4,792 research outputs found
Identifikasi Kompetensi SMK Program Studi Otomotif dalam Rangka Implementasi Kebijakan Kurikulum 2013
The objective of this study was to determine; 1) the relevance of competencies in curriculum 2013 with the expectation of the school and the world of business and industry 2) the competencies expected by the school and the world of business and industry for the development of curriculum 2013, and 3) the roles of lecturers and education experts in the implementation of curriculum 2013, especially for the Department of Automotive, Vocational High Schools in Yogyakarta. The study was conducted with survey approach in the industry (authorized workshops), schools (Vocational High School), and universities (YSU and STU). The data collection was conducted using documentation, questionnaires, and interviews. The data was analysed using quantitative descriptive statistics. The results showed that: the relevance of competencies in curriculum 2013 with the expected competencies was 82% to 89%. The competencies expected by the schools and the world of business and industry consists of drawing with autocad and / or 3D max, spooring, as well as maintaining hidroulik power steering, measuring and analyzing vehicle emissions, maintaining hydraulic power steering (HPS), analyzing damage in the system of wiring diagram, and conducting damage diagnosis. The lectures' contribution in the socialization and implementation aspects were categorized as good with the mean scores of 73 and 39.5 respectively
Combination Rules, Charge Symmetry, and Hall Effect in Cuprates
The rule relating the observed Hall coefficient to the spin and charge
responses of the uniform doped Mott insulator is derived. It is essential to
include the contribution of holon and spinon three-current correlations to the
effective action of the gauge field. In the vicinity of the Mott insulating
point the Hall coefficient is holon dominated and weakly temperature dependent.
In the vicinity of a point of charge conjugation symmetry the holon
contribution to the observed Hall coefficient is small: the Hall coefficient
follows the temperature dependence of the diamagnetic susceptibility with a
sign determined by the Fermi surface shape. NOTE: document prepared using
REVTEX. (3 Figs, not included, available on request from: [email protected])Comment: 8 page
40Ar/39Ar geochronology of Holocene basalts; examples from Stromboli, Italy
Absolute chronologies of active volcanoes and consequently timescales for eruptive behaviour and magma production form a quantitative basis for understanding the risk of volcanoes. Surprisingly, the youngest records in the geological timescale often prove to be the most elusive when it comes to isotopic dating. Absolute Holocene volcanic records almost exclusively rely on
14C ages measured on fossil wood or other forms of biogenic carbon. However, on volcanic flanks, fossil carbon is often not preserved, and of uncertain origin when present in paleosols. Also, low 14C-volcanic CO2 may have mixed with atmospheric and soil 14C-CO2, potentially causing biased ages. Even when reliable data are available, it is important to have independent corroboration of inferred chronologies as can be obtained in principle using the 40K/40Ar decay system. Here we present results of a 40Ar/39Ar dating study of basaltic groundmass in the products from the Pleistocene – Holocene boundary until the beginning of the historic era for the north-northeastern flank of Stromboli, Aeolian Islands, Italy, identifying a short phase of intensified flank effusive activity 7500±500 yrs ago, and a maximum age of 4000±900 yr for the last flank collapse event that might have caused the formation of the Sciara del Fuoco depression. We expect that under optimum conditions 40Ar/39Ar dating of basaltic groundmass samples can be used more widely for dating Holocene volcanic events
Frustration induced Raman scattering in CuGeO_3
We present experimental data for the Raman intensity in the spin-Peierls
compound CuGeO_3 and theoretical calculations from a one-dimensional frustrated
spin model. The theory is based on (a) exact diagonalization and (b) a recently
developed solitonic mean field theory. We find good agreement between the
1D-theory in the homogeneous phase and evidence for a novel dimerization of the
Raman operator in the spin-Peierls state. Finally we present evidence for a
coupling between the interchain exchange, the spin-Peierls order parameter and
the magnetic excitations along the chains.Comment: Phys. Rev. B, Rapid Comm, in Pres
Studies of Vibrational Properties in Ga Stabilized d-Pu by Extended X-ray Absorption Fine Structure
Temperature dependent extended x-ray absorption fine structure (EXAFS)
spectra were measured for a 3.3 at% Ga stabilized Pu alloy over the range T= 20
- 300 K at both the Ga K-edge and the Pu L_III-edge. The temperature dependence
of the pair-distance distribution widths, \sigma(T) was accurately modeled
using a correlated-Debye model for the lattice vibrational properties,
suggesting Debye-like behavior in this material. We obtain pair- specific
correlated-Debye temperatures, \Theta_cD, of 110.7 +/- 1.7 K and 202.6 +/- 3.7
K, for the Pu-Pu and Ga-Pu pairs, respectively. These results represent the
first unambiguous determination of Ga-specific vibrational properties in PuGa
alloys, and indicate the Ga-Pu bonds are significantly stronger than the Pu-Pu
bonds. This effect has important implications for lattice stabilization
mechanisms in these alloys.Comment: 7 pages, 4 figures, Phys. Rev. B in pres
Study of the magnetic susceptibility in the spin-Peierls system CuGeO
We study numerically, using a one-dimensional Heisenberg model, the
spin-Peierls transition in the linear Cu spin-1/2 chains in the
inorganic compound CuGeO which has been recently observed experimentally.
