Bulunan: 128 Adet 0.001 sn
Koleksiyon [4]
Tam Metin [1]
Yazar [20]
Yayın Türü [6]
Konu Başlıkları [20]
Yayın Tarihi [16]
Dergi Adı [20]
Yayıncı [1]
Dil [1]
Yazar Departmanı [1]
Subcritical water extraction of phenolic and antioxidant constituents from pistachio (Pistacia vera L.) hulls

Erşan, S. | Güçlü Üstündağ, Ö. | Carle, R. | Schweiggert, R.M.

Article | 2018 | Food Chemistry253 , pp.46 - 54

Pistachio hulls, important by-products of pistachio processing, were extracted using an environmentally friendly process with subcritical water (SCW) at a pressure of 6.9 MPa in the range of 110 and 190 °C, and a flow rate of 4 ml/min. Detailed HPLC-DAD-ESI/MSn analyses allowed the identification of 49 phenolic compounds in the SCW extracts. Total gallotannin yields up to 33 g/kg were reached at 150–170 °C, where gallic acid (22.2 g/kg) and penta-O-galloyl-ß-D-glucose (9.77 g/kg) levels were 13.2- and 10.6-fold higher than those in the aqueous methanol extracts. Flavonols were also effectively extracted at 110–150 °C (4.37–5.65 g/kg . . .), while anacardic acid recovery was poor (1.13–2.77 g/kg). Accordingly, high amounts of anacardic acids (up to 50.7 g/kg) were retained in the extraction residue, revealing that SCW extraction allowed selective extraction of gallotannins and flavonols. Antioxidant capacities ranged from 0.68 to 1.20 mmol Trolox equivalents (TE)/g for SCW extracts increasing with temperature up 190 °C. © 2018 Elsevier Lt Daha fazlası Daha az

Information technology in Turkey: Creating high-skill jobs along with more unemployed highly-educated workers?

Dube, S. | Dube, M. | Turan, A.

Article | 2015 | Telecommunications Policy39 ( 10 ) , pp.811 - 829

We measure the impact of the growth in ICT sector in Turkey on unemployment rates using domestic IT production and total ICT market-size based variables as proxies, from 1990 to 2013, and the sub-period 2000-2013 of rapid ICT growth. Results show that changes in youth and female unemployment rates are correlated positively with growth of domestic IT production. Within educational subcategories, the correlation is positive and significant especially for youth females at lower educational levels; and negative at the vocational high school level, especially for youth male. At the same time the growth in number of individuals employed a . . .s well as workforce size are correlated positively with growth in domestic IT production for male youth at the university level, and negatively at the vocational high school level for females. The youth workforce composition changes significantly during the period of our study. Data suggests that growth in domestic IT production is correlated with more youth undertaking university education and that although additional jobs are created, especially for males, the number of unemployed youth with university degrees also increases. We examine these results in the context of Turkish educational policy changes and discuss the need for coordinating these with policies promoting ICT. © 2015 Elsevier Ltd Daha fazlası Daha az

Proximal femoral nail shows better concordance of gait analysis between operated and uninjured limbs compared to hemiarthroplasty in intertrochanteric femoral fractures

Güven, M. | Kocadal, O. | Akman, B. | Poyanli, O.S. | Kemah, B. | Atay, E.F.

