scholarly journals Nanostructured Black Nickel Coating as Replacement for Black Cr(VI) Finish

2021 ◽  
Vol 11 (9) ◽  
pp. 3924
Author(s):  
Marina M. Mennucci ◽  
Rodrigo Montes ◽  
Alexandre C. Bastos ◽  
Alcino Monteiro ◽  
Pedro Oliveira ◽  
...  
Keyword(s):  
Room Temperature ◽  
Electrochemical Impedance ◽  
Nickel Coating ◽  
Incident Light ◽  
Optimal Conditions ◽  
Nanostructured Surface ◽  
Pre Treatment ◽  
Good Coating ◽  
A Current ◽  
Black Color

This work compares different electrodeposition procedures to produce nickel black coatings as greener and less toxic alternatives to Cr(VI)-based coatings used in different applications. Nickel and nickel-plated brass served as substrates in studies with a Hull cell and polarization curves. After a set of comparative experiments, the best electrodeposition procedure was further studied and optimized. Optimal conditions were found with a bath consisting of 75 g/L NiCl2·6H2O + 30 g/L NaCl and a current density of 0.143 A dm−2 applied for 5 min at room temperature. Furthermore, a pre-treatment with 18.5 vol.% of hydrochloric acid in water was found to be necessary to warrant good coating adhesion to the substrate. The black color is attributed to the development of a nanostructured surface that absorbs the incident light. Corrosion testing was performed in 0.5 M NaCl aqueous solution using electrochemical impedance spectroscopy (EIS) and polarization tests.

scholarly journals Sulfation–Roasting–Leaching–Precipitation Processes for Selective Recovery of Erbium from Bottom Ash

2019 ◽  
Vol 11 (12) ◽  
pp. 3461 ◽  
Author(s):  
Josiane Ponou ◽  
Marisol Garrouste ◽  
Gjergj Dodbiba ◽  
Toyohisa Fujita ◽  
Ji-Whan Ahn
Keyword(s):  
Room Temperature ◽  
Treatment Process ◽  
Bottom Ash ◽  
Ammonium Oxalate ◽  
Optimal Conditions ◽  
Selective Recovery ◽  
Sulfation Roasting ◽  
Roasting Temperature ◽  
Pre Treatment ◽  
H 30

Bottom ash (BA) is mainly composed of compounds of Al, Fe, Ca, and traces of rare earth elements (REEs). In this study, the selective recovery of erbium (Er) as REEs by means of sulfation–roasting–leaching–precipitation (SRLP) using BA was investigated. A pre-treatment process of sulfation and roasting of BA was developed to selectively recover REEs using ammonium oxalate leaching (AOL) followed by precipitation. Most of the oxides were converted to their respective sulfates during sulfation. By roasting, unstable sulfates (mostly iron) decomposed into oxides, while the REE sulfates remained stable. Roasting above 600 °C induces the formation of oxy-sulfates that are almost insoluble during AOL. Dissolved REEs precipitate after 7 days at room temperature. The effects of particle size, roasting temperature, leaching time, and AOL concentration were the important parameters studied. The optimal conditions of +100–500 μm particles roasted at 500 °C were found to leach 36.15% of total REEs in 2 h 30 min and 94.24% of the leached REEs were recovered by precipitation. A total of 97.21% of Fe and 94.13% of Al could be separated from Er.

scholarly journals All organic multiferroic magnetoelectric complexes with strong interfacial spin-dipole interaction

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Yuying Yang ◽  
Zhiyan Chen ◽  
Xiangqian Lu ◽  
Xiaotao Hao ◽  
Wei Qin
Keyword(s):  
Magnetic Field ◽  
Light Intensity ◽  
Room Temperature ◽  
Incident Light ◽  
Dipole Interaction ◽  
Interfacial Interaction ◽  
Magnetoelectric Coupling ◽  
Incident Light Intensity ◽  
Organic Ferromagnets ◽  
Magnetoelectric Coefficient

AbstractThe organic magnetoelectric complexes are beneficial for the development on flexible magnetoelectric devices in the future. In this work, we fabricated all organic multiferroic ferromagnetic/ferroelectric complexes to study magnetoelectric coupling at room temperature. Under the stimulus of external magnetic field, the localization of charge inside organic ferromagnets will be enhanced to affect spin–dipole interaction at organic multiferroic interfaces, where overall ferroelectric polarization is tuned to present an organic magnetoelectric coupling. Moreover, the magnetoelectric coupling of the organic ferromagnetic/ferroelectric complex is tightly dependent on incident light intensity. Decreasing light intensity, the dominated interfacial interaction will switch from spin–dipole to dipole–dipole interaction, which leads to the magnetoelectric coefficient changing from positive to negative in organic multiferroic magnetoelectric complexes.

