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Öğe A methodological approach to epsilon-caprolactone modification of wood(Taylor and Francis, 2022) Ermeydan, Mahmut Ali; Cambazoglu, Merve; Dizman Tomak, EylemDue to increasing environmental awareness, in recent years the research on classical wood preservation by hazardous impregnation chemicals has been shifted to more environmentally friendly chemical modification methods with organic molecules/polymers. The chemical modification processes rely on the replacement or blockage of wood hydroxyl groups with generally hydrophobic molecules, thereby improving the dimensional stability, water repellency and biological resistance of the wood. This study investigates in situ polymerization of epsilon-caprolactone to form poly(epsilon-caprolactone) (PCL), a biodegradable polymer, which was grafted to the wood cell walls of both Scots pine (Pinus sylvestris L.) and spruce wood (Picea orientalis L.). Wood modification by in situ polymerization of epsilon-caprolactone has been studied so far in order to be an alternative modification approach to obtain improved wood properties, such as good dimensional stability and improved water resistance without reducing mechanical properties considerably. In the light of previous studies, the current work proposes a methodological approach to epsilon-caprolactone modification in two aspects: (i) the effect of catalyst (tin(II) 2-ethylhexanoate) amount on wood properties (i.e., swelling (S), anti-swelling efficiency (ASE), water uptake (WU), mass loss (ML)) (ii) the effect of oven or solvent curing of epsilon-caprolactone on wood properties (i.e., S, ASE, WU, ML, compressive strength parallel to the grain, and chemical components). By these approaches, an optimum catalyst amount was determined, and an alternative method (oven-curing) which may be more economic by enabling the re-use of the waste chemical was evaluated in comparison to the method of epsilon-caprolactone modification in prior publications (solvent-curing).Öğe Use of Enzyme and Ultrasonic Energy in Paper Recycling(Karabük Üniversitesi, 2012) Karademir, ArifPaper has undeniable key roles in establishing civilization, archiving and transferring knowledge. Paper is in all parts of daily life for different purposes today and its consumption is getting at unbelievable level. For solving the problems related to insufficient raw materials, the sustainable recycling technologies should be developed rather than concentrating on sustainable forestry practices. In this sense, extracting all materials from waste papers with economical and environmentally friendly methods are extremely important. In this study, some results obtained from an experimental study carried out on the deinking of toner printed office papers with the help of enzymes and ultrasonic energy were discussed and paper industry was examined in respect to recycling and environment.Öğe Fire-retardant bioproducts for green buildings(WOODHEAD PUBLICATION, 2020) Yıldırım, Nadir; Erdönmez, Fatma Saime; Özen, Ertan; Avci, Erkan; Yeniocak, Mehmet; Acar, Mehmet; Dalkilic, Berk; Ergun, Mehmet EminFire-retardant bioproducts for green buildingsÖğe EVALUATING DESIGN OF MORTISE AND TENON FURNITURE JOINTS UNDER BENDING LOADS BY LOWER TOLERANCE LIMITS(SOC WOOD SCI TECHNOL, 2021) Uysal, Mesut; Haviarova, EvaThis study aimed to estimate the design value for mortise and tenon joints. In this respect, the design value for static load tests was determined using lower tolerance limit methods. A lower tolerance limit value at 0.99/0.99 confidence/proportional level was chosen as a design value (199.05 N.m) to secure higher joint reliability in a furniture frame. A side frame of a simple wooden chair was theoretically analyzed to obtain internal forces acting on joints, whereas the load of 1000 N was applied in the vertical direction on the top of the front leg. A full-frame chair with mortise and tenon joints was then designed using the calculated lower tolerance limit design value. This action ensured that joints would not be overstressed when a chair is under static load while not exceeding 2000 N. By applying this method, all chairs should survive static load up to 2000 N. While performing cyclic front-to-back load test, all tested chairs met the American Library Association requirements for light-duty service load, specified for household chairs. This study demonstrates that a joint failure could be prevented under expected loads specified by the standard if the joint design value is known.