1,092 research outputs found
Biaya Kualitas Sebagai Usaha Perbaikan Kualitas Proses Produksi Dalam Rangka Mengurangi Produk Cacat
Manajemen produksi sebagai salah satu elemen penting dalam system manajemen Perusahaan, dengan kualitas proses produksi sebagai aspek penting yang ada didalamnya, memberikan andil cukup besar dalam kompetisi Perusahaan pada era persaingan yang semakin ketat. Dengan perencanaan proses produksi yang baik, ternyata jumlah produk cacat yang terjadi tidak mengalami penurunan yang signifikan. Hal ini terlihat dari hasil pengukuran kualitas proses yang dilakukan dengan menggunakan bantuan peta kendali jenis p dengan tingkat penolakan produksi sebagai variabel penelitian. Biaya kualitas yang merupakan indikator tak langsung dari kualitas proses merupakan variable penelitian lainnya yang diteliti. Selanjutnya digunakan diagram pareto untuk menganalisa kelompok biaya yang dominan, aktivitas yang dominan dan pengendalian kualitas (QC) yang menghasilkan biaya dominan. Berdasarkan hasil analisa Pareto dan Peta Kendali, maka dapat diindentifikasi faktor-faktor yang mempengaruhi kualitas proses produksi serta berpotensi menghasilkan biaya kualitas yang dominant, dengan menggunakan Diagram Tulang Ikan. Mengacu pada hasil identifikasi tersebut kemudian direkomendasikan beberapa usulan perbaikan sebagai bahan pertimbangan untuk meningkatkan kualitas proses produksinya. Katakunci: kualitas proses produksi, peta kendali, biaya kualitas, diagram pareto, diagram tulang ika
NEURAL NETWORKING OF INFILLED RC LOW-RISE SERVICE BUILDINGS
Artificial neural networks (ANNs) are one of the most research areas that attracts the attention of experts of various scientific areas. Recent research activities regarding ANNs indicated that this method is a powerful tool to solve complicated problems in engineering fields.In this paper, ANNs were utilized to predict the lateral behavior of school buildings in Egypt. For this, reinforced concrete (RC) frames representing common school buildings with different characteristics were analyzed using nonlinear dynamic pushover analysis to obtain their capacity curves, failure loads and displacements. Parameters included number of stories, location and dimensions of the frames, distribution of masonry infill panels, and properties of concrete and reinforcement. Obtained data were used to train several ANN models with different topologies and learning algorithms. The most representative ANN was used to obtain more insight into the behavior of school building frames with different parameters
Efficacy of extractives from parts of Ghanaian pawpaw, avocado and neem on the durability of alstonia
Conventional preservatives are not only toxic to wood bio-deteriorators, but also to humans and animals. In an effort to find preservatives that are non-toxic to humans and animals, efficacy of water extracts of heartwood of Azadirachta indica (Neem) and leaves of Persea americana (avocado) and Carica papaya (pawpaw) at 0.24%, was tested on the durability of wood of Alstonia boonei by pressure impregnation and buried in a termite-prone field for 5 weeks following a modified EN 252 and Gay et al. (1957). Efficacy was tested on the basis of visual durability ratings, percentage hardness and mass losses of impregnated alstonia wood after burial. Though alstonia wood retained pawpaw extract least, pawpaw extract improved the durability of alstonia wood most. Pawpaw extract could be used to improve the durability of alstonia wood better at 0.72% (3x0.24%) and on triple treatment. 83% of Anloga furniture makers who saw the efficacy of pawpaw extract at 0.72% and on triple treatment, showed a high sense of interest in preservative botanical extracts.Key words: Eco-friendly, termite, efficacy, standardization, percentage hardness loss, percentage mass loss, visual durability rating
A Density Functional Study of Atomic Hydrogen and Oxygen Chemisorption on the Relaxed (0001) Surface of Double Hexagonal Close Packed Americium
Ab initio total energy calculations within the framework of density
functional theory have been performed for atomic hydrogen and oxygen
chemisorption on the (0001) surface of double hexagonal packed americium using
a full-potential all-electron linearized augmented plane wave plus local
orbitals method. Chemisorption energies were optimized with respect to the
distance of the adatom from the relaxed surface for three adsorption sites,
namely top, bridge, and hollow hcp sites, the adlayer structure corresponding
to coverage of a 0.25 monolayer in all cases. Chemisorption energies were
computed at the scalar-relativistic level (no spin-orbit coupling NSOC) and at
the fully relativistic level (with spin-orbit coupling SOC). The two-fold
bridge adsorption site was found to be the most stable site for O at both the
NSOC and SOC theoretical levels with chemisorption energies of 8.204 eV and
8.368 eV respectively, while the three-fold hollow hcp adsorption site was
found to be the most stable site for H with chemisorption energies of 3.136 eV
at the NSOC level and 3.217 eV at the SOC level. The respective distances of
the H and O adatoms from the surface were found to be 1.196 Ang. and 1.164 Ang.
