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Sample records for active microwave devices

  1. Design of microwave active devices

    CERN Document Server

    Gautier , Jean-Luc

    2014-01-01

    This book presents methods for the design of the main microwave active devices. The first chapter focuses on amplifiers working in the linear mode. The authors present the problems surrounding narrowband and wideband impedance matching, stability, polarization and the noise factor, as well as specific topologies such as the distributed amplifier and the differential amplifier. Chapter 2 concerns the power amplifier operation. Specific aspects on efficiency, impedance matching and class of operation are presented, as well as the main methods of linearization and efficiency improvement. Freq

  2. Active Microwave Metamaterials Incorporating Ideal Gain Devices

    Directory of Open Access Journals (Sweden)

    Hao Xin

    2010-12-01

    Full Text Available Incorporation of active devices/media such as transistors for microwave and gain media for optics may be very attractive for enabling desired low loss and broadband metamaterials. Such metamaterials can even have gain which may very well lead to new and exciting physical phenomena. We investigate microwave composite right/left-handed transmission lines (CRLH-TL incorporating ideal gain devices such as constant negative resistance. With realistic lumped element values, we have shown that the negative phase constant of this kind of transmission lines is maintained (i.e., left-handedness kept while gain can be obtained (negative attenuation constant of transmission line simultaneously. Possible implementation and challenging issues of the proposed active CRLH-TL are also discussed.

  3. Practical microwave electron devices

    CERN Document Server

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  4. Monolithic microwave integrated circuit devices for active array antennas

    Science.gov (United States)

    Mittra, R.

    1984-01-01

    Two different aspects of active antenna array design were investigated. The transition between monolithic microwave integrated circuits and rectangular waveguides was studied along with crosstalk in multiconductor transmission lines. The boundary value problem associated with a discontinuity in a microstrip line is formulated. This entailed, as a first step, the derivation of the propagating as well as evanescent modes of a microstrip line. The solution is derived to a simple discontinuity problem: change in width of the center strip. As for the multiconductor transmission line problem. A computer algorithm was developed for computing the crosstalk noise from the signal to the sense lines. The computation is based on the assumption that these lines are terminated in passive loads.

  5. Microwave heating denitration device

    International Nuclear Information System (INIS)

    Sato, Hajime; Morisue, Tetsuo.

    1984-01-01

    Purpose: To suppress energy consumption due to a reflection of microwaves. Constitution: Microwaves are irradiated to the nitrate solution containing nuclear fuel materials, to cause denitrating reaction under heating and obtain oxides of the nuclear fuel materials. A microwave heating and evaporation can for reserving the nitrate solution is disposed slantwise relative to the horizontal plane and a microwave heating device is connected to the evaporation can, and inert gases for agitation are supplied to the solution within the can. Since the evaporation can is slanted, wasteful energy consumption due to the reflection of the microwaves can be suppressed. (Moriyama, K.)

  6. Microwave warning device

    International Nuclear Information System (INIS)

    Shriner, W.

    1981-01-01

    A device for warning a person carrying or wearing it of the presence of dangerous microwave radiation is fully powered by the radiations being detected. A very low-wattage gas-discharge lamp is energized by a broadly or a sharply tuned receiver circuit including dipole antennas or one antenna and a ''grounding'' casing element. The casing may be largely and uniformly transparent or have different areas gradedly light-transmissive to indicate varying radiation intensities. The casing can be made in the shape of a pocket watch, fountain pen, bracelet or finger ring, etc

  7. Global Modeling of Microwave Three Terminal Active Devices Using the FDTD Method

    National Research Council Canada - National Science Library

    Mrabet, O. E; Essaaidi, M; Drissi, M'hamed

    2005-01-01

    This paper presents a new approach for the global electromagnetic analysis of the three-Terminal active linear and nonlinear microwave circuits using the Finite-Difference Time Domain (FDTD) Method...

  8. Microwave ablation devices for interventional oncology.

    Science.gov (United States)

    Ward, Robert C; Healey, Terrance T; Dupuy, Damian E

    2013-03-01

    Microwave ablation is one of the several options in the ablation armamentarium for the treatment of malignancy, offering several potential benefits when compared with other ablation, radiation, surgical and medical treatment modalities. The basic microwave system consists of the generator, power distribution system and antennas. Often under image (computed tomography or ultrasound) guidance, a needle-like antenna is inserted percutaneously into the tumor, where local microwave electromagnetic radiation is emitted from the probe's active tip, producing frictional tissue heating, capable of causing cell death by coagulation necrosis. Half of the microwave ablation systems use a 915 MHz generator and the other half use a 2450 MHz generator. To date, there are no completed clinical trials comparing microwave devices head-to-head. Prospective comparisons of microwave technology with other treatment alternatives, as well as head-to-head comparison with each microwave device, is needed if this promising field will garner more widespread support and use in the oncology community.

  9. Fundamental Properties and Practical Application of Active Microwave Metamaterials Incorporating Gain Devices

    Science.gov (United States)

    2017-02-22

    person shall be subject to any penalty for failing to comply with a collection of information   if it does not display a currently valid OMB control... transmission line and an active volumetric metamaterial. These designs have been extended to THz frequency range. In addition, we have investigated the non...circuits,” IEEE International Microwave Symposium, Phoenix, Arizona, May 17-22, 2015. [7] Q. Tang, and H. Xin, “Stability of Tunnel Diode based Negative

  10. Wide gap semiconductor microwave devices

    International Nuclear Information System (INIS)

    Buniatyan, V V; Aroutiounian, V M

    2007-01-01

    A review of properties of wide gap semiconductor materials such as diamond, diamond-like carbon films, SiC, GaP, GaN and AlGaN/GaN that are relevant to electronic, optoelectronic and microwave applications is presented. We discuss the latest situation and perspectives based on experimental and theoretical results obtained for wide gap semiconductor devices. Parameters are taken from the literature and from some of our theoretical works. The correspondence between theoretical results and parameters of devices is critically analysed. (review article)

  11. Continuous denitration device using a microwave furnace

    International Nuclear Information System (INIS)

    Sato, Hajime

    1982-04-01

    A continuous denitration device is described that enables to obtain dried U or Pu dioxide or a mixture of these from a solution of uranyl or plutonium nitrate or a mixed solution of these by irradiation with microwaves. This device allows uranyl or plutonium nitrate to crystallize and the resulting crystals to be separated from the solution. A belt conveyer carries the crystals to a microwave heating furnace for denitration. Approximately 2.4 kg dried cake of U dioxide per hour is obtained [fr

  12. Microwave Regenerable Air Purification Device

    Science.gov (United States)

    Atwater, James E.; Holtsnider, John T.; Wheeler, Richard R., Jr.

    1996-01-01

    The feasibility of using microwave power to thermally regenerate sorbents loaded with water vapor, CO2, and organic contaminants has been rigorously demonstrated. Sorbents challenged with air containing 0.5% CO2, 300 ppm acetone, 50 ppm trichloroethylene, and saturated with water vapor have been regenerated, singly and in combination. Microwave transmission, reflection, and phase shift has also been determined for a variety of sorbents over the frequency range between 1.3-2.7 GHz. This innovative technology offers the potential for significant energy savings in comparison to current resistive heating methods because energy is absorbed directly by the material to be heated. Conductive, convective and radiative losses are minimized. Extremely rapid heating is also possible, i.e., 1400 C in less than 60 seconds. Microwave powered thermal desorption is directly applicable to the needs of Advance Life Support in general, and of EVA in particular. Additionally, the applicability of two specific commercial applications arising from this technology have been demonstrated: the recovery for re-use of acetone (and similar solvents) from industrial waste streams using a carbon based molecular sieve; and the separation and destruction of trichloroethylene using ZSM-5 synthetic zeolite catalyst, a predominant halocarbon environmental contaminant. Based upon these results, Phase II development is strongly recommended.

  13. Microwave produced plasma in a Toroidal Device

    Science.gov (United States)

    Singh, A. K.; Edwards, W. F.; Held, E. D.

    2010-11-01

    A currentless toroidal plasma device exhibits a large range of interesting basic plasma physics phenomena. Such a device is not in equilibrium in a strict magneto hydrodynamic sense. There are many sources of free energy in the form of gradients in plasma density, temperature, the background magnetic field and the curvature of the magnetic field. These free energy sources excite waves and instabilities which have been the focus of studies in several devices in last two decades. A full understanding of these simple plasmas is far from complete. At Utah State University we have recently designed and installed a microwave plasma generation system on a small tokamak borrowed from the University of Saskatchewan, Saskatoon, Canada. Microwaves are generated at 2.45 GHz in a pulsed dc mode using a magnetron from a commercial kitchen microwave oven. The device is equipped with horizontal and vertical magnetic fields and a transformer to impose a toroidal electric field for current drive. Plasmas can be obtained over a wide range of pressure with and without magnetic fields. We present some preliminary measurements of plasma density and potential profiles. Measurements of plasma temperature at different operating conditions are also presented.

  14. Application of high power microwave vacuum electron devices

    International Nuclear Information System (INIS)

    Ding Yaogen; Liu Pukun; Zhang Zhaochuan; Wang Yong; Shen Bin

    2011-01-01

    High power microwave vacuum electron devices can work at high frequency, high peak and average power. They have been widely used in military and civil microwave electron systems, such as radar, communication,countermeasure, TV broadcast, particle accelerators, plasma heating devices of fusion, microwave sensing and microwave heating. In scientific research, high power microwave vacuum electron devices are used mainly on high energy particle accelerator and fusion research. The devices include high peak power klystron, CW and long pulse high power klystron, multi-beam klystron,and high power gyrotron. In national economy, high power microwave vacuum electron devices are used mainly on weather and navigation radar, medical and radiation accelerator, TV broadcast and communication system. The devices include high power pulse and CW klystron, extended interaction klystron, traveling wave tube (TWT), magnetron and induced output tube (IOT). The state of art, common technology problems and trends of high power microwave vacuum electron devices are introduced in this paper. (authors)

  15. Tunable Magnetic Resonance in Microwave Spintronics Devices

    Science.gov (United States)

    Chen, Yunpeng; Fan, Xin; Xie, Yunsong; Zhou, Yang; Wang, Tao; Wilson, Jeffrey D.; Simons, Rainee N.; Chui, Sui-Tat; Xiao, John Q.

    2015-01-01

    Magnetic resonance is one of the key properties of magnetic materials for the application of microwave spintronics devices. The conventional method for tuning magnetic resonance is to use an electromagnet, which provides very limited tuning range. Hence, the quest for enhancing the magnetic resonance tuning range without using an electromagnet has attracted tremendous attention. In this paper, we exploit the huge exchange coupling field between magnetic interlayers, which is on the order of 4000 Oe and also the high frequency modes of coupled oscillators to enhance the tuning range. Furthermore, we demonstrate a new scheme to control the magnetic resonance frequency. Moreover, we report a shift in the magnetic resonance frequency as high as 20 GHz in CoFe based tunable microwave spintronics devices, which is 10X higher than conventional methods.

  16. Large Signal Characterization of Microwave Power Devices

    OpenAIRE

    Teyssier, Jean-Pierre; Barataud, D.; Charbonniaud, C.; De Groote, Fabien; Mayer, Markus; Nébus, Jean-Michel; Quéré, Raymond

    2004-01-01

    This paper presents an overview of nonlinear measurement techniques of microwave power devices and amplifiers. Several useful measurement techniques of nonlinear components available in Europe are described. Trends, especially in the area of high power and time domain measurements, are discussed. Finally, a summary of the TARGET measurement related tasks is proposed, in order to show how TARGET can improve the European capabilities in terms of nonlinear measurements.

  17. Perovskite Superlattices as Tunable Microwave Devices

    Science.gov (United States)

    Christen, H. M.; Harshavardhan, K. S.

    2003-01-01

    Experiments have shown that superlattices that comprise alternating epitaxial layers of dissimilar paraelectric perovskites can exhibit large changes in permittivity with the application of electric fields. The superlattices are potentially useful as electrically tunable dielectric components of such microwave devices as filters and phase shifters. The present superlattice approach differs fundamentally from the prior use of homogeneous, isotropic mixtures of base materials and dopants. A superlattice can comprise layers of two or more perovskites in any suitable sequence (e.g., ABAB..., ABCDABCD..., ABACABACA...). Even though a single layer of one of the perovskites by itself is not tunable, the compositions and sequence of the layers can be chosen so that (1) the superlattice exhibits low microwave loss and (2) the interfacial interaction between at least two of the perovskites in the superlattice renders either the entire superlattice or else at least one of the perovskites tunable.

  18. Large-power microwave circuit device

    International Nuclear Information System (INIS)

    Suzuki, Kunio

    1987-01-01

    A 250 KW CW circulator and 1 MW CW dammy load are developed as large-power microwave circuit devices for Tristan, and they are shown to have good characteristics. The circulator has a Y-shape and consists of waveguides divided into four parts. Partition plates are provided in the waveguide connected to each port in order to divide the power into four components. A ferrite material which is high in Curie temperature and less likely to suffer from a RF loss is selected to be used in the circulator. Thin disks of this material, which is low in temperature gradient in the direction of thickness, are bonded to the surface of the waveguides with an epoxy adhesive. A magnet is provided at the top and bottom of the main portion of the circulator and the magnetic field is adjusted so that optimum characteristics are achieved. These arrangements result in good electrical and power characteristics. The dammy load of a water loading type is selected because microwave power is easily absorbed in water. A mechanically strong pipe which does not cause a large loss in microwave is mounted in a waveguide and water is passed through it to allow the power to be consumed gradually. A test up to a RF power of 750 KW shows that the temperature rise in the waveguide is 30 deg C. (Nogami, K.)

  19. The review of CAD for simulation of microwave devices

    Directory of Open Access Journals (Sweden)

    Drach V.E.

    2017-01-01

    Full Text Available the article is devoted to a brief review of modern CAD for electromagnetic modeling of microwave devices. Five major CAD systems are described in the article: FEKO, μWave Wizard, Sonnet, AWR Microwave Office, HFSS. The main methods are given for each CAD system used for simulation of microwave structures and the main advantages that distinguish its use.

  20. Microwave impedance imaging on semiconductor memory devices

    Science.gov (United States)

    Kundhikanjana, Worasom; Lai, Keji; Yang, Yongliang; Kelly, Michael; Shen, Zhi-Xun

    2011-03-01

    Microwave impedance microscopy (MIM) maps out the real and imaginary components of the tip-sample impedance, from which the local conductivity and dielectric constant distribution can be derived. The stray field contribution is minimized in our shielded cantilever design, enabling quantitative analysis of nano-materials and device structures. We demonstrate here that the MIM can spatially resolve the conductivity variation in a dynamic random access memory (DRAM) sample. With DC or low-frequency AC bias applied to the tip, contrast between n-doped and p-doped regions in the dC/dV images is observed, and p-n junctions are highlighted in the dR/dV images. The results can be directly compared with data taken by scanning capacitance microscope (SCM), which uses unshielded cantilevers and resonant electronics, and the MIM reveals more information of the local dopant concentration than SCM.

  1. Microwave Activation of Drug Release

    DEFF Research Database (Denmark)

    Jónasson, Sævar Þór

    Due to current limitations in control of pharmaceutical drug release in the body along with increasing medicine use, methods of externally-controlled drug release are of high interest. In this thesis, the use of microwaves is proposed as a technique with the purpose of externally activating...... setup, called the microwave activation system has been developed and tested on a body phantom that emulates the human torso. The system presented in this thesis, operates unobtrusively, i.e. without physically interfering with the target (patient). The torso phantom is a simple dual-layered cylindrical...... the phantom is of interest for disclosing essential information about the limitations of the concept, the phantom and the system. For these purposes, a twofold operation of the microwave activation system was performed, which are reciprocal of each other. In the first operation phase, named mapping...

  2. Integration of semiconductor and ceramic superconductor devices for microwave applications

    NARCIS (Netherlands)

    Klopman, B.B.G.; Klopman, B.B.G.; Wijers, H.W.; Gao, J.; Gao, J.; Gerritsma, G.J.; Rogalla, Horst

    1991-01-01

    Due to the very-low-loss properties of ceramic superconductors, high-performance microwave resonators and filters can be realized. The fact that these devices may be operated at liquid nitrogen temperature facilitates integration with semiconductor devices. Examples are bandpass amplifiers,

  3. Continuous denitration device by microwave heating

    International Nuclear Information System (INIS)

    Matsumaru, Ken-ichi; Sato, Hajime.

    1982-01-01

    Purpose: To continuously obtain powder of uranium dioxide, plutonium dioxide or a mixture of them respectively from the solution of uranyl nitrate, plutonium nitrate or a mixture of them effectively while maintaining a constant quality. Constitution: Plutonium nitrate or uranium nitrate solution is deposited on a rotational drum having a heater and dried into powderous products. The powderous products are scraped off by a blade, transferred to a belt conveyor, entered into a microwave heating furnace and heated by microwaves while stirring to obtain the powder of plutonium dioxide or uranium dioxide. The powderous products are scraped off by a scraper and collected in a receiving tank for denitration products, whereby the feeding solution can be denitrated continuously. (Horiuchi, T.)

  4. Integration of semiconductor and ceramic superconductor devices for microwave applications

    International Nuclear Information System (INIS)

    Klopman, B.B.G.; Weijers, H.W.; Gao, J.; Gerritsma, G.J.; Rogalla, H.

    1991-01-01

    Due to the very low-loss properties of ceramic superconductors high-performance microwave resonators and filters can be realized. The fact that these devices may be operated at liquid nitrogen temperature, facilitates the integration with semiconductor devices. Examples are bandpass amplifiers, microwave-operated SQUIDs combined with GaAs preamplifiers, detectors, and MOSFET low-frequency amplifiers. This paper discusses the design of such circuits on a single one inch alumina substrate using surface mount techniques. Furthermore data on circuits that have been realized in our laboratory will be presented

  5. Microwave assisted synthesis and characterisation of a zinc oxide/tobacco mosaic virus hybrid material. An active hybrid semiconductor in a field-effect transistor device

    Directory of Open Access Journals (Sweden)

    Shawn Sanctis

    2015-03-01

    Full Text Available Tobacco mosaic virus (TMV has been employed as a robust functional template for the fabrication of a TMV/zinc oxide field effect transistor (FET. A microwave based approach, under mild conditions was employed to synthesize stable zinc oxide (ZnO nanoparticles, employing a molecular precursor. Insightful studies of the decomposition of the precursor were done using NMR spectroscopy and material characterization of the hybrid material derived from the decomposition was achieved using dynamic light scattering (DLS, transmission electron microscopy (TEM, grazing incidence X-ray diffractometry (GI-XRD and atomic force microscopy (AFM. TEM and DLS data confirm the formation of crystalline ZnO nanoparticles tethered on top of the virus template. GI-XRD investigations exhibit an orientated nature of the deposited ZnO film along the c-axis. FET devices fabricated using the zinc oxide mineralized virus template material demonstrates an operational transistor performance which was achieved without any high-temperature post-processing steps. Moreover, a further improvement in FET performance was observed by adjusting an optimal layer thickness of the deposited ZnO on top of the TMV. Such a bio-inorganic nanocomposite semiconductor material accessible using a mild and straightforward microwave processing technique could open up new future avenues within the field of bio-electronics.

  6. Advances in ferrite microwave materials and devices

    International Nuclear Information System (INIS)

    Schloemann, Ernst

    2000-01-01

    The application of ferrites in non-reciprocal components is discussed, with the emphasis on broadband isolators and circulators. The performance of such devices may be characterized by the ratio f max /f min of the frequencies that define the edges of the frequency band, within which satisfactory performance has been achieved. For the best currently available devices this ratio is approx. 3 : 1, but larger values appear feasible according to a detailed analysis of the 'low-field, low-frequency loss' that limits the performance

  7. High-temperature superconducting passive microwave devices, filters and antennas

    International Nuclear Information System (INIS)

    Ohshima, S.

    2000-01-01

    High-temperature superconducting (HTS) passive microwave devices, such as filters and antennas, are promising devices. In particular, HTS filters may be successfully marketed in the near future. Cross-coupled filters, ring filters, and coplanar waveguide filters are good options to reduce filter size. On the other hand, HTS patch antennas which can be cooled by a cryo-cooler are also promising devices as well, since they show higher efficiency than normal antennas. This paper examines the design process and filter properties of HTS filters as well as the gains, directivity, and cooling system of HTS patch antennas. (author)

  8. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

    International Nuclear Information System (INIS)

    Wang Ziming; Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi; Ma Qiang; Lu Chunmei; Dong Deming

    2013-01-01

    Highlights: ► An absorbing microwave μ-SPE device packed with activated carbon was used. ► Absorbing microwave μ-SPE device was made and used to enrich the analytes. ► Absorbing microwave μ-SPE device was made and used to heat samples directly. ► MAE-μ-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 °C for 10 min. The extracts obtained by MAE-μ-SPE were directly analyzed by GC–MS without any clean-up process. The recoveries were in the range of 93.5–104.6%, and the relative standard deviations were lower than 8.7%.

  9. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ziming, E-mail: wangziming@jlu.edu.cn [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Ma Qiang [Chinese Academy of Inspection and Quarantine, Beijing 100123 (China); Lu Chunmei [College of Technology Center, Jilin Entry-Exit Inspection and Quarantine Bureau, Changchun 130062 (China); Dong Deming [College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)

    2013-01-14

    Highlights: Black-Right-Pointing-Pointer An absorbing microwave {mu}-SPE device packed with activated carbon was used. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to enrich the analytes. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to heat samples directly. Black-Right-Pointing-Pointer MAE-{mu}-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction ({mu}-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave {mu}-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in {mu}-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave {mu}-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 Degree-Sign C for 10 min. The extracts obtained by MAE-{mu}-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%.

  10. Electrically Tuned Microwave Devices Using Liquid Crystal Technology

    Directory of Open Access Journals (Sweden)

    Pouria Yaghmaee

    2013-01-01

    Full Text Available An overview of liquid crystal technology for microwave and millimeter-wave frequencies is presented. The potential of liquid crystals as reconfigurable materials arises from their ability for continuous tuning with low power consumption, transparency, and possible integration with printed and flexible circuit technologies. This paper describes physical theory and fundamental electrical properties arising from the anisotropy of liquid crystals and overviews selected realized liquid crystal devices, throughout four main categories: resonators and filters, phase shifters and delay lines, antennas, and, finally, frequency-selective surfaces and metamaterials.

  11. Examination of a microwave sensing system using superconducting devices

    International Nuclear Information System (INIS)

    Sekiya, N.; Mukaida, M.; Saito, A.; Hirano, S.; Oshima, S.

    2005-01-01

    We have designed and fabricated a microwave sensing system integrated with superconducting devices which can detect motion for crime prevention and security purposes. The system consists of a transmitting antenna, a receiving antenna, a power divider as a directional coupler, and a mixer. The antennas and the directional coupler were fabricated using 50-nm thick YBa 2 Cu 3 O 7-δ (YBCO) thin films. A superconducting antenna with a resonant frequency of 10.525 GHz and a superconducting directional coupler were designed and fabricated for the system. A Schottky barrier diode was used as a mixer. These devices were integrated and their operation as a sensor was examined. Comparisons of the output voltage of the IF signal amplifier showed that the superconducting integrated sensor system was superior to the normal conductor sensor

  12. UNIPIC code for simulations of high power microwave devices

    International Nuclear Information System (INIS)

    Wang Jianguo; Zhang Dianhui; Wang Yue; Qiao Hailiang; Li Xiaoze; Liu Chunliang; Li Yongdong; Wang Hongguang

    2009-01-01

    In this paper, UNIPIC code, a new member in the family of fully electromagnetic particle-in-cell (PIC) codes for simulations of high power microwave (HPM) generation, is introduced. In the UNIPIC code, the electromagnetic fields are updated using the second-order, finite-difference time-domain (FDTD) method, and the particles are moved using the relativistic Newton-Lorentz force equation. The convolutional perfectly matched layer method is used to truncate the open boundaries of HPM devices. To model curved surfaces and avoid the time step reduction in the conformal-path FDTD method, CP weakly conditional-stable FDTD (WCS FDTD) method which combines the WCS FDTD and CP-FDTD methods, is implemented. UNIPIC is two-and-a-half dimensional, is written in the object-oriented C++ language, and can be run on a variety of platforms including WINDOWS, LINUX, and UNIX. Users can use the graphical user's interface to create the geometric structures of the simulated HPM devices, or input the old structures created before. Numerical experiments on some typical HPM devices by using the UNIPIC code are given. The results are compared to those obtained from some well-known PIC codes, which agree well with each other.

  13. UNIPIC code for simulations of high power microwave devices

    Science.gov (United States)

    Wang, Jianguo; Zhang, Dianhui; Liu, Chunliang; Li, Yongdong; Wang, Yue; Wang, Hongguang; Qiao, Hailiang; Li, Xiaoze

    2009-03-01

    In this paper, UNIPIC code, a new member in the family of fully electromagnetic particle-in-cell (PIC) codes for simulations of high power microwave (HPM) generation, is introduced. In the UNIPIC code, the electromagnetic fields are updated using the second-order, finite-difference time-domain (FDTD) method, and the particles are moved using the relativistic Newton-Lorentz force equation. The convolutional perfectly matched layer method is used to truncate the open boundaries of HPM devices. To model curved surfaces and avoid the time step reduction in the conformal-path FDTD method, CP weakly conditional-stable FDTD (WCS FDTD) method which combines the WCS FDTD and CP-FDTD methods, is implemented. UNIPIC is two-and-a-half dimensional, is written in the object-oriented C++ language, and can be run on a variety of platforms including WINDOWS, LINUX, and UNIX. Users can use the graphical user's interface to create the geometric structures of the simulated HPM devices, or input the old structures created before. Numerical experiments on some typical HPM devices by using the UNIPIC code are given. The results are compared to those obtained from some well-known PIC codes, which agree well with each other.

  14. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides.

    Science.gov (United States)

    Wang, Ziming; Zhao, Xin; Xu, Xu; Wu, Lijie; Su, Rui; Zhao, Yajing; Jiang, Chengfei; Zhang, Hanqi; Ma, Qiang; Lu, Chunmei; Dong, Deming

    2013-01-14

    A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60°C for 10 min. The extracts obtained by MAE-μ-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Novel Polymeric Dielectric Materials for the Additive Manufacturing of Microwave Devices

    Science.gov (United States)

    O'Keefe, Shamus E.

    functional groups) and dielectric properties were explored. The results indicate that backbone rigidity and the inclusion of fluorine lead to excellent dielectric properties, however, often at the expense of mechanical properties. Chapter 5 explores the optimization of PTFE core-shell nanoparticles via a novel PTFE/polyimide (PI) core-shell nanoparticle. PTFE/PI core-shell nanoparticles were synthesized via electrostatic interaction between the PTFE cores and a PI precursor, poly(amic) acid salt (PAAS). The PAAS is converted to PI by thermal imidization. The PI has properties superior to those of PA for microwave applications and the results suggest the promise of PTFE/PI core-shell nanoparticles for use in AM of microwave devices. Chapter 6 describes the first report of on actively-tunable microwave substrate made possible by a semiconducting polymer composite blend. The composite blend is comprised of poly(3-hexylthiophene) (P3HT) as the semiconducting polymer and [6,6]-Phenyl C61 butyric acid methyl ester (PCBM) while the remainder of the composite is comprised of a low dielectric constant polymer polydimethylsiloxane (PDMS). When subjected to photo excitation (white light, spectrum centered at 532 nm), the composite exhibits a tunability of the permittivity up to 20%. The results suggest strong promise for the use of semiconducting polymers in actively-tunable microwave devices. Finally, Chapter 7 presents a summary of the salient conclusions of the reported studies. The chapter concludes with a few brief remarks of my personal experience as a non-traditional student and the challenges therein.

  16. Thermo-Chemical Conversion of Microwave Activated Biomass Mixtures

    Science.gov (United States)

    Barmina, I.; Kolmickovs, A.; Valdmanis, R.; Vostrikovs, S.; Zake, M.

    2018-05-01

    Thermo-chemical conversion of microwave activated wheat straw mixtures with wood or peat pellets is studied experimentally with the aim to provide more effective application of wheat straw for heat energy production. Microwave pre-processing of straw pellets is used to provide a partial decomposition of the main constituents of straw and to activate the thermo-chemical conversion of wheat straw mixtures with wood or peat pellets. The experimental study includes complex measurements of the elemental composition of biomass pellets (wheat straw, wood, peat), DTG analysis of their thermal degradation, FTIR analysis of the composition of combustible volatiles entering the combustor, the flame temperature, the heat output of the device and composition of the products by comparing these characteristics for mixtures with unprocessed and mw pre-treated straw pellets. The results of experimental study confirm that mw pre-processing of straw activates the thermal decomposition of mixtures providing enhanced formation of combustible volatiles. This leads to improvement of the combustion conditions in the flame reaction zone, completing thus the combustion of volatiles, increasing the flame temperature, the heat output from the device, the produced heat energy per mass of burned mixture and decreasing at the same time the mass fraction of unburned volatiles in the products.

  17. AMISS - Active and passive MIcrowaves for Security and Subsurface imaging

    Science.gov (United States)

    Soldovieri, Francesco; Slob, Evert; Turk, Ahmet Serdar; Crocco, Lorenzo; Catapano, Ilaria; Di Matteo, Francesca

    2013-04-01

    The FP7-IRSES project AMISS - Active and passive MIcrowaves for Security and Subsurface imaging is based on a well-combined network among research institutions of EU, Associate and Third Countries (National Research Council of Italy - Italy, Technische Universiteit Delft - The Netherlands, Yildiz Technical University - Turkey, Bauman Moscow State Technical University - Russia, Usikov Institute for Radio-physics and Electronics and State Research Centre of Superconductive Radioelectronics "Iceberg" - Ukraine and University of Sao Paulo - Brazil) with the aims of achieving scientific advances in the framework of microwave and millimeter imaging systems and techniques for security and safety social issues. In particular, the involved partners are leaders in the scientific areas of passive and active imaging and are sharing their complementary knowledge to address two main research lines. The first one regards the design, characterization and performance evaluation of new passive and active microwave devices, sensors and measurement set-ups able to mitigate clutter and increase information content. The second line faces the requirements to make State-of-the-Art processing tools compliant with the instrumentations developed in the first line, suitable to work in electromagnetically complex scenarios and able to exploit the unexplored possibilities offered by new instrumentations. The main goals of the project are: 1) Development/improvement and characterization of new sensors and systems for active and passive microwave imaging; 2) Set up, analysis and validation of state of art/novel data processing approach for GPR in critical infrastructure and subsurface imaging; 3) Integration of state of art and novel imaging hardware and characterization approaches to tackle realistic situations in security, safety and subsurface prospecting applications; 4) Development and feasibility study of bio-radar technology (system and data processing) for vital signs detection and

  18. Plasma electron density measurement with multichannel microwave interferometer on the HL-1 tokamak device

    International Nuclear Information System (INIS)

    Xu Deming; Zhang Hongyin; Liu Zetian; Ding Xuantong; Li Qirui; Wen Yangxi

    1989-11-01

    A multichannel microwave interferometer which is composed of different microwave interferometers (one 2 mm band, one 4 mm band and two 8 mm band) has been used to measure the plasma electron density on HL-1 tokamak device. The electron density approaching to 5 x 10 13 cm -3 is measured by a 2 mm band microwave interferometer. In the determinable range, the electron density profile in the cross-section on HL-1 device has been measured by this interferometer. A microcomputer data processing system is also developed

  19. Incineration of alpha-active solid waste by microwaves

    Energy Technology Data Exchange (ETDEWEB)

    Mallik, G K; Bhargava, V K; Kamath, H S; Purushotham, D S.C. [Bhabha Atomic Research Centre, Tarapur (India). Advanced Fuel Fabrication Facility

    1996-12-31

    The conventional techniques for treatment of alpha-active compressible solid waste involve incineration using electrically heated incinerators and subsequent recovery of special nuclear materials (SNM) from the ash by acid leaching. A microwave incineration followed by microwave digestion and SNM recovery from ash has specific advantages from maintenance and productivity consideration. The paper describes a preliminary work carried out with simulated uranium containing compressible solid waste using microwave heating technique. (author). 3 refs., 1 tab.

  20. Influence of 2. 45 GHz microwave radiation on enzyme activity

    Energy Technology Data Exchange (ETDEWEB)

    Galvin, M J; Parks, D L; McRee, D I

    1981-05-01

    The in vitro activity of acetylcholinesterase and creatine phosphokinase was determined during in vitro exposure to 2.45 GHz microwave radiation. The enzyme activities were examined during exposure to microwave radiation at specific absorption rates (SAR) of 1, 10, 50, and 100 mW/g. These specific absorption rates had no effect on the activity of either enzyme when the temperature of the control and exposed samples were similar. These data demonstrate that the activity of these two enzymes is not affected by microwave radiation at the SARs and frequency employed in this study.

  1. Microwave-assisted green synthesis and antimicrobial activity of ...

    African Journals Online (AJOL)

    Microwave-assisted green synthesis and antimicrobial activity of silver nanoparticles derived from a ... Journal Home > Vol 16, No 12 (2017) > ... has been prepared by a simple, eco-friendly, cost-effective, rapid green chemistry methodology.

  2. Microwave absorbing properties of activated carbon fibre polymer ...

    Indian Academy of Sciences (India)

    cations in the field of radar and electromagnetic compatibility. (Singh et al ... fibres have irregular-shaped cross sections (shown in fig- ure 1) ... Microwave absorbing properties of activated carbon fibre polymer composites. 77. 2. 4. 6. 8. 10. 12.

  3. Microwave engineering

    CERN Document Server

    Pozar, David M

    2012-01-01

    The 4th edition of this classic text provides a thorough coverage of RF and microwave engineering concepts, starting from fundamental principles of electrical engineering, with applications to microwave circuits and devices of practical importance.  Coverage includes microwave network analysis, impedance matching, directional couplers and hybrids, microwave filters, ferrite devices, noise, nonlinear effects, and the design of microwave oscillators, amplifiers, and mixers. Material on microwave and RF systems includes wireless communications, radar, radiometry, and radiation hazards. A large

  4. Microwave engineering concepts and fundamentals

    CERN Document Server

    Khan, Ahmad Shahid

    2014-01-01

    Detailing the active and passive aspects of microwaves, Microwave Engineering: Concepts and Fundamentals covers everything from wave propagation to reflection and refraction, guided waves, and transmission lines, providing a comprehensive understanding of the underlying principles at the core of microwave engineering. This encyclopedic text not only encompasses nearly all facets of microwave engineering, but also gives all topics—including microwave generation, measurement, and processing—equal emphasis. Packed with illustrations to aid in comprehension, the book: •Describes the mathematical theory of waveguides and ferrite devices, devoting an entire chapter to the Smith chart and its applications •Discusses different types of microwave components, antennas, tubes, transistors, diodes, and parametric devices •Examines various attributes of cavity resonators, semiconductor and RF/microwave devices, and microwave integrated circuits •Addresses scattering parameters and their properties, as well a...

  5. Study of the background noise in microwave GaAsFET devices

    International Nuclear Information System (INIS)

    Serrano S, A.

    1984-01-01

    One of the most important properties of the gallium arsenide field effect transistor is its low noise figure in the microwave frequency range (approx. 1 dB, 4 GHz). The applications of this device in components and systems in the high frequency range require analysis of background noise in terms of basic static and dynamic properties of the device. The purpose of this paper is to review GaAsFET noise properties; from this review, a description of precise noise measurement techniques is made. Some experimental and theoretical results on the minimum noise figure are shown for several GaAsFET devices. (author)

  6. An active magnetic regenerator device

    DEFF Research Database (Denmark)

    2015-01-01

    A rotating active magnetic regenerator (AMR) device comprising two or more regenerator beds, a magnet arrangement and a valve arrangement. The valve arrangement comprises a plurality of valve elements arranged substantially immovably with respect to the regenerator beds along a rotational direction...

  7. Densification of LSGM electrolytes using activated microwave sintering

    Science.gov (United States)

    Kesapragada, S. V.; Bhaduri, S. B.; Bhaduri, S.; Singh, P.

    Lanthanum gallate doped with alkaline rare earths (LSGM) powders were densified using an activated microwave sintering process for developing a dense stable electrolyte layer for applications in intermediate temperature-solid oxide fuel cells (IT-SOFCs). Due to heat generation in situ, the process of sintering gets activated with faster kinetics compared to a conventional sintering process. The effect of various microwave process parameters on the microstructure and phase formation was studied. The sintered pellets were characterized using scanning electron microscopy-energy dispersive analysis (SEM-EDAX), and X-ray diffraction (XRD). The density of LSGM pellets microwave sintered at 1350 °C for 20 min is greater than 95% theoretical density with a fine grained microstructure (˜2-3 μm) and without the presence of other phase(s).

  8. Microwave oven fabricated hybrid memristor devices for non-volatile memory storage

    International Nuclear Information System (INIS)

    Verrelli, E; Gray, R J; O’Neill, M; Kemp, N T; Kelly, S M

    2014-01-01

    Novel hybrid non-volatile memories made using an ultra-fast microwave heating method are reported for the first time. The devices, consisting of aligned ZnO nanorods embedded in poly (methyl methacrylate), require no forming step and exhibit reliable and reproducible bipolar resistive switching at low voltages and with low power usage. We attribute these properties to a combination of the high aspect ratio of the nanorods and the polymeric hybrid structure of the device. The extremely easy, fast and low-cost solution based method of fabrication makes possible the simple and quick production of cheap memory cells. (paper)

  9. Superconductivity applications for infrared and microwave devices II; Proceedings of the Meeting, Orlando, FL, Apr. 4, 5, 1991

    Science.gov (United States)

    Heinen, Vernon O.; Bhasin, Kul B.

    Topics discussed include thin-film technology, microwave transmission lines and resonators, microwave devices and circuits, infrared detectors and bolometers, and superconducting junctions. Papers are presented on possible enhancement in bolometric response using free-standing film of YBa2Cu3O(x), aging and surface instability in high-Tc superconductors, epitaxial Tl2Ba2CaCu2O8 thin films on LaAlO3 and their microwave device properties, the performance of stripline resonators using sputtered YBCO films, and a coplanar waveguide microwave filter of YBa2Cu3O7. Attention is also given to the performance characteristics of Y-Ba-Cu-O microwave superconducting detectors, high-Tc bolometer developments for planetary missions, infrared detectors from YBaCuO thin films, high-temperature superconductor junction technology, and submillimeter receiver components using superconducting tunnel junctions. (For individual items see A93-27244 to A93-27248)

  10. Response surface optimisation for activation of bentonite with microwave irradiation

    Directory of Open Access Journals (Sweden)

    Rožić Ljiljana S.

    2011-01-01

    Full Text Available In this study, the statistical design of the experimental method was applied on the acid activation process of bentonite with microwave irradiation. The influence of activation parameters (time, acid normality and microwave heating power on the selected process response of the activated bentonite samples was studied. The specific surface area was chosen for the process response, because the chemical, surface and structural properties of the activated clay determine and limit its potential applications. The relationship of various process parameters with the specific surface area of bentonite was examined. A mathematical model was developed using a second-order response surface model (RSM with a central composite design incorporating the above mentioned process parameters. The mathematical model developed helped in predicting the variation in specific surface area of activated bentonite with time (5-21 min, acid normality (2-7 N and microwave heating power (63-172 W. The calculated regression models were found to be statistically significant at the required range and presented little variability. Furthermore, high values of R2 (0.957 and R2 (adjusted (0.914 indicate a high dependence and correlation between the observed and the predicted values of the response. These high values also indicate that about 96% of the result of the total variation can be explained by this model. In addition, the model shows that increasing the time and acid normality improves the textural properties of bentonites, resulting in increased specific surface area. This model also can be useful for setting an optimum value of the activation parameters for achieving the maximum specific surface area. An optimum specific surface area of 142 m2g-1 was achieved with an acid normality of 5.2 N, activation time of 7.38 min and microwave power of 117 W. Acid activation of bentonite was found to occur faster with microwave irradiation than with conventional heating. Microwave

  11. Assessment of complex microwaves occupational exposure in radar maintenance activity

    International Nuclear Information System (INIS)

    Danulescu, R.

    1996-01-01

    The modern of the society teas determined the increase of thousand times greater than the natural fond of the humankind exposure to a complex combination of electromagnetic man-made fields and radiations of extremely various strength and frequencies. A special contribution to this environmental change has had in the last decade the appearance and the explosive development of the microwaves generating appliances such as radars used in a great variety of military and civilian applications and which essentially contributes to the electromagnetic pollution. In the above mentioned content which firstly interests the occupational environment, it is necessary to improve the exposure limits, as well as, the emission standards, in order to better protect the human health and well-being. From this point of view, the estimation of the microwave occupational exposure risk constitutes, alongside the health status assessment, one of the priorities of the Occupational Health because the theoretical and practical problems related to the bioeffects of this kind of radiations are far to be clarified. Our study has been carried out in a factory where one performs research, production and especially maintenance of microwaves generating devices. (author)

  12. Rapid PCR amplification using a microfluidic device with integrated microwave heating and air impingement cooling.

    Science.gov (United States)

    Shaw, Kirsty J; Docker, Peter T; Yelland, John V; Dyer, Charlotte E; Greenman, John; Greenway, Gillian M; Haswell, Stephen J

    2010-07-07

    A microwave heating system is described for performing polymerase chain reaction (PCR) in a microfluidic device. The heating system, in combination with air impingement cooling, provided rapid thermal cycling with heating and cooling rates of up to 65 degrees C s(-1) and minimal over- or under-shoot (+/-0.1 degrees C) when reaching target temperatures. In addition, once the required temperature was reached it could be maintained with an accuracy of +/-0.1 degrees C. To demonstrate the functionality of the system, PCR was successfully performed for the amplification of the Amelogenin locus using heating rates and quantities an order of magnitude faster and smaller than current commercial instruments.

  13. Microwave synthesized nanostructured TiO2-activated carbon composite electrodes for supercapacitor

    International Nuclear Information System (INIS)

    Selvakumar, M.; Bhat, D. Krishna

    2012-01-01

    Highlights: ► Nanostructure TiO 2 has been prepared by a microwave assisted synthesis method. ► Microwave irradiation was varied with time duration on the formation of nanoparticles. ► TiO 2 -activate carbon show very good specific capacitance for supercapacitor. ► Electrochemical properties were studied on electroanalytical techniques. - Abstract: Electrochemical properties of a supercapacitor based on nanocomposite electrodes of activated carbon with TiO 2 nano particles synthesized by a microwave method have been determined. The TiO 2 /activated carbon nanocomposite electrode with a composition of 1:3 showed a specific capacitance 92 Fg −1 . The specific capacitance of the electrode decreased with increase in titanium dioxide content. The p/p symmetrical supercapacitor fabricated with TiO 2 /activated carbon composite electrodes showed a specific capacitance of 122 Fg −1 . The electrochemical behavior of the neat TiO 2 nanoparticles has also been studied for comparison purpose. The galvanostatic charge–discharge test of the fabricated supercapacitor showed that the device has good coulombic efficiency and cycle life. The specific capacitance of the supercapacitor was stable up to 5000 cycles at current densities of 2, 4, 6 and 7 mA cm −2 .

  14. Microwave discharge electrodeless lamps (MDEL). Part IV. Novel self-ignition system incorporating metallic microwave condensing cones to activate MDELs in photochemical reactions.

    Science.gov (United States)

    Horikoshi, Satoshi; Tsuchida, Akihiro; Sakai, Hideki; Abe, Masahiko; Sato, Susumu; Serpone, Nick

    2009-11-01

    A metallic condensing cone that concentrates microwave radiation (equivalent to an optical lens) has been developed and used as part of a system to activate a microwave discharge electrodeless lamp (MDEL) in the oxidative treatment of wastewaters by aiding the novel self-ignition of the lamp on irradiation at low microwave power levels. This approach to self-ignition can potentially lead to considerable energy savings in such treatments. System performance was examined for the ignition power of microwaves of such MDEL devices in water, whose usefulness was assessed by investigating the photolytic transformation of aqueous solutions of representatives of three classes of contaminants: chlorinated phenols, herbicides and endocrine disruptors, specifically 4-chlorophenol (4-CP), 2,4-dichlorophenoxyacetic acid (2,4-D) and 4,4'-isopropylidenediphenol (bisphenol-A; BPA), respectively, taken as model wastewaters in air-equilibrated, in oxygen-saturated and in TiO2-containing aqueous media. The results are discussed in terms of the dynamics of the photo-induced degradation processes.

  15. Measure of enzymatic activity coincident with 2450 MHz microwave exposure

    Energy Technology Data Exchange (ETDEWEB)

    Ward, T R; Allis, J W; Elder, J A

    1975-09-01

    Enzyme preparations were exposed to microwave radiation at 2450 MHz and enzymatic activity was simultaneously monitored spectrophotometrically with a crossed-beam exposure detection system. Enzymes studied were glucose 6-phosphate dehydrogenase from human red blood cells and yeast, adenylate kinase from rat liver mitochondria and rabbit muscle, and rat liver microsomal NADPH cytochrome c reductase. No difference was found between the specific activity at 25/sup 0/C of unirradiated controls and enzyme preparations irradiated at an absorbed dose rate of 42 W/kg.

  16. Radiofrequency and microwave tumor ablation in patients with implanted cardiac devices: Is it safe?

    Energy Technology Data Exchange (ETDEWEB)

    Skonieczki, Brendan D., E-mail: bskonieczki@lifespan.org [Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903 (United States); Wells, Catherine, E-mail: cwells1@bidmc.harvard.edu [Department of Radiology, Harvard Medical School/Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215 (United States); Wasser, Elliot J., E-mail: ewasser@lifespan.org [Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903 (United States); Dupuy, Damian E., E-mail: ddupuy@lifespan.org [Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903 (United States)

    2011-09-15

    Purpose: To identify malfunction of implanted cardiac devices during or after thermal ablation of tumors in lung, kidney, liver or bone, using radiofrequency (RF) or microwave (MW) energy. Materials and methods: After providing written consent, 19 patients (15 men and 4 women; mean age 78 years) with pacemakers or pacemaker/defibrillators underwent 22 CT image-guided percutaneous RF or MW ablation of a variety of tumors. Before and after each procedure, cardiac devices were interrogated and reprogrammed by a trained cardiac electrophysiology fellow. Possible pacer malfunctions included abnormalities on electrocardiographic (EKG) monitoring and alterations in device settings. Our institutional review board approved this Health Insurance Portability and Accountability Act-compliant study. Informed consent for participation in this retrospective study was deemed unnecessary by our review board. Results: During 20 of 22 sessions, no abnormalities were identified in continuous, EKG tracings or pacemaker functions. However, in two sessions significant changes, occurred in pacemaker parameters: inhibition of pacing during RF application in one, session and resetting of mode by RF energy in another session. These changes did not, result in hemodynamic instability of either patient. MW ablation was not associated with, any malfunction. In all 22 sessions, pacemakers were undamaged and successfully reset to original parameters. Conclusion: RF or MW ablation of tumors in liver, kidney, bone and lung can be performed safely in patients with permanent intra-cardiac devices, but careful planning between radiology and cardiology is essential to avoid adverse outcomes.

  17. Microwave heating device for internal heating convection experiments, applied to Earth's mantle dynamics.

    Science.gov (United States)

    Surducan, E; Surducan, V; Limare, A; Neamtu, C; Di Giuseppe, E

    2014-12-01

    We report the design, construction, and performances of a microwave (MW) heating device for laboratory experiments with non-contact, homogeneous internal heating. The device generates MW radiation at 2.47 GHz from a commercial magnetron supplied by a pulsed current inverter using proprietary, feedback based command and control hardware and software. Specially designed MW launchers direct the MW radiation into the sample through a MW homogenizer, devised to even the MW power distribution into the sample's volume. An adjustable MW circuit adapts the MW generator to the load (i.e., the sample) placed in the experiment chamber. Dedicated heatsinks maintain the MW circuits at constant temperature throughout the experiment. Openings for laser scanning for image acquisition with a CCD camera and for the cooling circuits are protected by special MW filters. The performances of the device are analyzed in terms of heating uniformity, long term output power stability, and load matching. The device is used for small scale experiments simulating Earth's mantle convection. The 30 × 30 × 5 cm(3) convection tank is filled with a water‑based viscous fluid. A uniform and constant temperature is maintained at the upper boundary by an aluminum heat exchanger and adiabatic conditions apply at the tank base. We characterize the geometry of the convective regime as well as its bulk thermal evolution by measuring the velocity field by Particle Image Velocimetry and the temperature field by using Thermochromic Liquid Crystals.

  18. Microwave heating device for internal heating convection experiments, applied to Earth's mantle dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Surducan, E.; Surducan, V.; Neamtu, C., E-mail: camelia.neamtu@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies (INCDTIM), 67-103 Donat St., 400293, Cluj‑Napoca (Romania); Limare, A.; Di Giuseppe, E. [Institut de Physique du Globe de Paris (IPGP), Univ. Paris Diderot, UMR CNRS 7154, 1 rue Jussieu, 75005, Paris (France)

    2014-12-15

    We report the design, construction, and performances of a microwave (MW) heating device for laboratory experiments with non-contact, homogeneous internal heating. The device generates MW radiation at 2.47 GHz from a commercial magnetron supplied by a pulsed current inverter using proprietary, feedback based command and control hardware and software. Specially designed MW launchers direct the MW radiation into the sample through a MW homogenizer, devised to even the MW power distribution into the sample's volume. An adjustable MW circuit adapts the MW generator to the load (i.e., the sample) placed in the experiment chamber. Dedicated heatsinks maintain the MW circuits at constant temperature throughout the experiment. Openings for laser scanning for image acquisition with a CCD camera and for the cooling circuits are protected by special MW filters. The performances of the device are analyzed in terms of heating uniformity, long term output power stability, and load matching. The device is used for small scale experiments simulating Earth's mantle convection. The 30 × 30 × 5 cm{sup 3} convection tank is filled with a water‑based viscous fluid. A uniform and constant temperature is maintained at the upper boundary by an aluminum heat exchanger and adiabatic conditions apply at the tank base. We characterize the geometry of the convective regime as well as its bulk thermal evolution by measuring the velocity field by Particle Image Velocimetry and the temperature field by using Thermochromic Liquid Crystals.

  19. Preparation and characterization of activated carbon from pistachio nut shells via microwave-induced chemical activation

    International Nuclear Information System (INIS)

    Foo, K.Y.; Hameed, B.H.

    2011-01-01

    In this work, pistachio nut shell, a biomass residue abundantly available from the pistachio nut processing industries, was utilized as a feedstock for the preparation of activated carbon (PSAC) via microwave assisted KOH activation. The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. The porosity, functional and surface chemistry were featured by means of low temperature nitrogen adsorption, scanning electron microscopy and Fourier transform infrared spectroscopy. Result showed that the BET surface area, Langmuir surface area, and total pore volume of PSAC were 700.53 m 2 g -1 , 1038.78 m 2 g -1 and 0.375 m 3 g -1 , respectively. The adsorptive property of PSAC was tested using methylene blue dye as the targeted adsorbate. Equilibrium data was best fitted by the Langmuir isotherm model, showing a monolayer adsorption capacity of 296.57 mg g -1 . The study revealed the potentiality of microwave-induced activation as a viable activation method. -- Highlights: → Pistachio nut shell activated carbon (PSAC) was prepared via microwave assisted KOH activation. → The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. → BET surface area of PSAC was 700.53 m 2 /g. → Monolayer adsorption capacity of PSAC for MB was 296.57 mg/g.

  20. Preparation and characterization of activated carbon from pistachio nut shells via microwave-induced chemical activation

    Energy Technology Data Exchange (ETDEWEB)

    Foo, K. Y. [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Hameed, B.H., E-mail: chbassim@eng.usm.my [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2011-07-15

    In this work, pistachio nut shell, a biomass residue abundantly available from the pistachio nut processing industries, was utilized as a feedstock for the preparation of activated carbon (PSAC) via microwave assisted KOH activation. The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. The porosity, functional and surface chemistry were featured by means of low temperature nitrogen adsorption, scanning electron microscopy and Fourier transform infrared spectroscopy. Result showed that the BET surface area, Langmuir surface area, and total pore volume of PSAC were 700.53 m{sup 2} g{sup -1}, 1038.78 m{sup 2} g{sup -1} and 0.375 m{sup 3} g{sup -1}, respectively. The adsorptive property of PSAC was tested using methylene blue dye as the targeted adsorbate. Equilibrium data was best fitted by the Langmuir isotherm model, showing a monolayer adsorption capacity of 296.57 mg g{sup -1}. The study revealed the potentiality of microwave-induced activation as a viable activation method. -- Highlights: {yields} Pistachio nut shell activated carbon (PSAC) was prepared via microwave assisted KOH activation. {yields} The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. {yields} BET surface area of PSAC was 700.53 m{sup 2}/g. {yields} Monolayer adsorption capacity of PSAC for MB was 296.57 mg/g.

  1. Production of activated carbon from peanut hill using phosphoric acid and microwave activation

    Directory of Open Access Journals (Sweden)

    Weerawat Clowutimon

    2015-06-01

    Full Text Available The optimum conditions for preparing activated carbon from peanut hulls by phosphoric acid and microwave activation were studied. Factors investigated in this study were temperature of carbonization at 300, 350, 400 and 450๐ C, and time of carbonization at 30, 60 and 90 minutes. The optimum yield was observed that carbonization temperature of 400๐ C and time at 60 minutes, respectively. The yield of charcoal was 39% and the f ix carbon was 69%. Then the charcoal was activated by phosphoric acid and microwave irradiation, respectively. The effect of the weight per volume ratios of charcoal to activating acid (1:1, 1:2 and 2:1(W/V, microwave power at (activated 300, 500 and 700 watts, and activated time (30, 60 and 90 seconds were studied. The results showed that the optimum conditions for activating peanut charcoal were 1:2 (W/V charcoal per activating acid, microwave power 700 watts for 90 seconds. The results yielding maximum surface area by BET method was 303.1 m2 /g and pore volume was 0.140 cm3 /g. An efficiency of maximum iodine adsorption was 418 mg iodine/g activated carbon. Comparing the adsorption efficiency of non- irradiated and irradiated activated carbon, the efficiency of irradiated activated carbon improved up to 31%, due to its larger surface area and pore volume.

  2. Crystal growth of hexaferrite architecture for magnetoelectrically tunable microwave semiconductor integrated devices

    Science.gov (United States)

    Hu, Bolin

    Hexaferrites (i.e., hexagonal ferrites), discovered in 1950s, exist as any one of six crystallographic structural variants (i.e., M-, X-, Y-, W-, U-, and Z-type). Over the past six decades, the hexaferrites have received much attention owing to their important properties that lend use as permanent magnets, magnetic data storage materials, as well as components in electrical devices, particularly those operating at RF frequencies. Moreover, there has been increasing interest in hexaferrites for new fundamental and emerging applications. Among those, electronic components for mobile and wireless communications especially incorporated with semiconductor integrated circuits at microwave frequencies, electromagnetic wave absorbers for electromagnetic compatibility, random-access memory (RAM) and low observable technology, and as composite materials having low dimensions. However, of particular interest is the magnetoelectric (ME) effect discovered recently in the hexaferrites such as SrScxFe12-xO19 (SrScM), Ba2--xSrxZn 2Fe12O22 (Zn2Y), Sr4Co2Fe 36O60 (Co2U) and Sr3Co2Fe 24O41 (Co2Z), demonstrating ferroelectricity induced by the complex internal alignment of magnetic moments. Further, both Co 2Z and Co2U have revealed observable magnetoelectric effects at room temperature, representing a step toward practical applications using the ME effect. These materials hold great potential for applications, since strong magnetoelectric coupling allows switching of the FE polarization with a magnetic field (H) and vice versa. These features could lead to a new type of storage devices, such as an electric field-controlled magnetic memory. A nanoscale-driven crystal growth of magnetic hexaferrites was successfully demonstrated at low growth temperatures (25--40% lower than the temperatures required often for crystal growth). This outcome exhibits thermodynamic processes of crystal growth, allowing ease in fabrication of advanced multifunctional materials. Most importantly, the

  3. Effects of low power microwave radiation on biological activity of Collagenase enzyme and growth rate of S. Cerevisiae yeast

    Science.gov (United States)

    Alsuhaim, Hamad S.; Vojisavljevic, Vuk; Pirogova, E.

    2013-12-01

    Recently, microwave radiation, a type/subset of non-ionizing electromagnetic radiation (EMR) has been widely used in industry, medicine, as well as food technology and mobile communication. Use of mobile phones is rapidly growing. Four years from now, 5.1 billion people will be mobile phone users around the globe - almost 1 billion more mobile users than the 4.3 billion people worldwide using them now. Consequently, exposure to weak radiofrequency/microwave radiation generated by these devices is markedly increasing. Accordingly, public concern about potential hazards on human health is mounting [1]. Thermal effects of radiofrequency/microwave radiation are very well-known and extensively studied. Of particular interest are non-thermal effects of microwave exposures on biological systems. Nonthermal effects are described as changes in cellular metabolism caused by both resonance absorption and induced EMR and are often accompanied by a specific biological response. Non-thermal biological effects are measurable changes in biological systems that may or may not be associated with adverse health effects. In this study we studied non-thermal effects of low power microwave exposures on kinetics of L-lactate dehydrogenase enzyme and growth rate of yeast Saccharomyces Cerevisiae strains type II. The selected model systems were continuously exposed to microwave radiation at the frequency of 968MHz and power of 10dBm using the designed and constructed (custom made) Transverse Electro-Magnetic (TEM) cell [2]. The findings reveal that microwave radiation at 968MHz and power of 10dBm inhibits L-lactate dehydrogenase enzyme activity by 26% and increases significantly (15%) the proliferation rate of yeast cells.

  4. Lower limit of intensity for the solar activity in microwaves

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, P; Iacomo, P Jr; Koppe, E H; dos Santos, P M; Schaal, R E [Universidade Mackenzie, Sao Paulo (Brazil). Centro de Radio-Astronomia e Astrofisica; Blakey, J R [Surrey Univ., Guildford (UK). Dept. of Physics

    1976-01-01

    The active region McMath 10433 has produced various flares and bursts in radio frequency in the beginning of july 1974. This region was scanned countinously in 22.2 GHz with a radio telescope showing a 4 min. arc beam, in various periods of the month. In comparison with the results simultaneously obtained with a normal solar radio telescope, in 7 GHz, it was verified that there is an important explosive activity in lower levels in the limit of detection of an usual patrolling instrument. The morphology of these events, in its progress in the time, is similar to that normaly known, and allowed, the re-interpretation of simple events. A completly new type of event was defined: the fast absorptions. The correlation of events in microwaves with 'SPA' recorded in 'VLF' propagation is also discussed.

  5. Superconductivity applications for infrared and microwave devices; Proceedings of the Meeting, Orlando, FL, Apr. 19, 20, 1990

    Science.gov (United States)

    Bhasin, Kul B.; Heinen, Vernon O.

    1990-10-01

    Various papers on superconductivity applications for IR and microwave devices are presented. The individual topics addressed include: pulsed laser deposition of Tl-Ca-Ba-Cu-O films, patterning of high-Tc superconducting thin films on Si substrates, IR spectra and the energy gap in thin film YBa2Cu3O(7-delta), high-temperature superconducting thin film microwave circuits, novel filter implementation utilizing HTS materials, high-temperature superconductor antenna investigations, high-Tc superconducting IR detectors, high-Tc superconducting IR detectors from Y-Ba-Cu-O thin films, Y-Ba-Cu0-O thin films as high-speed IR detectors, fabrication of a high-Tc superconducting bolometer, transition-edge microbolometer, photoresponse of YBa2Cu3O(7-delta) granular and epitaxial superconducting thin films, fast IR response of YBCO thin films, kinetic inductance effects in high-Tc microstrip circuits at microwave frequencies.

  6. Microwave activation of palladium nanoparticles for enhanced ethanol electrocatalytic oxidation reaction in alkaline medium

    CSIR Research Space (South Africa)

    Rohwer, MB

    2015-02-01

    Full Text Available in alkaline medium (in terms of high mass activity stability and fast reaction kinetics). The remarkable microwave-induced properties on the Pd catalyst promise to revolutionize the use of microwave for catalyst activation for enhanced heterogeneous catalysis...

  7. Roles of acid sphingomyelinase activation in neuronal cells apoptosis induced by microwave irradiation

    International Nuclear Information System (INIS)

    Zhang Lei; Xu Shangcheng; Zhang Guangbin; Yu Zhengping

    2009-01-01

    The present study is to examine the effect of microwave on acid sphingomyelinase (ASM) activity and expression, and to explore the role of ASM activation in neuronal cells apoptosis induced by microwave irradiation. Primary cultured hippocampal neurons were irradiated by 30 W/cm 2 microwave for 10 min, and ASM activity assay was used to investigate ASM activity alteration. RT-PCR and western blot were used to detect ASM mRNA and protein expression respectively. Apoptosis was observed by Hoechst 33342 fluorescence staining. ASM specific inhibitor imipramine was applied to inhibit ASM activation. It has been found that apoptosis rate of primary cultured hippocampal neurons increased significantly after microwave irradiation. ASM was activated while ASM mRNA and protein expression were upregulated in neurons after microwave irradiation. Pretreatment with imipramine could reverse neuronal apoptosis induced by microwave irradiation. Results show that microwave irradiation causes increment of ASM activation and expression and ASM activation is involved in microwave induced neuronal apoptosis. (authors)

  8. A passive and active microwave-vector radiative transfer (PAM-VRT) model

    International Nuclear Information System (INIS)

    Yang, Jun; Min, Qilong

    2015-01-01

    A passive and active microwave vector radiative transfer (PAM-VRT) package has been developed. This fast and accurate forward microwave model, with flexible and versatile input and output components, self-consistently and realistically simulates measurements/radiation of passive and active microwave sensors. The core PAM-VRT, microwave radiative transfer model, consists of five modules: gas absorption (two line-by-line databases and four fast models); hydrometeor property of water droplets and ice (spherical and nonspherical) particles; surface emissivity (from Community Radiative Transfer Model (CRTM)); vector radiative transfer of successive order of scattering (VSOS); and passive and active microwave simulation. The PAM-VRT package has been validated against other existing models, demonstrating good accuracy. The PAM-VRT not only can be used to simulate or assimilate measurements of existing microwave sensors, but also can be used to simulate observation results at some new microwave sensors. - Highlights: • A novel microwave vector radiative transfer model is developed. • It can simulate passive and active microwave radiative transfer simultaneously. • It can be applied to simulate measurements for different types of viewing geometry. • The accuracy of this model has been validated against other existing models

  9. Multi-band Microwave Antennas and Devices based on Generalized Negative-Refractive-Index Transmission Lines

    Science.gov (United States)

    Ryan, Colan Graeme Matthew

    Focused on the quad-band generalized negative-refractive-index transmission line (G-NRI-TL), this thesis presents a variety of novel printed G-NRI-TL multi-band microwave device and antenna prototypes. A dual-band coupled-line coupler, an all-pass G-NRI-TL bridged-T circuit, a dual-band metamaterial leaky-wave antenna, and a multi-band G-NRI-TL resonant antenna are all new developments resulting from this research. In addition, to continue the theme of multi-band components, negative-refractive-index transmission lines are used to create a dual-band circularly polarized transparent patch antenna and a two-element wideband decoupled meander antenna system. High coupling over two independently-specified frequency bands is the hallmark of the G-NRI-TL coupler: it is 0.35lambda0 long but achieves approximately -3 dB coupling over both bands with a maximum insertion loss of 1 dB. This represents greater design flexibility than conventional coupled-line couplers and less loss than subsequent G-NRI-TL couplers. The single-ended bridged-T G-NRI-TL offers a metamaterial unit cell with an all-pass magnitude response up to 8 GHz, while still preserving the quad-band phase response of the original circuit. It is shown how the all-pass response leads to wider bandwidths and improved matching in quad-band inverters, power dividers, and hybrid couplers. The dual-band metamaterial leaky-wave antenna presented here was the first to be reported in the literature, and it allows broadside radiation at both 2 GHz and 6 GHz without experiencing the broadside stopband common to conventional periodic antennas. Likewise, the G-NRI-TL resonant antenna is the first reported instance of such a device, achieving quad-band operation between 2.5 GHz and 5.6 GHz, with a minimum radiation efficiency of 80%. Negative-refractive-index transmission line loading is applied to two devices: an NRI-TL meander antenna achieves a measured 52% impedance bandwidth, while a square patch antenna incorporates

  10. A method for building low loss multi-layer wiring for superconducting microwave devices

    Science.gov (United States)

    Dunsworth, A.; Barends, R.; Chen, Yu; Chen, Zijun; Chiaro, B.; Fowler, A.; Foxen, B.; Jeffrey, E.; Kelly, J.; Klimov, P. V.; Lucero, E.; Mutus, J. Y.; Neeley, M.; Neill, C.; Quintana, C.; Roushan, P.; Sank, D.; Vainsencher, A.; Wenner, J.; White, T. C.; Neven, H.; Martinis, John M.; Megrant, A.

    2018-02-01

    Complex integrated circuits require multiple wiring layers. In complementary metal-oxide-semiconductor processing, these layers are robustly separated by amorphous dielectrics. These dielectrics would dominate energy loss in superconducting integrated circuits. Here, we describe a procedure that capitalizes on the structural benefits of inter-layer dielectrics during fabrication and mitigates the added loss. We use a deposited inter-layer dielectric throughout fabrication and then etch it away post-fabrication. This technique is compatible with foundry level processing and can be generalized to make many different forms of low-loss wiring. We use this technique to create freestanding aluminum vacuum gap crossovers (airbridges). We characterize the added capacitive loss of these airbridges by connecting ground planes over microwave frequency λ/4 coplanar waveguide resonators and measuring resonator loss. We measure a low power resonator loss of ˜3.9 × 10-8 per bridge, which is 100 times lower than that of dielectric supported bridges. We further characterize these airbridges as crossovers, control line jumpers, and as part of a coupling network in gmon and fluxmon qubits. We measure qubit characteristic lifetimes (T1s) in excess of 30 μs in gmon devices.

  11. 1800MHz Microwave Induces p53 and p53-Mediated Caspase-3 Activation Leading to Cell Apoptosis In Vitro.

