1,312 results match your criteria khz good

Electro-Optic Modulation Using Metal-Free Perovskites.

ACS Appl Mater Interfaces 2021 Apr 15. Epub 2021 Apr 15.

Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.

Electro-optic (EO) modulation is of interest to impart information onto an optical carrier. Inorganic crystals-most notably LiNbO and BaTiO-exhibit EO modulation and good stability, but are difficult to integrate with silicon photonic technology. Solution-processed organic EO materials are readily integrated but suffer from thermal degradation at the temperatures required in operating conditions for accelerated reliability studies. Read More

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Sonication treatment of pomegranate juice containing and : Thermodynamic and predictive modeling after treatment and during shelf life.

Food Sci Technol Int 2021 Apr 14:10820132211009442. Epub 2021 Apr 14.

Department of Mechanical Engineering, Fasa University, Fasa, Iran.

The effect of ultrasound treatment (100 W, 30 kHz; 50 and 100% amplitudes) on inactivation of and in pomegranate juice and shelf life of the juice during storage at different temperatures (5, 15 and 30 °C) for 30 days was modeled using predictive and thermodynamics models. The Baranyi and square root type models were implemented to determine the growth rate of microorganisms. It was predicted that the minimum growth temperature () of increased by increasing sonication amplitude, however, the of was not function of sonication amplitude. Read More

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Ultrafast Nonlinear Optical and Structure-Property Relationship Studies of Pyridine-Based Anthracene Chalcones Using -Scan, Degenerate Four-Wave Mixing, and Computational Approaches.

J Phys Chem B 2021 Apr 8. Epub 2021 Apr 8.

X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, George Town, Penang 11800, Malaysia.

The structural, thermal, linear, and femtosecond third-order nonlinear optical (NLO) properties of two pyridine-based anthracene chalcones, (2)-1-(anthracen-9-yl)-3-(pyridin-2-yl)prop-2-en-1-one () and (2)-1-(anthracen-9-yl)-3-(pyridin-3-yl)prop-2-en-1-one (), were investigated. These two chalcones were synthesized following the Claisen-Schmidt condensation method. Optically transparent single crystals were achieved using a slow evaporation solution growth technique. Read More

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Ultrathin Conformal Magnetic Invisible Cloak for Irregular Objects.

ACS Appl Mater Interfaces 2021 Apr 6;13(14):17104-17109. Epub 2021 Apr 6.

State Key Lab of Modern Optical Instrumentation, Centre for Optical and Electromagnetic Research, College of Optical Science and Engineering; International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310027, China.

Magnetic invisible cloaking has been previously demonstrated but only limited to objects with rotational geometries either in spherical or cylindrical shapes, for which the classic analytical bilayer scheme could be strictly applied to design the hiding coat. In this work, we show that a quasi-static cloaking effect could be achieved for irregular objects, e.g. Read More

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Narrow-linewidth high-efficiency single-frequency ytterbium-doped fiber laser with highly linear polarization at 1064  nm.

Appl Opt 2021 Apr;60(10):2833-2838

We present a linearly polarized single-longitudinal-mode (SLM) ytterbium-doped fiber laser with a polarization extinction ratio (PER) of over 35 dB and a narrow linewidth of less than 4.5 kHz. The very high PER is obtained by utilizing the polarization evolution effect at the optical fiber and the high-performance polarizing beam splitter. Read More

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Strain sensing based on resonant states in 2D dielectric photonic quasicrystals.

Opt Express 2021 Mar;29(5):6980-6990

This paper reports the numerical and experimental study of the strain sensing effect of bidimensional quasiperiodic structures made with dielectric cylinders. Structures of around 100 cylinders arranged following a Penrose quasiperiodic disposition were simulated, built and measured, in different states of deformation. The selected quasiperiodic structure contains a symmetric decagonal ring resonator that shows two states in its photonic band gap. Read More

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Wideband fiber-optic Fabry-Perot acoustic sensing scheme using high-speed absolute cavity length demodulation.

