518 research outputs found
Dynamic phase transitions on the kagome Ising ferromagnet
We perform extensive Monte Carlo simulations to investigate the dynamic phase
transition properties of the two-dimensional kinetic Ising model on the kagome
lattice in the presence of square-wave oscillating magnetic field. Through
detailed finite-size scaling analysis, we study universality aspects of the
non-equilibrium phase transition. Obtained critical exponents indicate that the
two-dimensional kagome-lattice kinetic Ising model belongs to the same
universality class with the corresponding Ising model in equilibrium. Moreover,
dynamic critical exponent of the local moves used in simulations is determined
with high precision. Our numerical results are compatible with the previous
ones on kinetic Ising models.Comment: 18 pages, 12 figures. Accepted for publication in Phys. Rev.
Bioactivity of a betabaculovirus, Hyphantria cunea granulovirus, in six lepidopteran insects as potential hosts
The aim of this study, conducted in 2018 and 2020, was to investigate the bioactivity of a local baculovirus isolate, Hyphantria cunea granulovirus (HycuGV), in seven lepidopteran pests. Based on data collected 10 days after exposure, HycuGV was found to infect Malacosoma neustria (L., 1758) (Lepidoptera: Lasiocampidae), Lymantria dispar (L., 1758) (Lepidoptera: Erebidae), Helicoverpa armigera (Hubner, 1805) (Lepidoptera: Noctuidae) and Spodoptera exigua (Hubner, 1808) (Lepidoptera: Noctuidae) larvae as well as its host Hyphantria cunea (Drury, 1773) (Lepidoptera: Erebidae). However, it did not infect Spodoptera littoralis (Boisduval, 1883) (Lepidoptera: Noctuidae) and Cydia pomonella (L., 1758) (Lepidoptera: Tortricidae). A HycuGV dose rate experiment indicated LC50 of 4.7x10(5) occlusion bodies (OBs)/ml in H. cunea, 5.6x10(6) OBs/ml in L. dispar, 7x10(7) OBs/ml in S. exigua, 1.5x10(9) OBs/ml in M. neustria and 7.7x10(9) OBs/ml in H. armigera. HycuGV was infectious to S. exigua and L. dispar, but only provided effective control in M. neustria and H. armigera at high dose rates. These findings demonstrate that HycuGV can be highly effective for control of S. exigua, L. dispar and H. cunea
Alüminyum boyasının parlaklık ve kaplama değerlerini yapay sinir ağları ve çoklu regresyon yöntemleri ile tahmini
06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Doğada pek çok şey bilinmeyen doğa kurallarına göre meydana gelmektedir. Ve insanoğlu bunu tahmin edemediği sürece bunların olumlu veya olumsuz sonuçlarına katlanmak durumunda kalmaktadır. Örneğin fiyat istikrarsızlıkları önemli sorunlara ve olağandan fazla maliyete yol açmaktadır. Enflasyondaki belirsizlik finansal kesimde ve reel kesimde ekonomik kararları etkilemektedir. Veya yağacak olan yağmur miktarını tahmin edememe tarımı buradan yapılacak hasadı doğrudan etkilemektedir. Bu gibi pek çok nedenle insanoğlu tahmin etmenin önemini kavramasıyla çeşitli tahmin yöntemleri geliştirilmiştir. Yeryüzünde oksijen ve silisyum'dan sonra en çok bulunan üçüncü elementtir. Yerkabuğunda oksijen ve silisyum'dan sonra en çok bulunan (ağ. %8,1) metal alüminyumdur. Bu nedenle diğer metallerden daha ucuz daha kolay işlenebilir ve daha hafif olması nedeniyle endüstriyel anlamdan yüzlerce farklı alanda kullanımı vardır. İnşaat sektörlerinde dış cephe olarak boyalı alüminyum levhalar kullanılmaktadır. Dış cephe levhalarında dikkat çekici farklılığa sahip iki faktör bulunmaktadır. Bunlar müşteri için oldukça kritikleşen Parlaklık değeri ve üretici verimliliğini artıran Kaplama Alanı değeridir. Bu çalışmada ise bunlar arasında oldukça yaygın olarak kullanılan yapay sinir ağları ve çoklu regresyon yöntemleri ele alınarak boya Kaplama Alanı ve Parlaklığı konusunda bir çalışması ve tahminlemesi gerçekleştirilmiştir.In nature, many things occur according to unknown nature rules. And so long as human beings cannot predict it, they have to bear the consequences. For example, price instabilities lead to significant problems and many costs. The uncertainty in inflation affects the decisions of economic units in financial sector and real sector. Or the inability to predict the amount of rain to be rained directly affects its cultivation and harvest. Various estimation methods have been developed by understanding the importance of human estimation for many reasons. In this study, artificial neural networks and multiple regression methods which are widely used among them are described. Then, a study and estimation of the paint coating area and brightness were carried out. It is the third most common element in the world after oxygen and silicon. In the earth's crust, after oxygen and silicon, the most common metal (8,1%) is aluminum. Therefore, cheaper than other metals can be processed more easily and lighter because of the industrial meaning has hundreds of different uses. Painted aluminum sheets are used as exterior facades in construction sectors. There are two factors with remarkable differences in the exterior panels. These are highly critical luster values for the customer and the coating area value that increases the productivity of the manufacturer. In this study, artificial neural networks and multiple regression methods, which are widely used among them, were studied, and a study and estimation of the paint coverage area and brightness were performed
