Accelerated detection of viral particles by combining AC electric field effects and micro-Raman spectroscopy.

Science.gov (United States)

Tomkins, Matthew Robert; Liao, David Shiqi; Docoslis, Aristides

2015-01-08

A detection method that combines electric field-assisted virus capture on antibody-decorated surfaces with the "fingerprinting" capabilities of micro-Raman spectroscopy is demonstrated for the case of M13 virus in water. The proof-of-principle surface mapping of model bioparticles (protein coated polystyrene spheres) captured by an AC electric field between planar microelectrodes is presented with a methodology for analyzing the resulting spectra by comparing relative peak intensities. The same principle is applied to dielectrophoretically captured M13 phage particles whose presence is indirectly confirmed with micro-Raman spectroscopy using NeutrAvidin-Cy3 as a labeling molecule. It is concluded that the combination of electrokinetically driven virus sampling and micro-Raman based signal transduction provides a promising approach for time-efficient and in situ detection of viruses.

High Temperature Polymer Electrolyte Fuel Cells

DEFF Research Database (Denmark)

Fleige, Michael

This thesis presents the development and application of electrochemical half-cell setups to study the catalytic reactions taking place in High Temperature Polymer Electrolyte Fuel Cells (HTPEM-FCs): (i) a pressurized electrochemical cell with integrated magnetically coupled rotating disk electrode...... oxidation of ethanol is in principle a promising concept to supply HTPEM-FCs with a sustainable and on large scale available fuel (ethanol from biomass). However, the intermediate temperature tests in the GDE setup show that even on Pt-based catalysts the reaction rates become first significant...... at potentials, which approach the usual cathode potentials of HTPEM-FCs. Therefore, it seems that H3PO4-based fuel cells are not much suited to efficiently convert ethanol in accordance with findings in earlier research papers. Given that HTPEM-FCs can tolerate CO containing reformate gas, focusing research...

Development of a 400 W High Temperature PEM Fuel Cell Power Pack

DEFF Research Database (Denmark)

Schaltz, Erik; Jespersen, Jesper Lebæk; Rasmussen, Peter Omand

2006-01-01

reformer design because CO removal is not needed. A fuel like methanol would be a preferable choice for reforming when using HTPEM fuel cells because of its high energy density and low reforming temperatures. The thermal integration and use of HTPEM fuel cells with methanol reformers show promising results......When using pressurized hydrogen to fuel a fuel cell, much space is needed for fuel storage. This is undesirable especially with mobile or portable fuel cell systems, where refuelling also often is inconvenient. Using a reformed liquid carbonhydrate can reduce this fuel volume considerably. Nafion...... based low temperature PEM (LTPEM) fuel cells are very intolerant to reformate gas because of the presence of CO. PBI based high temperature PEM (HTPEM) fuel cells can operate stable at much higher CO concentrations. This makes the HTPEM very suitable for applications using a reformer, and could simplify...

Theragnosis-based combined cancer therapy using doxorubicin-conjugated microRNA-221 molecular beacon.

Science.gov (United States)

Lee, Jonghwan; Choi, Kyung-Ju; Moon, Sung Ung; Kim, Soonhag

2016-01-01

Recently, microRNA (miRNA or miR) has emerged as a new cancer biomarker because of its high expression level in various cancer types and its role in the control of tumor suppressor genes. In cancer studies, molecular imaging and treatment based on target cancer markers have been combined to facilitate simultaneous cancer diagnosis and therapy. In this study, for combined therapy with diagnosis of cancer, we developed a doxorubicin-conjugated miR-221 molecular beacon (miR-221 DOXO MB) in a single platform composed of three different nucleotides: miR-221 binding sequence, black hole quencher 1 (BHQ1), and doxorubicin binding site. Imaging of endogenous miR-221 was achieved by specific hybridization between miR-221 and the miR-221 binding site in miR-221 DOXO MB. The presence of miR-221 triggered detachment of the quencher oligo and subsequent activation of a fluorescent signal of miR-221 DOXO MB. Simultaneous cancer therapy in C6 astrocytoma cells and nude mice was achieved by inhibition of miRNA-221 function that downregulates tumor suppressor genes. The detection of miR-221 expression and inhibition of miR-221 function by miR-221 DOXO MB provide the feasibility as a cancer theragnostic probe. Furthermore, a cytotoxic effect was induced by unloading of doxorubicin intercalated into miR-221 DOXO MB inside cells. Loss of miR-221 function and cytotoxicity induced by the miR-221 DOXO MB provides combined therapeutic efficacy against cancers. This method could be used as a new theragnostic probe with enhanced therapy to detect and inhibit many cancer-related miRNAs. Copyright © 2015 Elsevier Ltd. All rights reserved.

High-performance nanostructured thermoelectric generators for micro combined heat and power systems

International Nuclear Information System (INIS)

Zhang, Yanliang; Wang, Xiaowei; Cleary, Martin; Schoensee, Luke; Kempf, Nicholas; Richardson, Joseph

2016-01-01

Highlights: • A TEG is fabricated using high-efficiency nanostructured thermoelectric materials. • The TEG produces high power density of 2.1 W/cm"2 with 5.3% electrical efficiency. • A micro-CHP system is demonstrated by integrating the TEG into a gas-fired boiler. - Graphical Abstract: - Abstract: Micro combined heat and power (micro-CHP) systems are promising pathways to increase power generation efficiencies. Here a new class of micro-CHP system without moving parts is experimentally demonstrated by integrating high-temperature thermoelectric generators (TEGs) and residential gas-fired boilers, thus enabling wide applications. The TEGs fabricated using high-efficiency nanostructured bulk half-Heusler alloys generate ultrahigh power density of 2.1 W/cm"2 with 5.3% electrical efficiency under 500 °C temperature differences between the hot and cold sides. The TEG system harnesses the untapped exergy between the combustion gas and water, and converts thermal energy into electric power with 4% heat-to-electricity efficiency based on the total heat input into the TEGs. The high-performance TEGs open lots of opportunities to transform power generation technologies and improve energy efficiency.

Investigation on Wire Electrochemical Micro Machining of Ni-based Metallic Glass

International Nuclear Information System (INIS)

Meng, Lingchao; Zeng, Yongbin; Zhu, Di

2017-01-01

Highlights: • WECMM with nanosecond pulses is proposed firstly for fabricating micro complex components based on metallic glasses. • Applicable electrolyte for WECMM of the Ni-based MG is discussed. • Significantly uniform machined surface is achieved in H_2SO_4 solution. • High machining efficiency and stability are obtained experimentally by modifying pulse waveforms and electrolyte compositions. • Complex microstructures of Ni-based MG are fabricated by WECMM with optimized parameters. - Abstract: Metallic glasses (MGs) have been recognized as promising materials for realizing high-performance micro devices in micro electromechanical systems (MEMS) due to their excellent functional and structural characteristics. However, the applications of MGs are currently limited because of the difficulty of shaping them on the microscale. Wire electrochemical micro machining (WECMM) is increasingly recognized as a flexible and effective method to fabricate complex-shaped micro metal components with many advantages relative to the thermomechanical processing, which appears to be well suitable for micro shaping of MGs. We consider the example of a Ni-based MG, Ni_7_2Cr_1_9Si_7B_2, which has a typical passivation characteristic in 0.1 M H_2SO_4 solution. The transpassive process can be used for localized material removal when combined with nanosecond pulsed WECMM technique. In present work, the applicable electrolyte for WECMM of the Ni-based MG was discussed firstly. Then the voltage pulse waveform and electrolyte composition were modified to improve machining efficiency and stability. Several complex microstructures such as micro curved cantilever beam, micro gear, and micro square helix were machined with different optimized parameters.

Modelling of a High Temperature PEM Fuel Cell Stack using Electrochemical Impedance Spectroscopy

DEFF Research Database (Denmark)

Andreasen, Søren Juhl; Jespersen, Jesper Lebæk; Kær, Søren Knudsen

2008-01-01

This work presents the development of an equivalent circuit model of a 65 cell high temperature PEM (HTPEM) fuel cell stack using Electrochemical Impedance Spectroscopy (EIS). The HTPEM fuel cell membranes used are PBI-based and uses phosphoric acid as proton conductor. The operating temperature...

A novel method of predicting microRNA-disease associations based on microRNA, disease, gene and environment factor networks.

Science.gov (United States)

Peng, Wei; Lan, Wei; Zhong, Jiancheng; Wang, Jianxin; Pan, Yi

2017-07-15

MicroRNAs have been reported to have close relationship with diseases due to their deregulation of the expression of target mRNAs. Detecting disease-related microRNAs is helpful for disease therapies. With the development of high throughput experimental techniques, a large number of microRNAs have been sequenced. However, it is still a big challenge to identify which microRNAs are related to diseases. Recently, researchers are interesting in combining multiple-biological information to identify the associations between microRNAs and diseases. In this work, we have proposed a novel method to predict the microRNA-disease associations based on four biological properties. They are microRNA, disease, gene and environment factor. Compared with previous methods, our method makes predictions not only by using the prior knowledge of associations among microRNAs, disease, environment factors and genes, but also by using the internal relationship among these biological properties. We constructed four biological networks based on the similarity of microRNAs, diseases, environment factors and genes, respectively. Then random walking was implemented on the four networks unequally. In the walking course, the associations can be inferred from the neighbors in the same networks. Meanwhile the association information can be transferred from one network to another. The results of experiment showed that our method achieved better prediction performance than other existing state-of-the-art methods. Copyright © 2017 Elsevier Inc. All rights reserved.

Optimal coordinated scheduling of combined heat and power fuel cell, wind, and photovoltaic units in micro grids considering uncertainties

International Nuclear Information System (INIS)

Bornapour, Mosayeb; Hooshmand, Rahmat-Allah; Khodabakhshian, Amin; Parastegari, Moein

2016-01-01

In this paper, a stochastic model is proposed for coordinated scheduling of combined heat and power units in micro grid considering wind turbine and photovoltaic units. Uncertainties of electrical market price; the speed of wind and solar radiation are considered using a scenario-based method. In the method, scenarios are generated using roulette wheel mechanism based on probability distribution functions of input random variables. Using this method, the probabilistic specifics of the problem are distributed and the problem is converted to a deterministic one. The type of the objective function, coordinated scheduling of combined heat and power, wind turbine, and photovoltaic units change this problem to a mixed integer nonlinear one. Therefore to solve this problem modified particle swarm optimization algorithm is employed. The mentioned uncertainties lead to an increase in profit. Moreover, the optimal coordinated scheduling of renewable energy resources and thermal units in micro grids increase the total profit. In order to evaluate the performance of the proposed method, its performance is executed on modified 33 bus distributed system as a micro grid. - Highlights: • Stochastic model is proposed for coordinated scheduling of renewable energy sources. • The effect of combined heat and power is considered. • Maximizing profits of micro grid is considered as objective function. • Considering the uncertainties of problem lead to profit increasing. • Optimal scheduling of renewable energy sources and thermal units increases profit.

The capacity credit of micro-combined heat and power

International Nuclear Information System (INIS)

Hawkes, A.D.; Leach, M.A.

2008-01-01

This article is concerned with development of a methodology to determine the capacity credit of micro-combined heat and power (micro-CHP), and application of the method for the UK. Capacity credit is an important parameter in electricity system planning because it measures the amount of conventional generation that would be displaced by an alternative technology. Firstly, a mathematical formulation is presented. Capacity credit is then calculated for three types of micro-CHP units-Stirling engine, internal combustion engine, and fuel cell systems-operating under various control strategies. It is found that low heat-to-power ratio fuel cell technologies achieve the highest capacity credit of approximately 85% for a 1.1 GW penetration when a heat-led control strategy is applied. Higher heat-to-power ratio Stirling engine technology achieves approximately 33% capacity credit for heat-led operation. Low heat-to-power ratio technologies achieve higher capacity credit because they are able to continue operating even when heat demand is relatively low. Capacity credit diminishes as penetration of the technology increases. Overall, the high capacity credit of micro-CHP contributes to the viewpoint that the technology can help meet a number of economic and environmental energy policy aims

Combined micro-PIXE and NIR Raman spectroscopic plaque characterisation in a human atherosclerotic aorta sample

International Nuclear Information System (INIS)

Brands, P.J.M.; Poll, S.W.E. van de; Quaedackers, J.A.; Mutsaers, P.H.A.; Puppels, G.J.; Laarse, A. van der; Voigt, M.J.A. de

2001-01-01

Raman spectroscopy can be applied to characterise the chemical composition of an atherosclerotic plaque in vivo. In the near future this technique may become available for use in (coronary) arteries of living patients. For this moment, Raman spectroscopy is applied on artery samples in vitro, to study progression and regression of atherosclerotic plaque. Raman spectroscopy provides chemical information on a molecular basis. In this study, micro-particle induced X-ray emission (micro-PIXE) is applied to provide additional information on the elemental composition of the artery. Furthermore, the combined techniques allow for validation of the structures studied with Raman spectroscopy. This study proves that it is possible to combine and compare both techniques using the same region on the same sample if proper sample preparation is applied. Comparison shows that regions appearing in the Raman spectroscopy results can also be distinguished in micro-PIXE and backscattering spectroscopy (BS) distributions and vice versa. Combining both techniques makes it possible to separate phospholipids from triglycerides. Combined Raman spectroscopy and micro-PIXE/BS is recommended for studying progression and regression of atherosclerosis

Study of squeeze film damping in a micro-beam resonator based on micro-polar theory

Directory of Open Access Journals (Sweden)

Mina Ghanbari

Full Text Available In this paper, squeeze film damping in a micro-beam resonator based on micro-polar theory has been investigated. The proposed model for this study consists of a clamped-clamped micro-beam bounded between two fixed layers. The gap between the micro-beam and layers is filled with air. As fluid behaves differently in micro scale than macro, the micro-scale fluid field in the gap has been modeled based on micro-polar theory. Equation of motion governing transverse deflection of the micro- beam based on modified couple stress theory and also non-linear Reynolds equation of the fluid field based on micropolar theory have been non-dimensionalized, linearized and solved simultaneously in order to calculate the quality factor of the resonator. The effect of micropolar parameters of air on the quality factor has been investigated. The quality factor of the of the micro-beam resonator for different values of non-dimensionalized length scale of the beam, squeeze number and also non-dimensionalized pressure has been calculated and compared to the obtained values of quality factor based on classical theory.

Design of Energy Storage Management System Based on FPGA in Micro-Grid

Science.gov (United States)

Liang, Yafeng; Wang, Yanping; Han, Dexiao

2018-01-01

Energy storage system is the core to maintain the stable operation of smart micro-grid. Aiming at the existing problems of the energy storage management system in the micro-grid such as Low fault tolerance, easy to cause fluctuations in micro-grid, a new intelligent battery management system based on field programmable gate array is proposed : taking advantage of FPGA to combine the battery management system with the intelligent micro-grid control strategy. Finally, aiming at the problem that during estimation of battery charge State by neural network, initialization of weights and thresholds are not accurate leading to large errors in prediction results, the genetic algorithm is proposed to optimize the neural network method, and the experimental simulation is carried out. The experimental results show that the algorithm has high precision and provides guarantee for the stable operation of micro-grid.

In vitro synchrotron-based radiography of micro-gap formation at the implant-abutment interface of two-piece dental implants.

Science.gov (United States)

Rack, A; Rack, T; Stiller, M; Riesemeier, H; Zabler, S; Nelson, K

2010-03-01

Micro-gap formation at the implant-abutment interface of two-piece dental implants was investigated in vitro using high-resolution radiography in combination with hard X-ray synchrotron radiation. Images were taken with the specimen under different mechanical loads of up to 100 N. The aim of this investigation was to prove the existence of micro-gaps for implants with conical connections as well as to study the mechanical behavior of the mating zone of conical implants during loading. Synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in highly attenuating objects. The first illustration of a micro-gap which was previously indistinguishable by laboratory methods underlines that the complex micro-mechanical behavior of implants requires further in vitro investigations where synchrotron-based micro-imaging is one of the prerequisites.

Quantification of in situ temperature measurements on a PBI-based high temperature PEMFC unit cell

DEFF Research Database (Denmark)

Lebæk, Jesper; Ali, Syed Talat; Møller, Per

2010-01-01

The temperature is a very important operating parameter for all types of fuel cells. In the present work distributed in situ temperature measurements are presented on a polybenzimidazole based high temperature PEM fuel cell (HT-PEM). A total of 16 T-type thermocouples were embedded on both the an...

Durable and mass producible polymer surface structures with different combinations of micro–micro hierarchy

International Nuclear Information System (INIS)

Jiang, Yu; Suvanto, Mika; Pakkanen, Tapani A

2016-01-01

Extensive studies have been performed with the aim of fabricating hierarchical surface structures inspired by nature. However, synthetic hierarchical structures have to sacrifice mechanical resistance to functionality by introducing finer scaled structures. Therefore, surfaces are less durable. Surface micro–micro hierarchy has been proven to be effective in replacing micro–nano hierarchy in the sense of superhydrophobicity. However, less attention has been paid to the combined micro–micro hierarchies with surface pillars and pits incorporated together. The fabrication of this type of hierarchy may be less straightforward, with the possibility of being a complicated multi-step process. In this study, we present a simple yet mass producible fabrication method for hierarchical structures with different combinations of surface pillars and pits. The fabrication was based on only one aluminum (Al) mold with sequential mountings. The fabricated structures exhibit high mechanical durability and structural stabilities with a normal load up to 100 kg. In addition, the theoretical estimation of the wetting state shows a promising way of stabilizing a water droplet on the surface pit structures with a more stable Cassie–Baxter state. (paper)

MicroRNA modulation combined with sunitinib as a novel therapeutic strategy for pancreatic cancer

Directory of Open Access Journals (Sweden)

Passadouro M

2014-07-01

Full Text Available Marta Passadouro,1,2 Maria C Pedroso de Lima,1,2 Henrique Faneca11Center for Neuroscience and Cell Biology, 2Department of Life Sciences, Faculty of Science and Technology, University of Coimbra, Coimbra, PortugalAbstract: Pancreatic ductal adenocarcinoma (PDAC is a highly aggressive and mortal cancer, characterized by a set of known mutations, invasive features, and aberrant microRNA expression that have been associated with hallmark malignant properties of PDAC. The lack of effective PDAC treatment options prompted us to investigate whether microRNAs would constitute promising therapeutic targets toward the generation of a gene therapy approach with clinical significance for this disease. In this work, we show that the developed human serum albumin–1-palmitoyl-2-oleoyl-sn-glycero-3-ethylphosphocholine:cholesterol/anti-microRNA oligonucleotides (+/– (4/1 nanosystem exhibits the ability to efficiently deliver anti-microRNA oligonucleotides targeting the overexpressed microRNAs miR-21, miR-221, miR-222, and miR-10 in PDCA cells, promoting an almost complete abolishment of microRNA expression. Silencing of these microRNAs resulted in a significant increase in the levels of their targets. Moreover, the combination of microRNA silencing, namely miR-21, with low amounts of the chemotherapeutic drug sunitinib resulted in a strong and synergistic antitumor effect, showing that this combined strategy could be of great importance for therapeutic application in PDAC. Keywords: pancreatic cancer gene therapy, anti-microRNAs oligonucleotides, delivery nanosystems, albumin-associated lipoplexes

In vitro synchrotron-based radiography of micro-gap formation at the implant–abutment interface of two-piece dental implants

International Nuclear Information System (INIS)

Rack, A.; Rack, T.; Stiller, M.; Riesemeier, H.; Zabler, S.; Nelson, K.

2010-01-01

Micro-radiography using hard X-ray synchrotron radiation is the first potential tool to allow an evaluation of the mechanical behavior of the dental implant–abutment complex during force application, thus enabling the enhancement of the design of dental implants which has been based on theoretical analysis to date. Micro-gap formation at the implant–abutment interface of two-piece dental implants was investigated in vitro using high-resolution radiography in combination with hard X-ray synchrotron radiation. Images were taken with the specimen under different mechanical loads of up to 100 N. The aim of this investigation was to prove the existence of micro-gaps for implants with conical connections as well as to study the mechanical behavior of the mating zone of conical implants during loading. Synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in highly attenuating objects. The first illustration of a micro-gap which was previously indistinguishable by laboratory methods underlines that the complex micro-mechanical behavior of implants requires further in vitro investigations where synchrotron-based micro-imaging is one of the prerequisites

In vitro synchrotron-based radiography of micro-gap formation at the implant–abutment interface of two-piece dental implants

Energy Technology Data Exchange (ETDEWEB)

Rack, A., E-mail: arack@snafu.de [European Synchrotron Radiation Facility, Grenoble (France); Rack, T. [Charité, Department of Oral and Maxillofacial Surgery, Clinical Navigation and Robotics, Berlin (Germany); Stiller, M. [Charité, Department of Maxillofacial and Facial-Plastic Surgery, Division of Oral Medicine, Radiology and Surgery, Berlin (Germany); Riesemeier, H. [Bundesanstalt für Materialforschung und -prüfung, Division Structure Analysis, Polymer Analysis, Berlin (Germany); Zabler, S. [Technical University of Berlin, Institute for Materials Engineering (Germany); Nelson, K. [Charité, Department of Oral and Maxillofacial Surgery, Clinical Navigation and Robotics, Berlin (Germany)

2010-03-01

Micro-radiography using hard X-ray synchrotron radiation is the first potential tool to allow an evaluation of the mechanical behavior of the dental implant–abutment complex during force application, thus enabling the enhancement of the design of dental implants which has been based on theoretical analysis to date. Micro-gap formation at the implant–abutment interface of two-piece dental implants was investigated in vitro using high-resolution radiography in combination with hard X-ray synchrotron radiation. Images were taken with the specimen under different mechanical loads of up to 100 N. The aim of this investigation was to prove the existence of micro-gaps for implants with conical connections as well as to study the mechanical behavior of the mating zone of conical implants during loading. Synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in highly attenuating objects. The first illustration of a micro-gap which was previously indistinguishable by laboratory methods underlines that the complex micro-mechanical behavior of implants requires further in vitro investigations where synchrotron-based micro-imaging is one of the prerequisites.

Performance Improvement of a Micro Impulse Water Turbine Based on Orthogonal Array

OpenAIRE

Tang, Lingdi; Yuan, Shouqi; Tang, Yue

2017-01-01

The study on structural design and efficiency improvement of the micro impulse water turbine with the super-low specific speed has rarely been reported in literature. In this paper, a micro impulse water turbine was optimized on the base of the orthogonal array of L18(37) with six factors. The range analysis and variance analysis were conducted to present the significance ranking of factors and the optimal combinations of factors, aiming to improve the water turbine efficiency taken as the ex...

Micro combined heat and power operating on renewable energy for residential building

International Nuclear Information System (INIS)

Aoun, Bernard

2008-01-01

The building sector consumes more than 43% of the total national energy consumption in France leading to more than 25% of CO 2 emissions associated to this energy consumption. A large number of options exist to limit CO 2 emissions and to improve the performance of buildings. One of these options is developed in this thesis, the use of renewable energies (solar and biomass) in combined production of heat and power. Conventional systems of combined heat and power production are briefly analyzed. The major part of this work has been focused on the development of a micro-CHP system based on an organic Rankine cycle operating on renewable energies intermittent and non-intermittent (solar and wood). The working fluids have been analyzed to allow reaching high thermodynamic performance. The different promising technologies, for each components of the system are identified, depending on the working fluid. A special test bench has been designed and realized to test and characterize an oil-free vapor scroll expander suitable for our application. The different components have been sized using computerized tools developed for the modeling of the Organic Rankine cycle. A dynamic simulation tool has been developed to simulate the annual performance of the micro-CHP system operating under different climate conditions and thermal loads. Results show that the micro-CHP system could save more than 40% of the primary energy consumption and up to 60% of CO 2 emissions. The Levelized electricity cost has been calculated using economic analysis; results show that the electricity cost (50 c-euros/kWhel) is still high compared to other technologies. (author)

Micro tooling technologies for polymer micro replication: direct, indirect and hybrid process chains

DEFF Research Database (Denmark)

Tosello, Guido; Hansen, Hans Nørgaard

2009-01-01

The increasing employment of micro products, of products containing micro parts and of products with micro-structured surfaces calls for mass fabrication technologies based on replication processes. In many cases, a suitable solution is given by the use of polymer micro products, whose production...... and performance of the corresponding micro mould. Traditional methods of micro tooling, such as various machining processes (e.g. micro milling, micro electrical discharge machining) have already reached their limitations with decreasing dimensions of mould inserts and cavities. To this respect, tooling process...... chains based on combination of micro manufacturing processes (defined as hybrid tooling) have been established in order to obtain further features miniaturization and increased accuracy. In this paper, examples and performance of different hybrid tooling approaches as well as challenges, opportunities...

Micro-Injection Moulding In-Line Quality Assurance Based on Product and Process Fingerprints

DEFF Research Database (Denmark)

Baruffi, Federico; Calaon, Matteo; Tosello, Guido

2018-01-01

significant dimensional features of the micro part were measured using a focus variation microscope. Their dependency on the variation of µIM process parameters was studied with a Design of Experiments (DoE) statistical approach. A correlation study allowed the identification of the product fingerprint, i...... of the study showed that the dimensional quality of the micro component could be effectively controlled in-line by combining the two fingerprints, thus opening the door for future µIM in-line process optimization and quality assessment.......Micro-injection moulding (μIM) is a replication-based process enabling the cost-effective production of complex and net-shaped miniaturized plastic components. The micro-scaled size of such parts poses great challenges in assessing their dimensional quality and often leads to time...

Agent based approach for engineering and control of micro-grids

International Nuclear Information System (INIS)

Basso, Gillian

2013-01-01

Energy management is, nowadays, a subject of uttermost importance. Indeed, we are facing growing concerns such as petroleum reserve depletion, earth global warming or power quality (e.g. avoiding blackouts during peak times). Smart grids is an attempt to solve such problems, by adding to power grids bidirectional communications and ICT capabilities in order to provide an intelligent autonomic management for the grid. This thesis focuses on the management of micro-grids thanks to multi-agent systems (MAS). Micro-grids are low-power networks, composed of small and decentralized energy producers (possibly renewable) and consumers. These networks can be connected to the main grid or islanded, this make them more complex. Due to their complexity and their geographical distribution, smart grids and micro-grids can not be easily managed by a centralized system. Distributed artificial intelligences especially MAS appear to be a solution to resolve problems related to smart grids. Firstly we defined an approach implementing feedback loops. These feedback loops exist in complex systems which can be defined with several abstraction levels. Two levels are interacting. The micro-level contains a set of agents owning behaviours that can be combined. The result of the combination impact the state of the system. The macro-level processes these influences to define a new state of the system which will impact the agents behaviours at the micro-level. This feedback loop separates behaviours on several levels. This approach is used to defined a demand and supply matching problem in micro-grid. This problem afford to manage a set of goals which currently are independently processed. Finally, an application is developed using MAS that ensures grid stability thanks to storage systems. This application was thought to be integrated to the approach detailed above. Secondly, a grid simulator id developed. This simulator allows dynamic control of devices. It is based on three main principles

Combined use of flexible ureteroscopic lithotripsy with micro-percutaneous nephrolithotomy in pediatric multiple kidney stones.

Science.gov (United States)

Li, Jun; Wang, Wenying; Du, Yuan; Tian, Ye

2018-03-28

We investigated the clinical value of treating pediatric multiple kidney stones with extensive distribution using flexible ureteroscopic lithotripsy (FUL) combined with micro-percutaneous nephrolithotomy (micro-PNL). In total, 21 pediatric patients with multiple renal calculi between May 2016 and June 2017 received FUL combined with micro-PNL. The group included 13 boys and eight girls; the patients' mean age was 3.8 years (range 1-8 years). The maximum stone diameter ranged from 1.0 to 1.5 cm. FUL was first performed in the lithotomy position to fragment stones that were located in the renal pelvis, and upper and mid-renal calyx. Patients were then moved to a prone position, and micro-PNL was performed to treat lower pole stones that could not be reached by the flexible ureteroscope during FUL. Percutaneous renal access to the lower calyx was achieved using a 4.8F "all-seeing needle" with ultrasound guidance, and stone fragmentation was performed with a 200-μm holmium laser at different settings to disintegrate 1- to 2-mm fragments. All 21 pediatric patients with multiple kidney stones underwent combined FUL and micro-PNL. The stone free rate (SFR) was 85.7% (18/21). The mean surgical time was 45 min (range 30-70 min). The mean volume of irrigation fluid used was 480 mL (range 300-1200 mL). The mean surgical time for FUL and micro-PNL was 31 min and 14 min, respectively, and the mean volume of fluid used for FUL and micro-PNL was 360 mL and 120 mL, respectively. According to the modified Clavien classification, grade 1 and 2 postoperative complications occurred in five and one patients, respectively. The mean decrease in the level of hemoglobin was 0.4 g/dL (0-0.7 g/dL), and no patients required a transfusion. The average hospital stay was 3 days (range 2-5 days). Combined FUL and micro-PNL is a safe, effective, and minimally invasive operation to remove multiple renal calculi with extensive distribution in children in selected cases. Copyright © 2018

Analysis of the Multi Strategy Goal Programming for Micro-Grid Based on Dynamic ant Genetic Algorithm

Science.gov (United States)

Qiu, J. P.; Niu, D. X.

Micro-grid is one of the key technologies of the future energy supplies. Take economic planning. reliability, and environmental protection of micro grid as a basis for the analysis of multi-strategy objective programming problems for micro grid which contains wind power, solar power, and battery and micro gas turbine. Establish the mathematical model of each power generation characteristics and energy dissipation. and change micro grid planning multi-objective function under different operating strategies to a single objective model based on AHP method. Example analysis shows that in combination with dynamic ant mixed genetic algorithm can get the optimal power output of this model.

Fabrication of Biochips with Micro Fluidic Channels by Micro End-milling and Powder Blasting

Directory of Open Access Journals (Sweden)

Dong Sam Park

2008-02-01

Full Text Available For microfabrications of biochips with micro fluidic channels, a large number of microfabrication techniques based on silicon or glass-based Micro-Electro-Mechanical System (MEMS technologies were proposed in the last decade. In recent years, for low cost and mass production, polymer-based microfabrication techniques by microinjection molding and micro hot embossing have been proposed. These techniques, which require a proper photoresist, mask, UV light exposure, developing, and electroplating as a preprocess, are considered to have some problems. In this study, we propose a new microfabrication technology which consists of micro end-milling and powder blasting. This technique could be directly applied to fabricate the metal mold without any preprocesses. The metal mold with micro-channels is machined by micro end-milling, and then, burrs generated in the end-milling process are removed by powder blasting. From the experimental results, micro end-milling combined with powder blasting could be applied effectively for fabrication of the injection mold of biochips with micro fluidic channels.

Life evaluation of FR-CV cable on thermal-radiation combined aging by micro-hardness

International Nuclear Information System (INIS)

Sugiyama, Masahiko; Ogata, Akimasa; Nitta, Makoto; Tani, Tsuneo; Yagi, Toshiaki; Seguchi, Tadao.

1996-01-01

For the evaluation of cable life for the application to nuclear facilities, the accelerated test was conducted by the combination of radiation and thermal oxidation. The degradation of FR-CV cable by the aging was monitored by tensile test, micro-hardness test, and gel-fraction measurement. The micro-hardness increased with the progress of degradation and related well with decrease of ultimate elongation of the sheath material, and was also reflected by the loss of plasticizer. The micro-hardness technique has a possibility to detect the degradation of cable as a non-destructive detector. (author)

The estimation of tax-benefit automatic stabilizers in Serbia: A combined micro-macro approach

Directory of Open Access Journals (Sweden)

Ranđelović Saša

2013-01-01

Full Text Available The large volatility of GDP due to the economic crisis, particularly in transition economies, has brought the issue of automatic stabilizers back into the focus of economic policy. The vast majority of empirical literature in this field relates to the estimation of the size of automatic stabilizers in developed countries, usually based on macroeconomic data. On the other hand empirical literature on this topic based on micro data, particularly for transition economies, is limited. This paper provides an evaluation of the size of automatic stabilizers in one transition economy (Serbia, by combining tax-benefit simulation modelling based on micro data and econometric methods based on macroeconomic data. The results show that, in the case of shock, around 17% of fall in market income would be absorbed by automatic stabilizers. Although the stabilizing effects of the tax-benefit system in Serbia are lower than in other European countries, the total size of automatic stabilizers is close to the average value in these countries, due to the higher elasticity of demand to income. The results also show that progressivity-enhancing income tax reform would only slightly increase automatic stabilizers, due to the large informal economy and the large share of agriculture in total households’ income.

Reprocessed and combined thorium fuel cycles in a PER system with a micro heterogeneous approaches

International Nuclear Information System (INIS)

Monteiro, Fabiana B.A.; Castro, Victor F.; Faria, Rochkhudson B. de; Pereira, Claubia; Fortini, Angela

2015-01-01

A micro heterogeneous approaches were used to study the behavior of reprocessed fuel spiked with thorium in a PWR fuel element considering (TRU-Th) cycle. The goal is to achieve a higher burnup using three different configurations to model the fuel element using SCALE 6.0. The reprocessed fuels were obtained using the ORIGEN 2.1 code from a spent PWR standard fuel (33,000 MWd/tHM burned), with 3.1% of initial enrichment. The spent fuel remained in the cooling pool for five years and then reprocessed using the UREX+ technique. Three configurations of micro heterogeneous approaches were analyzed, and the k inf and plutonium evolution during the burnup were evaluated. The preliminary results show that the behavior of advanced fuel based on transuranic elements spiked with thorium, and micro heterogeneous approach are satisfactory in PWRs, and the configuration that use a combination of Th and TRU (configuration 1) seems to be the most promising once has higher values for k inf during the burnup, compared with other configurations. (author)

Modeling and simulation of a residential micro-CHP system based on HT-PEMFC technology

DEFF Research Database (Denmark)

Arsalis, Alexandros; Nielsen, Mads Pagh; Kær, Søren Knudsen

2009-01-01

Combined-heat-and-power (CHP) technology is a well known and proved method to produce simultaneously power and heat at high efficiencies. This can be further improved by the introduction of a novel micro-CHP residential system based on High Temperature-Proton Exchange Membrane Fuel Cell (HT-PEMFC......). The HT-PEMFC (based on PBI-membrane technology) operates at temperatures near 200oC, and this can be an ideal match for cogeneration residential systems. The proposed system provides electric power, hot water, and space heating for a typical household (1-5 kWe, 5-10 kWth). The micro-CHP system...

Laser based micro forming and assembly.

Energy Technology Data Exchange (ETDEWEB)

MacCallum, Danny O' Neill; Wong, Chung-Nin Channy; Knorovsky, Gerald Albert; Steyskal, Michele D.; Lehecka, Tom (Pennsylvania State University, Freeport, PA); Scherzinger, William Mark; Palmer, Jeremy Andrew

2006-11-01

It has been shown that thermal energy imparted to a metallic substrate by laser heating induces a transient temperature gradient through the thickness of the sample. In favorable conditions of laser fluence and absorptivity, the resulting inhomogeneous thermal strain leads to a measurable permanent deflection. This project established parameters for laser micro forming of thin materials that are relevant to MESA generation weapon system components and confirmed methods for producing micrometer displacements with repeatable bend direction and magnitude. Precise micro forming vectors were realized through computational finite element analysis (FEA) of laser-induced transient heating that indicated the optimal combination of laser heat input relative to the material being heated and its thermal mass. Precise laser micro forming was demonstrated in two practical manufacturing operations of importance to the DOE complex: micrometer gap adjustments of precious metal alloy contacts and forming of meso scale cones.

Construction and Implementation of Teaching Mode for Digital Mapping based on Interactive Micro-course Technology

Directory of Open Access Journals (Sweden)

Ning Gao

2018-02-01

Full Text Available The era of “Internet + education” has caused reforms in teaching ideas, teaching modes, and learning styles. The emergence of micro-course technology provides new strategies for integrating learning styles. Task-driven digital mapping teaching, known as traditional classroom organization, has poor teaching effect due to single learning style and strategy. A new teaching mode for digital mapping was constructed in this study based on micro-course technology by combining interactive micro-course technology and digital mapping teaching to adapt to the demands of modern teaching. This teaching mode mainly included four modules, namely, micro-courseware, micro-video, micro-exercise, and micro-examination. It realized the hierarchical teaching of knowledge points in digital mapping course, simplification of basic principles, simulation of engineering cases, and self-evaluation of learning outcomes. The teaching mode was applied to 114 students from the Mapping Engineering Department of Henan University of Urban Construction. Results indicate that the proposed teaching mode based on interactive micro-course technology promoting the independent after-class learning of the students, stimulating their learning enthusiasm, enhancing their practical abilities of the students, and improving the effect of teaching. This mode of teaching provides a new concept for the teaching mode reform of other courses in mapping engineering.

Simple method based on intensity measurements for characterization of aberrations from micro-optical components.

Science.gov (United States)

Perrin, Stephane; Baranski, Maciej; Froehly, Luc; Albero, Jorge; Passilly, Nicolas; Gorecki, Christophe

2015-11-01

We report a simple method, based on intensity measurements, for the characterization of the wavefront and aberrations produced by micro-optical focusing elements. This method employs the setup presented earlier in [Opt. Express 22, 13202 (2014)] for measurements of the 3D point spread function, on which a basic phase-retrieval algorithm is applied. This combination allows for retrieval of the wavefront generated by the micro-optical element and, in addition, quantification of the optical aberrations through the wavefront decomposition with Zernike polynomials. The optical setup requires only an in-motion imaging system. The technique, adapted for the optimization of micro-optical component fabrication, is demonstrated by characterizing a planoconvex microlens.

All-solid-state flexible ultrathin micro-supercapacitors based on graphene.

Science.gov (United States)

Niu, Zhiqiang; Zhang, Li; Liu, Lili; Zhu, Bowen; Dong, Haibo; Chen, Xiaodong

2013-08-07

Flexible, compact, ultrathin and all-solid-state micro-supercapacitors are prepared by coating H₃PO₄/PVA gel electrolyte onto micro-patterned rGO interdigitated electrodes prepared by combining photolithography with selective electrophoretic deposition. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Control and experimental characterization of a methanol reformer for a 350W high temperature polymer electrolyte membrane fuel cell system

DEFF Research Database (Denmark)

Andreasen, Søren Juhl; Kær, Søren Knudsen; Jensen, Hans-Christian Becker

suited for reformer systems, where high CO tolerance is required. This enables the use fuels based on e.g. liquid alcohols. This work presents the control strategies of a methanol refoermer for a 350W HTPEM FC system. The system examined is the Serenergy H3-350 Mobile Battery Charger, an integrated......High temperature polymer electrolyte membrane(HTPEM) fuel cells offer many advantages due to their increased operating tempera-tures compared to similar Nafion-based membrane tech-nologies, that rely on the conductive abilities of liquid water. The polybenzimidazole (PBI) membranes are especially...

Application of combined micro-proton-induced X-ray emission and micro-synchrotron radiation X-ray fluorescence techniques for the characterization of impact materials around Barringer Meteor Crater

Energy Technology Data Exchange (ETDEWEB)

Uzonyi, I. [Institute of Nuclear Research of the Hungarian Academy of Sciences, Department of Electrostatic Accelerators, H-4026 Debrecen, Bem ter 18/C (Hungary)]. E-mail: uzonyi@atomki.hu; Szoeor, Gy. [Department of Mineralogy and Geology, University of Debrecen, H-4010 Debrecen, Egyetem ter 1 (Hungary); Vekemans, B. [Department of Chemistry, University of Antwerpen (UIA) Universiteitsplein 1, B-2610 Wilrijk (Belgium); Vincze, L. [Department of Chemistry, University of Antwerpen (UIA) Universiteitsplein 1, B-2610 Wilrijk (Belgium); Rozsa, P. [Department of Mineralogy and Geology, University of Debrecen, H-4010 Debrecen, Egyetem ter 1 (Hungary); Szabo, Gy. [Institute of Nuclear Research of the Hungarian Academy of Sciences, Department of Electrostatic Accelerators, H-4026 Debrecen, Bem ter 18/C (Hungary); Somogyi, A. [ID22, ESRF, 6 rue Jules Horowitz, BP 220, F-38043 Grenoble Cedex (France); Adams, F. [Department of Chemistry, University of Antwerpen (UIA) Universiteitsplein 1, B-2610 Wilrijk (Belgium); Kiss, A.Z. [Institute of Nuclear Research of the Hungarian Academy of Sciences, Department of Electrostatic Accelerators, H-4026 Debrecen, Bem ter 18/C (Hungary)

2004-10-08

A combined micro-PIXE and micro-SRXRF method has been used for the characterization of impact materials collected at the well-known Barringer Meteor Crater. Elemental maps were recorded and concentrations were determined by micro-PIXE method for the major constituents of samples. Micro-SRXRF technique was used for the complementary measurement of medium and high atomic number elements, especially the siderophilic ones. Altogether, approximately 40 elements were analyzed. These results elucidate many steps of the formation mechanism of the various impact-metamorphosed objects.

Treatment of oilfield wastewater by combined process of micro-electrolysis, Fenton oxidation and coagulation.

Science.gov (United States)

Zhang, Zhenchao

2017-12-01

In this study, a combined process was developed that included micro-electrolysis, Fenton oxidation and coagulation to treat oilfield fracturing wastewater. Micro-electrolysis and Fenton oxidation were applied to reduce chemical oxygen demand (COD) organic load and to enhance organic components gradability, respectively. Orthogonal experiment were employed to investigate the influence factors of micro-electrolysis and Fenton oxidation on COD removal efficiency. For micro-electrolysis, the optimum conditions were: pH, 3; iron-carbon dosage, 50 mg/L; mass ratio of iron-carbon, 2:3; reaction time, 60 min. For Fenton oxidation, a total reaction time of 90 min, a H 2 O 2 dosage of 12 mg/L, with a H 2 O 2 /Fe 2+ mole ratio of 30, pH of 3 were selected to achieve optimum oxidation. The optimum conditions in coagulation process: pH, cationic polyacrylamide dosage, mixing speed and time is 4.3, 2 mg/L, 150 rpm and 30 s, respectively. In the continuous treatment process under optimized conditions, the COD of oily wastewater fell 56.95%, 46.23%, 30.67%, respectively, from last stage and the total COD removal efficiency reached 83.94% (from 4,314 to 693 mg/L). In the overall treatment process under optimized conditions, the COD of oily wastewater was reduced from 4,314 to 637 mg/L, and the COD removal efficiency reached 85.23%. The contribution of each stage is 68.45% (micro-electrolysis), 24.07% (Fenton oxidation), 7.48% (coagulation), respectively. Micro-electrolysis is the uppermost influencing process on COD removal. Compared with the COD removal efficiency of three processes on raw wastewater under optimized conditions: the COD removal efficiency of single micro-electrolysis, single Fenton oxidation, single coagulation is 58.34%, 44.88% and 39.72%, respectively. Experiments proved the effect of combined process is marvelous and the overall water quality of the final effluent could meet the class III national wastewater discharge standard of petrochemical industry of China

Modeling and optimization of a 1 kWe HT-PEMFC-based micro-CHP residential system

DEFF Research Database (Denmark)

Arsalis, Alexandros; Nielsen, Mads Pagh; Kær, Søren Knudsen

2012-01-01

A high temperature-proton exchange membrane (HT-PEMFC)-based micro-combined-heat-and-power (CHP) residential system is designed and optimized, using a genetic algorithm (GA) optimization strategy. The proposed system consists of a fuel cell stack, steam methane reformer (SMR) reactor, water gas...

Adaptive Micro-Grid Operation Based on IEC 61850

Directory of Open Access Journals (Sweden)

Wei Deng

2015-05-01

Full Text Available Automatically identifying the new equipment after its integration and adjusting operation strategy to realize “plug and play” functionality are becoming essential for micro-grid operations. In order to improve and perfect the micro-grid “plug and play” function with the increased amount of equipment with different information protocols and more diverse system applications, this paper presents a solution for adaptive micro-grid operation based on IEC 61850, and proposes the design and specific implementation methods of micro-grid “plug and play” function and system operation mode conversion in detail, by using the established IEC 61850 information model of a micro-grid. Actual operation tests based on the developed IED and micro-grid test platform are performed to verify the feasibility and validity of the proposed solution. The tests results show that the solution can automatically identify the IEC 61850 information model of equipment after its integration, intelligently adjust the operation strategies to adapt to new system states and achieves a reliable system operation mode conversion.

Micro-electro-mechanical systems (MEMS)-based micro-scale direct methanol fuel cell development

International Nuclear Information System (INIS)

Yao, S.-C.; Tang Xudong; Hsieh, C.-C.; Alyousef, Yousef; Vladimer, Michael; Fedder, Gary K.; Amon, Cristina H.

2006-01-01

This paper describes a high-power density, silicon-based micro-scale direct methanol fuel cell (DMFC), under development at Carnegie Mellon. Major issues in the DMFC design include the water management and energy-efficient micro fluidic sub-systems. The air flow and the methanol circulation are both at a natural draft, while a passive liquid-gas separator removes CO 2 from the methanol chamber. An effective approach for maximizing the DMFC energy density, pumping the excess water back to the anode, is illustrated. The proposed DMFC contains several unique features: a silicon wafer with arrays of etched holes selectively coated with a non-wetting agent for collecting water at the cathode; a silicon membrane micro pump for pumping the collected water back to the anode; and a passive liquid-gas separator for CO 2 removal. All of these silicon-based components are fabricated using micro-electro-mechanical systems (MEMS)-based processes on the same silicon wafer, so that interconnections are eliminated, and integration efforts as well as post-fabrication costs are both minimized. The resulting fuel cell has an overall size of one cubic inch, produces a net output of 10 mW, and has an energy density three to five times higher than that of current lithium-ion batteries

Support schemes and ownership structures - the policy context for fuel cell based micro-combined heat and power

Science.gov (United States)

Schroeder, Sascha Thorsten; Costa, Ana; Obé, Elisabeth

In recent years, fuel cell based micro-combined heat and power (mCHP) has received increasing attention due to its potential contribution to European energy policy goals, i.e., sustainability, competitiveness and security of supply. Besides technical advances, regulatory framework and ownership structures are of crucial importance in order to achieve greater diffusion of the technology in residential applications. This paper analyses the interplay of policy and ownership structures for the future deployment of mCHP. Furthermore, it regards the three country cases Denmark, France and Portugal. Firstly, the implications of different kinds of support schemes on investment risk and the diffusion of a technology are explained conceptually. Secondly, ownership arrangements are addressed. Then, a cross-country comparison on present support schemes for mCHP and competing technologies discusses the national implementation of European legislation in Denmark, France and Portugal. Finally, resulting implications for ownership arrangements on the choice of support scheme are explained. From a conceptual point of view, investment support, feed-in tariffs and price premiums are the most appropriate schemes for fuel cell mCHP. This can be used for improved analysis of operational strategies. The interaction of this plethora of elements necessitates careful balancing from a private- and socio-economic point of view.

Modeling and parametric study of a 1 kWe HT-PEMFC-based residential micro-CHP system

DEFF Research Database (Denmark)

Arsalis, Alexandros; Nielsen, Mads Pagh; Kær, Søren Knudsen

2011-01-01

A detailed thermodynamic, kinetic and geometric model of a micro-CHP (Combined-Heatand-Power) residential system based on High Temperature-Proton Exchange Membrane Fuel Cell (HT-PEMFC) technology is developed, implemented and validated. HT-PEMFC technology is investigated as a possible candidate...

Longitudinal in vivo evaluation of bone regeneration by combined measurement of multi-pinhole SPECT and micro-CT for tissue engineering

Science.gov (United States)

Lienemann, Philipp S.; Metzger, Stéphanie; Kiveliö, Anna-Sofia; Blanc, Alain; Papageorgiou, Panagiota; Astolfo, Alberto; Pinzer, Bernd R.; Cinelli, Paolo; Weber, Franz E.; Schibli, Roger; Béhé, Martin; Ehrbar, Martin

2015-05-01

Over the last decades, great strides were made in the development of novel implants for the treatment of bone defects. The increasing versatility and complexity of these implant designs request for concurrent advances in means to assess in vivo the course of induced bone formation in preclinical models. Since its discovery, micro-computed tomography (micro-CT) has excelled as powerful high-resolution technique for non-invasive assessment of newly formed bone tissue. However, micro-CT fails to provide spatiotemporal information on biological processes ongoing during bone regeneration. Conversely, due to the versatile applicability and cost-effectiveness, single photon emission computed tomography (SPECT) would be an ideal technique for assessing such biological processes with high sensitivity and for nuclear imaging comparably high resolution (designed poly(ethylene glycol)-based hydrogels that release bone morphogenetic protein to guide the healing of critical sized calvarial bone defects. By combined in vivo longitudinal multi-pinhole SPECT and micro-CT evaluations we determine the spatiotemporal course of bone formation and remodeling within this synthetic hydrogel implant. End point evaluations by high resolution micro-CT and histological evaluation confirm the value of this approach to follow and optimize bone-inducing biomaterials.

Circuit Design of Surface Acoustic Wave Based Micro Force Sensor

Directory of Open Access Journals (Sweden)

Yuanyuan Li

2014-01-01

Full Text Available Pressure sensors are commonly used in industrial production and mechanical system. However, resistance strain, piezoresistive sensor, and ceramic capacitive pressure sensors possess limitations, especially in micro force measurement. A surface acoustic wave (SAW based micro force sensor is designed in this paper, which is based on the theories of wavelet transform, SAW detection, and pierce oscillator circuits. Using lithium niobate as the basal material, a mathematical model is established to analyze the frequency, and a peripheral circuit is designed to measure the micro force. The SAW based micro force sensor is tested to show the reasonable design of detection circuit and the stability of frequency and amplitude.

Micro/Nano manufacturing

DEFF Research Database (Denmark)

Tosello, Guido

2017-01-01

Micro- and nano-scale manufacturing has been the subject of an increasing amount of interest and research effort worldwide in both academia and industry over the past 10 years.Traditional (MEMS) manufacturing, but also precision manufacturing technologies have been developed to cover micro......-scale dimensions and accuracies. Furthermore, these fundamentally different technology ecosystems are currently combined in order to exploit strengths of both platforms. One example is the use of lithography-based technologies to establish nanostructures that are subsequently transferred to 3D geometries via...

Polymer-based blood vessel models with micro-temperature sensors in EVE

Science.gov (United States)

Mizoshiri, Mizue; Ito, Yasuaki; Hayakawa, Takeshi; Maruyama, Hisataka; Sakurai, Junpei; Ikeda, Seiichi; Arai, Fumihito; Hata, Seiichi

2017-04-01

Cu-based micro-temperature sensors were directly fabricated on poly(dimethylsiloxane) (PDMS) blood vessel models in EVE using a combined process of spray coating and femtosecond laser reduction of CuO nanoparticles. CuO nanoparticle solution coated on a PDMS blood vessel model are thermally reduced and sintered by focused femtosecond laser pulses in atmosphere to write the sensors. After removing the non-irradiated CuO nanoparticles, Cu-based microtemperature sensors are formed. The sensors are thermistor-type ones whose temperature dependences of the resistance are used for measuring temperature inside the blood vessel model. This fabrication technique is useful for direct-writing of Cu-based microsensors and actuators on arbitrary nonplanar substrates.

Removal of pigments from molasses wastewater by combining micro-electrolysis with biological treatment method.

Science.gov (United States)

Chen, Ben; Tian, Xiaofei; Yu, Lian; Wu, Zhenqiang

2016-12-01

Pigments in molasses wastewater (MWW) effluent, such as melanoidins, were considered as kinds of the most recalcitrant and hazardous colorant contaminants to the environment. In this study, de-coloring the MWW by a synergistic combination of micro-electrolysis with bio-treatment was performed. Aiming to a high de-colorization yield, levels of nutrition source supplies, MWW dilution ratio, and micro-electrolysis reaction time were optimized accordingly. For a diluted (50 %, v/v) MWW, an maximum overall de-colorization yield (97.1 ± 0.5 %, for absorbance at 475 nm) was achieved through the bio-electrolysis treatment. In electrolysis bio-treatment, the positive effect of micro-electrolysis was also revealed by a promoted growth of fungal biomass as well as activities of ligninolytic enzymes. Activities of lignin peroxidase, manganese peroxidase, and laccase were promoted by 111.2, 103.9, and 7.7 %, respectively. This study also implied that the bio-treatment and the micro-electrolysis had different efficiencies on removal of pigments with distinct polarities.

Development and blind clinical validation of a microRNA based predictor of response to treatment with R-CHO(E)P in DLBCL

DEFF Research Database (Denmark)

Knudsen, Steen; Hother, Christoffer; Grønbæk, Kirsten

2015-01-01

MicroRNAs (miRNA) are a group of short noncoding RNAs that regulate gene expression at the posttranscriptional level. It has been shown that microRNAs are independent predictors of outcome in patients with diffuse large B-cell lymphoma (DLBCL) treated with the drug combination R-CHOP. Based on th...

Planning of micro-combined heat and power systems in the Portuguese scenario

International Nuclear Information System (INIS)

Monteiro, Eliseu; Moreira, Nuno Afonso; Ferreira, Sergio

2009-01-01

High efficiency cogeneration is seen by the European Commission as part of the solution to increase energy efficiency and improve security of supply in the internal energy markets. Portuguese residential sector has an estimated technical market potential of around 500 MW e for cogeneration of e in size. Additionally, in Portugal there is a specific law for power production in low voltage, where at least 50% of the produced electric energy must be own consumed and the maximum power delivered to the power utility should be less than 150 kW e . Therefore, generic application tools cannot be applied in this regard. In this work, we develop the MicroG model for planning micro-CHP plants in agreement with the Portuguese energy legal framework. The model is able to design, evaluate and optimize from the techno-economic point of view any micro-CHP plant. MicroG appeals to some data bases, such as micro-cogeneration technologies and power consumption profiles that are also described. In addition, a practical case on a gym is considered to show all the functionalities of the model. The developed model has proven to be extremely useful from the practical point of view. This model could help the development of the micro-CHP Portuguese market, which in turns contributes to accomplish the targets of Kyoto protocol and EU cogeneration Directive. Other improvements to MicroG model can be made in order to enlarge the range of application to other micro-cogeneration technologies and to accomplish with the CO 2 emissions trading

Planning of micro-combined heat and power systems in the Portuguese scenario

Energy Technology Data Exchange (ETDEWEB)

Monteiro, Eliseu; Moreira, Nuno Afonso [CITAB, University of Tras-os-Montes e Alto Douro, P-5000-911 Vila Real (Portugal); Ferreira, Sergio [R and D Department, Tecaprod S.A. (Portugal)

2009-03-15

High efficiency cogeneration is seen by the European Commission as part of the solution to increase energy efficiency and improve security of supply in the internal energy markets. Portuguese residential sector has an estimated technical market potential of around 500 MW{sub e} for cogeneration of <150 kW{sub e} in size. Additionally, in Portugal there is a specific law for power production in low voltage, where at least 50% of the produced electric energy must be own consumed and the maximum power delivered to the power utility should be less than 150 kW{sub e}. Therefore, generic application tools cannot be applied in this regard. In this work, we develop the MicroG model for planning micro-CHP plants in agreement with the Portuguese energy legal framework. The model is able to design, evaluate and optimize from the techno-economic point of view any micro-CHP plant. MicroG appeals to some data bases, such as micro-cogeneration technologies and power consumption profiles that are also described. In addition, a practical case on a gym is considered to show all the functionalities of the model. The developed model has proven to be extremely useful from the practical point of view. This model could help the development of the micro-CHP Portuguese market, which in turns contributes to accomplish the targets of Kyoto protocol and EU cogeneration Directive. Other improvements to MicroG model can be made in order to enlarge the range of application to other micro-cogeneration technologies and to accomplish with the CO{sub 2} emissions trading. (author)

Modeling and simulation for micro DC motor based on simulink

Science.gov (United States)

Shen, Hanxin; Lei, Qiao; Chen, Wenxiang

2017-09-01

The micro DC motor has a large market demand but there is a lack of theoretical research for it. Through detailed analysis of the commutation process of micro DC motor commutator, based on micro DC motor electromagnetic torque equation and mechanical torque equation, with the help of Simulink toolkit, a triangle connection micro DC motor simulation model is established. By using the model, a sample micro DC motor are simulated, and an experimental measurements has been carried on the sample micro DC motor. It is found that the simulation results are consistent with theoretical analysis and experimental results.

