apex interacts with the transcription factor FD to induce flowering. Key words: Arabidopsis, FD, florigen, flowering, FTKatja E. Jaeger, Alexander Graf and Philip A. Wigge.E-mail: philip.wigge@bbsrc.ac.uk

Preparation of high tenacity polyester fibers and characterization of its physical and super molecular properties.

The research of preparation of high tenacity polyester and its characterization have been studied by supermolecular modification using heating, stretching and quenching. The partially oriented and crystallined polyester fibers were heating with various temperatures, stretching with various draw ratios, and quenching in order to make the difference crystallinity and orientations. From some testing, result it can be concluded that the combination of heating, stretching, quenching with the repeating processes at higher temperature will give the highest crystallinity and orientation. The higher the crystalling of polyester, tenacity and dimension stability tend to increase, however the elongation tend to decrease. Keywords: High tenacity polyester fiber, Supermolecular modification. Zubaidi; Balai Besar Penelitian dan Pengembangan Industri Tekstil-DEPERIN

Tinjauan “SPEKTROFOTOMETER”

PENDAHULUAN; Radiasi elektromagnetik dapat digunakan untuk menyelidiki sifat dari suatu zat serta mengetahui jumlah zat pada sampel . Interaksi radiasi elektromagnetik dengan atom atau molekul mengganggu elektron pada orbit dari atom atau molekul. Perhitungan secara kuantitatif dari perubahan radiasi elektromagnetik tersebut dengan menggunakan instrumentasi optik merupakan basis dari spektroskopi. Seperti lazimnya metoda atau teknik pengukuran, proses perhitungan akan melibatkan serentetan kejadian terpadu. Pertama zat yang akan diukur diidentifikasi ( berupa atom atau molekul ) kemudian dibuat interaksi antara radiasi elektromagnetik pada suatu panjang gelombang dengan jenis zat tersebut . Informasi dari zat kemudian ditransmisikan ke photodetektor yang bertindak sebagai transducer yang merubah besaran tersebut menjadi besaran listrik agar mudah diidentifikasi.Dengan kata lain secara kuantitatif enersi yang diserap oleh zat akan identik dengan jumlah zat perkandungan zat tersebut, sedangkan secara kualitatif panjang gelombang dimana enersi dapat diserap akan menunjukan jenis zatnya. Berdasarkan serapan yang terjadi, spektrofotometer dapat dibagi menjadi : - Serapan atom ( Jenis: Spektrofotometer serapan atom/AAS ) - Serapan Molekul ( Jenis: Spektrofotometer UV-Vis ) Sedangkan menurut spektrum dimana alat bekerja, nama alatnya adalah : - X-ray (diffraction) spektrometer - Vaccum ultraviolet spektrometer - Ultraviolet-visible spektrofotometer (Spektrofotometer UV-Vis) - Infra red pektrofotometer (Spektrofotometer IR) Semua jenis spektrofotometer merupakan alat ukur “Optoelektronik” yang fungsi kerjanya merupakan gabungan dari dua bidang ilmu yaitu Optik dan elektronik. Pada dasarnya spektrofotometer tersusun dari beberapa bagian yaitu :
- Sumber cahaya
- Monokromator
- Tempat sampel
- Detektor/ Sensor cahaya
- Sistem pembacaan/komponen elektronik pemroses data
Cahyanto

Hydrodynamic of pollutant dispersion in river

Hydrodynamics of pollutant dispersion in river have very connected to the result of river water quality monitoring. Thar it require to be done because till to date river water quality monitoring still be done by parsial that is by connecting results data of analysis of river water quality concentration with the long distance of river in the certain time observation and without including hydrodynamics element which can influence the dispersion of pollutant in river. And to drawing result of river water quality monitoring (not persial) needed mathematics model which in one of its methods is finite difference. As for one of finite difference method used in monitoring or river water quality observation that is two horizontal dimension ekplisit-Leap Frog finite difference method because this method will be able to give the illustration of dispersion of polutant in river (2 horizontal dimension) which hydrodynamics element have been included in it. Keywords: hydrodynamics, dispersion, pollutant. Niekr Karnaningroem, Nadjadji Anwar, Basuki Widodo, Wahyono Hadi, Ediyatno, Sri Wulandari, Farhan Nizam'iar, dan Aditya Maharani.E-mail: nieke@enviro.its.id.ac

