Limits to solar cycle predictability: Cross-equatorial flux plumes

Within the Babcock-Leighton framework for the solar dynamo, the strength of a cycle is expected to depend on the strength of the dipole moment or net hemispheric flux during the preceding minimum, which depends on how much flux was present in each hemisphere at the start of the previous cycle and how much net magnetic flux was transported across the equator during the cycle. Some of this transport is associated with the random walk of magnetic flux tubes subject to granular and supergranular buffeting, some of it is due to the advection caused by systematic cross-equatorial flows such as those associated with the inflows into active regions, and some crosses the equator during the emergence process. We aim to determine how much of the cross-equatorial transport is due to small-scale disorganized motions (treated as diffusion) compared with other processes such as emergence flux across the equator. We measure the cross-equatorial flux transport using Kitt Peak synoptic magnetograms, estimating both the total and diffusive fluxes. Occasionally a large sunspot group, with a large tilt angle emerges crossing the equator, with flux from the two polarities in opposite hemispheres. The largest of these events carry a substantial amount of flux across the equator (compared to the magnetic flux near the poles). We call such events cross-equatorial flux plumes. There are very few such large events during a cycle, which introduces an uncertainty into the determination of the amount of magnetic flux transported across the equator in any particular cycle. As the amount of flux which crosses the equator determines the amount of net flux in each hemisphere, it follows that the cross-equatorial plumes introduce an uncertainty in the prediction of the net flux in each hemisphere. This leads to an uncertainty in predictions of the strength of the following cycle.Comment: A&A, accepte

Magnetic flux generation and transport in cool stars

The Sun and other cool stars harbouring outer convection zones manifest magnetic activity in their atmospheres. The connection between this activity and the properties of a deep-seated dynamo generating the magnetic flux is not well understood. By employing physical models, we study the spatial and temporal characteristics of the observable surface field for various stellar parameters. We combine models for magnetic flux generation, buoyancy instability, and transport, which encompass the entire convection zone. The model components are: (1) a thin-layer alpha-Omega dynamo at the base of the convection zone; (2) buoyancy instabilities and the rise of flux tubes through the convection zone in 3D, which provides a physically consistent determination of emergence latitudes and tilt angles; and (3) horizontal flux transport at the surface. For solar-type stars and rotation periods longer than about 10 days, the latitudinal dynamo waves generated by the deep-seated alpha-Omega dynamo are faithfully reflected by the surface distribution of magnetic flux. For rotation periods of the order of two days, however, Coriolis acceleration of rising flux loops leads to surface flux emergence at much higher latitudes than the dynamo waves at the bottom of the convection zone reach. A similar result is found for a K0V star with a rotation period of two days. In the case of a rapidly rotating K1 subgiant, overlapping dynamo waves lead to noisy activity cycles and mixed-polarity fields at high latitudes.Comment: 14 pages, 14 figures. Accepted for publication in Astronomy & Astrophysic

Características y propiedades de los ignimbritos de Bitlis y sus implicaciones ambientales

Bitlis rock is used as a construction material and comes from the lava emitted by volcanoes and their subsequent transformation into ignimbrites. This type of rocks has been characterized physically, chemi­cally, toxicologically and radioactively using different procedures including determination of the coefficient of thermal conductivity, gamma spectrometry, ultrasonic speed test, ICP masses and metal extraction. The results indicate that Bitlis rocks have an ACI greater than 1, although their content of radon is lower than other rocks of volcanic origin. Leaching of metals from these rocks indicates that Pb and Cd can provide an infiltration level in the field higher than the level permitted by TCLP and they have undesired toxicological risks. The percent­ages of extraction of other metals also point to this infiltration problem. Despite this, the material offers good qualities for usage as a building material such as its thermal coefficients.La roca Bitlis se utiliza como material de construcción y proviene de la lava emitida por los volcanes y su posterior transformación en ignimbritas. Este tipo de rocas se ha caracterizado física, química, toxicológica y radioactivamente utilizando diferentes procedimientos, incluida la determinación del coeficiente de conductividad térmica, espectrometría gamma, prueba de velocidad ultrasónica, ICP masas y extracción de metales. Los resultados indican que las rocas Bitlis tienen un ACI mayor que 1, aunque su contenido de radón es más bajo que el de otras rocas de origen volcánico. La lixiviación de metales de estas rocas indica que el Pb y el Cd pueden proporcionar un nivel de infiltración en el campo más alto que el nivel permitido por TCLP y tener riesgos toxicológicos no deseados. Los porcentajes de extracción de otros metales también apuntan a este problema de infiltración. A pesar de esto, el material ofrece buenas cualidades para su uso como material de construcción, como pueden ser sus coeficientes térmicos

