Large Effective Area Research Articles

Three-Year Clinical and Hemodynamic Evaluation of the Hydra Self-Expanding Transcatheter Aortic Valve in Patients With Severe Aortic Stenosis.

The Hydra CE study revealed 1-year favorable efficacy of TAVR, showing a large effective orifice area (EOA), low gradient, and acceptable complication rates. We evaluated the 3-year clinical and hemodynamic outcomes of Hydra self-expanding transcatheter aortic valve (manufactured by Vascular Innovations Co Ltd, Nonthaburi, Thailand; a subsidiary of Sahajanand Medical Technologies Limited, India) in patients with symptomatic severe aortic stenosis at high or extremely high surgical risk. The Hydra CE study was a prospective, multicenter, single-arm study. A total of 157 patients were enrolled in the study, out of whom 54 patients from two centers (Lithuania and Poland) had provided consent for long-term follow-up at recruitment, with a planned 5-year follow-up period. The primary endpoint was all-cause mortality, and patients were followed up for up to 3 years, with an assessment of clinical and echocardiographic outcomes. Among the 54 patients, the average age was 81.0 ± 4.1 years. The mean STS score was 3.2 ± 2.0%. At 3 years, all-cause mortality had occurred in 14.8% of patients, including 3.7% cardiovascular deaths and 1.9% device-related deaths. There was a progressive enhancement in EOA that is, 0.68 ± 0.15 cm2 at baseline to 1.97 ± 0.52 cm2 at 3 years (p < 0.001) as well as significant improvement in the mean aortic valve gradient that is, 53.4 ± 14.24 mmHg at baseline to 8.6 ± 2.80 mmHg at 3 years (p < 0.001). New permanent pacemaker implantation rates up to 3-year follow-up was 12.9%. The 3-year results of the Hydra CE study demonstrated consistent improvements in hemodynamics over time. The study also revealed favorable safety and efficacy trends, along with low occurrences of new permanent pacemaker implantations and paravalvular leaks.

Heterostructured GCN Nanosheets/ZnO nanoflowers for enhanced TMO loading: From high-performance three electrode systems to printed flexible asymmetric supercapacitors

Transition metal oxides (TMOs) are widely used in the development of high-energy-density devices due to their multiple oxidation states and their frequent heterostructuring with carbon-based materials. However, the synthesis process often leads to severe nanoparticle agglomeration and weak synergistic effects with carbon-based templates, thereby limiting their application potential. In this study, we constructed graphitic carbon nitride (GCN) nanosheets/ZnO nanoflowers (NFs) structures with high TMOs loading by utilizing GCN nanosheets, which are rich in surface nitrogen content, as enriched templates for metal ions in conjunction with ultrasonic cavitation. Compared with GCN nanosheets/ZnO nanoparticles (NPs), the ZnO NFs exhibited vertical growth and a fluffy structure on a 2D material template, which resulted in high electronic conductivity, a large effective surface area, hierarchical pores, and strong synergistic interactions with GCNs, thus improving electrochemical performance. This structural enhancement enabled the GCN/ZnO NFs electrodes to achieve a high specific capacitance of 1524F g−1 at a current density of 1 A g−1 in a three-electrode supercapacitor system. Additionally, we formulated GCN/ZnO NFs into electronic inks and used them for the mass production of flexible supercapacitors with the aid of dispensing printing technology. These flexible supercapacitors retained 94% of their specific capacitance even under extreme conditions of 90° torsion. Our proposed strategy of modulating TMOs and 2D structures can create active electrode materials with higher loading capacities, thereby enabling comprehensive customization in material design and device preparation processes.

Coral-like Ti3C2Tx/PANI Binary Nanocomposite Wearable Enzyme Electrochemical Biosensor for Continuous Monitoring of Human Sweat Glucose

