Role of inertia and thixotropy in start-up flows of aging soft materials: Transient dynamics and shear banding in a rate-controlled flow field

2018 ◽  
Vol 62 (4) ◽  
pp. 1001-1016 ◽  
Author(s):  
Anika Jain ◽  
Ramanish Singh ◽  
Lakshmi Kushwaha ◽  
V. Shankar ◽  
Yogesh M. Joshi
Keyword(s):  
Flow Field ◽  
Shear Banding ◽  
Soft Materials ◽  
Transient Dynamics ◽  
Start Up ◽  
Rate Controlled ◽  
Controlled Flow

The Role of Global Entrepreneurship in Utilizing Retired Workforce and Export Start-Up

2017 ◽  
Vol 21 (2) ◽  
pp. 23-44
Author(s):  
Kyungil Khoe ◽  
Hyuk-Jin Ko ◽  
Yeonsung Cho ◽  
Seon-U Kim
Keyword(s):  
Start Up ◽  
Global Entrepreneurship

scholarly journals Innovation Capabilities and the Performance of Start-Ups in Korea: The Role of Government Support Policies

2021 ◽  
Vol 13 (11) ◽  
pp. 6009
Author(s):  
Se-Kyoung Choi ◽  
Sangyun Han ◽  
Kyu-Tae Kwak
Keyword(s):  
Firm Performance ◽  
Financial Support ◽  
Political Support ◽  
Sustainable Growth ◽  
Government Support ◽  
Role Of Government ◽  
Positive Effects ◽  
Start Up ◽  
Start Ups

What kind of capacity is needed to improve the performance of start-ups? How effective are government support policies in improving start-up performance? Start-ups are critical firm group for ensuring the prospective and sustainable growth of an economy, and thus many countries’ governments have established support policies and they are likely to engage more widely in forward-looking political support activities to ensure further growth and expansion. In this paper, the effect of innovation capabilities and government support policies on start-up performance is examined. We used an unbalanced panel data analysis with a random effect generalized least squares. We investigated the effect of government support policies on 4368 Korean start-ups. The findings indicated that technology and knowledge capabilities had positive effects on the sales performance of start-ups, and government financial support positively affected the relationship between knowledge capability and firm performance. However, when government financial support increased, marketing capability was negatively associated with firm performance. These results demonstrate the significant role of government financial support, including its crowding in but also its crowding out effect. Practical implications: To be more effective, governments should employ innovation-driven entrepreneurship policy approaches to support start-ups. To improve their performance, start-ups need to increase their technology and knowledge capabilities. This study extends recent efforts to understand more fully the effect of government support policies on start-ups differing in their technology, knowledge, and marketing capabilities.

scholarly journals Hydrodynamics can determine the optimal route for microswimmer navigation

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Abdallah Daddi-Moussa-Ider ◽  
Hartmut Löwen ◽  
Benno Liebchen
Keyword(s):  
Flow Field ◽  
Hydrodynamic Interactions ◽  
Optimal Trajectories ◽  
Optimal Route ◽  
Active Particles ◽  
Navigation Strategy ◽  
Navigation Strategies

AbstractAs compared to the well explored problem of how to steer a macroscopic agent, like an airplane or a moon lander, to optimally reach a target, optimal navigation strategies for microswimmers experiencing hydrodynamic interactions with walls and obstacles are far-less understood. Here, we systematically explore this problem and show that the characteristic microswimmer-flow-field crucially influences the navigation strategy required to reach a target in the fastest way. The resulting optimal trajectories can have remarkable and non-intuitive shapes, which qualitatively differ from those of dry active particles or motile macroagents. Our results provide insights into the role of hydrodynamics and fluctuations on optimal navigation at the microscale, and suggest that microorganisms might have survival advantages when strategically controlling their distance to remote walls.

scholarly journals Universities and start-up creation by Ph.D. graduates: the role of scientific and social capital of academic laboratories

2021 ◽  
Author(s):  
Alessandro Muscio ◽  
Sotaro Shibayama ◽  
Laura Ramaciotti
Keyword(s):  
Social Capital ◽  
Training Period ◽  
Scientific Excellence ◽  
Academic Knowledge ◽  
Start Up ◽  
Industry Collaboration ◽  
Business Experience ◽  
Subject Areas ◽  
Scientific Capital

AbstractThis paper investigates how the characteristics of university laboratories influence the propensity of Ph.D. students to entrepreneurship, and thus, contribute to the transfer of academic knowledge to society. As determinants of Ph.D. entrepreneurship, we focus on the lab scientific and social capital as well as on the business experience that Ph.D. students acquire during their training period. The empirical exercise is based on questionnaire survey data of 5266 Ph.D. students in Italian universities in all subject areas. First, we find that 6.7% of the Ph.D. graduates engage in startup activities, and thus, Ph.D. training seems to contribute to knowledge transfer through entrepreneurship. Second, Ph.D. entrepreneurship is driven by business experience, in the forms of industry collaboration and industrially applicable research projects, during their training period. Third, the lab scientific capital is negatively associated with Ph.D. entrepreneurship, suggesting a conflict between scientific excellence and entrepreneurship, but this effect is mitigated if students acquire business experience. Fourth, the lab social capital increases the chance of startup when students have business experience. We further investigate the effects of lab environment by distinguishing between startups that are based on university research and startups that are not, finding different determinants.

