bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanofiltration Membranes Formed through Interfacial Polymerization Involving Cycloalkane Amine Monomer and Trimesoyl Chloride Showing Some Tolerance to Chlorine during Dye Desalination
Authors: Ang Micah Belle Marie Yap , Wu Yi-Ling , Chu Min-Yi , Wu Ping-Han , Chiao Yu-Hsuan , Millare Jeremiah C. , Huang Shu-Hsien , Tsai Hui-An , Lee Kueir-Rarn
Published: March 2022

Wastewater effluents containing high concentrations of dyes are highly toxic to the environment and aquatic organisms. Recycle and reuse of both water and dye in textile industries can save energy and costs. Thus, new materials are being explored to fabricate highly efficient nanofiltration membranes for fulfilling industrial needs. In this work, three diamines, 1,4-cyclohexanediamine (CHD), ethylenediamine (EDA), and p-phenylenediamine (PPD), are reacted with TMC separately to fabricate a thin film composite polyamide membrane for dye desalination. Their chemical structures are different, with the difference located in the middle of two terminal amines. The surface morphology, roughness, and thickness of the polyamide layer are dependent on the reactivity of the diamines with TMC. EDA has a short linear alkane chain, which can easily react with TMC, forming a very dense selective layer. CHD has a cyclohexane ring, making it more sterically hindered than EDA. As such, CHD’s reaction with TMC is slower than EDA’s, leading to a thinner polyamide layer. PPD has a benzene ring, which should make it the most sterically hindered structure; however, its benzene ring has a pi-pi interaction with TMC that can facilitate a faster reaction between PPD and TMC, leading to a thicker polyamide layer. Among the TFC membranes, TFCCHD exhibited the highest separation efficiency (pure water flux = 192.13 ± 7.11 L∙m−2∙h−1, dye rejection = 99.92 ± 0.10%, and NaCl rejection = 15.46 ± 1.68% at 6 bar and 1000 ppm salt or 50 ppm of dye solution). After exposure at 12,000 ppm∙h of active chlorine, the flux of TFCCHD was enhanced with maintained high dye rejection. Therefore, the TFCCHD membrane has a potential application for dye desalination process.
Metal-Coordinated Nanofiltration Membranes Constructed on Metal Ions Blended Support toward Enhanced Dye/Salt Separation and Antifouling Performances
Authors: Fang Xiaofeng , Wei Shihao , Liu Shuai , Li Ruo , Zhang Ziyi , Liu Yanbiao , Zhang Xingran , Lou Mengmeng , Chen Gang , Li Fang
Published: March 2022

Metal-phenol coordination is a widely used method to prepare nanofiltration membrane. However, the facile, controllable and scaled fabrication remains a great challenge. Herein, a novel strategy was developed to fabricate a loose nanofiltration membrane via integrating blending and interfacial coordination strategy. Specifically, iron acetylacetonate was firstly blended in Polyether sulfone (PES) substrate via non-solvent induced phase separation (NIPS), and then the loose selective layer was formed on the membrane surface with tannic acid (TA) crosslinking reaction with Fe3+. The surface properties, morphologies, permeability and selectivity of the membranes were carefully investigated. The introduction of TA improved the surface hydrophilicity and negative charge. Moreover, the thickness of top layer increased about from ~30 nm to 119 nm with the increase of TA assembly time. Under the optimum preparation condition, the membrane with assembly 3 h (PES/Fe-TA3h) showed pure water flux of 175.8 L·m−2·h−1, dye rejections of 97.7%, 97.1% and 95.0% for Congo red (CR), Methyl blue (MB) and Eriochrome Black T (EBT), along with a salt penetration rate of 93.8%, 95.1%, 97.4% and 98.1% for Na2SO4, MgSO4, NaCl and MgCl2 at 0.2 MPa, respectively. Both static adhesion tests and dynamic fouling experiments implied that the TA modified membranes showed significantly reduced adsorption and high FRR for the dye solutions separation. The PES/Fe-TA3h membrane exhibited high FRR of 90.3%, 87.5% and 81.6% for CR, EBT and MB in the fouling test, stable CR rejection (>97.2%) and NaCl permeation (>94.6%) in 24 h continuous filtration test. The combination of blending and interfacial coordination assembly method could be expected to be a universal way to fabricate the loose nanofiltration membrane for effective fractionation of dyes and salts in the saline textile wastewater.
Electro-Driven Materials and Processes for Lithium Recovery—A Review
Authors: Siekierka Anna , Bryjak Marek , Razmjou Amir , Kujawski Wojciech , Nikoloski Aleksandar N. , Dumée Ludovic F.
Published: March 2022

The mass production of lithium-ion batteries and lithium-rich e-products that are required for electric vehicles, energy storage devices, and cloud-connected electronics is driving an unprecedented demand for lithium resources. Current lithium production technologies, in which extraction and purification are typically achieved by hydrometallurgical routes, possess strong environmental impact but are also energy-intensive and require extensive operational capabilities. The emergence of selective membrane materials and associated electro-processes offers an avenue to reduce these energy and cost penalties and create more sustainable lithium production approaches. In this review, lithium recovery technologies are discussed considering the origin of the lithium, which can be primary sources such as minerals and brines or e-waste sources generated from recycling of batteries and other e-products. The relevance of electro-membrane processes for selective lithium recovery is discussed as well as the potential and shortfalls of current electro-membrane methods.
Influence of Deposition Modes and Thermal Annealing on Residual Stresses in Magnetron-Sputtered YSZ Membranes
Authors: Solovyev Andrey , Rabotkin Sergey , Shipilova Anna , Agarkov Dmitrii , Burmistrov Ilya , Shmakov Alexander
Published: March 2022

