bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrogen and phosphorus release from paper mill biosolids as affected by material source and soil type under controlled incubation
Authors: Gagnon Bernard , Ziadi Noura
Published: July 2020

Combined paper mill biosolids (PB) are a well-known fertilizing source of nitrogen (N) and phosphorus (P). Many jurisdictions have established default values for estimating their agronomic N and P contribution, but nutrient release can vary with their chemical properties, and this has been little studied. The objective of this incubation study was to compare four PB of different sources along with a de-inking paper sludge (DPS) for their N and P release in three contrasting soils under controlled conditions (25 °C, 60% water-filled pore space). Treatments consisted of PB or DPS at 50 Mg fresh mass ha−1, PB at 30 Mg fresh mass ha−1 plus inorganic N to supply 100 kg available N ha−1, inorganic NP fertilizer, and an unfertilized control. Measurements of NO3 + NH4-N were made after 3 d and 1, 2, 3, 4, 6, 8, 12, and 16 wk of incubation. Mehlich-3 P was measured after 2 and 16 wk of incubation. Nitrogen mineralization generally declined a few days after PB addition and then gradually and constantly increased. The P mineralization of PB also increased with time. By the end of incubation, net N and P release averaged 30% (7%–49%) and 75% (16%–116%) of the NP fertilizer, respectively. The intensity of release, however, varied with material characteristics and soil type. Mineral N addition to the 30 Mg PB ha−1 promoted N release to a level comparable to NP fertilizer. Soil N immobilization occurred with the DPS application. Current default N value used for PB in Quebec and Ontario is appropriate but not P.
Plant DNA barcoding necessitates marker-specific efforts to establish more comprehensive reference databases
Authors: Kolter Andreas , Gemeinholzer Birgit
Published: July 2020

The problem of low species-level identification rates in plants by DNA barcoding is exacerbated by the fact that reference databases are far from being comprehensive. We investigate the impact of increased sampling depth on identification success by analyzing the efficacy of established plant barcode marker sequences (rbcL, matK, trnL-trnF, psbA-trnH, ITS). Adding sequences of the same species to the reference database led to an increase in correct species assignment of +10.9% for rbcL and +19.0% for ITS. Simultaneously, erroneous identification dropped from ∼40% to ∼12.5%. Despite its evolutionary constraints, ITS showed the highest identification rate and identification gain by increased sampling effort, which makes it a very suitable marker in the planning phase of a barcode study. The limited sequence availability of trnL-trnF is problematic for an otherwise very promising plastid plant barcoding marker. Future developments in machine learning algorithms have the potential to give new impetus to plant barcoding, but are dependent on extensive reference databases. We expect that our results will be incorporated into future plans for the development of DNA barcoding reference databases and will lead to these being developed with greater depth and taxonomic coverage.
Segregated interactions in urban and online space
Authors: Dong Xiaowen , Morales Alfredo J. , Jahani Eaman , Moro Esteban , Lepri Bruno , Bozkaya Burcin , Sarraute Carlos , Bar-Yam Yaneer , Pentland Alex
Published: July 2020

Urban income segregation is a widespread phenomenon that challenges societies across the globe. Classical studies on segregation have largely focused on the geographic distribution of residential neighborhoods rather than on patterns of social behaviors and interactions. In this study, we analyze segregation in economic and social interactions by observing credit card transactions and Twitter mentions among thousands of individuals in three culturally different metropolitan areas. We show that segregated interaction is amplified relative to the expected effects of geographic segregation in terms of both purchase activity and online communication. Furthermore, we find that segregation increases with difference in socio-economic status but is asymmetric for purchase activity, i.e., the amount of interaction from poorer to wealthier neighborhoods is larger than vice versa. Our results provide novel insights into the understanding of behavioral segregation in human interactions with significant socio-political and economic implications.
Non-Abelian firewall
Authors: Singleton Douglas
Published: July 2020

A simple, closed-form solution to the Yang-Mills field equations is presented which has a non-Abelian firewall — a spherical “horizon” where the energy density diverges. By the gravity/gauge duality, this non-Abelian firewall implies the existence of a gravitational firewall. Gravitational firewalls have been proposed as a way of resolving the information loss paradox, but at the cost of violating the equivalence principle.
Buckling Analysis of a Bi-Directional Strain-Gradient Euler–Bernoulli Nano-Beams
Authors: Çelik Murat , Artan Reha
Published: July 2020

Investigated herein is the buckling of Euler–Bernoulli nano-beams made of bi-directional functionally graded material with the method of initial values in the frame of gradient elasticity. Since the transport matrix cannot be calculated analytically, the problem was examined with the help of an approximate transport matrix (matricant). This method can be easily applied with buckling analysis of arbitrary two-directional functionally graded Euler–Bernoulli nano-beams based on gradient elasticity theory. Basic equations and boundary conditions are derived by using the principle of minimum potential energy. The diagrams and tables of the solutions for different end conditions and various values of the parameters are given and the results are discussed.
Effects of Nanoparticles on Viral Infection — A Review
Authors: Chowdhury Mohammad Asaduzzaman , Hossain Nayem , Kashem Mohammod Abul , Shahid Md. Abdus , Alam Ashraful
Published: July 2020

