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Experimental Investigation of the Boundary Effects for Flexible Piping Systems from Small to Large Scales
No full textReal field conditions must be realistically reflected in the laboratory to ensure practical design, safety, and long service life. To eliminate conflicts between reality and modeling, boundary limits need to be considered. In this study, the effects of boundary conditions on the deformation of the embedded material and the stresses in the boundary section were investigated in large-scale and small-scale rigid test boxes. This study aims to show the effects of the boundary conditions selected in laboratory experiments on the deformations of the buried material at different relative density levels, which are determined as loose, mid-dense, and dense conditions. In addition, under the effect of the vertical load applied to the soil surface, the regions where the boundaries of the study area are subject to stress were determined according to the degree of compactness. Buried pipes were used as a measuring assembly to detect deformations in all experiments carried out at both scales on sandy soils representing different relative density conditions. In large-scale tests, deformation on the test box walls was not observed in the experiments where the infinite site conditions were reflected realistically. In experiments where boundary conditions were not considered, stress magnitudes affecting the behavior were observed in small-scale box walls. When the stress distributions were examined in experiments conducted under different relative density conditions, the greatest interaction with the box wall was observed with the loosest soil. For the case where the limits were inadequate, stresses between 56 and 100% reached the wall surface of the small-scale test box, showing higher variable displacements between 1.6 and 2.1 times in the pipe sections compared to the large-scale box. As a result, the study reveals the degree to which the design limits affect the deformation values according to the compactness in full-scale laboratory experiments
Does Economic Policy Uncertainty Cause Environmental Pollution? Fresh Evidence From Developed Countries
No full textThe industrial revolution has dramatically altered the environment and ecosystem. So many scholars have empirically attempted to reveal the most influential anthropogenic factors on environmental degradation. For this purpose, this study examines the leading determinants of CO2 emissions in the context of economic policy uncertainty (EPU) for 14 developed countries within the framework of the extended stochastic impacts by regression on population, affluence and technology (STIRPAT) environmental model from 1997–2018. For empirical modeling, CO2 emission is treated as the dependent variable, which is a strong proxy for environmental degradation. In addition to the GDP per capita, population density, and energy intensity (a proxy for technology), the basic model is extended to include variables such as EPU, renewable energy, trade openness, globalization, and information and communications technology (ICT) index. While the estimation results by the dynamic conditional correlation (DCC) estimator, which are also supported by robustness analysis, suggest that GDP per capita and energy intensity are the main contributors to emission levels, population density has no significant impact on CO2. Furthermore, while renewable energy (in model 2), trade openness (in model 4), and globalization (in model 6) have negative impacts on CO2 emission, technology (in models 5 and 6) and EPU (in model 6) make marginal contributions to CO2
Zaman gecikmesi içeren üçüncü derece sistemler için kesir dereceli PD denetleyici tasarımı
