bluuebunny/crossref_metadata_2025 huggingface dataset:
MK-1 Orthopyroxene—A New Potential Reference Material for In-Situ Microanalysis
Authors: Jia Lihui , Mao Qian , Su Bin , Wu Shitou , Huang Liangliang , Yuan Jiangyan , Zhang Di , Chen Yi
Published: December 2021

Orthopyroxene, an important phase in mantle-derived rocks, has become a powerful tool to unravel mantle nature and magma processes. However, the applications have been hindered by the lag in the development of analytical techniques, such as shortage of reference materials. Orthopyroxene grains derived from an ultramafic intrusion at the Mogok metamorphic belt (Myanmar) were evaluated for the potential use of orthopyroxene as a reference material for in-situ microanalysis. Approximately 20 g of 0.5–3 mm pure orthopyroxene grains were separated under binocular microscope and analyzed using EPMA, LA-ICPMS, and bulk analytical methods (XRD, XRF, and solution-ICPMS) for major and trace elements at four institutions. Eleven core-to-rim profiles carried out using EPMA and twelve core-to-rim profiles determined using LA-ICPMS suggest that MK-1 orthopyroxene grains are sufficiently homogeneous, with RSD < ±2% (1σ) for major elements (Mg, Si, and Fe) and RSD < ±10% (1σ) for trace elements (Na, Al, Ca, Ti, Cr, Co, Zn, Ni, Mn, Sc, and V). In addition, the composition of MK-1 orthopyroxene was also measured by XRF and solution-ICPMS measurements in two different laboratories, to compare with the results measured using EPMA and LA-ICPMS. The results indicated a good agreement with RSE < ±2% (1σ) for major elements and RSE < ±5% (1σ) for most trace elements, except for Na (±9.73%) and Ti (±6.80%). In an overall assessment of these data, MK-1 orthopyroxene can be considered as a reference material for in-situ microanalysis, which would provide solid trace elements data for a better understanding of mantle source and magmatic evolution.
Sulfuric Acid Baking—Water Leaching for Gold Enrichment and Arsenic Removal from Gold Concentrate
Authors: Kim Bongju , Park Chulhyun , Cho Kanghee , Kim Jaehyun , Choi Nagchoul , Lee Soonjae
Published: December 2021

During the roasting of gold concentrate to improve gold recovery, arsenic is released into the air and valuable elements such as Fe, Cu, Zn, and Pb are converted into oxide minerals. In this research, we evaluated the release of As and the loss of valuable metals during the acid baking and hot water leaching processes used for gold concentrate. The acid bake tests were conducted for gold concentrate using an electric furnace by applying various concentrations of H2SO4 solution under different baking times. The water leaching process was enacted using 70 °C water for the baked samples. Chemical and mineral compositions of the raw and treated samples were analyzed using AAS and XRD, respectively. The results show that soluble metal sulfates, such as rhomboclase and mikasite, were formed in the baked samples, and that the leaching of valuable metals (Fe, Cu, Zn, and Pb) was accelerated during the hot water leaching procedure. During acid baking, arsenic was partially removed by volatilization, and the rest of the arsenic-containing minerals were converted to soluble minerals. The soluble arsenic-containing mineral resulted in a dissolution that was 60 times higher than in the roasted sample. The maximum gold grade of solid residues increased up to 33% through the acid baking–water leaching process. It was confirmed that acid baking with H2SO4 prevented As release into the air, as well as the recovery of valuable metals through hot water leaching, such as Fe, Cu, Zn, and Pb, which were formerly discarded in the tailings.
Reactive Transport Modeling of Reflux Dolomitization of Carbonate Platforms: Enlightenment from Yingshan Formation in Shunnan Area, Tarim Basin
Authors: Zhang Wenbo , Wang Guangwei , Cao Zicheng
Published: December 2021

Dolomite plays an important role in carbonate reservoirs. The topography in the study area creates conditions for reflux dolomitization. The northeastward paleogeomorphy during the deposition of the Yingshan Formation was favorable for reflux dolomitization. Furthermore, the petrological and geochemical evidence indicated that the formation of finely crystalline dolomites was penecontemporaneous to sedimentation. The content of powder crystal dolomites increases from grainstone, to packstone, to mudstone. Previous studies only analyzed the origin of dolomites based on traditional geological methods, but did not analyze the spatial influence of reflux dolomitization on the reservoir quality. In this study, the reflux dolomitization of platform carbonate sediments was evaluated using three-dimensional reactive transport models. The sensitivity of dolomitization to a range of intrinsic and extrinsic controls was also explored. The reflux dolomitization involves replacement dolomitization and over-dolomitization. The porosity change is the result of the abundance change of dolomite and anhydrite. The fluid flow pattern in the model is related to the injection rate and geothermal gradient. According to the spatial and temporal change of mineral, ionic concentration, and physical property, the reflux dolomitization could be divided into five stages. From the sensitivity analysis, high permeability promotes dolomitization only in the initial stage, while low permeability and high porosity means stronger dolomitization. Besides, the injection rate, reactive surface area (RSA), geothermal gradient, and brine salinity are all proportional to the dolomitization. Differently from porosity change, the permeability change is concentrated in the upper part of the numerical model. The location of “sweet spot” varies with the locations of change centers of porosity and permeability. In the stage-1 and 4 of dolomitzation, it overlaps with porosity and permeability growth centers. While in the stage-2, 3 and 5, it lies between the porosity and permeability growth/reduction centers.
Application of TD-DFT Theory to Studying Porphyrinoid-Based Photosensitizers for Photodynamic Therapy: A Review
Authors: Drzewiecka-Matuszek Agnieszka , Rutkowska-Zbik Dorota
Published: December 2021

