Temperature and Volumetric Fraction Measurements in a Hot Gas Laden With Water Droplets

2003 ◽  
Vol 125 (2) ◽  
pp. 356-364 ◽  
Author(s):  
Paolo Ruffino ◽  
Marino di Marzo
Keyword(s):  
Measurement Techniques ◽  
Evaporative Cooling ◽  
Optical Methods ◽  
Gas Temperature ◽  
Water Droplets ◽  
Volumetric Fraction ◽  
Hot Gas ◽  
Novel Approach ◽  
Two Temperatures ◽  
The Difference

Two temperatures can be detected in a hot gas laden with water droplets. The lower one is the temperature read by a sensor immersed in the flow. This measurement is affected by significant evaporative cooling resulting in readings much below the real gas temperature. The higher one is the temperature of the gas. The difference between these two temperatures is proportional to the water volumetric fraction in the flow. On this basis, a new technique for the measurement of the water volumetric fraction is proposed. The results are compared with a conventional measurement technique based on optical methods. A novel approach to the gas temperature measurement is also introduced. The sensing device is kept at temperatures exceeding the Leidenfrost transition and therefore it is insensitive to the presence of the water droplets. Independent measurement techniques developed at the Evaporative Cooling Sensor Accuracy Test (ECSAT) facility provide the data to validate the measurements obtained with the Above Leidenfrost Temperature and Evaporative Cooling (ALTEC) sensor.

Legal Update: North Dakota Supreme Court: Third Edition of Guides is “Most Current”

1999 ◽  
Vol 4 (1) ◽  
pp. 6-7
Author(s):  
James J. Mangraviti
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Measurement Techniques ◽  
Fourth Edition ◽  
Hip Motion ◽  
The Difference ◽  
The Right ◽  
Hip Flexion ◽  
Hip Rotation ◽  
Hip Extension

Abstract The accurate measurement of hip motion is critical when one rates impairments of this joint, makes an initial diagnosis, assesses progression over time, and evaluates treatment outcome. The hip permits all motions typical of a ball-and-socket joint. The hip sacrifices some motion but gains stability and strength. Figures 52 to 54 in AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fourth Edition, illustrate techniques for measuring hip flexion, loss of extension, abduction, adduction, and external and internal rotation. Figure 53 in the AMA Guides, Fourth Edition, illustrates neutral, abducted, and adducted positions of the hip and proper alignment of the goniometer arms, and Figure 52 illustrates use of a goniometer to measure flexion of the right hip. In terms of impairment rating, hip extension (at least any beyond neutral) is irrelevant, and the AMA Guides contains no figures describing its measurement. Figure 54, Measuring Internal and External Hip Rotation, demonstrates proper positioning and measurement techniques for rotary movements of this joint. The difference between measured and actual hip rotation probably is minimal and is irrelevant for impairment rating. The normal internal rotation varies from 30° to 40°, and the external rotation ranges from 40° to 60°.

First-Principles Theory of Polarization in Ferroelectrics

1992 ◽  
Vol 291 ◽  
Author(s):  
R. Resta ◽  
M. Posternak ◽  
A. Baldereschi
Keyword(s):  
Spontaneous Polarization ◽  
First Principles ◽  
Ferroelectric Materials ◽  
Recent Experimental Data ◽  
Modern Theory ◽  
Rigid Core ◽  
Novel Approach ◽  
Prototype Structure ◽  
Effective Charges ◽  
The Difference

ABSTRACTWe outline a modern theory of the spontaneous polarization P in pyroelectric and ferroelectric materials. Although P itself isnot an observable, the difference ΔP between two crystal states can indeed be measured and calculated. We define P as the difference between the polar structure and a suitably chosen nonpolar prototype structure. We previously proposed and implemented a supercell scheme in order to evaluate P in pyroelectric BeO; here we adopt an approach recently developed by King-Smith and Vanderbilt, where ΔP is obtained from the computation of Berry's phases, with no use of supercells. We apply this novel approach, which is numerically very convenient, in order to revisit our previous work on BeO. We then perform a first-principles investigation of the spontaneous polarization P of KNbO3 in its tetragonal phase, which is a well studied perovskite ferroelectric. Our calculated P value confirms the most recent experimental data. The polarization is linear in the ferroelectric distortion; the Born effective charges show strong variations from nominal ionic values, and a large inequivalence of the 0 ions. Only the highest nine valence-band states (O 2p) contribute to P, while all the other states behave as rigid core states.