The physical treatment soil characteristics for grounding systems on Madiun and Surabaya Region

The research on soil characteristic by measuring soil resistancy and resistivity is an important factor to make a good grounding impedance. The optimal evaluation and planning of the grounding system can be achived by understanding the soil structure and characteristic. The soil resistivity varies upon soil composition, temperature, water content and its chemical content. In this research we analyse soil characteristics of the samples from Madiun and Surabaya areas by conducting some physical treatments such as water, salt, and carbon treatments. These samples then area tested using OHz-15MHz frequency from sinusoidal power supply. Generally, soil impedance has a negative correlation upon addition of water and salt content, but has no correlation upon additional carbon content. Keywords: soil resitance, soil resistivity, grounding resistance, grounding system. Bambang Anggoro, Ngapuli I. Sinisuka, Parouli M. Pakpahan, dan Dicky Irman B. E-mail: bambang@hv.ee.itb.ac.id

ZAT RADIO AKTIF DAN PENGGUNAAN RADIO ISOTOP BAGI KESEHATAN

Jika kita membaca berita-berita di media massa, kita dapat mengatakanbetapa sering orang membicarakan nuklir. Namun sayang, kebanyakan beritanuklir tersebut berkaitan dengan senjata nuklir atau pencemaran radioaktif akibatkebocoran instalasi suatu reaktor atom, sementara yang menyangkut manfaatlain dari energi nuklir sangat jarang ditampilkan. Oleh karena itu, di lingkunganmasyarakat awam ikatan nuklir mempunyai konotasi yang mengerikan.Pemahaman yang kurang tepat itu bila terbelakangi oleh tragedi yang menimpaHirosima dan Nagasaki di Jepang, tempat pertama kalinya energi nuklirdiperkenalkan sebagai bom atom, suatu senjata pemusnah massal yangmengerikan. ABDUL JALIL AMRI ARMA; Bagian Kependudukan dan Biostatistik, Fakultas Kesehatan Masyarakat, Universitas Sumatera Utara

Integrated fuzzy AHP and weighted-fuzzy goal programming approach to solve supplier selection problem with subjective factors

Fuzzy goal programming (FGP) method used in supplier selection process shows that decision maker preferences on each fuzzy goal are not yer considered. In order to accommodate those preferences, that are stated as weight on each fuzzy goal, and called weighted fuzzy goal programming (WFGP) method. Then , the developed method is utilized to solve international supplier selection problem. There would be 4 objective functions developed i.e. to minimize net cost, to minimize late delivery, to minimize net rejected material, as well as to maximize business relationship. Maximization of business relationship objective function is intended to obtain right supplier related to it score. Those objective functions are optimized subjective to total demand, maximum supplier capacity, total purchasing cost based on owner estimate, and minimum order requested by suppliers. Linguistic variables are used to measure criterions in business relationship factor. To do so, fuzzy analytic hierarchy process (FAHP) transforms that qualitative manner in linguistic variables to numerical number as a constant in business relationship objective function. Those proposed method provides enhanced solution that represent decision maker preferences than FGP. That is exhibited with equal relationship between weighted goals value and the output of tjose weighted goals. Keywords: fuzzy goal programming, weghted, fuzzy analytic hierarchy process, supplier selection. Annas Singgih Setiyoko, Udisubakti Ciptomulyono dan I Ketut Gunarta. E-mail: asinggihs@yahoo.com

Effect of stirring and temperature on the separation of phytosterols using zeolite

