Supercritical Carbon dioxide Treatment of the Microalgae Nannochloropsis oculata

The aim of this work was to evaluate the potential of supercritical carbon dioxide (CO2) to extract Fatty Acid Methyl Esters (FAME) from the microalgae Nannochloropsis oculata (N. oculata) at low temperatures (37 and 55 oC) and pressures (5.9 and 7.6 megapascals (MPa)). A qualitative gas chromatography (GC) analysis showed that the individual FAMEs extracted varied depending on the co-solvent (methanol or hexane) used with supercritical CO2. Using hexane, FAME compounds produced were similar to those extracted with soxhlet extraction alone while longer chain FAME were produced when methanol was the co-solvent. The effects of pressure and temperature variations were shown to be of statistical significance. The chromatograms produced in this work demonstrate that altering one of these parameters (co-solvent, temperature, pressure) can produce different compounds owing to the tunability of the technique

Integrating anaerobic digestion and slow pyrolysis improves the product portfolio of a cocoa waste biorefinery

The integration of conversion processes with anaerobic digestion is key to increase value from agricultural waste, like cocoa pod husks, generated in developing countries. The production of one metric ton of cocoa beans generates some 15 metric tonnes of organic waste that is today underutilized. This waste can be converted into added value products by anaerobic digestion, converting part of the cocoa pods to biogas while releasing nutrients, and pyrolysis. Here, we compared different scenarios for anaerobic digestion/slow pyrolysis integration in terms of product portfolio (i.e., biogas, pyrolysis liquids, biochar and pyrolysis gases), energy balance and potential for chemicals production. Slow pyrolysis was performed at 350 degrees C and 500 degrees C on raw cocoa pod husks, as well as on digestates obtained from mono-digestion of cocoa pod husks and co-digestion with cow manure. Anaerobic digestion resulted in 20 to 25 wt% of biogas for mono and co-digestion, respectively. Direct pyrolysis of cocoa pod husks mainly resulted in biochar with a maximum yield of 48 wt%. Anaerobic digestion induced compositional changes in the resulting biochar, pyrolysis liquids and evolved gases after pyrolysis. Pyrolysis of mono-digestatee.g., resulted in a more energy-dense organic phase, rich in valuable phenolics while poorer in light oxygenates that hold a modest value. Our comparison shows that co-digestion/slow pyrolysis at 500 degrees C and mono-digestion/slow pyrolysis at 350 degrees C both present high-potential biorefinery schemes. They can be self-sustaining in terms of energy, while resulting in high quality biochar for nutrient recycling and/or energy recovery, and/or phenolics-rich pyrolysis liquids for further upgrading into biorefinery intermediates

Proje Temelli Eğitimin Kümeleme ve Sınıflama Algoritmaları İle Değerlendirilmesi

Günümüzde bilgisayar teknolojileri her alanda etkin rol oynamaktadır. Teknolojinin gelişmesiyle her ortamda veriler daha kolay tutulmakta ve bu verileri bilgisayar programları aracılığıyla analiz edecek uzman kişilere olan talep de bu duruma müteakip dünya genelinde artmaktadır. Veri analizi konusunda yeterli düzeyde teorik bilgi edinen Ekonometri mezunlarının Veri Analisti olarak kariyerlerini devam ettirmelerindeki en büyük engel ise bilgisayar teknolojilerine olan uzaklıklarıdır. Bu nedenle Ekonometri Bölümü öğrencilerinin bilgisayar kullanım düzeylerini arttıracak eğitimsel yaklaşımlar gerekmektedir. Bilgisayarda yetkinliğin uzun süreli ve ders saatleri dışında da yapılacak olan çalışmalarla kazanılabilmesi nedeniyle proje tabanlı ders yaklaşımları bu durumlarda kullanılabilmektedir. Projeler ile öğrenciler ekip çalışması, araştırma yeteneği, uygulayarak öğrenme ve kendi başlarına öğrenme gibi birçok alanda kendilerini geliştirme şansına sahip olmaktadırlar. Çalışmada bilgisayar ortamında paket programlar kullanılarak proje çalışması yapılan derslerin lisans öğrencilerinin eğitimlerine ne ölçüde etki ettiği incelenmiştir. Bu kapsamda, Likert ve Boolean tipi değişkenlerden meydana gelen bir anket hazırlanmış ve Dokuz Eylül Üniversitesi Ekonometri Bölümü öğrencisi olan 184 kişiye uygulanmıştır. Anket verileri veri madenciliği teknikleri olan iki aşamalı kümeleme ve Ki Kare ölçütlü sınıflama yöntemleriyle değerlendirilerek önemli çıkarımlar sağlanmıştır

