Do latitude and ozone concentration predict Covid-2019 cases in 34 countries?

In this paper, I used multivariate linear regression analysis to determine if latitude and ozone concentration predict Covid-2019 cases in 34 countries worldwide. Data pertaining to Covid-2019 cases were extracted from Worldometer. Ozone concentration levels were taken from the open-access database of World Ozone and Ultraviolet Radiation Data Centre (WOUDC). Latitude of specific area where measurement took place was also provided in the database. Preliminary Kendall rank correlation test revealed that Covid-2019 incidence was positively and significantly related to ozone concentration; however, incidence was not significantly related to latitude. Using multivariate linear regression, a statistically significant link between ozone concentration and Covid-2019 incidence in 34 countries was established; however, I found no statistical association between latitude and Covid-2019 incidence refuting previous claims. Prompt health actions should be developed for areas with high ozone concentration in the present and possibly, future outbreaks; however, extensive laboratory analysis should be conducted to further confirm the findings of the study. Nevertheless, the results of this study could serve as a basis for further clinical and large-scale studies.

Assessment of Physiological, Biochemical and Yield Attributes of Rice Cultivars under Elevated Ozone Stress

The present study aimed to assess the response of 15 rice cultivars exposed to elevated ozone stress. The plants were exposed to 100 ppb ozone (10:00– 17:00 h) for 30 days at the reproductive stage. Elevated ozone significantly alters the physiological, biochemical, growth and yield traits of all test rice cultivars. Elevated ozone exposure significantly decreased photosynthetic rate maximally in MDU5 (42.90%) and TRY(R)2 showed maximum reduction in stomatal conductance (42.39%) and chlorophyll content (41.22%). In terms of yield traits, a decrease in tiller number, number of effective tillers, number of filled spikelets per panicle and 1000 grain weight over the control were also observed. The multivariate analysis with a total variance of 58.86% categorized the 15 rice cultivars into ozone sensitive (TRY(R) 2, ASD16, ADT(R)45 and MDU5), moderately ozone sensitive (ASD18, ADT43, Rice MDU6, ADT36 and ADT37), moderately ozone tolerant (ADT(R)48 CO47 and Rice CO51) and ozone tolerant (Rice TPS5, Anna(R)4 and PMK(R)3) under 100 ppb ozone. The present results revealed that the ozone tolerant rice cultivars would be recommended to cultivate in the regions experiencing high ozone concentration.

Improved Ozonation Efficiency for Polymerization Mother Liquid from Polyvinyl Chloride Production Using Tandem Reactors

Polymerization mother liquid (PML) is one of the main sources of wastewater in the chlor-alkali industry. The effective degradation of the PML produced in PVC polymerization using three or five ozone reactors in tandem was designed with a focus on improving the ozonation efficiency. The ozonation efficiency of the tandem reactors for the degradation of PML, along with the effect of ozone concentration, the number of reactors utilized in series, and the reaction time on the chemical oxygen demand (COD) removal were investigated in detail. The results showed that the COD removal increased as the ozone concentration was increased from 10.6 to 60 mg·L−1, achieving 66.4% COD removal at ozone concentration of 80.6 mg·L−1. However, when the ozone concentration was increased from 60 mg·L−1 to 80 mg·L−1, the COD removal only increased very little. The COD decreased with increasing ozone concentration. During the initial degradation period, the degradation rate was the highest at both low and high ozone concentrations. The degradation rate decreased with reaction time. The rate at a low ozone concentration decreased more significantly than at high ozone concentration. Although high ozone concentration is desirable for COD removal and degradation rate, the utilization efficiency of ozone decreased with increasing ozone concentration. The ozone utilization efficiency of the five-reactor device was three times higher than that of three tandem reactors, demonstrating that ozonation utilization efficiency can be improved by increasing the number of tandem reactors. Ozonation in tandem reactors is a promising approach for PML treatment.

DIAL measurement of lower tropospheric ozone over Saga (33.24° N, 130.29° E), Japan, and comparison with a chemsitry-climate model

We have improved an ozone DIfferential Absorption Lidar (DIAL) system, originally developed in March 2010. The improved DIAL system consists of a Nd:YAG laser and a 2 m Raman cell filled with 8.1 × 105 Pa of CO2 gas which generate four Stokes lines (276, 287, 299, and 312 nm) of stimulated Raman scattering, and two receiving telescopes with diameters of 49 and 10 cm. Using this system, 44 ozone profiles were observed in the 1–6 km altitude range over Saga (33.24° N, 130.29° E) in 2012. High ozone concentration layers were observed at around 2 km altitude during April and May. Ozone column amounts within the 1–6 km altitude range were almost constant from January to March, and increased from late April to July. From mid-July through August, ozone column amounts decreased greatly because of exchanges of continental and maritime air masses. Then in mid-September they increased again within 1–6 km, and subsequently decreased slowly, becoming almost constant by December. The Meteorological Research Institute's Chemistry-Climate Model version 2 (MRI-CCM2) successfully predicted most of these ozone variations with the following exceptions. MRI-CCM2 could not predict the high ozone-mixing ratios measured at around 2 km altitude on 5 May and 11 May, possibly in part because emissions were assumed in the model to be constant (climatological data were used). Ozone-mixing ratios predicted by MRI-CCM2 were low in the 2–6 km range on 7 July and high in the 1–4 km range on 19 July compared with those measured by DIAL.

INVESTIGATION OF THE OZONE POLLUTION LEVEL IN SOME PHOTOCOPY ENTERPRISES AND METHOD OF TREATMENT

This study measured the ozone pollution level in 4 photocopy shops in Ho Chi Minh City during 2 months, from March to April 2010. The result indicated that ozone concentration increases rapidly when the photocopiers start. The highest concentration of ozone is seemed to be from 11h30 to 16h30 every day. The concentration at the entrance is lower than at the center of the photocopy enterprise. Besides, this study also evaluated the ozone absorption rates of Epipremnum Aureum plant by a hermetic model. The result showed that the absorption rates increase by time, reach to 78.9% after 3 days. Consequently, we can use this plant to reduce the high ozone concentration in the photocopy shops.

Coating Technique’s Application in the Improvement of Mechanical Behavior of Polyester Textile in Corrosive Environment

Polyester textiles usually have excellent mechanical properties. However, their mechanical behaviors under extreme conditions such as in the environment with high ozone concentration usually decay after a certain time period. Aiming at increasing the mechanical behavior of commercial polyester textiles under extreme conditions, a PET thin film coated with pure aluminum (Al) on its surface has been introduced as the top layer of the fabricated material with polyester textile as the middle layer. Main purpose of the study is to evaluate the role of aluminum thin film on the surface in improving the mechanical behavior of the polyester textiles after they have been exposed in the environment with extremely high concentration of ozone gas.