scholarly journals Sooting tendencies of diesel fuel component mixtures follow a linear mixing rule

2022 ◽  
Author(s):  
Zhanhong Xiang ◽  
Karnsiree Chen ◽  
Charles McEnally ◽  
Lisa Pfefferle
Keyword(s):  
Linear Combination ◽  
Alternative Fuels ◽  
Soot Formation ◽  
Mass Density ◽  
Weighted Average ◽  
Fuel Mixture ◽  
Mixing Rule ◽  
Fuel Component ◽  
Study Results ◽  
The Individual

With the growing importance of climate change, soot emissions from engines have been receiving increasing attention since black carbon is the second largest source of global warming. A sooting tendency can be used to quantify the extent of soot formation in a combustion device for a given fuel molecule, and therefore to quantify the soot reduction benefits of alternative fuels. However real fuels are complex mixtures of multiple components. In this work, we have used experimental methods to investigate how the sooting tendency of a blended fuel mixture is related to the sooting tendencies of the individual components. A test matrix was formulated that includes sixteen mixtures of six components that are representative of the main categories of hydrocarbons in diesel (eicosane (ECO) for alkanes, isocetane (ICE) for isoalkanes, butylcyclohexane (BCH) for cycloalkanes, 1-methylnaphthalene (1MN) for aromatics, tetralin for naphthoaromatics, and methyl-decanoate (MDC) for oxygenates). Most of the mixtures contain three to five components. The sooting tendency of each mixture was characterized by yield sooting index (YSI), which is based on the soot yield when a methane/air nonpremixed flame is doped with 1000 ppm of the test fuel. The YSIs were measured experimentally. The results show that the blending behavior is linear, i.e., the YSI of the mixtures is the mole-fraction-weighted average of the component YSIs. Experimental results have shown that the sooting tendency of a fuel mixture can be accurately estimated as the linear combination of the individual components. In addition, mass density of the mixtures is also measured, and a linear blending rule is applied to test whether mixing rules exist for mass density of diesel mixtures in this study. Results also have shown that the mixing rule tested in this study is valid and mass density of a mixture can be accurately estimated from the linear combination of the individual components.

scholarly journals THE COMPARISON OF TREE QUALITIES

1965 ◽  
Vol 41 (2) ◽  
pp. 215-221
Author(s):  
P. L. Northcott
Keyword(s):  
Computer Program ◽  
Linear Combination ◽  
Digital Computer ◽  
Weighted Average ◽  
Statistical Procedure ◽  
Weighted Sum ◽  
Average Quality ◽  
The Individual

The need to compare individuals is discussed briefly. It is suggested that the composite quality of an individual is best defined as the weighted sum of a number of measurable characteristics of the individual. A statistical procedure for comparison of weighted average quality is derived from application of the principle of the linear combination of variables. A digital computer program is available.

scholarly journals Symptom Cluster-Matching Antidepressant Treatment: A Case Series Pilot Study

2021 ◽  
Vol 14 (6) ◽  
pp. 526
Author(s):  
Sławomir Murawiec ◽  
Marek Krzystanek
Keyword(s):  
Depressive Symptoms ◽  
Pilot Study ◽  
Antidepressant Treatment ◽  
Case Series ◽  
Symptom Cluster ◽  
Study Results ◽  
Cluster Matching ◽  
The Individual ◽  
Meta Analyses ◽  
Effectiveness Studies

Despite treating depression with antidepressants, their effectiveness is often insufficient. Comparative effectiveness studies and meta-analyses show the effectiveness of antidepressants; however, they do not provide clear indications as to the choice of a specific antidepressant. The rational choice of antidepressants may be based on matching their mechanisms of action to the symptomatic profiles of depression, reflecting the heterogeneity of symptoms in different patients. The authors presented a series of cases of patients diagnosed with depression in whom at least one previous antidepressant treatment was shown to be ineffective before drug targeted symptom cluster-matching treatment (SCMT). The presented pilot study shows for the first time the effectiveness of SCMT in the different clusters of depressive symptoms. All the described patients obtained recovery from depressive symptoms after introducing drug-targeted SCMT. Once validated in clinical trials, SCMT might become an effective and rational method of selecting an antidepressant according to the individual profile of depressive symptoms, the mechanism of their formation, and the mechanism of drug action. Although the study results are preliminary, SCMT can be a way to personalize treatment, increasing the likelihood of improvement even in patients who meet criteria for treatment-resistant depression.

scholarly journals A Novel Multi-Criteria Group Decision-Making Approach Based on Bonferroni and Heronian Mean Operators under Hesitant 2-Tuple Linguistic Environment

