scholarly journals Analytical Guidelines for Designing Curvature-Induced Dielectrophoretic Particle Manipulation Systems

Micromachines ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 707
Author(s):  
Akshay Kale ◽  
Amirreza Malekanfard ◽  
Xiangchun Xuan
Keyword(s):  
Electrical Energy ◽  
Label Free ◽  
Particle Manipulation ◽  
Established Method ◽  
Circular Arc ◽  
Chip Area ◽  
Starting Point ◽  
Design For Safety ◽  
Detailed Mathematical Analysis ◽  
Simple Equations

Curvature-induced dielectrophoresis (C-iDEP) is an established method of applying electrical energy gradients across curved microchannels to obtain a label-free manipulation of particles and cells. This method offers several advantages over the other DEP-based methods, such as increased chip area utilisation, simple fabrication, reduced susceptibility to Joule heating and reduced risk of electrolysis in the active region. Although C-iDEP systems have been extensively demonstrated to achieve focusing and separation of particles, a detailed mathematical analysis of the particle dynamics has not been reported yet. This work computationally confirms a fully analytical dimensionless study of the electric field-induced particle motion inside a circular arc microchannel, the simplest design of a C-iDEP system. Specifically, the analysis reveals that the design of a circular arc microchannel geometry for manipulating particles using an applied voltage is fully determined by three dimensionless parameters. Simple equations are established and numerically confirmed to predict the mutual relationships of the parameters for a comprehensive range of their practically relevant values, while ensuring design for safety. This work aims to serve as a starting point for microfluidics engineers and researchers to have a simple calculator-based guideline to develop C-iDEP particle manipulation systems specific to their applications.

scholarly journals Recent Advances in Continuous-Flow Particle Manipulations Using Magnetic Fluids

Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 744 ◽  
Author(s):  
Xiangchun Xuan
Keyword(s):  
Continuous Flow ◽  
Lab On A Chip ◽  
Microfluidic Devices ◽  
Magnetic Fluids ◽  
Label Free ◽  
Particle Manipulation ◽  
The Past ◽  
Recent Advances ◽  
Medium Exchange ◽  
Flow Particle

Magnetic field-induced particle manipulation is simple and economic as compared to other techniques (e.g., electric, acoustic, and optical) for lab-on-a-chip applications. However, traditional magnetic controls require the particles to be manipulated being magnetizable, which renders it necessary to magnetically label particles that are almost exclusively diamagnetic in nature. In the past decade, magnetic fluids including paramagnetic solutions and ferrofluids have been increasingly used in microfluidic devices to implement label-free manipulations of various types of particles (both synthetic and biological). We review herein the recent advances in this field with focus upon the continuous-flow particle manipulations. Specifically, we review the reported studies on the negative magnetophoresis-induced deflection, focusing, enrichment, separation, and medium exchange of diamagnetic particles in the continuous flow of magnetic fluids through microchannels.

scholarly journals Sizing Milking Groups in Small Cow Dairies of Mediterranean Countries

Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 795
Author(s):  
Angela Calvo ◽  
Gianfranco Airoldi
Keyword(s):  
Dairy Farms ◽  
Herd Size ◽  
Entry And Exit ◽  
Dairy Farmer ◽  
Mediterranean Countries ◽  
Starting Point ◽  
Work Routine ◽  
Simple Equations ◽  
Piedmont Region

A dairy farmer chooses the number of milking groups in function of the herd size, stall type and milking system also in small cow dairies (number of animals lower than 100–120). In these dairies, there are different milking systems (bucket, trolley, pipeline, little autotandem, herringbone or parallel parlors) and each of them has a different work routine. The knowledge of the routine is the starting point for assessing the milking installation, because it determines the number of milked cows per hour. Different milking systems have common tasks (as pre-dipping, inspecting foremilk, udder preparation, attaching teat cups, post-dipping), but in the meantime there are different operations that characterize each specific routine (e.g., animal entry and exit if there is a parlor, bucket, trolley or milking group positioning if tie-stall). For this reason, we surveyed twenty small dairy farms located in the Piedmont Region (Italy) with different milking systems to correctly acquire the specific milking routines. Different models were therefore studied using the observed routines in in the examined farms. These models were then used to calculate the number of milked cows per hour and the number of milking groups. The main findings were simple equations, specific for each milking system, easily accessible by the farmer to correctly size his milking system.

scholarly journals Gestión ambiental en el sector público de Costa Rica: indicadores de referencia para aspectos ambientales comunes

