Journal articles: 'Light emission measurement'

1

Durán Ramiro, M. Teresa, and Eduardo García-Toraño. "Measurement of light emission in scintillation vials." Review of Scientific Instruments 76, no. 9 (September 2005): 093115. http://dx.doi.org/10.1063/1.2044627.

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Wang, Gang, Chao Qian, Guoliang Yang, Ligui Nan, and Haige Yu. "Verification of PEMS measurement accuracy based on light vehicle emission test system." E3S Web of Conferences 268 (2021): 01003. http://dx.doi.org/10.1051/e3sconf/202126801003.

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For the requirements of the portable emission measurement system (PEMS) measurement accuracy for limits and measurement methods for emissions from light-duty vehicles(CHINA 6), based on the light-duty vehicle emission test system in steady-state conditions and WLTC conditions for PEMS gaseous pollutants, mass flow rate , particle number (PN) verify accuracy of measurement. The results showed that the relative measurement errors of CO, CO2, NOx, fuel consumption and mass flow rate were −5.49%, 2.53%, 10.55%, 2.09% and −2.79%. The relative measurement errors of CO, CO2, NOx, fuel consumption and PN under WLTC condition were 6.67%, 2.54%, 12.96%, 2.37% and −16.08%, which meeting the requirements of the regulations.

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KADOWAKI, Daisuke, Takaki ITAYA, and Hideo SHOJI. "20204 An Analysis of Preflame Reaction Light Emission Behavior in Autoignition Using Light Emission Measurement." Proceedings of Conference of Kanto Branch 2006.12 (2006): 383–84. http://dx.doi.org/10.1299/jsmekanto.2006.12.383.

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JR., W. R. FORBUS, S. D. SENTER, and RUEL L. WILSON. "Measurement of Tomato Maturity by Delayed Light Emission." Journal of Food Science 50, no. 3 (May 1985): 750–53. http://dx.doi.org/10.1111/j.1365-2621.1985.tb13788.x.

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FORBUS, W. R., S. D. SENTER, and H. T. CHAN. "Measurement of Papaya Maturity by Delayed Light Emission." Journal of Food Science 52, no. 2 (March 1987): 356–59. http://dx.doi.org/10.1111/j.1365-2621.1987.tb06612.x.

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Hakola, H., V. Tarvainen, J. Bäck, H. Ranta, B. Bonn, J. Rinne, and M. Kulmala. "Seasonal variation of mono- and sesquiterpene emission rates of Scots pine." Biogeosciences 3, no. 1 (March 13, 2006): 93–101. http://dx.doi.org/10.5194/bg-3-93-2006.

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Abstract. The seasonal variation of mono-and sesquiterpene emission rates of Scots pine was measured from April to October in 2004. The emission rates were measured daily in the afternoons with the exception of weekends. Emissions were measured from two branches; one of them was debudded in May (branch A), while the other was allowed to grow new needles (branch B). The monoterpene emission pattern remained almost constant throughout the measurement period, Δ3-carene being the dominant monoterpene (50-70% of the VOC emission). The standard monoterpene emission potential (30°C) was highest during early summer in June (the average of the two branches 1.35 µg g-1h-1) and lowest during early autumn in September (the average of the two branches 0.20 µg g-1h-1. The monoterpene emission potential of branch A remained low also during October, whereas the emission potential of branch B was very high in October. The sesquiterpenes were mainly emitted during mid summer, the dominant sesquiterpene being β-caryophyllene. Branch A had a higher sesquiterpene emission potential than branch B and the emission maximum occurred concomitant with the high concentration of airborne pathogen spores suggesting a potential defensive role of the sesquiterpene emissions. The sesquiterpene emissions were well correlated with linalool and 1,8-cineol emissions, but not with monoterpenes. Sesquiterpene and 1,8-cineol emissions were equally well described by the temperature dependent and the temperature and light dependent algorithms. This is due to the saturation of the light algorithm as the measurements were always conducted during high light conditions.

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Hakola, H., V. Tarvainen, J. Bäck, H. Ranta, B. Bonn, J. Rinne, and M. Kulmala. "Seasonal variation of mono- and sesquiterpene emission rates of Scots pine." Biogeosciences Discussions 2, no. 6 (November 10, 2005): 1697–717. http://dx.doi.org/10.5194/bgd-2-1697-2005.

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Abstract. The seasonal variation of mono-and sesquiterpene emission rates of Scots pine was measured from April to October in 2004. The emission rates were measured daily in the afternoons with the exception of weekends. Emissions were measured from two branches; one of them was debudded in May (branch A), while the other was allowed to grow new needles (branch B). The monoterpene emission pattern remained almost constant throughout the measurement period, Δ3-carene being the dominant monoterpene (50–70% of the VOC emission). The standard monoterpene emission potential was highest during early summer in June (the average of the two branches 0.55 μg−1(dw) h−1) and lowest during early autumn in September (the average of the two branches 0.12 μg g−1(dw) h−1). The monoterpene emission potential of branch A remained low also during October, whereas the emission potential of branch B was very high in October. The sesquiterpenes were mainly emitted during mid summer, the dominant sesquiterpene being β-caryophyllene. Branch A had a higher sesquiterpene emission potential than branch B and the emission maximum occurred concomitant with the high concentration of airborne pathogen spores indicating the defensive role of the sesquiterpene emissions. The sesquiterpene emissions were well correlated with linalool and 1,8-cineol emissions, but not with monoterpenes. Sesquiterpene and 1,8-cineol emissions were equally well described by the temperature dependent and the temperature and light dependent algorithms. This is due to the saturation of the light algorithm as the measurements were always conducted during high light conditions.

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BIELACZYC, Piotr, Andrzej SZCZOTKA, and Joseph WOODBURN. "An overview of particulate matter emissions from modern light duty vehicles." Combustion Engines 153, no. 2 (May 1, 2013): 101–8. http://dx.doi.org/10.19206/ce-117007.

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This paper presents a comparison of particle mass and number emissions from different types of vehicles with spark-ignition (SI) engines, with MPI and DI fuelling systems and compression-ignition (CI) engines with DI fuelling system with/without Diesel particles filters (DPF). The methodology of particulate mass and particle number emissions measurement with a full flow dilution tunnel for LDD engines and particulate sampling system is described. The results of measurements performed according to Euro 5/Euro 6 requirements for PC and LDV vehicles are presented, as performed on the chassis dynamometer in the Exhaust Emission Laboratory of BOSMAL Automotive Research and Development Institute (in Bielsko-Biala), Poland.

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Wang, Zhihong, Penghui Wu, Nenghui Yu, Yuanjun Zhang, and Zhijun Wang. "Analysis of the influence of RDE test data processing methods on the emission results of China 6 light duty vehicles." E3S Web of Conferences 268 (2021): 01022. http://dx.doi.org/10.1051/e3sconf/202126801022.

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The CO2 moving average window(MAW) method is used to process RDE (real drive emissions) emissions data in China 6 light duty vehicle emissions regulations, while the Euro 6 light duty vehicle emission regulations allow to use both of MAW and power binning(PB) method to deal with RDE emission data. In order to study the difference between the two data processing methods and analyze the differences in the emission results, 10 different types of light duty vehicles are conducted RDE test with PEMS (portable emissions measurement system), and the test data are processed by the two methods separately. The results show that there is a little difference between MAW and PB, while both of them can satisfy the vehicle emission assessment. The PB method calculates the emission factors higher than the MAW method. After removing the cold start and idle condition data, the results of PB is similar to MAW. Besides, reducing the average speed limit of urban working conditions in PB has a greater impact on the urban driving condition emission factor, but less on the whole cycle emission factor.

