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Search Results: 1 - 10 of 463 matches for " Hilal ACAR "
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The effect of stopping power ratios of different protocols on %DD curve
Hilal ACAR
Turkish Journal of Oncology , 2009,
Abstract: OBJECTIVES: The effects of the stopping power ratios of different protocols on %DD curve were investigated in this study. METHODS: Percentage ionization curve was measured at SSD=95 cm using 10x10 standard cone and 6, 8, 10, 12, 15 and 18 MeV electron energies. Stopping power ratios at each depth were determined as recommended by the three protocols. %DD curves were then found and compared. The stopping power ratios of the different protocols were determined and plotted against R50. RESULTS: The stopping power ratios of the different protocols did have an effect on %DD curves. The clearest difference was seen at the surface. The maximum difference was 1.45% at 10 MeV, while the minimum difference was 0.09% at 6 MeV. CONCLUSION: Stopping power ratios as found using realistic electron beams provide more accurate surface doses, as reported in the literature.
Comparison of IAEA absorbe dose protocols TRS 277, TRS 381 and TRS 398 for different electron energies
Hilal ACAR
Turkish Journal of Oncology , 2007,
Abstract: OBJECTIVES: In this study, calculation of absorbed doses according to three different IAEA protocols for 6, 8, 10, 12, 15, and 18 MeV electron energies were compared. METHODS: Absorbe dose measurements were made at SSD=95 cm distance, 10 x 10 cm standart cone and reference depth. Electron energies was measured with five different cylindirical chambers and three different paralel plate chambers. Polarity and recombination effects were measured for all ionization chambers and energies before absorbed dose measurements. RESULTS: After the measurements, calculations were made according to three different protocols. For Marcus parallel plate chambers, the ratio of absorbe dose protocols was between -2.04% to 2.64%. Except from Marcus for other parallel plate chamber difference was between 0.11% to 3.38% for 6 MeV, 0.33% to 1.37% for 8 MeV, 0.12% to 1.71% for 10 MeV, 1.35% to 0.23% for 12 MeV, 1.69% to 0.24% for 15 MeV and 0.22% to 1.74% for 18 MeV. CONCLUSION: Contrary to photon energies, difference between absorbe dose protocols for electron beam energies was high. The reason of the difference was arise from the fact that TRS 277 assumes perturbation factor of parallel plate chambers was “1”. As a result, TRS 398 protocol enables us to calculate much more accurate absorbe dose.
Energy and field size dependence of polarity
Hilal ACAR
Turkish Journal of Oncology , 2010,
Abstract: OBJECTIVES: The aim of this study was to investigate polarity effects of electron beams with different energies. METHODS: Energy dependence of polarity error was investigated at dmax and SSD=95 for 6, 8, 10, 12, 15 and 18 MeV electron beams from Phillips SL-25 LINAC. Field size dependence of polarity effect was investigated at dmax and SSD=95 cm using 6x6, 10x10, 14x14 and 20x20 cm2 standard electron cones for 6, 8, 10, 12, 15 and 18 MeV electron beams from Phillips SL-25 LINAC. RESULTS: Polarity effect decreased as electron beam energy increased. While polarity error was 0.52% for high energies, it increased up to 4.5% for low energies. Moreover, polarity error increased as field size increased for the same electron energy. CONCLUSION: In conclusion, especially for low energies and wide field sizes, polarity error is measured and used in absolute dose calculations for parallel plate chambers.
Comparison of theoretical and experimental values of TRS 398 absorbed dose to water
Hilal ACAR
Turkish Journal of Oncology , 2008,
Abstract: OBJECTIVES: In this study, experimentally and theoretically determined absorbed dose to water calibration factors were compared. We used 6 MV photon and 12 MeV electron energies to compare experimentally and theoretically determined beam quality dependence factors. METHODS:Measurements were made at SSD=100 cm distance (LINAC), 10x10 cm standard field size and reference depth. Five different cylindrical and three parallel plate chambers were used. RESULTS: For absorbed dose to water calibration factor, the max difference between theoretical and experimental values was 2.8% for Marcus chamber. Beam quality dependence factors for 6 MV theoretical values of PTW 30001 (a) (-0.816%), NE 2571 (-0.1107%) were greater than their experimental values. For 12 MeV, the difference was 1.2371% for PTW 30001 (a), 1.6774% for PTW 30001 (b), 0.8758% for NE 2571, 0.8363% for NE 2581, 0.6071% for PTW 30002, and 0.6245% for Marcus ion chamber. CONCLUSION: As the protocol suggests, obtaining absorbed dose to water calibration factor directly from SSDL produces more accurate results.
