Experimental Analysis OF Heat Transfer and Pressure Drop for Tube-in-fin Heat Exchangers Using Ice Slurry in HVAC System

AbstractIce slurries can be used both for cold storage in place of chilled water or ice and as a secondary refrigerant since, up to certain concentrations, they can be pumped directly through distribution pipe works and heat exchangers. For ice slurries to become more widely accepted, however, more engineering information is required on fluid flow and heat transfer characteristics. This paper reports on the results of experimental investigations of heat transfer and pressure drop of 14 % ice fraction, 16% ethylene glycol, and 70% water by volume flowing in a tube-fin exchanger. And the airflow rate is varied from between 1 m/s to 3 m/s. In this flows range, due the ice fractions caused around a 5% in the pressure drop. The overall heat transfer capacity of the heat exchanger was found to increase by more than 26% with melting ice slurry flow compared to chilled water flow. In a practical application, for a given thermal load this would lead to between 70% and 80% reduction in flow rate and pressure drop compared to chilled water cooling systems.Keywords: Heat transfer, Pressure drop, Ice slurr

Mapping the d1 and d2 dwarfing genes and the purple foliage color locus P in pearl millet

The d1 and d2 dwarfing genes and the P purple foliage color gene were placed on the restriction fragment length polymorphism (RFLP)-based molecular marker linkage map of pearl millet [Pennisetum glaucum (L.) R. Br.] using a mapping population based on a cross of inbred lines IP 18293 (D1/D1, d2/d2, P/P) and Tift 238D1 (d1/d1 D2/D2 p/p). A skeleton genetic linkage map of 562 cM (Haldane function) was constructed using 33 RFLP markers and these three morphological markers. The D1/d1 plant height locus mapped to pearl millet linkage group 1, while the D2/d2 plant height locus and the P/p foliage color locus mapped to pearl millet linkage group 4. Loose genetic linkage was observed between the D2/d2 and P/p loci, with 42% repulsion-phase recombination corresponding to 92 cM (Haldane). This loose linkage of morphological marker loci detected on pearl millet LG4 can likely find use in applied pearl millet breeding programs, as host plant resistances to both downy mildew and rust have previously been identified in this genomic region. Such exploitation of these morphological markers in an applied disease resistance breeding program would require development of appropriate genetic stocks, but the relatively loose genetic linkage between d2 and P suggests that this should not be difficult

Methodological Advancement in Molecular Markers to Delimit the Gene(s) for Crop Improvement

Molecular markers, in recent years, have accelerated plant breeding methods significantly with an objective of crop improvement. At present a variety of molecular markers are available and the choice of using a particular type of marker depends on the user. With the advances in the area of genomics, new type and gene-derived markers as well as novel approaches such as genetical genomics, linkage disequilibrium (LD)- based association mapping, etc. have been developed for identification of “perfect” markers for their use in breeding practices. The present article provides an overview on presently available but main type of molecular markers and their use in trait mapping, map-based cloning, estimation of diversity in germplasm collection to understand the population structure as well as in the area of comparative genomics. While dealing the above topics, major emphasis have been given on modern genomics tools and approaches such as functional molecular markers (EST-SSRs, EST-SNPs, SFPs), expression genetics or genetical genomics, high throughput approaches and automation technologies, public databases, etc. Utilization of modern genomics approaches such as functional genomics coupled with molecular marker technologies have a great potential to facilitate plant breeding practices and thus marker-assisted breeding seems to be evolved to genomics-assisted breeding in the near future

Evolution of the grain dispersal system in barley

Published: July 30, 2015About 12,000 years ago in the Near East, humans began the transition from hunter-gathering to agriculture-based societies. Barley was a founder crop in this process, and the most important steps in its domestication were mutations in two adjacent, dominant, and complementary genes, through which grains were retained on the inflorescence at maturity, enabling effective harvesting. Independent recessive mutations in each of these genes caused cell wall thickening in a highly specific grain "disarticulation zone," converting the brittle floral axis (the rachis) of the wild-type into a tough, non-brittle form that promoted grain retention. By tracing the evolutionary history of allelic variation in both genes, we conclude that spatially and temporally independent selections of germplasm with a non-brittle rachis were made during the domestication of barley by farmers in the southern and northern regions of the Levant, actions that made a major contribution to the emergence of early agrarian societies.Mohammad Pourkheirandish, Goetz Hensel, Benjamin Kilian, Natesan Senthil, Guoxiong Chen, Mohammad Sameri, Perumal Azhaguvel, Shun Sakuma, Sidram Dhanagond, Rajiv Sharma, Martin Mascher, Axel Himmelbach, Sven Gottwald, Sudha K. Nair, Akemi Tagiri, Fumiko Yukuhiro, Yoshiaki Nagamura, Hiroyuki Kanamori, Takashi Matsumoto, George Willcox, Christopher P. Middleton, Thomas Wicker, Alexander Walther, Robbie Waugh, Geoffrey B. Fincher, Nils Stein, Jochen Kumlehn, Kazuhiro Sato, and Takao Komatsud

Evolution of the grain dispersal system in barley

SummaryAbout 12,000 years ago in the Near East, humans began the transition from hunter-gathering to agriculture-based societies. Barley was a founder crop in this process, and the most important steps in its domestication were mutations in two adjacent, dominant, and complementary genes, through which grains were retained on the inflorescence at maturity, enabling effective harvesting. Independent recessive mutations in each of these genes caused cell wall thickening in a highly specific grain “disarticulation zone,” converting the brittle floral axis (the rachis) of the wild-type into a tough, non-brittle form that promoted grain retention. By tracing the evolutionary history of allelic variation in both genes, we conclude that spatially and temporally independent selections of germplasm with a non-brittle rachis were made during the domestication of barley by farmers in the southern and northern regions of the Levant, actions that made a major contribution to the emergence of early agrarian societies