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Lee, SoDuk, Carl R. Fulper, Daniel Cullen, Joseph McDonald, Antonio Fernandez, Mark H. Doorlag, Lawrence J. Sanchez, and Michael Olechiw. "On-Road Portable Emission Measurement Systems Test Data Analysis and Light-Duty Vehicle In-Use Emissions Development." SAE International Journal of Electrified Vehicles 9, no. 2 (December 31, 2020): 111–31. http://dx.doi.org/10.4271/14-09-02-0007.

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Portable emission measurement systems (PEMS) [1] are used by the US Environmental Protection Agency (EPA) to measure gaseous and particulate matter mass emissions from vehicles in normal, in-use, on-the-road, and “real-world” operations to support many of its programs. These programs include vehicle modeling, emissions compliance, regulatory development, emissions inventory development, and investigations of the effects of real, in-use driving conditions on NOx, CO2, and other regulated pollutants. This article discusses EPA’s analytical methodology for evaluating light-duty vehicle energy and EU Real Driving Emissions (RDE). A simple, data-driven model was developed and validated using measured PEMS emissions test data. The work also included application of the EU RDE procedures and comparison to the PEMS test methodologies and FTP and other chassis dynamometer test data used by EPA for characterizing in-use light- and heavy-duty vehicle emissions. This work was conducted as part of EPA’s participation in the development of UNECE Global Technical Regulations and also supports EPA mobile source emission inventory development. This article discusses the real-world emissions of light-duty vehicles with 12V Start-Stop technology and light-duty vehicles using both gasoline and diesel fuels.

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Kobayashi, Tomohiro, Ayumu Sato, Kazuyuki Hosaka, Seishi Sekine, and Masashi Okawa. "Measurement of Spectral Radiant Exitance Tungsten Cluster Light Emission." JOURNAL OF THE ILLUMINATING ENGINEERING INSTITUTE OF JAPAN 86, Appendix (2002): 257. http://dx.doi.org/10.2150/jieij1980.86.appendix_257.

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Zhai, Bao Gai, and Yuan Ming Huang. "Blue Light Emission from a Rod-Like Liquid Crystal." Key Engineering Materials 428-429 (January 2010): 288–91. http://dx.doi.org/10.4028/www.scientific.net/kem.428-429.288.

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A rod-like liquid crystal 4-butoxybenzylidene-4'-octylphenylamine was synthesized. The molecular structure and the liquid crystalline phases of the synthesized compound were characterized with the nuclear magnetic resonance spectroscopy, the differential scanning calorimetry, and the polarizing optical microscopy, respectively. The absorption measurement shows that the dilute tetrahydrofuran solutions of the rod-like liquid crystal absorb photons at about 290 and 330 nm, respectively; while the luminescence measurements indicate that this rod-like liquid crystal can give off intense blue photoluminescence with its dominant peak located at about 430 nm. Using Hückel tight-binding program, we have calculated the electronic structures of the liquid crystal, and the origin of the blue photoluminescence is discussed. Introduction

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Sugimoto, Tatsunori, Toshiya Noro, Satarou Yamaguchi, Hideyoshi Majima, and Tomohisa Kato. "Spectroscopic Measurement of Electric Discharge Machining for Silicon Carbide." Materials Science Forum 615-617 (March 2009): 609–12. http://dx.doi.org/10.4028/www.scientific.net/msf.615-617.609.

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Diamond saw is generally used to make the silicon carbide (SiC) wafers from ingots, but it takes long time for cutting. We have used the electric discharge machining (EDM) to cut SiC. The cutting speed of EDM for SiC is almost 10 times faster than the diamond saw, and the surface roughness is 1/10 for the diamond saw. EDM cut SiC by the plasma produced between the wire and SiC material. The emissions from EDM plasma may involve much information for EDM cutting. We monitored the total light intensity by a photodiode, and observed the spectrum of the emission from EDM plasma by a visible spectroscopy. The discharge gas used helium and argon. In both discharges, the light emission was observed when the current was not zero. Also, many lines were observed Si I, Si II and C I from the SiC sample, and Cu I and Zn I from the wire. And, the electron temperature of EDM plasma was estimated to be under several eV because the observed lines were almost the emission from atoms. Also, the scars, which show the copper-alloy wire was hurt by discharge, were observed from the wire.

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Mei, Hui, Lulu Wang, Menglei Wang, Rencheng Zhu, Yunjing Wang, Yi Li, Ruiqin Zhang, Bowen Wang, and Xiaofeng Bao. "Characterization of Exhaust CO, HC and NOx Emissions from Light-Duty Vehicles under Real Driving Conditions." Atmosphere 12, no. 9 (August 31, 2021): 1125. http://dx.doi.org/10.3390/atmos12091125.

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On-road exhaust emissions from light-duty vehicles are greatly influenced by driving conditions. In this study, two light-duty passenger cars (LDPCs) and three light-duty diesel trucks (LDDTs) were tested to investigate the on-road emission factors (EFs) with a portable emission measurement system. Emission characteristics of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) emitted from vehicles at different speeds, accelerations and vehicle specific power (VSP) were analyzed. The results demonstrated that road conditions have significant impacts on regulated gaseous emissions. CO, NOx, and HC emissions from light-duty vehicles on urban roads increased by 1.1–1.5, 1.2–1.4, and 1.9–2.6 times compared with those on suburban and highway roads, respectively. There was a rough positive relationship between transient CO, NOx, and HC emission rates and vehicle speeds, while the EFs decreased significantly with the speed decrease when speed ≤ 20 km/h. The emissions rates of NOx and HC tended to increase and then decrease as the acceleration increased and the peak occurred at 0 m/s2 without considering idling conditions. For HC and CO, the emission rates were low and changed gently with VSP when VSP < 0, while emission rates increased gradually with the VSP increase when VSP > 0. For NOx NOx emission rates were lower and had no obvious change when VSP < 0. However, NOx emissions were positively correlated with VSP, when VSP > 0.

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FORBUS, W. R., G. G. DULL, and D. A. SMITTLE. "NONDESTRUCTIVE MEASUREMENT OF CANARY MELON MATURITY BY DELAYED LIGHT EMISSION." Journal of Food Quality 15, no. 2 (May 1992): 119–27. http://dx.doi.org/10.1111/j.1745-4557.1992.tb00980.x.

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OHSUGA, Minoru, Hirosi KUROIWA, Yoshishige OHYAMA, and Takashi SAITO. "Measurement of Spark Light Emission Using an Optical Combustion Sensor." Transactions of the Japan Society of Mechanical Engineers Series C 58, no. 551 (1992): 2125–30. http://dx.doi.org/10.1299/kikaic.58.2125.

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Helzhynsky, Ihor, Stepan Kutsiy, Andriy Veryha, Khrystyna Ivaniuk, and Taras Dudok. "Development of portable device for measurement of dynamic and static light-emission WOLED characteristics." Technology audit and production reserves 1, no. 1(57) (February 26, 2021): 30–33. http://dx.doi.org/10.15587/2706-5448.2021.225239.

