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The utilization of hydrokinetic turbine technology is an innovative and sustainable method of generating electricity through the power of flowing water. The distinct advantage of this technology over traditional hydropower plants is its ability to operate without the need for the construction of dams or large water reservoirs, which can pose significant risks to local ecosystems and communities. Instead, hydrokinetic turbines can be directly installed in waterways, allowing for a more efficient and eco-friendly use of natural resources. This technology can provide clean, reliable electricity to millions of people globally, while also reducing greenhouse gas emissions and mitigating the effects of climate change. The present study presents two-dimensional computational fluid dynamics simulation of a cross-flow hydrokinetic turbine model. The simulation is performed by various Unsteady Reynolds-Averaged-NavierStokes models and then the results are compared to previous experimental and mathematical models. The flow field patterns and performance parameters of different models are presented and compared to compare the validity of different turbulence models available.

The utilization of hydrokinetic turbine technology represents an innovative and sustainable approach for generating electricity by harnessing the power of flowing water. Unlike traditional hydropower plants, hydrokinetic turbines offer several advantages as they do not require the construction of dams or large water reservoirs. This characteristic eliminates potential risks to local ecosystems and communities. By directly installing these turbines in waterways, the utilization of natural resources becomes more efficient and environmentally friendly. Consequently, this technology has the potential to provide clean and reliable electricity globally while also mitigating greenhouse gas emissions and addressing climate change. This research project focuses on conducting a comprehensive investigation through two-dimensional computational fluid dynamics simulations of a cross-flow hydrokinetic turbine model. By utilizing various Unsteady Reynolds-Averaged-Navier-Stokes models, the obtained results will be compared with previous experimental and CFD models. The flow field patterns will be analysed and compared to effectively illustrate the discrepancies and similarities among different turbulence models used.

Denna studie undersöker hur hybridarbetsmodellen påverkar anställdas arbetslivsbalans i Sverige efter Covid-19-pandemin. Det finns en brist på kvalitativa insikter i detta område, med särskilt fokus på deras personliga erfarenheter och upplevelser inom hybridarbetsmodellen. En kvalitativ studie genomfördes med hjälp av semi-strukturerade intervjuer med tio respondenter samt en tematisk analys med en induktiv ansats. Söktermer relaterade till COVID-19, hybridarbetsmodell, arbetslivsbalans, arbetar hemifrån, arbetar på kontoret, anställda och post-COVID-19 användes för att hitta relevanta studier. Resultaten visade att hybridarbetsmodellen förbättrar anställdas arbetslivsbalans genom att erbjuda flexibilitet, förbättrad arbetsmiljö, ekonomiska fördelar samt möjligheter för social interaktion och kommunikation. Hybridarbete minskar pendling och ger ökad flexibilitet, men introducerar även utmaningar som ergonomiska problem vid hemarbete och minskad social interaktion med kollegor. Utmaningar med att upprätthålla gränser mellan arbete och privatliv identifierades också. För att förklara förändringar i organisationer användes institutionell teori, medan resursbaserad teori användes för att förstå hur resurser kan bidra till en förbättrad arbetsmiljö. Studien bidrar genom att adressera hur arbetsgivare kan stödja anställdas balans mellan arbete och privatliv. Sammanfattningsvis visar studien att hybridarbetsmodellen, trots sina utmaningar, erbjuder betydande fördelar som kan bidra till förbättrad arbetslivsbalans och välbefinnande för anställda., Purpose: This study aims to increase understanding of the impact of the hybridwork model on employees´ work-life balance in the post-COVID-19 era, while also identifying the advantages and disadvantages associated with this workmodel. Design/Methodology/Approach: A qualitative empirical study was conducted using semi-structured interviews analysed through thematic analysis with an inductive approach. The search terms included phrases related to the hybrid workmodel, work-life balance, work from home, work from the office, employees, and post COVID-19. Thorough screening of titles, abstracts, and full texts was performed to select studies that met the inclusion criteria. Findings: The hybrid work model enhances employees´ work-life balance, encompassing various themes, including flexibility, the work environment, economic advantages, social interaction and communication, technological role, and challenges/boundaries between work and private life. Additionally, advantages and disadvantages were considered in this study. While these themes offer benefits such as flexible time and reduced absences from work and travel expenses, they also present disadvantages such as a lack of ergonomic furniture when working at home, weakened bonds between colleagues, concerns about maintaining a strong organizational culture, and potential decreases in collaboration and cohesiveness in team performance. Research Limitations/Implications: This study is limited to ten (10) employees working in white-collar jobs in Sweden, and further research should include bluecollar workers and increase the number of respondents to gain deeper insights and understanding into the impact of the hybrid work model on employees´ work-life balance. Furthermore, the study solely focuses on the perspective and experiences of employees, and it could be beneficial to consider both the viewpoints of employers and employees in future research. Originality/Value: This study contributes to existing organization

