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1.
J Environ Manage ; 351: 119684, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38056324

RESUMO

The continuous increase in building energy consumption, and the increasing types and quantities of solid waste have seriously hindered the rapid development of social economy. Therefore, reducing building energy consumption while realizing the recycling of waste has become the mainstream topic of environmental protection construction in the new era. An alkali-activated ultra-light foamed insulation material (AFIM) for building walls was prepared using EPS particles as lightweight aggregates. The effects of EPS dosage, particle size, and gradation on the compressive strength, dry density, thermal conductivity, and volumetric water absorption of AFIM were studied. The results showed that while ensuring good mechanical properties of AFIM, EPS particles can significantly reduce the dry density, thermal conductivity, and volumetric water absorption of AFIM. Excitingly, the optimal thermal conductivity and dry density of AFIM were 0.0408 W/(m·K) and 127.03 kg/m3, respectively. The microscopic morphology results showed that there was good compatibility between EPS particles and AFIM slurry, and the interface transition zone (ITZ) between them was dense and without obvious cracks. In addition, the feasibility of AFIM was evaluated from four aspects: performance, energy consumption, carbon emissions, and life cycle cost (LCC). It was encouraged that the performance of AFIM was comparable to that of traditional insulation materials, and showed significant advantages in energy conservation, emission reduction and economic benefits compared to traditional insulatin materials.


Assuntos
Materiais de Construção , Resíduos Sólidos , Estudos de Viabilidade , Reciclagem , Água
2.
Ecotoxicol Environ Saf ; 233: 113324, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35193030

RESUMO

This work investigated the distribution and chemical fingerprints of 24 metals in particulate matter (PM) deposited in nonoccupational human lungs. Metals in the pulmonary PM can be grouped by the mean concentration as > 5 × 103 µg/g (Al/Fe/Ca/Mg/Zn), 1-5 × 103 µg/g (Ti/Ba/Pb/Mn), 0.2-1 × 103 µg/g (Cu/Cr/As/V) and < 100 µg/g (Ni/Sn/Cd/Sb). Three parameters (LFL, LR, EFP) were defined to predict different metal leaching behaviors. The leaching factor (LFL) of metals was 10-60 for Pb/Sb/Cd/Co/Cu and decreased to 1-2 for Ni/Cr/Mg/Al/Fe. Metals showed a divergent extent of lung retention (LR), including high retention (LR>10, Al/Cd/Cr/Ba/Ni/Ti/Sn/V/Sb), moderate retention (2 

Assuntos
Metais Pesados , Material Particulado , Monitoramento Ambiental , Humanos , Pulmão/química , Metais/análise , Metais Pesados/análise , Material Particulado/análise
3.
Environ Geochem Health ; 44(3): 979-991, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34131853

RESUMO

The enrichment of heavy metals in air-borne particulate matters poses a great threat to health. In order to understand the mineralogical characteristics and sources of heavy metals in atmospheric particulate matter in coal mining cities, PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 µm), PM10 (particulate matter with an aerodynamic diameter less than 10 µm) and TSP (total suspended particulates) were sampled from Huainan city, China in December 2016 and May 2017. The contents of heavy metals in TSP are the highest, while those in PM2.5 are the lowest. Zn, Mn, and Pb are the main components of heavy metals in Huainan atmospheric particulates. Straw burning activities may result in relatively higher atmospheric particulate matter content in summer than that in winter. The proportion of mineral particles in the studied particulate matters was the highest (40.79%), followed by soot aggregates (35.55%) and coal fly ash (19.74%). The results of energy spectrum analysis show that the main component of soot aggregates is C, and other contents are contributed by elements such as O and Si. Coal fly ash mainly contains C, O, Si, and a small amount of Al and Na. As, Cd, and Hg are the most easily enriched heavy metals. Industrial emissions, traffic discharges, coal combustion and dust emissions were found to be the main sources of heavy metals in atmospheric particulates.


Assuntos
Poluentes Atmosféricos , Metais Pesados , Poluentes Atmosféricos/análise , China , Cidades , Monitoramento Ambiental , Metais Pesados/análise , Material Particulado/análise , Estações do Ano
4.
Biol Pharm Bull ; 41(4): 510-523, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29607923

RESUMO

Microscopic examination of crude drug components has been the traditional method to identify the origin of biological materials. For the identification of components in a given mixture via microscopy, standard reference photographs of fragments derived from different organs and tissues of individual species are required. In addition to these reference photographs, a highly observant eye is needed to compare the morphological characteristics observed under the microscope with those of the references and to then identify the origin of the materials. Therefore, if other indexes are available to be coupled with microscope examination, the accuracy of identification would be significantly improved. Here, we prepared standard reference photographs for microscopic examination to identify powdered and fragmented materials in the crude drug "Quanxie" derived from individual organs of dried scorpion (Buthus martensii KARSCH). Since a remarkable characteristic of scorpion bodies is that they fluoresce under UV light, two methods to identify "Quanxie" were established, including fluorescence fingerprint analysis and microscopic fluorescent luminance imaging analysis. In the former, at least 0.1 g of powered materials was used, which could be recovered after the measurement, and in the latter, only small amounts of powders were used for microscopic examinations. Both methods could distinguish powders of "Quanxie" from those of other micro-morphologically similar crude drugs, namely, "Chantui," "Sangpiaoxiao," and "Jiangcan." The combination of these methods should improve the swiftness and accuracy of "Quanxie" identification.


