74 research outputs found
Recycling of Red Mud as a Building Material via a Stabilization/Solidification Method
This study examines stabilization/solidification techniques for red mud/cement systems that involve the production of construction products while minimizing contamination and recycling the red mud. In these techniques, the polluted components of red mud are fixed in a cement body via adsorption and confinement mechanisms and thus, the possible impact of these pollutants on the environment is minimized. In the first step of this study, the physical, chemical, radioactive and mineralogical properties of the material used were determined. Second, red mud was used to replace portland cement in the following proportions: 0, 5, 10, 15, 20, 25, 30, 40 and 50 % of portland cement by weight. Finally, the usability of red mud as a construction product and the environmental effects of such usage were determined.TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [108Y233]This paper was developed under the support of the project TUBITAK, 108Y233. The investigation of the use of building materials with the aim of disposing of different ash and mud samples
Production of Polyvinylpyrrolidone Nanowebs Containing Zinc Cyclohexane Mono Carboxylate via Electrospinning and Investigation of Antibacterial Efficiency
In this study, after the synthesis of zinc cyclohexane mono carboxylate, its chemical structure was analysed with FTIR and TGA. Then electrospun polyvinylpyrrolidone nanofibres containing zinc cyclohexane mono carboxylate were produced and antibacterial properties of the nanowebs obtained were investigated for their use in the textile field. When the FTIR results of the nanofibres containing different concentrations of zinc cyclohexane monocarbocylate are examined, an -OH peak similar to that of PVP fibres is noticed. These results clearly indicate that zinc cyclohexane monocarboxylate is included in PVP. When the TGA spectra of CHMCZn doped nanofibres at different ratios are examined, it is seen that they give more similar results than polyvinylprolidone nanofibres alone. According to the SEM-EDX analyses, it was observed that the fibre diameters obtained were in the range of 145-947 nm. On the other hand, antimicrobial activity against B. subtilis, S. aureus and E. coli strains was detected, regardless of the CHMCZn concentration
Tourmaline nanoparticles doped polyvinylidene fluoride (PVDF) nanofibers
The aim of this work is to produce tourmaline (TM) doped polyvinylidene fluoride (PVDF) nano-composite fibers. TM-containing PVDF nanofibers were produced via a horizontally located electrospinning unit. N,N-dimethylformamide (DMF) and acetone were used as solvents. The amount of PVDF or PVDF/TM in the polymer solution was 20 wt.%. PVDF was dissolved in DMF in presence of heat by using a magnetic stirrer while TM powder was dispersed in Acetone in absence of heat by using an ultrasonic stirrer. These two solutions were then mixed for TM/PVDF nanocomposite fiber production. Pristine PVDF nanofibers were also electrospun as control samples. Produced nano-surfaces were analyzed under scanning electron microscopy (SEM), Fourier-transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD). Voltage generation capacities were investigated by recording the voltage outputs of samples under an applied rotational impact. The peak voltage produced by the TM doped PVDF nanocomposite fibers was higher than the PVDF nanofibers. © 2019, Kauno Technologijos Universitetas. All rights reserved.NKUBAP.06This work was supported by Scientific Research Projects Coordination Unit of Tekirdag Namik Kemal University. “Project number NKUBAP.06.GA.17.093
An in-depth study of the biology, trophic ecology and catchability of the invasive pufferfish Lagocephalus sceleratus from southern Turkey, eastern Mediterranean Sea
