bluuebunny/crossref_metadata_2025 huggingface dataset:
An Alternative Composite Polymer Electrolyte for High Performances Lithium Battery
Authors: Marangon Vittorio , Tominaga Yoichi , Hassoun Jusef
Published: July 2021

A composite electrolyte consisting of polyethylene-glycol dimethyl-ether (MW 2000 g mol-1), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) conducting salt, lithium nitrate (LiNO3) film-forming additive, and nanometric silica (SiO2) filler, is herein obtained by a scalable solvent casting pathway and thoroughly investigated for application in lithium metal polymer battery. Structure and morphology of the electrolyte are investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively, while its electrochemical features are revealed by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), chronoamperometry, and galvanostatic cycling tests in lithium cell. The room-temperature structure of the composite electrolyte reflects the combination into a complex of the membrane components, while its morphology appears smooth with uniform distribution of salts and ceramic. The electrolyte shows an ionic conductivity over 10-4 S cm-1 above 40 °C promoted by repeated heating and cooling, lithium transference number ranging from 0.22 at 45 °C to 0.27 at 70 °C, low interphase resistance and polarization in lithium cell, and an electrochemical stability window extending above 4.4 V. These optimal features allow the membrane to operate in a lithium cell with LiFePO4 cathode at 50 °C, with specific capacity exceeding 150 mAh g-1 and coulombic efficiency approaching 100% over prolonged cycling.

Figure 1
Selective Cobalt Precipitation for the Synthesis of Precursors for Cathode Materials of Li-Ion Batteries
Authors: Lavergne-Bril Anna-Caroline , Peralta David , Maldivi Pascale , Colin Jean-Francois , Celle Caroline , Patoux Sebastien
Published: July 2021

Due to the increase in energy storage for consumer electronics, stationary application and above all for electrical vehicles, the manufacturing of Li-ion batteries has dramatically increased in the past few years. Unfortunately, cathode materials still often use cobalt, and consequently, an increase of 10% per year of the world’s cobalt consumption has been observed. Li-ion batteries represent 60% of the use of extracted cobalt today (more than 80% expected in 2030), which is classified as a critical material since 2011 by the European Commission. Battery grade cobalt is produced by only few countries. 60% is provided by the Democratic Republic of Congo. In order to avoid reliance on cobalt supplying, European industry should have to develop alternative solution.

We present here a new way to extract cobalt from a solution of battery-waste materials. Through a one-step process, it is possible to recover the cobalt, selectively, in a solution composed in majority of cobalt, nickel and manganese.

The goal of the process is to form a cobalt-based Metal Organic Framework compounds (MOF) from a multi-metals based solution. The contact of a well-designed ligand with model multi-metallic solution of nickel, manganese and cobalt, under specific conditions, creates a precipitate, which is recovered by centrifugation or filtration. The XRD analysis of the resulting material demonstrates a crystalline structure, and its ICP analysis shows up to 99% of cobalt composition of the metallic nodes of the material. The same process with a real battery waste solution enables the formation of a precipitate made of 94% of cobalt (among the metallic centers).

The resulting MOF can be used as a precursor for synthetizing cathode materials. In order to complete the described closed-loop concept, it is indeed possible to assemble a coin-cell from those products. The well define crystalline structure of the MOF makes them suitable for other industrial application, such as separation or catalysis (open-loop concept).

We are focusing on better understanding of this selectivity process. Density Functional Theory (DFT) calculations are performed, as a tool to evaluate the energy of the different complexes in solution at all states of the nucleation and growth of the MOF. Moreover, the ligand used can form a MOF with each of the metals present in solution. Some nickel and manganese phases (more or less soluble) are involved during the process as a function of the reaction conditions. Identifying their nature and formation is another axis for the understanding of the presented work. Modelling these phenomena could help to determine the reaction that occurs, how the selectivity happens, and why the growing material is made of cobalt only (no other metal).
Temperature and Stability Study of All Oxynitride-Based Asymmetric Supercapacitor
Authors: Kumar U. Naveen , Ghosh Sourav , Jeevandoss C.R. , Gangavarapu Ranga Rao , Thomas Tiju
Published: July 2021

Supercapacitors (SCs) or electrochemical capacitors are of substantial utility due to their high-power density, moderate energy density, fast charge-discharge rates, long cycle life (~105 cycles), and environmental friendliness. In the past decade, due to the demands of the electrochemical energy storage sector, there has been a quest for novel supercapacitor electrode materials that offer champion storage characteristics. Recently, transition metal oxynitrides (TMONs) have gained much attention as electrode materials for supercapacitor (SC) applications due to their unique properties such as high electronic conductivity,wettability, corrosion resistance, and chemical robustness. Nanostructuring strategies of TMONs open up fresh avenues for energy storage. Various transition metal oxides (TMO) and metal nitrides (TMN) have been explored as electrode materials for SC applications. TMOs and TMNs are prone to poor cyclability and rate capabilities. Hence, there is a value of exploring intermediate transition oxynitride compounds (TMONs) in place of pure TMOs and TMNs.