Lower and Upper Bounds for Nonzero Littlewood-Richardson Coefficients

Given a skew diagram $\gamma/\lambda$, we determine a set of lower and upper bounds that a partition $\mu$ must satisfy for Littlewood-Richards coefficients $c^{\gamma}_{\lambda,\mu}>0$. Our algorithm depends on the characterization of $c^{\gamma}_{\lambda,\mu}$ as the number of Littlewood-Richardson tableau of shape $\gamma/\lambda$ and content $\mu$ and uses the (generalized) dominance order on partitions as the main ingredient

Sustainable digital economy and trade adjusted carbon emissions: Evidence from China's provincial data

The importance of the digital economy and trade adjusted emissions is of great importance to study, especially in case of China. Since China is the leading exporter of the world and achieving high economic growth consecutively for the last 2-3 decades, this study, unlike past studies, evaluates the importance of digital economy, exports, imports and gross domestic product on trade adjusted carbon emissions for China. This is the only study that incorporates the importance of digital economy on trade adjusted carbon emissions for provincial data of China. This study determines whether the digital economy is a viable source of green economy. Research and development will simply replace a physical resource, flows through energy and transportation networks? This question is answered by using updated data, especially for digital economy. This study uses panel data for the Chinese provinces to investigate the impact of the digital economy in limiting CO2 emissions, taking into account GDP, exports and imports as control variables. Using method of moments quantile regression, we find a negative impact of digital economy and exports on consumption-based carbon emissions. Moreover, we find that GDP, and imports amplify consumption-based carbon emissions. © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group

Generalized four-point characterization method for resistive and capacitive contacts

In this paper, a four-point characterization method is developed for resistive samples connected to either resistive or capacitive contacts. Provided the circuit equivalent of the complete measurement system is known including coaxial cable and connector capacitances as well as source output and amplifier input impedances, a frequency range and capacitive scaling factor can be determined, whereby four-point characterization can be performed. The technique is demonstrated with a discrete element test sample over a wide frequency range using lock-in measurement techniques from 1 Hz - 100 kHz. The data fit well with a circuit simulation of the entire measurement system. A high impedance preamplifier input stage gives best results, since lock-in input impedances may differ from manufacturer specifications. The analysis presented here establishes the utility of capacitive contacts for four-point characterizations at low frequency.Comment: 21 pages, 10 figure

BACK TO THE YEAR WHEN IT ALL STARTED: LOCAL DETERMINANTS OF PARTY PREFERENCES IN 2002 TURKISH ELECTIONS

Publisher's Versio

Duygusal Zekâ Özelliği Ölçeği–Kısa Formu: Geçerlik ve Güvenirlik Çalışması

Bu çalışmanın amacı, Petrides ve Furnham (2000a, 2001) tarafından geliştirilen Duygusal Zeka Özelliği Ölçeği–Kısa Formu’nun (DZÖÖ-KF) Türkçe versiyonunun geçerlik ve güvenirliğinin incelenmesidir. Çalışma 464 üniversite öğrencisi üzerinde yürütülmüştür. Ölçeğin dil geçerliği ve eşdeğerliği İngilizce ve Türkçe formlardan elde edilen puanlar arasındaki pozitif korelasyonla desteklenmiştir. Ölçeğin yapı geçerliğini incelemek için yapılan Açıklayıcı Faktör Analizi sonucunda, 20 maddeden oluşan dört faktörlü bir yapı elde edilmiştir. Elde edilen bu yapının örneklem verisine iyi uyum gösterip göstermediğini anlamak amacıyla yürütülen Doğrulayıcı Faktör analizi sonuçları ise ölçeğin uygulandığı örnekleme uyumunun iyi olduğunu göstermiştir. DZÖÖ-KF’nun iç tutarlılık güvenirlik katsayısı ölçeğin tamamı için .81, test-tekrar test güvenirlik katsayısı ise .86 olarak bulunmuştur. Bu sonuçlar DZÖÖ-KF’nun Türkçe formunun geçerli ve güvenilir bir ölçme aracı olduğunu göstermektedir.Bu çalışmanın amacı, Petrides ve Furnham (2000a, 2001) tarafından geliştirilen Duygusal Zeka Özelliği Ölçeği–Kısa Formu’nun (DZÖÖ-KF) Türkçe versiyonunun geçerlik ve güvenirliğinin incelenmesidir. Çalışma 464 üniversite öğrencisi üzerinde yürütülmüştür. Ölçeğin dil geçerliği ve eşdeğerliği İngilizce ve Türkçe formlardan elde edilen puanlar arasındaki pozitif korelasyonla desteklenmiştir. Ölçeğin yapı geçerliğini incelemek için yapılan Açıklayıcı Faktör Analizi sonucunda, 20 maddeden oluşan dört faktörlü bir yapı elde edilmiştir. Elde edilen bu yapının örneklem verisine iyi uyum gösterip göstermediğini anlamak amacıyla yürütülen Doğrulayıcı Faktör analizi sonuçları ise ölçeğin uygulandığı örnekleme uyumunun iyi olduğunu göstermiştir. DZÖÖ-KF’nun iç tutarlılık güvenirlik katsayısı ölçeğin tamamı için .81, test-tekrar test güvenirlik katsayısı ise .86 olarak bulunmuştur. Bu sonuçlar DZÖÖ-KF’nun Türkçe formunun geçerli ve güvenilir bir ölçme aracı olduğunu göstermektedi