2014 ◽  
Vol 6 (2) ◽  
pp. 253-260
Author(s):  
Marco Vinicio Chinchilla S
Keyword(s):  
Environmental Management ◽  
Public Sector ◽  
Electrical Energy ◽  
Environmental Indicators ◽  
Costa Rican ◽  
Environmental Aspects ◽  
Future Studies ◽  
Starting Point ◽  
Institutional Sector ◽  
Carbon Dioxide Equivalent

Environmental management in the Costa Rican public sector: baseline indicators for common environmental aspects. Since 2011 the Costa Rican public sector has been mandated to develop environmental management programs for the reduction of negative environmental impacts (MINAE-S Executive Decree 36499). Some environmental aspects are common to most institutions: water, paper, electricity and fuel consumption, and generation of Greenhouse Gases (GHG). Here I present common environmental indicators to serve as a baseline to assess effectiveness in the sector over time. I analyzed consumption records delivered by the institutions to the Ministry of Environment and Energy. I found the following consumption indicators: a) 2,76m3 of water/employee/month; (b) 411,5 sheets/employee/month; (c) 206,78kWh/employee/month; (d) 8,03kWh/m2 month; (e) 20,29L of fuel per employee/month. For the generation of carbon dioxide equivalent, the following estimates were used: 17,04kg of CO2e/employee/month for electrical energy consumption; (b) 53,07kg of CO2e/employee/month for consumption of fuel by transport vehicles. No significant differences were found between the ministries and decentralized public institutional sector; with the exception of the consumption of electricity by area (Test t-student; t=-2,731; p=0,009), where the highest value was observed in the decentralized public institutional sector (11,06kWh/m2/month). This results represent the starting point for future studies to analyze the effectiveness of environmental management in the Costa Rican public sector.

scholarly journals Numerical and experimental analysis of a hybrid material acoustophoretic device for manipulation of microparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alireza Barani ◽  
Peiman Mosaddegh ◽  
Shaghayegh Haghjooy Javanmard ◽  
Shahrokh Sepehrirahnama ◽  
Amir Sanati-Nezhad
Keyword(s):  
Temperature Rise ◽  
Hybrid Material ◽  
Nodal Line ◽  
Microfluidic Chips ◽  
Label Free ◽  
Particle Manipulation ◽  
Nodal Plane ◽  
Widespread Application ◽  
New Device ◽  
Hard Materials

AbstractAcoustophoretic microfluidic devices have been developed for accurate, label-free, contactless, and non-invasive manipulation of bioparticles in different biofluids. However, their widespread application is limited due to the need for the use of high quality microchannels made of materials with high specific acoustic impedances relative to the fluid (e.g., silicon or glass with small damping coefficient), manufactured by complex and expensive microfabrication processes. Soft polymers with a lower fabrication cost have been introduced to address the challenges of silicon- or glass-based acoustophoretic microfluidic systems. However, due to their small acoustic impedance, their efficacy for particle manipulation is shown to be limited. Here, we developed a new acoustophoretic microfluid system fabricated by a hybrid sound-hard (aluminum) and sound-soft (polydimethylsiloxane polymer) material. The performance of this hybrid device for manipulation of bead particles and cells was compared to the acoustophoretic devices made of acoustically hard materials. The results show that particles and cells in the hybrid material microchannel travel to a nodal plane with a much smaller energy density than conventional acoustic-hard devices but greater than polymeric microfluidic chips. Against conventional acoustic-hard chips, the nodal line in the hybrid microchannel could be easily tuned to be placed in an off-center position by changing the frequency, effective for particle separation from a host fluid in parallel flow stream models. It is also shown that the hybrid acoustophoretic device deals with smaller temperature rise which is safer for the actuation of bioparticles. This new device eliminates the limitations of each sound-soft and sound-hard materials in terms of cost, adjusting the position of nodal plane, temperature rise, fragility, production cost and disposability, making it desirable for developing the next generation of economically viable acoustophoretic products for ultrasound particle manipulation in bioengineering applications.

scholarly journals The Influence of Electric-Arc-Furnace Input Feeds on its Electrical Energy Consumption

2021 ◽  
Author(s):  
Vito Logar ◽  
Igor Škrjanc
Keyword(s):  
Energy Consumption ◽  
Electrical Energy ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Furnace Operation ◽  
Arc Furnace ◽  
Electrical Energy Consumption ◽  
Arc Furnaces ◽  
Starting Point ◽  
Oxygen Ratio

