Measurements Of Transfer Rates Research Articles

Dynamic measurements of thermal boundary layer and heat transfer rates along a heated flat plate under the influence of ultrasonic field

Dynamic measurements of thermal boundary layer and heat transfer rates along a heated flat plate under the influence of ultrasonic field

Crossflow polymeric hollow fiber heat exchanger: fiber tension effects on heat transfer and airside pressure drop

In various applications, a polymeric hollow fiber heat exchanger (PHFHE) is a competitive alternative to a conventional heat exchanger (HE). Standard empirical models for predicting the crossflow tube HE characteristics are defined for devices with rigid tubes with relatively large diameters compared to the polymeric hollow fibers with an outer diameter of around 1 mm. This study examines the impact of tension force on airside heat transfer rate and pressure drop in a crossflow PHFHE. The tension force influences the stiffness of the flexible polymeric fibers and their response to applied airflow. Two liquid–gas PHFHEs were designed and manufactured to ensure uniformity of the fibers' arrangement (inline and staggered). An experimental stand enabling the application of defined tension force in the range of 0–9000 N was designed, manufactured and placed into the calorimetric tunnel, where heat transfer rate and pressure drop measurement were performed with varying air velocity between 2 and 8 ms−1 (corresponding to Reynolds number of 240–970). Among our key findings was that the elongation of the fibers due to thermal expansion or stress relaxation has a considerable impact on the fibers' arrangement and resulting fluid flow. Moreover, the application of tension force yielded no substantial change in air pressure drop; however, it led to a notable enhancement in heat transfer rate. Specifically, under a maximal tension force of 9000 N, the heat transfer rate increased by around 11% compared to the unloaded state.

ByteBuddy - A Storage Device Verification Tool

Abstract: ByteBuddy is a powerful tool for analyzing storage devices that basically features capacity confirmation and data transfer rate measurement. It fills the device with pseudorandom data to do a capacity check, reads back the data to confirm its integrity, and measures the data transmission speed all at the same time. The purpose of this test is to determine if the storage device's full advertised capacity is indeed usable, or if it isn't, revealing the device to be a fake. The significance of ByteBuddy lies in its ability to empower users to differentiate between genuine and fake storage devices, enabling them to make informed decisions when procuring these essential tools. This study paper offers a thorough analysis of ByteBuddy, illuminating its benefits and working principles. ByteBuddy adds to the larger conversation on data integrity and consumer protection in the digital age in addition to providing customers with a useful solution.

An Experimental Examination into the Efficiency of a Shell-and-Tube Heat Exchanger for an EGR Cooler

The increasing concerns over environmental pollution and stringent regulations on emission have led to the widespread adoption of exhaust gas recirculation (EGR) systems in interna combustion engines. EGR systems help reduce nitrogen oxide (NOx) emissions by recirculating a portion of exhaust gaes back into the combustion chamber. Howerver, the elevated temperature of exhaust gases poses challenges related to thermal management, necessitating the use of exhaust gas recirculation cooler. The experimental setup allows for the controlled circulation of exhaust gases and cooling fluids, thereby facilitating the measurement of heat transfer rates, pressure drops and overall thermal efficiency. These parameters encompass the inlet and outlet temperatures of both the exhaust gases and the cooling fluids flow rates for both fluids resulting pressure drops. By systematically altering these factors, the intricate, interplay between the various parameters and their inputs on the heat exchangers thermal performances are comprehensively explored. Addition, the research develops into critical aspects often overshadowed in EGR cooler studies on fouling. Overtime, the accumulation of deposits in the heat exchanger surface can led to reduced heat transfer efficiency. The outcomes of this study are instrumental for the advancement of EGR cooler technologies fostering more sustainable and environmentally friendly and automotive engines.

