EFFECTS OF SURFACE PROPERTIES ON FLUID ENGINEERING GENERATED BY THE SURFACE-DRIVEN CAPILLARY FLOW OF WATER IN MICROFLUIDIC LAB-ON-A-CHIP SYSTEMS FOR BIOENGINEERING APPLICATIONS

2017 ◽  
Vol 24 (03) ◽  
pp. 1750041 ◽  
Author(s):  
SUBHADEEP MUKHOPADHYAY ◽  
JYOTI PRASAD BANERJEE ◽  
SUSANTA SINHA ROY ◽  
SANJEEV KUMAR METYA ◽  
MARK TWEEDIE ◽  
...  
Keyword(s):  
Water Flow ◽  
Capillary Flow ◽  
Separation Efficiency ◽  
Experimental Studies ◽  
Lab On A Chip ◽  
Microfluidic Devices ◽  
Bend Angle ◽  
Separation Time ◽  
Novel Approach ◽  
Flow Features

In this research paper, in total 212 individual leakage-free Polymethylmethacrylate (PMMA) microfluidic devices are fabricated by maskless lithography, hot embossing lithography and direct bonding technique. The effect of channel aspect ratio on dyed water flow is investigated using these microfluidic devices. Experimental studies show that the dyed water flow is faster on the surface of higher wettability. The effect of capillary pressure on dyed water flow is studied in the fabricated PMMA microfluidic devices. According to the experimental observations, the centrifugal force has prominent effect on the dyed water flow. Also, the effect of bend angle is investigated on the surface-driven capillary flow of water. The polystyrene microparticles have been separated in the microfluidic lab-on-a-chip systems using the investigated flow features. A 100% separation efficiency is achieved in these lab-on-a-chip systems. These microfluidic lab-on-a-chip systems can be used to separate blood cells from human whole blood for further clinical tests. These experimental studies are important in bioengineering applications. The effect of bend angle as channel geometry to control the surface-driven capillary flow is investigated as a novel approach to control the separation time in microfluidic lab-on-a-chip systems. Also, the effect of surface wettability as surface property to control the surface-driven capillary flow is investigated as a novel approach to control the separation time in microfluidic lab-on-a-chip systems.

EXPERIMENTAL INVESTIGATIONS ON THE INTERACTIONS BETWEEN LIQUIDS AND STRUCTURES TO PASSIVELY CONTROL THE SURFACE-DRIVEN CAPILLARY FLOW IN MICROFLUIDIC LAB-ON-A-CHIP SYSTEMS TO SEPARATE THE MICROPARTICLES FOR BIOENGINEERING APPLICATIONS

2016 ◽  
Vol 24 (06) ◽  
pp. 1750075 ◽  
Author(s):  
SUBHADEEP MUKHOPADHYAY
Keyword(s):  
Surface Area ◽  
Capillary Flow ◽  
Separation Efficiency ◽  
Volume Ratio ◽  
Lab On A Chip ◽  
Microfluidic Devices ◽  
Research Paper ◽  
Novel Approach ◽  
The Individual ◽  
Effect Of Surface

In this research paper, total 246 individual microfluidic devices have been fabricated by maskless lithography, hot embossing lithography and direct bonding technique. The effect of surface area to volume ratio on the surface-driven capillary flow of different liquids has been experimentally investigated in these microfluidic devices fabricated by polymethylmethacrylate (PMMA). Also, the individual effects of liquid viscosity and surface wettability on the surface-driven capillary flow of different liquids are experimentally investigated. The polystyrene particles of 10[Formula: see text][Formula: see text]m diameters have been separated from the aqueous microparticle suspensions in the microfluidic lab-on-a-chip systems with 100% separation efficiency. Also, the polystyrene particles of 5[Formula: see text][Formula: see text]m diameters have been separated from a different set of aqueous microparticle suspensions in the microfluidic lab-on-a-chip systems with 100% separation efficiency. The individual designs of the microfluidic lab-on-a-chip systems are a novel approach in this research paper. The effect of surface area to volume ratio on the separation time is experimentally investigated as another novel approach of this research paper.

