Browse

You are looking at 1 - 10 of 77,464 items for

Abstract

The laboratory micro X-ray diffraction (μ-XRD) technique is a suitable method to study minerals in-situ in whole-rock specimens without any sample preparation or in polished thin sections, and even in small amounts in powdered form. The micro X-ray diffraction method uses the conventional, closed-tube X-ray generator, but modifications were needed in the diffraction column, sample holder and detector in order to achieve μ-XRD capability.

In this paper, we present a case study of the capillary method used in µ-XRD on hydrothermal clay mineral assemblages that formed in the Velence Mts (Hungary). The capillary method in µ-XRD has many advantages in the investigation of small amounts of clay minerals: (1) easy and rapid preparation of randomly oriented, powdered samples; (2) rapid measurements; (3) accurate diffraction patterns. By using the capillary method, the formation of preferred orientation can be eliminated; thus the (hkl) reflection of the clay minerals can be precisely measured. Illite polytype quantification and the investigation of (060) reflection of clay minerals can be used satisfactorily in µ-XRD.

Hydrothermal clay mineral assemblages are indicative of temperature and pH. Their examination can determine the physicochemical parameters of the hydrothermal fluids that interacted with the host granite in the Velence Mts. The analyzed hydrothermal clay minerals from the western part of the mountains suggest lower temperatures (150–200 °C) and intermediate pH conditions. In contrast, the clay mineral assemblages' characteristics for the eastern part of the mountains indicate more intense argillization and higher temperatures (∼220 °C) and intermediate pH conditions.

Open access
Authors: Afework Tsegaye, Joachim Bjørne, Anita Winther, GyÖngyi KÖkÖnyei, Renáta Cserjési and H.N. Alexander Logemann

Abstract

Background and aims

Previous studies suggest that attentional bias and disengagement may vary as a function of Body Mass Index (BMI), most notably in a palatable food related context. Though this could indeed represent a food context specific effect, it could also represent a general reward related context effect. In addition, though mindfulness and stress have both been reported to affect attention, it is not yet clear whether these moderate the relationship between BMI and attention as a function of reward context. In the current study we addressed these questions. It was hypothesized that BMI would be positively associated with bias in a food context and money context relative to a neutral context. The inverse was expected for disengagement. It was expected that mindfulness would decrease these relationships and for stress the inverse was expected.

Methods

In the current online study, eighty-seven participants (24 males and 63 females; age: M = 30.1, SD = 8.3; BMI: M = 24.2, SD = 4.67), filled out questionnaires and completed a visuospatial cueing task measuring attention and disengagement of attention in a neutral, food-related, and money-related condition.

Results

There was no association between BMI and attentional bias. Higher BMI was associated with faster responses to money pictures presented opposite to a cued location as compared to money pictures that did not follow a predictive cue. Our results do not support a clear moderating role of mindfulness and stress.

Discussion and conclusion

Our results imply faster processing and associated quicker responding to unanticipated reward-related stimuli in individuals with overweight or obesity.

Open access

Abstract

Background

Desire thinking is a voluntary cognitive process that involves the perseverative focus on memories, images and information related to a desired target. The aim of the present study was to validate the Hebrew version of the Desire Thinking Questionnaire (DTQ; Caselli & Spada, 2011) in a sample of adolescents and to investigate its relationship with measures of thought suppression, impulsivity and individual-based compulsive sexual behaviour.

Methods

In Study 1, a convenience sample of 718 adolescents completed the newly translated Desire Thinking Questionnaire in Hebrew (DTQ-H) and results were subjected to an Exploratory Factor Analysis (EFA). In Study 2, a convenience sample of 379 adolescents completed a battery of questionnaires including the DTQ-H. A Confirmatory Factors Analysis was performed on the DTQ-H and validity was ascertained by correlating with other measures.

Results

In Study 1, a 9-item two-factor structure was identified. A 6-item two-factor structure was confirmed in Study 2. Results also indicated that the DTQ-H has acceptable levels of reliability, and good concurrent and incremental validity in predicting compulsive sexual behaviour.

Conclusions

The 6-item DTQ-H appears to be a reliable and valid measure of desire thinking and may be used also on adolescents – an understudied population.

