Current Values Research Articles

Study of the LaNi3.55Mn0.4Al0.3Co0.75 hydrogen storage anode /KOH interface by electrochemical impedance spectroscopy (EIS) during a galvanostatic cycling

This study aimed to evaluate the electrochemical performance of a compound through electrochemical impedance spectroscopy technique. The findings presented in this work unequivocally establish the interdependency between cycling and all the investigated electrochemical parameters. Remarkably, we noted a noticeable decrease in absorption resistance during the initial cycles, as evidenced by the reduction in Rct values from 1.3 Ω.cm2 (uncycled electrode) to 0.9 Ω.cm2 (3rd cycle), indicating an improvement in the activation properties of the electrode. However, the first charge/discharge cycles showed a decrease in double-layer capacity and absorption capacity. Furthermore, we observed a surge in exchange current value from 19 mA.cm−2 to 28 mA.cm−2 during the second cycle, followed by a gradual decline towards a range of 22.5 mA.cm−2 at the 10th cycle. The hydrogen coefficient also underwent significant changes during cycling, increasing initially and reaching a maximum value of around 1.77 × 10−11 cm2.s−1 at the 5th cycle.

Benefits evaluation of ecological restoration projects based on value realization of ecological products

Ecological restoration project is the premise to realize the value of ecological products. The current ecological product value accounting and ecological restoration project benefit evaluation methods are interlinked. The benefit evaluation of ecological restoration projects can not only analyze the completion of ecological restoration projects, but also quantify the impact of externalities on regional development. This study proposes a hypothesis that the benefit evaluation results of ecological restoration projects can affect the realization of urban ecological product value. In order to verify the above hypothesis, this study designed a benefit evaluation framework to evaluate the economic benefits, ecological benefits and project costs of ecological restoration projects. In this study, the benefit evaluation results are divided into three cases to calculate the benefit-cost ratio under different conditions. The three cases are only considering the direct economic benefits (DEB), considering the indirect economic benefits (TEB) and considering the comprehensive benefits (AEB). Taking Jiangyin City of Jiangsu Province as an example, the benefit evaluation of water source protection project in Jiangyin City is carried out. The results show that the benefit-cost ratios in the three cases are 6.68,7.60 and 9.36, respectively. The results show that the benefit-cost ratio is different in different benefit situations. Therefore, when discussing the realization path of ecological product value in ecological restoration areas, it is also necessary to discuss the situation. The evaluation system can provide reference for the benefit evaluation of ecological restoration projects, and also provide data and theoretical support for the realization of regional ecological product value.

Examining the Progression of Blockchain Technology and Its Implementation During Digital Economy

Blockchain technology is a peer-to-peer, distributed, and innovative database and disruptive information technology. It has features such as decentralized organization, tamper resistance, and anonymity. It has become the most critical element in developing a new generation of information infrastructure in China and a core component in driving the digital economy. Blockchain relies on the Internet ecosystem, providing not only the foundation for trusted protocols but also unlimited potential applications in inclusive financial services, digital assets, e-government, and other fields. It integrates the most advanced information technologies in modern society, making it of great significance in reshaping and developing the digital economy. This article explores the characteristics and development history of blockchain technology, as well as its current research status and potential theoretical value and practical significance when applied to digital economic scenarios. At the same time, it will discuss the current limitations of blockchain research, possible future directions, and development methods.

The Application of COBIT Framework to Evaluate Information System Governance in National Business Technology Transformation Companies

The purpose of this study is to determine how to assess information technology governance by utilizing the COBIT 5 framework and the domains of APO01 (Manage the IT Management Framework), EDM04 (Ensure Resource Optimization), and APO04 (Manage Innovation). The COBIT 5 architecture is employed in this study. Both qualitative and quantitative research methodologies were used in this study. Through surveys, interviews, and observations, we gathered primary data. The secondary data came from various existing sources, including websites, literature reviews, and the findings of other investigations. This study's information technology governance data analysis approach complies with COBIT 5's Assessment Process Activities. According to the analysis, the current state's capability value in the EDM04 domain is 1.8. In the meantime, the capability value is 2.9 for the anticipated circumstance. The APO01 domain's recent state results in a capability value of 1.7. In the meantime, the capability value is 3.1 for the expected circumstance. In the APO04 domain, the current state has a capability value 1.6. Under ideal circumstances, the business receives a capacity value of 3. This implies that the business needs to fulfill the prerequisites for level 2 process capacity indicators, which are now unfulfilled. For instance, producing papers outlining the management of the innovation process and documents evaluating rejected innovative ideas.

