16 results on '"Energy Fraction"'
Search Results
2. Prediction of RCCI combustion fueled with CNG and algal biodiesel to sustain efficient diesel engines using machine learning techniques
- Author
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Elumalai Ramachandran, Ravi Krishnaiah, Elumalai Perumal Venkatesan, Satyajeet Parida, Siva Krishna Reddy Dwarshala, Sher Afghan Khan, Mohammad Asif, and Emanoil Linul
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CNG fuel ,Microalgae biodiesel ,Energy fraction ,RCCI combustion ,Machine learning techniques ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
This study used microalgae biodiesel as a high-reactive fuel directly injected along with various Compressed Natural Gas (CNG) energy shares (10, 20, 30, and 40%) as low-reactive fuel injected into the intake system. The experiments are performed in a single-cylinder, water-cooled, 1500 rpm, 3.5 kW power Compression Ignition (CI) engine under various loading conditions to examine the effects of CNG energy share on performance and emissions in Reactivity Controlled Compression Ignition (RCCI) combustion mode. The study found that the 30%CNG share decreased Nitrogen oxides (NOx) and smoke by 25 and 31%, as well as an increase in thermal efficiency of 4.35% in comparison to traditional biodiesel combustion. Finally, two machine learning (ML) models, namely the Gradient Boosting Regressor (GBR) and LASSO (Least Absolute Shrinkage and Selection Operator) Regression, were developed for predicting the dependent variables individually from the independent variables. Both the LASSO and GBR models achieved high accuracy with R2 values of 0.98–0.99 and relatively low Root Mean Square Error (RMSE) values.
- Published
- 2023
- Full Text
- View/download PDF
3. Evaluating thermal performance of a basin type modified active solar still.
- Author
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Sandeep, Kumar, Sudhir, and Dwivedi, Vijay Kumar
- Subjects
SOLAR stills ,HEAT transfer coefficient ,WATER depth ,WATER transfer - Abstract
In this paper, an attempt has been made to compare the thermal performance of a modified solar still with that of a conventional single slope basin type active solar still in the summer climatic conditions. Comparison has been made on the basis of theoretical performance indicators like internal heat transfer coefficients and energy fractions. Dunkle's model has been utilized to assess internal heat transfer coefficients at different water depths. Values of various heat transfer coefficients for the modified still are observed superior to the conventional solar still. At 0.01 m water depth, daily average value of evaporative heat transfer coefficient for modified still is observed 13.9% higher than that for the conventional still. Average values of radiative coefficient and convective coefficient for modified still are also higher by 3.5% and 4.5% respectively than those of conventional still. Reliance on different heat transfer coefficients on water depth in the still is likewise analyzed. The modified still has demonstrated on an average 42.85% higher daily evaporative heat transfer coefficient at 0.01 m water depth in comparison to its value at 0.03 m depth. With the increment in water depth (from 0.01 m to 0.03 m), there is a marginal variation in convective coefficient. The energy fractions are also figured and compared. The distillate yield count utilizing thermal model has additionally been done and compared with the experimental results. Theoretical and experimental results are observed to be in close proximities. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
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4. Ion current sensing-based lean blowout detection for a pulse combustor.
- Author
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Li, Fangyan, Xu, Lijun, Du, Minglong, Yang, Lijun, and Cao, Zhang
- Subjects
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COMBUSTION chambers , *COMBUSTION engineering , *TIME-domain analysis , *SPECTRAL energy distribution , *COMBUSTION - Abstract
In this paper an ion current sensing method is proposed for early detection of lean blowout (LBO) in a pulse combustor. The method was also compared with the pressure measurement method. Near LBO characteristics in the pulse combustor were inferred from ion current and pressure time domain signals recorded for different operating conditions and initially analyzed using the spectral analysis method. As LBO approached, low frequency (below 20 Hz) components were gradually observed and the spectral energy between 0 and 20 Hz gradually increased while the energy of the working frequency components decreased. The ratio of the working frequency components energy fraction over the low frequency components energy fraction could thus be treated as an indicator of LBO, denoted by stability to instability ratio ( SIR ). The index SIR remained at a high level under stable conditions and decreased steeply when LBO was approached. Based on the ion current sensing method and the prediction index SIR , the gas supply pressure for stable operation in the pulse combustor was suggested to be more than 15.2 kPa. The result shows that the proposed ion current sensing method and the index SIR can help to estimate the LBO limit of the pulse combustor and avert the unexpected LBO. Compared to pressure sensing, ion current sensing was observed to be more sensitive to LBO events, leaving sufficient time for combustion control. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
