Biological, Mechanical, and Thermal Properties of Compressed-Wood Polymer Composite (CWPC) Pretreated with Boric Acid

Compressed-wood polymer composite (CWPC) was prepared by in situ polymerization of vinyl monomers, styrene (ST), methylmethacrylate (MMA), and their combination (50:50, v/v) under hot-compression of treated sapwood of Japanese cedar (Cryptomeria japonica D. Don.) to a dry set of 50 and 70% of original radial dimension. Boric acid (BA) was impregnated into wood at 1.00% aqueous solution concentration prior to monomer treatment. CWPC with and without BA-pretreatment was tested in terms of biological resistance and mechanical and thermal properties.Boric acid pretreatment imparted CWPC total resistance against decay test fungi Tyromycespalustris and Coriolus versicolor, representing brown- and white-rot fungi, respectively. CWPC showed remarkable resistance against Formosan subterranean termite Coptotermes formosanus, and BA-pretreatment contributed to a total inactivation of termite activity. Surface hardness of CWPC was superior to wood polymer composite (WPC) obtained at the same polymerization temperature and time by a conventional heat process in an oven without compression. Modulus of elasticity and rupture were also considerably improved with this newly introduced in situ polymerization process, suggesting the great potential of CWPC for exterior use. Thermal analysis revealed a reducing effect of boron on heat release of CWPC during combustion

Mechanical and radiation attenuation properties of conventional and heavy concrete with diverse aggregate and water/cement ratios

Ovim istraživanjem predstavljaju se rezultati sveobuhvatnog laboratorijskog rada kojemu je cilj ispitati mehanička svojstva i svojstva smanjenja zračenja teških betona u kojima se kao agregat koristio pirit, krom i magnetit te betona normalne težine koji su se proizveli s tri različita vodocementna omjera (v/c = 0,4/0,5/0,6). U laboratoriju su provedena ispitivanja tlačne čvrstoće, brzine prolaska ultrazvuka, eksperimentalni modul elastičnosti te koeficijenta prigušenja mase tih betona. Na temelju provedenih ispitivanja utvrđeno je da betoni normalne težine i teški betoni imaju slično ponašanje u smislu tlačne čvrstoće i modula elastičnosti. U slučaju teških betona (njihovi v/c omjeri povećani su uslijed konstantne količine vode te smanjene količine cementa), gustoća se povećava zbog povećanja količine agregata veće gustoće u odnosu na cement u sastavu betona. To je razlog zašto teški betoni koji su proizvedeni s većim v/c omjerom te koji su manje čvrstoće mogu apsorbirati više rendgenskih zraka. Koeficijenti prigušenja mase konvergiraju pri visokim energetskim razinama kod teških i normalnih betona različitih gustoća.This paper presents the results of comprehensive laboratory work conducted for investigating the mechanical and radiation attenuation characteristics of heavyweight concrete produced with pyrite, chromium, and magnetite aggregates and normal weight concretes produced with three different water/ cement (w/c) ratios. Various experiments were conducted to determine the compressive strengths, ultrasound transmission velocities, experimental elasticity modules, and mass attenuation coefficients of these concretes. Heavy and normal weight concretes exhibited similar behaviour in terms of compressive strength and elasticity modules. In heavyweight concretes, with increased w/c ratios (by keeping the amount of water constant and decreasing the amount of cement), the corresponding density increased due to the increase in the amount of high-density aggregates rather than cement in the composition of concrete. Thus, heavyweight concretes produced with a high w/c ratio and low strength can absorb more X-rays. Mass attenuation coefficients converge in heavy and normal weight concretes with different densities at high energy levels

Problems encountered in conventional HIV 1/2 Algorithms: lack of necessity for immunoblot assays to confirm repeated ELISA reactive results

Background: The use of conventional (serologically based) HIV 1/2 diagnostic algorithms has become controversial in recent years.Objectives: Sera from patients who underwent verification tests were evaluated because repeated ELISA-reactive results demonstrated a HIV1+HIV2 positive band pattern.Methods: The line immunoassay (LIA) test was used for repeated HIV enzyme immunoassays (EIA)-reactive sera in patients at three centers. The Bio-Rad Geenius™ HIV 1/2 and the HIV-1 RNA tests were used. HIV-1 and RNA HIV-2 were investigated using PCR.Results: LIA was used to evaluate 3,224 out of 10,591 samples with repeated ELISA reactivity (30%). We found that 32 (1%) of the sera, along with HIV1 bands and HIV2 gp36 bands, were positive. Only 28 of the 32 verified serum samples with gp36 bands were repeated, and no gp36 band positivity was detected using the Bio-Rad Geenius™ HIV-1/2 confirmatory assay in these serum samples. The HIV-2 proviral DNAs were also negative. Therefore, we excluded the possibility of HIV1+2 co-infection. All samples from the 32 patients were positive for HIV-1 RNA.Conclusion: Our findings highlight the need to exclude confirmatory tests like the LIA test from the current diagnostic HIV algorithm and replace it with rapid HIV-1 and HIV-2 confirmatory immunochromotographic tests.Keywords: HIV, AIDS, HIV-2