    Directory of Open Access Journals (Sweden)

    Fuqiang Xing

    Full Text Available Recent studies have reported that exposure of mammalian cells to microwave radiation may have adverse effects such as induction of cell apoptosis. However, the molecular mechanisms underlying microwave induced mammalian cell apoptosis are not fully understood. Here, we report a novel mechanism: exposure to 1800MHz microwave radiation induces p53-dependent cell apoptosis through cytochrome c-mediated caspase-3 activation pathway. We first measured intensity of microwave radiation from several electronic devices with an irradiation detector. Mouse NIH/3T3 and human U-87 MG cells were then used as receivers of 1800MHz electromagnetic radiation (EMR at a power density of 1209 mW/m2. Following EMR exposure, cells were analyzed for viability, intracellular reactive oxygen species (ROS generation, DNA damage, p53 expression, and caspase-3 activity. Our analysis revealed that EMR exposure significantly decreased viability of NIH/3T3 and U-87 MG cells, and increased caspase-3 activity. ROS burst was observed at 6 h and 48 h in NIH/3T3 cells, while at 3 h in U-87 MG cells. Hoechst 33258 staining and in situ TUNEL assay detected that EMR exposure increased DNA damage, which was significantly restrained in the presence of N-acetyl-L-cysteine (NAC, an antioxidant. Moreover, EMR exposure increased the levels of p53 protein and p53 target gene expression, promoted cytochrome c release from mitochondrion, and increased caspase-3 activity. These events were inhibited by pretreatment with NAC, pifithrin-α (a p53 inhibitor and caspase inhibitor. Collectively, our findings demonstrate, for the first time, that 1800MHz EMR induces apoptosis-related events such as ROS burst and more oxidative DNA damage, which in turn promote p53-dependent caspase-3 activation through release of cytochrome c from mitochondrion. These findings thus provide new insights into physiological mechanisms underlying microwave-induced cell apoptosis.

  12. Active mems microbeam device for gas detection

    KAUST Repository

    Bouchaala, Adam M.; Jaber, Nizar; Younis, Mohammad I.

    2017-01-01

    Sensors and active switches for applications in gas detection and other fields are described. The devices are based on the softening and hardening nonlinear response behaviors of microelectromechanical systems (MEMS) clamped-clamped microbeams

  13. New Potentially Active Pyrazinamide Derivatives Synthesized Under Microwave Conditions

    Directory of Open Access Journals (Sweden)

    Ondrej Jandourek

    2014-07-01

    Full Text Available A series of 18 N-alkyl substituted 3-aminopyrazine-2-carboxamides was prepared in this work according to previously experimentally set and proven conditions using microwave assisted synthesis methodology. This approach for the aminodehalogenation reaction was chosen due to higher yields and shorter reaction times compared to organic reactions with conventional heating. Antimycobacterial, antibacterial, antifungal and photosynthetic electron transport (PET inhibiting in vitro activities of these compounds were investigated. Experiments for the determination of lipophilicity were also performed. Only a small number of substances with alicyclic side chain showed activity against fungi which was the same or higher than standards and the biological efficacy of the compounds increased with rising lipophilicity. Nine pyrazinamide derivatives also inhibited PET in spinach chloroplasts and the IC50 values of these compounds varied in the range from 14.3 to 1590.0 μmol/L. The inhibitory activity was connected not only with the lipophilicity, but also with the presence of secondary amine fragment bounded to the pyrazine ring. Structure-activity relationships are discussed as well.

  14. Active mems microbeam device for gas detection

    KAUST Repository

    Bouchaala, Adam M.

    2017-10-05

    Sensors and active switches for applications in gas detection and other fields are described. The devices are based on the softening and hardening nonlinear response behaviors of microelectromechanical systems (MEMS) clamped-clamped microbeams. In that context, embodiments of gas-triggered MEMS microbeam sensors and switches are described. The microbeam devices can be coated with a Metal-Organic Framework to achieve high sensitivity. For gas sensing, an amplitude-based tracking algorithm can be used to quantify an amount of gas captured by the devices according to frequency shift. Noise analysis is also conducted according to the embodiments, which shows that the microbeam devices have high stability against thermal noise. The microbeam devices are also suitable for the generation of binary sensing information for alarming, for example.

  15. High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

    National Research Council Canada - National Science Library

    Wilson, Clay

    2006-01-01

    .... This method is called High Power Microwave (HPM). Several nations, including sponsors of terrorism, may currently have a capability to use EMP as a weapon for cyberterrorism to disrupt communications and other parts of the U.S...

  16. High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

    National Research Council Canada - National Science Library

    Wilson, Clay

    2005-01-01

    .... This method is called High Power Microwave (HPM). Several nations, including reported sponsors of terrorism, may currently have a capability to use EMP as a weapon to disrupt communications and other parts of the U.S...

  17. Optical emission spectroscopy for quantification of ultraviolet radiations and biocide active species in microwave argon plasma jet at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Wattieaux, G., E-mail: gaetan.wattieaux@laplace.univ-tlse.fr; Yousfi, M.; Merbahi, N.

    2013-11-01

    This work deals with absorption and mainly emission spectrometry of a microwave induced surfatron plasma jet launched in ambient air and using an Argon flow carrier gas. The Ar flow rate varies between 1 and 3 L/min and the microwave power between 40 and 60 W. The analysis of the various spectra has led to the determination of the ozone and atomic oxygen concentrations, ultraviolet (UV) irradiance separating UVA, UVB and UVC, gas temperature, plasma electron density and excitation temperature. Most of these diagnostics are spatially resolved along the plasma jet axis. It is shown more particularly that rotational temperature obtained from OH(A-X) spectra ranges between 800 K to 1000 K while the apparent temperature of the plasma jet remains lower than about 325 K which is compatible with biocide treatment without significant thermal effect. The electron density reaches 1.2 × 10{sup 14} cm{sup −3}, the excitation temperature is about 4000 K, the UVC radiation represents only 5% of the UV radiations emitted by the device, the ozone concentration is found to reach 88 ± 27 ppm in the downstream part of the plasma jet at a distance of 30 mm away from the quartz tube outlet of the surfatron and the atomic oxygen concentration lies between 10 and 80 ppm up to a distance of 20 mm away from the quartz tube outlet. Ozone is identified as the main germicidal active species produced by the device since its concentration is in accordance with bacteria inactivation durations usually reported using such plasma devices. Human health hazard assessment is carried out all along this study since simple solutions are reminded to respect safety standards for exposures to ozone and microwave leakage. In this study, an air extraction unit is used and a Faraday cage is set around the quartz tube of the surfatron and the plasma jet. These solutions should be adopted by users of microwave induced plasma in open air conditions because according to the literature, this is not often the

  18. Optical emission spectroscopy for quantification of ultraviolet radiations and biocide active species in microwave argon plasma jet at atmospheric pressure

    International Nuclear Information System (INIS)

    Wattieaux, G.; Yousfi, M.; Merbahi, N.

    2013-01-01

    This work deals with absorption and mainly emission spectrometry of a microwave induced surfatron plasma jet launched in ambient air and using an Argon flow carrier gas. The Ar flow rate varies between 1 and 3 L/min and the microwave power between 40 and 60 W. The analysis of the various spectra has led to the determination of the ozone and atomic oxygen concentrations, ultraviolet (UV) irradiance separating UVA, UVB and UVC, gas temperature, plasma electron density and excitation temperature. Most of these diagnostics are spatially resolved along the plasma jet axis. It is shown more particularly that rotational temperature obtained from OH(A-X) spectra ranges between 800 K to 1000 K while the apparent temperature of the plasma jet remains lower than about 325 K which is compatible with biocide treatment without significant thermal effect. The electron density reaches 1.2 × 10 14 cm −3 , the excitation temperature is about 4000 K, the UVC radiation represents only 5% of the UV radiations emitted by the device, the ozone concentration is found to reach 88 ± 27 ppm in the downstream part of the plasma jet at a distance of 30 mm away from the quartz tube outlet of the surfatron and the atomic oxygen concentration lies between 10 and 80 ppm up to a distance of 20 mm away from the quartz tube outlet. Ozone is identified as the main germicidal active species produced by the device since its concentration is in accordance with bacteria inactivation durations usually reported using such plasma devices. Human health hazard assessment is carried out all along this study since simple solutions are reminded to respect safety standards for exposures to ozone and microwave leakage. In this study, an air extraction unit is used and a Faraday cage is set around the quartz tube of the surfatron and the plasma jet. These solutions should be adopted by users of microwave induced plasma in open air conditions because according to the literature, this is not often the case

  19. Neutronics activities for next generation devices

    International Nuclear Information System (INIS)

    Gohar, Y.

    1985-01-01

    Neutronic activities for the next generation devices are the subject of this paper. The main activities include TFCX and FPD blanket/shield studies, neutronic aspects of ETR/INTOR critical issues, and neutronics computational modules for the tokamak system code and tandem mirror reactor system code. Trade-off analyses, optimization studies, design problem investigations and computational models development for reactor parametric studies carried out for these activities are summarized

  20. A Synthesizable Multicore Platform for Microwave Imaging

    DEFF Research Database (Denmark)

    Schleuniger, Pascal; Karlsson, Sven

    2014-01-01

    Active microwave imaging techniques such as radar and tomography are used in a wide range of medical, industrial, scientific, and military applications. Microwave imaging devices emit radio waves and process their reflections to reconstruct an image. However, data processing remains a challenge...

  1. Mobility devices to promote activity and participation

    DEFF Research Database (Denmark)

    Salminen, Anna-Liisa; Brandt, Ase; Samuelsson, Kersti A M

    2009-01-01

    were included if they covered both baseline and follow-up data and focused on activity and participation. Study participants had to be aged over 18 years with mobility limitations. Mobility device interventions encompassed crutches, walking frames, rollators, manual wheelchairs and powered wheelchairs......, and 3 follow-up studies that included before and after data. Two studies dealt with the effects of powered wheelchair interventions and the other studies with various other types of mobility device. Two studies were of high, internal and external methodological quality. Interventions were found......OBJECTIVE: To determine the effectiveness of mobility device interventions in terms of activity and participation for people with mobility limitations. DESIGN: Systematic review. Search of 7 databases during the period 1996 to 2008. METHODS: Controlled studies and non-controlled follow-up studies...

  2. APS-Workshop on Characterization of MMIC (Monolithic Microwave Integrated Circuit) Devices for Array Antenna

    Science.gov (United States)

    Smetana, Jerry (Editor); Mittra, Raj (Editor); Laprade, Nick; Edward, Bryan; Zaghloul, Amir

    1987-01-01

    The IEEE AP-S ADCOM is attempting to expand its educational, tutorial and information exchange activities as a further benefit to all members. To this end, ADCOM will be forming specialized workshops on topics of interest to its members. The first such workshop on Characterization and Packaging of MMIC Devices for Array Antennas was conceived. The workshop took place on June 13, 1986 as part of the 1986 International Symposium sponsored by IEEE AP-S and URSI in Philadelphia, PA, June 9-13, 1986. The workshop was formed to foster the interchange of ideas among MMIC device users and to provide a forum to collect and focus information among engineers experienced and interested in the topic. After brief presentations by the panelists and comments from attendees on several subtopics, the group was divided into working committees. Each committee evaluated and made recommendations on one of the subtopics.

  3. Microwave, EUV, and X-ray observations of active region loops and filaments

    International Nuclear Information System (INIS)

    Schmahl, E.

    1980-01-01

    Until the advent of X-ray and EUV observations of coronal structures, radio observers were forced to rely on eclipse and coronagraph observations in white light and forbidden coronal lines for additional diagnostics of the high temperature microwave sources. While these data provided enough material for theoretical insight into the physics of active regions, there was no way to make direct, simultaneous comparison of coronal structures on the disk as seen at microwave and optical wavelengths. This is now possible, and therefore the author summarizes the EUV and X-ray observations indicating at each point the relevance to microwaves. (Auth.)

  4. Advances on simultaneous desulfurization and denitrification using activated carbon irradiated by microwaves.

    Science.gov (United States)

    Ma, Shuang-Chen; Gao, Li; Ma, Jing-Xiang; Jin, Xin; Yao, Juan-Juan; Zhao, Yi

    2012-06-01

    This paper describes the research background and chemistry of desulfurization and denitrification technology using microwave irradiation. Microwave-induced catalysis combined with activated carbon adsorption and reduction can reduce nitric oxide to nitrogen and sulfur dioxide to sulfur from flue gas effectively. This paper also highlights the main drawbacks of this technology and discusses future development trends. It is reported that the removal of sulfur dioxide and nitric oxide using microwave irradiation has broad prospects for development in the field of air pollution control.

  5. Active/passive microwave sensor comparison of MIZ-ice concentration estimates. [Marginal Ice Zone (MIZ)

    Science.gov (United States)

    Burns, B. A.; Cavalieri, D. J.; Keller, M. R.

    1986-01-01

    Active and passive microwave data collected during the 1984 summer Marginal Ice Zone Experiment in the Fram Strait (MIZEX 84) are used to compare ice concentration estimates derived from synthetic aperture radar (SAR) data to those obtained from passive microwave imagery at several frequencies. The comparison is carried out to evaluate SAR performance against the more established passive microwave technique, and to investigate discrepancies in terms of how ice surface conditions, imaging geometry, and choice of algorithm parameters affect each sensor. Active and passive estimates of ice concentration agree on average to within 12%. Estimates from the multichannel passive microwave data show best agreement with the SAR estimates because the multichannel algorithm effectively accounts for the range in ice floe brightness temperatures observed in the MIZ.

  6. Design of active feedback for rehabilitation device

    Directory of Open Access Journals (Sweden)

    Liska Ondrej

    2016-01-01

    Full Text Available Sensor systems are an essential part of automated equipment. They are even more important in machines that come in contact with people, because they have a significant impact on safety. This paper describes the design of active feedback for rehabilitation device driven by pneumatic artificial muscles. Here are presented three methods for measuring the load of the robot. The first is a system composed of Force Sensitive Resistors (FSR placed in the handle of the device. Two other methods are intended to measure the load of the actuator composed of artificial muscles. The principle of one method is to measure the difference in filling pressures of the muscles, second is based on strain measurement in the drive cables. The paper describes advantages and disadvantages of using each of these methods in a rehabilitation device

  7. Microwave-assisted green synthesis and antimicrobial activity of ...

    African Journals Online (AJOL)

    Available online at http://www.tjpr.org ... Methods: The synthesis of AgNPs of a P. niruri extract was carried out in a microwave oven. The extraction .... Characterization of silver nanoparticles ... and current were 36 kV and 20 mA, respectively.

  8. Internally gas-cooled radiofrequency applicators as an alternative to conventional radiofrequency and microwave ablation devices: An in vivo comparison

    Energy Technology Data Exchange (ETDEWEB)

    Rempp, Hansjörg, E-mail: Hansjoerg.rempp@med.uni-tuebingen.de [Eberhard Karls University of Tübingen, Tübingen University Hospital, Department of Diagnostic and Interventional Radiology, Hoppe-Seyler-Straße 3, Tübingen, 72076 (Germany); Voigtländer, Matthias [ERBE Elektromedizin GmbH, Waldhörnlestraße 17, 72072 Tübingen (Germany); Schenk, Martin [Eberhard Karls University of Tuebingen, Tübingen University Hospital, Department of General, Visceral and Transplant Surgery, Hoppe-Seyler-Straße 3, 72076 Tübingen (Germany); Enderle, Markus D. [ERBE Elektromedizin GmbH, Waldhörnlestraße 17, 72072 Tübingen (Germany); Scharpf, Marcus [Eberhard Karls University of Tuebingen, Insitute of Pathology, Department on General Pathology and Pathological Anatomy, Liebermeisterstraße 8, 72076 Tübingen (Germany); Greiner, Tim O. [Eberhard Karls University of Tuebingen, Tübingen University Hospital, Department of General, Visceral and Transplant Surgery, Hoppe-Seyler-Straße 3, 72076 Tübingen (Germany); Neugebauer, Alexander [ERBE Elektromedizin GmbH, Waldhörnlestraße 17, 72072 Tübingen (Germany); and others

    2013-08-15

    Purpose: To test the efficacy of internally CO{sub 2}-cooled radiofrequency (RF) ablation in vivo and to compare its effectiveness to a standard water-cooled RF probe and to a gas-cooled microwave (MW) device. Method and materials: 49 ablations were performed on 15 pigs under general anesthesia using 15G monopolar CO{sub 2}-cooled RF applicators, 17G monopolar water-cooled RF applicators and 15G internally CO{sub 2}-cooled microwave devices. The power of the MW device was 45 W, the current of the gas-cooled RF device was 1200–1600 mA. At the water-cooled RF probe, maximum power of 200 W was set. Ablation time was 15 min. The short and long axes of the ablation zone were measured. Histological analyses and NADH-staining were performed. The diameters and the ablation volumes were compared using an analysis of variance. Results: No spots of untreated tissue were observed close to the cooled needle track in any of the ablation zones. The largest short axis diameter was 3.4 ± 0.5 cm achieved with the gas-cooled monopolar applicator. With the water-cooled applicators, short axis diameter was significantly smaller, reaching 2.5 ± 0.4 cm. Gas-cooled MW probes achieved 2.9 ± 1.0 cm. The largest ablation volume was 31.5 ± 12 ml (gas-cooled RF), and the smallest was 12.7 ± 4 ml (water-cooled RF). Short/long axis ratio was largest for gas-cooled RF probes with 0.73 ± 0.08 versus 0.64 ± 0.04 for the water-cooled probes and 0.49 ± 0.25 for the microwave applicator. Conclusion: Gas-cooled RF applicators may have a higher potential for effective destruction of liver lesions than comparable water-cooled RF systems, and may be an alternative to standard RF and MW ablation devices.

  9. Device-Free Indoor Activity Recognition System

    Directory of Open Access Journals (Sweden)

    Mohammed Abdulaziz Aide Al-qaness

    2016-11-01

    Full Text Available In this paper, we explore the properties of the Channel State Information (CSI of WiFi signals and present a device-free indoor activity recognition system. Our proposed system uses only one ubiquitous router access point and a laptop as a detection point, while the user is free and neither needs to wear sensors nor carry devices. The proposed system recognizes six daily activities, such as walk, crawl, fall, stand, sit, and lie. We have built the prototype with an effective feature extraction method and a fast classification algorithm. The proposed system has been evaluated in a real and complex environment in both line-of-sight (LOS and none-line-of-sight (NLOS scenarios, and the results validate the performance of the proposed system.

  10. New Approach for Monitoring Seismic and Volcanic Activities Using Microwave Radiometer Data

    Science.gov (United States)

    Maeda, Takashi; Takano, Tadashi

    Interferograms formed from the data of satellite-borne synthetic aperture radar (SAR) enable us to detect slight land-surface deformations related to volcanic eruptions and earthquakes. Currently, however, we cannot determine when land-surface deformations occurred with high time resolution since the time lag between two scenes of SAR used to form interferograms is longer than the recurrent period of the satellite carrying it (several tens of days). In order to solve this problem, we are investigating new approach to monitor seismic and vol-canic activities with higher time resolution from satellite-borne sensor data, and now focusing on a satellite-borne microwave radiometer. It is less subject to clouds and rainfalls over the ground than an infrared spectrometer, so more suitable to observe an emission from land sur-faces. With this advantage, we can expect that thermal microwave energy by increasing land surface temperatures is detected before a volcanic eruption. Additionally, laboratory experi-ments recently confirmed that rocks emit microwave energy when fractured. This microwave energy may result from micro discharges in the destruction of materials, or fragment motions with charged surfaces of materials. We first extrapolated the microwave signal power gener-ated by rock failures in an earthquake from the experimental results and concluded that the microwave signals generated by rock failures near the land surface are strong enough to be detected by a satellite-borne radiometer. Accordingly, microwave energy generated by rock failures associated with a seismic activity is likely to be detected as well. However, a satellite-borne microwave radiometer has a serious problem that its spatial res-olution is too coarse compared to SAR or an infrared spectrometer. In order to raise the possibility of detection, a new methodology to compensate the coarse spatial resolution is es-sential. Therefore, we investigated and developed an analysis method to detect local

  11. Microwave-assisted activation for electroless nickel plating on PMMA microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yen-Chung [Graduate School of Defense Science, Chung Cheng Institute of Technology, National Defense University, Tao-Yuan, Taiwan 335 (China); Materials and Electro-optics Research Division, Chung Shan Institute of Science and Technology, Tao-Yuan, Taiwan 325 (China); Liu, Robert Lian-Huey [Graduate School of Defense Science, Chung Cheng Institute of Technology, National Defense University, Tao-Yuan, Taiwan 335 (China); Department of Chemical and Materials Engineering, Minghsin University of Science and Technology, Hsinchu Taiwan 304 (China); Chen, Xin-Liang [Graduate School of Defense Science, Chung Cheng Institute of Technology, National Defense University, Tao-Yuan, Taiwan 335 (China); Shu, Hsiou-Jeng [Materials and Electro-optics Research Division, Chung Shan Institute of Science and Technology, Tao-Yuan, Taiwan 325 (China); Ger, Ming-Der, E-mail: mingderger@gmail.com [Department of Chemical and Materials Engineering, Chung Cheng Institute of Technology, National Defense University, Tao-Yuan, Taiwan 335 (China)

    2011-05-15

    A novel microwave-assisted activation method for electroless plating on PMMA microspheres is presented in this study. When the microwave irradiation was applied during the activation step, the amount of the Pd species adsorbed on PMMA surfaces was much higher than that of sample pretreated with a conventional activation process without microwave irradiation. With this activation method, it was also shown that the adsorbed Pd species with a size of 4-6 nm were uniformly distributed on the surfaces of the PMMA microspheres, thus a smooth and uniform nickel-phosphorus coating on the PMMA microspheres was obtained by subsequent electroless plating. The samples after each step were characterized by XPS, TEM, ICP and SEM.

  12. Monitoring Human Activity through Portable Devices

    Directory of Open Access Journals (Sweden)

    G. Sebestyen

    2012-06-01

    Full Text Available Monitoring human activity may be useful for medical supervision and for prophylactic purposes. Mobile devices like intelligent phones or watches have multiple sensors and wireless communication capabilities which can be used for this purpose. This paper presents some integrated solutions for determining and continuous monitoring of a person’s state. Aspects taken into consideration are: activity detection and recognition based on acceleration sensors, wireless communication protocols for data acquisition, web monitoring, alerts generation and statistical processing of multiple sensorial data. As practical implementations two case studies are presented, one using an intelligent phone and another using a mixed signal processor integrated in a watch.

  13. Active noise cancellation in hearing devices

    DEFF Research Database (Denmark)

    2013-01-01

    Disclosed is a hearing device system comprising at least one hearing aid circuitry and at least one active noise cancellation unit, the at least one hearing aid circuitry comprises at least one input transducer adapted to convert a first audio signal to an electric audio signal; a signal processor...... connected to the at least one input transducer and adapted to process said electric audio signal by at least partially correcting for a hearing loss of a user; an output transducer adapted to generate from at least said processed electric audio signal a sound pressure in an ear canal of the user, whereby...... the generated sound pressure is at least partially corrected for the hearing loss of the user; ; the at least one active noise cancellation unit being adapted to provide an active noise cancellation signal adapted to perform active noise cancellation of an acoustical signal entering the ear canal in addition...

  14. Combined effect of microwave and activated carbon on the remediation of polychlorinated biphenyl-contaminated soil.

    Science.gov (United States)

    Liu, Xitao; Yu, Gang

    2006-04-01

    The application of microwave and activated carbon for the treatment of polychlorinated biphenyl (PCB) contaminated soil was explored in this study with a model compound of 2,4,5-trichlorobiphenyl (PCB29). PCB-contaminated soil was treated in a quartz reactor by microwave irradiation at 2450MHz with the addition of granular activated carbon (GAC). In this procedure, GAC acted as microwave absorbent for reaching high temperature and reductant for dechlorination. A sheltered type-K thermocouple was applied to record the temperature rising courses. It was shown that the addition of GAC could effectively promote the temperature rising courses. The determination of PCB residues in soil by gas chromatography (GC) revealed that rates of PCB removal were highly dependent on microwave power, soil moisture content, and the amount of GAC added. GC with mass spectrum (MS) detector and ion chromatography were employed for the analysis of degradation intermediates and chlorine ions, respectively. It was suggested that microwave irradiation with the assistance of activated carbon might be a potential technology for the remediation of PCB-contaminated soil.

  15. Selective interference with pacemaker activity by electrical dental devices.

    Science.gov (United States)

    Miller, C S; Leonelli, F M; Latham, E

    1998-01-01

    We sought to determine whether electromagnetic interference with cardiac pacemakers occurs during the operation of contemporary electrical dental equipment. Fourteen electrical dental devices were tested in vitro for their ability to interfere with the function of two Medtronics cardiac pacemakers (one a dual-chamber, bipolar Thera 7942 pacemaker, the other a single-chamber, unipolar Minix 8340 pacemaker). Atrial and ventricular pacemaker output and electrocardiographic activity were monitored by means of telemetry with the use of a Medtronics 9760/90 programmer. Atrial and ventricular pacing were inhibited by electromagnetic interference produced by the electrosurgical unit up to a distance of 10 cm, by the ultrasonic bath cleaner up to 30 cm, and by the magnetorestrictive ultrasonic scalers up to 37.5 cm. In contrast, operation of the amalgamator, electric pulp tester, composite curing light, dental handpieces, electric toothbrush, microwave oven, dental chair and light, ENAC ultrasonic instrument, radiography unit, and sonic scaler did not alter pacing rate or rhythm. These results suggest that certain electrosurgical and ultrasonic instruments may produce deleterious effects in medically fragile patients with cardiac pacemakers.

  16. Investigation on the rapid degradation of congo red catalyzed by activated carbon powder under microwave irradiation

    International Nuclear Information System (INIS)

    Zhang Zhaohong; Shan Yabo; Wang Jun; Ling Hongjie; Zang Shuliang; Gao Wei; Zhao Zhe; Zhang Huachun

    2007-01-01

    Azo dyestuff-congo red in aqueous solution can be degraded rapidly under microwave irradiation in the presence of activated carbon powder. The results showed that the degradation ratio could reach 87.79% for 25 mL total volume with 50 mg/L congo red and 2.0 g/L activated carbon powder under 1.5 min microwave irradiation. Furthermore, within the same irradiation time, congo red could be degraded fully by increasing addition amount (e.g. 3.6 g/L) of activated carbon powder and the degradation ratio was up to 96.49%. Otherwise, with the same addition amount, congo red also could be degraded completely by prolonging irradiation time (e.g. 2.5 min) and the degradation ratio was up to 97.88%. In addition, the influences of microwave irradiation time, initial concentration of congo red, addition amount and used times of activated carbon powder as well as solution acidity on the degradation were discussed in details adopting UV-vis spectra, FT-IR spectra, ion chromatography, high phase liquid chromatography (HPLC) and TOC analysis technologies. Here, the method using activated carbon powder as catalyst under microwave irradiation shows many advantages including high degradation ratios, short reaction time, low costs, no intermediates and no secondary pollution. Therefore, it may be fit for dealing with various azo dyestuff wastewaters on a large scale

  17. Physical properties of activated carbon from fibers of oil palm empty fruit bunches by microwave assisted potassium hydroxide activation

    Science.gov (United States)

    Farma, Rakhmawati; Fatjrin, Delika; Awitdrus, Deraman, Mohamad

    2017-01-01

    The activated carbon adsorption was influenced by the quality of activated carbon. The activated carbon quality can be improved by chemical activation and microwave irradiation. In this study, activated carbon has been made using biomass from fibers of oil palm empty fruit bunches. The microwave irradiation was applied at various irradiation times of 5, 10, 15 and 20 minutes, and at output power of 630 Watt. The physical properties of activated carbon were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray, and methylene blue adsorption. Analysis of microstructure showed that the activated carbon was semicrystalline with two peaks of 002 and 100 at 2θ around of 22° and 44°, respectively. The values of stack height (Lc) before and after irradiation increased from 2,799 nm to 3,860 nm, which indicated increasing surface area. Characteristics of surface morphology of activated carbon showed the pores number increased after microwave irradiation. Microwave irradiation time of 15 minutes resulted the highest pores number justified in the activated carbon with their surface area of 319,60 m2/g and adsorption of methylene blue of 86,07 mg/g.

  18. Continuous microwave pasteurization of a vegetable smoothie improves its physical quality and hinders detrimental enzyme activity.

    Science.gov (United States)

    Arjmandi, Mitra; Otón, Mariano; Artés, Francisco; Artés-Hernández, Francisco; Gómez, Perla A; Aguayo, Encarna

    2017-01-01

    The effect of a pasteurization treatment at 90 ± 2 ℃ for 35 s provided by continuous microwave under different doses (low power/long time and high power/short time) or conventional pasteurization on the quality of orange-colored smoothies and their changes throughout 45 days of storage at 5 ℃ was investigated. A better color retention of the microwave pasteurization- treated smoothie using high power/short time than in conventionally processed sample was evidenced by the stability of the hue angle. The continuous microwave heating increased the viscosity of the smoothie more than the conventional pasteurization in comparison with non-treated samples. Lower residual enzyme activities from peroxidase, pectin methylesterase and polygalacturonase were obtained under microwave heating, specifically due to the use of higher power/shorter time. For this kind of smoothie, polygalacturonase was the more thermo-resistant enzyme and could be used as an indicator of pasteurization efficiency. The use of a continuous semi-industrial microwave using higher power and shorter time, such as 1600 W/206 s and 3600 W/93 s, resulted in better quality smoothies and greater enzyme reduction than conventional thermal treatment. © The Author(s) 2016.

  19. Synergistic use of active and passive microwave in soil moisture estimation

    Science.gov (United States)

    O'Neill, P.; Chauhan, N.; Jackson, T.; Saatchi, S.

    1992-01-01

    Data gathered during the MACHYDRO experiment in central Pennsylvania in July 1990 have been utilized to study the synergistic use of active and passive microwave systems for estimating soil moisture. These data sets were obtained during an eleven-day period with NASA's Airborne Synthetic Aperture Radar (AIRSAR) and Push-Broom Microwave Radiometer (PBMR) over an instrumented watershed which included agricultural fields with a number of different crop covers. Simultaneous ground truth measurements were also made in order to characterize the state of vegetation and soil moisture under a variety of meteorological conditions. A combination algorithm is presented as applied to a representative corn field in the MACHYDRO watershed.

  20. Microwave amplifier and active circuit design using the real frequency technique

    CERN Document Server

    Jarry, Pierre

    2016-01-01

    This book focuses on the authors' Real Frequency Technique (RFT) and its application to a wide variety of multi-stage microwave amplifiers and active filters, and passive equalizers for radar pulse shaping and antenna return loss applications. The first two chapters review the fundamentals of microwave amplifier design and provide a description of the RFT. Each subsequent chapter introduces a new type of amplifier or circuit design, reviews its design problems, and explains how the RFT can be adapted to solve these problems. The authors take a practical approach by summarizing the design steps and giving numerous examples of amplifier realizations and measured responses. Provides a complete description of the RFT as it is first used to design multistage lumped amplifiers using a progressive optimization of the equalizers, leading to a small umber of parameters to optimize simultaneously Presents modifications to the RFT to design trans-impedance microwave amplifiers that are used for photodiodes acti...

  1. Challenges in application of Active Cold Loads for microwave radiometer calibration

    DEFF Research Database (Denmark)

    Søbjærg, Sten Schmidl; Balling, Jan E.; Skou, Niels

    2012-01-01

    Two Active Cold Loads (ACLs) for microwave radiometer calibration, operating at X-band, are evaluated with respect to important stability parameters. Using a stable radiometer system as test bed, absolute levels of 77 K and 55 K are found. This paper identifies and summarizes potential challenges...

  2. Microwave-assisted synthesis of bio-active heterocycles in aqueous media

    KAUST Repository

    Polshettiwar, Vivek

    2010-01-01

    Synthesis of bio-active heterocycles and fine chemicals in aqueous media are one of the best solutions for the development of green and sustainable protocols. To illustrate the advantages of aqueous MW chemistry in heterocycle synthesis, in this chapter, various synthetic pathways developed in recent years in aqueous reaction media using microwave irradiation are described.

  3. High Power Microwave Emission of Large and Small Orbit Gyrotron Devices in Rectangular Interaction Structures

    Science.gov (United States)

    Hochman, J. M.; Gilgenbach, R. M.; Jaynes, R. L.; Rintamaki, J. I.; Luginsland, J. W.; Lau, Y. Y.; Spencer, T. A.

    1996-11-01

    Experiments utilize large and small orbit e-beam gyrotron devices in a rectangular-cross-section (RCS) gyrotron. This device is being explored to examine polarization control. Other research issues include pulse shortening, and mode competition. MELBA generates electron beams with parameters of: -800kV, 1-10kA diode current, and 0.5-1.0 μ sec pulselengths. The small orbit gyrotron device is converted to a large orbit experiment by running MELBA's annular electron beam through a magnetic cusp. Initial experiments showed an increase in beam alpha (V_perp/V_par) of a factor of ~ 4 between small and large orbit devices. Experimental results from the RCS gyrotron will be compared for large-orbit and small-orbit electron beams. Beam transport data and frequency measurements will be presented. Computer modeling utilizing the MAGIC and E-gun codes will be shown.

  4. Microwave heating type evaporator

    International Nuclear Information System (INIS)

    Taura, Masazumi; Nishi, Akio; Morimoto, Takashi; Izumi, Jun; Tamura, Kazuo; Morooka, Akihiko.

    1987-01-01

    Purpose: To prevent evaporization stills against corrosion due to radioactive liquid wastes. Constitution: Microwaves are supplied from a microwave generator by way of a wave guide tube and through a microwave permeation window to the inside of an evaporatization still. A matching device is attached to the wave guide tube for transmitting the microwaves in order to match the impedance. When the microwaves are supplied to the inside of the evaporization still, radioactive liquid wastes supplied from a liquid feed port by way of a spray tower to the inside of the evaporization still is heated and evaporated by the induction heating of the microwaves. (Seki, T.)

  5. Main principles of passive devices based on graphene and carbon films in microwave-THz frequency range

    Science.gov (United States)

    Kuzhir, Polina P.; Paddubskaya, Alesia G.; Volynets, Nadezhda I.; Batrakov, Konstantin G.; Kaplas, Tommi; Lamberti, Patrizia; Kotsilkova, Rumiana; Lambin, Philippe

    2017-07-01

    The ability of thin conductive films, including graphene, pyrolytic carbon (PyC), graphitic PyC (GrPyC), graphene with graphitic islands (GrI), glassy carbon (GC), and sandwich structures made of all these materials separated by polymer slabs to absorb electromagnetic radiation in microwave-THz frequency range, is discussed. The main physical principles making a basis for high absorption ability of these heterostructures are explained both in the language of electromagnetic theory and using representation of equivalent electrical circuits. The idea of using carbonaceous thin films as the main working elements of passive radiofrequency (RF) devices, such as shields, filters, polarizers, collimators, is proposed theoretically and proved experimentally. The important advantage of PyC, GrI, GrPyC, and GC is that, in contrast to graphene, they either can be easily deposited onto a dielectric substrate or are strong enough to allow their transfer from the catalytic substrate without a shuttle polymer layer. This opens a new avenue toward the development of a scalable protocol for cost-efficient production of ultralight electromagnetic shields that can be transferred to commercial applications. A robust design via finite-element method and design of experiment for RF devices based on carbon/graphene films and sandwiches is also discussed in the context of virtual prototyping.

  6. Microwave-assisted extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs) used to indoor air monitoring

    International Nuclear Information System (INIS)

    Esteve-Turrillas, Francesc A.; Pastor, Agustin; Guardia, Miguel de la

    2006-01-01

    A rapid and environmentally friendly methodology was developed for the extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs), in which they were preconcentrated in gas phase. The method was based on gas chromatography mass-mass spectrometry determination after a microwave-assisted extraction, in front of the widely employed dialysis method. SPMDs were extracted twice with 30 mL hexane:acetone, irradiated with 250 W power output, until 90 deg. C in 10 min, this temperature being held for another 10 min. Clean-up of the extracts was performed by acetonitrile-hexane partitioning and solid-phase extraction (SPE) with a combined cartridge of 2 g basic-alumina, deactivated with 5% water, and 500 mg C 18 . Pyrethroids investigated were Allethrin, Prallethrin, Tetramethrin, Bifenthrin, Phenothrin, λ-Cyhalothrin, Permethrin, Cyfluthrin, Cypermethrin, Flucythrinate, Esfenvalerate, Fluvalinate and Deltamethrin. The main pyrethroid synergist compound, Pyperonyl Butoxide, was also studied. Limit of detection values ranging from 0.3 to 0.9 ng/SPMD and repeatability data, as relative standard deviation, from 2.9 to 9.4%, were achieved. Pyrethroid recoveries, for spiked SPMDs, with 100 ng of each one of the pyrethroids evaluated, were from 61 ± 8 to 103 ± 7% for microwave-assisted extraction, versus 54 ± 4 to 104 ± 3% for dialysis reference method. Substantial reduction of solvent consumed (from 400 to 60 mL) and analysis time (from 48 to 1 h) was achieved by using the developed procedure. High concentration levels of pyrethroid compounds, from 0.14 to 7.3 μg/SPMD, were found in indoor air after 2 h of a standard application

  7. Microwave-assisted extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs) used to indoor air monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Esteve-Turrillas, Francesc A. [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain); Pastor, Agustin [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain)]. E-mail: agustin.pastor@uv.es; Guardia, Miguel de la [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain)

    2006-02-23

    A rapid and environmentally friendly methodology was developed for the extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs), in which they were preconcentrated in gas phase. The method was based on gas chromatography mass-mass spectrometry determination after a microwave-assisted extraction, in front of the widely employed dialysis method. SPMDs were extracted twice with 30 mL hexane:acetone, irradiated with 250 W power output, until 90 deg. C in 10 min, this temperature being held for another 10 min. Clean-up of the extracts was performed by acetonitrile-hexane partitioning and solid-phase extraction (SPE) with a combined cartridge of 2 g basic-alumina, deactivated with 5% water, and 500 mg C{sub 18}. Pyrethroids investigated were Allethrin, Prallethrin, Tetramethrin, Bifenthrin, Phenothrin, {lambda}-Cyhalothrin, Permethrin, Cyfluthrin, Cypermethrin, Flucythrinate, Esfenvalerate, Fluvalinate and Deltamethrin. The main pyrethroid synergist compound, Pyperonyl Butoxide, was also studied. Limit of detection values ranging from 0.3 to 0.9 ng/SPMD and repeatability data, as relative standard deviation, from 2.9 to 9.4%, were achieved. Pyrethroid recoveries, for spiked SPMDs, with 100 ng of each one of the pyrethroids evaluated, were from 61 {+-} 8 to 103 {+-} 7% for microwave-assisted extraction, versus 54 {+-} 4 to 104 {+-} 3% for dialysis reference method. Substantial reduction of solvent consumed (from 400 to 60 mL) and analysis time (from 48 to 1 h) was achieved by using the developed procedure. High concentration levels of pyrethroid compounds, from 0.14 to 7.3 {mu}g/SPMD, were found in indoor air after 2 h of a standard application.

  8. Preparation of High Surface Area Activated Carbon from Spent Phenolic Resin by Microwave Heating and KOH Activation

    Science.gov (United States)

    Cheng, Song; Zhang, Libo; Zhang, Shengzhou; Xia, Hongying; Peng, Jinhui

    2018-01-01

    The spent phenolic resin is as raw material for preparing high surface area activated carbon (HSAAC) by microwave-assisted KOH activation. The effects of microwave power, activation duration and impregnation ratio (IR) on the iodine adsorption capability and yield of HSAAC were investigated. The surface characteristics of HSAAC were characterized by nitrogen adsorption isotherms, FTIR, SEM and TEM. The operating variables were optimized utilizing the response surface methodology (RSM) and were identified to be microwave power of 700 W, activation duration of 15 min and IR of 4, corresponding to a yield of 51.25 % and an iodine number of 2,384 mg/g. The pore structure parameters of the HSAAC, i. e., Brunauer-Emmett-Teller (BET) surface area, total pore volume, and average pore diameter were estimated to be 4,269 m2/g, 2.396 ml/g and 2.25 nm, respectively, under optimum conditions. The findings strongly support the feasibility of microwave-assisted KOH activation for preparation of HSAAC from spent phenolic resin.

  9. Feasibility study of microwave electron heating on the C-2 field-reversed configuration device

    International Nuclear Information System (INIS)

    Yang, Xiaokang; Ceccherini, Francesco; Dettrick, Sean; Binderbauer, Michl; Koehn, Alf; Petrov, Yuri

    2015-01-01

    Different microwave heating scenarios for the C-2 plasmas have been investigated recently with use of both the Genray ray-racing code and the IPF-FDMC full-wave code, and the study was focused on the excitation of the electron Bernstein wave (EBW) with O-mode launch. For a given antenna position on C-2 and the fixed 2D plasma density and equilibrium field profiles, simulations have been done for six selected frequencies (2.45 GHz, 5 GHz, 8 GHz, 18 GHz, 28 GHz, and 50 GHz). Launch angles have been optimized for each case in order to achieve high coupling efficiencies to the EBW by the O-X-B mode conversion process and high power deposition. Results show that among those six frequencies, the case of 8 GHz is the most promising scenario, which has both high mode conversion efficiency (90%) and the relatively deeper power deposition

  10. Thin film silicon by a microwave plasma deposition technique: Growth and devices, and, interface effects in amorphous silicon/crystalline silicon solar cells

    Science.gov (United States)

    Jagannathan, Basanth

    Thin film silicon (Si) was deposited by a microwave plasma CVD technique, employing double dilution of silane, for the growth of low hydrogen content Si films with a controllable microstructure on amorphous substrates at low temperatures (prepared by this technique. Such films showed a dark conductivity ˜10sp{-6} S/cm, with a conduction activation energy of 0.49 eV. Film growth and properties have been compared for deposition in Ar and He carrier systems and growth models have been proposed. Low temperature junction formation by undoped thin film silicon was examined through a thin film silicon/p-type crystalline silicon heterojunctions. The thin film silicon layers were deposited by rf glow discharge, dc magnetron sputtering and microwave plasma CVD. The hetero-interface was identified by current transport analysis and high frequency capacitance methods as the key parameter controlling the photovoltaic (PV) response. The effect of the interface on the device properties (PV, junction, and carrier transport) was examined with respect to modifications created by chemical treatment, type of plasma species, their energy and film microstructure interacting with the substrate. Thermally stimulated capacitance was used to determine the interfacial trap parameters. Plasma deposition of thin film silicon on chemically clean c-Si created electron trapping sites while hole traps were seen when a thin oxide was present at the interface. Under optimized conditions, a 10.6% efficient cell (11.5% with SiOsb2 A/R) with an open circuit voltage of 0.55 volts and a short circuit current density of 30 mA/cmsp2 was fabricated.

  11. High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

    National Research Council Canada - National Science Library

    Wilson, Clay

    2004-01-01

    .... civilian computer systems to the effects of EMP has been discussed in the media. EMP can be produced on a large scale using a single nuclear explosion, and on a smaller, non-nuclear scale using a device with batteries or chemical explosives...

  12. Effect of microwave heat-treatment time on the properties of activated carbons as electrode materials for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    He, X.; Wang, T.; Long, S.; Zhang, X.; Zheng, M. [Anhui Univ. of Technology, Ma' aushan (China). School of Chemistry and Chemical Engineering, Anhui Key Lab of Coal Clean Conversion and Utilization

    2010-07-01

    A microwave-assisted heating technique was used to prepare activated carbons (ACs) from petroleum coke with potassium hydroxide (KOH) as an activating agent. The aim of the study was to investigate the effect of heat treatment time on AC properties at 3, 5, and 7 minutes with a microwave power rate of 700 W. The structure and electrochemical performance of the microwave ACs were then compared with commercially prepared ACs. The study showed that the specific capacitance, equivalent series resistance and energy density of the AC electrodes decreased, while the cycle performance of the AC electrodes was improved. The specific capacitance and energy density of the ACs treated with microwave heat at 3 and 7 minutes was higher than rates observed in commercially-prepared ACs. Results showed that the microwave heat treatment method is an efficient means of obtaining stable ACs for use in supercapacitors. 3 refs., 1 tab., 1 fig.

  13. A novel solution for car traffic control based on radiometric microwave devices

    Science.gov (United States)

    Soldovieri, Francesco; Denisov, Alexander; Speziale, Victor

    2014-05-01

    The significant problem of traffic in big cities, connected with huge and building up quantity of automobile cars, demands for novel strategies, based on nonconventional solutions, in order to improve system traffic control, especially at crossroads. As well known, the usual solution is based on the time relay, which requires the installation of a fixed traffic interval (signal light switching) at a crossroad; this solution is low cost, but does not account for the actual traffic conditions. Therefore, in the recent years, attention is towards to new designs, where the monitoring of the and control of traffic is carried out by using various methods including, optical, the infrared, magnetic, radar tracking, acoustical ones. In this work, we discuss the deployment of high sensitivity radiometric systems and radiometers(sensor) in the microwave range [1, 2]. In fact, the radiometer as "sensor" can provide an always updated information about the car traffic in any weather condition and in absence or low visibility conditions. In fact, the radiometric sensor detects the cars thanks to the different behavior of the car roofs which reflect the cold sky whereas the road asphalt is visible as warm object (at around outside temperature). [1] A. G. Denisov, V. P. Gorishnyak, S. E. Kuzmin et al., "Some experiments concerning resolution of 32 sensors passive 8mm wave imaging system," in Proceedings of the International Symposium on Space Terahertz Technology (ISSTT '09), Charlottesville, Va, USA, April 2009. [2] F. Soldovieri, A. Natale, V. Gorishnyak, A. Pavluchenko, A. Denisov, and L. Chen, "Radiometric Imaging for Monitoring and Surveillance Issues," International Journal of Antennas and Propagation, vol. 2013, Article ID 272561, 8 pages, 2013. doi:10.1155/2013/272561.

  14. Synthesis of novel chalcone derivatives by conventional and microwave irradiation methods and their pharmacological activities

    Directory of Open Access Journals (Sweden)

    Mohammed Rayees Ahmad

    2016-09-01

    Full Text Available Chalcones are abundant in edible plants and are considered to be the precursors of flavonoids and isoflavonoids. Chalcones belong to an important class of flavonoids, which may be prepared by Claisen–Schmidt condensation. They possess a wide range of biological activities and industrial applications. The cytotoxicity against tumour cell lines may be the result of disruption of the cell cycle, inhibition of angiogenesis, interference with p53-MDM2 interaction, mitochondrial uncoupling or induction of apoptosis. Chalcones are synthesized by conventional and microwave assisted synthesis methods. By microwave assisted synthesis, a considerable increase in the reaction rate has been observed and that too, with better yields. The compounds have been screened for cytotoxic activity and antioxidant activity.

  15. Solar activity associated with an unusual series of microwave flux decreases

    International Nuclear Information System (INIS)

    Sawyer, C.

    1976-01-01

    East-limb passage of an activity complex in the spring of 1974 was accompanied by a remarkable series of microwave flux decreases. Within an interval of four days, two post-burst decreases and five 'absorption' events occurred, along with two oscillations. Hα patrol films and a spectrogram show a surge and flare sprays with an unusually large velocity of approach at the time of the first post-burst decrease. Two other 'absorption' events were loosely associated with prominence activations, but no outstanding Hα activity was seen at the time of the oscillations. These observations, along with published data, show that the flux decreases followed only flares that lay westward of the major microwave source; ejections from this location would likely have overlain the source while the region was near the east limb. Absorption by flare-ejected material is a plausible, though not exclusive, explanation of these events. (author)

  16. Influence of deflocculation on microwave disintegration and anaerobic biodegradability of waste activated sludge.

    Science.gov (United States)

    Ebenezer, A Vimala; Kaliappan, S; Adish Kumar, S; Yeom, Ick-Tae; Banu, J Rajesh

    2015-06-01

    In the present study, the potential benefits of deflocculation on microwave pretreatment of waste activated sludge were investigated. Deflocculation in the absence of cell lysis was achieved through the removal of extra polymeric substances (EPS) by sodium citrate (0.1g sodium citrate/g suspended solids), and DNA was used as a marker for monitoring cell lysis. Subsequent microwave pretreatment yielded a chemical oxygen demand (COD) solubilisation of 31% and 21%, suspended solids (SS) reduction of 37% and 22%, for deflocculated and flocculated sludge, respectively, with energy input of 14,000kJ/kg TS. When microwave pretreated sludge was subjected to anaerobic fermentation, greater accumulation of volatile fatty acid (860mg/L) was noticed in deflocculated sludge, indicating better hydrolysis. Among the samples subjected to BMP (Biochemical methane potential test), deflocculated microwave pretreated sludge showed better amenability towards anaerobic digestion with high methane production potential of 0.615L (gVS)(-1). Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Quality of Clotting Factor Activity in Fresh Frozen Plasma at Thaw with a Microwave System and after Storage at 4 degrees C for 48 Hours.

    Science.gov (United States)

    Kuta, Piotr; Hauck-Dlimi, Barbara; Strobel, Julian; Zimmermann, Robert; Eckstein, Reinhold

    2016-01-01

    Uncontrolled hemorrhage in polytrauma patients usually results in rapid need of blood products. Despite the shorter thawing times of microwave devices for heating fresh frozen plasma (FFP), their use has remained controversial, and just a few laboratory analyses have been published on this topic. The aim of this study was to analyse the quality of clotting factors immediately after thawing FFP with a microwave device and after 48-hour post thaw storage at 4 degrees C. 24 FFP units of all four ABO blood groups (six of each blood group) were thawed with a Transfusio-therm 2000 and later stored at 4 degrees C for 48 hours. Samples were drawn aseptically and investigated on various clotting factors and protein proteases (fibrinogen, antithrombin, FII, FV, FVII, FVIII, FIX, FX, FXI, FXIII, vWF antigen and activity, protein S, and protein C) using standard coagulation and chromogenic assays immediately after thawing and again after a 48-hour storage period at 4 degrees C. All units were tested for both anaerobic and aerobic microbial contamination using standard operating procedures immediately after thawing. After thawing, all coagulation factors and protein protease activities were within normal ranges. Blood group O individuals had approximately 25% lower plasma levels of vWF antigen and activity. After a 48-hour storage period at 4 degrees C, FVIII and FIX activities declined significantly in all blood groups, whereas the remaining clotting factors remained comparably stable. Immediately after rapid thawing using a microwave system, all FFP units contained adequate coagulation factor activities to maintain hemostatic activity at the time of product thaw. The post thaw refrigerated storage caused an anticipated decrease in factor VIII and IX activities, but retained normal coagulation factor levels of many plasma proteins. Therefore we conclude that the Transfusio-therm 2000 has no clinically significant influence on the activity of clotting factors and plasma

  18. Microwave Ablation and Immune Activation in the Treatment of Recurrent Colorectal Lung Metastases: A Case Report

    Directory of Open Access Journals (Sweden)

    Magnus Bäcklund

    2017-04-01

    Full Text Available We present a patient with colorectal metastases confined to the lungs and treated with multiple resections until this was not an option anymore, followed by stereotactic body radiation therapy until this option was drained. Then, the patient was successfully treated with multiple microwave ablations combined with immunological activation targeting the programmed cell death 1 receptor (PD-1, possibly instigating a powerful abscopal effect. Techniques, doses, and radiological findings are presented.

  19. Peroxide-assisted microwave activation of pyrolysis char for adsorption of dyes from wastewater.

    Science.gov (United States)

    Nair, Vaishakh; Vinu, R

    2016-09-01

    In this study, mesoporous activated biochar with high surface area and controlled pore size was prepared from char obtained as a by-product of pyrolysis of Prosopis juliflora biomass. The activation was carried out by a simple process that involved H2O2 treatment followed by microwave pyrolysis. H2O2 impregnation time and microwave power were optimized to obtain biochar with high specific surface area and high adsorption capacity for commercial dyes such as Remazol Brilliant Blue and Methylene Blue. Adsorption parameters such as initial pH of the dye solution and adsorbent dosage were also optimized. Pore size distribution, surface morphology and elemental composition of activated biochar were thoroughly characterized. H2O2 impregnation time of 24h and microwave power of 600W produced nanostructured biochar with narrow and deep pores of 357m(2)g(-1) specific surface area. Langmuir and Langmuir-Freundlich isotherms described the adsorption equilibrium, while pseudo second order model described the kinetics of adsorption. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Frequency multiplexed superconducting quantum interference device readout of large bolometer arrays for cosmic microwave background measurements.

    Science.gov (United States)

    Dobbs, M A; Lueker, M; Aird, K A; Bender, A N; Benson, B A; Bleem, L E; Carlstrom, J E; Chang, C L; Cho, H-M; Clarke, J; Crawford, T M; Crites, A T; Flanigan, D I; de Haan, T; George, E M; Halverson, N W; Holzapfel, W L; Hrubes, J D; Johnson, B R; Joseph, J; Keisler, R; Kennedy, J; Kermish, Z; Lanting, T M; Lee, A T; Leitch, E M; Luong-Van, D; McMahon, J J; Mehl, J; Meyer, S S; Montroy, T E; Padin, S; Plagge, T; Pryke, C; Richards, P L; Ruhl, J E; Schaffer, K K; Schwan, D; Shirokoff, E; Spieler, H G; Staniszewski, Z; Stark, A A; Vanderlinde, K; Vieira, J D; Vu, C; Westbrook, B; Williamson, R

    2012-07-01

    A technological milestone for experiments employing transition edge sensor bolometers operating at sub-Kelvin temperature is the deployment of detector arrays with 100s-1000s of bolometers. One key technology for such arrays is readout multiplexing: the ability to read out many sensors simultaneously on the same set of wires. This paper describes a frequency-domain multiplexed readout system which has been developed for and deployed on the APEX-SZ and South Pole Telescope millimeter wavelength receivers. In this system, the detector array is divided into modules of seven detectors, and each bolometer within the module is biased with a unique ∼MHz sinusoidal carrier such that the individual bolometer signals are well separated in frequency space. The currents from all bolometers in a module are summed together and pre-amplified with superconducting quantum interference devices operating at 4 K. Room temperature electronics demodulate the carriers to recover the bolometer signals, which are digitized separately and stored to disk. This readout system contributes little noise relative to the detectors themselves, is remarkably insensitive to unwanted microphonic excitations, and provides a technology pathway to multiplexing larger numbers of sensors.

  1. Optimization of microwave-assisted rubberwood sawdust based activated carbon preparation conditions for methylene blue removal

    Science.gov (United States)

    Khasri, Azduwin; Ahmad, Mohd Azmier

    2017-10-01

    Optimum preparation conditions of rubberwood sawdust based activated carbon (RSAC) for methylene blue (MB) dye removal was studied. RSAC was produced by applying physiochemical activation method by using potassium hydroxide as a chemical agent which accompanied by carbon dioxide gasification under microwave heating. The effects of microwave power, irradiation time and impregnation ratio on two types of responses namely MB removal and RSAC yield using the center composite design (CCD) were also included in this study. The preparation variables correlation for responses was developed by two quadratic models. Optimum preparation conditions of RSAC were obtained at microwave power, irradiation time and IR of 354 W, 4.5 minutes and 0.98, respectively, which resulted MB removal and yield of 83.79% and 28%, respectively. The average pore diameter, surface area and total pore volume of optimized RSAC were 4.12 nm, 796.33 m2/g and 0.4219 cm3/g, respectively. This sample was found to has well-developed pores on its surface and can be a promising adsorbent for MB removal from aqueous solution.

  2. Microwave assisted synthesis of some new coumarin-pyrazoline hybrids and their antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Ashok Dongamanti

    2015-01-01

    Full Text Available A series of pyrazolines 4a-g have been synthesized by Michael addition of chalcones 3a-g with hydrazine hydrate in presence of sodium acetate under conventional heating and microwave irradiation. Structures of the newly synthesized chalcones 3a-g and pyrazolines 4a-g have been established on the basis of IR, 1H & 13C NMR and mass spectral data. All the synthesized compounds were screened for their antimicrobial activity. Some of the compounds shown very good activity compared to standard drugs against all pathogenic bacteria and fungi.

  3. Manufacturing of Porous Al-Cr Preforms for Composite Reinforcing Using Microwave Activated Combustion Synthesis

    Directory of Open Access Journals (Sweden)

    Naplocha K.

    2014-10-01

    Full Text Available The combustion synthesis of porous skeletons (preforms of intermetallic Al–Cr compounds intended for metal matrix composite MMC reinforcing was developed. Mixture of Al and Cr powders with granularity of −10, −44, −74mm were cold isostatic pressed and next ignited and synthetized in a microwave reactor under argon atmosphere (microwave-activated combustion synthesis MACS. In order to ignite the synthesis, microwave energy was focused by a tuner on the specimen. The analysis of reaction temperature diagrams revealed that the synthesis proceeded through the following peritectic transformations: L(liquidus+Al7Cr→L+Al11Cr2→L+Al4Cr. Moreover, EDS and XRD examinations showed that the reaction proceeded between a solid Cr and a liquid Al to create a distinct envelope of Al9Cr4 on Cr particle which next extended and spreaded over the entire structure. The produced preforms with uniform structure and interconnected porosity were infiltrated with liquid Cu and Al alloy. The obtained composite materials exhibited high hardness, wear and distinct temperature oxidation resistance.

  4. Microwave synthesis and photocatalytic activities of ZnO bipods with different aspect ratios

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Fazhe; Zhao, Zengdian [Analysis and Testing Center, Shandong University of Technology, Zibo 255100 (China); Qiao, Xueliang, E-mail: xuelqiao@163.com [State Key Laboratory of Plastic Forming Simulation and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, Hubei (China); Tan, Fatang; Wang, Wei [State Key Laboratory of Plastic Forming Simulation and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, Hubei (China)

    2016-02-15

    Highlights: • We synthesized linked ZnO nanorods by a facile microwave method. • The effect of reaction parameters on ZnO was investigated. • ZnO bipods with different aspect ratios were prepared. • The photocatalytic performance of ZnO bipods was evaluated. - Abstract: Linked ZnO nanorods have been successfully prepared via a facile microwave method without any post-synthesis treatment. The X-ray diffraction (XRD) patterns indicated the precursor had completely transformed into the pure ZnO crystal. The images of field emitting scanning electron microscope (FESEM) and transmission electron microscope (TEM) showed that linked ZnO nanorods consisted predominantly of ZnO bipods. The formation process of the ZnO bipods was clearly discussed. ZnO bipods with different aspect ratios have been obtained by tuning the concentrations of reagents and microwave power. Moreover, the photocatalytic performance of ZnO bipods with different aspect ratios for degradation of methylene blue was systematically evaluated. The results of photocatalytic experiments showed that the photocatalytic activity increased with the aspect ratios of ZnO bipods increased. The reason is that ZnO bipods with larger aspect ratio have higher surface area, which can absorb more MB molecules to react with ·OH radicals.

  5. Device for measuring atmospheric radon activity

    International Nuclear Information System (INIS)

    Deml, F.; Jansky, Z.; Smejkal, Z.

    1989-01-01

    The device consists of a lightproof case pivoted on a stand. Minimally two chambers are provided in the case for holding glass scintillation chambers, each with an opening in its bottom. The centers of the openings lie on a common circle with its center in the center of rotation of the case. An opening for the passage of light is provided in the stand. The opening also is on the common circle of the centres of the openings. A photomultiplier is placed below the opening. Measurement always proceeds with one scintillation chamber only. Thus, replacement of scintillation chambers can take place simultaneously with measurement and rapid and continuous measurement can be secured. Case rotation can be controlled automatically. The device can be used not only in monitoring air pollution but also in monitoring solid materials, aquifers, mine corridors, natural materials, etc. (J.B.). 1 fig

  6. Effect of microwave irradiation on alfalfa seeds germination and nitrogenase activity of endophytic diazotrophs in seeds

    International Nuclear Information System (INIS)

    Zhang Shuqing; Li Jianfeng; Shi Shangli; Huo Pinghui; Zhu Xinqiang; Zhao Wenhan; Tao Rong

    2011-01-01

    Various microwave powers were used to irradiate alfalfa seeds with various time to study the effect of microwave irradiation on nitrogenase activity of endogenous azotobacter and germination of seeds. Germination rate, germination speed and nitrogenase activity of pure cultures that derived from seed-carried azotobacter were tested. The results indicate that : 800 W, 20 s and 500 W, 40 s are found with highest germination rate on the 1 st day, which is 122% and 88.9% times higher than the control group (P th day is 29.8% and 41.9% times longer than the control group, and more sensitive nitrogenase activity is found on condition of various time than various powers. Short time treatments on condition of the two irradiation powers can increase nitrogenase activity conspicuously, and the treatments that treated more than 32 s make nitrogenase activity lower than the control group, conspicuously. Nitrogenase activity is found 104.9% times higher than the control group on condition of 24 s. (authors)

  7. Microwave Synthesis, Characterization, and Antimicrobial Activity of Some Novel Isatin Derivatives

    Directory of Open Access Journals (Sweden)

    Ayman El-Faham

    2015-01-01

    Full Text Available Three series of isatin derivatives [3-hydrazino, 3-thiosemicarbazino, and 3-imino carboxylic acid derivatives] were synthesized employing microwave irradiation. The prepared compounds were characterized by FT-IR, NMR, elemental analysis, and X-ray crystallography for derivatives 5b. The synthesized compounds were screened for antimicrobial activity against selected bacteria and fungi. The results revealed that the N-alkyl isatin derivatives were biologically active with different spectrums activity. Most of the 3-hydrazino and 3-thiosemicarbazino isatin derivatives were biologically inactive and generally the active derivatives showed weak to moderate activity mainly against Gram-positive bacteria. The imino isatin carboxylic acid derivatives (2-[4-(1-benzyl-5-bromo-2-oxoindolin-3-ylideneamino phenyl]acetic acid, 5d showed promising activity against all tested Gram-positive bacteria and against fungal pathogens.

  8. Cognitive Inference Device for Activity Supervision in the Elderly

    Directory of Open Access Journals (Sweden)

    Nilamadhab Mishra

    2014-01-01

    Full Text Available Human activity, life span, and quality of life are enhanced by innovations in science and technology. Aging individual needs to take advantage of these developments to lead a self-regulated life. However, maintaining a self-regulated life at old age involves a high degree of risk, and the elderly often fail at this goal. Thus, the objective of our study is to investigate the feasibility of implementing a cognitive inference device (CI-device for effective activity supervision in the elderly. To frame the CI-device, we propose a device design framework along with an inference algorithm and implement the designs through an artificial neural model with different configurations, mapping the CI-device’s functions to minimise the device’s prediction error. An analysis and discussion are then provided to validate the feasibility of CI-device implementation for activity supervision in the elderly.

  9. Open active cloaking and illusion devices for the Laplace equation

    International Nuclear Information System (INIS)

    Ma, Qian; Yang, Fan; Jin, Tian Yu; Mei, Zhong Lei; Cui, Tie Jun

    2016-01-01

    We propose open active cloaking and illusion devices for the Laplace equation. Compared with the closed configurations of active cloaking and illusion devices, we focus on improving the distribution schemes for the controlled sources, which do not have to surround the protected object strictly. Instead, the controlled sources can be placed in several small discrete clusters, and produce the desired voltages along the controlled boundary, to actively hide or disguise the protected object. Numerical simulations are performed with satisfactory results, which are further validated by experimental measurements. The open cloaking and illusion devices have many advantages over the closed configurations in various potential applications. (paper)

  10. Microwave and RF engineering

    CERN Document Server

    Sorrentino, Roberto

    2010-01-01

    An essential text for both students and professionals, combining detailed theory with clear practical guidance This outstanding book explores a large spectrum of topics within microwave and radio frequency (RF) engineering, encompassing electromagnetic theory, microwave circuits and components. It provides thorough descriptions of the most common microwave test instruments and advises on semiconductor device modelling. With examples taken from the authors' own experience, this book also covers:network and signal theory;electronic technology with guided electromagnetic pr

  11. Optimization of enzymes-microwave-ultrasound assisted extraction of Lentinus edodes polysaccharides and determination of its antioxidant activity.

    Science.gov (United States)

    Yin, Chaomin; Fan, Xiuzhi; Fan, Zhe; Shi, Defang; Gao, Hong

    2018-05-01

    Enzymes-microwave-ultrasound assisted extraction (EMUE) method had been used to extract Lentinus edodes polysaccharides (LEPs). The enzymatic temperature, enzymatic pH, microwave power and microwave time were optimized by response surface methodology. The yields, properties and antioxidant activities of LEPs from EMUE and other extraction methods including hot-water extraction, enzymes-assisted extraction, microwave-assisted extraction and ultrasound-assisted extraction were evaluated. The results showed that the highest LEPs yield of 9.38% was achieved with enzymatic temperature of 48°C, enzymatic pH of 5.0, microwave power of 440W and microwave time of 10min, which correlated well with the predicted value of 9.79%. Additionally, LEPs from different extraction methods possessed typical absorption peak of polysaccharides, which meant different extraction methods had no significant effects on type of glycosidic bonds and sugar ring of LEPs. However, SEM images of LEPs from different extraction methods were significantly different. Moreover, the different LEPs all showed antioxidant activities, but LEPs from EMUE showed the highest reducing power when compared to other LEPs. The results indicated LEPs from EMUE can be used as natural antioxidant component in the pharmaceutical and functional food industries. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Microwave assisted synthesis of some new coumarin-pyrazoline hybrids and their antimicrobial activity

    OpenAIRE

    Ashok Dongamanti; Lakshmi Bommidi Vijaya; Ravi Sidda; Ganesh Arram

    2015-01-01

    A series of pyrazolines 4a-g have been synthesized by Michael addition of chalcones 3a-g with hydrazine hydrate in presence of sodium acetate under conventional heating and microwave irradiation. Structures of the newly synthesized chalcones 3a-g and pyrazolines 4a-g have been established on the basis of IR, 1H & 13C NMR and mass spectral data. All the synthesized compounds were screened for their antimicrobial activity. Some of the compounds shown very goo...

  13. Investigation of the use of microwave image line integrated circuits for use in radiometers and other microwave devices in X-band and above

    Science.gov (United States)

    Knox, R. M.; Toulios, P. P.; Onoda, G. Y.

    1972-01-01

    Program results are described in which the use of a/high permittivity rectangular dielectric image waveguide has been investigated for use in microwave and millimeter wavelength circuits. Launchers from rectangular metal waveguide to image waveguide are described. Theoretical and experimental evaluations of the radiation from curved image waveguides are given. Measurements of attenuation due to conductor and dielectric losses, adhesives, and gaps between the dielectric waveguide and the image plane are included. Various passive components are described and evaluations given. Investigations of various techniques for fabrication of image waveguide circuits using ceramic waveguides are also presented. Program results support the evaluation of the image line approach as an advantageous method for realizing low loss integrated electronic circuits for X-band and above.

  14. Experimental and Numerical Studies of Particle Acceleration by an Active Microwave Medium

    CERN Document Server

    Schoessow, Paul

    2005-01-01

    There has been considerable theoretical work on the so-called PASER concept, in which a particle beam is accelerated directly by absorbing energy from an active medium, analogous to the amplification of an optical signal in a laser. Use of an active microwave (maser) medium would have the advantage of requiring relaxed beam quality (mm vs. nm characteristic beam dimensions). Recent work using electron paramagnetic resonance (EPR) techniques has demonstrated activity in the microwave regime (i.e. negative imaginary part of the magnetic susceptibility) for a class of organic compounds. A solution of fullerene (C60) in a liquid crystal solvent has been reported in the literature to possess a maser transition in the X-band region. An external DC magnetic field is required to obtain the effect; the frequency of the maser transition is adjustable by varying the magnetic field strength. We will report on the development of numerical and laboratory tools to evaluate the use of this material for accelerator applicatio...