5. Particle Size Measurement in Gas-Solid Two-Phase Flow Using Acoustic Sensors.
- Author
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Miao Guo, Yong Yan, Yonghui Hu, Duo Sun, Xiangcheng Qian, and Xiaojuan Han
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PARTICLE size determination , *TWO-phase flow , *ACOUSTIC transducers , *WAVELETS (Mathematics) , *ARTIFICIAL neural networks , *GAS-solid interfaces , *DECOMPOSITION method , *SMOOTHNESS of functions - Abstract
Acoustic Emission (AE) technology is a promising way to non-intrusively measure the size of particles in pneumatic conveying pipelines. In AE-based particle sizing, extracting representative features from an AE signal and establishing the relationship between the features and particle size are essential. In this paper, AE signals from particles of different sizes are collected from a gas-solid flow test rig. Wavelet analysis is used to denoise the signals. The denoising performance of different wavelet parameters (wavelet function, decomposition level and thresholding) is compared based on signal-to-noise ratio and signal smoothness. The particle size is predicted through a neural network with energy fraction features extracted through wavelet analysis as the network inputs. Experimental results demonstrate that the relative error of the particle sizing system is no greater than 23%. [ABSTRACT FROM AUTHOR]
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- 2014
- Full Text
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6. A novel hybrid energy fraction and entropy-based approach for systolic heart murmurs identification.
- Author
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Zheng, Yineng, Guo, Xingming, and Ding, Xiaorong
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ENTROPY (Information theory) , *HEART murmurs , *COMPUTER user identification , *SUPPORT vector machines , *HEART auscultation - Abstract
This paper presents a set of novel features of heart sound for the detection of the abnormality of heart sounds and classification of heart murmurs. The features include energy fraction of the first and the second heart sounds ( S 1– S 2 EF ), energy fraction of heart murmur ( HMEF ), the maximum energy fraction of heart sound frequency sub-band ( HSEFmax ), sample entropy of the first and the second heart sounds component ( S 1– S 2 sampen ) and sample entropy of heart murmur component ( HMsampen ). Firstly, the heart sound signals were de-noised and normalized, then decomposed by wavelet packet. The features, such as energy fraction and sample entropy were calculated from the reconstructed selective frequency components of heart sound signals. The support vector machine (SVM) was employed as a classifier to detect the abnormality of heart sound and discriminate heart murmurs. A dataset consisting of 80 normal heart sounds and 167 systolic heart murmurs samples, segmented from 40 healthy volunteers and 67 patients, were used to test and validate the proposed method. The performance of our proposed method was assessed in terms of sensitivity, specificity and accuracy. The result showed that our proposed method exhibited a satisfactory performance with a high accuracy of 97.17%, a specificity of over 98.55% and a sensitivity of over 93.48%. This suggests that the presented method can be used as an effective assistance for cardiac auscultation. [ABSTRACT FROM AUTHOR]
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- 2015
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7. Evaluation of PV Generator Performance and Energy Supplied Fraction of the 120 kWp PV Microgrid System in Thailand.