Full text linkDue to the lack of integral operator, proportional derivative controllers have difficulties in providing stability and robustness. This difficulty is especially felt in higher order systems. In this publication, analytical design method of fractional proportional derivative controllers is presented to ensure the stability of third order systems with time delay. In this method, it is aimed to achieve the frequency characteristics of a standard control system to ensure stability. It is aimed to provide the desired gain crossover frequency, phase crossover frequency and phase margin properties of the system. In this way, the stability and robustness of the system can be obtained by choosing the appropriate values. The reason for choosing a fractional order controller is that the controller parameters to provide these features can be tuned more accurately. In order for the obtained stability to be robust to unexpected external effects, it is aimed to flatten the system phase. In the literature, phase flattening is performed by setting the phase derivative to zero at a specified frequency value. This can lead to mathematical complexity. In this publication, the phase flattening process is provided graphically by correctly selecting the frequency characteristics given above. Thus, an accurate and reliable controller design method is presented, avoiding mathematical complexity. The effectiveness of the proposed method has been demonstrated on three different models selected from the literature. The positive contribution of the method to the system robustness has been proven by changing the system gain at certain rates.İntegral operatörünün eksikliğinden dolayı, oransal türev denetleyiciler kararlılık ve dayanıklılığı sağlama konularında zorlanabilmektedir. Bu zorluk, özellikle yüksek dereceli sistemlerde kendini daha çok hissettirmektedir. Bu yayında, zaman gecikmesi içeren üçüncü derece sistemlerin kararlılığının sağlanması için kesir dereceli oransal türev denetleyicilerin analitik tasarım yöntemi sunulmuştur. Bu yöntemde kararlılığın sağlanması için standart bir kontrol sisteminin sahip olduğu frekans özelliklerine ulaşılması hedeflenmiştir. Sistemin istenen kazanç kesim frekansı, faz kesim frekansı ve faz payı özelliklerini sağlaması hedeflenmiştir. Bu şekilde uygun değerler seçilerek sistemin kararlılığı ve dayanıklılığı elde edilebilecektir. Kesir dereceli bir denetleyicinin seçilme sebebi de bu özelikleri sağlayacak denetleyici parametrelerinin daha doğru şekilde ayarlanabilmesidir. Elde edilen kararlılığın beklenmeyen dış etkilere karşı dayanıklı olması için de sistem fazının düzleştirilmesi hedeflenmiştir. Literatürde faz düzleştirme işlemi, faz türevinin belirlenen bir frekans değerinde sıfırlanması ile gerçekleştirilmektedir. Bu da matematiksel karmaşıklığa yol açabilmektedir. Bu yayında ise faz düzleştirme işlemi yukarıda verilen frekans özelliklerinin doğru şekilde seçilmesi ile grafiksel olarak sağlanmaktadır. Böylece matematiksel karmaşıklıktan kaçınılarak, doğru ve güvenilir bir denetleyici tasarım yöntemi sunulmuştur. Önerilen yöntemin etkinliği literatürden seçilmiş üç farklı model üzerinde gösterilmiştir. Yöntemin sistem dayanıklılığına pozitif katkısı ise sisteme kazancının belli oranlarda değiştirilmesi ile ispatlanmıştır
An inclusive physico-chemical perspective on food waste: Textural and morphological structure
No full textIn recent years, thanks to their advantages such as low cost, easy availability, reusability as adsorbent materials, and high metal ion removal capacities in aqueous solutions, food waste attract the attention of researchers. In this study, almond shell (AS), peanut shell (PS), walnut shell (WS), and pumpkin seed hull (PSH) were characterized using analytical methods such as Fourier Transform Infrared (FTIR) Spectroscopy, Scanning Electron Microscope (SEM)/Energy dispersed X-ray (EDX), and Brunauer–Emmett–Teller (BET). The surface morphologies, functional groups, surface area, and pore size of AS, PS, WS, and PSH were evaluated together, and their specific properties were revealed. According to EDX analysis, %C and %O content is high for all biosorbents. Using FTIR analysis, carboxylic (–COOH), amines (N–H) and hydroxyl groups (–OH) in the structure of AS, WS, PS, and PSH were determined. Pore morphologies were determined as mesopore (250 nm) for AS, PS, WS, and PSH. Surface areas for AS, PS, WS and PSH were determined as 6.20, 4.12, 3.98 and 2.74 m2/g, respectively. In addition, using the Principal Component Analysis (PCA) model, the effect levels of AS, PS, WS, and PSH on the adsorption process were determined by FTIR and EDX data sets. With the increasing interest in environmental preservation, it is anticipated that low-cost food waste-based biosorbents will be utilized in various applications in the future
