Sorts Of Wood Research Articles

Features of ignition and combustion of low-grade coal mixed with pyrolysis liquid

THE RELEVANCE of the study lies in the need to use pyrolysis liquid from wood processing for combustion in boilers of medium and low power as part of mixtures with coal. The unpredictability of the ignition and combustion properties of such mixtures, as well as the lack of calculation methods, predetermined a predominantly experimental approach to the study of these processes. At the same time, for the widespread implementation of such technological solutions in practice, it is necessary to have relatively simple methods for assessing the ignition and combustion characteristics of these components. THE PURPOSE. Synthesize samples of pyrolysis liquid from two different sorts of wood and perform their characterization. Develop an experimental method for studying ignition and combustion characteristics of pyrolysis liquid mixed with low-reactivity coal. Perform research on ignition delay times and the composition of released gas-phase products. Determine the main mechanisms of action of the components in the mixture of low-grade coal with pyrolysis liquid they’re during ignition and combustion. METHODS. The study was carried out using an experimental technique based on a high-temperature muffle furnace equipped with a high-speed video camera and a once-through gas analyzer. RESULTS. The article presents the dependences of the ignition delay times and the concentration curves of gas-phase products released during combustion of mixtures of low-grade coal and two types of pyrolysis liquid in the temperature range of the heating medium 600-800 °C and additive concentrations from 0 to 20 wt.%. Linear approximation dependences of ignition delay times on additive concentrations were obtained, and the mechanism of action of the additive during combustion was formulated. CONCLUSION. It was found that an increase in the concentration of the additive in the mixture leads to a stable decrease in the ignition delay times, while the amount of gas-phase products formed varied additively with respect to the composition of the mixture. The shape of the concentration curves for the release of CO and NOx indicates the independent action of the components of the mixture. The mechanism of action of additives was proposed. It was based on significant contribution of their evaporation process followed by combustion in the gas phase, which, in turn, initiats the ignition of coal.

Wooden Constructions in Bronze and Iron Age Burials in Japan and Korea

Throughout the period from 300 BC to 700 AD, significant changes took place in the life of population of Japanese Archipelago and Korean Peninsula, which were reflected by the burial rite. Specifically, the practice of using wood in mounded burials became particularly common. Such numerous instances in both regions are analyzed, the placement and several elements of wooden structures, accompanying artifacts, sorts of wood etc. are described in this work. The changes in burial rite practiced in ancient Japan can be seen. During the Yayoi period (300 BC to 300 AD), jar burials gave way to those with wooden structures in Western Japan regions closest to the mainland. It’s established that traditions co-occurred with innovations, as seen from the fact that such structures were coated with clay. Further development took place during the Kofun period (300–538 AD), when first log coffins appeared, then composite coffins, and eventually stone coffins. Similar burial practice existed in Korea earlier than in Japan, the peak of this tradition coinciding with the period of Three Kingdoms (200–600 AD). The comparison of the ways the tradition evolved in both regions suggests that it had originated on the mainland, was introduced to Japan by successive immigration waves, and was then adapted to local conditions.

Notes for calculated resistance to tension for laminated wood

Wood as a material with sharply expressed anisotropic properties fully transfers them to glued wood. Depending on the force vector under tension along, across and at an angle to the fibers, it differ tenfold. The results of studies of laminated wood tensile at different angles to the orientation of the fibers are given. The results of calculations are determined with testing of standard samples fordesign strength according to the method of ALTI–CNIISK. It is established that the angle between fiber orientation and vector of the applied force αis influenced a lot bythe tensile strength and depends on the sort of wood. The value of tensile strength is decreased when the angle vary from 0 to 90°. Experimental values are compared with theoretical results which are given in current standards –Rules and Norms 64.13330.2017 “Wooden structures”. The difference between theoretical and standard results is 4 … 70%. More accurate approximating expressions of experiments are presented, which can be used in practice instead of formula (6) from Rules and Norms.

