Number Of Significant Factors Research Articles

A retrospective multidimensional comparison of microprocessor and mechanical knee users: Analysis of quality of life and satisfaction with the prosthesis.

Despite the demonstrated greater efficacy of microprocessor knees (MPK) over mechanical knees (MK), the latter is still widely used by persons with transfemoral amputation. Besides motivations related to local insurance policies, quality of life (QoL) and satisfaction with the prosthesis play a key role in user preference. The aim of this study is to compare QoL and satisfaction in a large sample of MPK and MK users and to assess how these outcomes are explained by clinical and demographic characteristics. Retrospective study. The study was conducted on 75 MPK and 60 MK users. Quality of life was assessed using the EuroQoL Five Dimensions and the EuroQoL Visual Analog Scale questionnaires. Satisfaction was assessed with the Satisfaction with Prosthesis questionnaire. All 3 instruments were self-administered. Univariate and multivariate regression analyses were conducted thereafter. The difference in satisfaction between MPK and MK users was not statistically significant. Significant differences were observed instead for QoL. From the univariate regression analysis, 6 factors were significant predictors of QoL and satisfaction. On multivariate analysis, the number of significant factors was reduced to 3, namely knee type, age at the first prosthesis, and experience with prosthesis. Type of knee and age at the first prosthesis significantly predicted QoL scores, explaining 12% of EuroQoL Five Dimensions and 25% of EuroQoL Visual Analog Scale variances. Age at the first prosthesis and experience with prosthesis predicted Satisfaction with Prosthesis scores in the multivariate model, explaining 25% of the variance. MPK affects QoL but not satisfaction, which is positively driven by patients' experience with prosthesis and negatively affected by the age at the time of the first prosthesis.

Socialist Feminism in the Select Poems of Maya Angelou

Maya Angelou is one of the most inspirational African-American poets, novelists, activists, and feminists, who has also been recognized as a prominent and influential voice in literature. This study aimed to engage in an analytical investigation of socialist feminism in the select poems of Maya Angelou using biographical approach and Johannna Brenner’s socialist feminism perspective. The select poems included Woman Work, Alone, On Working White Liberals, When You Come to Me, When I Think about Myself and Caged Bird. The research method of textual analysis was used in the literary investigation of the select poems. The study revealed that Maya Angelou had a challenging and colorful life. Her range of experiences from childhood to adulthood had influenced how she wrote. Her vision and legacy as mirrored in her works especially in her poetry continue to inspire others to fight for equality of all forms in the society. It was also found out that there are a number of significant factors that aided in the development of her work as a writer and a poet. Her life experiences along with her education recreated the way she saw the world. The sociocultural environment in Arkansas during her period also contributed to her profound writings. The salient characteristics of socialist feminism of Brenner such as representation of women, images of women at home and in the workplace and role of women in the society are highly evident in her body of work. As a socialist feminist, Brenner yearns to end the exploitation of women at home, in the workplace, and in the community. Since this research found out that Angelou is regarded a socialist feminist, it is recommended to analyze other types of feminism such as eco-feminism, liberal, and radical feminism to explore other salient characteristics of feminism embedded in Angelou’s works.

Factors Influencing Quiet Quitting and Employee Commitment in Casino Gaming Workplaces: Implications for Employee Retention Strategies

Maya Angelou is one of the most inspirational African-American poets, novelists, activists, and feminists, who has also been recognized as a prominent and influential voice in literature. This study aimed to engage in an analytical investigation of socialist feminism in the select poems of Maya Angelou using biographical approach and Johannna Brenner’s socialist feminism perspective. The select poems included Woman Work, Alone, On Working White Liberals, When You Come to Me, When I Think about Myself and Caged Bird. The research method of textual analysis was used in the literary investigation of the select poems. The study revealed that Maya Angelou had a challenging and colorful life. Her range of experiences from childhood to adulthood had influenced how she wrote. Her vision and legacy as mirrored in her works especially in her poetry continue to inspire others to fight for equality of all forms in the society. It was also found out that there are a number of significant factors that aided in the development of her work as a writer and a poet. Her life experiences along with her education recreated the way she saw the world. The sociocultural environment in Arkansas during her period also contributed to her profound writings. The salient characteristics of socialist feminism of Brenner such as representation of women, images of women at home and in the workplace and role of women in the society are highly evident in her body of work. As a socialist feminist, Brenner yearns to end the exploitation of women at home, in the workplace, and in the community. Since this research found out that Angelou is regarded a socialist feminist, it is recommended to analyze other types of feminism such as eco-feminism, liberal, and radical feminism to explore other salient characteristics of feminism embedded in Angelou’s works.