Öğe Poly(ε-caprolactone) grafting into Scots pine wood: improvement on the dimensional stability, weathering and decay resistance(Springer Science and Business Media B.V., 2021) Ermeydan, Mahmut Ali; Babacan, Mert; Tomak, Eylem DizmanWood modification treatments by substitution or blocking of wood hydroxyl groups with hydrophobic molecules are some of the novel approaches that may improve dimensional stability, weathering and decay resistance of wood. In this study, the Scots pine (Pinus sylvestris L.) wood was modified by ring opening polymerization of ε-caprolactone to investigate the artificial weathering and decay resistance. In total, 672 h of artificial weathering was applied on modified wood by exposure of UV-light and water cycles. Additionally, decay test was carried out by using Coniophora puteana and Trametes versicolor fungi on the samples after leaching procedure. After weathering, the color change and contact angle measurements, as well as macroscopic observations revealed that the modified wood had significantly better surface properties than reference wood. FT-IR and SEM analysis proved that there was still polycaprolactone on the weathered surface with some minor crack formations of wood structure. The polycaprolactone modification effectively protected wood against decay even after leaching. This study also demonstrates that the polycaprolactone modification can provide a significant improvement on dimensional stability, as well as water repellence of Scot pine wood. Graphic abstract: [Figure not available: see fulltext.]Öğe Instant determination of the artemisinin from various Artemisia annua L. extracts by LC-ESI-MS/MS and their in-silico modelling and in vitro antiviral activity studies against SARS-CoV-2(John Wiley and Sons Ltd, 2021) Dogan, Kubra; Erol, Ebru; Didem Orhan, Muge; Degirmenci, Zehra; Yaşa, BelkısIntroduction: Numerous efforts in natural product drug development are reported for the treatment of Coronavirus. Based on the literature, among these natural plants Artemisia annua L. shows some promise for the treatment of SARS-CoV-2. Objective: The main objective of our study was to determine artemisinin content by liquid chromatography electrospray ionisation tandem mass spectrometry (LC-ESI-MS/MS), to investigate the in vitro biological activity of artemisinin from the A. annua plants grown in Turkey with various extracted methods, to elaborate in silico activity against SARS-CoV-2 using molecular modelling. Methodology: Twenty-one different extractions were applied. Direct and sequential extractions studies were compared with ultrasonic assisted maceration, Soxhlet, and ultra-rapid determined artemisinin active molecules by LC-ESI-MS/MS methods. The inhibition of spike protein and main protease (3CL) enzyme activity of SARS-CoV-2 virus was assessed by time resolved fluorescence energy transfer (TR-FRET) assay. Results: Artemisinin content in the range 0.062–0.066%. Artemisinin showed significant inhibition of 3CL protease activity but not Spike/ACE-2 binding. The 50% effective concentration (EC50) of artemisinin against SARS-CoV-2 Spike pseudovirus was found greater than 50 μM (EC45) in HEK293T cell line whereas the cell viability was 94% of the control (P < 0.01). The immunosuppressive effects of artemisinin on TNF-α production on both pseudovirus and lipopolysaccharide (LPS)-induced THP-1 cells were found significant in a dose dependent manner. Conclusion: Further studies of these extracts for COVID-19 treatment will shed light to seek alternative treatment options. Moreover, these natural extracts can be used