785 research outputs found

    Ultrasound-guided percutaneous treatment of a calcific acromioclavicular joint: A case report

    Get PDF
    Rationale:Calcific tendinopathy is one of the most frequent causes of nontraumatic shoulder pain. However, intra-articular calcifications appear to be an infrequent condition. We herein report a rare case study of an intra-articular calcification of the acromioclavicular joint.Patient concerns:A 46-year-old man presented with an acute pain in the anterior superior region of the left shoulder which also radiated to the left cervical region. The man during the physical evaluation also presented severe functional limitation of the shoulder movements in all planes of motion.Diagnoses:The diagnosis was carried out through a radiographic and an echotomographic examination, highlighting the intra-articular calcific formation associated to a reactive inflammatory reaction.Interventions:An ultrasound-guided percutaneous treatment following the guidelines for calcific tendinopathy of the shoulder was carried out.Outcomes:The posttreatment was satisfactory with the disappearance of the pain and the recovery of the shoulder movements in all planes of motion.Lessons:We can affirm that the ultrasound-guided percutaneous treatment in patients with calcification of the acromion-clavicular joint represents a valid and nonpainful therapeutic treatment

    Phenomenology and Semiotics. Crossing Perspectives.

    Get PDF
    In recent years the study of relationships between semiotics and phenomenology seems to be entering a period of renewed vitality and creativity (CADIOT & VISETTI 2001; ROSENTHAL & VISETTI 2008; 2010; PIOTROWSKI 2009; FONTANILLE 2008; BONDÌ 2012). For a variety of theoretical and historical reasons, there has been a constant osmosis between phenomenological and semiotic methods. In short, on one side, the works and investigations of phenomenologists have provided essential tools to semiotics. To give just an example: the greimasian semiotics theory refers to the process of meaning formation in terms of perceptual apprehension thanks to his original recovery of Merleau-Ponty’s perception theory. On the other, and at the same time, phenomenology is engaged in describing the activity of language and, in particular, the speaking activity (prise de la parole) of a subject which is a “beingin- the-world” (être-au-monde) and a “being-in-the-language” (être-au-langage): this is the paradigmatic case of Merleau-ponty and of his own model of linguistic gesture as emblem of expression. Furthermore, and more deeply, phenomenology and semiotics are methods rather than disciplines (BORDRON 2011). By means of the epoché, phenomenology has tried to return the articulation of the sensible and of the intelligible, and, on the other, the connections between subjectivity and intersubjectivity. Similarly, semiotics has proposed methods of analysis that are applicable to a wide range of domains:from narrative values to social identities, from textual traces to cultural practices with particular reference to their conditions of emergence. In this simultaneously archaeological and constructive orientation, phenomenology and semiotics have brought new challenges concerning the description of the phases of the meaning constitution

    Recycling of Heterogeneous Mixed Waste Polymers through Reactive Mixing

    Get PDF
    Anything that is not recycled and/or recovered from waste represents a loss of raw materials. Recycling plastics can help to reduce this loss and to reduce greenhouse gases, improving the goal of the decarbonization of plastic. While the recycling of single polymers is well assessed, the recycling of mixed plastics is very difficult because of the strong incompatibility among the different polymers usually present in urban waste. In this work, heterogeneous mixed polymers, i.e., polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyethylenetherephthalate (PET) were processed using a laboratory mixer under different conditions of temperature, rotational speed and time to evaluate the effect of the above parameters on morphology, viscosity and mechanical properties of the final blends. Morphological analysis shows a strong incompatibility between the polyethylene matrix and the other dispersed polymers. The blends show, of course, a brittle behavior, but this behavior slightly improves with decreasing temperature and increasing rotational speed. A brittle-ductile transition was observed only at a high level of mechanical stress obtained by increasing rotational speed and decreasing temperature and processing time. This behavior has been attributed to both a decrease in the dimensions of the particles of the dispersed phase and to the formation of a small amount of copolymers that act as adhesion promoters between matrix and dispersed phases

    Physicochemical characterization of passive films on niobium by admittance and electrochemical impedance spectroscopy studies