GİRESUN’DA GELENEKSEL ÜÇ AHŞAP KÖPRÜ

Three wooden bridges which have unknown years of built and one of them was collapsed a few years ago are situated in some subcentral villages in Giresun are presented and evaluated in this study. Two wooden bridges (Han Bridge and Ezirkan Bridge), which one of them was destroyed a few years ago, are on Batlama Creek that draw a line between subcentral Hisargeris Sayca and Hisargeris-Uzkara villages in Giresun and also another bridge (Ahmed Aga Bridge) on Lapa (Great) Creek within the borders of subcentral Lapa village in Giresun are analysed in this study. The bridges that form a part of traditional rural architecture preserve their original appearances on a large scale. There are unfortunately very few examples have been remained in our country because this kind of bridges does not fulfill new requirements, they are abandoned and destroyed soon after new bridges are erected. These buildings merely have been subjected to the academical analyses and published and some of them are on the brink of destruction because they have not been registered. These building that being surveyed shows rural construction features of Black Sea Region characteristically. The bridges have hipped roofs on wooden columns and stone pillars carrying beams and girder. We suppose that the roofs were covered with tiles originally. At present they are covered with galvanized sheets (spelter). The buildings that functionally prominent are devoid of ornamentation. These buildings represent the similar tradition with their materials, technical qualities, architectural expressions. There is not an inscription or documentation about years of built of the bridges. But considering the similar traditional styles and the similar wooden bridges in Trabzon, Cankiri, Kastamonu, it is thought that these bridges were built between 19th and early 20th centuries. However, all of them looks as if they were built at a latter date with their present situations based upon restorations and partial renovations. The sorts of wood used for the bridges are oak and chestnut which are common locally. The oak and chestnut trees are known as long lived, very solid and adaptable with the rainy climate in the region. Because of that, they are suitable for the construction of bridges. It is helpful that recognition of the little known wooden bridges in terms of traditional construction style. We hope that this study will make a contribution to the protection of wooden bridges.

A comparative analysis of pine and beech wood classification according to Polish and EU norms

Investigations were carried out at timber storage sites (depots) on large-sized pine (110 pieces) and beech (130 pieces) wood from three forest districts within the territory of the Regional Directorates of the State Forests (RDSF) of Łodź, Lublin and Krakow. As a result of a comparison of both classification systems, it was proved that in the case of pine wood classified according to EU norms, the shares of the number of pieces and volume in classes B and C decreased, whereas they increased in class D when compared with Polish classification. Analogically, in the case of beech wood, a decrease in the share of the number of pieces and volume in classes A, B and D, and an increase in class C were recorded. Among the most common defects that influence the classification of both sorts of wood, open and burl knots as well as curvatures are recognised, while in the case of beech wood, shakes and galls (disease T stains) are encountered. The results of the classification determined differences in the wood value. According to the pricelists for wood standing in forest districts where the raw wood under investigation originated, it was established that the value of the pine wood classified according to the EU norm decreased by ca. 7.6% when compared with the value estimated using the Polish norm. The value of the beech wood was nearly identical in both cases, which was mainly due to the higher share of wood of class C and lower share of class D upon applying the EU standards, in comparison with the Polish classification system.

Introduction and contents of Forest Regulation (1857)

The article sheds light on the circumstances predominantly causing that Forest Regulation (1857) be introduced, the very procedure of its introduction, puts forward the contents of that act and systematizes its articles. Not very long after the introduction of the Regulation on Deforestation (1839), the public expressed discontent with the effects it had caused. From the mid-forties ever more criticism emerges towards that rule, demanding its abolition and replacement with another regulation which would protect forests in a better manner. In the beginning of fifties the voices that Serbia was being mercilessly deforested provoke the first drafts of new regulation. In 1855, State Council proposes the prince the outline of Forest Regulation consisting of 27 articles and containing provisions on the sorts of wood whose cutting is permitted, the procedure of issuing tree-cutting permit, taxes for downed trees depending on the purposes of their use and sort of wood, penalty provisions and attribution of lands covered by forests to the poor. Nevertheless, in 1856 the prince declined his sanction and requested the Council to reconsider its draft. Due to the request, the Council decided to confide reproduction of the outline to the Commission antecedently formed in order to examine state income and expenditure and draw up a tax reform. The Commission completed its task in February 1857, sending the Council altered version of prime draft, in some places significantly differing from the original. However, the Council failed to adopt the majority of Commission's remarks. Instead, it withdrew some of original provisions and replaced it to its own new resolutions. Such text was sent to the prince on May 18th,1857. The ruler expressed his approval and requested the Council to resend him the draft in the appropriate form of regulation. The Council had granted the recommendation and the draft, now in requested form, was sent anew to the prince, who eventually, on June 26th approved the introduction of the Forest Regulation. Withal, some loopholes were noticed afterwards, so the Council decided to unify three authentic interpretations issued on the initiative of Ministries of Finances and Internal Affairs into a single act - supplement to the Regulation. Future research on this field should focus on the reactions that the Regulation caused among the public, its comparison to the Regulation on Deforestation and further elaborate the social context that preceded the Regulation's enactment. Only after having deepened actual knowledge on the Regulation with answers to aforementioned questions, will the Regulation be wholly scientifically examined.

