scholarly journals Mathematical Investigation of the Cavitation Phenomenon in the Nozzle with Partially Surface Wetting

2015 ◽  
Vol 23 (1) ◽  
pp. 25-30
Author(s):  
Jana Jablonská ◽  
Milada Kozubková ◽  
Barbora Zavadilová ◽  
Lukáš Zavadil
Keyword(s):  
Complex Shape ◽  
Great Influence ◽  
Material Surface ◽  
Pipeline System ◽  
Surface Wetting ◽  
Cavitation Phenomenon ◽  
Flow Parameters ◽  
Cavitation Region ◽  
Wall Wetting ◽  
The Impact

Abstract Partially surface wetting has a great influence on friction losses in the fluid flow in both the pipeline system and the complex shape of hydraulic elements. In many hydraulic elements (valves, pump impellers), cavitation is generated, which significantly changes the hydraulic flow parameters, so the last part of the article is devoted to the mathematical solution of this phenomena and evaluates the impact of wall wetting on the size and shape of the cavitation area which appears in the nozzle and in small gaps at special conditions. If the cavitation appears e. g. near the wall of pipes, the blades of turbine or a pump, then it destroys the material surface. On the basis of this physical experiment (nozzle), a two-dimensional (2D) mathematical cavitation model of Schnerr-Sauer was made and calculated shape and size of the cavitation region was compared with the experiment. Later this verified model of cavitation was used for cavitation research flow with partial surface wetting. The pressure drop and the size of the cavitation area as it flows from partially surface wetting theory was tested depending on the adhesion coefficient.

Role of Brand experience in Fashion brands

2019 ◽  
Vol 118 (1) ◽  
pp. 57-64
Author(s):  
G. Aiswarya ◽  
Dr. Jayasree Krishnan
Keyword(s):  
Factor Analysis ◽  
Purchase Intention ◽  
Great Influence ◽  
Brand Experience ◽  
Brand Preference ◽  
Mediating Role ◽  
Confirmatory Factor ◽  
Selling Strategies ◽  
The Impact

Traditionally the products were pushed into the hands of customers by production and selling strategies; then the marketing strategy evolved which gained momentum by understanding the customer needs and developing products satisfying those needs. This strategy is most prevalent and what should be done to stand up in this most competitive scenario? The answer to this key question is to create an experience. The customers now also seek good experiences than other benefits. Brand experience has gained more attention, especially fashion brands. Previous studies demonstrate the role of the brand experience in brand equity and other consumer behavior constructs. But very little is known about the impact of brand experiences on fashion brands. The aim of this study is to develop a model which makes our understanding better about the role of Brand preference and Brand experience and its influence on purchase intention of the brand. An initial exploratory study is conducted using a focus group to generate items for the study. The items, thus generated are prepared in the form of a questionnaire and samples were collected.  Exploratory factor analysis is conducted and the reliability of the constructs is determined. These constructs are loaded onto AMOS to perform Confirmatory factor analysis. The results confirmed the scales used. We also noticed that Brand preference has a great influence on the Brand experience. Thereby the finding supports the role of the brand experience which tends to have a mediating role in influencing the purchase intention.

Investigation of the Squeeze Film Dynamics Underneath a Microstructure With Large Oscillation Amplitudes and Inertia Effects

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Nadim A. Diab ◽  
Issam A. Lakkis
Keyword(s):  
Rarefied Gas ◽  
Direct Simulation Monte Carlo ◽  
Squeeze Film ◽  
Dsmc Method ◽  
Inertia Effects ◽  
Flow Parameters ◽  
Fluid Behavior ◽  
Dimensionless Groups ◽  
Simulation Monte Carlo ◽  
The Impact

This paper presents direct simulation Monte Carlo (DSMC) numerical investigation of the dynamic behavior of a gas film in a microbeam. The microbeam undergoes large amplitude harmonic motion between its equilibrium position and the fixed substrate underneath. Unlike previous work in literature, the beam undergoes large displacements throughout the film gap thickness and the behavior of the gas film along with its impact on the moving microstructure (force exerted by gas on the beam's front and back faces) is discussed. Since the gas film thickness is of the order of few microns (i.e., 0.01 < Kn < 1), the rarefied gas exists in the noncontinuum regime and, as such, the DSMC method is used to simulate the fluid behavior. The impact of the squeeze film on the beam is investigated over a range of frequencies and velocity amplitudes, corresponding to ranges of dimensionless flow parameters such as the Reynolds, Strouhal, and Mach numbers on the gas film behavior. Moreover, the behavior of compressibility pressure waves as a function of these dimensionless groups is discussed for different simulation case studies.