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1489
Author(s):  
Shahzad Faizi ◽  
Wojciech Sałabun ◽  
Nisbha Shaheen ◽  
Atiq ur Rehman ◽  
Jarosław Wątróbski
Keyword(s):  
Decision Making ◽  
Group Decision Making ◽  
Group Decision ◽  
Weighted Average ◽  
Aggregation Operators ◽  
Bonferroni Mean ◽  
Operational Laws ◽  
Geometric Bonferroni Mean ◽  
The Individual ◽  
Heronian Mean

Ambiguous and uncertain facts can be handled using a hesitant 2-tuple linguistic set (H2TLS), an important expansion of the 2-tuple linguistic set. The vagueness and uncertainty of data can be grabbed by using aggregation operators. Therefore, aggregation operators play an important role in computational processes to merge the information provided by decision makers (DMs). Furthermore, the aggregation operator is a potential mechanism for merging multisource data which is synonymous with cooperative preference. The aggregation operators need to be studied and analyzed from various perspectives to represent complex choice situations more readily and capture the diverse experiences of DMs. In this manuscript, we propose some valuable operational laws for H2TLS. These new operational laws work through the individual aggregation of linguistic words and the collection of translation parameters. We introduced a hesitant 2-tuple linguistic weighted average (H2TLWA) operator to solve multi-criteria group decision-making (MCGDM) problems. We also define hesitant 2-tuple linguistic Bonferroni mean (H2TLBM) operator, hesitant 2-tuple linguistic geometric Bonferroni mean (H2TLGBM) operator, hesitant 2-tuple linguistic Heronian mean (H2TLHM) operator, and a hesitant 2-tuple linguistic geometric Heronian mean (H2TLGHM) operator based on the novel operational laws proposed in this paper. We define the aggregation operators for addition, subtraction, multiplication, division, scalar multiplication, power and complement with their respective properties. An application example and comparison analysis were examined to show the usefulness and practicality of the work.

Do information technology (IT) capabilities affect hotel competitiveness?

2020 ◽  
Vol 11 (3) ◽  
pp. 447-460
Author(s):  
Nan Hua
Keyword(s):  
Design Methodology ◽  
Financial Data ◽  
Content Type ◽  
It Systems ◽  
Study Results ◽  
It Capabilities ◽  
The Usa ◽  
Lagged Effects ◽  
The Individual ◽  
Direct Measures

Purpose This paper aims to examine the impacts of IT capabilities on hotel competitiveness. Design/methodology/approach This study adapts and extends Hua et al. (2015) and O’Neill et al. (2008) by incorporating the specific measures of IT expenditures as proxies for the relevant IT capabilities to explore the impacts of IT capabilities on hotel competitiveness. Findings This study finds that expenditures on IT Labor, IT Systems and IT Websites exert different impacts on hotel competitiveness. In addition, IT capabilities exert both contemporary and lagged effects on hotel competitiveness. Originality/value This study is the first that uses financial data to capture direct measures of individual IT capabilities and tests the individual impacts of IT capabilities on hotel competitiveness from both contemporaneous and lagged perspectives. It uses a large same store sample of hotels in the USA from 2011 to 2017; as a result, the study results can be reasonably representative of the hotel population in the USA.

Three-compartment model: critical evaluation based on neutron activation analysis

2004 ◽  
Vol 287 (5) ◽  
pp. E962-E969 ◽  
Author(s):  
Analiza M. Silva ◽  
Wei Shen ◽  
ZiMian Wang ◽  
John F. Aloia ◽  
Miriam E. Nelson ◽  
...  
Keyword(s):  
Neutron Activation ◽  
Mass Density ◽  
Critical Evaluation ◽  
Morbidly Obese ◽  
Body Volume ◽  
Body Protein ◽  
Study Results ◽  
Total Body ◽  
3C Model

There is renewed interest in Siri's classic three-compartment (3C) body composition model, requiring body volume (BV) and total body water (TBW) estimates, because dual-energy X-ray absorptiometry (DEXA) and in vivo neutron activation (IVNA) systems cannot accommodate subjects with severe obesity. However, the 3C model assumption of a constant ratio (α) of mineral (M) to total body protein (TBPro) and related residual mass density (DRES) based on cadaver analyses might not be valid across groups differing in sex, race, age, and weight. The aim of this study was to derive new 3C model coefficients in vivo and to compare these estimates to those derived by Siri. Healthy adults ( n = 323) were evaluated with IVNA and DEXA and the measured components used to derive α and DRES. For all subjects combined, values of α and DRES (means ± SD, 0.351 ± 0.043; 1.565 ± 0.023 kg/l) were similar to Siri's proposed values of 0.35 and 1.565 kg/l, respectively. However, α and DRES varied significantly as a function of sex, race, weight, and age. Expected errors in percent body fat arising by application of Siri's model were illustrated in a second group of 264 adults, including some whose size exceeded DEXA limits but whose BV and TBW had been measured by hydrodensitometry and 2H2O dilution, respectively. Extrapolation of predictions by newly developed models to very high weights allows percent fat error estimation when Siri's model is applied in morbidly obese subjects. The present study results provide a critical evaluation of potential errors in the classic 3C model and present new formulas for use in selected populations.

