Mean Emission Values Research Articles

Experimental Measurement of Emissivity of Polished Steel Strips from a Continuous Annealing Line.

The long-term use of steel strip in various industries makes it an important semi-finished product, which makes it necessary to improve its chemical composition and mechanical properties, reduce its thickness and weight, expand the range of new types of steel strip and increase its production. This entails a large number of technological operations dependent on precise temperature measurement and control. In some industrial plants, the steel strip is in continuous motion, which makes the use of contact measuring devices impossible. When using non-contact measuring devices such as pyrometers or thermal imaging cameras, the emissivity of the materials being measured is a problematic parameter, as setting an incorrect emissivity value to the measuring device results in inaccurate temperature readings. The essence of this research was to establish a measurement method and to perform experimental measurements of the emissivity of a polished steel strip used in a continuous annealing line, the subsequent processing of the data from these measurements and their evaluation. The emissivity measurements were carried out for 5 types of steel strip of different parameters, while the measurement itself was carried out in the long wavelength range of 7.5-14 µm and at strip temperatures of 100-300 °C. Depending on the type of steel strip, the mean emissivity values ranged from 0.0835- to 0.1143. The emissivity of the steel strip increased with increasing strip temperature, and it was not a linear dependence. The emissivity values determined in this research could be applied to measuring equipment in actual production, which could improve the accuracy of temperature measurement in the heat treatment of polished steel strip. Thermal camera measurements in the long wavelength range, taking thermal images and their processing and determining the emissivity value of polished steel strips are the parts of this research that make it different from other already published research.

Flue Gas Emissions and Performance Evaluation of Small-scale Solid Waste Incinerators at Njokerio and Ng’ondu in Njoro, Kenya

Solid waste management is challenging and incineration technique is more preferred to other methods in reduction of mass and volume, removal of odour and energy recovery in both industrial and residential environments. The challenges facing residents at Njokerio, Ng’ondu and Green Valley estates in Njoro, Kenya included poorly designed open-wastes collection systems, exceeding incinerator loading rates and inappropriate operating temperatures. It also include inadequate design specifications, poorly mixed solid wastes with high moisture contents resulting to high emissions of noxious heavy dense smoke. The aim of this study was to evaluate factors influencing flue gas emissions and performance of small-scale incinerators. Data collected were statistically analysed to determine trends, means, F-values and Least Significant Different (LSD) at . Wastes incineration at varying moisture contents (MC) from 15 to 75% produced mean emission values for carbon monoxide (CO), carbon dioxide (CO2), and hydrocarbon (HC) ranging between 5 and 11 ppm, 5 and 14%, and from 508 to 1168 ppm, respectively. Varying the incinerator loading rates from 15 to 75 kg/h yielded means CO ranging between 5 and 12 ppm, CO2 from 5 to 14%, and HC between 252 and 1096 ppm. Waste incineration at varying operating temperature levels from 180 to 900°C contributed to mean emissions for CO, CO2 and HC ranging from 14 to 5 ppm, 15 to 6% and 1253 to 316 ppm, respectively. The Egerton University dispensary incinerator had the best incineration performance compared to the rest. High moisture contents, overloaded incinerators and low operating temperature levels contributed to high emission levels of flue gases leading to dark and dense smoke which resulted into incomplete wastes combustion indicating poor incineration performance. Wastes incineration at low loading rates, low moisture contents and high operating temperatures produced white and fine bottom ash, low levels of carbon, implying complete wastes combustion.

Assessment of Bandaged Burn Wounds Using Porcine Skin and Millimetric Radiometry.