Opt Express 2021 Mar;29(5):6768-6779

In this paper, we realize a wideband fiber-optic Fabry-Perot (F-P) acoustic sensing (FPAS) scheme by utilizing a high-speed absolute cavity length demodulation with a 70-kHz maximum line rate spectrometer. The wideband FPAS is made of a pre-stress stainless-steel diaphragm based on F-P interferometric structure. The real-time absolute F-P cavity lengths are calculated by a phase demodulation method, which is realized by processing the interference image at a 70-kHz frame rate. Read More

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Plasma Polymerized SiCOH Films from Octamethylcyclotetrasiloxane by Dual Radio Frequency Inductively Coupled Plasma Chemical Vapor Deposition System.

J Nanosci Nanotechnol 2021 Aug;21(8):4477-4483

Department of Physics, Hankuk University of Foreign Studies, Yongin, 17035, Republic of Korea.

We have fabricated porous plasma polymerized SiCOH (ppSiCOH) films with low-dielectric constants (low-, less than 2.9), by applying dual radio frequency plasma in inductively coupled plasma chemical vapor deposition (ICP-CVD) system. We varied the power of the low radio frequency (LF) of 370 kHz from 0 to 65 W, while fixing the power of the radio frequency (RF) of 13. Read More

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Experimental investigation of femtosecond laser through-hole drilling of stainless steel with and without transverse magnetic assistance.

Appl Opt 2021 Feb;60(5):1399-1410

An experimental investigation of femtosecond laser through-hole drilling of stainless-steel 304 with and without transverse magnetic assistance was conducted. The characteristics of the through-hole geometry and sidewall as well as the chemical composition of the through-hole sidewall surface were analyzed. In addition, a theoretical analysis of magnetic-field-assisted femtosecond laser through-hole drilling is proposed. Read More

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February 2021

Efficient 0.75-mJ 100-kHz ultraviolet pulsed laser based on a rod-type photonic crystal fiber.

Appl Opt 2021 Feb;60(5):1191-1195

We have developed a high-power ultraviolet (UV) nanosecond-pulsed laser based on a rod-type photonic crystal fiber. The UV pulse energy and the pulse repetition rate are 0.75 mJ and 100 kHz, respectively, yielding 75-W UV average power. Read More

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February 2021

Understanding the effects of mineral water matrix on degradation of several pharmaceuticals by ultrasound: Influence of chemical structure and concentration of the pollutants.

Ultrason Sonochem 2021 Feb 20;73:105500. Epub 2021 Feb 20.

Grupo de Investigación en Remediación Ambiental y Biocatálisis, Instituto de Química, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia. Electronic address:

Degradation of seven relevant pharmaceuticals with different chemical structures and properties: acetaminophen (ACE), cloxacillin (CXL), diclofenac (DCF), naproxen (NPX), piroxicam (PXC), sulfacetamide (SAM) and cefadroxil (CDX), in distilled water and mineral water by ultrasound was studied herein. Firstly, proper conditions of frequency and acoustic power were determined based on the degradation ability of the system and the accumulation of sonogenerated hydrogen peroxide (24.4 W and 375 kHz were found as the suitable conditions for the sonochemical treatment of the pharmaceuticals). Read More

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February 2021

Research and Fabrication of Broadband Ring Flextensional Underwater Transducer.

Sensors (Basel) 2021 Feb 23;21(4). Epub 2021 Feb 23.

Acoustic Science and Technology Laboratory, Harbin Engineering University, Harbin 150001, China.

At present, high-speed underwater acoustic communication requires underwater transducers with the characteristics of low frequency and broadband. The low-frequency transducers also are expected to be low-frequency directional for realization of point-to-point communication. In order to achieve the above targets, this paper proposes a new type of flextensional transducer which is constructed of double mosaic piezoelectric ceramic rings and spherical cap metal shells. Read More

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February 2021

Analysis of phase response of fiber Fabry-Pérot cavity microphones.

J Acoust Soc Am 2021 Feb;149(2):1012

Department of Precision Instrument, Tsinghua University, Beijing 100084, China.

In this paper, the phase response of fiber Fabry-Pérot cavity-based fiber optic microphones (FFPC-FOMs) is discussed through an analysis of the results of simulation and experiments. The phase difference of FFPC-FOMs mainly originates from two aspects: different phase lags of the mechanical-acoustic systems and different quadrature working points (Q*) on interference curves. The former is analyzed by an impedance-type analogous circuit, and the simulation results reveal that the change in cavity length and resonance frequency in a large range have an insignificant influence on the phase difference. Read More

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February 2021

Detecting Intralabyrinthine Pressure Increase by Postural Manipulation with Wideband Tympanometry and Distortion Product Otoacoustic Emissions.