An important focus for innovation in photodynamic therapy (PDT) is theoretical investigations. They employ mostly methods based on Time-Dependent Density Functional Theory (TD-DFT) to study the photochemical properties of photosensitizers. In the current article we review the existing state-of-the-art TD-DFT methods (and beyond) which are employed to study the properties of porphyrinoid-based systems. The review is organized in such a way that each paragraph is devoted to a separate aspect of the PDT mechanism, e.g., correct prediction of the absorption spectra, determination of the singlet–triplet intersystem crossing, and interaction with molecular oxygen. Aspects of the calculation schemes are discussed, such as the choice of the most suitable functional and inclusion of a solvent. Finally, quantitative structure–activity relationship (QSAR) methods used to explore the photochemistry of porphyrinoid-based systems are discussed.
A Survey of Domain Knowledge Elicitation in Applied Machine Learning
Authors: Kerrigan Daniel , Hullman Jessica , Bertini Enrico
Published: December 2021

Eliciting knowledge from domain experts can play an important role throughout the machine learning process, from correctly specifying the task to evaluating model results. However, knowledge elicitation is also fraught with challenges. In this work, we consider why and how machine learning researchers elicit knowledge from experts in the model development process. We develop a taxonomy to characterize elicitation approaches according to the elicitation goal, elicitation target, elicitation process, and use of elicited knowledge. We analyze the elicitation trends observed in 28 papers with this taxonomy and identify opportunities for adding rigor to these elicitation approaches. We suggest future directions for research in elicitation for machine learning by highlighting avenues for further exploration and drawing on what we can learn from elicitation research in other fields.
An 8 MeV Electron Beam Modified In:ZnO Thin Films for CO Gas Sensing towards Low Concentration
Authors: Ani Aninamol , Poornesh P. , Antony Albin , Nagaraja K. K. , Rao Ashok , Hegde Gopalkrishna , Kolesnikov Evgeny , Shchetinin Igor V. , Kulkarni Suresh D. , Petwal Vikash Chandra , Verma Vijay Pal , Dwivedi Jishnu
Published: December 2021

In the present investigation, electron beam-influenced modifications on the CO gas sensing properties of indium doped ZnO (IZO) thin films were reported. Dose rates of 5, 10, and 15 kGy were irradiated to the IZO nano films while maintaining the In doping concentration to be 15 wt%. The wurtzite structure of IZO films is observed from XRD studies post electron beam irradiation, confirming structural stability, even in the intense radiation environment. The surface morphological studies by SEM confirms the granular structure with distinct and sharp grain boundaries for 5 kGy and 10 kGy irradiated films whereas the IZO film irradiated at 15 kGy shows the deterioration of defined grains. The presence of defects viz oxygen vacancies, interstitials are recorded from room temperature photoluminescence (RTPL) studies. The CO gas sensing estimations were executed at an optimized operating temperature of 300 °C for 1 ppm, 2 ppm, 3 ppm, 4 ppm, and 5 ppm. The 10 kGy treated IZO film displayed an enhanced sensor response of 2.61 towards low concentrations of 1 ppm and 4.35 towards 5 ppm. The enhancement in sensor response after irradiation is assigned to the growth in oxygen vacancies and well-defined grain boundaries since the former and latter act as vital adsorption locations for the CO gas.
Ultra-Low Pt Loading in PtCo Catalysts for the Hydrogen Oxidation Reaction: What Role Do Co Nanoparticles Play?
Authors: Anaya-Castro Felipe de Jesús , Beltrán-Gastélum Mara , Morales Soto Omar , Pérez-Sicairos Sergio , Lin Shui Wai , Trujillo-Navarrete Balter , Paraguay-Delgado Francisco , Salazar-Gastélum Luis Javier , Romero-Castañón Tatiana , Reynoso-Soto Edgar , Félix-Navarro Rosa María , Salazar-Gastélum Moisés Israel
Published: December 2021

The effect of the nature of the catalyst on the performance and mechanism of the hydrogen oxidation reaction (HOR) is discussed for the first time in this work. HOR is an anodic reaction that takes place in anionic exchange membrane fuel cells (AEMFCs) and hydrogen pumps (HPs). Among the investigated catalysts, Pt exhibited the best performance in the HOR. However, the cost and the availability limit the usage. Co is incorporated as a co-catalyst due to its oxophylic nature. Five different PtCo catalysts with different Pt loading values were synthesized in order to decrease Pt loading. The catalytic activities and the reaction mechanism were studied via electrochemical techniques, and it was found that both features are a function of Pt loading; low-Pt-loading catalysts (Pt loading < 2.7%) led to a high half-wave potential in the hydrogen oxidation reaction, which is related to higher activation energy and an intermediate Tafel slope value, related to a mixed HOR mechanism. However, catalysts with moderate Pt loading (Pt loading > 3.1%) exhibited lower E1/2 than the other catalysts and exhibited a mechanism similar to that of commercial Pt catalysts. Our results demonstrate that Co plays an active role in the HOR, facilitating Hads desorption, which is the rate-determining step (RDS) in the mechanism of the HOR.
Advances in Plasmonics and Nanophotonics
Authors: Gerislioglu Burak , Ahmadivand Arash
Published: December 2021

Recent developments in subwavelength localization of light have paved the way of novel research directions in the field of optics, plasmonics, and nanophotonics [...]
PCN-224 Nanoparticle/Polyacrylonitrile Nanofiber Membrane for Light-Driven Bacterial Inactivation
Authors: Nie Xiaolin , Wu Shuanglin , Hussain Tanveer , Wei Qufu
Published: December 2021