Viruses like COVID-19 are very small. They are nanometer in diameter. To detect and prevent them, nanotechnology is a crucial tool. This review paper reviews the recent progress of nanomedicine in fighting COVID-19. At the beginning, how nanoparticle works in our body is described here. Recent observations of these medicines’ performance are illustrated with some practical case studies. Different types of vaccines based on nanoparticles and their potentiality of fighting COVID-19 are also described. What can be the potential challenges for this technology along with prospects are also discussed. At the end, some nanomedicines have been suggested that can be effective to fight the virus. This paper can be used as a state-of-the-art at this critical moment to the globe for promising nanotechnology-based therapy related to the survival of people from coronavirus.
Theta series and weight enumerator over an imaginary quadratic field
Authors: Ankur  , Shum K. P.
Published: July 2020

In this paper, we consider an imaginary quadratic field [Formula: see text] with [Formula: see text] (mod [Formula: see text]). In particular, we study the ring of integers corresponding to the field [Formula: see text] and visualize the form of [Formula: see text]. We also consider lattices over the ring of integers [Formula: see text] and discuss the theta series to see its relation with the weight enumerator. As a consequence, we will see how the theta series differs for different [Formula: see text] and [Formula: see text].
QoS-aware simulation job scheduling algorithm in virtualized cloud environment
Authors: Li Zhen , Chen Bin , Liu Xiaocheng , Ning Dandan , Qiu Xiaogang
Published: July 2020

Cloud computing is attracting an increasing number of simulation applications running in the virtualized cloud data center. These applications are submitted to the cloud in the form of simulation jobs. Meanwhile, the management and scheduling of simulation jobs are playing an essential role to offer efficient and high productivity computational service. In this paper, we design a management and scheduling service framework for simulation jobs in two-tier virtualization-based private cloud data center, named simulation execution as a service (SimEaaS). It aims at releasing users from complex simulation running settings, while guaranteeing the QoS requirements adaptively. Furthermore, a novel job scheduling algorithm named adaptive deadline-aware job size adjustment (ADaSA) algorithm is designed to realize high job responsiveness under QoS requirement for SimEaaS. ADaSA tries to make full use of the idle fragmentation resources by tuning the number of requested processes of submitted jobs in the queue adaptively, while guaranteeing that jobs’ deadline requirements are not violated. Extensive experiments with trace-driven simulation are conducted to evaluate the performance of our ADaSA. The results show that ADaSA outperforms both cloud-based job scheduling algorithm KCEASY and traditional EASY in terms of response time (up to 90%) and bounded slow down (up to 95%), while obtains approximately equivalent deadline-missed rate. ADaSA also outperforms two representative moldable scheduling algorithms in terms of deadline-missed rate (up to 60%).
Recent Developments in the Search for Alternative Low-Global-Warming-Potential Refrigerants: A Review
Authors: Siddiqui M. U. , Owes Amro , Al-Amri F. G. , Saeed Farooq
Published: July 2020

Conventionally, the CFC-type refrigerants were used until Montreal Protocol which stated that CFC refrigerants cause ozone depletion and should be replaced with alternative refrigerants. The alternative refrigerants are safe for ozone but they have comparatively high flammability, toxicity and global warming potential. Thus they need careful handling. In Kyoto Protocol, it was stated that the currently used refrigerants with high global warming potential need to be replaced with yet other alternative refrigerants with low global warming potential. This paper comprehensively reviews those recent studies that focused on the possible replacement of currently in-use refrigerant with a comparatively more environmental-friendly alternative refrigerant. Initially, the progression of refrigerants through different generations has been described and discussed. A list of currently in-use refrigerants has been presented. Then, the scientific developments for the replacement of listed refrigerants are thoroughly reviewed and critically analyzed. From the comprehensive review, it was found that R1234yf has the most potential to be a suitable low-flammable replacement for R134a for domestic refrigeration and automotive air-conditioning systems. Also, R32 has the most potential to be a suitable alternative of R410A.
Thermal Efficiency Enhancement of an R-32 Air Conditioner and the Ultrasonic Wave Technique
Authors: Chaiyat Nattaporn
Published: July 2020

This work presents a technique to improve the thermal performance of an R-32 air conditioner by using ultrasonic waves. Two 1-TR air conditioners — one with and one without 40[Formula: see text]kHz/50[Formula: see text]W ultrasonic generators — were tested under controlled conditions in a 3.6[Formula: see text]m [Formula: see text][Formula: see text]m [Formula: see text][Formula: see text]m room. The air temperature and humidity conditions entering the condenser and evaporator coils were controlled under 12 conditions to mimic the climate of Thailand. The testing results indicated that the average energy efficiency ratio (EER) of the modified ultrasonic R-32 air conditioner unit was 3.685[Formula: see text]kWth/kWe and the normal R-32 unit without the ultrasonic generators was 3.375[Formula: see text]kWth/kWe. The testing conditions also indicated that the cooling efficiency of the modified system could be increased by approximately 7.69%. Moreover, the convective heat transfer coefficient of the modified ultrasonic R-32 unit was approximately 17.36% higher than that of the normal R-32 unit without the ultrasonic generators because the ultrasonic waves could increase the turbulence in the refrigerant flow and decrease the condensed water at the fan coil unit. In terms of economic results, the payback period of the modified unit based on the climate of Thailand ranged from 0.8–1.2 y, leading to a savings in power consumption of approximately 400–620[Formula: see text]kWh/y.
V2O5 Film Embedded Carbon Fiber Paper Synthesized By Sol Process As Highly Pseudocapacitive Electrode for Energy Storage
Authors: Azadian Farshad , Rastogi Alok C
Published: July 2020

