Theoretical analysis of LC-refining – pressure screening systems in TMP

2019 ◽  
Vol 34 (1) ◽  
pp. 46-58 ◽  
Author(s):  
Jorge Enrique Rubiano Berna ◽  
Christer Sandberg ◽  
Mark Martinez ◽  
James Olson
Keyword(s):  
Fibre Length ◽  
Performance Curves ◽  
Average Fibre ◽  
Mechanical Pulps ◽  
Simulation Results ◽  
Save Energy ◽  
Relative Errors ◽  
The Impact ◽  
Screening Systems

Abstract LC refining of mechanical pulps has proven to save energy in the production of TMP pulps. However, the specific role of LC refining as part of a TMP system has not been thoroughly studied since it is difficult to conceive any particular system at industrial-scales and impractical at pilot-scales. In this study, pressure screening and LC refining models that describe fibre length distributions, together with correlations to predict refining power were used to model three basic refining systems. From the simulation results, the impact of important variables such as reject ratio, refiner gap and refining net-power was studied. Performance curves of length-weighed average fibre length were generated from simulation results and were used to assess each system behaviour and also to make comparisons between systems. Data from an industrial scale TMP mill sub-system was gathered and compared to simulation results showing relative errors between 0–18 % on the predicted variables.

scholarly journals The Potential Role of Stakeholders in the Energy Efficiency of Higher Education Institutions

2020 ◽  
Vol 12 (21) ◽  
pp. 8908
Author(s):  
Rubén Garrido-Yserte ◽  
María-Teresa Gallo-Rivera
Keyword(s):  
Higher Education ◽  
Energy Efficiency ◽  
Energy Consumption ◽  
Higher Education Institutions ◽  
Action Plan ◽  
Research Approach ◽  
Save Energy ◽  
The University ◽  
The Impact

Higher education institutions (HEIs) have a huge potential to save energy as they are significantly more energy-intensive in comparison with commercial offices and manufacturing premises. This paper provides an overview of the chief actions of sustainability and energy efficiency addressed by the University of Alcalá (Madrid, Spain). The policies implemented have shifted the University of Alcalá (UAH) to become the top-ranking university in Spain and one of the leading universities internationally on environmentally sustainable practices. The paper highlights two key elements. First, the actions adopted by the managerial teams, and second, the potential of public–private collaboration when considering different stakeholders. A descriptive study is developed through document analysis. The results show that energy consumption per user and energy consumption per area first fall and are then maintained, thereby contributing to meeting the objectives of the Spanish Government’s Action Plan for Energy Saving and Efficiency (2011–2020). Because of the research approach, the results cannot be generalized. However, the paper fulfils an identified need to study the impact of HEIs and their stakeholders on sustainable development through initiatives in saving energy on their campuses and highlights the role of HEIs as test laboratories for the introduction of innovations in this field (monitoring, sensing, and reporting, among others).

Studying the Impact of Return Current Path on the EM Simulation of High-speed Package Designs

2011 ◽  
Vol 2011 (1) ◽  
pp. 000061-000068
Author(s):  
Darryl Kostka ◽  
Antonio Ciccomancini Scogna
Keyword(s):  
High Speed ◽  
Ground Plane ◽  
Three Dimensional ◽  
Simulation Models ◽  
Current Path ◽  
Cavity Resonances ◽  
Simulation Results ◽  
The Impact ◽  
Simulation Time

Three-dimensional electromagnetic simulation models are often simplified in order to reduce the simulation time and memory requirements without sacrificing the accuracy of the results. A commonly adopted methodology in the simulation of electronic package designs is to truncate the size of the package model leaving only a few important features surrounding the nets of interest. In this paper we demonstrate that this simplification can have a significant impact of the simulation results if it is not performed carefully and it can introduce spurious/non physical resonances. The interaction between cavities and signals is first studied using a simple coupled differential via test structure. It is demonstrated that the return currents generated by these vias excite cavity resonances in power-ground plane pairs causing them to behave as parallel-plate waveguides. The role of interplane shorting vias in suppressing cavity resonances is then investigated and the impact of boundary conditions on the simulation results of package models is also shown and discussed. Finally, a realistic complex multilayer package model is analyzed and it is demonstrate that through proper truncation of the geometry, accurate results can be obtained.

scholarly journals System Dynamics Modelling of Remanufacturing and Recycling Mode Based on Closed-Loop Across-Chain Competition

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Shidi Miao ◽  
Deyun Chen ◽  
Tengfei Wang
Keyword(s):  
Supply Chain ◽  
Closed Loop ◽  
Third Party ◽  
Total Revenue ◽  
Proposed Model ◽  
Dynamics Modelling ◽  
Simulation Results ◽  
The Impact

To face the reality of resources exhaustion, the significance of recycling and remanufacturing in the closed-loop chain has become quite evident. This paper constructs a competitive recycling and remanufacturing model of the closed-loop supply chain through a case study of Midea Corp. and Gree Corp. and explores the impact of two recycling modes on total revenue of the supply chain and market share. The simulation results show that the total revenue of the supply chain will benefit from the increasing coverage points by the third party and the increasing environmental awareness of certain regions. The retailers show more enthusiasm of recycling through certain amendment of the contract between manufacturers and retailers. The time of payment could be shortened in closed loop. Moreover, the improvement of recycling mechanism of the retailers can enlarge the share of supply chain market. Guiding role of the proposed model and the simulation results played in establishing a better supply chain mode is presented.

scholarly journals Investigations into the Role of Friction for Rigid Penetration into Concrete-Like Material Targets

