Search results for "engineering.material"
showing 10 items of 2352 documents
Cactus pear (Opuntia ficus-indica) productivity, proximal composition and soil parameters as affected by planting time and agronomic management in a …
2021
Study of appropriate planting time and response to agronomic management practices is imperative for the newly introduced cactus pear (Opuntia ficus-indica (L.) Mill.) into a semi-arid region of India. Responses of cactus pear to agronomic practices (planting time and irrigation and fertilizer application) were evaluated to determine the potential for fodder production and livestock feed in a semi-arid environment of India. We assessed four planting times (February, March, July and October) and two agronomic managements (with and without irrigation and fertilizer application) during 2016–2020 at Jhansi, India. Cactus pear establishment and growth improved with planting time in July and Octob…
Incomplete retention of radiation damage in zircon from Sri Lanka
2004
A suite of 18 zircon gemstones from placers in the Highland/Southwestern Complex, Sri Lanka, were subjected to a comprehensive study of their radiation damages and ages. The investigation included X-ray diffraction, Raman and PL spectroscopy, electron microprobe, PIXE and HRTEM analysis, as well as (U-Th)/He and SHRIMP U-Th-Pb age determinations. Zircon samples described in this study are virtually homogeneous. They cover the range from slightly metamict to nearly amorphous. Generally concordant U-Th-Pb ages averaging 555 ± 11 Ma were obtained. Late Ordovician zircon (U-Th)/He ages scattering around 443 ± 9 Ma correspond reasonably well with previously determined biotite Rb-Sr ages for rock…
A coupled lossy local-mode theory description of a plasmonic tip
2012
International audience; We investigate power propagation in a metal-coated tapered optical fiber. We analyze in detail the conversion from the fiber core guided mode to a surface plasmon polariton (SPP) confined at the tip apex. To this aim, we adapt coupled local-mode theory to include lossy modes. Two distinct regimes are identified. In the case of thin metal coating, a strong coupling regime occurs between a core guided mode and a SPP with good conversion efficiency. In the case of thick metal coating, a very weak coupling occurs. Finally, energy confinement and the role of Joule losses are discussed in the near-infrared and visible ranges. Moreover, the coupled equations derived for loc…
Observations on ant-plant interactions in Pachycentria and other genera of the Dissochaeteae (Melastomataceae) in Sabah and Sarawak
1998
Summary In Sabah and Sarawak (Malaysia) ant-plant interactions of Dissochaeteae were studied in the field. Whereas some species of Dissochaeteae show only loose and fortuitous interactions with ants as the result of the provision of pearl bodies and nesting places which are used by ants facultatively, Pachycentria constricta and P. glauca show a complex relationship with ants mediated by other ant plants. Both species provide pearl bodies and potential nesting space or shelter for ants in dried out and hollow root swellings. The main characteristic which differentiates them from all other Melastomataceae interacting with ants are their particular seeds which are attractive to ants and carri…
Effect of high power ultrasound on physical–chemical properties of polypropylene films aimed for food packaging: structure and surface features
2019
International audience; Biaxially oriented polypropylene (BOPP) coated with acrylic/polyvinylidene chloride (BOPPAcPVDC) and biaxially oriented coextruded polypropylene (BOPPcoex) films have been treated with high power ultrasound (HPUS) while submerged in water. Polymer structure and the surface morphology changes were noticed, and obtained results were correlated with the physical properties of tested materials. In anticipation of sonochemically enhanced reactions, physical–chemical profile of film samples was determined using thermogravimetric analysis, differential scanning calorimetry, Fourier-transform infrared spectroscopy, UV spectrophotometry and environmental scanning electron mic…
Late Cretaceous palaeoenvironments expressed by the clay mineralogy of Cenomanian–Campanian chalks from the east of the Paris Basin
2005
Abstract The clay fraction of Cenomanian–Campanian chalks cored at Poigny and Sainte-Colombe, close to Provins (east-south-east of Paris), includes variable proportions of smectitic minerals, illite and kaolinite. The smectitic sediments (which constitute the background of low-terrigenous supply throughout the stratigraphic interval) resulted mainly from the warm, humid climate and high sea level that prevailed during Late Cretaceous in this area. During the Late Turonian, the smectitic sedimentation was interrupted by significant detrital inputs of illite and kaolinite. This reflected tectonic rejuvenation of landmasses coeval with an explosive volcanism expressed by the occurrence of bent…
Shallow structures at the outer Calabrian accretionary wedge (NW Ionian Sea): new insights from recently migrated reflection data
2010
Terra Nova, 00, 000–000, 2010 Abstract Post-stack time migration of a set of seismic reflection profiles reveals details of the stratigraphic–structural setting of the outermost Calabrian accretionary wedge, in the NW sector of the Ionian Sea, with particular emphasis on the Messinian stratigraphy and the deformation style of the thin frontal portion of this wedge. A structural style and seismic facies analysis, calibrated by refraction data, images a general bipartition of the Messinian evaporite deposits: the `lower subunit', consisting mainly of salt, appears to have undergone ductile-flow deformation, and the `upper subunit', consisting mainly of gypsum and marls, appears to be characte…
Palladium nanoparticles immobilized on halloysite nanotubes covered by a multilayer network for catalytic applications
2018
The synthesis of pure fine chemicals for industrial purposes is one of the most attractive challenges of chemical research. The use of catalytic pathways mediated by palladium nanoparticles (PdNPs) for C-C bond formation is a useful way to obtain these kinds of compounds. To achieve this objective, the PdNPs can be efficiently loaded on a functionalized natural nanostructured support such as halloysite nanotubes (HNTs). Hybrid materials based on thiol functionalized halloysite nanotubes and highly cross-linked imidazolium salts were successfully developed and used for the stabilization of PdNPs. The HNT/Pd hybrids were thoroughly characterized from a physico-chemical point of view and teste…
First record of early Aptian Oceanic Anoxic Event 1a from the Paris Basin (France) - Climate signals on a terrigenous shelf
2021
Abstract In 2013, Andra (French National Radioactive Waste Management Agency) drilled boreholes to the south-east of the Paris Basin, to characterise Aptian and Albian clayey formations, including the ‘Argiles a Plicatules’ Formation dated as early Aptian. One of these boreholes intersected this formation with an excellent recovery allowing detailed biostratigraphy (ammonites), sedimentology, clay mineralogy, isotope geochemistry (δ13Corg) and Rock-Eval analyses to be performed. The base of the formation corresponds to transgressive dark-grey silty clays with iron oolites and plant debris indicating a coastal environment evolving up-section to upper offshore environments. Higher in the succ…
Palynology and lithostratigraphy of Late Elsterian to Early Saalian aquatic sediments in the Ziemupe–Jūrkalne area, western Latvia
2000
Abstract This study is based upon lithological and palynological investigation of test-drilling cores along the Baltic Sea coast. Three intertill units of basin sediments are underlain by a thin layer of Lētiža (Elsterian) till and overlain by glaciotectonically deformed Kurzeme (Saalian Complex) till. The Kurzeme till differs from the Lētiža till by higher contents of limestone clasts and rounded hornblende grains. The lowermost intertill unit consists of glaciolacustrine to glaciomarine laminated clay of the Sudrabi member, a late glacial deposit of the Lētiža glaciation. Treeless vegetation covered the adjoining land. Next is the marine to brackish Akme n rags formation, deposited during…