Hakan Akca

Photovoltaic (PV) systems are considered as a support unit and eco-friendly energy source for the electric vehicles. If the surface of the electric vehicle is covered by PV cells, it is possible to store considerable amount of energy in the battery system. In this study, different maximum power point trackers (MPPT) with different maximum power point (MPP) tracking algorithms have been tested on a PV structure moving according to a predefined motion loop. Compatibility of each algorithm to moving systems, such as electric vehicles, is presented in a real experimental environment. As a result of these experiments, positive factors in each algorithm have been defined and a new MPP tracking algorithm convenient for moving vehicle has been proposed. The proposed MPPT algorithm shows a better performance than other MPPT algorithms under fast varying radiations. However, proposed algorithm brings slightly higher costs compared to usage of other MPPT algorithms since it requires the measurement of solar irradiance. The developed algorithm is described in detail and comparative analysis and performance evaluation with other algorithms are presented.

The aim of ethnobotany is to study how and why people use and conceptualize plants in their local environments. The most asked two questions are: how and in what ways people use nature, and how and in what ways people view nature. Ethnobotanists gather data mainly from living peoples in hopes of gathering a view of their past existence as well as an understanding of present uses of plants for food, medicine, construction materials, and tools. More than 500 geophyte species grow naturally in Turkey and the bulbs of the majority of these are exported.The genus Cyclamen L. (Myrsinaceae) comprises about 21 species, which are predominately distributed in the Mediterranean area especially Greece and Turkey. In Turkey, this genus is represented with 10 species, 4 of which are endemic.The species of this genus grow naturally in dry forest or scrub where they are at least partly shaded from intense sunlight. The flowers are white, pink, purple or carmine with scented or unscented flowers and...

Recently, alternative energy based vehicles have drawn the attention of engineers specifically on the production of fully electric powered vehicles due to increased environmental awareness and fuel cost. As a result of difficulties in commercializing the vehicles, electric powered cars find an application area in public transportation. One of the solutions for public transportation is to use trolleybus system. This paper gives a comparison of Trolleybus system and existing Metrobus system in Istanbul, Turkey in terms of energy costs and CO2 emissions. The simulation results show that using Trolleybus system instead of Metrobus is much more economical based on the current prices. As for the emissions, the amount of CO2 for city centers and overall environment is evaluated.

Mutations in the EGFR gene are critical determinants of treatment with EGFR tyrosine kinase inhibitors (TKIs) for non-small cell lung cancer (NSCLC) patients. DNA isolation from tumor samples usually requires surgery; therefore, we wanted to isolate DNA from circulating tumor cells by using the serum of NSCLC patients. This protocol was recently published. DNA was isolated from the serum of 52 Turkish NSCLC patients and their EGFR mutation status was examined by pyrosequencing. EGFR mutations were detected in 25 of the 52 patients (48.1%): 17 patients with delE746-A750, 2 with delE747-A750insP, and 6 with L858R. All mutations detected by pyrosequencing were confirmed by dideoxy sequencing, and the presence of the same mutations in the tumors was verified by using paraffin embedded tissues of all the patients. Mutations were detected more frequently in adenocarcinomas (24 of 36, 66.7%) than in squamous cell carcinomas (1 of 16, 6.3%) (P<0.001). These results confirm the utility of serum DNA and pyrosequencing for the detection of EGFR mutations in patients with advanced NSCLC.

kserdar1@yahoo.com Abstract Epilobium hirsutum L. (E.H) known as its high number of phenolic and flavonoid contents is distributed in worldwide. As a medicinal herb it has been used as an anticoagulant, anti-inflammatory and rectal and menstrual bleeding preventer. CYP2B1, CYP2C6, CYP2D6 and CYP3A1 are the important isoforms of cytochrome P450 enzymes with their private role on drug metabolism. Identification of phenolic compounds of E.H was done by using liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS). 18.75 mg extract/kg body weight/day was intraperitoneally (i.p.) injected to rats for 9 days to investigate in vivo effects of E.H on liver drug metabolizing CYP2B1, CYP2C6, CYP2D2 AND CYP3A1 mRNA and protein expressions as well as enzyme activities. Cytotoxic effect of E.H was tested by measuring lactate dehydrogenase activity. Although E.H. treatment caused 53 % inhibition of the benzphetamine N-demethylase (CYP2B1) and erythromycin N-demethylase (CYP3A1) enzyme ...

There are many equipment such as transformers, high voltage cables, insulators, breakers, etc., work in power systems under high voltages. The insulation oils are used in such systems to provide the insulation and cooling respectively for high voltages and temperature rises in conductors. These kinds of oils should be qualified in terms of insulation and should have some certain features for power system stability. Therefore, suitability of the physical, chemical and electrical properties of the insulation oils is specified with standard tests. These tests are performed according to the IEC 60156, ASTM D1816 and ASTM D877 .In this study, breakdown voltage variation of insulation oil which is used for high voltage equipment is investigated for particular working conditions. In experimental study, there are two types of insulation oils which are non-aged and aged insulating oils. Breakdown voltages of these insulation oils are measured for different voltage rising speed mentioned in t...

The tumor suppressor protein p53 is the most frequently mutated gene in human cancer. The function of p53 is not restricted to "guarding" against oncogenic stress, but also p53 can guard against the presence of DNA damage. One of the principal mechanisms by which cells achieve this is by regulating the p53 protein level although its phosphorylation and cellular localization also contribute to the regulation of its function. Since many tumors secrete growth factor(s) that inhibit apoptosis and support the growth of cancer cells, we investigated the effects of human epidermal growth factor (EGF) on human TNF-alpha-mediated induction of p53 and its transcriptional target, p21 in TNF-alpha sensitive human cervical carcinoma cell line, ME180S. We found that TNF-alpha can increase the cellular levels of p53, p21 and induce apoptosis in ME180S cells. However, pretreatment of cells with EGF can suppress all these effects of TNF-alpha. To determine which kinase(s) pathway was utili...

The tumor suppressor protein p53 plays an important role in the protection against the development of cancer and is inactivated in many human malignancies. Since p53 is an important inhibitor of cell growth, keeping p53 function under control is critical for survival of cell. One of the principal mechanisms by which cells achieve this is by regulating the p53 protein level, although its phosphorylation and cellular localization also contribute to the regulation of its function. Since many tumors secrete growth factor(s) that inhibit apoptosis and support the growth of cancer cells, we wanted to know whether insulin would have an effect on antitumor and p53-inducing activities of human tumor necrosis factor-alpha (TNF-alpha). Here we show that treatment of human cervical carcinoma cell line, ME-180S, with TNF-alpha results in time-dependent accumulation of p53 and its transcriptional target, p21. However, pretreatment of these cells with insulin inhibits TNF-alpha-dependent cell killing, induction of p53, p21 and apoptosis.