EXPERIMENTAL INVESTIGATIONS ON THE SURFACE-DRIVEN CAPILLARY FLOW OF AQUEOUS MICROPARTICLE SUSPENSIONS IN THE MICROFLUIDIC LABORATORY-ON-A-CHIP SYSTEMS

2017 ◽  
Vol 24 (08) ◽  
pp. 1750107
Author(s):  
SUBHADEEP MUKHOPADHYAY
Keyword(s):  
Capillary Flow ◽  
Separation Efficiency ◽  
Research Work ◽  
Lab On A Chip ◽  
Experimental Investigations ◽  
Separation Mechanism ◽  
Microfluidic Flow ◽  
Channel Aspect Ratio ◽  
Size Based Separation ◽  
Audio Video

In this work, total 1592 individual leakage-free polymethylmethacrylate (PMMA) microfluidic devices as laboratory-on-a-chip systems are fabricated by maskless lithography, hot embossing lithography, and direct bonding technique. Total 1094 individual Audio Video Interleave Files as experimental outputs related to the surface-driven capillary flow have been recorded and analyzed. The influence of effective viscosity, effect of surface wettability, effect of channel aspect ratio, and effect of centrifugal force on the surface-driven microfluidic flow of aqueous microparticle suspensions have been successfully and individually investigated in these laboratory-on-a-chip systems. Also, 5 micron polystyrene particles have been separated from the aqueous microparticle suspensions in the microfluidic lab-on-a-chip systems of modified design with 98% separation efficiency, and 10 micron polystyrene particles have been separated with 100% separation efficiency. About the novelty of this work, the experimental investigations have been performed on the surface-driven microfluidic flow of aqueous microparticle suspensions with the investigations on the separation time in particle-size based separation mechanism to control these suspensions in the microfluidic lab-on-a-chip systems. This research work contains a total of 10,112 individual experimental outputs obtained using total 30 individual instruments by author’s own hands-on completely during more than three years continuously. Author has performed the experimental investigations on both the fluid statics and fluid dynamics to develop an automated fluid machine.

EXPERIMENTAL STUDIES OF SURFACE-DRIVEN CAPILLARY FLOW IN PMMA MICROFLUIDIC DEVICES PREPARED BY DIRECT BONDING TECHNIQUE AND PASSIVE SEPARATION OF MICROPARTICLES IN MICROFLUIDIC LABORATORY-ON-A-CHIP SYSTEMS

2015 ◽  
Vol 22 (04) ◽  
pp. 1550050 ◽  
Author(s):  
SUBHADEEP MUKHOPADHYAY ◽  
J. P. BANERJEE ◽  
ASHISH MATHUR ◽  
M. TWEEDIE ◽  
J. A. MCLAUGHLIN ◽  
...  
Keyword(s):  
Barrier Discharge ◽  
Capillary Flow ◽  
Experimental Studies ◽  
Microfluidic Devices ◽  
Dbd Plasma ◽  
Dielectric Barrier ◽  
Passive Separation ◽  
Polystyrene Microparticles ◽  
Bonding Technique ◽  
Effect Of Surface

Proper bonding technique is investigated to achieve leakage-free surface-driven capillary flow in polymethylmethacrylate (PMMA) microfluidic devices. SU-8-based silicon stamp is fabricated by maskless lithography. This stamp is used to produce PMMA microchannel structure by hot embossing lithography. A direct bonding technique is mainly employed for leakage-free sealing inside PMMA microfluidic devices. The effect of surface wettability on surface-driven capillary flow is also investigated in PMMA microfluidic devices. The separation of polystyrene microparticles in PMMA laboratory-on-a-chip systems is investigated with the reduction of separation time by air dielectric barrier discharge (DBD) plasma processing of channel surfaces. This study is useful to fabricate the microfluidic laboratory-on-a-chip systems and to understand the surface-driven capillary flow.