The silver-cheeked toadfish (Lagocephalus sceleratus) is an invasive species of highest concern. Its population must be controlled to mitigate its negative impacts on marine ecosystems, fishers, fisheries and human health. This study thoroughly investigates the biology, diet and catchability of the L. sceleratus stock from Finike, Turkey from March 2017 to February 2018 in order to better manage its invasion. A total of 751 specimens were sampled for this study with a M/F ratio of 1.25/1. The species becomes sexually mature at three and a half years of age, and Lm50 was 41.39 cm for males and 42.08 cm for females. Its spawning season in this region was from June to August, peaking in July. Its diet was mostly crustaceans in spring, fish in summer and both fish and crustaceans in winter. This species consumed a large amount of other pufferfish species, resulting in over a quarter of its fish diet. The trophic level of L. sceleratus was 4.41, demonstrating that it is indeed a top predator carnivore in the eastern Mediterranean Sea. Ingested fishing gear parts such as net pieces and hooks were found in about 10% of the fish. A slight modification of longlines using steel branch lines and a swivel hook resulted in double the catch per unit effort than standard longlines, so this technique can be used to target and control more of this invasive species, which is a national priority.El pez globo (Lagocephalus sceleratus) es una especie invasora de gran preocupación. Es necesario controlar su población para mitigar sus impactos nocivos en los ecosistemas marinos, los pescadores, la pesca y la salud humana. Este estudio investiga minuciosamente la biología, la dieta y la capturabilidad del stock de L. sceleratus en Finike, Turquía, desde marzo de 2017 hasta febrero de 2018, con el fin de mejorar la gestión de la invasión. Se muestreó un total de 751 ejemplares para este estudio, con una proporción de machos/hembras de 1,25/1. L. sceleratus alcanza la madurez sexual a los tres años y medio de edad, y la Lm50 fue de 41,39 cm para los machos y 42,08 cm para las hembras. Su temporada de desove en esta región fue de junio a agosto, alcanzando su punto máximo en julio. Su dieta consistía principalmente en crustáceos en primavera, peces en verano y tanto peces como crustáceos en invierno. Esta especie consumía una gran cantidad de otras especies de peces globo, lo que representaba más de una cuarta parte de su dieta de peces. El nivel trófico de L. sceleratus fue de 4,41, lo que demuestra que L. sceleratus es en efecto un carnívoro depredador de alto nivel en el Mar Mediterráneo Oriental. Se encontró ingestión de partes de artes de pesca en aproximadamente el 10% de los peces, como trozos de redes y anzuelos. Una ligera modificación del palangre utilizando líneas de acero y un anzuelo giratorio resultó en valores duplicados de CPUE en comparación con palangres estándar, lo que se puede utilizar para enfocar y controlar más de esta especie invasora, lo cual es una prioridad nacional
Elektro Lif çekim Yöntemi ıle Piezoelektrik Nanolif üretimi Ve Karakterizasyonu
NKUBAP.06.GA.17.093 nolu proje kapsamında gerçekleştirilmiş olan bu çalışmada PVDF polimeri turmalin nano kristalleri ile katkılandırılmıştır. Burada amaç, turmalin kristalinin PVDF polimerinin piezoelektrik özelliği üzerinde bir artışa neden olup olmadığını incelemektir. Bu nedenle turmalin katkılandırılmış PVDF polimerinin uygun çözücülerde çözdürülmesi sonucunda elde edilen polimer çözeltisi elektro lif çekim ünitesine beslenerek nano lif üretimi gerçekleştirilmiştir. Gerek çözelti hazırlanması sırasında kullanılacak çözücü cinsi ve miktarı gerekse elektro lif çekim esnasında uygulanacak besleme hızı, gerilim miktarı, iğne-toplayıcı arası mesafe gibi lif çekim ünitesi parametreleri, literatürün de yardımıyla denenerek tespit edilmiştir. Yapılan çalışmalar neticesinde en uygun parametreler belirlenerek üretimler bu doğrultuda gerçekleştirilmiştir. Bu proje kapsamında, PVDF homopolimeri ve farklı oranlarda turmalin nano kristalleri ile katkılandırılmış PVDF polimerleri DMF, DMAC, Aseton gibi çözücüler yardımıyla çözündürülmüştür. Hazırlanan polimer çözeltileri elektro lif çekim ünitesinden çekilerek nano yüzeyler elde edilmiştir. Üretilen nano yüzeyler SEM, FTIR ile analiz edilmiş ve aynı zamanda voltaj üretim kapasiteleri incelenmiştir. Hazırlanan numunelerin voltaj çıktıları osiloskop ile değerlendirildiIn this work, which was carried out within the scope of NKUBAP.06.GA.17.093 project, PVDF polymer was compounded with tourmaline nanocrystals. The aim of this work is to investigate whether tourmaline crystals cause an increase in the piezoelectric properties of PVDF. For this reason, nanofiber production was carried out by feeding the polymer solution, which was obtained by dissolving tourmaline-added PVDF polymer in suitable