Sludges generated during purification of water for human consumption are produced in large volumes and have high environmental polluting potential. The sludge dewatering technique using geotextile closed systems has been used to reduce the sludge volume for final disposal. It is a system that allows encapsulation, insulation, dewatering and disposal of sludge, which allows control of the input and output variables of the system. Also known as geotextile tubes, geotextile containers and geotextile bags are a function of their size. This work presents a discussion about the main factors influencing this sludge dewatering technique and its applicability for sludges generated in a water treatment plant. The study includes tests with single filling and with refilling the small geotextile bags in equipment constructed to simulate control of operational conditions, such as flow rate and pumping pressure. The evaluated performance of this system according to parameters proposed in the literature is also presented. The results obtained indicate that the efficiency of the dewatering technique depends on both the characteristics of the sludge and the geotextile properties. This study indicates the importance and efficiency of the dewatering technique in geotextile closed systems in reducing the sludge volume for final disposal.

Maintaining satisfactory properties in geosynthetics exposed to factors that could lead to their degradation needs to be considered in projects employing these materials. Geosynthetics subjected to tensile creep and weathering can undergo premature degradation over time. It is essential to study the influence of these factors, since they could act simultaneously in some applications. To assess the synergetic effects, frames were developed and four groups of a woven geotextile polypropylene sample were tested. The first and second groups were subjected to tensile creep at 5% and 10% of the tensile strength in conjunction with weathering for 2160 h. The third group was exposed to the same weathering conditions without tensile load. The fourth group was subjected to tensile creep at 10% of the tensile strength in laboratory conditions. Frames were built with a slope similar to the location of exposure to guarantee greater effects of weathering on the material surface. A meteorological station at the site monitored the meteorological parameters. The degradation suffered by the geotextile was determined by comparing tensile strength test results. The results presented show the importance of the constructed frames in assesssing tensile creep and weathering in the field under small loads.

Platelet-rich fibrin (PRF), a second-generation platelet concentrate, was developed for the purpose of overcoming the limitations of Platelet-rich plasma (PRP). PRF can produce a higher cumulative release of growth factors than PRP. Also, this release is slow and prolonged, making it ideal for tissue regeneration and growth stimulation. This study was conducted to evaluate the efficacy of fluid PRF either alone or combined with needling versus PRP in the treatment of atrophic acne scars. A comparative study including 30 patients with atrophic acne scars who were divided into two equal groups. Group I included 15 patients in which the left side of the face was treated with intradermal injection of PRP while the right side was treated with combined needling with PRP. Group II included15 patients in which the left side of the face was treated with intradermal injection of fluid PRF while the right side was treated with combined needling with fluid PRF. All patients received four sessions with 3 weeks interval. The acne scars significantly improved in both sides of face in both groups. According to quartile grading scale and patient satisfaction; the therapeutic response was significantly higher in PRF group than PRP either alone or combined with needling. The combination with needling increases efficacy of PRF and PRP. Fluid PRF is highly effective, safe and simple procedure that can be used instead of PRP in the treatment of acne scars.

The use of digital images to evaluate geotextile characteristics has appeared in the scientific literature, particularly for estimating the pore size distribution (PSD) of nonwoven geotextiles used for filtration purposes. While numerous image analysis techniques for PSD curve estimation have been proposed, automation of the analysis methods has received almost no attention. The goal of the present study is to quantify PSD curves from images of representative geotextile specimens using a fully automatic algorithm and considering the concept of largest inscribing opening size. These features are incorporated in a software program (GeotexInspector) developed by the second author. GeotexInspector is based on the concept of classification using the Support Vector Machine technique and digital image processing. These techniques are combined to develop a tool with a robust learning algorithm to identify geotextile fibers and pores. PSD curves from continuous filament and staple fiber nonwoven geotextiles are estimated using GeotexInspector and then compared with theoretical models that have appeared in the literature. The results indicate that the curves obtained from image analysis are in good agreement with model outcomes for models focused on the structure of geotextiles that are similar to the geotextiles used in this study.