Stratigraphy, geochemistry, and petrology of the Upper Cretaceous volcanic arc sequence north of Istanbul, Pontides, NW Turkey

<p>Upper Cretaceous arc-related volcanic and volcanoclastic units overlying the Paleozoic sedimentary rocks of the Istanbul Zone are a key unit related to the opening of the Black Sea as a back-arc basin. They formed as a result of north dipping subduction of the Neo-Tethys Ocean beneath Laurasia. We studied the Upper Cretaceous volcanic units north of Istanbul along several stratigraphic sections, and present new geochemical data from the volcanic rocks in order to understand Cretaceous geodynamic evolution of the İstanbul Zone.</p><p>The Upper Cretaceous  volcanic units north of Istanbul are divided into two formations. At the base there is a fore-arc turbidite succession,the İshaklı Formation, which is made up of volcaniclastic sandstone, shale, marl, tuff, debris flow horizons and epiclastic rocks of Turonian age. The İshaklı Formation is conformably overlain by the volcanoclastics,  tuffs, andesite and basalt lavas and agglomerates- the Riva Formation, which represents the arc/ intra-arc series.</p><p>Geochemically, basalts and basaltic andesites of the Riva Formation are low K calc-alkaline to medium-high K calc-alkaline and with magnesium numbers ranging from 32.6% to 51.5% Primitive mantle normalized spider diagram of trace elements show  enrichment in LILE elements (K, Rb, Sr, Cs, Ba, Th and U) and depletion in HFS elements ( Nb,Ta and Ti) . The high ratio of LILE/ HFS and negative Nb-Ta anomalies indicate that the volcanism evolved in subduction setting. Chondirite-normalized REE pattern display slight negative Eu anomalies and the La/Yb ratios of the samples range between 2,76 and 4,89. Our new geochemical, stratigraphical and the regional geological data suggest that north of Istanbul there was a transition from fore-arc deposition to arc volcanism during the Late Cretaceous opening of the Western Black Sea.  Considering the whole Pontide – Sredna-Gora Upper Cretaceous magmatic arc, it can be stated that calc-alkaline volcanism developed in relation to northward subduction of the Neo-Tethys oceanic lithosphere during the Turonian, and may have passed into high-K calc alkaline and shoshonitic magmatism as a result of the progressive extentional tectonism during the Campanian.</p>

Spatial downscaling of radar-derived rainfall field by two-dimensional wavelet transform

Downscaling of rainfall fields, either as images or products of global circulation models, have been the motive of many hydrologists and hydro-meteorologists. The main concern in downscaling is to transform high-resolution properties of the rainfall field to lower resolution without introducing erroneous information. In this paper, rainfall fields obtained from Next Generation Weather Surveillance Radar (NEXRAD) Level III were examined in the wavelet domain which revealed sparsity for wavelet coefficients. The proposed methodology in this work employs a concept named Standardized Rainfall Fluctuation (SRF) to overcome the sparsity of rainfall fields in wavelet domain which also exhibited scaling behaviors in a range of scales. SRFs utilizes such scaling behaviors where upscaled versions of the rainfall fields are downscaled to their actual size, using a two-dimensional discrete wavelet transform, to examine the reproduction of the rainfall fields. Furthermore, model modifications were employed to enhance the accuracy. These modifications include removing the negative values while conserving the mean and applying a non-overlapping kernel to restore high-gradient clusters of rainfall fields. The calculated correlation coefficient, statistical moments, determination coefficient and spatial pattern display a good agreement between the outputs of the downscaling method and the observed rainfall fields.

A BCI Gaze Sensing Method Using Low Jitter Code Modulated VEP

Visual evoked potentials (VEPs) are used in clinical applications in ophthalmology, neurology, and extensively in brain–computer interface (BCI) research. Many BCI implementations utilize steady-state VEP (SSVEP) and/or code modulated VEP (c-VEP) as inputs, in tandem with sophisticated methods to improve information transfer rates (ITR). There is a gap in knowledge regarding the adaptation dynamics and physiological generation mechanisms of the VEP response, and the relation of these factors with BCI performance. A simple, dual pattern display setup was used to evoke VEPs and to test signatures elicited by non-isochronic, non-singular, low jitter stimuli at the rates of 10, 32, 50, and 70 reversals per second (rps). Non-isochronic, low-jitter stimulation elicits quasi-steady-state VEPs (QSS-VEPs) that are utilized for the simultaneous generation of transient VEP and QSS-VEP. QSS-VEP is a special case of c-VEPs, and it is assumed that it shares similar generators of the SSVEPs. Eight subjects were recorded, and the performance of the overall system was analyzed using receiver operating characteristic (ROC) curves, accuracy plots, and ITRs. In summary, QSS-VEPs performed better than transient VEPs (TR-VEP). It was found that in general, 32 rps stimulation had the highest ROC area, accuracy, and ITRs. Moreover, QSS-VEPs were found to lead to higher accuracy by template matching compared to SSVEPs at 32 rps. To investigate the reasons behind this, adaptation dynamics of transient VEPs and QSS-VEPs at all four rates were analyzed and speculated.

