The impact of mechanical pre-treatment of municipal solid waste (MSW) on its biogas production potential was examined. Mechanical separation allowed the following size-fractions to be obtained: fine fraction - mineral fraction of municipal solid waste (MFMSW) (cf> < 20 mm), middle fraction - organic fraction of municipal solid waste (OFMSW) (20 mm< cf>< 80 mm), and coarse fraction (cf>> 80 mm). The most suitable fraction for biological treatment was OFMSW, containing about 76 % of high rate biodegradable organic fraction (HRBOF). The rate constant of degradation for organic compounds in OFMSW was 0.23 d·1• It was shown that total gas production (TGP) during 10 years may achieve 550 m3/Mg OFMSW. Mechanical pre-treatment may allow an 45 % decrease of the amount of landfilled MSW resulting in a reduction of greenhouse gas emissions of up to 70 m3/Mg over 10 years of landfilling (in contrast to MSW landfilling - 213 m3/Mg). The experimental results revealed that gas production potential should be determined on the basis of HRBOF content and measurements of the biogas production.

The aim of the research was to show which theoretical statistical distribution best reflects and describes the variability of pollutant concentrations in treated sewage, discharged from small sewage treatment plants, characterised by a value below 2000 PE. The statistical analysis additionally takes into account the influence of the number of measuring sequence data on the shape and level of the distribution fit. The data for the research were obtained from three small sewage treatment plants, operating in the Lesser Poland, 10, 11 and 14 km from Kraków. Due to their size, these facilities are included in the group of treatment plants below 2000 PE. The research was conducted for 10 years. In the statistical analysis, 20-, 40-, 60- and 80-element data series were used, including the values of biochemical oxygen demand ( BOD₅), chemical oxygen demand ( COD_Cr) and total suspended solids ( TSS), determined in samples of treated wastewater. Two commonly used tests, Kolmogorov–Smirnov λ and Pearson’s X ² test were used to assess the fit of the theoretical statistical distribution to the empirical data distribution. Statistical analysis showed that the studied communities were characterised by an asymmetric, right-oblique distribution. Most often, the empirical distribution of the analysed measurement sequences was consistent with the Fisher–Tippett distribution. On the basis of the X ² test, this distribution was described by a total of 31 out of 36 analysed groups at the significance level of a = 0.05. Other distributions that often describe the analysed empirical data are: Gamma, log-normal, Chi-square, and Weibull. The common feature of these distributions is usually asymmetry, right oblique. The skewness value ranges from 0.15 to 1.69.

With the steady increase in the incidence of breast cancer in women, treatment that includes not only tumor removal but also breast reconstruction is becoming a more relevant issue for oncologic and plastic surgeons. Mastectomy recently evolved as a form of primary prevention of hereditary breast cancer, commonly performed in combination with simultaneous reconstruction. A case of 44-year-old woman who underwent right mastectomy with adjuvant radiotherapy is presented. Due to the patient’s positivity for BRCA1 mutation and her wishes, a risk-reducing mastectomy with nipple-areola complex preservation and bilateral deep inferior epigastric artery perforator flap reconstruction were performed in one-stage. In selected cases this method appears to be the best possible procedure for simultaneous preventative and reconstructive management in patients with genetically determined breast cancer who have undergone mastectomy with radiotherapy.

