Yazarlar
- Duran, Celal(26)
- Ozdes, Duygu(21)
- Baltaci, Cemalettin(10)
- Gundogdu, Ali(10)
- Gül, Abdulkadir(9)
- Çullu, Mustafa(8)
- Aksüt, Yavuz Selim(7)
- Baltacı, Cemalettin(7)
- Barut, Abdulkadir(7)
- Bozbeyoglu, Pinar(7)
- Erol, Ismail(7)
- Ozeken, Sengul Tugba(7)
- Peker, Iskender(7)
- Eker, Hasan(6)
- Külekçi, Gökhan(6)
- Altuner, Elif Esra(5)
- Ar, Ilker Murat(5)
- Güzel, Melih(5)
- Karahan, Selim(5)
- Karpuz, Ömer(5)
- Kıranşan, Murat(5)
- Odabaş, Halil İbrahim(5)
- Seferoğlu, Mehmet Tevfik(5)
- Uysal, Turan(5)
- Demir Şahin, Demet(4)
- Imamoglu, Mustafa(4)
- Karpuz, Omer(4)
- Top, Yener(4)
- Akar, Bülent(3)
- Akpinar, Muhammet Vefa(3)
- Akpınar, Özlem(3)
- Avci, Ibrahim(3)
- Aydoğmuş, Ercan(3)
- Bozbeyoğlu, Pınar(3)
- Cakir, Mehmet Ali(3)
- Camoglu, Aslihan Yilmaz(3)
- Cavusoglu, Ibrahim(3)
- Daulay, Amru(3)
- Ercikdi, Bayram(3)
- Komut, Osman(3)
Yayınlar
- MakaleYalnız künye2019Production and Characterization of Bacterial Cellulose from Citrus Peels
Güzel, Melih; Akpınar, Özlem
Cellulose is the most common polymer in the world, formed by β-1,4 linked glucopyranose units. In this study, citrus peels (lemon, mandarin, orange and grapefruit) were used for the production of bacterial cellulose (BC). The peels were hydrolyzed with dilute acid and hydrolysates were used for BC production. The production of BC was carried out at 28–32 °C for 21 days under static conditions with Komagataeibacter hansenii GA2016. BC yields were found to be between 2.06 and 3.92%. It was found that the FTIR spectra of the BCs produced in citrus peel hydrolysates were similar to BC produced in the commercially available nutrients. The result of this study showed that all the BCs produced from citrus peels were characterized to have high water holding capacity, thin fiber diameter, high the thermal stability and high crystallinity.
- MakaleYayıncıda açık erişim2019Investigating the mechanical behavior of reclaimed asphalt pavement (RAP) bases in large scale test box
Seferoğlu, Ayşegül Güneş; Seferoğlu, Mehmet Tevfik; Akpinar, Muhammet Vefa
The objective of this research was to assess the elastic deformations and permanent strains of reclaimed asphalt pavement (RAP) material as a base layer when it is treated or untreated with pozzolanic cement under cyclic loads. A large-scale cyclic plate loading testing (CPLT) device was developed for studying the mechanical characteristics of pavement base layer. The laboratory test results indicated that when the RAP percentage of the mixtures increased, elastic deformations and permanent strains increased, but the opposite was true when the cement percentage increased. It was concluded that 100% RAP material can be used in base layers with 3% pozzolanic cement. The obtained deformation values and strain rates can be used as reasonable default design input values by pavement designers when using RAP as a substitute for natural aggregate base layers.
- MakaleYalnız künye2019Production of silicone-based composite doped with waste NdFeB magnet and determination of mechanical properties by transforming experimental results into images
Çelik, İlhan; Akben, Selahaddin Batuhan; Mazlum, Uğur
Waste neodymium–iron–boron (NdFeB)-doped silicon-based magnetic polymer composites are obtained by mixing the double-doped mixtures with a 70–30% ratio. In this study, composite materials were produced by adding NdFeB magnetic particles with sizes between 0–45, 45–63, 63–125, and over 125 (µm), and compression experiments were carried out to determine the mechanical properties of them. Experimental results were transformed into images and then analysed using image processing methods. According to the analysis of images representing the results of compression experiments, the strength values of NdFeB–RTV (vulcanized at room temperature) silicone rubber have increased by increasing the magnetic powder ratio. In addition, it was observed that there is a decrease in the elongation at break values due to weakening of polymer chain bonds. Considering the sensitivity of the successfully produced composite materials to the magnetic field, significant improvements in strength values were obtained. It is hoped that these results will lead to an increase in the recycling rate of waste magnets and will prevent environmental damage.
