Copolymerization of 4-Acetylphenyl Methacrylate with Ethyl Methacrylate: Synthesis, Characterization, Monomer Reactivity Ratios, and Thermal Properties

Methacrylates have high glass transition temperature (Tg) values and high thermal stability. A new methacrylate copolymer, poly(4-acetylphenyl methacrylate-co-ethyl methacrylate) (APMA-co-EMA), was synthesized. The thermal behaviors of copolymers were investigated by differential scanning calorimetry and thermogravimetric analysis. They behaved as new single polymers with single Tg’s and the thermal stability of the copolymers increased with increasing 4-acetylphenyl methacrylate (APMA) fraction, leading to the manufacture of copolymers with desired Tg values. Structure and composition of copolymers for a wide range of monomer feed ratios were determined by Fourier transform infrared (FT-IR) and 1H-nuclear magnetic resonance (1H-NMR) spectroscopic techniques. Copolymerization reactions were continued up to 40% conversions. The monomer reactivity ratios for copolymer system were determined by the Kelen-Tüdös (ra(APMA)=0.81; rb(EMA)=0.61) and extended Kelen-Tüdös (ra=0.77; rb=0.54) methods and a nonlinear least squares (ra=0.74; rb=0.49) method

MENTAL MODELS OF PRE-SERVICE SCIENCE TEACHERS ABOUT BASIC CONCEPTS IN CHEMISTRY

The aim of this study was to investigate mental models of pre-service science teachers about basic concepts in chemistry. Cross-sectional research design was used in this study. The sample of the study consisted of 60 pre-service science teachers which were 15 freshmen, 15 sophomores, 16 junior, 14 senior. The drawings and the writing of the students about the basic concepts of chemistry, which we have asked to the participants as 5 open-ended questions, composed of the research data. The students are asked to answer these open-ended questions on the first page, and they were asked to draw their imaginations about the questions on the second page so that their mental images can be learned about these concepts of chemistry. Responses of questions and the students' mental models were compared with scientific answers/models, and were evaluated under five categories which were 'there is no drawing/expression', 'wrong or irrelevant drawing/ expression of question', 'partially correct drawing/ expression', 'the drawing/ expression that has some deficiencies', 'completely correct and complete drawing/ expression'. Tables including frequency were used analysis of data. The results of study indicated that relationship between levels of writing and drawings were interpreted according to class leve

Copolymerization of 4-Acetylphenyl Methacrylate with Ethyl Methacrylate: Synthesis, Characterization, Monomer Reactivity Ratios, and Thermal Properties

Methacrylates have high glass transition temperature ( ) values and high thermal stability. A new methacrylate copolymer, poly(4-acetylphenyl methacrylate-co-ethyl methacrylate) (APMA-co-EMA), was synthesized. The thermal behaviors of copolymers were investigated by differential scanning calorimetry and thermogravimetric analysis. They behaved as new single polymers with single 's and the thermal stability of the copolymers increased with increasing 4-acetylphenyl methacrylate (APMA) fraction, leading to the manufacture of copolymers with desired values. Structure and composition of copolymers for a wide range of monomer feed ratios were determined by Fourier transform infrared (FT-IR) and 1 H-nuclear magnetic resonance ( 1 H-NMR) spectroscopic techniques. Copolymerization reactions were continued up to 40% conversions. The monomer reactivity ratios for copolymer system were determined by the Kelen-Tüdös ( (APMA) = 0.81; (EMA) = 0.61) and extended Kelen-Tüdös ( = 0.77; = 0.54) methods and a nonlinear least squares ( = 0.74; = 0.49) method

The effect of popular science sites on the perception of science concepts

Bu çalışmanın amacı, popüler bilim siteleri kullanılarak yapılan öğretimle öğretmen adaylarının günlük hayattaki fen kavramlarına yönelik algılarının nasıl geliştiğini değerlendirmektir. Çalışmada karma yöntem içerisinde incelenen müdahale deseni kullanılmıştır. Çalışmanın örneklemi fen bilgisi öğretmenliği 3. Sınıfta öğrenim gören 62 öğretmen adayından oluşmaktadır. Popüler bilim siteleri ile öğretim için sindirim ve boşaltım, fotosentez, maddenin yapısı, solunum, yakıcı-yanıcı-söndürücü madde, paslanma ve kaynama konularında popüler bilim sitelerinden eğitsel içerikler toplanmıştır. Bu içerikler bilim teknik ve popüler bilim (popular science) siteleri ile sınırlıdır. Video veya bilimsel anlatımlar ile gündelik yaşam temelli örnekler içeren eğitsel içerikler uzman görüşü alınarak belirlenmiştir. Veri toplama aracı olarak açık uçlu sorular ve çalışma yaprakları hazırlanarak yedi hafta süren uygulama tasarlanmıştır. Açık uçlu sorulardan ve çalışma yapraklarından elde edilen veriler ayrı ayrı analiz edilip, birleştirilerek yorumlanmıştır. Elde edilen bulgulara göre, eğitim öncesinde çalışma yapraklarından belirlenen safra kesesinin görevi, yaprakların sonbaharda sararmasının nedeni gibi konulardaki yanılgılarının birçoğunun giderildiği ortaya çıkmıştır.The aim of this study was to evaluate how teacher candidates' perceptions of science concepts in daily life have improved by teaching using popular science sites. The intervention design examined in the mixed method was used in the study. The sample of the study consists of 62 pre-service science teachers who are junior. Educational contents were collected from popular science sites with popular science sites for digestion and excretion, photosynthesis, structure of matter, respiration, burning-flammable-extinguishing agent, rust and boiling. These contents are limited to science technical and popular science sites. Educational content including videos or scientific explanations and examples based on daily life were determined by taking the expert opinion. Open-ended questions and worksheets were prepared as a data collection tool and the seven-week application was designed. Data obtained from open-ended questions and worksheets were analyzed separately, combined and interpreted. According to the findings obtained, it was revealed that many of his misconceptions, which was determined from the worksheets before the training, about the task of the gallbladder, the reason why the leaves turned yellow in autumn would extinguish

