A novel underdetermined source recovery algorithm based on k-sparse component analysis

Sparse component analysis (SCA) is a popular method for addressing underdetermined blind source separation in array signal processing applications. We are motivated by problems that arise in the applications where the sources are densely sparse (i.e. the number of active sources is high and very close to the number of sensors). The separation performance of current underdetermined source recovery (USR) solutions, including the relaxation and greedy families, reduces with decreasing the mixing system dimension and increasing the sparsity level (k). In this paper, we present a k-SCA-based algorithm that is suitable for USR in low-dimensional mixing systems. Assuming the sources is at most (m−1) sparse where m is the number of mixtures; the proposed method is capable of recovering the sources from the mixtures given the mixing matrix using a subspace detection framework. Simulation results show that the proposed algorithm achieves better separation performance in k-SCA conditions compared to state-of-the-art USR algorithms such as basis pursuit, minimizing norm-L1, smoothed L0, focal underdetermined system solver and orthogonal matching pursuit

Net Analyte Signal Standard Additions Method for Simultaneous Determination of Sulfamethoxazole and Trimethoprim in Pharmaceutical Formulations and Biological Fluids

The applicability of a novel net analyte signal standard addition method (NASSAM) to the resolving of overlapping spectra corresponding to the sulfamethoxazole and trimethoprim was verified by UV-visible spectrophotometry. The results confirmed that the net analyte signal standard additions method with simultaneous addition of both analytes is suitable for the simultaneous determination of sulfamethoxazole and trimethoprim in aqueous media. Moreover, applying the net analyte signal standard additions method revealed that the two drugs could be determined simultaneously with the concentration ratios of sulfamethoxazole to trimethoprim varying from 1:35 to 60:1 in the mixed samples. In addition, the limits of detections were 0.26 and 0.23 μmol L-1 for sulfamethoxazole and trimethoprim, respectively. The proposed method has been effectively applied to the simultaneous determination of sulfamethoxazole and trimethoprim in some synthetic, pharmaceutical formulation and biological fluid samples

Enhanced photocatalytic activity of Fe3O4-WO3-APTES for azo dye removal from aqueous solutions in the presence of visible irradiation

Development of highly active photocatalysts for treatment of dye-laden wastewaters is vital. The photocatalytic removal of azo dye Reactive Black 5 was investigated by Fe3O4-WO3-3-aminopropyltriethoxysilane (APTES) nanoparticles in the presence of visible light. The Fe3O4-WO3-APTES nanoparticles were synthesized via a facile coprecipitation method. The photocatalyst was characterized by XRD, FT-IR, SEM, EDX, VSM, UV�Vis, and pHPZC techniques. The effects of some operational parameters such as solution pH, nanophotocatalyst dosage, initial RB5 concentration, H2O2 concentration, different purging gases, and type of organic compounds on the removal efficiency were studied by the Fe3O4-WO3-APTES nanoparticles as a photocatalyst. Maximum phtocatalytic activity was obtained at pH 3. The photocatalytic removal of RB5 increased with increasing H2O2 concentration up to 5�mM. The removal efficiency declined in the presence of different purging gases and all types of organic compounds. First-order rate constant (kobs) decreased from 0.027 to 0.0022�min�1 and electrical energy per order (EEo) increased from 21.33 to 261.82 (kWh/m3) with increasing RB5 concentration from 10 to 100�mg/L, respectively. The efficiency of LED/Fe3O4-WO3-APTES process for RB5 removal was approximately 89.9, which was more effective than the LED/Fe3O4-WO3 process (60.72). Also, photocatalytic activity decreased after five successive cycles. © 2018 Taylor & Franci

Enhanced photocatalytic activity of Fe 3 O 4 -WO 3 -APTES for azo dye removal from aqueous solutions in the presence of visible irradiation

Development of highly active photocatalysts for treatment of dye-laden wastewaters is vital. The photocatalytic removal of azo dye Reactive Black 5 was investigated by Fe 3 O 4 -WO 3 -3-aminopropyltriethoxysilane (APTES) nanoparticles in the presence of visible light. The Fe 3 O 4 -WO 3 -APTES nanoparticles were synthesized via a facile coprecipitation method. The photocatalyst was characterized by XRD, FT-IR, SEM, EDX, VSM, UV�Vis, and pH PZC techniques. The effects of some operational parameters such as solution pH, nanophotocatalyst dosage, initial RB5 concentration, H 2 O 2 concentration, different purging gases, and type of organic compounds on the removal efficiency were studied by the Fe 3 O 4 -WO 3 -APTES nanoparticles as a photocatalyst. Maximum phtocatalytic activity was obtained at pH 3. The photocatalytic removal of RB5 increased with increasing H 2 O 2 concentration up to 5 mM. The removal efficiency declined in the presence of different purging gases and all types of organic compounds. First-order rate constant (k obs ) decreased from 0.027 to 0.0022 min �1 and electrical energy per order (E Eo ) increased from 21.33 to 261.82 (kWh/m 3 ) with increasing RB5 concentration from 10 to 100 mg/L, respectively. The efficiency of LED/Fe 3 O 4 -WO 3 -APTES process for RB5 removal was approximately 89.9, which was more effective than the LED/Fe 3 O 4 -WO 3 process (60.72). Also, photocatalytic activity decreased after five successive cycles. © 2018, © 2018 Taylor & Francis