- MakaleYalnız künye2019Valorisation of fruit by-products: Production characterization of pectins from fruit peels
Güzel, Melih; Akpınar, Özlem
The aim of the study is to determine the physical, chemical, structural and thermal properties of the pectins obtained from melon rinds, kiwifruit and pomeganate peels and compared with the pectins obtained from apple and orange peel used in the commercial pectin production process. Pectins extractions from these wastes were performed with citric acid, at 80 °C and 60 min. All pectins, extracted, were found to be high methoxyl pectines. The water holding capacity of the melon rind, kiwifruit and pomegranate peels pectins were lower than the orange and apple peel pectins while the thermal stability of the kiwifruit peel pectin was close to the apple and orange peel pectins. The morphological structures of the extracted pectins showed that they had micro-fractures and hollow openings. The crystallinity of the melon rinds, kiwifruit and pomegranate peel pectins were smilar to orange peel pectin. The result of this study showed that the kiwifruit peel had advantages in terms of commercial pectin production due to its high pectin yield, water holding capacity, esterification degree and thermal stability.
- MakaleYalnız künye2019Exploring the value of using data: a case study of continuous improvement through data warehousing
Rogers, W. Pratt; Kahraman, M. Mustafa; Dessureault, Sean
The mining industry is adapting data-rich technology. Data management processes and infrastructure require additional investment which, can be difficult to justify. A valuation model for data management infrastructure would necessitate modelling the ‘use’ of data and quantifying the value and the likelihood of success of improvement initiatives. A model is presented which can assess the impacts of a data-driven initiative. The initiatives are shown to be the foundation of improved shift coordination resulting in significant and sustained operational improvements. This paper aims to illustrate the value of using data from source systems in mining operations.
- MakaleAçık Erişim2018Atık Barajı Rezervuarı ve Cevher Stok Alanlarında Asit Maden Drenajı (AMD) Oluşumunun Değerlendirilmesi: Gümüşhane Örneği
Akaryali, Enver; Gücer, Mehmet Ali; Alemdag, Selçuk
Doğal kaynakların kullanımı ile ilgili işlemlerin başında gelen madencilik faaliyetleri, işletmenin türüne ve büyüklüğüne bağlı olarak farklı boyutlarda gelişen çevresel etkilere ve bozulmalara neden olmaktadır. Bu etkilerin başında, madencilik faaliyetleri sırasında ve sonrasında ciddi ekolojik riskler oluşturan Asit Maden Drenajı (AMD) gelmektedir. AMD, sülfür içeren (özellikle pirit, pirotin ve kalkopirit) cevher atıkların, tipik olarak hava (oksijen) ve su içeren ortamlarda, yeraltı suyu, yağmur ve akıntı nedeniyle oksitleyici koşullara maruz kalması sonucu meydana gelen asit oluşumunu ifade etmektedir. Bu çalışmada, Gümüştaş Madenciliğe ait işletme sahası, cevher stok ve atık depolama alanlarında AMD oluşumunu belirlemeye yönelik işlemler yapılmış ve AMD gelişme potansiyeli ile muhtemel AMD gelişmesi durumunda alınacak tedbirler ortaya konmuştur. Maden işletme alanı, Eosen yaşlı andezit ve bazalt ile bu kayaçların piroklastitlerinden oluşan Alibaba Formasyonu içerisinde yer almaktadır. Yapılan çalışmalarda pH değerleri tüm örneklerin I. sınıf kıta içi kaynak suyu özelliğinde olduğunu, macun pH ve sülfid (S-2) değerleri ise maden işletme sahasında AMD potansiyelinin bulunmadığına işaret etmektedir. Ana ve iz elementlerin düşük mobiliteye sahip olması ise bu durumu destekler niteliktedir. Tüm örneklerde Net Nötralizasyon Potansiyeli (NNP) değerlerinin 20 kg CaCO3/ton’dan ve Nötralizasyon Potansiyel Oranı (NPO) değerlerinin 2’den büyük olması da potansiyel asit üretmeyen karakterde olduğunu göstermektedir. S-2 değerlerinin çok düşük olması, söz konusu alanda kısa dönem içerisinde asit kaya drenajı potansiyeli gerçekleşmeyeceğini işaret etmektedir. Buna ek olarak, stok sahasını geçirimsiz hale getirmek için 50 cm kalınlığında geçirimsiz kil serilerek sıkıştırılmış, oluşan düşey profil sonlu eleman ağ sisteminde modellenerek su deşarjları belirlenmiştir. Yapılan tüm çalışmalar neticesinde maden işletme sahasında kısa sürede AMD oluşumu beklenmediği sonucuna varılmıştır. Ancak, maden işletme alanında, uzun sürelerde muhtemel AMD oluşumundan kaynaklanacak çevre kirliliği, yapılan çalışma kapsamında alınacak tedbirlerle önlenmiş olacaktır.
