KAJIAN SEDIMENTASI DI SUNGAI SAMPEAN BONDOWOSO MENGGUNAKAN PROGRAM HEC-RAS VERSI 4.1

Sedimentasi sungai yaitu proses pengendapan suatu material – material yang terangkut aliran air sungai dan dapat mengakibatkan terjadinya delta sungai, sedangkan sedimen merupakan batuan yang terbentuk karena proses pelapukan, erosi, transportasi, dan deposisi (pengerasan) yang terjadi pada suatu wilayah aliran sungai. Delta sungai yang terjadi karena proses sedimentasi tersebut dapat mengurangi jumlah debit air yang terbawa, sehingga kebutuhan irigasi di daerah hilir tidak bisa terpenuhi secara maksimal karena terhalang oleh penumpukan delta. Karakteristik sedimentasi di hilir terjadi perlahan dan berlangsung menerus selama suplai muatan sedimen yang tinggi terus berlangsung. Prediksi sedimentasi yang terjadi pada sungai dilakukan dengan memperhitungkan besar laju sedimentasi berdasarkan metode perhitungan analitik, namun untuk mempermudah dalam menggambarkan sedimentasi yang terjadi pada sungai  sampean  Bondowoso  dilakukan  metode  pemodelan  menggunakan  progam  aplikasi HEC-RAS. Progam HEC-RAS sendiri merupakan salah satu progam pemodelan analisis angkutan sedimen pada saluran maupun sungai

Evaluation of biological control agents for mosquitoes control in artificial breeding places

ObjectiveTo evaluate the entomological impact of chlorpyrifos-methyl, Bacillus thuringiensis, and Gambusia affinis on mosquitoes control in artificial breeding places.MethodsA Latin square design with 4 replicates was performed in order to evaluate the efficacy of chlorpyrifosmethyl, Bacillus thuringiensis, and Gambusia affinis on larva. The larvicide was applied at the dosage of 100 mg a.h/ha, Bacillus thuringiensis at the recommended dosage and 10 fishes per m2 were applied at 1×1 m2 artificial breeding sites. The larval densities for both anopheline and culicine were counted according to larvae /10 dippers prior and 24 h after application.ResultsAll three control agents are effective for mosquito density reduction, and the difference between the three agents and the control is significant (P<0.05). There is also significant difference among chlorpyrifos-methyl, Bacillus thuringiensis and Gambusia affinis. Bacillus thuringiensis exhibited more reduction on mosquito larval density than fish and larvicide (P<0.05).ConclusionsBacillus thuringiensis in comparison with two other agents is the appropriate method for larviciding in the breeding places. Although long term assessing for biological activities as well as monitoring and mapping of resistance is required

Determination of correlation coefficients for RazakSAT received signals

RazakSAT is the second Malaysian Earth observation satellite operating with downlink frequency of 2.232 GHz (S-band). RazakSAT’s received signals had been recorded in percentage unit and the values are required be quantified in the common signal strength unit, dBm. This paper details how such has been achieved. Measurements were carried out in order to establish the correlation between the percentage values and dBm values. The campaign involved the setting-up of a terrestrial microwave link transmission comprised of a transmitter, a receiver, and relevant antennas at about 500 m displacement. The transmitted power was controlled with the use of a signal generator and the received power level was measured using a spectrum analyzer. Appropriate coefficients for the correlation had been determined. The slope coefficient, m has been derived to have the value of 0.7765 and its slope intercept coefficient, c has the value of 85.301. Using these coefficients, the received satellite signals can then be converted into dBm

Propagation measurements during Daytime for RazakSAT S-band space to earth satellite signal transmission

Two novel quinazoline derivatives named as; 3-[(4-hydroxy-3-methoxy-benzylidene)-amino]-2-ptolyl-3H-quinazolin-4-one (5) and 2-p-Tolyl-3-[3,4,5-trimethoxy-benzylidene-amino]-3H-quinazolin-4- one (6) in addition to one acetamide derivative named as 2-(2-Hydroxycarbonylphenylamino)-N-(4- aminosulphonylphenyl) 11 were synthesized, and evaluated for their anti-ulcerogenic & AntiUlcerative colitis activities. All of the three compounds showed curative activity against acetic acid induced ulcer model at a dose of 50 mg/kg, they produced 65%, 85% & 57.74% curative ratio for compounds 5, 6 & 11 respectively. The effect of the tested compounds 5, 6 & 11 at dose 50 mg/kg were significantly (P < 0.01) more effective than dexamesathone (0.1 mg/kg) in reducing all parameters. Compounds showed curative activity of for peptic ulcer (induced by absolute alcohol (at a dose of 50 mg/kg, it produced Curative of control ulcer 56.00%, 61.70% & 87.1% for compounds 5, 6 & 11 respectively at dose 50 mg/kg, while the standard drug (Omeprazole 20 mg/kg) produced 33.3%. In both tests, the activity of our target compounds were higher than the standard drugs used for treatment of peptic ulcer and ulcerative colitis. No side effects were reported on liver and kidney functions upon prolonged oral administration of this compounds. (C) 2017 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University

