Effect of Flame Angle Using Various Swirler Angle in Combustion Performance

2015 ◽  
Vol 72 (4) ◽  
Author(s):  
Muhammad Roslan Rahim ◽  
Mohammad Nazri Mohd Jaafar
Keyword(s):  
Fossil Fuels ◽  
Swirling Flow ◽  
Combustion Process ◽  
Flame Length ◽  
Oxides Of Nitrogen ◽  
Photochemical Smog ◽  
No Emission ◽  
Blue Colour ◽  
The One ◽  
Short Time

The abbreviation N  is commonly used as a reference to all oxides of nitrogen and the examples of oxides of nitrogen are NO, N  and O. These emission gases mostly come from the combustions of fossil fuels and biofuels in industrial activities and also in road traffics globally. N  as a pollutant deserves special attention because of its various issues on human’s health and environment. Some of these issues are global warming, acid rain, ozone layer depletion and photochemical smog. To address these issues, some studies are concentrating on the reduction of NO emission from the combustion process. This paper describes a study in the effects of swirling flow generated by using a radial swirler on flame characteristics that is related to the emission of NO. The radial swirlers used in this study have the angles of 40°, 50° and 60°. Diesel is used as a fuel in this study. The results show that all radial swirlers used have different effects on the flame characteristics. From all these radial swirlers, the one with an angle of 60° produces flame with high temperature, short flame length with blue colour and wide spread. The results also show a short time residence during combustion process that could reduce the formation of CO and N . 

KESAN SUDUT PUSARAN TERHADAP PEMBAKARAN MENGGUNAKAN PEMUSAR JEJARIAN DWI ALIRAN

2015 ◽  
Vol 77 (8) ◽  
Author(s):  
Muhammad Roslan Rahim ◽  
Mohammad Nazri Mohd Ja’afar
Keyword(s):  
Swirling Flow ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Flame Length ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Flame Stability ◽  
Wide Spread ◽  
Blue Colour ◽  
The One

Development of combustion systems which involves retrofitting or design of new burners, is made to reduce the formation of pollutant emissions. The reduction of this pollutant emission results from the complete mixing of fuel and air during the combustion process. Meanwhile, non-complete mixing of fuel and air during combustion process can cause ignition problem and create problems in terms of flame stability and combustion efficiency. This article describes a study on the effects of swirling flow generated by a double radial swirler on flame characteristics that is related to the emission of NO. The double radial swirlers used in this study have the angles of 30°/40°, 30°/50° and 30°/60°. Diesel is used as a fuel in this study. The results show that all double radial swirlers used have different effects on the flame characteristics and temperature profile. From all these double radial swirlers, the one with an angle of 30°/60° produces flame with high temperature, short flame length with blue colour and wide spread.

scholarly journals Nitrogen Oxides Emission Reduction using Sewage Sludge Gasification Gas Reburning Process / Obniżenie Emisji Tlenków Azotu Przy Użyciu Procesu Reburningu Gazem Ze Zgazowania Osadów Ściekowych

2015 ◽  
Vol 22 (1) ◽  
pp. 83-94
Author(s):  
Sebastian Werle
Keyword(s):  
Sewage Sludge ◽  
Nitrogen Oxides ◽  
Fossil Fuels ◽  
Main Product ◽  
Power Engineering ◽  
Hard Coal ◽  
Photochemical Smog ◽  
Reduction Efficiency ◽  
The One ◽  
Small Capacity

Abstract Nitrogen oxides can be formed in various combustion systems. Strategies for the control of NOx emissions in hard coal boilers include the primary (during the combustion) and secondary measures (after combustion). Reburning is the one of the most attractive techniques for reducing NOx emissions. In the last several years, reburning technology has been widely studied but almost only in power engineering big load boilers. Nevertheless, NOx emission is an issue that needs to be considered for small capacity boilers as nitrogen oxides resulting from the combustion of any fossil fuels contribute to the formation of acid rain and photochemical smog, which are significant causes of air pollution. Poland is among the largest coal producing country in Europe. Due to this fact, coal fired boilers are very popular in power engineering and also in the municipal sector. Simultaneously, Poland is characterized by the lack of sewage sludge thermal treatment installation. Gasification is considered as a one of the most perspective method of thermal utilization any carbon-containing material. Syngas, which is the main product of gasification, can be used as a supplemental fuel to reduce the consumption of main fuel in boilers, and it has the potential to reduce NOx emissions. The paper proposes to link those two Polish features so the aim of the work is an experimental investigation of the reburning process of sewage sludge gasification gas in a small capacity domestic coal-fired boiler. The results obtained show how the addition of the reburning fuel influences on NOx reduction efficiency

