Selecting hardfacing technologies for ventilation mill suction plates and extending its working life

This paper presents results of the suction plate surface modification by hardfacing, of the ventilation mill in the Kostolac B power plant. Before applying hardfaced suction plates to exploitation conditions, it is necessary to study model hardfaced samples for determining the optimal tech-nology and filler material for revitalization. Experimental tests of revitalized mill suction plates in real exploitation conditions show that the proposed modification, hardfacing technologies and filler materials give good results. The relative weight loss of the suction plates after 1440 h period of exploitation in real conditions is 1-3%. The application of this approach can reduce the number of possible repairs and extends the period between them, resulting in significant economic effects

Selecting hardfacing technologies for ventilation mill suction plates and extending its working life

This paper presents results of the suction plate surface modification by hardfacing, of the ventilation mill in the Kostolac B power plant. Before applying hardfaced suction plates to exploitation conditions, it is necessary to study model hardfaced samples for determining the optimal tech-nology and filler material for revitalization. Experimental tests of revitalized mill suction plates in real exploitation conditions show that the proposed modification, hardfacing technologies and filler materials give good results. The relative weight loss of the suction plates after 1440 h period of exploitation in real conditions is 1-3%. The application of this approach can reduce the number of possible repairs and extends the period between them, resulting in significant economic effects

Retki slučaj intraorbitalnog stranog tela sa znacima penetracije rožnjače, koji su u početku ukazivali na anteriorni uveitisretki slučaj intraorbitalnog stranog tela sa znacima penetracije rožnjače, koji su u početku ukazivali na anteriorni uveitis

An unusual case is presented of an unsuspected orbital metallic foreign body (sewing needle) in a dog. The skin entrance wound injury was undetected during two clinical examinations, likely due to the quick skin healing and punctiform nature of the wound in the skin/muscles/orbit. The most unusual characteristic of this case is the cause of the wound. The metallic foreign body could have penetrated the cornea through an oblique limbal/scleral pathway at the moment of injury, leaving no obvious signs of corneal injury in the first clinical examination. Secondly, the corneal injury perhaps occurred due to the dog rubbing its head on the floor between the initial examination and the first follow-up examination after seven days. At first, the case presented as anterior uveitis with an unknown cause. Due to quick scar formation of wounds in dogs and the fact that punctiform wounds can be difficult to detect, an orbital foreign body was not initially suspected. However, seven days afterwards, a new sign of triangular limbus-based corneal opacification appeared. This led to suspicion of a previous corneal injury and the nearby (orbital) presence of a foreign body. This diagnosis was confirmed by radiography and the intraorbital sewing needle was extracted by surgery. Lack of sophisticated techniques did not prevent an adequate diagnosis and an excellent surgical outcome.Neobičan slučaj neočekivanog metalnog stranog tela u orbiti psa, prisutnog kao posledica punktiformne povrede na koži iglom koja nije uočena usled brzog zarastanja i kretanja kroz kožu, mišiće i orbitu. Najneobičnija karakteristika ovog slučaja je strano telo (šivaća igla) koje je penetriralo rožnjaču prolazeći kroz limbus i beonjaču pod kosim uglom, a u momentu povređivanja, kao i na prvom pregledu nije bilo znakova koji bi ukazivali na to ili je povreda rožnjače nastala češanjem glave o pod između prvog i drugog pregleda u razmaku od sedam dana. Na početku, slučaj je izgledao kao anteriorni uveitis nepoznatog uzroka i sedam dana kasnije se pojavilo trouglasto zamućenje rožnjače sa bazom prema limbusu što nas je dovelo u sumnju da je prethodna povreda rožnjače povezana sa orbitalnim stranim telom. Usled brzog zarastanja rana i formiranja ožiljka kod pasa i nedovoljno jasnih kliničkih znakova punktiformnih rana orbitalno strano telo nije bilo očekivano. Penetrantna rana na rožnjači je mogla nastati pre prvog pregleda ili u vremenu između prvog i drugog pregleda trljanjem glave. Nedostatak sofisticirane tehnike ne sprečava postavljanje tačne dijagnoze i primene adekvatne hirurgije

