Opole University of Technology

Providing food and other products to a growing human population while safeguarding natural ecosystems and the provision of their services is a significant scientific, social and political challenge. With food demand likely to double over the next four decades, anthropization is already driving climate change and is the principal force behind species extinction, among other environmental impacts. The sustainable intensification of production on current agricultural lands has been suggested as a key solution to the competition for land between agriculture and natural ecosystems. However, few investigations have shown the extent to which these lands can meet projected demands while considering biophysical constraints. Here we investigate the improved use of existing agricultural lands and present insights into avoiding future competition for land. We focus on Brazil, a country projected to experience the largest increase in agricultural production over the next four decades and the richest nation in terrestrial carbon and biodiversity. Using various models and climatic datasets, we produced the first estimate of the carrying capacity of Brazil's 115 million hectares of cultivated pasturelands. We then investigated if the improved use of cultivated pasturelands would free enough land for the expansion of meat, crops, wood and biofuel, respecting biophysical constraints (i.e., terrain, climate) and including climate change impacts. We found that the current productivity of Brazilian cultivated pasturelands is 32–34% of its potential and that increasing productivity to 49–52% of the potential would suffice to meet demands for meat, crops, wood products and biofuels until at least 2040, without further conversion of natural ecosystems. As a result up to 14.3 Gt CO2 Eq could be mitigated. The fact that the country poised to undergo the largest expansion of agricultural production over the coming decades can do so without further conversion of natural habitats provokes the question whether the same can be true in other regional contexts and, ultimately, at the global scale.

The paper presents the results obtained in pHstat leaching test and assesses the influence of pH changes and occurring processes on the release of heavy metals (Cd, Ni, Crtotal, Pb, Cu and Zn) from metallurgical slag in a zinc smelter. Additionally, the analysis of the potential maximum amount of element available for leaching and releasing in the batch leaching test was carried out. All the results of the leaching tests were compared with the total content of heavy metals in the material. In order to evaluate the chemical forms of elements, a sequential extraction study was also carried out. On the basis of test results obtained in pHstat test, a strong dependence of heavy metals leaching on the pH was found. The highest concentrations of the analysed elements were observed in acidic environment. For most metals, except for lead, an increase in the pH of the solution caused a decrease in their concentration. Lead showed an upward trend of release under alkaline conditions. A sharp increase of copper leaching at pH 10.5 was also observed. Based on the results of the study, cadmium can be considered the most mobile element from metallurgical slag. Chromium indicated the lowest degree of release.

PURPOSE: The purpose of this study is to examine the association of anxiety with self-rated general health, satisfaction with life, stress and coping strategies of university students during the COVID-19 pandemic outbreak in Poland. PARTICIPANTS AND METHODS: = 2.60), participated in an online survey. The study was performed between 30 March and 30 April 2020, during the general coronavirus quarantine. Participants completed a standard psychological questionnaire, including General Anxiety Disorder (GAD-7), General Self-Rated Health (GSRH), Satisfaction With Life Scale (SWLS), Perceived Stress Scale (PSS), and Coping Inventory for Stressful Situations (CISS). RESULTS: The majority of students (65%) showed mild to severe GAD and a high level of perceived stress (56%). Those students who had the worst evaluated current GSRH, in comparison to the situation before the COVID-19 outbreak, also demonstrated higher levels of anxiety, perceived stress, and emotion-oriented coping styles. The study indicates that the variance of anxiety during the COVID-19 outbreak may be explained for about 60% by such variables, like high stress, low general self-rated health, female gender, and frequent use of both emotion-oriented and task-oriented coping styles. CONCLUSION: University students experience extremely high stress and anxiety during quarantine period and they need professional help to cope with COVID-19 pandemic. The results of this study may help prepare appropriate future intervention and effective prevention programs at universities.