scholarly journals Flexibility Reserve of Self-Consumption Optimized Energy Systems in the Household Sector

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3017
Author(s):  
Elias Dörre ◽  
Sebastian Pfaffel ◽  
Alexander Dreher ◽  
Pedro Girón ◽  
Svenja Heising ◽  
...  
Keyword(s):  
Unit Commitment ◽  
Programming Model ◽  
Weighted Average ◽  
Heat Pumps ◽  
Mixed Integer ◽  
Single Family ◽  
Unit Commitment Problem ◽  
Household Sector ◽  
The Future ◽  
The Individual

Energy generation and consumption in the power grid must be balanced at every single moment. Within the synchronous area of continental Europe, flexible generators and loads can provide Frequency Containment Reserve and Frequency Restoration Reserve marketed through the balancing markets. The Transmission System Operators use these flexibilities to maintain or restore the grid frequency when there are deviations. This paper shows the future flexibility potential of Germany’s household sector, in particular for single-family and twin homes in 2025 and 2030 with the assumption that households primarily optimize their self-consumption. The primary focus is directed to the flexibility potential of Electric Vehicles, Heat Pumps, Photovoltaics and Battery Storage Systems. A total of 10 different household system configurations were considered and combined in a weighted average based on the scenario framework of the German Grid Development Plan. The household generation, consumption and storage units were simulated in a mixed-integer linear programming model to create the time series for the self-consumption optimized households. This solved the unit commitment problem for each of the decentralized households in their individual configurations. Finally, the individual household flexibilities were evaluated and then aggregated to a Germany-wide flexibility profile for single-family and twin homes. The results indicate that the household sector can contribute significantly to system stabilization with an average potential of 30 negative and 3 positive flexibility in 2025. In 2030, the corresponding flexibilities potentially increase to 90 and 30 , respectively. This underlines that considerable flexibility reserves could be provided by single-family and twin homes in the future.

Influence of conspiracy theories, misinformation and knowledge on public adoption of Nigerian government’s COVID-19 containment policies

2021 ◽  
Vol 13 (2) ◽  
pp. 269-285 ◽  
Author(s):  
Ifeoma Theresa Amobi ◽  
Lambe Kayode Mustapha ◽  
Lilian Adaora Udodi ◽  
Oluwakemi Akinuliola-Aweda ◽  
Mogbonjubade Esther Adesulure ◽  
...  
Keyword(s):  
Group Discussion ◽  
Opinion Leaders ◽  
Safety Measures ◽  
Conspiracy Theories ◽  
The Social ◽  
Study Results ◽  
Media Space ◽  
Analyse Data ◽  
The Individual ◽  
Collective Influence

This study examined the individual and collective influence of conspiracy theories, misinformation and knowledge revolving around COVID-19, on public adoption of the Nigerian government’s containment policies. The study adopted the Survey, and Focus Group Discussion (FGD) methods. For the survey, a sample of 466 respondents were drawn from Facebook, Instagram, Messenger and WhatsApp, while 24 participants were selected for the FGD. The Statistical Package for Social Sciences (SPSS) and thematic approach were used to analyse data generated from the study. Results revealed a COVID-19 conspiratorial thinking among survey respondents and FGD participants, who were also familiar with the orgy of unbridled dissemination of misinformation and conspiracy theories in the social media space. Majority of respondents were knowledgeable about government’s COVID-19 containment policies and were practicing the recommended safety measures. Their decision was influenced by trust in opinion leaders, especially family members and medical experts.

Multiple fuel injection strategy for premixed charge compression ignition combustion engine using biodiesel blends

2022 ◽  
pp. 146808742110667
Author(s):  
Akhilendra Pratap Singh ◽  
Ashutosh Jena ◽  
Avinash Kumar Agarwal
Keyword(s):  
Alternative Fuels ◽  
Fuel Injection ◽  
Engine Performance ◽  
Pilot Injection ◽  
Compression Ignition ◽  
Combustion Control ◽  
Combustion Mode ◽  
Biodiesel Blends ◽  
Injection Parameters ◽  
Study Results

