Electrowetting on dielectric: experimental and model study of oil conductivity on rupture voltage

NASA Astrophysics Data System (ADS)

Zhao, Qing; Tang, Biao; Dong, Baoqin; Li, Hui; Zhou, Rui; Guo, Yuanyuan; Dou, Yingying; Deng, Yong; Groenewold, Jan; Henzen, Alexander Victor; Zhou, Guofu

2018-05-01

Electrowetting on dielectric devices uses a conducting (water) and insulating (oil) liquid phase in conjunction on a dielectric layer. In these devices, the wetting properties of the liquid phases can be manipulated by applying an electric field. The electric field can rupture the initially flat oil film and promotes further dewetting of the oil. Here, we investigate a problem in the operation of electrowetting on dielectric caused by a finite conductivity of the oil. In particular, we find that the voltage at which the oil film ruptures is sensitive to the application of relatively low DC voltages prior to switching. Here, we systematically investigate this dependence using controlled driving schemes. The mechanism behind these history effects point to charge transport processes in the dielectric and the oil, which can be modeled and characterized by a decay time. To quantify the effects the typical response timescales have been measured with a high-speed video camera. The results have been reproduced in simulations. In addition, a simplified yet accurate equivalent circuit model is developed to analyze larger data sets more conveniently. The experimental data support the hypothesis that each pixel can be characterized by a single decay time. We studied an ensemble of pixels and found that they showed a rather broad distribution of decay times with an average value of about 440 ms. This decay time can be interpreted as a discharge timescale of the oil, not to be confused with discharge of the entire system which is generally much faster (<1 ms). Through the equivalent circuit model, we also found that variations in the fluoropolymer (FP) conductivity cannot explain the distribution of decay times, while variations in oil conductivity can.

Effect of driving voltage polarity on dynamic response characteristics of electrowetting liquid lens

NASA Astrophysics Data System (ADS)

Na, Xie; Ning, Zhang; Rong-Qing, Xu

2018-05-01

A test device is developed for studying the dynamic process of an electrowetting liquid lens. By analyzing the light signals through the liquid lens, the dynamical properties of the lens are investigated. In our experiment, three types of pulse, i.e., sine, bipolar pulse, and single pulse signals, are employed to drive the liquid lens, and the dynamic characteristics of the lens are subsequently analyzed. The results show that the positive and negative polarities of the driving voltage can cause a significant difference in the response of the liquid lens; meanwhile, the lens’s response to the negative polarity of the driving voltage is clearer. We use the theory of charge restraint to explain this phenomenon, and it is concluded that the negative ions are more easily restrained by a dielectric layer. This work gives direct guidance for practical applications based on an electrowetting liquid lens.

Fluidic conduits for highly efficient purification of target species in EWOD-driven droplet microfluidics.

PubMed

Shah, Gaurav J; Kim, Chang-Jin Cj

2009-08-21

Due to the lack of continuous flows that would wash unwanted specifies and impurities off from a target location, droplet microfluidics commonly employs a long serial dilution process to purify target species. In this work, we achieve high-purity separation for the case of electrowetting-on-dielectric (EWOD) based droplet microfluidics by introducing a "fluidic conduit" between a sample droplet and a buffer droplet. The long and slender fluidic path minimizes the diffusion and fluidic mixing between the two droplets (thus eliminating non-specific transport) but provides a conduit between them for actively transported particles (thus allowing the specific transport). The conduit is purely fluidic, stabilized chemically (e.g. using surfactants) and controlled by EWOD. The effectiveness of the technique is demonstrated by eliminating approximately 97% non-magnetic beads in just one purification step, while maintaining high collection efficiency (>99%) of magnetic beads.

Frequency Dependence of Low-Voltage Electrowetting Investigated by Impedance Spectroscopy.

PubMed

Li, Ying-Jia; Cahill, Brian P

2017-11-14

An electrowetting-on-dielectric (EWOD) electrode was developed that facilitates the use of low alternating voltages (≤5 V AC ). This allows online investigation of the frequency dependence of electrowetting by means of impedance spectroscopy. The EWOD electrode is based on a dielectric bilayer consisting of an anodic tantalum pentoxide (Ta 2 O 5 ) thin film (d = 59.35 nm) with a high relative permittivity (ε d = 26.3) and a self-assembled hydrophobic silane monolayer. The frequency dependence of electrowetting was studied using an aqueous μL-sized sessile droplet on the planar EWOD electrode in oil. Experiments using electrochemical impedance spectroscopy and optical imaging indicate the frequency dependence of all three variables in the Young-Lippmann equation: the voltage drop across the dielectric layers, capacitance per unit area, and contact angle under voltage. The electrowetting behavior induced by AC voltages is shown to be well described by the Young-Lippmann equation for AC applications below a frequency threshold. Moreover, the dielectric layers act as a capacitor and the stored electrostatic potential energy is revealed to only partially contribute to the electrowetting.

Electrowetting-driven variable-focus microlens on flexible surfaces

NASA Astrophysics Data System (ADS)

Li, Chenhui; Jiang, Hongrui

2012-06-01

We demonstrate a flexible, electrowetting-driven, variable-focus liquid microlens. The microlens is fabricated using a soft polymer polydimethylsiloxane. The lens can be smoothly wrapped onto a curved surface. A low-temperature fabrication process was developed to reduce the stress on and to avoid any damage to the polymer. The focal length of the microlens varies between -15.0 mm to +28.0 mm, depending on the applied voltage. The resolving power of the microlens is 25.39 line pairs per mm using a 1951 United States Air Force resolution chart. The typical response time of the lens is around 50 ms.

Durability Enhancement of a Microelectromechanical System-Based Liquid Droplet Lens

NASA Astrophysics Data System (ADS)

Kyoo Lee, June; Park, Kyung-Woo; Kim, Hak-Rin; Kong, Seong Ho

2010-06-01

In this paper, we propose methods to enhance the durability of a microelectromechanical system (MEMS)-based liquid droplet lens driven by electrowetting. The enhanced durability of the lens is achieved through not only improvement in quality of dielectric layer for electrowetting by minimizing concentration of coarse pinholes, but also mitigation of physical and electrostatic stresses by reforming lens cavity. Silicon dioxide layer is deposited using plasma enhanced chemical vapor deposition, splitting the process into several steps to minimize the pinhole concentration in the oxide layer. And the stresses-reduced cavity in a form of overturned tetra-angular truncated pyramid with rounded corners, which is based on simulated results, is proposed and realized using silicon wet etching processes combined into anisotropic and isotropic etching.

Advanced characterization of electrowetting retroreflectors.

PubMed

Kilaru, Murali K; Yang, Jia; Heikenfeld, Jason

2009-09-28

Electrowetting retroreflectors use a simple and scalable construction, and incorporate an electrically tunable liquid lenslet. By electrically modulating the lenslet geometry, the reflection is switched between retroreflection and scattering. In this paper, we report new capability and characterization, including higher index liquids and contrast ratio as a function of contact angle (theta(V)). The reflected intensity is also spatially profiled and reported as a function of view angle. A high contrast ratio of >16X is demonstrated, and methods for further improving performance are discussed. Because the electrowetting retroreflector platform is broad spectrum (VIS-IR), the electrowetting retroreflector may be useful for a large variety of naked eye applications such as safety markings, road-signage, or friend-foe-identification.

Electrowetting-driven variable-focus microlens on flexible surfaces.

PubMed

Li, Chenhui; Jiang, Hongrui

2012-06-04

We demonstrate a flexible, electrowetting-driven, variable-focus liquid microlens. The microlens is fabricated using a soft polymer polydimethylsiloxane. The lens can be smoothly wrapped onto a curved surface. A low-temperature fabrication process was developed to reduce the stress on and to avoid any damage to the polymer. The focal length of the microlens varies between -15.0 mm to +28.0 mm, depending on the applied voltage. The resolving power of the microlens is 25.39 line pairs per mm using a 1951 United States Air Force resolution chart. The typical response time of the lens is around 50 ms.

Electrowetting-driven variable-focus microlens on flexible surfaces

PubMed Central

Li, Chenhui; Jiang, Hongrui

2012-01-01

We demonstrate a flexible, electrowetting-driven, variable-focus liquid microlens. The microlens is fabricated using a soft polymer polydimethylsiloxane. The lens can be smoothly wrapped onto a curved surface. A low-temperature fabrication process was developed to reduce the stress on and to avoid any damage to the polymer. The focal length of the microlens varies between −15.0 mm to +28.0 mm, depending on the applied voltage. The resolving power of the microlens is 25.39 line pairs per mm using a 1951 United States Air Force resolution chart. The typical response time of the lens is around 50 ms. PMID:22904571

CrossTalk: The Journal of Defense Software Engineering. Volume 19, Number 2

DTIC Science & Technology

2006-02-01

dielectric film between hydrophobic and hydrophilic states to shape liquid into an optical lens . Wait, there’s more. Electrowetting (you’re still...I’ll have a Double-Layer Super Twist Nematic Latte, pronto. My favorite technical word is Electrowetting . I am not kidding. This is a legitimate...word and is a promising technolo- gy for optical switching networks and focusing lasers. Electrowetting (stop giggling) uses electrical fields to modify

Electrowetting on a lotus leaf

PubMed Central

Feng, Jiang-Tao; Wang, Feng-Chao; Zhao, Ya-Pu

2009-01-01

Electrowetting on dielectrics has been widely used to manipulate and control microliter or nanoliter liquids in micro-total-analysis systems and laboratory on a chip. We carried out experiments on electrowetting on a lotus leaf, which is quite different from the equipotential plate used in conventional electrowetting. This has not been reported in the past. The lotus leaf is superhydrophobic and a weak conductor, so the droplet can be easily actuated on it through electrical potential gradient. The capillary motion of the droplet was recorded by a high-speed camera. The droplet moved toward the counterelectrode to fulfill the actuation. The actuation speed could be of the order of 10 mm∕s. The actuation time is of the order of 10 ms. PMID:19693341

Electrowetting-based adaptive vari-focal liquid lens array for 3D display

NASA Astrophysics Data System (ADS)

Won, Yong Hyub

2014-10-01

Electrowetting is a phenomenon that can control the surface tension of liquid when a voltage is applied. This paper introduces the fabrication method of liquid lens array by the electrowetting phenomenon. The fabricated 23 by 23 lens array has 1mm diameter size with 1.6 mm interval distance between adjacent lenses. The diopter of each lens was - 24~27 operated at 0V to 50V. The lens array chamber fabricated by Deep Reactive-Ion Etching (DRIE) is deposited with IZO and parylene C and tantalum oxide. To prevent water penetration and achieve high dielectric constant, parylene C and tantalum oxide (ɛ = 23 ~ 25) are used respectively. Hydrophobic surface which enables the range of contact angle from 60 to 160 degree is coated to maximize the effect of electrowetting causing wide band of dioptric power. Liquid is injected into each lens chamber by two different ways. First way was self water-oil dosing that uses cosolvent and diffusion effect, while the second way was micro-syringe by the hydrophobic surface properties. To complete the whole process of the lens array fabrication, underwater sealing was performed using UV adhesive that does not dissolve in water. The transient time for changing from concave to convex lens was measured <33ms (at frequency of 1kHz AC voltage.). The liquid lens array was tested unprecedentedly for integral imaging to achieve more advanced depth information of 3D image.

Thin-film-transistor array: an exploratory attempt for high throughput cell manipulation using electrowetting principle

NASA Astrophysics Data System (ADS)

Shaik, F. Azam; Cathcart, G.; Ihida, S.; Lereau-Bernier, M.; Leclerc, E.; Sakai, Y.; Toshiyoshi, H.; Tixier-Mita, A.

2017-05-01

In lab-on-a-chip (LoC) devices, microfluidic displacement of liquids is a key component. electrowetting on dielectric (EWOD) is a technique to move fluids, with the advantage of not requiring channels, pumps or valves. Fluids are discretized into droplets on microelectrodes and moved by applying an electric field via the electrodes to manipulate the contact angle. Micro-objects, such as biological cells, can be transported inside of these droplets. However, the design of conventional microelectrodes, made by standard micro-fabrication techniques, fixes the path of the droplets, and limits the reconfigurability of paths and thus limits the parallel processing of droplets. In that respect, thin film transistor (TFT) technology presents a great opportunity as it allows infinitely reconfigurable paths, with high parallelizability. We propose here to investigate the possibility of using TFT array devices for high throughput cell manipulation using EWOD. A COMSOL based 2D simulation coupled with a MATLAB algorithm was used to simulate the contact angle modulation, displacement and mixing of droplets. These simulations were confirmed by experimental results. The EWOD technique was applied to a droplet of culture medium containing HepG2 carcinoma cells and demonstrated no negative effects on the viability of the cells. This confirms the possibility of applying EWOD techniques to cellular applications, such as parallel cell analysis.

Microfluidics Transport and Path Control via Programmable Electrowetting on Dielectric

DOE Office of Scientific and Technical Information (OSTI.GOV)

Theodore W. Von Bitner, Ph.D.

2002-08-22

This research was conducted in collaboration with Professor Chang-Jin Kim of the University of California, Los Angeles. In phase I, the IOS-UCLA collaboration demonstrated the transport and manipulation of insulting liquid droplets using the principles of EWOD. A postage stamp sized array of electronically addressable Teflon pads, whose surface tension characteristics could be altered on command through computer algorithms, was developed and tested using deionized water as the liquid. Going beyond the tasks originally proposed for Phase I, droplet manipulation was achieved and droplet stability in the EWOD device was examined.

Effect of oil on an electrowetting lenticular lens and related optical characteristics.

PubMed

Shin, Dooseub; Kim, Junoh; Kim, Cheoljoong; Koo, Gyo Hyun; Sim, Jee Hoon; Lee, Junsik; Won, Yong Hyub

2017-03-01

While there are many ways to realize autostereoscopic 2D/3D switchable displays, the electrowetting lenticular lens is superior due to the high optical efficiency and short response time. In this paper, we propose a more stable electrowetting lenticular lens by controlling the quantity of oil. With a large amount of oil, the oil layer was broken and the lenticular lens was damaged at relatively low voltage. Therefore, controlling the amount of oil is crucial to obtain the required dioptric power with stability. We proposed a new structure to evenly adjust the volume of oil and the dioptric power was measured by varying the volume of oil. Furthermore, the optical characteristics were finally analyzed in the electrowetting lenticular lens array with a proper amount of oil.

Agile wide-angle beam steering with electrowetting microprisms

NASA Astrophysics Data System (ADS)

Smith, Neil R.; Abeysinghe, Don C.; Haus, Joseph W.; Heikenfeld, Jason

2006-07-01

A novel basis for beam steering with electrowetting microprisms (EMPs) is reported. EMPs utilize electrowetting modulation of liquid contact angle in order to mimic the refractive behavior for various classical prism geometries. Continuous beam steering through an angle of 14° (±7°) has been demonstrated with a liquid index of n=1.359. Experimental results are well-matched to theoretical behavior up to the point of electrowetting contact-angle saturation. Projections show that use of higher index liquids (n~1.6) will result in steering through ~30° (±15°). Fundamental factors defining achievable deflection range, and issues for Ladar use, are reviewed. This approach is capable of good switching speed (~ms), polarization independent operation, modulation of beam field-of-view (lensing), and high steering efficiency that is independent of deflection angle.

Focus-tunable liquid cylindrical lens based on electrowetting

NASA Astrophysics Data System (ADS)

Tan, Yanting; Peng, Runling

2017-10-01

The double-liquid focus-tunable lens based on electrowetting on dielectrics is attracting many researchers' attention because of compact volume, quick responding speed, low consumption etc. In this paper, a focus-tunable liquid cylindrical lens based on electrowetting is designed, the structure and operating principles of this lens are introduced. COMSOL Multiphysics is chamber, and the focal length is varied continuously. According to the materials used in our laboratory, the focal length is estimated, ranging between (-∞, -38.6mm)υ(61.4mm, +∞).

Electrowetting-based optics

NASA Astrophysics Data System (ADS)

Kuiper, S.; Hendriks, B. H. W.; Hayes, R. A.; Feenstra, B. J.; Baken, J. M. E.

2005-09-01

Electrowetting is electrostatic manipulation of liquids. It can be used to displace and deform volumes of polar liquids. A very promising application area is optics. The surface of a volume of liquid can be used as a tunable lens and displacement of the liquid can change the refraction, diffraction or transmission of light when passing through the liquid. In this paper we describe a selection of various tunable optical components that make use of electrowetting, ranging from refractive and diffractive lenses to diaphragms and displays.

Simulation of electrowetting lens and prism arrays for wavefront compensation.

PubMed

Gopinath, Juliet T; Bright, Victor M; Cogswell, Carol C; Niederriter, Robert D; Watson, Alexander; Zahreddine, Ramzi; Cormack, Robert H

2012-09-20

A novel application of electrowetting devices has been simulated: wavefront correction using an array of electrowetting lenses and prisms. Five waves of distortion can be corrected with Strehl ratios of 0.9 or higher, utilizing piston, tip-tilt, and curvature corrections from arrays of 19 elements and fill factors as low as 40%. Effective control of piston can be achieved by placing the liquid lens array at the focus of two microlens arrays. Seven waves of piston delay can be generated with variation in focal length between 1.5 and 500 mm.

Adaptive beam tracking and steering via electrowetting-controlled liquid prism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, JT; Chen, CL

2011-11-07

We report an electrowetting-controlled optofluidic system for adaptive beam tracking and agile steering. With two immiscible fluids in a transparent cell, we can actively control the contact angle along the fluid-fluid-solid tri-junction line and hence the orientation of the fluid-fluid interface via electrowetting. The naturally formed meniscus between the two liquids can function as an optical prism. We have fabricated a liquid prism module with an aperture size of 10 mm -10mm. With 1 wt.% KCl and 1 wt.% Sodium Dodecyl Sulfate added into deionized water, the orientation of the water-silicone oil interface has been modulated between -26 degrees andmore » 26 degrees that can deflect and steer beam within the incidence angle of 0 degrees-15 degrees. The wide-range beam tracking and steering enables the liquid prism work as an electrowetting solar cell. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3660578]« less

Adaptive beam tracking and steering via electrowetting-controlled liquid prism

NASA Astrophysics Data System (ADS)

Cheng, Jiangtao; Chen, Chung-Lung

2011-11-01

We report an electrowetting-controlled optofluidic system for adaptive beam tracking and agile steering. With two immiscible fluids in a transparent cell, we can actively control the contact angle along the fluid-fluid-solid tri-junction line and hence the orientation of the fluid-fluid interface via electrowetting. The naturally formed meniscus between the two liquids can function as an optical prism. We have fabricated a liquid prism module with an aperture size of 10 mm × 10mm. With 1 wt. % KCl and 1 wt. % Sodium Dodecyl Sulfate added into deionized water, the orientation of the water-silicone oil interface has been modulated between -26° and 26° that can deflect and steer beam within the incidence angle of 0°-15°. The wide-range beam tracking and steering enables the liquid prism work as an electrowetting solar cell.

Liquid micro-lens array activated by selective electrowetting on lithium niobate substrates.

PubMed

Grilli, S; Miccio, L; Vespini, V; Finizio, A; De Nicola, S; Ferraro, Pietro

2008-05-26

Lens effect was obtained in an open microfluidic system by using a thin layer of liquid on a polar electric crystal like LiNbO3. An array of liquid micro-lenses was generated by electrowetting effect in pyroelectric periodically poled crystals. Compared to conventional electrowetting devices, the pyroelectric effect allowed to have an electrode-less and circuit-less configuration. An interferometric technique was used to characterize the curvature of the micro-lenses and the corresponding results are presented and discussed. The preliminary results concerning the imaging capability of the micro-lens array are also reported.

Optofluidic solar concentrators using electrowetting tracking: Concept, design, and characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, JT; Park, S; Chen, CL

2013-03-01

We introduce a novel optofluidic solar concentration system based on electrowetting tracking. With two immiscible fluids in a transparent cell, we can actively control the orientation of fluid fluid interface via electrowetting. The naturally-formed meniscus between the two liquids can function as a dynamic optical prism for solar tracking and sunlight steering. An integrated optofluidic solar concentrator can be constructed from the liquid prism tracker in combination with a fixed and static optical condenser (Fresnel lens). Therefore, the liquid prisms can adaptively focus sunlight on a concentrating photovoltaic (CPV) cell sitting on the focus of the Fresnel lens as themore » sun moves. Because of the unique design, electrowetting tracking allows the concentrator to adaptively track both the daily and seasonal changes of the sun's orbit (dual-axis tracking) without bulky, expensive and inefficient mechanical moving parts. This approach can potentially reduce capital costs for CPV and increases operational efficiency by eliminating the power consumption of mechanical tracking. Importantly, the elimination of bulky tracking hardware and quiet operation will allow extensive residential deployment of concentrated solar power. In comparison with traditional silicon-based photovoltaic (PV) solar cells, the electrowetting-based self-tracking technology will generate,similar to 70% more green energy with a 50% cost reduction. (C) 2013 Elsevier Ltd. All rights reserved.« less

TOPICAL REVIEW: Electrowetting: from basics to applications

NASA Astrophysics Data System (ADS)

Mugele, Frieder; Baret, Jean-Christophe

2005-07-01

Electrowetting has become one of the most widely used tools for manipulating tiny amounts of liquids on surfaces. Applications range from 'lab-on-a-chip' devices to adjustable lenses and new kinds of electronic displays. In the present article, we review the recent progress in this rapidly growing field including both fundamental and applied aspects. We compare the various approaches used to derive the basic electrowetting equation, which has been shown to be very reliable as long as the applied voltage is not too high. We discuss in detail the origin of the electrostatic forces that induce both contact angle reduction and the motion of entire droplets. We examine the limitations of the electrowetting equation and present a variety of recent extensions to the theory that account for distortions of the liquid surface due to local electric fields, for the finite penetration depth of electric fields into the liquid, as well as for finite conductivity effects in the presence of AC voltage. The most prominent failure of the electrowetting equation, namely the saturation of the contact angle at high voltage, is discussed in a separate section. Recent work in this direction indicates that a variety of distinct physical effects—rather than a unique one—are responsible for the saturation phenomenon, depending on experimental details. In the presence of suitable electrode patterns or topographic structures on the substrate surface, variations of the contact angle can give rise not only to continuous changes of the droplet shape, but also to discontinuous morphological transitions between distinct liquid morphologies. The dynamics of electrowetting are discussed briefly. Finally, we give an overview of recent work aimed at commercial applications, in particular in the fields of adjustable lenses, display technology, fibre optics, and biotechnology-related microfluidic devices.

Zoom microscope objective using electrowetting lenses.

PubMed

Li, Lei; Wang, Di; Liu, Chao; Wang, Qiong-Hua

2016-02-08

We report a zoom microscope objective which can achieve continuous zoom change and correct the aberrations dynamically. The objective consists of three electrowetting liquid lenses and two glass lenses. The magnification is changed by applying voltages on the three electrowetting lenses. Besides, the three electrowetting liquid lenses can play a role to correct the aberrations. A digital microscope based on the proposed objective is demonstrated. We analyzed the properties of the proposed objective. In contrast to the conventional objectives, the proposed objective can be tuned from ~7.8 × to ~13.2 × continuously. For our objective, the working distance is fixed, which means no movement parts are needed to refocus or change its magnification. Moreover, the zoom objective can be dynamically optimized for a wide range of wavelength. Using such an objective, the fabrication tolerance of the optical system is larger than that of a conventional system, which can decrease the fabrication cost. The proposed zoom microscope objective cannot only take place of the conventional objective, but also has potential application in the 3D microscopy.

Low Voltage Electrowetting on Ferroelectric PVDF-HFP Insulator with Highly Tunable Contact Angle Range.

PubMed

Sawane, Yogesh B; Ogale, Satishchandra B; Banpurkar, Arun G

2016-09-14

We demonstrate a consistent electrowetting response on ferroelectric poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) insulator covered with a thin Teflon AF layer. This bilayer exhibits a factor of 3 enhancement in the contact angle modulation compared to that of conventional single-layered Teflon AF dielectric. On the basis of the proposed model the enhancement is attributed to the high value of effective dielectric constant (εeff ≈ 6) of the bilayer. Furthermore, the bilayer dielectric exhibits a hysteresis-free contact angle modulation over many AC voltage cycles. But the contact angle modulation for DC voltage shows a hysteresis because of the field-induced residual polarization in the ferroelectric layer. Finally, we show that a thin bilayer exhibits contact angle modulation of Δθ (U) ≈ 60° at merely 15 V amplitude of AC voltage indicating a potential dielectric for practical low voltage electrowetting applications. A proof of concept confirms electrowetting based rapid mixing of a fluorescent dye in aqueous glycerol solution for 15 V AC signal.

Suppressing the coffee stain effect: how to control colloidal self-assembly in evaporating drops using electrowetting

NASA Astrophysics Data System (ADS)

Eral, Burak; Mampallil Augustine, Dileep; Duits, Michel; Mugele, Frieder; Physics of Complex Fluids Group, University of Twente Team

2011-11-01

We study the influence of electrowetting on the evaporative self-assembly and formation of undesired solute residues, so-called coffee stains, during the evaporation of a drop containing non-volatile solvents. Electrowetting is found to suppress coffee stains of both colloidal particles of various sizes and DNA solutions at alternating (AC) frequencies ranging from a few Hertz to a few tens of kHz. Two main effects are shown to contribute to the suppression: (i) the time-dependent electrostatic force prevents pinning of the three phase contact line and (ii) internal flow fields generated by AC electrowetting counteract the evaporation driven flux and thereby prevent the accumulation of solutes along the contact line Please see the link below for a short presentation and movies: http://www.youtube.com/watch?v=xwipCVZnN4E We thank the Chemical Sciences division of the Netherlands Organization for Scientific Research (NWO-CW) for financial support (ECHO grant).

Jumping and trampolining of drops on hydrophobic surfaces, controlling energy transfer by timed electric actuation

NASA Astrophysics Data System (ADS)

Wang, Zhantao; Ende, Dirk Van Den; Pit, Arjen; Lagraauw, Rudy; Wijnperle, Daniel; Mugele, Frieder

2017-11-01

Electrowetting as a fast and efficient approach of manipulating droplet has found wide applications in microfluidics, and recently the potential of using electrowetting for 3-dimensional microfluidics was also demonstrated. Here the electrowetting-induced jumping of a single droplet on a superhydrophobic surface was studied in both air and ambient decane. The jumping height of the droplet was found to be not only voltage-dependent but also oscillating with the AC-pulse duration. We identify the electrowetting number as a crucial parameter in defining the resonant frequency of the droplet under actuation. Representing the drop by a simple oscillator, we establish a relation between the Eigen frequency of the drop and the optimum actuation time required for most efficient energy conversion. From a general perspective, our experiments illustrate a generic concept how timed actuation in combination with inertia can enhance the flexibility and efficiency of drop manipulation operations. Dutch Technology Foundation (STW) is acknowledged.

Ultra-low voltage electrowetting using graphite surfaces.

PubMed

Lomax, Deborah J; Kant, Pallav; Williams, Aled T; Patten, Hollie V; Zou, Yuqin; Juel, Anne; Dryfe, Robert A W

2016-10-26

The control of wetting behaviour underpins a variety of important applications from lubrication to microdroplet manipulation. Electrowetting is a powerful method to achieve external wetting control, by exploiting the potential-dependence of the liquid contact angle with respect to a solid substrate. Addition of a dielectric film to the surface of the substrate, which insulates the electrode from the liquid thereby suppressing electrolysis, has led to technological advances such as variable focal-length liquid lenses, electronic paper and the actuation of droplets in lab-on-a-chip devices. The presence of the dielectric, however, necessitates the use of large bias voltages (frequently in the 10-100 V range). Here we describe a simple, dielectric-free approach to electrowetting using the basal plane of graphite as the conducting substrate: unprecedented changes in contact angle for ultra-low voltages are seen below the electrolysis threshold (50° with 1 V for a droplet in air, and 100° with 1.5 V for a droplet immersed in hexadecane), which are shown to be reproducible, stable over 100 s of cycles and free of hysteresis. Our results dispel conventional wisdom that reversible, hysteresis-free electrowetting can only be achieved on solid substrates with the use of a dielectric. This work paves the way for the development of a new generation of efficient electrowetting devices using advanced materials such as graphene and monolayer MoS 2 .

Promotion of Water Channels for Enhanced Ion Transport in 14 nm Diameter Carbon Nanotubes.

PubMed

Sheng, Jiadong; Zhu, Qi; Zeng, Xian; Yang, Zhaohui; Zhang, Xiaohua

2017-03-29

Ion transport plays an important role in solar-to-electricity conversion, drug delivery, and a variety of biological processes. Carbon nanotube (CNT) is a promising material as an ion transporter in the applications of the mimicking of natural ion channels, desalination, and energy harvesting. Here, we demonstrate a unique, enhanced ion transport through a vertically aligned multiwall CNT membrane after the application of an electric potential across CNT membranes. Interestingly, electrowetting arising from the application of an electric potential is critical for the enhancement of overall ion transport rate through CNT membranes. The wettability of a liquid with high surface tension on the interior channel walls of CNTs increases during an electric potential treatment and promotes the formation of water channels in CNTs. The formation of water channels in CNTs induces an increase in overall ion diffusion through CNT membranes. This phenomenon is also related to a decrease in the charge transfer resistance of CNTs (R ct ) after an electric potential is applied. Correspondingly, the enhanced ion flow rate gives rise to an enhancement in the capacitive performance of CNT based membranes. Our observations might have profound impact on the development of CNT based energy storage devices as well as artificial ion channels.

Microscale Convective Heat Transfer for Thermal Management of Compact Systems

DTIC Science & Technology

2012-03-12

pages 641–645, 1997. [9] S.V. Garimella and C.B. Sobhan. Transport in microchannels -a critical review. Annual Review of Heat Transfer , 13, 2003. [10] A... heat transfer for thermal management of compact systems Sb. GRANT NUMBER F A9550-08-l-0057 Sc. PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) Sd...improve the performance of many components. The e ects of digitized heat transfer using electrowetting on a dielectric were investigated in this paper

Picoliter DNA Sequencing Chemistry on an Electrowetting-based Digital Microfluidic Platform

PubMed Central

Ferguson Welch, Erin R.; Lin, Yan-You; Madison, Andrew; Fair, R.B.

2011-01-01

The results of investigations into performing DNA sequencing chemistry on a picoliter-scale electrowetting digital microfluidic platform are reported. Pyrosequencing utilizes pyrophosphate produced during nucleotide base addition to initiate a process ending with detection through a chemiluminescence reaction using firefly luciferase. The intensity of light produced during the reaction can be quantified to determine the number of bases added to the DNA strand. The logic-based control and discrete fluid droplets of a digital microfluidic device lend themselves well to the pyrosequencing process. Bead-bound DNA is magnetically held in a single location, and wash or reagent droplets added or split from it to circumvent product dilution. Here we discuss the dispensing, control, and magnetic manipulation of the paramagnetic beads used to hold target DNA. We also demonstrate and characterize the picoliter-scale reaction of luciferase with adenosine triphosphate to represent the detection steps of pyrosequencing and all necessary alterations for working on this scale. PMID:21298802

Optical switch based on electrowetting liquid lens

NASA Astrophysics Data System (ADS)

Li, Lei; Liu, Chao; Peng, Hua-Rong; Wang, Qiong-Hua

2012-05-01

In this paper, we propose an optical switch based on an electrowetting liquid lens. The device consists of an electrowetting liquid lens and a non-transparent cap with a pin hole. When the lens is actuated to be positive, the incident light can be converged on the pin hole and pass through the hole with less attenuation. When the lens is deformed to be negative, the incident light is diverged and most of light is blocked by the cap. Our results show that the system can provide high contrast ratio (˜800:1) and reasonable response time (˜88 ms). The proposed optical switch has potential application in light shutters, variable optical attenuators, and adaptive irises.

A Liquid Optical Phase Shifter with an Embedded Electrowetting Actuator

PubMed Central

Ashtiani, Alireza Ousati; Jiang, Hongrui

2017-01-01

We demonstrate an electrowetting-based liquid optical phase shifter. The phase shifter consists of two immiscible liquid layers with different refractive indices. Sandwiched between the two liquids is a rigid membrane that moves freely along the optical axis and supported by a compliant surround. When applied with a pressure, the thicknesses of both liquid layers change, which induces a difference in optical path, resulting in a phase shift. A miniaturized electrowetting-based actuator is used to produce hydraulic pressure. A multi-layered SU8 bonded structure was fabricated. A phase shift of 171° was observed when the device was incorporated in a Mach-Zehnder interferometer and driven with 100 V. PMID:29038640

Optical application of electrowetting

NASA Astrophysics Data System (ADS)

He, Mei; Peng, Runling; Chen, Jiabi

2017-02-01

Since electrowetting has been proposed, researchers began to apply eletrowetting into different fields, such as lab-on-chip systems, display technologies, printings and optics etc. This paper mainly introduced structure, theory and application of optical devices based on electrowetting. The optical devices include liquid optical prism, liquid optical lens and display. The paper introduced their principle, specific application and many advantages in optical applications. When they are applied to optical system, production and experiment, they can reduce mechanical moving parts, simplify the structure, operate easily, decrease manufacturing cost and energy consumption, improve working efficiency, and so on. We learn and research them in detail that will contribute to research and develop optical eletrowetting in the future.

Microelectrofluidic lens for variable curvature

NASA Astrophysics Data System (ADS)

Chang, Jong-hyeon; Lee, Eunsung; Jung, Kyu-Dong; Lee, Seungwan; Choi, Minseog; Kim, Woonbae

2012-10-01

This paper presents a tunable liquid lens based on microelectrofluidic technology which integrates electrowetting and microfluidics. In the novel microelectrofluidic lens (MEFL), electrowetting in the hydrophobic surface channel induces the Laplace pressure difference between two fluidic interfaces on the lens aperture and the surface channel. Then, the pressure difference makes the lens curvature tunable. The previous electrowetting lens in which the contact angle changes at the side wall has a certain limitation of the curvature variation because of the contact angle saturation. Although the contact angle saturation also appears in the surface channel of the MEFL, the low surface channel increases the Laplace pressure and it makes the MEFL to have full variation of the optical power possible. The magnitude of the applied voltage determines the lens curvature in the analog mode MEFL as well as the electrowetting lens. Digital operation is also possible when the control electrodes of the MEFL are patterned to have an array. It is expected that the proposed MEFL is able to be widely used because of its full variation of the optical power without the use of oil and digital operation with fast response.

A planar lens based on the electrowetting of two immiscible liquids

NASA Astrophysics Data System (ADS)

Liu, Chao-Xuan; Park, Jihwan; Choi, Jin-Woo

2008-03-01

This paper reports the development and characterization of a planar liquid lens based on electrowetting. The working concept of electrowetting two immiscible liquids is demonstrated with measurement and characterization of contact angles with regard to externally applied electric voltages. Consequently, a planar liquid lens is designed and implemented based on this competitive electrowetting. A droplet of silicone oil confined in an aqueous solution (1% KCl) works as a liquid lens. Electrowetting then controls the shape of the confined silicone oil and the focal length of the liquid lens varies depending upon an applied dc voltage. A unique feature of this lens design is the double-ring planar electrodes beneath the hydrophobic substrate. While an outer ring electrode provides an initial boundary for the silicone oil droplet, an inner ring works as the actuation electrode for the lens. Further, the planar electrodes, instead of vertical or out-of-plane wall electrodes, facilitate the integration of liquid lenses into microfluidic systems. With the voltage applied in the range of 50-250 V, the confined silicone oil droplet changed its shape and the optical magnification of a 3 mm-diameter liquid lens was clearly demonstrated. Moreover, focal lengths of liquid lenses with diameters of 2 mm, 3 mm and 4 mm were characterized, respectively. The obtained results suggest that a larger lens diameter yields a longer focal length and a wider range of focal length change in response to voltage. The demonstrated liquid lens has a simple structure and is easy to fabricate.

Electrowetting-driven spreading and jumping of drops in oil

NASA Astrophysics Data System (ADS)

Hong, Jiwoo; Lee, Sang Joon

2013-11-01

Electrowetting-based practical applications include digital microfluidics, liquid lenses, and reflective displays. Most of them are performed in water/oil system, because oil medium reduces the contact-angle hysteresis and prevents drop evaporation. In this study, the effects of drop volume, oil viscosity, and applied voltage on the dynamic behaviors of spreading drops, such as transition of spreading pattern and response time, are investigated. Interestingly, jumping phenomena of drops are observed in oil when the applied voltage is turned off after reaching the electrowetted equilibrium radius of drops. A numerical model to predict the transient behavior of jumping drops is formulated based on the phase-field method. The numerical results for the transient deformation of jumping drops show quantitative agreement with the experimental results.

Liquid lens based on electrowetting: actual developments on larger aperture and multiple electrodes design for image stabilization or beam steering

NASA Astrophysics Data System (ADS)

Berge, Bruno; Broutin, Jérôme; Gaton, Hilario; Malet, Géraldine; Simon, Eric; Thieblemont, Florent

2013-03-01

This paper presents experimental results on several liquid lenses based on Electrowetting which are commercially available. It will be shown that larger aperture lenses are basically of the same optical quality than smaller lenses, sometimes reaching the diffraction limit, then opening new kind of applications areas for variable lenses in laser science. Regarding response time, actual performances of liquids lenses based on Electrowetting are presented and compared to a model simulating the internal fluid reorganization, seen as the main source of delay between electrical actuation and optical evolution of the lens. This simplified analytical model is supporting experimental results in various situations (focus and tilt variations), in static and dynamic regimes.

Capillary wave propagation during the delamination of graphene by the precursor films in electro-elasto-capillarity

PubMed Central

Zhu, Xueyan; Yuan, Quanzi; Zhao, Ya-Pu

2012-01-01

Molecular dynamics simulations were carried out to explore the capillary wave propagation induced by the competition between one upper precursor film (PF) on the graphene and one lower PF on the substrate in electro-elasto-capillarity (EEC). During the wave propagation, the graphene was gradually delaminated from the substrate by the lower PF. The physics of the capillary wave was explored by the molecular kinetic theory. Besides, the dispersion relation of the wave was obtained theoretically. The theory showed that the wave was controlled by the driving work difference of the two PFs. Simulating the EEC process under different electric field intensities (E), the wave velocity was found insensitive to E. We hope this research could expand our knowledge on the wetting, electrowetting and EEC. As a potential application, the electrowetting of the PF between the graphene and the substrate is a promising candidate for delaminating graphene from substrate. PMID:23226593

Electrowetting in a water droplet with a movable floating substrate

NASA Astrophysics Data System (ADS)

Shahzad, Amir; Masud, A. R.; Song, Jang-Kun

2016-05-01

Electrowetting (EW) enables facile manipulation of a liquid droplet on a hydrophobic surface. In this study, manipulation of an electrolyte droplet having a small floating object on it was investigated on a solid hydrophobic substrate under the EW process. Herein, the floating object exhibited a vertical motion under an applied electric field owing to the spreading and contraction of the droplet on its connecting substrates. The field-induced height variation of the floating object was significantly influenced by the thicknesses of the dielectric and hydrophobic materials. A small mass was also placed on the top floating object and its effect on the spreading of the droplet was observed. In this system, the height of the top floating object is precisely controllable under the application of an electric voltage. The proposed system is expected to be highly useful in the design of nano- and micro-oscillatory systems for microengineering.

Electrowetting in a water droplet with a movable floating substrate.

PubMed

Shahzad, Amir; Masud, A R; Song, Jang-Kun

2016-05-01

Electrowetting (EW) enables facile manipulation of a liquid droplet on a hydrophobic surface. In this study, manipulation of an electrolyte droplet having a small floating object on it was investigated on a solid hydrophobic substrate under the EW process. Herein, the floating object exhibited a vertical motion under an applied electric field owing to the spreading and contraction of the droplet on its connecting substrates. The field-induced height variation of the floating object was significantly influenced by the thicknesses of the dielectric and hydrophobic materials. A small mass was also placed on the top floating object and its effect on the spreading of the droplet was observed. In this system, the height of the top floating object is precisely controllable under the application of an electric voltage. The proposed system is expected to be highly useful in the design of nano- and micro-oscillatory systems for microengineering.

Mixed Cassie-Baxter wetting states on a porous material stabilized by electrowetting

NASA Astrophysics Data System (ADS)

Lambert, Jérôme; Gauchet, Lucien; Crassous, Jérôme

2017-07-01

Electrowetting is used to force imbibition in model porous plates. These porous plates are sintered disordered bronze bead packings that are homogeneously coated with a constant-thickness layer of parylene. Cycles of increasing and decreasing voltage trigger the imbibition of a ionized water sessile drop by changing its contact angle with the porous material from non-wetting to wetting shapes. During a cycle, a drop experiences partial imbibition and a strong hysteresis of its contact angle with the porous plate. Since the imbibition process quickly stabilizes, we adopt an equilibrium description of the wetting properties of the drop on the porous plate. Our model, based on the Cassie-Baxter approach, shows that three different wetting states are experienced by the drop, one of which being made possible only by the modification of the contact angle inside the pores. Our model describes the experimental results very well.

'No power' (green) electrowetting display

NASA Astrophysics Data System (ADS)

Jentsch, Michael; Rawert, Juergen; Jerosch, Dieter; Blankenbach, Karlheinz

2011-05-01

Electrowetting displays were first reported in 1981, several approaches were examined. However, ADT's "Droplet- Driven-Displays" technology is the only bistable one which makes them very attractive for energy-saving systems. That means that the power supply can completely shut off after changing the content and it will keep its information for years. More features that make the ADT approach very unique are paper like white appearance (even in the powerless OFFstate) and the capability for backlighting (most of the other e-paper technologies like electrophoretics can not be backlighted). Further achievements are a white state reflectance of about 70% resulting in sunlight readability and a pixel size in the range from 0.3mm to 10mm. Summarizing, ADT's electrowetting technology is highly suitable for lowest power (means eco-friendly or "green") displays.

A highly efficient bead extraction technique with low bead number for digital microfluidic immunoassay

PubMed Central

Tsai, Po-Yen; Lee, I-Chin; Hsu, Hsin-Yun; Huang, Hong-Yuan; Fan, Shih-Kang; Liu, Cheng-Hsien

2016-01-01

Here, we describe a technique to manipulate a low number of beads to achieve high washing efficiency with zero bead loss in the washing process of a digital microfluidic (DMF) immunoassay. Previously, two magnetic bead extraction methods were reported in the DMF platform: (1) single-side electrowetting method and (2) double-side electrowetting method. The first approach could provide high washing efficiency, but it required a large number of beads. The second approach could reduce the required number of beads, but it was inefficient where multiple washes were required. More importantly, bead loss during the washing process was unavoidable in both methods. Here, an improved double-side electrowetting method is proposed for bead extraction by utilizing a series of unequal electrodes. It is shown that, with proper electrode size ratio, only one wash step is required to achieve 98% washing rate without any bead loss at bead number less than 100 in a droplet. It allows using only about 25 magnetic beads in DMF immunoassay to increase the number of captured analytes on each bead effectively. In our human soluble tumor necrosis factor receptor I (sTNF-RI) model immunoassay, the experimental results show that, comparing to our previous results without using the proposed bead extraction technique, the immunoassay with low bead number significantly enhances the fluorescence signal to provide a better limit of detection (3.14 pg/ml) with smaller reagent volumes (200 nl) and shorter analysis time (<1 h). This improved bead extraction technique not only can be used in the DMF immunoassay but also has great potential to be used in any other bead-based DMF systems for different applications. PMID:26858807

Efficient Solar Concentrators: Affordable Energy from Water and Sunlight

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2010-01-01

Broad Funding Opportunity Announcement Project: Teledyne is developing a liquid prism panel that tracks the position of the sun to help efficiently concentrate its light onto a solar cell to produce power. Typically, solar tracking devices have bulky and expensive mechanical moving parts that require a lot of power and are often unreliable. Teledyne’s liquid prism panel has no bulky and heavy supporting parts—instead it relies on electrowetting. Electrowetting is a process where an electric field is applied to the liquid to control the angle at which it meets the sunlight above and to control the angle of the sunlightmore » to the focusing lensthe more direct the angle to the focusing lens, the more efficiently the light can be concentrated to solar panels and converted into electricity. This allows the prism to be tuned like a radio to track the sun across the sky and steer sunlight into the solar cell without any moving mechanical parts. This process uses very little power and requires no expensive supporting hardware or moving parts, enabling efficient and quiet rooftop operation for integration into buildings.« less

Research on surface free energy of electrowetting liquid zoom lens

NASA Astrophysics Data System (ADS)

Zhao, Cunhua; Lu, Gaoqi; Wei, Daling; Hong, Xinhua; Cui, Dongqing; Gao, Changliu

2011-08-01

Zoom imaging systems have the tendencies of miniaturization or complication so the traditional glass / plastic lenses can't meet the needs. Therefore, a new method, liquid lens is put forward which realizes zoom by changing the shape of liquid surface. liquid zoom lenses have many merits such as smaller volume, lighter weight, controlled zoom, faster response, higher transmission, lower energy consumption and so on. Liquid zoom lenses have wide applications in mobile phones, digital cameras and other small imaging system. The electrowetting phenomenon was reviewed firstly and then the influence of the exerted voltage to the contact angle was analysed in electrowetting effect. At last, the surface free energy of cone-type double liquid zoom lens was researched via the energy minimization principle. The research of surface free energy offers important theoretic dependence for designing liquid zoom lens.

Enhanced Response Time of Electrowetting Lenses with Shaped Input Voltage Functions.

PubMed

Supekar, Omkar D; Zohrabi, Mo; Gopinath, Juliet T; Bright, Victor M

2017-05-16

Adaptive optical lenses based on the electrowetting principle are being rapidly implemented in many applications, such as microscopy, remote sensing, displays, and optical communication. To characterize the response of these electrowetting lenses, the dependence upon direct current (DC) driving voltage functions was investigated in a low-viscosity liquid system. Cylindrical lenses with inner diameters of 2.45 and 3.95 mm were used to characterize the dynamic behavior of the liquids under DC voltage electrowetting actuation. With the increase of the rise time of the input exponential driving voltage, the originally underdamped system response can be damped, enabling a smooth response from the lens. We experimentally determined the optimal rise times for the fastest response from the lenses. We have also performed numerical simulations of the lens actuation with input exponential driving voltage to understand the variation in the dynamics of the liquid-liquid interface with various input rise times. We further enhanced the response time of the devices by shaping the input voltage function with multiple exponential rise times. For the 3.95 mm inner diameter lens, we achieved a response time improvement of 29% when compared to the fastest response obtained using single-exponential driving voltage. The technique shows great promise for applications that require fast response times.

Performance and Reliability of Electrowetting-on-Dielectric (EWOD) Systems Based on Tantalum Oxide.

PubMed

Mibus, Marcel; Zangari, Giovanni

2017-12-06

The electrowetting-on-dielectric behavior of Cytop/Tantalum oxide (TaOx) bilayers is studied by measuring their response vs applied voltage and under prolonged periodic cycling, below and above the threshold voltage V T corresponding to the breakdown field for the oxide. TaOx exhibits symmetric solid state I-V characteristics, with electronic conduction dominated by Schottky, Poole-Frenkel emission; conduction is attributed to oxygen vacancies (6 × 10 16 cm -3 ), resulting in large currents at low bias. Electrolyte/Metal Oxide/Metal I-V characteristics show oxide degradation at (<5 V) cathodic bias; anodic bias in contrast results in stable characteristics until reaching the anodization voltage, where the oxide thickens, leading eventually to breakdown and oxygen production at the electrode. Electrowetting angle vs applied voltage undergoes three different stages: a parabolic variation of contact angle (CA) with applied voltage, CA saturation, and rebound of the CA to higher values due to degradation of the polymer layer. The contact angle remained stable for several hundred cycles if the applied voltage was less than V T ; degradation in contrast is fast when the voltage is above V T . Degradation of the electrowetting response with time is linked to charge accumulation in the polymer, which inhibits the rebound of the CA when voltage is being applied.

Focus-tunable low-power electrowetting lenses with thin parylene films.

PubMed

Watson, Alexander M; Dease, Kevin; Terrab, Soraya; Roath, Christopher; Gopinath, Juliet T; Bright, Victor M

2015-07-10

Electrowetting lenses with record low power consumption (microwatts) have been demonstrated using high-quality parylene AF-4 dielectric layers and large dodecyl sulfate ions. Water and propylene glycol are interchanged as the polar liquid to enable diverging and converging lens operation achievable with the application of 15 V. The optical quality of the lenses is comparable to conventional microlenses and the tuning exhibits very little (<0.5°) contact angle hysteresis.

Electrowetting-based liquid lenses for endoscopy

NASA Astrophysics Data System (ADS)

Kuiper, S.

2011-03-01

In endoscopy there is a need for cameras with adjustable focus. In flexible and capsule endoscopes conventional focus systems are not suitable, because of restrictions in diameter and lens displacement range. In this paper it is shown that electrowetting-based variable-focus liquid lenses can provide a solution. A theoretical comparison is made between displacing and deforming lenses, and a demonstrator was built to prove the optical feasibility of focusing with liquid lenses in endoscopes.

Electrowetting on liquid-infused film (EWOLF): Complete reversibility and controlled droplet oscillation suppression for fast optical imaging

NASA Astrophysics Data System (ADS)

Hao, Chonglei; Liu, Yahua; Chen, Xuemei; He, Yuncheng; Li, Qiusheng; Li, K. Y.; Wang, Zuankai

2014-10-01

Electrowetting on dielectric (EWOD) has emerged as a powerful tool to electrically manipulate tiny individual droplets in a controlled manner. Despite tremendous progress over the past two decades, current EWOD operating in ambient conditions has limited functionalities posing challenges for its applications, including electronic display, energy generation, and microfluidic systems. Here, we demonstrate a new paradigm of electrowetting on liquid-infused film (EWOLF) that allows for complete reversibility and tunable transient response simultaneously. We determine that these functionalities in EWOLF are attributed to its novel configuration, which allows for the formation of viscous liquid-liquid interfaces as well as additional wetting ridges, thereby suppressing the contact line pinning and severe droplet oscillation encountered in the conventional EWOD. Finally, by harnessing these functionalities demonstrated in EWOLF, we also explore its application as liquid lens for fast optical focusing.

Electrowetting on liquid-infused film (EWOLF): Complete reversibility and controlled droplet oscillation suppression for fast optical imaging

PubMed Central

Hao, Chonglei; Liu, Yahua; Chen, Xuemei; He, Yuncheng; Li, Qiusheng; Li, K. Y.; Wang, Zuankai

2014-01-01

Electrowetting on dielectric (EWOD) has emerged as a powerful tool to electrically manipulate tiny individual droplets in a controlled manner. Despite tremendous progress over the past two decades, current EWOD operating in ambient conditions has limited functionalities posing challenges for its applications, including electronic display, energy generation, and microfluidic systems. Here, we demonstrate a new paradigm of electrowetting on liquid-infused film (EWOLF) that allows for complete reversibility and tunable transient response simultaneously. We determine that these functionalities in EWOLF are attributed to its novel configuration, which allows for the formation of viscous liquid-liquid interfaces as well as additional wetting ridges, thereby suppressing the contact line pinning and severe droplet oscillation encountered in the conventional EWOD. Finally, by harnessing these functionalities demonstrated in EWOLF, we also explore its application as liquid lens for fast optical focusing. PMID:25355005

Insulating Material Requirements for Low-Power-Consumption Electrowetting-Based Liquid Lenses.

PubMed

Chevalliot, Stéphanie; Malet, Géraldine; Keppner, Herbert; Berge, Bruno

2016-12-27

Insulating materials from the parylene family were investigated for use in low-power-consumption electrowetting-based liquid lenses. It was shown that for DC-driven operations, parylene C leads to hysteresis, regardless of the presence of a hydrophobic top coat. This hysteresis was attributed to the non-negligible time needed to reach a stable contact angle, due to charge injection and finite conductivity of the material. It was further demonstrated that by using materials with better insulating properties, such as parylene HT and VT4, satisfactory results can be obtained under DC voltages, reaching a low contact angle hysteresis of below 0.2°. We propose a simplified model that takes into account the injection of charges from both sides of the insulating material (the liquid side and the electrode side), showing that electrowetting response can be both increased and decreased.

Electrowetting on liquid-infused film (EWOLF): complete reversibility and controlled droplet oscillation suppression for fast optical imaging.

PubMed

Hao, Chonglei; Liu, Yahua; Chen, Xuemei; He, Yuncheng; Li, Qiusheng; Li, K Y; Wang, Zuankai

2014-10-30

Electrowetting on dielectric (EWOD) has emerged as a powerful tool to electrically manipulate tiny individual droplets in a controlled manner. Despite tremendous progress over the past two decades, current EWOD operating in ambient conditions has limited functionalities posing challenges for its applications, including electronic display, energy generation, and microfluidic systems. Here, we demonstrate a new paradigm of electrowetting on liquid-infused film (EWOLF) that allows for complete reversibility and tunable transient response simultaneously. We determine that these functionalities in EWOLF are attributed to its novel configuration, which allows for the formation of viscous liquid-liquid interfaces as well as additional wetting ridges, thereby suppressing the contact line pinning and severe droplet oscillation encountered in the conventional EWOD. Finally, by harnessing these functionalities demonstrated in EWOLF, we also explore its application as liquid lens for fast optical focusing.

Heterogeneous immunoassays using magnetic beads on a digital microfluidic platform.

PubMed

Sista, Ramakrishna S; Eckhardt, Allen E; Srinivasan, Vijay; Pollack, Michael G; Palanki, Srinivas; Pamula, Vamsee K

2008-12-01

A digital microfluidic platform for performing heterogeneous sandwich immunoassays based on efficient handling of magnetic beads is presented in this paper. This approach is based on manipulation of discrete droplets of samples and reagents using electrowetting without the need for channels where the droplets are free to move laterally. Droplet-based manipulation of magnetic beads therefore does not suffer from clogging of channels. Immunoassays on a digital microfluidic platform require the following basic operations: bead attraction, bead washing, bead retention, and bead resuspension. Several parameters such as magnetic field strength, pull force, position, and buffer composition were studied for effective bead operations. Dilution-based washing of magnetic beads was demonstrated by immobilizing the magnetic beads using a permanent magnet and splitting the excess supernatant using electrowetting. Almost 100% bead retention was achieved after 7776-fold dilution-based washing of the supernatant. Efficient resuspension of magnetic beads was achieved by transporting a droplet with magnetic beads across five electrodes on the platform and exploiting the flow patterns within the droplet to resuspend the beads. All the magnetic-bead droplet operations were integrated together to generate standard curves for sandwich heterogeneous immunoassays on human insulin and interleukin-6 (IL-6) with a total time to result of 7 min for each assay.

