Advection in photodissociation regions and its effects on the intensities of rotational lines of H(_2)O

A parameter based study has been carried out in order to investigate advection in photodissociation regions (PDRs) by using plane-parallel, semi-infinite assumption. The PDR material has been assumed to be advected from the molecular cloud towards the cloud surface with an initial flow velocity of 1 km s(^-1). The flow velocity, number density and mass density of the gas have been computed self-consistently as a function of visual extinction A(_u). The total cloud size has been assumed to be A(_u) = 10 mag. The models have been constructed for the radiation and density parameters, x = 10, 10(^3), 10(^5) with respect to Draine field and n(_H) = 10(^4), 10(^5), 10(^6) cm(^-3) respectively. In addition to 9 models characterized by these parameters, another model with X = 10(^2) and n (_H) = 10(^4) cm (^-3) has been studied in order to compare the results to the previously obtained by Bergin et al. (2003). The rotational line intensities of 0-H(_2)O and p-H(_2)O have been computed. The effects of advection in PDR structure, abundance profiles and line intensities of H(_2)O have been investigated. The lower density, lower radiation models among the models studied have been found to be effected by advection, significantly. H(_2)O abundance profile has been found to be effected by advection even in the models in which the PDR structure and the location of H/H(_2) transition zone are the least effected compared to the other models. The intensity of o-H(_2) O have been found to be sensitive to the order of magnitude of the flow velocity. It is concluded that the comparison of these results to the data from future observations with Herschel HIFI can provide information about the characteristics of the flow in nonequilibrium PDRs. This thesis includes observational work of depletion of NO in pre-protostellar cores, L1544 and L183. NO has been found to show depletion characteristics intermediate between the C-containing and N-containing species

Soluble and insoluble-bound phenolics and antioxidant activity of various industrial plant wastes

The potential of selected industrial food wastes from juice and nut production including apple peel, apple pomace, pomegranate peel, pomegranate seed, chestnut shell, and black carrot pomace as resources for natural antioxidants was investigated. Soluble free and insoluble-bound phenolics were extracted from the wastes and analyzed for total phenolic and flavonoid contents, phenolic profile and antioxidant activity. Total phenolic and total flavonoid contents of wastes were positively correlated with their antioxidant activity. The highest total phenolic and antioxidant activity were determined in soluble fraction of pomegranate peel due to a significant amount of punicalagin derivatives. Pomegranate peel and seed had the most phenolics and flavonoids in soluble form while other wastes had more than 45% of total phenolics in insoluble-bound form. Chestnut shell showed more antioxidant activity in insoluble-bound fraction compared to that of its soluble fraction. These findings showed that not only soluble but also an insoluble-bound fraction of the industrial wastes has good potential for valorization as a source of natural antioxidants

Automatic and semi-automatic extraction of curvilinear features from SAR images

Extraction of curvilinear features from synthetic aperture radar (SAR) images is important for automatic recognition of various targets, such as fences, surrounding the buildings. The bright pixels which constitute curvilinear features in SAR images are usually disrupted and also degraded by high amount of speckle noise which makes extraction of such curvilinear features very difficult. In this paper an approach for the extraction of curvilinear features from SAR images is presented. The proposed approach is based on searching the curvilinear features as an optimum unidirectional path crossing over the vertices of the features determined after a despeckling operation. The proposed method can be used in a semi-automatic mode if the user supplies the starting vertex or in an automatic mode otherwise. In the semi-automatic mode, the proposed method produces reasonably accurate real-time solutions for SAR images

Government Supported Export Credit: United States Competitiveness

67-70A biosensor for the specific determination of uric acid in urine was developed using urate oxidase (EC 1.7.3.3) in combination with a dissolved oxygen probe. Urate oxidase was immobilized with gelatin by means of glutaraldehyde and fixed on a pretreated teflon membrane to serve as enzyme electrode. The electrode response was maximum when 50 mM glycine buffer was used at <i style="mso-bidi-font-style: normal">pH 9.2 and 35°C. The enzyme electrode response depends linearly on uric acid concentration between 5- 40 μM with a response time of 5 min. The enzyme electrode is stable for more than 2 weeks and during this period over 35 assays were <span style="font-size:14.0pt; font-family:HiddenHorzOCR;mso-bidi-font-family:HiddenHorzOCR">performed.   </span

