scholarly journals ENERGY SAVING OF WOOD DUE TO ITS MODIFICATION

2021 ◽  
Author(s):  
Tamara Storodubtseva ◽  
A. Buryakova ◽  
A. Rabotkin
Keyword(s):  
Corrosion Resistance ◽  
Chemical Modification ◽  
Thermomechanical Processing ◽  
Radiation Chemical ◽  
Mineral Oils ◽  
High Heating ◽  
Natural Wood ◽  
Thermochemical Modification ◽  
Further Development ◽  
Modified Wood

Modified wood is wood that is improved with special modifiers in order to increase its strength, durability and water-, bio-, fire- and corrosion resistance, which, unlike natural wood, makes it more resistant to various environmental factors. This wood is good to use in construction, and it will be effective for further development, as the buildings will be used longer, and less likely to be subject to repair and reconstruction, which will reduce deforestation. The most popular methods of modification are thermomechanical modification with preliminary steaming of wood, its heating, or with preliminary impregnation with mineral oils; thermochemical modification; chemical modification; radiation-chemical modification. Each type of the above modifications differs in its properties, and also have their own impact on a particular type of wood. The most common and most effective method of modification is achieved by thermomechanical processing. Since it is when the wood is heated, after the introduction of the necessary modifiers into it, the polymers begin to heat up, due to which the vessels of the wood harden, which affects its density. To avoid the destruction of wood, it is very important to monitor the temperature and prevent it from reaching high heating levels.

scholarly journals Review of Functional Treatments for Modified Wood

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 327
Author(s):  
Morwenna J. Spear ◽  
Simon F. Curling ◽  
Athanasios Dimitriou ◽  
Graham A. Ormondroyd
Keyword(s):  
High Performance ◽  
Responsive Materials ◽  
Wood Modification ◽  
Wide Range ◽  
Natural Wood ◽  
Impregnation Modification ◽  
New Applications ◽  
New Generation ◽  
Dimensional Instability ◽  
Modified Wood

Wood modification is now widely recognized as offering enhanced properties of wood and overcoming issues such as dimensional instability and biodegradability which affect natural wood. Typical wood modification systems use chemical modification, impregnation modification or thermal modification, and these vary in the properties achieved. As control and understanding of the wood modification systems has progressed, further opportunities have arisen to add extra functionalities to the modified wood. These include UV stabilisation, fire retardancy, or enhanced suitability for paints and coatings. Thus, wood may become a multi-functional material through a series of modifications, treatments or reactions, to create a high-performance material with previously impossible properties. In this paper we review systems that combine the well-established wood modification procedures with secondary techniques or modifications to deliver emerging technologies with multi-functionality. The new applications targeted using this additional functionality are diverse and range from increased electrical conductivity, creation of sensors or responsive materials, improvement of wellbeing in the built environment, and enhanced fire and flame protection. We identified two parallel and connected themes: (1) the functionalisation of modified timber and (2) the modification of timber to provide (multi)-functionality. A wide range of nanotechnology concepts have been harnessed by this new generation of wood modifications and wood treatments. As this field is rapidly expanding, we also include within the review trends from current research in order to gauge the state of the art, and likely direction of travel of the industry.

Chemical improvement of surfaces. Part 3: Covalent modification of Scots pine sapwood with substituted benzoates providing resistance to Aureobasidium pullulans staining fungi

Holzforschung ◽  
2015 ◽  
Vol 69 (5) ◽  
pp. 595-601 ◽  
Author(s):  
Jan C. Namyslo ◽  
Dieter E. Kaufmann ◽  
Carsten Mai ◽  
Holger Militz
Keyword(s):  
Scots Pine ◽  
Aureobasidium Pullulans ◽  
Covalent Modification ◽  
Attenuated Total Reflection ◽  
Chemically Modified ◽  
Covalently Bonded ◽  
Blue Stain ◽  
Natural Wood ◽  
The Individual ◽  
Modified Wood

Abstract The development of appropriate chemical precursors that can covalently functionalize natural wood aims at efficient restriction of deterioration. Biological staining experiments were performed with veneer pieces made of sapwood of Scots pine (Pinus sylvestris L.) that had previously been chemically modified with substituted benzoates. Based on the recently published protocol on esterification of wood by means of 1H-benzotriazole activation, the quantity of covalently bonded organomaterials (QCOs), a recently defined advantageous value considering the individual molecular weight of the functionalizing organochemical groups, was obtained in the range of 0.9–1.5 mmol g-1. The modified wood was analyzed by attenuated total reflection IR spectroscopy. Modification with three electronically different benzoates clearly reduced the colonization of the specimen’s surfaces by the blue stain fungus Aureobasidium pullulans but did not fully prevent it. The degree of colonization appeared to decrease with increasing QCO values of the modification agents but apparently did not strongly depend on the additional functionality of the benzoate.