  15. Cognitive Inference Device for Activity Supervision in the Elderly

    OpenAIRE

    Mishra, Nilamadhab; Lin, Chung-Chih; Chang, Hsien-Tsung

    2014-01-01

    Human activity, life span, and quality of life are enhanced by innovations in science and technology. Aging individual needs to take advantage of these developments to lead a self-regulated life. However, maintaining a self-regulated life at old age involves a high degree of risk, and the elderly often fail at this goal. Thus, the objective of our study is to investigate the feasibility of implementing a cognitive inference device (CI-device) for effective activity supervision in the elderly....

  16. Microwave-activated Ni/carbon catalysts for highly selective hydrogenation of nitrobenzene to cyclohexylamine.

    Science.gov (United States)

    Lu, Xinhuan; He, Jie; Jing, Run; Tao, Peipei; Nie, Renfeng; Zhou, Dan; Xia, Qinghua

    2017-06-01

    Biocarbon supported Ni catalysts have been prepared by facile impregnation of Ni species by microwave-heating and used for selective hydrogenation of nitrobenzene to cyclohexylamine. These catalysts were characterized by X-ray diffraction, Raman spectra, N2 sorption measurement, X-ray photoelectron spectroscopy, temperature programmed reduction of H2 and H2 temperature-programmed desorption. The morphology and particle size of catalysts were imaged by scanning electron microscope and transmission electron microscope. For the hydrogenation of nitrobenzene to cyclohexylamine, 10%Ni/CSC-II(b) exhibits the best catalytic activity to achieve 100 mol% conversion of nitrobenzene and 96.7% selectivity of cyclohexylamine under reaction conditions of 2.0 MPa H2 and 200 °C, ascribed to high dispersion of Ni species and formation of nanosized Ni particles on the support aided by microwave-heating. Thus-prepared Ni/CSC catalyst is greatly activated, in which the addition of precious metal like Rh is totally avoided.

  17. Wireless Power Transfer to a Microaerial Vehicle with a Microwave Active Phased Array

    Directory of Open Access Journals (Sweden)

    Shotaro Nako

    2014-01-01

    Full Text Available A wireless power transfer system using a microwave active phased array was developed. In the system, power is transferred to a circling microaerial vehicle (MAV by a microwave beam of 5.8 GHz, which is formed and directed to the MAV using an active phased array antenna. The MAV is expected to support observation of areas that humans cannot reach. The power beam is formed by the phased array with eight antenna elements. Input power is about 5.6 W. The peak power density at 1,500 mm altitude was 2.63 mW/cm2. The power is sent to a circling MAV. Therefore, the transfer beam should be polarized circularly to achieve a constant power supply independent of its yaw angle. To minimize the polarization loss, a sequentially routed antenna (SRA was applied to the transmitter antenna. Results show that the axial ratio of 0.440 dB was accomplished and that power fluctuation was kept below 1%.

  18. Active Sensor for Microwave Tissue Imaging with Bias-Switched Arrays.

    Science.gov (United States)

    Foroutan, Farzad; Nikolova, Natalia K

    2018-05-06

    A prototype of a bias-switched active sensor was developed and measured to establish the achievable dynamic range in a new generation of active arrays for microwave tissue imaging. The sensor integrates a printed slot antenna, a low-noise amplifier (LNA) and an active mixer in a single unit, which is sufficiently small to enable inter-sensor separation distance as small as 12 mm. The sensor’s input covers the bandwidth from 3 GHz to 7.5 GHz. Its output intermediate frequency (IF) is 30 MHz. The sensor is controlled by a simple bias-switching circuit, which switches ON and OFF the bias of the LNA and the mixer simultaneously. It was demonstrated experimentally that the dynamic range of the sensor, as determined by its ON and OFF states, is 109 dB and 118 dB at resolution bandwidths of 1 kHz and 100 Hz, respectively.

  19. Hybrid Active-Passive Microwave Photonic Filter with High Quality Factor

    International Nuclear Information System (INIS)

    En-Ming, Xu; Xin-Liang, Zhang; Li-Na, Zhou; Yu, Zhang; De-Xiu, Huang

    2009-01-01

    A hybrid high quality factor (Q-factor) microwave photonic filter with a cascaded active filter and a passive filter is presented and experimentally demonstrated. The active infinite impulse response filter is realized by a recirculating delay line loop with a semiconductor optical amplifier, and a much narrower 3 dB bandwidth of response peaks can be achieved. A passive finite impulse response filter is realized by an unbalance Mach–Zehnder interferometer, and it is cascaded to select the desired filter frequencies and to suppress the intermediate peaks. Compared with the purely active filter scheme, the free spectrum range and the Q-factor of the hybrid structure can be doubled. Stable operation and a high Q-factor of 362 are experimentally demonstrated

  20. Multiobjective Optimization Method for Multichannel Microwave Components of Active Phased Array Antenna

    Directory of Open Access Journals (Sweden)

    Lu Wang

    2016-01-01

    Full Text Available Multichannel microwave components are widely used and the active phased array antenna is a typical representative. The high power generated from T/R modules in active phased array antenna (APAA leads to the degradation of its electrical performances, which seriously restricts the development of high-performance APAA. Therefore, to meet the demand of thermal design for APAA, a multiobjective optimization design model of cold plate is proposed. Furthermore, in order to achieve temperature uniformity and case temperature restrictions of APAA simultaneously, optimization model of channel structure is developed. Besides, an airborne active phased array antenna was tested as an example to verify the validity of the optimization model. The valuable results provide important reference for engineers to enhance thermal design technology of antennas.

  1. Optimized Fast-FISH with a-satellite probes: acceleration by microwave activation

    Directory of Open Access Journals (Sweden)

    Durm M.

    1997-01-01

    Full Text Available It has been shown for several DNA probes that the recently introduced Fast-FISH (fluorescence in situ hybridization technique is well suited for quantitative microscopy. For highly repetitive DNA probes the hybridization (renaturation time and the number of subsequent washing steps were reduced considerably by omitting denaturing chemical agents (e.g., formamide. The appropriate hybridization temperature and time allow a clear discrimination between major and minor binding sites by quantitative fluorescence microscopy. The well-defined physical conditions for hybridization permit automatization of the procedure, e.g., by a programmable thermal cycler. Here, we present optimized conditions for a commercially available X-specific a-satellite probe. Highly fluorescent major binding sites were obtained for 74oC hybridization temperature and 60 min hybridization time. They were clearly discriminated from some low fluorescent minor binding sites on metaphase chromosomes as well as in interphase cell nuclei. On average, a total of 3.43 ± 1.59 binding sites were measured in metaphase spreads, and 2.69 ± 1.00 in interphase nuclei. Microwave activation for denaturation and hybridization was tested to accelerate the procedure. The slides with the target material and the hybridization buffer were placed in a standard microwave oven. After denaturation for 20 s at 900 W, hybridization was performed for 4 min at 90 W. The suitability of a microwave oven for Fast-FISH was confirmed by the application to a chromosome 1-specific a-satellite probe. In this case, denaturation was performed at 630 W for 60 s and hybridization at 90 W for 5 min. In all cases, the results were analyzed quantitatively and compared to the results obtained by Fast-FISH. The major binding sites were clearly discriminated by their brightness

  2. Design of a microwave calorimeter for the microwave tokamak experiment

    International Nuclear Information System (INIS)

    Marinak, M.

    1988-01-01

    The initial design of a microwave calorimeter for the Microwave Tokamak Experiment is presented. The design is optimized to measure the refraction and absorption of millimeter rf microwaves as they traverse the toroidal plasma of the Alcator C tokamak. Techniques utilized can be adapted for use in measuring high intensity pulsed output from a microwave device in an environment of ultra high vacuum, intense fields of ionizing and non-ionizing radiation and intense magnetic fields. 16 refs

  3. Geometric investigation of a gaming active device

    Science.gov (United States)

    Menna, Fabio; Remondino, Fabio; Battisti, Roberto; Nocerino, Erica

    2011-07-01

    3D imaging systems are widely available and used for surveying, modeling and entertainment applications, but clear statements regarding their characteristics, performances and limitations are still missing. The VDI/VDE and the ASTME57 committees are trying to set some standards but the commercial market is not reacting properly. Since many new users are approaching these 3D recording methodologies, clear statements and information clarifying if a package or system satisfies certain requirements before investing are fundamental for those users who are not really familiar with these technologies. Recently small and portable consumer-grade active sensors came on the market, like TOF rangeimaging cameras or low-cost triangulation-based range sensor. A quite interesting active system was produced by PrimeSense and launched on the market thanks to the Microsoft Xbox project with the name of Kinect. The article reports the geometric investigation of the Kinect active sensors, considering its measurement performances, the accuracy of the retrieved range data and the possibility to use it for 3D modeling application.

  4. Advances in microwaves 3

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 3 covers the advances and applications of microwave signal transmission and Gunn devices. This volume contains six chapters and begins with descriptions of ground-station antennas for space communications. The succeeding chapters deal with beam waveguides, which offer interesting possibilities for transmitting microwave energy, as well as with parallel or tubular beams from antenna apertures. A chapter discusses the electron transfer mechanism and the velocity-field characteristics, with a particular emphasis on the microwave properties of Gunn oscillators. The l

  5. Second Law based definition of passivity/activity of devices

    Science.gov (United States)

    Sundqvist, Kyle M.; Ferry, David K.; Kish, Laszlo B.

    2017-10-01

    Recently, our efforts to clarify the old question, if a memristor is a passive or active device [1], triggered debates between engineers, who have had advanced definitions of passivity/activity of devices, and physicists with significantly different views about this seemingly simple question. This debate triggered our efforts to test the well-known engineering concepts about passivity/activity in a deeper way, challenging them by statistical physics. It is shown that the advanced engineering definition of passivity/activity of devices is self-contradictory when a thermodynamical system executing Johnson-Nyquist noise is present. A new, statistical physical, self-consistent definition based on the Second Law of Thermodynamics is introduced. It is also shown that, in a system with uniform temperature distribution, any rectifier circuitry that can rectify thermal noise must contain an active circuit element, according to both the engineering and statistical physical definitions.

  6. Low-temperature preparation and microwave photocatalytic activity study of TiO2-mounted activated carbon

    International Nuclear Information System (INIS)

    Liu Yazi; Yang Shaogui; Hong Jun; Sun Cheng

    2007-01-01

    TiO 2 thin films were deposited on granular activated carbon by a dip-coating method at low temperature (373 K), using microwave radiation to enhance the crystallization of titania nanoparticles. Uniform and continuous anatase titania films were deposited on the surface of activated carbon. BET surface area of TiO 2 -mounted activated carbon (TiO 2 /AC) decreased a little in comparison with activated carbon. TiO 2 /AC possessed strong optical absorption capacity with a band gap absorption edge around 360 nm. The photocatalytic activity did not increase when the as-synthesized TiO 2 /AC was thermally treated, but was much higher than commercial P-25 in degradation of phenol by irradiation of electrodeless discharge lamps (EDLs)

  7. Degradation of Active Brilliant Red X-3B by a microwave discharge electrodeless lamp in the presence of activated carbon.

    Science.gov (United States)

    Fu, Jie; Wen, Teng; Wang, Qing; Zhang, Xue-Wei; Zeng, Qing-Fu; An, Shu-Qing; Zhu, Hai-Liang

    2010-06-01

    Degradation of Active Brilliant Red X-3B (X-3B) in aqueous solution by a microwave discharge electrodeless lamp (MDEL) in the presence of activated carbon was investigated. The preliminary results proved this method could effectively degrade X-3B in aqueous solution. The removal percentages of colour and chemical oxygen demand were up to approximately 99% and 66%, respectively, at the conditions of 0.8 g/L dye concentration, 20 g/L activated carbon, pH 7.0 and 8 min microwave irradiation time. The degradation basically belonged to first-order reaction kinetics and its rate constant was 0.42 min(-1). No aromatic organics were detected in the final treated solution, indicating that the mineralization was relatively complete. By studying the change in solution properties, it could be concluded that MDEL-assisted oxidation was the dominant reaction mechanism. In addition, the influence of operational parameters and reuse of activated carbon were also discussed.

  8. Microfabricated Microwave-Integrated Surface Ion Trap

    Science.gov (United States)

    Revelle, Melissa C.; Blain, Matthew G.; Haltli, Raymond A.; Hollowell, Andrew E.; Nordquist, Christopher D.; Maunz, Peter

    2017-04-01

    Quantum information processing holds the key to solving computational problems that are intractable with classical computers. Trapped ions are a physical realization of a quantum information system in which qubits are encoded in hyperfine energy states. Coupling the qubit states to ion motion, as needed for two-qubit gates, is typically accomplished using Raman laser beams. Alternatively, this coupling can be achieved with strong microwave gradient fields. While microwave radiation is easier to control than a laser, it is challenging to precisely engineer the radiated microwave field. Taking advantage of Sandia's microfabrication techniques, we created a surface ion trap with integrated microwave electrodes with sub-wavelength dimensions. This multi-layered device permits co-location of the microwave antennae and the ion trap electrodes to create localized microwave gradient fields and necessary trapping fields. Here, we characterize the trap design and present simulated microwave performance with progress towards experimental results. This research was funded, in part, by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA).

  9. Plasma relativistic microwave electronics

    International Nuclear Information System (INIS)

    Kuzelev, M.V.; Loza, O.T.; Rukhadze, A.A.; Strelkov, P.S.; Shkvarunets, A.G.

    2001-01-01

    One formulated the principles of plasma relativistic microwave electronics based on the induced Cherenkov radiation of electromagnetic waves at interaction of a relativistic electron beam with plasma. One developed the theory of plasma relativistic generators and accelerators of microwave radiation, designed and studied the prototypes of such devices. One studied theoretically the mechanisms of radiation, calculated the efficiencies and the frequency spectra of plasma relativistic microwave generators and accelerators. The theory findings are proved by the experiment: intensity of the designed sources of microwave radiation is equal to 500 μW, the frequency of microwave radiation is increased by 7 times (from 4 up to 28 GHz), the width of radiation frequency band may vary from several up to 100%. The designed sources of microwave radiation are no else compared in the electronics [ru

  10. Entomocidal activity of microwave energy & some aqueous plant extracts against Tribolium castaneum Herbst & Trogoderma granarium Everts

    Science.gov (United States)

    Agha, W. N. A.; Amin, A. H.; Khidr, S. K.; Ismail, A. Y.

    2017-09-01

    A laboratory experiment was conducted in order to evaluate the efficacy of microwave radiation and aqueous plant extracts against red flour beetle Tribolium castaneum & khapra beetle Trogoderma granarium. The larvae stage with dried fruits (black raisin, red raisin, fig and apricot) were subjected to microwave radiation at different power levels (280,560 and 840) watt for three exposure times (10, 30 and 50) seconds. Mortalities increased with an increase of concentration or exposure time or both. Thus, highest mortality 90% was achieved at 840 watt power output and exposure time 50 second for both aforementioned species. Likewise, eucalyptus Eucalyptus camaldulensis, mint Mentha canadensis and myrtle Myrtus communis were studied for their toxicity effect on mortality of larval stage at three dosages (12500, 25000 and 50000) ppm for different exposure times (1, 2, 3 and 7) days. The larvae of khapra beetle were more resistant to the insecticidal activity of plant extracts in comparison with red flour beetle larvae. The LC50 values were varied in accordance to plant extracts types and concentrations within the four interval times of exposure. The LC50 values for both khapra & red flour beetles were (47234.07 & 5760.90) ppm respectively on black raisin after 7 days exposure to eucalyptus aqueous extract.

  11. Biopolymers Regulate Silver Nanoparticle under Microwave Irradiation for Effective Antibacterial and Antibiofilm Activities.

    Directory of Open Access Journals (Sweden)

    Palaniyandi Velusamy

    Full Text Available In the current study, facile synthesis of carboxymethyl cellulose (CMC and sodium alginate capped silver nanoparticles (AgNPs was examined using microwave radiation and aniline as a reducing agent. The biopolymer matrix embedded nanoparticles were synthesized under various experimental conditions using different concentrations of biopolymer (0.5, 1, 1.5, 2%, volumes of reducing agent (50, 100, 150 μL, and duration of heat treatment (30 s to 240 s. The synthesized nanoparticles were analyzed by scanning electron microscopy, UV-Vis spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy for identification of AgNPs synthesis, crystal nature, shape, size, and type of capping action. In addition, the significant antibacterial efficacy and antibiofilm activity of biopolymer capped AgNPs were demonstrated against different bacterial strains, Staphylococcus aureus MTCC 740 and Escherichia coli MTCC 9492. These results confirmed the potential for production of biopolymer capped AgNPs grown under microwave irradiation, which can be used for industrial and biomedical applications.

  12. Fe-, Co-, and Ni-Loaded Porous Activated Carbon Balls as Lightweight Microwave Absorbents.

    Science.gov (United States)

    Li, Guomin; Wang, Liancheng; Li, Wanxi; Xu, Yao

    2015-11-16

    Porous activated carbon ball (PACB) composites impregnated with iron, cobalt, nickel and/or their oxides were synthesized through a wet chemistry method involving PACBs as the carrier to load Fe(3+), Co(2+), and Ni(2+) ions and a subsequent carbothermal reduction at different annealing temperatures. The results show that the pyrolysis products of nitrates and/or the products from the carbothermal reduction are embedded in the pores of the PACBs, with different distributions, resulting in different crystalline phases. The as-prepared PACB composites possessed high specific surface areas of 791.2-901.5 m(2)  g(-1) and low densities of 1.1-1.3 g cm(-3). Minimum reflection loss (RL) values of -50.1, -20.6, and -20.4 dB were achieved for Fe-PACB (annealed at 500 °C), Co-PACB (annealed at 800 °C), and Ni-PACB (annealed at 800 °C) composites, respectively. Moreover, the influence of the amount of the magnetic components in the PACB composites on the microwave-absorbing performances was investigated, further confirming that the dielectric loss was the primary contributor to microwave absorption. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Classification of Active Microwave and Passive Optical Data Based on Bayesian Theory and Mrf

    Science.gov (United States)

    Yu, F.; Li, H. T.; Han, Y. S.; Gu, H. Y.

    2012-08-01

    A classifier based on Bayesian theory and Markov random field (MRF) is presented to classify the active microwave and passive optical remote sensing data, which have demonstrated their respective advantages in inversion of surface soil moisture content. In the method, the VV, VH polarization of ASAR and all the 7 TM bands are taken as the input of the classifier to get the class labels of each pixel of the images. And the model is validated for the necessities of integration of TM and ASAR, it shows that, the total precision of classification in this paper is 89.4%. Comparing with the classification with single TM, the accuracy increase 11.5%, illustrating that synthesis of active and passive optical remote sensing data is efficient and potential in classification.

  14. CLASSIFICATION OF ACTIVE MICROWAVE AND PASSIVE OPTICAL DATA BASED ON BAYESIAN THEORY AND MRF

    Directory of Open Access Journals (Sweden)

    F. Yu

    2012-08-01

    Full Text Available A classifier based on Bayesian theory and Markov random field (MRF is presented to classify the active microwave and passive optical remote sensing data, which have demonstrated their respective advantages in inversion of surface soil moisture content. In the method, the VV, VH polarization of ASAR and all the 7 TM bands are taken as the input of the classifier to get the class labels of each pixel of the images. And the model is validated for the necessities of integration of TM and ASAR, it shows that, the total precision of classification in this paper is 89.4%. Comparing with the classification with single TM, the accuracy increase 11.5%, illustrating that synthesis of active and passive optical remote sensing data is efficient and potential in classification.

  15. July 1974 solar events: a possible lower limit for microwave activity

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, P; Iacomo, P Jr; Koppe, E H; Marques dos Santos, P; Schaal, R E [Universidade Mackenzie, Sao Paulo (Brazil). Centro de Radio-Astronomia e Astrofisica; Blakey, J R [Surrey Univ., Guildford (UK). Dept. of Physics

    1975-11-01

    The active region McMath 10433 was the source of several flares and radio outbursts during the early part of July 1974. This region was tracked continuously, for several periods during the month at 22.2 GHz using a telescope with a 4 minutes of arc beam. Comparison with the results obtained simultaneously with a normal 7 GHz solar instrument indicate that there is important burst activity occurring at levels below the detection limit of normal solar patrol instruments. The time-development morphology of these bursts is similar to those normally observed and has enabled the simple events to be re-interpreted. A completely new type of event-the fast absorption-has also been recognized. The correlation of the microwave events with SPA events observed on VLF propagation is also discussed.

  16. Microwave assisted synthesis and anti-lipase activity of some new fluorine-containing benzimidazoles.

    Science.gov (United States)

    Menteşe, E; Yilmaz, F; Ülker, S; Kahveci, B

    2015-01-01

    In this study, a new series of fluorine containing benzimidazoles (4a-l) and bisbenzimidazoles (6a-c, 8) were synthesized by the reaction of o-phenylenediamines with iminoester hydrochlorides (3a-l, 7) in methanol under microwave irradiation. The structures of these newly synthesized compounds were identified by IR, (1)H-NMR, (13)C-NMR, mass spectroscopy and elemental analysis data. The synthesized compounds were screened for their pancreatic lipase activities. Our results indicate that the compounds 6a, 6b and 6c can serve as an anti-lipase agent. The compounds 6b and 6c inhibited pancreatic lipase activity by 84.03% and 97.49% at a concentration of 3 µg/mL, respectively. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Advances in microwaves

    CERN Document Server

    Young, Leo

    1967-01-01

    Advances in Microwaves, Volume 2 focuses on the developments in microwave solid-state devices and circuits. This volume contains six chapters that also describe the design and applications of diplexers and multiplexers. The first chapter deals with the parameters of the tunnel diode, oscillators, amplifiers and frequency converter, followed by a simple physical description and the basic operating principles of the solid state devices currently capable of generating coherent microwave power, including transistors, harmonic generators, and tunnel, avalanche transit time, and diodes. The next ch

  18. Pyrolysis of polystyrene waste in the presence of activated carbon in conventional and microwave heating using modified thermocouple.

    Science.gov (United States)

    Prathiba, R; Shruthi, M; Miranda, Lima Rose

    2018-06-01

    Pyrolysis process was experimented using two types of heating source, namely conventional and microwave. Polystyrene (PS) plastic waste was used as feedstock in a batch reactor for both the conventional (slow pyrolysis) and microwave pyrolysis. The effect of activated carbon to polystyrene ratio on (i) yield of oil, gas and residues (ii) reaction temperature (iii) reaction time were studied. Quality of oil from pyrolysis of polystyrene were assessed for the possible applicability in fuel production. Microwave power of 450 W and polymer to activated carbon ratio of 10:1, resulted in the highest oil yield of 93.04 wt.% with a higher heating value of 45 MJ kg -1 and a kinematic viscosity of 2.7 cSt. Microwave heating when compared to conventional heating method, exhibits a reaction temperature and time of 330 °C in 5.5 min, whereas in conventional heating system it was 418 °C in 60 min. The gas chromatography-mass spectrometry analysis of liquid oil from microwave pyrolysis predominantly yields alkenes of 8.44 wt.%, α-methyl styrene 0.96 wt.%, condensed ring aromatics 23.21 wt.% and benzene derivatives 26.77 wt.% when the polystyrene to activated carbon ratio was 10:1. Significant factor of using microwave heating is the amount of energy converted (kWh) is lesser than conventional heating. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Mathematical modeling of microwave dried celery leaves and determination of the effective moisture diffusivities and activation energy

    Directory of Open Access Journals (Sweden)

    Ilknur Alibas

    2014-06-01

    Full Text Available Celery (Apium graveolens L. var. secalinum Alef leaves with 50±0.07 g weight and 91.75±0.15% humidity (~11.21 db were dried using 8 different microwave power densities ranging between 1.8-20 W g-1, until the humidity fell down to 8.95±0.23% (~0.1 db. Microwave drying processes were completed between 5.5 and 77 min depending on the microwave power densities. In this study, measured values were compared with predicted values obtained from twenty thin layer drying theoretical, semi-empirical and empirical equations with a new thin layer drying equation. Within applied microwave power density; models whose coefficient and correlation (R² values are highest were chosen as the best models. Weibull distribution model gave the most suitable predictions at all power density. At increasing microwave power densities, the effective moisture diffusivity values ranged from 1.595 10-10 to 6.377 10-12 m2 s-1. The activation energy was calculated using an exponential expression based on Arrhenius equation. The linear relationship between the drying rate constant and effective moisture diffusivity gave the best fit.

  20. Absence of genotoxic activity from milk and water boiled in microwave oven in somatic cells from Drosophila melanogaster

    International Nuclear Information System (INIS)

    Dias, Cristina das Dores.

    2003-01-01

    This paper reports an experiment for evaluation of the possible genotoxic effects of food prepared in a microwave oven, through the mutation test and somatic recombination, in wings of Drosophila melanogaster. Two crossing have been performed: a standard cross-ST and a high bioactivation cross - HB resulting in marked trans -heterozygote descendents (MH) and balanced heterozygotes (BH). The 72 hours larvas were fed with water and milk boiled both in the microwave oven and in the traditional way. The MH individual wings were analyzed, where the spots can be induced either by mutation or mitotic recombination. The experiment presented negative results related to the genotoxic effects of the water and milk boiled using the microwave oven, in MH descendents of both crossing. Therefore, under these experimental conditions, genotoxic activity were not presented by milk and water boiled in the microwave oven. However, an extensive study using different techniques is necessary to investigate the action of the food prepared in the microwave oven on the genetic material

  1. Remediation of anionic dye from aqueous system using bio-adsorbent prepared by microwave activation.

    Science.gov (United States)

    Sharma, Arush; Sharma, Gaurav; Naushad, Mu; Ghfar, Ayman A; Pathania, Deepak

    2018-04-01

    The present study was attempted to ascertain the possible application of activated carbon as a cost-effective and eco-friendly adsorbent prepared via microwave-assisted chemical activation. The activated carbon was characterized using different techniques. The various adsorption parameters have been optimized to examine the viability of activated carbon as a plausible sorbent for the remediation of Congo red (CR) dye from the aquatic system. The equilibrium data adequately fitted to the Langmuir isotherm with better R 2 (0.994). The maximum adsorption capacity (q m ) of activated carbon was recorded to be 68.96 mg/g. Additionally, sorptional kinetic data were examined by reaction-based and diffusion-based models such as pseudo-first-order and pseudo-second-order equations, and Elovich, intra-particle diffusion, and Dumwald-Wagner models, respectively. The computed values of thermodynamic parameters such as free energy change (ΔG 0 ), enthalpy change (ΔH 0 ) and entropy change (ΔS 0 ) were recorded as -3.63, 42.47 and 152.07 J/mol K, respectively, at 30°C, which accounted for a favorable, spontaneous and endothermic process. The regeneration study emphasized that the percentage uptake declined from 90.35% to 83.45% after six cycles of testing. So, our findings implied that activated carbon produced from biomass must be cost-effectively used as an adsorbent for detoxifying the CR dye from industrial effluents.

  2. Mesh parameters influence on transparent and active antennas performance at microwaves

    Directory of Open Access Journals (Sweden)

    Alexis Martin

    2017-08-01

    Full Text Available Optically transparent and active square loop coplanar antennas operating in X-band are investigated in this letter. The frequency tunability is provided by a surface mounted beam-lead varactor with micrometric size, thereby no-visible to the naked eye. The influence of the metal mesh parameters on the sheet resistance (from 0.05 Ω/sq to 0.54 Ω/sq, the optical transparency (from 66% to 89% and the microwave performance (return loss, resonance frequency, radiation pattern and gain of such antennas is evaluated, compared with those of an opaque counterpart, and finally discussed. This study paves the way of their promising implementation on new surfaces, namely building and car windows for future wireless communications systems.

  3. Effect of Solvent, Catalyst Type and Catalyst Activation on the Microwave Transformation of 2-Tert-butylphenol

    Czech Academy of Sciences Publication Activity Database

    Radoiu, M.; Hájek, Milan

    2002-01-01

    Roč. 186, 1-2 (2002), s. 121-126 ISSN 1381-1169 Institutional research plan: CEZ:AV0Z4072921 Keywords : microwaves * tert-butylphenols * catalyst activation Subject RIV: CC - Organic Chemistry Impact factor: 1.729, year: 2002

  4. Increasing physical activity with mobile devices: a meta-analysis.

    Science.gov (United States)

    Fanning, Jason; Mullen, Sean P; McAuley, Edward

    2012-11-21

    Regular physical activity has established physical and mental health benefits; however, merely one quarter of the U.S. adult population meets national physical activity recommendations. In an effort to engage individuals who do not meet these guidelines, researchers have utilized popular emerging technologies, including mobile devices (ie, personal digital assistants [PDAs], mobile phones). This study is the first to synthesize current research focused on the use of mobile devices for increasing physical activity. To conduct a meta-analysis of research utilizing mobile devices to influence physical activity behavior. The aims of this review were to: (1) examine the efficacy of mobile devices in the physical activity setting, (2) explore and discuss implementation of device features across studies, and (3) make recommendations for future intervention development. We searched electronic databases (PubMed, PsychINFO, SCOPUS) and identified publications through reference lists and requests to experts in the field of mobile health. Studies were included that provided original data and aimed to influence physical activity through dissemination or collection of intervention materials with a mobile device. Data were extracted to calculate effect sizes for individual studies, as were study descriptives. A random effects meta-analysis was conducted using the Comprehensive Meta-Analysis software suite. Study quality was assessed using the quality of execution portion of the Guide to Community Preventative Services data extraction form. Four studies were of "good" quality and seven of "fair" quality. In total, 1351 individuals participated in 11 unique studies from which 18 effects were extracted and synthesized, yielding an overall weight mean effect size of g = 0.54 (95% CI = 0.17 to 0.91, P = .01). Research utilizing mobile devices is gaining in popularity, and this study suggests that this platform is an effective means for influencing physical activity behavior. Our focus

  5. Using microwave heating to improve the desorption efficiency of high molecular weight VOC from beaded activated carbon.

    Science.gov (United States)

    Fayaz, Mohammadreza; Shariaty, Pooya; Atkinson, John D; Hashisho, Zaher; Phillips, John H; Anderson, James E; Nichols, Mark

    2015-04-07

    Incomplete regeneration of activated carbon loaded with organic compounds results in heel build-up that reduces the useful life of the adsorbent. In this study, microwave heating was tested as a regeneration method for beaded activated carbon (BAC) loaded with n-dodecane, a high molecular weight volatile organic compound. Energy consumption and desorption efficiency for microwave-heating regeneration were compared with conductive-heating regeneration. The minimum energy needed to completely regenerate the adsorbent (100% desorption efficiency) using microwave regeneration was 6% of that needed with conductive heating regeneration, owing to more rapid heating rates and lower heat loss. Analyses of adsorbent pore size distribution and surface chemistry confirmed that neither heating method altered the physical/chemical properties of the BAC. Additionally, gas chromatography (with flame ionization detector) confirmed that neither regeneration method detectably altered the adsorbate composition during desorption. By demonstrating improvements in energy consumption and desorption efficiency and showing stable adsorbate and adsorbent properties, this paper suggests that microwave heating is an attractive method for activated carbon regeneration particularly when high-affinity VOC adsorbates are present.

  6. Microwave Ovens

    Science.gov (United States)

    ... Products and Procedures Home, Business, and Entertainment Products Microwave Ovens Share Tweet Linkedin Pin it More sharing ... 1030.10 - Microwave Ovens Required Reports for the Microwave Oven Manufacturers or Industry Exemption from Certain Reporting ...

  7. Neutron shielding and activation of the MASTU device and surrounds

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, David, E-mail: david.taylor@ccfe.ac.uk [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Lilley, Steven; Turner, Andrew [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Davis, Andrew [Now at College of Engineering, University of Wisconsin, Madison, WI 53706 (United States)

    2014-10-15

    Highlights: We model neutron shielding for the planned MASTU device; nadequacies in the existing shielding design are remedied; Levels of public exposure are considered; We model activated gamma emission for the device under a worst case scenario. Abstract: A significant functional upgrade is planned for the Mega Ampere Spherical Tokamak (MAST) device, located at Culham in the UK, including the implementation of a notably greater neutral beam injection power. This upgrade will cause the emission of a substantially increased intensity of neutron radiation for a substantially increased amount of time upon operation of the device. Existing shielding and activation precautions are shown to prove insufficient in some regards, and recommendations for improvements are made, including the following areas: shielding doors to MAST shielded facility enclosure (known as “the blockhouse”); north access tunnel; blockhouse roof; west cabling duct. In addition, some specific neutronic dose rate questions are addressed and answered; those discussed here relate to shielding penetrations and dose rate reflected from the air above the device (“skyshine”). It is shown that the alterations to shielding and area access reduce the dose rate in unrestricted areas from greater than 100 μSv/h to less than 2 μSv/h averaged over the working day. The tools used for this analysis are the MCNP (Monte Carlo N-particle) code, used to calculate the three-dimensional spatial distribution of neutron and photon dose rates in and around the device and its shields, and the nuclear inventory code FISPACT, run under the umbrella code MCR2S, used to calculate the time-dependent shutdown dose rate in the region of the device at several decay times.

  8. Microwave-assisted extraction of Nigella sativa L. essential oil and evaluation of its antioxidant activity.

    Science.gov (United States)

    Abedi, Abdol-Samad; Rismanchi, Marjan; Shahdoostkhany, Mehrnoush; Mohammadi, Abdorreza; Mortazavian, Amir Mohammad

    2017-11-01

    It has been previously reported that the essential oil of Nigella sativa L. seeds and its major active component, thymoquinone (TQ), possess a broad variety of biological activities and therapeutic properties. In this work, microwave-assisted extraction (MAE) of the essential oil from Nigella sativa L. seeds and its antioxidant activity were studied. Response surface methodology based on central composite design was used to evaluate the effects of extraction time, irradiation power and moisture content on extraction yield and TQ content. Optimal parameters obtained by CCD and RSM were extraction time 30 min, irradiation power 450 W, and moisture content 50%. The extraction yield and TQ content of the essential oil were 0.33 and 20% under the optimum conditions, respectively. In contrast, extraction yield and TQ amount of oil obtained by hydrodistillation (HD) were 0.23 and 3.71%, respectively. The main constituents of the essential oil extracted by MAE and HD were p -cymene, TQ, α-thujene and longifolene, comprising more than 60% of total peak area. The antioxidant capacity of essential oils extracted by different methods were evaluated using 2,2-diphenyl-1-picrylhydrazyl and Ferric reducing antioxidant power assays, and compared with traditional antioxidants. The results showed that MAE method was a viable alternative to HD for the essential oil extraction from N. sativa seeds due to the excellent extraction efficiency, higher thymoquinone content, and stronger antioxidant activity.

  9. Quaternized Carboxymethyl Chitosan-Based Silver Nanoparticles Hybrid: Microwave-Assisted Synthesis, Characterization and Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    Siqi Huang

    2016-06-01

    Full Text Available A facile, efficient, and eco-friendly approach for the preparation of uniform silver nanoparticles (Ag NPs was developed. The synthesis was conducted in an aqueous medium exposed to microwave irradiation for 8 min, using laboratory-prepared, water-soluble quaternized carboxymethyl chitosan (QCMC as a chemical reducer and stabilizer and silver nitrate as the silver source. The structure of the prepared QCMC was characterized using Fourier transform infrared (FT-IR and 1H nuclear magnetic resonance (NMR. The formation, size distribution, and dispersion of the Ag NPs in the QCMC matrix were determined using X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, ultraviolet-visible (UV-Vis, transmission electron microscopy (TEM, and field emission scanning electron microscope (FESEM analysis, and the thermal stability and antibacterial properties of the synthesized QCMC-based Ag NPs composite (QCMC-Ag were also explored. The results revealed that (1 QCMC was successfully prepared by grafting quaternary ammonium groups onto carboxymethyl chitosan (CMC chains under microwave irradiation in water for 90 min and this substitution appeared to have occurred at -NH2 sites on C2 position of the pyranoid ring; (2 uniform and stable spherical Ag NPs could be synthesized when QCMC was used as the reducing and stabilizing agent; (3 Ag NPs were well dispersed in the QCMC matrix with a narrow size distribiution in the range of 17–31 nm without aggregation; and (4 due to the presence of Ag NPs, the thermal stability and antibacterial activity of QCMC-Ag were dramatically improved relative to QCMC.

  10. Quaternized Carboxymethyl Chitosan-Based Silver Nanoparticles Hybrid: Microwave-Assisted Synthesis, Characterization and Antibacterial Activity.

    Science.gov (United States)

    Huang, Siqi; Wang, Jing; Zhang, Yang; Yu, Zhiming; Qi, Chusheng

    2016-06-17

    A facile, efficient, and eco-friendly approach for the preparation of uniform silver nanoparticles (Ag NPs) was developed. The synthesis was conducted in an aqueous medium exposed to microwave irradiation for 8 min, using laboratory-prepared, water-soluble quaternized carboxymethyl chitosan (QCMC) as a chemical reducer and stabilizer and silver nitrate as the silver source. The structure of the prepared QCMC was characterized using Fourier transform infrared (FT-IR) and ¹H nuclear magnetic resonance (NMR). The formation, size distribution, and dispersion of the Ag NPs in the QCMC matrix were determined using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible (UV-Vis), transmission electron microscopy (TEM), and field emission scanning electron microscope (FESEM) analysis, and the thermal stability and antibacterial properties of the synthesized QCMC-based Ag NPs composite (QCMC-Ag) were also explored. The results revealed that (1) QCMC was successfully prepared by grafting quaternary ammonium groups onto carboxymethyl chitosan (CMC) chains under microwave irradiation in water for 90 min and this substitution appeared to have occurred at -NH₂ sites on C2 position of the pyranoid ring; (2) uniform and stable spherical Ag NPs could be synthesized when QCMC was used as the reducing and stabilizing agent; (3) Ag NPs were well dispersed in the QCMC matrix with a narrow size distribiution in the range of 17-31 nm without aggregation; and (4) due to the presence of Ag NPs, the thermal stability and antibacterial activity of QCMC-Ag were dramatically improved relative to QCMC.

  11. Estimating Global Ecosystem Isohydry/Anisohydry Using Active and Passive Microwave Satellite Data

    Science.gov (United States)

    Li, Yan; Guan, Kaiyu; Gentine, Pierre; Konings, Alexandra G.; Meinzer, Frederick C.; Kimball, John S.; Xu, Xiangtao; Anderegg, William R. L.; McDowell, Nate G.; Martinez-Vilalta, Jordi; Long, David G.; Good, Stephen P.

    2017-12-01

    The concept of isohydry/anisohydry describes the degree to which plants regulate their water status, operating from isohydric with strict regulation to anisohydric with less regulation. Though some species level measures of isohydry/anisohydry exist at a few locations, ecosystem-scale information is still largely unavailable. In this study, we use diurnal observations from active (Ku-Band backscatter from QuikSCAT) and passive (X-band vegetation optical depth (VOD) from Advanced Microwave Scanning Radiometer on EOS Aqua) microwave satellite data to estimate global ecosystem isohydry/anisohydry. Here diurnal observations from both satellites approximate predawn and midday plant canopy water contents, which are used to estimate isohydry/anisohydry. The two independent estimates from radar backscatter and VOD show reasonable agreement at low and middle latitudes but diverge at high latitudes. Grasslands, croplands, wetlands, and open shrublands are more anisohydric, whereas evergreen broadleaf and deciduous broadleaf forests are more isohydric. The direct validation with upscaled in situ species isohydry/anisohydry estimates indicates that the VOD-based estimates have much better agreement than the backscatter-based estimates. The indirect validation with prior knowledge suggests that both estimates are generally consistent in that vegetation water status of anisohydric ecosystems more closely tracks environmental fluctuations of water availability and demand than their isohydric counterparts. However, uncertainties still exist in the isohydry/anisohydry estimate, primarily arising from the remote sensing data and, to a lesser extent, from the methodology. The comprehensive assessment in this study can help us better understand the robustness, limitation, and uncertainties of the satellite-derived isohydry/anisohydry estimates. The ecosystem isohydry/anisohydry has the potential to reveal new insights into spatiotemporal ecosystem response to droughts.

  12. Study of photocatalytic activities of Bi2WO6 nanoparticles synthesized by fast microwave-assisted method

    International Nuclear Information System (INIS)

    Phu, Nguyen Dang; Hoang, Luc Huy; Chen, Xiang-Bai; Kong, Meng-Hong; Wen, Hua-Chiang; Chou, Wu Ching

    2015-01-01

    We present a study of photocatalytic activities of Bi 2 WO 6 nanoparticles synthesized by fast microwave-assisted method. The photocatalytic activities of the nanoparticles were evaluated by the decolorization of methylene-blue under visible-light-irradiation. Our results show that the surface area of Bi 2 WO 6 nanoparticles plays a major role for improving photocatalytic activity, while visible-light absorption has only a weak effect on photocatalytic activity. This suggests efficient transportation of photo-generated electrons and holes to the oxidation active sites on the surface of nanoparticles, indicating Bi 2 WO 6 nanoparticles synthesized by fast microwave-assisted method are promising for achieving high photocatalytic activity under visible-light-irradiation. - Highlights: • The Bi 2 WO 6 nanoparticles were synthesized via fast microwave-assisted method. • The obtained Bi 2 WO 6 nanoparticles exhibited visible-light absorbance. • The surface area of Bi 2 WO 6 nanoparticles plays major role for improving photocatalytic activity. • The Bi 2 WO 6 nanoparticles are promising for achieving high photocatalytic activity under visible-light-irradiation

  13. Spectroscopic study of microwave induced plasmas : exploration of active and passive methods

    NARCIS (Netherlands)

    Vries, de N.

    2008-01-01

    Microwave induced plasmas (MIPs) are used for a number of high-tech applications like material processing, light generation, gas cleaning and spectrochemical analysis. Especially the feature that MIPs can be operated remotely and that the propagation of the microwaves can be manipulated with slits,

  14. Athermal alterations in the structure in the canalicular membrane and ATPase activity induced by thermal levels of microwave radiation

    International Nuclear Information System (INIS)

    Phelan, A.M.; Neubauer, C.F.; Timm, R.; Neirenberg, J.; Lange, D.G.

    1994-01-01

    Sprague-Dawley rats (200-250 g) were exposed 30 min/day for 4 days to thermogenic levels (rectal temperature increase of 2.2 degrees C) of microwave radiation [2.45 GHz, 80 mW/cm 2 , continuous-wave mode (CW)] or to a radiant heat source resulting in an equivalent increase in body temperature of 2.2 degrees C. On the fifth day the animals were sacrificed and their livers removed. The canalicular membranes were isolated and evaluated for adenosinetriphosphatase (ATPase) activity, total fatty acid composition and membrane fluidity characteristics. Mg ++ -ATPase activity (V max ) decreased by 48.5% in the group exposed to microwave radiation, with no significant change in the group exposed to radiant heat. The decrease in Mg ++ -ATPase was partially compensated by a concomitant increase in Na + /K + -ATPase activity (170% increase in V max over control) in animals exposed to microwave radiation, while no change occurred in the group exposed to radiant heat. This alteration in ATPase activity in the group exposed to microwave radiation is associated with a large decrease in the ratio of saturated to unsaturated fatty acids. Conversely, the group exposed to radiant heat had an increase in the ratio of saturated to unsaturated fatty acids. The most dramatic changes were found in the levels of arachidonic acid. Finally, the electron paramagnetic resonance (EPR) spin label technique used to measure the fluidity of the canalicular membranes of the animals in the three groups (sham, microwave radiation and radiant heat) indicated that the results were different in the three groups, reflecting the changes found in their fatty acid composition. The physiological response to open-quotes equivalentclose quotes thermal loads in rats is expressed differently for different types of energy sources. Possible mechanisms producing these divergent thermogenic responses are discussed. 34 refs., 3 figs., 2 tabs

  15. White noise of Nb-based microwave superconducting quantum interference device multiplexers with NbN coplanar resonators for readout of transition edge sensors

    Science.gov (United States)

    Kohjiro, Satoshi; Hirayama, Fuminori; Yamamori, Hirotake; Nagasawa, Shuichi; Fukuda, Daiji; Hidaka, Mutsuo

    2014-06-01

    White noise of dissipationless microwave radio frequency superconducting quantum interference device (RF-SQUID) multiplexers has been experimentally studied to evaluate their readout performance for transition edge sensor (TES) photon counters ranging from near infrared to gamma ray. The characterization has been carried out at 4 K, first to avoid the low-frequency fluctuations present at around 0.1 K, and second, for a feasibility study of readout operation at 4 K for extended applications. To increase the resonant Q at 4 K and maintain low noise SQUID operation, multiplexer chips consisting of niobium nitride (NbN)-based coplanar-waveguide resonators and niobium (Nb)-based RF-SQUIDs have been developed. This hybrid multiplexer exhibited 1 × 104 ≤ Q ≤ 2 × 104 and the square root of spectral density of current noise referred to the SQUID input √SI = 31 pA/√Hz. The former and the latter are factor-of-five and seven improvements from our previous results on Nb-based resonators, respectively. Two-directional readout on the complex plane of the transmission component of scattering matrix S21 enables us to distinguish the flux noise from noise originating from other sources, such as the cryogenic high electron mobility transistor (HEMT) amplifier. Systematic noise measurements with various microwave readout powers PMR make it possible to distinguish the contribution of noise sources within the system as follows: (1) The achieved √SI is dominated by the Nyquist noise from a resistor at 4 K in parallel to the SQUID input coil which is present to prevent microwave leakage to the TES. (2) The next dominant source is either the HEMT-amplifier noise (for small values of PMR) or the quantization noise due to the resolution of 300-K electronics (for large values of PMR). By a decrease of these noise levels to a degree that is achievable by current technology, we predict that the microwave RF-SQUID multiplexer can exhibit √SI ≤ 5 pA/√Hz, i.e., close to √SI of

  16. White noise of Nb-based microwave superconducting quantum interference device multiplexers with NbN coplanar resonators for readout of transition edge sensors

    International Nuclear Information System (INIS)

    Kohjiro, Satoshi; Hirayama, Fuminori; Yamamori, Hirotake; Nagasawa, Shuichi; Fukuda, Daiji; Hidaka, Mutsuo

    2014-01-01

    White noise of dissipationless microwave radio frequency superconducting quantum interference device (RF-SQUID) multiplexers has been experimentally studied to evaluate their readout performance for transition edge sensor (TES) photon counters ranging from near infrared to gamma ray. The characterization has been carried out at 4 K, first to avoid the low-frequency fluctuations present at around 0.1 K, and second, for a feasibility study of readout operation at 4 K for extended applications. To increase the resonant Q at 4 K and maintain low noise SQUID operation, multiplexer chips consisting of niobium nitride (NbN)-based coplanar-waveguide resonators and niobium (Nb)-based RF-SQUIDs have been developed. This hybrid multiplexer exhibited 1 × 10 4  ≤ Q ≤ 2 × 10 4 and the square root of spectral density of current noise referred to the SQUID input √S I  = 31 pA/√Hz. The former and the latter are factor-of-five and seven improvements from our previous results on Nb-based resonators, respectively. Two-directional readout on the complex plane of the transmission component of scattering matrix S 21 enables us to distinguish the flux noise from noise originating from other sources, such as the cryogenic high electron mobility transistor (HEMT) amplifier. Systematic noise measurements with various microwave readout powers P MR make it possible to distinguish the contribution of noise sources within the system as follows: (1) The achieved √S I is dominated by the Nyquist noise from a resistor at 4 K in parallel to the SQUID input coil which is present to prevent microwave leakage to the TES. (2) The next dominant source is either the HEMT-amplifier noise (for small values of P MR ) or the quantization noise due to the resolution of 300-K electronics (for large values of P MR ). By a decrease of these noise levels to a degree that is achievable by current technology, we predict that the microwave RF-SQUID multiplexer can exhibit

  17. Simultaneous microwave-assisted synthesis, characterization, thermal stability, and antimicrobial activity of cellulose/AgCl nanocomposites

    International Nuclear Information System (INIS)

    Li, Shu-Ming; Fu, Lian-Hua; Ma, Ming-Guo; Zhu, Jie-Fang; Sun, Run-Cang; Xu, Feng

    2012-01-01

    By means of a simultaneous microwave-assisted method and a simple chemical reaction, cellulose/AgCl nanocomposites have been successfully synthesized using cellulose solution and AgNO 3 in N,N-dimethylacetamide (DMAc) solvent. The cellulose solution was firstly prepared by the dissolution of the microcrystalline cellulose and lithium chloride (LiCl) in DMAc. DMAc acts as both a solvent and a microwave absorber. LiCl was used as the reactant to fabricate AgCl crystals. The effects of the heating time and heating temperature on the products were studied. This method is based on the simultaneous formation of AgCl nanoparticles and precipitation of the cellulose, leading to a homogeneous distribution of AgCl nanoparticles in the cellulose matrix. The experimental results confirmed the formation of cellulose/AgCl nanocomposites with high-purity, good thermal stability and antimicrobial activity. This rapid, green and environmentally friendly microwave-assisted method opens a new window to the high value-added applications of biomass. -- Highlights: ► Cellulose/AgCl nanocomposites have been synthesized by microwave method. ► Effect of heating temperature on the nanocomposites was researched. ► Thermal stability of the nanocomposites was investigated. ► Cellulose/AgCl nanocomposites had good antimicrobial activity. ► This method is based on the simultaneous formation of AgCl and cellulose.

  18. MAPSM: A Spatio-Temporal Algorithm for Merging Soil Moisture from Active and Passive Microwave Remote Sensing

    Directory of Open Access Journals (Sweden)

    Sat Kumar Tomer

    2016-12-01

    Full Text Available Availability of soil moisture observations at a high spatial and temporal resolution is a prerequisite for various hydrological, agricultural and meteorological applications. In the current study, a novel algorithm for merging soil moisture from active microwave (SAR and passive microwave is presented. The MAPSM algorithm—Merge Active and Passive microwave Soil Moisture—uses a spatio-temporal approach based on the concept of the Water Change Capacity (WCC which represents the amplitude and direction of change in the soil moisture at the fine spatial resolution. The algorithm is applied and validated during a period of 3 years spanning from 2010 to 2013 over the Berambadi watershed which is located in a semi-arid tropical region in the Karnataka state of south India. Passive microwave products are provided from ESA Level 2 soil moisture products derived from Soil Moisture and Ocean Salinity (SMOS satellite (3 days temporal resolution and 40 km nominal spatial resolution. Active microwave are based on soil moisture retrievals from 30 images of RADARSAT-2 data (24 days temporal resolution and 20 m spatial resolution. The results show that MAPSM is able to provide a good estimate of soil moisture at a spatial resolution of 500 m with an RMSE of 0.025 m3/m3 and 0.069 m3/m3 when comparing it to soil moisture from RADARSAT-2 and in-situ measurements, respectively. The use of Sentinel-1 and RISAT products in MAPSM algorithm is envisioned over other areas where high number of revisits is available. This will need an update of the algorithm to take into account the angle sampling and resolution of Sentinel-1 and RISAT data.

  19. Active Vibration Isolation Devices with Inertial Servo Actuators

    Science.gov (United States)

    Melik-Shakhnazarov, V. A.; Strelov, V. I.; Sofiyanchuk, D. V.; Tregubenko, A. A.

    2018-03-01

    The use of active vibration isolation devices (AVIDs) in aerospace engineering is subject to the following restrictions. First, the volume for installing additional devices is always limited in instrument racks and compartments. Secondly, in many cases, it is impossible to add supports for servo actuators for fundamental or design considerations. In the paper, it has been shown that this problem can be solved if the inertial servo actuators are used in AVIDs instead of reference actuators. A transfer function has been theoretically calculated for an AVID controlled by inertial actuators. It has been shown that the volume of a six-mode single-housing AVID with inertial actuators can be 2-2.5 times smaller than that of devices with support actuators.

  20. Increasing physical activity through mobile device interventions: A systematic review.

    Science.gov (United States)

    Muntaner, Adrià; Vidal-Conti, Josep; Palou, Pere

    2016-09-01

    Physical inactivity is a health problem that affects people worldwide and has been identified as the fourth largest risk factor for overall mortality (contributing to 6% of deaths globally). Many researchers have tried to increase physical activity levels through traditional methods without much success. Thus, many researchers are turning to mobile technology as an emerging method for changing health behaviours. This systematic review sought to summarise and update the existing scientific literature on increasing physical activity through mobile device interventions, taking into account the methodological quality of the studies. The articles were identified by searching the PubMed, SCOPUS and SPORTDiscus databases for studies published between January 2003 and December 2013. Studies investigating efforts to increase physical activity through mobile phone or even personal digital assistant interventions were included. The search results allowed the inclusion of 11 studies that gave rise to 12 publications. Six of the articles included in this review reported significant increases in physical activity levels. The number of studies using mobile devices for interventions has increased exponentially in the last few years, but future investigations with better methodological quality are needed to draw stronger conclusions regarding how to increase physical activity through mobile device interventions. © The Author(s) 2015.

  1. Error Characterisation and Merging of Active and Passive Microwave Soil Moisture Data Sets

    Science.gov (United States)

    Wagner, Wolfgang; Gruber, Alexander; de Jeu, Richard; Parinussa, Robert; Chung, Daniel; Dorigo, Wouter; Reimer, Christoph; Kidd, Richard

    2015-04-01

    As part of the Climate Change Initiative (CCI) programme of the European Space Agency (ESA) a data fusion system has been developed which is capable of ingesting surface soil moisture data derived from active and passive microwave sensors (ASCAT, AMSR-E, etc.) flown on different satellite platforms and merging them to create long and consistent time series of soil moisture suitable for use in climate change studies. The so-created soil moisture data records (latest version: ESA CCI SM v02.1 released on 5/12/2014) are freely available and can be obtained from http://www.esa-soilmoisture-cci.org/. As described by Wagner et al. (2012) the principle steps of the data fusion process are: 1) error characterisation, 2) matching to account for data set specific biases, and 3) merging. In this presentation we present the current data fusion process and discuss how new error characterisation methods, such as the increasingly popular triple collocation method as discussed for example by Zwieback et al. (2012) may be used to improve it. The main benefit of an improved error characterisation would be a more reliable identification of the best performing microwave soil moisture retrieval(s) for each grid point and each point in time. In case that two or more satellite data sets provides useful information, the estimated errors can be used to define the weights with which each satellite data set are merged, i.e. the lower its error the higher its weight. This is expected to bring a significant improvement over the current data fusion scheme which is not yet based on quantitative estimates of the retrieval errors but on a proxy measure, namely the vegetation optical depth (Dorigo et al., 2015): over areas with low vegetation passive soil moisture retrievals are used, while over areas with moderate vegetation density active retrievals are used. In transition areas, where both products correlate well, both products are being used in a synergistic way: on time steps where only one of

  2. Creating Active Device Materials for Nanoelectronics Using Block Copolymer Lithography

    Directory of Open Access Journals (Sweden)

    Cian Cummins

    2017-09-01

    Full Text Available The prolonged and aggressive nature of scaling to augment the performance of silicon integrated circuits (ICs and the technical challenges and costs associated with this has led to the study of alternative materials that can use processing schemes analogous to semiconductor manufacturing. We examine the status of recent efforts to develop active device elements using nontraditional lithography in this article, with a specific focus on block copolymer (BCP feature patterning. An elegant route is demonstrated using directed self-assembly (DSA of BCPs for the fabrication of aligned tungsten trioxide (WO3 nanowires towards nanoelectronic device application. The strategy described avoids conventional lithography practices such as optical patterning as well as repeated etching and deposition protocols and opens up a new approach for device development. Nanoimprint lithography (NIL silsesquioxane (SSQ-based trenches were utilized in order to align a cylinder forming poly(styrene-block-poly(4-vinylpyridine (PS-b-P4VP BCP soft template. We outline WO3 nanowire fabrication using a spin-on process and the symmetric current-voltage characteristics of the resulting Ti/Au (5 nm/45 nm contacted WO3 nanowires. The results highlight the simplicity of a solution-based approach that allows creating active device elements and controlling the chemistry of specific self-assembling building blocks. The process enables one to dictate nanoscale chemistry with an unprecedented level of sophistication, forging the way for next-generation nanoelectronic devices. We lastly outline views and future research studies towards improving the current platform to achieve the desired device performance.

  3. Creating Active Device Materials for Nanoelectronics Using Block Copolymer Lithography.

    Science.gov (United States)

    Cummins, Cian; Bell, Alan P; Morris, Michael A

    2017-09-30

    The prolonged and aggressive nature of scaling to augment the performance of silicon integrated circuits (ICs) and the technical challenges and costs associated with this has led to the study of alternative materials that can use processing schemes analogous to semiconductor manufacturing. We examine the status of recent efforts to develop active device elements using nontraditional lithography in this article, with a specific focus on block copolymer (BCP) feature patterning. An elegant route is demonstrated using directed self-assembly (DSA) of BCPs for the fabrication of aligned tungsten trioxide (WO₃) nanowires towards nanoelectronic device application. The strategy described avoids conventional lithography practices such as optical patterning as well as repeated etching and deposition protocols and opens up a new approach for device development. Nanoimprint lithography (NIL) silsesquioxane (SSQ)-based trenches were utilized in order to align a cylinder forming poly(styrene)- block -poly(4-vinylpyridine) (PS- b -P4VP) BCP soft template. We outline WO₃ nanowire fabrication using a spin-on process and the symmetric current-voltage characteristics of the resulting Ti/Au (5 nm/45 nm) contacted WO₃ nanowires. The results highlight the simplicity of a solution-based approach that allows creating active device elements and controlling the chemistry of specific self-assembling building blocks. The process enables one to dictate nanoscale chemistry with an unprecedented level of sophistication, forging the way for next-generation nanoelectronic devices. We lastly outline views and future research studies towards improving the current platform to achieve the desired device performance.

  4. Error characterisation of global active and passive microwave soil moisture datasets

    Directory of Open Access Journals (Sweden)

    W. A. Dorigo

    2010-12-01

    Full Text Available Understanding the error structures of remotely sensed soil moisture observations is essential for correctly interpreting observed variations and trends in the data or assimilating them in hydrological or numerical weather prediction models. Nevertheless, a spatially coherent assessment of the quality of the various globally available datasets is often hampered by the limited availability over space and time of reliable in-situ measurements. As an alternative, this study explores the triple collocation error estimation technique for assessing the relative quality of several globally available soil moisture products from active (ASCAT and passive (AMSR-E and SSM/I microwave sensors. The triple collocation is a powerful statistical tool to estimate the root mean square error while simultaneously solving for systematic differences in the climatologies of a set of three linearly related data sources with independent error structures. Prerequisite for this technique is the availability of a sufficiently large number of timely corresponding observations. In addition to the active and passive satellite-based datasets, we used the ERA-Interim and GLDAS-NOAH reanalysis soil moisture datasets as a third, independent reference. The prime objective is to reveal trends in uncertainty related to different observation principles (passive versus active, the use of different frequencies (C-, X-, and Ku-band for passive microwave observations, and the choice of the independent reference dataset (ERA-Interim versus GLDAS-NOAH. The results suggest that the triple collocation method provides realistic error estimates. Observed spatial trends agree well with the existing theory and studies on the performance of different observation principles and frequencies with respect to land cover and vegetation density. In addition, if all theoretical prerequisites are fulfilled (e.g. a sufficiently large number of common observations is available and errors of the different

  5. Microwave discharge electrodeless lamps (MDEL). III. A novel tungsten-triggered MDEL device emitting VUV and UVC radiation for use in wastewater treatment.

    Science.gov (United States)

    Horikoshi, Satoshi; Miura, Takashi; Kajitani, Masatsugu; Serpone, Nick

    2008-03-01

    Exposure to low doses of the xenoestrogen bisphenol A (BPA) and to the hormonal 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide, an environmental endocrine disruptor, can have serious health consequences such as the induction of mammary gland ductal hyperplasias and carcinoma (LaChapelle et al., Reprod. Toxicol., 2007, 23, 20; Murray et al., Reprod. Toxicol., 2007, 23, 383). To the extent that these toxins are present in wastewaters (Donald et al., Sci. Total Environ. 1999, 231, 173; Brotons et al., Environ. Health Perspect. 1994, 103, 608; Olea et al., Environ. Health Perspect. 1996, 104, 298; Biles et al., J. Agric. Food Chem. 1997, 45, 3541; Markey et al., J. Steroid Biochem. Mol. Biol., 2003, 83, 235), we examined their oxidative destruction in aqueous media by a novel light source. A tungsten-triggered microwave discharge electrodeless lamp (W-MDEL) was fabricated for possible use in wastewater treatment using vacuum UV-transparent quartz in which a tungsten trigger, also embedded in quartz, was attached to the MDEL to aid in the self-ignition of the lamp on irradiation at low microwave power levels. The quantity of mercury gas in the W-MDEL was optimized by monitoring the continuous radiation and peak intensities of the emitted light in the vacuum UV (VUV) and UVC regions. The usefulness of the W-MDEL device was assessed through the degradation of 2,4-D and BPA in air-equilibrated aqueous media and in oxygen-saturated aqueous media. Enhanced degradation of these two xenoestrogenic toxins was achieved by increasing the number of W-MDEL devices while keeping constant the microwave radiation feeding each W-MDEL lamp. This novel lamp provides an additional light source in the photooxidation of environmental contaminants without the need for a metal-oxide photocatalyst. Under our conditions, process dynamics using the W-MDEL light source are greater than with the more conventional photochemical methods that employ low-pressure Hg arc electrode lamps in synthetic

  6. Enhanced photocatalytic activity of ZnO–graphene nanocomposites prepared by microwave synthesis

    International Nuclear Information System (INIS)

    Herring, Natalie P.; Almahoudi, Serial H.; Olson, Chelsea R.; El-Shall, M. Samy

    2012-01-01

    This work reports a simple one-step synthesis of ZnO nanopyramids supported on reduced graphene oxide (RGO) nanosheets using microwave irradiation (MWI) of zinc acetate and GO in the presence of a mixture of oleic acid and oleylamine. The rapid decomposition of zinc acetate by MWI in the presence of the mixture of oleic acid and oleylamine results in the formation of hexagonal ZnO nanopyramids. GO has a high affinity for absorbing MWI, which results in a high local heating effect around the GO nanosheets and facilitates the reduction of GO by the oleylamine. The RGO nanosheets act as heterogeneous surface sites for the nucleation and growth of the ZnO nanopyramids. Using ligand exchange, the ZnO–RGO nanocomposites can be dispersed in an aqueous medium, thus allowing their use as photocatalysts for the degradation of the malachite green dye in water. The ZnO–RGO nanocomposites show enhanced photocatalytic activity for the degradation of the dye over the unsupported ZnO nanopyramids. The enhanced activity is attributed to efficient charge transfer of the photogenerated electrons in the conduction band of ZnO to graphene. This enhances the oxidative pathway of the holes generated in the valence band of ZnO which can effectively lead to the degradation and mineralization of the malachite green. The ZnO nanopyramids supported on RGO could have improved performance in other photocatalytic reactions and also in solar energy conversion.

  7. Passive and active RF-microwave circuits course and exercises with solutions

    CERN Document Server

    Jarry, Pierre

    2015-01-01

    Microwave and radiofrequency (RF) circuits play an important role in communication systems. Due to the proliferation of radar, satellite, and mobile wireless systems, there is a need for design methods that can satisfy the ever increasing demand for accuracy, reliability, and fast development times. This book explores the principal elements for receiving and emitting signals between Earth stations, satellites, and RF (mobile phones) in four parts; the theory and realization of couplers, computation and realization of microwave and RF filters, amplifiers and microwave and RF oscillators. Pas

  8. Effect of ultrasonic and microwave disintegration on physico-chemical and biodegradation characteristics of waste-activated sludge.

    Science.gov (United States)

    Doğruel, Serdar; Özgen, Aslı Sedem

    2017-04-01

    The purpose of this study was to investigate the effect of ultrasonic and microwave disintegration on physico-chemical and biodegradability properties of waste-activated sludge (WAS) from a municipal wastewater treatment plant. Another aim was to carry out particle size distribution (PSD) analysis as an integral component of sludge characterization to highlight the transformation mechanisms involved in pretreatment processes and better understand the biodegradation patterns of sonicated and irradiated WAS liquids examined by means of respirometric measurements. Various combinations of sonication and microwave irradiation parameters were applied to optimize operating conditions. The optimum ultrasonic density was determined as 1.5 W/mL, and energy dosages lower than 30,000 kJ/kg TS resulted in a fairly linear increase in the soluble chemical oxygen demand (SCOD) release. An irradiation time of 10 min and a temperature of 175°C were selected as the optimum microwave pretreatment conditions for sludge liquefaction. The most apparent impact of ultrasonication on the PSD of COD was the shifting of the peak at the particulate fraction (>1600 nm) toward the lowest size range (<2 nm). Microwave heating at the selected experimental conditions and ultrasonic pretreatment at 30,000 kJ/kg TS exhibited comparable size distribution and biodegradation characteristics to those of domestic sewage.

  9. Microwave-assisted extraction of silkworm pupal oil and evaluation of its fatty acid composition, physicochemical properties and antioxidant activities.

    Science.gov (United States)

    Hu, Bin; Li, Cheng; Zhang, Zhiqing; Zhao, Qing; Zhu, Yadong; Su, Zhao; Chen, Yizi

    2017-09-15

    Microwave-assisted extraction (MAE) of oil from silkworm pupae was firstly performed in the present research. The response surface methodology was applied to optimize the parameters for MAE. The yield of oil by MAE was 30.16% under optimal conditions of a mixed solvent consisting of ethanol and n-hexane (1:1, v/v), microwave power (360W), liquid to solid ratio (7.5/1mL/g), microwave time (29min). Moreover, oil extracted by MAE was quantitatively (yield) and qualitatively (fatty acid profile) similar to those obtained using Soxhlet extraction (SE), but oil extracted by MAE exhibited favourable physicochemical properties and oxidation stability. Additionally, oil extracted by MAE had a higher content of total phenolic, and it showed stronger antioxidant activities. Scanning electron microscopy revealed that microwave technique efficiently promoted the release of oil by breaking down the cell structure of silkworm pupae. Therefore, MAE can be an effective method for the silkworm pupal oil extraction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Advances in microwaves 4

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 4 covers some innovations in the devices and applications of microwaves. This volume contains three chapters and begins with a discussion of the application of microwave phasers and time delay elements as beam steering elements in array radars. The next chapter provides first an overview of the technical aspects and different types of millimeter waveguides, followed by a survey of their application to railroads. The last chapter examines the general mode of conversion properties of nonuniform waveguides, such as waveguide tapers, using converted Maxwell's equatio

  11. Frequency-domain cascading microwave superconducting quantum interference device multiplexers; beyond limitations originating from room-temperature electronics

    Science.gov (United States)

    Kohjiro, Satoshi; Hirayama, Fuminori

    2018-07-01

    A novel approach, frequency-domain cascading microwave multiplexers (MW-Mux), has been proposed and its basic operation has been demonstrated to increase the number of pixels multiplexed in a readout line U of MW-Mux for superconducting detector arrays. This method is an alternative to the challenging development of wideband, large power, and spurious-free room-temperature (300 K) electronics. The readout system for U pixels consists of four main parts: (1) multiplexer chips connected in series those contain U superconducting resonators in total. (2) A cryogenic high-electron-mobility transistor amplifier (HEMT). (3) A 300 K microwave frequency comb generator based on N(≡U/M) parallel units of digital-to-analog converters (DAC). (4) N parallel units of 300 K analog-to-digital converters (ADC). Here, M is the number of tones each DAC produces and each ADC handles. The output signal of U detectors multiplexed at the cryogenic stage is transmitted through a cable to the room temperature and divided into N processors where each handles M pixels. Due to the reduction factor of 1/N, U is not anymore dominated by the 300 K electronics but can be increased up to the potential value determined by either the bandwidth or the spurious-free power of the HEMT. Based on experimental results on the prototype system with N = 2 and M = 3, neither excess inter-pixel crosstalk nor excess noise has been observed in comparison with conventional MW-Mux. This indicates that the frequency-domain cascading MW-Mux provides the full (100%) usage of the HEMT band by assigning N 300 K bands on the frequency axis without inter-band gaps.

