bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast and Selective CO2 Reduction into CO with Cobalt Phthalocyanine in a Flow Cell
Authors: Joulié Dorian , Ren Shaoxuan , Salvatore Danielle A. , Torbensen Kristian , Wang Min , Robert Marc , Berlinguette Curtis P. 
Published: May 2020

A balance between greenhouse gases production and capture is required to tackle the global warming resulting from them. Carbon dioxide (CO2) is considered as a waste gas but it is also a potential feedstock. Indeed, with the utilization of renewable energies, carbon dioxide electroreduction reaction (CO2RR) can generate useful products within a carbon neutral strategy. Practical CO2 conversion requires catalysts capable of mediating the efficient formation of a single product at high current densities over a long time (1). Among the potential products, carbon monoxide (CO) requires only 2 electrons to be generated which facilitate to reach high faradaic efficiencies. CO is also an important precursor in the chemical industry and its market is large enough to receive this new production method. (2)
High current densities have been hit with copper-based catalysts but these catalysts tend to be nonspecific to only one product. Solid-state catalysts struggle to maintain a relevant selectivity at low overpotentials. They also rely mostly on noble metals or use deposition methods that are not upscalable for an industrial use.
Molecular catalysts can be tuned to be highly selective towards CO at low overpotential but cannot operate CO2RR at relevant current densities for commercial purposes. Best molecular catalysts are close to 100 % faradaic efficiency for CO but the strongest production rate reported is 33 mA/cm² (3). This current density is more than 5 times smaller than the industrial relevant scale. Moreover, these catalysts are usually fragile over time with reported electrolysis less than ten hours.
In this presentation, we will show that Cobalt Phthalocyanine (CoPc) - a widely available and known molecular catalyst - is able to compete with solid-state catalysts. We will illustrate how the CO2 delivery to a gas diffusion electrode can increase the reactivity of a molecular catalyst. We succeed to operate CO2RR with 95% faradaic efficiency for CO at 150 mA/cm² and an overall cell potential of 2.45 V. (4) We will also emphasize how the tunability of such catalysts can lower the reaction overpotential and increase the stability. (5)
1: Ind. Eng. Chem. Res. 2018, 57, 2165−2177
2: Acc. Chem. Res. 2018, 51, 4, 910-918
3: ACS Energy Lett. 2018, 3, 10, 2527-2532
4: Science 2019, 365, 6451, 367–369
5: Nature comm. 2019, 10, 3602
The Effect of Prolyl Hydroxylase Domain-Containing Protein Inhibitors on Porphyrin Accumulation in Cancer Cells
Authors: Matsui Hirofumi , Kurokawa Hiromi , Matano Daisuke 
Published: May 2020

Introduction: The authors found that reactive oxygen species (ROS) accelerate both the cancer cellular porphyrin accumulation and the effect of photodynamic therapy. We confirmed that EPO/ EPO receptor was a key of signal transduction. EPO has been known used to be up-regulated at the metabolic acidosis via the stabilization of HIF-1α, a nuclear factor. Since HIF-1α can be stabilized by not only acidosis but also the high concentration of nitric oxide (NO), NO rich cancer cells may involve EPOR. Moreover, the purpose of EPO-EPOR system is likely to survive the hypoxic condition, it may keep intracellular heme/ porphyrins. Recently, prolyl hydroxylase domain-containing protein inhibitors (PHDI) are gathering attention as drugs for anemia. Since these drugs continuously stabilize HIF1, EPO-EPOR system in cancer cells may be activated. Thereby, cancer specific porphyrin accumulation should be accelerated.
Methods: To prove these possibilities, the authors carry out following experiments with gastric and colorectal cancer cells. The existence of EPOR, the amount of ABC transporters (B1, C5, G2) after the PHDI exposure (dose dependency and time dependency) were analyzed by western blotting. Cytotoxicity of both PDT and anti-cancer drugs with or without rEPO was measured with the Cell Counting Kit-8.
Result: (1) EPOR existed in each cell line used in this study. (2) PHDI treatment involved down regulation of ABC transporters (B1, C5, G2) in dose dependently. (3) ABCG2 expression decreased after PHDI treatment. However, its expression re-increased 48 hours after treatment. (4) The pretreatment of PHDI significantly increased the effect of PDT, doxorubicin, paclitaxel, irrinotecan, cisplatin, 5-FU and oxaliplatin even in chemo-resistant cells.
Conclusions: PHDI accelerates the effect of PDT and anti-cancer drugs.
(Keynote) Engineering Research Centers –Past, Present and Future
Authors: Wang Kon-Well 
Published: May 2020

