Galvanic Cell Type Research Articles

Heterogeneously structured FeCuBP amorphous–nanocrystalline alloy with excellent dye degradation efficiency

Fe-based amorphous alloys have drawn wide attention in dye degradation due to the superior properties and adjustable compositions. As a new component of Fenton-like catalyst, Fe80Cu4B14P2 amorphous alloy with few nanocrystals has been prepared by melt spinning method without additional process for the first time in this paper. Furthermore, Fe80Cu4B14P2 amorphous–nanocrystalline alloy shows the better degradation performance than fully amorphous and crystalline counterparts, which is originated from structural and chemical inhomogeneities in nanoscale. Two distinct types of galvanic cells are formed between copper-rich nanocrystals and amorphous matrix, iron-rich and iron-poor regions, respectively, accelerating the transfer of electrons and the production of ·OH radicals in Fenton-like system. Besides, the formation of special three-dimensional (3D) network structures on ribbon during degradation is also an important reason for the high degradation efficiency. This work not only proposes novel and promising FeCuBP amorphous–nanocrystalline alloy as catalyst in the wastewater treatment field, but also provides a new perspective on heterogeneous materials designing and fabricating.

The Pivotal Role of Boron in Improving the Azo Dye Degradation of Glassy Fe‐based Catalysts

AbstractFe‐based metallic glasses have been confirmed to degrade azo dyes effectively, however, a detailed understanding, of the role of alloying elements and crystallization is still elusive. Herein, it is reported that boron‐facilitated hybrid structures greatly improve the degradation of methyl orange (MO) and the degrading rate can be further improved by 2.5 times after fully crystallization. Three distinct types of galvanic cells created by different iron‐containing phases are believed to dominate the degradation reactions. Most notably, some FeB‐based compounds precipitated from FeB‐based metallic glasses, such as Fe2B, FeB and Fe5SiB2, are found to have more negative electrode potential and higher catalytic efficiency than iron. These compounds create galvanic cells with α‐Fe and lose electrons, therefore promoting the degradation reaction. The favorable effects of the FeB‐based compounds are discussed at the light of their electron densities and energy band structures. These findings open a new research strategy to developing iron‐bearing catalysts for improved degradation of azo dyes.

Automated Calibration of Electrochemical Oxygen Sensors for Use in Compost Bedded Pack Barns

Abstract. The objective of this study was to develop an automated calibration process for a galvanic cell type oxygen sensor. The manufacturer recommended a two-point calibration at room temperature; however, testing revealed that the response was not linear when both the temperature and oxygen concentrations varied. Thus, additional points were needed to generate a representative calibration equation and to reduce the sensor prediction interval. The calibration process needed to be capable of automatically recording sensor response (voltage) at an array of temperatures and oxygen concentrations. Calibration gases were used to precisely control the oxygen concentration inside a small manifold, and an electronically controlled water bath was used to regulate the sensor and gas temperature. A custom computer program controlled the sampling order and the data collection process. The responses for three sensors were recorded at six temperature (10°C, 20°C, 30°C, 40°C, 50°C, and 60°C) and five oxygen concentration (0%, 5%, 10%, 15%, and 20% O2 absolute) combinations, for a total of 30 measurements per calibration. Calibration data were used to create a second-degree polynomial model with oxygen sensor voltage and temperature as input parameters, which reduced the prediction interval by over 1% O2 for each of the three sensors tested. The resulting prediction intervals ranged between 0.75% and 0.95% O2. Three sensors were mounted in a prototype oxygen probe and tested under controlled conditions to demonstrate the ability to measure oxygen concentration versus depth in a composting environment. Keywords: Aeration, Calibration, Compost, Dairy, Housing, Oxygen.

High temperature Ag+β”-alumina in situ sensor for sulfur-containing gases

The paper reports the development of high temperature in situ fully solid electrochemical sensor for sulfur-containing gases monitoring. The sensor is based on Ag+β”-Al2O3 membrane with Ag2S or Ag2SO4 layer on its surface. Silver beta alumina was manufactured by high temperature ion exchange technique in AgNO3 melt. The original design of the in situ sensor was developed. Three types of galvanic cells were used for the investigation of electromotive force (EMF) response on SO2 partial pressure both in oxygen-free and oxygen-containing atmosphere in the temperature range 673–923 K. The data obtained was compared with following Nernst equations. The applicability of the sensor for in situ measurements in industrial processes is discussed.

