The Experts below are selected from a list of 195 Experts worldwide ranked by ideXlab platform
Charles T Campbell - One of the best experts on this subject based on the ideXlab platform.
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surface kinetics and energetics from single crystal adsorption calorimetry lineshape analysis methyl from methyl iodide on pt 1 1 1
Journal of Catalysis, 2013Co-Authors: Trent L Silbaugh, Eric M Karp, Charles T CampbellAbstract:Abstract The first use of single crystal adsorption calorimetry (SCAC) to probe the kinetics of surface chemical reactions is presented. It is applied to study a common situation encountered in catalytic mechanisms, wherein a gas quickly populates a molecularly adsorbed state that then converts to more stable products on a slower timescale (10–1000 ms). We show that for such a two-step process, detailed analysis of the Heat-Detector signal’s time-response lineshape to a single pulse of gas provides the rate constant for the second step and the Heats of reaction for both of the elementary reactions. We apply this analysis to the dissociative adsorption of methyl iodide (CH3I) on Pt(1 1 1) at 270 K, to measure the Heats of reaction for the elementary steps involved and the rate constant for the slow step, all as a detailed function of coverage. At low coverage, the reaction is CH3Ig → CH3Iad → CH3,ad + Iad, followed at high coverage by CH3,ad → CHad + 2Had and CH3,ad + Had → CH4,g (above 0.08 ML total CH3,ad plus Iad). These results provide the rate constant for the dissociation of CH3Iad and the Heats of formation of both CH3,ad and CHad. These two Heats agree with values determined at 320 K where the rates are so fast that lineshape analysis is not needed, proving the validity of the lineshape analysis method introduced here for analyzing SCAC data.
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Improved pyroelectric Detectors for single crystal adsorption calorimetry from 100 to 350 K
Review of Scientific Instruments, 2010Co-Authors: Ole Lytken, Jason A. Farmer, Matthew C. Crowe, Charles T CampbellAbstract:The adsorption of atoms and molecules on single crystal surfaces allows one to produce well-characterized atomic, molecular, or dissociated adsorbates. Microcalorimetric measurement of the resulting adsorption energies, i.e., single crystal adsorption calorimetry, allows determination of the standard enthalpies of formation of these adsorbates. Methods are described for making an improved Heat Detector for such measurements, which greatly improves the signal-to-noise ratio, particularly at low temperatures (down to 100 K). The Heat Detector is an adaptation of a previously introduced design, based on a metallized pyroelectric polymer (β-polyvinylidene fluoride), which is pressed against the back of a single crystal during measurement but removed during sample preparation and annealing. The improvement is achieved by selectively etching the metal coating of the polymer, thus reducing the pyro- and piezoelectric noise from all nonessential regions of the polymer. We, furthermore, describe how to achieve a b...
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pyroelectric Heat Detector for measuring adsorption energies on thicker single crystals
Sensors and Actuators B-chemical, 2005Co-Authors: S F Diaz, N Shamir, Charles T CampbellAbstract:Abstract The direct measurement of adsorption Heats on the well-defined and highly ordered surfaces of single crystals (i.e., single crystal adsorption calorimetry, SCAC) has until now been performed only on samples with thickness of 0.2 or 1–8 μm, depending on the Heat detection method. This paper reports a modification to a β-polyvinylidene fluoride (PVDF) pyroelectric Heat Detector, which allows measurements on much thicker samples (∼80 μm) with similar signal-to-noise. The improvement is achieved by increasing the compression between the single crystal and the 9 μm thick PVDF Detector ribbon by pressing it with a thicker, insulating polymer, and by using a similarly-mounted reference Detector to subtract away some of the voltage noise due to mechanical vibrations (also detected by the piezoelectric PVDF ribbons). For a 75 μm NiAl(1 1 0) single crystal, a sensitivity of 5 V per adsorbed joule and a pulse-to-pulse standard deviation of 4% in the measured Heats are seen for adsorbed laser pulses of 3.7 μJ over a 0.138 cm 2 area. Application of this method to measure the Heats of adsorption of Pb onto NiAl(1 1 0) is demonstrated. The pulse-to-pulse standard deviation of the Heat of adsorption at high coverages, where the Heat is independent of coverage, is about ±5.2%, or 10.2 kJ/mol. This broadens the range of surfaces that can be studied by calorimetry, since this thickness can be achieved with nearly any single crystal material by simple mechanical thinning, whereas that is not possible with samples thinner than ∼50 μm over the required surface area of ∼1 cm 2 .
