Effects of surfactant and particle size on the microstructure and strength of Si3N4 foams with high porosity

2020 ◽  
Author(s):  
Zhongpei Du ◽  
Dongxu Yao ◽  
Yongfeng Xia ◽  
Kaihui Zuo ◽  
Jinwei Yin ◽  
...  
Keyword(s):  
Particle Size ◽  
High Porosity

Use of Municipal Solid Waste Incineration Bottom Ash in Adsorption of Heavy Metals

2011 ◽  
Vol 474-476 ◽  
pp. 1099-1102
Author(s):  
Hai Ying Zhang ◽  
Yi Zheng ◽  
Hong Tao Hu ◽  
Jing Yu Qi
Keyword(s):  
Heavy Metals ◽  
Particle Size ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Residence Time ◽  
Bottom Ash ◽  
Waste Incineration ◽  
Synthetic Wastewater ◽  
High Porosity ◽  
Municipal Solid Waste Incineration

Bottom ash from municipal solid waste incineration (MSWI) has been previously suggested as an adsorbent for removing heavy metals from wastewater due to its high porosity and large surface area. In this study the adsorption characteristics of heavy metals were investigated using various particle sizes of MSWI bottom ash. The adsorption experiment was conducted using synthetic wastewater containing Cu, Zn, Pb and Cd as a function of residence time, initial pH, ash dosage and particle size, respectively. The adsorption rate increased with decreasing particle size and with increasing residence time. Through the above analysis, this work proved that bottom ash was effective in adsorbing the four heavy metals.

Influence of Additive on the Performance of Energy Conversion Solar Cell

2013 ◽  
Vol 594-595 ◽  
pp. 980-984
Author(s):  
Nur Munirah Abdullah ◽  
Anika Zafiah M. Rus ◽  
M.F.L. Abdullah
Keyword(s):  
Particle Size ◽  
Titanium Dioxide ◽  
Solar Cell ◽  
Energy Conversion ◽  
Dye Sensitized Solar Cell ◽  
Hydroxyl Groups ◽  
High Porosity ◽  
Dye Sensitizer ◽  
Dye Sensitized ◽  
High Interaction

Dye-sensitized solar cell (DSSC) of natural dyes from local fruits which consist of the carbonyl and hydroxyl groups of anthocyanin molecule influences the performance of photosensitized effect due to high interaction on the surface of filler. The study is based on Titanium Dioxide, TiO2; U1and U2 (without and with additive respectively), treated TiO2 with ultrasonic; U3 and U4 (without and with additive respectively). The additive for electrolyte, KI3 gives effects on the rate of electron injection to the oxidized dye sensitizer. Of treated TiO2 with ultrasonic was reduced the particle size agglomeration from 0.37 μm down to 0.15 μm. This contributes to a better sponge like with high porosity in order to absorb more anchorage dye sensitizer. Treated U4 with addition of additive for electrolyte gives, Voc=0.74228 V, Isc=0.36 mA, FF=57.0124 gives 0.039% of efficiency.

scholarly journals Experiment on Seepage Property and Sand Inrush Criterion for Granular Rock Mass

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Kai Zhang ◽  
Boyang Zhang ◽  
Jiangfeng Liu ◽  
Dan Ma ◽  
Haibo Bai
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Hydraulic Properties ◽  
Distribution Parameter ◽  
Critical Conditions ◽  
High Porosity ◽  
Large Particle Size ◽  
Seepage Velocity

Water and sand inrush is one of the most serious threats in some shallow coal mines in China. In order to understand the process of sand inrush, experiments were performed to obtain the criterion for sand inrush. First, seepage tests were carried out to study the hydraulic properties of granular sandstone. The results indicate that seepage velocity has a linear relation with the porosity and particle-size distribution parameter. Then, sand inrush tests were conducted to investigate the critical conditions for sand inrush occurrence. It is determined that the sand inrush zone can be clearly distinguished based on the values of porosity and particle-size distribution parameter. Additionally, sand inrush tended to happen in the conditions of high porosity, high seepage velocity, and large particle-size distribution parameter. Further, general principles for preventing the water and sand inrush were proposed, such as reducing the porosity, improving the pore structure, and decreasing the seepage velocity. The proposed principles have been successfully used in situ to control the water and sand inrush.