  12. Variable Power, Short Microwave Pulses Generation using a CW Magnetron

    Directory of Open Access Journals (Sweden)

    CIUPA, R.

    2011-05-01

    Full Text Available Fine control of microwave power radiation in medical and scientific applications is a challenging task. Since a commercial Continuous Wave (CW magnetron is the most inexpensive microwave device available today on the market, it becomes the best candidate for a microwave power generator used in medical diathermy and hyperthermia treatments or high efficiency chemical reactions using microwave reactors as well. This article presents a new method for driving a CW magnetron with short pulses, using a modified commercial Zero Voltage Switching (ZVS inverter, software driven by a custom embedded system. The microwave power generator designed with this method can be programmed for output microwave pulses down to 1% of the magnetron's power and allows microwave low frequency pulse modulation in the range of human brain electrical activity, intended for medical applications. Microwave output power continuous control is also possible with the magnetron running in the oscillating area, using a dual frequency Pulse Width Modulation (PWM, where the low frequency PWM pulse is modulating a higher resonant frequency required by the ZVS inverter's transformer. The method presented allows a continuous control of both power and energy (duty-cycle at the inverter's output.

  13. An active radon sampling device for high humidity places

    Energy Technology Data Exchange (ETDEWEB)

    Legarda, F. [Department of Nuclear Engineering and Fluid Mechanics, University of the Basque Country (UPV/EHU), Alameda Urquijo s/n 48013 Bilbao (Spain); Idoeta, R., E-mail: raquel.idoeta@ehu.e [Department of Nuclear Engineering and Fluid Mechanics, University of the Basque Country (UPV/EHU), Alameda Urquijo s/n 48013 Bilbao (Spain); Alegria, N.; Herranz, M. [Department of Nuclear Engineering and Fluid Mechanics, University of the Basque Country (UPV/EHU), Alameda Urquijo s/n 48013 Bilbao (Spain)

    2010-01-15

    An active radon measurement device has been developed to be used in workplaces with a relative humidity of 100% for spot measurements of radon concentration. A mathematical model based on the convective-diffusive transport equation is used in the design of this system, which has been used to measure the radon concentration in the Pozalagua cave (Biscay, at Northern of Spain). From the obtained radon values the public and workers doses have been obtained.

  14. HERMA-Heartbeat Microwave Authentication

    Science.gov (United States)

    Lux, James Paul (Inventor); Chow, Edward (Inventor); McKee, Michael Ray (Inventor); Haque, Salman-ul Mohammed (Inventor); Tkacenko, Andre (Inventor)

    2018-01-01

    Systems and methods for identifying and/or authenticating individuals utilizing microwave sensing modules are disclosed. A HEaRtbeat Microwave Authentication (HERMA) system can enable the active identification and/or authentication of a user by analyzing reflected RF signals that contain a person's unique characteristics related to their heartbeats. An illumination signal is transmitted towards a person where a reflected signal captures the motion of the skin and tissue (i.e. displacement) due to the person's heartbeats. The HERMA system can utilize existing transmitters in a mobile device (e.g. Wi-Fi, Bluetooth, Cellphone signals) as the illumination source with at least one external receive antenna. The received reflected signals can be pre-processed and analyzed to identify and/or authenticate a user.

  15. Wireless device for activation of an underground shock wave absorber

    Science.gov (United States)

    Chikhradze, M.; Akhvlediani, I.; Bochorishvili, N.; Mataradze, E.

    2011-10-01

    The paper describes the mechanism and design of the wireless device for activation of energy absorber for localization of blast energy in underground openings. The statistics shows that the greatest share of accidents with fatal results associate with explosions in coal mines due to aero-methane and/or air-coal media explosion. The other significant problem is terrorist or accidental explosions in underground structures. At present there are different protective systems to reduce the blast energy. One of the main parts of protective Systems is blast Identification and Registration Module. The works conducted at G. Tsulukidze Mining Institute of Georgia enabled to construct the wireless system of explosion detection and mitigation of shock waves. The system is based on the constant control on overpressure. The experimental research continues to fulfill the system based on both threats, on the constant control on overpressure and flame parameters, especially in underground structures and coal mines. Reaching the threshold value of any of those parameters, the system immediately starts the activation. The absorber contains a pyrotechnic device ensuring the discharge of dispersed water. The operational parameters of wireless device and activation mechanisms of pyrotechnic element of shock wave absorber are discussed in the paper.

  16. Synergistic pretreatment of waste activated sludge using CaO_2 in combination with microwave irradiation to enhance methane production during anaerobic digestion

    International Nuclear Information System (INIS)

    Wang, Jie; Li, Yongmei

    2016-01-01

    Highlights: • CaO_2/MW pretreatment synergistically enhanced WAS solubilization and CH_4 production. • MW irradiation facilitated more "·OH generation from CaO_2. • The optimal pretreatment condition for methane production was determined. • The growths of both hydrogenotrophic and acetate-utilizing methanogens were promoted. • The dewaterability of WAS was improved considerably by CaO_2/MW treatment. - Abstract: To investigate the effects of combined calcium peroxide (CaO_2) and microwave pretreatment on anaerobic digestion of waste activated sludge, lab-scale experiments were conducted to measure the solubilization, biodegradation, and dewaterability of the waste activated sludge. Additionally, the synergistic effects between CaO_2 and microwave were studied, and the microbial activity and methanogenic archaea community structure were analyzed. Combined pretreatment considerably facilitated the solubilization and subsequent anaerobic digestion of the waste activated sludge. The optimal pretreatment condition was CaO_2 (0.1 g/gVSS)/microwave (480 W, 2 min) for methane production during the subsequent anaerobic digestion process. Under this condition, 80.2% higher CH_4 accumulation yield was achieved after 16 d of anaerobic digestion when compared with the control. The synergistic effects of CaO_2/microwave pretreatment resulted from the different mechanisms of CaO_2 and microwave treatments. Further, microwave irradiation increased "·OH generation from CaO_2 and significantly alleviated the inhibitory effect of CaO_2 on methanogens. The activities of hydrolytic enzymes and acid-forming enzymes in the waste activated sludge were improved after CaO_2 (0.1 g/gVSS)/microwave (480 W, 2 min) pretreatment. Methanogenesis enzyme activity was also higher after CaO_2 treatment (0.1 g/gVSS)/microwave (480 W, 2 min) following a lag period. Illumina MiSeq sequencing analysis indicated that acetate-utilizing methanogen (Methanosaeta sp.) and H_2/CO_2-utilizing

  17. Microwave mediated synthesis of spiro-(indoline-isoxazolidines): mechanistic study and biological activity evaluation

    DEFF Research Database (Denmark)

    Raunak, R.; Kumar, Vineet; Mukherjee, Shubhasish

    2005-01-01

    Regioisomeric spiro-(indoline-isoxazolidines) have been synthesized in moderate yields by the cycloaddition reaction between ethyl (3-indolylidene)acetate and various substituted α,N-diphenylnitrones, using environmentally benign microwave technology. A novel concerted reaction mechanism is descr......Regioisomeric spiro-(indoline-isoxazolidines) have been synthesized in moderate yields by the cycloaddition reaction between ethyl (3-indolylidene)acetate and various substituted α,N-diphenylnitrones, using environmentally benign microwave technology. A novel concerted reaction mechanism...

  18. Microwave imaging

    CERN Document Server

    Pastorino, Matteo

    2010-01-01

    An introduction to the most relevant theoretical and algorithmic aspects of modern microwave imaging approaches Microwave imaging-a technique used in sensing a given scene by means of interrogating microwaves-has recently proven its usefulness in providing excellent diagnostic capabilities in several areas, including civil and industrial engineering, nondestructive testing and evaluation, geophysical prospecting, and biomedical engineering. Microwave Imaging offers comprehensive descriptions of the most important techniques so far proposed for short-range microwave imaging-in

  19. Active microwave measurements of sea ice under fall conditions: The RADARSAT/FIREX fall experiment. [in the Canadian Arctic

    Science.gov (United States)

    Onstott, R. G.; Kim, Y. S.; Moore, R. K.

    1984-01-01

    A series of measurements of the active microwave properties of sea ice under fall growing conditions was conducted. Ice in the inland waters of Mould Bay, Crozier Channel, and intrepid inlet and ice in the Arctic Ocean near Hardinge Bay was investigated. Active microwave data were acquired using a helicopter borne scatterometer. Results show that multiyear ice frozen in grey or first year ice is easily detected under cold fall conditions. Multiyear ice returns were dynamic due to response to two of its scene constituents. Floe boundaries between thick and thin ice are well defined. Multiyear pressure ridge returns are similar in level to background ice returns. Backscatter from homogeneous first year ice is seen to be primarily due to surface scattering. Operation at 9.6 GHz is more sensitive to the detailed changes in scene roughness, while operation at 5.6 GHz seems to track roughness changes less ably.

  20. Low-cost metal oxide activated carbon prepared and modified by microwave heating method for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Moradi, S. E. [Islamic Azad University, Sari (Iran, Islamic Republic of)

    2014-09-15

    Novel microporous activated carbon (MAC) with high surface area and pore volume has been synthesized by microwave heating. Iron oxide nanoparticles were loaded into MAC by using Fe(NO{sub 3}){sub 3}·9H{sub 2}O followed by microwave irradiation for up to five minutes. The surface modified microporous activated carbon was characterized by BET, XRD, SEM and thermogravimetric examinations. Adsorption data of H{sub 2} on the unmodified and modified MACs were collected with PCT method for a pressure range up to 120 bar at 303 K. Greater hydrogen adsorption was observed on the carbon adsorbents doped with 1.45 wt% of iron oxide nanoparticle loaded due to the joint properties of hydrogen adsorption on the carbon surface and the spill-over of hydrogen molecules into carbon structures.

  1. Microwave synthesis, spectral, thermal, and antimicrobial activities of some transition metal complexes involving 5-bromosalicylaldehyde moiety

    Directory of Open Access Journals (Sweden)

    Rajendra K. Jain

    2012-07-01

    Full Text Available The coordination complexes of Co(II, Ni(II and Cu(II derived from 5-bromosalicylidene-3,4-dimethylaniline (BSMA and 5-bromosalicylidene-3,4-dichloroaniline (BSCA have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, FT-IR, molar conductance, electronic spectra, 1H-NMR, FAB-mass, ESR, magnetic susceptibility, electrical conductivity and thermal analysis. The complexes are coloured and stable in air. Analytical data revealed that all the complexes exhibited 1:2 (metal: ligand ratio with coordination number 4 or 6. IR data shows that the ligand coordinates with the metal ions in a bidentate manner through the phenolic oxygen and azomethine nitrogen. FAB-mass and thermal data show degradation pattern of the complexes. Solid state electrical conductivity studies reflect semiconducting nature of the complexes. The Schiff base and metal complexes show a good activity against the Gram-positive bacteria; Staphylococcus aureus and Gram-negative bacteria; Escherichia coli and fungi Aspergillus niger and Candida albicans.

  2. Activated carbon as catalyst for microwave-assisted wet peroxide oxidation of aromatic hydrocarbons.

    Science.gov (United States)

    Garcia-Costa, Alicia L; Lopez-Perela, Lucia; Xu, Xiyan; Zazo, Juan A; Rodriguez, Juan J; Casas, Jose A

    2018-05-21

    This paper addresses the removal of four aromatic hydrocarbons typically found in petrochemical wastewater: benzene (B), toluene (T), o-xylene (X), and naphthalene (N), by microwave-assisted catalytic wet peroxide oxidation (MW-CWPO) using activated carbon (AC) as catalyst. Under the studied conditions, complete pollutant elimination (B, 1.28 mM; T, 1.09 mM; X, 0.94 mM; and N, 0.78 mM) was achieved, with more than 90% TOC removal after only 15-min reaction time, working at 120 °C, pH 0  = 3, AC at 1 g L -1 , and H 2 O 2 at the stoichiometric dose. Furthermore, in the case of toluene, naphthalene, and xylene, the hydroxylation and breakdown of the ring is very rapid and toxic intermediates were not detected. The process follows two steps: (i) pollutant adsorption onto AC followed by (ii) adsorbed compounds oxidation. Thus, MW-CWPO with AC as catalyst appears a promising way for a fast and effective process for B, T, X, and N removal in aqueous phase.

  3. Microwave-assisted silica coating and photocatalytic activities of ZnO nanoparticles

    International Nuclear Information System (INIS)

    Siddiquey, Iqbal Ahmed; Furusawa, Takeshi; Sato, Masahide; Suzuki, Noboru

    2008-01-01

    A new and rapid method for silica coating of ZnO nanoparticles by the simple microwave irradiation technique is reported. Silica-coated ZnO nanoparticles were characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), high-resolution transmission electron microscopy (HR-TEM), CHN elemental analysis and zeta potential measurements. The FT-IR spectra and XPS clearly confirmed the silica coating on ZnO nanoparticles. The results of XPS analysis showed that the elements in the coating at the surface of the ZnO nanoparticles were Zn, O and Si. HR-TEM micrographs revealed a continuous and uniform dense silica coating layer of about 3 nm in thickness on the surface of ZnO nanoparticles. In addition, the silica coating on the ZnO nanoparticles was confirmed by the agreement in the zeta potential of the silica-coated ZnO nanoparticles with that of SiO 2 . The results of the photocatalytic degradation of methylene blue (MB) in aqueous solution showed that silica coating effectively reduced the photocatalytic activity of ZnO nanoparticles. Silica-coated ZnO nanoparticles showed excellent UV shielding ability and visible light transparency

  4. Rapid determination of gross alpha and beta activity in seafood utilizing microwave digestion and liquid scintillation counting

    International Nuclear Information System (INIS)

    Daniel Sas; Jiri Janda; Alena Tokarova

    2015-01-01

    This paper describes a method for rapid determination of gross alpha and beta activity in seafood using liquid scintillation counting and microwave digestion for fast sample decomposition. The general group of seafood was divided into two groups based on its structure, whether it has shell or not. The selected group of radionuclides was chosen with respect to military significance, radiotoxicity, and possibility of potential misuse. 90 Sr and 239 Pu were selected as model radionuclides. (author)

  5. Effect of prenatal and postnatal microwave exposures on relative activity of SDH of brain and liver in newborn mice

    International Nuclear Information System (INIS)

    Jiang Huai; Yao Gengdong; Zhou Shiyun

    1987-01-01

    Pregnant mice were irradiated with 3 GHz pulse microwave at 8 mW/cm 2 (SAR 3.0-3.5 mW/g) and part of their offspring were irradiated at 1 mW/cm 2 . The effects on the mitochondria marker enzyme SDH of brain and liver in the newborn mice were observed. SDH was quanlitatively determined by microspectrophotometry. The results show that a decrease in the relative activity of SDH in brain was induced by either prenatal or postnatal microwave exposure (p < 0.01). The greatest decrease in the relative activity of SDH occurred in the offspring exposed both prenatally and postnatally. The similar but less changes in the activity of SDH occurred in liver of these mice. The results indicate that the brain SDH is a sensitive index to observe the subtle metabolic alterations which can not be detected using conventional morphologic teratologic procedures. It is suggested that pregnant women should be protected from high power density microwave exposure

  6. Integration of active devices on smart polymers for neural interfaces

    Science.gov (United States)

    Avendano-Bolivar, Adrian Emmanuel

    The increasing ability to ever more precisely identify and measure neural interactions and other phenomena in the central and peripheral nervous systems is revolutionizing our understanding of the human body and brain. To facilitate further understanding, more sophisticated neural devices, perhaps using microelectronics processing, must be fabricated. Materials often used in these neural interfaces, while compatible with these fabrication processes, are not optimized for long-term use in the body and are often orders of magnitude stiffer than the tissue with which they interact. Using the smart polymer substrates described in this work, suitability for processing as well as chronic implantation is demonstrated. We explore how to integrate reliable circuitry onto these flexible, biocompatible substrates that can withstand the aggressive environment of the body. To increase the capabilities of these devices beyond individual channel sensing and stimulation, active electronics must also be included onto our systems. In order to add this functionality to these substrates and explore the limits of these devices, we developed a process to fabricate single organic thin film transistors with mobilities up to 0.4 cm2/Vs and threshold voltages close to 0V. A process for fabricating organic light emitting diodes on flexible substrates is also addressed. We have set a foundation and demonstrated initial feasibility for integrating multiple transistors onto thin-film flexible devices to create new applications, such as matrix addressable functionalized electrodes and organic light emitting diodes. A brief description on how to integrate waveguides for their use in optogenetics is addressed. We have built understanding about device constraints on mechanical, electrical and in vivo reliability and how various conditions affect the electronics' lifetime. We use a bi-layer gate dielectric using an inorganic material such as HfO 2 combined with organic Parylene-c. A study of

  7. Experimental study on removals of SO2 and NO(x) using adsorption of activated carbon/microwave desorption.

    Science.gov (United States)

    Ma, Shuang-Chen; Yao, Juan-Juan; Gao, Li; Ma, Xiao-Ying; Zhao, Yi

    2012-09-01

    Experimental studies on desulfurization and denitrification were carried out using activated carbon irradiated by microwave. The influences of the concentrations of nitric oxide (NO) and sulfur dioxide (SO2), the flue gas coexisting compositions, on adsorption properties of activated carbon and efficiencies of desulfurization and denitrification were investigated. The results show that adsorption capacity and removal efficiency of NO decrease with the increasing of SO2 concentrations in flue gas; adsorption capacity of NO increases slightly first and drops to 12.79 mg/g, and desulfurization efficiency descends with the increasing SO2 concentrations. Adsorption capacity of SO2 declines with the increasing of O2 content in flue gas, but adsorption capacity of NO increases, and removal efficiencies of NO and SO2 could be larger than 99%. Adsorption capacity of NO declines with the increase of moisture in the flue gas, but adsorption capacity of SO2 increases and removal efficiencies of NO and SO2 would be relatively stable. Adsorption capacities of both NO and SO2 decrease with the increasing of CO2 content; efficiencies of desulfurization and denitrification augment at the beginning stage, then start to fall when CO2 content exceeds 12.4%. The mechanisms of this process are also discussed. The prominent SO2 and NOx treatment techniques in power plants are wet flue gas desulfurization (FGD) and the catalytic decomposition method like selective catalytic reduction (SCR) or nonselective catalytic reduction (NSCR). However, these processes would have some difficulties in commercial application due to their high investment, requirement of expensive catalysts and large-scale equipment, and so on. A simple SO2 and NOx reduction utilizing decomposition by microwave energy method can be used. The pollutants control of flue gas in the power plants by the method of microwave-induced decomposition using adsorption of activated carbon/microwave desorption can meet the

  8. Improving the biogas production performance of municipal waste activated sludge via disperser induced microwave disintegration.

    Science.gov (United States)

    Kavitha, S; Rajesh Banu, J; Vinoth Kumar, J; Rajkumar, M

    2016-10-01

    In this study, the influence of disperser induced microwave pretreatment was investigated to analyze the proficiency of floc disruption on subsequent disintegration and biodegradability process. Initially, the flocs in the sludge was disrupted through disperser at a specific energy input of 25.3kJ/kgTS. The upshot of the microwave disintegration presents that the solids reduction and solubilization of floc disrupted (disperser induced microwave pretreated) sludge was found to be 17.33% and 22% relatively greater than that achieved in microwave pretreated (9.3% and 16%) sludge alone. The biodegradability analysis, affords an evaluation of parameter confidence and correlation determination. The eventual biodegradability of microwave pretreated, and floc disrupted sludges were computed to be 0.15(gCOD/gCOD) and 0.28(gCOD/gCOD), respectively. An economic assessment of this study offers a positive net profit of about 104.8USD/ton of sludge in floc disrupted sample. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Scavenging remazol brilliant blue R dye using microwave-assisted activated carbon from acacia sawdust: Equilibrium and kinetics studies

    Science.gov (United States)

    Yusop, M. F. M.; Aziz, H. A.; Ahmad, M. A.

    2017-10-01

    This work explores the feasibility of microwave-assisted acacia wood based activated carbon (AWAC) for remazol brilliant blue R (RBBR) dye removal from synthetic wastewater. Acacia wood (AW) was impregnated with potassium hydroxide (KOH) and heated using microwave, resulting tremendously high fixed carbon content, surface area, total pore volume and adsorption capacity of 81.14%, 1045.56m2/g, 0.535cm3/g and 263.16mg/g respectively. Batch study conducted divulged an increasing trend in RBBR uptake when initial RBBR concentration and contact time were increased. pH study revealed that RBBR adsorption was best at acidic condition. Langmuir isotherm model fitted well the adsorption equilibrium data while the adsorption kinetic was found to follow the pseudo-second-order kinetic model.

  10. Microwave-induced activation of additional active edge sites on the MoS2 surface for enhanced Hg0 capture

    Science.gov (United States)

    Zhao, Haitao; Mu, Xueliang; Yang, Gang; Zheng, Chengheng; Sun, Chenggong; Gao, Xiang; Wu, Tao

    2017-10-01

    In recent years, significant effort has been made in the development of novel materials for the removal of mercury from coal-derived flue gas. In this research, microwave irradiation was adopted to induce the creation of additional active sites on the MoS2 surface. The results showed that Hg0 capture efficiency of the adsorbent containing MoS2 nanosheets being microwave treated was as high as 97%, while the sample prepared via conventional method only showed an efficiency of 94% in its first 180 min testing. After the adsorbent was treated by microwave irradiation for 3 more times, its mercury removal efficiency was still noticeably higher than that of the sample prepared via conventional method. Characterization of surface structure of the MoS2 containing material together with DFT study further revealed that the (001) basal planes of MoS2 crystal structure were cracked into (100) edge planes (with an angle of approximately 75°) under microwave treatment, which subsequently resulted in the formation of additional active edge sites on the MoS2 surface and led to the improved performance on Hg0 capture.

  11. Utilization of oil palm biodiesel solid residue as renewable sources for preparation of granular activated carbon by microwave induced KOH activation.

    Science.gov (United States)

    Foo, K Y; Hameed, B H

    2013-02-01

    In this work, preparation of granular activated carbon from oil palm biodiesel solid residue, oil palm shell (PSAC) by microwave assisted KOH activation has been attempted. The physical and chemical properties of PSAC were characterized using scanning electron microscopy, volumetric adsorption analyzer and elemental analysis. The adsorption behavior was examined by performing batch adsorption experiments using methylene blue as dye model compound. Equilibrium data were simulated using the Langmuir, Freundlich and Temkin isotherm models. Kinetic modeling was fitted to the pseudo-first-order, pseudo-second-order and Elovich kinetic models, while the adsorption mechanism was determined using the intraparticle diffusion and Boyd equations. The result was satisfactory fitted to the Langmuir isotherm model with a monolayer adsorption capacity of 343.94mg/g at 30°C. The findings support the potential of oil palm shell for preparation of high surface area activated carbon by microwave assisted KOH activation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. THESEUS: A wavelength division multiplexed/microwave subcarrier multiplexed optical network, its ATM switch applications and device requirements

    Science.gov (United States)

    Xin, Wei

    1997-10-01

    A Terabit Hybrid Electro-optical /underline[Se]lf- routing Ultrafast Switch (THESEUS) has been proposed. It is a self-routing wavelength division multiplexed (WDM) / microwave subcarrier multiplexed (SCM) asynchronous transfer mode (ATM) switch for the multirate ATM networks. It has potential to be extended to a large ATM switch as 1000 x 1000 without internal blocking. Among the advantages of the hybrid implementation are flexibility in service upgrade, relaxed tolerances on optical filtering, protocol simplification and less processing overhead. For a small ATM switch, the subcarrier can be used as output buffers to solve output contention. A mathematical analysis was conducted to evaluate different buffer configurations. A testbed has been successfully constructed. Multirate binary data streams have been switched through the testbed and error free reception ([<]10-9 bit error rate) has been achieved. A simple, intuitive theoretical model has been developed to describe the heterodyne optical beat interference. A new concept of interference time and interference length has been introduced. An experimental confirmation has been conducted. The experimental results match the model very well. It shows that a large portion of optical bandwidth is wasted due to the beat interference. Based on the model, several improvement approaches have been proposed. The photo-generated carrier lifetime of silicon germanium has been measured using time-resolved reflectivity measurement. Via oxygen ion implantation, the carrier lifetime has been reduced to as short as 1 ps, corresponding to 1 THz of photodetector bandwidth. It has also been shown that copper dopants act as recombination centers in the silicon germanium.

  13. Secure Communications with Mobile Devices During In-Field Activities

    International Nuclear Information System (INIS)

    Partee, M.S.; Moser, F.

    2015-01-01

    One of the classic problems in information security is how to exchange confidential information securely in uncontrolled environments. There have been innumerable academic and commercial hours spent resolving this question. In traditional practice, securing communications meant investing in satellites, specialized hardware, rigorous security engineering and testing, and expending a lot of resources. For this reason, smaller organizations have often been unable to secure communications. The widespread adoption of mobile communications and the modern mobile device has brought about unprecedented abilities to stay connected with colleagues during work activities. As connectedness has increased, so have the opportunities for information compromise. The enormous mobile landscape, with competing ecosystems, large research and product development budgets, proliferating devices, and rapidly-shifting technical foundations prove to be a tremendous source of both opportunity and risk. With the reality of shrinking budgets and increasing threats, many organizations, commercial enterprises, and product vendors are looking for new ways to utilize existing resources for secure communications and mobile work capabilities. Keeping communications private and secure using the infrastructure of the world's telecommunications network and standard computing and mobile devices is the challenge. This paper will examine some methods for communicating securely using consumer mobile products and evaluate the risk such tools can present to an organization in the context of inspection work in the field. (author)

  14. Active fiber optic technologies used as tamper-indicating devices

    International Nuclear Information System (INIS)

    Horton, P.R.V.; Waddoups, I.G.

    1995-11-01

    The Sandia National Laboratories (SNL) Safeguards and Seals Evaluation Program is evaluating new fiber optic active seal technologies for use at Department of Energy (DOE) facilities. The goal of the program is to investigate active seal technologies that can monitor secured containers storing special nuclear materials (SNM) within DOE vaults. Specifically investigated were active seal technologies that can be used as tamper-indicating devices to monitor secured containers within vaults while personnel remain outside the vault area. Such a system would allow minimal access into vaults while ensuring container content accountability. The purpose of this report is to discuss tamper-indicating devices that were evaluated for possible DOE use. While previous seal evaluations (Phase I and II) considered overall facility applications, this discussion focuses specifically on their use in vault storage situations. The report will highlight general background information, specifications and requirements, and test procedures. Also discussed are the systems available from four manufacturers: Interactive Technologies, Inc., Fiber SenSys, Inc., Inovonics, Inc., and Valve Security Systems

  15. Photoluminescence enhancement of porous silicon particles by microwave-assisted activation

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Bing [Key Laboratory of Forest Genetics and Biotechnology (Ministry of Education of China), Nanjing Forestry University, Nanjing 210037 (China); Advanced Analysis and Testing Center, Nanjing Forestry University, Nanjing 210037 (China); Zhang, Wenyi; Dong, Chen; Shi, Jisen [Key Laboratory of Forest Genetics and Biotechnology (Ministry of Education of China), Nanjing Forestry University, Nanjing 210037 (China); Bao, Weiyi [Advanced Analysis and Testing Center, Nanjing Forestry University, Nanjing 210037 (China); Zhang, Junfeng [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093 (China)

    2012-11-15

    Photoluminescence (PL) of porous silicon (PSi) particles can be significantly enhanced in some organic solvents (i.e., ethanol or dimethyl sulfoxide) under microwave irradiation. Fourier transform infrared spectra, dynamic-light-scattering measurements, and scanning electron microscopy had been adopted to explore the mechanism of PL enhancement of PSi particles under microwave irradiation, which is attributed to the formation of higher porosity and the growth of silicon oxide by microwave-assisted wet etching. Compared with that fabricated by ultrasonication, smaller luminescent PSi nanoparticles (average size {proportional_to}60 nm) with stronger orange-red fluorescence (PL quantum yield {proportional_to}14.8%) and higher dispersibility can be large-scale prepared for cellular imaging and drug delivery in biomedical applications. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. The Rubble Rescue Radar (RRR): A low power hand-held microwave device for the detection of trapped human personnel

    International Nuclear Information System (INIS)

    Haddad, W.S.

    1997-01-01

    Each year, innocent human lives are lost in collapsed structures as a result of both natural and man-made disasters. We have developed a prototype device, called the Rubble Rescue Radar (RRR) as a aid to workers trying to locate trapped victims in urban search and rescue operations. The RRR is a motion sensor incorporating Micropower Impulse Radar and is capable of detecting human breathing motions through reinforced concrete. It is lightweight, and designed to be handled by a single operator for local searches in areas where trapped victims are expected. Tests of the first prototype device were conducted on site at LLNL using a mock rubble pile consisting of a reinforced concrete pipe with two concrete floor slabs placed against one side, and random concrete and asphalt debris piled against the other. This arrangement provides safe and easy access for instruments and/or human subjects. Breathing signals of a human subject were recorded with the RRR through one floor slab plus the wall of the pipe, two slabs plus the wall of the pipe, and the random rubble plus the wall of the pipe. Breathing and heart beat signals were also recorded of a seated human subject at a distance of 1 meter with no obstructions. Results and photographs of the experimental work are presented, and a design concept for the next generation device is described

  17. Monolithic microwave integrated circuit with integral array antenna

    International Nuclear Information System (INIS)

    Stockton, R.J.; Munson, R.E.

    1984-01-01

    A monolithic microwave integrated circuit including an integral array antenna. The system includes radiating elements, feed network, phasing network, active and/or passive semiconductor devices, digital logic interface circuits and a microcomputer controller simultaneously incorporated on a single substrate by means of a controlled fabrication process sequence

  18. Microwave assisted centrifuge and related methods

    Science.gov (United States)

    Meikrantz, David H [Idaho Falls, ID

    2010-08-17

    Centrifuge samples may be exposed to microwave energy to heat the samples during centrifugation and to promote separation of the different components or constituents of the samples using a centrifuge device configured for generating microwave energy and directing the microwave energy at a sample located in the centrifuge.

  19. Microwave Irradiation

    Indian Academy of Sciences (India)

    Way to Eco-friendly, Green Chemistry. Rashmi ... The rapid heating of food in the kitchen using microwave ovens ... analysis; application to waste treatment; polymer technology; ... of microwave heating in organic synthesis since the first contri-.

  20. Enhanced decomposition of dimethyl phthalate via molecular oxygen activated by Fe-Fe{sub 2}O{sub 3}/AC under microwave irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yiling [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China); Ai, Zhihui, E-mail: jennifer.ai@mail.ccnu.edu.cn [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China); Zhang, Lizhi [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Microwave irradiation induces the electrons transferring from AC to Fe-Fe{sub 2}O{sub 3} and reacts with molecular oxygen. Black-Right-Pointing-Pointer Microwave heating accelerates the electron transferring from AC to Fe-Fe{sub 2}O{sub 3} to generate reactive oxygen species. Black-Right-Pointing-Pointer This environmental remediation method is feasible for aqueous organic pollutants treatment. - Abstract: In this study, we demonstrate that the decomposition of dimethyl phthalate under microwave irradiation could be greatly enhanced over Fe-Fe{sub 2}O{sub 3} nanowires supported on activated carbon (Fe-Fe{sub 2}O{sub 3}/AC). The great enhanced decomposition of dimethyl phthalate could be attributed to a unique microwave induced molecular oxygen activation process. Upon microwave irradiation, electrons could be transferred from activated carbon to zero-valent iron, and then react with molecular oxygen to form O{sub 2}{center_dot}{sup -} and {center_dot}OH radicals for the decomposition of dimethyl phthalate. The deactivation and the regeneration of Fe-Fe{sub 2}O{sub 3}/AC catalyst were systematically studied. We also found that microwave heating could accelerate the electron transferring from AC to Fe-Fe{sub 2}O{sub 3} to generate more reactive oxygen species for the decomposition of DMP than conventional oil bath heating. This novel molecular oxygen activation approach may find applications for wastewater treatment and drinking water purification.

  1. Microwave-Hydrothermal Synthesis of SnO2-CNTs Hybrid Nanocomposites with Visible Light Photocatalytic Activity.

    Science.gov (United States)

    Wu, Shuisheng; Dai, Weili

    2017-03-03

    SnO2 nanoparticles coated on carbon nanotubes (CNTs) were prepared via a simple microwave-hydrothermal route. The as-obtained SnO2-CNTs composites were characterized using X-ray powder diffraction, Raman spectroscopy, and transmission electron microscopy. The photocatalytic activity of as-prepared SnO2-CNTs for degradation of Rhodamine B under visible light irradiation was investigated. The results show that SnO2-CNTs nanocomposites have a higher photocatalytic activity than pure SnO2 due to the rapid transferring of electrons and the effective separation of holes and electrons on SnO2-CNTs.

  2. Treatment of Reactive Black 5 by combined electrocoagulation-granular activated carbon adsorption-microwave regeneration process

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Shih-Hsien, E-mail: shchang@csmu.edu.tw [Department of Public Health, Chung-Shan Medical University, 110 Chen-Kuo N. Road, Taichung 402, Taiwan (China); Wang, Kai-Sung; Liang, Hsiu-Hao; Chen, Hsueh-Yu; Li, Heng-Ching; Peng, Tzu-Huan [Department of Public Health, Chung-Shan Medical University, 110 Chen-Kuo N. Road, Taichung 402, Taiwan (China); Su, Yu-Chun; Chang, Chih-Yuan [Institute of Environmental Engineering, National Chiao-Tung University, Hsinchu, 300, Taiwan (China)

    2010-03-15

    Treatment of an azo dye, Reactive Black 5 (RB5) by combined electrocoagulation-activated carbon adsorption-microwave regeneration process was evaluated. The toxicity was also monitored by the Vibrio fischeri light inhibition test. GAC of 100 g L{sup -1} sorbed 82% of RB5 (100 mg L{sup -1}) within 4 h. RB5-loaded GAC was not effectively regenerated by microwave irradiation (800 W, 30 s). Electrocoagulation showed high decolorization of RB5 within 8 min at pH{sub 0} of 7, current density of 277 A m{sup -2}, and NaCl of 1 g L{sup -1}. However, 61% COD residue remained after treatment and toxicity was high (100% light inhibition). GAC of 20 g L{sup -1} effectively removed COD and toxicity of electrocoagulation-treated solution within 4 h. Microwave irradiation effectively regenerated intermediate-loaded GAC within 30 s at power of 800 W, GAC/water ratio of 20 g L{sup -1}, and pH of 7.8. The adsorption capacity of GAC for COD removal from the electrocoagulation-treated solution did not significantly decrease at the first 7 cycles of adsorption/regeneration. The adsorption capacity of GAC for removal of both A{sub 265} (benzene-related groups) and toxicity slightly decreased after the 6th cycle.

  3. Treatment of Reactive Black 5 by combined electrocoagulation-granular activated carbon adsorption-microwave regeneration process

    International Nuclear Information System (INIS)

    Chang, Shih-Hsien; Wang, Kai-Sung; Liang, Hsiu-Hao; Chen, Hsueh-Yu; Li, Heng-Ching; Peng, Tzu-Huan; Su, Yu-Chun; Chang, Chih-Yuan

    2010-01-01

    Treatment of an azo dye, Reactive Black 5 (RB5) by combined electrocoagulation-activated carbon adsorption-microwave regeneration process was evaluated. The toxicity was also monitored by the Vibrio fischeri light inhibition test. GAC of 100 g L -1 sorbed 82% of RB5 (100 mg L -1 ) within 4 h. RB5-loaded GAC was not effectively regenerated by microwave irradiation (800 W, 30 s). Electrocoagulation showed high decolorization of RB5 within 8 min at pH 0 of 7, current density of 277 A m -2 , and NaCl of 1 g L -1 . However, 61% COD residue remained after treatment and toxicity was high (100% light inhibition). GAC of 20 g L -1 effectively removed COD and toxicity of electrocoagulation-treated solution within 4 h. Microwave irradiation effectively regenerated intermediate-loaded GAC within 30 s at power of 800 W, GAC/water ratio of 20 g L -1 , and pH of 7.8. The adsorption capacity of GAC for COD removal from the electrocoagulation-treated solution did not significantly decrease at the first 7 cycles of adsorption/regeneration. The adsorption capacity of GAC for removal of both A 265 (benzene-related groups) and toxicity slightly decreased after the 6th cycle.

  4. Microwave-Assisted Simultaneous Extraction of Luteolin and Apigenin from Tree Peony Pod and Evaluation of Its Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Hongzheng Wang

    2014-01-01

    Full Text Available An efficient microwave-assisted extraction (MAE technique was employed in simultaneous extraction of luteolin and apigenin from tree peony pod. The MAE procedure was optimized using response surface methodology (RSM and compared with other conventional extraction techniques of macerate extraction (ME and heat reflux extraction (HRE. The optimal conditions of MAE were as follows: employing 70% ethanol volume fraction as solvent, soaking time of 4 h, liquid-solid ratio of 10 (mL/g, microwave irradiation power of 265 W, microwave irradiation time of 9.6 min, and 3 extraction cycles. Under the optimal conditions, 151 μg/g luteolin and 104 μg/g apigenin were extracted from the tree peony pod. Compared with ME and HRE, MAE gave the highest extraction efficiency. The antioxidant activities of the extracts obtained by MAE, ME, and HRE were evaluated using a 2,2-di(4-tert-octylphenyl-1-picrylhydrazyl (DPPH free radical-scavenging assay, a ferric reducing antioxidant power assay (FRAP, and a reducing power assay. Meanwhile, the structural changes of the unprocessed and processed tree peony pod samples were analyzed by scanning electron microscopy.

  5. Inferring Human Activity in Mobile Devices by Computing Multiple Contexts.

    Science.gov (United States)

    Chen, Ruizhi; Chu, Tianxing; Liu, Keqiang; Liu, Jingbin; Chen, Yuwei

    2015-08-28

    This paper introduces a framework for inferring human activities in mobile devices by computing spatial contexts, temporal contexts, spatiotemporal contexts, and user contexts. A spatial context is a significant location that is defined as a geofence, which can be a node associated with a circle, or a polygon; a temporal context contains time-related information that can be e.g., a local time tag, a time difference between geographical locations, or a timespan; a spatiotemporal context is defined as a dwelling length at a particular spatial context; and a user context includes user-related information that can be the user's mobility contexts, environmental contexts, psychological contexts or social contexts. Using the measurements of the built-in sensors and radio signals in mobile devices, we can snapshot a contextual tuple for every second including aforementioned contexts. Giving a contextual tuple, the framework evaluates the posteriori probability of each candidate activity in real-time using a Naïve Bayes classifier. A large dataset containing 710,436 contextual tuples has been recorded for one week from an experiment carried out at Texas A&M University Corpus Christi with three participants. The test results demonstrate that the multi-context solution significantly outperforms the spatial-context-only solution. A classification accuracy of 61.7% is achieved for the spatial-context-only solution, while 88.8% is achieved for the multi-context solution.

  6. Recent Advancements in Microwave Imaging Plasma Diagnostics

    International Nuclear Information System (INIS)

    Park, H.; Chang, C.C.; Deng, B.H.; Domier, C.W.; Donni, A.J.H.; Kawahata, K.; Liang, C.; Liang, X.P.; Lu, H.J.; Luhmann, N.C. Jr.; Mase, A.; Matsuura, H.; Mazzucato, E.; Miura, A.; Mizuno, K.; Munsat, T.; Nagayama, K.; Nagayama, Y.; Pol, M.J. van de; Wang, J.; Xia, Z.G.; Zhang, W-K.

    2002-01-01

    Significant advances in microwave and millimeter wave technology over the past decade have enabled the development of a new generation of imaging diagnostics for current and envisioned magnetic fusion devices. Prominent among these are revolutionary microwave electron cyclotron emission imaging (ECEI), microwave phase imaging interferometers, imaging microwave scattering and microwave imaging reflectometer (MIR) systems for imaging electron temperature and electron density fluctuations (both turbulent and coherent) and profiles (including transport barriers) on toroidal devices such as tokamaks, spherical tori, and stellarators. The diagnostic technology is reviewed, and typical diagnostic systems are analyzed. Representative experimental results obtained with these novel diagnostic systems are also presented

  7. Coherent tools for physics-based simulation and characterization of noise in semiconductor devices oriented to nonlinear microwave circuit CAD

    Science.gov (United States)

    Riah, Zoheir; Sommet, Raphael; Nallatamby, Jean C.; Prigent, Michel; Obregon, Juan

    2004-05-01

    We present in this paper a set of coherent tools for noise characterization and physics-based analysis of noise in semiconductor devices. This noise toolbox relies on a low frequency noise measurement setup with special high current capabilities thanks to an accurate and original calibration. It relies also on a simulation tool based on the drift diffusion equations and the linear perturbation theory, associated with the Green's function technique. This physics-based noise simulator has been implemented successfully in the Scilab environment and is specifically dedicated to HBTs. Some results are given and compared to those existing in the literature.

  8. Selenium analysis by an integrated microwave digestion-needle trap device with hydride sorption on carbon nanotubes and electrothermal atomic absorption spectrometry determination

    Science.gov (United States)

    Maratta Martínez, Ariel; Vázquez, Sandra; Lara, Rodolfo; Martínez, Luis Dante; Pacheco, Pablo

    2018-02-01

    An integrated microwave assisted digestion (MW-AD) - needle trap device (NTD) for selenium determination in grape pomace samples is presented. The NTD was filled with oxidized multiwall carbon nanotubes (oxMWCNTS) where Se hydrides were preconcentrated. Determination was carried out by flow injection-electrothermal atomic absorption spectrometry (FI-ETAAS). The variables affecting the system were established by a multivariate design (Plackett Burman), indicating that the following variables significantly affect the system: sample amount, HNO3 digestion solution concentration, NaBH4 volume and elution volume. A Box-Behnken design was implemented to determine the optimized values of these variables. The system improved Se atomization in the graphite furnace, since only trapped hydrides reached the graphite furnace, and the pyrolysis stage was eliminated according to the aqueous matrix of the eluate. Under optimized conditions the system reached a limit of quantification of 0.11 μg kg- 1, a detection limit of 0.032 μg kg- 1, a relative standard deviation of 4% and a preconcentration factor (PF) of 100, reaching a throughput sample of 5 samples per hour. Sample analysis show Se concentrations between 0.34 ± 0.03 μg kg- 1 to 0.48 ± 0.03 μg kg- 1 in grape pomace. This system provides minimal reagents and sample consumption, eliminates discontinuous stages between samples processing reaching a simpler and faster Se analysis.

  9. Integration of optically active Neodymium ions in Niobium devices (Nd:Nb): quantum memory for hybrid quantum entangled systems

    Science.gov (United States)

    Nayfeh, O. M.; Chao, D.; Djapic, N.; Sims, P.; Liu, B.; Sharma, S.; Lerum, L.; Fahem, M.; Dinh, V.; Zlatanovic, S.; Lynn, B.; Torres, C.; Higa, B.; Moore, J.; Upchurch, A.; Cothern, J.; Tukeman, M.; Barua, R.; Davidson, B.; Ramirez, A. D.; Rees, C. D.; Anant, V.; Kanter, G. S.

    2017-08-01

    Optically active rare-earth Neodymium (Nd) ions are integrated in Niobium (Nb) thin films forming a new quantum memory device (Nd:Nb) targeting long-lived coherence times and multi-functionality enabled by both spin and photon storage properties. Nb is implanted with Nd spanning 10-60 keV energy and 1013-1014 cm-2 dose producing a 1- 3% Nd:Nb concentration as confirmed by energy-dispersive X-ray spectroscopy. Scanning confocal photoluminescence (PL) at 785 nm excitation are made and sharp emission peaks from the 4F3/2 -red shift and increased broadening to a 4.8 nm linewidth. Nd:Nb is photoconductive and responds strongly to applied fields. Furthermore, optically detected magnetic resonance (ODMR) measurements are presented spanning near-infrared telecom band. The modulation of the emission intensity with magnetic field and microwave power by integration of these magnetic Kramer type Nd ions is quantified along with spin echoes under pulsed microwave π-π/2 excitation. A hybrid system architecture is proposed using spin and photon quantum information storage with the nuclear and electron states of the Nd3+ and neighboring Nb atoms that can couple qubit states to hyperfine 7/2 spin states of Nd:Nb and onto NIR optical levels excitable with entangled single photons, thus enabling implementation of computing and networking/internet protocols in a single platform.

  10. 78 FR 7939 - Energy Conservation Program: Test Procedures for Microwave Ovens (Active Mode)

    Science.gov (United States)

    2013-02-04

    ...--Measurement of standby power,'' Edition 2.0 2011-01 (IEC Standard 62301 (Second Edition)) for measuring... cooking mode, plus the sum of the product of the average standby mode and off mode power consumption and... usage habits for microwave ovens.\\5\\ The survey collected data from 2258 households on the typical cycle...

  11. Axisymmetric charge-conservative electromagnetic particle simulation algorithm on unstructured grids: Application to microwave vacuum electronic devices

    Science.gov (United States)

    Na, Dong-Yeop; Omelchenko, Yuri A.; Moon, Haksu; Borges, Ben-Hur V.; Teixeira, Fernando L.

    2017-10-01

    We present a charge-conservative electromagnetic particle-in-cell (EM-PIC) algorithm optimized for the analysis of vacuum electronic devices (VEDs) with cylindrical symmetry (axisymmetry). We exploit the axisymmetry present in the device geometry, fields, and sources to reduce the dimensionality of the problem from 3D to 2D. Further, we employ 'transformation optics' principles to map the original problem in polar coordinates with metric tensor diag (1 ,ρ2 , 1) to an equivalent problem on a Cartesian metric tensor diag (1 , 1 , 1) with an effective (artificial) inhomogeneous medium introduced. The resulting problem in the meridian (ρz) plane is discretized using an unstructured 2D mesh considering TEϕ-polarized fields. Electromagnetic field and source (node-based charges and edge-based currents) variables are expressed as differential forms of various degrees, and discretized using Whitney forms. Using leapfrog time integration, we obtain a mixed E - B finite-element time-domain scheme for the full-discrete Maxwell's equations. We achieve a local and explicit time update for the field equations by employing the sparse approximate inverse (SPAI) algorithm. Interpolating field values to particles' positions for solving Newton-Lorentz equations of motion is also done via Whitney forms. Particles are advanced using the Boris algorithm with relativistic correction. A recently introduced charge-conserving scatter scheme tailored for 2D unstructured grids is used in the scatter step. The algorithm is validated considering cylindrical cavity and space-charge-limited cylindrical diode problems. We use the algorithm to investigate the physical performance of VEDs designed to harness particle bunching effects arising from the coherent (resonance) Cerenkov electron beam interactions within micro-machined slow wave structures.

  12. High-power microwave LDMOS transistors for wireless data transmission technologies (Review)

    International Nuclear Information System (INIS)

    Kuznetsov, E. V.; Shemyakin, A. V.

    2010-01-01

    The fields of the application, structure, fabrication, and packaging technology of high-power microwave LDMOS transistors and the main advantages of these devices were analyzed. Basic physical parameters and some technology factors were matched for optimum device operation. Solid-state microwave electronics has been actively developed for the last 10-15 years. Simultaneously with improvement of old devices, new devices and structures are actively being adopted and developed and new semiconductor materials are being commercialized. Microwave LDMOS technology is in demand in such fields as avionics, civil and military radars, repeaters, base stations of cellular communication systems, television and broadcasting transmitters, and transceivers for high-speed wireless computer networks (promising Wi-Fi and Wi-Max standards).

  13. Microwave-assisted activated carbon from cocoa shell as adsorbent for removal of sodium diclofenac and nimesulide from aqueous effluents

    International Nuclear Information System (INIS)

    Saucier, Caroline; Adebayo, Matthew A.; Lima, Eder C.; Cataluña, Renato; Thue, Pascal S.; Prola, Lizie D.T.; Puchana-Rosero, M.J.; Machado, Fernando M.; Pavan, Flavio A.; Dotto, G.L.

    2015-01-01

    Highlights: • Microwave-assisted cocoa shell activated carbon was prepared and characterized. • The anti-inflammatories, diclofenac and nimesulide, were adsorbed onto MWCS-1.0. • Adsorption maximum values are 63.47 (diclofenac) and 74.81 mg g −1 (nimesulide). • General order kinetic model suitably explained the adsorption process. • MWCS-1.0 was effectively used for treatment of simulated hospital effluents. - Abstract: Microwave-induced chemical activation process was used to prepare an activated carbon from cocoa shell for efficient removal of two anti-inflammatories, sodium diclofenac (DFC) and nimesulide (NM), from aqueous solutions. A paste was obtained from a mixture of cocoa shell and inorganic components; with a ratio of inorganic: organic of 1 (CSC-1.0). The mixture was pyrolyzed in a microwave oven in less than 10 min. The CSC-1.0 was acidified with a 6 mol L −1 HCl under reflux to produce MWCS-1.0. The CSC-1.0 and MWCS-1.0 were characterized using FTIR, SEM, N 2 adsorption/desorption curves, X-ray diffraction, and point of zero charge (pH pzc ). Experimental variables such as initial pH of the adsorbate solutions and contact time were optimized for adsorptive characteristics of MWCS-1.0. The optimum pH for removal of anti-inflammatories ranged between 7.0 and 8.0. The kinetic of adsorption was investigated using general order, pseudo first-order and pseu do-second order kinetic models. The maximum amounts of DCF and NM adsorbed onto MWCS-1.0 at 25 °C are 63.47 and 74.81 mg g −1 , respectively. The adsorbent was tested on two simulated hospital effluents. MWCS-1.0 is capable of efficient removal of DCF and NM from a medium that contains high sugar and salt concentrations

  14. Device for measuring active, reactive and apparent power

    Energy Technology Data Exchange (ETDEWEB)

    Bartosinski, E.; Wieland, J.

    1982-09-30

    The plan consists of a traditional electrodynamic mechanism for measuring power (IM) supplemented by three switches, two rectifiers, resistor, included in parallel, and phaseshifting throttle included in series with the voltage coil of the IM. This makes it possible by selection to perform three types of measurements: active power of alternating current or power of direct current, only the voltage coils and the IM current are engaged; reactive power, the resistor and the throttle are additionally engaged by the aforementioned method; complete (apparent) power--the current and the voltage are supplied directly to the IM coils, but in contrast to the first case, through rectifiers. The influence of the highest harmonic components of voltage and current which are not significant for industrial measurements can be eliminated in necessary cases using filtering devices.

  15. Towards an Active Hearing Protection Device for Musicians =

    Science.gov (United States)

    Bernier, Antoine

    Professional musicians are oftentimes exposed to high levels of sound. Prolonged or severe exposure to high sound levels could lead to permanent hearing loss and compromise their career. The logical solution would be to wear hearing protection devices (HPDs) when appropriate. However, perceptual discomfort associated with wearing HPD can discourage their use by musicians. The perceptual discomfort is caused by two detrimental effects: the occlusion effect and the isolation effect. The occlusion effect is often reported as an augmented, unnatural and annoying perception of one's own voice or instrument mechanically coupled to the head when wearing HPDs. The isolation effect is the unnatural sensation of being isolated from a given sound environment and can be caused by wearing HPDs that do not compensate for psychoacoustical factors and therefore alter the wearer's auditory perception. Both effects are highly unfavorable to the musicians' auditory perception and compromise their capacity to perform to the best of their abilities for their audience. They are among the reasons most often reported by musicians to decide not to wear HPDs. This master's project presents the concept and first prototype of an active HPD for musicians that aims at solving the detrimental effects while protecting the musician's hearing. A solution for the occlusion effect is presented in the form of an earplug complemented with in-ear active noise control. Practical design issues and required trade-off are analyzed through a literature review and the implementation and characterization of an active occlusion effect reduction system, allowing reduction of the occlusion effect between 8.5 and 12 dB at 250 Hz. A solution for the isolation effect is presented in the form of an earplug complemented with digital signal processing capabilities. Factors that may cause the isolation effect are identified through a literature review and corresponding algorithms that aim at re-establishing the

  16. Impacts of microwave pretreatments on the semi-continuous anaerobic digestion of dairy waste activated sludge

    International Nuclear Information System (INIS)

    Uma Rani, R.; Adish Kumar, S.; Kaliappan, S.; Yeom, IckTae; Rajesh Banu, J.

    2013-01-01

    Highlights: ► Microwave pretreatment of dairy WAS was studied. ► MW pretreatment at 70% intensity for 12 min, COD solubilization was 18.6%. ► Biogas production and SS reduction was 35% and 14% higher than control. ► In digester at 15 days SRT with medium OLR, SS and VS reduction was 67% and 64%. ► Biogas and methane production was 57% and 49% higher than control, in digesters. - Abstract: Microwave (MW) irradiation is one of the new and possible methods used for pretreating the sludge. Following its use in different fields, this MW irradiation method has proved to be more appropriate in the field of environmental research. In this paper, we focused on the effects of MW irradiation at different intensities on solubilization, biodegradation and anaerobic digestion of sludge from the dairy sludge. The changes in the soluble fractions of the organic matter, the biogas yield, the methane content in the biogas were used as control parameters for evaluating the efficiency of the MW pretreatment. Additionally, the energetic efficiency was also examined. In terms of an energetic aspect, the most economical pretreatment of sludge was at 70% intensity for 12 min irradiation time. At this, COD solubilization, SS reduction and biogas production were found to be 18.6%, 14% and 35% higher than the control, respectively. Not only the increase in biogas production was investigated, excluding protein and carbohydrate hydrolysis was also performed successfully by this microwave pretreatment even at low irradiation energy input. Also, experiments were carried out in semi continuous anaerobic digesters, with 3.5 L working volume. Combining microwave pretreatment with anaerobic digestion led to 67%, 64% and 57% of SS reduction, VS reduction and biogas production higher than the control, respectively

  17. Enhanced photocatalytic activity of microwave treated TiO2 pillared montmorillonite

    International Nuclear Information System (INIS)

    Sun Shenmei; Jiang Yinshan; Yu Lixin; Li Fangfei; Yang Zhengwen; Hou Tianyi; Hu Daqiang; Xia Maosheng

    2006-01-01

    TiO 2 pillared montmorillonite synthesized by microwave irradiation, exhibited good photocatalytic degradation performance of methyl orange, whose pseudo first order reaction rate constant was nearly four times than that of conventional method, because of its enhanced crystalline, preferred anatase phase and improved porosity performance, which were analysed by X-ray diffraction (XRD), far Fourier transform infrared ray spectroscopy (FTIR) and nitrogen adsorption isotherms

  18. Removal of Hexavalent Chromium by Adsorption on Microwave Assisted Activated Carbon Prepared from Stems of Leucas Aspera

    Science.gov (United States)

    Shanmugalingam, A.; Murugesan, A.

    2018-05-01

    This study reports adsorption of Cr(VI) ions from aqueous solution using activated carbon that was prepared from stems of Leucas aspera. Eight hundred and fifty watts power of microwave radiation, 12 min of radiation time, 60% of ZnCl2 solution and 24 h of impregnation time are the optimal parameters to prepare efficient carbon effective activated carbon. It was designated as MWLAC (Microwave assisted Zinc chloride activated Leucas aspera carbon). Various adsorption characteristics such as dose of the adsorbent, agitation time, initial Cr(VI) ion concentration, pH of the solution and temperature on adsorption were studied for removal of Cr(VI) ions from aqueous solution by batch mode. Also the equilibrium adsorption was analyzed by the Langmuir, Freundlich, Tempkin and D-R isotherm models. The order of best describing isotherms was given based on R2 value. The pseudo-second-order kinetic model best fitted with the Cr(VI) adsorption data. Thermodynamic parameters were also determined and results suggest that the adsorption process is a spontaneous, endothermic and proceeded with increased randomness.

  19. Changes on antioxidant activity of microwave-treated protein hydrolysates after simulated gastrointestinal digestion: Purification and identification.

    Science.gov (United States)

    Ketnawa, Sunantha; Wickramathilaka, Malithi; Liceaga, Andrea M

    2018-07-15

    Two samples of trout frame protein hydrolysates were prepared by Microwave Pretreatment followed by Conventional Enzymatic hydrolysis (MPCE) and Non-Pretreated followed by Microwave-assisted Enzymatic hydrolysis (NPME), respectively, were subjected to simulated gastrointestinal digestion. Changes on degree of hydrolysis, antioxidant activity, molecular weight, and amino acid composition between undigested and after gastrointestinal digestion of peptides were investigated. Comparing to undigested peptides, a breakdown of MPCE and NPME into smaller molecules was observed. Degree of hydrolysis, ABTS + radical scavenging activity and reducing power increased (P digestion. A purified peptide from GI-MPCE had two possible sequences, NGRLGYSEGVM or GNRLGYSWDD (1182.65 Da). Whereas GI-NPME had two peptides IRGPEEHMHR or RVAPEEHMHR (1261.77 Da) and SAGVPRHK or SARPRHK (962.63 Da). These results indicate that digested hydrolysates can be a rich source of antioxidants. Isolated peptides extracted from trout frame by-products could be new food ingredients used as natural antioxidants. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. An Assessment of the Capabilities of the ERS Satellites' Active Microwave Instruments for Monitoring Soil Moisture Change

    Directory of Open Access Journals (Sweden)

    K. Blyth

    1997-01-01

    Full Text Available The launch of the European Remote sensing Satellite (ERS-1 in July 1991 represented an important turning point in the development of Earth observation as it was the first of a series of satellites which would carry high resolution active microwave (radar sensors which could operate through the thickest cloudeover and provide continuity of data for at least a decade. This was of particular relevance to hydrological applications, such as soil moisture monitoring, which generally require frequent satellite observations to monitor changes in state. ERS-1 and its successor ERS-2 carry the active microwave instrument (AMI which operates in 3 modes (synthetic aperture radar, wind scatterometer and wave seatterometer together with the radar altimeter which may all be useful for the observation of soil moisture. This paper assesses the utility of these sensors through a comprehensive review of work in this field. Two approaches to soil moisture retrieval are identified: 1 inversion modelling, where the physical effects of vegetation and soil roughness on radar backscatter are quantified through the use of multi-frequency and/or multi-polarization sensors and 2 change detection where these effects are normalized through frequent satellite observation, the residual effects being attributed to short-term changes in soil moisture. Both approaches will be better supported by the future European Envisat-l satellite which will provide both multi-polarization SAR and low resolution products which should facilitate more frequent temporal observation.

  1. Enhanced catalytic activity without the use of an external light source using microwave-synthesized CuO nanopetals

    Directory of Open Access Journals (Sweden)

    Govinda Lakhotiya

    2017-05-01

    Full Text Available We report enhanced catalytic activity of CuO nanopetals synthesized by microwave-assisted wet chemical synthesis. The catalytic reaction of CuO nanopetals and H2O2 was studied with the application of external light source and also under dark conditions for the degradation of the hazardous dye methylene blue. The CuO nanopetals showed significant catalytic activity for the fast degradation of methylene blue and rhodamine B (RhB under dark conditions, without the application of an external light source. This increased catalytic activity was attributed to the co-operative role of H2O2 and the large specific surface area (≈40 m2·g−1 of the nanopetals. We propose a detail mechanism for this fast degradation. A separate study of the effect of different H2O2 concentrations for the degradation of methylene blue under dark conditions is also illustrated.

  2. Microwave undulator

    International Nuclear Information System (INIS)

    Batchelor, K.

    1986-03-01

    The theory of a microwave undulator utilizing a plane rectangular waveguide operating in the TE/sub 10n/ mode and other higher order modes is presented. Based on this, a possible undulator configuration is analyzed, leading to the conclusion that the microwave undulator represents a viable option for undulator wavelength down to about 1 cm where peak voltage and available microwave power considerations limit effectiveness. 4 refs., 4 figs

  3. Microwave Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Makes ultra-high-resolution field measurements. The Microwave Microscope (MWM) has been used in support of several NRL experimental programs involving sea...

  4. Active pixel as dosimetric device for interventional radiology

    International Nuclear Information System (INIS)

    Servoli, L.; Baldaccini, F.; Biasini, M.; Checcucci, B.; Chiocchini, S.; Cicioni, R.; Conti, E.; Di Lorenzo, R.; Dipilato, A.C.; Esposito, A.; Fanó, L.; Paolucci, M.; Passeri, D.; Pentiricci, A.

    2013-01-01

    Interventional Radiology (IR) is a subspecialty of radiology comprehensive of all minimally invasive diagnostic and therapeutic procedures performed using radiological devices to obtain image guidance. The interventional procedures are potentially harmful for interventional radiologists and medical staff due to the X-ray diffusion by the patient's body. The characteristic energy range of the diffused photons spans few tens of keV. In this work we will present a proposal for a new X-ray sensing element in the energy range of interest for IR procedures. The sensing element will then be assembled in a dosimeter prototype, capable of real-time measurement, packaged in a small form-factor, with wireless communication and no external power supply to be used for individual operators dosimetry for IR procedures. For the sensor, which is the heart of the system, we considered three different Active Pixel Sensors (APS). They have shown a good capability as single X-ray photon detectors, up to several tens keV photon energy. Two dosimetric quantities have been considered, the number of detected photons and the measured energy deposition. Both observables have a linear dependence with the dose, as measured by commercial dosimeters. The uncertainties in the measurement are dominated by statistic and can be pushed at ∼5% for all the sensors under test

  5. High power microwaves

    CERN Document Server

    Benford, James; Schamiloglu, Edl

    2016-01-01

    Following in the footsteps of its popular predecessors, High Power Microwaves, Third Edition continues to provide a wide-angle, integrated view of the field of high power microwaves (HPMs). This third edition includes significant updates in every chapter as well as a new chapter on beamless systems that covers nonlinear transmission lines. Written by an experimentalist, a theorist, and an applied theorist, respectively, the book offers complementary perspectives on different source types. The authors address: * How HPM relates historically and technically to the conventional microwave field * The possible applications for HPM and the key criteria that HPM devices have to meet in order to be applied * How high power sources work, including their performance capabilities and limitations * The broad fundamental issues to be addressed in the future for a wide variety of source types The book is accessible to several audiences. Researchers currently in the field can widen their understanding of HPM. Present or pot...

  6. Diagnostic for two-mode variable valve activation device

    Science.gov (United States)

    Fedewa, Andrew M

    2014-01-07

    A method is provided for diagnosing a multi-mode valve train device which selectively provides high lift and low lift to a combustion valve of an internal combustion engine having a camshaft phaser actuated by an electric motor. The method includes applying a variable electric current to the electric motor to achieve a desired camshaft phaser operational mode and commanding the multi-mode valve train device to a desired valve train device operational mode selected from a high lift mode and a low lift mode. The method also includes monitoring the variable electric current and calculating a first characteristic of the parameter. The method also includes comparing the calculated first characteristic against a predetermined value of the first characteristic measured when the multi-mode valve train device is known to be in the desired valve train device operational mode.

  7. Removal of Pb(II) from water by the activated carbon modified by nitric acid under microwave heating.

    Science.gov (United States)

    Yao, Shuheng; Zhang, Jiajun; Shen, Dekui; Xiao, Rui; Gu, Sai; Zhao, Ming; Liang, Junyu

    2016-02-01

    The rice husk based activated carbon (RH-AC) was treated by nitric acid under microwave heating, in order to improve its capability for the removal of heavy metal ions from water. The optimal conditions for the modification of RH-AC (M-RH-AC) were determined by means of orthogonal array experimental design, giving those as the concentration of nitric acid of 8mol/L, modification time of 15min, modification temperature of 130°C and microwave power of 800W. The characteristics of the M-RH-AC and RH-AC were examined by BET, XRD, Raman spectrum, pH titration, zeta potential, Boehm titration and FTIR analysis. The M-RH-AC has lower pore surface area, smaller crystallite, lower pHIEP and more oxygen-containing functional groups than the RH-AC. Removal capacity of Pb(II) ions by the M-RH-AC and RH-AC from water solution was estimated concerning the influence of contact time, pH value, and initial concentration. The equilibrium time of Pb(II) removal was found to be around 90min after modification process. Two kinetic models are adopted to describe the possible Pb(II) adsorption mechanism, finding that the adsorption rate of Pb(II) ions by the M-RH-AC is larger than that of RH-AC. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Microwave Ablation: Comparison of Simultaneous and Sequential Activation of Multiple Antennas in Liver Model Systems.

    Science.gov (United States)

    Harari, Colin M; Magagna, Michelle; Bedoya, Mariajose; Lee, Fred T; Lubner, Meghan G; Hinshaw, J Louis; Ziemlewicz, Timothy; Brace, Christopher L

    2016-01-01

    To compare microwave ablation zones created by using sequential or simultaneous power delivery in ex vivo and in vivo liver tissue. All procedures were approved by the institutional animal care and use committee. Microwave ablations were performed in both ex vivo and in vivo liver models with a 2.45-GHz system capable of powering up to three antennas simultaneously. Two- and three-antenna arrays were evaluated in each model. Sequential and simultaneous ablations were created by delivering power (50 W ex vivo, 65 W in vivo) for 5 minutes per antenna (10 and 15 minutes total ablation time for sequential ablations, 5 minutes for simultaneous ablations). Thirty-two ablations were performed in ex vivo bovine livers (eight per group) and 28 in the livers of eight swine in vivo (seven per group). Ablation zone size and circularity metrics were determined from ablations excised postmortem. Mixed effects modeling was used to evaluate the influence of power delivery, number of antennas, and tissue type. On average, ablations created by using the simultaneous power delivery technique were larger than those with the sequential technique (P Simultaneous ablations were also more circular than sequential ablations (P = .0001). Larger and more circular ablations were achieved with three antennas compared with two antennas (P simultaneous power delivery creates larger, more confluent ablations with greater temperatures than those created with sequential power delivery. © RSNA, 2015.

  9. Use of active and passive microwave remote sensing for soil moisture estimation through corn

    International Nuclear Information System (INIS)

    O'Neill, P.E.; Chauhan, N.S.; Jackson, T.J.

