Interval type-2 fuzzy TOPSIS method for calibration supplier selection problem: a case study in an automotive company

Arabian Journal of Geosciences - The increasing availability of 3D seismic data and well logs from Ash Shaer Area has provided fundamental new insights into the Miocene igneous activity and its...     

Effect of disturbed zone thickness on rock slope stability

Natural Hazards - Cut slope surfaces are affected by excavation activities and weathering agents. Disturbances on the surface can penetrate down to a certain depth. Slope stability analyses made on...     

Dimensionality Reduction and Classification of Hyperspectral Images Using Object-Based Image Analysis

Object-based image analysis (OBIA) has attained great importance for the delineation of landscape features, particularly with the accessibility to satellite images with high spatial resolution acquired by recent sensors. Statistical parametric classifiers have become ineffective mainly due to their assumption of normal distribution, vast increase in the dimensions of the data and availability of limited ground sample data. Despite pixel-based approaches, OBIA takes semantic information of extracted image objects into consideration, and thus provides more comprehensive image analysis. In this study, Indian Pines hyperspectral data set, which was recorded by the AVIRIS hyperspectral sensor, was used to analyse the effects of high dimensional data with limited ground reference data. To avoid the dimensionality curse, principal component analysis (PCA) and feature selection based on Jeffries–Matusita (JM) distance were utilized. First 19 principal components representing 98.5% of the image were selected using the PCA technique whilst 30 spectral bands of the image were determined using JM distance. Nearest neighbour (NN) and random forest (RF) classifiers were employed to test the performances of pixel- and object-based classification using conventional accuracy metrics. It was found that object-based approach outperformed the traditional pixel-based approach for all cases (up to 18% improvement). Also, the RF classifier produced significantly more accurate results (up to 10%) than the NN classifier.     

An Ion Chromatography Method for the Determination of Major Anions In Geothermal Water Samples

A single-column suppressed ion chromatography technique was employed for the simultaneous determination of major and trace anions in sulfaterich groundwater samples. An analytical column, a self regenerating suppressor and sodium carbonate as the eluent were used to separate the anions. Method detection limits for the anions of interest were 10.4, 15.9, 36.8, 62, 60, 61 and 67 μg l⁻¹ for F⁻, Cl⁻, NO₂⁻, Br⁻, NO₃⁻, PO₄³⁻ and SO₄²⁻ respectively. The precision of the method was tested at five different concentration levels for each anion reference sample to evaluate the effectiveness of the method for groundwater analysis. Recovery studies were performed between two successive months by adding reference samples to the geothermal groundwater and drinking water samples. Precision was also assessed as the relative standard deviation of both repeatability (within-day) and reproducibility (between-day and different concentrations) for groundwater samples. Standard deviation and RSD values of 220 groundwater samples acquired over 8 months were evaluated. The suppressed ion chromatography technique was found to be a suitable method for determining major anions in sulfate-rich geothermal water samples.     

Experimental behavior of screwed beam-to-column connections in cold-formed steel frames

In this study, a beam-to-column connection in cold-formed steel structure has been examined using self-drilling screw. An experimental study is carried out for the full-scale specimens of the connection. The beam has different thickness to determine the structural behavior of the connection. The behavior of connections is represented by their moment–rotation curve. So, this study focuses on evaluating the moment–rotation curves and whose characteristic values. The aim of the work is also to provide failure mechanism for the connection whose fastener is self-drilling screws. The failures of the connected members and screws are observed in the knee joint configuration. This was performed through cantilever tests of full-scale beam-to-column joints. Experiment results were evaluated by comparing to the results of other experiments with different combination thickness. The experimental results showed that plastic and maximum deformation decreases while maximum moment and stiffness increases when the profile thickness of the beam increased.     

