scholarly journals The Influence of Liquid Viscosity on Atomized Fuel Mean Droplet Size Determined by the Laser Diffraction Method

2018 ◽  
Vol 1 (1) ◽  
pp. 435-441
Author(s):  
Paweł Krause ◽  
Róbert Labuda

Abstract The article presents the impact of viscosity of fuel on its atomization, which constitutes an important element of controlling the quality of the fuel-air mixture in compression ignition and direct injection engines. An experiment has been made using a three-hole atomizer of an engine with nominal power of 110 kW and revolutions n = 2800 min−1. Fuel was delivered by a PRW-2M injection pump intended for testing injectors. Fuel was sprayed in the atmospheric air. Three petroleum product liquids used for the experiment had a viscosity of, respectively, 3.93, 16.73 and 36.41 mm2/s. The fuel droplet size in a spray was determined by the laser diffraction method by means of a Spraytec STP 5929 analyzer. The quantity adopted for comparative purposes was the Sauter Mean Diameter D32. The results confirmed that a change of fuel viscosity within the range recommended by ship engine manufacturers has a strong impact on the size of sprayed fuel droplets. Shipowners have a limited choice of low sulphur fuel grade (up to 0.1% S), which forces the engine room personnel to use currently available fuels. Depending on the supplier, marine fuels may vary in viscosity and, according to the recommendations of engine manufacturers, they do not require heating. The increase in the size of the droplets injected into the fuel combustion chamber may affect the quality of the fuel-air mixture, increase of fuel consumption and a greater content of harmful exhaust constituents.

2014 ◽  
Vol 17 (2) ◽  
Author(s):  
Germán Bianchini ◽  
Paola Caymes Scutari

Forest fires are a major risk factor with strong impact at eco-environmental and socio- economical levels, reasons why their study and modeling are very important. However, the models frequently have a certain level of uncertainty in some input parameters given that they must be approximated or estimated, as a consequence of diverse difficulties to accurately measure the conditions of the phenomenon in real time. This has resulted in the development of several methods for the uncertainty reduction, whose trade-off between accuracy and complexity can vary significantly. The system ESS (Evolutionary- Statistical System) is a method whose aim is to reduce the uncertainty, by combining Statistical Analysis, High Performance Computing (HPC) and Parallel Evolutionary Al- gorithms (PEAs). The PEAs use several parameters that require adjustment and that determine the quality of their use. The calibration of the parameters is a crucial task for reaching a good performance and to improve the system output. This paper presents an empirical study of the parameters tuning to evaluate the effectiveness of different configurations and the impact of their use in the Forest Fires prediction.


Author(s):  
Albert Sesé

Abstract Evidence generation by current Social and Health Sciences is coping with some important barriers that difficult credibility of scientific products. Information and communication technologies have a strong impact over social relationships in our postmodern societies. The incidence of post-truth in our context is generating a pernicious relativism, far from contrasting the information veracity. The aim of this paper is to analyze and discuss the challenges of research methods and statistical models, more specifically for Psychological research, taking into account the impact of novel techniques as big data and virtual reality. Special attention is also devoted to the discussion about statistical shortcomings of psychological research and to the reproducibility problem. Finally, some potential solutions are proposed to be applied in order to improve the quality of scientific evidence.


Author(s):  
BASSEY ISONG ◽  
EKABUA OBETEN

Object-oriented (OO) approaches of software development promised better maintainable and reusable systems, but the complexity resulting from its features usually introduce some faults that are difficult to detect or anticipate during software change process. Thus, the earlier they are detected, found and fixed, the lesser the maintenance costs. Several OO metrics have been proposed for assessing the quality of OO design and code and several empirical studies have been undertaken to validate the impact of OO metrics on fault proneness (FP). The question now is which metrics are useful in measuring the FP of OO classes? Consequently, we investigate the existing empirical validation of CK + SLOC metrics based on their state of significance, validation and usefulness. We used systematic literature review (SLR) methodology over a number of relevant article sources, and our results show the existence of 29 relevant empirical studies. Further analysis indicates that coupling, complexity and size measures have strong impact on FP of OO classes. Based on the results, we therefore conclude that these metrics can be used as good predictors for building quality fault models when that could assist in focusing resources on high risk components that are liable to cause system failures, when only CK + SLOC metrics are used.


