A modern, effective, two-phase heat transfer device, a loop heat pipe (LHP), was studied analytically and experimentally. A 1-D steady-state model was developed based on energy balance equations. The mathematical modeling procedures of each component are explained in detail, including a model of the secondary wick in the evaporator. Other models neglect the existence of the secondary wick because the detailed designs of the secondary wick are often proprietary. Three sets of experiments were performed at different elevations. Results of experimental data are compared with 1-D steady-state model predictions. The comparisons show that the model predictions of steady state operating temperatures for both zero elevation and adverse elevation are within 2 percent. It has been clearly demonstrated that the 1-D steady-state model is a useful tool for future LHP study.

that neutron imaging (both real time neutron radioscopy and single exposure neutron radiography) is an effective experimental tool for the study of LHPs. Specifically, neutron imaging has helped to identify and correct a cooling water distribution problem in the condenser, and has enabled visualization of two-phase flow (liquid and vapor) in various components of the LHP. In addition, partial wick dry-out, a phenomenon of great importance in the effective operation of LHPs, has been identified with neutron imaging. It is anticipated that neutron radioscopy and radiography will greatly contribute to our understanding of LHP operation, and will lead to improvement of LHP modeling and design.

Sixteen white open pollinated populations of maize were evaluated in 1995 and 1996 season at Sids Agric. Res. Station of the ARC, Egypt under 5 soil moisture regimes (4 stressed and one non-stressed environments). The objectives were to: 1-identify maize traits strongly associated with yield under water stress to be used as selection criteria for reliable screening drought tolerant genotypes; 2-to estimate the heritability under different soil moisture regimes and 3-to compare these moisture regimes as evaluation environments based on expected genetic advance from direct and indirect selection.Results suggested that the strogest association with absolute yield under drought stress environments was negative for days to 50% silking, anthesis to silking interval (ASI), leaf/air temperature and barren stalks (%). Moreover, such association was positive for ears/plant and kernels/row. Thus, these triats were considered as useful selection criteria for screening maize genotypes for their drought tolerance if phenotypic correlation reflects positive relationships at the genetic level.Heritability estimates under drought stress environments for grain yield, number of kernels/row, leaf/air temperature and leaf rolling were lower but those for ASI, ears/plant and stay green traits were higher than those estimates under non-stressed environment.The prediction gain from direct selection in either stress or non-stress environments was greater than that from indirect selection in either stress or non-stress environments for all studied traits (ASI, leaf rolling, leaf temperature, stay green, ears/plant and grain yield). Maximum genetic advance from direct selection for grain yield was obtained from the stressed environments at flowering stage.

Two field experiments were carried out at Gemiza (ARS), during 2012, 2013. The aim of the study was to evaluate the performance of S.C.167 and T.W.C. 253 maize under the use of different rates of NPK. Fertilizer were tested cross (Cs) , soil application (SA) and foliar one (FA). All the agriculture treatments were used as usual. A split split plot design was used. five traits were studied. Such traits were distributed at ear length, ear diameter, ear height, cob. Weight, and shilling percentage. The obtained results could be summarized as follows :-Crosses, soil application and foliar application of NPK signifcantly affected most studied traites except ear height, cob. weight, and shilling percentage .-Significancey was completely absent as respect to first and second order interaction with all studied trait but the superior vlues were produced from combination (T.W.C. 253 × 80% NPK (S.A.)), (T.W.C. 253 × 80% NPK (F.A.)) and (80% NPK (S.A.

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