In this study, halogen-free flame retardants and metal synergist materials were used to enhance the flammability of PA6. PA6-based composites including various fractions of additives were manufactured using a twin-screw extruder and an injection molding machine. Mechanical, thermal, physical, morphological, and flame retardant properties were investigated with several characterization methods. The study aims to meet R22 requirements based on the EN45545 standard for fire protection of railway vehicles, according to which limiting oxygen index (LOI), smoke density, and conventional index of toxicity (CIT) values under HL3 hazard levels have to be min 32%, max 300, and max 1.5, respectively. 15FR-2MH, 15FR-5MH, 15FR-1MH-1ZB, 15FR-1MH-1BOH, and 15FR-1MH-1SIL composites exhibited both the required smoke density, CIT, and LOI values for R22. It can be said that hybrid synergists provide all requirements according to the R22-EN45545 standard. Instead of using 15FR-2MH, 15FR-1MH-1BOH led to a lower smoke density value for PA6.

No abstract

Origanum onites L. (oregano) is an aromatic plant used in medicine, cosmetics and different industrial fields. It includes essential oil and is extensively cultivated as aromatic plant in the world. Therefore, it is also preferred as a spice in foods. Terpene synthase-6 (TPS-6) is an enzyme responsible for synthesis of sesqui-terpenes in aromatic plants. The investigation of gene sequence information and expression characteristics of this enzyme in O. onites may contribute to increase of synthesis of terpenes as raw materials in medicine and cosmetic etc. industry. In this study, partial cloning and sequencing of the TPS-6 gene in the O. onites was aimed. Total RNA isolation from O. onites was performed with TRI Reagent solution. The mRNAs were transformed to cDNAs by Revers Transcription Method. The middle region of TPS-6 gene was amplified by PCR method using degenerative primers designed for TPS-6. Amplified DNA fragments were obtained at 481bp. size and ligated to PGEM T Easy plasmid vector with T4 DNA ligase. The recombinant plasmid vector was transferred to the XL1-Blue host cells (E. coli) and the cloned DNA was sequenced. The partial TPS-6 DNA sequence was confirmed in NCBI GenBank database and registered with an accession number (MF983853). The obtained DNA sequence was analyzed with InterProScan and Clustal Omega software in EBI database. The analysis results showed that this DNA sequence has a specific motif (DXXD) for TPS-6 catalyzing cyclization reactions. The phylogenetic dendrogram was drawn for comparison with other plant TPS-6 genes. O. onites TPS-6 sequence was determined to be very close to O. vulgare TPS-6 on the dendrogram than other plant TPS-6s. The obtained gene sequence information will guide biotechnological researches in the productivity increase of this gene using expression analysis.

Bu araştırmada, sosyal bilgiler öğretiminde coğrafya disiplininin yeri ve önemi hakkında sosyal bilgiler öğretmenlerinin algı ve deneyimlerini ayrıntılı biçimde ele almak amaçlanmıştır. Nitel araştırma yöntemlerinden fenomenoloji deseninin benimsendiği araştırmanın çalışma grubunu Gaziantep ilinde kamuya bağlı okullarda görev yapan 10 sosyal bilgiler öğretmeni oluşturmaktadır. Uzman görüşleri doğrultusunda coğrafyanın sosyal bilgiler öğretimindeki işlevi, sosyal bilgiler konuları içerisinde coğrafyanın yeri ve önemi, sosyal bilgiler öğretiminde yer alan coğrafya konularının öğretme-öğrenme süreci ve 2018 sosyal bilgiler öğretim programında yapılan değişikliklerin coğrafya disiplinine yansımaları gibi çeşitli değişkenler dikkate alınarak yarı yapılandırılmış görüşme formu oluşturulmuştur. Elde edilen veriler fenomenolojik analize tabi tutulmuştur. Araştırma sonuçlarına göre sosyal bilgiler öğretmenleri; 2018 öğretim programında coğrafya disiplini bağlamında yapılan değişiklikleri olumlu bulmuşlardır. Coğrafya konularının öğretiminde görsellerin ve öğrenci merkezli etkinliklerin daha fazla kullanılması gerektiğini belirtmişlerdir. Buna ek olarak ortaokul düzeyinde coğrafyanın ayrı bir ders olarak okutulması gerektiğini beyan etmişlerdir.

This paper focuses on a series of activities for students at middle school to college level, designed to instill a sound understanding of fluids and the properties of fluids. The first activities investigate diffusion and molecular size and these are followed by tasks exploring viscosity and the factors effecting viscosity. Following this, there is an activity about laminar and turbulent flows, and finally there is a visually attractive and colorful activity using the base knowledge about fluids gained from the previous three activities. The main idea of this series of activities is to use the 'predict-observe-explain' strategy and to make use of explanations, from those that are very simple to complex phenomenon. The four activities require students to discuss the subjects, lead by provoking questions,and then make use of argumentation patterns in the final activity, where answers require claims, evidence, warrants, qualifiers and rebuttals.