Steel ceramic composite anodes based on recycled MgO–C lining bricks for applications in cryolite/aluminum melts

Novel manufacturing route for composite inert anodes containing 60:40 of 316 L stainless steel and MgO powder obtained from recycled MgO–C brick material has been developed and evaluated. After burnout of residual carbon from the recycled MgO–C powder, MgO and steel were granulated and pre-sintered in order to generate agglomerates of composite material acting as coarse grains within the composite material, and thus lowering the sintering-related shrinkage. The pre-sintered granules were mixed with raw steel and MgO powder in order to achieve a high particle packing and subsequently cold isostatically pressed in the form of electrodes. All manufactured anode samples were subjected to sintering at 1350 °C and pre-oxidation at different temperatures – 800 °C, 900 °C, and 1000 °C. Afterwards, mechanical and electrical properties of the manufactured electrodes were characterized. The results show that upcycling of the MgO–C material enables manufacturing of sophisticated electrode products, which can be applied in the aluminum industry

On the constraints violation in forward dynamics of multibody systems

It is known that the dynamic equations of motion for constrained mechanical multibody systems are frequently formulated using the Newton-Euler’s approach, which is augmented with the acceleration constraint equations. This formulation results in the establishment of a mixed set of partial differential and algebraic equations, which are solved in order to predict the dynamic behavior of general multibody systems. The classical resolution of the equations of motion is highly prone to constraints violation because the position and velocity constraint equations are not fulfilled. In this work, a general and comprehensive methodology to eliminate the constraints violation at the position and velocity levels is offered. The basic idea of the described approach is to add corrective terms to the position and velocity vectors with the intent to satisfy the corresponding kinematic constraint equations. These corrective terms are evaluated as function of the Moore-Penrose generalized inverse of the Jacobian matrix and of the kinematic constraint equations. The described methodology is embedded in the standard method to solve the equations of motion based on the technique of Lagrange multipliers. Finally, the effectiveness of the described methodology is demonstrated through the dynamic modeling and simulation of different planar and spatial multibody systems. The outcomes in terms of constraints violation at the position and velocity levels, conservation of the total energy and computational efficiency are analyzed and compared with those obtained with the standard Lagrange multipliers method, the Baumgarte stabilization method, the augmented Lagrangian formulation, the index-1 augmented Lagrangian and the coordinate partitioning method.The first author expresses his gratitude to the Portuguese Foundation for Science and Technology through the PhD grant (PD/BD/114154/2016). This work has been supported by the Portuguese Foundation for Science and Technology with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941.info:eu-repo/semantics/publishedVersio

Body composition and Hashimoto disease

Background. Body weight or BMI do not provide any information about the content of muscle tissue, water content, body fat and its distribution in the body. Thyroid dysfunction is associated with a change in body weight, but also its composition regardless of physical activity. Objective. The aim of the study was to compare the body composition of female patients diagnosed with Hashimoto's disease (HD) and the body composition of healthy women who have never been treated before due to thyroid diseases. Materials and methods. The study involved 47 women diagnosed with Hashimoto disease (HD) and 65 women declaring good health. Body mass and height and body composition analysis using bioelectrical impedance analysis were performed using the TANITA multi-frequency segmental body composition analyzer. Variables having a distribution similar to the normal distribution were analyzed by the analysis of variance (ANOVA), otherwise the Kruskal-Wallis test was used. Results. Women with Hashimoto disease were characterized by significantly higher values of body weight, and thus BMI index, than healthy women (respectively 73.64 kg vs. 64.36 kg, p <0.0001; 27.65 kg/m2 vs. 23.95 kg/m2, p <0.001).The problem of excess body fat in the body statistically significantly more often affected women with Hashimoto disease than healthy women (44.7% vs. 13.8%, p <0.001). Conclusions. The results regarding the weight and composition of the patients treated for thyroid disease indicate the need for further in-depth analyses. Even small abnormalities of the thyroid function in the range of reference values may result in the development of many adverse changes in the body