Spatially resolved investigation of flame particle interaction in a two dimensional model packed bed

This study investigates the interaction between a premixed methane-air flame and particles inside a model packed bed. The opacity of the spherical packed beds to visible light poses a major barrier to the implementation of highly resolved optical diagnostics, so that no detailed experimental data were so far available for the validation of numerical simulation. Here, a two-dimensional cylindrical packed bed design is set up, which enables direct line-of-sight optical measurements without loss of spatial resolution over the fluid region between the particles. In this study, the case of cold metallic cylindrical particles (T = 377 K) relevant to start-up of a reactor is investigated using internal particle cooling, which also allows cylinder specific heat transfer rate measurements by differential temperature measurements on the coolant streams. The two dimensional assumption is first verified by measuring the inflow velocity and cylinder temperature profile along the cylinders. Chemiluminescence imaging is then performed using a telecentric lens to observe the position and geometry of the two-dimensional flame front with respect to the surrounding cylinders without loss of resolution. Simultaneously, the cylinder-specific flame to cylinder heat transfer rates and cylinder surface temperature are measured. As the flame is closely surrounded by the three cooled cylinders, intense heat transfer is observed in this region corresponding to 25 ± 2.5% of the flame thermal power. Flames were stabilised at different positions depending on inflow velocity and equivalence ratio, and a direct correlation between flame to cylinder stand-off distance and the heat transfer rate normalised to the flame thermal power was found for both top and side cylinders. Also, sidewall quenching distances to the curved cylinder surfaces were evaluated, and seem to be influenced by the presence of a warm recirculation zone behind the cylinders. This investigation provides fully resolved flame front position and heat transfer rates for a known geometry and cylinder thermal boundary conditions, and provides validation data for numerical simulations of this high flame particle coupling case.

Assessing Ecosystem State Space Models: Identifiability and Estimation

Hierarchical probability models are being used more often than non-hierarchical deterministic process models in environmental prediction and forecasting, and Bayesian approaches to fitting such models are becoming increasingly popular. In particular, models describing ecosystem dynamics with multiple states that are autoregressive at each step in time can be treated as statistical state space models (SSMs). In this paper, we examine this subset of ecosystem models, embed a process-based ecosystem model into an SSM, and give closed form Gibbs sampling updates for latent states and process precision parameters when process and observation errors are normally distributed. Here, we use simulated data from an example model (DALECev) and study the effects changing the temporal resolution of observations on the states (observation data gaps), the temporal resolution of the state process (model time step), and the level of aggregation of observations on fluxes (measurements of transfer rates on the state process). We show that parameter estimates become unreliable as temporal gaps between observed state data increase. To improve parameter estimates, we introduce a method of tuning the time resolution of the latent states while still using higher-frequency driver information and show that this helps to improve estimates. Further, we show that data cloning is a suitable method for assessing parameter identifiability in this class of models. Overall, our study helps inform the application of state space models to ecological forecasting applications where (1) data are not available for all states and transfers at the operational time step for the ecosystem model and (2) process uncertainty estimation is desired.

Morphological nanolayer impact on hybrid nanofluids flow due to dispersion of polymer/CNT matrix nanocomposite material

<abstract> <p>The objective of this study is to explore the heat transfer properties and flow features of an MHD hybrid nanofluid due to the dispersion of polymer/CNT matrix nanocomposite material through orthogonal permeable disks with the impact of morphological nanolayer. Matrix nanocomposites (MNC) are high-performance materials with unique properties and design opportunities. These MNC materials are beneficial in a variety of applications, spanning from packaging to biomedical applications, due to their exceptional thermophysical properties. The present innovative study is the dispersion of polymeric/ceramic matrix nanocomposite material on magnetized hybrid nanofluids flow through the orthogonal porous coaxial disks is deliberated. Further, we also examined the numerically prominence of the permeability ($ {\mathrm{A}}_{\mathrm{*}} $) function consisting of the Permeable Reynold number associated with the expansion/contraction ratio. The morphological significant effects of these nanomaterials on flow and heat transfer characteristics are explored. The mathematical structure, as well as empirical relations for nanocomposite materials, are formulated as partial differential equations, which are then translated into ordinary differential expressions using appropriate variables. The Runge–Kutta and shooting methods are utilized to find the accurate numerical solution. Variations in skin friction coefficient and Nusselt number at the lower and upper walls of disks, as well as heat transfer rate measurements, are computed using important engineering physical factors. A comparison table and graph of effective nanolayer thermal conductivity (ENTC) and non-effective nanolayer thermal conductivity are presented. It is observed that the increment in nanolayer thickness (0.4−1.6), enhanced the ENTC and thermal phenomena. By the enhancement in hybrid nanoparticles volume fraction (2% to 6%), significant enhancement in Nusselt number is noticed. This novel work may be beneficial for nanotechnology and relevant nanocomponents.</p> </abstract>

Magnetized Tri-hybrid Nanofluids flow with binary Chemical Reaction and activation Energy through the porous Surfaces