Haemorheological Effects on Thrombocyte Adhesion and Aggregation Found Under Controlled Flow Conditions

1979 ◽  
Author(s):  
P.D. Richardson
Keyword(s):  
Rate Of Change ◽  
Continuous Observation ◽  
Flow Conditions ◽  
Wide Range ◽  
Stream Migration ◽  
Local Shear ◽  
Videotape Recording ◽  
Controlled Flow ◽  
A Site

Thrombocyte adhesion and aggregation in a vessel or on a chamber wall can be measured most readily if the flow is controlled and steady, and continuous observation is used. Videotape recording is very helpful for subsequent quantification of the dynamics. The adhesion of each thrombocyte can occur for a finite time interval:this interval has been observed to have a wide range. Platelets which escape often leave open a site which attracts other platelets preferentially. The rate of change of adhesion density (platelets/mm2) is affected by the local shear rate and the shear history upstream. Aggregation is affected similarly, and also proceeds with some platelet turnover. The role of erythrocytes in facilitating cross-stream migration of thrombocytes (which can enhance the growth rate of large thrombi) appears due in part to convective flow fields induced by the motion of erythrocytes in a shear flow, which can be demonstrated theoretically and experimentally. Observations of the phenomenlogy of adhesion and aggregation under controlled flow conditions and comparison with fLu id-dynamically based theory allows representation in terras of a small number of parameters with prospects of prediction of behaviour over a wide range of haemodynamic conditions; biochemical changes lead to changes in values of the parameters, so that activating agents and inhibiting agents modify values in different directions.

Numerical Simulation of Eddy Air-Curtain Dust Controlled Flow Field in Hard Rock Mechanized Driving Face

2012 ◽  
Vol 214 ◽  
pp. 440-444
Author(s):  
Wei Min Cheng ◽  
Wen Nie ◽  
Gang Zhou ◽  
Jun Lei Yang ◽  
Wen Zhou Du ◽  
...  
Keyword(s):  
Flow Field ◽  
Hard Rock ◽  
Equation Model ◽  
Polymer Materials ◽  
Radial Clearance ◽  
Air Curtain ◽  
Controlled Flow ◽  
Full Face ◽  
Local Dust ◽  
The Mathematical Model

The author established the mathematical model of single-phase flow of gas based on the k-ε two-equation model and numerically simulated the eddy air-curtain dust controlled flow field in hard rock mechanized driving face with the help of FLUENT software.The result showed that, after all the pressure ventilation blown out by the radial clearance of mural cylinder, a full-face eddy air-curtain flow field is formed at the roadway section, forming the air-curtain dust controlled flow field that presses the tunneling place equally in front of the driver of roadheader. After the application of the development of new light polymer materials radial cylinder eddy air-curtain dust controlled system was adopted in hard rock mechanized driving face of north conveyor main roadway, reducing the local dust concentration effectively.

The link between interpersonal and interorganisational networking: the role of start-up members' achievement-related affect

2021 ◽  
Vol 13 (1) ◽  
pp. 63
Author(s):  
Maria Beatriz Esperança ◽  
Aristides I. Ferreira ◽  
Catarina Correia Leal ◽  
Timo Braun
Keyword(s):  
Start Up

Flow Measurements in a Nozzle Guide Vane Passage With a Low Aspect Ratio and Endwall Contouring

2000 ◽  
Author(s):  
Steven W. Burd ◽  
Terrence W. Simon
Keyword(s):  
Aspect Ratio ◽  
Flow Field ◽  
Guide Vane ◽  
Flow Measurements ◽  
Vast Number ◽  
Aspect Ratios ◽  
Nozzle Guide Vane ◽  
Endwall Contouring ◽  
Nozzle Guide

The vast number of turbine cascade studies in the literature has been performed in straight-endwall, high-aspect-ratio, linear cascades. As a result, there has been little appreciation for the role of, and added complexity imposed by, reduced aspect ratios. There also has been little documentation of endwall profiling at these reduced spans. To examine the role of these factors on cascade hydrodynamics, a large-scale nozzle guide vane simulator was constructed at the Heat Transfer Laboratory of the University of Minnesota. This cascade is comprised of three airfoils between one contoured and one flat endwall. The geometries of the airfoils and endwalls, as well as the experimental conditions in the simulator, are representative of those in commercial operation. Measurements with hot-wire anemometry were taken to characterize the flow approaching the cascade. These measurements show that the flow field in this cascade is highly elliptic and influenced by pressure gradients that are established within the cascade. Exit flow field measurements with triple-sensor anemometry and pressure measurements within the cascade indicate that the acceleration imposed by endwall contouring and airfoil turning is able to suppress the size and strength of key secondary flow features. In addition, the flow field near the contoured endwall differs significantly from that adjacent to the straight endwall.

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