In this work, a simple and scalable soft urea method is used to synthesize chromium oxynitride (CrOxNy) and cerium oxynitride (CeOxNy) nanoparticles in the place of the conventional ammonothermal method. These nanoparticles are used to fabricate asymmetric coin cell devices, where CeOxNy is used as a positive electrode and CrOxNy is used as negative electrode material. The fabricated asymmetric device is subjected to electrochemical characterization techniques such as cyclic voltammetry, galvanostatic charge-discharge (GCD), leakage current analysis, and electrochemical impedance spectroscopy (EIS). From GCD measurement, It reveals that the device exhibits an areal capacitance of 21.48 mF cm-2 at 0.3 mA cm-2, cycled up to 105 cycles at room temperature (25 oC). Further, an asymmetric device is tested at different temperatures (-5 oC, 0 oC, 25 oC, and 50 oC) using an environmental climate chamber to validate the real-time application. The areal capacitance of the device at different temperature is compared and it shows that 11.28 mF cm-2, 12.67 mF cm-2 , 21.48 mF cm-2 , and 8.96 mF cm-2 at -5 oC, 0 oC, 25 oC, and 50 oC respectively. The device retains 41.8% of its areal capacitance even at high temperature (50 oC) when compared with room temperature (25 oC). The temperature-based study provides the promising nature of the fabricated device, and the performance has attributed to the stability of both oxynitride electrode material even at extremely low (-5 oC) and high temperature (50 oC).

Figure 1
Probing Sources of Capacity Fade in NMC622: An Operando xrd Study of NMC Batteries over Cycling
Authors: Quilty Calvin , Bock David C , Yan Shan , Takeuchi Kenneth J. , Takeuchi Esther S. , Marschilok Amy C.
Published: July 2021

LiNi0.6Mn0.2Co0.2O2 (NMC622) is a highly promising Li-ion battery cathode due to its high energy density and excellent reversibility. However high potential charging which can lead to much greater energy density comes at the cost of compromised reversibility. It has been suggested that this loss of reversibility is a result of particle disintegration caused by the anisotropic lattice changes and elevated microstrain at high potentials. Operando X-ray diffraction was utilized to probe the influence of these factors on capacity fade in Li/NMC622 cells both before and after 100 cycles at 3-4.3 or 4.7 V. In addition, scanning electron microscopy (SEM) was performed to observe potential particle disintegration. This study allowed for the collection of structural information about the battery system in real time over the time frame in which capacity fade was observed. Initially, charging to 4.7 V led to increased lattice distortions when compared to 4.3 V; however, after cycling, the lattice distortions were identical independent of charging potential but charging to 4.7 V led to a substantial buildup of microstrain. Additionally, SEM showed that significant damage was done to the particle morphology at 4.7 V, while there were minimal changes at 4.3 V; showing that high potential elevated microstrain is likely a major factor in particle disintegration and capacity fade in this system. This study demonstrates important findings on the mechanisms of capacity fade in NMC622 batteries, which is crucial for the design of next generation NMC battery systems that can maximize both energy density and reversibility.
Full Utilization of Lithium Trivandate (Li1.1V3O8) in Thick Porous Electrodes with High Rate Capacity upon Extended Cycling Elucidated Via Operando Energy Dispersive X-Ray Diffraction
Authors: McCarthy Alison H. , Mayilvahanan Karthik , Dunkin Mikaela R. , King Steven T. , Quilty Calvin , Housel Lisa M. , Kuang Jason , Takeuchi Kenneth J. , Takeuchi Esther S. , West Alan C. , Wang Lei , Marschilok Amy C.
Published: July 2021

Newer, more demanding energy storage systems require high energy density along with high power and fast charge rates. Conventional battery electrode fabrication techniques are often limited by how much active material they can hold in the case of slurry-cast electrodes and how much of the electrode can be utilized in the case of dense pelletized electrodes. Thick porous electrode fabrication techniques have been developed as a way to obtain a higher active mass loading and an architecture which enables ionic and electronic transport. The homogeneity of the phase distribution of lithiated LVO in thick (∼500 μm) porous electrodes (TPEs) designed to facilitate both ion and electron transport was determined using synchrotron-based operando energy dispersive X-ray diffraction (EDXRD). Probing 3 positions in the TPE while cycling at a fast rate of 1C revealed a homogeneous phase transition across the thickness of the electrode at the 1st and 95th cycles. Continuum modelling indicated homogenous lithiation across the electrode upon discharge at 1C consistent with the EDXRD results and ascribed decreasing accessible active material to be the cause of loss in delivered capacity between the 1st and 95th cycles. The model was supported by the observation of significant particle fracture by SEM consistent with loss of electrical contact. The absence of the beta phase peaks in the EDXRD over extended cycling are consistent with electrochemical accessibility of only part of the active material. Overall, the combination of operando EDXRD, continuum modeling, and ex situ measurements enabled a deeper understanding of lithium vanadium oxide transport properties under high rate extended cycling within a thick highly porous electrode architecture.
Single-Layer Graphene Coated-Metal Nanoparticles for Water Splitting
Authors: Shin Choel-Hwan , Park Gisang , Zhang Chunfei , Yu Jong-Sung
Published: July 2021

