Evaluation of pin penetration probing technique for the assessment of basic density in air-dried wood

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 6577-6586
Author(s):  
Ebrahim Khosravi ◽  
Mehran Roohnia ◽  
Amir Lashgari ◽  
Ahmad Jahanlatibari ◽  
Ajang Tajdini
Keyword(s):  
Basic Density ◽  
Physical And Mechanical Properties ◽  
Traditional Methods ◽  
Exponential Relationship ◽  
Static Tests ◽  
Density Values ◽  
Density Evaluation ◽  
Moisture Conditions ◽  
Non Destructive

Fast and accurate evaluation of the physical and mechanical properties of engineering ‎materials is of particular importance. The in situ semi-destructive and non-destructive tests versus the ‎static tests for determining the time-consuming physical properties have replaced many traditional ‎methods with reasonable accuracies. Determining the density as one of ‎the most important qualitative and quantitative parameters in the inspection of wood and wood-based ‎products is of great importance. For this purpose, 33 wood specimens from 11 species with varying densities were tested by pin penetration probing. Results were compared with those from ‎the basic density values from traditional methods. The results showed an exponential relationship between the pin penetration depths ‎and the basic density considering the moisture conditions but without any problems. The coefficients of ‎determination while estimating the equality of the basic density via pin penetration probing with the actual ‎basic density for both the testing specimens and the control samples were always over ‎‎0.8. Henceforth, this methodology suggested that the density evaluation could inspire higher precision than what has been achieved in previous efforts.

Weathering conditions of Buddhist caves dug in soft rocks and conservation attempting from the deterioration

2021 ◽  
Author(s):  
Chiaki Oguchi ◽  
Momoko Ogawa ◽  
Kaisei Sakane ◽  
Yasuhiko Tamura
Keyword(s):  
Environmental Monitoring ◽  
Layer Structure ◽  
Physical And Mechanical Properties ◽  
Small Scale ◽  
Central Japan ◽  
Soft Rocks ◽  
Geologic Materials ◽  
Temperature And Humidity ◽  
Non Destructive

<p>The Taya Cave, a sacred Buddhist cave, locates in the precincts of Josenji Temple in Yokohama City, central Japan. The geologic materials of the hills surrounding the cave are soft rocks composed of early Quaternary sedimentary rocks. The cave has a complex three-layer structure with a total length of 570 m. The excavation of the cave is estimated to start in the Kamakura era around A.D. 1200. Since then, the cave became a training place for Buddhists until around 19 C. There are many Buddhist reliefs on the walls and ceiling inside the cave. Because the bedrock is extremely weak, the rocks easily break when they get wet again after drying, namely prone to slaking. Thus, weathering and deterioration have progressed in various parts of the cave. Many valuable Buddhist reliefs have damaged by exfoliation. The walls at several points in the cave have also collapsed on a small scale. Therefore, it is necessary to investigate such deteriorated parts in the cave by simple non-destructive tests of physical and mechanical properties by using Silver Schmidt hammer and ultrasonic velocity test. These measurements clarified the vulnerable points even in the main worship route of the cave. In October 2018, a stainless-steel door installed at the cave entrance to save from deterioration due to slaking. The effect of the door was verified as well by monitoring the environmental conditions inside the cave. Environmental monitoring results revealed that the temperature and humidity near the entrance changed most drastically in this cave. Although the door was closed only at night, the range of maximum and minimum values ​​of temperature and humidity near the entrance became smaller after installation than before. Non-destructive measurements and in situ environmental monitoring are a useful way to assess weathering without damaging geoarchaeological sites. </p>

scholarly journals Pecularities of Strength Assessment of Cast-in-Situ Structures in Terms of Siberia

2020 ◽  
Vol 839 ◽  
pp. 43-50
Author(s):  
Irina G. Endzhievskaya ◽  
Iliya G. Kalugin ◽  
Sergey O. Deygraf ◽  
Maksim A. Galkin
Keyword(s):  
Concrete Strength ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Design Strength ◽  
Plant Laboratory ◽  
Strength Assessment ◽  
Integrated Research ◽  
Strength Based ◽  
Non Destructive

