Influence of Fungi on the State of Preservation and on the Usage Prospects of Antique Wooden Floor from Manor Houses in South-Eastern Poland

Floor structures are an integral part and a valuable element of antique buildings, and the only limitation of their preservation consists in their usage properties. A thorough study of their state of preservation is the starting point for choosing the correct conservation programmes. Currently, fungi are the main reason that leads to the replacement of antique wooden parquets in Poland. Simple visual inspections in many cases do not ensure a precise evaluation of the level of fungal infestation and the depth of penetration of the myceliums hyphae in the wood. Tests of ergosterol, which is a component of most fungis cell membrane, allow us to monitor the level of fungi infestation of diverse materials. This makes it possible to determine the depth of mycelium penetration within the wood quite precisely. Unfortunately, in case of basidiomycota it is not possible to correlate ergosterol with the myceliums biomass nor with the grade of wood degradation. Moreover, tests of ergosterol are not able to answer the question whether the fungi infestation is active, because this substance is also present in dead fungi hyphae. The presence of ergosterol in the wood can only give us a hint of presence of a substrate mycelium, which is responsible for the secretion of exoenzymes that degrade structural substances. Therefore, only the test results of ergosterol content and of the woods chemical composition, wettability curve and moisture equivalent, as well as computer simulations of its capacity to transfer own and usage loads (on the basis of the elasticity modulus, bending strength and wood density) together with the hardness, resistance to abrasion and resistance to scratches of wooden parquets permit us to take a correct decision as to the possibility of their further usage. The research carried out shows that, in many cases, parquets infested with fungi can be used safely. The article presents the proprieties that are important in the correct assessment of antique wooden parquets state of preservation and usage prospects. It specifies the factors that permit to eliminate the problem of fungi infestation and describes the proper usage conditions, proposing efficient methods of conservation.

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Testing and Assessing Method for the Resistance of Wood-Plastic Composites to the Action of Destroying Fungi

Materials ◽

10.3390/ma14030697 ◽

2021 ◽

Vol 14 (3) ◽

pp. 697

Author(s):

Anna Wiejak ◽

Barbara Francke

Keyword(s):

Bending Strength ◽

Test Results ◽

Negative Effects ◽

Destructive Effect ◽

Wood Plastic Composites ◽

Plastic Composites ◽

Wood Polymer ◽

Proposed Modification ◽

Assessing Method ◽

Biological Corrosion

Durability tests against fungi action for wood-plastic composites are carried out in accordance with European standard ENV 12038, but the authors of the manuscript try to prove that the assessment of the results done according to these methods is imprecise and suffers from a significant error. Fungi exposure is always accompanied by high humidity, so the result of tests made by such method is always burdened with the influence of moisture, which can lead to a wrong assessment of the negative effects of action fungus itself. The manuscript has shown a modification of such a method that separates the destructive effect of fungi from moisture accompanying the test’s destructive effect. The functional properties selected to prove the proposed modification are changes in the mass and bending strength after subsequent environmental exposure. It was found that intensive action of moisture measured in the culture chamber of about (70 ± 5)%, i.e., for 16 weeks, at (22 ± 2) °C, which was the fungi culture, which was accompanying period, led to changes in the mass of the wood-plastic composites, amounting to 50% of the final result of the fungi resistance test, and changes in the bending strength amounting to 30–46% of the final test result. As a result of the research, the correction for assessing the durability of wood-polymer composites to biological corrosion has been proposed. The laboratory tests were compared with the products’ test results following three years of exposure to the natural environment.

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A Comparison of Three Ways to Measure Time-Dependent Densities With Quantum Simulators

Frontiers in Physics ◽

10.3389/fphy.2021.546538 ◽

2021 ◽

Vol 9 ◽

Author(s):

Jun Yang ◽

James Brown ◽

James Daniel Whitfield

Keyword(s):

Density Functional ◽

Quantum Algorithms ◽

Quantum Circuit ◽

Time Dependent ◽

Test Results ◽

Functional Theory ◽

Virtual Device ◽

Starting Point ◽

Intractable Problems ◽

Harmonic Inversion

Quantum algorithms are touted as a way around some classically intractable problems such as the simulation of quantum mechanics. At the end of all quantum algorithms is a quantum measurement whereby classical data is extracted and utilized. In fact, many of the modern hybrid-classical approaches are essentially quantum measurements of states with short quantum circuit descriptions. Here, we compare and examine three methods of extracting the time-dependent one-particle probability density from a quantum simulation: direct Z-measurement, Bayesian phase estimation, and harmonic inversion. We have tested these methods in the context of the potential inversion problem of time-dependent density functional theory. Our test results suggest that direct measurement is the preferable method. We also highlight areas where the other two methods may be useful and report on tests using Rigetti's quantum virtual device. This study provides a starting point for imminent applications of quantum computing.