GROWING TREE METHOD FOR OPTIMISATION OF MULTIFACTORIAL EXPERIMENTS

Context. The task of planning multifactorial experiments is important in science and industrial production. In the context of competition, rising costs, and increasing efficiency, it is necessary to optimize plans for multifactorial experiments in terms of cost and time. To solve this problem, there are a number of approaches and methods, the choice of which for a competitive technical task is an important and difficult task. In this regard, there is a need to develop new methods for optimizing the cost (time) of multifactorial experiment plans, compare them with existing methods, and give recommendations for practical application in the study of real objects.
 Objective. The purpose of the study is to develop and test the method of growing trees, to evaluate its effectiveness in comparison with other methods. The following tasks has been solved to achieve this goal: the proposed method of growing trees has been implemented in the form of software; the method has been used to optimize plans for multifactorial experiments in the study of real objects; its effectiveness has been evaluated in comparison with other methods; recommendations for its use were given.
 Method. The proposed method of growing trees is based on the application of graph theory. The advantage of the method is the reduction of time for solving optimization problems related to the construction of optimal plans for multifactorial experiments in terms of cost (time) expenses. Another characteristic feature is the high accuracy of solving optimization problems.
 Results. The results of experiments and comparisons with other optimization methods confirm the efficiency and effectiveness of the proposed method and allow us to recommend it for the study of objects with the number of significant factors k ≤ 7. It is promising to further expand the range of scientific and industrial objects for their study using this method.
 Conclusions. A growing tree method has been developed for the optimization of multifactorial experimental plans in terms of cost and time expenditures, along with software that implements it using the Angular framework and the TypeScript programming language.
 The effectiveness of the growing tree method is shown in comparison with the following methods: complete and limited enumeration, monkey search, modified Gray code application, and bacterial optimization. The growing tree method is faster than complete enumeration and can be applied to optimize multifactorial experimental plans in terms of cost (time) expenses for objects with a number of factors k ≤ 7. In solving optimization problems, the method of growing trees gives better results compared to monkey search, limited enumeration and bacterial optimization.

Aspects Regarding the Effects of Some Influence Factors on the Uncertainty Budget of Optical Emission Spectrochemical Tests with Excitation by Spark or Electric Arc

Abstract In this work, a number of significant factors are highlighted that affect the optical emission spectrochemical tests with spark or electric arc excitation on stainless steels with multiple synergistic purposes such as: acquiring new knowledge, increasing the amount of information obtained about the material, increasing the efficiency and quality of the tests, the characterization of special purpose alloys and the assessment of their compliance with the specified requirements. In this direction, it requires both knowledge of testing methods (theoretical basis, test method, procedure related to the method, quality assurance testing) and the characteristics of the investigated materials. These aspects are necessary for the analysis of the test system and the most correct preliminary interpretation of the experimental results.

Job stress and mental health at work

In Japan, a study on mental health in workplace has expanded from tertiary to secondary and primary preventions of mental health disorders among employees. Recent movements suggest a trend of bringing numerous topics outside the industrial health, including those with perspectives from categories generally known as primordial prevention, such as enhancement of working life quality or improvement of work environment.First, according to the aforementioned trends, the present paper made an effort to organize the terms and concepts related to mental health disorders, which included the foundation for research and practice in this area as well as the outcomes of discussions on the tertiary and secondary preventions.Second, the primary models of work-related stress, along its impact on mental health, and the scales for assessing workers' mental health issues were discussed, which have been used in numerous studies since the 1990s. The introduction of those models and scales contributed immensely to the expansion of this field's research areas. However, a number of significant factors, most of which have social or cultural implications, can influence the connection between stress at workplace and health problems. Therefore, conducting large-scale study or systematic reviews targeting domestic cases exclusively is necessary to obtain evidence for establishing highly versatile measures against mental health problems in Japan.Third, in this regard, several noteworthy large-scale research projects in Japan are highlighted as a hope for encouraging such studies in this field. However, the occupational health practitioners' effort to understand the actual workplace situations where they attend to and to put the understanding into practice has been and will remain an indispensable attribute for them in the future.