Quṭb al-Dīn al-Shīrāzī’s Criticism of Rational Philosophy and Peripatetic Definition Theory: : An Analy-sis within the Con-text of Şarh Ḥikmat al-Ishrāq
Full text linkBu çalışmanın amacı, Kutbuddin eş-Şirâzî’nin akılcı felsefeye ve Meşşâî tanım teorisine yönelik eleştirileri incelemektir. İşrâk felsefesi söz konusu olduğunda akla gelen ilk isimlerden biri Kutbuddin eş-Şirâzî’dir. Bu bağlamda 14. yüzyılda yaşamış olan Şirâzî, hem Sühreverdî’nin eserine şerh yazarak hem de müstakil eserler kaleme alarak İşrâkî tavrıyla dikkat çekmektedir. Bu anlamda İşrâkî tavırla ilgili en açık ifadeleri Hikmetü’l-işrâk’a yazdığı şerhte rastlamak mümkündür. Şirâzî, İbn Sînâ’nın tarif teorisine eleştiriler yönelterek tanımın; ortak kurucu unsurlardan yani cins ve ayırt edici kurucu unsurların toplamından meydana gelmesinin zor olduğunu belirtir. Biz bu çalışmada öncelikle Şirâzî’nin Hikmetü’l-işrâk’a yazdığı şerhinin “mukaddimesinde” yer alan İbn Sînâ’ya yönelik eleştirilerini, bahsî hikmete zarar verdikleri görüşünü ve İşrâk felsefesinin kaynaklarını ele almaya çalışacağız. Daha sonra Şirâzî’nin tarif konusunda İbn Sînâcı tarif teorisine yönelik eleştirilerin inceleyeceğiz. Elde ettiğimiz bilgilerden hareketle de, Şirâzî’nin İşrâkîlik tasavvurunu ortaya koymaya, eleştirilerinin kaynağını ve getirdiği çözüm önerileri ele alınacaktır.The aim of this study is to examine the criticisms of rational philosophy and Peripatetic definition theory. al-Shīrāzī who lived during the 14th century attracts attention with his illuminative attitude by both writing an annotation to Suhrawardī’s work and writing independent Works. al-Shīrāzī criticizes Ibn Sīnā’s theory of description and stresses that it is hard for description to comprise of common constituent elements, namely the sum of types and distinctive constituent elements. The present study will primarily try to discuss al-Shīrāzī’s criticism of Ibn Sīnā in the “preface” of his annotation to Ḥikmat al-Ishrāq, as well as damages to the aforementioned philosophy and resources of illuminative philosophy Then examine the criticism toward Ibn Sīnā’s theory of description regarding al-Shīrāzī’s description. Considering the data acquired, the study aims to reveal al-Shīrāzī’s illuminative perception and examine the resources of criticism and solution offers generated
Evaluation of HLA-B51 frequency and its relationship with clinical findings in patients with Behcet's disease: 4-year analysis in a single center
Full text linkThe clinical findings of Behcet's disease (BD) differ according to the country and race investigated. The most important genetic factor known in the pathogenesis of BD is HLA-B51, and this positivity is high in countries on the "Silk Road" where BD is as frequent as it is in Turkey. Although the positivity of HLA B51 is proven to be high in Turkey, there are no studies in the area of the western Black sea demonstrating its relation to the demographic. We aimed to investigate the association of HLA-B51 positivity in Turkish patients diagnosed as having BD and the relationship between the demographic and clinical findings of the patients.ResultsIn this descriptive, cross-sectional study, a convenience sample of adults with BD was obtained from an outpatient clinic of a university hospital in Turkey between January 2018 and January 2022. Patients were diagnosed as having BD according to the criteria of the International BD Study Group, and the patients' sociodemographic and clinical characteristics were recorded retrospectively. Demographic data and the frequency of clinical findings were compared between patients who were HLA-B51-positive and HLA-B51-negative. Sixty patients (55.6%) were HLA-B51-positive. Oral ulceration, genital ulceration, thrombophlebitis, and family history of BD were found to be higher in patients who were HLA-B51-positive. Erythema nodosum, papulopustular eruption, pathergy positivity, arthritis, and ocular involvement were less frequent in patients with HLA-B51 positivity. However, there were no statistically significant differences according to the frequency of clinical findings between the HLA-B51-positive and HLA-B51-negative groups.ConclusionsHLA B51 positivity is not diagnostic of BD; however, it may affect clinical phenotypes. Although oral and genital ulcerations, thrombophlebitis, and positive family history of BD were found to be common in patients with HLA-B51 positivity, this relationship could not reach statistical significance