Global Warming and Its Multiple Causes

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Romdhane Ben Slama
Keyword(s):  
Global Warming ◽  
Greenhouse Gases ◽  
Greenhouse Effect ◽  
Infrared Radiation ◽  
Fossil Fuels ◽  
Ambient Air ◽  
The Earth ◽  
The One ◽  
Heat Released ◽  
Emission Of Greenhouse Gases

The global warming which preoccupies humanity, is still considered to be linked to a single cause which is the emission of greenhouse gases, CO2 in particular. In this article, we try to show that, on the one hand, the greenhouse effect (the radiative imprisonment to use the scientific term) took place in conjunction with the infrared radiation emitted by the earth. The surplus of CO2 due to the combustion of fossil fuels, but also the surplus of infrared emissions from artificialized soils contribute together or each separately,  to the imbalance of the natural greenhouse effect and the trend of global warming. In addition, another actor acting directly and instantaneously on the warming of the ambient air is the heat released by fossil fuels estimated at 17415.1010 kWh / year inducing a rise in temperature of 0.122 ° C, or 12.2 ° C / century.

Der Erzieher als Manager

2019 ◽  
Vol 95 (4) ◽  
pp. 517-530
Author(s):  
Diana Lohwasser
Keyword(s):  
Educational Process ◽  
The Other ◽  
Critical View ◽  
Other Hand ◽  
The One ◽  
Short Time ◽  
Time Diagnosis

Abstract The Educator as a Manager. A Critical View In the following article tasks and motifs of the educator as manager are described. It is clear that there are other educator metaphors and associated behaviors. To some extent, the actions of the different educator metaphors overlap, but they differ in their purpose and perspective on the educational process and the person to be educated. First, a short time diagnosis is made, which describes the context of this metaphor of the educator as manager. Subsequently, on the one hand, the various motifs, tasks and objectives of an educator as manager are discussed. On the other hand, it is asked if it is possible in the current discourse to take a different perspective on the educational process.

Extraction and Determination of Physico-chemical Properties of Oil from Watermelon Seeds (Citrullus lanatus L) to Use in Internal Combustion Engines

2017 ◽  
Vol 68 (11) ◽  
pp. 2676-2681
Author(s):  
Mihaela Gabriela Dumitru ◽  
Dragos Tutunea
Keyword(s):  
Fatty Acid ◽  
Internal Combustion Engines ◽  
Fossil Fuels ◽  
Citrullus Lanatus ◽  
Combustion Process ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Mean Diameter ◽  
Geometrical Mean ◽  
Reduction Of Nox

The purpose of this work was to investigate the physicochemical properties of watermelon seeds and oil and to find out if this oil is suitable and compatible with diesel engines. The results showed that the watermelon seeds had the maximum length (9.08 mm), width (5.71mm), thickness (2.0 mm), arithmetic mean diameter (5.59 mm), geometrical mean diameter (4.69 mm), sphericity (51.6%), surface area (69.07), volume 0.17 cm3 and moisture content 5.4%. The oil was liquid at room temperature, with a density and refractive index of 0.945 and 1.4731 respectively acidity value (1.9 mgNaOH/g), free fatty acid (0.95 mgNaOH), iodine value (120 mgI2/100g), saponification value (180 mgKOH/g), antiradical activity (46%), peroxide value (7.5 mEqO2/Kg), induction period (6.2 h), fatty acid: palmitic acid (13.1%), stearic acid (9.5 %), oleic acid (15.2 %) and linoleic acid (61.3%). Straight non food vegetable oils can offer a solution to fossil fuels by a cleaner burning with minimal adaptation of the engine. A single cylinder air cooled diesel engine Ruggerini RY 50 was used to measure emissions of various blends of watermelon oil (WO) and diesel fuel (WO10D90, WO20D80, WO30D70 and WO75D25). The physic-chemical properties of the oil influence the combustion process and emissions leading to the reduction of NOX and the increase in CO, CO2 and HC.