Experimental Studies Concerning the Semipermeable Membrane Separation Efficiency for 134Cs, 137Cs, 57Co, 58Co, 60Co, 54Mn in Liquid Radioactive Waste I. Treatment of secondary waste from POD decontamination procedure

2008 ◽  
Vol 59 (5) ◽  
Author(s):  
Mirela Dulama ◽  
Nicoleta Deneanu ◽  
Cristian Dulama ◽  
Margarit Pavelescu
Keyword(s):  
Membrane Separation ◽  
Separation Efficiency ◽  
Liquid Radioactive Waste ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Suspended Solid ◽  
Process Efficiency ◽  
Active Charcoal ◽  
Precipitation Process ◽  
Pre Treatment

The paper presents the experimental tests concerning the treatment by membrane techniques of radioactive aqueous waste. Solutions, which have been treated by using the bench-scale installation, were radioactive simulated secondary wastes from the decontamination process with modified POD. Generally, an increasing of the retention is observed for most of the contaminants in the reverse osmosis experiments with pre-treatment steps. The main reason for taking a chemical treatment approach was to selectively remove soluble contaminants from the waste. In the optimization part of the precipitation step, several precipitation processes were compared. Based on this comparison, mixed [Fe(CN)6]4-/Al3+/Fe2+ was selected as a precipitation process applicable for precipitation of radionuclides and flocculation of suspended solid. Increased efficiencies for cesium radionuclides removal were obtained in natural zeolite adsorption pre-treatment stages and this was due to the fact that volcanic tuff used has a special affinity for this element. Usually, the addition of powdered active charcoal serves as an advanced purifying method used to remove organic compounds and residual radionuclides; thus by analyzing the experimental data (for POD wastes) one can observe a decreasing of about 50% for cobalt isotopes subsequently to the active charcoal adsorption.. The semipermeable membranes were used, which were prepared by the researchers from the Research Center for Macromolecular Materials and Membranes, Bucharest. The process efficiency was monitored by gamma spectrometry.

scholarly journals Experimental Evaluation of Airlift Performance for Vertical Pumping of Water in Underground Mines

2021 ◽  
Author(s):  
Parviz Enany ◽  
Oleksandr Shevchenko ◽  
Carsten Drebenstedt
Keyword(s):  
Water Flow ◽  
High Efficiency ◽  
Experimental Studies ◽  
Theoretical Models ◽  
Injection System ◽  
Experimental Investigations ◽  
Flow Mode ◽  
New Device ◽  
Riser Pipe ◽  
Airlift Pump

AbstractThis paper presents experimental studies on the optimization of air–water flow in an airlift pump. Airlift pumps use compressed gas to verticall transport liquids and slurries. Due to the lack of theoretical equations for designing and predicting flow regimes, experimental investigations must be carried out to find the best condition to operate an airlift pump at high efficiency. We used a new air injection system and different submergence ratios to evaluate the output of a simple pump for vertical displacement of water in an underground mine. The tests were carried out in a new device with 5.64 m height and 10.2 cm circular riser pipe. Three air-jacket pipes, at different gas flows in the range of 0.002–0.09 m3/s were investigated with eight submergence ratios. It was found that with the same air flow rate, the most efficient flow of water was achieved when an air jacket with 3 mm diameter holes was used with a submergence ratio between 0.6 and 0.75. In addition, a comparison of practical results with two theoretical models proposed by other investigators showed that neither was able to accurately predict airlift performance in air–water flow mode.

scholarly journals Emerging Lab-on-a-Chip Approaches for Liquid Biopsy in Lung Cancer: Status in CTCs and ctDNA Research and Clinical Validation

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2101
Author(s):  
Ângela Carvalho ◽  
Gabriela Ferreira ◽  
Duarte Seixas ◽  
Catarina Guimarães-Teixeira ◽  
Rui Henrique ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Liquid Biopsy ◽  
Residual Disease ◽  
Lab On A Chip ◽  
Microfluidic Devices ◽  
Early Recurrence ◽  
Circulating Tumor Dna ◽  
Clinical Validation ◽  
Liquid Biopsies ◽  
Lung Cancer Patients