With the continuous advancement of contemporary medical technology, an increasing number of individuals are inclined towards self-monitoring their physiological health information, specifically focusing on monitoring blood glucose levels. However, as an emerging flexible sensing technique, continuous and non-invasive monitoring of glucose in sweat offers a promising alternative to conventional invasive blood tests for measuring blood glucose levels, reducing the risk of infection associated with blood testing. In this study, we fabricated a flexible and wearable electrochemical enzyme sensor based on a two-dimensional Ti3C2Tx MXene nanosheets and coral-like polyaniline (PANI) binary nanocomposite (denoted as Ti3C2Tx/PANI) for continuous, non-invasive, real-time monitoring of sweat glucose. The exceptional conductivity of Ti3C2Tx MXene nanosheets, in conjunction with the mutual doping effect facilitated by coral-like PANI, significantly enhances electrical conductivity and specific surface areas of Ti3C2Tx/PANI. Consequently, the fabricated sensor exhibits remarkable sensitivity (25.16 μA·mM−1·cm−2), a low detection limit of glucose (26 μM), and an extensive detection range (0.05 mM ~ 1.0 mM) in sweat. Due to the dense coral-like structure of Ti3C2Tx/PANI binary nanocomposite, a larger effective area is obtained to offer more active sites for enzyme immobilization and enhancing enzymatic catalytic activity. Moreover, the sensor demonstrates exceptional mechanical performance, enabling a 60° bend in practical applications, thus satisfying the rigorous demands of human sweat detection applications. The results obtained from continuous 60 min in vitro monitoring of sweat glucose levels demonstrate a robust correlation with the data of blood glucose levels collected by a commercial glucose meter. Furthermore, the fabricated Ti3C2Tx/PANI/GOx sensor demonstrated agreement with HPLC findings regarding the actual concentration of added glucose. This study presents an efficient and practical approach for the development of a highly reliable MXene glucose biosensor, enabling stable and long-term monitoring of glucose levels in human sweat.

Dual signal amplification strategy-based electrochemical aptasensor utilizing redox molecule/MOF composites for multi-pesticide detection

Electrochemical aptasensor is a great tool for simultaneously assessing harmful pesticide residues in agricultural products and foods. This study ingeniously designed an electrochemical aptasensor based on dual signal amplification strategies for concurrent detection of various pesticide residues. Firstly, poly(diallyldimethylammonium chloride)-functionalized reduced graphene oxide (PR) and Au-Pt-Pd trimetallic nanoflowers supported on HP-UiO66-NH2 were creatively employed together as substrates to load more aptamers, ascribed to the improved conductivity, abundant sites and a large electrochemical effective surface area. Secondly, ferrocene-cysteine gold nanoparticles supported on CeMOF(Ⅲ, Ⅳ) and methylene blue-loaded MOF235 were innovatively engineered to build two distinctive signal labels, which displayed comparable large and stable signal currents among other redox molecule/MOF composites. Additionally, PR contributed further signal amplification. Consequently, the constructed aptasensor showed superior performance for simultaneous detection of acetamiprid (AD) and malathion (ML), with linear ranges from 10 pM to 0.1 μM and detection limits of 4.8 pM for AD and 0.51 pM for ML. Moreover, the aptasensor performed well in the assay of AD and ML in Chinese cabbage samples with high accuracy compared with a high-performance liquid chromatography-tandem mass spectrometry method. Overall, the strategies proposed herein provided a useful and potential route for general development of electrochemical aptasensors to simultaneously detect multiple pesticide residues.

Multicore fiber design housing a fluorine-doped low-latency core and cutoff shifted cores

Design of heterogeneous 4-core fiber housing a low-latency core and conventional cutoff shifted cores in a standard 125-μm cladding diameter is investigated to enable signal processing delay reduction using common mode impairment. For the low-latency core, 1-μs propagation delay reduction and an optical signal-to-noise ratio (OSNR) comparable to or greater than that of cutoff shifted cores are required. In this paper, we consider an F-doped core and depressed cladding structure with a large effective area as the low-latency core. It can be expected to achieve sufficient group delay reduction of the low-latency core, the OSNR unification among heterogeneous cores, and low inter-core crosstalk in a standard 125-μm cladding diameter. Consequently, we revealed the optimized low-latency core achieving the group delay reduction of 1 μs and the OSNR as same level as the cutoff shifted cores as we expected. The designed heterogeneous 4-core fiber with the standard 125-μm cladding diameter suppressed the inter-core crosstalk to be low enough to support a 1,000-km long transmission. We expect the figure-of-merit (FoM) of the 4-core fiber to be as high as previously reported 4-core fibers, and the FoM improvement are found when the low latency core and cutoff shifted core are placed alternately thanks to the core heterogeneity.