Increasing issues of pathogen drug resistance and spreading pose a serious threat to the ability to treat common infectious diseases, which encourages people to explore effective technology to meet the challenge. Photodynamic antibacterial inactivation (aPDI) is being explored for inactivating pathogens, which could be used as a novel approach to prevent this threat. Here, porphyrin-embedded MOF material (PCN-224) with photodynamic effect was synthesized, then the PCN-224 nanoparticles (NPs) were embedded into PAN nanofibers with an electrospinning process (PAN-PCN nanofiber membrane). On the one hand, polyacrylonitrile (PAN) nanofibers help to improve the stability of PCN-224 NPs, which could avoid their leakage. On the other, the PAN nanofibers are used as a support material to load bactericidal PCN-224 NPs, realizing recycling after bacterial elimination. An antibacterial photodynamic inactivation (aPDI) study demonstrated that the PAN-PCN 0.6% nanofiber membrane processed 3.00 log unit elimination towards a E. coli bacterial strain and 4.70 log unit towards a S. aureus strain under illumination. A mechanism study revealed that this efficient bacterial elimination was due to singlet oxygen (1O2). Although the materials are highly phototoxic, an MTT assay showed that the as fabricated nanofiber membranes had good biocompatibility in the dark, and the cell survival rates were all above 85%. Taken together, this work provided an application prospect of nanofibers with an aPDI effect to deal with the issues of pathogen drug resistance and spreading.
Eco-Friendly Water-Processable Polyimide Binders with High Adhesion to Silicon Anodes for Lithium-Ion Batteries
Authors: So Yujin , Bae Hyeon-Su , Kang Yi Young , Chung Ji Yun , Park No Kyun , Kim Jinsoo , Jung Hee-Tae , Won Jong Chan , Ryou Myung-Hyun , Kim Yun Ho
Published: December 2021

Silicon is an attractive anode material for lithium-ion batteries (LIBs) because of its natural abundance and excellent theoretical energy density. However, Si-based electrodes are difficult to commercialize because of their significant volume changes during lithiation that can result in mechanical damage. To overcome this limitation, we synthesized an eco-friendly water-soluble polyimide (W-PI) precursor, poly(amic acid) salt (W-PAmAS), as a binder for Si anodes via a simple one-step process using water as a solvent. Using the W-PAmAS binder, a composite Si electrode was achieved by low-temperature processing at 150 °C. The adhesion between the electrode components was further enhanced by introducing 3,5-diaminobenzoic acid, which contains free carboxylic acid (–COOH) groups in the W-PAmAS backbone. The –COOH of the W-PI binder chemically interacts with the surface of Si nanoparticles (SiNPs) by forming ester bonds, which efficiently bond the SiNPs, even during severe volume changes. The Si anode with W-PI binder showed improved electrochemical performance with a high capacity of 2061 mAh g−1 and excellent cyclability of 1883 mAh g−1 after 200 cycles at 1200 mA g−1. Therefore, W-PI can be used as a highly effective polymeric binder in Si-based high-capacity LIBs.
Morphological Studies of Composite Spin Crossover@SiO2 Nanoparticles
Authors: Zan Yue , Salmon Lionel , Bousseksou Azzedine
Published: December 2021

Spin crossover (SCO) iron (II) 1,2,4-triazole-based coordination compounds in the form of composite SCO@SiO2 nanoparticles were prepared using a reverse microemulsion technique. The thickness of the silica shell and the morphology of the as obtained core@shell nanoparticles were studied by modifying the polar phase/surfactant ratio (ω), as well as the quantity and the insertion phase (organic, aqueous and micellar phases) of the tetraethylorthosilicate (TEOS) precursor, the quantity of ammonia and the reaction temperature. The morphology of the nanoparticles was monitored by transmission electron microscopy (TEM/HRTEM) while their composition probed by combined elemental analyses, thermogravimetry and EDX analyses. We report that not only the particle size can be controlled but also the size of the silica shell, allowing for interesting perspectives in post-synthetic modification of the shell. The evolution of the spin crossover properties associated with the change in morphology was investigated by variable temperature optical and magnetic measurements.
Recent Issues and Configuration Factors in Perovskite-Silicon Tandem Solar Cells towards Large Scaling Production
Authors: Elsmani Mohammed Islam , Fatima Noshin , Jallorina Michael Paul A. , Sepeai Suhaila , Su’ait Mohd Sukor , Ahmad Ludin Norasikin , Mat Teridi Mohd Asri , Sopian Kamaruzzaman , Ibrahim Mohd Adib
Published: December 2021

The unprecedented development of perovskite-silicon (PSC-Si) tandem solar cells in the last five years has been hindered by several challenges towards industrialization, which require further research. The combination of the low cost of perovskite and legacy silicon solar cells serve as primary drivers for PSC-Si tandem solar cell improvement. For the perovskite top-cell, the utmost concern reported in the literature is perovskite instability. Hence, proposed physical loss mechanisms for intrinsic and extrinsic instability as triggering mechanisms for hysteresis, ion segregation, and trap states, along with the latest proposed mitigation strategies in terms of stability engineering, are discussed. The silicon bottom cell, being a mature technology, is currently facing bottleneck challenges to achieve power conversion efficiencies (PCE) greater than 26.7%, which requires more understanding in the context of light management and passivation technologies. Finally, for large-scale industrialization of the PSC-Si tandem solar cell, the promising silicon wafer thinning, and large-scale film deposition technologies could cause a shift and align with a more affordable and flexible roll-to-roll PSC-Si technology. Therefore, this review aims to provide deliberate guidance on critical fundamental issues and configuration factors in current PSC-Si tandem technologies towards large-scale industrialization. to meet the 2031 PSC-Si Tandem road maps market target.
Facilely Flexible Imprinted Hemispherical Cavity Array for Effective Plasmonic Coupling as SERS Substrate
Authors: Xu Jihua , Li Jinmeng , Guo Guangxu , Zhao Xiaofei , Li Zhen , Xu Shicai , Li Chonghui , Man Baoyuan , Yu Jing , Zhang Chao
Published: December 2021