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The research object of this work is the parameters of organic light-emitting diodes, namely power and luminous flux. Determination of these parameters can be carried out using a photodiode and requires measuring the dark current of the sensor (photodiode), measuring the current of the photodiode when illuminated by the LED under investigation. And also take into account the relationship between the light flux received by the sensor and its output current, and take into account the spectral characteristics of the sensor. Calculate the investigated parameters of the LED based on the measurements. Carrying out these measurements requires laboratory instruments and workplace organization, and further calculations are routine work. It is possible to increase the measurement accuracy by improving the existing methods for measuring the required parameters, and it is possible to automate the process of measurements and calculations using a modern microprocessor radioelement base. Microcontrollers are widespread such radioelements. They have the necessary peripherals for independent operation and have sufficient computing power to implement the required measuring device. Its application makes it possible to automate the measurement process, carry out the necessary calculations, save correction constants, accumulate and process the obtained data, analyze these received data, exchange data with a computer, etc. So, the work is aimed at developing a methodology that will allow the simultaneous measurement of power and luminous flux of planar light sources. And also on the feasibility of this technique in the device and software with the ability to measure the power of the light source in an arbitrary band of the spectral visible range. Thus, it is possible to determine what power in watts a light source emits with the dynamics of supply currents in the optical bands, knowing the spectrum of this source without using glass filters. So, the result of applying the technique is to determine the power of light radiation (in watts) or the luminous flux (in lumens) of the emitter (light sources).

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Matsumoto, Toshio. "Infrared Extragalactic Background Light." Symposium - International Astronomical Union 139 (1990): 317–26. http://dx.doi.org/10.1017/s0074180900240874.

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Infrared extragalactic background light plays an important role in the study of the early history of the universe, especially as a probe to search for the primeval galaxies. In the near-infrared region, UV and visible light emitted from high redshift galaxies could be observable. Measurement of the sky fluctuation at 2.2 μm gives a very low upper limit. The rocket observation of the near-infrared diffuse emission reveals isotropic emission which is possibly ascribed to an extragalactic origin. The observed brightness and fluctuation are not consistent with the standard scenario of the primeval galaxies. In the far-infrared region, integrated light of dust emission of the distant galaxies forms another cosmic background radiation. IRAS and the Nagoya-Berkeley rocket experiment found a clear correlation between HI column density and far-infrared sky brightness; however, there remains an uncorrelated isotropic emission component. If we ascribe this emission to extragalactic origin, a fairly big evolution effect is required. In the submillimeter region, excess emission over the 2.74K blackbody spectrum was found, which requires the vast energy generation in the early universe.

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Zhao, Yan Jun, Cheng Bin Gao, and Bin Qu. "Soot Concentration Interference Measurement System Caused by Multidispersion Soot Different Position." Applied Mechanics and Materials 540 (April 2014): 277–80. http://dx.doi.org/10.4028/www.scientific.net/amm.540.277.

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One of the pollutant emission parameters is soot emission concentration. The light intensity scattering method is commonly used in monitoring the soot emission concentration. The distance between the sensor and the soot is different; the sensor acceptance scattering light angle range of the different position multidispersion soot is different and the ratio of the soot scattering light intensity and the total light intensity is different. So it can decreases soot emission concentration accuracy. To improve soot concentration accuracy, soot concentration interference caused by the multidispersion soot different position is studied in this paper. Numerical simulation results show that the different parameters multidispersion soot position can increase soot concentration error. Solution method on the multidispersion soot different position is brought out. The interference measurement system caused by the different multidispersion soot position is designed and the experimental results show that the measurement system can on-time measure the soot position interference and decrease the soot concentration measurement error.

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Si, Zhao, Tongbo Wei, Jun Ma, Ning Zhang, Zhe Liu, Xuecheng Wei, Xiaodong Wang, Hongxi Lu, Junxi Wang, and Jinmin Li. "Improved Yellow Light Emission in the Achievement of Dichromatic White Light Emitting Diodes." MRS Proceedings 1538 (2013): 371–75. http://dx.doi.org/10.1557/opl.2013.549.

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ABSTRACTA study about the achievement of dichromatic white light-emitting diodes (LEDs) was performed. A series of dual wavelength LEDs with different last quantum-well (LQW) structure were fabricated. The bottom seven blue light QWs (close to n-GaN layer) of the four samples were the same. The LQW of sample A was 3 nm, and that of sample B, C and D were 6 nm, a special high In content ultra-thin layer was inserted in the middle of the LQW of sample C and on top of that of sample D. XRD results showed In concentration fluctuation and good interface quality of the four samples. PL measurements showed dual wavelength emitting, the blue light peak position of the four samples were almost the same, sample A with a narrower LQW showed an emission wavelength much shorter than that of sample B, C, D. EL measurement was done at an injection current of 100 mA. Sample A only showed LQW emission due to holes distribution. Because of wider LQW, the emission wavelength of sample B, C and D was longer and peak intensity was weaker. Sample D with insert layer on top of LQW showed strongest yellow light emission with a blue peak. As the injection current increased, sample A showed highest output light power due to narrower LQW. Of the other three samples with wider LQW, sample D showed highest output power. Effective yellow light emission has always been an obstacle to the achievement of dichromatic white LED. Sample D with insert layer close to p-GaN can confine the hole distribution more effectively hence the recombination of holes and electrons was enhanced, the yellow light emission was improved and dichromatic white LED was achieved.

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Wang, J. M., C. H. Jeong, N. Zimmerman, R. M. Healy, D. K. Wang, F. Ke, and G. J. Evans. "Plume-based analysis of vehicle fleet air pollutant emissions and the contribution from high emitters." Atmospheric Measurement Techniques 8, no. 8 (August 13, 2015): 3263–75. http://dx.doi.org/10.5194/amt-8-3263-2015.

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Abstract. An automated identification and integration method has been developed for in-use vehicle emissions under real-world conditions. This technique was applied to high-time-resolution air pollutant measurements of in-use vehicle emissions performed under real-world conditions at a near-road monitoring station in Toronto, Canada, during four seasons, through month-long campaigns in 2013–2014. Based on carbon dioxide measurements, over 100 000 vehicle-related plumes were automatically identified and fuel-based emission factors for nitrogen oxides; carbon monoxide; particle number; black carbon; benzene, toluene, ethylbenzene, and xylenes (BTEX); and methanol were determined for each plume. Thus the automated identification enabled the measurement of an unprecedented number of plumes and pollutants over an extended duration. Emission factors for volatile organic compounds were also measured roadside for the first time using a proton transfer reaction time-of-flight mass spectrometer; this instrument provided the time resolution required for the plume capture technique. Mean emission factors were characteristic of the light-duty gasoline-dominated vehicle fleet present at the measurement site, with mean black carbon and particle number emission factors of 35 mg kg fuel−1 and 7.5 × 1014 # kg fuel−1, respectively. The use of the plume-by-plume analysis enabled isolation of vehicle emissions, and the elucidation of co-emitted pollutants from similar vehicle types, variability of emissions across the fleet, and the relative contribution from heavy emitters. It was found that a small proportion of the fleet (< 25 %) contributed significantly to total fleet emissions: 100, 100, 81, and 77 % for black carbon, carbon monoxide, BTEX, and particle number, respectively. Emission factors of a single pollutant may help classify a vehicle as a high emitter; however, regulatory strategies to more efficiently target multi-pollutant mixtures may be better developed by considering the co-emitted pollutants as well.

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Wang, J. M., C. H. Jeong, N. Zimmerman, R. M. Healy, D. K. Wang, F. Ke, and G. J. Evans. "Plume-based analysis of vehicle fleet air pollutant emissions and the contribution from high emitters." Atmospheric Measurement Techniques Discussions 8, no. 3 (March 18, 2015): 2881–912. http://dx.doi.org/10.5194/amtd-8-2881-2015.

