In this study, different methods, including acid hydrolysis (phosphoric and formic acid), thermohydrolysis, and microwave methods were tested for recycling of fiberboards made of 100 % beech and 70 % ...beech + 30 % pine wood fibers, which are widely sold in the market. The impacts of the using methods on the fibers were investigated with the help of a device that determines the fiber dimensions according to optical principles. In a laboratory setting, test boards were constructed using recycled fibers, and the changes in certain physical and mechanical qualities were studied. As a result, it was determined that recycled fibers obtained from microwave and thermo-hydrolysis fibers could be effectively used in fiberboard production. However, the proportion of fibers, longer than 1.24 mm, was decreased by about 30 % with the phosphoric acid method for MDF samples composed of 100 % beech fiber. The fiberboards could not be obtained from fibers recycled through acid hydrolysis except for phosphoric acid method with 100 % beech fibers.
U radu se istražuju različite metode recikliranja ploča vlaknatica kao što su kiselinska hidroliza (uz pomoć fosforne i mravlje kiseline), toplinska hidroliza i mikrovalne metode. Reciklirani su uzorci ploča vlaknatica izrađenih od 100 % vlakana drva bukve te ploča vlaknatica izrađenih od 70 % vlakana drva bukve i 30 % vlakana drva crnog bora. Ploče vlaknatice takvog sastava uvelike su zastupljene na tržištu. Utjecaj metoda recikliranja na vlakna istraživan je uz pomoć uređaja kojim se određuju dimenzije vlakana na optičkim načelima. Ploče od recikliranih vlakana izrađene su u laboratorijskim uvjetima i na njima su promatrane promjene određenih fizičkih i mehaničkih svojstava. Utvrđeno je da se reciklirana vlakna dobivena mikrovalnim metodama i toplinskom hidrolizom mogu učinkovito primjenjivati u proizvodnji ploča vlaknatica. Međutim, kiselinskom hidrolizom uz dodatak fosforne kiseline u uzorcima izrađenim od 100 % bukovih vlakana udio vlakana duljih od 1,24 mm smanjuje se za oko 30 %. Ploče vlaknatice nisu se mogle proizvesti od recikliranih vlakana dobivenih kiselinskom hidrolizom. Za njihovu proizvodnju pogodna su se pokazala samo reciklirana vlakna od 100 % bukovih ploča vlaknatica srednje gustoće dobivena kiselinskom hidrolizom uz dodatak fosforne kiseline.
Lignin characteristics are significantly affected by kraft processing and isolation conditions. In the studies carried out in this context, commercial lignins or isolated lignins from industrial ...black solutions are generally preferred. In this study, in order to conduct more comprehensive research, three lignin samples were isolated from kraft black liquor obtained from laboratory cooking trials of pine, poplar, and wheat straw chips, representing softwoods, hardwoods, and annual plants, respectively, according to efficient pulping studies. In addition, another lignin-containing industrial waste was provided from a pulp mill (OBL). The acidification method was applied for isolating lignin from black liquor samples. After isolating the lignin samples from different sources, they were characterized and compared with the commercially available kraft lignin sample (Indulin AT). Total phenolic groups, carboxyl groups, purity, functional groups, nitrobenzene oxidation products, molecular weight, thermal stability, and element contents were analyzed. The isolated lignin samples (except wheat straw) were as pure as commercial lignin. Since the wheat straw was agricultural waste and an annual plant, inorganic elements such as P, K, and Si were more abundant than in the other samples. However, the polydispersity and molecular weight of all of the isolated lignin samples were higher than those of commercial lignin. Because the ash contents of the lignin samples for pine, poplar, OBL, and indulin AT were between 1 and 3%, they can be used for high-value applications. In particular, despite some disadvantages, wheat straw lignin has greater potential for use in extruders than softwood lignins due to their syringyl content.
The aim of the study is to investigate the production possibilities of particleboard by using waste tirerubbers with different properties as fillers and find a solution to a serious environmental ...pollution problem caused by waste tires. For this purpose, waste summer and winter tires were ground, rubber powders were obtained by separating rubber materials from other materials, and particleboards with different properties were produced using this sawdust in different percentages. The oven-dry density, air-dry density, and equilibrium moisture content at (65±5) % RH and (20±2) ºC, thickness swelling (TS, 2 hours and 24 hours), water absorption (WA, 2 hours and 24 hours) characteristics, bending strength, modulus of elasticity, and internal bond strength were determined according to the applicable European standards. The hydrophobic nature of the tire rubber enhanced the water absorption ratios of particleboards. In addition, mechanical performance of groups was affected by tire content, and it was mainly determined that the values decreased dramatically with increasing tire content. It was especially observed that this decrease was more pronounced when subtracting 30 % to 20 % waste tire content. The groups including winter waste tire rubber achieved better performance than summer waste tire groups. The use of waste rubber in boards resulted in a decrease in the equilibrium moisture content and mechanical strength of the samples.
