Ultrasound-assisted bioacid leaching was examined for the extraction of valuable metals from spent lithium ion batteries (LIBs). In this work, organic acids in lemon juice were used as the leaching ...agent together with H2O2. Three effective factors, namely solid/liquid (S/L) ratio, lemon juice percentage, and H2O2 volume percentage, were optimized using Response Surface Methodology (RSM). The optimal conditions were found to be 0.98% (w/v) S/L ratio, 57.8% (v/v) lemon juice and 8.07% (v/v) H2O2 in the leaching liquor, achieving recovery of 100% Li, 96% Co and 96% Ni. Furthermore, the individual effects of ultrasound, H2O2 and lemon juice on metal recovery were studied and the results showed that without H2O2 or lemon juice, the metal recovery rates decreased greatly while the absence of ultrasound reduced recovery rates to a much smaller extent, indicating that both H2O2 and lemon juice were essential in the leaching process. The effect of time on the metals recoveries was examined and results showed that Li and Co recovery reached 100% with the leaching time of 35 min. The modified shrinking core modeling results suggested that chemical reaction was the rate controlling step.
•Organic acids in lemon juice were used as leaching agents.•Ultrasound and H2O2 were used to assist the leaching of lithium ion batteries (LIBs).•The kinetics of the key leaching reactions was investigated.•Optimization of effective factors was done using Response Surface Methodology (RSM).
In nature, microorganisms tend to form biofilms that consist of extracellular polymeric substances with embedded sessile cells. Biofilms, especially mixed-culture synergistic biofilm consortia, are ...notoriously difficult to treat. They employ various defense mechanisms against attacks from antimicrobial agents. Problematic industrial biofilms cause biofouling as well as biocorrosion, also known as microbiologically influenced corrosion. Biocides are often used to treat biofilms together with scrubbing or pigging. Unfortunately, chemical treatments suppress vulnerable microbial species while allowing resistant species to take over. Repeated treatment cycles are typically needed in biofilm mitigation. This leads to biocide dosage escalation, causing environmental problems, higher costs and sometimes operational problems such as scale formation. New treatment methods are being developed such as enhanced biocide treatment and bacteriophage treatment. Special materials such as antibacterial stainless steels are also being created to combat biofilms. This review discussed some of the advances made in the fight against problematic industrial biofilms.
The unique linear and massless band structure of graphene in a purely two-dimensional Dirac fermionic structure has led to intense research in fields ranging from condensed matter physics to ...nanoscale device applications covering the electrical, thermal, mechanical and optical domains. Here, we report three consecutive first observations in graphene-silicon hybrid optoelectronic devices--ultralow-power resonant optical bistability, self-induced regenerative oscillations and coherent four-wave mixing--all at few-femtojoule cavity recirculating energies. These observations, in comparison with control measurements on solely monolithic silicon cavities, are enabled only by the dramatically large and ultrafast χ(3) nonlinearities in graphene and the large Q/V ratios in wavelength-localized photonic crystal cavities. These third-order nonlinear results demonstrate the feasibility and versatility of hybrid two-dimensional graphene-silicon nanophotonic devices for next-generation chip-scale high-speed optical communications, radiofrequency optoelectronics and all-optical signal processing.
This book aims to present meshfree methods in a friendly and straightforward manner, so that beginners can very easily understand, comprehend, program, implement, apply and extend these methods. It ...provides first the fundamentals of numerical analysis that are particularly important to meshfree methods. Typical meshfree methods, such as EFG, RPIM, MLPG, LRPIM, MWS and collocation methods are then introduced systematically detailing the formulation, numerical implementation and programming. Many well-tested computer source codes developed by the authors are attached with useful descriptions. The application of the codes can be readily performed using the examples with input and output files given in table form. These codes consist of most of the basic meshfree techniques, and can be easily extended to other variations of more complex procedures of meshfree methods. Readers can easily practice with the codes provided to effective learn and comprehend the basics of meshfree methods.