During the recent decades, the scientific and engineering community and the federal agencies have explored the potential of large-scale center-type research programs. It has been recognized that many of the most challenging and complex technical problems can only be addressed if researchers with diverse expertise combine their efforts and work across the boundaries between disciplines. The National Science Foundation (NSF) Engineering Research Center (ERC) program is a flagship program in this regard.
The ERCs are interdisciplinary, multi-institutional centers that join academia, industry, and government in partnership to produce transformational engineered systems and educate individuals that are adept at innovation and primed for leadership in the global economy. They operate at the interface between the discovery-driven culture of science and the innovation-driven culture of engineering. Since the ERC program’s inception in 1984, NSF has funded over 70 ERCs across the United States. The NSF funding level has been at about $4 million per year for each ERC for up to 10 years, during which time the centers would develop partnerships with industry, universities, and other government entities to sustain them upon graduation from NSF support. Throughout the years, the ERCs have contributed significantly to the technical community and the nation; educated more than 12,000 engineering graduates with interdisciplinary training, produced a tremendous amount of high impact publications, patents and licenses, and spin-off companies. Studies have estimated that the total downstream market value of ERC innovations to the U.S. economy is well over tens of billions of dollars. Recently, NSF funded the National Academies of Sciences, Engineering, and Medicine (NASEM) to conduct a study to create a vision for future research centers in engineering (A New Vision for Center-Based Engineering Research, 2017, The National Academies Press). Building upon the NASEM’s recommendations, NSF developed a roadmap for the next generation of ERCs (Gen-4), which emphasizes cutting-edge research efforts that are convergent and will lead to strong societal impact. A Gen-4 ERC will have interacting foundational components that cover convergent research, workforce development, culture of diversity and inclusion, and innovation ecosystem. This presentation will provide an overview of the NSF ERC program to date, as well as new opportunities for the Gen-4 ERCs.
Synthesis and Characterization of Cellulose Acetate- Titanium (IV) Tungstomolybdate Nanocomposite Cation Exchangers for the Removal of Selected Heavy Metals from Aqueous Solution
Authors: Woldegebriel Belay Minase 
Published: May 2020

Novel Cellulose acetate titanium (IV) tungstomolybdate nanocomposite cation exchanger was synthesized by sol-gel method by incorporating cellulose acetate polymer into inorganic exchanger, titanium (IV) tungstomolybdate. Different techniques including FTIR, XRD, TGA SEM and BET were used to characterize the exchanger. The Cellulose acetate titanium (IV) tungstomolybdate (CATTM) behaved as a good cation exchanger with IEC of 1.64 meq g-1 for Na+ ions. The sequence of ion exchange capacity for alkali metal ions was found to be K+> Na+> Li+ and that for alkaline earth metal ions was Ba2+ > Ca2+ >Mg2+ .These orders revealed that the ions with smaller hydrated radii acquired larger ion exchange capacity. The pH titration curve indicated that the material obtained as such is a bi functional strong cation exchanger as indicated by a low pH (~2.25) of the solution when no OH- ion was added. Thermal analysis of the material showed that the material retained 55% of its ion exchange capacity up to 600°C. Adsorption behavior of metal ions in different solvents with varying concentration has also been explored and the sorption studies revealed that the material was selective for Cr(III) and Pb(II) ions. The analytical utility of the material was investigated by performing binary separations of selected metal ions in a column based on the distribution coefficients of the metals. Cr(III) and Pb(II) were selectively removed from synthetic mixtures of Cr(III)-Cd(II), Cr(III)-Fe(III), Pb(II)-Cd(II) and Pb(II)-Fe(III). Antimicrobial activity of the synthesized inorganic compound was evaluated and showed a considerable antibacterial activity against Staphylococcus aureus, Streptococcus agalactiae, Escherichia coli and Shigella flexneri. The inorganic counterpart has also exhibited a promising antifungal activity against Aspagilus niger and Fusarium oxysporim.
Key Words; Binary separations, Cellulose acetate, Characterization, Nanocomposite, Sol-gel method.
A Study of the Electrical Properties of the Polydopamine Coating of CNTs: A New Path to Fabricate Copper-Carbon Composites
Authors: Duhain Antoine , Lamblin Guillaume , Lenoble Damien 
Published: May 2020

