Lineberry, J. T.; Galanga, F. L.; Frazier, J. W.
A summary of testing of the low mass flow diagonal conducting sidewall MHD generator in the CFFF is given. These summaries include details of the powered generator tests conducted during the 1985 LMF4 test series. A presentation of experimental generator electrical data collected during these tests is included. The quality of these data is discussed and a review of representative data presentations is made as a means of identifying phenomena associated with coal-fired MHD generators. Unique characteristics of coal slag effects upon electrical performance are seen in the voltage profiles and power characteristics for the generator. Fundamental theoretical analyses of the generator are used to qualify the levels of generator performance that were demonstrated during testing. These analyses are directed at isolating possible sources that have caused performance deficiencies and anomalies seen in the test data.
Full Text Available Previous studies have been conducted to measure fatigue using flicker test. However, the validity of the device is still unknown empirically. This study proposed a modification of fatigue measuring apparatus based on flicker test. The modifications were developed from the framework of human factors product design, with the stages including analysis of the existing condition, operational concept, user requirements, performance criteria, system requirements, design prototyping, usability testing and final testing. The proposed apparatus consists of two main parts: a stimulus source and a control device as input. The stimulus is given by three lights with adjustable position and orientation angle. A LCD screen was provided to display status and result of the measurement. The control device consists of three buttons to respond the stimulus accordingly. Product testings were done through 1 a laboratory experiment with activities of critical reading and arithmetic complex and 2 a field study on a night bus driver. All the tasks selected represent works with a dominant mental workload. The laboratory experiments showed the range of Critical Flicker Fusion Frequency (CFFF at work of 14-40 HZ, with the average decline of CFFF values of 5.3 Hz in arithmetic complex and 4.8 Hz in critical reading activities. The study on the night bus driver resulted in CFFF value range of 18-40 Hz with the average delta CFFF of 8.97 Hz. Both testings suggest that flicker test with CFFF indicators can be used to measure mental fatigue. In addition, the proposed framework used in this design development can be used as a reference in designing various products by taking human factor aspects as the focus such as user needs and user limitations.
An analysis is presented of the effect of noncoincident sampling on the measurement of atomic number density and temperature by multiwavelength emission absorption. The assumption is made that the two signals, emission and transmitted lamp, are time resolved but not coincident. The analysis demonstrates the validity of averages of such measurements despite fluctuations in temperature and optical depth. At potassium-seeded MHD conditions, the fluctuations introduce additional uncertainty into measurements of potassium atom number density and temperature but do not significantly bias the average results. Experimental measurements in the CFFF aerodynamic duct with coincident and noncoincident sampling support the analysis.
This seventh semi-annual status report of the MHD Technology Transfer, Integration and Review Committee (TTIRC) summarizes activities of the TTIRC during the period April 1991 through September 1991. It includes a summary and minutes of the General Committee meeting, progress summaries of ongoing POC contracts, discussions pertaining to technical integration issues in the POC program, and planned activities for the next six months. The meeting included test plan with Western coal, seed regeneration economics, power management for the integrated topping cycle and status of the Clean Coal Technology Proposal activities. Appendices cover CDIF operations HRSR development, CFFF operations etc.
Contents: Large Superconductive Magnets; Superconductivity Activities at LASL; Superconductivity Studies at Argonne National Laboratory; CFFF MHD Magnet at Argonne National Laboratory; MHD Superconducting Magnets; Fermilab's Energy Saver; LCP and 12 Tesla Programs at ORNL; Division of Electric Energy System's Superconductivity Program; Development of Standards for Practical Superconductors; Casting of Dendritic Cu-Nb Alloys for Superconducting Wire; Review of Recent Developments of Multifilamentary Nb3Sn by 'in Situ' and Cold Powder Metallurgy Processes; Superconducting Magnet Facility at NRL; Airborne Superconductor Applications; High Pressure Synthesis Program at Benet Weapons Laboratory Watervliet Arsenal; CuCl; Stability and Exciton Population Percursive to Anomalous Diagmagnetism; Navy Superconductive Machinery Development Program; and Superconducting Materials Program at NRL.