Turk Arch Otorhinolaryngol 2020 Dec 1;58(4):203-207. Epub 2020 Dec 1.

Department of Otolaryngology, Pamukkale University School of Medicine, Denizli, Turkey.

Objective: Intracranial pressure increase is known to affect inner ear pressure through the cochlear and vestibular aqueducts. This finding forms a good model for inner ear pressure studies. Standard techniques used to detect this pressure increase are neither reliable nor easily repeatable or cheap. Read More

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December 2020

Carbon Nanotube Modified Microelectrode Array for Neural Interface.

Front Bioeng Biotechnol 2020 13;8:582713. Epub 2021 Jan 13.

Department of Medical Physics and Biomedical Engineering, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Carbon nanotubes (CNTs) coatings have been shown over the past few years as a promising material for neural interface applications. In particular, in the field of nerve implants, CNTs have fundamental advantages due to their unique mechanical and electrical properties. In this study, carbon nanotubes multi-electrode arrays (CNT-modified-Au MEAs) were fabricated based on gold multi-electrode arrays (Au-MEAs). Read More

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January 2021

A novel hybrid construction of MnMoO nanorods anchored graphene nanosheets; an efficient electrocatalyst for the picomolar detection of ecological pollutant ornidazole in water and urine samples.

Chemosphere 2021 Jan 18;273:129665. Epub 2021 Jan 18.

Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.

Nitroimidazole compounds are widely used antibiotics to encounter anaerobic bacterial and parasitic infections. The wide usage of antibiotic drugs became an ecological contaminant which in turn into potential monitoring. In this regards, we have designed and developed a new electrochemical sensing probe to monitor an antiprotozoal drug, ornidazole (ODZ), with the aid of a glassy carbon electrode (GCE) integrated with manganese molybdate nanorods (MnMoO) decorated graphene nanosheets (GNS) hybrid materials that prepared by feasible probe sonochemical method (parameters: 2-4 W, 5 mV amp, 20 kHz). Read More

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January 2021

An audit of UK audiological practice in specialist paediatric oncology centres regarding hearing assessment of children at risk of ototoxicity due to chemotherapy.

J Laryngol Otol 2021 Jan 25;135(1):14-20. Epub 2021 Jan 25.

Nottingham Audiology Services, Nottingham University Hospitals Trust, Nottingham, UK.

Objective: Platinum-based chemotherapy drugs are associated with substantial ototoxicity. The hearing of children treated with these drugs should be closely monitored.

Method: A questionnaire was sent out to the 19 audiology departments associated with national paediatric cancer specialist centres in the UK looking at current practice in ototoxicity monitoring. Read More

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January 2021

Significantly Improved Dielectric Performance of Poly(1-butene)-Based Composite Films via Filling Polydopamine Modified Ba(ZrTi)O-Coated Multiwalled Carbon Nanotubes Nanoparticles.

Polymers (Basel) 2021 Jan 17;13(2). Epub 2021 Jan 17.

School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China.

The low dielectric constant of the nonpolar polymer poly(1-butene) (PB-1) limits its application as a diaphragm element in energy storage capacitors. In this work, Ba(ZrTi)O-coated multiwalled carbon nanotubes (BZT@MWCNTs) were first prepared by using the sol-gel hydrothermal method and then modified with polydopamine (PDA) via noncovalent polymerization. Finally, PB-1 matrix composite films filled with PDA-modified BZT@MWCNTs nanoparticles were fabricated through a solution-casting method. Read More

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January 2021

High-Frequency Spinal Cord Stimulation at 10 kHz for the Treatment of Nonsurgical Refractory Back Pain: Design of a Pragmatic, Multicenter, Randomized Controlled Trial.

Pain Pract 2021 Feb 26;21(2):171-183. Epub 2020 Sep 26.

Nevro Corp, Redwood City, California, U.S.A.