Procedencia y uso de madera de pino silvestre y pino laricio en edificios históricos de Castilla y Andalucía

Se realiza un recorrido a través del ciclo constructivo de las maderas de pino silvestre (Pinus sylvestris L.) y pino laricio (Pinus nigra Arn.) en el ámbito de la carpintería medieval de Castilla y Andalucía. Nuevos criterios para diferenciar las dos especies de madera y su datación dendrocronológica, son aportados como datos previos para determinar el origen geográfico del material. Son objeto de discusión los nombres históricos de estas especies y otras voces, como alerce, que tienen una imprecisa asignación. Se identifican así las principales áreas históricas de aprovechamiento y las vías fluviales del Tajo y Guadalquivir utilizadas para el abastecimiento de madera de pino laricio a poblaciones del interior peninsular (Sevilla, Toledo, Madrid, etc.). Por otra parte, se analizan la diversificación de maderas y su uso selectivo en función del valor resistente de cada especie. Así mismo, las condiciones de disponibilidad determinan que un tipo de madera se convierta en fósilguía (especie-guía), que se propone como indicador cronológico de varios periodos y contextos constructivos. Finalmente, se estudian más en detalle restos lígneos del primer milenio de la Era, pertenecientes a la Mezquita de Córdoba y cuatro iglesias altomedievales de la cuenca del Duero (La Nave, Baños, Quintanilla y Barriosuso). La datación empírica y el análisis de este material aportan una cronología post quem de la construcción de estos edificios y también nuevos datos sobre la distribución de estas especies en la región norte de la Península Ibérica.

Composite of wood and polymerized methacrylate

A composite material consisting of woody skeleton and polymerized methacrylate has been developed and characterized. Main aim of this paper is to study the physical properties of such a composite, and in particular, the strength, hardness, sorptive ability, etc. all as a function of methacrylate content. The experimental test was carried out mainly on pine sapwood and heartwood , however, other sorts of wood were also tested in some experiments. One can state that due to polymerization of wood one obtains a composite with risen endurance, increased strength, reduced water sorptivity , and improved many other physical properties.

Some wood polymer composites ii

AbstractSeveral samples of casuarina and other sorts of wood were impregnated in methyl methacrylate (MMA) or its mixture with some other specific multifunctional monomers, such as ethylene glycol dimethacrylate (EGDMA), triethylene glycol dimethacrylate (TEGDMA), trimethylol propane trimethacrylate (TMPTMA) and tetrahydrofurfuryl methacrylate (THFMA). The monomer or mixture of monomers in the treated samples was polymerized either by being subjected to γ‐radiation from a60Co‐γ‐cell or by using 0.1 wt.‐% of benzoyl peroxide, or by employing both methods.The use of swelling agents was found to influence the gained monomer, polymer and the physical properties of the treated products, though the specific multifunctional monomer role has not yet clearly been identified, due to the variation in uniformity of distribution of wood constituents from one test piece to the other. 30kJ/kg were found to be the optimal dose for the highest compression strength. With 2000 and a 500 curie‐60Co sources, we found the same effect, and came to the conclusion that the dose rate was not important in the used ranges.

III. Observations upon the Vessels in several sorts of wood, and upon muscular fibres of different animals. By the same curious and inquisitive person

Seeing some reddish boards carry'd into a house in my neighbourhood, and enquiring what use they were design'd for, I was answer'd that they were bought of the India Company to make Cabinets of, and that they came from the Island Amboina .

An account of an engine that consumes smoak, shown lately at St. Germans fair in Paris

To burn all sorts of wood in the middle of a room without making any smoak, is a thing so extraordinary, that all those that have heard speak of it, as well Philosophers as others, have asserted it impossible