Effects of Glycol on Leachability and Efficacy of Boron Wood Preservatives

Although boron has many advantages as a wood preservative, this chemical performs poorly in leaching exposures. In this study, we investigated the potential for decreasing the leachability of boron preservatives with polyethylene glycol (PEG). Southern pine (Pinus spp.) test samples impregnated with combinations of sodium borate or boric acid and PEG were subjected to both leaching and decay tests. Samples treated sequentially with sodium borate or boric acid and then with PEG-400 or PEG-600 showed a significantly increased resistance to boron leaching. However, decay tests indicated that blocks treated with sodium borate or boric acid and PEG experienced slightly higher weight losses at nearly all retention levels, possibly as a result of PEG depletion. Thus, although the results suggest that bulking agents may enhance the resistance of boron to leaching, the enhanced leach resistance may be a temporary effect

Land-use effect on distributions of as, cr and cu in soils adjacent to cca-treated utility poles in Artvin and Rize, Turkey

Chromated copper arsenate (CCA)-treated wood has been widely used in Turkey to protect it from decay. In this study, influences of land-use types on distributions of As, Cr and Cu in soils adjacent to CCA-treated utility poles were studied in tea and hazelnut plantations as well as crop fields. Ten poles from each land-use type (a total of 30 poles) were chosen for the study purposes in Arhavi and Fındıklı towns of Artvin and Rize, Turkey, respectively. Soil samples were collected from surface layers of soil (0- 10 cm depth), adjacent to the utility poles and at distances of 0.5 m and 10 m (control). Concentrations as high as 80, 520 and 94 mg kg-1 were observed in soils adjacent to utility poles for As, Cr and Cu, respectively. Soil As, Cr and Cu levels decreased significantly with the distance from the CCA-treated poles. Cr concentrations in soil were sig- nificantly higher in the tea plantations than in the crop fields (P <0.05). Soil pH, sand, clay and organic matter content varied significantly with land-use type. Our results indicate that the use of CCA-treated utility poles in the tea planta- tions poses more environmental contamination risks com- pared to that in hazelnut plantations and crop fields. These risks could be eliminated by using alternative arsenic-free wood preservatives

Optimal Controller Design for Speed Governors of Hydroelectric Power Plant

Speed governors have critical importance on hydroelectric power plants, which are adjusted to the rotating speed of hydroelectric generation based on load demand of the grid. The rotating speed is the main factor to balance power generation and load demand. The well-designed controller is needed to control speed governors with high accuracy. A well-defined model is needed to obtain desired control structure. Therefore, in this study, initially, the mathematical model of a hydroelectric power plant is obtained by using physical characteristics of a real-world. Then by using this model and corresponding real-world data, a set of controller parameters is designed by using tuning methodologies based on heuristic optimization algorithms, and their performances are compared with each other and with a classical tuning methodology. Evolutionary-based and nature-inspired-based heuristic optimization algorithms are selected as the tuning algorithms not only to compare the performance of these algorithms with a classical method but also with different origins. The performance of the optimized controller improves the performance of the overall system and helps to get desired performance. The results also indicate that as long as the desired performance criteria are defined as accurate as possible, the performance of the optimization algorithms is acceptable

Impregnatıon of wood composıtes

Son yıllarda kullanımında hızlı artışlar gözlenen odun kompozitlerinin kullanım yerlerine bağlı olarak (yonga ve lif levha, tabakalı ve lamine ağaç malzemeler vb.) odun tahripçisi organizmalara karşı koruyucu kimyasal maddelerle emprenye edilmesi gerekmektedir. Bu çalışmada; odun kompozitlerine koruyucu maddelerin nasıl ilave edileceğinin incelenmesi, bu emprenye maddelerin tutkallamaya olan etkisinin araştırılması ve koruyucu kimyasal maddeler ile muamele edilen odun kompozitlerinin üretiminde en iyi yöntemin belirlenmesi amaçlanmıştır.The production of wood based structural panel and lumber composites become to increase since the wood supply is changing due to the limit of larger dimension solid sawn lumber and insufficient solid woods with enough high strength as well. As we substitute wood composites for solid wood in protected application, these composite must show resistance to wood-destroying organisms such as fungi and insects. Accordingly, the exterior structural composites is required to be treated with preservatives. This paper provides an understanding of preservative treated wood composites. The objectives of this paper includes studying how to add preservative to wood composites, examining additive effect on glue-line and evaluating the best method of manufacturing wood composites treated with preservatives

Removal copper, chromıum, arsenıc from out-of- servıce cca-treated wood materıals