Open access

Abstract

Background and aims

The Brief Screener for Substance and Behavioral Addictions (SSBAs) was developed to assess a common addiction construct across four substances (alcohol, tobacco, cannabis, and cocaine), and six behaviors (gambling, shopping, videogaming, eating, sexual activity, and working) using a lay epidemiology perspective. This paper extends our previous work by examining the predictive utility of the SSBA to identify self-attributed addiction problems.

Method

Participants (N = 6,000) were recruited in Canada using quota sampling methods. Receiver Operating Characteristics (ROCs) analyses were conducted, and thresholds established for each target behavior's subscale to predict self-attributed problems with these substances and behaviors. For each substance and behavior, regression models compared overall classification accuracy and model fit when lay epidemiologic indicators assessed using the SSBA were compared with validated screening measures to predict selfattributed problems.

Results

ROC analyses indicted moderate to high diagnostic accuracy (Area under the curves (AUCs) 0.73–0.94) across SSBA subscales. Thresholds for identifying self-attributed problems were 3 for six of the subscales (alcohol, tobacco, cannabis, cocaine, shopping, and gaming), and 2 for the remaining four behaviors (gambling, eating, sexual activity, and working). Compared to other instruments assessing addiction problems, models using the SSBA provided equivalent or better model fit, and overall had higher classification accuracy in the prediction of self-attributed problems.

Discussion and conclusions

The SSBA is a viable screening tool for problematic engagement across ten potentially addictive behaviors. Where longer screening tools are not appropriate, the SSBA may be used to identify individuals who would benefit from further assessment.

Open access

Abstract

Due to recent changes in the labour market, recruitment and retaining employees have become more important than ever. Research dealing with the appearance of new generations in the labour market has found that they are less loyal to their employers, have high demands, and the key factors that they consider when choosing a job are salary, career opportunities, working environment, and work-life balance. As numerous studies in recent years have proved the importance of a healthy lifestyle in the context of labour, the question has arisen whether opportunities for sport participation and services supporting the well-being of employees have an influence on young people when they are seeking employment. We carried out an online survey to find out what students of the University of Debrecen think about the issue. The results were in line with the findings of previous studies, that is, young people look for high salaries, good working conditions, work-life balance and career opportunities when choosing a job. However, respondents did not identify sports opportunities and well-being benefits as major factors Yet, we found significant differences between different groups in terms of preference of particular factors, depending on sex, marital status, and whether someone does physical exercises regularly, and whether someone works while attending a university course or not.

Open access
Authors: Adebayo Surajudeen Adekunle, Adekunle Akanni Adeleke, Peter Pelumi Ikubanni, Peter Olorunleke Omoniyi, Tajudeen Adelani Gbadamosi and Jamiu Kolawole Odusote

Abstract

Heat treatment industries require various quenching media to improve the properties of the materials to be quenched. Petroleum based mineral (PBM) oil, a non-biodegradable oil, is popular amongst others quenchants in heat treatment processes. Recently, biodegradable oils mostly in their raw, unblended and unbleached forms have been employed for quenching of various engineering materials. Therefore, the present study examined the effects of some selected bio-quenchants in blended raw (BR) and blended bleached (BB) forms on the mechanical properties and microstructure of solution heat treated aluminum (Al)-alloy. Edible vegetable oil (70% by volume) was blended with 30% by volume of jatropha oil to form the bio-quenchant oils. Another set of bio-quenchants were formed by bleaching the raw oils before mixing so as to reduce the oxidation level and contaminations in the oil. The Al-alloy is solution heat treated at 500 °C and soaked for 15 min in an electric muffle furnace before quenching in the various established bio-quenchants. Results showed that samples treated in blended raw melon (BRM) oil have higher tensile strength of 151.76 N/mm2 while samples quenched in blended bleached melon (BBM) oil have higher hardness value of 61.00 HRC. In accordance to the results obtained the bio-quenchants were found to be effective replacement to the PBM oil.