Firefighter Equipment Operational Environment: Evaluation of Thermal Conditions

2017 ◽  
Author(s):  
Daniel Madrzykowski ◽  
Keyword(s):  
Heat Flux ◽  
Thermal Performance ◽  
Protective Clothing ◽  
Thermal Conditions ◽  
Gas Temperature ◽  
Gas Velocity ◽  
Hot Gas ◽  
Performance Requirements ◽  
Fire Environment ◽  
Fire Ground

The goal of this study was to review the available literature to develop a quantitative description of the thermal conditions firefighters and their equipment are exposed to in a structural fire environment. The thermal exposure from the modern fire environment was characterized through the review of fire research studies and fire-ground incidents that provided insight and data to develop a range of quantification. This information was compared with existing standards for firefighting protective equipment to generate a sense of the gap between known information and the need for improved understanding. The comparison of fire conditions with the thermal performance requirements of firefighter protective gear and equipment demonstrates that a fire in a compartment can generate conditions that can fail the equipment that a firefighter wears or uses. The review pointed out the following: 1. The accepted pairing of gas temperature ranges with a corresponding range of heat fluxes does not reflect all compartment fire conditions. There are cases in which the heat flux exceeds the hazard level of the surrounding gas temperature. 2. Thermal conditions can change within seconds. Experimental conditions and incidents were identified in which firefighters would be operating in thermal conditions that were safe for operation based on the temperature and heat flux, but then due to a change in the environment the firefighters would be exposed to conditions that could exceed the protective capabilities of their PPE. 3. Gas velocity is not explicitly considered within the thermal performance requirements. Clothing and equipment tested with a hot air circulating (convection) oven are exposed to gas velocities that measure approximately 1.5 m/s (3 mph). In contrast, the convected hot gas flows within a structure fire could range from 2.3 m/s (5 mph) to 7.0 m/s (15 mph). In cases where the firefighter or equipment would be located in the exhaust portion of a flow path, while operating above the level of the fire, the hot gas velocity could be even higher. This increased hot gas velocity would serve to increase the convective heat transfer rate to the equipment and the firefighter, thereby reducing the safe operating time within the structure. 4. Based on the limited data available, it appears currently available protective clothing enables firefighters to routinely operate in conditions above and beyond the "routine" conditions measured in the fire-ground exposure studies conducted during the 1970s. The fire service and fire standards communities could benefit from an improved understanding of: • real world fire-ground conditions, including temperatures, heat flux, pressure, and chemical exposures; • the impact of convection on the thermal resistance capabilities of firefighting PPE and equipment; and • the benefits of balancing the thermal exposures (thermal performance requirements) across different components of firefighter protective clothing and safety equipment. Because it is unlikely due to trade offs in weight, breathe-ability, usability, cost, etc., that fireproof PPE and equipment will ever be a reality, fire officers and fire chiefs need to consider the capabilities of the protection that their firefighters have when determining fire attack strategies and tactics to ensure that the PPE and equipment is kept within its design operating environment, and that the safety buffer it provides is maintained.

scholarly journals Demography and feeding behavior of Stenostomum leucops (Dugés, 1828)

2016 ◽  
Vol 75 (s1) ◽  
Author(s):  
Alma R. Núñez-Ortiz ◽  
Sarma Nandini ◽  
S.S.S. Nandini
Keyword(s):  
Functional Response ◽  
Food Preference ◽  
Type Ii ◽  
Final Density ◽  
Two Temperatures ◽  
The Difference ◽  
Growth Experiments ◽  
Pelagic Communities ◽  
Type Ii Functional Response ◽  
Planktonic Communities

<p>Freshwater turbellarians, despite their mainly benthic habits, interact with pelagic communities of rotifers and cladocerans. However, very little is known about their demographic characteristics, food preference and functional response. To fill that gap we studied one of the most widely spread species, <em>Stenostomum leucops</em>.  We conducted population growth experiments using abundant food (several rotifer and cladocerans species). To evaluate possible impact of <em>S. leucops</em> on planktonic communities, we conducted prey preference experiments at two temperatures: 18 and 23°C. The number of rotifers and cladocerans consumed was calculated by the difference between the initial and final density. We found that diets supplemented with fresh algae achieved higher <em>S. leucops</em> densities than those with detritus supplements in their diets. In the case of animal diets, <em>Euchlanis dilatata</em> allowed <em>S. leucops</em> reach higher densities than the other zooplankton species; <em>E. dilatata</em> was positively selected for in the selectivity study at both 18 and 23°C.  <em>Stenostomum leucops</em> showed a type II functional response on rotifers and the cladoceran <em>Alona glabra</em>. Our results suggest that <em>S. leucops</em> select their prey according to their vulnerability using different mechanisms, which optimize their food intake.</p>

scholarly journals Analisis Pengaruh High Pressure Compressor Rotor Clearance Terhadap Exhaus Gas Temperature Margin pada CFM56-7

2021 ◽  
Vol 6 (2) ◽  
pp. 50-55
Author(s):  
Wildan Sofary Darga ◽  
Edy K. Alimin ◽  
Endah Yuniarti
Keyword(s):  
High Pressure ◽  
Engine Performance ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Compressor Rotor ◽  
High Pressure Compressor ◽  
The Difference ◽  
Gas Turbine Exhaust ◽  
Temperature Margin ◽  
Pressure Compressor