Evaluation of Logistic Regression and Multivariate Adaptive Regression Spline Models for the Analysis of Factors Determining Entrepreneurial Success

The present research work aims at evaluating Logistic Regression (LR) and Multivariate Adaptive Regression Spline (MARS) models through comparing the results of analysis of factors contributing to entrepreneurial success in Madurai District. The study considered two financial indicators namely Profit Rate and Reinvestment Rate for defining success in entrepreneurial venture. It analysed five factors influencing entrepreneurial success among micro and small scale manufacturing enterprises in the district. Previous business experience was the most important factor contributing to entrepreneurial success, followed by Entrepreneur’s Training and Entrepreneurial orientation. Using Number of significant factors, Accuracy, Sensitivity and Specificity, the results of LR and MR models have been compared. The study validates that MARS model is more powerful and reliable than LR model in predicting the possibility of entrepreneurial success in the business venture.

Processing and evaluation of the results of a psychological experiment using PPP Statistica in the study of the seed separator of oil seeds

As a result of the analysis of technological methods of seed material separation and their technical support it is established that the main trends in the development of precision seed cleaning equipment are the creation of adaptive control systems that allow dynamic optimization of working modes without operator intervention. The process of separation of oilseeds is a complex system that is influenced by a large number of independent variables, and only some of them significantly affect the original parameter studied. Therefore, starting to find the optimal parameters or conditions of the studied phenomenon, it is necessary to determine in advance which independent variables are to be studied. The article presents the definition of the Kendall concordance coefficient and its statistical assessment with a priori ranking of the estimates of the influence of independent variables in a psychological experiment for a multivariate active experiment using Friedman's nonparametric analysis of variance with the use of PPP Statistica in the study of an oilseed separator. A method is proposed for determining the number of significant factors for obtaining the response function by resolving the exponential equations of transgression into areas of fast and slow fall using the proportionality coefficient of the linear equation. It was found that the assessment of the results of the psychological experiment by Friedman's analysis of variance using the PPP Statistica allows us to determine the Kendall concordance coefficient and perform its statistical assessment. To obtain a determination of the number of significant factors of the response function, it is proposed to use the exponential and linear equations of transgression together. So, for the case under consideration with a significance level of p = 0.000001, it can be argued that experts with a concordance coefficient W = 0.66967 argue that four factors - the length of the working chamber of the separator, the air flow speed, the height of the fan and the number of intake chambers most of all affect the performance of the oilseed separator. cultures.

Development and characterization of enzymatic biosensor based on lipase from porcine pancreas for propylparaben detection

Purpose The purpose of this paper is to study the immobilization of porcine pancreatic lipase (PPL), in an organic matrix by a covalent cross-linking method to sense propylparaben (PP) present in aqueous solution. Design/methodology/approach PPL immobilization was performed by the covalent cross-linking method, using bovine serum albumin (BSA) in the presence of saturated glutaraldehyde vapor (GA). The preparation of the enzymatic membrane involves the incorporation of porcine pancreatic lipase (PPL), bovine serum albumin (BSA) and glycerol into a phosphate buffer solution (PBS). Characterization of this sensor was performed by impedance spectroscopy (EIS) and scanning electron microscope (SEM). The effect of experimental conditions such as PPL activity, potential, scan rate, PP concentration, pH and presence of interfering elements were studied by cyclic voltammetry. Findings Under the optimal experimental conditions, a number of significant factors were optimized. The method exhibited good linearity in the range of 10–14 to 10–9 mol/L with a good correlation coefficient of 0.957, detection limit (LOD) of 3.66 × 10–15 mol/L and high sensitivity of 1.086 mA mol−1L. The authors also obtained a very good coverage rate of the surface equal to 91.44%, and hydrolytic activity of lipase is evaluated to 26.64 mmol min−1. The stability and the interference were also evaluated. The equivalent circuit used to explain the electrochemical behavior of modified electrode is a Randle circuit. Practical implications The main application of biosensors is the detection of biomolecules that are either indicators of a disease. For example, electrochemical biosensing techniques can be used as clinical tools to detect breast tumors, because these compounds (PP) were found in breast tumors. Originality/value The result registered in this paper indicates that the developed sensor is an efficient, fast, simple and inexpensive analytical tool that can be used for the analysis of water containing PP.

