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Abstract

This paper describes the separation of oxidation resistant components from the seeds of pomegranate (PSA), grape (GSE) and sea buckthorn (SSE). The anti-oxidation properties of the resultant extracts, used as the natural anti-oxidants for polypropylene (PP), were compared with Irganox1010. The effects of these natural antioxidants on the antioxidant levels of PP samples were estimated by thermal oxidative aging and micromixed rheology, OIT, XRD, SEM, TEM and mechanical properties tests of samples before and after aging. The results show that adding PSA, GSE and SSE can obviously increase the mechanical properties of PP. In addition, the molding stability of polypropylene raw material is prolonged and improved. Moreover, the mechanical properties of the PP samples after 240 h of thermal oxidative aging indicates that, the best results, closest to the anti-oxidation ability of Irganox1010, can be obtained when the additive amount is 0.5% (wt%) for PSE or 0.7% (wt%) for GSE.

Abstract

The current trend in development of new metallic materials for certain types of implants is turning away from permanent, biologically inert materials to the use of biodegradable materials. Fe–Mn alloys represent high perspective material for development of new generation of temporary and biodegradable implants. The aim of this work was to study mechanical and corrosion characteristics of powder samples containing 25, 30 and 35 wt % of Mn which are fabricated by pressing, sintering, and additional spark plasma sintering. The influence of preparation method (pressing and sintering) to microstructure, phased composition and corrosion behavior of prepared alloys was studied.

Abstract

Exposure of copper in corrosive environment is possible way, how to obtain artificial patina. Various solutions based on chloride, ammonia or polysulfide are commonly use in this purpose. Furthermore, it appears that the patina is also formed in an environment with an increased concentration of SO2 in the atmosphere. This procedure was tested in a small (30 l) exposure chamber, where the aggressiveness of the environment was monitored and where the effect of alternating the condensation and drying phases was shown to be positive. Based on this experiment, a 2 m3 pilot chamber was designed for which a water film sensor was developed and tested to ensure drying of the object surface. Monitoring of the aggressiveness of the environment showed that the pH and SO2 concentrations in the atmosphere are stable after approximately 5 hours and the ideal input SO2 concentration is 17.7 g m-3 at which the pH stabilizes at 2.7-3. By recording the voltage variation on the sensor, it was possible to monitor the formation and drying of the water film during the cycling of the condensation and drying phases.

Abstract

In this work, we have designed and synthesized the fluorescent probe 1, which was capable to selectively detect fluoride anion (F). More importantly, the probe 1 possessed near-infrared excitation and emission wavelengths (excitation at 650 nm and emission at 695), and the probe solution had changed dramatically from yellow to cyan with the addition of F. In addition, the fluorescence intensity exhibited perfectly positive correlation with concentration of F concentration from 0 to 40 μM (R2 = 0.9972), which offered the important condition for quantitative analysis. The probe 1 owned detection limit of 46 nM. Therefore, this near-infrared probe can be of great benefit for detecting F in practical application.

Abstract

Spray Drying Absorber (SDA) has been widely used for large-scale desulfurization. However, it also has some limitations. For example, the liquid absorbent easily causes scaling, which impedes the contact between the serous fluid and the flue gas and reduces the chemical reaction rate and desulfurization efficiency. This paper establishes the mathematical and physical model of gas and liquid two-phase flow and droplet evaporation and heat transfer in rotary spray desulfurization tower. To study the accumulation and distribution of chemical reaction precipitates in the desulfurization tower and analyze the removal efficiency of sulfur dioxide (SO2) in different atomization diameters, this paper establishes a simulation model concerning the coupling of desulfurization reaction and flow field calculation based on the absorption and reaction mechanism of SO2. Baffle in different widths are set to optimize the internal flow field and balance the distribution of flue gas. By setting baffles of different widths to optimize the flow field in the tower and changing the distribution of flue gas, this model reduces the scaling while ensuring the desulfurization efficiency. The results of the simulation experiment have verified that the droplet with a diameter of 50 μm is the optimal option, which can effectively remove the scaling and ensure that the desulfurizing tower runs in high efficiency and stability. When the width of baffles is 2250 mm, the efficiency of desulfurization exceeds 95%, and the amount of scaling on the desulfurization tower main wall is controlled at the minimum level, which is the optimal option for production.

Abstract

Simultaneous adsorption of heavy metals in complex multi metal system is insufficiently explored. This research gives results of key process parameters optimization for simultaneous removal of Cd(II), Co(II), Cr(III), Cu(II), Mn(II), Ni(II) and Pb(II) from aqueous solution (batch system). New lemon peel-based biomaterial was prepared and characterized by infrared spectroscopy with Fourier transformation (FTIR), scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS), while the quantification of metals was made by atomic absorption spectrometry (AAS). Simultaneous removal of seven metals ions was favorable at pH 5 with 300 mg/50 mL solid-liquid phase ratio, within 60 min at room temperature with total obtained adsorption capacity of 46.77 mg g−1. Kinetic modeling showed that pseudo-second order kinetic and Weber-Morris diffusion models best describe the adsorption mechanism of all seven heavy metals onto lemon peel.

Abstract

In this study, air flow controlled incinerator (AFCI) was used to treat medical solid waste in Vietnam. The experiment was conducted with solid waste samples that was weighed approximately 2.1–3.3 kg/h and had moisture content of 2.8–11.7%. The results showed that an increase in the airflow rate during the drying process accelerated the combustion time by 10–20%, and the optimal airflow rate was 1.1 m/s. The combustion time varied from 0–45 min. The highest temperatures recorded in the drying chamber, carbonisation chamber and combustion chamber after 25–35 min of operation were varied from 195°C, 775°C and 1275°C, respectively. The temperature of the stack was from 33–68°C after the treatment by the wet scrubber using 20% NaOH solution. The combustion capacity was 77.3–87.5%. The experimental results revealed the AFCI process advantages including low operation cost and suitability for treating hazardous waste on a small scale.

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Abstract

This article presents the results of testing the sound pressure level and sound power level of the experimental 3PW-KPF1-24-40-2-776 high-pressure gear pump. Acoustic tests were conducted in an reverberation chamber. The results of the acoustic power tests indicate good acoustic parameters of the tested high-pressure unit.

Abstract

This paper presents changes observed in the green areas in the city of Sopot. Analyses of Sopot archival materials, both cartographic and graphic, provided grounds for an assessment of changes and transformations in that respect starting from the 19th century. These analyses covered all the spa town protection zones A, B and C. This study also focuses on the aspect related with the primary function served by the spa town within the city. The city was also investigated in terms of the considerable cultural value frequently associated with green areas, since Sopot is an architectural gem of historical value. The analysis empasised the positive effect of green areas on the health resort character of the city. Green areas in the spa town of Sopot were analysed applying the comparative method. For this purpose maps and city maps were investigated. Additionally, the study is also based on archival graphic materials collected from the dawnysopot.pl website, as well as recent field studies (Świeczkowska, 2017).