solvents, into the electrospining unit. The type and the amount of solvent to be used during the preparation of the polymer solution, electrospinnig parameters such as the feed rate, the amount of applied voltage and the distance between the needle and the collector were tried and determined with the help of literature. The most suitable parameters were determined as a result of trials and the productions were realized in this direction. Within this project, PVDF homopolymer and PVDF polymers compounded with tourmaline nanocrystals at different ratios were dissolved by the help of solvents such as DMF, DMAC, Acetone. The prepared polymer solutions were withdrawn from the electrospinning unit to obtain nano-surfaces. The produced nano-surfaces were analyzed with SEM, FTIR and their voltage generation capacities were investigated. Voltage outputs of the prepared samples were evaluated by using an oscilloscope
Synthesis and characterization of Fe3O4@Cs@Ag nanocomposite and its use in the production of magnetic and antibacterial nanofibrous membranes
Electrospinning is a promising technique to produce polymeric as well as metal oxide nanofibers in diverse domains. In this work, different weight ratios (5%, 7.5% and 10%) of Fe3O4@Cs@Ag magnetic nanoparticles were added in PVP (polyvinylpyrrolidone) polymer and fabricated via electrospinning method to produce magnetic nanofibers (MNFs). Structural, magnetic, morphological, spectroscopic and thermal properties of produced nanofibers were characterized. Furtheremore, antibacterial effects of Fe3O4@Cs@Ag nanofibrous membrane was investigated. Obtained SEM images showed that produced nanofibers were uniform and defect free. Moreover, crystallinity and magnetic moment of fibers was tested by using X-ray diffraction and a vibrating sample magnetometer. The results showed that produced nanofibrous membranes exhibited good antibacterial activity versus Staphylococcus aureus, Bacillus subtilis, Enterococcus faecalis, Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa. © 2020National Science Foundation, NSF; Directorate for Mathematical and Physical Sciences, MPS: 1726617This work was supported in part by Scientific Research Unit of Nam?k Kemal University within NKUBAP.06.GA.19.195 coded project. Magnetic Characterization at Virginia Commonwealth University was partially supported by National Science Foundation, Award Number: 1726617.This work was supported in part by Scientific Research Unit of Namık Kemal University within NKUBAP.06.GA.19.195 coded project. Magnetic Characterization at Virginia Commonwealth University was partially supported by National Science Foundation , Award Number: 1726617
Quantitative evaluation of ischemic myocardial scar tissue by unenhanced T1 mapping using 3.0 Tesla MR scanner
PURPOSEWe aimed to use a noninvasive method for quantifying T1 values of chronic myocardial infarction scar by cardiac magnetic resonance imaging (MRI), and determine its diagnostic performance.MATERIALS AND METHODSWe performed cardiac MRI on 29 consecutive patients with known coronary artery disease (CAD) on 3.0 Tesla MRI scanner. An unenhanced T1 mapping technique was used to calculate T1 relaxation time of myocardial scar tissue, and its diagnostic performance was evaluated. Chronic scar tissue was identified by delayed contrast-enhancement (DE) MRI and T2-weighted images. Sensitivity, specificity, and accuracy values were calculated for T1 mapping using DE images as the gold standard.RESULTSFour hundred and forty-two segments were analyzed in 26 patients. While myocardial chronic scar was demonstrated in 45 segments on DE images, T1 mapping MRI showed a chronic scar area in 54 segments. T1 relaxation time was higher in chronic scar tissue, compared with remote areas (1314±98 ms vs. 1099±90 ms, P < 0.001). Therefore, increased T1 values were shown in areas of myocardium colocalized with areas of DE and normal signal on T2-weighted images. There was a significant correlation between T1 mapping and DE images in evaluation of myocardial wall injury extent (P < 0.05). We calculated sensitivity, specificity, and accuracy as 95.5%, 97%, and 96%, respectively.CONCLUSIONThe results of the present study reveal that T1 mapping MRI combined with T2-weighted images might be a feasible imaging modality for detecting chronic myocardial infarction scar tissue
Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries
Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely
The synthesis of cyclo hexane carboxylate and abietate with some heavy metals and investigation of their properties
Bu çalışmada belli bir metotla NaOH'in hem siklo hekzan karboksilik asit ile hemde abietik asit ile reaksiyonu sonucu sodyum naftenat elde edilmiştir. Daha sonra bu sodyum naftenat ağır metal tuzları ile reaksiyona sokularak metal (Cu2+, Cd2+, Co2+ ve Zn2+) naftenatlar elde edilmiştir. Metal naftenat sentezlerinde kullanılan metotlar şunlardır; 1) Naftenik asitlerin NaOH ile reaksiyonu 2) Sodyum naftenatların ağır metal tuzları ile etkileşimi 3) Bakır abietatı elde ederken pH'a göre paylaşma sabiti ve ekstraksiyon yüzdesi ile değişimlerinin bulunması Bakır naftenatların optimal sentezi, tek basamaklı yerdeğiştirme reaksiyonu ile gerçekleşmiştir. Yapılan çalışmada optimum pH 7 civarında bulunmuştur. Bu yöntemden faydalanarak Cd, Zn, Cu abietat, Zn, Cd, Cu siklo hekzan monokarboksilat, Cd siklo hekzan dikarboksilat elde edilmiştir. Bu elde edilen bileşiklerin 1HNMR , IR, ESR ve UV ile yapıları aydınlatılmıştır Anahtar sözcükler: Karboksilli Asitler, Ekstraksiyon Yüzdesi, Paylaşma Sabiti, Abietik Asit, Metal NaftenatIn this study sodium naphtenate had been obtained by using of specific method during reaction of NaOH with both cycle hexane carboxylic acids and abietic acid. After that, metal (Cu2+, Cd2+, Co2+ and Zn2) naphtenate had been obtained by a reaction of sodium naphtenate with heavy metal salts. The using methods in metal naphtenate synthesis are; 1) The reaction of naphtenic acids with NaOH 2) The interaction of sodium naphtenate with heavy metal salts 3) Fixing of variation with sharing constant and extraction percentage according to PH during derivation of cupper abietate The optimal synthesis of cupper naphtenate had been occurred by a one interchanging reaction. Optimum pH had been found around 7 with this study. Cd, Zn, Cu abietate, Zn, Cd, Cu cyclohexane monocarboxylate, Cd cyclohexane dicarboxylate had been obtained by using of these methods. The structure of obtained compound had been analyzed with 1H-NMR , IR, ESR ve UV. Key words: Carboxylic Acids, Sharing Constant, Extraction Percentage, Abietic Acid, Metal Naphtenat
Kuantum noktaların kuantum Monte Carlo incelemeleri
Bu tezde, iki boyutlu (2D) disk benzeri ve üç boyutlu (3D) küresel parabolik kuantum noktalarda kuşatılan etkileşen iki elektron ve elektron-deşik çiftinin (ekziton) taban durum enerjilerini hesaplamak amacıyla Varyasyonel Monte Carlo (VMC) ve Monte Carlo Diagonalizasyon (MCD) yöntemleri uygulandı. Boyut ve kuantum kuşatmanın, parabolik kuantum noktalarda etkileşimli elektron-deşik çiftinin taban durumu ve bağlanma enerjileri üzerindeki etkileri incelendi. Ayrıca, parabolik kuşatma potansiyeli ve ektin kütle yaklaşımı dahilinde kuantum noktaların büyüklük ve şeklinin iki elektron üzerindeki etkileri araştırıldı. Monte Carlo Diagonalizasyon metodu ile harmonik-osilatör bazı ile Hylleraas-benzeri koordinatlar cinsinden oluşturulan korelasyon fonksiyonun çarpımı şeklinde önerilen deneme dalga fonksiyonunun, parabolik kuantum noktalarda etkileşen parçacıkların incelenmesinde güçlü bir çözüm tekniği oluşturduğunu ortaya koymaktadır. In this thesis, we have applied both the Variational Monte Carlo (VMC) and Monte Carlo Diagonalization (MCD) techniques for calculation the ground-state energies of correlated electron-hole pair (exciton) and interacting two electrons confined in a two dimensional (2D) disc-like and three dimensional (3D) spherical parabolic quantum dots. The effects of dimensionality and quantum confinement on the ground state as well as binding energies of a correlated electron-hole pair in parabolic quantum dots have been investigated. Moreover, under parabolic confinement potential and within effective mass approximation size and shape effects of quantum dots on the ground state energy of two electrons have been studied. This study indicates that Monte Carlo Diagonalization technique combined with the trial wave function proposed as the harmonic-oscillator basis multiplied by correlation part in terms of Hylleraas-like coordinates are a powerful tool for studying interacting particles in parabolic quantum dots
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