Comparison of fatigue resistance characteristics of aluminum alloys and carbon laminates

It is known that many researchers of the mechanical properties of layered composites claim that in comparison with traditional structural metals and alloys, composites have serious advantages, mainly associated with high specific characteristics of static and fatigue strength. It should be noted that a well-founded idea of the advantages of composites strength characteristics is of particular importance for the elements of aircraft structures, taking into consideration an extremely important issue of operation safety. Unfortunately, at least, such a reasonable conception with respect to fatigue resistance characteristics has not been formed yet, consequently, a number of points concerning application of laminated composites in aircraft structures remain unanswered. The article presents a method and an example of comparing the fatigue life of the specimens with the open hole made of modern aluminum aviation alloy 1163T7 and carbon laminate AS4-PW. An obvious advantage of fatigue life of carbon composite materials compared to aluminum alloy at room temperature is noted. On the basis of a number of significant factors to be considered, the specified advantage can be largely diminished. First of all, these factors include the following: effect of temperature and humidity and degradation of the resistance characteristics of layered composites after impact damage. Taking into account the effect of the listed factors, the results of the comparison for the fatigue resistance characteristics of the specimens under consideration are presented. It is noted that the mentioned comparison was carried out using experimental data for the specimens considered under cyclic loading with constant amplitudes as well as under irregular loading, therefore, the comparison results may be slightly different. Nevertheless, it is obvious that the similar comparison presents relevant interest and should be considered when drawing final conclusions about the advantages (or their absence) of the fatigue resistance characteristics of carbon laminates over aluminum alloys.

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The paper reveals regularities of grass projective cover variation depending on the level of recreational transformation of public green spaces, taking into account stand density and soil electrical conductivity. The hypothesis that herbaceous cover is positively influenced by moisture and trophicity of edaphotopes and the stand is an antagonist of herbaceous cover is confirmed. The nature of intra-ecosystem relationships of the park stand is influenced by the level of recreation. Assessment of the level of recreational transformation of the grass cover of green areas of public use is performed on the example of the park Novoalexandrovsky of Melitopol. Within the city park, the grass layer is influenced by natural and anthropogenic environmental factors. Based on the data on the hardness of the soil quantified the level of recreational load and set the following levels of recreational load: low level, below a moderate level, moderate level, above a moderate level and high level. Stand density is an important natural factor that affects the herb layer primarily through the regulatory function of access to sunlight. Quantitatively, trophicity and moisture can be estimated using the electrical conductivity index, which depends on both the amount of salts dissolved in the ground liquid (trophicity) and the moisture content. The obtained data show that electrical conductivity of soil within the park is on the average 0,11 ± 0,0037 dSm/m and in 95% of cases varies from 0 (electrical conductivity below the lower limit of device sensitivity) to 0,19 dSm/m. Observed electrical conductivity values are much less than critical values, so within the park, excessive salinity is not a limiting factor for herbaceous plant growth. Projective cover of the herbaceous layer is on average 2,60 ± 0,11%. In 95% of cases this indicator is in the range of 0‒10%. The level of variability of projective coverage is rather high ‒ 96,48%. Distribution asymmetry is significant and positive, indicating a significant shift in the distribution of this indicator towards small values. The kurtosis is also significant and positive, which indicates the predominance of modal values compared to the random alternative. The distribution of the projective coverage can be described as a mixture of two distributions with a normal law. The component with a lower mean of 0,76 ± 0,59% is 46,0% of the mixture, and the component with a mean of 3,63 ± 2,24% is 54,0% of the mixture. It should be noted that the Kolmogorov‒Smirnov test indicates a low level of explanatory power even for such a complex model. Therefore, it should be assumed that the variation of the projective cover of herbaceous cover is determined by a number of significant factors. According to the quantitative indicators of vegetation cover, the following levels of recreational load can be distinguished: low (combines small and less than moderate levels), medium (combines moderate and above moderate) and high (corresponds to the high level). Differences in projective cover within the smallest and below moderate level on the one hand, and medium and above moderate level on the other hand, are not statistically reliable.

