scholarly journals Compact disks. An explanation to faint CO emission in Lupus disks

Author(s):  
A. Miotello ◽  
G. Rosotti ◽  
M. Ansdell ◽  
S. Facchini ◽  
C. F. Manara ◽  
...  
Keyword(s):  
2019 ◽  
Vol 13 (3) ◽  
pp. 5278-5293
Author(s):  
Vipul Patel ◽  
Rupesh Shah

The present research aims to analyse diffusion flame in a tube type burner with Liquefied petroleum gas (LPG) as a fuel. An experimental investigation is performed to study flame appearance, flame stability, Soot free length fraction (SFLF) and CO emission of LPG diffusion flame. Effects of varying air and fuel velocities are analysed to understand the physical process involved in combustion. SFLF is measured to estimate the reduction of soot. Stability limits of the diffusion flame are characterized by the blowoff velocity. Emission characteristic in terms of CO level is measured at different equivalence ratios. Experimental results show that the air and fuel velocity strongly influences the appearance of LPG diffusion flame. At a constant fuel velocity, blue zone increases and the luminous zone decreases with the increase in air velocity. It is observed that the SFLF increases with increasing air velocity at a constant fuel velocity. It is observed that the blowoff velocity of the diffusion flame increases as fuel velocity increases. Comparison of emission for flame with and without swirl indicates that swirl results in low emission of CO and higher flame stability. Swirler with 45° vanes achieved the lowest CO emission of 30 ppm at Φ = 1.3.


2017 ◽  
Vol DC CPS 2017 (01) ◽  
pp. 22-26 ◽  
Author(s):  
Elsie Chidinma Anderson ◽  
A. A. Obayi ◽  
K.C. Okafor

The swiftly growing urban population of Nigeria is generating lots of tension in the cities in line with the rapid increase of vehicles. This is due to hitherto reliance on the present parking system which has no standard to check for parking spaces, hence generating problems such as traffic congestion, time wastage in search of parking slot, fuel consumption/CO emission, insecurity of vehicles etc. This work presents a quantitative statistical survey analysis conducted in selected metropolitan cities in Port Harcourt, Nigeria. The aim is to create awareness on Smart Car Parking System (SCPS) for heterogeneous clustered environments. The results of the conducted analysis showed that the awareness of this innovative technology is still at its tender stage in Nigeria. Findings shows that people are willing to adopt this new technology to assist in overcoming the challenges faced in the present parking system that is unstructured. A brief description of proposed SCPS based on Big data hardware is presented.


2020 ◽  
Vol 20 (1) ◽  
pp. 83-98 ◽  
Author(s):  
Yongjoo Choi ◽  
Yugo Kanaya ◽  
Seung-Myung Park ◽  
Atsushi Matsuki ◽  
Yasuhiro Sadanaga ◽  
...  

Abstract. The black carbon (BC) and carbon monoxide (CO) emission ratios were estimated and compiled from long-term, harmonized observations of the ΔBC∕ΔCO ratios under conditions unaffected by wet deposition at four sites in East Asia, including two sites in South Korea (Baengnyeong and Gosan) and two sites in Japan (Noto and Fukuoka). Extended spatio-temporal coverage enabled estimation of the full seasonality and elucidation of the emission ratio in North Korea for the first time. The estimated ratios were used to validate the Regional Emission inventory in ASia (REAS) version 2.1 based on six study domains (“East China”, “North China”, “Northeast China”, South Korea, North Korea, and Japan). We found that the ΔBC∕ΔCO ratios from four sites converged into a narrow range (6.2–7.9 ng m−3 ppb−1), suggesting consistency in the results from independent observations and similarity in source profiles over the regions. The BC∕CO ratios from the REAS emission inventory (7.7 ng m−3 ppb−1 for East China – 23.2 ng m−3 ppb−1 for South Korea) were overestimated by factors of 1.1 for East China to 3.0 for South Korea, whereas the ratio for North Korea (3.7 ng m−3 ppb−1 from REAS) was underestimated by a factor of 2.0, most likely due to inaccurate emissions from the road transportation sector. Seasonal variation in the BC∕CO ratio from REAS was found to be the highest in winter (China and North Korea) or summer (South Korea and Japan), whereas the measured ΔBC∕ΔCO ratio was the highest in spring in all source regions, indicating the need for further characterization of the seasonality when creating a bottom-up emission inventory. At levels of administrative districts, overestimation in Seoul, the southwestern regions of South Korea, and Northeast China was noticeable, and underestimation was mainly observed in the western regions in North Korea, including Pyongyang. These diagnoses are useful for identifying regions where revisions in the inventory are necessary, providing guidance for the refinement of BC and CO emission rate estimates over East Asia.


1987 ◽  
Vol 115 ◽  
pp. 149-150
Author(s):  
K. Sugitani ◽  
Y. Fukui

We present new 13CO(J = 1-0) measurements of the Orion molecular cloud. The data were taken with the 4-m millimeter-wave telescope of Nagoya University with a beamwidth of 2.7′. The high velocity resolution of 0.1 km s−1 employed has revealed significant details of the 13CO emission toward the H II region.


2021 ◽  
Vol 13 (4) ◽  
pp. 1859
Author(s):  
Kadir Diler Alemdar ◽  
Ahmet Tortum ◽  
Ömer Kaya ◽  
Ahmet Atalay

Intersections are the most important regions in terms of urban traffic management. The intersection areas on the corridor should be analyzed together for consistency in traffic engineering. To do so, three intersections on the Vatan Street corridor in İstanbul, the most crowded city of Turkey, were examined. Various geometric and signal designs were performed for intersections and the most suitable corridor design was analyzed. The corridor designs were modeled with the PTV VISSIM microsimulation software. The most suitable corridor design was evaluated by using the results obtained from the microsimulation via analytical hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS) from multi criteria decision analysis (MCDA) methods. The evaluation criteria in the study are vehicle delay, queue length, stopped delay, stops, travel time, vehicle safety, CO emission, fuel consumption, and construction cost. As a result, the current and the most suitable alternative corridors were compared according to the comparison parameters and up to 80% improvements were observed. Thus, some advantages were obtained in terms of energy, environment, time, and cost.


Author(s):  
Takeshi Yamamoto ◽  
Kazuo Shimodaira ◽  
Seiji Yoshida ◽  
Yoji Kurosawa

The Japan Aerospace Exploration Agency (JAXA) is conducting research and development on aircraft engine technologies to reduce environmental impact for the TechCLEAN project. As a part of the project, combustion technologies have been developed with an aggressive target that is an 80% reduction over the NOx threshold of the ICAO CAEP/4 standard. A staged fuel nozzle with a pilot mixer and a main mixer was developed and tested using a single-sector combustor under the target engine’s LTO cycle conditions with a rated output of 40 kN and an overall pressure ratio of 25.8. The test results showed a 77% reduction over the CAEP/4 NOx standard. A reduction in smoke was found under a higher thrust condition than the 30% MTO condition, and a reduction in CO emission was found under a lower thrust condition than the 85% MTO condition. In the present study, an additional fuel burner was designed and tested with the staged fuel nozzle in a single-sector combustor to control emissions. The test results show that the combustor enables an 82% reduction in NOx emissions relative to the ICAO CAEP/4 standard and a drastic reduction in smoke and CO emissions.


1999 ◽  
Vol 51 (5) ◽  
pp. 653-662 ◽  
Author(s):  
Ikuru Iwata ◽  
Shin-ichiro Okumura ◽  
Mamoru Saitō

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