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A novel single-crystal adsorption calorimeter and additions for determining metal adsorption and adhesion energies
Review of Scientific Instruments, 1998Co-Authors: J. T. Stuckless, Nathan A. Frei, Charles T CampbellAbstract:A new microcalorimeter for measuring Heats of adsorption on clean single-crystal surfaces is described, and its operational characteristics are presented. The principle is similar to that pioneered by David King’s group: A pulse of gas from a molecular beam adsorbs on an ultrathin single crystal’s surface, causing a measurable transient Heat input and temperature rise. Our novel Heat Detector is a 9 μm thick pyroelectric polymer ribbon, which is mechanically driven to make a gentle mechanical/thermal contact to the back of the single-crystal sample during measurements. Advantages include use of thicker samples (1 μm), sample preparation at very high temperatures, and potential measurements at cryogenic temperatures. A novel chopped molecular beam of metal vapor and a method of correcting for absorbed radiation from the hot effusion cell are also described. This system is applied to study the Heats of adsorption of metals on clean, well-defined and single-crystalline surfaces as a detailed function of cove...
Gerald Steinbauer - One of the best experts on this subject based on the ideXlab platform.
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SSRR - The RoboCup Rescue Victim Dataset
2018 IEEE International Symposium on Safety Security and Rescue Robotics (SSRR), 2018Co-Authors: Peter Lorenz, Gerald SteinbauerAbstract:In this paper, we introduce a victim dataset for the RoboCup Rescue competitions. The RoboCup Rescue robots have to collect points within several disciplines, e.g. a search task within an area to survey simulated baby doll (victim). When a robot comes across a victim, a Heat Detector does not completely proof if this is a living being and not just a Heat emitting somewhat else. Further investigations are necessary so that a face detection could prove the existence of a victim. Lots of face detection approaches can be found in literature, which manly are used for human face recognition. These cannot be straightforward used for victim faces which are, in case of the RoboCup Rescue competitions, typically dolls. Thus we present the results of standard approaches and developed an own approach via bag-of-visual-words (BoVW).
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The RoboCup Rescue Victim Dataset
2018 IEEE International Symposium on Safety Security and Rescue Robotics (SSRR), 2018Co-Authors: Peter Lorenz, Gerald SteinbauerAbstract:In this paper, we introduce a victim dataset for the RoboCup Rescue competitions. The RoboCup Rescue robots have to collect points within several disciplines, e.g. a search task within an area to survey simulated baby doll (victim). When a robot comes across a victim, a Heat Detector does not completely proof if this is a living being and not just a Heat emitting somewhat else. Further investigations are necessary so that a face detection could prove the existence of a victim. Lots of face detection approaches can be found in literature, which manly are used for human face recognition. These cannot be straightforward used for victim faces which are, in case of the RoboCup Rescue competitions, typically dolls. Thus we present the results of standard approaches and developed an own approach via bag-of-visual-words (BoVW).
Peter Lorenz - One of the best experts on this subject based on the ideXlab platform.
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SSRR - The RoboCup Rescue Victim Dataset
2018 IEEE International Symposium on Safety Security and Rescue Robotics (SSRR), 2018Co-Authors: Peter Lorenz, Gerald SteinbauerAbstract:In this paper, we introduce a victim dataset for the RoboCup Rescue competitions. The RoboCup Rescue robots have to collect points within several disciplines, e.g. a search task within an area to survey simulated baby doll (victim). When a robot comes across a victim, a Heat Detector does not completely proof if this is a living being and not just a Heat emitting somewhat else. Further investigations are necessary so that a face detection could prove the existence of a victim. Lots of face detection approaches can be found in literature, which manly are used for human face recognition. These cannot be straightforward used for victim faces which are, in case of the RoboCup Rescue competitions, typically dolls. Thus we present the results of standard approaches and developed an own approach via bag-of-visual-words (BoVW).
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The RoboCup Rescue Victim Dataset
2018 IEEE International Symposium on Safety Security and Rescue Robotics (SSRR), 2018Co-Authors: Peter Lorenz, Gerald SteinbauerAbstract:In this paper, we introduce a victim dataset for the RoboCup Rescue competitions. The RoboCup Rescue robots have to collect points within several disciplines, e.g. a search task within an area to survey simulated baby doll (victim). When a robot comes across a victim, a Heat Detector does not completely proof if this is a living being and not just a Heat emitting somewhat else. Further investigations are necessary so that a face detection could prove the existence of a victim. Lots of face detection approaches can be found in literature, which manly are used for human face recognition. These cannot be straightforward used for victim faces which are, in case of the RoboCup Rescue competitions, typically dolls. Thus we present the results of standard approaches and developed an own approach via bag-of-visual-words (BoVW).