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STUDI KUAT LENTUR BETON DENGAN BAHAN TAMBAH SERAT ABAKA

Teras Jurnal ◽

10.29103/tj.v11i1.364 ◽

2021 ◽

Vol 11 (1) ◽

pp. 53

Author(s):

Yudi Pranoto ◽

Lina Halim ◽

Anung Sudibyo

Keyword(s):

Flexural Strength ◽

Bending Strength ◽

Fiber Content ◽

Mix Design ◽

Fine Aggregate ◽

Test Results ◽

Concrete Mix Design ◽

Banana Tree ◽

Flexible Fiber ◽

Test Objects

Abstrak Serat abaka merupakan serat yang awet dan lentur yang diambil dari pohon pisang. Serat ini masih sangat jarang dimanfaatkan, sementara di Indonesia serat abaka bisa ditemukan di mana mana. Tujuan penelitian ini adalah untuk mengetahui sejauh mana pengaruh serat abaka terhadap kuat lentur beton. Penelitian ini diawali dengan studi literature, pengujian material (Agregat halus, agregat kasar, semen dan serat abaka), mix design beton, pembuatan benda uji, perawatan dan dilanjutkan dengan pengujian kuat lentur beton serta terakhir dilakukan analisis hasil pengujian. Dari hasil pengujian didapatkan kuat lentur maksmum terjadi pada kadar serat abaka sebesar 0,6% dengan kuat lentur 3,75 MPa, sedangkan kuat lentur terkecil terjadi pada kadar serat abaka 0% dengan kuat lentur 3,34 MPa. Kata kunci: serat abaka, kuat lentur, mix deisgn Abstract Abaca fiber is a durable and flexible fiber taken from the banana tree. This fiber is still very rarely used, while in Indonesian abaca fiber can be found everywhere. The purpose of this study was to determine the extent of the influence of abaca fiber on the flexural strength of concrete. This research begins with literature studies, material testing (fine aggregate, coarse aggregate, cement, and abaca fiber), concrete mix design, manufacture of test objects, curing, and continues with concretes flexural strength testing and finally an analysis of the test results. From the test results, it founded that the maximum flexural strength occurred at the abaca fiber content of 0.6% with a bending strength of 3.75 MPa, and the smallest flexural strength occurred at 0% abaca fiber content with a flexural strength of 3.34 MPa. Keywords: Abaka fiber, flexural strength, mix design

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EFFECT OF CALCIUM SULFOALUMINATE ADDITIVE ON LINEAR DEFORMATION AT DIFFERENT HUMIDITY AND STRENGTH OF CEMENT MORTARS

Inżynieria Bezpieczeństwa Obiektów Antropogenicznych ◽

10.37105/iboa.64 ◽

2020 ◽

Author(s):

Kadhim Abdulwahid Al-Musawi ◽

Kottayil Bindhu Abraham ◽

Tatsiana Potses ◽

Sergey Leonovich ◽

Natallia Kalinouskaya ◽

...

Keyword(s):

Bending Strength ◽

High Humidity ◽

Test Results ◽

High Quality ◽

Linear Deformation ◽

Calcium Sulfoaluminate ◽

Environmental Humidity ◽

Cement Mortars ◽

Under Construction ◽

Very High

The effect of calcium sulfoaluminate additives (CSA) on the compression and bending strength of mortar, as well as linear deformation of prism samples at different environmental humidity was studied. Test results indicate that bending strength of mortars with CSA and the referent at the age of 28 days are practically equal. Compressive strength of mortars with CSA reduced by 20 ... 23% for all dosages of CSA. Relative linear deformations depend on the humidity of the environment. At a humidity of 100%, the relative linear deformations are positive and the expansion increases with increasing dosage of the expanding additive. When hardening in dry air at a humidity of 55%, the greatest shrinkage deformations were for mortars with CSA. We can conclude that the expanding effect of CSA is fully manifested at high humidity, i.e. under construction conditions, this means very high-quality moisture care for concrete structures.