Denna studie undersöker hur hybridarbetsmodellen påverkar anställdas arbetslivsbalans i Sverige efter Covid-19-pandemin. Det finns en brist på kvalitativa insikter i detta område, med särskilt fokus på deras personliga erfarenheter och upplevelser inom hybridarbetsmodellen. En kvalitativ studie genomfördes med hjälp av semi-strukturerade intervjuer med tio respondenter samt en tematisk analys med en induktiv ansats. Söktermer relaterade till COVID-19, hybridarbetsmodell, arbetslivsbalans, arbetar hemifrån, arbetar på kontoret, anställda och post-COVID-19 användes för att hitta relevanta studier. Resultaten visade att hybridarbetsmodellen förbättrar anställdas arbetslivsbalans genom att erbjuda flexibilitet, förbättrad arbetsmiljö, ekonomiska fördelar samt möjligheter för social interaktion och kommunikation. Hybridarbete minskar pendling och ger ökad flexibilitet, men introducerar även utmaningar som ergonomiska problem vid hemarbete och minskad social interaktion med kollegor. Utmaningar med att upprätthålla gränser mellan arbete och privatliv identifierades också. För att förklara förändringar i organisationer användes institutionell teori, medan resursbaserad teori användes för att förstå hur resurser kan bidra till en förbättrad arbetsmiljö. Studien bidrar genom att adressera hur arbetsgivare kan stödja anställdas balans mellan arbete och privatliv. Sammanfattningsvis visar studien att hybridarbetsmodellen, trots sina utmaningar, erbjuder betydande fördelar som kan bidra till förbättrad arbetslivsbalans och välbefinnande för anställda., Purpose: This study aims to increase understanding of the impact of the hybridwork model on employees´ work-life balance in the post-COVID-19 era, while also identifying the advantages and disadvantages associated with this workmodel. Design/Methodology/Approach: A qualitative empirical study was conducted using semi-structured interviews analysed through thematic analysis with an inductive approach. The search terms included phrases related to the hybrid workmodel, work-life balance, work from home, work from the office, employees, and post COVID-19. Thorough screening of titles, abstracts, and full texts was performed to select studies that met the inclusion criteria. Findings: The hybrid work model enhances employees´ work-life balance, encompassing various themes, including flexibility, the work environment, economic advantages, social interaction and communication, technological role, and challenges/boundaries between work and private life. Additionally, advantages and disadvantages were considered in this study. While these themes offer benefits such as flexible time and reduced absences from work and travel expenses, they also present disadvantages such as a lack of ergonomic furniture when working at home, weakened bonds between colleagues, concerns about maintaining a strong organizational culture, and potential decreases in collaboration and cohesiveness in team performance. Research Limitations/Implications: This study is limited to ten (10) employees working in white-collar jobs in Sweden, and further research should include bluecollar workers and increase the number of respondents to gain deeper insights and understanding into the impact of the hybrid work model on employees´ work-life balance. Furthermore, the study solely focuses on the perspective and experiences of employees, and it could be beneficial to consider both the viewpoints of employers and employees in future research. Originality/Value: This study contributes to existing organization

