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1.
Materials (Basel) ; 16(20)2023 Oct 17.
Article in English | MEDLINE | ID: mdl-37895717

ABSTRACT

In this study, the evolutions of Cube and {115}<161> orientations of a cold-rolled ultra-thin non-oriented silicon steel were investigated using a combination of experimental investigation and the crystal plasticity finite element method (CPFEM). The results show that Cube orientations remain relatively stable when their initial deviation angles from the ideal Cube orientation are less than 12°, even after a 60% cold rolling reduction. However, larger deviations occur due to higher strain near grain boundaries. Furthermore, the {115}<161> orientations, with an initial deviation of ~18° from the ideal Cube orientation, become separated into different orientation regions during cold rolling. Some regions gradually approach the ideal Cube orientation as cold rolling progresses and reach ~12.5° deviation from the ideal Cube at a 40% reduction. This study demonstrates good agreement between simulation and experimental results, highlights the micro-deformation mechanisms during rolling, and offers insights for optimizing the ultra-thin strip rolling process.

2.
Sensors (Basel) ; 22(17)2022 Sep 04.
Article in English | MEDLINE | ID: mdl-36081144

ABSTRACT

Chip pad inspection is of great practical importance for chip alignment inspection and correction. It is one of the key technologies for automated chip inspection in semiconductor manufacturing. When applying deep learning methods for chip pad inspection, the main problem to be solved is how to ensure the accuracy of small target pad detection and, at the same time, achieve a lightweight inspection model. The attention mechanism is widely used to improve the accuracy of small target detection by finding the attention region of the network. However, conventional attention mechanisms capture feature information locally, which makes it difficult to effectively improve the detection efficiency of small targets from complex backgrounds in target detection tasks. In this paper, an OCAM (Object Convolution Attention Module) attention module is proposed to build long-range dependencies between channel features and position features by constructing feature contextual relationships to enhance the correlation between features. By adding the OCAM attention module to the feature extraction layer of the YOLOv5 network, the detection performance of chip pads is effectively improved. In addition, a design guideline for the attention layer is proposed in the paper. The attention layer is adjusted by network scaling to avoid network characterization bottlenecks, balance network parameters, and network detection performance, and reduce the hardware device requirements for the improved YOLOv5 network in practical scenarios. Extensive experiments on chip pad datasets, VOC datasets, and COCO datasets show that the approach in this paper is more general and superior to several state-of-the-art methods.


Subject(s)
Algorithms , Neural Networks, Computer
3.
Chemosphere ; 93(8): 1593-9, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24001664

ABSTRACT

Multi-walled carbon nanotube-filled electrospun nanofibrous membranes (MWCNT-ENFMs) were prepared by electrospinning. The addition of MWCNTs (0.5 wt.% vs. ENFMs) doubled the specific surface area and tensile strength of the ENFMs. The MWCNT-ENFMs were used to adsorb perfluorooctane sulfonate (PFOS) in aqueous solutions. The sorption kinetics results showed that the sorption rate of PFOS onto the MWCNT-ENFMs was much higher than the sorption rate of PFOS onto the pure ENFMs control, and the pseudo-second-order model (PSOM) described the sorption kinetics well. The sorption isotherms indicated that the sorption capacity of the MWCNT-ENFMs for PFOS (16.29±0.26 µmol g(-1)) increased approximately 18 times, compared with the pure ENFMs (0.92±0.06 µmol g(-1)). Moreover, the solution pH significantly affected the sorption efficiency and sorption mechanism. The MWCNT-ENFMs were negatively charged from pH 2.0-10.0, but the electrostatic repulsion between the MWCNT-ENFMs and PFOS was overcome by the hydrophobic interactions between PFOS and the MWCNTs or nanofibers. The strong hydrophobic interactions between PFOS and the MWCNTs played a dominant role in the sorption process. For the pure ENFMs, the electrostatic repulsion was conquered by the hydrophobic interactions between PFOS and the nanofibers at pH>3.1. In addition to the hydrophobic interactions, an electrostatic attraction between PFOS and the pure ENFMs was involved in the sorption process at pH<3.1.


