The present paper considers the thermal force in the thin film layer after expansion/contraction and to estimate the maximum thermal force in the layer. As an analytical model of the deposited layer, the layer are assumed to be a chain f circular particles and each particle is adhered to the neighboring ones with a flat wall. In order to estimate the thermal force in a single particle that has two flat wall boundaries, a linear thermo-elastic analysis for the particle is carried out. The standard thermo-elastic technique for the dual series is applied to the particle with mixed boundary conditions and then approximate expressions for the contact stress and the thermal expansion force are obtained.

View full abstract

This paper deals with the axisymmetric three-dimensional generalized thermoelasticity based on the Lord and Shulman's theory and the Green and Lindsay's theory by use of the state space approach. The fundamental equations of generalized thermoelasticity, which include both generalized theories, are used. The generalized thermoelastic problem for a layered medium, which consists of homogeneous and isotropic layers and whose surface is traction free and subjected to an axisymmetric heating is analyzed by means of the Laplace and Hankel transforms. The inversions are carried out numerically. The numerical calculations for temperature and stresses under the generalized formulation are carried out.

View full abstract

This paper is concerned with the theoretical analysis of the transient piezoelectro-magneto thermoelastic problem of multi-layeded composite strip constructed of piezoelectric and magnetostrictive materials due to nonuniform heat supply in the width direction. We obtain the exact solution for the two-dimensional temperature change in a transient state, and transient piezoelectro-magneto thermoelastic response of a simply supported composite strip under a plane strain state. As an example, numerical calculations are carried out for a 2-layered composite strip and the numerical results are shown in figures.

View full abstract

In the present article a theoretical treatment of magnetothermoelastic stresses and deformations is dealt with in a conducting solid circular cylinder subjected to both internal heat generation due to eddy current loss and Lorentz force by a cyclic variation in time of magnetic field. We assume that a uniform magnetic field whose intensity varies sinusoidally in time acts on the cylinder in a direction parallel to its surface. First, a plane axisymmetrical magnetic field and the associated eddy current in the cylinder due to electromagnetic induction are formulated based on the theory of quasi-stationary electromagnetic field. Next, magnetothermoelastic stresses and deformations in a conducting solid cylinder which is subjected to both a plane axisymmetrical temperature change due to eddy current loss and the Lorentz force are analyzed under the generalized plane strain condition. Finally, we carry out numerical calculations and examine an effect of the frequency in cyclic variation of magnetic field on the electro-magnetic field, current density, temperature change and magnetothermoelastic stress and deformation in the cylinder.

View full abstract

Recent decade, atomistic simulations, such as molecular dynamics and Monte Carlo method, have been developed with help of computation power. In the present paper, typical applications of atomistic simulation to fatigue fracture are reviewed. Some direct simulations for fatigue phenomena are successful, but most researches are focused to its fundamental processes. It is pointed out that such basic calculation can be applicable to multi-scale simulations in engineering level with linking discrete dislocation dynamics and macroscopic cohesive zone model and so on. Future trends in study of fracture from atomistic simulation are expected and discussed.

View full abstract

The crack propagation behavior of PVC and GFRP in the fatigue test was evaluated by probabilistic fracture mechanics each material by Probabilistic fracture mechanics. The probability characteristics of the initial crack length a_o, and the parameters, m and C, in Paris rule m and C by investigated and the relation of da/dN-ΔK for each material was obtained Based on the relation, the prospective curves of P-da/dN-ΔK and P-S-N curves were obtained, and compared with the experimental results. Probabilistic fracture mechanics is one of the effective methods in life prediction of polymer based materials.

View full abstract

Dislocation structures of fatigued copper single crystals and stainless steel polycrystals are nondestructively observed by electron channeling contrast imaging (ECCI) method. The ECCI method enables us to detect dislocations underlying near surface of a bulk crystal, using a scanning electron microscopes. Ladder-like dislocation patterns formed along primary slip planes are successfully observed in a single-slip-oriented copper single crystal by the ECCI method. Because this structure is almost same as observations with transmission electron microscope (TEM), it is said that the ECCI method can replace the conventional TEM observation at least in examining the dislocation structure of fatigued metals. Development of dislocation structure during fatigue is also investigated in one specimen of the stainless steel polycrystal.