Cilj ovog rada bio je istražiti mogućnosti proizvodnje ploča iverica iskorištenjem otpadnih autoguma različitih svojstava kao punila te pronalaženje rješenja za ozbiljno onečišćenje okoliša otpadnim autogumama. Za potrebe eksperimenta samljevene su otpadne ljetne i zimske autogume, a odvajanjem gumenih od negumenih dijelova dobiven je prah gume, koji se u različitim omjerima upotrebljavao za proizvodnju ploča iverica različitih svojstava. Prema europskim standardima određena su ova svojstva ploča iverica: gustoća u apsolutno suhom i prosušenom stanju, relativni sadržaj vode pri (65±5) RH i (20±2) °C, debljinsko bubrenje (TS, nakon 2 sata i 24 sata) i upijanje vode (WA, nakon 2 sata i 24 sata). Zbog hidrofobne prirode praha autoguma povećani su omjeri upijanja vode ploča iverica. Osim toga, udjel dodane količine praha autoguma utjecao je na mehanička svojstva ploča iverica te je utvrđeno da se te vrijednosti drastično smanjuju s povećanjem količine praha autoguma u pločama. Posebno je naglašeno smanjenje mehaničkih svojstava ploča iverica kada udio praha autoguma prijeđe 20 %. Uzorci ploča iverica s prahom od zimskih guma imali su bolja svojstva od uzoraka s prahom od ljetnih guma. Uporaba otpadnih autoguma u proizvedenim ivericama rezultirala je smanjenjem ravnotežnog sadržaja vode i mehaničke čvrstoće uzoraka.
Wood bark is a residue of forestry production that is used as a fuel source. The chemical composition of tree bark is similar to that of the harvested wood, and it contains a variety of useful ...compounds. To determine the chemical composition and antioxidant activities of different barks, fir (Abies nordmanniana), beech (Fagus orientalis), pine (Pinus sylvestris), poplar (Populus alba), and oak (Quercus robur) barks were selected because they are used for industrial purposes in Turkey. The dried bark powders were extracted using a 65:35 methanol-water mixture (v/v) to determine the total phenolic content, the flavonoid content, and the antioxidant properties (2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), metal chelating, and H2O2 scavenging). The flavonoid components were analyzed by high performance liquid chromatography (HPLC) and extracted by hexane to analyze the volatile components by gas chromatography-mass spectrometry (GC-MS). The poplar bark extracts had the highest total phenolic content, highest total flavonoid content, and highest antioxidant content. The poplar bark extracts were rich in myricetin (87.761 mg/L), which is a flavonoid with rich antioxidant properties. The presence of valuable extracts suggests that barks may have uses as valuable raw materials for chemical applications such as cosmetics, perfumes, and food preservatives.
The rapid population growth, increasing global energy demand, climate change, and excessive use of fossil fuels have adversely affected environmental management and sustainability. Furthermore, the ...requirements for a safer ecology and environment have necessitated the use of renewable materials, thereby solving the problem of sustainability of resources. In this perspective, lignocellulosic biomass is an attractive natural resource because of its abundance, renewability, recyclability, and low cost. The ever-increasing developments in nanotechnology have opened up new vistas in sensor fabrication such as biosensor design for electronics, communication, automobile, optical products, packaging, textile, biomedical, and tissue engineering. Due to their outstanding properties such as biodegradability, biocompatibility, non-toxicity, improved electrical and thermal conductivity, high physical and mechanical properties, high surface area and catalytic activity, lignocellulosic bionanomaterials including nanocellulose and nanolignin emerge as very promising raw materials to be used in the development of high-impact biosensors. In this article, the use of lignocellulosic bionanomaterials in biosensor applications is reviewed and major challenges and opportunities are identified.
The total phenolic content (TPC), total flavonoid content (TFC), phenolic compounds, and antifungal activity of olive (Olea europaea var. sylvestris) and juniper (Juniperus foetidissima) sapwood and ...heartwood extractives were examined. The extractives were obtained using methanol solvents. The different compounds in extractives were identified and quantified. The antifungal activities of different parts of the olive and juniper wood extractives were determined in vitro. Pleurotus ostreatus mycelium was used for the antifungal activity experiment. Extractive compounds obtained from olive and juniper woods were found to be effective, natural antifungal agents.