This paper describes the experimental setup and measurements of the emissivity of porcine skin samples over the band of 80–100 GHz. Measurements were conducted on samples with and without dressing materials and before and after the application of localized heat treatments. Experimental measurements indicate that the differences in the mean emissivity values between unburned skin and burned damaged skin was up to ~0.28, with an experimental measurement uncertainty of ±0.005. Measured differences in the mean emissivity values between unburned and burn damaged skin increases with the depth of the burn, indicating a possible non-contact technique for assessing the degree of a burn. The mean emissivity of the dressed burned skin was found to be slightly higher than the undressed burned skin, typically ~0.01 to ~0.02 higher. This indicates that the signature of the burn caused by the application of localized heat treatments is observable through dressing materials. These findings reveal that radiometry, as a non-contact method, is capable of distinguishing between normal and burn-damaged skin under dressing materials without their often-painful removal. This indicates the potential of using millimeter wave (MMW) radiometry as a new type of medical diagnostic to monitor burn wounds.

Investigations on energy transfer and tunable luminescence spectra for single, co-doped and tri-doped RE3+(RE3+= Dy3+, Sm3+ and Eu3+) activated Sr1.99Bi0.01CeO4 phosphors

The Sr1.99-xBi0.01CeO4:xRE3+ (RE3+ = Dy3+, Sm3+ and Eu3+, x = 0 and 0.03) single, co-doped and tri-doped phosphors synthesized by solid state reaction technique and their structure analysed by X-ray powder diffraction technique (XRD). The results shows that the Dy3+,Sm3+, Eu3+, Dy3+/Sm3+, Sm3+/Eu3+, Dy3+/Eu3+, and Dy3+/Sm3+/Eu3+ ions are effectively studded into the host lattice site without changing the structure of the host. The luminescence and energy transfer properties of the Sr1.99-xBi0.01CeO4:xRE3+ have been investigated for single, co-doped and tri-doped phosphors under each of the 387 nm (Dy3+: 6H15/2 → 4I13/2), 409 nm (Sm3+: 6H5/2 → 6P3/2) and 466 nm (Eu3+: 7F0→5L6) excitation levels wherein the mean emission values reportedly seem to be 572, 651 and 615 nm respectively. The chromaticity coordinates and decay time of the synthesized materials are also examined.

ELECTROMAGNETIC SIGNATURES OF HUMAN SKIN IN THE MILLIMETER WAVE BAND 80-100 GHZ

Due to changes in global security requirements attention is turning to new means by which anomalies on the human body might be identified. For security screening systems operating in the millimeter wave band anomalies can be identified by measuring the emissivities of subjects. As the interaction of millimeter waves with the human body is only a fraction of a millimeter into the skin and clothing has a small, but known effect, precise measurement of the emission and reflection of this radiation will allow comparisons with the norm for that region of the body and person category. A technique to measure the human skin emissivity in vivo over the frequency band 80 GHz to 100 GHz is developed and described. The mean emissivity values of the skin of a sample of 60 healthy participants (36 males and 24 females) measured using a 90GHz calibrated radiometer were found to range from 0.17±0.005 to 0.68±0.005. The lower values of emissivity are a result of measuring particularly thin skin on the inner wrist, volar side of the forearm, and back of hand, whereas higher values of emissivity are results of measuring thick skin on the outer wrist, dorsal surface of the forearm, and palm of hand. The mean differences in the emissivity between Asian and European male participants were calculated to be in the range of 0.04 to 0.11 over all measurement locations. Experimental measurements of the emissivity for male and female participants having normal and high body mass index indicate that the mean differences in the emissivity are in the range of 0.05 to 0.15 for all measurement locations. These results show the quantitative variations in the skin emissivity between locations, gender, and individuals. The mean differences in the emissivity values between dry and wet skin on the palm of hand and back of hand regions were found to be 0.143 and 0.066 respectively. These results confirm that radiometry can, as a non-contact method, identify surfaces attached to the human skin in tens of seconds. These results indicate a route to machine anomaly detection that may increase the through-put speed, the detection probabilities and reduce the false alarm rates in security screening portals.