Background: Spinal cord stimulation (SCS) has been shown to provide pain relief for chronic back and leg pain due to failed back surgery syndrome. But many patients with chronic back pain have not had major back surgery or are not good candidates for surgery, and conventional medical management (CMM) provides limited relief. We have termed this condition nonsurgical refractory back pain (NSRBP). Read More

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February 2021

Randomized Prospective Study in Patients With Complex Regional Pain Syndrome of the Upper Limb With High-Frequency Spinal Cord Stimulation (10-kHz) and Low-Frequency Spinal Cord Stimulation.

Neuromodulation 2021 Apr 18;24(3):448-458. Epub 2021 Jan 18.

Unit of Preventive Medicine and Public Health, Department of Preventive Medicine and Public Health, Food Sciences, Toxicology and Forensic Medicine, Universitat de València, Valencia, Spain.

Objective: The objective of this prospective randomized study of cases and controls was to evaluate the efficacy of treatment with low-frequency spinal cord stimulation (LF-SCS) and 10 kHz spinal cord stimulation (10-kHz SCS) in patients diagnosed with complex regional pain syndrome type I (CRPS) with upper limb involvement.

Materials And Methods: Fifty patients were randomized to receive conventional treatment or SCS with a commercially available low-frequency or 10-kHz system. Patients were assessed at 1, 3, 6, and 12 months. Read More

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Stapes surgery in osteogenesis imperfecta: retrospective analysis of 18 operated ears.

Eur Arch Otorhinolaryngol 2021 Jan 12. Epub 2021 Jan 12.

Department of Otorhinolaryngology-Head and Neck Surgery and Audiophonology, University Hospital, Rouen, France.

Purpose: To evaluate short and long term results of stapes surgery in patients with osteogenesis imperfecta (OI), METHODS: Retrospective case series of 18 primary stapes surgeries performed on 11 hearing-impaired OI patients with evidence of stapes fixation, in a Tertiary referral center. We analysed pre-operative and post-operative hearing results at 1 month and at least 1 year RESULTS: The main operative findings were stapes fixation, thickened footplate and fragile or fractured stapes crura. No revision surgery was necessary. Read More

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January 2021

Design and Fabrication of a High-Speed Atomic Force Microscope Scan-Head.

Sensors (Basel) 2021 Jan 7;21(2). Epub 2021 Jan 7.

Department of Mechanical Engineering, Kyungpook National University, Daegu 41566, Korea.

A high-speed atomic force microscope (HS-AFM) requires a specialized set of hardware and software and therefore improving video-rate HS-AFMs for general applications is an ongoing process. To improve the imaging rate of an AFM, all components have to be carefully redesigned since the slowest component determines the overall bandwidth of the instrument. In this work, we present a design of a compact HS-AFM scan-head featuring minimal loading on the Z-scanner. Read More

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January 2021

Enhanced Dielectric and Hydrophobic Properties of Poly(vinylidene fluoride-trifluoroethylene)/TiO Nanowire Arrays Composite Film Surface Modified by Electrospinning.

Polymers (Basel) 2020 Dec 29;13(1). Epub 2020 Dec 29.

Research Institute of Zhejiang University-Taizhou, Taizhou 318000, China.

In this research, we designed a feasible method to prepare composite films with high permittivity and significantly enhanced hydrophobic performance, which showed huge potential in the electrowetting field. TiO nanowire arrays were prepared by a one-step hydrothermal process, and poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) was spin-coated on the nanowire arrays to form composite, the surface of which was modified by electrospinning. Due to the great orientation of TiO nanowires, dipoles and space charges are in ordered arrangement along the electric field, and this strongly reinforced the Maxwell-Wagner-Sillars (MWS) polarization, thus the permittivity of the composite (TiO nanowire length/film thickness is 0. Read More

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December 2020

Comparing spontaneous and stimulus frequency otoacoustic emissions in mice with tectorial membrane defects.

Hear Res 2021 Feb 5;400:108143. Epub 2020 Dec 5.