High Precision Measurement of Oxygen Diffusion Coefficient in Micro Porous Media Using a Galvanic Cell Type Oxygen Absorber

One of the important factors of cell performance in polymer electrolyte fuel cell (PEFC) is moisture control in gas diffusion layer (GDL). It is necessary to clarify the mass transfer characteristics in GDL. The oxygen diffusion coefficient in GDL is measured with a galvanic battery type oxygen absorber. Particularly, measurement in high accuracy of oxygen diffusion coefficient in GDL becomes important. In the previous study, the measurement of the effective oxygen diffusivity in the microporous GDL using the galvanic cell type oxygen absorber was proposed. In addition, the measurement of the effective oxygen diffusivity in the microporous GDL containing moisture was proposed and shown to be an effective technique for measurement of the effective oxygen diffusivity in microporous media. However, because the diffusion resistance of dry GDL is small, the error margin of tens of percent existed in the result of a measurement of the oxygen diffusivity. In the present study, the objective of this study is high precision measurement of the oxygen diffusion coefficient in GDL by specifying the error factors and improving them.

Oxygen potential measurements of Cm0.09Pu0.91O2−x by EMF method

The dependence of the oxygen potentials on oxygen nonstoichiometry (x) and temperature of Cm0.09Pu0.91O2−x was measured by electromotive force (EMF) measurements. The galvanic cell type is shown: (Pt) air | Zr(Ca)O2−x | Cm0.09Pu0.91O2−x (Pt). The coulomb titration has been made for the sample at the intervals of 40 K between 1173 and 1333 K over the x range of 0.018 ≤ x ≤ 0.053. The oxygen potentials decreased gradually from −31.02 to −117.48 kJmol−1 with increasing x from 0.018 to 0.045, and more rapidly decreased from −117.48 to −283.74 kJmol−1 up to 0.053. The temperature dependence of the oxygen potentials was also measured between 1173 and 1333 K for several constant x values. The temperature dependences exhibited the smooth curves over the x and temperature ranges concerned. Systematic comparison of the oxygen potentials between Cm0.09Pu0.91O2−x and those published for CmO2 −x and Am-containing oxides was also made. The oxygen potential of Cm09Pu0.91O2−x at the equimolar ratio of Cm3+/Cm4+ was higher than those of AmyPu1−yO2−x at the equimolar ratio of Am3+/Am4+ by approximately 150 kJmol−1 when the Pu valence was assumed to be +4 in both oxides.

Prospect of hydrogen technology using proton-conducting ceramics

This paper reviews possible hydrogen devices using a proton-conducting ceramic and describes the prospect of hydrogen technology utilizing these devices. Solid-state protonic devices can be classified into two categories: the devices utilizing electromotive force (EMF) and the ones utilizing preferential transport of protons. Galvanic cell type hydrogen sensors and fuel cells belong to the former, and hydrogen pump, steam electrolyzer and membrane reactors to the latter. Various kinds of modifications can be derived, in principle, from these devices. In this paper, the working principles of these devices and status of the development are reviewed touching the future prospect of applications. In addition, the recent studies and the possibilities of protonic devices for nuclear fusion process in the future are introduced.

Application of hydrogen sensor using proton conductive ceramics as a solid electrolyte to aluminum casting industries

A galvanic cell type of hydrogen sensor was developed using CaZrO 3-based proton conductor as a solid electrolyte. It was clear that the hydrogen sensor could be used for the accurate determination of hydrogen concentration in molten aluminum alloys. The sensor probe exhibited stable EMF values and a fast response when the hydrogen concentration in the melt was changed. The application of this sensor to the real aluminum foundry was also investigated. This sensor could work very stably even when the flow rate of the liquid metal was very fast. In situ measurement was possible using this sensor anywhere in the casting shop, such as melting furnace, holding furnace, the degassing station, etc.

Technological challenges in the application of proton conducting ceramics

This paper describes technological challenges in the application of proton conducting ceramics developed in our laboratory. The proton conducting ceramics used here were perovskite-type oxide solid solutions based on cerate or zirconate. Galvanic cell type sensors for detecting hydrogen and other hydrogen-containing compounds could be fabricated using this kind of ceramics. Laboratory-scale hydrogen fuel cells, steam electrolyzers for hydrogen production, hydrogen extractors from gas mixtures and membrane reactors for organic compound gases were made by way of experiment using the ceramics as a solid electrolyte, and they were positively verified to work.

