Povezanost socio-demografskih faktora i ličnih roditeljskih resursa za suočavanje sa stresnim situacijama

Предмет овог истраживања био је суочавање родитеља са сазнањем да дете има фактор и/или симптом ризика. Испитивање је обављено на узорку од 52 испитаника, односно родитеља оба пола путем онлајн (online) упитника. За прикупљање података о родитељима коришћен је анкетни лист о социо-демографским подацима, док је за суочавање са стресном ситуацијом коришћена скала - Преглед понашања родитеља у превазилажењу здравствених проблема у породици. Истраживањем је показано да не постоји статистички значајна разлика у суочавању са стресним ситуацијама у односу на пол, узраст, образовање, брачни статус, подршку партнера и број деце, али статистички значајна разлика постоји између испитаника који имају децу са фактором ризика и испитаника који имају децу са симптомом ризика. Тврдња (понашање) са којом су испитаници показали највећи степен слагања је „Посветити се свом детету“, док тврдња (понашање) са којим су испитаници показали најмањи степен слагања је „Веровање у Бога“ и „ Веровање да медицинска установа/болница ради оно што је за моје дете најбоље“.The subject of this research was confronting parents with the knowledge that a child has a factor and/or symptom of risk. The survey was conducted on a sample of 52 respodents, that is, parents of both sexes, through an online questionnaire. The Socio-demographic Survey Sheet was used to collect parent`s data, while the Coping Health Inventory for parents scale was used to cope with the stressful situation. The study found that there was no statistically significant difference in dealing with stressful situations concering gender, age, education, marital status, partner support and number of children, but a statistically significant difference existed between respodents who have children with risk factors and the ones with children who have a symptom of risk. The statement (behavior) with which the respondents showed the highest degree of agreement is „Commit to your children“, while the statement (behavior) with which the respondents showed the least degree of agreement is „ Belief in God“ and „ Belief that the medical institution / hospital does what is best for child“

MOGUĆNOST PRIMENE ULTRAZVUČNE KAVITACIJE U PROCESU PRERADE INDUSTRIJSKIH OTPADNIH VODA

With the development of industry and population growth in recent years, there are problems related to wastewater from production. All wastewater from the plant, regardless of how it was generated, contains harmful substances that may have a certain degree of toxic impurities and must be treated if their quality does not meet the legal framework. The goal of wastewater treatment is to remove harmful substances, which reduces the degree of pollution. Most of the pollutants are of organic origin and their removal can be realized by applying advanced techniques with ultrasound and ultrasonic cavitation to achieve water quality that complies with legal regulations. The principle of operation of ultrasound in wastewater treatment is based on the conversion of electricity into vibrations of a certain amplitude and frequency, which cause the decomposition and destroying of microorganisms and bacteria. Improved processes are the most efficient methods for removing and degrading sparingly soluble pollutants from wastewater. The purification process is optimized in regard to to the technological procedure, concentration, treatment time and the amount of oxidizing agent applied.Razvojem industrije i rastom populacije tokom poslednjih godina javljaju se problemi u vezi sa otpadnim vodama iz proizvodnje. Sve otpadne vode iz postrojenja, bez obzira kako su nastale, sadrže štetne materije koje mogu da imaju i određen stepen toksičnih primesa i moraju se prečistiti ako njihov kvalitet ne odgovara zakonskim okvirima. Cilj tretmana otpadnih voda je uklanjanje štetnih materija čime se postiže smanjenje stepena zagađenosti. Većina zagađujućih materija su organskog porekla i njihovo uklanjanje se može realizovati primenom naprednih tehnika ultrazvuka i ultrazvučne kavitacije, a sve u cilju postizanja kvaliteta vode u skladu sa zakonskom regulativom. Princip delovanja ultrazvuka u obradi otpadnih voda temelji se na pretvaranju električne energije u vibracije određene amplitude i frekvencije, koje izazivaju razgradnju i uništavanje mikroorganizama i bakterija. Unapređeni procesi predstavljaju najefikasnije metode za uklanjanje i degradaciju teško rastvornih zagađujućih materija iz otpadnih voda. Proces prečišćavanja je optimizovan u odnosu na tehnološki postupak, koncentraciju, vreme tretmana i količinu primenjenog oksidacionog sredstva

