Underwater Ultrasonic Multipath Diffraction Model for Short Range Communication and Sensing Applications

Short-range ultra-wideband (UWB) radar sensors belong to very promising sensing techniques that have received vast attention recently. The M-sequence UWB sensing techniques for radio detection and ranging feature several advantages over the other short-range radars, inter alia superior integration capabilities. The prerequisite to investigate their capabilities in real scenarios is the existence of physically available hardware, i.e., particular functional system blocks. In this paper, we present three novel blocks of M-sequence UWB radars exploiting application-specific integrated circuit (ASIC) technology. These are the integrated 15th-order M-sequence radar transceiver on one chip, experimental active Electronic Communication Committee (ECC) bandpass filter, and miniature transmitting UWB antenna with an integrated amplifier. All these are custom designs intended for the enhancement of capabilities of an M-sequence-based system family for new UWB short-range sensing applications. The design approaches and verification of the manufactured prototypes by measurements of the realized circuits are presented in this paper. The fine balance on technology capabilities (Fc of roughly 120 GHz) and thoughtful design process of the proposed blocks is the first step toward remarkably minimized devices, e.g., as System on Chip designs, which apparently allow broadening the range of new applications.

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Diffraction model of short-range longitudinal wakefields in circular and rectangular structures

Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment ◽

10.1016/s0168-9002(01)00950-0 ◽

2002 ◽

Vol 480 (2-3) ◽

pp. 289-303 ◽

Cited By ~ 2

Author(s):

A.V. Smirnov

Keyword(s):

Short Range ◽

Diffraction Model

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Long- and Short-Range Ordered Gold Nanoholes as Large-Area Optical Transducers in Sensing Applications

Chemosensors ◽

10.3390/chemosensors7010013 ◽

2019 ◽

Vol 7 (1) ◽

pp. 13 ◽

Cited By ~ 1

Author(s):

Maura Cesaria ◽

Adriano Colombelli ◽

Daniela Lospinoso ◽

Antonietta Taurino ◽

Enrico Melissano ◽

...

Keyword(s):

Self Assembly ◽

Short Range ◽

Low Cost ◽

Hexagonal Lattice ◽

Solid Substrate ◽

Attractive Alternative ◽

Large Area ◽

Glass Substrates ◽

Self Assembling ◽

Sensing Applications

Unconventional lithography (such as nanosphere lithography (NSL) and colloidal lithography (CL)) is an attractive alternative to sequential and very expensive conventional lithography for the low-cost fabrication of large-area nano-optical devices. Among these, nanohole (NH) arrays are widely studied in nanoplasmonics as transducers for sensing applications. In this work, both NSL and CL are implemented to fabricate two-dimensional distributions of gold NHs. In the case of NSL, highly ordered arrays of gold NHs distributed in a hexagonal lattice onto glass substrates were fabricated by a simple and reproducible approach based on the self-assembling of close-packed 500 nm diameter polystyrene particles at an air/water interface. After the transfer onto a solid substrate, the colloidal masks were processed to reduce the colloidal size in a controllable way. In parallel, CL was implemented with short-range ordered gold NH arrays onto glass substrates that were fabricated by electrostatically-driven self-assembly of negatively charged colloids onto a polydiallyldimethylammonium (PDDA) monolayer. These distributions were optimized as a function of the colloidal adsorption time. For both approaches, controllable and reproducible procedures are presented and discussed. The optical responses of the NH structures are related to the short-range ordering level, and their good performances as refractive index transducers are demonstrated.

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Domain coarsening by grain boundary migration in ordered Ni4Mo

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144279 ◽

1986 ◽

Vol 44 ◽

pp. 560-561

Author(s):

K. Vasudevan ◽

H. P. Kao ◽

C. R. Brooks ◽

E. E. Stansbury

Keyword(s):

Grain Boundary ◽

Grain Boundaries ◽

Short Range ◽

Boundary Migration ◽

Grain Boundary Migration ◽

Rapid Cooling ◽

Temperature Range ◽

Fee Structure ◽

Domain Coarsening ◽

Boundary Reaction

The Ni4Mo alloy has a short-range ordered fee structure (α) above 868°C, but transforms below this temperature to an ordered bet structure (β) by rearrangement of atoms on the fee lattice. The disordered α, retained by rapid cooling, can be ordered by appropriate aging below 868°C. Initially, very fine β domains in six different but crystallographically related variants form and grow in size on further aging. However, in the temperature range 600-775°C, a coarsening reaction begins at the former α grain boundaries and the alloy also coarsens by this mechanism. The purpose of this paper is to report on TEM observations showing the characteristics of this grain boundary reaction.

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Ordering in Ni4Mo by TEM and APFIM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012597x ◽

1987 ◽

Vol 45 ◽

pp. 214-215

Author(s):

E.A. Kenik ◽

T.A. Zagula ◽

M.K. Miller ◽

J. Bentley

Keyword(s):

Electron Irradiation ◽

Low Temperatures ◽

Short Range ◽

Atom Probe ◽

Range Order ◽

Considerable Time ◽

Probe Field ◽

Disordered Phase ◽

Transmission Electron ◽

Diffraction Patterns

The state of long-range order (LRO) and short-range order (SRO) in Ni4Mo has been a topic of interest for a considerable time (see Brooks et al.). The SRO is often referred to as 1½0 order from the apparent position of the diffuse maxima in diffraction patterns, which differs from the positions of the LRO (D1a) structure. Various studies have shown that a fully disordered state cannot be retained by quenching, as the atomic arrangements responsible for the 1½0 maxima are present at temperatures above the critical ordering temperature for LRO. Over 20 studies have attempted to identify the atomic arrangements associated with this state of order. A variety of models have been proposed, but no consensus has been reached. It has also been shown that 1 MeV electron irradiation at low temperatures (∼100 K) can produce the disordered phase in Ni4Mo. Transmission electron microscopy (TEM), atom probe field ion microscopy (APFIM), and electron irradiation disordering have been applied in the current study to further the understanding of the ordering processes in Ni4Mo.

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Early Education in Short-Range Historical Perspective

Contemporary Psychology ◽

10.1037/009780 ◽

1969 ◽

Vol 14 (8) ◽

pp. 437-438

Author(s):

CELIA STENDLER LAVATELLI

Keyword(s):

Short Range ◽

Historical Perspective ◽

Early Education

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Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020190250 ◽

2020 ◽

Vol 90 (3) ◽

pp. 30502

Author(s):

Alessandro Fantoni ◽

João Costa ◽

Paulo Lourenço ◽

Manuela Vieira

Keyword(s):

Amorphous Silicon ◽

High Throughput Screening ◽

Simulation Analysis ◽

Low Cost ◽

Deposition Process ◽

Large Area ◽

Sidewall Roughness ◽

Sensing Applications ◽

Fabrication Defects ◽

The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

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