Despite the intensive efforts dedicated to cancer diagnosis and treatment, lung cancer (LCa) remains the leading cause of cancer-related mortality, worldwide. The poor survival rate among lung cancer patients commonly results from diagnosis at late-stage, limitations in characterizing tumor heterogeneity and the lack of non-invasive tools for detection of residual disease and early recurrence. Henceforth, research on liquid biopsies has been increasingly devoted to overcoming these major limitations and improving management of LCa patients. Liquid biopsy is an emerging field that has evolved significantly in recent years due its minimally invasive nature and potential to assess various disease biomarkers. Several strategies for characterization of circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) have been developed. With the aim of standardizing diagnostic and follow-up practices, microfluidic devices have been introduced to improve biomarkers isolation efficiency and specificity. Nonetheless, implementation of lab-on-a-chip platforms in clinical practice may face some challenges, considering its recent application to liquid biopsies. In this review, recent advances and strategies for the use of liquid biopsies in LCa management are discussed, focusing on high-throughput microfluidic devices applied for CTCs and ctDNA isolation and detection, current clinical validation studies and potential clinical utility.

scholarly journals Pros and Cons of the Cannabinoid System in Cancer: Focus on Hematological Malignancies

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3866
Author(s):  
Natasha Irrera ◽  
Alessandra Bitto ◽  
Emanuela Sant’Antonio ◽  
Rita Lauro ◽  
Caterina Musolino ◽  
...  
Keyword(s):  
Cannabinoid Receptors ◽  
Hematological Malignancies ◽  
Antitumor Agents ◽  
Control Cell ◽  
Experimental Studies ◽  
Endocannabinoid System ◽  
Chemotherapeutic Agents ◽  
Cancer Cell Growth ◽  
Cell Functions ◽  
Novel Approach

The endocannabinoid system (ECS) is a composite cell-signaling system that allows endogenous cannabinoid ligands to control cell functions through the interaction with cannabinoid receptors. Modifications of the ECS might contribute to the pathogenesis of different diseases, including cancers. However, the use of these compounds as antitumor agents remains debatable. Pre-clinical experimental studies have shown that cannabinoids (CBs) might be effective for the treatment of hematological malignancies, such as leukemia and lymphoma. Specifically, CBs may activate programmed cell death mechanisms, thus blocking cancer cell growth, and may modulate both autophagy and angiogenesis. Therefore, CBs may have significant anti-tumor effects in hematologic diseases and may synergistically act with chemotherapeutic agents, possibly also reducing chemoresistance. Moreover, targeting ECS might be considered as a novel approach for the management of graft versus host disease, thus reducing some symptoms such as anorexia, cachexia, fatigue, anxiety, depression, and neuropathic pain. The aim of the present review is to collect the state of the art of CBs effects on hematological tumors, thus focusing on the essential topics that might be useful before moving into the clinical practice.

Hypoxic mechanisms in primary headaches

Cephalalgia ◽  
2016 ◽  
Vol 37 (4) ◽  
pp. 372-384 ◽  
Author(s):  
Josefine Britze ◽  
Nanna Arngrim ◽  
Henrik Winther Schytz ◽  
Messoud Ashina
Keyword(s):  
Cluster Headache ◽  
High Altitude ◽  
Acute Mountain Sickness ◽  
Experimental Studies ◽  
Epidemiological Studies ◽  
Primary Headaches ◽  
Secondary Headaches ◽  
Novel Approach ◽  
Calcitonin Gene ◽  
Level Of Knowledge

