Click Reactivity of Azide-Modified Polyvinyl Chloride as an Entry to Glycopolymer Scaffolds

We report the synthesis of new carbohydrate/triazole polymers based on poly(viny chloride) (PVC). Azide incorporation into commercially available PVC was carried out using nucleophilic substitution and Cu-catalyzed reaction of the resulting PVC-N3 using three alkynyl-containing acetonide-protected monosaccharides (based on D-glucose and D-galactose) provided a set of PVC-based polymers incorporating a triazolyl linkage with monosaccharide moieties present on the periphery. Modified polymers were characterized by using Fourier transform infrared (FT-IR), Nuclear Magnetic Resonance (1H-NMR and 13C-NMR) spectroscopy, together with thermogravimetric and surface morphological analysis

An Improved Pulse Density Modulation Control for A Semi Active Rectifier in Wireless Power Transfer with LC/S Compensation

This paper proposes an improved pulse density modulation (PDM) control for a semi active rectifier (SAR) in wireless power transfer (WPT) with LC/S compensation. In order to improve the output regulation performance of the WPT converter, an improved pulse density modulation (PDM) is used, and its control signals are applied to the switches of the SAR. Based on the improved PDM control, the pulse sequence of the SAR is distributed more evenly compared to the traditional PDM. Thus, the output voltage ripple of the WPT converter is decreased and the output current ripple of the high frequency inverter (HFI) is decreased as well. The soft switching conditions can be achieved for both the SAR and HFI switches. In addition, since the control is applied only to the receiving side, there is no necessary for the communication devices. A simulation study is carried out to verify the performance of the improved PDM control and compared with the traditional PDM control. Based on the simulation results, the ripples of the output voltage as well as the output current ripples of the HFI are effectively reduced by using the improved PDM. Finally, the experimental results are presented to validate the effectiveness of the proposed control method

METİLEN MAVİSİ VE ALİZARİN’İN LÜMİNESANS SPEKTROMETRESİ İLE ASİTLİK SABİTLERİNİN TAYİNİ VE BAZI METAL DUYARLILIKLARININ İNCELENMESİ

Organik boyar maddeler endüstride renklendirme amaçlı kullanılmalarının yanı sıra indikatör ve/veya sensör olarak da kullanılabilen önemli hammaddelerdir. Birçoğu metal ve proton iyonlarına duyarlı olduğunda indikatör özelliği kazanır. Ayrıca metal iyonlarına karşı aktif olan birçok boya da sensör kabiliyeti sergilemektedir. Bu araştırmada, Metilen mavisi ve Alizarin boyar maddelerinin sulu çözeltilerinin çalışma pH aralıkları ile asitlik sabitlerinin (pKa) hesaplanması ve metal duyarlılıklarının incelenmesi üzerinde çalışılmıştır. Bu amaçla, Luminesans Spektrometre cihazıyla her iki boyar maddenin de taze hazırlanmış 10-3M’ lık sulu çözeltilerinde uyarma ve emisyon spektrumları ayrı ayrı alınmıştır. Emisyon spektrumlarından faydalanılarak Metilen mavisi ve Alizarin’ in çalışma pH aralıklarının sırasıyla 2-6 ve 2-9 olduğu tespit edilmiştir. Yapılan hesaplamalardan Metilen mavisi için pKa değeri 4,97 olarak bulunurken Alizarin için bu değer 3,70 olarak hesaplanmıştır. İlaveten Metilen mavisi’ nin IB ve IIB grubu-d blok geçiş elementlerinin iyonları olan Cu2+ ve Zn2+ iyonları ile kompleks yapabildikleri gözlenmiştir. Benzer biçimde, Alizarin’ in 3A grubu ve IB ile VIIIB grubu-d blok geçiş elementlerinin iyonları olan Al3+, Cu2+, Co2+, Ni2+ iyonları ile kompleksleşebildiği tespit edilmiştir.

Nitrite in Nature: Determination with Polymeric Materials

Nitrogen compounds being important for the vital activities of living things are produced by the nitrification process and occurred spontaneously in the nitrogen cycle. Human vital activities are also responsible for the extra nitrogen released into the atmosphere. So, both human and environmental healths are negatively affected by the increasing nitrate and nitrate amounts in water and soil. For this reason, it is aimed to ensure regular control of nitrates and nitrites at certain levels in order to protect the universe and all living things. Their precise and selective determination by various methods is very important. Their determinations can usually be made by using electrochemical, spectrophotometric, chromatographic and titrimetric methods. Nowadays instead of these techniques, sensors are preferred in determining nitrate and nitrite due to their easy, fast, selective and sensitive application properties. Furthermore, polymeric materials have shown great promise for different sensing applications such as gas, humidity, explosive and water pollutants. Sensors, which are developed by polymerization, have very high quality for the determination of nitrite. The highly sensitive results of optical and electrochemical sensors attract the attention of researchers. In this review, different detection methods for nitrite ions and various studies on the preparation of polymeric sensors that can selectively capture the nitrite ions in complex matrices are examined

An Efficient Wireless Power Transfer System for An Implantable Deep Brain Stimulation