Application of Under-Impedance Criterion to Protect against Effects of Phase-to-Phase Short Circuits in Medium-Voltage Networks

Common overcurrent criteria used to detect phase-to-phase short circuits in medium-voltage (MV) networks in some cases do not bring the expected results. In particular, this applies to instantaneous overcurrent protections in lines with variable ranges and lines leading to local power plants (LPP), which generate a short-circuit current slightly greater than the rated current. When using overcurrent protections, there are some problems with ensuring the appropriate sensitivity and selectivity. This article proposes a protection based on impedance measurement against the effects of phase-to-phase short circuits in MV lines. The protection can be used at switchgears and also at protection points (PP) located deep in the network. The under-impedance criterion has a range independent of the value of the short-circuit current, and it can be alternative or complement to classic overcurrent protection. The introduction of these criteria allows the protection range to be independent of the type of short circuit and the short-circuit power on the busbar, and to determine this range more precisely. The under-impedance protection is particularly useful in conditions of a growing number of energy sources deep inside the networks and its automation. The main idea was to develop a uncomplicated characteristic that would ensure the possibility of setting the under-impedance protection by people who are not specialists in the field of distance protections. The characteristics have been optimally developed both in terms of the area of detected impedances and easy implementation, operation, and configuration.

A Robust Zero-Watermarking Scheme in Spatial Domain by Achieving Features Similar to Frequency Domain

In recent years, there has been a substantial surge in the application of image watermarking, which has evolved into an essential tool for identifying multimedia material, ensuring security, and protecting copyright. Singular value decomposition (SVD) and discrete cosine transform (DCT) are widely utilized in digital image watermarking despite the considerable computational burden they involve. By combining block-based direct current (DC) values with matrix norm, this research article presents a novel, robust zero-watermarking approach. It generates a zero-watermark without attempting to modify the contents of the image. The image is partitioned into non-overlapping blocks, and DC values are computed without applying DCT. This sub-image is further partitioned into non-overlapping blocks, and the maximum singular value of each block is calculated by matrix norm instead of SVD to obtain the binary feature matrix. A piecewise linear chaotic map encryption technique is utilized to improve the security of the watermark image. After that, the feature image is created via XOR procedure between the encrypted watermark image and the binary feature matrix. The proposed scheme is tested using a variety of distortion attacks including noise, filter, geometric, and compression attacks. It is also compared with the other relevant image watermarking methods and outperformed them in most cases.

Toxicity of herbicides to the marine microalgae Tisochrysis lutea and Tetraselmis sp.

Pesticides are ubiquitous in the catchments of the Great Barrier Reef (GBR) and regularly discharge into the nearshore waters. Effective management of pesticides requires suitable water quality guideline values (WQGVs), and further ecotoxicological data for many pesticides are needed to improve the reliability of environmental risk assessments. To help address this issue, toxicity thresholds were determined to two species of tropical marine microalgae Tisochrysis lutea and Tetraselmis sp. for a suite of herbicides detected in the GBR. Photosystem II (PSII) herbicides significantly reduced growth with no effect concentration (NEC) and 10% effect concentration (EC10) values spanning two orders of magnitude from 0.60 µg L−1 for diuron to 60 µg L−1 for simazine across both species. However, growth was insensitive to the non-PSII herbicides. The NEC/EC10 thresholds for most herbicide-microalgae combinations were greater than recent WQGVs intended to protect 99% of species (PC99); however, metribuzin was toxic to T. lutea at concentrations lower than the current PC99 value, which may have to be revisited. The toxicity thresholds for alternative herbicides derived here further inform the development of national and GBR-specific WQGVs, but more toxicity data is needed to develop WQGVs for the > 50 additional pesticides detected in catchments of the GBR.