Assuntos
Misturas Complexas/análise , Escorpiões , Animais , Fluorescência , Microscopia de Fluorescência , Fenótipo , Pós , Escorpiões/anatomia & histologia
5.
Pak J Med Sci ; 32(6): 1522-1527, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28083057

RESUMO

OBJECTIVE: To evaluate the effects of diet control and Metformin on placental morphology in gestational diabetes mellitus (GDM). METHODS: After written informed consent 62 GDMs were enrolled. According to WHO criteria, 30 cases of GDMs with blood sugar level <130 mg/dl, were assigned Group B (2000-2500Kcal/day and 30 minute walk thrice weekly were kept on diet control and 32 cases of GDM with blood sugar level >130 mg/dl, assigned Group C were kept on diet with tablet Metformin,(500mg TDS) Finally 25 normal pregnant females were kept in Group A as control. After delivery placentae were preserved and evaluated for morphology. RESULTS: Heavy placentae with abundant villous immaturity, chorangiosis and syncytial knots in group B and fibrinoid necrosis and calcification in group C were seen. In group B versus A placental and cord width while in Group C versus A only cord width in gross morphology showed significant results. In group B versus A villous immaturity, chorangiosis, infarction and syncytial knots in light microscopy were present; similarly in B versus C placental width, chorangiosis and syncytial knots showed significant results, while in C versus A results were non-significant. CONCLUSION: Metformin produced beneficial effects on placental morphology being comparable to normal control in contrast to diet group.

6.
Polymers (Basel) ; 16(3)2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38337273

RESUMO

This study examines a versatile polymer known as polysurfactant, which is synthesized by co-polymerizing flexible acrylamide and sodium acrylate hydrocarbon chain. The polymer serves as a backbone and possesses active functional groups. Notably, the polysurfactant exhibits superior plugging and flooding abilities compared to conventional polymers. The primary objective of this paper is to investigate the properties and oil displacement characteristics of the polysurfactant through indoor physical simulation experiments. The results demonstrate that the multi-branched structure of the polysurfactant enhances its ability to associate, leading to the formation of a unique spatial network structure. The inclusion of multi-branched structures notably amplifies the association effect. The critical concentration for the association is estimated to be around 800 mg/L, at which juncture the polysurfactant exhibits a viscosity retention rate surpassing 90% subsequent to shearing. Furthermore, this spatial network structure exhibits self-recovery capabilities after experiencing shear failure and displaying strong viscosity and shear resistance. In addition, the concentration of the polysurfactant can control the hydrodynamic feature size, which shows its adaptability in regulation and oil-repelling functions at reservoir permeabilities ranging from 500 to 2000 × 10-3 µm2 with resistance coefficients ranging from 108 to 320. During the microscopic oil displacement process, the polysurfactant exerts a significant impact on mobility control, while the elastic pull clearly demonstrates a commendable viscoelastic oil displacement effect. The polysurfactant exhibits a specific degree of emulsification capability towards crude oil, leading to the emulsion exhibiting typical pseudoplastic fluid characteristics. The utilization of emulsification transportation and emulsification blockage contributes to the enhancement of oil recovery. As a result, the polysurfactant exhibits multifaceted capabilities, encompassing profile control, flooding, and plugging, owing to its unique structural characteristics. Through the implementation of a field test focused on flooding in the Daqing Oilfield, a significant enhancement in the recovery rate of 10.85% is observed, accompanied by a favorable input-output ratio of 1:3.86, thereby generating significant economic advantages.

