994 research outputs found
Power Reduction of Acetic Acid to the Heavy Metal of Blood Cockle (Anadara Granosa)
This study aimed to reduce levels of heavy metals contained in the body ofblood cockle (Anadara granosa) with acetic acid soaking method. The experimentaldesign used in this study is a randomized block design (RAK) with 4 levelstreatments, blood cockle without soaking, the addition of 5% acetic acid, 15% and25%. The highest reducing power contained in Pb with 25 % acetic acid soaking, theCu with 5 % acetic acid soaking, the metal Zn with 25 % acetic acid soaking and Cdmetal with 25 % acetic acid soaking. The highest organoleptic assessment containedin such a test is the 25 % acetic acid soaking (16.58), aroma aroma is in control(15.96) and the texture is in control (17.88)
Analysis of Ticonderoga Class Cruiser operating targets for other consumables, repair parts, and administrative expenditures
MBA Professional ReportThe purpose of this project is to analyze Ticonderoga Class Cruiser Operating Targets (OPTAR) for the Atlantic Fleet (LANTFLT) and the Pacific Fleet (PACFLT). The scope of the analysis focused on the Ticonderoga Class Cruisers - the surface combatants with the least amount of configuration differences among the class. This project was conducted with the sponsorship and assistance of Commander Naval Surface Forces (CNSF). The goal of this project is to provide CNSF with underlying causes which explain lower expenditures for LANTFLT than PACFLT in the sub accounts of Other Consumable (SO), Repair (SR), and Administrative (SX). Due to levels of data available and the proportion of total expenditures that each sub-account represented, the emphasis of the analysis was concentrated on the Other Consumable and the Repair Parts Sub-accounts. The project developed a methodology to analyze expenditures within the cruiser class by three different levels; the sub-account level, the expense element level, and the system level. The cruisers were classified into groups based on their fleet, homeport, area classification (OCONUS or CONUS), and baseline configuration, at the sub-account and expense element level to see if there were relationships within the different groupings.http://archive.org/details/analysisofticond1094510344Approved for public release; distribution is unlimited
Weight loss and microstructural studies of stressed mild steel in apple juice
This study investigated the effect of internal stress of mild steel on its corrosion behaviour in apple juice by weight loss and microstructural analyses....read full pape
Particle Energization in an Expanding Magnetized Relativistic Plasma
Using a 2-1/2-dimensional particle-in-cell (PIC) code to simulate the
relativistic expansion of a magnetized collisionless plasma into a vacuum, we
report a new mechanism in which the magnetic energy is efficiently converted
into the directed kinetic energy of a small fraction of surface particles. We
study this mechanism for both electron-positron and electron-ion (mi/me=100, me
is the electron rest mass) plasmas. For the electron-positron case the pairs
can be accelerated to ultra-relativistic energies. For electron-ion plasmas
most of the energy gain goes to the ions.Comment: 7 pages text plus 5 figures, accepted for publication by Physical
Review Letter
Design Rules for Self-Assembly of 2D Nanocrystal/Metal-Organic Framework Superstructures.
We demonstrate the guiding principles behind simple two dimensional self-assembly of MOF nanoparticles (NPs) and oleic acid capped iron oxide (Fe3 O4 ) NCs into a uniform two-dimensional bi-layered superstructure. This self-assembly process can be controlled by the energy of ligand-ligand interactions between surface ligands on Fe3 O4 NCs and Zr6 O4 (OH)4 (fumarate)6 MOF NPs. Scanning transmission electron microscopy (TEM)/energy-dispersive X-ray spectroscopy and TEM tomography confirm the hierarchical co-assembly of Fe3 O4 NCs with MOF NPs as ligand energies are manipulated to promote facile diffusion of the smaller NCs. First-principles calculations and event-driven molecular dynamics simulations indicate that the observed patterns are dictated by combination of ligand-surface and ligand-ligand interactions. This study opens a new avenue for design and self-assembly of MOFs and NCs into high surface area assemblies, mimicking the structure of supported catalyst architectures, and provides a thorough fundamental understanding of the self-assembly process, which could be a guide for designing functional materials with desired structure
Gamma-rays from Galactic Black Hole Candidates with Stochastic Particle Acceleration
We consider stochastic particle acceleration in plasmas around stellar mass
black holes to explain the emissions above 1 MeV from Galactic black hole
candidates. We show that for certain parameter regimes, electrons can overcome
Coulomb losses and be accelerated beyond the thermal distribution to form a new
population, whose distribution is broad and usually not a power law; the peak
energy of the distribution is determined by the balance between acceleration
and cooling, with particles piling up around it. Radiation by inverse Compton
scattering off the thermal (from background) and non-thermal (produced by
acceleration) particles can in principle explain the hard X-ray to gamma-ray
emissions from black hole candidates. We present model fits of Cyg X-1 and GRO
J0422 in 50 keV -- 5 MeV region observed with OSSE and COMPTEL.Comment: 2 figures, to appear in March 20 of ApJ
Reflections on the concepts of Religious Teaching and Spiritual Orientation with children and young people
O presente trabalho visa discutir os conceitos de ensino religioso e orientação espiritual com crianças, adolescentes e jovens, evidenciando as confusões conceituais encontradas em artigos brasileiros e estrangeiros sobre o tema. ApĂłs uma pesquisa preliminar, desenvolvida pelos autores em uma instituição religiosa brasileira, o CEBUDV – Centro EspĂrita Beneficente UniĂŁo do Vegetal, tambĂ©m conhecida por UDV, UniĂŁo do Vegetal, verificou-se tambĂ©m pouca clareza conceitual entre os participantes desta sociedade religiosa. A partir dos resultados, foi feito um trabalho com pais e responsáveis institucionais sobre esses conceitos, resultando no clareamento conceitual e pela escolha da terminologia Orientação Espiritual com crianças, adolescentes e jovens na UDVThe present work intends to discuss the concepts of religious education and spiritual orientation with children and teenagers, displaying the conceptual misunderstandings found in Brazilian and foreigners articles about the theme. After a preliminary research, developed by the authors in a Brazilian religious institution, the CEBUDV – Centro EspĂrita Beneficente UniĂŁo do Vegetal, also known as UDV, UniĂŁo do Vegetal, it was verify to exist little conceptual clarity between the participants of this spiritual practice. Within the results, it was done a work with the parents and institutional representatives about these concepts, resulting in conceptual understandings and in the selection of the terminology spiritual orientation with children and teenagers in the UDV