Inline chemical process analysis in micro-plants based on thermoelectric flow and impedimetric sensors

International Nuclear Information System (INIS)

Jacobs, T; Kutzner, C; Hauptmann, P; Kropp, M; Lang, W; Brokmann, G; Steinke, A; Kienle, A

2010-01-01

In micro-plants, as used in chemical micro-process engineering, an integrated inline analytics is regarded as an important factor for the development and optimization of chemical processes. Up to now, there is a lack of sensitive, robust and low-priced micro-sensors for monitoring mixing and chemical conversion in micro-fluidic channels. In this paper a novel sensor system combining an impedimetric sensor and a novel pressure stable thermoelectric flow sensor for monitoring chemical reactions in micro-plants is presented. The CMOS-technology-based impedimetric sensor mainly consists of two capacitively coupled interdigital electrodes on a silicon chip. The thermoelectric flow sensor consists of a heater in between two thermopiles on a perforated membrane. The pulsed and constant current feeds of the heater were analyzed. Both sensors enable the analysis of chemical conversion by means of changes in the thermal and electrical properties of the liquid. The homogeneously catalyzed synthesis of n-butyl acetate as a chemical model system was studied. Experimental results revealed that in an overpressure regime, relative changes of less than 1% in terms of thermal and electrical properties can be detected. Furthermore, the transition from one to two liquid phases accompanied by the change in slug flow conditions could be reproducibly detected

Optimal operation of a micro-combined cooling, heating and power system driven by a gas engine

International Nuclear Information System (INIS)

Kong, X.Q.; Wang, R.Z.; Li, Y.; Huang, X.H.

2009-01-01

The objective of this paper is to investigate the problem of energy management and optimal operation of cogeneration system for micro-combined cooling, heating and power production (CCHP). The energy system mainly consists of a gas engine, an adsorption chiller, a gas boiler, a heat exchanger and an electric chiller. On the basis of an earlier experimental research of the micro-CCHP system, a non-linear-programming cost-minimization optimization model is presented to determine the optimum operational strategies for the system. It is shown that energy management and optimal operation of the micro-CCHP system is dependent upon load conditions to be satisfied and energy cost. In view of energy cost, it would not be optimal to operate the gas engine when the electric-to-gas cost ratio (EGCR) is very low. With higher EGCR, the optimum operational strategy of the micro-CCHP system is independent of energy cost

Application of an improved operational strategy for a high temperature-proton exchange membrane fuel cell-based micro-combined heat and power system for Danish single-family households

DEFF Research Database (Denmark)

Arsalis, Alexandros; Nielsen, Mads Pagh; Kær, Søren Knudsen

2013-01-01

be justified as compared to other micro-CHP system technologies. The most important findings of this research study indicate that in comparison to non-fuel cell-based micro-CHP systems, such as Stirling Engine-based systems, the proposed system has significantly higher efficiencies. Moreover, the lower heat...

Carbon-based micro-ball and micro-crystal deposition using filamentary pulsed atmospheric pressure plasma

International Nuclear Information System (INIS)

Pothiraja, Ramasamy; Bibinov, Nikita; Awakowicz, Peter

2014-01-01

Thin plasma filaments are produced by the propagation of ionization waves from a spiked driven electrode in a quartz tube in an argon/methane gas mixture (2400 sccm/2 sccm) at atmospheric pressure. The position of the touch point of filaments on the substrate surface is controlled in our experiment by applying various suitable substrate configurations and geometries of the grounded electrode. The gas conditions at the touch point are varied from argon to ambient air. Based on microphotography and discharge current waveforms, the duration of the filament touching the substrate is estimated to be about one microsecond. Carbon-based materials are deposited during this time at the touch points on the substrate surface. Micro-balls are produced if the filament touch points are saved from ambient air by the argon flow. Under an air admixture, micro-crystals are formed. The dimension of both materials is approximately one micrometre (0.5–2 µm) and corresponds to about 10 10 –10 12 carbon atoms. Neither the diffusion of neutral species nor drift of ions can be reason for the formation of such a big micro-material during this short period of filament–substrate interaction. It is possible that charged carbon-based materials are formed in the plasma channel and transported to the surface of the substrate. The mechanism of this transport and characterization of micro-materials, which are formed under different gas conditions in our experiment, will be studied in the future. (paper)

Volumetric quantification of bone-implant contact using micro-computed tomography analysis based on region-based segmentation.

Science.gov (United States)

Kang, Sung-Won; Lee, Woo-Jin; Choi, Soon-Chul; Lee, Sam-Sun; Heo, Min-Suk; Huh, Kyung-Hoe; Kim, Tae-Il; Yi, Won-Jin

2015-03-01

We have developed a new method of segmenting the areas of absorbable implants and bone using region-based segmentation of micro-computed tomography (micro-CT) images, which allowed us to quantify volumetric bone-implant contact (VBIC) and volumetric absorption (VA). The simple threshold technique generally used in micro-CT analysis cannot be used to segment the areas of absorbable implants and bone. Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images. The three-dimensional VBIC and VA of the absorbable implant were then calculated over the entire volume of the implant. Two-dimensional (2D) bone-implant contact (BIC) and bone area (BA) were also measured based on the conventional histomorphometric method. VA and VBIC increased significantly with as the healing period increased (pimplants using micro-CT analysis using a region-based segmentation method.

Novel MEMS-based fabrication technology of micro solenoid-type inductor

International Nuclear Information System (INIS)

Uchiyama, S; Yang, Z Q; Takagi, H; Itoh, T; Maeda, R; Zhang, Y; Toda, A; Hayase, M

2013-01-01

Solenoid configuration of micro inductor, which has advantages of high quality factor and low loss, is needed in micro energy and power electronics applications but it is difficult to prepare using conventional microfabrication processes. In this work, we present a new microelectromechanical systems-based technology of micro solenoid-type inductor by a newly developed cylindrical projection photolithography method. Direct electroplating process of copper film on coil patterns was also successfully developed for achieving thick windings so that thick photoresist-based electroplating molds are not needed. Micro solenoid-type inductor prototypes of the winding pitch of about 40 µm, the winding number of 20 and 50, and the winding thickness of about 14 µm, were successfully fabricated on a 1 mm diameter glass capillary. The prepared 20-turn and 50-turn micro inductors were of inductance of 69 and 205 nH at 30 MHz, respectively. (paper)

Methanol Reformer System Modeling and Control using an Adaptive Neuro-Fuzzy Inference System approach

DEFF Research Database (Denmark)

Justesen, Kristian Kjær; Ehmsen, Mikkel Præstholm; Andersen, John

2012-01-01

This work presents the experimental study and modelling of a methanol reformer system for a high temperature polymer electrolyte membrane (HTPEM) fuel cell stack. The analyzed system is a fully integrated HTPEM fuel cell system with a DC/DC control output able to be used as e.g. a mobile battery...... charger. The advantages of using a HTPEM methanol reformer is that the high quality waste heat can be used as a system heat input to heat and evaporate the input methanol/water mixture which afterwards is catalytically converted into a hydrogen rich gas usable in the high CO tolerant HTPEM fuel cells....... Creating a fuel cell system able to use a well known and easily distributable liquid fuel such as methanol is a good choice in some applications such as range extenders for electric vehicles as an alternative to compressed hydrogen. This work presents a control strategy called Current Correction...

Polytetrafluorethylene film-based liquid-three phase micro extraction coupled with differential pulse voltammetry for the determination of atorvastatin calcium.

Science.gov (United States)

Ensafi, Ali A; Khoddami, Elaheh; Rezaei, Behzad

2013-01-01

In this paper, we describe a new combination method based on polytetrafluorethylene (PTFE) film-based liquid three-phase micro extraction coupled with differential pulse voltammetry (DPV) for the micro extraction and quantification of atorvastatin calcium (ATC) at the ultra-trace level. Different factors affecting the liquid-three phases micro extraction of atorvastatin calcium, including organic solvent, pH of the donor and acceptor phases, concentration of salt, extraction time, stirring rate and electrochemical factors, were investigated, and the optimal extraction conditions were established. The final stable signal was achieved after a 50 min extraction time, which was used for analytical applications. An enrichment factor of 21 was achieved, and the relative standard deviation (RSD) of the method was 4.5% (n = 4). Differential pulse voltammetry exhibited two wide linear dynamic ranges of 20.0-1000.0 pmol L(-1) and 0.001-11.0 µmol L(-1) of ATC. The detection limit was found to be 8.1 pmol L(-1) ATC. Finally, the proposed method was used as a new combination method for the determination of atorvastatin calcium in real samples, such as human urine and plasma.

Fabrication of Micro Components by Electrochemical Deposition

DEFF Research Database (Denmark)

Tang, Peter Torben

The main issue of this thesis is the combination of electrochemical deposition of metals and micro machining. Processes for electroplating and electroless plating of nickel and nickel alloys have been developed and optimised for compatibility with microelectronics and silicon based micromechanics...... of electrochemical machining and traditional machining is compared to micro machining techniques as performed in the field of microelectronics. Various practical solutions and equipment for electrochemical deposition of micro components are demonstrated, as well as the use and experience obtained utilising...

Modeling and off-design performance of a 1 kWe HT-PEMFC (high temperature-proton exchange membrane fuel cell)-based residential micro-CHP (combined-heat-and-power) system for Danish single-family households

DEFF Research Database (Denmark)

Arsalis, Alexandros; Nielsen, Mads Pagh; Kær, Søren Knudsen

2011-01-01

A novel proposal for the modeling and operation of a micro-CHP (combined-heat-and-power) residential system based on HT-PEMFC (High Temperature-Proton Exchange Membrane Fuel Cell) technology is described and analyzed to investigate its commercialization prospects. An HT-PEMFC operates at elevated...... temperatures, as compared to Nafion-based PEMFCs and therefore can be a significant candidate for cogeneration residential systems. The proposed system can provide electric power, hot water, and space heating for a typical Danish single-family household. A complete fuel processing subsystem, with all necessary...

Design for micro-combined cooling, heating and power systems stirling engines and renewable power systems

CERN Document Server

2015-01-01

‘Design for Micro-Combined Cooling, Heating & Power Systems’ provides a manual for the technical and structural design of systems for supplying decentralised energy in residential buildings. It presents the micro-combined cooling, heating & power systems Stirling engines & renewable energy sources (mCCHP-SE-RES) systems in an accessible manner both for the public at large, and for professionals who conceive, design or commercialise such systems or their components.  The high performance levels of these systems are demonstrated within the final chapter by the results of an experiment in which a house is equipped with a mCCHP-SE-RES system. The reader is also familiarized with the conceptual, technical and legal aspects of modern domestic energy systems; the components that constitute these systems; and advanced algorithms for achieving the structural and technical design of such systems. In residential buildings, satisfying demands of durable development has gradually evolved from necessity to...

Optimal stochastic coordinated scheduling of proton exchange membrane fuel cell-combined heat and power, wind and photovoltaic units in micro grids considering hydrogen storage

International Nuclear Information System (INIS)

Bornapour, Mosayeb; Hooshmand, Rahmat-Allah; Khodabakhshian, Amin; Parastegari, Moein

2017-01-01

Highlights: •Stochastic model is proposed for coordinated scheduling of renewable energy sources. •The effect of combined heat and power is considered. •Hydrogen storage is considered for fuel cells. •Maximizing profits of micro grid is considered as objective function. •Considering the uncertainties of problem lead to profit increasing. -- Abstract: Nowadays, renewable energy sources and combined heat and power units are extremely used in micro grids, so it is necessary to schedule these units to improve the performance of the system. In this regard, a stochastic model is proposed in this paper to schedule proton exchange membrane fuel cell-combined heat and power, wind turbines, and photovoltaic units coordinately in a micro grid while considering hydrogen storage. Hydrogen storage strategy is considered for the operation of proton exchange membrane fuel cell-combined heat and power units. To consider stochastic generation of renewable energy source units in this paper, a scenario-based method is used. In this method, the uncertainties of electrical market price, the wind speed, and solar irradiance are considered. This stochastic scheduling problem is a mixed integer- nonlinear programming which considers the proposed objective function and variables of coordinated scheduling of PEMFC-CHP, wind turbines and photovoltaic units. It also considers hydrogen storage strategy and converts it to a mixed integer nonlinear problem. In this study a modified firefly algorithm is used to solve the problem. This method is examined on modified 33-bus distributed network as a MG for its performance.

FPGA-Based HD Camera System for the Micropositioning of Biomedical Micro-Objects Using a Contactless Micro-Conveyor

Directory of Open Access Journals (Sweden)

Elmar Yusifli

2017-03-01

Full Text Available With recent advancements, micro-object contactless conveyers are becoming an essential part of the biomedical sector. They help avoid any infection and damage that can occur due to external contact. In this context, a smart micro-conveyor is devised. It is a Field Programmable Gate Array (FPGA-based system that employs a smart surface for conveyance along with an OmniVision complementary metal-oxide-semiconductor (CMOS HD camera for micro-object position detection and tracking. A specific FPGA-based hardware design and VHSIC (Very High Speed Integrated Circuit Hardware Description Language (VHDL implementation are realized. It is done without employing any Nios processor or System on a Programmable Chip (SOPC builder based Central Processing Unit (CPU core. It keeps the system efficient in terms of resource utilization and power consumption. The micro-object positioning status is captured with an embedded FPGA-based camera driver and it is communicated to the Image Processing, Decision Making and Command (IPDC module. The IPDC is programmed in C++ and can run on a Personal Computer (PC or on any appropriate embedded system. The IPDC decisions are sent back to the FPGA, which pilots the smart surface accordingly. In this way, an automated closed-loop system is employed to convey the micro-object towards a desired location. The devised system architecture and implementation principle is described. Its functionality is also verified. Results have confirmed the proper functionality of the developed system, along with its outperformance compared to other solutions.

Optical assembly of bio-hybrid micro-robots.

Science.gov (United States)

Barroso, Álvaro; Landwerth, Shirin; Woerdemann, Mike; Alpmann, Christina; Buscher, Tim; Becker, Maike; Studer, Armido; Denz, Cornelia

2015-04-01

The combination of micro synthetic structures with bacterial flagella motors represents an actual trend for the construction of self-propelled micro-robots. The development of methods for fabrication of these bacteria-based robots is a first crucial step towards the realization of functional miniature and autonomous moving robots. We present a novel scheme based on optical trapping to fabricate living micro-robots. By using holographic optical tweezers that allow three-dimensional manipulation in real time, we are able to arrange the building blocks that constitute the micro-robot in a defined way. We demonstrate exemplarily that our method enables the controlled assembly of living micro-robots consisting of a rod-shaped prokaryotic bacterium and a single elongated zeolite L crystal, which are used as model of the biological and abiotic components, respectively. We present different proof-of-principle approaches for the site-selective attachment of the bacteria on the particle surface. The propulsion of the optically assembled micro-robot demonstrates the potential of the proposed method as a powerful strategy for the fabrication of bio-hybrid micro-robots.

Micro-droplet formation via 3D printed micro channel

Science.gov (United States)

Jian, Zhen; Zhang, Jiaming; Li, Erqiang; Thoroddsen, Sigurdur T.

2016-11-01

Low cost, fast-designed and fast-fabricated 3D micro channel was used to create micro-droplets. Capillary with an outer diameter of 1.5 mm and an inner diameter of 150 μm was inserted into a 3D printed cylindrical channel with a diameter of 2 mm . Flow rate of the two inlets, insert depth, liquid (density, viscosity and surface tension) and solid (roughness, contact angle) properties all play a role in the droplet formation. Different regimes - dripping, jetting, unstable state - were observed in the micro-channel on varying these parameters. With certain parameter combinations, successive formation of micro-droplets with equal size was observed and its size can be much smaller than the smallest channel size. Based on our experimental results, the droplet formation via 3D printed micro T-junction was investigated through direct numerical simulations with a code called Gerris. Reynolds numbers Re = ρUL / μ and Weber numbers We = ρU2 L / σ of the two liquids were introduced to measure the liquid effect. The parameter regime where different physical dynamics occur was studied and the regime transition was observed with certain threshold values. Qualitative and quantitative analysis were performed as well between simulations and experiments.

Recent advances in graphene-based planar micro-supercapacitors for on-chip energy storage

Institute of Scientific and Technical Information of China (English)

Zhong-Shuai Wu; Xinliang Feng; Hui-Ming Cheng

2014-01-01

The current development trend towards miniaturized portable electronic devices has signiicantly increased the demand for ultrathin, lexible and sustainable on-chip micro-supercapacitors that have enormous potential to complement, or even to replace, micro-bateries and electrolytic capacitors. In this regard,graphene-based micro-supercapacitors with a planar geometry are promising micro-electrochemical energy-storage devices that can take full advantage of planar coniguration and unique features of graphene.his review summarizes the latest advances in on-chip graphene-based planar interdigital micro-supercapacitors, from the history of their development, representative graphene-based materials(graphene sheets, graphene quantum dots and graphene hybrids) for their manufacture, typical microfabrication strategies(photolithography techniques, electrochemical methods, laser writing, etc.),electrolyte(aqueous, organic, ionic and gel), to device coniguration(symmetric and asymmetric). Finally,the perspectives and possible development directions of future graphene-based micro-supercapacitors are briely discussed.

Experimental analysis of micro-cogeneration units based on reciprocating internal combustion engine

Energy Technology Data Exchange (ETDEWEB)

Possidente, R.; Sibilio, S. [Seconda Universita di Napoli, Dipartimento di Storia e Processi dell' ambiente Antropizzato (DiSPAMA), Borgo San Lorenzo, Aversa, CE (Italy); Roselli, C.; Sasso, M. [Dipartimento di Ingegneria, Universita degli Studi del Sannio, Benevento (Italy)

2006-07-01

The cogeneration, or the combined production of electric and/or mechanical and thermal energy, is a well-established technology now, which has important environmental benefits and has been noted by the European Community as one of the first elements to save primary energy, to avoid network losses and to reduce the greenhouse gas emissions. In particular, our interest will be focused on the micro-cogeneration, MCHP (electric power up to 15 kW), which represents a valid and interesting application of this technology which refers, above all, to residential and light commercial users [M. Dentice d'Accadia, M. Sasso, S. Sibilio, Cogeneration for energy saving in household applications, in: P. Bertoldi, A. Ricci, A. de Almeida (Eds.), Energy Efficiency in Household Appliances and Lighting, Springer, Berlin, 2001, pp. 210-221; Directive 2004/8/EC of the European Parliament and of the Council of the 11 February 2004 on the promotion of cogeneration based on the useful heat demand in the internal energy market and amending Directive 92/42/EEC, Official Journal of the European Union (2004)]. In particular, our work group started a R and D programme on micro-cogeneration in 1995: a laboratory, equipped with the most common appliances (washing-machine, dishwasher, storage water heater, ...), has been built and some MCHP prototypes have been tested too. In this article, the results of an intense experimental activity on three different micro-cogenerators, one of them made in Japan and in a pre-selling phase, are reported. In a previous paper a detailed analysis of the test facility, with the description of the equipment and the data acquisition systems, can be found [M. Dentice d'Accadia, M. Sasso, S. Sibilio, R. Vanoli, Micro-combined heat and power in residential and light commercial applications, Applied Thermal Engineering 23 (2003) 1247-1259]. A typical 3-E (Energetic, Economic and Environmental) approach has been performed to compare the proposed energy system

The fabrication and hydrophobic property of micro-nano patterned surface on magnesium alloy using combined sparking sculpture and etching route

Energy Technology Data Exchange (ETDEWEB)

Wu, Yunfeng [Institute for Advanced Ceramics, Harbin Institute of Technology, Harbin 150001 (China); Wang, Yaming, E-mail: wangyaming@hit.edu.cn [Institute for Advanced Ceramics, Harbin Institute of Technology, Harbin 150001 (China); Liu, Hao [Institute for Advanced Ceramics, Harbin Institute of Technology, Harbin 150001 (China); Liu, Yan [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China); Guo, Lixin; Jia, Dechang; Ouyang, Jiahu; Zhou, Yu [Institute for Advanced Ceramics, Harbin Institute of Technology, Harbin 150001 (China)

2016-12-15

Highlights: • A hydrophobic micro-nano roughness surface on magnesium was fabricated. • Micro-nano structure derives from duplicating ‘over growth’ regions by MAO. • 7–9 μm micro-scale big pores insetting with nano-scale fine pores were fabricated. • Hydrophobicity of micro-nano surface was improved by chemical decoration and stearic treatment. - Abstract: Magnesium alloy with micro-nano structure roughness surface, can serve as the loading reservoirs of medicine capsule and industrial lubricating oil, or mimic ‘lotus leaf’ hydrophobic surface, having the potential applications in medical implants, automobile, aerospace and electronic products, etc. Herein, we propose a novel strategy to design a micro-nano structure roughness surface on magnesium alloy using combined microarc sparking sculpture and etching in CrO{sub 3} aqueous solution. A hydrophobic surface (as an applied example) was further fabricated by chemical decorating on the obtained patterned magnesium alloy surface to enhance the corrosion resistance. The results show that the combined micro-nano structure of 7–9 μm diameter big pores insetting with nano-scale fine pores was duplicated after etched the sparking sculptured ‘over growth’ oxide regions towards the magnesium substrate. The micro-nano structure surface was chemically decorated using AgNO{sub 3} and stearic acid, which enables the contact angle increased from 60° to 146.8°. The increasing contact angle is mainly attributed to the micro-nano structure and the chemical composition. The hydrophobic surface of magnesium alloy improved the corrosion potential from −1.521 V of the bare magnesium to −1.274 V. Generally, the sparking sculpture and then etching route demonstrates a low-cost, high-efficacy method to fabricate a micro-nano structure hydrophobic surface on magnesium alloy. Furthermore, our research on the creating of micro-nano structure roughness surface and the hydrophobic treatment can be easily

The fabrication and hydrophobic property of micro-nano patterned surface on magnesium alloy using combined sparking sculpture and etching route

International Nuclear Information System (INIS)

Wu, Yunfeng; Wang, Yaming; Liu, Hao; Liu, Yan; Guo, Lixin; Jia, Dechang; Ouyang, Jiahu; Zhou, Yu

2016-01-01

Highlights: • A hydrophobic micro-nano roughness surface on magnesium was fabricated. • Micro-nano structure derives from duplicating ‘over growth’ regions by MAO. • 7–9 μm micro-scale big pores insetting with nano-scale fine pores were fabricated. • Hydrophobicity of micro-nano surface was improved by chemical decoration and stearic treatment. - Abstract: Magnesium alloy with micro-nano structure roughness surface, can serve as the loading reservoirs of medicine capsule and industrial lubricating oil, or mimic ‘lotus leaf’ hydrophobic surface, having the potential applications in medical implants, automobile, aerospace and electronic products, etc. Herein, we propose a novel strategy to design a micro-nano structure roughness surface on magnesium alloy using combined microarc sparking sculpture and etching in CrO_3 aqueous solution. A hydrophobic surface (as an applied example) was further fabricated by chemical decorating on the obtained patterned magnesium alloy surface to enhance the corrosion resistance. The results show that the combined micro-nano structure of 7–9 μm diameter big pores insetting with nano-scale fine pores was duplicated after etched the sparking sculptured ‘over growth’ oxide regions towards the magnesium substrate. The micro-nano structure surface was chemically decorated using AgNO_3 and stearic acid, which enables the contact angle increased from 60° to 146.8°. The increasing contact angle is mainly attributed to the micro-nano structure and the chemical composition. The hydrophobic surface of magnesium alloy improved the corrosion potential from −1.521 V of the bare magnesium to −1.274 V. Generally, the sparking sculpture and then etching route demonstrates a low-cost, high-efficacy method to fabricate a micro-nano structure hydrophobic surface on magnesium alloy. Furthermore, our research on the creating of micro-nano structure roughness surface and the hydrophobic treatment can be easily extended to the

Volumetric quantification of bone-implant contact using micro-computed tomography analysis based on region-based segmentation

Energy Technology Data Exchange (ETDEWEB)

Kang, Sung Won; Lee, Woo Jin; Choi, Soon Chul; Lee, Sam Sun; Heo, Min Suk; Huh, Kyung Hoe; Kim, Tae Il; Yi, Won Ji [Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

2015-03-15

We have developed a new method of segmenting the areas of absorbable implants and bone using region-based segmentation of micro-computed tomography (micro-CT) images, which allowed us to quantify volumetric bone-implant contact (VBIC) and volumetric absorption (VA). The simple threshold technique generally used in micro-CT analysis cannot be used to segment the areas of absorbable implants and bone. Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images. The three-dimensional VBIC and VA of the absorbable implant were then calculated over the entire volume of the implant. Two-dimensional (2D) bone-implant contact (BIC) and bone area (BA) were also measured based on the conventional histomorphometric method. VA and VBIC increased significantly with as the healing period increased (p<0.05). VBIC values were significantly correlated with VA values (p<0.05) and with 2D BIC values (p<0.05). It is possible to quantify VBIC and VA for absorbable implants using micro-CT analysis using a region-based segmentation method.

Volumetric quantification of bone-implant contact using micro-computed tomography analysis based on region-based segmentation

International Nuclear Information System (INIS)

Kang, Sung Won; Lee, Woo Jin; Choi, Soon Chul; Lee, Sam Sun; Heo, Min Suk; Huh, Kyung Hoe; Kim, Tae Il; Yi, Won Ji

2015-01-01

We have developed a new method of segmenting the areas of absorbable implants and bone using region-based segmentation of micro-computed tomography (micro-CT) images, which allowed us to quantify volumetric bone-implant contact (VBIC) and volumetric absorption (VA). The simple threshold technique generally used in micro-CT analysis cannot be used to segment the areas of absorbable implants and bone. Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images. The three-dimensional VBIC and VA of the absorbable implant were then calculated over the entire volume of the implant. Two-dimensional (2D) bone-implant contact (BIC) and bone area (BA) were also measured based on the conventional histomorphometric method. VA and VBIC increased significantly with as the healing period increased (p<0.05). VBIC values were significantly correlated with VA values (p<0.05) and with 2D BIC values (p<0.05). It is possible to quantify VBIC and VA for absorbable implants using micro-CT analysis using a region-based segmentation method.

Electrochemical characterization of a polybenzimidazole-based high temperature proton exchange membrane unit cell

DEFF Research Database (Denmark)

Jespersen, Jesper Lebæk; Schaltz, Erik; Kær, Søren Knudsen

2009-01-01

This work constitutes detailed EIS (Electrochemical Impedance Spectroscopy) measurements on a PBIbased HT-PEM unit cell. By means of EIS the fuel cell is characterized in several modes of operation by varying the current density, temperature and the stoichiometry of the reactant gases. Using...

Experimental Analysis of the Effects of CO and CO2 on High Temperature PEM Fuel Cell Performance using Electrochemical Impedance Spectroscopy

DEFF Research Database (Denmark)

Andreasen, Søren Juhl; Vang, Jakob Rabjerg

2010-01-01

The use of high temperature PEM (HTPEM) fuel cells running on reformate gas shows comparable performance to HTPEM fuel cells running on pure hydrogen, even when running at high levels of CO, as long as high operating temperatures are ensured. The increased operating temperatures of these types of...

400 W High Temperature PEM Fuel Cell Stack Test

DEFF Research Database (Denmark)

Andreasen, Søren Juhl; Kær, Søren Knudsen

2006-01-01

This work demonstrates the operation of a 30 cell high temperature PEM (HTPEM) fuel cell stack. This prototype stack has been developed at the Institute of Energy Technology, Aalborg University, as a proof-of-concept for a low pressure cathode air cooled HTPEM stack. The membranes used are Celtec...

The fabrication and hydrophobic property of micro-nano patterned surface on magnesium alloy using combined sparking sculpture and etching route

Science.gov (United States)

Wu, Yunfeng; Wang, Yaming; Liu, Hao; Liu, Yan; Guo, Lixin; Jia, Dechang; Ouyang, Jiahu; Zhou, Yu

2016-12-01

Magnesium alloy with micro-nano structure roughness surface, can serve as the loading reservoirs of medicine capsule and industrial lubricating oil, or mimic 'lotus leaf' hydrophobic surface, having the potential applications in medical implants, automobile, aerospace and electronic products, etc. Herein, we propose a novel strategy to design a micro-nano structure roughness surface on magnesium alloy using combined microarc sparking sculpture and etching in CrO3 aqueous solution. A hydrophobic surface (as an applied example) was further fabricated by chemical decorating on the obtained patterned magnesium alloy surface to enhance the corrosion resistance. The results show that the combined micro-nano structure of 7-9 μm diameter big pores insetting with nano-scale fine pores was duplicated after etched the sparking sculptured 'over growth' oxide regions towards the magnesium substrate. The micro-nano structure surface was chemically decorated using AgNO3 and stearic acid, which enables the contact angle increased from 60° to 146.8°. The increasing contact angle is mainly attributed to the micro-nano structure and the chemical composition. The hydrophobic surface of magnesium alloy improved the corrosion potential from -1.521 V of the bare magnesium to -1.274 V. Generally, the sparking sculpture and then etching route demonstrates a low-cost, high-efficacy method to fabricate a micro-nano structure hydrophobic surface on magnesium alloy. Furthermore, our research on the creating of micro-nano structure roughness surface and the hydrophobic treatment can be easily extended to the other metal materials.

PSO-Based Algorithm Applied to Quadcopter Micro Air Vehicle Controller Design

Directory of Open Access Journals (Sweden)

Huu-Khoa Tran

2016-09-01

Full Text Available Due to the rapid development of science and technology in recent times, many effective controllers are designed and applied successfully to complicated systems. The significant task of controller design is to determine optimized control gains in a short period of time. With this purpose in mind, a combination of the particle swarm optimization (PSO-based algorithm and the evolutionary programming (EP algorithm is introduced in this article. The benefit of this integration algorithm is the creation of new best-parameters for control design schemes. The proposed controller designs are then demonstrated to have the best performance for nonlinear micro air vehicle models.

Stirling based micro co-generation system for single households

Energy Technology Data Exchange (ETDEWEB)

Ribberink, J.S.; Zutt, J.G.M.; Rabou, L.P.L.M.; Beckers, G.J.J. [ECN Clean Fossil Fuels, Petten (Netherlands); Baijens, C.A.W.; Luttikholt, J.J.M. [ATAG Verwarming, Lichtenvoorde (Netherlands)

2000-04-01

This paper describes the progress made in the ENATEC development program for a free piston Stirling engine based micro co-generation system that serves the supply of up to 1 kW{sub e} and up to 24 kW heat for domestic heating and/or for hot tap water production for single households at overall system efficiencies of 96%. Experiments show that the free piston Stirling engines from Stirling Technology Company run very reliably and controllably, and that the efficiency targets for the 1 kW{sub e} micro co-generation system are feasible. A ceramic foam burner with good heat transfer characteristics and low NOx emissions was developed. A demonstration micro co-generation unit was built and successfully presented. A 1 kW{sub e} free piston Stirling engine for the European market was developed. High efficiencies at full load and at part load, low emissions, low noise, and minimum maintenance make the Stirling engine based micro co-generation system an attractive candidate for the next generation of domestic boilers in Europe. 5 refs.

Soil class around me Serpong experimental power reactor (EPR) site plan base on micro tremor data

International Nuclear Information System (INIS)

Marjiyono; Soehaimi A; Hadi Suntoko; Yuliastuti; Syaeful H

2015-01-01

Surface geological characteristics has an important role on site response analysis in a region. In regard with experimental power reactor (EPR) construction plan in Serpong, the subsurface modeling from combination array and single station micro tremor data was done. The array and single station micro tremor measurement were performed in 9 and 90 sites, respectively, at ± 1 km radius around the EPR site plan. The Vs30 value was calculated from shear wave velocity structure around the investigated area. The soil classification based on Vs30 in the investigated area generally consists of SD (medium soil) and SC (soft rock) class. The EPR site plan its self in the SD class region. (author)

Energy flow modeling and optimal operation analysis of the micro energy grid based on energy hub

International Nuclear Information System (INIS)

Ma, Tengfei; Wu, Junyong; Hao, Liangliang

2017-01-01

Highlights: • Design a novel architecture for energy hub integrating power hub, cooling hub and heating hub. • The micro energy grid based on energy hub is introduced and its advantages are discussed. • Propose a generic modeling method for the energy flow of micro energy grid. • Propose an optimal operation model for micro energy grid with considering demand response. • The roles of renewable energy, energy storage devices and demand response are discussed separately. - Abstract: The energy security and environmental problems impel people to explore a more efficient, environment friendly and economical energy utilization pattern. In this paper, the coordinated operation and optimal dispatch strategies for multiple energy system are studied at the whole Micro Energy Grid level. To augment the operation flexibility of energy hub, the innovation sub-energy hub structure including power hub, heating hub and cooling hub is put forward. Basing on it, a generic energy hub architecture integrating renewable energy, combined cooling heating and power, and energy storage devices is developed. Moreover, a generic modeling method for the energy flow of micro energy grid is proposed. To minimize the daily operation cost, a day-ahead dynamic optimal operation model is formulated as a mixed integer linear programming optimization problem with considering the demand response. Case studies are undertaken on a community Micro Energy Grid in four different scenarios on a typical summer day and the roles of renewable energy, energy storage devices and demand response are discussed separately. Numerical simulation results indicate that the proposed energy flow modeling and optimal operation method are universal and effective over the entire energy dispatching horizon.

Network-based ranking methods for prediction of novel disease associated microRNAs.

Science.gov (United States)

Le, Duc-Hau

2015-10-01

Many studies have shown roles of microRNAs on human disease and a number of computational methods have been proposed to predict such associations by ranking candidate microRNAs according to their relevance to a disease. Among them, machine learning-based methods usually have a limitation in specifying non-disease microRNAs as negative training samples. Meanwhile, network-based methods are becoming dominant since they well exploit a "disease module" principle in microRNA functional similarity networks. Of which, random walk with restart (RWR) algorithm-based method is currently state-of-the-art. The use of this algorithm was inspired from its success in predicting disease gene because the "disease module" principle also exists in protein interaction networks. Besides, many algorithms designed for webpage ranking have been successfully applied in ranking disease candidate genes because web networks share topological properties with protein interaction networks. However, these algorithms have not yet been utilized for disease microRNA prediction. We constructed microRNA functional similarity networks based on shared targets of microRNAs, and then we integrated them with a microRNA functional synergistic network, which was recently identified. After analyzing topological properties of these networks, in addition to RWR, we assessed the performance of (i) PRINCE (PRIoritizatioN and Complex Elucidation), which was proposed for disease gene prediction; (ii) PageRank with Priors (PRP) and K-Step Markov (KSM), which were used for studying web networks; and (iii) a neighborhood-based algorithm. Analyses on topological properties showed that all microRNA functional similarity networks are small-worldness and scale-free. The performance of each algorithm was assessed based on average AUC values on 35 disease phenotypes and average rankings of newly discovered disease microRNAs. As a result, the performance on the integrated network was better than that on individual ones. In

Cantilever-based micro-particle filter with simultaneous single particle detection

DEFF Research Database (Denmark)

Noeth, Nadine-Nicole; Keller, Stephan Sylvest; Boisen, Anja

2011-01-01

Currently, separation of whole blood samples on lab-on-a-chip systems is achieved via filters followed by analysis of the filtered matter such as counting of blood cells. Here, a micro-chip based on cantilever technology is developed, which enables simultaneous filtration and counting of micro-particles...... from a liquid. A hole-array is integrated into a micro-cantilever, which is inserted into a microfluidic channel perpendicular to the flow. A metal pad at the apex of the cantilever enables an optical read-out of the deflection of the cantilever. When a micro-particle is too large to pass a hole...

Highly Tunable Complementary Micro/Submicro-Nanopatterned Surfaces Combining Block Copolymer Self-Assembly and Colloidal Lithography.

Science.gov (United States)

Chang, Tongxin; Du, Binyang; Huang, Haiying; He, Tianbai

2016-08-31

Two kinds of large-area ordered and highly tunable micro/submicro-nanopatterned surfaces in a complementary manner were successfully fabricated by elaborately combining block copolymer self-assembly and colloidal lithography. Employing a monolayer of polystyrene (PS) colloidal spheres assembled on top as etching mask, polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) or polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) micelle films were patterned into micro/submicro patches by plasma etching, which could be further transferred into micropatterned metal nanoarrays by subsequent metal precursor loading and a second plasma etching. On the other hand, micro/submicro-nanopatterns in a complementary manner were generated via preloading a metal precursor in initial micelle films before the assembly of PS colloidal spheres on top. Both kinds of micro/submicro-nanopatterns showed good fidelity at the micro/submicroscale and nanoscale; meanwhile, they could be flexibly tuned by the sample and processing parameters. Significantly, when the PS colloidal sphere size was reduced to 250 nm, a high-resolution submicro-nanostructured surface with 3-5 metal nanoparticles in each patch or a single-nanoparticle interconnected honeycomb network was achieved. Moreover, by applying gold (Au) nanoparticles as anchoring points, micronanopatterned Au arrays can serve as a flexible template to pattern bovine serum albumin (BSA) molecules. This facile and cost-effective approach may provide a novel platform for fabrication of micropatterned nanoarrays with high tunability and controllability, which are promising in the applications of biological and microelectronic fields.

Nitrate removal and microbial analysis by combined micro-electrolysis and autotrophic denitrification.

Science.gov (United States)

Xing, Wei; Li, Desheng; Li, Jinlong; Hu, Qianyi; Deng, Shihai

2016-07-01

A process combining micro-electrolysis and autotrophic denitrification (CEAD) with iron-carbon micro-electrolysis carriers was developed for nitrate removal. The process was performed using organic-free influent with a NO3(-)-N concentration of 40.0±3.0mg/L and provided an average nitrate removal efficiency of 95% in stable stages. The total nitrogen removal efficiency reached 75%, with 21% of NO3(-)-N converted into NH4(+)-N. The corresponding hydraulic retention time was 8-10h, and the optimal pH ranged from 8.5 to 9.5. Microbial analysis with high-throughput sequencing revealed that dominant microorganisms in the reactor belonged to the classes of β-, γ-, and α-Proteobacteria. The abundance of the genera Thermomonas significantly increased during the operation, comprising 21.4% and 24.1% in sludge attached to the carriers in the middle and at the bottom of the reactor, respectively. The developed CEAD achieved efficient nitrate removal from water without organics, which is suitable for practical application. Copyright © 2016. Published by Elsevier Ltd.

Control and experimental characterization of a methanol reformer for a 350 W high temperature polymer electrolyte membrane fuel cell system

DEFF Research Database (Denmark)

Andreasen, Søren Juhl; Kær, Søren Knudsen; Sahlin, Simon Lennart

2013-01-01

is the water and methanol mixture fuel flow and the burner fuel/air ratio and combined flow. An experimental setup is presented capable of testing the methanol reformer used in the Serenergy H3 350 Mobile Battery Charger; a high temperature polymer electrolyte membrane (HTPEM) fuel cell system......This work presents a control strategy for controlling the methanol reformer temperature of a 350 W high temperature polymer electrolyte membrane fuel cell system, by using a cascade control structure for reliable system operation. The primary states affecting the methanol catalyst bed temperature....... The experimental system consists of a fuel evaporator utilizing the high temperature waste gas from the cathode air cooled 45 cell HTPEM fuel cell stack. The fuel cells used are BASF P1000 MEAs which use phosphoric acid doped polybenzimidazole membranes. The resulting reformate gas output of the reformer system...

Recent improvements on micro-thermocouple based SThM

OpenAIRE

Nguyen, T. P.; Thiery, L.; Teyssieux, D.; Briand, Danick; Vairac, P.

2017-01-01

The scanning thermal microscope (SThM) has become a versatile tool for local surface temperature mapping or measuring thermal properties of solid materials. In this article, we present recent improvements in a SThM system, based on a micro-wire thermocouple probe associated with a quartz tuning fork for contact strength detection. Some results obtained on an electrothermal micro-hotplate device, operated in active and passive modes, allow demonstrating its performance as a coupled force detec...

Studying the Combination Effect of Additives and Micro Steel Fibers on Cracks of Self-Healing Concrete

Directory of Open Access Journals (Sweden)

Muhannad Hussien Muhsin

2017-01-01

Full Text Available In this study, the effect of the combination of micro steel fibers and additives (calcium hydroxide and sodium carbonate on the size of cracks formation and healing them were investigated. This study aims to apply the use of self-healing phenomenon to repair cracks and to enhance the service life of the concrete structures. Micro steel fibers straight type were used in this research with 0.2% and 0.4% by volume of concrete. A weight of 20 and 30 kg/m3 of Ca(OH2 and 2 and 3 kg/m3 of Na2CO3 were used as a partial cement replacement. The results confirm that the concrete cracks were significantly self-healed up to 30 days re-curing. Cracks width up to 0.2 mm were completely self-healed after re-curing for 90 days by using the combination of micro steel fiber of 0.4% by volume of concrete and 25 kg/m3 of Ca(OH2 and 2.5 kg/m3 of Na2CO3 as a partial replacement of cement. Products of Self-healing are observed by Scanning Electron Microscopy (SEM with Energy Dispersive X-Ray Analysis (EDX. It was found that self-healing occurred mainly due to precipitation of calcium carbonate.

Laser beam micro-milling of micro-channels in aerospace alloys

CERN Document Server

Ahmed, Naveed; Al-Ahmari, Abdulrahman

2017-01-01

This volume is greatly helpful to micro-machining and laser engineers as it offers obliging guidelines about the micro-channel fabrications through Nd:YAG laser beam micro-milling. The book also demonstrates how the laser beam micro-milling behaves when operating under wet conditions (under water), and explores what are the pros and cons of this hybrid technique. From the predictive mathematical models, the readers can easily estimate the resulting micro-channel size against the desired laser parametric combinations. The book considers micro-channels in three highly important research materials commonly used in aerospace industry: titanium alloy Ti-6Al-4V, nickel alloy Inconel 718 and aluminum alloy AA 2024. Therefore, the book is highly practicable in the fields of micro-channel heat exchangers, micro-channel aerospace turbine blades, micro-channel heat pipes, micro-coolers and micro-channel pulsating heat plates. These are frequently used in various industries such as aerospace, automotive, biomedical and m...

Fabrication of LTCC based Micro Thruster for Precision Controlled Spaceflight

DEFF Research Database (Denmark)

Larsen, Jack; Jørgensen, John Leif

2011-01-01

The paper at hand presents the initial investigations on the development and fabrication of a micro thruster based on LTCC technology, delivering a thrust in the micro Newton regime. Using smaller segments of an observation system distributed on two or more spacecrafts, one can realize an observa...

Recent improvements on micro-thermocouple based SThM

Science.gov (United States)

Nguyen, TP; Thiery, L.; Teyssieux, D.; Briand, D.; Vairac, P.

2017-01-01

The scanning thermal microscope (SThM) has become a versatile tool for local surface temperature mapping or measuring thermal properties of solid materials. In this article, we present recent improvements in a SThM system, based on a micro-wire thermocouple probe associated with a quartz tuning fork for contact strength detection. Some results obtained on an electrothermal micro-hotplate device, operated in active and passive modes, allow demonstrating its performance as a coupled force detection and thermal measurement system.

Combinatorial microRNA target predictions

DEFF Research Database (Denmark)

Krek, Azra; Grün, Dominic; Poy, Matthew N.

2005-01-01

MicroRNAs are small noncoding RNAs that recognize and bind to partially complementary sites in the 3' untranslated regions of target genes in animals and, by unknown mechanisms, regulate protein production of the target transcript1, 2, 3. Different combinations of microRNAs are expressed...... in different cell types and may coordinately regulate cell-specific target genes. Here, we present PicTar, a computational method for identifying common targets of microRNAs. Statistical tests using genome-wide alignments of eight vertebrate genomes, PicTar's ability to specifically recover published micro......RNA targets, and experimental validation of seven predicted targets suggest that PicTar has an excellent success rate in predicting targets for single microRNAs and for combinations of microRNAs. We find that vertebrate microRNAs target, on average, roughly 200 transcripts each. Furthermore, our results...

Gallium nitride-based micro-opto-electro-mechanical systems

Science.gov (United States)

Stonas, Andreas Robert

Gallium Nitride and its associated alloys InGaN and AlGaN have many material properties that are highly desirable for micro-electro-mechanical systems (MEMS), and more specifically micro-opto-electro-mechanical systems (MOEMS). The group III-nitrides are tough, stiff, optically transparent, direct bandgap, chemically inert, highly piezoelectric, and capable of functioning at high temperatures. There is currently no other semiconductor system that possesses all of these properties. Taken together, these attributes make the nitrides prime candidates not only for creating new versions of existing device structures, but also for creating entirely unique devices which combine these properties in novel ways. Unfortunately, their chemical resiliency also makes the group III-nitrides extraordinarily difficult to shape into devices. In particular, until this research, no undercut etch technology existed that could controllably separate a selected part of a MEMS device from its sapphire or silicon carbide substrate. This has effectively prevented GaN-based MEMS from being developed. This dissertation describes how this fabrication obstacle was overcome by a novel etching geometry (bandgap-selective backside-illuminated photoelectochemical (BS-BIPEC) etching) and its resulting morphologies. Several gallium-nitride based MEMS devices were created, actuated, and modelled, including cantilevers and membranes. We describe in particular our pursuit of one of the many novel device elements that is possible only in this material system: a transducer that uses an externally applied strain to dynamically change the optical transition energy of a quantum well. While the device objective of a dynamically tunable quantum well was not achieved, we have demonstrated sufficient progress to believe that such a device will be possible soon. We have observed a shift (5.5meV) of quantum well transition energies in released structures, and we have created structures that can apply large biaxial

MEMS-Based Micro Gas Chromatography: Design, Fabrication and Characterization

OpenAIRE

Zareian-Jahromi, Mohammad Amin

2009-01-01

This work is focused on the design, fabrication and characterization of high performance MEMS-based micro gas chromatography columns having wide range of applications in the pharmaceutical industry, environmental monitoring, petroleum distillation, clinical chemistry, and food processing. The first part of this work describes different approaches to achieve high-performance microfabricated silicon-glass separation columns for micro gas chromatographic (µGC) systems. The capillary width effec...

Synthesis and characterization of hybrid micro/nano-structured NiTi surfaces by a combination of etching and anodizing

Science.gov (United States)

Huan, Z.; Fratila-Apachitei, L. E.; Apachitei, I.; Duszczyk, J.

2014-02-01

The purpose of this study was to generate hybrid micro/nano-structures on biomedical nickel-titanium alloy (NiTi). To achieve this, NiTi surfaces were firstly electrochemically etched and then anodized in fluoride-containing electrolyte. With the etching process, the NiTi surface was micro-roughened through the formation of micropits uniformly distributed over the entire surface. Following the subsequent anodizing process, self-organized nanotube structures enriched in TiO2 could be superimposed on the etched surface under specific conditions. Furthermore, the anodizing treatment significantly reduced water contact angles and increased the surface free energy compared to the surfaces prior to anodizing. The results of this study show for the first time that it is possible to create hybrid micro/nano-structures on biomedical NiTi alloys by combining electrochemical etching and anodizing under controlled conditions. These novel structures are expected to significantly enhance the surface biofunctionality of the material when compared to conventional implant devices with either micro- or nano-structured surfaces.

Synthesis and characterization of hybrid micro/nano-structured NiTi surfaces by a combination of etching and anodizing

International Nuclear Information System (INIS)

Huan, Z; Fratila-Apachitei, L E; Apachitei, I; Duszczyk, J

2014-01-01

The purpose of this study was to generate hybrid micro/nano-structures on biomedical nickel–titanium alloy (NiTi). To achieve this, NiTi surfaces were firstly electrochemically etched and then anodized in fluoride-containing electrolyte. With the etching process, the NiTi surface was micro-roughened through the formation of micropits uniformly distributed over the entire surface. Following the subsequent anodizing process, self-organized nanotube structures enriched in TiO 2 could be superimposed on the etched surface under specific conditions. Furthermore, the anodizing treatment significantly reduced water contact angles and increased the surface free energy compared to the surfaces prior to anodizing. The results of this study show for the first time that it is possible to create hybrid micro/nano-structures on biomedical NiTi alloys by combining electrochemical etching and anodizing under controlled conditions. These novel structures are expected to significantly enhance the surface biofunctionality of the material when compared to conventional implant devices with either micro- or nano-structured surfaces. (paper)

Synthesis and characterization of hybrid micro/nano-structured NiTi surfaces by a combination of etching and anodizing.

Science.gov (United States)

Huan, Z; Fratila-Apachitei, L E; Apachitei, I; Duszczyk, J

2014-02-07

The purpose of this study was to generate hybrid micro/nano-structures on biomedical nickel-titanium alloy (NiTi). To achieve this, NiTi surfaces were firstly electrochemically etched and then anodized in fluoride-containing electrolyte. With the etching process, the NiTi surface was micro-roughened through the formation of micropits uniformly distributed over the entire surface. Following the subsequent anodizing process, self-organized nanotube structures enriched in TiO2 could be superimposed on the etched surface under specific conditions. Furthermore, the anodizing treatment significantly reduced water contact angles and increased the surface free energy compared to the surfaces prior to anodizing. The results of this study show for the first time that it is possible to create hybrid micro/nano-structures on biomedical NiTi alloys by combining electrochemical etching and anodizing under controlled conditions. These novel structures are expected to significantly enhance the surface biofunctionality of the material when compared to conventional implant devices with either micro- or nano-structured surfaces.

Machine Vision based Micro-crack Inspection in Thin-film Solar Cell Panel

Directory of Open Access Journals (Sweden)

Zhang Yinong

2014-09-01

Full Text Available Thin film solar cell consists of various layers so the surface of solar cell shows heterogeneous textures. Because of this property the visual inspection of micro-crack is very difficult. In this paper, we propose the machine vision-based micro-crack detection scheme for thin film solar cell panel. In the proposed method, the crack edge detection is based on the application of diagonal-kernel and cross-kernel in parallel. Experimental results show that the proposed method has better performance of micro-crack detection than conventional anisotropic model based methods on a cross- kernel.

Integration of micro milling highspeed spindle on a microEDM-milling machine set-up

DEFF Research Database (Denmark)

De Grave, Arnaud; Hansen, Hans Nørgaard; Andolfatto, Loic

2009-01-01

In order to cope with repositioning errors and to combine the fast removal rate of micro milling with the precision and small feature size achievable with micro EDM milling, a hybrid micro-milling and micro-EDM milling centre was built and tested. The aim was to build an affordable set-up, easy...... by micro milling. Examples of test parts are shown and used as an experimental validation....

Research on applications of rectangular beam in micro laser propulsion

International Nuclear Information System (INIS)

Jiao, L.; Cai, J.; Ma, H.H.; Li, G.X.; Li, L.; Shen, Z.W.; Tang, Z.P.

2014-01-01

Highlights: • Diode laser bar of 808 nm is introduced into the micro laser propulsion field. • Double base propellant (DBP) coating with BOPP substrate was obtained. • The combination of laser power and energy decides the propulsion performance. • The new rectangular beam prefers to produce higher impulse. - Abstract: Micro laser propulsion is a new technology with brilliant future. In order to reduce the thruster mass and volume further, laser bar is introduced into the micro laser propulsion field. A new kind of 220 × 20 μm rectangular beam of 808 nm was obtained by oval lens compressing the light of diode at fast axes and slow axes. The effect of laser power, energy and coating thickness of double base propellant on propulsion performance was studied. Propulsion performance of double base propellant under static and dynamic mode shows some different characters. Compared to round beam, the new beam prefers to produce higher impulse. Ablation efficiency of DBP shows better performance in short laser duration. The combination of power density and energy density decides the laser propulsion performance. The new rectangular beam is appropriate for millisecond micro-laser propulsion

Poly-dimethylsiloxane (PDMS) based micro-reactors for steam reforming of methanol

Energy Technology Data Exchange (ETDEWEB)

Ha, Ji Won; Kundu, Arunabha; Jang, Jae Hyuk

2010-11-15

A miniaturized methanol steam reformer with a serpentine type of micro-channels was developed based on poly-dimethylsiloxane (PDMS) material. This way of fabricating micro-hydrogen generator is very simple and inexpensive. The volume of a PDMS micro-reformer is less than 10 cm{sup 3}. The catalyst used was a commercial Cu/ZnO/Al{sub 2}O{sub 3} reforming catalyst from Johnson Matthey. The Cu/ZnO/Al{sub 2}O{sub 3} reforming catalyst particles of mean diameter 50-70 {mu}m was packed into the micro-channels by injecting water based suspension of catalyst particles at the inlet point. The miniaturized PDMS micro-reformer was operated successfully in the operating temperatures of 180-240 C and 15%-75% molar methanol conversion was achieved in this temperature range for WHSV of 2.1-4.2 h{sup -1}. It was not possible to operate the micro-reformer made by pure PDMS at temperature beyond 240 C. Hybrid type of micro-reformer was fabricated by mixing PDMS and silica powder which allowed the operating temperature around 300 C. The complete conversion (99.5%) of methanol was achieved at 280 C in this case. The maximum reformate gas flow rate was 30 ml/min which can produce 1 W power at 0.6 V assuming hydrogen utilization of 60%. (author)

A novel micro-accelerometer with adjustable sensitivity based on resonant tunnelling diodes

International Nuclear Information System (INIS)

Ji-Jun, Xiong; Wen-Dong, Zhang; Kai-Qun, Wang; Hai-Yang, Mao

2009-01-01

Resonant tunnelling diodes (RTDs) have negative differential resistance effect, and the current-voltage characteristics change as a function of external stress, which is regarded as meso-piezoresistance effect of RTDs. In this paper, a novel micro-accelerometer based on AlAs/GaAs/In 0.1 Ga 0.9 As/GaAs/AlAs RTDs is designed and fabricated to be a four-beam-mass structure, and an RTD-Wheatstone bridge measurement system is established to test the basic properties of this novel accelerometer. According to the experimental results, the sensitivity of the RTD based micro-accelerometer is adjustable within a range of 3 orders when the bias voltage of the sensor changes. The largest sensitivity of this RTD based micro-accelerometer is 560.2025 mV/g which is about 10 times larger than that of silicon based micro piezoresistive accelerometer, while the smallest one is 1.49135 mV/g. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Salmonella Typhimurium and Staphylococcus aureus dynamics in/on variable (micro)structures of fish-based model systems at suboptimal temperatures.

