Effect of deforestation on stream and spring water chemistry in Malinowski and Czyrna catchments in Beskid Alaski Mts.

Dieback of Norway spruce (Picea abies (L.) H. Karst) which has been observed in the Western Carpathians is of interest to scientists from many disciplines.. The aim of this study was to determine the impact of deforestation on water chemical composition in mountainous streams and springs. The research was carried out in 2004 and 2013 in two catchments of the Skrzyczne massif in the Silesian Beskid Mountains. Field studies included measurements of water pH and conductivity. Under laboratory conditions, there were determined concentrations: Na+, K+, Ca2+, Mg2+, NH4+, Cl-, NO3-, SO4 2 in each water sample. The results of physical and chemical analyses of water collected within the Malinowski catchment (covered mainly with spruce stands) and on northern slopes of the Skrzyczne massif – within the Czyrna catchment (covered mainly with beech stands), showed higher contents of base cations when compared to deforested areas. The highest concentrations of the ions analysed were recorded within the Czyrna catchment. Such phenomena should be taken into consideration during forest reconstruction after spruce dieback

Energy costs savings by use of micro - CHP units in domestic households

Prices of thermal and electric energy delivered to households are constantly increasing, and it will probably not change over the next few years. Due to this fact, people had been forced to find different ways to reduce costs of buying energy. The paper contains description of the most popular systems which are already in use from many years and some innovative systems which are implemented now, or which may be probably installed in nearly future – for example: internal combustion engines, Stirling engines, proton exchange membrane fuel cells, gas turbines, engines with Rankine cycle, etc. Each of mentioned above appliances is necessary to create CHP system which advantages and disadvantages are also described. In this publication, the most promising units have been compared to show their performance, flexibility, profitability and range of using ability. In this paper, approximate money and energy savings that may occur by using modern solutions compared to traditional systems are also shown. As always, during design and development of this kind of devices, there are a lot of problems related to various issues. Main problems and potential solutions have been also presented in this article. In summary further research, directions are suggested due to improve performance of this kind of systems

Opportunities of exhaust heat recovery and conversion to electricity

The maximum efficiency of the conventional spark ignition engine is 33%, in the case of diesel engines is 42%. The conclusion is that the energy contained in the fuel and "released" in the combustion process is converted into mechanical work only in a small degree. The rest of the energy is unfortunately lost by heat, friction, or used to drive the engine accessories. It should also be noted that these values are peak efficiency, which is achieved only when the engine works in optimal parameters. At most used parameters engines reach efficiency on the level of 10% to 25%. In modern cars with a hybrid powertrain are solutions that can improve the efficiency of conventional internal combustion engines. It is worth to notice that there are few ways to improve the efficiency of a reciprocating engine. The main technological trends on which research is underway are knock ignition and heat recovery from the exhaust. More development seems to be the second solution, because it can be used to design new engines such as the replacement of the alternator on the generator of electricity from exhaust heat. Besides, it will be possible to adapt these systems to in-use units, which improve the energy balance of riding vehicles. In article, you will find information of literature analysis for exhaust heat recovery and conversion to electricity solutions, computerized exhaust modification with flow calculations, real modification, test bench creation, researches and scores, analysis

The impact of the energy state of the surface of friction pairs on the friction and wear in internal combustion engines

The elements creating a friction pairs are described to be very difficult in terms of defining all optimal parameters in an unequivocal way. The research on stability of friction pairs is focused on the surface and the top layer of surface in the parts concerned. The main goal is to find new design solutions and materials, thereby achieving one million kilometers of mileage to main repair in the case of internal combustion engines. The biggest structural difficulties are noticeable in friction pairs where it can be observed sliding and returning motion, which is also connected with sealing function. A typical example of such pair is piston ring – cylinder sleeve in piston – rings - cylinder unit in an internal combustion engine. Engineers are currently seeking an additional factor, which would enable gaining the reduction of tangential force by reducing the friction coefficient in elements of friction pair during operations. The surface free energy may be such factor - it results from molecular structure and nature of the bonds between the molecules present in the material. Components of surface free energy determine the tribological properties of the material, which is reflected in the stability of the units. Energy state of the surface, which is connected with chemistry and characteristics in the material, is the first step to consider about the impact on wearing in internal combustion engine. This is the main topic of this article

Various designs of the two-stroke engine heads with the valve flushed system

The two-stroke engines have never acquired the popularity of the four-stroke engines due to their inherent performance limitations. The tasks of many engineering teams were to find the basic causes, which resulted in the inferior performance of these engines. Today’s task is to build a two-stroke engine whose performance could match that of a four-stroke engine in areas of common use. The most typical performance problems of a two-stroke engine are high petrol consumption caused by low efficiency, toxic by-products of combustion being emitted into the atmosphere (caused by oil present in the petrol), and uneven and loud engine noise. The greatest challenge is to achieve a good chamber purge during one stroke in which the fresh fuel mixture flows through the piston-controlled inlet port while at the same time the fumes are being exhausted through the outlet port. This in contrast with the four-stroke engines where the intake and exhaust are each done with two separate strokes. From the energy point of view, the two-stroke engine is not efficient because a certain amount of fresh fuel is being wasted in the exhaust fumes. We propose to replace the piston-controlled cam with the valve-flushed system, which will cause the combustion process to become more efficient. The purpose of this paper is to present various designs of the engine heads and analyse their performance. The goal of this proposal is to choose the best combination of these engine heads in order to achieve the optimum overall engine performance