Particle retention in compact constructed wetlands treating highway stormwater

2014 ◽  
Vol 69 (7) ◽  
pp. 1440-1446 ◽  
Author(s):  
Yaoping Chen ◽  
Kisoo Park ◽  
Youngchul Kim
Keyword(s):  
Particle Size ◽  
Pilot Scale ◽  
High Porosity ◽  
Treatment Tank ◽  
Micro Particles ◽  
Sedimentation Tank ◽  
Operational Lifetime ◽  
Copper Zinc ◽  
Pre Treatment ◽  
Positive Effect

Three pilot-scale compact constructed wetland systems were constructed to treat stormwater from a highway. They each comprised a sedimentation tank, and a vertical flow (VF) wetland bed equipped with a recirculation device. The VF wetland beds were filled with woodchip, pumice and volcanic gravel, respectively. According to the analysis of the particle size distributions (0.52–500 μm), the predominant particles in stormwater ranged in size from 0.52–30 μm. In the sedimentation tank, with a 24 h settling time, the settling efficiencies of the particles increased with increasing particle size. In the VF wetland beds, further capture of the particles was achieved; however, the woodchip and volcanic gravel wetlands displayed relatively low trapping of micro-particles, due to the natural properties of the substrates. Recirculation caused a positive effect on the retention of particles in the woodchip wetland. Due to the employment of a pre-treatment tank and the high porosity of materials, the accumulated solids occupied very low proportions of the pore volume in the wetland substrates. The results also showed that the accumulation of copper, zinc and lead do not pose a problem for the disposal of the substrates when the wetlands reach the end of their operational lifetime.

scholarly journals CHEMICAL AND MINERALOGICAL ASSESSMENT OF CLAYS FROM PELOPONNESE (S. GREECE) AND THEIR EVALUATION FOR UTILIZATION IN CERAMICS INDUSTRY

2017 ◽  
Vol 43 (5) ◽  
pp. 2657 ◽  
Author(s):  
K. Michailidis ◽  
G. Trontzios ◽  
E. Sofianska
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Size Fraction ◽  
High Porosity ◽  
Distribution Analysis ◽  
X Ray Diffraction ◽  
Red Clay ◽  
Ceramics Industry ◽  
Bulk Chemistry ◽  
Mineral Constituents

Mineral constituents, particle size and chemistry of ceramic raw materials may control the way ceramic products are formed and fired. Three compound (combined mixtures of 20 raw samples) clay samples from Chanakia area, Pelloponnese (S. Greece), were mineralogically and chemically investigated and their utilization as raw materials for the ceramic industry was evaluated. These samples come from different clay formations, they have red, blue and green colors and constitute the raw materials for a local brick plant. Particle size distribution analysis showed that the percentage of clay size fraction (d<2μm) ranges from 28.3 to 36.3 wt.%. X-ray diffraction analysis revealed that the main mineral constituents are quartz, micas, feldspars (plagioclases, orthoclase), calcite (except the red - clay) and clay minerals (discrete illite, mixed - layered illite/smectite, chlorite and traces of smectite and vermiculite). Projection of their bulk chemistry on some triangular discrimination diagrams has aided us to evaluate their suitability for ceramics production, namely majiolica (earthenware), cottoforte, gres and bricks were evaluated. In conclusion, all the studied materials are proved unsuitable for high quality ceramic products. Specifically, the blue and green clays were found suitable for earthenware ceramics as are high porosity building bricks, roofing tiles and similar products, while the red clay is appropriate for gres ceramics as are the low porosity tiles and bricks.

scholarly journals Effect of the Sintering Temperature on the Compressive Strengths of Reticulated Porous Zirconia

2021 ◽  
Vol 11 (12) ◽  
pp. 5672
Author(s):  
Chae-Young Lee ◽  
Sujin Lee ◽  
Jang-Hoon Ha ◽  
Jongman Lee ◽  
In-Hyuck Song ◽  
...  
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Sintering Temperature ◽  
Porous Ceramic ◽  
Average Particle Size ◽  
Porous Ceramics ◽  
Average Particle ◽  
High Porosity ◽  
Wide Range ◽  
Porous Zirconia

