Discerning combining ability loci for divergent environments using chromosome segment substitution lines (CSSLs) in pearl millet

Pearl millet is an important crop for arid and semi-arid regions of the world. Genomic regions associated with combining ability for yield-related traits under irrigated and drought conditions are useful in heterosis breeding programs. Chromosome segment substitution lines (CSSLs) are excellent genetic resources for precise QTL mapping and identifying naturally occurring favorable alleles. In the present study, testcross hybrid populations of 85 CSSLs were evaluated for 15 grain and stover yield-related traits for summer and wet seasons under irrigated control (CN) and moisture stress (MS) conditions. General combining ability (GCA) and specific combining ability (SCA) effects of all these traits were estimated and significant marker loci linked to GCA and SCA of the traits were identified. Heritability of the traits ranged from 53–94% in CN and 63–94% in MS. A total of 40 significant GCA loci and 36 significant SCA loci were identified for 14 different traits. Five QTLs (flowering time, panicle number and panicle yield linked to Xpsmp716 on LG4, flowering time and grain number per panicle with Xpsmp2076 on LG4) simultaneously controlled both GCA and SCA, demonstrating their unique genetic basis and usefulness for hybrid breeding programs. This study for the first time demonstrated the potential of a set of CSSLs for trait mapping in pearl millet. The novel combining ability loci linked with GCA and SCA values of the traits identified in this study may be useful in pearl millet hybrid and population improvement programs using marker-assisted selection (MAS)

Some experiments on buckling of electroformed nickel shell specimens

A controlled end-displacement type test rig was developed to study the buckling of electroformed thin circular cylindrical nickel shell specimens; to measure the stress distribution around the shell, a straingage type of load cell was devised. Experimental values of buckling load approximated 65% of the classical values, while the typical load variation around the circumference of the shell was found to be about 15%

Large deflection vibration of angle ply laminated plates

Large deflection vibration of unsymmetric angle ply laminated rectangular plates are studied. Two different out of plane boundary conditions considered are (a) all the edges clamped, and (b) all the edges simply supported. The dynamic analogues of Von Karman's large deflection equations for laminated plates are used. Solutions are obtained for two in-plane boundary conditions. Non-linear frequency is obtained as a function of lamination parameter, material constants, aspect ratio, linear frequency and amplitude of vibration. Two mode analysis also is presented wherein the modal equations are solved by a perturbation technique. Non-linear frequency to linear frequency ratio amplitude curves are presented for various cases

Electroforming of thin shells (Thin Ni shell electroforming for13; applications in structural tests, discussing plating bath composition, Al and wax mandrels preparation)

An electroforming process developed for obtaining nickel shells of acceptable quality for structural tests is described. The discussion covers the composition of the plating bath, the preparation of aluminum mandrels (using silver as the releasing agent), the plating of aluminum mandrels, the removal of shells from aluminum mandrels, and the preparation of wax mandrels. The shell specimens obtained by these techniques have identical inner diameters, similar mechanical properties, and are free from residual or internal stresses. The variation of the shell thickness does not exceed 3%. The samples obtained were 10 in. long, 0.004 in. thick, and had an inner diameter of 5.274 inches

Interaction of CO2 with subsurface resources

B.D. Field, C S. Bachu, M. Basava-Reddi, M.A. Bunch, R. Funnell, S. Holloway, R. Richardso