Identification of Cu(111) as Superior Active Sites for Electrocatalytic NO Reduction to NH3 with High Single‐Pass Conversion Efficiency

AbstractOpting for NO as an N source in electrocatalytic NH3 synthesis presents an intriguing approach to tackle energy and environmental challenges. However, blindly pursuing high NH3 synthesis rates and Faradaic efficiency (FE) while ignoring the NO conversion ratio could result in environmental problems. Herein, Cu nanosheets with exposed (111) surface is fabricated and exhibit a NO‐to‐NH3 yield rate of 371.89 μmol cm−2 h−1 (flow cell) and the highest FE of 93.19±1.99 % (H‐type cell). The NO conversion ratio is increased to the current highest value of 63.74 % combined with the development of the flow cell. Additionally, Crystal Orbital Hamilton Population (COHP) clearly reveals that the “σ‐π* acceptance‐donation” is the essence of the interaction between the Cu and NO as also supported by operando attenuated total reflection infrared spectroscopy (ATR‐IRAS) in observing the key intermediate of NO−. This work not only achieves a milestone NO conversion ratio for electrocatalytic NO‐to‐NH3, but also proposes a new descriptor that utilizes orbital hybridization between molecules and metal centers to accurately identify the real active sites of catalysts.

Identification of Cu(111) as Superior Active Sites for Electrocatalytic NO Reduction to NH3 with High Single-Pass Conversion Efficiency.

Opting for NO as an N source in electrocatalytic NH3 synthesis presents an intriguing approach to tackle energy and environmental challenges. However, blindly pursuing high NH3 synthesis rates and Faradaic efficiency (FE) while ignoring the NO conversion ratio could result in environmental problems. Herein, Cu nanosheets with exposed (111) surface is fabricated and exhibit a NO-to-NH3 yield rate of 371.89 μmol cm-2 h-1 (flow cell) and the highest FE of 93.19±1.99 % (H-type cell). The NO conversion ratio is increased to the current highest value of 63.74 % combined with the development of the flow cell. Additionally, Crystal Orbital Hamilton Population (COHP) clearly reveals that the "σ-π* acceptance-donation" is the essence of the interaction between the Cu and NO as also supported by operando attenuated total reflection infrared spectroscopy (ATR-IRAS) in observing the key intermediate of NO- . This work not only achieves a milestone NO conversion ratio for electrocatalytic NO-to-NH3 , but also proposes a new descriptor that utilizes orbital hybridization between molecules and metal centers to accurately identify the real active sites of catalysts.

A novel electrochemical sensor for the detection of metronidazole in honey using the g-C3N4/MnO2/ZnO modified electrode

During beekeeping, the utilization of metronidazole (MNZ) for treating bee ailments leads to the MNZ residues in honey. Prolonged ingestion of honey with MNZ residues could pose potential health hazards to humans. Therefore, the development of a straightforward and efficient MNZ detection method is of utmost importance. ZnO, a non-toxic catalytic material, exhibits promising potential in electrochemical sensor design. The resulting g-C3N4/MnO2/ZnO composite was employed to craft an electrochemical sensor that facilitates swift MNZ quantification in honey. Comprehensive characterization of the synthesized composites was performed, and the electrochemical behavior of MNZ was explored using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It was found that the g-C3N4/MnO2/ZnO composite exhibits remarkable electrocatalytic capability, and the resulted sensor demonstrates good sensitivity. Within a range of 2–250 μM, MNZ's current value showed two linear relationships with its concentration, achieving the detection limit of 0.21 μM. When applied to honey samples, the g-C3N4/MnO2/ZnO/GCE sensor detected MNZ with recovery rates spanning 93.7% to 100.3% and relative standard deviations (RSD) under 3%. This attributed to heightened sensitivity, selectivity, repeatability and durability of the sensor. Furthermore, its effectiveness extends to the rapid assessment of MNZ content in actual honey, highlighting its practical utility in identifying MNZ residues in honey.