Science.gov (United States)

Baka, Maria; Verheyen, Davy; Cornette, Nicolas; Vercruyssen, Stijn; Van Impe, Jan F

2017-01-02

The limited knowledge concerning the influence of food (micro)structure on microbial dynamics decreases the accuracy of the developed predictive models, as most studies have mainly been based on experimental data obtained in liquid microbiological media or in/on real foods. The use of model systems has a great potential when studying this complex factor. Apart from the variability in (micro)structural properties, model systems vary in compositional aspects, as a consequence of their (micro)structural variation. In this study, different experimental food model systems, with compositional and physicochemical properties similar to fish patés, are developed to study the influence of food (micro)structure on microbial dynamics. The microbiological safety of fish products is of major importance given the numerous cases of salmonellosis and infections attributed to staphylococcus toxins. The model systems understudy represent food (micro)structures of liquids, aqueous gels, emulsions and gelled emulsions. The growth/inactivation dynamics and a modelling approach of combined growth and inactivation of Salmonella Typhimurium and Staphylococcus aureus, related to fish products, are investigated in/on these model systems at temperatures relevant to fish products' common storage (4°C) and to abuse storage temperatures (8 and 12°C). ComBase (http://www.combase.cc/) predictions compared with the maximum specific growth rate (μ max ) values estimated by the Baranyi and Roberts model in the current study indicated that the (micro)structure influences the microbial dynamics. Overall, ComBase overestimated microbial growth at the same pH, a w and storage temperature. Finally, the storage temperature had also an influence on how much each model system affected the microbial dynamics. Copyright © 2016. Published by Elsevier B.V.

Design, Fabrication and Prototype testing of a Chip Integrated Micro PEM Fuel Cell Accumulator combined On-Board Range Extender

International Nuclear Information System (INIS)

Balakrishnan, A; Mueller, C; Reinecke, H

2014-01-01

In this work we present the design, fabrication and prototype testing of Chip Integrated Micro PEM Fuel Cell Accumulator (CIμ-PFCA) combined On-Board Range Extender (O-BRE). CIμ-PFCA is silicon based micro-PEM fuel cell system with an integrated hydrogen storage feature (palladium metal hydride), the run time of CIμ-PFCA is dependent on the stored hydrogen, and in order to extend its run time an O-BRE is realized (catalytic hydrolysis of chemical hydride, NaBH 4 . Combining the CIμ-PFCA and O-BRE on a system level have few important design requirements to be considered; hydrogen regulation, gas -liquid separator between the CIμ-PFCA and the O-RE. The usage of traditional techniques to regulate hydrogen (tubes), gas-liquid phase membranes (porous membrane separators) are less desirable in the micro domain, due to its space constraint. Our approach is to use a passive hydrogen regulation and gas-liquid phase separation concept; to use palladium membrane. Palladium regulates hydrogen by concentration diffusion, and its property to selectively adsorb only hydrogen is used as a passive gas-liquid phase separator. Proof of concept is shown by realizing a prototype system. The system is an assembly of CIμ-PFCA, palladium membrane and the O-BRE. The CIμ-PFCA consist of 2 individually processed silicon chips, copper supported palladium membrane realized by electroplating followed by high temperature annealing process under inter atmosphere and the O-BRE is realized out of a polymer substrate by micromilling process with platinum coated structures, which functions as a catalyst for the hydrolysis of NaBH 4 . The functionality of the assembled prototype system is demonstrated by the measuring a unit cell (area 1 mm 2 ) when driven by the catalytic hydrolysis of chemical hydride (NaBH 4 and the prototype system shows run time more than 15 hours

MEMS-based micro-fuel processor for application in a cell phone

Energy Technology Data Exchange (ETDEWEB)

Kundu, Arunabha; Jang, Jae Hyuk; Lee, Hong Ryul; Kim, Sung-Han; Gil, Jae Hyoung; Jung, Chang Ryul; Oh, Yong Soo [Micro-Fuel Cell Team, Electro-Material and Device (eMD) Laboratory, Corporate R and D Center, Samsung Electro-Mechanics, 314 Maetan-Dong, Yeongtong-Gu, Suwon, Gyunngi-Do 443-743 (Korea, Republic of)

2006-11-08

The operation of a micro-electro-mechanical system (MEMS)-based micro-reformer was investigated for application in a cell phone. Different aspects like the time required to attain the desired temperature of the system, the time required to get the required hydrogen flow, catalyst durability, flow uniformity of the mixture of methanol and water and volume of the total system were considered. A loading procedure for the catalyst in the micro-reformer was developed. Catalyst deactivation was observed after operating continuously for 8h, but it regained its original activity after the reformer was shut down for at least 2h. The deactivation of the catalyst was analyzed by catalyst characterization. The comparison of the performance between a parallel channeled and serpentine channeled micro-reformer was carried out. The performance with the serpentine channeled micro-reformer was always higher than with parallel channeled micro-reformer. The shorter residence time in the parallel-channeled micro-reformer may be one of the reasons behind its low activity. (author)

Stirling engine based micro co-generation system for single households

Energy Technology Data Exchange (ETDEWEB)

Ribberink, H.; Zutt, S.; Rabou, L.; Beckers, G. [Netherlands Energy Research Foundation (ECN), Petten (Netherlands); Baijens, K.; Luttikholt, J. [Atag Verwarming BV (Netherlands)

2000-07-01

This paper describes the progress made in the ENATEC development program for a free piston Stirling engine based micro co-generation system that serves the supply of up to 1 kW{sub e} and up to 24 kW heat for domestic heating and/or for hot tap water production for single households at overall system efficiencies of 96%: Experiments show that the free piston Stirling engines from Stirling Technology Company run very reliably and controllably, and that the efficiency targets for the 1 kW{sub e} micro co-generation system are feasible. A ceramic foam burner with good heat transfer characteristics and low NOx emissions was developed. A demonstration micro co-generation unit was built and successfully presented. A 1 kW{sub e} free piston Stirling engine for the European market was developed. High efficiencies at full load and at part load, low emissions, low noise, and minimum maintenance make the Stirling engine based micro co-generation system an attractive candidate for the next generation of domestic boilers in Europe. (orig.)

Getting Started with PEAs-Based Flapping-Wing Mechanisms for Micro Aerial Systems

Directory of Open Access Journals (Sweden)

José Carlos Durán Hernández

2016-05-01

Full Text Available This paper introduces recent advances on flapping-wing Micro and Nano Aerial Vehicles (MAVs and NAVs based on Piezoelectric Actuators (PEA. Therefore, this work provides essential information to address the development of such bio-inspired aerial robots. PEA are commonly used in micro-robotics and precise positioning applications (e.g., micro-positioning and micro-manipulation, whereas within the Unmanned Aerial Vehicles (UAVs domain, motors are the classical actuators used for rotary or fixed-wing configurations. Therefore, we consider it pertinent to provide essential information regarding the modeling and control of piezoelectric cantilever actuators to accelerate early design and development stages of aerial microrobots based on flapping-wing systems. In addition, the equations describing the aerodynamic behavior of a flapping-wing configuration are presented.

Microstructure-Based Computational Modeling of Mechanical Behavior of Polymer Micro/Nano Composites

Science.gov (United States)

2013-12-01

automotive, defense, sport, civil, aerospace, health , etc.). Here, a combination of non-linear thermo-viscoelastic (Schapery’s non-linear...2001. Three-dimensional computational micro-mechanical model for woven fabric composites. Composite Structures 54, 489-496. Jacob, G.C., Starbuck

Modeling and Reconstruction of Micro-structured 3D Chitosan/Gelatin Porous Scaffolds Using Micro-CT

Science.gov (United States)

Gong, Haibo; Li, Dichen; He, Jiankang; Liu, Yaxiong; Lian, Qin; Zhao, Jinna

2008-09-01

Three dimensional (3D) channel networks are the key to promise the uniform distribution of nutrients inside 3D hepatic tissue engineering scaffolds and prompt elimination of metabolic products out of the scaffolds. 3D chitosan/gelatin porous scaffolds with predefined internal channels were fabricated and a combination of light microscope, laser confocal microscopy and micro-CT were employed to characterize the structure of porous scaffolds. In order to evaluate the flow field distribution inside the micro-structured 3D scaffolds, a computer reconstructing method based on Micro-CT was proposed. According to this evaluating method, a contrast between 3D porous scaffolds with and without predefined internal channels was also performed to assess scaffolds' fluid characters. Results showed that the internal channel of the 3D scaffolds formed the 3D fluid channel network; the uniformity of flow field distribution of the scaffolds fabricated in this paper was better than the simple porous scaffold without micro-fluid channels.

Le séchage combiné convection-micro-ondes : modelisation-validation-optimisation

OpenAIRE

Constant , Thiéry

1992-01-01

Not available; Ce travail est consacré à l'étude du séchage combiné convection-micro-ondes, le matériau choisi pour l'étude étant un béton cellulaire. Il comporte une partie théorique et une partie expérimentale. D’un point de vue théorique, deux points sont plus particulièrement discutés: la formulation du terme source volumique d'énergie et la modélisation des transferts de chaleur et de masse avec prise en compte du gradient de pression totale de la phase gazeuse. D’un point de vue expérim...

Strategic HRM in Building Micro-Foundations of Organizational Knowledge-Based Performance

DEFF Research Database (Denmark)

Minbaeva, Dana

2013-01-01

Strategic HRM research has a strong potential to further our understanding of how organizational knowledge processes influence performance at various analytical levels. Drawing on ability–motivation–opportunity research and linking it to knowledge sharing behaviors, we discuss the micro......-foundations in the link between strategic HRM practices and knowledge-based organizational performance. We thus describe a research agenda for future micro-foundational research that links strategic HRM and knowledge-based performance....

Fiscal 1999 leading research report. Research on advanced functional material technology based on micro- capsule technology; 1999 nendo micro capsule ka gijutsu ni yoru kokinoka zairyo gijutsu no chosa kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

Study was made on production technology of the 5th- generation material 'eco-smart composite structure' based on micro-capsule technology. This material ought to have an intelligent function including self-detection and self- restoration of defects, environmental harmony, high strength and long life. At present, these demands are implemented by embedding a sensor, actuator and controller in structure, or optical fiber, shape memory alloy and computer chip in matrix, however, such complex material structure has adverse effect on environment. On the other hand, single structure material such as biodegradable polymer is unusable in severe environment such as the ocean and space. These problems can be resolved by combining composite material and micro-sphere technology, for example fiber-reinforced plastic (FRP) composite structure including micro-capsules with nano particles. According to targets, this material can have a self-restoration intelligent function, and other environment friendly functions such as easy decomposition, sound insulation, oscillation damping, electromagnetic shielding and hygroscopicity. (NEDO)

Fiscal 1999 leading research report. Research on advanced functional material technology based on micro- capsule technology; 1999 nendo micro capsule ka gijutsu ni yoru kokinoka zairyo gijutsu no chosa kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

Study was made on production technology of the 5th- generation material 'eco-smart composite structure' based on micro-capsule technology. This material ought to have an intelligent function including self-detection and self- restoration of defects, environmental harmony, high strength and long life. At present, these demands are implemented by embedding a sensor, actuator and controller in structure, or optical fiber, shape memory alloy and computer chip in matrix, however, such complex material structure has adverse effect on environment. On the other hand, single structure material such as biodegradable polymer is unusable in severe environment such as the ocean and space. These problems can be resolved by combining composite material and micro-sphere technology, for example fiber-reinforced plastic (FRP) composite structure including micro-capsules with nano particles. According to targets, this material can have a self-restoration intelligent function, and other environment friendly functions such as easy decomposition, sound insulation, oscillation damping, electromagnetic shielding and hygroscopicity. (NEDO)

Isolation of microRNA targets using biotinylated synthetic microRNAs

DEFF Research Database (Denmark)

Ørom, Ulf Andersson; Lund, Anders H

2007-01-01

MicroRNAs are small regulatory RNAs found in multicellular organisms where they post-transcriptionally regulate gene expression. In animals, microRNAs bind mRNAs via incomplete base pairings making the identification of microRNA targets inherently difficult. Here, we present a detailed method...... for experimental identification of microRNA targets based on affinity purification of tagged microRNAs associated with their targets. Udgivelsesdato: 2007-Oct...

GaAs-based micro/nanomechanical resonators

Science.gov (United States)

Yamaguchi, Hiroshi

2017-10-01

Micro/nanomechanical resonators have been extensively studied both for device applications, such as high-performance sensors and high-frequency devices, and for fundamental science, such as quantum physics in macroscopic objects. The advantages of GaAs-based semiconductor heterostructures include improved mechanical properties through strain engineering, highly controllable piezoelectric transduction, carrier-mediated optomechanical coupling, and hybridization with quantum low-dimensional structures. This article reviews our recent activities, as well as those of other groups, on the physics and applications of mechanical resonators fabricated using GaAs-based heterostructures.

Modeling and optimization of a heat-pump-assisted high temperature proton exchange membrane fuel cell micro-combined-heat-and-power system for residential applications

DEFF Research Database (Denmark)

Arsalis, Alexandros; Kær, Søren Knudsen; Nielsen, Mads Pagh

2015-01-01

In this study a micro-combined-heat-and-power (micro-CHP) system is coupled to a vapor-compression heat pump to fulfill the residential needs for heating (space heating and water heating) and electricity in detached single-family households in Denmark. Such a combination is assumed to be attractive...... for application, since both fuel cell technology and electric heat pumps are found to be two of the most efficient technologies for generation/conversion of useful energy. The micro-CHP system is fueled with natural gas and includes a fuel cell stack, a fuel processor and other auxiliary components. The micro......-CHP system assumes heat-led operation, to avoid dumping of heat and the use of complicated thermal energy storage. The overall system is grid-interconnected to allow importing and exporting of electricity as necessary. In this study emphasis is given on the operational characterization of the system...

Micro-manufacturing: design and manufacturing of micro-products

National Research Council Canada - National Science Library

Koç, Muammer; Özel, Tuğrul

2011-01-01

.... After addressing the fundamentals and non-metallic-based micro-manufacturing processes in the semiconductor industry, it goes on to address specific metallic-based micro-manufacturing processes...

Crosslinked wholly aromatic polyether membranes based on quinoline derivatives and their application in high temperature polymer electrolyte membrane fuel cells

Science.gov (United States)

Kallitsis, K. J.; Nannou, R.; Andreopoulou, A. K.; Daletou, M. K.; Papaioannou, D.; Neophytides, S. G.; Kallitsis, J. K.

2018-03-01

An AB type difunctional quinoline based monomer bearing a pentafluorophenyl unit combined with a phenol functionality is being synthesized and homopolymerized to create linear aromatic polyethers as polymer electrolytes for HT-PEM FCs applications. Several conditions are tested for the optimized synthesis of the monomer and homopolymer. Additionally, covalent crosslinking through aromatic polyether bond formation enables the creation of wholly aromatic crosslinked polymeric electrolyte membranes. More specifically, the perfluorophenyl units are crosslinked with other hydroxyl end functionalized moieties, providing membranes with enhanced chemical and mechanical properties that are moreover easily doped with phosphoric acid even at ambient temperatures. All membranes are evaluated for their structural and thermal characteristics and their doping ability with phosphoric acid. Selected crosslinked membranes are further tested in terms of their single cell performance at the temperature range 160 °C-200 °C showing promising performance and high conductivity values even up to 0.2 S cm-1 in some cases.

Energy Management of Combined Cooling, Heating and Power Micro Energy Grid Based on Leader-Follower Game Theory

Directory of Open Access Journals (Sweden)

Kaijun Lin

2018-03-01

Full Text Available In this paper, we consider a general model and solution algorithm for the energy management of combined cooling, heating, and power micro energy grid (MEG under the game theory framework. An innovative dynamic leader-follower game strategy is proposed in this paper to balance the interactions between MEG and user. We show that such game between MEG and user has a unique Nash equilibrium (NE, and in order to quantify the user’s expenditure and dissatisfaction, we model them and adopt the fuzzy bi-objective algorithm. For more details in the proposed game model, the MEG leads the game by deciding energy sales prices and optimizing the power, cooling and heating outputs according to the user’s load plan to maximize its own profit. With the prices being released by MEG, user’s adjustment of energy consumption follows and is again fed to MEG. In practice, we initialize simulations with daily loads of a typical community. As the numerical results demonstrate, MEG is proficient in consumption capacity of renewable energy and energy optimization. It also shows that the user achieves his economic optimum with experience of energy usage taken into account.

Simulation and application of micro X-ray fluorescence based on an ellipsoidal capillary

Energy Technology Data Exchange (ETDEWEB)

Yang, Jing; Li, Yude; Wang, Xingyi; Zhang, Xiaoyun; Lin, Xiaoyan, E-mail: yangjing_928@126.com

2017-06-15

Highlights: • A micro X-ray fluorescence setup based on an ellipsoidal capillary was presented. • The optimal parameters of ellipsoidal capillary were designed. • The 2D mapping image of biological sample was obtained. - Abstract: A micro X-ray fluorescence setup was presented, based on an ellipsoidal capillary and a traditional laboratorial X-ray source. Using Ray-tracing principle, we have simulated the transmission path of X-ray beam in the ellipsoidal capillary and designed the optimal parameters of the ellipsoidal capillary for the micro X-ray fluorescence setup. We demonstrate that ellipsoidal capillary is well suited as condenser for the micro X-ray fluorescence based on traditional laboratorial X-ray source. Furthermore, we obtain the 2D mapping image of the leaf blade sample by using the ellipsoidal capillary we designed.

Recent applications and current trends in Cultural Heritage Science using synchrotron-based Fourier transform infrared micro-spectroscopy

Science.gov (United States)

Cotte, Marine; Dumas, Paul; Taniguchi, Yoko; Checroun, Emilie; Walter, Philippe; Susini, Jean

2009-09-01

Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-FTIR) is one of the emerging techniques increasingly employed for Cultural Heritage analytical science. Such a technique combines the assets of FTIR spectroscopy (namely, the identification of molecular groups in various environments: organic/inorganic, crystallized/amorphous, solid/liquid/gas), with the extra potential of chemical imaging (localization of components + easier data treatment thanks to geographical correlations) and the properties of the synchrotron source (namely, high brightness, offering high data quality even with reduced dwell time and reduced spot size). This technique can be applied to nearly all kind of materials found in museum objects, going from hard materials, like metals, to soft materials, like paper, and passing through hybrid materials such as paintings and bones. The purpose is usually the identification of complex compositions in tiny, heterogeneous samples. Recent applications are reviewed in this article, together with the fundamental aspects of the infrared synchrotron source which are leading to such improvements in analytical capabilities. A recent example from the ancient Buddhist paintings from Bamiyan is detailed. Emphasis is made on the true potential offered at such large scale facilities in combining SR-FTIR microscopy with other synchrotron-based micro-imaging techniques. To cite this article: M. Cotte et al., C. R. Physique 10 (2009).

Study of thermo-fluidic behavior of micro-droplet in inkjet-based micro manufacturing processes

Science.gov (United States)

Das, Raju; Mahapatra, Abhijit; Ball, Amit Kumar; Roy, Shibendu Shekhar; Murmu, Naresh Chandra

2017-06-01

Inkjet printing technology, a maskless, non-contact patterning operation, which has been a revelation in the field of micro and nano manufacturing for its use in the selective deposition of desired materials. It is becoming an exciting alternative technology such as lithography to print functional material on to a substrate. Selective deposition of functional materials on desired substrates is a basic requirement in many of the printing based micro and nano manufacturing operations like the fabrication of microelectronic devices, solar cell, Light-emitting Diode (LED) research fields like pharmaceutical industries for drug discovery purposes and in biotechnology to make DNA microarrays. In this paper, an attempt has been made to design and develop an indigenous Electrohydrodynamic Inkjet printing system for micro fabrication and to study the interrelationships between various thermos-fluidic parameters of the ink material in the printing process. The effect of printing process parameters on printing performance characteristics has also been studied. And the applicability of the process has also been experimentally demonstrated. The experimentally found results were quite satisfactory and accordance to its applicability.

Ex vivo and in vitro synchrotron-based micro-imaging of biocompatible materials applied in dental surgery

Science.gov (United States)

Rack, A.; Stiller, M.; Nelson, K.; Knabe, C.; Rack, T.; Zabler, S.; Dalügge, O.; Riesemeier, H.; Cecilia, A.; Goebbels, J.

2010-09-01

Biocompatible materials such as porous bioactive calcium phosphate ceramics or titanium are regularly applied in dental surgery: ceramics are used to support the local bone regeneration in a given defect, afterwards titanium implants replace lost teeth. The current gold standard for bone reconstruction in implant dentistry is the use of autogenous bone grafts. But the concept of guided bone regeneration (GBR) has become a predictable and well documented surgical approach using biomaterials (bioactive calcium phosphate ceramics) which qualify as bone substitutes for this kind of application as well. We applied high resolution synchrotron microtomography and subsequent 3d image analysis in order to investigate bone formation and degradation of the bone substitute material in a three-dimensional manner, extending the knowledge beyond the limits of classical histology. Following the bone regeneration, titanium-based implants to replace lost teeth call for high mechanical precision, especially when two-piece concepts are used in order to guaranty leak tightness. Here, synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in these kind of highly attenuating objects. Therefore, we could study micro-gap formation at interfaces in two-piece dental implants with the specimen under different mechanical load. We could prove the existence of micro-gaps for implants with conical connections as well as to study the micromechanical behavior of the mating zone of conical implants during loading. The micro-gap is a potential issue of failure, i. e. bacterial leakage which can induce an inflammatory process.

Development of Next Generation micro-CHP System

DEFF Research Database (Denmark)

Arsalis, Alexandros

Novel proposals for the modeling and operation of a micro-CHP (combined-heat-andpower) residential system based on HT-PEMFC (High Temperature-Proton Exchange Membrane Fuel Cell) technology are described and analyzed to investigate the technical feasibility of such systems. The proposed systems must...

MULTISHAPE TASK SCHEDULING ALGORITHM FOR REAL TIME MICRO-CONTROLLER BASED APPLICATION

OpenAIRE

Ankur Jain

2017-01-01

Embedded Systems are usually microcontroller-based systems that represent a class of reliable and dependable dedicated computer systems designed for specific purposes. Micro-controllers are used in most electronic devices in an endless variety of ways. Some micro-controller-based embedded systems are required to respond to external events in the shortest possible time and such systems are known as realtime embedded systems. So in multitasking system there is a need of task Scheduling, there a...

Improved design and characterization of PLGA/PLA-coated Chitosan based micro-implants for controlled release of hydrophilic drugs.

Science.gov (United States)

Manna, Soumyarwit; Donnell, Anna M; Kaval, Necati; Al-Rjoub, Marwan F; Augsburger, James J; Banerjee, Rupak K

2018-05-29

Repetitive intravitreal injections of Methotrexate (MTX), a hydrophilic chemotherapeutic drug, are currently used to treat selected vitreoretinal (VR) diseases, such as intraocular lymphoma. To avoid complications associated with the rapid release of MTX from the injections, a Polylactic acid (PLA) and Chitosan (CS)-based MTX micro-implant prototype was fabricated in an earlier study, which showed a sustained therapeutic release rate of 0.2-2.0 µg/day of MTX for a period ∼1 month in vitro and in vivo. In the current study, different combinations of Poly(lactic-co-glycolic) acid (PLGA)/PLA coatings were used for lipophilic surface modification of the CS-MTX micro-implant, such as PLGA 5050, PLGA 6535 and PLGA 7525 (PLA: PGA - 50:50, 65:35, 75:25, respectively; M.W: 54,400 - 103,000) and different PLA, such as PLA 100 and PLA 250 (MW: 102,000 and 257,000, respectively). This improved the duration of total MTX release from the coated CS-MTX micro-implants to ∼3-5 months. With an increase in PLA content in PLGA and molecular weight of PLA, a) the initial burst of MTX and the mean release rate of MTX can be reduced; and b) the swelling and biodegradation of the micro-implants can be delayed. The controlled drug release mechanism is caused by a combination of diffusion process and hydrolysis of the polymer coating, which can be modulated by a) PLA content in PLGA and b) molecular weight of PLA, as inferred from Korsmeyer Peppas model, Zero order, First order and Higuchi model fits. This improved micro-implant formulation has the potential to serve as a platform for controlled release of hydrophilic drugs to treat selected VR diseases. Copyright © 2018. Published by Elsevier B.V.

Investigation on the micro injection molding process of an overmolded multi-material micro component

DEFF Research Database (Denmark)

Baruffi, Federico; Calaon, Matteo; Tosello, Guido

and difficult assembly steps, being the plastic molded directly on a metal substrate. In this scenario, an investigation on the fully automated micro overmolding manufacturing technology of a three-material micro component for acoustic applications has been carried out. Preliminary experiments allowed......Micro injection molding (μIM) is one of the few technologies capable of meeting the increasing demand of complex shaped micro plastic parts. This process, combined with the overmolding technique, allows a fast and cost-efficient production of multi-material micro components, saving numerous...

Applying a foil queue micro-electrode in micro-EDM to fabricate a 3D micro-structure

Science.gov (United States)

Xu, Bin; Guo, Kang; Wu, Xiao-yu; Lei, Jian-guo; Liang, Xiong; Guo, Deng-ji; Ma, Jiang; Cheng, Rong

2018-05-01

Applying a 3D micro-electrode in a micro electrical discharge machining (micro-EDM) can fabricate a 3D micro-structure with an up and down reciprocating method. However, this processing method has some shortcomings, such as a low success rate and a complex process for fabrication of 3D micro-electrodes. By focusing on these shortcomings, this paper proposed a novel 3D micro-EDM process based on the foil queue micro-electrode. Firstly, a 3D micro-electrode was discretized into several foil micro-electrodes and these foil micro-electrodes constituted a foil queue micro-electrode. Then, based on the planned process path, foil micro-electrodes were applied in micro-EDM sequentially and the micro-EDM results of each foil micro-electrode were able to superimpose the 3D micro-structure. However, the step effect will occur on the 3D micro-structure surface, which has an adverse effect on the 3D micro-structure. To tackle this problem, this paper proposes to reduce this adverse effect by rounded corner wear at the end of the foil micro-electrode and studies the impact of machining parameters on rounded corner wear and the step effect on the micro-structure surface. Finally, using a wire cutting voltage of 80 V, a current of 0.5 A and a pulse width modulation ratio of 1:4, the foil queue micro-electrode was fabricated by wire electrical discharge machining. Also, using a pulse width of 100 ns, a pulse interval of 200 ns, a voltage of 100 V and workpiece material of 304# stainless steel, the foil queue micro-electrode was applied in micro-EDM for processing of a 3D micro-structure with hemispherical features, which verified the feasibility of this process.

Surface Embedded Metal Oxide Sensors (SEMOS)

DEFF Research Database (Denmark)

Jespersen, Jesper Lebæk; Talat Ali, Syed; Pleth Nielsen, Lars

SEMOS is a joint project between Aalborg University, Danish Technological Institute and Danish Technical University in which micro temperature sensors and metal oxide-based gas sensors are developed and tested in a simulated fuel cell environment as well as in actual working fuel cells. Initially......, sensors for measuring the temperatures in an operating HT-PEM (High Temperature-Proton Exchange Membrane) fuel cell are developed for detecting in-plane temperature variations. 5 different tracks for embedded thermal sensors are investigated. The fuel cell MEA (Membrane Electrode Assembly) is quite...... complex and sensors are not easily implemented in the construction. Hence sensor interface and sensor position must therefore be chosen carefully in order to make the sensors as non-intrusive as possible. Metal Oxide Sensors (MOX) for measuring H2, O2 and CO concentration in a fuel cell environment...

Accurate microRNA target prediction correlates with protein repression levels

Directory of Open Access Journals (Sweden)

Simossis Victor A

2009-09-01

Full Text Available Abstract Background MicroRNAs are small endogenously expressed non-coding RNA molecules that regulate target gene expression through translation repression or messenger RNA degradation. MicroRNA regulation is performed through pairing of the microRNA to sites in the messenger RNA of protein coding genes. Since experimental identification of miRNA target genes poses difficulties, computational microRNA target prediction is one of the key means in deciphering the role of microRNAs in development and disease. Results DIANA-microT 3.0 is an algorithm for microRNA target prediction which is based on several parameters calculated individually for each microRNA and combines conserved and non-conserved microRNA recognition elements into a final prediction score, which correlates with protein production fold change. Specifically, for each predicted interaction the program reports a signal to noise ratio and a precision score which can be used as an indication of the false positive rate of the prediction. Conclusion Recently, several computational target prediction programs were benchmarked based on a set of microRNA target genes identified by the pSILAC method. In this assessment DIANA-microT 3.0 was found to achieve the highest precision among the most widely used microRNA target prediction programs reaching approximately 66%. The DIANA-microT 3.0 prediction results are available online in a user friendly web server at http://www.microrna.gr/microT

Thermodynamic assessment of integrated biogas-based micro-power generation system

International Nuclear Information System (INIS)

Hosseini, Seyed Ehsan; Barzegaravval, Hasan; Wahid, Mazlan Abdul; Ganjehkaviri, Abdolsaeid; Sies, Mohsin Mohd

2016-01-01

Highlights: • A thermodynamic modelling of an integrated biogas-based micro-power generation system is reported. • The impact of design parameters on the thermodynamic performance of the system is evaluated. • High turbine inlet temperatures lead the system to the higher energy and exergy efficiency and higher power generation. • Enhancement of GT isentropic efficiency incurs negative effects on the performance of air preheater and heat exchanger. • The rate of power generation increases by the enhancement of steam turbine pressure in ORC. - Abstract: In this paper, a thermodynamic modelling of an integrated biogas (60%CH_4 + 40%CO_2) micro-power generation system for electricity generation is reported. This system involves a gas turbine cycle and organic Rankine cycle (ORC) where the wasted heat of gas turbine cycle is recovered by closed ORC. The net output power of the micro-power generation system is fixed at 1.4 MW includes 1 MW power generated by GT and 0.4 MW by ORC. Energy and exergy assessments and related parametric studies are carried out, and parameters that influence on energy and exergy efficiency are evaluated. The performance of the system with respect to variation of design parameters such as combustion air inlet temperature, turbine inlet temperature, compressor pressure ratio, gas turbine isentropic efficiency and compressor isentropic efficiency (from the top cycle) and steam turbine inlet pressure, and condenser pressure (from bottoming cycle) is evaluated. The results reveal that by the increase of gas turbine isentropic efficiency, the outlet temperature of gas turbine decreases which incurs negative impacts on the performance of air preheater and heat exchanger, however the energy and exergy efficiency increases in the whole system. By the increase of air compressor pressure ratio, the energy and exergy of the combined cycle decreases. The exergy efficiency of ORC alters by the variation of gas turbine parameters which can be

Micro CHP: implications for energy companies

Energy Technology Data Exchange (ETDEWEB)

Harrison, Jeremy [EA Technology (United Kingdom); Kolin, Simon; Hestevik, Svein [Sigma Elektroteknisk A/S (Norway)

2000-08-01

This article explains how micro combined heat and power (CHP) technology may help UK energy businesses to maintain their customer base in the current climate of liberalisation and competition in the energy market The need for energy companies to adopt new technologies and adapt to changes in the current aggressive environment, the impact of privatisation, and the switching of energy suppliers by customers are discussed. Three potential routes to success for energy companies are identified, namely, price reductions, branding and affinity marketing, and added value services. Details are given of the implementation of schemes to encourage energy efficiency, the impact of the emissions targets set at Kyoto, the advantages of micro CHP generation, business opportunities for CHP, business threats from existing energy companies and others entering the field, and the commercial viability of micro CHP.

CFD Analysis for Optimum Thermal Design of Carbon Nanotube Based Micro-Channel Heatsink

Directory of Open Access Journals (Sweden)

M. Mahbub

2011-10-01

Full Text Available Carbon nanotube (CNT is considered as an ideal material for thermal management in electronic packaging because of its extraordinary high thermal conductivity. Fabricated onto a silicon substrate to form micro-channels, the CNT based cooling fins show high heat dissipation efficiency. A series of 2D and 3D CFD simulations have been carried out for CNT based micro-channel cooling architectures based on one and two dimensional fin array in this paper using COMSOL 4.0a software. Micro-channels are generally regarded as an effective method for the heat transfer in electronic products. The influence of various fluids, micro-fin structures, fluid velocity and heating powers on cooling effects have been simulated and compared in this study. Steady-state thermal stress analyses for the forced convection heat transfer are also performed to determine maximum allowable stress and deflections for the different types of cooling assembly.

[Micro-invasive embedding combined with montelukast sodium for children cough variant asthma:a randomized controlled trial].

Science.gov (United States)

Wang, Xiaoyan; Liu, Baoqin; Lu, Bin; Zhang, Yanmei; Wang, Liran; Li, Haijin; Han, Xue; Ding, Dan

2017-03-12

To observe the effects of micro-invasive embedding combined with montelukast sodium and simple montelukast sodium for children cough variant asthma (CVA). A total of 240 patients were randomly assigned into an observation group and a control group, 120 cases in each one. Considering of cases dropping, 101 patients in the observation group and 105 cases in the control group were included. Montelukast sodium chewable tablets were applied before sleep for 3 months in the control group, 5 mg a time, once a day. Based on the treatment as the control group, micro-invasive embedding was used for 3 months in the observation group, twice in the first month and once in the other two months. The acupoints were Feishu (BL 13), Danzhong (CV 17), Dingchuan (EX-B 1), and Zusanli (ST 36). Follow-up was conducted 9 months after treatment in the two groups. The cough score, serum immunoglobulin (IgE, IgG, IgA), platelet activating factor (PAF) were observed before and after treatment. The indices were compared before and after treatment and at follow-up, including pulmonary function indices[peak expiratory flow rate (PEF), forced expiratory volume at the 1st second (FEV1)], and small airway function indices[forced expiratory flow rate with remaining 25% vital capacity (MEF25%), forced expiratory flow rate with remaining 50% vital capacity (MEF50%), forced expiratory flow rate with remaining 75% vital capacity (MEF75%) and mid expiratory flow rate (MEF25%-75%)]. Also, the total effects were evaluated. ①The total effective rate in the observation group was 93.1% (94/101), which was better than 87.6% (92/105) in the control group ( P disappearance time of the cured children in the observation group was (10.38±2.64) d, and it was shorter than (10.72 ±2.60) d of those in the control group ( P 0.05). ④ There was no statistically significance before and after treatment on small airway function indices in the two groups (all P >0.05). The indices at follow-up increased compared with

Modeling of combined effects of citral, linalool and beta-pinene used against Saccharomyces cerevisiae in citrus-based beverages subjected to a mild heat treatment.

Science.gov (United States)

Belletti, Nicoletta; Kamdem, Sylvain Sado; Tabanelli, Giulia; Lanciotti, Rosalba; Gardini, Fausto

2010-01-01

The aim of this work was to evaluate the antimicrobial activity of three terpenes (citral, linalool and beta-pinene), in combination with a mild heat treatment (55 degrees C, 15 min). The study has been carried out on an orange based soft drink inoculated using a wild strain of Saccharomyces cerevisiae. The results, expressed as growth/no-growth data, were analyzed with the logistic regression. A model comprising only of significant individual parameters (p < or = 0.05) and describing the relationships between terpene concentrations and the probability of having stable beverages was obtained. When citral and beta-pinene were combined, the citral concentration required to achieve a 50% probability of having stable bottles (P=0.5) dropped from 100.9 microL/L in the absence of beta-pinene to 49.3 microL/L in the presence of 20 microL/L of beta-pinene. The mixture of citral and linalool was less effective, in fact, the same probability (P=0.5) was obtained combining 60 microL/L of linalool with 35.1 microL/L of citral. The addition of 20 microL/L of linalool and beta-pinene reinforced citral bioactivity and the concentration of citral needed to reach P=0.5 fell from 100.9 microL/L in the presence of citral alone to 42.0 microL/L. The presence of both linalool and beta-pinene at a concentration of 40 or 60 microL/L in the absence of citral led to a lower spoilage probability (P=0.58 and P=0.93, respectively). It can be concluded that the antimicrobial potential of the three terpenes alone can be strengthened combining appropriate concentrations of each of them. This study confirmed also the potentiating effect of a mild temperature treatment on the antimicrobial efficacy of the molecules. Neither the thermal treatment alone nor the presence of the terpenes at their maximum concentrations (without thermal treatment) were able to guarantee the microbial stability of the beverages. 2009 Elsevier B.V. All rights reserved.

Combined optic system based on polycapillary X-ray optics and single-bounce monocapillary optics for focusing X-rays from a conventional laboratory X-ray source

Energy Technology Data Exchange (ETDEWEB)

Sun, Xuepeng; Liu, Zhiguo [The Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Sun, Tianxi, E-mail: stx@bnu.edu.cn [The Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Yi, Longtao; Sun, Weiyuan; Li, Fangzuo; Jiang, Bowen [The Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Ma, Yongzhong [Center for Disease Control and Prevention of Beijing, Beijing 100013 (China); Ding, Xunliang [The Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China)

2015-12-01

Two combined optic systems based on polycapillary X-ray optics and single-bounce monocapillary optics (SBMO) were designed for focusing the X-rays from a conventional laboratory X-ray source. One was based on a polycapillary focusing X-ray lens (PFXRL) and a single-bounce ellipsoidal capillary (SBEC), in which the output focal spot with the size of tens of micrometers of the PFXRL was used as the “virtual” X-ray source for the SBEC. The other system was based on a polycapillary parallel X-ray lens (PPXRL) and a single-bounce parabolic capillary (SBPC), in which the PPXRL transformed the divergent X-ray beam from an X-ray source into a quasi-parallel X-ray beam with the divergence of sever milliradians as the incident illumination of the SBPC. The experiment results showed that the combined optic systems based on PFXRL and SBEC with a Mo rotating anode X-ray generator with the focal spot with a diameter of 300 μm could obtain a focal spot with the total gain of 14,300 and focal spot size of 37.4 μm, and the combined optic systems based on PPXRL and SBPC with the same X-ray source mentioned above could acquire a focal spot with the total gain of 580 and focal spot size of 58.3 μm, respectively. The two combined optic systems have potential applications in micro X-ray diffraction, micro X-ray fluorescence, micro X-ray absorption near edge structure, full field X-ray microscopes and so on.

Micro rapid prototyping system for micro components

International Nuclear Information System (INIS)

Li Xiaochun; Choi Hongseok; Yang Yong

2002-01-01

Similarities between silicon-based micro-electro-mechanical systems (MEMS) and Shape Deposition Manufacturing (SDM) processes are obvious: both integrate additive and subtractive processes and use part and sacrificial materials to obtain functional structures. These MEMS techniques are two-dimensional (2-D) processes for a limited number of materials while SDM enables the building of parts that have traditionally been impossible to fabricate because of their complex shapes or of their variety in materials. This work presents initial results on the development of a micro rapid prototyping system that adapts SDM methodology to micro-fabrication. This system is designed to incorporate microdeposition and laser micromachining. In the hope of obtaining a precise microdeposition, an ultrasonic-based micro powder-feeding mechanism was developed in order to form thin patterns of dry powders that can be cladded or sintered onto a substrate by a micro-sized laser beam. Furthermore, experimental results on laser micromachining using a laser beam with a wavelength of 355 nm are also presented. After further improvement, the developed micro manufacturing system could take computer-aided design (CAD) output to reproduce 3-D heterogeneous micro-components from a wide selection of materials

GPS-based Microenvironment Tracker (MicroTrac) Model to ...

Science.gov (United States)

A critical aspect of air pollution exposure assessment is the estimation of the time spent by individuals in various microenvironments (ME). Accounting for the time spent in different ME with different pollutant concentrations can reduce exposure misclassifications, while failure to do so can add uncertainty and bias to risk estimates. In this study, a classification model, called MicroTrac, was developed to estimate time of day and duration spent in eight ME (indoors and outdoors at home, work, school; inside vehicles; other locations) from global positioning system (GPS) data and geocoded building boundaries. Based on a panel study, MicroTrac estimates were compared to 24 h diary data from 7 participants on workdays and 2 participants on nonworkdays, with corresponding GPS data and building boundaries of home, school, and work. MicroTrac correctly classified the ME for 99.5% of the daily time spent by the participants. The capability of MicroTrac could help to reduce the time-location uncertainty in air pollution exposure models and exposure metrics for individuals in health studies. The National Exposure Research Laboratory’s (NERL’s) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA’s mission to protect human health and the environment. HEASD’s research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EPA’s strategic plan. More specifically, our division conducts research to characterize

Replication of micro and nano surface geometries

DEFF Research Database (Denmark)

Hansen, Hans Nørgaard; Hocken, R.J.; Tosello, Guido

2011-01-01

The paper describes the state-of-the-art in replication of surface texture and topography at micro and nano scale. The description includes replication of surfaces in polymers, metals and glass. Three different main technological areas enabled by surface replication processes are presented......: manufacture of net-shape micro/nano surfaces, tooling (i.e. master making), and surface quality control (metrology, inspection). Replication processes and methods as well as the metrology of surfaces to determine the degree of replication are presented and classified. Examples from various application areas...... are given including replication for surface texture measurements, surface roughness standards, manufacture of micro and nano structured functional surfaces, replicated surfaces for optical applications (e.g. optical gratings), and process chains based on combinations of repeated surface replication steps....

Multistable wireless micro-actuator based on antagonistic pre-shaped double beams

International Nuclear Information System (INIS)

Liu, X; Lamarque, F; Doré, E; Pouille, P

2015-01-01

This paper presents a monolithic multistable micro-actuator based on antagonistic pre-shaped double beams. The designed micro-actuator is formed by two rows of bistable micro-actuators providing four stable positions. The bistable mechanism for each row is a pair of antagonistic pre-shaped beams. This bistable mechanism has an easier pre-load operation compared to the pre-compressed bistable beams method. Furthermore, it solves the asymmetrical force output problem of parallel pre-shaped bistable double beams. At the same time, the geometrical limit is lower than parallel pre-shaped bistable double beams, which ensures a smaller stroke of the micro-actuator with the same dimensions. The designed micro-actuator is fabricated using laser cutting machine on medium density fiberboard (MDF). The bistability and merits of antagonistic pre-shaped double beams are experimentally validated. Finally, a contactless actuation test is performed using 660 nm wavelength laser heating shape memory alloy (SMA) active elements. (paper)

Multistable wireless micro-actuator based on antagonistic pre-shaped double beams

Science.gov (United States)

Liu, X.; Lamarque, F.; Doré, E.; Pouille, P.

2015-07-01

This paper presents a monolithic multistable micro-actuator based on antagonistic pre-shaped double beams. The designed micro-actuator is formed by two rows of bistable micro-actuators providing four stable positions. The bistable mechanism for each row is a pair of antagonistic pre-shaped beams. This bistable mechanism has an easier pre-load operation compared to the pre-compressed bistable beams method. Furthermore, it solves the asymmetrical force output problem of parallel pre-shaped bistable double beams. At the same time, the geometrical limit is lower than parallel pre-shaped bistable double beams, which ensures a smaller stroke of the micro-actuator with the same dimensions. The designed micro-actuator is fabricated using laser cutting machine on medium density fiberboard (MDF). The bistability and merits of antagonistic pre-shaped double beams are experimentally validated. Finally, a contactless actuation test is performed using 660 nm wavelength laser heating shape memory alloy (SMA) active elements.

Micro-Doppler Ambiguity Resolution Based on Short-Time Compressed Sensing

Directory of Open Access Journals (Sweden)

Jing-bo Zhuang

2015-01-01

Full Text Available When using a long range radar (LRR to track a target with micromotion, the micro-Doppler embodied in the radar echoes may suffer from ambiguity problem. In this paper, we propose a novel method based on compressed sensing (CS to solve micro-Doppler ambiguity. According to the RIP requirement, a sparse probing pulse train with its transmitting time random is designed. After matched filtering, the slow-time echo signals of the micromotion target can be viewed as randomly sparse sampling of Doppler spectrum. Select several successive pulses to form a short-time window and the CS sensing matrix can be built according to the time stamps of these pulses. Then performing Orthogonal Matching Pursuit (OMP, the unambiguous micro-Doppler spectrum can be obtained. The proposed algorithm is verified using the echo signals generated according to the theoretical model and the signals with micro-Doppler signature produced using the commercial electromagnetic simulation software FEKO.

Systematic studies of Australian stipoid grasses (Austrostipa based on micro-morphological and molecular characteristics

Directory of Open Access Journals (Sweden)

BETTY MAULIYA BUSTAM

2010-01-01

Full Text Available Bustam BM (2010 Systematic studies of Australian stipoid grasses (Austrostipa based on micro-morphological and molecular characteristics. Biodiversitas 11: 9-14. This research is one of many studies on stipoid grasses organized by the International Stipeae Working Group (ISWG. This research tested the subgeneric classification of Austrostipa proposed by Jacobs and Everett (1996 and tested how informative the micro morphological characters used. Data were collected from herbarium specimens of 36 species (33 species of Austrostipa, two species of Hesperostipa and one species of Anemanthele at Royal Botanic Gardens, Sydney. Twenty eight micro morphological characters were used. The data were collected from both adaxial and abaxial surfaces of leaves, and from the lemma epidermis using a scanning electron microscope (SEM. ISWG provided the molecular data. Parsimony analysis and a distance method (Unweighteic Pair Group with Arithmatic Mean: UPGMA were used to analyze mico morphological and molecular data separately. Only UPGMA analysis was used to analyze the combined data. The results support the monophyly of Austrostipa. However, there is a little support for the subgeneric classification of Austrostipa proposed by Jacobs and Everett (1996, other than for the consistent recognition of Falcatae. The characters for comparisons between genera are too homoplasious at this level and do not contain enough information for analyses at subgeneric level, a problem apparently shared with the DNA sequences.

Preliminary experimental investigation of a natural gas-fired ORC-based micro-CHP system for residential buildings

International Nuclear Information System (INIS)

Farrokhi, M.; Noie, S.H.; Akbarzadeh, A.A.

2014-01-01

The continual increases in energy demand and greenhouse gas emissions, call for efficient use of energy resources. Decentralized combined heat and power (CHP) technology provides an alternative for the world to meet and solve energy-related problems including energy shortages, energy supply security, emission control and conservation of energy. This paper presents the preliminary results of an experimental investigation of a natural gas-fired micro-CHP system for residential buildings based on an organic Rankine cycle (ORC). Isopentane was used as the ORC working fluid in consideration of several criteria including its environmentally-friendly characteristics. Experiments were conducted to evaluate the performance of the developed system at different heat source temperatures of nominally 85, 80, 75, 70, and 65 °C. The maximum electrical power output of 77.4 W was generated at heating water entry temperature of 84.1 °C, corresponding to net cycle electrical efficiency of 1.66%. Further work will be done with a view to increasing the cycle electrical efficiency by using more efficient components, in particular the expander and generator. - Highlights: •A natural gas-fired ORC-based micro-scale CHP system has been developed and tested. •The good agreement between the mechanical and gross power validates the assumptions. •A vane expander suits a micro-CHP system based on an organic Rankine cycle. •A vane expander does not suit power generation by a Trilateral Flash Cycle (TFC). •Domestic gas-fired ORC systems may reduce reliance on central power stations

Identification of reference genes for relative quantification of circulating microRNAs in bovine serum.

Directory of Open Access Journals (Sweden)

In-Seon Bae

Full Text Available Circulating microRNAs in body fluids have been implicated as promising biomarkers for physiopathology disorders. Currently, the expression levels of circulating microRNAs are estimated by reverse transcription quantitative real-time polymerase chain reaction. Use of appropriate reference microRNAs for normalization is critical for accurate microRNA expression analysis. However, no study has systematically investigated reference genes for evaluating circulating microRNA expression in cattle. In this study, we describe the identification and characterization of appropriate reference microRNAs for use in the normalization of circulating microRNA levels in bovine serum. We evaluated the expression stability of ten candidate reference genes in bovine serum by using reverse transcription quantitative real-time polymerase chain reaction. Data were analyzed using geNorm, NormFinder, and BestKeeper statistical algorithms. The results consistently showed that a combination of miR-93 and miR-127 provided the most stably expressed reference. The suitability of these microRNAs was validated, and even when compared among different genders or breeds, the combination of miR-93 and miR-127 was ranked as the most stable microRNA reference. Therefore, we conclude that this combination is the optimal endogenous reference for reverse transcription quantitative real-time polymerase chain reaction-based detection of microRNAs in bovine serum. The data presented in this study are crucial to successful biomarker discovery and validation for the diagnosis of physiopathological conditions in cattle.

Modelling and control synthesis of a micro-combined heat and power interface for a concentrating solar power system in off-grid rural power applications

Science.gov (United States)

Prinsloo, Gerro; Dobson, Robert; Brent, Alan; Mammoli, Andrea

2016-05-01

Concentrating solar power co-generation systems have been identified as potential stand-alone solar energy supply solutions in remote rural energy applications. This study describes the modelling and synthesis of a combined heat and power Stirling CSP system in order to evaluate its potential performance in small off-grid rural village applications in Africa. This Stirling micro-Combined Heat and Power (micro-CHP) system has a 1 kW electric capacity, with 3 kW of thermal generation capacity which is produced as waste heat recovered from the solar power generation process. As part of the development of an intelligent microgrid control and distribution solution, the Trinum micro-CHP system and other co-generation systems are systematically being modelled on the TRNSYS simulation platform. This paper describes the modelling and simulation of the Trinum micro-CHP configuration on TRNSYS as part of the process to develop the control automation solution for the smart rural microgrid in which the Trinum will serve as a solar powerpack. The results present simulated performance outputs for the Trinum micro-CHP system for a number of remote rural locations in Africa computed from real-time TRNSYS solar irradiation and weather data (yearly, monthly, daily) for the relevant locations. The focus of this paper is on the parametric modelling of the Trinum Stirling micro-CHP system, with specific reference to this system as a TRNSYS functional block in the microgrid simulation. The model is used to forecast the solar energy harvesting potential of the Trinum micro-CHP unit at a number of remote rural sites in Africa.

Simulation and application of micro X-ray fluorescence based on an ellipsoidal capillary

Science.gov (United States)

Yang, Jing; Li, Yude; Wang, Xingyi; Zhang, Xiaoyun; Lin, Xiaoyan

2017-06-01

A micro X-ray fluorescence setup was presented, based on an ellipsoidal capillary and a traditional laboratorial X-ray source. Using Ray-tracing principle, we have simulated the transmission path of X-ray beam in the ellipsoidal capillary and designed the optimal parameters of the ellipsoidal capillary for the micro X-ray fluorescence setup. We demonstrate that ellipsoidal capillary is well suited as condenser for the micro X-ray fluorescence based on traditional laboratorial X-ray source. Furthermore, we obtain the 2D mapping image of the leaf blade sample by using the ellipsoidal capillary we designed.

Smart Energy Management and Control for Fuel Cell Based Micro-Grid Connected Neighborhoods

Energy Technology Data Exchange (ETDEWEB)

Dr. Mohammad S. Alam

2006-03-15

Fuel cell power generation promises to be an efficient, pollution-free, reliable power source in both large scale and small scale, remote applications. DOE formed the Solid State Energy Conversion Alliance with the intention of breaking one of the last barriers remaining for cost effective fuel cell power generation. The Alliance’s goal is to produce a core solid-state fuel cell module at a cost of no more than $400 per kilowatt and ready for commercial application by 2010. With their inherently high, 60-70% conversion efficiencies, significantly reduced carbon dioxide emissions, and negligible emissions of other pollutants, fuel cells will be the obvious choice for a broad variety of commercial and residential applications when their cost effectiveness is improved. In a research program funded by the Department of Energy, the research team has been investigating smart fuel cell-operated residential micro-grid communities. This research has focused on using smart control systems in conjunction with fuel cell power plants, with the goal to reduce energy consumption, reduce demand peaks and still meet the energy requirements of any household in a micro-grid community environment. In Phases I and II, a SEMaC was developed and extended to a micro-grid community. In addition, an optimal configuration was determined for a single fuel cell power plant supplying power to a ten-home micro-grid community. In Phase III, the plan is to expand this work to fuel cell based micro-grid connected neighborhoods (mini-grid). The economic implications of hydrogen cogeneration will be investigated. These efforts are consistent with DOE’s mission to decentralize domestic electric power generation and to accelerate the onset of the hydrogen economy. A major challenge facing the routine implementation and use of a fuel cell based mini-grid is the varying electrical demand of the individual micro-grids, and, therefore, analyzing these issues is vital. Efforts are needed to determine

Ray-based calibration for the micro optical metrology system

Science.gov (United States)

Yin, Yongkai; Wang, Meng; Li, Ameng; Liu, Xiaoli; Peng, Xiang

2014-05-01

Fringe projection 3D microscopy (FP-3DM) plays an important role in micro-machining and micro-fabrication. FP-3DM may be realized with quite different arrangements and principles, which make people confused to select an appropriate one for their specific application. This paper introduces the ray-based general imaging model to describe the FP-3DM, which has the potential to get a unified expression for different system arrangements. Meanwhile the dedicated calibration procedure is also presented to realize quantitative 3D imaging. The validity and accuracy of proposed calibration approach is demonstrated with experiments.

Economical analysis based on a simplified model of micro distillery

International Nuclear Information System (INIS)

Bristoti, A.; Adams, R.

1987-01-01

The investment costs of the hydrate alcohol distillery as well as the energy balance of its production made inviable its diffusion on a small scale. The present economical analysis is based on a simplified model of micro distillery where the reduction on investment costs in based on technical data based on the possibility of the utilization of an hydrate alcohol with a higher water constant than the usual, i. e. around 85 0 GL. The engineering project of this plant eliminates all pumps, all the liquids (water, sugar cane, syrup and wine) are fed by gravity. The bagasse is considered a noble by-product and it is utilized in poultry industry as a substitute of wood dust. All the heat needs of the micro distillery are supplied by wood. (author)

Study on key technologies of vehicle networking system platform for electric automobiles based on micro-service

Science.gov (United States)

Ye, Fei

2018-04-01

With the rapid increase of electric automobiles and charging piles, the elastic expansion and online rapid upgrade were required for the vehicle networking system platform (system platform for short). At present, it is difficult to meet the operation needs due to the traditional huge rock architecture used by the system platform. This paper studied the system platform technology architecture based on "cloud platform +micro-service" to obtain a new generation of vehicle networking system platform with the combination of elastic expansion and application, thus significantly improving the service operation ability of system.

High aspect ratio micro tool manufacturing for polymer replication using mu EDM of silicon, selective etching and electroforming

DEFF Research Database (Denmark)

Tosello, Guido; Bissacco, Giuliano; Tang, Peter Torben

2008-01-01

Mass fabrication of polymer micro components with high aspect ratio micro-structures requires high performance micro tools allowing the use of low cost replication processes such as micro injection moulding. In this regard an innovative process chain, based on a combination of micro electrical di...... discharge machining (mu EDM) of a silicon substrate, electroforming and selective etching was used for the manufacturing of a micro tool. The micro tool was employed for polymer replication by means of the injection moulding process....

