Simple calculation methods for the lighting of passages and tunnels

1975 ◽  
Vol 7 (1) ◽  
pp. 30-34 ◽  
Author(s):  
H.D. Einhorn
2017 ◽  
Vol 3 (2) ◽  
pp. 13-23
Author(s):  
Paulo A. G. Piloto ◽  
◽  
Mohamed S. Khetata ◽  
Ana B. R. Gavilán ◽  
◽  
...  

2020 ◽  
Vol 5 (1) ◽  
pp. 10-16
Author(s):  
Larissa L. L. Ferreira ◽  
Paulo A. G. Piloto ◽  
Giovanni Bratti

2015 ◽  
Vol 1120-1121 ◽  
pp. 1435-1440
Author(s):  
Dániel Koncz-Horváth ◽  
Zoltán Gácsi

In the general practice of ED-XRF measurements, the values of elemental concentrations are derived from complicated calculation methods. Hereby a simple mathematical formula is suggested, which provides an easy way to prepare standard samples. On the other hand, the simulation of spectral lines may also be a helpful tool for the calibration process. In this study, measured and simulated data were used for the quantitative analysis of ternary Au-Ag-Cu alloys. To determine the calibration points, the peak intensity ratio method was applied and the calibration curves were fitted. This work presents the results of a twofold investigation aimed at: a) finding a suitable computational tool to optimise the parameters of the underlying equations and b) testing the reliability of the simulated data to determine the concentrations of multi-element standard samples. Based on comparisons of calculated concentrations it can be stated that a simple calculation method with simulated data provides an easy tool to define calibration standards. It is also demonstrated that the parameters of the linear plots can be optimised to yield improved results.


2020 ◽  
Vol 38 (2) ◽  
pp. 212-231
Author(s):  
Paulo AG Piloto ◽  
Carlos Balsa ◽  
Lucas MC Santos ◽  
Érica FA Kimura

The fire resistance of composite slabs with steel decking, in Europe, is usually defined using simple calculation models provided by the Eurocode EN 1994-1-2. For assessing the methodology of these simple calculation methods, a new advanced calculation method is presented, using the software ANSYS. The numerical model is first validated with experimental data reported on bibliography and then a parametric analysis is conducted to better understand the effect of the load level on the composite structure under fire. The validation of the simulations consisted of three different models: the first model considers perfect contact between the steel deck and the concrete topping, and the two following models consider the existence of an air gap between these materials, acting as a thermal resistance on the temperature field through the thickness of the slab. The numerical results show good approximation to the experimental results, mainly when using the non-perfect contact model, reaching 3.88% and 16.91% of difference with respect to the insulation and load-bearing criteria, respectively. Based on the validation models, a parametric study is presented, modifying the load level from 10% up to 75%. New simple calculation models are presented to define the fire resistance of composite slabs, considering the load level, and the debonding effect between the concrete and the steel deck.


2017 ◽  
Vol 3 (3) ◽  
pp. 13-23
Author(s):  
Paulo A. G. Piloto ◽  
◽  
Mohamed S. Khetata ◽  
Ana B. R. Gavilán ◽  
◽  
...  

1985 ◽  
Vol 107 (4) ◽  
pp. 872-876 ◽  
Author(s):  
R. A. Huntington

Performance calculations for centrifugal compressors have been based on polytropic analysis for many years. The basic polytropic equation, in which head is found from gas pressure, temperature, and compressibility factor at the end points of compression, is applied by virtually all engineers involved with turbomachinery design, selection, or operation. The problems and errors associated with this simple calculation method when applied to nonideal gases have long been recognized. Schultz [1] proposed a correction factor to the head equation to compensate for the errors. This “polytropic head factor” correction is required by the ASME Power Test Code 10 [2] for the evaluation of compressor performance. Recently, the accuracy of even the corrected head equation has been questioned for the compression of gases to high pressures and an alternative calculation method has been proposed by Mallen and Saville [3]. Although differences were found between their method and the Schultz method of up to three percent, they did not show which method was more accurate. This paper evaluates the accuracy of these previous calculation methods and shows that both have errors for some compression calculations. In addition, a new polytropic calculation method is described and is shown to be substantially more accurate than the methods of both [1] and [3], thus allowing more precise evaluations of compressor performance.


2015 ◽  
pp. 147-160 ◽  
Author(s):  
S. Bobylev ◽  
N. Zubarevich ◽  
S. Solovyeva

The article emphasizes the fact that traditional socio-economic indicators do not reflect the challenges of sustainable development adequately, and this is particularly true for the widely-used GDP indicator. In this connection the elaboration of sustainable development indicators is needed, taking into account economic, social and environmental factors. For Russia, adaptation and use of concepts and basic principles of calculation methods for adjusted net savings index (World Bank) and human development index (UNDP) as integral indicators can be promising. The authors have developed the sustainable development index for Russia, which aggregates and allows taking into account balanced economic, social and environmental indicators.


Sign in / Sign up

Export Citation Format

Share Document