African Sustainability Advocacy Against Extractivism

2015 ◽  
Vol 3 (7) ◽  
Author(s):  
Patrick Bond
Keyword(s):  
Social Reproduction ◽  
Fossil Fuels ◽  
Social Economic ◽  
Social Activism ◽  
Ecological Factors ◽  
Energy Economics ◽  
Extractive Industries ◽  
The One ◽  
Political Economic ◽  
Critical Challenge

<p class="p1"><span class="s2"><strong>Abstract </strong></span>| The challenge of interdisciplinary intellectual and strategic work in the extractive industries is particularly acute at the interface of research and social activism. Numerous social movements which are dedicated to sustainability fail to ‘connect the dots’ between their campaigns and broader political-economic and political-ecological visions<span class="s3"><strong>. </strong></span>This is becoming a critical challenge in Africa, where the extreme damage done by mining and fossil fuels has generated impressive resistance<span class="s3"><strong>.</strong></span>However, the one obvious place to link these critiques from African activists was the Alternative Mining Indaba in Cape Town in February 2015, and a survey of narratives at that event leads to pessimism about interdisciplinary politics. The potential for much greater impact and deeper critiques of unsustainable extractivism lies in greater attention to combining social reproduction and production (as do eco-feminists), and to tackling social, economic, political and ecological factors with a more explicit structuralist critique and practical toolkit<span class="s3"><strong>. </strong></span>Areas such as energy, economics and climate are ripe for linkages<span class="s3"><strong>. </strong></span>One reason for optimism is a climate justice declaration made by leading civil society activists in Maputo in April 2015.<strong></strong></p>

scholarly journals Deep Learning Approach for Vibration Signals Applications

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3929
Author(s):  
Han-Yun Chen ◽  
Ching-Hung Lee
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Parameters Optimization ◽  
Frequency Spectra ◽  
Vibration Signals ◽  
Bearing Faults ◽  
Time Frequency ◽  
And Performance ◽  
The One ◽  
Short Time

This study discusses convolutional neural networks (CNNs) for vibration signals analysis, including applications in machining surface roughness estimation, bearing faults diagnosis, and tool wear detection. The one-dimensional CNNs (1DCNN) and two-dimensional CNNs (2DCNN) are applied for regression and classification applications using different types of inputs, e.g., raw signals, and time-frequency spectra images by short time Fourier transform. In the application of regression and the estimation of machining surface roughness, the 1DCNN is utilized and the corresponding CNN structure (hyper parameters) optimization is proposed by using uniform experimental design (UED), neural network, multiple regression, and particle swarm optimization. It demonstrates the effectiveness of the proposed approach to obtain a structure with better performance. In applications of classification, bearing faults and tool wear classification are carried out by vibration signals analysis and CNN. Finally, the experimental results are shown to demonstrate the effectiveness and performance of our approach.

scholarly journals COVID-19 Outbreak and CO2 Emissions: Macro-Financial Linkages

2020 ◽  
Vol 14 (1) ◽  
pp. 12
Author(s):  
Julien Chevallier
Keyword(s):  
Co2 Emissions ◽  
Fossil Fuels ◽  
Mixed Data ◽  
Energy Information Administration ◽  
Time Varying ◽  
Data Sampling ◽  
Quantitative Finance ◽  
Financial Variables ◽  
Mixed Data Sampling ◽  
The One

