Herein, g-C3N4 and NiMoO4, which are moderate energy band gap semiconductors, have been effectively hybridized to create Z scheme heterojunction for successful visible-light photocatalytic converting ...CO2 into valuable products including CH4, CO, O2 and HCOOH. Ni(NO3)2·6H2O and (NH4)6Mo7O24·4H2O were used as precursors to synthesize NiMoO4 photocatalyst, which was continuously mixed with melamine before calcinating at 520 °C for 6 h to get NiMoO4/g-C3N4 Z scheme heterojunction. We explored that NiMoO4 intimately contacted with g-C3N4. These band positions of the NiMoO4 were also perfectly matched with those of the g-C3N4. Therefore, these photo-induced e− on conduction band of the NiMoO4 could easily travel to h+ on valence band of the g-C3N4 (recombination); thereby, minimize h+ and e− recombination in each material. Therefore, the NiMoO4/g-C3N4 direct Z-scheme heterojunctions could produce significant available h+ on the valence band of the NiMoO4 and e− on the conduction band of the g-C3N4. These e−/h+ have suitable redox potential to effectively convert CO2. Finally, the optimized g-C3N4 mole ratio for maximum enhancing photocatalytic efficiency of the NiMoO4/g-C3N4 heterojunction was 60%. When the g-C3N4 content increased to 70%, the excess g-C3N4 amount would entirely cover NiMoO4 surface leaded to form dense and closed shell. The formed closed shell decreased contact between NiMoO4 and CO2 as well as the interface charge transfer, which reduced the e− and h+ separation and transfer leading to decrease in photocatalytic conversion efficiency.
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•Successfully created NiMoO4/g-C3N4 Z scheme heterojunction for CO2 conversion.•Hybridization of NiMoO4 and g-C3N4 prevented recombination of e−/h+ in each material.•The created NiMoO4/g-C3N4 converted CO2 into HCOOH, CH4 and CO even under visible light.•The optimal molar ratio of g-C3N4/NiMoO4 for the best photocatalytic conversion was 60%.
•Properties of red mud in Vietnam's Tan Rai Alumina plant.•Dissolution ratio of SiO2 and Al2O3 in red mud, fly ash under different conditions.•Properties of red mud based alkali activated material ...after high temperature and autoclave curing.•Regression between the compressive strength and the total amount of dissolved SiO2.
To produce the alkali activated material, red mud must be used with components containing active silicon dioxide because silicon dioxide in red mud does not dissolve in alkaline solution. The test results presented in this paper show that high pressure and high temperature treatment in an autoclave can dissolve part of the silicone dioxide in red mud and improve the properties of material. The compressive strength of red mud based alkali activated materials can reach 10.6 MPa with a softening coefficient over 0.70. Adding an active silicon dioxide supplement by replacing 26.3 wt% red mud with fly ash increases the compressive strength up to 20 MPa and the softening coefficient by more than 0.90. Furthermore, autoclave treatment reduces residual sodium hydroxide and lowers the pH value of material. As the result, red mud based and red mud-fly ash based alkali activated materials can be used for manufacturing of masonry units.
The objective of this study was to assess the levels of heavy metals in animal feed, manure, and sediment in the farm environment’s field water supply and drainage system. Samples of animal feed were ...collected from pigs at various growth stages, as well as feces and sediment samples from the discharge system leading to the Day River. An analysis of the samples found concentrations of Cu and Zn that ranged from 61 to 2,731 and 151–4,269 mg/kg·TS, respectively, which was significantly higher than the acceptable Vietnamese standards for agricultural land. The ecological risk coefficient in the estuary to the open channel potential ecological index (RI) exceeded 600, indicating a high level of ecological risk in the contaminated pig farm area. Furthermore, the study assessed the impacts of Cu, Fe, Pb, and Zn on anaerobic biodegradation of pig manure, revealing that levels of these metals from 0–40 mg/L, negatively affected biogas yield, with a decrease from 4.38% to 15.30%. Moreover, the treatment efficiency of chemical oxygen demand (COD) and total solids (TS) was affected adversely with a decline from 35.57% to 43.86%. The study found that the most impactful metals on the biogas yield were Pb, Zn, and Cu in that order, respectively. Conversely, the concentration of Fe level of 12 mg·Fe/L demonstrated a significant increase in the biogas yield and higher efficiency of TS and COD treatment compared to non-metallic samples. However, an increase in concentration from 20 to 40 mg·Fe/L resulted in an adverse effect, reducing the biogas yield. Essentially, this research was conducted to aid in management control measures to regulate the input of raw materials and feed, drinking water, and sanitation procedures implemented in the pig site. This would assist in limiting the propagation of heavy metals into the immediate environment.
In this work, nitrile butadiene rubber (NBR)/chloroprene rubber (CR) blends were prepared and investigated. The results showed that NBR and CR in the NBR/CR (50/50) blend were partially compatible. ...This blend had a relatively regular and compact structure, which improved the mechanical properties as well as the weather resistance, thermal stability, and oil, grease resistances. At the DLH compatibilizer content of 1% (made from Cashew nut shell liquid) or D01 (made from Tung oil), the materials possess better mechanical and physical properties due to much more regular and compact structure. NBR/CR blends can be potential materials for industrial applications which demand high oil and grease resistance and good weather resistance as well as good thermal stability.
