1,316 research outputs found
Properties and characterization of ALD grown dielectric oxides for MIS structures
We report on an extensive structural and electrical characterization of
under-gate dielectric oxide insulators Al2O3 and HfO2 grown by Atomic Layer
Deposition (ALD). We elaborate the ALD growth window for these oxides, finding
that the 40-100 nm thick layers of both oxides exhibit fine surface flatness
and required amorphous structure. These layers constitute a base for further
metallic gate evaporation to complete the Metal-Insulator-Semiconductor
structure. Our best devices survive energizing up to ~3 MV/cm at 77 K with the
leakage current staying below the state-of-the-art level of 1 nA. At these
conditions the displaced charge corresponds to a change of the sheet carrier
density of 3 \times 1013 cm-2, what promises an effective modulation of the
micromagnetic properties in diluted ferromagnetic semiconductors.Comment: 8 pages, 5 figures, 14 reference
A new centric diatom genus from the Sub-Antarctic region with striking similarities to a cretaceous fossil
Applying Advanced ICT Technologies and Augmented Reality To Generate Future Events On The Example of Organisation and Education in Sports Methodological Assumptions
The article follows up on two research and implementation grants. One focused on the application of mobile ICT systems to improve communication efficiency within the structure of the AZS-AWF Wroc?aw sports club (e-AZS platform). The other was devoted to the application of the technology of augmented reality to prototype educational trainers as seen on the example of judo. The two projects are to result in the development of original software improving the systems of sports organisation and education. It is assumed that linearity of events means that present effects have their causes solely in events from the past. While this is true, we cannot reject a thesis whereby present events may also result from events located in the future. Weather forecast will never change the weather, but forecasts of stock market trends can and do influence current stock prices in a significant way (after [1]). Thus, one of the new paradigms we can put forward is the thesis saying that future events generated in the information field may be the cause of what is yet to happen. The authors adopt this new paradigm as they explore the areas of sports education and organisation focusing on the specific examples of the sports training process and the organisational system of sports clubs. Using advanced IT technologies, they have described and explained the methodological basis of the adopted paradigm in the form of a prototype trainer to be used in martial arts including judo and the e-ASZ platform, a tool used in the AZS-AWF Wroc?aw sports club to organise training activities.Hence, the paper describes the application of advanced information and communications technologies (ICT) to manage the organisational aspect of the sports club as well as augmented reality as a technology to create a new reality through augmenting its real (augmented reality), virtual (augmented virtuality) and medial (augmented mediality) aspects (research in 2013-2016 and 2015-2017 by the Ministry of Science and Higher Education, supervised by dr hab. Wojciech B. Cieslinski prof. at AWF Wroclaw grant numbers: 0014/RS2/2013/52, and dr hab. Kazimierz Witkowski 0011/RS3/2015/53)
North Atlantic marine biogenic silica accumulation through the early-to-mid Paleogene: implications for ocean circulation and silicate weathering feedback
The Paleogene history of biogenic opal accumulation in the North Atlantic provides insight into both the evolution of deep-water circulation in the Atlantic basin, and weathering responses to major climate shifts. However, existing records are compromised by low temporal resolution and/or stratigraphic discontinuities. In order to address this problem, we present a multi-site, high-resolution record of biogenic silica (bioSiO2) accumulation from Blake Nose (ODP Leg 171B, western North Atlantic) spanning the early Paleocene through late Eocene time interval (~65‒34 Ma). This record represents the longest single-locality history of marine bioSiO2 burial compiled to date and offers a unique perspective into changes in bioSiO2 fluxes through the early-to-mid Paleogene extreme greenhouse interval and subsequent period of long-term cooling. Blake Nose bioSiO2 fluxes display prominent fluctuations that we attribute to variations in sub-thermocline nutrient supply via cyclonic eddies associated with the Gulf Stream. Whereas few constraints are available on the bioSiO2 flux pulses peaking in the early Paleocene and early Eocene, a middle Eocene interval of elevated bioSiO2 flux between ~46 and 42 Ma is proposed to reflect nutrient enrichment due to invigorated overturning circulation following an early onset of Northern Component Water export from the