Thin-film electrolyte made of 8-mol% yttria stabilized zirconia (8YSZ) for solid oxide fuel cells (SOFCs) was fabricated on anode substrates using reactive magnetron sputtering of Zr-Y targets in a mixture of Ar and O2 gases. The deposition of 4–6 µm thin-film electrolyte was in the transition or oxide modes differing by the oxygen concentration in the sputtering atmosphere. The half-cell bending of the anode-supported SOFCs was measured to determine the residual stresses in the electrolyte films after the deposition and thermal annealing in air. The dependences were studied between the deposition modes, residual stresses in the films, and the SOFC performance. At 800 °C, the maximum power density of SOFCs ranged between 0.58 and 1.2 W/cm2 depending on the electrolyte deposition mode. Scanning electron microscopy was carried out to investigate the surface morphology and structure of the YSZ electrolyte films after thermal annealing. Additionally, an X-ray diffraction analysis of the YSZ electrolyte films was conducted for the synchrotron radiation beam during thermal annealing at different temperatures up to 1300 °C. It was found that certain deposition modes provide the formation of the YSZ electrolyte films with acceptable residual stresses (<1 GPa) at room temperature, including films deposited on large area anodes (100 × 100 mm2).
Research Progress of Polyvinyl Alcohol Water-Resistant Film Materials
Authors: Liu Baodong , Zhang Jianhua , Guo Hongge
Published: March 2022

Polyvinyl alcohol (PVA) is one of the few biodegradable synthetic resins from petroleum-based sources that can alleviate white pollution in the environment. PVA film materials have excellent properties, such as high barrier, high transparency, high toughness, biocompatibility, and adjustable water solubility. However, due to the presence of hydrophilic hydroxyl groups in the side chain of PVA resin, when PVA film is placed in a humid or water environment, swelling or even dissolution will occur, which greatly limits its application. Therefore, it is necessary to modify PVA resin to improve water resistance without reducing other properties and can also impart various functionalities to it, thereby widening the application range. This paper reviews the water-resistant modification methods of polyvinyl alcohol and the application of water-resistant films and provides an outlook on the development trend of PVA water-resistant films.
Young People and the Labor Market—Challenges and Opportunities: An Introduction
Authors: Marelli Enrico , Signorelli Marcello
Published: March 2022

The position of young people in the labor market is disappointing in most countries worldwide, as shown by the generally scanty labor market indices: high rates of unemployment and NEET (not in education, employment or training), and low activity and employment rates [...]
Study of Comminution Kinetics in an Electrofragmentation Lab-Scale Device
Authors: Llera Angel R. , Díaz Ana , Pedrayes Francisco J. , Menéndez-Aguado Juan M. , Melero Manuel G.
Published: March 2022

A significant challenge in mineral raw materials comminution is the improvement of process energy efficiency. Conventional comminution techniques, although globally used, are far from being considered power-efficient. The use of high-voltage electric pulses in comminution is a concept that is worthy of study; despite its lack of industrial-scale validation after several decades of lab-scale research, it seems promising as a pretreatment leading to energy savings. In this article, the Cumulative Kinetic Model methodology is adapted to model the comminution effect in an electrofragmentation device, and study a dunite rock ore. The results show that product particle size distribution (PSD) can be predicted with reasonable accuracy using the proposed model.
Revealing the Role of Cross Slip for Serrated Plastic Deformation in Concentrated Solid Solutions at Cryogenic Temperatures
Authors: Tirunilai Aditya Srinivasan , Weiss Klaus-Peter , Freudenberger Jens , Heilmaier Martin , Kauffmann Alexander
Published: March 2022

Serrated plastic deformation is an intense phenomenon in CoCrFeMnNi at and below 35 K with stress amplitudes in excess of 100 MPa. While previous publications have linked serrated deformation to dislocation pile ups at Lomer–Cottrell (LC) locks, there exist two alternate models on how the transition from continuous to serrated deformation occurs. One model correlates the transition to an exponential LC lock density–temperature variation. The second model attributes the transition to a decrease in cross-slip propensity based on temperature and dislocation density. In order to evaluate the validity of the models, a unique tensile deformation procedure with multiple temperature changes was carried out, analyzing stress amplitudes subsequent to temperature changes. The analysis provides evidence that the apparent density of LC locks does not massively change with temperature. Instead, the serrated plastic deformation is likely related to cross-slip propensity.
Effect of Corrugated Sheet Diameter on Structural Behavior under Cryogenic Temperature and Hydrodynamic Load
Authors: Park Jin-Seok , Kim Jeong-Hyeon , Jeong Yong-Cheol , Kim Hee-Tae , Kim Seul-Kee , Lee Jae-Myung
Published: March 2022

