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.

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 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.

Supported Bilayer Membranes for Reducing Cell Adhesion in Microfluidic Devices

2021 ◽  
Author(s):  
Julia R Clapis ◽  
Mengqi Jonathan Fan ◽  
Michelle L Kovarik
Keyword(s):  
Cell Adhesion ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Microfluidic Devices ◽  
Microfluidic Channels ◽  
Bilayer Membranes ◽  
Supported Bilayer

The high surface area-to-volume ratio of microfluidic channels makes them susceptible to fouling and clogging when used for biological analyses,including cell-based assays. We evaluated the role of electrostatic and van...

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.

scholarly journals Study of Sexual Dimorphism in Metatarsal Bones: Geometric and Inertial Analysis of the Three-Dimensional Reconstructed Models

2021 ◽  
Vol 12 ◽  
Author(s):  
Yaming Liu ◽  
Djorde Antonijević ◽  
Ruining Li ◽  
Yuxuan Fan ◽  
Ksenija Dukić ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Surface Area ◽  
Three Dimensional ◽  
Volume Ratio ◽  
Discriminant Functions ◽  
Moments Of Inertia ◽  
Principal Moments Of Inertia ◽  
Metatarsal Bones ◽  
The Individual ◽  
Bone Height

The aim of the present paper is to determine the sex of the individual using three-dimensional geometric and inertial analyses of metatarsal bones. Metatarsals of 60 adult Chinese subjects of both sexes were scanned using Aquilion One 320 Slice CT Scanner. The three-dimensional models of the metatarsals were reconstructed, and thereafter, a novel software using the center of mass set as the origin and the three principal axes of inertia was employed for model alignment. Eight geometric and inertial variables were assessed: the bone length, bone width, bone height, surface-area-to-volume ratio, bone density, and principal moments of inertia around the x, y, and z axes. Furthermore, the discriminant functions were established using stepwise discriminant function analysis. A cross-validation procedure was performed to evaluate the discriminant accuracy of functions. The results indicated that inertial variables exhibit significant sexual dimorphism, especially principal moments of inertia around the z axis. The highest dimorphic values were found in the surface-area-to-volume ratio, principal moments of inertia around the z axis, and bone height. The accuracy rate of the discriminant functions for sex determination ranged from 88.3% to 98.3% (88.3%–98.3% cross-validated). The highest accuracy of function was established based on the third metatarsal bone. This study showed for the first time that the principal moment of inertia of the human bone may be successfully implemented for sex estimation. In conclusion, the sex of the individual can be accurately estimated using a combination of geometric and inertial variables of the metatarsal bones. The accuracy should be further confirmed in a larger sample size and be tested or independently developed for distinct population/age groups before the functions are widely applied in unidentified skeletons in forensic and bioarcheological contexts.

scholarly journals Morphometry of ventral hippocampal neurons of CA1-CA4 fields in domestic cattle

2016 ◽  
Vol 72 (12) ◽  
pp. 773-776
Author(s):  
Iwona Łuszczewska-Sierakowska ◽  
Agata Wawrzyniak ◽  
Anna Charuta ◽  
Marcin R. Tatara ◽  
Mariusz Klepacki ◽  
...  
Keyword(s):  
Surface Area ◽  
Cell Nucleus ◽  
Morphometric Analysis ◽  
Hippocampal Neurons ◽  
Bos Taurus ◽  
Average Diameter ◽  
Novel Approach ◽  
Pyramidal Layer ◽  
The Central Nervous System ◽  
The Individual