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4733
Author(s):  
Ningjing Jiang ◽  
Shufan Wu ◽  
Yile Hu ◽  
Zhongcheng Mu ◽  
Xiaofeng Wu ◽  
...  
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Phase Behavior ◽  
Impact Dynamics ◽  
Two Phase ◽  
Penetration Process ◽  
Simulation Results ◽  
Penetration Behavior ◽  
The Impact

Currently, it appears that there is a lack of understanding related to the role of SSF, in the two-phase behavior of the deceleration history, which is an issue discussed recently in the impact dynamics field. This paper analytically and numerically focuses on the effect of SSF on the projectile deceleration characteristic of concrete-like targets. Firstly, the penetration process according to the two-phase feature of the projectile deceleration is revised, where analytical results indicate that the SSF has a phased feature corresponding to the two-phase behavior of the deceleration history. Furthermore, a series of numerical simulations are conducted to understand the role of SSF more clearly. Simulation results show a similar conclusion to the analyses of the two-phase penetration process; at the range below a certain critical striking velocity, adding friction can reproduce the experimental data; when exceeding the critical striking velocity, the simulated results without considering friction are closest to the experimental data. Hence, it could be gained that the role exchange between the SSF and the dynamic term contributes to the two-phase penetration behavior for concrete-like materials. This indicates that the sensitivity of SSF to the penetration process is one of the factors driving the two-phase feature.

Average fibre length as a measure of the amount of long fibres in mechanical pulps – ranking of pulps may shift

2018 ◽  
Vol 33 (3) ◽  
pp. 468-481
Author(s):  
Olof Ferritsius ◽  
Rita Ferritsius ◽  
Mats Rundlöf
Keyword(s):  
Average Length ◽  
Fibre Length ◽  
Real Life ◽  
Raw Material ◽  
Relevant Parameter ◽  
Specific Energy Input ◽  
Arithmetic Average ◽  
Average Fibre ◽  
Mechanical Pulps ◽  
Individual Particles

Abstract The purpose of this study was to investigate the applicability of different ways of calculating the average fibre length based on length measurements of individual particles of mechanical pulps. We have found that the commonly used average length-weighted fibre length, which is based on the assumption that coarseness is constant for all particles, as well as the arithmetic average, may lead to erroneous conclusions in real life as well as in simulations when used as a measure of the amount of long fibres. The average length-length-weighted fibre length or a weighting close to that, which to a larger extent suppresses the influence of shorter particles, is a relevant parameter of the “length” factor, i. e. amount of long fibres. Our findings are based on three studies: refining of different assortments of wood raw material in a mill; data from LC refining in mill of TMP, including Bauer McNett fractionation; mixing of pulps with different fibre length distributions. If the acceptable average fibre length for different products can be lowered, the possibility of reducing the specific energy input in refining will increase. Therefore, we need a reliable and appropriate way to assess the “length” factor.

Studying the Impact of Return Current Path on the EM Simulation of High-Speed Package and Board Designs

2012 ◽  
Vol 9 (2) ◽  
pp. 52-64
Author(s):  
Darryl Kostka ◽  
Antonio Ciccomancini Scogna
Keyword(s):  
High Speed ◽  
Ground Plane ◽  
Three Dimensional ◽  
Simulation Models ◽  
Combined Model ◽  
Current Path ◽  
Cavity Resonances ◽  
Simulation Results ◽  
The Impact

Three-dimensional electromagnetic simulation models are often simplified in order to reduce simulation time and memory requirements without sacrificing the accuracy of the results. A commonly adopted methodology in the simulation of complex electronic package and board designs is to truncate the size of the model, leaving only a few important features surrounding the nets of interest. In this paper we demonstrate that this simplification can have a significant impact on the simulation results if it is not performed carefully, and it can introduce spurious nonphysical resonances. The interaction between cavities and signals is first studied using a simple coupled differential via test structure. It is demonstrated that the return currents generated by these vias excite cavity resonances in power-ground plane pairs causing them to behave as parallel-plate waveguides. The role of interplane shorting vias in suppressing cavity resonances is then investigated and the impact of boundary conditions on the simulation results of package models is also shown and discussed. The focus is then shifted to PCB/package cosimulation and the impact of different truncation schemes is discussed through the simulation of test structures of varying complexity. A simulation methodology is then proposed and is verified for a combined model of a realistic complex multilayer package and board and it is demonstrated that accurate results can be obtained through proper truncation of the geometry.

Intergroup Threat and Outgroup Attitudes

2013 ◽  
Vol 44 (5) ◽  
pp. 311-319 ◽  
Author(s):  
Marco Brambilla ◽  
David A. Butz
Keyword(s):  
Gay Men ◽  
Social Group ◽  
Welfare Recipients ◽  
Intergroup Attitudes ◽  
Social Policies ◽  
Intergroup Threat ◽  
Economic Threat ◽  
The Impact ◽  
General Climate

Two studies examined the impact of macrolevel symbolic threat on intergroup attitudes. In Study 1 (N = 71), participants exposed to a macrosymbolic threat (vs. nonsymbolic threat and neutral topic) reported less support toward social policies concerning gay men, an outgroup whose stereotypes implies a threat to values, but not toward welfare recipients, a social group whose stereotypes do not imply a threat to values. Study 2 (N = 78) showed that, whereas macrolevel symbolic threat led to less favorable attitudes toward gay men, macroeconomic threat led to less favorable attitudes toward Asians, an outgroup whose stereotypes imply an economic threat. These findings are discussed in terms of their implications for understanding the role of a general climate of threat in shaping intergroup attitudes.

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