Verification of plaque simulator dose distributions using GAFCHROMIC EBT film
Hilal ACAR
Turkish Journal of Oncology , 2010,
Abstract: OBJECTIVES: Off-axis dose profile and central-axis dose distributions were measured using GAFCHROMIC EBT film and calculated using BEBIG plaque simulator for COMS plaques of 14, 16, 18 and 20 mm diameter fully loaded with I-125 seeds. Results were compared to verify dose distribution as calculated by BEBIG. METHODS: Measurements were made on polystyrene eye phantom placed in a wax head phantom. RESULTS: The results of GAFCHROMIC EBT film were 13% lower than the results using BEBIG plaque simulator. This can be attributed to the facts that the model eye does not reflect the human eye exactly and that our measurement devices are inadequate. CONCLUSION: The BEBIG treatment planning computer can be used considering the shortcomings with respect to the first few mm and remote off-axis points. Furthermore, dose verification in patients can be made using GAFCHROMIC EBT film on a model eye phantom.
Comparison of IAEA absorbed dose protocols TRS 277 and TRS 398 for different photon energies
Turkish Journal of Oncology , 2006,
Abstract: OBJECTIVES: In this study, calculation of absorbed doses according to three different IAEA protocols for Co-60, 6 MV, 25 MV photon energies are compared. METHODS: Absorbed dose measurements are made at SSD=SAD distance, 10x10 cm field size and referance depth. Photon energies are measured with five different cylindirical chambers. Polarity and recombination effects are measured for all ionization chambers and energies. RESULTS: After the measurements, calculations are made according to two different protocols and absorbe dose calculated according to TRS 398 protocol is maximum 0.32% bigger than TRS 277’s dose for Co-60, and 0.57% bigger for 6 MV and 1.53% bigger for 25 MV. CONCLUSION: As a result, TRS 398 protocol enables us to calculate much more accurate absorbe dose.
The association of anthropometric measurements and lipid profiles in Turkish hypertensive adults
Yildiran Hilal, TN Acar, E Koksal, KM Gezmen, G Akbulut, S Bilici, N Sanlier
African Health Sciences , 2011,
Abstract: Background: Few studies have associated anthropometric measurements and lipid profile with hypertension in adult populations and to the best of our knowledge none has been done in Turkey Objectives: To relate anthropometric derivatives of overweight/obesity with hyperlipidemia status in a group of Turkish hypertensive adults. Methods: Six hundred forty nine (307 male, 342 female) hypertensive adults aged between 20 and 64 yearswere included in the study. Results: The mean systolic and diastolic blood pressure (BP) of participants were measured as 147.6±17.2 and 91.4±10.4 mmHg for males and 149.9±16.3 and 91.1±9.4 mmHg for females, respectively. With respect to BMI classification systolic BP was significantly higher in obese males and females, and diastolic BP was only higher in obese females (p<0.05). According to BMIs for lipid profile, high-density lipoprotein-cholesterol (HDL-C), total cholesterol (TC) levels were found to be lower in normal females than other BMI groups. Age and waist circumference (WC) in particular was the most related factor for systolic and diastolic BP in both genders (p<0.05). Conclusions: This study indicates most hypertensive adults surveyed were overweight and obese. Furthermore, age and WC were the important factors that affects the systolic and diastolic BP in both genders.
Hospital community benefits and the effect of Schedule H: A difference-in-difference approach  [PDF]
Helen Schneider, Hilal Yilmaz
Health (Health) , 2013, DOI: 10.4236/health.2013.510226

Since 1969 private, nonprofit hospitals have qualified for tax exemption as charitable institutions and in exchange for the preferential tax treatment were required to provide community benefits. However, in the absence of mandatory reporting of community benefits at the federal level and in the absence of a clear definition of community benefits, the previous literature provides but ambiguous evidence regarding hospitals’ supply of community benefits. Responding to policymakers’ concerns, the Internal Revenue Service (IRS) mandates all private, non-profit hospitals to report charity care at cost as well as unreimbursed Medicaid costs starting with the tax year 2008. Using data from hospitals in California before and after tax year 2008 (2009 filing), this study examines whether changes in the IRS 990 Schedule H had a significant effect on the supply of community benefits by non-profit hospitals relative to for-profit hospitals. Empirical results suggest that nonprofit hospitals do not supply more community benefits relative to for-profit hospitals for both definitions of community benefits reported in Schedule H. Although the supply of community benefits increased for all hospitals after 2008, the increase was not higher for nonprofits. Moreover, nonprofits supplied significantly less community benefits according to some definitions. Thus, minimum charity care standard is justified.