Assessment of caffeine intake with food by Polish females and males

Background. Caffeine is the most widespread psychoactive substance in the world. With long-term consumption of caffeinated beverages, there is a high probability of overtaking on caffeine. Objective. The aim of the study was to estimate the consumption of caffeine in the daily caffeine intake of Polish consumers, determine the caffeinated products in the intake of this substance. Materials and methods. The survey was completed by 433 respondents living in Poland. The research tool was the electronic questionnaire, which consisted of: a) questions about personal data and measurement anthropometric and the level of physical activity and smoking; b) questions regarding the portion size and frequency of consumption of coffee, tea, cocoa, chocolate, energy drinks and colacarbonated beverages. Results. The main sources of caffeine in the respondents' diet include: coffee (Me 43.64 mg/d) and tea (Me 37.60 mg/d). Approximately 20% of respondents exceeded the threshold of daily caffeine intake (safety level for children and adolescents up to 3 mg/kg b.w, for adults up to 5.7 mg/kg b.w), considered safe. Conclusions. Respondents who have crossed the safe dose of caffeine intake, should limit the consumption of products being its main source (coffee

Uogólniony model magnetycznej pętli histerezy Jilesa - Athertona

The paper presents a generalization of the Jiles-Atherton (J-A) model. The main goal of this work is to take into account all phenomena, such as conducting media, which result in a change in the shape of the magnetic hysteresis with frequency. For this purpose a class of models of Chua is recalled. The authors pointed the model, named J-A-C able to reproduce any phenomena. The authors compared the model J-A-C with other extensions of the J-A model, obtaining the results more consistent with measurements than these models.W artykule przedstawiono uogólniony model pętli histerezy magnetycznej Jilesa-Athertona (J-A). Celem pracy było przygotowanie modelu fenomenologicznego obejmującego wszystkie zjawiska zachodzące w materiale, takie jak np. prądy wirowe, które prowadzą do zmiany kształtu pętli histerezy wraz ze zmianą częstotliwości. Aby osiągnąć ten cel odwołano się do koncepcji modelu zaproponowanego przez L.O. Chua. W istocie jest to cała klasa modeli ze zmienną szerokością pętli histerezy. Modele te są czysto fenomenologiczne i mogą być wykorzystane w celu opisania wszystkich zjawisk, bez konieczności odnoszenia się do ich fizycznych podstaw. Autorzy opracowali model nazwany J-A-C, który jest bardzo podobny do pewnego modelu z klasy modeli Chuy, dziedzicząc dzięki temu wszystkie jego właściwości. W szczególności model zawiera wszystkie parametry modelu J-A, ponadto może obejmować parametry opisujące zmiany kształtu histerezy. Stwierdzono, że parametry przygotowane dla modelu J-A, a wykorzystane w modelu J-A-C pozwalają na uzyskanie wyników równie dokładnych jak w przypadku modelu J A. Autorzy artykułu porównali wyniki osiągnięte przy pomocy modelu J-A-C z innymi rozszerzeniami modelu J-A, które uwzględniają prądy wirowe w materiale magnetycznym. Model J-A-C lepiej oddaje wyniki pomiarów niż te modele. Niewątpliwą zaletą modelu J-A-C jest fakt, że rozszerza podstawowy model J-A pozwalając na odzwierciedlenie całej klasy zjawisk związanych z dyssypacją energii w materiale magnetycznym. Obecnie głównym przedmiotem badań jest uniwersalna metoda, która pozwoliłaby na wyznaczanie parametrów modelu niewystępujących w modelu J-A

Influence of National Program of Forested Areas Increase on the spatial planning system in Poland

Opracowanie Krajowego Programu Zwiększania Lesistości spowodowało konieczność dostosowania dokumentów prawnych (ustaw) z zakresu leśnictwa i planowania przestrzennego odnośnie procedur związanych z przeznaczaniem gruntów do zalesienia. W pracy opisano etapy KPZL, instrumenty prawne dotyczące procedury zwiększania lesistości, a także szczegółowo przeanalizowano regulacje i procedury prawne związane z zalesianiem gruntów. Wskazano niespójności przepisów, dwutorowość działań i ich konsekwencje.Presented study tested influence of National Program of Forested Areas Increase (KPZL) on the spatial planning system in Poland, in order to local (community) level which, regarding to system changing and intensive socio-economic development, became a basic spatial planning system unit. In the paper there are described the stages of KPZL and legal instruments connected to the topic. Deep investigation of law procedures and regulations related to grounds reforestation was carried out. As a result of presented work, failures in law rules were found, and problems caused by this state of affairs