Biomedical Metal–Organic framework materials on antimicrobial therapy: Perspectives and challenges

As a barrier between the structure of the human body's internal organs and the outside environment, the skin serves crucial physiological tasks like protection, regulation, and metabolism. The skin's close interaction with the outside makes it particularly vulnerable to many injuries. Bacterial infections cause wound healing to take longer, raise the risk of chronic harm, and serve as a breeding ground for drug-resistant bacteria. As a result, it is critical to eliminate bacterial species from the wound region rapidly and efficiently. Metal-organic frameworks (MOFs), are critically adjustable hybrid materials that integrate organic ligands with coordination metals to generate a range of topologically isomorphic structures. MOFs' creation and shape are investigated by the metal source and ligand utilized in the reaction process, and the structural benefits of this near-infinite combination of structures allow boundless potential for their surface functionalization. MOF has a large effective surface area, tunable structure, adaptability, excellent biodegradability, high drug load, adjustable release of drugs, robust targeting, etc. It can be loaded with therapeutic materials and has programmability. It is more conducive to treating complex wounds while realizing the synergistic effects of antibacterial, anti-inflammatory, and pro-angiogenesis, effectively improving treatment safety. This review summarizes the most recent research advances on various MOFs for antimicrobial therapy, using diverse types of metal-ion-based MOFs as an entry point. Finally, it covers several important challenges in the antimicrobial treatment of metal-ion-based MOFs.

High-Yield WS2 Synthesis through Sulfurization in Custom-Modified Atmospheric Pressure Chemical Vapor Deposition Reactor, Paving the Way for Selective NH3 Vapor Detection.

Nanostructured transition metal dichalcogenides have garnered significant research interest for physical and chemical sensing applications due to their unique crystal structure and large effective surface area. However, the high-yield synthesis of these materials on different substrates and in nanostructured films remains a challenge that hinders their real-world applications. In this work, we demonstrate the synthesis of two-dimensional (2D) tungsten disulfide (WS2) sheets on a hundred-milligram scale by sulfurization of tungsten trioxide (WO3) powder in an atmospheric pressure chemical vapor deposition reactor. The as-synthesized WS2 powders can be formulated into inks and deposited on a broad range of substrates using techniques like screen or inkjet printing, spin-coating, drop-casting, or airbrushing. Structural, morphological, and chemical composition analysis confirm the successful synthesis of edge-enriched WS2 sheets. The sensing performance of the WS2 films prepared with the synthesized 2D material was evaluated for ammonia (NH3) detection at different operating temperatures. The results reveal exceptional gas sensing responses, with the sensors showing a 100% response toward 5 ppm of NH3 at 150 °C. The sensor detection limit was experimentally verified to be below 1 ppm of NH3 at 150 °C. Selectivity tests demonstrated the high selectivity of the edge-enriched WS2 films toward NH3 in the presence of interfering gases like CO, benzene, H2, and NO2. Furthermore, the sensors displayed remarkable stability against high levels of humidity, with only a slight decrease in response from 100% in dry air to 93% in humid environments. Density functional theory and Bayesian optimization simulations were performed, and the theoretical results agree with the experimental findings, revealing that the interaction between gas molecules and WS2 is primarily based on physisorption.

FSI investigation on the discharge valve lift in a R32 rotary compressor and its verification

R32 rotary compressor is commonly applied in the household air conditioner. The valve motion is significant to the performance and reliability of rotary compressor. Valve lift is an important factor which directly affects the valve motion. A suitable valve lift can both reduce power consumption and fracture risk of valve plate. Based on a compressor prototype, this paper developed a FSI model to simulate the working process of discharge valve. The simulation results show that a large valve lift means a large discharge effective flow area and a low indicated power. But both the velocity of valve plate impacting the retainer and the impact stress of valve plate are relatively large, which will lead to the fracture in the valve plate. The simulated initial impact location on the head of valve plate is near the oblique incision due to the uneven pressure distribution in the discharge port and the torsional movement of valve plate. The maximum impact stress distribution areas on the valve plate obtained from simulation results are matched with the fracture areas of two valve plate samples, which proves that the simulation results are accurate enough to guide the optimization design of discharge valve in the rotary compressor.