The focusing field effect excited by the cavity mode has a positive coupling effect with the metal localized surface plasmon resonance (LSPR) effect, which can stimulate a stronger local electromagnetic field. Therefore, we combined the self-organizing process for component and array manufacturing with imprinting technology to construct a cheap and reproducible flexible polyvinyl alcohol (PVA) nanocavity array decorating with the silver nanoparticles (Ag NPs). The distribution of the local electromagnetic field was simulated theoretically, and the surface-enhanced Raman scattering (SERS) performance of the substrate was evaluated experimentally. The substrate shows excellent mechanical stability in bending experiments. It was proved theoretically and experimentally that the substrate still provides a stable signal when the excited light is incident from different angles. This flexible substrate can achieve low-cost, highly sensitive, uniform and conducive SERS detection, especially in situ detection, which shows a promising application prospect in food safety and biomedicine.
Morphology-Dependent Room-Temperature Ferromagnetism in Undoped ZnO Nanostructures
Authors: Ren Hongtao , Xiang Gang
Published: December 2021

Since Dietl et al. predicted that Co-doped ZnO may show room-temperature ferromagnetism (RTFM) in 2000, researchers have focused on the investigation of ferromagnetic ZnO doped with various transition metals. However, after decades of exploration, it has been found that undoped ZnO nanostructures can also show RTFM, which in general is dependent on ZnO morphologies. Here, we will give an overall review on undoped ZnO nanomaterials with RTFM. The advanced strategies to achieve multidimensional (quasi-0D, 1D, 2D, and 3D) ferromagnetic ZnO nanostructures and the mechanisms behind RTFM are systematically presented. We have successfully prepared ferromagnetic nanostructures, including thin films, horizontal arrays and vertical arrays. The existing challenges, including open questions about quantum-bound ZnO nanostructures, are then discussed.
Atomic Defect Induced Saturable Absorption of Hexagonal Boron Nitride in Near Infrared Band for Ultrafast Lasing Applications
Authors: Cheng Chen , Li Ziqi , Dong Ningning , Li Rang , Wang Jun , Chen Feng
Published: December 2021

Defect-induced phenomena in 2D materials has received increasing interest among researchers due to the novel properties correlated with precise modification of materials. We performed a study of the nonlinear saturable absorption of the boron-atom-vacancy defective hexagonal boron nitride (h-BN) thin film at a wavelength of ~1 μm and its applications in ultrafast laser generation. The h-BN is with wide band gap of ~6 eV. Our investigation shows that the defective h-BN has a wide absorption band from visible to near infrared regimes. First-principle calculations based on density functional theory (DFT) indicate that optical property changes may be attributed to the boron-vacancy-related defects. The photoluminescence spectrum shows a strong emission peak at ~1.79 eV. The ultrafast Z-scan measurement shows saturable absorbance response has been detected for the defective h-BN with saturation intensity of ~1.03 GW/cm2 and modulation depth of 1.1%. In addition, the defective h-BN has been applied as a new saturable absorber (SA) to generate laser pulses through the passively Q-switched mode-locking configuration. Based on a Nd:YAG waveguide platform, 8.7 GHz repetition rate and 55 ps pulse duration of the waveguide laser have been achieved. Our results suggest potential applications of defective h-BN for ultrafast lasing and integrated photonics.
Screen-Printed Electrode Surface Modification with NiCo2O4/RGO Nanocomposite for Hydroxylamine Detection
Authors: Tajik Somayeh , Beitollahi Hadi , Ahmadi Sayed ali , Askari Mohammad Bagher , Di Bartolomeo Antonio
Published: December 2021

We developed a novel hydroxylamine sensor through the surface modification of screen-printed electrode (SPE) with NiCo2O4 nanoparticles/reduced graphene oxide (RGO) nanocomposite (NiCo2O4/RGO/SPE). We assessed the electrochemical response of hydroxylamine on the as-fabricated sensor, confirming the high electrocatalytic impact of hydroxylamine oxidation. The electrode produced sensitively responded to hydroxylamine under optimized conditions, with a low limit of detection (2.0 nM) and broad linear dynamic range (0.007–385.0 µM). The presence of NiCo2O4 combined with the modification of RGO resulted in sensitive detection and signal amplification of hydroxylamine oxidation. The proposed sensor was used to determine the existence of hydroxylamine in water samples.
Facile Synthesis of Zn-Co-S Nanostrip Cluster Arrays on Ni Foam for High-Performance Hybrid Supercapacitors
Authors: Vijayakumar Subbukalai , Dhakal Ganesh , Kim Soo-Hyun , Lee Jintae , Lee Yong Rok , Shim Jae-Jin
Published: December 2021