Assessment of the consecutive harmful dinoflagellate blooms during 2015 in the Izmit Bay (the Marmara Sea)

A series of red tides were observed during 2015 in the Izmit Bay(the Marmara Sea) which is located in the most industrialized and populated region of Turkey. Six samplings were carried out in this area following the red tides.Nitrite-N, nitrate-N, ammonia, silica and orthophosphate concentrations were analyzed spectrophotometrically.Physicochemical conditions were measured by CTD probe. Plankton quantification was performed using counting chambers under microscopes. Prorocentrum micans was the most abundant species, except on May 14,2015, when Noctiluca scintillans was dominant. The abundance of P. micans reached average 18×10~6 ind./L on May 3, 2015 in the Karamürsel station, simultaneously with elevated levels of NH_3 and o-PO_4~(3–). The sample was also abundant in dead amphipods((72±12) ind./L) that had been covered by mucilage aggregates produced by P.micans. The highest biomass(calculated by carbon) was recorded as(268±26.0) mg/L on May 14 in the Hereke station. Beside the anthropogenic wastewater discharges, unknown sources and resuspensions caused increases in nutrient levels. After long term northeaster gusts(35 km/h for 5 d) an upwelling occurred on November 6, 2015 after wind-induced sediment resuspension. Although nutrient discharges remarkably decreased over 30 years through established wastewater treatment plants, harmful phytoplankton blooms still occur. Comparing the present results with other studies in nearby Mediterranean seas reveals that the most intense harmful dinoflagellate bloom in recent years occurred in the Izmit Bay. Therefore, additional protection measures necessary for a cleaner Izmit Bay. These incidents also demonstrate that contaminants, accumulated in sediment,may have long-lasting effects on enclosed marine ecosystems.     

Pre‐treatment of Waste Foundry Sand Via Solidification/Stabilization

This study was performed to propose a suitable treatment for waste foundry sand (WFS) before persistent disposal. It was observed that solidification/stabilization (S/S), which is the common pre‐treatment method because of its comparatively easy and inexpensive applicability, can treat WFS including dissolved organic carbon (DOC) above hazardous landfilling limits. Regular sand was partially replaced with WFS with a ratio of 0–90 wt% in order to prepare three different kinds of mortar samples, where Portland limestone cement (PLC) alone, calcium lime (CL) alone, and PLC together with CL were contained as binders. Leaching behaviors of all S/S products were analyzed according to the TS EN 12457‐4 leaching test. The treatment efficiency was assessed to reduce the DOC content to the levels under the European landfill acceptance criteria. Furthermore, heavy metals (Ni, Zn, Cr), fluoride (F^?), total dissolved solids leachability, and total organic carbon content were analyzed in order to investigate the pre‐treatment ability and to determine whether S/S products can be disposed of in a landfill site with municipal wastes or in a separate landfill site. The results showed that S/S of WFS is an efficient pre‐treatment technique before its disposal in a landfill and provides economical advantages compared to hazardous waste landfilling.     

Language change in South Africa: A geographical perspective

In the changing multi-ethnic South African society of the nineties, language planning has become a top priority on the national agenda of reform. Comprehension of the territorial dimensions of language is crucial if we are to penetrate its true cultural, economic and political effect. South Africa's language policy, as defined in the interim constitution, focuses mainly on the fact that in future the country will accommodate eleven official languages with equal status. Obviously, the nine provinces do not each have eleven official languages. A provincial legislative may, by a two-thirds majority vote, declare any of the national languages a provincial official language for the whole province or a part thereof. In the light of this it is of vital importance that the country's regional language patterns be analysed on a geographical basis. A visual and statistical representation of the geolinguistic realities in South Africa could support the planning and transformation process currently taking place at all levels of government in this multilingual country. The aim of this paper is to address the following geolinguistic issues on a national scale:

• The spatial identification of the official language distribution on a macro level;
• The time-space pattern of language change between 1980 and 1991;
• The demographic and socio-economic profile of language speakers;
• The consequences of the findings for ethno-linguistic restructuring in a post-apartheid South Africa.

The analysis of the 37 million people's first home languages in South Africa has been accomplished by utilizing an ARC/INFO Geographical Information System linked with the 374 statistical districts. Although the country is ethnically and culturally very diverse, three language groups, namely isiZulu, isiXhosa and Afrikaans, dominate the linguistic scene. Their respective distribution patterns are fairly segregated within specific regions, while their relative change patterns are substantially influenced by urbanization trends and political restructuring.