as an additional treatment option with medicines, as well as prophylactic use can be very beneficial for patientsÖğe Examining parameters of surface quality performance of paulownia wood materials modified by thermal compression technique(2021) Candan Z.; Gönültaş, Oktay; Gorgun H.V.; Unsal O.The aim of this study was to evaluate the effect of thermal compression process on some surface properties of paulownia solid wood materials. The widest surface of wood samples was mechanically compressed at high temperatures. The duration was 45 min. Four different process combinations were created, including two temperatures (150 °C and 170 °C) and two pressure levels (20 bar and 22.5 bar). The surface roughness, wettability and color properties of treated and untreated samples were compared. The roughness properties, both parallel and perpendicular to grain direction, were determined according to JIS B 0601:1994 standard. The contact angle changes of water dripped to the surface were measured according to time. For color properties, a spectrophotometer was used according to CIE L*a*b* system. The color changes were classified according to a grading method from literature. The most remarkable results on wettability were observed. The contact angle values significantly increased with this method. Although higher temperature increased the contact angle values, higher pressures did not change the values. When the surface roughness values were generally considered, this technique could decrease the values up to 40 % ratio according to the control group. Only the combination of 150 °C and 20 bar did not significantly change the values. Lastly, the results of color properties showed that all treatment parameters significantly affected total color change values of samples. Grading results were similar and the color change of modified samples graded as the lowest color difference, except with the combination of 150 °C and 20 bar. The combination of 170 °C and 22.5 bar (highest treatment conditions) significantly changed all color characteristics of samples, except b* parameter. The results of this research showed that mechanical thermal compression method could change surface properties of this fast-growing speciesÖğe EFFECTS OF MICROCRYSTALLINE CELLULOSE ON SOME PERFORMANCE PROPERTIES OF CHITOSAN AEROGELS(Universidad del Bio-Bio, 2021) Ozen E.; Yıldırım, NadirThe aim of this research was to investigate the effect of the microcrystalline cellulose reinforcement on some physical, mechanical, thermal, and morphological properties of the chitosan aerogels. The bio-based chitosan aerogels were produced using chitosan as a matrix and the microcrystalline cellulose as a reinforce material through the freeze-drying method. The aerogel suspensions were prepared in five different ratios to investigate the effect of microcrystalline cellulose content. The density, porosity, thermogravimetric analysis, and compressive resistance tests were conducted according to relevant standards. Morphological properties were investigated using a scanning electron microscope. The introduction of microcrystalline cellulose significantly improved the compressive resistance, thermal properties (Tonset and T%50) of the chitosan aerogels. The optimum performance properties determined as 0,12 MPa for compressive resistance, 0,27 MPa for compressive modulus, 292,45 °C for Tonset and 365 °C for T%50. According to scanning electron microscope images, aerogels showed microporous structure as expected. As a result, the bio-based chitosan aerogels reinforced with microcrystalline cellulose were successfully manufactured. The mechanical and thermal properties including compressive resistance, compressive modulus, Tonset and T%50 of chitosanmicrocrystalline cellulose aerogels found promising.