In this work, vanadium (V) was selectively extracted from fuel-oil fly ash using a leaching process utilizing organic acids extracted from lemon juice with assistance from ultrasound and H
2
O
2
. ...Response Surface Methodology (RSM) was used to optimize the main operating factors. The V recovery was 88.7% at the optimal conditions: 27.9% (v/v) lemon juice, 10% (v/v) hydrogen peroxide (H
2
O
2
), solid/liquid (S/L) ratio 0.01% (w/v), ultrasound power 159 W at 20 kHz in 2 h, and initial temperature of 35 °C. The effect of time on the V recovery was examined. The maximum recovery was 100% after 3 h. Furthermore, the individual effects of ultrasound and H
2
O
2
on V recovery were studied, and the results showed that without H
2
O
2
and ultrasound, the V recovery decreased greatly, indicating that both factors were essential in the leaching process. According to the modified shrinking core model, test results indicated that mass diffusion was the controlling step of the overall reaction kinetics. The activation energy of the leaching reaction in the temperature range 25 to 65 °C was found to be 17.1 kJ mol
−1
.
In this work, vanadium (V) was selectively extracted from fuel-oil fly ash using a leaching process utilizing organic acids extracted from lemon juice with assistance from ultrasound and H
2
O
2
.
Holography is a technique that is used to display objects or scenes in three dimensions. Such three-dimensional (3D) images, or holograms, can be seen with the unassisted eye and are very similar to ...how humans see the actual environment surrounding them. The concept of 3D telepresence, a real-time dynamic hologram depicting a scene occurring in a different location, has attracted considerable public interest since it was depicted in the original Star Wars film in 1977. However, the lack of sufficient computational power to produce realistic computer-generated holograms and the absence of large-area and dynamically updatable holographic recording media have prevented realization of the concept. Here we use a holographic stereographic technique and a photorefractive polymer material as the recording medium to demonstrate a holographic display that can refresh images every two seconds. A 50 Hz nanosecond pulsed laser is used to write the holographic pixels. Multicoloured holographic 3D images are produced by using angular multiplexing, and the full parallax display employs spatial multiplexing. 3D telepresence is demonstrated by taking multiple images from one location and transmitting the information via Ethernet to another location where the hologram is printed with the quasi-real-time dynamic 3D display. Further improvements could bring applications in telemedicine, prototyping, advertising, updatable 3D maps and entertainment.
In clinical assessments, the correlation between atmospheric air pollution and respiratory damage is highly complicated. Epidemiological studies show that atmospheric air pollution is largely ...responsible for the global proliferation of pulmonary disease. This is particularly significant, since most Computational Fluid Dynamics (CFD) studies to date have used monodisperse particles, which may not accurately reflect realistic inhalation patterns, since atmospheric aerosols are mostly polydisperse. The aim of this study is to investigate the anatomy and turbulent effects on polydisperse particle transport and deposition (TD) in the upper airways. The Euler-Lagrange approach is used for polydisperse particle TD prediction in both laminar and turbulent conditions. Various anatomical models are adopted to investigate the polydisperse particle TD under different flow conditions. Rossin-Rammler diameter distribution is used for the distribution of the initial particle diameter. The numerical results illustrate that airflow rate distribution at the right lung of a realistic model is higher than a non-realistic model. The CFD study also shows that turbulence effects on deposition are higher for larger diameter particles than with particles of smaller diameter. A significant amount of polydisperse particles are also shown to be deposited at the tracheal wall for CT-based model, whereas particles are mostly deposited at the carinal angle for the non-realistic model. A comprehensive, polydisperse particle TD analysis would enhance understanding of the realistic deposition pattern and decrease unwanted therapeutic aerosol deposition at the extrathoracic airways.
Background
Whilst the COVID‐19 diagnostic test has a high false‐negative rate, not everyone initially negative is re‐tested. Michigan Medicine, a primary regional centre, provided an ideal setting ...for studying testing patterns during the first wave of the pandemic.