Wirelessly powered electrowetting-on-dielectric (EWOD) by planar receiver coils

NASA Astrophysics Data System (ADS)

Byun, Sang Hyun; Yuan, Junqi; Yoon, Myung Gon; Cho, Sung Kwon

2015-03-01

Electrowetting-on-dielectric (EWOD) is one of the most versatile methods used to control the wettability of liquids using electrical input. In most applications, EWOD is applied using physical wiring, which may restrict its application to implantable EWOD devices. In order to resolve this issue, we have studied and developed a wirelessly powered EWOD by using planar coils at the receiver that are fabricated out of a printed circuit board (PCB) by means of standard micro photolithography. Unlike conventional, bulky, spool coil type, the planar coil type lends itself to compact design and easy integration with EWOD chips. The present wireless powering principle is based on magnetic induction, which is very efficient when the transmitter and receiver coils are close to each other. The voltage obtained at the receiver is much higher than typically required EWOD voltages (>50 V) using a high transmission frequency (~MHz). The span of the EWOD contact angle is over 40°. In addition, amplitude modulation (AM) is implemented in the present wireless powering setup, followed by demodulation, in order to oscillate droplets at low frequency. This technique ensures smooth and reliable droplet movements. The wirelessly powered EWOD is used to transport a droplet and is mounted in a mini-boat which it powers and propels.

Heterogeneous Immunoassays Using Magnetic beads On a Digital Microfluidic Platform

PubMed Central

Sista, Ramakrishna S.; Eckhardt, Allen E.; Srinivasan, Vijay; Pollack, Michael G.; Palanki, Srinivas; Pamula, Vamsee K.

2009-01-01

A digital microfluidic platform for performing heterogeneous sandwich immunoassays based on efficient handling of magnetic beads is presented in this paper. This approach is based on manipulation of discrete droplets of samples and reagents using electrowetting without the need for channels where the droplets are free to move laterally. Droplet-based manipulation of magnetic beads therefore does not suffer from clogging of channels. Immunoassays on a digital microfluidic platform require the following basic operations: bead attraction, bead washing, bead retention, and bead resuspension. Several parameters such as magnetic field strength, pull force, position, and buffer composition were studied for effective bead operations. Dilution-based washing of magnetic beads was demonstrated by immobilizing the magnetic beads using a permanent magnet and splitting the excess supernatant using electrowetting. Almost 100% bead retention was achieved after 7776 fold dilution-based washing of the supernatant. Efficient resuspension of magnetic beads was achieved by transporting a droplet with magnetic beads across five electrodes on the platform and exploiting the flow patterns within the droplet to resuspend the beads. All the magnetic-bead droplet operations were integrated together to generate standard curves for sandwich heterogeneous immunoassays on Human Insulin and Interleukin-6 (IL-6) with a total time to result of seven minutes for each assay. PMID:19023486

An electrohydrodynamic flow in ac electrowetting.

PubMed

Lee, Horim; Yun, Sungchan; Ko, Sung Hee; Kang, Kwan Hyoung

2009-12-17

In ac electrowetting, hydrodynamic flows occur within a droplet. Two distinct flow patterns were observed, depending on the frequency of the applied electrical signal. The flow at low-frequency range was explained in terms of shape oscillation and a steady streaming process in conjunction with contact line oscillation. The origin of the flow at high-frequency range has not yet been explained. We suggest that the high-frequency flow originated mainly from the electrothermal effect, in which electrical charge is generated due to the gradient of electrical conductivity and permittivity, which is induced by the Joule heating of fluid medium. To support our argument, we analyzed the flow field numerically while considering the electrical body force generated by the electrothermal effect. We visualized the flow pattern and measured the flow velocity inside the droplet. The numerical results show qualitative agreement with experimental results with respect to electric field and frequency dependence of flow velocity. The effects of induced-charge electro-osmosis, natural convection, and the Marangoni flow are discussed.

Reverse electrowetting as a new approach to high-power energy harvesting

PubMed Central

Krupenkin, Tom; Taylor, J. Ashley

2011-01-01

Over the last decade electrical batteries have emerged as a critical bottleneck for portable electronics development. High-power mechanical energy harvesting can potentially provide a valuable alternative to the use of batteries, but, until now, a suitable mechanical-to-electrical energy conversion technology did not exist. Here we describe a novel mechanical-to-electrical energy conversion method based on the reverse electrowetting phenomenon. Electrical energy generation is achieved through the interaction of arrays of moving microscopic liquid droplets with novel nanometer-thick multilayer dielectric films. Advantages of this process include the production of high power densities, up to 103 W m−2; the ability to directly utilize a very broad range of mechanical forces and displacements; and the ability to directly output a broad range of currents and voltages, from several volts to tens of volts. These advantages make this method uniquely suited for high-power energy harvesting from a wide variety of environmental mechanical energy sources. PMID:21863015

Bubbler: A Novel Ultra-High Power Density Energy Harvesting Method Based on Reverse Electrowetting

PubMed Central

Hsu, Tsung-Hsing; Manakasettharn, Supone; Taylor, J. Ashley; Krupenkin, Tom

2015-01-01

We have proposed and successfully demonstrated a novel approach to direct conversion of mechanical energy into electrical energy using microfluidics. The method combines previously demonstrated reverse electrowetting on dielectric (REWOD) phenomenon with the fast self-oscillating process of bubble growth and collapse. Fast bubble dynamics, used in conjunction with REWOD, provides a possibility to increase the generated power density by over an order of magnitude, as compared to the REWOD alone. This energy conversion approach is particularly well suited for energy harvesting applications and can enable effective coupling to a broad array of mechanical systems including such ubiquitous but difficult to utilize low-frequency energy sources as human and machine motion. The method can be scaled from a single micro cell with 10−6 W output to power cell arrays with a total power output in excess of 10 W. This makes the fabrication of small light-weight energy harvesting devices capable of producing a wide range of power outputs feasible. PMID:26567850

Bubbler: A Novel Ultra-High Power Density Energy Harvesting Method Based on Reverse Electrowetting.

PubMed

Hsu, Tsung-Hsing; Manakasettharn, Supone; Taylor, J Ashley; Krupenkin, Tom

2015-11-16

We have proposed and successfully demonstrated a novel approach to direct conversion of mechanical energy into electrical energy using microfluidics. The method combines previously demonstrated reverse electrowetting on dielectric (REWOD) phenomenon with the fast self-oscillating process of bubble growth and collapse. Fast bubble dynamics, used in conjunction with REWOD, provides a possibility to increase the generated power density by over an order of magnitude, as compared to the REWOD alone. This energy conversion approach is particularly well suited for energy harvesting applications and can enable effective coupling to a broad array of mechanical systems including such ubiquitous but difficult to utilize low-frequency energy sources as human and machine motion. The method can be scaled from a single micro cell with 10(-6) W output to power cell arrays with a total power output in excess of 10 W. This makes the fabrication of small light-weight energy harvesting devices capable of producing a wide range of power outputs feasible.

Low-Voltage Electrowetting on a Lipid Bilayer Formed on Hafnium Oxide

DTIC Science & Technology

2011-06-01

currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 2. REPORT TYPE 3. DATES...exceeding 10 V [9-10]. Here we report the development of electrowetting systems that do not contain solid organic dielectrics such as fluoropolymers, but...and the effective thickness ( T 𔃺 : :) of the bilayer in response to applied voltage are plotted in Fig. 3(b). The capacitance per area increased with

Electrowetting lenses for compensating phase and curvature distortion in arrayed laser systems.

PubMed

Niederriter, Robert D; Watson, Alexander M; Zahreddine, Ramzi N; Cogswell, Carol J; Cormack, Robert H; Bright, Victor M; Gopinath, Juliet T

2013-05-10

We have demonstrated a one-dimensional array of individually addressable electrowetting tunable liquid lenses that compensate for more than one wave of phase distortion across a wavefront. We report a scheme for piston control using tunable liquid lens arrays in volume-bound cavities that alter the optical path length without affecting the wavefront curvature. Liquid lens arrays with separately tunable focus or phase control hold promise for laser communication systems and adaptive optics.

Realization of integral 3-dimensional image using fabricated tunable liquid lens array

NASA Astrophysics Data System (ADS)

Lee, Muyoung; Kim, Junoh; Kim, Cheol Joong; Lee, Jin Su; Won, Yong Hyub

2015-03-01

Electrowetting has been widely studied for various optical applications such as optical switch, sensor, prism, and display. In this study, vari-focal liquid lens array is developed using electrowetting principle to construct integral 3-dimensional imaging. The electrowetting principle that changes the surface tension by applying voltage has several advantages to realize active optical device such as fast response time, low electrical consumption, and no mechanical moving parts. Two immiscible liquids that are water and oil are used for forming lens. By applying a voltage to the water, the focal length of the lens could be tuned as changing contact angle of water. The fabricated electrowetting vari-focal liquid lens array has 1mm diameter spherical lens shape that has 1.6mm distance between each lens. The number of lenses on the panel is 23x23 and the focal length of the lens array is simultaneously tuned from -125 to 110 diopters depending on the applied voltage. The fabricated lens array is implemented to integral 3-dimensional imaging. A 3D object is reconstructed by fabricated liquid lens array with 23x23 elemental images that are generated by 3D max tools. When liquid lens array is tuned as convex state. From vari-focal liquid lens array implemented integral imaging system, we expect that depth enhanced integral imaging can be realized in the near future.

Quantitative Phase Microscopy for Accurate Characterization of Microlens Arrays

NASA Astrophysics Data System (ADS)

Grilli, Simonetta; Miccio, Lisa; Merola, Francesco; Finizio, Andrea; Paturzo, Melania; Coppola, Sara; Vespini, Veronica; Ferraro, Pietro

Microlens arrays are of fundamental importance in a wide variety of applications in optics and photonics. This chapter deals with an accurate digital holography-based characterization of both liquid and polymeric microlenses fabricated by an innovative pyro-electrowetting process. The actuation of liquid and polymeric films is obtained through the use of pyroelectric charges generated into polar dielectric lithium niobate crystals.

A low cost adaptive silicone membrane lens

NASA Astrophysics Data System (ADS)

Schneider, F.; Müller, C.; Wallrabe, U.

2008-04-01

This article introduces adaptive liquid lenses with thick silicone membranes of 5 mm diameter. These membranes are produced by means of casting in a batch process. The lenses feature an integrated piezo-bending actuator, which is also embedded in silicone. The lenses presented comprise areas of application which are not covered by the electrowetting lenses (diameter <3 mm) already established on the market.

Low voltage electrowetting lenticular lens by using multilayer dielectric structure

NASA Astrophysics Data System (ADS)

Lee, Junsik; Kim, Junoh; Kim, Cheoljoong; Shin, Dooseub; Koo, Gyohyun; Sim, Jee Hoon; Won, Yong Hyub

2017-02-01

Lenticular type multi-view display is one of the most popular ways for implementing three dimensional display. This method has a simple structure and exhibits a high luminance. However, fabricating the lenticular lens is difficult because it requires optically complex calculations. 2D-3D conversion is also impossible due to the fixed shape of the lenticular lens. Electrowetting based liquid lenticular lens has a simple fabrication process compared to the solid lenticular lens and the focal length of the liquid lenticular lens can be changed by applying the voltage. 3D and 2D images can be observed with a convex and a flat lens state respectively. Despite these advantages, the electrowetting based liquid lenticular lens demands high driving voltage and low breakdown voltage with a single dielectric layer structure. A certain degree of thickness of the dielectric layer is essential for a uniform operation and a low degradation over time. This paper presents multilayer dielectric structure which results in low driving voltage and the enhanced dielectric breakdown. Aluminum oxide (Al2O3), silicon oxide (SiO2) and parylene C were selected as the multilayer insulators. The total thickness of the dielectric layer of all samples was the same. This method using the multilayer dielectric structure can achieve the lower operating voltage than when using the single dielectric layer. We compared the liquid lenticular lens with three kinds of the multilayer dielectric structure to one with the parylene C single dielectric layer in regard to operational characteristics such as the driving voltage and the dielectric breakdown.

Annular folded electrowetting liquid lens.

PubMed

Li, Lei; Liu, Chao; Ren, Hongwen; Deng, Huan; Wang, Qiong-Hua

2015-05-01

We report an annular folded electrowetting liquid lens. The front surface of the lens is coated with a circular reflection film, while the back surface of the lens is coated with a ring-shaped reflection film. This approach allows the lens to get optical power from the liquid-liquid interface three times so that the optical power is tripled. An analysis of the properties of the annular folded electrowetting liquid lens is presented along with the design, fabrication, and testing of a prototype. Our results show that the optical power of the proposed liquid lens can be enhanced from ∼20.1 to ∼50.2  m(-1) in comparison with that of the conventional liquid lens (aperture ∼3.9  mm). It can reduce the operating voltage by ∼10  V to reach the same diopter as a conventional liquid lens. Our liquid lens has the advantages of compact structure, light weight, and improved optical resolution.

Analysis of Drop Shapes during Electrowetting on a Dielectric

NASA Astrophysics Data System (ADS)

Daneshbod, Yousef

2005-03-01

Electrowetting refers to the electrostatic control of the interfacial energy of a liquid on a solid, primarily used for the transport of micro-liter volumes of drops on surfaces with embedded electrode arrays. In the present work, the drop is modeled as a two-dimensional lens-like conductor immersed in an infinite dielectric medium slightly above a planar conductor. A matched asymptotic expansion is used to approximate the electrostatic field surrounding the drop. The outer problem models the drop as a conducting circular segment resting on the conducting plane, each maintained at a separate constant potential. The inner problem corrects the region near the edge of the drop by modeling it as an infinite planar conducting wedge lying slightly above the conducting plane. By matching the inner and outer solutions, the charge density along the entire surface of the drop can be approximated, enabling the calculation of the total capacitance of the system. An energy minimization method similar to that of Shapiro et al. [J. Appl. Phys., 93, 5794 (2003)] is applied to the total energy consisting of the liquid/gas, liquid/solid and solid/gas surface energies, together with the electrostatic contribution, subject to the constraint that the drop volume remains constant. A modified form of the Young-Lippmann equation is thus derived that includes the contribution from the extra capacitance of the drop obtained via matched asymptotics.

Temperature compensation analysis of liquid lens for variable-focus control

NASA Astrophysics Data System (ADS)

Chen, Shu-Jung; Tai, Tsai-Lin; Shen, Chih-Hsiung

2006-01-01

In this work, a fabrication and temperature compensation analysis and electrowetting for the liquid lenses is proposed. The unique capability of controlling the lens profile during the electrowetting fabrication processes is successfully demonstrated for different ambient temperature environment. For a lens fabricated on a hydrophobic Teflon layer, it is found that when the applied voltage is increased, the focal length increases, and the curvature decreases. One challenge for the liquid lens is operating temperature range. Due to the environment temperature change, the ability of controlling the lens profile is analyzed and measured. The description of change in contact angle corresponding to the variation of ambient temperature is derived. Based on this description, we firstly derive the control of voltage vs. temperature for a fixed dioptric power. The control of lens during a focusing action was studied by observation of the image formed by the light through the transparent bottom of ITO glass. Under several conditions of ambient temperature change, capability of controlling the lens profile for a fixed focus is successfully demonstrated by experiments.

Fabrication and Characterization of Flexible Electrowetting on Dielectrics (EWOD) Microlens

PubMed Central

Li, Chenhui; Jiang, Hongrui

2014-01-01

We present a flexible variable-focus converging microlens actuated by electrowetting on dielectric (EWOD). The microlens is made of two immiscible liquids and a soft polymer, polydimethylsiloxane (PDMS). Parylene intermediate layer is used to produce robust flexible electrode on PDMS. A low-temperature PDMS-compatible fabrication process has been developed to reduce the stress on the lens structure. The lens has been demonstrated to be able to conform to curved surfaces smoothly. The focal length of the microlens is 29–38 mm on a flat surface, and 31–41 mm on a curved surface, varying with the voltage applied. The resolving power of the microlens is 25.39 line pairs per mm by a 1951 United States Air Force (USAF) resolution chart and the lens aberrations are measured by a Shack-Hartmann wavefront sensor. The focal length behavior on a curved surface is discussed and for the current lens demonstrated the focal length is slightly longer on the curved surface as a result of the effect of the curved PDMS substrate. PMID:25360324

Energy harvesting from human motion: materials and techniques.

PubMed

Invernizzi, F; Dulio, S; Patrini, M; Guizzetti, G; Mustarelli, P

2016-10-10

Energy harvesting from human motion is a research field under rapid development. In this tutorial review we address the main physical and physico-chemical processes which can lead to energy generation, including electromagnetism, piezoelectricity, and electrostatic generation. Emphasis is put on the relationships among material properties and device efficiency. Some new and relatively less known approaches, such as triboelectric nanogeneration (TENG) and reverse electrowetting (REWOD), are reported in more detail.

Elasticity modulated Electrowetting of a sessile liquid droplet

NASA Astrophysics Data System (ADS)

Kumar, Sumit; Subramanian, Sri Ganesh; Dasgupta, Sunando; Chakraborty, Suman

2017-11-01

The sessile liquid droplets on the elastic and soft deformable surface produce strong deformation near the three-phase contact line (TPCL). The capillary and elastic forces play an important role during this deformation, and deteriorate the wetting behaviour of a sessile drop. The present work combines the effects of liquid viscosity and substrate elasticity on the dynamics of EWOD. The influence of decreasing film elasticity and viscosity on the electrowetting response of a sessile drop is experimentally investigated by delineating the changes in equilibrium apparent contact angles on substrates with varying Young's modulus of elasticity. The increase in viscosity of the liquid leads to greater electrowetting for non-deformable substrates whereas; the dynamics are not greatly affected in case of soft substrates. Although the viscosity appears to be an influential factor, the dynamics are more skewed towards the substrate rigidity. The vertical component of Young's force creates a wetting ridge at the three-phase contact line, the height of which is a direct function of the substrate rigidity. The produced ridges reduce the overall wettability of the droplet.

Fluidic lens of floating oil using round-pot chamber based on electrowetting.

PubMed

Choi, Hyunhwan; Won, Yonghyub

2013-07-01

This study presents a liquid lens using electrowetting that employs an oil phase floating in between the conducting fluids. The lens shape has double-sided surfaces and operates with a bias of 0-60 V. The focal length of the lens, with an aperture size of 2 mm, is ~5.8 mm, and it is converted into an optical power of 172. The lens is sufficient to suppress the fluctuation of fluids due to the external vibration. An image seen through the lens clearly resolves the element better than 6.35 LP/mm on USAF 1951 1×.

Electrowetting based infrared lens using ionic liquids

NASA Astrophysics Data System (ADS)

Hu, Xiaodong; Zhang, Shiguo; Liu, Yu; Qu, Chao; Lu, Liujin; Ma, Xiangyuan; Zhang, Xiaoping; Deng, Youquan

2011-11-01

We demonstrated an infrared variable focus ionic liquids lens using electrowetting, which could overcome the problems caused by use of water, e.g., evaporation and poor thermostability, while keeping good optical transparency in visible light and near-infrared region. Besides, the type of lens (convex or concave) could be tuned by applied voltage or refractive index of ILs used, and the transmittance was measured to exceed 90% over the spectrum of visible light and near-infrared. We believe this infrared variable focus ionic liquids lens has a great application prospect in both visible light and infrared image systems.

Contact line friction of electrowetting actuated viscous droplets

NASA Astrophysics Data System (ADS)

Vo, Quoc; Tran, Tuan

2018-06-01

We examine the contact line friction coefficient of viscous droplets spreading and retracting on solid surfaces immersed in ambient oil. By using the electrowetting effect, we generate a surface tension imbalance to drive the spreading and the retracting motion of the three-phase contact line (TCL). We show that neither the driving force intensity nor TCL direction significantly influences the friction coefficient. Instead, the friction coefficient depends equivalently on the viscosity of liquid droplets and the surrounding oil. We derive and experimentally verify a transient timescale that can be used to characterize both the spreading and retracting dynamics.

Electrowetting for Digital Microfluidics

NASA Astrophysics Data System (ADS)

Hunt, Tom; Adamson, Kristi; Issadore, David; Westervelt, Robert

2006-03-01

Droplet based chemistry promises to greatly impact biomedical research, providing new avenues for high throughput, low volume assays such as drug screening. Electrowetting on Dielectric (EWOD) is an excellent technique for manipulating microscopic drops of liquid. EWOD uses buried electrodes to locally change the surface energy between a droplet and a substrate. We present microfabricated devices for moving droplets with EWOD. One example of such a device consists of a series of 16 interdigitated electrodes, decreasing in size from 1mm to 20 microns. Each electrode is addressable by an independent, computer controlled, high voltage supply. This work made possible by a gift from Phillip Morris and the NSEC NSF grant PHY-0117795.

Improving the performance of an electrowetting lenticular lens array by using a thin polycarbonate chamber.

PubMed

Lee, Junsik; Kim, Junoh; Kim, Cheoljoong; Shin, Dooseub; Koo, Gyohyun; Sim, Jee Hoon; Won, Yong Hyub

2016-12-26

In this paper, we used a thin polycarbonate (PC) chamber to improve the performance of an electrowetting lenticular lens array. The polycarbonate chamber changed the radius of curvature (ROC) of the oil acting as a lens, which increased the dioptric power of the liquid lens to 1666.7D. The increase in dioptric power required a reduction in the distance between the optical center of the lens and the display pixels under the chamber, which was accomplished by reducing the thickness of the chamber. The optimal thickness of the chamber was determined to be 0.5mm. Using this thin PC chamber, transmittance and viewing angle were measured and compared with an electrowetting lenticular lens with a conventional 1mm poly methyl methacrylate (PMMA) chamber was done. Crosstalk which degrades clear 3D images, is an inevitable factor in lenticular lens type multi-view systems. With the 0.5mm PC chamber, the viewing zone was expanded and the ratio of the crosstalk area was reduced, which resulted in a clear 3D image. The new method of depositing the electrode layer also ensured the uniform operation of the liquid lens array.

Video-speed electronic paper based on electrowetting

NASA Astrophysics Data System (ADS)

Hayes, Robert A.; Feenstra, B. J.

2003-09-01

In recent years, a number of different technologies have been proposed for use in reflective displays. One of the most appealing applications of a reflective display is electronic paper, which combines the desirable viewing characteristics of conventional printed paper with the ability to manipulate the displayed information electronically. Electronic paper based on the electrophoretic motion of particles inside small capsules has been demonstrated and commercialized; but the response speed of such a system is rather slow, limited by the velocity of the particles. Recently, we have demonstrated that electrowetting is an attractive technology for the rapid manipulation of liquids on a micrometre scale. Here we show that electrowetting can also be used to form the basis of a reflective display that is significantly faster than electrophoretic displays, so that video content can be displayed. Our display principle utilizes the voltage-controlled movement of a coloured oil film adjacent to a white substrate. The reflectivity and contrast of our system approach those of paper. In addition, we demonstrate a colour concept, which is intrinsically four times brighter than reflective liquid-crystal displays and twice as bright as other emerging technologies. The principle of microfluidic motion at low voltages is applicable in a wide range of electro-optic devices.

High-speed droplet actuation on single-plate electrode arrays.

PubMed

Banerjee, Arghya Narayan; Qian, Shizhi; Joo, Sang Woo

2011-10-15

This paper reports a droplet-based microfluidic device composed of patterned co-planar electrodes in an all-in-a-single-plate arrangement and coated with dielectric layers for electrowetting-on-dielectric (EWOD) actuation of discrete droplets. The co-planar arrangement is preferred over conventional two-plate electrowetting devices because it provides simpler manufacturing process, reduced viscous drag, and easier liquid-handling procedures. These advantages lead to more versatile and efficient microfluidic devices capable of generating higher droplet speed and can incorporate various other droplet manipulation functions into the system for biological, sensing, and other microfluidic applications. We have designed, fabricated, and tested the devices using an insulating layer with materials having relatively high dielectric constant (SiO(2)) and compared the results with polymer coatings (Cytop) with low dielectric constant. Results show that the device with high dielectric layer generates more reproducible droplet transfer over a longer distance with a 25% reduction in the actuation voltage with respect to the polymer coatings, leading to more energy efficient microfluidic applications. We can generate droplet speeds as high as 26 cm/s using materials with high dielectric constant such as SiO(2). Copyright © 2011. Published by Elsevier Inc.

Low Voltage Electrowetting-on-Dielectric Platform using Multi-Layer Insulators

PubMed Central

Lin, Yan-You; Evans, Randall D.; Welch, Erin; Hsu, Bang-Ning; Madison, Andrew C.; Fair, Richard B.

2010-01-01

A low voltage, two-level-metal, and multi-layer insulator electrowetting-on-dielectric (EWD) platform is presented. Dispensing 300pl droplets from 140nl closed on-chip reservoirs was accomplished with as little as 11.4V solely through EWD forces, and the actuation threshold voltage was 7.2V with a 1Hz voltage switching rate between electrodes. EWD devices were fabricated with a multilayer insulator consisting of 135nm sputtered tantalum pentoxide (Ta2O5) and 180nm parylene C coated with 70nm of CYTOP. Furthermore, the minimum actuation threshold voltage followed a previously published scaling model for the threshold voltage, VT, which is proportional to (t/εr)1/2, where t and εr are the insulator thickness and dielectric constant respectively. Device threshold voltages are compared for several insulator thicknesses (200nm, 500nm, and 1µm), different dielectric materials (parylene C and tantalum pentoxide), and homogeneous versus heterogeneous compositions. Additionally, we used a two-level-metal fabrication process, which enables the fabrication of smaller and denser electrodes with high interconnect routing flexibility. We also have achieved low dispensing and actuation voltages for scaled devices with 30pl droplets. PMID:20953362

Activation and control of microlens liquid arrays on functionalized polar electric crystal substrates by electro-wetting effect and temperature

NASA Astrophysics Data System (ADS)

Ferraro, Pietro; Grilli, Simonetta; Miccio, Lisa; Vespini, Veronica; Finizio, Sergio DeNicola Andrea

2008-11-01

In recent years a variety of liquid bases optical elements have been conceived, designed and fabricated even for commercial products like digital cameras o cellular phone cameras. The impressive development of microfluidic systems in conjunction with optics has led to the creation of a completely new Science field of investigation named optofludics. Optofludics, among others topics, deals with investigation and methods for realizing liquid micro-lenses. A variety of liquid micro-lenses have been designed and realized by using different configurations. We demonstrate that a lensing effect can be obtained in an open microfluidic system by using a thin layer of liquid on a polar electric crystal such as Lithium Niobate (LiNbO3). Electrowetting patterning on LiNbO3 surface is obtained by pyroelectric effect consisting in a simple but reliable electrodes-less and circuit-less configuration. The electrodes are intrinsically embedded into the substrate. The material is functionalised by means of a micro-engineering electric filed poling process. Lens array with variable focus has been demonstrated with a large number of lens elements (10x10) on micrometric scale (aperture of single lens 100 microns).

Droplet Translation Actuated by Photoelectrowetting.

PubMed

Palma, Cesar; Deegan, Robert D

2018-03-13

In traditional electrowetting-on-dielectric (EWOD) devices, droplets are moved about a substrate using electric fields produced by an array of discrete electrodes. In this study, we show that a drop can be driven across a substrate with a localized light beam by exploiting the photoelectrowetting (PEW) effect, a light-activated variant of EWOD. Droplet transport actuated by PEW eliminates the need for electrode arrays and the complexities entailed in their fabrication and control, and offers a new approach for designing lab-on-a-chip applications. We report measurements of the maximum droplet speed as a function of frequency and magnitude of the applied bias, intensity of illumination, volume of the droplet, and viscosity and also introduce a model that reproduces these data.

Area-tunable micromirror based on electrowetting actuation of liquid-metal droplets

NASA Astrophysics Data System (ADS)

Wan, Zhiliang; Zeng, Hongjun; Feinerman, Alan

2006-11-01

The authors report a micromirror device actuated by electrowetting effect. The micromirror surface is formed by a liquid-metal droplet jetted on a substrate and then topped with a parylene/Teflon coated indium tin oxide glass slide. The droplet is deformed by a voltage applied across the parylene/Teflon film. The radius of micromirror is tuned from 13μm (0V) to 88μm (90V), and the normalized area increases from 0.2 to 0.94 accordingly. The switching time ranges from 1ms for a 350μm diameter droplet to 0.2ms for a 50μm one. A 4×1 micromirror array is demonstrated and switched simultaneously.

Electrowetting retroreflectors: Scalable and wide-spectrum modulation between corner cube and scattering reflection

NASA Astrophysics Data System (ADS)

Kilaru, M. K.; Cumby, B.; Heikenfeld, J.

2009-01-01

Corner cube and spherical retroreflectors are ubiquitous in conspicuity and range-finding applications since they reflect light back to the illumination source with unmatched efficiency. We report here a switchable electrowetting retroreflector platform that provides multiple novel features, including (a) using <0.5 μJ/cm2 electrical energy to switch from a light scattering state, (b) low loss and wide spectrum as limited only by the absorption spectrum of water, (c) use of ultrasimple self-assembly of 103-105 liquid lenslets/in.2 on a polymer/Al corner-cube substrate, and (d) change in retroreflected irradiance of >10:1 over a ±30° field of view.

Improvement of Varioptic's liquid lens based on electrowetting: how to obtain a short response time and its application in the design of a high resolution iris biometric system

NASA Astrophysics Data System (ADS)

Burger, Benjamin; Meimon, Serge C.; Petit, Cyril; Nguyen, Minh Chau

2015-02-01

This communication presents the results obtained for decreasing the response time of electrowetting-based real time focus correctors (liquid lenses). In order to provide a compact iris biometric system demonstrator, we have achieved a response time at 90% of 7.5 ms for a change in focalization from 0 diopter to 10 diopter with a liquid lens having an aperture of 1.9 mm. We have used a hydrodynamic fluid reorganization model to predict the features of these fast liquid lenses and evaluated the sensivity of the response time to the different conception parameters.

Field-Assisted Contact Line Motion in Thin Films.

PubMed

Ghosh, Udita Uday; DasGupta, Sunando

2018-04-25

The balance of intermolecular and surface forces plays a critical role in the transport phenomena near the contact line region of an extended meniscus in several technologically important processes. Externally applied fields can alter the equilibrium and stability of the meniscus with concomitant effects on its shape and spreading characteristics and may even lead to an oscillation. This feature article provides a detailed account of the present and past efforts in exploring the behavior of curved thin liquid films subjected to mild thermal perturbations, heat input, and electrical and magnetic fields for pure as well as colloidal suspensions, including the effects of particle charge and polarity. The shape-dependent intermolecular force field has been evaluated in situ by a nonobtrusive optical technique utilizing the interference phenomena and subsequent image processing. The critical role of disjoining pressure is identified along with the determination of the Hamaker constant. The spatial and temporal variations of the capillary forces are evaluated for the advancing and receding menisci. The Maxwell-stress-induced enhanced spreading during electrowetting, at relatively low voltages, and that due to the application of a magnetic field are discussed with respect to their distinctly different characteristics and application potentials. The use of the augmented Young-Laplace equation elicited additional insights into the fundamental physics for flow in ultrathin liquid films.

High-performance beam steering using electrowetting-driven liquid prism fabricated by a simple dip-coating method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Enrico Clement, Carlos; Park, Sung-Yong, E-mail: mpeps@nus.edu.sg

2016-05-09

A high degree of beam steering is demonstrated using an electrowetting-driven liquid prism. While prism devices have typically relied on complex and expensive laboratory setups, such as high-vacuum facilities for fabrication of dielectric layers, this work utilizes a simple dip-coating method to provide an ion gel layer as a dielectric, offering 2 or 3 orders higher specific capacitance (c ≈ 10 μF/cm{sup 2}) than that of conventional dielectrics. Analytical studies present the effects of liquid selection and arrangement on overall prism performance. For experimental demonstrations of high-performance beam steering, we not only selected two immiscible liquids of water and 1-bromonaphthalene (1-BN)more » oil which provide the large refractive index difference (n{sub water} = 1.33 and n{sub 1-BN} = 1.65 at λ = 532 nm) between them, but also utilized a double-stacked prism configuration which increases the number of interfaces for incoming light to be steered. At a prism apex angle of φ = 27°, we were able to achieve significantly large beam steering of up to β = 19.06°, which is the highest beam steering performance ever demonstrated using electrowetting technology.« less

Microparticle sampling by electrowetting-actuated droplet sweeping.

PubMed

Zhao, Yuejun; Cho, Sung Kwon

2006-01-01

This paper describes a new microparticle sampler where particles can be efficiently swept from a solid surface and sampled into a liquid medium using moving droplets actuated by the electrowetting principle. We successfully demonstrate that super hydrophilic (2 microm and 7.9 microm diameter glass beads of about 14 degrees contact angle), intermediate hydrophilic (7.5 microm diameter polystyrene beads of about 70 degrees contact angle), and super hydrophobic (7.9 microm diameter Teflon-coated glass beads and 3 microm size PTFE particles of over 110 degrees contact angles) particles on a solid surface are picked up by electrowetting-actuated moving droplets. For the glass beads as well as the polystyrene beads, the sampling efficiencies are over 93%, in particular over 98% for the 7.9 microm glass beads. For the PTFE particles, however, the sampling efficiency is measured at around 70%, relatively lower than that of the glass and polystyrene beads. This is due mainly to the non-uniformity in particle size and the particle hydrophobicity. In this case, the collected particles staying (adsorbing) on the air-to-water interface hinder the droplet from advancing. This particle sampler requires an extremely small amount of liquid volume (about 500 nanoliters) and will thus be highly compatible and easily integrated with lab-on-a-chip systems for follow-up biological/chemical analyses.

Multi-scale strategies for dealing with moving contact lines

NASA Astrophysics Data System (ADS)

Smith, Edward R.; Theodorakis, Panagiotis; Craster, Richard V.; Matar, Omar K.

2017-11-01

Molecular dynamics (MD) has great potential to elucidate the dynamics of the moving contact line. As a more fundamental model, it can provide a priori results for fluid-liquid interfaces, surface tension, viscosity, phase change, and near wall stick-slip behaviour which typically show very good agreement to experimental results. However, modelling contact line motion combines all this complexity in a single problem. In this talk, MD simulations of the contact line are compared to the experimental results obtained from studying the dynamics of a sheared liquid bridge. The static contact angles are correctly matched to the experimental data for a range of different electro-wetting results. The moving contact line results are then compared for each of these electro-wetting values. Despite qualitative agreement, there are notable differences between the simulation and experiments. Many MD simulation have studied contact lines, and the sheared liquid bridge, so it is of interest to review the limitations of this setup in light of this discrepancy. A number of factors are discussed, including the inter-molecular interaction model, molecular-scale surface roughness, model of electro-wetting and, perhaps most importantly, the limited system sizes possible using MD simulation. EPSRC, UK, MEMPHIS program Grant (EP/K003976/1), RAEng Research Chair (OKM).

Interferometric characterization of pyroelectrically activated micro-arrays of liquid lenses in lithium niobate crystals

NASA Astrophysics Data System (ADS)

Grilli, S.; Miccio, L.; Vespini, V.; Ferraro, P.

2008-08-01

In recent years a wide variety of liquid based optical elements have been conceived, designed and fabricated even for commercial products like digital cameras. The impressive development of microfluidic systems in conjunction with optics has led to the creation of a completely new field of investigation named optofludics. Among other things, the optofluidic area deals with the investigation and the realization of liquid micro-lenses. Different methods and configurations have been proposed in literature to achieve liquid variable micro-lenses. This paper reports about the possibility to achieve lensing effect by a relatively easy to accomplish technique based on an open microfluidic system consisting of a tiny amount of appropriate liquid manipulated by the pyroelectric effect onto a periodically poled LiNbO3 substrate. Basically, an electrowetting process is performed to actuate the liquid film by using the surface charges generated pyroelectrically under temperature variation. The configuration is electrode-less compared to standard electrowetting systems, thus improving the device flexibility and easiness of fabrication. The curvature of the liquid lenses has been characterized by interferometric techniques based on the evaluation of the phase map through digital holography. The results showing the evolution of the lens curvature with the temperature variation will be presented and discussed.

Two liquids wetting and low hysteresis electrowetting on dielectric applications.

PubMed

Maillard, Mathieu; Legrand, Julien; Berge, Bruno

2009-06-02

This study focuses on electrowetting using two immmiscible liquids on a dielectric coating. It is demonstrated that low contact angle of oil on the hydrophobic surfaces is a key parameter to obtain a low hysteresis system, below 2 degrees . On the basis of these results, three aspects of the wetting properties have been studied: the influence of the surface hydrophobic properties, the design of the liquids according to the hydrophobic surface, and a graphical method to solve the Bartell-Osterhof equation and predict the wetting properties of two liquids on a surface. These results define clear design rules to obtain a low hysteresis system, useful for many applications from liquid lenses to displays and laboratory-on-a-chip.

Numerical analysis of wavefront aberration correction using multielectrode electrowetting-based devices.

PubMed

Zohrabi, Mo; Cormack, Robert H; Mccullough, Connor; Supekar, Omkar D; Gibson, Emily A; Bright, Victor M; Gopinath, Juliet T

2017-12-11

We present numerical simulations of multielectrode electrowetting devices used in a novel optical design to correct wavefront aberration. Our optical system consists of two multielectrode devices, preceded by a single fixed lens. The multielectrode elements function as adaptive optical devices that can be used to correct aberrations inherent in many imaging setups, biological samples, and the atmosphere. We are able to accurately simulate the liquid-liquid interface shape using computational fluid dynamics. Ray tracing analysis of these surfaces shows clear evidence of aberration correction. To demonstrate the strength of our design, we studied three different input aberrations mixtures that include astigmatism, coma, trefoil, and additional higher order aberration terms, with amplitudes as large as one wave at 633 nm.

Effect of oil liquid viscosity on hysteresis in double-liquid variable-focus lens based on electrowetting

NASA Astrophysics Data System (ADS)

Zeng, Zhi; Peng, Runling; He, Mei

2017-02-01

The double-liquid variable-focus lens based on the electrowetting has the characteristics of small size, light weight, fast response, and low price and so on. In this paper, double-liquid variable-focus lens's Principle and structure are introduced. The reasons for the existence and improvement of contact angle hysteresis are given according improved Young's equation. At last, 1-Bromododecane with silicone oil are mixed to get oil liquid with different viscosity and proportion liquid as insulating liquid. External voltages are applied to these three liquid lens and focal lengths of the lenses versus applied voltage are investigated. Experiments show that, the decreasing of oil liquid viscosity can reduce focal length hysteresis.

Research and development on the construction of 2D light-driven droplet manipulation platform based on light modulation of TiOPc impedance

NASA Astrophysics Data System (ADS)

Chen, Yi-Chen; Chen, Ho-Tsung; Lee, Chih-Kung

2014-03-01

The newly developed configuration included adopting the photosensitive electrode material TiOPc (titanyl phthalocyanine) to create electrowetting on dielectric (EWOD) mechanism. With this new development, the electric potential on the surface of TiOPc could be on-line real-time changed and defined spatially by illuminating spatially distributed light beam patterns. We tried to control the polarized droplets in our EWOD devices by using different light intensities. The experimental results clearly demonstrated that the relationship of light intensity and electrowetting phenomena can provide us with a feasible platform to construct optofluidic chip with potential autonomous manipulation of samples for point-of-care home medical detection applications.

Wetting of flat gradient surfaces.

PubMed

Bormashenko, Edward

2018-04-01

Gradient, chemically modified, flat surfaces enable directed transport of droplets. Calculation of apparent contact angles inherent for gradient surfaces is challenging even for atomically flat ones. Wetting of gradient, flat solid surfaces is treated within the variational approach, under which the contact line is free to move along the substrate. Transversality conditions of the variational problem give rise to the generalized Young equation valid for gradient solid surfaces. The apparent (equilibrium) contact angle of a droplet, placed on a gradient surface depends on the radius of the contact line and the values of derivatives of interfacial tensions. The linear approximation of the problem is considered. It is demonstrated that the contact angle hysteresis is inevitable on gradient surfaces. Electrowetting of gradient surfaces is discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

Droplet-based pyrosequencing using digital microfluidics.

PubMed

Boles, Deborah J; Benton, Jonathan L; Siew, Germaine J; Levy, Miriam H; Thwar, Prasanna K; Sandahl, Melissa A; Rouse, Jeremy L; Perkins, Lisa C; Sudarsan, Arjun P; Jalili, Roxana; Pamula, Vamsee K; Srinivasan, Vijay; Fair, Richard B; Griffin, Peter B; Eckhardt, Allen E; Pollack, Michael G

2011-11-15

The feasibility of implementing pyrosequencing chemistry within droplets using electrowetting-based digital microfluidics is reported. An array of electrodes patterned on a printed-circuit board was used to control the formation, transportation, merging, mixing, and splitting of submicroliter-sized droplets contained within an oil-filled chamber. A three-enzyme pyrosequencing protocol was implemented in which individual droplets contained enzymes, deoxyribonucleotide triphosphates (dNTPs), and DNA templates. The DNA templates were anchored to magnetic beads which enabled them to be thoroughly washed between nucleotide additions. Reagents and protocols were optimized to maximize signal over background, linearity of response, cycle efficiency, and wash efficiency. As an initial demonstration of feasibility, a portion of a 229 bp Candida parapsilosis template was sequenced using both a de novo protocol and a resequencing protocol. The resequencing protocol generated over 60 bp of sequence with 100% sequence accuracy based on raw pyrogram levels. Excellent linearity was observed for all of the homopolymers (two, three, or four nucleotides) contained in the C. parapsilosis sequence. With improvements in microfluidic design it is expected that longer reads, higher throughput, and improved process integration (i.e., "sample-to-sequence" capability) could eventually be achieved using this low-cost platform.

Droplet-Based Pyrosequencing Using Digital Microfluidics

PubMed Central

Boles, Deborah J.; Benton, Jonathan L.; Siew, Germaine J.; Levy, Miriam H.; Thwar, Prasanna K.; Sandahl, Melissa A.; Rouse, Jeremy L.; Perkins, Lisa C.; Sudarsan, Arjun P.; Jalili, Roxana; Pamula, Vamsee K.; Srinivasan, Vijay; Fair, Richard B.; Griffin, Peter B.; Eckhardt, Allen E.; Pollack, Michael G.

2013-01-01

The feasibility of implementing pyrosequencing chemistry within droplets using electrowetting-based digital microfluidics is reported. An array of electrodes patterned on a printed-circuit board was used to control the formation, transportation, merging, mixing, and splitting of submicroliter-sized droplets contained within an oil-filled chamber. A three-enzyme pyrosequencing protocol was implemented in which individual droplets contained enzymes, deoxyribonucleotide triphosphates (dNTPs), and DNA templates. The DNA templates were anchored to magnetic beads which enabled them to be thoroughly washed between nucleotide additions. Reagents and protocols were optimized to maximize signal over background, linearity of response, cycle efficiency, and wash efficiency. As an initial demonstration of feasibility, a portion of a 229 bp Candida parapsilosis template was sequenced using both a de novo protocol and a resequencing protocol. The resequencing protocol generated over 60 bp of sequence with 100% sequence accuracy based on raw pyrogram levels. Excellent linearity was observed for all of the homopolymers (two, three, or four nucleotides) contained in the C. parapsilosis sequence. With improvements in microfluidic design it is expected that longer reads, higher throughput, and improved process integration (i.e., “sample-to-sequence” capability) could eventually be achieved using this low-cost platform. PMID:21932784

Effect of Electric Field on the Wetting Behavior of Eutectic Gallium-Indium Alloys in Aqueous Environment

NASA Astrophysics Data System (ADS)

Yuan, Bo; He, Zhi-Zhu; Liu, Jing

2018-02-01

Room-temperature liquid metals have many intriguing properties that have not previously been fully understood. Among them, surface tension behaviors of such metals are especially critical in a group of newly emerging areas such as printed electronics, functional materials and soft machines, etc. This study is dedicated to clarifying the wettability of liquid metals on various substrate surfaces with varied roughness immersed in solutions when subject to an electric field. The contact angles of Ga75.5In24.5 in several typical liquids were comprehensively measured and interpreted, and were revealed to be affected by the components and concentration of the environmental solution. Meanwhile, the roughness of the substrates is also revealed to be an important parameter dominating the process. The dynamic wetting behaviors of liquid metal in aqueous environment under an electric field were quantified. The contact angle values of eutectic gallium-indium alloys (eGaIn) on titanium substrates with different roughness would lead to better electrowetting performances on rougher surfaces. In particular, using an electrical field to control the wetting status of liquid metal with the matching substrate have been illustrated, which would offer a practical way to flexibly control liquid metal-based functional devices working in an aqueous environment. Furthermore, Lippmann-Young's equation reveals the relationship between contact angle and applied voltage, explaining the excellent electrowetting property of eGaIn. The power law, R = αt β , was adopted to characterize the two-stage wetting process of eGaIn under different voltages. In the initial process, β ≈ 1/2 represents the complete wetting law, while the later one, β ≈ 1/10, meets with Tanner's law of a drop spontaneously spreading on a smooth surface.

Breath Figures under Electrowetting: Electrically Controlled Evolution of Drop Condensation Patterns

NASA Astrophysics Data System (ADS)

Baratian, Davood; Dey, Ranabir; Hoek, Harmen; van den Ende, Dirk; Mugele, Frieder

2018-05-01

We show that electrowetting (EW) with structured electrodes significantly modifies the distribution of drops condensing onto flat hydrophobic surfaces by aligning the drops and by enhancing coalescence. Numerical calculations demonstrate that drop alignment and coalescence are governed by the drop-size-dependent electrostatic energy landscape that is imposed by the electrode pattern and the applied voltage. Such EW-controlled migration and coalescence of condensate drops significantly alter the statistical characteristics of the ensemble of droplets. The evolution of the drop size distribution displays self-similar characteristics that significantly deviate from classical breath figures on homogeneous surfaces once the electrically induced coalescence cascades set in beyond a certain critical drop size. The resulting reduced surface coverage, coupled with earlier drop shedding under EW, enhances the net heat transfer.

Ultrathin zoom telescopic objective.

PubMed

Li, Lei; Wang, Di; Liu, Chao; Wang, Qiong-Hua

2016-08-08

We report an ultrathin zoom telescopic objective that can achieve continuous zoom change and has reduced compact volume. The objective consists of an annular folded lens and three electrowetting liquid lenses. The annular folded lens undertakes the main part of the focal power of the lens system. Due to a multiple-fold design, the optical path is folded in a lens with the thickness of ~1.98mm. The electrowetting liquid lenses constitute a zoom part. Based on the proposed objective, an ultrathin zoom telescopic camera is demonstrated. We analyze the properties of the proposed objective. The aperture of the proposed objective is ~15mm. The total length of the system is ~18mm with a tunable focal length ~48mm to ~65mm. Compared with the conventional zoom telescopic objective, the total length has been largely reduced.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rajkumar, K.; Rajavel, K.; Cameron, D. C.

This paper reports the electrowetting properties of liquid droplet on superhydrophobic silicon nanowires with Atomic layer deposited (ALD) Al{sub 2}O{sub 3} as dielectric layer. Silicon wafer were etched by metal assisted wet chemical etching with silver as catalyst. ALD Al{sub 2}O{sub 3} films of 10nm thickness were conformally deposited over silicon nanowires. Al{sub 2}O{sub 3} dielectric film coated silicon nanowires was chemically modified with Trichloro (1H, 1H, 2H, 2H-perfluorooctyl) silane to make it superhydrophobic(SHP). The contact angle was measured and all the samples exhibited superhydrophobic nature with maximum contact angles of 163° and a minimum contact angle hysteresis of 6°.more » Electrowetting induced a maximum reversible decrease of the contact angle of 20°at 150V in air.« less

Large membrane deflection via capillary force actuation

NASA Astrophysics Data System (ADS)

Barth, Christina A.; Hu, Xiaoyu; Mibus, Marcel A.; Reed, Michael L.; Knospe, Carl R.

2018-06-01

Experimental results from six prototype devices demonstrate that pressure changes induced in a liquid bridge via electrowetting can generate large deflections (20–75 µm) of an elastomeric membrane similar to those used in lab-on-a-chip microfluidic devices. In all cases deflections are obtained with a low voltage (20 V) and very small power consumption (<1 µW). The effects of variations in the bridge size and membrane dimensions on measured displacements are examined. Theoretical predictions are in good agreement with the measured displacements in those cases where the liquid contact angles could be measured within the devices during electrowetting. Contact angle hysteresis and charge injection into the dielectric layers limited the repeatability of deflection behavior during repeated cycling. Approaches for achieving greater deflections and improved repeatability are discussed.

Electrowetting-driven solar indoor lighting (e-SIL): an optofluidic approach towards sustainable buildings.

PubMed

Thio, Si Kuan; Jiang, Dongyue; Park, Sung-Yong

2018-06-12

Optofluidics is an emerging research field that combines the two disciplines of microfluidics and optics. By using microfluidic technologies for light control, optofluidic devices can offer several advantages over solid-type optical components, including optical-grade smoothness at the fluidic interface and a high degree of optical tunability without bulky and complex mechanical moving parts. These features have made optofluidic devices more versatile and reconfigurable to improve their optical performances. In this paper, we present a novel optofluidic sunlight manipulation technology for solar indoor lighting using the electrowetting principle. Rooftop sunlight is collected by a solar concentrator and guided to individual rooms along an optical fiber (waveguide) on the bottom of which tunable liquid prisms are linearly integrated. In the light-off mode, electrowetting controls the apex angle of the prisms to be φ = 0°. Under this condition, incoming sunlight experiences total internal reflection and thus keeps propagating along the optical fiber without leaking to the prism bottom for indoor lighting. In contrast, when liquid prisms are controlled to have the angle at φ > 0°, incoming sunlight is partially transmitted to the bottom surface of the arrayed prisms to contribute to interior illumination. Simulation studies validate that our electrowetting-driven solar indoor lighting (e-SIL) system is capable of variably tuning the lighting power from 0% to 98.6% of the input solar power by controlling the prism angle and varying the refractive index of prism materials. For experimental studies, we fabricated an array of 5 prisms filled with silicone oil and water. Using a fiber illuminator as a white light source that includes visible light with various incident angles, we have demonstrated two important lighting functions, (1) light on/off and (2) illumination power control. Lighting performance can be further enhanced by lowering the aspect ratio of the prism as well as increasing the number of prisms. The e-SIL technology based on tunable liquid prisms offers a new approach towards sustainable buildings that are able to reduce their electricity usage as well as provide a healthy and comfortable indoor environment under illumination of natural sunlight.

Is an electric field always a promoter of wetting? Electro-dewetting of metals by electrolytes probed by in situ X-ray nanotomography

DOE PAGES

Nave, Maryana I.; Gu, Yu; Karen Chen-Wiegart, Yu-Chen; ...

2017-01-05

We developed a special electrochemical cell enabling quantitative analysis andin situX-ray nanotomography of metal/electrolyte interfaces subject to corrosion. Using this cell and applying the nodoid model to describe menisci formed on tungsten wires during anodization, the evolution of the electrolyte surface tension, the concentration of reaction products, and the meniscus contact angle were studied. In contrast to the electrowetting effect, where the applied electric field decreases the contact angle of electrolytes, anodization of the tungsten wires increases the contact angle of the meniscus. Hence, an electric field favors dewetting rather than wetting of the newly formed surface. Finally, the discoveredmore » effect opens up new opportunities for the control of wetting phenomena and calls for the revision of existing theories of electrowetting.« less

Interfacial waves generated by electrowetting-driven contact line motion

NASA Astrophysics Data System (ADS)

Ha, Jonghyun; Park, Jaebum; Kim, Yunhee; Shin, Bongsu; Bae, Jungmok; Kim, Ho-Young

2016-10-01

The contact angle of a liquid-fluid interface can be effectively modulated by the electrowetting-on-dielectric (EWOD) technology. Rapid movement of the contact line can be achieved by swift changes of voltage at the electrodes, which can give rise to interfacial waves under the strong influence of surface tension. Here we experimentally demonstrate EWOD-driven interfacial waves of overlapping liquids and compare their wavelength and decay length with the theoretical results obtained by a perturbation analysis. Our theory also allows us to predict the temporal evolution of the interfacial profiles in either rectangular or cylindrical containers, as driven by slipping contact lines. This work builds a theoretical framework to understand and predict the dynamics of capillary waves of a liquid-liquid interface driven by EWOD, which has practical implications on optofluidic devices used to guide light.

Developing interface localized liquid dielectrophoresis for optical applications

NASA Astrophysics Data System (ADS)

McHale, Glen; Brown, Carl V.; Newton, Michael I.; Wells, Gary G.; Sampara, Naresh

2012-11-01

Electrowetting charges the solid-liquid interface to change the contact area of a droplet of a conducting liquid. It is a powerful technique used to create variable focus liquid lenses, electronic paper and other devices, but it depends upon ions within the liquid. Liquid dielectrophoresis (L-DEP) is a bulk force acting on the dipoles throughout a dielectric liquid and is not normally considered to be a localized effect acting at the interface between the liquid and a solid or other fluid. In this work, we show theoretically how non-uniform electric fields generated by interdigitated electrodes can effectively convert L-DEP into an interface localized form. We show that for droplets of sufficient thickness, the change in the cosine of the contact angle is proportional to the square of the applied voltage and so obeys a similar equation to that for electrowetting - this we call dielectrowetting. However, a major difference to electrowetting is that the strength of the effect is controlled by the electrode spacing and the liquid permittivity rather than the properties of an insulator in a sandwich structure. Experimentally, we show that that this dielectrowetting equation accurately describes the contact angle of a droplet of oil viewed across parallel interdigitated electrodes. Importantly, the induced spreading can be complete, such that contact angle saturation does not occur. We then show that for thin films, L-DEP can shape the liquid-air interface creating a spatially periodic wrinkle and that such a wrinkle can be used to create a voltage programmable phase diffraction grating.

Pitch variable liquid lens array using electrowetting

NASA Astrophysics Data System (ADS)

Kim, YooKwang; Lee, Jin Su; Kim, Junoh; Won, Yong Hyub

2017-02-01

These days micro lens array is used in various fields such as fiber coupling, laser collimation, imaging and sensor system and beam homogenizer, etc. One of important thing in using micro lens array is, choice of its pitch. Especially imaging systems like integral imaging or light-field camera, pitch of micro lens array defines the system property and thus it could limit the variability of the system. There are already researches about lens array using liquid, and droplet control by electrowetting. This paper reports the result of combining them, the liquid lens array that could vary its pitch by electrowetting. Since lens array is a repeated system, realization of a small part of lens array is enough to show its property. The lens array is composed of nine (3 by 3) liquid droplets on flat surface. On substrate, 11 line electrodes are patterned along vertical and horizontal direction respectively. The width of line electrodes is 300um and interval is 200um. Each droplet is positioned to contain three electrode lines for both of vertical and horizontal direction. So there is one remaining electrode line in each of outermost side for both direction. In original state the voltage is applied to inner electrodes. When voltage of outermost electrodes are turned on, eight outermost droplets move to outer side, thereby increasing pitch of lens array. The original pitch was 1.5mm and it increased to 2.5mm after electrodes of voltage applied is changed.

