48 research outputs found

    Analysis of a nanofilm of the mercaptophenyl diazonium modified gold electrode within new statistical parameters

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    The main aim of this study is to characterize the nanosurface of the mercaptophenyl diazonium modified gold (Au) surface by a new statistical approach. In this study the gold electrode surfaces were self-assembled in ethyl alcohol by 1.0 mM mercaptophenyl diazonium. FT-IR spectra of the surface modifier molecules in both solid and nanofilm of mercaptophenyl diazonium (MCP-Au) forms were recorded in the spectral range of 600-4,000 cm-1. The FT-IR spectra of solid mercaptophenyl diazonium tetrafluoroborate salt were obtained by using KBr pellets. The above FT-IR spectra of both bare Au and its nanofilm of mercaptophenyl diazonium were processed by new statistical approach to reach optimal smoothing trend for the characterization of the modified electrode surface consisting of the nanofilm of gold-mercaptophenyl diazonium. In the frame of new statistical approach all measured spectra have been 'read' in terms of a set of universal statistical parameters. These new parameters help to establish the statistical proximity of the smoothed spectra compared and give a possibility to classify the measured spectra in accordance with new set of statistical and robust quantitative values. Besides, there is a possibility to receive the relative fluctuations and the smoothed spectra of the second order. So, thanks to new approach we do not loose any measured information: the smoothed spectra and accompanied them noise (relative fluctuations) can be analyzed separately for detection of possible influence of predominant external factors that can be essential for this type of measurements. Copyright © 2010 American Scientific Publishers All rights reserved

    Analysis of the effect of potential cycles on the reflective infrared signals of nitro groups in nanofilms: Application of the fractional moments statistics

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    The effect of the potential cycles on the reflective IR signals of nitro-groups in nanofilms was studied for the statistical characterization of nitrobenzene (NB) and nitroazobenzene (NAB)-modified glassy carbon (GC) surfaces. Both NB and NAB nanofilms were obtained by the electrochemical reduction of the diazonium tetrafluoroborate salts in acetonitrile using cyclic voltammetry (CV). The modified surfaces were denoted as GC-(NB)n and GC-(NAB)n, respectively, where n indicates the number of CV cycles performed during modification. Reflective IR signals of the normalized NB and NAB nanofilms and GC were used for the quantitative evaluation of the effect of the potential cycles on the reflective IR signals of nitro-groups in nanofilms. The detection and quantitative reading of the influence of number of CV cycles were realized in the frame of a new error controllable approach that was applied for analysis of all available set of data. This approach includes in itself the following basic steps: (a) the procedure of the division (normalization) on the GC spectra, (b) the comparison of the smoothed spectra for their statistical proximity in the frame of the statistics of the fractional moments, (c) extraction of possible calibration parameters for possible calibration of the normalized spectra with respect to the number of CV cycles. These three basic steps are becoming effective for detection of the influence of some external factors. In our case it is important to detect the influence of the factor n characterizing CV cycles

    Vitamin A status of healthy children in Manisa, Turkey

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    <p>Abstract</p> <p>Background</p> <p>Vitamin A deficiency is a major public health nutrition problem in the developing world. Even subclinical Vitamin A deficiency is associated with increased childhood mortality. Severe maternal vitamin A deficiency may cause increased mortality in the first months of life. There have been a limited number of studies regarding vitamin A status in Turkey. The aim of this study was to assess vitamin A status of healthy children in Manisa, Turkey.</p> <p>Methods</p> <p>Vitamin A status of 100 healthy children aged 36-48 months is evaluated. The children were seen during routine examination. Serum retinol concentrations were measured by high-performance liquid chromatography. Duration of breast feeding, age solid foods introduced, use of supplementary vitamins, weight and height, and intake of specific groups of nutrients on a daily, weekly and monthly basis were collected from a questionnaire completed by the mothers. Height and weight z-scores were calculated according to national standards. Mothers of 20 of the 100 children were known to have normal serum and breast milk retinol concentrations. Children with normal serum retinol concentration were compared with the children with VAD. Student's t-test and Mann-Whitney test were used to compare independent variables. The Pearson correlation analysis test was used to test relation between numeric variables.</p> <p>Results</p> <p>Mean retinol concentration was 0.98 ± 0.32 μmol/L in the whole study group. Serum retinol concentrations were normal (>0.70 μmol/L) in 89% of the children. When children with normal serum retinol concentrations were compared with those with retinol concentrations lower than 0.70 μmol/L, there was no difference in terms of age, gender, weight and height at the time of study, z-scores, birth weight, birth length, duration of breast feeding, time to begin solid food, rate of supplementary vitamin use, and rate of infections (P > 0.05). There was not any relation between vitamin A concentrations and weight and height at the time of study, z-scores, birth weight, birth length, duration of breast feeding, time to begin solid food, vitamin use, and frequency of intake of specific groups of nutrients (P > 0.05).</p> <p>Conclusions</p> <p>This study showed that VAD is a moderate health problem in Manisa.</p