    1996-01-01

    Over the past several years NASA, USDA, and Princeton University have collaborated to conduct hydrology field experiments in instrumented research watersheds in Pennsylvania and Oklahoma with a goal of characterizing the spatial and temporal variability of soil moisture using microwave sensors. As part of these experiments, L-band radar data from both truck and aircraft sensors were used to validate the performance of a vegetation scattering model in which discrete scatter random media techniques were employed to calculate vegetation transmissivity and scattering. These parameters were then used in a soil moisture prediction algorithm based on a radiative transfer approach utilizing aircraft passive microwave data from the L-band PBMR and ESTAR radiometers. Soil moisture was predicted in both experiments for several large corn fields which represented the densest vegetation canopies of all the test fields. Over the 20 per cent change in soil moisture encountered in the experiments, the match of predicted to measured soil moisture was excellent, with an average absolute error of about 0 · 02 cm 3 cm −3 . (author)

  10. Active and Passive Microwave Determination of the Circulation and Characteristics of Weddell and Ross Sea Ice

    Science.gov (United States)

    Drinkwater, Mark R.; Liu, Xiang

    2000-01-01

    A combination of satellite microwave data sets are used in conjunction with ECMWF (Medium Range Weather Forecasts) and NCEP (National Center for Environment Prediction) meteorological analysis fields to investigate seasonal variability in the circulation and sea-ice dynamics of the Weddell and Ross Seas. Results of sea-ice tracking using SSM/I (Special Sensor Microwave Imager), Scatterometer and SAR images are combined with in-situ data derived from Argos buoys and GPS drifters to validate observed drift patterns. Seasonal 3-month climatologies of ice motion and drift speed variance illustrate the response of the sea-ice system to seasonal forcing. A melt-detection algorithm is used to track the onset of seasonal melt, and to determine the extent and duration of atmospherically-led surface melting during austral summer. Results show that wind-driven drift regulates the seasonal distribution and characteristics of sea-ice and the intensity of the cyclonic Gyre circulation in these two regions.

  11. A comparative study on the effect of conventional thermal pasteurisation, microwave and ultrasound treatments on the antioxidant activity of five fruit juices.

    Science.gov (United States)

    Saikia, Sangeeta; Mahnot, Nikhil Kumar; Mahanta, Charu Lata

    2016-06-01

    A comparative study on the effect of conventional thermal pasteurisation, microwave and ultrasound treatments on the phytochemical and antioxidant activities of juices from carambola (Averrhoa carambola L.), black jamun (Syzygium cumuni L.Skeels.), watermelon (Citrullus lanatus var lanatus), pineapple (Ananas comosus L. Merr) and litchi (Litchi chinensis Sonn.) was carried out. Depending on the type of fruit sample and treatment, increase or decrease in phytochemical values was observed. Overall, sonication had a positive effect on the total flavonoid content in all the juice samples followed by microwave treatment with exceptions in some cases. High-performance liquid chromatography study showed the presence of different phenolic acids depending on the sample type. The phenolic acids in some processed carambola juice samples showed decrease or complete destruction, while in some cases, an increase or appearance of newer phenolic acid originally not detected in the fresh juice was observed as seen in conventional thermal pasteurisation, microwaved at 600 W and sonicated juices. Both microwaved and sonicated samples were found to have positive effect on the phenolic content and antioxidant activity with exceptions in some cases. Therefore, microwave and sonication treatment could be used in place of thermal pasteurisation depending on the sample requirements. © The Author(s) 2015.

  12. Comparison of essential oil composition and antimicrobial activity of Coriandrum sativum L. extracted by hydrodistillation and microwave-assisted hydrodistillation.

    Science.gov (United States)

    Sourmaghi, Mohammad Hossein Salehi; Kiaee, Gita; Golfakhrabadi, Fereshteh; Jamalifar, Hossein; Khanavi, Mahnaz

    2015-04-01

    Coriander (Coriandrum sativum L.), is an annual herb in the Apiaceae family which disperses in Mediterranean and Middle Eastern regions. The Coriander essential oil has been used in food products, perfumes, cosmetics and pharmaceutical industries for its flavor and odor. In Iran, fruits of Coriander used in pickle, curry powders, sausages, cakes, pastries, biscuits and buns. The aim of this study was to investigate microwave radiation effects on quality, quantity and antimicrobial activity of essential oil of Coriander fruits. The essential oils were obtained from the Coriander fruits by hydrodistillation (HD) and Microwave-assisted hydrodistillation (MAHD) then, the oils were analyzed by GC and GC-MS. Antimicrobial activities of essential oils were evaluated against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans by microdilution method. The results indicated that the HD and MAHD essential oils (EO) were dominated by monoterpenoids such as linalool, geranyl acetate and γ-terpinene. The major compound in both EO was linalool which its amount in HD and MAHD was 63 % and 66 %, respectively. The total amount of monoterpenes hydrocarbons in HD EO differ significantly with the amount in MAHD EO (12.56 % compare to 1.82 %). HD EO showed greater activity against Staphylococcus aureus and Candida albicans than MAHD EO. Moreover, their activities against Ecoli and P. aeruginosa were the same with Minimum Inhibitory Concentration (MIC) 0.781 and 6.25 μL mL(-1), respectively. By using MAHD method, it was superior in terms of saving energy and extraction time, although the oil yield and total composition decrease by using this method.

  13. Metal-Organic Frameworks as Active Materials in Electronic Sensor Devices.

    Science.gov (United States)

    Campbell, Michael G; Dincă, Mircea

    2017-05-12

    In the past decade, advances in electrically conductive metal-organic frameworks (MOFs) and MOF-based electronic devices have created new opportunities for the development of next-generation sensors. Here we review this rapidly-growing field, with a focus on the different types of device configurations that have allowed for the use of MOFs as active components of electronic sensor devices.

  14. 77 FR 8260 - Agency Information Collection Activities; Proposed Collection; Comment Request; Medical Device...

    Science.gov (United States)

    2012-02-14

    ... will be used to evaluate risks associated with medical devices which will enable FDA to take...] Agency Information Collection Activities; Proposed Collection; Comment Request; Medical Device Reporting... comment in response to the notice. This notice solicits comments on medical device reporting (MDR...

  15. Microwave-assisted activated carbon from cocoa shell as adsorbent for removal of sodium diclofenac and nimesulide from aqueous effluents

    Energy Technology Data Exchange (ETDEWEB)

    Saucier, Caroline [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, P.O. Box 15003, 91501-970 Porto Alegre, RS (Brazil); Adebayo, Matthew A. [Department of Chemical Sciences, Ajayi Crowther University, Oyo, Oyo State (Nigeria); Lima, Eder C., E-mail: eder.lima@ufrgs.br [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, P.O. Box 15003, 91501-970 Porto Alegre, RS (Brazil); Cataluña, Renato [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, P.O. Box 15003, 91501-970 Porto Alegre, RS (Brazil); Thue, Pascal S. [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, P.O. Box 15003, 91501-970 Porto Alegre, RS (Brazil); Department of Applied Chemistry, University of Ngaoundere, P.O. Box 455, Ngaoundere (Cameroon); Prola, Lizie D.T.; Puchana-Rosero, M.J. [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, P.O. Box 15003, 91501-970 Porto Alegre, RS (Brazil); Machado, Fernando M. [Technology Development Center, Federal University of Pelotas (UFPEL), Pelotas (Brazil); Pavan, Flavio A. [Institute of Chemistry, Federal University of Pampa (UNIPAMPA), Bagé, RS (Brazil); Dotto, G.L. [Chemical Engineering Department, Federal University of Santa Maria (UFSM), Santa Maria, RS (Brazil)

    2015-05-30

    Highlights: • Microwave-assisted cocoa shell activated carbon was prepared and characterized. • The anti-inflammatories, diclofenac and nimesulide, were adsorbed onto MWCS-1.0. • Adsorption maximum values are 63.47 (diclofenac) and 74.81 mg g{sup −1} (nimesulide). • General order kinetic model suitably explained the adsorption process. • MWCS-1.0 was effectively used for treatment of simulated hospital effluents. - Abstract: Microwave-induced chemical activation process was used to prepare an activated carbon from cocoa shell for efficient removal of two anti-inflammatories, sodium diclofenac (DFC) and nimesulide (NM), from aqueous solutions. A paste was obtained from a mixture of cocoa shell and inorganic components; with a ratio of inorganic: organic of 1 (CSC-1.0). The mixture was pyrolyzed in a microwave oven in less than 10 min. The CSC-1.0 was acidified with a 6 mol L{sup −1} HCl under reflux to produce MWCS-1.0. The CSC-1.0 and MWCS-1.0 were characterized using FTIR, SEM, N{sub 2} adsorption/desorption curves, X-ray diffraction, and point of zero charge (pH{sub pzc}). Experimental variables such as initial pH of the adsorbate solutions and contact time were optimized for adsorptive characteristics of MWCS-1.0. The optimum pH for removal of anti-inflammatories ranged between 7.0 and 8.0. The kinetic of adsorption was investigated using general order, pseudo first-order and pseu do-second order kinetic models. The maximum amounts of DCF and NM adsorbed onto MWCS-1.0 at 25 °C are 63.47 and 74.81 mg g{sup −1}, respectively. The adsorbent was tested on two simulated hospital effluents. MWCS-1.0 is capable of efficient removal of DCF and NM from a medium that contains high sugar and salt concentrations.

  16. Development of a modified two-scale electromagnetic model simulating both active and passive microwave measurements: Comparison to data remotely sensed over the ocean

    Science.gov (United States)

    Boukabara, S. A.; Eymard, L.; Guillou, C.; Lemaire, D.; Sobieski, P.; Guissard, A.

    2002-08-01

    Spaceborne microwave remote sensing allows the determination of oceanic and atmospheric parameters. Operational payloads such as ERS-1 and ERS-2 and TOPEX/Poseidon as well as missions such as Jason (from NASA-Centre National d'Etudes) or Envisat (from the European Space Agency), have contained or contain paired microwave instruments looking at the nadir direction. This combination consists of microwave radiometers and a radar-altimeter. For the frequencies chosen in oceanographic satellite payloads, the active mode signal is mostly dependent on the surface state through its reflectivity and thus used for the near-surface wind speed retrieval. The active mode can also be attenuated by the atmosphere. On the other hand, the passive mode is related to the surface emissivity and the atmospheric radiation through the radiative transfer equation. Until now, the oceanic and atmospheric parameters have been retrieved separately, the latter being used to correct radar measurements. However, the reflectivity and the emissivity of a target are not independent quantities; hence the synergistic use of these two kinds of microwave measurements should allow one to improve the retrieval quality of the sea and atmosphere parameters. For this purpose, a unified model has been developed for the simulation of both the microwave backscattering coefficient σ° (active measurement) and the microwave emissivity, an important factor for the brightness temperature TB simulation, for every configuration (incidence angles, frequency, polarizations), taking into account the fact that the reflectivity and the emissivity are complementary to unity. The atmospheric absorption is computed following a widely used model from the literature. This paper gives a description and a first attempt of validation of this approach through a comparison with real data. The performance of the model is assessed by comparing the simulations to both brightness temperatures and backscattering coefficients from ERS

  17. Soil Moisture ActivePassive (SMAP) L-Band Microwave Radiometer Post-Launch Calibration

    Science.gov (United States)

    Peng, Jinzheng; Piepmeier, Jeffrey R.; Misra, Sidharth; Dinnat, Emmanuel P.; Hudson, Derek; Le Vine, David M.; De Amici, Giovanni; Mohammed, Priscilla N.; Yueh, Simon H.; Meissner, Thomas

    2016-01-01

    The SMAP microwave radiometer is a fully-polarimetric L-band radiometer flown on the SMAP satellite in a 6 AM/ 6 PM sun-synchronous orbit at 685 km altitude. Since April, 2015, the radiometer is under calibration and validation to assess the quality of the radiometer L1B data product. Calibration methods including the SMAP L1B TA2TB (from Antenna Temperature (TA) to the Earth’s surface Brightness Temperature (TB)) algorithm and TA forward models are outlined, and validation approaches to calibration stability/quality are described in this paper including future work. Results show that the current radiometer L1B data satisfies its requirements.

  18. Modification of bamboo-based activated carbon using microwave radiation and its effects on the adsorption of methylene blue

    Energy Technology Data Exchange (ETDEWEB)

    Liu Qingsong; Zheng Tong; Li Nan [State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China); Wang Peng, E-mail: pwang73@vip.sina.com [State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China); Abulikemu, Gulizhaer [State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China)

    2010-03-01

    Modification of bamboo-based activated carbon was carried out in a microwave oven under N{sub 2} atmosphere. The virgin and modified activated carbons were characterized by means of low temperature N{sub 2} adsorption, acid-base titration, point of zero charge (pH{sub pzc}) measurement, FTIR and XPS spectra. A gradual decrease in the surface acidic groups was observed during the modification, while the surface basicity was enhanced to some extent, which gave rise to an increase in the pH{sub pzc} value. The species of the functional groups and relative content of various elements and groups were given further analysis using FTIR and XPS spectra. An increase in the micropores was found at the start, and the micropores were then extended into larger ones, resulting in an increase in the pore volume and average pore size. Adsorption studies showed enhanced adsorption of methylene blue on the modified activated carbons, caused mainly by the enlargement of the micropores. Adsorption isotherm fittings revealed that Langmuir and Freundlich models were applicable for the virgin and modified activated carbons, respectively. Kinetic studies exhibited faster adsorption rate of methylene blue on the modified activated carbons, and the pseudo-second-order model fitted well for all of the activated carbons.

  19. Modification of bamboo-based activated carbon using microwave radiation and its effects on the adsorption of methylene blue

    Science.gov (United States)

    Liu, Qing-Song; Zheng, Tong; Li, Nan; Wang, Peng; Abulikemu, Gulizhaer

    2010-03-01

    Modification of bamboo-based activated carbon was carried out in a microwave oven under N 2 atmosphere. The virgin and modified activated carbons were characterized by means of low temperature N 2 adsorption, acid-base titration, point of zero charge (pH pzc) measurement, FTIR and XPS spectra. A gradual decrease in the surface acidic groups was observed during the modification, while the surface basicity was enhanced to some extent, which gave rise to an increase in the pH pzc value. The species of the functional groups and relative content of various elements and groups were given further analysis using FTIR and XPS spectra. An increase in the micropores was found at the start, and the micropores were then extended into larger ones, resulting in an increase in the pore volume and average pore size. Adsorption studies showed enhanced adsorption of methylene blue on the modified activated carbons, caused mainly by the enlargement of the micropores. Adsorption isotherm fittings revealed that Langmuir and Freundlich models were applicable for the virgin and modified activated carbons, respectively. Kinetic studies exhibited faster adsorption rate of methylene blue on the modified activated carbons, and the pseudo-second-order model fitted well for all of the activated carbons.

  20. Modification of bamboo-based activated carbon using microwave radiation and its effects on the adsorption of methylene blue

    International Nuclear Information System (INIS)

    Liu Qingsong; Zheng Tong; Li Nan; Wang Peng; Abulikemu, Gulizhaer

    2010-01-01

    Modification of bamboo-based activated carbon was carried out in a microwave oven under N 2 atmosphere. The virgin and modified activated carbons were characterized by means of low temperature N 2 adsorption, acid-base titration, point of zero charge (pH pzc ) measurement, FTIR and XPS spectra. A gradual decrease in the surface acidic groups was observed during the modification, while the surface basicity was enhanced to some extent, which gave rise to an increase in the pH pzc value. The species of the functional groups and relative content of various elements and groups were given further analysis using FTIR and XPS spectra. An increase in the micropores was found at the start, and the micropores were then extended into larger ones, resulting in an increase in the pore volume and average pore size. Adsorption studies showed enhanced adsorption of methylene blue on the modified activated carbons, caused mainly by the enlargement of the micropores. Adsorption isotherm fittings revealed that Langmuir and Freundlich models were applicable for the virgin and modified activated carbons, respectively. Kinetic studies exhibited faster adsorption rate of methylene blue on the modified activated carbons, and the pseudo-second-order model fitted well for all of the activated carbons.

  1. Remote detection and ecological monitoring of the industrial and natural nuclei activity of radioactive elements based on passive microwave radiometry

    Science.gov (United States)

    Chistyakova, Liliya K.; Chistyakov, Vyacheslav Y.; Losev, Dmitry V.; Penin, Sergei T.; Tarabrin, Yurij K.; Yakubov, Vladimir P.; Yurjev, Igor A.

    1998-12-01

    The passive remote method of microwave radiometry and its instrumental realization for express diagnostics of radioactive elements in the atmosphere have been discussed. Analysis of the microwave radiation due to ionization and dissociation of atmospheric components interacting with radioactive elements is carried out. The photochemical processes resulting in background microwave radiation power have been discussed. As an example, the results of natural experiment of detecting the atomic hydrogen radiation in the plume of emissions of nuclear cycle processing plants have been presented.

  2. Microwave Assisted Synthesis of Some New Fused 1,2,4-Triazines Bearing Thiophene Moieties With Expected Pharmacological Activity

    Directory of Open Access Journals (Sweden)

    Mosselhi A. Mosselhi

    2011-06-01

    Full Text Available Rapid and efficient solvent-free synthesis of 4-amino-3-mercapto-6-[2-(2-thienylvinyl]-1,2,4-triazin-5(4H-one 1 under microwave irradiation is described. Some new fused heterobicyclic nitrogen systems such as 1,2,4-triazino[3,4-b][1,3,4]thiadiazinones, 1,3,4-thiadiazolo[2,3-c][1,2,4]triazinone and pyrazolo[5,1-c]-[1,2,4]triazine-7-carbonitrile, have been synthesized by treatment of 1 with bifunctional oxygen and halogen compounds, CS2/KOH and malononitrile via heterocyclization reactions, in addition to some uncondensed triazines. Structures of the products have been deduced from their elemental analysis and spectral data (IR, 1H-NMR, 13C-NMR. Select new synthesized compounds were screened as anticancer agents, with some showing activity as cytotoxic agents against different cancer cell lines.

  3. The Effect of Gamma radiation, microwave radiation, their interaction and storage on chemical composition, antinutritional factors and the activities of trypsin inhibitor and lipoxygenase of soybean seeds

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Rahim, E A; Abdel-Fatah, O M [Dept. of Biochem., Faculty of Agric., Cairo University. (Egypt); El-Adawy, M; Badea, M Y [Food Technol. Dept., National Center for Research and Radiation Technol., Atomic Energy Authority (Egypt)

    2000-07-01

    The effect of gamma radiation, microwave radiation, interaction between them; and storage of radiated soybean seeds were investigated to find out the best treatment which had to the maximum reduction of antinutrional factors (Trypsin inhibitor and lipoxygenase activities) without significant effect on the chemical constituents. The gamma rays was used at three doses of 2.5, 5.0 and 8.0 kGy, microwave radiation was at 70 level power for 2 and 4 min; and the storage of seeds was at temperature, R.H. 50-55% for six months. The data revealed that, effects of interaction treatments were more effective than the treatment with microwave or gamma radiation alone.

  4. The Effect of Gamma radiation, microwave radiation, their interaction and storage on chemical composition, antinutritional factors and the activities of trypsin inhibitor and lipoxygenase of soybean seeds

    International Nuclear Information System (INIS)

    Abdel-Rahim, E.A.; Abdel-Fatah, O.M.; El-Adawy, M.; Badea, M.Y.

    2000-01-01

    The effect of gamma radiation, microwave radiation, interaction between them; and storage of radiated soybean seeds were investigated to find out the best treatment which had to the maximum reduction of antinutrional factors (Trypsin inhibitor and lipoxygenase activities) without significant effect on the chemical constituents. The gamma rays was used at three doses of 2.5, 5.0 and 8.0 kGy, microwave radiation was at 70 level power for 2 and 4 min; and the storage of seeds was at temperature, R.H. 50-55% for six months. The data revealed that, effects of interaction treatments were more effective than the treatment with microwave or gamma radiation alone

  5. Effect of drying methods with the application of vacuum microwaves on the bioactive compounds, color, and antioxidant activity of strawberry fruits.

    Science.gov (United States)

    Wojdyło, Aneta; Figiel, Adam; Oszmiański, Jan

    2009-02-25

    The objective of this study was to evaluate the application of vacuum-microwave drying (240, 360, and 480 W) in the production process of dehydrated strawberry and to compare and contrast the quality of these dehydrated strawberries in terms of their polyphenol compounds, concentration of some heat liable components, and color to that of freeze-dried, convective, and vacuum-dried strawberry. Thus, the effect of vacuum-microwave drying and other drying methods on the antioxidant activity of berries was evaluated. Whole fresh and dried fruits were assessed for phenolics (anthocyanins, flavanols, hydroxycinnamic acids, and flavonols), ascorbic acid, and antioxidant activity (all parameters were calculated on a dry matter basis). Analysis of data shows that ellagic acid and flavanol changes were affected by drying techniques and cultivar. Drying destroyed anthocyanins, flavanols, and ascorbic acid, and there was a significant decrease in antioxidant activity. The most striking result was that conventional and vacuum drying decreased antioxidant activity in both cultivars, whereas contradictory results were found for vacuum-microwave processed strawberry. This study has demonstrated that vacuum-microwave drying, especially at 240 W, can produce high-quality products, with the additional advantage of reduced processing times, compared to other processes such as freeze-drying.

  6. A Facile Solvent Free Microwave Induced Synthesis and Antibacterial Activity of Some 3-(2’-Hydroxyphenyl-5-(Substituted Aryl-2-Pyrazoline-N1-Caboxaldehydes

    Directory of Open Access Journals (Sweden)

    Birbal Bajia

    2007-01-01

    Full Text Available A novel one pot formylation of 3-(2’-hydroxyphenyl-5-(substituted 2-pyrazolines has been carried out using microwave irradiation with formic acid. solvent free reaction afforded title compounds in 80-90% yield with high purity.synthesized compounds were tested for their antibacterial activity using standard drug.

  7. Microwave-assisted combustion synthesis of nano iron oxide/iron-coated activated carbon, anthracite, cellulose fiber, and silica, with arsenic adsorption studies

    Science.gov (United States)

    Combustion synthesis of iron oxide/iron coated carbons such as activated carbon, anthracite, cellulose fiber and silica is described. The reactions were carried out in alumina crucibles using a Panasonic kitchen microwave with inverter technology, and the reaction process was com...

  8. Microwave pyrolysis using self-generated pyrolysis gas as activating agent: An innovative single-step approach to convert waste palm shell into activated carbon

    Science.gov (United States)

    Yek, Peter Nai Yuh; Keey Liew, Rock; Shahril Osman, Mohammad; Chung Wong, Chee; Lam, Su Shiung

    2017-11-01

    Waste palm shell (WPS) is a biomass residue largely available from palm oil industries. An innovative microwave pyrolysis method was developed to produce biochar from WPS while the pyrolysis gas generated as another product is simultaneously used as activating agent to transform the biochar into waste palm shell activated carbon (WPSAC), thus allowing carbonization and activation to be performed simultaneously in a single-step approach. The pyrolysis method was investigated over a range of process temperature and feedstock amount with emphasis on the yield and composition of the WPSAC obtained. The WPSAC was tested as dye adsorbent in removing methylene blue. This pyrolysis approach provided a fast heating rate (37.5°/min) and short process time (20 min) in transforming WPS into WPSAC, recording a product yield of 40 wt%. The WPSAC was detected with high BET surface area (≥ 1200 m2/g), low ash content (< 5 wt%), and high pore volume (≥ 0.54 cm3/g), thus recording high adsorption efficiency of 440 mg of dye/g. The desirable process features (fast heating rate, short process time) and the recovery of WPSAC suggest the exceptional promise of the single-step microwave pyrolysis approach to produce high-grade WPSAC from WPS.

  9. Recommended safety procedures for the installation and use of radiofrequency and microwave devices in the frequency range 10 MHz-300 GHz

    International Nuclear Information System (INIS)

    1979-02-01

    Studies of possible hazards to human health from exposure to radio frequency and microwave radiation show that there is a need for controls. Exposure to high levels of radio frequency and microwave radiation over prolonged periods can cause adverse health effects. The type and extent of injury depend not only on the intensity (strength) of the field and the exposure duration but also on various other factors such as the frequency of the radiation, type of modulation, polarization, and distance from the source. (auth)

  10. Microwave Measurements

    CERN Document Server

    Skinner, A D

    2007-01-01

    The IET has organised training courses on microwave measurements since 1983, at which experts have lectured on modern developments. Their lecture notes were first published in book form in 1985 and then again in 1989, and they have proved popular for many years with a readership beyond those who attended the courses. The purpose of this third edition of the lecture notes is to bring the latest techniques in microwave measurements to this wider audience. The book begins with a survey of the theory of current microwave circuits and continues with a description of the techniques for the measureme

  11. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2006-01-01

    Wireless, optical, and electronic networks continue to converge, prompting heavy research into the interface between microwave electronics, ultrafast optics, and photonic technologies. New developments arrive nearly as fast as the photons under investigation, and their commercial impact depends on the ability to stay abreast of new findings, techniques, and technologies. Presenting a broad yet in-depth survey, Microwave Photonics examines the major advances that are affecting new applications in this rapidly expanding field.This book reviews important achievements made in microwave photonics o

  12. Microwave processing of honey negatively affects honey antibacterial activity by inactivation of bee-derived glucose oxidase and defensin-1.

    Science.gov (United States)

    Bucekova, Marcela; Juricova, Valeria; Monton, Enrique; Martinotti, Simona; Ranzato, Elia; Majtan, Juraj

    2018-02-01

    Microwave (MW) thermal heating has been proposed as an efficient method for honey liquefaction, while maintaining honey quality criteria. However, little is known about the effects of MW thermal heating on honey antibacterial activity. In this study, we aimed to determine the effects of MW heating on the antibacterial activity of raw rapeseed honeys against Pseudomonas aeruginosa and Staphylococcus aureus, with a particular focus on two major bee-derived antibacterial components, defensin-1 and hydrogen peroxide (H 2 O 2 ). Our results demonstrated that MW thermal heating completely abolished honey antibacterial activity whereas conventional thermal treatment at 45 and 55°C did not affect the antibacterial activity of honey samples. A significant decrease in both glucose oxidase activity and H 2 O 2 production as well as defensin-1 amount was observed in MW-treated samples. Given that defensin-1 and H 2 O 2 are regular antibacterial components of all honeys, MW heating may have similar negative effects on every type of crystallized/liquid honey. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Microwave Assisted Drug Delivery

    DEFF Research Database (Denmark)

    Jónasson, Sævar Þór; Zhurbenko, Vitaliy; Johansen, Tom Keinicke

    2014-01-01

    In this work, the microwave radiation is adopted for remote activation of pharmaceutical drug capsules inside the human body in order to release drugs at a pre-determined time and location. An array of controllable transmitting sources is used to produce a constructive interference at a certain...... focus point inside the body, where the drugs are then released from the specially designed capsules. An experimental setup for microwave activation has been developed and tested on a body phantom that emulates the human torso. A design of sensitive receiving structures for integration with a drug...

  14. Wireless power pad with local power activation for portable devices

    NARCIS (Netherlands)

    Waffenschmidt, E.; Zheglov, V.

    2007-01-01

    Wireless power transfer by magnetic induction offers a simple to use way to recharge mobile devices like e.g. mobile phone, music players or medical sensors. As shown by a previous report and an existing Power Pad demonstrator, wireless inductive power transfer is possible with a good power

  15. Microwave-assisted ionothermal synthesis of nanostructured anatase titanium dioxide/activated carbon composite as electrode material for capacitive deionization

    International Nuclear Information System (INIS)

    Liu, Po-I; Chung, Li-Ching; Shao, Hsin; Liang, Teh-Ming; Horng, Ren-Yang; Ma, Chen-Chi M.; Chang, Min-Chao

    2013-01-01

    The nanostructured anatase titanium dioxide/activated carbon composite material for capacitive deionization electrode was prepared in a short time by a lower temperature two-step microwave-assisted ionothermal (sol–gel method in the presence of ionic liquid) synthesis method. This method includes a reaction and a crystallization step. In the crystallization step, the ionic liquid plays a hydrothermal analogy role in driving the surface anatase crystallization of amorphous titanium dioxide nanoparticles formed in the reaction step. The energy dispersive spectroscopic study of the composite indicates that the anatase titanium dioxide nanoparticles are evenly deposited in the matrix of activated carbon. The electrochemical property of the composite electrode was investigated. In comparison to the pristine activated carbon electrode, higher specific capacitance was observed for the nanostructured anatase titanium dioxide/activated carbon composite electrode, especially when the composite was prepared with a molar ratio of titanium tetraisopropoxide/H 2 O equal to 1:15. Its X-ray photoelectron spectroscopic result indicates that it has the highest amount of Ti-OH. The Ti-OH group can enhance the wetting ability and the specific capacitance of the composite electrode. The accompanying capacitive deionization result indicates that the decay of electrosorption capacity of this composite electrode is insignificant after five cycle tests. It means that the ion electrosorption–desorption becomes a reversible process

  16. Microwave assisted hydrothermal synthesis of Ag/AgCl/WO3 photocatalyst and its photocatalytic activity under simulated solar light

    International Nuclear Information System (INIS)

    Adhikari, Rajesh; Gyawali, Gobinda; Sekino, Tohru; Wohn Lee, Soo

    2013-01-01

    Simulated solar light responsive Ag/AgCl/WO 3 composite photocatalyst was synthesized by microwave assisted hydrothermal process. The synthesized powders were characterized by X-Ray Diffraction (XRD) spectroscopy, X-Ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM), Diffuse Reflectance Spectroscopy (UV–Vis DRS), and BET surface area analyzer to investigate the crystal structure, morphology, chemical composition, optical properties and surface area of the composite photocatalyst. This photocatalyst exhibited higher photocatalytic activity for the degradation of rhodamine B under simulated solar light irradiation. Dye degradation efficiency of composite photocatalyst was found to be increased significantly as compared to that of the commercial WO 3 nanopowder. Increase in photocatalytic activity of the photocatalyst was explained on the basis of surface plasmon resonance (SPR) effect caused by the silver nanoparticles present in the composite photocatalyst. Highlights: ► Successful synthesis of Ag/AgCl/WO 3 nanocomposite. ► Photocatalytic experiment was performed under simulated solar light. ► Nanocomposite photocatalyst was very active as compared to WO 3 commercial powder. ► SPR effect due to Ag nanoparticles enhanced the photocatalytic activity.

  17. Optimization of microwave-assisted durian seed based activated carbon preparation conditions for methylene blue dye removal

    Science.gov (United States)

    Ahmad, Mohd Azmier; Hamid, Siti Ruqayyah Ab.; Yusop, Mohamad Firdaus Mohamad; Aziz, Hamidi Abdul

    2017-10-01

    Due to easy access and relatively high fixed carbon content of 26.13% in its raw form, durian seed based activated carbon (DSAC) was produced via microwave heating. For activation stage, physiochemical approach consist of carbon dioxide (CO2) gasification and potassium hydroxide (KOH) as chemical activator were employed. Three most influential preparation variables on adsorption performance and yield of activated carbon (AC), which is radiation power, radiation time and KOH impregnation ratio (IR) were optimized with the help of response surface methodology (RSM). The optimization result revealed that 440W, 4.0 minutes and 0.55 of radiation power, radiation time and IR respectively, were needed to remove 80.23% of methylene blue (MB) dye and to obtain 25.77% of DSAC's yield. High Brunauer-Emmet-Teller (BET) surface area, total pore volume and average pore size of 852.30m2/g, 0.465cm3/g and 3.74nm respectively, were obtained on optimized DSAC.

  18. Study of photocatalytic activities of Bi{sub 2}WO{sub 6} nanoparticles synthesized by fast microwave-assisted method

    Energy Technology Data Exchange (ETDEWEB)

    Phu, Nguyen Dang [Faculty of Physics, Hanoi National University of Education, 136 Xuanthuy, Cau Giay, Hanoi (Viet Nam); Hoang, Luc Huy, E-mail: hoanglhsp@hnue.edu.vn [Faculty of Physics, Hanoi National University of Education, 136 Xuanthuy, Cau Giay, Hanoi (Viet Nam); Chen, Xiang-Bai, E-mail: xchen@wit.edu.cn [School of Science and Laboratory of Optical Information Technology, Wuhan Institute of Technology, Wuhan 430205 (China); Kong, Meng-Hong [School of Science and Laboratory of Optical Information Technology, Wuhan Institute of Technology, Wuhan 430205 (China); Wen, Hua-Chiang; Chou, Wu Ching [Department of Electrophysics, National Chiao Tung University, Hsin-Chu 30010, Taiwan (China)

    2015-10-25

    We present a study of photocatalytic activities of Bi{sub 2}WO{sub 6} nanoparticles synthesized by fast microwave-assisted method. The photocatalytic activities of the nanoparticles were evaluated by the decolorization of methylene-blue under visible-light-irradiation. Our results show that the surface area of Bi{sub 2}WO{sub 6} nanoparticles plays a major role for improving photocatalytic activity, while visible-light absorption has only a weak effect on photocatalytic activity. This suggests efficient transportation of photo-generated electrons and holes to the oxidation active sites on the surface of nanoparticles, indicating Bi{sub 2}WO{sub 6} nanoparticles synthesized by fast microwave-assisted method are promising for achieving high photocatalytic activity under visible-light-irradiation. - Highlights: • The Bi{sub 2}WO{sub 6} nanoparticles were synthesized via fast microwave-assisted method. • The obtained Bi{sub 2}WO{sub 6} nanoparticles exhibited visible-light absorbance. • The surface area of Bi{sub 2}WO{sub 6} nanoparticles plays major role for improving photocatalytic activity. • The Bi{sub 2}WO{sub 6} nanoparticles are promising for achieving high photocatalytic activity under visible-light-irradiation.

  19. Muscle activity of leg muscles during unipedal stance on therapy devices with different stability properties.

    Science.gov (United States)

    Wolburg, Thomas; Rapp, Walter; Rieger, Jochen; Horstmann, Thomas

    2016-01-01

    To test the hypotheses that less stable therapy devices require greater muscle activity and that lower leg muscles will have greater increases in muscle activity with less stable therapy devices than upper leg muscles. Cross-sectional laboratory study. Laboratory setting. Twenty-five healthy subjects. Electromyographic activity of four lower (gastrocnemius medialis, soleus, tibialis anterior, peroneus longus) and four upper leg muscles (vastus medialis and lateralis, biceps femoris, semitendinosus) during unipedal quiet barefoot stance on the dominant leg on a flat rigid surface and on five therapy devices with varying stability properties. Muscle activity during unipedal stance differed significantly between therapy devices (P < 0.001). The order from lowest to highest relative muscle activity matched the order from most to least stable therapy device. There was no significant interaction between muscle location (lower versus upper leg) and therapy device (P = 0.985). Magnitudes of additional relative muscle activity for the respective therapy devices differed substantially among lower extremity muscles. The therapy devices offer a progressive increase in training intensity, and thus may be useful for incremental training programs in physiotherapeutic practice and sports training programs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Drying behaviour, effective diffusivity and energy of activation of olive leaves dried by microwave, vacuum and oven drying methods

    Science.gov (United States)

    Elhussein, Elaf Abdelillah Ali; Şahin, Selin

    2018-01-01

    Drying is the crucial food processing for bioactive components from plant materials before strating extraction in addition to preservation of raw plant materials during storage period. Olive leaves were dried by various methods such as microwave drying (MD), oven drying (OD) and vacuum drying (VD) at several temperature values in the present study. Mathematical models allow to develop, design and control the processes. 14 emprical equations were used to estimate the drying behaviour and the time required for drying. Convenience of the models were evaluated according to the correlation coefficient (R 2 ), varience (S 2 ) and root mean square deviation (D RMS ). On the other hand, the effective diffusion coefficient and energy for activation were also calculated. Effects of the drying methods on the total phenolic (TPC), flavonoid (TFC) and oleuropein contents and free radical scavenging activity (FRSA) of the olive leaves were also investigated to take into considiration the quality of the dried product. MD has proved to be the fastest drying method having the highest effective diffusivity and the lowest activation energy with a more qualitive product.

  1. Microwave-Assisted Synthesis of 3,5-Dibenzyl-4-amino-1,2,4-triazole and its Diazo Ligand, Metal Complexes Along with Anticancer Activity

    Directory of Open Access Journals (Sweden)

    Anjali Jha

    2010-01-01

    Full Text Available Synthesis of 3,5-dibenzyl-4-amino-1,2,4-triazole was accomplished via a conventional method as well as microwave irradiation method, followed by diazotization and coupling with 2,4-pentanedione. The dinucleating ligand was isolated and complexed with Ni(II, Cu(II and Ru(III chlorides. These complexes were screened on Jurkat, Raji & PBMC cell lines for anticancer activity. Ruthenium complexes showed potential anticancer activities.

  2. Microwave dielectric properties of nanostructured nickel ferrite

    Indian Academy of Sciences (India)

    Wintec

    Abstract. Nickel ferrite is one of the important ferrites used in microwave devices. In the present work, we have synthesized nanoparticles of nickel ferrite using chemical precipitation technique. The crystal structure and grain size of the particles are studied using XRD. The microwave dielectric properties of nanostructured.

  3. The use of design of experiments for the evaluation of the production of surface rich activated carbon from sewage sludge via microwave and conventional pyrolysis

    International Nuclear Information System (INIS)

    Simões dos Reis, Glaydson; Wilhelm, Michaela; Silva, Thamires Canuto de Almeida; Rezwan, Kurosch; Sampaio, Carlos Hoffmann; Lima, Eder Claudio; Guelli Ulson de Souza, Selene M.A.

    2016-01-01

    Highlights: • Using of DOE for preparation of AC by conventional and microwave pyrolysis. • The significant parameters in producing activated carbon were investigated. • Conventional pyrolysis AC had better textural development than microwave AC. • Temperature and holding time had significant influence on the S_B_E_T. • Reduction of production cost of activated carbon. - Abstract: Experimental design and response surface methodology were used for the preparation and comparison of activated carbon produced from sewage sludge by two types of pyrolysis: conventional furnace and microwave. The preparation method was performed following a full fractional factorial design (2"3), including pyrolysis temperature or power radiation, holding time and chemical activation agent, and specific surface area (S_B_E_T) of prepared activated carbon. The influence of these factors on the S_B_E_T of obtained carbon was investigated using an analysis of variance. Samples made by conventional pyrolysis showed overall higher S_B_E_T values than samples synthesised by the microwave method. The optimum parameters for the preparation of activated carbon using the conventional pyrolysis have been identified as: pyrolysis temperature of 500 °C, holding time of 15 min, and a ratio of ZnCl_2:sludge of 0.5. Microwave pyrolysis is found to be optimal when operating at 980 W for 12 min. Under these conditions, S_B_E_T values of 679 and 501 m"2g"−"1, respectively, have been obtained. The analysis of nitrogen adsorption/desorption isotherms revealed the presence of micro and mesopores in the activated carbon. The most important significant factor, according statistical analysis, in the variance in S_B_E_T for the conventional pyrolysis samples were the pyrolysis temperature and interaction between pyrolysis temperature, holding time and ratio of ZnCl_2:sludge were the most important factors. The highest impact parameters for the microwave method were found for the interaction

  4. Beam-plasma generators of stochastic microwave oscillations using for plasma heating in fusion and plasma-chemistry devices and ionospheric investigations

    Energy Technology Data Exchange (ETDEWEB)

    Mitin, L A; Perevodchikov, V I; Shapiro, A L; Zavyalov, M A [All-Russian Electrotechnical Inst., Moscow (Russian Federation); Bliokh, Yu P; Fajnberg, Ya B [Kharkov Inst. of Physics and Technology (Russian Federation)

    1997-12-31

    The results of theoretical and experimental investigations of a generator of stochastic microwave power based on a beam-plasma inertial feedback amplifier is discussed with a view to using stochastic oscillations for plasma heating. The plasma heating efficiency in the region of low-frequency resonance in the geometry of the Tokamak is considered theoretically. It is shown that the temperature of heating is proportional to the power multiplied by the spectra width of the noiselike signal. The creation and heating of plasma by stochastic microwave power in an oversized waveguide without external magnetic field is discussed with a view to plasma-chemistry applications. It is shown that the efficiency of heating are defined by the time of phase instability of the stochastic power. (author). 3 figs., 13 refs.

  5. 24 Hours of Sleep, Sedentary Behavior, and Physical Activity with Nine Wearable Devices

    OpenAIRE

    Rosenberger, Mary E.; Buman, Matthew P.; Haskell, William L.; McConnell, Michael V.; Carstensen, Laura L.

    2016-01-01

    Getting enough sleep, exercising and limiting sedentary activities can greatly contribute to disease prevention and overall health and longevity. Measuring the full 24-hour activity cycle - sleep, sedentary behavior (SED), light intensity physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) - may now be feasible using small wearable devices.

  6. Estimation of Hydraulic properties of a sandy soil using ground-based active and passive microwave remote sensing

    KAUST Repository

    Jonard, François

    2015-06-01

    In this paper, we experimentally analyzed the feasibility of estimating soil hydraulic properties from 1.4 GHz radiometer and 0.8-2.6 GHz ground-penetrating radar (GPR) data. Radiometer and GPR measurements were performed above a sand box, which was subjected to a series of vertical water content profiles in hydrostatic equilibrium with a water table located at different depths. A coherent radiative transfer model was used to simulate brightness temperatures measured with the radiometer. GPR data were modeled using full-wave layered medium Green\\'s functions and an intrinsic antenna representation. These forward models were inverted to optimally match the corresponding passive and active microwave data. This allowed us to reconstruct the water content profiles, and thereby estimate the sand water retention curve described using the van Genuchten model. Uncertainty of the estimated hydraulic parameters was quantified using the Bayesian-based DREAM algorithm. For both radiometer and GPR methods, the results were in close agreement with in situ time-domain reflectometry (TDR) estimates. Compared with radiometer and TDR, much smaller confidence intervals were obtained for GPR, which was attributed to its relatively large bandwidth of operation, including frequencies smaller than 1.4 GHz. These results offer valuable insights into future potential and emerging challenges in the development of joint analyses of passive and active remote sensing data to retrieve effective soil hydraulic properties.

  7. Experimental study on removals of SO2 and NOX using adsorption of activated carbon/microwave desorption.

    Science.gov (United States)

    Ma, Shuang-Chen; Yao, Juan-Juan; Gao, Li; Ma, Xiao-Ying; Zhao, Yi

    2012-09-01

    Experimental studies on desulfurization and denitrification were carried out using activated carbon irradiated by microwave. The influences of the concentrations of nitric oxide (NO) and sulfur dioxide (SO 2 ), the flue gas coexisting compositions, on adsorption properties of activated carbon and efficiencies of desulfurization and denitrification were investigated. The results show that adsorption capacity and removal efficiency of NO decrease with the increasing of SO 2 concentrations in flue gas; adsorption capacity of NO increases slightly first and drops to 12.79 mg/g, and desulfurization efficiency descends with the increasing SO 2 concentrations. Adsorption capacity of SO 2 declines with the increasing of O 2 content in flue gas, but adsorption capacity of NO increases, and removal efficiencies of NO and SO 2 could be larger than 99%. Adsorption capacity of NO declines with the increase of moisture in the flue gas, but adsorption capacity of SO 2 increases and removal efficiencies of NO and SO 2 would be relatively stable. Adsorption capacities of both NO and SO 2 decrease with the increasing of CO 2 content; efficiencies of desulfurization and denitrification augment at the beginning stage, then start to fall when CO 2 content exceeds 12.4%. The mechanisms of this process are also discussed. [Box: see text].

  8. Electrodermal Activity Based Wearable Device for Drowsy Drivers

    Science.gov (United States)

    Malathi, D.; Dorathi Jayaseeli, JD; Madhuri, S.; Senthilkumar, K.

    2018-04-01

    Road safety and road accident mortality rate are a serious concern for the government. With rise in fatal road accidents, who’s leading cause is the driver being drowsy behind the wheel, measures to alleviate this problem becomes the prime task. To meet the purpose, methods adopted must be of minimum discomfort for the driver, easy to install, provide good detection accuracy and timely alert to circumvent a probable accident. A good candidate to meet these specifications is EDA. As it detects the level of sweat which directly corresponds to the mental state of the person, using EDA for the purposes of driver safety forms a good option. The novelty of this project lies in making use of EDA as a measure to detect if a person is drowsy or not. Much of the challenge lies in building a device equipped with the necessary sensors and processing the data on real-time. The novelty of this work lies in development of an embedded device interfaced with sensors and actuators to detect and alert a driver when found drowsy using sweat as a parameter.

  9. Hybrid Microwave Technology

    International Nuclear Information System (INIS)

    Wicks, G.G.

    2001-01-01

    A team associated with a Federal Laboratory, academia, and industry has been actively developing new microwave technology for treatment and remediation of a variety of potentially hazardous materials for almost a decade. This collaboration has resulted in unique equipment and processes with potential applicability to many fields, including disposition of electronic circuitry and components, medical wastes, radioactive materials and recycling of used tires

  10. Microwave hematoma detector

    Science.gov (United States)

    Haddad, Waleed S.; Trebes, James E.; Matthews, Dennis L.

    2001-01-01

    The Microwave Hematoma Detector is a non-invasive device designed to detect and localize blood pooling and clots near the outer surface of the body. While being geared towards finding sub-dural and epi-dural hematomas, the device can be used to detect blood pooling anywhere near the surface of the body. Modified versions of the device can also detect pneumothorax, organ hemorrhage, atherosclerotic plaque in the carotid arteries, evaluate perfusion (blood flow) at or near the body surface, body tissue damage at or near the surface (especially for burn assessment) and be used in a number of NDE applications. The device is based on low power pulsed microwave technology combined with a specialized antenna, signal processing/recognition algorithms and a disposable cap worn by the patient which will facilitate accurate mapping of the brain and proper function of the instrument. The invention may be used for rapid, non-invasive detection of sub-dural or epi-dural hematoma in human or animal patients, detection of hemorrhage within approximately 5 cm of the outer surface anywhere on a patient's body.

  11. Development of new low activation aluminum alloys for fusion devices

    International Nuclear Information System (INIS)

    Kamada, Kohji; Kakihana, Hidetake.

    1985-01-01

    As the materials for the R facility (a tokamak nuclear fusion device in the R project intended for D-T burning) in the Institute of Plasma Physics, Nagoya University, Al-4 % Mg-0.2 % Bi (5083 improved type) and Al-4 % Mg-1 % Li, aimed at low radioactivability, high electric resistance and high strength, have been developed. The results of the nuclear properties evaluation with 14 MeV neutrons and of the measurements of electric resistance and mechanical properties were satisfactory. The possibility of producing large Al-4 % Mg-1 % Li plate (1 m x 2 m x 25 mm) in the existing factory was confirmed, with the properties retained. The electric resistances were higher than those in the conventional aluminum alloys, and still with feasibility for the further improvement. General properties of the fusion aluminum alloys and the 26 Al formation in (n, 2n) reaction were studied. (Mori, K.)

  12. MEMS Device Being Developed for Active Cooling and Temperature Control

    Science.gov (United States)

    Moran, Matthew E.

    2001-01-01

    High-capacity cooling options remain limited for many small-scale applications such as microelectronic components, miniature sensors, and microsystems. A microelectromechanical system (MEMS) is currently under development at the NASA Glenn Research Center to meet this need. It uses a thermodynamic cycle to provide cooling or heating directly to a thermally loaded surface. The device can be used strictly in the cooling mode, or it can be switched between cooling and heating modes in milliseconds for precise temperature control. Fabrication and assembly are accomplished by wet etching and wafer bonding techniques routinely used in the semiconductor processing industry. Benefits of the MEMS cooler include scalability to fractions of a millimeter, modularity for increased capacity and staging to low temperatures, simple interfaces and limited failure modes, and minimal induced vibration.

  13. Water Pollution Scrubber Activity Simulates Pollution Control Devices.

    Science.gov (United States)

    Kennedy, Edward C., III; Waggoner, Todd C.

    2003-01-01

    A laboratory activity caused students to think actively about water pollution. The students realized that it would be easier to keep water clean than to remove pollutants. They created a water scrubbing system allowing them to pour water in one end and have it emerge clean at the other end. (JOW)

  14. Probing the local microwave properties of superconducting thin films by a scanning microwave near-field microscope

    CERN Document Server

    Wu, L Y; Wang, K L; Jiang, T; Kang, L; Yang, S Z; Wu, P H

    2002-01-01

    In this paper, we present our approach to probe the local microwave properties of superconducting thin films by using the microwave near-field scanning technique. We have employed a coaxial cavity together with a niobium tip as the probe and established a scanning sample stage cooled by liquid nitrogen to study thin film devices at low temperature in our scanning microwave near-field microscope. Nondestructive images have been obtained on the inhomogeneity of the YBaCuO superconducting thin films at microwave frequency. We believe that these results would be helpful in evaluating the microwave performance of the devices.

  15. Haptic device development based on electro static force of cellulose electro active paper

    Science.gov (United States)

    Yun, Gyu-young; Kim, Sang-Youn; Jang, Sang-Dong; Kim, Dong-Gu; Kim, Jaehwan

    2011-04-01

    Haptic is one of well-considered device which is suitable for demanding virtual reality applications such as medical equipment, mobile devices, the online marketing and so on. Nowadays, many of concepts for haptic devices have been suggested to meet the demand of industries. Cellulose has received much attention as an emerging smart material, named as electro-active paper (EAPap). The EAPap is attractive for mobile haptic devices due to its unique characteristics in terms of low actuation power, suitability for thin devices and transparency. In this paper, we suggest a new concept of haptic actuator with the use of cellulose EAPap. Its performance is evaluated depending on various actuation conditions. As a result, cellulose electrostatic force actuator shows a large output displacement and fast response, which is suitable for mobile haptic devices.

  16. Gigahertz flexible graphene transistors for microwave integrated circuits.

    Science.gov (United States)

    Yeh, Chao-Hui; Lain, Yi-Wei; Chiu, Yu-Chiao; Liao, Chen-Hung; Moyano, David Ricardo; Hsu, Shawn S H; Chiu, Po-Wen

    2014-08-26

    Flexible integrated circuits with complex functionalities are the missing link for the active development of wearable electronic devices. Here, we report a scalable approach to fabricate self-aligned graphene microwave transistors for the implementation of flexible low-noise amplifiers and frequency mixers, two fundamental building blocks of a wireless communication receiver. A devised AlOx T-gate structure is used to achieve an appreciable increase of device transconductance and a commensurate reduction of the associated parasitic resistance, thus yielding a remarkable extrinsic cutoff frequency of 32 GHz and a maximum oscillation frequency of 20 GHz; in both cases the operation frequency is an order of magnitude higher than previously reported. The two frequencies work at 22 and 13 GHz even when subjected to a strain of 2.5%. The gigahertz microwave integrated circuits demonstrated here pave the way for applications which require high flexibility and radio frequency operations.

  17. Measurements of the PLT and PDX device activation

    International Nuclear Information System (INIS)

    Stavely, J.; Barnes, C.W.; Chrien, R.E.; Strachan, J.D.

    1981-09-01

    Measurements of the activation levels around the PLT and PDX tokamaks have been made using a Ge(Li) gamma spectrometer and a Geiger counter. The activation results from radiation induced in the plasma by 14 MeV neutrons from the d(t,n)α fusion reaction, 14.7 MeV protons from the d( 3 He,p)α fusion reaction, 10 → 20 MeV hard x-rays from runaway electron induced bremmstrahlung, and 2.5 MeV neutrons from the d(d,n) 3 He fusion reaction. The magnitude of the activation is compared to that predicted for PDX on the basis of one-dimensional activation codes

  18. Use of activity theory-based need finding for biomedical device development.

    Science.gov (United States)

    Rismani, Shalaleh; Ratto, Matt; Machiel Van der Loos, H F

    2016-08-01

    Identifying the appropriate needs for biomedical device design is challenging, especially for less structured environments. The paper proposes an alternate need-finding method based on Cultural Historical Activity Theory and expanded to explicitly examine the role of devices within a socioeconomic system. This is compared to a conventional need-finding technique in a preliminary study with engineering student teams. The initial results show that the Activity Theory-based technique allows teams to gain deeper insights into their needs space.

  19. Microwave generation and complex microwave responsivity measurements on small Dayem bridges

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Sørensen, O; Mygind, Jesper

    1977-01-01

    Measurements of the active properties of a Dayem micro-bridge at X-band frequencies is described. The bridge was mounted in a microwave cavity designed to match the bridge properly and the microwave output from the cavity was detected using a sensitive X-band spectrometer. Microwave power...

  20. Soil Moisture Active Passive (SMAP) Microwave Radiometer Radio-Frequency Interference (RFI) Mitigation: Initial On-Orbit Results

    Science.gov (United States)

    Mohammed, Priscilla N.; Piepmeier, Jeffrey R.; Johnson, Joel T.; Aksoy, Mustafa; Bringer, Alexandra

    2015-01-01

    The Soil Moisture Active Passive (SMAP) mission, launched in January 2015, provides global measurements of soil moisture using a microwave radiometer. SMAPs radiometer passband lies within the passive frequency allocation. However, both unauthorized in-band transmitters as well as out-of-band emissions from transmitters operating at frequencies adjacent to this allocated spectrum have been documented as sources of radio frequency interference (RFI) to the L-band radiometers on SMOS and Aquarius. The spectral environment consists of high RFI levels as well as significant occurrences of low level RFI equivalent to 0.1 to 10 K. The SMAP ground processor reports the antenna temperature both before and after RFI mitigation is applied. The difference between these quantities represents the detected RFI level. The presentation will review the SMAP RFI detection and mitigation procedure and discuss early on-orbit RFI measurements from the SMAP radiometer. Assessments of global RFI properties and source types will be provided, as well as the implications of these results for SMAP soil moisture measurements.

  1. Degradation kinetics and mechanism of trace nitrobenzene by granular activated carbon enhanced microwave/hydrogen peroxide system.

    Science.gov (United States)

    Tan, Dina; Zeng, Honghu; Liu, Jie; Yu, Xiaozhang; Liang, Yanpeng; Lu, Lanjing

    2013-07-01

    The kinetics of the degradation of trace nitrobenzene (NB) by a granular activated carbon (GAC) enhanced microwave (MW)/hydrogen peroxide (H202) system was studied. Effects of pH, NB initial concentration and tert-butyl alcohol on the removal efficiency were examined. It was found that the reaction rate fits well to first-order reaction kinetics in the MW/GAC/H202 process. Moreover, GAC greatly enhanced the degradation rate of NB in water. Under a given condition (MW power 300 W, H202 dosage 10 mg/L, pH 6.85 and temperature (60 +/- 5)degrees C), the degradation rate of NB was 0.05214 min-1when 4 g/L GAC was added. In general, alkaline pH was better for NB degradation; however, the optimum pH was 8.0 in the tested pH value range of 4.0-12.0. At H202 dosage of 10 mg/L and GAC dosage of 4 g/L, the removal of NB was decreased with increasing initial concentrations of NB, indicating that a low initial concentration was beneficial for the degradation of NB. These results indicated that the MW/GAC/H202 process was effective for trace NB degradation in water. Gas chromatography-mass spectrometry analysis indicated that a hydroxyl radical addition reaction and dehydrogenation reaction enhanced NB degradation.

  2. Sea Surface Salinity and Wind Retrieval Algorithm Using Combined Passive-Active L-Band Microwave Data

    Science.gov (United States)

    Yueh, Simon H.; Chaubell, Mario J.

    2011-01-01

    Aquarius is a combined passive/active L-band microwave instrument developed to map the salinity field at the surface of the ocean from space. The data will support studies of the coupling between ocean circulation, the global water cycle, and climate. The primary science objective of this mission is to monitor the seasonal and interannual variation of the large scale features of the surface salinity field in the open ocean with a spatial resolution of 150 kilometers and a retrieval accuracy of 0.2 practical salinity units globally on a monthly basis. The measurement principle is based on the response of the L-band (1.413 gigahertz) sea surface brightness temperatures (T (sub B)) to sea surface salinity. To achieve the required 0.2 practical salinity units accuracy, the impact of sea surface roughness (e.g. wind-generated ripples and waves) along with several factors on the observed brightness temperature has to be corrected to better than a few tenths of a degree Kelvin. To the end, Aquarius includes a scatterometer to help correct for this surface roughness effect.

  3. Human Activity Recognition in a Car with Embedded Devices

    Directory of Open Access Journals (Sweden)

    Danilo Burbano

    2015-11-01

    Full Text Available Detection and prediction of drowsiness is key for the implementation of intelligent vehicles aimed to prevent highway crashes. There are several approaches for such solution. In thispaper the computer vision approach will be analysed, where embedded devices (e.g.videocameras are used along with machine learning and pattern recognition techniques for implementing suitable solutions for detecting driver fatigue. Most of the research in computer vision systems focused on the analysis of blinks, this is a notable solution when it is combined with additional patterns like yawing or head motion for the recognition of drowsiness. The first step in this approach is the face recognition, where AdaBoost algorithm shows accurate results for the feature extraction, whereas regarding the detection of drowsiness the data-driven classifiers such as Support Vector Machine (SVM yields remarkable results. One underlying component for implementing a computer vision technology for detection of drowsiness is a database of spontaneous images from the Facial Action Coding System (FACS, where the classifier can be trained accordingly. This paper introduces a straightforward prototype for detection of drowsiness, where the Viola-Jones method is used for face recognition and cascade classifier is used for the detection of a contiguous sequence of eyes closed, which a reconsidered as drowsiness.

  4. Forensic devices for activism: Metadata tracking and public proof

    Directory of Open Access Journals (Sweden)

    Lonneke van der Velden

    2015-10-01

    Full Text Available The central topic of this paper is a mobile phone application, ‘InformaCam’, which turns metadata from a surveillance risk into a method for the production of public proof. InformaCam allows one to manage and delete metadata from images and videos in order to diminish surveillance risks related to online tracking. Furthermore, it structures and stores the metadata in such a way that the documentary material becomes better accommodated to evidentiary settings, if needed. In this paper I propose InformaCam should be interpreted as a ‘forensic device’. By using the conceptualization of forensics and work on socio-technical devices the paper discusses how InformaCam, through a range of interventions, rearranges metadata into a technology of evidence. InformaCam explicitly recognizes mobile phones as context aware, uses their sensors, and structures metadata in order to facilitate data analysis after images are captured. Through these modifications it invents a form of ‘sensory data forensics'. By treating data in this particular way, surveillance resistance does more than seeking awareness. It becomes engaged with investigatory practices. Considering the extent by which states conduct metadata surveillance, the project can be seen as a timely response to the unequal distribution of power over data.

  5. Determination of Activated Carbon Residual Life using a Microwave Cavity Resonator

    International Nuclear Information System (INIS)

    Mason, A; Wylie, S; Shaw, A; Al-Shamma'a, A I; Thomas, A; Keele, H

    2011-01-01

    This paper presents the continuation of work conducted jointly between Dstl and LJMU. This unique body of work has been, largely, concerned with detecting the residual life of high performance filter materials using electromagnetic (EM) waves within a resonant cavity. Past work has considered both HEPA [1] and ASZM-TEDA[2] activated carbon filter materials. This paper continues the later work, considering the response of ASZM-TEDA activated carbon through the co-ageing of two distinct batches of the material. The paper briefly introduces activated carbon, discusses theory relevant to the work and the methodology used for investigation. A comprehensive set of results is included which seek to validate this technique for determining the residual lifespan of activated carbon.

  6. Microwave-Assisted Synthesis of Bio-Active Heterocycles and Fine Chemicals in Aqueous Media

    Science.gov (United States)

    Human health, especially in the aging population, mostly depends on various medicines, and researchers are combating against emerging diseases by new drug discovery. Heterocyclic compounds hold a special place among pharmaceutically active natural products as well as synthetic co...

  7. Microwave-assisted synthesis of bio-active heterocycles in aqueous media

    KAUST Repository

    Polshettiwar, Vivek; Varma, Rajender S.

    2010-01-01

    Synthesis of bio-active heterocycles and fine chemicals in aqueous media are one of the best solutions for the development of green and sustainable protocols. To illustrate the advantages of aqueous MW chemistry in heterocycle synthesis

  8. Modern devices of optimum filtration for the active radar system

    OpenAIRE

    V. E. Bychkov; O. D. Mrachkovskiy; V. I. Pravda

    2006-01-01

    The principle of construction the matched filter and correlator, for the active radar system operating with a broadband noise signal is esteemed. The example of construction a сhan-nel of processing on the basis of microcircuits of a programmed logic (PLD) is shown

  9. Device for determining element contents of lignite mass flows by activation analysis

    International Nuclear Information System (INIS)

    Goeldner, R.; Maul, E.; Rose, W.; Wagner, D.

    1987-01-01

    A simple device is presented, apt for continuous operation, to determine the element contents of bulk goods of flowable materials with a suitable granularity, in particular of lignite mass flows to assess the coal quality. Several kilograms of samples can be reproducibly dosed and homogeneously activated by a device consisting of a shielding container with activation chamber and radiation source, a measuring unit with detectors, and a source container, and characterized by a blade wheel in the activation chamber which causes the dosing and homogeneous activation of the sample

  10. Tunable Multiband Microwave Photonic Filters

    Directory of Open Access Journals (Sweden)

    Mable P. Fok

    2017-11-01

    Full Text Available The increasing demand for multifunctional devices, the use of cognitive wireless technology to solve the frequency resource shortage problem, as well as the capabilities and operational flexibility necessary to meet ever-changing environment result in an urgent need of multiband wireless communications. Spectral filter is an essential part of any communication systems, and in the case of multiband wireless communications, tunable multiband RF filters are required for channel selection, noise/interference removal, and RF signal processing. Unfortunately, it is difficult for RF electronics to achieve both tunable and multiband spectral filtering. Recent advancements of microwave photonics have proven itself to be a promising candidate to solve various challenges in RF electronics including spectral filtering, however, the development of multiband microwave photonic filtering still faces lots of difficulties, due to the limited scalability and tunability of existing microwave photonic schemes. In this review paper, we first discuss the challenges that were facing by multiband microwave photonic filter, then we review recent techniques that have been developed to tackle the challenge and lead to promising developments of tunable microwave photonic multiband filters. The successful design and implementation of tunable microwave photonic multiband filter facilitate the vision of dynamic multiband wireless communications and radio frequency signal processing for commercial, defense, and civilian applications.

  11. Microwave Assisted Synthesis of Some New Heterocyclic Spiro-Derivatives with Potential Antimicrobial and Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Mohamed Mohamed Youssef

    2010-12-01

    Full Text Available Homophthalic anhydride reacts with different aromatic amines to produce N-substituted homophthalimides. Bromination of the latter produces 4,4-dibromo-homophthalimide derivatives that can be used as precursors for spiro-derivatives. The dibromo derivatives react with different binucleophilic reagents to produce several spiro-isoquinoline derivatives. Reaction of the dibromo derivatives with malononitrile produces dicyanomethylene derivatives which react with different binucleophiles to produce new spiro-derivatives. Structures of the newly synthesized compounds are proved using spectroscopic methods such as IR, 1H-NMR and 13C-NMR. The newly synthesized compounds were tested for their antimicrobial and antioxidant activities, showing weak or no antimicrobial activity. On the other hand select compounds showed promising antioxidant activities.

  12. Effect of microwave drying and oven drying on the water activity, color, phenolic compounds content and antioxidant activity of coconut husk (Cocos nucifera L.).

    Science.gov (United States)

    Valadez-Carmona, Lourdes; Cortez-García, Rosa María; Plazola-Jacinto, Carla Patricia; Necoechea-Mondragón, Hugo; Ortiz-Moreno, Alicia

    2016-09-01

    The coconut ( Cocos nucifera L.) husk is basically composed by fiber and pith material and remained under-utilized. This is an important source of phenolic compounds that could be used as functional ingredients. The aim of this study was to determine the effect of: oven-drying (OD) and microwave drying (MD), on the water activity, color, phenolic compound content and antioxidant activity of coconut husk. The OD was performed at 60 °C for 12 h and MD was performed at 900 W for 10 min. The total phenolic content (TPC) in fresh coconut husk was 64.2 mg GAE/g dry wt and significant higher than observed after OD and MD of 35.8 and 45.5 mg GAE/g dry wt, respectively. Ten phenols were identified in fresh and dehydrated coconut husks. The husk MD showed an increase in the content of gallic, 4-hydroxybenzoic, ferulic and syringic acids and epicatechin compared with the fresh; while coconut husk OD and MD, showed a decrease in the content of vanillic acid, vanillin, catequin and kaempferol. The antioxidant activity decreased after both OD and MD. However, MD resulted in a better antioxidant activity in husk than OD. MD of husk resulted into better retention of preserved color, TPC and TFC than OD.

  13. Re-Active Passive devices for control of noise transmission through a panel

    Science.gov (United States)

    Carneal, James P.; Giovanardi, Marco; Fuller, Chris R.; Palumbo, Dan

    2008-01-01

    Re-Active Passive devices have been developed to control low-frequency (transmission through a panel. These devices use a combination of active, re-active, and passive technologies packaged into a single unit to control a broad frequency range utilizing the strength of each technology over its best suited frequency range. The Re-Active Passive device uses passive constrained layer damping to cover relatively high-frequency range (>150 Hz), reactive distributed vibration absorber to cover the medium-frequency range (50-200 Hz), and active control for controlling low frequencies (transmission through a panel mounted in the Transmission Loss Test Facility at Virginia Tech. Experimental results are presented for the bare panel, and combinations of passive treatment, reactive treatment, and active control. Results indicate that three Re-Active Passive devices were able to increase the overall broadband (15-1000 Hz) transmission loss by 9.4 dB. These three devices added a total of 285 g to the panel mass of 6.0 kg, or approximately 5%, not including control electronics.

  14. Irradiation, microwave and alternative energy-based treatments for low water activity foods

    Science.gov (United States)

    There is an increasing recognition of low water activity foods as vectors for human pathogens. Partially or fully dried agricultural commodities, along with modern formulated dried food products, are complex, and designed to meet a variety of nutritional, sensory, and market-oriented goal. This comp...

  15. Microfabricated Low-Loss Microwave Switch Integration Technology, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Nuvotronics has developed and optimized the PolyStrataTM process for the fabrication of intricate microwave and millimeter-wave devices. These devices have primarily...

