Volume XCIII, Number 15, February 22, 1974

11th International Conference of Inborn Errors of Metabolism -- AUG 29-SEP 02, 2009 -- San Diego, CAWOS: 00026894260018

The compressibility of high purity YbB2

Cataloged from PDF version of article.The compressibility and phase stability of YbB2 are investigated under high pressure using high-resolution synchrotron x-ray diffraction in a diamond anvil cell. The bulk modules of high purity YbB2 is obtained as similar to 182 GPa using the Birch-Murnaghan equation of state. The patterns measured up to 20 GPa and the pressure dependence of normalized lattice parameters, a/a(0) and c/c(0), reveal that the compressibility of YbB2 is low and fairly isotropic, and this material can be classified as a hard material. X-ray photoemission studies demonstrate that Yb in YbB2 has a mostly trivalent valence state at room temperature. Moreover, sample preparation details provide a new insight into the high purity synthesis of YbB2 at ambient pressure and moderate temperatures. The presented structural and compressibility results are in agreement with the available theoretical and experimental data on binary rare-earth borides and can serve as a reliable reference for future studies

First occurrence of the invasive alien species Polydora cornuta Bosc, 1802 (Polychaeta: Spionidae) on the coast of Greece (Elefsis Bay; Aegean Sea)

The present study reports on the occurrence of two specimens of the alien species Polydora cornutaBosc, 1802, in Elefsis Bay, the Saronikos Gulf (Aegean Sea, eastern Mediterranean). This is the firstrecord of this invasive alien species on the coast of Greece and the second report in the eastern MediterraneanSea after its first finding in Izmir Bay (on the Turkish Aegean coast). This finding enhances its distributionalpattern within the Mediterranea

Anomalous resistance overshoot in the integer quantum Hall effect

In this work we report experiments on defined by shallow etching narrow Hall bars. The magneto-transport properties of intermediate mobility two-dimensional electron systems are investigated and analyzed within the screening theory of the integer quantized Hall effect. We observe a non-monotonic increase of Hall resistance at the low magnetic field ends of the quantized plateaus, known as the overshoot effect. Unexpectedly, for Hall bars that are defined by shallow chemical etching the overshoot effect becomes more pronounced at elevated temperatures. We observe the overshoot effect at odd and even integer plateaus, which favor a spin independent explanation, in contrast to discussion in the literature. In a second set of the experiments, we investigate the overshoot effect in gate defined Hall bar and explicitly show that the amplitude of the overshoot effect can be directly controlled by gate voltages. We offer a comprehensive explanation based on scattering between evanescent incompressible channels.Comment: 7 pages and 5 figure

Korištenje GIS tehnika za modeliranje širenja antropogene buke koju stvara motorna pila prilikom sječe šuma

Noise is an environmental pollution that negatively affects human health and reduces the performance of employees. Forest harvesting activities are one of the working environments where noise effect is intense. The most common equipment used in forest operations is chainsaw whose noise affects not only the operator but also the wildlife in the territory. The noise maps showing noise propagation can be effectively used in evaluating and controlling the noise effects. In this study, it was aimed to measure the anthropogenic noise levels ​​resulting from the chainsaw used in tree felling and to map its noise propagation with SPreAD-GIS (System for Prediction of Acoustic Detectability) which is a GIS (Geographical Information Systems) based noise prediction software. The study was conducted in Karacabey Flooded Forest within the city of Bursa in Türkiye. The results indicated that the average noise level from the chainsaw was above the danger limit (90 dBA) that causes increased physiological reactions and headache on the workers. According to the noise propagation map, the noise exposure of the employees exceeded the warning limit (85 dBA) and the maximum noise level was 95.96 dBA during the harvesting activity. In some parts of the study area, the noise level was 45 dBA or above, causing negative effects on bird species. It can be concluded that the noise maps can be effectively used to determine noise propagation generated by a chainsaw and evaluate the noise effects on the operators and as well as on the bird species in the perimeter.Buka je onečišćenje okoliša koje negativno utječe na zdravlje ljudi i smanjuje učinak zaposlenika. Aktivnosti sječe šuma jedno su od radnih okruženja u kojima je buka intenzivna. Najčešća oprema koja se koristi u šumarstvu je motorna pila, čija buka utječe ne samo na operatera, već i na divlje životinje na teritoriju. Karte buke koje prikazuju širenje buke mogu se učinkovito koristiti za procjenu i kontrolu učinaka buke. U ovome radu cilj je bio izmjeriti razine antropogene buke nastale radom motorne pile koja se koristi pri sječi stabala i mapirati širenje buke pomoću SPreAD-GIS programa (Sustav za predviđanje akustične detektabilnosti) čija se procjena širenja buke temelji na GIS-u (Geografski informacijski sustav). Istraživanje je provedeno u poplavnoj šumi Karacabey na području grada Bursa u Turskoj. Rezultati su pokazali da je prosječna razina buke motorne pile iznad granice opasnosti (90 dBA), što uzrokuje pojačane fiziološke reakcije i glavobolju radnika. Prema karti širenja buke, izloženost zaposlenika buci prešla je granicu upozorenja (85 dBA), a maksimalna razina buke tijekom rada iznosila je 95,96 dBA. U nekim dijelovima istraživanog područja razina buke iznosila je 45 dBA ili više, što je uzrokovalo negativan utjecaj na vrste ptica. Može se zaključiti da se karte buke mogu učinkovito koristiti za određivanje širenja buke koju stvara motorna pila i procjenu učinaka buke na operatere, kao i na vrste ptica u okruženju