A study to access the Impact of Magnesium Deficiency in the Obese Individuals
Background: Obesity is an important health problem among developed and developing countries. Magnesium (Mg) deficiency is seen in obese individuals. Aim: To investigate the effect of Mg deficiency on insulin resistance in obese subjects. Methods: In this retrospective study, patients admitted to our hospital between 1 January 2016 and 31 December 2016 were included and data were retrieved from their medical records. We collected values of HbA1c, Mg, Glucose and Homa-IR and other biochemical tests. According to Body Mass Index (BMI), patients were divided into 3 groups. The relationship between Mg level and BMI was analyzed. Meanwhile, we also observed the relation between insulin resistance and BMI and relation between Hba1c and BMI. Results: A total of 134 patients, 21 male and 113 female, were included in the study. There was no statistical significance in serum Mg levels between the groups and there was a weak negative correlation between BMI and serum Mg levels. The correlation between BMI and insulin resistance was found to be moderately positive. On comparing, BMI and HbA1c between groups; it was statistically significant the groups consisting of BMIs below 25 and between 25-35, and the groups consisting of BMIs below 25 and >35. There was moderate positive correlation between BMIs and HbA1c levels. A negligible positive correlation between Mg levels and insulin resistance was observed. A weak negative correlation was found between Mg and HBA1C levels. Conclusion: Serum MG deficiency can be seen in obese individuals. Low serum Mg levels may accelerate the development of diabetes in obese individuals
Macro explanatory factors of Turkish tourism companies’ stock returns
This study examines whether the stock prices of Turkish tourism companies respond to growth in eight macro-economic variables namely, consumer price index, imports, exchange rate, consumer confidence index, oil price, money supply, foreign tourist arrivals, and monthly stock market return. By applying the Granger causality procedure, we find that growth in the consumer confidence index and imports could Granger cause tourism companies’ stock returns among eight macro factors in Turkey during the 2005 to 2013 period. After considering the structural break that occurred in 2007, the pre-break results indicate that the consumer confidence index, exchange rate, and foreign tourist arrivals could Granger cause tourism stock returns. However, the results in the post-structural break period reveal that only growths in oil prices and imports are significant
Öğrencilerin Matematik Hakkındaki İnançları: Betimsel Bir Çalışma
This study was designed to investigate primary school students’ beliefs about mathematics. A sample of 563 students from two primary schols were administered the “Beliefs about Mathematics Survey (BMS)’’. The survey, which was developed by the researchers, included 20 items in three subscales: beliefs about the nature of mathematics, beliefs about the process of learning mathematics, and beliefs about the use of mathematics. The results indicated that there were significant differences between students’ beliefs with respect to grade level and mathematics achievement. However, no significant differences were observed on the three subscales of BMS with respect to sex.Bu çalışma ilköğretim okulu öğrencilerinin matematik hakkındaki inançlarını belirlemek amacıyla yapılmıştır. Çalışmada iki ilköğretim okulundan katılan 563 Öğrenciye Matematik Hakkındaki İnançlar Anketi (MİA)” uygulanmıştır. Araştırmacılar tarafından geliştirilmiş olan anket, matematik hakkındaki inançlar, matematik öğrenme süreci hakkındaki inançlar ve matematiğin kullanımı hakkındaki inançlar boyutları altında 20 maddeden oluşmaktadır. Bulgular öğrencilerin matematik hakkındaki inançlarının sınıf düzeyi ve matematik başarısı açısından farklı olduğunu göstermiştir. Ancak cinsiyete göre MİA’nın üç boyutunda anlamlı bir farklılık gözlenmemiştir