In the last decade, advanced combustion techniques of the low-temperature combustion (LTC) family have attracted researchers because of their excellent emission characteristics; however, combustion control remains the main issue for the LTC modes. The objective of this study was to explore premixed charge compression ignition (PCCI) combustion mode using a double pilot injection (DPI; pilot-pilot-main) strategy to achieve superior combustion control and to tackle the soot-oxides of nitrogen (NOx) trade-off. Experiments were carried out in a single-cylinder research engine fueled with 20% v/v biodiesel blended with mineral diesel (B20) and 40% v/v biodiesel blended with mineral diesel (B40) vis-à-vis baseline mineral diesel. Engine speed and rate of fuel-mass injected were maintained constant at 1500 rpm and 0.6 kg/h mineral diesel equivalent, respectively. Pilot injection timings (at 45° and 35° before top dead center (bTDC)) and fuel quantities were fixed, while three fuel injection pressures (FIPs) and four different start of the main injection (SoMI) timings were investigated in this study. Results showed that multiple pilot injections resulted in a stable PCCI combustion mode, making it suitable for higher engine loads. For all test fuels, advancing SoMI timings led to relatively lesser knocking; however, engine performance characteristics degraded at advanced SoMI timings. B40 exhibited relatively superior engine performance among different test fuels at lower FIP; however, the difference in engine performance was insignificant at higher FIPs. Fuel injection parameters showed a significant effect on emissions, especially on the NOx and particulates. Advancing SoMI timing resulted in 20%–50% lower particulates emissions with a slight NOx increase; however, the differences in emissions at different SoMI timings reduced at higher FIPs. Somewhat higher particulates from biodiesel blends were a critical observation of this study, which was more dominant at advanced SoMI timings. Qualitative correlation between NOx-total particulate mass (TPM) was another critical analysis, which exhibited the relative importance of different fuel injection parameters for other alternative fuels. Overall, B20 at 700 bar FIP and 20° SoMI timing emerged as the most promising proposition with some penalty in CO emission.

scholarly journals The Effect of Training Results Perception on Individual Work Performance of Employee Moderated by Intrinsic and Extrinsic Motivation

2021 ◽  
Vol 21 (3) ◽  
pp. 208
Author(s):  
Hidayah Turachma ◽  
Hidajat Hendarsjah
Keyword(s):  
Quantitative Research ◽  
Work Performance ◽  
Extrinsic Motivation ◽  
Hierarchical Regression ◽  
Intrinsic And Extrinsic Motivation ◽  
Individual Work ◽  
Study Results ◽  
The Individual ◽  
Executive Position

This study aims at examining the effect of training results perceptions on individual work performance of employee, and intrinsic and extrinsic motivation serving as moderation strengthening that effect. T his study was quantitative research selecting 453 samples out of 1.311 population from PT KAI’s employees in which they are executive officer. The data collection was done using a close questionnaire with Likert scale 1-5. All valid and reliable instruments were assessed through Factor Analysis and Cronbach's Alpha Analysis. Hypothesis testing is carried out using Hierarchical Regression Analysis by including the Multicollinearity test as a prerequisite for analysis. The study results showed that training result perceptions and extrinsic motivation simultaneously or partially have a positive and significant effect on individual work performance of employee, but intrinsic motivation have no significant effect. Intrinsic or extrinsic motivation does not moderate or strengthen the relationship between training result perceptions and individual work performance of employee. The three independent variables are not related to each other. PT KAI’s employees, especially those in executive position, are more oriented towards extrinsic results than intrinsic ones. The implication for PT KAI is that to improve the individual work performance of its employees, the organization can focus on improving training, external motivation or both. It depends on the vision, long-term goals, and resources of PT KAI.

scholarly journals A consensus-based global optimization method for high dimensional machine learning problems

2020 ◽  
Author(s):  
Jose Carrillo ◽  
Shi Jin ◽  
Lei Li ◽  
Yuhua Zhu
Keyword(s):  
Optimization Problems ◽  
Computational Cost ◽  
Weighted Average ◽  
Planck Equation ◽  
Optimization Method ◽  
Learning Problems ◽  
High Dimensional ◽  
Nonconvex Functions ◽  
The Individual ◽  
Parameter Constraints

We improve recently introduced consensus-based optimization method, proposed in [R. Pinnau, C. Totzeck, O. Tse and S. Martin, Math. Models Methods Appl. Sci., 27(01):183{204, 2017], which is a gradient-free optimization method for general nonconvex functions. We rst replace the isotropic geometric Brownian motion by the component-wise one, thus removing the dimensionality dependence of the drift rate, making the method more competitive for high dimensional optimization problems. Secondly, we utilize the random mini-batch ideas to reduce the computational cost of calculating the weighted average which the individual particles tend to relax toward. For its mean- eld limit{a nonlinear Fokker-Planck equation{we prove, in both time continuous and semi-discrete settings, that the convergence of the method, which is exponential in time, is guaranteed with parameter constraints independent of the dimensionality. We also conduct numerical tests to high dimensional problems to check the success rate of the method.

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