Search results for "LIMIT"
showing 10 items of 2826 documents
Opportunities and threats to contact lens practice: A global survey perspective
2021
Aim: To understand the views of contact lens (CL) practitioners across the globe regarding what they perceive as opportunities and threats in CL practice. Methods: A self-administered anonymised questionnaire, constructed in English and translated in six more languages, was distributed through reputed international professional bodies and academic institutions worldwide. The questionnaire included items on demographic characteristics, type of practice, and questions designed to explore practitioners’ perspective on the future of their CL practice over the next five years. Results: A total of 2408 valid responses were analysed. Multifocal CLs for presbyopia, CLs for myopia control, use of da…
Total content of As, Sb, Se, Te and Bi in Spanish vegetables, cereals and pulses and estimation of the contribution of these foods to the Mediterrane…
2010
Abstract As, Sb, Se, Te and Bi were quantified in vegetables, pulses and cereals, in order to increase the available information on the presence of these elements in the Mediterranean daily intake. Samples were dry ashed and the ashes dissolved with diluted HCl. Hydride generation atomic fluorescence spectrometry was used for quantification. Limits of detection (LOD) ranged from 0.2 to 1.7 ng g−1 and the accuracy was assessed by the analysis of three certified reference materials, Rice Flour (NIST 1568a), Tomato Leaves (NIST 1573) and Cabbage (IAEA 359). Good concordance between results found and certified values were always observed. As, Sb, Se, Te and Bi levels varied in samples analysed …
Study of the influence of temperature and precipitations on the levels of BTEX in natural waters.
2013
Assessment of seasonal changes in surface water quality is an important aspect for evaluating temporal variation of water due to natural or anthropogenic inputs of point and non-point sources. The objective of this paper was to investigate the influence of seasonal temperature fluctuations and precipitations on the levels of BTEX in natural waters. Principal component analysis (PCA) was used to evaluate the seasonal correlations of BTEX levels in water and to extract the parameters that are most important in assessing seasonal variations of water quality. This study was carried out as a part of VOCs monitoring program in natural water samples from Mediterranean coast. To carry out this proj…
The carrying capacity for Mediterranean bivalve suspension feeders: evidence from analysis of food availability and hydrodynamics and their integrati…
2004
Abstract In order to assess the carrying capacity of two Mediterranean areas, the Incze et al. model and its modification were applied. Our measures were carried out in the Gulf of Gaeta (Central MED), where mussels ( Mytilus galloprovincialis ) are intensively cultivated (production of approximately 200 t per year) and the Gulf of Castellammare (Southern MED), where bivalve culture is not widely practised. Velocities of water current and in field filtration rates were measured in each area. Total suspended matter (TSM), suspended chlorophyll-a (CHLa), lipid, protein and carbohydrate concentrations in the particulate were measured seasonally and used as tools to evaluate the trophic status …
Species identification of the psammophilous tenebrionid beetles Phaleria acuminata Juster, 1852 and Phaleria bimaculata (Linnaeus, 1767) from central…
2013
Dominating global arid environments, from desert to coastal dunes, most Tenebrionidae are highly specific in their habitat preferences and display limited dispersal potential, thus exhibiting a remarkable degree of regional genetic and morphological differentiation. The tenebrionid genus Phaleria is speciose and widely distributed, with P. acuminata and P. bimaculata having a wide Mediterranean distribution, with numerous morphological differentiations at population level, often described as different taxa of doubtful taxonomical significance. In order to investigate the variability of the central Mediterranean populations of P. bimaculata and P. acuminata and to compare the results obtaine…
Predicting rainfall erosivity by momentum and kinetic energy in Mediterranean environment
2018
Abstract Rainfall erosivity is an index that describes the power of rainfall to cause soil erosion and it is used around the world for assessing and predicting soil loss on agricultural lands. Erosivity can be represented in terms of both rainfall momentum and kinetic energy, both calculated per unit time and area. Contrasting results on the representativeness of these two variables are available: some authors stated that momentum and kinetic energy are practically interchangeable in soil loss estimation while other found that kinetic energy is the most suitable expression of rainfall erosivity. The direct and continuous measurements of momentum and kinetic energy by a disdrometer allow als…
EXACT SOLUTIONS FOR A CLASS OF FRACTAL TIME RANDOM WALKS
1995
Fractal time random walks with generalized Mittag-Leffler functions as waiting time densities are studied. This class of fractal time processes is characterized by a dynamical critical exponent 0<ω≤1, and is equivalently described by a fractional master equation with time derivative of noninteger order ω. Exact Greens functions corresponding to fractional diffusion are obtained using Mellin transform techniques. The Greens functions are expressible in terms of general H-functions. For ω<1 they are singular at the origin and exhibit a stretched Gaussian form at infinity. Changing the order ω interpolates smoothly between ordinary diffusion ω=1 and completely localized behavior in the …
OXYGEN SOLUBILITY IN NORMAL HUMAN BLOOD
1981
Publisher Summary This chapter describes oxygen solubility in normal human blood. The most crucial problem in measuring physically dissolved oxygen in blood is the prevention of oxygen binding by hemoglobin (Hb). The chapter discusses a study for the re-determination of oxygen solubility in untreated human blood. The oxygen concentration was measured by a photometric method and the Hb-concentration was determined by the cyanohemoglobin method. Oxygen solubility in normal and untreated blood is a linear function of the Hb-concentration. Hemoglobin in the reduced state has a greater influence on oxygen solubility than hemoglobin. Red cell membranes have no measureable effect on the oxygen sol…
A Sensitive Nanosensor for the In Situ Detection of the Cannibal Drug.
2020
[EN] A bio-inspired nanodevice for the selective and sensitive fluorogenic detection of 3,4- methylenedioxypyrovalerone (MDPV), usually known as Cannibal drug, is reported. The sensing nanodevice is based on mesoporous silica nanoparticles (MSNs), loaded with a fluorescent reporter (rhodamine B) and functionalized on their external surface with a dopamine derivative (3), which specifically interacts with the recombinant human dopamine transporter (DAT), capping the pores. In the presence of MDPV, DAT detaches from the MSNs consequently causing rhodamine B release and allowing drug detection. The nanosensor shows a detection limit of 5.2 µM and it is able to detect the MDPV drug both in sali…
L'arcivescovo e l'ospedale. Raimondo de Puyolis contro i gerosolimitani di Messina (1344)
2016
Il saggio focalizza un momento complesso della vita sociale e religiosa messinese di metà Trecento, che vede coinvolti da un lato Raimondo de Puyolis, arcivescovo catalano di Messina, dall'altro l'ospedale S. Giovanni di Gerusalemme: uno scontro scaturito dal mancato pagamento delle decime, dietro cui si celavano articolate politiche cittadine.