In the processes of coal mining, preparation and combustion, the rejects and by-products are generated. These are, among others, the rejects from the coal washing and dry deshaling processes as well as the coal combustion by-products (fly ash and slag). Current legal and industry regulations recommend determining the content of mercury in them. The regulations also define the acceptable content of mercury. The aim of the paper was to determine the mercury content in the rejects derived from the coal cleaning processes as well as in the combustion by-products in respect of their utilization. The mercury content in the representative samples of the rejects derived from the coal washing and dry deshaling processes as well as in the coal combustion by products derived from 8 coal-fired boilers was determined. The mercury content in the rejects from the coal washing process varied from 54 to 245 μg/kg, (the average of 98 μg/kg) and in the rejects from the dry deshaling process it varied from 76 to 310 μg/kg (the average of 148 μg/kg). The mercury content in the fly ash varied from 70 to 1420 μg/kg, (the average of 567 μg/kg) and in the slag it varied from 8 to 58 μg/kg (the average of 21 μg/kg). At the moment, in light of the regulations from the point of view of mercury content in the rejects from the coal preparation processes and in the coal combustion by-products, there are no significant barriers determining the way of their utilization. Nevertheless, in the future, regulations limiting the maximum content of mercury as well as the acceptable amount of leachable mercury may be introduced. Therefore, preparing for this situation by developing other alternative methods of using the rejects and by-products is recommended.

The paper presents an extensive review investigating the practical aspects related to the use of single- number ratings used in describing the sound insulation performance of partition wall panels and practical complications encountered in precise measurements in extensive frequency range from 50 Hz to 5 kHz. SWOT analysis of various single number ratings is described. A laboratory investigation on a double wall partition panel combination revealed the significant dependence of STC rating on transmission loss at 125 Hz attributed to 8 dB rule. An investigation conducted on devising alternative spectrums of aircraft noise, traffic noise, vehicular horn noise and elevated metro train noise as an extension to ISO 717-1 Ctr for ascertaining the sound insulation properties of materials exclusively towards these noise sources revealed that the single-number rating Rw + Ctr calculated using ISO 717-1 Ctr gives the minimum sound insulation, when compared with Rw + Cx calculated using the alternative spectrums of aircraft noise, traffic noise, etc., which means that material provides a higher sound insulation to the other noise sources. It is also observed that spectrum adaptation term Cx calculated using the spectrum of noise sources having high sound pressure levels in lower frequencies decreases as compared to ISO 717-1 Ctr owing to significant dependence of Ctr at lower frequencies.

The paper presents a methodology for the optimization of a Brushless Direct Current motor (BLDC). In particular it is focused on multiobjective optimization using a genetic algorithm (GA) developed in Matlab/Optimization Toolbox coupled with Maxwell from ANSYS. Optimization process was divided into two steps. The aim of the first one was to maximize the RMS torque value and to minimize the mass. The second part of the optimization process was to minimize the cogging torque by selecting proper magnet angle. The paper presents the methodology and capabilities of scripting methods rather than specific optimization results for the applied geometry.

In this paper, we propose and experimentally demonstrate a new method for optical frequency transfer over fibre. Instead of dual acousto-optic modulators (AOMs) as adopted in the traditional fibre phase noise compensation setup, here an active fibre phase noise compensation scheme with a single acousto-optic modulator (AOM) is used. The configuration simplifies the equipment of the user end while maintaining a high-performance optical frequency transfer stability. We demonstrate an actively stabilized coherent transfer at an optical frequency of 193.55THz over 10-km spooled fibre, obtaining a relative frequency stability (Allan deviation) of 3.84 × 10−16/1 s and 4.08 × 10−18/104 s, which is improved by about 2∼3 orders of magnitude in comparison with the one without any phase noise compensation that achieves a relative frequency stability of 1.81 × 10−14/1 s and 2.48 × 10−15/104 s.

The aim of this paper is to answer the question: Are the Łódź Hills useful for electrical energy production from wind energy or not? Due to access to short-term data related to wind measurements (the period of 2008 and 2009) from a local meteorological station, the measure – correlate – predict approach have been applied. Long-term (1979‒2016) reference data were obtained from ECWMF
ERA-40 Reanalysis. Artificial neural networks were used to calculate predicted wind speed. The obtained average wind speed and wind power density was 4.21 ms⁻¹ and 70 Wm⁻¹, respectively, at 10 m above ground level (5.51 ms⁻¹, 170 Wm⁻¹ at 50 m). From the point of view of Polish wind conditions, Łódź Hills may be considered useful for wind power engineering.