Response of the first POLAR-2 prototype to polarized beams

POLAR-2 is a dedicated gamma-ray polarimeter currently foreseen to be launched towards the China Space Station around 2027. The design of the detector is based on the legacy of its predecessor mission POLAR which was launched in 2016. POLAR-2 aims to measure the polarization of the Gamma-ray Burst prompt emission within the 30–800 keV energy range. Thanks to its high sensitivity to gamma-ray polarization, as well as its large effective area, POLAR-2 will provide the most precise measurements of this type to date. Such measurements are key to improve our understanding of the astrophysical processes responsible for Gamma-Ray Bursts. The detector consists of a segmented array of plastic scintillator bars, each one of which is read out by a Silicon PhotoMultiplier channel. The flight model of POLAR-2 will contain a total of 6400 scintillators. These are divided into 100 groups of 64 bars each, in so-called polarimeter modules. In recent years, the collaboration has designed and produced the first prototypes of these polarimeter modules and subjected these to space qualification tests. In addition, in April 2023, the first of these modules were calibrated using fully polarized gamma-ray beams at the European Synchrotron Radiation Facility (ESRF) in France. In this work, we will present the results of this calibration campaign and compare these to the simulated performance of the POLAR-2 modules. Potential improvements to the design are also discussed. Finally, the measurements are used, in combination with the verified simulation framework, to estimate the scientific performance of the full POLAR-2 detector and compare it to its predecessor.

The Evolution of Galaxies and Clusters at High Spatial Resolution with Advanced X-ray Imaging Satellite (AXIS)

Stellar and black hole feedback heat and disperse surrounding cold gas clouds, launching gas flows off circumnuclear and galactic disks, producing a dynamic interstellar medium. On large scales bordering the cosmic web, feedback drives enriched gas out of galaxies and groups, seeding the intergalactic medium with heavy elements. In this way, feedback shapes galaxy evolution by shutting down star formation and ultimately curtailing the growth of structure after the peak at redshift 2–3. To understand the complex interplay between gravity and feedback, we must resolve both the key physics within galaxies and map the impact of these processes over large scales, out into the cosmic web. The Advanced X-ray Imaging Satellite (AXIS) is a proposed X-ray probe mission for the 2030s with arcsecond spatial resolution, large effective area, and low background. AXIS will untangle the interactions of winds, radiation, jets, and supernovae with the surrounding interstellar medium across the wide range of mass scales and large volumes driving galaxy evolution and trace the establishment of feedback back to the main event at cosmic noon. This white paper is part of a series commissioned for the AXIS Probe mission concept; additional AXIS white papers can be found at the AXIS website.

Efficient removal of Pb (II) ions from aqueous solution by the Moringa oleifera synthesized magnetic ZnFe2O4 spinel nanoparticles

Water-based Pb(II)ion removal was tested on Moringa oleifera modified ZnFe2O4 nanoparticles. For the strong crystal plane, XRD analysis predicts high crystallinity and 18 nm average crystallite sizes. Tetrahedral and octahedral spikes oscillate at 650 and 482 cm−1, metal ions like Zn-O and Fe-O resonate at 400–600 cm−1. Porosity particles and complicated integration linkages with hydroxyl groups from distinct fatty acid sequences characterise omega-3 and zinc ion nanoparticles. HRTEM images revealed spherical ZnFe2O4 nanoparticles with an average diameter of 8–12 nm and interplanar spacing and lattice fringes matching the tetragonal phase's (311) crystal plane. Due to interparticle gaps, N2 equilibrium temperatures at 77.5 K produced mesoporous material with 120.6 m2 g−1 BET specific surface area and 15.6 nm pore width. Spinel ZnFe2O4 demonstrated photocatalytic activity in daylight with prolonged UV-to-visible photo absorption. Prepared nanoparticles exhibited ferromagnetic functionality, a saturation magnetic field of 10 emu/g, a permanence of 2 emu/g, and a forcefulness of 100 Oersted has, which is less than the significant value of 72 emu/g. Lead elimination kinetics show that PSO kinetics better capture adsorption kinetics than PFO kinetics. Rate diffusion-driven surface features may potentially explain Pb(II) adsorption kinetics. pH 6.2 is optimal for Pb(II) removal. Adsorption process seems endothermic and impulsive. Monolayer adsorption over a consistent region may have deposited Pb(II) on ZnFe2O4. Langmuir method found ZnFe2O4 maximum adsorption capacity of 142.2 lead (mg)/adsorbent (g) and it adsorbs lead (II) ions similarly to other adsorption agents, perhaps due to its large effective surface area.

