Performance of a Brayton power system with a space type radiator

Test results of an experimental investigation to measure Brayton engine performance while operating at the sink temperatures of a typical low earth orbit are presented. The results indicate that the radiator area was slightly oversized. The steady state and transient responses of the power system to the sink temperatures in orbit were measured. During the orbital operation, the engine did not reach the steady state operation of either sun or shade conditions. The alternator power variation during orbit was + or - 4 percent from its mean value of 9.3 kilowatts

Women's Political Participation and Economic Empowerment in Post-conflict Countries: Lessons From the Great Lakes Region in Africa

This report represents a synthesis of the key findings and recommendations of a regional research project on women's political participation and economic empowerment in countries emerging from conflicts in the Great Lakes region of Africa. The research focuses on four case studies and examines the nature and quality of women's political participation in the four countries to establish whether women's increased representation in decision making at the national and local governance level has translated into the adoption of gender equality policies and enhancement of women's socio-economic status at all levels of society. The research further analyses the economic dimension of women's political participation by linking women's economic empowerment and their representation in the political arena

Preliminary thermal performance analysis of the solar Brayton heat receiver

Thermal performance analysis of solar Brayton heat receiver in transferring heat to working gas of Brayton engin

SEASON PREVIEW: GS Men\u27s Soccer Ready To Attack The Sun Belt In 2019

SEASON PREVIEW: GS Men\u27s Soccer Ready To Attack The Sun Belt In 201

Gear bearing drive

A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs

Profitability of the Mediterranean and NE Atlantic new target sea cucumber species: some repercussions for their fisheries management

The term profitability can be understood as the ratio in percentage between fresh weight of animals and the dry weight of the obtained beche-de-mer depending on the body wall thickness of sea cucumbers and water content. Specimens decrease their weight and length considerably, when they are processed. However, scarce information about profitability of commercial sea cucumber from Mediterranean and NE Atlantic has been published until now. In this study, we focused on Holothuria tubulosa, Holothuria polii, Holothuria mammata and Holothuria arguinensis. For most of the species considered, a good lineal regression was found between eviscerated length (EL) vs eviscerated weight (EW), and EW vs dried weight (DW)however, H. arguinensis showed a high dispersal of data and low regression coefficients. The highest profitability (20.57 % +/- 4.40) was registered on H. arguinensis and the second one (15.36 % +/- 2.68) on H. polii. H. mammata and H. tubulosa showed lower profitability (11.95 % +/- 0.54 and 10.75 % +/- 0.55, respectively). Significant differences were found between profitability values of the studied species. Some implications for fisheries management were deduced from the relationships between profitability vs EW.CUMARSUR project - Fundacao para a Ciencia e a Tecnologia [PTDC/MAR-BIO/5948/2014]HOLREMAR project - Sayanes Mar S.L.FCTPortuguese Foundation for Science and Technology [IF/00998/2014, CCMAR/BI/0007/2015

Improved boundary layer heat transfer calculations near a stagnation point

A thermal design of a solar receiver has been developed for the solutions of problems involving phase-change thermal energy storage and natural convection loss. Two dimensional axisymmetrical solidification and melting of materials contained between two concentric cylinders of finite length has been studied for thermal energy storage analysis. For calculation of free convection loss inside receiver cavity, two dimensional axisymmetrical, laminar, transient free convection including radiation effects has been studied using integral/finite difference method. Finite difference equations are derived for the above analysis subject to constant or variable material properties, initial conditions, and boundary conditions. The validity of the analyses has been substantiated by comparing results of the present general method with available analytic solutions or numerical results reported in the literature. Both explicit and implicit schemes are tested in phase change analysis with different number of nodes ranging from 4 to 18. The above numerical methods have been applied to the existing solar receiver analyzing computer code as additional subroutines. The results were computed for one of the proposed Brayton cycle solar receiver models running under the actual environmental conditions. Effect of thermal energy storage on the thermal behavior of the receiver has been estimated. Due to the thermal energy storage, about 65% reduction on working gas outlet temperature fluctuation has been obtained; however, maximum temperature of thermal energy storage containment has been increased about 18%. Also, effect of natural convection inside a receiver cavity on the receiver heat transfer has been analyzed. The finding indicated that thermal stratification occurs during the sun time resulting in higher receiver temperatures at the outlet section of the gas tube, and lower temperatures at the inlet section of the gas tube when compared with the results with no natural convection. Due to heat supply from the air during the shade time, minimum temperature has been increased, while maximum temperature has been reduced due to convection loss to air. Consequently, cyclic temperature fluctuation has been reduced 29% for working gas and 16% for thermal energy storage containment. On the other hand, despite the presence of the natural convection the time-averaged temperatures for receiver components were found to be similar for two cases with/without natural convection (maximum difference was 1.8%)

Reading Pictures: Sixteenth-Century European Illustrated Books

Document to accompany the exhibition Reading Pictures: Sixteenth-Century European Illustrated Books. The exhibit surveyed European book illustration during the sixteenth century. Examples all come from Penn’s rich collections of sixteenth-century European printing. Their wide variety of styles and subjects illuminate what early modern book illustrators provided readers in an environment visually far less rich than the one we take for granted. Religion, labor, science, warfare, costume, medicine, portraits, exotic places, and more — all these topics found their way not only into words but also into pictures