Ammonia and greenhouse gas emissions from an enriched cage laying hen facility

Ammonia, methane, nitrous oxide and carbon dioxide emissions were measured during a complete production cycle in an enriched cage laying hen facility under Oceanic climate conditions. Continuous monitoring of gas concentration, ventilation rate and environmental parameters were conducted from April 2012 to September 2013. The seasonal and diurnal pattern of gas emissions was analysed. Seasonality effect was found for NH 3 emission, showing an average emission of 144.9 mg d −1 hen −1 and 90.3 mg d −1 hen −1 in summer and winter, respectively. On the contrary, diurnal pattern of NH 3 emission did not differ between these seasons. For CO 2 , mean emission values did not show seasonality, although the diurnal pattern differed between winter and summer. Results obtained for CH 4 and N 2 O emissions did not provide sufficient evidence to determine either seasonality or diurnal effect on these gases. An NH 3 emission factor of 7% of total N in manure was defined for this system. These losses increased at higher ventilation rates and lower belt cleaning frequencies. Thus, NH 3 mitigation strategies at housing level should consider both parameters. Further studies would be necessary to determine how these factors regulate NH 3 emission at laying hen houses.

Quantifying Uncertainties in Land-Surface Microwave Emissivity Retrievals

Uncertainties in the retrievals of microwave land-surface emissivities are quantified over two types of land surfaces: desert and tropical rainforest. Retrievals from satellite-based microwave imagers, including the Special Sensor Microwave Imager, the Tropical Rainfall Measuring Mission Microwave Imager, and the Advanced Microwave Scanning Radiometer for Earth Observing System, are studied. Our results show that there are considerable differences between the retrievals from different sensors and from different groups over these two land-surface types. In addition, the mean emissivity values show different spectral behavior across the frequencies. With the true emissivity assumed largely constant over both of the two sites throughout the study period, the differences are largely attributed to the systematic and random errors in the retrievals. Generally, these retrievals tend to agree better at lower frequencies than at higher ones, with systematic differences ranging 1%-4% (3-12 K) over desert and 1%-7% (3-20 K) over rainforest. The random errors within each retrieval dataset are in the range of 0.5%-2% (2-6 K). In particular, at 85.5/89.0 GHz, there are very large differences between the different retrieval datasets, and within each retrieval dataset itself. Further investigation reveals that these differences are most likely caused by rain/cloud contamination, which can lead to random errors up to 10-17 K under the most severe conditions.

Volatile Organic Compounds Emitted during the Kiln Drying of Southern Pine Utility Poles

Southern pine is the most common species used for utility poles in the United States. However, information regarding air emissions from pole drying is very limited. With respect to drying, poles have longer lengths, resulting in limited end-grain exposure, higher final moisture content, and lower ratios of surface area to volume, and typically southern pine poles have higher amounts of heartwood compared with southern pine lumber because of pole age. For this research, several green southern pine utility pole bolts were obtained and cut into matched kiln charges that contained sapwood only, mostly sapwood, mostly heartwood, and knotty material. Eight charges were dried at 230°F dry bulb with at least a 50°F wet bulb depression until the poles reached a moisture content of 30 percent at a depth 3 inches from the surface. Volatile organic emissions from the kiln charges were measured using federal guidelines. The mean emission values from the all sapwood, mostly sapwood, mostly heartwood, and knotty wood kiln charges were 3.59, 3.52, 2.64, and 3.65 pounds of volatile organic emissions per thousand board feet, respectively. The emissions of the sapwood, mostly sapwood, and knotty charges were similar to clear lumber emission values. The emissions from the knotty charges were less than emissions from knotty lumber. The results suggest that heartwood-rich utility poles release much less organic emissions than heartwood lumber, perhaps because of the band of sapwood that always surrounds the heartwood in poles as opposed to lumber where the heartwood is often exposed at the surface.

Integrating Corine Land Cover data and Landsat TM for surface emissivity definition: application to the urban area of Athens, Greece

This study examines the potential of the combined use of the land cover/land use information provided by the Corine Land Cover (CLC) database with Landsat satellite data for the definition and quantitative correlation of emissivity with various land covers and land uses that describe a certain territory. Surface emissivity in the 10.5–12.5 µm wavelength range is derived using Landsat data and the Normalized Difference Vegetation Index Thresholds method (NDVITHM), whereas mean emissivity values for selected urban/non‐urban land cover types are estimated by integrating the emissivity image with the land cover vector data. The method is applied to the greater Athens area, Greece, in order to estimate the emissivity of various land cover types found within the urban setting. Analysis of variance (ANOVA) indicates statistically significant differences in emissivity associated with different land cover types. Furthermore, statistical results demonstrate that the method is very effective and can provide emissivity values of different land cover types with good accuracy and therefore can quantitatively link emissivity with surface type.