Graphene-coated metal nanoparticles (NPs) have attracted great attention owing to their unique structural, photochemical and electrochemical properties based on electron communication between graphene and metal NPs. The development of highly efficient and non-precious metal-based electrocatalysts for water splitting comprising hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is still a big challenge. The hybridization of nitrogen (N)-doped carbon and cost-effective transition metals is a promising approach to produce highly active catalysts for HER and OER. Herein, a highly controllable chemical vapor deposition method is designed for large-scale synthesis of nickel nanoparticle wrapped by single-layer N-doped graphene (Ni@SNG), where silica work as molecule sieve to tactfully assist single-layer graphene growth by depressing diffusion of carbon radicals. The Ni@SNG sample synthesized at 800 oC shows excellent activity for HER in alkaline solution with a low overpotential of 100 mV at 10 mA cm-2, which is close to state-of-the-art Pt/C catalyst. Furthermore, the Ni@SNG catalyst supported on nickel foil is developed as a magnetic adsorption binder-free electrode, which exhibits much improved performance on catalytic activity and stability than common Nafion binder-based electrode. Therefore, magnetism adsorption technique, taking full advantages of magnetic catalysts, will be a greatly promising approach to overcome high electron resistance and poor adhesive stability of polymer binder-based electrodes in actual applications.
Up- and Down-Converting Photons in Molecular Carbon Materials
Authors: Guldi Dirk
Published: July 2021

The Shockley-Queisser limit places an upper bound on solar conversion efficiency for a single p-n junction solar cell at slightly more than 30%. To surpass this limit, multi-exciton generation is being explored in inorganic semiconductors, while singlet fission (SF) is being investigated in arrays of conjugated organic molecules. In an optimal SF process, the lowest singlet excited state of one molecule (S1) that is positioned next to a second molecule in its ground state (S0) is down-converted into two triplet excited states (T1) each residing on one of the two adjacent molecules. The two triplet states initially form a correlated pair state 1(T1T1), which then evolves into two separated triplet states (T1 + T1). As such, the energetic requirement for SF is E(S1) ≥ 2 ´ E(T1).

We have set our focus in recent years on intramolecular SF in molecular carbon materials and their studies in solution rather than on intermolecular SF investigations in crystalline films.

Implicit in intramolecular SF is a resonant, direct excitation of the SF material. In dimers of molecular carbon materials linked by a myriad of molecular spacers, SF takes place with quantum yields of up to 200%. In addition, all key intermediates in the SF process, including the formation and decay of a quintet state that precedes formation of the pentacene triplet excitons, have been identified. This approach is, however, limited to the part of the solar spectrum, where, for example, the dimers of carbon materials feature a significant absorption cross-section. To employ the remaining part of the solar spectrum necessitates non-resonant, indirect excitation of the SF materials via either up- or down-conversion. For example, the up-conversion approach is realized with singlet excited states , which are accessed by two-photon absorptions (TPA). TPA is then followed in the second step of the sequence by an intramolecular SF – similar to what is seen upon resonant, direct excitation. Quite different is the down-conversion approach, which is based on an intramolecular Förster resonance energy transfer (FRET) and thereby the (photo)activation of the SF material. FRET requires the use of a complementary absorbing chromophore and enables funneling its excited state energy unidirectionally to the SF performing pentacene dimer. Again, SF completes the reaction sequence.
Simultaneously Improving Solution Processing and Electronic Doping in Carbon Nanotube Thermoelectrics
Authors: Campoy-Quiles Mariano
Published: July 2021

Thermoelectrics are solid state devices that convert waste heat into electricity. Their abundancy and low toxicity makes carbon materials good candidates for thermoelectric applications requiring large areas and operation at low to medium temperatures [1]. Carbon nanotubes (CNTs) offer generally good electrical conductivity, which is a must for thermoelectrics. While their Seebeck coefficient can also be high, it has been shown to decrease as the conductivity increases. Optimum performance, therefore, requires a fine tuned doping level in order to find the sweet spot. On the other side, CNTs are often difficult to process, which may limit its applicability for this type of applications.

In this invited talk, I will present two different strategies that our group is using in order to simultaneously improve processing capabilities and control doping level. First we will discuss the use of composites of CNTs and highly soluble polymers. Electron withdrawing or donating polymers, such as PEI and P3HT, respectively, help disperse the CNTs and simultaneously dope the CNT p- or n-type [2,3]. Alternatively, the use of bacteria to produce composites of cellulose and CNTs provides additional means of producing high performing composites [4]. Finally, I will describe our latest work on the use of alkali metals to form real CNT solutions and simultaneously produce stable n-doping of the resulting buckypapers [5].

[1] Will organic thermoelectrics get hot? M. Campoy-Quiles, Philosophical Transactions of the Royal Society A, 377, 20180352 (2019).

[2] Photoinduced p- to n-type Switching in Thermoelectric Polymer-Carbon Nanotube Composites, B. Dörling, J. D. Ryan, J. D. Craddock, A. Sorrentino, A. El Basaty, A. Gomez, M. Garriga, E. Pereiro, J. E. Anthony, M. C. Weisenberger, A. R. Goñi, C. Müller and M. Campoy-Quiles, Advanced Materials, 28, 2782 (2016).

[3] Investigating thermoelectric stability under encapsulation using PEI‐Doped CNT films as a model system, F. Abdallah, L. Ciammaruchi, A. Jiménez‐Arguijo, E.S.M. Duraia, H.S. Ragab, B. Dörling and M. Campoy‐Quiles, Advanced Materials Technologies, 5, 2000256 (2020).

[4] Farming thermoelectric paper, D. Abol-Fotouh, B. Dörling, O. Zapata-Arteaga, X. Rodríguez-Martínez, A. Gómez, J. S. Reparaz, A. Laromaine, A. Roig and M. Campoy-Quiles, Energy and Enviromental Science, 12, 716-726 (2019).