David G. Lilley - One of the best experts on this subject based on the ideXlab platform.
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Application of BRANZFIRE to a Variety of Realistic Burning Items in a Room Fire with Smoke Detectors and Sprinkler Activation Times
10th International Energy Conversion Engineering Conference, 2012Co-Authors: Mujeer A. Mohammed, Avinash Raavi, David G. LilleyAbstract:Lilley & Associates, 7221 Idlewild Acres, Stillwater, Oklahoma 74074 The BRANZFIRE code is an efficient zone type computer fire modeling software used to simulate fires in multi room structures. Its name is an abbreviation for Building Research Association of New Zealand FIRE model. This modeling software calculates various important things as a specified but constrained fire progresses, like the upper layer and lower layer temperatures and thicknesses, and optical smoke density. The time to activation of a smoke Detector, Heat Detector or sprinkler is also calculated, and how this is affected by position and activation parameters may be determined. The software has got a wide variety of predefined fires and many other fires in their fire database (University of Canterbury, New Zealand online database). BRANZFIRE is used to model the fire dynamics of a variety of fires in a single room, and determine the activation time for smoke Detectors located on the ceiling at various locations (every half meter) to the side of the fire. The activation time may also be calculated for Heat Detectors and sprinklers at the same locations, using standard default values for the response time index RTI, C-factor, and actuation temperature. It is known that BRANZFIRE under predicts the activation times of smoke Detectors but over predicts the activation times of sprinklers, as stated in the validation provided by the computer code developers. The code is applied here to the calculation of smoke Detector and sprinkler response time calculation with a range of fires in a single room, with closed door, and the fire located midway along one of the walls.
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BRANZFIRE: Smoke Detector and Sprinkler Activation Times with Liquid Pool Fires
50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2012Co-Authors: Avinash Raavi, David G. LilleyAbstract:BRANZFIRE is used to model the fire dynamics of liquid pool (pan) fires in a single room, and determine the activation time for smoke Detectors located on the ceiling at various locations (every half meter) to the side of the fire. The activation time is also calculated for Heat Detectors and sprinklers at the same locations, and is also presented, using standard default values for the response time index RTI, C-factor, and actuation temperature. The BRANZFIRE code is an efficient zone type computer fire modeling software used to simulate fires in multi room structures. Its name is an abbreviation for Building Research Association of New Zealand FIRE model. This modeling software calculates various important things as a specified but constrained fire progresses, like the upper layer and lower layer temperatures and thicknesses, and optical smoke density. The time to activation of a smoke Detector, Heat Detector or sprinkler is also calculated, and how this is affected by position and activation parameters may be determined. The software has got a wide variety of predefined fires and many other fires in their fire database (University of Canterbury, New Zealand online database). BRANZFIRE under predicts the activation times of smoke Detectors but over predicts the activation times of sprinklers, as stated in the validation provided by the computer code developers. It is applied here to the calculation of smoke Detector and sprinkler response time calculation with a variety of liquid pool (pan) fires in a single room, with closed door, and the fire located midway along one of the walls.
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Smoke Detector and Sprinkler Activation Times with Gas Burner Fires using BRANZFIRE
9th Annual International Energy Conversion Engineering Conference, 2011Co-Authors: Avinash Raavi, David G. LilleyAbstract:*† Lilley & Associates, 7221 Idlewild Acres, Stillwater, Oklahoma 74074 BRANZFIRE is an efficient zone type computer fire modeling software used to simulate fires in multi room structures. Its name is an abbreviation for Building Research Association of New Zealand FIRE model. This modeling software can calculate various important variables involved in a fire scenario like the upper layer and lower layer temperatures, optical smoke density, smoke Detector, Heat Detector and sprinkler activation times. It has got a wide variety of predefined fires and many other fires in their fire database (University of Canterbury, New Zealand online database). BRANZFIRE under predicts the activation times of smoke Detectors but over predicts the activation times of sprinklers, as stated in the validation provided by the computer code developers. It is applied here to the calculation of smoke Detector and sprinkler response time calculation with a variety of standard gas burner fires. A single room, closed door, wall fire scenario is used to run various simulations using BRANZFIRE computer fire modeling software. Smoke Detectors and sprinklers are located on the ceiling every 0.5 meters away from directly above the fire. Three different smoke Detector sensitivities are considered in all cases, to exemplify the effect of sensitivity on the activation times. Sprinkler sensitivity was held constant at standard settings of activation temperature, C-factor and response time index RTI. Activation times of smoke Detectors and sprinkler operation are calculated for a varity of standard gas burner fires and compared with corresponding times from standard t 2 -fires with varying Heat release rates: the ultra-fast, fast, medium and slow fires. Results obtained from BRANZFIRE simulation indicate that the constrained Heat release rate falls below the specified Heat release rate in most of the cases, because of lack of availability of oxygen as the smoke descends in the closed room. Smoke Detector activation times depend upon the rapidity of fire development, Detector sensitivity, and proximity of the Detector to the location of the fire. When Detectors are closer to the fire, Detector sensitivity plays a less important role.