Abstract In modern days, the conception of sustainability has progressively advanced and has begun receiving global interest. Thus, sustainability is an imperative idea in modern research. Considering the recent trend, this review paper presents a summary of the previously published research articles on minimum quantity lubrication (MQL) assisted machining. The requirement to stir towards sustainability motivated the researchers to revise the effects of substitute lubrication methods on the machining. Conventional lubri-cooling agents are still extensively employed when machining of engineering alloys, but the majority of the recent papers have depicted that the utilization of vegetable oil, nanofluids, and nanoplatelets in MQL system confers superior machining performances as compared to conventional lubrication technology. In actual, the definite principle of this manuscript is to re-examine modern advancements in the MQL technique and also explore the benefits of the vegetable oil and nanofluid as a lubricant. In brief, this paper is a testimony to the advancing capabilities of eco-friendly MQL technique which is a viable alternative to the flood lubrication technology, and the outcomes of this review work can be contemplated as a movement towards sustainable machining.

Part 1 of the paper presents a new numerical model of hygro-thermal and hydration phenomena in concrete at early ages and beyond. This is a solidification-type model where all changes of material properties are expressed as functions of hydration degree, and neither as maturity nor as equivalent hydration period as in maturity-type models. A mechanistic approach has been used to obtain the governing equations, by means of an averaging theory of Hassanizadeh and Gray, also called hybrid mixture theory. The developments start at the micro-scale and balance equations for phases and interfaces are introduced at this level and then averaged for obtaining macroscopic balance equations. Constitutive laws are directly introduced at macroscopic level. The final equations, mass (water species and dry air), energy and momentum balance equations, have been written in terms of the chosen primary variables: gas pressure, capillary pressure, temperature and displacements. An evolution equation for the internal variable, hydration degree, describes hydration rate as a function of chemical affinity, considering in addition to the existing models, an effect of the relative humidity on the process. The model takes into account full coupling between hygral, thermal and chemical phenomena, as well as changes of concrete properties caused by hydration process, i.e. porosity, density, permeability, and strength properties. Phase changes and chemical phenomena, as well as the related heat and mass sources are considered. Two examples showing possibilities of the model for analysis of autogenous self-heating and self-desiccation phenomena, as well as influence of the ambient relative humidity and the concrete element dimensions upon hygro-thermal performance and shrinkage of the elements, are presented and discussed. Copyright © 2006 John Wiley & Sons, Ltd.

Abstract For several industries, the traditional manufacturing processes are time-consuming and uneconomical due to the absence of the right tool to produce the products. In a couple of years, machine learning (ML) algorithms have become more prevalent in manufacturing to develop items and products with reduced labor cost, time, and effort. Digitalization with cutting-edge manufacturing methods and massive data availability have further boosted the necessity and interest in integrating ML and optimization techniques to enhance product quality. ML integrated manufacturing methods increase acceptance of new approaches, save time, energy, and resources, and avoid waste. ML integrated assembly processes help creating what is known as smart manufacturing, where technology automatically adjusts any errors in real-time to prevent any spillage. Though manufacturing sectors use different techniques and tools for computing, recent methods such as the ML and data mining techniques are instrumental in solving challenging industrial and research problems. Therefore, this paper discusses the current state of ML technique, focusing on modern manufacturing methods i.e., additive manufacturing. The various categories especially focus on design, processes and production control of additive manufacturing are described in the form of state of the art review.

Over the last few decades, the Brain-Computer Interfaces have been gradually making their way to the epicenter of scientific interest. Many scientists from all around the world have contributed to the state of the art in this scientific domain by developing numerous tools and methods for brain signal acquisition and processing. Such a spectacular progress would not be achievable without accompanying technological development to equip the researchers with the proper devices providing what is absolutely necessary for any kind of discovery as the core of every analysis: the data reflecting the brain activity. The common effort has resulted in pushing the whole domain to the point where the communication between a human being and the external world through BCI interfaces is no longer science fiction but nowadays reality. In this work we present the most relevant aspects of the BCIs and all the milestones that have been made over nearly 50-year history of this research domain. We mention people who were pioneers in this area as well as we highlight all the technological and methodological advances that have transformed something available and understandable by a very few into something that has a potential to be a breathtaking change for so many. Aiming to fully understand how the human brain works is a very ambitious goal and it will surely take time to succeed. However, even that fraction of what has already been determined is sufficient e.g., to allow impaired people to regain control on their lives and significantly improve its quality. The more is discovered in this domain, the more benefit for all of us this can potentially bring.