Emission of nitric oxide from soils and termite nests in a Trachypogon savanna of the Orinoco basin

Nitric oxide fluxes from soils in the Trachypogon savanna of the Orinoco basin were determined during the dry season using the static chamber method. The emission from dry soils fluctuated from 0.4 to 3 ng N m−2 s−1 and increased up to 25 ng N m−2 s−1 after moderate watering or light rain-falls (1 to 5 mm). The mean emission values are up to 6 times lower than one observed earlier at the Chaguaramas site, but up to 10 times higher than one recorded at the Guri site, indicating an important spatial variability in NO fluxes of the Venezuelan savanna region. The changes observed after the addition of nitrogen to the soil, in the form of ammonium and/or nitrate, indicate a high denitrification potential in this acidic soil. Burning of the surface vegetation produced an increase by a factor of 10 in the emission rate of NO, but the effect was relatively short in time, about 5 days. It was estimated for the savanna region that burning increases the total NO soil emission during the dry season by 15% compared to the unburnt case. Soils with termite nests emit 10 times more NO than soil without nests, but the contribution from this source is less than 2% of the total savanna soil flux.

Speciated hydrocarbon emissions from vehicles operated over the normal speed range on the road

A description is given of techniques used to develop the emission factors for individual hydrocarbons (HCs) in the emissions from 25 vehicles driven over a series of routes covering normal driving conditions on U.K. roads. Mean emission values as a function of speed are presented and a variation in the proportion of components over the speed range is noted. The results are discssed in the context of continuing studies of U.K. air quality, and the vehicle exhaust to individual ambient HCs at two sites in London is deduced.

Observations of Cloud Infrared Effective Emissivity

Abstract This paper presents mean greybody infrared effective emissivity values of clouds deduced from 300 International Quiet Sun Year (IQSY) radiometersonde ascents. The cloud effective emissivity data are presented for two latitude regions: midlatitude and tropical. Mean cloud effective emissivity values for the surface to 300 mb layer ranged from 0.41 to 0.64 for the midlatitude data and from 0.54 to 0.84 for the tropical data. Clouds in the pressure interval from 400 to 600 mb exhibited the largest mean emissivity values. These data should he very useful for incorporation of realistic cloud radiative properties into modeling of atmospheric dynamics and climate.

Cytophotometric Data on Fluorochromed Cervical Cells<xref ref-type="fn" rid="FN1">2</xref>

A simplified fluorophotometric device for measuring the light emission of the whole-cell area of single isolated cells is described. Ehrlich ascites carcinoma cells stained with the basic fluorochrome acridine orange were used for a model experiment. The sensitivity of the used photomultiplier 1P21 for the green-yellow emitted by the nuclear area was about 4 times greater than that for the metachromatic red of the cytoplasmic and nucleolar ribonucleic acid. Galvanometer readings over concentric cell areas of varying diameters showed that nuclear emission was mainly responsible for the total recorded fluorescence intensity. Photometric data obtained on single fluorochromed cervical cells gave mean emission values approximately 2 times higher for abnormal than for corresponding normal cells. Emission values of abnormal cells were distinctly above the level of a dividing line at 36.2 emission units and were well separated from normal cells. The differential staining of nucleus and cytoplasm by a basic fluorochrome with well-delineated nucleo-cytoplasmic boundaries is of advantage for detection of cellular atypia by visual observation. In addition, cytophotometric data can yield valuable evidence in closer identification and separation of degrees of cellular abnormalities, especially where cytologic classification and tissue findings are not conclusive.