Öğe Determination of Antimicrobial and Antioxidant Activities and Chemical Components of Volatile Oils of Atropa belladonna L. Growing in Turkey(Har Krishan Bhalla and Sons, 2021) Öz M.; Fidan, Muhammed Said; Baltaci C.; Ücüncü O.; Karatas S.M.In this study; the essential oils were obtained from the flowers and leaves of Atropa belladonna L. plants through the hydrodistillation method in a Clevenger type device. The chemical composition of volatile oils was determined by analyzing with the GC-MS/MS instrument. The antioxidant activity of the obtained volatile oils was determined according to total antioxidant content (TAC), free radical scavenging (ABTS) capacity, free radical scavenging (DPPH) amounts, total flavonoid content (TFC), total phenolic content (TPC), and ferric reducing antioxidant power (FRAP) capacity methods. Antimicrobial activities of essential oils were determined through the agar-disc diffusion method. As for the results; volatile oil yields of the A. belladonna were determined as 0.37 % in leaves and 1.57 % in flowers. The highest percentage of chemical compounds in essential oils of the A. belladonna plant were determined as (43.75 %) aldehydes in leaves and as (39.96 %) fatty acids in flowers. In addition, the main constituents found in volatile oils were eicosane (35.92 %) in the leaves and hexadecenoic acid (18.84 %) in the flowers of the A. belladonna. The highest amounts of antioxidant for the test specimens were found as 1.37-1.48 mg QE/100 mL in TFC, as 13.25-21.91 mg AA/100 mL in ABTS, as 51.49-62.87 mg GA/100 mL in TPC, and as 4.71-7.97 mg FeSO4/100 mL in FRAP capacity. As the results of the antimicrobial activities, it was determined that only the leaves of A. belladonna show antimicrobial activity against the mold-yeast and gram-positive and gram-negative bacteria microorganisms among the 17 bacteria and 6 yeast-mold types used in the study.Öğe Chemical performance analysis of nanocellulose/boron-compound-reinforced hybrid UF resin(ICE Publishing, 2021) Yildirim M.; Candan Z.; Gönültaş, OktayUrea-formaldehyde (UF) resin is the most important used adhesive in the production of wood-based composite panels, such as particleboard, medium-density fiberboard, oriented strand board and plywood. The aim of this work was to investigate the influence of nanocellulose, boric acid and borax on the chemical performance properties of UF resin. UF resin was reinforced with various loading levels of nanocellulose, boric acid and borax. Formaldehyde emission, gel time, solid content, viscosity, pH, specific gravity, shelf life and Fourier transform infrared spectra were evaluated as indicators of chemical performance. The findings showed that the formaldehyde emission of hybrid UF resin reinforced with nanocellulose/boron compounds decreased by up to 31.25%. The use of the reinforcement technique in the resin caused an increase in shelf life, viscosity and gel time but caused a reduction in the solid content of the resin. The apparent specific gravity of the resin was not influenced by the addition of nanocellulose/boron compounds. It was concluded that the chemical performance properties of UF resin could be enhanced by using proper nanocellulose, boric acid and borax loading levels. By using the reinforcement technique, it was possible to produce low-formaldehyde-emitting adhesives so that environmentally friendly products could be manufactured.Öğe Characterization of weathered MCC / nutshell reinforced composites(Elsevier Ltd, 2021) Boran Torun S.; Dizman Tomak, Eylem; Donmez Cavdar A.; Mengeloglu F.Microcrystalline cellulose (MCC) and nutshell fiber reinforced high-density polyethylene (HDPE) composites were exposed to accelerated weathering for total of 672 h. The effects of weathering exposure on the mechanical, surface and morphological properties of the composites were investigated. The results revealed that the weathering exposure caused a slight decrease on tensile and flexural strengths whilst the modulus of elasticity increased up to 62%. The MCC / nutshell reinforced composites had higher color changes and gloss loss than MCC reinforced composites. Addition of MCC and nutshell to HDPE composites increased surface roughness of samples. After the weathering, the polymer band intensities decreased due to the degradation. The SEM observations on the exposed composites are in accordance with the surface roughness of composites after weathering. The investigated properties of MCC/nutshell filled HDPE composites were less affected by weathering exposure than those of composites without nutshell.