[5] Soluble Alkali-Metal CNT Salts for n-type Thermoelectric Composites, B. Dörling, X. Rodríguez-Martínez, I. Álvarez-Corzo, M. Campoy-Quiles, submitted (2021).
(Invited) Exploiting Counterion Chemistry for Enhanced Thermoelectric Carbon Nanotube Networks
Authors: Ferguson Andrew , Blackburn Jeff
Published: July 2021

Careful control of the charge-carrier density is required to optimize the thermoelectric performance of carbon nanotube networks. This control is typically provided through charge injection from chemical dopants that reside within the doped network. We will build upon previous demonstrations of effective p-type doping by employing a series of novel charge-transfer dopants based on dodecaborane clusters appended with various organic moieties that control both the structure and redox properties of the dopant. The unique chemical and electronic structure of these dopants, compared to oxidants like triethyloxonium hexachloroantimonate (OA) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), allow for the electron extracted from the carbon nanotube to be localized on the dodecaborane cluster. This results in spatial separation of the negative counter-charge on the center of the dodecaborane cluster from the hole density injected into the carbon nanotube, which improves charge-carrier transport within the network. This enhanced transport results in an increase in the thermoelectric power factor that surpasses the previous best-in-class for enriched semiconductor single-walled nanotube thin film networks.
(Invited) Carbon Nanostructures for Energy Storage Applications
Authors: Paranthaman Mariappan
Published: July 2021

The main goal of this research is to develop carbon nanostructures for next generation energy storage applications. The tailored morphology of the end-of-life tire rubber with a sulfonation process followed by pyrolysis yielded a high-quality nanostructured carbon and the applicability of these hard carbons was demonstrated in energy storage applications. We will report on our recent neutron studies on the surface chemistry of the carbon material, vibrational spectroscopy of the molecular structure, chemical bonding such as C-H bonding, and intermolecular interactions of the carbon materials. In addition, we will also report our recent success with tire-derived carbon with either tin oxide or antimony/antimony oxide based composites as a low-cost, environmentally benign, and high capacity anode material for energy storage applications.

ACKNOWLEDGEMENTSM

The research was sponsored by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division.
(Invited) Advances in Pyrolyzed Polymeric Sulfur Cathodes for Low-Cost Lithium Metal Batteries
Authors: Wang Shen , Liu Haodong , Wu Zhaohui , Holoubek John , Xing Xing , Liu Ping
Published: July 2021

Sulfur is a highly desirable cathode material for lithium batteries but its complex reaction mechanisms involving soluble species have limited its cycle life. When sulfur exists as a very short chain or substituted function groups on aromatic rings, the dissolution process appears to be mitigated, leading to a long cycle life. A good example is Sulfurized-poly(acrylonitrile) (SPAN), which is synthesized by pyrolyzing a mixture of PAN and elemental S at 300-500oC. SPAN is essentially a nitrogen doped carbon host for sulfur and has shown exceptional cycling stabilities in common carbonate electrolytes.

We have recently launched an intensive effort to advance the Li/SPAN battery technology to an energy density of > 300 Wh/kg. Its exceptional cycle life and low cost will make the technology a promising choice for electric vehicle applications. In this talk, we will review several interrelated efforts to realize this goal: 1) searching for SPAN-like materials with higher S loading and higher capacities by tuning N:C:S ratios with different polymer and sulfur precursors; 2) improving the packing density of SPAN particles in the cathode by controlling particle shape and size using new synthesis approaches. A highlight is a um-sized, platelet-like morphology that greatly increase packing densities; 3) developing a solvent-free homogenous chemical lithiation method for the synthesis of lithium containing SPAN. The lithiated SPAN can greatly reduce the irreversible capacity loss during the first discharge cycle and minimize the volume change associated with the initial lithiation process; and 4) continuing the development of new electrolyte compositions that can further improve the lithium metal anode efficiency without sacrificing SPAN cycle life. These studies hold the promise to enable a practical, low-cost and long-life Li/S battery.
Carbon Materials Derived from an Array of Zeolitic-Imidazolate Frameworks and Their Applications in Capacitive Deionization
Authors: Wang Hao , Liu Di-Jia
Published: July 2021

Capacitive deionization (CDI) represents one of the most thermodynamically efficient technologies for brackish water desalination, and its performance is highly dependent on the intrinsic properties of carbon materials. Ideally, CDI carbons should have high ion-accessible surface area, high porosity for ion mobility, great hydrophilic properties, excellent corrosion tolerance and good processability. Pyrolysis of precursory zeolitic-imidazolate frameworks (ZIFs) serves as a promising way to produce carbonaceous materials with great compositional and structural tunability.

In this work, we systematically prepared an array of ZIFs (Zn(ligand)2) with different side-chain substitutions, which upon pyrolysis gave rise to carbon materials with variable elemental compositions, surface properties, wettability and graphitization levels; all are impacting the CDI performance. Zn(4abIm)2-C afforded the best salt adsorption capacity, while Zn(mIm)2-C showed the best overall salt adsorption capacity and rate; both exceeded the performance of the commercial carbon blacks.