Cluster Galaxies Die Hard

We investigate how the specific star formation rates of galaxies of different masses depend on cluster-centric radius and on the central/satellite dichotomy in both field and cluster environments. Recent data from a variety of sources, including the cluster catalogue of von der Linden et al. are compared to the semi-analytic models of De Lucia & Blaizot. We find that these models predict too many passive satellite galaxies in clusters, too few passive central galaxies with low stellar masses, and too many passive central galaxies with high masses. We then outline a series of modifications to the model necessary to solve these problems: a) Instead of instantaneous stripping of the external gas reservoir after a galaxy becomes a satellite, the gas supply is assumed to decrease at the same rate that the surrounding halo loses mass due to tidal stripping, b) The AGN feedback efficiency is lowered to bring the fraction of massive passive centrals in better agreement with the data. We also allow for radio mode AGN feedback in satellite galaxies. c) We assume that satellite galaxies residing in host haloes with masses below 10^12 M_sun do not undergo any stripping. We highlight the fact that in low mass galaxies, the external reservoir is composed primarily of gas that has been expelled from the galactic disk by supernovae driven winds. This gas must remain available as a future reservoir for star formation, even in satellite galaxies. Finally, we present a simple recipe for the stripping of gas and dark matter in satellites that can be used in models where subhalo evolution is not followed in detail.Comment: Models of ram-pressure stripping and some extra discussion added, references added. Conclusions unchanged. 20 pages, 15 figures. Accepted for publication in MNRAS

An OSIRIS study of the gas kinematics in a sample of UV-selected galaxies: Evidence of "Hot and Bothered" starbursts in the local Universe

We present data from Integral Field Spectroscopy for 3 supercompact UV-Luminous Galaxies (ScUVLGs). As nearby (z~0.2), compact (R_50~1-2 kpc), bright Paschen-alpha sources, with unusually high star formation rates (SFR=3-100 M_sun/yr), ScUVLGs are an ideal population for studying detailed kinematics and dynamics in actively star-forming galaxies. In addition, ScUVLGs appear to be excellent analogs to high redshift Lyman Break Galaxies (LBGs) and our results may offer additional insight into the dynamics of LBGs. Previous work by our team has shown that the morphologies of these galaxies exhibit tidal features and companions, and in this study we find that the dynamics of ScUVLGs are dominated by disturbed kinematics of the emission line gas-- suggestive that these galaxies have undergone recent feedback, interactions or mergers. While 2 of the 3 galaxies do display rotation, v/sigma < 1 -- suggesting dispersion dominated kinematics rather than smooth rotation. We also simulate how these observations would appear at z~2. Lower resolution and loss of low surface brightness features causes some apparent discrepancies between the low-z (observed) and high-z (simulated) interpretations and quantitatively gives different values for v/sigma, yet simulations of these low-z analogs manage to detect the brightest regions well and resemble actual high-z observations of LBGs.Comment: 4 pages, 4 figures (bitmapped), accepted for publication in ApJ

Interpreting the Evolution of the Size - Luminosity Relation for Disk Galaxies from Redshift 1 to the Present

A sample of very high resolution cosmological disk galaxy simulations is used to investigate the evolution of galaxy disk sizes back to redshift 1 within the Lambda CDM cosmology. Artificial images in the rest frame B band are generated, allowing for a measurement of disk scale lengths using surface brightness profiles as observations would, and avoiding any assumption that light must follow mass as previous models have assumed. We demonstrate that these simulated disks are an excellent match to the observed magnitude - size relation for both local disks, and for disks at z=1 in the magnitude/mass range of overlap. We disentangle the evolution seen in the population as a whole from the evolution of individual disk galaxies. In agreement with observations, our simulated disks undergo roughly 1.5 magnitudes/arcsec^2 of surface brightness dimming since z=1. We find evidence that evolution in the magnitude - size plane varies by mass, such that galaxies with M* > 10^9 M_sun undergo more evolution in size than luminosity, while dwarf galaxies tend to evolve potentially more in luminosity. The disks grow in such a way as to stay on roughly the same stellar mass - size relation with time. Finally, due to an evolving stellar mass - SFR relation, a galaxy at a given stellar mass (or size) at z=1 will reside in a more massive halo and have a higher SFR, and thus a higher luminosity, than a counterpart of the same stellar mass at z=0.Comment: Version resubmitted to ApJ, after referee's comment