Article | 2016 | Injury47 ( 6 ) , pp.1325 - 1331

Purpose The purpose of this study was to compare the results of pedobarographic gait analysis between the patients treated by proximal femoral nail or bipolar partial hemiarthroplasty due to intertrochanteric fractures. Methods Thirty-seven patients with a minimum 1-year follow-up who had been operated for intertrochanteric fractures were evaluated clinically, radiologically and with pedobarographic gait analysis. Proximal femoral nail had been performed to 21 patients (group A), whilst 16 patients had been operated by partial bipolar hemiarthroplasty (group B). Pedobarographic analysis was performed by measuring plantar pressure, f . . .orce and contact area values in both static and dynamic manner. Pedobarographic results of operated limb were compared among groups. Same data's also were compared between operated and uninjured limbs in each group to determine any asymmetry on weight-bearing. Results Average follow-up period in group A and group B was 36 (12-56) and 30 (12-48) months, respectively. There were no statistically significant differences among groups in terms of age, gender, body mass index, type and side of fracture, follow-up period, leg length discrepancy and postoperative hip scores. When the pedobarographic results of operated limb were compared, group B showed much more plantar force and pressure values than group A, on both static and dynamic evaluations. If the evaluation was taken into consideration to comparison of pedobarographic results between operated and uninjured limbs in each group, we found asymmetry in static load bearing, caused by higher load on uninjured limb in both groups. However, there was no statistically significant asymmetry between operated and uninjured limbs in respect to dynamic pedobarographic parameters for patients in group A. On the contrary, operated limbs in group B exposed much more plantar force and pressure values than uninjured limbs, which indicated asymmetric weight-bearing on dynamic evaluation. Conclusions Assessment of pedobarographic parameters can be another way of measuring the results of treatment in intertrochanteric fractures. Uninjured limbs of patients expose much more loading than operated limbs in postoperative static evaluation for both treatment options. However in dynamic evaluation, there is a better concordance of gait analysis between both limbs in patients operated by proximal femoral nail. © 2016 Elsevier Ltd. All rights reserved Daha fazlası Daha az

Solving a robust airline crew pairing problem with column generation

Muter, I. | Ilker Birbil, Ş. | Bülbül, K. | Şahin, G. | Yenigün, H. | Taş, D. | Tüzün, D.

Article | 2013 | Computers and Operations Research40 ( 3 ) , pp.815 - 830

In this study, we solve a robust version of the airline crew pairing problem. Our concept of robustness was partially shaped during our discussions with small local airlines in Turkey which may have to add a set of extra flights into their schedule at short notice during operation. Thus, robustness in this case is related to the ability of accommodating these extra flights at the time of operation by disrupting the original plans as minimally as possible. We focus on the crew pairing aspect of robustness and prescribe that the planned crew pairings incorporate a number of predefined recovery solutions for each potential extra flight . . .. These solutions are implemented only if necessary for recovery purposes and involve either inserting an extra flight into an existing pairing or partially swapping the flights in two existing pairings in order to cover an extra flight. The resulting mathematical programming model follows the conventional set covering formulation of the airline crew pairing problem typically solved by column generation with an additional complication. The model includes constraints that depend on the columns due to the robustness consideration and grows not only column-wise but also row-wise as new columns are generated. To solve this difficult model, we propose a row and column generation approach. This approach requires a set of modifications to the multi-label shortest path problem for pricing out new columns (pairings) and various mechanisms to handle the simultaneous increase in the number of rows and columns in the restricted master problem during column generation. We conduct computational experiments on a set of real instances compiled from local airlines in Turkey. © 2010 Elsevier Ltd Daha fazlası Daha az

The effect of 1,25 dihydroxyvitamin D3 on HCl/Ethanol-induced gastric injury in rats

Sahin, H.H. | Cumbul, A. | Uslu, U. | Yilmaz, Z. | Ercan, F. | Alican, I.

