Study on the Efficiency of the Different units for Removing Metallic ions in Isfahan Water Treatment Plant

In this study, removal efficiency of heavy metals such as iron, manganese, copper and nickel were surveyed in various units of water treatment plant in IsfahanCity. Samples were taken from influent, before and after sedimentation and after filtration under standard condition. Concentration of heavy metals in each sample was measured by atomic absorption spectrophotometer. The results showed that removal efficiency of iron, manganese, copper and nickel were 71, 60, 79 and 40 percent, respectively. Experimental results currently showed low efficiency for the suitable removal of aluminum. So, the aluminum concentration in all the samples from the influent (2.03 mg l-1) and effluent (2 mg l-1) of the water treatment plant exceeded the EPA drinking water standard (50 \u3bcg l-1). It is concluded that using conventional treatment technology can reduce metal concentrations conform to internationally approved guidelines except for aluminum. @ JASE

Gluten sensitivity enteropathy in patients with recurrent aphthous stomatitis

<p>Abstract</p> <p>Background</p> <p>Gluten sensitive enteropathy (GSE) is an autoimmune enteropathy triggered by the ingestion of gluten-containing grains in susceptible individuals. Recurrent aphthous stomatitis (RAS) may be the sole manifestation of GSE. The aim of this study was to determine the prevalence of gluten sensitivity enteropathy (GSE) in a large group of patients with RAS and assess the efficacy of gluten free diet (GFD) on the improvement of aphthous lesions in those who were diagnosed with GSE.</p> <p>Methods</p> <p>Two hundred and forty seven patients with RAS were included. The patients had at least three aphthous attacks per year. Patients were screened by IgA anti-endomysial antibody (EMA), IgA anti tissue transglutaminase (TTG) and serum IgA level. Those with a positive serology underwent endoscopic biopsies of the duodenal mucosa and patients with negative serology were excluded. The diagnosis of GSE was based on a positive serological test and abnormal duodenal histology. For patients with GSE, gluten free diet was recommended.</p> <p>Results</p> <p>Six out of 247 RAS patients had positive TTG test alone, and one had positive EMA and TTG. All 7 patients with positive serologic tests underwent duodenal biopsies. Histological findings were compatible with GSE in all of them (Marsh I in four patients, Marsh II in two patients and Marsh IIIB in one another.). The mean age of GSE patients was 27.42 ± 10.56 (range, 13 to 40) years old. They were suffering from RAS for an average duration of 4.5 years. All of the 7 GSE patients had not responded to the routine anti-aphthae medications, including topical corticosteroids, tetracycline and colchicine. Four patients who adhered to a strict gluten-free diet showed noticeable improvement in their aphthous lesions over a period of 6 months.</p> <p>Conclusion</p> <p>A significant minority (e.g. 2.83%) of RAS patients have GSE. This could be compared with the 0.9% prevalence of GSE in the general population of Iran. This study suggests that evaluation for celiac disease is appropriate in patients with RAS. Additionally, the unresponsiveness to conventional anti-aphthae treatment could be an additional risk indicator.</p

Univariate parametric and nonparametric double generally weighted moving average control charts