Hybrid nanofluids are important to researchers because of their industrial applications due to their high heat transfer rates. Tri hybrid different types of nanoparticles are discussed here with Newtonian fluids under the effect of MHD. The most important chemical reaction associated with mass transfer and activation energy parameters hasbeen discussed in detail. The current research focuses on two-dimensional fluids with heat transfer enhancement flowing over a porous surface. The mathematical modeling of the problem, as well as empirical relations for nanoparticle materials, is expressed as PDEs, which are then translated into ODEs using appropriate variables. The Runge–Kutta and shooting methods are combined to solve the problems of the created coupled differential system. Variations in nanoparticle volume fraction at the lower and upper walls of porous plates, as well as heat transfer rate measurements, are computed using controlling physical factors. The impact of flow-related variables on the axial, radial, and temperature components of velocity and temperature distribution is also assessed.

Introducing oxygen transfer rate measurements as a novel method for time-resolved cytotoxicity assessment in shake flasks

BackgroundDetermining the cytotoxicity of test substances is essential for the safety assessment of chemicals. To quantify the cytotoxicity, dose–response curves are determined and the half-maximum inhibitory concentration (IC50) is subsequently calculated. Results often rely on a single endpoint evaluation which typically requires manual sampling and subsequent sample analysis to determine the IC50. Hence, no information on culture behavior are available during treatment. Here, measurement of the oxygen transfer rate (OTR) was applied as a method for time-resolved assessment of the cytotoxicity to (a) provide information on culture behavior during treatment and (b) quantitatively assess the cytotoxic effect of a test substance.ResultsTo investigate the applicability of the method, different types and concentrations of test substances were added and the OTR was measured for two different CHO suspension cell lines in shake flasks: (a) For CHO cell line one, culture behavior was not affected when 0.1 mM ZnCl2 was added. However, for both cell lines, adding up to 0.2 mM CoCl2 led to a decrease in the OTR that was concentration dependent. For CHO cell line two, adding up to 5% DMSO led to a concentration-dependent decrease in the OTR and in the slope of the OTR; (b) From the measured OTR, dose–response curves were established and used to calculate the IC50. For cell line one, the IC50 for CoCl2 was 0.03 mM while the IC50 from a comparative measurement based on trypan blue exclusion was 0.06 mM. Cell line two was less susceptible to CoCl2 as the IC50 was not reached at the concentrations tested. For DMSO, single OTR values and determined slopes were used for evaluation. In both cases, the IC50 was calculated to 2.3%.ConclusionsOur approach provides a method for analyzing the cytotoxicity of a test substance based on OTR measurements. This method provides (i) insights on culture behavior, (ii) information on the progression of cytotoxicity, (iii) dose–response curves, and (iv) a first indication of IC50 values. Quantitative assessment of cytotoxicity is possible non-invasively and in real-time during treatment. Compared to traditional endpoint evaluation, our method simplifies experimentations and enhances the comparison of assay results.

Insight into Dynamic of Mono and Hybrid Nanofluids Subject to Binary Chemical Reaction, Activation Energy, and Magnetic Field through the Porous Surfaces

The mathematical modeling of the activation energy and binary chemical reaction system with six distinct types of nanoparticles, along with the magnetohydrodynamic effect, is studied in this paper. Different types of hybrid nanofluids flowing over porous surfaces with heat and mass transfer aspects are examined here. The empirical relations for nanoparticle materials associated with thermophysical properties are expressed as partial differential equations, which are then interpreted into ordinary differential expressions using appropriate variables. The initial shooting method converts the boundary condition into the initial condition with an appropriate guess and finally finds out an accurate numerical solution by using the Runge–Kutta method with numerical stability. Variations in nanoparticle volume fraction at the lower and upper walls of porous surfaces, as well as the heat transfer rate measurements, are computed using the controlling physical factors. The effects of the flow-related variables on the axial velocity, radial velocity, temperature, and concentration profile dispersion are also investigated. The Permeable Reynolds number is directly proportional to the regression parameter. The injection/suction phenomenon associated with the expanding/contracting cases, respectively, have been described with engineering parameters. The hybrid nanoparticle volume fraction (1–5%) has a significant effect on the thermal system and radial velocity.