- Author
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Chimtavee, Amnaj, Ketjoy, Nipon, Sriprapha, Kobsak, and Vaivudh, Sarayooth
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POWER resources ,PERFORMANCE evaluation ,ELECTRIC generators ,RENEWABLE energy sources ,ELECTRON tube grids ,SOLAR radiation ,ENERGY consumption - Abstract
Abstract: Normally, the main generators of microgrid system use controllable energy resources such as fossil fuel, biomass, biogas, hydro, etc for uncomplicated control. However, it is very challenging to control the microgrid system that uses uncontrollable energy resources such as solar and wind for main generators of microgrid system because they have many advantages. From this point, the PV microgrid system is constructed and operated at School of Renewable Energy Technology (SERT), Naresuan University for research and development of the microgrid system that is supplying 50% of total electricity demand by PV main generator. By measuring the important parameters such as solar irradiance, PV array voltage, PV array current, and AC electrical power, these data were collected for a year from November 2008 to October 2009 to use in evaluation processes. The PV generator evaluation result is revealed that the average reference yield (Yr), array yield (YA), and final yield (Yf) are 5.21, 4.32, and 3.84 kWh/kWp day respectively. The average total loss of the PV generator is 26.27% that comes from summing up the average capture losses (LC) 17.21% and average system losses (LS) 9.06%. The average overall PV plant efficiency (ηtot) is 10.41%, and the average performance ratio (PR) is 73.45%. While considering the system efficiency of the PV generator at various solar irradiance, we found that it has the lowest efficiency when the solar irradiance is in the range 0 - 0.10kW/m2, its efficiency increases with the increasing in the solar irradiance from 0.10 to 0.35kW/m2, the efficiency becomes highest when the solar irradiance in the range of 0.35 to 0.65kW/m2, and its efficiency decreases slowly when the solar irradiance is in the range of 0.65 to 1.30kW/m2. For energy supplied fraction of the microgrid, it can achieve the PV generator producing target by PV generator and external grid supplying 73% and 27% of the total load of the microgrid. [Copyright &y& Elsevier]
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- 2011
- Full Text
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8. Aspects of Track-Assisted Mass
- Author
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Jesse Thaler and Benjamin T. Elder
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,Large Hadron Collider ,Energy Fraction ,010308 nuclear & particles physics ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,QCD Phenomenology ,01 natural sciences ,Charged particle ,High Energy Physics - Experiment ,High Energy Physics - Experiment (hep-ex) ,Formalism (philosophy of mathematics) ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,Jets ,0103 physical sciences ,lcsh:QC770-798 ,Direction information ,lcsh:Nuclear and particle physics. Atomic energy. Radioactivity ,High Energy Physics::Experiment ,010306 general physics ,Parton shower - Abstract
Track-assisted mass is a proxy for jet mass that only uses direction information from charged particles, allowing it to be measured at the Large Hadron Collider with very fine angular resolution. In this paper, we introduce a generalization of track-assisted mass and analyze its performance in both parton shower generators and resummed calculations. For the original track-assisted mass, the track-only mass is rescaled by the charged energy fraction of the jet. In our generalization, the rescaling factor includes both per-jet and ensemble-averaged information, facilitating a closer correspondence to ordinary jet mass. Using the track function formalism in electron-positron collisions, we calculate the spectrum of generalized track-assisted mass to next-to-leading-logarithmic order with leading-order matching. These resummed calculations provide theoretical insight into the close correspondence between track-assisted mass and ordinary jet mass. With the growing importance of jet grooming algorithms, we also calculate track-assisted mass on soft-drop groomed jets., 35+17 pages, 22 figures; v3: improvements to calculation and presentation to appear in JHEP
- Published
- 2018
9. Simulation of shock initiation in explosives using a model combining high computational efficiency with a free choice of mixture rules
- Author
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Feichao Miao, Tongtang Cao, Lin Zhou, and Xiangrong Zhang
- Subjects
Materials science ,Nitromethane ,Energy Fraction ,Explosive material ,Energy transfer ,Astrophysics::High Energy Astrophysical Phenomena ,General Physics and Astronomy ,02 engineering and technology ,Mechanics ,021001 nanoscience & nanotechnology ,01 natural sciences ,lcsh:QC1-999 ,010305 fluids & plasmas ,Universality (dynamical systems) ,chemistry.chemical_compound ,chemistry ,Homogeneous ,0103 physical sciences ,Volume fraction ,0210 nano-technology ,lcsh:Physics - Abstract
Models for shock initiation in explosives must consider how energy transfers from products to reactants. This is based on different energy-apportionment assumptions, which affect the results for shock initiation. This study proposes a robust model of shock initiation in explosives using a free choice of energy-apportionment assumptions. The reacting explosive is treated as a mixture of reactants and products under different energy-apportionment assumptions. The equations of state of the mixture are efficiently solved by refining the Cochran–Chan concept of the real volume fraction and introducing a real energy fraction term. The validity, efficiency, and universality of the proposed model are verified in one-dimensional numerical simulations of the shock initiation of homogeneous (nitromethane) and heterogeneous (PBX 9404) explosives. Compared to the conventional Cochran–Chan and Johnson–Tang–Forest models, the proposed model has a better balance of computational efficiency and universality.
