Physical modelling and numerical finite element method (FEM) simulation of forging in open die of alloy AIMgSi0,5

This paper researches the process of forging in open die of gradual axial-symmetric workpiece made of alloy AIMg-Si0,5. The physical modelling was carried out, for which an original method for physical discretisation and numerical FEM analysis was developed. The components of tensor were determined: strain, strain rate, stress and the corresponding effective parameters. The results obtained experimentally and through a numerical FEM simulation were compared and analysed

Microstructural evolution during friction stir welding of AlSi1MgMn alloy

This paper provides the research of the infl uence of geometric and kinematic parameters on the microstructure and mechanical properties of welded joint of aluminum alloy AlSi1MgMn (6082-T6) obtained through the Friction Stir Welding (FSW) process. The experiment parameters were welding speed, rotation speed, angle of pin slope, pin diameter and shoulder diameter. On the obtained welded workpieces the dynamic testing on the impact toughness, and determination of microstructural zones were carried out

Normal and reversed phase high performance liquid chromatography of some new 1, 2, 4-triazole derivatives

The retention behaviour and separation ability of normal and reversed phase HPLC with one non-polar and two polar mobile phases, have been studied by measuring the retention constants of a series of newly synthesized 1,2,4-triazole derivatives. The results are discussed in terms of the nature of the solute, eluent and stationary phase

Mikrostrukturni razvitak AlSi1MgMn slitine tijekom zavarivanja trenjem

This paper provides the research of the influence of geometric and kinematic parameters on the microstructure and mechanical properties of welded joint of aluminum alloy AlSi1MgMn (6082-T6) obtained through the Friction Stir Welding (FSW) process. The experiment parameters were welding speed, rotation speed, angle of pin slope, pin diameter and shoulder diameter. On the obtained welded workpieces the dynamic testing on the impact toughness, and determination of microstructural zones were carried out.U radu se istražuje uticaj geometrijskih i kinematskih parametara na mikrostrukturu i mehanička svojstva zavarenog spoja od aluminijske slitine AlSi-1MgMn (6082-T6) dobivene postupkom zavarivanja trenjem (ZT). Parametri provedenih pokusa su brzina zavarivanja, kutna brzina okretanja alata, kut nagiba trna, promjer trna i promjer čela alata. Kod dobivenih zavarenih uzoraka izvedena su dinamička ispitivanja na udarnu žilavosti i određene su mikrostrukturne zone

Primena višekriterijumske analize u upravljanju procesom proizvodnje u mlekarskoj industriji

The high level of competition in the milk processors imposes higher standards in production, but also an innovative approach in relation to consumers. Their goal is to attract as many consumers and achieve a better market position. The research topic of this doctoral thesis is the possibility of applying the method of multi-criteria analysis in the quantification of the economic effects of the management of raw materials’ quality and the processing of milk, as well as the quantification of the subjective perception of consumers about the quality of products in the dairy industry. The main aim of the dissertation, to make the ranking dairies, is not directed only to the quality criteria that are based on the perception of the consumer, but also includes other relevant indicators on the basis of which must be assessed process of milk production. Raw materials’ quality and the processing of milk as two important indicators are also included in the evaluation process, so as to determine a composite index based on which the ranking is made dairy, use the three sets of criteria: (1) criteria for the assessment of raw materials’ quality in dairy industry (2) criteria for the quality assessment of processing of milk and (3) criteria for the evaluation of the perception of consumers about the quality of dairy products. The dissertation, in addition to the theoretical dimension, includes the implementation of a multi-criteria analysis method, TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) method on data collected through empirical research. Starting from the set of scientific hypotheses, it is expected that consumer perception will not change depending on dairies whose products are used and that the cumulative value of the indicator for quality dairy products will not differ from the quality expected by the consumer, as the results of analyzes disproved. What is still expected as a result, which is also refuted is that there are correlations on the routes: the production process of secondary indicators and indicators of consumer perceptions about the quality of dairy products, raw milk production indicators and indicators of consumer perceptions about the quality of dairy products, indicators of consumer perceptions the quality of dairy products and dairy market share and ultimately, to the rank of dairy composite index established by multi-criteria analysis and their market share, financial results and dairies. The final result, which is related to the primary objective of this doctoral dissertation, is precisely in a detailed definition of the evaluation model for ranking dairies, which contributes to creating a scientific approach to ranking dairy, as well as the determination of the composite index as an indicator of the success achieved in the management of the production process in the dairy industry