Mixed metal sulfides exhibit outstanding electrochemical performance compared to single metal sulfides and mixed metal oxides because of their richer redox reactions and high electronic conductivity. In the present study, Zn-Co-S nanostrip cluster arrays were formed from ZnCo2O4 grown on Ni foam by an anion exchange reaction using a two-step hydrothermal process. Morphological characterization confirmed that the Zn-Co-S nanostrip cluster arrays had grown homogeneously on the skeleton of the 3D Ni foam. The length of the nanostrip was approximately 8 µm, and the width ranged from 600 to 800 nm. The Ni foam-supported Zn-Co-S nanostrip cluster arrays were assessed directly for electrochemical supercapacitor applications. Compared to ZnCo2O4, the Zn-Co-S electrode exhibited a three-fold higher specific capacity of 830 C g−1 at a specific current of 2.0 A g−1. The higher polarizability, lower electro-negativity, and larger size of the S2− ion played an important role in substituting oxygen with sulfur, which enhanced the performance. The Zn-Co-S//AC hybrid device delivered a maximum specific energy of 19.0 Wh kg−1 at a specific power of 514 W kg−1. The remarkable performance of Zn-Co-S nanostrip cluster arrays highlights their potential as a positive electrode for hybrid supercapacitor applications.
Pulsed Laser Deposition of CsPbBr3 Films: Impact of the Composition of the Target and Mass Distribution in the Plasma Plume
Authors: Cesaria Maura , Mazzeo Marco , Quarta Gianluca , Aziz Muhammad Rizwan , Nobile Concetta , Carallo Sonia , Martino Maurizio , Calcagnile Lucio , Caricato Anna Paola
Published: December 2021

All-inorganic cesium lead bromine (CsPbBr3) perovskites have gained a tremendous potential in optoelectronics due to interesting photophysical properties and much better stability than the hybrid counterparts. Although pulsed laser deposition (PLD) is a promising alternative to solvent-based and/or thermal deposition approaches due to its versatility in depositing multi-elemental materials, deep understanding of the implications of both target composition and PLD mechanisms on the properties of CsPbBr3 films is still missing. In this paper, we deal with thermally assisted preparation of mechano-chemically synthesized CsPbBr3 ablation targets to grow CsPbBr3 films by PLD at the fluence 2 J/cm2. We study both Cs rich- and stoichiometric PbBr2-CsBr mixture-based ablation targets and point out compositional deviations of the associated films resulting from the mass distribution of the PLD-generated plasma plume. Contrary to the conventional meaning that PLD guarantees congruent elemental transfer from the target to the substrate, our study demonstrates cation off-stoichiometry of PLD-grown CsPbBr3 films depending on composition and thermal treatment of the ablation target. The implications of the observed enrichment in the heavier element (Pb) and deficiency in the lighter element (Br) of the PLD-grown films are discussed in terms of optical response and with the perspective of providing operative guidelines and future PLD-deposition strategies of inorganic perovskites.
Solidification Enhancement in a Multi-Tube Latent Heat Storage System for Efficient and Economical Production: Effect of Number, Position and Temperature of the Tubes
Authors: Li Min , Mahdi Jasim M. , Mohammed Hayder I. , Bokov Dmitry Olegovich , Mahmoud Mustafa Z. , Naghizadeh Ali , Talebizadehsardari Pouyan , Yaïci Wahiba
Published: December 2021

Thermal energy storage is an important component in energy units to decrease the gap between energy supply and demand. Free convection and the locations of the tubes carrying the heat-transfer fluid (HTF) have a significant influence on both the energy discharging potential and the buoyancy effect during the solidification mode. In the present study, the impact of the tube position was examined during the discharging process. Liquid-fraction evolution and energy removal rate with thermo-fluid contour profiles were used to examine the performance of the unit. Heat exchanger tubes are proposed with different numbers and positions in the unit for various cases including uniform and non-uniform tubes distribution. The results show that moving the HTF tubes to medium positions along the vertical direction is relatively better for enhancing the solidification of PCM with multiple HTF tubes. Repositioning of the HTF tubes on the left side of the unit can slightly improve the heat removal rate by about 0.2 in the case of p5-u-1 and decreases by 1.6% in the case of p5-u-2. It was found also that increasing the distance between the tubes in the vertical direction has a detrimental effect on the PCM solidification mode. Replacing the HTF tubes on the left side of the unit negatively reduces the heat removal rate by about 1.2 and 4.4%, respectively. Further, decreasing the HTF temperature from 15 °C to 10 and 5 °C can increase the heat removal rate by around 7 and 16%, respectively. This paper indicates that the specific concern to the HTF tube arrangement should be made to improve the discharging process attending free convection impact in phase change heat storage.
Hydrophilic and Hydrophobic Nanostructured Copper Surfaces for Efficient Pool Boiling Heat Transfer with Water, Water/Butanol Mixtures and Novec 649
Authors: Može Matic , Vajc Viktor , Zupančič Matevž , Golobič Iztok
Published: December 2021

Increasing heat dissipation requirements of small and miniature devices demands advanced cooling methods, such as application of immersion cooling via boiling heat transfer. In this study, functionalized copper surfaces for enhanced heat transfer are developed and evaluated. Samples are functionalized using a chemical oxidation treatment with subsequent hydrophobization of selected surfaces with a fluorinated silane. Pool boiling tests with water, water/1-butanol mixture with self-rewetting properties and a novel dielectric fluid with low GWP (Novec™ 649) are conducted to evaluate the boiling performance of individual surfaces. The results show that hydrophobized functionalized surfaces covered by microcavities with diameters between 40 nm and 2 µm exhibit increased heat transfer coefficient (HTC; enhancements up to 120%) and critical heat flux (CHF; enhancements up to 64%) values in comparison with the untreated reference surface, complemented by favorable fabrication repeatability. Positive surface stability is observed in contact with water, while both the self-rewetting fluids and Novec™ 649 gradually degrade the boiling performance and in some cases also the surface itself. The use of water/1-butanol mixtures in particular results in surface chemistry and morphology changes, as observed using SEM imaging and Raman spectroscopy. This seems to be neglected in the available literature and should be focused on in further studies.
Epitaxial Growth of Uniform Single-Layer and Bilayer Graphene with Assistance of Nitrogen Plasma
Authors: Jin Shaoen , Zong Junyu , Chen Wang , Tian Qichao , Qiu Xiaodong , Liu Gan , Zheng Hang , Xi Xiaoxiang , Gao Libo , Wang Can , Zhang Yi
Published: December 2021

