235 research outputs found
Static and dynamic properties of CN/Cu(001) surfaces and oxidation, dissociation and bimolecular debarboxylation of isocyanate species adsorbed on Cu(001)
No full textThis dissertation presents an outlines my investigations of static and dynamic properties of adsorbed cyanide (CN) and isocyanate (-NCO) species as well as some of their chemistries. Surface bound CN-containing species have not previously been studied extensively, partially due to the inapplicability of fundamental e-beam based surface analysis techniques for investigations. I had the opportunity in my studies to employ multiple surface probing techniques, i.e. HAS, XPS, NEXAFS, TPD and RAIRS, to compile and cross-examine information from CN, –NCO, and derived species, adsorbed on the Cu(001) surface. While angle resolved He atom scattering (HAS) was employed to identify and investigate the ordered superstructure of CN/Cu(001) surfaces, TOF-HAS was employed to investigate its dynamic properties. The CN/Cu(001) surface induced unprecedented simultaneous coherent He diffraction with a large “classical” multiphonon backscattered He intensity. A superstructure is implied that contains both rigidly bound CN species, which maintain the long range c(10x6) translational symmetry, together with bound highly-dynamic CN species that exhibit large thermally induced displacements. The NEXAFS measurements suggest multiple spatial binding configurations for the adsorbed CN moieties. In addition, TPD spectra of C2N2 desorption from CN/Cu(001) surface were analyzed, using my newly developed method, to determine the activation energies for desorption as a function of CN coverage. There are two reactions of NCO species examined in my studies. The first is the newly discovered mutual reaction between NCO species. This type of interaction had not been seen before, as it is essentially difficult to prepare pure NCO/metallic surfaces. Copper was chosen as a substrate as HNCO exposures of Cu(001) at RT, followed by spontaneous H2 desorption, do produce NCO only surfaces. A thermal treatment of the surface, at 573K, leads to a bimolecular decarboxylation of NCO, leaving a carbodimide species (NCN) on the surface. The sp-hybridized linear NCN moieties, which are bound nearly parallel to the substrate, show high thermal stability. The second reaction of NCO, which I have studied, is its oxidation. In particular, the effect of CN coadsorbates on the oxidation of NCO was studied. It was found that the presence of CN catalyzes a dissociation reaction of NCO species on Cu(001).Ph. D.Includes bibliographical referencesby Erkan Ziya Ciftlikl
Effect of size and slenderness on the axial-compressive behavior of basalt FRP-confined predamaged concrete
No full textTo investigate the size and slenderness effect on the axial-compressive behavior of basalt fiber-reinforced polymer (BFRP)-confined predamaged concrete, five groups of concrete cylinders with different sizes and slenderness ratios were designed and tested. The cylinders were axially preloaded to three predamage levels, then repaired using BFRP, and reloaded. The results showed that the concrete predamage had an adverse effect on the ultimate strength and initial elastic modulus of BFRP-confined concrete. Except for the smallest specimens affected by the wall effect, the initial analysis found that the ultimate strength of BFRP-confined concrete decreased with an increase in size and slenderness ratio, and the size and slenderness effect decreased with an increase in BFRP confining pressure, while these increased with the severity of concrete predamage. However, there was no obvious size or slenderness effect on the ultimate strain of BFRP-confined concrete. Through multifactorial analysis, it was confirmed that the ultimate strength of BFRP-confined undamaged and predamaged concrete was influenced by the slenderness. Considering the effect of size, slenderness, and predamage, monotonic and cyclic models were developed for BFRP-confined concrete. Finally, a uniaxial material object was added into OpenSees to provide an effective numerical material model for theoretical analyses and engineering applications. © 2021 American Society of Civil Engineers.The present research was supported by the National Natural Science Foundation of China (Grant No. 51878268) and the Natural Science Foundation of Hunan Province, China (Grant No. 2020JJ4195).