View full abstract

Since fatigue crack growth phenomenon is considered to be intrinsically localized, microscopical observation is an effective technique to elucidate the fatigue crack growth mechanism. In this study, fatigue crack growth behavior in low ΔK region was observed by means of an atomic force microscope (AFM) and crack deflection mechanism was discussed.

View full abstract

The discrete dislocation (DD) method is one of mesoscopic scale computer simulation procedures which can deal with both the crack and dislocations. In this paper, each dislocation movements and stress field near a fatigue crack tip under mixed mode condition, Mode I and II, were investigated by means of the 2-dimensional DD analysis. The material analyzed was an iron with bcc structure which has two preferred slip direction, and the fatigue crack was assumed to progress along one of two slips. The quantity of the crack plane deformation along the crack growth direction was found to become smaller as crack growth due to the constraint of slip deformation by grain boundary, and then to be exceeded one along the other slip plane direction. The crack kinking behavior which has been observed experimentally can be well simulated by using the model that the crack kinks when this excess occurs.

View full abstract

This study was conducted to consider the fatigue strength of materials with surface layers based upon the force applied to dislocations. For this purpose, we investigated the values of the force due to the externally applied stress and the image force acting on a screw dislocation in the semi-infinite elastic body with the surface layer whose shear modulus is different from that of the substrate. The image force was derived using the concept of image dislocations. The result of the analysis predicted that the shear modulus lower than that of the substrate is desirable to suppress the movement of dislocations escaping from the surface without the increase in the possibility of fracture of the surface layer due to the generation of high stress in the layer.

View full abstract

Molecular dynamics (MD) was applied to the simulation of near-threshold fatigue crack propagation. Fatigue crack propagation was analyzed for various values of ratio γ of mode II and mode I stress intensity ranges. Crack propagation direction changed with γ. The crack propagation direction in MD simulation agreed well with that predicted using the Δσ maximum criterion.

View full abstract

Means of utilizing exhaust heat generated from a microturbine generator by a desiccant air-conditioning unit is compared with means by a wasts heat recovery boiler and a refrigerator recovering exhaust heat directly from flue gas from a economic viewpoint. An optimization approach is adopted to rationally compare between the aforementioned means. On/off status of operation of equipment and energy flow rates are determined so as to minimize the hourly energy change subject to satisfaction of energy demand reqirments. In the optimization problem, performance characteristics of such equipment as the desiccant air-conditioning unit are modeled in consideration of enthalpy, absolute humidity and temperature of ambient air. Through numerical studies carried out on systems installed in an office building and a hospital, the effects of the systems combining the microturbine generator with the desiccant air-conditioning unit on economy is clarified.

View full abstract

Economic, energy-saving and environmental protection feasibilities of solid oxide electrolyte fuel cell(SOFC) and SOFC/microturbine(MT) hybrid cogeneration systems are investigated based on a multiobjective optimization approach. Equipment capacities and maximum contract demands of utilities such as electricity and natural gas are determined so as to minimize the annual total cost, the annual primary energy consumption and the annual CO_2 emission in consideration of operational strategies subject to satisfaction of all the energy demand requirments. The ε-constraint method is adopted as a solution one for the above multiobjective optimization problem. Numerical studies are carried out on SOFC and SOFC/MT hybrid cogeneration systems installed in hotel and a office building by changing the capital unit costs of the SOFC and SOFC/MT cogeneration units. Through the studies, the trade-off relationships between the economic, energy-saving and environmental protection properties are clarified, and it is found that the SOFC/MT hybrid system is excellent from viewpoints of energy-saving and environmental protection properties.

View full abstract

The power generation characteristics of a tubular Solid Oxide Fuel Cell (SOFC) are studied based on a two-dimensional numerical simulation which considers momentum transfer, heat and mass transfer, electrochemical phenomena and equivalent electric circuit. Fuel, which is composed of hydrogen and steam, and air flows are assumed to be steady, laminar and axisymmetric. An activation overpotential model which considers temperature dependency is applied to calculate the local electric current density accurately. As a consequence of this study, details of the power generation characteristics of a cell are obtained. The activation overpotential decreases as the cell temperature increases, and it significantly affects the power generation characteristics.

