Aksaray University Institutional Repository
Not a member yet
8503 research outputs found
Sort by
Coulomb, exchange, kinetic, nuclear attraction and ionization energies of two-electron quantum dot with finite confinement potential
No full textWe have calculated Coulomb, exchange and configuration-average ionization energies for the ground and excited configurations in helium atom confined by a spherical cavity of finite barrier height. In addition, we have carried out kinetic energies, nuclear attraction energies, confining potential energies and probabilities of finding the electrons that occupy different subshells. In the strong and intermediate confinement regions, the results show that the barrier height of potential well and dot size have a strong influence on the energies and probabilities. The kinetic energies of electrons in 1s and nl orbitals increase as the height of the potential barrier increases, but in nuclear attraction energies the opposite behavior occurs. It is found that Coulomb and exchange energies rapidly decrease after the critical confinement radii, in which the electron in nl orbital escapes out of the well. The configuration-ionization confinement radius depends strongly on the potential barrier height
Enhancing energy efficiency and cost-effectiveness while reducing CO2 emissions in a hospital building
No full textGlobal population growth drives fossil fuel usage, surpassing natural greenhouse gas emissions and causing climate change, higher temperatures, floods, and agricultural erosion. The study underscores the significance of appropriate material selection and meticulous building design to establish a healthy living environment and mitigate energy consumption. The research is dedicated to the reduction of CO2 emissions. Hospitals, due to their constant energy requirements, require optimal temperature and comfort management for patients, necessitating careful design to avoid disruptions and power outages. The principal objective of this research is to enhance energy efficiency in the design phase of hospital buildings in Turkey and to develop an energy-efficient hospital model. This objective is achieved by evaluating different insulation materials, building orientations, lighting efficiency, and window-to-wall ratios. The methodology involves creating a reference structure for energy load calculations using Revit software and utilizing the Green Building Studio (GBS) program to conduct energy analyses in 7 different cities across Turkey. The study found that the utilization of building parameters with renewable energy sources reduced energy consumption by 57.5%, total costs by 16.24%, and CO2 emissions by 26.3%. The fundamental contribution of this study is to demonstrate the feasibility of reducing energy consumption, costs, and CO2 emissions through design adjustments. The novelty of this research lies in its comprehensive approach to optimizing energy efficiency and CO2 emissions in hospital buildings in Turkey. These findings underline the significance of energy-efficient design, particularly considering the impact of increased energy usage and CO2 emissions during the COVID-19 pandemic
Effects of flour additives on gluten-free chicken croquettes
No full textWhen the gluten-free flours were used, hardness and chewiness significantly decreased (p < 0.01). The group of TC (chia flour) had the highest protein contents in croquette samples. The ash contents of the TC and TK (quinoa flour) samples were higher than that of the TB (wheat flour) and TM (corn flour) samples. The addition of corn flour increased the L* and b* parameters, while the a* parameter was increased when quinoa flour was used (p < 0.01). The highest WHC (water holding capacity) values were determined in chicken croquettes that included chia flour (p < 0.01). The group of TC had the lowest CL (cooking loss) in chicken croquettes. The highest Ca (calcium), Mg (magnesium), and P (phosphorus) contents were obtained in samples including chia flour (p < 0.01). The croquette samples treated with quinoa flour had the highest K (potassium) content (2421 mg/kg) and also the croquette samples treated with chia flour had a higher K content value (2080 mg/kg) than the control and corn flour treated samples (1696 and 1768 mg/kg, respectively). Chia, quinoa, and corn flour-added chicken croquettes (TC, TK, TM) had lower hardness, springiness, gumminess, and chewiness parameters than the control group. When all groups were evaluated, it was observed that the hardness values of TC were lower compared to TB, TK and TM croquettes. Microstructure analysis (SEM) results supported the changes in texture profile analysis (TPA) results. Croquettes containing chia, quinoa, and corn flour had higher texture and tenderness scores than the control group. As a result, chia, quinoa, and corn flour can be used as replacers for wheat flour in chicken croquette formulations