Indicators of inflammation and proteasis/antiproteasis system and their relation to lung function and clinical caracteristics of patients with chronic obstructive pulmonary disease

Uvod/Cilj: Hronična opstruktivna bolest pluća (HOBP) predstavlja značajan javno zdravstveni problem u celom svetu jer su njena učestalost i posledice u stalnom porastu, naročito u zemljama sa značajnom populacijom pušača. Procene oboljevanja za 2010.godinu su ukazale na 384 miliona slučajeva HOBP uz godišnji mortalitet od 2,9 miliona ljudi [1-3]. Hronična opstruktivna bolest pluća (HOBP) se karakteriše ograničenjem protoka vazduha koje nije potpuno reverzibilno. Ograničenje protoka vazduha je obično progresivno i udruženo sa poremećenim inflamacijskim odgovorom pluća na štetne čestice ili gasove [4,5]. Pacijente obolele od HOBP odlikuje stanje pojačane inflamacije i oksidativnog stresa, pojačane proteolize ekstracelularnog matriksa i neravnoteže u proteaza/antiproteaza sistemu, uz prateće patomorfolološke promene u smislu destrukcije alveola i remodelovanje disajnih puteva. Multikomponentna priroda bolesti podrazumeva pored patoloških promena u disajnom stablu i plućima, i sistemske efekte sa zahvatanjem drugih organskih sistema: kardio-vaskularnog sistema, mišića i kostiju, metabolizma, kognitivnih svojstva i raspoloženja. Cij ovog istraživanja je bio da se ispitaju nivoi pokazatelja sistemske inflamacije i sistema proteaza/antiproteaza i utvrdi njihova povezanost sa pokazateljima plućne funkcije i kliničkim karakteristikama pacijenata sa hroničnom opstruktivnom bolesti pluća. Metod: Ovim istraživanjem su bili obuhvaćeni svi pacijenti sa dijagnozom hronične opstruktivne bolesti pluća koja je postavljena prema GOLD kriterijumima (engl. Global Initiative for Chronic Obstructive Disease - GOLD) [1]) i lečeni su u periodu od maja 2017.godine do januara 2018.godine na Odeljenje za astmu, HOBP i hroničnu respiracijsku insuficijenciju Klinike za pulmologiju KCS. Učestvovalo je ukupno 98 ispitanika, starijih od 40 godina, pušači i bivši pušači, u stabilnoj fazi bolesti, bez drugog respiratornog oboljenja. Kontrolnu grupu je činilo 47 zdravih ispitanika uparenih po polu i godinama. Na pregledu je učinjeno ispitivanje plućne funkcije: spirometrija, difuzijski kapacitet za ugljen-monoksid (CO), telesna pletizmografija...Introduction / Aim: Chronic Obstructive Pulmonary Disease (COPD) is a significant public health issue with a constant increase in disease incidence, especially in countries with a significant population of smokers. Predictions for year 2010 were 384 million cases of COPD with an annual mortality of 2.9 million people [1-3]. Chronic obstructive pulmonary disease (HOBP) is characterized by a limitation of airflow that is not completely reversible. The limitation of airflow is usually progressive and associated with an abnormal inflammatory response to the fumes or gases [4,5]. Patients with COPD are characterized by a state of increased inflammation and oxidative stress, enhanced extracellular matrix degradation and imbalance in the proteasis/antiproteasis system, with accompanying pathomorphologic changes of alveolar destruction and airway remodeling. Multicomponent nature of the disease includes pathological changes in the respiratory tract, as well as systemic effects with the involvement of other organ systems: cardio-vascular system, osteosceletal, metabolism, cognitive properties. The aim of this study was to asses the levels of systemic inflammation and the possible imbalance in protease / antiprotease system and to determine their relation to lung function parameters and clinical characteristics of patients with COPD. Method: This study included all patients diagnosed with COPD according to the Global Initiative for Chronic Obstructive Disease (GOLD) [1], and treated in the period from May 2017 to January 2018 in the Department of Asthma, COPD and chronic respiratory insufficiency in the Clinic for pulmonology, Clinical center of Serbia, Belgrade. Study included 98 subjects, aged 40 and over, smokers and former smokers, in a stable phase of COPD, with no other respiratory disease. Healthy control group included 47 subjects. All subjects completed pulmonary function testing (spirometry, diffusion capacity for carbon monoxide (CO), and body plethysmography), COPD Assessment Test (CAT) and the mMRC dyspnoea scale..

