ORMAN ÜRÜNLERİ İŞLETMELERİNDE ODUNSU ATIK YÖNETİMİ UYGULAMALARININ DEĞERLENDİRİLMESİ

Doğal kaynakların sınırlı olduğu günümüzde atık malzemelerin değerlendirilerek yeni ürünler olarak ekonomiye kazandırılması önemli bir rol oynamaktadır. Bu çalışmada, Muğla İli genelindeki orman ürünleri endüstrisi işletmelerinde ortaya çıkan odun atıklarını değerlendirilme yöntemleri araştırılmıştır. Bu kapsamda, 50 orman ürünleri işletmesine anket uygulanmıştır. Elde edilen veriler parametrik olmayan yöntemlerle analiz edilmiştir. Orman ürünleri işletmelerinin odun atıklarını değerlendirme yöntemleri araştırılarak mevcut durum açıklanmıştır. Daha sonra ise, işletmelerde odun atık yönetiminde kullanılan alternatif yöntemler değerlendirilmiştir. İşletmelerin, düşük yatırım maliyetleri ile odun atıklarını piyasaya alternatif ürünler şeklinde sunarak, sınırlı kaynakların kullanılmasına katkı sağlayabilecekleri ve yeni bir gelir kalemi oluşturabilecekleri sonucuna ulaşılmıştır

Activated Carbon and Cellulose-reinforced Biodegradable Chitosan Foams

Chitosan foams with promising mechanical properties, heat-insulating ability, and flame retardancy were produced through oven drying. The chitosan foams were reinforced with cellulose, boric acid, and different ratios of activated carbon. The foams showed desirable low density (80.2 to 109.8 kg/m3) and compression properties. The compression resistance and compression modulus of foams ranged between 53.6 and 98.5 KPa and 214 to 394 KPa, respectively. Thermal conductivity tests revealed that the foams endowed low thermal conductivity values (0.035 to 0.051 W/mK). The limiting oxygen index (LOI) of the foams was as high as 32.9% for activated carbon (20 g/L). The activated carbon reinforcement produced higher thermal properties and decreased the mass loss 48.1% at 600 °C. The produced foams exhibited good biodegradability (39% degradation in 15 days). The overall test results showed that the chitosan foams can be utilized as a promising environmentally friendly material in thermal insulation fields

Activated Carbon and Cellulose-reinforced Biodegradable Chitosan Foams

Chitosan foams with promising mechanical properties, heat-insulating ability, and flame retardancy were produced through oven drying. The chitosan foams were reinforced with cellulose, boric acid, and different ratios of activated carbon. The foams showed desirable low density (80.2 to 109.8 kg/m3) and compression properties. The compression resistance and compression modulus of foams ranged between 53.6 and 98.5 KPa and 214 to 394 KPa, respectively. Thermal conductivity tests revealed that the foams endowed low thermal conductivity values (0.035 to 0.051 W/mK). The limiting oxygen index (LOI) of the foams was as high as 32.9% for activated carbon (20 g/L). The activated carbon reinforcement produced higher thermal properties and decreased the mass loss 48.1% at 600 °C. The produced foams exhibited good biodegradability (39% degradation in 15 days). The overall test results showed that the chitosan foams can be utilized as a promising environmentally friendly material in thermal insulation fields

Effect of mica powder-filled styrene-butadiene rubber compounds on crosslink density and mechanical properties

In this study, four different compounds were produced by adding different proportions of mica powder (0-5-10-20%) to styrene-butadiene rubber. After vulcanization, the crosslink density, hardness, density, tensile strength, elongation percentage, and tearing strength of the compounds were measured. In addition, the effects of crosslink density on mechanical properties were discussed. The physio-mechanical properties of the new compounds produced were compared both among them­selves and with the properties of the rubber being referenced. It was observed that increasing the crosslink density of mica powder provided an advantage in terms of hardness, tensile strength, tearing strength, and percentage elongation properties. To explain the changes in mechanical properties, the tensile fracture surfaces were determined by SEM and energy dispersive spectroscopy. In the light of the obtained results, it was determined that the use of carbon black could be reduced by using mica powder in the rubber industry

SOME SURFACE PROPERTIES OF HEAT TREATED AND NATURAL WEATHERED ORIENTAL BEECH

ABSTRACT This study was performed to investigate some surface characteristics such as color, surface roughness and glossiness of heat treated Oriental beech (Fagus orientalis L.) wood specimens after natural weathering. Heat treatment of Oriental beech wood was carried out by hot air in an oven for 1, 4, and 8 h at 140, 170, and 200°C. Our results showed that heat treatment caused decrease in surface roughness and glossiness of Oriental beech. The decrease in L* of heat treated wood indicates that the specimens become darker. Heat treatment resulted in better surface roughness and glossiness compared to nonheated Oriental beech after natural weathering. According to our results, while heat treated Oriental beech wood specimens become lighter after natural weathering, non-heated wood become darken after natural weathering. The negative values of Δa* and Δb* indicate a tendency of wood surface to become greenish and bluish after natural weathering. Generally, higher temperature and duration of treatment resulted in better surface characteristics of Oriental beech after natural weathering