Hilal Turgut
Tarih Kültür ve Sanat Ara?t?rmalar? Dergisi , 2012,
Abstract: zetH zla de i en ve kal c olmayan bah e tasar mlar g ebe hayattan yerle ik hayata ge en Türk toplumunun de i im süreci i in nemli ipu lar verebilirdi. Ancak de erlendirme yap labilecek bah e rnekleri ok az bulunmakta ve olanlar n da de i ime u ray p u ramad klar net olarak bilinmemektedir. Bu al mada; farkl sanat ak mlar ile tan m olan, o unun varl n ancak kitaplardan bildi imiz tarihi Türk Bah elerinin havuz detaylar n n incelenerek Türk bah e kültürü hakk nda bilgi edinilmesi ama lanm t r. al mada, a rl kl olarak son tan k olan Sedad Hakk Eldem’in kaynaklar Türk dünyas n n nemli sanat kollar ndan olan tarihi belge niteli i ta yan minyatürler, gezgin notlar , e itli rehber nitelikli kaynaklar incelenmi tir. al mada minyatürlerin tercih edilme sebebi, minyatürlerin ince ayr nt lar n g sterildi i resimler olmas n n yan s ra Türk resminden nce minyatür sanat rneklerinin var olmas ve ar iv niteli inde al malar olarak de erlendirilebilmesidir. Minyatürde g rünümden ok fikir ve ger eklik n plandad r. al man n sonucunda bundan sonra yap lacak Türk Bah esi al malar i in daha detayl bir bak a s ortaya konulmas umut edilmektedir. The fast changes and non-permanent designs in Historical Turkish gardening could have given us important hints about the process of how nomadic Turkish people transformed into the settled life. But there are few samples of these designs to know if they underwent any changes. This study aims at giving information about the pool structures in the historical Turkish gardens, which are closely related to the Turkish culture. In doing so, the study examines the works of Sedad Hakki Eldem, together with miniatures, travel notes and various guiding notes. The reason why miniatures are chosen is because they are not only the pictures which give details but they were also existing in Turkish culture before the painting was used, so that miniatures could be evaluated as archives. In miniatures, idea and realism are more important rather than the look. As a result of this work, we expect to have a more detailed understanding of Turkish gardens for future use.RésuméLes dessins des jardins en pleine mutation peuvent donner des indices importants relatifs au processus de changement de la société Turque qui passe de la vie nomade à la vie urbaine. Cependant, il y a très peu d’exemples de jardin pour pouvoir évaluer ces changements, nous ne savons d’ ailleurs pas si ces transformations/changements ont eu lieu. Dans cette étude, nous avons voulu obtenir des renseignements au sujet de la culture du jardin
Evaluation of cadmium, lead, copper, iron and zinc in Turkish dietary vegetable oils and olives using electrothermal and flame atomic absorption spectrometry
Acar, Orhan
Grasas y Aceites , 2012, DOI: 10.3989/gya.047512
Abstract: The Cd, Pb, Cu, Fe and Zn contents of some edible vegetable oils (soybean, sunflower, flower, nut, corn and olive) and of olives (olive-1, black, green, black crushed with seeds and green crushed with seeds) were determined and evaluated by an electrothermal atomic absorption spectrometer (ETAAS) using an Sc + Ir + NH4H2PO4 chemical modifier mixture and flame atomic absorption spectrometer (FAAS) after microwave digestion. The pyrolysis and atomization temperatures of Cd, Pb and Cu in sample solutions with and without the modifier mixture were investigated. The limits of detection (LOD) for analytes found are 0.1, 0.6, 0.9, 15.0 and 12.0 μg L–1 for Cd, Cu, Pb, Fe and Zn, respectively. The accuracy of the procedure proposed was confirmed by analyzing bovine liver 1577b standard reference material (SRM) and a spiked sample solution. The results of the analytes found were compared with certified and added values. The relative standard deviations of the analytes found were lower than 7% and the percent of recoveries obtained ranges from 96 to 101%. The Sc + Ir + NH4H2PO4 mixture proposed was applied for the determination of Cd, Pb and Cu in oils and olives. The results of analytes found in the samples were compared with international and national food quality guidelines as well as with literature values. Se han determinado los metales Cd, Cu, Pb, Fe y Zn en aceites vegetales comestibles (soja, girasol, flores, nueces, maíz y aceite de oliva) y aceitunas (aceitunas-1, negra, verde, negra machacadas con semillas y verde machacadas con semillas) mediante espectrometría de absorción atómica electrotérmica (ETAAS) utilizando como modificador químico la mezcla Sc + Ir + NH4H2PO4 y mediante espectrometría de absorción atómica de llama (FAAS) tras digestión con microondas. Se estudiaron las temperaturas de pirólisis y atomización para Cd, Pb y Cu en disolución con y sin modificador. Los límites de detección (LOD) fueron: 0.1, 0.6, 0.9, 15.0 y 12.0 mg L–1 para Cd, Cu, Pb, Fe y Zn, respectivamente. La precisión del procedimiento propuesto se confirmó mediante el análisis de materiales estándar de referencia (SRM) 1577b de hígado de bovino y mediante una solución de muestra sembrada. Los resultados se compararon con los valores certificados. Las desviaciones estándar fueron inferiores al 7% y el rango de las recuperaciones obtenidas de 96 a 101%. La mezcla propuesta Sc + Ir + NH4H2PO4 se aplica a la determinación de Cd, Pb y Cu en los aceites y en aceitunas. Los resultados encontrados en las muestras se compararon con los recogidos en las reglamentaciones internaciona
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