Studies suggest a positive association of spirituality and health behaviors with well-being (especially subjective well-being), but still the precise character of such relationships between all these constructs remains unknown. The present study aims to explore the relations between spirituality, health-related behaviors, and psychological well-being in the context of acquired education. A questionnaire survey was conducted among 595 students from six different universities, whose study programs either focused on the human body or the human mind and spirit. Path analysis and linear regression were used to model the relationship between the examined constructs. The results show that both spirituality and health-related behaviors are positively related to psychological well-being, and that the relationship with spirituality is also mediated by health-related behaviors. Only spirituality is associated with the type of acquired education, especially in the group of students whose studies focus on the human mind and spirit. Moreover, spirituality in this group seems to display a stronger relationship with psychological well-being. These findings may contribute to the better understanding of some significant determinants of psychological well-being. They carry important implications for the faculty members responsible for curriculum preparation to account for teaching contents related to the conduct of a healthy lifestyle and to spiritual development.

BACKGROUND: Virtual reality (VR) is being used more and more often as a therapeutic tool in psychology or psychiatry. In recent years, VR interventions appear more extensively also in disorders such as depression, anxiety and phobia. However, there has yet to be a comprehensive synthesis and critical review of the literature to identify future directions to advance the field in this area. OBJECTIVES: To broadly characterize the literature to date on the application of VR in psychiatric disorders by conducting a systematic review of reviews, describe the limitations of existing research, suggest avenues for future research to address gaps in the current literature and provide practical recommendations for incorporating VR into various treatments for psychiatric disorders. METHODS: PubMed and Web of Science databases were searched for reviews on VR use in psychiatric disorders (e.g. various pain perceptions, post-traumatic stress disorder, phobias, attention deficit hyperactivity disorder, psychosis, depression). The methodological quality of each literature review was assessed using AMSTAR. RESULTS: The original search identified 848 reviews, of which 70 were included in the systematic review of reviews. Broadly, the literature indicates that various VR interventions could be useful in different psychiatric disorders. CONCLUSION: This study provides evidence supporting the positive impact of VR therapy in psychiatric disorders. However, the impact is defined differently according to the studied area. Nevertheless, due to the continuous development of VR hardware and software, it is essential to conduct further research in the area of psychiatric disorders, especially as no review has concluded that VR does not work.

The student population has been highly vulnerable to the risk of mental health deterioration during the coronavirus disease (COVID-19) pandemic. This study aimed to reveal the prevalence and predictors of mental health among students in Poland, Slovenia, Czechia, Ukraine, Russia, Germany, Turkey, Israel, and Colombia in a socioeconomic context during the COVID-19 pandemic. The study was conducted among 2349 students (69% women) from May-July 2020. Data were collected by means of the Generalized Anxiety Disorder (GAD-7), Patient Health Questionnaire (PHQ-8), Perceived Stress Scale (PSS-10), Gender Inequality Index (GII), Standard & Poor's Global Ratings, the Oxford COVID-19 Government Response Tracker (OxCGRT), and a sociodemographic survey. Descriptive statistics and Bayesian multilevel skew-normal regression analyses were conducted. The prevalence of high stress, depression, and generalized anxiety symptoms in the total sample was 61.30%, 40.3%, and 30%, respectively. The multilevel Bayesian model showed that female sex was a credible predictor of PSS-10, GAD-7, and PHQ-8 scores. In addition, place of residence (town) and educational level (first-cycle studies) were risk factors for the PHQ-8. This study showed that mental health issues are alarming in the student population. Regular psychological support should be provided to students by universities.