Influece of the austempering temperature on the tensile strength of the austempered ductile iron (ADI) samples

Austempered Ductile Iron (ADI) is a class of ductile iron subjected to a two-step heat treatment process – austenitization and austempering. The heat treatment gives to ADI a high value of tensile strength and an especially good strength-to-weight ratio. However, designers in most cases are unfamiliar with this material that can compete favorably with steel and aluminum castings, weldments and forgings. The high tensile strength of ADI is the result of its unique ausferrite microstructure. In this paper, an investigation of the influence of the austempering temperature on the tensile strength of the ADI samples is presented

Household food waste in Belgrade - sin and unconcern

The aim of this study was to examine the actual procedures with food in households and consumer attitudes about food waste. The survey was conducted in 83 households in Belgrade, Serbia. All participants were interviewed using a standardized questionnaire. The results obtained show that awareness of food waste is at a satisfactory level, but the actual situation is that food is discarded in large quantities, even though people are aware of what a global problem this is. Large contradictions were observed among the respondents answers in this study. Respondents who stated that they never discard food, in further responses, declared they throw away significant amounts of food for various reasons (too long storage, overconsumption, improper preparation, etc.). We conclude that people are either unaware of how much food they discard, or they do not want to admit it to themselves. However, participants largely have a sense of guilt about discarding food. This indicates consumer awareness of food waste, and is an encouraging sign that further education could be effective in consumers taking into account their food waste habits, starting from procurement planning, through storage and preparation

Assessment of gait in patients with fibromyalgia during motor and cognitive dual task walking: a cross-sectional study

Background: The aim of the study was to assess gait pattern of patients diagnosed with fibromyalgia (FM) while performing demanding motor and/or cognitive dual tasks while walking. Further, idea was to explore possible correlations of dual task gait pattern alterations to patients’ functional status and presence or absence of clinical symptoms associated with FM. Methods: Twenty-four female FM patients and 24 healthy female subjects performed a basic walking task, a dual motor, a dual mental (cognitive) and a combined, dual motor and cognitive task simultaneously. Quantitative spatial (stride length) and temporal (cycle time, swing time and double support time) gait parameters were measured using GAITRite walkway system and their variability was assessed. Patients underwent clinical examination including assessment of functional status, pain and fatigue level, psychiatric and cognitive manifestations. Results: The motor, cognitive and combined dual tasks affect gait performance in FM patients. Difference in tasks between FM and healthy subjects was found as double support time prolongation. Comparison of tasks showing that cycle time in FM was longer than controls and stride length was shorter in patients for all conditions, while no changes were found in any of the gait parameters variability. Further, mental/cognitive dual tasks had a larger effect than motor tasks. Correlations were also found between depression and functional status of the patients and the gait parameters. Conclusions: Gait is affected in FM patients while dual task walking. No changes in stride-to-stride variability point that patients preserve stability in complex walking situations. Analysis of gait may provide additional information for the FM identification based on presence of clinical features and cognitive status. Correlation of dual task gait alterations with occurrence of clinical symptoms and influence of cognitive changes on gait pattern could additionally define FM subgroups

Cavernous silicotuberculosis associated with diabetes

Od svih profesionalnih bolesti pneumokonioze su na prvom mjestu u Jugoslaviji. Poznato je da se silikoza i druge pneumokonioze razvijaju obično nakon dužeg radnog staža, pa, kako su to hronične bolesti, smrt nastaje najčešće u starijim godinama života. Bolesnik čiji ćemo slučaj prikazati oboleo je u mladim godinama od silikoze i umro u 31. godini života.A case of silicotuberculosis associated with diabetes mellitus is reported. The patient\u27s working conditions, the history of the disease and autopsy findings are discussed