In this work, by utilizing carbon paper having cress-crossing fibrous network structure as a template, high porosity crystalline V2O5 film electrode is synthesized using a simple sol precursor dip-dry-anneal method. Detailed cyclic voltammetry (CV), charge-discharge (CD) and impedance measurements were carried out in acetonitrile +LiClO4 electrolyte. CV data identify V5+/V4+ and V4+ /V3+ redox peaks which yield high specific capacitance of 800 Fg-1. These values are significantly higher compared with the similarly processed V2O5 over flat stainless steel (SS) foil substrate which proves the efficacy of carbon fiber paper for structuring V2O5 and in enhancing its specific capacitance. The CD data show high (>92%) Coulomb efficiency highly reversible redox reactions compared to the V2O5 film over SS. The major contributing factor was multifaceted access to electrolyte ions which enhances redox rates via charge transfer in response to electron injection or extraction via carbon fiber network.
The Hybrid Energy Conversion and Storage of Nickel Metal Hydride (NiMH) Batteries
Authors: Kongsawatvoragul Ketsuda , Sawangphruk Montree
Published: July 2020

Nickel metal hydride (NiMH) batteries are one type of batteries which are widely used commercially for various applications for example hybrid cars. NiMH battery consists of nickel hydroxide/oxyhydroxide (Ni(OH)2/NiOOH) cathode and lanthanum (La) alloy anode. Many recent studies focused on developing the storage capacity, the self-discharge, and the degradation of performance of NiMHs at a high temperature since they are cheaper than lithium-ion (Li-ion) batteries. Here, we have integrated the sunlight conversion and the storage abilities of Ni(OH)2 coated on transparent fluorene-doped tin oxide (FTO) glass for photoactive NiMH battery. This finding may lead to further develop novel photoactive NiMHs.
MnCo2O4 Nanofibers as Efficient Photo-electrocatalyst for Oxygen Evolution Reaction and Oxygen Reduction Reaction
Authors: Tomon Chanikarn , Sarawutanukul Sangchai , Duangdangchote Salatan , Krittayavathananon Atiweena , Sawangphruk Montree
Published: July 2020

Photoactive bimetal oxide catalysts towards oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) activities have not yet been comprehensively investigated. Herein, this work presents the MnCo2O4 nanofiber using as a photo-electrocatalyst for OER and ORR. After irradiation with visible light, the MnCo2O4 decreases ca. 17.1% and 15.4% in overpotential of OER and ORR, respectively, while the overpotential of the Co3O4 is reduced ca. 8.6% and 6.4% towards OER and ORR processes, respectively. These results suggest that MnCo2O4 can enhance OER/ORR performances with two-fold higher than Co3O4 under the light illumination. Due to the mixed valence states of Mn2
+ and Mn3
+ in its spinel structure, the MnCo2O4 has lower band gap energy (1.7 eV) than the Co3O4 nanofiber (2.0 eV). This narrower band gap can facilitate electron transfer from the valence band to the conduction band. Moreover, the photogenerated MnCo2O4
* holes can accelerate the reaction with OH- and H2O which subsequently enhances OER performance.
Influence of Electrode Density on the Microstructural NCA Positive Electrode for Scalable 18650 Li-Ion Batteries
Authors: Sarawutanukul Sangchai , Tomon Chanikarn , Phattharasupakun Nutthaphon , Sawangphruk Montree
Published: July 2020

Calendaring process is one of the most important part in the line production of 18650 lithium ion battery which densifies the electrode and promotes consistency to the metal current corrector. However, this process promotes the tortuosity of the void space network in the primary ion transportation and facilitate tradeoffs between electrode density and rate capability. The aim of this work to understanding the impact of density and porosity on electrode kinetics and authorizing cell designs with denser electrodes to improve capacity and energy density, this study investigates the effect of high and low limit of pressure force in the calendaring process between 400 and 2000 kg cm2 on the electrode properties such as density and porosity of LiNi0.8Co0.15Al0.05O2 (NCA) electrode. It was found that as the applied pressure force increased, the qualitative properties of NCA electrode are increased via the particle packing, porosity, and density. These factors directly affect to Li-ion diffusion in electrode and Li-ion depletion in the electrolyte interphases which will improve the energy density and power density. However, the overpressure force leads to increase in micro-cracking inside the NCA particle, tortuosity and over-packed of the NCA electrode which can obstructed the electrode capacity at high C-rates. Based on this result, the low-level compaction was proposed to mitigate the limiting factors. The development of the energy-power density in an 18650 cell was used to demonstrate how to further study into the electrode parameters in cell engineering.
Tailored SiNx-based Anode Processing for Li-Ion Batteries
Authors: Bapat Shalmali , Oezcan Fatih , Kilian Stefan Oliver , Wiggers Hartmut , Segets Doris
Published: July 2020

