Fluid mechanics and sound generation for lung-clearance therapy

2017 ◽  
Vol 27 (4) ◽  
pp. 820-838
Author(s):  
John Gorman ◽  
Eph Sparrow ◽  
Kevin Krautbauer
Keyword(s):  
Fluid Flow ◽  
Fluid Mechanics ◽  
Design Methodology ◽  
Complete System ◽  
Fluid Velocity ◽  
Fluid Motion ◽  
Sound Generation ◽  
Content Type ◽  
Primary Means ◽  
Therapeutic Device

Purpose The study described here aims to set forth an analysis approach for a specific biomedical therapeutic device principally involving fluid mechanics and resulting sound generation. The function of the therapeutic device is to clear mucus from the airways of the lungs. Clearance of the airways is a primary means of relief for cystic fibrosis and is also effective in less profound dysfunctions such as asthma. The complete system consists of a device to periodically pulse air pressure and a vest that girdles the abdomen of the patient and receives and discharges the pulsating airflow. The source of pulsed air can be tuned both with respect to the amplitude and frequency of the pressure pulsations. Design/methodology/approach The key design tools used here are computational fluid dynamics and the theory of turbulence-based sound generation. The fluid flow inside of the device is multidimensional, unsteady and turbulent. Findings Results provided by the fluid mechanic study include the rates of fluid flow between the device and the inflatable vest, the rates of air supplied to and extracted from the device, the fluid velocity magnitudes and directions that result from the geometry of the device and the magnitude of the turbulence generated by the fluid motion and the rotating component of the device. Both the velocity magnitudes and the strength of the turbulence contribute to the quantitative evaluation of the sound generation. Originality/value A comprehensive literature search on this type of therapeutic device to clear mucus from the airways of the lungs revealed no previous analysis of the fluid flow and sound generation inside of the device producing the pulsed airflow. The results presented in this paper pinpoint the locations and causes of sound generation that can cause audible discomfort for patients.

Relative exploration orientation and real options reasoning: survey evidence from Denmark

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Claus Højmark Jensen ◽  
Thomas Borup Kristensen
Keyword(s):  
Real Options ◽  
Design Methodology ◽  
Complete System ◽  
Service Innovation ◽  
Downside Risk ◽  
Survey Method ◽  
Chief Financial Officer ◽  
Content Type ◽  
Multidimensional Construct ◽  
Product Service

Purpose This paper aims to extend the understanding of how real options reasoning (ROR) is associated with downside risk and how a firm’s portfolio (explore and exploit) of investment activities affects managers’ ability to effectively apply ROR in relation to downside risk. Design/methodology/approach The survey method is used. It is applied to a population of Danish firms, which in 2018 had more than 100 employees. The chief financial officer was the target respondent. Findings This study finds that a higher level of ROR is associated with lower levels of downside risk. ROR’s association with lower levels of the downside risk is also moderated by the level of relative exploration orientation in a negative direction. Originality/value The field of ROR research on downside risk and portfolio subadditivity has been dominated by research focused on multinationality. This paper extends extant literature on ROR by studying ROR as a multidimensional construct of firm action, which is associated with lower levels of downside risk, also when studied outside of a multinationality setting. This is the case when ROR is implemented as a complete system. This paper also applies a framework of exploitation and exploration to show that findings on subadditivity in options portfolios caused by asset correlations extend outside the scope of multinationality and into one of product/service innovation.

Robustness of convergence demonstrated byparametric-guiding andcomplex-root-tunneling algorithms for Bratu’s problem

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zhi Liu ◽  
Tienmo Shih ◽  
Zhong Chen
Keyword(s):  
Fluid Flow ◽  
Boundary Value Problem ◽  
Design Methodology ◽  
Initial Conditions ◽  
Complex Root ◽  
Content Type ◽  
Related Literature ◽  
Bratu’S Problem ◽  
Newton Raphson ◽  
Heat And Fluid Flow