Aim of study: The objectives in this study were to determine the chemical composition and antimicrobial activity of the essential oils from nutmeg (Myristica fragrans) and cardamom (Elettaria ...cardamomum).Material and Methods: The essential oil was obtained from nutmeg and cardamom seeds through hydrodistillation method. The chemical composition of nutmeg and cardamom essential oil was analyzed by GC-MS. The antimicrobial activity of essential oil was investigated against Bacillus subtilis DSMZ 1971, Candida albicans DSMZ 1386, Enterococcus faecalis ATCC 29212, Enterobacter aerogenes ATCC 13048, Enterococcus durans, Enterococcus faecium, Escherichia coli ATCC 25922, Klebsiella pneumoniae, Listeria monocytogenes, Listeria innocua, Pseudomonas aeruginosa DSMZ 50071, Pseudomonas fluorescence P1, Salmonella enteritidis ATCC 13076, Salmonella infantis, Salmonella kentucky, Salmonella typhimurium SL 1344, Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis DSMZ 20044 with minimum inhibitory concentration (MIC) method.Main results: GC-MS analyzes shows that γ-terpinene (19.16%), (-)-terpinen-4-ol (14.08%), α-pinene (6.75%), myristicin (6.18%), β-pinene (4.85%), sylvestrene (4.72%), elemicin (4.68%) and safrole (4.17%) identified in nutmeg essential oil. Also, α-terpinyl acetate (34.55%), eucalyptol (24.91%), (-)-terpinen-4-ol (10.63%), linalool (7.69%) and neryl butyrate (6.58%) compounds identified in cardamom essential oil as major compounds. Nutmeg and cardamom essential oil showed an antimicrobial activity against almost all test microorganisms.Research highlights: This study suggests that nutmeg and cardamom essential oil may be useful in the medicinal application and food industry as a preservative.
In this study, DNA protective, antioxidant, antibacterial and enzyme inhibiting properties of methanol extracts obtained from juniper and olive heartwood and sapwood were determined. These extracts ...were tested by five antioxidant methods (DPPH scavenging, FRAP, CUPRAC, metal chelating and phosphomolybdenum). Generally, heartwood extracts of both species are more efficient for DPPH radical scavenging activity, cupric ion reducing activity, ferric reducing antioxidant power and metal chelating activity than sapwood extracts. When compared to heartwood extracts, sapwood extracts have larger inhibition zone in disk diffusion test. In addition, all extracts showed high antibacterial activity against
Staphylococcus aureus
. DNA protection of both extracts had a capacity to inhibit the DNA damage arisen from Fenton's reagent. The highest DNA protective activity was observed in juniper sapwood extract with 84%. Furthermore, other extracts also indicated more than 60% of DNA protective activity. Olive wood extracts displayed the strongest enzyme inhibition activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Although juniper heartwood extracts showed highest anti-amylase, anti-glucosidase and anti-tyrosinase effects, they had no ability for inhibition BChE. The methanol extracts of olive samples demonstrated the most antioxidant activity (DPPH, CUPRAC and FRAP). In addition, juniper samples showed the highest anti-amylase, anti-tyrosinase, metal chelating and DNA protective activity. According to these results, the extracts of juniper and olive wood can be considered as a source of natural bio active agents for dietary, pharmacological and medicinal applications. This research will also serve as a base for future studies about biological activities of wood extracts.
In this study, DNA protective, antioxidant, antibacterial and enzyme inhibiting properties of methanol extracts obtained from juniper and olive heartwood and sapwood were determined.
Defibration is one of the most energy spent stage in pulp and fiberboard production. Today’s different methods are available for reducing energy needs at this stage. Fungi usage is an important ...method for this purpose in recent decades. In this study, beech chips (Fagus orientalis), which is the most widely used in the Turkish fiberboard industry, are pretreated with edible Pleurotus ostreatus white rot fungi and investigated the effects of the chemical content of the chips. Consequently, totally 7727.6 gr P. ostreatus mushroom is obtained and the lignin content of wood chips is dramatically decreased day by day. It was observed that lignin content of wood chips decreased by 22.03% at 72th day after starting of fungi to emerge. Accordingly this results, it will be potentially saved the mechanical fibrillation energy, because dissolving the desired amount of lignin during fiberizing is reduced.
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