Onset of instabilities in rotating flows by direct numerical simulation

A rotating disk is the canonical experiment for measuring surface reaction rates in geochemical and electrochemical systems. Using the similarity solution for laminar flow around an infinite disk, the mass transfer coefficient can be simply related to the intrinsic reaction rate at the surface. However, measurements of mass transfer rates use a finite-size disk within a larger container of solution; here the flow is no longer strictly laminar, but there must always be some recirculation. Our interest was initially in the assumption of a uniform radial concentration field, how this breaks down near the perimeter of the disk, and what effect that might have on the measured mass transfer rates. However, our numerical simulations suggest that the flow around a finite-size disk becomes time dependent at Reynolds number ( $Re$ ) below 1000, which is much smaller than the typical values in mass-transfer measurements ( ${Re} \sim 10^4$ ). We observe the formation of coherent structures in the flow, which suggest a non-uniform mass transfer at the disk surface. The rotating-disk flow follows a similar sequence of instabilities to the Taylor–Couette flow: a centrifugal instability leading an axisymmetric, time-invariant flow, followed by a Hopf bifurcation to a time-periodic flow. To minimise the possibility that our results are a numerical artefact, we have also simulated the instability in the stationary boundary layer of a rotor–stator flow, comparing with self-similar solutions at low ${Re}$ and with spectral methods near the critical Reynolds number.

Non-invasive and time-resolved measurement of the respiration activity of Chinese hamster ovary cells enables prediction of key culture parameters in shake flasks.

Shake flasks are frequently used for mammalian cell suspension cultures. For process development and routine culture monitoring, information on culture behavior is needed early on. Here, cell-specific oxygen uptake rates (qO2 ) of two CHO cell lines were determined from shake flask experiments by simultaneous measurement of oxygen transfer rates (OTR) and viable cell concentrations (VCC). For cell line one, qO2 decreased from 2.38·10-10 to 1.02·10-10 mmol cell-1 h-1 during batch growth. For cell line two, qO2 was constant (1.90·10-10 mmol h-1 ). Determined qO2 values were used to calculate the VCC from OTR data. Cumulated oxygen consumption and glucose consumption were correlated for both cell lines and enabled calculation of glucose concentrations from OTR data. IgG producing cell line one had an oxygen demand of ∼15 mmoloxygen gglucose -1 , cell line two consumed ∼5 mmoloxygen gglucose -1 . The established correlations for determination of VCC and glucose were successfully transferred to subsequent cultivations for both cell lines. Combined measurement of the OTR and the carbon dioxide transfer rate enabled quantitative determination of the lactate concentration (production and consumption) without sampling. Taken together, non-invasive measurement of the respiration activity enabled time-resolved determination of key culture parameters for increased process understanding in shake flasks.

Dynamic electrochemical impedance spectroscopy for the charge transfer rate measurement of the ferro/ferricyanide redox couple on gold

• Rate coefficients of charge transfer are determined by dynamic EIS. • Rate coefficients are presented in a 0.2 V broad range. • By using dEIS, it is easier to preserve cleanliness of the system. • No a priori assumptions on potential dependences of rates are involved. The use of dynamic electrochemical impedance spectroscopy, dEIS is shown in the context of diffusion-controlled electrode reactions. By this method, a number of audio-frequency impedance spectra were measured on a gold electrode in an aqueous solution of K 4 [Fe(CN) 6 ] while taking cyclic voltammograms (the CVs were taken with 50–200 mV/s scan-rate; the distance of potentials of impedance spectra was 16 mV). The Faradaic impedance elements were determined from the spectra, from them charge transfer rate coefficients were calculated; it was found to be 0.11 cm/s at the formal potential. This set of measurements demonstrates the main advantage of dEIS over the traditional steady state impedance measurements: dEIS characterization of an electrochemical system can be performed in seconds rather than minutes which makes possible to use freshly prepared (e.g., annealed) electrodes with reduced risk of contamination or modification of their surfaces.

Validation studies to assist in the development of scale and system independent CFD models for industrial bubble columns

Due to their widespread application there is substantial academic and industrial interest in modelling the hydrodynamics of bubble columns. To this end there is a need to develop and validate modelling approaches which are capable of being applied to industrial systems. In this paper we describe a model which is in good agreement with experimental data across a wide range of scales (columns from 0.19 to 3 m in diameter) and superficial velocities (0.03 to 0.25 m s–1). We have also developed an approach to account for the presence of surface-active compounds, which are frequently present in the liquid phase of industrial processes (e.g., water treatment or fermentation). Using this approach, it is possible to obtain computational predictions in good agreement with experimental measurements of hydrodynamic parameters (e.g., the overall hold-up) and oxygen transfer rates. Finally, to enable the validation work of others a substantial experimental dataset has been included with this work, and areas in need of further investigation have been highlighted.