Statistical process control (SPC) is a collection of scientific tools developed and engineered to diagnose unnecessary variation in the output of a production process and eliminate it or perhaps accommodate it by adjusting process settings. The task of quality control (QC) is of fundamental importance in manufacturing processes when a change in the process causes misleading results, this alteration should be detected and corrected as soon as possible. Statistical QC charts originated in the late 1920s by Dr. W. A. Shewhart provide a powerful tool for monitoring production lines in manufacturing industries. They are also have been implemented in various disciplines, such as sequential monitoring of internet traffic flows, health care systems, and more. Shewhart-type charts are effective in detecting large shifts in the process but ineffective in detecting small to moderate shifts. This blind spot allows small shifts (smaller than one standard deviation) to continue undetected in the process, thereby incurring larger total costs for manufacturers. This thesis addresses this issue by augmenting current time-weighted charts (charts that use all the information from the start of a process until the most recent sample/observation) with a Double Generally Weighted Moving Average (DGWMA) chart, leading to more effective process monitoring. The objective of this thesis is to provide the fundamentals and introduce the researcher/practitioner to the essentials of the univariate DGWMA chart from both parametric and nonparametric perspectives. Numerous concepts and characteristics of proposed DGWMA charts are discussed comprehensively. Theoretical expressions and detailed calculations have been provided to aid the interested reader to familiarize and study the topic more thoroughly. This thesis paints a bigger picture of the DGWMA chart in a sense that other time-weighted charts such as the Generally Weighted Moving Average (GWMA), Exponentially Weighted Moving Average (EWMA), Double Exponentially Weighted Moving Average (DEWMA) and Cumulative Sum (CUSUM) fall under this umbrella. Both real-life data and simulated examples have been embedded throughout the thesis. We make use of R and Mathematica software packages to calculate numerical results related to the run length distribution and its associated characteristics in this thesis. We only consider control charts for monitoring the process location parameter. However, our conclusions and recommendations are extendable for the process dispersion parameter. In this thesis, we consider the DGWMA chart as the main chart and the EWMA, DEWMA, GWMA, and CUSUM charts as special cases. The thesis consists of the following chapters with a short description for each chapter as follows: Chapter 1 provides a brief introduction to SPC concepts and gives a literature review in terms of background information for the research conducted in this thesis. The scope and objectives of the present research are highlighted in detail. Chapter 2 provides an overview and a theoretical background on the design and implementation of the DGWMA chart derived from the SPC literature review. The properties of the DGWMA chart, including the plotting statistic, the structure for the weights, the control limits (exact/steady-state), etc. are considered in detail. The weighting structure of the DGWMA chart and its special case are discussed and pictured to emphasize the impact of weights in increasing the detection capability of time-weighted charts. Three approaches are described and investigated for calculating the run length distribution and its associated characteristics for the DGWMA chart and its special case the DEWMA chart; this includes: (i) exact approach; (ii) Markov chain approach; (iii) Monte Carlo simulation. In Chapter 3 we develop a one-sided generalized parametric chart (denoted by DGWMA-TBE) for monitoring the time between events (TBE) of nonconformities items originating from the high-yield processes when the underlying process distribution is gamma and the parameter of interest is known (Case K) and unknown (Case U). A Markov chain approach is implemented to derive the run length distribution and its associated characteristics for the DGWMA and DEWMA charts. An exact approach is also used to derive closed-form expressions for the run length distribution of the proposed chart. Performance analysis has been undertaken to execute a comparative study with several existing time-weighted charts. The proposed chart encompasses one-sided GWMA-TBE, EWMA-TBE, DEWMA-TBE, and Shewhart-type charts as limiting or special cases. The CUSUM-TBE chart is also included in the performance comparison. The necessary design parameters are provided to aid the implementation of the proposed chart and finding the optimal design and near optima design that is useful for practitioners. Alternative discrete distributions are considered for the weights of the GWMA-TBE chart and a discussion is provided to address the connection between new weights originating from the suggested distributions and the chart’s capability in detecting shifts. As a result, one can design an optimal GWMA-TBE chart by replacing weights from the discrete Weibull distribution without the implementation of the double exponential smoothing technique. Chapter 4 focuses on developing a two-sided nonparametric (distribution-free) DGWMA control chart based on the exceedance (EX) statistic, denoted as DGWMA-EX when the parameter of interest is unknown (Case U) and the underlying process distribution is continuous and symmetric. An exact approach and a Markov chain approach are considered to calculate the run length distribution and its associated characteristics for the proposed chart. A performance comparison has been undertaken to execute analysis with other nonparametric time-weighted charts available in the SPC literature. The proposed chart en-compasses two-sided GWMA-EX, EWMA-EX, DEWMA-EX, and Shewhart-type charts as limiting or special cases. The CUSUM-EX chart is also included in the performance comparison Also, the performance of the proposed DGWMA-EX chart has been evaluated under different symmetric and skewed distributions in comparison with its main counterparts, and the necessary results and recommendations are provided for practitioners to design an optimal chart. Chapter 5 encloses this thesis with a summary of the research conducted and provides concluding remarks concerning future research opportunities.Thesis (PhD (Mathematical Statistics))--University of Pretoria, 2020.This research was supported in part by the National Research Foundation (NRF) under Grant Number 71199 and the postgraduate research bursary supported by the University of Pretoria. Any findings, opinions, and conclusions expressed in this thesis are those of the author and do not necessarily reflect the views of the parties.StatisticsPhD (Mathematical Statistics)Unrestricte