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Abstract. An automated identification and integration method has been developed to investigate in-use vehicle emissions under real-world conditions. This technique was applied to high time resolution air pollutant measurements of in-use vehicle emissions performed under real-world conditions at a near-road monitoring station in Toronto, Canada during four seasons, through month-long campaigns in 2013–2014. Based on carbon dioxide measurements, over 100 000 vehicle-related plumes were automatically identified and fuel-based emission factors for nitrogen oxides; carbon monoxide; particle number, black carbon; benzene, toluene, ethylbenzene, and xylenes (BTEX); and methanol were determined for each plume. Thus the automated identification enabled the measurement of an unprecedented number of plumes and pollutants over an extended duration. Emission factors for volatile organic compounds were also measured roadside for the first time using a proton transfer reaction time-of-flight mass spectrometer; this instrument provided the time resolution required for the plume capture technique. Mean emission factors were characteristic of the light-duty gasoline dominated vehicle fleet present at the measurement site, with mean black carbon and particle number emission factors of 35 mg kg−1 and 7.7 × 1014 kg−1, respectively. The use of the plume-by-plume analysis enabled isolation of vehicle emissions, and the elucidation of co-emitted pollutants from similar vehicle types, variability of emissions across the fleet, and the relative contribution from heavy emitters. It was found that a small proportion of the fleet (< 25%) contributed significantly to total fleet emissions; 95, 93, 76, and 75% for black carbon, carbon monoxide, BTEX, and particle number, respectively. Emission factors of a single pollutant may help classify a vehicle as a high emitter. However, regulatory strategies to more efficiently target multi-pollutants mixtures may be better developed by considering the co-emitted pollutants as well.

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Tang, Jiao, Jiaqi Wang, Guangcai Zhong, Hongxing Jiang, Yangzhi Mo, Bolong Zhang, Xiaofei Geng, et al. "Measurement report: Long-emission-wavelength chromophores dominate the light absorption of brown carbon in aerosols over Bangkok: impact from biomass burning." Atmospheric Chemistry and Physics 21, no. 14 (July 28, 2021): 11337–52. http://dx.doi.org/10.5194/acp-21-11337-2021.

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Abstract. Chromophores represent an important portion of light-absorbing species, i.e., brown carbon. Yet knowledge of what and how chromophores contribute to aerosol light absorption is still sparse. To address this problem, we examined soluble independent chromophores in a set of year-round aerosol samples from Bangkok. The water-soluble fluorescent chromophores identified via excitation–emission matrix (EEM) spectroscopy and follow-up parallel factor analysis could be mainly assigned as humic-like substances and protein-like substances, which differed in their EEM pattern from that of the methanol-soluble fraction. The emission wavelength of fluorescent chromophores in environmental samples tended to increase compared with that of the primary combustion emission, which could be attributed to secondary formation or the aging process. Fluorescent indices inferred that these light-absorbing chromophores were not significantly humified and comprised a mixture of organic matter of terrestrial and microbial origin, which exhibited a different characteristic from primary biomass burning and coal-combustion results. A multiple linear regression analysis revealed that larger fluorescent chromophores that were oxygen-rich and highly aromatic with high molecular weights were the key contributors of light absorption, preferably at longer emission wavelengths (λmax⁡ > 500 nm). Positive matrix factorization analysis further suggested that up to 50 % of these responsible chromophores originated from biomass burning emissions.

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Qiao, Fengxiang, Mahreen Nabi, Qing Li, and Lei Yu. "Estimating Light-Duty Vehicle Emission Factors using Random Forest Regression Model with Pavement Roughness." Transportation Research Record: Journal of the Transportation Research Board 2674, no. 8 (June 19, 2020): 37–52. http://dx.doi.org/10.1177/0361198120922997.

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Pavement roughness would affect the running of vehicle movement, and thus possibly impact fuel consumption and vehicle emissions, the numerical relationships and analytical steps of which are, however, not yet well studied. The major objective of this paper is to quantify vehicular emission factors—hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOx), and carbon dioxide (CO2)—and fuel consumption as a function of pavement roughness (the International Roughness Index [IRI]) and other factors. Within each operating mode identification (OMID) bins of vehicle operational status, a random forest regression model (RFRM) was identified to estimate emission factors and fuel consumption. The field test data, with a total length of 1,067.41 mi driving and 323,075 data pairs from one test vehicle, were used to train and validate models. The portable emissions measurement system (PEMS) and a smartphone application for IRI were employed for the tests in Texas, U.S., roadways. Results show that the optimum roughness conditions for lower emissions and fuel consumption are in categories B and C with moderate roughness. The root-mean-square error (RMSE) during training, testing, and validation processes of the RFRM are within 6.4%, implying a good fit of resulted models. IRI has the most OMID bins as number one predictor, followed by vehicle specific power (VSP) and speed. Through separated modeling for each OMID, the impacts of IRI are successfully grasped. It is recommended conducting more field measurements with more vehicle types. This would help with possible incorporation of vehicle emissions, fuel consumption, and other environmental factors into the pavement design, maintenance, and retrofitting process.

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Taipale, R., M. K. Kajos, J. Patokoski, P. Rantala, T. M. Ruuskanen, and J. Rinne. "Role of de novo biosynthesis in ecosystem scale monoterpene emissions from a boreal Scots pine forest." Biogeosciences 8, no. 8 (August 18, 2011): 2247–55. http://dx.doi.org/10.5194/bg-8-2247-2011.

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Abstract. Monoterpene emissions from Scots pine have traditionally been assumed to originate as evaporation from specialized storage pools. More recently, the significance of de novo emissions, originating directly from monoterpene biosynthesis, has been recognized. To study the role of biosynthesis at the ecosystem scale, we measured monoterpene emissions from a Scots pine dominated forest in southern Finland using the disjunct eddy covariance method combined with proton transfer reaction mass spectrometry. The interpretation of the measurements was based on a correlation analysis and a hybrid emission algorithm describing both de novo and pool emissions. During the measurement period May–August 2007, the monthly medians of daytime emissions were 200, 290, 180, and 200 μg m−2 h−1. The emissions were partly light dependent, probably due to de novo biosynthesis. The emission potential for both de novo and pool emissions exhibited a decreasing summertime trend. The ratio of the de novo emission potential to the total emission potential varied between 30 % and 46 %. Although the monthly changes were not significant, the ratio always differed statistically from zero, suggesting that the role of de novo biosynthesis was observable. Given the uncertainties in this study, we conclude that more accurate estimates of the contribution of de novo emissions are required for improving monoterpene emission algorithms for Scots pine dominated forests.

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Ro, Seungcheon, Junhong Park, Myunghwan Shin, and Jongtae Lee. "Developing On-Road NOx Emission Factors for Euro 6b Light-Duty Diesel Trucks in Korean Driving Conditions." Energies 14, no. 4 (February 16, 2021): 1041. http://dx.doi.org/10.3390/en14041041.

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This study aimed to develop on-road NOx emission factors for Euro 6b light-duty diesel trucks (LDDTs) in Korea. On-road NOx emissions were measured using portable emissions measurement systems and compared with those measured using the Korean Driving Cycle (KDC), the conventional laboratory test used to develop emission factors. To ensure the representativeness of the LDDTs emission factors, five vehicles of three models were driven along two real driving routes for total traveled mileage of 2280 km. On-road NOx levels were 2.1 to 6.9 times higher on average than those measured using the KDC because the latter does not cover the wide variability in vehicle speed and relative positive acceleration, common in real driving conditions. The lean-NOx trap was found to have disappointingly low NOx reduction efficiency in on-road driving. The on-road NOx emission factors by vehicle speeds developed in this study were comparable to the COPERT 4 factors.

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Abis, Letizia, Carmen Kalalian, Bastien Lunardelli, Tao Wang, Liwu Zhang, Jianmin Chen, Sébastien Perrier, Benjamin Loubet, Raluca Ciuraru, and Christian George. "Measurement report: Biogenic volatile organic compound emission profiles of rapeseed leaf litter and its secondary organic aerosol formation potential." Atmospheric Chemistry and Physics 21, no. 16 (August 24, 2021): 12613–29. http://dx.doi.org/10.5194/acp-21-12613-2021.