  16. Microwave assisted facile synthesis of reduced graphene oxide-silver (RGO-Ag) nanocomposite and their application as active SERS substrate

    International Nuclear Information System (INIS)

    Wadhwa, Heena; Kumar, Devender; Mahendia, Suman; Kumar, Shyam

    2017-01-01

    The present paper represents the facile and rapid synthesis of reduced graphene oxide-silver (RGO-Ag) nanocomposite with the help of microwave irradiation. The graphene oxide (GO) solution has been prepared in bulk using Hummer's method followed by microwave assisted in-situ reduction of GO and silver nitrate (AgNO_3) by hydrazine hydrate in a short spam of 5 min. The prepared nanocomposite has been characterized using Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD) Scanning Electron Microscopy (SEM) and UV–Visible spectroscopy. TEM analysis shows that Ag nanoparticles with average size 32 nm are uniformly entangled with in RGO layers. The UV–Visible absorption spectrum of nanocomposite depicts the reduction of GO to RGO along with the formation of Ag nanoparticles with the presence of characteristic surface Plasmon resonance (SPR) peak of Ag nanoparticles at 422 nm. The performance of prepared nanocomposite has been tested as the active Surface Enhanced Raman Scattering (SERS) substrate for Rhodamine 6G with detection limit 0.1 μM. - Highlights: • The RGO and RGO-Ag nanocomposite were synthesized with microwave irradiation. • Ag nanoparticles of average size 32 nm are uniformly entangled within RGO layers. • RGO itself is a florescence quencher with SERS detection limit 1 μM for R6G. • RGO-Ag nanocomposite show good SERS activity for R6G with detection limit 0.1 μM.

  17. Microwave assisted facile synthesis of reduced graphene oxide-silver (RGO-Ag) nanocomposite and their application as active SERS substrate

    Energy Technology Data Exchange (ETDEWEB)

    Wadhwa, Heena, E-mail: heenawadhwa1988@gmail.com; Kumar, Devender, E-mail: devkumsaroha@kuk.ac.in; Mahendia, Suman, E-mail: mahendia@gmail.com; Kumar, Shyam, E-mail: profshyam@gmail.com

    2017-06-15

    The present paper represents the facile and rapid synthesis of reduced graphene oxide-silver (RGO-Ag) nanocomposite with the help of microwave irradiation. The graphene oxide (GO) solution has been prepared in bulk using Hummer's method followed by microwave assisted in-situ reduction of GO and silver nitrate (AgNO{sub 3}) by hydrazine hydrate in a short spam of 5 min. The prepared nanocomposite has been characterized using Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD) Scanning Electron Microscopy (SEM) and UV–Visible spectroscopy. TEM analysis shows that Ag nanoparticles with average size 32 nm are uniformly entangled with in RGO layers. The UV–Visible absorption spectrum of nanocomposite depicts the reduction of GO to RGO along with the formation of Ag nanoparticles with the presence of characteristic surface Plasmon resonance (SPR) peak of Ag nanoparticles at 422 nm. The performance of prepared nanocomposite has been tested as the active Surface Enhanced Raman Scattering (SERS) substrate for Rhodamine 6G with detection limit 0.1 μM. - Highlights: • The RGO and RGO-Ag nanocomposite were synthesized with microwave irradiation. • Ag nanoparticles of average size 32 nm are uniformly entangled within RGO layers. • RGO itself is a florescence quencher with SERS detection limit 1 μM for R6G. • RGO-Ag nanocomposite show good SERS activity for R6G with detection limit 0.1 μM.

  18. Device Simulation of Monolithic Active Pixel Sensors: Radiation Damage Effects

    International Nuclear Information System (INIS)

    Fourches, N.T.

    2009-01-01

    Vertexing for the future International Linear Collider represents a challenging goal because of the high spatial resolution required with low material budget and high ionizing radiation tolerance. CMOS Monolithic Active Pixel Sensors (MAPS) represent a good potential solution for this purpose. Up to now many MAPS sensors have been developed. They are based on various architectures and manufactured in different processes. However, up so far, the sensor diode has not been the subject of extensive modelization and simulation. Published simulation studies of sensor-signal formation have been less numerous than measurements on real sensors. This is a cause for concern because such sensor is physically based on the partially depleted diode, in the vicinity of which the electric field collects the minority carriers generated by an incident MIP (minimum ionizing particle). Although the microscopic mechanisms are well known and modelled, the global physical mechanisms for signal formation are not very rigorously established. This is partly due to the presence of a predominant diffusion component in the charge transport. We present here simulations mainly based on the S-PISCES code, in which physical mechanisms affecting transport are taken into account. Diffusion, influence of residual carrier concentration due to the doping level in the sensitive volume, and more importantly charge trapping due to deep levels in the active (detecting) layer are studied together with geometric aspects. The effect of neutron irradiation is studied to assess the effects of deep traps. A comparison with available experimental data, obtained on processed MAPS before or after neutron irradiation will be introduced. Simulated reconstruction of the Minimum Ionizing Particle (MIP) point of impact in two dimensions is also investigated. For further steps, guidelines for process choices of next Monolithic Active Pixel Sensors are introduced. (authors)

  19. Ionic Liquids in Electro-active Devices (ILED)

    Science.gov (United States)

    2013-12-12

    near a charged wall can be modeled by Poisson- Nernst -Planck (PNP) equations , Poisson-Boltzmann (PB) equations , and Gouy-Chapman-Stern (GCS) model...actuators can be calculated from the bending curvature к and the Young’s moduli of the ionic polymer layer Yi and the Au layer Ym by the equation below...Arrhenius equation exp a E p p RT (1) wherein p and aE are the conducting ion concentration as T and the activation energy for conducting

  20. Microwave assistant synthesis, crystal structure and biological activity of a 1,2,4-triazole compound

    International Nuclear Information System (INIS)

    Ke, W.; Sun, N.B.

    2013-01-01

    The title compound (C/sub 17/H/sub 14/F/sub 2/N/sub 4/SO) were synthesized and recrystallized from CH/sub 3/CN. The compound was characterized by 1h-nmr, ftir, ms, hrms and x-ray diffraction. the compound crystallized in the monoclinic space group c2/c with a = 27.532(6), b 8.9596(18), c 14.609(3) alpha = 90, beta = 112.59(3), lambda =90 degree, gamma = 3327.1(12) alpha 3, z = 8 and r = 0.0327 for 2596 observed reflections with 1 > 2 (i). x-ray analysis reveals that not only intermolecular N-H-N interactions, but also C-H Pie stacking interactions exist in the adjacent molecules. The biological activities results showed that it exhibited significant herbicidal activity towards brassica napus. (author)

  1. A microwave-augmented plasma torch module

    International Nuclear Information System (INIS)

    Kuo, S P; Bivolaru, Daniel; Williams, Skip; Carter, Campbell D

    2006-01-01

    A new plasma torch device which combines arc and microwave discharges to enhance the size and enthalpy of the plasma torch is described. A cylindrical-shaped plasma torch module is integrated into a tapered rectangular cavity to form a microwave adaptor at one end, which couples the microwave power injected into the cavity from the other end to the arc plasma generated by the torch module. A theoretical study of the microwave coupling from the cavity to the plasma torch, as the load, is presented. The numerical results indicate that the microwave power coupling efficiency exceeds 80%. Operational tests of the device indicate that the microwave power is coupled to the plasma torch and that the arc discharge power is increased. The addition of microwave energy enhances the height, volume and enthalpy of the plasma torch when the torch operates at a low airflow rate, and even when the flow speed is supersonic, a noticeable microwave effect on the plasma torch is observed. In addition, the present design allows the torch to be operated as both a fuel injector and igniter. Ignition of ethylene fuel injected through the centre of a tungsten carbide tube acting as the central electrode is demonstrated

  2. Microwave materials for wireless applications

    CERN Document Server

    Cruickshank, David B

    2011-01-01

    This practical resource offers you an in-depth, up-to-date understanding of the use of microwave magnetic materials for cutting-edge wireless applications. The book discusses device applications used in wireless infrastructure base stations, point-to-point radio links, and a range of more specialized microwave systems. You find detailed discussions on the attributes of each family of magnetic materials with respect to specific wireless applications. Moreover, the book addresses two of the hottest topics in the field today - insertion loss and intermodulation. This comprehensive reference also

  3. Atmospheric pressure microwave plasma system with ring waveguide

    International Nuclear Information System (INIS)

    Liu Liang; Zhang Guixin; Zhu Zhijie; Luo Chengmu

    2007-01-01

    Some scientists used waveguide as the cavity to produce a plasma jet, while large volume microwave plasma was relatively hard to get in atmospheric pressure. However, a few research institutes have already developed devices to generate large volume of atmospheric pressure microwave plasma, such as CYRANNUS and SLAN series, which can be widely applied. In this paper, present a microwave plasma system with ring waveguide to excite large volume of atmospheric pressure microwave plasma, plot curves on theoretical disruption electric field of some working gases, emulate the cavity through software, measure the power density to validate and show the appearance of microwave plasma. At present, large volume of argon and helium plasma have already been generated steadily by atmospheric pressure microwave plasma system. This research can build a theoretical basis of microwave plasma excitation under atmospheric pressure and will be useful in study of the device. (authors)

  4. Effects of a Physical Education Supportive Curriculum and Technological Devices on Physical Activity

    Science.gov (United States)

    Clapham, Emily Dean; Sullivan, Eileen C.; Ciccomascolo, Lori E.

    2015-01-01

    The purpose of this study was to examine the effects of a physical education supportive curriculum and technological devices, heart rate monitor (HRM) and pedometer (PED), on physical activity. A single-subject ABAB research design was used to examine amount and level of participation in physical activity among 106 suburban fourth and fifth…

  5. Linear theory of microwave absortion in fusion plasmas. A study of the electron cyclotron resonance and its particularization to a helical axis device for magnetic confinement

    International Nuclear Information System (INIS)

    Castejon M, F.

    1989-01-01

    The study of the Linear Theory microwave propagation and absorption in the the frequency range of electron cyclotron resonance, in a magnetized plasma, is developed. This study is particularized to the flexible heliac TJ-II, whose main characteristics are dsetailed in a memory chapter, as an interesting case example for its peculiar magnetic configuration. As a preliminary phase, a cold plasma model is useds to analyze the resonance accessibility and the approximated density limits which will be obtainable in each electron cyclotron resonance harmonic. This analysis was used to find the suitable positions for the microwave injection in TJ-II. An analytical weakly relativistic model for the dielectric tensor is developed, valid for oblique propagation, that takes account of the effect of superthermal electrons. Second order Larmor radius effects are included, so that the Quasi-Electrostatic branch of X mode can be studied. A numerical study is then presented on the absorption properties of TJ-II. Since the TJ-II geometry is complex and its magnetic field distribution is very different from that of a tokamak, ray tracing calculations are necessary to consider refraction effects. The ray tracing codse RAYS, developed in the Oak Ridge National Laboratory (U.S.A.), was take and adapted to the helical magnetic configuration of the TJ-II. The absorption model described above was then included in RAYS. For completeness, an introduction to the Quasi Linear Theory, natural prolongation of this work, is included at the end of the memory, ands the effects of taking into account the quasi linear evolution of the distribution function are described. (Author)

  6. Re-active Passive (RAP) Devices for Control of Noise Transmission through a Panel

    Science.gov (United States)

    Carneal, James P.; Giovanardi, Marco; Fuller, Chris R.; Palumbo, Daniel L.

    2008-01-01

    Re-Active Passive (RAP) devices have been developed to control low frequency (transmission through a panel. These devices use a combination of active, re-active, and passive technologies packaged into a single unit to control a broad frequency range utilizing the strength of each technology over its best suited frequency range. The RAP device uses passive constrained layer damping to cover the relatively high frequency range (>200 Hz), reactive distributed vibration absorber) to cover the medium frequency range (75 to 250 Hz), and active control for controlling low frequencies (transmission through a panel mounted in a transmission loss test facility. Experimental results are presented for the bare panel, and combinations of passive treatment, reactive treatment, and active control. Results indicate that three RAP devices were able to increase the overall broadband (15-1000 Hz) transmission loss by 9.4 dB. These three devices added a total of 285 grams to the panel mass of 6.0 kg, or approximately 5%, not including control electronics.

  7. Light-activated resistance switching in SiOx RRAM devices

    Science.gov (United States)

    Mehonic, A.; Gerard, T.; Kenyon, A. J.

    2017-12-01

    We report a study of light-activated resistance switching in silicon oxide (SiOx) resistive random access memory (RRAM) devices. Our devices had an indium tin oxide/SiOx/p-Si Metal/Oxide/Semiconductor structure, with resistance switching taking place in a 35 nm thick SiOx layer. The optical activity of the devices was investigated by characterising them in a range of voltage and light conditions. Devices respond to illumination at wavelengths in the range of 410-650 nm but are unresponsive at 1152 nm, suggesting that photons are absorbed by the bottom p-type silicon electrode and that generation of free carriers underpins optical activity. Applied light causes charging of devices in the high resistance state (HRS), photocurrent in the low resistance state (LRS), and lowering of the set voltage (required to go from the HRS to LRS) and can be used in conjunction with a voltage bias to trigger switching from the HRS to the LRS. We demonstrate negative correlation between set voltage and applied laser power using a 632.8 nm laser source. We propose that, under illumination, increased electron injection and hence a higher rate of creation of Frenkel pairs in the oxide—precursors for the formation of conductive oxygen vacancy filaments—reduce switching voltages. Our results open up the possibility of light-triggered RRAM devices.

  8. Electromagnetic modeling and characterization of an optically-controlled microwave phase shifterin GaAs integrated technology

    OpenAIRE

    Tripon-Canseliet, C.; Faci, S.; Deshours, F.; Algani, C.; Alquié, G.; Formont, S.; Chazelas, J.

    2005-01-01

    A state of the art of the modeling of microwave photoswitching devices is exposed. A new 3 D electromagnetic modeling allows the design of an optically-controlled microwave phase shifter microwave starting from the traditional circuit of a microwave photoswitch. Measurements of the parameters S of this optically-controlled microwave phase shifter attests the function of this circuit by optical way and highlights the interest of the integration of this new type of microwave phase shifters in ...

  9. Microwave assisted solid phase extraction for separation preconcentration sulfamethoxazole in wastewater using tyre based activated carbon as solid phase material prior to spectrophotometric determination

    Science.gov (United States)

    Mogolodi Dimpe, K.; Mpupa, Anele; Nomngongo, Philiswa N.

    2018-01-01

    This work was chiefly encouraged by the continuous consumption of antibiotics which eventually pose harmful effects on animals and human beings when present in water systems. In this study, the activated carbon (AC) was used as a solid phase material for the removal of sulfamethoxazole (SMX) in wastewater samples. The microwave assisted solid phase extraction (MASPE) as a sample extraction method was employed to better extract SMX in water samples and finally the analysis of SMX was done by the UV-Vis spectrophotometer. The microwave assisted solid phase extraction method was optimized using a two-level fractional factorial design by evaluating parameters such as pH, mass of adsorbent (MA), extraction time (ET), eluent ratio (ER) and microwave power (MP). Under optimized conditions, the limit of detection (LOD) and limit of quantification (LOQ) were 0.5 μg L- 1 and 1.7 μg L- 1, respectively, and intraday and interday precision expressed in terms of relative standard deviation were > 6%.The maximum adsorption capacity was 138 mg g- 1 for SMX and the adsorbent could be reused eight times. Lastly, the MASPE method was applied for the removal of SMX in wastewater samples collected from a domestic wastewater treatment plant (WWTP) and river water.

  10. Dynamic of ozone formation in nanosecond microwave discharges

    International Nuclear Information System (INIS)

    Akhmedzhanov, R.A.; Vikharev, A.L.; Gorbachev, A.M.

    1995-01-01

    Nanosecond gas discharges are efficient sources of chemically active plasma. Studies of the nanosecond microwave discharge are interesting for remote modification of the chemical composition of the atmosphere in term of its purification, for diagnostics of impurities and ozone replenishment in the regions of local open-quotes ozone holesclose quotes. In this connection a study of plasma chemical processes in such a discharge seems appropriate, as well as modeling of ecological consequences of the effect of powerful microwave radiation on the atmosphere. The present paper contains generalized results of studying the process of ozone formation in a pulse-periodic freely localized nanosecond microwave discharge. The experiments were performed in a wide range of parameters: microwave radiation wavelength λ = 0.8 and 3cm, pulse duration τ = 6 and 500ns, pulse power P = 50kW and 20MW, pulse repetition rate F = 1-10 3 Hz. The working gases were air and oxygen under pressure P = 10-100Torr. As a source of the microwave radiation a pulse magnetron was used with a device for pulse compression based on the waveguide resonator, and a relativistic microwave generator. The discharge was produced in the focus of the parabolic mirror and had the form of homogeneous cylinder. The plasma chemical processes were studied in two cases. The discharge was created either in the quartz tube placed along the focal line of the mirror or in the free air. Dynamics of formation of ozone and nitrogen oxides in the discharge was studied by means of absorption spectroscopy in the regime of accumulation of the products of chemical reactions (in a closed volume) and their diffusion spreading

  11. Features of Microwave Radiation and Magnetographic Characteristics of Solar Active Region NOAA 12242 Before the X1.8 Flare on December 20, 2014

    Science.gov (United States)

    Abramov-Maximov, V. E.; Borovik, V. N.; Opeikina, L. V.; Tlatov, A. G.; Yasnov, L. V.

    2017-12-01

    This paper continues the cycle of authors' works on the detection of precursors of large flares (M5 and higher classes) in active regions (ARs) of the Sun by their microwave radiation and magnetographic characteristics. Generalization of the detected precursors of strong flares can be used to develop methods for their prediction. This paper presents an analysis of the development of NOAA AR 12242, in which an X1.8 flare occurred on December 20, 2014. The analysis is based on regular multiazimuth and multiwavelength observations with the RATAN-600 radio telescope in the range 1.65-10 cm with intensity and circular polarization analysis and data from the Solar Dynamics Observatory (SDO). It was found that a new component appeared in the AR microwave radiation two days before the X-flare. It became dominant in the AR the day before the flare and significantly decreased after the flare. The use of multiazimuth observations from RATAN-600 and observations at 1.76 cm from the Nobeyama Radioheliograph made it possible to identify the radio source that appeared before the X-flare with the site of the closest convergence of opposite polarity fields near the neutral line in the AR. It was established that the X-flare occurred 20 h after the total gradient of the magnetic field of the entire region calculated from SDO/HMI data reached its maximum value. Analysis of the evolution of the microwave source that appeared before the X-flare in AR 12242 and comparison of its parameters with the parameters of other components of the AR microwave radiation showed that the new source can be classified as neutral line associated sources (NLSs), which were repeatedly detected by the RATAN-600 and other radio telescopes 1-3 days before the large flares.

  12. Urchin-like CdS/ZrO2 nanocomposite prepared by microwave-assisted hydrothermal combined with ion-exchange and its multimode photocatalytic activity

    Science.gov (United States)

    Li, Li; Wang, Lili; Zhang, Wenzhi; Zhang, Xiuli; Chen, Xi; Dong, Xue

    2014-12-01

    A series of urchin-like CdS/ZrO2 nanocomposites with different mole ratios of Cd/Zr were prepared by a two-step method combining the microwave-assisted hydrothermal and ion exchange methods. The products were characterized by X-ray diffraction, ultraviolet-visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and N2 adsorption-desorption measurements. The results of the study revealed that the CdS/ZrO2 nanocomposites had mixed phases of tetragonal ZrO2 and hexagonal CdS. Moreover, the samples prepared by the microwave-assisted hydrothermal method possessed the urchin-like structure with a surface composed of protrude-like nanoparticles in large quantities. The absorption in the visible region changed slightly with increasing mole ratio of Cd/Zr. Moreover, compared to the nanocomposites prepared by the conventional heating, the nanocomposites prepared by the microwave-assisted hydrothermal synthesis showed significantly different Brunauer-Emmett-Teller values, and the urchin-like CdS/ZrO2 structures were obtained. The photocatalytic degradation of methyl orange under ultraviolet (UV) light irradiation indicated that the photocatalytic activity of the CdS/ZrO2 nanocomposite with CdS/ZrO2 molar ratio of 30 % was higher than those of CdS, ZrO2, and other different ratios of CdS/ZrO2 nanocomposites. Moreover, under UV light, visible light, and microwave-assisted multimode photocatalytic degradation, the urchin-like CdS/ZrO2 nanocomposites significantly affected the photodegradation of various dyes. To understand the possible reaction mechanism of the photocatalysis by the CdS/ZrO2 nanocomposites, a series of controlled experiments were performed, and the stability and reusability of the CdS/ZrO2 nanocomposites were further investigated by the photocatalytic reaction.

  13. Urchin-like CdS/ZrO2 nanocomposite prepared by microwave-assisted hydrothermal combined with ion-exchange and its multimode photocatalytic activity

    International Nuclear Information System (INIS)

    Li, Li; Wang, Lili; Zhang, Wenzhi; Zhang, Xiuli; Chen, Xi; Dong, Xue

    2014-01-01

    A series of urchin-like CdS/ZrO 2 nanocomposites with different mole ratios of Cd/Zr were prepared by a two-step method combining the microwave-assisted hydrothermal and ion exchange methods. The products were characterized by X-ray diffraction, ultraviolet–visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and N 2 adsorption–desorption measurements. The results of the study revealed that the CdS/ZrO 2 nanocomposites had mixed phases of tetragonal ZrO 2 and hexagonal CdS. Moreover, the samples prepared by the microwave-assisted hydrothermal method possessed the urchin-like structure with a surface composed of protrude-like nanoparticles in large quantities. The absorption in the visible region changed slightly with increasing mole ratio of Cd/Zr. Moreover, compared to the nanocomposites prepared by the conventional heating, the nanocomposites prepared by the microwave-assisted hydrothermal synthesis showed significantly different Brunauer–Emmett–Teller values, and the urchin-like CdS/ZrO 2 structures were obtained. The photocatalytic degradation of methyl orange under ultraviolet (UV) light irradiation indicated that the photocatalytic activity of the CdS/ZrO 2 nanocomposite with CdS/ZrO 2 molar ratio of 30 % was higher than those of CdS, ZrO 2 , and other different ratios of CdS/ZrO 2 nanocomposites. Moreover, under UV light, visible light, and microwave-assisted multimode photocatalytic degradation, the urchin-like CdS/ZrO 2 nanocomposites significantly affected the photodegradation of various dyes. To understand the possible reaction mechanism of the photocatalysis by the CdS/ZrO 2 nanocomposites, a series of controlled experiments were performed, and the stability and reusability of the CdS/ZrO 2 nanocomposites were further investigated by the photocatalytic reaction

  14. A Robust and Device-Free System for the Recognition and Classification of Elderly Activities.

    Science.gov (United States)

    Li, Fangmin; Al-Qaness, Mohammed Abdulaziz Aide; Zhang, Yong; Zhao, Bihai; Luan, Xidao

    2016-12-01

    Human activity recognition, tracking and classification is an essential trend in assisted living systems that can help support elderly people with their daily activities. Traditional activity recognition approaches depend on vision-based or sensor-based techniques. Nowadays, a novel promising technique has obtained more attention, namely device-free human activity recognition that neither requires the target object to wear or carry a device nor install cameras in a perceived area. The device-free technique for activity recognition uses only the signals of common wireless local area network (WLAN) devices available everywhere. In this paper, we present a novel elderly activities recognition system by leveraging the fluctuation of the wireless signals caused by human motion. We present an efficient method to select the correct data from the Channel State Information (CSI) streams that were neglected in previous approaches. We apply a Principle Component Analysis method that exposes the useful information from raw CSI. Thereafter, Forest Decision (FD) is adopted to classify the proposed activities and has gained a high accuracy rate. Extensive experiments have been conducted in an indoor environment to test the feasibility of the proposed system with a total of five volunteer users. The evaluation shows that the proposed system is applicable and robust to electromagnetic noise.

  15. Advances in microwaves 8

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 8 covers the developments in the study of microwaves. The book discusses the circuit forms for microwave integrated circuits; the analysis of microstrip transmission lines; and the use of lumped elements in microwave integrated circuits. The text also describes the microwave properties of ferrimagnetic materials, as well as their interaction with electromagnetic waves propagating in bounded waveguiding structures. The integration techniques useful at high frequencies; material technology for microwave integrated circuits; specific requirements on technology for d

  16. Microwave power engineering applications

    CERN Document Server

    Okress, Ernest C

    2013-01-01

    Microwave Power Engineering, Volume 2: Applications introduces the electronics technology of microwave power and its applications. This technology emphasizes microwave electronics for direct power utilization and transmission purposes. This volume presents the accomplishments with respect to components, systems, and applications and their prevailing limitations in the light of knowledge of the microwave power technology. The applications discussed include the microwave heating and other processes of materials, which utilize the magnetron predominantly. Other applications include microwave ioni

  17. Microwave-assisted synthesis, molecular docking and antitubercular activity of 1,2,3,4-tetrahydropyrimidine-5-carbonitrile derivatives

    Czech Academy of Sciences Publication Activity Database

    Mohan, S. B.; Kumar, B. V. V. R.; Dinda, S. C.; Naik, D.; Seenivasan, S. P.; Kumar, V.; Rana, D. N.; Brahmkshatriya, Pathik

    2012-01-01

    Roč. 22, č. 24 (2012), s. 7539-7542 ISSN 0960-894X Institutional research plan: CEZ:AV0Z40550506 Keywords : antitubercular * binding interactions * luciferase reporter phage (LRP) assay * microwave-assisted * molecular docking Subject RIV: CC - Organic Chemistry Impact factor: 2.338, year: 2012

  18. Use of a Mobile Device Simulation as a Preclass Active Learning Exercise.

    Science.gov (United States)

    Keegan, Robert D; Oliver, M Cecile; Stanfill, Teresa J; Stevens, Kevin V; Brown, Gary R; Ebinger, Michael; Gay, John M

    2016-01-01

    Research shows that preclass activities introducing new material can increase student performance. In an effort to engage students in an active learning, preclass activity, the authors developed a mobile application. Eighty-four nursing students were assigned a preclass reading exercise, whereas 32 students completed the preclass simulation scenario on their mobile device. All students completed the same electronic fetal monitoring (EFM) quiz 1 week following the lecture. The effects of reading or simulation on student quiz performance was evaluated with a student's paired t test, using an alpha of .05. Students completing the preclass simulation scored higher on the EFM quiz, compared with students assigned the preclass reading (85% versus 70% correct answers, p = .01). Student survey data indicated that the mobile device simulation was perceived as an engaging and desirable instructional tool. Nursing students completing the mobile device EFM preclass simulation outperformed the students who were given the traditional reading assignment. Copyright 2016, SLACK Incorporated.

  19. Enhanced adsorption of chromium onto activated carbon by microwave-assisted H{sub 3}PO{sub 4} mixed with Fe/Al/Mn activation

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yuanyuan [Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Yue, Qinyan, E-mail: qyyue58@aliyun.com [Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Mao, Yanpeng [School of Energy and Power Engineering, Shandong University, Jinan 250100 (China); Gao, Baoyu; Gao, Yuan; Huang, Lihui [Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China)

    2014-01-30

    Highlights: • FeCl{sub 3}, AlCl{sub 3} and MnCl{sub 2} were used as the assisted activator to produce carbons. • Doping with MnCl{sub 2} was favorable for the enlargement of activated carbon. • The assisted activator had good performance for holding more fixed carbon. • The maximum adsorption capacities followed the order of AC-Fe > AC-Al > AC-Mn > AC. • The XPS analysis was used to confirm the adsorption/transformation mechanism. -- Abstract: FeCl{sub 3}, AlCl{sub 3} and MnCl{sub 2} were used as the assisted activation agent in activated carbon preparation by H{sub 3}PO{sub 4} activation using microwave heating method. The physico-chemical properties of activated carbons were investigated by scanning electron microscope (SEM), N{sub 2} adsorption/desorption, Boehm's titration, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). To investigate the adsorption performances of chromium onto these newly developed activated carbons, a batch of experiments were performed under different adsorption conditions: solution pH, initial Cr(VI) ion concentration, contact time and co-existing ions. The results suggested that carbon with MnCl{sub 2} as assisted activation agent displayed the highest BET surface area (1332 m{sup 2}/g) and the highest pore volume (1.060 cm{sup 3}/g). FeCl{sub 3}, AlCl{sub 3} and MnCl{sub 2} had successfully improved Cr(VI) adsorption and activated carbon with FeCl{sub 3} as assisted activation agent exhibited the best uptake capacity. To study the transformation of Cr(VI) in adsorption process, total chromium in the aqueous solution was also recorded. The ratio of the amount of Cr(VI) to Cr(III) on each adsorbent was explained by XPS analysis results. Both the co-existing salts (Na{sub 2}SO{sub 4} and NaNO{sub 3}) demonstrated promoted effects on Cr(VI) removal by four carbons. The pseudo-second-order model and Freundlich equation displayed a good correlation with

  20. Muscle activation in young men during a lower limb aquatic resistance exercise with different devices.

    Science.gov (United States)

    Borreani, Sebastien; Colado, Juan Carlos; Furio, Josep; Martin, Fernando; Tella, Víctor

    2014-05-01

    Little research has been reported on the effects of using different devices with resistance exercises in a water environment. This study compared muscular activation of lower extremity and core muscles during leg adduction performed at maximum velocity with drag and floating devices of different sizes. A total of 24 young men (mean age 23.20 ± 1.18 years) performed 3 repetitions of leg adduction at maximum velocity using 4 different devices (ie, large/small and drag/floating). The maximum amplitude of the electromyographic root mean square of the adductor longus, rectus abdominis, external oblique on the dominant side, external oblique on the nondominant side, and erector lumbar spinae were recorded. Electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). Unexpectedly, no significant (P > 0.05) differences were found in the neuromuscular responses among the different devices used; the average activation of agonist muscle adequate for neuromuscular conditioning was 40.95% of MVIC. In addition, external oblique activation is greater on the contralateral side to stabilize the body (average, 151.74%; P < 0.05). Therefore, if maximum muscle activation is required, the kind of device is not relevant. Thus, the choice should be based on economic factors.

  1. The influence of ergonomic devices on mechanical load during patient handling activities in nursing homes.

    Science.gov (United States)

    Koppelaar, Elin; Knibbe, Hanneke J J; Miedema, Harald S; Burdorf, Alex

    2012-07-01

    Mechanical load during patient handling activities is an important risk factor for low back pain among nursing personnel. The aims of this study were to describe required and actual use of ergonomic devices during patient handling activities and to assess the influence of these ergonomic devices on mechanical load during patient handling activities. For each patient, based on national guidelines, it was recorded which specific ergonomic devices were required during distinct patient handling activities, defined by transferring a patient, providing personal care, repositioning patients in the bed, and putting on and taking off anti-embolism stockings. During real-time observations over ~60 h among 186 nurses on 735 separate patient handling activities in 17 nursing homes, it was established whether ergonomic devices were actually used. Mechanical load was assessed through observations of frequency and duration of a flexed or rotated trunk >30° and frequency of pushing, pulling, lifting or carrying requiring forces 230 N from start to end of each separate patient handling activity. The number of patients and nurses per ward and the ratio of nurses per patient were used as ward characteristics with potential influence on mechanical load. A mixed-effect model for repeated measurements was used to determine the influence of ergonomic devices and ward characteristics on mechanical load. Use of ergonomic devices was required according to national guidelines in 520 of 735 (71%) separate patient handling activities, and actual use was observed in 357 of 520 (69%) patient handling activities. A favourable ratio of nurses per patient was associated with a decreased duration of time spent in awkward back postures during handling anti-embolism stocking (43%), patient transfers (33%), and personal care of patients (24%) and also frequency of manually lifting patients (33%). Use of lifting devices was associated with a lower frequency of forces exerted (64%), adjustable bed and

  2. 24 Hours of Sleep, Sedentary Behavior, and Physical Activity with Nine Wearable Devices

    Science.gov (United States)

    Rosenberger, Mary E.; Buman, Matthew P.; Haskell, William L.; McConnell, Michael V.; Carstensen, Laura L.

    2015-01-01

    Getting enough sleep, exercising and limiting sedentary activities can greatly contribute to disease prevention and overall health and longevity. Measuring the full 24-hour activity cycle - sleep, sedentary behavior (SED), light intensity physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) - may now be feasible using small wearable devices. PURPOSE This study compares nine devices for accuracy in 24-hour activity measurement. METHODS Adults (N=40, 47% male) wore nine devices for 24-hours: Actigraph GT3X+, activPAL, Fitbit One, GENEactiv, Jawbone Up, LUMOback, Nike Fuelband, Omron pedometer, and Z-Machine. Comparisons (to standards) were made for total sleep time (Z-machine), time spent in SED (activPAL), LPA (GT3x+), MVPA (GT3x+), and steps (Omron). Analysis included mean absolute percent error, equivalence testing, and Bland-Altman plots. RESULTS Error rates ranged from 8.1–16.9% for sleep; 9.5–65.8% for SED; 19.7–28.0% for LPA; 51.8–92% for MVPA; and 14.1–29.9% for steps. Equivalence testing indicated only two comparisons were significantly equivalent to standards: the LUMOback for sedentary behavior and the GT3X+ for sleep. Bland-Altman plots indicated GT3X+ had the closest measurement for sleep, LUMOback for sedentary behavior, GENEactiv for LPA, Fitbit for MVPA and GT3X+ for steps. CONCLUSIONS Currently, no device accurately captures activity data across the entire 24-hour day, but the future of activity measurement should aim for accurate 24-hour measurement as a goal. Researchers should continue to select measurement devices based on their primary outcomes of interest. PMID:26484953

  3. Nuclear-microwave-electric propulsion

    International Nuclear Information System (INIS)

    Nordley, G.D.; Brown, W.C.

    1986-01-01

    Electric propulsion can move more mass through space than chemical propulsion by virtue of the higher exhaust velocities achieved by electric propulsion devices. This performance is achieved at the expense of very heavy power sources or very long trip times, which in turn create technical and economic penalties of varying severity. These penalties include: higher operations costs, delayed availability of the payload, and increased exposure to Van Allen Belt radiation. It is proposed to reduce these penalties by physically separating the power source from the propulsion and use microwave energy beaming technology, recently explored and partially developed/tested for Solar Power Satellite concept studies, as an extension cord. This paper summarizes the state of the art of the technology needed for space based beam microwave power cost/performance trades involved with the use beamed microwave/electric propulsion for some typical orbit transfer missions and offers some suggestions for additional work

  4. Preparation of highly photocatalytic active CdS/TiO{sub 2} nanocomposites by combining chemical bath deposition and microwave-assisted hydrothermal synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li, E-mail: qqhrll@163.com [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Key Laboratory of Composite Modified Material of Colleges in Heilongjiang Province, Qiqihar 161006 (China); Wang, Lili [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Hu, Tianyu [College of Environment and Resources, Jilin University, Changchun 130024 (China); Zhang, Wenzhi; Zhang, Xiuli; Chen, Xi [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China)

    2014-10-15

    CdS/TiO{sub 2} nanocomposites were prepared from Cd and Ti (1:1 M ratio) using cetyltrimethylammonium bromide by a two-step chemical bath deposition (CBD) and microwave-assisted hydrothermal synthesis (MAHS) method. A series of nanocomposites with different morphologies and activities were prepared by varying the reaction time in the MAHS (2, 4, and 6 h). The crystal structure, morphology, and surface physicochemical properties of the nanocomposites were characterized by X-ray diffraction, UV–visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and N{sub 2} adsorption–desorption measurements. The results show that the CdS/TiO{sub 2} nanocomposites were composed of anatase TiO{sub 2} and hexagonal CdS phases with strong absorption in the visible region. The surface morphologies changed slightly with increasing microwave irradiation time, while the Brunauer–Emmett–Teller surface area increased remarkably. The photocatalytic degradation of methyl orange (MO) was investigated under UV light and simulated sunlight irradiation. The photocatalytic activity of the CdS/TiO{sub 2} (6 h) composites prepared by the MAHS method was higher than those of CdS, P25, and other CdS/TiO{sub 2} nanocomposites. The CdS/TiO{sub 2} (6 h) nanocomposites significantly affected the UV and microwave-assisted photocatalytic degradation of different dyes. To elucidate the photocatalytic reaction mechanism for the CdS/TiO{sub 2} nanocomposites, controlled experiments were performed by adding different radical scavengers. - Graphical abstract: CdS/TiO{sub 2} nanocomposites were prepared using CTAB by CBD combined with MAHS method. In addition, with increasing microwave irradiation time, the morphology of CdS/TiO{sub 2} changed from popcorn-like to wedge-like structure. - Highlights: • The CdS/TiO{sub 2} was prepared by CBD combined with MAHS two-step method under CTAB. • The morphologies of as-samples were different with the time of

  5. A passive-active neutron device for assaying remote-handled transuranic waste

    International Nuclear Information System (INIS)

    Estep, R.J.; Coop, K.L.; Deane, T.M.; Lujan, J.E.

    1990-01-01

    A combined passive-active neutron assay device was constructed for assaying remote-handled transuranic waste. A study of matrix and source position effects in active assays showed that a knowledge of the source position alone is not sufficient to correct for position-related errors in highly moderating or absorbing matrices. An alternate function for the active assay of solid fuel pellets was derived, although the efficacy of this approach remains to be established

  6. Non-volatile memory devices with redox-active diruthenium molecular compound

    International Nuclear Information System (INIS)

    Pookpanratana, S; Zhu, H; Bittle, E G; Richter, C A; Li, Q; Hacker, C A; Natoli, S N; Ren, T

    2016-01-01

    Reduction-oxidation (redox) active molecules hold potential for memory devices due to their many unique properties. We report the use of a novel diruthenium-based redox molecule incorporated into a non-volatile Flash-based memory device architecture. The memory capacitor device structure consists of a Pd/Al 2 O 3 /molecule/SiO 2 /Si structure. The bulky ruthenium redox molecule is attached to the surface by using a ‘click’ reaction and the monolayer structure is characterized by x-ray photoelectron spectroscopy to verify the Ru attachment and molecular density. The ‘click’ reaction is particularly advantageous for memory applications because of (1) ease of chemical design and synthesis, and (2) provides an additional spatial barrier between the oxide/silicon to the diruthenium molecule. Ultraviolet photoelectron spectroscopy data identified the energy of the electronic levels of the surface before and after surface modification. The molecular memory devices display an unsaturated charge storage window attributed to the intrinsic properties of the redox-active molecule. Our findings demonstrate the strengths and challenges with integrating molecular layers within solid-state devices, which will influence the future design of molecular memory devices. (paper)

  7. Fast preparation of Bi2GeO5 nanoflakes via a microwave-hydrothermal process and enhanced photocatalytic activity after loading with Ag nanoparticles

    International Nuclear Information System (INIS)

    Li, Zhao-Qian; Lin, Xin-Shan; Zhang, Lei; Chen, Xue-Tai; Xue, Zi-Ling

    2012-01-01

    Highlights: ► Bi 2 GeO 5 nanoflakes were successfully synthesized via a microwave-assisted solution-phase approach. ► Ag nanoparticles were deposited on the Bi 2 GeO 5 nanoflakes by a photoreduction procedure. ► Catalytic activity of the Ag/Bi 2 GeO 5 nanocomposite in the photo-degradation of rhodamine B (RhB) was much higher than that of pure Bi 2 GeO 5 . -- Abstract: In this work, a facile and rapid microwave-assisted hydrothermal route has been developed to prepare Bi 2 GeO 5 nanoflakes. Ag nanoparticles were subsequently deposited on the Bi 2 GeO 5 nanoflakes by a photoreduction procedure. The phases and morphologies of the products were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectrum (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and UV–vis diffuse reflectance spectroscopy. Photocatalytic experiments indicate that such Ag/Bi 2 GeO 5 nanocomposite possesses higher photocatalytic activity for RhB degradation under UV light irradiation in comparison to pure Bi 2 GeO 5 . The amount of Ag in the nanocomposite affects the catalytic activity, and 3 wt% Ag showed the highest photodegradation efficiency. Moreover, the catalyst remains active after four consecutive tests. The present study provides a new strategy to design composite materials with enhanced photocatalytic activity.

  8. Human movement activity classification approaches that use wearable sensors and mobile devices

    Science.gov (United States)

    Kaghyan, Sahak; Sarukhanyan, Hakob; Akopian, David

    2013-03-01

    Cell phones and other mobile devices become part of human culture and change activity and lifestyle patterns. Mobile phone technology continuously evolves and incorporates more and more sensors for enabling advanced applications. Latest generations of smart phones incorporate GPS and WLAN location finding modules, vision cameras, microphones, accelerometers, temperature sensors etc. The availability of these sensors in mass-market communication devices creates exciting new opportunities for data mining applications. Particularly healthcare applications exploiting build-in sensors are very promising. This paper reviews different approaches of human activity recognition.

  9. Microwave processing in MOX fuel cycle

    International Nuclear Information System (INIS)

    Mallik, G.K.; Malav, R.K.; Panakkal, J.P.; Kamath, H.S.

    2005-01-01

    The prominent aspect of the microwave heating technique applications in nuclear material processing is its eco-friendly status. It is envisaged that no active liquid waste will be generated from microwave processing. AFFF has fabricated the (U, Pu) 2 O mixed oxide fuels for PHWRs, BWRs and PFBR. AFFF is also working for the AHWR fuel cycle. The present paper summarises about the process experiments, instrumental development, results, and future applications of microwave heating technique. (author)

  10. Antifungal activity of magnetically separable Fe3O4/ZnO/AgBr nanocomposites prepared by a facile microwave-assisted method

    Directory of Open Access Journals (Sweden)

    Abolghasem Hoseinzadeh

    2016-08-01

    Full Text Available In the present work, magnetically separable Fe3O4/ZnO/AgBr nanocomposites with different weight ratios of Fe3O4 to ZnO/AgBr were prepared by a facile microwave-assisted method. The resultant samples were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM, energy dispersive analysis of X-rays (EDX, and vibrating sample magnetometery (VSM. Antifungal activity of the as-prepared samples was evaluated against Fusarium graminearum and Fusarium oxysporum as two phytopathogenic fungi. Among the nanocomposites, the sample with 1:8 weight ratio of Fe3O4 to ZnO/AgBr was selected as the best nanocomposite. This nanocomposite inactivates Fusarium graminearum and Fusarium oxysporum at 120 and 60 min, respectively. Moreover, it was observed that the microwave irradiation time has considerable influence on the antifungal activity and the sample prepared by irradiation for 10 min showed the best activity. Moreover, the nanocomposite without any thermal treatment displayed the superior activity.

  11. Monoclinic BiVO{sub 4} micro-/nanostructures: Microwave and ultrasonic wave combined synthesis and their visible-light photocatalytic activities

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yafang; Li, Guangfang; Yang, Xiaohui; Yang, Hao; Lu, Zhong [Key Laboratory for Green Chemical Process of Ministry of Education and Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Wuhan Institute of Technology, Xiongchu Avenue, Wuhan 430073 (China); Chen, Rong, E-mail: rchenhku@hotmail.com [Key Laboratory for Green Chemical Process of Ministry of Education and Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Wuhan Institute of Technology, Xiongchu Avenue, Wuhan 430073 (China); Engineering Research Center of Nano-Geomaterials of Ministry of Education, China University of Geosciences, Lumo Road, Wuhan 430074 (China)

    2013-02-25

    Graphical abstract: Monoclinic BiVO{sub 4} with different sizes and morphologies were synthesized by a facile microwave and ultrasonic wave combined technique for the first time and exhibited different optical properties and visible-light-driven photocatalytic efficiency. Highlights: Black-Right-Pointing-Pointer BiVO{sub 4} nanostructures were prepared by microwave and ultrasonic wave combined method. Black-Right-Pointing-Pointer BiVO{sub 4} nanostructures could be modulated by varying the solvent and pH value. Black-Right-Pointing-Pointer Different BiVO{sub 4} nanostructures exhibited different photocatalytic activities. Black-Right-Pointing-Pointer The photocatalytic performance was influenced by the band gap, phase and size. - Abstract: Monoclinic bismuth vanadate (m-BiVO{sub 4}) micro-/nanostructures with different sizes and morphologies were successfully prepared via a facile and rapid microwave and ultrasonic wave combined technique. The obtained BiVO{sub 4} products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and UV-vis diffuse reflection spectroscopy (DRS). It was found that the solvent and pH value had a significant influence on morphology, size and crystalline structure of the product. Nut-like, potato-like and broccoli-like monoclinic BiVO{sub 4} were fabricated in different solvents. The crystal phase could be modulated by varying the pH value of reaction system. The photocatalytic activities of the products were also evaluated by the degradation of Rhodamine B (RhB) under visible light irradiation. The result revealed that the photocatalytic activities of BiVO{sub 4} nanostructures were closely related to the crystalline phase, band gap and particle size. Monoclinic BiVO{sub 4} nanoparticles with small crystal size and large band gap exhibited remarkable photocatalytic performance.

  12. Monoclinic BiVO4 micro-/nanostructures: Microwave and ultrasonic wave combined synthesis and their visible-light photocatalytic activities

    International Nuclear Information System (INIS)

    Zhang, Yafang; Li, Guangfang; Yang, Xiaohui; Yang, Hao; Lu, Zhong; Chen, Rong

    2013-01-01

    Graphical abstract: Monoclinic BiVO 4 with different sizes and morphologies were synthesized by a facile microwave and ultrasonic wave combined technique for the first time and exhibited different optical properties and visible-light-driven photocatalytic efficiency. Highlights: ► BiVO 4 nanostructures were prepared by microwave and ultrasonic wave combined method. ► BiVO 4 nanostructures could be modulated by varying the solvent and pH value. ► Different BiVO 4 nanostructures exhibited different photocatalytic activities. ► The photocatalytic performance was influenced by the band gap, phase and size. - Abstract: Monoclinic bismuth vanadate (m-BiVO 4 ) micro-/nanostructures with different sizes and morphologies were successfully prepared via a facile and rapid microwave and ultrasonic wave combined technique. The obtained BiVO 4 products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and UV–vis diffuse reflection spectroscopy (DRS). It was found that the solvent and pH value had a significant influence on morphology, size and crystalline structure of the product. Nut-like, potato-like and broccoli-like monoclinic BiVO 4 were fabricated in different solvents. The crystal phase could be modulated by varying the pH value of reaction system. The photocatalytic activities of the products were also evaluated by the degradation of Rhodamine B (RhB) under visible light irradiation. The result revealed that the photocatalytic activities of BiVO 4 nanostructures were closely related to the crystalline phase, band gap and particle size. Monoclinic BiVO 4 nanoparticles with small crystal size and large band gap exhibited remarkable photocatalytic performance.

  13. TU-AB-204-00: CDRH/FDA Regulatory Processes and Device Science Activities

    International Nuclear Information System (INIS)

    2016-01-01

    The responsibilities of the Food and Drug Administration (FDA) have increased since the inception of the Food and Drugs Act in 1906. Medical devices first came under comprehensive regulation with the passage of the 1938 Food, Drug, and Cosmetic Act. In 1971 FDA also took on the responsibility for consumer protection against unnecessary exposure to radiation-emitting devices for home and occupational use. However it was not until 1976, under the Medical Device Regulation Act, that the FDA was responsible for the safety and effectiveness of medical devices. This session will be presented by the Division of Radiological Health (DRH) and the Division of Imaging, Diagnostics, and Software Reliability (DIDSR) from the Center for Devices and Radiological Health (CDRH) at the FDA. The symposium will discuss on how we protect and promote public health with a focus on medical physics applications organized into four areas: pre-market device review, post-market surveillance, device compliance, current regulatory research efforts and partnerships with other organizations. The pre-market session will summarize the pathways FDA uses to regulate the investigational use and commercialization of diagnostic imaging and radiation therapy medical devices in the US, highlighting resources available to assist investigators and manufacturers. The post-market session will explain the post-market surveillance and compliance activities FDA performs to monitor the safety and effectiveness of devices on the market. The third session will describe research efforts that support the regulatory mission of the Agency. An overview of our regulatory research portfolio to advance our understanding of medical physics and imaging technologies and approaches to their evaluation will be discussed. Lastly, mechanisms that FDA uses to seek public input and promote collaborations with professional, government, and international organizations, such as AAPM, International Electrotechnical Commission (IEC

  14. TU-AB-204-00: CDRH/FDA Regulatory Processes and Device Science Activities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-06-15

    The responsibilities of the Food and Drug Administration (FDA) have increased since the inception of the Food and Drugs Act in 1906. Medical devices first came under comprehensive regulation with the passage of the 1938 Food, Drug, and Cosmetic Act. In 1971 FDA also took on the responsibility for consumer protection against unnecessary exposure to radiation-emitting devices for home and occupational use. However it was not until 1976, under the Medical Device Regulation Act, that the FDA was responsible for the safety and effectiveness of medical devices. This session will be presented by the Division of Radiological Health (DRH) and the Division of Imaging, Diagnostics, and Software Reliability (DIDSR) from the Center for Devices and Radiological Health (CDRH) at the FDA. The symposium will discuss on how we protect and promote public health with a focus on medical physics applications organized into four areas: pre-market device review, post-market surveillance, device compliance, current regulatory research efforts and partnerships with other organizations. The pre-market session will summarize the pathways FDA uses to regulate the investigational use and commercialization of diagnostic imaging and radiation therapy medical devices in the US, highlighting resources available to assist investigators and manufacturers. The post-market session will explain the post-market surveillance and compliance activities FDA performs to monitor the safety and effectiveness of devices on the market. The third session will describe research efforts that support the regulatory mission of the Agency. An overview of our regulatory research portfolio to advance our understanding of medical physics and imaging technologies and approaches to their evaluation will be discussed. Lastly, mechanisms that FDA uses to seek public input and promote collaborations with professional, government, and international organizations, such as AAPM, International Electrotechnical Commission (IEC

  15. On-Chip Microwave Quantum Hall Circulator

    Directory of Open Access Journals (Sweden)

    A. C. Mahoney

    2017-01-01

    Full Text Available Circulators are nonreciprocal circuit elements that are integral to technologies including radar systems, microwave communication transceivers, and the readout of quantum information devices. Their nonreciprocity arises from the interference of microwaves over the centimeter scale of the signal wavelength, in the presence of bulky magnetic media that breaks time-reversal symmetry. Here, we realize a completely passive on-chip microwave circulator with size 1/1000th the wavelength by exploiting the chiral, “slow-light” response of a two-dimensional electron gas in the quantum Hall regime. For an integrated GaAs device with 330  μm diameter and about 1-GHz center frequency, a nonreciprocity of 25 dB is observed over a 50-MHz bandwidth. Furthermore, the nonreciprocity can be dynamically tuned by varying the voltage at the port, an aspect that may enable reconfigurable passive routing of microwave signals on chip.

  16. Comparative study of passive and semi-active energy dissipation devices intended for overhead cranes

    International Nuclear Information System (INIS)

    Guihot, P.; Revaud, D.

    1996-04-01

    This paper deals with the results of a bibliographic survey of energy dissipation devices which could be adapted for overhead cranes. The principle of passive devices using friction, yielding steel systems of viscous and viscoelastic systems are remembered. An active control system, which needs a minimum of external control energy is also presented. The application to overhead cranes which have a strong non linear behaviour under strong seismic motion (sliding between rails and wheels, local yielding and damage) is further discussed. The first results of a numerical study in progress are likewise purposed. The criterion of selection of the devices turn on the performance, the robustness and the reliability. The behaviour in the presence of non linearities, the sensitivity to the variations of the vibratory characteristics, and lastly the sensitivity to the response delay of the active controller are taken into account. (authors). 14 refs., 4 figs

  17. [Experimental study on spectra of compressed air microwave plasma].

    Science.gov (United States)

    Liu, Yong-Xi; Zhang, Gui-Xin; Wang, Qiang; Hou, Ling-Yun

    2013-03-01

    Using a microwave plasma generator, compressed air microwave plasma was excited under 1 - 5 atm pressures. Under different pressures and different incident microwave power, the emission spectra of compressed air microwave plasma were studied with a spectra measuring system. The results show that continuum is significant at atmospheric pressure and the characteristic will be weakened as the pressure increases. The band spectra intensity will be reduced with the falling of the incident microwave power and the band spectra were still significant. The experimental results are valuable to studying the characteristics of compressed air microwave plasma and the generating conditions of NO active groups.

  18. Microwave Enhanced Cotunneling in SET Transistors

    DEFF Research Database (Denmark)

    Manscher, Martin; Savolainen, M.; Mygind, Jesper

    2003-01-01

    Cotunneling in single electron tunneling (SET) devices is an error process which may severely limit their electronic and metrologic applications. Here is presented an experimental investigation of the theory for adiabatic enhancement of cotunneling by coherent microwaves. Cotunneling in SET...... transistors has been measured as function of temperature, gate voltage, frequency, and applied microwave power. At low temperatures and applied power levels, including also sequential tunneling, the results can be made consistent with theory using the unknown damping in the microwave line as the only free...

  19. New Monitoring Technology to Objectively Assess Adherence to Prescribed Footwear and Assistive Devices During Ambulatory Activity

    NARCIS (Netherlands)

    Bus, Sicco A.; Waaijman, Roelof; Nollet, Frans

    2012-01-01

    Bus SA, Waaijman R, Nollet F. New monitoring technology to objectively assess adherence to prescribed footwear and assistive devices during ambulatory activity. Arch Phys Med Rehabil 2012;93:2075-9. Objective: To assess the validity and feasibility of a new temperature-based adherence monitor to

  20. Theory and design of microwave filters

    CERN Document Server

    Hunter, Ian

    2000-01-01

    This is a thorough, graduate-level text which provides a single source for filter design including basic circuit theory, network synthesis and the design of a variety of microwave filter structures. The aim is to present design theories followed by specific examples with numerical simulations of the designs, with pictures of real devices wherever possible. The book is aimed at designers, engineers and researchers working in microwave electronics who need to design or specify filters.

  1. Study of federal microwave standards

    Energy Technology Data Exchange (ETDEWEB)

    David, L.

    1980-08-01

    Present and future federal regulatory processes which may impact the permissible levels of microwave radiation emitted by the SPS Microwave Power Transmission (MPTS) were studied. An historical development of US occupational and public microwave standards includes an overview of Western and East European philosophies of environmental protection and neurophysiology which have led to the current widely differing maximum permissible exposure limits to microwaves. The possible convergence of microwave standards is characterized by a lowering of Western exposure levels while Eastern countries consider standard relaxation. A trend toward stricter controls on activities perceived as harmful to public health is under way as is interest in improving the federal regulatory process. Particularly relevant to SPS is the initiation of long-term, low-level microwave exposure programs. Coupled with new developments in instrumentation and dosimetry, the results from chronic exposure program and population exposure studies could be expected within the next five to ten years. Also discussed is the increasing public concern that rf energy is yet another hazardous environmental agent.

  2. Keep taking the tablets? Assessing the use of tablet devices in learning and teaching activities in the Further Education sector

    OpenAIRE

    Khristin Fabian; Donald MacLean

    2014-01-01

    This article summarises the methodology and outcomes of an interventionist/action research project to assess the benefits, and potential pitfalls, of the use of mobile devices in learning and teaching activities in a Further Education environment. A bank of 15 tablet devices were purchased and prepared for classroom use. Staff members were approached to scope potential activities and uses for the tablet devices. Three departments took part in the research activity: the Language School, Social...

  3. Optimization of Microwave-Assisted Extraction of Curcumin From Curcuma longa L. (Turmeric and Evaluation of Antioxidant Activity in Multi-Test Systems

    Directory of Open Access Journals (Sweden)

    Mustafa Bener

    2016-03-01

    Full Text Available Turmeric ( Curcuma longa L. is a medicinal plant, and its biological activities mainly arise from the main constituent, known as diferuloylmethane or curcumin. In the present paper, microwave-assisted extraction (MAE was investigated for the recovery of curcumin from turmeric in comparison to conventional heat-assisted extraction (CHAE technique. Various experimental conditions, such as solvent concentration (0-100%, v/v, MAE temperature (30-130 oC and MAE time (0-20 min were investigated to optimize the extraction of curcumin from turmeric. The identification and quantification of curcumin in extracts were performed by HPLC-DAD system. Antioxidant potential and radical scavenging abilities of microwave-assisted extract and conventional heat-assisted extract of turmeric (MAET and CHAET were evaluated using different systems including total phenolic content (TPC, total antioxidant capacity (TAC, and radical scavenging activities. MAET and CHAET showed high antioxidant activity in all test systems, but the antioxidant properties of MAET were stronger than those of CHAET.

  4. Determination of the Optimal Position of Pendulums of an Active Self-balancing Device

    OpenAIRE

    Ziyakaev, Gregory Rakitovich; Kazakova, Oksana Aleksandrovna; Yankov, V. V.; Ivkina, O. P.

    2017-01-01

    The demand of the modern manufacturing industry for machines with high motion speed leads to increased load and vibration activity of the main elements of rotor systems. Vibration reduces operating life of bearings, has adversary effects on human organism, and can cause accidents. One way to compensate for a rotating rotor's imbalance is the use of active self-balancing devices. The aim of this work is to determine the position of their pendulums, in which the imbalance is minimized. As a res...

  5. Active exercises utilizing a facilitating device in the treatment of lymphedema resulting from breast cancer therapy

    Directory of Open Access Journals (Sweden)

    de Fátima Guerreiro Godoy, Maria

    2010-01-01

    Full Text Available The aim of this study was to evaluate the reduction in volume of arm lymphedema secondary to breast cancer therapy utilizing an exercise facilitating device. Twenty-one women with arm lymphedema resulting from the surgical and radiotherapeutic treatment of breast cancer were randomly selected. Evaluation was made by water-displacement volumetry before and after each session. The patients were submitted to a series of active exercises using a facilitating device for four 12-minute sessions with intervals of 3 minutes between sessions in the sitting position with alignment of the spinal column. The lymphedematous arm was maintained under compression using a cotton-polyester sleeve. The active exercising device used was a mobile flexion bar fixed on a metal base at a height of 30 cm from the tabletop and at a distance of 10 cm from the patient’s body. The paired t-test was utilized for statistical analysis with an alpha error of 5% (p-value ≤0.05 being considered significant. The initial mean volume of the arms was 2,089.9 and the final volume was 2,023.0 mL with a mean loss of 66.9 mL (p-value <0.001. In conclusion, active exercises utilizing facilitating devices can contribute to a reduction in size of lymphedematous limbs.

  6. Remote measurement of microwave distribution based on optical detection

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Zhong; Ding, Wenzheng; Yang, Sihua; Chen, Qun, E-mail: redrocks-chenqun@hotmail.com, E-mail: xingda@scnu.edu.cn; Xing, Da, E-mail: redrocks-chenqun@hotmail.com, E-mail: xingda@scnu.edu.cn [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, South China Normal University, Guangzhou 510631 (China)

    2016-01-04

    In this letter, we present the development of a remote microwave measurement system. This method employs an arc discharge lamp that serves as an energy converter from microwave to visible light, which can propagate without transmission medium. Observed with a charge coupled device, quantitative microwave power distribution can be achieved when the operators and electronic instruments are in a distance from the high power region in order to reduce the potential risk. We perform the experiments using pulsed microwaves, and the results show that the system response is dependent on the microwave intensity over a certain range. Most importantly, the microwave distribution can be monitored in real time by optical observation of the response of a one-dimensional lamp array. The characteristics of low cost, a wide detection bandwidth, remote measurement, and room temperature operation make the system a preferred detector for microwave applications.

  7. Processing method and processing device for liquid waste containing surface active agent and radioactive material

    International Nuclear Information System (INIS)

    Nishi, Takashi; Matsuda, Masami; Baba, Tsutomu; Yoshikawa, Ryozo; Yukita, Atsushi.

    1998-01-01

    Washing liquid wastes containing surface active agents and radioactive materials are sent to a deaerating vessel. Ozone is blown into the deaerating vessel. The washing liquid wastes dissolved with ozone are introduced to a UV ray irradiation vessel. UV rays are irradiated to the washing liquid wastes, and hydroxy radicals generated by photodecomposition of dissolved ozone oxidatively decompose surface active agents contained in the washing liquid wastes. The washing liquid wastes discharged from the UV ray irradiation vessel are sent to an activated carbon mixing vessel and mixed with powdery activated carbon. The surface active agents not decomposed in the UV ray irradiation vessel are adsorbed to the activated carbon. Then, the activated carbon and washing liquid wastes are separated by an activated carbon separating/drying device. Radioactive materials (iron oxide and the like) contained in the washing liquid wastes are mostly granular, and they are separated and removed from the washing liquid wastes in the activated carbon separating/drying device. (I.N.)

  8. Devices for Self-Monitoring Sedentary Time or Physical Activity: A Scoping Review.

    Science.gov (United States)

    Sanders, James P; Loveday, Adam; Pearson, Natalie; Edwardson, Charlotte; Yates, Thomas; Biddle, Stuart J H; Esliger, Dale W

    2016-05-04

    It is well documented that meeting the guideline levels (150 minutes per week) of moderate-to-vigorous physical activity (PA) is protective against chronic disease. Conversely, emerging evidence indicates the deleterious effects of prolonged sitting. Therefore, there is a need to change both behaviors. Self-monitoring of behavior is one of the most robust behavior-change techniques available. The growing number of technologies in the consumer electronics sector provides a unique opportunity for individuals to self-monitor their behavior. The aim of this study is to review the characteristics and measurement properties of currently available self-monitoring devices for sedentary time and/or PA. To identify technologies, four scientific databases were systematically searched using key terms related to behavior, measurement, and population. Articles published through October 2015 were identified. To identify technologies from the consumer electronic sector, systematic searches of three Internet search engines were also performed through to October 1, 2015. The initial database searches identified 46 devices and the Internet search engines identified 100 devices yielding a total of 146 technologies. Of these, 64 were further removed because they were currently unavailable for purchase or there was no evidence that they were designed for, had been used in, or could readily be modified for self-monitoring purposes. The remaining 82 technologies were included in this review (73 devices self-monitored PA, 9 devices self-monitored sedentary time). Of the 82 devices included, this review identified no published articles in which these devices were used for the purpose of self-monitoring PA and/or sedentary behavior; however, a number of technologies were found via Internet searches that matched the criteria for self-monitoring and provided immediate feedback on PA (ActiGraph Link, Microsoft Band, and Garmin Vivofit) and sedentary time (activPAL VT, the Lumo Back, and Darma

  9. Remote device to detect the neutrons and gamma-ray activity

    International Nuclear Information System (INIS)

    Ermakov, G.; Korolev, M.; Lopatin, Yu.; Rtishchev, A.

    1999-01-01

    The device for monitoring of gamma activity and neutrons with the following advantages was successfully developed and manufactured: extremely low power consumption which allow the long time of monitoring (up to one year or even more for GM device); high level of the intellect (build in processor); a big memory to remember results (512 Kb) including the date of events (min, hour, day, month, year); extremely simple and highly automated mode of operating; infrared interface to pass information to the external computer; high level of the IP protection; wide range of possible application. The devices could be used as follows: detection of unauthorized movement (removal) of the nuclear material and/or radioactive sources from the facility, monitoring of the radioactivity for different purposes in places with harsh climatic conditions [ru

  10. Sows’ activity classification device using acceleration data – A resource constrained approach

    DEFF Research Database (Denmark)

    Marchioro, Gilberto Fernandes; Cornou, Cécile; Kristensen, Anders Ringgaard

    2011-01-01

    This paper discusses the main architectural alternatives and design decisions in order to implement a sows’ activity classification model on electronic devices. The different possibilities are analyzed in practical and technical aspects, focusing on the implementation metrics, like cost......, performance, complexity and reliability. The target architectures are divided into: server based, where the main processing element is a central computer; and embedded based, where the processing is distributed on devices attached to the animals. The initial classification model identifies the activities...... of a heuristic classification approach, focusing on the resource constrained characteristics of embedded systems. The new approach classifies the activities performed by the sows with accuracy close to 90%. It was implemented as a hardware module that can easily be instantiated to provide preprocessed...

  11. Effect of Dopant Activation on Device Characteristics of InGaN-based Light Emitting Diodes

    Science.gov (United States)

    Lacroce, Nicholas; Liu, Guangyu; Tan, Chee-Keong; Arif, Ronald A.; Lee, Soo Min; Tansu, Nelson

    2015-03-01

    Achieving high uniformity in growths and device characteristics of InGaN-based light-emitting diodes (LEDs) is important for large scale manufacturing. Dopant activation and maintaining control of variables affecting dopant activation are critical steps in the InGaN-based light emitting diodes (LEDs) fabrication process. In the epitaxy of large scale production LEDs, in-situ post-growth annealing is used for activating the Mg acceptor dopant in the p-AlGaN and p-GaN of the LEDs. However, the annealing temperature varies with respect to position in the reactor chamber, leading to severe uniform dopant activation issue across the devices. Thus, it is important to understand how the temperature gradient and the resulting variance in Mg acceptor activation will alter the device properties. In this work, we examine the effect of varying p-type doping levels in the p-GaN layers and AlGaN electron blocking layer of the GaN LEDs on the optoelectronic properties including the band profile, carrier concentration, current density, output power and quantum efficiency. By understanding the variations and its effect, the identification of the most critical p-type doping layer strategies to address this variation will be clarified.

  12. A Novel Wearable Device for Food Intake and Physical Activity Recognition

    Directory of Open Access Journals (Sweden)

    Muhammad Farooq

    2016-07-01

    Full Text Available Presence of speech and motion artifacts has been shown to impact the performance of wearable sensor systems used for automatic detection of food intake. This work presents a novel wearable device which can detect food intake even when the user is physically active and/or talking. The device consists of a piezoelectric strain sensor placed on the temporalis muscle, an accelerometer, and a data acquisition module connected to the temple of eyeglasses. Data from 10 participants was collected while they performed activities including quiet sitting, talking, eating while sitting, eating while walking, and walking. Piezoelectric strain sensor and accelerometer signals were divided into non-overlapping epochs of 3 s; four features were computed for each signal. To differentiate between eating and not eating, as well as between sedentary postures and physical activity, two multiclass classification approaches are presented. The first approach used a single classifier with sensor fusion and the second approach used two-stage classification. The best results were achieved when two separate linear support vector machine (SVM classifiers were trained for food intake and activity detection, and their results were combined using a decision tree (two-stage classification to determine the final class. This approach resulted in an average F1-score of 99.85% and area under the curve (AUC of 0.99 for multiclass classification. With its ability to differentiate between food intake and activity level, this device may potentially be used for tracking both energy intake and energy expenditure.

  13. Preparation of silver-modified TiO2 via microwave-assisted method and its photocatalytic activity for toluene degradation

    International Nuclear Information System (INIS)

    Li Xiaobin; Wang Linling; Lu Xiaohua

    2010-01-01

    Silver-modified TiO 2 (Ag-TiO 2 ) with various Ag/Ti molar ratios were prepared by the microwave-assisted method and characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and UV-vis diffuse reflectance spectroscopy (UV-vis-DRS). Compared with the hydrothermal method, Ag-TiO 2 of small crystallite size and high crystallinity can be obtained by the microwave-assisted preparation method. When the Ag/Ti molar ratio increased from 0 to 2%, the doping of Ag promoted the phase transformation and inhibited the growth of anatase crystallite. The absorption edge of Ag-TiO 2 shifted to longer wavelength, and the band gap energy of Ag-TiO 2 decreased. However, after increasing the molar ratio Ag/Ti further from 2 to 4%, the anatase content, the crystallite size and the band gap energy of Ag-TiO 2 only increased slightly. In photodegradation gaseous toluene, the photocatalytic activity of Ag-TiO 2 increased with the increase of Ag/Ti molar ratio from 0 to 1%, but declined with the further increase to 2%. The optimal Ag/Ti molar ratio for photocatalytic activity of Ag-TiO 2 was found as 1%, with the content of anatase, rutile and brookite of 71.1, 14.5 and 14.4%, respectively. Compared with TiO 2 , Ag-TiO 2 exhibited a better photostability in toluene degradation.