Macro Explanatory Factors of Turkish Tourism Companies' Stock Returns
This study examines whether the stock prices of Turkish tourism companies respond to growth in eight macro-economic variables namely, consumer price index, imports, exchange rate, consumer confidence index, oil price, money supply, foreign tourist arrivals, and monthly stock market return. By applying the Granger causality procedure, we find that growth in the consumer confidence index and imports could Granger cause tourism companies’ stock returns among eight macro factors in Turkey during the 2005 to 2013 period. After considering the structural break that occurred in 2007, the pre-break results indicate that the consumer confidence index, exchange rate, and foreign tourist arrivals could Granger cause tourism stock returns. However, the results in the post-structural break period reveal that only growths in oil prices and imports are significant
Longevity of organic pepper (Capsicum annuum L.) seeds
This study was carried out to determine seed longevity in organic and conventionally produced pepper seeds from four different pepper cultivars. Seeds were stored at 20± 2 oC with 7.5±0.5 seed moisture over 48 months. Longevity of seeds were evaluated with Ki (initial seed quality), P50 (half-viability period), σ (standard deviation of distribution of seed deaths in time), and regression coefficient values. The highest longevity was observed in ‘Corbaci’ and ‘Yaglik’ cultivars, while ‘Surmeli’ and ‘K. Dolma’ were found to have shorter longevity. P50 was 43.4 and 40.2 months for ‘Corbacı’ and 34.9 and 39.7 months for ‘Yaglık’ organic and conventional cultivars, respectively, whereas it was about 21.4 and 23.7 months in ‘K. Dolma’ and ‘Surmeli’ cultivars. Similarly, the highest σ and regression coefficient values were observed for ‘Corbaci’ and the lowest for ‘Surmeli’ cultivars. Organic and conventional pepper seed longevity was not different in the same species. Regression coefficient values were 0.043 in organic and 0.046 in conventional seeds for ‘Corbaci’. Very close values were found between the two production systems for the other cultivars too. Results indicate that organic seeds had similar longevity to conventional ones. The main differences originated from the cultivars, not from the production system
Monte Carlo study of the two-dimensional kinetic Blume-Capel model in a quenched random crystal field
We investigate by means of Monte Carlo simulations the dynamic phase
transition of the two-dimensional kinetic Blume-Capel model under a
periodically oscillating magnetic field in the presence of a quenched random
crystal-field coupling. We analyze the universality principles of this dynamic
transition for various values of the crystal-field coupling at the originally
second-order regime of the corresponding equilibrium phase diagram of the
model. A detailed finite-size scaling analysis indicates that the observed
nonequilibrium phase transition belongs to the universality class of the
equilibrium Ising ferromagnet with additional logarithmic corrections in the
scaling behavior of the heat capacity. Our results are in agreement with
earlier works on kinetic Ising models.Comment: 25 pages (APS preprint style), 13 figures, 1 tabl
Ising universality in the two-dimensional Blume-Capel model with quenched random crystal field
Using high-precision Monte-Carlo simulations based on a parallel version of
the Wang-Landau algorithm and finite-size scaling techniques we study the
effect of quenched disorder in the crystal-field coupling of the Blume-Capel
model on the square lattice. We mainly focus on the part of the phase diagram
where the pure model undergoes a continuous transition, known to fall into the
universality class of the pure Ising ferromagnet. A dedicated scaling analysis
reveals concrete evidence in favor of the strong universality hypothesis with
the presence of additional logarithmic corrections in the scaling of the
specific heat. Our results are in agreement with an early real-space
renormalization-group study of the model as well as a very recent numerical
work where quenched randomness was introduced in the energy exchange coupling.
Finally, by properly fine tuning the control parameters of the randomness
distribution we also qualitatively investigate the part of the phase diagram
where the pure model undergoes a first-order phase transition. For this region,
preliminary evidence indicate a smoothening of the transition to second-order
with the presence of strong scaling corrections.Comment: 11 pages, 13 figures, minor correction to references appearing in
Fig. 1, to be published in Phys. Rev.
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