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Abstract. We analysed the biogenic volatile organic compound (BVOC) emissions from rapeseed leaf litter and their potential to create secondary organic aerosols (SOAs) under three different conditions, i.e., (i) in the presence of UV light irradiation, (ii) in the presence of ozone, and (iii) with both ozone and UV light. These experiments were performed in a controlled atmospheric simulation chamber containing leaf litter samples, where BVOC and aerosol number concentrations were measured for 6 d. Our results show that BVOC emission profiles were affected by UV light irradiation which increased the summed BVOC emissions compared to the experiment with solely O3. Furthermore, the diversity of emitted VOCs from the rapeseed litter also increased in the presence of UV light irradiation. SOA formation was observed when leaf litter was exposed to both UV light and O3, indicating a potential contribution to particle formation or growth at local scales. To our knowledge, this study investigates, for the first time, the effect of UV irradiation and O3 exposure on both VOC emissions and SOA formation for leaf litter samples. A detailed discussion about the processes behind the biological production of the most important VOC is proposed.

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Konovalov, I. B., and M. Beekmann. "On the Use of Air Quality Monitoring Networks for the Evaluation of Nitrogen Oxide Emission Inventories." Open Atmospheric Science Journal 2, no. 1 (November 19, 2008): 232–48. http://dx.doi.org/10.2174/1874282300802010232.

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The usefulness of ground based air quality monitoring data for diagnostics of uncertainties in gridded emission inventories is examined. A general probabilistic procedure for comparison of levels of uncertainties in different emission datasets is developed. It implies the evaluation of the agreement between modeling results obtained with these emission datasets and corresponding measurements. This procedure is applied to the evaluation of different datasets for European gridded nitrogen oxide (NOx) emissions by using the AirBase monitoring data and the CHIMERE chemistry-transport model. Numerical experiments are performed for two different types of spatial distributions of emission uncertainties and five different types of monitors. The results are also generalized for various levels of uncertainties in simulated and measured data. It is found, in particular, that most informative, from the point of view of diagnostics of NOx emission uncertainties, are the measurements of NO2 at rural background sites and measurements of ozone at suburban sites situated in the vicinity of intensive sources of emissions. A more precise conclusion regarding the relative accuracy of two emission datasets can be drawn with a larger number of monitors in a network and a higher accuracy of the model and measurements. For example, with a network of 50 rural background NO2 monitors, the probability of choosing the more certain emission data set is more than 90 percent, if differences in uncertainty of two sets are more than 50 percent. Practical recommendations for designing or evolving surface measurement networks, in light of the study results, are given.

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Mohanta, S. K., R. K. Soni, S. Tripathy, and Soo Jin Chua. "Visible Light Emission from Ordered Nanopatterned InP Surface." Advanced Materials Research 31 (November 2007): 56–58. http://dx.doi.org/10.4028/www.scientific.net/amr.31.56.

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The InP nanostructures have been fabricated by low-energy Ar+-ion of dose 1 × 1018 cm-2 and energy 50 keV, at normal incidence. The InP nanodot size varies from 50 to 90 nm. Photoluminescence spectra show blue shifted visible emission band at 1.98 eV, and quenching of the band edge emission from the nanopatterned surface. The blue-shifted emission band arises due to size convoluted band-to-band emission form the surface nanodots while the defects formation in the irradiated surface leads to the quenching of band edge emission. Thermal annealing results in clustering of the patterned surface and enhancement of the band edge emission accompanied with absence of visible band. Our results show that the origin of visible emission is from the surface nanodots and not from the nanocrystallites in the implanted surface region. This is corroborated by the wavelength dependence of photoluminescence measurement by probing different depth of the disordered region.

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Zhao, Yan Jun, Cheng Bin Gao, and Bin Qu. "Research on Environment Materials with Soot Position Influence on SO₂ Concentration Measurement." Applied Mechanics and Materials 540 (April 2014): 251–54. http://dx.doi.org/10.4028/www.scientific.net/amm.540.251.

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The pollutant gaseous SO2 concentration is one of the most important parameters in national atmosphere environment monitoring system with properties of environment materials. SO2 emission can be calculated through measuring SO2 concentration. The common SO2 concentration measurement method of the stationary pollutant sources is NDIR. Soot in duct can absorb the measurement light intensity and the different acceptance light intensity of the receiver is caused by soot different position, so the attenuation of SO2 measurement light intensity is increased and the SO2 emission concentration measurement data is error. The different soot position interference is studied in this paper. Simulation results show that soot difference position can interference SO2 concentration measurement accuracy. The experiment is carried on. The experiment result shows that the measurement method can on-time obtains the soot different position interference and decreases SO2 concentration measurement error.

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31

Valverde, Victor, Bernat Mora, Michaël Clairotte, Jelica Pavlovic, Ricardo Suarez-Bertoa, Barouch Giechaskiel, Covadonga Astorga-LLorens, and Georgios Fontaras. "Emission Factors Derived from 13 Euro 6b Light-Duty Vehicles Based on Laboratory and On-Road Measurements." Atmosphere 10, no. 5 (May 2, 2019): 243. http://dx.doi.org/10.3390/atmos10050243.

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Tailpipe emissions of a pool of 13 Euro 6b light-duty vehicles (eight diesel and five gasoline-powered) were measured over an extensive experimental campaign that included laboratory (chassis dynamometer), and on-road tests (using a portable emissions measurement system). The New European Driving Cycle (NEDC) and the Worldwide harmonised Light-duty vehicles Test Cycle (WLTC) were driven in the laboratory following standard and extended testing procedures (such as low temperatures, use of auxiliaries, modified speed trace). On-road tests were conducted in real traffic conditions, within and outside the boundary conditions of the regulated European Real-Driving Emissions (RDE) test. Nitrogen oxides (NOX), particle number (PN), carbon monoxide (CO), total hydrocarbons (HC), and carbon dioxide (CO2) emission factors were developed considering the whole cycles, their sub-cycles, and the first 300 s of each test to assess the cold start effect. Despite complying with the NEDC type approval NOX limit, diesel vehicles emitted, on average, over the WLTC and the RDE 2.1 and 6.7 times more than the standard limit, respectively. Diesel vehicles equipped with only a Lean NOX trap (LNT) averaged six and two times more emissions over the WLTC and the RDE, respectively, than diesel vehicles equipped with a selective catalytic reduction (SCR) catalyst. Gasoline vehicles with direct injection (GDI) emitted eight times more NOX than those with port fuel injection (PFI) on RDE tests. Large NOX emissions on the urban section were also recorded for GDIs (122 mg/km). Diesel particle filters were mounted on all diesel vehicles, resulting in low particle number emission (~1010 #/km) over all testing conditions including low temperature and high dynamicity. GDIs (~1012 #/km) and PFIs (~1011 #/km) had PN emissions that were, on average, two and one order of magnitude higher than for diesel vehicles, respectively, with significant contribution from the cold start. PFIs yielded high CO emission factors under high load operation reaching on average 2.2 g/km and 3.8 g/km on WLTC extra-high and RDE motorway, respectively. The average on-road CO2 emissions were ~33% and 41% higher than the declared CO2 emissions at type-approval for diesel and gasoline vehicles, respectively. The use of auxiliaries (AC and lights on) over the NEDC led to an increase of ~20% of CO2 emissions for both diesel and gasoline vehicles. Results for NOX, CO and CO2 were used to derive average on-road emission factors that are in good agreement with the emission factors proposed by the EMEP/EEA guidebook.