Regional intravenous anesthesia in knee arthroscopy

OBJECTIVE: The goal of the study was to investigate the regional intravenous anesthesia procedure in knee arthroscopy and to evaluate the effects of adding ketamine over the anesthesia block charactery and tourniquet pain. MATERIAL/METHOD: Forty American Society of Anesthesiologists (ASA) II patients who received knee arthroscopy were enrolled. After monitoring, a peripheral IV line was inserted.The venous blood in the lower extremity was evacuated with a bandage, and the proximal cuff of the double-cuff tourniquet was inflated. The patients were randomly split into two groups. While Group P received 80 ml 0.5% prilocaine, Group PK received 0.15 mg/kg ketamine (80 ml in total) via the dorsum of the foot. We recorded onset time of the sensory block, end time of the sensory block, presence of the motor block, the time when the patient verbally reported tourniquet pain and surgical pain, duration of tourniquet tolerance, fentanyl consumption during the operation, time to first analgesic requirement, methemoglobin values at 60 minutes, operative conditions, 24-hour analgesic consumption, discharge time, and hemodynamic parameters. RESULTS: The body mass index (BMI) of the patients who required general anesthesia was significantly higher than the BMI of other patients. The onset time of the sensory block was shorter for those in Group PK, but the time to first analgesic requirement was longer. CONCLUSION: Regional intravenous anesthesia using the doses and volumes commonly used in knee arthroscopy may be an inadequate block among patients with high BMI values. Moreover, the addition of ketamine to the local anesthetic solution may produce a partial solution by shortening the onset of sensory block and prolonging the time until the first analgesic is required

Regional intravenous anesthesia in knee arthroscopy

OBJECTIVE: The goal of the study was to investigate the regional intravenous anesthesia procedure in knee arthroscopy and to evaluate the effects of adding ketamine over the anesthesia block charactery and tourniquet pain. MATERIAL/METHOD: Forty American Society of Anesthesiologists (ASA) II patients who received knee arthroscopy were enrolled. After monitoring, a peripheral IV line was inserted.The venous blood in the lower extremity was evacuated with a bandage, and the proximal cuff of the double-cuff tourniquet was inflated. The patients were randomly split into two groups. While Group P received 80 ml 0.5% prilocaine, Group PK received 0.15 mg/kg ketamine (80 ml in total) via the dorsum of the foot. We recorded onset time of the sensory block, end time of the sensory block, presence of the motor block, the time when the patient verbally reported tourniquet pain and surgical pain, duration of tourniquet tolerance, fentanyl consumption during the operation, time to first analgesic requirement, methemoglobin values at 60 minutes, operative conditions, 24-hour analgesic consumption, discharge time, and hemodynamic parameters. RESULTS: The body mass index (BMI) of the patients who required general anesthesia was significantly higher than the BMI of other patients. The onset time of the sensory block was shorter for those in Group PK, but the time to first analgesic requirement was longer. CONCLUSION: Regional intravenous anesthesia using the doses and volumes commonly used in knee arthroscopy may be an inadequate block among patients with high BMI values. Moreover, the addition of ketamine to the local anesthetic solution may produce a partial solution by shortening the onset of sensory block and prolonging the time until the first analgesic is required