Subject(s)
Alkanesulfonic Acids/chemistry , Fluorocarbons/chemistry , Nanotubes, Carbon/chemistry , Water Pollutants, Chemical/chemistry , Adsorption , Alkanesulfonic Acids/analysis , Fluorocarbons/analysis , Hydrophobic and Hydrophilic Interactions , Kinetics , Waste Disposal, Fluid/methods , Water Pollutants, Chemical/analysis , Water Purification/methods
4.
J Hazard Mater ; 248-249: 254-60, 2013 Mar 15.
Article in English | MEDLINE | ID: mdl-23385205

ABSTRACT

The remediation of polycyclic aromatic hydrocarbons (PAHs) polluted waters has become a concern as a result of the widespread use of PAHs and their adverse impacts on water ecosystems and human health. To remove PAHs rapidly and efficiently in situ, an active fibrous membrane, laccase-loading spider-type reactor (LSTR) was fabricated by electrospinning a poly(D,L-lactide-co-glycolide) (PDLGA)/laccase emulsion. The LSTR is composed of beads-in-string structural core-shell fibers, with active laccase encapsulated inside the beads and nanoscale pores on the surface of the beads. This structure can load more laccase and retains higher activity than do linear structural core-shell fibers. The LSTR achieves the efficient removal/degradation of PAHs in water, which is attributed to not only the protection of the laccase activity by the core-shell structure but also the pre-concentration (adsorption) of PAHs on the surface of the LSTR and the concentration of laccase in the beads. Moreover, the effects of pH, temperature and dissolved organic matter (DOM) concentration on the removal of PAHs by the LSTR, in comparison with that by free laccase, have been taken into account. A synergetic mechanism including adsorption, directional migration and degradation for PAH removal is proposed.


Subject(s)
Laccase/chemistry , Lactic Acid/chemistry , Polycyclic Aromatic Hydrocarbons/chemistry , Polyglycolic Acid/chemistry , Water Pollutants, Chemical/chemistry , Adsorption , Hydrogen-Ion Concentration , Membranes, Artificial , Polylactic Acid-Polyglycolic Acid Copolymer , Water Purification/instrumentation , Water Purification/methods
5.
J Hazard Mater ; 246-247: 119-25, 2013 Feb 15.
Article in English | MEDLINE | ID: mdl-23295768

ABSTRACT

Horseradish peroxidase (HRP) is successfully in situ encapsulated into the poly(D,L-lactide-co-glycolide) (PLGA)/PEO-PPO-PEO (F108) electrospun fibrous membranes (EFMs) by emulsion electrospinning. The adsorption and degradation of pentachlorophenol (PCP) by HRP-EFMs are investigated. The experimental results show that the sorption kinetic of PCP on EFMs follows the pseudo-second-order model, and the sorption capacity is as high as 44.69 mg g(-1). The sorption mechanisms of EFMs for PCP can be explained by hydrogen bonding interactions, hydrophobic interactions and π-π bonding interactions. Profiting from the strong adsorption, the removal of PCP can be dramatically enhanced by the interaction of adsorbed PCP and HRP on the surface of EFMs. For PCP degradation, the optimal pH values for free HRP and immobilized HRP are 4 and 2-4, respectively. As pH>4.7, no adsorption and degradation are observed due to the deprotonation of PCP. The removal percentages reach 83% and 47% for immobilized HRP and free HRP, respectively, at 25 ± 1°C. The presence of humic acid can inhibit the activity of HRP and decreases the adsorption capacity of PCP because of competitive adsorption. The operational and storage stability of immobilized HRP are highly improved through emulsion electrospinning.