Application of the bentix index in assessing ecological quality of hard substrata: a case study from the Bosphorus Strait, Turkey

In this paper, a biotic index (Bentix) has been used for the assessment of ecological quality status of shallow water hard substrate benthic ecosystems affected by coastal sewage discharges in the Bosphorus Strait. A significant difference was observed between the control and the discharge stations with regard to Bentix values (Mann-Whitney U Test, p=0.002) and ecological quality status of the discharge stations was worse than that of controls. The index values revealed that sewage discharges caused serious disturbance in macrozoobenthic communities in the area investigated. Although so far it has been used for soft bottom communities, Bentix (with some species scoring modifications) also appeared to work successfully in hard substrates, at least for the present study

On the Occurrence and Established Populations of the Alien Polychaete Polydora cornuta Bosc, 1802 (Polychaeta: Spionidae) in the Sea of Marmara and the Bosphorus Strait (Turkey)

The present paper reports the first occurrence of Polydora cornuta in the Bosphorus Strait and its finding in a new locality in the Sea of Marmara, providing a link with its Aegean and Black Sea populations. The probable vector for the introduction of P. cornuta into the Sea of Marmara is shipping through the Dardanelles Strait. Both soft and hard-bottom populations were examined and the importance and prevalence of this species within the native macrozoobenthic communities were elucidated. Its abundance ranged between 40 and 3390 ind.m-2 (mean:1320 ±1199.45 SD) and its percent contribution to the total faunal populations ranged between 3.31 and 75.56 (mean:27.79 ±25.00 SD) in the Sea of Marmara softbottom community. During the sampling period, P. cornuta contributed little to the total faunal abundance of the hard-bottom communities in the Bosphorus Strait. Its mean abundance in the hard substrate ranged between 8.33 and 1000 ind.m-2 (mean:117.36 ±279.73 SD) and its percent contribution to the total faunal populations ranged between 0.02 and 21.86 (mean:2.07 ±6.25 SD). The role of this invasive species in the soft-bottom macrobenthic community at an organically enriched site examined in the Sea of Marmara is highlighted, and a comparison with Aegean Sea populations of the species is also included

Testing justification for segment based relevant product market definition in merger control: Evidence from Turkey

In this paper, we aim to investigate whether different segments of beer products can constitute a separate relevant product market within the framework of competition law. This question gained importance when the merger between Anheuser-Busch InBev and SABMiller became subject to a Phase II investigation by the Turkish Competition Authority in March 2016, which ultimately ended with an unconditional clearance decision, based on an intact "beer" market, recognizing that the relevant product market regarding beer brands in Turkey must be wider than the premium segment. To answer the research question above concerning relevant product market definition, we implement a Hypothetical Monopolist Test in two steps. In the first step, the aggregate price elasticity of demand for the premium segment is estimated econometrically by using a nested logit demand model. This model tests whether products in the same group are closer substitutes than products in different groups. We conclude that the correlation of beers within the same group is not statistically significant. Since the data in our study are obtained at the retail level, the price elasticity of demand at the brewer level is derived from the estimate at the retailer level by using very conservative assumptions with regard to the passthrough rates. In the second step, the hypothetical monopolist test is implemented by using the critical elasticity which is calculated by using the profit margins for the premium beer segment at brewer/supplier level under both 5 percent and 10 percent SSNIP. It is seen that the actual elasticity of demand for the premium segment is larger than the critical elasticity (in absolute value) under both scenarios. These findings show that the relevant product market regarding beer brands in Turkey must be wider than the premium segment. © The Author 2017. Published by Oxford University Press. All rights reserved