    Political connections and corporate financial decision making

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    This paper investigates whether and how political connections influence managerial financial decisions. Our study reveals that those firms that have a politician on its board of directors are highly leveraged, use more long-term debt, hold large excess cash and are associated with low quality financial reporting compared to their non-connected counterparts. These effects escalate with the strength of the connected politician and whether he or his party is in power. The winning party effect is observed to be stronger than victory by the politician himself. Overall, our paper provides strong evidence that political connection is a two-edged sword. It is indeed a valuable resource for connected firms, but it comes at a cost of higher agency problems

    Social self-efficacy of adolescents who participate in individual and team sports

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    This study was conducted to compare different variables of social self-efficacy (SSE) as determinants for adolescents in selecting and taking part in team and individual sports. Four sporting codes were selected for study: table tennis, swimming, handball, and basketball. Participants were 100 adolescents who had played their chosen sport for an average of 5.4 years. Results showed that the difference in SSE between those playing table tennis and those playing handball was significant, as was the difference between those playing table tennis and those playing basketball, swimming and handball, swimming and basketball. No statistical difference was found in SSE between those playing table tennis and those involved in swimming, and handball and basketball. Likewise, there was no statistically significant difference between SSE scores according to gender for any of the sports. Nor was there any significant difference between the socioeconomic status (SES) of the participants according to the sport they played and the arithmetic average of their SSE scores. A negative correlation was noted(p >.05) between the sporting code and the SES of participants. © Society for Personality Research

    Analysis of a nanofilm of the mercaptophenyl diazonium modified gold electrode within new statistical parameters

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    The main aim of this study is to characterize the nanosurface of the mercaptophenyl diazonium modified gold (Au) surface by a new statistical approach. In this study the gold electrode surfaces were self-assembled in ethyl alcohol by 1.0 mM mercaptophenyl diazonium. FT-IR spectra of the surface modifier molecules in both solid and nanofilm of mercaptophenyl diazonium (MCP-Au) forms were recorded in the spectral range of 600-4,000 cm-1. The FT-IR spectra of solid mercaptophenyl diazonium tetrafluoroborate salt were obtained by using KBr pellets. The above FT-IR spectra of both bare Au and its nanofilm of mercaptophenyl diazonium were processed by new statistical approach to reach optimal smoothing trend for the characterization of the modified electrode surface consisting of the nanofilm of gold-mercaptophenyl diazonium. In the frame of new statistical approach all measured spectra have been 'read' in terms of a set of universal statistical parameters. These new parameters help to establish the statistical proximity of the smoothed spectra compared and give a possibility to classify the measured spectra in accordance with new set of statistical and robust quantitative values. Besides, there is a possibility to receive the relative fluctuations and the smoothed spectra of the second order. So, thanks to new approach we do not loose any measured information: the smoothed spectra and accompanied them noise (relative fluctuations) can be analyzed separately for detection of possible influence of predominant external factors that can be essential for this type of measurements. Copyright © 2010 American Scientific Publishers All rights reserved

    Analysis of a nanofilm of the mercaptophenyl diazonium modified gold electrode within new statistical parameters