View full abstract

A new recycling system for waste plastics was developed, in which waste plastic and heavy oil are mixed to produce an alternative fuel for power generation systems. It was found that for the injection of mixture fuel, heating at temperatures around 150℃, was needed for a proper viscosity. In the present study, the emulsification of waste plastic and heavy oil mixtures with water is examined. Using a surfactant, emulsions of polypropylene (PP) with water have been successfully produced and no fuel heating would be necessary.

View full abstract

Experimental study was carried out to reveal evaporation characteristics of emulsion droplet on a hot surface. Detail measurements of onset of micro-explosion and temporal variation of droplet temperature were made for three base fuels at surface temperature of 700 K. The fuel in water emulsions consisting base fuel and water, doped with small amount of surfactant, were tested after degasification. Water coalescence occurred and formation of transparent droplets which surrounded smaller single opaque droplets were observed as in the case for suspended droplet combustion. The waiting times for the onset of micro-explosion were correlated with the Weibull distribution curves and those shape parameter twice of unity. The waiting time became shorter with higher boiling point of base fuel. The droplet thermometry showed that microexplosion occurred during droplet heat-up resulting in the above-mentioned shape parameter.

View full abstract

An experimental study was performed to clarify the flame structure of burning fuel droplet. Fuel employed was mixture of n-heptane and benzen. Both OH radical and soot concentration distributions were measured along the radial direction passing the front stagnation point of a fuel droplet flame in steady air flow. The laser induced fluorescence technique was applied for measurement of OH radical concentration distributions. The laser light scattering technique was applied for measurement of soot concentration distributions. An Nd : YAG laser-pumped pulsed dye laser with frequency doubling was used for these measurements as the light source. The wavelength of the UV light was adjusted to 283.65nm. The results showed that the soot concentration increased with increasing benzen volume concentration, while the OH radical concentration kept almost constant.

View full abstract

An experimental study has been performed to obtain the detail information about the evaporation characteristics of binary mixture droplet on high-temperature wall. Primary attention was mainly paid to clarify the effects of fuel composition on lifetime. Binary fuels tested were composed with 50% n-hexane and 50% straight-chain alkane with higher boiling point. Two peaks in the lifetime curves were observed with both n-decane/n-hexane and n-dodecane/n-hexane binary fuels. The minimum lifetime increased over each pure fuel.

View full abstract

An experimental study has been made of the ignition and combustion of fuel droplets subjected to a laminar flame propagating through a lean fuel-air mixture, as a fundamental study for revealing the combustion phenomena of fuel vapor-air-fuel droplet system. A combustion chamber was installed with spark electrodes, for propagating flame formation near the side wall, and with a quartz fiber for suspending single n-hexane droplet in the chamber center. Schlieren image of the fuel droplet in the propagating flame of lean propane-air mixtures was observed by a high-speed video camera. The results showed that the ignition distance decreased with an increase in initial mixture pressure, and increased with an increase in mixture equivalence ratio. The ignition delay was unaffected by initial mixture pressure.

View full abstract

The experiment was performed to investigate the effect of interaction of the fuel droplets on ignition and flame formation in hot ambience under microgravity. 19 droplets were arranged 2-dimensionally with the same neighboring droplet spacing, and the droplet spacing was varied from 3 to 9mm. The initial diameter of all the droplets was 1mm. n-Hexadecane was used for fuel droplet. A group flame was formed at ignition both with 3mm and 6mm droplet spacing, while an individual flame was formed at ignition and it changed into a group flame with 9mm droplet spacing. Ignition delay and relative flame area increased with decreasing the droplet spacing.

View full abstract

The homogeneous charge compression ignition process was simulated using a VLES code in conjunction with a reduced kinetic model for low temperature oxidation and a one-step global model for hot flame reaction. The calculation result shows that the interaction between turbulence and chemical kinetic process is an important factor to express moderate combustion in HCCI.

View full abstract

The combustion process of natural gas in a premixed charged compression ignition (PCCI) engine is analyzed using computational fluid dynamics included in heterogeneity of mixture concentration and temperature with stochastic approach. The non-uniform states of turbulence mixing, ignition process is statistically described using the probability density functions (PDF). The results show that the course of in-cylinder pressure is good agreement with experimental data and the effect of mixture heterogeneity on the ignition delay and the rate of heat release is revealed.

