Formulation of Non-Fired Bricks Made from Secondary Aluminum Ash

The secondary aluminum ash is the black slag left after the primary aluminum ash is extracted from the metal aluminum. To address the environmental pollution and resource waste caused by the accumulation and landfill of aluminum ash, this study fabricated non-fired bricks by using secondary aluminum ash as the principal raw material, which was supplemented by cement, slaked lime, gypsum and engineering sand. The effects of mix proportions of various admixtures on the mechanical properties of non-fired bricks were investigated, and on this basis, the hydration mechanism was analyzed. The results showed that the mix proportions were 68.3% aluminum ash, 11.4% cement, 6.4% slaked lime, 4.2% gypsum and 9.7% engineering sand. The compressive strength of the fabricated bricks reached 22.19 MPa, and their quality indicators were in line with the MU20 requirements for Non-fired Rubbish Gangue Bricks. Evident hydration reaction occurred inside the non-fired bricks, with main products being calcium silicate hydrate (CSH), calcium aluminate hydrate (CAH) and ettringite (AFt). Besides, a dense structure was formed, which enhanced the brick strength.

Aluminum Alloy Selection for In Situ Composite Production by Oxygen Blowing

We considered the possibility of using AlMg10, AlCu5, AlCu5Cd, AlSi12, and AlSi7Zn9 as initial alloys for in situ composites production via oxygen blowing of hydrogen pre-saturated melts as an alternative to AlSi7Fe. The production process provides the destruction of the oxide film on the melt surface. It was demonstrated that oxide film on AlMg10 alloy did not get destroyed due to the heavy thickness because of the porous structure that contributed to its kinetically based growth. Copper-bearing alloys AlCu5 and AlCu5Cd were characterized by the low-strength oxide film and got destroyed before floating, causing the oxide porosity. Silicon-bearing alloys AlSi12 and AlSi7Zn9 provide the dense structure, which makes it clear that to understand the Pilling–Bedworth ratio for basic alloying elements is required for a non-destructed oxide void floating and shall exceed the range of 1.64–1.77. However, the oxide film in silicon-bearing alloys under investigation did not get destroyed into fine particles. AlSi7Zn9 alloy had inclusions of smaller sizes as compared to AlSi12 alloy due to the ZnO that embrittled the film, but which were grouped to form oxide islands. Moreover, zinc was evaporated during blowing. The mechanical properties of the produced composites were based on the alloys under investigation which were in line with their structures. A higher value of the Pilling–Bedworth ratio of impurities was required for fine crushing: The conventionally used AlSi7Fe alloy met this requirement and was therefore considered to be the optimum version.

Bioaugmentation of Corn Stalks Saccharification with Aspergillus Fumigatus Under Low/High Solid Loading Culture

Decomposed the dense structure of lignocellulosic feedstocks and hydrolysis lignocellulose into monosaccharide were essential prerequisite for bio-energy production at this level. In this study, a cellulosic fungi Aspergillus fumigatus CLL was conducted to pretreated the corn stalks under high/low solid loading culture to enhanced the cellulase saccharification performance. The results indicated that A. fumigatus CLL decomposed the corn stalks effectively under high/low solid loading culture, what’s more, A. fumigatus CLL completed the T. reesei cellulase system and promoted the corn stalks saccharification performance. 25.2% lignin was degraded after A. fumigatus CLL treated just for two day under low solid loading culture with holocellulose loss less than 10%. Meanwhile, the β-glucosidase of A. fumigatus CLL complemented the incomplete cellulase system of T. reesei, the maximum saccharification ratio of sample saccharified by T. reesei cellulase combined A. fumigatus CLL was comparable with the sample saccharified by commercial cellulase. Compared with raw corn stalks, the saccharification ratio of pretreated sample increased 3.1-3.4 fold. These results demonstrated that A. fumigatus CLL can be used for pretreatment of lignocellulosic materials to enhanced the saccharification performance.

