oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 55 )

2018 ( 141 )

2017 ( 125 )

2016 ( 156 )

Custom range...

Search Results: 1 - 10 of 84398 matches for " W. Mouhali "
All listed articles are free for downloading (OA Articles)
Page 1 /84398
Display every page Item
Evidence of a cyclonic regime in a precessing cylindrical container
W. Mouhali,T. Lehner,J. Léorat,R. Vitry
Physics , 2014,
Abstract: We report experimental observations obtained by particule image velocimetry (PIV) of the behavior of a flow driven by rotation and precession of a cylindrical container. Various hydrodynamical regimes are identified according to the value of the control parameter which is the ratio of the precession frequency to the rotation frequency. In particular when this parameter is increased from small values, we have observed an induced differential rotation followed by the apparition of permanent cyclonic vortices.
Bauxit
. W.
Nieuwe West-Indische Gids , 1951,
Abstract:
Creation of High Energy/Intensity Bremsstrahlung by a Multi-Target and Focusing of the Scattered Electrons by Small-Angle Backscatter at a Cone Wall and a Magnetic Field—Enhancement of the Outcome of Linear Accelerators in Radiotherapy  [PDF]
W. Ulmer
International Journal of Medical Physics,Clinical Engineering and Radiation Oncology (IJMPCERO) , 2013, DOI: 10.4236/ijmpcero.2013.24020
Abstract: The yield of bremsstrahlung (BS) from collisions of fast electrons (energy at least 6 MeV) with a Tungsten target can be significantly improved by exploitation of Tungsten wall scatter in a multi-layered target. A simplified version of a previously developed principle is also able to focus on small angle scattered electrons by a Tungsten wall. It is necessary that the thickness of each Tungsten layer does not exceed 0.04 mm—a thickness of 0.03 mm is suitable for accelerators in medical physics. Further focusing of electrons results from suitable magnetic fields with field strength between 0.5 Tesla and 1.2 Tesla (if the cone with multi-layered targets is rather narrow). Linear accelerators in radiation therapy only need to be focused by wall scatter without further magnetic fields (a standard case: 31 plates with 0.03 mm thickness and 1 mm distance between the plates). We considered three cases with importance in medical physics: A very small cone with an additional magnetic field for focusing (the field diameter at 90 cm depth: 6 cm), a medium cone with an optional magnetic field (field diameter at 90 cm depth: 13 cm) and a broad cone without a magnetic field (
Social Issues of Urban Road Rehabilitation  [PDF]
W. Supul
Current Urban Studies (CUS) , 2018, DOI: 10.4236/cus.2018.63022
Abstract:
This study highlights the social issues of an urban road confronted after the recent rehabilitation works. The study reveals that the road has facilitated faster travel with rider comfort but does not provide a very safe place for residents, children of the kindergarten and school and, walkers. The study has identified several social impacts caused by rehabilitation such as walker and resident un-comfort, inconvenience for businesses, not abating environmental pollution, absence of facilities for disable people and several more. Because the road platform is devoid of trees, the motorists, residents and pedestrians are stripped off of an array of benefits. Nor the road design has considered the comfort of walkers especially disable, elderly, sick and children by not providing a fully connected road walkway and not providing any tree shade and benches to have a rest on a hot and sunny day. The road has also not addressed environmental concerns especially the mechanisms for reduction of impacts of particle and other noxious gases emanating from motor vehicle movement on inhabitants. A method to analyze road impacts is included that serves as an aid for future rehabilitation of urban roads.
On the Origin of Mass and Angular Momentum of Stellar Objects  [PDF]
Peter C. W. Fung, K. W. Wong
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.615235
Abstract: The consequence of the 5D projection theory [1] is extended beyond the Gell-Mann Standard Model for hadrons to cover astronomical objects and galaxies. The proof of Poincare conjecture by Pe-relman’s differential geometrical techniques led us to the consequence that charged massless spinors reside in a 5D void of a galactic core, represented by either an open 5D core or a closed, time frozen, 3D × 1D space structure, embedded in massive structural stellar objects such as stars and planets. The open galactic core is obtained from Ricci Flow mapping. There exist in phase, in plane rotating massless spinors within these void cores, and are responsible for 1) the outward spiral motion of stars in the galaxy in the open core, and 2) self rotations of the massive stellar objects. It is noted that another set of eigen states pertaining to the massless charged spinor pairs rotating out of phase in 1D (out of the 5D manifold) also exist and will generate a relatively weak magnetic field out of the void core. For stars and planets, it forms the intrinsic dipole field. Due to the existence of a homogeneous 5D manifold from which we believe the universe evolves, the angular momentum arising from the rotation of the in-phase spinor pairs is proposed to be counter-balanced by the rotation of the matter in the surrounding Lorentz domain, so as to conserve net zero angular momentum. Explicit expression for this total angular momentum in terms of a number of convergent series is derived for the totally enclosed void case/core, forming in general the structure of a star or a planet. It is shown that the variables/parameters in the Lorentz space-time domain for these stellar objects involve the object’s mass M, the object’s Radius R, period of rotation P, and the 5D void radius Ro, together with the Fermi energy Ef and temperature T of the massless charged spinors residing in the void. We discovered three laws governing the relationships between Ro/R, T, Ef and the angular momentum Iω of such astronomical object of interest, from which we established two distinct regions, which we define as the First and Second Laws for the evolution of the stellar object. The Fermi energy Ef was found to be that of the electron mass, as it is the lightest massive elementary particle that could be created from pure energy in the core. In fact the mid-temperature of the transition region between the