Properties of Oak Wood Incorporating Microencapsulated Phase Change Material

Microencapsulated phase change materials (MPCMs) incorporated into oak wood via vacuum impregnation have shown promise as thermal energy storage (TES) materials. Physical and chemical properties of MPCMs and resulting Phase Change Energy Storage Wood (PCESW) were analyzed. Scanning electron microscopy and particle size analyses revealed similar particle sizes, while X-ray diffraction (XRD) and Fourier transform infrared spectra confirmed crystal phase and chemical structure. Thermal gravimetric analysis (TGA) and differential scanning calorimetry determined thermal properties, including phase change temperature, enthalpy, thermal stability, and conductivity. The MPCMs exhibited a phase change enthalpy of 146.0 J/g and temperature of 35.0 °C, with excellent thermal stability. The FTIR, XRD, and TGA analyses showed unchanged chemical structure, crystallinity ratios, and decomposition in two stages, respectively. The PCESW exhibited a latent heat storage of 3.02 J/g at 25.4 °C. Decay tests demonstrated noticeably reduced weight loss (1.22% and 1.55%) for MPCMW samples treated with Trametes versicolor and Coniophora puteana, compared to unleached control samples (19.7% and 20.8%). These findings indicate the high efficiency and potential of PCESW as a thermal energy storage material

Loop security and tensile properties of polyblend and traditional suture materials

Tensile and knot properties of new generation (polyblend) and traditional suture materials in orthopedic surgery were investigated in standard laboratory conditions. Study focused on Fiberwire No. 5 and 2, Ethibond No. 5, 2 and 00, Orthocord No. 2, MaxBraid No. 2, Prolene No. 0 and 00, PDS No. 0 and 00, and Vicryl No. 2, 0 and 00. A 27-cm suture loop was fastened with 10 knots for ten samples for each type. Test parameters were tensile load to failure, elongation at failure point and knot slippage, and volume of 10-fold knots. Results were compared using ANOVA test. Failure load of No. 5 Fiberwire (625.0 +/- A 30.0 N) was significantly higher compared to all other suture types. Tensile strengths of MaxBraid No. 2 (287 +/- A 11 N) was significantly stronger compared to two other No. 2 polyblend sutures types and Ethibond No. 5. Knot slippage of Fiberwire No. 5 (14 +/- A 1.9 mm) was significantly higher compared to all other suture types. Ethibond No. 2 (0.1 +/- A 0.3 mm) had the lowest knot slippage. Elongation at the failure point of Fiberwire No. 2 (5%) was significantly lower than all other suture types. Mean calculated knot volume of #5 Fiberwire (73 +/- A 6.9 mm(3)) was significantly higher compared to #5 Ethibond (53 +/- A 4.8 mm(3)). Results of the study proved presence of significant differences between tensile and knot properties of various suture types and sizes. Loop security of larger diameter sutures is not always higher than thinner sutures. Suture elongation and knot slippage are important failure modes for high-diameter sutures and short-suture loops

Biomechanical Comparison of Fixation Techniques in Midshaft Clavicular Fractures

Objectives: The purpose of this study is to evaluate the biomechanical properties and the stability among a locking clavicle plate (LCP), a dynamic compression plate (DCP) and an external fixator (Ex-fix) in an unstable displaced clavicle fracture model under torsional and three-point bending loading

COVID-19 in kidney transplant recipients: A multicenter experience in Istanbul.

© 2020 Wiley Periodicals LLCIntroduction: Management of COVID-19 in kidney transplant recipients should include treatment of the infection, regulation of immunosuppression, and supportive therapy. However, there is no consensus on this issue yet. This study aimed to our experiences with kidney transplant recipients diagnosed with COVID-19. Material and Methods: Kidney transplant recipients diagnosed with COVID-19 from five major transplant centers in Istanbul, Turkey, were included in this retrospective cohort study. Patients were classified as having moderate or severe pneumonia for the analysis. The primary endpoint was all-cause mortality. The secondary endpoints were acute kidney injury, the average length of hospital stay, admission to intensive care, and mechanical ventilation. Results: Forty patients were reviewed retrospectively over a follow-up period of 32 days after being diagnosed with COVID-19. Cough, fever, and dyspnea were the most frequent symptoms in all patients. The frequency of previous induction and rejection therapy was significantly higher in the group with severe pneumonia compared to the moderate pneumonia group. None of the patients using cyclosporine A developed severe pneumonia. Five patients died during follow-up in the intensive care unit. None of the patients developed graft loss during follow-up. Discussion: COVID-19 has been seen to more commonly cause moderate or severe pneumonia in kidney transplant recipients. Immunosuppression should be carefully reduced in these patients. Induction therapy with lymphocyte-depleting agents should be carefully avoided in kidney transplant recipients during the pandemic period