Experimental investigation of the vibrational and thermal response of a laser spark plug

A study was conducted in order to evaluate the external thermal and vibrational effects on the operation of a laser ignition system for internal combustion (IC) engine applications. West Virginia University (WVU) in conjunction with the National Energy Technology Laboratory (NETL) have constructed a prototype laser spark plug which has been designed to mount directly onto the head of a natural gas engine for the purpose of igniting an air/fuel (A/F) mixture in the engine\u27s combustion chamber. To be considered as a viable replacement for the conventional electrode-based ignition system, integrity, durability and reliability must be justified. Thermal and oscillatory perturbations induced upon the ignition system are major influences that affect laser spark plug (LSP) operation and, therefore, quantifying these effects is necessary to further the advancement and development of this technology.;The passively q-switched Nd:YAG laser was mounted on Bruel & Kjaer (B&K) Vibration Exciter Type 4808 Shaker in conjunction with at B&K Power Amplifier Type 2719, which was oscillated in 10 Hz intervals from 0 to 60 Hz using a sine wave to mimic natural gas engine operation. The input signal simulated the rotational velocity of the engine operating from 0 to 3600 RPM with the laser mounted in three different axial orientations. The laser assembly was wrapped with medium-temperature heat tape, outfitted with thermocouples and heated from room temperature to 140 ºF to simulate the temperatures that the LSP may experience when installed on an engine. The acceleration of the payload was varied between 50% and 100% of the oscillator\u27s maximum allowable acceleration in each mounting orientation resulting in a total of 294 total setpoints.;For each setpoint, pulse width, pulse width variation, q-switch delay, jitter and output energy were measured and recorded. Each of these dependent variables plays a critical role in multi photon ionization and precise control is necessary to limit the variability of these key parameters. Under the influence of thermal and oscillatory perturbations, the q-switch delay of the laser was found to vary significantly. For application on an IC engine, such variation in qswitch delay would result in an ignition timing variation by as much as +/-4.6 crank angle (CA) degrees in the most extreme setpoint on a cycle-to-cycle basis. Every setpoint tested was calculated to be capable of generating a plasma spark in air (\u3e100 GW/cm2), however the resulting focal intensity was found to vary by as much as +/-13 GW/cm2

MI 740 XL Introduction to Christian Mission

Roger E. Hedlund, The Mission of the Church in the World: A Bibical Theology. Grand Rapids, MI: Baker Baker House, 1991. Charles Van Engen, Mission on the Way: Issues in Mission Theology. Grand Rapids, MI: Baker Book House, 1996. J. Herbert Kane, A Concise History of Christian World Mission, Grand Rapids, MI: Baker Book House, 1978. Gailyn Van Rheenen, Missions: Biblical Foundations and Contemporary Strategies. Grand Rapids, MI: Zondervan Publishing Co., 1996. Vincent Donovan, Christianity Rediscovered. Maryknoll, NY: Orbis Books, 1991. Bruce E. Olson, Bruchko. Carol Stream, IL: Creation Press, 1973. James M. Phillips and Robert T. Coote, Toward the 21st Century in Christian Mission, Grand Rapids, MI: Wm. B. Eerdmans, 1993. Darrell Whiteman, Anthropology and Mission: The Incarnational Connection.https://place.asburyseminary.edu/syllabi/2456/thumbnail.jp

MI 740 Introduction to Christian Mission

Roger E. Hedlund, The Mission of the Church in the World: A Bibical Theology. Grand Rapids, MI: Baker Baker House, 1991. Charles Van Engen, Mission on the Way: Issues in Mission Theology. Grand Rapids, MI: Baker Book House, 1996. J. Herbert Kane, A Concise History of Christian World Mission, Grand Rapids, MI: Baker Book House, 1978. Gailyn Van Rheenen, Missions: Biblical Foundations and Contemporary Strategies. Grand Rapids, MI: Zondervan Publishing Co., 1996. Vincent Donovan, Christianity Rediscovered. Maryknoll, NY: Orbis Books, 1991. Bruce E. Olson, Bruchko. Carol Stream, IL: Creation Press, 1973. James M. Phillips and Robert T. Coote, Toward the 21st Century in Christian Mission, Grand Rapids, MI: Wm. B. Eerdmans, 1993. Darrell Whiteman, Anthropology and Mission: The Incarnational Connection. 2003. Copies can be purchased through the ESJ School of World Mission and Evangelism. Call Julie at 859-858-2259. Cost is $2 plus posage.https://place.asburyseminary.edu/syllabi/2853/thumbnail.jp

Automatic transducer switching provides accurate wide range measurement of pressure differential