Experimental investigation of the tip based micro/nano machining

Science.gov (United States)

Guo, Z.; Tian, Y.; Liu, X.; Wang, F.; Zhou, C.; Zhang, D.

2017-12-01

Based on the self-developed three dimensional micro/nano machining system, the effects of machining parameters and sample material on micro/nano machining are investigated. The micro/nano machining system is mainly composed of the probe system and micro/nano positioning stage. The former is applied to control the normal load and the latter is utilized to realize high precision motion in the xy plane. A sample examination method is firstly introduced to estimate whether the sample is placed horizontally. The machining parameters include scratching direction, speed, cycles, normal load and feed. According to the experimental results, the scratching depth is significantly affected by the normal load in all four defined scratching directions but is rarely influenced by the scratching speed. The increase of scratching cycle number can increase the scratching depth as well as smooth the groove wall. In addition, the scratching tests of silicon and copper attest that the harder material is easier to be removed. In the scratching with different feed amount, the machining results indicate that the machined depth increases as the feed reduces. Further, a cubic polynomial is used to fit the experimental results to predict the scratching depth. With the selected machining parameters of scratching direction d3/d4, scratching speed 5 μm/s and feed 0.06 μm, some more micro structures including stair, sinusoidal groove, Chinese character '田', 'TJU' and Chinese panda have been fabricated on the silicon substrate.

An experimental investigation of heat transfer enhancement in minichannel: Combination of nanofluid and micro fin structure techniques

DEFF Research Database (Denmark)

Zhang, Ji; Diao, Yanhua; Zhao, Yaohua

2017-01-01

This work experimentally studied the single-phase heat transfer and pressure drop characteristics by using two heat transfer enhancement techniques (micro fin structure and nanofluids) in multiport minichannel flat tube (MMFT). MMFT consisted of numerous parallel rectangular minichannels...... and is widely used in industry as the heat transfer unit of a heat exchanger. Firstly, the enhanced heat transfer performances by individually using one enhancement technique were investigated by testing Nusselt number, friction factor and performance evaluation criterion (PEC). In this section, five MMFTs...... with different micro fin numbers (N = 0, 1, 2, 3 and 4) and nanofluids with three volume concentrations (φ = 0.005%, 0.01% and 0.1%) were used as test sections and working fluids respectively. Secondly, the experiments using two combined enhancement technique were performed. By using conjunctively two...

Construction of Silica-Based Micro/Nanoplatforms for Ultrasound Theranostic Biomedicine.

Science.gov (United States)

Zhou, Yang; Han, Xiaoxia; Jing, Xiangxiang; Chen, Yu

2017-09-01

Ultrasound (US)-based biomedicine has been extensively explored for its applications in both diagnostic imaging and disease therapy. The fast development of theranostic nanomedicine significantly promotes the development of US-based biomedicine. This progress report summarizes and discusses the recent developments of rational design and fabrication of silica-based micro/nanoparticles for versatile US-based biomedical applications. The synthetic strategies and surface-engineering approaches of silica-based micro/nanoparticles are initially discussed, followed by detailed introduction on their US-based theranostic applications. They have been extensively explored in contrast-enhanced US imaging, US-based multi-modality imaging, synergistic high-intensity focused US (HIFU) ablation, sonosensitizer-enhanced sonodynamic therapy (SDT), as well as US-triggered chemotherapy. Their biological effects and biosafety have been briefly discussed to guarantee further clinical translation. Based on the high biocompatibility, versatile composition/structure and high performance in US-based theranostic biomedicine, these silica-based theranostic agents are expected to pave a new way for achieving efficient US-based theranostics of disease by taking the specific advantages of material science, nanotechnology and US-based biomedicine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterization of impact materials around Barringer Meteor Crater by micro-PIXE and micro-SRXRF techniques

Energy Technology Data Exchange (ETDEWEB)

Uzonyi, I. E-mail: uzonyi@atomki.hu; Szoeor, Gy.; Rozsa, P.; Vekemans, B.; Vincze, L.; Adams, F.; Drakopoulos, M.; Somogyi, A.; Kiss, A.Z

2004-06-01

A combined micro-PIXE and micro-SRXRF method has been tested successfully for the characterization of impact materials collected at the well-known Barringer Meteor Crater. The micro-PIXE technique proved to be sensitive in the Z{<=}28 atomic number region while the micro-SRXRF above Fe especially for the siderophile elements. Quantitative analysis has become available for about 40 elements by these complementary methods providing new perspectives for the interpretation of the formation mechanism of impact metamorphosed objects.

Hybrid energy fuel cell based system for household applications in a Mediterranean climate

International Nuclear Information System (INIS)

Nižetić, S.; Tolj, I.; Papadopoulos, A.M.

2015-01-01

Highlights: • A hybrid energy system was proposed, combining a HT-PEM fuel cell system and a standard split heat pump system with heat recovery for household applications. • The hybrid energy system is able to produce both high and low temperature heat, electricity and cooling capacity. • The system showed high overall energy efficiency and a favorable environmental aspect. • The calculated cost of overall produced energy proved to be competitive in comparison with the average cost of electricity for households. - Abstract: In this paper, a specific hybrid energy system was proposed for household applications. The hybrid energy system was assembled from a HT-PEM fuel cell stack supplied by hydrogen via a steam reformer, where finally the majority of produced electricity is used to drive a modified split heat pump system with heat recovery (that is enabled via standard modified accumulation boilers). The system is able to produce both high and low temperature heat output (in the form of hot water), cooling thermal output and electricity. Performance analysis was conducted and the specific hybrid energy system showed high value for overall energy efficiency, for the specific case examined it reached 250%. Levelized Cost of Energy (LCOE) analysis was also carried out and the proposed hybrid energy system’s cost is expected to be between 0.09 €/kW h and 0.16 €/kW h, which is certainly competitive with the current retail electricity price for households on the EU market. Additionally, the system also has environmental benefits in relation to reduced CO 2 emissions, as estimated CO 2 emissions from the proposed hybrid energy system are expected to be at around 9.0 gCO 2 /kW h or 2.6 times less than the emissions released from the utilization of grid electricity.

Micro-controller based air pressure monitoring instrumentation system using optical fibers as sensor

Science.gov (United States)

Hazarika, D.; Pegu, D. S.

2013-03-01

This paper describes a micro-controller based instrumentation system to monitor air pressure using optical fiber sensors. The principle of macrobending is used to develop the sensor system. The instrumentation system consists of a laser source, a beam splitter, two multi mode optical fibers, two Light Dependent Resistance (LDR) based timer circuits and a AT89S8252 micro-controller. The beam splitter is used to divide the laser beam into two parts and then these two beams are launched into two multi mode fibers. One of the multi mode fibers is used as the sensor fiber and the other one is used as the reference fiber. The use of the reference fiber is to eliminate the environmental effects while measuring the air pressure magnitude. The laser beams from the sensor and reference fibers are applied to two identical LDR based timer circuits. The LDR based timer circuits are interfaced to a micro-controller through its counter pins. The micro-controller samples the frequencies of the timer circuits using its counter-0 and counter-1 and the counter values are then processed to provide the measure of air pressure magnitude.

Micro-tribological properties of hydroxyapatite-based composites in dry sliding

International Nuclear Information System (INIS)

Lu, Zhi; Liu, Yong; Liu, Bowei; Liu, Meiling

2013-01-01

Highlights: ► The micro-tribological properties of HA-based composites were investigated. ► The micro-scale test is greatly benefits to the analyses of the wear mechanism. ► A higher speed benefits the formation of the lubricating layer, when high in Cu. ► With increasing Cu, the wear mechanism shift from abrasive wear to adhesive wear. - Abstract: The micro-tribological properties of hydroxyapatite-based composites sliding against alumina balls were investigated by a ball-on-block tribometer. Surface properties of the HA-based composites were measured and examined by using atomic force microscopy and scanning electron microscopy. Running-in behavior during sliding tests was studied as a function of surface properties. The effects of copper fibers, initial surface roughness, and sliding velocity on the friction coefficient and the wear resistance were discussed. Results show that a lubricant layer benefits the tribological properties of the composites. With the increasing of Cu, the lubricant layer is more stable, and resistant to increase of the sliding velocity. At a Cu content of 15%, the wear curve is very stable even at a velocity of 900 rpm. The wear mechanism also changes from abrasive wear to adhesive wear. A model was quoted to describe the relationship between the wear resistant and the load

Intelligent Control of Micro Grid: A Big Data-Based Control Center

Science.gov (United States)

Liu, Lu; Wang, Yanping; Liu, Li; Wang, Zhiseng

2018-01-01

In this paper, a structure of micro grid system with big data-based control center is introduced. Energy data from distributed generation, storage and load are analized through the control center, and from the results new trends will be predicted and applied as a feedback to optimize the control. Therefore, each step proceeded in micro grid can be adjusted and orgnized in a form of comprehensive management. A framework of real-time data collection, data processing and data analysis will be proposed by employing big data technology. Consequently, a integrated distributed generation and a optimized energy storage and transmission process can be implemented in the micro grid system.

Experimental study of micro dimple fabrication based on laser shock processing

Science.gov (United States)

Li, Kangmei; Hu, Yongxiang; Yao, Zhenqiang

2013-06-01

Micro-dimple array has been generally considered as a valuable texture for sliding surfaces. It can improve lubrication and reduce wear by acting as reservoirs of lubricants and grinding debris. Laser shock processing (LSP) is an innovative process which can not only improve fatigue, corrosion and wearing resistance but also shape metallic parts accurately. In this study, a new process for the fabrication of micro dimples based on LSP was proposed, which was named as laser peen texturing (LPT). Experiments were performed on 2024 aluminum alloy, Oxygen-Free High Conductivity (OFHC) copper and SUS304 stainless steel to study the effects of processing parameters of LPT on surface integrity of the specimen. Surface morphology, micro hardness and microstructure of the micro dimples were investigated under various laser power densities, laser spot diameters and repeated shock numbers. It was found that the depth of the micro dimples induced by LPT is strongly dependent on material properties. The diameter, depth as well as aspect ratio of micro dimples were increased with the laser power density and the repeated shock number under the conditions in this study. But when the laser spot diameter changed, the variation laws of the diameter, depth and aspect ratio of the dimple were different from each other. The results of micro hardness measurements suggested that LPT is beneficial for the improvement of the micro hardness beneath the dimple. Grain refinement was found significantly on 2024 aluminum alloy and OFHC copper but not clearly on SUS304 stainless steel. Both the hardening effect and the grain refinement have close relationship with the depth of the micro dimple.

CC_TRS: Continuous Clustering of Trajectory Stream Data Based on Micro Cluster Life

Directory of Open Access Journals (Sweden)

Musaab Riyadh

2017-01-01

Full Text Available The rapid spreading of positioning devices leads to the generation of massive spatiotemporal trajectories data. In some scenarios, spatiotemporal data are received in stream manner. Clustering of stream data is beneficial for different applications such as traffic management and weather forecasting. In this article, an algorithm for Continuous Clustering of Trajectory Stream Data Based on Micro Cluster Life is proposed. The algorithm consists of two phases. There is the online phase where temporal micro clusters are used to store summarized spatiotemporal information for each group of similar segments. The clustering task in online phase is based on temporal micro cluster lifetime instead of time window technique which divides stream data into time bins and clusters each bin separately. For offline phase, a density based clustering approach is used to generate macro clusters depending on temporal micro clusters. The evaluation of the proposed algorithm on real data sets shows the efficiency and the effectiveness of the proposed algorithm and proved it is efficient alternative to time window technique.

Depth of array micro-holes with large aspect ratio in Al based cast alloy

Science.gov (United States)

Jin, Meiling; Qu, Yingdong; Li, Rongde

2018-03-01

In order to study on the depth of array micro-holes on Al base cast alloy, micro-hole with depth of 50 mm and diameter of 0.55 mm are successfully prepared by using poor wetting between carbon and Al. Accordingly, the mold of depth is established, the results show that calculated depth of micro-hole is 53.22 mm, relative error is 6% compare with the actual measured depth, and the depth of hole exponentially increases with the increasing of distance between two micro-holes. Surface tension and metallostatic pressure of metal molten are mainly affecting factors for depth of micro-holes.

Combined use of infrared and hard X-ray microprobes for spectroscopy-based neuroanatomy

Science.gov (United States)

Surowka, A. D.; Ziomber, A.; Czyzycki, M.; Migliori, A.; Pieklo, L.; Kasper, K.; Szczerbowska-Boruchowska, M.

2018-05-01

Understanding the pathological triggers that affect the structural and physiological integrity of biochemical milieu of neurons is crucial to extend our knowledge on brain disorders, that are in many circumstances hardly treatable. Over recently, by using sophisticated hyperspectral micro-imaging modalities, it has been placed within our reach to get an insight into high fidelity histological details along with corresponding biochemical information in a label-free fashion, without using any additional chemical fixatives. However, in order to push forwards extensive application of these methods in the clinical arena, it is viable to make further iterations in novel data analysis protocols in order to boost their sensitivity. Therefore, in our study we proposed a new combined approach utilizing both benchtop Fourier transform infrared (FTIR) and synchrotron X-ray fluorescence (SR-XRF) micro-spectroscopies coupled with multivariate data clustering using the K-means algorithm for combined molecular and elemental micro-imaging, so that these complimentary analytical tools could be used for delineating between various brain structures based on their biochemical composition. By utilizing mid-IR transmission FTIR experiments, the biochemical composition in terms of lipids, proteins and phosphodiesters became accessible. In turn, the SR-XRF experiment was carried out at the advanced IAEA X-ray spectrometry station at Elettra Sincrotrone Trieste. By measuring in vacuum and by using the primary exciting X-ray beam, monochromatized to 10.5 keV, we took advantage of accessing the characteristic X-ray lines of a variety of elements ranging from carbon to zinc. Herein, we can report that the developed methodology has high specificity for label-free discriminating between lipid- and protein-rich brain tissue areas.

Graphene-based in-plane micro-supercapacitors with high power and energy densities.

Science.gov (United States)

Wu, Zhong-Shuai; Parvez, Khaled; Feng, Xinliang; Müllen, Klaus

2013-01-01

Micro-supercapacitors are important on-chip micro-power sources for miniaturized electronic devices. Although the performance of micro-supercapacitors has been significantly advanced by fabricating nanostructured materials, developing thin-film manufacture technologies and device architectures, their power or energy densities remain far from those of electrolytic capacitors or lithium thin-film batteries. Here we demonstrate graphene-based in-plane interdigital micro-supercapacitors on arbitrary substrates. The resulting micro-supercapacitors deliver an area capacitance of 80.7 μF cm⁻² and a stack capacitance of 17.9 F cm⁻³. Further, they show a power density of 495 W cm⁻³ that is higher than electrolytic capacitors, and an energy density of 2.5 mWh cm⁻³ that is comparable to lithium thin-film batteries, in association with superior cycling stability. Such microdevices allow for operations at ultrahigh rate up to 1,000 V s⁻¹, three orders of magnitude higher than that of conventional supercapacitors. Micro-supercapacitors with an in-plane geometry have great promise for numerous miniaturized or flexible electronic applications.

Graphene-based in-plane micro-supercapacitors with high power and energy densities

Science.gov (United States)

Wu, Zhong–Shuai; Parvez, Khaled; Feng, Xinliang; Müllen, Klaus

2013-01-01

Micro-supercapacitors are important on-chip micro-power sources for miniaturized electronic devices. Although the performance of micro-supercapacitors has been significantly advanced by fabricating nanostructured materials, developing thin-film manufacture technologies and device architectures, their power or energy densities remain far from those of electrolytic capacitors or lithium thin-film batteries. Here we demonstrate graphene-based in-plane interdigital micro-supercapacitors on arbitrary substrates. The resulting micro-supercapacitors deliver an area capacitance of 80.7 μF cm−2 and a stack capacitance of 17.9 F cm−3. Further, they show a power density of 495 W cm−3 that is higher than electrolytic capacitors, and an energy density of 2.5 mWh cm−3 that is comparable to lithium thin-film batteries, in association with superior cycling stability. Such microdevices allow for operations at ultrahigh rate up to 1,000 V s−1, three orders of magnitude higher than that of conventional supercapacitors. Micro-supercapacitors with an in-plane geometry have great promise for numerous miniaturized or flexible electronic applications. PMID:24042088

Nanotechnology-Based Detection of Novel microRNAs for Early Diagnosis of Prostate Cancer

Science.gov (United States)

2017-08-01

AWARD NUMBER: W81XWH-15-1-0157 TITLE: Nanotechnology -Based Detection of Novel microRNAs for Early Diagnosis of Prostate Cancer PRINCIPAL...TITLE AND SUBTITLE Nanotechnology -Based Detection of Novel microRNAs for Early Diagnosis of Prostate Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER...identify novel differentially expressed miRNAs in the body fluids (blood, urine, etc.) for an early detection of PCa. Advances in nanotechnology and

Research on a Micro-Grid Frequency Modulation Strategy Based on Optimal Utilization of Air Conditioners

Directory of Open Access Journals (Sweden)

Qingzhu Wan

2016-12-01

Full Text Available With the proportion of air conditioners increasing gradually, they can provide a certain amount of frequency-controlled reserves for a micro-grid. Optimizing utilization of air conditioners and considering load response characteristics and customer comfort, the frequency adjustment model is a quadratic function model between the trigger temperature of the air conditioner compressor, and frequency variation is provided, which can be used to regulate the trigger temperature of the air conditioner when the micro-grid frequency rises and falls. This frequency adjustment model combines a primary frequency modulation method and a secondary frequency modulation method of the energy storage system, in order to optimize the frequency of a micro-grid. The simulation results show that the frequency modulation strategy for air conditioners can effectively improve the frequency modulation ability of air conditioners and frequency modulation effects of a micro-grid in coordination with an energy storage system.

Why Micro-foundations for Resource-Based Theory Are Needed and What They May Look Like

DEFF Research Database (Denmark)

Foss, Nicolai Juul

2011-01-01

One of the important events in the development of resource-based theory (RBT) over the past decade has been the call for establishing micro-foundations for RBT. However, the micro-foundations project is still largely an unfulfilled promise. This article clarifies the nature of the micro-foundatio...

Research on SOI-based micro-resonator devices

Science.gov (United States)

Xiao, Xi; Xu, Haihua; Hu, Yingtao; Zhou, Liang; Xiong, Kang; Li, Zhiyong; Li, Yuntao; Fan, Zhongchao; Han, Weihua; Yu, Yude; Yu, Jinzhong

2010-10-01

SOI (silicon-on-insulator)-based micro-resonator is the key building block of silicon photonics, which is considered as a promising solution to alleviate the bandwidth bottleneck of on-chip interconnects. Silicon-based sub-micron waveguide, microring and microdisk devices are investigated in Institute of Semiconductors, Chinese Academy of Sciences. The main progress in recent years is presented in this talk, such as high Q factor single mode microdisk filters, compact thirdorder microring filters with the through/drop port extinctions to be ~ 30/40 dB, fast microring electro-optical switches with the switch time of 10 Gbit/s high speed microring modulators.

Grounding new institutional theory on a micro-sociological and practice-based foundation - exploring models of translation

DEFF Research Database (Denmark)

Scheuer, John Damm

interested in explaining how and why ideas travel in and out of organizations and become institutionalized in organizational fields. More specifically the paper focuses on the way actor-network theory and the concept of translation have been translated by researchers trying to understand institutionalization......Institutional and more practice-based perspectives on organizing and change are increasingly being combined in order to understand the micro-processes on which institutional "orders" are built and changed. The aim of this paper is to analyze how this work is done in practice by researchers...... processes related to ideas that travel from one place in time and space to another. The paper suggests that combining the concept of translation and theories about institutional change will make it possible to ground macro-sociological claims about how ideas travel and become institutionalized...

Fertilizer micro-dosing

International Development Research Centre (IDRC) Digital Library (Canada)

Localized application of small quantities of fertilizer (micro-dosing), combined with improved planting pits for rainwater harvesting, has generated greater profits and food security for women farmers in the Sahel. • Women are 25% more likely to use combined applications, and have expanded areas of food crops (cowpea,.

Laser carved micro-crack channels in paper-based dilution devices.

Science.gov (United States)

Liu, Qian; Xu, Chaoping; Liang, Heng

2017-12-01

We developed novel laser carved micro-crack (LCC) paper-based channels to significantly accelerate the liquid flow without an external pump. For the aqueous solutions they increased the flow velocity 59 times in 16% laser power-8 micro-cracks-LCC channel compared with it in solely-printed channels. All experimental data from both LCC and solely-printed channels were well-fitted by the time-distance quadratic trinomial that we developed on laser power and micro-crack number. We designed and fabricated T-junction microstructures of LCCs. Further, the microfluidic paper-based analytical device (μPAD) of LCC on dye mixing gradient and pH gradient were developed with the characteristics, fast self-acting transportation and high-performance mixing of liquid flows. In the dye mixing gradient the time cost was reduced from 2355s in the solely-printed one to only 123s in the five-stage of this LCC-μPAD. It was useful for quick and long-distance transferences through the multiple units of μPADs. Certainly, this LCC-μPAD was inexpensive, disposable, portable and applicable to resource-limited environments. Copyright © 2017 Elsevier B.V. All rights reserved.

[A micro-silicon multi-slit spectrophotometer based on MEMS technology].

Science.gov (United States)

Hao, Peng; Wu, Yi-Hui; Zhang, Ping; Liu, Yong-Shun; Zhang, Ke; Li, Hai-Wen

2009-06-01

A new mini-spectrophotometer was developed by adopting micro-silicon slit and pixel segmentation technology, and this spectrophotometer used photoelectron diode array as the detector by the back-dividing-light way. At first, the effect of the spectral bandwidth on the tested absorbance linear correlation was analyzed. A theory for the design of spectrophotometer's slit was brought forward after discussing the relationships between spectrophotometer spectrum band width and pre-and post-slits width. Then, the integrative micro-silicon-slit, which features small volume, high precision, and thin thickness, was manufactured based on the MEMS technology. Finally, a test was carried on linear absorbance solution by this spectrophotometer. The final result showed that the correlation coefficients were larger than 0.999, which means that the new mini-spectrophotometer with micro-silicon slit pixel segmentation has an obvious linear correlation.

Investigation of Size-Dependency in Free-Vibration of Micro-Resonators Based on the Strain Gradient Theory

Directory of Open Access Journals (Sweden)

R. Vatankhah

Full Text Available Abstract This paper investigates the vibration behavior of micro-resonators based on the strain gradient theory, a non-classical continuum theory capable of capturing the size effect appearing in micro-scale structures. The micro-resonator is modeled as a clamped-clamped micro-beam with an attached mass subjected to an axial force. The governing equations of motion and both classical and non-classical sets of boundary conditions are developed based on the strain gradient theory. The normalized natural frequency of the micro-resonator is evaluated and the influences of various parameters are assessed. In addition, the current results are compared to those of the classical and modified couple stress continuum theories.

Elastocapillary self-folding of micro-machined structures: capillary origami

NARCIS (Netherlands)

Legrain, A.B.H.

2014-01-01

Standard lithographic techniques have proven to be inadequate at machining true 3D micro-structures - structures with similar dimensions in all directions or with large height to width ratio. New fabrication paradigms are necessary. Combining the assets of mask-based techniques with self-assembly,

Experimental study of micro-milling mechanism and surface quality of a nickel-based single crystal superalloy

Energy Technology Data Exchange (ETDEWEB)

Gao, Qi; Gong, Yadong; Zhou, Yun Guang; Wen, Xue Long [School of Mechanical Engineering and Automation, Northeastern University, Shenyang (China)

2017-01-15

Micro-milling is widely used as a method for machining of micro-parts with high precision and efficiency. Taking the nickel-based single-crystal superalloy DD98 as the research object, the crystal characteristics of single-crystal materials were analysed, and the removal mechanism of single-crystal micro-milled parts was described. Based on molecular dynamics, a simulation model for nickel-based single-crystal superalloy DD98 micro-milling was established. Based on the response surface method of central composite design, the influences of spindle speed, feed rate, and milling depth on the surface roughness were examined, and a second-order regression model of the DD98 surface roughness was established. Using analysis of variance and the residuals of the model, a significant influence on surface roughness was found in the following order from large to small: Feed rate, spindle speed, and milling depth. Comparisons were conducted between the micro-milling experimental values and the predicted model values for different process parameters. The results show that the model fit is relatively high, and the adaptability is good. Scanning electron microscopy analysis of the micro-milling surfaces was performed to verify the slip and the removal mechanism of single-crystal materials. These results offer a theoretical reference and experimental basis for micro-milling of single-crystal materials.

The analysis of novel microRNA mimic sequences in cancer cells reveals lack of specificity in stem-loop RT-qPCR-based microRNA detection.

Science.gov (United States)

Winata, Patrick; Williams, Marissa; McGowan, Eileen; Nassif, Najah; van Zandwijk, Nico; Reid, Glen

2017-11-17

MicroRNAs are frequently downregulated in cancer, and restoring expression has tumour suppressive activity in tumour cells. Our recent phase I clinical trial investigated microRNA-based therapy in patients with malignant pleural mesothelioma. Treatment with TargomiRs, microRNA mimics with novel sequence packaged in EGFR antibody-targeted bacterial minicells, revealed clear signs of clinical activity. In order to detect delivery of microRNA mimics to tumour cells in future clinical trials, we tested hydrolysis probe-based assays specific for the sequence of the novel mimics in transfected mesothelioma cell lines using RT-qPCR. The custom assays efficiently and specifically amplified the consensus mimics. However, we found that these assays gave a signal when total RNA from untransfected and control mimic-transfected cells were used as templates. Further investigation revealed that the reverse transcription step using stem-loop primers appeared to introduce substantial non-specific amplification with either total RNA or synthetic RNA templates. This suggests that reverse transcription using stem-loop primers suffers from an intrinsic lack of specificity for the detection of highly similar microRNAs in the same family, especially when analysing total RNA. These results suggest that RT-qPCR is unlikely to be an effective means to detect delivery of microRNA mimic-based drugs to tumour cells in patients.

In-situ, real time micro-CT imaging of pore scale processes, the next frontier for laboratory based micro-CT scanning

OpenAIRE

Boone, Marijn; Bultreys, Tom; Masschaele, Bert; Van Loo, Denis; Van Hoorebeke, Luc; Cnudde, Veerle

2016-01-01

Over the past decade, laboratory based X-ray computed micro-tomography (micro-CT) has given unique insights in the internal structure of complex reservoir rocks, improving the understanding of pore scale processes and providing crucial information for pore scale modelling. Especially in-situ imaging using X-ray optimized Hassler type cells has enabled the direct visualization of fluid distributions at the pore scale under reservoir conditions. While sub-micrometre spatial resolutions are achi...

Micro Vision

OpenAIRE

Ohba, Kohtaro; Ohara, Kenichi

2007-01-01

In the field of the micro vision, there are few researches compared with macro environment. However, applying to the study result for macro computer vision technique, you can measure and observe the micro environment. Moreover, based on the effects of micro environment, it is possible to discovery the new theories and new techniques.

High-performance piezoelectric thick film based energy harvesting micro-generators for MEMS

DEFF Research Database (Denmark)

Zawada, Tomasz; Hansen, Karsten; Lou-Moeller, Rasmus

2010-01-01

and are transformed by the energy harvesting micro-generator into usable electrical signal. The micro-generator comprises a silicon cantilever with integrated InSensor® TF2100 PZT thick film deposited using screen-printing. The output power versus frequency and electrical load has been investigated. Furthermore......, devices based on modified, pressure treated thick film materials have been tested and compared with the commercial InSensor® TF2100 PZT thick films. It has been found that the structures based on the pressure treated materials exhibit superior properties in terms of energy output....

Levitating Micro-Actuators: A Review

Directory of Open Access Journals (Sweden)

Kirill V. Poletkin

2018-04-01

Full Text Available Through remote forces, levitating micro-actuators completely eliminate mechanical attachment between the stationary and moving parts of a micro-actuator, thus providing a fundamental solution to overcoming the domination of friction over inertial forces at the micro-scale. Eliminating the usual mechanical constraints promises micro-actuators with increased operational capabilities and low dissipation energy. Further reduction of friction and hence dissipation by means of vacuum leads to dramatic increases of performance when compared to mechanically tethered counterparts. In order to efficiently employ the benefits provided by levitation, micro-actuators are classified according to their physical principles as well as by their combinations. Different operating principles, structures, materials and fabrication methods are considered. A detailed analysis of the significant achievements in the technology of micro-optics, micro-magnets and micro-coil fabrication, along with the development of new magnetic materials during recent decades, which has driven the creation of new application domains for levitating micro-actuators is performed.

Integrating macro and micro scale approaches in the agent-based modeling of residential dynamics

Science.gov (United States)

Saeedi, Sara

2018-06-01

With the advancement of computational modeling and simulation (M&S) methods as well as data collection technologies, urban dynamics modeling substantially improved over the last several decades. The complex urban dynamics processes are most effectively modeled not at the macro-scale, but following a bottom-up approach, by simulating the decisions of individual entities, or residents. Agent-based modeling (ABM) provides the key to a dynamic M&S framework that is able to integrate socioeconomic with environmental models, and to operate at both micro and macro geographical scales. In this study, a multi-agent system is proposed to simulate residential dynamics by considering spatiotemporal land use changes. In the proposed ABM, macro-scale land use change prediction is modeled by Artificial Neural Network (ANN) and deployed as the agent environment and micro-scale residential dynamics behaviors autonomously implemented by household agents. These two levels of simulation interacted and jointly promoted urbanization process in an urban area of Tehran city in Iran. The model simulates the behavior of individual households in finding ideal locations to dwell. The household agents are divided into three main groups based on their income rank and they are further classified into different categories based on a number of attributes. These attributes determine the households' preferences for finding new dwellings and change with time. The ABM environment is represented by a land-use map in which the properties of the land parcels change dynamically over the simulation time. The outputs of this model are a set of maps showing the pattern of different groups of households in the city. These patterns can be used by city planners to find optimum locations for building new residential units or adding new services to the city. The simulation results show that combining macro- and micro-level simulation can give full play to the potential of the ABM to understand the driving

Formation of Micro and Mesoporous Amorphous Silica-Based Materials from Single Source Precursors

Directory of Open Access Journals (Sweden)

Mohd Nazri Mohd Sokri

2016-03-01

Full Text Available Polysilazanes functionalized with alkoxy groups were designed and synthesized as single source precursors for fabrication of micro and mesoporous amorphous silica-based materials. The pyrolytic behaviors during the polymer to ceramic conversion were studied by the simultaneous thermogravimetry-mass spectrometry (TG-MS analysis. The porosity of the resulting ceramics was characterized by the N2 adsorption/desorption isotherm measurements. The Fourier transform infrared spectroscopy (FT-IR and Raman spectroscopic analyses as well as elemental composition analysis were performed on the polymer-derived amorphous silica-based materials, and the role of the alkoxy group as a sacrificial template for the micro and mesopore formations was discussed from a viewpoint to establish novel micro and mesoporous structure controlling technologies through the polymer-derived ceramics (PDCs route.

Micro-Doppler Feature Extraction and Recognition Based on Netted Radar for Ballistic Targets

Directory of Open Access Journals (Sweden)

Feng Cun-qian

2015-12-01

Full Text Available This study examines the complexities of using netted radar to recognize and resolve ballistic midcourse targets. The application of micro-motion feature extraction to ballistic mid-course targets is analyzed, and the current status of application and research on micro-motion feature recognition is concluded for singlefunction radar networks such as low- and high-resolution imaging radar networks. Advantages and disadvantages of these networks are discussed with respect to target recognition. Hybrid-mode radar networks combine low- and high-resolution imaging radar and provide a specific reference frequency that is the basis for ballistic target recognition. Main research trends are discussed for hybrid-mode networks that apply micromotion feature extraction to ballistic mid-course targets.

Coronary artery wall imaging in mice using osmium tetroxide and micro-computed tomography (micro-CT)

International Nuclear Information System (INIS)

Pai, Vinay M.; Kozlowski, Megan; Donahue, Danielle; Miller, Elishiah; Xiao, Xianghui; Chen, Marcus Y.; Yu, Zu-Xi; Connelly, Patricia; Jeffries, Kenneth; Wen, Han

2012-01-01

The high spatial resolution of micro-computed tomography (micro-CT) is ideal for 3D imaging of coronary arteries in intact mouse heart specimens. Previously, micro-CT of mouse heart specimens utilized intravascular contrast agents that hardened within the vessel lumen and allowed a vascular cast to be made. However, for mouse coronary artery disease models, it is highly desirable to image coronary artery walls and highlight plaques. For this purpose, we describe an ex vivo contrast-enhanced micro-CT imaging technique based on tissue staining with osmium tetroxide (OsO 4 ) solution. As a tissue-staining contrast agent, OsO 4 is retained in the vessel wall and surrounding tissue during the fixation process and cleared from the vessel lumens. Its high X-ray attenuation makes the artery wall visible in CT. Additionally, since OsO 4 preferentially binds to lipids, it highlights lipid deposition in the artery wall. We performed micro-CT of heart specimens of 5- to 25-week-old C57BL/6 wild-type mice and 5- to 13-week-old apolipoprotein E knockout (apoE -/- ) mice at 10 μm resolution. The results show that walls of coronary arteries as small as 45 μm in diameter are visible using a table-top micro-CT scanner. Similar image clarity was achieved with 1/2000th the scan time using a synchrotron CT scanner. In 13-week-old apoE mice, lipid-rich plaques are visible in the aorta. Our study shows that the combination of OsO 4 and micro-CT permits the visualization of the coronary artery wall in intact mouse hearts.

Development of micro controller-based monitoring system for a ...

African Journals Online (AJOL)

Development of micro controller-based monitoring system for a stand-alone ... which are then processed by a microcontroller with Arduino Board and the ... used in meteorological stations and laboratory for measurements of the same parameters. ... 0.0412%,-0.297% and 0.024% for solar radiation intensity, temperature, ...

Ferrofluid based micro-electrical energy harvesting

Science.gov (United States)

Purohit, Viswas; Mazumder, Baishakhi; Jena, Grishma; Mishra, Madhusha; Materials Department, University of California, Santa Barbara, CA93106 Collaboration

2013-03-01

Innovations in energy harvesting have seen a quantum leap in the last decade. With the introduction of low energy devices in the market, micro energy harvesting units are being explored with much vigor. One of the recent areas of micro energy scavenging is the exploitation of existing vibrational energy and the use of various mechanical motions for the same, useful for low power consumption devices. Ferrofluids are liquids containing magnetic materials having nano-scale permanent magnetic dipoles. The present work explores the possibility of the use of this property for generation of electricity. Since the power generation is through a liquid material, it can take any shape as well as response to small acceleration levels. In this work, an electromagnet-based micropower generator is proposed to utilize the sloshing of the ferrofluid within a controlled chamber which moves to different low frequencies. As compared to permanent magnet units researched previously, ferrofluids can be placed in the smallest of containers of different shapes, thereby giving an output in response to the slightest change in motion. Mechanical motion from 1- 20 Hz was able to give an output voltage in mV's. In this paper, the efficiency and feasibility of such a system is demonstrated.

Camera-based micro interferometer for distance sensing

Science.gov (United States)

Will, Matthias; Schädel, Martin; Ortlepp, Thomas

2017-12-01

Interference of light provides a high precision, non-contact and fast method for measurement method for distances. Therefore this technology dominates in high precision systems. However, in the field of compact sensors capacitive, resistive or inductive methods dominates. The reason is, that the interferometric system has to be precise adjusted and needs a high mechanical stability. As a result, we have usual high-priced complex systems not suitable in the field of compact sensors. To overcome these we developed a new concept for a very small interferometric sensing setup. We combine a miniaturized laser unit, a low cost pixel detector and machine vision routines to realize a demonstrator for a Michelson type micro interferometer. We demonstrate a low cost sensor smaller 1cm3 including all electronics and demonstrate distance sensing up to 30 cm and resolution in nm range.

TU-H-CAMPUS-TeP2-03: High Sensitivity and High Resolution Fiber Based Micro-Detector for Sub-Millimeter Preclinical Dosimetry

International Nuclear Information System (INIS)

Izaguirre, E; Pokhrel, S; Knewtson, T; Hedrick, S

2016-01-01

Purpose: Current precision of small animal and cell micro-irradiators has continuously increased during the past years. Currently, preclinical irradiators can deliver sub-millimeter fields with micrometric precision but there are no water equivalent dosimeters to determine small field profiles and dose in the orthovoltage range of energies with micrometric resolution and precision. We have developed a fiber based micro-dosimeter with the resolution and dosimetric accuracy required for radiobiological research. Methods: We constructed two prototypes of micro-dosimeters based on different compositions of fiber scintillators to study the spatial resolution and dosimetric precision of small animal and cell micro-irradiators. The first has green output and the second has blue output. The blue output dosimeter has the highest sensitivity because it matches the spectral sensitivity of silicon photomultipliers. A blue detector with 500um cross section was built and tested respect to a CC01 ion chamber, film, and the 1500um green output detector. Orthovoltage fields from 1×1mm2 to 5×5mm2 were used for detector characteristics comparison. Results: The blue fiber dosimeter shows great agreement with films and matches dose measurements with the gold-standard ion chamber for 5×5mm2 fields. The detector has the appropriate sensitivity to measure fields from 1×1mm2 to larger sizes with a 1% dosimetric accuracy. The spatial resolution is in the sub-millimeter range and the spectral matching with the photomultiplier allows reducing the sensor cross section even further than the presented prototype. These results suggest that scintillating fibers combined with silicon photomultipliers is the appropriate technology to pursue micro-dosimetry for small animals and disperse cell samples. Conclusion: The constructed detectors establish a new landmark for the resolution and sensitivity of fiber based microdetectors. The validation of the detector in our small animal and cell

Structural vibration control of micro/macro-manipulator using feedforward and feedback approaches

International Nuclear Information System (INIS)

Lew, J.Y.; Cannon, D.W.; Magee, D.P.; Book, W.J.

1995-09-01

Pacific Northwest Laboratory (PDL) researchers investigated the combined use of two control approaches to minimize micro/macro-manipulator structural vibration: (1) modified input shaping and (2) inertial force active damping control. Modified input shaping (MIS) is used as a feedforward controller to modify reference input by canceling the vibratory motion. Inertial force active damping (IFAD) is applied as a feedback controller to increase the system damping and robustness to unexpected disturbances. Researchers implemented both control schemes in the PNL micro/macro flexible-link manipulator testbed collaborating with Georgia Institute of Technology. The experiments successfully demonstrated the effectiveness of two control approaches in reducing structural vibration. Based on the results of the experiments, the combined use of two controllers is recommended for a micro/macro manipulator to achieve the fastest response to commands while canceling disturbances from unexpected forces

TiAu-based micro-calorimeters for space applications

International Nuclear Information System (INIS)

Dirks, B.P.F.; Popescu, M.; Bruijn, M.; Gottardi, L.; Hoevers, H.F.C.; Korte, P.A.J. de; Kuur, J. van der; Ridder, M.; Takei, Y.

2009-01-01

We present the latest results of the performance of micro-calorimeters based on transition edge sensors (TESs) for space applications. Sensors based on TiAu superconductive layers with Cu/Bi absorbers are discussed and have been characterized. Different coupling schemes between absorber and TES have been tested leading to an optimal (preferred) design for a new batch of arrays. We discuss the progress on array development for the International X-ray Observatory (IXO) in terms of pixel uniformity and filling factor. Inter-pixel cross-talk is discussed as well.

micro-mechanical experimental investigation and modelling of strain and damage of argillaceous rocks under combined hydric and mechanical loads

International Nuclear Information System (INIS)

Wang, L.

2012-01-01

The hydro-mechanical behavior of argillaceous rocks, which are possible host rocks for underground radioactive nuclear waste storage, is investigated by means of micro-mechanical experimental investigations and modellings. Strain fields at the micrometric scale of the composite structure of this rock, are measured by the combination of environmental scanning electron microscopy, in situ testing and digital image correlation technique. The evolution of argillaceous rocks under pure hydric loading is first investigated. The strain field is strongly heterogeneous and manifests anisotropy. The observed nonlinear deformation at high relative humidity (RH) is related not only to damage, but also to the nonlinear swelling of the clay mineral itself, controlled by different local mechanisms depending on RH. Irreversible deformations are observed during hydric cycles, as well as a network of microcracks located in the bulk of the clay matrix and/or at the inclusion-matrix interface. Second, the local deformation field of the material under combined hydric and mechanical loadings is quantified. Three types of deformation bands are evidenced under mechanical loading, either normal to stress direction (compaction), parallel (microcracking) or inclined (shear). Moreover, they are strongly controlled by the water content of the material: shear bands are in particular prone to appear at high RH states. In view of understanding the mechanical interactions a local scale, the material is modeled as a composite made of non-swelling elastic inclusions embedded in an elastic swelling clay matrix. The internal stress field induced by swelling strain incompatibilities between inclusions and matrix, as well as the overall deformation, is numerically computed at equilibrium but also during the transient stage associated with a moisture gradient. An analytical micro-mechanical model based on Eshelby's solution is proposed. In addition, 2D finite element computations are performed. Results

Development of GaN-based micro chemical sensor nodes

Science.gov (United States)

Son, Kyung-ah; Prokopuk, Nicholas; George, Thomas; Moon, Jeong S.

2005-01-01

Sensors based on III-N technology are gaining significant interest due to their potential for monolithic integration of RF transceivers and light sources and the capability of high temperature operations. We are developing a GaN-based micro chemical sensor node for remote detection of chemical toxins, and present electrical responses of AlGaN/GaN HEMT (High Electron Mobility Transistor) sensors to chemical toxins as well as other common gases.

Micro scale CHP based on biomass intelligent heat transfer with thermoelectric generators

Energy Technology Data Exchange (ETDEWEB)

Moser, W.; Aigenbauer, S.; Heckmann, M.; Friedl, G. (Austrian Bioenergy Centre GmbH, Wieselburg (Austria)); Hofbauer, H. (Institute of Chemical Engineering, Vienna University of Technology (Austria))

2007-07-01

Pellet burners need auxiliary electrical power to provide CO{sub 2} balanced heat in a comfortable and environment friendly way. The idea is to produce this and some extra electricity within the device in order to save resources and to gain operation reliability and independency. An option for micro scale CHP is the usage of thermoelectric generators (TEGs). They allow direct conversion of heat into electrical power. They have the advantage of a long maintenance free durability and noiseless operation without moving parts or any working fluid. The useful heat remains almost unaffected and can still be used for heating. TEGs are predestined for the use in micro scale CHP based on solid biomass. In this paper the first results from the fully integrated prototype are presented. The performance of the TEG was observed for different loads and operating conditions in order to realise an optimised micro scale CHP based on solid biomass. (orig.)

Imaging based agglutination measurement of magnetic micro-particles on a lab-on-a-disk platform

DEFF Research Database (Denmark)

Wantiya, P.; Burger, Robert; Alstrøm, Tommy Sonne

2014-01-01

In this work we present a magnetic micro beads based agglutination assay on a centrifugal microfluidic platform. An imaging based method is used to quantify bead agglutination and measure the concentration of antibodies or C-reactive protein in solution.......In this work we present a magnetic micro beads based agglutination assay on a centrifugal microfluidic platform. An imaging based method is used to quantify bead agglutination and measure the concentration of antibodies or C-reactive protein in solution....

Micro-strip sensors based on CVD diamond

Energy Technology Data Exchange (ETDEWEB)

Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D' Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Meier, D. E-mail: dirk.meier@cern.ch; Mishina, M.; Moroni, L.; Oh, A.; Pan, L.S.; Pernicka, M.; Peitz, A.; Perera, L.; Pirollo, S.; Procario, M.; Riester, J.L.; Roe, S.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Wetstein, M.; White, C.; Zeuner, W.; Zoeller, M

2000-10-11

In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition, we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation.

Micro-strip sensors based on CVD Diamond

CERN Document Server

Adam, W; Bergonzo, P; Bertuccio, G; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; D'Angelo, P; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Hallewell, G D; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Kass, R; Koeth, T W; Krammer, Manfred; Lo Giudice, A; Lü, R; MacLynne, L; Manfredotti, C; Meier, D; Mishina, M; Moroni, L; Oh, A; Pan, L S; Pernicka, Manfred; Peitz, A; Perera, L P; Pirollo, S; Procario, M; Riester, J L; Roe, S; Rousseau, L; Rudge, A; Russ, J; Sala, S; Sampietro, M; Schnetzer, S R; Sciortino, S; Stelzer, H; Stone, R; Suter, B; Tapper, R J; Tesarek, R J; Trischuk, W; Tromson, D; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; Wetstein, M; White, C; Zeuner, W; Zoeller, M M

2000-01-01

In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation.

Micro-strip sensors based on CVD diamond

International Nuclear Information System (INIS)

Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D'Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Meier, D.; Mishina, M.; Moroni, L.; Oh, A.; Pan, L.S.; Pernicka, M.; Peitz, A.; Perera, L.; Pirollo, S.; Procario, M.; Riester, J.L.; Roe, S.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Wetstein, M.; White, C.; Zeuner, W.; Zoeller, M.

2000-01-01

In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition, we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation

Micro-strip sensors based on CVD diamond

Science.gov (United States)

Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D'Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; van Eijk, B.; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K. K.; Gheeraert, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; mac Lynne, L.; Manfredotti, C.; Meier, D.; Mishina, M.; Moroni, L.; Oh, A.; Pan, L. S.; Pernicka, M.; Peitz, A.; Perera, L.; Pirollo, S.; Procario, M.; Riester, J. L.; Roe, S.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R. J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Walsh, A. M.; Wedenig, R.; Weilhammer, P.; Wetstein, M.; White, C.; Zeuner, W.; Zoeller, M.; RD42 Collaboration

2000-10-01

In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition, we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation.

Smartphone-based psychotherapeutic micro-interventions to improve mood in a real-world setting

Directory of Open Access Journals (Sweden)

Gunther Meinlschmidt

2016-07-01

Full Text Available Background: Using mobile communication technology as new personalized approach to treat mental disorders or to more generally improve quality of life is highly promising. Knowledge about intervention components that target key psychopathological processes in terms of transdiagnostic psychotherapy approaches is urgently needed. We explored the use of smartphone-based micro-interventions based on psychotherapeutic techniques, guided by short video-clips, to elicit mood changes.Method: As part of a larger neurofeedback study, all subjects – after being randomly assigned to an experimental or control neurofeedback condition – underwent daily smartphone-based micro-interventions for 13 consecutive days. They were free to choose out of provided techniques, including viscerosensory attention, emotional imagery, facial expression, and contemplative repetition. Changes in mood were assessed in real world using the Multidimensional Mood State Questionnaire (scales: good–bad, GB; awake–tired, AT; and calm–nervous, CN. Results: Twenty-seven men participated on at least eleven days and were thus included in the analyses. Altogether, they underwent 335, generally well-tolerated, micro-intervention sessions, with viscerosensory attention (178 sessions, 53.13% and contemplative repetition (68 sessions, 20.30% being the most frequently applied techniques. Mixed models indicated that subjects showed better mood (GB: b=0.464, 95%confidence interval (CI [0.068, 0.860], t(613.3=2.298, p=0.022 and became more awake (AT: b=0.514, 95%CI [0.103, 0.925], t(612.4=2.456, p=0.014 and calmer (CN: b=0.685, 95%CI [0.360, 1.010], t(612.3=4.137, p<0.001 from pre- to post-micro-intervention. These mood improvements from pre- to post-micro-intervention were associated with changes in mood from the first day until the last day with regard to GB mood (r=0.614, 95%CI [0.297, 0.809], p<0.001, but not AT mood (r=0.279, 95%CI [-0.122, 0.602], p=0.167 and CN mood (r=0.277, 95

Single cell adhesion force measurement for cell viability identification using an AFM cantilever-based micro putter

Science.gov (United States)

Shen, Yajing; Nakajima, Masahiro; Kojima, Seiji; Homma, Michio; Kojima, Masaru; Fukuda, Toshio

2011-11-01

Fast and sensitive cell viability identification is a key point for single cell analysis. To address this issue, this paper reports a novel single cell viability identification method based on the measurement of single cell shear adhesion force using an atomic force microscopy (AFM) cantilever-based micro putter. Viable and nonviable yeast cells are prepared and put onto three kinds of substrate surfaces, i.e. tungsten probe, gold and ITO substrate surfaces. A micro putter is fabricated from the AFM cantilever by focused ion beam etching technique. The spring constant of the micro putter is calibrated using the nanomanipulation approach. The shear adhesion force between the single viable or nonviable cell and each substrate is measured using the micro putter based on the nanorobotic manipulation system inside an environmental scanning electron microscope. The adhesion force is calculated based on the deflection of the micro putter beam. The results show that the adhesion force of the viable cell to the substrate is much larger than that of the nonviable cell. This identification method is label free, fast, sensitive and can give quantitative results at the single cell level.

CFD based aerodynamic modeling to study flight dynamics of a flapping wing micro air vehicle

Science.gov (United States)

Rege, Alok Ashok

The demand for small unmanned air vehicles, commonly termed micro air vehicles or MAV's, is rapidly increasing. Driven by applications ranging from civil search-and-rescue missions to military surveillance missions, there is a rising level of interest and investment in better vehicle designs, and miniaturized components are enabling many rapid advances. The need to better understand fundamental aspects of flight for small vehicles has spawned a surge in high quality research in the area of micro air vehicles. These aircraft have a set of constraints which are, in many ways, considerably different from that of traditional aircraft and are often best addressed by a multidisciplinary approach. Fast-response non-linear controls, nano-structures, integrated propulsion and lift mechanisms, highly flexible structures, and low Reynolds aerodynamics are just a few of the important considerations which may be combined in the execution of MAV research. The main objective of this thesis is to derive a consistent nonlinear dynamic model to study the flight dynamics of micro air vehicles with a reasonably accurate representation of aerodynamic forces and moments. The research is divided into two sections. In the first section, derivation of the nonlinear dynamics of flapping wing micro air vehicles is presented. The flapping wing micro air vehicle (MAV) used in this research is modeled as a system of three rigid bodies: a body and two wings. The design is based on an insect called Drosophila Melanogaster, commonly known as fruit-fly. The mass and inertial effects of the wing on the body are neglected for the present work. The nonlinear dynamics is simulated with the aerodynamic data published in the open literature. The flapping frequency is used as the control input. Simulations are run for different cases of wing positions and the chosen parameters are studied for boundedness. Results show a qualitative inconsistency in boundedness for some cases, and demand a better

Micro-PIXE for the quantitative imaging of chemical elements in single cells

International Nuclear Information System (INIS)

Ortega, R.

2013-01-01

Full text: The knowledge of the intracellular distribution of biological relevant metals is important to understand their mechanisms of action in cells, either for physiological, toxicological or pathological processes. However, the direct detection of trace metals in single cells is a challenging task that requires sophisticated analytical developments. The aim of this seminar will be to present the recent achievements in this field using micro-PIXE analysis. The combination of micro-PIXE with RBS (Rutherford Backscattering Spectrometry) and STIM (Scanning Transmission lon Microscopy) allows the quantitative determination of trace metal content within sub-cellular compartments. The application of STlM analysis will be more specifically highlighted as it provides high spatial resolution imaging (<200 nm) and excellent mass sensitivity (<0.1 ng). Application of the STIM-PIXE-RBS methodology is absolutely needed when organic mass loss appears during PIXE-RBS irradiation. This combination of STIM-PIXE-RBS provides fully quantitative determination of trace element content, expressed in μg/g, which is a quite unique capability for micro-PIXE compared to other micro-analytical methods such as the electron and synchrotron X-ray fluorescence or the techniques based on mass spectrometry. Examples of micro-PIXE studies for subcellular imaging of trace elements in the various fields of interest will be presented such as metal-based toxicology, pharmacology, and neuro degeneration [1] R. Ortega, G. Devés, A. Carmona. J. R. Soc. Interface, 6, (2009) S649-S658. (author)

Analysis of micro-failure behaviors in artificial muscles based on fishing line and sewing thread

Science.gov (United States)

Xu, J. B.; Cheng, K. F.; Tu, S. L.; He, X. M.; Ma, C.; Jin, Y. Z.; Kang, X. N.; Sun, T.; Zhang, Y.

2017-06-01

The aim of the present study was to discuss a new and effective method for testing artificial muscles based on micro-failure behaviors analysis. Thermo-mechanical actuators based on fishing line and sewing thread, also, the capability of responding to ambient temperature variations producing a large amount of shrinkage ratio of a resulting variation in longitudinal length. The minimum micro-failure value is 0.02μm and the maximum value is 1.72μm with nylon twist pattern. The discovery of an innovative effective testing of artificial muscles based on polymeric fibers specimens on micro-failure, rupture, slippage, etc. This research finds out a micro-failure behavior analysis of thermo-mechanical actuators based on fishing line and sewing thread. The specimens show large deformations when heated together with warping performance in terms of shrinkage of energy and densities. With the purpose of providing useful analysis data for the further technology applications, we attempt micrometre-sized artificial muscles which were also tested was readily accessible and also can be applied to other polymeric fibers. Effective use of this technique achievement relies on rotate speed, temperature and tensile direction. The results of the tensile testing experiments were outstanding with respect to some important issues related to the response of micro-structure, twisted polymeric fibers and shrinkage ratio.

Applications of synchrotron-based micro-imaging techniques for the analysis of Cultural Heritage materials

International Nuclear Information System (INIS)

Cotte, Marine; Chilida, Javier; Walter, Philippe; Taniguchi, Yoko; Susini, Jean

2009-01-01

The analysis of cultural Heritage objects is often technically challenging. When analyzing micro-fragments, the amount of matter is usually very tiny, hence requiring sensitive techniques. These samples, in particular painting fragments, may present multi-layered structures, with layer thickness of ∼10 μm. It leads to favor micro-imaging techniques, with a good lateral resolution (about one micrometer), that manage the discriminative study of each layer. Besides, samples are usually very complex in term of chemistry, as they are made of mineral and organic matters, amorphous and crystallized phases, major and minor elements. Accordingly, a multi-modal approach is generally essential to solve the chemical complexity of such hybrid materials. Different examples will be given, to illustrate the various possibilities of synchrotron-based micro-imaging techniques, such as micro X-ray diffraction, micro X-ray fluorescence, micro X-ray absorption spectroscopy and micro FTIR spectroscopy. Focus will be made on paintings, but the whole range of museum objects (going from soft matter like paper or wood to hard matter like metal and glass) will be also considered.

An inexact two-stage stochastic robust programming for residential micro-grid management-based on random demand

International Nuclear Information System (INIS)

Ji, L.; Niu, D.X.; Huang, G.H.