In present days, the continuous miniaturization of electronic devices comes along with a problematic reduction of their life-time. This is due to the underlying current density being operated increasingly close to the maximum current-carrying capacity (ampacity) of the materials (copper, gold...) used in the conduction channels of micro-circuitry. In this respect, there is a growing attention for new materials with higher ampacity and copper-carbon nanotube (CNT) composites could constitute a promising alternative. The interest of such copper-carbon composites relies on the combination of the complementary properties of both materials: the high conductivity of copper and the high ampacity of CNTs.
However, the fabrication of an efficient Cu-CNT composite still remains a huge challenge and, up to now, the metal filling of a CNT matrix using electrochemical methods systematically requires an organic solvent based solution, which is not industrially and ecologically friendly. This constitutes an important drawback of those types of fabrication paths.
A new promising way to fabricate such a composite by electrochemistry is shown in our work (see figure 1). It is based on the coating of CNTs by polydopamine (pda) cross-linked with copper ions. The coated CNTs are sprayed to form a matrix and the interstices are then filled with metallic copper by using an electrochemical step in aqueous solution.
It is relevant to study how pda impacts the CNT surface conductivity and to try to increase it in order to promote electron transfer through the copper-CNT interface. In this respect, we want to evaluate the conductivity of CNT surface by using AFM probing. To assess the impact of pda, we compare conductivity values of uncoated CNTs with coated CNTs. We also show the change in conductivity when the coated CNTs are annealed at different temperatures under inert atmosphere conditions. To better understand the electrical properties, we characterize the CNT coatings before and after thermal treatment with FTIR, STEM, XPS, and DSC, which in particular shows the transformation of the pda layer and the formation of well-dispersed nuclei on the CNT surface.

Figure 1
Analysis on Temperature Dependent Corrosion of Tantalum in Acidic Fluoride Media
Authors: Punathil Meethal Ranjith , Srinivasan Ramanathan 
Published: May 2020