Subject(s)
Enzymes, Immobilized/metabolism , Horseradish Peroxidase/metabolism , Pentachlorophenol/metabolism , Water Pollutants, Chemical/metabolism , Adsorption , Enzymes, Immobilized/antagonists & inhibitors , Enzymes, Immobilized/chemistry , Horseradish Peroxidase/antagonists & inhibitors , Horseradish Peroxidase/chemistry , Humic Substances , Hydrogen-Ion Concentration , Kinetics , Lactic Acid/chemistry , Membranes, Artificial , Pentachlorophenol/chemistry , Polyglycolic Acid/chemistry , Polylactic Acid-Polyglycolic Acid Copolymer , Temperature , Thermodynamics
6.
J Hazard Mater ; 192(3): 1409-17, 2011 Sep 15.
Article in English | MEDLINE | ID: mdl-21752545

ABSTRACT

Five types of nanofibrous membranes were prepared by electrospinning poly(ε-caprolactone) (PCL), poly(D,L-lactide) (PDLLA), poly(lactide-co-caprolactone) (P(LA/CL)), poly(D,L-lactide-co-glycolide) (PDLGA) and methoxy polyethylene glycol-poly(lactide-co-glycolide) (MPEG-PLGA), respectively. These electrospun nanofibrous membranes (ENFMs) were used to adsorb anthracene (ANT), benz[a]anthracene (BaA) and benzo[a]pyrene (BaP) from aqueous solution, and the sorption kinetics and isotherms of these PAHs on the five ENFMs were investigated. The pseudo-second-order model (PSOM) can well describe the sorption kinetics of the three PAHs on five ENFMs, and the partition-adsorption model (PAM) can interpret the sorption processes of PAHs on the ENFMs. PCL ENFMs, which had the largest surface areas (8.57 m(2)g(-1)), exhibited excellent sorption capacity for ANT at over 4112.3 ± 35.5 µg g(-1). Moreover, the hydrophobicity and pore volume of ENFMs significantly affected the sorption kinetics and sorption capacity of the PAHs. The main sorption mechanisms of three PAHs on the PDLLA ENFMs included hydrophobic interactions and pore-filling, while those of PCL, P(LA/CL) and PDLGA ENFMs were dominated by the hydrophobic interactions. The sorption mechanisms of MPEG-PLGA ENFMs primarily included pore-filling, hydrogen bonding interactions and hydrophobic interactions. Additionally, π-π bonding interaction was also deduced to be involved in all of ENFMs sorption systems.


Subject(s)
Nanoparticles/chemistry , Polycyclic Aromatic Hydrocarbons/analysis , Adsorption , Anthracenes/chemistry , Hydrogen Bonding , Hydrophobic and Hydrophilic Interactions , Kinetics , Materials Testing , Microscopy, Electron, Scanning/methods , Models, Chemical , Nanotechnology/methods , Polyesters/chemistry , Time Factors , Water Pollutants, Chemical/analysis , Water Purification/methods
7.
Bioresour Technol ; 101(23): 8942-7, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20673716

ABSTRACT

Laccase from Trametes versicolor was successfully in situ encapsulated into the poly(D,L-lactide) (PDLLA)/PEO-PPO-PEO (F108) electrospun microfibers by emulsion electrospinning. The porous morphology of electrospun microfibers was observed with scanning electron microscope, and the core-shell structure of microfibers and existence of laccase in microfibers were proved by laser confocal scanning microscopy micrograph. In this study, fibrous porosity and core-shell structure are advantageous to the activity and stability preservation of immobilized laccase. The activity of immobilized laccase could retain over 67% of that of the free enzyme. After 10 successive runs in the enzyme reactor, the immobilized laccase could also maintain 50% of its initial activity. Crystal violet dye was successfully degraded by the PDLLA/F108-laccase electrospun microfiber membranes. It was observed that the immobilized laccase possessed a broadening pH range of catalysis activity compared to free laccase.


Subject(s)
Biotechnology/methods , Enzymes, Immobilized/metabolism , Laccase/metabolism , Nanofibers/chemistry , Trametes/enzymology , Benzothiazoles/pharmacology , Biodegradation, Environmental/drug effects , Coloring Agents/chemistry , Coloring Agents/metabolism , Emulsions , Enzyme Stability/drug effects , Gentian Violet/chemistry , Gentian Violet/metabolism , Hydrogen-Ion Concentration/drug effects , Particle Size , Polyesters/pharmacology , Sulfonic Acids/pharmacology
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