This paper presents an efficient wireless power transfer (WPT) system for implantable deep brain stimulation (DBS) devices. A head-mounted DBS device is taken into account in the design procedure of the presented WPT system. A three coil system is designed to provide high efficiency power transfer. The LCC compensation network which has constant voltage characteristic is used in the transmitter side and two receiver coils using series compensation are located in the receiver side, into the human tissue. Finally, performance of the proposed WPT system is tested by a 3D electromagnetic simulation work at a 10 mm distance. Based on the simulation results, 1.19 V DC output voltage is regulated while the DC output current is 24 mA. The power transfer efficiency is achieved as 4.63% at full load condition

MENGIDENTIFIKASI SIKAP PENDIDIKAN KARAKTER MENGHARGAI PRESTASI TERHADAP SISWA KELAS VIII SMP N 18 KOTA JAMBI

Penelitian ini bertujuan untuk untuk mengetahui bagaimana sikap siswaSMPNEGERI 18 Kota Jambi terhadap Pendidikan Karakter menghargai prestasi. Jenis penelitian ini adalah Deskriptif Statistik, yaitu berupa penggunaan lembar angket berisi pernyataan - pernyataan. Populasi penelitian meliputi kelasVII, VIII, dan IX SMPN 18 Kota Jambi, dengan jumlah keseluruhan  720 siswa. Sampel untuk penelitian menggunakan kelas VIII E dan VIII F, dengan jumlah masing – masing kelas 32 siswa dan 28 siswa. Teknik dalam pengambilan data penelitian dengan cara membagikan lembar angket berisi pernyataan kepada tiap siswa, yang disertai tanggapan-tanggapan yang harus dipilih siswa. Data hasil penelitian yang diperoleh menyatakan bahwa, bahwa siswa kelas VIII E telah memiliki karakter yang baik dalam menghargai prestasi. Sedangkan untuk siswa kelas VIII F, telah memiliki karakter yang sangat baik dalam menghargai prestasi. Dikarenakan pentingnya penerapan pendidikan karakter pada siswa pada setiap jenjang pendidikan. Oleh karena itu, sangat diharapkan adanya peningkatan kesadaran siswa dalam menghargai prestasi. 

Triangle inequality concept teaching: The theory of didactic situations case

The purpose of this study is to implement an a-didactical activity relating to the acquisition of the triangle inequality, prepared within the framework of the Didactic Situations Theory (TDS), and to report the experiences of the students during the implementation process. The study employs a case study method based on a qualitative approach. Six seventh-grade students in a middle-low socioeconomic secondary school in the Marmara Region of Türkiye participated in the study. The researchers prepared an a-didactical activity in which students discovered triangle inequality. Data were collected through observation, video recording, and worksheets. A descriptive analysis was performed on the data obtained. As a result of the analysis, it was concluded that students completed the activity with the correct expressions by experiencing different phases of the a-didactical situation

CARBOHYDRATE RESEARCH

The synthesis of 5-amino-5-deoxy-1,2-O-(S)-trichloroethylidene-beta-L-arabinofuranose and 6-amino-6-deoxy-1,2-O-(S)-trichloroethylidene-alpha-D-glucofuranose is described by a simple three- or four-step route. Antibacterial potency of the new compounds was determined using an inhibition zone diameter test. The results show that these compounds have a broad-spectrum activity against Gram-positive, Gram-negative bacteria and Candida albicans. (C) 2010 Elsevier Ltd. All rights reserved

An Improved Pulse Density Modulation Control for A Semi Active Rectifier in Wireless Power Transfer with LC/S Compensation

This paper proposes an improved pulse density modulation (PDM) control for a semi active rectifier (SAR) in wireless power transfer (WPT) with LC/S compensation. In order to improve the output regulation performance of the WPT converter, an improved pulse density modulation (PDM) is used, and its control signals are applied to the switches of the SAR. Based on the improved PDM control, the pulse sequence of the SAR is distributed more evenly compared to the traditional PDM. Thus, the output voltage ripple of the WPT converter is decreased and the output current ripple of the high frequency inverter (HFI) is decreased as well. The soft switching conditions can be achieved for both the SAR and HFI switches. In addition, since the control is applied only to the receiving side, there is no necessary for the communication devices. A simulation study is carried out to verify the performance of the improved PDM control and compared with the traditional PDM control. Based on the simulation results, the ripples of the output voltage as well as the output current ripples of the HFI are effectively reduced by using the improved PDM. Finally, the experimental results are presented to validate the effectiveness of the proposed control method

FRESENIUS ENVIRONMENTAL BULLETIN

Arum Italicum Mill. fruits that have antioxidant effect and some phenolic compounds were investigated at its different maturation stages. Observing of some phenolic compounds like ellagic acid, hesperidin, resveratrol and quercetin varied from depending on their ripening stages in harvest as immature, half mature and mature crops. These compounds can be recovered from Arum Italicum Mill. fruits by using the Soxhlet extraction method in methanol for four hours. And, the phenolic compounds in these fruits can easily be identified by using HPLC-DAD device. It is obvious that the amounts of ellagic acid, hesperidin, resveratrol and quercetin in half-mature fruits of Arum Italicum Mill. decrease and even hesperidin, resveratrol and quercetin disappear altogether. While the antioxidant effect was determined by using DPPH and TEAC, the total phenolic compounds of the fruits in all harvest periods were defined by using standards such as gallic acid and catechin