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Effective Polymer Protective Coatings

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.410.542 ◽

2021 ◽

Vol 410 ◽

pp. 542-547

Author(s):

Elena S. Dergunova ◽

German S. Dedyaev ◽

Margarita A. Goncharova

Keyword(s):

Compressive Strength ◽

Epoxy Resins ◽

Bending Strength ◽

Elasticity Modulus ◽

Chemical Resistance ◽

Protective Coatings ◽

Resistance Coefficient ◽

Curing Process ◽

High Elasticity ◽

Mesh Density

New protective coating compositions based on epoxy resins with high rates of chemical resistance to etching solutions are developed. The chemical resistance coefficient ranges from 0.7 to 0.96. The curing process was evaluated via IR spectroscopy. For each composition, the following parameters were determined: impact strength A, compressive strength σcompr and bending strength σbend, adhesion shear strength σshear, glass transition temperature Tgt, high elasticity modulus Eh and mesh density nm.

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Bending Strength of Al2O3 Ceramics for Textiles Machinery and Elastic Wave Characteristics by Wavelet Analysis

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.353-358.345 ◽

2007 ◽

Vol 353-358 ◽

pp. 345-348

Author(s):

Ki Woo Nam ◽

B.G. Ahn ◽

M.K. Kim ◽

C.S. Son ◽

Jin Wook Kim ◽

...

Keyword(s):

Elastic Wave ◽

Bending Strength ◽

Test Results ◽

Composite Ceramics ◽

Bending Tests ◽

Three Point Bending ◽

Wave Signal ◽

Al2o3 Composite ◽

Signal Characteristics ◽

Optimized Conditions

The optimized conditions of pressureless sintering were investigated in order to obtain the bending strength and the elastic wave signal of Al2O3 composite ceramics for textiles machinery. As sintering conditions, a temperature range from 1400°C to 1700°C and time from 30 minutes to 150 minutes were applied. Three-point bending tests were conducted on the sintered materials to obtain the strength property. From the test results, the optimum sintering condition was 1600°C, 100 minutes. Al2O3 composite ceramics showed that the elastic wave signal characteristics had a regular correlativity between the optimum sintering temperature and time as well as the maximum bending strength.

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Fracture Toughness Analysis of Epoxy-Recycled Rubber-Based Composite Reinforced with Graphene Nanoplatelets for Structural Applications in Automotive and Aeronautics

Polymers ◽

10.3390/polym12020448 ◽

2020 ◽

Vol 12 (2) ◽

pp. 448 ◽

Cited By ~ 3

Author(s):

Alaeddin Burak Irez ◽

Emin Bayraktar ◽

Ibrahim Miskioglu

Keyword(s):

Fracture Toughness ◽

Building Materials ◽

Bending Strength ◽

Mechanical Test ◽

Graphene Nanoplatelets ◽

Test Results ◽

Toughening Mechanisms ◽

Structural Applications ◽

Recycled Rubber ◽

Cost Efficient

This study proposes a new design of lightweight and cost-efficient composite materials for the aeronautic industry utilizing recycled fresh scrap rubber, epoxy resin, and graphene nanoplatelets (GnPs). After manufacturing the composites, their bending strength and fracture characteristics were investigated by three-point bending (3PB) tests. Halpin–Tsai homogenization adapted to composites containing GnPs was used to estimate the moduli of the composites, and satisfactory agreement with the 3PB test results was observed. In addition, 3PB tests were simulated by finite element method incorporating the Halpin–Tsai homogenization, and the resulting stress–strain curves were compared with the experimental results. Mechanical test results showed that the reinforcement with GnPs generally increased the modulus of elasticity as well as the fracture toughness of these novel composites. Toughening mechanisms were evaluated by SEM fractography. The typical toughening mechanisms observed were crack deflection and cavity formation. Considering the advantageous effects of GnPs on these novel composites and cost efficiency gained by the use of recycled rubber, these composites have the potential to be used to manufacture various components in the automotive and aeronautic industries as well as smart building materials in civil engineering applications.