Assessment of Unsteady Flows in Turbines

1992 ◽  
Vol 114 (1) ◽  
pp. 79-90 ◽  
Author(s):  
O. P. Sharma ◽  
G. F. Pickett ◽  
R. H. Ni
Keyword(s):  
Unsteady Flow ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Experimental Investigations ◽  
Flow Parameters ◽  
Research Activities ◽  
Flow Features ◽  
Computational Fluid Dynamics Cfd ◽  
Turbine Design ◽  
The Impact

The impacts of unsteady flow research activities on flow simulation methods used in the turbine design process are assessed. Results from experimental investigations that identify the impact of periodic unsteadiness on the time-averaged flows in turbines and results from numerical simulations obtained by using three-dimensional unsteady Computational Fluid Dynamics (CFD) codes indicate that some of the unsteady flow features can be fairly accurately predicted. Flow parameters that can be modeled with existing steady CFD codes are distinguished from those that require unsteady codes.

The Science of Goal Setting

2012 ◽  
Vol 19 (1) ◽  
pp. 13-25 ◽  
Author(s):  
Daniel Hayden ◽  
Fangzhou Deng
Keyword(s):  
Goal Setting ◽  
Diffusion Of Innovation ◽  
Social Marketing ◽  
Collective Behavior ◽  
Great Influence ◽  
Environmental Conservation ◽  
Marketing Campaign ◽  
Social Marketing Campaign ◽  
Social Marketing Campaigns ◽  
The Impact

Goal setting within social marketing campaigns is art and science. An analysis of Rare Pride conservation campaigns shows the quantitative, replicable relationship among the impact of these conservation campaigns with diffusion of innovation theory, and collective behavior theory that can guide marketers to set better goals. Rare is an environmental conservation organization that focuses on reducing community-based threats to biodiversity through a social marketing campaign called Pride. Pride campaigns work by removing barriers to change (whether they are technical, social, and political or something else) and inspiring people to make change happen. Based on the analysis of historical Pride campaign survey data, we found that the starting percentage of engagement has a great influence on the percentage change at the end of the campaign: The higher the initial adoption level of knowledge, attitude, and behavior change, the easier these measures are to improve. The result also suggests a difference in the potential of change with different audience segments: It is easiest to change influencer, then general public, and finally resource user who are the target of the social marketing campaign. In this article, we will analyze how to use diffusion of innovation and collective behavior theories to explain the impact of campaigns, as well as how to set more attainable goals. This article is consistent with similar research in the field of public health, which should help marketers set goals more tightly, allocate resources more effectively, and better manage donor expectations.

Optimization of Trenched Film Cooling Using RSM Coupled CFD

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
V.G. Krishna Anand ◽  
K.M. Parammasivam
Keyword(s):  
Film Cooling ◽  
Three Dimensional ◽  
Response Surfaces ◽  
Test Surface ◽  
Response Factor ◽  
Film Cooling Effectiveness ◽  
Blowing Ratio ◽  
Flow Parameters ◽  
Considerable Impact ◽  
The Impact

AbstractThe trench film cooling employs film holes embedded in a slot created on the surface that requires protection from the impact of hot mainstream flow. The present investigation employs Response Surface Methodology (RSM) approach coupled with CFD analysis to develop a regression predictive model and to optimize the trench geometric and flow parameters viz., trench width (w), trench depth (d), film hole compound angle (β) and blowing ratio (M). The Area-averaged film cooling effectiveness (ȠAA) were chosen as a response factor for RSM and with trench design and flow parameters used as input factors for regression analysis. Analysis of variance (ANOVA) analysis was carried out on the regression model to identify the influence of individual parameters. Three dimensional response surfaces that relate the effect of input parameters on the response factor were analyzed. Experimental results of a case identified from the RSM matrix was found to correlate well with computational investigations. Results from the study indicate that the parameters d, β and M have considerable impact on film cooling performance of test surface with trenches.