Öğe The effect of green biobased binder on structural, mechanical, liquid absorption and wetting properties of coated papers(Elsevier Ltd, 2021) Altay B.N.; Klass C.; Chen T.; Fleck A.; Aydemir C.; Karademir, Arif; Fleming P.D.Synthetic styrene-butadiene (SB) and styrene-acrylic (SA) latex binders used in paper coating formulations are common and based on unsustainable petroleum sources. Today's papermaking industry turns towards sustainable substitutes that do not compromise quality, and reduce carbon emission, toxic substance release and waste disposal concerns related to fossil fuel sources. In this study, colloidal starch-based latex nanoparticles that do not require cooking were used for pigment coating and coated on the paper surfaces. The effects of these new biobased binders on the structural and mechanical strength properties, liquid absorption, wetting and surface topography of the paper were investigated and compared with the properties of coated paper that SB latex was used as a coating binder. The results demonstrated that the biobased latex decreases the grammage of paper while maintaining an identical thickness relative to the SB latex samples. The porosity, permeability and roughness of biobased latex are found higher than the SB latex. The biobased latex successfully replaced SB latex at 1:1 ratio and enabled an equivalent of bursting, tear, tensile strength and structural properties.Öğe Life cycle assessment (LCA) of nanocellulose composite panels (NCPs) manufactured using freeze-drying technique(2018) Yıldırım, NadirThe life cycle assessment (LCA) is a powerful technique to investigate the environmental impacts of current and new products and production processes. In this research, the LCA of nanocellulose composite panels (NCPs) produced using freeze-drying techniques were studied. The environmental effects of the final product and the production method were reported. The nanocellulose is a bio-based raw material that can be obtained from a variety of natural sources and used in building, construction, packaging, pharmaceutical, and insulation industry. The wood-based cellulose nanofibrils (CNF) produced using mechanical grinding, and the industrial corn-starch (Ethylex 2025) were used as raw materials in this study. The n-Dodecenyl Succinic Anhydride (DDSA) and boric acid (BA - ((B(OH)3 )- 99.94 % pure) were used as treatment materials. As a result of this explanatory research, the cellulose nanofibrils (CNFs) produced using mechanical process were found environmentally friendly as expected. The production process, freeze-drying technique, was not found eco-friendly in laboratory scale. However, using solar energy in full-scale production can decrease the energy consumption up to 76% and would make the process eco-friendlier. The nanocellulose composite panels (NCPs) can be produced using the freeze-drying technique. The findings of this study showed that freeze-drying technique would be feasible and nature-friendly in full-scale production using renewable energy sources.Öğe Mürekkep Giderme İşleminin Farklı Atık Kâğıtlar Üzerindeki Etkisi(2019) Karahan, Selim; Karademir, ArifBu çalışmada, ofis (A4), kuşe, oluklu mukavva, NSSC (Nötral sülfit yarı kimyasal hamur), gazete ve karışım kâğıtları üzerine hamurlaştırma işlemleri yapılmıştır. Bu işlemin sonunda ise dövme ve ardından mürekkep giderme işlemi yapılmıştır. İşlem sonunda ise elde edilen test kâğıtlarına ise bazı testler yapılmıştır. Çalışmada, kontrol amaçlı standart yüzdürme metoduna göre mürekkep giderme işlemi yapılmıştır. Bu amaçla, sodyum hidroksit, hidrojen peroksit, sodyum silikat, oleik asit ve kalsiyum klorür ingede metoduna göre uyarlanarak kullanılmıştır.