Room Temperature Band-Edge Luminescence from Silicon Grains Prepared by the Recrystallization of Mesoporous Silicon

1996 ◽  
Vol 452 ◽  
Author(s):  
Karen L. Moore ◽  
Leonid Tsybeskov ◽  
Philippe M. Fauchet ◽  
Dennis G. Hall
Keyword(s):  
Room Temperature ◽  
Silicon Oxide ◽  
Crystalline Silicon ◽  
Band Edge ◽  
Applied Bias ◽  
Mesoporous Silicon ◽  
Room Temperature Photoluminescence ◽  
Band Edge Luminescence ◽  
A Current ◽  
Better Than

AbstractRoom-temperature photoluminescence (PL) peaking at 1.1 eV has been found in electrochemically etched mesoporous silicon annealed at 950°C. Low-temperature PL spectra clearly show a fine structure related to phonon-assisted transitions in pure crystalline silicon (c-Si) and the absence of defect-related (e.g.P-line) and impurity-related (e.g.oxygen, boron) transitions. The maximum PL external quantum efficiency (EQE) is found to be better than 0.1% with a weak temperature dependence in the region from 12K to 400K. The PL intensity is a linear function of excitation intensity up to 100 W/cm2. The PL can be suppressed by an external electric field ≥ 105 V/cm. Room temperature electroluminescence (EL) related to the c-Si band-edge is also demonstrated under an applied bias ≤ 1.2 V and with a current density ≈ 20 mA/cm2. A model is proposed in which the radiative recombination originates from recrystallized Si grains within a non-stoichiometric Si-rich silicon oxide (SRSO) matrix.

Effect of advanced oxidation processes on the toxicity of municipal landfill leachates

2004 ◽  
Vol 49 (4) ◽  
pp. 273-277 ◽  
Author(s):  
B. Slomczynska ◽  
J. Wasowski ◽  
T. Slomczynski
Keyword(s):  
Organic Compounds ◽  
Advanced Oxidation Processes ◽  
Vibrio Fischeri ◽  
Advanced Oxidation ◽  
Optimal Conditions ◽  
Toxicity Evaluation ◽  
Landfill Leachates ◽  
Oxidation Processes ◽  
Municipal Landfill ◽  
Pre Treatment

The aim of the present study was to assess the effect of advanced oxidation processes (AOPs) (oxidation ozone and peroxide/ozone) on the toxicity of leachates from municipal landfill for Warsaw, Poland, using a battery of tests. AOPs used to pre-treat leachates were carried out in laboratory conditions after their coagulation with the use of FeCl3. The effects of the pre-treatment of leachates using the method of coagulation with FeCl3 depended on the concentration of organic compounds and with optimal conditions of the process ranged from 40 to 70%. Further pre-treatment of the leachates after coagulation, involving the use of oxidation with O3 and H2O2/O3, did not cause significant decrease of leachate toxicity. The data of this study demonstrated the usefulness of the battery of tests using Daphnia magna, Artemia franciscana, Scenedesmus quadricauda and Vibrio fischeri for the toxicity evaluation of raw and pre-treated leachates.

scholarly journals A High Capacity, Room Temperature, Hybrid Flow Battery Consisting of Liquid Na-Cs Anode and Aqueous NaI Catholyte

Batteries ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 60 ◽  
Author(s):  
Caihong Liu ◽  
Leon Shaw
Keyword(s):  
Room Temperature ◽  
Electrochemical Impedance ◽  
Coulombic Efficiency ◽  
High Capacity ◽  
High Energy ◽  
Flow Battery ◽  
Membrane Interfaces ◽  
Number Of Cycles ◽  
Novel Concept ◽  
First Time