Design and walking analysis of proposed four-legged glass cleaning robot
Get PDFIn this study, a legged and wheeled robot model was proposed for cleaning the glass of greenhouses. The robot has four wheels and four legs, each with three degrees of freedom (DOF). The design, kinematic analysis and simulation of the robot was carried out. Glass greenhouses are created by placing glass sheets on T-shaped iron bars arranged in parallel at certain intervals. The robot performs the glass cleaning task by performing two different movements on greenhouse roof. As a first movement, the robot moves like a train moving on the rail on iron bars with wheels, cleaning the glass as it travels. After cleaning the glasses placed between two iron bars along a column, as second movement, the robot passes the next column using legs. These two movements continue until the entire roof of the greenhouse is cleaned. Kinematic analysis of this robot, which is designed with mechanical properties that can make these movements, has been made. Walking simulation of the robot was carried out according to the kinematic analysis. The simulation results showed that this proposed robot can be used to clean glass on the greenhouse roof
Stability Analysis Using Fractional-Order PI Controller in a Time-Delayed Single-Area Load Frequency Control System with Demand Response
Get PDFThe current study investigates the stability analysis based on gain and phase margin (GPM) using fractional-order proportional-integral (FOPI) controller in a time-delayed single-area load frequency control (LFC) system with demand response (DR). The DR control loop is introduced into the classical LFC system to improve the frequency deviation. Although the DR enhances the system’s reliability, the excessive use of open communication networks in the control of the LFC results in time delays that make the system unstable. A frequency-domain approach is proposed to compute the time delay that destabilizes the system using GPM values and different parameter values of the FOPI controller. This method converts the equation into an ordinary polynomial with no exponential terms by eliminating the exponential terms from the system’s characteristic equation. The maximum timedelay values at which the system is marginally stable are calculated analytically using the new polynomial. Finally, the verification of the time delays calculated is demonstrated by simulation studies in the Matlab/Simulink environment and the root finder (quasi-polynomial mapping-based root finder, QPmR) algorithm to define the roots of polynomials with exponential terms providing information about their locations
Ecotopia as an ecological sustainable city model, and current urban practices
Get PDFBu çalışmanın amacı, sürdürülebilir kalkınmanın eleştirisini yaparak, ekolojik sürdürülebilirliğin (eko-sürdürülebilirlik) önemini vurgulamak; eko-sürdürülebilirliğin bir kent ütopyası ile modelini çizmek, modeli ekokentler ve diğer kent pratikleriyle kıyaslamaktır. Kapsam, sürdürülebilirlik, eko-sürdürülebilirlik, eko-kentlerle ilgili literatür taraması; Ekotopya kitabının incelenmesi ve eko-sürdürülebilir kent girişimlerinin araştırmasıdır. Çevre sorunlarında sürdürülebilirlik tartışmalarını ekolojik açıdan yorumlayarak ekolojik sürdürülebilirliğin pratik olarak nasıl mümkün olacağını anlamak bakımından önemlidir. Çalışmada literatür taraması, kitap incelemesi ve web kaynaklarından araştırma ile literatür- pratik kıyaslaması yapılarak, karşılaştırmalı yöntem kullanılmıştır. Sürdürülebilirliğin, iddia edildiği gibi çevresel ve kentsel sorunlara çözüm olabilmesinin; yerel yönetimler, yenilenebilir enerji kaynakları, yerel üretim gibi minimal girişimlerle mümkün olacağı tartışılmaktadır. Bunlar, kent içi ulaşım, enerji ve geri dönüşüm konularında yoğunlaşmaktadır. Ekosürdürülebilirliği başarıyla uygulayan, güncel kent girişimlerini anlatması bakımından literatüre katkı yapacaktır. Eko-sürdürülebilir kent girişimleri araştırılırken diğer kentlere örnek olacak en başarılı kent örnekleri seçilmiştir.The aim of this study is to emphasize the