Estimating stray dog populations with the regression method versus Beck’s method: a comparison

Statistical procedures for wildlife population estimation have been greatly improved since the last decade. For estimation of stray dog population size, however, the simple methods recommended by the 1990 WHO/WSPA guidelines seem to remain the popular favorites among researchers. Although the methods are very easy to use, their usefulness relies heavily on certain assumptions that are generally unrealistic. Using simulation studies, we conclude that Beck’s method, one of the estimators recommended by the guidelines, performs fairly well and can be safely used to get a quick population estimate, as long as the underlying assumptions are not severely violated.     

Surface characterization of acid-oxidized multi-walled carbon nanotubes

Multi-walled carbon nanotubes (MWNTs) oxidized with sulfuric acid, nitric acid, and the mixture of sulfuric and nitric acids were characterized by thermogravimetric analysis (TGA), Raman spectroscopy, elemental analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. The TGA data showed that the MWNTs were more resistant to oxidation than C₆₀ or activated carbon fibers. Catalyst particles could be removed by the oxidants containing sulfuric acid, and thus indicative of the tip opening of MWNTs. The sulfuric acid had a propensity to create defect sites and introduce the surface oxides at those defects that already exist or be newly generated on MWNTs. However, the acid mixture could open the caps of MWNTs but preserve the structure homogeneity. The treatment with nitric acid gave rise to the highest bulk oxygen content in MWNTs, while the most abundant surface oxides were provided by sulfuric acid oxidation. In addition, nitric acid exhibited the best ability to transform the phenolic groups into carboxyl groups.     

Technology review and evaluation of different chemical oxidation conditions on treatability of PFAS

Per‐ and polyfluoroalkyl substances (PFAS) are a class of stable compounds widely used in diverse applications. These emerging contaminants have unique properties due to carbon–fluorine (C–F) bonds, which are some of the strongest bonds in chemistry. High energy is required to break C–F bonds, which results in this class of compounds being recalcitrant to many degradation processes. Many technologies studied that have shown treatment effectiveness for PFAS cannot be implemented in situ. Chemical oxidation is a demonstrated remediation technology for in situ treatment of a wide range of organic environmental contaminants. An overview of relevant literature is presented, summarizing the use of single or combined reagent chemical oxidation processes that offer insight into oxidation–reduction chemistries potentially capable of PFAS degradation. Based on the observations and results of these studies, bench‐scale treatability tests were designed and performed to establish optimal conditions for the formation of specific free radical species, including superoxide and sulfate radicals, via various combinations of oxidants, catalysts, pH buffers, and heat to assess PFAS treatment by chemical oxidants. The study also suggests the possible abiotic transformations of some PFAS when chemical oxidation is or was used for treatment of primary organic contaminants (e.g., petroleum or chlorinated organic compounds) at a site. The bench‐scale tests utilized field‐collected samples from a firefighter training area. Much of the available data related to chemical oxidation of PFAS has only been reported for one or both of the two more commonly discussed PFAS (perfluorooctane sulfonic acid and/or perfluorooctanoic acid). In contrast, this treatability study evaluates oxidation of a diverse list of PFAS analytes. The results of this study and published literature conclude that heat‐activated persulfate is the oxidation method with the best degradation of PFAS. Limited reduction of reported PFAS concentrations in this study was observed in many oxidation reactors; however, unknown mass of PFAS (such as precursors of perfluoroalkyl acids) that cannot be identified in a field collected sample complicated quantification of how much oxidative destruction of PFAS actually occurred.     

How can sports entrepreneurs achieve their corporate sustainable development goals under the COVID-19 epidemic?

Environmental Science and Pollution Research - The present study aimed to explore the opportunities for the sustainable development of professional sports enterprises and events from the...     