Electrowetting liquid lens array on curved substrates for wide field of view image sensor

NASA Astrophysics Data System (ADS)

Bang, Yousung; Lee, Muyoung; Won, Yong Hyub

2016-03-01

In this research, electrowetting liquid lens array on curved substrates is developed for wide field of view image sensor. In the conventional image sensing system, this lens array is usually in the form of solid state. However, in this state, the lens array which is similar to insect-like compound eyes in nature has several limitations such as degradation of image quality and narrow field of view because it cannot adjust focal length of lens. For implementation of the more enhanced system, the curved array of lenses based on electrowetting effect is developed in this paper, which can adjust focal length of lens. The fabrication of curved lens array is conducted upon the several steps, including chamber fabrication, electrode & dielectric layer deposition, liquid injection, and encapsulation. As constituent materials, IZO coated convex glass, UV epoxy (NOA 68), DI water, and dodecane are used. The number of lenses on the fabricated panel is 23 by 23 and each lens has 1mm aperture with 1.6mm pitch between adjacent lenses. When the voltage is applied on the device, it is observed that each lens is changed from concave state to convex state. From the unique optical characteristics of curved array of liquid lenses such as controllable focal length and wide field of view, we can expect that it has potential applications in various fields such as medical diagnostics, surveillance systems, and light field photography.

Development of adaptive liquid microlenses and microlens arrays

NASA Astrophysics Data System (ADS)

Berry, Shaun R.; Stewart, Jason B.; Thorsen, Todd A.; Guha, Ingrid

2013-03-01

We report on the development of sub-millimeter size adaptive liquid microlenses and microlens arrays using two immiscible liquids to form individual lenses. Microlenses and microlens arrays having aperture diameters as small as 50 microns were fabricated on a planar quartz substrate using patterned hydrophobic/hydrophilic regions. Liquid lenses were formed by a self-assembled oil dosing process that created well-defined lenses having a high fill factor. Variable focus was achieved by controlling the lens curvature through electrowetting. Greater than 70° of contact angle change was achieved with less than 20 volts, which results in a large optical power dynamic range.

Digital microfluidics-enabled single-molecule detection by printing and sealing single magnetic beads in femtoliter droplets.

PubMed

Witters, Daan; Knez, Karel; Ceyssens, Frederik; Puers, Robert; Lammertyn, Jeroen

2013-06-07

Digital microfluidics is introduced as a novel platform with unique advantages for performing single-molecule detection. We demonstrate how superparamagnetic beads, used for capturing single protein molecules, can be printed with unprecedentedly high loading efficiency and single bead resolution on an electrowetting-on-dielectric-based digital microfluidic chip by micropatterning the Teflon-AF surface of the device. By transporting droplets containing suspended superparamagnetic beads over a hydrophilic-in-hydrophobic micropatterned Teflon-AF surface, single beads are trapped inside the hydrophilic microwells due to their selective wettability and tailored dimensions. Digital microfluidics presents the following advantages for printing and sealing magnetic beads for single-molecule detection: (i) droplets containing suspended beads can be transported back and forth over the array of hydrophilic microwells to obtain high loading efficiencies of microwells with single beads, (ii) the use of hydrophilic-in-hydrophobic patterns permits the use of a magnet to speed up the bead transfer process to the wells, while the receding droplet meniscus removes excess beads off the chip surface and thereby shortens the bead patterning time, and (iii) reagents can be transported over the printed beads multiple times, while capillary forces and a magnet hold the printed beads in place. High loading efficiencies (98% with a CV of 0.9%) of single beads in microwells were obtained by transporting droplets of suspended beads over the array 10 times in less than 1 min, which is much higher than previously reported methods (40-60%), while the total surface area needed for performing single-molecule detection can be decreased. The performance of the device was demonstrated by fluorescent detection of the presence of the biotinylated enzyme β-galactosidase on streptavidin-coated beads with a linear dynamic range of 4 orders of magnitude ranging from 10 aM to 90 fM.

Contact angle hysteresis and oil film lubrication in electrowetting with two immiscible liquids

NASA Astrophysics Data System (ADS)

Gao, J.; Mendel, N.; Dey, R.; Baratian, D.; Mugele, F.

2018-05-01

Electrowetting (EW) of water drops in ambient oil has found a wide range of applications including lab-on-a-chip devices, display screens, and variable focus lenses. The efficacy of all these applications is dependent on the contact angle hysteresis (CAH), which is generally reduced in the presence of ambient oil due to thin lubrication layers. While it is well-known that AC voltage reduces the effective contact angle hysteresis (CAH) for EW in ambient air, we demonstrate here that CAH for EW in ambient oil increases with increasing AC and DC voltage. Taking into account the disjoining pressure of the fluoropolymer-oil-water system, short range chemical interactions, viscous oil entrainment, and electrostatic stresses, we find that this observation can be explained by progressive thinning of the oil layer underneath the drop with increasing voltage. This exposes the droplet to the roughness of the underlying solid and thereby increases hysteresis.

Electrowetting Controlled Tunable Liquid Microlens

NASA Astrophysics Data System (ADS)

Krupenkin, Tom; Yang, Shu

2002-03-01

Electrowetting potentially provides a convenient way to control the shape and position of the liquid droplet on a rigid substrate. However, the effectiveness of this method relies strongly on the precise control of the surface properties of the substrate. Here we present a tunable liquid microlens capable of adjusting the position of its focal spot in all three dimensions. The microlens consists of a droplet of a transparent conductive liquid placed on a dielectric substrate with a hydrophobic coating. By varying the voltage applied to the structure, both the position and the curvature of the microlens can be changed. The influence of the bulk and surface properties of the materials on the microlens behavior is experimentally investigated and supported by theoretical calculations. Some of the potential problems associated with the stick-slip behavior and contact angle hysteresis are outlined and possible ways to prevent them are suggested.

Liquid lens based on electrowetting: a new adaptive component for imaging applications in consumer electronics

NASA Astrophysics Data System (ADS)

Crassous, Jerome; Gabay, Claude; Liogier, Gaetan; Berge, Bruno

2004-12-01

A new technology for focus variation with direct electric control without moving part will be presented. The technology relies on an interface between two non-miscible transparent liquids, which can be deformed by electrowetting. This technology has been developed since 10 years in the lab and starts to be available commercially, with the following characteristics: large amplitude of dioptric correction (20 dioptries for a 5mm pupil size), fast response, small power consumption and good transmission in the visible range, clear pupil 1-10mm diameter. This paper will show the basic principle, as well as the physical limitations and optical aberrations due to differential thermal expansion of the two liquids in the cell. Experimental measurements made with a Schack Hartmann wave front analyzer will be presented, as well as numerical simulations of the liquid-liquid interface. Applications will be discussed, mainly in consumer electronics.

Interfacial waves generated by contact line motion through electrowetting

NASA Astrophysics Data System (ADS)

Ha, Jonghyun; Park, Jaebum; Kim, Yunhee; Bae, Jungmok; Kim, Ho-Young

2013-11-01

The contact angle of a liquid-fluid interface can be effectively modulated by EWOD (electrowetting on dielectric). Rapid movement of the contact line, which can be achieved by swift change of voltages at the electrodes, can give rise to interfacial waves under the strong influence of surface tension. Many optofluidic devices employing EWOD actuation, such as lenses, three-dimensional displays and laser radar, use two different liquids in a single cell, implying that the motions of the two liquids should be considered simultaneously to solve the dynamics of interfacial waves. Furthermore, the capillary waves excited by moving contact lines, which inherently involve slipping flows at solid boundaries, pose an interesting problem that has not been treated so far. We perform a perturbation analysis for this novel wave system to find the dispersion relation that relates the wavenumber, and the decay length over which the wave is dissipated by viscous effects. We experimentally corroborate our theory.

Simulation, fabrication, and characterization of a tunable electrowetting-based lens with a wedge-shaped PDMS dielectric layer.

PubMed

Moghaddam, Mohammadreza Salehi; Latifi, H; Shahraki, Hamidreza; Cheri, Mohammad Sadegh

2015-04-01

Microlenses with tunable focal length have wide applications in optofluidic devices. This work presents a numerical and experimental investigation on a tunable electrowetting-based concave lens. Optical properties such as focal length of the lens and visibility of images were investigated numerically and experimentally. A finite element analysis and a ZEMAX simulation were used for determination of surface profile and focal length of the lens. The results show that the theoretical surface profile and focal length of the lens are in good agreement with the experimental ones. The lens has a wide tuning focal length equal to 6.5 (cm). Because the polydimethylsiloxane (PDMS) layer is wedge shaped (as both the dielectric and hydrophobic layers), lower applied voltage is needed. A commercial program was used to find the focal length of the lens from maximum visibility value by tuning the applied voltage.

Electrowetting (EW)-based valve combined with hydrophilic teflon microfluidic guidance in controlling continuous fluid flow.

PubMed

Cheng, Ji-Yen; Hsiung, Lo-Chang

2004-12-01

Electrowetting (EW)-based techniques have been widely used in manipulating discrete liquid. However, few articles discussed the controlling of continuous fluid flow by using EW-based techniques. In this paper, an EW-based valve combined with plasma-modified Teflon surface, which serves as a microfluidic guidance, in controlling continuous fluid flow has been demonstrated. The plasma-modified Teflon surface is firstly demonstrated for confining continuous fluid flow. The EW-based microfluidic device possesses the functions of a valve and a microchannel without complex moving parts and grooved microchannels. The quantitative characteristics of the EW-based valve are also studied. Propylene carbonate (PC) is firstly demonstrated as the working liquid in the EW-based device because of its applications in parallel oligonucleotide synthesis. It is found that lower valve actuation voltage reduces the deterioration of the valve and improves the valve stability.

Design and analysis of a low actuation voltage electrowetting-on-dielectric microvalve for drug delivery applications.

PubMed

Samad, Mst Fateha; Kouzani, Abbas Z

2014-01-01

This paper presents a low actuation voltage microvalve with optimized insulating layers that manipulates a conducting ferro-fluid droplet by the principle of electrowetting-on-dielectric (EWOD). The proposed EWOD microvalve contains an array of chromium (Cr) electrodes on the soda-lime glass substrate, covered by both dielectric and hydrophobic layers. Various dielectric layers including Su-8 2002, Polyvinylidenefluoride (PVDF) and Cyanoethyl pullulan (CEP), and thin (50 nm) hydrophobic Teflon and Cytonix are used to analyze the EWOD microvalves at different voltages. The Finite Element Method (FEM) based software, Coventorware is used to carry out the simulation analysis. It is observed that the EWOD microvalve having a CEP dielectric layer with dielectric constant of about 20 and thickness of 1 μm, and a Cytonix hydrophobic layer with thickness of 50 nm operated the conducting ferro-fluid droplet at the actuation voltage as low as 7.8 V.

Droplet Velocity Measurement Based on Dielectric Layer Thickness Variation Using Digital Microfluidic Devices.

PubMed

Zulkepli, Siti Noor Idora Syafinaz; Hamid, Nor Hisham; Shukla, Vineeta

2018-05-08

In recent years, the number of interdisciplinary research works related to the development of miniaturized systems with integrated chemical and biological analyses is increasing. Digital microfluidic biochips (DMFBs) are one kind of miniaturized systems designed for conducting inexpensive, fast, convenient and reliable biochemical assay procedures focusing on basic scientific research and medical diagnostics. The role of a dielectric layer in the digital microfluidic biochips is prominent as it helps in actuating microliter droplets based on the electrowetting-on-dielectric (EWOD) technique. The advantages of using three different material layers of dielectric such as parafilm, polytetrafluoroethylene (PTFE) and ethylene tetrafluoroethylene (ETFE) were reported in the current work. A simple fabrication process of a digital microfluidic device was performed and good results were obtained. The threshold of the actuation voltage was determined for all dielectric materials of varying thicknesses. Additionally, the OpenDrop device was tested by utilizing a single-plate system to transport microliter droplets for a bioassay operation. With the newly proposed fabrication methods, these dielectric materials showed changes in contact angle and droplet velocity when the actuation voltage was applied. The threshold actuation voltage for the dielectric layers of 10⁻13 μm was 190 V for the open plate DMFBs.

Magnetohydrodynamic actuation of droplets for millimetric planar fluidic systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmadi, A., E-mail: ali.ahmadi@ubc.ca; McDermid, C. M.; Markley, L.

2016-01-04

In this work, a magnetohydrodynamic method is proposed for the actuation of droplets in small-scale planar fluidic systems, providing an alternative to commonly used methods such as electrowetting-on-dielectric. Elementary droplet-based operations, including transport, merging, and mixing, are demonstrated. The forces acting on millimetric droplets are carefully investigated, with a primary focus on the magnetic actuation force and on the unbalanced capillary forces that arise due to hysteresis. A super-hydrophobic channel is 3D printed to guide the droplets, with thin wires installed as contact electrodes and permanent magnets providing a static magnetic field. It is shown that droplet motion is enhancedmore » by increasing the droplet size and minimizing the electrode contact surface. The effects of channel geometry on threshold voltage and minimum moveable droplet volume are characterized. Finally, the presence of electrolysis is investigated and mitigating strategies are discussed.« less

Microelectromechanical-System-Based Variable-Focus Liquid Lens for Capsule Endoscopes

NASA Astrophysics Data System (ADS)

Seo, Sang Won; Han, Seungoh; Seo, Jun Ho; Kim, Young Mok; Kang, Moon Sik; Min, Nam Ki; Choi, Woo Beom; Sung, Man Young

2009-05-01

A liquid lens based on the electrowetting phenomenon was designed to be cylindrical to minimize dead area. The lens was fabricated with microelectromechanical-system (MEMS) technology using silicon thin film and wafer bonding processes. A multiple dielectric layer comprising Teflon, silicon nitride, and thermal oxide was formed on the cylinder wall. With a change of 11 Vrms in the applied bias, the lens module, including the fabricated liquid lens, showed a focal length change of approximately 166 mm. A capsule endoscope was assembled, including the lens module, and was successfully used to take images of a pig colon at various focal lengths.

Droplet microactuator system

NASA Technical Reports Server (NTRS)

Pamula, Vamsee K. (Inventor); Pollack, Michael G. (Inventor); Eckhardt, Allen E. (Inventor); Paik, Philip Y. (Inventor); Srinivasan, Vijay (Inventor)

2010-01-01

The present invention relates to a droplet microactuator system. According to one embodiment, the droplet microactuator system includes: (a) a droplet microactuator configured to conduct droplet operations; (b) a magnetic field source arranged to immobilize magnetically responsive beads in a droplet during droplet operations; (c) a sensor configured in a sensing relationship with the droplet microactuator, such that the sensor is capable of sensing a signal from and/or a property of one or more droplets on the droplet microactuator; and (d) one or more processors electronically coupled to the droplet microactuator and programmed to control electrowetting-mediated droplet operations on the droplet actuator and process electronic signals from the sensor.

Bidirectional optical switch based on electrowetting

NASA Astrophysics Data System (ADS)

Liu, Chao; Li, Lei; Wang, Qiong-Hua

2013-05-01

In this paper, we demonstrate a bidirectional optical switch based on electrowetting. Four rectangular polymethyl methacrylate substrates are stacked to form the device and three ITO electrodes are fabricated on the bottom substrate. A black liquid droplet is placed on the middle of the ITO electrode and surrounded by silicone oil. When we apply a voltage to one ITO electrode, the droplet stretches and moves in one direction and a light beam is covered by the stretched droplet, while the droplet yields a space to let the original blocked light pass through. Due to the shift of the droplet, our device functions as a bidirectional optical switch. Our experiment shows that the device can obtain a wide optical attenuation from ˜1 dB to 30 dB and the transmission loss is ˜0.67 dB. The response time of the device is ˜177 ms. The proposed optical switch has potential applications in variable optical attenuators, electronic displays, and light shutters.

Analysis and Numerical Simulation of EWOD of a Droplet for Application in a Variable Focus Microlens

NASA Astrophysics Data System (ADS)

Chang, Yuan-Jen; Mohseni, Kamran; Bright, Victor

2006-11-01

Modification of the curvature of the interface between a conductive (water) and isolating (oil) liquids is used in order to design a tunable microlens. Electrowetting on Dielectric (EWOD), the modification of surface energy of a conductive droplet on an isolated electrode, is employed in order to change the interface curvature and tune the microlens. Several features of the microlens design are addressed. These includes: the drop-centering mechanism, matching of the density of the two immiscible liquids, refractive indexes of the two liquids, and planar electrodes for electrowetting. A dimensional analysis is performed to identify the relevant nondimensional parameters. Direct numerical simulation of the hydrodynamic and electric fields is carried out. It is found that the focal length of the microlens changes continuously from negative to positive by applying a voltage from 0 to 200 volts. The focusing speed of the microlens is calculated to be around 10 milli-seconds. A successfully fabricated microlens device has been demonstrated.

An adaptive liquid microlens driven by a ferrofluidic transducer

NASA Astrophysics Data System (ADS)

Xiao, Wenjia; Hardt, Steffen

2010-05-01

Ferrofluids behave superparamagnetically and can be manipulated by external magnetic fields, providing numerous applications in microfluidic systems. In this paper, an adaptive liquid microlens driven by a ferrofluidic actuator is presented. The microlens consists of a cylindrical well filled with a lens liquid connected to a microchannel containing a ferrofluid plug. When the ferrofluid plug is moved back and forth by an external magnetic field, the lens liquid is displaced, forming a liquid lens with an adaptive focus in the cylindrical well. The focal length of the lens can be changed from infinity to the scale of the radius of the cylindrical well, leading to a high optical power compared to conventional liquid lenses utilizing liquid crystals or electrowetting. The lens curvature is reversibly tunable without hysteresis when the ferrofluid plug moves with a speed below a specific threshold value. The lens can be acted on by a magnetic field of about 100 mT which can be generated by microcoils requiring much lower voltages than the electrowetting principle.

Analysis of Drop Oscillations Excited by an Electrical Point Force in AC EWOD

NASA Astrophysics Data System (ADS)

Oh, Jung Min; Ko, Sung Hee; Kang, Kwan Hyoung

2008-03-01

Recently, a few researchers have reported the oscillation of a sessile drop in AC EWOD (electrowetting on dielectrics), and some of its consequences. The drop oscillation problem in AC EWOD is associated with various applications based on electrowetting such as LOC (lab-on-a-chip), liquid lens, and electronic display. However, no theoretical analysis of the problem has been attempted yet. In the present paper, we propose a theoretical model to analyze the oscillation by applying the conventional method to analyze the drop oscillation. The domain perturbation method is used to derive the shape mode equations under the assumptions of weak viscous flow and small deformation. The Maxwell stress is exerted on the three-phase contact line of the droplet like a point force. The force is regarded as a delta function, and is decomposed into the driving forces of each shape mode. The theoretical results on the shape and the frequency responses are compared with experiments, which shows a qualitative agreement.

Eclipse SteerTech liquid lenslet beam steering technology

NASA Astrophysics Data System (ADS)

Westfall, Raymond T.; Rogers, Stanley; Shannon, Kenneth C., III

2007-09-01

Eclipse SteerTech TM transmissive fluid state electrowetting technology has successfully demonstrated the ability to control the shape and position of a fluid lenslet. In its final form, the technology will incorporate a dual fluid lenslet approach capable of operating in extremely high acceleration environments. The beam steering system works on the principle of electro-wetting. A substrate is covered with a closely spaced array of, independently addressable, transparent, electrically conductive pixels utilizing Eclipse's proprietary EclipseTEC TM technology. By activating and deactivating selected EclipseTEC TM pixels in the proper sequence, the shape and position of fluid lenslets or arrays of lenslets can be dynamically changed at will. The position and shape of individual fluid lenslets may be accurately controlled on any flat, simply curved, or complex curved, transparent or reflective surface. The smaller the pixels the better control of the position and shape of the fluid lenslets. Information on the successful testing of the Eclipse SteerTech TM lenslet and discussion of its use in a de-centered lenslet array will be presented.

Miniaturized fiber-coupled confocal fluorescence microscope with an electrowetting variable focus lens using no moving parts

PubMed Central

Ozbay, Baris N.; Losacco, Justin T.; Cormack, Robert; Weir, Richard; Bright, Victor M.; Gopinath, Juliet T.; Restrepo, Diego; Gibson, Emily A.

2015-01-01

We report a miniature, lightweight fiber-coupled confocal fluorescence microscope that incorporates an electrowetting variable focus lens to provide axial scanning for full three-dimensional (3D) imaging. Lateral scanning is accomplished by coupling our device to a laser-scanning confocal microscope through a coherent imaging fiber-bundle. The optical components of the device are combined in a custom 3D-printed adapter with an assembled weight of <2 g that can be mounted onto the head of a mouse. Confocal sectioning provides an axial resolution of ~12 µm and an axial scan range of ~80 µm. The lateral field-of-view is 300 µm, and the lateral resolution is 1.8 µm. We determined these parameters by imaging fixed sections of mouse neuronal tissue labeled with green fluorescent protein (GFP) and fluorescent bead samples in agarose gel. To demonstrate viability for imaging intact tissue, we resolved multiple optical sections of ex vivo mouse olfactory nerve fibers expressing yellow fluorescent protein (YFP). PMID:26030555

Optical switch based on tunable aperture.

PubMed

Li, Lei; Liu, Chao; Wang, Qiong-Hua

2012-08-15

We propose an optical switch based on the electrowetting effect. A transparent oil and a dye-doped water fill a cell. The two liquids are immiscible and form a curved interface. A transparent pillar-shaped platform with a round dome is fixed on the substrate. The dome of the platform is submerged in the water. As a result, light is highly absorbed by the covered water. When the shape of the water is changed, the oil can touch the dome of the platform due to the electrowetting effect. Then the transparent platform and the oil form a channel which can pass through the incident light. Our results show that the system can obtain a high optical attenuation (∼928:1) and reasonable response time (∼47  ms). The diameter of the aperture can be tuned from 0 to ∼3.0  mm. The proposed optical switch has potential application in light shutters, variable optical attenuators, and adaptive irises.

Development of a digital microfluidic platform for point of care testing

PubMed Central

Sista, Ramakrishna; Hua, Zhishan; Thwar, Prasanna; Sudarsan, Arjun; Srinivasan, Vijay; Eckhardt, Allen; Pollack, Michael; Pamula, Vamsee

2009-01-01

Point of care testing is playing an increasingly important role in improving the clinical outcome in health care management. The salient features of a point of care device are quick results, integrated sample preparation and processing, small sample volumes, portability, multifunctionality and low cost. In this paper, we demonstrate some of these salient features utilizing an electrowetting-based Digital Microfluidic platform. We demonstrate the performance of magnetic bead-based immunoassays (cardiac troponin I) on a digital microfluidic cartridge in less than 8 minutes using whole blood samples. Using the same microfluidic cartridge, a 40-cycle real-time polymerase chain reaction was performed within 12 minutes by shuttling a droplet between two thermal zones. We further demonstrate, on the same cartridge, the capability to perform sample preparation for bacterial and fungal infectious disease pathogens (methicillin-resistance Staphylococcus aureus and Candida albicans) and for human genomic DNA using magnetic beads. In addition to rapid results and integrated sample preparation, electrowetting-based digital microfluidic instruments are highly portable because fluid pumping is performed electronically. All the digital microfluidic chips presented here were fabricated on printed circuit boards utilizing mass production techniques that keep the cost of the chip low. Due to the modularity and scalability afforded by digital microfluidics, multifunctional testing capability, such as combinations within and between immunoassays, DNA amplification, and enzymatic assays, can be brought to the point of care at a relatively low cost because a single chip can be configured in software for different assays required along the path of care. PMID:19023472

Electromechanical model to predict the movability of liquids in an electrowetting-on-dielectric microfluidic device

NASA Astrophysics Data System (ADS)

Torabinia, Matin; Farzbod, Ali; Moon, Hyejin

2018-04-01

In electrowetting-on-dielectric (EWOD) microfluidics, a motion of a fluid is created by a voltage applied to the fluid/surface interface. Water and aqueous solutions are the most frequently used fluids in EWOD devices. In order for EWOD microfluidics to be a versatile platform for various applications, however, movability of different types of fluids other than aqueous solutions should be understood. An electromechanical model using a simple RC circuit has been used to predict the mechanical force exerted on a liquid droplet upon voltage application. In this present study, two important features missed in previous works are addressed. Energy dissipation by contact line friction is considered in the new model as the form of resistor. The phase angle is taken into account in the analysis of the AC circuit. The new electromechanical model and computation results are validated with experimental measurements of forces on two different liquids. The model is then used to explain influences of contact angle hysteresis, surface tension, conductivity, and dielectric constant of fluids to the mechanical force on a liquid droplet.

Electric field enhanced dropwise condensation on hydrophobic surfaces

NASA Astrophysics Data System (ADS)

Baratian, Davood; Hoek, Harmen; van den Ende, Dirk; Mugele, Frieder; Physics of Complex Fluids Team

2016-11-01

Dropwise condensation occurs when vapor condenses on a low surface energy surface, and the substrate is just partially wetted by the condensate. Dropwise condensation has attracted significant attention due to its reported superior heat transfer performance compared to filmwise condensation. Extensive research efforts are focused on how to promote, and enhance dropwise condensation by considering both physical and chemical factors. We have studied electrowetting-actuated condensation on hydrophobic surfaces, aiming for enhancement of heat transfer in dropwise condensation. The idea is to use suitably structured patterns of micro-electrodes that generate a heterogeneous electric field at the interface and thereby promote both the condensation itself and the shedding of condensed drops. Comforting the shedding of droplets on electrowetting-functionalized surfaces allows more condensing surface area for re-nucleation of small droplets, leading to higher condensation rates. Possible applications of this innovative concept include heat pipes for (micro) coolers in electronics as well as in more efficient heat exchangers. We acknowledge financial support by the Dutch Technology Foundation STW, which is part of the Netherlands Organization for Scientific Research (NWO), within the VICI program.

Transmittance tuning by particle chain polarization in electrowetting-driven droplets

PubMed Central

Fan, Shih-Kang; Chiu, Cheng-Pu; Huang, Po-Wen

2010-01-01

A tiny droplet containing nano∕microparticles commonly handled in digital microfluidic lab-on-a-chip is regarded as a micro-optical component with tunable transmittance at programmable positions for the application of micro-opto-fluidic-systems. Cross-scale electric manipulations of droplets on a millimeter scale as well as suspended particles on a micrometer scale are demonstrated by electrowetting-on-dielectric (EWOD) and particle chain polarization, respectively. By applying electric fields at proper frequency ranges, EWOD and polarization can be selectively achieved in designed and fabricated parallel plate devices. At low frequencies, the applied signal generates EWOD to pump suspension droplets. The evenly dispersed particles reflect and∕or absorb the incident light to exhibit a reflective or dark droplet. When sufficiently high frequencies are used on to the nonsegmented parallel electrodes, a uniform electric field is established across the liquid to polarize the dispersed neutral particles. The induced dipole moments attract the particles each other to form particle chains and increase the transmittance of the suspension, demonstrating a transmissive or bright droplet. In addition, the reflectance of the droplet is measured at various frequencies with different amplitudes. PMID:21267088

Two-photon laser scanning microscopy with electrowetting-based prism scanning

PubMed Central

Supekar, Omkar D.; Ozbay, Baris N.; Zohrabi, Mo; Nystrom, Philip D.; Futia, Gregory L.; Restrepo, Diego; Gibson, Emily A.; Gopinath, Juliet T.; Bright, Victor M.

2017-01-01

Laser scanners are an integral part of high resolution biomedical imaging systems such as confocal or 2-photon excitation (2PE) microscopes. In this work, we demonstrate the utility of electrowetting on dielectric (EWOD) prisms as a lateral laser-scanning element integrated in a conventional 2PE microscope. To the best of our knowledge, this is the first such demonstration for EWOD prisms. EWOD devices provide a transmissive, low power consuming, and compact alternative to conventional adaptive optics, and hence this technology has tremendous potential. We demonstrate 2PE microscope imaging of cultured mouse hippocampal neurons with a FOV of 130 × 130 μm2 using EWOD prism scanning. In addition, we show simulations of the optical system with the EWOD prism, to evaluate the effect of propagating a Gaussian beam through the EWOD prism on the imaging quality. Based on the simulation results a beam size of 0.91 mm full width half max was chosen to conduct the imaging experiments, resulting in a numerical aperture of 0.17 of the imaging system. PMID:29296477

Method for using magnetic particles in droplet microfluidics

NASA Technical Reports Server (NTRS)

Shah, Gaurav Jitendra (Inventor); Kim, Chang-Jin (Inventor)

2012-01-01

Methods of utilizing magnetic particles or beads (MBs) in droplet-based (or digital) microfluidics are disclosed. The methods may be used in enrichment or separation processes. A first method employs the droplet meniscus to assist in the magnetic collection and positioning of MBs during droplet microfluidic operations. The sweeping movement of the meniscus lifts the MBs off the solid surface and frees them from various surface forces acting on the MBs. A second method uses chemical additives to reduce the adhesion of MBs to surfaces. Both methods allow the MBs on a solid surface to be effectively moved by magnetic force. Droplets may be driven by various methods or techniques including, for example, electrowetting, electrostatic, electromechanical, electrophoretic, dielectrophoretic, electroosmotic, thermocapillary, surface acoustic, and pressure.

Digital microfluidics: A promising technique for biochemical applications

NASA Astrophysics Data System (ADS)

Wang, He; Chen, Liguo; Sun, Lining

2017-12-01

Digital microfluidics (DMF) is a versatile microfluidics technology that has significant application potential in the areas of automation and miniaturization. In DMF, discrete droplets containing samples and reagents are controlled to implement a series of operations via electrowetting-on-dielectric. This process works by applying electrical potentials to an array of electrodes coated with a hydrophobic dielectric layer. Unlike microchannels, DMF facilitates precise control over multiple reaction processes without using complex pump, microvalve, and tubing networks. DMF also presents other distinct features, such as portability, less sample consumption, shorter chemical reaction time, flexibility, and easier combination with other technology types. Due to its unique advantages, DMF has been applied to a broad range of fields (e.g., chemistry, biology, medicine, and environment). This study reviews the basic principles of droplet actuation, configuration design, and fabrication of the DMF device, as well as discusses the latest progress in DMF from the biochemistry perspective.

Coplanar electrowetting-induced stirring as a tool to manipulate biological samples in lubricated digital microfluidics. Impact of ambient phase on drop internal flow patterna)

PubMed Central

Davoust, Laurent; Fouillet, Yves; Malk, Rachid; Theisen, Johannes

2013-01-01

Oscillating electrowetting on dielectrics (EWOD) with coplanar electrodes is investigated in this paper as a way to provide efficient stirring within a drop with biological content. A supporting model inspired from Ko et al. [Appl. Phys. Lett. 94, 194102 (2009)] is proposed allowing to interpret oscillating EWOD-induced drop internal flow as the result of a current streaming along the drop surface deformed by capillary waves. Current streaming behaves essentially as a surface flow generator and the momentum it sustains within the (viscous) drop is even more significant as the surface to volume ratio is small. With the circular electrode pair considered in this paper, oscillating EWOD sustains toroidal vortical flows when the experiments are conducted with aqueous drops in air as ambient phase. But when oil is used as ambient phase, it is demonstrated that the presence of an electrode gap is responsible for a change in drop shape: a pinch-off at the electrode gap yields a peanut-shaped drop and a symmetry break-up of the EWOD-induced flow pattern. Viscosity of oil is also responsible for promoting an efficient damping of the capillary waves which populate the surface of the actuated drop. As a result, the capillary network switches from one standing wave to two superimposed traveling waves of different mechanical energy, provided that actuation frequency is large enough, for instance, as large as the one commonly used in electrowetting applications (f ∼ 500 Hz and beyond). Special emphasis is put on stirring of biological samples. As a typical application, it is demonstrated how beads or cell clusters can be focused under flow either at mid-height of the drop or near the wetting plane, depending on how the nature of the capillary waves is (standing or traveling), and therefore, depending on the actuation frequency (150 Hz–1 KHz). PMID:24404038

Light-driven 3D droplet manipulation on flexible optoelectrowetting devices fabricated by a simple spin-coating method.

PubMed

Jiang, Dongyue; Park, Sung-Yong

2016-05-21

Technical advances in electrowetting-on-dielectric (EWOD) over the past few years have extended our attraction to three-dimensional (3D) devices capable of providing more flexibility and functionality with larger volumetric capacity than conventional 2D planar ones. However, typical 3D EWOD devices require complex and expensive fabrication processes for patterning and wiring of pixelated electrodes that also restrict the minimum droplet size to be manipulated. Here, we present a flexible single-sided continuous optoelectrowetting (SCOEW) device which is not only fabricated by a spin-coating method without the need for patterning and wiring processes, but also enables light-driven 3D droplet manipulations. To provide photoconductive properties, previous optoelectrowetting (OEW) devices have used amorphous silicon (a-Si) typically fabricated through high-temperature processes over 300 °C such as CVD or PECVD. However, most of the commercially-available flexible substrates such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) experience serious thermal deformation under such high-temperature processes. Because of this compatibility issue of conventional OEW devices with flexible substrates, light-driven 3D droplet manipulations have not yet been demonstrated on flexible substrates. Our study overcomes this compatibility issue by using a polymer-based photoconductive material, titanium oxide phthalocyanine (TiOPc) and thus SCOEW devices can be simply fabricated on flexible substrates through a low-cost, spin-coating method. In this paper, analytical studies were conducted to understand the effects of light patterns on static contact angles and EWOD forces. For experimental validations of our study, flexible SCOEW devices were successfully fabricated through the TiOPc-based spin-coating method and light-driven droplet manipulations (e.g. transportation, merging, and splitting) have been demonstrated on various 3D terrains such as inclined, vertical, upside-down, and curved surfaces. Our flexible SCOEW technology offers the benefits of device simplicity, flexibility, and functionality over conventional EWOD and OEW devices by enabling optical droplet manipulations on a 3D featureless surface.

Say goodbye to coffee stains

NASA Astrophysics Data System (ADS)

Burak Eral, H.; van den Ende, Dirk; Mugele, Frieder

2012-04-01

Discussing ideas over a mug of coffee or tea is the lifeblood of science, but have you ever thought about the stains that can be inadvertently left behind? H Burak Eral, Dirk van den Ende and Frieder Mugele explain how these stains, which can be a major annoyance in some biology techniques, can be altered for the better using a technique called electrowetting.

Liquid metal actuation by electrical control of interfacial tension

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eaker, Collin B.; Dickey, Michael D., E-mail: michael-dickey@ncsu.edu

2016-09-15

By combining metallic electrical conductivity with low viscosity, liquid metals and liquid metal alloys offer new and exciting opportunities to serve as reconfigurable components of electronic, microfluidic, and electromagnetic devices. Here, we review the physics and applications of techniques that utilize voltage to manipulate the interfacial tension of liquid metals; such techniques include electrocapillarity, continuous electrowetting, electrowetting-on-dielectric, and electrochemistry. These techniques lower the interfacial tension between liquid metals and a surrounding electrolyte by driving charged species (or in the case of electrochemistry, chemical species) to the interface. The techniques are useful for manipulating and actuating liquid metals at sub-mm lengthmore » scales where interfacial forces dominate. We focus on metals and alloys that are liquid near or below room temperature (mercury, gallium, and gallium-based alloys). The review includes discussion of mercury—despite its toxicity—because it has been utilized in numerous applications and it offers a way of introducing several phenomena without the complications associated with the oxide layer that forms on gallium and its alloys. The review focuses on the advantages, applications, opportunities, challenges, and limitations of utilizing voltage to control interfacial tension as a method to manipulate liquid metals.« less

Electrically Driven Liquid Film Boiling Experiment

NASA Technical Reports Server (NTRS)

Didion, Jeffrey R.

2016-01-01

This presentation presents the science background and ground based results that form the basis of the Electrically Driven Liquid Film Boiling Experiment. This is an ISS experiment that is manifested for 2021. Objective: Characterize the effects of gravity on the interaction of electric and flow fields in the presence of phase change specifically pertaining to: a) The effects of microgravity on the electrically generated two-phase flow. b) The effects of microgravity on electrically driven liquid film boiling (includes extreme heat fluxes). Electro-wetting of the boiling section will repel the bubbles away from the heated surface in microgravity environment. Relevance/Impact: Provides phenomenological foundation for the development of electric field based two-phase thermal management systems leveraging EHD, permitting optimization of heat transfer surface area to volume ratios as well as achievement of high heat transfer coefficients thus resulting in system mass and volume savings. EHD replaces buoyancy or flow driven bubble removal from heated surface. Development Approach: Conduct preliminary experiments in low gravity and ground-based facilities to refine technique and obtain preliminary data for model development. ISS environment required to characterize electro-wetting effect on nucleate boiling and CHF in the absence of gravity. Will operate in the FIR - designed for autonomous operation.

Repulsion-based model for contact angle saturation in electrowetting

PubMed Central

2015-01-01

We introduce a new model for contact angle saturation phenomenon in electrowetting on dielectric systems. This new model attributes contact angle saturation to repulsion between trapped charges on the cap and base surfaces of the droplet in the vicinity of the three-phase contact line, which prevents these surfaces from converging during contact angle reduction. This repulsion-based saturation is similar to repulsion between charges accumulated on the surfaces of conducting droplets which causes the well known Coulombic fission and Taylor cone formation phenomena. In our model, both the droplet and dielectric coating were treated as lossy dielectric media (i.e., having finite electrical conductivities and permittivities) contrary to the more common assumption of a perfectly conducting droplet and perfectly insulating dielectric. We used theoretical analysis and numerical simulations to find actual charge distribution on droplet surface, calculate repulsion energy, and minimize energy of the total system as a function of droplet contact angle. Resulting saturation curves were in good agreement with previously reported experimental results. We used this proposed model to predict effect of changing liquid properties, such as electrical conductivity, and system parameters, such as thickness of the dielectric layer, on the saturation angle, which also matched experimental results. PMID:25759748

Repulsion-based model for contact angle saturation in electrowetting.

PubMed

Ali, Hassan Abdelmoumen Abdellah; Mohamed, Hany Ahmed; Abdelgawad, Mohamed

2015-01-01

We introduce a new model for contact angle saturation phenomenon in electrowetting on dielectric systems. This new model attributes contact angle saturation to repulsion between trapped charges on the cap and base surfaces of the droplet in the vicinity of the three-phase contact line, which prevents these surfaces from converging during contact angle reduction. This repulsion-based saturation is similar to repulsion between charges accumulated on the surfaces of conducting droplets which causes the well known Coulombic fission and Taylor cone formation phenomena. In our model, both the droplet and dielectric coating were treated as lossy dielectric media (i.e., having finite electrical conductivities and permittivities) contrary to the more common assumption of a perfectly conducting droplet and perfectly insulating dielectric. We used theoretical analysis and numerical simulations to find actual charge distribution on droplet surface, calculate repulsion energy, and minimize energy of the total system as a function of droplet contact angle. Resulting saturation curves were in good agreement with previously reported experimental results. We used this proposed model to predict effect of changing liquid properties, such as electrical conductivity, and system parameters, such as thickness of the dielectric layer, on the saturation angle, which also matched experimental results.

Miniature, minimally invasive, tunable endoscope for investigation of the middle ear.

PubMed

Pawlowski, Michal E; Shrestha, Sebina; Park, Jesung; Applegate, Brian E; Oghalai, John S; Tkaczyk, Tomasz S

2015-06-01

We demonstrate a miniature, tunable, minimally invasive endoscope for diagnosis of the auditory system. The probe is designed to sharply image anatomical details of the middle ear without the need for physically adjusting the position of the distal end of the endoscope. This is achieved through the addition of an electrowetted, tunable, electronically-controlled lens to the optical train. Morphological imaging is enabled by scanning light emanating from an optical coherence tomography system. System performance was demonstrated by imaging part of the ossicular chain and wall of the middle ear cavity of a normal mouse. During the experiment, we electronically moved the plane of best focus from the incudo-stapedial joint to the stapedial artery. Repositioning the object plane allowed us to image anatomical details of the middle ear beyond the depth of field of a static optical system. We also demonstrated for the first time to our best knowledge, that an optical system with an electrowetted, tunable lens may be successfully employed to measure sound-induced vibrations within the auditory system by measuring the vibratory amplitude of the tympanic membrane in a normal mouse in response to pure tone stimuli.

Nanopipettes as Monitoring Probes for the Single Living Cell: State of the Art and Future Directions in Molecular Biology.

PubMed

Bulbul, Gonca; Chaves, Gepoliano; Olivier, Joseph; Ozel, Rifat Emrah; Pourmand, Nader

2018-06-06

Examining the behavior of a single cell within its natural environment is valuable for understanding both the biological processes that control the function of cells and how injury or disease lead to pathological change of their function. Single-cell analysis can reveal information regarding the causes of genetic changes, and it can contribute to studies on the molecular basis of cell transformation and proliferation. By contrast, whole tissue biopsies can only yield information on a statistical average of several processes occurring in a population of different cells. Electrowetting within a nanopipette provides a nanobiopsy platform for the extraction of cellular material from single living cells. Additionally, functionalized nanopipette sensing probes can differentiate analytes based on their size, shape or charge density, making the technology uniquely suited to sensing changes in single-cell dynamics. In this review, we highlight the potential of nanopipette technology as a non-destructive analytical tool to monitor single living cells, with particular attention to integration into applications in molecular biology.

Polydimethylsiloxane as dielectric and hydrophobic material in electro-wetting liquid lens

NASA Astrophysics Data System (ADS)

Wang, Liang; Duan, Junping; Zhang, Binzhen; Wang, Wanjun

2016-10-01

An electro-wetting-based variable-focus liquid lens with a spin coated polydimethylsiloxane (PDMS) layer is presented. The PDMS layer acts as both insulation and hydrophobic material of the liquid lens. By changing the applied voltage between the two electrodes, the radius of the water-oil contact curved surface is adjusted to realize the zoom function. In preparation process, at first, the liquid lens is divided into two parts, the PDMS substrate and the cavity, and then two parts of liquid lens are bonding together after surface treatment. After liquid injection and sealing cavity, the whole process was accomplished. The zooming performance of lens is tested, and COMSOL is used to analyze the shape of the water-oil contact curved surface at different voltages, the results shows that with the applied voltage changing from 0V to 120V, the height of meniscus vertex reduced from 2.41mm to 1.67mm, and the focal length changes from -14.3mm to infinity first, and then to 27.1mm.

Study of surface modes on a vibrating electrowetting liquid lens

NASA Astrophysics Data System (ADS)

Strauch, Matthias; Shao, Yifeng; Bociort, Florian; Urbach, H. Paul

2017-10-01

The increased usage of liquid lenses motivates us to investigate surface waves on the liquid's surface. During fast focal switching, the surface waves decrease the imaging quality. We propose a model that describes the surface modes appearing on a liquid lens and predicts the resonance frequencies. The effects of those surface modes on a laser beam are simulated using Fresnel propagation, and the model is verified experimentally.

Electrowetting of liquid polymer on petal-mimetic microbowl-array surfaces for formation of microlens array with varying focus on a single substrate

NASA Astrophysics Data System (ADS)

Li, Xiangmeng; Shao, Jinyou; Li, Xiangming; Tian, Hongmiao

2015-03-01

In this paper, microlens array with varying focal lengths were fabricated on a single microbowl-array textured substrate. The solid microbowl-arrayed NOA61 (kind of polyurethane-based polymer with UV curablity) surface was resulted from nanoimprinting by polydimethylsiloxane (PDMS) mold. The PDMS mold was replicated from an SU-8 master which was generated by electron beam lithography. Such microbowl-arrayed surfaces demonstrate petal-mimetic highly adhesive hydrophobic wetting properties, which can promote an irreversible electrowetting (EW) effect and a dereased contact angle of water droplets as well as other liquid droplets by applying direct current (DC) voltage. To fabricate a microlens array with varying focal-lengths, liquid NOA61 was supplied from a syringe on the solid NOA61 microtextured film and DC voltage was applied succesively. After removing the DC voltage, these liquid NOA61 microdrops deposited on the solid microtextured NOA61 surface on tin-indium-oxide coated substrate could be solidified via UV irradiation, thus leading to microlens array with uneven numerical apertures on a single substrate. Numerical simulation was also done to verify the EW effect. Finally, optical imaging characterization was performed to confirm the varied focus of the NOA61 microdrops.

Digital holographic characterization of liquid microlenses array fabricated in electrode-less configuration

NASA Astrophysics Data System (ADS)

Miccio, L.; Vespini, V.; Grilli, S.; Paturzo, M.; Finizio, A.; De Nicola, S.; Ferraro, P.

2009-06-01

We show how thin liquid film on polar dielectric substrate can form an array of liquid micro-lenses. The effect is driven by the pyroelectric effect leading to a new concept in electro-wetting (EW). EW is a viable method for actuation of liquids in microfluidic systems and requires the design and fabrication of complex electrodes for suitable actuation of liquids. When compared to conventional electrowetting devices, the pyroelectric effect allowed to have an electrode-less and circuitless configuration. In our case the surface electric charge induced by the thermal stimulus is able to pattern selectively the surface wettability according to geometry of the ferroelectric domains micro-engineered into the lithium niobate crystal. We show that different geometries of liquid microlenses can be obtained showing also a tuneability of the focal lenses down to 1.6 mm. Thousand of liquid microlenses, each with 100 μm diameter, can be formed and actuated. Also different geometries such as hemi-cylindrical and toroidal liquid structures can be easily obtained. By means of a digital holography method, an accurate characterization of the micro-lenses curvature is performed and presented. The preliminary results concerning the imaging capability of the micro-lens array are also reported. Microlens array can find application in medical stereo-endoscopy, imaging, telecommunication and optical data storage too.

Three dimensional two-photon brain imaging in freely moving mice using a miniature fiber coupled microscope with active axial-scanning.

PubMed

Ozbay, Baris N; Futia, Gregory L; Ma, Ming; Bright, Victor M; Gopinath, Juliet T; Hughes, Ethan G; Restrepo, Diego; Gibson, Emily A

2018-05-25

We present a miniature head mounted two-photon fiber-coupled microscope (2P-FCM) for neuronal imaging with active axial focusing enabled using a miniature electrowetting lens. We show three-dimensional two-photon imaging of neuronal structure and record neuronal activity from GCaMP6s fluorescence from multiple focal planes in a freely-moving mouse. Two-color simultaneous imaging of GFP and tdTomato fluorescence is also demonstrated. Additionally, dynamic control of the axial scanning of the electrowetting lens allows tilting of the focal plane enabling neurons in multiple depths to be imaged in a single plane. Two-photon imaging allows increased penetration depth in tissue yielding a working distance of 450 μm with an additional 180 μm of active axial focusing. The objective NA is 0.45 with a lateral resolution of 1.8 μm, an axial resolution of 10 μm, and a field-of-view of 240 μm diameter. The 2P-FCM has a weight of only ~2.5 g and is capable of repeatable and stable head-attachment. The 2P-FCM with dynamic axial scanning provides a new capability to record from functionally distinct neuronal layers, opening new opportunities in neuroscience research.

Liquid metal enabled pump

PubMed Central

Tang, Shi-Yang; Khoshmanesh, Khashayar; Sivan, Vijay; Petersen, Phred; O’Mullane, Anthony P.; Abbott, Derek; Mitchell, Arnan; Kalantar-zadeh, Kourosh

2014-01-01

Small-scale pumps will be the heartbeat of many future micro/nanoscale platforms. However, the integration of small-scale pumps is presently hampered by limited flow rate with respect to the input power, and their rather complicated fabrication processes. These issues arise as many conventional pumping effects require intricate moving elements. Here, we demonstrate a system that we call the liquid metal enabled pump, for driving a range of liquids without mechanical moving parts, upon the application of modest electric field. This pump incorporates a droplet of liquid metal, which induces liquid flow at high flow rates, yet with exceptionally low power consumption by electrowetting/deelectrowetting at the metal surface. We present theory explaining this pumping mechanism and show that the operation is fundamentally different from other existing pumps. The presented liquid metal enabled pump is both efficient and simple, and thus has the potential to fundamentally advance the field of microfluidics. PMID:24550485

The Effect of Electrokinetic Controlled Wettability on Externally Measured Pressures for a Micro-Fluidic Channel

NASA Astrophysics Data System (ADS)

Zhou, X.; Nolte, D. D.; Pyrak-Nolte, L. J.

2017-12-01

The hysteretic relationship between capillary pressure (Pc) on saturation (S) has been shown to be a projection of a higher-dimensional surface that depends on interfacial area per volume (IAV) as the additional state variable. Most studies that validate the capillary-pressure-saturation-IAV relationship are performed on 2D micro-models or cores where scanning is performed in pressure and not in saturation. We have developed an EWOD technique (electro-wetting on dielectric) to internally manipulate fluid saturation to determine the effect on externally measured pressures. Applying electric fields to electrolytic fluids changes the contact angle among the fluids and the solid. For a parallel-plate electro-wetting set-up, the pressure difference is given by gsl (cosq'EW - cosqEW )/d', where d' is the aperture, qEQ and q'EW are the contact angles before and after the application of voltage, V, and gsl is the interfacial tension between the solid and liquid phases. This pressure difference enables direct control over internal fluid distributions. The contact angle reverts to the original value when V = 0. A sealed micro-model with Electro-Wetting on Dielectric (EWOD) electrodes was fabricated using a PDMS wedge-shaped channel with an entrance width of 1 mm and an exit width of 2 mm. The channel length was 2 mm, and had a depth of 0.9 mm. The PDMS channel was attached to an aluminum plate that served as the ground electrode. An ITO slide coated with PDMS formed the high voltage electrode and was used to seal the micro-model. X-ray Micro-CT scans showed that the contact angle between electrodes changes from from 110˚ (non-wetting) to 70˚ (wetting) for an applied voltage of 318 V AC. By applying voltage to the wedge-shaped micromodel, with the inlet and the outlet opened to the atmosphere, the externally measured capillary pressure remained constant even though the fluid-air interface moved and the saturation increased. For a closed system, the externally measured change in capillary pressure was 30 Pa and the saturation in the channel increased. EWOD provides method to assess the contributions of wettability to the fundamental physics of immiscible fluids in analog porous media. Acknowledgment: This research was supported by the National Science Foundation (1314663-EAR).

Wettability control of droplet deposition and detachment.

PubMed

Baret, Jean-Christophe; Brinkmann, Martin

2006-04-14

The conditions for droplet deposition on plane substrates are studied using electrowetting to continuously modulate the surface wettability. Droplets of controlled volume attached to the tip of a pipette are brought into contact with the surface. During retraction of the pipette the droplets are deposited or detach completely depending on volume and contact angle. The experimental limit of deposition in the contact angle or volume plane is in good agreement with analytical and numerical predictions obtained within the capillary model.

Digital Microfluidic Dynamic Culture of Mammalian Embryos on an Electrowetting on Dielectric (EWOD) Chip

PubMed Central

Huang, Hong-Yuan; Shen, Hsien-Hua; Tien, Chang-Hung; Li, Chin-Jung; Fan, Shih-Kang; Liu, Cheng-Hsien; Hsu, Wen-Syang; Yao, Da-Jeng

2015-01-01

Current human fertilization in vitro (IVF) bypasses the female oviduct and manually inseminates, fertilizes and cultivates embryos in a static microdrop containing appropriate chemical compounds. A microfluidic microchannel system for IVF is considered to provide an improved in-vivo-mimicking environment to enhance the development in a culture system for an embryo before implantation. We demonstrate a novel digitalized microfluidic device powered with electrowetting on a dielectric (EWOD) to culture an embryo in vitro in a single droplet in a microfluidic environment to mimic the environment in vivo for development of the embryo and to culture the embryos with good development and live births. Our results show that the dynamic culture powered with EWOD can manipulate a single droplet containing one mouse embryo and culture to the blastocyst stage. The rate of embryo cleavage to a hatching blastocyst with a dynamic culture is significantly greater than that with a traditional static culture (p<0.05). The EWOD chip enhances the culture of mouse embryos in a dynamic environment. To test the reproductive outcome of the embryos collected from an EWOD chip as a culture system, we transferred embryos to pseudo-pregnant female mice and produced live births. These results demonstrate that an EWOD-based microfluidic device is capable of culturing mammalian embryos in a microfluidic biological manner, presaging future clinical application. PMID:25933003

Digital Microfluidic Dynamic Culture of Mammalian Embryos on an Electrowetting on Dielectric (EWOD) Chip.

PubMed

Huang, Hong-Yuan; Shen, Hsien-Hua; Tien, Chang-Hung; Li, Chin-Jung; Fan, Shih-Kang; Liu, Cheng-Hsien; Hsu, Wen-Syang; Yao, Da-Jeng

2015-01-01

Current human fertilization in vitro (IVF) bypasses the female oviduct and manually inseminates, fertilizes and cultivates embryos in a static microdrop containing appropriate chemical compounds. A microfluidic microchannel system for IVF is considered to provide an improved in-vivo-mimicking environment to enhance the development in a culture system for an embryo before implantation. We demonstrate a novel digitalized microfluidic device powered with electrowetting on a dielectric (EWOD) to culture an embryo in vitro in a single droplet in a microfluidic environment to mimic the environment in vivo for development of the embryo and to culture the embryos with good development and live births. Our results show that the dynamic culture powered with EWOD can manipulate a single droplet containing one mouse embryo and culture to the blastocyst stage. The rate of embryo cleavage to a hatching blastocyst with a dynamic culture is significantly greater than that with a traditional static culture (p<0.05). The EWOD chip enhances the culture of mouse embryos in a dynamic environment. To test the reproductive outcome of the embryos collected from an EWOD chip as a culture system, we transferred embryos to pseudo-pregnant female mice and produced live births. These results demonstrate that an EWOD-based microfluidic device is capable of culturing mammalian embryos in a microfluidic biological manner, presaging future clinical application.

Cheerios Effect Controlled by Electrowetting.