importance of ecological sustainability (ecosustainability) by criticizing sustainable development; To draw a model of ecosustainability with an urban utopia, to compare the model eco-cities and other urban practices. Review on scope, sustainability, ecosustainability, ecocities. Also the review of the Ecotopia book and the research of ecosustainable city initiatives. It is important in terms of understanding how ecological sustainability can be practically possible by interpreting the sustainability discussions in environmental problems from an ecological perspective. A comparative method was used by making literature-practice comparison with literature review, book review and research from web resources. Sustainability can be a solution to environmental and urban problems as claimed; It is discussed that it will be possible with minimal initiatives such as local governments, renewable energy sources, local production. These concentrate on urban transport, energy and recycling. It will contribute to the literature in terms of describing current urban initiatives that successfully implement eco-sustainability. While researching ecosustainable city initiatives, the most successful city examples that will set an example for other cities have been selected
Experimental intervertebral disc degeneration models
Get PDFIntervertebral disc degeneration is a major health problem of close concern to both young and old. The problem is also growing as the global population ages. Intervertebral disc degeneration is defined as progressive changes affecting the spine as a component of natural aging under the effect of multiple factors (such as smoking, obesity, and incorrect exercise). For a solution to be found, experimental disc degeneration must first be induced, the causes of the disease must be identified, and early diagnostic and therapeutic methods must then be developed. Methods of inducing intervertebral disc degeneration with high applicability in rats were identified from the previous literature. This review discusses four methods of disc degeneration induction. It also discusses how to detect degeneration formation and development times. As a result of the literature review, information about four different and reliable intervertebral disc degeneration methods is presented
Relationship Between Heart Rate Recovery and Mean Platelet Volume in Healthy Individuals
Get PDFHeart rate recovery index (HRRI) and mean platelet volume (MPV) are two cardiovascular prognostic markers. Low HRRI and high MPV values have been observed in several diseases and conditions. However, the relationship between these two markers is unclear. In this study, the relationship between HRRI and MPV in healthy individuals is examined. Materials and Methods: The exercise tests performed between January and December 2020 were evaluated, and 120 individuals who met the study criteria were included in the present study. An abnormal HRRI was defined as a decrease in heart rate of 12 beats or more until one minute after the peak of exercise. Those with abnormal HRRI were defined as the study group (n=60), and those with normal HRRI as the control group (n=60). Results: A total of 120 healthy individuals were included in the study (54% female; mean age 40.14±7.90 years). High- er MPV values were detected in the study group when compared to the control group (10.27±0.10 fl vs. 9.44±0.12 fl; p<0.001). This significance continued in the logistic regression analysis (odds ratio=3.78, p<0.001). In addition, a moderate negative correlation was found between HRRI and MPV (r=-0.404, p<0.001). The MPV value of 10.25 fl was identified as an effective cutoff point for the prediction of abnormal HRRI (area under the curve [AUC]: 0.758; 95% confidence interval [CI]: 0.674–0.843). Conclusion: Healthy individuals with abnormal HRRI have elevated MPV levels. Additionally, a negative correlation be- tween MPV and HRRI in healthy subjects indicates a causal relation between MPV and autonomic dysfunction
Evaluation of relationship between SOD1 50-bp deletion gene polymorphism, Cu, Zn Level, and viscosity in postmenopausal osteoporosis patients with vertebral fractures
