Influence of Working Parameters and Primary Breakup Conditions on the Quality of Twin-Fluid Atomizers Spray Quality

2016 ◽  
Vol 821 ◽  
pp. 91-96
Author(s):  
Marek Mlkvik ◽  
Matous Zaremba ◽  
Philipp Stähle ◽  
Heike P. Schuchmann ◽  
Volker Gaukel ◽  
...  

In this study we investigated four twin-fluid atomizers with different internal mixing mechanisms: Y-jet, outside in gas (OIG), outside in liquid (OIL) and CFT atomizers. The main goal was to relate the measured droplet sizes, characterized by the Sauter mean diameter (ID32), to the corresponding working regimes of atomizers and primary breakup conditions characterized by the criterion Dmax, estimated from critical Weber number of the primary breakup. For the OIL, OIG and CFT atomizers, the common relation of the primary breakup characteristics and normalized droplet sizes (ID32/Dmax) was found. As the Y-jet atomizer showed a different trend, which was related to the considerably lower Weber numbers of the near-nozzle flow, a change in the normalization criterion was necessary to obtain similar results as for other tested atomizers. The main benefit of presented results is the potential to predict spray droplet sizes entirely from primary breakup characteristics regardless of the atomizer’s design or the atomized liquid.

Author(s):  
S. Gepperth ◽  
R. Koch ◽  
H.-J. Bauer

As the dominating parameters influencing the Sauter mean diameter of the spray produced by a prefilming airblast atomizer, the air velocity, liquid surface tension and atomizing edge thickness could be identified. Correlations for the prediction of the droplet sizes produced by prefilming airblast atomizers are compared to droplet sizes measured close to the atomizing edge. The measurements were performed using three geometrical variants of a planar atomizer over a wide range of operating conditions. The diagnostics are based on a particle and ligament tracking technique, that enables simultaneous measurement of the liquid blobs and ligaments formed at the atomizing edge and the droplets in the primary breakup region of the atomizer. The comparison between measured and calculated droplet diameter indicates, that most of the correlations are capable of reproducing the correct tendency. However, since the measurement data of most correlations were collected in a region where secondary atomization effects can obscure the initial droplet sizes in the primary breakup region, the droplet sizes are generally predicted too small.


2020 ◽  
Vol 26 (11) ◽  
pp. 2567-2593
Author(s):  
M.V. Pomazanov

Subject. The study addresses the improvement of risk management efficiency and the quality of lending decisions made by banks. Objectives. The aim is to present the bank management with a fair algorithm for risk management motivation on the one hand, and the credit management (business) on the other hand. Within the framework of the common goal to maximize risk-adjusted income from loans, this algorithm will provide guidelines for ‘risk management’ and ‘business’ functions on how to improve individual and overall efficiency. Methods. The study employs the discriminant analysis, type I and II errors, Lorentz curve modeling, statistical analysis, economic modeling. Results. The paper offers a mechanism for assessing the quality of risk management decisions as opposed to (or in support of) decisions of the lending business when approving transactions. The mechanism rests on the approach of stating type I and II errors and the corresponding classical metric of the Gini coefficient. On the ‘business’ side, the mechanism monitors the improvement or deterioration of the indicator of changes in losses in comparison with the market average. Conclusions. The study substantiates the stimulating ‘rules of the game’ between the ‘business’ and ‘risk management’ to improve the efficiency of the entire business, to optimize interactions within the framework of internal competition. It presents mathematical tools to calculate corresponding indicators of the efficiency of internally competing entities.


Children ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 535
Author(s):  
Seung Kim ◽  
Mireu Park ◽  
Eunyoung Kim ◽  
Ga Eun Kim ◽  
Jae Hwa Jung ◽  
...  

We share our experience on the implementation of a multidisciplinary aerodigestive program comprising an aerodigestive team (ADT) so as to evaluate its feasibility. We performed a retrospective chart review of the patients discussed at the monthly ADT meetings and analyzed the data. A total of 98 children were referred to the ADT during the study period. The number of cases increased steadily from 3.5 cases per month in 2019 to 8.5 cases per month in 2020. The median age of patients was 34.5 months, and 55% were male. Among the chronic comorbidities, neurologic disease was the most common (85%), followed by respiratory (36%) and cardiac (13%) disorders. The common reasons for consultation were suspected aspiration (56%), respiratory difficulty (44%), drooling/stertor (30%), regurgitation/vomiting (18%), and feeding/swallowing difficulty (17%). Following discussions, 58 patients received active interventions, including fundoplication, gastrostomy, laryngomicrosurgery, tracheostomy, and primary dilatation of the airway. According to the questionnaire of the caregiver, the majority agreed that the main symptoms and quality of life of patients had improved (88%), reducing the burden on caregivers (77%). Aerodigestive programs may provide comprehensive and multidisciplinary management for children with complex airway and digestive tract disorders.


