Utjecaj dvostrukog prevlačenja na mehanička i tribološka svojstva keramičkih prevlaka

U radu su opisana dva postupka nanošenja slojeva prevlake. Prvi sloj Al2O3 nanesen je postupkom plazma naštrcavanja na nehrđajući čelik (EN X22CrMoV121). Nakon njega je nanesen sloj ZrO2 postupkom sol-gel, uranjanjem. Parametri koji su se mijenjali pri sol-gel postupku su: temperatura toplinske obradbe ZrO2 sloja (400ºC, 700ºC, 1000ºC) i broj uranjanja u otopinu kod temperature 700ºC (ponavljan 4 i 8 puta), kako bi se vidio njihov utjecaj na svojstva prevlake. Na prevlakama je provedena materijalografska analiza ispitivanih ZrO2 prevlaka, te je izmjerena debljina, tvrdoća i modul elastičnosti. Ispitivana je otpornost na brazdanje prevlaka, otpornost na abraziju te definiran koeficijent trenja metodom "Ball on disc". Rezultati provedenih laboratorijskih ispitivanja pokazali su da različite temperature toplinske obradbe, kojoj se podvrgavaju uzorci prevlaka nakon geliranja i sušenja i broj slojeva ZrO2, utječu na cjelovitost prevlake kao i na mehanička svojstva prevlaka. Nanošenje prevlake ZrO2 na Al2O3 prevlaku značajno smanjuje koeficijent trenja u odnosu na uzorke bez ZrO2 prevlake

Erozija nodularnog lijeva česticama kvarcnog pijeska

Ductile cast iron has high fatigue strength due to the spherical shape of graphite, especially after quenching and tempering. Higher toughness can be achieved by austempering. One of the advantages of ductile cast iron in relation to other cast irons is its good wear resistance. In the experiments, samples of ductile cast iron and austempered ductile cast iron were eroded with quartz sand particles at six different angles of impact (15°, 30°, 45°, 60°, 75° and 90°). The test results were presented as the loss of mass which occured during the test. Testing with quartz sand shows that the particle erosion resistance of ductile cast iron was better than that of austempered ductile iron for all impact angles except for 60°. The maximum measured wears of ductile cast iron and austempered ductile iron were at 75°.Nodularni lijev ima veliku dinamičku izdržljivost zbog kuglastog oblika grafita, naročito nakon poboljšavanja. Visoka žilavost može se postići izotermičkim poboljšavanjem. Jedna od prednosti nodularnog lijeva u odnosu na ostale željezne lijevove je njegova dobra otpornost na trošenje. U ovom istraživanju ispitivana je otpornost na erozijsko trošenje nodularnog lijeva i izotermički poboljšanog nodularnog lijeva, česticama kvarcnog pijeska pri šest različitih kutova udara (15°, 30°, 45°, 60°, 75° and 90°). Rezultati ispitivanja prikazani su gubitkom mase tijekom ispitivanja. Rezultati pokazuju da nodularni lijev ima bolju otpornost na erozijsko trošenje od izotermički poboljšanog nodularnog lijeva pri svim kutovima udara osim kod 60°. Maksimalni gubitak mase kod oba materijala zabilježen je pri kutu upada od 75°

PSYCHOTIC DISORDERS AND COMORBIDITY: SOMATIC ILLNESS VS. SIDE EFFECT

Background: Schizophrenia often co-occurs with chronic medical illnesses. Beside comorbid somatic illness, somatic symptoms appear as a result of side effects of antipsychotics during treatment of psychotic disorders, which may lead to certain diagnostic problems in deciding regarding the origin of such symptoms (somatic illness vs. side effects). The aim of this article is to review literature regarding comorbidity of psychotic disorders and somatic disorders and to point at possible diagnostic problems in differentiating comorbid somatic illness from side effects of antipsychotics. Content analysis of literature: Literature research included structured searches of Medline and other publications on the subject of comorbidity of psychotic disorders and somatic disorders and possible diagnostic problems in differentiating comorbid somatic illnesses from side effects of antipsychotics. Conclusion: Co-occurrence of schizophrenia and somatic illnesses is frequent. Genetic factors, sedentary life style, poor diet, risk behaviors and smoking are some important factors that contribute to such comorbidity. Side effects of antipsychotics may cause diagnostic problems in deciding regarding the origin of such symptoms (somatic illness vs. side effects) during treatment of psychotic disorders. Bearing in mind frequent comorbidity between of psychotic and somatic disorders, early recognition of such comorbidity is important, as well as the selection of antipsychotics. It is important to recognize psychotic symptoms in patients with somatic illnesses, as well as somatic illness in patients primarily treated because of psychotic disorder

METABOLIC SYNDROME IN PATIENTS WITH PSYCHOTIC DISORDERS: diagnostic issues, comorbidity and side effects of antipsychotics

Background: Metabolic syndrome and other cardiovascular risk factors are highly prevalent in people with schizophrenia. Metabolic syndrome can contribute to significant morbidity and premature mortality and should be accounted for in the treatment of mental disorders. Along with results of numerous investigations regarding metabolic syndrome, different issues have occurred. The aim of this article is to review literature regarding diagnostic and treatment of metabolic syndrome and point at some issues regarding diagnostic and treatment of metabolic syndrome in patients with psychotic disorders and in general population. Content analysis of literature: Literature research included structured searches of Medline and other publications on the subject of metabolic syndrome, particularly diagnostic and treatment of metabolic syndrome in patients with psychotic disorders and in general population. Conclusion: Despite numerous investigations of metabolic syndrome, many issues remain unclear, becoming objectives for future research. The experts disagree in their opinions on particular issues, such as clustering risk factors, importance of particular diagnostic procedures for the early detection and monitoring of metabolic syndrome and the role of antipsychotics in occurrence of metabolic syndrome. There is, however, unique attitude about importance of early detection and treatment of metabolic syndrome as well as necessity of further investigations

Bamboo Bicycle – Past or Future?

