Gamma ray spectrometry of rocks from a volcanic sequence penetrated by the SG-1 borehole and the radiogenic contribution to the total heat flow

2002 ◽  
Vol 4 (3) ◽  
pp. 225-231
Author(s):  
Ch. S. Aliev ◽  
T. A. Zolotovitskaya ◽  
T. A. Ismailzade
Keyword(s):  
Heat Flow ◽  
Gamma Ray ◽  
Total Heat ◽  
Gamma Ray Spectrometry ◽  
Total Heat Flow ◽  
Volcanic Sequence

Simulation and Diagnostics of the External and Internal Circulation Flows of Solids in a Biomass Fired CFB Boiler

2004 ◽  
Author(s):  
Daniel Ha¨ggsta˚hl ◽  
Catrin Bartusch ◽  
Erik Dahlquist ◽  
Shilie Weng
Keyword(s):  
Heat Flow ◽  
Circulating Fluidized Bed ◽  
Internal Heat ◽  
Circulation Model ◽  
Internal Flow ◽  
Total Heat ◽  
Heat Output ◽  
Circulation Flow ◽  
Total Heat Flow ◽  
Cfb Boiler

Ash related operational problems are very common in biomass fired boilers. Biomass naturally contains both sodium chloride and potassium chloride and theses compounds lower the melting temperature of the ash which may cause large operational problems with agglomeration and defluidization in Circulating Fluidized Bed (CFB) boilers. The number of biomass fired CFB-boilers for combined heat and power (CHP) production in the Scandinavian market is growing due to their good combustion efficiency, fuel flexibility and low emissions. The power companies are asking for a method to calculate the internal and external circulation flows of solids in the boiler and an accurate diagnostic method to detect initial agglomeration in order to be able to prevent the problem of defluidization that leads to large costs and loss of revenue when the boiler has to be shut down for cleaning. Two heat and mass balance based models have been developed in order to calculate the fuel flow and the internal and external solids circulation flows in a CFB boiler with internal heat exchangers (INTREX). The solids circulation model is divided into three parts: cyclone, combustion and INTREX chambers. Measurements used in the calculation are from commissioning tests on CFB-boiler 5 at Ma¨larEnergi in Va¨stera˚s, Sweden. The boiler was manufactured by Foster Wheeler OY in Finland and has a thermal heat output of 157 MW. The external solids flow at 100% load, with and without air humidification, is 215 kg/s and the internal solids circulation is 93 kg/s. The external solids circulation flow at 60% load is 30 kg/s and the internal solids circulation flow is 486 kg/s. At 60% load, there is no data available for validation, which means that this is more an estimate then a calculation. The calculated internal flow of solids is very sensitive to changes in the total heat flow in the INTREX chamber caused by agglomeration or combustion, whereas the external solids flow is not affected. Hence initial agglomeration and combustion can be detected. A simulated agglomeration in the INTREX chambers by decreasing the total heat flow by 1%, led to a decrease in the internal solids circulation flow by 11%. A simulation of combustion in the INTREX chamber of 0.5 kg/s of fuel entering the chamber corresponds to an increase in the total heat flow of 22% and a decrease in the calculated internal mass flow of 16%. The potential for using this method of diagnostics for detecting initial agglomeration is very promising.

EFFICIENCY OF SOLAR PROTECTION OF THE MOBILE AGRICULTURAL MACHINE CAB

2020 ◽  
Author(s):  
V.V. Maslensky ◽  
◽  
Y.I. Bulygin
Keyword(s):  
Heat Flow ◽  
Solar Radiation ◽  
Sun Protection ◽  
Total Heat ◽  
Total Heat Flow ◽  
Agricultural Machine ◽  
Heat Protection ◽  
Low Efficiency ◽  
Working Day

The article checks the effectiveness of translucent enclosing structures of the tractor cab in reducing solar radiation. For this purpose, the value of the total heat flow entering the interior during the entire working day was determined, which was later compared with the hygienic standards. The result demonstrated an average low efficiency of the tractor cab sun protection. In this regard, the use of more effective shading elements and the use of glass with increased light and heat protection properties in light openings is proposed.

Ratio of Radial to Total Heat Flow in Circular Rod

1963 ◽  
Vol 85 (3) ◽  
pp. 285-286 ◽  
Author(s):  
Y. T. Tsui ◽  
F. K. Tsou
Keyword(s):  
Heat Flow ◽  
Total Heat ◽  
Total Heat Flow

Deep Drill 1972. Heat Flow and Heat Production in Bermuda

1974 ◽  
Vol 11 (6) ◽  
pp. 809-818 ◽  
Author(s):  
R. D. Hyndman ◽  
G. K. Muecke ◽  
F. Aumento
Keyword(s):  
Heat Flux ◽  
Heat Flow ◽  
Heat Production ◽  
Land Surface ◽  
Gamma Ray ◽  
Gamma Ray Spectrometry ◽  
Geothermal Heat ◽  
Sea Floor ◽  
Average Value ◽  
The Mean

The geothermal heat flux determined in a borehole on Bermuda is 1.36 μcal/cm2 s (57 mW/m2). The value is corrected for the topographic effect of the Bermuda sea-mount and the difference between sea floor and land surface temperatures. Radioactive heat production in the borehole core determined by gamma-ray spectrometry has an average value of 1.45 × 10−13 cal/cm3 s (6.11 × 10−7 W/m3). Of the altered tholeiite flows and intrusive lamprophyric sheets which make up the section to 800 m, the sheets have 10 times the heat production of the flows. If the heat production attributable to the Bermuda seamount is subtracted from the measured heat flux a value of 1.26 μcal/cm2 s (53 mW/m2) is obtained which is in good agreement with the mean of surrounding sea floor measurements and with the mean for Cretaceous ocean floor. The low heat flow and the small amount of subsidence substantiates the radioactive dating data which indicates the present seamount structure was produced about 33 m.y. ago by intrusion and uplift of a much older structure.

Gamma-Ray Spectrometric Analysis of Some Trace Elements in the Human Articular Disc of the Mandible

1963 ◽  
Vol 03 (02) ◽  
pp. 175-182 ◽  
Author(s):  
Bo Bergman ◽  
Rune Söremark
Keyword(s):  
Trace Elements ◽  
Neutron Activation ◽  
Quantitative Data ◽  
Thermal Neutron Flux ◽  
Gamma Ray ◽  
Dry Weight ◽  
Gamma Ray Spectrometry ◽  
Spectrometric Analysis ◽  
Articular Disc ◽  
Group Separation

SummaryBy means of neutron activation and gamma-ray spectrometry the concentrations in the human mandibular articular disc of the following elements have been determined: Na, Mn, Cu, Zn, Rb, Sr, Cd, W, and Au. The discs were obtained at necropsy from seven men and nine women, ranging in age from 56 to 71 years.The activation was carried out in a thermal neutron flux of about 1.7 XlO12 neutrons × cm−2 × sec.−1 for about 20 hours. A chemical group separationwas performed before the gamma-ray spectrometry. Quantitative data based on the dry weight of the cartilage samples were obtained by comparing the photo-peak area of the identified elements with those of appropriate standards.

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