• Journal of the Korean Mathematical Society
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• v.56 no.3
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• pp.689-701
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• 2019

We study the recovery results of ${\ell}_p$-constrained compressive sensing (CS) with $p{\geq}1$ via robust width property and determine conditions on the number of measurements for standard Gaussian matrices under which the property holds with high probability. Our paper extends the existing results in Cahill and Mixon from ${\ell}_2$-constrained CS to ${\ell}_p$-constrained case with $p{\geq}1$ and complements the recovery analysis for robust CS with ${\ell}_p$ loss function.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.1
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• pp.5-17
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• 2021

This study is a literature review on the recovering phosphorus from Incinerated Sewage Sludge Ash(ISSA), which has relatively high content of phosphorus. Experimental conditions and influencing factors related to the recovery of P and removal of heavy metals by wet and thermochemical methods were discussed. For the practical application of the recovery of P from ISSA, an integrated process linked to incineration facilities is required in terms of economy from the perspective of the entire system including disposal of wastewater and residues generated during the recovery process, and minimizing added chemicals and energy consumption.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.3
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• pp.236-241
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• 2005

A decolorization process using ion exchange chromatography was developed to refine rhEGF as a cosmetic ingredient. A macroreticular resin (D314) was selected, with respect to its high decolorization rate and recovery yield of rhEGF, and the operational conditions of the decolorization process optimized. The optimum conditions were as follows: the rhEGF effluent was ion exchanged at a flow rate of 60.0mL/h, with an effluent pH 5.0, using a chromatographic column (i.d. 16mm) packed with D314, with a 7.5cm in bed height. The decolorization process was carried out under the optimum conditions, and halted when the effluent volume reached 350mL, giving a decolorization rate and recovery yield of rhEGF higher than 67 and $80\%$, respectively. When the decolorization rate exceeded $67\%$, the final product turned out to be white or light yellowish, which was to the satisfaction of the cosmetic standard.

• Advances in aircraft and spacecraft science
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• v.1 no.2
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• pp.125-143
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• 2014

This paper provides a new technique for solving the static analysis of arbitrarily shaped composite plates by using Strong Formulation Finite Element Method (SFEM). Several papers in literature by the authors have presented the proposed technique as an extension of the classic Generalized Differential Quadrature (GDQ) procedure. The present methodology joins the high accuracy of the strong formulation with the versatility of the well-known Finite Element Method (FEM). The continuity conditions among the elements is carried out by the compatibility or continuity conditions. The mapping technique is used to transform both the governing differential equations and the compatibility conditions between two adjacent sub-domains into the regular master element in the computational space. The numerical implementation of the global algebraic system obtained by the technique at issue is easy and straightforward. The main novelty of this paper is the application of the stress and strain recovery once the displacement parameters are evaluated. Computer investigations concerning a large number of composite plates have been carried out. SFEM results are compared with those presented in literature and a perfect agreement is observed.

• Journal of Powder Materials
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• v.24 no.4
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• pp.315-320
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• 2017

There has been much interest in recycling electronic wastes in order to mitigate environmental problems and to recover the large amount of constituent metals. Silver recovery from electronic waste is extensively studied because of environmental and economic benefits and the use of silver in fabricating nanodevices. Hydrometallurgical processing is often used for silver recovery because it has the advantages of low cost and ease of control. Research on synthesis recovered silver into nanoparticles is needed for application to transistors and solar cells. In this study, silver is selectively recovered from the by-product of electrodes. Silver precursors are prepared using the dissolution characteristics of the leaching solution. In the liquid reduction process, silver nanoparticles are synthesized under various surfactant conditions and then analyzed. The purity of the recovered silver is 99.24%, and the average particle size of the silver nanoparticles is 68 nm.

• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.507-516
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• 2014

We present a hybrid method for spectral reflectivity recovery, using 3D extrapolation as a supplemental method for 3D interpolation. The proposed 3D extrapolation is an extended version of 3D interpolation based on the barycentric algorithm. It is faster and more accurate than the conventional spectral-recovery techniques of principal-component analysis and nonnegative matrix transformation. Four different extrapolation techniques (based on nearest neighbors, circumcenters, in-centers, and centroids) are formulated and applied to recover spectral reflectivity. Under the standard conditions of a D65 illuminant and 1964 $10^{\circ}$ observer, all reflectivity data from 1269 Munsell color chips are successfully reconstructed. The superiority of the proposed method is demonstrated using statistical data to compare coefficients of correlation and determination. The proposed hybrid method can be applied for fast and accurate spectral reflectivity recovery in image processing.