Öğe Doğu ladini (Picea orientalis) ve meşe (Quercus spp.) kabuklarının kimyasal bileşimi(2017) Gönültaş, Oktay; Uçar, Mualla BalabanBu çalışmada, orman işletmelerinde kesim sonrası ortaya çıkan doğu ladini (Picea orientalis) kabukları ve ahşap levha endüstrisinde levha üretimi sonrası ortaya çıkan endüstriyel atık meşe (Qercus spp.) kabuklarının kimyasal bileşimi temel odun analizleri ve fenolik bileşik analiz metotlarıyla incelenmiştir. Kabuklarda kül tayini sonuçlarına göre Artvin ve Trabzon ladin örneklerinde % 4.31 ve % 3.99 kül bulunurken meşe kabuğunda % 10.02 gibi yüksek sonuç belirlenmiştir. Sıcak su çözünürlüğünün ladin örneklerinde meşeye göre daha yüksek olduğu ortaya konulmuştur. Artvin ladin, Trabzon ladin ve meşe kabuklarında kalıntı lignin sırasıyla % 19.53; % 20.61 ve % 18.49 olarak belirlenirken ?-selüloz miktarı için % 37.28; % 37.92 ve % 41.59 değerleri elde edilmiştir. Toplam fenol tayini ve butanol HCl yöntemi sonuçlarına göre Artvin ladin kabuğu en yüksek değerlere sahiptir. Ladin ve meşe kabuğu örneklerinde hidrolize tanenler olan gallo tanen bulunurken ellag taneni içeriği belirlenememiştirÖğe Kağıt üretiminde CaCO3 dolgu maddesinin kimyasal tutunması üzerine bir araştırma(2013) Karademir, Arif; Varlıbaş, Hülya; Çiçekler, MustafaHammadde sıkıntısının ileri boyutlarda yaşandığı kağıt/karton endüstrisinde, çok çeşitli dolgu maddeleri farklı oranlarda kağıt ve karton üretiminde, selüloz lif kullanımını azaltma yanında çok çeşitli fonksiyonlar için tercih edilmektedir. Hamur süspansiyonuna ıslak partide katılan bir dolgu maddesinin, elek üzerinde yüksek oranda kalması, kağıt/karton içerisinde homojen dağılması ve liflere iyi tutunması arzu edilir. Bu araştırmanın birinci aşamasında, uzun polimer ve inorganik bir polielektrolitin, eski kağıt işleyen bir kağıt fabrikasının atık suyunu arıtma seviyeleri incelenmiştir. İkinci aşamada ise bu kimyasalların dolgu tutunmasına katkısı tek tek ve beraber araştırılmıştır. %60/40 oranında harman yapılmış ağartılmış uzun ve kısa elyaf kağıt hamurları kademeli olarak 45 shopper (ºSR) değerine gelene kadar işlenmiştir. Diğer taraftan dolgu olarak kalsiyum karbonat seyreltik olarak saf su içerisinde homojen bir şekilde dağıtılmış ve farklı oranlarında katılım gerçekleştirilerek çok sayıda el kağıtları üretilmiştir. Üretilen kağıtlara ilk aşamada hiçbir kimyasal katılmadan, özellikle dolgu tutunmaları ve kağıtların bazı özellikleri takip edilmiştir. Tutunma seviyesi hassas olan %30 dolgu içeren el kağıtları, devam eden aşamalarında, sırasıyla katyonik uzun polimer ve yeni geliştirilmiş olan kısa bir inorganik polielektrolitin farklı oranlarda ayrı ayrı ve beraber katılımları ile üretilmiştir. Polimerlerin tek katıldığı gruplarda tutunmanın azaldığı birlikte kullanıldığı grupta tutunmanın en iyi sonucu verdiği gözlenmiştir. Sonuçlar, kağıt kalitesi ve çevre açısından tartışılmıştır.Öğe Kâğıt Fabrikası Arıtım Suyu Çamurunun Diğer Atık Kâğıtlarla Birlikte Ambalaj Kartonu Üretiminde Değerlendirilmesi(2020) Karahan, Selim; Karademir, ArifGünümüz sanayinin hızlı bir şekilde gelişme göstermesi, beraberinde su kirliliğini de getirmektedir. Özellikle günümüzde doğanın rastgele sanayi atık suları ile kirletilmesi canlı ve cansız her şeyi de etkilemektedir. Bu sorunun çözümü için suyu yoğun bir şekilde kullanan endüstriyel tesisler atık suyu arıtma tesislerinde arıttıktan sonra doğaya vermektedir. Kâğıt fabrikaları da suyu yoğun olarak kullanan endüstrilerin başında gelmektedir. Bu gibi tesislerde suyun arıtılması sonucunda atık çamur oluşmaktadır. Bu çamur geri yıkama suyu ile birlikte doğaya bırakılmaktadır. Burada âtıl durumda bulunan çamuru değerlendirerek ülke ekonomisine bir katkı sağlanması düşünülmektedir. Hem bu sayede atık çamurda tekrar geri dönüşüme girerek hem insanlar hem de doğa için faydalı bir duruma dönüşmüş olacaktır. Bu araştırmada atık kâğıt işleyen Kahramanmaraş Kâğıt Fabrikasından (KMK) üretim sonrası elde edilen atık çamur kullanılmıştır. Bu çamur içerisine çeşitli işlemlerden sonra kil, kalsiyum karbonat, nişasta, reçine vs eklenip malzeme üretilmiştir. Daha sonra bu malzemelere press uygulanmıştır. Daha sonra ise bu malzemelerin kurutulması sağlanmıştır. En sonunda ise bütün üretilen malzemeler için laboratuvar testleri yapılmıştır. Atık kâğıt karışımına belirlenen oranlarda katılan atık çamur ile yapılan testler sonucunda; kopma indis değeri ve patlama indis değerinde %5’ lik atık çamur katılımında max. değere ulaşmıştır. Diğer taraftan cobb ve hava geçirgenliği değerlerinde ise bir azalış meydana getirir iken kül değerinde ise bir artış meydana gelmiştir.