Proteinaceous Bubbles and Nano Particle Flows in Microchannel

2004 ◽  
Author(s):  
Jung-Yeul Jung ◽  
Ki-Taek Byun ◽  
Jae-Ho Hong ◽  
Ho-Young Kwak
Keyword(s):  
Flow Rate ◽  
Flow Behavior ◽  
Average Diameter ◽  
Scattering Method ◽  
Nano Particle ◽  
Test Results ◽  
Particle Flows ◽  
Flow Test ◽  
Before And After ◽  
Flow Through

Proteinaceous bubbles of 185 nm in average diameter were synthesized by a sonochemical treatment of bovine serum albumin in aqueous solution and the nanoparticles (TiO2) solution was made by ultrasonic irradiation. To study the macroscopic flow behavior associated with the changes in the state of microparticles, a flow test of these solutions in microchannels was done. Also the size distributions of the proteinaceous bubbles in solution before and after the flow test were measured by a light scattering method. Test results show that the air-filled proteinaceous bubbles in solution adjust their size to reduce the shear stress encountered in the flow through the microchannel. On the other hand, the flow rate of the solution with nanoparticles suspensions becomes smaller than that of deionized water above the flow rate of 6 cm3/min in the microchannel with a dimension of 100×150 μm2.

Effect of Surface State of Die on Flow Rate of Steamed Bamboo Powder in Thermal Flow Test Using Capillary Rheometer

2015 ◽  
Vol 651-653 ◽  
pp. 830-835
Author(s):  
Shohei Kajikawa ◽  
Riku Sakagami ◽  
Takashi Iizuka
Keyword(s):  
Particle Size ◽  
Flow Rate ◽  
Surface State ◽  
Flow Behavior ◽  
Thermal Flow ◽  
Average Roughness ◽  
Arithmetic Average ◽  
Flow Test ◽  
Die Surface ◽  
Bamboo Powder

Thermal flow tests were performed on steamed bamboo powder using capillaries that were processed under different conditions in order to investigate the effect of the die surface state on the fluidity of the woody powder. The capillaries were processed by wire-cut electric discharge machining, reaming or drilling, and the arithmetic average roughness (Ra) varied from 0.5 to 2.5 μm. The bamboo powder was first steamed at 200 °C for 20 min, and its particle size was then controlled using different mesh screens. The thermal flow temperature was set at 200 °C. The results indicated that the flow behavior improved with increasing particle size. For the capillaries processed by WEDM, the flow rate for samples with particle sizes of 75~150 and 150~300 μm decreased with increasing Ra. On the other hand, when reaming or drilling was used to process the capillaries, the flow rate was almost independent of Ra, regardless of the particle size.

scholarly journals Hysteresis in Oil Flow through a Rotating Tube with Twin Exit Branches

1997 ◽  
Vol 3 (4) ◽  
pp. 249-258 ◽  
Author(s):  
Sun-Wen Cheng ◽  
Wen-Jei Yang
Keyword(s):  
Flow Rate ◽  
Transmission Lines ◽  
Rotational Speed ◽  
Flow Behavior ◽  
Piping System ◽  
Air Bubbles ◽  
Two Phase ◽  
Oil Flow ◽  
Flow Through ◽  
Total Oil

Oil enters a horizontal rotating tube through a radially-attached duct at one end. The tube with the other end closed is attached with radial twin exit branches permitting oil to exit into open air. Air begins to enter through one of the two branches into the tube when its rotational speed reaches certain critical values. An experimental study is performed to investigate this air-oil two-phase flow behavior. Both the tube and the branches are transparent to allow illumination and flow visualization during spin-up and spin-down processes. The branch-totube diameter ratio, rotational speed, and oil flow rate are varied. Changes in oil flow rates are measured as a function of rotational speed. A comparison is made between cases of a varying total oil flow rate due to rotation effects and a constant one under control. It is disclosed that cavitation in oil flow is induced by air entering the branches opposite to the ejecting oil flow. Subsequently air bubbles progress in the tube. The origin of this intrusion depends on the hydraulic head loss of the piping system. This study can be applied to oil lubrication analysis of rotating machinery, such as automotive transmission lines.