2021 ◽  
Author(s):  
Daniele Sutherland W. Rizziolli ◽  
Ana Maria Ramos Miranda ◽  
Andressa Schimidt do Nascimento ◽  
Cristiane dos Santos Lima ◽  
Jade Menezes Maia ◽  
...  

Introduction: With the increase in life expectancy, there is an increase in Alzheimer’s Disease (AD). Characterized by being a degenerative and irreversible neurological disease, that leads to developing a dependence for daily activities. Objective:To analyze the impact of AD on the quality of life and daily activities of the elderly. Methodology:Integrative literature review, with bibliographic survey carried out on an international basis (PUBMED). Criteria for the selection of articles was: be published in English, in the period 2018-2020, available in full, whose theme was “Impacts on the quality of life that AD causes in the elderly”. Results: For the sample of this review 59 articles were selected, of which 48 articles were not specific to the topic, leaving a final sample of 11 articles included in the review. Identifying that AD has a strong impact on patient’s quality of life, such as reduced autonomy and dependence on daily activities. Conclusion: It was observed that there is a reduction in the quality of life of patients with AD, related to loss of autonomy and dependence in daily activities. Mesh- Terms: Degenerative Disease, Aged, Insanity.


Author(s):  
Miloš Ljubojević ◽  
Vojkan Vasković ◽  
Zdenka Babić ◽  
Dušan Starčević

Abstract: An increasing number of services and facilities that are of interest to users is based on video streaming. Technical characteristics of video have a strong impact on the quality of a video streaming service and its perception by users. The most important measure of quality, which focuses on the user, is the Quality of Experience (QoE). Given that video advertising is a typical video streaming application, it is necessary to analyze the effect of the change of video characteristics on the QoE. This paper examines the impact of resolution and frame rate change on the QoE level by using objective and subjective QoE metrics. It also looks at the possibility of mapping the objective QoE metrics into subjective ones, if the QoE in Internet video advertising is analyzed. It was demonstrated that the values obtained by the objective assessment of quality can be mapped to the results obtained by subjective assessment of quality when the quality of experience of linear in- stream video ads is analyzed. The results indicate that temporal aspects of video quality assessment, e.g. influence of resolution and frame rate change to the level of the QoE, can be achieved by implementation of objective methods. Therefore, quality of experience can be improved by the proper selection of video characteristics values.


2015 ◽  
Vol 36 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Antoni Jankowski ◽  
Mirosław Kowalski

Abstract The paper contains analysis of the impact on the quality of the fuel spray of droplets on the number and the value of the surface area of the droplets that have a direct impact on the efficiency of the combustion process. It presents a change in the level of toxic exhaust emissions with an increase in the so-called. Sauter Mean Diameter (SMD) of fuel droplets. The presented figures show that the increase in the average droplet diameter SMD in particular causes an increase of toxic exhaust gases emissions, i.e. mainly nitrogen oxides NO, carbon monoxide CO, hydrocarbons HC and Particulate Matter (PM). This tendency is not constant, because it is changing according to changes of the coefficient of equivalence Φ. For example, emissions of nitrogen oxides for the lean mixtures (Φ <1), with an increase in average droplet diameter increases, while now for the rich mixtures (Φ> 1), this trend is significantly changed, i.e. the level of this emission decreases.


2020 ◽  
pp. 146808742091844
Author(s):  
Chinmoy K Mohapatra ◽  
David P Schmidt ◽  
Brandon A Sforozo ◽  
Katarzyna E Matusik ◽  
Zongyu Yue ◽  
...  

The internal details of fuel injectors have a profound impact on the emissions from gasoline direct injection engines. However, the impact of injector design features is not currently understood, due to the difficulty in observing and modeling internal injector flows. Gasoline direct injection flows involve moving geometry, flash boiling, and high levels of turbulent two-phase mixing. In order to better simulate these injectors, five different modeling approaches have been employed to study the engine combustion network Spray G injector. These simulation results have been compared to experimental measurements obtained, among other techniques, with X-ray diagnostics, allowing the predictions to be evaluated and critiqued. The ability of the models to predict mass flow rate through the injector is confirmed, but other features of the predictions vary in their accuracy. The prediction of plume width and fuel mass distribution varies widely, with volume-of-fluid tending to overly concentrate the fuel. All the simulations, however, seem to struggle with predicting fuel dispersion and by inference, jet velocity. This shortcoming of the predictions suggests a need to improve Eulerian modeling of dense fuel jets.


