11,032 results match your criteria hardness method


A novel CAD/CAM resin composite block with high mechanical properties.

Dent Mater 2021 Apr 10. Epub 2021 Apr 10.

Glidewell Dental, Irvine, CA, USA.

Objective: To determine the mechanical properties of a newly-developed CAD/CAM resin composite block and compare with other resin composite blocks and a polymer-infiltrated ceramic block.

Methods: Experimental composite block was formulated by our proprietary resin and filler technologies and cured via Hot Isostatic Pressing (HIP). Bar-shaped specimens (1 × 4×12 - 13 mm, n = 10) for flexural strength, flexural modulus and modulus of resilience were sectioned from block materials and measured in accordance to modified ISO-6872. Read More

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Development of a sensitive direct injection LC-MS/MS method for the detection of glyphosate and aminomethylphosphonic acid (AMPA) in hard waters.

Anal Bioanal Chem 2021 Apr 12. Epub 2021 Apr 12.

Department of Civil and Environmental Engineering, Duke University, 121 Hudson Hall, Box 90287, Durham, NC, 27708-0287, USA.

Glyphosate is currently the most widely used herbicide in the world; however, the zwitterionic and highly polar properties of glyphosate make current pesticide analysis methods unsuitable for its trace analysis in natural waters. Additionally, current glyphosate analysis methods do not account for waters of varying hardness, which is vital as glyphosate can complex with cationic species such as Ca and Mg in the environment. We detail here a robust LC-MS/MS method for the quantitation of glyphosate and its primary transformation product aminomethylphosphonic acid (AMPA) in environmental waters of varying water hardness. Read More

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Establishing a novel method for assessing elasticity of internal anal sphincter using ultrasonic real-time tissue elastography.

ANZ J Surg 2021 Apr 12. Epub 2021 Apr 12.

Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.

Background: Evaluating anorectal function using real-time tissue elastography (RTE) has not been reported. A previous study reported that in the internal anal sphincter (IAS) of surgical specimens of patients with rectal cancer who underwent abdominoperineal resection, there was an increased fibrosis trend in those who underwent pre-operative chemoradiotherapy (CRT) compared with non-CRT. We speculated that CRT might have induced sclerosis of the IAS because of fibrosis. Read More

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Comparative analysis the performance of electrochemical water softening between high frequency electric fields and direct current electric fields based on orthogonal experimental methods.

Water Sci Technol 2021 Apr;83(7):1677-1690

School of Mechanical & Electrical Engineering, Wuhan Institute of Technology, Wuhan 430000, China E-mail:

Electrochemical water softening has been widely used in industrial circulating cooling water systems; however, their low deposition efficiency is the main drawback that limits usage in medium to large enterprises. In this work, the effect of different parameters on the hardness removal efficiency and energy consumption of the electrochemical water softening system is experimentally studied, and the performance of water softening applied by high frequency electric fields and direct current electric fields are comparative analyzed. The impact factors of the electrochemical water softening system are as follows: initial feed concentration of solute, magnitude of voltage, inter-electrode distance, area of cathode and frequency of power supply. Read More

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Synthesis, microstructural characterization and nanoindentation of Zr, Zr-nitride and Zr-carbonitride coatings deposited using magnetron sputtering.

Authors:
Anwar Ul-Hamid

J Adv Res 2021 Mar 25;29:107-119. Epub 2020 Nov 25.

Center for Engineering Research, Research Institute, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia.

Introduction: Hard coatings are primarily based on carbides, nitrides and carbonitrides of transition metal elements such as W, Ti, Zr, etc. Zr-based hard coatings show good resistance to wear, erosion, and corrosion as well as exhibit high hardness, high temperature stability, and biocompatibility, making them suitable candidates for tribological, biomedical, and electrical applications.

Objectives: The present study aims to synthesize uniform and adherent hard Zr-based coatings that demonstrate sound mechanical integrity. Read More

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A preliminary study on enhancing safety of contact features in the terrain park.

J Sci Med Sport 2021 Mar 31. Epub 2021 Mar 31.

C. Roberts Consulting Engineers, Inc., USA. Electronic address:

Objectives: Terrain park riders use contact features such as fun boxes and rails. Typical fun box and rail features have a design characteristic that can be changed to improve safety. Fun box edge coping and edges of rails are typically constructed of soft steel. Read More

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PILP remineralization of artificial and natural dentin carious lesions evaluated by nanoindentation and microcomputed tomography.

