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Due to the COVID-19 pandemic, Bangladesh government took the measure like partial lockdown (PL) and complete lockdown (CL) to curb the spread. These measures gave a chance for environmental restoration. In this study, street dust samples were collected during PL and CL from four main urban land use categories in Dhaka city, such as industrial area (IA), commercial area (CA), public facilities area (PFA), and residential area (RA). Ten potentially toxic elements (Cr, Mn, Zn, Fe, Pb, Cu, Co, Ni, As, and Cd) in fine street dust particles (diameter < 20 μm) were determined following aqua-regia digestion and measured by inductively coupled plasma mass spectrometry (ICP-MS) to evaluate distribution, pollution sources, and potential risks to ecological systems and human health. Results showed that during PL, the concentrations of toxic elements in the dust were higher than that of CL. Cd and Fe were lowest and highest in concentration with 1.56 to 41,970 µg/g and 0.82 to 39,330 µg/g in partial and complete lockdown period respectively. All toxic elements were detected at high levels above background values where Fe with the highest and Cd with lowest concentrations, respectively. By land use, the levels of toxic elements pollution followed IA > PFA > RA > CA. Correlation analysis (CA), principal component analysis (PCA), and hierarchal cluster analysis (HCA) revealed that the sources of these analyzed toxic elements were mainly from anthropogenic which are related to industrial and vehicular or traffic emissions. Enrichment factor (EF), geoaccumulation index (I geo ), contamination factor (CF), and pollution load index (PLI) also suggested that the dust was more polluted during PL. Exposure of toxic elements to human was mainly via skin contact followed by ingestion and inhalation. Hazard quotient (HQ) values were < 1 except for Mn through dermal contact at all sites during partial and complete lockdown, similar to hazard index (HI), while Cr further showed high non-carcinogenic risks to children. Generally, children HI values were about 5-6 times higher than those of adults, suggesting a greater vulnerability of children to the health concerns caused by toxic elements in street dust. Carcinogenic risk (CR) values via ingestion pathway indicated all elements (except Pb) had significant health effect, while CR value by inhalation results showed no significant health effect. Cumulative carcinogenic risk (CCR) value had significant health effect except Pb in all land use categories. CCR values decreased during CL and reached at acceptable limit for most of the cases. This research provides a message to the local governments and environmental authorities to have a complete assessment of toxic elements in the street dust of Dhaka megacity in order to assuring public health safety and ecological sustainability., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Industrial parks, which are characterized as a group of industrial businesses designed to meet the concomitant demands of different organizations within an area, have played an important role in the national development strategies of many countries. Industrial parks have received increasingly more attention over time. Nevertheless, few scholars have visually analyzed global scientific data. This paper quantitatively and visually examines global academic research papers on industrial parks from 1987 to 2016 by using a bibliometric analysis. A total of 1823 papers from Science Citation Index Expanded and Social Sciences Citation Index databases were analyzed. The distributions of authorship, keywords, countries/territories, and institutes were generated. According to data from Science Citation Index Expanded and Social Sciences Citation Index databases, the top five most productive authors (i.e., Geng Y. with 22 articles, Fujita T. with 17, El-Halwagi M.M. with 15, Zhang Y. with 14, and Tan R.R. with 12) have contributed significantly to industrial park research. Papers on industrial park research have mainly been from China, the USA, and Taiwan. The dominant keywords from industrial park research from 1987 to 2016 are "China", "system", "heavy metal", and "eco-industrial park". These keywords will be the hot topics in industrial park research in the future. The research findings can provide a reference for understanding the research development process and trends in analyses in the field of industrial parks. [ABSTRACT FROM AUTHOR]

The aim of this paper is to evaluate water resources use efficiency (WRUE), which focuses on the entire water consumption process by utilizing data envelopment analysis (DEA) and the Malmquist index (MI). A comprehensive analysis of WRUE both on the spatial and temporal scale has been conducted. For the spatial scale, the difference of WRUEs among cities is presented, and the negative factors by analyzing and decomposing relative water resources use efficiency (RWRUE) are examined. Similarly, the dynamic changes of WRUE over time is presented to analyze the temporal scale. Moreover, a real-world case study in Guansu Province, China, from 2003 to 2013 is employed to evaluate the performance of the proposed WRUE analysis. Results show that the decision makers can determine the comprehensive and accurate WRUE and negative factors of WRUE in Gansu. Furthermore, the results provide alternative recommendations to decision makers to plan for efficient use of water resources in different cities. [ABSTRACT FROM AUTHOR]

Water scarcity and aquatic environment deterioration have become increasingly serious problems in Urumqi, China. To alleviate the conflicts arising from competitive water users and retard the environment degradation, an optimization model was developed for regional water resources management under considering the dual total amount of water quantity and pollutant emissions control. Water allocation schemes and guarantee rates that combine diverse water sources and economic activities were obtained through the solutions of the proposed model. The interactions among water allocation schemes, various activities benefits, and pollutant emissions were analyzed synchronously. Policies for industrial structure adjustment and pollutants emission reduction were acquired through the analysis of the results. The modeling results can be valuable for water resources planning and justification of the existing industrial structure. [ABSTRACT FROM AUTHOR]

Shiing-Shen Chern was born on October 26th, 1911 in Jia Xin, Chekiang Province, in China. His father practised law and worked for the government. At Fu Luen Middle School in Tsientsin he first showed his mathematical ability by doing all the exercises in classical English textbooks on algebra and trigonometry, and then went at the age of fifteen to Nankai University — a one-man Department run by Li-Fu Chiang, a student of Coolidge. As a result he studied a great deal of geometry, reading Coolidge, Salmon, Castelnuovo and Staude. He then became a postgraduate in 1930 at Tsinghua University in Beijing (or Peiping as it was then called) and came under the influence of Dan Sun, one of the few mathematicians in China writing research papers. During this period he became seriously interested in Sun's subject, projective differential geometry, and studied in detail the works of Wilhelm Blaschke. It was also at Tsinghua that he met his wife Shih-Ning, the daughter of a professor. After Blaschke paid a visit to Tsinghua in 1932 and lectured on differential-geometric invariants, Chern won a fellowship to study with him in Hamburg for two years. In 1936 he received his DSc there for work on the theory of webs. While in Hamburg, he also attended the lectures of Kähler on what is now called Cartan–Kähler theory, and the following year he spent in Paris studying with Cartan himself. [ABSTRACT FROM AUTHOR]