Microstructural and fracture analysis of microalloyed steel weld metal

In this paper is presented behavior of microalloyed steel weld metal with niobium during impact testing, as well as microstructural characterization. Impact tests were done on instrumented Charpy pendulum at room temperature, at -40 degrees C and -55 degrees C. At room temperature, crack propagation energy is much higher than crack initiation energy, while at -40 degrees C and -55 degrees C crack growth energy is lower than crack initiation energy. Fractographic investigation of the fracture surfaces has shown that at room temperature ductile trans-granular fracture is dominant, with a small amount of brittle trans-granular fracture. At lower temperature, the share of brittle fracture is increased, and inter-granular brittle fracture becomes dominan

Antioxidant Response in Gills of Eurasian Perch ( Perca fluviatilis ) to Cyanobacterial Bloom Exposure in the Gruža Reservoir

The aim of this study was to assess the impact of an Aphanizomenon flos-aquae bloom in the Gruža Reservoir on the antioxidant parameters measured in the gill cells of Eurasian perch (Perca fluviatilis). Effects of the bloom were evaluated through copper, zinc and manganese containing superoxide dismutase (CuZnSOD and MnSOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and biotransformation phase II enzyme glutathione-S-transferase (GST) activities and glutathione (GSH) and sulfydryl (–SH) groups concentrations. The activities of CuZn SOD and Mn SOD decreased during the cyanobacterial bloom compared to the period before the bloom. The opposite trend was observed for CAT and GSH-Px activities that increased. During the bloom GR and GST activities and GSH concentration decreased significantly. CuZn SOD, GR and GST activities are detected as the most important parameters for individual variations. Our results indicated that an A. flos-aquae bloom promotes oxidative stress in the gills of P. fluviatilis. The investigated parameters could be used in environmental risk assessment procedures to monitor the effects of A. flos-aquae blooms on fish. Observed changes in the antioxidant parameters in P. fluviatilis gills make them potential biomarkers in the research of ecological risk situations in freshwater ecosystems with frequent cyanobacterial blooms.Water Research and Management (2016), 6(2): 19-2

Effect of Shielding Gas Arc Welding Process on Cavitation Resistance of Welded Joints of AlMg4.5Mn Alloy

The effect of the shielding gas arc welding process on the cavitation resistance of the three-component aluminum alloy AlMg4.5Mn and its welded joints was investigated. Welding was performed using the GTAW and GMAW processes in a shielded atmosphere of pure argon. After the welding, metallographic tests were performed, and the hardness distribution in the welded joints was determined. The ultrasonic vibration method was used to evaluate the base metal’s and weld metal’s resistance to cavitation. The change in mass was monitored to determine the cavitation rates. The morphology of the surface damage of the base metal and weld metal due to cavitation was monitored using scanning electron microscopy to explain the effect of the shielding gas arc welding process on their resistance to cavitation. © 2023 by the authors

Antioxidant Response in Gills of Eurasian Perch ( Perca fluviatilis ) to Cyanobacterial Bloom Exposure in the Gruža Reservoir

The aim of this study was to assess the impact of an Aphanizomenon flos-aquae bloom in the Gruža Reservoir on the antioxidant parameters measured in the gill cells of Eurasian perch (Perca fluviatilis). Effects of the bloom were evaluated through copper, zinc and manganese containing superoxide dismutase (CuZnSOD and MnSOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and biotransformation phase II enzyme glutathione-S-transferase (GST) activities and glutathione (GSH) and sulfydryl (–SH) groups concentrations. The activities of CuZn SOD and Mn SOD decreased during the cyanobacterial bloom compared to the period before the bloom. The opposite trend was observed for CAT and GSH-Px activities that increased. During the bloom GR and GST activities and GSH concentration decreased significantly. CuZn SOD, GR and GST activities are detected as the most important parameters for individual variations. Our results indicated that an A. flos-aquae bloom promotes oxidative stress in the gills of P. fluviatilis. The investigated parameters could be used in environmental risk assessment procedures to monitor the effects of A. flos-aquae blooms on fish. Observed changes in the antioxidant parameters in P. fluviatilis gills make them potential biomarkers in the research of ecological risk situations in freshwater ecosystems with frequent cyanobacterial blooms.Water Research and Management (2016), 6(2): 19-2