  14. Evaluation of a muscle pump-activating device for non-healing venous leg ulcers.

    Science.gov (United States)

    Harris, Connie; Duong, Rochelle; Vanderheyden, Gwen; Byrnes, Beth; Cattryse, Renee; Orr, Ava; Keast, David

    2017-12-01

    This evaluation involves an innovative muscle pump-activating device (geko™) as an adjunctive therapy with best practices for non-healing venous leg ulcers (VLUs). Stimulating the common peroneal nerve (at the fibular head), the geko™ device creates a response that acts as foot and calf muscle pumps, increasing venous, arterial and microcirculatory flow. The aim was to evaluate and determine if the geko™ is effective in this population and if it should be added to the medical supply formulary. In all, 12 patients with 18 recalcitrant VLUs (defined as less than 30% reduction in wound size in 30 days with best practices) in two community settings in Ontario consented to the evaluation and were treated with the geko™ for up to 20 weeks. A total of 44% of wounds healed, and 39% decreased in size. One patient non-adherent with the geko™ and best practices had deterioration in his or her wounds. With the patients as their own control, the mean weekly healing rate with the geko™ was 9·35% (±SD 0·10) compared to 0·06% (±SD 0·10) prior to baseline, which was statistically significant (P devices in 7 of 12 (58%) patients. One patient stopped the device due to rash, while another had to take breaks from using the device. Subsequently, the manufacturer (FirstKind Ltd) has developed a new device and protocol specific to the requirements of wound therapy to minimise this response. This small case series demonstrated the highly significant effectiveness of the geko™ device in these hard-to-heal VLUs. Further evaluations to determine dose and patient selection criteria are underway. © 2017 The Authors. International Wound Journal published by Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  15. Classification of team sport activities using a single wearable tracking device.

    Science.gov (United States)

    Wundersitz, Daniel W T; Josman, Casey; Gupta, Ritu; Netto, Kevin J; Gastin, Paul B; Robertson, Sam

    2015-11-26

    Wearable tracking devices incorporating accelerometers and gyroscopes are increasingly being used for activity analysis in sports. However, minimal research exists relating to their ability to classify common activities. The purpose of this study was to determine whether data obtained from a single wearable tracking device can be used to classify team sport-related activities. Seventy-six non-elite sporting participants were tested during a simulated team sport circuit (involving stationary, walking, jogging, running, changing direction, counter-movement jumping, jumping for distance and tackling activities) in a laboratory setting. A MinimaxX S4 wearable tracking device was worn below the neck, in-line and dorsal to the first to fifth thoracic vertebrae of the spine, with tri-axial accelerometer and gyroscope data collected at 100Hz. Multiple time domain, frequency domain and custom features were extracted from each sensor using 0.5, 1.0, and 1.5s movement capture durations. Features were further screened using a combination of ANOVA and Lasso methods. Relevant features were used to classify the eight activities performed using the Random Forest (RF), Support Vector Machine (SVM) and Logistic Model Tree (LMT) algorithms. The LMT (79-92% classification accuracy) outperformed RF (32-43%) and SVM algorithms (27-40%), obtaining strongest performance using the full model (accelerometer and gyroscope inputs). Processing time can be reduced through feature selection methods (range 1.5-30.2%), however a trade-off exists between classification accuracy and processing time. Movement capture duration also had little impact on classification accuracy or processing time. In sporting scenarios where wearable tracking devices are employed, it is both possible and feasible to accurately classify team sport-related activities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Resonant activation of a Brownian particle out of a potential well: Microwave-enhanced escape from the zero-voltage state of a Josephson junction

    International Nuclear Information System (INIS)

    Devoret, M.H.; Esteve, D.; Martinis, J.M.; Cleland, A.; Clarke, J.

    1987-01-01

    A current-biased Josephson tunnel junction in its zero-voltage state can be modeled as a Brownian particle in a potential well from which it can escape by thermal activation at a rate Γ(0). The enhancement γ = Γ(I/sub m/)/Γ(0) of the escape rate has been measured in the presence of a microwave current of amplitude I/sub m/, which represents a weak, sinusoidal force driving the particle. When the microwave frequency is varied, lnγ peaks approximately at the natural frequency at which the particle oscillates at the bottom of the anharmonic potential well. At higher frequencies, lnγ exhibits a sharp roll-off that steepens as the quality factor Q of the junction is increased, while at lower frequencies lnγ has a long tail with a shape which is almost independent of Q. These features are qualitatively consistent with the theories of Ivlev and Mel'nikov and Larkin and Ovchinnikov, which we discuss. These theories however, are not able to predict analytically the behavior of lnγ near the peak. To overcome this difficulty a detailed series of computer simulations has been performed. These simulations, together with certain scaling properties of the theories, have been used to construct an empirical formula for lnγ that is in qualitative agreement with the experimentally determined frequency dependence of lnγ. The experimentally observed dependences of lnγ on temperature and microwave amplitude are in good quantitative agreement with predictions

  17. Great improvement on tetracycline removal using ZnO rod-activated carbon fiber composite prepared with a facile microwave method

    Energy Technology Data Exchange (ETDEWEB)

    Tran Thi, Viet Ha; Lee, Byeong-Kyu, E-mail: bklee@ulsan.ac.kr

    2017-02-15

    Highlights: • ZnO rod-ACF was prepared by a method involving a microwave within only 3 min. • ZnO rods (average diameter of 0.3–0.5 μm, length of 1.0–1.5 μm) were grown on ACF. • 99% of tetracycline was degraded and 90.7% TOC was removed within 1 h under UV light. • ZnO rod-ACF achieved high performances even after three cycles of uses. - Abstract: New composite materials of activated carbon fiber (ACF) coated with zinc oxide (ZnO) were obtained by applying a green, cost-effective and rapid synthetic route using a commercial microwave oven. ZnO rods with a uniform and stable structure and an average diameter of 0.3–0.5 μm and length of 1.0–1.5 μm were achieved after only 3-min microwave treatment. The properties of ZnO were efficiently transferred to ACF, such that the resulting material, termed ZnO rod-ACF, demonstrated a promising potential as an efficient photocatalyst and simultaneously as an adsorbent. Pharmaceutical tetracycline at a concentration of 40 mg/L was used to evaluate the organic pollutant removal capacity of the synthesized materials. At pH 8, ZnO rod-ACF exhibited excellent removal capacity (over 99%) and mineralization (90.7%) of tetracycline in aqueous solution within 1 h under UV irradiation. The stability of ZnO rod-ACF was maintained and the mineralization of tetracycline was also maintained at 81.35% after multiple usage cycles. The photodegradation pathways of tetracycline were proposed based on the identified reaction intermediates.

  18. Semi-active control of helicopter vibration using controllable stiffness and damping devices

    Science.gov (United States)

    Anusonti-Inthra, Phuriwat

    Semi-active concepts for helicopter vibration reduction are developed and evaluated in this dissertation. Semi-active devices, controllable stiffness devices or controllable orifice dampers, are introduced; (i) in the blade root region (rotor-based concept) and (ii) between the rotor and the fuselage as semi-active isolators (in the non-rotating frame). Corresponding semi-active controllers for helicopter vibration reduction are also developed. The effectiveness of the rotor-based semi-active vibration reduction concept (using stiffness and damping variation) is demonstrated for a 4-bladed hingeless rotor helicopter in moderate- to high-speed forward flight. A sensitivity study shows that the stiffness variation of root element can reduce hub vibrations when proper amplitude and phase are used. Furthermore, the optimal semi-active control scheme can determine the combination of stiffness variations that produce significant vibration reduction in all components of vibratory hub loads simultaneously. It is demonstrated that desired cyclic variations in properties of the blade root region can be practically achieved using discrete controllable stiffness devices and controllable dampers, especially in the flap and lag directions. These discrete controllable devices can produce 35--50% reduction in a composite vibration index representing all components of vibratory hub loads. No detrimental increases are observed in the lower harmonics of blade loads and blade response (which contribute to the dynamic stresses) and controllable device internal loads, when the optimal stiffness and damping variations are introduced. The effectiveness of optimal stiffness and damping variations in reducing hub vibration is retained over a range of cruise speeds and for variations in fundamental rotor properties. The effectiveness of the semi-active isolator is demonstrated for a simplified single degree of freedom system representing the semi-active isolation system. The rotor

  19. Methods, microfluidic devices, and systems for detection of an active enzymatic agent

    Science.gov (United States)

    Sommer, Gregory J; Hatch, Anson V; Singh, Anup K; Wang, Ying-Chih

    2014-10-28

    Embodiments of the present invention provide methods, microfluidic devices, and systems for the detection of an active target agent in a fluid sample. A substrate molecule is used that contains a sequence which may cleave in the presence of an active target agent. A SNAP25 sequence is described, for example, that may be cleaved in the presence of Botulinum Neurotoxin. The substrate molecule includes a reporter moiety. The substrate molecule is exposed to the sample, and resulting reaction products separated using electrophoretic separation. The elution time of the reporter moiety may be utilized to identify the presence or absence of the active target agent.

  20. Nonreciprocal frequency conversion in a multimode microwave optomechanical circuit

    Science.gov (United States)

    Feofanov, A. K.; Bernier, N. R.; Toth, L. D.; Koottandavida, A.; Kippenberg, T. J.

    Nonreciprocal devices such as isolators, circulators, and directional amplifiers are pivotal to quantum signal processing with superconducting circuits. In the microwave domain, commercially available nonreciprocal devices are based on ferrite materials. They are barely compatible with superconducting quantum circuits, lossy, and cannot be integrated on chip. Significant potential exists for implementing non-magnetic chip-scale nonreciprocal devices using microwave optomechanical circuits. Here we demonstrate a possibility of nonreciprocal frequency conversion in a multimode microwave optomechanical circuit using solely optomechanical interaction between modes. The conversion scheme and the results reflecting the actual progress on the experimental implementation of the scheme will be presented.

  1. CRANIOFACIAL STRESS PATTERNS AND DISPLACEMENTS AFTER ACTIVATION OF HYRAX DEVICE: FINITE ELEMENT MODELLING

    Directory of Open Access Journals (Sweden)

    Sergei Bosiakov

    2017-12-01

    Full Text Available Rapid maxillary expansion is employed for the treatment of cross-bite and deficiency of transversal dimension of the maxilla in patients with and without cleft of palate and lip. For this procedure, generally, different orthodontic appliances and devices generating significant transversal forces are used. The aim of this study is the finite-element analysis of stresses and displacements of the skull without palate cleft and the skull with unilateral and bilateral cleft after activation of the Hyrax orthodontic device. Two different constructions of the orthodontic device Hyrax with different positions of the screw relative palate are considered. In the first case, the screw is in the occlusal horizontal plane, and in the other, the screw is located near the palate. Activation of the orthodontic device corresponds to the rotation of the screw on one-quarter turn. It is established that the screw position significantly affects the distributions of stresses in skull and displacements of the cranium without palate cleft and with unilateral or bilateral palate cleft. Stresses in the bone structures of the craniums without cleft and with cleft are transferred from the maxilla to the pterygoid plate and pharyngeal tubercle if the screw displaces from the occlusal plane to the palate. Depending on the construction of the orthodontic appliance, the maxilla halves in the transversal plane are unfolded or the whole skull is entirely rotated in the sagittal plane. The stresses patterns and displacements of the skull with bilateral palate cleft are almost unchanged after activation of the orthodontic devices with different positions of the screw, only magnitudes of stresses and displacements are changed. The obtained results can be used for design of orthodontic appliances with the Hyrax screw, as well as for planning of osteotomies during the surgical assistance of the rapid maxillary expansion.

  2. Multi-Sensor Fusion for Enhanced Contextual Awareness of Everyday Activities with Ubiquitous Devices

    Directory of Open Access Journals (Sweden)

    John J. Guiry

    2014-03-01

    Full Text Available In this paper, the authors investigate the role that smart devices, including smartphones and smartwatches, can play in identifying activities of daily living. A feasibility study involving N = 10 participants was carried out to evaluate the devices’ ability to differentiate between nine everyday activities. The activities examined include walking, running, cycling, standing, sitting, elevator ascents, elevator descents, stair ascents and stair descents. The authors also evaluated the ability of these devices to differentiate indoors from outdoors, with the aim of enhancing contextual awareness. Data from this study was used to train and test five well known machine learning algorithms: C4.5, CART, Naïve Bayes, Multi-Layer Perceptrons and finally Support Vector Machines. Both single and multi-sensor approaches were examined to better understand the role each sensor in the device can play in unobtrusive activity recognition. The authors found overall results to be promising, with some models correctly classifying up to 100% of all instances.

  3. Rapid and facile preparation of zinc ferrite (ZnFe{sub 2}O{sub 4}) oxide by microwave-solvothermal technique and its catalytic activity in heterogeneous photo-Fenton reaction

    Energy Technology Data Exchange (ETDEWEB)

    Anchieta, Chayene G.; Severo, Eric C.; Rigo, Caroline; Mazutti, Marcio A. [Department of Chemical Engineering, Federal University of Santa Maria, 97105-900, Santa Maria (Brazil); Kuhn, Raquel C., E-mail: raquelckuhn@yahoo.com.br [Department of Chemical Engineering, Federal University of Santa Maria, 97105-900, Santa Maria (Brazil); Muller, Edson I.; Flores, Erico M.M. [Department of Chemistry, Federal University of Santa Maria, 97105-900, Santa Maria (Brazil); Moreira, Regina F.P.M. [Department of Chemical Engineering and Food Engineering, Federal University of Santa Catarina, 88040-970, Florianópolis (Brazil); Foletto, Edson L. [Department of Chemical Engineering, Federal University of Santa Maria, 97105-900, Santa Maria (Brazil)

    2015-06-15

    In this work zinc ferrite (ZnFe{sub 2}O{sub 4}) oxide was rapidly and easily prepared by microwave-solvothermal route and its catalytic property in photo-Fenton reaction was evaluated. The effects of microwave heating time and power on the properties of produced particles were investigated. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) and nitrogen adsorption–desorption isotherms were the techniques used for characterizing the solid products. The synthesized material was tested as a catalyst in the degradation of the textile dye molecule by the heterogeneous photo-Fenton process. Characterization results showed that the microwave heating time and power have significant influences on the formation of the phase spinel as well as on its physical properties. The reaction results showed that the ZnFe{sub 2}O{sub 4} oxide has good photocatalytic activity, which can be attributed to high surface area and pore volume, and large pore size. The ZnFe{sub 2}O{sub 4} oxide produced by the microwave irradiation exhibited promising photocatalytic activity for the removal of textile dye, reaching nearly 100% of decolorization at 40 min and 60% of mineralization at 240 min. Therefore, ZnFe{sub 2}O{sub 4} particles rapidly prepared by the microwave route have the potential for use in treatment of textile wastewater by the heterogeneous photo-Fenton process. - Highlights: • ZnFe{sub 2}O{sub 4} was synthesized by microwave-solvothermal method. • ZnFe{sub 2}O{sub 4} was prepared by different microwave heating times and powers. • ZnFe{sub 2}O{sub 4} was used as heterogeneous photo-Fenton catalyst. • Degradation of Procion red dye using heterogeneous photo-Fenton process. • ZnFe{sub 2}O{sub 4} was highly efficient to degrade textile dye under visible light.

  4. Management of water leaks on Tore Supra actively cooled fusion device

    International Nuclear Information System (INIS)

    Hatchressian, J.C.; Gargiulo, L.; Samaille, F.; Soler, B.

    2005-01-01

    Up to now, Tore Supra is the only fusion device fully equipped with actively cooled Plasma Facing Components (PFCs). In case of abnormal events during a plasma discharge, the PFCs could be submitted to a transient high power density (run away electrons) or to a continuous phenomena as local thermal flux induced by trapped suprathermal electrons or ions). It could lead to a degradation of the PFC integrity and in the worst case to a water leak occurrence. Such water leak has important consequence on the tokamak operation that concerns PFCs themselves, monitoring equipment located in the vacuum vessel or connected to the ports as RF antennas, diagnostics or pumping systems. Following successive water leak events (the most important water leak, that occurred in September 2002, is described in the paper), a large feedback experience has been gained on Tore supra since more than 15 years that could be useful to actively cooled next devices as W7X and ITER. (authors)

  5. 'Becquerel screening' device to automatically measure activity level of contaminated soil in flexible containers

    International Nuclear Information System (INIS)

    Okada, Hisashi; Yamaguchi, Yoshihisa; Yamamoto, Shuji

    2014-01-01

    Contaminated soil and incineration ash collected during offsite decontamination work following the accident at the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co., Inc. is being stored in flexible containers. These containers are managed taking their activity level into account in accordance with the Decontamination Guidelines issued by the Ministry of the Environment. Toshiba has developed the 'Becquerel Screening' device that can automatically measure the activity level of the contents of each flexible container simply by placing the container on a palette, without the need to take samples for analysis from the container. The Becquerel Screening device is expected to contribute not only to improved operational efficiency but also to reduced exposure of operators to radiation, because it eliminates the need for direct contact with contaminated soil and ash. (author)

  6. H2O2 induced cost effective microwave disintegration of dairy waste activated sludge in acidic environment for efficient biomethane generation.

    Science.gov (United States)

    Eswari, A Parvathy; Kavitha, S; Banu, J Rajesh; Karthikeyan, O Parthiba; Yeom, Ick-Tae

    2017-11-01

    This study aimed to improve the biomethane potential of dairy waste activated sludge (WAS) by H 2 O 2 -acidic pH induced microwave disintegration (HAMW-D) pretreatment approach. The results of HAMW-D compared with the microwave disintegration (MW-D) alone for energy and economic factors. In the two phase disintegration process, the H 2 O 2 concentration of about 0.5mg/g SS under acid pH of 5 was found to be optimum for effective dissociation of Extracellular Polymeric Substances (EPS) matrix. A higher liquefaction of about 46.6% was achieved in HAMW-D when compared to that of MW-D (30%). It subsequently improved the methane yield of about 250mL/g VS in HAMW-D, which was 9.6% higher than MW-D. A net profit of about 49€/ton was achieved for HAMW-D, therefore it is highly recommended for WAS pretreatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Antioxidant activity measurement and potential antioxidant peptides exploration from hydrolysates of novel continuous microwave-assisted enzymolysis of the Scomberomorus niphonius protein.

    Science.gov (United States)

    Huang, Yipeng; Ruan, Guihua; Qin, Zhijun; Li, Haiyun; Zheng, Yanjie

    2017-05-15

    A novel continuous microwave-assisted enzymatic digestion (cMAED) method is proposed for the digestion of protein from Scomberomorus niphonius to obtain potential antioxidant peptides. In this study, bromelain was found to have a high capacity for the digestion of the Scomberomorus niphonius protein. The following cMAED conditions were investigated: protease species, microwave power, temperature, bromelain content, acidity of the substrate solution, and incubation time. At 400W, 40°C, 1500U·g -1 bromelain, 20% substrate concentration, pH 6.0 and 5min incubation, the degree of hydrolysis and total antioxidant activity of the hydrolysates were 15.86% and 131.49μg·mL -1 , respectively. The peptide analyses showed that eight of the potential antioxidant peptide sequences, which ranged from 502.32 to 1080.55Da with 4-10 amino acid residues, had features typical of well-known antioxidant proteins. Thus, the new cMAED method can be useful to obtain potential antioxidant peptides from protein sources, such as Scomberomorus niphonius. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Electro-catalytic activity of multiwall carbon nanotube-metal (Pt or Pd) nanohybrid materials synthesized using microwave-induced reactions and their possible use in fuel cells.

    Science.gov (United States)

    V, Lakshman Kumar; Ntim, Susana Addo; Sae-Khow, Ornthida; Janardhana, Chelli; Lakshminarayanan, V; Mitra, Somenath

    2012-11-30

    Microwave induced reactions for immobilizing platinum and palladium nanoparticles on multiwall carbon nanotubes are presented. The resulting hybrid materials were used as catalysts for direct methanol, ethanol and formic acid oxidation in acidic as well as alkaline media. The electrodes are formed by simply mixing the hybrids with graphite paste, thus using a relatively small quantity of the precious metal. We report Tafel slopes and apparent activation energies at different potentials and temperatures. Ethanol electro-oxidation with the palladium hybrid showed an activation energy of 7.64 kJmol(-1) which is lower than those observed for other systems. This system is economically attractive because Pd is significantly less expensive than Pt and ethanol is fast evolving as a commercial biofuel.

  9. Electro-catalytic activity of multiwall carbon nanotube-metal (Pt or Pd) nanohybrid materials synthesized using microwave-induced reactions and their possible use in fuel cells

    Science.gov (United States)

    V, Lakshman Kumar; Ntim, Susana Addo; Sae-Khow, Ornthida; Janardhana, Chelli; Lakshminarayanan, V.; Mitra, Somenath

    2012-01-01

    Microwave induced reactions for immobilizing platinum and palladium nanoparticles on multiwall carbon nanotubes are presented. The resulting hybrid materials were used as catalysts for direct methanol, ethanol and formic acid oxidation in acidic as well as alkaline media. The electrodes are formed by simply mixing the hybrids with graphite paste, thus using a relatively small quantity of the precious metal. We report Tafel slopes and apparent activation energies at different potentials and temperatures. Ethanol electro-oxidation with the palladium hybrid showed an activation energy of 7.64 kJmol−1 which is lower than those observed for other systems. This system is economically attractive because Pd is significantly less expensive than Pt and ethanol is fast evolving as a commercial biofuel. PMID:23118490

  10. Chemical composition and antibacterial activity of Origanum saccatum P.H. Davis essential oil obtained by solvent-free microwave extraction: comparison with hydrodistillation.

    Science.gov (United States)

    Sozmen, Fazli; Uysal, Burcu; Oksal, Birsen S; Kose, Elif Odabas; Deniz, I Gokhan

    2011-01-01

    The components of the essential oils (EOs) obtained by solvent-free microwave extraction (SFME) and hydrodistillation (HD) from endemic Origanum saccatum P.H. Davis were identified by using GC/MS. The main constituents of both EOs obtained by SFME and HD, respectively, from O. saccatum were p-cymene (72.5 and 70.6%), thymol (9.32 and 8.11%), and carvacrol (7.18 and 6.36%). The EO obtained by SFME contained substantially higher amounts of oxygenated compounds and lower amounts of monoterpenes than did the EO obtained by HD. The antibacterial activities of the EOs obtained by SFME and HD were evaluated with the disc diffusion method by comparison with 10 different bacterial strains. The antibacterial activity of the EO extracted by SFME was found to be more effective than that of the EO extracted by HD against seven of the tested bacteria.

  11. Microwave-Based Water Decontamination System

    Science.gov (United States)

    Arndt, G. Dickey (Inventor); Byerly, Diane (Inventor); Sognier, Marguerite (Inventor); Dusl, John (Inventor)

    2016-01-01

    A system for decontaminating a medium. The system can include a medium having one or more contaminants disposed therein. The contaminants can be or include bacteria, fungi, parasites, viruses, and combinations thereof. A microwave energy radiation device can be positioned proximate the medium. The microwave energy radiation device can be adapted to generate a signal having a frequency from about 10 GHz to about 100 GHz. The signal can be adapted to kill one or more of the contaminants disposed within the medium while increasing a temperature of the medium by less than about 10 C.

  12. Characterization of obsidian devices come from San Miguel Ixtapan, Estado de Mexico by Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Almazan T, M.G.; Jimenez R, M.; Monroy G, F.; Tenorio C, D.

    2002-01-01

    The Neutron Activation Analysis (NAA) is an efficient multielemental technique for determination of elements in low concentration (ppm), what has been result useful in the study of origin of archaeological material. In this work that technique was used for characterizing obsidian devices coming from the San Miguel Ixtapan site, Estado de Mexico and it was found that these come from three important beds which are: Sierra de Pachuca, Hidalgo, Zinapecuaro and Zinaparo-Varal in the Michoacan state. (Author)

  13. Function Activation on Intelligent Buildings Using Mobile Devices through Voice Commands

    Directory of Open Access Journals (Sweden)

    Moumtadi Fatima

    2014-04-01

    Full Text Available Development of information and communication technologies has allowed the incorporation into different areas of human activity of apps that control electrical and electronic devices through voice commands. With these apps, in telemedicine people affected by some temporary decrease in their physical capacities have improved their level of autonomy; utilities have been added to educational environments to facilitate the use of IT applications to users with physical disability; finally, home automated solutions have made possible to any person with permanent limited mobility to take control over home devices using voice commands. In this article a home automated solution, developed over a client-server principle is presented. As the client device a MIDP 2.0 cell phone with a Java MicroEdition application loaded was used; as server a web server PC was used serving also as gateway towards a Konnex network, added with a speech recognizer engine. Fully functional prototype developed allowed take control over 3 devices with 87% success of the speech recognizer reliability, this percentage improved after the use of a drop-down menu of commands displayed over the monitor.

  14. Use of a Far-Infrared Active Warming Device in Guinea Pigs (Cavia porcellus).

    Science.gov (United States)

    Zarndt, Bethany S; Buchta, Jessica N; Garver, Lindsey S; Davidson, Silas A; Rowton, Edgar D; Despain, Kenneth E

    2015-11-01

    Small mammals have difficulty maintaining body temperature under anesthesia. This hypothermia is a potential detriment not only to the health and comfort of the animal but also to the integrity of any treatment given or data gathered during the anesthetic period. Using an external warming device to assist with temperature regulation can mitigate these effects. In this study, we investigated the ability of an advanced warming device that uses far-infrared (FIR) heating and responds to real-time core temperature monitoring to maintain a normothermic core temperature in guinea pigs. Body temperatures were measured during 30 min of ketamine-xylazine general anesthesia with and without application of the heating device. The loss of core body heat from anesthetized guinea pigs under typical (unwarmed) conditions was significant, and this loss was almost completely mitigated by application of the FIR heating pad. The significant difference between the temperatures of the actively warmed guinea pigs as compared with the control group began as early as 14 min after anesthetic administration, leading to a 2.6 °C difference at 30 min. Loss of core body temperature was not correlated with animals' body weight; however, weight influences the efficiency of FIR warming slightly. These study results show that the FIR heating device accurately controls core body temperature in guinea pigs, therefore potentially alleviating the effects of body heat loss on animal physiology.

  15. The further development of the active urine collection device: a novel continence management system.

    Science.gov (United States)

    Tinnion, E; Jowitt, F; Clarke-O'Neill, S; Cottenden, A M; Fader, M; Sutherland, I

    2003-01-01

    Continence difficulties affect the lives of a substantial minority of the population. Women are far more likely than men to be affected by urinary incontinence but the range of management options for them is limited. There has been considerable interest in developing an external urine collection system for women but without success to date. This paper describes the development and preliminary clinical testing of an active urine collection device (AUCD), which could provide a solution for sufferers. The device uses stored vacuum, protected by a high bubble point filter, to remove urine as quickly as it is produced. This allows a small battery-operated pump to provide the required vacuum, enabling the device to be portable. Two different types of non-invasive patient/device interface were developed, and tested by volunteers: urinal and small pad. The slimline urinal was popular with users although liquid noise was a problem. The pad interface was successful on occasions but further work is necessary to produce a reliable pad. This study has successfully demonstrated that a prototype AUCD liquid handling system can remove urine at clinically relevant flowrates. While further development is required, volunteer tests have shown that the AUCD could be a useful advance in continence management.

  16. Determination of the Optimal Position of Pendulums of an Active Self-balancing Device

    Science.gov (United States)

    Ziyakaev, G. R.; Kazakova, O. A.; Yankov, V. V.; Ivkina, O. P.

    2017-04-01

    The demand of the modern manufacturing industry for machines with high motion speed leads to increased load and vibration activity of the main elements of rotor systems. Vibration reduces operating life of bearings, has adversary effects on human organism, and can cause accidents. One way to compensate for a rotating rotor's imbalance is the use of active self-balancing devices. The aim of this work is to determine the position of their pendulums, in which the imbalance is minimized. As a result of the study, a formula for determining the angle of the pendulums was obtained.

  17. Microwave integrated circuit for Josephson voltage standards

    Science.gov (United States)

    Holdeman, L. B.; Toots, J.; Chang, C. C. (Inventor)

    1980-01-01

    A microwave integrated circuit comprised of one or more Josephson junctions and short sections of microstrip or stripline transmission line is fabricated from thin layers of superconducting metal on a dielectric substrate. The short sections of transmission are combined to form the elements of the circuit and particularly, two microwave resonators. The Josephson junctions are located between the resonators and the impedance of the Josephson junctions forms part of the circuitry that couples the two resonators. The microwave integrated circuit has an application in Josephson voltage standards. In this application, the device is asymmetrically driven at a selected frequency (approximately equal to the resonance frequency of the resonators), and a d.c. bias is applied to the junction. By observing the current voltage characteristic of the junction, a precise voltage, proportional to the frequency of the microwave drive signal, is obtained.

  18. Mobile and Wearable Device Features that Matter in Promoting Physical Activity.

    Science.gov (United States)

    Wang, Julie B; Cataldo, Janine K; Ayala, Guadalupe X; Natarajan, Loki; Cadmus-Bertram, Lisa A; White, Martha M; Madanat, Hala; Nichols, Jeanne F; Pierce, John P

    2016-07-01

    As wearable sensors/devices become increasingly popular to promote physical activity (PA), research is needed to examine how and which components of these devices people use to increase their PA levels. (1) To assess usability and level of engagement with the Fitbit One and daily SMS-based prompts in a 6-week PA intervention, and (2) to examine whether use/ level of engagement with specific intervention components were associated with PA change. Data were analyzed from a randomized controlled trial that compared (1) a wearable sensor/ device (Fitbit One) plus SMS-based PA prompts, and (2) Fitbit One only, among overweight/ obese adults (N = 67). We calculated average scores from Likert-type response items that assessed usability and level of engagement with device features (e.g., tracker, website, mobile app, and SMS-based prompts), and assessed whether such factors were associated with change in steps/day (using Actigraph GT3X+). Participants reported the Fitbit One was easy to use and the tracker helped to be more active. Those who used the Fitbit mobile app (36%) vs. those who did not (64%) had an increase in steps at 6-week follow-up, even after adjusting for previous web/app use: +545 steps/ day ( SE = 265) vs. -28 steps/ day ( SE = 242) ( p = .04). Level of engagement with the Fitbit One, particularly the mobile app, was associated with increased steps. Mobile apps can instantly display summaries of PA performance and could optimize self-regulation to activate change. More research is needed to determine whether such modalities might be cost-effective in future intervention research and practice.

  19. Microwave irradiation effects on vermicasts potency, and plant growth and antioxidant activity in seedlings of Chinese cabbage (Brassica rapa subsp. pekinensis

    Directory of Open Access Journals (Sweden)

    Lord Abbey

    2017-04-01

    Full Text Available Vermicasts is rich in beneficial microorganisms and plant growth factors. Unlike soils, the effect of microwave irradiation (MWI on vermicasts potency has not been reported. This study investigated MWI effects on vermicasts potency, plant growth and biochemical activity in Chinese cabbage ‘Bilko’ seedlings. Fresh, moist vermicasts were microwaved at power output levels: 0, 100, 200, 300, 400 and 800 Watts (W. Water loss, nutrients and total aerobic plate content were assessed. A complete randomized design greenhouse experiment was used to evaluate seedlings growth performance and tissue bioactivity. Water loss increased from 5 mg/g (0 W to 215 mg/g (800 W. Total dissolved solids and electrical conductivity of the vermicasts gradually increased with an increase in MWI power output level from 0 to 200 W. This was followed by a steep rise through treatment 300 W and a peak at 400 W. Total nitrogen and nitrate decreased, while ammonia-nitrogen and nitrite-nitrogen increased at higher power levels. Similarly, phosphorus, potassium, magnesium, calcium, manganese, barium and molybdenum contents increased while sodium and barium remained fairly constant. However, MWI irradiation reduced total aerobic plate count by ≥50%. Plant growth and biomass were increased by the 400 W and 800 W MWI treatments. Antioxidant activity was highest in 200, 400 and 800 W treated plants. Collectively the finding indicated that the 400 W treatment increased the bioavailability of nutrients, and represents the best option for plant growth enhancement and improved antioxidant activity.

  20. The gas-filled counting tube of the PTB - a device for the activity determination of radioactive gases

    International Nuclear Information System (INIS)

    Guenther, E.W.

    1993-08-01

    A measuring device for the activity determination of gaseous radioactive materials (H-3, Kr-85, C-14 O 2 ) has been set up as a PTB primary standard. Samples measured in it or their initial substances are the basis for activity standards. The gaseous samples are introduced directly into the vacuum device. The amount of gas filled can be determined by measuring pressure, volume and temperature. After the gas has been mixed with a counting gas (methane, argon/methane or propane), the count-rates are measured and the activity of the gas calculated. The activity of solid or liquid radioactive substances can also be determined with the device described, if they can be converted into a suitable gas. For this purpose there are additional devices (e.g. for producing hydrogen from water or C-14 O 2 from carbonate). The first models of these devices have been developed and are described. (orig.) [de

  1. Advanced Microwave Circuits and Systems

    DEFF Research Database (Denmark)

    This book is based on recent research work conducted by the authors dealing with the design and development of active and passive microwave components, integrated circuits and systems. It is divided into seven parts. In the first part comprising the first two chapters, alternative concepts...... amplifier architectures. In addition, distortion analysis and power combining techniques are considered. Another key element in most microwave systems is a signal generator. It forms the heart of all kinds of communication and radar systems. The fourth part of this book is dedicated to signal generators...... push currently available technologies to the limits. Some considerations to meet the growing requirements are provided in the fifth part of this book. The following part deals with circuits based on LTCC and MEMS technologies. The book concludes with chapters considering application of microwaves...

  2. Compact Microwave Fourier Spectrum Analyzer

    Science.gov (United States)

    Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry

    2009-01-01

    A compact photonic microwave Fourier spectrum analyzer [a Fourier-transform microwave spectrometer, (FTMWS)] with no moving parts has been proposed for use in remote sensing of weak, natural microwave emissions from the surfaces and atmospheres of planets to enable remote analysis and determination of chemical composition and abundances of critical molecular constituents in space. The instrument is based on a Bessel beam (light modes with non-zero angular momenta) fiber-optic elements. It features low power consumption, low mass, and high resolution, without a need for any cryogenics, beyond what is achievable by the current state-of-the-art in space instruments. The instrument can also be used in a wide-band scatterometer mode in active radar systems.

  3. Microwave energy transmission

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Hiroshi [Kyoto Univ. (Japan)

    1989-03-05

    Laying stress on the technological problems and effect on the environment of microwave energy transmission, recent scientific and engineering problems and related subjects are described. Because no fuel is required for the solar power generation, the power generation system can not be considered as an expensive one when the unit cost of energy is taken into consideration. Some of the important technological problems in the microwave energy transmission are accurate microwave beam control technology to receiving stations and improvement in the efficiency of transmission system. Microwave energy beam has effects on living bodies, communication, and plasma atmosphere of the earth. Microwave energy transmission using a space flyer unit is scheduled. Its objective is the development of microwave wireless transmission technology and the study of the correlation between high power microwave and ionosphere plasma. Experiments on such a small scale application as a microwave driven space ship to bring results seem also important. 12 refs., 13 figs.

  4. DEVICE FOR MEASURING OF THERMAL LENS PARAMETERS IN LASER ACTIVE ELEMENTS WITH A PROBE BEAM METHOD

    Directory of Open Access Journals (Sweden)

    A. N. Zakharova

    2015-01-01

    Full Text Available We have developed a device for measuring of parameters of thermal lens (TL in laser active elements under longitudinal diode pumping. The measurements are based on the probe beam method. This device allows one to determine sign and optical power of the lens in the principal meridional planes, its sensitivity factor with respect to the absorbed pump power and astigmatism degree, fractional heat loading which make it possible to estimate integral impact of the photoelastic effect to the formation of TL in the laser element. The measurements are performed in a linearly polarized light at the wavelength of 532 nm. Pumping of the laser element is performed at 960 nm that makes it possible to study laser materials doped with Yb3+ and (Er3+, Yb3+ ions. The precision of measurements: for sensitivity factor of TL – 0,1 m-1/W, for astigmatism degree – 0,2 m-1/W, for fractional heat loading – 5 %, for the impact of the photoelastic effect – 0,5 × 10-6 K-1. This device is used for characterization of thermal lens in the laser active element from an yttrium vanadate crystal, Er3+,Yb3+:YVO .

  5. Trends of microwave dielectric materials for antenna application

    International Nuclear Information System (INIS)

    Sulong, T. A. T.; Osman, R. A. M.; Idris, M. S.

    2016-01-01

    Rapid development of a modern microwave communication system requires a high quality microwave dielectric ceramic material to be used as mobile and satellite communication. High permittivity of dielectric ceramics leads to fabrication of compact device for electronic components. Dielectric ceramics which used for microwave applications required three important parameters such as high or appropriate permittivity (ε_r), high quality factor (Q _f ≥ 5000 GH z) and good temperature coefficient of resonant frequency (τ_f). This paper review of various dielectric ceramic materials used as microwave dielectric materials and related parameters for antenna applications.

  6. Trends of microwave dielectric materials for antenna application

    Energy Technology Data Exchange (ETDEWEB)

    Sulong, T. A. T., E-mail: tuanamirahtuansulong@gmail.com; Osman, R. A. M., E-mail: rozana@unimap.edu.my [School of Microelectronic Engineering, Universiti Malaysia Perlis, Pauh Putra Campus, 02600 Arau, Perlis (Malaysia); Idris, M. S., E-mail: sobri@unimap.edu.my [Sustainable Engineering Research Cluster, School of Material Engineering, Universiti Malaysia Perlis, Blok B, Taman Pertiwi Indah, Seriab, 01000 Kangar, Perlis (Malaysia)

    2016-07-19

    Rapid development of a modern microwave communication system requires a high quality microwave dielectric ceramic material to be used as mobile and satellite communication. High permittivity of dielectric ceramics leads to fabrication of compact device for electronic components. Dielectric ceramics which used for microwave applications required three important parameters such as high or appropriate permittivity (ε{sub r}), high quality factor (Q {sub f} ≥ 5000 GH z) and good temperature coefficient of resonant frequency (τ{sub f}). This paper review of various dielectric ceramic materials used as microwave dielectric materials and related parameters for antenna applications.

  7. Advances in microwaves 7

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 7 covers the developments in the study of microwaves. The book discusses the effect of surface roughness on the propagation of the TEM mode, as well as the voltage breakdown of microwave antennas. The text also describes the theory and design considerations of single slotted-waveguide linear arrays and the techniques and theories that led to the achievement of wide bandwidths and ultralow noise temperatures for communication applications. The book will prove invaluable to microwave engineers.

  8. Absence of genotoxic activity from milk and water boiled in microwave oven in somatic cells from Drosophila melanogaster; Ausencia da atividade genotoxica do leite e agua, fervidos com microondas, em celulas somaticas de Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Cristina das Dores. E-mail: crisddias@yahoo.com.br

    2003-07-01

    This paper reports an experiment for evaluation of the possible genotoxic effects of food prepared in a microwave oven, through the mutation test and somatic recombination, in wings of Drosophila melanogaster. Two crossing have been performed: a standard cross-ST and a high bioactivation cross - HB resulting in marked trans -heterozygote descendents (MH) and balanced heterozygotes (BH). The 72 hours larvas were fed with water and milk boiled both in the microwave oven and in the traditional way. The MH individual wings were analyzed, where the spots can be induced either by mutation or mitotic recombination. The experiment presented negative results related to the genotoxic effects of the water and milk boiled using the microwave oven, in MH descendents of both crossing. Therefore, under these experimental conditions, genotoxic activity were not presented by milk and water boiled in the microwave oven. However, an extensive study using different techniques is necessary to investigate the action of the food prepared in the microwave oven on the genetic material.

  9. Microwave field-efffect transistors theory, design, and application

    CERN Document Server

    Pengelly, Raymond

    1994-01-01

    This book covers the use of devices in microwave circuits and includes such topics as semiconductor theory and transistor performance, CAD considerations, intermodulation, noise figure, signal handling, S-parameter mapping, narrow- and broadband techniques, packaging and thermal considerations.

  10. Advancements of microwave diagnostics in magnetically confined plasmas

    NARCIS (Netherlands)

    Mase, A.; Kogi, Y.; Ito, N.; Yokota, Y.; Akaki, K.; Kawahata, K.; Nagayama, Y.; Tokuzawa, T.; Yamaguchi, S.; Hojo, H.; Oyama, N.; N C Luhmann Jr.,; Park, H. K.; Donne, A. J. H.

    2009-01-01

    Microwave to millimeter-wave diagnostic techniques such as interferometry, reflectometry, scattering and radiometry have been powerful tools for diagnosing magnetically confined plasmas. Recent advances in electronic devices and components together with computer technology have enabled the

  11. Aloe vera in active and passive regions of electronic devices towards a sustainable development

    Science.gov (United States)

    Lim, Zhe Xi; Sreenivasan, Sasidharan; Wong, Yew Hoong; Cheong, Kuan Yew

    2017-07-01

    The increasing awareness towards sustainable development of electronics has driven the search for natural bio-organic materials in place of conventional electronic materials. The concept of using natural bio-organic materials in electronics provides not only an effective solution to address global electronic waste crisis, but also a compelling template for sustainable electronics manufacturing. This paper attempts to provide an overview of using Aloe vera gel as a natural bio-organic material for various electronic applications. Important concepts such as responses of living Aloe vera plant towards electrical stimuli and demonstrations of Aloe vera films as passive and active regions of electronic devices are highlighted in chronological order. The biodegradability and biocompatibility of Aloe vera can bring the world a step closer towards the ultimate goal of sustainable development of electronic devices from "all-natural" materials.

  12. A versatile passive and active non-destructive device for spent fuel assemblies monitoring

    International Nuclear Information System (INIS)

    Berne, R.; Bignan, G.; Andrieu, G.; Dethan, B.

    1993-01-01

    The monitoring of spent fuel assemblies in reactor pools or in reprocessing plants with NDA methods is interesting (non-destructivity, non-intrusivity) for process control, safety-criticality and/or nuclear material management. In this context, the authors present the results of the development and design of a prototype device (physical methods used, qualification...) called PYTHON. The aim of PYTHON is to check the declared characteristic values of an irradiated assembly before taking it into a transport cask for safety criticality control. The PYTHON device consists of a detector head in two sections and a 252 Cf source if active neutron counting is to be used. Each section of the detection head consists of two detectors: one fission chamber and one ionization chamber

  13. Solvent-free microwave-assisted synthesis of novel pyrazolo[4′,3′:5,6]pyrido[2,3-d]pyrimidines with potential antifungal activity

    Directory of Open Access Journals (Sweden)

    Paola Acosta

    2016-05-01

    Full Text Available Novel fused pyrazolo[4′,3′:5,6]pyrido[2,3-d]pyrimidines 5 were prepared by a solvent-free microwave assisted reaction of heterocyclic o-aminonitriles 3 and cyanopyridines 4 in the presence of tBuOK as catalyst. This protocol provides a versatile procedure for the synthesis of the title compounds with the advantages of easy work-up, mild reaction conditions and good yields. All compounds were also tested for antifungal properties against two clinically important fungi; Candida albicans and Cryptococcus neoformans. Several compounds showed moderate activity against both fungi, being 5a the most active compound. Analysis of the antifungal behavior of properly grouped compounds allowed to determine that the position of the N in the pyrimidyl moiety per se does not play a role in the activity. In turn, the type of 4-R substituent appears to influence the activity. In addition to the above considerations, the lipophilicity of compounds measured as logP showed to be not related to the activity and regarding the dipole moment (D, no net correlation was observed, although it is the most active compounds (% inhibition >50% that have a D ⩾ 7.5, mainly against C. albicans.

  14. Microwave processing heats up

    Science.gov (United States)

    Microwaves are a common appliance in many households. In the United States microwave heating is the third most popular domestic heating method food foods. Microwave heating is also a commercial food processing technology that has been applied for cooking, drying, and tempering foods. It's use in ...

  15. Cosmic Microwave Background Timeline

    Science.gov (United States)

    Cosmic Microwave Background Timeline 1934 : Richard Tolman shows that blackbody radiation in an will have a blackbody cosmic microwave background with temperature about 5 K 1955: Tigran Shmaonov anisotropy in the cosmic microwave background, this strongly supports the big bang model with gravitational

  16. Design and implementation of multichannel global active structural acoustic control for a device casing

    Science.gov (United States)

    Mazur, Krzysztof; Wrona, Stanislaw; Pawelczyk, Marek

    2018-01-01

    The paper presents the idea and discussion on implementation of multichannel global active noise control systems. As a test plant an active casing is used. It has been developed by the authors to reduce device noise directly at the source by controlling vibration of its casing. To provide global acoustic effect in the whole environment, where the device operates, it requires a number of secondary sources and sensors for each casing wall, thus making the whole active control structure complicated, i.e. with a large number of interacting channels. The paper discloses all details concerning hardware setup and efficient implementation of control algorithms for the multichannel case. A new formulation is presented to introduce the distributed version of the Switched-error Filtered-reference Least Mean Squares (FXLMS) algorithm together with adaptation rate enhancement. The convergence rate of the proposed algorithm is compared with original Multiple-error FXLMS. A number of hints followed from many years of authors' experience on microprocessor control systems design and signal processing algorithms optimization are presented. They can be used for various active control and signal processing applications, both for academic research and commercialization.

  17. Pyrolysis of methane by microwaves. Pt. 1

    International Nuclear Information System (INIS)

    Avni, R.; Winefordner, J.D.; Nickel, H.

    1975-04-01

    The pyrolysis of methane and mixtures of argon-methane by microwaves (2,450 MHz) was investigated. The microwave plasma diagnostic study was performed using electrical probes, namely, the double floating probe technique. Parameters such as electric field strength and current densities were measured and from their relationship the electron temperature, electric conductivity, electron and ion densities were evaluated as function of gas pressure, microwave power input and distance of the probe from the microwave cavity. Various spectroscopic techniques were used for the measurement of temperatures in the microwave plasma; the 'reversal temperature' by measuring the intensities of the electronic vibrational bands of CN and OH molecules and 'rotational temperature' from the measured intensities of rotational OH lines. The 'rotational' as well as the 'reversal temperature' were found to be identical and this temperature was assumed to be the temperature of the gas in the microwave plasma. Energy balance calculation, based upon the electrical energy input and thermal losses, were performed in order to determine if steady state conditions existed in the microwave plasma. Emission and absorption spectroscopy were used for determining the active species formed in the pyrolysis of methane and also of mixtures of CH 4 -Ar, by the microwave plasma. (orig.) [de

  18. Multikilowatt variable frequency microwave furnace

    International Nuclear Information System (INIS)

    Bible, D.W.; Lauf, R.J.; Everleigh, C.A.

    1992-01-01

    In this paper, the authors describe a new type of microwave processing furnace in which the frequency can be varied continuously from 4 to 8 GHz and the power level varied from zero up to 2.5 kW. The extraordinary bandwidth of this furnace is achieved by using a traveling wave tube (TWT) amplifier originally developed for electronic warfare applications. The TWT is a linear beam device characterized by a traveling electromagnetic wave that continuously extracts energy longitudinally along the path of an electron beam. The TWT, unlike other microwave tubes such as the magnetron, klystron, gyrotron, and others, does not depend upon resonant RF fields and is therefore capable of wide bandwidth operation.operation

  19. System of extraction of volatiles from soil using microwave processes

    Science.gov (United States)

    Ethridge, Edwin C. (Inventor); Kaukler, William F. (Inventor)

    2013-01-01

    A device for the extraction and collection of volatiles from soil or planetary regolith. The device utilizes core drilled holes to gain access to underlying volatiles below the surface. Microwave energy beamed into the holes penetrates through the soil or regolith to heat it, and thereby produces vapor by sublimation. The device confines and transports volatiles to a cold trap for collection.

  20. Electric devices used in radioactive handling enclosures of the high activity laboratory

    International Nuclear Information System (INIS)

    Gaigeot, F.; Laurent, H.

    1958-08-01

    This report describes several electric, electronic and electromechanical assemblies which are used in radioactive handling enclosures. The authors propose an overview of existing or foreseen devices: a device to lift covers, a brightness comparator, a high voltage device to perform electrophoresis, a level sensor or regulator device, a regulation device to control under-pressure in an enclosure [fr

  1. Device-based monitoring in physical activity and public health research

    International Nuclear Information System (INIS)

    Bassett, David R

    2012-01-01

    Measurement of physical activity is important, given the vital role of this behavior in physical and mental health. Over the past quarter of a century, the use of small, non-invasive, wearable monitors to assess physical activity has become commonplace. This review is divided into three sections. In the first section, a brief history of physical activity monitoring is provided, along with a discussion of the strengths and weaknesses of different devices. In the second section, recent applications of physical activity monitoring in physical activity and public health research are discussed. Wearable monitors are being used to conduct surveillance, and to determine the extent and distribution of physical activity and sedentary behaviors in populations around the world. They have been used to help clarify the dose–response relation between physical activity and health. Wearable monitors that provide feedback to users have also been used in longitudinal interventions to motivate research participants and to assess their compliance with program goals. In the third section, future directions for research in physical activity monitoring are discussed. It is likely that new developments in wearable monitors will lead to greater accuracy and improved ease-of-use. (paper)

  2. Keep Taking the Tablets? Assessing the Use of Tablet Devices in Learning and Teaching Activities in the Further Education Sector

    Science.gov (United States)

    Fabian, Khristin; MacLean, Donald

    2014-01-01

    This article summarises the methodology and outcomes of an interventionist/action research project to assess the benefits, and potential pitfalls, of the use of mobile devices in learning and teaching activities in a Further Education environment. A bank of 15 tablet devices were purchased and prepared for classroom use. Staff members were…

  3. Proceedings of microwave processing of materials 3

    International Nuclear Information System (INIS)

    Beatty, R.L.

    1992-01-01

    This book contains proceedings of the third MRS Symposium on Microwave Processing of Materials. Topics covered include: Microwave Processing Overviews, Numerical Modeling Techniques, Microwave Processing System Design, Microwave/Plasma Processing, Microwave/Materials Interactions, Microwave Processing of Ceramics, Microwave Processing of Polymers, Microwave Processing of Hazardous Wastes, Microwave NDE Techniques and Dielectric Properties and Measurements

  4. Redox active polymer devices and methods of using and manufacturing the same

    Science.gov (United States)

    Johnson, Paul; Bautista-Martinez, Jose Antonio; Friesen, Cody; Switzer, Elise

    2018-06-05

    The disclosed technology relates generally to apparatus comprising conductive polymers and more particularly to tag and tag devices comprising a redox-active polymer film, and method of using and manufacturing the same. In one aspect, an apparatus includes a substrate and a conductive structure formed on the substrate which includes a layer of redox-active polymer film having mobile ions and electrons. The conductive structure further includes a first terminal and a second terminal configured to receive an electrical signal therebetween, where the layer of redox-active polymer is configured to conduct an electrical current generated by the mobile ions and the electrons in response to the electrical signal. The apparatus additionally includes a detection circuit operatively coupled to the conductive structure and configured to detect the electrical current flowing through the conductive structure.

  5. Recent advances in processing and applications of microwave ferrites

    International Nuclear Information System (INIS)

    Harris, Vincent G.; Geiler, Anton; Chen Yajie; Yoon, Soack Dae; Wu Mingzhong; Yang, Aria; Chen Zhaohui; He Peng; Parimi, Patanjali V.; Zuo Xu; Patton, Carl E.; Abe, Manasori; Acher, Olivier

    2009-01-01

    Next generation magnetic microwave devices will be planar, smaller, weigh less, and perform well beyond the present state-of-the-art. For this to become a reality advances in ferrite materials must first be realized. These advances include self-bias magnetization, tunability of the magnetic anisotropy, low microwave loss, and volumetric and weight reduction. To achieve these goals one must turn to novel materials processing methods. Here, we review recent advances in the processing of microwave ferrites. Attention is paid to the processing of ferrite films by pulsed laser deposition, liquid phase epitaxy, spin spray ferrite plating, screen printing, and compaction of quasi-single crystals. Conventional and novel applications of ferrite materials, including microwave non-reciprocal passive devices, microwave signal processing, negative index metamaterial-based electronics, and electromagnetic interference suppression are discussed.

  6. Microwave Accelerated Green Synthesis of Stable Silver Nanoparticles with Eucalyptus globulus Leaf Extract and Their Antibacterial and Antibiofilm Activity on Clinical Isolates.

    Directory of Open Access Journals (Sweden)

    Khursheed Ali

    Full Text Available A simple and rapid microwave assisted method of green synthesis of silver nanoparticles (AgNPs was developed using aqueous leaf extract of Eucalyptus globulus(ELE, and their antibacterial and antibiofilm potential investigated. With this aim, the aqueous solutions of ELE and AgNO3(1 mM were mixed (1:4 v/v, and microwave irradiated at 2450 Mhz, for 30 sec. The instant color change of the ELE-AgNO3 mixture from pale yellow to dark brown indicated ELE-AgNPs synthesis. The intensity of peak at 428 nm in UV-Vis spectra, due to the surface plasmon resonance of AgNPs, varied with the amount of ELE, AgNO3 concentration, pH and time of incubation. The biosynthesized ELE-AgNPs were characterized by UV-visible spectroscopy, XRD, TEM, SEM-EDX, FTIR and TGA analyses. The size of ELE-AgNPs was determined to be in range of 1.9-4.3 nm and 5-25 nm, with and without microwave treatment, respectively. SEM exhibited the capping of AgNPs with the ELE constituents, and validated by FTIR analysis. The FTIR data revealed the presence of plant organic constituents and metabolites bound to ELE-AgNPs, which contributes for their stability. The antimicrobial activity of ELE-AgNPs was assessed by growth and biofilm inhibition of extended spectrum β-lactamase (ESBL producing Pseudomonas aeruginosa, Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA and methicillin-sensitive Staphylococcus aureus (MSSA clinical bacterial isolates. The results demonstrated that S. aureus were more sensitive to ELE-AgNPs than E. coli and P. aeruginosa. MRSA exhibited higher sensitive than MSSA, whereas P. aeruginosa were more sensitive than E. coli to ELE-AgNPs treatment. Also, significant (83 ± 3% and 84 ± 5% biofilm inhibition was observed in case of S. aureus and P. aeruginosa, respectively. The results elucidated environmentally friendly, economical and quick method for production of colloidal bio-functionalized ELE-AgNPs, for effectual clinical applications, as broad

  7. Field Prototype of the ENEA Neutron Active Interrogation Device for the Detection of Dirty Bombs

    Directory of Open Access Journals (Sweden)

    Nadia Cherubini

    2016-10-01

    Full Text Available The Italian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA Neutron Active Interrogation (NAI device is a tool designed to improve CBRNE defense. It is designed to uncover radioactive and nuclear threats including those in the form of Improvised Explosive Devices (IEDs, the so-called “dirty bombs”. The NAI device, at its current development stage, allows to detect 6 g of 235U hidden in a package. It is easily transportable, light in weight, and with a real-time response. Its working principle is based on two stages: (1 an “active” stage in which neutrons are emitted by a neutron generator to interact with the item under inspection, and (2 a “passive” stage in which secondary neutrons are detected originating a signal that, once processed, allows recognition of the offence. In particular, a clear indication of the potential threat is obtained by a dedicated software based on the Differential Die-Away Time Analysis method.

  8. Emergency response activities and the collection of damaged radiation devices in the war areas of Croatia

    International Nuclear Information System (INIS)

    Subasic, D.; Schaller, A.

    1998-01-01

    Several kinds of devices containing sources of ionizing radiation had been in use in the areas of Croatia which were affected by the recent war, principally in industrial and medical applications. The greater share of these devices was constituted by 151 radioactive lightning conductors with a maximum individual activity of 19.5 GBq and some 8300 smoke detectors. In the destruction caused by the war, some of these devices were damaged, destroyed or lost. The actions undertaken to retrieve them and their sources are described, as well as the experience gained and lessons learned. The importance of a well organized national regulatory system is underscored as a precondition for the efficient identification and safe recovery of radiation sources lying amidst the ruins in the area affected by the war. The experience gained in these actions may be applicable to similar situations caused by natural disasters such as earthquakes, floods, hurricanes, etc. and of particular interest to regulatory authorities for the drawing up of emergency preparedness plans. (author)

  9. Use of a consumer market activity monitoring and feedback device improves exercise capacity and activity levels in COPD.

    Science.gov (United States)

    Caulfield, Brian; Kaljo, Indira; Donnelly, Seamas

    2014-01-01

    COPD is associated with a gradual decline in physical activity, which itself contributes to a worsening of the underlying condition. Strategies that improve physical activity levels are critical to halt this cycle. Wearable sensor based activity monitoring and persuasive feedback might offer a potential solution. However it is not clear just how much intervention might be needed in this regard - i.e. whether programmes need to be tailored specifically for the target clinical population or whether more simple activity monitoring and feedback solutions, such as that offered in consumer market devices, might be sufficient. This research was carried out to investigate the impact of 4 weeks of using an off the shelf consumer market activity monitoring and feedback application on measures of physical activity, exercise capacity, and health related quality of life in a population of 10 Stage I and II COPD patients. Results demonstrate a significant and positive effect on exercise capacity (measured using a 6-minute walk test) and activity levels (measured in terms of average number of steps per hour) yet no impact on health related quality of life (St Georges Respiratory Disease Questionnaire).

  10. A data-driven and physics-based single-pass retrieval of active-passive microwave covariation and vegetation parameters for the SMAP mission

    Science.gov (United States)

    Entekhabi, D.; Jagdhuber, T.; Das, N. N.; Baur, M.; Link, M.; Piles, M.; Akbar, R.; Konings, A. G.; Mccoll, K. A.; Alemohammad, S. H.; Montzka, C.; Kunstmann, H.

    2016-12-01

    The active-passive soil moisture retrieval algorithm of NASA's SMAP mission depends on robust statistical estimation of active-passive covariation (β) and vegetation structure (Γ) parameters in order to provide reliable global measurements of soil moisture on an intermediate level (9km) compared to the native resolution of the radiometer (36km) and radar (3km) instruments. These parameters apply to the SMAP radiometer-radar combination over the period of record that was cut short with the end of the SMAP radar transmission. They also apply to the current SMAP radiometer and Sentinel 1A/B radar combination for high-resolution surface soil moisture mapping. However, the performance of the statistically-based approach is directly dependent on the selection of a representative time frame in which these parameters can be estimated assuming dynamic soil moisture and stationary soil roughness and vegetation cover. Here, we propose a novel, data-driven and physics-based single-pass retrieval of active-passive microwave covariation and vegetation parameters for the SMAP mission. The algorithm does not depend on time series analyses and can be applied using minimum one pair of an active-passive acquisition. The algorithm stems from the physical link between microwave emission and scattering via conservation of energy. The formulation of the emission radiative transfer is combined with the Distorted Born Approximation of radar scattering for vegetated land surfaces. The two formulations are simultaneously solved for the covariation and vegetation structure parameters. Preliminary results from SMAP active-passive observations (April 13th to July 7th 2015) compare well with the time-series statistical approach and confirms the capability of this method to estimate these parameters. Moreover, the method is not restricted to a given frequency (applies to both L-band and C-band combinations for the radar) or incidence angle (all angles and not just the fixed 40° incidence

  11. Active functional devices using parity-time symmetry optics (Conference Presentation)

    Science.gov (United States)

    Brac de la Perriere, Vincent; Benisty, Henri; Ramdane, Abderrahim; Lupu, Anatole

    2017-05-01

    The progress of nanotechnologies has triggered the emergence of many photonic artificial structures: photonic crystals, metamaterials, plasmonic resonators. Recently the intriguing class of PT-symmetric devices, referring to Parity-Time symmetry [1] has attracted much attention. The characteristic feature of PT-symmetry is that the structures' refractive index profile is complex-valued due to the presence of alternating gain and loss regions in the system. Apart from fundamental research motivations, the tremendous interest in these artificial systems is strongly driven by the practical outcomes expected to foster a new generation of tunable, reconfigurable and non-reciprocal devices. The principle of gain-loss modulation lying in the heart of PT-symmetry optics enables a range of innovative solutions in the field of integrated optics at 1.5μm [2-7]. By using PT-symmetric coupled waveguides and Bragg reflectors as fundamental building blocks, it is possible to build a wide variety of functional optical devices. The PT-symmetry principle provides an alternative way for the realization of active devices that could become functional in a new platform for integrated optics. For instance one major bottleneck of the III-V/Si hybrid integration approach is that each type of active devices (laser, modulator, etc) requires a specific composition of III-V semiconductor alloy, involving a variety of (re)growth challenges. The advantage of the PT-symmetry solution is that the fabrication of all these devices can be done with a single stack of III-V semiconductor alloys that greatly simplifies the technological process. The aim of the current contribution is to provide a survey of the most promising applications of PT-symmetry in photonics with a particular emphases on the transition from theoretical concepts to experimental devices. The intention is to draw attention to the risks and issues related to the practical implementation that are most often overlooked in the basic

  12. The use of active personal dosemeters as a personal monitoring device: Comparison with TL dosimetry

    International Nuclear Information System (INIS)

    Boziari, A.; Koukorava, C.; Carinou, E.; Hourdakis, C. J.; Kamenopoulou, V.

    2011-01-01

    The use of active personal dosemeters (APDs) not only as a warning device but also, in some cases, as an official and hence stand-alone dosemeter is rapidly increasing. A comparison in terms of dose, energy and angle dependence, among different types of APD and a routinely used whole-body thermoluminescence dosemeter (TLD) has been performed. Significant differences were found between the TLD readings and mainly some not commonly used APDs. The importance of choosing the best adapted APD according to the radiation field characteristics is pointed out. (authors)

  13. Integrated microwave photonics for phase modulated systems

    NARCIS (Netherlands)

    Marpaung, D.A.I.; Roeloffzen, C.G.H.

    2012-01-01

    For the last 25 years, microwave photonic (MWP) systems and links have relied almost exclusively on discrete optoelectronic devices, standard optical fibers and fiber-based components. With this concept, various functionalities like RF signal generation, distribution, processing and analysis have

  14. Microwave non-contact imaging of subcutaneous human body tissues.

    Science.gov (United States)

    Kletsov, Andrey; Chernokalov, Alexander; Khripkov, Alexander; Cho, Jaegeol; Druchinin, Sergey

    2015-10-01

    A small-size microwave sensor is developed for non-contact imaging of a human body structure in 2D, enabling fitness and health monitoring using mobile devices. A method for human body tissue structure imaging is developed and experimentally validated. Subcutaneous fat tissue reconstruction depth of up to 70 mm and maximum fat thickness measurement error below 2 mm are demonstrated by measurements with a human body phantom and human subjects. Electrically small antennas are developed for integration of the microwave sensor into a mobile device. Usability of the developed microwave sensor for fitness applications, healthcare, and body weight management is demonstrated.

  15. Comparison of home and away-from-home physical activity using accelerometers and cellular network-based tracking devices.

    Science.gov (United States)

    Ramulu, Pradeep Y; Chan, Emilie S; Loyd, Tara L; Ferrucci, Luigi; Friedman, David S

    2012-08-01

    Measuring physical at home and away from home is essential for assessing health and well-being, and could help design interventions to increase physical activity. Here, we describe how physical activity at home and away from home can be quantified by combining information from cellular network-based tracking devices and accelerometers. Thirty-five working adults wore a cellular network-based tracking device and an accelerometer for 6 consecutive days and logged their travel away from home. Performance of the tracking device was determined using the travel log for reference. Tracking device and accelerometer data were merged to compare physical activity at home and away from home. The tracking device detected 98.6% of all away-from-home excursions, accurately measured time away from home and demonstrated few prolonged signal drop-out periods. Most physical activity took place away from home on weekdays, but not on weekends. Subjects were more physically active per unit of time while away from home, particularly on weekends. Cellular network-based tracking devices represent an alternative to global positioning systems for tracking location, and provide information easily integrated with accelerometers to determine where physical activity takes place. Promoting greater time spent away from home may increase physical activity.

  16. Protein-coated pH-responsive gold nanoparticles: Microwave-assisted synthesis and surface charge-dependent anticancer activity

    Directory of Open Access Journals (Sweden)

    Dickson Joseph

    2014-09-01

    Full Text Available The biocompatibility and ease of functionalization of gold nanoparticles underlie significant potential in biotechnology and biomedicine. Eight different proteins were examined in the preparation of gold nanoparticles (AuNPs in aqueous medium under microwave irradiation. Six of the proteins resulted in the formation of AuNPs. The intrinsic pH of the proteins played an important role in AuNPs with strong surface plasmon bands. The hydrodynamic size of the nanoparticles was larger than the values observed by TEM and ImageJ. The formation of a protein layer on the AuNPs accounts for this difference. The AuNPs exhibited sensitivity towards varying pH conditions, which was confirmed by determining the difference in the isoelectric points studied by using pH-dependent zeta potential titration. Cytotoxicity studies revealed anticancerous effects of the AuNPs at a certain micromolar concentration by constraining the growth of cancer cells with different efficacies due to the use of different proteins as capping agents. The positively charged AuNPs are internalized by the cells to a greater level than the negatively charged AuNPs. These AuNPs synthesized with protein coating holds promise as anticancer agents and would help in providing a new paradigm in area of nanoparticles.

  17. Combination microwave ovens: an innovative design strategy.

    Science.gov (United States)

    Tinga, Wayne R; Eke, Ken

    2012-01-01

    Reducing the sensitivity of microwave oven heating and cooking performance to load volume, load placement and load properties has been a long-standing challenge for microwave and microwave-convection oven designers. Conventional design problem and solution methods are reviewed to provide greater insight into the challenge and optimum operation of a microwave oven after which a new strategy is introduced. In this methodology, a special load isolating and energy modulating device called a transducer-exciter is used containing an iris, a launch box, a phase, amplitude and frequency modulator and a coupling plate designed to provide spatially distributed coupling to the oven. This system, when applied to a combined microwave-convection oven, gives astounding performance improvements to all kinds of baked and roasted foods including sensitive items such as cakes and pastries, with the only compromise being a reasonable reduction in the maximum available microwave power. Large and small metal utensils can be used in the oven with minimal or no performance penalty on energy uniformity and cooking results. Cooking times are greatly reduced from those in conventional ovens while maintaining excellent cooking performance.

  18. Computerized portable microwave hyperthermia quality assurance kit

    International Nuclear Information System (INIS)

    Cheung, A.Y.; Neyzari, A.