PubMed

Yuan, Junqi; Feng, Jian; Cho, Sung Kwon

2015-08-04

The Cheerios effect is a common phenomenon in which small floating objects are either attracted or repelled by the sidewall due to capillary interaction. This attractive or repulsive behavior is highly dependent on the slope angles (angles of the interface on the wall or floating object with respect to a horizontal line) that can be mainly controlled by the wettability of the wall and floating object and the density of the object. In this paper, electrowetting on dielectric (EWOD) is implemented to the wall or floating object in order to actively control the wettability and thus capillary interaction. As such, the capillary force on buoyant and dense floating objects can be easily switched between repulsion and attraction by simply applying an electrical input. In addition, the theoretical prediction for the capillary force is verified experimentally by measuring the motion of floating particle and the critical contact angle on the wall at which the capillary force changes from attraction to repulsion. This successive verification is enabled by the merit of EWOD that allows for continuous change in the contact angle. Finally, the control method is extended to continuously move a floating object along a linear path and to continuously rotate a dumbbell-like floating object in centimeter scales using arrays of EWOD electrodes. A continuous linear motion is also accomplished in a smaller scale where the channel width (3 mm) is comparable to the capillary length.

On a Road to "Soft" Optical MEMS

NASA Astrophysics Data System (ADS)

Yang, Shu; Mach, Peter; Krupenkin, Tom

2003-03-01

A phenomenon of electrowetting has been applied to the actuation of micro-optical devices. The devices use small droplets of transparent conductive liquids to manipulate light in a useful way. The form and position of these droplets is controlled by the applied voltage. Both fiber based and open space optical devices are demonstrated. As an example of an open space optical device, a tunable liquid microlens capable of adjusting its focal length and lateral position is discussed. The microlens consists of a droplet of a transparent conductive liquid placed on a dielectric substrate with underlying electrodes. By varying the voltage applied to the structure, both the position and curvature of microlens can be reversibly changed. Similarly, electrowetting actuation of fluids in micro channels is employed to provide dynamic and reversible tuning of the optical fiber structures. When combined with in-fiber gratings or etched fibers this approach yields tunable broadband and narrowband filters with a large dynamic range. Both the surface and bulk properties of the materials are found important to control the device performance. Fundamental problems, such as stick-slip behavior and contact angle hysteresis associated with the surface roughness and surface contamination, are studied to optimize the choice of dielectric materials and their coatings. Some of the possible ways to control these phenomena are outlined. Several potential applications of the proposed approach are also discussed.

Surface plasmon resonance sensor using vari-focal liquid lens under angular interrogation

NASA Astrophysics Data System (ADS)

Lee, Muyoung; Bang, Yousung; Lee, Jooho; Jang, Wonjae; Won, Yong Hyub

2017-02-01

In this paper, a surface plasmon resonance sensor for the detection of refractive index variation is presented. A novel waveguide type surface plasmon resonance sensing configuration with focal length variable liquid lens is introduced. The method of surface plasmon resonance sensor is based on the waveguide type with incident angle variation. The incident angle is varied by using an electrowetting liquid lens which is possible to actively change focal length as applying voltage. The optical system, which is adapted to electrowetting lens can continuously change the incident angle of light from 73 to 78 degrees with compact size. The surface plasmon waves are excited between metal and dielectric interface. The sensing surfaces are prepared by a coating of gold metal above high refractive index glass substrate. The incident light which is 532nm monochromatic light source passes through a noble metal coated substrate to detect intensity with incident angle variation. An analysis to distinguish the contribution of light with various incident angle is focused on the angular characteristics of the surface plasmon sensor under wavelength interrogation. The resonance angle is determined corresponding to sensing material refractive index with high sensitivity. The result suggests that the performance of surface plasmon resonance sensor can be improved by real time varying incident angle. From this presented study, it provides a different approach for angular interrogation surface plasmon resonance sensor and can be miniaturized for a portable device.

Low voltage picoliter droplet manipulation utilizing electrowetting-on-dielectric platforms.

PubMed

Lin, Yan-You; Welch, Erin R F; Fair, Richard B

2012-10-01

Picoliter droplets actuated on an electrowetting-on-dielectric (EWD) actuator are demonstrated. In this study, the physical scaling of electrodes for 33 μm and 21 μm EWD devices resulted in droplets of 12 pl and 5 pl being dispensed respectively in conjunction with 3 μm SU8 gaskets. The stacked multi-layer insulators in the actuators consisted of 200 nm tantalum pentoxide (Ta 2 O 5 ) and 200 nm parylene C films deposited and coated with 70 nm of CYTOP. The voltages for dispensing droplets on chips without any external pressure sources are 17.1 V rms and 22 V rms for these two sets of devices. A 12 pl droplet can be split into two 6 pl daughter droplets at 18.7 V rms with 33 μm electrode devices. Droplet manipulation is also demonstrated with paramagnetic beads and buffer solutions with proteins. In addition, electrodes with interlocking protrusions and special featured reservoir gasket are designed to facilitate droplet dispensing on these scaled EWD devices. In order to improve sealing of the two-piece sandwich EWD structure, a soft material, Norland Optical Adhesive (NOA), was coated on the top plate along with pressure on top. We demonstrate that based on fundamental theories and experiments, the dimensional scaling of EWD devices has not yet met a limitation as long as the EWD device can be sealed well.

Low voltage picoliter droplet manipulation utilizing electrowetting-on-dielectric platforms

PubMed Central

Lin, Yan-You; Welch, Erin R.F.; Fair, Richard B.

2012-01-01

Picoliter droplets actuated on an electrowetting-on-dielectric (EWD) actuator are demonstrated. In this study, the physical scaling of electrodes for 33 μm and 21 μm EWD devices resulted in droplets of 12 pl and 5 pl being dispensed respectively in conjunction with 3 μm SU8 gaskets. The stacked multi-layer insulators in the actuators consisted of 200 nm tantalum pentoxide (Ta2O5) and 200 nm parylene C films deposited and coated with 70 nm of CYTOP. The voltages for dispensing droplets on chips without any external pressure sources are 17.1 Vrms and 22 Vrms for these two sets of devices. A 12 pl droplet can be split into two 6 pl daughter droplets at 18.7 Vrms with 33 μm electrode devices. Droplet manipulation is also demonstrated with paramagnetic beads and buffer solutions with proteins. In addition, electrodes with interlocking protrusions and special featured reservoir gasket are designed to facilitate droplet dispensing on these scaled EWD devices. In order to improve sealing of the two-piece sandwich EWD structure, a soft material, Norland Optical Adhesive (NOA), was coated on the top plate along with pressure on top. We demonstrate that based on fundamental theories and experiments, the dimensional scaling of EWD devices has not yet met a limitation as long as the EWD device can be sealed well. PMID:23559693

Analysis of water microdroplet condensation on silicon surfaces

NASA Astrophysics Data System (ADS)

Honda, Takuya; Fujimoto, Kenya; Yoshimoto, Yuta; Mogi, Katsuo; Kinefuchi, Ikuya; Sugii, Yasuhiko; Takagi, Shu; Univ. of Tokyo Team; Tokyo Inst. of Tech. Team

2016-11-01

We observed the condensation process of water microdroplets on flat silicon (100) surfaces by means of the sequential visualization of the droplets using an environmental scanning electron microscope. As previously reported for nanostructured surfaces, the condensation process of water microdroplets on the flat silicon surfaces also exhibits two modes: the constant base (CB) area mode and the constant contact angle (CCA) mode. In the CB mode, the contact angle increases with time while the base diameter is constant. Subsequently, in the CCA mode, the base diameter increases with time while the contact angle remains constant. The dropwise condensation model regulated by subcooling temperature does not reproduce the experimental results. Because the subcooling temperature is not constant in the case of a slow condensation rate, this model is not applicable to the condensation of the long time scale ( several tens of minutes). The contact angle of water microdroplets ( several μm) tended to be smaller than the macro contact angle. Two hypotheses are proposed as the cause of small contact angles: electrowetting and the coalescence of sub- μm water droplets.

Coalescence of liquid droplets in micro fluidic device

NASA Astrophysics Data System (ADS)

Wu, Mingming; Cubaud, Thomas; Ho, Chih-Ming; Chiou, Peiyu; Wu, Ming C.

2003-11-01

We study experimentally the initial dynamic process when two droplets (diameter range 100μm -1000μm) merge in micro fluidic device. It is known that passive mixing in micro fluidic device relies mostly on a time consuming process - diffusion. In digital fluidic platform,(S.K. Cho, H. Moon, and C.J. Kim, J. of Microelectromechanical Systems, Vol 12, No 1, 70(2003).) we find that the surface-tension-driven flow at the initial stage of the merging can be used to enhance mixing. In our experiments, the droplets are manipulated by two different methods, and results are compared. In one method, the droplet is manipulated by pressure driven flow in micro channels, and in the other, the droplet is moved using an optical electro-wetting device. The droplet is seeded with 4 μm diameter latex particles for visualizing the mixing process. The outlines of the droplets as well as the flow patterns marked by the latex particles inside the droplets are recorded using a high speed imaging system. This work is supported by the National Science Foundation (CTS-0121340), Institute for CMISE (a NASA URETI), DARPA MPG program, and DARPA Optoelectronics Center Program (CHIPS).

Liquid Drop Actuation by Photoelectrowetting

NASA Astrophysics Data System (ADS)

Palma, Cesar

In electrowetting an electric potential is applied between a droplet of electrolyte and a conductor separated by an insulator. The repulsion of like charges deforms and spreads the droplet until capillary and electric forces are in equilibrium. Photoelectrowetting is a light-triggered version of electrowetting where the conductor is replaced by a moderately-doped semiconductor. The electrolyte-insulator-semiconductor stack resembles a metal-insulator-semiconductor capacitor, which has the special property that the amount of charge that can be injected into it increases when exposed to light. Thus in photoelectrowetting the exposure of light spreads the droplet further than in unilluminated conditions. In this thesis a scheme is presented for moving drops on a surface using photoelectrowetting. In order to understand photoelectrowetting I conducted a study of electrowetting with semiconductors. Devices were constructed using moderately-doped p-type silicon wafers (Na = 8.6 x 1014 cm-3) coated with a bilayer composed of thermal oxide (100 nm) and teflon (265 nm). Electric biases (< 40 V) were applied between droplets of electrolyte (10 microliter, 10 mM NaCl) and the silicon wafer, resulting in deformations of the droplet. These changes were quantified with contact angle measurements which varied from 120° at zero bias to 90° at 40V depending on the conditions of the experiment. Three regimes were observed depending on the polarity of the bias and above-bandgap illumination impinging on the droplet, corresponding to the charge regimes of an MIS capacitor: accumulation, inversion and deep-depletion. I present a model for these wetting changes based on a balance of capillary and electrostatic forces. After accounting for various non-ideal effects, I find that the model agrees with the data. I demonstrate that it is essential to account for interface traps in our devices (1.8 x 1011 cm-2) in the deep-depletion regime, leading to a 33% (4?) correction to the prediction at 40V. I elucidate the nature of the photoelectrowetting effect and find that contrary to reports in the literature the transition is not reversible by light alone. In the next phase of my thesis, I demonstrate how photoelectrowetting triggered with a light beam on one side moves the droplet along a surface. Comparable with traditional electrowetting-based devices, I achieve speeds of up to 12 mm/s with 10 microliter drops of electrolyte (1% w/w NaCl) with a surfactant (5 mM NaCl) using an oscillating electric potential composed of an AC bias of magnitude 32.5 Vpp and a DC offset of -7 V cycled at a frequency of 15 kHz and a laser intensity of 40 mW/cm2 (lambda = 660nm). I measure the speed for varying magnitude and frequency of the bias, laser intensity, droplet size and viscosity. The optimal cycling frequency is set by competing effects: on the low frequency side (< 15 kHz) the speed is limited by migration of carriers from the illuminated to the non-illuminated regions under the drop, and on the high frequency side (> 15 kHz) the speed is limited by the laser intensity. I present a model for the speed incorporating these effects that compares favorably with experiment. I present results of simulations of minority charge carrier concentrations in depletion regions. These exhibit self-similarity in space and time. The front of the concentrations follows a power law in time with an exponent that depends on the dopant concentration. Predictions from the power laws compare favorably with experiment.

Microhydraulic Electrowetting Actuators

DTIC Science & Technology

2015-06-26

inkjet  printers4, and microrobots5 tend to use other  forms of actuation.   The alternatives can be widely divided  into  resistive and capacitive...actuators, based on  the primary  impedance mode.   Some examples of  resistive actuators are  thermal  inkjet  printers, electro‐osmotic pumps6, and shape

Introduction to the development of intraocular lens

NASA Astrophysics Data System (ADS)

Li, Yifan; Peng, Runling; Hu, Shuilan; Wei, Maowei; Chen, Jiabi

2013-08-01

In order to cure the cataract disease or injuries in eyes, intraocular lens(IOL) has been studied all the time to replace the crystalline lens in human eyes. Researches on IOL are started early from 19th century, and it develops greatly in the hundreds years after. This article introduces several main kinds of IOLs that appear in the development history of IOL, and raises the double-liquid zoom IOL based on electrowetting, which will be the trend of IOL study.

Variable-focus liquid lens for portable applications

NASA Astrophysics Data System (ADS)

Kuiper, Stein; Hendriks, Benno H.; Huijbregts, Laura J.; Hirschberg, A. Mico; Renders, Christel A.; van As, Marco A.

2004-10-01

The meniscus between two immiscible liquids can be used as an optical lens. A change in curvature of this meniscus by electrowetting leads to a change in focal distance. We demonstrate that two liquids in a tube form a self-centered tunable lens of high optical quality. Several properties were studied, such as optical performance, electrical characteristics and dynamic behavior. We designed and constructed a miniature camera module based on this tunable lens and show that it is very well suited for use in portable applications.

Tunable Surface Hydrophobicity and Fluid Transport through Nanoporous Membranes

NASA Astrophysics Data System (ADS)

Ostrowski, Joseph H. J.

There are more than three billion people across the globe that struggle to obtain clean drinkable water. One of the most promising avenues for generating potable water is through reverse osmosis and nanofiltration. Both solutions require a semipermeable membrane that prohibits passage of unwanted solute particles but allows passage of the solvent. Atomically thin two-dimensional membranes based on porous graphene show great promise as semipermeable materials, but modeling fluid flow on length scales between the microscopic (nanometer and smaller) and macroscopic (micron and larger) regimes presents formidable challenges. This thesis explores both equilibrium and nonequilibrium aspects of this problem and develops new methodology for simulating systems away from thermal equilibrium. First, we hypothesize that there is a wetting penalty for water as it tries to breach a sheet of graphene that should be naturally hydrophobic. By using equilibrium molecular dynamics simulations, we show that the hydrophobicity depends sensitively on the degree of electrical doping, offering an opportunity to tune the hydrophobic effect of graphene using small amounts of doping. The wetting contact angle, a measure of hydrophobicity, changes dramatically with the voltage applied to single layer graphene. We find that the sensitivity of the hydrophobic effect to voltage depends not on hydrogen bonding motifs at the interface between graphene and water, but instead on a phenomenon known as electrowetting. The theory of electrowetting predicts that the difference in surface tensions that defines the contact angle is quartic in the voltage, rather than quadratic, as it would be in bilayer graphene or in a two-dimensional metal. To explore the nonequilibrium aspects of fluid passage through atomically thin membranes, we developed a molecular dynamics methodology for simulating fluid flow at constant flux based on Gauss's principle of least constraint. This method develops microscopic equations of motion that satisfy specified constraints on the kinetic temperature and total mass flux. As a proof of principle, we simulate the flow of a simple monoatomic fluid and observe emergent and collective behaviors consistent with both known hydrodynamic solutions and expectations for velocity distributions from statistical mechanics. We compare results from the Gauss method simulations with that of a method commonly used in the literature. By computing the relationship between the pressure drop across a pipe-like region and the fluid current through it, we find that these two methods agree quantitatively with one another and comment on the advantages and disadvantages for both methods.

Wavefront shaping with an electrowetting liquid lens using surface harmonics (Conference Presentation)

NASA Astrophysics Data System (ADS)

Strauch, Matthias; Konijnenberg, Sander; Shao, Yifeng; Urbach, H. Paul

2017-02-01

Liquid lenses are used to correct for low order wavefront aberrations. Electrowetting liquid lenses can nowadays control defocus and astigmatism effectively, so they start being used for ophthalmology applications. To increase the performance and applicability, we introduce a new driving mechanism to create, detect and correct higher order aberrations using standing waves on the liquid interface. The speed of a liquid lens is in general limited, because the liquid surface cannot follow fast voltage changes, while providing a spherical surface. Surface waves are created instead and with them undesired aberrations. We try to control those surface waves to turn them into an effective wavefront shaping tool. We introduce a model, which treats the liquid lens as a circular vibrating membrane with adjusted boundary conditions. Similar to tunable acoustic gradient (TAG) lenses, the nature of the surface modes are predicted to be Bessel functions. Since Bessel functions are a full set of orthogonal basis functions any surface can be created as a linear combination of different Bessel functions. The model was investigated experimentally in two setups. First the point spread functions were studied and compared to a simulation of the intensity distribution created by Fresnel propagated Bessel surfaces. Second the wavefronts were measured directly using a spatial light modulator. The surface resonance frequencies confirm the predictions made by the model as well as the wavefront measurements. By superposition of known surface modes, it is possible to create new surface shapes, which can be used to simulate and measure the human eye.

Correction of a liquid lens for 3D imaging systems

NASA Astrophysics Data System (ADS)

Bower, Andrew J.; Bunch, Robert M.; Leisher, Paul O.; Li, Weixu; Christopher, Lauren A.

2012-06-01

3D imaging systems are currently being developed using liquid lens technology for use in medical devices as well as in consumer electronics. Liquid lenses operate on the principle of electrowetting to control the curvature of a buried surface, allowing for a voltage-controlled change in focal length. Imaging systems which utilize a liquid lens allow extraction of depth information from the object field through a controlled introduction of defocus into the system. The design of such a system must be carefully considered in order to simultaneously deliver good image quality and meet the depth of field requirements for image processing. In this work a corrective model has been designed for use with the Varioptic Arctic 316 liquid lens. The design is able to be optimized for depth of field while minimizing aberrations for a 3D imaging application. The modeled performance is compared to the measured performance of the corrected system over a large range of focal lengths.

Applications of variable focus liquid lenses for curvature wave-front sensors in astronomy

NASA Astrophysics Data System (ADS)

Fuentes-Fernández, J.; Cuevas, S.; Alvarez-Nuñez, L. C.; Watson, A. M.

2014-08-01

Curvature wavefront sensors obtain the wave-front aberrations from two defocused intensity images at each side of the pupil plane. Typically, when high modulation speeds are required, as it is the case with Adaptive Optics, that defocusing is done with a fast vibrating membrane mirror. We propose an alternative defocusing mechanism based on an electrowetting variable focus liquid lens. The use of such lenses may perform the required focus modulation without the need of extra moving parts, reducing the overall size of the system.

Variable-focus liquid lens for miniature cameras

NASA Astrophysics Data System (ADS)

Kuiper, S.; Hendriks, B. H. W.

2004-08-01

The meniscus between two immiscible liquids can be used as an optical lens. A change in curvature of this meniscus by electrowetting leads to a change in focal distance. It is demonstrated that two liquids in a tube form a self-centered lens with a high optical quality. The motion of the lens during a focusing action was studied by observation through the transparent tube wall. Finally, a miniature achromatic camera module was designed and constructed based on this adjustable lens, showing that it is excellently suited for use in portable applications.

Microfluidic Lab-on-a-Chip Platforms: Requirements, Characteristics and Applications

NASA Astrophysics Data System (ADS)

Mark, D.; Haeberle, S.; Roth, G.; Von Stetten, F.; Zengerle, R.

This review summarizes recent developments in microfluidic platform approaches. In contrast to isolated application-specific solutions, a microfluidic platform provides a set of fluidic unit operations, which are designed for easy combination within a well-defined fabrication technology. This allows the implementation of different application-specific (bio-) chemical processes, automated by microfluidic process integration [1]. A brief introduction into technical advances, major market segments and promising applications is followed by a detailed characterization of different microfluidic platforms, comprising a short definition, the functional principle, microfluidic unit operations, application examples as well as strengths and limitations. The microfluidic platforms in focus are lateral flow tests, linear actuated devices, pressure driven laminar flow, microfluidic large scale integration, segmented flow microfluidics, centrifugal microfluidics, electro-kinetics, electrowetting, surface acoustic waves, and systems for massively parallel analysis. The review concludes with the attempt to provide a selection scheme for microfluidic platforms which is based on their characteristics according to key requirements of different applications and market segments. Applied selection criteria comprise portability, costs of instrument and disposable, sample throughput, number of parameters per sample, reagent consumption, precision, diversity of microfluidic unit operations and the flexibility in programming different liquid handling protocols.

An inkjet-printed electrowetting valve for paper-fluidic sensors.

PubMed

Koo, Charmaine K W; He, Fei; Nugen, Sam R

2013-09-07

Paper-fluidic devices have become an emerging trend for micro total analysis systems (microTAS) in the bioengineering field due to their ability to maintain the rapid, sensitive and specific attributes of microfluidic devices. Subsequently, paper-fluidic devices are also more portable, have a lower production cost and are easier to use. However, one of the obstacles in developing paper fluidic devices is the limited ability to control the rate of fluid flow during an assay. In our project, we use electrowetting on dielectrics where a dielectric, which is normally hydrophobic, is polarized and becomes hydrophilic. We have fabricated paper-fluidic devices by inkjet printing and spraying conductive hydrophobic electrodes/valves in conjunction with conductive hydrophilic electrodes which are able to stop the fluid front of phosphate buffered saline (PBS). The hydrophobic valves were then actuated by an applied potential which altered the fluorinated monolayer on the electrode. As the applied potential between the electrodes was increased, the amount of time for the fluid front to pass the valve decreased because the monolayer was altered faster. However, we did not observe significant differences in time as we increased the distance between the electrodes. The valves were also incorporated in a lateral flow assay where the device was used to detect Saccharomyces cerevisiae rRNA sequences. With the ability to control the fluid flow in a paper-fluidic device, more complex and intricate assays can be developed, which not only can be applied in the biomedical, food and environmental fields, but also can be used in low resource settings for the detection of diseases.

Electrowetting-Based Variable-Focus Lens for Miniature Systems

NASA Astrophysics Data System (ADS)

Hendriks, B. H. W.; Kuiper, S.; van As, M. A. J.; et al.

The meniscus between two immiscible liquids of different refractive indices can be used as a lens. A change in curvature of this meniscus by electrostatic control of the solid/liquid interfacial tension leads to a change in focal distance. It is demonstrated that two liquids in a tube form a self-centred variable-focus lens. The optical properties of this lens were investigated experimentally. We designed and constructed a miniature camera module based on this variable lens suitable for mobile applications. Furthermore, the liquid lens was applied in a Blu-ray Disc optical recording system to enable dual layer disc reading/writing.

Variable focus photographic lens without mechanical movements

NASA Astrophysics Data System (ADS)

Chen, Jiabi; Peng, Runling; Zhuang, Songlin

2007-09-01

A novel design of a zoom lens system without motorized movements is proposed. The lens system consists of a fixed lens and two double-liquid variable-focus lenses. The liquid lenses, made out of two immiscible liquids, are based on the principle of electrowetting: an effect controlling the wetting properties of a liquid on a solid by modifying the applied voltage at the solid-liquid interface. The structure and principle of the lens system are introduced in this paper. And detailed calculations and simulation examples are presented to predict how two liquid lenses are related to meet the basic requirements of zoom lenses.

Design of a zoom lens without motorized optical elements

NASA Astrophysics Data System (ADS)

Peng, Runling; Chen, Jiabi; Zhu, Cheng; Zhuang, Songlin

2007-05-01

A novel design of a zoom lens system without motorized movements is proposed. The lens system consists of a fixed lens and two double-liquid variable-focus lenses. The liquid lenses, made out of two immiscible liquids, are based on the principle of electrowetting: an effect controlling the wetting properties of a liquid on a solid by modifying the applied voltage at the solid-liquid interface. The structure and principle of the lens system are introduced in this paper. Detailed calculations and simulation examples are presented to show that this zoom lens system appears viable as the next-generation zoom lens.

Design of a zoom lens without motorized optical elements.

PubMed

Peng, Runling; Chen, Jiabi; Zhu, Cheng; Zhuang, Songlin

2007-05-28

A novel design of a zoom lens system without motorized movements is proposed. The lens system consists of a fixed lens and two double-liquid variable-focus lenses. The liquid lenses, made out of two immiscible liquids, are based on the principle of electrowetting: an effect controlling the wetting properties of a liquid on a solid by modifying the applied voltage at the solid-liquid interface. The structure and principle of the lens system are introduced in this paper. Detailed calculations and simulation examples are presented to show that this zoom lens system appears viable as the next-generation zoom lens.

Electrowetting on semiconductors

NASA Astrophysics Data System (ADS)

Palma, Cesar; Deegan, Robert

2015-01-01

Applying a voltage difference between a conductor and a sessile droplet sitting on a thin dielectric film separating it from the conductor will cause the drop to spread. When the conductor is a good metal, the change of the drop's contact angle due to the voltage is given by the Young-Lippmann (YL) equation. Here, we report experiments with lightly doped, single crystal silicon as the conductive electrode. We derive a modified YL equation that includes effects due to the semiconductor and contact line pinning. We show that light induces a non-reversible wetting transition, and that our model agrees well with our experimental results.

Macro to microfluidics system for biological environmental monitoring.

PubMed

Delattre, Cyril; Allier, Cédric P; Fouillet, Yves; Jary, Dorothée; Bottausci, Frederic; Bouvier, Denis; Delapierre, Guillaume; Quinaud, Manuelle; Rival, Arnaud; Davoust, Laurent; Peponnet, Christine

2012-01-01

Biological environmental monitoring (BEM) is a growing field of research which challenges both microfluidics and system automation. The aim is to develop a transportable system with analysis throughput which satisfies the requirements: (i) fully autonomous, (ii) complete protocol integration from sample collection to final analysis, (iii) detection of diluted molecules or biological species in a large real life environmental sample volume, (iv) robustness and (v) flexibility and versatility. This paper discusses all these specifications in order to define an original fluidic architecture based on three connected modules, a sampling module, a sample preparation module and a detection module. The sample preparation module highly concentrates on the pathogens present in a few mL samples of complex and unknown solutions and purifies the pathogens' nucleic acids into a few μL of a controlled buffer. To do so, a two-step concentration protocol based on magnetic beads is automated in a reusable macro-to-micro fluidic system. The detection module is a PCR based miniaturized platform using digital microfluidics, where reactions are performed in 64 nL droplets handled by electrowetting on dielectric (EWOD) actuation. The design and manufacture of the two modules are reported as well as their respective performances. To demonstrate the integration of the complete protocol in the same system, first results of pathogen detection are shown. Copyright © 2012 Elsevier B.V. All rights reserved.

Demonstration of a wireless driven MEMS pond skater that uses EWOD technology

NASA Astrophysics Data System (ADS)

Mita, Y.; Li, Y.; Kubota, M.; Morishita, S.; Parkes, W.; Haworth, L. I.; Flynn, B. W.; Terry, J. G.; Tang, T.-B.; Ruthven, A. D.; Smith, S.; Walton, A. J.

2009-07-01

A silicon swimming robot or pond skating device has been demonstrated. It floats on liquid surfaces using surface tension and is capable of movement using electrowetting on dielectric (EWOD) based propulsion. Its dimensions are 6 × 9 mm and the driving mechanism involves first trapping air bubbles within the liquid onto the hydrophobic surface of the device. The air bubbles are then moved using EWOD, which provides the propulsion. The device employs a recently reported TaO EWOD technology enabling a driving voltage of ≈15 V, which is low enough for RF power transmission, thus facilitating wire-free movement. A wired version has been measured to move 1.35 mm in 168 ms (a speed of 8 mm s -1). This low voltage-EWOD (<15 V) device, fabricated using a CMOS compatible process, is believed to be the world's smallest swimming MEMS device that has no mechanical moving parts. The paper also reports results of EWOD droplet operation driven by wireless power transmission and demonstrates that such a wireless design can be successfully mounted on a floating EWOD device to produce movement.

Micro-chemical synthesis of molecular probes on an electronic microfluidic device

PubMed Central

Keng, Pei Yuin; Chen, Supin; Ding, Huijiang; Sadeghi, Saman; Shah, Gaurav J.; Dooraghi, Alex; Phelps, Michael E.; Satyamurthy, Nagichettiar; Chatziioannou, Arion F.; Kim, Chang-Jin “CJ”; van Dam, R. Michael

2012-01-01

We have developed an all-electronic digital microfluidic device for microscale chemical synthesis in organic solvents, operated by electrowetting-on-dielectric (EWOD). As an example of the principles, we demonstrate the multistep synthesis of [18F]FDG, the most common radiotracer for positron emission tomography (PET), with high and reliable radio-fluorination efficiency of [18F]FTAG (88 ± 7%, n = 11) and quantitative hydrolysis to [18F]FDG (> 95%, n = 11). We furthermore show that batches of purified [18F]FDG can successfully be used for PET imaging in mice and that they pass typical quality control requirements for human use (including radiochemical purity, residual solvents, Kryptofix, chemical purity, and pH). We report statistical repeatability of the radiosynthesis rather than best-case results, demonstrating the robustness of the EWOD microfluidic platform. Exhibiting high compatibility with organic solvents and the ability to carry out sophisticated actuation and sensing of reaction droplets, EWOD is a unique platform for performing diverse microscale chemical syntheses in small volumes, including multistep processes with intermediate solvent-exchange steps. PMID:22210110

Optimization and limit of a tilt manipulation stage based on the electrowetting-on-dielectric principle

NASA Astrophysics Data System (ADS)

Tan, Xiao; Tao, Zhi; Suzuki, Kenji; Li, Haiwang

2017-12-01

This work designed a new tilt manipulation stage based on the electrowetting-on-dielectric (EWOD) principle as the actuating mechanism and investigated the performance of that stage. The stage was fabricated using a universal MEMS (Micro-Electro-Mechanical System) fabrication method. In the previously demonstrated form of this device, the tilt stage consisted of a top plate that functions as a mirror, a bottom plate that was designed for changing the shape of water droplets, and supporters that were fixed between the top and bottom plate. That device was actuated by a voltage applied to the bottom plate, resulting in a static electric force actuating the shape change in the droplets by moving the top plate in the vertical direction. Previous experimental results indicated that that device can tilt at up to ±1.8°, with a resolution of 7 μm in displacement and 0.05° in angle. By selecting the best combination of the dielectric layer, the tilt angle was maximized. The new device, fabricated using a common and straightforward fabrication method, avoids deflection of the top plate and grounding in the bottom plate. Because of the limit of Teflon and other MEMS materials, this device has a tilt angle in the range of 3.2-3.5° according to the experimental data for friction and the EWOD device limit, which is close to 1.8°. This paper also describe the investigation of the effects of various parameters, e.g., various dielectric materials, thicknesses, and droplet type and volume, on the performance of the stage. The results indicate that the apparent frictions coefficient of the solid-liquid interface may remain constant, i.e., the friction force is proportional to the normal support force and the apparent frictions coefficient.

Bifocal liquid lens zoom objective for mobile phone applications

NASA Astrophysics Data System (ADS)

Wippermann, F. C.; Schreiber, P.; Bräuer, A.; Craen, P.

2007-02-01

Miniaturized camera systems are an integral part of today's mobile phones which recently possess auto focus functionality. Commercially available solutions without moving parts have been developed using the electrowetting technology. Here, the contact angle of a drop of a conductive or polar liquid placed on an insulating substrate can be influenced by an electric field. Besides the compensation of the axial image shift due to different object distances, mobile phones with zoom functionality are desired as a next evolutionary step. In classical mechanically compensated zoom lenses two independently driven actuators combined with precision guides are needed leading to a delicate, space consuming and expansive opto-mechanical setup. Liquid lens technology based on the electrowetting effect gives the opportunity to built adaptive lenses without moving parts thus simplifying the mechanical setup. However, with the recent commercially available liquid lens products a completely motionless and continuously adaptive zoom system with market relevant optical performance is not feasible. This is due to the limited change in optical power the liquid lenses can provide and the dispersion of the used materials. As an intermediate step towards a continuously adjustable and motionless zoom lens we propose a bifocal system sufficient for toggling between two effective focal lengths without any moving parts. The system has its mechanical counterpart in a bifocal zoom lens where only one lens group has to be moved. In a liquid lens bifocal zoom two groups of adaptable liquid lenses are required for adjusting the effective focal length and keeping the image location constant. In order to overcome the difficulties in achromatizing the lens we propose a sequential image acquisition algorithm. Here, the full color image is obtained from a sequence of monochrome images (red, green, blue) leading to a simplified optical setup.

A Method to Manipulate Surface Tension of a Liquid Metal via Surface Oxidation and Reduction

PubMed Central

Dickey, Michael D.

2016-01-01

Controlling interfacial tension is an effective method for manipulating the shape, position, and flow of fluids at sub-millimeter length scales, where interfacial tension is a dominant force. A variety of methods exist for controlling the interfacial tension of aqueous and organic liquids on this scale; however, these techniques have limited utility for liquid metals due to their large interfacial tension. Liquid metals can form soft, stretchable, and shape-reconfigurable components in electronic and electromagnetic devices. Although it is possible to manipulate these fluids via mechanical methods (e.g., pumping), electrical methods are easier to miniaturize, control, and implement. However, most electrical techniques have their own constraints: electrowetting-on-dielectric requires large (kV) potentials for modest actuation, electrocapillarity can affect relatively small changes in the interfacial tension, and continuous electrowetting is limited to plugs of the liquid metal in capillaries. Here, we present a method for actuating gallium and gallium-based liquid metal alloys via an electrochemical surface reaction. Controlling the electrochemical potential on the surface of the liquid metal in electrolyte rapidly and reversibly changes the interfacial tension by over two orders of magnitude (~500 mN/m to near zero). Furthermore, this method requires only a very modest potential (< 1 V) applied relative to a counter electrode. The resulting change in tension is due primarily to the electrochemical deposition of a surface oxide layer, which acts as a surfactant; removal of the oxide increases the interfacial tension, and vice versa. This technique can be applied in a wide variety of electrolytes and is independent of the substrate on which it rests. PMID:26863045

Microfluidic Device for Sequential Injection and Flushing of Solutions and its Application to Immunosensing

NASA Astrophysics Data System (ADS)

Nashida, Norihiro; Suzuki, Hiroaki

A microfluidic system with injecting and flushing functions was developed. In the system, hydrophilic flow channels have a dry-film photoresist layer which facilitates the introduction of solutions from four injection ports. The injection and flushing of solutions are controlled by valves operated by electrowetting. The valves consist of gold working electrodes in the flow channels or a through-hole in the glass substrate. Solutions can be sequentially introduced through the injection ports into a reaction chamber and flushed through a valve in the through-hole. Necessary immunoassay steps can be conducted on the chip, and a target antibody can be detected electrochemically.

Ultrathin zoom lens system based on liquid lenses

NASA Astrophysics Data System (ADS)

Li, Lei; Liu, Chao; Wang, Qiong-Hua

2015-07-01

In this paper, we propose an ultrathin zoom lens system based on liquid lenses. The proposed system consists of an annular folded lens and three electrowetting liquid lenses. The annular folded lens has several concentric surfaces. The annular folded lens is used to get the main power and correct aberrations. The three liquid lenses are used to change the focal length and correct aberration. An analysis of the proposed system is presented along with the design, fabrication, and testing of a prototype. All the elements in the proposed system are very thin, so the system is an ultrathin zoom lens system, which has potential application as lightweight, thin, high-quality imagers for aerospace, consumer, and military applications.

Compartmental genomics in living cells revealed by single-cell nanobiopsy.

PubMed

Actis, Paolo; Maalouf, Michelle M; Kim, Hyunsung John; Lohith, Akshar; Vilozny, Boaz; Seger, R Adam; Pourmand, Nader

2014-01-28

The ability to study the molecular biology of living single cells in heterogeneous cell populations is essential for next generation analysis of cellular circuitry and function. Here, we developed a single-cell nanobiopsy platform based on scanning ion conductance microscopy (SICM) for continuous sampling of intracellular content from individual cells. The nanobiopsy platform uses electrowetting within a nanopipette to extract cellular material from living cells with minimal disruption of the cellular milieu. We demonstrate the subcellular resolution of the nanobiopsy platform by isolating small subpopulations of mitochondria from single living cells, and quantify mutant mitochondrial genomes in those single cells with high throughput sequencing technology. These findings may provide the foundation for dynamic subcellular genomic analysis.

Scalable Device for Automated Microbial Electroporation in a Digital Microfluidic Platform.

PubMed

Madison, Andrew C; Royal, Matthew W; Vigneault, Frederic; Chen, Liji; Griffin, Peter B; Horowitz, Mark; Church, George M; Fair, Richard B

2017-09-15

Electrowetting-on-dielectric (EWD) digital microfluidic laboratory-on-a-chip platforms demonstrate excellent performance in automating labor-intensive protocols. When coupled with an on-chip electroporation capability, these systems hold promise for streamlining cumbersome processes such as multiplex automated genome engineering (MAGE). We integrated a single Ti:Au electroporation electrode into an otherwise standard parallel-plate EWD geometry to enable high-efficiency transformation of Escherichia coli with reporter plasmid DNA in a 200 nL droplet. Test devices exhibited robust operation with more than 10 transformation experiments performed per device without cross-contamination or failure. Despite intrinsic electric-field nonuniformity present in the EP/EWD device, the peak on-chip transformation efficiency was measured to be 8.6 ± 1.0 × 10 8 cfu·μg -1 for an average applied electric field strength of 2.25 ± 0.50 kV·mm -1 . Cell survival and transformation fractions at this electroporation pulse strength were found to be 1.5 ± 0.3 and 2.3 ± 0.1%, respectively. Our work expands the EWD toolkit to include on-chip microbial electroporation and opens the possibility of scaling advanced genome engineering methods, like MAGE, into the submicroliter regime.

A versatile electrowetting-based digital microfluidic platform for quantitative homogeneous and heterogeneous bio-assays

NASA Astrophysics Data System (ADS)

Vergauwe, Nicolas; Witters, Daan; Ceyssens, Frederik; Vermeir, Steven; Verbruggen, Bert; Puers, Robert; Lammertyn, Jeroen

2011-05-01

Electrowetting-on-dielectric (EWOD) lab-on-a-chip systems have already proven their potential within a broad range of bio-assays. Nevertheless, research on the analytical performance of those systems is limited, yet crucial for a further breakthrough in the diagnostic field. Therefore, this paper presents the intrinsic possibilities of an EWOD lab-on-a-chip as a versatile platform for homogeneous and heterogeneous bio-assays with high analytical performance. Both droplet dispensing and splitting cause variations in droplet size, thereby directly influencing the assay's performance. The extent to which they influence the performance is assessed by a theoretical sensitivity analysis, which allows the definition of a basic framework for the reduction of droplet size variability. Taking advantage of the optimized droplet manipulations, both homogeneous and heterogeneous bio-assays are implemented in the EWOD lab-on-a-chip to demonstrate the analytical capabilities and versatility of the device. A fully on-chip enzymatic assay is realized with high analytical performance. It demonstrates the promising capabilities of an EWOD lab-on-a-chip in food-related and medical applications, such as nutritional and blood analyses. Further, a magnetic bio-assay for IgE detection using superparamagnetic nanoparticles is presented whereby the nanoparticles are used as solid carriers during the bio-assay. Crucial elements are the precise manipulation of the superparamagnetic nanoparticles with respect to dispensing and separation. Although the principle of using nano-carriers is demonstrated for protein detection, it can be easily extended to a broader range of bio-related applications like DNA sensing. In heterogeneous bio-assays the chip surface is actively involved during the execution of the bio-assay. Through immobilization of specific biological compounds like DNA, proteins and cells a reactive chip surface is realized, which enhances the bio-assay performance. To demonstrate this potential, on-chip adhesion islands are fabricated to immobilize MCF-7 human breast cancer cells. Viability studies are performed to assess the functionalization efficiency.

Compartmental Genomics in Living Cells Revealed by Single-Cell Nanobiopsy

PubMed Central

Actis, Paolo; Maalouf, Michelle; Kim, Hyunsung John; Lohith, Akshar; Vilozny, Boaz; Seger, R. Adam; Pourmand, Nader

2014-01-01

The ability to study the molecular biology of living single cells in heterogeneous cell populations is essential for next generation analysis of cellular circuitry and function. Here, we developed a single-cell nanobiopsy platform based on scanning ion conductance microscopy (SICM) for continuous sampling of intracellular content from individual cells. The nanobiopsy platform uses electrowetting within a nanopipette to extract cellular material from living cells with minimal disruption of the cellular milieu. We demonstrate the subcellular resolution of the nanobiopsy platform by isolating small subpopulations of mitochondria from single living cells, and quantify mutant mitochondrial genomes in those single cells with high throughput sequencing technology. These findings may provide the foundation for dynamic subcellular genomic analysis. PMID:24279711

Digital Microfluidics Assisted Sealing of Individual Magnetic Particles in Femtoliter-Sized Reaction Wells for Single-Molecule Detection.

PubMed

Decrop, Deborah; Ruiz, Elena Pérez; Kumar, Phalguni Tewari; Tripodi, Lisa; Kokalj, Tadej; Lammertyn, Jeroen

2017-01-01

Digital microfluidics has emerged in the last years as a promising liquid handling technology for a variety of applications. Here, we describe in detail how to build up an electrowetting-on-dielectric-based digital microfluidic chip with unique advantages for performing single-molecule detection. We illustrate how superparamagnetic particles can be printed with very high loading efficiency (over 98 %) and single-particle resolution in the microwell array patterned in the Teflon-AF ® surface of the grounding plate of the chip. Finally, the potential of the device for its application to single-molecule detection is demonstrated by the ultrasensitive detection of the biotinylated enzyme β-Galactosidase captured on streptavidin-coated particles in the described platform.

Toward individually tunable compound eyes with transparent graphene electrode.

PubMed

Shahini, Ali; Jin, Hai; Zhou, Zhixian; Zhao, Yang; Chen, Pai-Yen; Hua, Jing; Cheng, Mark Ming-Cheng

2017-06-08

We present tunable compound eyes made of ionic liquid lenses, of which both curvatures (R 1 and R 2 in the lensmaker's equation) can be individually changed using electrowetting on dielectric (EWOD) and applied pressure. Flexible graphene is used as a transparent electrode and is integrated on a flexible polydimethylsiloxane (PDMS)/parylene hybrid substrate. Graphene electrodes allow a large lens aperture diameter of between 2.4 mm and 2.74 mm. Spherical aberration analysis is performed using COMSOL to investigate the optical property of the lens under applied voltage and pressure. The final lens system shows a resolution of 645.1 line pair per millimeter. A prototype of a tunable lens array is proposed for the application of a compound eye.

Theoretical analysis for double-liquid variable focus lens

NASA Astrophysics Data System (ADS)

Peng, Runling; Chen, Jiabi; Zhuang, Songlin

2007-09-01

In this paper, various structures for double-liquid variable focus lens are introduced. And based on an energy minimization method, explicit calculations and detailed analyses upon an extended Young-type equation are given for double-liquid lenses with cylindrical electrode. Such an equation is especially applicable to liquid-liquid-solid tri-phase systems. It is a little different from the traditional Young equation that was derived according to vapor-liquid-solid triphase systems. The electrowetting effect caused by an external voltage changes the interface shape between two liquids as well as the focal length of the lens. Based on the extended Young-type equation, the relationship between the focal length and the external voltage can also be derived. Corresponding equations and simulation results are presented.

Electrochemical immunoassay on a microfluidic device with sequential injection and flushing functions.

PubMed

Nashida, Norihiro; Satoh, Wataru; Fukuda, Junji; Suzuki, Hiroaki

2007-06-15

An integrated microfluidic device with injecting, flushing, and sensing functions was realized using valves that operate based on direct electrowetting. The device consisted of two substrates: a glass substrate with driving and sensing electrodes and a poly(dimethylsiloxane) (PDMS) substrate. Microfluidic transport was achieved using the spontaneous movement of solutions in hydrophilic flow channels formed with a dry-film photoresist layer. The injection and flushing of solutions were controlled by gold working electrodes, which functioned as valves. The valves were formed either in the channels or in a through-hole in the glass substrate. To demonstrate the system's applicability to an immunoassay, the detection of immobilized antigens was performed as a partial simulation of a sandwich immunoassay. Human alpha-fetoprotein (AFP) or an anti-human AFP antibody was immobilized on a platinum working electrode in the chamber using a plasma-polymerized film (PPF). By applying a potential to the injection valves, necessary solutions were injected one by one through the channels into a reaction chamber at the center of the chip and incubated for reasonable periods of time. The solutions were then flushed through the flushing valve and absorbed in a filter paper placed under the device. After incubation with the corresponding antibodies labeled with glucose oxidase (GOD), electrochemical detection was conducted. In both cases, the obtained current depended on the amount of immobilized antigen. The calibration curves were sigmoidal, and the detection limit was 0.1 ng. The developed microfluidic system could potentially be a fundamental component for a micro immunoassay of the next generation.

Controlling the Transient Interface Shape and Deposition Profile Left by Desiccation of Colloidal Droplets on Multiple Polymer Surfaces

NASA Astrophysics Data System (ADS)

Dunning, Peter David

A colloidal suspension is a small constituent of insoluble solid particles suspended in a liquid medium. Control over the wetting, evaporation, and deposition patterns left by colloidal suspensions is valuable in many biological, medical, industrial, and agricultural applications. Understanding the governing principles of wetting and evaporative phenomena of these colloidal suspensions may lead to greater control over resultant deposition patterns. Perhaps the most familiar pattern forms when an initially heterogeneous colloidal suspension leaves a dark ring pattern at the edge of a drop. This pattern is referred to as a coffee-stain and it can be seen from dried droplets of spilled coffee. This coffee-stain effect was first investigated by Deegan et. al. who discovered that these patterns occur when outward radial flows driven by evaporation at the triple contact line dominate over other effects. While the presence of coffee-stain patterns is undesirable in many printing and medical diagnostic processes, it can also be advantageous in the production of low cost transparent conductive films, the deposition of metal vapor, and the manipulation of biological structures. Controlling the interactions between the substrate, liquid, vapor, and particles can lead to control over the size and morphology of evaporative deposition patterns left by aqueous colloidal suspensions. Several methods have been developed to control the evaporation of colloidal suspensions to either suppress or enhance the coffee stain effect. Electrowetting on Dielectric (EWOD) is one promising method that has been used to control colloidal depositions by applying either an AC or DC electric field. EWOD actuation has the potential to dynamically control colloidal deposition left by desiccated droplets to either suppress or enhance the coffee stain effect. It may also allow for independent control of the fluidic interface and deposition of particles via electrowetting and electrokinetic forces. Implementation of this technique requires that the colloidal droplet be separated from the active electrode by a dielectric layer to prevent electrolysis. A variety of polymer layers have been used in EWOD devices for a variety of applications. In applications that involve desiccation of colloidal suspensions, the material for this layer should be chosen carefully as it can play an important role in the resulting deposition pattern. An experimental method to monitor the transient evolution of the shape of an evaporating colloidal droplet and optically quantify the resultant deposition pattern is presented. Unactuated colloidal suspensions will be desiccated on a variety of substrates commonly used in EWOD applications. Transient image profiles and particle deposition patterns are examined for droplets containing fluorescent micro-particles. Qualitative and quantitative comparisons of these results will be used to compare multiple different cases in an effort to provide insight into the effects of polymer selection on the drying dynamics and resultant deposition patterns of desiccated colloidal materials. It was found that the equilibrium and receding contact angles between the surface and the droplet play a key role in the evaporation dynamics and the resulting deposition patterns left by a desiccated colloidal suspension. The equilibrium contact angle controls the initial contact diameter for a droplet of a given volume. As a droplet on a surface evaporates, the evolution of the interface shape and the contact diameter can generally be described by three different regimes. The Constant Contact Radius (CCR) regime occurs when the contact line is pinned while the contact angle decreases. The Constant Contact Angle (CCA) regime occurs when the contact line recedes while the contact angle remains constant. The Mixed regime occurs when the contact radius and angle both reduce over time. The presence of the CCA regime allows the contact line to recede creating a more uniform deposition. However, not all droplets move into the CCA regime. Some remain in the CCR regime creating a coffee-stain pattern. In order to transition into the CCA regime, the dynamic contact angle of the droplet must be reduced to an angle close to the receding contact angle. Transient interface shapes and deposition patterns were examined on four surfaces: (i) Glass, (ii) Kapton HN polyimide tape, (iii) SU-8 3005, and (iv) Teflon AF. Glass has a low equilibrium contact angle and a very low receding contact angle resulting in a large uniform coffee-stain deposition. Kapton HN and SU-8 3005 have similar equilibrium contact angles that result in similar initial contact diameters. However, Kapton HN pins at that initial diameter due to a low receding contact angle producing a smaller more intense coffee-stain. SU-8 3005 has a large receding contact angle that allows for the transition into the CCA regime which results in a smaller, more uniform, and more intense spot. Teflon AF has the largest equilibrium and receding contact angle producing the smallest, most uniform, and most intense spot. Results presented here suggest that a lower receding contact angle is beneficial in areas where the coffee-stain effect needs to be enhanced while a larger receding contact angle is beneficial in areas where the coffee-stain needs to be suppressed. Preliminary results are also presented examining droplets actuated via AC electrowetting to examine the effect of electrode geometry and applied voltage on electrowetting behavior and colloidal depositions in these cases. It was found that the Young-Lippmann equation needs to be modified to satisfy the modified capacitance per unit area of a system with different electrode geometries.

A study of EWOD-driven droplets by PIV investigation.

PubMed

Lu, Hsiang-Wei; Bottausci, Frederic; Fowler, Jesse D; Bertozzi, Andrea L; Meinhart, Carl; Kim, Chang-Jin C J

2008-03-01

Despite the recent interest in droplet-based microfluidics using electrowetting-on-dielectric (EWOD), fundamental understanding of the fluid dynamics remains limited to two-dimensional (2D) reduction of the Navier-Stokes equation. Experimental data are in dire need to verify the predictions and advance the field. We report an investigation of the flow inside droplets actuated by EWOD in air using micro particle image velocimetry (micro-PIV). Using the continuity equation, we reconstruct the 3D velocity field from the 2D PIV experimental data. We present some fundamental findings and build valuable insights that will help design sophisticated EWOD microfluidic devices. For example, the results confirm that efficient mixing in a droplet may be achieved by moving the droplet along an irreversible pattern that breaks the symmetry of the two circulating inner flows.

Focal length hysteresis of a double-liquid lens based on electrowetting

NASA Astrophysics Data System (ADS)

Peng, Runling; Wang, Dazhen; Hu, Zhiwei; Chen, Jiabi; Zhuang, Songlin

2013-02-01

In this paper, an extended Young equation especially suited for an ideal cylindrical double-liquid variable-focus lens is derived by means of an energy minimization method. Based on the extended Young equation, a kind of focal length hysteresis effect is introduced into the double-liquid variable-focus lens. Such an effect can be explained theoretically by adding a force of friction to the tri-phase contact line. Theoretical analysis shows that the focal length at a particular voltage can be different depending on whether the applied voltage is increasing or decreasing, that is, there is a focal length hysteresis effect. Moreover, the focal length at a particular voltage must be larger when the voltage is rising than when it is dropping. These conclusions are also verified by experiments.

Versatile Miniature Tunable Liquid Lenses Using Transparent Graphene Electrodes.

PubMed

Shahini, Ali; Xia, Jinjun; Zhou, Zhixian; Zhao, Yang; Cheng, Mark Ming-Cheng

2016-02-16

This paper presents, for the first time, versatile and low-cost miniature liquid lenses with graphene as electrodes. Tunable focal length is achieved by changing the droplet curvature using electrowetting on dielectric (EWOD). Ionic liquid and KCl solution are utilized as lens liquid on the top of a flexible Teflon-coated PDMS/parylene membrane. Transparent and flexible, graphene allows transmission of visible light as well as large deformation of the polymer membrane to achieve requirements for different lens designs and to increase the field of view without damaging of electrodes. The tunable range for the focal length is between 3 and 7 mm for a droplet with a volume of 3 μL. The visualization of bone marrow dendritic cells is demonstrated by the liquid lens system with a high resolution (456 lp/mm).

Wettability Switching Techniques on Superhydrophobic Surfaces

PubMed Central

2007-01-01

The wetting properties of superhydrophobic surfaces have generated worldwide research interest. A water drop on these surfaces forms a nearly perfect spherical pearl. Superhydrophobic materials hold considerable promise for potential applications ranging from self cleaning surfaces, completely water impermeable textiles to low cost energy displacement of liquids in lab-on-chip devices. However, the dynamic modification of the liquid droplets behavior and in particular of their wetting properties on these surfaces is still a challenging issue. In this review, after a brief overview on superhydrophobic states definition, the techniques leading to the modification of wettability behavior on superhydrophobic surfaces under specific conditions: optical, magnetic, mechanical, chemical, thermal are discussed. Finally, a focus on electrowetting is made from historical phenomenon pointed out some decades ago on classical planar hydrophobic surfaces to recent breakthrough obtained on superhydrophobic surfaces.

Research on the relation between the contact angle and the interface curvature radius of electrowetting liquid zoom lens

NASA Astrophysics Data System (ADS)

Zhao, Cunhua; Liang, Huiqin; Cui, Dongqing; Hong, Xinhua; Wei, Daling; Gao, Changliu

2011-08-01

In the ultralight or ultrathin applied domain of zoom lens, the traditional glass / plastic lens is limited for manufacture technology or cost. Therefore, a liquid lens was put forward to solve the problems. The liquid zoom lens has the merits of lower cost, smaller volume, quicker response, lower energy consumption, continuous zoom and higher accuracy. In liquid zoom lens the precise focal length is obtained by the contact angle changing to affect the curvature radius of interface. In our works, the relations of the exerted voltage, the contact angle, the curvature radius and the focal length were researched and accurately calculated. The calculation of the focal length provides an important theoretical basis for instructing the design of liquid zoom lens.

Preparation and properties of ZnS superhydrophobic surface with hierarchical structure

NASA Astrophysics Data System (ADS)

Yao, Lujun; Zheng, Maojun; He, Shuanghu; Ma, Li; Li, Mei; Shen, Wenzhong

2011-01-01

A novel ZnS hierarchical structure composed of nanorod arrays with branched nanosheets and nanowires grown on their upside walls, was synthesized over Au-coated silicon substrate via chemical vapor deposition technique. Contact angle and sliding angle of this hierarchical film with no surface modification were measured to be about 153.8° and 9.1° for 5 μl water droplets. Self-cleaning behavior and dynamic water-repelling performance were clearly demonstrated. In addition, electrowetting transition phenomenon from superhydrophobic to hydrophilic state happened when a critical bias ∼7.0 V was applied. Below this threshold voltage, the contact angle change is little. This work for the first time reports the creation of ZnS superhydrophobic surface and could enrich its research field as surface functional materials.