No full textOxidative stress plays a role in the pathogenesis of bone loss, causing low bone mineral density (BMD) and associated osteoporotic fractures. In our study, we aimed to investigate the relationship of SOD1 50-bp insertion( Ins)/deletion( Del) polymorphism that is involved in oxidative stress metabolism, Cu and Zn element concentrations, and plasma viscosity level, with postmenopausal osteoporosis and related vertebral fractures. The study included 167 voluntary individuals. The 50- bp Ins/Del polymorphism of SOD1 was determined by allele-specific PCR. Plasma Cu and Zn levels were measured by atomic absorption spectrophotometry (AAS). The plasma viscosity was determined using the Harkness Capillary Viscometer device. In our study, the distribution of SOD1 promoter 50-bp Ins/Del polymorphism did not indicate a significant difference between the groups and in postmenopausal osteoporosis patients with and without fractures (p > 0.05). The Ins/Ins genotype was found to be common in individuals in both groups. The Cu and Zn levels of the study group were found to be between the normal reference values (p > 0.05). It was determined that plasma viscosity increased significantly in the group of osteoporotic patients and in patients with postmenopausal osteoporosis with fractures (p < 0.01). In addition, plasma viscosity was found to significantly increase in patients with Ins/Ins genotype and fractures (p < 0.01). Postmenopausal osteoporosis and associated vertebral fracture were found not to be directly related to SOD1 50-bp polymorphism and Cu and Zn element levels. Plasma viscosity levels were found to increase due to the increase in oxidative stress products. Further studies are needed to clarify the roles and relationships of SOD genes and trace elements in the development of postmenopausal osteoporosis and vertebral fracture
Detection of face mask with convolutional neural network models to reduce COVID19 spread
No full textSon yıllarda hayatımızın gerçeği olan ve tüm dünya için pandemi haline gelen Covid-19'un gerekli tedbirlere sıkı şekilde uyulmadığı takdirde bulaşma oranı artmakta hatta varyantları bile ortaya çıkmaya başlamaktadır. Dünya Sağlık Örgütü tarafından yayınlanan ve alınması gerekli olan tedbirler alındıkça hastalıkla mücadele daha kolay hale gelebilmektedir. Tedbirlere uymanın zorluğu olsa da uymaya özen gösterildiği taktirde, hastalık ya daha hafif atlatılmakta ya da hastalığa kolayca yakalanılmamaktadır. Bu tedbirlerin en önemlilerinden birisi de kalabalık alanlarda maske kullanımına özen gösterilmesidir. Maske kullanımının önemi araştırmalarla desteklenmesinden sonra, bazı alışveriş merkezi, sağlık kuruluşları, okullar gibi kalabalık mekanlarda maske kullanımına yönelik denetimler başlamıştır. Ancak bu denetimleri bir insanın gerçekleştirmesi zor olduğundan günümüzde sıklıkla kullanılan derin öğrenme yöntemleriyle maske tespiti çalışmaları yapılmaya başlanmıştır. Bu tez çalışmasında, transfer öğrenme tabanlı modeller kullanılarak maske tespiti gerçekleştirilmesi amaçlanmaktadır. Kaggle web sitesinde bulunan veri seti üzerinde toplamda 906 görüntü ile DenseNet121, EfficientNetV2M, NasNetMobile, InceptionV3 ve VGG19 derin öğrenme modelleri kullanılmıştır. Deneysel değerlendirmeler sonucunda, en iyi başarı oranı olarak NasNetMobile modeliyle, %99.35 doğruluk, %99 kesinlik, %99 geri çağırma ve %99 f1 skorları elde edildiği görülmüştür.In recent years, Covid-19, which has become a reality of our lives and has become a pandemic for the whole world, increases the rate of infection and even variants of it begin to appear if the necessary precautions are not strictly followed. As the measures published by WHO and necessary to be taken are taken, the fight against the disease may become easier. Although it is difficult to comply with the measures, if care is taken to comply, the disease is either milder or the disease is not easily caught. One of the most important of these measures is to pay attention to the use of masks in crowded areas. After the importance of mask use was supported by research, inspections for the use of masks in crowded places such as some shopping malls, health institutions and schools began. However, since it is difficult for a human to perform these inspections, mask detection studies have begun to be carried out with deep learning methods, which are frequently used today. In this thesis, it is aimed to perform mask detection using transfer learning based models. DenseNet121, EfficientNetV2M, NasNetMobile, InceptionV3 and VGG19 deep learning models were used with a total of 906 images with the data set available on the Kaggle website. As a result of the experimental evaluations, it was seen that the best success rate was obtained with the NasNetMobile model, with 99.35% accuracy, 99% precision, 99% recall and 99% f1 scores