In order to successfully implement promising new battery materials at industrial production rates, it is important to provide suitable recipes for information. Typically, active materials are processed as dispersions in liquid-phase together with further additives aiming at the improvement of battery slurry properties. Interactions between particles and dispersing liquid(s) are decisive for electrode manufacturing and performance. Hence, we combined Hansen parameter approach with analytical centrifugation for dispersing SiNx nanoparticles as promising next generation battery material. Suitable probe liquids were chosen for the identification of beneficial dispersion properties. Electron microscopy was employed for a first qualitative plausibility analysis. Diacetone alcohol showed favorable dispersion properties for SiNx particles while toluene was found to be not suitable. Our approach and findings are an excellent starting point for the systematic characterization and evaluation of new battery materials with regard to processability.
A Comprehensive Comparison of the Phase Change Material-Based Internal and External Cooling Systems
Authors: Zhao Rui , Liu Jie , Ma Fai
Published: July 2020

In this study, phase change material (PCM) is used internally and externally in managing the heat generation of cylindrical Li-ion batteries during high rate discharges. Both internal and external cooling systems are thoroughly compared in their cooling effect on batteries of different sizes (18650, 21700, and 26650) and radial thermal conductivities, their cooling effect on battery packs of different layers (2, 4, and 8 layers of batteries), the necessity using high thermally conductive PCM in the cooling systems, as well as their weight and volume added to the battery system. Results show that the internal cooling system is more suitable for high specific energy applications. It is less sensitive to the battery radial thermal conductivity and performs better for large battery packs and thick batteries. While the external cooling system is more space-saving and suitable for 2-layer battery packs with forced convection applied at the battery pack side walls. However, its performance deteriorates as the thermal conductivity of PCM and batteries decreases.
Minimizing Oxygen Permeation in Metal-Chelate Flow Batteries
Authors: Robb Brian H. , Waters Scott E. , Marshak Michael P.
Published: July 2020

Coulombic efficiency (CE) losses within redox flow batteries (RFBs) decrease system performance and can indicate possible long-term capacity fade. Here, we discuss improvements made to lab-scale redox flow battery construction and operating conditions. The augmented RFB set-up limits the oxidation of highly reducing species by minimizing atmospheric oxygen permeation and subsequently demonstrates improved performance. The addition of sealed compression fittings, peristaltic pumps, and the operation of the battery in an N2 glovebox leads to near quantitative CE for a chelated Cr electrolyte, improving from previously utilized systems which operated as low as 93.2% CE at low current densities. The importance of preventing O2 permeation is exemplified and the battery efficiencies in an ambient atmospheric and nitrogen environment with different electrolyte reservoir apparatuses are contrasted. Possible sources of the remaining CE losses are also discussed.
Improving Interfacial Contact within Solid-State Lithium Batteries using the Composite Materials at the Cathode Produced by a Scalable Mechanofusion Process
Authors: Bunyanidhi Panyawee , Sawangphruk Montree
Published: July 2020

Even though PEO-based electrolytes have been interested as a solution for developing the next-generation lithium-based batteries, their performances are still far from the commercial need and requirement. One of the major challenges limiting the cycling performance of all-solid-state batteries is at the interfacial contact of the electrode and the ceramic electrolyte, not like in the case of liquid electrolyte. To address this poor solid-solid contact, we introduce a cathode composite concept by combining both ceramic filler and polymer with LiFePO4 (LFP) cathode material. Herein, the garnet (Li7La3Zr2O12, LLZO) ceramic is well mixed with LFP cathode material using a new solid-solid mixing process namely a mechano-fusion technique. PEO is also used as a binder during the cathode preparation. The PEO-based composited electrolyte layer (filled with LLZO) and the composite material used at the cathode are stacked layer-by-layer and hot-pressed. As a result, this composite concept produced by a scalable mechanofusion process could be useful for further develop high-performance the all-solid-state batteries.
Advanced Hybrid 18650 Li-Ion Capacitors of Lithium Titanate (LTO)/Activated Carbon
Authors: Aphirakaramwong Chalita , Sawangphruk Montree
Published: July 2020

There are remarkedly increasing demands in electronic devices including the portable electronic devices and electric vehicles (EVs). Therefore, the energy storages that can store energy efficiently with both high energy and power densities with good cyclability as display in batteries and supercapacitors are needed. The hybrid energy storages are one of the energy storage devices merging the advantages of both batteries and supercapacitors to overcome those lacking properties in each device. Thus, the lithium-ion hybrid capacitors (LICs) are introduced consisting battery-type as negative electrode and supercapacitors-type as positive electrode. There are many selections of electrode materials that can be used in the LICs such as carbonaceous materials and lithium titanate (LTO). The cell configuration was developed and fabricated in organic electrolyte since coin-cell to cylindrical cell. Herein, the 18650 configuration is introduced as hybrid energy storage consisting LTO and activated carbon as negative and positive electrodes, respectively. Moreover, the additional additives in electrolyte are also studied and investigated to improve the electrochemical performances to the hybrid capacitors.
Biomedical Application Via Implantable Devices By CMOS-Compatible Glucose Fuel Cells Using Carbon Nano Horn
Authors: Islam Md. Zahidul , Arata Shigeki , Hayashi Kenya , Kobayashi Atsuki , Momoi Yuichi , Niitsu Kiichi
Published: July 2020

