Effect of Long-Term Zinc Pollution on Soil Microbial Community Resistance to Repeated Contamination

The aim of the study was to compare the effects of stress (contamination trials) on the microorganisms in zinc-polluted soil (5,018 mg Zn kg−1 soil dry weight) and unpolluted soil (141 mg Zn kg−1 soil dw), measured as soil respiration rate. In the laboratory, soils were subjected to copper contamination (0, 500, 1,500 and 4,500 mg kg−1 soil dw), and then a bactericide (oxytetracycline) combined with a fungicide (captan) along with glucose (10 mg g−1 soil dw each) were added. There was a highly significant effect of soil type, copper treatment and oxytetracycline/captan treatment. The initial respiration rate of chronically zinc-polluted soil was higher than that of unpolluted soil, but in the copper treatment it showed a greater decline. Microorganisms in copper-treated soil were more susceptible to oxytetracycline/captan contamination. After the successive soil contamination trials the decline of soil respiration was greater in zinc-polluted soil than in unpolluted soil

Minimum Information about T Regulatory Cells: A Step toward Reproducibility and Standardization.

Cellular therapies with CD4+ T regulatory cells (Tregs) hold promise of efficacious treatment for the variety of autoimmune and allergic diseases as well as posttransplant complications. Nevertheless, current manufacturing of Tregs as a cellular medicinal product varies between different laboratories, which in turn hampers precise comparisons of the results between the studies performed. While the number of clinical trials testing Tregs is already substantial, it seems to be crucial to provide some standardized characteristics of Treg products in order to minimize the problem. We have previously developed reporting guidelines called minimum information about tolerogenic antigen-presenting cells, which allows the comparison between different preparations of tolerance-inducing antigen-presenting cells. Having this experience, here we describe another minimum information about Tregs (MITREG). It is important to note that MITREG does not dictate how investigators should generate or characterize Tregs, but it does require investigators to report their Treg data in a consistent and transparent manner. We hope this will, therefore, be a useful tool facilitating standardized reporting on the manufacturing of Tregs, either for research purposes or for clinical application. This way MITREG might also be an important step toward more standardized and reproducible testing of the Tregs preparations in clinical applications

Finite element analysis of thermal stresses in a pad-disc brake system (a review)

Rapid temperature change in components of the sliding systems induces thermal stresses due to thermal expansion. This effect is particularly evident in disc brakes working under high thermal loads. This paper deals with the finite element modelling of frictional heating process in disc brakes and clutches to study the temperature and stress distributions during operation

Convective Cooling of a Disc Brake During Single Braking

This study is primarily focused on the investigation of an impact of heat transfer coefficient on heat dissipation from the solid disc using the finite element method (FEM). The analysis was carried out within four individual cases of braking of the passenger vehicle simulating mountain descent with different velocities and the following release periods, where the convective terms of cooling were dependent on the angular velocity of the disc. For the purpose of confronting contrasting conditions of the braking action, apart from heating region, the whole surface of the disc was insulated. The process was performed under the operation conditions of a real front disc brake, whose dimensions and thermophysical properties of materials were adopted and applied to the FE model. It was concluded that the influence of cooling of the exposed surfaces of the disc during relatively short braking is insignificant. However the period after brake release results in considerable decrease in temperature of the disc

Mechanical and electrical impedance matching in a piezoelectric beam for Energy Harvesting

A piezoelectric beam is one of transducers for energy harvesting. It provides easy implementation and good performance in changing mechanical stress into electric voltage. In order to maximize output power, it is important to provide mechanical and electrical impedance matching. In the paper the authors proposed a methodology which allows to find values of lumped elements in an electromechanical model after completing appropriate measurements. Due to linear equations, it is possible to model a beam in both mechanical and electrical ways, and match the best load depending of frequency. The proposed model of a piezoelectric cantilever shows a potential use of these devices in micro scale as a cantilever which is a part of a silicon structure. Moreover, in the paper, the authors discuss mechanical aspects of using a weight as the way to tune the piezoelectric beam to a specific frequency. The electrical aspect of matching the source impedance with load, which is based on an electrical model of a piezoelectric transducer, is also presented. In the paper a mathematical model was verified by an experiment in which a laboratory stand equipped with a vibration generator, a piezoelectric energy harvester and acceleration sensors was used

Zawartość form potasu w glebie płowej w warunkach zróżnicowanego nawożenia azotowego i nawadniania

