Search results for "amber"

Evaluation of 6 biometers based on different optical technologies

2021

This study shows that optical biometers based on different technologies provide repeatable measurements for different ocular parameters and, when compared, statistically significant differences between them were found when measuring most parameters.

Chilamnestocoris mixtus gen. et spec. nov., the first burrower bug (Hemiptera: Pentatomoidea: Cydnidae) in Upper Cretaceous Burmese amber

2018

A chamber to test the response of radon detectors to changing environmental conditions.

2011

Radon risk assessment is carried out with accurate measurements with active or passive instrumentation. All radon detectors must be calibrated and tested using a radon chamber containing a known concentration of radon produced by specific sources of 226Ra. Some of the chambers can also be used to test the response of detectors as a function of environmental conditions. In this case, it can be inferred a calibration curve with respect to changing of the parameter considered. For this aim, a new chamber radon was designed and realized to perform both calibration of instruments and to study the detector response in a large range of variation of the environmental parameters (pressure, 700 - 110…

Influence of compliance for an elastokinematic model of a proposed rear suspension

2014

The research is carried out to improve passenger’s comfort to increase the vehicles stability in dynamic conditions. The literature available in the automotive engineering considers different topics for studying suspensions. An example represents mechanisms structure and analysis (synthesis, kinematics, and dynamics) under various operating conditions. These aspects have been approached before analytically, numerical. The current paper studies the influence of the lateral force on the contact patch of the wheel and the corresponding variations of vehicle stability parameters, such as camber angle and wheel rear track. The study is performed for a newer innovative rear suspensions mechanism …

Optimization of the characteristic angles of both front and rear McPherson suspensions on a circular track using multi-body numerical simulation

2009

The research reported in this paper aims to simulate the road-holding of a virtual vehicle using multi-body simulation to estimate both the contact forces between the tyre and ground and the roll motion when cornering. Furthermore, the effect of the characteristic angles on the variation in the forces of the tyre in contact with the ground is studied to determine optimal values for these angles. Emphasis is placed on an average-class vehicle, of which both the external dimensions and mass are chosen appropriately, with a McPherson suspension mounted on both the front and the rear. The characteristic values of the camber and toe-in angles, in both the front and the rear, are optimized for m…

Tissue gradients of energy metabolites mirror oxygen tension gradients in a rat mammary carcinoma model

2001

Abstract Purpose: It has been shown that oxygen gradients exist in R3230AC tumors grown in window chambers. The fascial surface is better oxygenated than the tumor surface. The purpose of the present study was to determine whether gradients exist for energy metabolites and other end points related to oxygen transport. Methods and Materials: Imaging bioluminescence was used to measure ATP, glucose, and lactate in cryosections of R3230AC tumors. Mean vessel density and hypoxic tissue fraction were assessed using immunohistochemistry. Tumor redox ratio was assessed by redox ratio scanning. Results: Lactate content and hypoxic fraction increased, whereas ATP, glucose, redox ratio, and vessel de…

A dosimetric study of Leipzig applicators.

2005

Purpose: To obtain the absolute dose-rate distribution in liquid water for all six cup-shaped Leipzig applicators by means of an experimentally validated Monte Carlo (MC) code. These six applicators were used in high-dose-rate (HDR) afterloaders with the “classic” and v2 192Ir sources. The applicators have an inner diameter of 1, 2, and 3 cm, with the source traveling parallel or perpendicular to the contact surface. Methods and materials: The MC GEANT4 code was used to obtain the dose-rate distribution in liquid water for the six applicators and the two HDR source models. To normalize the applicator output factors, a MC simulation for the “classic” and v2 sources in air was performed to es…

CO2 uptake of Opuntia ficus-indica (L.) Mill. whole trees and single cladodes, in relation to plant water status and cladode age

2013

Most of net photosynthesis determinations in Opuntia ficus-indica come from measurements on individual cladodes. However, they have limitations when used to scale up to whole canopy gas exchange, because a large variability of carbon assimilation may occur within the canopy, due to, among others, differences in cladode age and intercepted radiation or individual cladode response to abiotic stresses. The aim of this work was to evaluate the application of open gas exchange chambers, simultaneously applied around the whole canopy, to measure net CO 2 uptake, continuously over a 24 h period, in single Opuntia ficus-indica (L.) Mill. potted trees and in relation with their water status. Net CO2…

Una ética de la excelencia: Cayetana de la Cerda y la circulación de Madame de Lambert en España

2015

En este artículo se sintetizan las líneas maestras del pensamiento de Anne-Thérèse Marguenat, marquesa de Lambert (1647-1733) y se profundiza en el eco que su obra tuvo en España, aclarando algunos episodios poco conocidos y arrojando luz sobre el contexto en el que se realizó y publicó finalmente la versión castellana de sus ensayos y sobre la personalidad intelectual y circunstancias sociales de su traductora, Cayetana de la Cerda y Vera, condesa de Lalaing (1755-1798). Se pretende así analizar las prácticas de transferencia y mediación cultural, interrogándonos sobre los significados con que su pensamiento y su figura pudieron ser investidos por parte de los sujetos implicados en su lect…

Optimization of the Ussing chamber setup with excised rat intestinal segments for dissolution/permeation experiments of poorly soluble drugs.

2016

AbstractContext: Prediction of the in vivo absorption of poorly soluble drugs may require simultaneous dissolution/permeation experiments. In vivo predictive media have been modified for permeation experiments with Caco-2 cells, but not for excised rat intestinal segments.Objective: The present study aimed at improving the setup of dissolution/permeation experiments with excised rat intestinal segments by assessing suitable donor and receiver media.Methods: The regional compatibility of rat intestine in Ussing chambers with modified Fasted and Fed State Simulated Intestinal Fluids (Fa/FeSSIFmod) as donor media was evaluated via several parameters that reflect the viability of the excised in…