Purpose This study aims to propose the parametric-guiding algorithm, the complex-root (CR) tunneling algorithm and the method that integrates both algorithms for the heat and fluid flow (HFF) community, and apply them to nonlinear Bratu’s boundary-value problem (BVP) and Blasius BVP. Design/methodology/approach In the first algorithm, iterations are primarily guided by a diminishing parameter that is introduced to reduce magnitudes of fictitious source terms. In the second algorithm, when iteration-related barriers are encountered, CRs are generated to tunnel through the barrier. At the exit of the tunnel, imaginary parts of CRs are trimmed. Findings In terms of the robustness of convergence, the proposed method outperforms the traditional Newton–Raphson (NR) method. For most pulsed initial guesses that resemble pulsed initial conditions for the transient Bratu BVP, the proposed method has not failed to converge. Originality/value To the best of the authors’ knowledge, the parametric-guiding algorithm, the CR tunneling algorithm and the method that integrates both have not been reported in the computational-HFF-related literature.

Stratified flow of sutterby fluid with homogeneous-heterogeneous reactions and Cattaneo-Christov heat flux

2019 ◽  
Vol 29 (8) ◽  
pp. 2977-2992 ◽  
Author(s):  
Muhammad Ijaz Khan ◽  
Sumaira Qayyum ◽  
Tasawar Hayat ◽  
Ahmed Alsaedi
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Fluid Flow ◽  
Nonlinear Equations ◽  
Thermal Stratification ◽  
Design Methodology ◽  
Rotating Disk ◽  
Heterogeneous Reactions ◽  
Content Type ◽  
Stratification Effect

Purpose The purpose of this paper is to analyze the Sutterby fluid flow by a rotating disk with homogeneous-heterogeneous reactions. Inspection of heat transfer is through Cattaneo–Christov model. Stratification effect is also considered. Design/methodology/approach Nonlinear equations are solved by the homotopy technique. Findings Sutterby fluid flow by rotating disk is not considered yet. Here the authors intend to analyze it with Cattaneo–Christov heat flux and homogeneous-heterogeneous reactions. Thermal stratification is also taken into consideration. Originality/value No such work is yet done in the literature.

Gaussons

2016 ◽  
Vol 26 (6) ◽  
pp. 1699-1709 ◽  
Author(s):  
Abdul-Majid Wazwaz
Keyword(s):  
Fluid Flow ◽  
Nonlinear Equations ◽  
Solitary Waves ◽  
Efficient Algorithm ◽  
Design Methodology ◽  
Boussinesq Equations ◽  
Content Type ◽  
Higher Dimensional ◽  
Propagation Of Waves ◽  
Practical Implications

Purpose – The purpose of this paper is to concern with a reliable treatment of the (2+1)-dimensional and the (3+1)-dimensional logarithmic Boussinesq equations (BEs). The author uses the sense of the Gaussian solitary waves to determine these gaussons. The study confirms that models characterized by logarithmic nonlinearity give gaussons solitons of distinct physical structures. Design/methodology/approach – The proposed technique, as presented in this work has been shown to be very efficient for solving nonlinear equations with logarithmic nonlinearity. Findings – The (2+1) and the (3+1)-dimensional BEs were examined as well. The examined models feature interesting results in propagation of waves and fluid flow. Research limitations/implications – The paper presents a new efficient algorithm for the higher dimensional logarithmic BEs. Practical implications – The work shows the effect of logarithmic nonlinearity compared to other nonlinearities where standard solitons appear in the last case. Social implications – The work will benefit audience who are willing to examine the effect of logarithmic nonlinearity. Originality/value – The paper presents a new efficient algorithm for the higher dimensional logarithmic BEs.

Supply chain integration for middle-market firms: a qualitative investigation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Matthew Schwieterman ◽  
Manus Rungtusanatham ◽  
Thomas J. Goldsby ◽  
W.C. Benton ◽  
Martha C. Cooper ◽  
...  
Keyword(s):  
Supply Chain ◽  
Design Methodology ◽  
Supply Chain Integration ◽  
Positive Outcomes ◽  
Content Type ◽  
Written Form ◽  
Primary Means ◽  
Context Specific ◽  
Middle Market ◽  
Practical Implications