Article | 2018 | Tissue and Cell51 , pp.68 - 76

This study evaluated ulceroprotective and antioxidant effect of 1,25 dihydroxyvitamin D3 against gastric damage in rats. Rats were treated intraperitoneally with either 1,25 dihydroxyvitamin D3 (0.25 µg/kg) or saline for 14 days. On day-15, the non-selective cyclooxygenase inhibitor indomethacin (10 mg/kg; subcutaneously), the inhibitor of sulfhydryl groups N-ethylmaleimide (10 mg/kg; intraperitoneally) or ATP-sensitive K+ channel blocker glibenclamide (10 mg/kg; orally) was given prior to 1,25 dihydroxyvitamin D3. Animals were euthanized at 60 min post ulcerogenic challenge (0.3 M HCl and 60% ethanol (0.2 mL; orally). Stomach and b . . .lood were collected for biochemical and histological evaluations. HCl/Ethanol group revealed severely damaged mucous and glandular epithelium with diffuse hemorrhage and inflammatory cell infiltration (microscopic score: 10.67 ± 0.67 and ulcer index: 33.13 ± 5.09). 1,25 dihydroxyvitamin D3 decreased the extent of damage (microscopic score: 6.80 ± 0.02 and ulcer index: 19.00 ± 4.34; p < 0.05), and the elevations in gastric malondialdehyde level (p < 0.001), myeloperoxidase activity (p < 0.001), nuclear factor-?B expression (p < 0.05), and apoptotic index (p < 0.05) following HCl/Ethanol challenge. Decreased gastric glutathione following HCl/Ethanol administration was restored by 1,25 dihydroxyvitamin D3 (p < 0.01). These findings demonstrated protection of the gastric mucosa against HCl/Ethanol-induced injury by 1,25 dihydroxyvitamin D3 via attenuation of inflammatory reaction, oxidative stress and apoptosis. © 2018 Elsevier Lt Daha fazlası Daha az

A flexible heuristic for a multi-mode capital constrained project scheduling problem with probabilistic cash inflows

Özdamar, L. | Dündar, H.

Article | 1997 | Computers and Operations Research24 ( 12 ) , pp.1187 - 1200

We consider housing projects where an initial capital covers activity expenditures in the starting phase of the project and then, customers who arrive randomly over the project span provide the necessary funds for continuation. The goal is to maximize financial returns, i.e., the project Net Present Value (NPV). Here, capital is considered as a limited nonrenewable resource which is reduced by activity expenditures and augmented by the sales of flats. Activities may be carried out in different operating modes with different durations. The total cost of an activity is fixed irrespective of its operating mode. Thus, the rate of activi . . .ty expenditures differ from mode to mode. As the previous scheduling decisions are the only controllable factors affecting the available capital at any period, it is important to adjust the speed of expenditures, namely, to select the correct activity modes. The contractor, never sure of the timing of the cash inflows, has to schedule the activities in modes which do not lead to financial bottlenecks and at the same time he has to deliver the project on time. The contractor may also borrow capital from an external source. We propose a flexible heuristic algorithm for solving the capital constrained mode selection problem where there exist general precedence relationships among activities and the magnitude of precedence lags depend on the specific activity mode selected. The algorithm is flexible in the sense that different mode selection criteria are utilized at different decision times depending on the cumulative progress of the project and on some parameters controlled by the contractor. The proposed algorithm may be used as a simulation tool to adjust parameters before the project starts or it may be used as a scheduler during the progress of the project given the current financial situation and cumulative project work done. We test the algorithm by using a typical housing project with real data and also by using hypothetical test problems. The results indicate that the schedules generated are satisfactory with regard to meeting the target project due date and maximizing NPV. © 1997 Elsevier Science Ltd Daha fazlası Daha az

On-site pXRF analysis of glaze composition and colouring agents of “Iznik” tiles at Edirne mosques (15th and 16th-centuries)

Simsek, G. | Unsalan, O. | Bayraktar, K. | Colomban, P.

