Analisis Perbandingan Concentrated Winding Dan Toroidal Winding Pada Generator Axial Flux Permanent Magnet (AFPM) Tiga Fasa Menggunakan Inti Besi Pada Stator

Kebutuhan energi listrik terus meningkat seiring dengan pertumbuhan industri dan masyarakat dunia. Energi terbarukan menjadi salah satu alternatif untuk menanggulangi peningkatan penggunaan energi listrik tersebut. Belakangan ini perkembangan generator dalam memproduksi energi listrik sudah sangat beragam salah satunya menggunakan generator Axial Flux Permanent Magnet (AFPM) yang biasanya dirancang untuk memanfaatkan energi terbarukan dengan kecepatan rendah seperti air dan angin. Generator AFPM pada umumnya menggunakan stator tanpa inti dengan konfigurasi belitan concentrated. Pada pembahasan skripsi ini dibandingkan dua buah stator dengan  menggunakan inti besi yaitu konfigurasi Concentrated Winding dan konfigurasi Toroidal Winding. Generator yang digunakan memiliki spesifikasi rotor dan stator yang sama. Generator yang dirancang dengan tegangan 110 volt frekuensi 50 Hz, dan daya perhitungan sekitar 100 watt. Dari hasil pengujian generator AFPM tiga phasa dengan menjaga konstan frekuensi sebesar 50 Hz pada konfigurasi Concentrated Winding dihasilkan tegangan pengujian tanpa beban sekitar 106,5 volt, tegangan pengujian berbeban sekitar 45,6 volt, dan daya 87,15 watt dengan efisiensi generator 72,61 %. Sementara pada konfigurasi Toroidal Winding dihasilkan tegangan pengujian tanpa beban sekitar 110,6 volt, tegangan pengujian saat berbeban sekitar 42,4 volt, dan daya 77,16 watt dengan efisiensi generator 70,51 %. Berdasarkan hasil tersebut disimpulkan bahwa konfigurasi Concentrated Winding lebih baik daripada konfigurasi Toroidal Winding

Development of a framework for disassemblability design optimization for sustainable manufacturing

Sustainable Product development is seen as an inevitable solution in protecting the environment. Among the important strategy in sustainable product development is through product recovery by closing the loop. Product recovery enables the reuse of depleting source of virgin material as well as avoiding the accumulation of solid waste. Maintenance can be also considered as a strategy towards sustainable product by prolonging product life time. The success of product recovery and maintenance is highly dependant on the time and cost efficiencies of the disassembly process. This paper reviews the various methods used to evaluate disassemblability. The development of the methods and its application are reviewed to provide an understanding of any missing links that have hampered the wider implementation of disassemblability design evaluations. The paper then proposes a disassemblability optimization model that can provide the missing link between design and disassembl

MACHINING MODEL OF TI-6AL-4V TITANIUM ALLOY USINGFEM SIMULATION

This paperpresents a machining modelof Ti-6Al-4V titanium alloy using finite element method (FEM) simulation. The constitutive Johnson–Cook material flow stress was employed to predict material plasticity, chip morphology, cutting forces and stress distribution. Comparative analysis for both simulation and experimental data were carried out. The simulated results show that workpiece material flow around the cutting edge of the tool and deposited themselves to form a continuous curl chip formation. The stress distribution generated in the shearing plane during steady state conditions and the residual stress is formed beneath the machined surface.The cuttingforces were essentially constant across the range of cutting speeds. This agreedwith the trend from the experimental trials

Thermal insitu analyses of multicomponent pyrophosphate cathodes materials

Development of secondary batteries based on abundant and inexpensive elements are vital. Amongvarious alternative choices, sodium-ion batteries (NIBs) are promising because of plentiful resourcesand low costs of sodium metal. Different types of cathode materials for NIBs have been designed andstudied to meet the challenging requirements. Among them pyrophosphate cathodes have shownpromising electrochemical performance and thermal stability in sodium ion batteries (SIBs). In thepresent study, we report synthesis and thermal behavior of a novel Na2Fe0.33Mn0.33Co0.33P2O7 cathodematerial developed for sodium rechargeable batteries. The material was developed through solid stateprocess. The structural analysis of Na2Fe0.33Mn0.33Co0.33P2O7 revealed that the substitution ofmulticomponent transition metals have achieved triclinic crystal structure (P1 space group). TGA/DTAand thermal in-situ XRD analyses (25~550oC) confirm decent thermal stability of this material up to550oC even in the desodiated state with negligible weight loss (5%). Owing to its promising thermalstability, Na2Fe0.33Mn0.33Co0.33P2O7, would be an attractive cathode for sodium ion batteries.Scopu