View full abstract

In premixed compression ignition engines, NOx emission is reduced remarkably under partial load conditions but the engines cannot work under high load conditions. For improving such a defect, a MULDIC (Multiple Stage Diesel Combustion) concept was proposed by New ACE Institute. In a MULDIC engine, the premixed combustion at the first stage and the diffusion combustion at the second stage have to be optimized to realize high output with low NOx emission. In this study, the combustion processes under various injection conditions in a MULDIC engine were numerically analyzed using the authors' GTT code with Schreiber's five-step reduced kinetic model. As a result, the heat release rate and the tendency of NOx emission were predicted reasonably.

View full abstract

An experimental study was performed to investigate the effects of injection conditions on the stability of combustion and the performance in a direct-injection compression-ignition engine fueled with natural gas. Using a single cylinder engine, the data were obtained changing fuel jet angles and injection pressure at three injection timings. The results show that the smaller fuel jet angle and the lower fuel injection pressure lead to higher thermal efficiency and lower unburned-species emissions especially at an injection timing of 60゜BTDC.

View full abstract

To obtain fundamental data for applying direct injection to natural-gas fueled engines, an experimental study was carried out by using a constant volume vessel. Ignition delays, heat release rates and shadowgraph images were acquired for natural-gas jets injected from a single-hole nozzle simulating the change in engine-combustion-control factors : ambient temperature, oxygen mole fraction and fuel-injection conditions. The results show the ignition delay and heat release rate are sensitive to injection and ambient conditions. Higher injection pressure leads to longer ignition delays contrary to diesel sprays. The ignition delay increased with decreasing oxygen mole fraction.

View full abstract

Experiments were performed to investigate effects of fuel velocity fluctuation on combustion behavior of diffusion a jet flame. The fuel employed was methane. Periodic fuel supply was realized using an electromagnetic valve of quick-response type and damper. By utilizing the microgravity conditions, the flame behavior affected by the fuel supply fluctuation was clearly observed. The tip of the flame departed from main part under higher conditions of mean fuel velocity, amplitude ratio of fuel velocity fluctuation and its frequency. The normalized variation of the flame length showed a maximum around the frequency of 5Hz, and decreased with increasing the frequency from 5Hz. The effect of mean fuel velocity on the normalized flame length variation was less remarkable under microgravity.

View full abstract

The mixing of hydrogen into natural-gas fuel in an SI engine extends the lean limit and promotes the combustion, but at the same time easily causes a hard knock. In this study. pressure histories and thermal efficiencies were measured with a single-cylinder test engine for various engine parameters such as equivalence ratio, ratio of hydrogen to natural-gas fuel, ignition timing, and compression ratio. Based on the experimental results, the knock characteristics were discussed with special attention to the extremely high burning velocity.

View full abstract

Fractal dimension analysis for wrinkled flame structure during early phase of flame development was conducted. The test engine was operated at various speeds and compression ratios. The empirical model expressing the growing nature of the fractal dimension was derived from the data set of the fractal dimensions in time-series over many cycles. The model constants were correlated with turbulence intensity, ambient pressure and the expansion ratio of unburned gas density to burned gas density.

View full abstract

In order to clarify the effects of injection conditions and oxygen mole fraction on ignition delays in fuel sprays, and experimental study was conducted by using a constant volume vessel. Ignition delays were obtained at various ambient temperatures, pressures and oxygen mole fraction in n-heptane sprays. The results show that the hot-flame delay increases with the decrease in oxygen mole fraction. The hot-flame delay increases with the decreasing nozzle orifice diameter at a low oxygen mole fraction and a low ambient pressure.

View full abstract

In DI diesel engines, atomization and evaporation of fuel sprays greatly affects the engine performance and pollutant emissions. In this study, atomization and evaporation process of diesel sprays injected into a high-pressure and temperature inert gas atmosphere made by a RCM were investigated using a magnified nanosecond photography method. Using this technique, the authors were able to clearly observe the large size vortical structures at downstream of spray. The results show that spray evaporation is very active around these vortical structures.

View full abstract

Including early injection timings, the effects of pilot injection on combustion and exhaust emissions were investigated in a DI diesel engine. With adequate pilot injection quantity and short pilot-main interval, NOx and noise are reduced suppressing the increase in Smoke. But early-timing pilot and high-pressure injection cause the increase in THC. At a light load, pilot injection is useful for stabilizing combustion.