Part of this research was completed by the first author in collaboration with the third and fourth authors during his one-year visit to Ohio State University. The first author acknowledges the State Scholarship Fund of China Scholarship Council (Grant No. 201606135057) for supporting this work and his research visit to the United States
Intranasal budesonide spray as an adjunct to oral antibiotic therapy for acute sinusitis in children
No full textBackground: The role of topical corticosteroids in the treatment of acute sinusitis has not been established in children. Objective: An attempt was made to determine the impact of topical corticosteroids as an adjunct to antibiotic treatment in the management of childhood sinusitis. Methods: In a double-blind, placebo-controlled study. 151 children with sinusitis were recruited from a general pediatric outpatient clinic and 89 completed a 3-week trial. Treatment consisted of amoxicillin-clavulanate potassium, 40 mg/kg/d tid. combined with bid nasal spray of either budesonide, 50 mu g, to each nostril (n = 43) or placebo in = 46) for 3 weeks. Patients maintained daily symptom cards throughout the study and were examined by the same physician each week. Results: Clinical symptoms and signs decreased significantly in both treatment groups in comparison to baseline (P < .01). We detected a significant improvement in the scores of the cough and nasal discharge at the end of second week in the budesonide group when compared with placebo (P < .05). Friedman nonparametric repeated measures ANOVA test revealed a significant decrease in the total weekly scores of cough during the second week of budesonide treatment (P < .001) in contrast to continuous decline during the second and third weeks in the placebo group (P < .001 and P < .05, respectively). While the nasal discharge score decreased significantly during the second week in the budesonide group (P < .01), no significant effect on the nasal discharge score was observed in the placebo group. Conclusion: These data suggest that topical corticosteroids may be a useful ancillary treatment to antibiotics in childhood sinusitis and effective in reducing the cough and nasal discharge earlier in the course of acute sinusitis
A Comparison of the Ballistic Performances of Various Microstructures in Mil-A Armor Steel
No full textKonca, Erkan/0000-0001-8943-091XDue to their advantageous properties, there is a growing interest in developing armor steels containing fully or partially bainitic microstructures. In this study, bainitic and martensitic microstructures were obtained in rolled homogeneous armor (RHA) steel samples and their ballistic protection performances were investigated. RHA (MIL-A-12560) steel samples were subjected to isothermal heat treatments at three different temperatures, where one temperature (360 degrees C) was above the martensite formation start (Ms) temperature of 336 degrees C while the other two (320 degrees C and 270 degrees C) were below. For the assessment of the ballistic protection performance, the kinetic energy losses of the 12.7 mm bullets fired at the test samples were determined. The promising nature of the bainite microstructure was confirmed as the sample isothermally treated at 360 degrees C provided approximately 10% higher ballistic protection as compared to the regular RHA sample of tempered martensite microstructure. However, the ballistic performances of the isothermally treated samples decreased as the treatment temperature went below the Ms temperature. Following the ballistic tests, hardness measurements, impact tests at -40 degrees C, and macro- and microstructural examinations of the samples were performed. No correlation was found between the hardness and impact energies of the samples and their ballistic performances.ROKETSAN Missile Industries Inc. (Ankara, Turkey)This research was funded by ROKETSAN Missile Industries Inc. (Ankara, Turkey). The APC was paid for by the author
Effects of fibre wrapping degree and ratio on the tensile properties of carbon FRP-steel hybrid reinforcements