Tunable liquid microlens array driven by pyroelectric effect: full interferometric characterization

NASA Astrophysics Data System (ADS)

Miccio, Lisa; Grilli, Simonetta; Vespini, Veronica; Ferraro, Pietro

2008-09-01

Liquid lenses with adjustable focal length are of great interest in the field of microfluidic devices. They are, usually, realized by electrowetting effect after electrodes patterning on a hydrofobic substrate. Applications are possible in many fields ranging from commercial products such as digital cameras to biological cell sorting. We realized an open array of liquid lenses with adjustable focal length without electrode patterning. We used a z-cut Lithium Niobate crystal (LN) as substrate and few microliters of an oily substance to obtain the droplets array. The spontaneous polarization of LN crystals is reversed by the electric field poling process, thus enabling the realization of periodically poled LN (PPLN) crystals. The substrate consists of a two-dimensional square array of reversed domains with a period around 200 μm. Each domain presents an hexagonal geometry due to the crystal structure. PPLN is first covered by a thin and homogeneous layer of the above mentioned liquid and therefore its temperature is changed by means of a digitally controlled hot plate. During heating and cooling process there is a rearrangement of the liquid layer until it reaches the final topography. Lenses formation is due to the superficial tension changing at the liquid-solid interface by means of the pyroelectric effect. Such effect allows to create a two-dimensional lens pattern of tunable focal length without electrodes. The temporal evolution of both shape and focal length lenses are quantitatively measured by Digital Holographic Microscopy. Array imaging properties and quantitative analysis of the lenses features and aberrations are presented.

Integrated sample-to-detection chip for nucleic acid test assays.

PubMed

Prakash, R; Pabbaraju, K; Wong, S; Tellier, R; Kaler, K V I S

2016-06-01

Nucleic acid based diagnostic techniques are routinely used for the detection of infectious agents. Most of these assays rely on nucleic acid extraction platforms for the extraction and purification of nucleic acids and a separate real-time PCR platform for quantitative nucleic acid amplification tests (NATs). Several microfluidic lab on chip (LOC) technologies have been developed, where mechanical and chemical methods are used for the extraction and purification of nucleic acids. Microfluidic technologies have also been effectively utilized for chip based real-time PCR assays. However, there are few examples of microfluidic systems which have successfully integrated these two key processes. In this study, we have implemented an electro-actuation based LOC micro-device that leverages multi-frequency actuation of samples and reagents droplets for chip based nucleic acid extraction and real-time, reverse transcription (RT) PCR (qRT-PCR) amplification from clinical samples. Our prototype micro-device combines chemical lysis with electric field assisted isolation of nucleic acid in a four channel parallel processing scheme. Furthermore, a four channel parallel qRT-PCR amplification and detection assay is integrated to deliver the sample-to-detection NAT chip. The NAT chip combines dielectrophoresis and electrostatic/electrowetting actuation methods with resistive micro-heaters and temperature sensors to perform chip based integrated NATs. The two chip modules have been validated using different panels of clinical samples and their performance compared with standard platforms. This study has established that our integrated NAT chip system has a sensitivity and specificity comparable to that of the standard platforms while providing up to 10 fold reduction in sample/reagent volumes.

Voltage-programmable liquid optical interface

NASA Astrophysics Data System (ADS)

Brown, C. V.; Wells, G. G.; Newton, M. I.; McHale, G.

2009-07-01

Recently, there has been intense interest in photonic devices based on microfluidics, including displays and refractive tunable microlenses and optical beamsteerers that work using the principle of electrowetting. Here, we report a novel approach to optical devices in which static wrinkles are produced at the surface of a thin film of oil as a result of dielectrophoretic forces. We have demonstrated this voltage-programmable surface wrinkling effect in periodic devices with pitch lengths of between 20 and 240 µm and with response times of less than 40 µs. By a careful choice of oils, it is possible to optimize either for high-amplitude sinusoidal wrinkles at micrometre-scale pitches or more complex non-sinusoidal profiles with higher Fourier components at longer pitches. This opens up the possibility of developing rapidly responsive voltage-programmable, polarization-insensitive transmission and reflection diffraction devices and arbitrary surface profile optical devices.

Integration of reconfigurable potentiometric electrochemical sensors into a digital microfluidic platform.

PubMed

Farzbod, Ali; Moon, Hyejin

2018-05-30

This paper presents the demonstration of on-chip fabrication of a potassium-selective sensor array enabled by electrowetting on dielectric digital microfluidics for the first time. This demonstration proves the concept that electrochemical sensors can be seamlessly integrated with sample preparation units in a digital microfluidic platform. More significantly, the successful on-chip fabrication of a sensor array indicates that sensors become reconfigurable and have longer lifetime in a digital microfluidic platform. The on-chip fabrication of ion-selective electrodes includes electroplating Ag followed by forming AgCl layer by chemical oxidation and depositing a thin layer of desired polymer-based ion selective membrane on one of the sensor electrodes. In this study, potassium ionophores work as potassium ion channels and make the membrane selective to potassium ions. This selectiveness results in the voltage difference across the membrane layer, which is correlated with potassium ion concentration. The calibration curve of the fabricated potassium-selective electrode demonstrates the slope of 58 mV/dec for potassium concentration in KCl sample solutions and shows good agreement with the ideal Nernstian response. The proposed sensor platform is an outstanding candidate for a portable home-use for continuous monitoring of ions thanks to its advantages such as easy automation of sample preparation and detection processes, elongated sensor lifetime, minimal membrane and sample consumption, and user-definable/reconfigurable sensor array. Copyright © 2018 Elsevier B.V. All rights reserved.

Direct-referencing Two-dimensional-array Digital Microfluidics Using Multi-layer Printed Circuit Board

PubMed Central

Gong, Jian; Kim, Chang-Jin “CJ”

2008-01-01

Digital (i.e. droplet-based) microfluidics, by the electrowetting-on-dielectric (EWOD) mechanism, has shown great potential for a wide range of applications, such as lab-on-a-chip. While most reported EWOD chips use a series of electrode pads essentially in one-dimensional line pattern designed for specific tasks, the desired universal chips allowing user-reconfigurable paths would require the electrode pads in two-dimensional pattern. However, to electrically access the electrode pads independently, conductive lines need to be fabricated underneath the pads in multiple layers, raising a cost issue especially for disposable chip applications. In this article, we report the building of digital microfluidic plates based on a printed-circuit-board (PCB), in which multilayer electrical access lines were created inexpensively using mature PCB technology. However, due to its surface topography and roughness and resulting high resistance against droplet movement, as-fabricated PCB surfaces require unacceptably high (~500 V) voltages unless coated with or immersed in oil. Our goal is EWOD operations of aqueous droplets not only on oil-covered but also on dry surfaces. To meet varying levels of performances, three types of gradually complex post-PCB microfabrication processes are developed and evaluated. By introducing land-grid-array (LGA) sockets in the packaging, a scalable digital microfluidics system with reconfigurable and low-cost chip is also demonstrated. PMID:19234613

Accurate, consistent, and fast droplet splitting and dispensing in electrowetting on dielectric digital microfluidics

NASA Astrophysics Data System (ADS)

Nikapitiya, N. Y. Jagath B.; Nahar, Mun Mun; Moon, Hyejin

2017-12-01

This letter reports two novel electrode design considerations to satisfy two very important aspects of EWOD operation—(1) Highly consistent volume of generated droplets and (2) Highly improved accuracy in the generated droplet volume. Considering the design principles investigated two novel designs were proposed; L-junction electrode design to offer high throughput droplet generation and Y-junction electrode design to split a droplet very fast while maintaining equal volume of each part. Devices of novel designs were fabricated and tested, and the results are compared with those of conventional approach. It is demonstrated that inaccuracy and inconsistency of droplet volume dispensed in the device with novel electrode designs are as low as 0.17 and 0.10%, respectively, while those of conventional approach are 25 and 0.76%, respectively. The dispensing frequency is enhanced from 4 to 9 Hz by using the novel design.

Electrically optofluidic zoom system with a large zoom range and high-resolution image.

PubMed

Li, Lei; Yuan, Rong-Ying; Wang, Jin-Hui; Wang, Qiong-Hua

2017-09-18

We report an electrically controlled optofluidic zoom system which can achieve a large continuous zoom change and high-resolution image. The zoom system consists of an optofluidic zoom objective and a switchable light path which are controlled by two liquid optical shutters. The proposed zoom system can achieve a large tunable focal length range from 36mm to 92mm. And in this tuning range, the zoom system can correct aberrations dynamically, thus the image resolution is high. Due to large zoom range, the proposed imaging system incorporates both camera configuration and telescope configuration into one system. In addition, the whole system is electrically controlled by three electrowetting liquid lenses and two liquid optical shutters, therefore, the proposed system is very compact and free of mechanical moving parts. The proposed zoom system has potential to take place of conventional zoom systems.

Liquid lens enabling real-time focus and tilt compensation for optical image stabilization in camera modules

NASA Astrophysics Data System (ADS)

Simon, Eric; Craen, Pierre; Gaton, Hilario; Jacques-Sermet, Olivier; Laune, Frédéric; Legrand, Julien; Maillard, Mathieu; Tallaron, Nicolas; Verplanck, Nicolas; Berge, Bruno

2010-05-01

A new generation of liquid lenses based on electrowetting has been developed, using a multi-electrode design, enabling to induce optical tilt and focus corrections in the same component. The basic principle is to rely on a conical shape for supporting the liquid interface, the conical shape insuring a restoring force for the liquid liquid interface to come at the center position. The multi-electrode design enables to induce an average tilt of the liquid liquid interface when a bias voltage is applied to the different electrodes. This tilt is reversible, vanishing when voltage bias is cancelled. Possible application of this new lens component is the realization of miniature camera featuring auto-focus and optical image stabilization (OIS) without any mobile mechanical part. Experimental measurements of actual performances of liquid lens component will be presented : focus and tilt amplitude, residual optical wave front error and response time.

Electrowetting-actuated zoom lens with spherical-interface liquid lenses.

PubMed

Peng, Runling; Chen, Jiabi; Zhuang, Songlin

2008-11-01

The interface shape of two immiscible liquids in a conical chamber is discussed. The analytical solution of the differential equation describing the interface shape shows that the interface shape is completely spherical when the density difference of two liquids is zero. On the basis of the spherical-interface shape and an energy-minimization method, explicit calculations and detailed analyses of an extended Young-type equation for the conical double-liquid lens are given. Finally, a novel design of a zoom lens system without motorized movements is proposed. The lens system consists of a fixed lens and two conical double-liquid variable-focus lenses. The structure and principle of the lens system are introduced in this paper. Taking finite objects as example, detailed calculations and simulation examples are presented to predict how two liquid lenses are related to meet the basic requirements of zoom lenses.

Smart lens: tunable liquid lens for laser tracking

NASA Astrophysics Data System (ADS)

Lin, Fan-Yi; Chu, Li-Yu; Juan, Yu-Shan; Pan, Sih-Ting; Fan, Shih-Kang

2007-05-01

A tracking system utilizing tunable liquid lens is proposed and demonstrated. Adapting the concept of EWOD (electrowetting-on-dielectric), the curvature of a droplet on a dielectric film can be controlled by varying the applied voltage. When utilizing the droplet as an optical lens, the focal length of this adaptive liquid lens can be adjusted as desired. Moreover, the light that passes through it can therefore be focused to different positions in space. In this paper, the tuning range of the curvature and focal length of the tunable liquid lens is investigated. Droplet transformation is observed and analyzed under a CCD camera. A tracking system combining the tunable liquid lens with a laser detection system is also proposed. With a feedback circuit that maximizing the returned signal by controlling the tunable lens, the laser beam can keep tracked on a distant reflected target while it is moving.

Field-Controlled Electrical Switch with Liquid Metal.

PubMed

Wissman, James; Dickey, Michael D; Majidi, Carmel

2017-12-01

When immersed in an electrolyte, droplets of Ga-based liquid metal (LM) alloy can be manipulated in ways not possible with conventional electrocapillarity or electrowetting. This study demonstrates how LM electrochemistry can be exploited to coalesce and separate droplets under moderate voltages of ~1-10 V. This novel approach to droplet interaction can be explained with a theory that accounts for oxidation and reduction as well as fluidic instabilities. Based on simulations and experimental analysis, this study finds that droplet separation is governed by a unique limit-point instability that arises from gradients in bipolar electrochemical reactions that lead to gradients in interfacial tension. The LM coalescence and separation are used to create a field-programmable electrical switch. As with conventional relays or flip-flop latch circuits, the system can transition between bistable (separated or coalesced) states, making it useful for memory storage, logic, and shape-programmable circuitry using entirely liquids instead of solid-state materials.

Electrical Textile Valves for Paper Microfluidics.

PubMed

Ainla, Alar; Hamedi, Mahiar M; Güder, Firat; Whitesides, George M

2017-10-01

This paper describes electrically-activated fluidic valves that operate based on electrowetting through textiles. The valves are fabricated from electrically conductive, insulated, hydrophobic textiles, but the concept can be extended to other porous materials. When the valve is closed, the liquid cannot pass through the hydrophobic textile. Upon application of a potential (in the range of 100-1000 V) between the textile and the liquid, the valve opens and the liquid penetrates the textile. These valves actuate in less than 1 s, require low energy (≈27 µJ per actuation), and work with a variety of aqueous solutions, including those with low surface tension and those containing bioanalytes. They are bistable in function, and are, in a sense, the electrofluidic analog of thyristors. They can be integrated into paper microfluidic devices to make circuits that are capable of controlling liquid, including autonomous fluidic timers and fluidic logic. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrowetting of Weak Polyelectrolyte-Coated Surfaces.

PubMed

Sénéchal, Vincent; Saadaoui, Hassan; Rodriguez-Hernandez, Juan; Drummond, Carlos

2017-05-23

Polymer coatings are commonly used to modify interfacial properties like wettability, lubrication, or biocompatibility. These properties are determined by the conformation of polymer molecules at the interface. Polyelectrolytes are convenient elementary bricks to build smart materials, given that polyion chain conformation is very sensitive to different environmental variables. Here we discuss the effect of an applied electric field on the properties of surfaces coated with poly(acrylic acid) brushes. By combining atomic force microscopy, quartz crystal microbalance, and contact angle experiments, we show that it is possible to precisely tune polyion chain conformation, surface adhesion, and surface wettability using very low applied voltages if the polymer grafting density and environmental conditions (pH and ionic strength) are properly formulated. Our results indicate that the effective ionization degree of the grafted weak polyacid can be finely controlled with the externally applied field, with important consequences for the macroscopic surface properties.

Droplet morphometry and velocimetry (DMV): a video processing software for time-resolved, label-free tracking of droplet parameters.

PubMed

Basu, Amar S

2013-05-21

Emerging assays in droplet microfluidics require the measurement of parameters such as drop size, velocity, trajectory, shape deformation, fluorescence intensity, and others. While micro particle image velocimetry (μPIV) and related techniques are suitable for measuring flow using tracer particles, no tool exists for tracking droplets at the granularity of a single entity. This paper presents droplet morphometry and velocimetry (DMV), a digital video processing software for time-resolved droplet analysis. Droplets are identified through a series of image processing steps which operate on transparent, translucent, fluorescent, or opaque droplets. The steps include background image generation, background subtraction, edge detection, small object removal, morphological close and fill, and shape discrimination. A frame correlation step then links droplets spanning multiple frames via a nearest neighbor search with user-defined matching criteria. Each step can be individually tuned for maximum compatibility. For each droplet found, DMV provides a time-history of 20 different parameters, including trajectory, velocity, area, dimensions, shape deformation, orientation, nearest neighbour spacing, and pixel statistics. The data can be reported via scatter plots, histograms, and tables at the granularity of individual droplets or by statistics accrued over the population. We present several case studies from industry and academic labs, including the measurement of 1) size distributions and flow perturbations in a drop generator, 2) size distributions and mixing rates in drop splitting/merging devices, 3) efficiency of single cell encapsulation devices, 4) position tracking in electrowetting operations, 5) chemical concentrations in a serial drop dilutor, 6) drop sorting efficiency of a tensiophoresis device, 7) plug length and orientation of nonspherical plugs in a serpentine channel, and 8) high throughput tracking of >250 drops in a reinjection system. Performance metrics show that highest accuracy and precision is obtained when the video resolution is >300 pixels per drop. Analysis time increases proportionally with video resolution. The current version of the software provides throughputs of 2-30 fps, suggesting the potential for real time analysis.

Graphene-coated meshes for electroactive flow control devices utilizing two antagonistic functions of repellency and permeability

PubMed Central

Tabassian, Rassoul; Oh, Jung-Hwan; Kim, Sooyeun; Kim, Donggyu; Ryu, Seunghwa; Cho, Seung-Min; Koratkar, Nikhil; Oh, Il-Kwon

2016-01-01

The wettability of graphene on various substrates has been intensively investigated for practical applications including surgical and medical tools, textiles, water harvesting, self-cleaning, oil spill removal and microfluidic devices. However, most previous studies have been limited to investigating the intrinsic and passive wettability of graphene and graphene hybrid composites. Here, we report the electrowetting of graphene-coated metal meshes for use as electroactive flow control devices, utilizing two antagonistic functions, hydrophobic repellency versus liquid permeability. Graphene coating was able to prevent the thermal oxidation and corrosion problems that plague unprotected metal meshes, while also maintaining its hydrophobicity. The shapes of liquid droplets and the degree of water penetration through the graphene-coated meshes were controlled by electrical stimuli based on the functional control of hydrophobic repellency and liquid permeability. Furthermore, using the graphene-coated metal meshes, we developed two active flow devices demonstrating the dynamic locomotion of water droplets and electroactive flow switching. PMID:27796291

Tunable liquid microlens arrays in electrode-less configuration and their accurate characterization by interference microscopy.

PubMed

Miccio, L; Finizio, A; Grilli, S; Vespini, V; Paturzo, M; De Nicola, S; Ferraro, Pietro

2009-02-16

A special class of tunable liquid microlenses is presented here. The microlenses are generated by an electrowetting effect under an electrode-less configuration and they exhibit two different regimes that are named here as separated lens regime (SLR) and wave-like lens regime (WLR). The lens effect is induced by the pyroelectricity of polar dielectric crystals, as was proved in principle in a previous work by the same authors (S. Grilli et al., Opt. Express 16, 8084, 2008). Compared to that work, the improvements to the experimental set-up and procedure allow to reveal the two lens regimes which exhibit different optical properties. A digital holography technique is used to reconstruct the transmitted wavefront during focusing and a focal length variation in the millimetre range is observed. The tunability of such microlenses could be of great interest to the field of micro-optics thanks to the possibility to achieve focus tuning without moving parts and thus favouring the miniaturization of the optical systems.

Tunable liquid optics: electrowetting-controlled liquid mirrors based on self-assembled Janus tiles.

PubMed

Bucaro, Michael A; Kolodner, Paul R; Taylor, J Ashley; Sidorenko, Alex; Aizenberg, Joanna; Krupenkin, Tom N

2009-04-09

In this paper, we describe a tunable, high-reflectivity optofluidic device based on self-assembly of anisotropically functionalized hexagonal micromirrors (Janus tiles) on the surface of an oil droplet to create a concave liquid mirror. The liquid mirror is deposited on a patterned transparent electrode that allows the focal length and axial position to be electrically controlled. The mirror is mechanically robust and retains its integrity even at high levels of vibrational excitation of the interface. The use of reflection instead of refraction overcomes the limited available refractive-index contrast between pairs of density-matched liquids, allowing stronger focusing than is possible for a liquid lens of the same geometry. This approach is compatible with optical instruments that could provide novel functionality-for example, a dynamic 3D projector, i.e., a light source which can scan an image onto a moving, nonplanar focal surface. Janus tiles with complex optical properties can be manufactured using our approach, thus potentially enabling a wide range of novel optical elements.

Tests and evaluation of a variable focus liquid lens for curvature wavefront sensors in astronomy.

PubMed

Fuentes-Fernández, Jorge; Cuevas, Salvador; Álvarez-Nuñez, Luis C; Watson, Alan

2013-10-20

Curvature wavefront sensors (WFSs), which obtain the wavefront aberrations from two defocused intensity images at each side of the pupil plane, have shown to be highly efficient for astronomical applications. We propose here an alternative defocusing mechanism for curvature sensors, based on an electrowetting-based variable focus liquid lens. Typically, the sampling rates of a WFS for active optics are of the order of 0.01 Hz, and the focus modulation can be done by simply moving the detector back and forth. On the other hand, adaptive optics may require speeds of up to several hundred hertz, and the modulation is then done by using a fast vibrating membrane mirror. We believe variable focus liquid lenses may be able to perform this focus modulation, reducing the overall size of the system and without the need of extra moving parts. We have done a full characterization of the Varioptic Arctic 416 liquid lens, and we have evaluated its potential performance in different curvature configurations.

Tunable liquid optics: electrowetting-controlled liquid mirrors based on self-assembled Janus tiles

NASA Astrophysics Data System (ADS)

Krupenkin, Tom; Bucaro, Mike; Kolodner, Paul; Taylor, Ashley; Sidorenko, Alex; Aizenberg, Joanna

2009-03-01

In this work we describe a tunable, high-reflectivity optofluidic device based on self-assembly of anisotropically-functionalized hexagonal micromirrors (Janus tiles) on the surface of an oil droplet to create a concave liquid mirror. The liquid mirror is deposited on a patterned transparent electrode that allows the focal length and axial position to be electrically controlled. The mirror is mechanically robust and retains its integrity even at high levels of vibrational excitation of the interface. The use of reflection instead of refraction overcomes the limited available refractive-index contrast between pairs of density-matched liquids, allowing stronger focusing than is possible for a liquid lens of the same geometry. This approach is compatible with optical instruments that could provide novel functionality - for example, a dynamic 3D projector; i.e., a light source which can scan an image onto a moving, non-planar focal surface. Janus tiles with complex optical properties can be manufactured using our approach, thus potentially enabling a wide range of novel optical elements.

Tubular astigmatism-tunable fluidic lens.

PubMed

Kopp, Daniel; Zappe, Hans

2016-06-15

We demonstrate a new means to fabricate three-dimensional liquid lenses which may be tuned in focal length and astigmatism. Using actuation by electrowetting-on-dielectrics, astigmatism in arbitrary directions may be tuned independently, with almost no cross talk between orthogonal orientations. The lens is based on electrodes structured on planar polyimide foils and subsequently rolled, enabling high-resolution patterning of complex electrodes along the azimuthal and radial directions of the lens. Based on a design established through fluidic and optical simulations, the astigmatism tuning is experimentally verified by a change of the corresponding Zernike coefficients measured using a Shack-Hartmann wavefront sensor. It was seen that the back focal length can be tuned by 5 mm and 0° and 45° astigmatism by 3 μm through application of voltages in the range of 50  V_rms. It was observed that the cross talk with other aberrations is very low, suggesting a novel means for astigmatism control in imaging systems.

Equilibrium shapes of a heterogeneous bubble in an electric field: a variational formulation and numerical verifications

NASA Astrophysics Data System (ADS)

Wang, Hanxiong; Liu, Liping; Liu, Dong

2017-03-01

The equilibrium shape of a bubble/droplet in an electric field is important for electrowetting over dielectrics (EWOD), electrohydrodynamic (EHD) enhancement for heat transfer and electro-deformation of a single biological cell among others. In this work, we develop a general variational formulation in account of electro-mechanical couplings. In the context of EHD, we identify the free energy functional and the associated energy minimization problem that determines the equilibrium shape of a bubble in an electric field. Based on this variational formulation, we implement a fixed mesh level-set gradient method for computing the equilibrium shapes. This numerical scheme is efficient and validated by comparing with analytical solutions at the absence of electric field and experimental results at the presence of electric field. We also present simulation results for zero gravity which will be useful for space applications. The variational formulation and numerical scheme are anticipated to have broad applications in areas of EWOD, EHD and electro-deformation in biomechanics.

Brownian motion as a new probe of wettability.

PubMed

Mo, Jianyong; Simha, Akarsh; Raizen, Mark G

2017-04-07

Understanding wettability is crucial for optimizing oil recovery, semiconductor manufacturing, pharmaceutical industry, and electrowetting. In this letter, we study the effects of wettability on Brownian motion. We consider the cases of a sphere in an unbounded fluid medium, as well as a sphere placed in the vicinity of a plane wall. For the first case, we show the effects of wettability on the statistical properties of the particles' motion, such as velocity autocorrelation, velocity, and thermal force power spectra over a large range of time scales. We also propose a new method to measure wettability based on the particles' Brownian motion. In addition, we compare the boundary effects on Brownian motion imposed by both no-slip and perfect-slip flat walls. We emphasize the surprising boundary effects on Brownian motion imposed by a perfect-slip wall in the parallel direction, such as a higher particle mobility parallel to a perfect flat wall compared to that in the absence of the wall, as well as compared to a particle near a no-slip flat wall.

Graphene-coated meshes for electroactive flow control devices utilizing two antagonistic functions of repellency and permeability.

PubMed

Tabassian, Rassoul; Oh, Jung-Hwan; Kim, Sooyeun; Kim, Donggyu; Ryu, Seunghwa; Cho, Seung-Min; Koratkar, Nikhil; Oh, Il-Kwon

2016-10-31

The wettability of graphene on various substrates has been intensively investigated for practical applications including surgical and medical tools, textiles, water harvesting, self-cleaning, oil spill removal and microfluidic devices. However, most previous studies have been limited to investigating the intrinsic and passive wettability of graphene and graphene hybrid composites. Here, we report the electrowetting of graphene-coated metal meshes for use as electroactive flow control devices, utilizing two antagonistic functions, hydrophobic repellency versus liquid permeability. Graphene coating was able to prevent the thermal oxidation and corrosion problems that plague unprotected metal meshes, while also maintaining its hydrophobicity. The shapes of liquid droplets and the degree of water penetration through the graphene-coated meshes were controlled by electrical stimuli based on the functional control of hydrophobic repellency and liquid permeability. Furthermore, using the graphene-coated metal meshes, we developed two active flow devices demonstrating the dynamic locomotion of water droplets and electroactive flow switching.

The contribution of local and transport processes to phytoplankton biomass variability over different timescales in the Upper James River, Virginia

NASA Astrophysics Data System (ADS)

Qin, Qubin; Shen, Jian

2017-09-01

Although both local processes (photosynthesis, respiration, grazing, and settling), and transport processes (advective transport and diffusive transport) significantly affect local phytoplankton dynamics, it is difficult to separate their contributions and to investigate the relative importance of each process to the local variability of phytoplankton biomass over different timescales. A method of using the transport rate is introduced to quantify the contribution of transport processes. By combining the time-varying transport rate and high-frequency observed chlorophyll a data, we can explicitly examine the impact of local and transport processes on phytoplankton biomass over a range of timescales from hourly to annually. For the Upper James River, results show that the relative importance of local and transport processes differs on different timescales. Local processes dominate phytoplankton variability on daily to weekly timescales, whereas the contribution of transport processes increases on seasonal to annual timescales and reaches equilibrium with local processes. With the use of the transport rate and high-frequency chlorophyll a data, a method similar to the open water oxygen method for metabolism is also presented to estimate phytoplankton primary production.

29 CFR 788.11 - “Transporting [such] products to the mill, processing plant, railroad, or other transportation...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false âTransporting [such] products to the mill, processing plant... EMPLOYED § 788.11 “Transporting [such] products to the mill, processing plant, railroad, or other transportation terminal.” The transportation or movement of logs or other forestry products to a “mill processing...

Different stages and status of vertical transporting process of Cu in Jiaozhou Bay

NASA Astrophysics Data System (ADS)

Yang, Dongfang; Li, Haixia; Wang, Qi; Zhang, Xiaolong; Ding, Jun

2017-12-01

Understanding the stages and status of vertical transporting process of pollutant in marine bay is essential to pollution control. This paper analyzed the stages and status of Cu’s vertical transporting process in waters in Jiaozhou Bay. Results showed that the vertical transporting process in waters in Jiaozhou Bay included four stages of 1) Cu was imported to the bay by major sources, 2) Cu was transported to surface waters, 3) Cu was transported from surface waters to sediment in sea bottom, and 4) Cu was fixed and buried in sediment. Furthermore, Cu’s vertical transporting process could be divided into seven status in detail, and he characteristics of the vertical transport process of Cu were also analyzed.

Novel fabrication technique of hybrid structure lens array for 3D images

NASA Astrophysics Data System (ADS)

Lee, Junsik; Kim, Junoh; Kim, Cheoljoong; Shin, Dooseub; Koo, Gyohyun; Won, Yong Hyub

2016-03-01

Tunable liquid lens arrays can produce three dimensional images by using electrowetting principle that alters surface tensions by applying voltage. This method has advantages of fast response time and low power consumption. However, it is challenging to fabricate a high fill factor liquid lens array and operate three dimensional images which demand high diopter. This study describes a hybrid structure lens array which has not only a liquid lens array but a solid lens array. A concave-shape lens array is unavoidable when using only the liquid lens array and some voltages are needed to make the lens flat. By placing the solid lens array on the liquid lens array, initial diopter can be positive. To fabricate the hybrid structure lens array, a conventional lithographic process in semiconductor manufacturing is needed. A negative photoresist SU-8 was used as chamber master molds. PDMS and UV adhesive replica molding are done sequentially. Two immiscible liquids, DI water and dodecane, are injected in the fabricated chamber, followed by sealing. The fabricated structure has a 20 by 20 pattern of cylindrical shaped circle array and the aperture size of each lens is 1mm. The thickness of the overall hybrid structure is about 2.8mm. Hybrid structure lens array has many advantages. Solid lens array has almost 100% fill factor and allow high efficiency. Diopter can be increased by more than 200 and negative diopter can be shifted to the positive region. This experiment showed several properties of the hybrid structure and demonstrated its superiority.

23 CFR 450.320 - Congestion management process in transportation management areas.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 23 Highways 1 2014-04-01 2014-04-01 false Congestion management process in transportation... Programming § 450.320 Congestion management process in transportation management areas. (a) The transportation planning process in a TMA shall address congestion management through a process that provides for safe and...

23 CFR 450.320 - Congestion management process in transportation management areas.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Congestion management process in transportation... Programming § 450.320 Congestion management process in transportation management areas. (a) The transportation planning process in a TMA shall address congestion management through a process that provides for safe and...

23 CFR 450.320 - Congestion management process in transportation management areas.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 23 Highways 1 2013-04-01 2013-04-01 false Congestion management process in transportation... Programming § 450.320 Congestion management process in transportation management areas. (a) The transportation planning process in a TMA shall address congestion management through a process that provides for safe and...

Application studies of RFID technology in the process of coal logistics transport

NASA Astrophysics Data System (ADS)

Qiao, Bingqin; Chang, Xiaoming; Hao, Meiyan; Kong, Dejin

2012-04-01

For quality control problems in coal transport, RFID technology has been proposed to be applied to coal transportation process. The whole process RFID traceability system from coal production to consumption has been designed and coal supply chain logistics tracking system integration platform has been built, to form the coal supply chain traceability and transport tracking system and providing more and more transparent tracking and monitoring of coal quality information for consumers of coal. Currently direct transport and combined transport are the main forms of coal transportation in China. The means of transport are cars, trains and ships. In the booming networking environment of RFID technology, the RFID technology will be applied to coal logistics and provide opportunity for the coal transportation tracking in the process transportation.

Interaction between electrically charged droplets in microgravity

NASA Astrophysics Data System (ADS)

Brandenbourger, Martin; Caps, Herve; Hardouin, Jerome; Vitry, Youen; Boigelot, Bernard; Dorbolo, Stephane; Grasp Team; Beams Collaboration

2015-11-01

The past ten years, electrically charged droplets have been studied tremendously for their applications in industry (electrospray, electrowetting,...). However, charged droplets are also present in nature. Indeed, it has been shown that the droplets falling from thunderclouds possess an excess of electric charges. Moreover, some research groups try to use the electrical interaction between drops in order to control the coalescence between cloud droplets and control rain generation. The common way to study this kind of system is to make hypothesis on the interaction between two charged drops. Then, these hypothesis are extended to a system of thousands of charged droplets. Thanks to microgravity conditions, we were able to study the interaction between two electrically charged droplets. In practice, the charged droplets were propelled one in front of the other at low speed (less than 1 m/s). The droplets trajectory is studied for various charges and volumes. The repulsion between two charged drops is correctly fitted by a simple Coulomb repulsion law. In the case of attractive interactions, we discuss the collisions observed as a function of the droplets speed, volume and electric charges. Thanks to FNRS for financial support.

49 CFR 40.73 - How is the collection process completed?

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 1 2013-10-01 2013-10-01 false How is the collection process completed? 40.73 Section 40.73 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Urine Specimen Collections § 40.73 How is the collection process...

49 CFR 40.73 - How is the collection process completed?

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false How is the collection process completed? 40.73 Section 40.73 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Urine Specimen Collections § 40.73 How is the collection process...

49 CFR 40.73 - How is the collection process completed?

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 1 2012-10-01 2012-10-01 false How is the collection process completed? 40.73 Section 40.73 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Urine Specimen Collections § 40.73 How is the collection process...

49 CFR 40.73 - How is the collection process completed?

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 1 2014-10-01 2014-10-01 false How is the collection process completed? 40.73 Section 40.73 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Urine Specimen Collections § 40.73 How is the collection process...

Transportation of part supply improvement in agricultural machinery assembly plant

NASA Astrophysics Data System (ADS)

Saysaman, Anusit; Chutima, Parames

2018-02-01

This research focused on the problem caused by the transportation of part supply in agricultural machinery assembly plant in Thailand, which is one of the processes that are critical to the whole production process. If poorly managed, it will affect transportation of part supply, the emergence of sink cost, quality problems, and the ability to respond to the needs of the customers in time. Since the competition in the agricultural machinery market is more intense, the efficiency of part transportation process has to be improved. In this study, the process of transporting parts of the plant was studied and it was found that the efficiency of the process of transporting parts from the sub assembly line to its main assembly line was 83%. The approach to the performance improvement is done by using the Lean tool to limit wastes based on the ECRS principle and applying pull production system by changing the transportation method to operate as milkrun for transportation of parts to synchronize with the part demands of the main assembly line. After the transportation of parts from sub-assembly line to the main assembly line was improved, the efficiency raised to 98% and transportation process cost was saved to 540,000 Baht per year.

Models of expert assessments and their study in problems of choice and decision-making in management of motor transport processes

NASA Astrophysics Data System (ADS)

Belokurov, V. P.; Belokurov, S. V.; Korablev, R. A.; Shtepa, A. A.

2018-05-01

The article deals with decision making concerning transport tasks on search iterations in the management of motor transport processes. An optimal selection of the best option for specific situations is suggested in the management of complex multi-criteria transport processes.

49 CFR Appendix A to Part 580 - Secure Printing Processes and Other Secure Processes

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Secure Printing Processes and Other Secure Processes A Appendix A to Part 580 Transportation Other Regulations Relating to Transportation (Continued... DISCLOSURE REQUIREMENTS Pt. 580, App. A Appendix A to Part 580—Secure Printing Processes and Other Secure...

49 CFR Appendix A to Part 580 - Secure Printing Processes and Other Secure Processes

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Secure Printing Processes and Other Secure Processes A Appendix A to Part 580 Transportation Other Regulations Relating to Transportation (Continued... DISCLOSURE REQUIREMENTS Pt. 580, App. A Appendix A to Part 580—Secure Printing Processes and Other Secure...

49 CFR Appendix A to Part 580 - Secure Printing Processes and Other Secure Processes

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Secure Printing Processes and Other Secure Processes A Appendix A to Part 580 Transportation Other Regulations Relating to Transportation (Continued... DISCLOSURE REQUIREMENTS Pt. 580, App. A Appendix A to Part 580—Secure Printing Processes and Other Secure...

49 CFR Appendix A to Part 580 - Secure Printing Processes and Other Secure Processes

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Secure Printing Processes and Other Secure Processes A Appendix A to Part 580 Transportation Other Regulations Relating to Transportation (Continued... DISCLOSURE REQUIREMENTS Pt. 580, App. A Appendix A to Part 580—Secure Printing Processes and Other Secure...

Campylobacter and Salmonella in broiler processing – transport through chill

USDA-ARS?s Scientific Manuscript database

When market age broilers are transported to processing plants, feces from individual birds in a Campylobacter positive flock can contaminate transport containers (1). Feces, and therefore Campylobacter, is deposited on the floor surface of transport cages. When placed in soiled transport cages pr...

A model of ion transport processes along and across the neuronal membrane.

PubMed

Xiang, Z X; Liu, G Z; Tang, C X; Yan, L X

2017-01-01

In this study, we provide a foundational model of ion transport processes in the intracellular and extracellular compartments of neurons at the nanoscale. There are two different kinds of ionic transport processes: (i) ionic transport across the neuronal membrane (trans-membrane), and (ii) ionic transport along both the intracellular and extracellular surfaces of the membrane. Brownian dynamics simulations are used to give a description of ionic trans-membrane transport. Electro-diffusion is used to model ion transport along the membrane surface, and the two transport processes can be linked analytically. In our model, we found that the interactions between ions and ion channels result in high-frequency ionic oscillations during trans-membrane transport. In ion transport along the membrane, high-frequency ionic oscillations may be evoked on both the intracellular and extracellular surfaces of the plasma membrane. The electric field caused by Coulomb interactions between the ions is found to be the most likely origin of those ionic oscillations.

The vesicle protein SAM-4 regulates the processivity of synaptic vesicle transport.

PubMed

Zheng, Qun; Ahlawat, Shikha; Schaefer, Anneliese; Mahoney, Tim; Koushika, Sandhya P; Nonet, Michael L

2014-10-01

Axonal transport of synaptic vesicles (SVs) is a KIF1A/UNC-104 mediated process critical for synapse development and maintenance yet little is known of how SV transport is regulated. Using C. elegans as an in vivo model, we identified SAM-4 as a novel conserved vesicular component regulating SV transport. Processivity, but not velocity, of SV transport was reduced in sam-4 mutants. sam-4 displayed strong genetic interactions with mutations in the cargo binding but not the motor domain of unc-104. Gain-of-function mutations in the unc-104 motor domain, identified in this study, suppress the sam-4 defects by increasing processivity of the SV transport. Genetic analyses suggest that SAM-4, SYD-2/liprin-α and the KIF1A/UNC-104 motor function in the same pathway to regulate SV transport. Our data support a model in which the SV protein SAM-4 regulates the processivity of SV transport.

The Vesicle Protein SAM-4 Regulates the Processivity of Synaptic Vesicle Transport

PubMed Central

Zheng, Qun; Ahlawat, Shikha; Schaefer, Anneliese; Mahoney, Tim; Koushika, Sandhya P.; Nonet, Michael L.

2014-01-01

Axonal transport of synaptic vesicles (SVs) is a KIF1A/UNC-104 mediated process critical for synapse development and maintenance yet little is known of how SV transport is regulated. Using C. elegans as an in vivo model, we identified SAM-4 as a novel conserved vesicular component regulating SV transport. Processivity, but not velocity, of SV transport was reduced in sam-4 mutants. sam-4 displayed strong genetic interactions with mutations in the cargo binding but not the motor domain of unc-104. Gain-of-function mutations in the unc-104 motor domain, identified in this study, suppress the sam-4 defects by increasing processivity of the SV transport. Genetic analyses suggest that SAM-4, SYD-2/liprin-α and the KIF1A/UNC-104 motor function in the same pathway to regulate SV transport. Our data support a model in which the SV protein SAM-4 regulates the processivity of SV transport. PMID:25329901

Field induced anomalous spreading, oscillation, ejection, spinning, and breaking of oil droplets on a strongly slipping water surface.

PubMed

Kumar, Sunny; Sarma, Bhaskarjyoti; Dasmahapatra, Ahsok Kumar; Dalal, Amaresh; Basu, Dipankar Narayan; Bandyopadhyay, Dipankar

2017-07-01

Application of an electric field on an oil droplet floating on the surface of a deionized water bath showed interesting motions such as spreading, oscillation, and ejection. The electric field was generated by connecting a pointed platinum cathode at the top of the oil droplet and a copper anode coated with polymer at the bottom of the water layer. The experimental setup mimicked a conventional electrowetting setup with the exception that the oil was spread on a soft and deformable water isolator. While at relatively lower field intensities we observed spreading of the droplet, at intermediate field intensities the droplet oscillated around the platinum cathode, before ejecting out at a speed as high as ∼5 body lengths per second at even stronger field intensities. The experiments suggested that when the electric field was ramped up abruptly to a particular voltage, any of the spreading, oscillation, or ejection motions of the droplet could be engendered at lower, intermediate and higher field intensities, respectively. However, when the field was ramped up progressively by increasing by a definite amount of voltage per unit time, all three aforementioned motions could be generated simultaneously with the increase in the field intensity. Interestingly, when the aforementioned setup was placed on a magnet, the droplet showed a rotational motion under the influence of the Lorentz force, which was generated because of the coupling of the weak leakage current with the externally applied magnetic field. The spreading, oscillation, ejection, and rotation of the droplet were found to be functions of the oil-water interfacial tension, viscosity, and size of the oil droplet. We developed simple theoretical models to explain the experimental results obtained. Importantly, rotating at a higher speed broke the droplet into a number of smaller ones, owing to the combined influence of the spreading due to the centripetal force and the shear at the oil-water interface. While the oscillatory and rotational motions of the incompressible droplet could be employed as stirrers or impellers inside microfluidic devices for mixing applications, the droplet ejection could be employed for futuristic applications such as payload transport or drug delivery.

49 CFR 397.209 - Preemption processing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS TRANSPORTATION OF HAZARDOUS MATERIALS; DRIVING AND PARKING RULES Preemption Procedures § 397.209 Preemption processing. (a) The...

49 CFR 397.217 - Waiver processing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS TRANSPORTATION OF HAZARDOUS MATERIALS; DRIVING AND PARKING RULES Preemption Procedures § 397.217 Waiver processing. (a) The...

Theories of transporting processes of Cu in Jiaozhou Bay

NASA Astrophysics Data System (ADS)

Yang, Dongfang; Su, Chunhua; Zhu, Sixi; Wu, Yunjie; Zhou, Wei

2018-02-01

Many marine bays have been polluted along with the rapid development of industry and population size, and understanding the transporting progresses of pollutants is essential to pollution control. In order to better understanding the transporting progresses of pollutants in marine, this paper carried on a comprehensive research of the theories of transporting processes of Cu in Jiaozhou Bay. Results showed that the transporting processes of Cu in this bay could be summarized into seven key theories including homogeneous theory, environmental dynamic theory, horizontal loss theory, source to waters transporting theory, sedimentation transporting theory, migration trend theory and vertical transporting theory, respectively. These theories helpful to better understand the migration progress of pollutants in marine bay.

49 CFR 624.5 - Application process.

Code of Federal Regulations, 2010 CFR

2010-10-01

... other public transportation entities or other related projects within the applicant's Metropolitan... 49 Transportation 7 2010-10-01 2010-10-01 false Application process. 624.5 Section 624.5 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION...

Role of Passive Diffusion, Transporters, and Membrane Trafficking-Mediated Processes in Cellular Drug Transport.

PubMed

Cocucci, E; Kim, J Y; Bai, Y; Pabla, N

2017-01-01

Intracellular drug accumulation is thought to be dictated by two major processes, passive diffusion through the lipid membrane or membrane transporters. The relative role played by these distinct processes remains actively debated. Moreover, the role of membrane-trafficking in drug transport remains underappreciated and unexplored. Here we discuss the distinct processes involved in cellular drug distribution and propose that better experimental models are required to elucidate the differential contributions of various processes in intracellular drug accumulation. © 2016 American Society for Clinical Pharmacology and Therapeutics.

49 CFR 601.46 - Processing of petitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Processing of petitions. 601.46 Section 601.46 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ORGANIZATION, FUNCTIONS, AND PROCEDURES Emergency Procedures for Public...

Use of GIS technologies to facilitate the transportation project programming process.

DOT National Transportation Integrated Search

2008-05-01

Transportation project programming in a transportation agency is a process of matching : potential projects with available funds to accomplish the agencys mission and goals of a : given period of time. Result of this process is normally a transpor...

Interactions of solutes and streambed sediment: 2. A dynamic analysis of coupled hydrologic and chemical processes that determine solute transport

USGS Publications Warehouse

Bencala, Kenneth E.

1984-01-01

Solute transport in streams is determined by the interaction of physical and chemical processes. Data from an injection experiment for chloride and several cations indicate significant influence of solutestreambed processes on transport in a mountain stream. These data are interpreted in terms of transient storage processes for all tracers and sorption processes for the cations. Process parameter values are estimated with simulations based on coupled quasi-two-dimensional transport and first-order mass transfer sorption. Comparative simulations demonstrate the relative roles of the physical and chemical processes in determining solute transport. During the first 24 hours of the experiment, chloride concentrations were attenuated relative to expected plateau levels. Additional attenuation occurred for the sorbing cation strontium. The simulations account for these storage processes. Parameter values determined by calibration compare favorably with estimates from other studies in mountain streams. Without further calibration, the transport of potassium and lithium is adequately simulated using parameters determined in the chloride-strontium simulation and with measured cation distribution coefficients.

Analysis and classification of bedload transport events with variable process characteristics

NASA Astrophysics Data System (ADS)

Kreisler, Andrea; Moser, Markus; Aigner, Johann; Rindler, Rolf; Tritthart, Michael; Habersack, Helmut

2017-08-01

Knowledge about the magnitude of bedload fluxes at given hydraulic conditions in natural streams is essential for improved process understanding, for the application, calibration and validation of bedload transport formulas, and for numerical sediment transport models. Nonetheless, extensive field measurements of bedload transport are challenging and therefore data from such efforts are rare. Bedload transport has been measured comprehensively at the downstream section of the Urslau torrent in Salzburg, Austria, since 2011. We used an integrative monitoring system that combines direct (mobile basket sampler, slot sampler) and indirect measuring devices (geophone plates). Continuous information about the intensity and distribution of bedload transport within the channel cross-section is available in high spatial and temporal resolution. Seven geophone plates at a stream width of 8 m are part of a measurement system that delivers data in 1-min intervals. These geophone data are calibrated using results of direct bedload measurements, providing an opportunity to calculate bedload rates and bedload yields in selected time periods. Continuous data on the bedload transport process over three years enabled assessing several bedload transport events. The investigation of bedload transport rate/discharge relationships reveals order-of-magnitude changes. For individual events, we observed shifts in the data, reflecting different bedload rates at comparable hydraulic conditions. This study reveals that variable sediment supply conditions affect the prevailing bedload transport rates at the Urslau stream. Calculating the bedload transport efficiency enables comparing bedload transport events that exhibit similar process characteristics. Finally, we provide a conceptual model of bedload transport process types as a function of bedload transport efficiency and dimensionless stream power.

Surface transport processes in charged porous media

DOE PAGES

Gabitto, Jorge; Tsouris, Costas

2017-03-03

Surface transport processes are important in chemistry, colloidal sciences, engineering, biology, and geophysics. Natural or externally produced charges on surfaces create electrical double layers (EDLs) at the solid-liquid interface. The existence of the EDLs produces several complex processes including bulk and surface transport of ions. In this work, a model is presented to simulate bulk and transport processes in homogeneous porous media comprising big pores. It is based on a theory for capacitive charging by ideally polarizable porous electrodes without Faradaic reactions or specific adsorption of ions. A volume averaging technique is used to derive the averaged transport equations inmore » the limit of thin electrical double layers. Description of the EDL between the electrolyte solution and the charged wall is accomplished using the Gouy-Chapman-Stern (GCS) model. The surface transport terms enter into the average equations due to the use of boundary conditions for diffuse interfaces. Two extra surface transports terms appear in the closed average equations. One is a surface diffusion term equivalent to the transport process in non-charged porous media. The second surface transport term is a migration term unique to charged porous media. The effective bulk and transport parameters for isotropic porous media are calculated solving the corresponding closure problems.« less

Surface transport processes in charged porous media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gabitto, Jorge; Tsouris, Costas

Surface transport processes are important in chemistry, colloidal sciences, engineering, biology, and geophysics. Natural or externally produced charges on surfaces create electrical double layers (EDLs) at the solid-liquid interface. The existence of the EDLs produces several complex processes including bulk and surface transport of ions. In this work, a model is presented to simulate bulk and transport processes in homogeneous porous media comprising big pores. It is based on a theory for capacitive charging by ideally polarizable porous electrodes without Faradaic reactions or specific adsorption of ions. A volume averaging technique is used to derive the averaged transport equations inmore » the limit of thin electrical double layers. Description of the EDL between the electrolyte solution and the charged wall is accomplished using the Gouy-Chapman-Stern (GCS) model. The surface transport terms enter into the average equations due to the use of boundary conditions for diffuse interfaces. Two extra surface transports terms appear in the closed average equations. One is a surface diffusion term equivalent to the transport process in non-charged porous media. The second surface transport term is a migration term unique to charged porous media. The effective bulk and transport parameters for isotropic porous media are calculated solving the corresponding closure problems.« less

Transport induced by mean-eddy interaction: II. Analysis of transport processes

NASA Astrophysics Data System (ADS)

Ide, Kayo; Wiggins, Stephen

2015-03-01

We present a framework for the analysis of transport processes resulting from the mean-eddy interaction in a flow. The framework is based on the Transport Induced by the Mean-Eddy Interaction (TIME) method presented in a companion paper (Ide and Wiggins, 2014) [1]. The TIME method estimates the (Lagrangian) transport across stationary (Eulerian) boundaries defined by chosen streamlines of the mean flow. Our framework proceeds after first carrying out a sequence of preparatory steps that link the flow dynamics to the transport processes. This includes the construction of the so-called "instantaneous flux" as the Hovmöller diagram. Transport processes are studied by linking the signals of the instantaneous flux field to the dynamical variability of the flow. This linkage also reveals how the variability of the flow contributes to the transport. The spatio-temporal analysis of the flux diagram can be used to assess the efficiency of the variability in transport processes. We apply the method to the double-gyre ocean circulation model in the situation where the Rossby-wave mode dominates the dynamic variability. The spatio-temporal analysis shows that the inter-gyre transport is controlled by the circulating eddy vortices in the fast eastward jet region, whereas the basin-scale Rossby waves have very little impact.

NaturAnalogs for the Unsaturated Zone

DOE Office of Scientific and Technical Information (OSTI.GOV)

A. Simmons; A. Unger; M. Murrell

2000-03-08

The purpose of this Analysis/Model Report (AMR) is to document natural and anthropogenic (human-induced) analog sites and processes that are applicable to flow and transport processes expected to occur at the potential Yucca Mountain repository in order to build increased confidence in modeling processes of Unsaturated Zone (UZ) flow and transport. This AMR was prepared in accordance with ''AMR Development Plan for U0135, Natural Analogs for the UZ'' (CRWMS 1999a). Knowledge from analog sites and processes is used as corroborating information to test and build confidence in flow and transport models of Yucca Mountain, Nevada. This AMR supports the Unsaturatedmore » Zone (UZ) Flow and Transport Process Model Report (PMR) and the Yucca Mountain Site Description. The objectives of this AMR are to test and build confidence in the representation of UZ processes in numerical models utilized in the UZ Flow and Transport Model. This is accomplished by: (1) applying data from Boxy Canyon, Idaho in simulations of UZ flow using the same methodologies incorporated in the Yucca Mountain UZ Flow and Transport Model to assess the fracture-matrix interaction conceptual model; (2) Providing a preliminary basis for analysis of radionuclide transport at Pena Blanca, Mexico as an analog of radionuclide transport at Yucca Mountain; and (3) Synthesizing existing information from natural analog studies to provide corroborating evidence for representation of ambient and thermally coupled UZ flow and transport processes in the UZ Model.« less

49 CFR 389.33 - Processing of petition.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 5 2010-10-01 2010-10-01 false Processing of petition. 389.33 Section 389.33 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY...-FEDERAL MOTOR CARRIER SAFETY REGULATIONS Procedures for Adoption of Rules § 389.33 Processing of petition...

49 CFR 389.33 - Processing of petition.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 5 2011-10-01 2011-10-01 false Processing of petition. 389.33 Section 389.33 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY...-FEDERAL MOTOR CARRIER SAFETY REGULATIONS Procedures for Adoption of Rules § 389.33 Processing of petition...

Localization of the Calcium Regulated Citrate Transport Process in Proximal Tubule Cells

PubMed Central

Hering-Smith, Kathleen S.; Mao, Weibo; Schiro, Faith R.; Coleman-Barnett, Joycelynn; Pajor, Ana M.; Hamm, L. Lee

2014-01-01

Urinary citrate is an important inhibitor of calcium stone formation. Most of citrate reabsorption in the proximal tubule is thought to occur via a dicarboxylate transporter NaDC1 located in the apical membrane. OK cells, an established opossum kidney proximal tubule cell line, transport citrate but the characteristics change with extracellular calcium such that low calcium solutions stimulate total citrate transport as well as increase the apparent affinity for transport. The present studies address several fundamental properties of this novel process: the polarity of the transport process, the location of the calcium-sensitivity and whether NaDC1 is present in OK cells. OK cells grown on permeable supports exhibited apical > basolateral citrate transport. Apical transport of both citrate and succinate was sensitive to extracellular calcium whereas basolateral transport was not. Apical calcium, rather than basolateral, was the predominant determinant of changes in transport. Also 2,3-dimethylsuccinate, previously identified as an inhibitor of basolateral dicarboxylate transport, inhibited apical citrate uptake. Although the calcium-sensitive transport process in OK cells is functionally not typical NaDC1, NaDC1 is present in OK cells by Western blot and PCR. By immunolocalization studies, NaDC1 was predominantly located in discrete apical membrane or subapical areas. However by biotinylation, apical NaDC1 decreases in the apical membrane with lowering calcium. In sum, OK cells express a calcium-sensitive/regulated dicarboxylate process at the apical membrane which responds to variations in apical calcium. Despite the functional differences of this process compared to NaDC1, NaDC1 is present in these cells, but predominantly in subapical vesicles. PMID:24652587

Determination of thermodynamic and transport parameters of naphthenic acids and organic process chemicals in oil sand tailings pond water.