Exhaust Gas Temperatue is an parameter where the hot gases’s temperature leave the gas turbine. Exhaust gas temperature margin is the difference between highest temperature at take off phase with redline on indicator (???????????? ???????????????????????? °????=???????????? ????????????????????????????−???????????? ???????????????? ????????????). EGTM is one of any factor to determine engine performance. A good perfomance of an engine when it has a big margin (EGTM), during operation of an engine the EGTM could decrease untill 0 (zero). So many factors could affect EGTM deteroration there are: distress hardware such as airfoil erosion, leak of an airseals, and increase of clearance between tip balde and shroud. Increase of clearance happens in high pressure compressor rotor clearance. In CFM56-7 have 9 stage(s) of high pressure compressor and each stage give the EGT Loses. The calculation of EGT Effect/Losses is actual celarance – minimum clearance x 1000 x EGT Effect °C, where actual clearance define by the substraction of outside diameter’s rotor with inside diameter’s shroud, minimum clearance define in the manual, 1000 is adjustment from mils/microinch to inch, and EGT Effect is temperature that define in the manual. The analysist had done with 6 (six) engine serial number and proceed by corelation that shown linkage between clearance and EGT Effect, the corelation is strong shown the result of corelation (r) is 0.994275999 or nearest 1.

scholarly journals Comprehensive Assimilation of Fire Suppression Modeling and Simulation of Radiant Fire by Water and Its Synergistic Effects with Carbon Dioxide

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5850
Author(s):  
Hassan Raza Shah ◽  
Kun Wang ◽  
Xu Qing Lang ◽  
Jing Wu Wang ◽  
Jing Jun Wang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Synergistic Effects ◽  
Fire Suppression ◽  
Water Mist ◽  
Pool Fire ◽  
Water Suppression ◽  
Water Droplets ◽  
Film Forming ◽  
The Difference ◽  
Suppression Effects

Recently, water has been employed as a supportive agent for the preparation of multiple suppressing agents including aqueous film forming foams (AFFF), which is combined with different kinds of gases for its various applications. In this study, the water mist is chosen for the gas-suppressing agent such as carbon dioxide. Our work investigated the suppression effects of water droplets on the n-heptane pool fire, and its mixture with carbon dioxide, respectively. The size and frequency of droplets with their effect on temperature and suppression was compared to observe the difference in the suppression. Initially, it was found that the droplets having a larger droplet size were found to be more efficient as compared to the smaller droplets with respect to the heat release rate, temperature, and radiation. Afterwards, a mixture of water droplets and carbon dioxide was simultaneously discharged to compare the difference between these two suppressing agents. It was found that the synergistic effect of the mixture has higher advantages over the use of only water suppression. It helps reduce the hot gases that surround the pool fire and allows the water mist to travel efficiently towards the fuel. Both suppression mechanisms were set to similar initial parameters that lead to different outcomes.

scholarly journals Immune cell type, cell activation, and single cell heterogeneity revealed by label-free optical methods

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Nicolas Pavillon ◽  
Nicholas I. Smith
Keyword(s):  
Single Cell ◽  
Cell Activation ◽  
Immune Cell ◽  
Global Analysis ◽  
Measurement Techniques ◽  
Optical Methods ◽  
Phase Imaging ◽  
Label Free ◽  
Experimental Conditions ◽  
Culturing Conditions

AbstractMeasurement techniques that allow the global analysis of cellular responses while retaining single-cell sensitivity are increasingly needed in order to understand complex and dynamic biological processes. In this context, compromises between sensitivity, degree of multiplexing, throughput, and invasiveness are often unavoidable. We present here a noninvasive optical approach that can retrieve quantitative biomarkers of both morphological and molecular phenotypes of individual cells, based on a combination of quantitative phase imaging and Raman spectroscopy measurements. We then develop generalized statistical tools to assess the influence of both controlled (cell sub-populations, immune stimulation) and uncontrolled (culturing conditions, animal variations, etc.) experimental parameters on the label-free biomarkers. These indicators can detect different macrophage cell sub-populations originating from different progenitors as well as their activation state, and how these changes are related to specific differences in morphology and molecular content. The molecular indicators also display further sensitivity that allow identification of other experimental conditions, such as differences between cells originating from different animals, allowing the detection of outlier behaviour from given cell sub-populations.

scholarly journals Physical Aspects of Deposition From Coal Water Fuels Under Gas Turbine Conditions