PurposeThis research seeks to identify the motivations, means and outcomes of supply chain integration (SCI) among firms in the middle market (i.e. those with annual revenues between US$10m and US$1bn). These firms often interface with larger, more powerful firms in the supply chain – both suppliers and customers. Understanding how these firms are challenged and benefit from integrative mechanisms in supply chain relations can lead to better outcomes more often.Design/methodology/approachThe research utilizes an online focus group methodology featuring 39 participants. The participants were able to interact in written form with a professional moderator, as well as each other, over the course of three days.FindingsThe research presents evidence that firms in the middle market adopt SCI as a response to pressure from customers and suppliers. These firms also view technology as a primary means of achieving integration. Despite their disadvantageous size position relative to larger customers and suppliers, firms in the middle market achieved positive outcomes from integration.Research limitations/implicationsBecause of the specific context of middle-market firms, this research may lack generalizability. However, providing contextualization regarding firm size contributes specificity to the large number of studies detailing the challenges and benefits of SCI.Practical implicationsManagers of firms in the middle market should find value in this study as it explicates the possible benefits their firms may realize through integration with customers and suppliers. Moreover, this research outlines several of the possible means through which integration can be achieved. Further, managers in smaller and larger firms can better understand the motives and needs of middle-market companies with which they interact.Originality/valueDespite voluminous literature on SCI, this paper provides context-specific findings by isolating the implications of SCI to firms in the middle market.

SPH-Based Numerical Modeling of Fluid Flow Interaction with Various Shapes of Breakwater

2019 ◽  
Author(s):  
Rezaldy Naufal Saleh ◽  
Dede Tarwidi ◽  
Jondri
Keyword(s):  
Numerical Modeling ◽  
Fluid Flow ◽  
Coastal Erosion ◽  
Fluid Velocity ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Maximum Velocity ◽  
Sph Method ◽  
Flow Interaction ◽  
Scale Down

Various efforts have been made to prevent coastal erosion. One of the efforts to prevent coastal erosion is to build breakwaters. This paper presents numerical modeling of fluid flow interaction with various shapes of breakwater. Fluid flow impact on different shapes of breakwater, i.e. trapezoidal prism, cylinder, and sphere has been investigated. The three-dimensional numerical modeling is purposed to decisive which breakwaters shape that can reduce the fluid velocity rapidly, compared to other tested breakwaters shapes. In this study, fluid motion is generated by dam break scheme. The fluid motion is governed by momentum and continuity equation. The equations of fluid motion are resolved by smoothed particle hydrodynamics (SPH) method. DualSPHysics, an open-source code based on SPH method, is applied to simulate fluid motion and the interaction with the blocks of breakwater. According to numerical results, the trapezoidal prism shape of breakwater can scale down the fluid velocity faster than the cylinder and sphere shape of breakwater with maximum velocity is about 2.20 m/s. Further, the cylinder shape yields the highest fluid velocity around the breakwater. The trapezoidal prism shape can be used as an effective breakwater.

An initial field trial of a haptic navigation system for persons with a visual impairment

2015 ◽  
Vol 9 (4) ◽  
pp. 199-206 ◽  
Author(s):  
Daniel Innala Ahlmark ◽  
Maria Prellwitz ◽  
Jenny Röding ◽  
Lars Nyberg ◽  
Kalevi Hyyppä
Keyword(s):  
Visual Impairment ◽  
Navigation System ◽  
Field Trial ◽  
Design Methodology ◽  
Prior Training ◽  
Initial Field ◽  
User Experiences ◽  
Content Type ◽  
Primary Means ◽  
White Cane

Purpose – The purpose of this paper is to describe conceptions of feasibility of a haptic navigation system for persons with a visual impairment (VI). Design/methodology/approach – Six persons with a VI who were white cane users were tasked with traversing a predetermined route in a corridor environment using the haptic navigation system. To see whether white cane experience translated to using the system, the participants received no prior training. The procedures were video-recorded, and the participants were interviewed about their conceptions of using the system. The interviews were analyzed using content analysis, where inductively generated codes that emerged from the data were clustered together and formulated into categories. Findings – The participants quickly figured out how to use the system, and soon adopted their own usage technique. Despite this, locating objects was difficult. The interviews highlighted the desire to be able to feel at a distance, with several scenarios presented to illustrate current problems. The participants noted that their previous white cane experience helped, but that it nevertheless would take a lot of practice to master using this system. The potential for the device to increase security in unfamiliar environments was mentioned. Practical problems with the prototype were also discussed, notably the lack of auditory feedback. Originality/value – One novel aspect of this field trial is the way it was carried out. Prior training was intentionally not provided, which means that the findings reflect immediate user experiences. The findings confirm the value of being able to perceive things beyond the range of the white cane; at the same time, the participants expressed concerns about that ability. Another key feature is that the prototype should be seen as a navigation aid rather than an obstacle avoidance device, despite the interaction similarities with the white cane. As such, the intent is not to replace the white cane as a primary means of detecting obstacles.