The usage of superphosphate fertilizers, animal remedies and other material containing heavy metals (HMs) in agriculture and horticulture is a problematic issue resulting in the accumulation of HMs in the soil. The presence of these HMs in the soil leads to the induction of resistance of environmental bacteria to these heavy metals and may co-select for resistance against a broad range of antibiotics (Abs). This co-selection may increase the health risk for both humans and livestock because of resistance to the wide range of Abs. As well as direct health effects, an increase in Ab resistance may impose a significant burden on the livestock industry and primary production, leading to potential for immense social and financial losses. The current project was aimed to investigate the resistance of soil-borne bacteria sampled from selected regions of New Zealand. Genetic diversity of these bacteria and molecular aspects of horizontal transfer of HM and Ab resistance genes to other bacterial hosts was also investigated. Soil samples with a different history of usage, including pastoral and arable with high levels of HMs (e.g. cadmium (Cd) and zinc (Zn)) were collected from the Waikato region (WR), as well as soil from an area of native bush (background) as control. Waikato Region (WR) is one of the regions in New Zealand with high levels of HMs in soil, due to the regular use of HM-containing superphosphate fertilizers and animal remedies. Belmont Regional Park (BRP) airstrip soil was used as a novel site to explore bacterial communities’ resistance to HMs, and any co-selected Ab resistance. A comprehensive investigation was performed to simulate the soil environment contaminated with various levels of HMs to interrogate induced resistance to HMs and Abs in soil bacterial communities using microcosms with 6 weeks and 6 months incubation. The experiments carried out to investigate soil bacterial resistance to HMs and Abs were divided into two different categories, includi

In this study, a new approach based on adaptive dynamic programming (ADP) is proposed to control permanent magnet synchronous motors (PMSMs). The objective of this paper is to control the torque and consequently the speed of a PMSM when an unknown load torque is applied to it. The proposed controller achieves a fast transient response, low ripples and small steady-state error. The control algorithm uses two neural networks, called critic and actor. The former is utilized to evaluate the cost and the latter is used to generate control signals. The training is done once offline and the calculated optimal weights of actor network are used in online control to achieve fast and accurate torque control of PMSMs. This algorithm is compared with field oriented control (FOC) and direct torque control based on space vector modulation (DTC-SVM). Simulations and experimental results show that the proposed algorithm provides desirable results under both accurate and uncertain modeled dynamics. Although the performance of FOC method is comparable with ADP under nominal conditions, the torque and speed response of ADP is better than FOC under realistic scenarios, that is, when parameter uncertainties exist.

Adaptive optimal control using value iteration initiated from a stabilizing control policy is theoretically analyzed in terms of stability of the system during the learning stage without ignoring the effects of approximation errors. This analysis includes the system operated using any single/constant resulting control policy and also using an evolving/time-varying control policy. A feature of the presented results is providing estimations of the \textit{region of attraction} so that if the initial condition is within the region, the whole trajectory will remain inside it and hence, the function approximation results remain valid., Comment: A part of this paper is based on preliminary results presented in arXiv:1412.5675

Mild anemia and leukopenia are the most common hematologic problems of acute brucellosis. Mild thrombocytopenia also occurs, but severe cases are uncommon. Thrombocytopenia occurs because of bone marrow suppression, hypersplenisem, hemophagocytosis, and immunologic destruction of the cells or disseminated intravascular coagulation. In endemic areas, hemorrhagic fevers, hematologic malignancies, as well as idiopathic thrombocytopenic purpura should be considered as differential diagnoses for complicated brucellosis. Thrombocytopenia and bleeding can be improved with antibiotic and hematologic supportive therapy whereas in severe cases corticosteroid therapy or splenectomy might be necessary.

Mild anemia and leukopenia are the most common hematologic problems of acute brucellosis. Mild thrombocytopenia also occurs, but severe cases are uncommon. Thrombocytopenia occurs because of bone marrow suppression, hypersplenisem, hemophagocytosis, and immunologic destruction of the cells or disseminated intravascular coagulation. In endemic areas, hemorrhagic fevers, hematologic malignancies, as well as idiopathic thrombocytopenic purpura should be considered as differential diagnoses for complicated brucellosis. Thrombocytopenia and bleeding can be improved with antibiotic and hematologic supportive therapy whereas in severe cases corticosteroid therapy or splenectomy might be necessary.

