Search results for "yield"
showing 10 items of 1338 documents
Storing energy crops for methane production: Effects of solids content and biological additive
2007
The effect of storage on chemical characteristics and CH4 yield (taking into account loss of VS during storage) of a mixture of grasses and ryegrass, ensiled as such (low solids content) and after drying (medium and high solids) with and without biological additive, were studied in field and laboratory trials. Up to 87% and 98% of CH4 yield was preserved with low solids grass (initial TS 15.6%) and high solids ryegrass (initial TS 30.4%), respectively, after storage for 6months, while under suboptimal conditions at most 37% and 52% of CH4 yield were lost. Loss in CH4 yield was mainly due to VS loss, presumably caused by secondary fermentation as also suggested by increasing pH during storag…
Ozone-induced reductions in below-ground biomass: an anatomical approach in potato
2010
[EN] Potato plants were grown in open-top chambers under three ozone concentrations during two complete cropping seasons (93 and 77 d in 2004 and 2005, respectively). The effects of chronic exposure to ozone on leaf anatomy, cell ultrastructure and crop yield were studied. Severe cell damage was found, even at ambient ozone levels, mainly affecting the spongy parenchyma and areas near the stomata. Damage to the cell wall caused loss of cell contact, and loss of turgor pressure due to tonoplast disintegration, contributed to cell collapse. Phloem sieve plates were obstructed by callose accumulation, and damaged mesophyll cells increased their starch stores. Tuber yield fell sharply (24–44%),…
Gametic embryogenesis and haploid technology as valuable support to plant breeding
2011
Plant breeding is focused on continuously increasing crop production to meet the needs of an ever-growing world population, improving food quality to ensure a long and healthy life and address the problems of global warming and environment pollution, together with the challenges of developing novel sources of biofuels. The breeders' search for novel genetic combinations, with which to select plants with improved traits to satisfy both farmers and consumers, is endless. About half of the dramatic increase in crop yield obtained in the second half of the last century has been achieved thanks to the results of genetic improvement, while the residual advance has been due to the enhanced managem…
Preliminary studies on the synthesis of alkaline-free large crystals of ZSM-5
1988
Single crystals of ZSM-5 were synthesized in three systems containing Na + -TPA, Li + -TPA, and NH 4 + -TPA, respectively. Applying a reaction mixture of the molar composition 8 TPA + 123(NH 4 ) 2 O + Al 2 O 3 + 59 SiO 2 + 2280 H 2 O, alkaline-free, homogeneous, and pure single crystals of ZSM-5 were prepared up to a length of 350 μm. The crystal size and yield were found to be dependent on the water content of the starting reaction mixture and on the type of aluminium source; for example, boehmite and aluminiumtriisopropylate.
Factorial Design in the Ammonia Based Synthesis of Large Uniform MFI, MEL, DOH, and DOH/DDR Type Zeolite Crystals
1989
This study reports the synthesis of large and uniform crystals of high-silica zeolite materials. Statistic factorial design was applied in order to determine significant parameters for the rapid growth of alkali-free crystals out of ammonia-based synthesis systems. For silicalite-I, high ammonia contents at low water concentrations yielded crystals up to 300 μm in size. The number of crystal nuclei in type MFI synthesis systems was found to be significantly reduced by increasing ammonia and aluminium contents. MEL-type zeolites could be prepared only with the smaller size of 15 μm. Low water concentrations improved the product yield. Aminoadamantane as a guest molecule nucleated highly unif…
The molecular glass state in KBr1-x (CN)x
1985
Structural and dynamic properties of the molecular glass KBr1-x (CN)X are reported. The low temperature state can be characterized as an averaged crystal, where clusters of correlated frozen-in CN- ions yield a distribution of frozen-in lattice strains which destroy the rigorous center-of-mass periodicty of the high temperature phase. The freezing process measured via cusps in the dipolar and quadrupolar susceptibilities is a relaxional phenomenon and depends sensitively on the timescale of the experiment.
Tetranitroresorcin[4]arene: synthesis and structure of a new stereoisomer
2009
The direct reaction between 2-nitroresorcinol and acetaldehyde in alkaline medium yields tetranitro-C1-resorcin[4]arene in a moderate 8.2% overall yield which was characterized by single crystal X-ray crystallography, 1H NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS). In solution and in the solid state, the product adopts a unique, thermally stable and unprecedented rcct-boat conformation.
Liquid crystals in the series of 2,4,6-tristyryl-1,3,5-triazines
2004
Abstract Alkaline condensation reactions of 2,4,6-trimethyl-1,3,5-triazine ( 1 ) and substituted benzaldehydes ( 2a – n ) yield 2,4,6-tristyryl-1,3,5-triazines ( 3a – n ). A sufficient number and length of the alkoxy chains at the benzene rings provide liquid crystalline phases Col hd . A special structure was found for compound 3i with 9 hexyloxy chains; it exists in the solid state in a helical columnar arrangement, which is transformed by heating to a hexagonal columnar mesophase. Irradiation of the mesophases of 3i – 3m leads to partial cyclodimerization reactions, which cause different textures and lower the clearing points. The border line between the irradiated and the unirradiated z…
Valutazione di ecotipi siciliani di melone d'inverno coltivati in regime seccagno
2010
The increasing cultivation of hybrid melon cultivars has caused the loss of several Sicilian landraces characterized by a high level of diversity, tolerance to environmental stress, disease resistance, and high quality fruits. Although the majority of hybrid melon fields in the Sicilian countryside are nowadays irrigated, many farmers are still growing melon landraces without irrigation. In this trial, eight Sicilian landraces of winter melon (Cucumis melo L. var. inodorus Naud.) with yellow skin and three with white skin were compared with the commercial cultivar Helios. Plants were grown at a density of 2080 plants ha-1. without irrigation. ‘Locale di Ustica’ and ‘Giallo di Recattivo’ gav…