DETERMINATION OF OIL AND OIL PRODUCT LOSSES FROM EVAPORATION WHEN LOADING VEHICLES

Background Losses of oil and oil products from evaporation when they are loaded into tankers, automobile and railway tanks at points that are not equipped with steam recovery units are inevitable. This also leads to environmental pollution and may lead to the formation of explosive concentrations in the air of the working area. Therefore, the control of losses of oil and oil products from evaporation at filling points is an urgent task. Aims and Objectives The purpose of this article is to develop a method for calculating losses of oil and petroleum products from evaporation at filling points. Results A formula has been obtained for calculating the loss of oil and oil products from evaporation based on the results of measuring the mass content of hydrocarbons in a vapor-air mixture. It is shown that the previously proposed formulas of P.R. Rivkin for this purpose do not take into account a large number of significant factors.

Ethnic differences on cardiovascular disease risk and quality of life in Selangor

Malaysia is currently experiencing an epidemiologic and demographic transition. Rapid urbanization and vast changes in lifestyles among the population has led to widespread cardiovascular disease (CVD) outcomes. Also, until now, the most prevalent cardiovascular risk factor has remained unknown among the Malaysian population. This study aimed to identify the most significant cardiovascular risk factor among multiethnic adults in Dengkil, Selangor. A case-control retrospective study comparing past exposure (retrospective) between the case (total cholesterol (TC) ≥ 5.18 mmol/L) and control groups (TC < 5.18 mmol/L) on CVD risk via guided questionnaire comprised of International Physical Activity Questionnaire (IPAQ), Food Frequency Questionnaire (FFQ), Depression, Anxiety and Stress Scales (DASS)-21 and SF-12 was carried out among 180 respondents aged 20 to 56 years in Dengkil, Selangor. In the present study, purposive and consecutive sampling were both applied to recruit respondents and also considering ethnic as a factor; thus, quota sampling was also conducted. The data were analyzed using Mann-Whitney, Kruskal-Wallis, Chi-Square, Independent Samples t-test and multiple logistic regression tests. The findings indicated there were no significant differences (p > 0.05) regarding all the risk factors between the case and control groups except for personal medical history (p < 0.05). Chinese possessed the highest number of significant risk and protective factors. Lastly, the quality of life of Malay controls was higher than that of cases in terms of Physical Component Summary (PCS). Generally, all the risk factors were independent in terms of total cholesterol status, except for personal medical history. The significance of risk factors and protective factors varies according to ethnicity.

Effects of Listening/Reading Comprehension and Morphological Awareness on First Graders’ Writing to Dictation: A Comparison of the Effect of Memorization

The purpose of this study was to determine whether the cognitive abilities of listening and reading comprehension and morphological awareness affect children’s writing to dictation. Data were collected from 194 first-grade elementary schoolchildren in South Korea on the effects of repetitive practice and memorization by comparing impromptu and one semester’s regular dictation tests. The results first revealed that spelling, spacing, and punctuation were highly correlated with the three cognitive abilities in the impromptu writing to dictation, but far less in the regular dictation test. Second, it was found that children’s listening and reading comprehension and morphological awareness influenced their spelling, while reading comprehension and morphological awareness affected spacing and punctuation significantly in the impromptu dictation test. However, in the case of the regular dictation test, which involved memorization, the number of significant factors was small, and final explanatory power of those cognitive abilities was much smaller.

Evaluating the influence of geometric distortions to the buckling capacity of stiffened panels

This study presents an effort to clarify the effects of initial geometric distortions to the buckling capacity of stiffened panels through numerical experimentation. Four types of imperfections have been considered, that is local (plate, web and stiffener) and global distortion types (column-like). These discrete types were considered as the factors that tend to affect the buckling capacity of the adopted finite element model. Statistical techniques of Design Of Experiments have been applied. A One Factor At a Time analysis along with a full factorial analysis have been performed for screening purposes, and the significant main and interaction effects have been evaluated. The Response Surface Method was finally employed so as to verify and narrow down the number of significant factors. From the four distortion types examined and for the particular involved collapse modes in the evaluated geometries, it was concluded that when the stiffened panel involves global distortion such that maximum global bending stress develops at the plate, then only local plate and web distortions are significant, while stiffener and global distortion may be neglected from the analysis. On the other hand, when global distortion maximizes the global bending stress at the stiffener top, then local web and this particular global distortion type have to be included.