Direct and indirect heat energy conversion into electricity

Conversion of heat energy into electricity is described. Energy conversion is the process of changing one form of energy to another. There are two methods of conversion: direct, when heat energy is converted directly into electricity and indirect, when heat energy is converted into mechanical energy first and afterwards into electricity. A principle of direct method is thermoelectric effect that includes three separately identified effects: the Seebeck effect, the Peltier effect and the Thomson effect. In case of heat energy conversion into electricity, we are talking about Seebeck effect. For indirect method, first heat energy is converted to mechanical energy. The principle is gas compression and expansion due to temperature change that is used i.e.: steam engine, Stirling heat engine or polish engine WASE2. The engine is based on the fundamental physical phenomena. The next step is to convert mechanical energy into electricity. The principle is electromagnetic induction that produces an electromotive force across a conductor when it is exposed to a time varying magnetic field. Electromagnetic induction is used in i.e.: generators, alternators or American type generators

Assessment of the effect of mechanical vibrations and platelet-rich plasma on the healing of tibial stems treated with the elastic carbon stabilizer „Carboelastofix"

Analizie poddano 9 owiec z gatunku owca wrzosówka - średni wiek owiec 5 lat. Zwierzęta podzielone zostały na 3 grupy, po 3 w każdej. U wszystkich owiec dokonano przecięcia trzonu kości podudzia stabilizując odłamy stabilizatorem Carboelastofix. W grupie pierwszej, kontrolnej, nie stosowano ani stymulacji mechanicznej ani biochemicznej. W grupie drugiej zastosowano stymulację mechaniczną wzbudnikiem piezoelektrycznym mocowanym do nośnika stabilizatora zewnętrznego. W grupie trzeciej zastosowano stymulację mechaniczną oraz dodatkowo śródoperacyjnie podane zostało do szczeliny złamania autogenne osocze bogatopłytkowe. Analiza zrostu prowadzona była na podstawie zdjęć rentgenowskich wykonywanych w 2, 5 i 8 tygodniu po operacji. Po zakończeniu eksperymentu zwierzęta zostały uśmiercone, a powstała wokół szczeliny złamania kostnina została poddana badaniu histologicznemu oraz analizie w badaniu mikrotomografii komputerowej. We wszystkich trzech grupach uzyskano zrost kostny. Analiza gęstości tworzącej się kostniny prowadzona na postawie badań obrazowych nie wykazała znamiennych różnic pomiędzy badanymi grupami, jednakże gęstości tworzącej się kostniny w grupie ze stymulacją mechaniczną była najniższa. Autorzy dowodzą tym samym, że przy zastosowaniu elastycznego stabilizatora umożliwiającego mikroruchy poosiowe w szczelinie złamania podczas naturalnego obciążania kończyny, efekt dodatkowej stymulacji mechanicznej jest nie istotny dla poprawienia jakości formującego się zrostu kostnego. Osocze bogatopłytkowe w przypadku prawidłowo postępującego zrostu złamania nie wpływa na jakość tworzącej się kostniny.9 Wrzosowka sheep were analyzed - average age: 5 years. The animals were divided into three groups, each with 3 sheep. All the sheep underwent the cutting of the shin stem and the fractions were stabilized with the Carboelastofix stabilizer. In the first, control group, no mechanical or biochemical stimulation was performed. In the second group, mechanical stimulation was applied, with the use of a piezoelectric inductor, mounted in the carrier of the external stabilizer. The third group involved the application of mechanical stimulation and, additionally, autogenic platelet-rich plasma was mid-surgically applied in the fracture gap. The growth analysis was performed on the basis of the X-ray pictures taken in the 2nd, 5th and 8th week after the surgery. After the experiment had been finalized, the animals were put to death, and the callus formed around the fracture was histologically examined and analyzed in a computer microtomography test. All the three groups involved bone growth. The analysis of the density of the forming callus performed on the basis of the imaging examinations did not exhibit significant differences between the tested groups; however, the density of the forming callus in the group involving mechanical stimulation was the lowest. In this way, the authors prove that, with the application of an elastic stabilizer enabling axial micromovements in the fracture during the natural limb load, the effect of the additional mechanical stimulation is insignificant for the improvement of the quality of the forming bone growth. The platelet-rich plasma, in the case of the proper fracture growth, does not affect the quality of the forming limb