UTICAJ EFEKTA STAKLENE BAŠTE NA KLIMATSKE PROMENE

The burning of fossil fuels and other human activities in order to clear the land for the needs of agriculture or the construction of settlements, lead to increased emissions by releasing into the atmosphere gases that retain heat within it. The atmosphere, similar to glass, mostly passes the solar radiation, but it is poorly permeable to the radiation of the Earth's surface. Part of the energy that enters the Earth - atmosphere system remains in it and is converted into thermal energy, heating the Earth's surface and the lower layers of the atmosphere and leading to the appearance of the greenhouse effect. The greenhouse effect is the process of the planet Earth warming, caused by the disruption of the energy balance between the amount of radiation that the Earth's surface receives from the Sun and returns to space. Part of the heat radiation, which reaches the Earth's crust, is reflected into the atmosphere and instead of going into space, it is absorbed by some gases in the atmosphere and re-radiated to the Earth. In this way, the temperature of the Earth's surface rises. The gases that contribute the most to this phenomenon are carbon dioxide and methane and they build up in the atmosphere, trapping more and more heat near the Earth's surface thus causing the climate to warm. As a result, there are sudden changes, which lead to the parameters of global warming and climate change becoming unpredictable in the occurrence of frequent hurricanes, floods, cyclones and other weather disasters, melting of ice on the polar caps and glaciers, which cause an increase in the height of the seas and oceans, the impossibility of accurate prediction weather forecasts, etc. Greenhouse gas emissions are critical to understanding and addressing the climate crisis and must be reduced by 2030 to limit global warming to 1.5 °C compared to pre industrial levels by the end of the century.Sagorevanje fosilnih goriva i drugih ljudskih aktivnosti u cilju raščišćavanja zemljišta za potrebe zemljoradnje ili izgradnje naselja, dovode do povećane emisije, oslobađajući u atmosferu gasove koji zadržavaju toplotu unutar nje. Atmosfera, slično staklu, uglavnom propušta Sunčevo zračenje, ali je slabo propusna za zračenje Zemljine površine. Deo energije koji uđe u sistem Zemlja - atmosfera, ostaje u njemu i pretvara se u toplotnu energiju, zagrevajući Zemljinu površinu i niže slojeve atmosfere i dovodi do pojave efekta staklene bašte. Efekat staklene bašte je proces zagrevanja planete Zemlje koji je nastaje poremećajem energetske ravnoteže između količine zračenja koje Zemljina površina prima od Sunca i vraća u svemir. Deo toplotnog zračenja, koje stiže do Zemljine kore, odbija se u atmosferu i, umesto da ode u svemir, apsorbuju ga neki gasovi i ponovno zrače na Zemlju. Na ovaj način, temperatura Zemljine površine se povišava. Ovom fenomenu najviše diprinose gasovi ugljen-dioksid i metan koji se nagomilavaju u atmosferi, zadržavajući sve više toplote pri Zemljinoj površini, što uzrokuje otopljavanje. Kao posledicu toga, javljaju se nagle promene koje dovode da parametri globalnog zagrevanja i klimatskih promena postaju nepredvidivi u pojavama učestalih uragana, poplava, ciklona i ostalih vremenskih nepogoda, topljenja leda na polarnim kapama i glečerima, što uzrokuje porast visine mora i okeana, nemogućnost tačnog predviđanja vremenske prognoze i sl. Emisije gasova staklene bašte su od ključne važnosti za razumevanje i rešavanje klimatske krize i moraju se smanjiti do 2030. god., kako bi se ograničilo globalno zagrevanje na 1,5 °C u poređenju sa predindustrijskim nivoima do kraja veka

Cavitation resistance of composite polyester resin/basalt powder

The paper presents the results of research on cavitation resistance of the composite based on unsaturated polyester resin and basalt powder, as reinforcement. Basalt powder was obtained by grinding and micronising basaltic rocks from the Vrelo-Kopaonik deposit. Different amounts of basalt powder as reinforcement were applied (g): 0.15; 0.30; 045; 0,50. The mechanical properties (tensile strength, bending strength, hardness) and cavitation resistance properties were determined for the resulting composite. An ultrasonic vibration method (with stationary specimen) was applied according to ASTM G32 standard. Studies have shown that the mechanical properties and cavitation resistance of the composites increase with the addition of basalt powder as reinforcement

The Mechanisms of Cavitation Erosion of Raw and Sintered Basalt

The paper analyzes the morphology of cavitation damage of raw and sintered basalt samples. The experiment was conducted using the ultrasonic vibratory cavitation test method according to the ASTM G-32 standard. During the determination of the resistance to the effect of cavitation, a change in the mass of samples was observed in the function of the cavitation time of operation. The morphology of damage caused by the effect of cavitation was followed by scanning with an electron microscope, and the level of degradation of the surface of the samples was quantified using the image analysis. The results showed a significantly higher degree of resistance of sintered basalt, with a cavitation rate of 0.019 mg/min relative to raw basalt, with a cavitation rate of 0.738 mg/min. After 120 minutes of exposure to the cavitation effect, a smaller number of small pits on the surface of sintered basalt were observed, while a higher level of damage to the surface with the appearance of numerous pits was found in raw basalt, which can be connected in some places to larger and deeper pits in some places. The obtained results indicate the possibility of using sintered basalt for the production of parts that will be exposed to the effects of high cavitation loads