IK-FA, a new heuristic inverse kinematics solver using firefly algorithm
In this paper, a heuristic method based on Firefly Algorithm is proposed for inverse kinematics problems in articulated robotics. The proposal is called, IK-FA. Solving inverse kinematics, IK, consists in finding a set of joint-positions allowing a specific point of the system to achieve a target position. In IK-FA, the Fireflies positions are assumed to be a possible solution for joints elementary motions. For a robotic system with a known forward kinematic model, IK-Fireflies, is used to generate iteratively a set of joint motions, then the forward kinematic model of the system is used to compute the relative Cartesian positions of a specific end-segment, and to compare it to the needed target position. This is a heuristic approach for solving inverse kinematics without computing the inverse model. IK-FA tends to minimize the distance to a target position, the fitness function could be established as the distance between the obtained forward positions and the desired one, it is subject to minimization. In this paper IK-FA is tested over a 3 links articulated planar system, the evaluation is based on statistical analysis of the convergence and the solution quality for 100 tests. The impact of key FA parameters is also investigated with a focus on the impact of the number of fireflies, the impact of the maximum iteration number and also the impact of (a, Ăź, Âż, d) parameters. For a given set of valuable parameters, the heuristic converges to a static fitness value within a fix maximum number of iterations. IK-FA has a fair convergence time, for the tested configuration, the average was about 2.3394 Ă— 10-3 seconds with a position error fitness around 3.116 Ă— 10-8 for 100 tests. The algorithm showed also evidence of robustness over the target position, since for all conducted tests with a random target position IK-FA achieved a solution with a position error lower or equal to 5.4722 Ă— 10-9.Peer ReviewedPostprint (author's final draft
Ascaroside Expression in Caenorhabditis elegans Is Strongly Dependent on Diet and Developmental Stage
Background:
The ascarosides form a family of small molecules that have been isolated from cultures of the nematode Caenorhabditis elegans. They are often referred to as “dauer pheromones” because most of them induce formation of long-lived and highly stress resistant dauer larvae. More recent studies have shown that ascarosides serve additional functions as social signals and mating pheromones. Thus, ascarosides have multiple functions. Until now, it has been generally assumed that ascarosides are constitutively expressed during nematode development.
Methodology/Principal Findings:
Cultures of C. elegans were developmentally synchronized on controlled diets. Ascarosides released into the media, as well as stored internally, were quantified by LC/MS. We found that ascaroside biosynthesis and release were strongly dependent on developmental stage and diet. The male attracting pheromone was verified to be a blend of at least four ascarosides, and peak production of the two most potent mating pheromone components, ascr#3 and asc#8 immediately preceded or coincided with the temporal window for mating. The concentration of ascr#2 increased under starvation conditions and peaked during dauer formation, strongly supporting ascr#2 as the main population density signal (dauer pheromone). After dauer formation, ascaroside production largely ceased and dauer larvae did not release any ascarosides. These findings show that both total ascaroside production and the relative proportions of individual ascarosides strongly correlate with these compounds' stage-specific biological functions.
Conclusions/Significance:
Ascaroside expression changes with development and environmental conditions. This is consistent with multiple functions of these signaling molecules. Knowledge of such differential regulation will make it possible to associate ascaroside production to gene expression profiles (transcript, protein or enzyme activity) and help to determine genetic pathways that control ascaroside biosynthesis. In conjunction with findings from previous studies, our results show that the pheromone system of C. elegans mimics that of insects in many ways, suggesting that pheromone signaling in C. elegans may exhibit functional homology also at the sensory level. In addition, our results provide a strong foundation for future behavioral modeling studies
Effective Dynamics in Bianchi Type II Loop Quantum Cosmology
We numerically investigate the solutions to the effective equations of the
Bianchi II model within the "improved" Loop Quantum Cosmology (LQC) dynamics.
The matter source is a massless scalar field. We perform a systematic study of
the space of solutions, and focus on the behavior of several geometrical
observables. We show that the big-bang singularity is replaced by a bounce and
the point-like singularities do not saturate the energy density bound. There
are up to three directional bounces in the scale factors, one global bounce in
the expansion, the shear presents up to four local maxima and can be zero at
the bounce. This allows for solutions with density larger than the maximal
density for the isotropic and Bianchi I cases. The asymptotic behavior is shown
to behave like that of a Bianchi I model, and the effective solutions connect
anisotropic solutions even when the shear is zero at the bounce. All known
facts of Bianchi I are reproduced. In the "vacuum limit", solutions are such
that almost all the dynamics is due to the anisotropies. Since Bianchi II plays
an important role in the Bianchi IX model and the Belinskii, Khalatnikov,
Lifshitz (BKL) conjecture, our results can provide an intuitive understanding
of the behavior in the vicinity of general space-like singularities, when
loop-geometric corrections are present.Comment: 24 pages, 26 figure
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