Öğe Chemical Modification of Spruce Wood with Combination of Mesyl Chloride and Poly (?-caprolactone) for Improvement of Dimensional Stability and Water Absorption Properties(2016) Ermeydan, Mahmut AliMalzemelerin üretiminde önemli bir konu olan sürdürülebilirlik, ahşap gibi yenilenebilir kaynaklardan elde edilen malzemeler kullanılarak sağlanabilir. Ahşap mükemmel mekanik özelliklere sahip doğal bir malzemedir. Ancak, ortamdaki nem değişimleri ahşabın boyutsal kararlılığını olumsuz etkiler. Hem su iticilik hem de boyutsal kararlılık ahşap hücre çeperi içine hidrofobik moleküller sokulmasıyla arttırılabilir. Bu çalışmada, iki aşamalı bir modifikasyonla önceden mesil klorür ile hidrofobize edilmiş ahşap hücre çeperleri içine biyolojik olarak bozunabilir bir polimer olan poli(?-kaprolakton) (PCL) aşı polimerizasyonuyla bağlandı. Konfokal Raman görüntüleme ve spektroskopisi tekniğiyle ahşap hücre çeperleri içindeki mesil grupları ve poli(?-kaprolakton) dağılımını gösterildi. Modifiye edilmiş ahşap hücre çeperlerinin morfolojisi taramalı elektron mikroskobu ile gözlemlendi. Fiziksel testler sonucunda poli(? kaprolakton) ile aşılanmış ahşabın referanslara göre önemli ölçüde daha iyi boyutsal kararlılığa ve su iticiliğe sahip olduğu gözlendiÖğe Physical and mechanical properties of wood impregnated with quebracho and boron compounds(2019) Fidan, Muhammed Said; Adanur, HakanIn recent years, alternative natural impregnation materials are being sought as substitutes for chemical impregnation materials used for conserving wooden materials; therefore, such natural materials have acquired significance in the forest products industry. In this study, the boron compounds borax and boric acid, which are abundant raw materials in Turkey, and quebracho, a natural impregnation material, were used. For the impregnation process, aqueous solutions of 1%, 3%, and 5% boron compounds were utilized. The test samples were impregnated according to ASTM D 1413-76 principles. Oven-dry density, retention rate, bending strength, elastic modulus, compression strength parallel to fibers, bonding strength parallel to fibers, and screw holding strength tests of the impregnated samples were measured, and the results were compared with those of control samples. The retention, oven-dry density, comprehension parallel to fibers, and screw holding strength of the samples were found to be higher than those of the control samples, whereas bending strength, elastic modulus, and bonding strength parallel to fibers were lower. After impregnation, it was observed that there was a decline in strength values and a rise in retention rates with the increase in the concentrations of boron compounds. The values for samples impregnated with borax were higher than those for the samples impregnated with boric acid.Öğe Lazer Baskılı Ofis Kâğıtları Üzerinde Yapılan Mürekkep Giderme İşleminin Süzüntü Suyu Üzerine Etkileri(2020) Karahan, Selim; Karademir, ArifÇalışmada, önce lazer baskı uygulanmış beyaz A4 ofis kâğıtları üzerinde hamurlaştırma işlemleri uygulanmıştır. Daha sonra ise hamurlaştırılan ofis kâğıtları üzerinde belirlenmiş oranlarda karışımlar hazırlanmıştır. Bu hamurlaştırma ve karışım hazırlama sürecinde ise farklı yüzde oranlarda kimyasal ve enzimden faydalanılmıştır. Kimyasal madde olarak oleik asit, sodyum hidroksit, sodyum silikat, kalsiyum klorür ve hidrojen peroksit kullanılmış ve enzim olarak ise selülaz, ksilanaz, amilaz ve ?-gluktonaz kullanılmıştır. Çalışmada daha sonra ultrases etkisine bakılmıştır. En sonunda ise hamur süspansiyonu yüzdürme yöntemi ile mürekkeplerinden uzaklaştırılması yapılmıştır. Tüm bu işlemler sonunda ise atık su analizleri yapılmıştır.