Objectives
To identify the characteristics of patients who underwent repeated testing for COVID‐19 and determine if repeated testing was associated with downstream outcomes amongst positive cases.
Methods
Characteristics, test results, and health outcomes for patients presenting for a COVID‐19 diagnostic test were collected. We examined whether patient characteristics differed with repeated testing and estimated a false‐negative rate for the test. We then studied repeated testing patterns in patients with severe COVID‐19‐related outcomes.
Results
Patient age, sex, body mass index, neighbourhood poverty levels, pre‐existing type 2 diabetes, circulatory, kidney, and liver diseases, and cough, fever/chills, and pain symptoms 14 days prior to a first test were associated with repeated testing. Amongst patients with a positive result, age (OR: 1.17; 95% CI: (1.05, 1.34)) and pre‐existing kidney diseases (OR: 2.26; 95% CI: (1.41, 3.68)) remained significant. Hospitalization (OR: 7.88; 95% CI: (5.15, 12.26)) and ICU‐level care (OR: 6.93; 95% CI: (4.44, 10.92)) were associated with repeated testing. The estimated false‐negative rate was 23.8% (95% CI: (19.5%, 28.5%)).
Conclusions
Whilst most patients were tested once and received a negative result, a meaningful subset underwent multiple rounds of testing. These results shed light on testing patterns and have important implications for understanding the variation of repeated testing results within and between patients.
Microbiocides are used to control problematic microorganisms. High doses of microbiocides cause environmental and operational problems. Therefore, using microbiocide enhancers to make microbiocides ...more efficacious is highly desirable. 2,2-dibromo-3-nitrilopropionamide (DBNPA) is a popular biodegradable microbiocide.
d
-Amino acids have been used in lab tests to enhance microbiocides to treat microbial biofilms. In this investigation,
d
-tyrosine was used to enhance DBNPA against
Desulfovibrio vulgaris
biofilm on C1018 carbon steel. After 7 days of incubation, the mass loss of coupons without treatment chemicals in the ATCC 1249 culture medium was found to be 3.1 ± 0.1 mg/cm
2
. With 150 ppm (w/w) DBNPA in the culture medium, the mass loss was reduced to 1.9 ± 0.1 mg/cm
2
accompanied by a 1-log reduction in the sessile cell count. The 150 ppm DBNPA + 1 ppm
d
-tyrosine combination attained an extra 3-log reduction in sessile cell count and an additional 30% reduction in mass loss compared with 150 ppm DBNPA only treatment. The combination also led to a smaller maximum pit depth. Linear polarization resistance (LPR), electrochemical impedance spectrometry (EIS), and potentiodynamic polarization (PDP) tests corroborated the enhancement effects.
•Simple and compact expressions for a general elastic imperfect interface model.•Elastic fields for an imperfectly bonded spherical particle in an infinite body.•Estimates for the effective moduli of ...composites with imperfect interfaces.
This work aims at estimating the size-dependent effective elastic moduli of particulate composites in which both the interfacial displacement and traction discontinuities occur. To this end, the interfacial discontinuity relations derived from the replacement of a thin uniform interphase layer between two dissimilar materials by an imperfect interface are reformulated so as to considerably simplify the characteristic expressions of a general elastic imperfect model which is adopted in the present work and include the widely used Gurtin–Murdoch and spring-layer interface models as particular cases. The elastic fields in an infinite body made of a matrix containing an imperfectly bonded spherical particle and subjected to arbitrary remote uniform strain boundary conditions are then provided in an exact, coordinate-free and compact way. With the aid of these results, the elastic properties of a perfectly bonded spherical particle energetically equivalent to an imperfectly bonded one in an infinite matrix are determined. The estimates for the effective bulk and shear moduli of isotropic particulate composites are finally obtained by using the generalized self-consistent scheme and discussed through numerical examples.
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