Biopesticides and Their Role in Sustainable Agricultural Production  [PDF]
Geraldin M. W. Lengai, James W. Muthomi
Journal of Biosciences and Medicines (JBM) , 2018, DOI: 10.4236/jbm.2018.66002
Abstract: Biopesticides are derivatives of plants, microorganisms and insects. Substances from plants and animals have been used to manage diseases in crops, animals and humans. Reliance on nature to heal nature is a practise for many people around the world. Use of natural products was overtaken by synthetic chemicals due to their efficacy, reliability and quick knock down effect. However, synthetic pesticides have become a health hazards for humans and environment due to their toxicity and pollution. Biopesticides are potential alternatives to synthetic pesticides. Sources of biopesticides are readily available, easily biodegradable, exhibit various modes of action, are less expensive and have low toxicity to humans and non-target organisms. Neem, pyrethrum, cotton and tobacco are known sources of botanical pesticides and have already been commercialized. Other sources of botanical pesticides include garlic, euphorbia, citrus, pepper among others. Species of Trichoderma, Bacillus, Pseudomonas, Beauveria have been commercialized as microbial pesticides. Biopesticides are however faced with challenges of formulation, registration, commercialization, acceptance and adoption. This paper describes several aspects of biopesticide development, including but not limited to, their sources, production, formulation, commercialization, efficacy and role in sustainable agriculture.
Software Reuse: Developers’ Experiences and Perceptions  [PDF]
William W. Agresti
Journal of Software Engineering and Applications (JSEA) , 2011, DOI: 10.4236/jsea.2011.41006
Abstract: Reusing programs and other artifacts has been shown to be an effective strategy for significant reduction of development costs. This article reports on a survey of 128 developers to explore their experiences and perceptions about using other people’s code: to what extent does the “not invented here” attitude exist? The survey was structured around a novel and simple “4A” model, which is introduced in this article: for an organization to obtain any benefits from reusing code, four conditions must obtain: availability, awareness, accessibility, and acceptability. The greatest impediments to reuse were shown to be awareness of reusable code and developers’ perceptions of its acceptability for use on their new projects. For 72% of developers, the complexity of the old code was cited as a reason that the code was not reused. The survey also included developers’ suggestions for ways to take greater advantage of existing code and related artifacts.
A Critique of Recent Criticisms of Freud on Religious Belief  [PDF]
Thomas W Smythe
Open Journal of Philosophy (OJPP) , 2011, DOI: 10.4236/ojpp.2011.11002
Abstract: The paper is a critique of recent criticisms of Sigmund Freud’s theory that religion is based on wishful thinking. The criticisms made by authors such as Alvin Plantinga, John Hick, William P. Alston, William Rowe, and Merol Westphal are critically examined. I defend Freud’s critique of religion as a satisfaction of our deepest desires for a heavenly father showing inductively that those desires render religious belief as unlikely to be true.
Bias of the Random Forest Out-of-Bag (OOB) Error for Certain Input Parameters  [PDF]
Matthew W. Mitchell
Open Journal of Statistics (OJS) , 2011, DOI: 10.4236/ojs.2011.13024
Abstract: Random Forest is an excellent classification tool, especially in the –omics sciences such as metabolomics, where the number of variables is much greater than the number of subjects, i.e., “n << p.” However, the choices for the arguments for the random forest implementation are very important. Simulation studies are performed to compare the effect of the input parameters on the predictive ability of the random forest. The number of variables sampled, m-try, has the largest impact on the true prediction error. It is often claimed that the out-of-bag error (OOB) is an unbiased estimate of the true prediction error. However, for the case where n << p, with the default arguments, the out-of-bag (OOB) error overestimates the true error, i.e., the random forest actually performs better than indicated by the OOB error. This bias is greatly reduced by subsampling without replacement and choosing the same number of observations from each group. However, even after these adjustments, there is a low amount of bias. The remaining bias occurs because when there are trees with equal predictive ability, the one that performs better on the in-bag samples will perform worse on the out-of-bag samples. Cross-validation can be performed to reduce the remaining bias.
Controlling the Tax Evasion Dynamics via Majority-Vote Model on Various Topologies  [PDF]
Francisco W. S. Lima
Theoretical Economics Letters (TEL) , 2012, DOI: 10.4236/tel.2012.21017
Abstract: Within the context of agent-based Monte-Carlo simulations, we study the well-known majority-vote model (MVM) with noise applied to tax evasion on simple square lattices (LS), Honisch-Stauffer (SH), directed and undirected Bara-basi-Albert (BAD, BAU) networks. In to control the fluctuations for tax evasion in the economics model proposed by Zaklan, MVM is applied in the neighborhod of the noise critical qc to evolve the Zaklan model. The Zaklan model had been studied recently using the equilibrium Ising model. Here we show that the Zaklan model is robust because this can be studied using equilibrium dynamics of Ising model also through the nonequilibrium MVM and on various topologies cited above giving the same behavior regardless of dynamic or topology used here.
Page 1 /84398
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.