Remidasyon, atıl haldeki CCA ile emprenyeli ağaç malzemelerden bakır, krom ve arseniği uzaklaştırmak amacıyla uygulanan işlemler olarak tanımlanabilir. Atıl haldeki emprenyeli ağaç malzemelerin tekrar kullanılması veya bakır, krom ve arseniğin çevreye ve diğer canlılara verdiği zararları önlemek veya en aza indirmek amacıyla birbirinden farklı birkaç remidasyon yöntemi söz konusudur. Bu çalışma kapsamında bugüne kadar uygulanan remidasyon yöntemleri ve bu konularda yapılan çalışmalar hakkında bilgiler verilmiştir.Remediation can be defined as removing copper, chromium and arsenic from out-of-service CCA treated wood products. There are some various remediation methods that can be applied to remove copper, chromium and arsenic from out-of service CCA treated wood products in order to re-use that wooden materials and minimize adverse impacts of those out-of service CCA treated wood to environment, human health, animals and other living organisms. In this study, those applied various remediation methods to remove copper, chromium and arsenic were summarized

Decay mechanısms ın copper-tolerant fungı

Bakır içeren CCA, CCB ve AZCA gibi emprenye maddeleri mantar ve böceklere karşı etkili olmalarından dolayı uzun yıllardır kullanılmaktadır. Yapılan çalışmalarda, CCA ile emprenyeli tel direklerinin, arsenik içermesine rağmen, bakıra toleranslı mantarların izole edildiği belirtilmiştir. Poria türü mantarlarının bakıra karşı direnç mekanizmasını, bu mantarların suda çözünebilen bakır sülfatı suda çözünmeyen ve mantarlara karşı daha az zehirli olan bakır oksalatlara dönüştürmeleri şeklinde açıklamıştır. Özellikle toprakla temas halinde olan ve çürüklük riskinin yüksek olduğu bölgelerde yıkanma oranının yüksek olması nedeniyle, kullanılan ağaç malzemelerin emprenyesinde bu hususlar göz önüne alınmalı ve emprenye formülasyonuna ek fungisitlerin ilavesi düşünülebilir.opper-based wood preservatives such as CCA, CCB, AZCA, have long been used because of their considerable efficacy. Although copper-based wood preservatives have been widely used for protecting wood against fungal attack, some brown rot and soft rot fungi, have repeatedly been isolated from copper treated wood in service, although CCA contains arsenic which is very toxic to fungi and insects. Copper tolerance in Poria species converted soluble copper sulphate into insoluble copper oxalate, which is less toxic to fungi. Especially, wood materials used in ground contact and in the regions where the decay risk of wood materials is higher result in more leaching, these factors should be taken into account and also additional fungicides might be thought to be added into preservatives formulations

Leachıng mechanısm of chromated copper arsenate (cca) wood preservatıve

Son yıllarda ağaç malzemeye olan talebin artması, buna karşın ormanların hızlıca yok edilmesi ağaç malzemenin emprenye edilerek, kullanım ömrünün artırılmasını zorunlu kılmıştır. Her ne kadar Ülkemizde ağaç malzemenin emprenyesi ile ilgili standartlara uyma mecburiyetinin olmamasına ve emprenye işlemlerinin Bayındırlık İskan Bakanlığı'nın hazırladığı şartnamelere girmemiş olmasına rağmen, yılda yaklaşık 400.000 m3 iğne yapraklı türlerden üretilen tel direkleri ve 30.000 m3 yapraklı ve iğne yapraklı türlerden üretilen traversler emprenye edilmektedir. Ülkemizde tel direklerinin emprenyesinde yaygın olarak bakır/krom/arsenik (CCA) kullanılmaktadır. TEDAŞ Trabzon Bölge Müdürlüğünün verilerine göre, sadece Trabzon ilinde 208.000 Rize ilinde 180.000 ve Artvin ilinde 121.000 adet dikili tel direği bulunmakta ve bu üç ilde ortalama her yıl CCA (bakır/krom/arsenik) ile emprenye edilmiş 17.000 adet tel direği kullanılmaktadır. Emprenyeli ağaç malzemelerde CCA'nın odundan yıkanmasına neden olan faktörlerin belirlenmesi ve yıkanma mekanizmasının aydınlatılması Doğu Karadeniz Bölgesinde kullanılan CCA ile emprenyeli tel direklerinin kullanım sürelerinin beklenilenden çok daha kısa olmasının nedenlerini ortaya koymak açısından büyük önem arz etmektedir. CCA ile emprenyeli ağaç malzemelerden bakır, krom ve arseniğin yıkanmasında emprenye yöntemi fıksayon, ortam koşulları, odun örneği veya ağaç malzeme boyutları, odun türü, ağaç malzemenin hizmette bulunma süresi, çözelti pH'sı, çözeltinin tuzluluk derecesi ve sıcaklığın etkili olduğu tespit edilmiştir.In recent years, the increase demand on wooden raw materials and destroyed forest area (i.e clear cutting) led to pressure on forest resources. Thus, Wood used in outdoor applications should be treated with preservatives to extent service life. in our country, although there is no regulations or any standards to be obeyed to preserve wood materials, averagely, 400.000 m3 /per year utility poles manufactured from softwood species and 30.000 m3 /per year rail road slippers produced from either hardwood species or softwood species have been impregnated with wood preservatives. Chromated copper arsenic (CCA) is commonly used wood preservatives to preserve utility poles in our country. According to data taken from Turkish Electricity Transmission Company (TEDAS) 208.000 utility poles are used in Trabzon city area, 180.000 utility poles are in Rize city area, 121.000 utility poles are used in Artvin. Roughly 17.000 utility poles are replaced every year in three cities. Determining leaching factors of treated wood is important for explaining the short service life of utility poles treated with CCA used in Black Sea area. Factors such as preservative formulation, fixation temperature, post-treatment handling, wood dimensions, leaching media, pH, salinity and temperature have been shown to effect leaching of CCA treated wood