Long-term air pollution exposure, genome-wide DNA methylation and lung function in the lifelines cohort study

BACKGROUND: Long-term air pollution exposure is negatively associated with lung function, yet the mechanisms underlying this association are not fully clear. Differential DNA methylation may explain this association. OBJECTIVES: Our main aim was to study the association between long-term air pollution exposure and DNA methylation. METHODS: We performed a genome-wide methylation study using robust linear regression models in 1,017 subjects from the LifeLines cohort study to analyze the association between exposure to nitrogen dioxide (NO2) and particulate matter (PM2.5, fine particulate ma

A cross-omics integrative study of metabolic signatures of chronic obstructive pulmonary disease

Abstract Background Chronic obstructive pulmonary disease (COPD) is a common lung disorder characterized by persistent and progressive airflow limitation as well as systemic changes. Metabolic changes in blood may help detect COPD in an earlier stage and predict prognosis. Methods We conducted a comprehensive study of circulating metabolites, measured by proton Nuclear Magnetic Resonance Spectroscopy, in relation with COPD and lung function. The discovery sample consisted of 5557 individuals from two large population-based studies in the Netherlands, the Rotterdam Study and the Erasmus Rucphen Family study. Significant findings were replicated in 12,205 individuals from the Lifelines-DEEP study, FINRISK and the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) studies. For replicated metabolites further investigation of causality was performed, utilizing genetics in the Mendelian randomization approach. Results There were 602 cases of COPD and 4955 controls used in the discovery meta-analysis. Our logistic regression results showed that higher levels of plasma Glycoprotein acetyls (GlycA) are significantly associated with COPD (OR = 1.16, P = 5.6 × 10− 4 in the discovery and OR = 1.30, P = 1.8 × 10− 6 in the replication sample). A bi-directional two-sample Mendelian randomization analysis suggested that circulating blood GlycA is not causally related to COPD, but that COPD causally increases GlycA levels. Using the prospective data of the same sample of Rotterdam Study in Cox-regression, we show that the circulating GlycA level is a predictive biomarker of COPD incidence (HR = 1.99, 95%CI 1.52–2.60, comparing those in the highest and lowest quartile of GlycA) but is not significantly associated with mortality in COPD patients (HR = 1.07, 95%CI 0.94–1.20). Conclusions Our study shows that circulating blood GlycA is a biomarker of early COPD pathology

An integrative cross-omics analysis of DNA methylation sites of glucose and insulin homeostasis

Despite existing reports on differential DNA methylation in type 2 diabetes (T2D) and obesity, our understanding of its functional relevance remains limited. Here we show the effect of differential methylation in the early phases of T2D pathology by a blood-based epigenome-wide association study of 4808 non-diabetic Europeans in the discovery phase and 11,750 individuals in the replication. We identify CpGs in LETM1, RBM20, IRS2, MAN2A2 and the 1q25.3 region associated with fasting insulin, and in FCRL6, SLAMF1, APOBEC3H and the 15q26.1 region with fasting glucose. In silico cross-omics analyses highlight the role of differential methylation in the crosstalk between the adaptive immune system and glucose homeostasis. The differential methylation explains at least 16.9% of the association between obesity and insulin. Our study sheds light on the biological interactions between genetic variants driving differential methylation and gene expression in the early pathogenesis of T2D