The most important technical issue in the shipbuilding industry regarding liquefied natural gas (LNG) carrier cargo containment systems (CCS) is securing the structural reliability of the primary barrier, which is in direct contact with the LNG. Fracture of the primary barrier by the hydrodynamic load of the LNG CCS may lead to disasters because it is difficult to implement immediate safety measures in the marine environment, unlike on land. Hence, structural reliability of the LNG membrane is the most critical issue in LNG carrier CCSs, where thin and corrugated 304L stainless steel is often used as the primary barrier to prevent repeated thermal deformation from the temperature difference during loading (−163 °C) and unloading (20 °C) of the LNG. However, plastic deformation of the 1.2 mm-thick corrugated membrane of the LNG CCS has been reported continuously owing to its vulnerability to cryogenic hydrodynamic loads. In the present study, we conducted a parametric analysis to investigate the effects of the corrugation shape as a preliminary study of the primary barrier. Finite element analysis was conducted with a simplified plate to focus on the effects of corrugation. Furthermore, a two-step validation was conducted using the above experimental results to ensure reliability of the structural analysis. The results show that optimizing the corrugation shape could ensure better structural safety than the conventional design.
A Longitudinal 1H NMR-Based Metabolic Profile Analysis of Urine from Hospitalized Premature Newborns Receiving Enteral and Parenteral Nutrition
Authors: Esturau-Escofet Nuria , Rodríguez de San Miguel Eduardo , Vela-Amieva Marcela , García-Aguilera Martha E. , Hernández-Espino Circe C. , Macias-Kauffer Luis , López-Candiani Carlos , Naveja José J. , Ibarra-González Isabel
Published: March 2022

Preterm newborns are extremely vulnerable to morbidities, complications, and death. Preterm birth is a global public health problem due to its socioeconomic burden. Nurturing preterm newborns is a critical medical issue because they have limited nutrient stores and it is difficult to establish enteral feeding, which leads to inadequate growth frequently associated with poor neurodevelopmental outcomes. Parenteral nutrition (PN) provides nutrients to preterm newborns, but its biochemical effects are not completely known. To study the effect of PN treatment on preterm newborns, an untargeted metabolomic 1H nuclear magnetic resonance (NMR) assay was performed on 107 urine samples from 34 hospitalized patients. Multivariate data (Principal Component Analysis, PCA, Orthogonal partial least squares discriminant analysis OPLS-DA, parallel factor analysis PARAFAC-2) and univariate analyses were used to identify the association of specific spectral data with different nutritional types (NTs) and gestational ages. Our results revealed changes in the metabolic profile related to the NT, with the tricarboxylic acid cycle and galactose metabolic pathways being the most impacted pathways. Low citrate and succinate levels, despite higher glucose relative urinary concentrations, seem to constitute the metabolic profile found in the studied critically ill preterm newborns who received PN, indicating an energetic dysfunction that must be taken into account for better nutritional management.
Belt Tear Detection for Coal Mining Conveyors
Authors: Guo Xiaoqiang , Liu Xinhua , Zhou Hao , Stanislawski Rafal , Królczyk Grzegorz , Li Zhixiong
Published: March 2022

The belt conveyor is the most commonly used conveying equipment in the coal mining industry. As the core part of the conveyor, the belt is vulnerable to various failures, such as scratches, cracks, wear and tear. Inspection and defect detection is essential for conveyor belts, both in academic research and industrial applications. In this paper, we discuss existing techniques used in industrial production and state-of-the-art theories for conveyor belt tear detection. First, the basic structure of conveyor belts is discussed and an overview of tear defect detection methods for conveyor belts is studied. Next, the causes of conveyor belt tear are classified, such as belt aging, scratches by sharp objects, abnormal load or a combination of the above reasons. Then, recent mainstream techniques and theories for conveyor belt tear detection are reviewed, and their characteristics, advantages and shortcomings are discussed. Furthermore, image dataset preparation and data imbalance problems are studied for belt defect detection. Moreover, the current challenges and opportunities for conveyor belt defect detection are discussed. Lastly, a case study was carried out to compare the detection performance of popular techniques using industrial image datasets. This paper provides professional guidelines and promising research directions for researchers and engineers based on the leading theories in machine vision and deep learning.
Miniaturized Sulfite-Based Gold Bath for Controlled Electroplating of Zone Plate Nanostructures
Authors: Ohlin Hanna , Frisk Thomas , Åstrand Mattias , Vogt Ulrich
Published: March 2022

X-ray zone plates made from gold are common optical components used in X-ray imaging experiments. These nanostructures are normally fabricated using a combination of electron-beam lithography and gold electroplating with cyanide gold baths. In this study, we present a gold electroplating process in a miniaturized gold-suplphite bath. The miniaturization is enabled by on-chip reference plating areas with well defined sizes, offering a reliable way to control the height of the structures by carefully choosing the plating time at a given current density in accordance with a calibration curve. Fabricated gold zone plates were successfully used in X-ray imaging experiments with synchrotron radiation. Although gold electroplating of nanostructures is a well-established method, details about the actual process are often missing in the literature. Therefore, we think that our detailed descriptions and explanations will be helpful for other researchers that would like to fabricate similar structures.
Dispersion Engineering of Silicon Nitride Microresonators via Reconstructable SU-8 Polymer Cladding
Authors: Wang Shang-Pu , Lee Tien-Hsiang , Chen You-Yuan , Wang Pei-Hsun
Published: March 2022