J Dent 2021 Apr 6:103659. Epub 2021 Apr 6.

Department of Preventative and Restorative Dental Sciences, UCSF School of Dentistry, San Francisco, CA, USA. Electronic address:

Objectives: The study evaluates the efficacy to remineralize artificial and natural dentin lesions through restorative dental procedures that include the Polymer-Induced Liquid Precursor (PILP) method comprising polyaspartic acid (pAsp).

Methods: Novel ionomeric cement compositions based on bioglass 45S5 and pAsp mixtures, as well as conditioning solutions (conditioner) containing 5 mg/ml pAsp, were developed and tested on demineralized dentin blocks (3-4 mm thick) on shallow and deep lesions with the thickness of 150 µm ± 50 and 700 µm ± 50, respectively. In the first treatment group, 20 µl of conditioner was applied to demineralized shallow (n = 3) and deep (n = 3) lesion specimens for 20 s before restoration with glass ionomer cement (RMGIC). Read More

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and evaluation of taste-masked orodispersible tablets of fluoxetine hydrochloride for the treatment of depression.

Drug Dev Ind Pharm 2021 Apr 7:1-9. Epub 2021 Apr 7.

Faculty of Pharmacy, Pharmaceutics and Industrial Pharmacy Department, Al-Azhar University, Nasr City, Egypt.

Aim: Fluoxetine (FLX) has become the first-line drug in the pharmacotherapy of patients with depression. However, it has a strong unpleasant bitter taste, leading to the failure to complete the therapy. In this study, FLX is formulated into orodispersible tablets (ODTs) characterized by a fast release with an acceptable taste. Read More

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Remineralization Potential of Nanohydroxyapatite Toothpaste Compared with Tricalcium Phosphate and Fluoride Toothpaste on Artificial Carious Lesions.

Int J Dent 2021 20;2021:5588832. Epub 2021 Mar 20.

Division of Pediatric Dentistry and Biomaterials Research, Faculty of Dentistry, Khon Kaen University, Khon Kaen 40002, Thailand.

Introduction: Nanohydroxyapatite (nano-HA) has been utilized as an alternative agent for dental enamel remineralization. This study compared remineralization potential of nano-HA toothpaste (NHT), functionalized tricalcium phosphate toothpaste (TCPT), and fluoride toothpaste (FT) on carious lesions.

Materials And Methods: Sixty extracted human premolars were prepared for artificial carious lesions with synthetic polymer gel. Read More

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Ultrasonic measurement of dentin remineralization effects of dentifrices and silver diamine fluoride.

Acta Odontol Scand 2021 Apr 6:1-8. Epub 2021 Apr 6.

Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan.

Objective: This study investigated the dentin remineralization effect of the application of a functionalized tri-calcium phosphate (fTCP) dentifrice and a silver diamine fluoride (SDF) solution.

Material And Methods: The materials used were: a fluoride-containing dentifrice with fTCP (fTCP+), a fluoride-containing dentifrice without fTCP (fTCP-) and a 38% SDF solution. Following treatment, the dentin slabs were immersed in a 0. Read More

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Diffraction manipulation of visible light with submicron structures for structural coloration fabrication.

Opt Express 2021 Mar;29(6):9294-9311

The structural coloration of glass induced by submicron structures is eco-friendly, ink-free, and has profound scientific significance. However, it is difficult to manufacture the submicron structures for glass optics due to the high hardness of glass and the miniature size of the microstructures. In this paper, the diffraction manipulation mechanism of groove shape to structural coloration and optimization theory are studied by establishing the theoretical and simulation mode. Read More

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Rapid fabrication technique for aluminum optics by inducing a MRF contamination layer modification with Ar ion beam sputtering.

Opt Express 2021 Mar;29(6):8951-8966

Aluminum optics are widely used in modern optical systems because of high specific stiffness and high reflectance. Magnetorheological finishing (MRF) provides a highly deterministic technology for high precision aluminum optics fabrication. However, the contamination layer will generate on the surface and bring difficulties for the subsequent processes, which highly limit the fabrication efficiency and precision. Read More

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Effect of FibroScan test in antiviral therapy for HBV-infected patients with ALT <2 upper limit of normal.

Open Life Sci 2020 22;15(1):418-422. Epub 2020 Jun 22.

Department of Gastroenterology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China.