View full abstract

In diesel engines, increasing exhaust gas recirculation EGR ration promotes NOx reduction but gives an increase in PM emission. Diluting engine intake air with CO_2 (CO_2 selective EGR) extends the EGR ratio window with no PM increase. Nevertheless, extraction of CO_2 from diesel exhaust is not easy due to the moisture existence, which diminishes the CO_2 adsorption efficiency of conventional absorbents such as zeolites. In this study, CO_2 was chemically adsorbed using potassium carbonate K_2CO_3-on-Carbon by the reaction K_2CO_3+CO_2+H_2O⇔2KHCO_3. Then, entrapped CO_2 was released by decomposition of KHCO_3 by steam flushing which reverses the mentioned reaction. This method offers a high CO_2 extraction efficiency even when gas contains a high amount of moisture.

View full abstract

As to three-way catalyzers (TWC) for automobile exhaust gas, further reduction of exhaust emissions in demanded, and therefore it is necessary to optimize the conversion characteristics, geometry and installation position of the catalyzer. For such a purpose, the authors are planning to carry out three-dimensional numerical simulation of heat, flow and gas composition in a TWC. As a first step in this study, the authors have created a detailed analytical model for thermo-fluid with chemical reaction in a TWC and carried out a fundamental examination.

View full abstract

Heat recovery performance of ceramic honeycomb is in practical use at "High Performance Industrial Furnace". The other hand this waste gas cooler is developed using the highly cooling performance of a ceramic honeycomb. The waste gas of waste incinerator reaches 800 degrees C or more, and needs to be dropped to 200 degrees C before a dust collector. Usually, waste gas is cooled by water spraying, which causes the many troubles. This new type waste gas cooler can "Instant cooling" and "Dry cooling" and solve these troubles caused by water splaying. This paper describes development efflux, the scheme, and the earmark of this apparatus.

View full abstract

Neighboring Communities Generation (NCG) System is created to present the comfortable and high quality living environment, using combined heat and power (CHP) technologies. The key concept of this system is to connect the home and home for one loop of heat transfer line and level or manage the demand of heat consumption in the small community with high internet practice. This system is expected to optimum the heat utilization and to aim the higher efficiency than stand alone of the distributed generation system. And further expectation for the system is that this system will contribute to save energy, which is equivalent to abate over 50% of CO2 emission from homes due to the higher efficiency of CHP. In urban area of Kinki area, approximate 55% inhabitants live in condominium. Then introduction of the system will be expected to be able to contribute to achieve CO2 abatement target for the Kyoto protocol. This system will also increase the availability of the co-generation system and improve the heat use management. For the realization of this system, the study group is established in AIST Kanasi Center recently and the combination technologies of heat supply, heat storage and air conditioning are under development besides the Information Technologies (IT) application. This paper describes the new idea of energy supply system with participation of inhabitants for the energy network system.

View full abstract

In Singapore the ERP (Electronic Road Pricing) system has operated since 1998. We supplied this system, which aims to restrict traffic volume entering into urban area using radio communication technology. And this system became the basic infrastructure, and almost all vehicles in Singapore are equipping with IU (In Vehicle Unit). Now, we have developmend the EPS (Electronic Parking System), which uses IU and the ERP technology.

View full abstract

Three unique developments by Hitachi Zosen nano-technology are introduced in this paper. The first development is the elasticity grindstone of elastomer type. It succeeds in high performance for mirror surface grinding. The second one is a 10×7(mm)^2 view sized X-ray interferometer which is made of Silicon. By using our developed mirror processing technology, large view sized X-ray interferometer is able to produce. The last one is conductive carbon-nanotubes sheet (CCNS). It succeeds in arranging carbon nanotubes on conductive film seat. We have been advancing these developments for the industrial use as realization.

View full abstract

Mechanical elements under high surface pressure that accompanies abrupt acceleration or deceleration and/or increases in load can easily en in a lubrication state close to dry friction. In this condition, the lubricating oil needs addition of some EP (Extreme Pressure) additives, such as Cl-additives, P-additives, S-additives and their blended-Additives which have been used as typical EP additives. Generally speaking, sulphur type additives have most scaffing resistance in these additives, and phosphorus type additives and Chlorine type additives are next to that. And sulphur type additives have wear durability that is inferior to phosphorus type additives. In our experiment, wear durability of sulphur type additives in our step loads under high pressure for steel to steel contact was investigated by using a four-ball tester.