In this study, we have proposed a novel concept of hybrid flow batteries consisting of a molten Na-Cs anode and an aqueous NaI catholyte separated by a NaSICON membrane. A number of carbonaceous electrodes are studied using cyclic voltammetry (CV) for their potentials as the positive electrode of the aqueous NaI catholyte. The charge transfer impedance, interfacial impedance and NaSICON membrane impedance of the Na-Cs ‖ NaI hybrid flow battery are analyzed using electrochemical impedance spectroscopy. The performance of the Na-Cs ‖ NaI hybrid flow battery is evaluated through galvanostatic charge/discharge cycles. This study demonstrates, for the first time, the feasibility of the Na-Cs ‖ NaI hybrid flow battery and shows that the Na-Cs ‖ NaI hybrid flow battery has the potential to achieve the following properties simultaneously: (i) An aqueous NaI catholyte with good cycle stability, (ii) a durable and low impedance NaSICON membrane for a large number of cycles, (iii) stable interfaces at both anode/membrane and cathode/membrane interfaces, (iv) a molten Na-Cs anode capable of repeated Na plating and stripping, and (v) a flow battery with high Coulombic efficiency, high voltaic efficiency, and high energy efficiency.

Gel Electrolyte Based Supercapacitors with Higher Capacitances and Lower Resistances than Devices with a Liquid Electrolyte

MRS Advances ◽  
2018 ◽  
Vol 3 (22) ◽  
pp. 1261-1267 ◽  
Author(s):  
Belqasem Aljafari ◽  
Arash Takshi
Keyword(s):  
Polymer Electrolytes ◽  
Room Temperature ◽  
Electrochemical Impedance ◽  
Liquid Electrolyte ◽  
Gel Electrolyte ◽  
Superior Performance ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Gel Electrolytes ◽  
Further Development

ABSTRACTRecently, gel polymer electrolytes (GPEs) have been drawn noteworthy attention for different applications, specifically, for supercapacitors. GPEs could become an excellent substitute to liquid electrolytes (LEs) for making flexible and more durable devices. The performance of two different electrolytes (GPEs and LEs) in multi-wall carbon nanotube based supercapacitors were investigated. In spite of significantly lower conductivity of GPEs than LEs, devices with the gel electrolyte presented a superior performance. More focused has been given in this work on demonstrating the performance of supercapacitors based on GPEs and LEs at different concentrations of the acids ranging from 1M to 3M. Both electrolytes have been characterized at room temperature by making supercapacitors and using cyclic voltammetry, charging-discharging, electrochemical impedance spectroscopy, and leakage tests. The experimental results showed that GPE devices had much better capacitances and resistances compare to the LE based devices. Moreover, the capacitances of all devices were increased proportionally with the increase in the concentration from 1M to 3M, and the resistances were increased inversely with the decreased of concentration. The promising results from the gel electrolytes is encouraging for further development of flexible and high capacitance energy storage devices.

scholarly journals Clinical Characteristics of PMS Co-Morbid with MDD and Effectiveness of SSRIs in its Treatment

2020 ◽  
Vol 47 (4) ◽  
pp. 24-30
Author(s):  
R. Yakimova ◽  
M. Stoimenova-Popova ◽  
P. Chumpalova ◽  
M. Pandova ◽  
M. Stoyanova
Keyword(s):  
Major Depressive Disorder ◽  
Clinical Picture ◽  
Premenstrual Syndrome ◽  
Clinical Characteristics ◽  
Antidepressant Treatment ◽  
Somatic Symptoms ◽  
Major Depressive ◽  
Longitudinal Observational Study ◽  
Pre Treatment ◽  
A Current