2021 ◽  
Vol 23 ◽  
pp. 811-822
Author(s):  
Stanisław Ejdys

The main aim of the article is to present a theoretical model of a sustainable urban transport system and to indicate the need for changes in the approach to it. The issues of sustainable development and functioning of the municipal transport system in Olsztyn discussed in the article evoke vivid social and political interests of the city's inhabitants. This is mainly due to the impact of transport operation on quality of life, the correlation of its development with the economic development of the city, and the strong impact of transport on the natural environment. Today, it is already known that a coherent and modern transport system is an indispensable element of a competitive city. Connecting the city into a functional system, it presents it as a system of interdependencies between its elements.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5900-5900
Author(s):  
Esther Natalie Oliva ◽  
Sam Salek ◽  
Pushpendra Goswami ◽  
Tatyana Ionova

Abstract Background: Patient reported outcome (PRO) assessments, which include quality of life (QoL) and symptoms, have become increasingly important, aiding in identifying and informing patient needs. Patients with acute myeloid leukemia (AML) have poor clinical prognosis and outcomes. There is insufficient knowledge about the impact of disease and treatment on AML patients' lives. Methods: A multicentre study was performed in the UK to assess PROs in patients with haematological malignancy using a novel hematological malignancy (HM) specific PRO tool, HM-PRO, recently developed for use in daily clinical practice. The HM-PRO is a composite measure consisting of two scales: Part A-measuring the 'impact on patients' quality of life (QoL); and Part B-measuring the effect of 'signs and symptoms' experienced by the patients. Part A consists of domains: physical behaviour (PB), social well-being (SWB), emotional behaviour (EB) and eating and drinking habits (ED). All scales have linear scoring system ranging from 0 to 100, with higher scores representing greater impact on QoL and symptom burden. All data were analyzed by descriptive statistics. Parametric and non-parametric tests at a significance level of P<0.05 were applied as appropriate. Spearman's rank correlation coefficient and regression analysis were performed to investigate the associations between variables. We present the results in a subset of patients with AML. Results: Thirty-one patients, mean age 61 ± 16 years, 17 males, completed the assessment. Sixteen cases were > 60 years of age. Median time from diagnosis was 261 (IQR 131-790) days. Two cases were at diagnosis, 4 were resistant/refractory, 7 were stable, 15 were in remission (9 still receiving treatment, including stem cell transplantation), and 3 cases were long-term survivors. Ten cases had additional co-morbidities (5 patients in remission). HM-PRO showed good intraclass correlation and Cronbach's alpha > 0.80 in all dimensions (except for social well-being domain which comprised the item "I have problems with my sex life"). Median scores with interquartile ranges were: PB 36 (14-64); SWB 16 (0-33); EB 41 (14-59); ED 25 (25-75); symptom score 22 (17-33). Scale scores were independent of age, gender and comorbidities. PB score was associated with AML status, patients in remission fairing better (p=0.036). The PB item which was most affected was difficulty with physical activities in 77% of cases. EB was affected by 87% worried about future health, 80% worried about being a burden to others; 77% lamenting changes in sleeping pattern, 74% having difficulty concentrating, 67% feeling anxious, 60% worried about dying, 58% about treatment and 42% feeling distressed. ED was strongly associated with the impact of symptoms (p=0.001), with 63% affected by a change of taste so that most patients experienced a change in eating habits. Energy level was compromised (63% mildly, 33% severely) and 52% felt mildly and 38% severely tired. Difficulty with personal relationships present in 23% of cases correlated with distress (r=0.397, p=0.025), anxiety (r=0.471, p=008), lack of confidence (r=0.640, p<0.0001), worry about future health (p=0.357, p=0.042) and difficulty concentrating (r=0.452, p=0.009). Distress correlated with anxiety (r=0.560, p=0.001), fear of dying r=0.563, p=0.001) and worry about treatment (r=0.608, p<0.0001). Sleeping pattern disturbance was significantly correlated with most of the items within EB. Conclusions: AML has a strong impact on patients' lives. QoL is highly compromised, especially at a physical and emotional level, and seems to be independent of age, gender and comorbidities. Worry and anxiety are prevalent conditions. HM-PRO is a useful tool in clinical practice to identify relevant issues which should be considered during decision-making and addressed to individualize care of AML patients. Disclosures Oliva: La Jolla: Consultancy; Janssen: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Celgene: Consultancy, Other: Royalties, Speakers Bureau; Sanofi: Consultancy, Speakers Bureau. Ionova:Takeda: Research Funding; BMS: Research Funding.


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