Ultrasonic-assisted photocatalytic degradation of various organic contaminants using ZnO supported on a natural polymer of sporopollenin
Full text linkWater resource pollution by organic contaminants is an environmental issue of increasing concern. Here, sporopollenin/zinc oxide (SP/ZnO) was used as an environmentally friendly and durable catalyst for sonophotocatalytic treatment of three organic compounds: direct blue 25 (DB 25), levofloxacin (LEV), and dimethylphtalate (DMPh). The resulting catalyst had a 2.65 eV bandgap value and 9.81 m2/g surface area. The crystalline structure and functional groups of SP/ZnO were confirmed by X-ray diffraction (XRD) and Fourier transforms infrared spectroscopy (FTIR) analyses. After 120 min of the sonophotocatalysis, the degradation efficiencies of DB 25, LEV, and DMPh by SP/ZnO were 86.41, 75.88, and 62.54%, respectively, which were higher than that of the other investigated processes. The role of reactive oxygen species were investigated using various scavengers, enhancers, photoluminescence, and o-phenylenediamine. Owing to its stability, the catalyst exhibited good reusability after four consecutive cycles. In addition, the high integrity of the catalyst was confirmed by scanning electron microscopy (SEM), XRD, and FTIR analyses. After four consecutive examinations, the leaching of zinc in the aqueous phase was < 3 mg/L. Moreover, gas chromatography-mass spectrometry (GC–MS) analyses indicated that the contaminants were initially converted into cyclic compounds and then into aliphatic compounds, including carboxylic acids and animated products. Thus, this study synthesized an environmentally friendly and reusable SP/ZnO composite for the degradation of various organic pollutants using a sonophotocatalytic process
Evaluation of the Effect of Class Level and Gender Variable on Intelligibility in Written Texts
Full text linkMetin yazabilmek ve yazılı metinleri anlayabilmek çok boyutlu bir yapıya sahiptir. Bu nedenle metnin niteliği aynı zamanda metnin anlaşılmasında da etkilidir. Bu araştırmada iletişimsel, estetik ve akademik amaçlarla yazılan metinlerin anlaşılırlığının belirlenmesi amaçlanmaktadır. Bu bağlamda sınıf düzeyi ve cinsiyet değişkenlerinin metinlerin anlaşılırlık durumuna etkisi gözlemlenmeye çalışılmıştır. Araştırmada karma yöntem kullanılmıştır. Nicel yöntemlerden tarama modeli ve nitel yöntemlerden ise durum çalışması kullanılmıştır. Araştırmanın çalışma grubunu eğitim fakültesi öğrencileri oluşturmaktadır. Elde edilen veriler çeşitli istatistiksel yöntemler ve içerik analizi ile yorumlanmıştır. Araştırma sonuçlarına göre hem cinsiyet hem de sınıf düzeyi değişkenlerinin akademik metinlerin anlaşılırlığını etkilediği belirlenmiştir. Eğitim fakültesi öğrencilerinin yazdıkları metinlerin genel olarak anlaşılır olduğu görülmüştür. Araştırmaya katılan kız öğrencilerin yazdığı akademik metinlerin, erkek öğrencilerin yazdığı akademik metinlere göre daha anlaşılır olduğu tespit edilmiştir. Ayrıca araştırmaya katılan dördüncü sınıf öğrencilerinin yazdığı akademik metinlerin, birinci sınıf öğrencilerinin yazdığı akademik metinlere göre daha anlaşılır olduğu sonucuna ulaşılmıştır.Writing a text and understanding it have a multidimensional structure. Therefore, the quality of the text has a direct effect on its comprehension. This study aims to determine the intelligibility of the texts written for communicative, aesthetic, and academic purposes. In addition, the effect of class level and gender variables on the intelligibility was tried to be observed. Quantitative and qualitative methods were used in this study. The study group of the research consisted of students in a faculty of education. The obtained data were interpreted with various statistical methods and content analysis. According to the results of the research, it has been determined that both gender and class level variables affect the intelligibility of academic texts. The texts written by the students of the faculty of education were found to be generally intelligible. It has been found out that the academic texts written by the female students who participated in the research are more intelligible than those written by the male students. It has been determined that the academic texts written by the fourth-year students participating in the research are more intelligible than those written by the first-year students