AbstractBackground: Data on the clinical characteristics of premenstrual syndrome (PMS) with co-morbid major depressive disorder (MDD) are scarce. Although selective serotonin re-uptake inhibitors (SSRIs) are widely used to treat both PMS and MDD there is little information on their efficacy in PMS in patients with co-morbid MDD.Objective: To describe the clinical picture of PMS co-morbid with current depressive episode (DE) and evaluate its dynamics under a 6-month course of SSRIs treatment.Materials and methods: We present a longitudinal observational study, conducted in out- and inpatient conditions. Thirty-one women eligible to antidepressant treatment for a current DE in the course of MDD were evaluated for PMS and those of them suffering from both conditions were re-evaluated twice during a 6-month medication intake period.Results: The pre-treatment clinical picture of PMS co-morbid with MDD was dominated by moderately to severely expressed mood swings, anxiety, fatigue, breast tenderness, palpitations, abdominal bloating, and headache. After six months of SSRIs intake the syndrome was characterised by nearly the same symptoms (with the addition of irritability and appetite changes) but mildly expressed.Conclusion: Untreated PMS co-morbid with MDD is characterised by mainly moderately severe psychological and around three times less commonly – somatic symptoms. SSRIs treatment alleviate both symptom types at month three and even further, although less pronouncedly at month six.

scholarly journals Studi Kemampuan Penyerapan Panas pada Atap Rumah Seng Berwarna Terhadap Intensitas Matahari dalam Mengatasi Global Warming

2020 ◽  
Vol 4 (3) ◽  
pp. 114
Author(s):  
Nazaruddin Nazaruddin ◽  
Teuku Zulfadli ◽  
Andi Mulkan
Keyword(s):  
Global Warming ◽  
Temperature Difference ◽  
Research Method ◽  
Room Temperature ◽  
Environmental Temperature ◽  
Heat Absorption ◽  
Temperature Observation ◽  
Yellow Color ◽  
Black Color

The environmental temperature has increased significantly reaching 33oC as felt by the community, one of which is in the Aceh region which triggers Global Warming. As a result of the increase in temperature in the Aceh area, many buildings and houses become uncomfortable especially during the daytime because most house with zinc roof. This will cause the temperature in the house and the air around it to increase. Therefore, it is necessary to do research on the study of heat absorption on colored zinc roofs. This research method is to calculate the heat absorption (sun intensity) in zinc that has been coated with several kinds of colors such as white, red, blue, yellow and black. The purpose of this study was to determine the color that has the least amount of heat absorption to the sun's intensity. The highest room temperature on zinc-coated black is 49.2° C and the lowest is in white.  40.9°C from the pen. In the environmental temperature observation, there is the highest temperature at 12.00.  Room temperature increased the highest temperature at 12.00 on black zinc.  The distribution of room temperature can be averaged with a yellow color of 46.0°C, a black color of 49.2°C, a blue of 45.5°C and a white zinc of 40.9 oC.  The heat absorbed in the room is 47.9 joules, so from the overall average of the test it can be described that the room temperature is 45.6 and the zinc temperature is 53.8oC from the highest temperature difference at 12.00 WIB, room temperature and 13.00 WIB the highest absorption occurs at zinc temperature.

scholarly journals Evaluation of the Corrosion Resistance of WC-Co Coating on AZ91 Applied by Electro Spark Deposition

2020 ◽  
Vol 20 (1) ◽  
pp. 30-40
Author(s):  
Arvin Taghizadeh Tabrizi ◽  
Maryam Pouzesh ◽  
Farhad Farhang Laleh ◽  
Hossein Aghajani
Keyword(s):  
Corrosion Rate ◽  
Room Temperature ◽  
Electrochemical Impedance ◽  
Bulk Sample ◽  
Az91 Alloy ◽  
Corrosion Performance ◽  
Surface Microhardness ◽  
Optimum Parameters ◽  
Temperature Polarization ◽  
First Time

Abstract In order to enhance the surface properties of a magnesium-based substrate, WC-Co coating was applied on AZ91 alloy by electro spark deposition (ESD), successfully for the first time. The optimum parameters of the ESD process were achieved, based on the corrosion behavior and calculated corrosion rate of the coated samples when 5kHz and 25 A were chosen. For evaluation of the corrosion performance of the achieved WC-Co layers, polarization, and electrochemical impedance spectroscopy tests were carried out in the 3.5 wt % Na3PO4 solution at room temperature. Polarization results show that the corrosion rate (mpy) is in the optimum condition almost half of a bulk sample of uncoated AZ91. Field emission scanning electron microscopy (FE-SEM) was used to examine the surface morphology of applied coatings. These results show that at a lower current, the amount of deposited WC-Co was reduced. The maximum surface microhardness obtained was 193 HV0.2.

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