We suggest that the magnetic susceptibility, the temperature dependence of the
spin gap and the spin-Peierls transition temperature of this material can be
reasonably described by including nearest and next nearest neighbor
antiferromagnetic interactions along the chain. We estimate that the nearest
neighbor exchange parameter J is approximately , and that the next
nearest neighbor exchange parameter is approximately .Comment: 14 pages, Revtex v2.0, 4 figures available upon reques
Lattice dynamics and correlated atomic motion from the atomic pair distribution function
The mean-square relative displacements (MSRD) of atomic pair motions in
crystals are studied as a function of pair distance and temperature using the
atomic pair distribution function (PDF). The effects of the lattice vibrations
on the PDF peak widths are modelled using both a multi-parameter Born
von-Karman (BvK) force model and a single-parameter Debye model. These results
are compared to experimentally determined PDFs. We find that the near-neighbor
atomic motions are strongly correlated, and that the extent of this correlation
depends both on the interatomic interactions and crystal structure. These
results suggest that proper account of the lattice vibrational effects on the
PDF peak width is important in extracting information on static disorder in a
disordered system such as an alloy. Good agreement is obtained between the BvK
model calculations of PDF peak widths and the experimentally determined peak
widths. The Debye model successfully explains the average, though not detailed,
natures of the MSRD of atomic pair motion with just one parameter. Also the
temperature dependence of the Debye model largely agrees with the BvK model
predictions. Therefore, the Debye model provides a simple description of the
effects of lattice vibrations on the PDF peak widths.Comment: 9 pages, 11 figure
Strong-coupling expansions for the anharmonic Holstein model and for the Holstein-Hubbard model
A strong-coupling expansion is applied to the anharmonic Holstein model and
to the Holstein-Hubbard model through fourth order in the hopping matrix
element. Mean-field theory is then employed to determine transition
temperatures of the effective (pseudospin) Hamiltonian. We find that anharmonic
effects are not easily mimicked by an on-site Coulomb repulsion, and that
anharmonicity strongly favors superconductivity relative to charge-density-wave
order. Surprisingly, the phase diagram is strongly modified by relatively small
values of the anharmonicity.Comment: 34 pages, typeset in ReVTeX, 11 encapsulated postscript files
include
Operational experience with the GEM detector assembly lines for the CMS forward muon upgrade
The CMS Collaboration has been developing large-area triple-gas electron multiplier (GEM) detectors to be installed in the muon Endcap regions of the CMS experiment in 2019 to maintain forward muon trigger and tracking performance at the High-Luminosity upgrade of the Large Hadron Collider (LHC); 10 preproduction detectors were built at CERN to commission the first assembly line and the quality controls (QCs). These were installed in the CMS detector in early 2017 and participated in the 2017 LHC run. The collaboration has prepared several additional assembly and QC lines for distributed mass production of 160 GEM detectors at various sites worldwide. In 2017, these additional production sites have optimized construction techniques and QC procedures and validated them against common specifications by constructing additional preproduction detectors. Using the specific experience from one production site as an example, we discuss how the QCs make use of independent hardware and trained personnel to ensure fast and reliable production. Preliminary results on the construction status of CMS GEM detectors are presented with details of the assembly sites involvement
A novel application of Fiber Bragg Grating (FBG) sensors in MPGD
We present a novel application of Fiber Bragg Grating (FBG) sensors in the
construction and characterisation of Micro Pattern Gaseous Detector (MPGD),
with particular attention to the realisation of the largest triple (Gas
electron Multiplier) GEM chambers so far operated, the GE1/1 chambers of the
CMS experiment at LHC. The GE1/1 CMS project consists of 144 GEM chambers of
about 0.5 m2 active area each, employing three GEM foils per chamber, to be
installed in the forward region of the CMS endcap during the long shutdown of
LHC in 2108-2019. The large active area of each GE1/1 chamber consists of GEM
foils that are mechanically stretched in order to secure their flatness and the
consequent uniform performance of the GE1/1 chamber across its whole active
surface. So far FBGs have been used in high energy physics mainly as high
precision positioning and re-positioning sensors and as low cost, easy to
mount, low space consuming temperature sensors. FBGs are also commonly used for
very precise strain measurements in material studies. In this work we present a
novel use of FBGs as flatness and mechanical tensioning sensors applied to the
wide GEM foils of the GE1/1 chambers. A network of FBG sensors have been used
to determine the optimal mechanical tension applied and to characterise the
mechanical tension that should be applied to the foils. We discuss the results
of the test done on a full-sized GE1/1 final prototype, the studies done to
fully characterise the GEM material, how this information was used to define a
standard assembly procedure and possible future developments.Comment: 4 pages, 4 figures, presented by Luigi Benussi at MPGD 2015 (Trieste,
Italy). arXiv admin note: text overlap with arXiv:1512.0848
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