Türkçe eğitiminde millî egemenlik ve demokrasi kavramlarının kullanımı
Full text linkMillî eğitimin, özellikle millî konuların öğretilmesinde ve bir ülkenin geçmişine, bugününe ve geleceğine dair önemli kararların alınmasında katkısı oldukça büyüktür. Hayatın en önemli duraklarından biri olan millî eğitimin insan üzerindeki rolü tartışılmaz bir gerçektir. Millî konuların öğretiminde Türkçe eğitimi ayrı bir öneme sahiptir. Bu sebeple Türkçe eğitiminin öğretim programından ders kitaplarına kadar titizlikle planlanması gerekir. Ortaokul çağı somut işlemlerden soyut işlemlere geçiş dönemi olduğu için bu dönemde millî egemenlik ve demokrasi konularında verilecek nitelikli bir eğitim oldukça önemlidir. Bu çalışmanın amacı, millî egemenlik ve demokrasi kavramlarına Türkçe Eğitimi'nde ne kadar yer verildiğini tespit etmektir. Bu amaç doğrultusunda 2019 Türkçe Dersi Öğretim Programı ve 2019-2020 eğitim-öğretim yılında okutulan 5, 6, 7 ve 8. sınıf Türkçe ders kitaplarındaki millî egemenlik ve demokrasi kavramlarıyla ilişkili hedefler, kazanımlar, temalar ve metinler tespit edilmeye çalışılmıştır. Çalışmada nitel araştırma desenlerinden temel nitel araştırma deseni kullanılmış, veriler doküman incelemesi yoluyla elde edilmiştir. Araştırma sonucunda elde edilen veriler içerik analizi yoluyla kategorilere ayrılmış ve ulaşılan bu bulgular betimsel analizle yorumlanmıştır. Çalışmada ilk olarak güncel Türkçe Dersi Öğretim Programı’ndaki genel ve özel amaçlara bakılmıştır. Genel amaçlarda 2 amacın, özel amaçlardan da 1 amacın millî egemenlik ve demokrasi kavramıyla ilişkili olduğu belirlenmiştir. Türkçe Dersi Öğretim Programında incelenen bir diğer bölüm, temalar bölümüdür. Programda yer verilen 16 temadan 5’inde millî egemenlik ve demokrasi kavramlarıyla doğrudan ilişkili konulara yer verildiği tespit edilmiştir. Bu tespit yapılırken temaların altında yer verilen konular önemli bir gösterge olmuştur. Millî egemenlik ve demokrasi kavramlarının temaların içindeki oranına bakıldığında, gayet iyi bir orana sahip olduğu söylenebilir. Neredeyse temaların üçte biri millî egemenlik ve demokrasi kavramlarıyla ilişkilidir. Türkçe Dersi Öğretim Programında son olarak incelenen kısım kazanımlar kısmıdır. Programda yer alan 5, 6, 7 ve 8. sınıf dinleme/izleme, okuma, konuşma ve yazma kazanımlarının hiçbirinde millî egemenlik ve demokrasi kavramlarıyla doğrudan ilişki tespit edilememiştir. Bu durum oldukça dikkat çekicidir çünkü özellikle ders kitaplarının içindeki etkinlikler, ders içi aktiviteler, sınav soruları vb. hazırlanırken kazanımlar dikkate alınmaktadır. Dolayısıyla öğrencinin en çok dikkat ettiği ve aktif olduğu bu alanlarda millî egemenlik ve demokrasi kavramlarıyla karşılaşma olasılığı düşmektedir. Bu durum programdaki bir eksiklik olarak görülebilir. Hazırlanacak olan programlarda kazanımlar içerisinde de genel ve özel amaçlara, temalara uygun olarak millî egemenlik ve demokrasi kavramlarına yer verilmesi, bu kavramların öğrenciler tarafından daha iyi özümsenmesini sağlayacaktır. Ayrıca bu kavramların öğretilmesinde, sarmal bir öğretimin planlanması, bu konuda istenilen hedeflere ulaşılmasını kolaylaştıracaktır.National education, especially in the teaching of national issues and in making important decisions about the past, present and future of a country, is quite great. The role of national education, which is one of the most important stops of life, on human beings is an indisputable fact. Turkish education has a special importance in the teaching of national subjects. For this reason, Turkish education should be planned meticulously from the curriculum to the textbooks. Since the secondary school age is the transition period from concrete transactions to abstract transactions, a qualified education to be given in the subjects of national sovereignty and democracy is very important in this period. The aim of this study is to determine how much space is given to the concepts of national sovereignty and democracy in Turkish Education. In line with this purpose, the