- MakaleAçık Erişim2018Mavi Renklenme Zararının Tomrukların Endüstriyel İşlenme Özellikleri Üzerine Etkileri
Öztürk, Atakan; Komut, Osman
Mavi renklenme tomruk, kereste ve kullanım yerlerindeki malzemede estetik karakteristikler ve mekanik şok direncinde neden olduğudeğişimler dolayısıyla önemli ekonomik kayıplara yol açmaktadır. Diğer yandan, zarara maruz kalmış malzemede emprenye ve üstyüzey işlemlerindeki başarı oranının düşük olmasının tomruğun endüstriyel kullanım alanlarını önemli ölçüde sınırlandırdığıbilinmektedir. Bu çalışma mavi renklenme zararının, tomruk işleyen orman endüstri işletmeleri üretim süreci üzerindeki etkilerini veneden olduğu kayıpları belirlemeyi amaçlamıştır. Araştırma, Gümüşhane ilinde Sarıçam tomruğu işleyen toplam 9 küçük ve orta ölçeklikereste üretim işletmesinde gerçekleştirilmiştir. Çalışmada, mavi renklenme zararının boyutu tomruk toplam hacmine oranlanarakdeğerlendirilmiştir. Diğer yandan, inşaat ve doğrama sektörlerine yönelik üretim gerçekleştiren işletmeler arasında, mavileşmesonucu oluşan tahribat yönünden karşılaştırmalar yapılmıştır. Çalışma sonucunda, mavi renklenme tahribatında hacmen zarara maruzkalma oranının diri odun genişliği, tomruk boy ve çap değişkenlerine bağlı olmak üzere %32-84 arasında değiştiği belirlenmiştir.Ayrıca, inşaat ve doğrama sektörlerine yönelik kereste üretimi yapan işletmeler arasında tomruk enine kesit yüzeyindeki mavileşmişalan genişliği ve bozuk hacim oranı değişkenlerine göre istatistiksel düzeyde anlamlı farklılıklar bulunduğu (p<0,05) tespit edilmiştir.Diğer yandan, inşaat sektörüne yönelik üretim yapan kereste işletmelerinde mavi renklenme zararının göz ardı edildiği görülmüştür.Doğrama sektörüne yönelik üretim yapan işletmelerde ise malzemenin görsel niteliklerinin iyileştirilmesi amacıyla mavileşmiş kısmınuzaklaştırıldığı, ancak bu işlem dolayısıyla ilave enerji ve işgücü maliyetlerinin oluştuğu tespit edilmiştir.