Graphene was reported as the first-discovered two-dimensional material, and the thermal decomposition of SiC is a feasible route to prepare graphene films. However, it is difficult to obtain a uniform single-layer graphene avoiding the coexistence of multilayer graphene islands or bare substrate holes, which give rise to the degradation of device performance and becomes an obstacle for the further applications. Here, with the assistance of nitrogen plasma, we successfully obtained high-quality single-layer and bilayer graphene with large-scale and uniform surface via annealing 4H-SiC(0001) wafers. The highly flat surface and ordered terraces of the samples were characterized using in situ scanning tunneling microscopy. The Dirac bands in single-layer and bilayer graphene were measured using angle-resolved photoemission spectroscopy. X-ray photoelectron spectroscopy combined with Raman spectroscopy were used to determine the composition of the samples and to ensure no intercalation or chemical reaction of nitrogen with graphene. Our work has provided an efficient way to obtain the uniform single-layer and bilayer graphene films grown on a semiconductive substrate, which would be an ideal platform for fabricating two-dimensional devices based on graphene.
Li2ZrO3-Coated Monocrystalline LiAl0.06Mn1.94O4 Particles as Cathode Materials for Lithium-Ion Batteries
Authors: Li Chunliu , Zhao Banglei , Yang Junfeng , Zhang Linchao , Fang Qianfeng , Wang Xianping
Published: December 2021

Li2ZrO3-coated and Al-doped micro-sized monocrystalline LiMn2O4 powder is synthesized through solid-state reaction, and the electrochemical performance is investigated as cathode materials for lithium-ion batteries. It is found that Li2ZrO3-coated LiAl0.06Mn1.94O4 delivers a discharge capacity of 110.90 mAhg−1 with 94% capacity retention after 200 cycles at room temperature and a discharge capacity of 104.4 mAhg−1 with a capacity retention of 87.8% after 100 cycles at 55 °C. Moreover, Li2ZrO3-coated LiAl0.06Mn1.94O4 could retain 87.5% of its initial capacity at 5C rate. This superior cycling and rate performance can be greatly contributed to the synergistic effect of Al-doping and Li2ZrO3-coating.
Palygorskite-Based Organic–Inorganic Hybrid Nanocomposite for Enhanced Antibacterial Activities
Authors: Hui Aiping , Yang Fangfang , Yan Rui , Kang Yuru , Wang Aiqin
Published: December 2021

A synergistic antibacterial strategy is effective in enhancing the antibacterial efficacy of a single antibacterial material. Plant essential oils (PEOs) are safe antibacterial agents. However, some of their characteristics such as intense aroma, volatility, and poor thermal stability limit their antibacterial activity and applications. In this paper, five kinds of PEOs were incorporated onto ZnO/palygorskite (ZnO/PAL) nanoparticles by a simple adsorption process to form organic–inorganic nanocomposites (PEOs/ZnO/PAL) with excellent antibacterial properties. TEM and SEM analyses demonstrated that ZnO nanoparticles uniformly anchored onto the surface of rod-like PAL, and that the structure of ZnO/PAL maintained after the incorporation of ZnO nanoparticles and PEOs. It was found that carvacrol/ZnO/palygorskite (CAR/ZnO/PAL) exhibited higher antibacterial activities than other PEOs/ZnO/PAL nanocomposites, with minimum inhibitory concentration (MIC) values of 0.5 mg/mL and 1.5 mg/mL against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. Moreover, the antibacterial efficiency of CAR/ZnO/PAL nanocomposites was superior to that of ZnO/PAL and pure CAR, demonstrating the synergistic effect that occurs in the combined system. PAL serving as a carrier for the combination of organic PEOs and ZnO nanoparticles is an effective strategy for enhanced, clay-based, organic–inorganic hybrid antibacterial nanocomposites.
Enhancing Magnetic Hyperthermia Nanoparticle Heating Efficiency with Non-Sinusoidal Alternating Magnetic Field Waveforms
Authors: Zeinoun Michael , Domingo-Diez Javier , Rodriguez-Garcia Miguel , Garcia Oscar , Vasic Miroslav , Ramos Milagros , Serrano Olmedo José Javier
Published: December 2021

For decades now, conventional sinusoidal signals have been exclusively used in magnetic hyperthermia as the only alternating magnetic field waveform to excite magnetic nanoparticles. However, there are no theoretical nor experimental reasons that prevent the use of different waveforms. The only justifiable motive behind using the sinusoidal signal is its availability and the facility to produce it. Following the development of a configurable alternating magnetic field generator, we aim to study the effect of various waveforms on the heat production effectiveness of magnetic nanoparticles, seeking to prove that signals with more significant slope values, such as the trapezoidal and almost-square signals, allow the nanoparticles to reach higher efficiency in heat generation. Furthermore, we seek to point out that the nanoparticle power dissipation is dependent on the waveform’s slope and not only the frequency, magnetic field intensity and the nanoparticle size. The experimental results showed a remarkably higher heat production performance of the nanoparticles when exposed to trapezoidal and almost-square signals than conventional sinusoidal signals. We conclude that the nanoparticles respond better to the trapezoidal and almost-square signals. On the other hand, the experimental results were used to calculate the normalized power dissipation value and prove its dependency on the slope. However, adjustments are necessary to the coil before proceeding with in vitro and in vivo studies to handle the magnetic fields required.
Photocatalytic Activity of Revolutionary Galaxaura elongata, Turbinaria ornata, and Enteromorpha flexuosa’s Bio-Capped Silver Nanoparticles for Industrial Wastewater Treatment
Authors: Abdel Azeem Manal N. , Hassaballa Safwat , Ahmed Osama M. , Elsayed Khaled N. M. , Shaban Mohamed
Published: December 2021