Tantalum (Ta) exhibits excellent corrosion resistance in most aqueous media as it forms chemically inert thin oxide layer when exposed to air or water. Due to the high corrosion resistance, Ta is used in chemical industries as lining material for piping, tanks and vessels (1). Although Ta possess excellent corrosion resistance, it dissolve very slowly in acidic fluoride media. In the present work, the corrosion rate of Ta in acidic fluoride media at different temperatures were measured from weight loss experiment and compare with the results of electrochemical Tafel extrapolation.
The weight loss experiments were performed with Ta sheets of 2.5 × 2.5 cm with 1 mm thickness. Prior to the experiments, Ta sheets were polished with 0.3 µm alumina powder and cleaned by ultrasonicated in ethanol, rinsed in deionized water and dried with nitrogen gas. The temperature of the HF solution was maintained using a water bath and double-walled polypropylene beaker set up. The weight loss experiments were performed in various concentration of HF from 250 to 1000 mM HF and the experiments were also conducted by adding 250 mM KF/ H2SO4 into 500 mM HF solution to study the key HF dissociated species responsible for the corrosion of metal. The weight loss was measured at different temperature of the solution varied from 30 to 60 °C for any concentration of HF solution. In most of the experiments, the weight difference before and after the experiments were used to calculate the dissolution rate. A few experiments were also conducted wherein the weight was continuously monitored, so that the dissolution rate can be monitored as a function of time.
The experimental dissolution rates of Ta in various concentrations of HF at different temperatures are shown in Fig. 1. An analysis of the results shows that corrosion of Ta is assisted by both undissociated HF and species. The activation energy of the reactions were estimated using Arrhenius expression, and the results show that Ta corrosion in acidic fluoride media is very sensitive to temperature and will proceed at rapid rates at high temperatures.
The corrosion of Ta in acidic fluoride media at room temperature was also characterized using several electrochemical techniques, viz. Tafel extrapolation, electrochemical impedance spectroscopy and linear polarization. A comparison of the results of weight loss experiments show that Tafel extrapolation over predicts the corrosion rate, in most of the conditions. The EIS spectra obtained at OCP shows multiple loos (capacitive and inductive) in most of the concentrations and equivalent circuit analysis was used to estimate the R
P value. The XPS analysis was also performed to understand the different metal oxide species present during the corrosion process. The results indicates that the dissolution process of Ta occurs viz. multiple intermediate steps.

References

1. K. Schulz and J. Papp, Niobium and tantalum: indispensable twins, in, US Geological Survey (2014).

Figure 1
Modeling the Effect of Fast Charge Protocol on the Temperature Rise of a Lithium-Ion Battery during Charge
Authors: Lee Jaewoo , Koo Boram , Shin Chee Burm 
Published: May 2020

The lithium-ion battery (LIB) is a preferred power source for battery electric vehicles (BEVs),because LIBs have higher energy density, longer life and higher power density than most other practical batteries. Although there is still a plenty of room to be improved for the cost, life, and safety of the LIB in BEV applications,another important issue to be overcome for the BEV battery is searching for an appropriate fast charge protocol to enable a rapid growth of BEV market. A short charge time, however, results in a rapid temperature rise of an LIB cell during charge. Therefore, it is essential to find an optimized fast charge protocol that can keep the peak temperature of LIB cell below the maximum allowable limit recommended by the LIB manufacturer.
In this work, the effect of fast charge protocol on the temperature rise of an LIB cell during charge is analyzed based on the two-dimensional thermal modeling of the LIB cell under various fast charge protocols. The thermal modeling during fast charge is validated by the comparison of the modelling results with the experimental measurements using IR thermal images and thermocouples. The fast charge protocols are evaluated based on the peak temperatures of the LIB cell after charge.
Relationship between Metallurgical States and Corrosion Resistance of Nitrided Martensitic Steels in Marine Environment
Authors: Creus Juan , Reilhac Pierre , Michel Gregory , Branger Vincent , Frappart Simon , Fleche Denis , Trinh Dao , Feaugas Xavier 
Published: May 2020

The objective is focused on the comprehension of the relationship between the metallurgical state and the functional properties of nitrided martensitic stainless steels.
Nitriding is performed by a low temperature plasma treatment (Direct Current mode) in various conditions. Metallurgy of the nitrided layer was characterized at different scales, from the macroscopic to the nanometric ones. An increase of the thickness of the nitrided layer with temperature of the plasma treatment is observed. Precipitation of CrN and others nitrided phases in relation with crystallographic defects is observed. Moreover, the TEM analyses on FIB samples extracted from the surface highlight the formation of a succession of different nitrided layers depending on the nitrogen content : expanded martensite, iron-nitride phases [2].
The electrochemical properties of nitrided samples are also assessed by voltammetry test and extended immersion test. Results highlight differences on the corrosion behaviour of the nitrided X17CrNi16-2 steels with temperature of the plasma treatment. The reactivity evolution is linked to the formation of a “composite” system composed of different layers. SECM was used to understand the reactivity evolution through these layers, and successive surface grinding permits to corroborate the reactivity evolution and to understand the origin of the corrosion resistance evolution after nitriding process.