Open access

Abstract

The faulty hormonal imprinting theory (published in 1980) and the DOHaD (Developmental Origin of Health and Disease theory (published in 1986) are twin-concepts: both justify the manifestation after long time (in adults) diseases which had been provoked in differentiating cells (e.g. during gestation). This was demonstrated using animal experiments as well, as comparative statistical methods (in human cases). However, there is no explanation for the tools of memorization (even after decades) of the early adversity and the tools of execution (manifestation) in adult age. It seems likely that immune memory is involved to the memorization of early adversity, up to the manifestation of the result (non-communicable diseases). Nevertheless, the relatively short timespan of adaptive immune memory makes this system insuitable for this function, however the newly recognized trained memory of the innate immune system seems to be theoretically suitable for the storage of the records and handling the sequalae, which is the epigenetic reprogramming in the time of provocation, without changes in base sequences (mutation). The flawed (damaged) program is manifested later, in adult age. Evidences are incomplete, so further animal experiments and human observations are needed for justifying the theory.

Open access

Abstract

The article highlights the worldwide dissemination of precision agriculture scientific researches published from the period of 1996–2018, data gathered in the Scopus citation database, using the science mapping method. The findings show that there is a constant rise in the number of publications in precision agriculture. The USA is not only leading in the adoption of precision agriculture technologies but also in the publication of papers, accompanied by China placed in second place. The most frequent keywords highlighted the main topics authors concentrated on more, and the national affiliation of most cited papers was the USA. The main prominence and contributions of the results present scientific research trends in precision agriculture in the last two decades, and demonstrate the main countries, authors and organizations who have contributed, and were more productive in this area.

Open access

Abstract

The main idea of the current paper consists in introducing the fractional order calculus in a control system. To control the system, an adaptive control technique with reference model is used. The fractional order models for the plant and reference model are obtained. To achieve the performances imposed by the fractional order reference model, a fractional order adaptive control law is proposed, which is a combination of two methods (MIT and Lyapunov stability). The original contribution in this paper is the use of fractional order calculus in the combined MIT and Lyapunov stability method and showing the dynamic behavior of the system. Several simulations are used to emphasize the effectiveness and benefits of the proposed method.

Open access
Authors: Ajkay Klára, Bagdy Emőke, Dobos Emőke, Erdélyi Ildikó, Falus Ferenc, Kapusi Gyula and Pajor András

Írásunk a Pszichodráma Műhelycsoport (röviden MCS) együtt gondolkodó emlékezésének terméke. Arra törekedtünk, hogy mindmáig aktív csoportéletünk keletkezését is abba a történeti folyamatba ágyazzuk, amelyben a “Lipótmezőn” megtörtént a klinikai pszichológia honfoglalása”. Mérei Ferenc, “a Tanár úr” teremtő és alapító személyisége a hazai klinikai lélektan gyakorlatának. Emlékezésünkben Mérei Ferenc személyiségét, tanári mivoltát, pszichológusi hivatásszemélyiséget formáló munkáját szeretnénk láttatni, érzékeltetni. Rorschachozásra tanítása is szerves részét képezte annak a szakmára nevelő munkának, amelyben egységes volt az elméleti tudás követelménye, a gyakorlat (a “csinálás”, ahogyan Ő nevezte) és a pszichológusi magatartás csiszolgatása. Ez az írás Mérei alkotó tehetsége iránti tiszteletünk kifejezése és szakmateremtő tevékenységének mementója. Az írásban az emlékező gondolkodás egyes tématerületei szerinti kérdéseinket követjük, ekképpen nyolc kérdésre válaszolunk.

This paper is the result of the collaborative and commemorative work of the “Psychodrama Workshop Group” (hereafter WG). Our aim was to embed the origins of our group, which is still active today, in historical processes such as the “conquest” of clinical psychology that occurred in the “Lipótmező”.

Ferenc Mérei, widely known as “the teacher”, was the creator and founder of the Hungarian clinical psychology practice. With this commemorative project, we aim to present Mérei’s personality, his teaching philosophy and his work in framing the psychological profile of the profession.

His teaching of' “Rørschaching” was an integral part of his professional educational work, which combined the necessity of theoretical knowledge with psychology practice (“doing”, as he called it) and the development of psychologists’ professional habitus. This paper thus expresses our respect for Mérei’s creative talent and serves as a memento to his activities in shaping the profession. To this end, we pursue eight specific questions that are informed by our commemorative approach.

Open access