Progress continued at MHD coal-fired flow facility. UTSI reports on progress in developing the technology for the steam bottoming portion of the MHD Steam Combined Cycle Power Plant. No Proof-of-Concept (POC) testing was conducted during the quarter but data analyses are reported from the test conducted during the prior quarter. Major results include corrosion data from the first 500 hours of testing on candidate tube materials in the superheater test module (SHTM). Solids mass balance data, electrostatic precipitator (ESP) and baghouse (BH) performance data, diagnostic systems and environmental data results from previous POC tests are included. The major activities this quarter were in facility modifications required to complete the scheduled POC test program. Activities reported include the installation of an automatic ash/seed removal system on the SHTM, the BH, and ESP hoppers. Also, a higher pressure compressor (350 psi) is being installed to provide additional blowing pressure to remove solids deposits on the convective heat transfer tubes in the high temperature zone where the deposits are molten. These activities are scheduled to be completed and ready for the next test, which is scheduled for late May 1990. Also, experiments on drying western coal are reported. The recommended system for modifying the CFFF coal system to permit processing of western coal is described. Finally, a new effort to test portions of the TRW combustor during tests in the CFFF is described. The status of system analyses being conducted under subcontract by the Westinghouse Electric Corporation is also described. 2 refs., 18 figs., 3 tabs.
V.J. Clemente Suárez
Full Text Available Antecedentes y objetivos: El análisis de la respuesta orgánica durante el combate es un campo de estudio poco tratado en la bibliografía específica, por ello se planteo como objetivo de este trabajo el analizar el efecto de una simulación de combate en el organismo de los combatientes. Material y Métodos: Se analizó el umbral de frecuencia crítica de fusión (UFCF como medio de detectar fatiga del sistema nervioso central (SNC, fuerza explosiva de piernas, fuerza isométrica, lactato sanguíneo y percepción subjetiva de esfuerzo en 20 combatientes antes y después de realizar una simulación de combate. Resultados: Después de la simulación los sujetos mostraron un aumento significativo (pBackground and Objectives: Analysis of organic response in combat is a bit field of study specifically studied in specific literature, for this reason the objective of this work is to analyze the effect of a combat simulation in the organism of soldiers. Material and Methods: We analyzed the critical flicker fusion frequency (CFFF as a means of detecting fatigue of central nervous system (CNS, leg explosive strength, isometric strength, blood lactate and rating of perceived exertion in 20 soldiers before and after performing a combat simulation. Results: After combat simulation, soldiers showed a significant increase (p<0,05 in lactate levels (2,57±0,62 mmol/l vs. 4,92±2,18 mmol/l and isometric strength and a decrease in legs explosive strength. CFFF values decreased, showing signs of fatigue of CNS. Conclusions: Combat simulation was highly stressful, showing signs of fatigue of the CNS, are carried out in anaerobic conditions, despite the low speed o execution, and the subjective perception of effort does not correspond to the organic response obtained. These data could use to adapting current training systems for current missions in combat zones.
hayder M. al-kuraishy
Full Text Available Abstract Aim: The present study investigates the effect of combined treatment with Ginkgo biloba and/or rhodiola rosea on psychomotor vigilance task and short-term working memory accuracy. Subjects and Methods: A total number of 112 volunteers was enrolled to study the effect of Ginkgo biloba and rhodiola rosea on psychomotor vigilance task and short-term working memory accuracy as compared to placebo effects,the central cognitive effect was assessed by Critical flicker-fusion frequency (CFFF, Psychomotor vigilance Task (PVT and computerized N-back test. Results: Placebo produced no significant effects on all neurocognitive tests measure p>0.05 in normal healthy volunteers, Ginkgo biloba or Rhodiola rosea improve psychomotor vigilance task and low to moderate working memory accuracy, The combined effect of Rhodiola rosea and Ginkgo biloba leading to more significant effect on psychomotor vigilance task, all levels of short term working memory accuracy and critical fusion versus flicker p<0.01, more than of Ginkgo biloba or Rhodiola rosea when they used alone. Conclusion: The combined effect of Rhodiola rosea and Ginkgo biloba leading to more significant effect on cognitive function than either Ginkgo biloba or Rhodiola rosea when they used alone. [J Intercult Ethnopharmacol 2016; 5(1.000: 7-13
Contado, Catia; Argazzi, Roberto; Amendola, Vincenzo
Many advanced industrial and biomedical applications that use silver nanoparticles (AgNPs), require that particles are not only nano-sized, but also well dispersed, not aggregated and not agglomerated. This study presents two methods able to give rapidly sizes of monodispersed AgNPs suspensions in the dimensional range of 20-100nm. The first method, based on the application of Mie's theory, determines the particle sizes from the values of the surface plasmon resonance wavelength (SPRMAX), read from the optical absorption spectra, recorded between 190nm and 800nm. The computed sizes were compared with those determined by transmission electron microscopy (TEM) and dynamic light scattering (DLS) and resulted in agreement with the nominal values in a range between 13% (for 20nm NPs) and 1% (for 100nm NPs), The second method is based on the masterly combination of the Sedimentation Field Flow Fractionation (SdFFF - now sold as Centrifugal FFF-CFFF) and the Optical Absorption Spectroscopy (OAS) techniques to accomplish sizes and quantitative particle size distributions for monodispersed, non-aggregated AgNPs suspensions. The SdFFF separation abilities, well exploited to size NPs, greatly benefits from the application of Mie's theory to the UV-vis signal elaboration, producing quantitative mass-based particle size distributions, from which trusted number-sized particle size distributions can be derived. The silver mass distributions were verified and supported by detecting off-line the Ag concentration with the graphite furnace atomic absorption spectrometry (GF-AAS).