Norwegian-Greenland Sea at ~49 Ma. Comparison of our North Atlantic record against published Pacific bioSiO2 flux records indicates a diminished nutrient supply to the Atlantic between ~42 and 38 Ma, interpreted as a response to weakening of the overturning circulation. Subsequently, a deep-water circulation regime favoring limited bioSiO2 burial in Atlantic and enhanced bioSiO2 burial in the Pacific was established after ~38 Ma, likely in association with a further invigoration of deep-water export from the North Atlantic. We also observe that Blake Nose bioSiO2 fluxes through the middle Eocene cooling interval (~48 to 34 Ma) are consistently higher than background fluxes throughout the late Paleocene‒early Eocene interval of intense greenhouse warmth. This observation is consistent with a temporally variable rather than constant silicate weathering feedback strength model for the Paleogene, which would instead predict that marine bioSiO2 burial should peak during periods of extreme warming
Valuation of communal area livestock benefits, rural livelihoods and related policy issues
The multiple benefits from livestock production to rural households are evaluated in Thorndale, a communal area of the Limpopo Province South Africa. Monetary values of livestock products are presented. Values from most previous studies are static (and thus outdated), as a result of conceptual and methodological shifts. The net monetary value of the direct benefits from livestock was estimated as 33 per household/annum. Policy concerns are the provision of adequate market and pricing mechanisms for communal area livestock, tailored savings, investment support, credit schemes, and infrastructure. An appropriate multipurpose benefit production model, other than a commercialised model is suggested for the sector
Conceptualizing the human use of wild edible herbs for conservation in South African communal areas
The importance of wild edible herbaceous species to resource poor households in most rural economies within savannas has been little studied. This is because most of the herbs grow in impoverished species communities and lands, often referred to as ‘marginal lands’. The aim of this paper is to conceptualize how the economics of wild edible herbs to households can be used to add value to total livelihoods and conservation within traditional communal areas of South Africa. Analysis of the economics of the consumption of wild edible herbs in Thorndale (Bushbuckridge district) of the Limpopo province is presented. The majority of households consumed wild edible herbs, averaging 15.4 kg dried weight per household per year and valued at $167 per household. The herbs were mostly harvested from uncultivated areas of farms, and rangelands. There was little correlation between household characteristics and the dependence on wild herbs for food. The local people noted a decline in the availability of the species, although not much is known about attempts to cultivate them. The only reasons attributed to the decline were nutrient poor soils and insufficient rains. With this background, developing a local strategy to sustain the species through cultivation by households was found to be feasible. A multiple-use system for the herbs, their improvement and value addition towards commercialization and increased household usage may result in wider acceptance and subsequent cultivation. Species diversity will be enhanced whilst conserving the land on which they grow. This multiple use system may include species roles in soil and water conservation
Effective Mg Incorporation in CdMgO Alloy on Quartz Substrate Grown by Plasma-assisted MBE
The development of CdMgO ternary alloy with a single cubic phase is
challenging but meaningful work for technological advancement. In this work, we
have grown a series of Cd1-xMgxO ternary random alloys with various Mg
concentrations (x = 0, 30, 32, 45, and 55%) on quartz substrate by
plasma-assisted molecular beam epitaxy (PA-MBE) technique. The structural
investigations of alloys were performed using the X-ray diffraction (XRD)
technique. The decreases in average crystallite size and lattice parameters
were observed with an increase in Mg content in the alloys. XRD analysis
confirms a single cubic phase is obtained for alloy compositions. The elemental
and morphological studies were carried out using energy dispersive x-ray (EDX)
spectroscopy and atomic force microscope (AFM) technique, respectively. The
optical investigation was carried out using UV-Vis spectroscopy. The optical
bandgaps were estimated using the Tauc relation and it was varied from 2.34 eV
to 3.47 eV by varying the Mg content from zero to 55% in the alloys. The Urbach
energy increases from 112 meV to 350 meV which suggests a more disordered
localized state with an increase in Mg incorporation in the alloys.Comment: 22 pages, 8 figures, 2 table
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