Economic and financial impact of the COVID-19 pandemic in South Asia

Environmental Science and Pollution Research - The world is facing a COVID-19 pandemic outbreak with an unprecedented and enormous impact on the lives of humankind. The economic engine has suffered...     

Escherichia coli,Species C Human Adenovirus,and Enterovirus in Water Samples Consumed in Rural Areas of Goiás,Brazil

Food and Environmental Virology - Rural environments lack basic sanitation services. Facilities for obtaining water and disposing sewage are often under the initiative of each resident, who may not...     

Investigation of gamma ray absorption levels of composites produced from copper mine tailings,fly ash,and brick dust

To date, heavyweight concretes have been produced from various heavy aggregates as radiation insulation materials, and their gamma ray absorption levels have been investigated. Many of the studies have used heavy aggregates instead of cement or coarse aggregates from composite material components. The present study prepared lightweight concretes using copper mine tailings, clay brick dust, and fly ash instead of fine aggregates. Some mechanical tests (density, compressive strength, and ultrasonic pulse velocity) were performed on composite blocks with dimensions of 5*5*5 cm, and radiation interaction parameters [linear absorption coefficient (cm⁻¹), mass attenuation coefficient (cm²/gr), HVL (half-value layer) (cm), MFP (cm), and permeability (%)] were measured. Radiation interaction parameters were obtained using a HPGe gamma detector. Radiation measurements were performed at five different photon energies: 583 keV (¹³³Ba), 609 keV (¹³³Ba), 662 keV (¹³⁷Cs), 911 keV (133^Ba), 1173 keV (⁶⁰Co), and 1332 keV (⁶⁰Co). Additionally, the compressive strength and UPV values of composite materials were associated with their gamma ray permeability. Tests revealed that samples with the addition of copper mine tailings yielded the best energy absorption at all energy levels and that absorption decreased as the energy level increased. For example, with the increasing of the energy level, mass attenuation coefficients decreased. The highest mass attenuation coefficients were obtained as 0.128 cm²/g at an energy level of 583 keV in composites produced from copper mine tailings. On the other hand, it was measured at the same energy level as 0.069 cm²/g (a 46% decrease) in the composites produced with fly ash. In addition, it was observed that fly ash used as a fine aggregate did not have a significant effect on mass attenuation coefficient and could be used as a gamma shield if the material thickness was increased to an average of 14 cm. This study revealed that tailings materials could be used as radiation shields. This study also demonstrated that not using heavy aggregates and producing lightweight concrete in radiation shield production significantly reduced shield production cost.

     

Chronic exposure to lead acetate promotes changes in the alveolar bone of rats: microstructural and physical–chemical characterization

Environmental Science and Pollution Research - There are a few data relating to the effects of lead (Pb) exposure on the alveolar bone, which has very distinct morphophysiological characteristics...     

Characterization and recycling of lithium nickel manganese cobalt oxide type spent mobile phone batteries based on mineral processing technology

Journal of Material Cycles and Waste Management - The unprecedented increase in mobile phone spent lithium-ion batteries (LIBs) in recent times has become a major concern for the global community....     

Annealing Effect on Pla/Eva Blends Performance

Journal of Polymers and the Environment - PLA has aroused industrial and scientific interest in recent years, mainly due to its biodegradable character. However, PLA is brittle and displays low...