Effects of impregnation with boron compounds on the surface adhesion strength of varnishes used woods

The aim of this study was to determine the effects of impregnation with boron compounds on the surface adhesion strength of varnishes used woods. For this purpose, the test specimens prepared from Oriental beech (Fagus orientalis Lipsky) and European oak (Quercus petreae (Matt.) Liebl.) which met the requirements of ASTM D 358 were impregnated according to ASTM D 1413 with boric acid (Ba) and borax (Bx) by vacuum technique. After impregnation, surfaces were coated with cellulosic, synthetic, polyurathane, water-based, acrylic and acid hardening varnishes in accordance with ASTM D 3023 standards. According to ASTM D 4541 standards, the surface adhesion strength of specimens after varnishing process was determined. Considering the interaction of wood type, impregnation material and varnish type, adhesion strength values were found the highest in Oriental beech + boric acid + synthetic varnish (6.240 Mpa) and the lowest values in European oak + borax + cellulosic varnish (2.080 Mpa). Consequently, impregnation of wood material with boron compounds (boric acid: 3.677 Mpa and borax : 3.732 Mpa) showed increasing impact on the surface adhesion strength of cellulosic, synthetic, polyurathane, water-based, acrylic and acid hardening varnishes.Key words: Adhesion strength, impregnation, boric acid, borax, varnishes, finishing, wood

The P-Hub maximal covering problem and extensions for gradual decay functions

Cataloged from PDF version of article.The p-hub maximal covering problem aims to find the best locations for hubs so as to maximize demands within a coverage distance with a predetermined number of hubs. Classically, the problem is defined in the framework of binary coverage only; an origin-destination pair is covered if the cost (time, etc.) is lower than the critical value, and not covered at all if the cost is greater than the critical value. In this paper, we extend the definition of coverage, introducing "partial coverage", which changes with distance. We present new and efficient mixed-integer programming models that are also valid for partial coverage for single and multiple allocations. We present and discuss the computational results with different data sets. (C) 2015 Elsevier Ltd. All rights reserved

New Russian policies towards Central Asia

Ankara : Institute of Economics and Social Sciences of Bilkent Univ., 1995.Thesis (Master's) -- Bilkent University, 1995.Includes bibliographical references leaves 148-152.In this analysis, it has been attempted to reflect some light into the enigmatic future of the new Russian foreign policy towards Central Asia. To this end, elucidating and discussing the changes in the nature of Russian foreign policy reflected in two phases of time towards Central Asia in terms of economic, ethnic, political, strategic, ideological and military motives has become imperative. A review of groups in the foreign policy making processes are given, and the two dominant schools of foreign policy making: the Atlanticist and Eurasianist schools are examined. The implications of the presence of 1 O million ethnic Russians living in the Central Asian states, an interdependent economic system , the peacekeeping and defense agreements , and the role of Islam in the shaping of politics in Russia towards Central Asia are analyzed with two case analyses. In order to be able to have a full picture of the future balances in Central Asia, Turkish and Iranian roles are also heeded and placed into the Central Asian picture. The final analysis is devoted to clarification of the Russian position in Central Asia, with the aim of injecting some predictability to the unknown future of a recently growing region in world politics.Peker, M GündenM.S

The P-Hub maximal covering problem and extensions for gradual decay functions

The p-hub maximal covering problem aims to find the best locations for hubs so as to maximize demands within a coverage distance with a predetermined number of hubs. Classically, the problem is defined in the framework of binary coverage only; an origin-destination pair is covered if the cost (time, etc.) is lower than the critical value, and not covered at all if the cost is greater than the critical value. In this paper, we extend the definition of coverage, introducing "partial coverage", which changes with distance. We present new and efficient mixed-integer programming models that are also valid for partial coverage for single and multiple allocations. We present and discuss the computational results with different data sets. © 2015 Elsevier Ltd

Cultivation of Agaricus bisporus on wheat straw and waste tea leaves based compost formulas using wheat chaff as activator material

This study was designed to determine the pin head formation time and yield values of Agaricus bisporus on some casing materials. Composts were prepared basically from wheat straw and waste tea leaves by using wheat chaff as activator substance. Temperatures of the compost formulas were measured during composting at various depths in order to determine the compostability level. Results showed that in both compost types, maximum temperature values were recorded in the second turning stage. Composting was completed in 21 days for both composts. While the fastest pin head formation (12.50 days) was obtained on wheat straw based compost using peat of Bolu (PB) and peat of Agacbasi (PA) (50+50; in volume); waste tea leaves based compost using peat of Caykara (PC) and forest soil (FS) mixture (50+50; in volume) as casing material gave the fastest pin head formation (13.25 days). In terms of yield, a mixture of peat of Bolu and peat of Agacbasi (PA) (50+50; in volume) gave the highest yieldfor wheat straw based compost, a mixture of peat of Agacbasi and perlite (P) (80+20; involume) had the highest yield for waste tea leaves based compost

Microscopic description of Gamow-Teller transitions in middle pf--shell nuclei by a realistic shell model calculation

GT transitions in $N=28\sim 30$ nuclei are studied in terms of a large-scale realistic shell-model calculation, by using Towner's microscopic parameters. $B({\rm GT})$ values to low-lying final states are reproduced with a reasonable accuracy. Several gross properties with respect to the GT transitions are investigated with this set of the wavefunctions and the operator. While the calculated total GT$^-$ strengths show no apparent disagreement with the measured ones, the calculated total GT$^+$ strengths are somewhat larger than those obtained from charge-exchange experiments. Concerning the Ikeda sum-rule, the proportionality of $S_{\rm GT}$ to $(N-Z)$ persists to an excellent approximation, with a quenching factor of 0.68. For the relative GT$^-$ strengths among possible isospin components, the lowest isospin component gathers greater fraction than expected by the squared CG coefficients of the isospin coupling. It turns out that these relative strengths are insensitive to the size of model space. Systematics of the summed $B({\rm GT})$ values are discussed for each isospin component.Comment: IOP-LaTeX 23 pages, to appear in J. Phys. G., 5 Postscript figures available upon reques

Cultivation of Agaricus bisporus on wheat straw and waste tea leaves based composts using poplar leaves as activator material

This study was carried out to determine pin head formation time and mushroom yield of Agaricus bisporus on some casing materials. Composts were prepared basically from wheat straw and waste tealeaves using poplar leaves as activator material. In this study, moreover, in order to follow the evolution of the composting process, daily temperature measurements were taken. According to the results of the study, in both compost types, maximum temperature values were observed in the second turning stage. While in the first and second turning stages, inner-pile temperature of the compost was in atendency of exhibiting steady increase, they are prone to decrease in the following turning stages. In both composts, the period of composting has finished in 19 days. While the fastest pin head formation(13 days) was obtained on wheat straw based compost using peat of Caykara (PC) and forest soil (FS) (50+50; in volume); waste tea leaves based compost using peat of Bolu (PB) and peat of Caykara (PC)mixture (50+50; in volume) as casing material gave the fastest pin head formation (13.30 days). While, a mixture of peat of Agacbasi (PA) and perlite (P) gave the highest yield for wheat straw based compost,peat of Bolu shows the highest yield for waste tea leaves based compost

Covering Vehicle Routing Problem: Application for Mobile Child Friendly Spaces for Refugees

Tubitak under the Grant Number 216M380