Enhanced photocatalytic activity of Fe3O4-WO3-APTES for azo dye removal from aqueous solutions in the presence of visible irradiation

Development of highly active photocatalysts for treatment of dye-laden wastewaters is vital. The photocatalytic removal of azo dye Reactive Black 5 was investigated by Fe3O4-WO3-3-aminopropyltriethoxysilane (APTES) nanoparticles in the presence of visible light. The Fe3O4-WO3-APTES nanoparticles were synthesized via a facile coprecipitation method. The photocatalyst was characterized by XRD, FT-IR, SEM, EDX, VSM, UV�Vis, and pHPZC techniques. The effects of some operational parameters such as solution pH, nanophotocatalyst dosage, initial RB5 concentration, H2O2 concentration, different purging gases, and type of organic compounds on the removal efficiency were studied by the Fe3O4-WO3-APTES nanoparticles as a photocatalyst. Maximum phtocatalytic activity was obtained at pH 3. The photocatalytic removal of RB5 increased with increasing H2O2 concentration up to 5�mM. The removal efficiency declined in the presence of different purging gases and all types of organic compounds. First-order rate constant (kobs) decreased from 0.027 to 0.0022�min�1 and electrical energy per order (EEo) increased from 21.33 to 261.82 (kWh/m3) with increasing RB5 concentration from 10 to 100�mg/L, respectively. The efficiency of LED/Fe3O4-WO3-APTES process for RB5 removal was approximately 89.9, which was more effective than the LED/Fe3O4-WO3 process (60.72). Also, photocatalytic activity decreased after five successive cycles. © 2018 Taylor & Franci

Photocatalytic reduction of Cr(VI) from synthetic, real drinking waters and electroplating wastewater by synthesized amino-functionalized Fe3O4�WO3 nanoparticles by visible light

Cr(VI) was reduced from synthetic, real drinking waters and real electroplating wastewater using the Fe3O4�WO3-3-aminopropyltriethoxysilane nanoparticles, as a heterogeneous catalyst, in the presence of visible light. The nanocatalyst was prepared via a simple co-precipitation method. FT-IR and SEM techniques proved the effective presence of an amino group. Under the optimum conditions: pH = 2, Cr(VI)0 = 10 mg/L, citric Acid = 10 mg/L, and nanocatalyst dosage = 6 g/L, 99.96% of Cr(VI) was removed after 300 min. Approximately 82.96% of Cr(VI) in a real water sample was removed after 1440 min under the optimal circumstances. Also, full treatment of electroplating wastewater was reached after 2880 min. © 2017 The Korean Society of Industrial and Engineering Chemistr

Photocatalytic degradation of a textile dye by illuminated tungsten oxide nanopowder

In this study, photocatalytic degradation of Acid Orange 7 (AO7) by tungsten oxide nanopowder under UV irradiation was investigated with variation of pH, WO3 dosage, initial AO7 concentration, purging gas, type of organic compounds and initial hydrogen peroxide concentration. Removal efficiency was decreased by increasing pH and initial AO7 concentration. The removal efficiency of AO7 was increased by purging of oxygen gas and by addition of hydrogen peroxide. The reaction rate constant (kobs) was decreased from 0.0225 to 0.0006 min-1 with increasing initial AO7 concentration from 5 to 50 mg/L, respectively. © 2015 Science & Technology Network, Inc

Photocatalytic reduction of Cr(VI) from synthetic, real drinking waters and electroplating wastewater by synthesized amino-functionalized Fe3O4�WO3 nanoparticles by visible light

Cr(VI) was reduced from synthetic, real drinking waters and real electroplating wastewater using the Fe3O4�WO3-3-aminopropyltriethoxysilane nanoparticles, as a heterogeneous catalyst, in the presence of visible light. The nanocatalyst was prepared via a simple co-precipitation method. FT-IR and SEM techniques proved the effective presence of an amino group. Under the optimum conditions: pH = 2, Cr(VI)0 = 10 mg/L, citric Acid = 10 mg/L, and nanocatalyst dosage = 6 g/L, 99.96% of Cr(VI) was removed after 300 min. Approximately 82.96% of Cr(VI) in a real water sample was removed after 1440 min under the optimal circumstances. Also, full treatment of electroplating wastewater was reached after 2880 min. © 2017 The Korean Society of Industrial and Engineering Chemistr

Improvement of NOM Removal from Water Resources by Modifying the Coagulation Process

As a result of the regulations on DBPs, interest in NOM removal is increasing and many water treatment plants in developed countries have started to measure the concentration of TOC in their finished waters. Promulgation of the rules will substantially increase these efforts in other countries too. Since the cost of TOC (and DBPs) determination was high, it was decided to study the traditional analysis of COD as a surrogate measure to detect the organic constituents in raw water and the extent to which optimized coagulation with ferric chloride can increase COD removal. The two water samples studied belonged to Karaj and Jajrood Rivers. For both samples the observed values of COD removal by coagulation at lower pH (about 1-1.5 pH values less than the regular pH) were about 85-95 percent without making water turbidity unacceptable. In order to determine the effects of organic content on coagulation, synthetic samples were also prepared with much higher COD values. Again, considerable increases in COD removal have been observed for most of these samples only by decreasing 0.5-2 pH value. The results indicated that a modified coagulation process without need to much increasing the amount of coagulant can be developed for these water samples