- Published
- 2018
10. Off-diagonal helicity density matrix elements for heavy vector mesons inclusively produced in N-N, gamma-N, l-N interactions
- Author
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M. Bertini, Francesco Murgia, Bernard Pire, and M. Anselmino
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Quark ,Density matrix ,Physics ,Nuclear and High Energy Physics ,Particle physics ,Meson ,Energy Fraction ,Diagonal ,High Energy Physics::Phenomenology ,Nuclear Theory ,FOS: Physical sciences ,hep-ph ,Helicity ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,High Energy Physics::Experiment ,Nuclear Experiment - Abstract
Final state interactions in quark fragmentation may give origin to non zero values of the off-diagonal element rho_(1,-1) of the helicity density matrix of vector mesons V produced in current jets, with a large energy fraction x_E; the value of rho_(1,-1)(V) is related to the hard constituent dynamics and tests unusual properties of it. Some recent data on phi, K^* and D^* produced in e^+ e^- annihilations at LEP show such effects. Predictions are given here for rho_(1,-1) of heavy mesons produced in nucleon-nucleon, gamma-nucleon and lepton-nucleon interactions., Comment: LaTeX, 10 pages, 1 postscript figure, uses epsfig.sty. Revised version, to be published on Phys. Lett. B. Some statements added to clarify text
- Published
- 2015
11. Separation of energy fractions of an electron beam by a localized nonuniformity of magnetic field in the collector region of gyrodevices
- Author
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Glyavin, M. Yu., Morozkin, M. V., and Petelin, M. I.
- Published
- 2006
- Full Text
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12. Energetic efficiency of protein and body fat retention in crossbred Bos indicus and Bos Taurus × Bos indicus raised under tropical conditions
- Author
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Douglas Sampaio Henrique, Ricardo Augusto Mendonça Vieira, Mosar Faria Botelho, and Cesar de Queiroz
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Mathematical models ,Energy Fraction ,business.industry ,Beef-cattle ,modelos matemáticos ,Energy metabolism ,Beef cattle ,Biology ,Bioenergetics ,Crossbreed ,humanities ,bovinos de corte ,Biotechnology ,bioenergética ,Animal science ,Animal Science and Zoology ,Protein retention ,business ,Dietary fat - Abstract
The efficiency of fat and protein retention by Bos indicus and its cross-breds was estimated from data obtained in the literature to verify possible differences between these animals and Bos taurus. After estimating the efficiencies, a correction factor was used to discount the metabolizable energy fraction that was spent in the maintenance and support metabolism processes. The efficiencies were then estimated again, assuming that all the remaining energy would correspond to the metabolizable energy available for body mass retention. The correction value used was considered satisfactory to discount energetic losses for maintenance and support. The efficiency values of partial body fat and protein retention in Bos indicus and its cross-bred were very similar to values reported by other authors who researched Bos taurus exclusively. A eficiência com que animais zebuínos e seus cruzamentos transformam a energia metabolizável consumida em gordura e proteína corporal foi estimada a partir de informações obtidas na literatura no intuito de verificar se existem diferenças entre esses animais e os de raças europeias. Após a estimativa das eficiências, usou-se uma correção para descontar a porção da energia metabolizável gasta na manutenção da massa corporal e no metabolismo de suporte. Posteriormente à aplicação da correção, as eficiências foram estimadas novamente, partindo-se do pressuposto de que o montante de energia restante corresponderia à energia metabolizável utilizada para acúmulo de massa corporal. O valor de correção utilizado foi considerado suficiente para descontar as perdas energéticas para mantença e suporte. Os valores de eficiência de retenção parcial de gordura e proteína corporal em animais zebuínos e mestiços Europeu × Zebu são muito próximos dos encontrados por outros autores em pesquisas com animais exclusivamente europeus.
- Published
- 2009
13. Relationship between room shape and acoustics of rectangular concert halls
- Author
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Anders Christian Gade and Andrzej K. Klosak
- Subjects
Acoustics and Ultrasonics ,Energy Fraction ,Acoustics ,0211 other engineering and technologies ,Regression analysis ,02 engineering and technology ,computer.software_genre ,01 natural sciences ,Simulation software ,Arts and Humanities (miscellaneous) ,021105 building & construction ,0103 physical sciences ,010301 acoustics ,computer ,Mathematics - Abstract
Extensive acoustics computer simulations have been made using Odeon computer simulation software. In 24 rectangular rooms representing "shoe‐box" type concert halls with volumes of 8 000 m3, 12 000 m3 and 16 000 m3 from 300 to 850 measurements positions have been analysed. Only room averaged objective measures are considered here, in particular Clarity (C80), Strength (G) and Early Lateral Energy Fraction (LF80). Results from simulations have been compared with regression models created based on real hall measurements. In general, simulated results of C80 and G are found to be in good agreement with regression models. Divergences are found in LF80 behaviour; these have been associated with influence of proportions of rectangular halls. Updated formula for predicting of LF80 in rectangular halls has been proposed, which takes into the account both width and length of hall.