Background Hypoxia causes secondary headaches such as high-altitude headache (HAH) and headache due to acute mountain sickness. These secondary headaches mimic primary headaches such as migraine, which suggests a common link. We review and discuss the possible role of hypoxia in migraine and cluster headache. Methods This narrative review investigates the current level of knowledge on the relation of hypoxia in migraine and cluster headache based on epidemiological and experimental studies. Findings Epidemiological studies suggest that living in high-altitude areas increases the risk of migraine and especially migraine with aura. Human provocation models show that hypoxia provokes migraine with and without aura, whereas cluster headache has not been reliably induced by hypoxia. Possible pathophysiological mechanisms include hypoxia-induced release of nitric oxide and calcitonin gene-related peptide, cortical spreading depression and leakage of the blood-brain barrier. Conclusion There is a possible link between hypoxia and migraine and maybe cluster headache, but the exact mechanism is currently unknown. Provocation models of hypoxia have yielded interesting results suggesting a novel approach to study in depth the mechanism underlying hypoxia and primary headaches.

scholarly journals Hydrodynamics and heat exchange of crystal pulling from melts. Part I: Experimental studies of free convection mode

2019 ◽  
Vol 5 (3) ◽  
pp. 91-100
Author(s):  
Vladimir S. Berdnikov
Keyword(s):  
Heat Exchange ◽  
Convective Heat ◽  
Capillary Flow ◽  
Crystallization Front ◽  
Experimental Studies ◽  
Convective Heat Exchange ◽  
Czochralski Technique ◽  
Study Results ◽  
Front Shape ◽  
Prandtl Numbers

This work is a brief overview of experimental study results for hydrodynamics and convective heat exchange in thermal gravity capillary convection modes for the classic Czochralski technique setup obtained at the Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences. The experiments have been carried out at test benches which simulated the physics of the Czochralski technique for 80 and 295 mm diameter crucibles. Melt simulating fluids with Prandtl numbers Pr = 0.05, 16, 45.6 and 2700 have been used. Experiments with transparent fluids have been used for comparing the evolution of flow structure from laminar mode to well-developed turbulent mode. Advanced visualization and measurement methods have been used. The regularities of local and integral convective heat exchange in the crucible/melt/crystal system have been studied. The experiments have shown that there are threshold Grashof and Marangoni numbers at which the structure of the thermal gravity capillary flow undergoes qualitative changes and hence the regularities of heat exchange in the melt change. The effect of melt hydrodynamics on the crystallization front shape has been studied for Pr = 45.6. Crystallization front shapes have been determined for the 1 × 105 to 1.9 × 105 range of Grashof numbers. We show that the crystallization front shape depends largely on the spatial flow pattern and the temperature distribution in the melt.

scholarly journals Hydrodynamics of an in-pond raceway system with an aeration plug-flow device for application in aquaculture: an experimental study

2019 ◽  
Vol 6 (7) ◽  
pp. 182061 ◽  
Author(s):  
Wuhua Li ◽  
Xiangju Cheng ◽  
Jun Xie ◽  
Zhaoli Wang ◽  
Deguang Yu
Keyword(s):  
Water Flow ◽  
Plug Flow ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
High Water ◽  
Secondary Flows ◽  
Commercial Application ◽  
Flow Device ◽  
Intensive Aquaculture

An in-pond raceway system (IPRS) is an effective intensive aquaculture practice for regions with high water consumption and limited land resources. Water flow and dissolved oxygen (DO) are important for sustainable aquaculture. Several innovations have been made in IPRS design and operation to increase water exchange and DO concentration; one of these is the aeration plug-flow device (APFD). The APFD is commonly used in China as the only power source for water recirculation in aquaculture ponds. Understanding of the hydrodynamics of the system is necessary to improve the design of the IPRS with APFD. To this end, we performed experimental studies on a model system. We measured three-dimensional velocity at various locations using an Acoustic Doppler Velocimeter. Velocity distribution and turbulence characteristics were assessed, and plug-flow characteristics were analysed. Two patterns of velocity and turbulence in horizontal sections were observed: near the APFD, the water flow was intensively pushed downstream and simultaneously recirculated; farther away, the reflux area gradually decreased and the velocity and turbulence distribution trended towards uniform. Secondary flows occurred in different directions, which improved the diffusion of materials and DO retention. The system is effectively self-circulating, and the plug-flow capability may be scaled up for commercial application.

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