In this work, we propose a novel way to flexibly engineer the waveguide dispersion by patterning the cladding of waveguide microresonators. Experimentally, we demonstrate silicon nitride waveguides with air-, oxide-, and SU-8 polymer-cladding layers and compare the corresponding waveguide dispersion. By integrating SU-8 polymer as the outer cladding layer, the waveguide dispersion can be tuned from −143 to −257 ps/nm/km. Through the simple, conventional polymer stripping process, we reconstruct the waveguide dispersion back to that of the original air-cladded device without significantly impacting the quality factor of resonators. This work provides the potential to design the waveguide dispersion in normal and anomalous regimes within an integrated photonic circuit.
Optical Force and Torque on a Graphene-Coated Gold Nanosphere by a Vector Bessel Beam
Authors: Yan Bing , Ling Xiulan , Li Renxian , Zhang Jianyong , Liu Chenhua
Published: March 2022

In the framework of the generalized Lorenz–Mie theory (GLMT), the optical force and torque on a graphene-coated gold nanosphere by a vector Bessel beam are investigated. The core of the particle is gold, whose dielectric function is given by the Drude–Sommerfeld model, and the coating is multilayer graphene with layer number N, whose dielectric function is described by the Lorentz–Drude model. The axial optical force Fz and torque Tz are numerically analyzed, and the effects of the layer number N, wavelength λ, and beam parameters (half-cone angle α0, polarization, and order l) are mainly discussed. Numerical results show that the optical force and torque peaks can be adjusted by increasing the thickness of the graphene coating, and can not be adjusted by changing α0 and l. However, α0 and l can change the magnitude of the optical force and torque. The numerical results have potential applications involving the trapped graphene-coated gold nanosphere.
Temperature-Dependent Optical Properties of Perovskite Quantum Dots with Mixed-A-Cations
Authors: Hu Lei , Zhao Weiren , Duan Weijia , Chen Guojie , Fan Bingfeng , Zhang Xiaoli
Published: March 2022

In this work, metal halide perovskite quantum dots (QDs) with Formamidinium (FA) and Cs mixed cations were fabricated using a solution-processed method at room temperature. By controlling Cs doping ratios in a precursor, the optical properties of mixed-cation perovskite QDs were systematically studied. With the increase in Cs ion doping, the photoluminescence (PL) spectra of perovskite QDs were blueshifted, which was mainly due to the smaller radius of Cs ions than those of FA. Temperature-dependent PL spectra were conducted on mixed-cation perovskite QDs. As the temperature gradually increased from 4 K to 300 K, PL peaks were blue shifted, and full-width at half maximum (FWHM) was widened, which was directly related to lattice thermal expansion and the carrier-photon coupling effect under temperature variation. At the same time, excess Cs ion doping had a prominent influence on optical properties at low temperatures, which was mainly due to the introduction of detrimental defects in perovskite crystals. Therefore, it is particularly important to control doping concentration in the preparation of high-quality perovskite QDs and efficient photoelectric devices.
Design of a Capacitive MEMS Accelerometer with Softened Beams
Authors: Wang Chenggang , Hao Yongcun , Sun Zheng , Zu Luhan , Yuan Weizheng , Chang Honglong
Published: March 2022

Lower stiffness can improve the performance of capacitive-based microelectromechanical systems sensors. In this paper, softened beams, achieved by the electrostatic assembly approach, are proposed to lower the stiffness of a capacitive MEMS accelerometer. The experiments show that the stiffness of the accelerometer is reduced by 43% with softened beams and the sensitivity is increased by 72.6%. As a result, the noise of the accelerometer is reduced to 26.2 μg/√Hz with an improvement of 44.5%, and bias instability is reduced to 5.05 μg with an enhancement of 38.7%. The electrostatic assembly-based stiffness softening technique is proven to be effective and can be used in many types of MEMS devices.
Printed Circuit Boards: The Layers’ Functions for Electronic and Biomedical Engineering
Authors: Perdigones Francisco , Quero José
Published: March 2022

This paper describes the fabrication opportunities that Printed Circuit Boards (PCBs) offer for electronic and biomedical engineering. Historically, PCB substrates have been used to support the components of the electronic devices, linking them using copper lines, and providing input and output pads to connect the rest of the system. In addition, this kind of substrate is an emerging material for biomedical engineering thanks to its many interesting characteristics, such as its commercial availability at a low cost with very good tolerance and versatility, due to its multilayer characteristics; that is, the possibility of using several metals and substrate layers. The alternative uses of copper, gold, Flame Retardant 4 (FR4) and silver layers, together with the use of vias, solder masks and a rigid and flexible substrate, are noted. Among other uses, these characteristics have been using to develop many sensors, biosensors and actuators, and PCB-based lab-on chips; for example, deoxyribonucleic acid (DNA) amplification devices for Polymerase Chain Reaction (PCR). In addition, several applications of these devices are going to be noted in this paper, and two tables summarizing the layers’ functions are included in the discussion: the first one for metallic layers, and the second one for the vias, solder mask, flexible and rigid substrate functions.
Monitoring Junction Temperature of RF MOSFET under Its Working Condition Using Fiber Bragg Grating
Authors: Liu Zhenmin , Chen Na , Liu Yong , Chen Zhenyi , Pang Fufei , Wang Tingyun
Published: March 2022