Thermodynamic-assisted highly effective target converting strategy for sensitive electrochemical detection of trace lead (II) ion

In the present work, a thermodynamic-assisted target-converting strategy was designed by utilizing new 2D DNA nanoprobes (DNPs) to develop electrochemical biosensors for the sensitive determination of trace Pb2+. Herein, a stable DNP with a special structure was prepared through the hybridization reaction between three single-strand DNA (RS1, RS2, and P). Once the existence of Pb2+, the DNP will crumble and then release RS1 and RS2 due to the strong thermodynamic instability of the RS1/RS2 duplex. since RS1 and RS2 were designed in the same sequence in the free domain, they can be simultaneously used as effective output DNA, enhancing the conversion rate of Pb2+to ssDNA up to 1:2. Following the same principle, ferrocene-labeled bipedal DNPs (Fc-bDNPs) are prepared for stable electrochemical signal output. In the presence of RS1, RS2, and a hairpin DNA strand (H1), the ferrocene-labeled DNA strands (S3) escape from the Fc-bDNPs due to strand-displacement reaction, accompanying release of the two ssDNA outputs that can simultaneously trigger another strand-displacement reaction. Consequently, the one Pb2+input makes multiple Fc-labeled DNA strands far away from the electrode surface, resulting in a dramatic decrease in the response current of Fc. The developed biosensors show a linear relationship between current value and logarithmic concentration of Pb2+ ranging from 1 pM to 40 nM with a detection limit of 0.30 pM.

Hybrid battery energy storage for light electric vehicle — From lab to real life operation tests

The aim of the research presented in the paper is to improve the lifetime of lead-acid battery systems which are widely used in low-speed electric vehicles or utility vehicles, since the cycle life of lead-acid batteries is nonlinearly dependent on the depth of discharge and electrolyte temperature. The solution proposed here is to connect lead-acid batteries with a small lithium‑iron-phosphate battery using only a diode. This connection is simple and does not require the use of an actively controlled converter. The concept was tested at various levels of an experiment, from the initial calculation of cycle life improvement and simulation, through a laboratory experiment, all the way to operational environment tests. The results obtained confirmed the main assumptions of the study: decrease in the depth of discharge of lead-acid battery for the distance traveled of around 17 %—which would translate into a 30 % better cycle life according to the characteristics indicated by the producers—and decrease in the root mean square and maximum current values of lead-acid battery by around 40–50 % and 26 %, respectively. Range extension was also achieved in vehicles. The solution has been successfully introduced to the market and is now used in few light electric vehicles.

A new set of Lean indicators to assess Greenhouse Gas emissions related to industrial losses

PurposeThis paper presents a new and well-structured framework that aims to assess the current environmental impact from a Greenhouse Gas (GHG) emissions perspective. This tool includes a new set of Lean Key Performance Indicators (KPIs), which translates the well-known logic of Overall Equipment Effectiveness in the field of GHG emissions, that can progressively detect industrial losses that cause GHG emissions and support decision-making for implementing improvements.Design/methodology/approachThe new metrics are presented with reference to two different perspectives: (1) to highlight the deviation of the current value of emissions from the target; (2) to adopt a diagnostic orientation not only to provide an assessment of current performance but also to search for the main causes of inefficiencies and to direct improvement implementations.FindingsThe proposed framework was applied to a major company operating in the plywood production sector. It identified emission-related losses at each stage of the production process, providing an overall performance evaluation of 53.1%. The industrial application shows how the indicators work in practice, and the framework as a whole, to assess GHG emissions related to industrial losses and to proper address improvement actions.Originality/valueThis paper scrutinizes a new set of Lean KPIs to assess the industrial losses causing GHG emissions and identifies some significant drawbacks. Then it proposes a new structure of losses and KPIs that not only quantify efficiency but also allow to identify viable countermeasures.