Solid-state complementary metal oxide semiconductor (CMOS)-compatible glucose fuel cells, with carbon nano horn (CNH) films with different amounts of CNH (wt.%) and glucose solution were investigated. CNH content of 3 wt.% with 30 mM glucose solution was found the highest open circuit voltage (OCV) of 420 mV, a power density of 2.83 µW/cm2 and current density of 6.73 µA/cm2. This is the highest value compared with the conventional glucose fuel cell. The OCV and power density increased together with the fuel cell concentration. The developed fuel cell uses materials that are bio-compatible with the human body (CNH-glucose). As a result, OCV of 420 mV with a CNH content of 3 wt.% while improvements in the performance of the CMOS-compatible fuel cell were obtained, and the parameters affecting the performance of the fuel cell were identified. This glucose fuel cell was fabricated using CMOS semiconductor processes on a silicon wafer. This work presents a (5 mm × 5 mm) solid-state CMOS compatible glucose fuel cell that 420 mV of OCV. It is the highest value for a glucose fuel cell when the anode area is (4.2 mm × 4.6 mm). These findings are significant in realizing mobile or implantable devices that can be used for biomedical applications.
Integrated Titanium-Carbon Nanotube Conductors via Joule-Heating Driven Chemical Vapor Deposition
Authors: McIntyre Dylan J. , Leggiero Anthony P. , Hailstone Richard K. , Puchades Ivan , Cress Cory D. , Landi Brian J.
Published: July 2020

Ti is known to exhibit excellent interfacial interaction with CNTs, and enhances the electrical performance for Cu-CNT hybrids. A simple route for depositing Ti to form integrated Ti-CNT bulk conductors is warranted to increase the total metal:CNT interfacial contact area. Herein, Joule-heating driven CVD using a cyclopentadienyl(cycloheptatrienyl) titanium(II) precursor is reported. Successful penetration of Ti throughout a 30 µm-thick CNT network is achieved. Deposition morphology can be tuned from local coatings along CNT bundles to continuous surface films, dependent on starting precursor amount. The Ti coatings are stable on the CNTs upon exposure to temperature of 300 °C for 1 hour in 95% Ar/ 5% H2. Electroplating to form a Cu-Ti-CNT hybrid (97.1%/0.9%/2% wt/wt) achieved a conductivity of 32.3 MS/m with a TCR of 3.18 × 10-3 K-1. The fabrication of integrated Ti-CNT bulk conductors enables a path forward for metal-Ti-CNT designs with improved metal:CNT interfaces for enhanced electrical performance.
(Keynote) Terahertz Nanoplasmonics Technology: Physics, Applications, and Commercialization
Authors: Shur Michael
Published: July 2020

Nanoscale Field Effect Transistors (FETs) operating in the Terahertz (THz) range of frequencies rely on the excitation and rectification of the oscillations of the electron density in the device channels - plasma waves. TeraFETs are expected to enable numerous potential applications in THz sensing, imaging, and communications. A new emerging application is for cyber hardware security to distinguish between faked and genuine VLSI chips and predict the VLSI reliability.
Carbon Nanotube Metal Polymer Composites for Flexible Active Interconnects
Authors: Park Junsung , Liu Xueqing , Ytterdal Trond , Kim Jin Ho , Xu Jimmy , Shur Michael
Published: July 2020

We report on the fabrication and characterization of metal polymer carbon nanotube (MPCNT) composites for flexible active interconnects. Our experiments demonstrated that such carbon nanotube (CNT)-reinforced polymer-metal composites have several times higher tolerance to bending strains than the metal-polymer composites without the CNTs layer. Since CNT-polymer layer is electrically insulated from the metal layer until destructive breakdown, it is feasible to fabricate electronic components isolated from the metal layer in the MPCNT composites. Thus, the MPCNT composites-based interconnects could be utilized as a platform for CNTs-based sensors and CNT Thin Film Transistors (TFTs). To estimate the electrical characteristics of the MPCNT devices, we developed the compact unified charge control model (UCCM) for CNT TFTs. The model was validated by comparison of the simulated results with experimental data reported earlier. We further investigated humidity sensing based on the CNT-Poly(N-isopropylacrylamide) (PNIPAm) composites, and demonstrated the potential for the MPCNT sensing applications.
Corrosion Rate Investigation of Magnesium and Some of its Alloys in 0.9% NaCl Solution
Authors: Ostapenko Gennady I.
Published: July 2020

The corrosion rate of magnesium and some its alloys was investigated by EIS and potentiodynamic methods. It is shown that the corrosion rate value is in the range from units to hundredths of mm×year-1 and is mostly consistent with the data of other researchers. A significant shift in the corrosion potential in the anode direction after cathodic polarization is explained by the kinetic difficulties of the corrosion reaction in the layer of reaction products. A corrosion diagram is constructed, overvoltages of hydrogen evolution and dissolution of magnesium are estimated.
Investigation of AISI 316 Stainless Steel Corrosion in Perchloric Acid
Authors: Ostapenko Gennady I.
Published: July 2020

The corrosion rate of AISI 316 SS in 1 M perchloric acid with the addition of benzotriazole as a corrosion inhibitor was investigated. It was shown that benzotriazole is a cathodic inhibitor, i.e. slows down the cathodic depolarization reaction. The inhibition efficiency reaches about 40% with an inhibitor concentration of about 10-2 M.
Investigation of Au-Ag-Cu Alloy Electrodeposition to Electromechanical Systems
Authors: Cagan Berkay , Erdogan Metehan , Karakaya Ishak , Yilmaz Cemil , Yurdakul Burak
Published: July 2020