After careful correlation between the structures and the electrochemical results, it has been demonstrated that the CDI salt adsorption capacity increases with the carbon’s double layer capacitance. Additionally, graphitization level is significantly correlated with the CDI charge efficiency and energy consumption with more electronic conductive higher charge efficiency and lower energy consumption, which provides new insights to the field.
First Prototype 18650 Aqueous Supercapacitors Using Graphite Coated Al Foil As Low Cost and Anti-Corrosion Current Collector
Authors: Chomkhuntod Praeploy , Sawangphruk Montree
Published: July 2021

Supercapacitors have been attached much attention for power supplies due to their high-power density and excellent cycling stability. Up to now, the study of aqueous supercapacitors is increasing continuously due to their low-cost and high safety with non-flammable. Especially, it provides a high-power density up to 10 kW kg-1 (refers to the fast charge/discharge capability) which is higher than other electrolytes such as organic and ionic liquid electrolytes.(1) However, the major problem of the aqueous electrolyte system is the corrosion of metal current collector, especially aluminium (Al) foil. Even the Al foil is a promising current collector due to its low-cost, it can be corroded easily in aqueous solutions. Additionally, the resistive oxide film is spontaneously formed on the surface of Al foil, leading to low conductivity of the electrode.(2) To address this issue, we chose the graphite material for coating on the top and bottom of Al foil surface as a hydrophobic layer to prevent a penetration of the aqueous solution into Al foil surface that can be confirmed by contact angle measurement. In addition, we further studied the electrochemical performance of the as-prepared electrode in a half-cell configuration. Overall, not only protection of corrosion but also improvement of interfacial contact between electrode material layer and current collector are resulted from graphite protective layer, leading to low internal resistance and high-rate capability of the electrode. Moreover, the corrosion suppression of the current collector can enhance the cycling stability of the electrode. Finally, we fabricated the first prototype of cylindrical aqueous supercapacitor with the standardized size of 18650 for commercial-scale using the as-modified current collector which achieves capacitance of 18.9 F/cell at 50 mA and excellent cycling stability with almost 100% over 8,000 cycles at 250 mA.

KEYWORDS: Aqueous supercapacitors, anti-corrosion, hydrophobic protective layer

REFERENCES

C. Zhong, Y. Deng, W. Hu, J. Qiao, L. Zhang and J. Zhang, Chem. Soc. Rev., 44, 7484 (2015).

2. P. Chomkhuntod, M. Sawangphruk and K. Kongsawatvoragul, ECS Transactions, 97, 3 (2020).

Figure 1
240th ECS Meeting (Hirokazu Konishi)
Authors: Konishi Hirokazu
Published: July 2021

The electrochemical formation of Dy-Ni alloys was investigated in a molten CsCl-DyCl3 system at 973 K under a dry Ar gas atmosphere. Open-circuit potentiometry was performed with a Ni electrode after depositing Dy metal at 0.13 V(vs. Cs+/Cs) for 60 s. Five potential plateaus were observed at 0.34 V, 0.44 V, 0.54 V, 0.79 V and 0.91 V, which were considered to correspond to the potentials of two-phase coexisting states of different Dy–Ni alloys. Potentiostatic electrolysis was conducted at 0.31 V for 4 h and 0.41 V for 1 h using Ni plate electrodes, and XRD analysis indicated the formation of DyNi and DyNi2, respectively. After the formation of DyNi2 on the Ni plate electrodes, potentiostatic electrolysis were also conducted at 075 V and 0.85 V for 1 h. The formed DyNi2 was transformed to Dy2Ni7 and DyNi5 at 0.75 V, while DyNi5 was formed at 0.85 V.
Estimating Deformation Modulus and Bearing Capacity of Deep Soils from Dynamic Penetration Test
Authors: Shan Shihan , Pei Xiangjun , Zhan Weiwei
Published: July 2021

The dynamic penetration test (DPT) and the Menard pressuremeter test (PMT) have been widely used in geotechnical survey of deep soils for megadam foundations in western China. The DPT measures are not well utilized due to the lack of correction factors and of empirical relationships for deep soils. This study investigates the relationships between the corrected DPT blow counts (), pressuremeter modulus (EPMT), limit pressure (pL), deformation modulus (E0), and bearing capacity (fak) derived from the PMT results. Meanwhile, a nonlinear regression model is developed to predict the DPT correction factor (a) based on the raw DPT blow counts (N120) and the rod length (L) by integrating the available correction factors for shallow gravelly soils suggested by the code provisions and the deep soil data in this work. It is concluded that the proposed DPT correction factors match well with the code suggestions and the new compiled dataset, and the corrected DPT blow counts can be used to reasonably predict the engineering properties of deep sand and clay soils. Although the proposed correlations need to be tested among different soil types and regions, the results shed the light on in situ geotechnical tests and data utilization for deep and thick overburden.
Analysis of DNA Sequence Classification Using CNN and Hybrid Models
Authors: Gunasekaran Hemalatha , Ramalakshmi K. , Rex Macedo Arokiaraj A. , Deepa Kanmani S. , Venkatesan Chandran , Suresh Gnana Dhas C.
Published: July 2021

In a general computational context for biomedical data analysis, DNA sequence classification is a crucial challenge. Several machine learning techniques have used to complete this task in recent years successfully. Identification and classification of viruses are essential to avoid an outbreak like COVID-19. Regardless, the feature selection process remains the most challenging aspect of the issue. The most commonly used representations worsen the case of high dimensionality, and sequences lack explicit features. It also helps in detecting the effect of viruses and drug design. In recent days, deep learning (DL) models can automatically extract the features from the input. In this work, we employed CNN, CNN-LSTM, and CNN-Bidirectional LSTM architectures using Label and