2014-01-01

In this paper a stochastic robust optimization problem of residential micro-grid energy management is presented. Combined cooling, heating and electricity technology (CCHP) is introduced to satisfy various energy demands. Two-stage programming is utilized to find the optimal installed capacity investment and operation control of CCHP (combined cooling heating and power). Moreover, interval programming and robust stochastic optimization methods are exploited to gain interval robust solutions under different robustness levels which are feasible for uncertain data. The obtained results can help micro-grid managers minimizing the investment and operation cost with lower system failure risk when facing fluctuant energy market and uncertain technology parameters. The different robustness levels reflect the risk preference of micro-grid manager. The proposed approach is applied to residential area energy management in North China. Detailed computational results under different robustness level are presented and analyzed for providing investment decision and operation strategies. - Highlights: • An inexact two-stage stochastic robust programming model for CCHP management. • The energy market and technical parameters uncertainties were considered. • Investment decision, operation cost, and system safety were analyzed. • Uncertainties expressed as discrete intervals and probability distributions

Distributed Control in a Network of Households with microCHP

NARCIS (Netherlands)

Larsen, Gunn; Scherpen, Jacquelien M.A.; van Foreest, Nicolaas

2011-01-01

This is an application of a dynamic price mechanism to distributed optimization of a network of houses which are both producers and consumers of electricity. One possibility for domestic generation is the Micro Combined Heat Power system (µCHP). We use a pricing mechanism based on dual

Micro digital sun sensor: system in a package

NARCIS (Netherlands)

Boom, C.W. de; Leijtens, J.A.P.; Duivenbode, L.M.H. van; Heiden, N. van der

2004-01-01

A novel micro Digital Sun Sensor (μDSS) is under development in the frame of a micro systems technology (MST) development program (Microned) from the Dutch Ministry of Economic Affairs. Use of available micro system technologies in combination with the implementation of a dedicated solarcell for

Micro-grid platform based on NODE.JS architecture, implemented in electrical network instrumentation

Science.gov (United States)

Duque, M.; Cando, E.; Aguinaga, A.; Llulluna, F.; Jara, N.; Moreno, T.

2016-05-01

In this document, I propose a theory about the impact of systems based on microgrids in non-industrialized countries that have the goal to improve energy exploitation through alternatives methods of a clean and renewable energy generation and the creation of the app to manage the behavior of the micro-grids based on the NodeJS, Django and IOJS technologies. The micro-grids allow the optimal way to manage energy flow by electric injection directly in electric network small urban's cells in a low cost and available way. In difference from conventional systems, micro-grids can communicate between them to carry energy to places that have higher demand in accurate moments. This system does not require energy storage, so, costs are lower than conventional systems like fuel cells, solar panels or else; even though micro-grids are independent systems, they are not isolated. The impact that this analysis will generate, is the improvement of the electrical network without having greater control than an intelligent network (SMART-GRID); this leads to move to a 20% increase in energy use in a specified network; that suggest there are others sources of energy generation; but for today's needs, we need to standardize methods and remain in place to support all future technologies and the best option are the Smart Grids and Micro-Grids.

A Novel Bearing Lubricating Device Based on the Piezoelectric Micro-Jet

Directory of Open Access Journals (Sweden)

Kai Li

2016-02-01

Full Text Available A novel bearing lubricating device, which is embedded in gyroscope’s bearing system and based on the theory of the piezoelectric micro-jet, was designed for this study. The embedded structure of a bearing lubricating system can make effective use of the limited space of bearing systems without increasing the whole mass of the system. The drop-on-demand (DOD lubrication can be realized by the piezoelectric micro-jet system to implement the long acting lubrication of the bearing system. A mathematical model of inlet boundary conditions was established to carry on the numerical simulation based on CFD. The motion states of the droplets with different voltage excitations were analyzed via numerical simulations, and the injection performances of the piezoelectric micro-jet lubricating device were tested in accordance with past experiments. The influences of different parameters of voltage excitation on injection performance were obtained, and the methods of adjusting the injection performance to meet different requirements are given according to the analyses of the results. The mathematical model and numerical simulation method were confirmed by comparing the results of past simulations and experiments.

Micro-supercapacitors based on interdigital electrodes of reduced graphene oxide and carbon nanotube composites with ultrahigh power handling performance

Energy Technology Data Exchange (ETDEWEB)

Beidaghi, Majid; Wang, Chunlei [Department of Mechanical and Materials Engineering, Florida International University, 10555 W. Flagler St., EC 3463, FL 33174 (United States)

2012-11-07

A novel method for fabricating micro-patterned interdigitated electrodes based on reduced graphene oxide (rGO) and carbon nanotube (CNT) composites for ultra-high power handling micro-supercapacitor application is reported. The binder-free microelectrodes were developed by combining electrostatic spray deposition (ESD) and photolithography lift-off methods. Without typically used thermal or chemical reduction, GO sheets are readily reduced to rGO during the ESD deposition. Electrochemical measurements show that the in-plane interdigital design of the microelectrodes is effective in increasing accessibility of electrolyte ions in-between stacked rGO sheets through an electro-activation process. Addition of CNTs results in reduced restacking of rGO sheets and improved energy and power density. Cyclic voltammetry (CV) measurements show that the specific capacitance of the micro-supercapacitor based on rGO-CNT composites is 6.1 mF cm{sup -2} at 0.01 V s{sup -1}. At a very high scan rate of 50 V s{sup -1}, a specific capacitance of 2.8 mF cm{sup -2} (stack capacitance of 3.1 F cm{sup -3}) is recorded, which is an unprecedented performance for supercapacitors. The addition of CNT, electrolyte-accessible and binder-free microelectrodes, as well as an interdigitated in-plane design result in a high-frequency response of the micro-supercapacitors with resistive-capacitive time constants as low as 4.8 ms. These characteristics suggest that interdigitated rGO-CNT composite electrodes are promising for on-chip energy storage application with high power demands. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A micro-coupling for micro mechanical systems

Science.gov (United States)

Li, Wei; Zhou, Zhixiong; Zhang, Bi; Xiao, Yunya

2016-05-01

The error motions of micro mechanical systems, such as micro-spindles, increase with the increasing of the rotational speed, which not only decreases the rotational accuracy, but also promotes instability and limits the maximum operational speed. One effective way to deal with it is to use micro-flexible couplings between the drive and driven shafts so as to reduce error motions of the driven shaft. But the conventional couplings, such as diaphragm couplings, elastomeric couplings, bellows couplings, and grooved couplings, etc, cannot be directly used because of their large and complicated structures. This study presents a novel micro-coupling that consists of a flexible coupling and a shape memory alloy (SMA)-based clamp for micro mechanical systems. It is monolithic and can be directly machined from a shaft. The study performs design optimization and provides manufacturing considerations, including thermo-mechanical training of the SMA ring for the desired Two-Way-Shape-Memory effect (TWSMe). A prototype micro-coupling and a prototype micro-spindle using the proposed coupling are fabricated and tested. The testing results show that the prototype micro-coupling can bear a torque of above 5 N • mm and an axial force of 8.5 N and be fitted with an SMA ring for clamping action at room temperature (15 °C) and unclamping action below-5 °C. At the same time, the prototype micro-coupling can work at a rotational speed of above 200 kr/min with the application to a high-speed precision micro-spindle. Moreover, the radial runout error of the artifact, as a substitute for the micro-tool, is less than 3 μm while that of turbine shaft is above 7 μm. It can be concluded that the micro-coupling successfully accommodates misalignment errors of the prototype micro-spindle. This research proposes a micro-coupling which is featured with an SMA ring, and it is designed to clamp two shafts, and has smooth transmission, simple assembly, compact structure, zero-maintenance and

JAX: a micro-computer based X-ray diffractometer controller

International Nuclear Information System (INIS)

Naval, P.C. Jr.

1987-05-01

This paper describes a micro-computer based X-ray diffractometer controller and explores its possibilities in simplifying acquisition and analysis of X-ray powder diffraction data. The interrupt-driven controller can operate in both present time and present count data acquisition modes and allows a data analysis program to execute concurrently with data collection. (Auth.). 16 figs.; 2 tabs

Scalable High-Performance Ultraminiature Graphene Micro-Supercapacitors by a Hybrid Technique Combining Direct Writing and Controllable Microdroplet Transfer.

Science.gov (United States)

Shen, Daozhi; Zou, Guisheng; Liu, Lei; Zhao, Wenzheng; Wu, Aiping; Duley, Walter W; Zhou, Y Norman

2018-02-14

Miniaturization of energy storage devices can significantly decrease the overall size of electronic systems. However, this miniaturization is limited by the reduction of electrode dimensions and the reproducible transfer of small electrolyte drops. This paper reports first a simple scalable direct writing method for the production of ultraminiature microsupercapacitor (MSC) electrodes, based on femtosecond laser reduced graphene oxide (fsrGO) interlaced pads. These pads, separated by 2 μm spacing, are 100 μm long and 8 μm wide. A second stage involves the accurate transfer of an electrolyte microdroplet on top of each individual electrode, which can avoid any interference of the electrolyte with other electronic components. Abundant in-plane mesopores in fsrGO induced by a fs laser together with ultrashort interelectrode spacing enables MSCs to exhibit a high specific capacitance (6.3 mF cm -2 and 105 F cm -3 ) and ∼100% retention after 1000 cycles. An all graphene resistor-capacitor (RC) filter is also constructed by combining the MSC and a fsrGO resistor, which is confirmed to exhibit highly enhanced performance characteristics. This new hybrid technique combining fs laser direct writing and precise microdroplet transfer easily enables scalable production of ultraminiature MSCs, which is believed to be significant for practical application of micro-supercapacitor microelectronic systems.

Nanoscale Origins of the Size Effect in the Compression Response of Single Crystal Ni-Base Superalloy Micro-Pillars

Directory of Open Access Journals (Sweden)

Siqi Ying

2018-04-01

Full Text Available Nickel superalloys play a pivotal role in enabling power-generation devices on land, sea, and in the air. They derive their strength from coherent cuboidal precipitates of the ordered γ’ phase that is different from the γ matrix in composition, structure and properties. In order to reveal the correlation between elemental distribution, dislocation glide and the plastic deformation of micro- and nano-sized volumes of a nickel superalloy, a combined in situ nanoindentation compression study was carried out with a scanning electron microscope (SEM on micro- and nano-pillars fabricated by focused ion beam (FIB milling of Ni-base superalloy CMSX4. The observed mechanical response (hardening followed by softening was correlated with the progression of crystal slip that was revealed using FIB nano-tomography and energy-dispersive spectroscopy (EDS elemental mapping. A hypothesis was put forward that the dependence of material strength on the size of the sample (micropillar diameter is correlated with the characteristic dimension of the structural units (γ’ precipitates. By proposing two new dislocation-based models, the results were found to be described well by a new parameter-free Hall–Petch equation.

MicroCar 2003. Abstracts of papers

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

Mechatronics for automotive applications is an important trend, combining mechanics, electronics and information technology. Micro- and nanomechatronics, particularly innovative research disciplines, will help create, in combination with advanced solutions from microsystem technologies, e.g. the electronic packaging, a range of entirely new developments in automobiles. Under the umbrella of the Automotive Suppliers Fair Z2003, it is happening for the very first time now that a momentous scientific conference, such as the MicroCar 2003, brings together representatives from car manufacturers and the electronics industry, as well as a large number of experts from technical colleges, universities and research institutes to discuss the new potentials and possibilities presented by the use of micro and nanomaterials in Leipzig. With the presentation of 50 papers, speakers will inform about their latest research results as well as current trends in micro and nanotechnologies for automotives. This issue is publishing the abstracts of this scientific event.

Lightweight carbon nanotube-based structural-energy storage devices for micro unmanned systems

Science.gov (United States)

Rivera, Monica; Cole, Daniel P.; Hahm, Myung Gwan; Reddy, Arava L. M.; Vajtai, Robert; Ajayan, Pulickel M.; Karna, Shashi P.; Bundy, Mark L.

2012-06-01

There is a strong need for small, lightweight energy storage devices that can satisfy the ever increasing power and energy demands of micro unmanned systems. Currently, most commercial and developmental micro unmanned systems utilize commercial-off-the-shelf (COTS) lithium polymer batteries for their energy storage needs. While COTS lithium polymer batteries are the industry norm, the weight of these batteries can account for up to 60% of the overall system mass and the capacity of these batteries can limit mission durations to the order of only a few minutes. One method to increase vehicle endurance without adding mass or sacrificing payload capabilities is to incorporate multiple system functions into a single material or structure. For example, the body or chassis of a micro vehicle could be replaced with a multifunctional material that would serve as both the vehicle structure and the on-board energy storage device. In this paper we present recent progress towards the development of carbon nanotube (CNT)-based structural-energy storage devices for micro unmanned systems. Randomly oriented and vertically aligned CNT-polymer composite electrodes with varying degrees of flexibility are used as the primary building blocks for lightweight structural-supercapacitors. For the purpose of this study, the mechanical properties of the CNT-based electrodes and the charge-discharge behavior of the supercapacitor devices are examined. Because incorporating multifunctionality into a single component often degrades the properties or performance of individual structures, the performance and property tradeoffs of the CNT-based structural-energy storage devices will also be discussed.

Micro-CTvlab: A web based virtual gallery of biological specimens using X-ray microtomography (micro-CT).

Science.gov (United States)

Keklikoglou, Kleoniki; Faulwetter, Sarah; Chatzinikolaou, Eva; Michalakis, Nikitas; Filiopoulou, Irene; Minadakis, Nikos; Panteri, Emmanouela; Perantinos, George; Gougousis, Alexandros; Arvanitidis, Christos

2016-01-01

During recent years, X-ray microtomography (micro-CT) has seen an increasing use in biological research areas, such as functional morphology, taxonomy, evolutionary biology and developmental research. Micro-CT is a technology which uses X-rays to create sub-micron resolution images of external and internal features of specimens. These images can then be rendered in a three-dimensional space and used for qualitative and quantitative 3D analyses. However, the online exploration and dissemination of micro-CT datasets are rarely made available to the public due to their large size and a lack of dedicated online platforms for the interactive manipulation of 3D data. Here, the development of a virtual micro-CT laboratory (Micro-CT vlab ) is described, which can be used by everyone who is interested in digitisation methods and biological collections and aims at making the micro-CT data exploration of natural history specimens freely available over the internet. The Micro-CT vlab offers to the user virtual image galleries of various taxa which can be displayed and downloaded through a web application. With a few clicks, accurate, detailed and three-dimensional models of species can be studied and virtually dissected without destroying the actual specimen. The data and functions of the Micro-CT vlab can be accessed either on a normal computer or through a dedicated version for mobile devices.

Micro-gen metering solutions

Energy Technology Data Exchange (ETDEWEB)

Elland, J.; Dickson, J.; Cranfield, P.

2003-07-01

This report summarises the results of a project to investigate the regulation of domestic electricity metering work and identify the most economic options for micro-generator installers to undertake work on electricity meters. A micro-generation unit is defined as an energy conversion system converting non-electrical energy into electrical energy and can include technologies such as photovoltaic systems, small-scale wind turbines, micro-hydroelectric systems, and combined heat and power systems. Details of six tasks are given and cover examination of the existing framework and legal documentation for metering work, the existing technical requirements for meter operators, meter operator personnel accreditation, appraisal of options for meter changes and for micro-generation installation, document change procedures, industry consultation, and a review of the costs implications of the options.

A sparsity-based iterative algorithm for reconstruction of micro-CT images from highly undersampled projection datasets obtained with a synchrotron X-ray source

Science.gov (United States)

Melli, S. Ali; Wahid, Khan A.; Babyn, Paul; Cooper, David M. L.; Gopi, Varun P.

2016-12-01

Synchrotron X-ray Micro Computed Tomography (Micro-CT) is an imaging technique which is increasingly used for non-invasive in vivo preclinical imaging. However, it often requires a large number of projections from many different angles to reconstruct high-quality images leading to significantly high radiation doses and long scan times. To utilize this imaging technique further for in vivo imaging, we need to design reconstruction algorithms that reduce the radiation dose and scan time without reduction of reconstructed image quality. This research is focused on using a combination of gradient-based Douglas-Rachford splitting and discrete wavelet packet shrinkage image denoising methods to design an algorithm for reconstruction of large-scale reduced-view synchrotron Micro-CT images with acceptable quality metrics. These quality metrics are computed by comparing the reconstructed images with a high-dose reference image reconstructed from 1800 equally spaced projections spanning 180°. Visual and quantitative-based performance assessment of a synthetic head phantom and a femoral cortical bone sample imaged in the biomedical imaging and therapy bending magnet beamline at the Canadian Light Source demonstrates that the proposed algorithm is superior to the existing reconstruction algorithms. Using the proposed reconstruction algorithm to reduce the number of projections in synchrotron Micro-CT is an effective way to reduce the overall radiation dose and scan time which improves in vivo imaging protocols.

Computerized methodology for micro-CT and histological data inflation using an IVUS based translation map.

Science.gov (United States)

Athanasiou, Lambros S; Rigas, George A; Sakellarios, Antonis I; Exarchos, Themis P; Siogkas, Panagiotis K; Naka, Katerina K; Panetta, Daniele; Pelosi, Gualtiero; Vozzi, Federico; Michalis, Lampros K; Parodi, Oberdan; Fotiadis, Dimitrios I

2015-10-01

A framework for the inflation of micro-CT and histology data using intravascular ultrasound (IVUS) images, is presented. The proposed methodology consists of three steps. In the first step the micro-CT/histological images are manually co-registered with IVUS by experts using fiducial points as landmarks. In the second step the lumen of both the micro-CT/histological images and IVUS images are automatically segmented. Finally, in the third step the micro-CT/histological images are inflated by applying a transformation method on each image. The transformation method is based on the IVUS and micro-CT/histological contour difference. In order to validate the proposed image inflation methodology, plaque areas in the inflated micro-CT and histological images are compared with the ones in the IVUS images. The proposed methodology for inflating micro-CT/histological images increases the sensitivity of plaque area matching between the inflated and the IVUS images (7% and 22% in histological and micro-CT images, respectively). Copyright © 2015 Elsevier Ltd. All rights reserved.

Control of a methanol reformer system using an Adaptive Neuro‐Fuzzy Inference System approach

DEFF Research Database (Denmark)

Justesen, Kristian Kjær; Andersen, John; Ehmsen, Mikkel Præstholm

This work presents a stoichiometry control strategy for a reformed methanol fuel cell system, which uses a reformer to produce hydrogen for an HTPEM fuel cell. One such system is the Serenus H3-350 battery charger developed by the Danish company Serenegy® which this work is based on. The poster...

High-speed micro electrode tool fabrication by a twin-wire EDM system

International Nuclear Information System (INIS)

Sheu, Dong-Yea

2008-01-01

This paper describes a new machining process which combines twin-electro-wire together with two electro discharge circuits to rapidly fabricate micro electrode tools. The results show that transistor electro discharge and RC electro discharge circuits coexist to fabricate micro tools with rough and finish machining both on the same machine. Compared to conventional wire electro discharge grinding (WEDG) technology, a twin-wire EDM system that combines rough and finish machining into one process allows the efficient fabrication of micro tools. This high-speed micro tool fabrication process can be applied not only to micro electrode machining but also to micro punching tool and micro probing tips machining

A dislocation-based crystal viscoplasticity model with application to micro-engineered plasma-facing materials

Energy Technology Data Exchange (ETDEWEB)

Rivera, David; Huang, Yue; Po, Giacomo; Ghoniem, Nasr M., E-mail: ghoniem@ucla.edu

2017-03-15

Materials developed with special surface architecture are shown here to be more resilient to the transient thermomechanical environments imposed by intermittent exposures to high heat flux thermal loading typical of long-pulse plasma transients. In an accompanying article, we present experimental results that show the relaxation of residual thermal stresses in micro-engineered W surfaces. A dislocation-based model is extended here within the framework of large deformation crystal plasticity. The model is applied to the deformation of single crystals, polycrystals, and micro-engineered surfaces composed of a uniform density of micro-pillars. The model is utilized to design tapered surface micro-pillar architecture, composed of a Re core and W coatings. Residual stresses generated by cyclic thermomechanical loading of these architectures show that the surface can be in a compressive stress state, following a short shakedown plasma exposure, thus mitigating surface fracture. - • Materials developed with special surface architecture are shown to be more resilient to the transient thermomechanical plasma transients. • A dislocation-based model is extended within the framework of large deformation crystal plasticity. • The model is applied to the deformation of single crystals, polycrystals, and micro-engineered surfaces. • The model is utilized to design tapered surface micro-pillar architecture, composed of a Re core and W coatings. • Residual stresses generated by cyclic thermomechanical loading show that the surface can be in a compressive stress state, thus mitigating surface fracture.

A dislocation-based crystal viscoplasticity model with application to micro-engineered plasma-facing materials

International Nuclear Information System (INIS)

Rivera, David; Huang, Yue; Po, Giacomo; Ghoniem, Nasr M.

2017-01-01

Materials developed with special surface architecture are shown here to be more resilient to the transient thermomechanical environments imposed by intermittent exposures to high heat flux thermal loading typical of long-pulse plasma transients. In an accompanying article, we present experimental results that show the relaxation of residual thermal stresses in micro-engineered W surfaces. A dislocation-based model is extended here within the framework of large deformation crystal plasticity. The model is applied to the deformation of single crystals, polycrystals, and micro-engineered surfaces composed of a uniform density of micro-pillars. The model is utilized to design tapered surface micro-pillar architecture, composed of a Re core and W coatings. Residual stresses generated by cyclic thermomechanical loading of these architectures show that the surface can be in a compressive stress state, following a short shakedown plasma exposure, thus mitigating surface fracture. - • Materials developed with special surface architecture are shown to be more resilient to the transient thermomechanical plasma transients. • A dislocation-based model is extended within the framework of large deformation crystal plasticity. • The model is applied to the deformation of single crystals, polycrystals, and micro-engineered surfaces. • The model is utilized to design tapered surface micro-pillar architecture, composed of a Re core and W coatings. • Residual stresses generated by cyclic thermomechanical loading show that the surface can be in a compressive stress state, thus mitigating surface fracture.

Fabrication Effects on Polysilicon-based Micro cantilever Piezo resistivity for Biological Sensing Application

International Nuclear Information System (INIS)

Nina Korlina Madzhi; Balkish Natra; Mastura Sidek; Khuan, L.Y.; Anuar Ahmad

2011-01-01

In principle, adsorption of biological molecules on a functionalized surface of a micro fabricated cantilever will cause a surface stress and consequently the cantilever bending. In this work, four different type of polysilicon-based piezo resistive micro cantilever sensors were designed to increase the sensitivity of the micro cantilevers sensor because the forces involved is very small. The design and optimization was performed by using finite element analysis to maximize the relative resistance changes of the piezo resistors as a function of the cantilever vertical displacements. The resistivity of the piezo resistivity micro cantilevers was analyzed before and after dicing process. The maximum resistance changes were systematically investigated by varying the piezo resistor length. The results show that although the thickness of piezo resistor was the same at 0.5 μm the resistance value was varied. (author)

Fiber Temperature Sensor Based on Micro-mechanical Membranes and Optical Interference Structure

International Nuclear Information System (INIS)

Liu Yueming; Tian Weijian; Hua Jing

2011-01-01

A novel fiber temperature sensor is presented theoretically and experimentally in this paper. Its working principle is based on Optical Fabry-Perot interference structure that is formed between a polished optical fiber end and micro-mechanical Bi-layered membranes. When ambient temperature is varying, Bi-layered membranes will be deflected and the length of Fabry-Perot cavity will be changed correspondingly. By detecting the reflecting optical intensity from the Fabry-Perot cavity, the ambient temperature can be measured. Using finite element software ANSYS, the sensor structure was optimized based on optical Interference theory and Bi-layered membranes thermal expansion theory, and theoretical characteristics was simulated by computer software. In the end, using optical fiber 2x2 coupler and photo-electrical detector, the fabricated sample sensor was tested successfully by experiment that demonstrating above theoretical analysis and simulation results. This sensor has some favorable features, such as: micro size owing to its micro-mechanical structure, high sensitivity owing to its working Fabry-Perot interference cavity structure, and optical integration character by using optical fiber techniques.

Silicon-based metallic micro grid for electron field emission

International Nuclear Information System (INIS)

Kim, Jaehong; Jeon, Seok-Gy; Kim, Jung-Il; Kim, Geun-Ju; Heo, Duchang; Shin, Dong Hoon; Sun, Yuning; Lee, Cheol Jin

2012-01-01

A micro-scale metal grid based on a silicon frame for application to electron field emission devices is introduced and experimentally demonstrated. A silicon lattice containing aperture holes with an area of 80 × 80 µm 2 and a thickness of 10 µm is precisely manufactured by dry etching the silicon on one side of a double-polished silicon wafer and by wet etching the opposite side. Because a silicon lattice is more rigid than a pure metal lattice, a thin layer of Au/Ti deposited on the silicon lattice for voltage application can be more resistant to the geometric stress caused by the applied electric field. The micro-fabrication process, the images of the fabricated grid with 88% geometric transparency and the surface profile measurement after thermal feasibility testing up to 700 °C are presented. (paper)

Micro-Doppler Signal Time-Frequency Algorithm Based on STFRFT

Directory of Open Access Journals (Sweden)

Cunsuo Pang

2016-09-01

Full Text Available This paper proposes a time-frequency algorithm based on short-time fractional order Fourier transformation (STFRFT for identification of a complicated movement targets. This algorithm, consisting of a STFRFT order-changing and quick selection method, is effective in reducing the computation load. A multi-order STFRFT time-frequency algorithm is also developed that makes use of the time-frequency feature of each micro-Doppler component signal. This algorithm improves the estimation accuracy of time-frequency curve fitting through multi-order matching. Finally, experiment data were used to demonstrate STFRFT’s performance in micro-Doppler time-frequency analysis. The results validated the higher estimate accuracy of the proposed algorithm. It may be applied to an LFM (Linear frequency modulated pulse radar, SAR (Synthetic aperture radar, or ISAR (Inverse synthetic aperture radar, for improving the probability of target recognition.

Micro-Doppler Signal Time-Frequency Algorithm Based on STFRFT.

Science.gov (United States)

Pang, Cunsuo; Han, Yan; Hou, Huiling; Liu, Shengheng; Zhang, Nan

2016-09-24

This paper proposes a time-frequency algorithm based on short-time fractional order Fourier transformation (STFRFT) for identification of a complicated movement targets. This algorithm, consisting of a STFRFT order-changing and quick selection method, is effective in reducing the computation load. A multi-order STFRFT time-frequency algorithm is also developed that makes use of the time-frequency feature of each micro-Doppler component signal. This algorithm improves the estimation accuracy of time-frequency curve fitting through multi-order matching. Finally, experiment data were used to demonstrate STFRFT's performance in micro-Doppler time-frequency analysis. The results validated the higher estimate accuracy of the proposed algorithm. It may be applied to an LFM (Linear frequency modulated) pulse radar, SAR (Synthetic aperture radar), or ISAR (Inverse synthetic aperture radar), for improving the probability of target recognition.

A classification model for non-alcoholic steatohepatitis (NASH) using confocal Raman micro-spectroscopy

Science.gov (United States)

Yan, Jie; Yu, Yang; Kang, Jeon Woong; Tam, Zhi Yang; Xu, Shuoyu; Fong, Eliza Li Shan; Singh, Surya Pratap; Song, Ziwei; Tucker Kellogg, Lisa; So, Peter; Yu, Hanry

2017-07-01

We combined Raman micro-spectroscopy and machine learning techniques to develop a classification model based on a well-established non-alcoholic steatohepatitis (NASH) mouse model, using spectrum pre-processing, biochemical component analysis (BCA) and logistic regression.

TOPSIS based parametric optimization of laser micro-drilling of TBC coated nickel based superalloy

Science.gov (United States)

Parthiban, K.; Duraiselvam, Muthukannan; Manivannan, R.

2018-06-01

The technique for order of preference by similarity ideal solution (TOPSIS) approach was used for optimizing the process parameters of laser micro-drilling of nickel superalloy C263 with Thermal Barrier Coating (TBC). Plasma spraying was used to deposit the TBC and a pico-second Nd:YAG pulsed laser was used to drill the specimens. Drilling angle, laser scan speed and number of passes were considered as input parameters. Based on the machining conditions, Taguchi L8 orthogonal array was used for conducting the experimental runs. The surface roughness and surface crack density (SCD) were considered as the output measures. The surface roughness was measured using 3D White Light Interferometer (WLI) and the crack density was measured using Scanning Electron Microscope (SEM). The optimized result achieved from this approach suggests reduced surface roughness and surface crack density. The holes drilled at an inclination angle of 45°, laser scan speed of 3 mm/s and 400 number of passes found to be optimum. From the Analysis of variance (ANOVA), inclination angle and number of passes were identified as the major influencing parameter. The optimized parameter combination exhibited a 19% improvement in surface finish and 12% reduction in SCD.

Micro-motion Recognition of Spatial Cone Target Based on ISAR Image Sequences

Directory of Open Access Journals (Sweden)

Changyong Shu

2016-04-01

Full Text Available The accurate micro-motions recognition of spatial cone target is the foundation of the characteristic parameter acquisition. For this reason, a micro-motion recognition method based on the distinguishing characteristics extracted from the Inverse Synthetic Aperture Radar (ISAR sequences is proposed in this paper. The projection trajectory formula of cone node strong scattering source and cone bottom slip-type strong scattering sources, which are located on the spatial cone target, are deduced under three micro-motion types including nutation, precession, and spinning, and the correctness is verified by the electromagnetic simulation. By comparison, differences are found among the projection of the scattering sources with different micro-motions, the coordinate information of the scattering sources in the Inverse Synthetic Aperture Radar sequences is extracted by the CLEAN algorithm, and the spinning is recognized by setting the threshold value of Doppler. The double observation points Interacting Multiple Model Kalman Filter is used to separate the scattering sources projection of the nutation target or precession target, and the cross point number of each scattering source’s projection track is used to classify the nutation or precession. Finally, the electromagnetic simulation data are used to verify the effectiveness of the micro-motion recognition method.

Advanced control of piezoelectric micro-nano-positioning systems

CERN Document Server

Xu, Qingsong

2016-01-01

This book explores emerging methods and algorithms that enable precise control of micro-/nano-positioning systems. The text describes three control strategies: hysteresis-model-based feedforward control and hysteresis-model-free feedback control based on and free from state observation. Each paradigm receives dedicated attention within a particular part of the text. Readers are shown how to design, validate and apply a variety of new control approaches in micromanipulation: hysteresis modelling, discrete-time sliding-mode control and model-reference adaptive control. Experimental results are provided throughout and build up to a detailed treatment of practical applications in the fourth part of the book. The applications focus on control of piezoelectric grippers. Advanced Control of Piezoelectric Micro-/Nano-Positioning Systems will assist academic researchers and practising control and mechatronics engineers interested in suppressing sources of nonlinearity such as hysteresis and drift when combining positi...

Nonlinear behavior of capacitive micro-beams based on strain gradient theory

International Nuclear Information System (INIS)

Fathalilou, Mohammad; Sadeghi, Morteza; Rezazadeh, Ghader

2014-01-01

This paper studies the size dependent behavior of materials in MEMS structures. This behavior becomes noticeable for a structure when the characteristic size such as thickness or diameter is close to its internal length-scale parameter and is insignificant for the high ratio of the characteristic size to the length-scale parameter, which is the case of the silicon base micro-beams. However, in some types of micro-beams like gold or nickel bases, the size dependent effect cannot be overlooked. In such cases, ignoring this behavior in modeling will lead to incorrect results. Some previous researchers have applied classic beam theory on their models and imposed a considerable hypothetical value of residual stress to match their theoretical results with the experimental ones. The equilibrium positions or fixed points of the gold and nickel micro-beams are obtained and shown that for a given DC voltage, there is a considerable difference between the obtained fixed points using classic beam theory, modified couple stress theory, and modified strain gradient theory. In addition, it is shown that the calculated static and dynamic pull-in voltages using higher order theories are much closer to the experimental results and are higher several times than those obtained by classic beam theory.

An electromechanically coupled micro-sphere framework: application to the finite element analysis of electrostrictive polymers

International Nuclear Information System (INIS)

Thylander, Sara; Menzel, Andreas; Ristinmaa, Matti

2012-01-01

The number of industrial applications of electroactive polymers (EAPs) is increasing and, consequently, the need for reliable modelling frameworks for such materials as well as related robust simulation techniques continuously increases. In this context, we combine the modelling of non-linear electroelasticity with a computational micro-sphere formulation in order to simulate the behaviour of EAPs. The micro-sphere approach in general enables the use of physics-based constitutive models like, for instance, the so-called worm-like chain model. By means of the micro-sphere formulation, scalar-valued micromechanical constitutive relations can conveniently be extended to a three-dimensional continuum setting. We discuss several electromechanically coupled numerical examples and make use of the finite element method to solve inhomogeneous boundary value problems. The incorporated material parameters are referred to experimental data for an electrostrictive polymer. The numerical examples show that the coupled micro-sphere formulation combined with the finite element method results in physically sound simulations that mimic the behaviour of an electrostrictive polymer. (paper)

Micro-Expression Recognition Using Color Spaces.

Science.gov (United States)

Wang, Su-Jing; Yan, Wen-Jing; Li, Xiaobai; Zhao, Guoying; Zhou, Chun-Guang; Fu, Xiaolan; Yang, Minghao; Tao, Jianhua

2015-12-01

Micro-expressions are brief involuntary facial expressions that reveal genuine emotions and, thus, help detect lies. Because of their many promising applications, they have attracted the attention of researchers from various fields. Recent research reveals that two perceptual color spaces (CIELab and CIELuv) provide useful information for expression recognition. This paper is an extended version of our International Conference on Pattern Recognition paper, in which we propose a novel color space model, tensor independent color space (TICS), to help recognize micro-expressions. In this paper, we further show that CIELab and CIELuv are also helpful in recognizing micro-expressions, and we indicate why these three color spaces achieve better performance. A micro-expression color video clip is treated as a fourth-order tensor, i.e., a four-dimension array. The first two dimensions are the spatial information, the third is the temporal information, and the fourth is the color information. We transform the fourth dimension from RGB into TICS, in which the color components are as independent as possible. The combination of dynamic texture and independent color components achieves a higher accuracy than does that of RGB. In addition, we define a set of regions of interests (ROIs) based on the facial action coding system and calculated the dynamic texture histograms for each ROI. Experiments are conducted on two micro-expression databases, CASME and CASME 2, and the results show that the performances for TICS, CIELab, and CIELuv are better than those for RGB or gray.

Atomic force microscope with combined FTIR-Raman spectroscopy having a micro thermal analyzer

Science.gov (United States)

Fink, Samuel D [Aiken, SC; Fondeur, Fernando F [North Augusta, SC

2011-10-18

An atomic force microscope is provided that includes a micro thermal analyzer with a tip. The micro thermal analyzer is configured for obtaining topographical data from a sample. A raman spectrometer is included and is configured for use in obtaining chemical data from the sample.

NAViGaTing the micronome--using multiple microRNA prediction databases to identify signalling pathway-associated microRNAs.

Directory of Open Access Journals (Sweden)

Elize A Shirdel

2011-02-01

Full Text Available MicroRNAs are a class of small RNAs known to regulate gene expression at the transcript level, the protein level, or both. Since microRNA binding is sequence-based but possibly structure-specific, work in this area has resulted in multiple databases storing predicted microRNA:target relationships computed using diverse algorithms. We integrate prediction databases, compare predictions to in vitro data, and use cross-database predictions to model the microRNA:transcript interactome--referred to as the micronome--to study microRNA involvement in well-known signalling pathways as well as associations with disease. We make this data freely available with a flexible user interface as our microRNA Data Integration Portal--mirDIP (http://ophid.utoronto.ca/mirDIP.mirDIP integrates prediction databases to elucidate accurate microRNA:target relationships. Using NAViGaTOR to produce interaction networks implicating microRNAs in literature-based, KEGG-based and Reactome-based pathways, we find these signalling pathway networks have significantly more microRNA involvement compared to chance (p<0.05, suggesting microRNAs co-target many genes in a given pathway. Further examination of the micronome shows two distinct classes of microRNAs; universe microRNAs, which are involved in many signalling pathways; and intra-pathway microRNAs, which target multiple genes within one signalling pathway. We find universe microRNAs to have more targets (p<0.0001, to be more studied (p<0.0002, and to have higher degree in the KEGG cancer pathway (p<0.0001, compared to intra-pathway microRNAs.Our pathway-based analysis of mirDIP data suggests microRNAs are involved in intra-pathway signalling. We identify two distinct classes of microRNAs, suggesting a hierarchical organization of microRNAs co-targeting genes both within and between pathways, and implying differential involvement of universe and intra-pathway microRNAs at the disease level.

Ontology-based, Tissue MicroArray oriented, image centered tissue bank

Directory of Open Access Journals (Sweden)

Viti Federica

2008-04-01

Full Text Available Abstract Background Tissue MicroArray technique is becoming increasingly important in pathology for the validation of experimental data from transcriptomic analysis. This approach produces many images which need to be properly managed, if possible with an infrastructure able to support tissue sharing between institutes. Moreover, the available frameworks oriented to Tissue MicroArray provide good storage for clinical patient, sample treatment and block construction information, but their utility is limited by the lack of data integration with biomolecular information. Results In this work we propose a Tissue MicroArray web oriented system to support researchers in managing bio-samples and, through the use of ontologies, enables tissue sharing aimed at the design of Tissue MicroArray experiments and results evaluation. Indeed, our system provides ontological description both for pre-analysis tissue images and for post-process analysis image results, which is crucial for information exchange. Moreover, working on well-defined terms it is then possible to query web resources for literature articles to integrate both pathology and bioinformatics data. Conclusions Using this system, users associate an ontology-based description to each image uploaded into the database and also integrate results with the ontological description of biosequences identified in every tissue. Moreover, it is possible to integrate the ontological description provided by the user with a full compliant gene ontology definition, enabling statistical studies about correlation between the analyzed pathology and the most commonly related biological processes.

Non-destructive evaluation of teeth restored with different composite resins using synchrotron based micro-imaging.

Science.gov (United States)

Fatima, A; Kulkarni, V K; Banda, N R; Agrawal, A K; Singh, B; Sarkar, P S; Tripathi, S; Shripathi, T; Kashyap, Y; Sinha, A

2016-01-01

Application of high resolution synchrotron micro-imaging in microdefects studies of restored dental samples. The purpose of this study was to identify and compare the defects in restorations done by two different resin systems on teeth samples using synchrotron based micro-imaging techniques namely Phase Contrast Imaging (PCI) and micro-computed tomography (MCT). With this aim acquired image quality was also compared with routinely used RVG (Radiovisiograph). Crowns of human teeth samples were fractured mechanically involving only enamel and dentin, without exposure of pulp chamber and were divided into two groups depending on the restorative composite materials used. Group A samples were restored using a submicron Hybrid composite material and Group B samples were restored using a Nano-Hybrid restorative composite material. Synchrotron based PCI and MCT was performed with the aim of visualization of tooth structure, composite resin and their interface. The quantitative and qualitative comparison of phase contrast and absorption contrast images along with MCT on the restored teeth samples shows comparatively large number of voids in Group A samples. Quality assessment of dental restorations using synchrotron based micro-imaging suggests Nano-Hybrid resin restorations (Group B) are better than Group A.

Optimal micro-mirror tilt angle and sync mark design for digital micro-mirror device based collinear holographic data storage system.

Science.gov (United States)

Liu, Jinpeng; Horimai, Hideyoshi; Lin, Xiao; Liu, Jinyan; Huang, Yong; Tan, Xiaodi

2017-06-01

The collinear holographic data storage system (CHDSS) is a very promising storage system due to its large storage capacities and high transfer rates in the era of big data. The digital micro-mirror device (DMD) as a spatial light modulator is the key device of the CHDSS due to its high speed, high precision, and broadband working range. To improve the system stability and performance, an optimal micro-mirror tilt angle was theoretically calculated and experimentally confirmed by analyzing the relationship between the tilt angle of the micro-mirror on the DMD and the power profiles of diffraction patterns of the DMD at the Fourier plane. In addition, we proposed a novel chess board sync mark design in the data page to reduce the system bit error rate in circumstances of reduced aperture required to decrease noise and median exposure amount. It will provide practical guidance for future DMD based CHDSS development.

Integration of Fuel Cell Micro-CHPs on Low. Voltage Grid: A Danish Case Study

DEFF Research Database (Denmark)

You, Shi; Marra, Francesco; Træholt, Chresten

2012-01-01

The future significance of fuel cell (FC) powered micro combined heat and power (micro-CHP) units in meeting the residential energy demands is set to increase, which may have a considerable impact on the low voltage (LV) grid. The objective of this paper is to investigate into the related technical...... issues using a Danish case study with different penetration levels of uncoordinated FC micro-CHPs. Based on the findings, it is recommended to design grid oriented integration strategies such as Virtual Power Plants (VPPs) for achieving future smart grids with a large roll out of distributed energy...

Note: A resonating reflector-based optical system for motion measurement in micro-cantilever arrays

International Nuclear Information System (INIS)

Sathishkumar, P.; Punyabrahma, P.; Sri Muthu Mrinalini, R.; Jayanth, G. R.

2015-01-01

A robust, compact optical measurement unit for motion measurement in micro-cantilever arrays enables development of portable micro-cantilever sensors. This paper reports on an optical beam deflection-based system to measure the deflection of micro-cantilevers in an array that employs a single laser source, a single detector, and a resonating reflector to scan the measurement laser across the array. A strategy is also proposed to extract the deflection of individual cantilevers from the acquired data. The proposed system and measurement strategy are experimentally evaluated and demonstrated to measure motion of multiple cantilevers in an array

Micro- and nano bio-based delivery systems for food applications: In vitro behavior.

Science.gov (United States)

de Souza Simões, Lívia; Madalena, Daniel A; Pinheiro, Ana C; Teixeira, José A; Vicente, António A; Ramos, Óscar L

2017-05-01

Micro- and nanoencapsulation is an emerging technology in the food field that potentially allows the improvement of food quality and human health. Bio-based delivery systems of bioactive compounds have a wide variety of morphologies that influence their stability and functional performance. The incorporation of bioactive compounds in food products using micro- and nano-delivery systems may offer extra health benefits, beyond basic nutrition, once their encapsulation may provide protection against undesired environmental conditions (e.g., heat, light and oxygen) along the food chain (including processing and storage), thus improving their bioavailability, while enabling their controlled release and target delivery. This review provides an overview of the bio-based materials currently used for encapsulation of bioactive compounds intended for food applications, as well as the main production techniques employed in the development of micro- and nanosystems. The behavior of such systems and of bioactive compounds entrapped into, throughout in vitro gastrointestinal systems, is also tracked in a critical manner. Comparisons between various in vitro digestion systems (including the main advantages and disadvantages) currently in use, as well as correlations between the behavior of micro- and nanosystems studied through in vitro and in vivo systems were highlighted and discussed here for the first time. Finally, examples of bioactive micro- and nanosystems added to food simulants or to real food matrices are provided, together with a revision of the main challenges for their safe commercialization, the regulatory issues involved and the main legislation aspects. Copyright © 2017 Elsevier B.V. All rights reserved.

Piezoelectric actuated micro-resonators based on the growth of diamond on aluminum nitride thin films

International Nuclear Information System (INIS)

Hees, J; Heidrich, N; Pletschen, W; Sah, R E; Wolfer, M; Lebedev, V; Nebel, C E; Ambacher, O; Williams, O A

2013-01-01

Unimorph heterostructures based on piezoelectric aluminum nitride (AlN) and diamond thin films are highly desirable for applications in micro- and nanoelectromechanical systems. In this paper, we present a new approach to combine thin conductive boron-doped as well as insulating nanocrystalline diamond (NCD) with sputtered AlN films without the need for any buffer layers between AlN and NCD or polishing steps. The zeta potentials of differently treated nanodiamond (ND) particles in aqueous colloids are adjusted to the zeta potential of AlN in water. Thereby, the nucleation density for the initial growth of diamond on AlN can be varied from very low (10 8 cm −2 ), in the case of hydrogen-treated ND seeding particles, to very high values of 10 11 cm −2 for oxidized ND particles. Our approach yielding high nucleation densities allows the growth of very thin NCD films on AlN with thicknesses as low as 40 nm for applications such as microelectromechanical beam resonators. Fabricated piezo-actuated micro-resonators exhibit enhanced mechanical properties due to the incorporation of boron-doped NCD films. Highly boron-doped NCD thin films which replace the metal top electrode offer Young’s moduli of more than 1000 GPa. (paper)

Thermal performance of a micro-combustor for micro-gas turbine system

International Nuclear Information System (INIS)

Cao, H.L.; Xu, J.L.

2007-01-01

Premixed combustion of hydrogen gas and air was performed in a stainless steel based micro-annular combustor for a micro-gas turbine system. Micro-scale combustion has proved to be stable in the micro-combustor with a gap of 2 mm. The operating range of the micro-combustor was measured, and the maximum excess air ratio is up to 4.5. The distribution of the outer wall temperature and the temperature of exhaust gas of the micro-combustor with excess air ratio were obtained, and the wall temperature of the micro-combustor reaches its maximum value at the excess air ratio of 0.9 instead of 1 (stoichiometric ratio). The heat loss of the micro-combustor to the environment was calculated and even exceeds 70% of the total thermal power computed from the consumed hydrogen mass flow rate. Moreover, radiant heat transfer covers a large fraction of the total heat loss. Measures used to reduce the heat loss were proposed to improve the thermal performance of the micro-combustor. The optimal operating status of the micro-combustor and micro-gas turbine is analyzed and proposed by analyzing the relationship of the temperature of the exhaust gas of the micro-combustor with thermal power and excess air ratio. The investigation of the thermal performance of the micro-combustor is helpful to design an improved micro-combustor

Servo scanning 3D micro EDM for array micro cavities using on-machine fabricated tool electrodes

Science.gov (United States)

Tong, Hao; Li, Yong; Zhang, Long

2018-02-01

Array micro cavities are useful in many fields including in micro molds, optical devices, biochips and so on. Array servo scanning micro electro discharge machining (EDM), using array micro electrodes with simple cross-sectional shape, has the advantage of machining complex 3D micro cavities in batches. In this paper, the machining errors caused by offline-fabricated array micro electrodes are analyzed in particular, and then a machining process of array servo scanning micro EDM is proposed by using on-machine fabricated array micro electrodes. The array micro electrodes are fabricated on-machine by combined procedures including wire electro discharge grinding, array reverse copying and electrode end trimming. Nine-array tool electrodes with Φ80 µm diameter and 600 µm length are obtained. Furthermore, the proposed process is verified by several machining experiments for achieving nine-array hexagonal micro cavities with top side length of 300 µm, bottom side length of 150 µm, and depth of 112 µm or 120 µm. In the experiments, a chip hump accumulates on the electrode tips like the built-up edge in mechanical machining under the conditions of brass workpieces, copper electrodes and the dielectric of deionized water. The accumulated hump can be avoided by replacing the water dielectric by an oil dielectric.

Characterization of micro-resonator based on enhanced metal insulator semiconductor capacitor for glucose recognition.

Science.gov (United States)

Dhakal, Rajendra; Kim, E S; Jo, Yong-Hwa; Kim, Sung-Soo; Kim, Nam-Young

2017-03-01

We present a concept for the characterization of micro-fabricated based resonator incorporating air-bridge metal-insulator-semiconductor (MIS) capacitor to continuously monitor an individual's state of glucose levels based on frequency variation. The investigation revealed that, the micro-resonator based on MIS capacitor holds considerable promise for implementation and recognition as a glucose sensor for human serum. The discrepancy in complex permittivity as a result of enhanced capacitor was achieved for the detection and determination of random glucose concentration levels using a unique variation of capacitor that indeed results in an adequate variation of the resonance frequency. Moreover, the design and development of micro-resonator with enhanced MIS capacitor generate a resolution of 112.38 × 10 -3 pF/mg/dl, minimum detectable glucose level of 7.45mg/dl, and a limit of quantification of 22.58mg/dl. Additionally, this unique approach offers long-term reliability for mediator-free glucose sensing with a relative standard deviation of less than 0.5%. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

A micro-structured Si-based electrodes for high capacity electrical double layer capacitors

International Nuclear Information System (INIS)

Krikscikas, Valdas; Oguchi, Hiroyuki; Hara, Motoaki; Kuwano, Hiroki; Yanazawa, Hiroshi

2014-01-01

We challenged to make basis for Si electrodes of electric double layer capacitors (EDLC) used as a power source of micro-sensor nodes. Mcroelectromechanical systems (MEMS) processes were successfully introduced to fabricate micro-structured Si-based electrodes to obtain high surface area which leads to high capacity of EDLCs. Study of fundamental properties revealed that the microstructured electrodes benefit from good wettability to electrolytes, but suffer from electric resistance. We found that this problem can be solved by metal-coating of the electrode surface. Finally we build an EDLC consisting of Au-coated micro-structured Si electrodes. This EDLC showed capacity of 14.3 mF/cm 2 , which is about 530 times larger than that of an EDLC consisting of flat Au electrodes

Combining optical trapping in a microfluidic channel with simultaneous micro-Raman spectroscopy and motion detection

Science.gov (United States)

Lawton, Penelope F.; Saunter, Christopher D.; Girkin, John M.

2014-03-01

Since their invention by Ashkin optical tweezers have demonstrated their ability and versatility as a non-invasive tool for micromanipulation. One of the most useful additions to the basic optical tweezers system is micro-Raman spectroscopy, which permits highly sensitive analysis of single cells or particles. We report on the development of a dual laser system combining two spatial light modulators to holographically manipulate multiple traps (at 1064nm) whilst undertaking Raman spectroscopy using a 532nm laser. We can thus simultaneously trap multiple particles and record their Raman spectra, without perturbing the trapping system. The dual beam system is built around micro-fluidic channels where crystallisation of calcium carbonate occurs on polymethylmethacrylate (PMMA) beads. The setup is designed to simulate at a microscopic level the reactions that occur on items in a dishwasher, where permanent filming of calcium carbonate on drinking glasses is a problem. Our system allows us to monitor crystal growth on trapped particles in which the Raman spectrum and changes in movement of the bead are recorded. Due to the expected low level of crystallisation on the bead surfaces this allows us to obtain results quickly and with high sensitivity. The long term goal is to study the development of filming on samples in-situ with the microfl.uidic system acting as a model dishwasher.

Nano-in-Micro Self-Reporting Hydrogel Constructs.

Science.gov (United States)

Tirella, Annalisa; La Marca, Margherita; Brace, Leigh-Anne; Mattei, Giorgio; Aylott, Jonathan W; Ahluwalia, Arti

2015-08-01

Highly reproducible Nano-in-Micro constructs are fabricated to provide a well-defined and self-reporting biomimetic environment for hepatocytes. Based on a protein/hydrogel formulation with controlled shape, size and composition, the constructs enable efficient nutrient exchange and provide an adhesive 3D framework to cells. Co-encapsulation of hepatocytes and ratiometric optical nanosensors with pH sensitivity in the physiological range allows continuous monitoring of the microenvironment. The lobule-sized microbeads are fabricated using an automated droplet generator, Sphyga (Spherical Hydrogel Generator) combining alginate, collagen, decellularized hepatic tissue, pH-nanosensors and hepatocytes. The pH inside the Nano-in-Micro constructs is monitored during culture, while assaying media for hepatic function and vitality markers. Although the local pH changes by several units during bead fabrication, when encapsulated cells are most likely to undergo stress, it is stable and buffered by cell culture media thereafter. Albumin secretion and urea production are significantly higher in the microbeads compared with controls, indicating that the encapsulated Nano-in-Micro environment is conducive to enhanced hepatic function.

A Study of a Diesel Engine Based Micro-CHP System

Energy Technology Data Exchange (ETDEWEB)

Krishna, C.R.; Andrews, J.; Tutu, N.; Butcher, T.

2010-08-31

This project, funded by New York State Energy Research and Development Agency (NYSERDA), investigated the potential for an oil-fired combined heat and power system (micro-CHP system) for potential use in residences that use oil to heat their homes. Obviously, this requires the power source to be one that uses heating oil (diesel). The work consisted of an experimental study using a diesel engine and an analytical study that examined potential energy savings and benefits of micro-CHP systems for 'typical' locations in New York State. A search for a small diesel engine disclosed that no such engines were manufactured in the U.S. A single cylinder engine manufactured in Germany driving an electric generator was purchased for the experimental work. The engine was tested using on-road diesel fuel (15 ppm sulfur), and biodiesel blends. One of the main objectives was to demonstrate the possibility of operation in the so-called HCCI (Homogeneous Charge Compression Ignition) mode. The HCCI mode of operation of engines is being explored as a way to reduce the emission of smoke, and NOx significantly without exhaust treatment. This is being done primarily in the context of engines used in transportation applications. However, it is felt that in a micro-CHP application using a single cylinder engine, such an approach would confer those emission benefits and would be much easier to implement. This was demonstrated successfully by injecting the fuel into the engine air intake using a heated atomizer made by Econox Technologies LLC to promote significant vaporization before entering the cylinder. Efficiency and emission measurements were made under different electrical loads provided by two space heaters connected to the generator in normal and HCCI modes of operation. The goals of the analytical work were to characterize, from the published literature, the prime-movers for micro-CHP applications, quantify parametrically the expected energy savings of using micro

Embodied energy analysis of photovoltaic (PV) system based on macro- and micro-level

International Nuclear Information System (INIS)

Nawaz, I.; Tiwari, G.N.

2006-01-01

In this paper the energy payback time and CO 2 emissions of photovoltaic (PV) system have been analyzed. The embodied energy for production of PV module based on single crystal silicon, as well as for the manufacturing of other system components have been computed at macro- and micro-level assuming irradiation of 800-1200 W/m 2 in different climatic zones in India for inclined surface. The energy payback time with and without balance-of-system for open field and rooftop has been evaluated. It is found that the embodied energy at micro-level is significantly higher than embodied energy at macro-level. The effect of insolation, overall efficiency, lifetime of PV system on energy pay back time and CO 2 emissions have been studied with and without balance of system. A 1.2 kW p PV system of SIEMENS for mudhouse at IIT, Delhi based on macro- and micro-level has been evaluated. The CO 2 mitigation potential, the importance and role of PV system for sustainable development are also highlighted

Determination of elemental abundances in impact materials by micro-PIXE and micro-SRXRF methods

International Nuclear Information System (INIS)

Uzonyi, I.; Szabo, Gy.; Kiss, A.Z.; Szoeoer, Gy.; Rozsa, P.

2004-01-01

The most famous and well-preserved meteorite crater in the world is the Barringer Meteor Crater (Arizona, USA). The meteorite is supposed to be a fragment of a small asteroid of our solar system. During the impact event the matter of the projectile mixed with that of the target rocks forming breccias, slag and spherules. For the non-destructive characterization of the impact materials a combined micro-PIXE and micro-SRXRF technique was applied. (N.T.)

All-solid-state micro-supercapacitors based on inkjet printed graphene electrodes

Science.gov (United States)

Li, Jiantong; Mishukova, Viktoriia; Östling, Mikael

2016-09-01

The all-solid-state graphene-based in-plane micro-supercapacitors are fabricated simply through reliable inkjet printing of pristine graphene in interdigitated structure on silicon wafers to serve as both electrodes and current collectors, and a following drop casting of polymer electrolytes (polyvinyl alcohol/H3PO4). Benefiting from the printing processing, an attractive porous electrode microstructure with a large number of vertically orientated graphene flakes is observed. The devices exhibit commendable areal capacitance over 0.1 mF/cm2 and a long cycle life of over 1000 times. The simple and scalable fabrication technique for efficient micro-supercapacitors is promising for on-chip energy storage applications in emerging electronics.