The present study shows the content of different potassium forms found in lessive soil and was based on a 12-year long field experiment. In this work the following conditions were used: differential N fertilization and differential irrigation (fields were either left with no water or irrigated). The soil samples were collected from three different depths that matched genotypes of lessive soil: 0-30, 30-60 and 60-90 cm. We have mapped the following potassium forms: active (K-CaCl2), bioavailable Enger-Riehm (K-Dl), exchangeable (K-CH3COONH4), fixed (K-HCl) and non-exchangeable (K-HNO3). We observed that with the increased concentrations of N fertilization, there was a reduction in the content of potassium forms, in particular when fields were irrigated. Moreover, in majority of cases, there were fewer potassium forms on irrigated fields (in particular on 0-30 cm).W pracy przedstawiono wyniki badań dotyczące ilości form potasu w glebie płowej. Badania prowadzono na próbkach glebowych pobranych z długoletniego doświadczenia polowego (dwunastoletniego) założonego na glebie płowej. Czynnikami doświadczenia były: zróżnicowane nawożenie azotowe oraz reżim wodny (poletka deszczowane i nie deszczowane). Próbki do badań pobrano z trzech głębokości 0-30, 30-60 i 60-90 cm, które odpowiadały trzem kolejnym poziomom genetycznym gleby płowej. W pracy oznaczono następujące formy potasu: aktywny (K-CaCl2), przyswajalny Egnera-Riehma (K-Dl), wymienny (K-CH3COONH4), uwsteczniony (K-HCl) oraz zapasowy (K-HNO3). Zastosowane w doświadczeniu czynniki miały w wielu przypadkach istotny wpływ na zróżnicowanie ilości analizowanych form potasu. Wraz ze wzrostem zastosowanej dawki nawożenia azotowego malała zawartość analizowanych form potasu, szczególnie na obiektach deszczowanych. Na obiektach deszczowanych zaobserwowano także w większości przypadków mniejszą zawartość analizowanych form potasu szczególnie w poziomie 0-30 cm

Ekologizacja gospodarstw rolniczych na podstawie norm emisji spalin silnikowych maszyn rolniczych użytkowanych na terenie powiatu krotoszyńskiego

The interest in organic farming, due to the increasing demand for food free of residues of plant protection chemicals, mineral fertilizers and heavy metals, is getting bigger and bigger. However, it should be remembered that in addition to avoiding the use of chemical methods for plant protection and care, as well as growth stimulators and antibiotics in animal breeding, it is also important to reduce the negative effects on the natural environment. Therefore, the use of energyefficient machines, which additionally do not pollute the environment excessively, is one of the elements of organic farming. In recent years, the issue of reducing nitrogen oxides and particulate solids emitted by engines in agricultural tractors is considered more and more rigorously. The aim of this study was to analyze motor agricultural machines used in farms in Krotoszyn County in terms of exhaust emission standards. The researches covered 30 randomly selected farms, in which 12 agricultural tractors were used. Analysis of the results showed that the majority of tractors used in agriculture in Krotoszyn County do not meet any exhaust emission standards and that these machines are obsolete.Zainteresowanie rolnictwem ekologicznym, dzięki coraz większemu popytowi na żywność wolną od pozostałości środków ochrony roślin, nawozów mineralnych i metali ciężkich jest coraz większe. Należy jednak pamiętać, ze poza unikaniem stosowania chemicznych metod ochrony i pielęgnacji roślin oraz stymulatorów wzrostu i antybiotyków przy chowie zwierząt, ważne jest również ograniczenie wywierania negatywnych skutków na środowisko naturalne. Dlatego jednym z elementów rolnictwa ekologicznego jest stosowanie energooszczędnych maszyn, które dodatkowo nie zanieczyszczają nadmiernie środowiska. W ostatnich latach coraz bardziej rygorystycznie podchodzi się do kwestii ograniczania tlenków azotu i cząstek stałych emitowanych przez silniki w ciągnikach rolniczych. Celem pracy była analiza silnikowych maszyn rolniczych użytkowanych w gospodarstwach rolnych powiatu krotoszyńskiego pod kątem norm emisji spalin. Badaniami objęto losowo wybranych 30 gospodarstw rolnych, w których użytkuje się 112 ciągników rolniczych. Analiza wyników wykazała, że większość ciągników w badanych gospodarstwach nie spełnia żadnych norm emisji spalin i są to maszyny przestarzałe