Hasil untuk "cs.CE"

Menampilkan 20 dari ~194683 hasil · dari DOAJ, arXiv, CrossRef

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CrossRef Open Access 1990
Hippocampal damage associated with prolonged glucocorticoid exposure in primates

RM Sapolsky, H Uno, CS Rebert et al.

In the laboratory rat and guinea pig, glucocorticoids (GCs), the adrenal steroids that are secreted during stress, can damage the hippocampus and exacerbate the hippocampal damage induced by various neurological insults. An open question is whether GCs have similar deleterious effects in the primate hippocampus. In fact, we showed that sustained and fatal stress was associated with preferential hippocampal damage in the vervet monkey; however, it was not possible to determine whether the excessive GC secretion that accompanied such stress was the damaging agent. The present study examines this possibility. Pellets of cortisol (the principal GC of primates) were stereotaxically implanted into hippocampi of 4 vervet monkeys; contralateral hippocampi were implanted with cholesterol pellets as a control. One year later at postmortem, preferential damage occurred in the cortisol-implanted side. In the cholesterol side, mild cell layer irregularity was noted in 2 of 4 cases. By contrast in the cortisol-exposed hippocampi, all cases had at least 2 of the following neuropathologic markers: cell layer irregularity, dendritic atrophy, soma shrinkage and condensation, or nuclear pyknosis. Damage was severe in some cases, and was restricted to the CA3/CA2 cellfield. This anatomical distribution of damage, and the cellular features of the damage agree with that observed in instances of GC-induced toxicity in the rodent hippocampus, and of stress-induced toxicity in the primate hippocampus. These observations suggest that sustained GC exposure (whether due to stress, Cushings syndrome or exogenous administration) might damage the human hippocampus.

CrossRef Open Access 2024
Plasma Gasification of a Simulated Low-Level Radioactive Waste: Co, Cs, Sr, and Ce Retention Efficiency

Juan Ariel Pullao, Franco Emmanuel Benedetto, Gian Franco Binetti Basterrechea et al.

Thermal plasma is a versatile technology that can be used to treat various types of wastes, including vegetal and mineral oils, solvents, plastics, papers and cardboard, glasses, bricks and rocks, metals, clothes, and mixtures of these materials. In this study, we utilized a commercial plasma cutter as a thermal plasma source to decrease the volume of a simulated low-level radioactive mixed solid waste. The simulated waste included papers, plastics, clothes, gloves, metals and stable Co, Cs, Sr, and Ce additives as surrogates of 60Co, 137Cs, 90Sr, and 144Ce, the latter typical contaminants in nuclear LLW. As a result of the process two products were obtained, a solid phase in which we focused this work and a gaseous phase. To retain as much as possible surrogates in the solid final phase, crushed glass from broken bottles was included as a vitrification additive to the original waste. After undergoing heat treatment, a dense vitreous slag was produced and ashes. The process resulted in a volume reduction of 70%, indicating the successful gasification of organic excess materials. The surrogate elements were retained in the process and were found in the ashes composition: Co (3.4% w/w), Cs (37.7% w/w), Ce (0.6% w/w) and in the glass matrix composition of Co, Cs, Sr and Ce: 72.4 ± 14.7, 32 ± 18.2, 125.3 ± 31.6, 80 ± 13.1 % w/w respectively. For the actual experimental conditions, retention efficiencies were estimated for Cobalt (Co) at 72.4 ± 14.7%, Cerium (Ce) at 80 ± 13.1%, Strontium (Sr) at 125.3 ± 31.6%, and notably Cesium (Cs) at 32 ± 18.2%.

arXiv Open Access 2022
Sparse Non-Convex Optimization For Higher Moment Portfolio Management

Farshad Noravesh

One of the reasons that higher order moment portfolio optimization methods are not fully used by practitioners in investment decisions is the complexity that these higher moments create by making the optimization problem nonconvex. Many few methods and theoretical results exists in the literature, but the present paper uses the method of successive convex approximation for the mean-variance-skewness problem.

en cs.CE, q-fin.PM
arXiv Open Access 2022
An energetically consistent surface correction method for bond-based peridynamics

Jonas Ritter, Shucheta Shegufta, Paul Steinmann et al.