- Published
- 2008
14. Subjective relevance of objective measures for spatial impression (A)
- Author
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Lily M. Wang and Anders Gade
- Subjects
business.product_category ,Acoustics and Ultrasonics ,Arts and Humanities (miscellaneous) ,Energy Fraction ,Speech recognition ,Acoustics ,Relevance (information retrieval) ,Room acoustics ,business ,Binaural recording ,Headphones ,Impression ,Mathematics - Abstract
Several objective measures have been proposed to describe the feeling of spatial impression in concert halls, including Lateral Energy Fraction (LF) and Interaural Cross‐Correlation Coefficient (IACC). However, previous studies have shown that LF and IACC values did not highly correlate with each other at individual seat positions in real halls [J. S. Bradley, J. Acoust. Soc. Am. 96, 3525–3535 (1994)]. To investigate the listener envelopment aspect of spatial impression further, subjective paired‐comparison tests have been run using signals which have various values for LF, early IACC (from 5–80 ms), late IACC (from 80 ms–1 s), and late lateral relative sound level (GLL). Another proposed measure, called Interaural Level Fluctuations (IALF), has also been included, which is based on the rate of change over time of the level difference between the ears. The binaural test signals were generated by the room acoustics simulation program ODEON, using four different musical motifs, and were presented to test subjects via headphones. Results from the experiments are presented. [Work supported by ASA Hunt Postdoctoral Research Fellowship.]
- Published
- 2000
15. Inelastic Photoproduction at HERA: a Second Charmonium Crisis?
- Author
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Oscar J.P. Eboli, Eduardo De Moraes Gregores, and Francis Halzen
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,Octet ,Energy Fraction ,High Energy Physics::Lattice ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,High Energy Physics::Experiment ,Singlet state ,HERA - Abstract
The measurement of the inelastic photoproduction of charmonium at HERA seems to have ignited a new charmonium crisis. The (already discredited) color singlet model fits the data for large charmonium energy fraction z, where the NRQCD model qualitatively fails. We here point out that by the straightforward inclusion of color singlet and octet processes in the soft color (color evaporation) scheme, the HERA data can be accommodated for all z. We anticipate that the color singlet model will fail at low z, as it does in hadroproduction., 10 pages, Revtex, uses epsfig.sty to include 4 postscript figures. Also available from the UW-Madison Phenomenology preprint archives at http://pheno.physics.wisc.edu/pub/preprints/1998/madph-98-1045.ps.Z or at ftp://pheno.physics.wisc.edu/pub/preprints/1998/madph-98-1045.ps.Z
- Published
- 1998
16. Fragmentation function for charmed quarks from neutrino data
- Author
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R. Odorico and V. Roberto
- Subjects
Quark ,Physics ,Nuclear and High Energy Physics ,Particle physics ,Energy Fraction ,Meson ,Physics::Instrumentation and Detectors ,High Energy Physics::Phenomenology ,Hadron ,Nuclear physics ,Fragmentation function ,High Energy Physics::Experiment ,Neutrino ,Nuclear Experiment ,Particle Physics - Phenomenology - Abstract
Data on μ+μ− and μ−e+ events from the CERN-Dortmund-Heidelberg-Saclay and Columbia-BNL neutrino experiments, respectively, are employed to determine the fragmentation function for charmed quarks. It is found that the data are all well described by a flat fragmentation function D(z) (where z is the energy fraction taken by the charmed meson), in agreement with the expectation from bremsstrahlung-type models. The data definitely exclude a behaviour ∼exp(−3z), typical of uncharmed hadrons, suggested by a previous phenomenological analysis. They also discriminate against the possibility that the fragmentation function is concentrated at large z, as predicted by fireball-type models.
- Published
- 1977
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