Electrochemical upgrading of bio-oil: A proof-of-principle investigation

Fast pyrolysis is an advanced thermochemical conversion technology developed to produce bio-oil from biomass. With lignocellulosic biomass, high product yields (65-75 wt.%) can be attained. Yet, certain unfavorable characteristics of bio-oil impede its utilization prospects. High water content, high oxygen content, together with instability and acidity are the recognized adverse features of bio-oil. Tackling these issues is possible by reducing the oxygen content and/or steering the oxygen functionality of bio-oils. Electrochemical hydrogenation (ECH) is a recently proposed approach targeting the reduction of the reactive compounds in bio-oil (aldehydes, ketones etc.) to their corresponding alcohols, diols [1]. In this attractive approach, the water present in bio-oil acts as the hydrogen source for reduction reactions. Production of alcohols/diols leads to an upgraded/stabilized bio-oil product. Performing the upgrading at ambient temperature, pressure and providing a means to store intermittently available renewable energy (e.g. solar, wind) are clear advantages of the ECH process. In this work, we have investigated electrochemical upgrading of bio-oil using water soluble bio-oil (WSBO) as feed. The ECH experiments, carried out in an electrochemical reactor at a current density of 44 mA cm-2, focused on comparison of several cathode materials. Separated by a cation exchange membrane, cathode and anode chambers of the reactor were filled with WSBO (ca. 20 wt.% bio-oil in aqueous solution) and 1M H2SO4, respectively. The tested cathode materials included Ti, Ru-coated Ti (Ru), Pt-coated Ti (Pt), stainless steel (SS) and CuZn (brass) electrodes. All electrodes converted the carbonyl groups present in bio-oil to a certain extent following the order CuZn\u3e\u3eSS\u3eTi\u3ePt\u3eRu. The trend is explained in close relation with the hydrogen evolution reaction, the preferred pathway especially with Pt and Ru electrodes. Despite the high conversions achieved for some compounds, the selectivity towards desired alcohols and diols was not very high (e.g. 15 – 49% ethylene glycol selectivity for glycolaldehyde conversion) for the electrodes tested in this study. Low Faradaic efficiencies obtained are considered as another challenge keeping the conversion costs high. Nevertheless, electrochemical hydrogenation appears to be a promising technology to upgrade/stabilize bio-oil that deserves further investigation. Next to the experimental results obtained, possible future improvements in catalytic cathode selection and processing options will be discussed as well. References [1] Z. Li, S. Kelkar, L. Raycraft, M. Garedew, J.E. Jackson, D.J. Miller, C.M. Saffron, Green Chem., 2014, 16, 844

Üç Farklı Aydınlatma Programında Yetiştirilen Amerikan Bronz Hindilerinde Değişik Vücut Ölçüleri ile Canlı Ağırlık Arasındaki İlişkilerin Path Analizi ile İncelenmes

Hayvan ıslahı ve genetiğinde, sebep-sonuç ilişkilerinin bilinmesi seleksiyon hakkında önemli ipuçları verebilir. Sebep değişkenlerinin üzerinde durulan özelliklere katkılarının farklı olması, söz konusu özelliklere en fazla katkı yapan değişkenlerin belirlenmesini gerektirir. Bu çalışmada, Amerikan Bronz Hindilerinin tespit edilen dört özelliğinin incik uzunluğu, göğüs uzunluğu, göğüs derinliği ve göğüs çevresi , 30. hafta canlı ağırlık üzerine doğrudan ve dolaylı etkileri iz katsayısı metodu Path analizi kullanılarak analiz edilmiştir. Analiz sonuçları, canlı ağırlık üzerine en fazla doğrudan etkiye sahip olan değişkenin incik uzunluğu değişkeninin olduğunu göstermiştir. Genel olarak, göğüs uzunluğu ve göğüs çevresi değişkenlerinin incik uzunluğu üzerinden olan dolaylı etkileri de daha yüksek bulunmuştur. Buradan hareketle, 30. hafta canlı ağırlığa en etkili değişkenin incik uzunluğu olduğu ve bunun modele dahil edilmesinin gerekli olduğu sonucuna varılmıştı