In recent years, considerable progress has been made in semantic segmentation of images with favorable environments. However, the environmental perception of autonomous driving under adverse weather conditions is still very challenging. In particular, the low visibility at nighttime greatly affects driving safety. In this paper, we aim to explore image segmentation in low-light scenarios, thereby expanding the application range of autonomous vehicles. The segmentation algorithms for road scenes based on deep learning are highly dependent on the volume of images with pixel-level annotations. Considering the scarcity of labeled large-scale nighttime data, we performed synthetic data collection and data style transfer using images acquired in daytime based on the autonomous driving simulation platform and generative adversarial network, respectively. In addition, we also proposed a novel nighttime segmentation framework (SFNET-N) to effectively recognize objects in dark environments, aiming at the boundary blurring caused by low semantic contrast in low-illumination images. Specifically, the framework comprises a light enhancement network which introduces semantic information for the first time and a segmentation network with strong feature extraction capability. Extensive experiments with Dark Zurich-test and Nighttime Driving-test datasets show the effectiveness of our method compared with existing state-of-the art approaches, with 56.9% and 57.4% mIoU (mean of category-wise intersection-over-union) respectively. Finally, we also performed real-vehicle verification of the proposed models in road scenes of Zhenjiang city with poor lighting. The datasets are available at <uri xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">https://github.com/pupu-chenyanyan/semantic-segmentation-on-nightime</uri> .

Cryogenic machining is becoming a sustainable choice due to its extraordinary performance (such as non-toxic and environmentally friendly) superiority to other traditional coolants and lubricants to produce products with superior quality. This paper also critically reviews improvements in designing the cryogenic delivery setup used by researchers for machining low machinability materials like titanium alloys, nickel alloys, ferrous alloys, composites, and other difficult-to-cut materials. It also briefs the economic and sustainable perspective of this state-of-art technology. The aim is to maximize the usage of sustainable cryogenic and hybrid machining technologies in the global manufacturing industry by highlighting their advantages. An overview of in-house developed cryogenic and hybrid machining techniques is presented. Various challenges and future needs related to cryogenic and hybrid-machining techniques are also discussed in the articles. Although remarkable results are obtained with the available literature's delivery methods, there is still no consensus regarding the best cryogenic delivery methods for machining the aforementioned materials. In addition, further hybridization of cryogenic delivery techniques with near dry machining techniques such as minimum quantity lubrication (MQL), electrostatic-MQL (EMQL), and nanofluid based MQL (nMQL) can be beneficial for machinability improvements of difficult-to-machine materials.

This study focuses on the prediction of cutting forces during micro end milling using a novel approach that takes into account the chip thickness accumulation phenomenon. The proposed original force model considers the micro end milling kinematics, geometric errors of the machine tool–toolholder–mill system, elastic and plastic deformations of workpiece correlated with the minimum uncut chip thickness, and flexibility of the slender micro end mill. It also includes a novel analytical approach for the instantaneous area of cut. The chip thickness accumulation phenomenon can be manifested as chip thickness variations in the current tool rotation, resulting from material burnishing and elastic recovery in all previous tool rotations. The predicted forces consider the minimum uncut chip thickness value, which has been estimated directly from the micromilling process of AISI 1045 steel based on an original analytic–experimental approach that applies the identification of a stagnant point in the milling process. The results obtained show that the instantaneous and average micromilling forces determined using the proposed model have considerably better conformity with the experimental forces than those predicted using the commonly used rigid micro end milling model. Moreover, the non-linearity of the cutting forces as a function of feed per tooth is strongly affected by multiple cutting mechanism transitions observed during micromilling with uncut chip thicknesses close to the minimum uncut chip thickness value.

