scholarly journals Impacts on Brake Particle Emission Testing

Atmosphere ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1132 ◽  
Author(s):  
Sebastian Gramstat ◽  
Thilo Mertens ◽  
Robert Waninger ◽  
Dmytro Lugovyy
Keyword(s):  
Test Procedure ◽  
Particle Emission ◽  
Vehicle Speed ◽  
Particle Emissions ◽  
Emission Testing ◽  
Relevant Role ◽  
Brake Dynamometer ◽  
Brake Lining ◽  
The Impact

The presented article picks out brake particle emission testing as a central theme. Those emissions are part of the so-called non-exhaust emissions, which play an increasing role for particle emissions from transportation. The authors propose a laboratory test setup by using a brake dynamometer and a constant volume sampling approach to determine the emissions in regard to the particle number concentration. Several impacts were investigated while the same test cycle (novel worldwide harmonized light vehicles test procedure (novel-WLTP)) was applied. In a first item, the importance of the bedding process was investigated and it is shown that friction couples without bedding emit much more particles. Furthermore, the efforts for reaching a bedded friction state are discussed. Additionally, the impact of brake lining compositions is investigated and shows that NAO concepts own crucial advantages in terms of brake particle emissions. Another impact, the vehicle weight and inertia, respectively, shows how important lightweight measures and brake cooling improvements are. Finally, the role of the load profile is discussed, which shows the importance of driving parameters like vehicle speed and reservoir dynamics. The authors show that, under urban driving conditions, extreme low particle emissions are detected. Furthermore, it is explained that off-brake emissions can play a relevant role in regard to brake particle emissions.

scholarly journals Class Representatives and Students’ Behaviour: An Overview at the Post-Covid-19 Pandemic in the Perspective of the Community of Practice

2021 ◽  
Vol 4 (4) ◽  
pp. 137-143
Author(s):  
Ilane Frank Dias ◽  
Christane Bellucci
Keyword(s):  
Social Interactions ◽  
Community Of Practice ◽  
Learning Process ◽  
Online Classes ◽  
Virtual Classes ◽  
Relevant Role ◽  
Conceptual Paper ◽  
Multi Level ◽  
The Impact

Engagement of students and the learning process in the classroom has become one of the significant challenges that higher education (HE) institutions face in the era of the Covid-19 pandemic, with classes running in the virtual environment. One of the approaches that can be used to understand student behaviours and their social interactions is the community of practice (CoPs) as a construct that can be strategic to connect classes representatives, college's objectives and the student's behaviour. The class representatives can play a diverse role, from helping the tutors motivate the students on their learning process to acting as a central and essential communication channel between the students and the academic coordinators. Yet, little is known about the role of these students as a strategy to tackle such problems increased with online classes. This study investigates the impact of class representatives on students' behaviour in the sense of their engagement and learning in virtual classes context post the Covid-19 pandemic. This is a conceptual paper to bridge the mentioned theories, link work across disciplines, provide multi-level insights, and broaden the scope of thinking. The theoretical findings show that class representatives can play a relevant role by increasing engagement and facilitating the students' learning. The results can help HE institutions to develop policies and practices to be more competitive and move forward. This study advances the emergent research efforts to respond to the challenges arising from the Covid-19 pandemic.

Theoretical and experimental investigation of non-asbestos friction lining material applied in automotive drum brake

2019 ◽  
Vol 234 (6) ◽  
pp. 972-985
Author(s):  
Dinesh Subhash Shinde ◽  
KN Mistry ◽  
Mukesh Bulsara
Keyword(s):  
Coefficient Of Friction ◽  
Test Procedure ◽  
Frictional Resistance ◽  
Theoretical Models ◽  
Surface Phenomenon ◽  
Vehicle Speed ◽  
Lining Material ◽  
The Coefficient Of Friction ◽  
Brake Lining ◽  
Friction Lining

Automotive brakes are the important machine element which provides an artificial frictional resistance to control the speed of an automobile. In the present work, theoretical models for the coefficient of friction between brake drum and friction liner are generated and simulated using MATLAB Simulink. A test set up designed and manufactured according to the brake lining quality test procedure (SAE J661) is used to investigate tribological properties of a non-asbestos friction lining material having 11 different constituents, which is manufactured from one of the brake liner manufacturer. An experiment is designed using response surface methodology (RSM) with vehicle speed, braking force, and sliding distance as the input parameters, whereas coefficient of friction and wear as an output. It is found that vehicle speed is the most significant parameter among the three. Fade and recovery behavior of the friction lining material is also studied and it is found that the developed friction lining material satisfies the criteria specified in SAE J661. Scanning electron microscope (SEM) and energy dispersive spectoscopy (EDS) have revealed the significant surface phenomenon.