Study on the efficiency of the different units for removing metallic ions in Isfahan water treatment plant

In this study, removal efficiency of heavy metals such as iron, manganese, copper and nickel were surveyed in various units of water treatment plant in Isfahan City. Samples were taken from influent, before and after sedimentation and after filtration under standard condition. Concentration of heavy metals in each sample was measured by atomic absorption spectrophotometer. The results showed that removal efficiency of iron, manganese, copper and nickel were 71, 60, 79 and 40 percent, respectively. Experimental results currently showed low efficiency for the suitable removal of aluminum. So, the aluminum concentration in all the samples from the influent (2.03 mg l-1) and effluent (2 mg l-1) of the water treatment plant exceeded the EPA drinking water standard (50 µg l-1). It is concluded that using conventional treatment technology can reduce metal concentrations conform to internationally approved guidelines except for aluminum. Journal of Applied Sciences and Environmental Management Vol. 9(2) 2005: 61-6

Study on the Efficiency of the Different units for Removing Metallic ions in Isfahan Water Treatment Plant

In this study, removal efficiency of heavy metals such as iron, manganese, copper and nickel were surveyed in various units of water treatment plant in IsfahanCity. Samples were taken from influent, before and after sedimentation and after filtration under standard condition. Concentration of heavy metals in each sample was measured by atomic absorption spectrophotometer. The results showed that removal efficiency of iron, manganese, copper and nickel were 71, 60, 79 and 40 percent, respectively. Experimental results currently showed low efficiency for the suitable removal of aluminum. So, the aluminum concentration in all the samples from the influent (2.03 mg l-1) and effluent (2 mg l-1) of the water treatment plant exceeded the EPA drinking water standard (50 μg l-1). It is concluded that using conventional treatment technology can reduce metal concentrations conform to internationally approved guidelines except for aluminum. @ JASE

Study of Different Units Efficiency for Removing Metallic Ions in Isfahan Water Treatment Plant

Abstract: In this study, removal efficiency of heavy metals such as iron, manganese, copper and nickel were surveyed in various units of water treatment plant in Isfahan City. Samples were taken from influent, before and after sedimentation and after filtration under standard condition. Concentration of heavy metals in each sample was measured by atomic absorption spectrophotometer. The results showed that removal efficiency of iron, manganese, copper and nickel were 71, 60, 79 and 40 percent, respectively. Experimental results currently showed low efficiency for the suitable removal of aluminum. So, the aluminum concentration in all the samples from the influent (2.03mgl ) and effluent (2mgl ) of the water treatment plant exceeded the EPA drinking water -1 -1 standard (50µgl ). It is concluded that using conventional treatment technology can reduce metal -1 concentrations except aluminum below internationally approved guidelines

A double generally weighted moving average exceedance control chart

Since the inception of control charts by W. A. Shewhart in the 1920s, they have been increasingly applied in various fields. The recent literature witnessed the development of a number of nonparametric (distribution‐free) charts as they provide a robust and efficient alternative when there is a lack of knowledge about the underlying process distribution. In order to monitor the process location, information regarding the in‐control (IC) process median is typically required. However, in practice, this information might not be available due to various reasons. To this end, a generalized type of nonparametric time‐weighted control chart labeled as the double generally weighted moving average (DGWMA) based on the exceedance statistic (EX) is proposed. The DGWMA‐EX chart includes many of the well‐known existing time‐weighted control charts as special or limiting cases for detecting a shift in the unknown location parameter of a continuous distribution. The DGWMA‐EX chart combines the better shift detection properties of a DGWMA chart with the robust IC performance of a nonparametric chart, by using all the information from the start until the most recent sample to decide if a process is IC or out‐of‐control. An extensive simulation study reveals that the proposed DGWMA‐EX chart, in many cases, outperforms its counterparts.http://wileyonlinelibrary.com/journal/qre2020-02-01hj2018Statistic