In the Dynamic Conditional Correlation with Mixed Data Sampling (DCC-MIDAS) framework, we scrutinize the correlations between the macro-financial environment and CO2 emissions in the aftermath of the COVID-19 diffusion. The main original idea is that the economy’s lock-down will alleviate part of the greenhouse gases’ burden that human activity induces on the environment. We capture the time-varying correlations between U.S. COVID-19 confirmed cases, deaths, and recovered cases that were recorded by the Johns Hopkins Coronavirus Center, on the one hand; U.S. Total Industrial Production Index and Total Fossil Fuels CO2 emissions from the U.S. Energy Information Administration on the other hand. High-frequency data for U.S. stock markets are included with five-minute realized volatility from the Oxford-Man Institute of Quantitative Finance. The DCC-MIDAS approach indicates that COVID-19 confirmed cases and deaths negatively influence the macro-financial variables and CO2 emissions. We quantify the time-varying correlations of CO2 emissions with either COVID-19 confirmed cases or COVID-19 deaths to sharply decrease by −15% to −30%. The main takeaway is that we track correlations and reveal a recessionary outlook against the background of the pandemic.

Acid Volatile Sulfide (AVS) and Simultaneously Extracted Metals (SEM) in Surface Sediments of Chaohu Lake, Anhui Province, China

2013 ◽  
Vol 779-780 ◽  
pp. 1213-1219
Author(s):  
Shu Qin Chen ◽  
Lei Zhang ◽  
Zhao Sheng Chu ◽  
She Rong Hu
Keyword(s):  
Surface Sediments ◽  
Local Scale ◽  
Acid Volatile Sulfide ◽  
Anthropogenic Factors ◽  
Chaohu Lake ◽  
Lake Surface ◽  
Different Seasons ◽  
The One ◽  
Short Time ◽  
Spot 5

At present there are few studies on the AVS and SEM in sediments of Chaohu Lake. Most of the previous studies on heavy metals based on the one time, the short-time or a local-scale survey. In this paper, [AVS] and [SEM] in Chaohu Lake surface sediments were studied for different seasons in 2007, 2008 and 2009. The results showed that: (a) The three-year average of [AV and [ΣSE in surface sediments of Chaohu Lake is 4.2μmolg-1and 2.31μmolg-1, respectively. The maximum of [AV appears on spot 5 (14.845μmolg-1) in summer while the minimum appears on spot 9 (0.13μmolg-1) in winter. (b) In spot 5 which near the estuary of Yuxi River, three-year average of [SE was the maximum (5.81μmolg-1), and the minimum of [ΣSE (0.07μmolg-1) appears on spot 8 which locates in the middle of Chaohu Lake. In spot 13 the [ΣSEM]-[AVS]=3.2>2 and [ΣSEM]/[AVS]=4.45>2.34 indicate that heavy metal contaminants from Hefei city have threatened the biosafety of Chaohu Lake. (c) The spatial autocorrelation of SEMCdis weak, which indicates that spatial distribution of SEMCdis determined by anthropogenic factors rather than sediments' own attribute. Chaohu Lake has been heavily polluted by Cd from no-point source and electronic electroplating industry.

CLASSICAL DIFFUSION AND QUANTAL LOCALIZATION OF A KICKED PARTICLE IN A WELL

1988 ◽  
Vol 02 (01) ◽  
pp. 103-120 ◽  
Author(s):  
AVRAHAM COHEN ◽  
SHMUEL FISHMAN
Keyword(s):  
Diffusion Coefficient ◽  
Classical Limit ◽  
Approximate Formula ◽  
Quantum Systems ◽  
Potential Well ◽  
Diffusive Growth ◽  
Classical Chaos ◽  
The One ◽  
Short Time ◽  
Infinite Potential Well

The classical and quantal behavior of a particle in an infinite potential well, that is periodically kicked is studied. The kicking potential is K|q|α, where q is the coordinate, while K and α are constants. Classically, it is found that for α > 2 the energy of the particle increases diffusively, for α < 2 it is bounded and for α = 2 the result depends on K. An approximate formula for the diffusion coefficient is presented and compared with numerical results. For quantum systems that are chaotic in the classical limit, diffusive growth of energy takes place for a short time and then it is suppressed by quantal effects. For the systems that are studied in this work the origin of the quantal localization in energy is related to the one of classical chaos.

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