Application of variable selection and dimension reduction on predictors of MSE\u2019s development

Nature create variables using its character component, and variables are sharing characters from a vary small to relatively large scale. This results, variables to have from a vary different to a more similar character, and leads to have a relation ship. Literature suggested different relation measures based on the nature of variable and type of relation ship exist. Today, due to having high variety of frequently produced large data size, currently suggested variable filtering and selection methods have gaps to full fill the need. This research desires to fill this gap by comparing literature suggested methods to finding out a better variable selection and dimension reduction methods. The result from regression analysis using all literature suggested factors shows that none of the predictors for development status of enterprise are significant, and only 10 predictors for number of employer in an enterprise are significant out of 81 factors. Since, variable selection and dimension reduction methods are applied to find out predictors of a response by removing variable redundancy, and complexity of incorporating large number variable. Based on statistical power, for the results from variable selection methods, specially association and correlation methods showed that, CANOVA more efficiently detects non-linear or non-monotonic correlation between a continuous–continuous and a continuous-categorical variables. Spearman’s correlation coefficient more efficiently detects a monotonic correlation between a continuous with a continuous, and a continuous with a categorical variable. Pearson correlation coefficient more efficiently detects the linear correlation between continuous variables. MIC efficiently detects non-linear or non-monotonic relation between continuous variables. Chi-square test of independence efficiently detects relation between a continuous with a continuous, and categorical with categorical variables, but the non linear or non monotonic relation between a continuous with a categorical are not well detected. On the other hand, the result from lasso and stepwise methods reveals that, the relation between the predictor and response due to interaction effect not detected by correlation and association methods are detected by stepwise variable selection method, and the multicollinearity is detected and removed by lasso method. Regressing the response variable “number of employer in an enterprise” based on variables selected by lasso and stepwise method does bring greater model fitness (based on adjusted R-squared value) than variables selected by association and correlation methods. Similarly, regressing the response variable “development status of an enterprise” based on variables selected by association and correlation methods does bring 12 significant variables, where none of variables are significant from variables selected by lasso and stepwise methods. As a result, 51 predictors for number of employment in an enterprise, and 40 predictors for development status of an enterprise are detected as significantly related variables. And, lasso and stepwise methods are preferred to select predictors of a continuous response variable “number of employers in an enterprise”, and association and correlation methods are preferred to select predictors of a categorical response variable “development status of an enterprise”. Finally, the reduced regression models result reveals that, 20 predictors have causal relation with number of employment in an enterprise, and 12 predictors have causal relation with development status of an enterprise. On the other hand, based on model fitness, information lost, and number of significant factors, principal factor is preferred and applied in dimension reduction for a categorical response variable “development status of an enterprise”, and factor score based regression is preferred and applied for a continuous response variable “number of employers in an enterprise”. However, the comparison of the results in variable selection and dimension reduction indicates that, variable selection methods gave more gain in model fitness than dimension reduction methods. Hence, the suggested variable selection methods are more preferred than dimension reduction methods, and applied to find out predictors. In general, the suggested procedure for variable selection methods are recommended when small number of variables are studied, and the suggested dimension reduction methods are recommended for large number of variant variables (Big data case).

Fabrication of polypyrrole-silver nanocomposite for hollow fiber solid phase microextraction followed by HPLC/UV analysis for determination of parabens in water and beverages samples

In the present study, a nanocomposite of polypyrrole-silver nanoparticles was made as a new sorbent of hollow fiber solid-phase microextraction method and it was utilized for the preconcentration and determination of trace amounts of parabens in water, fruit juice, and beer samples. Polypyrrole was synthesized by chemical oxidative polymerization on the wall surface of a hollow fiber. Then a green method was employed for the synthesis of silver nanoparticles on the polypyrrole. This coating showed impressive mechanical and chemical stability. Hollow fiber as solid phase microextraction fiber is conformable with complex matrices and exhibits high clean up and selectivity without memory effect due to its porosity. A number of significant factors were optimized. The limit of detection, under the optimal conditions, for all of the parabens was in 0.01 μg L−1. The method exhibited good linearity in the range of 0.05–200 μg L−1, with limit of quantification of 0.05 μg L−1, coefficients of determination better than 0.9990 and extraction recoveries of 25.0–28.0%. The intra- and inter-assay precisions (RSD%, n = 3) were in the range of 2.4–3.1 % and 3.4–4.2%, respectively. The relative recovery values for the spiked samples were in the acceptable range of 90.4–104.0%.