Characteristic Study of Ambient Air Total Gaseous Mercury (TGM) Concentrations During Rainy and Non-Rainy Periods at a Traffic Site in Taiwan

This investigation studied the concentrations of ambient air total gaseous mercury (TGM) during the rainy periods at the Hung-Kuang traffic sampling site in central Taiwan from May 26 to June 16, 2014. The results were compared with those of a previous study for ambient air TGM during non-rainy daytime and nighttime periods at the Hung-Kuang traffic sampling site, which was conducted during March 21 to July 20, 2012. The observed mean concentration of ambient air TGM was 1.16 ng/m³ during the rainy periods at the Hung-Kuang traffic sampling site. The mean ambient air TGM concentrations were higher in the non-rainy sampling period in daytime than in the rainy sampling period from this study. The mean ratio of non-rainy sampling period in daytime to that of rainy sampling period for ambient air TGM were 3.15. Furthermore, the mean ambient air TGM concentrations were higher in the non-rainy sampling period in nighttime in than in the rainy sampling period for this study. The mean rations for non-rainy sampling period in nighttime to that of the rainy sampling period for ambient air TGM were 2.70. The results obtained in this study also revealed that the ambient air TGM concentrations during the rainy period had the lowest concentrations when compared with the other sampling sites in other world regions.     

Temperature and nutrients are significant drivers of seasonal shift in phytoplankton community from a drinking water reservoir,subtropical China

Reservoirs are an important source of water supply in many densely populated areas in southeast China. Phytoplankton plays an important role in maintaining the structure and function of these reservoir ecosystems. Understanding of seasonal succession in phytoplankton communities and its driving factors is essential for effective water quality management in drinking-water reservoirs. In this study, water samples were collected monthly at the surface layers of riverine, transitional, and lacustrine zones from May 2010 to April 2011 in Tingxi Reservoir, southeast China. The phytoplankton showed distinct seasonal shifts in community structure at both taxonomic and functional levels. Cyanophyta was the dominant group in summer, especially species of Raphidiopsis in May and Aphanizomenon in June, and cyanobacterial dominance was promoted by both warmer conditions and excessive nutrients loading. Cyanophyta was gradually replaced by Cryptophyta (e.g., Chroomonas caudata) in abundance and by Bacillariophyta (Fragilaria sp. or Synedra sp. and Melosira sp.) in biomass with decreasing temperature. It appeared that seasonal shifts in phytoplankton composition were closely related to climate, nutrient status, and hydrology in this reservoir. Our partial RDA results clearly showed that water temperature and nutrients (TN and TP) were the most critical factors driving phytoplankton community shift in the abundance and biomass data, respectively. Further, with the global warming, cyanobacterial blooms may increase in distribution, duration, and intensity. In our study, the abundance and biomass of cyanobacteria had significant and positive correlations with temperature and phosphorus. Therefore, a stricter limit on nutrient input should be a priority in watershed management to protect drinking water from the effects of cyanobacterial blooms, especially in high-temperature period.     

Spectrophotometric Determination of Atmospheric Acidity by means of the Displacement of the Equilibrium of Acid-Base Indicators

A method is described for determining acidity by means of the spectrophotometric determination of the displacement of the equilibrium of açid-base indicators. The method is simple, sensitive and free of known interferences. There is no dependence on costly or sophisticated equipment and the results obtained are reliable and reproducible.     

An evaluation approach for livable urban environments

This study proposes a method for evaluating livable urban environments using the analytic hierarchy process, a survey of public opinions (n?=?1,075), and gray relational analysis with a pollutant standards index to estimate the weights of weather, air pollution, and environment aspects and each respective factor. This study investigates the positive or negative correlation of these factors and their effects on livable environment. A value of 100 was designated as the perfect living condition. Results show that the weights of weather, air pollution, and environment aspects were 0.288, 0.395, and 0.317, respectively. The weight ranges of three weather factors, five air pollution factors, and ten environmental factors were 0.311-0.358, 0.191-205, and 0.081-0.116, respectively. The monthly livable index of 28 districts in Taichung City and of 20 cities/counties in Taiwan ranged from 81.1 to 92.4 and from 83.1 to 90.8 in different months, respectively, showing that environmental aspect played a key role. These results demonstrate that the proposed method can provide a quantification index of living conditions in each region, thereby establishing the governmental improvement policy firmly. This study also presents a discussion on improvement strategies, especially on the apportionment rate of governmental construction funds for livable urban environments.