Electromechanical systems, which provide electrical power and data connection between moving terminals require high conduction and erosion resistant surfaces. Transfers of electrical power and data are accomplished by the contact of drum and brush wires. The simultaneous electrochemical deposition of desired Au-Ag-Cu alloy compositions, which can be used to coat the brush wires, was investigated in this study. In the scope of the study, the static potential and cyclic voltammetry behaviours of gold, silver and copper cyanide plating baths, as well as the mixtures of binary and ternary baths were investigated to obtain suitable amount of KCN and working potential values. SEM and EDS analyses were conducted in the characterization of coated samples.
Investigation of the Effect of Bath Ageing on Electropolishing Efficiency
Authors: Krishna Bivi , Wuthrich Rolf
Published: July 2020

The bath age poses a serious challenge while maintaining consistency in polishing qualities during prolonged electropolishing. It is a general practice in the industry to reuse the bath to cut down the cost and to minimise the harmful effects on the environment. The final polishing quality declines over time due to the increased dissolved metal ions. The present study presents the systematic data and a model to quantify the polishing bath status over prolonged electropolishing of stainless steel in an initial bath composed of 50% phosphoric acid, 35% sulphuric acid and remaining water. Variations in the properties of the bath (conductivity, specific gravity and viscosity) were measured and the variations in the quality of standard workpieces polished under identical conditions were determined at various bath ages. Further bath composition was determined periodically by titration.
Modeling Gas Diffusion Layers in Polymer Electrolyte Fuel Cells Using a Continuum-Based Pore-Network Formulation
Authors: García-Salaberri Pablo A. , Zenyuk Iryna V. , Gostick Jeff T. , Weber Adam Z.
Published: July 2020

Multiscale modeling of porous media in polymer electrolyte fuel cells is of paramount importance to improve predictions and assist the design of new materials. In this work, a composite-continuum-network formulation is presented to model species diffusion and convection in gas diffusion layers (GDLs). The model can be incorporated into CFD codes with moderate computational cost. The macroscopic model is based on a structured mesh composed of parallelepiped control volumes (CVs) and differential connectors (with negligible volume). The CV mesh embeds an internal structured pore network, which is used to determine analytically local anisotropic effective transport properties (effective diffusivity and permeability). The global structural parameters and effective transport properties predicted by the model are in good agreement with previous experimental data. Moreover, the results show that heterogeneities in the GDL can have significant influence on the fluxes from/to the catalyst layer, thus affecting local degradation rates.
Preparation of Unique Flower-like Pt-Ni Alloy Catalysts as the Cathode of a PEMFC by Electrodeposition Technique
Authors: Huang Jen-Hui , Yeh Tsung-Kuang , Wang Mei-Ya
Published: July 2020

The oxygen reduction reaction (ORR) at the cathode is the rate-determining step in a PEMFC. To enhance the ORR activity at the cathode, the unique flower-like platinum-nickel binary alloy catalysts were electrodeposited on the commercial carbon cloth by potentiostatic electrodeposition technique, the PtNi alloy effectively improved the oxygen absorption and desorption paths on the surface. The PtNi binary alloy catalysts with shorter lattice distance and effects of high-index facets would increase the electrochemical surface area (ECSA) of the catalysts and power density of the fuel cell. The samples of the pure platinum and commercial Pt/C catalyst were also prepared as comparison. Morphology, particle size and elemental composition are characterized by SEM, XRD and ICP-MS. In addition, the electrochemical characteristics of the PtNi catalysts were investigated via cyclic voltammetry (CV) and linear sweep voltammetry (LSV) analysis in 0.1 M perchloric acid solution with rotating disk electrode (RDE). In single cell test, the maximum peak power density of PEMFC with homemade PtNi alloy catalyst as the cathode reached 1031 mW/cm2, enhancing about 12% power density, compared to the commercial Pt/C.
Insights on the Lower Critical Solution Temperature Behavior of pNIPAM in an Applied Electric Field
Authors: LaFreniere Joelle , Roberge Emma , Ren Tianyu , Seitz William Rudolf , Balog Eva Rose M , Halpern Jeffrey M
Published: July 2020

Poly(N-isopropylacrylamide), or pNIPAM, is a free-radical polymer that is commonly studied for uses in surface coatings, tissue engineering, energy storage, biosensing, and more, due to its temperature responsiveness. pNIPAM is known to solubilize at temperatures below its lower critical solution temperature (LCST) and agglomerate above its LCST. This behavior has been shown to be reproducible and reversible. We confirmed this reversibility and the value of the LCST by performing dynamic light scattering (DLS) with a temperature sweep (increase and decrease). However, performing the same experiment under an applied voltage from copper electrodes, we observed a decrease in the LCST of pNIPAM and irreversible aggregation. Here we present preliminary data comparing the LCST behavior of pNIPAM in the presence of applied voltage using copper, aluminum, and carbon electrodes. We present data in support of the hypothesis that a phenomenon is occurring specifically with the use of copper electrodes that is altering pNIPAM LCST behavior.
Electrochemical Investigations of L-Cysteine Interactions with Bismuth Ions
Authors: Cheek Graham , Pena Dominik V
Published: July 2020