scholarly journals Predisposition to Change Is Linked to Job Satisfaction: Assessing the Mediation Roles of Workplace Relation Civility and Insight

2020 ◽  
Vol 17 (6) ◽  
pp. 2141 ◽  
Author(s):  
Alessio Gori ◽  
Eleonora Topino
Keyword(s):  
Job Satisfaction ◽  
Psychological Factors ◽  
Modern Society ◽  
Well Being ◽  
The Other ◽  
Relevant Role ◽  
The Impact ◽  
The Relationship ◽  
Positive Results

The globalization processes typical of liquid modern society require organizations to have high levels of flexibility, dynamism, and rapidity of change, testing the adaptability of workers with possible repercussions on well-being and productivity. Therefore, this study aimed to investigate the role of several psychological factors in favoring job satisfaction in a group of organizational workers (mean age = 46.24; SD = 9.99; 40.9% males and 59.1% females). Firstly, the impact of predisposition to change on job satisfaction through workplace relational civility (others with me) or insight orientation as independent mediating variables was analyzed. After that, this relationship was also studied by testing the effect that the simultaneous interaction of both mediators could have. Results show that workplace relational civility (others with me) significantly mediated the relationship between predisposition to change and job satisfaction, while no significance was found in the effect of insight when considered individually. However, the latter acquires greater relevance if placed in interaction with the other mediator, that is found to be the most proximal factor linking job satisfaction to the other more distal variables. Such findings might have a relevant role in strengthening preventive intervening, favoring positive results for greater well-being of both subjects and organizations.

scholarly journals Testing of Alternative Disc Brakes and Friction Materials Regarding Brake Wear Particle Emissions and Temperature Behavior

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 436
Author(s):  
David Hesse ◽  
Christopher Hamatschek ◽  
Klaus Augsburg ◽  
Thomas Weigelt ◽  
Alexander Prahst ◽  
...  
Keyword(s):  
Tungsten Carbide ◽  
Test Procedure ◽  
Wear Particle ◽  
Emission Factors ◽  
Particle Emission ◽  
Particle Emissions ◽  
Friction Materials ◽  
Disc Brakes ◽  
Brake Wear ◽  
Carbon Ceramic

In this study, different disc brakes and friction materials are evaluated with respect to particle emission output and characteristic features are derived. The measurements take place on an inertia dynamometer using a constant volume sampling system. Brake wear particle emission factors of different disc concepts in different sizes are determined and compared, using a grey cast iron disc, a tungsten carbide-coated disc and a carbon ceramic disc. The brakes were tested over a section (trip #10) novel test cycle developed from the database of the worldwide harmonized Light-Duty vehicles Test Procedure (WLTP). First, brake emission factors were determined along the bedding process using a series of trip-10 tests. The tests were performed starting from unconditioned pads, to characterize the evolution of emissions until their stabilization. In addition to number- and mass-related emission factors (PM2.5–PM10), the particle size distribution was determined. Another focus was the evaluation of temperature ranges and the associated challenges in the use of temperature readings in a potential regulation of brake wear particle emissions. The results illustrate the challenges associated with establishing a universal bedding procedure and using disc temperature measurements for the control of a representative braking procedure. Using tungsten carbide coated discs and carbon ceramic discs, emission reduction potentials of up to 70% (PM10) could be demonstrated along the WLTP brake cycle. The reduction potential is primarily the result of the high wear resistance of the disc, but is additionally influenced by the pad composition and the temperature in the friction contact area.

scholarly journals Through the Decreased Values Gap to Increased Organizational Effectiveness: The Mediating Role of Organizational Commitment

2018 ◽  
Vol 24 (2) ◽  
pp. 101-115 ◽  
Author(s):  
Ivan Malbaši´c ◽  
Marta Mas-Machuca ◽  
Frederic Marimon
Keyword(s):  
Organizational Commitment ◽  
Organizational Effectiveness ◽  
Structural Equation ◽  
Mediating Effect ◽  
Structured Interviews ◽  
Financial Reports ◽  
Mediating Role ◽  
Relevant Role ◽  
The Impact