Poorly planned, large‐scale ecological restoration projects may displace agricultural activities and potentially lead to the clearance of native vegetation elsewhere, with associated impacts on biodiversity and ecosystem services. Yet few studies have considered these risks and the ways in which restoration can increase competition for land. Here, we address this issue by examining whether large‐scale restoration of the Brazilian Atlantic Forest could displace cattle production, as a result of land shortages. Although the risks of displacement are indeed high when reforestation is planned in areas with high cattle productivity, we discuss how these risks can be minimized through a combination of productivity increases, a regional restoration planning framework, and the prioritization of marginal agricultural land for restoration. We also consider how restoration can, in some circumstances, be made more economically sustainable by incorporating income‐generating activities such as exploitation of timber and non‐timber forest products, certification, and payments for ecosystem services.

The purpose of this study was to evaluate the role of family factors as predictors of posttraumatic stress disorder (PTSD) symptoms among adolescents, a substantial period of time after a natural disaster. It was hypothesized that a lack of parental support, family conflict, and overprotectiveness are all risk factors with regard to levels of PTSD symptoms. A group of 533 schoolchildren and high-school students was investigated 28 months after a huge flood, which was one of the most devastating disasters in Poland. The results of a hierarchical regression analysis indicate that the extent of traumatic exposure, parental support, family conflict, and overprotectiveness, all predicted levels of PTSD symptoms in the group investigated. Furthermore, parental overprotectiveness moderated the effect of trauma, thus augmenting the impact of stress experienced during the disaster on the level of PTSD symptoms. The findings suggest that excessive parental control and infantilization of children for a long time after a disaster are harmful for adolescents' health and could be an obstacle in the recovery process. The results highlight the importance of studying parental ways of coping in order to predict how adolescents cope with a traumatic event.

ABSTRACT This paper contains a review of energy‐based criteria of multiaxial fatigue. The criteria have been divided into three groups, depending on the kind of strain energy density per cycle which is assumed as a damage parameter. They are: (i) criteria based on elastic strain energy for high‐cycle fatigue; (ii) criteria based on plastic strain energy for low‐cycle fatigue; and (iii) criteria based on the sum of plastic and elastic strain energies for both low‐ and high‐cycle fatigue. The criteria which take into account strain energy density in the critical plane seem to be the most promising. In the energy approach to multiaxial fatigue there is an important unsolved problem, i.e. the evaluation of energy, especially plastic strain energy density, from closed stress–strain hysteresis loops under random loadings.

In Part I of this paper (Int. J. Numer. Meth. Eng., in print) a mechanistic model of hygro-thermo-chemical performance of concrete at early ages has been introduced. Additionally, as compared to the existing models (e.g. J. Eng. Mech. (ASCE) 1995; 121(7):785–794; 1999; 125(9):1018–1027), an effect of relative humidity on cement hydration rate and associated hygro-thermal phenomena have been taken into account. Here we deal with mechanical performance of concrete at early ages and beyond, and in particular, evolution of its strength properties (aging) and deformations (shrinkage and creep strains), described by using the effective stress concept. This allow us for explanation and modelling of phenomena known from experiments, like drying creep (e.g. Mathematical Modeling of Creep and Shrinkage of Concrete. Wiley: Chichester, 1988), or some additional strains, as compared to pure shrinkage, which appear during autogenous deformations of a maturing, sealed concrete sample (e.g. Cement Concrete Res. 2003; 33:223–232). Creep is described by means of the modified microprestress-solidification theory by Bazant et al. (J. Eng. Mech. (ASCE) 1997; 123(11):1188–1194; 1195–1201), with some modifications to take into account the effects of temperature (Comput. Struct. 2002; 80:1511–1521) and relative humidity (Int. J. Numer. Meth. Eng., in print; Proceedings of the 5th World Congress for Computational Mechanics (WCCM), Vienna, Austria, 7–12 July 2002), on concrete aging. Shrinkage strains are modelled by using the effective stress principle in the form introduced by Gray and Schrefler (Eur. J. Mech. A/Solids 2001; 20:521–538; Appl. Mech. Rev. (ASME) 2002; 55(4):351–388), giving a good agreement with experimental data also for lower values of relative humidity. Two numerical examples showing comparison of the results obtained by means of our model with some published experimental data are presented. The third one, concerning 2D axial symmetric case, proves numerical robustness of the developed software. All these examples demonstrate the possibilities of the model to analyse both autogenous deformations in maturing concrete and creep phenomena, including drying creep, in concrete elements of different age, sealed or drying, exposed to external load or without any load. Copyright © 2006 John Wiley & Sons, Ltd.

