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111.
Efe Boran Ebru Özgür Job van der Burg Meral Yücel Ufuk Gündüz Inci Eroglu 《Journal of Cleaner Production》2010
The purpose of this study was to develop a pilot scale tubular photo bioreactor (80 L) for photo fermentative hydrogen production by photosynthetic purple-non-sulfur bacterium, Rhodobacter capsulatus, operating in outdoor conditions, using acetate as the carbon source. The reactor was operated continuously in fed-batch mode for 30 days throughout December 2008 in Ankara. It was placed in a greenhouse in order to keep the temperature above freezing levels. It was found that R. capsulatus had a rapid growth with a specific growth rate of 0.025 h?1 in the exponential phase. The growth was defined with modified logistic model for long term duration. The hydrogen production and feeding started in the late exponential phase. Evolved gas contained 99% hydrogen and 1% carbon dioxide by volume. The average molar productivity calculated during daylight hour was 0.31 mol H2/(m3 h) with regard to the total reactor volume and 0.112 mol H2/(m2·day) with regard to the total illuminated surface area. It was proven that even at low light intensities and low temperatures, the acetic acid which was fed to the system can be utilized for biosynthesis, growth and hydrogen production. The overall hydrogen yield was 0.6 mole H2 per mole of acetic acid fed. This study showed that photofermentation in a pilot scale tubular photo bioreactor can produce hydrogen, even in winter conditions. 相似文献
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113.
Şeker Mehmet Emin Erdoğan Ayşegül Korkmaz Seda Dicle Küplülü Özlem 《Environmental science and pollution research international》2022,29(24):36161-36169
Environmental Science and Pollution Research - In this study, pollens were collected from 25 different locations of Northern Turkey to investigate pollution monitoring. Surface chemistry of pollen... 相似文献
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115.
Prenatal diagnosis of congenital atresia of the larynx is difficult but is possible by the findings of increased lung echogenicity and size coexisting with fetal ascites in ultrasonography. Sonographic findings may not always be typical. We report on a case of congenital laryngeal atresia diagnosed prenatally by the findings of fetal hydrops and hyperechogenic lungs. Our case presented with oligohydramnios. We also review syndromes that demonstrate laryngeal anomalies. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
116.
We have aimed at characterizing top soil samples taken in-situ from five different locations of the unregulated dumping site
in Eskişehir/Turkey for a period of six months. The study is the first attempt in the city and in Turkey, regarding particularly
the SPME (Solid Phase Microextraction Technique) analysis method utilized. A comprehensive research has been conducted to
produce critical soil data to be used for indicating current risks as well as the urgency of rehabilitating the site and establishing
a sanitary landfill in the site. Conventional physicochemical analytical methods and SPME technique were used to analyze the
samples. Physicochemical analyses were performed for determining the pH, total dried matter, volatile matter, total nitrogen,
phosphorus, macro elements and heavy metals. Meteorological data were also recorded for the same period. SPSS.10.0 statistical
program was used to determine the correlation between meteorological data and physicochemical analysis results. Mean values
were used in the correlation analyses. These data indicated that the air temperature and precipitation have significant effects
on soil characteristics. SPME, coupled with GC/MS, was used to identify eighty six volatile and semi-volatile organic compounds
contained in soil samples. The samples were extracted by headspace SPME with heating (δHS-SPME). SPME analyses were conducted
using a commercially available polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber having a film thickness of 65 μm (Supelco)
as a capture medium. The experimentally optimized headspace sampling conditions were arranged (15 min. at 50˚C) before a 30 min. sampling period. 相似文献
117.
Mesut Ural Selami Arca Gürel Nedim Örnekçi Ferhat Demirol Songül Yüce Kazim Uysal 《毒物与环境化学》2013,95(1):49-55
Metal concentrations were determined in water, sediment, and freshwater fish samples (Squalus cephalus, Barbus esocinus, and Barbus xanthopterus) collected from Karakaya Dam Lake, Turkey, to estimate the risk of human consumption and pollution. Metal concentrations differed between the species (p?0.05) even as they were living in similar habitats. Metal analyses were performed by inductively coupled plasma optical emission spectroscopy (ICP-OES). Cd and Hg were not detected in water, sediment, and fish samples. Also, Mn, Ni, and Se were not determined in water. The accumulation order of the metals were found to be Fe?>?Zn?=?Cu in water and Fe?>?Zn?>?Mn?>?Ni?>?Cu in sediment. In general, the accumulation order of elements in the tissues all of the species sampled were found as Fe?>?Zn?>?Se?>?Mn?>?Cu?>?Ni?>?Cd in muscle, Zn?>?Fe?>?Mn?>?Se?>?Cu?>?Ni?>?Cd in gills, Fe?>?Zn?>?Se?>?Mn?>?Cu?>?Ni?>?Cd in liver and gonad, and Zn?>?Fe?>?Cu?>?Mn?>?Se?>?Ni?>?Cd in kidney. It was concluded that the fish from the dam lake are not heavily burdened with metals, but they should be controlled periodically to avoid excessive intake of trace metals by humans, and to monitoring the pollution of aquatic environment. 相似文献
118.
Estimating tree bole volume using artificial neural network models for four species in Turkey 总被引:2,自引:0,他引:2
Ramazan Özçelik Maria J. Diamantopoulou John R. Brooks Harry V. Wiant 《Journal of environmental management》2010,91(3):742-753
Tree bole volumes of 89 Scots pine (Pinus sylvestris L.), 96 Brutian pine (Pinus brutia Ten.), 107 Cilicica fir (Abies cilicica Carr.) and 67 Cedar of Lebanon (Cedrus libani A. Rich.) trees were estimated using Artificial Neural Network (ANN) models. Neural networks offer a number of advantages including the ability to implicitly detect complex nonlinear relationships between input and output variables, which is very helpful in tree volume modeling. Two different neural network architectures were used and produced the Back propagation (BPANN) and the Cascade Correlation (CCANN) Artificial Neural Network models. In addition, tree bole volume estimates were compared to other established tree bole volume estimation techniques including the centroid method, taper equations, and existing standard volume tables. An overview of the features of ANNs and traditional methods is presented and the advantages and limitations of each one of them are discussed. For validation purposes, actual volumes were determined by aggregating the volumes of measured short sections (average 1 meter) of the tree bole using Smalian's formula. The results reported in this research suggest that the selected cascade correlation artificial neural network (CCANN) models are reliable for estimating the tree bole volume of the four examined tree species since they gave unbiased results and were superior to almost all methods in terms of error (%) expressed as the mean of the percentage errors. 相似文献
119.
120.
Daniel Teixidor Thanongsak Thepsonthi Joaquim Ciurana Tugrul Özel 《Journal of Manufacturing Processes》2012,14(4):435-442
This paper reports an investigation into the effects of nanosecond laser processing parameters on the geometry of microchannels fabricated from polymethylmethacrylate (PMMA). The Nd:YAG solid-state pulsed laser has a wavelength of 1064 nm and a measured maximum power of 4.15 W. The laser processing parameters are varied in a scanning speed range of 400–800 pulses/mm, a pulse frequency range of 5–11 Hz, a Q-switch delay time range of 170–180 μs. Main effects plots and microchannel images are utilized to identify the effects of the process parameters for improving material removal rate and surface quality simultaneously for laser micromachining of microchannels in PMMA polymer. It is observed that channel width and depth decreased linearly with increasing Q-switch delay time (hence average power) and increased non-linearly with higher scanning rates and not much affected by the increase in pulse frequency. 相似文献