The Reference Distribution Method

The 19F quadrupole coupling constants in CF4, CHF3, CClF3 and CHClF2 are reported. The measurements were carried out temperature dependent using the time differential perturbed angular distribution method (TDPAD). The temperature dependence can be satisfactorily described in the framework of the Bayer-Kushida theory. A simple model is used to explain the appearance of H-F and Cl-F coupling constants in CHF3/CHClF2 and CClF3, respectively.

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A Proof-of-Concept Algorithm for the Retrieval of Total Column Amount of Trace Gases in a Multi-Dimensional Atmosphere

Remote Sensing ◽

10.3390/rs13020270 ◽

2021 ◽

Vol 13 (2) ◽

pp. 270

Author(s):

Adrian Doicu ◽

Dmitry S. Efremenko ◽

Thomas Trautmann

Keyword(s):

Trace Gases ◽

Three Dimensional ◽

Principal Component ◽

Radiative Transfer Model ◽

Computational Time ◽

Transfer Model ◽

Proof Of Concept ◽

Discrete Ordinate ◽

Distribution Method ◽

Total Column

An algorithm for the retrieval of total column amount of trace gases in a multi-dimensional atmosphere is designed. The algorithm uses (i) certain differential radiance models with internal and external closures as inversion models, (ii) the iteratively regularized Gauss–Newton method as a regularization tool, and (iii) the spherical harmonics discrete ordinate method (SHDOM) as linearized radiative transfer model. For efficiency reasons, SHDOM is equipped with a spectral acceleration approach that combines the correlated k-distribution method with the principal component analysis. The algorithm is used to retrieve the total column amount of nitrogen for two- and three-dimensional cloudy scenes. Although for three-dimensional geometries, the computational time is high, the main concepts of the algorithm are correct and the retrieval results are accurate.

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Different Scenarios for the National Transmission Grid, Considering the Extensive Use of On-Site Renewable Energy in the Mexican Housing Sector

Energies ◽

10.3390/en14010195 ◽

2021 ◽

Vol 14 (1) ◽

pp. 195

Author(s):

Ivan Oropeza-Perez ◽

Astrid H Petzold-Rodriguez

Keyword(s):

Renewable Energy ◽

Electricity Generation ◽

Housing Sector ◽

Distribution Grid ◽

Smart Meters ◽

Long Distance ◽

Distribution Method ◽

Transmission Grid ◽

Production And Consumption ◽

Transmission And Distribution

The Mexican national electricity transmission and distribution grid (SEN, initials in Spanish) is characterized by the high interconnection between its several electricity generation plants and the millions of final consumers throughout the country. This feature, which is seen first as an adequate transmission and distribution method for electricity between producer and consumer, has the inconvenience of being highly complex when renewable energy is introduced into the SEN. The random nature of renewable energy means that coordination between the producer and consumer is difficult; therefore, these energy sources are considered by the Mexican Federal Commission of Electricity (CFE, initials in Spanish) without priority in their generation and distribution. In this document, a solution for this is given by the consideration of on-site photovoltaic production in the Mexican residential sector, setting a straightforward relationship between production and consumption, neglecting the long-distance transmission, and freeing the transmission and distribution through the SEN at certain hours of the day. Different scenarios are studied, considering the level of penetration of this renewable energy technology into the housing sector. In this way, it is found that, if 80% of the total Mexican dwellings hold a photovoltaic roof, in some seasons of the year, a large part the total national demand can be fulfilled by the photovoltaic generation if certain systems—such as bidirectional smart meters—are applied. In this sense, the results show that, if 80% of the Mexican dwellings had a photovoltaic roof, there would be a money saving of 3418 Million USD and a mitigation of 25 million tons CO2e, for 2018. With this, it is concluded that renewable energy in Mexico could provide a much greater share if the electricity is produced in the same place where it will be consumed. This might be possible in Mexico due to the high interconnection of the transmission and distribution grid, which would manage the surplus electricity generation in the dwellings in a proper manner.

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Reference values of trace elements in blood and/or plasma in adults living in Belgium

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2020-1019 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Perrine Hoet ◽

Chantal Jacquerye ◽

Gladys Deumer ◽

Dominique Lison ◽

Vincent Haufroid

Keyword(s):

Trace Elements ◽

Reference Values ◽

Inductively Coupled Plasma ◽

Adult Population ◽

A Priori ◽

Selection Procedure ◽

Anthropogenic Sources ◽

Published Data ◽

Reference Distribution ◽

Belgian Population

AbstractObjectivesTrace elements (TEs) from natural and anthropogenic sources are ubiquitous. Essential or not, their relevance for human health and disease is constantly expanding. Biological monitoring is a widely integrated tool in risk assessment both in occupational and environmental settings. However, the determination of appropriate and accurate reference values in the (specific) population is a prerequisite for a correct interpretation of biomonitoring data. This study aimed at determining the reference distribution for TEs (Al, As, Sb, Be, Bi, Cd, Co, Cu, Mn, Hg, Mo, Ni, Pb, Se, Tl, Sn, V, Zn) in the blood and/or plasma of the adult population in Belgium.MethodsBlood and plasma samples were analyzed for 178 males and 202 females, recruited according to an a priori selection procedure, by inductively coupled plasma mass spectrometry (ICP-MS).ResultsReference values were established with high confidence for AsT, Cd, Cu, HgT, Mn, Mo, Pb, Sn, Se, Tl and Zn. Compared to previously published data in the Belgian population, a decreasing time trend is observed for Zn, Cd and Pb. Globally, the results also indicate that the current exposure levels to TEs in the Belgian population are similar to those from other recent national surveys.ConclusionsThese reference values and limits obtained through validated analytical and statistical methods will be useful for future occupational and/or environmental surveys. They will contribute to decision-making concerning both public health policies but also exposure assessments on an individual scale.

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Investigation of Feller-Buncher Performance Using Weibull Distribution

Forests ◽

10.3390/f12030284 ◽

2021 ◽

Vol 12 (3) ◽

pp. 284

Author(s):

Ebru Bilici

Keyword(s):

Weibull Distribution ◽

Shape Parameter ◽

B Value ◽

Productivity Analysis ◽

Volume Data ◽

Estimation Model ◽

Distribution Method ◽

Timber Volume ◽

C Value ◽

The Right

With the advancement of technology in forestry, the utilization of advanced machines in forest operations has been increasing in the last decades. Due to their high operating costs, it is crucial to select the right machinery, which is mostly done by using productivity analysis. In this study, a productivity estimation model was developed in order to determine the timber volume cut per unit time for a feller-buncher. The Weibull distribution method was used to develop the productivity model. In the study, the model of the theoretical (estimated) volume distributions obtained with the Weibull probability density function was generated. It was found that the c value was 1.96 and the b value was 0.58 (i.e., b is the scale parameter, and c is the shape parameter). The model indicated that the frequency of the volume data had moved away from 0 as the shape parameter of the Weibull distribution increased. Thus, it was revealed that the shape parameter gives preliminary information about the distribution of the volume frequency. The consistency of the measured timber volume with the estimated timber volume strongly indicated that this approach can be effectively used by decision makers as a key tool to predict the productivity of a feller-buncher used in harvesting operations.

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