60 research outputs found

    Effects of heat treatment on the properties of low carbon steel 19MnB4 for screws

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    In this paper is given the research conducted at the specified quality screws which had different mechanical properties after completion of the same heat treatment. Results of chemical and metallographic analysis and hardness tests indicated the deficiencies that can be corrected in the course of production and thermal processing of finished products - screws

    A preliminary investigation of phytoplankton of karstic pools (Dugi otok island, Croatia)

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    Phytoplankton in the karstic pools of Croatian islands has not been investigated in recent times. This paper describes phytoplankton and environmental conditions in three karstic pools on Dugi Otok island (Dalmatia). The pools are small (ca 20 m2) and shallow (max. depth 2 m), with Charophytes and vascular plants covering the bottoms. Eighty-five taxa of net phytoplankton were recorded. These included 22 Cyanobacteria, 14 Chlorophyceae, 17 Charophyceae (Zygnematales), 15 Euglenophyceae, and 17 Bacillariophyceae. Low species richness is owed to the predominance of Cyanobacteria. Despite their similar physicochemical regimes, the pools had different phytoplankton communities. The data presented here contribute baseline information concerning biological diversity, essential for evaluation of environmental changes in the future. Conservation of karstic pools is one way to preserve the overall biodiversity of karstic islands

    Textural properties of infra red dried apple slices as affected by high power ultrasound pre-treatment

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    Drying is a process frequently used in food industry, often based on the use of conventional methods using heat exchange by conduction or convection. This kind of method may lead to quality loss in structure, texture and  sensory characteristics of final products. Consequently, the need for research of new drying methods arises.  One of such methods is power ultrasound aided drying. The aim of this work was to investigate the impact of  high power ultrasound pre-treatment on drying rate and textural properties of the infra red dried apple slices.  Ultrasound device working at a frequency of 24 kHz with a power capacity of 200 W was used for ultrasound  pre-treatment. The amplitudes used for ultrasonic pre-treatment were 50 and 100%. The results showed that  the use of different amplitudes of ultrasound reduces the time of drying and allows elimination of more water  from the apple slices. Usage of 50 and 100% of ultrasonic amplitude in great extent shortened the duration of  drying (up to 40%). The results showed that hardness of samples gradually increases (50% amplitude –  97.260 N; 100% of amplitude – 217.90 N) with increase of ultrasound intensity. As a result, hardness of  untreated apple slices (41.037N) was significantly lower (p < 0.05).Key words: High power ultrasound, amplitude, drying, apple

    A preliminary investigation of phytoplankton of karstic pools (Dugi otok island, Croatia)

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    Phytoplankton in the karstic pools of Croatian islands has not been investigated in recent times. This paper describes phytoplankton and environmental conditions in three karstic pools on Dugi Otok island (Dalmatia). The pools are small (ca 20 m2) and shallow (max. depth 2 m), with Charophytes and vascular plants covering the bottoms. Eighty-five taxa of net phytoplankton were recorded. These included 22 Cyanobacteria, 14 Chlorophyceae, 17 Charophyceae (Zygnematales), 15 Euglenophyceae, and 17 Bacillariophyceae. Low species richness is owed to the predominance of Cyanobacteria. Despite their similar physicochemical regimes, the pools had different phytoplankton communities. The data presented here contribute baseline information concerning biological diversity, essential for evaluation of environmental changes in the future. Conservation of karstic pools is one way to preserve the overall biodiversity of karstic islands

    Effects of heat treatment on the properties of low carbon steel 19MnB4 for screws

    Get PDF
    In this paper is given the research conducted at the specified quality screws which had different mechanical properties after completion of the same heat treatment. Results of chemical and metallographic analysis and hardness tests indicated the deficiencies that can be corrected in the course of production and thermal processing of finished products - screws

    Overlay Consolidation of ISP-Provided Preferences

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    There is growing evidence that mutually beneficial outcomes can be achieved when content distribution overlays and their underlying ISPs collaborate through open interfaces. We further contribute to this body of work by considering consolidated topology construction strategies that integrate the information provided by multiple ISPs. We focus on situations with potentially conflicting, asymmetric preference costs, since these situations are expected to benefit more from the tradeoffs provided by consolidation to produce an overlay topology with desirable global properties. In this paper we develop a generic model for the multi-domain consolidation of ISP preferences expressed as costs for pairwise peer connections, where peers are grouped into clusters based on topology criteria. Using this model, we propose two consolidated topology construction strategies: Shared Cost, designed to provide a tradeoff for preference cost asymmetries, and Low Cost, designed to reduce the overall preference cost that the overlay imposes on all its underlying ISPs. We evaluate these two models through extensive simulations over a wide range of ISP and peer cluster sizes, and we show that preference consolidation can provide ISPs with outcomes more aligned with their preferences than those provided by non-consolidated operation

    Antibacterial Fractions from Erodium cicutarium Exposed—Clinical Strains of Staphylococcus aureus in Focus

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    Followed by a buildup of its phytochemical profile, Erodium cicutarium is being subjected to antimicrobial investigation guided with its ethnobotanical use. The results of performed in vitro screening on Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans strains, show that E. cicutarium has antimicrobial activity, with a particular emphasis on clinical S. aureus strains— both the methicillin sensitive (MSSA) and the methicillin resistant (MRSA) S. aureus. Experimental design consisted of general methods (the serial microdilution broth assay and the agar well diffusion assay), as well as observing bactericidal/bacteriostatic activity through time (the “time‐kill” assay), investigating the effect on cell wall integrity and biofilm formation, and modulation of bacterial hemolysis. Observed antibacterial activity from above‐described methods led to further activity‐ guided fractionation of water and methanol extracts using bioautography coupled with UHPLCLTQ OrbiTrap MS4. It was determined that active fractions are predominantly formed by gallic acid derivatives and flavonol glycosides. Among the most active phytochemicals, galloyl‐shikimic acid was identified as the most abundant compound. These results point to a direct connection between galloyl‐shikimic acid and the observed E. cicutarium antibacterial activity, and open several new research approaches for future investigatio
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