606 research outputs found

    The color changes on varnish layers after accelerated aging through the hot and cold-check test

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    The purpose of this paper is to determine the color changes of cellulosic, polyurethane and acrylic varnish layers which were applied on the surfaces of Scots pine (Pinus sylvestris L.), Eastern beech (Fagus orientalis L.) and sessile oak (Quercus petraea L.) wood material after accelerated aging effects through the hot and cold-check test. For this purpose, test samples were firstly kept at 50 ± 5°C temperature for 1 h, and then conditioned for 1 h in a conditioning room, later moved to -20 ± 2°C temperature keeping for 1 h according to ASTM D1211-97 standard. These processes were accepted as 1 cycle and tests were continued to 20 cycles. Then the color changes were determined by using Minolta CR-231 device of tristimulus colorimeter according to ASTM D2244-07e1 standard. It was foundthat most color change was determined in cellulosic, polyurethane and acrylic varnish layers on the surfaces of Scots pine (Pinus sylvestris L.), Eastern beech (F. orientalis L.) and sessile oak (Q. petraea L.) wood material. The endurance of the protective coating (such as paint and varnish) to external effects is limited and the lifetime of the coating is determined by the type and the severity of the effects to which it is exposed. The effect of a color change on varnish layers can determine the usefulness of the varnish. It is conjectured that especially for the manufacturers and consumers in the furniture and decoration sector, the data obtained in this study will contribute to the making up of deficiencies in the understanding of the subject

    The effect of open air conditions on the properties of wooden material

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    In this study, the impregnation materials of Tanalith-C (CCA) and Protim 230 WR were used as preservative and water repellant. Wooden materials were taken from beech and black pine. The sampleswere made subject to weathering conditions for one year. At the end of this period, changes occurred in the samples’ bending strength, compression strength and physical properties were examined. As a result of this study, it was observed that no significant variations occurred in mechanical values of the impregnated samples; however, severe losses occurred in case of the non-impregnated samples. It was seen that impregnation type provides different protection according to the type of the wooden material.It was observed that discoloration is more significant in the  on-impregnated samples compared with those impregnated. Both of the impregnation materials provide sufficient protection

    Some Qualitative Properties of Solutions of Quasilinear Elliptic Equations and Applications

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    AbstractWe study quasilinear elliptic equations of Leray–Lions type in W1, p(Ω), maximum principles, nonexistence and existence of solutions, the control of lower (upper) bound for essential supremum (essential infimum) of solutions, sign-changing solutions, local and global oscillation of solutions, geometry of domain, generating singularities of solutions, and lower bounds on constants appearing in Schauder, Agmon, Douglis, and Nirenberg estimates

    Effect of the glutenin genes on quality parameters in common wheat

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    Association of glutenin alleles with bread quality has long been known and identification of glutenin alleles may be very informative for the quality of the breeder’s material. In this study, 64 wheat genotypes were evaluated for high and low molecular weight glutenin alleles (Glu-1 and Glu-3) and some quality parameters. Of the identified glutenin alleles, eleven were at the Glu-1 loci and 15 were at the Glu-3 loci. Highly significant (P<0.001) differences were found among the genotypes for all quality parameters. Associations of glutenin alleles with the quality parameters were also found significant. The positive effective glutenin alleles of Glu loci on quality traits were 1 at Glu-A1, 13+16, 17+18 and 7+8 at Glu-B1 and 5+10 at Glu-D1, and A3d, A3e, A3f and A3b at GluA3, B3a, B3b and B3g at Glu-B3 and D3a at Glu-D3. The negative effective glutenin alleles of Glu loci on quality traits were null allele at Glu-A1, 7, 7+9 and 14+15 at Glu-B1, 2+12 at Glu-D1 loci, and A3a, A3c at Glu-A3, B3f, B3c at Glu-B3 and D3c at Glu-D3

    The Conformal Points of the Generalized Thirring Model II

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    In the large N limit, conditions for the conformal invariance of the generalized Thirring model are derived, using two different approaches: the background field method and the Hamiltonian method based on an operator algebra, and the agreement between them is established. A free field representation of the relevant algebra is presented, and the structure of the stress tensor in terms of free fields (and free currents) is studied in detail.Comment: 20 pages (latex, no other macros needed). This replaces an earlier version.A typo and some sign mistakes are corrected, and a paragraph added; Full postscript available from http://thoer1.lbl.gov/www/theorgroup/papers/36926.p

    Miscellanea Balkanica I.

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    Autor teksta je, između ostalog, radio i kao kustos muzeja u Sarajevu i na Cetinju, te je zavolio sakupljanje povijesnih materijala, iako nije povjesničar po struci. Za sebe kaže da je potpuno svijestan da je taj njegov rad skroman, ali i smatra da će bili koristan, "jer će spremni stručnjaci moći iz ove sirove građe nešto dobro istesati." (sa 1 slikom

    Integrable Generalized Thirring Model

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    We derive the conditions that the coupling constants of the Generalized Thirring Model have to satisfy in order for the model to admit an infinite number of commuting classical conserved quantities. Our treatment uses the bosonized version of the model, with periodic boundary conditions imposed on the space coordinate. Some explicit examples that satisfy these conditions are discussed. We show that, with a different set of boundary conditions, there exist additional conserved quantities, and we find the Poisson Bracket algebra satisfied by them.Comment: Final version to be published in Nucl.Phys.B. Only minor changes. An equation was deleted and a conclusion revised, and a few comments were added. Harvmac, 15 pages. Full postscript available from http://theor1.lbl.gov/www/theorgroup/papers/39040.p

    String Field Equations from Generalized Sigma Model

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    We propose a new approach for deriving the string field equations from a general sigma model on the world sheet. This approach leads to an equation which combines some of the attractive features of both the renormalization group method and the covariant beta function treatment of the massless excitations. It has the advantage of being covariant under a very general set of both local and non-local transformations in the field space. We apply it to the tachyon, massless and first massive level, and show that the resulting field equations reproduce the correct spectrum of a left-right symmetric bosonic string.Comment: harvmac big, 39 pages Full postscript available from http://theor1.lbl.gov/www/theorygroup/papers/39854.p
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