3,525 research outputs found
Pemanfaatan Bottom Ash Sebagai Agregat Buatan
The aim of this study is to explore the possible use of bottom ash as artificial aggregates. It is found that the pelletizer method by using mixer without blade is one possibility to manufacture artificial aggregates. The optimum mixture composition of artificial aggregate is found to be 3 BA : 1FA : 0,5 C , by weight, and immersed once in cement slurry. The water content in ssd condition is 27% with the compressive strength of the aggregate 2.4 MPa on the seventh day. Concrete produced with mixture compositition of 1 cement : 1.5 sand by weight, resulted in water content of 14.63% in ssd condition and compresive strength of 14.20 MPa at 28th day
Pembuatan Pasta Ringan Geopolimer Celluler Lightweight Concrete (Clc) Berbasis Campuran Lumpur Sidoarjo Dan Fly Ash
Penelitian ini membahas upaya pemanfaatan lumpur Sidoarjo dan sisa pembakaran batubara berupa fly ash agar dapat bermanfaat untuk dunia konstruksi sebagai pengganti semen. Penelitian ini menggunakan bahan dasar lumpur Sidoarjo, fly ash, NaOH, sodium silikat, dan foam agent. Variasi kadar sodium silikat yang digunakan pada percobaan sebesar 30%, 40%, 50% dan 60% dari massa campuran lumpur dan fly ash,dengan memperhatikan perbandingan massa larutan sodium silikat dengan larutan NaOH. Variasi molaritas NaOH yang digunakan pada percobaan sebesar 5M, 6M, 7M dan 8M.Untuk menghasilkan berat jenis yang lebih kecil maka ditambahkan foam agent. Perbandingan volume foam agent dengan air yang digunakan adalah 1:50. Pada masing-masing penelitian tersebut diberikan variasi pemberian foam sebesar 0.5 liter, 1 liter, dan 1.5 liter yang dikonversi menjadi perbandingan massa foam dengan massa binder (campuran lumpur Sidoarjo, fly ash, NaOH padat, sodium silikat dan air). Pengujian yang dilakukan adalah tes kuat tekan pada benda uji berukuran 5×5×5 cm3, dan uji berat jenis.Hasil terbaik dari penelitian ini, yaitu campuran fly ash murni dengan komposisi larutan sodium silikat 480 gram (60%), NaOH 5M, dan penambahan foam 1.5 liter.Hasil kuat tekan umur 7 hari sebesar 1.44 MPa dan berat jenis sebesar 0.61 gr/cm3
Implementasi Peraturan Daerah Kota Pekanbaru No. 8 Tahun 2012 Tentang Retribusi Izin Gangguan ( Studi Kasus SPBU)
Pekanbaru city is one of the cities in Indonesia are experiencing a rapid increase in business development and investment in Indonesia. Disturbance Permit be one important factor in obtaining legality of local authorities towards the establishment of a business. Appropriation nuisance permit (HO) aims to protect the public interest and to maintain order and as a form of government oversight and pengedalian in certain locations which may cause hazards losses and disruption. Establishment of a gas station in the city of Pekanbaru often cause problems with the surrounding community. On the other hand there are many gas station stations that have not paid levies nuisance permit (HO). Integrated Service Agency and Investment (BPTPM) Pekanbaru City as an institution designated by the city of Pekanbaru who has authority in the permitting process and the levy charged for this permit in accordance with Regulation City of Pekanbaru No. 8 in 2012 regarding Disturbance Permit.Based on these findings, this study aims to determine the extent of implementation and the factors that affect the implementation of Pekanbaru City Regional Regulation No. 8 in 2012. This study uses the theory of implementation by Van Meter and Van Horn who has six variables, standards and objectives, resources, characteristics of the implementing agencies, communication between organizations, socio-economic conditions and political and disposition. The method used in this research is qualitative research. With the technique performed is purposive sampling to key informants. In this study, the informant is BPTPM, Disperindag Pekanbaru and related institutions. In gathering the data used qualitative approach with the method of observation and interviews, after the data is collected then analyzed by descriptive.Based on the research that has been carried out based on theoretical concepts, the implementation of Local Regulation No. 8 in 2012 Licenses Disorders at the Gas Stations, has been implemented by BPTPM. However, implementation of the regulations are not well realized. Weak sanctions make local regulation of fee collection process is not going well. The lack of resources in the form of personnel and technical team in the field also affects the implementation of the local regulation
Inhomogeneous Quasi-stationary States in a Mean-field Model with Repulsive Cosine Interactions
The system of N particles moving on a circle and interacting via a global
repulsive cosine interaction is well known to display spatially inhomogeneous
structures of extraordinary stability starting from certain low energy initial
conditions. The object of this paper is to show in a detailed manner how these
structures arise and to explain their stability. By a convenient canonical
transformation we rewrite the Hamiltonian in such a way that fast and slow
variables are singled out and the canonical coordinates of a collective mode
are naturally introduced. If, initially, enough energy is put in this mode, its
decay can be extremely slow. However, both analytical arguments and numerical
simulations suggest that these structures eventually decay to the spatially
uniform equilibrium state, although this can happen on impressively long time
scales. Finally, we heuristically introduce a one-particle time dependent
Hamiltonian that well reproduces most of the observed phenomenology.Comment: to be published in J. Phys.
Statistical model for intermittent plasma edge turbulence
The Probability Distribution Function of plasma density fluctuations at the
edge of fusion devices is known to be skewed and strongly non-Gaussian. The
causes of this peculiar behaviour are, up to now, largely unexplored. On the
other hand, understanding the origin and the properties of edge turbulence is a
key issue in magnetic fusion research. In this work we show that a stochastic
fragmentation model, already successfully applied to fluid turbulence, is able
to predict an asymmetric distribution that closely matches experimental data.