Impact of viscoelastic droplets Wang, Yuli; Do-Quang, Minh; Amberg, Gustav
Journal of non-Newtonian fluid mechanics,
05/2017, Volume:
243
Journal Article
Peer reviewed
•Phase field simulation of droplet impact of viscoelastic fluids.•Moving contact line of viscoelastic fluids.•Non-monotonic dependence of contact angle on contact line speed, which violates the ...Tanner-Cox-Vionov law.
We conduct numerical experiments on viscoelastic droplets hitting a flat solid surface. The results present time-resolved non-Newtonian stresses acting in the droplet. Comparing with the simulation of the impact of a Newtonian droplet, the effects of viscoelasticity on droplet behaviors such as splashing, the maximum spreading diameter and deformation are analyzed. With detailed information on the contact line region, we demonstrate how the contact line behaves according to the transition of the fluid property from elasticity dominated to shear-thinning dominated when a droplet expands and contracts on the substrate. The propose of this work is to discuss whether and how the elasticity in an impinging droplet takes effect.
•The densification of the PHS was controlled by the sintering temp and holding time.•At 1300 ℃, 30 min, MS samples were 33 % relative density and 2 MPa compressive strength.•Fine grains with higher ...density were found from the use of microwave sintering.•The Ag-coated on PHS was nano spherical, at about 79.8 ± 21.4 nm particle size.
In this study, the optimization of the dual-frequency microwave sintering furnace in the replica method was investigated for the rapid synthesis of Porous hydroxyapatite scaffolds (PHS). It was found that by controlling the microwave sintering condition, it is possible to produce PHS with promising abilities for bone tissue engineering applications.
Recent progress studies in light of wireless communication systems mainly centred around two focuses: zero-energy consumption and ultra-reliable and low-latency communication (URLLC). Among various ...cutting-edge areas, exploiting ambient backscatter communication (Backcom) has recently been devised as one of the foremost solutions for achieving zero energy consumption through the viability of ambient radio frequency. Meanwhile, using short-packet communication (SPC) is the cheapest way to reach the goal of URLLCs. Upon these benefits, we investigate the feasibility of Backcom and SPC for symbiotic wireless sensor networks by analyzing the system performance. Specifically, we provide a highly approximated mathematical framework for evaluating the block-error rate (BLER) performance, followed by some useful asymptotic results. These results provide insights into the level of diversity and coding gain, as well as how packet design impacts BLER performance. Numerical results confirm the efficacy of the developed framework and the correctness of key insights gleaned from the asymptotic analyses.
Avian influenza A (H5N1) viruses cause severe disease in humans, but the basis for their virulence remains unclear. In vitro and animal studies indicate that high and disseminated viral replication ...is important for disease pathogenesis. Laboratory experiments suggest that virus-induced cytokine dysregulation may contribute to disease severity. To assess the relevance of these findings for human disease, we performed virological and immunological studies in 18 individuals with H5N1 and 8 individuals infected with human influenza virus subtypes. Influenza H5N1 infection in humans is characterized by high pharyngeal virus loads and frequent detection of viral RNA in rectum and blood. Viral RNA in blood was present only in fatal H5N1 cases and was associated with higher pharyngeal viral loads. We observed low peripheral blood T-lymphocyte counts and high chemokine and cytokine levels in H5N1-infected individuals, particularly in those who died, and these correlated with pharyngeal viral loads. Genetic characterization of H5N1 viruses revealed mutations in the viral polymerase complex associated with mammalian adaptation and virulence. Our observations indicate that high viral load, and the resulting intense inflammatory responses, are central to influenza H5N1 pathogenesis. The focus of clinical management should be on preventing this intense cytokine response, by early diagnosis and effective antiviral treatment.
Natural rubber (NR) latex was modified with graphene (GR) and graphene oxide (GO). These flaky carbonaceous nanofillers were characterized by Raman and X-ray photoelectron spectroscopy techniques, ...and added to NR in an amount of up to 5 parts per hundred rubber (phr) in the presence and absence of cetyltrimethyl ammonium bromide (CTAB). CTAB was supposed to trigger π-cation interactions with GR and GO. Interfacial changes were examined by Raman and infrared spectroscopy techniques, dynamic mechanical analysis and differential scanning calorimetry. The dispersion of the nanofillers using scanning electron microscopy was studied. It was found that CTAB prominently affected the reinforcing efficiency and mechanical loss of the NR nanocomposites, which was traced to changes in the NR fraction immobilized on the filler's surfaces. The π-cation interaction between GR, GO and CTAB, for which indirect proof was found, seems to be a useful tool to tailor the interphase, and thus the related properties (mechanical loss, reinforcing and Payne effects) in the corresponding NR nanocomposites.
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