- MakaleAçık Erişim2018Nano materyal içerikli katkıların yakıt özelliklerine ve egzoz emisyonlarına etkileri
Sezer, İsmet
Bu çalışma; dizel, biyodizel, su veya alkol içeren emülsiyon yakıtları ve çeşitli yakıt karışımları gibidizel motor yakıtlarında nano materyal içerikli katkıların kullanılmasının yakıt özellikleri, motorperformansı ve egzoz emisyonlarına etkileri üzerine yapılmış çalışmaların sonuçlarından derlenmiştir.Dizel motorlar iyi performans ve güvenilirlik karakteristiklerine sahip olmasına rağmen dizelmotorlardan yayılan egzoz gazları içinde yarı yanmış veya yanmamış hidrokarbonlar, karbondioksit,karbonmonoksit, partikül madde (is) ve azot oksitler gibi zararlı emisyonlar bulunur. Dizel motorlardazararlı egzoz emisyonlarının azaltılması için üç farklı teknik uygulanmaktadır. Zaralı emisyonlarıazaltmak için uygulanan tekniklerden ilki motor tasarımda ve yakıt püskürtme sisteminde değişiklikleryapılarak yanmanın iyileştirilmesidir. Ancak bu pahalı ve zaman alıcı bir süreçtir. Emisyonları azaltmakiçin uygulanan ikinci teknik katalitik konvertör ve partikül filtresi gibi çeşitli egzoz gazı cihazlarınınkullanılmasıdır. Ancak, bu cihazlar dizel motorların performansını olumsuz yönde etkilemektedir. Dizelmotorlarda, emisyonları azaltmak ve aynı zamanda motorun performansını artırmak için kullanılanüçüncü teknik ise çeşitli yakıt katkılarının kullanılmasıdır. Dizel motorlardan yayılan en önemlikirleticiler azot oksitler (NOx) ve partikül madde (PMis) emisyonlarıdır. Uygulamada, NOx ve PMemisyonlarını birlikte azaltmak oldukça zordur. Emisyonları azaltırken motor performansını artırmanınen iyi yolunun nano materyal içerikli katkıların ve su veya alkol ile emülsiyonlaştırılmış yakıtlarınkullanımı olduğu birçok araştırmacı tarafından bildirilmektedir. Bu derleme çalışmasında çeşitli dizelmotor yakıtlarında farklı nano materyal içerikli katkıların kullanımının yakıt özelliklerine ve egzozemisyonlarına etkileri literatüre dayalı olarak incelenmiştir. Bu şekilde, nano metaryal içerikli katkılarınetkilerinin bir arada değerlendirilmesi amaçlanmıştır.
- Derleme MakaleAçık Erişim2018Edible Film and Coating Applications in Fruits and Vegetables
Okcu, Zuhal; Yavuz, Yasemin; Kerse, Sevgi
Different preservation and packing techniques are applied to maintain quality and safety during food transportation and storage. Changing in world and increasing consumer demands led to new techniques and procedures in packing. Light, easy opening, eco-friendly, bioplastic and edible packaging materials are improved to resolve problems that occured nowadays. Edible packaging material are environment-friendly because they decompose quickly in nature even if don't consume. In addition edible films increase food's organoleptic properties and support nutritional values when used with inserted supporting member. Fruits and vegetables are high sensitive product; therefore, attention should be paid while transporting and storing and they must be packed in the right way.. Delaying ripening and reducing loss of weight in fruit and vegetable could be supplied with edible films and coatings.
- MakaleAçık Erişim2018Investigation of the Effect of Recycled Asphalt Pavement Material on Permeability and Bearing Capacity in the Base Layer
Seferoǧlu, Ayşegül Güneş; Seferoǧlu, Mehmet Tevfik; Akpinar, Muhammet Vefa
The purpose of this research was to investigate the effects of recycled asphalt pavement (RAP) and cement content on the permeability and bearing capacity characteristics of aggregate base courses. Mixtures containing untreated RAP ranging between 0 and 100 percent and 1, 2, and 3% cement-treated RAP were subjected to laboratory tests (bitumen content, sieve analysis, modified proctor, soaked California bearing ratio (CBR), and constant-level permeability tests). The results showed that, as the RAP percentage in the mixture increased, CBR values decreased considerably. Moreover, there is a linear increase in the CBR values with cement treatment. Optimum moisture contents (OMC) and maximum dry densities (MDD) showed a decreasing trend. Increasing the cement percentages in 100% RAP blend increases the OMC and MDD values. The permeability of RAP showed a decrease as the percentage of RAP and cement increased in blends. The study showed that the CBR value of the 20% RAP blend is also obtained in the 100% RAP/3% cement-treated blend. Thus, it has been understood that cement is a suitable material in order to increase the use of RAP. In addition, the increase in the percentage of RAP and cement made the base course more impermeable.
