Estimation of water transit time in soils under Amazon forest cover using variations in sigma18O values.

In an attempt to estimate the soil-water transit time using the variation in 18O values, a statistical model was used. This model is based on linear regression analysis applied to the values observed for soil water and rain water. The time obtained from these correlations represents the mean time necessary for the water to run from one collecting point to the next.-from Authors

Numerical simulation of viscous three-dimensional flow over aerospace vehicles using Euler/boundary-layer zonal approach

This paper presents a viscous three-dimensional simulations coupling Euler and boundary layer codes for calculating flows over arbitrary surfaces. The governing equations are written in a general non orthogonal coordinate system. The Levy-Lees transformation generalized to three-dimensional flows is utilized. The inviscid properties are obtained from the Euler equations using the Beam and Warming implicit approximate factorization scheme. The resulting equations are discretized and approximated by a two-point fmitedifference numerical scheme. The code developed is validated and applied to the simulation of the flowfield over aerospace vehicle configurations. The results present good correlation with the available data.

Time and distance in acceleration of road commercial vehicles

The time and the distance traveled during the acceleration and the velocity retaking are parameters used for the comparison and the project of vehicles. In this paper equations for the calculation of those parameters are presented. Several criteria are presented for the shift gears. It is also verified the occurrence or not of total slip during the acceleration of the vehicle. The theoretical models were implemented in a developed computational system. Such system was applied in a Mercedes-Benz do Brazil sample vehicle, in order to facilitate comparisons between the simulate values and the experimental road tests. Copyright © 1997 Society of Automotive Engineers, Inc.

Fuel consumption of road commercial vehicles in the driving schedule

The fuel consumption is an important factor in the vehicle development due the fact that it has a direct effect on its trade aims. Besides that, it is known that the petrol is a scarce fuel. In this paper it is presented a procedure of fuel consumption calculation for a vehicle traveling in driving schedule. In such calculation it has been taken into account the operational conditions (load, pavement, climbing road, among others) and the building characteristics (map engine, transmission, frontal area, tire, among others) of road vehicles. There has also been an application of the theoretical model developed in a sample Mercedes-Benz do Brasil vehicle which has been compared with the values of experimental tests. Copyright © 1997 Society of Automotive Engineers, Inc.

Prospective analysis about the world wide strategy of commercial vehicles development

The main objective of this paper is to make a prospective analysis about the tendencies of the world wide strategies of commercial vehicles development, in relation of the current local and international scenery. It has been done a research by using the Delphi method, which consists into regulate, systematically, the presentation of questions about a specified problem to a group of specialists. In order to guarantee more representative data, it has been adopted three distinct groups: academics, OEMs managers and Tier 1 suppliers managers. The results showed that the three mentioned groups have similar opinion about the necessity of having a product development in the subsidiaries companies; also it has been pointed the necessity of having more taylor made vehicles, due to the intrinsic characteristics of this industry segment. Copyright © 2008 SAE International.

Employment of a noninvasive magnetic method for evaluation of gastrointestinal transit in rats

AC Biosusceptometry (ACB) was previously employed towards recording gastrointestinal motility. Our data show a reliable and successful evaluation of gastrointestinal transit of liquid and solid meals in rats, considering the methods scarcity and number of experiments needed to endorsement of drugs and medicinal plants. ACB permits real time and simultaneous experiments using the same animal, preserving the physiological conditions employing both meals with simplicity and accuracy. © 2012 Quini et al.; licensee BioMed Central Ltd.

A multi-agent system with a percolation approach to simulate the driving pattern of Plug-In ELectric Vehicles

A multi-agent system with a percolation approach to simulate the driving pattern of Plug-In Electric Vehicle (PEV), especially suited to simulate the PEVs behavior on any distribution systems, is presented. This tool intends to complement information about the driving patterns database on systems where that kind of information is not available. So, this paper aims to provide a framework that is able to work with any kind of technology and load generated of PEVs. The service zone is divided into several sub-zones, each subzone is considered as an independent agent identified with corresponding load level, and their relationships with the neighboring zones are represented as network probabilities. A percolation approach is used to characterize the autonomy of the battery of the PVEs to move through the city. The methodology is tested with data from a mid-size city real distribution system. The result shows the sub-area where the battery of PEVs will need to be recharge and gives the planners of distribution systems the necessary input for a medium to long term network planning in a smart grid environment. © 2012 IEEE.

Esophageal transit time assessed by magnetic methods: An in vitro feasibility study of the novel alternating current biosusceptometry with 3-axis magnetorresistor

A hybrid magnetic instrumentation to detect a magnetic field from a permanent magnet, and to detect magnetic markers and tracers using alternating current biosusceptometry (ACB) is discussed. The instrument was used to in vitro evaluation of the esophageal transit time. The sensitivity between both magnetic methods was compared, showing sensitivity for in vivo applications. © 2013 Springer-Verlag.