In casting industries, issue of spent molding sand disposal is the origin of molding sand reclamation. Among from all reclamation concepts the thermal reclamation method is better for no-bake sand system. This study focuses on the evaluation of sand quality by considering physical and chemical characteristics of molding sand, which is reclaimed by thermal reclamation method. Electric fuel and fluidization mechanism is used in thermal reclamation system. Effect of reclamation temperature, soaking period and sand quantity on % reclamability, grain size, ADV and on LOI is investigated. The average grain size, low ADV, low LOI and acceptable % reclamability of thermally reclaimed sand are studied.
Salicylaldehyde imine transition metal catalyst is a kind of olefin polymerization catalyst that is widely used in the coordination of salicylaldehyde imine ligand and pre-transition metal. Salicylaldehyde imine ligands have the characteristic of easily inserting different substituents via organic synthesis. Therefore, the regulation of the polymerization activity, polymerization product, and product distribution can be achieved by changing the steric hindrance effect, the electronic effect, and the number of metal active sites near the catalytic active center. The development status of the transition metal catalyst of salicylaldehyde imide was summarized in this paper. The influence of the ligand structure of the salicylaldehyde imide transition metal catalyst on the catalytic performance, which involved the high selectivity of ethylene trimerization, ethylene/α-olefin, polar monomer copolymerization, ethylene polymerization production, ultra-high molecular weight polyethylene, and many other areas of olefin polymerization, was elaborated, providing references for further study and industrial applications of this catalyst.
The article discusses the essence of integrative geography and its importance for the theory and practice of geographical science. Such areas of integrative geography are characterized, the development of which will further increase the importance of applied geographical science. They include teaching about cultural landscape and historical landscape (part of landscape studies), geoecological expertise and environmental impact assessment (part of geographic ecology), geographic archeology and ecological culture (part of historical geography), landscape management and landscape services (part of landscape planning), and tourism—Assessment and planning of recreational resources (part of recreational geography).
Due to its physicochemical properties, nanoparticles titanium dioxide (nTiO2) is being put into mass production and widespread applications, which inevitably results in their increasing exposure to the water body. After it entering the water body, the chemical properties of nTiO2 can be influenced by ion compositions, ion strength and pH, which affects their ecological risk. Excess of ammonium (NH4+) fertilizer has contaminated soil and water environments. In this paper, the Zeta potentials and hydrodynamic radius of nTiO2 were studied in NH4+ solution compared to those in Na+ solution. In addition, the sedimentation rate of nTiO2 was also investigated. The experiment results show that high pH inhibits the sedimentation of nTiO2. Moreover, NH4+ increases the stability of nTiO2 more than Na+ at the same IS, which was attributed the more negative Zeta potentials and the smaller hydraulic radius. Our results provide a theoretical basis for evaluating the ecological risk of nTiO2 in aqueous solution containing NH4+.
According to the World Health Organization (WHO), breast cancer is among the most common cancers worldwide. Most of the anticancer agents have been showing a variety of side effects. Recently, bacterial proteins have been investigated as promising anticancer agents. Azurin is a bacterial cupredoxin protein secreted from Pseudomonas aeruginosa and has been reported as a potent multi-targeting anticancer agent, which makes it an appropriate candidate for drug delivery. Azurin may be delivered to cancer cells using different carriers like polymeric micro and nanoparticles. In the present study, azurin was extracted from the bacterial host and loaded into chitosan particles. Then its effect on MCF-7 cell line was investigated. Chitosan-azurin particles were made using the ion gelation method. Results showed that chitosan-azurin particles are about 200 nm, and the loading of the protein in particles did not affect its integrity. The MTT assay showed a significant reduction in cell viability in azurin and chitosan-azurin-treated cells. The toxicity level after 5 days was 63.78% and 82.53% for free azurin and chitosan-azurin-treated cells, respectively. It seems using an appropriate carrier system for anticancer proteins like azurin is a promising tool for developing low side effect anticancer agents.
We studied Zeta potentials of nanoparticles titanium dioxides (nTiO2) in different concentration of NaNO3 and phosphate (P) solutions. In addition, the effect of flow rate on the transport of nTiO2 in P was investigated at pH=6.5. Experimental results show that the Zeta potential of nTiO2 is compressed with the increasing ion concentration (IC) of NaNO3 at pH=6.5. The negative charge increases with the augment of P. Therefore, the high P and low NaNO3 induce the stabilization of nTiO2 aggregates. The transport experiments suggest that the rapid flow rate is favorable for the transportability of nTiO2 and soluble phosphate. The breakthrough transport curves (BTCs) of nTiO2 in sand columns can be fitted well with two-site kinetic attachment model. The modeling results suggest that the values of first-order attachment rate coefficients (k2) and detachment rate coefficients (k2d) on site 2 and first-order attachment rate coefficients (k1) on site 1 are responsible to the attaching efficiency of nTiO2 on sands and their transportability.
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