The Effect of Stenotic Geometry and Non-newtonian Property of Blood Flow through Arterial Stenosis

2020 ◽  
Vol 20 (1) ◽  
pp. 16-30
Author(s):  
Somchai Sriyab
Keyword(s):  
Mathematical Model ◽  
Blood Flow ◽  
Skin Friction ◽  
Flow Rate ◽  
Flow Behavior ◽  
Blood Flow Rate ◽  
Stenosed Artery ◽  
Flow Through ◽  
Power Law Index ◽  
Newtonian Behavior

Background: A mathematical model of blood flow is a way to study the blood flow behavior. In this research work, a mathematical model of non-Newtonian blood flow through different stenosis, namely bell shape and cosine shape, is considered. The physiologically important flow quantities of blood flow behavior to describe the blood flow phenomena are obtained such as resistance to flow, skin friction and blood flow rate. Methods: Mathematical methods are used to analyze a mathematical model of blood flow through stenosed artery. The resistance to flow, skin friction and blood flow rate were obtained to describe the blood flow in stenosis. The resistance to flow is a relation between pressure and blood flow rate while the skin friction is the friction at the artery membrane. Results: The blood flow in cosine geometry exhibits higher resistance to flow and flow rate than in the bell geometry, while the blood flow in bell geometry gives a higher skin friction than in cosine geometry. Not only the effect of stenotic geometry was studied but also the effect of stenosis depth and stenosis height on the flow quantities Moreover, the power law index was adjusted to explore the non-Newtonian behavior. When blood exhibits Newtonian behavior, the resistance to flow and skin friction decrease but the blood flow rate increases. Conclusion: The stenosed artery geometry, the stenosis length, stenosis depth and the power law index (non-Newtonian behavior) are important factors affecting the blood flow through the stenosed artery. This work provides some potential aspects to further study the causes and development of cardiovascular diseases.

The Cross Flow Mechanism in the Micro Channel of a Polymer Electrolyte Fuel Cell

2013 ◽  
Author(s):  
K. M. Salahuddin ◽  
Nobuyuki Oshima ◽  
Litan Kumar Saha
Keyword(s):  
Fuel Cell ◽  
Flow Rate ◽  
Oxygen Transport ◽  
Gas Flow ◽  
Flow Behavior ◽  
Cross Flow ◽  
Polymer Electrolyte Fuel Cell ◽  
Micro Channel ◽  
Flow Through ◽  
The Cross

In this article we presented the recent activities in the field of gas flow in the micro channel and porous media of a polymer electrolyte fuel cell (PEFC). The gas flow behavior in the micro-channel, especially in the case of serpentine channel is very complex due to the appearance of cross flow through the gas diffusion layer (GDL). The gas flow behavior in the separator channel and GDL of a PEFC has been studied by using a transient, isothermal and three dimensional numerical models. To predict gas flow phenomena accurately the precise calculation of mass conversation is necessary which is strictly maintained in our present simulation. The effects of physical characteristics and geometrical properties have been investigated to quantify the amount of cross flow and pressure loss. The cross flow has been investigated in terms of volume mass flux through the GDL under the rib. The ratio cross flow rate to the total flow rate increases when gas channel pitch length decreased. Moreover, with increasing of permeability this ratio also increases. The effect of cross flow and bend region characteristics on the pressure loss has been identified. In addition, to isolate the contribution of cross flow on the performance of fuel cell, the simulation was carried out with electrochemical reaction using parallel straight channel. We designed a parallel flow field to induce artificial cross flow through the GDL. The numerical results show that the flow cross-over through the GDL under the rib significantly facilitate the oxygen transport towards the catalyst layer. Therefore, it is possible to overcome the oxygen transport limitation. Consequently, the cross flow can increase the current density by reducing the oxygen transport limitation, although this also increases the non-uniformity in current density.

MGP NAPL interception with organophyllic media: flow-through column test results

2006 ◽  
Vol 14 (2) ◽  
pp. 489-493
Author(s):  
Michael J. Gefell ◽  
Erin C. Rankin ◽  
William R. Jones
Keyword(s):  
Test Results ◽  
Column Test ◽  
Flow Through

Stabilization of the Speed of the Hydraulic Motor Through Throttle Compensation for Volume Losses

2020 ◽  
Vol 26 (3) ◽  
pp. 126-130
Author(s):  
Krasimir Kalev
Keyword(s):  
Flow Rate ◽  
Hydraulic Drive ◽  
Pressure Change ◽  
Operating Conditions ◽  
Drive System ◽  
Inlet Pressure ◽  
Schematic Diagram ◽  
Hydraulic Characteristics ◽  
Hydraulic Motor ◽  
Flow Through

AbstractA schematic diagram of a hydraulic drive system is provided to stabilize the speed of the working body by compensating for volumetric losses in the hydraulic motor. The diagram shows the inclusion of an originally developed self-adjusting choke whose flow rate in the inlet pressure change range tends to reverse - with increasing pressure the flow through it decreases. Dependent on the hydraulic characteristics of the hydraulic motor and the specific operating conditions.