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Haapanala, S., J. Rinne, H. Hakola, H. Hellén, L. Laakso, H. Lihavainen, R. Janson, C. O'Dowd, and M. Kulmala. "Boundary layer concentrations and landscape scale emissions of volatile organic compounds in early spring." Atmospheric Chemistry and Physics 7, no. 7 (April 16, 2007): 1869–78. http://dx.doi.org/10.5194/acp-7-1869-2007.

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Abstract. Boundary layer concentrations of several volatile organic compounds (VOC) were measured during two campaigns in springs of 2003 and 2006. The measurements were conducted over boreal landscapes near SMEAR II measurement station in Hyytiälä, Southern Finland. In 2003 the measuremens were performed using a light aircraft and in 2006 using a hot air balloon. Isoprene concentrations were low, usually below detection limit. This can be explained by low biogenic production due to cold weather, phenological stage of the isoprene emitting plants, and snow cover. Monoterpenes were observed frequently. The average total monoterpene concentration in the boundary layer was 33 pptv. Many anthropogenic compounds such as benzene, xylene and toluene, were observed in high amounts. Ecosystem scale surface emissions were estimated using a simple mixed box budget methodology. Total monoterpene emissions varied up to 80 μg m−2 h−1, α-pinene contributing typically more than two thirds of that. These emissions were somewhat higher that those calculated using emission algorithm. The highest emissions of anthropogenic compounds were those of p/m xylene.

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Ibrahim, O., R. Shaiganfar, R. Sinreich, T. Stein, U. Platt, and T. Wagner. "Auto MAX-DOAS measurements around entire cities: quantification of NOx emissions from the cities of Mannheim and Ludwigshafen (Germany)." Atmospheric Measurement Techniques Discussions 3, no. 1 (February 11, 2010): 469–99. http://dx.doi.org/10.5194/amtd-3-469-2010.

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Abstract. We present Auto Multi-Axis (MAX-) DOAS observations of tropospheric NO2 carried out on circles around the cities of Mannheim and Ludwigshafen (Germany) on 24 August 2006. Together with information on wind speed and direction, the total emissions of the encircled source(s) can be quantified from these measurements. In contrast to recent similar studies based on of zenith scattered sun light (elevation angle of 90°), we use a MAX-DOAS instrument mounted on a car, which observes scattered sun light under different elevation angles (here 45°, and 90°). Compared to simple zenith sky observations, MAX-DOAS observations have higher sensitivity and avoid systematic offsets in the determination of the vertically integrated trace gas concentration. Auto MAX-DOAS observations are especially well suited for the determination of the total emission of extended emission sources (e.g. whole cities), for which typically no sharply defined plumes are formed. In such cases, the trace gas concentrations can be rather small and thus even small systematic offsets in the observed integrated tropospheric trace gas concentration can have a large effect on the determined total emissions. However, such measurements are still affected by several uncertainties which need to be further investigated and minimised. The largest error source is probably the variability and imperfect knowledge of the wind field. In addition – depending on the trace species observed – also chemical transformations between the emission sources and the measurement location have to be considered. In this study we use local observations within the encircled area to quantify and correct these errors. From our observations we derive a total NOx emission from the Mannheim/Ludwigshafen area of (7.2±1.7)×1024 molecules/s (or 17350±4100 t, calculated with the mass of NO2), which is in surprisingly good agreement with existing emission estimates.

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34

Kamata, Isaho, Xuan Zhang, and Hidekazu Tsuchida. "Photoluminescence Imaging and Wavelength Analysis of Basal Plane Frank-Type Defects in 4H-SiC Epilayers." Materials Science Forum 725 (July 2012): 15–18. http://dx.doi.org/10.4028/www.scientific.net/msf.725.15.

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Frank-type defects on a basal plane have been investigated using photoluminescence (PL) imaging microscopy and wavelength profile measurement. A wide range of emission in the near-infrared wavelength was observed from a Frank partial dislocation at the edge of the defect, while a narrow emission at around the visible light range was obtained from a stacking fault region. The emissions from a stacking fault region of three kinds of basal plane Frank-type defects were confirmed to have different wavelengths depending on their stacking structures.

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35

SOMEYA, Satoshi, Kaoru TOMINAGA, Hirohide FURUTANI, and Koji OKAMOTO. "Instantaneous Surface Temperature Measurement Applicable in a Severe Condition with Light Emission." Transaction of the Visualization Society of Japan 32, no. 10 (2012): 29–36. http://dx.doi.org/10.3154/tvsj.32.29.

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36

Boughedaoui, Ménouèr, Robert Joumard, and Rabah Kerbachi. "On-Board Emission Measurement of High-Loaded Light-Duty Vehicles in Algeria." Journal of the Air & Waste Management Association 58, no. 1 (January 2008): 45–54. http://dx.doi.org/10.3155/1047-3289.58.1.45.

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Zhan, Jin, Zhang Jie, Liu Yun-Quan, Li Kun, Yuan Xiao-Hui, Hao Zuo-Qiang, Zheng Jun, et al. "Coherence Measurement of White Light Emission from Femtosecond Laser Propagation in Air." Chinese Physics Letters 22, no. 10 (September 22, 2005): 2608–10. http://dx.doi.org/10.1088/0256-307x/22/10/042.

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38

Ho, Dzung Minh, and Thang Xuan Dinh. "ESTIMATION OF AIR POLLUTANTS EMISSION FACTORS FOR VEHICLES ON ROAD TRAFFIC SUITABLE WITH HOCHIMINH CITY CONDITION." Science and Technology Development Journal 13, no. 3 (September 30, 2010): 5–18. http://dx.doi.org/10.32508/stdj.v13i3.2138.

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The estimation of emissions depends strongly on the quality of the emission factors used for the calculations. It is necessary to find method for estimation of emission factors from road traffic to calculate the emissions of air pollutants from transportation activity in Hochiminh City (HCMC). From the research results, suitable method and tracer were selected. Emission factors of 15 VOCs from C2-C6, NOx, and CO from road traffic in HCMC were estimated. The measurement campaign was carried out in 3/2 street., distrist 10, HCMC from 10h00 to 22h00 per day. Three VOCs compounds with high average emission factors were hexane (59,7  9,2 mg/km.veh.), i-pentane (52,7  7,4 mg/km.veh.) and 3-methylpentane (36,1  3,6 mg/km.veh.). The average emission factor of NOx and CO were 0,20  0,03 g/km.veh and 23,37  6,61 g/km.veh, respectively. Besides, the emission factors of air pollutants for motorcycles, light duty vehicles and heavy duty vehicles were caculated by regression linear method.

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39

Wiesner, Anne, Sascha Pfeifer, Maik Merkel, Thomas Tuch, Kay Weinhold, and Alfred Wiedensohler. "Real World Vehicle Emission Factors for Black Carbon Derived from Longterm In-Situ Measurements and Inverse Modelling." Atmosphere 12, no. 1 (December 29, 2020): 31. http://dx.doi.org/10.3390/atmos12010031.