The Knowles Hearing Center, Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, 2-240 Frances Searle Building, 2240 Campus Drive, Evanston IL 60208, USA. Electronic address:

The global standing-wave model for generation of spontaneous otoacoustic emissions (SOAEs) suggests that they are amplitude-stabilized standing waves and that the spacing between SOAEs corresponds to the interval over which the phase changes by one cycle as determined from the phase-gradient delays of stimulus frequency otoacoustic emissions (SFOAEs). Because data characterizing the relationship between spontaneous and evoked emissions in nonhuman mammals are limited, we examined SOAEs and SFOAEs in tectorial membrane (TM) mutants and their controls. Computations indicate that the spacing between adjacent SOAEs is predicted by the SFOAE phase-gradient delays for TM mutants lacking Ceacam16, where SOAE frequencies are greater than ~20 kHz and the mutants retain near-normal hearing when young. Read More

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February 2021

Phase-only modulation of light.

Opt Lett 2020 Dec;45(24):6703-6706

We disclose the method to obtain polarization insensitive phase-only modulation that preserves both the state and the degree of polarization of light modulated using a medium with controlled birefringence. We find that, in the double-pass configuration involving reflection from the Faraday rotator mirror, such a medium acts as the phase-only modulator. The experimental data measured in the Michelson-interferometer-based setup for deformed-helix ferroelectric liquid crystal cells are found to be in good agreement with the theoretical results. Read More

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December 2020

Validation of Hearing Loss Prediction Tool for Cisplatin Chemotherapy and Radiation in Head and Neck Cancer Treatment.

JAMA Otolaryngol Head Neck Surg 2021 02;147(2):182-189

Department of Otolaryngology-Head & Neck Surgery, Washington University School of Medicine, St Louis, Missouri.

Importance: Hearing loss affects up to 88% of patients undergoing head and neck cancer treatment; however, there are few validated models to predict this outcome. A predictive posttreatment model for hearing loss will allow clinicians and patients to make well-informed decisions about treatment with cisplatin-based chemotherapies and radiotherapy.

Objective: To validate a previously created predictive model for objective hearing outcomes and to assess barriers to using the prediction nomogram in general practice for patients newly diagnosed with head and neck cancer. Read More

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February 2021

Validity of hearTest Smartphone-Based Audiometry for Hearing Screening in Workers Exposed to Noise.

J Am Acad Audiol 2020 Dec 9. Epub 2020 Dec 9.

Postgraduate Programme in Environmental Health and Work, Faculty of Medicine, Federal University of Bahia, Salvador, Brazil.

Purpose:  This article investigates the validity of a smartphone-based audiometry for hearing screening to identify hearing loss in workers exposed to noise.

Research Design:  This is a validation study comparing hearing screening with the hearTest to conventional audiometry. The study population included all workers who attended the Brazilian Social Service of Industry to undergo periodic examinations. Read More

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December 2020

Continuous wave electron paramagnetic resonance L-band spectrometer with direct digitalization using time-locked subsampling.

J Magn Reson 2021 Jan 7;322:106870. Epub 2020 Nov 7.

Jagiellonian University, Faculty of Biochemistry, Biophysics and Biotechnology, Department of Molecular Biophysics, 7 Gronostajowa St., 30-387 Krakow, Poland. Electronic address:

This article describes a novel digital L-band EPR spectrometer. The spectrometer uses direct digital detection with time-locked subsampling (TLSS). The device consists of a microwave bridge equipped with a microwave source based on direct digital synthesis (DDS) and a digital receiver. Read More

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January 2021

Zero-Dimensional MXene-Based Optical Devices for Ultrafast and Ultranarrow Photonics Applications.

Adv Sci (Weinh) 2020 Nov 27;7(22):2002209. Epub 2020 Sep 27.

Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics Collaborative Innovation Center for Optoelectronic Science and Technology Shenzhen University Shenzhen 518060 China.

In recent years, MXene has become a hotspot because of its good conductivity, strong broadband absorption, and tunable band gap. In this contribution, 0D MXene TiCT quantum dots are synthesized by a liquid exfoliation method and a wideband nonlinear optical response from 800 to 1550 nm is studied, which have a larger nonlinear absorption coefficient of -(11.24 ± 0. Read More

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November 2020

The eight cervical nerve and its role in tinnitus.

Int Tinnitus J 2020 Nov 18;24(1):15-20. Epub 2020 Nov 18.

Introduction: The eight cervical nerve might be a source of input to the auditory system.

Objectives: The object was to assess the efficacy of infiltration of the eight cervical nerve root for treating tinnitus patients and to find indicators for a successful result.

Design: Retrospective cohort study. Read More

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November 2020