Casting of Ferroalloys

Casting of ferroalloys is a part of the production process that has been somewhat outdated compared to the preceding reduction and refining processing part of the manufacturing process. Layer casting and chill mold casting have been the dominant types of casting processes even if casting on cast iron plates, water-cooled copper and granulation has gained a certain, but moderate volume. Elkem took the initiative to explore a Direct Strip Casting (DSC) type of process. Measurements of heat transfer rates related to different substrate materials, introductory laboratory scale casting in order of studying material structures and properties, and full-scale experimental casting of 65 % FeSi alloy was performed. One main reason for changing the casting process is the environmental issue. The DSC method seems also to represent an economic advantage over traditional methods.

Direct Measurement of Electron Transfer Rates between Iron(II) Phthalocyanine and Gold with Different Interface Structures

Electron transfer in a metal/molecule system has been extensively studied using various methods. In particular, the relation between the structure of metal/molecule junctions and the electron transfer property is of great interest in the research field of molecular devices. In this study, we measured electron transfer rates of iron(II) phthalocyanine/gold system with different junctions to study the contribution of the atomistic interfacial structures to the electron transfer characteristics.An Au single-crystal disk with (111) or (100) orientation was modified with self-assembled monolayers of imidazole-terminated alkanethiols with the alkyl chain of ten carbon atoms (ImC10SH). Then, iron(II) phthalocyanine (FePc) complexes were attached on top of the monolayer through the axial ligation of the central Fe ions with the imidazole groups. The Au-S bonding structure was measured using Surface-enhanced Raman spectroscopy (SERS).1) The electron transfer rate between Au and FePc was measured by analyzing the cyclic voltammogram (CV) of redox behavior for FePc in 0.1 M perchloric acid aqueous solution.SERS measurements showed that the Au-S bonding structures were different between Au(111) and Au(100). According to the peak position of nAu-S, the dominant Au-S structure was determined to be three-fold hollow geometry on Au(111) and two-fold bridge geometry on Au(100). Figure shows the scan rate dependence of CVs of FePc/ImC10SH/Au(100) and FePc/ImC10SH/Au(111). With increasing the scan rate, the peak separation between the oxidation and reduction peaks became larger in both cases. However, the magnitude of the separation was larger for Au(111) than for Au(100), suggesting that the electron transfer through the Au-S junction was slower at the hollow site on Au(111) than at the bridge site on Au(100). The electron transfer rate can be calculated from the relation between the peak separation and the scan rate. We will present detailed quantitative analysis of the electron transfer rate for different Au-S bond structures, alkyl chain lengths, etc.1) M. Inagaki, K. Motobayashi, K, Ikeda, J. Phys. Chem. Lett., 8, 4236 (2017)Figure. Scan rate dependence of CVs of FePc/ImC10SH/Au(100) and, FePc/ImC10SH/Au(111) in 0.1 M perchloric acid aqueous solution. Figure 1

Auto-Aspirated DAF Sparger Study on Flow Hydrodynamics, Bubble Generation and Aeration Efficiency

A novel auto-aspirated sparger is examined experimentally in a closed-loop reactor (CLR) at lab scale using particle image velocimetry, high-speed camera and oxygen mass transfer rate measurements. State-of-the-art 3D printing technology was utilized to develop the sparger design in stainless steel. An insignificant change in the bubble size distribution was observed along the aerated flow, proving the existence of a low coalescence rate in the constraint domain of the CLR pipeline. The studied sparger created macrobubbles evenly dispersed in space. In pure water, the produced bubble size distribution from 190 to 2500 μm is controlled by liquid flow rate. The bubble size dynamics exhibited a power-law function of water flow rate approaching a stable minimum bubble size, which was attributed to the ratio of the fast-growing energy of the bubble surface tension over the kinetic energy of the stream. Potentially, the stream energy can efficiently disperse higher gas flow rates. The oxygen transfer rate was rapid and depended on the water flow rate. The aeration efficiency below 0.4 kW/m3 was superior to the commonly used aerating apparatuses tested at lab scale. The efficient gas dissolution technology has potential in water treatment and carbon capture processes applications.

