On the Subrange and Its Application to the R-Chart

The conventional sample range is widely used for the construction of an R-chart. In an R-chart, the sample range estimates the standard deviation, especially in the case of a small sample size. It is well known that the performance of the sample range degrades in the case of a large sample size. In this paper, we investigate the sample subrange as an alternative to the range. This subrange includes the range as a special case. We recognize that we can improve the performance of estimating the standard deviation by using the subrange, especially in the case of a large sample size. Note that the original sample range is biased. Thus, the correction factor is used to make it unbiased. Likewise, the original subrange is also biased. In this paper, we provide the correction factor for the subrange. To compare the sample subranges with different trims to the conventional sample range or the sample standard deviation, we provide the theoretical relative efficiency and its values, which can be used to select the best trim of the subrange with the sense of maximizing the relative efficiency. For a practical guideline, we also provide a simple formula for the best trim amount, which is obtained by the least-squares method. It is worth noting that the breakdown point of the conventional sample range is always zero, while that of the sample subrange increases proportionally to a trim amount. As an application of the proposed method, we illustrate how to incorporate it into the construction of the R-chart.

Polycyclic Aromatic Hydrocarbon Risk Assessment and Analytical Methods Using QuEchERS Pretreatment for the Evaluation of Herbal Medicine Ingredients in Korea

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic and mutagenic compounds that are often formed during the thermal processing of herbal medicine ingredients. In this study, the concentrations of four PAHs (PAH4) in various herbal medicine ingredients were monitored. Further, the QuEChERS method was used to replace conventional pretreatment, a more complex and cumbersome approach. The recovery range of the QuEChERS method ranged between 89.65–118.59%, and the average detection levels of benzo[a]anthracene (BaA), chrysene (CHR), benzo[b]fluoranthene (BbF), and Benzo[a]pyrene (BaP) in 50 herbal medicine ingredients were 0.18, 0.27, 1.13, and 0.17 μg/kg, respectively. The BaP and PAH4 levels in all tested samples were deemed safe according to risk characterization analyses based on European Union and Korean guidelines. Therefore, our findings indicated that the QuEChERS method could be used as an effective alternative to conventional sample pretreatment for the analysis of herbal medicine ingredients.

A hand-powered microfluidic system for portable and low-waste sample discretization

In this work, we present a simple and equipment-free system for discretizing samples into tens of thousands of discrete volumes in tens of seconds. Unlike conventional sample discretization systems that...

The Use of Oral Motor Exercises among Speech Language Pathologists in Jordan

The paper aims to study the Speech Language Pathologists (SLPs) use of oral motor exercises (OMEs) with patients who present with speech disorders. It also assesses the nature and kind of exercises used by these (SLPs). Furthermore, it compares the outcome with other studies targeted oral motor exercises. A conventional sample of 75 (SLPs) in Jordan was handed a survey to fill and (50) participants (67%) completed and returned the surveys. The (SLPs) work in different treatment settings: (clinics, speech centers, universities, and private practice), and they have B.S, M.A., or Ph.D. degree, in Speech and Language Pathology. The (SLPs) experience ranged from two years to twenty years. Results showed that 74% of (SLPs) use (OMEs), which is a very high percentage. The choice of using oral motor exercises was not affected by the level of education or the years of experience. As for the nature of exercises, tongue exercises were used by the majority of (SLPs). Based on the results, it seems that most of the recent studies do not support the use of oral motor exercises. However, more effort is needed in research in order to give a solid proof of the importance/ no value of (OMEs). (SLPs) need studies that are proved clinically by tracking cases in details.

Studies on dyeing properties of chitosan modified cellulosic fiber

This paper presents the possibility of salt free dyeing of cotton fabric with reactive dye by treating the cotton with chitosan from fish scale and used as a salt for dyeing of cotton with reactive dye. Cellulosic fiber acquires negative charge in aqueous medium and thus repels negatively charged dye anion during dyeing. Such repulsion between fibre and dye is offset by using large quantity of salt in dye bath, particularly for reactive dyes. A low dye bath exhaustion also leads to low dye fixation of reactive dyes on cotton. Therefore the discharged wastewater from dye house creates avoidable environmental threats due to very high dye concentration. Hence, surface modification of cotton to increase dye-fibre interaction is thus the best route to overcome the lack of affinity of cotton to reactive dyes making salt-free reactive dyeing. In this investigation an attempt was made to modify cotton with chitosan extracted from fish scales. The chitosan modified cotton was dyed with reactive dye and compared with the conventional dyed cotton. The color strength of the modified cotton fabric was better than that of conventional sample which is 18.88 and 18.02 respectively. Better fastness properties were experienced in treated cotton sample than the ordinary sample. The fastness properties obtained were better than the conventional sample. From this investigation it was revealed that surface modification of cotton by treatment with chitosan provided better dyeing properties and it can be the best possibility for salt free dyeing of cotton.