No full textThe aim of this study is to develop carbon fibre reinforced polymer (CFRP)-steel hybrid reinforcements that are more cost effective than CFRP reinforcements, resistant to external influences, have low creep, high modulus of elasticity, high tensile strength and high ductility. In this context, hybrid reinforcements were produced by winding epoxy impregnated carbon fibre on ribbed steel reinforcements with diameters of 8, 10 and 12 mm at 3 different angles (15, 30 and 45 degrees) and 3 different layer thicknesses (from 1 layer to 3 layers) by filament winding method. In the study, the effect of reinforcement diameter, fibre ratio in the reinforcement (I) and fibre wrapping angle on hybrid reinforcement, yield and tensile stress, modulus of elasticity, energy dissipation capacity and ductility were investigated by tensile tests.As a result of the study, the tensile properties of the reinforcements hybridised by filament winding method improved more than the reinforcements hybridised by other methods (pultrusion, braidtrusion). Modulus of elasticity of the reinforcements developed by this method was 6%-38% higher than the other hybrid reinforcements and the energy dissipation capacity under maximum force was 5%-114% higher. In addition, the fibre ratio between 9% and 32% in specimens with 15 degrees fibre winding angle improved the maximum tensile stress of the steel reinforcement by 3%-35% on average, while the specimens with 30 and 45 degrees FRP winding angle had almost no contribution. It was observed that for the hybrid reinforcement to exhibit very linear behaviour, the fibre ratio (I) should be minimum 0.13 & LE; I and 0.29 & LE; I for the reinforcements with 15 and 30 degrees wrap angle, respectively. The study also includes a theoretical stress-strain model to be in good agreement with the experimental results.Amasya University Scientific Research Project Coordination Unit [FMB-BAP 190429]; Technical Sciences Vocational School, Amasya University; [FMB-BAP 180366]The study was supported by Amasya University Scientific Research Project Coordination Unit under the project numbers FMB-BAP 18-0366 and FMB-BAP 19-0429. This support is gratefully acknowledged. The experiments were conducted in the Structural Material Laboratory of the Technical Sciences Vocational School, Amasya University
Vocabulary in poet-author Nuri Pakdil in the works of the essasy type
No full textSosyal Bilimler Enstitüsü, Türk Dili ve Edebiyatı Ana Bilim Dalı, Yeni Türk Dili Bilim DalıDilimizdeki sözcüklere cümle içinde kullanım şekline göre çok çeşitli anlamlar yüklenebilmektedir. Bu nedenle bir dildeki sözcüklerin sayısının tespiti kadar kelimelerin çok anlamlılığının tespiti de o dilin zenginliğini ortaya koymada gereklidir. Kelimeleri işleyen, onlara yeni anlatım olanakları sağlayanlar ise şair ve yazarlardır. Nuri Pakdil, kendine has üslubu ve sözcük tercihleriyle oldukça dikkate değer bir yazardır. Hakkında yazılı ve görsel alanda pek çok çalışma yapılmakla birlikte eserleri üzerine söz varlığı açısından bir çalışma yapılmamıştır. Çalışmada Nuri Pakdil'in deneme türündeki eserlerinde yer alan söz varlığının ortaya koyulması amaçlanmıştır. Eserlerin bir bölümü deneme/günlük tarzında olduğundan yazarın yaşamına ait bilgiler de içermektedir. Benzer şekilde eserlerin düşünce yazısı olması sebebiyle yazarın dünya görüşü ile edebî ve fikri eleştirileri de bu eserlerde görülmektedir. Yazarın hayatı, edebi şahsiyeti ve eserleri hakkında bilgi verildikten sonra sözcük ve söz varlığı kavramlarına değinilerek, incelenen eserlerde kullanılan dil, temel söz varlığı bağlamında değerlendirilmeye çalışılmıştır. Çalışmada, eserlerdeki kelimelerin kullanım sıklıklarının tasnifi yapılmıştır. Ayrıca incelenen eserlerin dizinleri de toplu olarak çalışmada yer almaktadır.ABSTRACT The words in our language can be loaded with a variety of meanings according to the usage in the sentence. For this reason, the determination of the number of words in a language as well as the determination of the meaning of words is necessary to reveal the richness of the language. Poet sand writers are the ones who process the word sand provide them with new narrative opportunities. Nuri Pakdil is a remarkable writer with her uniquestyle and vocabulary choices. Although there are many written and visual studies about it, there has not been any study in his vocabulary. Nuri Pakdil, who is a very important man of ideas besides the writer-poet-translatoridentity, is very interesting. In our study, it was a imed to reveal the vocabulary of Nuri Pakdil in his essay types. Since some of the worksare in a trial / daystyle, they also contain information about the life of the author. Similarly, the author's world view and his literary and intellectual criticism can be seen due to the fact that the worksare thought texts. After informing the author about the word and vocabulary in the general framework, the language used in the works examined has been tried to be evaluated in the context of the basic vocabulary. The frequency of use of the words in the Works were classified. In addition, the directories of the studied works are also included in our study