Microwave assisted synthesis of α-Fe2O3 half-hexagon nanoplates as an anode material for Li ion batteries

In this study, hematite α-Fe2O3 half-hexagon nanoplates have been successfully prepared by ethanol–water mediated microwave assisted solvothermal method. The high crystalline nature and rhombohedral crystal structure of the synthesized α-Fe2O3 were confirmed from X-ray diffraction (XRD) results. No impurity phase other than hematite α-Fe2O3 was detected. Raman spectroscopy results further revealed the hematite structure of α-Fe2O3. X-ray photoelectron spectroscopy (XPS) study disclosed the chemical composition and valence states in the synthesized α-Fe2O3 material. Field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM) studies confirmed the half-hexagon plate like architecture for α-Fe2O3 along with some irregular shape nanoplates. When treated as an anode material for Li ion battery (LIB), α-Fe2O3 half-hexagon nanoplates delivered a reversible discharge capacity of 520 mAh.g−1 after 100 cycles at a high current density of 500 mA.g−1. The α-Fe2O3 half-hexagon nanoplates also exhibited excellent cycling performance and coulombic efficiency. The excellent performance of the α-Fe2O3 electrode is mainly ascribed to the plate like morphology of the particles, which offers large effective contact area with the electrolyte and significantly enhances the electrochemical performance.

A Sensitive Enzymatic Electrochemical Biosensor for Cholesterol Based on Cobalt Ferrite@Molybdenum Disulfide/Gold Nanoparticles.

Cholesterol is essential in biological systems, and the level of cholesterol in the body of a person acts as a diagnostic marker for a variety of diseases. So, in this work, we fabricated an enzymatic electrochemical biosensor for cholesterol using cobalt ferrite@molybdenum disulfide/gold nanoparticles (CoFe2O4@MoS2/Au). The synthesized composite was used for the determination of cholesterol by voltametric methods. The electroactive material CoFe2O4@MoS2/Au was successfully verified from the physiochemical studies such as XRD, Raman, FT-IR, and XPS spectroscopy along with morphological FESEM and HRTEM characterization. CoFe2O4@MoS2/Au showed outstanding dispersion in the aqueous phase, a large effective area, good biological compatibility, and superior electronic conductivity. The microflower-like CoFe2O4@MoS2/Au was confirmed by scanning electron microscopy. The image of transmission electron microscopy showed decoration of gold nanoparticles on CoFe2O4@MoS2 surfaces. Furthermore, a one-step dip-coating technique was used to build the biosensor used for cholesterol detection. In addition to acting as an enabling matrix to immobilize cholesterol oxidase (ChOx), CoFe2O4@MoS2/Au contributes to an increase in electrical conductivity. The differential pulse voltammetry method was used for the quantitative measurement of cholesterol. The calibration curve for cholesterol was linear in the concentration range of 5 to 100 μM, with a low limit of detection of 0.09 μM and sensitivity of 0.194 μA μM-1 cm-2. Furthermore, the biosensor demonstrates good practicability, as it was also employed for identifying cholesterol in real samples with acceptable selectivity and stability.

Direct Affinity Ligand Immobilization onto Bare Iron Oxide Nanoparticles Enables Efficient Magnetic Separation of Antibodies.

Magnetic separation is a promising alternative to chromatography for enhancing the downstream processing (DSP) of monoclonal antibodies (mAbs). However, there is a lack of efficient magnetic particles for successful application. Aiming to fill this gap, we demonstrate the suitability of bare iron oxide nanoparticles (BION) with physical site-directed immobilization of an engineered Protein A affinity ligand (rSpA) as an innovative magnetic material. The rSpA ligand contains a short peptide tag that enables the direct and stable immobilization onto the uncoated BION surface without commonly required laborious particle activation. The resulting BION@rSpA have beneficial characteristics outperforming conventional Protein A-functionalized magnetic particles: a simple, fast, low-cost synthesis, a particle size in the nanometer range with a large effective specific surface area enabling large immunoglobulin G (IgG) binding capacity, and a high magnetophoretic velocity advantageous for fast processing. We further show rapid interactions of IgG with the easily accessible rSpA ligands. The binding of IgG to BION@rSpA is thereby highly selective and not impeded by impurity molecules in perfusion cell culture supernatant. Regarding the subsequent acidic IgG elution from BION@rSpA@IgG, we observed a hampering pH increase caused by the protonation of large iron oxide surfaces after concentrating the particles in 100 mM sodium acetate buffer. However, the pH can be stabilized by adding 50 mM glycine to the elution buffer, resulting in recoveries above 85% even at high particle concentrations. Our work shows that BION@rSpA enable efficient magnetic mAb separation and could help to overcome emerging bottlenecks in DSP.