In this article the experiment was carried out to establish tensile strength values of two different bamboo species, which are obtained by the static tensile test. The tensile strength results of two tested species Tonkin Cane and Ku Zhu bamboo are presented and compared with traditional materials used for bicycle frame to determine their suitability for designing a frame. Physiology and other properties of bamboo were elaborated as well. The purpose of this study was to gain more knowledge on bamboo and prove his suitability in use as an alternative for ecologically unacceptable materials. Therefore, application of the natural materials is essential for the sustainable development. The fact that they have unlimited resources the use of bamboo has great potential and this article explains why

METABOLIC SYNDROME IN PATIENTS WITH PSYCHOTIC DISORDERS: diagnostic issues, comorbidity and side effects of antipsychotics

Background: Metabolic syndrome and other cardiovascular risk factors are highly prevalent in people with schizophrenia. Metabolic syndrome can contribute to significant morbidity and premature mortality and should be accounted for in the treatment of mental disorders. Along with results of numerous investigations regarding metabolic syndrome, different issues have occurred. The aim of this article is to review literature regarding diagnostic and treatment of metabolic syndrome and point at some issues regarding diagnostic and treatment of metabolic syndrome in patients with psychotic disorders and in general population. Content analysis of literature: Literature research included structured searches of Medline and other publications on the subject of metabolic syndrome, particularly diagnostic and treatment of metabolic syndrome in patients with psychotic disorders and in general population. Conclusion: Despite numerous investigations of metabolic syndrome, many issues remain unclear, becoming objectives for future research. The experts disagree in their opinions on particular issues, such as clustering risk factors, importance of particular diagnostic procedures for the early detection and monitoring of metabolic syndrome and the role of antipsychotics in occurrence of metabolic syndrome. There is, however, unique attitude about importance of early detection and treatment of metabolic syndrome as well as necessity of further investigations

The Influence of Applied Force on Aluminium Foams Energy Absorption

Aluminium foams are composite materials made of aluminium or, frequently, of aluminium alloys. They have cellular structure consisting of metal matrix and gas filled pores and are occasionally produced with extrusion technologies. One of the ways to produce foamed aluminium is to mix Al powder with a blowing agent. That way, the blowing agent releases gas at higher temperatures and at the end, with different technologies and methods, such as extrusion technology, mixture is compacted. Nine samples of aluminium foams were produced from the following precursor Alulight AlMgSi0,6 titanium hydride TiH2 (cylindrical shaped, dimension ø42 × 79,5 mm, relative density between 0,186 and 0,268. Aluminum foam investigated in this work had closed cells where quasi-static uniaxial compression was used to determine how applied force influences aluminium foams energy absorption properties. For energy absorption it is important to determine the critical force that will activate the maximum amount of absorbed energy. The dependence of energy absorption capacity and energy absorption efficiency on the compressive force was investigated, and then the obtained results were compared for different samples. By increasing the force, the energy absorption capacity of higher density foams increases faster. The energy absorption efficiency at low forces does not depend on the density of the samples but with increase of force, higher density foams become more efficient

DEPRESSIVE DISORDERS AND COMORBIDITY: SOMATIC ILLNESS VS. SIDE EFFECT

Background: The rate of comorbid depression and medical illness varies from 10 to 40%. Patients with depressive disorder compared to general population more often have cardiovascular and cerebrovascular disorders, diabetes, irritable bowel syndrome, and some types of tumor. Side effects of mental health medications may appear in a form that is very similar to clinical presentation of somatic illness. Side effects that appear during treatment of depressive disorder, e. g. cardiovascular, gastrointestinal, movement disorders, etc., may provoke certain diagnostic issues regarding origin of such symptoms (somatic illness vs. side effect). The aim of this article is to review literature regarding comorbidity of depressive disorder and somatic illness and to point at possible diagnostic problems in diferentiating comorbid somatic illness and side effects of antidepressants. Content analysis of literature: Literature research included structured searches of Medline and other publications on the subject of comorbidity of depressive disorder and somatic disorders and possible diagnostic problems in differentiating comorbid somatic illnesses from side effects of antidepressants. Conclusion: Comorbidity between depressive disorder and various somatic disorders appears often. Investigations suggest that depressive disorder is underdiagnosed in such cases. Side effects of antidepressants are sometimes very hard to diferentiate from symptoms of somatic illness, which may lead to diagnostic issues. Bearing in mind frequent comorbidity between of depressive and somatic disorders, early recognition of such comorbidity is important, as well as the selection of antidepressant. It is improtant to recognize depressive disorder in patients with somatic illnesses, as well as somatic illness in patients primarily treated because of depressive disorder