Pre-pottery Neolithic age spatial planning: The typo-morphology of the first urbanisation with reference to three Akarçay Tepe plaques

<p><strong>Abstract.</strong> Every civilisation, based on its socioeconomic relations, designs its land regime by using a cadastral system, plans the ways in which its land will be used, and present these through maps or spatial plans. Akarçay Tepe Lined and Marked Limestone Plaques, the use reasons of which are unknown by the archaeology discipline, were originally found during excavations and are on exhibition in Şanlıurfa Museum in Turkey. The plaques have been dated back to the Pre-Pottery Neolithic Age.</p><p>This paper aims to present what Plaques from Akarçay Tepe actually refer to and the methodology of determination. It originates from a research study which was commenced in 2017 on the basis of the propositions that these Plaques are in fact, maps and spatial plans showing the land regime and topography at the time they were made. Spatial dimensions of three Akarçay Tepe plaques with reference to technical features are examined on the foundation of the urban planning discipline. The objective here is to make it possible to adjust the findings of an archaeological excavation and to make a contribution as a proposed alternative method for the evaluation of these findings.</p><p>The three plaques for which research permission was granted were not related to the cadastral arrangements of Akarçay Tepe, but provide indications of the patterns of other settlements: Birecik, Yeşilözen, and Nizip. The plaques are spatial plans drawn to 1&amp;thinsp;:&amp;thinsp;1000 scale displayed in the form of a 3-D model map. The plaques show the settlement topography, land regime, land use decisions, boundaries of control and settlement and agricultural support systems. Plaques, besides agricultural land pattern display the first typo-morphology of urbanisation of the Pre-Pottery Neolithic Age.</p>

Lifestyle as a Resource for Re-Structuring Romani Urban Housing

Solving settlement and likewise housing problems of socially vulnerable Romani in Belgrade and Serbia still has not found the right design approach. In contemporary plural society, it is a process of interaction of theoretical and practical tryouts set beyond the disciplinary limits. Insufficient awareness on Romani lifestyle elaborated in Romanypen, i.e. the Romani cultural system causes a lack of methods, techniques and tools to choose from and develop for this untangled complex problem. The intent of this article is to show that a collective lifestyle represents the essence needed for developing adequate design decisions of Romani settlements, thus fulfilling the potential for improving adequate housing solutions. The study starts on the assumption that in Romani settlements there is a strongly rooted relation between spatial and social level that enables an understanding of what this cultural group produces as its own place. The urban pattern of Romani settlements do not have an institutionally imposed organization; they are formed by the Romani themselves, by reflex rooted in needs of everyday life activities and consequently organized and built through inherited knowledge and skills. The subject of this study is aimed at recognizing and thus establishing spatial expressions of the Romani collective lifestyle in three types of Belgrade Romani settlements that, according to the differences in their inner habitational pattern, display a representative model. It is based on the field analysis of five already created and developed unplanned settlements in Belgrade through observing and residing within them and by talking and questioning to their residents. This study shows that the key to understanding existing urban and architectural patterns, as well as the potential for future design actions lies in reading out the processes of everyday life. Then, it demonstrates a tool that has a potential to divert previous housing politics towards a revitalization of design in relation to social profiles specificities. At the end, the study opens a path to creating adequate architectural and urban parameters for housing care in accordance to the lifestyle acceptable for each and every socially perceptible group.

PD Characteristics in Transformer Oil under AC Condition

Partial discharge (PD) detection is a technique widely used for high voltage equipment insulation condition assessment. The metal protrusion is a situation that often appear in transformer. Metal protrusion will cause the electric field concentration and lead to partial discharge. In this paper, PD characteristics in transformer oils are examined under AC conditions, using a needle-to-plane electrode system. The PD activity in transformer oil is confirmed as appearing in pulse burst form and the PD number and amplitude will increase with the applied voltage increase. The PRPD pattern display behavior typical of corona PD in oil.