Along with the increasingly high level of digital media consumption, organizations’ expenditure on online promotional activities is constantly and dynamically growing. At the same time, together with the growing expenditures on digital promotion, it can be clearly seen that the effectiveness of activities carried out in the electronic space in its current form is decreasing. Therefore, in the new market situation, when the promotion of products and services has never been so difficult, organizations have started to look for other methods of influencing consumers. One of the most important trends is the use of the influencer marketing concept. In this context, the aim of this article is to analyze the role, place and significance of digital influencers in the overall functioning of the online promotional system, and the impact of the influencer marketing concept on its sustainable development. In order to implement it, a literature analysis was carried out on the origins of this phenomenon, and its scale, causes and impact on the functioning of the digital promotion system. After the completion of this stage of the research, a questionnaire survey was conducted on a group of individual Internet users in order to obtain primary data. The results of the research indicate that there is a great potential for activities involving digital influencers. This potential relates primarily to the effective transmission of information about a product or service, the impact on increased brand awareness, and the impact on the sales level of products and services offered by companies. The study also identified the most important threats that may affect the future development of the concept of influencer marketing.

OBJECTIVE: Physical activity can be an effective means of prevention and therapy of many psychosomatic disorders. It can also have a significant impact on the quality of life of older working-age people. The aim of the present study was to assess the relationships between quality of life and physical activity in older working-age people from Wrocław, Poland. MATERIALS AND METHODS: The study group comprised 1,013 people, including 565 women and 448 men, aged 55-64 years (59.1±2.9 years). The study took form of a questionnaire survey. The participants assessed their physical activity and quality of life using the International Physical Activity Questionnaire Short Version (IPAQ-SF) and the World Health Organization Quality of Life (WHOQOL-BREF), respectively. RESULTS: The highest mean indices of general quality of life, perceived health status, and quality of life in the physical, psychological, social, and environmental domains were shown by respondents whose intensity of physical activity was the highest. Moreover, the odds of high assessment of overall quality of life increased with respondents' higher levels of physical activity. CONCLUSION: Quality of life improvement programs should also involve increased physical activity components.

Research indicates that university and college students are at higher risk of experiencing mental health problems than other populations. This study aims to examine the relationship between Physical Activity (PA) and the mental health of Ukrainian university students during the Corona Virus Disease 2019 (COVID-19) pandemic lockdown. The conventional sample consisted of 1512 students from 11 Ukrainian universities, with a mean age of 20 years (M = 20.06, SD = 3.05) and 69% of whom were female. The cross-sectional online survey was disseminated through the most popular social media channels in Ukraine (i.e., Facebook, Viber, Telegram) and included the Generalized Anxiety Disorder (GAD-7) scale to measure anxiety and the Patient Health Questionnaire (PHQ-9) to assess depression. Data were collected from 14 May to 4 June 2020 during the COVID-19 pandemic outbreak in Ukraine. Among university students, 43% were engaged in PA ≥ 150 min weekly, 24% met the criteria of GAD, and 32% met the criteria of depression. More students were involved in PA before the COVID-19 outbreak than during the national lockdown. Students with anxiety and depression were almost two times less likely to engage in PA than their counterparts without mental health disorders. The inactive group had higher scores of anxiety and depression than the physically active group. The relationship of PA with anxiety and depression was statistically significant but weak during the COVID-19 pandemic.