Sample Size Equation of Mechanical System for Parametric Accelerated Life Testing

This chapter proposes how to decide the sample size. Due to cost and time, it is unfeasible to carry out the reliability testing of product with many samples. More studies on testing methods should explain how to decrease the sample size. To provide the accurate analysis for product reliability in the bathtub curve, Weibull distribution is chosen. Based on Weibayes method, we can derive the sample size equation from the product BX life. As the reliability of product is targeted and the limited sample size is given, we can determine the mission cycles from new sample size equation. Thus, by applying the accelerated loading to mechanical product, we can reveal the design failures of product and confirm if the reliability target is achieved. Comparing conventional sample size equation, this derivation of sample size equation is helpful to evaluate the lifetime of mechanical product and correct its design problems through parametric accelerated life testing (ALT). This equation also might be applicable to develop the test method of all sorts of structure in the civil engineering.

Online Worker Fraud and Evolving Threats to the Integrity of MTurk Data: A Discussion of Virtual Private Servers and the Limitations of IP-Based Screening Procedures

ABSTRACT We identify a pervasive, yet previously undocumented threat to the reliability of MTurk data—and discuss how this issue is symptomatic of opportunities and incentives that facilitate fraudulent behavior within online recruitment platforms. In doing so, we explain how IP addresses were never intended to identify individuals and are likely insufficient to identify and mitigate emergent risks around data integrity. We discuss MTurk samples for two studies that include alarming proportions of participants who circumvent an entire set of conventional sample screening methods—and provide disturbingly low-quality responses. These “bad actors” exploited inherent limitations of IP screening procedures by using virtual private servers (VPS) that concealed the IP address of their local devices. While service providers now help target this abuse, the underlying limitations of IP screening procedures remain. Our findings emphasize the importance of continued diligence within the research community to identify and mitigate evolving threats to data integrity.

Microwave-Based Technique for Fast and Reliable Extraction of Organic Contaminants from Food, with a Special Focus on Hydrocarbon Contaminants

Due to food complexity and the low amount at which contaminants are usually present in food, their analytical determination can be particularly challenging. Conventional sample preparation methods making use of large solvent volumes and involving intensive sample manipulation can lead to sample contamination or losses of analytes. To overcome the disadvantages of conventional sample preparation, many researchers put their efforts toward the development of rapid and environmental-friendly methods, minimizing solvent consumption. In this context, microwave-assisted-extraction (MAE) has obtained, over the last years, increasing attention from analytical chemists and it has been successfully utilized for the extraction of various contaminants from different foods. In the first part of this review, an updated overview of the microwave-based extraction technique used for rapid and efficient extraction of organic contaminants from food is given. The principle of the technique, a description of available instrumentation, optimization of parameters affecting the extraction yield, as well as integrated techniques for further purification/enrichment prior to the analytical determination, are illustrated. In the second part of the review, the latest applications concerning the use of microwave energy for the determination of hydrocarbon contaminants—namely polycyclic aromatic hydrocarbons (PAHs) and mineral oil hydrocarbons (MOH)—are reported and critically overviewed and future trends are delineated.

Analysis of Cuban nickeliferous minerals by laser-induced breakdown spectroscopy (LIBS): non-conventional sample preparation of powder samples

In the present study, a new method to quantify Al, Cr, Fe, Mg, Mn, and Ni in nickeliferous minerals by laser-induced breakdown spectroscopy (LIBS) is proposed.

A new approach of using polyethylene frits for the quantification of sulphur in copper metals by isotope dilution LA-ICP-MS and comparison with conventional IDMS techniques

Polyethylene (PE) frits were used to quantify sulphur in copper and its alloys by isotope dilution combined with LA-ICP-MS as an alternative approach to conventional sample preparation.