Article | 2019 | Ceramics International45 ( 1 ) , pp.595 - 605

The production of the tiles in Ottoman Empire had begun as a continued workshop of Seldjuk ceramic art, and after this initial phase, its own technology was introduced into Ottoman art by local craftsmen. Iznik tiles are among the most appreciated pottery masterpieces, and wall decoration in tiles is a significant asset of Unesco World Heritage Edirne mosques. Rare glaze composition studies have been made, which justify the need for more comprehensive studies. We present here the first on-site elemental analyses performed with portable XRF instrument in four of the most representative mosques in Edirne (Şah Melek Paşa (1429), Muradi . . .ye (1435–1436), Üç Şerefeli (1410–1447) and Selimiye (1569–1575)). A handheld 785 nm Raman spectrometer was used as a complementary technique to identify some pigments. About forty tiles have been analysed in this research. Additionally, two tiles from Yeşilce Mosque (1442, Edirne) have been analysed at the Selimiye Foundation Museum. The weight percent of the elements measured with pXRF are normalized by Si amount in order to eliminate the variation due to the positioning shifts. Different glazing technologies are evidenced (Master of Tabriz Sn-free glazed tiles, Hünkar Mahfili Sn-poor glazed tiles, and Sn-(Bi) rich ones). At least three different cobalt ores have been used (with characteristic Cu, Ni, Mn and Bi content) in blue decors. Use of a chromium-based ore is demonstrated for some Selimiye Hünkar Mahfili tiles. The link between Şah Melek Paşa and polychrome (mihrab) Muradiye tiles and Seldjuk production is established. On the contrary, the technology of Üç Şerefeli and blue-and-white Muradiye tiles is unique and appears a precursor of 16th-century Iznik production. Bismuth, Sn/Pb, Co/Mn, and Co/Ni ratio appears very useful to compare the different glazes and to identify mining sources of cobalt. © 2018 Elsevier Ltd and Techna Group S.r.l Daha fazlası Daha az

Modeling 3D melt electrospinning writing by response surface methodology

Dayan, C.B. | Afghah, F. | Okan, B.S. | Yıldız, M. | Menceloglu, Y. | Çulha, Mustafa | Koc, B.

Article | 2018 | Materials and Design148 , pp.87 - 95

Three-dimensional (3D) melt electrospinning writing (MEW) is a promising technique for 3D printing of porous scaffolds with well-defined geometrical features. The diameter of electrospun fibers strongly affect the achievable resolution and consequently several other physical, mechanical, and structural properties of the fabricated scaffold. However, there are a few process parameters which significantly affect the size of electrospun fibers. In this study, response surface methodology (RSM) was used to investigate the critical and optimized process parameters and their interaction effects on the desired fiber diameter. Four process . . .parameters, including collector speed, tip-to-collector distance, applied pressure, and voltage were studied considering their practical ranges. The results showed that all the parameters except the applied voltage had a significant effect on the printed fiber diameters. A generalized model for the interaction effects of the parameters was introduced which can be used as a framework for selecting the process parameters to achieve the desired fiber diameter. The developed model was validated by choosing random process parameters and printing three-dimensional scaffolds. The results confirm that the predicted fiber diameters match closely with the actual fiber diameters measured directly from the printed scaffold. © 2018 Elsevier Lt Daha fazlası Daha az

Thermodynamic efficiency of synthesis, storage and breakdown of the high-energy metabolites by photosynthetic microalgae

Sorgüven, E. | Özilgen, M.

Article | 2013 | Energy58 , pp.679 - 687

Lipids and carbohydrates are employed in the nature to store internal energy due to the large number of the high energy atomic bonds in their structure. Internal energy stored in the bonds is used to fuel work producing engines or metabolic activity of living organisms. This paper investigates the thermodynamic efficiency of the glucose and lipid synthesis and breakdown by photosynthetic microalgae. Photosynthetic microalgae are able to convert 3.8% of the solar exergy into the chemical exergy of algal lipid. As the microalgae convert the first product of the photosynthesis, i.e. glucose, into lipid, 47-49% of the chemical exergy is . . . lost. If the microalgal cell consumes the photosynthetically produced glucose for its own energy demand, then about 30% of the glucose exergy can be converted into work potential in case of immediate and short-term energy demands. Organism can convert about 22% of the glucose exergy into work potential after a long-term storage. If the algal lipid is harvested for biodiesel production and the produced biodiesel is combusted in a Diesel engine, then about 17% of the exergy of the photosynthetically produced glucose can be converted into useful work. Biodiesel is among the most popular renewable fuels. The lipids are harvested from their storage in the cells to produce biodiesel before following the lipid breakdown path of the cellular metabolism. Our analysis indicates that, extracting the first product of photosynthesis, i.e. glucose or glucose polymers instead of lipids may be more efficient thermodynamically, if new motors capable to extract their bond energy is developed. © 2013 Elsevier Ltd Daha fazlası Daha az

The impact of international trade on environmental quality: The case of transition countries

Halicioglu, F. | Ketenci, N.