ChemInform Abstract: Galvanic Cell Type Humidity Sensor with NASICON‐Based Material Operative at High Temperature.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Galvanic cell type humidity sensor with NASICON-based material operative at high temperature

Galvanic cell type humidity sensor with NASICON-based material operative at high temperature

プロトン導電性セラミックスを用いた溶融アルミニウム中の水素濃度測定

In order to carry out in-situ measurement of hydrogen content in molten aluminum, a galvanic cell type hydrogen sensor was constructed using CaZr0.9In0.1O3-α as a solid electrolyte. This sensor exhibited stable electromotive force (emf) corresponding to hydrogen content (S). A linear relation was found between emf and logarithm of S2. The hydrogen content determined by this sensor was in good agreement with that measured by Telegas method.

Laboratory simulation of atmospheric corrosion by SO2—I. Apparatus, electrochemical techniques, example results

The atmospheric corrosion by SO2 has been simulated in the laboratory using a pollution gas box, PGB, which is described. Both two-electrode galvanic cell type atmospheric corrosion monitors, ACMs (Zn/Fe, cast Zn-55% Al/Fe, rolled Zn-55% Al/Fe), and three-electrode electrochemical cell type ACMs (Zn, Fe, cast Zn-55% Al, rolled Zn-55% Al) have been constructed using techniques modified from those available in the literature. Techniques for carrying out PGB experiments on metal samples in flowing laboratory air containing 0–1 ppm [SO2] are described. Techniques for weighed sample mass loss and ACM electrochemical tests (galvanic current, impedance, corrosion current) are given along with examples of typical electrochemical results. Methods for calculating mass loss from these electrochemical tests are indicated.

4827246 Hydrocarbon and water level sensor system used to monitor underground storage sites

Combination hydrocarbon and water level sensor systems for use in connection with underground storage sites, such as gasoline storage tanks, industrial waste sites, and the like, with a solar cell power source and an LCD display located above ground and providing directly viewable indication of the presence or absence in the underground environment of "HYDROCARBON" and/or "WATER", with the absence of such being indicated by "OK". In the preferred form, a pod containing an adsorptive type hydrocarbon gas sensor and a galvanic cell type liquid water sensor is suspended by electrical cable means from a well cap in which the solar cell and LCD display are installed.

High Temperature Humidity Sensing Materials

AbstractNew proton conducting materials were prepared and characterized for potential applications in humidity sensing at temperatures higher than 100°C by complex impedance or galvanic cell type techniques. Calcium metaphosphate, β-Ca(PO3)2as a galvanic cell type sensor material yields reproducible signals in the range from 5 to 200 nmm Hg water vapor pressure at 578°C, with short response time(-30 sec). Polycrystalline samples of α-Zr(HPO4)2and KMO3P5.8Si2O25, and the gel converted ceramic, 0.10Li2O-0.25P2O5-0.65SiO2as impedance sensor materials show decreases in impedance with increasing humidity in the range from 9 nmn Hg to 1 atm water vapor pressure at 179*C.

Effect of Additives on NiCl2 Developer for Galvanic Cell Type Electrophotography

Effect of Additives on NiCl2 Developer for Galvanic Cell Type Electrophotography

Sensitivity of Galvanic Cell Type Electrophotography as a Function of Developing Agent

Sensitivity of Galvanic Cell Type Electrophotography as a Function of Developing Agent

Activating Effect of Na2S203 on the Developing of Galvanic Cell Type Electrophotography

The present paper is concerned with a e!ectrophotogr-aph wbich is pteve. loped in NiCla solution through the cell reaction of (ZnO/NiCl2/Al). The maximum image density was obtained from the neutral electrolyte solution containing O.7 mol/1 NiCl, 0.7. -2, 8 mol/1 NH4Cl and O. Ol mol/l Na2S2O2. The deposition efficiency of nickel was low in acidic solutions. Nickel was deposited from its ammine complex ion which was stable at pH higher than 6. Thiosulfate ion was effective to accelerate the nickel deposition below the cortcentration of 10g mol/1, A direct electron transfer from Al electrode to Ni2 seemed to occur rapidly in the solution containing thiosulfate ion above 10-8 mol/1. The potential between the alminum plate 2-iffbr Tla-xef and a calomel electrode was influencedh. She Cl-m. concept r4Sign Schqrgsult fiihY rm66 ascribed to the increase Qf thg act3yllty of AIS: i ign, The potential mentioned above bec stable in the solution with lew free NiN concentration.