Determination of cadmium and selected micronutrients in commonly used and traded medicinal plants in Turkey

BACKGROUND: Medicinal plants commonly used and traded in Turkey were monitored for their cadmium and selected micronutrient (copper, iron, manganese and zinc) content. RESULTS: Cadmium was not detected in any sample of licorice extract, linden flowers or nettle leaves. However, in the rest of the samples, cadmium was found in the range of 7–126 µg kg^?1, with the highest concentration in chamomile leaf. Of all the monitored trace elements, the highest concentration found was 520 mg kg^?1 iron in zahter. The highest copper, manganese and zinc concentrations were found in rose hips (24 mg kg^?1), Turkish oregano (58 mg kg^?1) and zahter (50 mg kg^?1), respectively. CONCLUSION: The results of the present study reveal that cadmium and trace element concentrations in medicinal plants commonly used as traditional medicines in Turkey are well below the critical levels. Copyright © 2007 Society of Chemical Industry     

Monitoring of count data time series: Cumulative sum change detection in Poisson integer valued GARCH models

This article presents a cumulative sum (CUSUM) monitoring approach for count-data time series. A seasonal integer-valued generalized autoregressive conditional heteroscedasticity (INGARCH(1,1)) time series model with Poisson deviates is used to develop a likelihood ratio test formulation to detect changes in the process accounting for temporal correlations and seasonality. Simulation studies show that the proposed CUSUM monitoring approach can provide significantly improved performance in applications where serial correlation or seasonality is prevalent. A case study with real traffic crash counts is presented to illustrate the application of the proposed methodology for roadway safety improvement.     

Accident and hazard prediction models for highway–rail grade crossings: a state-of-the-practice review for the USA

Railway Engineering Science - Highway–rail grade crossings (HRGCs) are one of the most dangerous segments of the transportation network. Every year numerous accidents are recorded at HRGCs...     

Examination of effective parameters for the production of expanded clay aggregate

It is important to know which parameters are effective for the manufacture of expanded clay aggregate and to determine how effective these parameters are on expansion. In this study, expansion tests were conducted by using samples from three separate fields to determine how different parameters influence manufacturing. Clay grain size, pellet size, temperature in the furnace and firing time were selected in the expansion tests as parameters. Their effect on production was evidenced separately. It was found that decreasing the clay size has a positive effect on expansion while a decrease in pellet size has a negative effect on it. Also, temperature in the furnace and the time period during which the clay remains in the furnace are critical values for the resultant aggregate quality. The conditions for optimum manufacturing were explained in detail.