Objective: The objective of this study is to detect the liver stiffness of hepatitis B virus (HBV)-infected patients with an alanine aminotransferase (ALT) level of <2 upper limit of normal (2ULN) by FibroScan and compare histological changes to assess the progression of liver lesions and its test results.

Methods: There were 36 patients who had a liver FibroScan degree of >7.3 KD (F1), and a liver biopsy was conducted. Read More

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Physical Characterization of Bismuth Oxide Nanoparticle Based Ceramic Composite for Future Biomedical Application.

Materials (Basel) 2021 Mar 26;14(7). Epub 2021 Mar 26.

Laboratorio de Investigacion de Materiles Dentales, Division de Estudios de Posgrado e Investigacion, Facultad de Odontologia, UNAM, Circuito de la Investigacion Cientifica, Alcaldia de Coyoacan, Ciudad Universitaria, 04510 Mexico, Mexico.

Employment and the effect of eco-friendly bismuth oxide nanoparticles (BiONPs) in bio-cement were studied. The standard method was adopted to prepare BiONPs-composite. Water was adopted for dispersing BiONPs in the composite. Read More

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Influence of Welding Speed on Fracture Toughness of Friction Stir Welded AA2024-T351 Joints.

Materials (Basel) 2021 Mar 22;14(6). Epub 2021 Mar 22.

Faculty of Mechanical Engineering, University of East Sarajevo, Vuka Karadžića 30, 71123 East Sarajevo, Bosnia and Herzegovina.

In order to ensure a quality welded joint, and thus safe operation and high reliability of the welded part or structure achieved by friction stir welding, it is necessary to select the optimal welding parameters. The parameters of friction stir welding significantly affect the structure of the welded joint, and thus the mechanical properties of the welded joint. Investigation of the influence of friction stir welding parameters was performed on 6-mm thick plates of aluminum alloy AA2024 T351. Read More

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Preparation, Thermal, and Thermo-Mechanical Characterization of Polymeric Blends Based on Di(meth)acrylate Monomers.

Polymers (Basel) 2021 Mar 12;13(6). Epub 2021 Mar 12.

Department of Polymer Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University, M. Curie-Skłodowska Sq.3., 20-031 Lublin, Poland.

This study presents the preparation and the thermo-mechanical characteristics of polymeric blends based on di(meth)acrylates monomers. Bisphenol A glycerolate diacrylate (BPA.GDA) or ethylene glycol dimethacrylate (EGDMA) were used as crosslinking monomers. Read More

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Incorporation of In Situ Synthesized Nano-Copper Modified Phenol-Formaldehyde Resin to Improve the Mechanical Properties of Chinese Fir: A Preliminary Study.

Polymers (Basel) 2021 Mar 12;13(6). Epub 2021 Mar 12.

International Center for Bamboo and Rattan, Beijing 100102, China.

Phenol-formaldehyde (PF) resin, modified using nano-copper with varying contents (0 wt%, 1 wt%, 3 wt%), was manufactured to improve the mechanical properties of Chinese fir. The morphology, chemical, micromechanical and micromechanical properties of the samples were determined by transmission electron microscopy (TEM), atomic force microscopy (AFM), environmental scanning electron microscopy (ESEM), Fourier transform infrared spectroscopy (FTIR), nanoindentation (NI) and traditional mechanical testing. The TEM and AFM results indicated that the in situ synthesized nano-copper particles were well-dispersed, and spherical, with a diameter of about 70 nm in PF resin. Read More

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The Strain Rate Sensitivity and Creep Behavior for the Tripler Plane of Potassium Dihydrogen Phosphate Crystal by Nanoindentation.

Micromachines (Basel) 2021 Mar 30;12(4). Epub 2021 Mar 30.

College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310014, China.

As an excellent multifunctional single crystal, potassium dihydrogen phosphate (KDP) is a well-known, difficult-to-process material for its soft-brittle and deliquescent nature. The surface mechanical properties are critical to the machining process; however, the characteristics of deformation behavior for KDP crystals have not been well studied. In this work, the strain rate effect on hardness was investigated on the mechanically polished tripler plane of a KDP crystal relying on nanoindentation technology. Read More

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An Improved Procedure for the Quality Control of Sintered Carbide Tips for Mining Applications, Based on Quantitative Image Analysis of the Microstructure.

Materials (Basel) 2021 Mar 5;14(5). Epub 2021 Mar 5.