1989 ◽  
Author(s):  
Richard A. Wenglarz ◽  
Ralph G. Fox
Keyword(s):  
Gas Turbine ◽  
Combustion Products ◽  
Control Measures ◽  
Unburned Carbon ◽  
Test Results ◽  
Gas Temperature ◽  
Hot Gas ◽  
Stators And Rotors ◽  
Temperature Surface ◽  
Deposition Control

Deposition, erosion, and corrosion (DEC) experiments were conducted using three coal-water fuels (CWF) in a staged subscale turbine combustor operated at conditions of a recuperated turbine. This rich-quench-lean (RQL) combustor appears promising for reducing NOx levels to acceptable levels for future turbines operating with CWF. Specimens were exposed in two test sections to the combustion products from the RQL combustor. The gas and most surface temperatures in the first and second test sections represented temperatures in the first stators and rotors, respectively, of a recuperated turbine. The test results indicate deposition is affected substantially by gas temperature, surface temperature, and unburned carbon due to incomplete combustion. The high rates of deposition observed at first stator conditions showed the need for additional tests to identify CWF coals with lower deposition tendencies and to explore deposition control measures such as hot gas cleanup.

scholarly journals Investigation of Regularities of Heat and Mass Transfer and Phase Transitions during Water Droplets Motion through High-Temperature Gases

2014 ◽  
Vol 6 ◽  
pp. 865856 ◽  
Author(s):  
Roman S. Volkov ◽  
Olga V. Vysokomornaya ◽  
Genii V. Kuznetsov ◽  
Pavel A. Strizhak
Keyword(s):  
Mass Transfer ◽  
Phase Transitions ◽  
High Temperature ◽  
Heat And Mass Transfer ◽  
Water Droplet ◽  
Small Neighborhood ◽  
Droplet Evaporation ◽  
Optical Methods ◽  
Water Droplets ◽  
Two Phase

The macroscopic regularities of heat and mass transfer and phase transitions during water droplets motion through high-temperature (more than 1000 K) gases have been investigated numerically and experimentally. Water droplet evaporation rates have been established. Gas and water vapors concentrations and also temperature values of gas-vapor mixture in small neighborhood and water droplet trace have been singled out. Possible mechanisms of droplet coagulation in high-temperature gas area have been determined. Experiments have been carried out with the optical methods of two-phase gas-vapor-droplet mixtures diagnostics (“Particle Image Velocimetry” and “Interferometric Particle Imaging”) usage to assess the adequateness of developed heat and mass transfer models and the results of numerical investigations. The good agreement of numerical and experimental investigation results due to integral characteristics of water droplet evaporation has been received.

Application of Optical Scanning and Photogrammetry for Evaluation of Geometrical Tolerance Values

2013 ◽  
Author(s):  
Andrzej Gessner ◽  
Roman Staniek ◽  
Jakub Michałek
Keyword(s):  
Cross Sections ◽  
Optical Measurement ◽  
Measurement Techniques ◽  
Reference Method ◽  
Test Stand ◽  
Optical Methods ◽  
Test Surface ◽  
Test Plate ◽  
Optical Scanning ◽  
Measurement Area

The hereby presented research, funded by the restricted grant LIDER, NCBiR, deals, in part, with the identification of the full implementation potential of the proposed optical measurement techniques in determination of surface flatness parameters, and their comparative assessment. The test methods included the photogrammetric measurement technique (TRITOP, GOM) and the structural light scanning approach (scanner ATOS, GOM), while the CMM measurement (DEA Global Image Clima) was the reference method. The accordingly designed and assembled experimental test stand comprised 2 steel plates. The test surfaces of the plates were appropriately ground; subsequently, the entire test stand was blackened to ascertain efficient optical scanning. Furthermore, the plates were connected by means of 8 screws, thus introducing considerable distortion. A measurement area of 140 × 240 mm was defined on the plate test surface, as determined by CMM, denoting 15 measurement paths of 240 mm in length, distributed every 10 mm, and characterized by measurement point densities of 1, 5, and 20 pt/mm. The reference CMM measurements were conducted on 3 consecutive days at different times (22 measurements in total) to exclude any possible surface modifications. Subsequently, optical scanning was applied and the measurement points lying at the cross-sections of the CMM measurement paths were isolated from the obtained polygon mesh. To further apply the photogrammetric method, the test surface was labeled with markers distributed every 10 mm and coinciding with the CMM measurement paths. Comparative analysis of the flatness parameter for the selected CMM measurement and the measurement values obtained by means of the tested optical methods included: - the entire measurement area, - the sections comprising 80, 60, 50, 45, 40, 30, 20, 15, and 10 % of the entire measurement area, decreasing centrically, - the measurement sub-areas of 30 × 50 mm allotted in the corners and in the center of the test plate. The photogrammetric error of the tested parameter was established at 1.26–19.82 %, depending on the size of the measurement area. The corresponding error value, as determined by the structural light scanning technique, amounted to 0.03–4.31 %.

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