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BRANZFIRE: Application to Realistic Burning Items in a Room Fire with Smoke Detectors and Sprinkler Activation Times
49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2011Co-Authors: Avinash Raavi, David G. LilleyAbstract:Smoke Detectors, Heat Detectors and sprinklers are devices associated with fire detection, with smoke Detectors being the most widely used in homes. BRANZFIRE is an efficient zone type computer fire modeling software used to simulate fires in multiroom structures. This modeling software can calculate various important variables involved in a fire scenario like the upper layer and lower layer temperatures, optical smoke density, smoke Detector, Heat Detector and sprinkler activation times. A single room, closed door, wall fire scenario is used to run various simulations. The fire is located halfway along the shorter wall and the exterior door is closed. Smoke and Heat Detectors are located on the ceiling every 0.5 meters away from directly above the fire. Activation times of smoke Detectors and sprinklers are calculated for standard t 2 -fires with varying Heat release rates: the ultra-fast, fast, medium and slow fires. The model is extended to calculate activation times of smoke Detectors and sprinklers with real-world fires for six furniture fire. Three different smoke Detector sensitivities are considered in all cases, to exemplify the effect of sensitivity on the activation times. Results obtained from BRANZFIRE simulation indicate that the constrained Heat release rate falls below the specified Heat release rate in most of the cases, because of lack of availability of oxygen as the smoke descends in the closed room. Smoke Detector activation times were compared, for different fires, based on Detector sensitivity. It was observed that smoke Detector activation times are much lower than Heat Detector and sprinkler activation times. In the case of medium and slow fires, smoke Detector sensitivity plays a more important role in detection times than with ultra-fast and fast fires. This is especially so when the Detector is further away from the fire object. Results are also presented and discussed for six different typical items of furniture.
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Two-Room Structural Fire Calculations with the FDS Computer Code for Smoke and Heat Detector Response
48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition, 2010Co-Authors: Siddarth Kotha, David G. LilleyAbstract:The application of Fire Dynamics Simulator FDS code to two-room structural fires with smoke Detectors and Heat Detectors is described. The code solves the time-dependent partial differential equations PDEs on a 3-D grid system covering the interior of the structure. Results therefore permit properties like velo cities, temperature, species, etc to vary throughout the 3-D space, and indeed models for fire growth and development are included to permit fire development that depends on the local items available for burning. The fine details of the interior environment can be ac commodated within the model. A series of applications are described, and results are vividly illustrated th at show the volume, temperature and location of combustion product species evolving from the fire. The influence of open and closed exterior door to the outside on the simulation results of a tworoom structure has been studied. Ultra-fast , fast and medium fires are considered. Smoke Detector activation is via the four parameter Cleary model using local velocity and optical density of the nearby smoke. Activation times are obtained and discussed for smoke Detectors located in many places. In each ro om, 16 smoke Detectors are located sequentially on the side wall, 3 smoke Detectors located just above the doorway, and another smoke Detector located top-dead-center on the ceiling. Similarly, the activation times of 18 Heat Detectors, 5 each on the side wall, 3 just above the doorway and another at the top-deadcenter are studied. These are the exact same lo cations as used with the smoke Detectors. Heat Detector activation times, based on their positions and their controlling parameters, are calculated for the same specified fires as was used with the smoke Detectors.
Ramanathan K. Kasimanickam - One of the best experts on this subject based on the ideXlab platform.