A novel surface correction method is proposed for bond based peridynamics which ensures energy consistency with a classical reference body for general affine deformations. This method is validated for simple geometries and then applied to a typical surface-dominated problem, namely the indentation of a surface in the shallow to moderate-depth regime.

en cs.CE
arXiv Open Access 2021
GSEIM: A General-purpose Simulator with Explicit and Implicit Methods

Mahesh B. Patil, Ruchita D. Korgaonkar, Kumar Appaiah

A new simulation package, GSEIM, for solving a set of ordinary differential equations is presented. The organisation of the program is illustrated with the help of a block diagram. Various features of GSEIM are discussed. Two ways of incorporating new elements in GSEIM, viz., as a template and as a subcircuit, are explained by taking a specific example. Simulation examples are described to bring out the capabilities of GSEIM.

en cs.CE
arXiv Open Access 2020
Kaemika app, Integrating protocols and chemical simulation

Luca Cardelli

Kaemika is an app available on the four major app stores. It provides deterministic and stochastic simulation, supporting natural chemical notation enhanced with recursive and conditional generation of chemical reaction networks. It has a liquid-handling protocol sublanguage compiled to a virtual digital microfluidic device. Chemical and microfluidic simulations can be interleaved for full experimental-cycle modeling. A novel and unambiguous representation of directed multigraphs is used to lay out chemical reaction networks in graphical form.

en cs.CE
arXiv Open Access 2020
User Manual for the SU2 EQUiPS Module: Enabling Quantification of Uncertainty in Physics Simulations

Jayant Mukhopadhaya

This document serves as the manual for using the EQUiPS (Enabling Quantification of Uncertainty in Physics Simulations) module in SU2. The EQUiPS module uses the Eigenspace Perturbation methodology to provide interval bounds on Quantities of Interest (QoIs) that capture epistemic uncertainties arising from assumptions made in RANS turbulence models. This has been implemented and tested in SU2 for a variety of benchmark turbulence cases as well as flows of aerodynamic interest.

en cs.CE, physics.flu-dyn
arXiv Open Access 2019
Modeling Fluid Mixing in Microfluidic Grids

Huong Luu, Marek Chrobak

We describe an approach for modeling fluid concentration profiles in grid-based microfluidic chips for fluid mixing. This approach provides an algorithm that predicts fluid concentrations at the chip outlets. Our algorithm significantly outperforms COMSOL finite element simulations in term of runtime while still producing results that closely approximate those of COMSOL.

en cs.CE, physics.flu-dyn
arXiv Open Access 2015
Calculation of the confidence bounds for the fraction nonconforming of normal populations of measurements in clinical laboratory medicine

Aristides T. Hatjimihail

The fraction nonconforming is a key quality measure used in statistical quality control design in clinical laboratory medicine. The confidence bounds of normal populations of measurements for the fraction nonconforming each of the lower and upper quality specification limits when both the random and the systematic error are unknown can be calculated using the noncentral t-distribution, as it is described in detail and illustrated with examples.

en cs.CE
arXiv Open Access 2014
Car-following model on two lanes and stability analysis

Yuhan Jia, Jianping Wu, Yiman Du et al.

Considering lateral influence from adjacent lane, an improved car-following model is developed in this paper. Then linear and non-linear stability analyses are carried out. The modified Korteweg-de Vries (MKdV) equation is derived with the kink-antikink soliton solution. Numerical simulations are implemented and the result shows good consistency with theoretical study.

en cs.CE
arXiv Open Access 2014
Amino Acid Interaction Network Prediction using Multi-objective Optimization

Md. Shiplu Hawlader, Saifuddin Md. Tareeq

Protein can be represented by amino acid interaction network. This network is a graph whose vertices are the proteins amino acids and whose edges are the interactions between them. This interaction network is the first step of proteins three-dimensional structure prediction. In this paper we present a multi-objective evolutionary algorithm for interaction prediction and ant colony probabilistic optimization algorithm is used to confirm the interaction.

en cs.CE, cs.NE
arXiv Open Access 2014
Research on Study Mechanical Vibrations with Data Acquisition Systems

Lenuta Suciu, Florentina Cziple, Cornelia Anghel

The paper presents a new study method of mechanic vibrations with the help of the data acquisition systems. The study of vibrations with the help of data acquisition systems allows the solving of some engineering problems connected to the measurement of some parameters which are difficult to measure having in view the improvement of the technical performances of the industrial equipment or devices

en cs.CE

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