Department of Machinery Engineering and Transport, Faculty of Mechanical Engineering and Robotics, AGH University of Science and Technology, 30-059 Kraków, Poland.

Conical picks are tools that treat surfaces used in mining. Due to a wide variety of such tools, they need to characterise in diversified geometrical and material parameters, as well as durability. For the mining sector, evaluation of the conical picks is performed in order to verify their agreement with the manufacturer's declaration, as well as with the requirements of the user. Read More

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Influence of Pulse Current Forward-Reverse Duty Cycle on Structure and Performance of Electroplated W-Cu Composite Coatings.

Materials (Basel) 2021 Mar 5;14(5). Epub 2021 Mar 5.

School of Materials Science and Engineering, Nanchang University, No. 999, Xuefu Avenue, Nanchang 330031, China.

Tungsten-copper (W-Cu) composites are widely used as electrical contact materials, resistance welding, electrical discharge machining (EDM), and plasma electrode materials due to their excellent arc erosion resistance, fusion welding resistance, high strength, and superior hardness. However, the traditional preparation methods pay little attention to the compactness and microstructural uniformity of W-Cu composites. Herein, W-Cu composite coatings are prepared by pulse electroplating using nano-W powder as raw material and the influence of forward-reverse duty cycle of pulse current on the structure and mechanical properties is systematically investigated. Read More

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On the Use of EBSD and Microhardness to Study the Microstructure Properties of Tungsten Samples Prepared by Selective Laser Melting.

Materials (Basel) 2021 Mar 4;14(5). Epub 2021 Mar 4.

Laser College of Engineering, Beijing University of Technology, Beijing 100124, China.

Additively manufactured tungsten and its alloys have been widely used for plasma facing components (PFCs) in future nuclear fusion reactors. Under the fusion process, PFCs experience a high-temperature exposure, which will ultimately affect the microstructural features, keeping in mind the importance of microstructures. In this study, microhardness and electron backscatter diffraction (EBSD) techniques were used to study the specimens. Read More

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Properties of WC-10%Co-4%Cr Detonation Spray Coating Deposited on the Al-4%Cu-1%Mg Alloy.

Materials (Basel) 2021 Mar 4;14(5). Epub 2021 Mar 4.

Department of Materials Science, Physical and Chemical Properties of Materials, South Ural State University, 76 Lenin Av., Chelyabinsk 454080, Russia.

One of the methods of local improvement of the wear resistance of aluminum alloy parts is the deposition of hard tungsten carbide-based coatings on the surfaces subjected to intense external influence. This paper is devoted to the characterization of the WC-10Co-4Cr (wt.%) coating deposited on an Al-4Cu-1Mg (wt. Read More

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Fracture Analysis of High-Strength Screw for Highway Construction.

Materials (Basel) 2021 Mar 25;14(7). Epub 2021 Mar 25.

Department of Marketing, Oleg Balatskyi Academic and Research Institute of Finance, Economics and Management, Sumy State University, 2 Rymskogo-Korsakova St., 40007 Sumy, Ukraine.

High-strength screws represent one of the main joining or fastening components which are commonly used in the process of installation of frame constructions for information boards or signposts, relating to the traffic roads. The control of the production process may not always be a sufficient method for ensuring road safety. The backward investigation and control of the screw material processing seems to be the one of the most important procedures when there is the occurrence of any failure during the operation of the screw. Read More

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Selective Deposition of Hard Boron-Carbon Microstructures on Silicon.

Materials (Basel) 2021 Mar 13;14(6). Epub 2021 Mar 13.

Department of Physics, University of Alabama at Birmingham, Birmingham, AL 35294, USA.

Boron-rich B-C compounds with high hardness have been recently synthesized by the chemical vapor deposition (CVD) method. In this paper, we present our successful efforts in the selective growth of microstructures of boron-carbon compounds on silicon substrates. This was achieved by combining microfabrication techniques such as maskless lithography and sputter deposition with the CVD technique. Read More

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Investigation into the Structural, Chemical and High Mechanical Reforms in BC with Graphene Composite Material Substitution for Potential Shielding Frame Applications.

Molecules 2021 Mar 29;26(7). Epub 2021 Mar 29.

Department of Mechanical and Industrial Engineering, College of Engineering, Majmaah University, Al-Majmaah, Riyadh 11952, Saudi Arabia.

