Separation mechanism of chalcopyrite and pyrite due to H2O2 treatment in low-alkaline seawater flotation system

Poly(L-lactide) (PLA)/TiO2/Pt composite fiber membrane with internal porous channel structure is fabricated by skillfully tuning the breath figure mechanism and vapor induced phase separation mechanism with solute and solvent matching...

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A cloud computing separation model based on information flow

Open Physics ◽

10.1515/phys-2019-0013 ◽

2019 ◽

Vol 17 (1) ◽

pp. 128-134 ◽

Cited By ~ 1

Author(s):

Wei Ma ◽

Huanqin Li ◽

Deden Witarsyah

Keyword(s):

Cloud Computing ◽

Information Flow ◽

End Users ◽

Separation Mechanism ◽

Computing Systems ◽

Cloud Computing Security ◽

Model Based ◽

Separation Model

Abstract Separation is the primary consideration in cloud computing security. A series of security and safety problems would arise if a separation mechanism is not deployed appropriately, thus affecting the confidence of cloud end-users. In this paper, together with characteristics of cloud computing, the separation issue in cloud computing has been analyzed from the perspective of information flow. The process of information flow in cloud computing systems is formalized to propose corresponding separation rules. These rules have been verified in this paper and it is shown that the rules conform to non-interference security, thus ensuring the security and practicability of the proposed rules.

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Microwave and Ultrasound Based Methods in Sludge Treatment: A Review

Applied Sciences ◽

10.3390/app11157067 ◽

2021 ◽

Vol 11 (15) ◽

pp. 7067

Author(s):

Zoltán Jákói ◽

Balázs Lemmer ◽

Cecilia Hodúr ◽

Sándor Beszédes

Keyword(s):

Wastewater Sludge ◽

Process Efficiency ◽

H2o2 Treatment ◽

Treatment Conditions ◽

Appropriate Treatment ◽

Scientific Papers ◽

Health Related ◽

Scientific Results ◽

Treatment Procedures ◽

Anaerobic Digestibility

The amount of waste activated sludge (WAS) is increasing annually, and since it presents potential environmental and health-related risks, an appropriate treatment and stabilization process is needed. It has been shown in numerous studies in the past few decades that amongst the advanced treatment methods of sludge, microwave and ultrasound-based processes offer promising and effective alternatives. The main advantage of these physical methods is that they are energy-efficient, easy to implement and can be combined with other types of treatment procedures without major difficulties. In this review article we would like to present the recent scientific results of the microwave, ultrasound and combined (microwave-alkaline, microwave-H2O2, ultrasound-alkaline and ultrasound-H2O2) treatment of wastewater sludge, in terms of different process-efficiency indicators. Although the obtained results somewhat vary between the different scientific papers, it can be undoubtedly stated that both MW and US—either individually or in combination with chemical treatments—can enhance several aspects of sludge processing, like increasing the SCOD/TCOD rate, disintegration degree (DD), or the anaerobic digestibility (AD), but the extent of these increments clearly depends on the treatment conditions or parameters.

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Enhanced Photocatalytic Activity of Spherical Nd3+ Substituted ZnFe2O4 Nanoparticles

Materials ◽

10.3390/ma14082054 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2054

Author(s):

Loan T. T. Nguyen ◽

Hang T. T. Nguyen ◽

Thieng H. Le ◽

Lan T. H. Nguyen ◽

Hai Q. Nguyen ◽

...

Keyword(s):

Grain Size ◽

Photocatalytic Activity ◽

Dye Removal ◽

Catalyst Loading ◽

Separation Mechanism ◽

Light Radiation ◽

Efficient Separation ◽

Oxidant Concentration ◽

Znfe2o4 Nanoparticles ◽

Removal Efficiencies

In this study, nanocrystalline ZnNdxFe2−xO4 ferrites with x = 0.0, 0.01, 0.03 and 0.05 were fabricated and used as a catalyst for dye removal potential. The effect of Nd3+ ions substitution on the structural, optical and photo-Fenton activity of ZnNdxFe2−xO4 has been investigated. The addition of Nd3+ ions caused a decrease in the grain size of ferrites, the reduction of the optical bandgap energies and thus could be well exploited for the catalytic study. The photocatalytic activity of the ferrite samples was evaluated by the degradation of Rhodamine B (RhB) in the presence of H2O2 under visible light radiation. The results indicated that the ZnNdxFe2−xO4 samples exhibited higher removal efficiencies than the pure ZnFe2O4 ferrites. The highest degradation efficiency was 98.00%, attained after 210 min using the ZnNd0.03Fe1.97O4 sample. The enhanced photocatalytic activity of the ZnFe2O4 doped with Nd3+ is explained due to the efficient separation mechanism of photoinduced electron and holes. The effect of various factors (H2O2 oxidant concentration and catalyst loading) on the degradation of RhB dye was clarified.

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Excitonic structure and charge separation in the heliobacterial reaction center probed by multispectral multidimensional spectroscopy

Nature Communications ◽

10.1038/s41467-021-23060-9 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Yin Song ◽

Riley Sechrist ◽

Hoang H. Nguyen ◽

William Johnson ◽

Darius Abramavicius ◽

...

