1,492 research outputs found
The CCFM uPDF evolution uPDFevolv
uPDFevolv is an evolution code for TMD parton densities using the CCFM
evolution equation. A description of the underlying theoretical model and
technical realization is given together with a detailed program description,
with emphasis on parameters the user may want to changeComment: Code and description on https://updfevolv.hepforge.org Version to be
published in EPJ
Polarized Deeply Inelastic Scattering (DIS) Structure Functions for Nucleons and Nuclei
We extract parton distribution functions (PDFs) and structure functions from
recent experimental data of polarized lepton-DIS on nucleons at next-to-leading
order (NLO) Quantum Chromodynamics. We apply the Jacobi polynomial method to
the DGLAP evolution as this is numerically efficient. Having determined the
polarized proton and neutron spin structure, we extend this analysis to
describe 3He and 3H polarized structure functions, as well as various sum
rules. We compare our results with other analyses from the literature.Comment: LaTeX, 12 pages, 11 figures, 6 tables. Update to match published
versio
A class of extremising sphere-valued maps with inherent maximal tori symmetries in SO(n)
In this paper we consider an energy functional depending on the norm of the gradient and seek to extremise it over an admissible class of Sobolev maps defined on an annulus and taking values on the unit sphere whilst satisfying suitable boundary conditions. We establish the existence of an infinite family of solutions with certain symmetries to the associated nonlinear Euler-Lagrange system in even dimensions and discuss the stability of such extremisers by way of examining the positivity of the second variation of the energy at these solutions
Enhancement in Electro-Optic Properties of Dynamic Scattering Systems through Addition of Dichroic Dyes
Electro-optic properties of dynamic scattering in homeotropically aligned
pure and dichroic dye-doped nematic liquid crystal samples are examined. The
optical properties of the two systems are quantified using transmission
properties of scattered and unscattered as a function of amplitude and
frequency of an applied voltage. Auto-correlation of the scattered signal at
different applied voltages is used to compare the decay times in the two
systems. Lastly, the histogram of the scattered signal reveals a wavevector
dependent large light scattering event. The dye-doped system shows a
significant enhancement of light blocking property in both normal and off-axis
light propagation. The characteristics of the system are compared to other
scattering technologies. The results suggest that dye-doped system can overcome
shortcomings in scattering based devices used for near-eye applications
In-vitro application of pentoxifylline preserved ultrastructure of spermatozoa after vitrification in asthenozoospermic patients
Abstract
PURPOSE:
To evaluate the effect of in vitro application of pentoxifylline (PX) on sperm parameters and ultrastructure after vitrification in asthenozoospermic patients.
MATERIALS AND METHODS:
A total of 30 asthenozoospermic semen samples (aged 25-45 years) were divided into four groups before vitrification, after vitrification, control (without PX) and experimental (with PX). In experimental group, each sample was exposed for 30 min to 3.6mmol/l PX and the control group without any treatment apposing in 370C for 30 min. After incubation, the samples were washed and analyzed again. Vitrification was done according to straw method. Eosin-nigrosin and Papanicolaou staining were applied for assessment of sperm viability and morphology, respectively. The samples without PX and post treatment with PX were assessed by transmission electron microscopy (TEM).
RESULTS:
A significant decrease in sperm motility (P ≤ .001), morphology (11.47 ± 2.9 versus 6.73 ± 2.01) and viability (73.37 ± 6.26 versus 54.67 ± 6.73) was observed post vitrification, but sperm motility (19.85 ± 4.75 versus 32.07 ± 5.58, P ≤ .001) was increased significantly following application of PX. This drug had no significant (P >.05) detrimental neither negative effect on ultrastructure acrosome, plasma membrane and coiled tail statues of spermatozoa.