    No full text
    The main aim of this study is to characterize the nanosurface of the mercaptophenyl diazonium modified gold (Au) surface by a new statistical approach. In this study the gold electrode surfaces were self-assembled in ethyl alcohol by 1.0 mM mercaptophenyl diazonium. FT-IR spectra of the surface modifier molecules in both solid and nanofilm of mercaptophenyl diazonium (MCP-Au) forms were recorded in the spectral range of 600-4,000 cm-1. The FT-IR spectra of solid mercaptophenyl diazonium tetrafluoroborate salt were obtained by using KBr pellets. The above FT-IR spectra of both bare Au and its nanofilm of mercaptophenyl diazonium were processed by new statistical approach to reach optimal smoothing trend for the characterization of the modified electrode surface consisting of the nanofilm of gold-mercaptophenyl diazonium. In the frame of new statistical approach all measured spectra have been 'read' in terms of a set of universal statistical parameters. These new parameters help to establish the statistical proximity of the smoothed spectra compared and give a possibility to classify the measured spectra in accordance with new set of statistical and robust quantitative values. Besides, there is a possibility to receive the relative fluctuations and the smoothed spectra of the second order. So, thanks to new approach we do not loose any measured information: the smoothed spectra and accompanied them noise (relative fluctuations) can be analyzed separately for detection of possible influence of predominant external factors that can be essential for this type of measurements. Copyright © 2010 American Scientific Publishers All rights reserved

    Analysis of a nanofilm of the mercaptophenyl diazonium modified gold electrode within new statistical parameters

    Get PDF
    The main aim of this study is to characterize the nanosurface of the mercaptophenyl diazonium modified gold (Au) surface by a new statistical approach. In this study the gold electrode surfaces were self-assembled in ethyl alcohol by 1.0 mM mercaptophenyl diazonium. FT-IR spectra of the surface modifier molecules in both solid and nanofilm of mercaptophenyl diazonium (MCP-Au) forms were recorded in the spectral range of 600-4,000 cm-1. The FT-IR spectra of solid mercaptophenyl diazonium tetrafluoroborate salt were obtained by using KBr pellets. The above FT-IR spectra of both bare Au and its nanofilm of mercaptophenyl diazonium were processed by new statistical approach to reach optimal smoothing trend for the characterization of the modified electrode surface consisting of the nanofilm of gold-mercaptophenyl diazonium. In the frame of new statistical approach all measured spectra have been 'read' in terms of a set of universal statistical parameters. These new parameters help to establish the statistical proximity of the smoothed spectra compared and give a possibility to classify the measured spectra in accordance with new set of statistical and robust quantitative values. Besides, there is a possibility to receive the relative fluctuations and the smoothed spectra of the second order. So, thanks to new approach we do not loose any measured information: the smoothed spectra and accompanied them noise (relative fluctuations) can be analyzed separately for detection of possible influence of predominant external factors that can be essential for this type of measurements. Copyright © 2010 American Scientific Publishers All rights reserved

    Analysis of the effect of potential cycles on the reflective infrared signals of nitro groups in nanofilms: Application of the fractional moments statistics

    No full text
    The effect of the potential cycles on the reflective IR signals of nitro-groups in nanofilms was studied for the statistical characterization of nitrobenzene (NB) and nitroazobenzene (NAB)-modified glassy carbon (GC) surfaces. Both NB and NAB nanofilms were obtained by the electrochemical reduction of the diazonium tetrafluoroborate salts in acetonitrile using cyclic voltammetry (CV). The modified surfaces were denoted as GC-(NB)n and GC-(NAB)n, respectively, where n indicates the number of CV cycles performed during modification. Reflective IR signals of the normalized NB and NAB nanofilms and GC were used for the quantitative evaluation of the effect of the potential cycles on the reflective IR signals of nitro-groups in nanofilms. The detection and quantitative reading of the influence of number of CV cycles were realized in the frame of a new error controllable approach that was applied for analysis of all available set of data. This approach includes in itself the following basic steps: (a) the procedure of the division (normalization) on the GC spectra, (b) the comparison of the smoothed spectra for their statistical proximity in the frame of the statistics of the fractional moments, (c) extraction of possible calibration parameters for possible calibration of the normalized spectra with respect to the number of CV cycles. These three basic steps are becoming effective for detection of the influence of some external factors. In our case it is important to detect the influence of the factor n characterizing CV cycles
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