Studies of auroral X-ray imaging from high altitude spacecraft

Results of a study of techniques for imaging the aurora from a high altitude satellite at X-ray wavelengths are summarized. The X-ray observations allow the straightforward derivation of the primary auroral X-ray spectrum and can be made at all local times, day and night. Five candidate imaging systems are identified: X-ray telescope, multiple pinhole camera, coded aperture, rastered collimator, and imaging collimator. Examples of each are specified, subject to common weight and size limits which allow them to be intercompared. The imaging ability of each system is tested using a wide variety of sample spectra which are based on previous satellite observations. The study shows that the pinhole camera and coded aperture are both good auroral imaging systems. The two collimated detectors are significantly less sensitive. The X-ray telescope provides better image quality than the other systems in almost all cases, but a limitation to energies below about 4 keV prevents this system from providing the spectra data essential to deriving electron spectra, energy input to the atmosphere, and atmospheric densities and conductivities. The orbit selection requires a tradeoff between spatial resolution and duty cycle

Comparison of Grain Refinement in Selected Materials Subjected to Hydrostatic Extrusion

The subject of this study was to examine and compare the impact of intense hydrostatic extrusion on grain refinement in three different alloys: duplex stainless steel, commercially used aluminum alloy (6060) and Ag-Cu12 alloy. As a result of the process grain sizes from 370 nm to 90 nm were obtained in aluminum and duplex steel. To analyze the of hydrostatic on mechanical properties tensile tests were also carried out. The highest grain refinement (70 nm) and yield strength increase (over 300%) was observed in duplex steel af-ter hydrostatic extrusion. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3560

Linear pressing of coconut copra meal (Cocos nucifera L.) under different temperatures

ArticlePressing of vegetable oils plays an important role in the food processing. This study described the compression behaviour of copra (Cocos nucifera L.) using the universal compression testing machine and vessel diameter of 60 mm with a plunger. The influence of heat treatment on oil recovery efficiency and specific mechanical energy were determined. Compression tests at the rate of 1 mm s −1 under five different temperatures 20, 40, 60, 80 and 100 °C were performed. The measuring range of force was between 0 kN and 50 kN. It has been found that the amount of obtained oil increased and specific mechanical energy decreased with increased temperature. Measured data were analysed by computer software Mathcad 14 (MathCAD 14, PTC Software, Needham, MA, USA). Mathematical model describing the mechanical behaviour of bulk copra under compression loading was represented

Extraction of oil from rapeseed using duo screw press

ArticleThis study was focused on the analysis of optimize the pressing process of rapeseeds ( B rassica napus L.) using screw press. For pressing of oil a screw press Farmer 20 – duo (Farmer 20, Farmet a.s., Ceska Skalice, Czech republic) was used. The screw rotation speed 10, 20, 30, 40, 55 and 65 rpm was used. Oil recovery efficiency and specific mechanical energy were decreased when the seed material troughput was increased. It has been found that the optimal operation point for screw press Farmer 20 – duo was at 20 kg h - 1 rapeseed throughput. The specific mechanical energy at the optimal operation point was 0.61 kWh kg oil - 1 Maximum oil recovery efficiency 82.6% was found at the lowest screw speed

Mathematical description of loading curves and deformation energy of bulk oil palm kernels

ArticleThe study aimed at describing the experimental and theoretical relationships between t he force and deformation curves as well as the deformation energy of bulk oil palm kernels under compression loading. V essel diameters of 60, 80 and 100 mm with initial pressing heights of the bulk kernels measured at 40, 60 and 80 mm were examined by appl ying a maximum compressive force of 200 kN and a speed of 5 mm min - 1 . For the theoretical description of the force and deformation curves, the tangent curve mathematical model was applied using the MathCAD 14 software where the force coefficient of mechani cal behaviour, A (kN), the deformation coefficient of mechanical behaviour, B (mm - 1 ) and the fitting curve function exponent, n ( - ) were determined respectively. The determined coefficients in addition to the maximum deformation values obtained from the co mpression test were used for the estimation of the theoretical or analytical deformation energy. The determined regression models expressing the deformation, numerical energy and theoretical energy as well as the tangent model coefficients A and B dependen t on the vessel diameter and pressing height were statistically significant ( P < 0.05) or ( F - ratio > F - critical) . Improving the mechanical pressing of oil extraction for both domestic and industrial applications still remain a concer n of researchers and en gineers

Utilization of image analysis for description of drying characteristics of selected tropical fruits

ArticleThis study is focused on the utilization of image analysis for description of dimensions, and colours changes of fruits during drying process. Selected tropical fruits such are banana (Musa acuminata), mango (Magnifera indica) and pineapple (Ananas comosus) originally from North Sumatera in Indonesia were used in this experiment. Sliced pieces of the fruits were dried in experimental oven under temperature 90 °C for period of time 180 min and image of fruits samples were recorded by digital camera with HD resolution continuously throughout drying process. With aid of image analysis using Image J software and regarding to drying characteristics the colours and dimensions of the samples were analysed

Mechanical behaviour of Sugar palm (Arenga pinnata) fibres

ArticleThe tensile strength of Sugar palm ( Arenga pinnata ) fibres was examined. Fibre samples were prepared and tested up to the point of rupture with a deformation rate of 0.05 min - 1 . The tensile device (Labortech, MPTest 5.050, Czech Republic) were used to determine the tensile force. The aim of the paper was to describe a mechanical behaviour of Sugar palm ( Arenga pinnata ) fibres. Measured values can be used as a basis for further research on the application of Sugar palm fibres

Theoretical analysis of force, pressure and energy distributions of bulk oil palm kernels along the screwline of a mechanical screw press FL 200

ArticleThe present study is a follow-up of the previously published study on the mathematical description of loading curves and deformation energy of bulk oil palm kernels under compression loading, aimed at determining theoretically the amounts of force, pressure and energy along the screw lamella positions of the screw press FL 200 by applying the tangent curve mathematical model and the screwline geometry parameters (screw shaft diameter, screw inner and outer diameters, screw pitch diameter and the screw thickness). The fitting curve value of the tangent mathematical model was further examined at = 2 and = 3 by identifying the force, deformation, stress and compression coefficients at varying vessel diameters and initial pressing heights of the bulk oil palm kernels. Based on the results of the stepwise regression analysis, the amounts of the theoretical deformation energy in linear pressing as well as the theoretical force , pressure and energy of the screw press FL 200 were statistically significant (P-value significance F) in relation to the predictors ( , , and ). The coefficient of determination (R2 ) values between 61 and 86 % were observed for the determined regression models indicating that the responses , , and can accurately be predicted by the corresponding predictors. The normal probability plots of the responses approximately showed a normal distribution

3D image analysis of the shapes and dimensions of several tropical fruits

ArticleT hree dimension virtual models of Avocado ( Persea americana ) , Salak ( Salacca zalacca ) , Dragon fruit ( Hylocereus undatus ) , Mango ( Mangifera indica ) , Coconut ( Cocos nucifera ) using 3D scanner Intel RealSense were determined. C alculated models based on arithmetic and geometric diameter were also determined. From statistically analysis implies that virtual models on significance level 0 .05 are significantly different with calculated values based on arithmetic or geometric diameter