Travis J. Moore

A Method of Measuring the Properties of Ash Deposits in a Coal Fired Reactor

Coal is an important source of energy because of its potential for power generation and its abundance in the earth. A great deal of research is dedicated to developing cleaner and more efficient methods of generating power from coal. A major problem associated with almost all power generation processes involving coal is the formation of ash. Some of the ash that is formed is deposited on the tubes and walls of the combustion chambers. This accumulation of ash can significantly affect the thermal transport in the boiler. Modeling of the heat transfer occurring in a coal combustion process requires knowledge of the properties of these deposits. Accurate measurements of these properties will lead to better modeling capabilities and improved optimization of the design of coal fired reactors. Therefore, a method for accurate, in situ measurement of the emittance and thermal conductivity is highly desirable. This paper describes the development of a method for determining the total emittance and thermal conductivity of the deposited ash layers and analyzes the sensitivity of these properties to measurement errors.Copyright

Experimental measurements of the spectral absorption coefficient of pure fused silica optical fibers

Knowledge of the spectral absorption coefficient of fused silica optical fibers is important in modeling heat transfer in the processes and applications in which these fibers are used. An experimental method used to measure the spectral absorption coefficient of optical fibers is presented. Radiative energy from a blackbody radiator set at different temperatures is directed through the optical fibers and into an FTIR spectrometer. Spectral instrument response functions are calculated for different fiber lengths. The ratios of the slopes of the instrument response functions for the different lengths of fibers are used to solve for the spectral absorption coefficient of the fibers. The spectral absorption coefficient of low OH pure fused silica optical fibers is measured between the wavelengths 1.5 and 2.5 μm.

Loving God, Loving Others: The Sacred Among American Mainline Protestant Families

Abstract Quantitative research suggests a link between religion and increased relationship commitment, satisfaction, and quality in marriages and parenting. Less is known about the processes and meaning-making experiences of religious individuals and families and how or why such processes exist and function with a family context. Using in-depth qualitative interviews, 20 Mainline Protestant families (N = 47 individuals; 20 mothers, 20 fathers, and 7 youth) were examined. Major findings revealed that intra-personal sanctification (i.e., sacred relationship with God) influenced inter-personal sanctification (i.e., sacred relationships with others), across three domains: general life strengths, as well as marital and parent-child strengths. Additional findings suggested that sacred beliefs and religious practices were utilized for receiving support from God, a framework of purpose, increased unity between spouses and parent–child dyads.

“The prayers of others helped”: Intercessory prayer as a source of coping and resilience in Christian African American families

ABSTRACT Married African American families are perceived as highly religious; however, they are often underrepresented in research studies involving prayer. This study used qualitative interviews to examine intercessory prayer as a perceived source of strength and resilience for 33 heterosexual, highly religious African American families identifying as Christian. Data were analyzed using open coding and Numeric Content Analysis. The following themes were identified: (a) Interceding Prayers Build Personal Strength, (b) Interceding Prayers Strengthen Marital Bonds, and (c) Interceding Prayers Unite Communities. Narratives are offered to support each theme and social work implications are discussed.

In Situ Characterization of Coal Ash Thermal Conductivity Under Oxidizing and Reducing Conditions

This work presents in situ measurements of the effective thermal conductivity in particulate coal ash deposits under both reducing and oxidizing environments. Laboratory experiments generated deposits on an instrumented deposition probe of loosely-bound particulate ash from three coals generated in a down-fired flow reactor with optical access. An approach is presented for making in situ measurements of the temperature difference across the ash deposits, the thickness of the deposits, and the total heat transfer rate through the ash deposits. Using this approach, the effective thermal conductivity was determined for coal ash deposits formed under oxidizing and reducing conditions. Three coals were tested under oxidizing conditions: two bituminous coals derived from the Illinois #6 basin and a subbituminous Powder River Basin coal. The subbituminous coal exhibited the lowest range of effective thermal conductivities (0.05–0.18 W/m· K) while the Illinois #6 coals showed higher effective thermal conductivities (0.2–0.5 W/m· K). One of the bituminous coals and the subbituminous coal were also tested under reducing conditions. A comparison of the ash deposits from these two coals showed no discernible difference in the effective thermal conductivity based on stoichiometry. All experiments indicated an increase in effective thermal conductivity with deposit thickness, probably associated with deposit sintering.Copyright

A Method of Measuring the Temperature Profile of a Thermal Barrier Coating Using Inverse Radiative Heat Transfer Methods

Ceramic thermal barrier coatings (TBCs) are used in power generation and aerospace turbines to protect superalloy components from large and extended heat loads. These coatings allow for increased inlet temperatures, thereby increasing efficiency and reducing air cooling requirements. Knowledge of the temperature profile in a thermal barrier coating is critical for evaluating the TBC performance and monitoring its health, as well as for accurate simulation and modeling. Non-contact, non-destructive techniques for finding these temperature profiles are highly desirable. Current techniques are limited in that they cannot measure the entire temperature profile of the TBC along with its radiative properties. An inverse radiative heat transfer method capable of determining the temperature profile, as well as the spectral absorption coefficient and spectral emittance at various wavenumbers, of a TBC using non-contact techniques was developed. A model of the measurements of the intensity exiting the TBC, which account for the emission from the substrate as well as the emission and absorption of the TBC itself, was developed. The TBC was approximated as a one-dimensional, plane-parallel, non-scattering medium. Optimization methods were used to determine the desired parameters by minimizing the error between actual intensity measurements and those calculated from the model. This method was tested for a number of simulated measurements with and without measurement error. Even with 10% measurement error introduced, the base temperature of the TBC was determined with only 0.45% error while the error in the TBC surface temperature measurement was 3.36% and that in the spectral emittance of the bondcoat was 12%. The error in the spectral absorption coefficient was significant.Copyright

An Experimental Method for Making In Situ Spectral Emittance Measurements of Coal Ash Deposits

An experimental procedure has been developed to make in situ spectral emittance measurements of coal ash deposits. Pulverized coal is injected into a down-fired, entrained-flow reactor. Ash accumulates on a probe placed in the reactor effluent. The spectral emittance of the ash layer is calculated using measurements of the surface temperature and the spectral emissive power of the deposit. Measurements of the spectral emissive power and the surface temperature are obtained using a Fourier transform infrared (FTIR) spectrometer. The methods used to extract the spectral emissive power and surface temperature from measured infrared spectra were validated using a blackbody radiator at known temperatures. The experimental procedure was then used to find the spectral emittance of a coal ash deposit formed under oxidizing conditions.Copyright

Reduced Order Modeling of Light Scattering by a Cloud of Particles

It is often desirable to unobtrusively determine physical characteristics of a cloud of particles. Measurements of the radiation scattered by the cloud contain information regarding properties such as refractive index of the particles, the volume fraction of the particles and the number density of the particles. Inference of these properties from light scattering measurements requires the solution of an ‘inverse problem’. Methods for solving this type of inverse problem often require the repeated solution of the associated forward problem. Therefore, techniques capable of reducing the computational requirements of the forward problem are of interest.Copyright