K

-mer encoding for DNA sequence classification. The models are evaluated on different classification metrics. From the experimental results, the CNN and CNN-Bidirectional LSTM with

K

-mer encoding offers high accuracy with 93.16% and 93.13%, respectively, on testing data.
Application of Microfluidics in Immunoassay: Recent Advancements
Authors: Shi Yuxing , Ye Peng , Yang Kuojun , Meng Jie , Guo Jiuchuan , Pan Zhixiang , Bayin Qiaoge , Zhao Wenhao
Published: July 2021

In recent years, point-of-care testing has played an important role in immunoassay, biochemical analysis, and molecular diagnosis, especially in low-resource settings. Among various point-of-care-testing platforms, microfluidic chips have many outstanding advantages. Microfluidic chip applies the technology of miniaturizing conventional laboratory which enables the whole biochemical process including reagent loading, reaction, separation, and detection on the microchip. As a result, microfluidic platform has become a hotspot of research in the fields of food safety, health care, and environmental monitoring in the past few decades. Here, the state-of-the-art application of microfluidics in immunoassay in the past decade will be reviewed. According to different driving forces of fluid, microfluidic platform is divided into two parts: passive manipulation and active manipulation. In passive manipulation, we focus on the capillary-driven microfluidics, while in active manipulation, we introduce pressure microfluidics, centrifugal microfluidics, electric microfluidics, optofluidics, magnetic microfluidics, and digital microfluidics. Additionally, within the introduction of each platform, innovation of the methods used and their corresponding performance improvement will be discussed. Ultimately, the shortcomings of different platforms and approaches for improvement will be proposed.
Relationship between Air Pollution and Hospital Admissions for Chronic Obstructive Pulmonary Disease in Changchun, China: A Season-Stratified Case-Cross Study
Authors: Ju Ye , Ma Xinli , Li Huibo , Liu Shuang , Liya A. , Guo Xinrong
Published: July 2021

Background. This study aimed to explore the relationship between air pollution and hospital admissions for COPD in Changchun, a northeast city of China, in different seasons. Methods. The data on a total of 1,733 hospitalized patients living in Changchun with acute exacerbation of COPD from September 2013 to April 2018 were collected from a comprehensive 3A hospital of Changchun. Daily average concentrations of PM2.5, PM10, SO2, NO2, CO, and O3 were collected from the Department of Ecology and Environment of Jilin Province. The conditional logistic regression model was adopted to analyze the effect of air pollutant concentration on the number of hospitalized patients with COPD in different seasons. Results. The maximum OR value for most air pollutants emitted in spring was on lag day 4, in summer and autumn on lag day 3, and in winter on lag day 2. In spring, SO2 and NO2 were entered into the regression equation, and the OR (95%CI) was 0.992 (0.986–0.998) and 1.009 (1.002–1.017); in autumn, PM2.5, PM10, and SO2 were entered into the regression equation, and the OR (95%CI) was 1.005 (1.000–1.011), 0.995 (0.991–1.000), and 1.006 (1.001–1.011), respectively; and in winter, PM2.5 and PM10 were entered into the regression equation, and the OR (95%CI) was 1.008 (1.002–1.015) and 0.994 (0.988–0.999), respectively. Conclusion. The relationship between air pollution and hospital admission for COPD in Northeast China varies with different seasons. In spring, NO2 is likely to be the major risk factor for hospital admissions for COPD; in autumn, PM2.5 and SO2 are the major risk factors; and in winter, PM2.5 is the major risk factor.
A Novel Method for Automatic Extrinsic Parameter Calibration of RGB-D Cameras
Authors: Shi Qin , Song Huansheng , Sun Shijie
Published: July 2021

Calibration of extrinsic parameters of the RGB-D camera can be applied in many fields, such as 3D scene reconstruction, robotics, and target detection. Many calibration methods employ a specific calibration object (i.e., a chessboard, cuboid, etc.) to calibrate the extrinsic parameters of the RGB-D color camera without using the depth map. As a result, it is difficult to simplify the calibration process, and the color sensor gets calibrated instead of the depth sensor. To this end, we propose a method that employs the depth map to perform extrinsic calibration automatically. In detail, the depth map is first transformed to a 3D point cloud in the camera coordinate system, and then the planes in the 3D point cloud are automatically detected using the Maximum Likelihood Estimation Sample Consensus (MLESAC) method. After that, according to the constraint relationship between the ground plane and the world coordinate system, all planes are traversed and screened until the ground plane is obtained. Finally, the extrinsic parameters are calculated using the spatial relationship between the ground plane and the camera coordinate system. The results show that the mean roll angle error of extrinsic parameter calibration was −1.14°. The mean pitch angle error was 4.57°, and the mean camera height error was 3.96 cm. The proposed method can accurately and automatically estimate the extrinsic parameters of a camera. Furthermore, after parallel optimization, it can achieve real-time performance for automatically estimating a robot’s attitude.
A Study on the Flexural Behaviour of Geopolymer Lightweight Eco‐Friendly Concrete Using Coconut Shell as Coarse Aggregate
Authors: Nithya S. , Gunasekaran K. , Sankar G.
Published: July 2021

