159 research outputs found
Pressure of Societal Commitment Norm in Iran
Abstract Societal commitment involves sympathy and emotional attachment of actors to society and implies preference for public interest over self-interest. Secondary analysis of the Iranian Social Integration survey data shows that 64.6% of Iranians are socially committed and whenever faced with a dilemma of collective vs. self, they prefer public interest to self-interest and they assume it is expected to do so. On the contrary, 17.3% of the people are not socially committed and prefer their own self-interest according to their own perception of general expectation of others. Also, 18.1% of the people have their own definitions of responsible behavior and their actions are assorted according to their own personal norms. The mean of pressure of societal commitment norm (conscious pressure for responsible behavior) is 62.7(on a 100 base scale) and pressure for responsibility is stronger than irresponsibility
Electrodeposition of Ni–Co–Fe mixed sulfide ultrathin nanosheets on Ni nanocones: a low-cost, durable and high performance catalyst for electrochemical water splitting
Numerical Simulation of Breast Cancer in the Early Diagnosis with Actual Dimension and Characteristics Using Photoacoustic Tomography
A numerical study and simulation of breast imaging in the early detection of tumors using the photoacoustic (PA) phenomenon are presented. There have been various reports on the simulation of the PA phenomenon in the breast, which are not in the real dimensions of the tissue. Furthermore, the different layers of the breast have not been considered. Therefore, it has not been possible to rely on the values and characteristics of the resulting data and to compare it with the actual state. Here, the real dimensions of the breast at three-dimensional and different constituent layers have been considered. After reviewing simulation methods and software for different stages of the PA phenomenon, a single suitable platform, which is commercially available finite element software (COMSOL), has been selected for simulating. The optical, thermal, elastic, and acoustic characteristics of different layers of breast and tumor at radiated laser wavelength (800 nm) were accurately calculated or obtained from a reliable source. Finally, by defining an array of 32 ultrasonic sensors on the breast cup at the defined arcs of the 2D slices, the PA waves can be collected and transmitted to MATLAB software to reconstruct the images. We can study the resulting PA wave and its changes in more detail using our scenarios
Recent advances in methods and technologies for enhancing bubble detachment during electrochemical water splitting
Development of new electrocatalysts with high electrocatalytic activity and stability is of great importance in the production of hydrogen fuel. Numerous methods have been established to increase the activity of electrocatalysts, including increasing active surface area and improving intrinsic catalytic activity. However, the electrochemical water splitting is a gas-involving reaction in which hydrogen and oxygen bubbles are formed on cathode and anode surfaces, respectively, which lead to an increase in overpotential of electrochemical reactions. In this review, recent advances have been complied to understand the behavior of hydrogen and oxygen bubbles separation from the surface of electrodes during water splitting. Initially, various types of resistance in water splitting have been discussed, and further progress has been discussed to improve the separation of bubbles and thus improve electrocatalytic activity. These improvements include surface nanostructuring and making superaerophobic surfaces where bubbles can easily be removed from the surface, resulting in lower bubble resistance. Furthermore, the use of magnetic, supergravity and ultrasonic fields are among additional methods for fast separation of bubbles from the surface and improving catalytic activity This paper presents a review of a research pathway for creating 3D nanoarrays to improve the bubble separation behavior on the surface and improve electrocatalytic properties. © 2019 Elsevier Ltd1
Surface modification of Ni foam by the dendrite Ni-Cu electrode for hydrogen evolution reaction in an alkaline solution
Pulse Electrodeposition of a Superhydrophilic and Binder-Free Ni-Fe-P Nanostructure as Highly Active and Durable Electrocatalyst for Both Hydrogen and Oxygen Evolution Reactions
Development and fabrication of electrodes with favorable electrocatalytic activity, low-cost, and excellent electrocatalytic durability are one of the most important issues in the hydrogen production area using the electrochemical water splitting process. We use the pulse electrodeposition method as a versatile and cost-effective approach to synthesize three-dimensional Ni-Fe-P electrocatalysts on nickel nanostructures under various applied frequencies and duration times, in which nanostructures exhibit excellent intrinsic electrocatalytic activity. Benefiting from the three-dimensional structure, as well as the simultaneous presence of the three elements nickel, iron, and phosphorus, the electrode fabricated at the optimal conditions has indicated outstanding electrocatalytic activity with a η10 of 66 and 198 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, in a 1.0 M KOH solution. Also, the water electrolysis cell constructed with this electrode and tested as a bifunctional electrode exhibited 1.508 V for 10 mA cm-2 in overall water splitting. In addition, the lowest amount of potential change in 100 mA cm-2 was observed for HER and OER, indicating excellent electrocatalytic stability. This study proposes a binder-free and economical technique for the synthesis of three-dimensional electrocatalysts. © 2020 American Chemical Society.FALS
Electrodeposition of self-supported transition metal phosphides nanosheets as efficient hydrazine-assisted electrolytic hydrogen production catalyst