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Study on Durability of High Bending Strength Pavement Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.594-597.1372 ◽

2012 ◽

Vol 594-597 ◽

pp. 1372-1376

Author(s):

Wei Hong Guo

Keyword(s):

Wear Resistance ◽

Bending Strength ◽

Drying Shrinkage ◽

Fatigue Property ◽

Plain Concrete ◽

Shrinkage Strain ◽

Test Results ◽

Concrete Material ◽

Shrinkage Coefficient ◽

Pavement Concrete

In order to explore the durability of high bending strength pavement concrete, adding silica flour, fibrous reticulum, SD emulsion and HG emulsion separately in concrete mixture, the shrinkage characteristic, wear resistance and fatigue property of different high bending strength pavement concrete are tested, and contrastive analysis with the plain concrete material is researched. The test results show that the early contraction of HBSPC is bigger, but the total drying shrinkage strain is smaller than plain concrete, and the drying shrinkage stable stage of HBSPC is shorter than plain concrete. The temperature shrinkage of HBSPC and plain concrete is uniform basically, the temperature shrinkage coefficient of HBSPC is lower than the plain concrete in the negative warm area and warm area, but it is higher in 0 °C neighbor. The mixtures of the material enhance the wear resistance and fatigue property of concrete.

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Effect of Emulsified Asphalt Content on Mechanical Property of Cement and Emulsified Asphalt Mortar

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.587-589.1132 ◽

2014 ◽

Vol 587-589 ◽

pp. 1132-1136

Author(s):

Yue Li ◽

Ping Wang

Keyword(s):

Compressive Strength ◽

Bending Strength ◽

Bending Test ◽

Test Machine ◽

Peak Strain ◽

Test Results ◽

Slurry System ◽

Similar Appearance ◽

Emulsified Asphalt ◽

Ca Mortar

Uniaxial compression and bending test of CA mortar, which have six different dosage of emulsified asphalt and the same dry material, is carried out with a electronic universal test machine. It turns out that: when the dosage of emulsified asphalt is lacked, the CA mortar cannot be uniform and stable slurry system; within the range of 300~680 mL emulsified asphalt, slurry state of mortar is good, no separation, and have good liquidity, in this range, with the increasing dosage of emulsified asphalt, compressive strength, elastic modulus and peak strain are gradually reduced, while ratio of bending strength to compressive strength rise at the beginning, then decline within a narrow range; The 1st and 2nd slurry is not stable, they appear separation and the surfaced asphalt, which have similar appearance and mechanical properties to cement mortar, and the last four groups of test results have great difference from the former two groups.

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BEHAVIOUR OF HOLLOW CONCRETE‐FILLED STEEL TUBULAR COMPOSITE ELEMENTS

Journal of Civil Engineering and Management ◽

10.3846/13923730.2007.9636429 ◽

2007 ◽

Vol 13 (2) ◽

pp. 131-141 ◽

Cited By ~ 22

Author(s):

Artiomas Kuranovas ◽

Audronis Kazimieras Kvedaras

Keyword(s):

Stress State ◽

Elasticity Modulus ◽

Complex Stress ◽

Steel Tube ◽

Complex Stress State ◽

Test Results ◽

Load Bearing Capacity ◽

Concrete Core ◽

Theoretical Investigations ◽

Concrete Elements

Behaviour of composite steel‐concrete elements in various loading stages is quite well analysed by theoretical investigations and experiments. Concrete‐Filled Steel Tube (CFST) is one of many composite elements used at present in civil engineering. Different approaches and design philosophies were adopted in different design codes for it. But for hollow CFST elements, which are more effective than ordinary CFST, any code does not provide information about how to design these elements. Further investigations of hollow composite CFST elements are needed. In loading stage, when a particular level of stresses exists, an interaction between steel tube and concrete core appears and therefore a complex stress state of element takes place, which increases the load‐bearing capacity of the whole composite element. This interaction between components of CFST elements is reached because of different material properties, such as Poisson's ratio, elasticity modulus etc. In this article reasons of the above‐mentioned complex stress state appearance and behaviour of hollow CFST element components in different load stages of compressed stub structural member are analysed. The test results are presented in diagrams, tables. Previous researches of other investigators are summarised. Differences and similarities in behaviour of solid concrete and composite elements and hollow members with different number of concrete core layers are discussed.

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