objectives, achievements, themes and texts related to the concepts of national sovereignty and democracy in the 2019 Turkish Course Curriculum and the 5th, 6th, 7th and 8th grade Turkish textbooks taught in the 2019-2020 academic year were tried to be determined. In the study, basic qualitative research design was used from qualitative research designs and data were obtained through document review. The data obtained as a result of the research were divided into categories through content analysis and these findings were interpreted by descriptive analysis. In this study, first of all, the general and specific objectives of the current Turkish Course Curriculum were examined. It was determined that 2 objectives in general purposes and 1 purpose in special purposes were related to the concept of national sovereignty and democracy. Another section examined in the Turkish Course Curriculum is the themes section. It was determined that 5 of the 16 themes included in the program included issues directly related to the concepts of national sovereignty and democracy. While making this determination, the issues included under the themes have been an important indicator. When we look at the ratio of the concepts of national sovereignty and democracy in the themes, it can be said that it has a very good ratio. Almost a third of the themes are related to the concepts of national sovereignty and democracy. Finally, the achievements in the program were examined and none of the 5th, 6th, 7th and 8th grade listening/watching, reading, speaking and writing achievements could be directly related to the concepts of national sovereignty and democracy. This is quite remarkable because the achievements are taken into consideration especially when preparing the activities in the textbooks, in-class activities, exam questions, etc. This is a deficiency because the possibility of encountering the concepts of national sovereignty and democracy in the activities during the course process decreases. In the programs to be prepared, the inclusion of the concepts of national sovereignty and democracy in the achievements will enable students to better understand these concepts. In addition, in the teaching of these concepts, planning a spiral teaching will facilitate the achievement of the desired goals in this regard
Usefulness of the four-variable formula on serial electrocardiograms in detecting subtle anterior myocardial infarction
No full textTo perform serial electrocardiogram (ECG) analyses in patients with subtle ECG changes in the anterior leads and evaluate the performance of the four-variable formula in detecting left anterior descending (LAD) coronary artery occlusion. Methods: This prospective study included patients admitted to the emergency department with acute chest pain between April 2021 and January 2023, whose initial ECG was not diagnostic but indicated suspicion of myocardial infarction (MI) and who underwent percutaneous coronary intervention in their follow-up. The control group consisted of patients who were diagnosed with benign variant ST-segment elevation (BV-STE) due to ST-segment elevation (STE) of at least 1 mm in the anterior lead, who had normal cardiac troponin levels, and who presented with non-cardiac chest pain. Following admission, six ECGs were taken at 10-min intervals. The scores of all patients were calculated with the four-variable formula on serial ECGs and compared between the groups. Results: A total of 232 patients, including 116 with anterior MI and 116 with BV-STE, were included in the study. When the cut-off value for the four-variable formula was taken as ≥18.2, the sensitivity, specificity, and diagnostic accuracy of the first ECG were determined to be 82.7%, 85.3%, and 83.6%, respectively. We found that the four-variable formula had the highest sensitivity, specificity, and diagnostic accuracy in detecting LAD occlusion for the ECG taken at the 20th minute (83.6%, 89.6%, and 86.2%, respectively). Conclusion: The four-variable formula was found to be a valid method for the differentiation of STEMI and BV-STE in patients with subtle ECG changes. While managing this patient group, using serial ECGs rather than a single ECG to evaluate the clinical status of patients can help clinicians make more accurate decisions