The purpose of this article is to clarify whether congruence between espoused and attributed organizational values (CEAOV) in contemporary business circumstances is a necessity or just ‘nice to have’. Accordingly, two objectives are formulated: (a) to investigate whether CEAOV has a direct impact on organizational effectiveness and (b) to assess the mediating effect of organizational commitment between CEAOV and organizational effectiveness. The research was conducted within 15 Croatian companies ( n = 523). Data were collected through content analysis of the official websites of the companies, surveys of employees, semi-structured interviews with the members of top management and analysis of publicly available financial reports. A conceptual model is proposed regarding the mediating effect of organizational commitment on the impact of the espoused–attributed value fit on effectiveness. Structural equation modelling (SEM) was used for the analysis. The results show that CEAOV positively affects organizational effectiveness through the mediation of organizational commitment. The only path to attaining effectiveness is through commitment. No direct effect is found. Our research sheds light on the relevant role of authenticity, in the light of value congruence, in every organization. When employees and organizations live their values to the same degree, there is an impact on organizational commitment and hence on organizational effectiveness.

Role of rs10406069 in miR-5196 in hyperdiploid childhood acute lymphoblastic leukemia

Epigenomics ◽  
2020 ◽  
Vol 12 (22) ◽  
pp. 1949-1955
Author(s):  
Angela Gutierrez-Camino ◽  
Chantal Richer ◽  
Pascal St-Onge ◽  
Elixabet Lopez-Lopez ◽  
Ana Carbone Bañeres ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Target Genes ◽  
Lymphoblastic Leukemia ◽  
Childhood Acute Lymphoblastic Leukemia ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Mirna Genes ◽  
Relevant Role ◽  
The Impact

Aim: To determine the role of single nucleotide polymorphisms (SNPs) in noncoding RNAs in childhood acute lymphoblastic leukemia (ALL) subtypes. Materials & methods: We screened all SNPs in 130 pre-miRNA genes to assess their role in the susceptibility of the most common subtypes of ALL: hyperdiploid and ETV6-RUNX1. Results: In two independent cohorts, we found a significant association between rs10406069 in miR-5196 and the risk of developing hyperdiploid ALL. This observation could be explained by the impact of the SNP on miR-5196 expression and in turn, in its target genes. Indeed, rs10406069 was associated with expression changes in SMC1A, a gene involved in sister chromatin cohesion. Conclusion: rs10406069 in miR-5196 may have a relevant role in hyperdiploid ALL risk.

scholarly journals Particle Emissions and Disc Temperature Profiles from a Commercial Brake System Tested on a Dynamometer under Real-World Cycles

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 377
Author(s):  
Athanasios Mamakos ◽  
Katharina Kolbeck ◽  
Michael Arndt ◽  
Thomas Schröder ◽  
Matthias Bernhard
Keyword(s):  
Los Angeles ◽  
Real World ◽  
Test Procedure ◽  
Brake System ◽  
Short Version ◽  
Emission Rates ◽  
Particle Emissions ◽  
Radial Temperature ◽  
Potential Formation ◽  
Brake Dynamometer

The particle emissions from a commercial brake system utilizing copper-free pads have been characterized on a brake dynamometer under two real-world driving cycles. These included a novel cycle developed from analysis of the database of the World Harmonized Test Procedure (WLTP-Brake) and a short version of the Los Angeles City Traffic cycle (3h-LACT) developed in the framework of the European LowBraSys project. Disc temperature measurements using an array of embedded thermocouples revealed a large temporal and spatial non-uniformity with the radial temperature distribution depending also on the test procedure. Averaging over the duration of the cycle, it effectively reduced the influence of thermocouple positioning, allowing for more reliable quantification of the effectiveness of convective cooling. Particulate Matter (PM) emissions were similar for both cycles with PM2.5 averaging at 2.2 (±0.2) mg/km over the WLTP-Brake and 2.2 (±0.2) mg/km over the 3h-LACT, respectively. The corresponding PM10 emissions were 5.6 (±0.2) mg/km and 8.6 (±0.7) mg/km, respectively. The measurements revealed the formation of nanosized particles peaking at 10 nm, which were thermally stable at 350 °C under both cycles. Volatile nanoparticles were observed over the more demanding 3h-LACT cycle, with their emission rates decreasing with increasing the tunnel flow, suggesting nucleation of organic vapors released during braking as a potential formation process.

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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