2021 ◽  
Vol 13 (13) ◽  
pp. 7300
Author(s):  
Anna Maria Colavitti ◽  
Alessio Floris ◽  
Sergio Serra

In Italy, after the introduction of the Code of Cultural Heritage and Landscape in 2004, the Regional Landscape Plan (RLP) has acquired a coordination role in the urban planning system, for the implementation of policies for landscape protection and valorisation. The case study of the RLP of Sardinia is a paradigmatic application to the coastal area of the island, which is considered most vulnerable and subject to settlement pressure. The objectives of preservation and valorisation of the territorial resources should be transferred into local planning instruments by adopting strategies aimed at the preservation of the consolidated urban fabric, at the requalification and completion of the existing built-up areas according to the principles of land take limitation and increase in urban quality. The paper investigates the state of implementation and the level of integration of landscape contents in the local plans that have been adapted to the RLP, using a qualitative comparative method. In addition, the results of the plan coherence checks, elaborated by the regional monitoring bodies after the adaptation process, have been analysed to identify the common criticalities and weaknesses. The results highlight the lack of effectiveness of the RLP, after more than a decade since its approval, considering the limited number of adequate local plans and the poor quality of their analytical and regulative contents in terms of landscape protection and valorisation. Conclusions suggest some possible ways to revise the RLP, focusing on the participation of local communities and the development of a new landscape culture.


Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 557
Author(s):  
Irene Mariñas-Collado ◽  
Elisa Frutos Bernal ◽  
Maria Teresa Santos Martin ◽  
Angel Martín del Rey ◽  
Roberto Casado Vara ◽  
...  

The knowledge of the topological structure and the automatic fare collection systems in urban public transport produce many data that need to be adequately analyzed, processed and presented. These data provide a powerful tool to improve the quality of transport services and plan ahead. This paper aims at studying, from a mathematical and statistical point of view, the Barcelona metro network; specifically: (1) the structural and robustness characteristics of the transportation network are computed and analyzed considering the complex network analysis; and (2) the common characteristics of the different subway stations of Barcelona, based on the passenger hourly entries, are identified through hierarchical clustering analysis. These results will be of great help in planning and restructuring transport to cope with the new social conditions, after the pandemic.


2005 ◽  
Vol 473-474 ◽  
pp. 429-434 ◽  
Author(s):  
Olga Verezub ◽  
György Kaptay ◽  
Tomiharu Matsushita ◽  
Kusuhiro Mukai

Penetration of model solid particles (polymer, teflon, nylon, alumina) into transparent model liquids (distilled water and aqueous solutions of KI) were recorded by a high speed (500 frames per second) camera, while the particles were dropped from different heights vertically on the still surface of the liquids. In all cases a cavity has been found to form behind the solid particle, penetrating into the liquid. For each particle/liquid combination the critical dropping height has been measured, above which the particle was able to penetrate into the bulk liquid. Based on this, the critical impact particle velocity, and also the critical Weber number of penetration have been established. The critical Weber number of penetration was modelled as a function of the contact angle, particle size and the ratio of the density of solid particles to the density of the liquid.


Author(s):  
OLGA MOSKALENKO ◽  
ROMAN YASKEVICH

A review of the literature on the current problem of medicine is presented. Arterial hypertension is one of the common chronic diseases for which the current goal of therapy is not recovery, but improvement of circulatory function with a satisfactory quality of life. The study of QOL and the factors influencing it can contribute to an increase in the individual effectiveness of treatment and complex rehabilitation of patients suffering from this pathology.


Author(s):  
Yannis Theocharis ◽  
Joost de Moor

Creative participation refers to citizens’ invention of, and engagement in, new action forms that aim to influence, or take responsibility for, the common good in society. By definition, these action forms are constantly evolving and cannot be listed or summarized. Yet some, like guerrilla gardening, have over time become more established in political repertoires, and specific arenas are known to be particularly productive sites for their development. These include in particular the Internet, and lifestyles and consumption. The constant changes in how citizens become active represented by creative participation present considerable challenges for scholars of political participation—both in terms of theory and methodology. In particular, such forms test our ability to distinguish political from nonpolitical activities. However, how political creative participation is, is often subtle and implicit, and therefore hard to establish. Yet being able to do so is essential for an ongoing assessment of the quality of participatory democracy. With conventional forms of participation declining and creative participation becoming more common, scholars must be able to agree on definitions and operationalizations that allow for the comparison of participatory trends. For instance, a key concern has been whether creative forms of participation crowd out more conventional ones, like voting or lobbying politicians. Developments in survey research have been able to show that this is not the case and that creative participation may in fact increase conventional participation. In addition, qualitative research methods like focus groups and ethnography, allow for more open-ended explorations of this elusive research topic. As to who participates, creative participation has enabled traditionally underrepresented groups like women and young people to catch up with, and sometimes overtake, those older men who have long dominated conventional political participation. Still, education remains a key obstacle even to creative participation. The COVID-19 crisis that took hold of the world in 2020 has compromised access to collective action and public space. It has thereby once more put the onus on citizens to engage creatively with ways to influence, and take responsibility for, society. At the same time, the crisis presents a need and opportunity for political participation scholarship to engage more deeply with theoretical debates about what it means to be political or to participate.


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