Analysis of performance limits in optical communications due to fiber nonlinearity and third order dispersion

In this study, an analysis is conducted to treasure the expressions of the pulsation expansion factor, in addition to the standardized output, and solve the nonlinear Schrödinger equation (NLSE), reflecting the impact of XPM on third order dispersion. Using large effective area fiber (LEAF) and standard single-mode fiber (SSMF), the effects of transmission distances and varying input powers are assessed at various transmission speeds. The first and second order GVD XPM effects are the only factors influencing the pulse’s propagation. The second-order effects of GVD are not noticeable at short distances and low bit rates, but they become noticeable and impact system performance as the bit rate increases. The study discovered that input dominance has less of an impact on pulse width than data rate and fiber length. Methodical derivation and numerical simulation using the split-phase Fourier method at the same data rate and input power yield the SSMF and LEAF consequences. In comparison to LEAF fibers, XPM has a greater beneficial impact on second and third order dispersion in SSMF fibers.

Dispersive wave generation in single higher-order modes of a large-core silica step-index fiber with pulse energies up to 12 nJ.

The generation of light in a laser system is constrained by the gain medium, limiting the available wavelengths. We demonstrate in-fiber generation of ultrafast pulses between ∼550 and 800 nm via dispersive wave generation (DWG), in higher-order modes (HOMs). Using higher-order modes enables power scaling, due to their large effective area compared to the fundamental modes of single-mode fibers and dispersion engineering, even in simple step-index fibers. The process occurs in a single higher-order mode, which we excite using passive glass components (an axicon and two telescopes). The output pulses have energies up to 12 nJ at the biologically relevant wavelength of 705 nm.

3x3 array module of 8×8×32 mm3 position-sensitive virtual frisch-grid CdZnTe detectors for imaging and spectroscopy of cosmic gamma-rays

We evaluated the performance of the 3 × 3 array of 32-mm long position-sensitive virtual Frisch-grid (VFG) CdZnTe (CZT) detectors read out by the IDEAS GDS-100 data acquisition system. The array is a mechanically solid module designed for integration into a large effective area gamma-ray telescope proposed for imaging and spectroscopy of cosmic gamma-rays. The array employs the bar-shaped 8 × 8 × 32 mm3 CZT crystals which recently became available from Redlen Technologies, Inc. and Kromek-eV Group PLC at affordable costs. The waveform sampling IDE3421 application-specific integrated circuit (ASIC), developed by the University of Michigan and IDEAS for CZT pixel detectors, was adapted to capture the signals from the array's VFG detectors. We showed good spectral performance of the Redlen detectors with an energy resolution of <1% FWHM at 662 keV and slightly poorer performance of the Kromek-eV detectors with a resolution of <2% measured at a reduced temperature of 13 °C. By testing the same detectors as single devices using hybrid charge-sensitive preamplifiers, we demonstrated improved energy resolutions at a normal temperature of ∼25 °C: <1% and 1.3–1.7%, respectively. However, the Kromek-eV detectors did not perform as well as the Redlen ones. We explained this by the space charge formation (polarization) decreasing the electric field and the electron drift times. The polarization was likely caused by the high injections of holes from the anode contacts. The absence of polarization in Redlen detectors suggested that the quality of the contacts might have played a role in this case.

A Solar Evaporator Based on Polypyrrole Coated 3D Carbon Nanotube Materials for Efficient Solar-Driven Vapor Generation.