Gesture-based animated CAPTCHA

2016 ◽  
Vol 24 (3) ◽  
pp. 242-254 ◽  
Author(s):  
Artem Shumilov ◽  
Andrey Philippovich
Keyword(s):  
Sign Language ◽  
Design Methodology ◽  
Additional Data ◽  
Turing Test ◽  
General Purpose ◽  
Hand Gestures ◽  
Sign Languages ◽  
Content Type ◽  
Primary Means ◽  
Automatic Algorithm

Purpose This paper aims to describe the development of a new experimental CAPTCHA (completely automated public turing test to tell computers and humans apart), which is supposed to provide better protection against spam bots compared to the existing captcha solutions. Design/methodology/approach In the new CAPTCHA, the authors are using animated images of hand gestures to represent letters and numbers. A lot of people use sign language as their primary means of communication, but an automatic algorithm able to reliably recognize such gestures from videos without any additional data has yet to be developed. Findings The experiment showed that at first, it takes time for people who do not use sign languages in their everyday lives to adapt to the new CAPTCHA, but after several successful recognitions, they have no more trouble with it than with a typical captcha implementation. Originality/value The paper shows that people with little to no knowledge of sign languages can still recognize gestures on video relatively fast. Therefore, a gesture-based implementation can be used not only on websites aimed at sign language speakers but also as a general-purpose captcha service.

Mathematical analysis of thermally radiative time-dependent Sisko nanofluid flow for curved surface

2019 ◽  
Vol 29 (9) ◽  
pp. 3498-3514 ◽  
Author(s):  
Waqar Azeem Khan ◽  
Muhammad Waqas ◽  
Mehboob Ali ◽  
F. Sultan ◽  
M. Shahzad ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Brownian Motion ◽  
Fluid Flow ◽  
Velocity Profile ◽  
Design Methodology ◽  
Time Dependent ◽  
Nanofluid Flow ◽  
Sisko Fluid ◽  
Content Type ◽  
Curvature Parameter

Purpose This paper aims to develop a mathematical model featuring Brownian motion and thermophoresis. The idea of curved stretching subjected to time-dependent non-Newtonian (Sisko) fluid flow is introduced. Design/methodology/approach Shooting scheme is implemented to compute nonlinear systems. Findings Velocity profile of Sisko magnetonanofluid enhances for augmented values of curvature parameter. Originality/value To the best of the authors’ knowledge, no such analysis has yet been reported.

Resist the list

2014 ◽  
Vol 27 (1) ◽  
pp. 2-5 ◽  
Author(s):  
Anthony McMullen
Keyword(s):  
Design Methodology ◽  
Anecdotal Evidence ◽  
Electronic Resources ◽  
Professional Literature ◽  
Content Type ◽  
Limited Budget ◽  
Search Service ◽  
Extra Step ◽  
Primary Means ◽  
Changing Times

Purpose – The purpose of this study is to provide insights into issues encountered in maintaining library technologies and electronic collections in changing times and on a limited budget with limited personnel. Design/methodology/approach – The study uses real world observations and experiences, data collected from an informal survey, insights gleaned from the professional literature and anecdotal evidence to provide commentary on the questionable methods many libraries employ in providing access to electronic resources. Findings – Libraries spend large sums of money and significant percentages of overall budgets on electronic resources, yet many fail to take the extra step to provide access to the content in these disparate resources via a web scale discovery search service. What is worse is that a large number of libraries still employ the flawed “Databases A-Z” list as a primary means of providing access. Originality/value – This paper is a light-hearted piece on one librarian’s observations regarding the inherent flaws in the traditional “Databases A-Z” list. It includes data from an informal survey.

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