When a high-power radio frequency (RF) metal oxide semiconductor field effect transistor (MOSFET) works in low-efficiency situations, considerable power is dissipated into heat, resulting in an excessive junction temperature and a likely failure. In this study, an optical fiber Bragg grating (FBG) sensor is installed on the die of a high-power RF MOSFET. The temperature change of RF MOSFET with the change of input signal is obtained by using the temperature frequency shift characteristic of the FBG reflected signal. Furthermore, the fast and repetitive capture of junction temperature by FBG reveals details of the temperature variation within each RF pulse, which is correctly correlated with input signals. The results show that besides monitoring the temperature accumulation of the chip for a long time, the FBG can also capture junction temperature details of the chip within each pulse period. Finally, a Cauer-type thermal model of the RF MOSFET was constructed based on the temperature information captured by the FBG.
A Novel AlGaN/Si3N4 Compound Buffer Layer HEMT with Improved Breakdown Performances
Authors: Guo Jingwei , Hu Shengdong , Li Ping , Jiang Jie , Wang Ruoyu , Wang Yuan , Wu Hao
Published: March 2022

In this article, an AlGaN and Si3N4 compound buffer layer high electron mobility transistor (HEMT) is proposed and analyzed through TCAD simulations. In the proposed HEMT, the Si3N4 insulating layer is partially buried between the AlGaN buffer layer and AlN nucleating layer, which introduces a high electric field from the vertical field plate into the internal buffer region of the device. The compound buffer layer can significantly increase the breakdown performance without sacrificing any dynamic characteristics and increasing the difficulty in the fabrication process. The significant structural parameters are optimized and analyzed. The simulation results reveal that the proposed HEMT with a 6 μm gate-drain distance shows an OFF-state breakdown voltage (BV) of 881 V and a specific ON-state resistance (Ron,sp) of 3.27 mΩ·cm2. When compared with the conventional field plate HEMT and drain connected field plate HEMT, the breakdown voltage could be increased by 148% and 94%, respectively.
Complementary Approaches for Enhancing Polystyrene Hydrophobicity: Additives Development and Replication of Micro/Nanotextures
Authors: Le Brouster Rachel , Giboz Julien , Nourdine Ali , Tenchine Lionel , Dubelley Florence , Mele Patrice
Published: March 2022

This work aims at developing polymer surfaces with enhanced hydrophobicity by controlling both the surface chemistry and the surface structure. As a first step, a chemical surface modification is achieved by the incorporation of a synthetized tailored fluorinated copolymer, named POISE-a (Polymer prOcessing Interface StabilizEr), in a commercial polystyrene matrix. Then, a complementary physical approach based on micro-structuration of a polymer surface is used. Polystyrene films containing various contents of POISE-a were elaborated by a solvent casting method. The structuration of the films was conducted by replicating a texture from a nickel insert using a hot-embossing technique with optimized processing conditions. The beneficial effect of POISE-a on both the wettability properties and the replication efficiency was evaluated by the water/polymer static contact angle and the quantification of the replication rate, respectively. The use of this tailored additive, even at low percentages (i.e., 1 wt.%), associated with the structuration of the PS surface, improves both the hydrophobicity of polystyrene and the robustness of the replication process.
Fabrication of 3D GelMA Scaffolds Using Agarose Microgel Embedded Printing
Authors: Yang Bo , Liu Tianqi , Gao Ge , Zhang Xianglin , Wu Bin
Published: March 2022

Photocrosslinked Gelatin–Methacryloyl (GelMA) has been widely used in the field of 3D bioprinting due to its excellent biological properties, but its properties are not yet optimized. With the advent of embedded printing, the balance between hydrogel printability and cell viability is expected to be achieved. Agarose microgel is a good support material because of its simple preparation, good biocompatibility, high melting point, and good rheology. In this study, aiming at realizing a GelMA/Agarose suspension printing system, the printing effect of the suspension process was explored, and a suitable process printing window was defined. The resulting scaffolds showed better water absorption and elasticity, but larger deformation during printing. This study explored some potential roles of suspension baths in embedded printing, paving the way for the preparation of good suspension structures that can be convenient for customized tissue engineering applications.
On-Chip Optical Beam Manipulation with an Electrically Tunable Lithium-Niobate-on-Insulator Metasurface
Authors: Dou Linyuan , Xie Lingyun , Wei Zeyong , Wang Zhanshan , Cheng Xinbin
Published: March 2022

Photonic integrated circuits (PICs) have garnered increasing attention because of their high efficiency in information processing. Recently, lithium niobate on insulator (LNOI) has become a new platform for PICs with excellent properties. Several tunable devices such as on-chip tunable devices that utilize the electric-optic effect of LN have been reported. However, an on-chip electrically tunable beam modulator that can focus or deflect the wave has not yet been developed. In this study, we designed an electrically tunable LNOI metasurface for on-chip optical beam manipulation. With a carefully designed local phase profile, we realized the tunable focusing and reflection functions on the chip. As the bias voltage varies, the focusing length can be shifted up to 19.9 μm (~13λ), whereas the focusing efficiency remains greater than 72%. A continuously tunable deflection can also be achieved efficiently within a range of 0–45°. The beam modulator enhances the ability to manipulate light on LNOI chips, which is expected to promote the development of integrated on-chip photonics.
Editorial for the Topic on Micromachining for Advanced Biological Imaging
Authors: Yoo Young Jin , Song Young Min
Published: March 2022

Biological imaging has opened novel paths for discoveries and advances in biology ranging from molecular to tissue scales [...]
Detecting the Knowledge Domains of Compound Semiconductors
Authors: Lee Qian-Yo , Chou Chiyang James , Lee Ming-Xuan , Lee Yen-Chun
Published: March 2022