- MakaleYalnız künye2018Adsorption of Cu(II) ions from aqueous solution by hazelnut husk activated carbon prepared with potassium acetate
Imamoglu, Mustafa; Ozturk, Asuman; Aydın, Şeyma; Manzak, Aynur; Gündoğdu, Ali; Duran, Celal
Hazelnut husk (HH), an agricultural waste, was converted to carbonaceous material by chemical activation using potassium acetate. The produced activated carbon (KAHHAC) was characterized by FTIR, SEM, N2 adsorption–desorption experiments, CHN elemental analysis, and determination of moisture, ash, and point of zero charge. KAHHAC was used for the batch adsorption of Cu(II) ions from aqueous solutions. Optimum pH and contact time were found to be 5.0 and 240 minutes, respectively. The adsorption equilibrium data were described well by the Langmuir equation providing 105.3 mg g−1 Cu(II) adsorption capacity. The pseudo-second-order model successfully described the kinetic of Cu(II) adsorption by KAHHAC. The adsorbed Cu(II) onto KAHHAC was completely desorbed by 0.5 M nitric acid. In conclusion, HH activated carbon (AC) produced by the potassium acetate activation method is a very useful and efficient sorbent material for the removal of Cu(II) from aqueous solution.
- MakaleYalnız künye2018Experimental study on cement-treated and untreated RAP blended bases: Cyclic plate loading test
Seferoğlu, Ayşegül Güneş; Seferoğlu, Mehmet Tevfik; Akpinar, Muhammet Vefa
The asphalt surrounding the reclaimed asphalt pavement (RAP) aggregates decrease the performance characteristics of road layers. RAP material increases the permanent deformation potential of road layers under the traffic load. In this study, the performances of RAP-VA (Virgin aggregate) mixtures was tested using cyclic plate loading test by adding pozzolanic cement into mixtures in order to use RAP material at the rate of 100% and to minimize the permanent deformation in plant-mix base courses (PBC). The permanent surface deformations of base course were measured at different points throughout 100 loading cycles and all of the measurements were compared to that of base course prepared from 100% VA. The effect of RAP/cement rate of mixtures on the permanent deformations was examined and it was determined that the increase in RAP rate increased the permanent deformations but cement significantly decreased it. Moreover, considering the material costs of mixtures, the cost analysis was performed and the profit margins that using RAP and cement offers to constructors were computed.
- MakaleYalnız künye2018Shelf-life, physicochemical, and nutritional properties of wheat bread with optimized amount of dried chickpea sourdough and yeast by response surface methodology
Hendek Ertop, Muge; Coşkun, Yunus
The aim of this study was to optimize of the instant active dry yeast (A) and the dried chickpea sourdough (B) amount in bread formulation and to evaluate of usage possibilities of dried chickpea sourdough in bread production by examining some quality parameters.Response surface methodology was used to determine the effects of the variable factors (Aand B) on the product volume (V), acceptability value (AV) and pore factor (PF) of the bread. The usage rates were determined 0.63% for A and 10.21% for B.The bread produced according to optimized model (OB) was compared with control bread in terms of some quality parameters. The pore structures of bread samples and microtextural features obtained scanning electron microscopy during shelf life were examined by Image Analysis. Smaller and more homogeneous pore structures were obtained in the bread texture; antioxidant activity, mineral content, microbial shelf life were improved, and the volume and crust thickness of the bread increased by the usage of chickpea sourdough. Practical applications: Chickpea sourdough was dried in oven at low temperature short time condition.The protection of microbial vitality was ensure during the drying processes.The level of instant active dry yeast (A) and dried sourdough (B) were optimized with RSM. The usage rates were determined 0.63% for A and 10.21% for B.Optimized bread and control bread were compared in terms of various quality properties. The antioxidant activity, mineral content, microbial shelf life, and physicochemical properties were improved.
- MakaleYalnız künye2018Investigation of radiation absorption coefficients of lead-zinc mine waste rock mixed heavy concrete at 662–1460 keV energy range
Çullu, Mustafa; Bakırhan, Emir
The objective of this study is to observe the radiation shielding efficiency of concrete produced by using the lead wastes that are stored in lead-zinc mines processing of which is not financially viable in the mines they are extracted from that have negative effects on the environment. Within this scope, concretes were produced to be used as radiation shield concretes. The samples were prepared by altering the amounts of heavy aggregates such as lead–zinc mine waste, Magnetite, Limonite, and Barite at 25%, 50%, and 75% ratios, and concrete samples were prepared in C16/20, C25/30, and C35/45 concrete strength grades to determine the effects of these grades on radiation absorption properties. In order to determine the radiation absorption coefficients, absorption coefficients at 662 keV, 1173 keV, 1332 keV, and 1460 keV energy levels from Cs-137, Co-60 and K-40 sources were determined by concrete slabs with dimensions of 20 × 20 × 5 cm.