CONCLUSION:
Vitrification had detrimental effects on sperm parameters, but PX reversed detrimental effects on sperm motility. However, PX had no alteration on ultrastructure morphology of human spermatozoa after vitrification
Aflatoxin contamination in wheat flour samples from Golestan province, Northeast of Iran
Background: Due to the high toxicity of aflatoxin and its effects on public health, determination of aflatoxin level in Wheat flour samples in the Golestan province, north of Iran was investigated. To examine the effect of seasonal changes, summer and winter sampling was performed with standard sampling methods. Methods: A total of 200 flour samples were collected from 25 factories. HPLC method with immunoaffinity chromatography was used to measure aflatoxin types (G2, G1, B2 and B1). Statistical analysis was performed by the Pearson correlation test, One-way ANOVA and multivariate regression analysis. Results: Mean total aflatoxin levels of samples were 0.82 and 1.99 ng/g in summer and winter, respectively. Aflatoxin B1 levels were detected in 3.1%, 7.4% over permissible limits by worldwide regulations in samples collected in summer and winter, respectively. Aflatoxins in winter were higher than summer. The highest frequency of aflatoxin contamination in winter was B2 (98%) and in summer G1 (51%). The relationship between humidity and rate of aflatoxin B1 and total aflatoxin was significant in winter. Results of multivariate regression were showed the strongest relationship with humidity and aflatoxin level. Despite the contamination of flour samples, there was no contamination higher than the standard limit of Iran Standard Institute. But it was significantly higher than similar studies from other regions. Conclusions: Therefore, with regard to negative impacts of aflatoxin on health, aflatoxin contamination should be considered in future programs. Decrease of aflatoxin contamination may be made practical through reducing wheat storage duration and controlling humidity
Space shuttle electromagnetic environment experiment. Phase A: Definition study
A program is discussed which develops a concept for measuring the electromagnetic environment on earth with equipment on board an orbiting space shuttle. Earlier work on spaceborne measuring experiments is reviewed, and emissions to be expected are estimated using, in part, previously gathered data. General relations among system parameters are presented, followed by a proposal on spatial and frequency scanning concepts. The methods proposed include a nadir looking measurement with small lateral scan and a circularly scanned measurement looking tangent to the earth's surface at the horizon. Antenna requirements are given, assuming frequency coverage from 400 MHz to 40 GHz. For the low frequency range, 400-1000 MHz, a processed, thinned array is proposed which will be more fully analyzed in the next phase of the program. Preliminary hardware and data processing requirements are presented
Negotiation, bargaining, and discounts:generating WoM and local tourism development at the Tabriz bazaar, Iran
This paper examines the effects of negotiation intention, bargaining propensity, and discount satisfaction on word-of-mouth (WoM) behaviours for tourists visiting Tabriz bazaar, Iran. Data from 615-survey respondents highlight that tourists are motivated to conduct WoM behaviour when they are experientially satisfied with the opportunity to negotiate and bargain, and when they are satisfied with the discount they receive. This paper makes theoretical contributions to social exchange theory and presents managerial implications for policy-makers to generate tourism development
Evolutionary algorithm-based multi-objective task scheduling optimization model in cloud environments
© 2015, Springer Science+Business Media New York. Optimizing task scheduling in a distributed heterogeneous computing environment, which is a nonlinear multi-objective NP-hard problem, plays a critical role in decreasing service response time and cost, and boosting Quality of Service (QoS). This paper, considers four conflicting objectives, namely minimizing task transfer time, task execution cost, power consumption, and task queue length, to develop a comprehensive multi-objective optimization model for task scheduling. This model reduces costs from both the customer and provider perspectives by considering execution and power cost. We evaluate our model by applying two multi-objective evolutionary algorithms, namely Multi-Objective Particle Swarm Optimization (MOPSO) and Multi-Objective Genetic Algorithm (MOGA). To implement the proposed model, we extend the Cloudsim toolkit by using MOPSO and MOGA as its task scheduling algorithms which determine the optimal task arrangement among VMs. The simulation results show that the proposed multi-objective model finds optimal trade-off solutions amongst the four conflicting objectives, which significantly reduces the job response time and makespan. This model not only increases QoS but also decreases the cost to providers. From our experimentation results, we find that MOPSO is a faster and more accurate evolutionary algorithm than MOGA for solving such problems
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