Fabrication technique of composite chitosan/alginate membrane module for greywater treatment

A novel chitosan/alginate composite membrane is proposed for the application of greywater treatment. In particular, the effect of stirring speed of mixing chitosan and alginate solution was investigated in this study. The study revealed that 150CSAL and 210CSAL membranes swell significantly compared to CS membrane due to the porous structure of composite membrane. The FTIR spectra revealed that the mixing speed has no influence in terms of molecular interaction between CS and AL due to fixed CS and AL concentrations used in this study. On the other hand, the complexation of AL with CS made outstanding improvement to the dense structure of CS where 180CSAL membrane has UP water flux as high as 90 L/m2h at 2 bar. All membranes have the capability to remove the pollutants present in GW and the COD removal was further improved up to 7% using CSAL membranes. In addition, increasing mixing speed improved the pathogen removal efficiency compared to CS membrane. The treated GW met the non-potable GW reuse standard for turbidity<5 NTU and TSS<20 mg/L. To summarize, the proposed fabrication technique on CSAL membrane showed improved characteristics to CS membrane and has significant performance on GW treatment.

Performance of a Gasifier Reactor Prototype without a Blower Using Palm Oil Waste

The usage of palm oil empty fruit bunches (EFBs) in the gasification process adds value to the empty bunches as a renewable energy source. In this study, we design and manufacture a new updraft type of gasifier reactor without a blower so that it does not require electric power in its operation, but uses power from engine suction. Our test results compare the use of biomass waste in conjunction with diesel fuel to run a diesel power plant for 20 min at a load of 10,000 W: diesel with coconut shell charcoal (350 mL), diesel with acacia wood charcoal (380 mL), and diesel with EFB charcoal (400 mL). The test shows that the highest efficient and the most optimal biomass in the gasification process is coconut shell charcoal, because coconut shell charcoal has a dense structure and, at the time of the experiment, the coconut shell charcoal was filled 15 cm below the gas outlet pipe hole. From the standpoint of the economic value of the gasifier reactor that is proposed in this study, the result with the lowest cost is that of diesel with EFB charcoal, because, in this experiment, EFBs were the biomass that was not purchased. The additional use of empty fruit bunches of charcoal is able to save 50% diesel usage.

Enhanced Removal of Pb from Electrolytic Manganese Anode Slime by Vacuum Carbothermal Reduction

Electrolytic manganese anode slime (EMAS) is produced during the production of electrolytic manganese metal. In this study, a method based on vacuum carbothermal reduction was used for Pb removal in EMAS. A Pb-removal efficiency of 99.85% and MnO purity in EMAS of 97.34 wt.% was obtained for a reduction temperature of 950°C and a carbon mass ratio of 10% for a holding time of 100 min. The dense structure of the EMAS was destroyed, a large number of multidimensional pores and cracks were formed, and the Pd-containing compound was reduced to elemental Pb by the vacuum carbothermal reduction. A recovery efficiency for chemical MnO2 of 36.6% was obtained via preparation from Pd-removed EMAS through the “roasting-pickling disproportionation” process, with an acid washing time of 100 min, acid washing temperature of 70°C, H2SO4 concentration of 0.8 mol/L, liquid-solid mass ratio of 7 mL/g, calcination temperature of 60°C and calcination time of 2.5 h. Moreover, the crystal form of the prepared chemical MnO2 was found to be basically the same as that of electrolytic MnO2, and its specific surface area, micropore volume and discharge capacity were all higher than that of electrolytic MnO2. This study provides a new method for Pd removal and recycling for EMAS.

Pretreatment of Natural Lignocellulose With Inorganic Salts Improves Ligninase Production Fermented By Aspergillus Fumigatus

This work screened out the optimal conditions for pretreatment of natural lignocellulose with inorganic salts and provided a simple, easy-to-operate, low-cost, clean and efficient pretreatment method for the efficient degradation of natural lignocellulose by strains. The results showed that the optimal pretreatment inorganic salt was FeCl2 with a concentration of 11%, pretreatment at 60°C for 48 h, and the solid-liquid ratio was 1:11 (g/mL). According to the characterization results, after pretreatment of FeCl2 solution, the smooth and dense structure of natural lignocellulose surface became rough and irregular, and surface fiber bundles showed spalling and fracture. Subsequently, the enzymes produced by solid-state fermentation of Aspergillus fumigatus were easier to enter the interior, which increased the contact area between materials and enzymes, and increased the amount of enzymatic loads, thereby improving the biodegradation effect.