- MakaleAçık Erişim2018Type, quantity, and re-use of residues in the forest products industry in Trabzon, Turkey
Top, Yener; Adanur, Hakan; Oz, Mehmet
It is necessary to know the type and quantity of wastes to select the proper applications and waste management strategies. This study investigates the type, quantity, and utilisation methods of wastes generated by micro-sized enterprises that produce timber and furniture, which are two major sub-sectors of the forest products industry in Trabzon. A total of 885 enterprises of manufacturing timber and furniture in Trabzon were identified by reviewing the records from the professional chambers of commerce. The stratified sampling method was used to compare the sub-sectors, and the sample size was determined as 120. Among these, 70 furniture- and 50 timber-producing enterprises were interviewed. The chi-square test was used to determine whether the applications of timber and furniture enterprises are dependent on each other. In general, there are no differences in waste utilisation applications and education level between the sub-sectors. The percentage of the owners/managers that received any vocational training is 77.5% in two sub-sectors. In general, engineered wood wastes are used as fuel. The majority of the owners/managers in the timber industry believe that their waste has an economic value compared to those in the furniture sector. The total amount of wood waste generated by sectors was 528 tons in a month.
- MakaleYalnız künye2017Environmental impact of Gümüşhane City, Turkey, waste area in terms of heavy metal pollution
Vural, Alaaddin; Gundogdu, Ali; Akpinar, Ibrahim; Baltaci, Cemalettin
The aim of this study is to investigate the occurrence of a heavy metal contamination in a solid waste site of Gümüşhane City, Turkey, to examine the dimensions of the risk of contamination, and to present suggestions for possible solutions. For this purpose, heavy metal contents of soil and leachate samples taken from a Gümüşhane waste site were determined by a new method, microwave plasma-atomic emission spectrometry (MP-AES). When the obtained results are compared with background and control values, it can be seen that the region carries contamination risks, especially in terms of heavy metals such as Zn, Cd, Pb, Cu, Ni, and Co. To examine the environmental effects of the landfill area in more detail, geodeposition index (Igeo), enrichment factor (EF), contamination index (PI), and combined contamination index (IPI) parameters are used. In addition, the samples taken from an area supposed to be free of pollution risk were also analyzed as control samples, and the obtained data were statistically compared with the results of the waste area. It is determined that the results of landfill waste site are dissimilar to those of comparison samples in terms of investigated metals, and that they contained higher values in general.
- MakaleYalnız künye2017Combustion properties of impregnated spruce (Picea orientalis L.) wood
Şadiye Yasar, Ş.; Said Fidan, M.; Yaşar, Mehmet; Atar, Musa; Alkan, Elif
Wooden material is one of the most commonly used construction materials since history of humanity due to its environment friendly and renewable natural source. This structure of wood material is also preferred because it is lightweight, easy to work, resistant to factors such as earthquake and fire, as compared to other used building materials. However, organic structure of the wooden material causes it to be affected negatively because of damages that might occur outdoors under inappropriate conditions. Due to this reason, in this study were investigated effects of various chemicals (impregnated and varnish type), used to prevent environmental damages (biotic, abiotic pests, fire etc.) on combustion resistance of the wood exposed to air conditions for a year. For this purpose, prepared Caucasian spruce (Picea orientalis L.) specimens were surface treated (synthetic and water-based varnish) after impregnated according to ASTM-D 1413-76 principles with various chemicals (Tanalith-E and Wolmanit-CB). Test specimens with impregnated, varnished and processless, were left in outdoor conditions for a year. Combustion experiment was conducted according to the principles in ASTM-E 160-50 combustion test standards. According to the results of the experiment, control and year specimens had close results in the weight loss. Weight loss was found be lower Wolmanit-CB impregnated specimens (92.12%) among the impregnated materials to synthetic varnish coated specimens (% 91.89) among the varnished specimens. It was determined that using Wolmanit-CB for impregnating and synthetic varnish for varnishing would be better according to the results. Furthermore, the amount of O2 (25.84 ppm) in control specimens in combustion with flame; the amounts of CO and CO2 (31787, 19.92 ppm respectively) in year specimens in combustion without flame and the amount of NO (54.65 ppm) in year specimens in glowing was observed to be the highest.
