Search results for "medium"
showing 10 items of 3746 documents
WAITING FOR THE CAPITAL MARKET UNION: THE POSITION OF LATVIAN CORPORATE BOND MARKET
2017
Baltic region is traditionally treated as similar and comparable when analysed on the macroeconomic level. The major difference is faced when the analysis is performed for the corporate bond market – the weight of Latvian publically traded corporate bonds among the three countries- Latvia, Lithuania and Estonia- reached 94% by the number of issues quoted. With 47 corporate bonds listed in Nasdaq Riga, Latvian corporate bond market demonstrated the rapid growth and recognition of corporate bonds as the source of alternative to bank lending financing method (Nasdaq Baltic, 2017). There are no obvious macro or microeconomic evidence for Latvia meeting more favourable conditions for corporate b…
Fine-tuning of the confined space in microporous metal–organic frameworks for efficient mercury removal
2017
Offsetting the impact of human activities on the biogeochemical cycle of mercury has become necessary for a sustainable planet. Herein, we report the development of a water-stable and eco-friendly metal–organic framework, which has the formula {Cu4II[(S,S)-methox]2}·5H2O (1), where methox is bis[(S)-methionine]oxalyl diamide. Its features include narrow functional channels decorated with thioalkyl chains, which are able to capture HgCl2 from aqueous media in an efficient, selective, and rapid manner. The conscious design effort in terms of size, shape, and reactivity of the channels results in extremely efficient immobilization of HgCl2 guest species in a very stable conformation, similar t…
Velocity of the fourth sound in liquid helium II via extended thermodynamics
2003
This work continues a study begun in previous works, where, using Extended Thermodynamics, a monofluid model of liquid helium II is formulated. The wave propagation in bulk liquid helium II is studied in the hypothesis that the thermal dilatation is not zero. The propagation of fourth sound, studied previously neglecting both the thermal dilatation and finite volume of the powder, is studied without these simplified hypotheses: a scattering correction n is introduced to take into account the porosity. The model is more general than the standard two-fluid model because it allows that a small amount of entropy is associated with helium when it flows through a very thin capillary or a porous m…
Short and Medium Range Order in Se1-xTexGlasses
1997
Complementary XAFS measurements (LURE and NSLS) of Se 1 - x Te x glasses have been carried out on both the Se and Te K-edges at low and room temperatures. Using a multi-shell best fit analysis procedure, we have reconstructed the Se and Te local environment: (i) first shell intrachain nearest neighbors (Se-Se 1 , Se-Te 1 , Te-Se 1 ,and Te-Te 1 ); (ii) second shell intrachain (Se-Se 2 and Se-Te 2 ) and interchain next nearest neighbors (Se⇔Se 3 single scattering in the chains Se-Se 1 -Se 3 and Se-Te 1 -Se 3 ). For the first and second coordination shells we suggest that the intrachain chemical order increases with Te content. On the other hand, we propose a model of random distribution of Se…
Zirconia in fixed prosthesis. A literature review
2014
Statement of problem: Evidence is limited on the efficacy of zirconia-based fixed dental prostheses. Objective: To carry out a literature review of the behavior of zirconium oxide dental restorations. Material and Methods: This literature review searched the Pubmed, Scopus, Medline and Cochrane Library databases using key search words “zirconium oxide,” “zirconia,” “non-metal restorations,” “ceramic oxides,” “veneering ceramic,” “zirconia-based fixed dental prostheses”. Both in vivo and in vitro studies into zirconia-based prosthodontic restoration behavior were included. Results: Clinical studies have revealed a high rate of fracture for porcelain-veneered zirconia-based restorations that …
Varietal and geographic classification of french red wines in terms of pigments and flavonoid compounds
1988
Thirty-four French red wines originating from six different grape varieties and three different production areas were analysed in duplicate for 15 anthocyanins, ten flavonoids and three colour parameters, F-statistics, principal component analysis and stepwise discriminant analysis were used to identify and to explain differences among samples. Clear difference between wines made from different varieties were mainly related to anthocyanin 3-acylglucosides. Malvidin and peonidin 3-acetylglucosides were found in increasing concentrations in wines made respectively from Grenache, Carignan, Cinsault, Merlot, Carbernet Sauvignon and Cabernet Franc grapes; the concentrations of peonidin and malvi…
Influence of mechanical properties of the sheet material on formability in single point incremental forming
2004
Abstract New trends in sheet metal forming are rapidly developing and several new forming processes have been proposed to accomplish the goals of flexibility and cost reduction. Among them single point incremental forming operations, in which the final shape of the component is obtained by the relative movement of a simple and small punch with respect to the blank, appear quite promising. In the paper, material formability issues in incremental forming were studied. Some relevant correlations among material formability and other mechanical properties of the material were analysed. The FLD 0 value, i.e. the major strain at fracture in plane strain conditions, was determined for different mat…
Incremental forming of friction stir welded taylored sheets
2006
In the last decade sheet metal forming market has undergone substantial mutations since the development of more efficient strategies in terms of flexibility and cost reduction is strictly due. Such requirements are not consistent with traditional metal stamping processes which are characterized by complex equipment, capital and tooling costs; thus the industrial application of such processes is economically convenient just for large scale productions. For this reason most of the research work developed in the last years has been focused on the development of new sheet forming processes able to achieve the above discussed goals. Contemporary, with particular reference to the automotive indus…
Use of The Eggshells in Removing Heavy Metals from Waste Water - The Process Kinetics and Efficiency
2019
Abstract Studies of the efficiency of Ni, Cu and Cd cations removal from water solutions were carried out, with the use of clay limestone, hen eggshells from eggs for consumption and hen eggshells after hatching, which main element is calcium carbonate. Hen eggshells are a waste product, which can be used as a substitute of clay limestone in removing heavy metals from wet flue gas desulphurisation installation. Mixed solutions of Ni, Cu and Cd were used in the research, with the composition similar to the waste water from wet flue gas desulphurisation installation: Ni (0.009-0.053 mmol/dm3), Cu (0.008-0.057 mmol/dm3) and Cd (0.003-0.008 mmol/dm3). The metals were determined by flame atomic …
CHARACTERIZATION OF IRON COMPOUNDS FROM URBAN AND RURAL AEROSOL SOURCES
2000
Abstract Iron plays an important role in the chemistry and physics (by varying the hygroscopicity) of the atmosphere. Bulk samples were taken from an air-conditioning device, from the electrofilter of a gas–oil power station of the Technical University of and from rural sites near Darmstadt, situated between medium-altitude mountains and with a climate dominated by air masses from the west. Samples were collected in urban and rural (meadow) air, from different waste incineration power stations, from the exhausts of a gasoline and from a diesel motor car, and from a private gas fired heating system. The samples were characterized for elemental composition by total reflection X-ray fluorescen…