The aim of the study was a morphometric analysis of the ventral hippocampal neurons of the individual CA1-CA4 fields in domestic cattle (Bos Taurus; N = 6). The hippocampus in cattle is formed by a sizable arched invagination of the medial wall of the lateral ventricle of the brain. The brains were removed and analyzed conventionally with a light microscope. The samples were stained by Nissl’s method. The morphometric analysis of the neurons of the hippocampal CA1-CA4 fields included the following parameters: the area of nervous cells and the area of the cell nucleus in μm2; the nucleus-to-cell ratio in %; the average diameter and perimeter of the nervous cell in μm. The morphometric investigations indicate that the cells of the pyramidal layer in the CA1-CA4 fields of the hippocampus in adult domestic cattle differ in terms of their size, shape, and surface area, as well as the surface area of the cell nucleus. The size of cells in CA1 was the largest, fluctuating around 22 μm, whereas in CA4 it amounted to about 19 μm. Cells in CA1 and CA2 had the largest diameter of about 24 µm, whereas cells in the CA4 field had the smallest diameter of about 20 µm. The results obtained suggest a novel approach to studying the morphometric properties of the hippocampus in domestic cattle. Morphometric studies of the central nervous system (CNS) are regarded as a valuable source of data on the function of environmental and pharmacological factors and their effects on several structures of the CNS.

Evaluation of Nanotechniques and Conventional Techniques for the Removal of Dioxins

2018 ◽  
Vol 9 (1) ◽  
pp. 79-84
Author(s):  
Vaishali V. Shahare ◽  
Rajni Grover ◽  
Suman Meena
Keyword(s):  
Soil Sample ◽  
Human Health ◽  
Surface Area ◽  
Contaminated Soil ◽  
Conventional Treatment ◽  
Volume Ratio ◽  
Soil Samples ◽  
Dioxins And Furans ◽  
Palladized Iron ◽  
The Impact

Background: The persistent dioxins/furans has caused a worldwide concern as they influence the human health. Recent research indicates that nonmaterial may prove effective in the degradation of Dioxins/furans. The nanomaterials are very reactive owing to their large surface area to volume ratio and large number of reactive sites. However, nanotechnology applications face both the challenges and the opportunities to influence the area of environmental protection. Objective: i) To study the impact of oil mediated UV-irradiations on the removal of 2,3,7,8-TCDD, 2,3,7,8-TCDF, OCDD and OCDF in simulated soil samples. ii) To compare the conventional treatment methods with the modern available nanotechniques for the removal of selected Dioxins/furans from soil samples. Methods: The present work has investigated an opportunity of the degradation of tetra and octachlorinated dioxins and furans by using oil mediated UV radiations with subsequent extraction of respective dioxins/furans from soils. The results have been compared with the available nanotechniques. Results: The dioxin congeners in the simulated soil sample showed decrease in concentration with the increase in the exposure time and intensity of UV radiations. The dechlorination of PCDD/Fs using palladized iron has been found to be effective. Conclusion: Both the conventional methods and nanotechnology have a dramatic impact on the removal of Dioxins/furans in contaminated soil. However, the nanotechniques are comparatively costlier and despite the relatively high rates of PCDDs dechlorination by Pd/nFe, small fraction of the dioxins are recalcitrant to degradation over considerable exposure times.

Using hidden Markov models to find discrete targets in continuous sociophonetic data

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Daniel Duncan
Keyword(s):  
Hidden Markov Models ◽  
Markov Models ◽  
Hidden Markov ◽  
Abstract Representation ◽  
Language Variation And Change ◽  
Novel Approach ◽  
Single Target ◽  
The Individual ◽  
Individual Speaker

Abstract Advances in sociophonetic research resulted in features once sorted into discrete bins now being measured continuously. This has implied a shift in what sociolinguists view as the abstract representation of the sociolinguistic variable. When measured discretely, variation is variation in selection: one variant is selected for production, and factors influencing language variation and change are influencing the frequency at which variants are selected. Measured continuously, variation is variation in execution: speakers have a single target for production, which they approximate with varying success. This paper suggests that both approaches can and should be considered in sociophonetic analysis. To that end, I offer the use of hidden Markov models (HMMs) as a novel approach to find speakers’ multiple targets within continuous data. Using the lot vowel among whites in Greater St. Louis as a case study, I compare 2-state and 1-state HMMs constructed at the individual speaker level. Ten of fifty-two speakers’ production is shown to involve the regular use of distinct fronted and backed variants of the vowel. This finding illustrates HMMs’ capacity to allow us to consider variation as both variant selection and execution, making them a useful tool in the analysis of sociophonetic data.

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