More suitable wastewater treatment schemes need to be developed to get rid of harmful dyes and pigments before they are discharged, primarily from apparel and textile factories, into water bodies. Silver nanoparticles (Ag-NPs) are very effective, reductive nanocatalysts that can degrade many organic dyes. In this study, Ag-NPs are stabilized and capped with bioactive compounds such as Galaxaura elongata, Turbinaria ornata, and Enteromorpha flexuosa from marine macroalgae extracts to produce Ag[GE], Ag[TE], and Ag[EE] NPs. The reduction of Ag ions and the production of Ag[GE], Ag[TE], and Ag[EE] NPs have been substantiated by UV–Vis spectroscopy, SEM, EDX, and XRD tests. The NPs are sphere and crystalline shaped in nature with dimensions ranging from 20 to 25 nm. The biosynthesized Ag[GE], Ag[TE], Ag[EE] NPs were applied to photodegrade hazardous pigments such as methylene blue, Congo red, safranine O, and crystal violet under sunlight irradiation. In addition to the stability analysis, various experimental parameters, including dye concentration, exposure period, photocatalyst dose, and temperature, were optimized to achieve 100% photodegradation of the dyes. Moreover, the thermodynamic and kinetic parameters were calculated and the impact of scavengers on the photocatalytic mechanism was also investigated.
Direct Fabrication of CsPbxMn1−x(Br,Cl)3 Thin Film by a Facile Solution Spraying Approach
Authors: Sun Yu , Chen Jin , Wang Fengchao , Yin Yi , Jin Yan , Wang Jun , Peng Xiaogai , Han Ruiyi , Zhang Canyun , Kong Jinfang , Yang Jing
Published: December 2021

Nowadays, Mn-doping is considered as a promising dissolution for the heavy usage of toxic lead in CsPbX3 perovskite material. Interestingly, Mn-doping also introduces an additional photoluminescence band, which is favorable to enrich the emission gamut of this cesium lead halide. Here, a solution spraying strategy was employed for the direct preparation of CsPbxMn1−x(Br,Cl)3 film through MnCl2 doping in host CsPbBr3 material. The possible fabrication mechanism of the provided approach and the dependences of material properties on Mn-doping were investigated in detail. As the results shown, Pb was partially substituted by Mn as expected. With the ratio of PbBr2:MnCl2 increasing from 3:0 to 1:1, the obtained film separately featured green, cyan, orange-red and pink-red emission, which was caused by the energy transferring process. Moreover, the combining energy of Cs, Pb, and Mn gradually red-shifted resulted from the formation of Cs-Cl, Pb-Cl and Mn-Br coordination bonding as MnCl2 doping increased. In addition, the weight of short decay lifetime of prepared samples increased with the doping rising, which indicated a better exciton emission and less defect-related transition. The aiming of current work is to provide a new possibility for the facile preparation of Mn-doping CsPbX3 film material.
Anisotropy of 3D Columnar Coatings in Mid-Infrared Spectral Range
Authors: Grineviciute Lina , Ng Soon Hock , Han Molong , Moein Tania , Anand Vijayakumar , Katkus Tomas , Ryu Meguya , Morikawa Junko , Tobin Mark J. , Vongsvivut Jitraporn , Tolenis Tomas , Juodkazis Saulius
Published: December 2021

Polarisation analysis in the mid-infrared fingerprint region was carried out on thin (∼1 μm) Si and SiO2 films evaporated via glancing angle deposition (GLAD) method at 70∘ to the normal. Synchrotron-based infrared microspectroscopic measurements were carried out on the Infrared Microspectroscopy (IRM) beamline at Australian Synchrotron. Specific absorption bands, particularly Si-O-Si stretching vibration, was found to follow the angular dependence of ∼cos2θ, consistent with the absorption anisotropy. This unexpected anisotropy stems from the enhanced absorption in nano-crevices, which have orientation following the cos2θ angular dependence as revealed by Fourier transforming the image of the surface of 3D columnar films and numerical modeling of light field enhancement by sub-wavelength nano-crevices.
A Strategic Approach to Use Upcycled Si Nanomaterials for Stable Operation of Lithium-Ion Batteries
Authors: Kim Junghwan , Kwon Jisoo , Kim Min Ji , O Min Ju , Jung Dae Soo , Roh Kwang Chul , Jang Jihyun , Kim Patrick Joohyun , Choi Junghyun
Published: December 2021