Porous ceramics have separation/collection (open pore) and heat-shielding/sound-absorbing (closed pore) characteristics not found in conventional dense ceramics, increasing their industrial importance along with dense ceramics. Reticulated porous ceramics, a type of porous ceramic material, are characterized by a three-dimensional network structure having high porosity and permeability. Although there have been numerous studies of porous zirconia, which is already widely used, there are insufficient reports on reticulated porous zirconia, and it is still challenging to improve the compressive strength of reticulated porous ceramics thus far, especially considering that too few studies have been published on this topic. Therefore, we prepared reticulated porous zirconia specimens using the replica template method. In this study, the compressive strength outcomes of reticulated porous zirconia were analyzed by controlling the PPI value (25, 45, 60, and 80 PPI) of the sacrificial polymer template, the average zirconia particle size (as-received, coarse, intermediate, and fine), and the sintering temperature (1400, 1500, and 1600 °C). Consequently, we confirm that it is possible to prepare reticulated porous zirconia with a wide range of strengths (0.16~1.26 MPa) as needed with an average particle size and while properly controlling the sintering temperature.

scholarly journals MW Synthesis of ZIF-7. The Effect of Solvent on Particle Size and Hydrogen Sorption Properties

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6306
Author(s):  
Vladimir A. Polyakov ◽  
Vera V. Butova ◽  
Elena A. Erofeeva ◽  
Andrei A. Tereshchenko ◽  
Alexander V. Soldatov
Keyword(s):  
Particle Size ◽  
Adsorption Process ◽  
Hydrogen Adsorption ◽  
Solvent Composition ◽  
Narrow Particle Size Distribution ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Zeolitic Imidazolate Framework ◽  
X Ray ◽  
Size Of Particles

We report here fast (15 min) microwave-assisted solvothermal synthesis of zeolitic imidazolate framework material (ZIF-7). We have optimized solvent composition to achieve high porosity and hydrogen capacity and narrow particle size distribution. It was shown that synthesis in N,N-diethylformamide (DEF) results in a layered ZIF-7 III phase, while N,N-dimethylformamide (DMF) as solvent leads to a pure ZIF-7 phase in microwave conditions. A mixture of toluene with DMF allows the production of pure ZIF-7 material only with the triethylamine additive. Obtained materials were comprehensively characterized. We have pointed out that both X-ray diffraction and infrared spectroscopy could be used for the identification of ZIF-7 or ZIF-7 III phases. Although samples obtained in DMF, and in a mixture of DMF, toluene, and triethylamine were assigned to the pure ZIF-7 phase, solvent composition significantly affected the size of particles in the material and nitrogen and hydrogen adsorption process.

scholarly journals Coupling effects of porosity and particle size on seepage properties of broken sandstone based on fractional flow equation

2019 ◽  
Vol 23 (Suppl. 3) ◽  
pp. 943-951
Author(s):  
Pei-Tao Qiu ◽  
Zhan-Qing Chen ◽  
Hai Pu ◽  
Jiong Zhu
Keyword(s):  
Particle Size ◽  
Test System ◽  
Flow Equation ◽  
Coupling Mechanism ◽  
High Porosity ◽  
Fractional Flow ◽  
Forchheimer Equation ◽  
Non Linear ◽  
Seepage Properties ◽  
Engineering Projects

Studying the seepage properties of broken rock is important for understanding the behavior of engineering projects and preventing seepage disasters from occurring. Therefore, a test system was developed to test the seepage properties of broken rock under different porosities and particle sizes. A non-linear seepage equation of broken rock was developed based on the Forchheimer equation and the theories of fraction calculus. The influence of the coupling mechanism of the porosity and particle size on the seepage properties of broken rock was analyzed. The results show that the non-linear seepage equation can describe the non-linear seepage properties of broken rock well. The relations between the permeability and the porosity and particles size can all be represented through an exponential function. It is thought that watercourses are developed in broken rock with high porosity and large particle size, which shows a stronger hydraulic conductivity capability. However, the inertial potential energy of a non-Darcy flow is relatively small.

Porous TiN Ceramics Fabricated by Carbothermal Reduction Method

2013 ◽  
Vol 745-746 ◽  
pp. 667-672 ◽  
Author(s):  
Yuan Lu ◽  
Jian Feng Yang ◽  
Zhi Liang Chen ◽  
Jian Jun Han ◽  
Jing Jing Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Pore Structure ◽  
Carbothermal Reduction ◽  
Xrd Analysis ◽  
Linear Shrinkage ◽  
Reduction Reaction ◽  
Sem Analysis ◽  
High Porosity ◽  
Microstructure And Mechanical Properties

Porous TiN ceramics with high porosity and uniform pore structure was prepared following the carbothermal reduction reaction between TiO2 and carbon. Influences of sintering additives and particle size of TiO2 on the microstructure and mechanical properties of porous TiN ceramics were investigated. Microstructure and mechanical properties of porous TiN ceramics were studied by XRD, SEM and three-point bending measurement. XRD analysis proved that the TiN phase has completely formed after reaction. In addition, SEM analysis showed that the resultant porous TiN ceramics were composed of fine grains with uniform pore structure. The addition of La2O3 not only accelerated the densification of porous TiN ceramics, but also decreased the porosity and increased the flexural strength. With a decrease in TiO2 particle size, the linear shrinkage increased and the porosity decreased accordingly.

