Search results for "engineering.material"
showing 10 items of 2352 documents
Flame foliation: Evidence for a schistosity formed normal to the extension direction
2007
Abstract Foliations are normally thought to develop approximately parallel to the XY-plane of the finite strain ellipsoid, i.e., perpendicular to the main shortening direction. We present a new type of schistosity named “flame foliation” that forms orthogonal to the main extension direction, approximately parallel to the YZ-plane of finite strain. Flame foliation consists of anastomosing biotite-rich selvedges overprinting S1 in pelitic layers of metaturbitites in NW Namibia. The biotite crystals in the selvedges are peculiar because they are oriented oblique or orthogonal to the flame foliation itself and parallel to the previous S1 cleavage, a feature no other foliation shows. In some cas…
Out of sight : Profiling soil characteristics, nutrients and bacterial communities affected by organic amendments down to one meter in a long-term ma…
2019
Common soil characteristics, nutrients and microbial activity at deeper soil depths are topics seldom covered in agricultural studies. Biogeochemical cycles in deep soils are not yet fully understood. This study investigates the effect of different mineral and organic fertilisation on soil organic matter dynamics, nutrients and bacterial community composition in the first meter of the soil profiles in the long-term maize cropping system experiment Tetto Frati, near the Po River in northern Italy. The following treatments have been applied since 1992: 1) crop residue removal (CRR), 2) crop residue incorporation (CRI), 3) crop residue removal with bovine slurry fertilisation (SLU), 4) crop re…
Nitrogen Use Efficiency and Nitrogen Fertilizer Recovery of Durum Wheat Genotypes as Affected by Interspecific Competition
2010
A better understanding of the genotype response to N fertilization under weed competition is necessary to identify varieties that exhibit high N use effi ciency even when weeds compete for available N. Such varieties may be more suitable for low input or organic systems. Th is study assessed the variations in nitrogen use effi ciency (NUE) (and its components) and the recovery of 15 N-labeled fertilizer in three durum wheat (Triticum durum Desf.) genotypes (one landrace and two varieties that diff er in terms of plant growth, grain yield potential, and adaptability to stressful environments) grown in the presence or absence of interspecifi c competition and varying soil N availability (0 or…
ASSESSMENT OF THE IMPACT OF VERMICOMPOST AND PEAT EXTRACTS ON NUTRIENT ACCUMULATION IN TUBERS AND POTATO YIELD
2018
Investigations on the potential beneficial effect of humic substances on crop plant cultivation under extremely diverse soil and climatic conditions is of global character, thereby knowledge obtained on the basis of local investigations are of great importance world-wide. The aim of the research was to evaluate the effect of different application methods (seed tuber treatment and foliar application) of commercially-produced peat and vermicompost extracts on nutrient uptake in tubers and yield of potato ( Solanum tuberosum L.) using field experiments in organic farming system with potato variety ‘Borodjanskij Rozovij’. The tested extracts from the organic products included: peat extract (K45…
Relationship between N-cycling communities and ecosystem functioning in a 50-year-old fertilization experiment.
2009
The relative importance of size and composition of microbial communities in ecosystem functioning is poorly understood. Here, we investigated how community composition and size of selected functional guilds in the nitrogen cycle correlated with agroecosystem functioning, which was defined as microbial process rates, total crop yield and nitrogen content in the crop. Soil was sampled from a 50-year fertilizer trial and the treatments comprised unfertilized bare fallow, unfertilized with crop, and plots with crop fertilized with calcium nitrate, ammonium sulfate, solid cattle manure or sewage sludge. The size of the functional guilds and the total bacterial community were greatly affected by …
Ti2Sn3: A Novel Binary Intermetallic Phase, Prepared by Chemical Transport at Intermediate Temperature
2000
Ti2Sn3 was obtained by chemical transport using iodine as the transport agent in a sealed quartz ampule at 500 °C. Its crystal structurea new type structurewas determined via single-crystal structure analysis to be orthorhombic, space group Cmca, a = 595.56(4), b = 1996.4(2), c = 702.81(5) pm, V = 835.6(1) × 106 pm3, and Z = 8. The structure can be derived from a three-dimensional condensation of a single polyhedron, which comprises a Ti atom in the center, surrounded by seven Sn and four Ti atoms forming a tri-capped square antiprism. Supporting the results of the self-consistent band structure calculations, Ti2Sn3 is a metallic p-type conductor, exhibiting Pauli paramagnetism and a specif…
High-Fluence Implantation of Erbium into Silicon-Germanium Alloys: Structural and Thermal Properties
2000
AbstractHigh-quality crystalline Si1-xGex (x=0.10 and 0.25) alloys were implanted with 70 keV Er+ ions at temperatures of 350°C and 550°C to a fluence of 1015 cm−2. In-situ Rutherford backscattering/channeling (RBS) analysis supplemented with transmission electron microscopy (TEM) showed that as-implanted alloys were in form of ternary solid solutions with a peak Er concentration of 1 at.% without any trace of Er-Si or Er-Ge precipitation.In the samples implanted at 350°C Er atoms were found to be distributed randomly in the amorphous host matrix. Post-implantation annealing at different temperatures up to 600° showed that the solid phase epitaxial regrowth of the damaged layers strongly de…
Cover Feature: Electrochemical Installation of CFH 2 −, CF 2 H−, CF 3 −, and Perfluoroalkyl Groups into Small Organic Molecules (Chem. Rec. 9/2021)
2021
Morphologische Strukturen und Rißbildung in kristallinen, makromolekularen Stoffen
1962
Nach einem kurzen Uberblick uber die heutigen Kenntnisse der morphologischen Strukturen (Lamellen, Fibrillen und Spharolithe) werden die Versuche besprochen, und mit Hilfe von Permeations- und Diffusionsmessungen an Terylenfilmen in Abhangigkeit vom Kristallisationsgrade und der Temperatur einen Einblick in das innere Rissystem won makromolekularen Werkstoffen zu bekommen. Es zeigt sich, das man bei schonender thermischer und mechanischer Behandlung eine grobere durchgehende Risbildung u. entsprechende Korrosionsanfalligkeit durchaus vermeiden werden kann. Kristallisiert man zu lange bei zu hohen Temperaturen so tritt Risbildung auf. Hier kommen dann mikroskopische Untersuchungen sowie solc…