Sunlight exposure: the effects on the performance of paragliding fabric

2018 ◽  
Vol 69 (05) ◽  
pp. 381-389
Author(s):  
MENGÜÇ GAMZE SÜPÜREN ◽  
TEMEL EMRAH ◽  
BOZDOĞAN FARUK
Keyword(s):  
Mechanical Properties ◽  
Aging Process ◽  
Air Permeability ◽  
Sunlight Exposure ◽  
Test Results ◽  
Coating Materials ◽  
Strength Tests ◽  
Before And After ◽  
The Relationship ◽  
Dark Blue

This study was designed to explore the relationship between sunlight exposure and the mechanical properties of paragliding fabrics which have different colors, densities, yarn counts, and coating materials. This study exposed 5 different colors of paragliding fabrics (red, turquoise, dark blue, orange, and white) to intense sunlight for 150 hours during the summer from 9:00 a.m. to 3:00 p.m. for 5 days a week for 5 weeks. Before and after the UV radiation aging process, the air permeability, tensile strength, tear strength, and bursting strength tests were performed. Test results were also evaluated using statistical methods. According to the results, the fading of the turquoise fabric was found to be the highest among the studied fabrics. It was determined that there is a significant decrease in the mechanical properties of the fabrics after sunlight exposure. After aging, the fabrics become considerably weaker in the case of mechanical properties due to the degradation in both the dyestuff and macromolecular structure of the fiber

Study of fluid flow through a channel deformed by piezoelement

2018 ◽  
Vol 13 (3) ◽  
pp. 1-10 ◽  
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh Nasibullaeva ◽  
O.V. Darintsev
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Boundary Conditions ◽  
Flow Rate ◽  
Contact Surface ◽  
Piezoelectric Element ◽  
Neumann Boundary ◽  
Differential Pressure ◽  
Physical Parameters ◽  
Flow Through

The flow of a liquid through a tube deformed by a piezoelectric cell under a harmonic law is studied in this paper. Linear deformations are compared for the Dirichlet and Neumann boundary conditions on the contact surface of the tube and piezoelectric element. The flow of fluid through a deformed channel for two flow regimes is investigated: in a tube with one closed end due to deformation of the tube; for a tube with two open ends due to deformation of the tube and the differential pressure applied to the channel. The flow rate of the liquid is calculated as a function of the frequency of the deformations, the pressure drop and the physical parameters of the liquid.

Upward Vertical Two-Phase Flow Through an Annulus—Part II: Modeling Bubble, Slug, and Annular Flow

1992 ◽  
Vol 114 (1) ◽  
pp. 14-30 ◽  
Author(s):  
E. F. Caetano ◽  
O. Shoham ◽  
J. P. Brill
Keyword(s):  
Flow Pattern ◽  
Annular Flow ◽  
Two Phase Flow ◽  
Flow Behavior ◽  
Bubble Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Through ◽  
Physical Phenomena ◽  
Good Agreement

Mechanistic models have been developed for each of the existing two-phase flow patterns in an annulus, namely bubble flow, dispersed bubble flow, slug flow, and annular flow. These models are based on two-phase flow physical phenomena and incorporate annulus characteristics such as casing and tubing diameters and degree of eccentricity. The models also apply the new predictive means for friction factor and Taylor bubble rise velocity presented in Part I. Given a set of flow conditions, the existing flow pattern in the system can be predicted. The developed models are applied next for predicting the flow behavior, including the average volumetric liquid holdup and the average total pressure gradient for the existing flow pattern. In general, good agreement was observed between the experimental data and model predictions.

scholarly journals An Empirical Study on the Application of Cooperative Learning to Comprehensive English Classes in a Chinese Independent College

2017 ◽  
Vol 10 (2) ◽  
pp. 94
Author(s):  
Ji Meng
Keyword(s):  
Cooperative Learning ◽  
Empirical Study ◽  
Test Results ◽  
Independent College ◽  
Language Competence ◽  
English Classes ◽  
Academic Level ◽  
Before And After ◽  
Posttest Questionnaire ◽  
Positive Impacts

This research investigated a comparison between the effect of cooperative learning and lecture teaching on Comprehensive English classes in a Chinese Independent College. An empirical study for two semesters was carried out in the forms of pretest, posttest, questionnaire and interviews. While control class was taught in the conventional way, experiment class was instructed based on cooperative base groups with positive interdependence structured on purpose. Compared with traditional instructions, cooperative learning as pedagogy can improve students’ performance on course exams, but not necessarily their language competence as shown in national English competency tests taken before and after the experiement. Test results also indicate students from experiment class who excelled in competency test outnumbered those from control class, revealing that cooperative learning has positive impacts especially on students at a relatively higher academic level. Questionaire results show that students are most inclined to agree they have more chances to practice the language in a cooperative environment.

Sign in / Sign up

Export Citation Format

Share Document