The development of compound semiconductors (CS) has received extensive attention worldwide. This study aimed to detect and visualize CS knowledge domains for quantifying CS research patterns and emerging trends through a scientometric review based on the literature between 2011 and 2020 by using CiteSpace. The combined dataset of 24,622 bibliographic records were collected through topic searches and citation expansion to ensure adequate coverage of the field. While research in “solar cell” and “perovskite tandem” appears to be the two most distinctive knowledge domains in the CS field, research related to thermoelectric materials has grown at a respectable pace. Most notably, the deep connections between “thermoelectric material” and “III-Sb nanowire (NW)” research have been demonstrated. A rapid adaptation of black phosphorus (BP) field-effect transistors (FETs) and gallium nitride (GaN) transistors in the CS field is also apparent. Innovative strategies have focused on the opto-electronics with engineered functionalities, the design, synthesis and fabrication of perovskite tandem solar cells, the growing techniques of Sb-based III–V NWs, and the thermal conductivity of boron arsenide (BAs). This study revealed how the development trends and research areas in the CS field advance over time, which greatly help us to realize its knowledge domains.
Development of a Soft Robotics Module for Active Control of Sitting Comfort
Authors: Roozendaal Tjark , Verwaal Martin , Buso Alice , Scharff Rob B. N. , Song Yu , Vink Peter
Published: March 2022

Sitting comfort is an important factor for passengers in selecting cars, airlines, etc. This paper proposes a soft robotic module that can be integrated into the seat cushion to provide better comfort experiences to passengers. Building on rapid manufacturing technologies and a data-driven approach, the module can be controlled to sense the applied force and the displacement of the top surface and actuate according to four designed modes. A total of 2 modules were prototyped and integrated into a seat cushion, and 16 subjects were invited to test the module’s effectiveness. Experiments proved the principle by showing significant differences regarding (dis)comfort. It was concluded that the proposed soft robotics module could provide passengers with better comfort experiences by adjusting the pressure distribution of the seat as well as introducing a variation of postures relevant for prolonged sitting.
Continuous Glucose Monitoring System Based on Percutaneous Microneedle Array
Authors: Chien Ming-Nan , Chen Yu-Jen , Bai Chin-Han , Huang Jung-Tung
Published: March 2022

A continuous blood glucose monitoring system (CGMS) which include a microneedle-array blood glucose sensor, a circuit module, and a transmission module placed in a wearable device is developed in this research. When in use, the wearable device is attached to the human body with the microneedle array inserted under the skin for continuous blood glucose sensing, and the measured signals are transmitted wirelessly to a mobile phone or computer for analysis. The purpose of this study is to replace the conventionally used method of puncture for blood collection and test strips are used to measure the blood glucose signals. The microneedle sensor of this CGMS uses a 1 mm length needle in a 3 mm × 3 mm microneedle array for percutaneous minimally invasive blood glucose measurement. This size of microneedle does not cause bleeding damage to the body when used. The microneedle sensor is placed under the skin and their solutions are discussed. The blood glucose sensor measured the in vitro simulant fluid with a glucose concentration range of 50~400 mg/dL. In addition, a micro-transfer method is developed to accurately deposit the enzyme onto the tip of the microneedle, after which cyclic voltammetry (CV) is used to measure the glucose simulation solution to verify whether the difference in the amount of enzyme on each microneedle is less than 10%. Finally, various experiments and analyses are carried out to reduce the size of the device, test effective durability (approximately 7 days), and the feasibility of minimally invasive CGMS is evaluated by tests on two persons.
Editorial for the Special Issue on Particles Separation in Microfluidic Devices, Volume II
Authors: Tottori Naotomo , Nisisako Takasi
Published: March 2022

Particle separation in the nano- to microscale range is a significant step for biological, chemical, and medical analyses [...]
Recent Advances in Thermoplastic Microfluidic Bonding
Authors: Giri Kiran , Tsao Chia-Wen
Published: March 2022

Microfluidics is a multidisciplinary technology with applications in various fields, such as biomedical, energy, chemicals and environment. Thermoplastic is one of the most prominent materials for polymer microfluidics. Properties such as good mechanical rigidity, organic solvent resistivity, acid/base resistivity, and low water absorbance make thermoplastics suitable for various microfluidic applications. However, bonding of thermoplastics has always been challenging because of a wide range of bonding methods and requirements. This review paper summarizes the current bonding processes being practiced for the fabrication of thermoplastic microfluidic devices, and provides a comparison between the different bonding strategies to assist researchers in finding appropriate bonding methods for microfluidic device assembly.
Characterization of a Centrifugal Microfluidic Orthogonal Flow Platform
Authors: Woolf Michael , Dignan Leah , Karas Scott , Lewis Hannah , Hadley Kevyn , Nauman Aeren , Gates-Hollingsworth Marcellene , AuCoin David , Green Heather , Geise Geoffrey , Landers James
Published: March 2022