Problems encountered in conventional HIV 1/2 Algorithms: lack of necessity for immunoblot assays to confirm repeated ELISA reactive results

Background: The use of conventional (serologically based) HIV 1/2 diagnostic algorithms has become controversial in recent years. Objectives: Sera from patients who underwent verification tests were evaluated because repeated ELISA-reactive results demonstrated a HIV1+HIV2 positive band pattern. Methods: The line immunoassay (LIA) test was used for repeated HIV enzyme immunoassays (EIA)-reactive sera in patients at three centers. The Bio-Rad Geenius\u2122 HIV 1/2 and the HIV-1 RNA tests were used. HIV-1 and RNA HIV-2 were investigated using PCR. Results: LIA was used to evaluate 3,224 out of 10,591 samples with repeated ELISA reactivity (30%). We found that 32 (1%) of the sera, along with HIV1 bands and HIV2 gp36 bands, were positive. Only 28 of the 32 verified serum samples with gp36 bands were repeated, and no gp36 band positivity was detected using the Bio-Rad Geenius\u2122 HIV-1/2 confirmatory assay in these serum samples. The HIV-2 proviral DNAs were also negative. Therefore, we excluded the possibility of HIV1+2 co-infection. All samples from the 32 patients were positive for HIV-1 RNA. Conclusion: Our findings highlight the need to exclude confirmatory tests like the LIA test from the current diagnostic HIV algorithm and replace it with rapid HIV-1 and HIV-2 confirmatory immunochromotographic tests

A study on shrimp trawl designs and modifications in

This study investigates modifications and the net design of shrimp trawls in addition to their development process in Iskenderun Bay. Small sizes of traditional bottom trawl nets have been used for shrimp fishery since trawl fishery started in the region. Recently, cutting shape trawl imported from Arabic countries has been introduced by local trawl fisherman. However, they can neither manufacture the same design nor mend the nets. Finally they formed a different model trawl by trial and error method. These net plans designated as traditional net, cutting net shape net and combined net are given here according to the FAO standards, and their modifications and desings are compared. Although these nets have different design characteristics, two of them, namely traditional and combined nets are similar in their two seems and asymmetrical gear design feature. The third one namely the cutting net has four seems in wing

A STUDY ON SHRIMP TRAWL DESIGNS AND MODIFICATIONS IN ISKENDERUN BAY (TURKEY)

This study investigates modifications and the net design of shrimp trawls in addition to their development process in Iskenderun Bay. Small sizes of traditional bottom trawl nets have been used for shrimp fishery since trawl fishery started in the region. Recently, cutting shape trawl imported from Arabic countries has been introduced by local trawl fisherman. However, they can neither manufacture the same design nor mend the nets. Finally they formed a different model trawl by trial and error method. These net plans designated as traditional net, cutting net shape net and combined net are given here according to the FAO standards, and their modifications and desings are compared. Although these nets have different design characteristics, two of them, namely traditional and combined nets are similar in their two seems and asymmetrical gear design feature. The third one namely the cutting net has four seems in wingsThis study investigates modifications and the net design of shrimp trawls in addition to their development process in Iskenderun Bay. Small sizes of traditional bottom trawl nets have been used for shrimp fishery since trawl fishery started in the region. Recently, cutting shape trawl imported from Arabic countries has been introduced by local trawl fisherman. However, they can neither manufacture the same design nor mend the nets. Finally they formed a different model trawl by trial and error method. These net plans designated as traditional net, cutting net shape net and combined net are given here according to the FAO standards, and their modifications and desings are compared. Although these nets have different design characteristics, two of them, namely traditional and combined nets are similar in their two seems and asymmetrical gear design feature. The third one namely the cutting net has four seems in wing

Farklı İklim Özelliklerine Sahip Fotovoltaik Panel ve Enerji Depolama Entegreli Elektrikli Araç Şarj İstasyonlarının Teknik, Ekonomik ve Çevresel Optimizasyonu

