Associations between Parents’ Perceived Air Quality in Homes and Health among Children in Nanjing, China

<div><p>The increasing prevalence of respiratory diseases in Chinese children has focused attention on indoor environmental quality. We investigated associations between perceived air quality in domestic environments and children’s allergic diseases with a questionnaire survey study. A total of 4017 children aged 1–8 years old from 23 kindergartens in urban, suburban and industrial areas in Nanjing were randomly recruited for this study. Parents’ perceived odors, including stuffy odor, unpleasant odor, pungent odor, moldy odor, humid air and dry air were found to be associated with asthma, wheeze, dry cough and rhinitis (<i>P</i> < 0.05). Both perceived dry and humid air were found to be positively associated with dampness indices, and we present evidence that the sensation of dryness may not be due to the actual indoor relative humidity, but rather to indoor air irritants. Parents’ perception of odors and relative humidity may be indicators of environment pollutants, which are likely the real factors associated with children’s allergic diseases.</p></div

Associations between children’s allergic diseases and O&H-score.

<p>Associations between children’s allergic diseases and O&H-score.</p

Odors and humidity perceptions, stratified for dwelling locations of surveyed homes and construction year of the buildings.

<p>Odors and humidity perceptions, stratified for dwelling locations of surveyed homes and construction year of the buildings.</p

Hydrogen-Coverage-Dependent Stark Effect in Bilayer Graphene and Graphene/BN Nanofilms

Hydrogenation and electric field are used to tailor the electronic structures of hybrid graphene/hexagonal boron nitride (Gr/BN) and bilayer graphene (Gr/Gr). Without hydrogen adsorption, the electronic structure of Gr/BN is only slightly affected by the electric field, but energy gaps are induced in Gr/Gr because of the breaking of inversion symmetry. Under partial hydrogenation conditions, more interlayer bonds tend to form in Gr/BN than that in Gr/Gr because of the inherent Coulomb attraction, and a band gap is created in Gr/BN even at low hydrogen coverage. The electronic structures of partially hydrogenated Gr/BN and Gr/Gr are both rather insensitive to the electric fields. Under full hydrogenation conditions, Gr/BN and Gr/Gr evolve into diamond-like nanofilms: Gr/BN-BC (interlayer B–C bonding) and Gr/Gr-CC (C–C bonding). Because of the interface-dipole-induced electric field, the band gap of Gr/BN-BC is rather small compared to that of the Gr/Gr-CC. Depending on the direction of the external electric field, the band gap of Gr/BN-BC is linearly increased or decreased, whereas that of Gr/Gr-CC is only decreased. These electric-field-induced band gap modulations in Gr/BN and Gr/Gr as well as their hydrogenation derivatives are results of the Stark effect; they are dependent on the hydrogen coverage and can be understood in terms of the charge distribution of the valence-band maximum and conduction-band minimum

The percentage of dampness indices for different construction year of the buildings.

<p>The percentage of dampness indices for different construction year of the buildings.</p

Number and prevalence of children allergic diseases, and pneumonia in homes with/without odors.

<p>(Confidence Intervals and Proportions in parentheses).</p

Association between allergic diseases and perception of odors and humidity.

<p>Association between allergic diseases and perception of odors and humidity.</p

Proportions of perceived odors and the sensation of humidity, stratified according to guardians’ gender and family history of asthma or allergies.

<p>Proportions of perceived odors and the sensation of humidity, stratified according to guardians’ gender and family history of asthma or allergies.</p

Lithium Carbonate Recovery from Cathode Scrap of Spent Lithium-Ion Battery: A Closed-Loop Process

A closed-loop process to recover lithium carbonate from cathode scrap of lithium-ion battery (LIB) is developed. Lithium could be selectively leached into solution using formic acid while aluminum remained as the metallic form, and most of the other metals from the cathode scrap could be precipitated out. This phenomenon clearly demonstrates that formic acid can be used for lithium recovery from cathode scrap, as both leaching and separation reagent. By investigating the effects of different parameters including temperature, formic acid concentration, H₂O₂ amount, and solid to liquid ratio, the leaching rate of Li can reach 99.93% with minor Al loss into the solution. Subsequently, the leaching kinetics was evaluated and the controlling step as well as the apparent activation energy could be determined. After further separation of the remaining Ni, Co, and Mn from the leachate, Li₂CO₃ with the purity of 99.90% could be obtained. The final solution after lithium carbonate extraction can be further processed for sodium formate preparation, and Ni, Co, and Mn precipitates are ready for precursor preparation for cathode materials. As a result, the global recovery rates of Al, Li, Ni, Co, and Mn in this process were found to be 95.46%, 98.22%, 99.96%, 99.96%, and 99.95% respectively, achieving effective resources recycling from cathode scrap of spent LIB

A Closed-Loop Process for Selective Metal Recovery from Spent Lithium Iron Phosphate Batteries through Mechanochemical Activation

With the increasing consumption of lithium ion batteries (LIBs) in electric and electronic products, the recycling of spent LIBs has drawn significant attention due to their high potential of environmental impacts and waste of valuable resources. Among different types of spent LIBs, the difficulties for recycling spent LiFePO₄ batteries rest on their relatively low extraction efficiency and recycling selectivity in which secondary waste is frequently generated. In this research, mechanochemical activation was developed to selectively recycle Fe and Li from cathode scrap of spent LiFePO₄ batteries. By mechanochemical activation pretreatment and the diluted H₃PO₄ leaching solution, the leaching efficiency of Fe and Li can be significantly improved to be 97.67% and 94.29%, respectively. To understand the Fe and Li extraction process and the mechanochemical activation mechanisms, the effects of various parameters during Fe and Li recovery were comprehensively investigated, including activation time, cathode powder to additive mass ratio, acid concentration, the liquid-to-solid ratio, and leaching time. Subsequently, the metal ions after leaching can be recovered by selective precipitation. In the whole process, about 93.05% Fe and 82.55% Li could be recovered as FePO₄·2H₂O and Li₃PO₄, achieving selective recycling of metals for efficient use of resources from spent lithium ion batteries