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Black carbon (BC) is one of the most harmful substances within traffic emissions, contributing considerably to urban pollution. Nevertheless, it is not explicitly regulated and the official laboratory derived emission factors are barely consistent with real world emissions. However, realistic emission factors (EFs) are crucial for emission, exposure, and climate modelling. A unique dataset of 10 years (2009–2018) of roadside and background measurements of equivalent black carbon (eBC) concentration made it possible to estimate real world traffic EFs and observe their change over time. The pollutant dispersion was modelled using the Operational Street Pollution Model (OSPM). The EFs for eBC are derived for this specific measurement site in a narrow but densely trafficked street canyon in Leipzig, Germany. The local conditions and fleet composition can be considered as typical for an inner-city traffic scenario in a Western European city. The fleet is composed of 22% diesel and 77% petrol cars in the passenger car segment, with an unknown proportion of direct injection engines. For the mixed fleet the eBC EF was found to be 48 mg km−1 in the long-term average. Accelerated by the introduction of a low emission zone, the EFs decreased over the available time period from around 70 mg km−1 to 30–40 mg km−1. Segregation into light (<3.5 t) and heavy (>3.5 t) vehicles resulted in slightly lower estimates for the light vehicles than for the mixed fleet, and one order of magnitude higher values for the heavy vehicles. The found values are considerably higher than comparable emission standards for particulate matter and even the calculations of the Handbook Emission Factors for Road Transport (HBEFA), which is often used as emission model input.

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40

Фролов, И. В., В. А. Сергеев, and О. А. Радаев. "Измерение внутреннего квантового выхода излучения InGaN светодиода." Журнал технической физики 91, no. 8 (2021): 1264. http://dx.doi.org/10.21883/jtf.2021.08.51102.54-21.

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A method for measuring of internal quantum efficiency of InGaN-based light-emitting diode is presented. The method consists in measuring the emission power and 3dB frequencies of the LED electroluminescence at two low currents corresponding to the range of growth of the quantum efficiency of the LED, and calculating the value of the internal quantum efficiency according to the corresponding functional dependence. To determine the internal quantum efficiency at other current values, the current dependence of the external quantum efficiency is measured and the coefficient of emission extraction from the structure is calculated from the results of measurements of the internal and external quantum efficiency at a low current. The reliability of the measurement method is confirmed by comparing the measurement results with the results obtained by a known measurement method. The relative difference in measurement results is within 3%.

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Bon, D. M., J. A. de Gouw, C. Warneke, W. C. Kuster, M. L. Alexander, A. Baker, A. Beyersdorf, et al. "Measurements of volatile organic compounds at a suburban ground site (T1) in Mexico City during the MILAGRO 2006 campaign: measurement comparison, emission ratios, and source attribution." Atmospheric Chemistry and Physics Discussions 10, no. 10 (October 8, 2010): 23229–86. http://dx.doi.org/10.5194/acpd-10-23229-2010.

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Abstract. Volatile organic compound (VOC) mixing ratios were measured with two different instruments at the T1 ground site in Mexico City during the Megacity Initiative: Local and Global Research Observations (MILAGRO) campaign in March of 2006. A gas chromatograph with flame ionization detector (GC-FID) quantified 18 light alkanes, alkenes and acetylene while a proton-transfer-reaction ion-trap mass spectrometer (PIT-MS) quantified 12 VOC species including oxygenated VOCs (OVOCs) and aromatics. A GC separation system was used in conjunction with the PIT-MS (GC-PIT-MS) to evaluate PIT-MS measurements and to aid in the identification of unknown VOCs. The VOC measurements are also compared to simultaneous canister samples and to two independent proton-transfer-reaction mass spectrometers (PTR-MS) deployed on a mobile and an airborne platform during MILAGRO. VOC diurnal cycles demonstrate the large influence of vehicle traffic and liquid propane gas (LPG) emissions during the night and photochemical processing during the afternoon. Emission ratios for VOCs and OVOCs are determined from early-morning enhancement ratios and compared to emission ratios calculated from the PMF results. Average emission ratios for non-oxygenated species relative to CO are on average a factor of 2 higher than measured for US cities. Emission ratios for OVOCs are estimated and compared to literature values the northeastern US and to tunnel studies in California. Positive matrix factorization analysis (PMF) is used to provide insight into VOC sources and processing and to estimate OVOC emission ratios. Three PMF factors were distinguished by the analysis including the emissions from vehicles, the use of liquid propane gas and the production of secondary VOCs + long-lived species. The total PIT-MS signal was summed to estimate the fraction of identified vs. unidentified VOC species.

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Bon, D. M., I. M. Ulbrich, J. A. de Gouw, C. Warneke, W. C. Kuster, M. L. Alexander, A. Baker, et al. "Measurements of volatile organic compounds at a suburban ground site (T1) in Mexico City during the MILAGRO 2006 campaign: measurement comparison, emission ratios, and source attribution." Atmospheric Chemistry and Physics 11, no. 6 (March 16, 2011): 2399–421. http://dx.doi.org/10.5194/acp-11-2399-2011.

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Abstract. Volatile organic compound (VOC) mixing ratios were measured with two different instruments at the T1 ground site in Mexico City during the Megacity Initiative: Local and Global Research Observations (MILAGRO) campaign in March of 2006. A gas chromatograph with flame ionization detector (GC-FID) quantified 18 light alkanes, alkenes and acetylene while a proton-transfer-reaction ion-trap mass spectrometer (PIT-MS) quantified 12 VOC species including oxygenated VOCs (OVOCs) and aromatics. A GC separation system was used in conjunction with the PIT-MS (GC-PIT-MS) to evaluate PIT-MS measurements and to aid in the identification of unknown VOCs. The VOC measurements are also compared to simultaneous canister samples and to two independent proton-transfer-reaction mass spectrometers (PTR-MS) deployed on a mobile and an airborne platform during MILAGRO. VOC diurnal cycles demonstrate the large influence of vehicle traffic and liquid propane gas (LPG) emissions during the night and photochemical processing during the afternoon. Emission ratios for VOCs and OVOCs relative to CO are derived from early-morning measurements. Average emission ratios for non-oxygenated species relative to CO are on average a factor of ~2 higher than measured for US cities. Emission ratios for OVOCs are estimated and compared to literature values the northeastern US and to tunnel studies in California. Positive matrix factorization analysis (PMF) is used to provide insight into VOC sources and processing. Three PMF factors were distinguished by the analysis including the emissions from vehicles, the use of liquid propane gas and the production of secondary VOCs + long-lived species. Emission ratios to CO calculated from the results of PMF analysis are compared to emission ratios calculated directly from measurements. The total PIT-MS signal is summed to estimate the fraction of identified versus unidentified VOC species.

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He, Li Ping, Xuan Luo, Fang Yu, Zhi Jun Wei, Dong Xiao Liu, Zhang Lin, and Li Xin. "Measurement on Light Yield of Liquid Scintillator Based on P-Xylene." Applied Mechanics and Materials 513-517 (February 2014): 4185–87. http://dx.doi.org/10.4028/www.scientific.net/amm.513-517.4185.

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The relative light output of liquid scintillator based on p-xylene (PX) was measured in this paper. The setup for testing on light output was clearly displayed. The results showed that the light yield increased as the addition of the second solute p-bis (o-methylatyryl)- benzene (bis-MSB). Bis-MSB moves the maxmun of fluorescence emission spectra of liquid scintillator from 365nm to 425nm, which is the most sensitive region for the PMT, so the possibility of self-absorption and the loss of light output could be reduced to some extent.

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44

Kim, Gunzung, Imran Ashraf, Jeongsook Eom, and Yongwan Park. "Concurrent Firing Light Detection and Ranging System for Autonomous Vehicles." Remote Sensing 13, no. 9 (May 1, 2021): 1767. http://dx.doi.org/10.3390/rs13091767.

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We proposed a light detection and ranging (LIDAR) system that changes the measurement strategy from a LIDAR system of sequential emission and measuring method to a concurrent firing measuring method. The proposed LIDAR was a 3D scanning LIDAR method that consisted of 128 output channels in one vertical line in the measurement direction and concurrently measured the distance for each of these 128 channels. The scanning LIDAR emitted 128 laser pulse streams encoded by carrier-hopping prime code (CHPC) technology with identification and checksum. When the reflected pulse stream was received and demodulated, the emission channel could be recognized. This information could be used to estimate the time when the laser pulse stream was emitted and calculate the distance to the object reflecting the laser. By using the identification of the received reflected wave, even if several positions were measured at the same time, the measurement position could be recognized after the reception. Extensive simulations indicated that the proposed LIDAR could provide autonomous vehicles or autonomous walking robots with good distance images to recognize the environment ahead.

