Probability density functions of photochemicals over a coastal area of Northern Italy

The present paper surveys the findings of experimental studies and analyses of statistical probability density functions (PDFs) applied to air pollutant concentrations to provide an interpretation of the ground-level distributions of photochemical oxidants in the coastal area of Ravenna (Italy). The atmospheric pollution data set was collected from the local environmental monitoring network for the period 1978-1989. Results suggest that the statistical distribution of surface ozone, once normalised over the solar radiation PDF for the whole measurement period, follows a log-normal law as found for other pollutants. Although the Weibull distribution also offers a good fit of the experimental data, the area’s meteorological features seem to favour the former distribution once the statistical index estimates have been analysed. Local transport phenomena are discussed to explain the data tail trends

Performance analysis of a ultra-compact low-power rectenna in paper substrate for RF energy harvesting

In this paper the experimental results of a compact low-power rectenna in paper substrate, designed to operate in the Wi-Fi band, are presented. The complete prototype, based on an annular slot antenna and a single-diode rectifier, features a weight of 1.5 grams and shows an RF-to-dc conversion efficiency in the design band of about 40 % for a -10 dBm available input power, of about 28 % at -15 dBm, and in the range [10, 22] % at -20 dBm, corresponding to an output DC voltage in the order of 320, 240 and 60 mV respectively. Additionally, the rectenna features an efficiency higher then 7 % in the whole band 1.8-2.7 dBm for a power density estimated around 3 μW/cm2.Grant numbers : The work was supported by the EU COST Action IC1301 WiPE (Wireless Power Transmission for sustainable Electronics). © 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

The impact of minimum wages on wages and employment: evidence from Greece

This paper investigates the impact of minimum wages on wages and employment in Greece between 2009 and 2017. Our main contribution is the examination of the effects of minimum wages under a dramatically changing context, as during this period Greece has experienced the deepest recession in its recent history, extensive labour market reforms, and several changes in the minimum wage, including a large decrease. Employing a unique administrative panel matched employer-employee data set and a range of estimators, such as difference-in-differences, fixed effects, and Instrumental Variables, we find that minimum wages have a positive and significant effect on individual and firm-level wages with significant positive wage spill-overs extending, sometimes, above the median wage, but no systematic employment effects

Minimum Wages and Firm Employment: Evidence from a Minimum Wage Reduction in Greece

© 2020 The Authors. We investigate firm heterogeneity in responses to minimum wage changes leveraging on a policy reform in 2012 in Greece that introduced a youth sub-minimum through a sharp reduction in the minimum wage that was larger for youth. Using administrative linked employer–employee panel data and a difference-in-differences estimator, we find that, although wages decreased across all firms following the policy reform, adult wages decreased by more, whereas youth wages decreased by less in firms with a higher share of youth in employment. We also find that, in these firms, adult employment increased by more, while youth employment increased by less or even decreased and that these changes reflected mainly new hires rather than job separations. These heterogeneous responses to the change in the minimum wage across firms are not entirely consistent with the competitive model of the labour market

Seasonal budgets of ozone and oxidant precursors in an industrial coastal area of northern Italy

The seasonal budgets and evolution of photochemical oxidants reported for greater Ravenna's urban-industrial area in the present study were calculated using the combined data from on-site systematic surveys (1978-1989) and from the monitoring network of the local environmental authorities. The notable differences in the concentrations of ozone and nitrogen oxides depended on season, and meteorological variables showed a marked correlation to the seasonal budget of trace constituents. The weak local circulation, the land-sea breeze system, and high solar radiation in summer, which may persist at length because of the anticyclonic conditions, can produce episodes of intense photochemical reactions. In winter, by contrast, low solar radiation and the absence of the breeze system results in very different evolutions of both pollutant concentrations and their seasonal budget

Recent results from the Arctic Radiation and Turbulence Interaction STudy (ARTIST) project

Ground-based measurements were conducted at Ny-˚Alesund in the Svalbard Islands in the framework of the research project ARTIST (Arctic Radiation and Turbulence Interaction STudy) funded by the European Communities. Key objectivesof the campaign were: 1) provide all participantswith ground reference data as input to models describing the development of the atmospheric boundary level, 2) compute the surface roughness length in order to characterise the surface of the site, 3) parameterise the surface energy exchanges, calculating the surface radiation flux, the sensible and latent heat fluxes, and 4) obtain the surface energy balance during both clear and cloudy sky conditions. The cloud radiative forcing has been also estimated. Final results of the analysis of the data set are presented

Using Strategy Improvement to Stay Alive

We design a novel algorithm for solving Mean-Payoff Games (MPGs). Besides solving an MPG in the usual sense, our algorithm computes more information about the game, information that is important with respect to applications. The weights of the edges of an MPG can be thought of as a gained/consumed energy -- depending on the sign. For each vertex, our algorithm computes the minimum amount of initial energy that is sufficient for player Max to ensure that in a play starting from the vertex, the energy level never goes below zero. Our algorithm is not the first algorithm that computes the minimum sufficient initial energies, but according to our experimental study it is the fastest algorithm that computes them. The reason is that it utilizes the strategy improvement technique which is very efficient in practice

Spectral curves of surface reflectance in some antarctic regions

Four surface reflectance models of solar radiation were determined by examining several sets of field measurements taken for clear-sky conditions at various sites in Antarctica. Each model consists of the mean spectral curve of surface reflectance in the 0.25–2.7 μm wavelength range and of the dependence curve of total albedo on the solar elevation angle h, within the range from 5◦ to 55◦. The TNB (Terra Nova Bay) model refers to a rocky terrain where granites are predominant; the NIS (Nansen Ice Sheet) model to a glacier surface made uneven by sastrugi and streaked by irregular fractures; the HAP (High Altitude Plateau) model to a flat ice surface covered by fresh snow and scored by light sastrugi; and the RIS (Ross Ice Shelf) model to an area covered by the sea ice pack presenting many discontinuities in the reflectance features, due to melt water lakes, puddles, refrozen ice and snow pots. The reflectance curve obtained for the TNB model presents gradually increasing values as wavelength increases through the visible spectral range and almost constant values at infrared wavelengths, giving a total albedo value equal to 0.264 at h = 30◦, which increases by about 80% through the lower range of h and decreases by 12% through the upper range. The reflectance curves of the NIS, HAP and RIS models are all peaked at visible wavelengths and exhibit decreasing values throughout the infrared spectral range, giving values of total albedo equal to 0.464, 0.738 and 0.426 at h = 30◦, respectively. These values were estimated to increase by 8–14% as h decreases from 30◦ to 5◦ and to decrease by 2–4% only as h increases from 30◦ to 55◦

Prospectus, June 19, 2001

https://spark.parkland.edu/prospectus_2001/1017/thumbnail.jp