View full abstract

This paper describes an experimental study on the effect of texturing on tribological characteristics of metal surfaces under lubricated sliding contact. START-STOP repetition test and scuffing test were carried out by using slider-disc test machine. An experiment is done for the slider specimens with grooves parallel to the slide direction. The ratio of the grooving width to land width, and grooving depth were uniformly fixed, and the pitch and width of grooving were varied. The results reveal that fine grooving can lead the surface to run-in quickly and to resist scuffing.

View full abstract

Using a friction tester of ball-on-flat plate type, influence of surface temperature on the boundary lubrication characteristics of mineral lubricating oils was examined. The tester consists of a ball and a flat plate installed an electric heater to control its surface temperature. The sliding speed was slowed down to minimize the frictional heating as well as hydrodynamic pressure generation between the ball and flat plate. The results can be summarized as follows; 1) mineral base oils have transitional temperatures higher than these of oiliness agents, 2) mineral oils added oiliness agents have two kinds of transitional temperature, one of which is due to the agents and the other is due to the base oils, 3) the latter seams to lead to scuffing.

View full abstract

In this study, the surface modification of PC was performed by ion implantation, and friction and wear properties were investigated. Moreover, XPS analysis and surface hardness were examined in order to investigate them. As a result, C-N bonds were formed by ion implantation, and the surface hardness had increased with the optimal accelerating voltage and influence. The frictional coefficient decreased by the ion implantation. Therefore, it was found that the optimal conditions of the accelerating voltage and influence were found in order to improve friction and wear properties, and the usefulness of the ion implantation to PC was clarified.

View full abstract

Aerodynamic foil bearings are applicable to a bearing system for a micro gas turbine in a distributed energy source. To develop such bearings of simple structure that can adjust to severe conditions of high temperature and high-speed rotation, in this study, a tension type foil bearing of new structure is proposed, and its performance is examined experimentally.

View full abstract

In this paper, the contact state between belt and pulley, the load distribution on pulley teeth and the frictional work of curvilinear tooth profile synchronous belt drives are computed by a finite element method. The calculation has been done every one tenth of the belt pitch. The contact between the belt tooth and the pulley tooth at the end of incomplete meshing region on the driven pulley is kept around 1 pitch of the pulley. The tooth load on both the driving and the driven pulleys becomes the maximum at the meshing region which is close to the tight side of the belt.

View full abstract

The jumping characteristics at the driven pulley of L type synchronous belt drives are experimentally and analytically discussed. The number of the driving and the driven pulley teeth is the same and the wrapping angle of the belt on both pulleys is πradian.The simulation of the FEM analysis of the wrapping angle of the belt on the driven pulley is almost the same with the same with the experimental result. FEM analysis of the load distribution at just before jumping on the driven pulley agree well with the experimental results.

View full abstract

CVT has a potential to present comfortable cruising, powerful acceleration, fuel economy and improvement of exhaust-gas emission because it can change a speed ratio continuously and smoothly. Traction drive type CVT attracts attention from the fact that it can load onto also the automobile which has the engine of high output. It is thought that the transfer efficiency of traction drive type CVT, when mechanism and form are locked, influence of traction oil and normal force is received mainly. In this paper, the transfer efficiency when changing traction oil and normal force in the ring corm CVT using 2 K-H was investigated. And it is the purpose to grasp a tendency based on experiment data.

View full abstract

In color printer, automatic ticket gate, automatic teller machine(ATM), the flat belt is used widely. Angular misalignments of cylindrical pulley caused skew of film belt, and influence greatly quality of image in color printer. Characteristics of the film belts skew are clarified the FEM simulation by ABAQUS/Standard as compared with the experimental results. As a result, belt width and shaft road, torque have little effects on skew, but misalignment angle have effect on skew.

View full abstract

The complicated phenomena such as pressure depressions, shock waves and the negative pressure, are detected in the air flow with a large bearing clearance or high supply pressure in an externally pressurized gas-lubricated circular thrust bearing. The pressure depression, which decreases the bearing load capacity, is an undesirable phenomenon occurring in this gas bearing. The non-contacting suspension support of the object with the surface processed by the machine tool (the lathe and the milling machine) utilizing the negative pressure of this gas bearing is investigated experimentally, and is also discussed in this paper.

View full abstract