Applications of soft computing methods in geodesy

Bu &ccedil;alışmada Yapay Sinir Ağları (YSA) ve Bulanık &Ccedil;ıkarım Sistemleri (B&Ccedil;S) jeodezinin en &ouml;nemli problemlerinden bazılarının &ccedil;&ouml;z&uuml;m&uuml; i&ccedil;in kullanılmıştır. Bu problemler sırayla, Yer yuvarı gravite alanının modellenmesi ve de GPS/Nivelman &ouml;l&ccedil;&uuml;lerinden geoid y&uuml;zeyinin belirlenmesidir. Gravite alanı modellemesi i&ccedil;in GRACE (Gravity Recovery And Climate Experiment) uydu gravimetre verileri,GPS/Nivelman geoidi i&ccedil;in ise İzmir metropolitan GPS nirengi ağında yapılan GPS ve nivelman &ouml;l&ccedil;&uuml;lerinden t&uuml;retilmiş geoid y&uuml;kseklikleri bilinen kontrol noktaları kullanılmıştır. Her iki uygulama sonucunda esnek hesaplama y&ouml;ntemlerinin, &ouml;zellikle girdi-&ccedil;ıktı sistemleri şeklinde tanımlanan jeodezik problemlerin &ccedil;&ouml;z&uuml;m&uuml; i&ccedil;in uygun y&ouml;ntemler olduğu sonucuna varılmıştır.&nbsp;&nbsp; &nbsp;Anahtar Kelimeler: B&Ccedil;S, geoid,GRACE, gravite alanı,YSA.Soft computing methods such as artificial neural networks (ANN) and fuzzy inference systems (FIS) have been widely used methods in various science and engineering fields. As the backgrounds of these methods are not very old, they have shown a rapid development with the improvements in computer systems and computation techniques. Their use in geodesy is quite new. In this study, both ANN and FIS have been used to solve the some of the major problems in geodesy. These problems are modelling of Earth&rsquo;s gravity field and the determination of geoid surface from GPS/Levelling. For gravity field modeling, GRACE (Gravity recovery And Climate Experiment) satellite gravimetry data, and for GPS/Levelling geoid control points with known geoid heights derived from GPS and levelling measurements in İzmir metropolitan GPS network were used The results from the soft methods used in computations were also compared with those from the conventional methods in terms of model quality measures like root mean square (RMS) error, mean error,&nbsp; mean absolute error, error range, correlation coefficient. Both applications&rsquo; results have concluded that soft computing methods are appropriate methods for the solution of geodetic problems especially which can be defined as input-output systems and should be considered for the solution of different other problems in geodetic science. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Keywords: ANN, FIS, geoid,GRACE, gravity fiel

Deformation analysis with Total Least Squares

Deformation analysis is one of the main research fields in geodesy. Deformation analysis process comprises measurement and analysis phases. Measurements can be collected using several techniques. The output of the evaluation of the measurements is mainly point positions. In the deformation analysis phase, the coordinate changes in the point positions are investigated. Several models or approaches can be employed for the analysis. One approach is based on a Helmert or similarity coordinate transformation where the displacements and the respective covariance matrix are transformed into a unique datum. Traditionally a Least Squares (LS) technique is used for the transformation procedure. Another approach that could be introduced as an alternative methodology is the Total Least Squares (TLS) that is considerably a new approach in geodetic applications. In this study, in order to determine point displacements, 3-D coordinate transformations based on the Helmert transformation model were carried out individually by the Least Squares (LS) and the Total Least Squares (TLS), respectively. The data used in this study was collected by GPS technique in a landslide area located nearby Istanbul. The results obtained from these two approaches have been compared

The depletion of NO in pre-protostellar cores

Understanding the depletion of heavy elements is a fundamental step towards determining the structure of pre-protostellar cores just prior to collapse. We study the dependence of the NO abundance on position in the pre-protostellar cores L1544 and L183. We observed the 150 GHz and 250~GHz transitions of NO and the 93 GHz transitions of \NTHP \ towards L1544 and L183 using the IRAM 30 m telescope. We compare the variation of the NO column density with position in these objects with the H column density derived from dust emission measurements. We find that NO behaves differently from \NTHP \ and appears to be partially depleted in the high density core of L1544. Other oxygen-containing compounds are also likely to be partially depleted in dense-core nuclei. The principal conclusions are that: the prestellar core L1544 is likely to be 'carbon-rich'; the nitrogen chemistry did not reach equilibrium prior to gravitational collapse, and nitrogen is initially (at densities of the order of $10^4$~cm$^{-3}$) mainly in atomic form; the grain sticking probabilities of atomic C, N and, probably, O are significantly smaller than unity

A Lipoxygenase Sensor for Essential Fatty Acid (EFA) Determination

The essential fatty acids (EFAs) are a group of 12 compounds, but linoleic acid and a-linolenic acid are the only EFAs which are found in the diet, particularly in vegetable oils, in some abundance. The other on EFAs are either metabolic products of linoleic and a-linolenic acids or are found in the diet especially in marine foods, considerebly smaller amounts. The steadily growing knowledge about the correlation between the fatty acid composition of the diet and clinical disorders leads to a growing demand for a rapid and easy to use analytical device for fatty acid determination in foods. Up to date, the fatty acid composition of fats and oils is determined mainly by gas chromatography (GC), although GC is well established in lipid analysis and offers high sensitivities, it is still time consuming and laborious . In this study, we describe the development of enzyme sensors for the determination of w-3 and w-6 fatty acis from the mixture of EFAs. Since linoleic and a-linolenic acids show differences in first and second oxygenation activities, it is possible to analyse each of them in EFAs mixture. Lipoxygenases in general catalyse the oxygenation of polyunsaturated fatty acids containing a cis, cis-1,4-pentadiene system by molecular oxygen. The oxygen consumption due to the lipoxygenase catalysed oxygenation of EFAs monitored amperometrically. Lipoxygenase was immobilized on the surface of oxygen electrode by using different membrane systems. Each systems were compared with regard to linear ranges of the calibration plots, sensitivities, detection limits. Furthermore, optimization of working conditions (pH, temperature etc.) and stability tests were also studied