Effect of Rolling Parameters on the Properties of Al-Fe-V Sheet Rolled on an Experimental Mill

1985 ◽  
Vol 58 ◽  
Author(s):  
A. Brown ◽  
D. Raybould
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Aluminum Alloys ◽  
Room Temperature ◽  
Thermomechanical Processing ◽  
High Temperature Strength ◽  
Rapidly Solidified ◽  
Large Sheet ◽  
Room Temperature Strength

ABSTRACTIn recent years, interest in high temperature aluminum alloys has increased. However, nearly all the data available is for simple extrusions. This paper looks at the properties of sheet made from a rapidly solidified Al-10Fe-2.5V-2Si alloy. The sheet is made by direct forging followed by hot rolling, this is readily scalable, so allowing the production of large sheet. The room temperature strength and fracture toughness of the sheet are comparable to those of 2014-T6. The high temperature strength, specific stiffness and corrosion resistance are excellent. Recently, improved thermomechanical processing and new alloys have allowed higher strengths and fracture toughness values to be obtained.

Wood modification with N-methylol and N-methyl compounds: a case study on how non-fixated chemicals in modified wood may affect the classification of their durability

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lukas Emmerich ◽  
Christian Brischke ◽  
Holger Militz
Keyword(s):  
Chemical Modification ◽  
Cold Water ◽  
Fungal Decay ◽  
Water Leaching ◽  
Chemically Modified ◽  
New Treatment ◽  
Decay Tests ◽  
Modified Wood

Abstract Chemical modification is increasing the durability of wood against biological deterioration. Usually, the effect of a new treatment on the durability of wood is screened in laboratory decay tests, where durability classes are assigned on the basis of the mass loss (ML) caused by degrading fungi. The aim of this study was to demonstrate how non-fixated chemicals in modified wood may affect fungal ML measurements and corresponding durability classification when wood samples are incubated under humid conditions for long periods. Wood blocks were treated with solutions of 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU), methylated DMDHEU (mDMDHEU) and 1,3-dimethyl-4,5-dihydroxyethyleneurea (DMeDHEU) and subjected to consecutive cold-water leaching cycles. Significant amounts of non-fixated chemicals were removed from the wood by three leaching cycles and might lead to ML mistaken as response of fungal decay. Consequently, the treated material was assigned erroneously by up to four durability classes (DC) worse than material which did not include leachable, non-fixated chemicals. Thus, for a reliable durability classification of chemically modified wood, prolonged leaching procedures are recommended to assure that the measured ML is entirely attributed to fungal decay.

Computer System for Identification of Material Models on the Basis of Plastometric Tests

2013 ◽  
Vol 58 (3) ◽  
pp. 737-743 ◽  
Author(s):  
L. Rauch ◽  
L. Sztangret ◽  
M. Pietrzyk
Keyword(s):  
Computer System ◽  
Inverse Analysis ◽  
Thermomechanical Processing ◽  
The Other ◽  
Metallic Materials ◽  
The Finite Element Method ◽  
Material Models ◽  
Basic Principles ◽  
Hybrid Computer ◽  
Further Development

Abstract The paper describes the hybrid computer system dedicated to identification of models of materials subjected to thermomechanical processing. The functionalities of the system consist of plastometric tests data processing and application of the inverse analysis. The latter functionality is realized unconventionally, instead of the finite element method the metamodel is implemented using artificial neural network. The metamodels, used for simulations of the plastometric tests, are imported to the proposed computer system as external plugins, what guarantees flexibility and possibility of further development. On the other hand, application of rich optimization libraries assures the best possible solution of the problem. Basic principles of the inverse analysis with metamodels and mentioned optimization procedures are described in the paper. Selected examples of identification of models for various metallic materials recapitulate the paper.

scholarly journals A Low-Expansion Superalloy for Gas-Turbine Applications

1985 ◽  
Author(s):  
D. F. Smith ◽  
D. J. Tillack ◽  
J. P. McGrath
Keyword(s):  
Gas Turbines ◽  
Thermomechanical Processing ◽  
High Strength ◽  
Good Resistance ◽  
Iron Cobalt ◽  
Nickel Iron ◽  
Low Thermal Expansion ◽  
Incoloy Alloy ◽  
Iron Cobalt Alloys ◽  
Further Development