Photodegratıon of wood

Ahşap malzeme yüzyıllardır çok yönlü ve yoğun bir şekilde kullanım alanına sahip olmakla birlikte diğer tüm biyolojik materyaller gibi çevresel faktörlerin etkisine açıktır. Dış ortama bırakılan işlem görmemiş doğal odun, kimyasal, mekanik ve enerji kaynaklı faktörlerinin birleşimiyle meydana gelen degredasyona maruz kalmaktadır. Bu derleme çalışmasında; dış ortamda ağaç malzemede meydana gelen makroskopik, mikroskopik, kimyasal ve fiziksel değişiklikler özetlenmiş ve fotodegredasyon olayı mekanizması ve önleme yöntemleri belirtilmiştir.Wood has been recognized for centuries throughout the world for its versatile and attractive engineering and structural properties. However, like other biological materials, wood is susceptible to environmental degradation. Deterioration of wood in natural weathering process involves very complex combination of chemical, mechanical and light energy factors contribute to what is described as weathering. In this review, the influence of outdoor weathering on the macroscopic, microscopic, chemical and physical changes was described. The mechanisms of photodegredation and protection of wood surfaces are summarized

The effect of cca on the mechanıcal propertıes of alder wood

Bu çalışmada; CCA ile (Bakır/krom/arsenik) %1, %3 ve %10 konsatrasyonlarında emprenye edilen ve değişen sıcaklıklarda (60 °C, 88 °C ve 100 °C) fiksasyona bırakılan kızılağaç odunlarının mekanik özellikleri belirlenmiştir. ASTM D 1413 standardına göre emprenye edilen odun örneklerinde liflere paralel basınç ve statik eğilme direnci TS 2474 ve TS 2595 standartlarında öngörülen şekilde belirlenmiştir. Elde edilen bulgulara göre sıcaklık ve konsantrasyon artışı ile liflere paralel basınç ve statik eğilme dirençlerinde genel bir artış söz konusu olmaktadır.In this study, it was aimed to determine mechanical properties of alder wood treated with CCA (1, 3 and 10%) and fixed at different temperatures (60 °C, 88°C and 100 °C). Compression strength parallel to grain and Modulus of Elasticity (MOE) of CCA treated (according to ASTM D 1413) and untreated (control) alder wood samples were investigated according to TS 2474 and TS 2595, respectively. Results shows that compression strength parallel to grain and modulus of elasticity of treated wood samples increased generally while concentration and fixation temperature were increasin

Interactıon of copper based preservatıves wıth wood

Bakır, mantarlara karşı sahip olduğu yüksek orandaki zehirlilik etkisinden dolayı, son 50 yıldır emprenye endüstrisinde pek çok odun koruma formülasyonlarında yaygın olarak kullanılmaktadır. Bakır içeren emprenye maddeleriyle odun arasındaki etkileşim, hem emprenye maddesinin performansı hem de bu maddelerin çevresel etkileri bakımından önemlidir. Bakır, odunda olası bakır-selüloz kompleksi, bakır-lignin kompleksi ve kristal veya amorf inorganik/organik bakır bileşikleri formlarında bulunabilir. Bu derleme çalışmasında; bakırın odunla olan etkileşimi, bakır adsorpsiyonunu etkileyen faktörler ve emprenyeli odundaki bakır formları irdelenmiştir.Copper is highly toxic to fungi and the element is widely used in many preservative formulations over 50 years. The interactions of wood and copper-based preservatives impact both the performance and the environment aspects of treated wood. Copper might be present in treated wood as coppercellulose complex, copper-lignin complex, and crystalline or amorphous inorganic/organic copper compounds. In this review; it was aimed to investigate the interactions of wood and copper-based preservatives, Copper Adsorpsion factors and copper forms in treated woo