• Environmental Engineering Research
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• v.25 no.2
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• pp.222-229
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• 2020

Membrane assisted condenser is an innovative membrane operation that exploits the hydrophobic nature of microporous membranes to promote water vapor condensation and recovery. It can be used for water and chemicals recovery from waste gaseous streams. In this work, the testing of membrane condenser for water and ammonia recovery from synthetic streams (i.e., a saturated air stream with ammonia) simulating the plume of cooling tower is illustrated. The modeling of the process was carried out for predicting the membrane-based process performance and for identifying the minimum operating conditions for effectively recovering liquid water. The experimental data were compared with the results achieved through the simulations showing good agreement and confirming the validity of the model. It was found that the recovery of water can be increased growing the temperature difference between the plume and the membrane module (DT), the relative humidity of the plume (RH^plume) and the feed flow rate on membrane area ratio. Moreover, the concentration of NH₃ in the recovered liquid water increased with the growing DT, at increasing NH₃ concentration in the fed gaseous stream and at growing relative humidity of the feed.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.1
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• pp.29-37
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• 2018

In this study, optimum extraction conditions for phosphorus recovery from sewage sludge ash(SSA) were investigated. For this purpose, an experiment was conducted to determine optimal recovery conditions for Ca-P type phosphorus by using calcium component in the recycled aggregate residue. The phosphorus content of sewage sludge ash was confirmed to be 5.0 %. When $H_2SO_4$ was used as an extract, concentration of 1 N $H_2SO_4$, L/S ratio of 10, and extraction time of 30 min were found to be the optimal extraction conditions. Phosphorus was extracted by using optimal extraction conditions, and then the heavy metals eluted with phosphorus were removed using 1~20 g of cation exchange resin. In 20 g of cation exchange resin, Fe 71.3%, Cu 82.4%, Zn 79.9%, and Cr 15% were removed. After that, the mixing ratio of the calcium extract obtained from the recycled aggregate residue (RAR) was changed to 1:1, 1:5, 1:10. The pH of the SSA to RAR mixture was adjusted to 2, 4, 8 and 12 by the addition of 5 N NaOH to the mixture of 1:5, and the phosphorus was recovered as Ca-P type precipitate. The optimum pH was 8. When recycled aggregate residues were used, the weight of calcium phosphate increased, but the amount of wastewater generated also increased. Therefore, it was concluded that the use of recycled aggregate residue was not economically feasible.

• Resources Recycling
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• v.6 no.3
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• pp.41-45
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• 1997

The recovery of tellurium from Te-cement obtained during the processing of copper anode slimes was carried out by a series of hydrometallurgical processes, i.E. leaching Te-cement in NaOH solution, precipitation of impurities with the addition of ${Na}_{2}S$ followed by direct electrowinning of tellurium in NaOH solution. The optimum conditions for each process were determined and discussed in terms of various parameters associated with each step to maximize the recovery and purity of tellurium. The final purity of tellurium from electrownning in alkaline solution was found to be more than 99.9%.

• Journal of environmental and Sanitary engineering
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• v.15 no.1
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• pp.62-68
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• 2000

This study was investigated to the recovery of alumina from the first calcined waste pottery using alkaline sintering. This study was based on calcination result of a commercial ${\alpha}-Al2_O_3$ with NaOH powder. $NaAlO_2$ was formed by calcination of ${\alpha}-Al_2O_3$ with NaOH and conversion of $NaAlO_2$ from ${\alpha}-Al_2O_3$ was 91.4% at calcination condition ; weight ritio of $NaOH/{\alpha}-Al2_O_3$ 1.5, $800^{\circ}C$, and 90min. The first calcined waste porrery from the manufacturing Procedure of H Ltd. was grinded to 170/270mesh by a ball mill and calcined over $500^{\circ}C$ with NaOH powder. The calcined sample was dissolved in $25^{\circ}C$ water and sodiumaluminosilicate solid was formed. After filtration, the contained aluminum was leached out by dissolving sodiumaluminosilicate solid in 1N HCl. We estimated the efficiency of Al extraction from waste pottery by ICP analysis and NaOH was added to the filtrate and then aluminum compound was precipitated with $Al(OH)_3$ and recovered. The investigation was carried out with the variables ; the calcination temperature($500-900^{\circ}C$), the calcination time(30~90min), and the weight ratio of NaOH/waste pottery(0.5~1.5). The treatment efficiency of the waste pottery and the recovery of Al as 97.9%, 91.9% were obtained under the optimum conditions as followed ; the weight ratio of NaOH/waste pottery was 1.5 and the calcination conditions were $900^{\circ}C$ and 60min.