Enhanced topical delivery of dexamethasone by β-cyclodextrin decorated thermoresponsive nanogels

Highly hydrophilic, responsive nanogels are attractive as potential systems for the topical delivery of bioactives encapsulated in their three-dimensional polymeric scaffold. Yet, these drug carrier systems suffer from drawbacks for efficient delivery of hydrophobic drugs. Addressing this, β-cyclodextrin (βCD) could be successfully introduced into the drug carrier systems by exploiting its unique affinity toward dexamethasone (DXM) as well as its role as topical penetration enhancer. The properties of βCD could be combined with those of thermoresponsive nanogels (tNGs) based on dendritic polyglycerol (dPG) as a crosslinker and linear thermoresponsive polyglycerol (tPG) inducing responsiveness to temperature changes. Electron paramagnetic resonance (EPR) studies localized the drug within the hydrophobic cavity of βCD by differences in its mobility and environmental polarity. In fact, the fabricated carriers combining a particulate delivery system with a conventional penetration enhancer, resulted in an efficient delivery of DXM to the epidermis and the dermis of human skin ex vivo (enhancement compared to commercial DXM cream: ∼2.5 fold in epidermis, ∼30 fold in dermis). Furthermore, DXM encapsulated in βCD tNGs applied to skin equivalents downregulated the expression of proinflammatory thymic stromal lymphopoietin (TSLP) and outperformed a commercially available DXM cream

PowerPoint Öğretim Materyalleri ile Somut Öğretim Materyallerin Öğrenme Etkililiği Açısından Karşılaştırılması

The purpose of this study is to compare the 6 th grade learning environments of Mathematics courses in which PowerPoint materials and concrete materials are used. More specifically, this research aims to determine whether there is a difference between employing the above mentioned material types in terms of students’ learning levels. An experimental model with pretest-posttest comparison group was used and randomly formed three independent groups were compared with respect to learning levels. A total of 92 sixth grade elementary students participated in the study in the 2010-2011 academic year. The concrete teaching materials in the study included number scales and equation models that are specific to mathematics education and materials that are used in daily life such as sugar cube, purse, crackers or screws that are not specific to mathematics education. PowerPoint materials, on the other hand, included representations such as drawing, picture and animation and also presentations involving verbal information. Two tests that are composed of multiple-choice and open-ended questions were administered in order to measure students’ learning levels. After 10 hours of instruction, there were statistically significant increases in students’ learning in all the three groups. However, no significant difference was found among the groups in terms of their learning levels.Bu araştırmayla ilköğretim 6. sınıf matematik dersinde somut materyallerin kullanıldığı öğretim ile temsili gösterimlerin yer aldığı PowerPoint materyallerinden yararlanılan öğretim arasında, diğer taraftan sözü edilen materyal türlerinin birlikte kullanıldığı öğretim ile sadece birinin kullanıldığı öğretim arasında öğrenme düzeyi açısından farklılık olup olmadığının belirlenmesi amaçlanmıştır. Araştırmada, öntest-sontest karşılaştırma gruplu deneysel model kullanılmış ve materyal türlerinin etkisini ortaya koymak için rastlantısal olarak oluşturulmuş üç bağımsız grup öğrenme düzeyleri açısından karşılaştırılmıştır. Bu araştırmaya 2010-2011 eğitim-öğretim yılında bir ilköğretim okulunun altıncı sınıflarına kayıtlı 92 öğrenci katılmıştır. Araştırmadaki somut öğretim materyalleri, matematik öğretimine özgü olan sayı pulları ya da eşitlik modelleri gibi materyalleri, ayrıca matematiğe özgü olmayan ancak öğretim materyali olarak kullanılabilecek şeker, kese, kraker ya da vida gibi günlük yaşam gereçlerini kapsamaktadır. PowerPoint öğretim materyalleri ise resim, çizim ve animasyon gibi temsili gösterimler ile sözel bilgilerin yer aldığı sunular olarak hazırlanmıştır. Araştırmada öğrencilerin öğrenme düzeyini ölçmek amacıyla çoktan seçmeli ve açık uçlu olmak üzere iki ayrı test uygulanmıştır. Araştırmanın üç farklı öğretim ortamında materyal kullanımına dayalı olarak yürütülen 10’ar ders saati sonucunda öğrenme düzeyi açısından gruplarda istatistiksel olarak anlamlı bir artış belirlenmiştir. Ancak deney grupları arasında öğrenme düzeyi açısından istatistiksel olarak anlamlı bir farklılık bulunmamıştır