100 research outputs found
Oxidative stress is reduced in Wistar rats exposed to smoke from tobacco and treated with specific broad-band pulse electromagnetic fields
There have been a number of attempts to reduce the oxidative radical burden of tobacco. A recently patented technology, pulse electromagnetic technology, has been shown to induce differential action of treated tobacco products versus untreated products on the production of reactive oxygen species (ROS) in vivo. In a 90-day respiratory toxicity study, Wistar rats were exposed to cigarette smoke from processed and unprocessed tobacco and biomarkers of oxidative stress were compared with pathohistological analysis of rat lungs. Superoxide dismutase (SOD) activity was decreased in a dose-dependent manner to 81% in rats exposed to smoke from normal cigarettes compared to rats exposed to treated smoke or the control group. These results correspond to pathohistological analysis of rat lungs, in which those rats exposed to untreated smoke developed initial signs of emphysema, while rats exposed to treated smoke showed no pathology, as in the control group. The promise of inducing an improved health status in humans exposed to smoke from treated cigarettes merits further investigation
Biodegradability study of active chitosan biopolymer films enriched with Quercus polyphenol extract in different soil types
One of the recent trends within the circular economy is the development of materials derived from food processing waste and their utility as an alternative to plastic packaging. In this context, the study aims to evaluate biological causes of deterioration or degradation of chitosan-based films with and without incorporated natural Quercus polyphenol extract in three different types of soils (industrial compost, commercial garden soil, and soil from a vineyard). Degradation and active properties deterioration was followed by measurement of the loss of mass of tested active films for 14 days, and it was accompanied by other analytical techniques such as measurement of polyphenolic content, FT-IR analysis, and SEM examination of the packaging morphology. The results showed that chitosan-based film properties deteriorate in less than 3 days followed by biodegradation in all tested soils after 14 days. Films with incorporated Quercus polyphenol extract undergo deterioration of active properties in compost and garden soil in 6 days, while the fractionation and degradation process has not been complete in the vineyard soil during the 14 days. Furthermore, it has also been revealed that the addition of water to the soil decreased the rate of active chitosan film biodegradation in the terrestrial environment
Response of the Adriatic Sea to the atmospheric anomaly in 2003
Unusual weather conditions over the southern Europe and the Mediterranean area in 2003 significantly impacted the oceanographic properties of the Adriatic Sea. To document these changes, both in the atmosphere and the sea, anomalies from the normal climate were calculated. The winter 2003 was extremely cold, whereas the spring/summer period was extremely warm. The air temperature in June was more than 3 standard deviations above the average. On the other hand, precipitation and river runoff were extremely low between February and August. The response of the sea was remarkable, especially in surface salinity during spring and summer, with values at least one standard deviation above the average. Analysis of thermohaline properties in the middle Adriatic showed the importance of two phenomena responsible for the occurrence of exceptionally high salinity: (1) enhanced inflow of saline Levantine Intermediate Water (LIW) in the Adriatic, and (2) extremely low precipitation and river runoff, accompanied with strong evaporation. Two large-scale atmospheric indices: NAOI (North Atlantic Oscillation Index) and MOI (Mediterranean Oscillation Index), although generally correlated to the Adriatic climate, failed to describe anomalies in 2003. The air pressure gradients used for the definition of both indices significantly decreased in 2003 due to the presence of the high pressure areas over most of Europe and the northern Atlantic, and were actually responsible for the observed anomalies above and in the Adriatic
Flank wear and surface roughness in end milling of hardened steel
This study examines flank wear and surface ruoghness in up and down hard end milling. After obtaining the mathematical models, it has been carried out a series of numerical simulations with variation of input parameters in order to analyze their influence on flank wear and surface roughness. Additionally, flank wear and surface roughness has been analysed in correlation with the volume of the removed material for different cutting parameters. Observed from the viewpoint of machinability, down hard milling is favorable compared to the up hard milling
Optimization of cultivation medium for the production of antibacterial agents
Optimization of the cultivation medium for production of antibiotic effective