Automatic pressure transducer switching network sequentially selects any one of a number of limited-range transducers as gas pressure rises or falls, extending the range of measurement and lessening the chances of damage due to high pressure

EMPLOYER SIZE, HUMAN CAPITAL, AND RURAL WAGES: IMPLICATIONS FOR SOUTHERN RURAL DEVELOPMENT

A recent trend in rural development policy emphasizes small business development in place of industrial recruitment. To analyze some of the likely effects of expanding the proportion of small firms in local economies, an empirical wage rate model incorporating employer size was developed, and parameters were estimated using household date from rural Putnam County, Georgia. The estimates indicated that large employers offered higher wages than small employers and that the wage premium they offered was greater for blacks than for whites. These results support Thomas Till's argument that southern rural counties with relatively large black populations should not abandon efforts to attract large employers. Other factors associated with higher wages included level of education, previous labor force experience, and employment in certain occupations and industries.Community/Rural/Urban Development, Labor and Human Capital,

Will Washington Provide Its Own Feedstocks for Biofuels?

The study finds that Washington State’s field corn, sugar beet and canola production could satisfy only a small percentage of the State’s annual gasoline or diesel consumption. Linear programming projections for 2008 showed a relatively close match between projected and actual production. Projections for 2009-2011 showed no increase in the State’s capacity to increase biofuel crop feedstocks. In comparison to crop feedstocks, Washington’s total annual lignocellulosic biomass is abundant. However, only a fraction of the biomass could be converted to biofuel due to high costs of collection and processing, competing markets for some biomass, and limitations in current technology.biofuels, biofuel feedstocks, canola, cellulosic inventories, grain corn, linear programming, Washington State

Iron specificity of a biosensor based on fluorescent pyoverdin immobilized in sol-gel glass

Two current technologies used in biosensor development are very promising: 1. The sol-gel process of making microporous glass at room temperature, and 2. Using a fluorescent compound that undergoes fluorescence quenching in response to a specific analyte. These technologies have been combined to produce an iron biosensor. To optimize the iron (II or III) specificity of an iron biosensor, pyoverdin (a fluorescent siderophore produced by Pseudomonas spp.) was immobilized in 3 formulations of porous sol-gel glass. The formulations, A, B, and C, varied in the amount of water added, resulting in respective R values (molar ratio of water:silicon) of 5.6, 8.2, and 10.8. Pyoverdin-doped sol-gel pellets were placed in a flow cell in a fluorometer and the fluorescence quenching was measured as pellets were exposed to 0.28 - 0.56 mM iron (II or III). After 10 minutes of exposure to iron, ferrous ion caused a small fluorescence quenching (89 - 97% of the initial fluorescence, over the range of iron tested) while ferric ion caused much greater quenching (65 - 88%). The most specific and linear response was observed for pyoverdin immobilized in sol-gel C. In contrast, a solution of pyoverdin (3.0 μM) exposed to iron (II or III) for 10 minutes showed an increase in fluorescence (101 - 114%) at low ferrous concentrations (0.45 - 2.18 μM) while exposure to all ferric ion concentrations (0.45 - 3.03 μM) caused quenching. In summary, the iron specificity of pyoverdin was improved by immobilizing it in sol-gel glass C

Remedial Stability Analysis of Unstable Eastern Approach Embankment, Bluegrass Parkway Bridges over Chaplin River

In a meeting held on March 7, 1973, the Division of Research was requested to perform a supplementary slope stability analysis of the unstable, eastern approach embankment and foundation located at the crossing of the Bluegrass Parkway over Chaplin River and extending between Stations 2317+14 and 2321+00. Previously (see referenced report), two remedial schemes had been considered for increasing the stability of the unstable soil mass to an acceptable level. Those included: 1) loading the toe area of the existing, eastern approach slope with a berm, including a sloping berm, and 2) unloading the upper portion of the eastern slope by excavation, that is, decreasing the original approach slope (1.5 horizontal to 1 vertical), which would require an extension of the bridges, construction of piers at the present locations of the abutments and a relocation of the abutments. In the report cited, consideration was given primarily to using a berm to stabilize the eastern approach slope. Normally, that method of increasing the stability of an unstable embankment is the most economical. However, loading the toe area of the existing slope with a berm was considered undesirable in the meeting of March 7, 1973, because a berm would extend into the Chaplin River channel and alter channel hydraulics by constricting the channel area. Furthermore, there was a question of whether the berm materials could withstand the high velocities of Chaplin River. Consequently, an in-depth stability analysis was performed which involved excavation of the approach embankment and a relocation of the abutments