To bring to bear the power of centrifugal microfluidics on vertical flow immunoassays, control of flow orthogonally through nanoporous membranes is essential. The on-disc approach described here leverages the rapid print-cut-laminate (PCL) disc fabrication and prototyping method to create a permanent seal between disc materials and embedded nanoporous membranes. Rotational forces drive fluid flow, replacing capillary action, and complex pneumatic pumping systems. Adjacent microfluidic features form a flow path that directs fluid orthogonally (vertically) through these embedded membranes during assay execution. This method for membrane incorporation circumvents the need for solvents (e.g., acetone) to create the membrane-disc bond and sidesteps issues related to undesirable bypass flow. In other recently published work, we described an orthogonal flow (OF) platform that exploited embedded membranes for automation of enzyme-linked immunosorbent assays (ELISAs). Here, we more fully characterize flow patterns and cellulosic membrane behavior within the centrifugal orthogonal flow (cOF) format. Specifically, high-speed videography studies demonstrate that sample volume, membrane pore size, and ionic composition of the sample matrix significantly impact membrane behavior, and consequently fluid drainage profiles, especially when cellulosic membranes are used. Finally, prototype discs are used to demonstrate proof-of-principle for sandwich-type antigen capture and immunodetection within the cOF system.
Short-Term Exposure to Thermophilic Temperatures Facilitates CO Uptake by Thermophiles Maintained under Predominantly Mesophilic Conditions
Authors: Wilson Caitlin K. , King Gary M.
Published: March 2022

Three phylogenetically and phenotypically distinct CO-oxidizing thermophiles (Alicyclobacillus macrosporangiidus CPP55 (Firmicutes), Meiothermus ruber PS4 (Deinococcus-Thermus) and Thermogemmatispora carboxidovorans PM5T (Chloroflexi)) and one CO-oxidizing mesophile (Paraburkholderia paradisi WAT (Betaproteobacteria)) isolated from volcanic soils were used to assess growth responses and CO uptake rates during incubations with constant temperatures (25 °C and 55 °C) and during multi-day incubations with a temperature regime that cycled between 20 °C and 55 °C on a diurnal basis (alternating mesophilic and thermophilic temperatures, AMTT). The results were used to test a conjecture that some thermophiles can survive in mesothermal habitats that experience occasional thermophilic temperatures. Meiothermus ruber PS4, which does not form spores, was able to grow and oxidize CO under all conditions, while the spore-forming Alicyclobacillus macrosporangiidus CPP55 grew and oxidized CO during the AMTT regime and at 55 °C, but was not active at 25 °C. Thermogemmatispora carboxidovorans PM5T, also a spore former, only grew at 55 °C but oxidized CO during AMTT and 55 °C incubations. In contrast, the non-sporing mesophile, Paraburkholderia paradisi WAT, was only able to grow and oxidize CO at 25 °C; growth and CO uptake ceased during the AMTT incubations after exposure to the initial round of thermophilic temperatures. Collectively, these results suggest that temporary, periodic exposure to permissive growth temperatures could help maintain populations of thermophiles in mesothermal habitats after deposition from the atmosphere or other sources.
A Methodology to Assess the Historical Environmental Footprint of In-Situ Recovery (ISR) of Uranium: A Demonstration in the Goliad Sand in the Texas Coastal Plain, USA
Authors: Gallegos Tanya J. , Scott Anne M. , Stengel Victoria G. , Teeple Andrew P.
Published: March 2022

In-situ recovery (ISR) has been the only technique used to extract uranium from sandstone-hosted uranium deposits in the Pliocene Goliad Sand in the Texas Coastal Plain. Water plays a crucial role throughout the ISR lifecycle of production and groundwater restoration yet neither the water use nor other environmental footprints have been well documented. The goal of this study is to examine historical records for all six ISR operations completed in the Goliad Sand to identify and quantify parameters that indicate the surface and aquifer disturbances, water use, and radon emissions. Overall, the average mine area was 0.00023 ± 0.00006 acres per pound (ac/lb) U3O8. The average mine pore volume was 48.9 ± 50 gal/lb U3O8 with a minimum affected aquifer volume of 0.51 ± 0.08 cubic feet per pound (cu ft/lb) U3O8. An average of 258 ± 40 gallons (gal) of fluid were disposed per pound (lb) U3O8, with an average of 169 ± 26 gal/lb U3O8 attributed to restoration and 89 ± 36 gal/lb U3O8 attributed to the uranium production phase. The average radon emitted was 1.06 × 10−3 ± 7.4 × 10−4 curies per pound (Ci/lb) U3O8. Goodness-of-fit (R2) values are ≥0.79 for linear regressions of the amount of uranium produced versus mine area, mine pore volumes, mine aquifer volumes, water pumped, and total water disposed. The R2 value for radon emitted was 0.68. However, the water disposed only during the uranium production phase is more strongly correlated to the number of production days (R2 = 0.96) than to uranium production (R2 = 0.84), whereas the volume of water disposed during restoration is more strongly correlated to the “pore volume” (R2 = 0.97) than to uranium production (R2 = 0.90). Pore volume is an industry term used to describe the amount of fluid circulated through the aquifer during the uranium production period and stipulated in bond agreements in order to satisfy groundwater restoration requirements. Models constructed in this study can be used to estimate probable water use and the extent of surface and aquifer disturbances associated with ISR-amenable undiscovered uranium resources in the Goliad Sand. The historical perspective offered by the data compiled and correlations may prove useful to both industry and regulators.
Insights into the Metallogenesis of the Felsic Volcanic Hosted Mundiyawas-Khera Cu Deposit, Alwar Basin, Western India
Authors: Sahoo Janmejaya , Sahoo Prabodha Ranjan , Khan Israil , Venkatesh Akella Satya
Published: March 2022