Controlled delivery of acyclovir from porous silicon micro- and nanoparticles

Science.gov (United States)

Maniya, Nalin H.; Patel, Sanjaykumar R.; Murthy, Z. V. P.

2015-03-01

In this work, micro- and nanoparticles of porous silicon (PSi) are demonstrated to act as effective carrier for the controlled delivery of acyclovir (ACV). PSi films prepared by electrochemical etching were fractured by ultrasonication to prepare micro- and nanoparticles. PSi native particles were thermally oxidized (TOPSi) and thermally hydrosilylated using undecylenic acid (UnPSi). PSi particles with three different surface chemistries were then loaded with ACV by physical adsorption and covalent attachment. Such particles were characterized by scanning electron microscopy, dynamic light scattering, and Fourier transform infrared spectroscopy. In vitro ACV release experiments in phosphate buffered saline showed sustained release behaviour from both micro- and nanoparticles and order of release was found to be native PSi > TOPSi > UnPSi. Drug release kinetics study using Korsmeyer-Peppas model suggested a combination of both drug diffusion and Si scaffold erosion based drug release mechanisms.

High Performance Transfer Press for Precision Manufacturing of Micro Metal Parts

DEFF Research Database (Denmark)

Mahshid, Rasoul

for this technology and are available already in the market. Similar to conventional forming processes, the presence of a handling system can significantly improve the efficiency of the technology towards building a high performance transfer press for micro forming technology. To examine this possibility...... for actuation principle and mechanical grippers based on self-centering and friction principles. This study introduced a methodology for the analysis and characterization of this transfer system on component level and system level. Laser interferometry was used in combination with analytical models to predict...... the positioning ability of the actuator in a static as well as dynamic mode. In combination with an analysis of the grippers, a full description of the transfer precision inside the forming press was obtained. The current research involved integration of a handling system into an existing developed micro press...

Thermodynamic Performance Study of Biomass Gasification, Solid Oxide Fuel Cell and Micro Gas Turbine Hybrid Systems

DEFF Research Database (Denmark)

Bang-Møller, Christian; Rokni, Masoud

2010-01-01

A system level modelling study of three combined heat and power systems based on biomass gasification is presented. Product gas is converted in a micro gas turbine (MGT) in the first system, in a solid oxide fuel cell (SOFC) in the second system and in a combined SOFC–MGT arrangement in the third...

A low power flash-FPGA based brain implant micro-system of PID control.

Science.gov (United States)

Lijuan Xia; Fattah, Nabeel; Soltan, Ahmed; Jackson, Andrew; Chester, Graeme; Degenaar, Patrick

2017-07-01

In this paper, we demonstrate that a low power flash FPGA based micro-system can provide a low power programmable interface for closed-loop brain implant inter- faces. The proposed micro-system receives recording local field potential (LFP) signals from an implanted probe, performs closed-loop control using a first order control system, then converts the signal into an optogenetic control stimulus pattern. Stimulus can be implemented through optoelectronic probes. The long term target is for both fundamental neuroscience applications and for clinical use in treating epilepsy. Utilizing our device, closed-loop processing consumes only 14nJ of power per PID cycle compared to 1.52μJ per cycle for a micro-controller implementation. Compared to an application specific digital integrated circuit, flash FPGA's are inherently programmable.

Micro-PIXE for single cell analysis

International Nuclear Information System (INIS)

Ortega, Richard

2012-01-01

The knowledge of the intracellular distribution of biological relevant metals is important to understand their mechanisms of action in cells, either for physiological, toxicological or pathological processes. However, the direct detection of trace metals in single cells is a challenging task that requires sophisticated analytical developments. The combination of micro-PIXE with RBS and STIM (Scanning Transmission Ion Microscopy) allows the quantitative determination of trace metal content within sub-cellular compartments. The application of STIM analysis provides high spatial resolution imaging (< 200 nm) and excellent mass sensitivity (< 0.1 ng). Application of the STIM-PIXE-RBS methodology is absolutely needed when organic mass loss appears during PIXE-RBS irradiation. This combination of STIM-PIXE-RBS provides fully quantitative determination of trace element content, expressed in μg/g, which is a quite unique capability for micro-PIXE compared to other micro-analytical methods such as the electron and synchrotron x-ray fluorescence. Examples of micro-PIXE studies for sub-cellular imaging of trace elements in various fields of interest will be presented: in patho-physiology of trace elements involved in neurodegenerative diseases such as Parkinson's disease, and in toxicology of metals such as cobalt. (author)

Micro Cooling, Heating, and Power (Micro-CHP) and Bio-Fuel Center, Mississippi State University

Energy Technology Data Exchange (ETDEWEB)

Louay Chamra

2008-09-26

Initially, most micro-CHP systems will likely be designed as constant-power output or base-load systems. This implies that at some point the power requirement will not be met, or that the requirement will be exceeded. Realistically, both cases will occur within a 24-hour period. For example, in the United States, the base electrical load for the average home is approximately 2 kW while the peak electrical demand is slightly over 4 kW. If a 3 kWe micro- CHP system were installed in this situation, part of the time more energy will be provided than could be used and for a portion of the time more energy will be required than could be provided. Jalalzadeh-Azar [6] investigated this situation and presented a comparison of electrical- and thermal-load-following CHP systems. In his investigation he included in a parametric analysis addressing the influence of the subsystem efficiencies on the total primary energy consumption as well as an economic analysis of these systems. He found that an increase in the efficiencies of the on-site power generation and electrical equipment reduced the total monthly import of electricity. A methodology for calculating performance characteristics of different micro-CHP system components will be introduced in this article. Thermodynamic cycles are used to model each individual prime mover. The prime movers modeled in this article are a spark-ignition internal combustion engine (Otto cycle) and a diesel engine (Diesel cycle). Calculations for heat exchanger, absorption chiller, and boiler modeling are also presented. The individual component models are then linked together to calculate total system performance values. Performance characteristics that will be observed for each system include maximum fuel flow rate, total monthly fuel consumption, and system energy (electrical, thermal, and total) efficiencies. Also, whether or not both the required electrical and thermal loads can sufficiently be accounted for within the system

Study on the Road Traffic Survey System Based on Micro-ferromagnetic Induction Coil Sensor

Directory of Open Access Journals (Sweden)

Liang Tong

2014-05-01

Full Text Available Road traffic information is the basis of road traffic management and control. Due to the special design of the sensor coil and ferromagnetic core, traffic survey system which uses micro ferromagnetic inductive coil vehicle detector, not only has the features of small size, simple installation and little road surface damage, but also has the advantages of output signal strength, simple signal processing circuit and obvious characteristics for output waveform corresponding vehicle feature. Based on the introduction of the sensor working principle, the construction of hardware and signal processing circuit for the traffic survey system is described in detail in the paper. Combined with the characteristics of the sensor output waveform, adaptive nearest neighbor clustering RBF neural network algorithm used to classify the vehicles is proposed and verified by experimental method. The result has a high vehicle classification rate and demonstrates the feasibility of the system.

Nondestructive web thickness measurement of micro-drills with an integrated laser inspection system

Science.gov (United States)

Chuang, Shui-Fa; Chen, Yen-Chung; Chang, Wen-Tung; Lin, Ching-Chih; Tarng, Yeong-Shin

2010-09-01

Nowadays, the electric and semiconductor industries use numerous micro-drills to machine micro-holes in printed circuit boards. The measurement of web thickness of micro-drills, a key parameter of micro-drill geometry influencing drill rigidity and chip-removal ability, is quite important to ensure quality control. Traditionally, inefficiently destructive measuring method is adopted by inspectors. To improve quality and efficiency of the web thickness measuring tasks, a nondestructive measuring method is required. In this paper, based on the laser micro-gauge (LMG) and laser confocal displacement meter (LCDM) techniques, a nondestructive measuring principle of web thickness of micro-drills is introduced. An integrated laser inspection system, mainly consisting of a LMG, a LCDM and a two-axis-driven micro-drill fixture device, was developed. Experiments meant to inspect web thickness of micro-drill samples with a nominal diameter of 0.25 mm were conducted to test the feasibility of the developed laser inspection system. The experimental results showed that the web thickness measurement could achieve an estimated repeatability of ± 1.6 μm and a worst repeatability of ± 7.5 μm. The developed laser inspection system, combined with the nondestructive measuring principle, was able to undertake the web thickness measuring tasks for certain micro-drills.

Towards an inline reconstruction architecture for micro-CT systems

International Nuclear Information System (INIS)

Brasse, David; Humbert, Bernard; Mathelin, Carole; Rio, Marie-Christine; Guyonnet, Jean-Louis

2005-01-01

Recent developments in micro-CT have revolutionized the ability to examine in vivo living experimental animal models such as mouse with a spatial resolution less than 50 μm. The main requirements of in vivo imaging for biological researchers are a good spatial resolution, a low dose induced to the animal during the full examination and a reduced acquisition and reconstruction time for screening purposes. We introduce inline acquisition and reconstruction architecture to obtain in real time the 3D attenuation map of the animal fulfilling the three previous requirements. The micro-CT system is based on commercially available x-ray detector and micro-focus x-ray source. The reconstruction architecture is based on a cluster of PCs where a dedicated communication scheme combining serial and parallel treatments is implemented. In order to obtain high performance transmission rate between the detector and the reconstruction architecture, a dedicated data acquisition system is also developed. With the proposed solution, the time required to filter and backproject a projection of 2048 x 2048 pixels inside a volume of 140 mega voxels using the Feldkamp algorithm is similar to 500 ms, the time needed to acquire the same projection

Combined effects of gamma irradiation and cadmium on cellular and population-level endpoints of the micro-alga Pseudokirchneriella subcapitata

Energy Technology Data Exchange (ETDEWEB)

Bradshaw, C. [Stockholm University (Sweden); Abdul Meseh, D.; Alasawi, H.; Qiang, M.; Nascimento, F. [Dept of Ecology, Environment and Plant Sciences (Sweden)

2014-07-01

A major challenge in evaluating the risks of radiation to organisms is that radioactive substances often co-occur with other contaminants in the environment. The combined effects of multiple contaminants is poorly understood, particularly where radiation is involved, but mixture toxicity can give rise to synergistic, antagonistic or additive effects. The challenge of understanding mixture toxicity in a radiation context is the focus of one of the work packages of the STAR EU Network of Excellence in Radioecology, of which this study is a part. This paper presents results from an experiment where the green micro-alga Pseudokirchneriella subcapitata was exposed to both acute external gamma irradiation and the toxic metal cadmium (Cd) (over 72 hours); the experiment had a fully factorial design with 4 gamma doses and 4 Cd concentrations. The endpoints measured were chosen to reflect subcellular, cellular and population-level effects: antioxidant enzyme expression; membrane damage; protein, vitamin and pigment content of the cells; individual cell biomass and growth; population growth (biomass per ml and cells per ml). Preliminary results suggest effects of both Cd and gamma on some of the cellular and subcellular endpoints such as thiamine (vitamin B1) and chlorophyll concentrations in the cells, and individual cell biomass. In some cases interactive effects of the combined Cd and gamma treatments were seen, and these appeared to be dose level dependent. This lack of a consistent pattern of interactive mixture toxicity effects across the endpoints measured means that such effects would be very hard to predict in a risk assessment context. The lack of measurable effects at the population level was probably due to the short experimental duration (72 hours). Other experiments in our research group on the same micro-alga species that have looked at longer term effects (weeks) have shown that effects may not manifest themselves until at least a week after an acute gamma

Recent progress in micro and nano-joining

Energy Technology Data Exchange (ETDEWEB)

Zhou, Y; Hu, A; Khan, M I; Wu, W; Tam, B; Yavuz, M [Centre for Advanced Materials Joining Department of Mechanical and Mechatronics Engineering, University of Waterloo 200 University Avenue West, Waterloo, N2L 3G1 (Canada)], E-mail: nzhou@uwaterloo.ca

2009-05-01

Micro and nano-joining has been identified as a key enabling technology in the construction of micromechanical and microelectronic devices. The current article reviews recent progress in micro and nano-joining. In particular, laser micro-welding (LMW) of crossed 316 LVM stainless steel (SS) wire was compared to conventional resistance micro-welding (RMW) and was successfully employed in welding a Pt-Ir /SS dissimilar combination. Welding of Au nanoparticles was realized using femtosecond laser irradiation and its application in the surface enhanced Raman spectroscopy was investigated. Brazing between carbon nanotube (CNT) bundles and Ni electrodes was attained in vacuum, resulting in the development of a novel CNT filament of incandescent lamps.

Peptostreptococcus micros in primary endodontic infections as detected by 16S rDNA-based polymerase chain reaction.

Science.gov (United States)

Siqueira, José F; Rôças, Isabela N; Andrade, Arnaldo F B; de Uzeda, Milton

2003-02-01

A 16S rDNA-based polymerase chain reaction (PCR) method was used to detect Peptostreptococcus micros in primary root canal infections. Samples were collected from 50 teeth having carious lesions, necrotic pulps, and different forms of periradicular diseases. DNA extracted from the samples was amplified using the PCR assay, which yielded a specific fragment of P. micros 16S rDNA. P. micros was detected in 6 of 22 root canals associated with asymptomatic chronic periradicular lesions (27.3%), 2 of 8 teeth with acute apical periodontitis (25%), and 6 of 20 cases of acute periradicular abscess (30%). In general, P. micros was found in 14 of 50 cases (28%). There was no correlation between the presence of P. micros and the occurrence of symptoms. Findings suggested that P. micros can be involved in the pathogenesis of different forms of periradicular lesions.

CT-Based Micro-Mechanical Approach to Predict Response of Closed-Cell Porous Biomaterials to Low-Velocity Impact

Directory of Open Access Journals (Sweden)

Mehrdad Koloushani

2018-03-01

Full Text Available In this study, a new numerical approach based on CT-scan images and finite element (FE method has been used to predict the mechanical behavior of closed-cell foams under impact loading. Micro-structural FE models based on CT-scan images of foam specimens (elastic-plastic material model with material constants of bulk aluminum and macro-mechanical FE models (with crushable foam material model with material constants of foams were constructed. Several experimental tests were also conducted to see which of the two noted (micro- or macro- mechanical FE models can better predict the deformation and force-displacement curves of foams. Compared to the macro-structural models, the results of the micro-structural models were much closer to the corresponding experimental results. This can be explained by the fact that the micro-structural models are able to take into account the interaction of stress waves with cell walls and the complex pathways the stress waves have to go through, while the macro-structural models do not have such capabilities. Despite their high demand for computational resources, using micro-scale FE models is very beneficial when one needs to understand the failure mechanisms acting in the micro-structure of a foam in order to modify or diminish them.

Droplet-based chemistry on a programmable micro-chip

Science.gov (United States)

Schwartz, Jon A.; Vykoukal, Jody V.; Gascoyne, Peter R. C.

2009-01-01

We describe the manipulation of aqueous droplets in an immiscible, low-permittivity suspending medium. Such droplets may serve as carriers for not only air- and water-borne samples, contaminants, chemical reagents, viral and gene products, and cells, but also the reagents to process and characterise these samples. We present proofs-of-concept for droplet manipulation through dielectrophoresis by: (1) moving droplets on a two-dimensional array of electrodes, (2) achieving dielectrically-activated droplet injection, (3) fusing and reacting droplets, and (4) conducting a basic biological assay through a combination of these steps. A long-term goal of this research is to provide a platform fluidic processor technology that can form the core of versatile, automated, micro-scale devices to perform chemical and biological assays at or near the point of care, which will increase the availability of modern medicine to people who do not have ready access to modern medical institutions, and decrease the cost and delays associated with that lack of access. PMID:15007434

Spike Neuromorphic VLSI-Based Bat Echolocation for Micro-Aerial Vehicle Guidance

Science.gov (United States)

2007-03-31

IFinal 03/01/04 - 02/28/07 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Neuromorphic VLSI-based Bat Echolocation for Micro-aerial 5b.GRANTNUMBER Vehicle...uncovered interesting new issues in our choice for representing the intensity of signals. We have just finished testing the first chip version of an echo...timing-based algorithm (’openspace’) for sonar-guided navigation amidst multiple obstacles. 15. SUBJECT TERMS Neuromorphic VLSI, bat echolocation

Realization of size controllable graphene micro/nanogap with a micro/nanowire mask method for organic field-effect transistors

DEFF Research Database (Denmark)

Liao, Zhiyu; Wan, Qing; Liu, Huixuan

2011-01-01

with the graphene micro/nanogap bottom electrodes. The ultrathin thickness of the graphene, combined with its good compatibility with organic semiconductors, and high electrical conductivity produced high-performance CuPc film device with mobility at 0.053 cm(2)/Vs and on/off ratio at 10(5), showing promising......A size controllable graphene micro/nanogap fabrication method using micro/nanowire as mask is presented. The gap dimension can be adjusted by the diameter of the mask wire. As a typical application, copper phthalocyanine (CuPc) film organic field-effect transistors (OFETs) were fabricated...

Micro-cogeneration units based on Stirling engine for heating and their real operation

Science.gov (United States)

Čierny, Jaroslav; Patsch, Marek

2014-08-01

This article was deal with micro-cogeneration units based on Stirling engine. We watched problematic of real working Stirling engine. The article also contain hookup of unit constructed at University of Zilina.

The multiphase flow system used in exploiting depleted reservoirs: water-based Micro-bubble drilling fluid

International Nuclear Information System (INIS)

Zheng Lihui; He Xiaoqing; Wang Xiangchun; Fu Lixia

2009-01-01

Water-based micro-bubble drilling fluid, which is used to exploit depleted reservoirs, is a complicated multiphase flow system that is composed of gas, water, oil, polymer, surfactants and solids. The gas phase is separate from bulk water by two layers and three membranes. They are 'surface tension reducing membrane', 'high viscosity layer', 'high viscosity fixing membrane', 'compatibility enhancing membrane' and 'concentration transition layer of liner high polymer (LHP) and surfactants' from every gas phase centre to the bulk water. 'Surface tension reducing membrane', 'high viscosity layer' and 'high viscosity fixing membrane' bond closely to pack air forming 'air-bag', 'compatibility enhancing membrane' and 'concentration transition layer of LHP and surfactants' absorb outside 'air-bag' to form 'incompact zone'. From another point of view, 'air-bag' and 'incompact zone' compose micro-bubble. Dynamic changes of 'incompact zone' enable micro-bubble to exist lonely or aggregate together, and lead the whole fluid, which can wet both hydrophilic and hydrophobic surface, to possess very high viscosity at an extremely low shear rate but to possess good fluidity at a higher shear rate. When the water-based micro-bubble drilling fluid encounters leakage zones, it will automatically regulate the sizes and shapes of the bubbles according to the slot width of fracture, the height of cavern as well as the aperture of openings, or seal them by making use of high viscosity of the system at a very low shear rate. Measurements of the rheological parameters indicate that water-based micro-bubble drilling fluid has very high plastic viscosity, yield point, initial gel, final gel and high ratio of yield point and plastic viscosity. All of these properties make the multiphase flow system meet the requirements of petroleum drilling industry. Research on interface between gas and bulk water of this multiphase flow system can provide us with information of synthesizing effective

Real-Time Particle Mass Spectrometry Based on Resonant Micro Strings

DEFF Research Database (Denmark)

Schmid, Silvan; Dohn, Søren; Boisen, Anja

2010-01-01

by measuring the resonant frequency shifts of the first two bending modes. The method has been tested by detecting the mass spectrum of micro particles placed on a micro string. This method enables real-time mass spectrometry necessary for applications such as personal monitoring devices for the assessment......Micro- and nanomechanical resonators are widely being used as mass sensors due to their unprecedented mass sensitivity. We present a simple closed-form expression which allows a fast and quantitative calculation of the position and mass of individual particles placed on a micro or nano string...

Technical assessment of a micro-cogeneration system based on polymer electrolyte membrane fuel cell and fluidized bed autothermal reformer

International Nuclear Information System (INIS)

Di Marcoberardino, Gioele; Roses, Leonardo; Manzolini, Giampaolo

2016-01-01

Highlights: • Performances of an ATR membrane reactor within a PEM FC micro-CHP system of 5 kWel. • Analysis of two different options for the H_2 permeate side: sweep and vacuum pump. • Optimization of operating conditions in terms of efficiency and membrane area. • Distribution of power and thermal consumptions and losses were discussed in detail. • A sensitivity analysis highlights the relevant design parameters of the CHP system. - Abstract: This work investigates the integration of an autothermal membrane reformer within a micro-CHP system of 5 kWel based on PEM fuel cell. The system modeled is based on a prototype developed within Reforcell European project. The optimization of the micro-CHP system is performed from a thermodynamic point of view aiming at the target of 40% of net electric efficiency and 90% of total system efficiency comparing different configuration and operating conditions. In particular, two hydrogen permeate side options as vacuum or sweep steam are evaluated together with different combination of feed temperature and pressures. A good compromise between electric efficiency (40%) and membrane surface area (0.3 m"2) was obtained for the sweep gas case at reaction side conditions of 8 bar, 600 °C and S/C of 2.5. Higher electric efficiency (40.5%) could be achieved by increasing the membrane surface area. The adoption of a vacuum pump simplifies the reactor design and manufacturing, but reduces the net electric efficiency by about 2% points with a membrane surface area of 0.15 m"2. Finally, the sensitivity analysis highlighted the influence of the main parameters and the design criteria for the definition of the CHP system.

Laminated chemical and physical micro-jet actuators based on conductive media

Science.gov (United States)

Gadiraju, Priya D.

2008-04-01

This dissertation presents the development of electrically-powered, lamination-based microactuators for the realization of large arrays of high impulse and short duration micro-jets with potential applications in the field of micro-electro-mechanical systems (MEMS). Microactuators offer unique control opportunities by converting the input electrical or chemical energy stored in a propellant into useful mechanical energy. This small and precise control obtained can potentially be applied towards aerodynamic control and transdermal drug delivery applications. This thesis work discusses the feasibility of using microactuators for two such applications: Control of the motion of a spinning projectile by utilizing the chemically-driven microjets ejected from the actuators, and enhancement of the permeability properties of skin by selectively ablating the stratum corneum layer of skin using the physical microjets ejected from the actuators. This enhanced permeability of skin can later be used for the delivery of high molecular weight drugs for transdermal drug delivery. The development of electrically powered microactuators starts by fabricating an array of radially firing microactuators using lamination-based microfabrication techniques that potentially enable batch fabrication at low cost. The microactuators of this thesis consist of three main parts: a micro chamber in which the propellant is stored; two electrode structures through which electrical energy is supplied to the propellant; and a micro nozzle through which the propellant or released gases from the propellant are expanded as a jet. Once the actuators are fabricated, they are integrated with MEMS-process-compatible propellants and optimized so as to produce instantaneous ignition of the propellant. This instantaneous ignition is achieved either by making the propellant itself conductive, thus, passing an electric current directly through the propellant; or by discharging an arc across the propellant by

Updating the Micro-Tom TILLING platform.

Science.gov (United States)

Okabe, Yoshihiro; Ariizumi, Tohru; Ezura, Hiroshi

2013-03-01

The dwarf tomato variety Micro-Tom is regarded as a model system for functional genomics studies in tomato. Various tomato genomic tools in the genetic background of Micro-Tom have been established, such as mutant collections, genome information and a metabolomic database. Recent advances in tomato genome sequencing have brought about a significant need for reverse genetics tools that are accessible to the larger community, because a great number of gene sequences have become available from public databases. To meet the requests from the tomato research community, we have developed the Micro-Tom Targeting-Induced Local Lesions IN Genomes (TILLING) platform, which is comprised of more than 5000 EMS-mutagenized lines. The platform serves as a reverse genetics tool for efficiently identifying mutant alleles in parallel with the development of Micro-Tom mutant collections. The combination of Micro-Tom mutant libraries and the TILLING approach enables researchers to accelerate the isolation of desirable mutants for unraveling gene function or breeding. To upgrade the genomic tool of Micro-Tom, the development of a new mutagenized population is underway. In this paper, the current status of the Micro-Tom TILLING platform and its future prospects are described.

Three-dimensional micro assembly of a hinged nickel micro device by magnetic lifting and micro resistance welding

International Nuclear Information System (INIS)

Chang, Chun-Wei; Hsu, Wensyang

2009-01-01

The three-dimensional micro assembly of hinged nickel micro devices by magnetic lifting and micro resistance welding is proposed here. By an electroplating-based surface machining process, the released nickel structure with the hinge mechanism can be fabricated. Lifting of the released micro structure to different tilted angles is accomplished by controlling the positions of a magnet beneath the device. An in situ electro-thermal actuator is used here to provide the pressing force in micro resistance welding for immobilizing the tilted structure. The proposed technique is shown to immobilize micro devices at controlled angles ranging from 14° to 90° with respect to the substrate. Design parameters such as the electro-thermal actuator and welding beam width are also investigated. It is found that there is a trade-off in beam width design between large contact pressure and low thermal deformation. Different dominated effects from resistivity enhancement and contact area enlargement during the welding process are also observed in the dynamic resistance curves. Finally, a lifted and immobilized electro-thermal bent-beam actuator is shown to displace upward about 27.7 µm with 0.56 W power input to demonstrate the capability of electrical transmission at welded joints by the proposed 3D micro assembly technique

Design of a micro-irrigation system based on the control volume method

Directory of Open Access Journals (Sweden)

Chasseriaux G.

2006-01-01

Full Text Available A micro-irrigation system design based on control volume method using the back step procedure is presented in this study. The proposed numerical method is simple and consists of delimiting an elementary volume of the lateral equipped with an emitter, called « control volume » on which the conservation equations of the fl uid hydrodynamicʼs are applied. Control volume method is an iterative method to calculate velocity and pressure step by step throughout the micro-irrigation network based on an assumed pressure at the end of the line. A simple microcomputer program was used for the calculation and the convergence was very fast. When the average water requirement of plants was estimated, it is easy to choose the sum of the average emitter discharge as the total average fl ow rate of the network. The design consists of exploring an economical and effi cient network to deliver uniformly the input fl ow rate for all emitters. This program permitted the design of a large complex network of thousands of emitters very quickly. Three subroutine programs calculate velocity and pressure at a lateral pipe and submain pipe. The control volume method has already been tested for lateral design, the results from which were validated by other methods as fi nite element method, so it permits to determine the optimal design for such micro-irrigation network

Toward single enzyme analysis in a droplet-based micro and nanofluidic system

NARCIS (Netherlands)

Arayanarakool, Rerngchai

2012-01-01

In this thesis, we have demonstrated the application of micro- and nanofluidic devices to generate an array of aqueous droplets in oil phase for single-enzyme encapsulation and activity measurement. We chose droplet-based microfluidics for this purpose of monitoring single-enzyme reactions since the

Optimal Control of Micro Grid Operation Mode Seamless Switching Based on Radau Allocation Method

Science.gov (United States)

Chen, Xiaomin; Wang, Gang

2017-05-01

The seamless switching process of micro grid operation mode directly affects the safety and stability of its operation. According to the switching process from island mode to grid-connected mode of micro grid, we establish a dynamic optimization model based on two grid-connected inverters. We use Radau allocation method to discretize the model, and use Newton iteration method to obtain the optimal solution. Finally, we implement the optimization mode in MATLAB and get the optimal control trajectory of the inverters.

Manufacture of micro fluidic devices by laser welding using thermal transfer printing techniques

Science.gov (United States)

Klein, R.; Klein, K. F.; Tobisch, T.; Thoelken, D.; Belz, M.

2016-03-01

Micro-fluidic devices are widely used today in the areas of medical diagnostics and drug research, as well as for applications within the process, electronics and chemical industry. Microliters of fluids or single cell to cell interactions can be conveniently analyzed with such devices using fluorescence imaging, phase contrast microscopy or spectroscopic techniques. Typical micro-fluidic devices consist of a thermoplastic base component with chambers and channels covered by a hermetic fluid and gas tight sealed lid component. Both components are usually from the same or similar thermoplastic material. Different mechanical, adhesive or thermal joining processes can be used to assemble base component and lid. Today, laser beam welding shows the potential to become a novel manufacturing opportunity for midsize and large scale production of micro-fluidic devices resulting in excellent processing quality by localized heat input and low thermal stress to the device during processing. For laser welding, optical absorption of the resin and laser wavelength has to be matched for proper joining. This paper will focus on a new approach to prepare micro-fluidic channels in such devices using a thermal transfer printing process, where an optical absorbing layer absorbs the laser energy. Advantages of this process will be discussed in combination with laser welding of optical transparent micro-fluidic devices.

Micro-resonators based on integrated polymer technology for optical sensing

OpenAIRE

Girault , Pauline; Lemaitre , Jonathan; Guendouz , Mohammed; Lorrain , Nathalie; Poffo , Luiz; Gadonna , Michel; Bosc , Dominique

2014-01-01

International audience; Research on sensors has experienced a noticeable development over the last decades especially in label free optical biosensors. However, compact sensors without markers for rapid, reliable and inexpensive detection of various substances induces a significant research of new technological solutions. The context of this work is the development of a sensor based on easily integrated and inexpensive micro-resonator (MR) component in integrated optics, highly sensitive and ...

An Overview on the Field of Micro- and Nanotechnologies for Synthetic Peptide-Based Vaccines

Directory of Open Access Journals (Sweden)

Aiala Salvador

2011-01-01

Full Text Available The development of synthetic peptide-based vaccines has many advantages in comparison with vaccines based on live attenuated organisms, inactivated or killed organism, or toxins. Peptide-based vaccines cannot revert to a virulent form, allow a better conservation, and are produced more easily and safely. However, they generate a weaker immune response than other vaccines, and the inclusion of adjuvants and/or the use of vaccine delivery systems is almost always needed. Among vaccine delivery systems, micro- and nanoparticulated ones are attractive, because their particulate nature can increase cross-presentation of the peptide. In addition, they can be passively or actively targeted to antigen presenting cells. Furthermore, particulate adjuvants are able to directly activate innate immune system in vivo. Here, we summarize micro- and nanoparticulated vaccine delivery systems used in the field of synthetic peptide-based vaccines as well as strategies to increase their immunogenicity.

Accelerated testing of solid oxide fuel cell stacks for micro combined heat and power application

DEFF Research Database (Denmark)

Hagen, Anke; Høgh, Jens Valdemar Thorvald; Barfod, Rasmus

2015-01-01

State-of-the-art (SoA) solid oxide fuel cell (SOFC) stacks are tested using profiles relevant for use in micro combined heat and power (CHP) units. Such applications are characterised by dynamic load profiles. In order to shorten the needed testing time and to investigate potential acceleration...... of degradation, the profiles are executed faster than required for real applications. Operation with fast load cycling, both using hydrogen and methane/steam as fuels, does not accelerate degradation compared to constant operation, which demonstrates the maturity of SoA stacks and enables transferring knowledge...... effect for long life-times than regular short time changes of operation. In order to address lifetime testing it is suggested to build a testing program consisting of defined modules that represent different application profiles, such as one module at constant conditions, followed by modules at one set...

Biomarker MicroRNAs for Diagnosis of Oral Squamous Cell Carcinoma Identified Based on Gene Expression Data and MicroRNA-mRNA Network Analysis

Science.gov (United States)

Zhang, Hui; Li, Tangxin; Zheng, Linqing

2017-01-01

Oral squamous cell carcinoma is one of the most malignant tumors with high mortality rate worldwide. Biomarker discovery is critical for early diagnosis and precision treatment of this disease. MicroRNAs are small noncoding RNA molecules which often regulate essential biological processes and are good candidates for biomarkers. By integrative analysis of both the cancer-associated gene expression data and microRNA-mRNA network, miR-148b-3p, miR-629-3p, miR-27a-3p, and miR-142-3p were screened as novel diagnostic biomarkers for oral squamous cell carcinoma based on their unique regulatory abilities in the network structure of the conditional microRNA-mRNA network and their important functions. These findings were confirmed by literature verification and functional enrichment analysis. Future experimental validation is expected for the further investigation of their molecular mechanisms. PMID:29098014

Experimental and numerical study of micro deep drawing

Directory of Open Access Journals (Sweden)

Luo Liang

2015-01-01

Full Text Available Micro forming is a key technology for an industrial miniaturisation trend, and micro deep drawing (MDD is a typical micro forming method. It has great advantages comparing to other micro manufacturing methods, such as net forming ability, mass production potential, high product quality and complex 3D metal products fabrication capacity. Meanwhile, it is facing difficulties, for example the so-called size effects, once scaled down to micro scale. To investigate and to solve the problems in MDD, a combined micro blanking-drawing machine is employed and an explicit-implicit micro deep drawing model with a voronoi blank model is developed. Through heat treatment different grain sizes can be obtained, which affect material's properties and, consequently, the drawing process parameters, as well as produced cups' quality. Further, a voronoi model can provide detailed material information in simulation, and numerical simulation results are in accordance with experimental results.

Application of flexible micro temperature sensor in oxidative steam reforming by a methanol micro reformer.

Science.gov (United States)

Lee, Chi-Yuan; Lee, Shuo-Jen; Shen, Chia-Chieh; Yeh, Chuin-Tih; Chang, Chi-Chung; Lo, Yi-Man

2011-01-01

Advances in fuel cell applications reflect the ability of reformers to produce hydrogen. This work presents a flexible micro temperature sensor that is fabricated based on micro-electro-mechanical systems (MEMS) technology and integrated into a flat micro methanol reformer to observe the conditions inside that reformer. The micro temperature sensor has higher accuracy and sensitivity than a conventionally adopted thermocouple. Despite various micro temperature sensor applications, integrated micro reformers are still relatively new. This work proposes a novel method for integrating micro methanol reformers and micro temperature sensors, subsequently increasing the methanol conversion rate and the hydrogen production rate by varying the fuel supply rate and the water/methanol ratio. Importantly, the proposed micro temperature sensor adequately controls the interior temperature during oxidative steam reforming of methanol (OSRM), with the relevant parameters optimized as well.

Application of Flexible Micro Temperature Sensor in Oxidative Steam Reforming by a Methanol Micro Reformer

Directory of Open Access Journals (Sweden)

Yi-Man Lo

2011-02-01

Full Text Available Advances in fuel cell applications reflect the ability of reformers to produce hydrogen. This work presents a flexible micro temperature sensor that is fabricated based on micro-electro-mechanical systems (MEMS technology and integrated into a flat micro methanol reformer to observe the conditions inside that reformer. The micro temperature sensor has higher accuracy and sensitivity than a conventionally adopted thermocouple. Despite various micro temperature sensor applications, integrated micro reformers are still relatively new. This work proposes a novel method for integrating micro methanol reformers and micro temperature sensors, subsequently increasing the methanol conversion rate and the hydrogen production rate by varying the fuel supply rate and the water/methanol ratio. Importantly, the proposed micro temperature sensor adequately controls the interior temperature during oxidative steam reforming of methanol (OSRM, with the relevant parameters optimized as well.

Wafer-scale micro-optics fabrication

Science.gov (United States)

Voelkel, Reinhard

2012-07-01

Micro-optics is an indispensable key enabling technology for many products and applications today. Probably the most prestigious examples are the diffractive light shaping elements used in high-end DUV lithography steppers. Highly-efficient refractive and diffractive micro-optical elements are used for precise beam and pupil shaping. Micro-optics had a major impact on the reduction of aberrations and diffraction effects in projection lithography, allowing a resolution enhancement from 250 nm to 45 nm within the past decade. Micro-optics also plays a decisive role in medical devices (endoscopes, ophthalmology), in all laser-based devices and fiber communication networks, bringing high-speed internet to our homes. Even our modern smart phones contain a variety of micro-optical elements. For example, LED flash light shaping elements, the secondary camera, ambient light and proximity sensors. Wherever light is involved, micro-optics offers the chance to further miniaturize a device, to improve its performance, or to reduce manufacturing and packaging costs. Wafer-scale micro-optics fabrication is based on technology established by the semiconductor industry. Thousands of components are fabricated in parallel on a wafer. This review paper recapitulates major steps and inventions in wafer-scale micro-optics technology. The state-of-the-art of fabrication, testing and packaging technology is summarized.

Active tracking system for visible light communication using a GaN-based micro-LED and NRZ-OOK.

Science.gov (United States)

Lu, Zhijian; Tian, Pengfei; Chen, Hong; Baranowski, Izak; Fu, Houqiang; Huang, Xuanqi; Montes, Jossue; Fan, Youyou; Wang, Hongyi; Liu, Xiaoyan; Liu, Ran; Zhao, Yuji

2017-07-24

Visible light communication (VLC) holds the promise of a high-speed wireless network for indoor applications and competes with 5G radio frequency (RF) system. Although the breakthrough of gallium nitride (GaN) based micro-light-emitting-diodes (micro-LEDs) increases the -3dB modulation bandwidth exceptionally from tens of MHz to hundreds of MHz, the light collected onto a fast photo receiver drops dramatically, which determines the signal to noise ratio (SNR) of VLC. To fully implement the practical high data-rate VLC link enabled by a GaN-based micro-LED, it requires focusing optics and a tracking system. In this paper, we demonstrate an active on-chip tracking system for VLC using a GaN-based micro-LED and none-return-to-zero on-off keying (NRZ-OOK). Using this novel technique, the field of view (FOV) was enlarged to 120° and data rates up to 600 Mbps at a bit error rate (BER) of 2.1×10 -4 were achieved without manual focusing. This paper demonstrates the establishment of a VLC physical link that shows enhanced communication quality by orders of magnitude, making it optimized for practical communication applications.

Controlled delivery of acyclovir from porous silicon micro- and nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Maniya, Nalin H.; Patel, Sanjaykumar R.; Murthy, Z.V.P., E-mail: zvpm2000@yahoo.com

2015-03-01

Graphical abstract: - Highlights: • Porous silicon (PSi) was fabricated by electrochemical etching process. • Micro- and nanoparticles were prepared by ultrasonic fracture of PSi films. • Acyclovir was loaded into native, oxidized, and hydrosilylated PSi particles. • Micro- and nanoparticles displays controlled release behaviour for several days. • Drug release behaviour and release kinetics from PSi particles were studied. - Abstract: In this work, micro- and nanoparticles of porous silicon (PSi) are demonstrated to act as effective carrier for the controlled delivery of acyclovir (ACV). PSi films prepared by electrochemical etching were fractured by ultrasonication to prepare micro- and nanoparticles. PSi native particles were thermally oxidized (TOPSi) and thermally hydrosilylated using undecylenic acid (UnPSi). PSi particles with three different surface chemistries were then loaded with ACV by physical adsorption and covalent attachment. Such particles were characterized by scanning electron microscopy, dynamic light scattering, and Fourier transform infrared spectroscopy. In vitro ACV release experiments in phosphate buffered saline showed sustained release behaviour from both micro- and nanoparticles and order of release was found to be native PSi > TOPSi > UnPSi. Drug release kinetics study using Korsmeyer-Peppas model suggested a combination of both drug diffusion and Si scaffold erosion based drug release mechanisms.

Controlled delivery of acyclovir from porous silicon micro- and nanoparticles

International Nuclear Information System (INIS)

Maniya, Nalin H.; Patel, Sanjaykumar R.; Murthy, Z.V.P.

2015-01-01

Graphical abstract: - Highlights: • Porous silicon (PSi) was fabricated by electrochemical etching process. • Micro- and nanoparticles were prepared by ultrasonic fracture of PSi films. • Acyclovir was loaded into native, oxidized, and hydrosilylated PSi particles. • Micro- and nanoparticles displays controlled release behaviour for several days. • Drug release behaviour and release kinetics from PSi particles were studied. - Abstract: In this work, micro- and nanoparticles of porous silicon (PSi) are demonstrated to act as effective carrier for the controlled delivery of acyclovir (ACV). PSi films prepared by electrochemical etching were fractured by ultrasonication to prepare micro- and nanoparticles. PSi native particles were thermally oxidized (TOPSi) and thermally hydrosilylated using undecylenic acid (UnPSi). PSi particles with three different surface chemistries were then loaded with ACV by physical adsorption and covalent attachment. Such particles were characterized by scanning electron microscopy, dynamic light scattering, and Fourier transform infrared spectroscopy. In vitro ACV release experiments in phosphate buffered saline showed sustained release behaviour from both micro- and nanoparticles and order of release was found to be native PSi > TOPSi > UnPSi. Drug release kinetics study using Korsmeyer-Peppas model suggested a combination of both drug diffusion and Si scaffold erosion based drug release mechanisms

Cost-effective optical fiber pressure sensor based on intrinsic Fabry-Perot interferometric micro-cavities

Science.gov (United States)

Domingues, M. Fátima; Rodriguez, Camilo A.; Martins, Joana; Tavares, Cátia; Marques, Carlos; Alberto, Nélia; André, Paulo; Antunes, Paulo

2018-05-01

In this work, a cost-effective procedure to manufacture optical fiber pressure sensors is presented. This has a high relevance for integration in robotic exoskeletons or for gait plantar pressure monitoring within the physical rehabilitation scenarios, among other applications. The sensing elements are based on Fabry-Perot interferometric (FPI) micro-cavities, created from the recycling of optical fibers previously destroyed by the catastrophic fuse effect. To produce the pressure sensors, the fiber containing the FPI micro-cavities was embedded in an epoxy resin cylinder used as pressure transducer and responsible to transfer the pressure applied on its surface to the optical fiber containing the FPI micro-cavity. Before the embedding process, some FPI sensors were also characterized to strain variations. After that, the effect of the encapsulation of the FPI structure into the resin was assessed, from which a slight decrease on the FPI interferogram fringes visibility was verified, indicating a small increase in the micro-cavity length. Up on the sensors characterization, a linear dependence of the wavelength shift with the induced pressure was obtained, which leads to a maximum sensitivity of 59.39 ± 1.7 pm/kPa. Moreover, direct dependence of the pressure sensitivity with the micro-cavity volume and length was found.

Image Reconstruction and Evaluation: Applications on Micro-Surfaces and Lenna Image Representation

Directory of Open Access Journals (Sweden)

Mohammad Mayyas

2016-09-01

Full Text Available This article develops algorithms for the characterization and the visualization of micro-scale features using a small number of sample points, with the goal of mitigating the measurement shortcomings, which are often destructive or time consuming. The popular measurement techniques that are used in imaging of micro-surfaces include the 3D stylus or interferometric profilometry and Scanning Electron Microscopy (SEM, where both could represent the micro-surface characteristics in terms of 3D dimensional topology and greyscale image, respectively. Such images could be highly dense; therefore, traditional image processing techniques might be computationally expensive. We implement the algorithms in several case studies to rapidly examine the microscopic features of micro-surface of Microelectromechanical System (MEMS, and then we validate the results using a popular greyscale image; i.e., “Lenna” image. The contributions of this research include: First, development of local and global algorithm based on modified Thin Plate Spline (TPS model to reconstruct high resolution images of the micro-surface’s topography, and its derivatives using low resolution images. Second, development of a bending energy algorithm from our modified TPS model for filtering out image defects. Finally, development of a computationally efficient technique, referred to as Windowing, which combines TPS and Linear Sequential Estimation (LSE methods, to enhance the visualization of images. The Windowing technique allows rapid image reconstruction based on the reduction of inverse problem.

Micro Mobility Marketing

DEFF Research Database (Denmark)

Hosbond, Jens Henrik; Skov, Mikael B.

2008-01-01

, in our case a medium-sized retail supermarket. Two prototypes based on push and pull marketing strategies are implemented and evaluated. Taking outset in a synthesis of central issues in contemporary research on mobile marketing, we discuss their role in micro mobility marketing to point to similarities......Mobile marketing refers to marketing of services or goods using mobile technology and mobile marketing holds potentially great economical opportunities. Traditionally, mobile marketing has been viewed as mobility in the large taking place virtually anywhere, anytime. Further, research shows...... considerable number of studies on push-based SMS mobile marketing campaigns. This paper explores a related yet different form of mobile marketing namely micro mobility marketing. Micro mobility marketing denotes mobility in the small, meaning that promotion of goods takes place within a circumscribed location...

Exploring domestic micro-cogeneration in the Netherlands: An agent-based demand model for technology diffusion

International Nuclear Information System (INIS)

Faber, Albert; Valente, Marco; Janssen, Peter

2010-01-01

Micro-cogeneration (micro-CHP) is a new technology at the household level, producing electricity in cogeneration with domestic heating, thereby increasing the overall efficiency of domestic energy production. We have developed a prototypical agent-based simulation model for energy technologies competing for demand at the consumer level. The model is specifically geared towards the competition between micro-CHP and incumbent condensing boilers. In the model, both technologies compete on purchase price and costs of usage, to which various (types of) consumers decide on the installation of either technology. Simulations with various gas and electricity prices show that micro-CHP diffusion could be seriously inhibited if demand for natural gas decreases, e.g. due to insulation measures. Further simulations explore various subsidy schemes. A subsidy for purchase is only found to be effective within a limited range of Euro 1400-3250. A subsidy based on decreasing price difference between the competing technologies is much more cost effective than fixed purchase subsidies. Simulations of a subsidy scheme for usage show that a fast market penetration can be reached, but this does not yet take full advantage of technological progress in terms of decreasing CO 2 emissions. Selection of the most effective scheme thus depends on the policy criteria assumed.

Fabrication of a Flexible Micro CO Sensor for Micro Reformer Applications

Directory of Open Access Journals (Sweden)

Yi-Man Lo

2010-11-01

Full Text Available Integration of a reformer and a proton exchange membrane fuel cell (PEMFC is problematic due to the presence in the gas from the reforming process of a slight amount of carbon monoxide. Carbon monoxide poisons the catalyst of the proton exchange membrane fuel cell subsequently degrading the fuel cell performance, and necessitating the sublimation of the reaction gas before supplying to fuel cells. Based on the use of micro-electro-mechanical systems (MEMS technology to manufacture flexible micro CO sensors, this study elucidates the relation between a micro CO sensor and different SnO2 thin film thicknesses. Experimental results indicate that the sensitivity increases at temperatures ranging from 100–300 °C. Additionally, the best sensitivity is obtained at a specific temperature. For instance, the best sensitivity of SnO2 thin film thickness of 100 nm at 300 °C is 59.3%. Moreover, a flexible micro CO sensor is embedded into a micro reformer to determine the CO concentration in each part of a micro reformer in the future, demonstrating the inner reaction of a micro reformer in depth and immediate detection.

Geometry and surface damage in micro electrical discharge machining of micro-holes

Science.gov (United States)

Ekmekci, Bülent; Sayar, Atakan; Tecelli Öpöz, Tahsin; Erden, Abdulkadir

2009-10-01

Geometry and subsurface damage of blind micro-holes produced by micro electrical discharge machining (micro-EDM) is investigated experimentally to explore the relational dependence with respect to pulse energy. For this purpose, micro-holes are machined with various pulse energies on plastic mold steel samples using a tungsten carbide tool electrode and a hydrocarbon-based dielectric liquid. Variations in the micro-hole geometry, micro-hole depth and over-cut in micro-hole diameter are measured. Then, unconventional etching agents are applied on the cross sections to examine micro structural alterations within the substrate. It is observed that the heat-damaged segment is composed of three distinctive layers, which have relatively high thicknesses and vary noticeably with respect to the drilling depth. Crack formation is identified on some sections of the micro-holes even by utilizing low pulse energies during machining. It is concluded that the cracking mechanism is different from cracks encountered on the surfaces when machining is performed by using the conventional EDM process. Moreover, an electrically conductive bridge between work material and debris particles is possible at the end tip during machining which leads to electric discharges between the piled segments of debris particles and the tool electrode during discharging.

Geometry and surface damage in micro electrical discharge machining of micro-holes

International Nuclear Information System (INIS)

Ekmekci, Bülent; Sayar, Atakan; Öpöz, Tahsin Tecelli; Erden, Abdulkadir

2009-01-01

Geometry and subsurface damage of blind micro-holes produced by micro electrical discharge machining (micro-EDM) is investigated experimentally to explore the relational dependence with respect to pulse energy. For this purpose, micro-holes are machined with various pulse energies on plastic mold steel samples using a tungsten carbide tool electrode and a hydrocarbon-based dielectric liquid. Variations in the micro-hole geometry, micro-hole depth and over-cut in micro-hole diameter are measured. Then, unconventional etching agents are applied on the cross sections to examine micro structural alterations within the substrate. It is observed that the heat-damaged segment is composed of three distinctive layers, which have relatively high thicknesses and vary noticeably with respect to the drilling depth. Crack formation is identified on some sections of the micro-holes even by utilizing low pulse energies during machining. It is concluded that the cracking mechanism is different from cracks encountered on the surfaces when machining is performed by using the conventional EDM process. Moreover, an electrically conductive bridge between work material and debris particles is possible at the end tip during machining which leads to electric discharges between the piled segments of debris particles and the tool electrode during discharging

A Study of the Influence of Gas Channel Parameters on HT-PEM Fuel Cell Performance Using FEM Analysis

Directory of Open Access Journals (Sweden)

Ionescu Viorel

2016-01-01

Full Text Available Proton Exchange Membrane Fuel Cells (PEMFC are highly efficient power generators, achieving up to 50–60% conversion efficiency, even in sizes of a few kilowatts. Comsol Multiphysics, a commercial solver based on the Finite Element Method (FEM was used for developing a three dimensional model of a high temperature PEMFC that can deal with both anode and cathode flow field for examining the micro flow channel with electrochemical reaction. Cathode gas flow velocity influence on the cell performance was investigated at first. Polarization curves for three different channel widths (0.8, 1.6 and 2.4 mm and three different channel depths (1, 2 and 3 mm were computed at a cathode inlet flow velocity of 0.06 m/s. Oxygen molar concentration at cathode catalyst layer-GDL channel interface and local current density variation along the cell length were also studied for specific gas channel geometries.

A study on the beta voltaic micro-nuclear battery based on the planar technology silicon detector

International Nuclear Information System (INIS)

Zhang Kai; He Gaokui; Huang Xiaojian; Liu Yang; Meng Xin; Hao Xiaoyong

2011-01-01

It describes briefly the beta voltaic micro-nuclear battery based on the planar technology silicon detector and radioisotope. Different sensitive area of silicon detectors are used to cooperate with 63 Ni source to buildup of beta voltaic micro-nuclear batteries. The experimental data show that the larger sensitive area the silicon detector has, the higher open circuit voltage it produces, and the open circuit voltage of single cell has reached an excellent result from 0.15 V to 0.30 V. It is possible to get high output power by series or parallel connecting the beta voltaic micro-nuclear batteries. (authors)

Study on wake structure characteristics of a slotted micro-ramp with large-eddy simulation

Energy Technology Data Exchange (ETDEWEB)

Dong, Xiangrui; Chen, Yaohui; Dong, Gang; Liu, Yixin, E-mail: cyh873@163.com [National Key Laboratory of Transient Physics, Nanjing University of Science and Technology, Nanjing, 210094 (China)

2017-06-15

In this paper, a novel slotted ramp-type micro vortex generator (slotted micro-ramp) for flow separation control is simulated in the supersonic flow of Ma = 1.5, based on large eddy simulation combined with the finite volume method. The wake structure characteristics and control mechanisms of both slotted and standard micro-ramps are presented and discussed. The results show that the wake of standard micro-ramp includes a primary counter-rotating streamwise vortex pair, a train of vortex rings, and secondary vortices. The slotted micro-ramp has more complicated wake structures, which contain a confluent counter-rotating streamwise vortex pair and additional streamwise vortices, with the same rotation generated by slot and the vortex rings enveloping the vortex pair. The additional vortices generated by the slot of the micro-ramp can mix with the primary counter-rotating vortex pair, extend the life time, and strengthen the vortex intensity of primary vortex pair. Moreover, the slot can effectively alleviate, or even eliminate the backflow and decrease the profile drag induced by the standard micro-ramp, therefore improving the efficiency of separation control. (paper)

Combination process of diamond machining and roll-to-roll UV-replication for thin film micro- and nanostructures

Science.gov (United States)

Väyrynen, J.; Mönkkönen, K.; Siitonen, S.

2016-09-01

Roll-to-roll (R2R) ultraviolet (UV) curable embossing replication process is a highly accurate and cost effective way to replicate large quantities of thin film polymer parts. These structures can be used for microfluidics, LED-optics, light guides, displays, cameras, diffusers, decorative, laser sensing and measuring devices. In the R2R UV-process, plastic thin film coated with UV-curable lacquer, passes through an imprinting embossing drum and is then hardened by an UV-lamp. One key element for mastering this process is the ability to manufacture a rotating drum containing micro- and nanostructures. Depending on the pattern shapes, the drum can be directly machined by diamond machining or it can be done through wafer level lithographical process. Due to the shrinkage of UV-curable lacquer, the R2R drum pattern process needs to be prototyped few times, in order to get the desired performance and shape from the R2R produced part. To speed up the prototyping and overall process we have developed a combination process where planar diamond machining patterns are being turned into a drum roller. Initially diamond machined patterns from a planar surface are replicated on a polymer sheet using UV-replication. Secondly, a nickel stamper shim is grown form the polymer sheet and at the end the stamper is turned into a roller and used in the R2R process. This process allows various micro milled, turned, grooved and ruled structures to be made at thin film products through the R2R process. In this paper, the process flow and examples of fabricating R2R embossed UVcurable thin film micro- and nanostructures from planar diamond machined patterns, is reported.

Magnetic field concentration using ferromagnetic material to propel a wireless power transfer based micro-robot

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Dongwook Kim

2018-05-01

Full Text Available In this paper, we propose a novel coil structure, using a ferromagnetic material which concentrates the magnetic field, as the propulsion system of a wireless power transfer (WPT based micro-robot. This structure uses an incident magnetic field to induce current during wireless power transfer, to generate a Lorentz force. To prevent net cancelation of the Lorentz force in the load coil, ferrite films were applied to one side of the coil segment. The demonstrated simplicity and effectiveness of the proposed micro-robot showed its suitability for applications. Simulation and experimental results confirmed a velocity of 1.02 mm/s with 6 mW power transfer capacity for the 3 mm sized micro-robot.

Magnetic field concentration using ferromagnetic material to propel a wireless power transfer based micro-robot

Science.gov (United States)

Kim, Dongwook; Park, Bumjin; Park, Jaehyoung; Park, Hyun Ho; Ahn, Seungyoung

2018-05-01

In this paper, we propose a novel coil structure, using a ferromagnetic material which concentrates the magnetic field, as the propulsion system of a wireless power transfer (WPT) based micro-robot. This structure uses an incident magnetic field to induce current during wireless power transfer, to generate a Lorentz force. To prevent net cancelation of the Lorentz force in the load coil, ferrite films were applied to one side of the coil segment. The demonstrated simplicity and effectiveness of the proposed micro-robot showed its suitability for applications. Simulation and experimental results confirmed a velocity of 1.02 mm/s with 6 mW power transfer capacity for the 3 mm sized micro-robot.