Combating ageism in medical education with narrative medicine

ABSTRACT Ageism is common in medical trainees and difficult to overcome. The My Life, My Story program has been shown to be an effective tool for increasing empathy. We explored its use as an instrument for combating ageism by implementing it in a Geriatrics clerkship for fourth year medical students. During our evaluation, 151 students interviewed patients about their lives using a semi-structured question guide. Students completed the UCLA Geriatrics Attitudes Scale and the Expectations Regarding Aging Survey pre-and post-clerkship. We also facilitated 9 student debriefs and 5 faculty interviews. After completing My Life, My Story, students were more likely to disagree with “I would rather see younger patients than elderly ones” and “it’s normal to be depressed when you are old”. In qualitative analysis of the debriefs, we identified a key summative theme: “impact of the intervention on care teams”. Within that, we describe three subthemes: an awareness of richness of the lives led by older people, their current value to society, and the social determinants of health they have faced. After participating in My Life, My Story, students’ attitudes toward aging changed. A narrative medicine program using life stories can be a practical tool for addressing ageist stereotypes.

ANALISA PENGARUH ARUS LISTRIK PENGELASAN GMAW ALUMUNIUM 5052

Aluminum (Al) is a light metal that has corrosion resistance and good electrical conductivity. It is estimated that the use of aluminum in the future will still be wide open, both as a main material and as a supporting material, with the abundant availability of aluminum ore on earth. The welding process is one part of the manufacturing process. The welding process, which in principle is to connect two or more components, is more precisely indicated for assembling several components into a machine form. Welding Aluminum 5052 using GMAW welding with variations in welding electric current, namely 200A and 210 A, welding using the E4043 electrode. The aim of this research is to determine the strength of GMAW welded joints on Aluminum 5052 against the Charphy impact test. The GMAW welding electric current value at an electric current of 200 A produces a work force of 55.012 J and produces 0.678 J/????????2 impact charphy value, at an electric current of 210 A it produces a work force of 64.34 J and produces 0.804 J/????????2 impact charphy value. From the calculation results that have been obtained, the higher the GMAW welding electric current used causes the weld area to become more ductile, but on the contrary, the lower the GMAW welding electric current, the harder it is and tends to break easily.

Effects of Direct and Pulse Plating on the Co-Deposition of Sn-Ni/TiO2 Composite Coatings.

Sn-Ni alloy matrix coatings co-deposited with TiO2 nanoparticles (Evonik P25) were produced utilizing direct (DC) and pulse electrodeposition (PC) from a tin-nickel chloride-fluoride electrolyte with a loading of TiO2 nanoparticles equal to 20 g/L. The structural and morphological characteristics of the resultant composite coatings were correlated with the compositional modifications that occurred within the alloy matrix and expressed via a) TiO2 co-deposition rate and b) composition of the matrix; this was due to the application of different current types (DC or PC electrodeposition), and different current density values. The results demonstrated that under DC electrodeposition, the current density exhibited a more significant impact on the composition of the alloy matrix than on the incorporation rate of the TiO2 nanoparticles. Additionally, PC electrodeposition favored the incorporation rate of TiO2 nanoparticles only when applying a low peak current density (Jp = 1 Adm-2). All of the composite coatings exhibited the characteristic cauliflower-like structure, and were characterized as nano-crystalline. The composites' surface roughness demonstrated a significant influence from the TiO2 incorporation rate. However, in terms of microhardness, higher co-deposition rates of embedded TiO2 nanoparticles within the alloy matrix were associated with decreased microhardness values. The best wear performance was achieved for the composite produced utilizing DC electrodeposition at J = 1 Adm-2, which also demonstrated the best photocatalytic behavior under UV irradiation. The corrosion study of the composite coatings revealed that they exhibit passivation, even at elevated anodic potentials.

Highly Efficient Aligned Ion-Conducting Network and Interface Chemistries for Depolarized All-Solid-State Lithium Metal Batteries

HighlightsThis study introduces an innovative 3D-printed electrolyte with vertically aligned ion transport network, which contains well-dispersed nanoscale Ta-doped Li7La3Zr2O12 in a poly(ethylene glycol) diacrylate matrix.The 3DSE architecture enables efficient ion transport across the Li/electrolyte and electrolyte/cathode interfaces, which allows for increased active material mass loading and enhanced interfacial adhesion.The p-3DSE Li symmetric cell displays an impressive critical current density value of 1.92 mA cm−2 and stable operation for 2600 h at room temperature. Full cells using p-3DSE achieve notable areal capacities.