PubMed

Wang, Xiaomeng; Robinson, Lisa; Wen, Qing; Kasperski, Kim L

2013-07-01

Oil sand tailings pond water contains naphthenic acids and process chemicals (e.g., alkyl sulphates, quaternary ammonium compounds, and alkylphenol ethoxylates). These chemicals are toxic and can seep through the foundation of the tailings pond to the subsurface, potentially affecting the quality of groundwater. As a result, it is important to measure the thermodynamic and transport parameters of these chemicals in order to study the transport behavior of contaminants through the foundation as well as underground. In this study, batch adsorption studies and column experiments were performed. It was found that the transport parameters of these chemicals are related to their molecular structures and other properties. The computer program (CXTFIT) was used to further evaluate the transport process in the column experiments. The results from this study show that the transport of naphthenic acids in a glass column is an equilibrium process while the transport of process chemicals seems to be a non-equilibrium process. At the end of this paper we present a real-world case study in which the transport of the contaminants through the foundation of an external tailings pond is calculated using the lab-measured data. The results show that long-term groundwater monitoring of contaminant transport at the oil sand mining site may be necessary to avoid chemicals from reaching any nearby receptors.

49 CFR 520.24 - Internal processing of draft environmental impact statements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 6 2014-10-01 2014-10-01 false Internal processing of draft environmental impact statements. 520.24 Section 520.24 Transportation Other Regulations Relating to Transportation (Continued... ENVIRONMENTAL IMPACTS Procedures § 520.24 Internal processing of draft environmental impact statements. Before...

49 CFR 520.24 - Internal processing of draft environmental impact statements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 6 2011-10-01 2011-10-01 false Internal processing of draft environmental impact statements. 520.24 Section 520.24 Transportation Other Regulations Relating to Transportation (Continued... ENVIRONMENTAL IMPACTS Procedures § 520.24 Internal processing of draft environmental impact statements. Before...

49 CFR 520.24 - Internal processing of draft environmental impact statements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 6 2012-10-01 2012-10-01 false Internal processing of draft environmental impact statements. 520.24 Section 520.24 Transportation Other Regulations Relating to Transportation (Continued... ENVIRONMENTAL IMPACTS Procedures § 520.24 Internal processing of draft environmental impact statements. Before...

49 CFR 520.24 - Internal processing of draft environmental impact statements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 6 2013-10-01 2013-10-01 false Internal processing of draft environmental impact statements. 520.24 Section 520.24 Transportation Other Regulations Relating to Transportation (Continued... ENVIRONMENTAL IMPACTS Procedures § 520.24 Internal processing of draft environmental impact statements. Before...

23 CFR 450.206 - Scope of the statewide transportation planning process.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 23 Highways 1 2012-04-01 2012-04-01 false Scope of the statewide transportation planning process. 450.206 Section 450.206 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PLANNING AND RESEARCH PLANNING ASSISTANCE AND STANDARDS Statewide Transportation Planning and Programming § 450...

23 CFR 450.206 - Scope of the statewide transportation planning process.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 23 Highways 1 2014-04-01 2014-04-01 false Scope of the statewide transportation planning process. 450.206 Section 450.206 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PLANNING AND RESEARCH PLANNING ASSISTANCE AND STANDARDS Statewide Transportation Planning and Programming § 450...

23 CFR 450.206 - Scope of the statewide transportation planning process.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 23 Highways 1 2013-04-01 2013-04-01 false Scope of the statewide transportation planning process. 450.206 Section 450.206 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PLANNING AND RESEARCH PLANNING ASSISTANCE AND STANDARDS Statewide Transportation Planning and Programming § 450...

23 CFR 450.206 - Scope of the statewide transportation planning process.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Scope of the statewide transportation planning process. 450.206 Section 450.206 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PLANNING AND RESEARCH PLANNING ASSISTANCE AND STANDARDS Statewide Transportation Planning and Programming § 450...

23 CFR 450.206 - Scope of the statewide transportation planning process.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Scope of the statewide transportation planning process. 450.206 Section 450.206 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PLANNING AND RESEARCH PLANNING ASSISTANCE AND STANDARDS Statewide Transportation Planning and Programming § 450...

49 CFR 510.12 - Remedies for failure to comply with compulsory process.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Remedies for failure to comply with compulsory process. 510.12 Section 510.12 Transportation Other Regulations Relating to Transportation (Continued... § 510.12 Remedies for failure to comply with compulsory process. Any failure to comply with compulsory...

49 CFR 40.305 - How does the return-to-duty process conclude?

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 1 2011-10-01 2011-10-01 false How does the return-to-duty process conclude? 40.305 Section 40.305 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Substance Abuse Professionals and the Return-to-Duty...

49 CFR 40.305 - How does the return-to-duty process conclude?

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 1 2012-10-01 2012-10-01 false How does the return-to-duty process conclude? 40.305 Section 40.305 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Substance Abuse Professionals and the Return-to-Duty...

49 CFR 40.305 - How does the return-to-duty process conclude?

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 1 2013-10-01 2013-10-01 false How does the return-to-duty process conclude? 40.305 Section 40.305 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Substance Abuse Professionals and the Return-to-Duty...

49 CFR 40.305 - How does the return-to-duty process conclude?

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false How does the return-to-duty process conclude? 40.305 Section 40.305 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Substance Abuse Professionals and the Return-to-Duty...

49 CFR 40.305 - How does the return-to-duty process conclude?

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 1 2014-10-01 2014-10-01 false How does the return-to-duty process conclude? 40.305 Section 40.305 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Substance Abuse Professionals and the Return-to-Duty...

Identification of significant transport processes for organic micropollutant classes during soil aquifer treatment (SAT) - a controlled field experiment

NASA Astrophysics Data System (ADS)

Nödler, Karsten; Licha, Tobias; Sauter, Martin

2010-05-01

Supplementing existing water resources with alternative sources of water is a challenge in semi-arid areas, as deterioration of water quality must be avoided. Soil aquifer treatment (SAT) can greatly improve the quality of the injected water by attenuation of organic pollutants via sorption and degradation processes. However, only little is known about the specific transport processes of organic micropollutants under artificial recharge conditions. Organic micropollutants such as pharmaceuticals and their metabolites exhibit a wide range of chemical properties and may undergo very different environmental processes resulting in specific reactions within specified environments. In the presented study fate and transport processes of 25 organic micropollutants (iodinated contrast media, antihypertensive agents, antibiotics, anticonvulsants, lipid regulators, anti-inflammatories, antihistamines and analgesics) were investigated under SAT conditions in a controlled field experiment. Secondary treated effluent (STE) containing the compounds of interest was introduced into the aquifer by an infiltration pond and shallow wells in the vicinity were used for water quality monitoring. By means of strategic sampling procedure and a specialized multi-residue analytical method based on high-performance liquid chromatography / tandem mass spectrometry (LC/MS-MS) 3 main transport processes were identified: 1. Transport of non-polar compounds according to their respective octanol-water distribution coefficient (Kow) 2. Cation exchange 3. Colloidal transport Identification of transport processes 2 & 3 was not expected to act as a transport controlling process. Results of the positively charged beta-blockers sotalol, atenolol and metoprolol gave clear evidence for cation exchange processes of the compounds with the aquifer material. Correlation of turbidity and concentrations of macrolide antibiotics (clarithromycin, erythromycin and roxithromycin) demonstrated the colloidal transport of the respective compounds. Concentrations of almost all micropollutants decreased with increasing soil passage. However, since compounds transported by processes 2 & 3 can be re-mobilized by changing water chemistry, the importance of a diligent characterisation of aquifer material and raw water is apparent for risk assessment. The experiments were conducted within the context of the project GABARDINE, funded by the European Commission.

Integrated urban systems model with multiple transportation supply agents.

DOT National Transportation Integrated Search

2012-10-01

This project demonstrates the feasibility of developing quantitative models that can forecast future networks under : current and alternative transportation planning processes. The current transportation planning process is modeled : based on empiric...

Solution processed metal oxide thin film hole transport layers for high performance organic solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steirer, K. Xerxes; Berry, Joseph J.; Chesin, Jordan P.

2017-01-10

A method for the application of solution processed metal oxide hole transport layers in organic photovoltaic devices and related organic electronics devices is disclosed. The metal oxide may be derived from a metal-organic precursor enabling solution processing of an amorphous, p-type metal oxide. An organic photovoltaic device having solution processed, metal oxide, thin-film hole transport layer.

Transport processes of the legume symbiosome membrane

PubMed Central

Clarke, Victoria C.; Loughlin, Patrick C.; Day, David A.; Smith, Penelope M. C.

2014-01-01

The symbiosome membrane (SM) is a physical barrier between the host plant and nitrogen-fixing bacteria in the legume:rhizobia symbiosis, and represents a regulated interface for the movement of solutes between the symbionts that is under plant control. The primary nutrient exchange across the SM is the transport of a carbon energy source from plant to bacteroid in exchange for fixed nitrogen. At a biochemical level two channels have been implicated in movement of fixed nitrogen across the SM and a uniporter that transports monovalent dicarboxylate ions has been characterized that would transport fixed carbon. The aquaporin NOD26 may provide a channel for ammonia, but the genes encoding the other transporters have not been identified. Transport of several other solutes, including calcium and potassium, have been demonstrated in isolated symbiosomes, and genes encoding transport systems for the movement of iron, nitrate, sulfate, and zinc in nodules have been identified. However, definitively matching transport activities with these genes has proved difficult and many further transport processes are expected on the SM to facilitate the movement of nutrients between the symbionts. Recently, work detailing the SM proteome in soybean has been completed, contributing significantly to the database of known SM proteins. This represents a valuable resource for the identification of transporter protein candidates, some of which may correspond to transport processes previously described, or to novel transport systems in the symbiosis. Putative transporters identified from the proteome include homologs of transporters of sulfate, calcium, peptides, and various metal ions. Here we review current knowledge of transport processes of the SM and discuss the requirements for additional transport routes of other nutrients exchanged in the symbiosis, with a focus on transport systems identified through the soybean SM proteome. PMID:25566274

A simulation of dielectrophoresis force actuated liquid lens

NASA Astrophysics Data System (ADS)

Yao, Xiaoyin; Xia, Jun

2009-11-01

Dielectrophoresis (DEP) and electrowetting on dielectric (EWOD) are based on the electrokinetic mechanisms which have great potential in microfluidic manipulation. DEP dominate the movement of particles induced by polarization effects in nonuniform electric field ,while EWOD has become one of the most widely used tools for manipulating tiny amounts of liquids on solid surfaces. Liquid lens driven by EWOD have been well studied and developed. But liquid lens driven by DEP has not been studied adequately. This paper focuses on modeling liquid lens driven by DEP force. A simulation of DEP driven droplet dynamics was performed by coupling of the electrostatic field and the two-phase flow field. Two incompressible and dielectric liquids with different permittivity were chosen in the two-phase flow field. The DEP force density, in direct proportion to gradient of the square of the electric field intensity, was used as a body force density in Navier-Stokes equation. When voltage applied, the liquid with high permittivity flowed to the place where the gradient of the square of the electric field intensity was higher, and thus change the curvature of interface between two immiscible liquid. The differences between DEP and EWOD liquid lens were also presented.

Numerical simulation for meniscus shape and optical performance of a MEMS-based liquid micro-lens.

PubMed

Lee, Shong-Leih; Yang, Chao-Fu

2008-11-24

It is very difficult to fabricate tunable optical systems having an aperture below 1000 micrometers with the conventional means on macroscopic scale. Krogmann et al. (J. Opt. A 8, S330-S336, 2006) presented a MEMS-based tunable liquid micro-lens system with an aperture of 300 micrometers. The system exhibited a tuning range of back focal length between 2.3mm and infinity by using the electrowetting effect to change the contact angle of the meniscus shape on silicon with a voltage of 0-45 V. However, spherical aberration was found in their lens system. In the present study, a numerical simulation is performed for this same physical configuration by solving the Young-Laplace equation on the interface of the lens liquid and the surrounding liquid. The resulting meniscus shape produces a back focal length that agrees with the experimental observation excellently. To eliminate the spherical aberration, an electric field is applied on the lens. The electric field alters the Young-Laplace equation and thus changes the meniscus shape and the lens quality. The numerical result shows that the spherical aberration of the lens can be essentially eliminated when a proper electric field is applied.

Varifocal liquid lens based on microelectrofluidic technology.

PubMed

Chang, Jong-hyeon; Jung, Kyu-Dong; Lee, Eunsung; Choi, Minseog; Lee, Seungwan; Kim, Woonbae

2012-11-01

This Letter presents a tunable liquid lens based on microelectrofluidic technology. In the microelectrofluidic lens (MEFL), electrowetting in the hydrophobic surface channel induces the Laplace pressure difference between two fluidic interfaces on the lens aperture and the surface channel. Then, the pressure difference makes the lens curvature tunable. In spite of the contact angle saturation, the narrow surface channel increases the Laplace pressure to have a wide range of optical power variation in the MEFL. The magnitude of the applied voltage determines the lens curvature in the analog mode MEFL. Digital operation is also possible when the control electrodes of the MEFL are patterned to have an array. The lens aperture and maximum surface channel diameter were designed to 3.2 mm and 6.4 mm, respectively, with a channel height of 0.2 mm for an optical power range between +210 and -30 D. By switching the control electrodes, the averaged transit time in steps and turnaround time were as low as 2.4 ms and 16.5 ms, respectively, in good agreement with the simulation results. It is expected that the proposed MEFL may be widely used with advantages of wide variation of the optical power with fast and precise controllability in a digital manner.

Numerical Simulation of Liquid Metal RF MEMS Switch Based on EWOD

NASA Astrophysics Data System (ADS)

Liu, Tingting; Gao, Yang; Yang, Tao; Guo, Huihui

2018-03-01

Conventional RF MEMS switches rely on metal-to-dielectric or metal-to-metal contacts. Some problems in the “solid-solid” contact, such as contact degradation, signal bounce and poor reliability, can be solved by using “liquid-solid” contact. The RF MEMS switch based on liquid metal is characterized by small contact resistance, no moving parts, high reliability and long life. Using electrowetting-on-dielectric (EWOD) way to control the movement of liquid metal in the RF MEMS switch, to achieve the “on” and “off” of the switch. In this paper, the electrical characteristics and RF characteristics of RF MEMS switches are simulated by fluid mechanics software FLUENT and electromagnetic simulation software HFSS. The effects of driving voltage, switching time, dielectric layer, hydrophobic layer material and thickness, switching channel height on the RF characteristics are studied. The results show that to increase the external voltage to the threshold voltage of 58V, the liquid metal began to move, and the switching time from “off” state to “on” state is 16ms. In the 0~20GHz frequency range, the switch insertion loss is less than 0.28dB, isolation is better than 23.32dB.

Technologies for autonomous integrated lab-on-chip systems for space missions

NASA Astrophysics Data System (ADS)

Nascetti, A.; Caputo, D.; Scipinotti, R.; de Cesare, G.

2016-11-01

Lab-on-chip devices are ideal candidates for use in space missions where experiment automation, system compactness, limited weight and low sample and reagent consumption are required. Currently, however, most microfluidic systems require external desktop instrumentation to operate and interrogate the chip, thus strongly limiting their use as stand-alone systems. In order to overcome the above-mentioned limitations our research group is currently working on the design and fabrication of "true" lab-on-chip systems that integrate in a single device all the analytical steps from the sample preparation to the detection without the need for bulky external components such as pumps, syringes, radiation sources or optical detection systems. Three critical points can be identified to achieve 'true' lab-on-chip devices: sample handling, analytical detection and signal transduction. For each critical point, feasible solutions are presented and evaluated. Proposed microfluidic actuation and control is based on electrowetting on dielectrics, autonomous capillary networks and active valves. Analytical detection based on highly specific chemiluminescent reactions is used to avoid external radiation sources. Finally, the integration on the same chip of thin film sensors based on hydrogenated amorphous silicon is discussed showing practical results achieved in different sensing tasks.

ALL-ELECTRONIC DROPLET GENERATION ON-CHIP WITH REAL-TIME FEEDBACK CONTROL FOR EWOD DIGITIAL MICROFLUIDICS

PubMed Central

Gong, Jian; Kim, Chang-Jin “CJ”

2009-01-01

Electrowetting-on-dielectric (EWOD) actuation enables digital (or droplet) microfluidics where small packets of liquids are manipulated on a two-dimensional surface. Due to its mechanical simplicity and low energy consumption, EWOD holds particular promise for portable systems. To improve volume precision of the droplets, which is desired for quantitative applications such as biochemical assays, existing practices would require near-perfect device fabricaion and operation conditions unless the droplets are generated under feedback control by an extra pump setup off of the chip. In this paper, we develop an all-electronic (i.e., no ancillary pumping) real-time feedback control of on-chip droplet generation. A fast voltage modulation, capacitance sensing, and discrete-time PID feedback controller are integrated on the operating electronic board. A significant improvement is obtained in the droplet volume uniformity, compared with an open loop control as well as the previous feedback control employing an external pump. Furthermore, this new capability empowers users to prescribe the droplet volume even below the previously considered minimum, allowing, for example, 1:x (x < 1) mixing, in comparison to the previously considered n:m mixing (i.e., n and m unit droplets). PMID:18497909

All-electronic droplet generation on-chip with real-time feedback control for EWOD digital microfluidics.

PubMed

Gong, Jian; Kim, Chang-Jin C J

2008-06-01

Electrowetting-on-dielectric (EWOD) actuation enables digital (or droplet) microfluidics where small packets of liquids are manipulated on a two-dimensional surface. Due to its mechanical simplicity and low energy consumption, EWOD holds particular promise for portable systems. To improve volume precision of the droplets, which is desired for quantitative applications such as biochemical assays, existing practices would require near-perfect device fabrication and operation conditions unless the droplets are generated under feedback control by an extra pump setup off of the chip. In this paper, we develop an all-electronic (i.e., no ancillary pumping) real-time feedback control of on-chip droplet generation. A fast voltage modulation, capacitance sensing, and discrete-time PID feedback controller are integrated on the operating electronic board. A significant improvement is obtained in the droplet volume uniformity, compared with an open loop control as well as the previous feedback control employing an external pump. Furthermore, this new capability empowers users to prescribe the droplet volume even below the previously considered minimum, allowing, for example, 1 : x (x < 1) mixing, in comparison to the previously considered n : m mixing (i.e., n and m unit droplets).

Electrowetting-actuated optical switch based on total internal reflection.

PubMed

Liu, Chao; Wang, Di; Yao, Li-Xiao; Li, Lei; Wang, Qiong-Hua

2015-04-01

In this paper we demonstrate a liquid optical switch based on total internal reflection. Two indium tin oxide electrodes are fabricated on the bottom substrate. A conductive liquid (Liquid 1) is placed on one side of the chamber and surrounded by a density-matched silicone oil (Liquid 2). In initial state, when the light beam illuminates the interface of the two liquids, it just meets the conditions of total internal reflection. The light is totally reflected by Liquid 2, and the device shows light-off state. When we apply a voltage to the other side of the indium tin oxide electrode, Liquid 1 stretched towards this side of the substrate and the curvature of the liquid-liquid interface changes. The light beam is refracted by Liquid 1 and the device shows light-on state. So the device can achieve the functions of an optical switch. Because the light beam can be totally reflected by the liquid, the device can attain 100% light intensity attenuation. Our experiments show that the response time from light-on (off) to light-off (on) are 130 and 132 ms, respectively. The proposed optical switch has potential applications in variable optical attenuators, information displays, and light shutters.

Strategies for Processing Semen from Subfertile Stallions for Cooled Transport.

PubMed

Varner, Dickson D

2016-12-01

Subfertility can be a confusing term because some semen of good quality can have reduced fertility following cooled transport if the semen is processed in an improper manner. General procedures aimed at processing stallion semen for cooled transport are well described. An array of factors could exist in reduced fertility of cool-transported semen. This article focuses on centrifugation techniques that can be used to maximize sperm quality of stallions whose semen is intended for cooled transport. Clinical cases are also provided for practical application of techniques. Copyright © 2016 Elsevier Inc. All rights reserved.

A COMSOL-GEMS interface for modeling coupled reactive-transport geochemical processes

NASA Astrophysics Data System (ADS)

Azad, Vahid Jafari; Li, Chang; Verba, Circe; Ideker, Jason H.; Isgor, O. Burkan

2016-07-01

An interface was developed between COMSOL MultiphysicsTM finite element analysis software and (geo)chemical modeling platform, GEMS, for the reactive-transport modeling of (geo)chemical processes in variably saturated porous media. The two standalone software packages are managed from the interface that uses a non-iterative operator splitting technique to couple the transport (COMSOL) and reaction (GEMS) processes. The interface allows modeling media with complex chemistry (e.g. cement) using GEMS thermodynamic database formats. Benchmark comparisons show that the developed interface can be used to predict a variety of reactive-transport processes accurately. The full functionality of the interface was demonstrated to model transport processes, governed by extended Nernst-Plank equation, in Class H Portland cement samples in high pressure and temperature autoclaves simulating systems that are used to store captured carbon dioxide (CO2) in geological reservoirs.

The Study on the Optimization of Container Multimodal Transport Business Process in Shandong

NASA Astrophysics Data System (ADS)

Wang, Fengmei; Gong, Xiaoyi; Ni, Yingying; Zhan, Jun; Che, Huiping

2018-06-01

Shandong is a coastal city with good location advantages. As a hub port for international trade goods and a port of transhipment, shandong's demand for multimodal transport is more urgent. By selecting the suitable non-water port and the multimodal transport carrier to improve the efficiency of multimodal transport, the purpose of saving the time of logistics is achieved, thus reducing the logistics cost.It branch out through Shandongt, and it can reach the central region of China, can reach the Western remote area ,too. This paper puts forward the optimization scheme of the business process of container multimodal transport. The optimization of freight forwarding business process is analyzed. The multimodal transport model in Shandong was designed. Finally, the optimal approach of multimodal transport in Shandong is put forward.

PLANiTS : structuring and supporting the intelligent transportation systems planning process

DOT National Transportation Integrated Search

1997-01-01

PLANiTS (Planning and Analysis Integration for Intelligent Transportation Systems) is a process-based computer system that supports a series of mutually interdependent steps progressing toward developing and programming transportation improvement pro...

The California general plan process and sustainable transportation planning

DOT National Transportation Integrated Search

2002-05-01

This research project assesses California's General Plan process as a tool for implementing sustainable development, with particular emphasis on transportation systems at the local level, including the relationship of local transportation systems to ...

Environmental impact assessment in urban transport planning: Exploring process-related barriers in Spanish practice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soria-Lara, Julio A., E-mail: j.a.sorialara@uva.nl; Bertolini, Luca, E-mail: l.bertolini@uva.nl; Brömmelstroet, Marco te, E-mail: M.C.G.teBrommelstroet@uva.nl

The effectiveness of EIA for evaluating transport planning projects is increasingly being questioned by practitioners, institutions and scholars. The academic literature has traditionally focused more on solving content-related problems with EIA (i.e. the measurement of environmental effects) than on process-related issues (i.e. the role of EIA in the planning process and the interaction between key actors). Focusing only on technical improvements is not sufficient for rectifying the effectiveness problems of EIA. In order to address this knowledge gap, the paper explores how EIA is experienced in the Spanish planning context and offers in-depth insight into EIA process-related issues in themore » field of urban transport planning. From the multitude of involved actors, the research focuses on exploring the perceptions of the two main professional groups: EIA developers and transport planners. Through a web-based survey we assess the importance of process-related barriers to the effective use of EIA in urban transport planning. The analyses revealed process issues based fundamentally on unstructured stakeholders involvement and an inefficient public participation - Highlights: • Qualitative research on perceptions of EIA participants on EIA processes. • Web-based survey with different participants (EIA-developers; transport planners). • It was seen an inefficient participation of stakeholders during the EIA processes.« less

Coupled transport, mixing and biogeochemical reactions in fractured media: experimental observations and modelling at the Ploemeur fractured rock observatory

NASA Astrophysics Data System (ADS)

Le Borgne, T.; Bochet, O.; Klepikova, M.; Kang, P. K.; Shakas, A.; Aquilina, L.; Dufresne, A.; Linde, N.; Dentz, M.; Bour, O.

2016-12-01

Transport processes in fractured media and associated reactions are governed by multiscale heterogeneity ranging from fracture wall roughness at small scale to broadly distributed fracture lengths at network scale. This strong disorder induces a variety of emerging phenomena, including flow channeling, anomalous transport and heat transfer, enhanced mixing and reactive hotspot development. These processes are generally difficult to isolate and monitor in the field because of the high degree of complexity and coupling between them. We report in situ experimental observations from the Ploemeur fractured rock observatory (http://hplus.ore.fr/en/ploemeur) that provide new insights on the dynamics of transport and reaction processes in fractured media. These include dipole and push pull tracer tests that allow understanding and modelling anomalous transport processes characterized by heavy-tailed residence time distributions (Kang et al. 2015), thermal push pull tests that show the existence of highly channeled flow with a strong control on fracture matrix exchanges (Klepikova et al. 2016) and time lapse hydrogeophysical monitoring of saline tracer tests that allow quantifying the distribution of transport length scales governing dispersion processes (Shakas et al. 2016). These transport processes are then shown to induce rapid oxygen delivery and mixing at depth leading to massive biofilm development (Bochet et al., in prep.). Hence, this presentation will attempt to link these observations made at different scales to quantify and model the coupling between flow channeling, non-Fickian transport, mixing and chemical reactions in fractured media. References: Bochet et al. Biofilm blooms driven by enhanced mixing in fractured rock, in prep. Klepikova et al. 2016, Heat as a tracer for understanding transport processes in fractured media: theory and field assessment from multi-scale thermal push-pull tracer tests, Water Resour. Res. 52Shakas et al. 2016, Hydrogeophysical characterization of transport processes in fractured rock by combining push-pull and single-hole ground penetrating radar experiments, Water Resour. Res. 52 Kang et al. 2015, Impact of velocity correlation and distribution on transport in fractured media : Field evidence and theoretical model, Water Resour. Res., 51

[Applying healthcare failure mode and effect analysis to improve the surgical specimen transportation process and rejection rate].

PubMed

Hu, Pao-Hsueh; Hu, Hsiao-Chen; Huang, Hui-Ju; Chao, Hui-Lin; Lei, Ei-Fang

2014-04-01

Because surgical pathology specimens are crucial to the diagnosis and treatment of disease, it is critical that they be collected and transported safely and securely. Due to recent near-miss events in our department, we used the healthcare failure model and effect analysis to identify 14 potential perils in the specimen collection and transportation process. Improvement and prevention strategies were developed accordingly to improve quality of care. Using health care failure mode and effect analysis (HFMEA) may improve the surgical specimen transportation process and reduce the rate of surgical specimen rejection. Rectify standard operating procedures for surgical pathology specimen collection and transportation. Create educational videos and posters. Rectify methods of specimen verification. Organize and create an online and instantaneous management system for specimen tracking and specimen rejection. Implementation of the new surgical specimen transportation process effectively eliminated the 14 identified potential perils. In addition, the specimen rejection fell from 0.86% to 0.03%. This project was applied to improve the specimen transportation process, enhance interdisciplinary cooperation, and improve the patient-centered healthcare system. The creation and implementation of an online information system significantly facilitates specimen tracking, hospital cost reductions, and patient safety improvements. The success in our department is currently being replicated across all departments in our hospital that transport specimens. Our experience and strategy may be applied to inter-hospital specimen transportation in the future.

Coexistence of passive and carrier-mediated processes in drug transport.

PubMed

Sugano, Kiyohiko; Kansy, Manfred; Artursson, Per; Avdeef, Alex; Bendels, Stefanie; Di, Li; Ecker, Gerhard F; Faller, Bernard; Fischer, Holger; Gerebtzoff, Grégori; Lennernaes, Hans; Senner, Frank

2010-08-01

The permeability of biological membranes is one of the most important determinants of the pharmacokinetic processes of a drug. Although it is often accepted that many drug substances are transported across biological membranes by passive transcellular diffusion, a recent hypothesis speculated that carrier-mediated mechanisms might account for the majority of membrane drug transport processes in biological systems. Based on evidence of the physicochemical characteristics and of in vitro and in vivo findings for marketed drugs, as well as results from real-life discovery and development projects, we present the view that both passive transcellular processes and carrier-mediated processes coexist and contribute to drug transport activities across biological membranes.

A Transportation Modeling Primer

DOT National Transportation Integrated Search

2006-06-01

This primer is intended to explain the urban transportation modeling process works, the assumptions made and the steps used to forecast travel demand for urban transportation planning. This is done in order to help to understand the process and its i...

The relationship of title VI requirements to Florida's transportation planning process.

DOT National Transportation Integrated Search

2011-10-01

The Florida Department of Transportation (FDOT) and metropolitan planning organizations (MPO) in Florida are : required to address Title VI and environmental justice (EJ) in the transportation planning process. This study : reviews those practices an...

Incorporating ITS solutions into the metropolitan transportation planning process : overcoming institutional barriers

DOT National Transportation Integrated Search

2000-11-01

There are three conditions that help bring ITS solutions into the metropolitan transportation planning process: Condition 1: Endorsement of ITS by Elected Officials and Transportation Managers Condition 2: Improved Communication and Coordination Acro...

Electron Transport Modeling of Molecular Nanoscale Bridges Used in Energy Conversion Schemes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunietz, Barry D

2016-08-09

The goal of the research program is to reliably describe electron transport and transfer processes at the molecular level. Such insight is essential for improving molecular applications of solar and thermal energy conversion. We develop electronic structure models to study (1) photoinduced electron transfer and transport processes in organic semiconducting materials, and (2) charge and heat transport through molecular bridges. We seek fundamental understanding of key processes, which lead to design new experiments and ultimately to achieve systems with improved properties.

Crew Transportation Technical Management Processes

NASA Technical Reports Server (NTRS)

Mckinnie, John M. (Compiler); Lueders, Kathryn L. (Compiler)

2013-01-01

Under the guidance of processes provided by Crew Transportation Plan (CCT-PLN-1100), this document, with its sister documents, International Space Station (ISS) Crew Transportation and Services Requirements Document (CCT-REQ-1130), Crew Transportation Technical Standards and Design Evaluation Criteria (CCT-STD-1140), Crew Transportation Operations Standards (CCT STD-1150), and ISS to Commercial Orbital Transportation Services Interface Requirements Document (SSP 50808), provides the basis for a National Aeronautics and Space Administration (NASA) certification for services to the ISS for the Commercial Provider. When NASA Crew Transportation System (CTS) certification is achieved for ISS transportation, the Commercial Provider will be eligible to provide services to and from the ISS during the services phase.

Risk-based framework using geographic information systems to identify transportation corridors vulnerable to development.

DOT National Transportation Integrated Search

2008-01-01

The Virginia Department of Transportation (VDOT) is increasingly involved with the land development process in evolving transportation corridors. This process includes consideration of real estate interests, rezoning and permitting approvals, site pl...

Generic reactive transport codes as flexible tools to integrate soil organic matter degradation models with water, transport and geochemistry in soils

NASA Astrophysics Data System (ADS)

Jacques, Diederik; Gérard, Fréderic; Mayer, Uli; Simunek, Jirka; Leterme, Bertrand

2016-04-01

A large number of organic matter degradation, CO2 transport and dissolved organic matter models have been developed during the last decades. However, organic matter degradation models are in many cases strictly hard-coded in terms of organic pools, degradation kinetics and dependency on environmental variables. The scientific input of the model user is typically limited to the adjustment of input parameters. In addition, the coupling with geochemical soil processes including aqueous speciation, pH-dependent sorption and colloid-facilitated transport are not incorporated in many of these models, strongly limiting the scope of their application. Furthermore, the most comprehensive organic matter degradation models are combined with simplified representations of flow and transport processes in the soil system. We illustrate the capability of generic reactive transport codes to overcome these shortcomings. The formulations of reactive transport codes include a physics-based continuum representation of flow and transport processes, while biogeochemical reactions can be described as equilibrium processes constrained by thermodynamic principles and/or kinetic reaction networks. The flexibility of these type of codes allows for straight-forward extension of reaction networks, permits the inclusion of new model components (e.g.: organic matter pools, rate equations, parameter dependency on environmental conditions) and in such a way facilitates an application-tailored implementation of organic matter degradation models and related processes. A numerical benchmark involving two reactive transport codes (HPx and MIN3P) demonstrates how the process-based simulation of transient variably saturated water flow (Richards equation), solute transport (advection-dispersion equation), heat transfer and diffusion in the gas phase can be combined with a flexible implementation of a soil organic matter degradation model. The benchmark includes the production of leachable organic matter and inorganic carbon in the aqueous and gaseous phases, as well as different decomposition functions with first-order, linear dependence or nonlinear dependence on a biomass pool. In addition, we show how processes such as local bioturbation (bio-diffusion) can be included implicitly through a Fickian formulation of transport of soil organic matter. Coupling soil organic matter models with generic and flexible reactive transport codes offers a valuable tool to enhance insights into coupled physico-chemical processes at different scales within the scope of C-biogeochemical cycles, possibly linked with other chemical elements such as plant nutrients and pollutants.

Using Decision Trees for Estimating Mode Choice of Trips in Buca-Izmir

NASA Astrophysics Data System (ADS)

Oral, L. O.; Tecim, V.

2013-05-01

Decision makers develop transportation plans and models for providing sustainable transport systems in urban areas. Mode Choice is one of the stages in transportation modelling. Data mining techniques can discover factors affecting the mode choice. These techniques can be applied with knowledge process approach. In this study a data mining process model is applied to determine the factors affecting the mode choice with decision trees techniques by considering individual trip behaviours from household survey data collected within Izmir Transportation Master Plan. From this perspective transport mode choice problem is solved on a case in district of Buca-Izmir, Turkey with CRISP-DM knowledge process model.

Transport phenomena in environmental engineering

NASA Astrophysics Data System (ADS)

Sander, Aleksandra; Kardum, Jasna Prlić; Matijašić, Gordana; Žižek, Krunoslav

2018-01-01

A term transport phenomena arises as a second paradigm at the end of 1950s with high awareness that there was a strong need to improve the scoping of chemical engineering science. At that point, engineers became highly aware that it is extremely important to take step forward from pure empirical description and the concept of unit operations only to understand the specific process using phenomenological equations that rely on three elementary physical processes: momentum, energy and mass transport. This conceptual evolution of chemical engineering was first presented with a well-known book of R. Byron Bird, Warren E. Stewart and Edwin N. Lightfoot, Transport Phenomena, published in 1960 [1]. What transport phenomena are included in environmental engineering? It is hard to divide those phenomena through different engineering disciplines. The core is the same but the focus changes. Intention of the authors here is to present the transport phenomena that are omnipresent in treatment of various process streams. The focus in this chapter is made on the transport phenomena that permanently occur in mechanical macroprocesses of sedimentation and filtration for separation in solid-liquid particulate systems and on the phenomena of the flow through a fixed and a fluidized bed of particles that are immanent in separation processes in packed columns and in environmental catalysis. The fundamental phenomena for each thermal and equilibrium separation process technology are presented as well. Understanding and mathematical description of underlying transport phenomena result in scoping the separation processes in a way that ChEs should act worldwide.

Direct monitoring of wind-induced pressure-pumping on gas transport in soil

NASA Astrophysics Data System (ADS)

Laemmel, Thomas; Mohr, Manuel; Schindler, Dirk; Schack-Kirchner, Helmer; Maier, Martin

2017-04-01

Gas exchange between soil and atmosphere is important for the biogeochemistry of soils and is commonly assumed to be governed by molecular diffusion. Yet a few previous field studies identified other gas transport processes such as wind-induced pressure-pumping to enhance soil-atmosphere fluxes significantly. However, since these wind-induced non-diffusive gas transport processes in soil often occur intermittently, the quantification of their contribution to soil gas emissions is challenging. To quantify the effects of wind-induced pressure-pumping on soil gas transport, we developed a method for in situ monitoring of soil gas transport. The method includes the use of Helium (He) as a tracer gas which was continuously injected into the soil. The resulting He steady-state concentration profile was monitored. Gas transport parameters of the soil were inversely modelled. We used our method during a field campaign in a well-aerated forest soil over three months. During periods of low wind speed, soil gas transport was modelled assuming diffusion as transport process. During periods of high wind speed, the previously steady diffusive He concentration profile showed temporary concentration decreases in the topsoil, indicating an increase of the effective gas transport rate in the topsoil up to 30%. The enhancement of effective topsoil soil gas diffusivity resulted from wind-induced air pressure fluctuations which are referred to as pressure-pumping. These air pressure fluctuations had frequencies between 0.1 and 0.01 Hz and amplitudes up to 10 Pa and occurred at above-canopy wind speeds greater than 5 m s-1. We could show the importance of the enhancement of the gas transport rate in relation with the wind intensity and corresponding air pressure fluctuations characteristics. We directly detected and quantified the pressure-pumping effect on gas transport in soil in a field study for the first time, and could thus validate and underpin the importance of this non-diffusive gas transport process. Our method can also be used to study other non-diffusive gas transport processes occurring in soil and snow, and their possible feedbacks or interactions with biogeochemical processes.

A primer on safety performance measures for the transportation planning process

DOT National Transportation Integrated Search

2009-09-01

This Primer is a tool to help State and local practitioners, transportation planners, and decision-makers identify, select, and use safety performance measures as a part of the transportation planning process. The Primer draws from current literature...

Erosion and Sediment Transport Modelling in Shallow Waters: A Review on Approaches, Models and Applications.

PubMed

Hajigholizadeh, Mohammad; Melesse, Assefa M; Fuentes, Hector R

2018-03-14

The erosion and sediment transport processes in shallow waters, which are discussed in this paper, begin when water droplets hit the soil surface. The transport mechanism caused by the consequent rainfall-runoff process determines the amount of generated sediment that can be transferred downslope. Many significant studies and models are performed to investigate these processes, which differ in terms of their effecting factors, approaches, inputs and outputs, model structure and the manner that these processes represent. This paper attempts to review the related literature concerning sediment transport modelling in shallow waters. A classification based on the representational processes of the soil erosion and sediment transport models (empirical, conceptual, physical and hybrid) is adopted, and the commonly-used models and their characteristics are listed. This review is expected to be of interest to researchers and soil and water conservation managers who are working on erosion and sediment transport phenomena in shallow waters. The paper format should be helpful for practitioners to identify and generally characterize the types of available models, their strengths and their basic scope of applicability.

Erosion and Sediment Transport Modelling in Shallow Waters: A Review on Approaches, Models and Applications

PubMed Central

Fuentes, Hector R.

2018-01-01

The erosion and sediment transport processes in shallow waters, which are discussed in this paper, begin when water droplets hit the soil surface. The transport mechanism caused by the consequent rainfall-runoff process determines the amount of generated sediment that can be transferred downslope. Many significant studies and models are performed to investigate these processes, which differ in terms of their effecting factors, approaches, inputs and outputs, model structure and the manner that these processes represent. This paper attempts to review the related literature concerning sediment transport modelling in shallow waters. A classification based on the representational processes of the soil erosion and sediment transport models (empirical, conceptual, physical and hybrid) is adopted, and the commonly-used models and their characteristics are listed. This review is expected to be of interest to researchers and soil and water conservation managers who are working on erosion and sediment transport phenomena in shallow waters. The paper format should be helpful for practitioners to identify and generally characterize the types of available models, their strengths and their basic scope of applicability. PMID:29538335

49 CFR 40.327 - When must the MRO report medical information gathered in the verification process?

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 1 2011-10-01 2011-10-01 false When must the MRO report medical information gathered in the verification process? 40.327 Section 40.327 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Confidentiality and Release of Information § 40.327 When must...

Availability Control for Means of Transport in Decisive Semi-Markov Models of Exploitation Process

NASA Astrophysics Data System (ADS)

Migawa, Klaudiusz

2012-12-01

The issues presented in this research paper refer to problems connected with the control process for exploitation implemented in the complex systems of exploitation for technical objects. The article presents the description of the method concerning the control availability for technical objects (means of transport) on the basis of the mathematical model of the exploitation process with the implementation of the decisive processes by semi-Markov. The presented method means focused on the preparing the decisive for the exploitation process for technical objects (semi-Markov model) and after that specifying the best control strategy (optimal strategy) from among possible decisive variants in accordance with the approved criterion (criteria) of the activity evaluation of the system of exploitation for technical objects. In the presented method specifying the optimal strategy for control availability in the technical objects means a choice of a sequence of control decisions made in individual states of modelled exploitation process for which the function being a criterion of evaluation reaches the extreme value. In order to choose the optimal control strategy the implementation of the genetic algorithm was chosen. The opinions were presented on the example of the exploitation process of the means of transport implemented in the real system of the bus municipal transport. The model of the exploitation process for the means of transports was prepared on the basis of the results implemented in the real transport system. The mathematical model of the exploitation process was built taking into consideration the fact that the model of the process constitutes the homogenous semi-Markov process.

49 CFR 1560.205 - Redress process.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation (Continued) TRANSPORTATION SECURITY ADMINISTRATION... may obtain the forms and information necessary to initiate the redress process on the DHS TRIP Web... will provide the necessary forms and information to individuals through its Web site or by mail. (c...

ISS Crew Transportation and Services Requirements Document

NASA Technical Reports Server (NTRS)

Lueders, Kathryn L. (Compiler)

2015-01-01

Under the guidance of processes provided by Crew Transportation Plan (CCT-PLN-1100), this document with its sister documents, Crew Transportation Technical Management Processes (CCT-PLN-1120), Crew Transportation Technical Standards and Design Evaluation Criteria (CCT-STD-1140), and Crew Transportation Operations Standards (CCT-STD-1150), and International Space Station (ISS) to Commercial Orbital Transportation Services Interface Requirements Document (SSP 50808), provides the basis for a National Aeronautics and Space Administration (NASA) certification for services to the ISS for the Commercial Provider. When NASA Crew Transportation System (CTS) certification is achieved for ISS transportation, the Commercial Provider will be eligible to provide services to and from the ISS during the services phase of the NASA Commercial Crew Program (CCP).

Not planning a sustainable transport system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finnveden, Göran, E-mail: goran.finnveden@abe.kth.se; Åkerman, Jonas

2014-04-01

The overall objective of the Swedish transport policy is to ensure the economically efficient and sustainable provision of transport services for people and business throughout the country. More specifically, the transport sector shall, among other things, contribute to the achievement of environmental quality objectives in which the development of the transport system plays an important role in the achievement of the objectives. The aim of this study is to analyse if current transport planning supports this policy. This is done by analysing two recent cases: the National Infrastructure Plan 2010–2021, and the planning of Bypass Stockholm, a major road investment.more » Our results show that the plans are in conflict with several of the environmental quality objectives. Another interesting aspect of the planning processes is that the long-term climate goals are not included in the planning processes, neither as a clear goal nor as factor that will influence future transport systems. In this way, the long-term sustainability aspects are not present in the planning. We conclude that the two cases do not contribute to a sustainable transport system. Thus, several changes must be made in the processes, including putting up clear targets for emissions. Also, the methodology for the environmental assessments needs to be further developed and discussed. - Highlights: • Two cases are studied to analyse if current planning supports a sustainable transport system. • Results show that the plans are in conflict with several of the environmental quality objectives. • Long-term climate goals are not included in the planning processes. • Current practices do not contribute to a sustainable planning processes. • Methodology and process for environmental assessments must be further developed and discussed.« less

Every Place Counts Leadership Academy transportation toolkit

DOT National Transportation Integrated Search

2016-12-01

The Transportation Toolkit is meant to explain the transportation process to members of the public with no prior knowledge of transportation. The Toolkit is meant to demystify transportation and help people engage in local transportation decision-mak...

Contaminant Attenuation and Transport Characterization of 200-UP-1 Operable Unit Sediment Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Brady D.; Szecsody, James E.; Qafoku, Nikolla

Contaminants disposed of at the land surface migrate through the vadose zone, forming plumes in groundwater. Processes that occur in the groundwater can attenuate contaminant concentrations during transport through the aquifer. For this reason, quantifying contaminant attenuation and contaminant transport processes in the aquifer, in support of the conceptual site model (CSM) and fate and transport modeling, are important for assessing the need for, and type of, remediation in the groundwater, including monitored natural attenuation (MNA). The framework to characterize attenuation and transport processes provided in U.S. Environmental Protection Agency (EPA) guidance documents was used to guide the laboratory effortmore » reported herein.« less

Membrane ion transport in non-excitable tissues.

PubMed Central

Nehrke, Keith

2014-01-01

The facilitated movement of ions across cell membranes can be characterized as occurring through active (ATP-dependent), secondary active (coupled), or passive transport processes. Each of these processes is mediated by a diverse group of membrane proteins. Over the past fifteen years, studies of membrane transport in C. elegans have benefited from the fact that worms are anatomically simple, easily and economically cultured, and genetically tractable. These experimental advantages have been instrumental in defining how membrane transport processes contribute to whole organism physiology. The focus of this review is to survey the recent advances in our understanding of membrane transport that have arisen from integrative physiological approaches in the nematode C. elegans. PMID:25536490

Connected vehicle impacts on transportation planning technical memorandum #2 : connected vehicle planning processes and products and stakeholder roles and responsibilities.

DOT National Transportation Integrated Search

2015-01-01

The objective of this project, Connected Vehicle Impacts on Transportation Planning, is to comprehensively assess how connected vehicles should be considered across the range of transportation planning processes and products developed by States...

76 FR 22878 - Defense Transportation Regulation, Part IV

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-25

... Military Services, DFAS and SDDC. In addition, the proposed electronic billing processes will compliment... in the Defense Transportation Regulation (DTR) Part IV (DTR 4500.9R). This process proposes mandatory... Transportation Service Providers (TSP). Implementation of electronic payments for NTS at all Military Services...

PREFACE: Functionalized Liquid Liquid Interfaces

NASA Astrophysics Data System (ADS)

Girault, Hubert; Kornyshev, Alexei A.; Monroe, Charles W.; Urbakh, Michael

2007-09-01

Most natural processes take place at interfaces. For this reason, surface science has been a focal point of modern research. At solid-liquid interfaces one can induce various species to adsorb or react, and thus may study interactions between the substrate and adsorbates, kinetic processes, optical properties, etc. Liquid-liquid interfaces, formed by immiscible liquids such as water and oil, have a number of distinctive features. Both sides of the interface are amenable to detailed physical and chemical analysis. By chemical or electrochemical means, metal or semiconductor nanoparticles can be formed or localised at the interface. Surfactants can be used to tailor surface properties, and also to place organic molecular or supermolecular constructions at the boundary between the liquids. Electric fields can be used to drive ions from one fluid to another, or even change the shape of the interface itself. In many cases, both liquids are optically transparent, making functionalized liquid-liquid interfaces promising for various optical applications based on the transmission or reflection of light. An advantage common to most of these systems is self-assembly; because a liquid-liquid interface is not mechanically constrained like a solid-liquid interface, it can easily access its most stable state, even after it has been driven far from equilibrium. This special issue focuses on four modes of liquid-liquid interfacial functionalization: the controlled adsorption of molecules or nanoparticles, the formation of adlayers or films, electrowetting, and ion transfer or interface-localized reactions. Interfacial adsorption can be driven electrically, chemically, or mechanically. The liquid-liquid interface can be used to study how anisotropic particles orient at a surface under the influence of a field, how surfactants interact with other adsorbates, and how nanoparticles aggregate; the transparency of the interface also makes the chirality of organic adsorbates amenable to optical study. Film formation goes a step beyond adsorption; some surfactants form monolayers or multilayers at the interface. A polymer microfilm or a polymer-particle matrix can be synthesized at the liquid-liquid boundary. Such films exhibit unique adsorption and ion-intercalation properties of their own. Electrowetting refers broadly to the phenomenon in which an applied voltage modulates the shape of a liquid-liquid interface, essentially by altering the surface tension. Electric fields can be used to induce droplets on solid substrates to change shape, or to affect the structure of liquid-liquid emulsions. Various chemical reactions can be performed at the liquid-liquid boundary. Liquid-liquid microelectrodes allow detailed study of ion-transfer kinetics at the interface. Photochemical processes can also be used to control the conformations of molecules adsorbed at the interface. But how much precise control do we actually have on the state of the interfacial region? Several contributions to this issue address a system which has been studied for decades in electrochemistry, but remains essentially unfamilar to physicists. This is the interface between two immiscible electrolytic solutions (ITIES), a progressing interdisciplinary field in which condensed-matter physics and physical chemistry meet molecular electrochemistry. Why is it so exciting? The reason is simple. The ITIES is chargeable: when positioned between two electrodes it can be polarized, and back- to-back electrical double layers form on both sides of the liquid-liquid interface. Importantly, the term immiscible refers not only to oil and water but also to the electrolytes. Inorganic electrolytes, such as alkali halides, tend to stay in water, whereas organic electrolytes, such as tetrabutylammonium tetraphenylborate, stay in oil. This behaviour arises because energies of the order of 0.2-0.3 eV are needed to drive ions across the interface. As long as these free energies of transfer are not exceeded by the external potential bias, the ITIES works as an 'electrode'; there is no traffic of ions across it. Thus the interface can sustain fields of the order of 106 V/cm, which are localized in a nanoscopic layer near the interface. This gives many new options for building various kinds of electrically tunable self assembled moloecular devices. Through the years, ITIES have been considered by electrochemists as a popular biomimetic model system, or for studies of interfacial reaction kinetics; ITIES were also used in industrial phase-transfer catalysis. Recently, this system has opened up new options for nano-scale engineering of functional assemblies (for dense information storage, efficient energy conversion, light-harvesting, and miniaturized sensors), which justifies its presentation in this issue.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Liange; Li, Lianchong; Rutqvist, Jonny

Clay/shale has been considered as potential host rock for geological disposal of high-level nuclear waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures induced by tunnel excavation. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus Clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at the Mol site, Belgium (Barnichon and Volckaert, 2003) have all been under intensive scientific investigation (at both field and laboratorymore » scales) for understanding a variety of rock properties and their relationships to flow and transport processes associated with geological disposal of nuclear waste. Clay/shale formations may be generally classified as indurated or plastic clays (Tsang and Hudson, 2010). The latter (including Boom clay) is a softer material without high cohesion; its deformation is dominantly plastic. During the lifespan of a clay repository, the repository performance is affected by complex thermal, hydrogeological, mechanical, chemical (THMC) processes, such as heat release due to radionuclide decay, multiphase flow, formation of damage zones, radionuclide transport, waste dissolution, and chemical reactions. All these processes are related to each other. An in-depth understanding of these coupled processes is critical for the performance assessment (PA) of the repository. These coupled processes may affect radionuclide transport by changing transport paths (e.g., formation and evolution of excavation damaged zone (EDZ)) and altering flow, mineral, and mechanical properties that are related to radionuclide transport. While radionuclide transport in clay formation has been studied using laboratory tests (e,g, Appelo et al. 2010, Garcia-Gutierrez et al., 2008, Maes et al., 2008), short-term field tests (e.g. Garcia-Gutierrez et al. 2006, Soler et al. 2008, van Loon et al. 2004, Wu et al. 2009) and numerical modeling (de Windt et al. 2003; 2006), the effects of THMC processes on radionuclide transport are not fully investigated. The objectives of the research activity documented in this report are to improve a modeling capability for coupled THMC processes and to use it to evaluate the THMC impacts on radionuclide transport. This research activity addresses several key Features, Events and Processes (FEPs), including FEP 2.2.08, Hydrologic Processes, FEP 2.2.07, Mechanical Processes and FEP 2.2.09, Chemical Process— Transport, by studying near-field coupled THMC processes in clay/shale repositories and their impacts on radionuclide transport. This report documents the progress that has been made in FY12. Section 2 discusses the development of THMC modeling capability. Section 3 reports modeling results of THMC impacts on radionuclide transport. Planned work for the remaining months of FY12 and proposed work for FY13 are presented in Section 4.« less

Idaho Bicycle and Pedestrian Transportation

DOT National Transportation Integrated Search

1995-01-01

The Idaho Bicycle and Pedestrian Transportation Plan of Idaho's long range transportation planning process sets the stage for changes in our transportation mix. The plan is about expanding options for personal transportation. Most importantly, it is ...

The peculiarities of process-based approach realization in transport sector company management

NASA Astrophysics Data System (ADS)

Khripko, Elena; Sidorov, Gennadiy

2017-10-01

In the present article we study the phenomena of multiple meaning in understanding process-based management method in construction of transport infrastructure facilities. The idea of multiple meaning is in distortions which appear during reception of the management process paradigm in organizational environment of transport sector. The cause of distortion in process management is organizational resistance. The distortions of management processes are discovered at the level of diffusion among spheres of responsibility, collision in forms of functional, project and process interaction between the owner of the process and its participants. The level of distortion is affected by the attitude towards the result of work which means that process understanding of the result is replaced by the functional one in practice of management. This transfiguration is the consequence of regressive defensive mechanisms of the organizational environment. On the base of experience of forming process management in construction of transport infrastructure facilities company of the issues of diagnostics of various forms of organizational resistance and ways of reducing the destructive influence on managing processes are reviewed.

Every Place Counts Leadership Academy : transportation toolkit quick guide

DOT National Transportation Integrated Search

2016-12-01

This is a quick guide to the Transportation Toolkit. The Transportation Toolkit is meant to explain the transportation process to members of the public with no prior knowledge of transportation. The Toolkit is meant to demystify transportation and he...

Application of fuzzy neural network technologies in management of transport and logistics processes in Arctic

NASA Astrophysics Data System (ADS)

Levchenko, N. G.; Glushkov, S. V.; Sobolevskaya, E. Yu; Orlov, A. P.

2018-05-01

The method of modeling the transport and logistics process using fuzzy neural network technologies has been considered. The analysis of the implemented fuzzy neural network model of the information management system of transnational multimodal transportation of the process showed the expediency of applying this method to the management of transport and logistics processes in the Arctic and Subarctic conditions. The modular architecture of this model can be expanded by incorporating additional modules, since the working conditions in the Arctic and the subarctic themselves will present more and more realistic tasks. The architecture allows increasing the information management system, without affecting the system or the method itself. The model has a wide range of application possibilities, including: analysis of the situation and behavior of interacting elements; dynamic monitoring and diagnostics of management processes; simulation of real events and processes; prediction and prevention of critical situations.

Influence of reservoirs on solute transport: A regional-scale approach

USGS Publications Warehouse

Kelly, V.J.

2001-01-01

Regional transport of water and dissolved constituents through heavily regulated river systems is influenced by the presence of reservoirs. Analysis of seasonal patterns in solute fluxes for salinity and nutrients indicates that in-reservoir processes within large storage reservoirs in the Rio Grande and Colorado basins (southwestern USA) are superimposed over the underlying watershed processes that predominate in relatively unregulated stream reaches. Connectivity of the aquatic system with the landscape is apparently disrupted by processes within the reservoir systems; these processes result in large changes in characteristics for solute transport that persist downstream in the absence of significant inputs. Additionally, reservoir processes may be linked for upstream/downstream reservoirs that are located relatively close in a series. In contrast, the regional effect of in-reservoir processes is negligible for solute transport through run-of-river reservoirs in the lower Columbia River (northwestern USA).