A Review on Non-Asbestos Friction Materials: Material Composition and Manufacturing

2018 ◽  
Vol 1150 ◽  
pp. 22-42
Author(s):  
Dinesh Shinde ◽  
Kishore N. Mistry ◽  
Suyog Jhavar ◽  
Sunil Pathak
Keyword(s):  
Composite Materials ◽  
Material Properties ◽  
Single Phase ◽  
Friction Material ◽  
Material Surface ◽  
Surface Wear ◽  
Friction Modifier ◽  
Friction Materials ◽  
Morphological Studies ◽  
The Impact

The peculiar feature of friction materials to absorb the kinetic energy of rotating wheels of an automobile to control the speed makes them remarkable in automobile field. The regulation of speed cannot be achieved with the use of single phase material as a friction material. Consequently, the friction material should be comprised of composite materials which consist of several ingredients. Incidentally, the friction materials were formulated with friction modifier, binders, fillers and reinforcements. Due to its pleasant physical properties, asbestos was being used as a filler. Past few decades, it is found that asbestos causes dangerous cancer to its inhaler, which provides a scope its replacement. Several attempts have been made to find an alternative to the hazardous asbestos. The efforts made by different researchers for the impact of every composition of composite friction material in the field are reviewed and studied for their effect on the properties of friction material. Surface morphological studies of different friction material are compared to interpret the concept of surface wear and its correlation with material properties.

Erosion Mechanism and Sensitivity Parameter Analysis of Natural Gas Curved Pipeline

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Jie Zhang ◽  
Hao Yi ◽  
Zhuo Huang ◽  
Jiadai Du
Keyword(s):  
Natural Gas ◽  
Wear Rate ◽  
Shape Factor ◽  
Great Influence ◽  
Solid Particles ◽  
Parameter Analysis ◽  
Particle Collision ◽  
Erosion Wear ◽  
Gas Wells ◽  
The Impact

With the deepening of natural gas exploitation, the problem of sand production in gas wells is becoming more and more serious, especially in high-yield gas wells. The solid particles in natural gas are very likely to cause erosion and wear of downstream pipelines and throttling manifolds, which makes the pipeline ineffective. Once the pipeline is damaged, the natural gas leaks, which may cause serious catastrophic accidents. In this paper, the impact of sand particles on the pipeline wall is predicted by the analysis of the research on bent and continuous pipeline combined with particle collision model. The parameters of different particles (particle shape factor, particle velocity, and particle diameter), different bent parameters (angle, diameter, and curvature-to-diameter ratio), and the influence of different continuous pipeline parameters (assembly spacing and angle) are explored on the erosion and wear mechanism of curved pipeline. The results show that the shape of the particles has a great influence on the wear of the curved pipeline. As the shape factor of the particles decreases, the wear tends to decrease. The bent area is subject to erosion changes as the particle parameters and piping parameters. The increase in pipeline diameter is beneficial to reduce the maximum and the average erosion wear rate. When the bent angle of the pipeline is less than 90 deg, the maximum erosion wear rate is basically the same. But when it is greater than 90 deg, it decreases with the increase in the bent angle. When the assembly angle of double curved pipeline is between 0 deg and 60 deg, the elbow is subject to severe erosion wear. At the same time, increasing the assembly spacing is beneficial to reduce the erosion wear rate. The research can provide a theoretical support for subsequent engineering applications.

scholarly journals The Spread of Corrosion in Cast Iron and its Effect on the Life Cycle of Transportation Vehicles

2017 ◽  
Vol 65 (2) ◽  
pp. 383-389 ◽  
Author(s):  
Tomáš Binar ◽  
Jiří Švarc ◽  
Petr Dostál ◽  
Michal Šustr ◽  
Jan Tippner
Keyword(s):  
Impact Strength ◽  
Fractographic Analysis ◽  
Bending Test ◽  
Material Surface ◽  
Bending Tests ◽  
Corrosion Tests ◽  
Fracture Surfaces ◽  
Impact Bending ◽  
Notch Impact Strength ◽  
The Impact

This article deals with the spread of corrosion in material at different exposure times, and its effect on the measured brittle fracture and notch impact strength under different temperature conditions. To assess the degradational effect of corrosion on the material characteristics represented by the measured impact strength, we conducted a fractographic analysis of fracture surfaces, the aim of which was to evaluate the spread of corrosion in the material. In the first part of the experiment, two corrosion tests are simulated with a duration time of 432 and 648 hours, to compare the degradation effect of corrosion on the notch impact strength, depending on the duration of the corrosion tests. The following part shows the results of the impact bending test, where the experiment was conducted in an area of reduced and increased temperatures. The final part summarizes the results of the fractographic analysis of sample fracture surfaces from the impact bending tests. Based on the measured the length of the corrosion cracks, we analyzed the sample at the notch and from the material surface after the impact bending test.