The asymmetry is found to be a direct consequence of intermittency. A
discussion of our results in terms of recently suggested BHP universal curve
[S.T. Bramwell, P.C.W. Holdsworth, J.-F. Pinton, Nature (London) 396, 552
(1998)], that should hold for strongly correlated and critical systems, is also
proposedComment: 13 pages. Physica Review E, accepte
The Spectator Electromagnetic Effect on Charged Pion Spectra in Peripheral Ultrarelativistic Heavy-Ion Collisions
We estimate the electromagnetic effect of the spectator charge on the
momentum spectra of and produced in peripheral Pb+Pb collisions
at SPS energies. We find that the effect is large and results in strongly
varying structures in the dependence of the ratio,
especially at low transverse momenta where a deep valley in the above ratio is
predicted at 0.15 -- 0.20.
It appears that the effect depends on initial conditions. Thus, it provides
new information on the space and time evolution of the non-perturbative pion
creation process.Comment: 20 pages and 8 figure
First and second order clustering transitions for a system with infinite-range attractive interaction
We consider a Hamiltonian system made of classical particles moving in
two dimensions, coupled via an {\it infinite-range interaction} gauged by a
parameter . This system shows a low energy phase with most of the particles
trapped in a unique cluster. At higher energy it exhibits a transition towards
a homogenous phase. For sufficiently strong coupling an intermediate phase
characterized by two clusters appears. Depending on the value of the
observed transitions can be either second or first order in the canonical
ensemble. In the latter case microcanonical results differ dramatically from
canonical ones. However, a canonical analysis, extended to metastable and
unstable states, is able to describe the microcanonical equilibrium phase. In
particular, a microcanonical negative specific heat regime is observed in the
proximity of the transition whenever it is canonically discontinuous. In this
regime, {\it microcanonically stable} states are shown to correspond to {\it
saddles} of the Helmholtz free energy, located inside the spinodal region.Comment: 4 pages, Latex - 3 EPS Figs - Submitted to Phys. Rev.
Diffractive photoproduction of opposite-charge pseudoscalar meson pairs at high energies
We calculate the cross section for diffractive photoproduction of
opposite-charge pseudoscalar meson pairs , ,
and in a broad range of center-of-mass energies relevant
for GlueX/Hall D, FOCUS, COMPASS and HERA experiments. In the case of
production we find that the interference of the resonance
and the two-pion continuum leads to a considerable deformation of the shape of
in agreement with the data from the ZEUS collaboration. We also
discuss the spectral shape of the as a function of the momentum
transfer and the contribution of higher partial waves to the mass
spectrum. We predict a sizeable energy-dependent forward-backward asymmetry in
the Gottfried-Jackson frame. For the heavy meson production we find that the
cross section for diffractive production increases much slower than the one for
open charm or bottom production. We discuss lower and upper limits for the
cross sections for diffractive production of and pairs,
which we find can be as large as 10% of the open flavor production.Comment: 14 pages, 19 figure
Pengaruh Dari Penggunaan Superplasticizer Terhadap Rheology Pasta Dan Mortar Dengan Cementitious Materials
Tercapainya kualitas dari suatu beton merupakan hal yang paling utama. Dalam proses pembuatan suatu beton banyak faktor yang mempengaruhi kualitas beton seperti air, aggregat, admixture, dan cementitious materials. Suatu campuran beton biasa yang menggunakan air, semen, aggregat halus, dan aggregat kasar masih terdapat banyak rongga – rongga, cementious material seperti silica fume dapat mengisi rongga tersebut sehingga didapatkan campuran yang lebih padat. Selain hal tersebut, pada penelitian ini mengukur kualitas dari mortar untuk menentukan sifat dari beton segar seperti kelecakan, berat jenis, kehilangan berat, dan kuat tekan dalam beton. Rheology suatu campuran dipengaruhi oleh rasio dari volume air dan powder (Vw/Vp) dan juga penggunaan superplasticizer. Penelitian dalam skala kecil ini harus lebih diperhatikan setiap material yang dipakai dan proses pelaksanaanya.Pada penelitian ini didapat bahwa campuran Mortar dengan tambahan fly ash paling menghasilkan Perubahan diameter dan kuat tekan yang bagus, hal ini disebabkan fly ash memiliki kebutuhan air yang sedikit jika dibandingkan dengan campuran Mortar saja ataupun dengan penambahan silica fume
Nonlinear mechanics with photonic crystal nanomembranes
Optomechanical systems close to their quantum ground state and nonlinear
nanoelectromechanical systems are two hot topics of current physics research.
As high-reflectivity and low mass are crucial features to improve
optomechanical coupling towards the ground state, we have designed, fabricated
and characterized photonic crystal nanomembranes, at the crossroad of both
topics. Here we demonstrate a number of nonlinear effects with these membranes.
We first characterize the nonlinear behavior of a single mechanical mode and we
demonstrate its nonlocal character by monitoring the subsequent
actuation-related frequency shift of a different mode. We then proceed to study
the underlying nonlinear dynamics, both by monitoring the phase-space
trajectory of the free resonator and by characterizing the mechanical response
in presence of a strong pump excitation. We observe in particular the frequency
evolution during a ring-down oscillation decay, and the emergence of a phase
conjugate mechanical response to a weaker probe actuation. Our results are
crucial to understand the full nonlinear features of the PhC membranes, and
possibly to look for nonlinear signatures of the quantum dynamics
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