The Need for a Kinetics for Biological Transport

PubMed Central

Schindler, A. M.; Iberall, A. S.

1973-01-01

The traditional theory of transport across capillary membranes via a laminar Poiseuille flow is shown to be invalid. It is demonstrated that the random, diffusive nature of the molecular flow and interactions with the “pore” walls play an important role in the transport process. Neither the continuum Navier-Stokes theory nor the equivalent theory of irreversible thermodynamics is adequate to treat the problem. Combination of near-continuum hydrodynamic theory, noncontinuum kinetic theory, and the theory of fluctuations provides a first step toward modeling both liquid processes in general and membrane transport processes as a specific application. PMID:4726880

Ceramic oxygen transport membrane array reactor and reforming method

DOEpatents

Kelly, Sean M.; Christie, Gervase Maxwell; Robinson, Charles; Wilson, Jamie R; Gonzalez, Javier E.; Doraswami, Uttam R.

2017-10-03

The invention relates to a commercially viable modular ceramic oxygen transport membrane system for utilizing heat generated in reactively-driven oxygen transport membrane tubes to generate steam, heat process fluid and/or provide energy to carry out endothermic chemical reactions. The system provides for improved thermal coupling of oxygen transport membrane tubes to steam generation tubes or process heater tubes or reactor tubes for efficient and effective radiant heat transfer.

THE INTERPLAY BETWEEN GEOCHEMICAL REACTIONS AND ADVECTION-DISPERSION IN CONTAMINANT TRANSPORT AT A URANIUM MILL TAILINGS SITE

EPA Science Inventory

It is well known that the fate and transport of contaminants in the subsurface are controlled by complex processes including advection, dispersion-diffusion, and chemical reactions. However, the interplay between the physical transport processes and chemical reactions, and their...

Boron transport in plants: co-ordinated regulation of transporters

PubMed Central

Miwa, Kyoko; Fujiwara, Toru

2010-01-01

Background The essentiality of boron (B) for plant growth was established >85 years ago. In the last decade, it has been revealed that one of the physiological roles of B is cross-linking the pectic polysaccharide rhamnogalacturonan II in primary cell walls. Borate cross-linking of pectic networks serves both for physical strength of cell walls and for cell adhesion. On the other hand, high concentrations of B are toxic to plant growth. To avoid deficiency and toxicity problems, it is important for plants to maintain their tissue B concentrations within an optimum range by regulating transport processes. Boron transport was long believed to be a passive, unregulated process, but the identification of B transporters has suggested that plants sense and respond to the B conditions and regulate transporters to maintain B homeostasis. Scope Transporters responsible for efficient B uptake by roots, xylem loading and B distribution among leaves have been described. These transporters are required under B limitation for efficient acquisition and utilization of B. Transporters important for tolerating high B levels in the environment have also been identified, and these transporters export B from roots back to the soil. Two types of transporters are involved in these processes: NIPs (nodulin-26-like intrinsic proteins), boric acid channels, and BORs, B exporters. It is demonstrated that the expression of genes encoding these transporters is finely regulated in response to B availability in the environment to ensure tissue B homeostasis. Furthermore, plants tolerant to stress produced by low B or high B in the environment can be generated through altered expression of these transporters. Conclusions The identification of the first B transporter led to the discovery that B transport was a process mediated not only by passive diffusion but also by transporters whose activity was regulated in response to B conditions. Now it is evident that plants sense internal and external B conditions and regulate B transport by modulating the expression and/or accumulation of these transporters. Results obtained in model plants are applicable to other plant species, and such knowledge may be useful in designing plants or crops tolerant to soils containing low or high B. PMID:20228086

Modeling the impact of changing patient transportation systems on peri-operative process performance in a large hospital: insights from a computer simulation study.

PubMed

Segev, Danny; Levi, Retsef; Dunn, Peter F; Sandberg, Warren S

2012-06-01

Transportation of patients is a key hospital operational activity. During a large construction project, our patient admission and prep area will relocate from immediately adjacent to the operating room suite to another floor of a different building. Transportation will require extra distance and elevator trips to deliver patients and recycle transporters (specifically: personnel who transport patients). Management intuition suggested that starting all 52 first cases simultaneously would require many of the 18 available elevators. To test this, we developed a data-driven simulation tool to allow decision makers to simultaneously address planning and evaluation questions about patient transportation. We coded a stochastic simulation tool for a generalized model treating all factors contributing to the process as JAVA objects. The model includes elevator steps, explicitly accounting for transporter speed and distance to be covered. We used the model for sensitivity analyses of the number of dedicated elevators, dedicated transporters, transporter speed and the planned process start time on lateness of OR starts and the number of cases with serious delays (i.e., more than 15 min). Allocating two of the 18 elevators and 7 transporters reduced lateness and the number of cases with serious delays. Additional elevators and/or transporters yielded little additional benefit. If the admission process produced ready-for-transport patients 20 min earlier, almost all delays would be eliminated. Modeling results contradicted clinical managers' intuition that starting all first cases on time requires many dedicated elevators. This is explained by the principle of decreasing marginal returns for increasing capacity when there are other limiting constraints in the system.

Optimisation of logistics processes of energy grass collection

NASA Astrophysics Data System (ADS)

Bányai, Tamás.

2010-05-01

The collection of energy grass is a logistics-intensive process [1]. The optimal design and control of transportation and collection subprocesses is a critical point of the supply chain. To avoid irresponsible decisions by right of experience and intuition, the optimisation and analysis of collection processes based on mathematical models and methods is the scientific suggestible way. Within the frame of this work, the author focuses on the optimisation possibilities of the collection processes, especially from the point of view transportation and related warehousing operations. However the developed optimisation methods in the literature [2] take into account the harvesting processes, county-specific yields, transportation distances, erosion constraints, machinery specifications, and other key variables, but the possibility of more collection points and the multi-level collection were not taken into consideration. The possible areas of using energy grass is very wide (energetically use, biogas and bio alcohol production, paper and textile industry, industrial fibre material, foddering purposes, biological soil protection [3], etc.), so not only a single level but also a multi-level collection system with more collection and production facilities has to be taken into consideration. The input parameters of the optimisation problem are the followings: total amount of energy grass to be harvested in each region; specific facility costs of collection, warehousing and production units; specific costs of transportation resources; pre-scheduling of harvesting process; specific transportation and warehousing costs; pre-scheduling of processing of energy grass at each facility (exclusive warehousing). The model take into consideration the following assumptions: (1) cooperative relation among processing and production facilties, (2) capacity constraints are not ignored, (3) the cost function of transportation is non-linear, (4) the drivers conditions are ignored. The objective function of the optimisation is the maximisation of the profit which means the maximization of the difference between revenue and cost. The objective function trades off the income of the assigned transportation demands against the logistic costs. The constraints are the followings: (1) the free capacity of the assigned transportation resource is more than the re-quested capacity of the transportation demand; the calculated arrival time of the transportation resource to the harvesting place is not later than the requested arrival time of them; (3) the calculated arrival time of the transportation demand to the processing and production facility is not later than the requested arrival time; (4) one transportation demand is assigned to one transportation resource and one resource is assigned to one transportation resource. The decision variable of the optimisation problem is the set of scheduling variables and the assignment of resources to transportation demands. The evaluation parameters of the optimised system are the followings: total costs of the collection process; utilisation of transportation resources and warehouses; efficiency of production and/or processing facilities. However the multidimensional heuristic optimisation method is based on genetic algorithm, but the routing sequence of the optimisation works on the base of an ant colony algorithm. The optimal routes are calculated by the aid of the ant colony algorithm as a subroutine of the global optimisation method and the optimal assignment is given by the genetic algorithm. One important part of the mathematical method is the sensibility analysis of the objective function, which shows the influence rate of the different input parameters. Acknowledgements This research was implemented within the frame of the project entitled "Development and operation of the Technology and Knowledge Transfer Centre of the University of Miskolc". with support by the European Union and co-funding of the European Social Fund. References [1] P. R. Daniel: The Economics of Harvesting and Transporting Corn Stover for Conversion to Fuel Ethanol: A Case Study for Minnesota. University of Minnesota, Department of Applied Economics. 2006. http://ideas.repec.org/p/ags/umaesp/14213.html [2] T. G. Douglas, J. Brendan, D. Erin & V.-D. Becca: Energy and Chemicals from Native Grasses: Production, Transportation and Processing Technologies Considered in the Northern Great Plains. University of Minnesota, Department of Applied Economics. 2006. http://ideas.repec.org/p/ags/umaesp/13838.html [3] Homepage of energygrass. www.energiafu.hu

The thermodynamics of pyrochemical processes for liquid metal reactor fuel cycles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, I.

1987-01-01

The thermodynamic basis for pyrochemical processes for the recovery and purification of fuel for the liquid metal reactor fuel cycle is described. These processes involve the transport of the uranium and plutonium from one liquid alloy to another through a molten salt. The processes discussed use liquid alloys of cadmium, zinc, and magnesium and molten chloride salts. The oxidation-reduction steps are done either chemically by the use of an auxiliary redox couple or electrochemically by the use of an external electrical supply. The same basic thermodynamics apply to both the salt transport and the electrotransport processes. Large deviations from idealmore » solution behavior of the actinides and lanthanides in the liquid alloys have a major influence on the solubilities and the performance of both the salt transport and electrotransport processes. Separation of plutonium and uranium from each other and decontamination from the more noble fission product elements can be achieved using both transport processes. The thermodynamic analysis is used to make process design computations for different process conditions.« less

Prioritized Contact Transport Stream

NASA Technical Reports Server (NTRS)

Hunt, Walter Lee, Jr. (Inventor)

2015-01-01

A detection process, contact recognition process, classification process, and identification process are applied to raw sensor data to produce an identified contact record set containing one or more identified contact records. A prioritization process is applied to the identified contact record set to assign a contact priority to each contact record in the identified contact record set. Data are removed from the contact records in the identified contact record set based on the contact priorities assigned to those contact records. A first contact stream is produced from the resulting contact records. The first contact stream is streamed in a contact transport stream. The contact transport stream may include and stream additional contact streams. The contact transport stream may be varied dynamically over time based on parameters such as available bandwidth, contact priority, presence/absence of contacts, system state, and configuration parameters.

Measurement of action spectra of light-activated processes

NASA Astrophysics Data System (ADS)

Ross, Justin; Zvyagin, Andrei V.; Heckenberg, Norman R.; Upcroft, Jacqui; Upcroft, Peter; Rubinsztein-Dunlop, Halina H.

2006-01-01

We report on a new experimental technique suitable for measurement of light-activated processes, such as fluorophore transport. The usefulness of this technique is derived from its capacity to decouple the imaging and activation processes, allowing fluorescent imaging of fluorophore transport at a convenient activation wavelength. We demonstrate the efficiency of this new technique in determination of the action spectrum of the light mediated transport of rhodamine 123 into the parasitic protozoan Giardia duodenalis.

A survey of transportation planning practices in state departments of transportation.

DOT National Transportation Integrated Search

1999-03-01

The Intermodal Surface Transportation Efficiency Act (ISTEA), and now its successor the Transportation Equity Act for the 21st Century (TEA-21), fundamentally altered the transportation planning process, providing new opportunities and new challenges...

49 CFR 107.117 - Emergency processing.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS AND OIL TRANSPORTATION HAZARDOUS MATERIALS... than the hazardous material to be transported) that could not be prevented if the application were...

49 CFR 107.117 - Emergency processing.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS AND OIL TRANSPORTATION HAZARDOUS MATERIALS... than the hazardous material to be transported) that could not be prevented if the application were...

Generalized free-space diffuse photon transport model based on the influence analysis of a camera lens diaphragm.

PubMed

Chen, Xueli; Gao, Xinbo; Qu, Xiaochao; Chen, Duofang; Ma, Xiaopeng; Liang, Jimin; Tian, Jie

2010-10-10

The camera lens diaphragm is an important component in a noncontact optical imaging system and has a crucial influence on the images registered on the CCD camera. However, this influence has not been taken into account in the existing free-space photon transport models. To model the photon transport process more accurately, a generalized free-space photon transport model is proposed. It combines Lambertian source theory with analysis of the influence of the camera lens diaphragm to simulate photon transport process in free space. In addition, the radiance theorem is also adopted to establish the energy relationship between the virtual detector and the CCD camera. The accuracy and feasibility of the proposed model is validated with a Monte-Carlo-based free-space photon transport model and physical phantom experiment. A comparison study with our previous hybrid radiosity-radiance theorem based model demonstrates the improvement performance and potential of the proposed model for simulating photon transport process in free space.

Nucleobase and nucleoside transport and integration into plant metabolism

PubMed Central

Girke, Christopher; Daumann, Manuel; Niopek-Witz, Sandra; Möhlmann, Torsten

2014-01-01

Nucleotide metabolism is an essential process in all living organisms. Besides newly synthesized nucleotides, the recycling (salvage) of partially degraded nucleotides, i.e., nucleosides and nucleobases serves to keep the homeostasis of the nucleotide pool. Both types of metabolites are substrates of at least six families of transport proteins in Arabidopsis thaliana (Arabidopsis) with a total of 49 members. In the last years several members of such transport proteins have been analyzed allowing to present a more detailed picture of nucleoside and nucleobase transport and the physiological function of these processes. Besides functioning in nucleotide metabolism it turned out that individual members of the before named transporters exhibit the capacity to transport a wide range of different substrates including vitamins and phytohormones. The aim of this review is to summarize the current knowledge on nucleobase and nucleoside transport processes in plants and integrate this into nucleotide metabolism in general. Thereby, we will focus on those proteins which have been characterized at the biochemical level. PMID:25250038

Multiple Choice Knapsack Problem: example of planning choice in transportation.

PubMed

Zhong, Tao; Young, Rhonda

2010-05-01

Transportation programming, a process of selecting projects for funding given budget and other constraints, is becoming more complex as a result of new federal laws, local planning regulations, and increased public involvement. This article describes the use of an integer programming tool, Multiple Choice Knapsack Problem (MCKP), to provide optimal solutions to transportation programming problems in cases where alternative versions of projects are under consideration. In this paper, optimization methods for use in the transportation programming process are compared and then the process of building and solving the optimization problems is discussed. The concepts about the use of MCKP are presented and a real-world transportation programming example at various budget levels is provided. This article illustrates how the use of MCKP addresses the modern complexities and provides timely solutions in transportation programming practice. While the article uses transportation programming as a case study, MCKP can be useful in other fields where a similar decision among a subset of the alternatives is required. Copyright 2009 Elsevier Ltd. All rights reserved.

Modeling of active transmembrane transport in a mixture theory framework.

PubMed

Ateshian, Gerard A; Morrison, Barclay; Hung, Clark T

2010-05-01

This study formulates governing equations for active transport across semi-permeable membranes within the framework of the theory of mixtures. In mixture theory, which models the interactions of any number of fluid and solid constituents, a supply term appears in the conservation of linear momentum to describe momentum exchanges among the constituents. In past applications, this momentum supply was used to model frictional interactions only, thereby describing passive transport processes. In this study, it is shown that active transport processes, which impart momentum to solutes or solvent, may also be incorporated in this term. By projecting the equation of conservation of linear momentum along the normal to the membrane, a jump condition is formulated for the mechano-electrochemical potential of fluid constituents which is generally applicable to nonequilibrium processes involving active transport. The resulting relations are simple and easy to use, and address an important need in the membrane transport literature.

Sediment transport processes in estuaries: An introduction

NASA Astrophysics Data System (ADS)

Perillo, Gerardo M. E.; Lavelle, J. William

1989-10-01

Research on estuarine sediment transport processes has received increasing attention in recent years, attention related to concerns about water clarity, pollutant distribution and transport, dredge spoil disposal, creation and maintenance of channels and basins for navigational purposes, and shoreline erosion. Still, the geophysical community that addresses these concerns and the underlying fundamentals of sediment transport in an estuary is widely but relatively sparsely distributed around the world. The need to draw these researchers together to discuss ideas and outlooks led to the AGU Chapman Conference on Sediment Transport Processes in Estuaries that was held at the Universidad Nacional del Sur in Bahía Bianca, Argentina, from June 13 to June 17, 1988 [Perillo and Lavelle, 1988]. The meeting sought to provide a timely impetus to further progress in sediment transport research in estuaries, promote communication among researchers using different investigatory approaches, and develop collaborations among estuarine scientists in developed and developing nations.

Sealed reticulocyte ghosts. An experimental model for the study of Fe2+ transport.

PubMed

Núñez, M T; Escobar, A; Ahumada, A; Gonzalez-Sepulveda, M

1992-06-05

Sealed right-side-out reticulocyte ghosts transported and accumulated iron offered as 59Fe(2+)-ascorbate (Km = 1.1 microM). The uptake of iron by ghosts presented the characteristics of a transporter-mediated process: it responded to osmotic challenge, the rate of transport increased when iron was present in the opposing side, and the transport rate showed the temperature dependence typical of membrane-mediated processes. The transport of iron was dependent on an associated influx of Cl- in order to keep electroneutrality. Other transition metals, such as Cu2+, Zn2+, and Co2+, inhibited the transport of Fe2+. The overall characteristics of the system make reticulocyte sealed ghosts a very useful model in determining the basic mechanisms of membrane iron transport.

Construction of sediment budgets for drainage basins

Treesearch

William E. Dietrich; Thomas Dunne; Neil F. Humphrey; Leslie M. Reid

1982-01-01

Abstract - A sediment budget for a drainage basin is a quantitative statement of the rates of production, transport, and discharge of detritus. To construct a sediment budget for a drainage basin, one must integrate the temporal and spatial variations of transport and storage processes. This requires: recognition and quantification of transport processes, recognition...

Logistics Control Facility: A Normative Model for Total Asset Visibility in the Air Force Logistics System

DTIC Science & Technology

1994-09-01

IIssue Computers, information systems, and communication systems are being increasingly used in transportation, warehousing, order processing , materials...inventory levels, reduced order processing times, reduced order processing costs, and increased customer satisfaction. While purchasing and transportation...process, the speed in which crders are processed would increase significantly. Lowering the order processing time in turn lowers the lead time, which in

Continuous Energy Photon Transport Implementation in MCATK

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, Terry R.; Trahan, Travis John; Sweezy, Jeremy Ed

2016-10-31

The Monte Carlo Application ToolKit (MCATK) code development team has implemented Monte Carlo photon transport into the MCATK software suite. The current particle transport capabilities in MCATK, which process the tracking and collision physics, have been extended to enable tracking of photons using the same continuous energy approximation. We describe the four photoatomic processes implemented, which are coherent scattering, incoherent scattering, pair-production, and photoelectric absorption. The accompanying background, implementation, and verification of these processes will be presented.

Pretreatment of coal during transport

DOEpatents

Johnson, Glenn E.; Neilson, Harry B.; Forney, Albert J.; Haynes, William P.

1977-04-19

Many available coals are "caking coals" which possess the undesirable characteristic of fusing into a solid mass when heated through their plastic temperature range (about 400.degree. C.) which temperature range is involved in many common treatment processes such as gasification, hydrogenation, carbonization and the like. Unless the caking properties are first destroyed, the coal cannot be satisfactorily used in such processes. A process is disclosed herein for decaking finely divided coal during its transport to the treating zone by propelling the coal entrained in an oyxgen-containing gas through a heated transport pipe whereby the separate transport and decaking steps of the prior art are combined into a single step.

Sediment transport processes in the Pearl River Estuary as revealed by grain-size end-member modeling and sediment trend analysis

NASA Astrophysics Data System (ADS)

Li, Tao; Li, Tuan-Jie

2018-04-01

The analysis of grain-size distribution enables us to decipher sediment transport processes and understand the causal relations between dynamic processes and grain-size distributions. In the present study, grain sizes were measured from surface sediments collected in the Pearl River Estuary and its adjacent coastal areas. End-member modeling analysis attempts to unmix the grain sizes into geologically meaningful populations. Six grain-size end-members were identified. Their dominant modes are 0 Φ, 1.5 Φ, 2.75 Φ, 4.5 Φ, 7 Φ, and 8 Φ, corresponding to coarse sand, medium sand, fine sand, very coarse silt, silt, and clay, respectively. The spatial distributions of the six end-members are influenced by sediment transport and depositional processes. The two coarsest end-members (coarse sand and medium sand) may reflect relict sediments deposited during the last glacial period. The fine sand end-member would be difficult to transport under fair weather conditions, and likely indicates storm deposits. The three remaining fine-grained end-members (very coarse silt, silt, and clay) are recognized as suspended particles transported by saltwater intrusion via the flood tidal current, the Guangdong Coastal Current, and riverine outflow. The grain-size trend analysis shows distinct transport patterns for the three fine-grained end-members. The landward transport of the very coarse silt end-member occurs in the eastern part of the estuary, the seaward transport of the silt end-member occurs in the western part, and the east-west transport of the clay end-member occurs in the coastal areas. The results show that grain-size end-member modeling analysis in combination with sediment trend analysis help to better understand sediment transport patterns and the associated transport mechanisms.

49 CFR 510.3 - Compulsory process, the service thereof, claims for confidential treatment, and terms of compliance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Compulsory process, the service thereof, claims... OF TRANSPORTATION INFORMATION GATHERING POWERS § 510.3 Compulsory process, the service thereof... description of the documents or things to be produced. (c) Service of the compulsory processes specified in...

Analysis of procurement processes and development of recommendations for intelligent transportation systems (ITS) procurements : final report.

DOT National Transportation Integrated Search

2007-09-01

Traditional state procurement processes are not well-suited to the procurement of Intelligent Transportation Systems (ITS). The objective of this study was to analyze Kentuckys existing procurement processes, identify strengths and weaknesses of e...

14 CFR 414.15 - Processing the initial application.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Processing the initial application. 414.15 Section 414.15 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING SAFETY APPROVALS Application Procedures § 414.15 Processing the...

Connections between transport in events and transport at landscape-structuring timescales

NASA Astrophysics Data System (ADS)

Harman, C. J.; Lohse, K. A.; Troch, P. A.; Sivapalan, M.

2012-12-01

Complex spatial and temporal variability can arise in the critical zone when feedbacks occur at multiple time scales between transported materials and the landscape and soils through which it is transported. This is clearly illustrated where geomorphic transport processes, soil development, and vegetation interact in semi-arid shrublands. Here we use soil and terrain data and a numerical model of overland flow on semi-arid hillslopes to show that microtopography can generate spatial variations in the dominance of transport processes operating at different timescales, with consequences for the direction of resource redistribution between functional units within these ecosystems. Conceptual and numerical models of the redistribution of mineral, organic and water have mostly been developed on low-gradient alluvial fans and pediments. These have focused on the fluvial transport of resources from the inter-spaces between shrub canopies to the areas below the canopy in those few storm events that generate significant run-off. These processes are believed to produce a mosaic of resource islands in which biota are concentrated. We investigated the spatial distribution of soil properties (including organic matter and soil hydraulic properties), vegetation, and microtopography on two steeper hillslopes of contrasting lithology (one granite, one schist) in the Sonoran desert foothills of the Catalina Mountains. Three hypotheses were developed through iteration between fieldwork and data analysis. These tested whether there were significant differences in soil composition and hydraulic properties below- and between-canopy, whether the surface soil organic matter was directly associated with above-ground biomass, and whether soil organic matter distributions measured along transects below shrubs showed downslope asymmetries indicative of the processes that create them. Data from these sites were used in a numerical model to investigate how these structures could be related to the population of runoff events and processes that generate them. The results suggest that over the long term, slope-dependent transport processes (such as rainsplash, bioturbation and trampling) seem to play an important role in these steeper hillslopes in inverting the flow of resources. Over many storm and inter-storm periods, soil organic matter is transported downslope in plumes extending at least two canopy radii downslope from below woody-shrub canopies into the inter-space. This pattern was particularly evident where microtopography and soil properties create micro-sites protected from fluvial transport. While many of the patterns observed are similar to those from more stable geomorphic surfaces, the results suggest that long-term downslope transport processes in sloping terrain can disrupt the autogenic processes that reinforce the redistribution of resources under shrubs. This result has important implications for our understanding of the relationship between ecosystem function and landscape-scale transport in these environments.

Wellbore manufacturing processes for in situ heat treatment processes

DOEpatents

Davidson, Ian Alexander; Geddes, Cameron James; Rudolf, Randall Lynn; Selby, Bruce Allen; MacDonald, Duncan Charles

2012-12-11

A method includes making coiled tubing at a coiled tubing manufacturing unit coupled to a coiled tubing transportation system. One or more coiled tubing reels are transported from the coiled tubing manufacturing unit to one or more moveable well drilling systems using the coiled tubing transportation system. The coiled tubing transportation system runs from the tubing manufacturing unit to one or more movable well drilling systems, and then back to the coiled tubing manufacturing unit.

[Carbohydrate transport in the cestode Triaenophorus nodulosus].

PubMed

Izvekova, G I

1989-01-01

The data demonstrating the presence of the glucose active transport system in the cestode T. nodulosus are obtained. Kinetic characteristics of the transport are estimated and their dependence on the incubation temperature are shown. Heterogeneity of the worm body in respect to transport processes and their dependence on the physiological state of cestodes are discovered. The absorption of different forms of glucose is studied and the similarity of digestion processes in parasites and their hosts is shown.

Abrasion resistance of muscovite in aeolian and subaqueous transport experiments

NASA Astrophysics Data System (ADS)

Anderson, Calvin J.; Struble, Alexander; Whitmore, John H.

2017-02-01

Complementary aeolian and subaqueous transport experiments showed a trend in muscovite abrasion that may be useful for identifying ancient sandstones as aeolian or subaqueous in origin. We found that our experimental aeolian processes pulverized the micas quickly, while our subaqueous processes did not. In a pair of abrasion resistance experiments conducted with micaceous quartz sand, it was found that large muscovite grains were (1) reduced by aeolian processes to less than 500 μm in just 4 days, and (2) preserved by subaqueous processes to 610 ± 90 μm even after 356 days. At 20 days of aeolian transport no loose micas could be found even under the microscope, but after a year of subaqueous transport loose muscovite grains could still be seen with the naked eye. Thus, the occurrence and character of micas in a sandstone, particularly muscovite, may be helpful in determining the ancient depositional process.

Field-programmable lab-on-a-chip based on microelectrode dot array architecture.

PubMed

Wang, Gary; Teng, Daniel; Lai, Yi-Tse; Lu, Yi-Wen; Ho, Yingchieh; Lee, Chen-Yi

2014-09-01

The fundamentals of electrowetting-on-dielectric (EWOD) digital microfluidics are very strong: advantageous capability in the manipulation of fluids, small test volumes, precise dynamic control and detection, and microscale systems. These advantages are very important for future biochip developments, but the development of EWOD microfluidics has been hindered by the absence of: integrated detector technology, standard commercial components, on-chip sample preparation, standard manufacturing technology and end-to-end system integration. A field-programmable lab-on-a-chip (FPLOC) system based on microelectrode dot array (MEDA) architecture is presented in this research. The MEDA architecture proposes a standard EWOD microfluidic component called 'microelectrode cell', which can be dynamically configured into microfluidic components to perform microfluidic operations of the biochip. A proof-of-concept prototype FPLOC, containing a 30 × 30 MEDA, was developed by using generic integrated circuits computer aided design tools, and it was manufactured with standard low-voltage complementary metal-oxide-semiconductor technology, which allows smooth on-chip integration of microfluidics and microelectronics. By integrating 900 droplet detection circuits into microelectrode cells, the FPLOC has achieved large-scale integration of microfluidics and microelectronics. Compared to the full-custom and bottom-up design methods, the FPLOC provides hierarchical top-down design approach, field-programmability and dynamic manipulations of droplets for advanced microfluidic operations.

Power smart in-door optical wireless link design

NASA Astrophysics Data System (ADS)

Marraccini, P. J.; Riza, N. A.

2011-12-01

Presented for the first time, to the best of the authors´ knowledge, is the design of a power smart in-door optical wireless link that provides lossless beam propagation between Transmitter (T) and Receiver (R) for changing link distances. Each T/R unit uses a combination of fixed and variable focal length optics to smartly adjust the laser beam propagation parameters of minimum beam waist size and its location to produce the optimal zero propagation loss coupling condition at the R for that link distance. An Electronically Controlled Variable Focus Lens (ECVFL) is used to form the wide field-of-view search beam and change the beam size at R to form a low loss beam. The T/R unit can also deploy camera optics and thermal energy harvesting electronics to improve link operational smartness and efficiency. To demonstrate the principles of the beam conditioned low loss indoor link, a visible 633 nm laser link using an electro-wetting technology liquid ECVFL is demonstrated for a variable 1 to 4 m link range. Measurements indicate a 53% improvement over an unconditioned laser link at 4 m. Applications for this power efficient wireless link includes mobile computer platform communications and agile server rack interconnections in data centres.

Prediction of FAD binding sites in electron transport proteins according to efficient radial basis function networks and significant amino acid pairs.

PubMed

Le, Nguyen-Quoc-Khanh; Ou, Yu-Yen

2016-07-30

Cellular respiration is a catabolic pathway for producing adenosine triphosphate (ATP) and is the most efficient process through which cells harvest energy from consumed food. When cells undergo cellular respiration, they require a pathway to keep and transfer electrons (i.e., the electron transport chain). Due to oxidation-reduction reactions, the electron transport chain produces a transmembrane proton electrochemical gradient. In case protons flow back through this membrane, this mechanical energy is converted into chemical energy by ATP synthase. The convert process is involved in producing ATP which provides energy in a lot of cellular processes. In the electron transport chain process, flavin adenine dinucleotide (FAD) is one of the most vital molecules for carrying and transferring electrons. Therefore, predicting FAD binding sites in the electron transport chain is vital for helping biologists understand the electron transport chain process and energy production in cells. We used an independent data set to evaluate the performance of the proposed method, which had an accuracy of 69.84 %. We compared the performance of the proposed method in analyzing two newly discovered electron transport protein sequences with that of the general FAD binding predictor presented by Mishra and Raghava and determined that the accuracy of the proposed method improved by 9-45 % and its Matthew's correlation coefficient was 0.14-0.5. Furthermore, the proposed method enabled reducing the number of false positives significantly and can provide useful information for biologists. We developed a method that is based on PSSM profiles and SAAPs for identifying FAD binding sites in newly discovered electron transport protein sequences. This approach achieved a significant improvement after we added SAAPs to PSSM features to analyze FAD binding proteins in the electron transport chain. The proposed method can serve as an effective tool for predicting FAD binding sites in electron transport proteins and can help biologists understand the functions of the electron transport chain, particularly those of FAD binding sites. We also developed a web server which identifies FAD binding sites in electron transporters available for academics.

Molecular cloning and expressional analysis of five sucrose transporter (SUT) genes in sugarcane

USDA-ARS?s Scientific Manuscript database

The sucrose transport and accumulation in sugarcane internodes are very complicated processes and how sugarcane sucrose transporter (SUT) genes function in these processes remains unclear. In this study, five sugarcane SUT genes, namely, SoSUT1, SoSUT2, SoSUT3, SoSUT4 and SoSUT5, were cloned and the...

Production and cost of harvesting, processing, and transporting small-diameter (< 5 inches) trees for energy

Treesearch

Fei Pan; Han-Sup Han; Leonard R. Johnson; William J. Elliot

2008-01-01

Dense, small-diameter stands generally require thinning from below to improve fire-tolerance. The resulting forest biomass can be used for energy production. The cost of harvesting, processing, and transporting small-diameter trees often exceeds revenues due to high costs associated with harvesting and transportation and low market values for forest biomass....

30 CFR 291.112 - What process will MMS follow in rendering a decision on whether a grantee or transporter has...

Code of Federal Regulations, 2011 CFR

2011-07-01

... decision on whether a grantee or transporter has provided open and nondiscriminatory access? 291.112..., DEPARTMENT OF THE INTERIOR APPEALS OPEN AND NONDISCRIMINATORY ACCESS TO OIL AND GAS PIPELINES UNDER THE OUTER... grantee or transporter has provided open and nondiscriminatory access? MMS will begin processing a...

Gaining insights into interrill soil erosion processes using rare earth element tracers

USDA-ARS?s Scientific Manuscript database

Increasing interest in developing process-based erosion models requires better understanding of the relationships among soil detachment, transportation, and deposition. The objectives are to 1) identify the limiting process between soil detachment and sediment transport for interrill erosion, 2) und...

ATP-binding cassette-like transporters are involved in the transport of lignin precursors across plasma and vacuolar membranes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miao, Y.C.; Liu, C.

2010-12-28

Lignin is a complex biopolymer derived primarily from the condensation of three monomeric precursors, the monolignols. The synthesis of monolignols occurs in the cytoplasm. To reach the cell wall where they are oxidized and polymerized, they must be transported across the cell membrane. However, the molecular mechanisms underlying the transport process are unclear. There are conflicting views about whether the transport of these precursors occurs by passive diffusion or is an energized active process; further, we know little about what chemical forms are required. Using isolated plasma and vacuolar membrane vesicles prepared from Arabidopsis, together with applying different transporter inhibitorsmore » in the assays, we examined the uptake of monolignols and their derivatives by these native membrane vesicles. We demonstrate that the transport of lignin precursors across plasmalemma and their sequestration into vacuoles are ATP-dependent primary-transport processes, involving ATP-binding cassette-like transporters. Moreover, we show that both plasma and vacuolar membrane vesicles selectively transport different forms of lignin precursors. In the presence of ATP, the inverted plasma membrane vesicles preferentially take up monolignol aglycones, whereas the vacuolar vesicles are more specific for glucoconjugates, suggesting that the different ATP-binding cassette-like transporters recognize different chemical forms in conveying them to distinct sites, and that glucosylation of monolignols is necessary for their vacuolar storage but not required for direct transport into the cell wall in Arabidopsis.« less

Crew Transportation Operations Standards

NASA Technical Reports Server (NTRS)

Mango, Edward J.; Pearson, Don J. (Compiler)

2013-01-01

The Crew Transportation Operations Standards contains descriptions of ground and flight operations processes and specifications and the criteria which will be used to evaluate the acceptability of Commercial Providers' proposed processes and specifications.

Safety Hazards During Intrahospital Transport: A Prospective Observational Study.

PubMed

Bergman, Lina M; Pettersson, Monica E; Chaboyer, Wendy P; Carlström, Eric D; Ringdal, Mona L

2017-10-01

To identify, classify, and describe safety hazards during the process of intrahospital transport of critically ill patients. A prospective observational study. Data from participant observations of the intrahospital transport process were collected over a period of 3 months. The study was undertaken at two ICUs in one university hospital. Critically ill patients transported within the hospital by critical care nurses, unlicensed nurses, and physicians. None. Content analysis was performed using deductive and inductive approaches. We detected a total of 365 safety hazards (median, 7; interquartile range, 4-10) during 51 intrahospital transports of critically ill patients, 80% of whom were mechanically ventilated. The majority of detected safety hazards were assessed as increasing the risk of harm, compromising patient safety (n = 204). Using the System Engineering Initiative for Patient Safety, we identified safety hazards related to the work system, as follows: team (n = 61), tasks (n = 83), tools and technologies (n = 124), environment (n = 48), and organization (n = 49). Inductive analysis provided an in-depth description of those safety hazards, contributing factors, and process-related outcomes. Findings suggest that intrahospital transport is a hazardous process for critically ill patients. We have identified several factors that may contribute to transport-related adverse events, which will provide the opportunity for the redesign of systems to enhance patient safety.

Impact of peculiar features of construction of transport infrastructure on the choice of tools for reengineering of business processes

NASA Astrophysics Data System (ADS)

Khripko, Elena

2017-10-01

In the present article we study the issues of organizational resistance to reengineering of business processes in construction of transport infrastructure. Reengineering in a company of transport sector is, first and foremost, an innovative component of business strategy. We analyze the choice of forward and reverse reengineering tools and terms of their application in connection with organizational resistance. Reengineering is defined taking into account four aspects: fundamentality, radicality, abruptness, business process. We describe the stages of reengineering and analyze key requirements to newly created business processes.

Future changes in large-scale transport and stratosphere-troposphere exchange

NASA Astrophysics Data System (ADS)

Abalos, M.; Randel, W. J.; Kinnison, D. E.; Garcia, R. R.

2017-12-01

Future changes in large-scale transport are investigated in long-term (1955-2099) simulations of the Community Earth System Model - Whole Atmosphere Community Climate Model (CESM-WACCM) under an RCP6.0 climate change scenario. We examine artificial passive tracers in order to isolate transport changes from future changes in emissions and chemical processes. The model suggests enhanced stratosphere-troposphere exchange in both directions (STE), with decreasing tropospheric and increasing stratospheric tracer concentrations in the troposphere. Changes in the different transport processes are evaluated using the Transformed Eulerian Mean continuity equation, including parameterized convective transport. Dynamical changes associated with the rise of the tropopause height are shown to play a crucial role on future transport trends.

Structure and formation of ant transportation networks

PubMed Central

Latty, Tanya; Ramsch, Kai; Ito, Kentaro; Nakagaki, Toshiyuki; Sumpter, David J. T.; Middendorf, Martin; Beekman, Madeleine

2011-01-01

Many biological systems use extensive networks for the transport of resources and information. Ants are no exception. How do biological systems achieve efficient transportation networks in the absence of centralized control and without global knowledge of the environment? Here, we address this question by studying the formation and properties of inter-nest transportation networks in the Argentine ant (Linepithema humile). We find that the formation of inter-nest networks depends on the number of ants involved in the construction process. When the number of ants is sufficient and networks do form, they tend to have short total length but a low level of robustness. These networks are topologically similar to either minimum spanning trees or Steiner networks. The process of network formation involves an initial construction of multiple links followed by a pruning process that reduces the number of trails. Our study thus illuminates the conditions under and the process by which minimal biological transport networks can be constructed. PMID:21288958

Correlated receptor transport processes buffer single-cell heterogeneity

PubMed Central

Kallenberger, Stefan M.; Unger, Anne L.; Legewie, Stefan; Lymperopoulos, Konstantinos; Eils, Roland

2017-01-01

Cells typically vary in their response to extracellular ligands. Receptor transport processes modulate ligand-receptor induced signal transduction and impact the variability in cellular responses. Here, we quantitatively characterized cellular variability in erythropoietin receptor (EpoR) trafficking at the single-cell level based on live-cell imaging and mathematical modeling. Using ensembles of single-cell mathematical models reduced parameter uncertainties and showed that rapid EpoR turnover, transport of internalized EpoR back to the plasma membrane, and degradation of Epo-EpoR complexes were essential for receptor trafficking. EpoR trafficking dynamics in adherent H838 lung cancer cells closely resembled the dynamics previously characterized by mathematical modeling in suspension cells, indicating that dynamic properties of the EpoR system are widely conserved. Receptor transport processes differed by one order of magnitude between individual cells. However, the concentration of activated Epo-EpoR complexes was less variable due to the correlated kinetics of opposing transport processes acting as a buffering system. PMID:28945754

Geomorphic process from topographic form: automating the interpretation of repeat survey data in river valleys

USGS Publications Warehouse

Kasprak, Alan; Caster, Joshua J.; Bangen, Sara G.; Sankey, Joel B.

2017-01-01

The ability to quantify the processes driving geomorphic change in river valley margins is vital to geomorphologists seeking to understand the relative role of transport mechanisms (e.g. fluvial, aeolian, and hillslope processes) in landscape dynamics. High-resolution, repeat topographic data are becoming readily available to geomorphologists. By contrasting digital elevation models derived from repeat surveys, the transport processes driving topographic changes can be inferred, a method termed ‘mechanistic segregation.’ Unfortunately, mechanistic segregation largely relies on subjective and time consuming manual classification, which has implications both for its reproducibility and the practical scale of its application. Here we present a novel computational workflow for the mechanistic segregation of geomorphic transport processes in geospatial datasets. We apply the workflow to seven sites along the Colorado River in the Grand Canyon, where geomorphic transport is driven by a diverse suite of mechanisms. The workflow performs well when compared to field observations, with an overall predictive accuracy of 84% across 113 validation points. The approach most accurately predicts changes due to fluvial processes (100% accuracy) and aeolian processes (96%), with reduced accuracy in predictions of alluvial and colluvial processes (64% and 73%, respectively). Our workflow is designed to be applicable to a diversity of river systems and will likely provide a rapid and objective understanding of the processes driving geomorphic change at the reach and network scales. We anticipate that such an understanding will allow insight into the response of geomorphic transport processes to external forcings, such as shifts in climate, land use, or river regulation, with implications for process-based river management and restoration.

Constructability issues on KyTC projects.

DOT National Transportation Integrated Search

2003-07-01

A successful constructibility review process for a transportation agency must follow an established methodology similar to value engineering. The process must be flexible and address the critical issues impacting transportation construction projects,...

Prey transport kinematics in Tupinambis teguixin and Varanus exanthematicus: conservation of feeding behavior in 'chemosensory-tongued' lizards.

PubMed

Elias, J A; McBrayer, L D; Reilly, S M

2000-02-01

Although lizards have been predicted to show extensive intraoral prey-processing behaviors, quantitative analyses of the types of prey-processing behavior they demonstrate and of their kinematics have been limited. The more basal lizard lineages (Iguanians) have undergone some study, but the prey-processing repertoires of crown taxa have not been thoroughly examined and quantitative comparisons of behaviors within or among species have not been made. In this study, the prey transport behavior of the savannah monitor (Varanus exanthematicus) and gold tegu (Tupinambis teguixin) are described. Although these two lineages have independently evolved tongues that are highly specialized for chemoreception, we found that they share the same three distinct types of transport behavior. These behavior patterns are (i) a purely inertial transport, (ii) an inertial transport with use of the tongue, and (iii) a non-inertial lingual transport. The tongue is used extensively in both the inertial and the purely lingual transport behaviors. More than 75 % of all transport behaviors involved tongue movements. These species appear to exhibit a conservation of feeding kinematics compared with patterns known for basal lizards. A hypothesis for the evolution of inertial feeding is proposed.

49 CFR 564.5 - Information filing; agency processing of filings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Information filing; agency processing of filings... HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION REPLACEABLE LIGHT SOURCE INFORMATION (Eff. until 12-01-12) § 564.5 Information filing; agency processing of filings. (a) Each manufacturer...

Improving the Transportation Planning Process in Small Cities : Volumes 1-3.

DOT National Transportation Integrated Search

1973-11-01

An advance in the state-of-the-art of municipal transportation planning is described. A planning process that fully considers community value and land use was designed by and for the City of Cambridge with the expectation that such a process could al...

A methodology to evaluate unplanned proposed transportation projects.

DOT National Transportation Integrated Search

2008-01-01

The Virginia Department of Transportation may be asked to consider proposed transportation projects that have not originated within the transportation planning process. Examples include offers by the private sector to build infrastructure in exchange...

Conditions and processes affecting radionuclide transport

USGS Publications Warehouse

Simmons, Ardyth M.; Neymark, Leonid A.

2012-01-01

Understanding of unsaturated-zone transport is based on laboratory and field-scale experiments. Fractures provide advective transport pathways. Sorption and matrix diffusion may contribute to retardation of radionuclides. Conversely, sorption onto mobile colloids may enhance radionuclide transport.

2011 and 2012 Early Careers Achievement Awards: farm and pig factors affecting welfare during the marketing process.

PubMed

Johnson, A K; Gesing, L M; Ellis, M; McGlone, J J; Berg, E; Lonergan, S M; Fitzgerald, R; Karriker, L A; Ramirez, A; Stalder, K J; Sapkota, A; Kephart, R; Selsby, J T; Sadler, L J; Ritter, M J

2013-06-01

The objective of this paper is to review the scientific literature to identify on-farm factors that contribute to market weight pig transportation losses. Transportation of market weight pigs is an essential element to the multisite pork production model used in the United States. In 2011 alone, approximately 111 million market weight pigs were transported from the finishing site to the abattoir. For pigs, the marketing process can present a combination of potentially novel, physical, and/or unfamiliar experiences that can be stressful. If the pig cannot cope with these sequential and additive stressors, then an increased rate of transportation losses could occur with a detrimental effect on pork carcass value. Current yearly estimates for transport losses are 1 million pigs (1%). A variety of market weight pig and farm factors have been reported to detrimentally affect transportation losses. By understanding how pigs interact with their environment during marketing, researchers, producers, and personnel at the abattoir may begin to identify, prioritize, and attempt to minimize or eliminate these stressors. This process will ultimately decrease transportation losses, improve pork quality, and increase profitability.

Charge transport model in nanodielectric composites based on quantum tunneling mechanism and dual-level traps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Guochang; Chen, George, E-mail: gc@ecs.soton.ac.uk, E-mail: sli@mail.xjtu.edu.cn; School of Electronic and Computer Science, University of Southampton, Southampton SO17 1BJ

Charge transport properties in nanodielectrics present different tendencies for different loading concentrations. The exact mechanisms that are responsible for charge transport in nanodielectrics are not detailed, especially for high loading concentration. A charge transport model in nanodielectrics has been proposed based on quantum tunneling mechanism and dual-level traps. In the model, the thermally assisted hopping (TAH) process for the shallow traps and the tunnelling process for the deep traps are considered. For different loading concentrations, the dominant charge transport mechanisms are different. The quantum tunneling mechanism plays a major role in determining the charge conduction in nanodielectrics with high loadingmore » concentrations. While for low loading concentrations, the thermal hopping mechanism will dominate the charge conduction process. The model can explain the observed conductivity property in nanodielectrics with different loading concentrations.« less

A systematic collaborative process for assessing launch vehicle propulsion technologies

NASA Astrophysics Data System (ADS)

Odom, Pat R.

1999-01-01

A systematic, collaborative process for prioritizing candidate investments in space transportation systems technologies has been developed for the NASA Space Transportation Programs Office. The purpose of the process is to provide a repeatable and auditable basis for selecting technology investments to enable achievement of NASA's strategic space transportation objectives. The paper describes the current multilevel process and supporting software tool that has been developed. Technologies are prioritized across system applications to produce integrated portfolios for recommended funding. An example application of the process to the assessment of launch vehicle propulsion technologies is described and illustrated. The methodologies discussed in the paper are expected to help NASA and industry ensure maximum returns from technology investments under constrained budgets.

Spatial Data from Transportation Studies and Surveys | Transportation

Science.gov Websites

transportation studies and surveys, submit an application for approval to connect to a restricted secure portal environment. For a list of studies and surveys, see cleansed data. Application Process For accessing spatial data, learn about the application and approval process. If you'd like to apply to access the spatial

Including health in transport policy agendas: the role of health impact assessment analyses and procedures in the European experience.

PubMed Central

Dora, Carlos; Racioppi, Francesca

2003-01-01

From the mid-1990s, research began to highlight the importance of a wide range of health impacts of transport policy decisions. The Third Ministerial Conference on Environment and Health adopted a Charter on Transport, Environment and Health based on four main components: bringing awareness of the nature, magnitude and costs of the health impacts of transport into intergovernmental processes; strengthening the arguments for integration of health into transport policies by developing in-depth analysis of the evidence; developing national case studies; and engaging ministries of environment, health and transport as well as intergovernmental and nongovernmental organizations. Negotiation of the Charter was based on two converging processes: the political process involved the interaction of stakeholders in transport, health and environment in Europe, which helped to frame the issues and the approaches to respond to them; the scientific process involved an international group of experts who produced state-of- the-art reviews of the health impacts resulting from transportation activities, identifying gaps in existing knowledge and methodological tools, specifying the policy implications of their findings, and suggesting possible targets for health improvements. Health arguments were used to strengthen environmental ones, clarify costs and benefits, and raise issues of health equity. The European experience shows that HIA can fulfil the need for simple procedures to be systematically applied to decisions regarding transport strategies at national, regional and local levels. Gaps were identified concerning models for quantifying health impacts and capacity building on how to use such tools. PMID:12894322

The ESCRT regulator Did2 maintains the balance between long-distance endosomal transport and endocytic trafficking

PubMed Central

Haag, Carl

2017-01-01

In highly polarised cells, like fungal hyphae, early endosomes function in both endocytosis as well as long-distance transport of various cargo including mRNA and protein complexes. However, knowledge on the crosstalk between these seemingly different trafficking processes is scarce. Here, we demonstrate that the ESCRT regulator Did2 coordinates endosomal transport in fungal hyphae of Ustilago maydis. Loss of Did2 results in defective vacuolar targeting, less processive long-distance transport and abnormal shuttling of early endosomes. Importantly, the late endosomal protein Rab7 and vacuolar protease Prc1 exhibit increased shuttling on these aberrant endosomes suggesting defects in endosomal maturation and identity. Consistently, molecular motors fail to attach efficiently explaining the disturbed processive movement. Furthermore, the endosomal mRNP linker protein Upa1 is hardly present on endosomes resulting in defects in long-distance mRNA transport. In conclusion, the ESCRT regulator Did2 coordinates precise maturation of endosomes and thus provides the correct membrane identity for efficient endosomal long-distance transport. PMID:28422978

Insight into sediment transport processes on saline rangeland hillslopes using three-dimensional soil microtopography changes

USDA-ARS?s Scientific Manuscript database

In arid and semi-arid rangeland environments, an accurate understanding of runoff generation and sediment transport processes is key to developing effective management actions and addressing ecosystem response to changes. Yet, many primary processes (namely sheet and splash and concentrated flow ero...

46 CFR 515.24 - Agent for service of process.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 9 2014-10-01 2014-10-01 false Agent for service of process. 515.24 Section 515.24..., FINANCIAL RESPONSIBILITY REQUIREMENTS, AND GENERAL DUTIES FOR OCEAN TRANSPORTATION INTERMEDIARIES Financial... process. (a) Every ocean transportation intermediary not located in the United States and every group or...

46 CFR 515.24 - Agent for service of process.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 9 2011-10-01 2011-10-01 false Agent for service of process. 515.24 Section 515.24..., FINANCIAL RESPONSIBILITY REQUIREMENTS, AND GENERAL DUTIES FOR OCEAN TRANSPORTATION INTERMEDIARIES Financial... process. (a) Every ocean transportation intermediary not located in the United States and every group or...

46 CFR 515.24 - Agent for service of process.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 9 2012-10-01 2012-10-01 false Agent for service of process. 515.24 Section 515.24..., FINANCIAL RESPONSIBILITY REQUIREMENTS, AND GENERAL DUTIES FOR OCEAN TRANSPORTATION INTERMEDIARIES Financial... process. (a) Every ocean transportation intermediary not located in the United States and every group or...

46 CFR 515.24 - Agent for service of process.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 9 2013-10-01 2013-10-01 false Agent for service of process. 515.24 Section 515.24..., FINANCIAL RESPONSIBILITY REQUIREMENTS, AND GENERAL DUTIES FOR OCEAN TRANSPORTATION INTERMEDIARIES Financial... process. (a) Every ocean transportation intermediary not located in the United States and every group or...

Signal processing of bedload transport impact amplitudes on accelerometer instrumented plates

USDA-ARS?s Scientific Manuscript database

This work was performed to help establish a data processing methodology for relating accelerometer signals caused by impacts of gravel on steel plates to the mass and size of the transported material. Signal processing was performed on impact plate data collected in flume experiments at the Nationa...

Integrating climate change into the transportation planning process : final report

DOT National Transportation Integrated Search

2008-07-01

The objective of this study is to advance the practice and application of transportation planning among state, regional, and local transportation planning agencies to successfully meet growing concerns about the relationship between transportation an...

Transportation asset management : a vehicle for mainstreaming ITS?

DOT National Transportation Integrated Search

2001-06-01

This paper examines the use of transportation asset management (TAM) as a mechanism for mainstreaming" intelligent transportation systems (ITS) into the transportation decision-making process. TAM is an emerging set of tools and techniques that compr...

23 CFR 940.3 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION INTELLIGENT TRANSPORTATION SYSTEMS INTELLIGENT TRANSPORTATION SYSTEM ARCHITECTURE AND STANDARDS § 940.3 Definitions. Intelligent Transportation System (ITS... projects or groups of projects. Systems engineering is a structured process for arriving at a final design...

23 CFR 940.3 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

... HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION INTELLIGENT TRANSPORTATION SYSTEMS INTELLIGENT TRANSPORTATION SYSTEM ARCHITECTURE AND STANDARDS § 940.3 Definitions. Intelligent Transportation System (ITS... projects or groups of projects. Systems engineering is a structured process for arriving at a final design...

23 CFR 940.3 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-04-01

... HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION INTELLIGENT TRANSPORTATION SYSTEMS INTELLIGENT TRANSPORTATION SYSTEM ARCHITECTURE AND STANDARDS § 940.3 Definitions. Intelligent Transportation System (ITS... projects or groups of projects. Systems engineering is a structured process for arriving at a final design...

Transportation in African Development.

ERIC Educational Resources Information Center

Altschul, Robert D.

1980-01-01

Examines the structure, role, and needs of Africa's national and intracontinental transportation system. Characteristics of rail, water, road, and air transportation are examined. The conclusion is that high investment in transportation systems is essential to the development process. (Author/KC)

Sugar and Glycerol Transport in Saccharomyces cerevisiae.

PubMed

Bisson, Linda F; Fan, Qingwen; Walker, Gordon A

2016-01-01

In Saccharomyces cerevisiae the process of transport of sugar substrates into the cell comprises a complex network of transporters and interacting regulatory mechanisms. Members of the large family of hexose (HXT) transporters display uptake efficiencies consistent with their environmental expression and play physiological roles in addition to feeding the glycolytic pathway. Multiple glucose-inducing and glucose-independent mechanisms serve to regulate expression of the sugar transporters in yeast assuring that expression levels and transporter activity are coordinated with cellular metabolism and energy needs. The expression of sugar transport activity is modulated by other nutritional and environmental factors that may override glucose-generated signals. Transporter expression and activity is regulated transcriptionally, post-transcriptionally and post-translationally. Recent studies have expanded upon this suite of regulatory mechanisms to include transcriptional expression fine tuning mediated by antisense RNA and prion-based regulation of transcription. Much remains to be learned about cell biology from the continued analysis of this dynamic process of substrate acquisition.

Microbiological status of broiler respiratory tracts before and during catching for transport to the processing plant

USDA-ARS?s Scientific Manuscript database

A significant point of entry for Salmonella into a processing plant is within the broilers to be processed. Prior to transport to the processing plant, feed (4 h) and water are withdrawn from the broilers on the farm before they are caught and cooped. During catching, an increased presence of dust i...

Implementation of polarization processes in a charge transport model applied on poly(ethylene naphthalate) films

NASA Astrophysics Data System (ADS)

Hoang, M.-Q.; Le Roy, S.; Boudou, L.; Teyssedre, G.

