5 research outputs found
Analysis and modeling of the effects of process parameters on specific cutting energy in abrasive water jet cutting
The problem of cutting difficult-to-machine materials used in the aerospace
industry, aircraft industry, and automobile industry, led to the
development and application one of today’s most attractive technology for
contour cutting - abrasive water jet cutting. For the efficient use of
abrasive water jet cutting, it is of great importance to analyze the impact
of process parameters on performance indicators, such as cutting quality,
productivity, and costs. But also, from the energy utilization point of
view, it is very important to analyze the impact of these parameters on the
specific cutting energy which represents the amount of energy spent on the
removal of material in the unit time. Having this in mind, this study
presents the experimental results of abrasive water jet cutting of aluminum
alloy with the aim of creating a mathematical model for estimating specific
cutting energy as an important indicator of the degree of utilization of
the available energy in the cutting process. The mathematical model of the
specific cutting energy is explicitly represented as a non-linear function
of the process parameters, obtained by the artificial neural network. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR
35034
Modeling of cutting temperature in the biomedical stainless steel turning process
Stainless steel is widely used as material in many industries and medicine.
As biomedical material, it has been used for making devices, implants as well
as tools and equipment in surgery and dentistry. The most of them is
processed by turning. Modeling of temperature in the metal cutting process is
very important step in understanding and analysis of the metal cutting
process. The objective of this study is to develop an artificial neural
network model which can be used successfully for accurate prediction of
cutting temperature while performing turning of the biomedical stainless
steel. Before the modeling, cutting temperature was measured, as one of the
significant parameters in turning process, by using the infrared thermal
imaging camera. Finally, based on the mathematical model, the effects of the
turning parameters on the cutting temperature were examined
In vitro activity of heather [Calluna vulgaris (L.) Hull] extracts on selected urinary tract pathogens
Calluna vulgaris L. Hull (Ericaceae) has been used for treatment of urinary tract infections in traditional medicine. In this study we analyzed in vitro antibacterial activity of the plant extracts on different strains of Escherichia coli, Enterococcus faecalis and Proteus vulgaris, as well as the concentrations of total phenols and flavonoids in the extracts. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The concentrations of total phenols were examined by using Folin-Ciocalteu reagent and ranged between 67.55 to 142.46 mg GAE/g. The concentrations of flavonoids in extracts were determined using spectrophotometric method with aluminum chloride and the values ranged from 42.11 to 63.68 mg RUE/g. The aqueous extract of C. vulgaris showed a significant antibacterial activity. The values of MIC were in the range from 2.5 mg/ml to 20 mg/ml for this extract. Proteus vulgaris strains were found to be the most sensitive. The results obtained suggest that all tested extracts of C. vulgaris inhibit the growth of human pathogens, especially the aqueous extract
Change in plasma cytokine levels during risperidone treatment in children with autism
© Mary Ann Liebert, Inc. 2014. Background: Atypical antipsychotics decrease irritability in autism. They also affect the cytokine network. Psychological stress, depression, and, possibly, autism spectrum disorder (ASD) are associated with the production of pro-inflammatory cytokines. We sought to determine if risperidone treatment led to changes in plasma cytokine levels. Methods: Forty-five subjects from an open-label study of risperidone treatment of children and adolescents with ASD, ages 4-18 years, had an analysis of 27 different cytokines at baseline and after 8 weeks of treatment using multiplex assays (Millipore) and read on the Luminex 100 ™ platform. We examined changes in each of the cytokine levels in the entire group, and also compared changes in cytokines in responders versus nonresponders. Results: After 8 weeks of risperidone treatment, 2 of the 27 plasma cytokines showed statistically significant decreases in median levels: Eotaxin (p=0.0003) and monocyte chemoattractant protein-1 (MCP-1) (p=0.0024). Six of the 48 subjects met two criteria for responders to risperidone, and the median values of interleukin (IL)-5 were significantly higher (p=0.005) in the overall responder group than in nonresponders. Conclusions: Two cytokines, eotaxin and MCP-1, which have previously been identified as abnormally elevated in children with autism, decreased during treatment with risperidone. This suggests a possible mechanism of action of risperidone treatment and a balancing of the immune system in affected subjects in this very preliminary study