The Degeneracy of Galaxy Formation Models

We develop a new formalism for modeling the formation and evolution of galaxies within a hierarchical universe. Similarly to standard semi-analytical models we trace galaxies inside dark-matter merger-trees. The formalism includes treatment of feedback, star-formation, cooling, smooth accretion, gas stripping in satellite galaxies, and merger-induced star bursts. However, unlike in other models, each process is assumed to have an efficiency which depends only on the host halo mass and redshift. This allows us to describe the various components of the model in a simple and transparent way. By allowing the efficiencies to have any value for a given halo mass and redshift, we can easily encompass a large range of scenarios. To demonstrate this point, we examine several different galaxy formation models, which are all consistent with the observational data. Each model is characterized by a different unique feature: cold accretion in low mass haloes, zero feedback, stars formed only in merger-induced bursts, and shutdown of star-formation after mergers. Using these models we are able to examine the degeneracy inherent in galaxy formation models, and look for observational data that will help to break this degeneracy. We show that the full distribution of star-formation rates in a given stellar mass bin is promising in constraining the models. We compare our approach in detail to the semi-analytical model of De Lucia & Blaizot. It is shown that our formalism is able to produce a very similar population of galaxies once the same median efficiencies per halo mass and redshift are being used. We provide a public version of the model galaxies on our web-page, along with a tool for running models with user-defined parameters. Our model is able to provide results for a 62.5 h^{-1} Mpc box within just a few seconds.Comment: Accepted for publication in MNRAS. Fig 6 & 7 corrected. For the project page which allows running your own model, see http://www.mpa-garching.mpg.de/galform/sesam

Permeance Based Algorithm For Computation Of Flux Linkage Characteristics Of Non-Linear 6/4 Switched Reluctance Motor (SRM)

The concept of permeance is used in the analysis of flux linkage of 6/4 SRM. The aim of this paper is to develop an efficient algorithm exploiting the nonlinear feature of the 6/4 SRM using the aforementioned concept of permeance. The first step is to generate the relevant equations related to permeances of the 6/4 SRM under study. The 6/4 SRM’s magnetization curve is then derived from the summation of mmf drops at various blocks representing the motor. The air gap permeances are derived at various angles and 3-D leakage effects are taken into account. These permeances are used for the mmf drop computation. The algorithm is capable of efficiently computing mmf drop at every block to consequently yield a complete accurate nonlinear flux linkage feature of the 6/4 switched reluctance motor. In this way, the capability of the SRM to produce the expected four times the specific output torque due to operation in high saturation region compared to an equivalent induction motor as special the attribute of the SRM is demonstrated

Galactic star formation and accretion histories from matching galaxies to dark matter haloes

We present a new statistical method to determine the relationship between the stellar masses of galaxies and the masses of their host dark matter haloes over the entire cosmic history from z~4 to the present. This multi-epoch abundance matching (MEAM) model self-consistently takes into account that satellite galaxies first become satellites at times earlier than they are observed. We employ a redshift-dependent parameterization of the stellar-to-halo mass relation to populate haloes and subhaloes in the Millennium simulations with galaxies, requiring that the observed stellar mass functions at several redshifts be reproduced simultaneously. Using merger trees extracted from the dark matter simulations in combination with MEAM, we predict the average assembly histories of galaxies, separating into star formation within the galaxies (in-situ) and accretion of stars (ex-situ). The peak star formation efficiency decreases with redshift from 23% at z=0 to 9% at z=4 while the corresponding halo mass increases from 10^11.8M\odot to 10^12.5M\odot. The star formation rate of central galaxies peaks at a redshift which depends on halo mass; for massive haloes this peak is at early cosmic times while for low-mass galaxies the peak has not been reached yet. In haloes similar to that of the Milky-Way about half of the central stellar mass is assembled after z=0.7. In low-mass haloes, the accretion of satellites contributes little to the assembly of their central galaxies, while in massive haloes more than half of the central stellar mass is formed ex-situ with significant accretion of satellites at z<2. We find that our method implies a cosmic star formation history and an evolution of specific star formation rates which are consistent with those inferred directly. We present convenient fitting functions for stellar masses, star formation rates, and accretion rates as functions of halo mass and redshift.Comment: 20 pages, 12 figures, 1 table, submitted to MNRA