Influence of the argon admixture on the reactive oxide species formation inside an atmospheric pressure oxygen plasma jet.

In this work, a new atmospheric pressure plasma generated in a wire-to-multiwire dielectric barrier discharge on pure oxygen is introduced. This special geometry of 13 wires (one central wire and 12 ones on the external tube) is feeding by a radio frequency (RF) power (13.56 MHz, 1 kW) and produces a stable discharge. The capacity of this device to produce oxygen reactive species and the influence of Ar gas mixture (1-3%) on this production are investigated. The main characteristics of this DBD plasma are measured using optical emission spectroscopy techniques. The rotational, vibrational, and excitation temperatures along with the electron density are determined from OH (A2Σ â†’ X2Π) band and the Stark broadening of the hydrogen atomic line at 486.1 nm, respectively. The temporal evolution and spatial distribution of charged and reactive species in this plasma are also numerically studied by a Global scheme and a two-dimension fluid model based on drift-diffusion approximation. A kinetic dominated by electron collisions is obtained for this plasma. The generation and movement of electrons, positive and negative ions in the wire-to-multiwire configuration are analyzed and discussed according to changes the electric field and plasma frequency. It is shown that the density of both charged and reactive species increases by adding a small amount of argon to the oxygen plasma while the electron temperature reduces in this configuration. A high level of agreement is observed between the experimental and simulation results for the electron density and temperature in this DBD plasma.

Disposal Behavior of Used Masks during the COVID-19 Pandemic in the Moroccan Community: Potential Environmental Impact.

The spread of coronavirus disease-2019 (COVID-19) levied on the Moroccan authorities to increase their mask production capacity, which reached up to 12 million facemask units produced per day. This increase in personal protective equipment (PPE) production and consumption is an efficient tool to address the spread of COVID-19. However, this results in more plastic and microplastic debris being added into the land and marine environments, which will harm the ecosystem, wildlife, and public health. Such a situation needs deep individual behavior observation and tracking, as well as an assessment of the potential environmental impact of this new type of waste. For this reason, we assessed the Moroccan population's behavior regarding the use and disposal of facemasks and gloves. An exploratory survey was prepared and shared via social media and email with the population of Rabat-Salé-Kénitra and Casablanca-Settat regions. Additionally, we calculated the estimated number and weight of daily and weekly PPE used and generated by the studied regions. The survey showed that 70% of the respondents threw their discarded masks and gloves in house trash or trash bins after their first use, whereas nearly 30% of respondents admitted that they did not wear masks because they did not leave their homes during the lockdown, while from the 70% of facemask users, more than five million (equivalent to 40,000 kg) of facemasks would be generated and disposed of daily by the community of these regions, which presents 35% of the total engendered facemask waste in Morocco. Accordingly, the environment impact of facemasks showed that the greenhouse gas footprint is about 640 kT CO2 eq./year for the whole of Morocco, while the energy footprint is around 60,000 GWh/year. Furthermore, an urgent multidisciplinary environmental assessment of the potential impact of PPE must be conducted among the 12 Moroccan regions. This study demonstrated the real impact of the COVID-19 PPE on human behavior and the environment and suggests a need for providing new didactic management of facemasks and gloves.

Efficiency of a solar collector system for the public building depending on its location.

Due to a technologic progress, a growth in the renewable energy markets including a high number of manufactures coming to being, the Renewable Energy Sources (RES) are both a tool for mitigating climate changes and investments that can provide direct economic profits and reduce a political or economic dependence resulting from import of fossil fuels. One of the many key solutions toward fulfilling the global increasing demand for energy and reduction of CO2 emissions is applying solar technologies. This paper presents the results of the analysis conducted for a small public office building located in Bialystok (Poland), where solar collectors were considered as the RES for domestic hot water (DHW) system, on the understanding that existing oil boiler would be an additional source. Low values of recommended water consumption in office buildings resulted in a low energy demand. However, concerning a potential of all office governmental buildings in Poland, it would be possible to reduce CO2 emission by 17,248 tonnes. In the comprehensive analysis, the same building in two more locations (Cordoba (Spain) and Kaunas (Lithuania)) was considered using simulation tools delivered within the framework of VIPSKILLS project as well as EnegyPlus software. The results allow to compare the mean monthly efficiency of systems or number of collectors necessary to deliver similar amount of solar energy.

Microwave atmospheric pressure plasma jets for wastewater treatment: Degradation of methylene blue as a model dye.

The degradation of methylene blue in aqueous solution as a model dye using a non thermal microwave (2.45 GHz) plasma jet at atmospheric pressure has been investigated. Argon has been used as feed gas and aqueous solutions with different concentrations of the dye were treated using the effluent from plasma jet in a remote exposure. The removal efficiency increased as the dye concentration decreased from 250 to 5 ppm. Methylene blue degrades after different treatment times, depending on the experimental plasma conditions. Thus, kinetic constants up to 0.177 min-1 were obtained. The higher the Ar flow, the faster the degradation rate. Optical emission spectroscopy (OES) was used to gather information about the species present in the gas phase, specifically excited argon atoms. Argon excited species and hydrogen peroxide play an important role in the degradation of the dye. In fact, the conversion of methylene blue was directly related to the density of argon excited species in the gas phase and the concentration of hydrogen peroxide in the aqueous liquid phase. Values of energy yield at 50% dye conversion of 0.296 g/kWh were achieved. Also, the use of two plasma applicators in parallel has been proven to improve energy efficiency.

Estudio Genético de la raza bovina criolla Casanare de Colombia y su relación con otras razas / Genetic study of the Colombian criollo breed Casanare and its relationship with others breeds

Se estudió la variabilidad genética de la raza Criolla Casanare de Colombia y sus relaciones con poblaciones cruzadas Cebú x Criollo, Cebú puro y Pardo Alpino. Para ello, mediante amplificación por PCR, se han analizado 22 microsatélites en 79 individuos (54 Casanare; 14 Cebú, 8 cruzados y 3 de Pardo Alpino). El número medio de heterocigotos observados y el número medio de alelos por locus fueron mayores en la población Criolla Casanare que en el resto, con valores de 0,72 y próximos a 0,70, respectivamente. Sólo el 3,6 por ciento de la variabilidad observada pudiera ser debida a diferencias entre los distintos grupos raciales (Fst global= 0,03634; P<0,01). La matriz de distancias genéticas mostró más proximidad entre los Criollos Casanare y los cruzados, que entre éstos y los Cebú. Se constató la influencia del Cebú sobre la actual raza Casanare que se encuentra en la actualidad en grave peligro de extinción.

The genetic variability of the Creole Casanare breed of Colombia and its relations with crossed populations Zebu x Creole, pure Cebu and Brown Swiss was studied. For it, by means of PCR amplification, 22 microsatellites have been analyzed in 79 individuals (54 Creole Casanare; 14 Zebu, 8 crossed Zebu x Creole and 3 Brown Swiss). The average of heterozygotos observed and the average number of alleles per locus they were major in the population Creole Casanare that in the rest with values of 0.72 and close to 0.70 respectively. Only 3.6% of the observed variability it could be due to differences between the different racial groups (global FST = 0.03634; P< 0.01). The matrix of genetic distances showed more proximity between the Creole Casanare and the crossed ones that between these and Zebu. The influence of the Zebu on the current breed Casanare was stated, who is at present in serious danger of extinction.