Heat transfer study from the heated square cylinder at a different orientation angle to the stream of nanofluids has been investigated numerically. CuO-based nanofluids were used to elucidate the significant effect of parameters: Reynolds number (1–40), nanoparticle volume fraction (0.00–0.05), the diameter of the NPs (30–100 mn) and the orientation of square cylinder (0–90°). The numerical results were expressed in terms of isotherm contours and average Nusselt number to explain the effect of relevant parameters. Over the range of conditions, the separation of the boundary layers of nanofluids increased with the size of the NPs as compared to pure water. NPs volume fraction and its size had a significant effect on heat transfer rate. The square cylinder of orientation angle (45°) gained a more efficient heat transfer cylinder than other orientation angles. Finally, the correlations were developed for the average Nusselt number in terms of the relevant parameters for 45° orientation of the cylinder for new applications.

The objective of this study is to assess the physical-chemical quality of urban wastewater from the city of Boumerdès, in northern Algeria with regard to the threshold values for irrigation or their discharge in aquatic ecosystems. Five sampling points were carried out of the study area in April 2017. The results obtained of physical- chemical parameters indicating pollution show that the water course is exposed to pollution mainly of organic origin. It’s expressed by a high maximum value according to Algerian and World Health Organisation standards: chemical oxygen demand ( COD 886 mg O ₂∙dm ^–3), biochemical oxygen demand ( BOD ₅ 490 mg O2∙dm ^–3), nitrate (NO ₃ ^– 73.09 mg∙dm ^–3), nitrite (NO ₂ ^–6 mg∙dm ^–3), ammonium (NH ₄ ⁺ 23 mg∙dm ^–3) and phosphates (PO ₄ ^3– 7.3 mg∙dm ^–3). The COD to BOD ₅ rate of 1.8, show that the effluents must be treated before being discharged into the receiving environment. However, it is lower than 2, which makes them easily biodegradable and can be treated by a biological system such as a natural lagoon. It shows also a diversified origin of the pollution. It is predominantly domestic origin, it could have an adverse effect on public health, presenting a risk of environmental eutrophication, contamination of soil and water resources. The physical-chemical characterisation of the urban wastewater shows that they are quite loaded and present a pollution in nitrogenous compounds, a treatment is requested before the direct discharge to the receiving environment or their reuse in the irrigation.

The purpose of the study was to assess the effect of autologous activated platelet-rich plasma on healing of a bone substitute - tricalcium phosphate hydroxyapatite in experimental long bone defects using an animal model.

The experiment involved an animal model of femoral defect. 24 Termond white rabbits were used in the study. We evaluated the effect of autologous platelet-rich plasma on tricalcium phos- phate using classical radiology, micro-CT studies, strength tests and histological evaluation.

Radiological and histological assessment did not show a beneficial effect of PRP together with a bone substitute in comparison to filling the defects only with bone replacement material. The only benefit of adding platelet-rich plasma to a bone substitute was shown in microCT imaging.

Autologous, activated platelet-rich plasma combined with hydroxyapatite tricalcium phos- phate has a positive effect on the remodeling of the newly formed bone tissue, increasing its density.

Preliminary results of field investigations and analysis of air photos of the Tjörn Valley region (Wedel Jarlsberg Land, Spitsbergen) are presented. The youngest, Quaternary deposits and landforms were mapped. Reconstruction of the last advance and retreat of the Tjörndals Glacier is also described.

A series of copper oxide thin films were synthesized through direct current magnetron sputtering on glass and silicon substrates with various process parameters. Initially, optical microscopy images and their histograms were analyzed to determine the optical quality of the obtained layers and then histograms were created using Image Histogram Generator software. Next, the morphology, and cross-section and layer composition of the samples were evaluated. Finally, the transmission spectra of the thin films were recorded. Transmittance and reflection spectra of the UV–vis analysis were utilized to calculate the optical band gap, the extinction coefficient, and the absorption coefficient of the oxidized layers. Samples showed low transmittance (up to 40%) in the region of 400 to 1000 nm. The mean absorption coefficient varied from ~3 · 105 to ~6 · 105 1/cm and from ~2 · 105 to ~4 · 105 1/cm in the region of 2 eV to 3.5 eV. The extinction coefficient ranged from 0 to 0.11 in the region from 300 to 3000 nm. Reflectance of the samples was ~20% in the region of 1000 to 2500 nm and ranged from 20%-50% in the region of 1000 to 3000 nm. We verified the process parameters of the Cu2O structure to improve the quality as a buffer layer. On the basis of this preliminary analysis, we propose the most promising and future-oriented solutions in photovoltaic applications.