Core Flooding Experiments Combined with X-rays and Micro-PET Imaging as a Tool to Calculate Fluid Saturations in a Fracture

Science.gov (United States)

Gran, M.; Zahasky, C.; Garing, C.; Pollyea, R. M.; Benson, S. M.

2017-12-01

One way to reduce CO2 emissions is to capture CO2 generated in power plants and other industrial sources to inject it into a geological formation. Sedimentary basins are the ones traditionally used to store CO2 but the emission sources are not always close to these type of basins. In this case, basalt rocks present a good storage alternative due their extent and also their potential for mineral trapping. Flow through basaltic rocks is governed by the permeable paths provided by rock fractures. Hence, knowing the behavior of the multiphase flow in these fractures becomes crucial. With the aim to describe how aperture and liquid-gas interface changes in the fracture affect relative permeability and what are the implications of permeability stress dependency, a series of core experiments were conducted. To calculate fracture apertures and fluid saturations, core flooding experiments combined with medical X-Ray CT scanner and micro-PET imaging (Micro Positron Emission Tomography) were performed. Capillary pressure and relative permeability drainage curves were simultaneously measured in a fractured basalt core under typical storage reservoir pressures and temperatures. The X-Ray scanner allows fracture apertures to be measured quite accurately even for fractures as small as 30 µ, but obtaining fluid saturations is not straightforward. The micro-PET imaging provides dynamic measurements of tracer distributions which can be used to calculate saturation. Here new experimental data is presented and the challenges associated with measuring fluid saturations using both X-Rays and micro-PET are discussed.

The bounds on tracking performance utilising a laser-based linear and angular sensing and measurement methodology for micro/nano manipulation

International Nuclear Information System (INIS)

Clark, Leon; Shirinzadeh, Bijan; Tian, Yanling; Zhong, Yongmin

2014-01-01

This paper presents an analysis of the tracking performance of a planar three degrees of freedom (DOF) flexure-based mechanism for micro/nano manipulation, utilising a tracking methodology for the measurement of coupled linear and angular motions. The methodology permits trajectories over a workspace with large angular range through the reduction of geometric errors. However, when combining this methodology with feedback control systems, the accuracy of performed manipulations can only be stated within the bounds of the uncertainties in measurement. The dominant sources of error and uncertainty within each sensing subsystem are therefore identified, which leads to a formulation of the measurement uncertainty in the final system outputs, in addition to methods of reducing their magnitude. Specific attention is paid to the analysis of the vision-based subsystem utilised for the measurement of angular displacement. Furthermore, a feedback control scheme is employed to minimise tracking errors, and the coupling of certain measurement errors is shown to have a detrimental effect on the controller operation. The combination of controller tracking errors and measurement uncertainty provides the bounds on the final tracking performance. (paper)

Polypyrrole-magnetite dispersive micro-solid-phase extraction combined with ultraviolet-visible spectrophotometry for the determination of rhodamine 6G and crystal violet in textile wastewater.

Science.gov (United States)

Kamaruddin, Amirah Farhan; Sanagi, Mohd Marsin; Wan Ibrahim, Wan Aini; Md Shukri, Dyia S; Abdul Keyon, Aemi S

2017-11-01

Polypyrrole-magnetite dispersive micro-solid-phase extraction method combined with ultraviolet-visible spectrophotometry was developed for the determination of selected cationic dyes in textile wastewater. Polypyrrole-magnetite was used as adsorbent due to its thermal stability, magnetic properties, and ability to adsorb Rhodamine 6G and crystal violet. Dispersive micro-solid-phase extraction parameters were optimized, including sample pH, adsorbent amount, extraction time, and desorption solvent. The optimum polypyrrole-magnetite dispersive micro-solid phase-extraction conditions were sample pH 8, 60 mg polypyrrole-magnetite adsorbent, 5 min of extraction time, and acetonitrile as the desorption solvent. Under the optimized conditions, the polypyrrole-magnetite dispersive micro-solid-phase extraction with ultraviolet-visible method showed good linearity in the range of 0.05-7 mg/L (R 2  > 0.9980). The method also showed a good limit of detection for the dyes (0.05 mg/L) and good analyte recoveries (97.4-111.3%) with relative standard deviations extraction and determination of dyes at trace concentration levels. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of the adaptation of zirconia-based fixed partial dentures using micro-CT technology

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Marcia Borba

2013-09-01

Full Text Available The objective of the study was to measure the marginal and internal fit of zirconia-based all-ceramic three-unit fixed partial dentures (FPDs (Y-TZP - LAVA, 3M-ESPE, using a novel methodology based on micro-computed tomography (micro-CT technology. Stainless steel models of prepared abutments were fabricated to design FPDs. Ten frameworks were produced with 9 mm2 connector cross-sections using a LAVATM CAD-CAM system. All FPDs were veneered with a compatible porcelain. Each FPD was seated on the original model and scanned using micro-CT. Files were processed using NRecon and CTAn software. Adobe Photoshop and Image J software were used to analyze the cross-sectional images. Five measuring points were selected, as follows: MG - marginal gap; CA - chamfer area; AW - axial wall; AOT - axio-occlusal transition area; OA - occlusal area. Results were statistically analyzed by Kruskall-Wallis and Tukey's post hoc test (α= 0.05. There were significant differences for the gap width between the measurement points evaluated. MG showed the smallest median gap width (42 µm. OA had the highest median gap dimension (125 µm, followed by the AOT point (105 µm. CA and AW gap width values were statistically similar, 66 and 65 µm respectively. Thus, it was possible to conclude that different levels of adaptation were observed within the FPD, at the different measuring points. In addition, the micro-CT technology seems to be a reliable tool to evaluate the fit of dental restorations.

Polymeric Flexible Immunosensor Based on Piezoresistive Micro-Cantilever with PEDOT/PSS Conductive Layer

Directory of Open Access Journals (Sweden)

Rui Zhao

2018-02-01

Full Text Available In this paper, a fully polymeric micro-cantilever with the surface passivation layer of parylene-C and the strain resistor of poly(3,4-ethylenedioxythiophene/poly (styrene sulfonate (PEDOT/PSS was proposed and demonstrated for immunoassays. By optimizing the design and fabrication of the polymeric micro-cantilever, a square resistance of 220 Ω/□ for PEDOT/PSS conductive layer have been obtained. The experimental spring constant and the deflection sensitivity were measured to be 0.017 N/m and 8.59 × 10−7 nm−1, respectively. The biological sensing performances of polymeric micro-cantilever were investigated by the immunoassay for human immunoglobulin G (IgG. The immunosensor was experimentally demonstrated to have a linear behavior for the detection of IgG within the concentrations of 10~100 ng/mL with a limit of detection (LOD of 10 ng/mL. The experimental results indicate that the proposed polymeric flexible conductive layer-based sensors are capable of detecting trace biological substances.

Applications of a Navigation Instrument Based on a Micro-Motor Driven by Photons

Directory of Open Access Journals (Sweden)

Jorge VALENZUELA

2011-12-01

Full Text Available We report potential applications of a novel design of a micro-motor driven by light. The design, based on a scale of micro-machines fabrication, takes into consideration the concept of radiation pressure as a method of actuation. The micro-motor of diameter 15 mm is designed to be made in Silicon wafer. To decrease the weight of the rotational part, we designed a hollow structure metalized by Aluminum. To reduce friction, we suggest the use of octadecylphosphonic acid (ODPA as Aluminium coating and perfluoropolyoxyalkane (Z-DOL as Silicon coating. The materials selected lower friction by approximately 50 % and increase reflectivity, allowing a better conversion of the radiant energy into movement. Our design targets altimeter and inclinometer as major applications. It is clear that other applications such as measurement of light intensity, identification of wavelength of incident light, measurement of degree of polarization of light and others can be served by this design.

Polymeric Flexible Immunosensor Based on Piezoresistive Micro-Cantilever with PEDOT/PSS Conductive Layer.

Science.gov (United States)

Zhao, Rui; Sun, Ying

2018-02-03

In this paper, a fully polymeric micro-cantilever with the surface passivation layer of parylene-C and the strain resistor of poly(3,4-ethylenedioxythiophene)/poly (styrene sulfonate) (PEDOT/PSS) was proposed and demonstrated for immunoassays. By optimizing the design and fabrication of the polymeric micro-cantilever, a square resistance of 220 Ω/□ for PEDOT/PSS conductive layer have been obtained. The experimental spring constant and the deflection sensitivity were measured to be 0.017 N/m and 8.59 × 10 -7 nm -1 , respectively. The biological sensing performances of polymeric micro-cantilever were investigated by the immunoassay for human immunoglobulin G (IgG). The immunosensor was experimentally demonstrated to have a linear behavior for the detection of IgG within the concentrations of 10~100 ng/mL with a limit of detection (LOD) of 10 ng/mL. The experimental results indicate that the proposed polymeric flexible conductive layer-based sensors are capable of detecting trace biological substances.

Development of a micro-depletion model to us WIMS properties in history-based local-parameter calculations in RFSP

International Nuclear Information System (INIS)

Shen, W.

2004-01-01

A micro-depletion model has been developed and implemented in the *SIMULATE module of RFSP to use WIMS-calculated lattice properties in history-based local-parameter calculations. A comparison between the micro-depletion and WIMS results for each type of lattice cross section and for the infinite-lattice multiplication factor was also performed for a fuel similar to that which may be used in the ACR fuel. The comparison shows that the micro-depletion calculation agrees well with the WIMS-IST calculation. The relative differences in k-infinity are within ±0.5 mk and ±0.9 mk for perturbation and depletion calculations, respectively. The micro-depletion model gives the *SIMULATE module of RFSP the capability to use WIMS-calculated lattice properties in history-based local-parameter calculations without resorting to the Simple-Cell-Methodology (SCM) surrogate for CANDU core-tracking simulations. (author)

Faraday Waves-Based Integrated Ultrasonic Micro-Droplet Generator and Applications.

Science.gov (United States)

Tsai, Chen S; Mao, Rong W; Tsai, Shirley C; Shahverdi, Kaveh; Zhu, Yun; Lin, Shih K; Hsu, Yu-Hsiang; Boss, Gerry; Brenner, Matt; Mahon, Sari; Smaldone, Gerald C

2017-01-01

An in-depth review on a new ultrasonic micro-droplet generator which utilizes megahertz (MHz) Faraday waves excited by silicon-based multiple Fourier horn ultrasonic nozzles (MFHUNs) and its potential applications is presented. The new droplet generator has demonstrated capability for producing micro droplets of controllable size and size distribution and desirable throughput at very low electrical drive power. For comparison, the serious deficiencies of current commercial droplet generators (nebulizers) and the other ultrasonic droplet generators explored in recent years are first discussed. The architecture, working principle, simulation, and design of the multiple Fourier horns (MFH) in resonance aimed at the amplified longitudinal vibration amplitude on the end face of nozzle tip, and the fabrication and characterization of the nozzles are then described in detail. Subsequently, a linear theory on the temporal instability of Faraday waves on a liquid layer resting on the planar end face of the MFHUN and the detailed experimental verifications are presented. The linear theory serves to elucidate the dynamics of droplet ejection from the free liquid surface and predict the vibration amplitude onset threshold for droplet ejection and the droplet diameters. A battery-run pocket-size clogging-free integrated micro droplet generator realized using the MFHUN is then described. The subsequent report on the successful nebulization of a variety of commercial pulmonary medicines against common diseases and on the experimental antidote solutions to cyanide poisoning using the new droplet generator serves to support its imminent application to inhalation drug delivery.

A biodetection method using magnetic particles and micro traps

KAUST Repository

Li, Fuquan

2012-03-09

The general working principle of magnetoresistive sensors for biological applications is to specifically attach bioanalytesto magnetic particles and then detect the particles that are immobilized on the sensor surface. The immobilization of the particles on the sensor surface commonly uses biomolecular interactions, e.g., antigen-antibody. Thus, the sensor surface needs to be functionalized via biological treatments in order to capture certain bioanalytes. In the presented work, a new method is proposed, which does not rely on functionalization of the sensor surface. Current carrying microstructures in combination with mechanical micro traps are used to immobilize magnetic particles. Analyte detection is based on the difference in size between bare magnetic particles and particles with analyte attached, which causes a different number of particles to be captured in the micro traps.

A Comprehensive Strategy for Accurate Reactive Power Distribution, Stability Improvement, and Harmonic Suppression of Multi-Inverter-Based Micro-Grid

Directory of Open Access Journals (Sweden)

Henan Dong

2018-03-01

Full Text Available Among the issues of accurate power distribution, stability improvement, and harmonic suppression in micro-grid, each has been well studied as an individual, and most of the strategies about these issues aim at one inverter-based micro-grid, hence there is a need to establish a model to achieve these functions as a whole, aiming at a multi-inverter-based micro-grid. This paper proposes a comprehensive strategy which achieves this goal successfully; since the output voltage and frequency of micro-grid all consist of fundamental and harmonic components, the strategy contains two parts accordingly. On one hand, a fundamental control strategy is proposed upon the conventional droop control. The virtual impedance is introduced to solve the problem of accurate allocation of reactive power between inverters. Meanwhile, a secondary power balance controller is added to improve the stability of voltage and frequency while considering the aggravating problem of stability because of introducing virtual impedance. On the other hand, the fractional frequency harmonic control strategy is proposed. It can solve the influence of nonlinear loads, micro-grid inverters, and the distribution network on output voltage of inverters, which is focused on eliminating specific harmonics caused by the nonlinear loads, micro-grid converters, and the distribution network so that the power quality of micro-grid can be improved effectively. Finally, small signal analysis is used to analyze the stability of the multi-converter parallel system after introducing the whole control strategy. The simulation results show that the strategy proposed in this paper has a great performance on distributing reactive power, regulating and stabilizing output voltage of inverters and frequency, eliminating harmonic components, and improving the power quality of multi-inverter-based micro-grid.

Successful subretinal delivery and monitoring of MicroBeads in mice.

Directory of Open Access Journals (Sweden)

M Dominik Fischer

Full Text Available To monitor viability of implanted genetically engineered and microencapsulated human stem cells (MicroBeads in the mouse eye, and to study the impact of the beads and/or xenogenic cells on retinal integrity.MicroBeads were implanted into the subretinal space of SV126 wild type mice using an ab externo approach. Viability of microencapsulated cells was monitored by noninvasive retinal imaging (Spectralis™ HRA+OCT. Retinal integrity was also assessed with retinal imaging and upon the end of the study by light and electron microscopy. The implanted GFP-marked cells encapsulated in subretinal MicroBeads remained viable over a period of up to 4 months. Retinal integrity and viability appeared unaltered apart from the focal damage due to the surgical implantation, GFAP upregulation, and opsin mistargeting in the immediate surrounding tissue.The accessibility for routine surgery and its immune privileged state make the eye an ideal target for release system implants for therapeutic substances, including neurotrophic and anti-angiogenic compounds or protein based biosimilars. Microencapsulated human stem cells (MicroBeads promise to overcome limitations inherent with single factor release systems, as they are able to produce physiologic combinations of bioactive compounds.

The design of multi-channel pulse amplitude analyzer based on ARM micro controller

International Nuclear Information System (INIS)

Li Hai; Li Xiang; Liu Caixue

2010-01-01

It introduces the design of multi-channel pulse amplitude analyzer based on embedded ARM micro-controller. The embedded and real-time system μC/OS-II builds up the real-time and stability of the system and advances the integration. (authors)

Micro-Inspector Spacecraft for Space Exploration Missions

Science.gov (United States)

Mueller, Juergen; Alkalai, Leon; Lewis, Carol

2005-01-01

NASA is seeking to embark on a new set of human and robotic exploration missions back to the Moon, to Mars, and destinations beyond. Key strategic technical challenges will need to be addressed to realize this new vision for space exploration, including improvements in safety and reliability to improve robustness of space operations. Under sponsorship by NASA's Exploration Systems Mission, the Jet Propulsion Laboratory (JPL), together with its partners in government (NASA Johnson Space Center) and industry (Boeing, Vacco Industries, Ashwin-Ushas Inc.) is developing an ultra-low mass (missions. The micro-inspector will provide remote vehicle inspections to ensure safety and reliability, or to provide monitoring of in-space assembly. The micro-inspector spacecraft represents an inherently modular system addition that can improve safety and support multiple host vehicles in multiple applications. On human missions, it may help extend the reach of human explorers, decreasing human EVA time to reduce mission cost and risk. The micro-inspector development is the continuation of an effort begun under NASA's Office of Aerospace Technology Enabling Concepts and Technology (ECT) program. The micro-inspector uses miniaturized celestial sensors; relies on a combination of solar power and batteries (allowing for unlimited operation in the sun and up to 4 hours in the shade); utilizes a low-pressure, low-leakage liquid butane propellant system for added safety; and includes multi-functional structure for high system-level integration and miniaturization. Versions of this system to be designed and developed under the H&RT program will include additional capabilities for on-board, vision-based navigation, spacecraft inspection, and collision avoidance, and will be demonstrated in a ground-based, space-related environment. These features make the micro-inspector design unique in its ability to serve crewed as well as robotic spacecraft, well beyond Earth-orbit and into arenas such

Grid-connected Photovoltaic Micro-inverter with New Hybrid Control LLC Resonant Converter

DEFF Research Database (Denmark)

Xingkui, Mao; Qisheng, Huang; Qingbo, Ke

2016-01-01

A high-efficiency photovoltaic (PV) micro-inverter consisting of two power stages i.e. a LLC resonant converter with a new hybrid control scheme and a dc-ac inverter is proposed, studied and designed in this paper. In the first power stage, the new hybrid control combining pulse-frequency modulat......A high-efficiency photovoltaic (PV) micro-inverter consisting of two power stages i.e. a LLC resonant converter with a new hybrid control scheme and a dc-ac inverter is proposed, studied and designed in this paper. In the first power stage, the new hybrid control combining pulse......-frequency modulation (PFM) and phase-shift pulse-width modulation (PS-PWM) is employed on a full-bridge LLC dc-dc converter, in order to achieve high efficiency when PV output voltage varies in a wide range. Moreover, a maximum power point tracking (MPPT) method based on power perturbation is implemented in the dc...

MEMS Tunneling Micro Thermometer Based onTip Deflection of Bimetallic Cantilever Beam

Directory of Open Access Journals (Sweden)

Samrand K. Nezhadian

2007-10-01

Full Text Available Micro-electro-mechanical (MEM technology promises to significantly reduce the size, weight and cost of a variety of sensor systems. In this article has been described a highly sensitive novel type of thermometer based on deflection of a “bimetallic” microbeam. The proposed thermometer converts the thermal changes of a cantilevered bimetallic beam of submillimeter size into an electrical signal through tunneling-current modulation. The governing thermo-mechanical equation of a bimetallic cantilever beam has been derived and solved analytically. The obtained results show that the proposed tunneling micro thermometer is very sensitive to temperature changes due to exponential increasing of tunneling current but because of small gap between metallic electrodes, measurable range of temperature changes is small.

Behavior’s Evolution of Micro-Concretes in Combined Sulphate and Magnesium Aggressive Environments, at Three -Years Old

Directory of Open Access Journals (Sweden)

Mircea Rujanu

2010-03-01

Full Text Available In the present paper is analysed concrete behavior from strength structure elements, subjected to combined sulphatic and magnesian aggressive actions. In order to clearly relieve cement influence regarding corrosion behavior and to be as close as possible of concrete structural characteristics, tests are realized on standard mortars, which from compositional point of view are mocro-concretes. These were used different W/C ratios in order to obtain different structural characteristics, knowing that in the first period after casting, when concrete porosity is sensibly higher, corrosion process is more emphatic, with subsequent negative effects. It was taken into account the fact that sulphatic corrosion effect appears after a long duration of aggressive agent action, in the present paper proposing a three year duration for aggressive attack. In the same time it was considered the fact that usual cement for structural elements is composite cement type CEM II/A-S 32,5, studying combined sulphatic and magnesian corrosion evolution on a large type of micro-concrete compositions with different compactness and aggressive agent concentrations.

Astronomical Research with the MicroObservatory Net

Science.gov (United States)

Brecher, K.; Sadler, P.; Gould, R.; Leiker, S.; Antonucci, P.; Deutsch, F.

1997-05-01

We have developed a fully integrated automated astronomical telescope system which combines the imaging power of a cooled CCD, with a self-contained and weatherized 15 cm reflecting optical telescope and mount. The MicroObservatory Net consists of five of these telescopes. They are currently being deployed around the world at widely distributed longitudes. Remote access to the MicroObservatories over the Internet has now been implemented. Software for computer control, pointing, focusing, filter selection as well as pattern recognition have all been developed as part of the project. The telescopes can be controlled in real time or in delay mode, from a Macintosh, PC or other computer using Web-based software. The Internet address of the telescopes is http://cfa- www.harvard.edu/cfa/sed/MicroObservatory/MicroObservatory.html. In the real-time mode, individuals have access to all of the telescope control functions without the need for an `on-site' operator. Users can sign up for a specific period of ti me. In the batch mode, users can submit requests for delayed telescope observations. After a MicroObservatory completes a job, the user is automatically notified by e-mail that the image is available for viewing and downloading from the Web site. The telescopes were designed for classroom instruction, as well as for use by students and amateur astronomers for original scientific research projects. We are currently examining a variety of technical and educational questions about the use of the telescopes including: (1) What are the best approaches to scheduling real-time versus batch mode observations? (2) What criteria should be used for allocating telescope time? (3) With deployment of more than one telescope, is it advantageous for each telescope to be used for just one type of observation, i.e., some for photometric use, others for imaging? And (4) What are the most valuable applications of the MicroObservatories in astronomical research? Support for the Micro

The MicroObservatory Net

Science.gov (United States)

Brecher, K.; Sadler, P.

1994-12-01

A group of scientists, engineers and educators based at the Harvard-Smithsonian Center for Astrophysics (CfA) has developed a prototype of a small, inexpensive and fully integrated automated astronomical telescope and image processing system. The project team is now building five second generation instruments. The MicroObservatory has been designed to be used for classroom instruction by teachers as well as for original scientific research projects by students. Probably in no other area of frontier science is it possible for a broad spectrum of students (not just the gifted) to have access to state-of-the-art technologies that would allow for original research. The MicroObservatory combines the imaging power of a cooled CCD, with a self contained and weatherized reflecting optical telescope and mount. A microcomputer points the telescope and processes the captured images. The MicroObservatory has also been designed to be used as a valuable new capture and display device for real time astronomical imaging in planetariums and science museums. When the new instruments are completed in the next few months, they will be tried with high school students and teachers, as well as with museum groups. We are now planning to make the MicroObservatories available to students, teachers and other individual users over the Internet. We plan to allow the telescope to be controlled in real time or in batch mode, from a Macintosh or PC compatible computer. In the real-time mode, we hope to give individual access to all of the telescope control functions without the need for an "on-site" operator. Users would sign up for a specific period of time. In the batch mode, users would submit jobs for the telescope. After the MicroObservatory completed a specific job, the images would be e-mailed back to the user. At present, we are interested in gaining answers to the following questions: (1) What are the best approaches to scheduling real-time observations? (2) What criteria should be used

Axis-switching of a micro-jet

Science.gov (United States)

Cabaleiro, Juan Martin; Aider, Jean-Luc

2014-03-01

In this study, it is shown that free microjets can undergo complex transitions similar to large-scale free jets despite relatively low Reynolds numbers. Using an original experimental method allowing for the 3D reconstruction of the instantaneous spatial organization of the microjet, the axis-switching of a micro-jet is observed for the first time. This is the first experimental evidence of such complex phenomena for free micro-jets. Combining these experimental results with Direct Numerical Simulations it is shown that the mechanism responsible for the axis-switching is the deformation of a micro-vortex ring due to induction by the corner vortices, as it occurs in large scale non-circular jets.

Application of micro-computed tomography to microstructure studies of the medicinal fungus Hericium coralloides.

Science.gov (United States)

Pallua, Johannes D; Kuhn, Volker; Pallua, Anton F; Pfaller, Kristian; Pallua, Anton K; Recheis, Wolfgang; Pöder, Reinhold

2015-01-01

The potential of 3-D nondestructive imaging techniques such as micro-computed tomography (micro-CT) was evaluated to study morphological patterns of the potential medicinal fungus Hericium coralloides (Basidiomycota). Micro-CT results were correlated with histological information gained from scanning electron microscopy (SEM) and light microscopy (LM). It is demonstrated that the combination of these imaging methods results in a more distinct picture of the morphology of the edible and potentially medicinal Hericium coralloides basidiomata. In addition we have created 3-D reconstructions and visualizations based on micro-CT imagery from a randomly selected part of the upper region of a fresh H. coralloides basidioma: Analyses for the first time allowed an approximation of the evolutionary effectiveness of this bizarrely formed basidioma type in terms of the investment of tissue biomass and its reproductive output (production of basidiospores). © 2015 by The Mycological Society of America.

The Laser MicroJet (LMJ): a multi-solution technology for high quality micro-machining

Science.gov (United States)

Mai, Tuan Anh; Richerzhagen, Bernold; Snowdon, Paul C.; Wood, David; Maropoulos, Paul G.

2007-02-01

The field of laser micromachining is highly diverse. There are many different types of lasers available in the market. Due to their differences in irradiating wavelength, output power and pulse characteristic they can be selected for different applications depending on material and feature size [1]. The main issues by using these lasers are heat damages, contamination and low ablation rates. This report examines on the application of the Laser MicroJet(R) (LMJ), a unique combination of a laser beam with a hair-thin water jet as a universal tool for micro-machining of MEMS substrates, as well as ferrous and non-ferrous materials. The materials include gallium arsenide (GaAs) & silicon wafers, steel, tantalum and alumina ceramic. A Nd:YAG laser operating at 1064 nm (infra red) and frequency doubled 532 nm (green) were employed for the micro-machining of these materials.

Laser 3D micro-manufacturing

International Nuclear Information System (INIS)

Piqué, Alberto; Auyeung, Raymond C Y; Kim, Heungsoo; Charipar, Nicholas A; Mathews, Scott A

2016-01-01

Laser-based materials processing techniques are gaining widespread use in micro-manufacturing applications. The use of laser microfabrication techniques enables the processing of micro- and nanostructures from a wide range of materials and geometries without the need for masking and etching steps commonly associated with photolithography. This review aims to describe the broad applications space covered by laser-based micro- and nanoprocessing techniques and the benefits offered by the use of lasers in micro-manufacturing processes. Given their non-lithographic nature, these processes are also referred to as laser direct-write and constitute some of the earliest demonstrations of 3D printing or additive manufacturing at the microscale. As this review will show, the use of lasers enables precise control of the various types of processing steps—from subtractive to additive—over a wide range of scales with an extensive materials palette. Overall, laser-based direct-write techniques offer multiple modes of operation including the removal (via ablative processes) and addition (via photopolymerization or printing) of most classes of materials using the same equipment in many cases. The versatility provided by these multi-function, multi-material and multi-scale laser micro-manufacturing processes cannot be matched by photolithography nor with other direct-write microfabrication techniques and offer unique opportunities for current and future 3D micro-manufacturing applications. (topical review)

Hollow micro string based calorimeter device

DEFF Research Database (Denmark)

2014-01-01

positions so as to form a free released double clamped string in-between said two longitudinally distanced positions said micro-channel string comprising a microfluidic channel having a closed cross section and extending in the longitudinal direction of the hollow string, acoustical means adapted...

Micro CT based truth estimation of nodule volume

Science.gov (United States)

Kinnard, L. M.; Gavrielides, M. A.; Myers, K. J.; Zeng, R.; Whiting, B.; Lin-Gibson, S.; Petrick, N.

2010-03-01

With the advent of high-resolution CT, three-dimensional (3D) methods for nodule volumetry have been introduced, with the hope that such methods will be more accurate and consistent than currently used planar measures of size. However, the error associated with volume estimation methods still needs to be quantified. Volume estimation error is multi-faceted in the sense that there is variability associated with the patient, the software tool and the CT system. A primary goal of our current research efforts is to quantify the various sources of measurement error and, when possible, minimize their effects. In order to assess the bias of an estimate, the actual value, or "truth," must be known. In this work we investigate the reliability of micro CT to determine the "true" volume of synthetic nodules. The advantage of micro CT over other truthing methods is that it can provide both absolute volume and shape information in a single measurement. In the current study we compare micro CT volume truth to weight-density truth for spherical, elliptical, spiculated and lobulated nodules with diameters from 5 to 40 mm, and densities of -630 and +100 HU. The percent differences between micro CT and weight-density volume for -630 HU nodules range from [-21.7%, -0.6%] (mean= -11.9%) and the differences for +100 HU nodules range from [-0.9%, 3.0%] (mean=1.7%).

Towards the effective tool wear control in micro-EDM milling

DEFF Research Database (Denmark)

Bissacco, Giuliano; Valentincic, J.; Hansen, Hans Nørgaard

2010-01-01

The electrode wear in micro-electrical discharge milling (micro-EDM milling) is one of the main problems to be solved in order to improve machining accuracy. This paper presents an investigation on wear and material removal in micro-EDM milling for selected process parameter combinations typical...... of the accuracy of volume measurements on the electrode wear per discharge and on the material removal per discharge are discussed, and the issues limiting the applicability of real time wear sensing in micro-EDM milling are presented....

Design of a holographic micro-scale spectrum-splitting photovoltaic system

Science.gov (United States)

Wu, Yuechen; Vorndran, Shelby; Ayala Pelaez, Silvana; Russo, Juan M.; Kostuk, Raymond K.

2015-09-01

Micro-scale PV technology combines the high conversion efficiency of concentrated photovoltaics (CPV) with the low costs and the simple form of flat panel PV. Some of the benefits of micro-scale PV include: reduced semiconductor material usage; improved heat rejection capacity; and more versatile PV cell interconnect configurations. Spectrumsplitting is also a beneficial technique to increase the efficiency and reduce the cost of photovoltaic systems. It spatially separates the incident solar spectrum into spectral components and directs them to PV cells with matching bandgaps. This approach avoids the current and lattice matching problems that exist in tandem multi-junction systems. In this paper, we applied the ideas of spectrum-splitting in a micro-scale PV system, and demonstrated a holographic micro-scale spectrum-splitting photovoltaic system. This system consists of a volume transmission hologram in combination with a micro-lens array. An analysis methodology was developed to design the system and determine the performance of the resulting system. The spatial characteristics of the dispersed spectrum, the overall system conversion efficiency, and the improvement over best bandgap will be discussed.

Regions of micro-calcifications clusters detection based on new features from imbalance data in mammograms

Science.gov (United States)

Wang, Keju; Dong, Min; Yang, Zhen; Guo, Yanan; Ma, Yide

2017-02-01

Breast cancer is the most common cancer among women. Micro-calcification cluster on X-ray mammogram is one of the most important abnormalities, and it is effective for early cancer detection. Surrounding Region Dependence Method (SRDM), a statistical texture analysis method is applied for detecting Regions of Interest (ROIs) containing microcalcifications. Inspired by the SRDM, we present a method that extract gray and other features which are effective to predict the positive and negative regions of micro-calcifications clusters in mammogram. By constructing a set of artificial images only containing micro-calcifications, we locate the suspicious pixels of calcifications of a SRDM matrix in original image map. Features are extracted based on these pixels for imbalance date and then the repeated random subsampling method and Random Forest (RF) classifier are used for classification. True Positive (TP) rate and False Positive (FP) can reflect how the result will be. The TP rate is 90% and FP rate is 88.8% when the threshold q is 10. We draw the Receiver Operating Characteristic (ROC) curve and the Area Under the ROC Curve (AUC) value reaches 0.9224. The experiment indicates that our method is effective. A novel regions of micro-calcifications clusters detection method is developed, which is based on new features for imbalance data in mammography, and it can be considered to help improving the accuracy of computer aided diagnosis breast cancer.

Rectenna session: Micro aspects. [energy conversion

Science.gov (United States)

Gutmann, R. J.

1980-01-01

Two micro aspects of the rectenna design are addressed: evaluation of the degradation in net rectenna RF to DC conversion efficiency due to power density variations across the rectenna (power combining analysis) and design of Yagi-Uda receiving elements to reduce rectenna cost by decreasing the number of conversion circuits (directional receiving elements). The first of these micro aspects involves resolving a fundamental question of efficiency potential with a rectenna, while the second involves a design modification with a large potential cost saving.

Precise deformation measurement of prestressed concrete beam during a strain test using the combination of intersection photogrammetry and micro-network measurement

Science.gov (United States)

Urban, Rudolf; Braun, Jaroslav; Štroner, Martin

2015-05-01

The prestressed thin-walled concrete elements enable the bridge a relatively large span. These structures are advantageous in economic and environmental way due to their thickness and lower consumption of materials. The bending moments can be effectively influenced by using the pre-stress. The experiment was done to monitor deformation of the under load. During the experiment the discrete points were monitored. To determine a large number of points, the intersection photogrammetry combined with precise micro-network were chosen. Keywords:

Availability of Micro-Tom mutant library combined with TILLING in molecular breeding of tomato fruit shelf-life.

Science.gov (United States)

Okabe, Yoshihiro; Asamizu, Erika; Ariizumi, Tohru; Shirasawa, Kenta; Tabata, Satoshi; Ezura, Hiroshi

2012-06-01

Novel mutant alleles of an ethylene receptor Solanum lycopersicum ETHYLENE RESPONSE1 (SlETR1) gene, Sletr1-1 and Sletr1-2, were isolated from the Micro-Tom mutant library by TILLING in our previous study. They displayed different levels of impaired fruit ripening phenotype, suggesting that these alleles could be a valuable breeding material for improving shelf life of tomato fruit. To conduct practical use of the Sletr1 alleles in tomato breeding, genetic complementation analysis by transformation of genes carrying each allele is required. In this study, we generated and characterized transgenic lines over-expressing Sletr1-1 and Sletr1-2. All transgenic lines displayed ethylene insensitive phenotype and ripening inhibition, indicating that Sletr1-1 and Sletr1-2 associate with the ethylene insensitive phenotype. The level of ethylene sensitivity in the seedling was different between Sletr1-1 and Sletr1-2 transgenic lines, whereas no apparent difference was observed in fruit ripening phenotype. These results suggested that it is difficult to fine-tune the extent of ripening by transgenic approach even if the weaker allele (Sletr1-2) was used. Our present and previous studies indicate that the Micro-Tom mutant library combined with TILLING could be an efficient tool for exploring genetic variations of important agronomic traits in tomato breeding.

Availability of Micro-Tom mutant library combined with TILLING in molecular breeding of tomato fruit shelf-life

Science.gov (United States)

Okabe, Yoshihiro; Asamizu, Erika; Ariizumi, Tohru; Shirasawa, Kenta; Tabata, Satoshi; Ezura, Hiroshi

2012-01-01

Novel mutant alleles of an ethylene receptor Solanum lycopersicum ETHYLENE RESPONSE1 (SlETR1) gene, Sletr1-1 and Sletr1-2, were isolated from the Micro-Tom mutant library by TILLING in our previous study. They displayed different levels of impaired fruit ripening phenotype, suggesting that these alleles could be a valuable breeding material for improving shelf life of tomato fruit. To conduct practical use of the Sletr1 alleles in tomato breeding, genetic complementation analysis by transformation of genes carrying each allele is required. In this study, we generated and characterized transgenic lines over-expressing Sletr1-1 and Sletr1-2. All transgenic lines displayed ethylene insensitive phenotype and ripening inhibition, indicating that Sletr1-1 and Sletr1-2 associate with the ethylene insensitive phenotype. The level of ethylene sensitivity in the seedling was different between Sletr1-1 and Sletr1-2 transgenic lines, whereas no apparent difference was observed in fruit ripening phenotype. These results suggested that it is difficult to fine-tune the extent of ripening by transgenic approach even if the weaker allele (Sletr1-2) was used. Our present and previous studies indicate that the Micro-Tom mutant library combined with TILLING could be an efficient tool for exploring genetic variations of important agronomic traits in tomato breeding. PMID:23136532

Barbed micro-spikes for micro-scale biopsy

Science.gov (United States)

Byun, Sangwon; Lim, Jung-Min; Paik, Seung-Joon; Lee, Ahra; Koo, Kyo-in; Park, Sunkil; Park, Jaehong; Choi, Byoung-Doo; Seo, Jong Mo; Kim, Kyung-ah; Chung, Hum; Song, Si Young; Jeon, Doyoung; Cho, Dongil

2005-06-01

Single-crystal silicon planar micro-spikes with protruding barbs are developed for micro-scale biopsy and the feasibility of using the micro-spike as a micro-scale biopsy tool is evaluated for the first time. The fabrication process utilizes a deep silicon etch to define the micro-spike outline, resulting in protruding barbs of various shapes. Shanks of the fabricated micro-spikes are 3 mm long, 100 µm thick and 250 µm wide. Barbs protruding from micro-spike shanks facilitate the biopsy procedure by tearing off and retaining samples from target tissues. Micro-spikes with barbs successfully extracted tissue samples from the small intestines of the anesthetized pig, whereas micro-spikes without barbs failed to obtain a biopsy sample. Parylene coating can be applied to improve the biocompatibility of the micro-spike without deteriorating the biopsy function of the micro-spike. In addition, to show that the biopsy with the micro-spike can be applied to tissue analysis, samples obtained by micro-spikes were examined using immunofluorescent staining. Nuclei and F-actin of cells which are extracted by the micro-spike from a transwell were clearly visualized by immunofluorescent staining.

Micro-hole array fluorescent sensor based on AC-Dielectrophoresis (DEP) for simultaneous analysis of nano-molecules

Science.gov (United States)

Kim, Hye Jin; Kang, Dong-Hoon; Lee, Eunji; Hwang, Kyo Seon; Shin, Hyun-Joon; Kim, Jinsik

2018-02-01

We propose a simple fluorescent bio-chip based on two types of alternative current-dielectrophoretic (AC-DEP) force, attractive (positive DEP) and repulsive (negative DEP) force, for simultaneous nano-molecules analysis. Various radius of micro-holes on the bio-chip are designed to apply the different AC-DEP forces, and the nano-molecules are concentrated inside the micro-hole arrays according to the intensity of the DEP force. The bio-chip was fabricated by Micro Electro Mechanical system (MEMS) technique, and was composed of two layers; a SiO2 layer and Ta/Pt layer were accomplished for an insulation layer and a top electrode with micro-hole arrays to apply electric fields for DEP force, respectively. Each SiO2 and Ta/Pt layers were deposited by thermal oxidation and sputtering, and micro-hole arrays were fabricated with Inductively Coupled Plasma (ICP) etching process. For generation of each positive and negative DEP at micro-holes, we applied two types of sine-wave AC voltage with different frequency range alternately. The intensity of the DEP force was controlled by the radius of the micro-hole and size of nano-molecule, and calculated with COMSOL multi-physics. Three types of nano-molecules labelled with different fluorescent dye were used and the intensity of nano-molecules was examined by the fluorescent optical analysis after applying the DEP force. By analyzing the fluorescent intensities of the nano-molecules, we verify the various nano-molecules in analyte are located successfully inside corresponding micro-holes with different radius according to their size.

18F-FET microPET and microMRI for anti-VEGF and anti-PlGF response assessment in an orthotopic murine model of human glioblastoma

DEFF Research Database (Denmark)

Nedergaard, Mette Kjoelhede; Michaelsen, Signe Regner; Urup, Thomas

2015-01-01

BACKGROUND: Conflicting data exist for anti-cancer effects of anti-placental growth factor (anti-PlGF) in combination with anti-VEGF. Still, this treatment combination has not been evaluated in intracranial glioblastoma (GBM) xenografts. In clinical studies, position emission tomography (PET) using......-FET MicroPET and MicroMRI for evaluation of anti-VEGF and anti-PlGF treatment response in GBM xenografts. METHODS: Mice with intracranial GBM were treated with anti-VEGF, anti-PlGF + anti-VEGF or saline. Bioluminescence imaging (BLI), 18F-FET MicroPET and T2-weighted (T2w)-MRI were used to follow tumour...... development. Primary end-point was survival, and tumours were subsequently analysed for Ki67 proliferation index and micro-vessel density (MVD). Further, PlGF and VEGFR-1 expression were examined in a subset of the xenograft tumours and in 13 GBM patient tumours. RESULTS: Anti-VEGF monotherapy increased...

Phase behaviour and microstructure of the micro-emulsions composed of cholinium-based ionic liquid, Triton X-100 and water

International Nuclear Information System (INIS)

Pei, Yuanchao; Huang, Yanjie; Li, Lin; Wang, Jianji

2014-01-01

Highlights: • The microemulsions composed of cholinium-based ionic liquid, Triton X-100 and water have been prepared and characterised. • Ternary phase diagrams of the microemulsions have been established at T = 298.15 K. • The microemulsions exhibit IL-in-water, bicontinuous and water-in-IL microstructures. • Droplets with the size smaller than 20 nm are formed in these IL-based microemulsions. - Abstract: In this paper, micro-emulsions composed of cholinium-based ionic liquids (ILs), octylphenol ethoxylate (Triton X-100) and water were prepared. These ternary systems were found to be stable over 12 months at room temperature. Their phase behaviour was investigated by using cloud titrations, and their microstructures were characterised by means of cyclic voltammetry and electrical conductance measurements at T = 298.15 K. It was shown that the micro-emulsions exhibited IL-in-water, bi-continuous and water-in-IL microstructures. Dynamic light scattering data suggest that Triton X-100 forms micelles in water, which were swelled by the ILs added. Droplets with the size about 20 nm were formed in these IL-based micro-emulsions, and the droplet size increased with the increase of the IL concentrations. These IL-based micro-emulsions may have potential in drug delivery, chemical reactions and nanomaterial preparation as a new type of nanoreactors

Analysis of micro vibration in gas film of aerostatic guide way based on molecule collision theory

Directory of Open Access Journals (Sweden)

Yang Shao Hua

2016-01-01

Full Text Available Micro vibration of the aerostatic guide way has a significant impact on its dynamic characteristics and stability, which limits the development of pneumatic component. High pressure gas molecules have been collided with the supporting surface and the internal surface of the throttle during the flow process. Variable impulse of the surfaces aside for the gas film are affected by the changes of impulse which formed irregular impact force in horizontal and vertical direction. Micro-vibration takes place based on the natural frequency of the system and its frequency doubling. In this paper, the vibration model was established to describe the dynamic characteristics of the gas film, and the formation mechanism of micro vibration in the film is defined. Through the simulation analysis and experimental comparison, formation mechanism of the micro vibration in the gas film is confirmed. It was proposed that the micro vibration of gas film can be produced no matter whether there is a gas chamber or not in the throttle. Under the same conditions, the micro vibration of the guide way with air chamber is greater than that without any chamber. The frequency points of the vibration peaks are almost the same, as well as the vibration pattern in the frequency domain.

Evaluation of the adaptation of zirconia-based fixed partial dentures using micro-CT technology

Energy Technology Data Exchange (ETDEWEB)

Borba, Marcia; Bona, Alvaro Della, E-mail: marcia_borb@hotmail.com [Universidade de Passo Fundo (UPF), RS (Brazil). Fac. de Odontologia; Miranda Junior, Walter Gomes; Cesar, Paulo Francisco [Universidade de Sao Paulo (USP), SP (Brazil). Fac. de Odontologia. Dept. de Biomateriais e Bioquimica Oral; Griggs, Jason Allan [Department of Biomedical Materials Science, Dental School, University of Mississippi Medical Center - UMMC, Jackson, MS (United States)

2013-09-15

The objective of the study was to measure the marginal and internal fit of zirconia-based all-ceramic three-unit fixed partial dentures (FPDs) (Y-TZP - LAVA, 3M-ESPE), using a novel methodology based on micro-computed tomography (micro-CT) technology. Stainless steel models of prepared abutments were fabricated to design FPDs. Ten frameworks were produced with 9 mm² connector cross-sections using a LAVA® CAD-CAM system. All FPDs were veneered with a compatible porcelain. Each FPD was seated on the original model and scanned using micro-CT. Files were processed using NRecon and CTAn software. Adobe Photoshop and Image J software were used to analyze the cross sectional images. Five measuring points were selected, as follows: MG- marginal gap; CA - chamfer area; AW - axial wall; AOT - axio-occlusal transition area; OA - occlusal area. Results were statistically analyzed by Kruskall-Wallis and Tukey's post hoc test (α = 0.05). There were significant differences for the gap width between the measurement points evaluated. MG showed the smallest median gap width (42 μm). OA had the highest median gap dimension (125 μm), followed by the AOT point (105 μm). CA and AW gap width values were statistically similar, 66 and 65 μm respectively. Thus, it was possible to conclude that different levels of adaptation were observed within the FPD, at the different measuring points. In addition, the micro-CT technology seems to be a reliable tool to evaluate the fit of dental restorations. (author)

Evaluation of the adaptation of zirconia-based fixed partial dentures using micro-CT technology

International Nuclear Information System (INIS)

Borba, Marcia; Bona, Alvaro Della

2013-01-01

The objective of the study was to measure the marginal and internal fit of zirconia-based all-ceramic three-unit fixed partial dentures (FPDs) (Y-TZP - LAVA, 3M-ESPE), using a novel methodology based on micro-computed tomography (micro-CT) technology. Stainless steel models of prepared abutments were fabricated to design FPDs. Ten frameworks were produced with 9 mm² connector cross-sections using a LAVA® CAD-CAM system. All FPDs were veneered with a compatible porcelain. Each FPD was seated on the original model and scanned using micro-CT. Files were processed using NRecon and CTAn software. Adobe Photoshop and Image J software were used to analyze the cross sectional images. Five measuring points were selected, as follows: MG- marginal gap; CA - chamfer area; AW - axial wall; AOT - axio-occlusal transition area; OA - occlusal area. Results were statistically analyzed by Kruskall-Wallis and Tukey's post hoc test (α = 0.05). There were significant differences for the gap width between the measurement points evaluated. MG showed the smallest median gap width (42 μm). OA had the highest median gap dimension (125 μm), followed by the AOT point (105 μm). CA and AW gap width values were statistically similar, 66 and 65 μm respectively. Thus, it was possible to conclude that different levels of adaptation were observed within the FPD, at the different measuring points. In addition, the micro-CT technology seems to be a reliable tool to evaluate the fit of dental restorations. (author)

Compact high-efficiency vortex beam emitter based on a silicon photonics micro-ring

DEFF Research Database (Denmark)

Li, Shimao; Ding, Yunhong; Guan, Xiaowei

2018-01-01

Photonic integrated devices that emit vortex beam carrying orbital angular momentum are becoming key components for multiple applications. Here we propose and demonstrate a high-efficiency vortex beam emitter based on a silicon micro-ring resonator integrated with a metal mirror. Such a compact...

[Researches on biomechanics of micro-implant-bone interface and optimum design of micro implant's neck].

Science.gov (United States)

Deng, Feng; Zhang, Lei; Zhang, Yi; Song, Jin-lin; Fan, Yuboa

2007-07-01

To compare and analyze the stress distribution at the micro-implant-bone interface based on the different micro-implant-bone conditioned under orthodontic load, and to optimize the design of micro implant's neck. An adult skull with all tooth was scanned by spiral CT, and the data were imported into computer for three-dimensional reconstruction with software Mimics 9.0. The three dimensional finite element models of three micro-implant-bone interfaces(initial stability, full osseointegration and fibrous integration) were analyzed by finite element analysis software ABAQUS6.5. The primary stress distributions of different micro-implant-bone conditions were evaluated when 2N force was loaded. Then the diameter less than 1.5 mm of the micro implant's neck was added with 0.2 mm, to compare the stress distribution of the modified micro-implant-bone interface with traditional type. The stress mostly concentrated on the neck of micro implant and the full osseointegration interface in all models showed the lowest strain level. Compared with the traditional type, the increasing diameter neck of the micro implant obviously decreased the stress level in all the three conditions. The micro-implant-bone interface and the diameter of micro implant's neck both are the important influence factors to the stress distribution of micro implant.

On the performance of micro injection moulding process simulations of TPE micro rings

DEFF Research Database (Denmark)

Baruffi, Federico; Calaon, Matteo; Tosello, Guido

, a case study based on the micro injection moulding process of thermoplastic elastomer (TPE) micro rings (volume: 1.5 mm3, mass: 2.2 mg) for sensors application is treated. Injection moulding process simulations using Autodesk Moldflow Insight 2016® were applied with the aim of accomplishing two main...

Numerical study of a hybrid jet impingement/micro-channel cooling scheme

International Nuclear Information System (INIS)

Barrau, Jérôme; Omri, Mohammed; Chemisana, Daniel; Rosell, Joan; Ibañez, Manel; Tadrist, Lounes

2012-01-01

A new hybrid jet impingement/micro-channel cooling scheme is studied numerically for use in high-heat-flux thermal management of electronic and power devices. The device is developed with the objective of improving the temperature uniformity of the cooled object. A numerical model based on the k–ω SST turbulent model is developed and validated experimentally. This model is used to carry out a parametrical characterization of the heat sink. The study shows that variations in key parameters of jet impingement and micro-channel technologies allow for the cooling scheme to obtain a wide range of temperature profiles for the cooled object. - Highlights: ► A new hybrid cooling scheme is numerically studied. ► The cooling scheme combines the benefits of jet impingement and micro-channel flows. ► The numerical model is validated by comparison with experimental results. ► The temperature distribution can be adapted to the needs of the cooled system.

Predicting the drying shrinkage behavior of high strength portland cement mortar under the combined influence of fine aggregate and steel micro fiber

International Nuclear Information System (INIS)

Li, Zhengqi

2017-01-01

The workability, 28-day compressive strength and free drying shrinkage of a very high strength (121-142 MPa) steel micro fiber reinforced portland cement mortar were studied under a combined influence of fine aggregate content and fiber content. The test results showed that an increase in the fine aggregate content resulted in decreases in the workability, 28-day compressive strength and drying shrinkage of mortar at a fixed fiber content. An increase in the fiber content resulted in decreases in the workability and drying shrinkage of mortar, but an increase in the 28-day compressive strength of mortar at a fixed fine aggregate content. The modified Gardner model most accurately predicted the drying shrinkage development of the high strength mortars, followed by the Ross model and the ACI 209R-92 model. The Gardner model gave the least accurate prediction for it was developed based on a database of normal strength concrete. [es

Predicting the drying shrinkage behavior of high strength portland cement mortar under the combined influence of fine aggregate and steel micro fiber

Directory of Open Access Journals (Sweden)

Zhengqi Li

2017-03-01

Full Text Available The workability, 28-day compressive strength and free drying shrinkage of a very high strength (121-142 MPa steel micro fiber reinforced portland cement mortar were studied under a combined influence of fine aggregate content and fiber content. The test results showed that an increase in the fine aggregate content resulted in decreases in the workability, 28-day compressive strength and drying shrinkage of mortar at a fixed fiber content. An increase in the fiber content resulted in decreases in the workability and drying shrinkage of mortar, but an increase in the 28-day compressive strength of mortar at a fixed fine aggregate content. The modified Gardner model most accurately predicted the drying shrinkage development of the high strength mortars, followed by the Ross model and the ACI 209R-92 model. The Gardner model gave the least accurate prediction for it was developed based on a database of normal strength concrete.

Faraday Waves-Based Integrated Ultrasonic Micro-Droplet Generator and Applications

Directory of Open Access Journals (Sweden)

Chen S. Tsai

2017-02-01

Full Text Available An in-depth review on a new ultrasonic micro-droplet generator which utilizes megahertz (MHz Faraday waves excited by silicon-based multiple Fourier horn ultrasonic nozzles (MFHUNs and its potential applications is presented. The new droplet generator has demonstrated capability for producing micro droplets of controllable size and size distribution and desirable throughput at very low electrical drive power. For comparison, the serious deficiencies of current commercial droplet generators (nebulizers and the other ultrasonic droplet generators explored in recent years are first discussed. The architecture, working principle, simulation, and design of the multiple Fourier horns (MFH in resonance aimed at the amplified longitudinal vibration amplitude on the end face of nozzle tip, and the fabrication and characterization of the nozzles are then described in detail. Subsequently, a linear theory on the temporal instability of Faraday waves on a liquid layer resting on the planar end face of the MFHUN and the detailed experimental verifications are presented. The linear theory serves to elucidate the dynamics of droplet ejection from the free liquid surface and predict the vibration amplitude onset threshold for droplet ejection and the droplet diameters. A battery-run pocket-size clogging-free integrated micro droplet generator realized using the MFHUN is then described. The subsequent report on the successful nebulization of a variety of commercial pulmonary medicines against common diseases and on the experimental antidote solutions to cyanide poisoning using the new droplet generator serves to support its imminent application to inhalation drug delivery.

Simultaneous removal and evaluation of organic substrates and NH3-N by a novel combined process in treating chemical synthesis-based pharmaceutical wastewater

International Nuclear Information System (INIS)

Chen, Zhaobo; Wang, Hongcheng; Ren, Nanqi; Cui, Minhua; Nie, Shukai; Hu, Dongxue

2011-01-01

Highlights: ► We research a novel combined process to treat chemical synthesis-based pharmaceutical wastewater. ► The mechanism of amoxicillin verifies that the biodegradation, adsorption, hydrolysis and unknown mechanism were able to remove amoxicillin from wastewater. ► In this study demonstrates that biodegradation is the major factor for removal mechanism at work for amoxicillin. ► Mathematical statistic methods were employed to evaluate the performance of the WWTP. - Abstract: A full-scale novel combined anaerobic/micro-aerobic and two-stage aerobic biological process is used for the treatment of an actual chemical synthesis-based pharmaceutical wastewater containing amoxicillin. The anaerobic system is an up-flow anaerobic sludge blanket (UASB), the micro-aerobic system is a novel micro-aerobic hydrolysis acidification reactor (NHAR) and the two-stage aerobic process comprised cyclic activated sludge system (CASS) and biological contact oxidation tank (BCOT). The influent wastewater was high in COD, NH 3 -N varying daily 4016–13,093 mg-COD L −1 and 156.4–650.2 mg-NH 3 -N L −1 , amoxicillin varying weekly between 69.1 and 105.4 mg-amoxicillin L −1 , respectively; Almost all the COD, NH 3 -N, amoxicillin were removed by the biological combined system, with removal percentages 97%, 93.4% and 97.2%, respectively, leaving around 104 mg-COD L −1 , 9.4 mg-NH 3 -N L −1 and 2.6 ± 0.8 mg-amoxicillin L −1 in the final clarifier effluent. The performance evaluation of the wastewater treatment plant (WWTP) by mathematical statistic methods shown that at most of time effluent can meet the higher treatment discharge standard. In addition, the fate of amoxicillin in the full-scale WWTP and the amoxicillin removal rate of each different removal routes in UASB, NHAR, CASS, BCOT and final clarifier processes are investigated in this paper. The results show that biodegradation, adsorption and hydrolysis are the major mechanisms for amoxicillin removal.

Intelligent Operation and Maintenance of Micro-grid Technology and System Development

Science.gov (United States)

Fu, Ming; Song, Jinyan; Zhao, Jingtao; Du, Jian

2018-01-01

In order to achieve the micro-grid operation and management, Studying the micro-grid operation and maintenance knowledge base. Based on the advanced Petri net theory, the fault diagnosis model of micro-grid is established, and the intelligent diagnosis and analysis method of micro-grid fault is put forward. Based on the technology, the functional system and architecture of the intelligent operation and maintenance system of micro-grid are studied, and the microcomputer fault diagnosis function is introduced in detail. Finally, the system is deployed based on the micro-grid of a park, and the micro-grid fault diagnosis and analysis is carried out based on the micro-grid operation. The system operation and maintenance function interface is displayed, which verifies the correctness and reliability of the system.

