The paper presents analytical relationships based on the theory of Green’s functions. The relationships refer to instantaneous and continuous as well as point and ring heat sources which are discussed. The relationship relating to continuous ring source is the basis for modelling and designing of spiral ground heat exchangers. Heat transfer in the infinite and semi-infinite body was considered. In the latter case, the image method was discussed. Using the results of measurements regarding heat transfer in the ground with a heat exchanger in the form of a single coil installed, a comparison of calculated ground temperatures with measured values was presented.

The work presents the process of drying wood biomass after pre-treatment involving either debarking or crushing. The biomass used for research came from a robinia species wood. The material was dried in free-convection, at the drying medium temperatures of 40, 50, 60, 70 and 80 ◦C, respectively. Pre- treatment proved to have a significant impact on the drying rate, including the time required to reach moisture content of 10%, essential to start further treatment of biomass for power industry purposes. It was found that debarked samples of robinia lost water more quickly than the crushed ones. Samples that did not undergo pre-treatment took the longest time to dry.

Poly(glycerol succinate) – PGSu – is one of glycerol polyesters which has focused nowadays the interest of scientists developing new biomaterials. Probably the polyester could be used as a drug carrier or as a cell scaffold in tissue engineering. Due to its potential use in medicine, it is extremely important to develop a synthesis and then optimize it to obtain a material with desired properties. In this work one flask two-step polycondensation of glycerol and succinic anhydride to PGSu is presented. Synthesis was optimized with the simplex method and also described using a second-degree equation with two variables (temperature and time) to better find the optimum conditions. PGSu was characterized by FTIR spectroscopy, NMR spectroscopy, degree of esterification was determined, and also molecular weight was calculated for each experiment using Carothers equation. A new synthesis route was developed and optimized. Temperature and time influence on molecular weight and esterification degree of obtained polyester are presented. Based on experiments conducted in this work, it was possible to obtain poly(glycerol succinate) with molecular weight of 6.7 kDa.

This paper presents an experimental study on Cochineal Red A dye adsorptive removal by yeast. Batch equilibrium and kinetic tests were conducted in constant temperature of 30 ◦C for the dye’s initial concentration range of 0.02–0.50 g/L (pH = 3 and 10) and 0.02–0.35 g/L (pH = 7:6). The equilibrium was reached after 105–120 min. Yeast demonstrated the adsorption capacity of 10.16 mg/g for acidic environment (pH = 3) and slightly lower values (8.13 mg/g and 8.38 mg/g respectively) for neutral (pH = 7:6) and alkaline environment (pH = 10). The experimental equilibrium results were fitted with Langmuir, Freundlich, Sips and Toth isotherm models. Most of them (Freundlich model being the exception) were proven sufficient for the experimental data correlation. The adsorption kinetic studies showed that the pseudo-second order model fits better the experimental data than the pseudo-first- order model. Results achieved from intra-particle diffusion model indicate that powdered yeast are a nonporous adsorbent. The percentage of solution discoloration reached a maximum value of 75% at pH = 3 for an initial dye concentration of 0.02 g/L.

Every change in the bottle geometry aswell as every change of physical and rheological properties poses a risk of excessive gas entrainment during a filling process. To maintain satisfactory filling efficiency there is a need to optimise this process with respect to all adverse phenomena which affect the fluid flow, such as spluttering on the bottom, air caverns formation and air entrainment with incoming liquid. This paper comprises numerical simulations of two filling methods. The first method involves dosing with a pipe placed over the free liquid surface of a fully filled bottle. The second method covers filling with a pipe located near the bottom. Moreover, the influence of rheological properties and surface tension values is considered. The comprehensive analysis of amount of entrained air represented by air volume fraction in dispensed liquid let the authors define the influence of filling speed on the mechanism and amount of entrapped air.

This paper aims to show the effect of activation method of tyre pyrolysis char (TPC) on adsorption of bisphenol A (BPA) from aqueous solutions. The TPC was produced from end-of-life-tyres (ELT) feedstock in a pilot plant at 773 K. Activation was accomplished using two classical methods: physical activation withCO2 and chemical activation withKOH. The two produced adsorbents had pores ranging from micro- to macropores. Distinct differences in the BET surface areas and pore volumes between the adsorbents were displayed showing better performance of the chemically activated adsorbent for adsorption of BPA from water.

The results of the kinetic studies showed that the adsorption of BPA followed pseudo-second-order kinetic model. The Freundlich, Langmuir, Langmuir–Freundlich and Redlich–Peterson isotherm equations were used for description of the adsorption data. The Langmuir–Freundlich isotherm model best fits the experimental data for the BPA adsorption on both adsorbents. The Langmuir–Freundlich monolayer adsorption capacity, qmLF, obtained for the CO2-activated tyre pyrolysis char (AP-CO2) and KOH-activated tyre pyrolysis char (AP-KOH) were 0.473 and 0.969 mmol g��1, respectively.