    Get PDF
    An analysis of the electronic properties of amorphous semiconductor–electrolyte junction is reported for thin (Dox < 20 nm) passive film grown on Nb in acidic electrolyte. It will be shown that the theory of amorphous semiconductor–electrolyte junction (a-SC/El) both in the low band-bending and high band-bending regime is able to explain the admittance data of a-Nb2O5/El interface in a large range (10 Hz–10 kHz) of frequency and electrode potential values. A modelling of experimental EIS data at different potentials and in the frequency range of 0.1 Hz–100 kHz is presented based on the theory of amorphous semiconductor and compared with the results of the fitting of the admittance data obtained in a different experiment. Some preliminary insights on the possible dependence of the density of state (DOS) distribution on the mobile defects concentration and mechanism of growth of anodic film on valve metals are suggested

    The genus Mauritanica O. Boettger, 1879 (Gastropoda Sty-lommatophora Clausiliidae) in Tunisia

    Get PDF
    Currently, the genus Mauritanica O. Boettger, 1879 (Gastropoda Stylommatophora Clausiliidae) is widespread in north-eastern Algeria and central-northern Tunisia with six taxa. The taxonomic position of this genus has often been interpreted differently and the relationship with other similar genera, in particular with Siciliaria Vest, 1867, still remains to be clarified. In this paper, we provide a further contribution to the knowledge of Mauritanica by analyzing morphologically (shell, genitalia, and the type museum material) all the known Tunisian populations. In particular, the geographical spread and taxonomy of M. tristrami s.l. (L. Pfeiffer, 1861), M. philora s.l. (Letourneux, 1887), M. perinni polygyra (O. Boettger, 1879), and M. cossoni (Letourneux, 1887) are redefined. Mauritanica perinni zaghouanica (Letourneux, 1887) could be a valid taxon. M. tristrami zribensis n. ssp., M. tristrami nouirasaidi n. ssp. and M. philora bognanii n. ssp. are described

    Recent advances on physico-chemical characterization of passive films by EIS and differential admittance techniques

    Get PDF
    Thin Nb2O5 anodic films (20 nm thick) grown in phosphoric acid solution have been characterised by EIS and differential admittance study in a large range of potential and frequency. The overall electrical behaviour has been interpreted by means of the theory of amorphous semiconductor Schottky barrier in presence of a non-constant density of states (DOS). A comparison of DOS for films grown in different electrolytes is reported

    Effect of moisture content on the processing and mechanical properties of a biodegradable polyester

    Get PDF
    This work is focused on the influence of moisture content on the processing and mechanical properties of a biodegradable polyester used for applications in injection molding. The pellets of the biodegradable polyester were exposed under different relative humidity conditions at a constant temperature before being compression molded. The compression-molded specimens were again placed under the above conditions before the mechanical testing. With all these samples, it is possible to determine the effect of moisture content on the processing and mechanical properties separately, as well as the combined effect of moisture content on the mechanical properties. The results obtained showed that the amount of absorbed water—both before processing and before mechanical testing— causes an increase in elongation at break and a slight reduction of the elastic modulus and tensile strength. These changes have been associated with possible hydrolytic degradation during the compression molding process and, in particular, with the plasticizing action of the moisture absorbed by the specimens

    Photo-oxidative and soil burial degradation of irrigation tubes based on biodegradable polymer blends

    Get PDF
    Irrigation tubes based on biodegradable polymers were prepared via an extrusion-drawing process by Irritec and compared to conventional pipes made of high-density polyethylene (HDPE). A commercial polylactide/poly (butyleneadipate-co-butyleneterephthalate) (PLA/PBAT) blend (Bio-Flex®) and Mater-Bi® were used. The polymers were characterized from rheological and mechanical points of view. Irrigation pipes were subjected to photoaging with continued exposure to UV radiation up to 22 days. The degradability in the soil of irrigation tube samples was studied. The influence of temperature and UV irradiation on soil burial degradation was investigated. A soil burial degradation test was carried out at 30 °C and 50 °C for up to 70 days. The degree of degradation was evaluated from the weight loss percentage. The degradation rate of irrigation tube samples based on Mater-Bi® was higher at 30 °C and was stimulated after 14 days of UV irradiation. Higher temperatures or UV aging encouraged the disintegration in soil of Bio-Flex®-based irrigation tubes. Furthermore, tube samples, before and after UV and soil burial degradation, were analyzed by Attenuated Total Reflection-Fourier Transform Infra-Red (ATR-FTIR) spectroscop
    • …
    corecore