scholarly journals Method of Determination of the Diurnal Energy Consumption of the Cadets from the Vasil Levski National Military University

2018 ◽  
Author(s):  
Pavlin Glushkov ◽  
Simeon Simeonov ◽  
Marin Georgiev
Keyword(s):  
Energy Consumption ◽  
Method Of Determination

scholarly journals A grafo-numeric method of determination of the operation power of the rotor of EsRc-1400 bucket wheel excavator using computer simulation in SolidWorks

2019 ◽  
Vol 290 ◽  
pp. 04007
Author(s):  
Florin Dumitru Popescu ◽  
Sorin Mihai Radu ◽  
Andrei Andraş ◽  
Ildiko Kertész Brînaş
Keyword(s):  
Computer Simulation ◽  
Energy Consumption ◽  
Specific Energy ◽  
Horizontal Plane ◽  
Specific Energy Consumption ◽  
Vertical Plane ◽  
Conveyor System ◽  
Method Of Determination ◽  
Loading System

The bucket wheel excavator (BWE) is a complex continuous digging machine, used to excavate material using a layout of buckets installed on a rotor (bucket wheel), and at the same time, using the conveyor system installed on its boom, transferring this material to the main conveyor. The bucket wheel is the operating equipment, and it rotates in the vertical plane and performs (with the boom) a pivoting movement in the horizontal plane and an ascendant – descendent movement in the vertical plane. The paper presents a new grafo-numeric method of determination of the operation power of the BWE rotor, using computer simulation in SolidWorks. The aim of using virtual models for the analysis of the operation of some components of the BWE is to reduce the specific energy consumption during cutting while maintaining the installed operation power of the rotor, to increase the excavation capacity and to improve the cutting – loading system.

Development of a method for multielemental determination in water by EDXRF with radioisotopic source of 238Pu.

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Camilo Fuentes Serrano ◽  
Juan Reinaldo Estevez Alvares ◽  
Alfredo Montero Alvarez ◽  
Ivan Pupo Gonzales ◽  
Zahily Herrero Fernandez ◽  
...  
Keyword(s):  
Thin Layer ◽  
Expanded Uncertainty ◽  
Considerable Decrease ◽  
X Ray ◽  
Precipitation Efficiency ◽  
Method Of Determination ◽  
Sensitivity Curves ◽  
Order Of Magnitude ◽  
Metrological Parameters

A method for determination of Cr, Fe, Co, Ni, Cu, Zn, Hg and Pb in waters by Energy Dispersive X Ray Fluorescence (EDXRF) was implemented, using a radioisotopic source of 238Pu. For previous concentration was employed a procedure including a coprecipitation step with ammonium pyrrolidinedithiocarbamate (APDC) as quelant agent, the separation of the phases by filtration, the measurement of filter by EDXRF and quantification by a thin layer absolute method. Sensitivity curves for K and L lines were obtained respectively. The sensitivity for most elements was greater by an order of magnitude in the case of measurement with a source of 238Pu instead of 109Cd, which means a considerable decrease in measurement times. The influence of the concentration in the precipitation efficiency was evaluated for each element. In all cases the recoveries are close to 100%, for this reason it can be affirmed that the method of determination of the studied elements is quantitative. Metrological parameters of the method such as trueness, precision, detection limit and uncertainty were calculated. A procedure to calculate the uncertainty of the method was elaborated; the most significant source of uncertainty for the thin layer EDXRF method is associated with the determination of instrumental sensitivities. The error associated with the determination, expressed as expanded uncertainty (in %), varied from 15.4% for low element concentrations (2.5-5 μg/L) to 5.4% for the higher concentration range (20-25 μg/L).

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