7.
Polymers (Basel) ; 16(17)2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39274150

RESUMO

The vibration pretreatment-microwave curing process can achieve high-quality molding under low-pressure conditions and is widely used in the curing of resin-based composites. This study investigated the effects of the vibration pretreatment process parameters on the void content and the fiber weight fraction of T700/TRE231; specifically, their influence on the interlaminar shear strength and impact strength of the composite. Initially, an orthogonal experimental design was employed with interlaminar shear strength as the optimization target, where vibration acceleration was determined as the primary factor and dwell time as the secondary factor. Concurrently, thermogravimetric analysis (TGA) was performed based on process parameters that corresponded to the extremum of interlaminar shear strength, revealing a 2.17% difference in fiber weight fraction among specimens with varying parameters, indicating a minimal effect of fiber weight fraction on mechanical properties. Optical digital microscope (ODM) analysis identified interlaminar large-size voids in specimens treated with vibration energy of 5 g and 15 g, while specimens subjected to a vibration energy of 10 g exhibited numerous small-sized voids within layers, suggesting that vibration acceleration influences void escape pathways. Finally, impact testing revealed the effect of the vibration pretreatment process parameters on the impact strength, implying a positive correlation between interlaminar shear strength and impact strength.

8.
Materials (Basel) ; 17(7)2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38612071

RESUMO

To promote the resource utilization of steel slag and improve the production process of steel slag in steelmaking plants, this research studied the characteristics of three different processed steel slags from four steelmaking plants. The physical and mechanical characteristics and volume stability of steel slags were analyzed through density, water absorption, and expansion tests. The main mineral phases, morphological characteristics, and thermal stability of the original steel slag and the steel slag after the expansion test are analyzed with X-ray diffractometer (XRD), scanning electron microscope (SEM), and thermogravimetric analysis (TG) tests. The results show that the composition of steel slag produced by different processes is similar. The main active substances of other processed steel slags are dicalcium silicate (C2S), tricalcium silicate (C3S), CaO, and MgO. After the expansion test, the main chemical products of steel slag are CaCO3, MgCO3, and calcium silicate hydrate (C-S-H). Noticeable mineral crystals appeared on the surface of the steel slag after the expansion test, presenting tetrahedral or cigar-like protrusions. The drum slag had the highest density and water stability. The drum slag had the lowest porosity and the densest microstructure surface, compared with steel slags that other methods produce. The thermal stability of steel slag treated by the hot splashing method was relatively higher than that of steel slag treated by the other two methods.

9.
Materials (Basel) ; 16(19)2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37834693

RESUMO

In order to advance the utilization rate of multi-source solid wastes in the Ningxia region of China, 16 groups of pavement base mixtures were designed with cement and fly ash (FA) as binders, steel slag (SS), silicon manganese slag (SMS), and recycled crushed stone (RCS) as composite aggregates. The evolution laws of mechanical and frost resistance properties of the mixture were investigated by unconfined compressive strength (UCS), indirect tensile strength (ITS), freeze-thaw (FT), and ultrasonic detection tests. Then, the strength formation mechanisms were revealed by microscopic characterization technology. The mathematical models between UCS-ITS, UCS-ultrasonic amplitude, FT cycles-UCS damage, and frost resistance coefficient-relative dynamic elastic modulus Er were established. The results show that cement content and curing age exhibited a positive effect on the mechanical strength and frost resistance of the mixture. When the replacement rate of SS was 60%, the mechanical strength and frost resistance were preferable. The R2 of the strength relationship models constructed was greater than 0.9, indicating high fitting accuracy. With the extension of the curing age, the cementitious products such as C-S-H (hydrated calcium silicate) and AFt (ettringite) developed entirely, and they were interlocked and cemented with each other, resulting in the micro-morphology developed from the three-dimensional network structure to the dense system. The macroscopic behavior incarnated that the mechanical strength and frost resistance of the mixture were significantly enhanced.

10.
Polymers (Basel) ; 15(5)2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36904366

RESUMO

Dyed wood is prone to photoaging when exposed to UV irradiation which decreases its decorative effect and service life. Holocellulose, as the main component of dyed wood, has a photodegradation behavior which is still unclear. To investigate the effect of UV irradiation on chemical structure and microscopic morphology changes of dyed wood holocellulose, Maple birch (Betulacostata Trautv) dyed wood and holocellulose were exposed to UV accelerated aging treatment; the photoresponsivity includes crystallization, chemical structure, thermal stability, and microstructure were studied. Results showed that UV radiation has no significant effect on the lattice structure of dyed wood fibers. The wood crystal zone diffraction 2θ and layer spacing was basically unchanged. With the UV radiation time extension, the relative crystallinity of dyed wood and holocellulose showed a trend of increasing first and then decreasing, but the overall change was not significant. The relative crystallinity change range of the dyed wood was not more than 3%, and the dyed holocellulose was not more than 5%. UV radiation caused the molecular chain chemical bond in the non-crystalline region of dyed holocellulose to break, the fiber underwent photooxidation degradation, and the surface photoetching feature was prominent. Wood fiber morphology was damaged and destroyed, finally leading to the degradation and corrosion of the dyed wood. Studying the photodegradation of holocellulose is helpful to understand the photochromic mechanism of dyed wood, and, further, to improve its weather resistance.

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