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1

Influence of Bi on dielectric properties of GaAs1−xBix alloys

Ulutas K., Yakut S., Bozoglu D., Deger D., Arslan M., Erol A.

Materials Science Poland

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2019

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Vol. 37, No. 2

244--248

EN

Pure GaAs and GaAs1−xBix alloys with different Bi ratios (1 %, 2.5 %, 3.5 %) fitted with silver contacts were measured with a dielectric spectroscopy device. Dielectric characterization was performed at room temperature in the frequency range of 0.1 Hz to 1 MHz. GaAs exhibits three relaxation regions corresponding to space-charge, dipolar and ionic polarizations in sequence with increasing frequency while GaAs1−xBix samples show only a broad dipolar polarization in the same frequency range. This result proves the filling of the lattice with Bi through making a new bonding reducing the influence of ionic polarization. This finding supports the previous results concerning optical properties of GaAs1−xBix, presented in the literature.

2

Seasonal variations, environmental parameters, and standing crop assessment of benthic foraminifera in eastern Bahrain, Arabian Gulf

Arslan M., Kaminski M. A., Tawabini B. S., Ilyas M., Babalola L. O., Frontalini F.

Geological Quarterly

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2016

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Vol. 60, No. 1

26--37

EN

Living benthic foraminifera in a relatively unpolluted site offshore Bahrain in the Arabian Gulf, were studied to determine the seasonal variability of their populations, as well as environmental parameters that may affect their distribution. The maximum foraminiferal density was observed during winter with the assemblages primarily dominated by rotaliids and secondarily by miliolids. The high population is attributed to an increased number of juveniles. A relationship between sediment grain size and the foraminiferal density reveals that juveniles were most abundant on coarse-grained sandy substrate and less abundant on fine-grained substrates. In spring, the foraminiferal density decreased, and the lowest values were observed during summer. The population increased again in autumn with highest juvenile/adult ratios. Moreover, results of relative abundance and species consistency show that Ammonia and Glabratellina are consistent from the shallowest to the deepest station, whereas miliolids occurred only at deeper stations. The numbers of peneroplidae and Elphidium also increased along the depth transect. Environmental characterization reveals that although the site is subject to eutrophication caused by nitrates and sulfates, pollution caused by hydrocarbons and heavy metals is not significant. The assessment of 63 heavy metals showed that none of the metals had concentrations that exceed internationally accepted norms [the devised level of Effect Range-Low], but with high concentration of strontium. The lack of a significant environmental effect of heavy metals is confirmed by the Foraminiferal Abnormality Index of <2%. Likewise, no hydrocarbon contamination was detected in the water or sediment samples. We conclude that the site in Bahrain is not yet adversely affected by human development, and therefore can provide baseline information for future comparison and assessment of foraminiferal assemblages in contaminated zones of the Arabian Gulf.

3

Patterns of fish communities along a mountain river : the Upper Coruh river (Turkey)

Yildirim A., Arslan M., Pegg M.

Polish Journal of Ecology

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2008

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Vol. 56, nr 4

731-736

EN

Distribution of fish communities along the submountain river (upper Coruh River, Northeastern of Turkey) was assessed to evaluate course of the longitudinal pattern in fish species diversity. The watershed area of Coruh Basin is 21.000 km[^2], river length 376 km and it flows into Black Sea in northeastern Turkey at average discharge of 149 m[^3] s[^-1] (range: 45.2.1215 m[^3] s[^-1]). Fixed-site electrofishing sampling at five sites located 15.210 km from river source at 2100-950 m a.s.l (Q values ranged 5.200 m[^3] s[^-1]) was conducted from March 2001 to March 2002. A total of 12 species were collected. Number of species (8-10) did not differ among sites suggesting no longitudinal changes, but Shannon-Wiener biodiversity index (H') increased downstream from 1.23 to 1.82. Two distinct fish assemblages were identified. Most abundant species were Leuciscus cephalus and Alburnoides bipunctatus. Both Oncorhynchus mykiss and Cyprinus carpio collected rarely are exotic fishes for Coruh River.

4

Effects of Amount and Application Time of Saline Water on Fibre Quality Characteristics of Cotton

Odemis B., Arslan M.

Fibres & Textiles in Eastern Europe

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2005

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Vol. 13, no. 3 (51)

11--15

EN

Compared with good quality water, the use of saline water increases the amount of water used for crop growth. An increased amount of saline water affects fibre quality. A field study was conducted to determine the effects of amount and application time of saline water on the fibre characteristics of cotton. Irrigation was carried out by a line-source sprinkler, which allowed the crop to be irrigated at different levels. All of the fibre characteristics measured were significantly and negatively affected by the saline water applied at VGP and FBF, whereas at BO, strength and length were the only fibre characteristics that were significantly and positively affected by the saline water applied. Osmotic potential (Ψ) at different growth stages and mean seasonal osmotic potentials significantly by the second power affected trash, trash area and ginning out-turn. The results showed that the saline water amountthe , soil osmotic potential and evapotranspiration (ET) had a squaring effect on fibre characteristics.

PL

W porównaniu z wodą dobrej jakości, stosowanie wody słonej powoduje zwiększenie ilości zużywanej wody podczas wzrostu bawełny. Zwiększenie ilości słonej wody wpływa na jakość włókna. Przeprowadzono badania pola uprawnego bawełny, określając wpływ ilości słonej wody i czasu jej stosowania na charakterystykę jakościową bawełny. Pole nawadniano za pomocą zraszaczy, co pozwoliło na nawodnienie z różną intensywnością. Zastosowanie słonej wody w okresie wegetatywnego wzrostu oraz podczas kwitnienie i tworzenia się torebek nasiennych w istotny i negatywny sposób wpłynęło na wszystkie zmierzone właściwości włókien. W czasie otwierania się torebek nasiennych oceniono jedynie wpływ słonej wody na wytrzymałość i długość włókien i okazało się, iż jest on istotny i pozytywny. Potencjał osmotyczny (Ψ) w różnych stadiach wzrostu oraz znaczne średnie sezonowe potencjały osmotyczne, spowodowane zanieczyszczeniem pola i odziarnianiem bawełny były drugim istotnym czynnikiem. Wyniki badań pokazują, iż ilość słonej wody, osmotyczny potencjał gleby oraz ewapotranspiracja (ET) mają wpływ na właściwości włókien.