The sterols mixture containing almost the same percentage of compesterol over B-sitosterol and that increasing stirring spedd tends to increase the amount of adsorbed sterols. Temperature has negligible effect on the adsorption selectivity of campesterol and B-sitosterol. Thermodynamic parameters of the adsorption further confirmed the endothermic nature of the adsorption process as shown by the positive heat of enthalpy, accompanied by a positive value of entropy change. The overall Gibbs free energy change during the adsorption process was negative for the experimental range of temperatures, corresponding to spontaneous adsorption. Keywords: adsorption, campesterol, B-sitosterol, zeolite, thermodynamic properties. Arief Widjaja and Yu-Hsuan Chung

Research And Development Of Superionic Conductor For Industrial Application

The recent work about structural and dynamical properties of super ionic conductors by the X-ray diffraction, neutron diffraction and inelastic neutron scattering measurements was reviewed. The expression of the diffuse scattering intensity based on the corelations among the thermal displacements of atoms has been given and applied to AgBr and CuI. The presence of low-energy excitations in crystalline anion conductor CsPbCI3 was investigated by neutron inelastic scattering measurements. The application of superionic conductors to industrial use was introduced. T. Sakuma; Batan

PERANCANGAN DAN IMPLEMENTASI ALAT UKUR CAHAYA SEDERHANA

Alat ukur cahaya (lux meter) adalah alat yang digunakan untuk mengukur besarnya intensitas cahaya di suatu tempat. Besarnya intensitas cahaya ini perlu untuk diketahui karena pada dasarnya manusia juga memerlukan penerangan yang cukup.Untuk mengetahui besarnya intensitas cahaya ini maka diperlukan sebuah sensor yang cukup peka dan linier terhadap cahaya. Sehingga cahaya yang diterima oleh sensor dapat diukur dan ditampilkan pada sebuah tampilan digital. Pada makalah ini dibahas mengenai perancangan dan implementasi sebuah alat ukur cahaya yang dapat mengukur dengan range 200 – 2000 lux.. Harga dari besarnya cahaya dapat ditampilkan pada layar LCD (Liquid Crystal Display) dengan menggunakan sebuah ADC (Analog to Digital Converter) Max ICL7106 dengan tegangan masukan antara 200 mV – 2 V dan tegangan referensi antara 100 mV – 1 V. Sensor cahaya yang digunakan adalah solar cell dengan tegangan keluaran sebesar 0.5 V dan arus 20 mA sampai 30 mA. Alat ukur ini dibuat portable dengan menggunakan tegangan sumber 9 V DC dari baterai. Perencanaan dan pembuatan dari alat ukur ini cukup sederhana hanya meliputi sensor cahaya, rangkaian pengubah arus ke tegangan, rangkaian ADC dan rangkaian LCD. Dari data pengukuran alat dengan pembanding (Digital Light Meter RS ISO-TECH ILM 350) didapat bahwa alat ini dapat bekerja dengan cukup baik pada media pengukuran dengan jarak antara sensor cahaya dan sumber cahaya antara 60 cm – 70 cm dengan persentase ketidakpresisian antara 0.411% - 0.677%. Gunadhi, Albert

An Investigation Into.........

The Application Of Maintenance Management Concept Based On Reliability Centered Maintenance Of TNI-AL Fleet (Case Study Of Corvette/Parchim Class). The majority of TNI-AL war-ships, particularly of parchim class, are old and have been used for more than twenty years. It can be said, intuitively, that rate of degradation of diesel engine system lies in the wear-out period of a bathtub curve. The present paper is aimed to obtain and prove degradation pattern rate and level of risk from diesel engine system installed in KRI fleet of parchim class. Function of degradation rate of each diesel engine system is obtained from the most suitable distibution represent failure mode. Hhilst, level of risk is determine with risk matrix. Weibull++ 4, a reliability software, was used to obtain parameters fit to each distribution. Keywords: bathtub curve, degradation rate, level of risk, failure mode, diesel engine system. Yanif D.K.m dan Iman T.D.