In this work, boron carbide and graphene nanoparticle composite material (BC-G) was investigated using an experimental approach. The composite material prepared with the two-step stir casting method showed significant hardness and high melting point attributes. Scanning electron microscopy (SEM), along with energy dispersive X-ray spectroscopy (EDS) analysis, indicated 83. Read More

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Comparison of Different Cermet Coatings Sprayed on Magnesium Alloy by HVOF.

Materials (Basel) 2021 Mar 24;14(7). Epub 2021 Mar 24.

Department of Engineering Materials and Biomaterials, Silesian University of Technology, Konarskiego St. 18a, 44-100 Gliwice, Poland.

In the present study, two different cermet coatings, WC-CrC-Ni and CrC-NiCr, manufactured by the high-velocity oxy-fuel (HVOF) method were studied. They are labeled as follows: WC-CrC-Ni coating-WC and CrC-NiCr coating-CrC. These coatings were deposited onto a magnesium alloy (AZ31) substrate. Read More

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The Effect of Chip Binding on the Parameters of the Case-Hardened Layer of Tooth Surfaces for AMS 6308 Steel Gears Processed by Thermochemical Treatment.

Materials (Basel) 2021 Mar 1;14(5). Epub 2021 Mar 1.

Department of Materials Science, Faculty of Mechanical Engineering and Aeronautics, Ignacy Łukasiewicz Rzeszów University of Technology, Powstańców Warszawy 12, 35-959 Rzeszów, Poland.

The following article describes influence of pressure welded or bound chips to the gear tooth flank and/or the tooth root on a carburized case and surface layer hardness of Pyrowear 53 steel gears, machined by Power Skiving method. This paper is focused only on one factor, the chips generated while forming gear teeth by power skiving, which could result in local changes in the carburized case parameters as a negatively affecting point of mechanical performance of the carburized case. The chips, due to the specifics of the power skiving process and the kinematics of tooth forming, could be subject to the phenomena of pressure welding or binding of chips to the tooth. Read More

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Effect of Different Fermentation Condition on Estimated Glycemic Index, In Vitro Starch Digestibility, and Textural and Sensory Properties of Sourdough Bread.

Foods 2021 Mar 1;10(3). Epub 2021 Mar 1.

Department of Food Engineering, Faculty of Chemical and Metallurgical Engineering, Yildiz Technical University, Istanbul 34210, Turkey.

This study aimed to evaluate the influence of sourdough fermentation on the estimated glycemic index (eGI), in vitro starch digestibility, and textural and sensory properties of eight experimentally prepared sourdough breads. Wheat and whole wheat flour bread samples were produced under different fermentation conditions (25 °C and 30 °C) and fermentation methods (type-1 and type-2). In type-1 fermentation, sourdough was obtained via spontaneous fermentation. Read More

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Full Optimization of an Electroless Nickel Solution: Boosting the Performance of Low-Phosphorous Coatings.

Materials (Basel) 2021 Mar 18;14(6). Epub 2021 Mar 18.

CIDETEC, Basque Research and Technology Alliance (BRTA), E-20014 Donostia-San Sebastián, Spain.

Univariate and multivariate optimizations of a novel electroless nickel formulation have been carried out by means of the Taguchi method. From the compositional point of view, adjustment of the complexing agent concentration in solution is crucial for fine-tuning free Ni ions concentration and, in turn, the mechanical properties of the resulting coatings. The Ni (II) concentration and the pH are the main parameters which help restrict the incorporation of phosphorous into the Ni layers. Read More

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A Novel Approach by Spark Plasma Sintering to the Improvement of Mechanical Properties of Titanium Carbonitride-Reinforced Alumina Ceramics.

Molecules 2021 Mar 3;26(5). Epub 2021 Mar 3.

Łukasiewicz Research Network-Cracow Institute of Technology, Centre of Advance Manufacturing Technology, 73 Zakopianska St., 30-418 Cracow, Poland.

Ti(C,N)-reinforced alumina-zirconia composites with different ratios of C to N in titanium carbonitride solid solutions, such as Ti(C,N) (C:N = 30:70) and Ti(C,N) (C:N = 50:50), were tested to improve their mechanical properties. Spark plasma sintering (SPS) with temperatures ranging from 1600 °C to 1675 °C and pressureless sintering (PS) with a higher temperature of 1720 °C were used to compare results. The following mechanical and physical properties were determined: Vickers hardness, Young's modulus, apparent density, wear resistance, and fracture toughness. Read More

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