A high-strength, low-expansion alloy can greatly increase the efficiency of gas turbines by permitting decreased clearances between rotating and stationary parts. This paper describes development work on a series of nickel-iron-cobalt alloys having the desired combination of high strength and low thermal expansion. The first attempts to develop alloys of this type resulted in materials that required extensive thermomechanical processing and were susceptible to the phenomenon of stress-accelerated grain-boundary oxygen embrittlement (SAGBO). Further development resulted in INCOLOY alloy 909, the first low-expansion superalloy combining good resistance to SAGBO with high mechanical properties achieved without restrictive thermomechanical processing. Those substantial improvements were brought about by the addition of 0.3% to 0.6% silicon to a low-aluminum, 38% nickel, 13% cobalt, 1.5% titanium, 4.7% niobium (columbium), balance iron composition.

scholarly journals Condition of production and operation of railway sleepers from various materials

2018 ◽  
Vol 7 (4) ◽  
pp. 157-166 ◽  
Author(s):  
Татьяна Курьянова ◽  
Tatyana Kuryanova ◽  
Алексей Платонов ◽  
Aleksey Platonov ◽  
Марина Михеевская ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Physical And Mechanical Properties ◽  
Railway Track ◽  
Natural Wood ◽  
Coniferous Wood ◽  
And Performance ◽  
Whole Life Cycle ◽  
Production And Operation ◽  
Modified Wood

Sleepers are elements of the upper structure of the railway track. When choosing a material for the manufacture of sleepers, we are based on such basic factors as cost for the whole life cycle and performance characteristics. In connection with the depletion of wood stocks in the world and the short life of wooden sleepers, the process of using sleepers made of reinforced concrete, metal and plastic goes intensively. The service life of pine sleepers is no more than 12-15 years, reinforced concrete sleepers are about 30-50 years old, plastic ones are up to 40 years old, and metal ones are 50-60 years old. However, wooden sleepers differ in the least cost, they practically do not have restrictions on the laying areas, and in some cases have a clear advantage over other materials. Reinforced concrete, metal and plastic sleepers are more expensive than wooden ones, have a longer payback period and are recommended to be laid on roads with high freight intensity, where they can pay off as quickly as possible. It is possible to reduce the shortcomings of sleepers made of natural wood, using modified hardwood for their manufacture, which, by pressing, will be stronger than the sleepers made of natural wood, which, in its physical and mechanical properties, is not inferior to sleepers made of natural coniferous wood. However, a certain disadvantage of the modified wood is its ability to change size and shape with increasing humidity. Stabilization of sizes and forms of modified wood can be increased by impregnating it with the composition of antiseptic with stabilizer. The predicted service life of sleepers from modified wood can be significantly higher than that of wooden sleepers made of natural coniferous wood.

Chemical modification of ovatodiolide revealed a promising amino-prodrug with improved pharmacokinetic profile

2020 ◽  
Vol 56 (75) ◽  
pp. 11018-11021
Author(s):  
Junhong Xiang ◽  
Xuemei Zhang ◽  
Dehong Wang ◽  
Jiaxin Li ◽  
Qiuying Li ◽  
...  
Keyword(s):  
Chemical Modification ◽  
Pharmacokinetic Profile ◽  
Promising Candidate ◽  
Further Development

Stepwise modification of ovatodiolide revealed a prodrug NMP-diepoxyovatodiolide, which is a very promising candidate for further development of liver-related drugs.

Radiation-Chemical Modification of PVDF Films as a Method of Creating Proton-Conducting Membranes

2016 ◽  
Vol 683 ◽  
pp. 193-198 ◽  
Author(s):  
Valentina Sokhoreva ◽  
Natalya A. Dubrova ◽  
Akbota Dyussembekova
Keyword(s):  
Ir Spectroscopy ◽  
Chemical Modification ◽  
Radiation Source ◽  
Gravimetric Analysis ◽  
Radiation Chemical ◽  
Proton Conducting ◽  
Conductive Membranes ◽  
Conducting Membranes

In this work we represent the results for the development of proton conductive membranes by radiochemical modification of thin PVDF films with their subsequent sulfonation. Radiation source were 4He ions with energy of 27 MeV produced by cyclotron R-7M the FTI TPU. The results of IR-spectroscopy, gravimetric analysis and microscopy are represented to evaluate changes in membranes properties. It was shown that the deepness of modificated gel can be controlled by radiation.

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