The interaction of L-cysteine with various bismuth compounds, namely, bismuth(III) salicylate, bismuth(III) citrate, and bismuth(III) nitrate, was studied at pH 1.0 (0.100 M HNO3 and 0.100 M HCl) and pH 7.4 MOPS buffer by cyclic voltammetry at glassy carbon and boron-doped diamond electrodes. Using details of the voltammetric behavior, it was determined that Bi3+ and L-cysteine (Cys) form a soluble complex at both pH 1.0 and pH 7.4. In addition, the reduction of the bismuth-cysteine complex to bismuth metal results in subsequent bismuth stripping. UV-VIS spectroscopy revealed that Bi3+ and L-Cysteine form a 1:2 Bi3+: Cys complex in pH 7.4 MOPS buffer.
Magnetic Filling of Microporous Silicon: An Interlink Between Optical and Magnetic Behavior
Authors: Granitzer Petra , Rumpf Klemens , Reissner Michael , Michor Herwig
Published: July 2020

In the frame of this work microporous silicon (mPSi) is filled with magnetic metals (Ni, Co) resulting in a composite system with specific magnetic properties corresponding to its branched morphology. The results are compared with mesoporous silicon (PSi) loaded with Ni nanoparticles (NPs) of comparable size. The two systems offer drastic differences in their magnetic response. Furthermore mPSi offers luminescence in the visible range, whereat this behavior is due to the small structure size in the range of a few nanometers (2 – 5 nm). The morphology of mesoporous silicon shows straight pores with a diameter up to 50 nm. Due to the different template morphology the responding magnetic behavior shows distinct properties related to the two systems, although the size of the metal deposits is in a similar size range. The Ni loaded mPSi system merges optical and magnetic properties leading to a nanocomposite appropriate for possible magneto-optical devices.
A Novel Method to Fabricate Hierarchical Copper Oxide Photoelectrode and Its Application for Photoelectrochemical Water Splitting
Authors: Hosseini H. Seyed Morteza , Siavash Moakhar Roozbeh , Soleimani Foad , Goudarzi Arghavan , Sadrnezhaad Sayed Khatiboleslam
Published: July 2020

In-situ deposition of cupric oxide (CuO) thin films on fluorine-doped tin oxide is performed through a rapid microwave–assisted method. The duration of microwave (MW) irradiation is optimized in order to prepare efficient and stable photocathodes for photoelectrochemical (PEC) water splitting. We obtain CuO with a unique morphology consisted of intermingled nanosheets. We evaluate PEC performance of the photocathodes through Linear Sweep Voltammetry (LSV) and current stability analyses. The highest achieved photocurrent density is -1.15 mA.cm-2 at 0 V vs. RHE for the sample MW-irradiated for 60 min. This value is comparable or superior to several other CuO-based photocathodes prepared by other chemical-based techniques. The improved properties is attributed to relatively high specific surface area, enhanced capability for light absorption on the photocathode surfaces, and more efficient transfer and/or separation of charge carriers. Hence, it offers our simple method as a promising technique for the preparation of low-cost, photostable photocathodes.
Hydrodynamic Studies of Ethanol Oxidation at Pt and PtRu Catalysts at Elevated Temperatures
Authors: Sayadi Azam , Pickup Peter G
Published: July 2020

Rotating disk voltammetry (RDV) has been applied to study the electrochemical oxidation of ethanol at Pt/C and PtRu/C electrodes at three different temperatures. Steady-state currents produced linear Koutecky–Levich (K-L) plots, in most cases, which provide estimates of the number of electrons transferred (stoichiometry). The PtRu/C catalyst showed better performances than Pt/C in terms of both activity and the number of electrons transferred at higher temperatures. Results showed that RDV can provide valuable stochiometric information for assessment of the completeness of ethanol oxidation.
Surface Design: Exploiting the Instability of Small Nanoparticles on Metallic Substrates
Authors: Awais Nashwa , Rodriguez Paramaconi , Albrecht Tim
Published: July 2020

Thiolated Au nanoparticles have been shown to undergo fast redistribution of the capping layer and subsequently of the metal core, when in contact with bare Au substrates. This is the result of an intricate interplay of entropic and enthalpic factors, which are likely affected by the choice of core metal and capping chemistry. This raises interesting questions, for example whether such a process could be used to modify and functionalize electrode substrates in a well-defined and controlled manner. Here, we report results for Pt and Au nanoparticles on Au and Pt substrates, based on the electrochemical response of the modified electrodes towards the oxidation of glycerol in alkaline media. Our study provides evidence that Pt nanoparticles on Au substrates remain relatively stable, while Au nanoparticles on Pt substrates readily decompose. This is in accordance with initial expectations based on the energetics of the thiol/metal bond.
Novel Radiation Device for Application in the UV-A and UV-B Range
Authors: Laube Michael , Herden Benjamin , Seelbach Egon , Braun Norbert , Berger Thomas , Jüstel Thomas
Published: July 2020

This work concerns an ultraviolet-A (UV-A) and UV-B emitting radiation unit. To this end, UV-A emitting light emitting diodes (LEDs) were combined with a Lu3Al5O12:Gd3+ (LuAG:Gd) coated Xe excimer discharge lamp. Prior to the application, the single-phase phosphor was optimized w.r.t particle size distribution and reflection spectrum before the photoluminescence properties were recorded. It turned out that LuAG:Gd is an intense emitting material in the UV-B spectral range. Afterwards, a phosphor paint was made and applied with an up-flush technique to a fused silica tube to create a uniform coating. For the excimer lamp a high voltage pulse generator in flyback topology was developed which allows to adjust the UV-B output from 1% to 100% without affecting the lamp efficiency. To maximize the UV output power the pulse width, pulse amplitude as well as the duty cycle of lamp was tuned. At last the complete set up was measured in front of an BaSO4 coated integrating sphere to record the radiation pattern and to show the scalability of the UV-A LEDs and UV-B excimer lamp. Overall, a fully adjustable and versatile radiation device for medical treatment, photochemistry and tanning purposes was engineered which could be an alternative to (coated) mercury discharge lamps and UV-B LEDs.
Review—Tetraruthenated Porphyrins and Composites as Catalysts and Sensor Materials: A Short Review
Authors: Gonçalves Josué M. , Matias Tiago A. , Angnes Lucio , Martins Paulo R. , Araki Koiti
Published: July 2020

