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  • Author: Aleksandra Rak x
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Abstract

Rational and efficient use of thermal energy in recent years has resulted in significant changes in the heating system as well as technological progress. In order to design a heating system properly and exploit it correctly, an in-depth understanding of the hydraulic issues is necessary. Application of automatic control system in various sectors of heating network has resulted in a more dynamic and efficient work of the whole system. For proper operation of a thermal system it is also necessary to compile a correct heat balance and a regulation graph that allows to determine the optimal mass and parameters of heat medium. The article discusses the problems of supplying heat process, types of thermal systems and selected problems of hydraulic issues that occur in the heating networks.

Abstract

In recent years heating in Poland has been transformed as a result of the priorities of the country's energy policy implemented within the European Union. The increase in energy security, the development of renewable energy sources and the fulfilment of legal and environmental requirements are very important. Exploitation of district heating systems should ensure reliable and safe heat supplies for industrial and municipal customers with high energy efficiency and reduction of environmental impact. The article discusses the conditions and directions of centralized heating systems development as well as technical and economic issues, which are important for the security of heat supply. The Author describes selected technological innovations used in the technical infrastructure for heat transfer and modern IT systems which are improving the management of heating systems. The article includes the results of simulation research with use of IT tools showing the impact of selected innovations on the improvement of network operation conditions. Directions of modernization of heating systems in the aspect of increasing energy efficiency and security of heat supply have also been indicted here.

Abstract

Billions of people in the world are at risk of getting unsafe food. There is an urgent need to improve efficiency and effectiveness of food supply chains. The global population is expected to reach at least 9 billion by the year 2050, requiring up to 70% more food than nowadays and demanding food production and distribution to become much more sustainable. Today, food safety is a worldwide concern due to a number of food safety scandals. As supply chains become more globalized and complex, the ability to track and trace products from fork to farm becomes more difficult but remains equally important. Good traceability may minimize the production and distribution of unsafe or poor quality products. It allows targeting the product affected by a food safety problem, minimizing disruption to trade and any potential public health risks. The objective of this paper is therefore to conduct a comprehensive analysis of traceability methods and technologies in food supply chains.

Abstract

The aim of the study was to determine the levels of the vascular endothelial growth factor (VEGF) in the serum of dogs suffering from splenic malignant tumours, prior to splenectomy, as well as three and six months after the surgery. Tumours and blood samples were collected from 10 dogs of various breeds, aged between 7 and 13 years, and from 10 control animals. Tumour sections were fixed in 10% buffered formalin for 24 h. The type of tumour was determined according to the WHO classification. Blood samples were centrifuged and the obtained sera were subjected to immunoenzymatic assays to determine the VEGF levels. The median of VEGF levels in the serum of dogs suffering from splenic malignant tumours was 37.85 pg/mL (15.40-107.18 pg/mL). The highest values were observed in dogs with confirmed metastases (107.18 pg/mL and 65.43 pg/mL). The VEGF values in control group were between 0.1 pg/mL and 13.04 pg/mL. A comparative analysis of the VEGF levels against the animals' survival time indicated that VEGF overexpression may serve as a prognostic factor in cases of malignant tumours of the spleen.

Abstract

The aim of the study was to demonstrate the orthodontic treatment of malocclusions in dogs, a condition which can lead to cranio-mandibular and functional disorders of the stomatognathic system. The treatment involved the use of maxillofacialorthopaedic appliances, which type depended on the type of disorder and the degree of malocclusion. The applied treatment induced changes in the alveolar bone. Throughout the process of the treatment a great attention was paid to regular brushing off the orthodontic appliance using antiseptics for prophylactic prevention of inflammation of gingival tissue and the palate caused by food getting stuck in the spaces between the teeth.