against pathogenic bacteria Staphylococcus aureus using strain of
Streptomyces spp. isolated from the environment represents the aim of this
study. After the biosynthesis, the medium was analyzed by determining
residual sugar and nitrogen, and the antibiotic activity was determined using
diffusion-disc method. Experiments were carried out in accordance with the
Box-Behnken design, with three factors varied on three levels (glucose: 10.0,
30.0 and 50.0 g/L; soybean meal: 5.0, 15.0 and 25.0 g/L; phosphates: 0.5, 1.0
and 1.5 g/L) and for the optimization of selected parameters Response Surface
Methodology was used. The obtained model with the desirability function of
0.985 estimates that the lowest amounts of residual sugar (0.89 g/L) and
nitrogen (0.24 g/L) and the largest possible inhibition zone diameter (21.88
mm) that with its antibiotic activity against S. aureus creates the medium
containing 10.0 g/L glucose, 5.0 g/L soybean meal and 1.04 g/L phosphates
From waste/residual marine biomass to active biopolymer-based packaging film materials for food industry applications- A review
Waste/residual marine biomass represents a vast and potentially underexplored source of biopolymers chitin/-
chitosan and alginate. Their isolation and potential application in the development and production of bio-based
food packaging are gaining in attractiveness due to a recent increment in plastic pollution awareness. Accordingly, a review of the latest research work was given to cover the pathway from biomass sources to biopolymers
isolation and application in the development of active (antimicrobial/antioxidant) film materials intended for
food packaging. Screening of the novel eco-friendly isolation processes was followed by an extensive overview
of the most recent publications covering the chitosan- and alginate-based films with incorporated active agents
Simple and Low-cost Fiber-optic Sensors for Detection of UV Radiation
In this paper two simple and low-cost fiberoptic sensors for detection of UV radiation are presented. A U-shaped sensor covered with an UV marker for UV radiation detection and a fiber-optic sensor with one end covered with powder from a mercury lamp are produced and described in details. Both sensors are made of large-core PMMA plastic optical fibers. As UV sources, a solar simulator and four different UV lamps are used. The light spectrum on the fiber output is measured by using an USB spectrometer. Dependence of output light intensity on the distance of end-type sensor with powder from a mercury lamp from UV lamp is investigated as well. On the output of the sensor covered with powder from a mercury lamp are obtained peaks of fluorescent emission at approximately 616 nm and 620 nm wavelengths
Change of temperature and vertical force during friction stir welding
Cilj rada je analiza promene vertikalne sile i temperature tokom procesa zavarivanja trenjem meÅ”anjem (FSW) legura aluminijuma visoke ÄvrstoÄe (2024 T3). FSW postupak je složen nelinearan proces praÄen velikim plastiÄnim deformacijama, visokim temperaturama i plastiÄnim teÄenjem materijala u zoni zavarivanja. To je postupak spajanja materijala u tzv. Ävrstoj fazi, kombinovanim delovanjem toplote i mehaniÄkog rada. Analiza promene sile i temperature tokom procesa zavarivanja omoguÄava bolje razumevanje i kontrolu samog procesa. U radu je analizirana i praÄena promena sile u vertikalnom pravcu pomoÄu dinamometra i promena temperature na gornjoj povrÅ”ini radne ploÄe u blizini Äela valjka alata pomoÄu termovizijske kamere.The aim of this paper is to analyze changes of vertical force and temperature during friction stir welding process of high strength aluminum alloys (2024 T3). FSW process is a complex nonlinear process accompanied by large plastic deformation, high temperatures and plastic material flow in the welding zone. It is the procedure of material connecting in the so-called solid phase, through the combined action of heat and mechanical work. Analysis of force and temperature changes during the process of welding allows better understanding and control of the process. This paper analyzes the change of force in the vertical direction using a dynamometer and temperature changes on the upper surface of the working panel near the tops of the roller tool using thermal imaging cameras
A Dataset of Labelled Objects on Raw Video Sequences
We present an object labelled dataset called SFU-HW-Objects-v1, which contains object labels for a set of raw video sequences. The dataset can be useful for the cases where both object detection accuracy and video coding efficiency need to be evaluated on the same dataset. Object ground-truths for 18 of the High Efficiency Video Coding (HEVC) v1 Common Test Conditions (CTC) sequences have been labelled. The object categories used for the labeling are based on the Common Objects in Context (COCO) labels. A total of 21 object classes are found in test sequences, out of the 80 original COCO label classes. Brief descriptions of the labeling process and the structure of the dataset are presented
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