- MakaleYalnız künye2016Therotical investigation of the effects of diesel fuel, biodiesel fuel and their blends on internal combsution engines
Sezer, Ismet
In this study; the effects of diesel fuel, the soybean oil methyl ester (SOME) biodiesel fuel and their blends at various percentages on the spray and combustion characteristics and engine performance and exhaust emissions of diesel engines investigated as theoretically. For this purpose, a model has been built for a direct injection diesel engine in a commercial vehicle by the Diesel-RK software program that can be used liberally on the net. The obtained values for diesel (D) and biodiesel (BD) fuels and D-BD fuel blends via the constructed model were compared. The results of the study show that BD fuel generally provides a close brake thermal efficiency values to diesel fuel. Additionally, BD fuel causes decrements in engine power and particulate matter (PM-soot) emission and increments in specific fuel consumption and nitric oxides (NOx) emission. On the other hand, D-BD fuel blends at various blend ratios have usually given the spray, combustion, performance, and emission values between those of diesel and biodiesel fuels.
- MakaleAçık Erişim2016Combustion Characteristics of Impregnated and Surface-treated Chestnut (Castanea sativa Mill.) Wood Left Outdoors for One Year
Fidan, Muhammed Said; Yaşar, Şekip Şadiye; Yaşar, Mehmet; Atar, Musa; Alkan, Elif
Treating wood with impregnating materials in order to improve resistance to burning is a commonly employed safety measure. In this study, chestnut (Castanea sativa Mill.) wood samples were impregnated using either Tanalith-E or Wolmanit-CB according to ASTM-D 1413-76 and surface-treated using water-based or synthetic varnish according to ASTM-D 3023. These samples were used to investigate the combustion characteristics of samples left outdoors for one year as detailed in ASTM-E 160-50. The combustion temperatures of the samples left outdoors were similar upon impregnation with either Tanalith-E or Wolmanit-CB. However, the combustion temperature of the samples treated with synthetic varnish was lower than those that were treated with water-based varnish. The time to collapse and the total duration of combustion of the samples left outdoors were shorter for those impregnated with Wolmanit-CB. Weight loss of the samples left outdoors was higher for those that were impregnated with Tanalith-E and treated with water-based varnish. Gas analysis of the samples that were left outdoors indicated that the O2 content of flue gas from samples that were impregnated with Wolmanit-CB and treated with synthetic varnish was high and the CO content of flue gas from the same samples was low.
- MakaleYalnız künye2016Application of response surface methodology for optimizing the recovery of phenolic compounds from hazelnut skin using different extraction methods
Odabaş, Halil İbrahim; Koca, Ilkay
Hazelnut skin which is a rich source of phenolic compounds is a by-product of hazelnut roasting process. In present study, ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE) and supercritical carbon dioxide extraction (SCE) methods were applied for recovery of phenolic compounds from hazelnut skin. Response surface methodology was used to estimate optimum extraction conditions. Extraction studies were performed according to Box-Behnken Design. Temperature (UAE)/power (MAE), time and ethanol concentration were independent variables for UAE and MAE. The independent variables selected for SCE were temperature, time and pressure. The optimum extraction conditions were 45 min and 67.2–67.6% ethanol concentration, 600 W, 6 min and 55.03–56.23% ethanol concentration and 42.72–49.10 °C, 59.83–60.00 min and 10.01–11.48 bar, for UAE, MAE and SCE respectively. Total phenolic content, FRAP and 1/EC50 values at the optimum conditions were 122.99–123.01 mg GAE/g, 612.20–613.25 mmol Fe(II)/g and 4.36 mL/mg for UAE, 111.53–111.55 mg GAE/g, 582.44–582.52 mmol Fe(II)/g and 2.48 mL/mg for MAE and 69.59–72.64 mg GAE/g, 426.25–465.52 mmol Fe(II)/g and 2.18–2.27 mL/mg for SCE, respectively. Maceration was performed for comparison with novel methods. UAE was found to be the best method of the extraction of phenolic compounds from hazelnut skin with the highest total phenolic content and antioxidant activity values.