Dünya’da artan nüfus, teknolojinin hızla gelişimi ve modern yaşam şeklinin toplumu daha fazla tüketime yönlendirmesi enerjiye olan talebi artırmaktadır. Talep edilen enerjinin yaygın olarak konvansiyonel kaynaklardan karşılanması küresel ısınma başta olmak üzere birçok çevresel ve ekonomik problem oluşturmaktadır. Dahası enerji tüketim araçlarının verimliliklerinin düşük olması ve daha çok konvansiyonel kaynaklara bağımlılığı bu durumu daha da kötüleştirmektedir. Dolayısı ile özellikle fosil kaynaklı enerji tüketiminin yaklaşık %20’sine sahip içten yanmalı araçların elektrikli hale getirilmesi ve bunların enerji taleplerinin yenilenebilir enerji kaynakları (YEK) ile karşılanması çok önemlidir. Bu çalışmada elektrikli araç (EA) şarj istasyonlarının solar fotovoltaik panel (FV) ve enerji depolama sistemleri (EDS) ile entegrasyon potansiyeli araştırılmış ve teknik, ekonomik ve çevresel etkileri optimize edilmiştir. Ek olarak önerilen modelin farklı iklimsel özelliklere sahip coğrafi bölgelerdeki etkileri yapılan hassasiyet analizleri ile tespit edilmiştir. Sonuçlar birim enerji maliyetlerinin iklimsel farklılıklara bağlı olarak %21’e kadar artış gösterdiğini ve en iyi sonucun 0,046 $/kWh ile İzmir ilinde elde edildiğini göstermiştir. Kullanılamayan yenilenebilir enerji oranını azaltmak ve temiz enerji tüketimini artırmak amacıyla kullanılan EDS’ler, solar radyasyon potansiyeli düşük olan şehirlerde amortisman sürecinin proje ömrüne yaklaşmasına sebep olmuştur. Diğer taraftan FV’li hibrit modellerde amortisman süreci 7,88 yıla kadar düşmüştür. Sonuçlar FV-EDS entegreli EA şarj istasyonlarının bulundukları bölge iklim özelliklerine bağlı olarak farklı teknik, ekonomik ve çevresel etkilere sahip olabileceğini göstermiştir. Bu durumlar dikkate alınarak altyapı ve yatırımcı teşvik mekanizmalarının geliştirilmesi gerekmektedir

Effect of Boron Addition to Adhesive and/or Surface Coating on Fire-Retardant Properties of Particleboard

Boron added to urea formaldehyde (UF) resin during manufacture of board from waste tea leaves was combined with a fire-retardant coating system containing boron to further reduce combustibility. Boric acid (BA) and borax (BX) were used as boron compounds separately or in a mixture of 5:1 (BA:BX, w/w) in aqueous solutions of UF resin. A BA+BX mixture was also added to a 40% aqueous solution of trimethylolmelamine (TMM) (as a binding agent) and applied to the board surface. Fire-retardant properties were determined according to the Japanese Industrial Standard JIS A 1322.Thickness swelling and water absorption levels were not changed remarkably by boron addition to UF resin, while static bending and internal bond strengths were reduced to some extent. However, BX addition suppressed the adverse effect of BA on board strength, probably by buffering its acidic pH to almost neutral levels, while BA reduced the glowing or smoldering effect of BX. Panels with or without added boron showed no ignition after the flame source was cut off after 13 min. Surface coating with the boron-added TMM improved fire retardance. To limit the reduction of strength properties due to boron addition to the resin, fire-retardant surface coating can be applied to impart a required level of fire protection

Effect of Thermal Ageing on the Gloss and the Adhesion Strength of the Wood Varnish Layers

WOS: 000315386400032The present study investigated the effect of thermal ageing of several wood varnishes on film characteristics. For this purpose, alkyd, two-part polyurethane (urethane-alkyd), and water-borne (self-cross-linked polyurethane) varnishes were applied on Scots pine (Pinus sylvestris L.), Eastern beech (Fagus orientalis L.), and sessile oak (Quercus petraea L.). The test samples had 8% or 12% moisture content. The samples were then thermally aged for 25, 50, 75, and 100 days at 25, 50, 75, and 100 degrees C. The decrease in adhesion strength of the varnish layers and the loss in surface gloss were determined in accordance with the ISO 4624 and ISO 2813 standards. The results of the study indicated that thermal ageing caused a decrease in the adhesion strength and gloss values.Gazi University Research FundGazi University [07/2005-04]The present study is financially supported by the Gazi University Research Fund (Grant. No. 07/2005-04) and dedicated to a dear brother, Dr. Zafer Demirci, who passed away in 2008 due to a terminal illness

FIRE RESISTANCE OF DOUGLAS FIR [Pseudotsuga menziesii (Mirb.) Franco] WOOD TREATED WITH SOME CHEMICALS

Combustible properties of treated douglas wood specimens and fire-retardancy of some preservatives were tested in this study. Crib test of ASTM E 160-150 was followed. Results indicated that, aqueous solutions of boric acid (BA), borax (Bx) (Na2BO7 10H2O) or BA + Bx mixture (7: 3, w: w) had fire retardant efficacy (FRE) over untreated wood and reduced the combustibility of vinil monomers (Styrene and methylmetacrylate) which were applied as secondary treatment