Adaptive optimal control of nonlinear dynamic systems with deterministic and known dynamics under a known undiscounted infinite-horizon cost function is investigated. Policy iteration scheme initiated using a stabilizing initial control is analyzed in solving the problem. The convergence of the iterations and the optimality of the limit functions, which follows from the established uniqueness of the solution to the Bellman equation, are the main results of this study. Furthermore, a theoretical comparison between the speed of convergence of policy iteration versus value iteration is presented. Finally, the convergence results are extended to the case of multi-step look-ahead policy iteration.

Adaptive optimal control using value iteration (VI) initiated from a stabilizing policy is theoretically analyzed in various aspects including the continuity of the result, the stability of the system operated using any single/constant resulting control policy, the stability of the system operated using the evolving/time-varying control policy, the convergence of the algorithm, and the optimality of the limit function. Afterwards, the effect of presence of approximation errors in the involved function approximation processes is incorporated and another set of results for boundedness of the approximate VI as well as stability of the system operated under the results for both cases of applying a single policy or an evolving policy are derived. A feature of the presented results is providing estimations of the region of attraction so that if the initial condition is within the region, the whole trajectory will remain inside it and hence, the function approximation results will be reliable., Comment: In this revision the proof of Lemma 5 is updated. Initial submission date: 12/17/2014. (This study has overlaps on Theorem 6 and Lemma 5 with another work of the author available at arXiv:1412.6095)

The problem of resource allocation of nonlinear networked control systems is investigated, where, unlike the well discussed case of triggering for stability, the objective is optimal triggering. An approximate dynamic programming approach is developed for solving problems with fixed final times initially and then it is extended to infinite horizon problems. Different cases including Zero-Order-Hold, Generalized Zero-Order-Hold, and stochastic networks are investigated. Afterwards, the developments are extended to the case of problems with unknown dynamics and a model-free scheme is presented for learning the (approximate) optimal solution. After detailed analyses of convergence, optimality, and stability of the results, the performance of the method is demonstrated through different numerical examples.

This study is aimed at answering the famous question of how the approximation errors at each iteration of Approximate Dynamic Programming (ADP) affect the quality of the final results considering the fact that errors at each iteration affect the next iteration. To this goal, convergence of Value Iteration scheme of ADP for deterministic nonlinear optimal control problems with undiscounted cost functions is investigated while considering the errors existing in approximating respective functions. The boundedness of the results around the optimal solution is obtained based on quantities which are known in a general optimal control problem and assumptions which are verifiable. Moreover, since the presence of the approximation errors leads to the deviation of the results from optimality, sufficient conditions for stability of the system operated by the result obtained after a finite number of value iterations, along with an estimation of its region of attraction, are derived in terms of a calculable upper bound of the control approximation error. Finally, the process of implementation of the method on an orbital maneuver problem is investigated through which the assumptions made in the theoretical developments are verified and the sufficient conditions are applied for guaranteeing stability and near optimality., Comment: This study is the counterpart of another work of the author (arXiv:1412.5675) which was for value iterations with initial stabilizing guess (with overlaps on Theorem 1 and Lemma 1). As for the revision on this work, some steps of proofs are updated and an explanation about the approximation error is included. Initial submission date: 12/18/2014

The problem of optimal switching between nonlinear autonomous subsystems is investigated in this study where the objective is not only bringing the states to close to the desired point, but also adjusting the switching pattern, in the sense of penalizing switching occurrences and assigning different preferences to utilization of different modes. The mode sequence is unspecified and a switching cost term is used in the cost function for penalizing each switching. It is shown that once a switching cost is incorporated, the optimal cost-to-go function depends on the already active subsystem, i.e., the subsystem which was engaged in the previous time step. Afterwards, an approximate dynamic programming based method is developed which provides an approximation of the optimal solution to the problem in a feedback form and for different initial conditions. Finally, the performance of the method is analyzed through numerical examples.