Electrocatalytic and photocatalytic materials for energy and sensor applications are among the most relevant ones to overcome the challenges for a sustainable society. In this context, metalloporphyrins and transition metal complexes are known to exhibit interesting complimentary properties that can be combined to provide synergic effects, which was achieved in what so called tetraruthenated porphyrins and derivatives. The properties of these supramolecular species can be tuned based on the transition metal ion coordinated to the porphyrin, the ruthenium complex and especially the electronic coupling between those species conferring enhanced photoelectrochemical activity for conversion of carbon dioxide in valuable reduced species, or nitrite/nitrate to less harmful species. Another major application was shown to be as sensor materials for several substrates, generating more sensitive and robust devices. However, such a coordination chemistry strategy is evolving leading to new composite, polymeric and hybrids materials based on carbon nanomaterials, as well as 2D and 3D porous materials, opening new perspectives on supramolecular porphyrin chemistry powered by the versatile coordination chemistry of transition metal ions and clusters. This short review revisits the interesting spectroelectrochemistry and applications of tetraruthenated porphyrins, expanding to the most recent works pointing towards auspicious new outcomes in near future.
The influence of barosensory vessel mechanics on the vascular sympathetic baroreflex: insights into aging and blood pressure homeostasis
Authors: Lord Rachel N. , Wakeham Denis J. , Pugh Christopher J. A. , Simpson Lydia L. , Talbot Jack S. , Lodge Freya M. , Curry Bryony A. , Dawkins Tony G. , Shave Rob E. , Moore Jonathan P.
Published: July 2020

We assessed the influence of barosensory vessel mechanics (magnitude and rate of unloading and time spent unloaded) as a surrogate for baroreceptor unloading. In young men, aortic unloading mechanics are important in regulating the operating point of the vascular sympathetic baroreflex, whereas in middle-aged men, these arterial mechanics do not influence this operating point. The age-related increase in resting muscle sympathetic nerve activity does not appear to be driven by altered baroreceptor input from stiffer barosensory vessels.
Verification of the Nutritional and Dietary Factors Associated with Skeletal Muscle Index in Japanese Patients with Nonalcoholic Fatty Liver Disease
Authors: Himoto Takashi , Miyatake Keiko , Maeba Takashi , Masaki Tsutomu
Published: July 2020

We sought to identify the frequencies of presarcopenia, sarcopenia, and sarcopenic obesity in patients with nonalcoholic fatty liver disease (NAFLD) and to cross-sectionally determine the nutritional and dietary factors associated with loss of skeletal muscle mass in such patients. Dietary and body component changes produced by a diet intervention were longitudinally investigated. Forty-six NAFLD patients (24 males and 22 females) were enrolled. A second diet treatment was performed at 6 months after entry in 19 of the enrolled patients (6 males and 13 females). Body compositions and dietary nutrients at six months later were compared with those at entry. Three of the 24 (13%) males and four of the 22 (18%) females fulfilled the criteria for presarcopenia and one (5%) female NAFLD patient was in the criteria for sarcopenia at baseline. None of the patients were in the criteria for sarcopenic obesity. The factors associated with skeletal muscle index in the males were body mass index (BMI), insulin-like growth factor-1, total energy intake, and lipid intake, but only BMI and bone mineral density in females at baseline. The diet intervention decreased the skeletal muscle mass in the 6 males by decreasing the total energy intake via lower protein and lipid intakes and improved their liver dysfunction. In the 13 females, a decrease in total energy intake via lower carbohydrate and lipid intake did not change the skeletal muscle mass. These results suggest that loss of skeletal muscle mass is frequently observed in nonobese NAFLD patients and that the frequency of sarcopenic obesity seems to be rare in NAFLD patients. The nutritional and dietary factors that regulate loss of skeletal muscle mass were distinct between our male and female NAFLD patients. Thus, the skeletal muscle mass of such patients as well as their body weight and liver function should be monitored during diet interventions.
Global Well Posedness for the Thermally Radiative Magnetohydrodynamic Equations in 3D
Authors: Jiang Peng , Yu Fei
Published: July 2020

In this paper, we study the thermally radiative magnetohydrodynamic equations in 3D, which describe the dynamical behaviors of magnetized fluids that have nonignorable energy and momentum exchange with radiation under the nonlocal thermal equilibrium case. By using exquisite energy estimate, global existence and uniqueness of classical solutions to Cauchy problem in ℝ3 or T3 are established when initial data is a small perturbation of some given equilibrium. We can further prove that the rates of convergence of solution toward the equilibrium state are algebraic in ℝ3 and exponential in T3 under some additional conditions on initial data. The proof is based on the Fourier multiplier technique.