scholarly journals THE IMPACT OF FAMILY ENVIRONMENT ON CHILDREN’S ANXIETY LEVEL/ ŠEIMOS APLINKOS POVEIKIS VAIKO NERIMO LYGIUI

2019 ◽  
Vol 1 (38) ◽  
pp. 191
Author(s):  
Mieczysław Dudek ◽  
Eva Dolinská ◽  
Vladimir Klein ◽  
Viera Šilonová
Keyword(s):  
Family Environment ◽  
Urban Areas ◽  
Developmental Disorders ◽  
Great Influence ◽  
Adult Life ◽  
Anxiety Level ◽  
Rural And Urban Areas ◽  
Rural And Urban ◽  
Children’S Anxiety ◽  
The Impact

<p>Family and emotional relationships governing its functioning have a great influence upon the development of a person and his/her adult life. The specificity of a family environment is believed to be the key factor which either protects against, or contributes to, the emergence of developmental disorders during adolescence. Research results<br />presented in this paper aim at highlighting the relationships between traits of family environment and children’s anxiety level. The research was conducted from 2015 to 2016 among 180 students of Polish junior high schools located in both: rural and urban areas.</p><p> Šeima ir emociniai ryšiai daro didelę įtaką vaiko raidai ir suaugusiojo gyvenimui. Manoma, kad šeimos aplinkos specifika yra esminis veiksnys, kuris arba apsaugo nuo vystymosi sutrikimų paauglystės laikotarpiu atsiradimo, arba juos sukelia. Straipsnyje pateikiami tyrimų rezultatai siekia pabrėžti ryšį tarp šeimos aplinkos ypatybių ir vaikų nerimo lygio. Tyrimas buvo atliekamas 2015 m., apklausiant 180 Lenkijos aukštesniųjų<br />klasių mokinių iš kaimiškųjų vietovių ir miestų</p>

scholarly journals Evaluation of women’s quality of life after breast reconstruction surgery

2020 ◽  
Vol 66 (2) ◽  
Author(s):  
Marta Stanisz ◽  
Ewelina Kolak ◽  
Dorota Branecka-Woźniak ◽  
Renata Robaszkiewicz-Boukaz ◽  
Przemysław Ciepiela ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Quality Of Life ◽  
Breast Reconstruction ◽  
Great Influence ◽  
Well Being ◽  
World Health ◽  
World Health Organization Quality ◽  
Reconstruction Surgery ◽  
The Impact

Introduction: Breast cancer is the most common malignancy among women, and is usually treated surgically. Mastectomy has a great influence on the mental and physical condition of women. Breast reconstruction offers them a chance to improve their quality of life (QOL) and self-image.The main aim of the study was to gain knowledge about the impact of breast reconstruction on the QOL of women following mastectomy, and an analysis of the QOL after breast reconstruction, in the context of prosthesis effect assessment.Materials and methods: The study comprised 100 women following breast reconstructive surgery involved in 1 of the 7 “Amazon Clubs” (post-mastectomy women’s associations) in the West Pomeranian Voivodeship, northwest Poland. The study was based on the author’s questionnaire, and a shortened standardized version of the World Health Organization Quality of Life-BREF (WHOQOL-BREF) questionnaire. Statistical calculations were performed with StatSoft Statistica v10 software, adopting a significance level of p < 0.05.Results: The women who decided to have breast reconstruction surgery, noticed improved well-being (67%) and experiencedan increase in self-confidence (61%). The vast majority ofthe patients surveyed (93%) were satisfied with the effectof the prosthesis. Statistically significant differences in QOL were observed in the following spheres: rest and sleep, work capacity, negative feelings, and financial resources (p < 0.05) in relation to the evaluation of the prosthesis effect.Conclusions: 1. Breast reconstruction has a positive influence on improvements in well-being, increasing self-esteem, and the assessment of a more attractive appearance in women of all ages. 2. Breast reconstruction surgery has a positive impact on QOL and health in the physical, psychological, and environmental domains, especially in the women who are satisfied with the effects of the surgery. 3. A negative assessment of the breast reconstruction effect has an adverse influence on QOL. Identifying the factors affecting dissatisfaction with the post-operative outcome is crucial for a complete understanding of the subject, and for implementing measures aimed at improving the QOL of these women.Keywords: quality of life; mastectomy; breast cancer; breast reconstruction; breast surgery.

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