AbstractOperation of the electric arc furnaces (EAFs) is a subject to consider fluctuations in terms of its key performance indicators, such as the electrical energy consumption (EEC), tap-to-tap time, steel yield, and others. In this paper, a more detailed analysis of the electric arc furnace data is performed, investigating its EEC. It is well known that the EEC is affected by the weight and the type of charged scrap, the operational delays, and the tapping temperature. On the other hand, one can also deduce that the feeds, such as the carbon and the oxygen, could also affect the EEC, due to their role in redox equations and impact to the bath energy balance. Therefore, special attention is devoted to the analysis of the carbon-to-oxygen ratio during the electric arc furnace operation and the consequent influence of the oxygen availability on the EEC. Statistical analysis of more than 2500 heats of data, which were clustered according to the produced steel grade and the charged scrap mixture, has revealed that besides the beforementioned factors, fluctuations in EEC could appear also due to different amounts of added carbon and oxygen. Since the furnace operators usually rely on predefined guidelines and their own experience when actuating the furnace, a simplistic statistical approach can be used to reveal some of the weaknesses in the control routines, which can be used as a starting point to improve their actuation, leading to decreased energy consumption. Graphical Abstract

scholarly journals Ultrasonic Based Tissue Modelling and Engineering

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 594 ◽  
Author(s):  
Karl Olofsson ◽  
Björn Hammarström ◽  
Martin Wiklund
Keyword(s):  
Explant Culture ◽  
Cell Manipulation ◽  
Label Free ◽  
Particle Manipulation ◽  
Tissue Organization ◽  
Ultrasonic Standing Wave ◽  
Tissue Modelling

Systems and devices for in vitro tissue modelling and engineering are valuable tools, which combine the strength between the controlled laboratory environment and the complex tissue organization and environment in vivo. Device-based tissue engineering is also a possible avenue for future explant culture in regenerative medicine. The most fundamental requirements on platforms intended for tissue modelling and engineering are their ability to shape and maintain cell aggregates over long-term culture. An emerging technology for tissue shaping and culture is ultrasonic standing wave (USW) particle manipulation, which offers label-free and gentle positioning and aggregation of cells. The pressure nodes defined by the USW, where cells are trapped in most cases, are stable over time and can be both static and dynamic depending on actuation schemes. In this review article, we highlight the potential of USW cell manipulation as a tool for tissue modelling and engineering.

scholarly journals PROTOTYPE GROUNDING DETECTOR PADA GROUND CLUSTER DENGAN SISTEM INTERLOCKPADALBS (LOAD BREAK SWITCH) BERBASIS ARDUINO MEGA 2560 DENGAN TAMPILAN HMI (HUMAN MACHINE INTERFACE)

2018 ◽  
Vol 19 (4) ◽  
pp. 15
Author(s):  
Bambang Handoko Pasaribu ◽  
Iman Setiono
Keyword(s):  
Social Economic ◽  
Electrical Energy ◽  
Human Machine Interface ◽  
The State ◽  
Voltage Sensor ◽  
Starting Point ◽  
Machine Interface ◽  
Work Accidents ◽  
Three Phases

Electricity has become a daily necessity in the community both social, economic and business. Therefore electricity is needed every day and it is the reliability of PLN. To fulfill such reliability While the reliability of electrical energy should be followed by inspection on the equipment used. PLN field employees themselves who every day always do inspection on the network of all the repeaters, so that field officers always know the state of the network in the field. If the network looks bad or requires maintenance it will be scheduled to do the job. Before the holding of the work it will be done in the first outage area is to operate the switching tool didaerah area. The switching tools are ABSW and LBS. After all the swithing tools are operated the workers always do the grounding first on the three phases by using ground clusters at the starting point to the end of the work where if transmitted so called PMS ground. This is done as a safety because the LBS switching tool is closed so that workers are not sure if the network has been extinguished and as a safety if LBS failed to work or failure. But here the worker himself sometimes still not sure whether the ground cluster is already installed properly or not. And as a safeguard against the occurrence of any maneuvering done by employees from the office Rayon. Therefore the author wants to make a prototype to detect whether grounding is installed properly or not in every phase. The prototype uses Arduino mega as its micron and uses a voltage sensor to find out the value of the voltage. If the ground claster is installed and work fails on LBS then the OCR relay will work and PMT will trip. With the prototype is expected to improve security in the work and minimize the occurrence of work accidents. This prototype has a 0% chance of a crash if the ground cluster is properly installed. Keywords: Arduino Mega, Ground Detector, OCR relay, Voltage Sensor. 

scholarly journals A coupled technological-sociological model for national electrical energy supply systems including sustainability