Systematic Quantification of Electron Transfer in a Bare Phospholipid Membrane Using Nitroxide-Labeled Stearic Acids: Distance Dependence, Kinetics, and Activation Parameters.

In this report, we present a method to characterize the kinetics of electron transfer across the bilayer of a unilamellar liposome composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine. The method utilizes synthetic phospholipids containing noninvasive nitroxide spin labels having the >N–O• moiety at well-defined distances from the outer surface of the liposome to serve as reporters for their local environment and, at the same time, permit measurement of the kinetics of electron transfer. We used 5-doxyl and 16-doxyl stearic acids. The paramagnetic >N–O• moiety is photo-oxidized to the corresponding diamagnetic oxoammonium cation by a ruthenium electron acceptor formed in the solution. Electron transfer is monitored by three independent spectroscopic methods: by both steady-state and time-resolved electron paramagnetic resonance and by optical spectroscopy. These techniques allowed us to differentiate between the electron transfer rates of nitroxides located in the outer leaflet of the phospholipid bilayer and of those located in the inner leaflet. Measurement of electron transfer rates as a function of temperature revealed a low-activation barrier (ΔG‡ ∼ 40 kJ/mol) that supports a tunneling mechanism.

Heat transfer rate and surface pressure measurements in short duration hypersonic flow

ABSTRACTExperiments were carried out with air as the test gas to obtain the surface convective heating rate and surface pressure distribution on blunt and sharp cone models flying at hypersonic speeds. Tests were performed in a hypersonic shock tunnel at two different angles of attack: ${0}^\circ$ and ${5}^\circ$ with angles of rotation $\phi = {0}^\circ, {90}^\circ$, and ${180}^\circ$. The experiments were conducted at a stagnation enthalpy of 1.4MJ/kg, flow Mach number of 6.56 and free stream Reynolds number based on the model length of $9.1 \times {10}^{5}$. The effective test time of the shock tunnel is 3ms. The results obtained for cone model with a bluntness ratio of 0.2 were compared with sharp cone models for $\alpha ={0}^\circ$. The measured stagnation heat transfer value matched well with the theoretical value predicted by the Fay and Riddell correlation and with the CFD results.

Microelectrode Based Devices for Diagnosis of Electron Transport and Electrochemical Behavior of Redox-Conducting Materials

We are going to address practical issues related to the principles and analytical aspects of electrochemical studies (typically done at room temperature) of solid, rigid or semi-rigid (nonfluid) systems in the absence of a liquid solution phase. Representative examples include redox and conducting organic polymers, melts and solid solutions of redox centers in solid ionic conductors, mixed-valence polynuclear inorganic materials, transition metal salts, oxides, and zeolites. The emphasis is on the elements of dynamics for the efficient delivery of charge and on reactivity of the ‘redox conducting’ materials. The effective (apparent) diffusional mechanism is critical to the success of most analytical measurements in solid-state. Historically, electrochemistry in the absence of a bulk liquid phase has focused on the problems of energy storage and production. Recently, it has become possible to apply conventional electrochemical methods to characterize solid-state type redox electrolytes with respect to analytical characterization of materials, measurement of electron transfer rates, and determination of analytes using amperometric sensing. The characterization of materials by solid-state voltammetry primarily has focused on mixed-valence, ionically conducting compounds and on diverse organic ionomers hosting identifiable molecular (redox) sites. Potential materials for solid-state electrochemical measurements are expected to contain three-dimensionally distributed highly concentrated redox centers between which fast electron self-exchange (hopping) is feasible. Among inorganic systems, single crystals of heteropolyacids of molybdenum and tungsten, as well thin films of Prussian Blue type metal hexacyanoferrates will be considered. These redox centers are fixed and, although they may have short range mobility about an equilibrium position, they classically are macroscopically immobile. The applicable materials also must host mobile counter-ions that are capable of providing charge balance during electron transfers, thereby serving the same purpose as the supporting electrolytes in conventional electrochemistry. The population of these ions must be sufficient to support diffusive mass transport of electrons and to minimize ohmic effects. We will describe typical electrochemical cells and experimental tactics to overcome the relatively slow dynamics of transport in solid (non-fluid) systems. Application of microdimensional electrodes leads to an improvement in the quality of solid-state electrochemical data and provides new diagnostic and analytical possibilities. Basic concepts of mechanistic studies, which are relevant to the development of novel analytical methods, together with trends towards possible future applications will also be addressed.