Investigation of Effects of Carbon Nanofiber Nanofluid in Drilling of AISI 304 Stainless Steel

This paper presents the experimental study of the effects of carbon nanofiber (CNF) nanofluid in drilling of AISI 304 stainless steel. The drilling performance was assessed based on the surface roughness inside the holes, hole dimensional accuracy and burr formation using four different CNF nanofluid concentrations. The machining performance of CNF nanofluid also compared with the base fluid (deionized water) only. The experimental results show that the CNF nanofluid not only improve the surface finish and hole accuracy, but also reduce the burr formation at the circumference of the drilled hole

Muon production in extensive air showers and its relation to hadronic interactions

In this work, the relation between muon production in extensive air showers and features of hadronic multiparticle production at low energies is studied. Using CORSIKA, we determine typical energies and phase space regions of secondary particles which are important for muon production in extensive air showers and confront the results with existing fixed target measurements. Furthermore possibilities to measure relevant quantities of hadron production in existing and planned accelerator experiments are discussed.Comment: To appear in the proceedings of international conference on interconnection between high energy physics and astroparticle physics "From Colliders to Cosmic Rays" (C2CR 2005), Prague, Czech Republic, 7-13 September 200

Measurement of the W+W-gamma Cross Section and Direct Limits on Anomalous Quartic Gauge Boson Couplings at LEP

The process e+e- -> W+W-gamma is analysed using the data collected with the L3 detector at LEP at a centre-of-mass energy of 188.6GeV, corresponding to an integrated luminosity of 176.8pb^-1. Based on a sample of 42 selected W+W- candidates containing an isolated hard photon, the W+W-gamma cross section, defined within phase-space cuts, is measured to be: sigma_WWgamma = 290 +/- 80 +/- 16 fb, consistent with the Standard Model expectation. Including the process e+e- -> nu nu gamma gamma, limits are derived on anomalous contributions to the Standard Model quartic vertices W+W- gamma gamma and W+W-Z gamma at 95% CL: -0.043 GeV^-2 < a_0/Lambda^2 < 0.043 GeV^-2 0.08 GeV^-2 < a_c/Lambda^2 < 0.13 GeV^-2 0.41 GeV^-2 < a_n/Lambda^2 < 0.37 GeV^-2

Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV

We report the results of a study of color coherence effects in ppbar collisions based on data collected by the D0 detector during the 1994-1995 run of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8 TeV. Initial-to-final state color interference effects are studied by examining particle distribution patterns in events with a W boson and at least one jet. The data are compared to Monte Carlo simulations with different color coherence implementations and to an analytic modified-leading-logarithm perturbative calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters

Production of Single W Bosons at \sqrt{s}=189 GeV and Measurement of WWgamma Gauge Couplings

Single W boson production in electron-positron collisions is studied with the L3 detector at LEP. The data sample collected at a centre-of-mass energy of \sqrt{s} = 188.7GeV corresponds to an integrated luminosity of 176.4pb^-1. Events with a single energetic lepton or two acoplanar hadronic jets are selected. Within phase-space cuts, the total cross-section is measured to be 0.53 +/- 0.12 +/- 0.03 pb, consistent with the Standard Model expectation. Including our single W boson results obtained at lower \sqrt{s}, the WWgamma gauge couplings kappa_gamma and lambda_gamma are determined to be kappa_gamma = 0.93 +/- 0.16 +/- 0.09 and lambda_gamma = -0.31 +0.68 -0.19 +/- 0.13

Search for an invisibly decaying Higgs boson in e^+e^- collisions at \sqrt{s} = 183 - 189 GeV

A search for a Higgs boson decaying into invisible particles is performed using the data collected at LEP by the L3 experiment at centre-of-mass energies of 183 GeV and 189 GeV. The integrated luminosities are respectively 55.3 pb^-1 and 176.4 pb^-1. The observed candidates are consistent with the expectations from Standard Model processes. In the hypothesis that the production cross section of this Higgs boson equals the Standard Model one and the branching ratio into invisible particles is 100%, a lower mass limit of 89.2 GeV is set at 95% confidence level