Search results for "METAL"
showing 10 items of 7908 documents
A flexible robotic cell for in-process inspection of multi-pass welds
2020
Welds are currently only inspected after all the passes are complete and after allowing sufficient time for any hydrogen cracking to develop, typically over several days. Any defects introduced between passes are therefore unreported until fully buried, greatly complicating rework and also delaying early corrections to the weld process parameters. In-process inspection can provide early intervention but involves many challenges, including operation at high temperatures with significant gradients affecting acoustic velocities and, hence, beam directions. Reflections from the incomplete parts of the weld would also be flagged as lack-of-fusion defects, requiring the region of interest (ROI) t…
Determination of Sorption Properties of Heavy Metals in Various Biosorbents
2018
Abstract Various techniques of determination of properties of physicochemical processes of heavy metal sorption in biosorbents were analysed. The methods of preparing and storing samples, conditions of experiment performance, as well as the methods of data interpretation were discussed. Two procedures of study were analysed: (1) in the static system of biosorbent-solution contact and (2) in the system of dynamic flow of solution. Copper cation sorption was studied. The effect of consecutive stages of the study on the quality of final results was shown. A high degree of uncertainty of the sorption capacity assessment was reported, which was dependent on the manner of conducting the study. Th…
Modelling load-transmission mechanisms in axially loaded RC columns retrofitted with steel jackets
2018
The use of steel jacketing technique is a common practice for retrofitting existing reinforced concrete (RC) columns, as it allows increasing load-carrying capacity and ductility of the member. When the external jacket has no-end connections – i.e. the jacket is indirectly loaded- the load sustained by the column is transferred from the inner RC core to the external jacket through shear stresses along the contact surface. The assessment of this mechanism is quite complex, due to the marked non-linear behaviour of constituent materials and to the calibration of a proper shear stress-relative slip constitutive law of the concrete-to-steel interface. In this paper, a step-by-step analytical ap…
The application of electroanalytical methods to determine affinity series of metal cations for functional biosorbent groups
2018
Abstract The affinity of the selected heavy metal cations: Mn 2 + , Ni 2 + , Cu 2 + , Zn 2 + , Cd 2 + , Pb 2 + and Na + , K + , Mg 2 + , Ca 2 + was determined for the functional groups located on the surface of leached barley middlings, so called Brewer's spent grain (BSG) – a by-product of the brewing industry. A simple method for determining the affinity series, with the use of a conductivity meter and a pH-meter, was described. It was demonstrated that the affinity of cations for the functional groups located on the surface of the BSG increases in the series: Na + + 2 + 2 + ≈ Zn 2 + 2 + ≈ Ca 2 + 2 + 2 + 2 + , and the series was determined by comparing concentrations expressed in gram e…
Shear bond strength and debonding characteristics of metal and ceramic brackets bonded with conventional acid-etch and self-etch primer systems: an i…
2016
Background: Different in-vitro studies have reported various results regarding shear bond strength (SBS) of orthodontic brackets when SEP technique is compared to conventional system. This in-vivo study was designed to compare the effect of conventional acid-etching and self-etching primer adhesive (SEP) systems on SBS and debonding characteristics of metal and ceramic orthodontic brackets. Material and Methods: 120 intact first maxillary and mandibular premolars of 30 orthodontic patients were selected and bonded with metal and ceramic brackets using conventional acid-etch or self-etch primer system. The bonded brackets were incorporated into the wire during the study period to simulate th…
Rosmarinic Acid Activates AMPK to Inhibit Metastasis of Colorectal Cancer
2018
Rosmarinic acid (RA) has been used as an anti-inflammatory, anti-diabetic, and anti-cancer agent. Although RA has also been shown to exert an anti-metastatic effect, the mechanism of this effect has not been reported to be associated with AMP-activated protein kinase (AMPK). The aim of this study was to elucidate whether RA could inhibit the metastatic properties of colorectal cancer (CRC) cells via the phosphorylation of AMPK. RA inhibited the proliferation of CRC cells through the induction of cell cycle arrest and apoptosis. In several metastatic phenotypes of CRC cells, RA regulated epithelial–mesenchymal transition (EMT) through the upregulation of an epithelial marker, E-cadherin, and…
Mineral Profile of Children’s Fast Food Menu Samples
2017
Abstract Children’s fast food menus, including hamburgers served with french fries, dessert, and a soft drink, were analyzed to obtain the mineral profile of trace elements. The developed analytical methodology involved sample digestion under pressure inside a microwave oven with a mixture of HNO3 and H2O2 and inductively coupled plasma-optical emission spectrometry. The method was validated by carrying out the analysis of certified reference materials (NIST 1570a spinach leaves, NCS ZC73016 chicken, and NIST 1568a rice flour) and using recovery experiments. Repeatability was verified by analyzing replicate samples. Twenty-six elements were studied, 12 of which—aluminum, barium, calcium, co…
The Role of Matrix Metalloproteinases (MMP-2 and MMP-9) in Ageing and Longevity: Focus on Sicilian Long-Living Individuals (LLIs)
2020
Extracellular matrix metalloproteinases (MMPs) are a group of proteins that activate substrates by enzymatic cleavage and, on the basis of their activities, have been demonstrated to play a role in ageing. Thus, in order to gain insight into the pathophysiology of ageing and to identify new markers of longevity, we analysed the activity levels of MMP-2 and MMP-9 in association with some relevant haematochemical parameters in a Sicilian population, including long-living individuals (LLIs, ≥95 years old). A cohort of 154 healthy subjects (72 men and 82 women) of different ages (age range 20-112) was recruited. The cohort was divided into five subgroups: the first group with subjects less than…
The function of matrix metalloproteinase-9 (MMP-9) and its tissue inhibitor (TIMP-1) in several clinical conditions: Results and analysis of our surv…
2021
The goal of this research was to evaluate the plasma concentration of MMP-9 and its tissue inhibitor (TIMP-1) in different clinical conditions. It included several groups of subjects: 31 overweight subjects; 91 obese adults divided into two subgroups according to the BMI value (BMI 30–35 Kg/m2 and BMI > 35 Kg/m2); 90 subjects with metabolic syndrome (MS) divided into two subgroups (with and without diabetes mellitus); 100 subjects with preclinical carotid atherosclerosis (PCA) divided according to the number of cardiovascular risk factors and to the insulin resistance degree; 48 subjects with obstructive sleep apnoea syndrome (OSAS) divided according to the apnoea/hypopnea index (AHI); 2…
Expression of Alpha-Enolase (ENO1), Myc Promoter-Binding Protein-1 (MBP-1) and Matrix Metalloproteinases (MMP-2 and MMP-9) Reflect the Nature and Agg…
2019
Breast cancer is a complex and heterogeneous disease: Several molecular alterations cause cell proliferation and the acquisition of an invasive phenotype. Extracellular matrix (ECM) is considered essential for sustaining tumor growth and matrix metalloproteinases (MMPs) have been identified as drivers of many aspects of the tumor phenotype. Mounting evidence indicates that both &alpha