High concentration hexavalent chromium removal performance of a sulfidogenic activated carbon-bed bioreactor at moderate temperature
No full textThis study intended to assess the performance of a sulfidogenic activated carbon-bed bioreactor (SACB) receiving high concentrations of hexavalent chromium (Cr6+). SACB was tested for 126 days at moderate temperature (20 degrees C) with a synthetic feed carrying ethanol as carbon source while employing a hydraulic retention time of 24 h. Excellent sulfidogenic performance was obtained during both non-Cr6+ added and 100 mg L-1 Cr6+ added periods. Sulfate reduction and carbon oxidation performances initially were 99% and 93%, respectively, and introduction of 100 mg L-1 Cr6+ to the feed at pH 4.0 resulted in only 3% reduction for both performances. During initial testing period, alkalinity generation was 99% of the theoretically expected value, and effluent pH increased up to 8.2 from pH 6.7. During the Cr6+ fed period, average alkalinity concentration was 2316 mgCaCO3 L-1 while pH increased to 8.2 from pH 4.0 with additional acidity consumption during Cr6+ reduction by the biologically generated sulfide. Effluent Cr6+ concentration remained below 0.5 mg L-1 with an average of 0.13 mg L-1, whereas average total chromium concentration in the effluent remained <= 0.2 mg L-1. Batch studies were carried out to better understand stoichiometry and kinetics of Cr6+ reduction with biogenic sulfide
Self-forming dynamic membrane bioreactor for textile industry wastewater treatment
No full textThe robustness of anaerobic dynamic membrane bioreactor (AnDMBR) for synthetic textile wastewater treatment was investigated. Textile wastewater may contain high concentrations of NaCl and sulfate, hence their impact on the AnDMBR performance was investigated in detail. A dynamic membrane was formed on a 20-μm pore sized nylon support layer at a constant flux of around 8 LMH. In the absence of sulfate addition, total and filtered (soluble) COD averaged 96 ± 49 mg/L (91% removal) and 75 ± 35 mg/L (93% removal), respectively. Sulfate addition increased total COD in the permeate to 222 ± 68 mg/L (79% removal). Average SS concentration was lower than 30 mg/L in the permeate although its concentration in the bioreactor reached 10 g/L. Throughout the AnDMBR operation dye removal averaged >97%. Sludge filterability, which was assessed by specific resistance to filtration, supernatant filtration, capillary suction time and viscosity, decreased after sulfate addition. Organic and inorganic matters in the dynamic layer were characterized by SEM-EDS and FTIR analyses. © 2020 Elsevier B.V
Breast Cancer Related Lymphedema and Conservative Therapies
No full textWOS: 000269581400007Lymphedema is characterized by generalized or regional accumulation of protein-rich interstitial fluid that occurs as a consequence of congenital or acquired disruption of lymphatic circulation. Cancer-related lymphedema is the most common cause of secondary upper and lower extremity lymphedema. Secondary arm lymphedema is a chronic and disabling condition which affects a significant number of women who undergo breast cancer treatment. The incidence of breast cancer-related lymphedema was reported to be between 2.4 to 56%. Extensive surgical nodal clearing and irradiation are the most important risk factors for the development of lymphedema. Besides preventive approaches of treatment related complications and lymphedema, various therapeutic interventions have been proposed to treat this disabling condition. In the absence of well-designed randomized studies, consensus has not been attained concerning the appropriate treatment of lymphedema. Complex decongestive therapy, manual lymphatic drainage, self-adminitered lymphatic drainage, pneumatic pumps, laser therapy, oral pharmaceuticals, compression bandaging and garments, limb exercises and elevation are among the common conservative therapies used for managing lymphedema. This review overviews the risk factors, assessment methods, preventive approaches and treatment regimens that have been used for the management of lymphedema. Turk J Phys Med Rehab 2009;55:30-35
Intermittent Therapy with Terbinafine for Dermatophyte Toe-Onychomycosis: A New Approach
No full text- …