This article states the results of experimental studies to assess concrete strength in cast-in-situ structures based on a systematic approach, including integrated research methods at all stages of construction of reinforced concrete structures. It was established that the concrete strength of the sample-cubes made on the object simultaneously with the structure and stored under the same conditions was slightly lower than the structures and standard control samples. The decrease in the strength of concrete samples from structures is on average 13,3%. Its value is effected by several factors, one of the main was the maintenance of the structure. The most appropriate is to meet the requirements of achieving 70% of the design strength and higher percentage is required for cast-in-situ construction in terms of winter pouring concrete. At the same time, along with the assessment of the physical and mechanical properties of the structure by non-destructive methods, it is necessary to carry out tests aimed at determining the actual concrete strength based on samples made in the batching plant laboratory and solidified (cured) in permissible humidity conditions (herein after referred as PHC).

scholarly journals COMPARATIVE SURFACE DAMAGE DETERMINATION AT A JEWISH GRAVE USING TWO DIFFERENT MOBILE ULTRASONIC VELOCITY DEVICES

2017 ◽  
Vol 50 (3) ◽  
pp. 1626 ◽  
Author(s):  
B. Christaras ◽  
An. Moropoulou ◽  
M. Chatziangelou ◽  
L. Dimitraki ◽  
K. Devlioti
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Surface Damage ◽  
P Wave ◽  
University Campus ◽  
Ultrasonic Velocities ◽  
Wave Velocities ◽  
Non Destructive ◽  
Destructive Methods

The non-destructive methods are necessary in the investigation of the physical and mechanical properties of the materials in monuments. In this framework the ultrasonic velocities were used in situ for the elaboration and evaluation of the weathering on the surfaces of monuments. Additionally, the P-wave velocities were used for the estimation of the depth of weathered zone, as well as the depth of cracks at the surface of the monument. This estimation was performed on a Jewish tomb placed in the AUTH university campus between the building of Law and Economic Sciences and the Administration building, of the Aristotle University of Thessaloniki. 

Determining elastic properties of sedimentary strata in terms of limestone samples by laser ultrasonics

2020 ◽  
pp. 125-134
Author(s):  
I. A. Shibaev ◽  
V. A. Vinnikov ◽  
G. D. Stepanov
Keyword(s):  
Physical And Mechanical Properties ◽  
Laser Ultrasonics ◽  
Compression Tests ◽  
S Waves ◽  
Static Modulus ◽  
Enhance Efficiency ◽  
Static Modulus Of Elasticity ◽  
Static Elastic Moduli ◽  
Non Destructive ◽  
Moduli Of Elasticity

Geological engineering often uses geomechanical modeling aimed to enhance efficiency of mining or performance of structures. One of the input parameters for such models are the static elastic moduli of rocks. This article presents the studies into the physical and mechanical properties of rocks-limestone of non-metamorphic diagenesis. The precision measurements of Pand S-waves are carried out to an accuracy of 0.2% by laser ultrasonics. The static moduli of elasticity and the deformation characteristics of rocks are determined in the uniaxial compression tests by the standards of GOST 21153.2-84 and GOST 28985-91, respectively. The correlation dependence is found between the static and dynamic elasticity moduli in limestone samples. The found correlation allows drawing the conclusion that the static modulus of elasticity can be estimated in non-destructive tests, which largely simplifies preliminary diagnostics of samples in case of limited number of test core.

scholarly journals Laser-excited elastic guided waves reveal the complex mechanics of nanoporous silicon

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Marc Thelen ◽  
Nicolas Bochud ◽  
Manuel Brinker ◽  
Claire Prada ◽  
Patrick Huber
Keyword(s):  
Guided Waves ◽  
Laser Ultrasonics ◽  
Bulk Silicon ◽  
Nanoporous Silicon ◽  
Stiffness Reduction ◽  
Mechanical Characterisation ◽  
Isotropic Elasticity ◽  
On Chip ◽  
Non Destructive