Research of the developed gel intracorneal colored implants for keratopigmentation based on various materials. Experimental study

Purpose. Evaluation of the impact of the developed intracorneal gel stained implants for keratopigmentation based on various materials on the donor human cornea during organotypic cultivation. Material and methods. Three experimental samples of intracorneal gel stained implants were investigated: sample 1 based on sodium hyaluronate with organic pigment, sample 2 based on collagen hydrolyzate with inorganic pigment, and sample 3 based on hydroxypropyl methylcellulose (HPMC) with organic pigment. To determine the toxicity of the studied implants the apoptosis of keratocytes was determined in cryostat sections of the cornea. The method of immunohistochemistry was used to study apoptosis. Scanning electron microscopy was used to visualize the corneal structures in the presence of implants. Results. During the investigation we showed that a gel implant based on a collagen hydrolyzate and a pigment with an inorganic toner (28% in the composition) causes a weak expression of the initiator proteins of apoptosis Caspasa 8 and Cytochrome C, and there is no expression of the BAX and effector proteins Caspasa 3/7. It was revealed that samples No. 1 and No. 3 undergo partial dissolution and washout from the intrastromal tunnel, sample No. 2 based on collagen hydrolyzate has a dense structure and remains in the corneal tunnel throughout the entire cultivation period, for at least 7 days, which is showed using an electron-scanning microscopy. The proposed collagen hydrolyzate gel implant can be considered compact and non-toxic. Conclusion. As a result of organotypic cultivation for 7 days showed the best results intracorneal colored implant № 2 based hydrolyzate of collagen and inorganic toner. Intracorneal colored implant based on collagen hydrolyzate has a more compact and dense structure than the accompanying experimental samples. Key words: keratopigmentation, aniridia, intracorneal colored implant.

EDPANs: Enhanced Dual Path Attention Networks for Single Image Super-Resolution

In this paper, we propose an enhanced dual path attention network (EDPAN) for image super-resolution. ResNet is good at implicitly reusing extracted features, DenseNet is good at exploring new features. Dual Path Network (DPN) combines ResNets and DenseNet to create a more accurate architecture than the straightforward one. We experimentally show that the residual network performs best when each block consists of two convolutions, and the dense network performs best when each micro-block consists of one convolution. Following these ideas, our EDPAN exploits the advantages of the residual structure and the dense structure. Besides, to deploy the computations for features more effectively, we introduce the attention mechanism into our EDPAN. Moreover, to relieve the parameters burden, we also utilize recursive learning to propose a lightweight model. In the experiments, we demonstrate the effectiveness and robustness of our proposed EDPAN on different degradation situations. The quantitative results and visualization comparison can sufficiently indicate that our EDPAN achieves favorable performance over the state-of-the-art frameworks.

The Effect of Red Mud Content on the Compressive Strength of Geopolymers under Different Curing Systems

To maximize the utilization of red mud in geopolymers, a red mud–metakaolin (RM-MK) geopolymer and red mud–fly ash (RM-FA) geopolymer were prepared, respectively. The effects of red mud content on the compressive strength and microstructure of the geopolymers were investigated under three different curing conditions. The results showed that the strength of the geopolymer decreased linearly with an increase in the red mud content, whether curing at room temperature or 80 °C. Surprisingly, curing in an autoclave, the appropriate amount of red mud had a favorable impact on the mechanical properties of the geopolymers. When the amount of red mud was 50%, the strength of the RM-MK geopolymer reached its highest compressive strength, 36.3 MPa, and the strength of the RM-FA geopolymer reached its highest at 31.7 MPa. Compared with curing at low temperature, curing the red mud-based geopolymers under a higher temperature and higher pressure can maximize the use of red mud. XRD analysis indicated that zeolite minerals formed. The SEM results showed that the geopolymers cured in an autoclave had a dense structure.