Overall our calculations indicate that chemisorption energies in cases with SOC
are slightly more stable than the cases with NSOC in the 0.049-0.238 eV range.
The work functions and net magnetic moments respectively increased and
decreased in all cases compared with the corresponding quantities of bare dhcp
Am (0001) surface. The partial charges inside the muffin-tins, difference
charge density distributions, and the local density of states have been used to
analyze the Am-adatom bond interactions in detail. The implications of
chemisorption on Am 5f electron localization-delocalization are also discussed.Comment: 9 Tables, 5 figure
Influence of gas flow rate on liquid distribution in trickle-beds using perforated plates as liquid distributors
Two wire mesh tomography devices and a liquid collector were used to study
the influence of the gas flow rate on liquid distribution when fluids
distribution on top of the reactor is ensured by a perforated plate. In
opposition to most of the studies realized by other authors, conditions in
which the gas has a negative impact in liquid distribution were evidenced.
Indeed, the obtained results show that the influence of gas flow rate depends
on the quality of the initial distribution, as the gas forces the liquid to
"respect" the distribution imposed at the top of the reactor. Finally, a
comparison between the two measuring techniques shows the limitations of the
liquid collector and the improper conclusions to which its use could lead
A Comparison Of The Performances Of Various Single Variable Charts.
Control charts are used for process monitoring and improvement in industries. Two charts are usually used in the monitoring of both the mean and variance separately
Synthesis, structural and morphological characterizations of nano-Ru-based perovskites/RGO composites
Highly-dispersed Ru-based perovskites supported on reduced graphene oxide (A-RG) nanocomposites are prepared using different A-metal salts (Sr(NO₃)₂, Ba(NO₃)₂ and Ca(NO₃)₂). The procedure is based on a redox reaction between the metal precursors and graphene oxide (GO) using two different routes of reaction initiation: through thermal heating or by microwave-assisted heating. The resulting nanocomposites do not require further calcination, making this method less energy-demanding. In addition, no additional chemical reagents are required for either the GO reduction or the metal precursor oxidation, leading to an overall simple and direct synthesis method. The structure and morphology of the as-prepared A-RG (non-calcined) nanocomposites are characterized using various structural analyses including XRD, XPS, SEM/EDX and HR-TEM. Changing metal A in the perovskite as well as the “activation method” resulted in significant structural and morphological changes of the formed composites. SrRuO₃ and BaRuO₃ in combination with RuO₂ are obtained using a conventional combustion method, while SrRuO₃ (~1 nm size) in combination with Ru nanoparticles are successfully prepared using microwave irradiation. For the first time, a microwave-assisted synthesis method (without calcination) was used to form crystalline nano-CaRuO₃
Information-Driven Inverse Approach to Disordered Solids: Applications to Amorphous Silicon
© Physical Review Materials
Publisher\u27s Versio
density-functional studies of 13-atom Cu and Ag clusters
The putative ground-state structures of 13-atom Cu and Ag clusters have been
studied using molecular-dynamics (AIMD) simulations based
on the density-functional theory (DFT). An ensemble of low-energy
configurations, collected along the AIMD trajectory and optimized to nearest
local minimum-energy configurations, were studied. An analysis of the results
indicates the existence of low-symmetric bilayer structures as strong
candidates for the putative ground-state structure of Cu and Ag
clusters. These bilayer structures are markedly different from a buckled
bi-planar (BBP) configuration and energetically favorable, by about 0.40.5
eV, than the latter proposed earlier by others. Our study reveals that the
structure of the resulting putative global-minimum configuration is essentially
independent of the nature of basis functions (i.e., plane waves versus
pseudoatomic orbitals) employed in the calculations, for a given
exchange-correlation functional. The structural configurations obtained from
plane-wave-based DFT calculations show a slightly tighter or dense first-shell
of Cu and Ag atoms than those from local-basis functions. A comparison of our
results with recent full-potential DFT simulations is presented.Comment: 5 pages, 5 figure
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