The synthesis of electrocatalysts which used simultaneously as electrodes for the hydrazine oxidation reaction (HzOR), and hydrogen evolution reaction (HER) can significantly improve the efficiency of hydrogen production in the water splitting process. Here, Ni–Co–Fe–P binder-free nanosheets were fabricated using the electrochemical deposition method and used as an effective, stable, and cost-effective electrode for hydrazine-assisted electrochemical hydrogen production. Taking advantage of high surface area, being binder-free, and synergistic effect between the elements in the electrode composition, this electrode showed unique electrocatalytic activity and stability. When this electrode was used as a bifunctional electrode for HzOR-HER, a cell voltage of 94 mV was required to reach a current density of 10 mA cm−2. The results of this study indicated that the Ni–Co–Fe–P electrode is an excellent candidate for the hydrogen production industry. © 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.FALS
Plasma electrolytic oxidation of magnesium and its alloys: Mechanism, properties and applications
Plasma Electrolyte Oxidation (PEO) process has increasingly been employed to improve magnesium surface properties by fabrication of an MgO-based coating. Originating from conventional anodizing procedures, this high-voltage process produces an adhesive ceramic film on the surface. The present article provides a comprehensive review around mechanisms of PEO coatings fabrication and their different properties. Due to complexity of PEO coatings formation, a complete explanation regarding fabrication mechanisms of PEO coatings has not yet been proposed; however, the most important advancements in the field of fabrication mechanisms of PEO coatings were gathered in this work. Mechanisms of PEO coatings fabrication on magnesium were reviewed considering voltage–time plots, optical spectrometry, acoustic emission spectrometry and electronic properties of the ceramic film. Afterwards, the coatings properties, affecting parameters and improvement strategies were discussed. In addition, corrosion resistance of coatings, important factors in corrosion resistance and methods for corrosion resistance improvement were considered. Tribological properties (important factors and improvement methods) of coatings were also studied. Since magnesium and its alloys are broadly used in biological applications, the biological properties of PEO coatings, important factors in their biological performance and existing methods for improvement of coatings were explained. Addition of ceramic based nanoparticles and formation of nanocomposite coatings may considerably influence properties of plasma electrolyte oxidation coatings. Nanocomposite coatings properties and nanoparticles adsorption mechanisms were included in a separate sector. Another method to improve coatings properties is formation of hybrid coatings on PEO coatings which was discussed in the end. Keywords: Plasma electrolytic oxidation, Magnesium, Tribological properties, Biomedical properties, Nanocomposite coating
Hydrazine-assisted electrochemical hydrogen production by efficient and self-supported electrodeposited Ni-Cu-P@Ni-Cu nano-micro dendrite catalyst
The emergence of high-performance noble metal-free electrodes in water splitting operations to produce hydrogen is of paramount importance to generate new energy in the future. The oxygen evolution reaction (OER) in water splitting is a slow reaction that consumes much energy to produce hydrogen, and generally, replacing an anodic reaction with less thermodynamic potential can significantly improve the efficiency of hydrogen production. The hydrazine oxidation reaction (HzOR) can be a great alternative to OER. We describe the fabrication of Ni-Cu-P@Ni-Cu nano-micro dendrite using a simple electrodeposition method. The developed Ni-Cu-P@Ni-Cu is used as a bifunctional electrode for hydrogen evolution reaction (HER) and HzOR. The high active electrochemical area, the porous structure and the penetration of electrolyte into the pores, the synergistic effect between Ni and Cu, and the rapid separation of the bubbles created from the surface led to the creation of an electrode with excellent electrocatalytic activity. The HER and HzOR processes required only -70 mV vs.RHE and 3.88 mV vs.RHE potentials in 1.0 M KOH and 1.0 M KOH + 0.5 M N2H4, respectively, to generate a current density of 10 mA.cm−2. Also, a very low potential of 125 mV was required in the hybrid overall water electrolysis system. This study presents a new, cost-effective, versatile, and industrial strategy to fabricate three-dimensional electrocatalysts. © 2021 Elsevier Ltd1
Electrodeposition of Ni-Co-Fe mixed sulfide ultrathin nanosheets on Ni nanocones: A low-cost, durable and high performance catalyst for electrochemical water splitting
The development of a bi-functional active and stable catalyst for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is an important challenge in overall electrochemical water splitting. In this study, firstly, nickel nanocones (NNCs) were formed using electrochemical deposition, and then Ni-Co-Fe based mixed sulfide ultrathin nanosheets were obtained by directly depositing on the surface of the nanocones using the CV method. With a hierarchical structure of Ni-Fe-Co-S nanosheets, not only was a high active surface area created, but also the electron transfer and mass transfer were enhanced. This structure also led to the faster release of hydrogen bubbles from the surface. An overpotential value of 106 mV was required on the surface of this electrode to generate a current density of 10 mA cm-2 in the HER, whereas, for the OER, 207 mV overpotential was needed to generate a current density of 10 mA cm-2. Furthermore, this electrode required 1.54 V potential to generate a current density of 10 mA cm-2 in the total electrochemical water splitting. The resulting electrode also exhibited reasonable electrocatalytic stability, and after 10 hours of electrolysis in the overall water splitting reaction, the voltage change was negligible. This study introduces a simple, efficient, reasonable and cost-effective method of creating an effective catalyst for the overall water splitting process. © 2019 The Royal Society of Chemistry.1
- …