Cavitation resistance of turbine runner blades at the hydropower plant 'djerdap'

Hydropower plants need to develop means of protection of turbine and hydromechanical equipment from undesirable occurrences, such as degradation of parent material and/or weld metal of parts and structures caused by stresses and unpredictable influence of vibrations, fatigue, corrosion, erosion and cavitation. Results of tests that refer to the cavitation resistance of turbine runner blades made of cast steel 08X15H4 pi M pi, in accordance with GOST standard are presented in this paper. For the testing of cavitation resistance, the ultrasonic vibration test method is used (with the stationary sample), for which it is necessary to measure the mass loss during specified time intervals, while the cavitation resistance of the material is being defined, taking into account the incubation period and cavitation rate. Scanning electron microscope analysis is carried out to study the morphology of sample damage due to cavitation. The obtained results show that the tested steel has a good cavitation resistance and that fatigue is the main failure mechanism

Cavitation Wear of Basalt-Based Glass Ceramic

This paper examines the possibility of using basalt-based glass ceramics for construction of structural parts of equipment in metallurgy and mining. An ultrasonic vibration method with a stationary sample pursuant to the ASTM G32 standard was used to evaluate the possibility of the glass ceramic samples application in such operating conditions. As the starting material for synthesis of samples, olivine-pyroxene basalt from the locality Vrelo-Kopaonik Mountain (Serbia) was used. In order to obtain pre-determined structure and properties of basalt-based glass ceramics, raw material preparation methods through the sample crushing, grinding, and mechanical activation processes have been examined together with sample synthesis by means of melting, casting, and thermal treatment applied for the samples concerned. The mass loss of samples in function of the cavitation time was monitored. Sample surface degradation level was quantified using the image analysis. During the test, changes in sample morphology were monitored by means of the scanning electronic microscopy method. The results showed that basalt-based glass ceramics are highly resistant to cavitation wear and can be used in similar exploitation conditions as a substitute for other metal materials

QUALLITY MANAGEMENT OF PROCETIVE COATINGS BASED ON ZIRCONIUM SILICATE

The composition and production procedures of refractory coatings based on zirconium silicate for the protection of metal structures in conditions of wear, cavitation and corrosion were investigated in the paper. The composition of the coating was defined with a filler based on zirconium silicate, a binder based on epoxy resin, organic additives and an organic solvent. A method for quality control of obtained coatings was investigated using the ultrasonic vibration method with a stationary sample according to the ASTM G 32 standard. The following methods were used to characterize the obtained filler samples: X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The change in the mass of the samples as a function of the cavitation time was monitored and the cavitation rate was determined. The formation and development of damage to the coating surface was monitored using a scanning electron microscope. The obtained test results showed a satisfactory resistance of the protective coatings to the effect of cavitation, with small damage to the coating surface and a cavitation rate of 0.6 mg/min. Tests have shown that the application of the ultrasonic vibration method is suitable for a quick assessment of the quality of protective coatings during synthesis and a forecast of their resistance and stability during exploitation in the protection of equipment parts in mining and metallurgy

SYNTHESIS OF NEW REFRACTORY COATINGS BASED ON BASALT FOR FOUNDRY APPLICATIONS

This paper presents the results of research on coatings based on basalt for use in Lost foam casting process. These coatings have not been used in practice so far. The coating compositions and the synthesis process were studied. Test series of casting aluminum alloy castings were made. Positive results of testing the surface, structure and properties of the obtained castings are shown. The possibility of using basalt for the synthesis of coatings in foundry will enable great savings in the production of castings. This is significant considering that Serbia has significant reserves of this type of mineral raw materials

SYNTHESIS OF NEW REFRACTORY COATINGS BASED ON BASALT FOR FOUNDRY APPLICATIONS

This paper presents the results of research on coatings based on basalt for use in Lost foam casting process. These coatings have not been used in practice so far. The coating compositions and the synthesis process were studied. Test series of casting aluminum alloy castings were made. Positive results of testing the surface, structure and properties of the obtained castings are shown. The possibility of using basalt for the synthesis of coatings in foundry will enable great savings in the production of castings. This is significant considering that Serbia has significant reserves of this type of mineral raw materials