Copper and associated gold mineralization in the Mundiyawas-Khera area of western India is hosted by the Proterozoic felsic volcanic rocks of rhyo-dacite composition. Signatures of hydrothermal alteration represented by sericite, epidote, scapolite and carbonates are well observed around the ore mineralization zone. The felsic volcanic rocks with gently to flat sloping REE pattern, variable negative Eu anomaly, intermediate abundances of HFSE and moderate to low Zr/Y anomalies are suggested to be FII, FIIIa and FIV type rhyolite. The felsic volcanic host rock for copper mineralization has a depleted and flat HREE pattern and indicates the crustal source, which is garnet free. Negative Eu anomaly in the rock is probably because of the intracrustal partial melting formed in a rift related environment. The high temperature magmatic activities are probably evolved due to the partial melting of crust at shallow to moderate depths, suggesting an evolved continental crust. The δ13C values of the mineralized carbonate veins range between −10.4‰ and −0.9 ‰ (min = −10.6‰, n = 27), whereas the δ18O values show a range of 16.35‰ to 25.23‰ (min = 21.49‰, n = 27), ideally suggesting a mixed source for the ore bearing fluid. Geological, geochemical and stable isotope data of the Mundiyawas-Khera copper deposit suggest it to be a VMS/VHMS setup and these insights will lead to finding new deposits in the nearby areas, having same stratigraphic horizons and similar lithogeochemical assemblages.
Responses of Pre-Holed Granite under Coupled Biaxial Loading and Unloading Stress Condition
Authors: Zhou Zilong , Pi Zizi , Jing Yue , Wang Shaofeng
Published: March 2022

Underground excavation is a necessary process for constructing mines, tunnels and depots in granite rock mass. In this study, the numerical granite specimens were established by the discrete element method and confirmed by laboratory experiments in order to investigate the peak stress, cracking development and failure properties of pre-holed granite under coupled biaxial loading and unloading conditions. The results show that, for the specimens containing D-type and square holes, the peak biaxial unloading strengths first decrease, then increase and finally decrease as the inclination angles of the holes increase. For the specimens with elliptical holes, the peak biaxial unloading strengths first decrease and then increase with the increases in the inclination angles of the holes. The biaxial unloading strengths of specimens containing elliptical, circular, D-type and square holes decrease in that order. The cracks initially appear near the crossover points between the X-type shear fracturing plane and the pre-hole in the center and gradually expand along the X-type shear direction, which indicates that the failure of pre-holed granite is primarily shear failure. When the overall length of cracks expanding along the X-type shear direction extends to the size of the pre-hole in the center, the failure of the pre-holed specimen occurs. When the existing pre-hole in the center of the granite specimen extends to connect with the shear slip in the vicinity of the hole, this triggers overall failure.
A Combined EMPA and LA-ICP-MS Study of Muscovite from Pegmatites in the Chinese Altai, NW China: Implications for Tracing Rare-Element Mineralization Type and Ore-Forming Process
Authors: Zhou Qifeng , Qin Kezhang , Tang Dongmei , Wang Chunlong
Published: March 2022

The mineralogical studies of rare-element (REL) pegmatites are important for unraveling the ore-forming process and evaluating REL mineralization potential. The Chinese Altai orogenic belt hosting more than 100,000 pegmatite dykes is famous for rare-metal resources worldwide and diverse REL mineralization types. In this paper, we present the results of EMPA and LA-ICP-MS for muscovite from the typical REL pegmatite dykes of the Chinese Altai. The studied pegmatites are Li-Be-Nb-Ta, Li-Nb-Ta, Nb-Ta, Be-Nb-Ta, Be and barren pegmatites. The Li+ accompanied with Fe, Mg and Mn substitute for Al3+ at the octahedral site in muscovite from the REL pegmatites, and the substitution of Rb by Cs at the interlayer space is identified in muscovite from the Be pegmatites. The P and B contents increase with evolution degree and the lenses from the Nb-Ta pegmatite are produced at late fluid-rich stage with high fluxes (P and B). The enrichment of HFSE in muscovite indicates a Nb-Ta-Sn-W rich pegmatite magma for the Be-Nb-Ta pegmatite. From barren pegmatite, beryl-bearing zone, to spodumene-bearing zone, the evolution degrees of pegmatite-forming magmas progressively increase. In the Chinese Altai, the possible indicators of muscovite for REL mineralization types include Rb (ca. 400–600 ppm, barren pegmatite; ca. 1200–4000 ppm, Be pegmatite; >4500 ppm, Li pegmatite), Cs (ca. 5–50 ppm, barren pegmatite; ca. 100–500 ppm, Be pegmatite; >300 ppm, Li pegmatite) and Ge (<3 ppm, barren pegmatite; ca. 4–6 ppm, Be pegmatite; ca. 6–12 ppm, Li pegmatite) coupled with Ta, Be (both <10 ppm, barren pegmatite) and FeO (ca. 3–4 wt%, Be pegmatite; ca. 1–2.5 wt%, Li pegmatite). The plots of Nb/Ta vs. Cs and K/Rb vs. Ge are proposed to discriminate barren, Be- and Nb-Ta-(Li-Be-Rb-Cs) pegmatites. The Li, Be, Rb, Cs and F concentrations of forming liquid are evaluated based on the trace element compositions of muscovite. The high Rb and Cs contents of liquid and lower Be contents than beryl saturation value indicate that both highly evolved pegmatite magma and low temperature at emplacement contribute to beryl formation. The liquids saturated with spodumene have large variations of Li, possibly related to metastable state at Li unsaturation–supersaturation or heterogeneous distribution of lithium in the system.