Multivariate statistical analysis for the assessment of groundwater quality under different hydrogeological regimes

Multivariate statistical analysis has been widely used for hydrogeochemical characterization of groundwater quality. In this study, hydrochemical data from three hydrological basins were used and two methods (factor and cluster analyses) were applied. The first area is the coastal area of Eastern Thermaikos Gulf where groundwater is influenced by seawater intrusion and geothermal fluids. The other two areas are the inland basins of Gallikos and Perdikas in which agricultural and industrial activities constitute the main anthropogenic pollution sources of groundwater. Initially, the aforementioned methods were applied for each area separately and resulted in a different number of significant factors and clusters, while the natural and anthropogenic influences were spatially determined in each area. Additionally, factor and cluster analyses were applied coupling data from all areas. Therefore, five clusters and three major factors were determined distinguishing the hydrochemical processes and impacts from anthropogenic activities in more detail. It is worth mentioning that the application of cluster analysis in the coupled groundwater samples of all studied areas resulted beneficially in the most hydrochemically complex area. Salinization dominates in the coastal area, while in Gallikos and Perdikas basins high concentrations of NO3 occur mainly due to agricultural activities and small livestock units. The numerous hydrochemical samples are identified as the main issue for the higher discretization and reliability of the second approach. Nevertheless, this study is associated with a number of limitations of multivariable statistical analysis regarding extreme concentrations of Cl and Na. This issue stimulates further research in overcoming and understanding these drawbacks.

Cross‐cultural differences in the content and presentation of web sites

PurposeInternet is set to be one of the main channels of distribution in the future and already greatly facilitates product evaluation thanks to the information available on the net. The main advantages of electronic shopping over other channels include the reduced costs of searching for products and for product‐related information. Research has stressed the importance of quality information in web site design. The perceived utility of a web site depends on the perceived utility of its content (i.e. quality of information on product characteristics) and its presentation of that content. This paper compares the ways in which a web site's content and content presentation affect the product choice of two consumer groups from different cultures. The paper aims to discuss these issues.Design/methodology/approachThe authors conduct an exploratory study to determine the key factors which may be used in a later conclusive research. The authors propose a tool based on the statistical design of experiments to determine the number of significant factors used by two market segments (Spanish and US students) when selecting a bottle of wine sold via a web site.FindingsThe authors identify key extrinsic factors of consumers' perceived utility when selecting a bottle of wine from a web site and analyse whether cross‐cultural aspects are significant in this choice. The authors assume that web site evaluations made by users from different geographical areas reflect their preferences for more familiar designs.Research limitations/implicationsThe sample size does not enable us to determine the significance of certain variables. Moreover, the sample is not fully representative of the overall consumer population, and so inferences cannot be made about all consumers. However, since the study is exploratory with a theoretical content, the results can be considered valid.Practical implicationsWeb page designers need to take into account the cultural characteristics of their target market in the presentation and content of their sites.Originality/valueThe internet marketing literature considers cultural differences in web design as a tool to improve user confidence and attitude. However, few studies have examined the effects of the cultural adaptation of web sites on user evaluations. Here, the authors propose a straightforward procedure for calculating the main effects of web site attributes. Yates' algorithm and the normal probability plot, proposed by Daniel, can be implemented in any spread sheet.

Reconceptualising and reframing graduate teaching assistant (GTA) provision for a research-intensive institution

This article describes an innovative curriculum design that has been created at a research-intensive university to prepare Graduate Teaching Assistants (GTAs) for their role as teachers within higher education. The underlying concepts and frameworks for the design of the programme are discussed in depth in an attempt to unpack the assumptions that are routinely made about GTAs, their training needs and requirements as students. The finished product was a more effective curriculum that took account of a number of significant factors throughout the design process. These factors included flexibility in terms of GTAs making their own choices about the direction of their learning, and the importance of discipline-based teaching to inform practice. Preliminary indicators, for example student evaluations and student focus group data suggest that the revised curriculum better addresses and responds to the needs of the GTAs than the previous curriculum.