Silicon, as a promising next-generation anode material, has drawn special attention from industries due to its high theoretical capacity (around 3600 mAh g−1) in comparison with conventional electrodes, e.g., graphite. However, the fast capacity fading resulted by a large volume change hinders the pragmatic use of Si anodes for lithium ion batteries. In this work, we propose an efficient strategy to improve the cyclability of upcycled Si nanomaterials through a simple battery operation protocol. When the utilization degree of Si electrodes was decreased, the electrode deformation was significantly alleviated. This directly led to an excellent electrochemical performance over 100 cycles. In addition, the average charge (delithation) voltage was shifted to a lower voltage, when the utilization degree of electrodes was controlled. These results demonstrated that our strategic approach would be an effective way to enhance the electrochemical performance of Si anodes and improve the cost-effectiveness of scaling-up the decent nanostructured Si material.
Biocompatibility Testing of Liquid Metal as an Interconnection Material for Flexible Implant Technology
Authors: Foremny Katharina , Nagels Steven , Kreienmeyer Michaela , Doll Theodor , Deferme Wim
Published: December 2021

Galinstan, a liquid metal at room temperature, is a promising material for use in flexible electronics. Since it has been successfully integrated in devices for external use, e.g., as stretchable electronic skin in tactile sensation, the possibility of using galinstan for flexible implant technology comes to mind. Usage of liquid metals in a flexible implant would reduce the risk of broken conductive pathways in the implants and therefore reduce the possibility of implant failure. However, the biocompatibility of the liquid metal under study, i.e., galinstan, has not been proven in state-of-the-art literature. Therefore, in this paper, a material combination of galinstan and silicone rubber is under investigation regarding the success of sterilization methods and to establish biocompatibility testing for an in vivo application. First cell biocompatibility tests (WST-1 assays) and cell toxicity tests (LDH assays) show promising results regarding biocompatibility. This work paves the way towards the successful integration of stretchable devices using liquid metals embedded in a silicone rubber encapsulant for flexible surface electro-cortical grid arrays and other flexible implants.
Gold Nanostars Embedded in PDMS Films: A Photothermal Material for Antibacterial Applications
Authors: Toci Gemma , Olgiati Francesca , Pallavicini Piersandro , Diaz Fernandez Yuri Antonio , De Vita Lorenzo , Dacarro Giacomo , Grisoli Pietro , Taglietti Angelo
Published: December 2021

Bacteria infections and related biofilms growth on surfaces of medical devices are a serious threat to human health. Controlled hyperthermia caused by photothermal effects can be used to kill bacteria and counteract biofilms formation. Embedding of plasmonic nano-objects like gold nanostars (GNS), able to give an intense photothermal effect when irradiated in the NIR, can be a smart way to functionalize a transparent and biocompatible material like polydimethylsiloxane (PDMS). This process enables bacteria destruction on surfaces of PDMS-made medical surfaces, an action which, in principle, can also be exploited in subcutaneous devices. We prepared stable and reproducible thin PDMS films containing controllable quantities of GNS, enabling a temperature increase that can reach more than 40 degrees. The hyperthermia exerted by this hybrid material generates an effective thermal microbicidal effect, killing bacteria with a near infrared (NIR) laser source with irradiance values that are safe for skin.
Synthesis and Luminescent Properties of Carbon Nanodots Dispersed in Nanostructured Silicas
Authors: Vasin Andrii , Kysil Dmytro , Rusavsky Andriy , Isaieva Oksana , Zaderko Alexander , Nazarov Alexei , Lysenko Volodymyr
Published: December 2021

Luminescent carbon nanoparticles are a relatively new class of luminescent materials that have attracted the increasing interest of chemists, physicists, biologists and engineers. The present review has a particular focus on the synthesis and luminescent properties of carbon nanoparticles dispersed inside nanostructured silica of different natures: oxidized porous silicon, amorphous thin films, nanopowders, and nanoporous sol–gel-derived ceramics. The correlations of processing conditions with emission/excitation spectral properties, relaxation kinetics, and photoluminescence photodegradation behaviors are analyzed. Following the evolution of the photoluminescence (PL) through the “from-bottom-to-up” synthesis procedure, the transformation of molecular-like ultraviolet emission of organic precursor into visible emission of carbon nanoparticles is demonstrated. At the end of the review, a novel method for the synthesis of luminescent and transparent composites, in form of nanoporous silica filled with luminescent carbon nanodots, is presented. A prototype of white light emitting devices, constructed on the basis of such luminophores and violet light emitting diodes, is demonstrated.
The Role of Diet, Alcohol, BMI, and Physical Activity in Cancer Mortality: Summary Findings of the EPIC Study
Authors: Molina-Montes Esther , Ubago-Guisado Esther , Petrova Dafina , Amiano Pilar , Chirlaque María-Dolores , Agudo Antonio , Sánchez María-José
Published: December 2021

Evidence on the impact of diet, alcohol, body-mass index (BMI), and physical activity on mortality due to cancer and other cancer-related outcomes is still scarce. Herein, we reviewed the contribution of the European Prospective Investigation into Cancer and Nutrition (EPIC) study to the current state of the art on the role of these factors in cancer mortality. We identified 45 studies using a rapid systematic review methodology. Dietary factors associated with reduced cancer mortality included raw vegetable intake; dietary fiber intake; the Mediterranean diet; other dietary scores; other diet patterns including low meat eaters, vegetarians/vegans, or fish eaters; dietary intake (or biomarkers) of some vitamins (e.g., vitamin D, vitamin K2, or Vitamin C); and intake of lignans. Physical activity and following healthy lifestyle recommendations also reduced cancer mortality risk. In contrast, dietary factors associated with higher cancer mortality risk included poor diet quality, consumption of alcohol and soft drinks including juice, and, to a lesser extent, intake of some fatty acids. Excess weight and obesity also increased the risk of cancer mortality. The EPIC study holds valuable information on diet and lifestyle factors and offers a unique opportunity to identify key diet-related factors for cancer mortality prevention.