Application of the Doehlert Design to Optimize the Signal Obtained in Photochemically Induced Fluorescence for the Determination of Eight Phenylureas

Abstract This work describes the optimization of a photochemically induced method for the detection of eight phenylureas has been developed by response surface methodology (RSM). These pesticides do not show native fluorescence but they were photolyzed into strongly fluorescent photoproducts under UV irradiation. The effect of the main variables affecting the yield of the photoderivatization reaction, and hence the fluorescence intensity, such as solvent, UV irradiation time and pH were optimized for each pesticide. A Doehlert design was applied in order to obtain maximum intensity fluorescence using response surface methodology. In general, a maximum was found for all pesticides using MeOH as organic solvent, except for diuron, whereas the effect of pH and irradiation time was different, according to each pesticide. Finally, the addition of β-cyclodextrin upon the photochemically induced fluorescence intensity was investigate. The fluorescence intensity was only improved for monolinuron at a concentration of 4×10 −3 M of β-cyclodextrin

Voltammetric Determination of the Herbicide Linuron Using a Tricresyl Phosphate-Based Carbon Paste Electrode

This paper summarises the results of voltammetric studies on the herbicide 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea (Linuron), using a carbon paste electrode containing tricresyl phosphate (TCP-CPE) as liquid binder. The principal experimental conditions, such as the pH effect, investigated in Britton-Robinson buffer solutions (pH 2.0–7.0), the peak characteristics for the analyte of interest, or instrumental parameters for the differential pulse voltammetric mode were optimized for the method. As found out, the best electroanalytical performance of the TCP-CPE was achieved at pH 2.0, whereby the oxidation peak of Linuron appeared at ca. +1.3 V vs. SCE. The analytical procedure developed offers good linearity in the concentration range of 1.25–44.20 μg mL−1 (1.77 × 10−4–5.05 × 10−6 mol L−1), showing—for the first time—the applicability of the TCP-CPE for anodic oxidations in direct voltammetry (without accumulation). The method was then verified by determining Linuron in a spiked river water sample and a commercial formulation and the results obtained agreed well with those obtained by the reference HPLC/UV determination

اعداد نموذج لحساب التكلفة الطارئة في مشاريع الابنية في قطاع غزة باستخدام تحليل الانحدار المتعدد

Construction projects in the Gaza Strip are facing many risks and uncertainties that lead to cost overrun. However, in practice, the contractors may be unable to make appropriate pricing allowances for risk. Estimating cost contingency allocation accurately in a bidding process is one of the key success factors of project risks management. However, there may be no flexible and rational method in estimating cost contingency has been developed. This research aims to develop a mathematical model based on multiple linear regression to be used by the contractors as a guideline for estimating cost contingency of building projects in the Gaza Strip during bid submission phase. The literature review and semi-structured interviews was used at the preliminary stage to identify 6 main risk factors associated with 74 sub-factors affecting cost contingency estimation. A questionnaire was developed and used as a research tool to obtain the opinions of 87 contractors on the most important factors affecting cost contingency. The opinions of 29 owners were also investigated to support the study. Factor analysis technique has been applied to identify the most significant independent variables for regressing analysis. The results yielded 36 independent variables categorized into 6 main risk factors affecting cost contingency estimation. The best proposed model of cost contingency estimation was developed by using Fully Modified Least Squares (FM-OLS) multiple regression analysis. The proposed model was applied on the cases of three implemented projects. Then, the model has been adjusted to increase its performance. The results of applying the adjusted model on the same three case studies indicated that the adjusted model could predict the cost contingency amount with high accuracy. The modified model has been able to measure the cost contingency successfully up to 90% of the real cost. The study recommended that the contractors have to use the adjusted proposed model as a tool to allocate the cost contingency for building projects, to develop overall risk management system to decrease the cost contingency amount. The study recommended the owners to share the contractors in risks and compensate them for risk costs beyond their control

Analysis of Brand Awareness and Guerrilla Marketing In Iranian SME

This research aims at analyzing and investigation of role of brand and guerrilla marketing in keeping and increasing purchasing portfolio of customer in Iran‟s SME and in this respect three hypothesizes are developed. For doing of this research after exploration of models and approaches in brand questionnaire and guerrilla marketing were used for customers of company. The conceptual model based on primary and sub hypothesizes were designed. For gathering data, two questionnaires were used for integration of guerrilla marketing and brand awareness. The research hypotheses were tested by correlation test, all the hypotheses were verified. The sequences of priorities in brand awareness were marketing budget, perceived quality of main product of one brand, perceived proportion of main product of one brand. There was a significant relationship between guerrilla marketing and brand awareness in Iran's SME. Also it was concluded that substitution capability of main product of one brand with mean of 1.73, perceived proportion of main product of one brand by mean of 2.04, marketing budget item by mean of 2.99 and, perceived quality of main product of one brand with mean of 3.10 were first to fourth priority respectively

Organizational suggestion system in the era of holding by developing an innovative model : the case of bonyade ta avon holding in Iran(an applied model)

One of the popular ways of taking advantage of personnel creativity is through suggestionsystems. Our main question is how to implement suggestion system in holding with conglomeratestructure. The paper presents an innovative model that were named ITFSK Model with accordanceof Bonayade Taavone (a holding that has many companies and institutions with conglomeratestructure). ITFSK is a model that explains how participation management and suggestion system isimplemented effectively in huge Enterprises (holding) and this approach brings continuousimprovement (kaizen) and it impacts the productivity of these enterprises.The paper is based on field research and the research in Bonyade Tavan that has 22 companies and2 institutions that activity fields of the subholdings is very varied.Our model consists of five main parts such as ideas bank, think-tank, feedback, sharing ofknowledge and kaizen that was named ITFSK.Implementation of “Suggestion system” rules has immediate and significant effects on theproductivity of activities in the jobs, thus influencing the performance of processes in the analyzedorganization. Suggestion system can result in kaizen and innovation in environment oforganization.The model was used to implement and evaluate a suggestion system of holding with conglomeratedstructure. The application of the model to evaluate the suggestion system provided some goodinsights and highlighted some areas of improvement