AbstractNanoporosity in silicon leads to completely new functionalities of this mainstream semiconductor. A difficult to assess mechanics has however significantly limited its application in fields ranging from nanofluidics and biosensorics to drug delivery, energy storage and photonics. Here, we present a study on laser-excited elastic guided waves detected contactless and non-destructively in dry and liquid-infused single-crystalline porous silicon. These experiments reveal that the self-organised formation of 100 billions of parallel nanopores per square centimetre cross section results in a nearly isotropic elasticity perpendicular to the pore axes and an 80% effective stiffness reduction, altogether leading to significant deviations from the cubic anisotropy observed in bulk silicon. Our thorough assessment of the wafer-scale mechanics of nanoporous silicon provides the base for predictive applications in robust on-chip devices and evidences that recent breakthroughs in laser ultrasonics open up entirely new frontiers for in-situ, non-destructive mechanical characterisation of dry and liquid-functionalised porous materials.

Localized Corrosion of Binary Mg-Nd Alloys in Chloride-Containing Electrolyte Using a Scanning Vibrating Electrode Technique

CORROSION ◽  
2012 ◽  
Vol 68 (6) ◽  
pp. 489-498 ◽  
Author(s):  
G. Williams ◽  
K. Gusieva ◽  
N. Birbilis
Keyword(s):  
Localized Corrosion ◽  
Radial Expansion ◽  
Alloying Additions ◽  
Corrosion Rates ◽  
Surface Breakdown ◽  
Density Values ◽  
Intact Surface ◽  
Mean Current ◽  
Electrode Technique

The influence of neodymium (Nd) alloying additions in the 0.47 wt% to 3.53 wt% range on the localized corrosion behavior of Mg, when freely corroding in aqueous sodium chloride (NaCl) electrolyte, is investigated using an in situ scanning vibrating electrode technique (SVET). For all samples, the point of surface breakdown is an intense focal anode that expands radially with respect to time, revealing a cathodically activated interior, which is galvanically coupled with the local anode at the perimeter. However, for Nd compositions of ≤0.74%, radial expansion ceases within ca. 2 h of initiation, whereupon dark filiform-like corrosion features are observed, which traverse over the exposed Mg surface. For Nd additions of ≥1.25%, the radial expansion continues with time up to a point where the entire intact surface becomes consumed. The intensity of the local anode ring of circular corroded regions is seen to increase as more cathodically activated corroded surface becomes exposed. Mean current density values measured within these corroded areas increase progressively with Nd content, leading to a progressive rise in localized corrosion rates. The cathodic activation of corroded regions is proposed to derive from an enrichment of noble, Nd-rich intermetallic grains caused as the alpha-Mg phase becomes attacked at local anode sites.

Effect of pouring temperature on A356-TiB2 MMCs cast in sand and permanent moulds by in-situ method

2016 ◽  
Vol 25 (5-6) ◽  
pp. 165-169
Author(s):  
C. Rajaravi ◽  
P.R. Lakshminarayanan
Keyword(s):  
Evaluation Studies ◽  
Physical And Mechanical Properties ◽  
Xrd Analysis ◽  
Matrix Composites ◽  
Structure Property ◽  
Pouring Temperature ◽  
Matrix Metal ◽  
Property Evaluation ◽  
The Matrix

AbstractThe paper describes a different condition of pouring temperature by sand and permanent mould to produce A356-6 wt% TiB2 metal matrix composites by in-situ method salt metal reaction route. The observation of SEM micrographs shows particle distribution of the TiB2 and it appears in hexagonal shape in Al matrix. The results of X-ray diffraction (XRD) analysis confirmed the formation of those TiB2 particulates and the results showed TiB2 particles are homogeneously dispersed throughout the matrix metal. Subsequent structure-property evaluation studies indicated sub-micron size reinforcement of in-situ formed TiB2 particles with improved physical and mechanical properties as compared to sand and permanent mould of Al-TiB2 composites. From, the permanent mould Al-TiB2 composite has an advantage of increase the properties over sand mould Al-TiB2 composite.

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