    1985-01-01

    A computerized quality assurance kit to provide precise measurement and calibration of microwave power and temperature, as well as capabilities to map SAR (Specific absorption rate) distribution in phantoms; and survey of hazardous microwave leakage has been designed. The kit is also capable of performing corelation studies on the relationship between SAR and net microwave power delivered at various anatomical sites. The kit consists of a portable microcomputer, a time-multiplexed A/D converter, a 4-channel dual directional microwave power monitor, a 4-channel thin-wire thermocouple thermometry system, an electronic thermal calibrator, a microwave leakage hazard survey meter, and a dynamic phantom tank for dosimetric analysis. Comparative performance studies were made against NBS-traceable power and temperature standards, non-perturbing optical temperature sensors, and established power and temperature measurement devices. The test results indicate that this instrument is providing its user with measurement accuracy of 0.1 0 C in temperature, 10% accuracy in power. The thin-wire thermocouple, with computer assisted error compensation, performs equally well in a strong microwave field in comparison with non-perturbing optical temperature sensors

  19. Microwave SQUID multiplexer demonstration for cosmic microwave background imagers

    Science.gov (United States)

    Dober, B.; Becker, D. T.; Bennett, D. A.; Bryan, S. A.; Duff, S. M.; Gard, J. D.; Hays-Wehle, J. P.; Hilton, G. C.; Hubmayr, J.; Mates, J. A. B.; Reintsema, C. D.; Vale, L. R.; Ullom, J. N.

    2017-12-01

    Key performance characteristics are demonstrated for the microwave superconducting quantum interference device (SQUID) multiplexer (μmux) coupled to transition edge sensor (TES) bolometers that have been optimized for cosmic microwave background (CMB) observations. In a 64-channel demonstration, we show that the μmux produces a white, input referred current noise level of 29 pA/ √{H z } at a microwave probe tone power of -77 dB, which is well below the expected fundamental detector and photon noise sources for a ground-based CMB-optimized bolometer. Operated with negligible photon loading, we measure 98 pA/ √{H z } in the TES-coupled channels biased at 65% of the sensor normal resistance. This noise level is consistent with that predicted from bolometer thermal fluctuation (i.e., phonon) noise. Furthermore, the power spectral density is white over a range of frequencies down to ˜100 mHz, which enables CMB mapping on large angular scales that constrain the physics of inflation. Additionally, we report cross-talk measurements that indicate a level below 0.3%, which is less than the level of cross-talk from multiplexed readout systems in deployed CMB imagers. These measurements demonstrate the μmux as a viable readout technique for future CMB imaging instruments.

  20. Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands.

    Science.gov (United States)

    Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

    2016-06-21

    The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich's flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.

  1. Lithographically patterned thin activated carbon films as a new technology platform for on-chip devices.

    Science.gov (United States)

    Wei, Lu; Nitta, Naoki; Yushin, Gleb

    2013-08-27

    Continuous, smooth, visibly defect-free, lithographically patterned activated carbon films (ACFs) are prepared on the surface of silicon wafers. Depending on the synthesis conditions, porous ACFs can either remain attached to the initial substrate or be separated and transferred to another dense or porous substrate of interest. Tuning the activation conditions allows one to change the surface area and porosity of the produced carbon films. Here we utilize the developed thin ACF technology to produce prototypes of functional electrical double-layer capacitor devices. The synthesized thin carbon film electrodes demonstrated very high capacitance in excess of 510 F g(-1) (>390 F cm(-3)) at a slow cyclic voltammetry scan rate of 1 mV s(-1) and in excess of 325 F g(-1) (>250 F cm(-3)) in charge-discharge tests at an ultrahigh current density of 45,000 mA g(-1). Good stability was demonstrated after 10,000 galvanostatic charge-discharge cycles. The high values of the specific and volumetric capacitances of the selected ACF electrodes as well as the capacity retention at high current densities demonstrated great potential of the proposed technology for the fabrication of various on-chip devices, such as micro-electrochemical capacitors.

  2. An active interlock system for the NSLS x-ray ring insertion devices

    International Nuclear Information System (INIS)

    Nawrocky, R.J.; Biscardi, R.; Dabrowski, J.; Flannigan, J.; Ramamoorthy, S.; Rothman, J.; Smith, J.; So, I.; Thomas, M.; Decker, G.

    1991-01-01

    This paper describes the design and operation of an active interlock system which has been installed in the NSLS X-ray electron storage ing to protect the vacuum chamber from thermal damage by mis-steered high power photon beams from insertion devices (IDs). the system employs active beam position detectors to monitor beam motion in the ID straight sections and solid state logic circuitry to ''dump'' the stored beam in the event of a fault condition by interrupting the rf. To ensure a high degree of reliability, redundancy and continuous automatic checking has been incorporated into the design. Overall system integrity is checked periodically with beam at safe levels of beam current. 2 refs., 3 figs

  3. Application of an active device for helicopter noise reduction in JAXA

    International Nuclear Information System (INIS)

    Saito, Shigeru; Kobiki, Noboru; Tanabe, Yasutada

    2010-01-01

    Important issues in noise problems for current helicopters are described. An active tab (AT) was developed as a new active device for noise/vibration reduction under research cooperation between Japan Aerospace Exploration Agency (JAXA) and Kawada Industries, Inc. The wind tunnel test was conducted in order to investigate the effectiveness of the AT on the aeroacoustic characteristics of a helicopter. From the wind tunnel test, the capability of reducing blade vortex interaction (BVI) noise by an AT was verified. A new control law using instantaneous pressure change on a blade during BVI phenomena was introduced and applied to the wind tunnel testing. This new control law shows reasonable controllability for helicopter noise reduction. Furthermore, in order to analyze noise characteristics, the advanced computational fluid dynamics (CFD) code named JAXA o v3d was developed in JAXA and extended to include CFD-CSD (computational structure dynamics) coupling by using the beam theory for blade deformation. (invited paper)

  4. Predicting physical activity energy expenditure in wheelchair users with a multisensor device.

    Science.gov (United States)

    Nightingale, T E; Walhin, J P; Thompson, D; Bilzon, J L J

    2015-01-01

    To assess the error in predicting physical activity energy expenditure (PAEE), using a multisensor device in wheelchair users, and to examine the efficacy of using an individual heart rate calibration (IC) method. 15 manual wheelchair users (36±10 years, 72±11 kg) completed 10 activities: resting, folding clothes, wheelchair propulsion on a 1% gradient (3456 and 7 km/h) and propulsion at 4 km/h (with an additional 8% of body mass, 2% and 3% gradient) on a motorised wheelchair treadmill. Criterion PAEE was measured using a computerised indirect calorimetry system. Participants wore a combined accelerometer and heart rate monitor (Actiheart). They also performed an incremental arm crank ergometry test to exhaustion which permitted retrospective individual calibration of the Actiheart for the activity protocol. Linear regression analysis was conducted between criterion (indirect calorimetry) and estimated PAEE from the Actiheart using the manufacturer's proprietary algorithms (group calibration, GC) or IC. Bland-Altman plots were used and mean absolute error was calculated to assess the agreement between criterion values and estimated PAEE. Predicted PAEE was significantly (p<0.01) correlated with criterion PAEE (GC, r=0.76 and IC, r=0.95). The absolute bias ±95% limits of agreement were 0.51±3.75 and -0.22±0.96 kcal/min for GC and IC, respectively. Mean absolute errors across the activity protocol were 51.4±38.9% using GC and 16.8±15.8% using IC. PAEE can be accurately and precisely estimated using a combined accelerometer and heart rate monitor device, with integration of an IC. Interindividual variance in cardiovascular function and response to exercise is high in this population. Therefore, in manual wheelchair users, we advocate the use of an IC when using the Actiheart to predict PAEE.

  5. Microwave-Assisted Combustion Synthesis of Nano Iron Oxide/Iron-Coated Activated Carbon, Anthracite, Cellulose Fiber, and Silica, with Arsenic Adsorption Studies

    Directory of Open Access Journals (Sweden)

    Mallikarjuna N. Nadagouda

    2011-01-01

    Full Text Available Combustion synthesis of iron oxide/iron coated carbons such as activated carbon, anthracite, cellulose fiber, and silica is described. The reactions were carried out in alumina crucibles using a Panasonic kitchen microwave with inverter technology, and the reaction process was completed within a few minutes. The method used no additional fuel and nitrate, which is present in the precursor itself, to drive the reaction. The obtained samples were then characterized with X-ray mapping, scanning electron microscopy (SEM, energy dispersive X-ray analysis (EDS, selected area diffraction pattern (SAED, transmission electron microscopy (TEM, X-ray diffraction (XRD, and inductively coupled plasma (ICP spectroscopy. The size of the iron oxide/iron nanoparticle-coated activated carbon, anthracite, cellulose fiber, and silica samples were found to be in the nano range (50–400 nm. The iron oxide/iron nanoparticles mostly crystallized into cubic symmetry which was confirmed by SAED. The XRD pattern indicated that iron oxide/iron nano particles existed in four major phases. That is, γ-Fe2O3, α-Fe2O3, Fe3O4, and Fe. These iron-coated activated carbon, anthracite, cellulose fiber, and silica samples were tested for arsenic adsorption through batch experiments, revealing that few samples had significant arsenic adsorption.

  6. Biology-Oriented Syntheses (BIOS) of Novel Santonic-1,3,4-oxadiazole Derivatives under Microwave-Irradiation and their Antimicrobial Activity

    International Nuclear Information System (INIS)

    Salar, U.; Khan, K. M.; Naz, F.; Siddiqui, N. I.

    2015-01-01

    Novel 2-thio substituted 1,3,4-oxadiazole derivatives of santonic acid (13-18) were synthesized. The synthesis of these derivatives was comprised of six steps which start from the basic hydrolysis of santonin 1 to the santoninic acid 2 followed by in situ rearrangement of 2 into santonic acid 3. Santonic acid 3 was then converted into its acyl imidazole derivative 4 followed by hydrazinolysis to give santonic carbohydrazide 5 which was further converted into santonic-1,3,4-oxadiazole-2-thiol 6. Santonic-1,3,4-oxadiazole-2-thiol 6 was alkylated to afford 2-thio substituted 1,3,4-oxadiazole derivatives of santonic acid (13-18). All the synthetic steps were carried out under microwave irradiation in controlled parameters. Compounds 13-18 along with intervening intermediates 5 and 6 were evaluated for their antimicrobial potential. Compound 14 showed appreciably good activity against Staphylococcus epidermidis. On the other hand compounds 6 and 17 demonstrated good activity against Escherichia coli and Shigella flexeneri, respectively. Compound 6 showed good antifungal activity. The synthesized compounds were characterized by different spectroscopy techniques. (author)

  7. Microwave heating application in calcination and SYNROC formation

    International Nuclear Information System (INIS)

    Ambashta, R.D.; Wattal, P.K.; Malav, R.K.; Mallik, G.K.

    2006-01-01

    Microwave for calcination of titanate based ceramic wasteform (SYNROC) is being reported for the first time in this paper. Although major constituents in SYNROC were non microwave active, the combination with microwave active constituents rendered the mixture calcinable. Calcine was sintered at 1150 degC under hot uniaxial conditions at an applied pressure of ∼30 MPa. XRD shows presence of major phases of SYNROC in the compacted sample. (author)

  8. Engineering of kinase-based protein interacting devices: active expression of tyrosine kinase domains

    KAUST Repository

    Diaz Galicia, Miriam Escarlet

    2018-05-01

    Protein-protein interactions modulate cellular processes in health and disease. However, tracing weak or rare associations or dissociations of proteins is not a trivial task. Kinases are often regulated through interaction partners and, at the same time, themselves regulate cellular interaction networks. The use of kinase domains for creating a synthetic sensor device that reads low concentration protein-protein interactions and amplifies them to a higher concentration interaction which is then translated into a FRET (Fluorescence Resonance Energy Transfer) signal is here proposed. To this end, DNA constructs for interaction amplification (split kinases), positive controls (intact kinase domains), scaffolding proteins and phosphopeptide - SH2-domain modules for the reading of kinase activity were assembled and expression protocols for fusion proteins containing Lyn, Src, and Fak kinase domains in bacterial and in cell-free systems were optimized. Also, two non-overlapping methods for measuring the kinase activity of these proteins were stablished and, finally, a protein-fragment complementation assay with the split-kinase constructs was tested. In conclusion, it has been demonstrated that features such as codon optimization, vector design and expression conditions have an impact on the expression yield and activity of kinase-based proteins. Furthermore, it has been found that the defined PURE cell-free system is insufficient for the active expression of catalytic kinase domains. In contrast, the bacterial co-expression with phosphatases produced active kinase fusion proteins for two out of the three tested Tyrosine kinase domains.

  9. Energy-Efficient Real-Time Human Activity Recognition on Smart Mobile Devices

    Directory of Open Access Journals (Sweden)

    Jin Lee

    2016-01-01

    Full Text Available Nowadays, human activity recognition (HAR plays an important role in wellness-care and context-aware systems. Human activities can be recognized in real-time by using sensory data collected from various sensors built in smart mobile devices. Recent studies have focused on HAR that is solely based on triaxial accelerometers, which is the most energy-efficient approach. However, such HAR approaches are still energy-inefficient because the accelerometer is required to run without stopping so that the physical activity of a user can be recognized in real-time. In this paper, we propose a novel approach for HAR process that controls the activity recognition duration for energy-efficient HAR. We investigated the impact of varying the acceleration-sampling frequency and window size for HAR by using the variable activity recognition duration (VARD strategy. We implemented our approach by using an Android platform and evaluated its performance in terms of energy efficiency and accuracy. The experimental results showed that our approach reduced energy consumption by a minimum of about 44.23% and maximum of about 78.85% compared to conventional HAR without sacrificing accuracy.

  10. Optical-Microwave Interactions in Semiconductor Devices.

    Science.gov (United States)

    1981-03-01

    Interdigital Photoconductors ( IDPC ) ......... ..... 112 G. Conclusions.. ....... .. 120 6 CONCLUSIONS AND RECOMMENDATIONS FOR FUTURE WORK . 121...The detector developed at the Hughes Research Laboratories ( IDPC ) involves placing an interdigital metal electrode 53- 5 5 structure on top of a F...easier to perform with the IDPC detector. We believe the interdigital photoconductive detector has many advantages over existing detectors. First, the

  11. Microwave and accelerator research. Final report on Grant DE-FG02-92ER40731

    International Nuclear Information System (INIS)

    Nation, John A.

    2002-01-01

    This report summarizes the main technical objectives and accomplishments during the life of the grant, and concludes with data on publications describing the research. The main activity was the development of very high power microwave sources, initially in X-band, and recent initial work on a Ka band TWT amplifier. There was additional activity on ferroelectric emitters. Highlights include the following: (1) The development of a relatively broad band microwave source yielding approx. 75 MW power at a power efficiency of 54% and an energy conversion efficiency of 43%. (2) The development of a ferroelectric cathode electron gun which yielded a beam current of up to 350 A at 500 kV. The device was shown to operate satisfactorily at a low repetition rate, limited by the available power supplies. The final beam power obtained exceeds that achieved elsewhere by several orders of magnitude. The gun development achieved was shown to give an electron beam suitable for high power X-band microwave sources with the demonstration of a 5-MW tunable X-band TWT single-stage amplifier. (3) Work was initiated on a Ka-Band TWT amplifier. Gains of over 30 dB were achieved at peak output powers of about 4 MW. Appendices include two submitted papers: Symmetric and asymmetric mode interaction in high-power traveling wave amplifiers: experiments and theory and High power microwave generation using a ferroelectric cathode electron gun

  12. Clip-on wireless wearable microwave sensor for ambulatory cardiac monitoring.

    Science.gov (United States)

    Fletcher, Richard R; Kulkarni, Sarang

    2010-01-01

    We present a new type of non-contact sensor for use in ambulatory cardiac monitoring. The sensor operation is based on a microwave Doppler technique; however, instead of detecting the heart activity from a distance, the sensor is placed on the patient's chest over the clothing. The microwave sensor directly measures heart movement rather than electrical activity, and is thus complementary to ECG. The primary advantages of the microwave sensor includes small size, light weight, low power, low-cost, and the ability to operate through clothing. We present a sample sensor design that incorporates a 2.4 GHz Doppler circuit, integrated microstrip patch antenna, and microntroller with 12-bit ADC data sampling. The prototype sensor also includes a wireless data link for sending data to a remote PC or mobile phone. Sample data is shown for several subjects and compared to data from a commercial portable ECG device. Data collected from the microwave sensor exhibits a significant amount of features, indicating possible use as a tool for monitoring heart mechanics and detection of abnormalities such as fibrillation and akinesia.

  13. RF Testing Of Microwave Integrated Circuits

    Science.gov (United States)

    Romanofsky, R. R.; Ponchak, G. E.; Shalkhauser, K. A.; Bhasin, K. B.

    1988-01-01

    Fixtures and techniques are undergoing development. Four test fixtures and two advanced techniques developed in continuing efforts to improve RF characterization of MMIC's. Finline/waveguide test fixture developed to test submodules of 30-GHz monolithic receiver. Universal commercially-manufactured coaxial test fixture modified to enable characterization of various microwave solid-state devices in frequency range of 26.5 to 40 GHz. Probe/waveguide fixture is compact, simple, and designed for non destructive testing of large number of MMIC's. Nondestructive-testing fixture includes cosine-tapered ridge, to match impedance wavequide to microstrip. Advanced technique is microwave-wafer probing. Second advanced technique is electro-optical sampling.

  14. Microwave Resonators and Filters

    Science.gov (United States)

    2015-12-22

    1 Microwave Resonators and Filters Daniel E. Oates MIT Lincoln Laboratory 244 Wood St. Lexington, MA 02478 USA Email: oates@ll.mit.edu...explained in other chapters, the surface resistance of superconductors at microwave frequencies can be as much as three orders of magnitude lower than the...resonators and filters in the first edition of this handbook (Z.-Y. Shen 2003) discussed the then state of the art of microwave frequency applications

  15. Preparation of tamarind fruit seed activated carbon by microwave heating for the adsorptive treatment of landfill leachate: A laboratory column evaluation.

    Science.gov (United States)

    Foo, K Y; Lee, L K; Hameed, B H

    2013-04-01

    The preparation of tamarind fruit seed granular activated carbon (TSAC) by microwave induced chemical activation for the adsorptive treatment of semi-aerobic landfill leachate has been attempted. The chemical and physical properties of TSAC were examined. A series of column tests were performed to determine the breakthrough characteristics, by varying the operational parameters, hydraulic loading rate (5-20 mL/min) and adsorbent bed height (15-21 cm). Ammonical nitrogen and chemical oxygen demand (COD), which provide a prerequisite insight into the prediction of leachate quality was quantified. Results illustrated an encouraging performance for the adsorptive removal of ammonical nitrogen and COD, with the highest bed capacity of 84.69 and 55.09 mg/g respectively, at the hydraulic loading rate of 5 mL/min and adsorbent bed height of 21 cm. The dynamic adsorption behavior was satisfactory described by the Thomas and Yoon-Nelson models. The findings demonstrated the applicability of TSAC for the adsorptive treatment of landfill leachate. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Modeling and prediction of extraction profile for microwave-assisted extraction based on absorbed microwave energy.

    Science.gov (United States)

    Chan, Chung-Hung; Yusoff, Rozita; Ngoh, Gek-Cheng

    2013-09-01

    A modeling technique based on absorbed microwave energy was proposed to model microwave-assisted extraction (MAE) of antioxidant compounds from cocoa (Theobroma cacao L.) leaves. By adapting suitable extraction model at the basis of microwave energy absorbed during extraction, the model can be developed to predict extraction profile of MAE at various microwave irradiation power (100-600 W) and solvent loading (100-300 ml). Verification with experimental data confirmed that the prediction was accurate in capturing the extraction profile of MAE (R-square value greater than 0.87). Besides, the predicted yields from the model showed good agreement with the experimental results with less than 10% deviation observed. Furthermore, suitable extraction times to ensure high extraction yield at various MAE conditions can be estimated based on absorbed microwave energy. The estimation is feasible as more than 85% of active compounds can be extracted when compared with the conventional extraction technique. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Multimode drug inducible CRISPR/Cas9 devices for transcriptional activation and genome editing

    Science.gov (United States)

    Lu, Jia; Zhao, Chen; Zhao, Yingze; Zhang, Jingfang; Zhang, Yue; Chen, Li; Han, Qiyuan; Ying, Yue; Peng, Shuai; Ai, Runna; Wang, Yu

    2018-01-01

    Abstract Precise investigation and manipulation of dynamic biological processes often requires molecular modulation in a controlled inducible manner. The clustered, regularly interspaced, short palindromic repeats (CRISPR)/CRISPR associated protein 9 (Cas9) has emerged as a versatile tool for targeted gene editing and transcriptional programming. Here, we designed and vigorously optimized a series of Hybrid drug Inducible CRISPR/Cas9 Technologies (HIT) for transcriptional activation by grafting a mutated human estrogen receptor (ERT2) to multiple CRISPR/Cas9 systems, which renders them 4-hydroxytamoxifen (4-OHT) inducible for the access of genome. Further, extra functionality of simultaneous genome editing was achieved with one device we named HIT2. Optimized terminal devices herein delivered advantageous performances in comparison with several existing designs. They exerted selective, titratable, rapid and reversible response to drug induction. In addition, these designs were successfully adapted to an orthogonal Cas9. HIT systems developed in this study can be applied for controlled modulation of potentially any genomic loci in multiple modes. PMID:29237052

  18. The influence of assistive technology devices on the performance of activities by visually impaired

    Directory of Open Access Journals (Sweden)

    Suzana Rabello

    2014-04-01

    Full Text Available Objective: To establish the influence of assistive technology devices (ATDs on the performance of activities by visually impaired schoolchildren in the resource room. Methods: A qualitative study that comprised observation and an educational intervention in the resource room. The study population comprised six visually impaired schoolchildren aged 12 to 14 years old. The participants were subjected to an eye examination, prescribed ATDs comprising optical and non-optical devices, and provided an orientation on the use of computers. The participants were assessed based on eye/object distance, font size, and time to read a computer screen and printed text. Results: The ophthalmological conditions included corneal opacity, retinochoroiditis, retinopathy of prematurity, aniridia, and congenital cataracts. Far visual acuity varied from 20/200 to 20/800 and near visual acuity from 0.8 to 6 M. Telescopes, spherical lenses, and support magnifying glasses were prescribed. Three out of five participants with low vision after intervention could decrease the font size on the screen computer, and most participants (83.3% reduced their reading time at the second observation session. Relative to the printed text, all the participants with low vision were able to read text written in smaller font sizes and reduced their reading time at the second observation session. Conclusion: Reading skills improved after the use of ATDs, which allowed the participants to perform their school tasks equally to their classmates.

  19. Assessment of a Newly Developed, Active Pneumatic-Driven, Sensorimotor Test and Training Device

    Directory of Open Access Journals (Sweden)

    Wolfram Haslinger

    2014-12-01

    Full Text Available The sensorimotor system (SMS plays an important role in sports and in every day movement. Several tools for assessment and training have been designed. Many of them are directed to specific populations, and have major shortcomings due to the training effect or safety. The aim of the present study was to design and assess a dynamic sensorimotor test and training device that can be adjusted for all levels of performance. The novel pneumatic-driven mechatronic device can guide the trainee, allow independent movements or disrupt the individual with unpredicted perturbations while standing on a platform. The test-reliability was evaluated using intraclass correlation coefficient (ICC. Subjects were required to balance their center of pressure (COP in a target circle (TITC. The time in TITC and the COP error (COPe were recorded for analysis. The results of 22 males and 14 females (23.7 ± 2.6 years showed good to excellent test–retest reliability. The newly designed Active Balance System (ABS was then compared with the Biodex Balance System SD® (BBS. The results of 15 females, 14 males (23.4 ± 1.6 years showed modest correlation in static and acceptable correlation in dynamic conditions, suggesting that ABS could be a reliable and comparable tool for dynamic balance assessments.

  20. Antibacterial Activities of Green Basil (Ocimum Violaceum Essential Oil and Derivatives By MAOS (Microwave Assisted Organic Synthesis Against Staphyllococus Aureus and Escherichia Coli

    Directory of Open Access Journals (Sweden)

    Dwiarso Rubiyanto

    2014-07-01

    Full Text Available Green basil (Ocimum violaceum , Linn. plantis part of the varieties of basil (Ocimum basilicum, Linn.. Green basil essential oil (GBEO contain chemical compounds that have an anti- bacterial activities . Methyl eugenol and methyl chavikol are in green basil oil has the potential to be used as a material which is biologically active. Conversion reaction of the compounds in GBEO with MAOS methods (microwave assisted organic synthesis aims to obtain properties of the main chemical component in a wider sweet basil oil, and are also useful in an attempt to gain more valuable compounds for commercial and higher. The results showed that the optimum reaction conditions on the conversion reaction of compounds in GBEO with MAOS method with ethylene glycol as a solvent is 10 % KF/Al2O3as catalyst and reaction time 3 minutes , while the solvent is glycerol 10 % KF/Al2O3as catalyst and reaction time 2 minutes . Comparison of anti-bacterial activity resulting from this research are : the inhibitory activity to the growth of S. aureus bacteria have the following order : GBEO > green basilEG10-3 > green basil G10-2> amoxicillin with each inhibition zone diameter amounted to 30.7 mm, 21.1 mm, 18.2 mm and 13.4 mm. While the inhibitory activity to the growth of E.coli bacteria are : GBEO> green basil G10-2 >green basil EG10-3 > amoxicillin with each inhibition zone diameter of 21.1 mm, 15.6 mm , 15.2 mm and 7.9 mm . GBEO and its derivatives have minimal inhibitory concentrations below 1.25 %. From the results of the study found that the main derivates obtained are p-methoxy anisaldehyde , caryophyllene oxide , 3-methoxy cinnamaldehyde , humulena oxide and delta cadinol

  1. Advanced microwave processing concepts

    Energy Technology Data Exchange (ETDEWEB)

    Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L. [Oak Ridge National Laboratory, TN (United States)

    1995-05-01

    The purpose of this work is to explore the feasibility of several advanced microwave processing concepts to develop new energy-efficient materials and processes. The project includes two tasks: (1) commercialization of the variable-frequency microwave furnace; and (2) microwave curing of polymer composites. The variable frequency microwave furnace, whose initial conception and design was funded by the AIC Materials Program, will allow us, for the first time, to conduct microwave processing studies over a wide frequency range. This novel design uses a high-power traveling wave tube (TWT) originally developed for electronic warfare. By using this microwave source, one can not only select individual microwave frequencies for particular experiments, but also achieve uniform power densities over a large area by the superposition of many different frequencies. Microwave curing of thermoset resins will be studied because it hold the potential of in-situ curing of continuous-fiber composites for strong, lightweight components. Microwave heating can shorten curing times, provided issues of scaleup, uniformity, and thermal management can be adequately addressed.

  2. The microwave market

    International Nuclear Information System (INIS)

    Bybokas, J.

    1989-01-01

    As superconductors move from the laboratory to the marketplace, it becomes more important for researchers and manufacturers to understand the markets for this technology. The large market for microwave systems represents a major opportunity for high-T c superconductors. Conductor losses are a primary design limitation in conventional microwave systems. The low losses of superconductors at microwave frequencies will allow component designers and system designers to improve their products in many ways. The most important market segments for microwave systems are outlined in this discussion

  3. Thin film-based optically variable security devices: From passive to active

    Science.gov (United States)

    Baloukas, Bill

    Counterfeiting costs the world economy billions of dollars every year. Aside from financial losses, counterfeiting also poses a great threat to the public's safety, for example through the existence of counterfeit passports (terrorism), pharmaceutical products (health hazards) and even airplane parts (safety issues). Optical security devices (OSDs) have therefore played a critical role in the fight against counterfeiting. It is the aim of the present thesis to show that through the use of metamerism and electrochromic materials, new types of active security devices with interesting features can be created; indeed, most present-day devices are passive in nature. I first demonstrate that the addition of metamerism in the design of interference filters can result in innovative features. Different structures which can be used in transmission and/or in reflection are designed, fabricated, and evaluated. The first structures which are presented here are based on a combination of two different metameric interference filters. Possessing widely different transmission spectra, these filters also offer different angular color shifts and, as a result, offer an opportunity of creating hidden image effects. Despite their interesting properties, such metameric devices are shown to be highly illuminant and observer sensitive; that is the color match is lost under most observation conditions. These issues are solved by a simpler structure based on the juxtaposition of an interference filter and a non-iridescent colored material. Throughout this study, I present the design approach, analyze the filters' sensitivity to deposition errors, and evaluate the performance of prototype devices prepared by dual ion beam sputtering. Following my work on passive metameric systems, I then propose to go one step further by implementing an active component using an electrochromic material. This novel concept, which is based on the joint use of a metameric filter and electrochromic device, offers

  4. Optical technology for microwave applications VI and optoelectronic signal processing for phased-array antennas III; Proceedings of the Meeting, Orlando, FL, Apr. 20-23, 1992

    Science.gov (United States)

    Yao, Shi-Kay; Hendrickson, Brian M.

    The following topics related to optical technology for microwave applications are discussed: advanced acoustooptic devices, signal processing device technologies, optical signal processor technologies, microwave and optomicrowave devices, advanced lasers and sources, wideband electrooptic modulators, and wideband optical communications. The topics considered in the discussion of optoelectronic signal processing for phased-array antennas include devices, signal processing, and antenna systems.

  5. Rapid microwave hydrothermal synthesis of ZnGa2O4 with high photocatalytic activity toward aromatic compounds in air and dyes in liquid water

    International Nuclear Information System (INIS)

    Sun Meng; Li Danzhen; Zhang Wenjuan; Chen Zhixin; Huang Hanjie; Li Wenjuan; He Yunhui; Fu Xianzhi

    2012-01-01

    ZnGa 2 O 4 was synthesized from Ga(NO 3 ) 3 and ZnCl 2 via a rapid and facile microwave-assisted hydrothermal method. The photocatalytic properties of the as-prepared ZnGa 2 O 4 were evaluated by the degradation of pollutants in air and aqueous solution under ultraviolet (UV) light illumination. The results demonstrated that ZnGa 2 O 4 had exhibited efficient photocatalytic activities higher than that of commercial P25 (Degussa Co.) in the degradation of benzene, toluene, and ethylbenzene, respectively. In the liquid phase degradation of dyes (methyl orange, Rhodamine B, and methylene blue), ZnGa 2 O 4 has also exhibited remarkable activities higher than that of P25. After 32 min of UV light irradiation, the decomposition ratio of methyl orange (10 ppm, 150 mL) over ZnGa 2 O 4 (0.06 g) was up to 99%. The TOC tests revealed that the mineralization ratio of MO (10 ppm, 150 mL) was 88.1% after 90 min of reaction. A possible mechanism of the photocatalysis over ZnGa 2 O 4 was also proposed. - Graphical abstract: In the degradation of RhB under UV light irradiation, ZnGa 2 O 4 had exhibited efficient photo-activity, and after only 24 min of irradiation the decomposition ratio was up to 99.8%. Highlights: ► A rapid and facile M–H method to synthesize ZnGa 2 O 4 photocatalyst. ► The photocatalyst exhibits high activity toward benzene and dyes. ► The catalyst possesses more surface hydroxyl sites than TiO 2 (P25). ► Deep oxidation of different aromatic compounds and dyes over catalyst.

  6. Direct-reading type microwave interferometer

    International Nuclear Information System (INIS)

    Matsuura, Kiyokata; Fujita, Junji; Ogata, Atsushi; Haba, Kiichiro.

    1977-10-01

    A new microwave interferometer has been developed and applied to the electron density measurement on JIPP T-II plasma device. The interferometer generates an output voltage proportional to the number of fringe shifts and also output pulses which indicate the change of electron density for the convenience of data processing, where the resolution is a quarter of fringe shift. The principle is based on the digitization of fringe shifts utilizing the phase detection of microwave signals with two-level modulation of source frequency. With this system and 70 GHz microwave source, a change of electron density as rapid as about 2 x 10 13 cm -3 in 1 ms has been measured at the tokamak operation of JIPP T-II. (auth.)

  7. Cavity Microwave Searches for Cosmological Axions

    CERN Multimedia

    CERN. Geneva

    2005-01-01

    The lecture will cover the searches for dark matter axions based on the microwave cavity experiment of Sikivie. The topics will begin with a brief overview of halo dark matter, and the axion as a candidate. The principle of resonant conversion of axions in an external magnetic field will be described, and practical considerations in optimizing the experiment as a signal-to-noise problem. A major focus of the lecture will be the two complementary strategies for ultra-low noise detection of the microwave photons - the "photon-as-wave" approach (i.e. conventional heterojunction amplifiers and soon quantum-limited SQUID devices), and "photon-as-particle" (i.e. Rydberg-atom single-quantum detection). Experimental results will be presented; these experiments have already reached well into the range of sensitivity to exclude plausible axion models, for limited ranges of mass. The lecture will conclude with a discussion of future plans and challenges for the microwave ca...

  8. Activity monitoring using a mHealth device and correlations with psychopathology in patients with chronic schizophrenia.

    Science.gov (United States)

    Shin, Seunghwan; Yeom, Chan-Woo; Shin, Cheolmin; Shin, Jae-Hyun; Jeong, Jae Hoon; Shin, Jung Uk; Lee, Young Ryeol

    2016-12-30

    There are few studies of mobile-Health (mHealth) device application with schizophrenic patients. We aimed to quantitatively assess patient's activity and the relationship between their physical activity and the severity of their psychopathologies. Then we attempted to identify the patients who required intervention and evaluated the feasibility of using the mHealth device. A total of 61 of the 76 available hospitalized patients with chronic schizophrenia who participated in the activity programs were enrolled. They wore a mHealth device for a week to assess their activity (steps/day). The Positive and Negative Syndrome Scale (PANSS) was completed by the subjects. As a result, the positive subscale of the PANSS and the positive and negative factors of the PANSS 5-factor structure showed a predictive value for low levels of physical activity. The group of subjects with a high total PANSS score had a significantly lower level of physical activity than the other groups. In conclusion, physical activity showed a significant association with positive symptoms as well as negative symptoms. The mHealth device showed relatively good feasibility for schizophrenic patients. We should pay more attention to the activity of patients with high PANSS scores. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Qualitative Assessment of an Electronic Activity-Tracking Device: Strengths, Weaknesses, and Considerations in Behavior Change Interventions for Health Educators

    Science.gov (United States)

    Ball, James W.; Bice, Matthew R.; Adkins, Megan M.

    2015-01-01

    Motivating people to engage in regular physical activity (PA) is a constant struggle for many health education professionals. The purchase of activity-tracking devices (Fitbit, Nike Fuel Band, etc…) has been a popular trend in recent years, presumably to assist users to increase their PA. However, limited research has examined consumer feedback…

  10. Plasma source by microwaves: design description

    International Nuclear Information System (INIS)

    Camps, E.; Olea, O.; Andrade, R.; Anguiano, G.

    1992-03-01

    The design of a device for the formation of a plasma with densities of the order of 10 12 cm - 3 and low temperatures (T e ∼ 40 eV) is described. For such purpose it was carried out in the device a microwave discharge (f o = 2.45 GHz) in a resonator of high Q factor, immersed in a static external magnetic field. The device worked in the regime ω ce ≤ ω o /2 (ω ce - cyclotron frequency of the electrons, (ω o = 2 π f o ) where is possible the excitement of non lineal phenomena of waves transformation. (Author)

  11. A monolithic integrated photonic microwave filter

    Science.gov (United States)

    Fandiño, Javier S.; Muñoz, Pascual; Doménech, David; Capmany, José

    2017-02-01

    Meeting the increasing demand for capacity in wireless networks requires the harnessing of higher regions in the radiofrequency spectrum, reducing cell size, as well as more compact, agile and power-efficient base stations that are capable of smoothly interfacing the radio and fibre segments. Fully functional microwave photonic chips are promising candidates in attempts to meet these goals. In recent years, many integrated microwave photonic chips have been reported in different technologies. To the best of our knowledge, none has monolithically integrated all the main active and passive optoelectronic components. Here, we report the first demonstration of a tunable microwave photonics filter that is monolithically integrated into an indium phosphide chip. The reconfigurable radiofrequency photonic filter includes all the necessary elements (for example, lasers, modulators and photodetectors), and its response can be tuned by means of control electric currents. This is an important step in demonstrating the feasibility of integrated and programmable microwave photonic processors.

  12. Radiation emitting devices regulations

    International Nuclear Information System (INIS)

    1970-01-01

    The Radiation Emitting Devices Regulations are the regulations referred to in the Radiation Emitting Devices Act and relate to the operation of devices. They include standards of design and construction, standards of functioning, warning symbol specifications in addition to information relating to the seizure and detention of machines failing to comply with the regulations. The radiation emitting devices consist of the following: television receivers, extra-oral dental x-ray equipment, microwave ovens, baggage inspection x-ray devices, demonstration--type gas discharge devices, photofluorographic x-ray equipment, laser scanners, demonstration lasers, low energy electron microscopes, high intensity mercury vapour discharge lamps, sunlamps, diagnostic x-ray equipment, ultrasound therapy devices, x-ray diffraction equipment, cabinet x-ray equipment and therapeutic x-ray equipment

  13. Treatment of simulated wastewater containing Reactive Red 195 by zero-valent iron/activated carbon combined with microwave discharge electrodeless lamp/sodium hypochlorite.

    Science.gov (United States)

    Fu, Jie; Xu, Zhen; Li, Qing-Shan; Chen, Song; An, Shu-Qing; Zeng, Qing-Fu; Zhu, Hai-Liang

    2010-01-01

    A comparative study of treatment of simulated wastewater containing Reactive Red 195 using zero-valent iron/activated carbon (ZVI/AC), microwave discharge electrodeless lamp/sodium hypochlorite (MDEL/NaClO) and the combination of ZVI/AC-MDEL/NaClO was conducted. The preliminary results showed the two steps method of ZVI/AC-MDEL/NaClO had much higher degradation efficiency than both single steps. The final color removal percentage was nearly up to 100% and the chemical oxygen demand reduction percentage was up to approximately 82%. The effects of operational parameters, including initial pH value of simulated wastewater, ZVI/AC ratio and particle size of ZVI were also investigated. In addition, from the discussion of synergistic effect between ZVI/AC and MEDL/NaClO, we found that in the ZVI/AC-MEDL/NaClO process, ZVI/AC could break the azo bond firstly and then MEDL/NaClO degraded the aromatic amine products effectively. Reversing the order would reduce the degradation efficiency.

  14. Fabrication of a Nano-ZnO/Polyethylene/Wood-Fiber Composite with Enhanced Microwave Absorption and Photocatalytic Activity via a Facile Hot-Press Method

    Directory of Open Access Journals (Sweden)

    Baokang Dang

    2017-11-01

    Full Text Available A polyethylene/wood-fiber composite loaded with nano-ZnO was prepared by a facile hot-press method and was used for the photocatalytic degradation of organic compounds as well as for microwave absorption. ZnO nanoparticles with an average size of 29 nm and polyethylene (PE powders were dispersed on the wood fibers’ surface through a viscous cationic polyacrylamide (CPAM solution. The reflection loss (RL value of the resulting composite was −21 dB, with a thickness of 3.5 mm in the frequency of 17.17 GHz. The PE/ZnO/wood-fiber (PZW composite exhibited superior photocatalytic activity (84% methyl orange degradation within 300 min under UV light irradiation. ZnO nanoparticels (NPs increased the storage modulus of the PZW composite, and the damping factor was transferred to the higher temperature region. The PZW composite exhibited the maximum flexural strength of 58 MPa and a modulus of elasticity (MOE of 9625 MPa. Meanwhile, it also displayed dimensional stability (thickness swelling value of 9%.

  15. Microwave-Assisted Coprecipitation Synthesis of LaCoO3 Nanoparticles and Their Catalytic Activity for Syngas Production by Partial Oxidation of Methane

    Directory of Open Access Journals (Sweden)

    Consuelo Alvarez-Galvan

    2018-04-01

    Full Text Available LaCoO3 perovskite-type oxides were prepared by microwave-assisted coprecipitation route and investigated in the catalytic partial oxidation of methane (CPOM to syngas. This preparation method aims to achieve higher specific surface areas (ssa than soft-chemical methods commonly used in the preparation of engineered materials. In an attempt to accomplish the creation of mesostructured porous LaCoO3, an ionic template such as cetyl trimethyl ammonium bromide has been used as endotemplate in some samples. The influence of pH and the type of precipitating agent has been studied. The materials have been characterized at different levels: morphology has been studied by scanning electron microscopy, textural properties by nitrogen adsorption–desorption at −196°C, structural analysis by X-ray diffraction, surface composition by X-ray photoelectron spectroscopy, thermal stability by thermogravimetric analysis, and carbon formation in spent catalysts by Raman spectroscopy. Structure-activity correlations point out that the precipitating agent has a key role on the morphology and porosity of the resultant oxide, as well as on the average crystalline domain of lanthanum perovskite (catalyst precursor. Thus, the use of ammonium hydroxide as precipitant leads to materials with a higher surface area and a greater ssa of cobalt (per unit mass, improving their catalytic performance for the CPOM reaction. The best catalytic performance was found for the catalyst prepared using ammonium hydroxide as precipitant (pH 9 and without adding CTAB as endotemplate.

  16. Spectroscopic study on interaction between bisphenol A or its degraded solution under microwave irradiation in the presence of activated carbon and human serum albumin

    International Nuclear Information System (INIS)

    Zhang Zhaohong; Xu Danping; Tie Mei; Li Fangyi; Chen Zhonglin; Wang Jie; Gao Wei; Ji Xiaotong; Xu Yao

    2011-01-01

    In this study, the interaction between bisphenol A (BPA) or its degraded solution under microwave irradiation after their adsorption on activated carbon (AC/MW) and human serum albumin (HSA) was investigated by UV-vis and fluorescence spectroscopy techniques. The results showed that BPA could bind to HSA molecule, which could cause the stretch of peptide chains. Also, the degraded BPA solution with a few residues could still interact with HSA. Otherwise, the influences of pH and ionic strength on the interaction were estimated. The fluorescence quenching modes of HSA initiated by BPA at three temperatures (298, 310 and 315 K) were all obtained using Stern-Volmer and Lineweaver-Burk equations. The number of binding sites (n), binding constants (K D ) and energy transfer efficiency (E) were all calculated. The thermodynamic parameters (ΔH, ΔG and ΔS) and binding distances (r) were all measured at the three temperatures, respectively. Synchronous fluorescence spectroscopy was also carried out. - Highlights: →The interaction between bisphenol A (BPA) and human serum albumin (HSA) was investigated. → The interaction between degraded BPA solution and HSA was also studied. → The fluorescence quenching mode of HSA initiated by BPA was obtained. → The number of binding site (n) and binding constant (K D ) and their binding distances (r) between BPA and HSA were calculated.

  17. Microwave-assisted aqueous enzymatic extraction of oil from pumpkin seeds and evaluation of its physicochemical properties, fatty acid compositions and antioxidant activities.

    Science.gov (United States)

    Jiao, Jiao; Li, Zhu-Gang; Gai, Qing-Yan; Li, Xiao-Juan; Wei, Fu-Yao; Fu, Yu-Jie; Ma, Wei

    2014-03-15

    Microwave-assisted aqueous enzymatic extraction (MAAEE) of pumpkin seed oil was performed in this study. An enzyme cocktail comprised of cellulase, pectinase and proteinase (w/w/w) was found to be the most effective in releasing oils. The highest oil recovery of 64.17% was achieved under optimal conditions of enzyme concentration (1.4%, w/w), temperature (44°C), time (66 min) and irradiation power (419W). Moreover, there were no significant variations in physicochemical properties of MAAEE-extracted oil (MAAEEO) and Soxhlet-extracted oil (SEO), but MAAEEO exhibited better oxidation stability. Additionally, MAAEEO had a higher content of linoleic acid (57.33%) than SEO (53.72%), and it showed stronger antioxidant activities with the IC50 values 123.93 and 152.84, mg/mL, according to DPPH radical scavenging assay and β-carotene/linoleic acid bleaching test. SEM results illustrated the destruction of cell walls and membranes by MAAEE. MAAEE is, therefore, a promising and environmental-friendly technique for oil extraction in the food industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Granular activated carbon adsorption and microwave regeneration for the treatment of 2,4,5-trichlorobiphenyl in simulated soil-washing solution

    International Nuclear Information System (INIS)

    Liu Xitao; Yu Gang; Han Wenya

    2007-01-01

    The treatment of 2,4,5-trichlorobiphenyl (PCB29) in simulated soil-washing solution by granular activated carbon (GAC) adsorption and microwave (MW) regeneration was investigated in this study. The PCB29 adsorption process was carried out in a continuous flow adsorption column. After adsorption, the PCB29-loaded GAC was dried at 103 deg. C, and regenerated in a quartz reactor by 2450 MHz MW irradiation at 700 W for 5 min. The efficacy of this procedure was analyzed by determining the rates and amounts of PCB29 adsorbed in successive adsorption/MW regeneration cycles. Effects of the regeneration on the textural properties and the PCB29 adsorption capacity of GAC were examined. It was found that after several adsorption/MW regeneration cycles, the adsorption rate of GAC increased, whereas, the adsorption capacity decreased, which could be explained according to the change of textural properties. Most of the PCB29 adsorbed on GAC was degraded within 3 min under MW irradiation, and the analysis of degradation products by GC-MS demonstrated that PCB29 experienced dechlorination during this treatment

  19. Modified DLC coatings prepared in a large-scale reactor by dual microwave/pulsed-DC plasma-activated chemical vapour deposition

    International Nuclear Information System (INIS)

    Corbella, C.; Bialuch, I.; Kleinschmidt, M.; Bewilogua, K.

    2008-01-01

    Diamond-Like Carbon (DLC) films find abundant applications as hard and protective coatings due to their excellent mechanical and tribological performances. The addition of new elements to the amorphous DLC matrix tunes the properties of this material, leading to an extension of its scope of applications. In order to scale up their production to a large plasma reactor, DLC films modified by silicon and oxygen additions have been grown in an industrial plant of 1m 3 by means of pulsed-DC plasma-activated chemical vapour deposition (PACVD). The use of an additional microwave (MW) source has intensified the glow discharge, partly by electron cyclotron resonance (ECR), accelerating therefore the deposition process. Hence, acetylene, tetramethylsilane (TMS) and hexamethyldisiloxane (HMDSO) constituted the respective gas precursors for the deposition of a-C:H (DLC), a-C:H:Si and a-C:H:Si:O films by dual MW/pulsed-DC PACVD. This work presents systematic studies of the deposition rate, hardness, adhesion, abrasive wear and water contact angle aimed to optimize the technological parameters of deposition: gas pressure, relative gas flow of the monomers and input power. This study has been completed with measures of the atomic composition of the samples. Deposition rates around 1 μm/h, typical for standard processes held in the large reactor, were increased about by a factor 10 when the ionization source has been operated in ECR mode

  20. TiO{sub 2} films obtained by microwave-activated chemical-bath deposition used to improve TiO{sub 2}-conducting glass contact

    Energy Technology Data Exchange (ETDEWEB)

    Zumeta, I.; Gonzalez, B. [Institute for Material Science and Technology, University of Havana, Colina Universitaria, Ciudad Habana 10 400 (Cuba); Ayllon, J.A.; Domenech, X. [Chemistry Department, Autonomous University of Barcelona, 08290 Cerdanyola del Valles (Spain); Vigil, E. [Institute for Material Science and Technology, University of Havana, Colina Universitaria, Ciudad Habana 10 400 (Cuba); Physics Faculty, University of Havana, Colina Universitaria, Ciudad Habana 10 400 (Cuba)

    2009-10-15

    In traditional solar cells, metal-semiconductor contacts used to extract photogenerated carriers are very important. In dye-sensitized solar cells (DSSC) not much attention has been given to contact between the TiO{sub 2} and the transparent conducting glass (TCO), which is used instead of a metal contact to extract electrons. TiO{sub 2} layers obtained by microwave-activated chemical-bath deposition (MW-CBD) are proposed to improve TiO{sub 2} contact to conducting glass. Spectra of incident photon to current conversion efficiency (IPCE) are obtained for two-photoelectrode TiO{sub 2} photoelectrochemical cells. IPCE spectra show higher values when TiO{sub 2} double layer photoelectrodes are used. In these, the first layer or contacting layer is made by MW-CBD. Best results are obtained for double layer photoelectrodes on FTO (SnO{sub 2}:F) as conducting oxide substrate. Modeling of IPCE spectra reveals the importance of electrical contact and electron extraction rate at the TiO{sub 2}/TCO interface. (author)

  1. Microwaves integrated circuits: hybrids and monolithics - fabrication technology

    International Nuclear Information System (INIS)

    Cunha Pinto, J.K. da

    1983-01-01

    Several types of microwave integrated circuits are presented together with comments about technologies and fabrication processes; advantages and disadvantages in their utilization are analysed. Basic structures, propagation modes, materials used and major steps in the construction of hybrid thin film and monolithic microwave integrated circuits are described. Important technological applications are revised and main activities of the microelectronics lab. of the University of Sao Paulo (Brazil) in the field of hybrid and monolithic microwave integrated circuits are summarized. (C.L.B.) [pt

  2. Microwave assisted synthesis of 2-(2-(tetrazolo[1,5-a]quinolin-4-yl-2,3-dihydro-1h-benzo[b][1,4]diazepin-4-yl substituted phenols and evaluation of their antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Ashok Dongamanti

    2016-01-01

    Full Text Available A series of new benzodiazepines 4a-h have been synthesized by Michael addition of chalcones 3a-h with o-phenylenediamine (OPDA in presence of sodium acetate under conventional heating and microwave irradiation. Structures of the newly synthesized benzodiazepines 4a-h have been established on the basis of IR, 1H & 13C NMR and mass spectral data and tested for antimicrobial activity.

  3. Microwave Enhanced Reactive Distillation

    NARCIS (Netherlands)

    Altman, E.

    2011-01-01

    The application of electromagnetic irradiation in form of microwaves (MW) has gathered the attention of the scientific community in recent years. MW used as an alternative energy source for chemical syntheses (microwave chemistry) can provide clear advantages over conventional heating methods in

  4. Integrated microwave photonics

    NARCIS (Netherlands)

    Marpaung, D.A.I.; Roeloffzen, C.G.H.; Heideman, Rene; Leinse, Arne; Sales, S.; Capmany, J.

    2013-01-01

    Microwave photonics (MWP) is an emerging field in which radio frequency (RF) signals are generated, distributed, processed and analyzed using the strength of photonic techniques. It is a technology that enables various functionalities which are not feasible to achieve only in the microwave domain. A

  5. Microwave Breast Imaging Techniques

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Rubæk, Tonny

    2010-01-01

    This paper outlines the applicability of microwave radiation for breast cancer detection. Microwave imaging systems are categorized based on their hardware architecture. The advantages and disadvantages of various imaging techniques are discussed. The fundamental tradeoffs are indicated between...... various requirements to be fulfilled in the design of an imaging system for breast cancer detection and some strategies to overcome these limitations....

  6. MICROWAVES IN ORGANIC SYNTHESIS

    Science.gov (United States)

    The effect of microwaves, a non-ionizing radiation, on organic reactions is described both in polar solvents and under solvent-free conditions. The special applications are highlighted in the context of solventless organic synthesis which involve microwave (MW) exposure of neat r...

  7. Variable frequency microwave heating apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Bible, D.W.; Lauf, R.J.; Johnson, A.C.; Thigpen, L.T.

    1999-10-05

    A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a multi-mode microwave cavity (34) for testing or other selected applications. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a high-power microwave oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34). A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

  8. Comparative Analysis of Chemical Composition, Antioxidant and Antibacterial Activities of Mentha rotundifolia Essential oils from Algeria extracted by microwave and hydrodistillation

    Directory of Open Access Journals (Sweden)

    Nacéra HADDACHE

    2017-04-01

    Full Text Available The essential oil of Mentha rotundifolia (L. Huds growing wild from East Algeria (Naciria at 60Km in East of Algiers obtained by hydrodistillation (HD° and a microwave distillation process (MD have been analysed by means of GC-FID and GC/MS in combination with retention indices. In total, 54 constituents were identified (accounting for 96.7 and 95.6% in HD and MD oils, respectively. The main components were piperitone oxide (25.1 and 29.1% in HD and MD oils, respectively, piperitenone oxide (8.9 – 11.8%, terpinen-4-ol (9.3 – 3.4%, β-caryophyllene (5.4 – 7.3%, allo-aromadendrene (5.3 - 6.4% and Dgermacrène (5.4 – 7.1%. In comparison with HD, MD allows to obtain oil in a very short time, with the reduction of solvent used similar yields, comparable qualities and substantial savings of energy. The antioxidant activity was determined according to the ability of the tested samples to scavenge the free radicals 2,2- diphenyl-1-picrylhydrazyl (DPPH*. The essential oil were slightly active (32.6 and 21.8% in HD and MD oils, respectively comparing with BHT (64.7%. The antibacterial activities of the essential oils indicated that Staphylococcus aureus was the more sensitive strain tested to the oils of Mentha rotundifolia with the strongest inhibition zone 28.3 for HD and 26.5 mm for MO.

  9. Heterodyne detector for measuring the characteristic of elliptically polarized microwaves

    DEFF Research Database (Denmark)

    Leipold, Frank; Nielsen, Stefan Kragh; Michelsen, Susanne

    2008-01-01

    In the present paper, a device is introduced, which is capable of determining the three characteristic parameters of elliptically polarized light (ellipticity, angle of ellipticity, and direction of rotation) for microwave radiation at a frequency of 110 GHz. The device consists of two perpendicu......In the present paper, a device is introduced, which is capable of determining the three characteristic parameters of elliptically polarized light (ellipticity, angle of ellipticity, and direction of rotation) for microwave radiation at a frequency of 110 GHz. The device consists of two...... be calculated. Results from measured and calculated wave characteristics of an elliptically polarized 110 GHz microwave beam for plasma heating launched into the TEXTOR-tokamak experiment are presented. Measurement and calculation are in good agreement. ©2008 American Institute of Physics...

  10. Photoinduced spin polarization and microwave technology

    International Nuclear Information System (INIS)

    Antipov, Sergey; Poluektov, Oleg; Schoessow, Paul; Kanareykin, Alexei; Jing, Chunguang

    2013-01-01

    We report here on studies of optically pumped active microwave media based on various fullerene derivatives, with an emphasis on the use of these materials in microwave electronics. We have investigated a class of optically excited paramagnetic materials that demonstrate activity in the X-band as candidate materials. We found that a particular fullerene derivative, Phenyl-C 61 -butyric acid methyl ester (PCBM), produced the largest electron paramagnetic resonance (EPR) emission signal compared to other organic compounds that have been suggested for use as microwave active materials. We also studied the effects of concentration, temperature, solvent etc. on the activity of the material. In these experiments, EPR studies using a commercial spectrometer were followed up by measurements of an RF signal reflected from a resonator loaded with the PCBM-based material. The activity was directly demonstrated through the change in the quality factor and RF coupling between the resonator and waveguide feed. At the inception of these experiments the primary interest was the development of a microwave PASER. The PASER (particle acceleration by stimulated emission of radiation [1]) is a novel acceleration concept that is based on the direct energy transfer from an active medium to a charged particle beam. While the previous work on the PASER has emphasized operations at infrared or visible wavelengths, operating in the microwave regime has significant advantages in terms of the less stringent quality requirements placed on the electron beam provided an appropriate microwave active medium can be found. This paper is focused on our investigation of the possibility of a PASER operating in the microwave frequency regime [2] using active paramagnetic materials. While a high level of gain for PCBM was demonstrated compared to other candidate materials, dielectric losses and quenching effects were found to negatively impact its performance for PASER applications. We present results on

  11. Energy expenditure prediction via a footwear-based physical activity monitor: Accuracy and comparison to other devices

    Science.gov (United States)

    Dannecker, Kathryn

    2011-12-01

    Accurately estimating free-living energy expenditure (EE) is important for monitoring or altering energy balance and quantifying levels of physical activity. The use of accelerometers to monitor physical activity and estimate physical activity EE is common in both research and consumer settings. Recent advances in physical activity monitors include the ability to identify specific activities (e.g. stand vs. walk) which has resulted in improved EE estimation accuracy. Recently, a multi-sensor footwear-based physical activity monitor that is capable of achieving 98% activity identification accuracy has been developed. However, no study has compared the EE estimation accuracy for this monitor and compared this accuracy to other similar devices. Purpose . To determine the accuracy of physical activity EE estimation of a footwear-based physical activity monitor that uses an embedded accelerometer and insole pressure sensors and to compare this accuracy against a variety of research and consumer physical activity monitors. Methods. Nineteen adults (10 male, 9 female), mass: 75.14 (17.1) kg, BMI: 25.07(4.6) kg/m2 (mean (SD)), completed a four hour stay in a room calorimeter. Participants wore a footwear-based physical activity monitor, as well as three physical activity monitoring devices used in research: hip-mounted Actical and Actigraph accelerometers and a multi-accelerometer IDEEA device with sensors secured to the limb and chest. In addition, participants wore two consumer devices: Philips DirectLife and Fitbit. Each individual performed a series of randomly assigned and ordered postures/activities including lying, sitting (quietly and using a computer), standing, walking, stepping, cycling, sweeping, as well as a period of self-selected activities. We developed branched (i.e. activity specific) linear regression models to estimate EE from the footwear-based device, and we used the manufacturer's software to estimate EE for all other devices. Results. The shoe

  12. A glasses-type wearable device for monitoring the patterns of food intake and facial activity

    Science.gov (United States)

    Chung, Jungman; Chung, Jungmin; Oh, Wonjun; Yoo, Yongkyu; Lee, Won Gu; Bang, Hyunwoo

    2017-01-01

    Here we present a new method for automatic and objective monitoring of ingestive behaviors in comparison with other facial activities through load cells embedded in a pair of glasses, named GlasSense. Typically, activated by subtle contraction and relaxation of a temporalis muscle, there is a cyclic movement of the temporomandibular joint during mastication. However, such muscular signals are, in general, too weak to sense without amplification or an electromyographic analysis. To detect these oscillatory facial signals without any use of obtrusive device, we incorporated a load cell into each hinge which was used as a lever mechanism on both sides of the glasses. Thus, the signal measured at the load cells can detect the force amplified mechanically by the hinge. We demonstrated a proof-of-concept validation of the amplification by differentiating the force signals between the hinge and the temple. A pattern recognition was applied to extract statistical features and classify featured behavioral patterns, such as natural head movement, chewing, talking, and wink. The overall results showed that the average F1 score of the classification was about 94.0% and the accuracy above 89%. We believe this approach will be helpful for designing a non-intrusive and un-obtrusive eyewear-based ingestive behavior monitoring system.

  13. Approach for the Development of a Framework for the Identification of Activities of Daily Living Using Sensors in Mobile Devices

    Science.gov (United States)

    Pombo, Nuno

    2018-01-01

    Sensors available on mobile devices allow the automatic identification of Activities of Daily Living (ADL). This paper describes an approach for the creation of a framework for the identification of ADL, taking into account several concepts, including data acquisition, data processing, data fusion, and pattern recognition. These concepts can be mapped onto different modules of the framework. The proposed framework should perform the identification of ADL without Internet connection, performing these tasks locally on the mobile device, taking in account the hardware and software limitations of these devices. The main purpose of this paper is to present a new approach for the creation of a framework for the recognition of ADL, analyzing the allowed sensors available in the mobile devices, and the existing methods available in the literature. PMID:29466316

  14. Approach for the Development of a Framework for the Identification of Activities of Daily Living Using Sensors in Mobile Devices.

    Science.gov (United States)

    Pires, Ivan Miguel; Garcia, Nuno M; Pombo, Nuno; Flórez-Revuelta, Francisco; Spinsante, Susanna

    2018-02-21

    Sensors available on mobile devices allow the automatic identification of Activities of Daily Living (ADL). This paper describes an approach for the creation of a framework for the identification of ADL, taking into account several concepts, including data acquisition, data processing, data fusion, and pattern recognition. These concepts can be mapped onto different modules of the framework. The proposed framework should perform the identification of ADL without Internet connection, performing these tasks locally on the mobile device, taking in account the hardware and software limitations of these devices. The main purpose of this paper is to present a new approach for the creation of a framework for the recognition of ADL, analyzing the allowed sensors available in the mobile devices, and the existing methods available in the literature.

  15. New monitoring technology to objectively assess adherence to prescribed footwear and assistive devices during ambulatory activity.

    Science.gov (United States)

    Bus, Sicco A; Waaijman, Roelof; Nollet, Frans

    2012-11-01

    To assess the validity and feasibility of a new temperature-based adherence monitor to measure footwear use. Observational study. University medical center and participants' homes. Convenience sample of healthy subjects (n=11) and neuropathic diabetic patients at high risk for foot ulceration (n=14). In healthy subjects, the validity of the in-shoe attached adherence monitor was investigated by comparing its registrations of donning and doffing of footwear during 7 days to an accurately kept log registration. In diabetic patients, the feasibility of using the adherence monitor for 7 days in conjunction with a time-synchronized ankle-worn step activity monitor to register prescribed footwear use during walking was assessed. Furthermore, a usability questionnaire was completed. For validity, the mean time difference and 95% confidence interval (CI) between moments of donning/doffing footwear recorded with the adherence monitor and in the log were calculated. For feasibility, technical performance, usability, and the percentage of steps that the footwear was worn (adherence) were assessed. The mean time difference between the adherence monitor and log recordings was 0.4 minutes (95% CI, 0.2-0.6min). One erroneous recording and 2 incomplete recordings were obtained in diabetic patients. Three patients reported discomfort with the step activity monitor, and 4 patients would not favor repeated testing. Patients used their footwear for between 9% and 99% of their walking steps. The adherence monitor shows good validity in measuring when footwear is used or not, and is, together with instrumented monitoring of walking activity, a feasible and objective method to assess treatment adherence. This method can have wide application in clinical practice and research regarding prescribed footwear and other body-worn assistive devices. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  16. UV and visible activation of Cr(III)-doped TiO2 catalyst prepared by a microwave-assisted sol-gel method during MCPA degradation.

    Science.gov (United States)

    Mendiola-Alvarez, S Y; Guzmán-Mar, J L; Turnes-Palomino, G; Maya-Alejandro, F; Hernández-Ramírez, A; Hinojosa-Reyes, L

    2017-05-01

    Photocatalytic degradation of 4-chloro-2-methylphenoxyacetic acid (MCPA) in aqueous solution using Cr(III)-doped TiO 2 under UV and visible light was investigated. The semiconductor material was synthesized by a microwave-assisted sol-gel method with Cr(III) doping contents of 0.02, 0.04, and 0.06 wt%. The catalyst was characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), nitrogen physisorption, UV-Vis diffuse reflectance spectroscopy (DRS), and atomic absorption spectroscopy (AAS). The photocatalytic activity for the photodegradation of MCPA was followed by reversed-phase high-performance liquid chromatography (HPLC) and total organic carbon (TOC) analysis. The intermediates formed during degradation were identified using gas chromatography-mass spectrometry (GC-MS). Chloride ion evolution was measured by ion chromatography. Characterization results showed that Cr(III)-doped TiO 2 materials possessed a small crystalline size, high surface area, and mesoporous structure. UV-Vis DRS showed enhanced absorption in the visible region as a function of the Cr(III) concentration. The Cr(III)-doped TiO 2 catalyst with 0.04 wt% of Cr(III) was more active than bare TiO 2 for the degradation of MCPA under both UV and visible light. The intermediates identified during MCPA degradation were 4-chloro-2-methylphenol (CMP), 2-(4-hydroxy-2-methylphenoxy) acetic acid (HMPA), and 2-hydroxybuta-1,3-diene-1,4-diyl-bis (oxy)dimethanol (HBDM); the formation of these intermediates depended on the radiation source.

  17. Critical current fluctuation in a microwave-driven Josephson junction

    International Nuclear Information System (INIS)

    Dong Ning; Sun Guozhu; Wang Yiwen; Cao Junyu; Yu Yang; Chen Jian; Kang Lin; Xu Weiwei; Han Siyuan; Wu Peiheng

    2007-01-01

    Josephson junction devices are good candidates for quantum computation. A large energy splitting was observed in the spectroscopy of a superconducting Josephson junction. The presence of the critical current fluctuation near the energy splitting indicated coupling between the junction and a two-level system. Furthermore, we find that this fluctuation is microwave dependent. It only appears at certain microwave frequency. This relation suggested that the decoherence of qubits is influenced by the necessary computing operations

  18. Bistable laser device with multiple coupled active vertical-cavity resonators

    Science.gov (United States)

    Fischer, Arthur J.; Choquette, Kent D.; Chow, Weng W.

    2003-08-19

    A new class of bistable coupled-resonator vertical-cavity semiconductor laser devices has been developed. These bistable laser devices can be switched, either electrically or optically, between lasing and non-lasing states. A switching signal with a power of a fraction of a milliwatt can change the laser output of such a device by a factor of a hundred, thereby enabling a range of optical switching and data encoding applications.

  19. Recyclable Keggin Heteropolyacids as an Environmentally Benign Catalyst for the Synthesis of New 2-Benzoylamino-N-phenyl-benzamide Derivatives under Microwave Irradiations at Solvent-Free Conditions and the Evaluation of Biological Activity.

    Science.gov (United States)

    Ighilahriz-Boubchir, Karima; Boutemeur-Kheddis, Baya; Rabia, Cherifa; Makhloufi-Chebli, Malika; Hamdi, Maamar; Silva, Artur M S

    2017-12-21

    2-Benzoylamino- N -phenyl-benzamide derivatives ( 5a - h ) were prepared from 2-phenyl-3,1-(4 H )-benzoxazin-4-one 3 and substituted anilines 4a - h in the presence of a Keggin-type heteropolyacids series (H₃PW 12 O 40 ·13H₂O; H₄SiW 12 O 40 ·13H₂O; H₄SiMo 12 O 40 ·13H₂O; and H₃PMo 12 O 40 ·13H₂O) as catalysts without solvent and under microwave irradiation. We found that the use of H₃PW 12 O 40 ·13H₂O acid coupled to microwave irradiation allowed obtaining a high-yielding reaction with a short time. The compound structures were established by ¹H-NMR and 13 C-NMR. The antibacterial and antifungal activities of the synthesized compounds exhibited an inhibition of the growth of bacteria and fungi.

  20. Microwave Assisted Convenient One-Pot Synthesis of Coumarin Derivatives via Pechmann Condensation Catalyzed by FeF3 under Solvent-Free Conditions and Antimicrobial Activities of the Products

    Directory of Open Access Journals (Sweden)

    Vahid Vahabi

    2014-08-01

    Full Text Available A rapid and efficient solvent-free one-pot synthesis of coumarin derivatives by Pechmann condensation reactions of phenols with ethyl acetoacetate using FeF3 as a catalyst under microwave irradiation is described. This one-pot synthesis on a solid inorganic support provides the products in good yields. The newly synthesized compounds were systematically characterized by IR, 1H-NMR, 13C-NMR, MS and elemental CHN analyses. The proposed solvent-free microwave irradiation method using the environmentally friendly catalyst FeF3 offers the unique advantages of high yields, shorter reaction times, easy and quick isolation of the products, excellent chemoselectivity, and a one-pot, green synthesis. The products were screened for antimicrobial activity, and the results showed that the compounds reacted against all the tested bacteria.