Design of Blockchain-Based Many-to-Many Anonymous Data Sharing Scheme

Many to many data sharing in the group setting in a cloud environment is a challenging problem that is crucial for numerous schemes. To our best knowledge, there is no generic study to allow sharing of confidential information in many to many pattern between different groups. Thus we propose a novel data sharing scheme enabling many to many sharing of encrypted data between different groups with using cryptographic techniques such as traceable ring signatures, multiple receiver key encapsulation, etc. We give a comprehensive security analysis showing our scheme is indistinguishable under user encapsulation keys and chosen plaintext attack secure under discrete logarithm assumption. We propose the implementation of our scheme, and the experimental results show that the proposed scheme is applicable for decentralized data sharing

PİLONİDAL SİNÜS AMELİYATI SONRASI FARKLI YATIŞ POZİSYONUNUN DRENAJ MİKTARI ÜZERİNE ETKİSİ

Amaç: Bu çalışma pilonidal sinüs ameliyatı sonrası farklı yatış pozisyonunun drenaj miktarı üzerine etkisini belirlemek amacıyla girişimsel olarak yürütüldü. Yöntem: Çalışmanın evrenini Nisan 2014 – Mayıs 2015 tarihleri arasında Kars Harakani Devlet Hastanesi Genel Cerrahi Servisinde pilonidal sinüs ameliyatı planlanan hastalar oluşturdu. Örneklemi ise; belirtilen evrenden olasılıksız rastlantısal örnekleme yöntemi ile araştırmaya alınma kriterlerini taşıyan 60 hasta (30 yüzüstü, 30 sol lateral/yarı sırtüstü yatış grubu) oluşturdu. Veri toplamada hastalar için “Tanıtıcı Özellikler Formu” ve “Pilonidal Sinüs Eksizyonu Postoperatif Drenaj Miktarı Takip Formu” kullanıldı. Verilerin analizinde tanımlayıcı istatistikler, ki-kare (x2 ), Mauchly’s W ve t testi yapıldı. Bulgular: Çalışmada grupların tanıtıcı özellikler yönünden homojen olduğu tespit edildi. Kontrol grubunda ameliyat sonrası yüzüstü pozisyonunda yatırılan hastalarda ortalama 24. saat sonunda 25.16±15.32, 48. saat sonunda 4.80±3.82, 72. saat sonunda 1.03±2.04, toplam 30.96±19.35 olarak bulundu. Deney grubunda ameliyat sonrası sol lateral/yarı sırtüstü pozisyonunda yatırılan hastalarda ortalama 24. saat sonunda 17.76±8.83, 48. saat sonunda 3.26±2.72, 72. saat sonunda 1.10±2.00, toplam 22.13±11.56 olarak saptandı. Sonuç: Çalışma sonucuna göre ameliyat sonrası yüzüstü pozisyonunda yatırılan pilonidal sinüs hastalarının drenaj miktarı sol lateral/yarı sırtüstü pozisyonunda yatan pilonidal sinüs hastalarından daha fazla olduğu görüldü.Aim: This study was conducted interventionally to determine the effect of different lying position on drainage amount after pilonidal sinus surgery. Methods: the study population consisted of patients with pilonidal sinus who were hospitalized in Kars Harakani State Hospital General Surgery Department between April 2014 and May 2015. the sample is; 60 patients (30 prone, 30 left lateral/semi supine hospitalization group) who met the inclusion criteria by random sampling method. “Introductory Features Form” and “Pilonidal Sinus Excision Postoperative Drainage Amount Tracking Form” were used for data collection. Descriptive statistics, chi-square (x2 ), Mauchlys W and t tests were used to analyze the data. Results: in the study, it was determined that the groups were homogeneous. in the control group, 25.16 ± 15.32 at the end of the 24th hour and 4.80 ± 3.82 at the 48th hour and 1.03 ± 2.04 at the 72th hour and 30.96 ± 19.35 at the end of the operation. in the experimental group, 17.76 ± 8.83 at the end of 24 hours, 3.26 ± 2.72 at the 48th hour, 1.10 ± 2.00 at the end of the 72th hour and a total of 22.13 ± 11.56 at the end of the operation. Conclusion: According to the results of the study, the amount of drainage of the pilonidal sinus patients in the postoperative position prone was higher than the pilonidal sinus in the left lateral/semi supine