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Fertility in Angus cross beef cows following 5-day CO-Synch + CIDR or 7-day CO-Synch + CIDR estrus synchronization and timed artificial insemination
Theriogenology, 2013Co-Authors: W.d. Whittier, John F. Currin, Holly Schramm, Sarah Holland, Ramanathan K. KasimanickamAbstract:Abstract The present study determined whether a 5-day CO-Synch + controlled internal drug release (CIDR) protocol with two doses of PGF2α would improve timed artificial insemination (AI) pregnancy rate compared with 7-day CO-Synch + CIDR protocol in beef cows. Angus cross beef cows ( N = 1817) at 12 locations were randomly assigned to 5-day CO-Synch + CIDR or 7-day CO-Synch + CIDR groups. All cows received 100 μg of GnRH and a CIDR insert on Day 0. Cows ( n = 911) in the 5-day CO-Synch + CIDR group received two doses of 25 mg PGF, the first dose given on Day 5 at CIDR removal and the second dose 6 hours later, and 100 μg GnRH on Day 8 and were inseminated concurrently, 72 hours after CIDR removal. Cows ( n = 906) in 7-day CO-Synch + CIDR group received 25 mg of PGF at CIDR removal on Day 7, and 100 μg GnRH on Day 10 and were inseminated concurrently, 66 to 72 hours after CIDR removal. All cows were fitted with a Heat Detector aid at CIDR removal and were observed twice daily until insemination for estrus and Heat Detector aid status. Accounting for estrus expression at or before AI (P 6 − 55.8%]. The mean AI pregnancy rate difference between treatment groups and projected economic outcome varied among locations. In conclusion, cows synchronized with the 5-day CO-Synch + CIDR protocol had greater AI pregnancy rate than those that received the 7-day CO-Synch + CIDR protocol.
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Fertility in Angus cross beef cows following 5-day CO-Synch þ CIDR or 7-day CO-Synch þ CIDR estrus synchronization and timed artificial insemination
2013Co-Authors: W.d. Whittier, John F. Currin, Holly Schramm, Sarah Holland, Ramanathan K. KasimanickamAbstract:The present study determined whether a 5-day CO-Synch þ controlled internal drug release (CIDR) protocol with two doses of PGF2a would improve timed artificial insemination (AI) pregnancy rate compared with 7-day CO-Synch þ CIDR protocol in beef cows. Angus cross beef cows (N ¼ 1817) at 12 locations were randomly assigned to 5-day COSynch þ CIDR or 7-day CO-Synch þ CIDR groups. All cows received 100 mg of GnRH and a CIDR insert on Day 0. Cows (n ¼ 911) in the 5-day CO-Synch þ CIDR group received two doses of 25 mg PGF, the first dose given on Day 5 at CIDR removal and the second dose 6 hours later, and 100 mg GnRH on Day 8 and were inseminated concurrently, 72 hours after CIDR removal. Cows (n ¼ 906) in 7-day CO-Synch þ CIDR group received 25 mg of PGF at CIDR removal on Day 7, and 100 mg GnRH on Day 10 and were inseminated concurrently, 66 to 72 hours after CIDR removal. All cows were fitted with a Heat Detector aid at CIDR removal and were observed twice daily until insemination for estrus and Heat Detector aid status. Accounting for estrus expression at or before AI (P 6 � 55.8%]. The mean AI pregnancy rate difference between treatment groups and projected economic outcome varied among locations. In conclusion, cows synchronized with the 5-day COSynch þ CIDR protocol had greater AI pregnancy rate than those that received the 7-day CO-Synch þ CIDR protocol.
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Effects of one versus two doses of prostaglandin F2alpha on AI pregnancy rates in a 5-day, progesterone-based, CO-Synch protocol in crossbred beef heifers.
Theriogenology, 2011Co-Authors: Chris Peterson, A. Alkar, S. Smith, S. Kerr, John Hall, Dale A. Moore, Ramanathan K. KasimanickamAbstract:Abstract The present study determined whether a 5-d progesterone-based CO-Synch protocol with a single dose of prostaglandin F2α (PGF) at progesterone withdrawal on Day 5, would yield a timed AI pregnancy rate similar to two doses of PGF given 6 h apart on Day 5. Angus cross beef heifers (N = 562) at six locations were used. All heifers received 100 µg of gonadorelin hydrochloride (GnRH) and a controlled internal drug release (CIDR) insert on Day 0. Within farm, heifers were randomly allocated to receive one dose of 25 mg dinoprost (PGF) at CIDR removal on Day 5 (1 PGF; N = 264), or two doses of 25 mg PGF, with the first dose given on Day 5 at CIDR removal, and the second dose 6 h later (2 PGF; N = 298). Most heifers (N = 415) received a Heat Detector patch at CIDR removal. After CIDR removal, heifers were observed twice daily through Day 7 for estrus and Heat Detector aid status was recorded. On Day 8, heifers were given 100 µg of GnRH, Heat Detector aid status was recorded, and heifers were inseminated approximately 72 h after CIDR removal. Accounting for significant variables such as location (P