2016-06-01

One of the difficulties in unravelling transport processes in electrically insulating materials is the fact that the response, notably charging current transients, can have mixed contributions from orientation polarization and from space charge processes. This work aims at identifying and characterizing the polarization processes in a polar polymer in the time and frequency-domains and to implement the contribution of the polarization into a charge transport model. To do so, Alternate Polarization Current (APC) and Dielectric Spectroscopy measurements have been performed on poly(ethylene naphthalene 2,6-dicarboxylate) (PEN), an aromatic polar polymer, providing information on polarization mechanisms in the time- and frequency-domain, respectively. In the frequency-domain, PEN exhibits 3 relaxation processes termed β, β* (sub-glass transitions), and α relaxations (glass transition) in increasing order of temperature. Conduction was also detected at high temperatures. Dielectric responses were treated using a simplified version of the Havriliak-Negami model (Cole-Cole (CC) model), using 3 parameters per relaxation process, these parameters being temperature dependent. The time dependent polarization obtained from the CC model is then added to a charge transport model. Simulated currents issued from the transport model implemented with the polarization are compared with the measured APCs, showing a good consistency between experiments and simulations in a situation where the response comes essentially from dipolar processes.

Parallel-Batch Scheduling and Transportation Coordination with Waiting Time Constraint

PubMed Central

Gong, Hua; Chen, Daheng; Xu, Ke

2014-01-01

This paper addresses a parallel-batch scheduling problem that incorporates transportation of raw materials or semifinished products before processing with waiting time constraint. The orders located at the different suppliers are transported by some vehicles to a manufacturing facility for further processing. One vehicle can load only one order in one shipment. Each order arriving at the facility must be processed in the limited waiting time. The orders are processed in batches on a parallel-batch machine, where a batch contains several orders and the processing time of the batch is the largest processing time of the orders in it. The goal is to find a schedule to minimize the sum of the total flow time and the production cost. We prove that the general problem is NP-hard in the strong sense. We also demonstrate that the problem with equal processing times on the machine is NP-hard. Furthermore, a dynamic programming algorithm in pseudopolynomial time is provided to prove its ordinarily NP-hardness. An optimal algorithm in polynomial time is presented to solve a special case with equal processing times and equal transportation times for each order. PMID:24883385

Calcium sensitivity of dicarboxylate transport in cultured proximal tubule cells

PubMed Central

Schiro, Faith R.; Pajor, Ana M.; Hamm, L. Lee

2011-01-01

Urinary citrate is an important inhibitor of calcium nephrolithiasis and is primarily determined by proximal tubule reabsorption. The major transporter to reabsorb citrate is Na+-dicarboxylate cotransporter (NaDC1), which transports dicarboxylates, including the divalent form of citrate. We previously found that opossum kidney (OK) proximal tubule cells variably express either divalent or trivalent citrate transport, depending on extracellular calcium. The present studies were performed to delineate the mechanism of the effect of calcium on citrate and succinate transport in these cells. Transport was measured using isotope uptake assays. In some studies, NaDC1 transport was studied in Xenopus oocytes, expressing either the rabbit or opossum ortholog. In the OK cell culture model, lowering extracellular calcium increased both citrate and succinate transport by more than twofold; the effect was specific in that glucose transport was not altered. Citrate and succinate were found to reciprocally inhibit transport at low extracellular calcium (<60 μM), but not at normal calcium (1.2 mM); this mutual inhibition is consistent with dicarboxylate transport. The inhibition varied progressively at intermediate levels of extracellular calcium. In addition to changing the relative magnitude and interaction of citrate and succinate transport, decreasing calcium also increased the affinity of the transport process for various other dicarboxylates. Also, the affinity for succinate, at low concentrations of substrate, was increased by calcium removal. In contrast, in oocytes expressing NaDC1, calcium did not have a similar effect on transport, indicating that NaDC1 could not likely account for the findings in OK cells. In summary, extracellular calcium regulates constitutive citrate and succinate transport in OK proximal tubule cells, probably via a novel transport process that is not NaDC1. The calcium effect on citrate transport parallels in vivo studies that demonstrate the regulation of urinary citrate excretion with urinary calcium excretion, a process that may be important in decreasing urinary calcium stone formation. PMID:21123491

Virtual laboratory for the study of transport processes in surface waterflows

NASA Astrophysics Data System (ADS)

Aguilar, C.; Egüen, M.; Contreras, E.; Polo, M. J.

2012-04-01

The equations involved in the study of transport processes depend on the spatial and temporal scale of the study and according to the required level of detail can become very difficult to solve analytically. Besides, experimentation of processes with any transport phenomena involved is complex due to their natural or forced occurrence in the environment (eg. Rainfall-runoff, sediment yield, controlled and uncontrolled pollutant loadings, etc.) and the great diversity of substances and components with an specific chemical behavior. However, due to the numerous fields of application of transport phenomena (basic and applied research, hydrology and associated fluxes, sediment transport, pollutant loadings to water flows, industrial processes, soil and water quality, atmospheric emissions, legislation, etc.), realistic studies of transport processes are required. In this context, case study application, an active methodology according to the structural implications of the European Higher Education Area (EHEA), with the aid of computer tools constitute an interactive, instantaneous and flexible method with a new interplay between students and lecturers. Case studies allow the lecturer to design significant activities that generate knowledge in the students and motivates them to look for information, discuss, and be autonomous. This work presents the development of a graphical interface for the solution of different case studies for the acquisition of capacities and abilities in the autonomous apprenticeship of courses related to transport processes in Environmental Hydraulics. The interactive tool helps to develop and improve abilities in mixing and transport in surface water related courses. Thus, students clarify theoretical concepts and visualize processes with negative effects for the environment and that therefore, can only be reproduced in the laboratory or in the field under very controlled conditions and commonly with tracers instead of the real substances. The tool can be used for different case studies in terms of processes involved, governing variable, initial conditions, etc. (eg. Accidental spill of a conservative pollutant from a factory in a river stretch that constitutes a source of drinking water for a town downstream) and can be used as a virtual laboratory for the analysis of the influence of the different variables and parameters of the process. Thus, autonomous apprenticeship is fostered and therefore, the development of personal abilities and the analysis and summary of information related to the case study is stimulated.

A Process-Based Transport-Distance Model of Aeolian Transport

NASA Astrophysics Data System (ADS)

Naylor, A. K.; Okin, G.; Wainwright, J.; Parsons, A. J.

2017-12-01

We present a new approach to modeling aeolian transport based on transport distance. Particle fluxes are based on statistical probabilities of particle detachment and distributions of transport lengths, which are functions of particle size classes. A computational saltation model is used to simulate transport distances over a variety of sizes. These are fit to an exponential distribution, which has the advantages of computational economy, concordance with current field measurements, and a meaningful relationship to theoretical assumptions about mean and median particle transport distance. This novel approach includes particle-particle interactions, which are important for sustaining aeolian transport and dust emission. Results from this model are compared with results from both bulk- and particle-sized-specific transport equations as well as empirical wind tunnel studies. The transport-distance approach has been successfully used for hydraulic processes, and extending this methodology from hydraulic to aeolian transport opens up the possibility of modeling joint transport by wind and water using consistent physics. Particularly in nutrient-limited environments, modeling the joint action of aeolian and hydraulic transport is essential for understanding the spatial distribution of biomass across landscapes and how it responds to climatic variability and change.

32 CFR 1657.6 - Transportation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Transportation. 1657.6 Section 1657.6 National... PROCESSING § 1657.6 Transportation. (a) The Director shall furnish transportation for an overseas registrant... transportation from the place he reported for induction to the place to which his order to report for induction...

32 CFR 1657.6 - Transportation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 6 2011-07-01 2011-07-01 false Transportation. 1657.6 Section 1657.6 National... PROCESSING § 1657.6 Transportation. (a) The Director shall furnish transportation for an overseas registrant... transportation from the place he reported for induction to the place to which his order to report for induction...

32 CFR 1657.6 - Transportation.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 6 2013-07-01 2013-07-01 false Transportation. 1657.6 Section 1657.6 National... PROCESSING § 1657.6 Transportation. (a) The Director shall furnish transportation for an overseas registrant... transportation from the place he reported for induction to the place to which his order to report for induction...

32 CFR 1657.6 - Transportation.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 6 2014-07-01 2014-07-01 false Transportation. 1657.6 Section 1657.6 National... PROCESSING § 1657.6 Transportation. (a) The Director shall furnish transportation for an overseas registrant... transportation from the place he reported for induction to the place to which his order to report for induction...

32 CFR 1657.6 - Transportation.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 6 2012-07-01 2012-07-01 false Transportation. 1657.6 Section 1657.6 National... PROCESSING § 1657.6 Transportation. (a) The Director shall furnish transportation for an overseas registrant... transportation from the place he reported for induction to the place to which his order to report for induction...

Managing the TDM process : developing MPO institutional capacity - technical report.

DOT National Transportation Integrated Search

2015-04-01

Within Texas, the development of urban travel demand models (TDMs) is a cooperative process between the : Texas Department of Transportation and Metropolitan Planning Organizations (MPOs). Though TxDOT-Transportation Planning and Programming Division...

Statewide and Metropolitan Transportation Planning Processes : a TPCB Peer Exchange

DOT National Transportation Integrated Search

2016-04-20

This report highlights key recommendations and noteworthy practices identified at Statewide and Metropolitan Transportation Planning Processes Peer Exchange held on September 9-10, 2015 in Shepherdstown, West Virginia. This event was sponsored ...

Stark County Area Transportation Study - Transportation Improvement Program 1997-2000

DOT National Transportation Integrated Search

1996-05-01

The Transportation Improvement Program (TIP) is the schedule of highway and transit improvements recommended for implementation within the next four years. It is, therefore, the end product of the transportation planning process. The TIP originates f...

Littoral transport rates in the Santa Barbara Littoral Cell: a process-based model analysis

USGS Publications Warehouse

Elias, E. P. L.; Barnard, Patrick L.; Brocatus, John

2009-01-01

Identification of the sediment transport patterns and pathways is essential for sustainable coastal zone management of the heavily modified coastline of Santa Barbara and Ventura County (California, USA). A process-based model application, based on Delft3D Online Morphology, is used to investigate the littoral transport potential along the Santa Barbara Littoral Cell (between Point Conception and Mugu Canyon). An advanced optimalization procedure is applied to enable annual sediment transport computations by reducing the ocean wave climate in 10 wave height - direction classes. Modeled littoral transport rates compare well with observed dredging volumes, and erosion or sedimentation hotspots coincide with the modeled divergence and convergence of the transport gradients. Sediment transport rates are strongly dependent on the alongshore variation in wave height due to wave sheltering, diffraction and focusing by the Northern Channel Islands, and the local orientation of the geologically-controlled coastline. Local transport gradients exceed the net eastward littoral transport, and are considered a primary driver for hot-spot erosion.

Column Testing and 1D Reactive Transport Modeling to Evaluate Uranium Plume Persistence Processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Raymond H.; Morrison, Stan; Morris, Sarah

Motivation for Study: Natural flushing of contaminants at various U.S. Department of Energy Office of Legacy Management sites is not proceeding as quickly as predicted (plume persistence) Objectives: Help determine natural flushing rates using column tests. Use 1D reactive transport modeling to better understand the major processes that are creating plume persistence Approach: Core samples from under a former mill tailings area Tailings have been removed. Column leaching using lab-prepared water similar to nearby Gunnison River water. 1D reactive transport modeling to evaluate processes

Observable quantities for electrodiffusion processes in membranes.

PubMed

Garrido, Javier

2008-03-13

Electrically driven ion transport processes in a membrane system are analyzed in terms of observable quantities, such as the apparent volume flow, the time dependence of the electrolyte concentration in one cell compartment, and the electrical potential difference between the electrodes. The relations between the fluxes and these observable quantities are rigorously deduced from balances for constituent mass and solution volume. These relations improve the results for the transport coefficients up to 25% with respect to those obtained using simplified expressions common in the literature. Given the practical importance of ionic transport numbers and the solvent transference number in the phenomenological description of electrically driven processes, the transport equations are presented using the electrolyte concentration difference and the electric current as the drivers of the different constituents. Because various electric potential differences can be used in this traditional irreversible thermodynamics approach, the advantages of the formulation of the transport equations in terms of concentration difference and electric current are emphasized.

Reactive Transport in a Pipe in Soluble Rock: a Theoretical and Experimental Study

NASA Astrophysics Data System (ADS)

Li, W.; Opolot, M.; Sousa, R.; Einstein, H. H.

2015-12-01

Reactive transport processes within the dominant underground flow pathways such as fractures can lead to the widening or narrowing of rock fractures, potentially altering the flow and transport processes in the fractures. A flow-through experiment was designed to study the reactive transport process in a pipe in soluble rock to serve as a simplified representation of a fracture in soluble rock. Assumptions were made to formulate the problem as three coupled, one-dimensional partial differential equations: one for the flow, one for the transport and one for the radius change due to dissolution. Analytical and numerical solutions were developed to predict the effluent concentration and the change in pipe radius. The positive feedback of the radius increase is captured by the experiment and the numerical model. A comparison between the experiment and the simulation results demonstrates the validity of the analytical and numerical models.

PHT3D-UZF: A reactive transport model for variably-saturated porous media

USGS Publications Warehouse

Wu, Ming Zhi; Post, Vincent E. A.; Salmon, S. Ursula; Morway, Eric D.; Prommer, H.

2016-01-01

A modified version of the MODFLOW/MT3DMS-based reactive transport model PHT3D was developed to extend current reactive transport capabilities to the variably-saturated component of the subsurface system and incorporate diffusive reactive transport of gaseous species. Referred to as PHT3D-UZF, this code incorporates flux terms calculated by MODFLOW's unsaturated-zone flow (UZF1) package. A volume-averaged approach similar to the method used in UZF-MT3DMS was adopted. The PHREEQC-based computation of chemical processes within PHT3D-UZF in combination with the analytical solution method of UZF1 allows for comprehensive reactive transport investigations (i.e., biogeochemical transformations) that jointly involve saturated and unsaturated zone processes. Intended for regional-scale applications, UZF1 simulates downward-only flux within the unsaturated zone. The model was tested by comparing simulation results with those of existing numerical models. The comparison was performed for several benchmark problems that cover a range of important hydrological and reactive transport processes. A 2D simulation scenario was defined to illustrate the geochemical evolution following dewatering in a sandy acid sulfate soil environment. Other potential applications include the simulation of biogeochemical processes in variably-saturated systems that track the transport and fate of agricultural pollutants, nutrients, natural and xenobiotic organic compounds and micropollutants such as pharmaceuticals, as well as the evolution of isotope patterns.

Scaling and scale invariance of conservation laws in Reynolds transport theorem framework

NASA Astrophysics Data System (ADS)

Haltas, Ismail; Ulusoy, Suleyman

2015-07-01

Scale invariance is the case where the solution of a physical process at a specified time-space scale can be linearly related to the solution of the processes at another time-space scale. Recent studies investigated the scale invariance conditions of hydrodynamic processes by applying the one-parameter Lie scaling transformations to the governing equations of the processes. Scale invariance of a physical process is usually achieved under certain conditions on the scaling ratios of the variables and parameters involved in the process. The foundational axioms of hydrodynamics are the conservation laws, namely, conservation of mass, conservation of linear momentum, and conservation of energy from continuum mechanics. They are formulated using the Reynolds transport theorem. Conventionally, Reynolds transport theorem formulates the conservation equations in integral form. Yet, differential form of the conservation equations can also be derived for an infinitesimal control volume. In the formulation of the governing equation of a process, one or more than one of the conservation laws and, some times, a constitutive relation are combined together. Differential forms of the conservation equations are used in the governing partial differential equation of the processes. Therefore, differential conservation equations constitute the fundamentals of the governing equations of the hydrodynamic processes. Applying the one-parameter Lie scaling transformation to the conservation laws in the Reynolds transport theorem framework instead of applying to the governing partial differential equations may lead to more fundamental conclusions on the scaling and scale invariance of the hydrodynamic processes. This study will investigate the scaling behavior and scale invariance conditions of the hydrodynamic processes by applying the one-parameter Lie scaling transformation to the conservation laws in the Reynolds transport theorem framework.

Superior Thermal Interface via Vertically Aligned Carbon Nanotubes Grown on Graphite Foils

DTIC Science & Technology

2012-01-01

accepted 12 November 2012) In an attempt to study the thermal transport at the interface between nanotubes and graphene, vertically aligned multiwalled...tually increases the thermal barrier in a significant manner. On the other hand, thermal transport properties of thermal tapes and thermally conductive...aforementioned study achieved superior thermal transport properties, the processing and scale-up of the developed process would be prohibitively

Transport processes and mutual interactions of three bacterial strains in saturated porous media

NASA Astrophysics Data System (ADS)

Stumpp, Christine; Lawrence, John R.; Hendry, M. Jim; Maloszewski, Pitor

2010-05-01

Transport processes of the bacterial strains Klebsiella oxytoca, Burkholderia cepacia G4PR-1 and Pseudomonas sp #5 were investigated in saturated column experiments to study the differences in transport characteristics and the mutual interactions of these strains during transport. Soil column experiments (114 mm long x 33 mm in diameter) were conducted with constant water velocities (3.9-5.7 cm/h) through a medium to coarse grained silica sand. All experiments were performed in freshly packed columns in quadruplicate. Chloride was used as tracer to determine the mean transit time, dispersivity and flow rate. It was injected as a pulse into the columns together with the bacterial strains suspended in artificial groundwater medium. In the first setup, each strain was investigated alone. In the second setup, transport processes were performed injecting two strains simultaneously. Finally, the transport characteristics were studied in successive experiments when one bacterium was resident on the sand grains prior to the introduction of the second strain. In all experiments the peak C/Co bacterial concentrations were attenuated with respect to the conservative tracer chloride and a well defined tailing was observed. A one dimensional mathematical model for advective-dispersive transport that accounts for irreversible and reversible sorption was used to analyze the bacterial breakthrough curves and tailing patterns. It was shown that the sorption parameters were different for the three strains that can be explained by the properties of the bacteria. For the species Klebsiella oxytoca and Burkholderia cepacia G4PR-the transport parameters were mostly in the same range independent of the experimental setup. However, Pseudomonas sp #5, which is a motile bacterium, showed differences in the breakthrough curves and sorption parameters during the experiments. The simultaneous and successive experiments indicated an influence on the reversible sorption processes when another strain was present during the transport processes.

Identification of varying time scales in sediment transport using the Hilbert-Huang Transform method

NASA Astrophysics Data System (ADS)

Kuai, Ken Z.; Tsai, Christina W.

2012-02-01

SummarySediment transport processes vary at a variety of time scales - from seconds, hours, days to months and years. Multiple time scales exist in the system of flow, sediment transport and bed elevation change processes. As such, identification and selection of appropriate time scales for flow and sediment processes can assist in formulating a system of flow and sediment governing equations representative of the dynamic interaction of flow and particles at the desired details. Recognizing the importance of different varying time scales in the fluvial processes of sediment transport, we introduce the Hilbert-Huang Transform method (HHT) to the field of sediment transport for the time scale analysis. The HHT uses the Empirical Mode Decomposition (EMD) method to decompose a time series into a collection of the Intrinsic Mode Functions (IMFs), and uses the Hilbert Spectral Analysis (HSA) to obtain instantaneous frequency data. The EMD extracts the variability of data with different time scales, and improves the analysis of data series. The HSA can display the succession of time varying time scales, which cannot be captured by the often-used Fast Fourier Transform (FFT) method. This study is one of the earlier attempts to introduce the state-of-the-art technique for the multiple time sales analysis of sediment transport processes. Three practical applications of the HHT method for data analysis of both suspended sediment and bedload transport time series are presented. The analysis results show the strong impact of flood waves on the variations of flow and sediment time scales at a large sampling time scale, as well as the impact of flow turbulence on those time scales at a smaller sampling time scale. Our analysis reveals that the existence of multiple time scales in sediment transport processes may be attributed to the fractal nature in sediment transport. It can be demonstrated by the HHT analysis that the bedload motion time scale is better represented by the ratio of the water depth to the settling velocity, h/ w. In the final part, HHT results are compared with an available time scale formula in literature.

Modeling the MHC class I pathway by combining predictions of proteasomal cleavage, TAP transport and MHC class I binding.

PubMed

Tenzer, S; Peters, B; Bulik, S; Schoor, O; Lemmel, C; Schatz, M M; Kloetzel, P-M; Rammensee, H-G; Schild, H; Holzhütter, H-G

2005-05-01

Epitopes presented by major histocompatibility complex (MHC) class I molecules are selected by a multi-step process. Here we present the first computational prediction of this process based on in vitro experiments characterizing proteasomal cleavage, transport by the transporter associated with antigen processing (TAP) and MHC class I binding. Our novel prediction method for proteasomal cleavages outperforms existing methods when tested on in vitro cleavage data. The analysis of our predictions for a new dataset consisting of 390 endogenously processed MHC class I ligands from cells with known proteasome composition shows that the immunological advantage of switching from constitutive to immunoproteasomes is mainly to suppress the creation of peptides in the cytosol that TAP cannot transport. Furthermore, we show that proteasomes are unlikely to generate MHC class I ligands with a C-terminal lysine residue, suggesting processing of these ligands by a different protease that may be tripeptidyl-peptidase II (TPPII).

Basin-scale hydrogeologic modeling

NASA Astrophysics Data System (ADS)

Person, Mark; Raffensperger, Jeff P.; Ge, Shemin; Garven, Grant

1996-02-01

Mathematical modeling of coupled groundwater flow, heat transfer, and chemical mass transport at the sedimentary basin scale has been increasingly used by Earth scientists studying a wide range of geologic processes including the formation of excess pore pressures, infiltration-driven metamorphism, heat flow anomalies, nuclear waste isolation, hydrothermal ore genesis, sediment diagenesis, basin tectonics, and petroleum generation and migration. These models have provided important insights into the rates and pathways of groundwater migration through basins, the relative importance of different driving mechanisms for fluid flow, and the nature of coupling between the hydraulic, thermal, chemical, and stress regimes. The mathematical descriptions of basin transport processes, the analytical and numerical solution methods employed, and the application of modeling to sedimentary basins around the world are the subject of this review paper. The special considerations made to represent coupled transport processes at the basin scale are emphasized. Future modeling efforts will probably utilize three-dimensional descriptions of transport processes, incorporate greater information regarding natural geological heterogeneity, further explore coupled processes, and involve greater field applications.

Photoacoustic monitoring of water transport process in calcareous stone coated with biopolymers

NASA Astrophysics Data System (ADS)

May-Crespo, J.; Ortega-Morales, B. O.; Camacho-Chab, J. C.; Quintana, P.; Alvarado-Gil, J. J.; Gonzalez-García, G.; Reyes-Estebanez, M.; Chan-Bacab, M. J.

2016-12-01

Moisture is a critical control of chemical and physical processes leading to stone deterioration. These processes can be enhanced by microbial biofilms and associated exopolymers (EPS). There is limited current understanding of the water transport process across rocks covered by EPS. In the present work, we employed the photoacoustic technique to study the influence of three biopolymers (xanthan, microbactan and arabic gum) in the water transport process of two types of limestone rock of similar mineralogy but contrasting porosity. Both controls of RL (low porosity) and RP (high porosity) presented the higher values of water diffusion coefficient ( D) than biopolymer-coated samples, indicating that biopolymer layers slowed down the transport of water. This trend was steeper for RP samples as water was transported seven times faster than in the more porous rock. Important differences of D values were observed among samples coated by different biopolymers. Scanning electron microscopy and optical microscopy showed that surface topography was different between both types of rocks; adherence of coatings was seen predominantly in the less porous rocks samples. FTIR and NMR analysis showed the presence of pyruvate and acetate in microbactan and xanthan gum, suggesting their participation on adherence to the calcareous surfaces, sealing surface pores. These results indicate that water transport at rock interfaces is dependent on the chemistry of biopolymer and surface porosity. The implications for reduced water transport in stone conservation under the influence of biopolymers include both enhanced and lower deterioration rates along with altered efficiency of biocide treatment of epilithic biofilms.

23 CFR 450.208 - Coordination of planning process activities.

Code of Federal Regulations, 2013 CFR

2013-04-01

... RESEARCH PLANNING ASSISTANCE AND STANDARDS Statewide Transportation Planning and Programming § 450.208... transportation operators to support statewide transportation planning and programming priorities and decisions...

23 CFR 450.208 - Coordination of planning process activities.

Code of Federal Regulations, 2014 CFR

2014-04-01

... RESEARCH PLANNING ASSISTANCE AND STANDARDS Statewide Transportation Planning and Programming § 450.208... transportation operators to support statewide transportation planning and programming priorities and decisions...

23 CFR 450.208 - Coordination of planning process activities.

Code of Federal Regulations, 2012 CFR

2012-04-01

... RESEARCH PLANNING ASSISTANCE AND STANDARDS Statewide Transportation Planning and Programming § 450.208... transportation operators to support statewide transportation planning and programming priorities and decisions...

Current practices on sheep and beef farms in New Zealand for depriving sheep of feed prior to transport for slaughter.

PubMed

Fisher, M W; Gregory, N G; Muir, P D

2012-05-01

To assess current practices on sheep and beef farms that deprive sheep of feed prior to transport to facilitate effluent management and processing at slaughter. A national telephone survey of 122 sheep and 346 sheep and beef farmers was conducted in March and April 2010. They were asked how long sheep were held off green feed prior to transport and why, what environment the sheep were held in, and if that period ever varied. Of the 468 respondents, 303 (65%) removed their sheep from green feed 3-12 h before transport for slaughter, with longer periods reported in the South than North Island. The main reasons given were to reduce the volume of effluent for transport operators (n=174), to prevent wool staining during transport (n=173), and that sheep were better suited to load and travel empty (n=171). Water was provided during feed deprivation by 313 farmers. The period of food deprivation could be altered in response to requirements of transporters and processors, the weather, and by the class of stock involved, although 115/468 (25%) farmers stated that they never changed their normal protocol. Amongst survey respondents, common practices compared favourably with recommendations to reduce effluent during transportation. Previous studies have investigated the effects of fasting lambs whilst in lairage prior to slaughter and focussed on carcass quality such as carcass weight and tenderness. Changes in liveweight and gastrointestinal tract contents suggest feed deprivation reduces the risk of defaecation and urination contributing to the accumulation of effluent during transport and of carcass contamination during processing. However, the point at which that risk is acceptable to transport and processing is unclear. Fasting results in physiological changes indicative of altered metabolism but it is not clear when those changes are indicative of adaptation to food deprivation or metabolic depletion and compromised welfare. There may be opportunities to improve the logistics of livestock preparation, transport and processing.

Implementation of Benchmarking Transportation Logistics Practices and Future Benchmarking Organizations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thrower, A.W.; Patric, J.; Keister, M.

2008-07-01

The purpose of the Office of Civilian Radioactive Waste Management's (OCRWM) Logistics Benchmarking Project is to identify established government and industry practices for the safe transportation of hazardous materials which can serve as a yardstick for design and operation of OCRWM's national transportation system for shipping spent nuclear fuel and high-level radioactive waste to the proposed repository at Yucca Mountain, Nevada. The project will present logistics and transportation practices and develop implementation recommendations for adaptation by the national transportation system. This paper will describe the process used to perform the initial benchmarking study, highlight interim findings, and explain how thesemore » findings are being implemented. It will also provide an overview of the next phase of benchmarking studies. The benchmarking effort will remain a high-priority activity throughout the planning and operational phases of the transportation system. The initial phase of the project focused on government transportation programs to identify those practices which are most clearly applicable to OCRWM. These Federal programs have decades of safe transportation experience, strive for excellence in operations, and implement effective stakeholder involvement, all of which parallel OCRWM's transportation mission and vision. The initial benchmarking project focused on four business processes that are critical to OCRWM's mission success, and can be incorporated into OCRWM planning and preparation in the near term. The processes examined were: transportation business model, contract management/out-sourcing, stakeholder relations, and contingency planning. More recently, OCRWM examined logistics operations of AREVA NC's Business Unit Logistics in France. The next phase of benchmarking will focus on integrated domestic and international commercial radioactive logistic operations. The prospective companies represent large scale shippers and have vast experience in safely and efficiently shipping spent nuclear fuel and other radioactive materials. Additional business processes may be examined in this phase. The findings of these benchmarking efforts will help determine the organizational structure and requirements of the national transportation system. (authors)« less

Growth kinetics of physical vapor transport processes: Crystal growth of the optoelectronic material mercurous chloride

NASA Technical Reports Server (NTRS)

Singh, N. B.; Duval, W. M.

1991-01-01

Physical vapor transport processes were studied for the purpose of identifying the magnitude of convective effects on the crystal growth process. The effects of convection on crystal quality were were studied by varying the aspect ratio and those thermal conditions which ultimately affect thermal convection during physical vapor transport. An important outcome of the present study was the observation that the convection growth rate increased up to a certain value and then dropped to a constant value for high aspect ratios. This indicated that a very complex transport had occurred which could not be explained by linear stability theory. Better quality crystals grown at a low Rayleigh number confirmed that improved properties are possible in convectionless environments.

Information services in social networked transportation : governance and ITS.

DOT National Transportation Integrated Search

2014-06-01

The purpose of this research seeks to understand the functions and the benefits of social : networked transportation (SNT), the processes that make SNT possible, and the institutional : innovations needed to facilitate those processes. First, this re...

Transportation-markings general table of contents with index

DOT National Transportation Integrated Search

2008-01-01

The T-M process outlined in these studies describes and classifies safety aids that assist operators of modes of transportation that process also includes technical and historical perspectives. However; a simple describing and classifying of safety a...

Integrating transportation/transit planning in the overall planning process.

DOT National Transportation Integrated Search

2009-07-01

The purpose of this report is to produce recommendations that will foster more transportation : and land use integration throughout the overall planning process in Delaware. A trend of : population growth and decentralization necessitates a proactive...

User guide : process for quantifying the benefits of research.

DOT National Transportation Integrated Search

2017-07-01

The Minnesota Department of Transportation Research Services has adopted a process for quantifying the monetary benefits of research projects, such as the dollar value of particular ideas when implemented across the states transportation system. T...

Thermally Cross-Linkable Hole Transport Materials for Solution Processed Phosphorescent OLEDs

NASA Astrophysics Data System (ADS)

Kim, Beom Seok; Kim, Ohyoung; Chin, Byung Doo; Lee, Chil Won

2018-04-01

Materials for unique fabrication of a solution-processed, multi-layered organic light-emitting diode (OLED) were developed. Preparation of a hole transport layer with a thermally cross-linkable chemical structure, which can be processed to form a thin film and then transformed into an insoluble film by using an amine-alcohol condensation reaction with heat treatment, was investigated. Functional groups, such as triplenylamine linked with phenylcarbazole or biphenyl, were employed in the chemical structure of the hole transport layer in order to maintain high triplet energy properties. When phenylcarbazole or biphenyl compounds continuously react with triphenylamine under acid catalysis, a chemically stable thin film material with desirable energy-level properties for a blue OLED could be obtained. The prepared hole transport materials showed excellent surface roughness and thermal stability in comparison with the commercial reference material. On the solution-processed model hole transport layer, we fabricated a device with a blue phosphorescent OLED by using sequential vacuum deposition. The maximum external quantum, 19.3%, was improved by more than 40% over devices with the commercial reference material (11.4%).

Reconstructing Sediment Supply, Transport and Deposition Behind the Elwha River Dams

NASA Astrophysics Data System (ADS)

Beveridge, C.

2017-12-01

The Elwha River watershed in Olympic National Park of Washington State, USA is predominantly a steep, mountainous landscape where dominant geomorphic processes include landslides, debris flows and gullying. The river is characterized by substantial variability of channel morphology and fluvial processes, and alternates between narrow bedrock canyons and wider alluvial reaches for much of its length. Literature suggests that the Elwha watershed is topographically and tectonically in steady state. The removal of the two massive hydropower dams along the river in 2013 marked the largest dam removal in history. Over the century long lifespan of the dams, approximately 21 million cubic meters of sediment was impounded behind them. Long term erosion rates documented in this region and reservoir sedimentation data give unprecedented opportunities to test watershed sediment yield models and examine dominant processes that control sediment yield over human time scales. In this study, we aim to reconstruct sediment supply, transport and deposition behind the Glines Canyon Dam (most upstream dam) over its lifespan using a watershed modeling approach. We developed alternative models of varying complexity for sediment production and transport at the network scale driven by hydrologic forcing. We simulate sediment supply and transport in tributaries upstream of the dam. The modeled sediment supply and transport dynamics are based on calibrated formulae (e.g., bedload transport is simulated using Wilcock-Crowe 2003 with modification based on observed bedload transport in the Elwha River). Observational data that aid in our approach include DEM, channel morphology, meteorology, and streamflow and sediment (bedload and suspended load) discharge. We aim to demonstrate how the observed sediment yield behind the dams was influenced by upstream transport supply and capacity limitations, thereby demonstrating the scale effects of flow and sediment transport processes in the Elwha River watershed.

Effect of furosemide on ion transport in the turtle bladder: evidence for direct inhibition of active acid-base transport.

PubMed

Ehrenspeck, G; Voner, C

1985-07-25

The diuretic furosemide inhibits acid-base transport in the short-circuited turtle bladder. It inhibits luminal acidification when present in either mucosal or serosal bathing fluids, but decreases alkalinization only from the serosal side of the tissue. The inhibition of both acid-base transport processes is independent of ambient Cl-; and the disulfonic stilbene, SITS, an inhibitor of Cl--HCO3- exchange, fails to prevent the furosemide-elicited inhibition of alkalinization. These results preclude an absolute requirement of a furosemide-sensitive Cl--HCO3- exchange by these transport processes. The drug also interferes with the CO2-induced stimulation of acidification and alkalinization. The inhibition of the residual acidification in acetazolamide-treated, acidotic bladders, however, suggests an action at sites other than cytosolic carbonic anhydrase. Although active Na+ and Cl- reabsorption and tissue oxygen uptake are also decreased by furosemide, the rate of oxygen consumption uncoupled by 2,4-dinitrophenol is not diminished, indicating a primary inhibition of the various ion transport processes, not of metabolism. It is proposed that inhibition of transepithelial acid-base transport by furosemide in the turtle bladder includes inhibition of the acid-base pumps.

Process analysis of regional aerosol pollution during spring in the Pearl River Delta region, China

NASA Astrophysics Data System (ADS)

Fan, Qi; Lan, Jing; Liu, Yiming; Wang, Xuemei; Chan, Pakwai; Hong, Yingying; Feng, Yerong; Liu, Yexin; Zeng, Yanjun; Liang, Guixiong

2015-12-01

A numerical simulation analysis was performed for three air pollution episodes in the Pearl River Delta (PRD) region during March 2012 using the third-generation air quality modeling system Models-3/CMAQ. The results demonstrated that particulate matter was the primary pollutant for all three pollution episodes and was accompanied by relatively low visibility in the first two episodes. Weather maps indicate that the first two episodes occurred under the influence of warm, wet southerly air flow systems that led to high humidity throughout the region. The liquid phase reaction of gaseous pollutants resulted in the generation of fine secondary particles, which were identified as the primary source of pollution in the first two episodes. The third pollution episode occurred during a warming period following a cold front. Relative humidity was lower during this episode, and coarse particles were the major pollution contributor. Results of process analysis indicated that emissions sources, horizontal transport and vertical transport were the primary factors affecting pollutant concentrations within the near-surface layer during all three episodes, while aerosol processes, cloud processes, horizontal transport and vertical transport had greater influence at approximately 900 m above ground. Cloud processes had a greater impact during the first two pollution episodes because of the higher relative humidity. In addition, by comparing pollution processes from different cities (Guangzhou and Zhongshan), the study revealed that the first two pollution episodes were the result of local emissions within the PRD region and transport between surrounding cities, while the third episode exhibited prominent regional pollution characteristics and was the result of regional pollutant transport.

1996 State Transportation Improvement Program

DOT National Transportation Integrated Search

1996-01-01

The Wyoming Transportation Department utilizes a continuing and comprehensive procress of Needs Analysis, Priority Rating, Financial Analysis, and Manpower Analysis. This "State Transportation Improvement Program" is the culmination of that process. ...

Transportation data clearinghouse

DOT National Transportation Integrated Search

2003-07-01

In late 1999, the Virginia Tech Transportation Institute (VTTI), at the request of the Virginia Department : of Transportation, undertook the process of examining the feasibility of expanding Virginias Operational : Database Management System (ODM...

Surface transportation : clear federal role and criteria-based selection process could improve three national and regional infrastructure programs.

DOT National Transportation Integrated Search

2009-02-01

To help meet increasing transportation demands, the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) created three programs to invest federal funds in national and regional transportation infrastructur...

Spatiotemporal sensitivity analysis of vertical transport of pesticides in soil

EPA Science Inventory

Environmental fate and transport processes are influenced by many factors. Simulation models that mimic these processes often have complex implementations, which can lead to over-parameterization. Sensitivity analyses are subsequently used to identify critical parameters whose un...

Review of operations in the Virginia Department of Transportation's project development process.

DOT National Transportation Integrated Search

2007-01-01

The Virginia Department of Transportation's (VDOT's) project development process (PDP) directs how construction projects are developed. The purpose of this study was to evaluate the manner in which operations is currently considered throughout the PD...

Least-cost transportation planning in ODOT : phase 2 final report.

DOT National Transportation Integrated Search

1996-06-01

This project is intended to suggest ways in which least-cost planning principles could be incorporated into the transportation planning process. The Mt. Hood corridor was chosen for examination. The examination of the planning process highlighted sev...

Developing inexpensive crash countermeasures for Louisiana local roads : request for proposals

DOT National Transportation Integrated Search

2010-09-17

The intelligent transportation system (ITS) includes detectors that capture data from Floridas transportation network and computer hardware and software that process these data. Data processed in real-time can, for example, be used to develop mess...

Integrating intelligent transportation systems within the transportation planning process : an interim handbook.

DOT National Transportation Integrated Search

1998-01-01

The Final Rule on Statewide Planning and Metropolitan Planning issued by the Federal Highway Administration (FHWA) and Federal Transit Administration (FTA) in October, 1993 established revised and more comprehensive processes for metropolitan and sta...

Crew Transportation Technical Standards and Design Evaluation Criteria

NASA Technical Reports Server (NTRS)

Lueders, Kathryn L.; Thomas, Rayelle E. (Compiler)

2015-01-01

Crew Transportation Technical Standards and Design Evaluation Criteria contains descriptions of technical, safety, and crew health medical processes and specifications, and the criteria which will be used to evaluate the acceptability of the Commercial Providers' proposed processes and specifications.

40 CFR 93.107 - Relationship of transportation plan and TIP conformity with the NEPA process.

Code of Federal Regulations, 2010 CFR

2010-07-01

... degree of specificity required in the transportation plan and the specific travel network assumed for air... development studies. Should the NEPA process result in a project with design concept and scope significantly...

CALIBRATION OF SUBSURFACE BATCH AND REACTIVE-TRANSPORT MODELS INVOLVING COMPLEX BIOGEOCHEMICAL PROCESSES

EPA Science Inventory

In this study, the calibration of subsurface batch and reactive-transport models involving complex biogeochemical processes was systematically evaluated. Two hypothetical nitrate biodegradation scenarios were developed and simulated in numerical experiments to evaluate the perfor...

An evaluation of Mexican transportation planning, finance, implementation, and construction processes.

DOT National Transportation Integrated Search

2009-10-01

This research examined the legal, financial, institutional and policy processes that Mexico uses to plan, finance, : construct, and implement its transportation network. It documents through twelve case studies the state of the : practice in planning...

The California general plan process and sustainable transportation planning

DOT National Transportation Integrated Search

2001-11-01

This study reviewed the current and potential utility of California's General Plan process as a tool for promoting more sustainable local transportation systems The study used multiple methods to investigate this issue, including: 1. An extensive lit...

Analysis of erosion and transportation features from lunar orbiter and Apollo photography

NASA Technical Reports Server (NTRS)

Gold, T.

1980-01-01

Certain classes of surface features in Lunar Orbiter and Apollo Panoramic Photographs are identifed and possible correlations between the occurrence of these features and their geographical location on the Moon are studied. Whether evidence of erosion and transport processes not encountered on Earth exists is investigated using the lunar photographs. The variety and intensity of transport processes on the Moon resulting from exposure to plasmas is discussed.

Air Force Journal of Logistics, Volume 32, Number 2, Summer 2008

DTIC Science & Technology

2008-01-01

inventory, overproduction, waiting time, motion, transportation , and over processing waste. Waste is often placed into the following categories (D-O-W-N-T-I-M...simpler tools would be sufficient. * Transportation : moving product between processes is a cost that adds no value to the product. * Intellect: human... Transportation . This is the unnecessary movement probles.e of information or materials. Examples include physical hand-off of information and moving

Identification and functional expression of the Arabidopsis thaliana vacuolar glucose transporter 1 and its role in seed germination and flowering.

PubMed

Aluri, Sirisha; Büttner, Michael

2007-02-13

Sugar compartmentation into vacuoles of higher plants is a very important physiological process, providing extra space for transient and long-term sugar storage and contributing to the osmoregulation of cell turgor and shape. Despite the long-standing knowledge of this subcellular sugar partitioning, the proteins responsible for these transport steps have remained unknown. We have identified a gene family in Arabidopsis consisting of three members homologous to known sugar transporters. One member of this family, Arabidopsis thaliana vacuolar glucose transporter 1 (AtVGT1), was localized to the vacuolar membrane. Moreover, we provide evidence for transport activity of a tonoplast sugar transporter based on its functional expression in bakers' yeast and uptake studies in isolated yeast vacuoles. Analyses of Atvgt1 mutant lines indicate an important function of this vacuolar glucose transporter during developmental processes like seed germination and flowering.

Data-based mathematical modeling of vectorial transport across double-transfected polarized cells.

PubMed

Bartholomé, Kilian; Rius, Maria; Letschert, Katrin; Keller, Daniela; Timmer, Jens; Keppler, Dietrich

2007-09-01

Vectorial transport of endogenous small molecules, toxins, and drugs across polarized epithelial cells contributes to their half-life in the organism and to detoxification. To study vectorial transport in a quantitative manner, an in vitro model was used that includes polarized MDCKII cells stably expressing the recombinant human uptake transporter OATP1B3 in their basolateral membrane and the recombinant ATP-driven efflux pump ABCC2 in their apical membrane. These double-transfected cells enabled mathematical modeling of the vectorial transport of the anionic prototype substance bromosulfophthalein (BSP) that has frequently been used to examine hepatobiliary transport. Time-dependent analyses of (3)H-labeled BSP in the basolateral, intracellular, and apical compartments of cells cultured on filter membranes and efflux experiments in cells preloaded with BSP were performed. A mathematical model was fitted to the experimental data. Data-based modeling was optimized by including endogenous transport processes in addition to the recombinant transport proteins. The predominant contributions to the overall vectorial transport of BSP were mediated by OATP1B3 (44%) and ABCC2 (28%). Model comparison predicted a previously unrecognized endogenous basolateral efflux process as a negative contribution to total vectorial transport, amounting to 19%, which is in line with the detection of the basolateral efflux pump Abcc4 in MDCKII cells. Rate-determining steps in the vectorial transport were identified by calculating control coefficients. Data-based mathematical modeling of vectorial transport of BSP as a model substance resulted in a quantitative description of this process and its components. The same systems biology approach may be applied to other cellular systems and to different substances.

New York City Housing Authority Settlement

EPA Pesticide Factsheets

MarkWest is engaged in the gathering, transportation, and processing of natural gas, the transportation, fractionation, marketing, and storage of natural gas liquids, and the gathering and transportation of crude oil.

Kinetic Theory and Simulation of Single-Channel Water Transport

NASA Astrophysics Data System (ADS)

Tajkhorshid, Emad; Zhu, Fangqiang; Schulten, Klaus

Water translocation between various compartments of a system is a fundamental process in biology of all living cells and in a wide variety of technological problems. The process is of interest in different fields of physiology, physical chemistry, and physics, and many scientists have tried to describe the process through physical models. Owing to advances in computer simulation of molecular processes at an atomic level, water transport has been studied in a variety of molecular systems ranging from biological water channels to artificial nanotubes. While simulations have successfully described various kinetic aspects of water transport, offering a simple, unified model to describe trans-channel translocation of water turned out to be a nontrivial task.

Splash, pop, sizzle: Information processing with phononic computing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sklan, Sophia R.

2015-05-15

Phonons, the quanta of mechanical vibration, are important to the transport of heat and sound in solid materials. Recent advances in the fundamental control of phonons (phononics) have brought into prominence the potential role of phonons in information processing. In this review, the many directions of realizing phononic computing and information processing are examined. Given the relative similarity of vibrational transport at different length scales, the related fields of acoustic, phononic, and thermal information processing are all included, as are quantum and classical computer implementations. Connections are made between the fundamental questions in phonon transport and phononic control and themore » device level approach to diodes, transistors, memory, and logic. .« less

The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled.

PubMed

Göppel, Tobias; Palyulin, Vladimir V; Gerland, Ulrich

2016-07-27

An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a drift-diffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.

In situ investigation of the mechanisms of the transport to tissues of polycyclic aromatic hydrocarbons adsorbed onto the root surface of Kandelia obovata seedlings.

PubMed

Li, Ruilong; Zhu, Yaxian; Zhang, Yong

2015-06-01

A novel method for in situ determination of the polycyclic aromatic hydrocarbons (PAHs) adsorbed onto the root surface of Kandelia obovata seedlings was established using laser-induced time-resolved nanosecond fluorescence spectroscopy (LITRF). The linear dynamic ranges for the established method were 1.5-1240ng/spot for phenanthrene, 1.0-1360ng/spot for pyrene and 5.0-1220ng/spot for benzo[a]pyrene. Then, the mechanisms of PAHs transport from the Ko root surface to tissues were investigated. The three-phase model including fast, slow and very slow fractions was superior to the single or dual-phase model to describe the PAHs transport processes. Moreover, the fast fraction of PAHs transport process was mainly due to passive movement, while the slow and very slow fractions were not. Passive movement was the main process of B[a]P adsorbed onto Ko root surface transport to tissues. In addition, the extent of the PAHs transport to Ko root tissues at different salinity were evaluated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Retardation of mobile radionuclides in granitic rock fractures by matrix diffusion

NASA Astrophysics Data System (ADS)

Hölttä, P.; Poteri, A.; Siitari-Kauppi, M.; Huittinen, N.

Transport of iodide and sodium has been studied by means of block fracture and core column experiments to evaluate the simplified radionuclide transport concept. The objectives were to examine the processes causing retention in solute transport, especially matrix diffusion, and to estimate their importance during transport in different scales and flow conditions. Block experiments were performed using a Kuru Grey granite block having a horizontally planar natural fracture. Core columns were constructed from cores drilled orthogonal to the fracture of the granite block. Several tracer tests were performed using uranine, 131I and 22Na as tracers at water flow rates 0.7-50 μL min -1. Transport of tracers was modelled by applying the advection-dispersion model based on the generalized Taylor dispersion added with matrix diffusion. Scoping calculations were combined with experiments to test the model concepts. Two different experimental configurations could be modelled applying consistent transport processes and parameters. The processes, advection-dispersion and matrix diffusion, were conceptualized with sufficient accuracy to replicate the experimental results. The effects of matrix diffusion were demonstrated on the slightly sorbing sodium and mobile iodine breakthrough curves.

The Catalytic Pellet: A Rich Prototype for Engineering Up-Scaling

ERIC Educational Resources Information Center

Arce, Pedro E.; Oyanader, Mario; Whitaker, Stephen

2007-01-01

This paper focuses on the use of scaling aspects for understanding transport processes with reaction in catalytic pores and pellets. The idea is to identify a systematic up-scaling approach in the learning process to help students with several concepts related to the transport-reaction process and the mathematical description associated with them.…

Peritoneal Fluid Transport rather than Peritoneal Solute Transport Associates with Dialysis Vintage and Age of Peritoneal Dialysis Patients.

PubMed

Waniewski, Jacek; Antosiewicz, Stefan; Baczynski, Daniel; Poleszczuk, Jan; Pietribiasi, Mauro; Lindholm, Bengt; Wankowicz, Zofia

2016-01-01

During peritoneal dialysis (PD), the peritoneal membrane undergoes ageing processes that affect its function. Here we analyzed associations of patient age and dialysis vintage with parameters of peritoneal transport of fluid and solutes, directly measured and estimated based on the pore model, for individual patients. Thirty-three patients (15 females; age 60 (21-87) years; median time on PD 19 (3-100) months) underwent sequential peritoneal equilibration test. Dialysis vintage and patient age did not correlate. Estimation of parameters of the two-pore model of peritoneal transport was performed. The estimated fluid transport parameters, including hydraulic permeability (LpS), fraction of ultrasmall pores (α u), osmotic conductance for glucose (OCG), and peritoneal absorption, were generally independent of solute transport parameters (diffusive mass transport parameters). Fluid transport parameters correlated whereas transport parameters for small solutes and proteins did not correlate with dialysis vintage and patient age. Although LpS and OCG were lower for older patients and those with long dialysis vintage, αu was higher. Thus, fluid transport parameters--rather than solute transport parameters--are linked to dialysis vintage and patient age and should therefore be included when monitoring processes linked to ageing of the peritoneal membrane.

Transportation Infrastructure: FHWA Should Access and Compare the Benefits of Projects When Awarding Discretionary Grants

DOT National Transportation Integrated Search

1999-09-24

The Transportation Equity Act for the 21st Century (TEA-21) required a number of changes to the Department of Transportation's (DOT) process for awarding discretionary grants administered by the FHWA. The act directed the Secretary of Transportation ...

Connected vehicle impacts on transportation planning technical memorandum #6: skills and expertise required to incorporate connected vehicles into transportation planning.

DOT National Transportation Integrated Search

2016-02-08

Professional development and training are essential to the incorporation of connected/automated vehicles (C/AV) into the transportation planning process. In order to guarantee a successful deployment, transportation planning agencies and their stakeh...

48 CFR 47.305 - Solicitation provisions, contract clauses, and transportation factors.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., and award phases of the acquisition process (see 47.105). (b) To the extent feasible, activities shall..., contract clauses, and transportation factors. 47.305 Section 47.305 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47...

48 CFR 47.305 - Solicitation provisions, contract clauses, and transportation factors.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., and award phases of the acquisition process (see 47.105). (b) To the extent feasible, activities shall..., contract clauses, and transportation factors. 47.305 Section 47.305 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47...

Caltrans WeatherShare Phase II System: An Application of Systems and Software Engineering Process to Project Development

DOT National Transportation Integrated Search

2009-08-25

In cooperation with the California Department of Transportation, Montana State University's Western Transportation Institute has developed the WeatherShare Phase II system by applying Systems Engineering and Software Engineering processes. The system...

23 CFR 450.316 - Interested parties, participation, and consultation.

Code of Federal Regulations, 2013 CFR

2013-04-01

... public transportation employees, freight shippers, providers of freight transportation services, private... at key decision points, including but not limited to a reasonable opportunity to comment on the... extent practicable, develop a documented process(es) that outlines roles, responsibilities, and key...

23 CFR 450.316 - Interested parties, participation, and consultation.

Code of Federal Regulations, 2012 CFR

2012-04-01

... public transportation employees, freight shippers, providers of freight transportation services, private... at key decision points, including but not limited to a reasonable opportunity to comment on the... extent practicable, develop a documented process(es) that outlines roles, responsibilities, and key...

23 CFR 450.316 - Interested parties, participation, and consultation.

Code of Federal Regulations, 2014 CFR

2014-04-01

... public transportation employees, freight shippers, providers of freight transportation services, private... at key decision points, including but not limited to a reasonable opportunity to comment on the... extent practicable, develop a documented process(es) that outlines roles, responsibilities, and key...

Vehicle Infrastructure Integration (VII) data use analysis and processing : project summary report.

DOT National Transportation Integrated Search

2012-03-01

The purpose of the Data Use Analysis and Processing (DUAP) project is to support the : Michigan Department of Transportation (MDOT) and its partners in evaluating uses and : benefits of connected vehicle data in transportation agency management and :...

PREDICTING SUBSURFACE CONTAMINANT TRANSPORT AND TRANSFORMATION: CONSIDERATIONS FOR MODEL SELECTION AND FIELD VALIDATION

EPA Science Inventory

Predicting subsurface contaminant transport and transformation requires mathematical models based on a variety of physical, chemical, and biological processes. The mathematical model is an attempt to quantitatively describe observed processes in order to permit systematic forecas...

Gathering Information from Transport Systems for Processing in Supply Chains

NASA Astrophysics Data System (ADS)

Kodym, Oldřich; Unucka, Jakub

2016-12-01

Paper deals with complex system for processing information from means of transport acting as parts of train (rail or road). It focuses on automated information gathering using AutoID technology, information transmission via Internet of Things networks and information usage in information systems of logistic firms for support of selected processes on MES and ERP levels. Different kinds of gathered information from whole transport chain are discussed. Compliance with existing standards is mentioned. Security of information in full life cycle is integral part of presented system. Design of fully equipped system based on synthesized functional nodes is presented.

Skylab and solar exploration. [chromosphere-corona structure, energy production and heat transport processes

NASA Technical Reports Server (NTRS)

Von Puttkamer, J.

1973-01-01

Review of some of the findings concerning solar structure, energy production, and heat transport obtained with the aid of the manned Skylab space station observatory launched on May 14, 1973. Among the topics discussed are the observation of thermonuclear fusion processes which cannot be simulated on earth, the observation of short-wave solar radiation not visible to observers on earth, and the investigation of energy-transport processes occurring in the photosphere, chromosphere, and corona. An apparent paradox is noted in that the cooler chromosphere is heating the hotter corona, seemingly in defiance of the second law of thermodynamics, thus suggesting that a nonthermal mechanism underlies the energy transport. Understanding of this nonthermal mechanism is regarded as an indispensable prerequisite for future development of plasma systems for terrestrial applications.

TRANSPORT PLANNING MODEL FOR WIDE AREA RECYCLING SYSTEM OF INDUSTRIAL WASTE PLASTIC

NASA Astrophysics Data System (ADS)

Arai, Yasuhiro; Kawamura, Hisashi; Koizumi, Akira; Mogi, Satoshi

To date, the majority of industrial waste plastic generated in an urban city has been processed into landfill. However, it is now necessary to actively utilize that plastic as a useful resource to create a recycling society with a low environment influence. In order to construct a reasonable recycling system, it is necessary to address the "transportation problem," which means determining how much industrial waste plastic is to be transported to what location. With the goal of eliminating landfill processing, this study considers a transport planning model for industrial waste plastic applying linear programming. The results of running optimized calculations under given scenarios clarified not only the possibilities for recycle processing in the Metropolitan area, but also the validity of wide area recycling system.