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Manfred Benthaus
Keyword(s):  
Energy Supply ◽  
Electrical Potential ◽  
Solution Space ◽  
Electrical Energy ◽  
Economic Loss ◽  
User Requirements ◽  
Global Trends ◽  
Starting Point ◽  
Supply Systems ◽  
Energy Supply Systems

AbstractGlobal trends in the development and use of electricity utilities and assets are practically irreversible. In industrialized nations, capacity factors have grown so large that users may expect freely available electrical potential energy at all times and in almost all locations. Economically capitalizing on this trend means maximizing energy provision and use to boost gross domestic product growth rates. Electricity is now a basic indicator of social development; it is to the cultural-technological dimension what breathing air is to the physiological-biological dimension, the implication being that sustainable development of provision systems has become a matter of international concern.This article presents a decision basis for the design of sustainable national electrical energy supply systems, incorporating country-specific boundary conditions in the form of user requirements to be specified by users. The basis is a solution space of technologically possible systems, obtained by combining generalized user requirements and physical limitations to generate the solution states. As all technological options for the system are brought under consideration, this approach represents a comprehensive comparative analysis.The decision process ensues by assigning to each solution state a set of (newly defined) system risk factors. Particular consideration is given to evaluating the system’s ability to meet the user requirements, i.e., interruption-free provision. The central benchmark is the technological-economic availability. From this is obtained a sustainability boundary, the boundary between quantifiable and unquantifiable economic loss potentials.This article deliberately avoids referencing specific technological solutions, with the justification that the basis of the user’s decision should be independent of technological considerations. The sole exception is a reference to the currently used technology, which forms the starting point.

scholarly journals Integrated use of LC/MS/MS and LC/Q-TOF/MS targeted metabolomics with automated label-free microscopy for quantification of purine metabolites in cultured mammalian cells

2018 ◽  
Author(s):  
S. Eric Nybo ◽  
Jennifer T. Lamberts
Keyword(s):  
Biological Samples ◽  
Mammalian Cells ◽  
Fluorescent Dyes ◽  
Neuroblastoma Cells ◽  
Digital Microscopy ◽  
Label Free ◽  
Targeted Metabolomics ◽  
Established Method ◽  
Purine Metabolites ◽  
Metabolomics Analysis

AbstractPurine metabolites have been implicated as clinically relevant biomarkers of worsening or improving Parkinson’s disease (PD) progression. However, the identification of purine molecules as biomarkers in PD has largely been determined using non-targeted metabolomics analysis. The primary goal of this study was to develop an economical targeted metabolomics approach for the routine detection of purine molecules in biological samples. Specifically, this project utilized LC/MS/MS and LC/QTOF/MS to accurately quantify levels of six purine molecules in samples from cultured N2a murine neuroblastoma cells. The targeted metabolomics workflow was integrated with automated label-free digital microscopy, which enabled normalization of purine concentration per unit cell in the absence of fluorescent dyes. The established method offered significantly enhanced selectivity compared to previously published procedures. In addition, this study demonstrates that a simple, quantitative targeted metabolomics approach can be developed to identify and quantify purine metabolites in biological samples. We envision that this method could be broadly applicable to quantification of purine metabolites from other complex biological samples, such as cerebrospinal fluid or blood.

scholarly journals Ultrasonic Particle Manipulation in Glass Capillaries: A Concise Review

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 876
Author(s):  
Guotian Liu ◽  
Junjun Lei ◽  
Feng Cheng ◽  
Kemin Li ◽  
Xuanrong Ji ◽  
...  
Keyword(s):  
Cross Sections ◽  
Ultrasonic Waves ◽  
Submicron Particles ◽  
Label Free ◽  
Particle Manipulation ◽  
Glass Capillary ◽  
Ultrasonic Particle Manipulation ◽  
Glass Capillaries ◽  
Acoustic Tweezers ◽  
Underlying Mechanisms

Ultrasonic particle manipulation (UPM), a non-contact and label-free method that uses ultrasonic waves to manipulate micro- or nano-scale particles, has recently gained significant attention in the microfluidics community. Moreover, glass is optically transparent and has dimensional stability, distinct acoustic impedance to water and a high acoustic quality factor, making it an excellent material for constructing chambers for ultrasonic resonators. Over the past several decades, glass capillaries are increasingly designed for a variety of UPMs, e.g., patterning, focusing, trapping and transporting of micron or submicron particles. Herein, we review established and emerging glass capillary-transducer devices, describing their underlying mechanisms of operation, with special emphasis on the application of glass capillaries with fluid channels of various cross-sections (i.e., rectangular, square and circular) on UPM. We believe that this review will provide a superior guidance for the design of glass capillary-based UPM devices for acoustic tweezers-based research.

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