Characterization of the residue (endocarp) of Acrocomia aculeate and its biochars as potential peat substitute in tomato cultivation

2021 ◽  
Author(s):  
Regina León Ovelar ◽  
M. Elena Fernández-Boy ◽  
Heike Knicker
Keyword(s):  
Particle Size ◽  
Sustainable Use ◽  
Chemical Characterization ◽  
N Fertilization ◽  
Organic Fertilizers ◽  
High Porosity ◽  
Suitable Alternative ◽  
Carbon Sequestration Potential ◽  
Sequestration Potential

&lt;p&gt;The South-American palm Acrocomia aculeata has great potential as a sustainable source for vegetable oils, but its industrialization implies the production of huge amounts of organic waste. Currently, this material and in particular the endocarp is mostly used for energy generation, but this traditional method is very inefficient because a considerable part of the energy is lost. &amp;#160;An environmentally more sustainable use may be its conversion into biochar, via pyrolysis. This material has recently gained considerable interest as a strategy to recycle agro-industrial waste by its conversion into a soil amendment with a high carbon sequestration potential. In addition, biochars derived from woody feedstocks show &amp;#160;high porosity and low biochemical degradability which may turn them into suitable alternative to peat as planting substrate in horticulture. Although the woody nature of the shells (endocarp) of Acrocomia represent a promising candidate for such porous biochars, this alternative has been widely neglected up to now. Therefore, in a first attempt a physical and chemical characterization of these residues and their biochars was performed and its suitability as growing substrate for tomato cultivation was evaluated. By analyzing biochars derived from feedstock with different particle size, we tested if aside from the pyrolysis conditions and the nature of the feedstock, the size of the latter may affect the nature of the pyrolyzed product.&lt;/p&gt;&lt;p&gt;Our results confirmed the increase of aromaticity with increasing pyrolysis temperature which has already been described for other organic feedstocks. The heat increase the pH only moderately (pH= 8.4 at 450&amp;#176;C). NMR spectroscopic analysis confirmed that this was caused mainly by the the selective enrichment of cations rather than by the loss of acid C groups. However, tomato plants prefer a soil pH around 6 to 6.8 which turns the biochar produced a 325&amp;#176;C with a pH = 7.2 into a more suitable growing substrate. Statistical analysis did not reveal a significant impact of particle size of the feedstock on chemical composition or pH of the resulting biochar. Comparably,&amp;#160; greater feedstock particle size did not affect the specific surface area of the biochars but considerably decreased the water holding capapcity.&amp;#160;&lt;/p&gt;&lt;p&gt;The Olsen-P increased from 39 mg kg&lt;sup&gt;-1 &lt;/sup&gt;for the natural sample to 81 mg P kg&lt;sup&gt;-1 &lt;/sup&gt;for the biochar produced at 450&amp;#176;C. K and Mg concentration were 2.6 g kg&lt;sup&gt;-1&lt;/sup&gt; and 279 mg kg&lt;sup&gt;-1&lt;/sup&gt; for the biochar yielded at 450&amp;#176;C. &amp;#160;For tomato plant cultivation, Sainju et al., (2003) recommended for P, K and Mg, 60 to 70 mg &amp;#160;kg&lt;sup&gt;-1&lt;/sup&gt;, 0.6 -0.7 g kg&lt;sup&gt;-1&lt;/sup&gt;. 0.4-0.7 g kg&lt;sup&gt;-1&lt;/sup&gt;.&amp;#160; Thus, with respect to those nutrients, the obtained biochar can provide sufficient macronutrients if used as a growing substrate for tomatos. However, due to the low N contents of the biochars, sufficient N fertilization &amp;#8211; either by addition of mineral or organic fertilizers - is still required if such materials are intended to be used as growing substrate in tomato cultivation.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Acknowledgement&lt;/strong&gt;: Financial support was provided by MINECO/FEDER (CGL2015-64811-P)&lt;/p&gt;&lt;p&gt;Sainju, U.M., Dris, R., Singh, B., 2003. Mineral nutrition of tomato. Food, Agric. Environ. 1, 176&amp;#8211;184.&lt;/p&gt;

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