Search for Bs0 --> micro+ micro- and B0 --> micro+ micro- decays with 2 fb-1 of pp collisions.

Science.gov (United States)

Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Bednar, P; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'orso, M; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Genser, K; Gerberich, H; Gerdes, D; Giagu, S; Giakoumopolou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Koay, S A; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lu, R-S; Lucchesi, D; Lueck, J; Luci, C; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyria, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner-Kuhr, J; Wagner, W; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zheng, Y; Zucchelli, S

2008-03-14

We have performed a search for B(s)(0) --> micro(+) micro(-) and B(0) --> micro(+) micro(-) decays in pp collisions at square root s = 1.96 TeV using 2 fb(-1) of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron Collider. The observed number of B(s)(0) and B0 candidates is consistent with background expectations. The resulting upper limits on the branching fractions are B(B(s)0) --> micro(+) micro(-)) micro(+) micro(-))<1.8 x 10(-8) at 95% C.L.

Micro Resistojet for Small Satellites, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Micro-resistojets offer the best combination of simplicity, performance, wet system mass and power consumption for small satellites (<100kg, <50Watts)...

Measurement of triboelectric charging of moving micro particles by means of an inductive cylindrical probe

International Nuclear Information System (INIS)

Nesterov, A; Loeffler, F; Koenig, K; Trunk, U; Leibe, K; Felgenhauer, T; Bischoff, F R; Breitling, F; Lindenstruth, V; Stadler, V; Hausmann, M

2007-01-01

We present a method based on induced currents in a cylindrical probe which allows analysis of the micro-particle charging processes in an aerosol. The micro particles were triboelectrically charged by passing through a dielectric tube coaxially mounted into the probe. The cylindrical probe enabled the quantification of particle charging without prior calibration of the probe. An analytic model was developed for the description of the measured induced currents and implemented into a computer simulation program. The combination of model simulations and an appropriate experimental setup revealed comprehensive data for the determination of the particles' electric charge against time of flight through the tube. In methodological proof of principle experiments, the formations of particle clouds with charges of different signs were observed using magnetite micro particles

Demoulding force in micro-injection moulding

DEFF Research Database (Denmark)

Griffiths, C.A.; Dimov, S.S.; Scholz, S.

2012-01-01

The paper reports an experimental study that investigates part demoulding behavior in micro injection moulding (MIM) with a focus on the effects of pressure (P) and temperature (T) on the demoulding forces. Demoulding of a microfluidics part is conducted and the four processing parameters of melt...... temperature (Tb), mould temperature (Tm), holding pressure (Ph) and injection speed (Vi) are analysed. The result using different combinations of process parameters were used to identify the best processing conditions in regards to demoulding forces when moulding micro parts....

Hybrid cycles for micro generation

International Nuclear Information System (INIS)

Campanari, S.

2000-01-01

This paper deals with the main features of two emerging technologies in the field of small-scale power generation, micro turbines and Solid Oxide Fuel Cells, discussing the extremely high potential of their combination into hybrid cycles and their possible role for distributed cogeneration [it

Micro-foundations for macroeconomics: New set-up based on statistical physics

Science.gov (United States)

Yoshikawa, Hiroshi

2016-12-01

Modern macroeconomics is built on "micro foundations." Namely, optimization of micro agent such as consumer and firm is explicitly analyzed in model. Toward this goal, standard model presumes "the representative" consumer/firm, and analyzes its behavior in detail. However, the macroeconomy consists of 107 consumers and 106 firms. For the purpose of analyzing such macro system, it is meaningless to pursue the micro behavior in detail. In this respect, there is no essential difference between economics and physics. The method of statistical physics can be usefully applied to the macroeconomy, and provides Keynesian economics with correct micro-foundations.

Design challenges for stepper motor actuated microvalve based on fine and micro-machining

NARCIS (Netherlands)

Fazal, I.; Elwenspoek, Michael Curt

2007-01-01

We present a normally open stepper motor actuated microvalve based on micro and fine-machining technique. In this paper, first we have described how the larger controllable flow range can be achieved with simple micromachining techniques and secondly we have presented the results which show how the

A method of measuring micro-impulse with torsion pendulum based on multi-beam laser heterodyne

Science.gov (United States)

Li, Yan-Chao; Wang, Chun-Hui

2012-02-01

In this paper, we propose a novel method of multi-beam laser heterodyne measurement for micro-impulse. The measurement of the micro-impulse, which is converted into the measurement of the small tuning angle of the torsion pendulum, is realized by considering the interaction between pulse laser and working medium. Based on Doppler effect and heterodyne technology, the information regarding the small tuning angle is loaded to the frequency difference of the multi-beam laser heterodyne signal by the frequency modulation of the oscillating mirror, thereby obtaining many values of the small tuning angle after the multi-beam laser heterodyne signal demodulation simultaneously. Processing these values by weighted-average, the small tuning angle can be obtained accurately and the value of the micro-impulse can eventually be calculated. Using Polyvinylchlorid+2%C as a working medium, this novel method is used to simulate the value of the micro-impulse by MATLAB which is generated by considering the interaction between the pulse laser and the working medium, the obtained result shows that the relative error of this method is just 0.5%.

A method of measuring micro-impulse with torsion pendulum based on multi-beam laser heterodyne

International Nuclear Information System (INIS)

Li Yan-Chao; Wang Chun-Hui

2012-01-01

In this paper, we propose a novel method of multi-beam laser heterodyne measurement for micro-impulse. The measurement of the micro-impulse, which is converted into the measurement of the small tuning angle of the torsion pendulum, is realized by considering the interaction between pulse laser and working medium. Based on Doppler effect and heterodyne technology, the information regarding the small tuning angle is loaded to the frequency difference of the multi-beam laser heterodyne signal by the frequency modulation of the oscillating mirror, thereby obtaining many values of the small tuning angle after the multi-beam laser heterodyne signal demodulation simultaneously. Processing these values by weighted-average, the small tuning angle can be obtained accurately and the value of the micro-impulse can eventually be calculated. Using Polyvinylchlorid+2%C as a working medium, this novel method is used to simulate the value of the micro-impulse by MATLAB which is generated by considering the interaction between the pulse laser and the working medium, the obtained result shows that the relative error of this method is just 0.5%. (general)

Design and simulation of GaN based Schottky betavoltaic nuclear micro-battery

International Nuclear Information System (INIS)

San, Haisheng; Yao, Shulin; Wang, Xiang; Cheng, Zaijun; Chen, Xuyuan

2013-01-01

The current paper presents a theoretical analysis of Ni-63 nuclear micro-battery based on a wide-band gap semiconductor GaN thin-film covered with thin Ni/Au films to form Schottky barrier for carrier separation. The total energy deposition in GaN was calculated using Monte Carlo methods by taking into account the full beta spectral energy, which provided an optimal design on Schottky barrier width. The calculated results show that an 8 μm thick Schottky barrier can collect about 95% of the incident beta particle energy. Considering the actual limitations of current GaN growth technique, a Fe-doped compensation technique by MOCVD method can be used to realize the n-type GaN with a carrier concentration of 1×10 15 cm −3 , by which a GaN based Schottky betavoltaic micro-battery can achieve an energy conversion efficiency of 2.25% based on the theoretical calculations of semiconductor device physics. - Highlights: • Ni-63 is employed as the pure beta radioisotope source. • The Schottky junction betavoltaic battery is based on the wide-band gap semiconductor GaN. • The total energy deposition of incident beta particles in GaN was simulated by the Monte Carlo method. • A Fe-doped compensation technique is suggested to increase the energy conversion efficiency

Dewetting based fabrication of fibrous micro-scaffolds as potential injectable cell carriers.

Science.gov (United States)

Song, Hokyung; Yin, Liya; Chilian, William M; Zhang Newby, Bi-Min

2015-03-01

Although regenerative medicine utilizing tissue scaffolds has made enormous strides in recent years, many constraints still hamper their effectiveness. A limitation of many scaffolds is that they form surface patches, which are not particularly effective for some types of "wounds" that are deep within tissues, e.g., stroke and myocardial infarction. In this study, we reported the generation of fibrous micro-scaffolds feasible for delivering cells by injection into the tissue parenchyma. The micro-scaffolds (widthsdewetting of poly(lactic-co-glycolic acid) thin films containing parallel strips, and cells were seeded to form cell/polymer micro-constructs during or post the micro-scaffold fabrication process. Five types of cells including rat induced vascular progenitor cells were assessed for the formation of the micro-constructs. Critical factors in forming fibrous micro-scaffolds via dewetting of polymer thin films were found to be properties of polymers and supporting substrates, temperature, and proteins in the culture medium. Also, the ability of cells to attach to the micro-scaffolds was essential in forming cell/polymer micro-constructs. Both in vitro and in vivo assessments of injecting these micro-scaffolding constructs showed, as compared to free cells, enhanced cell retention at the injected site, which could lead to improved tissue engineering and regeneration. Copyright © 2014 Elsevier B.V. All rights reserved.

MicroED data collection and processing

Energy Technology Data Exchange (ETDEWEB)

Hattne, Johan; Reyes, Francis E.; Nannenga, Brent L.; Shi, Dan; Cruz, M. Jason de la [Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147 (United States); Leslie, Andrew G. W. [Medical Research Council Laboratory of Molecular Biology, Cambridge (United Kingdom); Gonen, Tamir, E-mail: gonent@janelia.hhmi.org [Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147 (United States)

2015-07-01

The collection and processing of MicroED data are presented. MicroED, a method at the intersection of X-ray crystallography and electron cryo-microscopy, has rapidly progressed by exploiting advances in both fields and has already been successfully employed to determine the atomic structures of several proteins from sub-micron-sized, three-dimensional crystals. A major limiting factor in X-ray crystallography is the requirement for large and well ordered crystals. By permitting electron diffraction patterns to be collected from much smaller crystals, or even single well ordered domains of large crystals composed of several small mosaic blocks, MicroED has the potential to overcome the limiting size requirement and enable structural studies on difficult-to-crystallize samples. This communication details the steps for sample preparation, data collection and reduction necessary to obtain refined, high-resolution, three-dimensional models by MicroED, and presents some of its unique challenges.

Micro-propulsion and micro-combustion; Micropropulsion microcombustion

Energy Technology Data Exchange (ETDEWEB)

Ribaud, Y.; Dessornes, O.

2002-10-01

The AAAF (french space and aeronautic association) organized at Paris a presentation on the micro-propulsion. The first part was devoted to the thermal micro-machines for micro drones, the second part to the micro-combustion applied to micro-turbines. (A.L.B.)

Ternary chalcogenide micro-pseudocapacitors for on-chip energy storage

KAUST Repository

Kurra, Narendra

2015-05-11

We report the successful fabrication of a micro-pseudocapacitor based on ternary nickel cobalt sulfide for the first time, with performance substantially exceeding that of previously reported micro-pseudocapacitors based on binary sulfides. CoNi2S4 micro-pseudocapacitor exhibits a maximum energy density of 18.7 mWh/cm3 at a power density of 1163 mW/cm3, opens up an avenue for exploring new family of ternary oxides/sulfides based micro-pseudocapacitors.

Ternary chalcogenide micro-pseudocapacitors for on-chip energy storage

KAUST Repository

Kurra, Narendra; Xia, Chuan; Hedhili, Mohamed N.; Alshareef, Husam N.

2015-01-01

We report the successful fabrication of a micro-pseudocapacitor based on ternary nickel cobalt sulfide for the first time, with performance substantially exceeding that of previously reported micro-pseudocapacitors based on binary sulfides. CoNi2S4 micro-pseudocapacitor exhibits a maximum energy density of 18.7 mWh/cm3 at a power density of 1163 mW/cm3, opens up an avenue for exploring new family of ternary oxides/sulfides based micro-pseudocapacitors.

Cone-shaped membrane liquid phase micro extraction

International Nuclear Information System (INIS)

Hong, Heng See; Sanagi, M.M.; Ibrahim, W.A.W.; Naim, A.A.

2008-01-01

A novel sample pre-treatment technique termed cone-shaped membrane liquid phase micro extraction (CSM-LPME) was developed and combined with micro-liquid chromatography (micro-LC) for the determination of selected pesticides in water samples. Several important extraction parameters such as types of extraction solvent, agitation rate, pH value, total exposure time and effect of salt and humic acids were investigated and optimized. Enrichment factors of >50 folds were easily achieved within 20 min of extraction. The new developed method demonstrated an excellent performance in terms of speed, cost effectiveness, reproducibility, as well as exceptional low detection limits. Current work provides a great interest to further investigate on the applicability of the CSM-LPME technique in analytical chemistry and explores the possibility of replacing conventional extraction techniques such as soxhlet, solid phase extraction (SPE) and solid phase micro extraction (SPME). (author)

Combined amplification and hybridization techniques for genome scanning in vegetatively propagated crops

International Nuclear Information System (INIS)

Kahl, G.; Ramser, J.; Terauchi, R.; Lopez-Peralta, C.; Asemota, H.N.; Weising, K.

1998-01-01

A combination of PCR- and hybridization-based genome scanning techniques and sequence comparisons between non-coding chloroplast DNA flanking tRNA genes has been employed to screen Dioscorea species for intra- and interspecific genetic diversity. This methodology detected extensive polymorphisms within Dioscorea bulbifera L., and revealed taxonomic and phylogenetic relationships among cultivated Guinea yams varieties and their potential wild progenitors. Finally, screening of yam germplasm grown in Jamaica permitted reliable discrimination between all major cultivars. Genome scanning by micro satellite-primed PCR (MP-PCR) and random amplified polymorphic DNA (RAPD) analysis in combination with the novel random amplified micro satellite polymorphisms (RAMPO) hybridization technique has shown high potential for the genetic analysis of yams, and holds promise for other vegetatively propagated orphan crops. (author)

Micro Resistojet for Small Satellites, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Micro-resistojets offer an excellent combination of simplicity, performance and wet system mass for small satellites (<100 kg, <50 watts) requiring mN level...

Selective micro metallization of polymers for biomedical and medical application

DEFF Research Database (Denmark)

Islam, Mohammad Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

Integration of micro/nano metallic structures in polymer devices is a broad multi-disciplinary research field, consisting of various combinations of mechanical, chemical and physical fabrication methods. Some of these combinations have been known for years and other combinations or methods are ve...

Modeling of various contact theories for the manipulation of different biological micro/nanoparticles based on AFM

Science.gov (United States)

Korayem, M. H.; Taheri, M.

2014-01-01

In this article, the modeling of various contact theories to be applied in the biomanipulation of different micro/nanoparticles based on the atomic force microscope has been studied, and the effect of adhesion force in different contact models on indentation depth and contact angle between tip and substrate has been explored for the target biological micro/nanoparticle. The contact models used in this research include the Hertz, JKR, DMT, BCP, COS, PT, and the SUN models. Also, the target particles comprise the biological micro/nanoparticles of DNA, yeast, platelet, and nanobacterium. Previous research works have investigated the contact models for the manipulation of non-biological gold micro/nanoparticles in the air environment. Since in a real biomanipulation situation, the biological micro/nanoparticles are displaced in biological environments; in this article, various contact theories for the biomanipulation of biological micro/nanoparticles in different biological environments have been modeled and compared for the first time. The results of modeling indicate that the use of Hertz contact model in analyzing the biomanipulation of biological nanoparticles is not appropriate, because it does not take the adhesion force into consideration and thus produces a significant error. Also, all the six contact models developed in this article show larger deformations for studied bionanoparticles in comparison to the gold nanoparticles, which can be justified with regards to the mechanical properties of gold.

Micro Electro Discharge Machining of Electrically Nonconductive Ceramics

International Nuclear Information System (INIS)

Schubert, A.; Zeidler, H.; Hackert, M.; Wolf, N.

2011-01-01

EDM is a known process for machining of hard and brittle materials. Due to its noncontact and nearly forceless behaviour, it has been introduced into micro manufacturing and through constant development it is now an important means for producing high-precision micro geometries. One restriction of EDM is its limitation to electrically conducting materials.Today many applications, especially in the biomedical field, make use of the benefits of ceramic materials, such as high strength, very low wear and biocompatibility. Common ceramic materials such as Zirconium dioxide are, due to their hardness in the sintered state, difficult to machine with conventional cutting techniques. A demand for the introduction of EDM to these materials could so far not be satisfied because of their nonconductive nature.At the Chemnitz University of Technology and the Fraunhofer IWU, investigations in the applicability of micro-EDM for the machining of nonconductive ceramics are being conducted. Tests are undertaken using micro-EDM drilling with Tungsten carbide tool electrodes and ZrO 2 ceramic workpieces. A starting layer, in literature often referred to as 'assisting electrode' is used to set up a closed electric circuit to start the EDM process. Combining carbon hydride based dielectric and a specially designed low-frequency vibration setup to excite the workpiece, the process environment can be held within parameters to allow for a constant EDM process even after the starting layer is machined. In the experiments a cylindrical 120 μm diameter Tungsten carbide tool electrode and Y 2 O 3 - and MgO- stabilized ZrO 2 worpieces are used. The current and voltage signals of the discharges within the different stages of the process (machining of the starting layer, machining of the base material, transition stage) are recorded and their characteristics compared to discharges in metallic material. Additionally, the electrode feed is monitored. The influences of the process parameters are

On-chip micro-power: three-dimensional structures for micro-batteries and micro-supercapacitors

Science.gov (United States)

Beidaghi, Majid; Wang, Chunlei

2010-04-01

With the miniaturization of portable electronic devices, there is a demand for micro-power source which can be integrated on the semiconductor chips. Various micro-batteries have been developed in recent years to generate or store the energy that is needed by microsystems. Micro-supercapacitors are also developed recently to couple with microbatteries and energy harvesting microsystems and provide the peak power. Increasing the capacity per footprint area of micro-batteries and micro-supercapacitors is a great challenge. One promising route is the manufacturing of three dimensional (3D) structures for these micro-devices. In this paper, the recent advances in fabrication of 3D structure for micro-batteries and micro-supercapacitors are briefly reviewed.

Is micro-CHP price controllable under price signal controlled Virtual Power Plants?

DEFF Research Database (Denmark)

You, Shi; Træholt, Chresten; Poulsen, Bjarne

2011-01-01

As micro-combined heat and power (micro-CHP) systems move towards mass deployment together with other kinds of distributed energy resources (DER), an increasing emphasis has been placed on how to coordinate such a large diversified DER portfolio in an efficient way by the Virtual Power Plant (VPP...... for three different micro-CHP systems to investigate the feasibility of being controlled by price. Such analysis is relevant for both controller designs for micro-CHP systems and VPP related operations. The results indicate that controlling the micro-CHP systems by price is feasible but could result...

Analysis of fixed tilt and sun tracking photovoltaic–micro wind based hybrid power systems

International Nuclear Information System (INIS)

Sinha, Sunanda; Chandel, S.S.

2016-01-01

Graphical abstract: 6 kW_p photovoltaic–micro wind based hybrid power system analysis in a Indian Western Himalayan location. - Highlights: • Power generation by a roof mounted photovoltaic–micro wind hybrid system is explored. • Optimum hybrid configurations using fixed and sun tracking photovoltaic systems are determined. • Analysis of hybrid systems with optimally tilted and different sun tracking systems is presented. • Two axis sun tracking systems are found to generate 4.88–26.29% more energy than fixed tilt system. • Hybrid system installed at optimum tilt angle is found to be cost effective than a sun tracking system. - Abstract: In this study fixed tilt and sun tracking photovoltaic based micro wind hybrid power systems are analyzed along with determining the optimum configurations for a 6 kW_p roof mounted micro wind based hybrid system using fixed and tracking photovoltaic systems to enhance the power generation potential in a low windy Indian hilly terrain with good solar resource. The main objective of the study is to enhance power generation by focusing on photovoltaic component of the hybrid system. A comparative power generation analysis of different configurations of hybrid systems with fixed tilt, monthly optimum tilt, yearly optimum tilt and 6 different sun tracking photovoltaic systems is carried out using Hybrid Optimization Model for Electric Renewables. Monthly and seasonal optimum tilt angles determined for the location vary between 0° and 60° with annual optimum tilt angle as 29.25°. The optimum configurations for all sun tracking systems except for the two axis tracking system is found to be 7 kW_p photovoltaic system, one 5 kW_p wind turbine, 10 batteries and a 2 kW_p inverter. The optimum configuration for two axis tracking system and two types of fixed tilt systems, is found to be a 8 kW_p photovoltaic system, one 5 kW_p wind turbine, 10 batteries and a 2 kW_p inverter. The results show that horizontal axis with

Biologically Inspired Micro-Flight Research

Science.gov (United States)

Raney, David L.; Waszak, Martin R.

2003-01-01

Natural fliers demonstrate a diverse array of flight capabilities, many of which are poorly understood. NASA has established a research project to explore and exploit flight technologies inspired by biological systems. One part of this project focuses on dynamic modeling and control of micro aerial vehicles that incorporate flexible wing structures inspired by natural fliers such as insects, hummingbirds and bats. With a vast number of potential civil and military applications, micro aerial vehicles represent an emerging sector of the aerospace market. This paper describes an ongoing research activity in which mechanization and control concepts for biologically inspired micro aerial vehicles are being explored. Research activities focusing on a flexible fixed- wing micro aerial vehicle design and a flapping-based micro aerial vehicle concept are presented.

Micro-resonators based on integrated polymer technology for optical sensing

Science.gov (United States)

Girault, Pauline; Lemaitre, Jonathan; Guendouz, Mohammed; Lorrain, Nathalie; Poffo, Luiz; Gadonna, Michel; Bosc, Dominique

2014-05-01

Research on sensors has experienced a noticeable development over the last decades especially in label free optical biosensors. However, compact sensors without markers for rapid, reliable and inexpensive detection of various substances induce a significant research of new technological solutions. The context of this work is the development of a sensor based on easily integrated and inexpensive micro-resonator (MR) component in integrated optics, highly sensitive and selective mainly in the areas of health and food. In this work, we take advantage of our previous studies on filters based on micro-resonators (MR) to experiment a new couple of polymers in the objective to use MR as a sensing function. MRs have been fabricated by processing SU8 polymer as core and PMATRIFE polymer as cladding layer of the waveguide. The refractive index contrast reaches 0.16 @ 1550 nm. Sub-micronic ring waveguides gaps from 0.5 to 1 μm have been successfully achieved with UV (i-line) photolithography. This work confirms our forecasts, published earlier, about the resolution that can be achieved. First results show a good extinction coefficient of ~17 dB, a quality factor around 104 and a finesse of 12. These results are in concordance with the theoretical study and they allow us to validate our technology with this couple of polymers. Work is going on with others lower cladding materials that will be used to further increase refractive index contrast for sensing applications.

Simultaneous acquisition of 3D shape and deformation by combination of interferometric and correlation-based laser speckle metrology.

Science.gov (United States)

Dekiff, Markus; Berssenbrügge, Philipp; Kemper, Björn; Denz, Cornelia; Dirksen, Dieter

2015-12-01

A metrology system combining three laser speckle measurement techniques for simultaneous determination of 3D shape and micro- and macroscopic deformations is presented. While microscopic deformations are determined by a combination of Digital Holographic Interferometry (DHI) and Digital Speckle Photography (DSP), macroscopic 3D shape, position and deformation are retrieved by photogrammetry based on digital image correlation of a projected laser speckle pattern. The photogrammetrically obtained data extend the measurement range of the DHI-DSP system and also increase the accuracy of the calculation of the sensitivity vector. Furthermore, a precise assignment of microscopic displacements to the object's macroscopic shape for enhanced visualization is achieved. The approach allows for fast measurements with a simple setup. Key parameters of the system are optimized, and its precision and measurement range are demonstrated. As application examples, the deformation of a mandible model and the shrinkage of dental impression material are measured.

Microscope self-calibration based on micro laser line imaging and soft computing algorithms

Science.gov (United States)

Apolinar Muñoz Rodríguez, J.

2018-06-01

A technique to perform microscope self-calibration via micro laser line and soft computing algorithms is presented. In this technique, the microscope vision parameters are computed by means of soft computing algorithms based on laser line projection. To implement the self-calibration, a microscope vision system is constructed by means of a CCD camera and a 38 μm laser line. From this arrangement, the microscope vision parameters are represented via Bezier approximation networks, which are accomplished through the laser line position. In this procedure, a genetic algorithm determines the microscope vision parameters by means of laser line imaging. Also, the approximation networks compute the three-dimensional vision by means of the laser line position. Additionally, the soft computing algorithms re-calibrate the vision parameters when the microscope vision system is modified during the vision task. The proposed self-calibration improves accuracy of the traditional microscope calibration, which is accomplished via external references to the microscope system. The capability of the self-calibration based on soft computing algorithms is determined by means of the calibration accuracy and the micro-scale measurement error. This contribution is corroborated by an evaluation based on the accuracy of the traditional microscope calibration.

Simultaneous removal and evaluation of organic substrates and NH{sub 3}-N by a novel combined process in treating chemical synthesis-based pharmaceutical wastewater

Energy Technology Data Exchange (ETDEWEB)

Chen, Zhaobo [School of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Wang, Hongcheng [School of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Ren, Nanqi, E-mail: rnq@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Cui, Minhua; Nie, Shukai; Hu, Dongxue [School of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China)

2011-12-15

Highlights: Black-Right-Pointing-Pointer We research a novel combined process to treat chemical synthesis-based pharmaceutical wastewater. Black-Right-Pointing-Pointer The mechanism of amoxicillin verifies that the biodegradation, adsorption, hydrolysis and unknown mechanism were able to remove amoxicillin from wastewater. Black-Right-Pointing-Pointer In this study demonstrates that biodegradation is the major factor for removal mechanism at work for amoxicillin. Black-Right-Pointing-Pointer Mathematical statistic methods were employed to evaluate the performance of the WWTP. - Abstract: A full-scale novel combined anaerobic/micro-aerobic and two-stage aerobic biological process is used for the treatment of an actual chemical synthesis-based pharmaceutical wastewater containing amoxicillin. The anaerobic system is an up-flow anaerobic sludge blanket (UASB), the micro-aerobic system is a novel micro-aerobic hydrolysis acidification reactor (NHAR) and the two-stage aerobic process comprised cyclic activated sludge system (CASS) and biological contact oxidation tank (BCOT). The influent wastewater was high in COD, NH{sub 3}-N varying daily 4016-13,093 mg-COD L{sup -1} and 156.4-650.2 mg-NH{sub 3}-N L{sup -1}, amoxicillin varying weekly between 69.1 and 105.4 mg-amoxicillin L{sup -1}, respectively; Almost all the COD, NH{sub 3}-N, amoxicillin were removed by the biological combined system, with removal percentages 97%, 93.4% and 97.2%, respectively, leaving around 104 mg-COD L{sup -1}, 9.4 mg-NH{sub 3}-N L{sup -1} and 2.6 {+-} 0.8 mg-amoxicillin L{sup -1} in the final clarifier effluent. The performance evaluation of the wastewater treatment plant (WWTP) by mathematical statistic methods shown that at most of time effluent can meet the higher treatment discharge standard. In addition, the fate of amoxicillin in the full-scale WWTP and the amoxicillin removal rate of each different removal routes in UASB, NHAR, CASS, BCOT and final clarifier processes are investigated

Combination Effect of Hemostatic and Disinfecting Agents on Micro-leakage of Restorations Bonded with Different Bonding Systems

Directory of Open Access Journals (Sweden)

Farhadpour H

2016-09-01

Full Text Available Statement of Problem: Hemostatic agents may affect the micro-leakage of different adhesive systems. Also, chlorhexidine has shown positive effects on micro-leakage. However, their interaction effect has not been reported yet. Objectives: To evaluate the effect of contamination with a hemostatic agent on micro- leakage of total- and self-etching adhesive systems and the effect of chlorhexidine application after the removal of the hemostatic agent. Materials and Methods: Standardized Class V cavity was prepared on each of the sixty caries free premolars at the cemento-enamel junction, with the occlusal margin located in enamel and the gingival margin in dentin. Then, the specimens were randomly divided into 6 groups (n = 10 according to hemostatic agent (H contamination, chlorhexidine (CHX application, and the type of adhesive systems (Adper Single Bond and Clearfil SE Bond used. After filling the cavities with resin composite, the root apices were sealed with utility wax. Furthermore, all the surfaces, except for the restorations and 1mm from the margins, were covered with two layers of nail varnish. The teeth were immersed in a 0.5% basic fuschin dye for 24 hours, rinsed, blot-dried and sectioned longitudinally through the center of the restorations bucco- lingualy. The sections were examined using a stereomicroscope and the extension of dye penetration was analyzed according to a non-parametric scale from 0 to 3. Statistical analysis was performed using Kruskal-Wallis test and Mann-Whitney U-test. Results: While ASB group showed no micro-leakage in enamel, none of the groups showed complete elimination of micro-leakage from the dentin. Regarding micro- leakage at enamel, and dentin margins, there was no significant difference between groups 1 and 2, 1 and 3, and 2 and 3 (p > 0.05. A significantly lower micro-leakage at the enamel and dentin margins was observed in group 3, compared to group 6. No significant difference was observed between

Low-power-consumption and high-sensitivity NO2 micro gas sensors based on a co-planar micro-heater fabricated by using a CMOS-MEMS process

International Nuclear Information System (INIS)

Moon, S. E.; Lee, J. W.; Park, S. J.; Park, J.; Park, K. H.; Kim, J.

2010-01-01

Small-scale, low-power-consumption, and high-sensitivity NO 2 gas sensors based on ZnO nanorods are reported in this work. To activate the chemical absorption and desorption for NO 2 gas, we embedded co-planar micro-heater in a micro gas sensor, that was made by using a Complementary Metal-oxide-semiconductor compatible Microelectromechanical Systems(CMOS-MEMS) process. To acquire simple fabrication and low fabrication cost, we located the micro-heater and the sensing electrode in the same plane. High-quality single-crystalline ZnO nanorods were selectively grown by using photolithography and a hydrothermal method. Their structural properties were confirmed by using X-ray diffractometry (XRD), energy dispersive X-ray spectroscopy microanalysis (EDAX), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The temperature-dependent current-voltage characteristics were measured to optimize the operating temperature of the fabricated devices as a chemical gas sensor. To test the possibility for use as chemical sensor, we measured the NO 2 gas response.

Homogenization-based topology optimization for high-resolution manufacturable micro-structures

DEFF Research Database (Denmark)

Groen, Jeroen Peter; Sigmund, Ole

2018-01-01

This paper presents a projection method to obtain high-resolution, manufacturable structures from efficient and coarse-scale, homogenization-based topology optimization results. The presented approach bridges coarse and fine scale, such that the complex periodic micro-structures can be represented...... by a smooth and continuous lattice on the fine mesh. A heuristic methodology allows control of the projected topology, such that a minimum length-scale on both solid and void features is ensured in the final result. Numerical examples show excellent behavior of the method, where performances of the projected...

Micro- and nano-scale characterization to study the thermal degradation of cement-based materials

International Nuclear Information System (INIS)

Lim, Seungmin; Mondal, Paramita

2014-01-01

The degradation of hydration products of cement is known to cause changes in the micro- and nano-structure, which ultimately drive thermo-mechanical degradation of cement-based composite materials at elevated temperatures. However, a detailed characterization of these changes is still incomplete. This paper presents results of an extensive experimental study carried out to investigate micro- and nano-structural changes that occur due to exposure of cement paste to high temperatures. Following heat treatment of cement paste up to 1000 °C, damage states were studied by compressive strength test, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) atomic force microscopy (AFM) and AFM image analysis. Using experimental results and research from existing literature, new degradation processes that drive the loss of mechanical properties of cement paste are proposed. The development of micro-cracks at the interface between unhydrated cement particles and paste matrix, a change in C–S–H nano-structure and shrinkage of C–S–H, are considered as important factors that cause the thermal degradation of cement paste. - Highlights: • The thermal degradation of hydration products of cement is characterized at micro- and nano-scale using scanning electron microscopy (SEM) and atomic force microscopy (AFM). • The interface between unhydrated cement particles and the paste matrix is considered the origin of micro-cracks. • When cement paste is exposed to temperatures above 300 ºC, the nano-structure of C-S-H becomes a more loosely packed globular structure, which could be indicative of C-S-H shrinkage

Evaluation of Fine Aggregate Morphology by Image Method and Its Effect on Skid-Resistance of Micro-Surfacing.

Science.gov (United States)

Xiao, Yue; Wang, Feng; Cui, Peide; Lei, Lei; Lin, Juntao; Yi, Mingwei

2018-05-29

Micro-surfacing is a widely used pavement preventive maintenance technology used all over the world, due to its advantages of fast construction, low maintenance cost, good waterproofness, and skid-resistance performance. This study evaluated the fine aggregate morphology and surface texture of micro-surfacing by AIMS (aggregate image measurement system), and explored the effect of aggregate morphology on skid-resistance of single-grade micro-surfacing. Sand patch test and British pendulum test were also used to detect skid-resistance for comparison with the image-based method. Wet abrasion test was used to measure skid-resistance durability for feasibility verification of single-grade micro-surfacing. The results show that the effect of Form2D on the skid-resistance of micro-surfacing is much stronger than that of angularity. Combining the feasibility analysis of durability and skid-resistance, 1.18⁻2.36 grade micro-surfacing meets the requirements of durability and skid-resistance at the same time. This study also determined that, compared with British pendulum test, the texture result obtained by sand patch test fits better with results of image method.

A comparison of reflectance properties on polymer micro-structured functional surface

DEFF Research Database (Denmark)

Regi, Francesco; Li, Dongya; Nielsen, Jannik Boll

In this study, a functional micro-structure surface [1] has been developed as a combination of arrays of micro ridges. The scope of the surface is to achieve specific directional optical properties: that is, under constrained lighting, maximizing the reflectance from a certain viewing direction, ...

Sustainable Micro-Manufacturing of Micro-Components via Micro Electrical Discharge Machining

Directory of Open Access Journals (Sweden)

Valeria Marrocco

2011-12-01

Full Text Available Micro-manufacturing emerged in the last years as a new engineering area with the potential of increasing peoples’ quality of life through the production of innovative micro-devices to be used, for example, in the biomedical, micro-electronics or telecommunication sectors. The possibility to decrease the energy consumption makes the micro-manufacturing extremely appealing in terms of environmental protection. However, despite this common belief that the micro-scale implies a higher sustainability compared to traditional manufacturing processes, recent research shows that some factors can make micro-manufacturing processes not as sustainable as expected. In particular, the use of rare raw materials and the need of higher purity of processes, to preserve product quality and manufacturing equipment, can be a source for additional environmental burden and process costs. Consequently, research is needed to optimize micro-manufacturing processes in order to guarantee the minimum consumption of raw materials, consumables and energy. In this paper, the experimental results obtained by the micro-electrical discharge machining (micro-EDM of micro-channels made on Ni–Cr–Mo steel is reported. The aim of such investigation is to shed a light on the relation and dependence between the material removal process, identified in the evaluation of material removal rate (MRR and tool wear ratio (TWR, and some of the most important technological parameters (i.e., open voltage, discharge current, pulse width and frequency, in order to experimentally quantify the material waste produced and optimize the technological process in order to decrease it.

Multigenic lentiviral vectors for combined and tissue-specific expression of miRNA- and protein-based antiangiogenic factors

Directory of Open Access Journals (Sweden)

Anne Louise Askou

Full Text Available Lentivirus-based gene delivery vectors carrying multiple gene cassettes are powerful tools in gene transfer studies and gene therapy, allowing coexpression of multiple therapeutic factors and, if desired, fluorescent reporters. Current strategies to express transgenes and microRNA (miRNA clusters from a single vector have certain limitations that affect transgene expression levels and/or vector titers. In this study, we describe a novel vector design that facilitates combined expression of therapeutic RNA- and protein-based antiangiogenic factors as well as a fluorescent reporter from back-to-back RNApolII-driven expression cassettes. This configuration allows effective production of intron-embedded miRNAs that are released upon transduction of target cells. Exploiting such multigenic lentiviral vectors, we demonstrate robust miRNA-directed downregulation of vascular endothelial growth factor (VEGF expression, leading to reduced angiogenesis, and parallel impairment of angiogenic pathways by codelivering the gene encoding pigment epithelium-derived factor (PEDF. Notably, subretinal injections of lentiviral vectors reveal efficient retinal pigment epithelium-specific gene expression driven by the VMD2 promoter, verifying that multigenic lentiviral vectors can be produced with high titers sufficient for in vivo applications. Altogether, our results suggest the potential applicability of combined miRNA- and protein-encoding lentiviral vectors in antiangiogenic gene therapy, including new combination therapies for amelioration of age-related macular degeneration.

PRELIMINARY STUDY ON RETRO-REFLECTIVE COATED PAPER BASED ON MICRO-GLASS BEADS

Institute of Scientific and Technical Information of China (English)

YulongWang; ChuanshanZhao; TaoZhang

2004-01-01

High-reflectivity micro-glass bead, as a kind ofretro-reflective material, is widely used in reflectivefabric or film and other reflective coatings. But it israrely used in coated paper. The retro-reflectivetheory of micro-bead is described. Also the effect ofsize of micro-bead, dosage of binder and differentcolor layers on reflective properties of coated paperare discussed in this article. The results show that itsretro-reflective efficiency is good, equally toreflective fabric or film when the micro-glass bead isused in coated paper.

Observations on Si-based micro-clusters embedded in TaN thin film deposited by co-sputtering with oxygen contamination

Energy Technology Data Exchange (ETDEWEB)

Lee, Young Mi [Beamline Division, Pohang Accelerator Laboratory, POSTECH, Pohang, 305-764 (Korea, Republic of); Jung, Min-Sang; Choi, Duck-Kyun, E-mail: duck@hanyang.ac.kr, E-mail: mcjung@oist.jp [Department of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Jung, Min-Cherl, E-mail: duck@hanyang.ac.kr, E-mail: mcjung@oist.jp [Energy Materials and Surface Sciences Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, 904-0495 (Japan)

2015-08-15

Using scanning electron microscopy (SEM) and high-resolution x-ray photoelectron spectroscopy with the synchrotron radiation we investigated Si-based micro-clusters embedded in TaSiN thin films having oxygen contamination. TaSiN thin films were deposited by co-sputtering on fixed or rotated substrates and with various power conditions of TaN and Si targets. Three types of embedded micro-clusters with the chemical states of pure Si, SiO{sub x}-capped Si, and SiO{sub 2}-capped Si were observed and analyzed using SEM and Si 2p and Ta 4f core-level spectra were derived. Their different resistivities are presumably due to the different chemical states and densities of Si-based micro-clusters.

Observations on Si-based micro-clusters embedded in TaN thin film deposited by co-sputtering with oxygen contamination

Directory of Open Access Journals (Sweden)

Young Mi Lee

2015-08-01

Full Text Available Using scanning electron microscopy (SEM and high-resolution x-ray photoelectron spectroscopy with the synchrotron radiation we investigated Si-based micro-clusters embedded in TaSiN thin films having oxygen contamination. TaSiN thin films were deposited by co-sputtering on fixed or rotated substrates and with various power conditions of TaN and Si targets. Three types of embedded micro-clusters with the chemical states of pure Si, SiOx-capped Si, and SiO2-capped Si were observed and analyzed using SEM and Si 2p and Ta 4f core-level spectra were derived. Their different resistivities are presumably due to the different chemical states and densities of Si-based micro-clusters.

Endogenous MCM7 microRNA cluster as a novel platform to multiplex small interfering and nucleolar RNAs for combinational HIV-1 gene therapy.

Science.gov (United States)

Chung, Janet; Zhang, Jane; Li, Haitang; Ouellet, Dominique L; DiGiusto, David L; Rossi, John J

2012-11-01

Combinational therapy with small RNA inhibitory agents against multiple viral targets allows efficient inhibition of viral production by controlling gene expression at critical time points. Here we explore combinations of different classes of therapeutic anti-HIV-1 RNAs expressed from within the context of an intronic MCM7 (minichromosome maintenance complex component-7) platform that naturally harbors 3 microRNAs (miRNAs). We replaced the endogenous miRNAs with anti-HIV small RNAs, including small interfering RNAs (siRNAs) targeting HIV-1 tat and rev messages that function to induce post-transcriptional gene silencing by the RNA interference pathway, a nucleolar-localizing RNA ribozyme that targets the conserved U5 region of HIV-1 transcripts for degradation, and finally nucleolar trans-activation response (TAR) and Rev-binding element (RBE) RNA decoys designed to sequester HIV-1 Tat and Rev proteins inside the nucleolus. We demonstrate the versatility of the MCM7 platform in expressing and efficiently processing the siRNAs as miRNA mimics along with nucleolar small RNAs. Furthermore, three of the combinatorial constructs tested potently suppressed viral replication during a 1-month HIV challenge, with greater than 5-log inhibition compared with untransduced, HIV-1-infected CEM T lymphocytes. One of the most effective constructs contains an anti-HIV siRNA combined with a nucleolar-localizing U5 ribozyme and TAR decoy. This represents the first efficacious example of combining Drosha-processed siRNAs with small nucleolar ribonucleoprotein (snoRNP)-processed nucleolar RNA chimeras from a single intron platform for effective inhibition of viral replication. Moreover, we demonstrated enrichment/selection for cells expressing levels of the antiviral RNAs that provide optimal inhibition under the selective pressure of HIV. The combinations of si/snoRNAs represent a new paradigm for combinatorial RNA-based gene therapy applications.

Experimental investigation of thermal storage integrated micro trigeneration system

International Nuclear Information System (INIS)

Johar, Dheeraj Kishor; Sharma, Dilip; Soni, Shyam Lal; Goyal, Rahul; Gupta, Pradeep K.

2017-01-01

Highlights: • Energy Storage System is integrated with Micro trigeneration system. • Erythritol is used as Phase Change Material. • Maximum energy saved is 15.30%. • Combined systems are feasible to increase energy efficiency. - Abstract: In this study a 4.4 kW stationary compression ignition engine is coupled with a double pipe heat exchanger, vapour absorption refrigeration system and thermal energy storage system to achieve Trigeneration i.e. power, heating and cooling. A shell and tube type heat exchanger filled with erythritol is used to store thermal energy of engine exhaust. Various combinations of thermal energy storage system integrated micro-trigeneration were investigated and results related to performance and emissions are reported in this paper. The test results show that micro capacity (4.4 kW) stationary single cylinder diesel engine can be successfully modified to simultaneously produce power, heating and cooling and also store thermal energy.

Quantitative Analysis of Micro-Structure in Meat Emulsions from Grating-Based Multimodal X-Ray Tomography

DEFF Research Database (Denmark)

Einarsdottir, Hildur; Nielsen, Mikkel Schou; Miklos, Rikke

2013-01-01

Using novel X-ray techniques, based on grating-interferometry, new imaging modalities can be obtained simultaneously with absorption computed tomography (CT). These modalities, called phase contrast and dark field imaging, measure the electron density and the diffusion length of the sample....... Enhanced contrast capabilities of this X-ray technique makes studies on materials with similar attenuation properties possible. In this paper the focus is set on processing grating-based X-ray tomograms of meat emulsions to quantitatively measure micro-structural changes due to heat treatment. The emulsion...... samples were imaged both in a raw and cooked state. Additionally, different fat types were used in the emulsions in order to compare micro-structural differences when either pork fat or sunflower oil was used. From the reconstructed tomograms the different ingredients in the emulsions were segmented using...

Non-invasive and micro-destructive investigation of the Domus Aurea wall painting decorations.

Science.gov (United States)

Clementi, Catia; Ciocan, Valeria; Vagnini, Manuela; Doherty, Brenda; Tabasso, Marisa Laurenzi; Conti, Cinzia; Brunetti, Brunetto Giovanni; Miliani, Costanza

2011-10-01

The paper reports on the exploitation of an educated multi-technique analytical approach based on a wide non invasive step followed by a focused micro-destructive step, aimed at the minimally invasive identification of the pigments decorating the ceiling of the Gilded Vault of the Domus Aurea in Rome. The combination of elemental analysis with molecular characterization provided by X-ray fluorescence and UV-vis spectroscopies, respectively, allowed for the in situ non-invasive identification of a remarkable number of pigments, namely Egyptian blue, green earth, cinnabar, red ochre and an anthraquinonic lake. The study was completed with the Raman analysis of two bulk samples, in particular, SERS measurements allowed for the speciation of the anthraquinonic pigment. Elemental mapping by scanning electron microscopy-energy dispersive spectrometer combined with micro-fluorimetry on cross-section gave an insight into both the distribution of different blend of pigments and on the nature of the inorganic support of the red dye.

Assessment of cancellous bone mechanical properties from micro-FE models based on micro-CT, pQCT and MR images.

NARCIS (Netherlands)

Rietbergen, van B.; Majumdar, S.; Pistoia, W.; Newitt, D.C.; Kothari, M.; Laib, A.; Rüegsegger, P.

1998-01-01

Recently, new micro-finite element (micro-FE) techniques have been introduced to calculate cancellous bone mechanical properties directly from high-resolution images of its internal architecture. Also recently, new peripheral quantitative computed tomography (pQCT) and magnetic resonance (MR)

ComfortPower. Design, construction and evaluation of a combined fuel-cell and heat pump system

Energy Technology Data Exchange (ETDEWEB)

Silversand, Fredrik (Catator AB, Lund (Sweden))

2010-12-15

Catator AB has constructed, commissioned and evaluated a combined fuel-cell and heat-pump system (ComfortPower). The basic idea behind the project was to demonstrate the possibility to achieve ultrahigh thermal efficiencies when combining fuel-cell technologies and heat pumps. Moreover, the system should provide a great flexibility with respect to the fuel mix and should in addition to heat provide surplus electricity and cooling. The system was built on a HT-PEM platform (high temperature polymer electrolyte fuel cell from Serenergy a/s), which was operated by Catators proprietary Optiformer technology. The power generator was combined with a heat pump module (F1145-5, 230 V), supplied by Nibe. The system was packaged into a cabinet (1.65 x 0.6 x 0.6 m) comprising the power module, the heat pump, all necessary balance-of-plant components and the control system. The power output from the fuel-cell system was around 1.35 kW, which enabled operation of the heat pump compressor. By utilizing surplus heat energy from the fuel cell it was possible to achieve a favourable operation point in the heat pump system, resulting in a high overall COP (coefficient of performance). The heat output from the system was as high as 10 kW whereas 6 kW cooling could be provided. The thermal efficiencies measured in experiments were normally around 200%, calculated on the lower heating value of the fuel. A number of fuels have been investigated in the fuel cell system, including both gaseous (natural gas/LPG) and liquid fuels (alcohols and kerosene). Indeed, the system has a wide fuel flexibility, which opens up for a variety of applications in campus villages and buildings. This study has demonstrated the possibility to reduce the carbon dioxide footprint by a factor of 2 over conventional boilers in heating applications. In addition the unit can be operated on a variety of fuels and can produce cooling and electricity in addition to heat. A fully working system has been designed

Experience of pico/micro hydro based power generation

Energy Technology Data Exchange (ETDEWEB)

Murthy, S.S. [Indian Inst. of Technology, Delhi, New Delhi (India). Dept. of Electrical Engineering

2010-07-01

Although India has approximately 150,000 megawatts of hydro potential, only a small portion is tapped. There is also significant untapped hydro potential in many developing countries such as Nepal, Bhutan, Vietnam, Indonesia and regions in South America and Africa. Small-scale hydroelectric power systems with capacities of up to a few megawatts are eco-friendly and sustainable. They can be classified based on unit sizes as pico (u pto 10 kilowatts), micro (10-100 kilowatts) and mini (100 kilowatts to a few megawatts) hydro systems. Mini hydro systems are always grid connected while micro can be either grid connected or off grid. Pico is always off grid. In India, there are thousands of favorable sites in this range that should be tapped for distributed power generation to electrify local communities. This need is reflected by the global emphasis on distributed power generation as well as the Government of India's policy to promote this type of power generation. A working stand alone pico-hydro power generating system has been successfully installed in 5 sites in Karnataka. The purpose of the project was to demonstrate the technical, managerial and economic feasibility of setting up small hydro projects in remote hilly areas of Karnataka, India and its positive environmental impact. The presentation discussed the site selection criteria; installed sites of pico hydro; system description; parts of the system; the electric load controller; types of electronic load controllers; and a description of the unit and control scheme. tabs., figs.

Micro-CT based finite element models for elastic properties of glass-ceramic scaffolds.

Science.gov (United States)

Tagliabue, Stefano; Rossi, Erica; Baino, Francesco; Vitale-Brovarone, Chiara; Gastaldi, Dario; Vena, Pasquale

2017-01-01

In this study, the mechanical properties of porous glass-ceramic scaffolds are investigated by means of three-dimensional finite element models based on micro-computed tomography (micro-CT) scan data. In particular, the quantitative relationship between the morpho-architectural features of the obtained scaffolds, such as macroscopic porosity and strut thickness, and elastic properties, is sought. The macroscopic elastic properties of the scaffolds have been obtained through numerical homogenization approaches using the mechanical characteristics of the solid walls of the scaffolds (assessed through nanoindentation) as input parameters for the numerical simulations. Anisotropic mechanical properties of the produced scaffolds have also been investigated by defining a suitable anisotropy index. A comparison with morphological data obtained through the micro-CT scans is also presented. The proposed study shows that the produced glass-ceramic scaffolds exhibited a macroscopic porosity ranging between 29% and 97% which corresponds to an average stiffness ranging between 42.4GPa and 36MPa. A quantitative estimation of the isotropy of the macroscopic elastic properties has been performed showing that the samples with higher solid fractions were those closest to an isotropic material. Copyright © 2016 Elsevier Ltd. All rights reserved.

3D micro-crack propagation simulation at enamel/adhesive interface using FE submodeling and element death techniques.

Science.gov (United States)

Liu, Heng-Liang; Lin, Chun-Li; Sun, Ming-Tsung; Chang, Yen-Hsiang

2010-06-01

This study investigates micro-crack propagation at the enamel/adhesive interface using finite element (FE) submodeling and element death techniques. A three-dimensional (3D) FE macro-model of the enamel/adhesive/ceramic subjected to shear bond testing was generated and analyzed. A 3D micro-model with interfacial bonding structure was constructed at the upper enamel/adhesive interface where the stress concentration was found from the macro-model results. The morphology of this interfacial bonding structure (i.e., resin tag) was assigned based on resin tag geometry and enamel rod arrangement from a scanning electron microscopy micrograph. The boundary conditions for the micro-model were determined from the macro-model results. A custom iterative code combined with the element death technique was used to calculate the micro-crack propagation. Parallel experiments were performed to validate this FE simulation. The stress concentration within the adhesive occurred mainly at the upper corner near the enamel/adhesive interface and the resin tag base. A simulated fracture path was found at the resin tag base along the enamel/adhesive interface. A morphological observation of the fracture patterns obtained from in vitro testing corresponded with the simulation results. This study shows that the FE submodeling and element death techniques could be used to simulate the 3D micro-stress pattern and the crack propagation noted at the enamel/adhesive interface.

Virtual commissioning of automated micro-optical assembly

Science.gov (United States)

Schlette, Christian; Losch, Daniel; Haag, Sebastian; Zontar, Daniel; Roßmann, Jürgen; Brecher, Christian

2015-02-01

In this contribution, we present a novel approach to enable virtual commissioning for process developers in micro-optical assembly. Our approach aims at supporting micro-optics experts to effectively develop assisted or fully automated assembly solutions without detailed prior experience in programming while at the same time enabling them to easily implement their own libraries of expert schemes and algorithms for handling optical components. Virtual commissioning is enabled by a 3D simulation and visualization system in which the functionalities and properties of automated systems are modeled, simulated and controlled based on multi-agent systems. For process development, our approach supports event-, state- and time-based visual programming techniques for the agents and allows for their kinematic motion simulation in combination with looped-in simulation results for the optical components. First results have been achieved for simply switching the agents to command the real hardware setup after successful process implementation and validation in the virtual environment. We evaluated and adapted our system to meet the requirements set by industrial partners-- laser manufacturers as well as hardware suppliers of assembly platforms. The concept is applied to the automated assembly of optical components for optically pumped semiconductor lasers and positioning of optical components for beam-shaping

Establishment of the Credit Indicator System of Micro Enterprises Based on Support Vector Machine and R-Type Clustering

Directory of Open Access Journals (Sweden)

Zhanjiang Li

2018-01-01

Full Text Available The micro enterprises’ credit indicators with credit identification ability are selected by the two classification models of Support Vector Machine for the first round of indicator selection and then for the second round of indicator selection, deleting credit indicators with redundant information by clustering variables through the principle of minimum sum of deviation squares. This paper provides a screening model for credit evaluation indicators of micro enterprises and uses credit data of 860 micro enterprises samples in Inner Mongolia in western China for application analysis. The test results show that, first, the constructed final micro enterprises’ credit indicator system is in line with the 5C model; second, the validity test based on the ROC (Receiver Operating Characteristic curve reveals that each of the screened credit evaluation indicators is valid.

Application of TALE-Based Approach for Dissecting Functional MicroRNA-302/367 in Cellular Reprogramming.

Science.gov (United States)

Zhang, Zhonghui; Wu, Wen-Shu

2018-01-01

MicroRNAs are small 18-24 nt single-stranded noncoding RNA molecules involved in many biological processes, including stemness maintenance and cellular reprogramming. Current methods used in loss-of-function studies of microRNAs have several limitations. Here, we describe a new approach for dissecting miR-302/367 functions by transcription activator-like effectors (TALEs), which are natural effector proteins secreted by Xanthomonas and Ralstonia bacteria. Knockdown of the miR-302/367 cluster uses the Kruppel-associated box repressor domain fused with specific TALEs designed to bind the miR-302/367 cluster promoter. Knockout of the miR-302/367 cluster uses two pairs of TALE nucleases (TALENs) to delete the miR-302/367 cluster in human primary cells. Together, both TALE-based transcriptional repressor and TALENs are two promising approaches for loss-of-function studies of microRNA cluster in human primary cells.

Design, fabrication, and evaluation of on-chip micro-supercapacitors

Science.gov (United States)

Beidaghi, Majid; Chen, Wei; Wang, Chunlei

2011-06-01

Development of miniaturized electronic systems has stimulated the demand for miniaturized power sources that can be integrated into such systems. Among the different micro power sources micro electrochemical energy storage and conversion devices are particularly attractive because of their high efficiency and relatively high energy density. Electrochemical micro-capacitors or micro-supercapacitors offer higher power density compared to micro-batteries and micro-fuel cells. In this paper, development of on-chip micro-supercapacitors based on interdigitated C-MEMS electrode microarrays is introduced. C-MEMS electrodes are employed both as electrode material for electric double layer capacitor (EDLC) or as three dimensional (3D) current collectors of EDLC or pseudo-capacitive materials. Recent advancements in fabrication methods of C-MEMS based micro-supercapacitors are discussed and electrochemical properties of C-MEMS electrodes and it composites are reviewed.