This paper presents the flexural behaviour of concrete containing ground granulated blast furnace slag (GGBS) as a binder, manufactured sand (M‐sand) as a fine aggregate, and coconut shell (CS) and crushed stone aggregate (CSA) as coarse aggregates. Alkaline activator sodium hydroxide with 10 molarity and sodium silicate were used in a weighing proportion of 1 : 2.5 to produce structural grade concrete. Out of 12 beams cast, 6 were used to study geopolymer coconut shell concrete (GPCSC) beam behaviour and 6 were used to study geopolymer conventional concrete (GPCC) beam behaviour. Data presented include cracking behaviour, ultimate moment capacitates, deflection behaviour, ductility ratio, and end rotation of the beam. Laboratory investigations show encouraging results, and it can be summarized that coconut shell has good potential as a coarse aggregate for the production of structural grade geopolymer lightweight coconut shell concrete.
Tunicamycin-Induced Endoplasmic Reticulum Stress Promotes Breast Cancer Cell MDA-MB-231 Apoptosis through Inhibiting Wnt/β-Catenin Signaling Pathway
Authors: You Zhongsheng , He Linkang , Yan Nianlong
Published: July 2021

Triple negative breast cancer (TNBC) has significantly threatened human health. Many aspects of TNBC are closely related to Wnt/β-catenin pathway, and cell apoptosis induced by endoplasmic reticulum stress (ER stress) in TNBC may act as a potential target of non-chemotherapy treatment. However, how ER stress interacts with this pathway in TNBC has not yet been understood. Here, the tunicamycin and LiCl have been applied to MDA-MB-231. The related proteins’ expression was measured by western blotting. Moreover, acridine orange/ethidium bromide (AO/EB) staining was applied to test the apoptosis degree of the cells, and cell viability was tested by MTT experiment. Then, we found the ER stress and apoptosis degree of MDA-MB-231 were induced after treatment with tunicamycin. Besides, tunicamycin dose dependently inhibited both Wnt/β-catenin pathway and cells viability. Licl, an activator of Wnt/β-catenin signaling pathway, could significantly inhibit cell apoptosis. In conclusion, our study found that the activation of ER stress could promote the MDA-MB-231 apoptosis by repressing Wnt/β-catenin pathway, which provides some promising prospects and basic mechanism to the further research.
Body Mass Index Trajectories during 6–18 Years Old and the Risk of Hypertension in Young Adult: A Longitudinal Study in Chinese Population
Authors: Teng Haoyue , Hu Jia , Ge Wenxin , Dai Qiling , Liu Ji , Xiao Chengqi , Yin Jieyun , Zhu Xiaoyan
Published: July 2021

Background. Overweight/obesity in childhood is suggested to increase the risk of hypertension later in life. We aimed to assess whether and how body mass index (BMI) trajectories during 6–18 years of age are associated with hypertension in young adulthood (18–37 years) in the Chinese population. Methods. Based on the China Health and Nutrition Survey (CHNS), a total of 1,872 participants who received ≥2 measurements of BMI during 6–18 years and had assessment of blood pressure (BP) in young adulthood were included. BMI trajectories were explored using latent class growth mixture models, and associations between identified trajectories with hypertension in young adulthood were examined by logistic regression analyses. Results. Five heterogeneous BMI trajectories were identified: the low slow-increasing (20.03%), low moderate-increasing (56.14%), low rapid-increasing (17.04%), moderate-increasing (3.63%), and elevated-decreasing (3.15%) groups. Compared with the low slow-increasing group, another three increasing groups had gradually elevated risk of hypertension, yielding maximally adjusted odds ratio (95% confidence interval) (OR (95% CI)) of 2.48 (1.39–4.42), 3.24 (1.66–6.31), and 3.28 (1.19–9.08), respectively, whereas the elevated-decreasing group reversed overweight/obesity to normal weight in childhood, rendering its association with hypertension as not statistically significant (OR (95% CI) = 2.74 (0.98–7.65)). Conclusion. Our study indicates that there are varied BMI trajectories from childhood to adulthood and that an elevated BMI trajectory during childhood is related with an increased risk of hypertension in young adulthood. In contrast, weight loss of children with high initial BMI may mitigate or reverse the risk. Our findings emphasize the importance of BMI continuous monitoring during early life.
Impact of Physical Activity on Oxidative Stress Markers in Patients with Metastatic Breast Cancer
Authors: Delrieu Lidia , Touillaud Marina , Pérol Olivia , Morelle Magali , Martin Agnès , Friedenreich Christine M. , Mury Pauline , Dufresne Armelle , Bachelot Thomas , Heudel Pierre-Etienne , Fervers Béatrice , Trédan Olivier , Pialoux Vincent
Published: July 2021

Purpose. Regular physical activity (PA) can affect oxidative stress, known to be involved in carcinogenesis. The objective of this study was to evaluate the associations between a six‐month PA intervention and oxidative stress biomarkers, PA, and clinical outcomes in patients with metastatic breast cancer. Methods. Forty‐nine newly diagnosed patients with metastatic breast cancer were recruited for a single‐arm, unsupervised, and personalized six‐month walking intervention with activity tracker. PA level and PA fitness, plasma concentrations of DNA oxidation (8OhdG), lipid peroxidation (MDA), and protein oxidation (AOPP), plasma activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase, plasma and leucocyte activities of myeloperoxidase (MPO) and NADPH oxidase (NOX), and clinical markers of tumor progression (RECIST criteria) were measured at baseline and after the six‐month intervention. Results. GPX activity (+17%) and MDA (+9%) significantly increased between baseline and the end of the intervention. Changes in PA level and fitness were significantly positively correlated with changes in plasma GPX and significantly negatively with changes in NOX in the leucocytes. Plasma MDA was significantly higher (+20%) whereas plasma AOPP was lower (‐46%) for patients with tumor progression or that died during the six months as compared to patients without progression. Conclusion. A six‐month PA intervention may be potentially beneficial in metastatic breast cancer patients for enhancing antioxidant enzyme activity and decreasing prooxidant enzyme activity. Moreover, AOPP and MDA could also be favorable and unfavorable biomarkers, respectively, since they are associated with disease progression and fitness level in this population. This trial is registered with NCT number: NCT03148886.
Giant Cell Urothelial Carcinoma of Bladder
Authors: Wijesinghe Harshima Disvini , Malalasekera Ajith
Published: July 2021