[1] H.E. Boyer, T.L. Gall. Metal Handbook, Desk edition, ASM, Ohio, USA, 1986
[2] J. Yang &al. Materials and Design, Vol. 32 (2011) 808-814
Corrosion Rate Investigation of Magnesium and Some of Its Alloys in 0.9% NaCl Solution
Authors: Ostapenko Gennady I. 
Published: May 2020

Magnesium(Mg)-based biomaterials are candidates for use as biodegradable metals. Mg can dissolve in body fluids, which means that implanted Mg can decompose during the healing process and it will not leave debris after healing is completed. However, uncontrolled degradation can destroy the scaffolds, leading to premature failure of the implant. The rate of magnesium degradation can be controlled by various impurities.
Here, the corrosion of Mg and some of its alloys is investigated by electrochemical impedance and voltammetry methods. In the Figure, for example, the voltammogram (a) and impedance hodograph (b) are shown for an alloy containing 6.0 mass % Zn and 0.5 mass % Zr. In the Table, the corrosion rates are given from impedance measurements as the closest to stationary corrosion conditions.
The corrosion rate is determined by the chemical composition and structure of the oxidation product layer. The shift of the corrosion potential in the anodic direction after cathodic polarization is explained by kinetic difficulties of electrode reactions in the presence of the reaction product layer.

Figure 1
Assessing the Corrosion Pattern of Magnesium Alloy Implants in Simulated Salivary Fluids at Different pH
Authors: Eduok Ubong 
Published: May 2020

Magnesium (Mg) alloy implants are formidable structural metals for biomedical applications, they are limited due to Mg chemical reactivity and its susceptible to corrosion. Efficient mitigation control toward Mg corrosion can only be proposed if its degradation kinetics are properly understood in various media. In the biomedical field, the auto-controlled degradation mechanism of orthopedic Mg implants eliminates repeated surgeries while also minimizing the risks associated with these medical procedures. However, their rapid degradation kinetics between living tissues contribute to sudden changes in local pH value, accumulation of unwanted hydrogen gas in bone cavities and subsequent mechanical failure. In this work, we have investigated the degradation pattern of Mg alloy implant in chloride-enriched simulated salivary fluids at different pH at room temperature. The implant demonstrated varying rates of corrosion and passivation within a range of pH of corrosion media. The effects of solution treatment on implant corrosion behavior was vividly studied and the trend of increasing corrosion was low pH > saline pH > high pH. Localized corrosion behavior has been observed by scanning electron microscopy evidence while electrochemical impedance spectroscopy and potentiodynamic polarization techniques revealed increased anodic polarization and charge transfer, respectively. The chemistry and diffraction phases of adhering corrosion products as well as their surface morphologies was also been identified. The implant must have uniformly corroded within the salivary fluids over an extended duration; however, the early corrosion stages reveal localized passivation of oxide films at grain boundaries at low pH.
Most metallic implants made of corrosion-resistant alloys (e.g., cobalt, titanium and nickel) are excellent candidates for oral surgeries. However, most of them cannot serve as bone cements to stabilize dental implants during post-surgery tissue healing; a function that is possible with magnesium-based bone cement [1,2]. The use of these metal-type temporary implants in binding bone structures normally will require a secondary surgery operation to remove them, and this might lead to potential infections. This study features the analyses of the corrosion patterns of Mg alloy implants deployed in orthopedic applications. The salivary pH changes induce corrosion toward septic loosening prior to Mg implant degradation and dental implant infections.

References

[1] A. Mohamed, A.M. El-Aziz, H.G. Breitinger, Journal of Magnesium and Alloys, 7, 249 (2019).
[2] B.M. Sehlke, T.G. Wilson, A.A. Jones, M. Yamashita, D.L. Cochran, Journal of the Academy of Osseointegration, 28, 357 (2013).