Keyword(s):

Reaction Center ◽

Charge Separation ◽

Electronic Spectroscopy ◽

Spectroscopic Studies ◽

Primary Electron ◽

Reaction Centers ◽

Separation Mechanism ◽

Photosynthetic Reaction Centers ◽

Density Analysis ◽

Function Relationship

AbstractPhotochemical reaction centers are the engines that drive photosynthesis. The reaction center from heliobacteria (HbRC) has been proposed to most closely resemble the common ancestor of photosynthetic reaction centers, motivating a detailed understanding of its structure-function relationship. The recent elucidation of the HbRC crystal structure motivates advanced spectroscopic studies of its excitonic structure and charge separation mechanism. We perform multispectral two-dimensional electronic spectroscopy of the HbRC and corresponding numerical simulations, resolving the electronic structure and testing and refining recent excitonic models. Through extensive examination of the kinetic data by lifetime density analysis and global target analysis, we reveal that charge separation proceeds via a single pathway in which the distinct A0 chlorophyll a pigment is the primary electron acceptor. In addition, we find strong delocalization of the charge separation intermediate. Our findings have general implications for the understanding of photosynthetic charge separation mechanisms, and how they might be tuned to achieve different functional goals.

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Carbon Nanodots as a Potential Transport Layer for Boosting Performance of All-Inorganic Perovskite Nanocrystals-based Photodetector

Crystals ◽

10.3390/cryst11060717 ◽

2021 ◽

Vol 11 (6) ◽

pp. 717

Author(s):

Hassan Algadi ◽

Ahmad Umar ◽

Hasan Albargi ◽

Turki Alsuwian ◽

Sotirios Baskoutas

Keyword(s):

Charge Separation ◽

High Performance ◽

Band Alignment ◽

Transport Layer ◽

Carbon Nanodots ◽

Separation Mechanism ◽

Perovskite Layer ◽

Inorganic Perovskite ◽

Highly Efficient ◽

Efficient Charge

A low-cost and simple drop-casting method was used to fabricate a carbon nanodot (C-dot)/all-inorganic perovskite (CsPbBr3) nanosheet bilayer heterojunction photodetector on a SiO2/Si substrate. The C-dot/perovskite bilayer heterojunction photodetector shows a high performance with a responsivity (R) of 1.09 A/W, almost five times higher than that of a CsPbBr3-based photodetector (0.21 A/W). In addition, the hybrid photodetector exhibits a fast response speed of 1.318/1.342 µs and a highly stable photocurrent of 6.97 µA at 10 V bias voltage. These figures of merits are comparable with, or much better than, most reported perovskite heterojunction photodetectors. UV–Vis absorption and photoluminescent spectra measurements reveal that the C-dot/perovskite bilayer heterojunction has a band gap similar to the pure perovskite layer, confirming that the absorption and emission in the bilayer heterojunction is dominated by the top layer of the perovskite. Moreover, the emission intensity of the C-dot/perovskite bilayer heterojunction is less than that of the pure perovskite layer, indicating that a significant number of charges were extracted by the C-dot layer. The studied band alignment of the C-dots and perovskites in the dark and under emission reveals that the photodetector has a highly efficient charge separation mechanism at the C-dot/perovskite interface, where the recombination rate between photogenerated electrons and holes is significantly reduced. This highly efficient charge separation mechanism is the main reason behind the enhanced performance of the C-dot/perovskite bilayer heterojunction photodetector.

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Kinetics of Microcystin-LR Removal in a Real Lake Water by UV/H2O2 Treatment and Analysis of Specific Energy Consumption

Toxins ◽

10.3390/toxins12120810 ◽

2020 ◽

Vol 12 (12) ◽

pp. 810

Author(s):

Sabrina Sorlini ◽

Carlo Collivignarelli ◽

Marco Carnevale Miino ◽

Francesca Maria Caccamo ◽

Maria Cristina Collivignarelli

Keyword(s):

Energy Consumption ◽

Specific Energy ◽

Lake Water ◽

Harmful Effect ◽

Specific Energy Consumption ◽

World Health ◽

Oh Radicals ◽

H2o2 Treatment ◽

Initial Concentration ◽

Kinetics Of

The hepatotoxin microcystin-LR (MC-LR) represents one of the most toxic cyanotoxins for human health. Considering its harmful effect, the World Health Organization recommended a limit in drinking water (DW) of 1 µg L−1. Due to the ineffectiveness of conventional treatments present in DW treatment plants against MC-LR, advanced oxidation processes (AOPs) are gaining interest due to the high redox potential of the OH• radicals. In this work UV/H2O2 was applied to a real lake water to remove MC-LR. The kinetics of the UV/H2O2 were compared with those of UV and H2O2 showing the following result: UV/H2O2 > UV > H2O2. Within the range of H2O2 tested (0–0.9 mM), the results showed that H2O2 concentration and the removal kinetics followed an increasing quadratic relation. By increasing the initial concentration of H2O2, the consumption of oxidant also increased but, in terms of MC-LR degraded for H2O2 dosed, the removal efficiency decreased. As the initial MC-LR initial concentration increased, the removal kinetics increased up to a limit concentration (80 µg L−1) in which the presence of high amounts of the toxin slowed down the process. Operating with UV fluence lower than 950 mJ cm−2, UV alone minimized the specific energy consumption required. UV/H2O2 (0.3 mM) and UV/H2O2 (0.9 mM) were the most advantageous combination when operating with UV fluence of 950–1400 mJ cm−2 and higher than 1400 mJ cm−2, respectively.

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Clog-free cell filtration using resettable cell traps

Lab on a Chip ◽

10.1039/c4lc00306c ◽

2014 ◽

Vol 14 (15) ◽

pp. 2657-2665 ◽

Cited By ~ 23

Author(s):

William Beattie ◽

Xi Qin ◽

Lin Wang ◽

Hongshen Ma

Keyword(s):

High Throughput ◽

Cell Separation ◽

Free Cell ◽

Separation Mechanism ◽

Cell Filtration ◽

Capture And Release

A microfluidic cell separation mechanism created using constrictions with adjustable size that can selectively capture and release cells, thereby enabling high throughput size and deformability based cell separation without clogging.

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