Study of operation of a polymer insulator under uniform and non-uniform contamination

RELEVANCE. Suspended insulators, the technical condition of which largely determines the reliability of power supply to consumers of different categories, are one of the most damaged elements of overhead power transmission lines [1-2]. This is primarily due to the fact that during their operation, insulators are exposed to various climatic conditions that have a direct impact on their insulating properties. Moreover, precipitation, such as rain, fog or dew, has the greatest impact precisely in combination with various solid, liquid and gaseous particles deposited on the insulator surface from the air, and forming a layer of surface contamination. Wetting this layer increases the electrical conductivity of the entire overhead line insulation structure and reduces its insulating capacity. Study of influence of dampening of contaminated surface of suspended insulation on their discharge characteristics is an urgent scientific task. The solution of this task enables to develop the existing understanding of the mechanisms of formation and development of discharges on the contaminated and wetted surface of insulation and to formulate the appropriate diagnostic attributes applicable to control the condition of the overhead power line insulators. OBJECTIVE. To carry out laboratory research aimed at studying the behavior of suspended high-voltage polymer insulators of overhead power lines when they are moistened. To formulate appropriate diagnostic attributes applicable for control of condition of suspended insulators of overhead power lines during their operation. METHODS. At the solution of the posed problem experimental methods of research, consisting in simulation of work of the contaminated polymeric insulator in the atmosphere of a pure fog with application of the special experimental installation developed by the authors of this article were applied. RESULTS. As a result of laboratory research, by continuous registration of leakage current values, as well as signals coming from the remote sensor, characteristic features of contaminated insulator humidification were revealed, which can be used as diagnostic signs in the process of their operation.

Design and Validation of a Photoelectric Current Measuring Unit for Lunar Daytime Simulation Chamber

Charging of the lunar surface induced by solar radiation can potentially threaten in situ resource utilization. Associated issues include dust adhesion and material degradation. Photoelectric currents are the primary cause of surface charging. This work reports on the development of a unit capable of measuring photoelectric currents in a vacuum chamber, which can simulate surface charging under conditions similar to those on the moon in daytime. The main components of the unit are a mesh grid, a photocathode specimen, and a ring collector. Photoelectric currents from an aluminum sample were measured by adjusting the electric potential of these components, and the impact of the electric potential of each component is discussed. Calculating the expected electric current within the experimental setup allowed validation of the current measurements: the measured and calculated values agreed well with an error of ~5.5%. Finally, the photoelectric currents for various metals (aluminum, nickel, and copper) were measured using the same experimental setup. The results showed consistent measurement of photoelectric current values across all metals. This study offers insights into the development of units for measuring photoelectric current and methodologies to validate their results.

From Hubble to snap parameters: a Gaussian process reconstruction

ABSTRACT By using recent H(z) and supernovae Type Ia (SNe Ia) data, we reconstruct the evolution of kinematic parameters H(z), q(z), jerk, and snap, using a model-independent, non-parametric method, namely, the Gaussian processes. Throughout the present analysis, we have allowed for a spatial curvature prior, based on Planck 18 constraints. In the case of SNe Ia, we modify a python package (gapp) in order to obtain the reconstruction of the fourth derivative of a function, thereby allowing us to obtain the snap from comoving distances. Furthermore, using a method of importance sampling, we combine H(z) and SNe Ia reconstructions in order to find joint constraints for the kinematic parameters. We find for the current values of the parameters: H0 = 67.2 ± 6.2 km s−1 Mpc−1, $q_0 = -0.54^{+0.06}_{-0.05}$, $j_0=0.94^{+0.20}_{-0.18}$, and $s_0=-0.62^{+0.26}_{-0.25}$ at 1σ c.l. We find that these reconstructions are compatible with the predictions from flat lambda-cold dark matter model, at least for 2σ confidence intervals.