Balestra, C; Lafère, P; Germonpré, P
One of the possible risks incurred while diving is inert gas narcosis (IGN), yet its mechanism of action remains a matter of controversy. Although providing insights in the basic mechanisms of IGN, research has been primarily limited to animal studies. A human study, in real diving conditions, was needed. Twenty volunteers within strict biometrical criteria (male, age 30-40 years, BMI 20-23, non smoker) were selected. They performed a no-decompression dive to a depth of 33 mfw for 20 min and were assessed by the means of critical flicker fusion frequency (CFFF) measurement before the dive, during the dive upon arriving at the bottom, 5 min before the ascent, and 30 min after surfacing. After this late measurement, divers breathed oxygen for 15 min and were assessed a final time. Compared to the pre-dive value the mean value of each measurement was significantly different (p nitrogen supersaturation), 124.4 ± 10.8 versus 124.2 ± 3.9 %. This simple study suggests that IGN (at least partially) depends on gas-protein interactions and that the cerebral impairment persists for at least 30 min after surfacing. This could be an important consideration in situations where precise and accurate judgment or actions are essential.
Altstatt, M. C.; Attig, R. C.; Brosnan, D. A.
Significant activity, task status, planned research, testing, development, and conclusions for the Magnetohydrodynamics (MHD) Coal-Fired Flow Facility (CFFF) and the Energy Conversion Facility (ECF) are described. On Task 1, the first phase of the downstream quench system was completed. On Task 2, all three combustor sections were completed, hydrotested, ASME code stamped, and delivered to UTSI. The nozzle was also delivered. Fabrication of support stands and cooling water manifolds for the combustor and vitiation heater were completed, heat transfer and thermal stress analysis, along with design development, were conducted on the generator and radiant furnace and secondary combustor installation progressed as planned. Under Task 3 an Elemental Analyzer and Atomic Absorption Spectrophotometer/Graphite Furnace were received and installed, sites were prepared for two air monitoring stations, phytoplankton analysis began, and foliage and soil sampling was conducted using all study plots. Some 288 soil samples were combined to make 72 samples which were analyzed. Also, approval was granted to dispose of MHD flyash and slag at the Franklin County landfill. Task 4 effort consisted of completing all component test plans, and establishing the capability of displaying experimental data in graphical format. Under Task 7, a preliminary testing program for critical monitoring of the local current and voltage non-uniformities in the generator electrodes was outlined, electrode metal wear characteristics were documented, boron nitride/refrasil composite interelectrode sealing was improved, and several refractories for downstream MHD applications were evaluated with promising results.
The Diagnostic Instrumentation and Analysis Laboratory (DIAL) at Mississippi State University (MSU), under U.S. Department of Energy (DOE) Contract No. DE-AC02-80ET-15601, Diagnostic Development and Support of MHD Test Facilities, developed diagnostic instruments for magnetohydrodynamic (MHD) power train data acquisition and for support of MHD component development test facilities. Microprocessor-controlled optical instruments, initially developed for Heat Recovery/Seed Recovery (HRSR) support, were refined, and new systems to measure temperatures and gas-seed-slag stream characteristics were developed. To further data acquisition and analysis capabilities, the diagnostic systems were interfaced with DIAL`s computers. Technical support was provided for the diagnostic needs of the national MHD research effort. DIAL personnel also cooperated with government agencies and private industries to improve the transformation of research and development results into processes, products and services applicable to their needs. The initial contract, Testing and Evaluation of Heat Recovery/Seed Recovery, established a data base on heat transfer, slagging effects on heat transfer surfaces, metal durability, secondary combustor performance, secondary combustor design requirements, and other information pertinent to the design of HR/SR components at the Coal-Fired Flow Facility (CFFF). To accomplish these objectives, a combustion test stand was constructed that simulated MHD environments, and mathematical models were developed and evaluated for the heat transfer in hot-wall test sections. Two transitions occurred during the span of this contract. In May 1983, the objectives and title of the contract changed from Testing and Evaluation of Heat Recovery/Seed Recovery to Diagnostic Development and Support of MHD Test Facilities. In July 1988, the research laboratory`s name changed from the MHD Energy Center to the Diagnostic Instrumentation and Analysis Laboratory.