Giant cell urothelial carcinoma is a rare variant of bladder cancer recognized by the current World Health Organization classification of urologic tumours. It is an aggressive tumour with a poor prognosis that usually presents at an advanced stage. It is characterized histologically by pleomorphic giant cells. We discuss a case of giant cell urothelial carcinoma presenting at an early stage in a previously well 62-year-old woman. Histology showed a tumour comprising pancytokeratin positive bizarre mononuclear and multi-nuclear giant cells admixed with areas of conventional urothelial carcinoma and carcinoma in situ. Three-month follow-up cystoscopy and magnetic resonance imaging showed no evidence of recurrence or pelvic lymphadenopathy.
Tear Film Proteome of Healthy Domestic Cats
Authors: Veloso Jéssica Fontes , Brandão Guedes Paula Elisa , Lacerda Luciana Carvalho , Santana Juliano Oliveira , Mora-Ocampo Irma Yuliana , Pirovani Carlos Priminho , Oriá Arianne Pontes , Munhoz Alexandre Dias , Alberto Carlos Renata Santiago
Published: July 2021

The aim of this study was to investigate the proteins found in tear film of healthy domestic cats. Schirmer tear test strips were used to collect tear samples of twelve healthy cats, which were mixed, centrifuged, and placed in a single 1.5 mL microtube that was frozen at −20°C, until analysis by two-dimensional polyacrylamide gel and mass spectrometry associated with high-performance liquid chromatography. The resulting spectra were analyzed and compared with the Swiss-Prot search tool. Forty peptides were detected in the analyzed protein fragments of 90 spots, with 16 proteins identified. Of these, the authors confirmed what has been already found in other studies: lactotransferrin, serum albumin, allergenic lipocalins, and neutrophil gelatinase-associated lipocalin. Others were considered novel in tear film samples of all species: cyclin-dependent protein kinase, serine/arginine repetitive matrix protein, apelin receptor, secretory protein related to C1q/TNF, Wee1, α-1,4 glucan phosphorylase, and WD repeat domain 1. The network was divided into 11 clusters, and a biological function was assigned. Most of the proteins have functions in the defense and maintenance of feline ocular surface homeostasis. Serum albumin is a bottleneck protein, with a high betweenness value. This paper is a pioneer in reporting, in-depth, the tear film proteome of domestic cats.
A Novel Decoding Method for the Erasure Codes
Authors: Tang Dan , Cai Hongliang
Published: July 2021

The erasure codes are widely used in the distributed storage with low redundancy compared to the replication method. However, the current research studies about the erasure codes mainly focus on the encoding methods, while there are few studies on the decoding methods. In this paper, a novel erasure decoding method is proposed; it is a general decoding method and can be used both over the multivariate finite field and the binary finite field. The decoding of the failures can be realized based on the transforming process of the decoding transformation matrix, and it is convenient to avoid the overburdened visiting problem by tiny modification of the method. The correctness of the method is proved by the theoretical analysis; the experiments about the comparison with the traditional methods show that the proposed method has better decoding efficiency and lower reconstruction bandwidth.
A Case of Idiopathic Dense Vitreous Hemorrhage: Suspected Rupture of a Large Retinal Arterial Macroaneurysm on the Optic Disc
Authors: Takahashi Shizuka , Nishida Kentaro , Sakaguchi Hirokazu , Nishida Kohji
Published: July 2021

We report a novel case of vitreous hemorrhage associated with suspected rupture of 2-disc-diameter retinal arterial macroaneurysm on the optic disc. A 90-year-old woman presented with blurred vision (sudden onset) in her left eye. Examination of the fundus revealed acute onset vitreous hemorrhage of unknown origin without retinal detachment. She underwent vitrectomy, but after excision of the dense vitreous hemorrhage, a 2-disc-diameter hematoma appeared on the optic disc and was removed promptly. Because the bleeding at the base of the hematoma was of arterial origin and pulsating, the first vitrectomy could not achieve hemostasis. Five days after the first surgery, we performed a second vitrectomy. This revealed a subretinal hemorrhage along the superior and inferior arcade vessels and a macular hole, which was almost completely closed with an inverted internal limiting membrane flap. Unfortunately, the macular hole reopened 41 days after the second surgery. In patients presenting with only a large hematoma on the optic disc, it might be prudent to leave the hematoma. However, this large retinal arterial macroaneurysm was on a rare location on the optic disc, making it doubly difficult for the surgeons to diagnose and choose the best option intraoperatively. The differential diagnosis for dense vitreous hemorrhage of unknown origin should include a large retinal arterial macroaneurysm on the optic disc.