Article | 2016 | Energy109 , pp.1130 - 1138

This research presents first empirical time series evidence of the impact of international trade on environmental quality in the case of transition countries. The linkages between international trade and environmental quality are well established both theoretically and empirically in the literature. However, there exists no empirical study concerning environmental quality and international trade. Thus, our research aims at filling this gap. To this extent, fifteen transition countries are selected in order to test the impact of international trade on environmental quality. An econometric model between carbon emissions, energy use, i . . .ncome and trade openness was formed. This model was estimated via ARDL (Autoregressive Distributed Lag) approach to cointegration and GMM (Generalized Method of Moments) procedures. The econometric results from both of these econometric techniques support the existence of the EKC hypothesis only in three transition countries: Estonia, Turkmenistan and Uzbekistan. As for the impact of trade on environmental quality, the econometric results from both techniques vary in different transition countries. To this extent, the displacement hypothesis is validated in the case of Armenia, Estonia, Latvia, Kyrgyzstan and Russia. The paper also discusses policy implications of the empirical results, as well as offering policy recommendations. © 2016 Elsevier Ltd Daha fazlası Daha az

Energy utilization and carbon dioxide emission in the fresh, paste, whole-peeled, diced, and juiced tomato production processes

Karakaya, A. | Özilgen, M.

Article | 2011 | Energy36 ( 8 ) , pp.5101 - 5110

Energy utilization and carbon dioxide emission during the production of fresh, peeled, diced, and juiced tomatoes are calculated. The energy utilization for production of raw and packaging materials, transportation, and waste management are also considered. The energy utilization to produce one-ton retail packaged fresh tomatoes is calculated to be 2412.8 MJ, whereas when the tomatoes are converted into paste, the energy utilization increases almost twofold; processing the same amount into the peeled or diced-tomatoes increases the energy utilization seven times. In case of juice production, the increase is five times. The carbon di . . .oxide emission is determined by the source of energy used and is 189.4 kg/t of fresh tomatoes in the case of retail packaging, and did not change considerably when made into paste. The carbon dioxide emission increased twofold with peeled or diced-tomatoes, and increased threefold when juiced. Chemical fertilizers and transportation made the highest contribution to energy utilization and CO2 emission. The difference in energy utilization is determined mainly by water to dry solids ratio of the food and increases with the water content of the final product. Environmentally conscious consumers may prefer eating fresh tomatoes or alternatively tomato paste, to minimize carbon dioxide emission. © 2011 Daha fazlası Daha az

Determining type 2 diabetes risk factors for the adults: A community based study from Turkey

Cosansu, G. | Celik, S. | Özcan, S. | Olgun, N. | Yıldırım, N. | Gulyuz Demir, H.

Article | 2018 | Primary Care Diabetes12 ( 5 ) , pp.409 - 415

Aims: This study aimed to determine risk factors for type 2 diabetes among adults who were not diagnosed with diabetes. Methods: Adults were included in this study within the public activities performed on World Diabetes Day (n = 1872). Data were collected using the FINDRISC questionnaire and a short questionnaire. Results: Participants’ mean age was 39.35 ± 10.40. The mean FINDRISC score was 7.46 ± 4.62, women's mean score was higher than that for men. The FINDRISC score indicates that 7.4% of the participants were in the highrisk group. Among participants, BMI value of 65.1% was 25 kg/m 2 and higher, waist circumference of 58% was . . . over the threshold value; and 50.7% did not engage in sufficient physical activity. Of the participants, 9.5% had a history of high blood glucose, families of 38.9% had a history of diabetes. The mean FINDRISC score was in the slightly high category, 121 participants were found likely to be diagnosed with diabetes within ten years if no action was taken. Conclusions: It is recommended the risk screening studies to be conducted and the FINDRISC tool to be used in Turkey, where diabetes prevalence is increasing rapidly, to determine diabetes risks in the early period and to raise social awareness for diabetes. © 2018 Primary Care Diabetes Europ Daha fazlası Daha az

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