Highly porous light absorbers are fabricated based on polypyrrole (PPy)-coated carbon nanotube (CNT). Carbon nanotube sponge (CNTS) or carbon nanotube array (CNTA) with three-dimensional (3D) network structure is the framework of porous light absorbers. Both PPy@CNTS and PPy@CNTA composites exhibit excellent light absorption of the full solar spectrum. The CNTS and CNTA with porous structures have extremely large effective surface area for light absorption and for water evaporation that has great practical benefit to the solar-driven vapor generation. The PPy layer on CNT sidewalls significantly improves the hydrophilicity of porous CNTS and CNTA. The good wettability of water on CNT sidewalls makes water transport in porous CNT materials highly efficient. The PPy@CNTS and PPy@CNTA light absorbers achieve high water evaporation rates of 3.35 and 3.41kg m-2 h-1 , respectively, under 1-sun radiation. The orientation of nano channels in CNTA-based light absorbers also plays an important role in the solar-driven vapor generation. The water transport and vapor escape are more efficient in CNTA-based light absorbers as compared to the CNTS-based light absorbers due to the relatively short path for the water transport and the vapor escape in CNTA-based light absorbers.

Norfloxacin adsorption by torrefied coco peat biochar as a novel adsorbent in a circular economy framework

The current study reported torrefied coco-peat biochar treated at 200 °C, as a novel adsorbent exhibiting phenomenal norfloxacin (NFX) adsorption efficiency. The CHNS analysis confirmed the carbon abundance in the biochar (36.45%), however, XRF analysis indicated a significant presence of K2O (27.73%) and chlorine (7.49%). The XRD and Raman spectral analysis confirmed the amorphous structure of the biochar. Multilayer topology was evident in the SEM micrograph of biochar contributing to its large effective surface area. Additionally, the mesoporous structure of the adsorbent was verified by BET. The adsorption mechanism was predicted to be non-ionic since the zeta potential of both adsorbent and adsorbate was found negative. The process parameters were optimized at 30 °C, pH 6.9, dosage 7 g/L, antibiotic load 494.25 mg/L, and time of 89 min for a maximum of 99.52% adsorption of NFX using Central Composite Design, Analysis of Variance, and Response Surface Methodology. The adsorption process was exothermic, and spontaneous obeying the pseudo-second-order kinetics, while the bulk process was confined to surface adsorption. Isotherm study of NFX adsorption revealed the process to be a favorable, monolayer, and homogeneous adsorption. The NFX molecules were desorbed with an efficiency of 89.19% using 80% ethanol and upon recrystallization, 87.76% of the initial NFX was recovered as crude crystal. Moreover, the NFX removal efficiency was consistent across various water systems, tap water (99.02%), seawater (99.56%), river water (98.92%), pond water (98.26%), and distilled water (99.17%). The techno-economic analysis identified bulk expense as the biochar preparation ($0.82/kg) and the process will be profitable having recovered NFX sold at $6/kg instead of the present retail price ($71/kg). Thus, the study successfully demonstrated a zero-waste, self-sustainable, and revenue-generating water treatment process implementing the circular economy framework.

Ultra-high-Q free-space coupling to microtoroid resonators

Whispering gallery mode (WGM) microtoroid resonators are one of the most sensitive biochemical sensors in existence, capable of detecting single molecules. The main barrier for translating these devices out of the laboratory is that light is evanescently coupled into these devices though a tapered optical fiber. This hinders translation of these devices as the taper is fragile, suffers from mechanical vibration, and requires precise positioning. Here, we eliminate the need for an optical fiber by coupling light into and out from a toroid via free-space coupling and monitoring the scattered resonant light. A single long working distance objective lens combined with a digital micromirror device (DMD) was used for light injection, scattered light collection, and imaging. We obtain Q-factors as high as 1.6×108\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$1.6\ imes {10}^{8}$$\\end{document} with this approach. Electromagnetically induced transparency (EIT)-like and Fano resonances were observed in a single cavity due to indirect coupling in free space. This enables improved sensing sensitivity. The large effective coupling area (~10 μm in diameter for numerical aperture = 0.14) removes the need for precise positioning. Sensing performance was verified by combining the system with the frequency locked whispering evanescent resonator (FLOWER) approach to perform temperature sensing experiments. A thermal nonlinear optical effect was examined by tracking the resonance through FLOWER while adjusting the input power. We believe that this work will be a foundation for expanding the implementation of WGM microtoroid resonators to real-world applications.