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45

Berg, N., J. Mellqvist, J. P. Jalkanen, and J. Balzani. "Ship emissions of SO2 and NO2: DOAS measurements from airborne platforms." Atmospheric Measurement Techniques 5, no. 5 (May 15, 2012): 1085–98. http://dx.doi.org/10.5194/amt-5-1085-2012.

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Abstract. A unique methodology to measure gas fluxes of SO2 and NO2 from ships using optical remote sensing is described and demonstrated in a feasibility study. The measurement system is based on Differential Optical Absorption Spectroscopy using reflected skylight from the water surface as light source. A grating spectrometer records spectra around 311 nm and 440 nm, respectively, with the telescope pointed downward at a 30° angle from the horizon. The mass column values of SO2 and NO2 are retrieved from each spectrum and integrated across the plume. A simple geometric approximation is used to calculate the optical path. To obtain the total emission in kg h−1 the resulting total mass across the plume is multiplied with the apparent wind, i.e. a dilution factor corresponding to the vector between the wind and the ship speed. The system was tested in two feasibility studies in the Baltic Sea and Kattegat, from a CASA-212 airplane in 2008 and in the North Sea outside Rotterdam from a Dauphin helicopter in an EU campaign in 2009. In the Baltic Sea the average SO2 emission out of 22 ships was (54 ± 13) kg h−1, and the average NO2 emission was (33 ± 8) kg h−1, out of 13 ships. In the North Sea the average SO2 emission out of 21 ships was (42 ± 11) kg h−1, NO2 was not measured here. The detection limit of the system made it possible to detect SO2 in the ship plumes in 60% of the measurements when the described method was used. A comparison exercise was carried out by conducting airborne optical measurements on a passenger ferry in parallel with onboard measurements. The comparison shows agreement of (−30 ± 14)% and (−41 ± 11)%, respectively, for two days, with equal measurement precision of about 20%. This gives an idea of the measurement uncertainty caused by errors in the simple geometric approximation for the optical light path neglecting scattering of the light in ocean waves and direct and multiple scattering in the exhaust plume under various conditions. A tentative error budget indicates uncertainties within 30–45% but for a reliable error analysis the optical light path needs to be modelled. A ship emission model, FMI-STEAM, has been compared to the optical measurements showing an 18% overestimation and a correlation coefficient (R2) of 0.6. It is shown that a combination of the optical method with modelled power consumption can estimate the sulphur fuel content within 40%, which would be sufficient to detect the difference between ships running at 1% and at 0.1%, limits applicable within the IMO regulated areas.

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46

Mojżysz, Marzena, Adrianna Góra, Henryk Sechman, Piotr Guzy, and Anna Twaróg. "Methane and carbon dioxide emission measurements in selected area of the Polish Western Carpathians." E3S Web of Conferences 29 (2018): 00017. http://dx.doi.org/10.1051/e3sconf/20182900017.

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The paper presents measurement results of methane and carbon dioxide emission in Western Carpathians. The investigations were carried out with application of static chamber method in 10 stations. An emission and dynamics of changes within methane and carbon dioxide concentrations were examined by measuring the emission directly from the land surface as well as after drilling an additional hole. In total, 40 gas samples were taken, which were then subjected to chromatographic analysis. The measurements of methane and carbon dioxide emission have not shown significant emission values of these gases. The average value of methane emission from soil to the atmosphere at selected measurement sites was -0.451 mg*m-2*d-1, while the average methane emission with the use of the hole, equalled to -0.361 mg*m-2*d-1. The changes of carbon dioxide concetration were opposite. Higher emission of this gas was showed due to its natural escaping to the atmosphere with an average concetration of 1829,3 mg*m-2*d-1. Conducted studies show that methane and carbon dioxide emission are low in the studied area. It does not confirm the elevated values of light hydrocarbons and associated components which were previously recorded in the soil gas samples.

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Genberg, J., H. A. C. Denier van der Gon, D. Simpson, E. Swietlicki, H. Areskoug, D. Beddows, D. Ceburnis, et al. "Light absorbing carbon in Europe – measurement and modelling, with a focus on residential wood combustion emissions." Atmospheric Chemistry and Physics Discussions 13, no. 4 (April 4, 2013): 9051–105. http://dx.doi.org/10.5194/acpd-13-9051-2013.

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Abstract. The atmospheric concentration of elemental carbon (EC) in Europe during the six-year period 2005–2010 has been simulated with the EMEP MSC-W model. The model bias compared to EC measurements is less than 20% for most of the examined sites. The model results suggest that fossil fuel combustion is the dominant source of EC in most of Europe but there are important contributions also from residential wood burning during the cold seasons and, during certain episodes, also from open biomass burning (wildfires and agricultural fires). The modelled contributions from open biomass fires to ground level concentrations of EC is small at the sites included in the present study, < 3% of the long-term average of EC in PM10. The modelling of this EC-source is subject to many uncertainties and for some episodes it is likely underestimated. EC measurements and modelled EC were also compared to optical measurements of black carbon (BC). The relationships between EC and BC (as given by mass absorption cross section, MAC values) differed widely between the sites, and the correlation between observed EC and BC is sometimes poor, making it difficult to compare results using the two techniques and limiting the comparability of BC measurements to model EC results. A new bottom-up emission inventory for carbonaceous aerosol from residential wood combustion has been applied. For some countries the new inventory has substantially different EC emissions compared to earlier estimates. For Northern Europe the most significant changes are much lower emissions in Norway and higher emissions in neighbouring Sweden and Finland. For Norway and Sweden, comparison to source-apportionment data from winter campaigns indicate that the new inventory may improve model calculated EC from wood burning. Finally, three different model setups were tested with variable atmospheric lifetimes of EC in order to evaluate the model sensitivity to the assumptions regarding hygroscopicity and atmospheric ageing of EC. The standard ageing scheme leads to a rapid transformation of the emitted hydrophobic EC to hygroscopic particles and generates similar results as assuming that all EC is aged at the point of emission. Assuming hydrophobic emissions and no ageing leads to higher EC concentrations. For the more remote sites, the observed EC concentration was in between the modelled EC using standard ageing and the scenario treating EC as hydrophobic. This could indicate too rapid EC ageing in the model in relatively clean parts of the atmosphere.

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48

Young, Ralph H., and Marina E. Kondakova. "P-146: Optical Measurement of the Emission Zone in Organic Light-Emitting Diodes." SID Symposium Digest of Technical Papers 40, no. 1 (2009): 1669. http://dx.doi.org/10.1889/1.3256646.

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Uehara, Y., M. Kuwahara, and S. Katano. "Measurement of phonon energy of Sb2Te3 by scanning tunneling microscope light-emission spectroscopy." Solid State Communications 177 (January 2014): 29–32. http://dx.doi.org/10.1016/j.ssc.2013.08.019.

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SASAGAWA, Takashi, Akihiro KAKISHIMA, Tsuyoshi SUZUKI, Koji YOSHIDA, and Hideo SHOJI. "Experimental Research of the Light Emission Intensity Measurement in a Spark Ignition Engine." Proceedings of Autumn Conference of Tohoku Branch 2003.39 (2003): 209–10. http://dx.doi.org/10.1299/jsmetohoku.2003.39.209.

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Journal articles on the topic 'Light emission measurement'

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