Mechanical properties of HDPE/textile fibers composites

AbstractThe use of natural fibers as reinforcement for thermoplastics has generated much interest due to the low cost, low density, high specific properties characteristics. In this work the mechanical properties of high density polyethylene/ textile fibers residues composites were studied. Effect of pretreatment with sulfuric acid on textile fibers to prepare composites was made to provide an improvement in mechanical properties of these materials. This treatment on fibers was evaluated by X-ray diffraction technique. Composites were produced in a thermokinetic mixer in the following composition: 5 and 10 wt% fibers. After mixing the samples were injection molding according to ASTM D-638 specification. Specimens were tested in tensile mode and composite fractures surface were analyzed in a scanning electron microscopy. Also was studied moisture absorption. Results showed that HDPE/ textile fibers residue presents good mechanical performance compared with high-density polyethylene

Occasional Finding Of Neurological Disorders During Children Hearing Loss Evaluation Using The Abr

One of the most important applications of the Brainstem evoked response audiometry (ABR) is in the evaluation of hearing loss in children. Today the ABR is also indicated in the screening of cochleovestibular syndromes to detect retrocochlear lesions, to monitor patients in a coma (brain death), in monitoring the brainstem during skull base surgery, etc. Among the many BERA qualities, is its capacity to evaluate the neurophysiologic integrity of the auditory brainstem pathway. In doing so, sometimes while evaluating hearing function in children we are faced with ABR waves that suggest the presence of retrocochlear lesions (trace asymmetry, increased interpeak intervals), many times confirmed through image studies. These cases are seen as occasional findings of neurologic disorders during children hearing loss evaluation. In this study we report 2 cases of neurologic disorders diagnosed with the use of the ABR to evaluate hearing loss in children. © Revista Brasileira de Otorrinolaringologia. All Rights reserved.733424428Jewett, D.L., Romano, M.N., Williston, J.S., Human auditory evoked potentials: Possible brain stem components detected on the scalp (1970) Science, 167 (924), pp. 1517-1518Starr, A., Hamilton, A.E., Correlation between confirmed sites of neurological lesions and abnormalities of far-field auditory brainstem responses (1976) Electroencephalogr Clin Neurophysiol, 41 (6), pp. 595-608Levine, R.A., Gardner, J.C., Fullerton, B.C., Stufflebeam, S.M., Carlisle, E.W., Furst, M., Effects of multiple sclerosis brainstem lesions on sound lateralization and brainstem auditory evoked potentials (1993) Hear Res, 68 (1), pp. 73-88Moller, A.R., Jannetta, P.J., Auditory evoked potentials recorded intracranially from the brain stem in man (1982) Exp Neurol, 78 (1), pp. 144-157Hashimoto, I., Ishiyama, Y., Yoshimoto, T., Nemoto, S., Brain-stem auditory-evoked potentials recorded directly from human brain-stem and thalamus (1981) Brain, 104 (PART 4), pp. 841-859Anson, B., Donaldson, J., (1981) Surgical anatomy of the temporal bone, , 3rd ed. Philadelphia: W.B. Saunders;Sousa LCA, Piza MRT, Costa SS. Poster: Brainstem Evoked Auditory Potential (ABR) in Neurology and Neurosurgery: 99th Meeting of the American Academy of Otolaryngology- Head and Neck Surgery. New Orleans, USA, Setembro1995Sousa, L.C.A., Piza, M.R.T., Costa, S.S., Diagnosis of Menières Disease: Routine and Extended Tests (2002) Otolaryngol Clin North Am, , JuneMarangos, N., Maier, W., Merz, R., Laszig, R., Brainstem response in cerebellopontine angle tumors (2001) Otol Neurotol, 22 (1), pp. 95-99Haapaniemi, J., Laurikainen, E., Jahansson, R., Rinne, T., Varpula, M., Audiovestibular findings and location of na acoustic neuroma (2000) Eur Arch Otorhinolaryngol, 257 (4), pp. 237-241Costa, S.S., Sousa, L.C.A., Cruz, O.L.M., Colli, B.O., Andrade, M.J., Rollin, G.A.F.S., Schwannoma vestibular: Apresentação atípica (1995) J Bras Neurosurg, 6 (2), pp. 41-48Sousa LCA, Piza MRT, Costa SS, Ferez M, Colli BO. Electrophysiologic Monitoring (ABR) of Coma Status,: 99th Meeting of the American Academy of Otolaryngology. Head and Neck Surgery, New Orleans, USA1995Coser, P.L., Menon, A.D., Electrophysiological study of auditory pathways and the vestibular system in tumor pathology of the 8th cranial nerve and of the cerebellopontile angle (1981) Rev Laryngol Otol Rhinol (Bord), 102 (5-6), pp. 239-24

Correlations between climate network and relief data

In the last few years, the scientific community has witnessed an ongoing trend of using ideas developed in the study of complex networks to analyze climate dynamics. This powerful combination, usually called climate networks, can be used to uncover non-trivial patterns of weather changes throughout the years. Here we investigate the temperature network of the North American region and show that two network characteristics, namely degree and clustering, have marked differences between the eastern and western regions. We show that such differences are a reflection of the presence of a large network community on the western side of the continent. Moreover, we provide evidence that this large community is a consequence of the peculiar characteristics of the western relief of North America

Disentangling the impact of environmental and phylogenetic constraints on prokaryotic within-species diversity

Microbial organisms inhabit virtually all environments and encompass a vast biological diversity. The pangenome concept aims to facilitate an understanding of diversity within defined phylogenetic groups. Hence, pangenomes are increasingly used to characterize the strain diversity of prokaryotic species. To understand the interdependence of pangenome features (such as the number of core and accessory genes) and to study the impact of environmental and phylogenetic constraints on the evolution of conspecific strains, we computed pangenomes for 155 phylogenetically diverse species (from ten phyla) using 7,000 high-quality genomes to each of which the respective habitats were assigned. Species habitat ubiquity was associated with several pangenome features. In particular, core-genome size was more important for ubiquity than accessory genome size. In general, environmental preferences had a stronger impact on pangenome evolution than phylogenetic inertia. Environmental preferences explained up to 49% of the variance for pangenome features, compared with 18% by phylogenetic inertia. This observation was robust when the dataset was extended to 10,100 species (59 phyla). The importance of environmental preferences was further accentuated by convergent evolution of pangenome features in a given habitat type across different phylogenetic clades. For example, the soil environment promotes expansion of pangenome size, while host-associated habitats lead to its reduction. Taken together, we explored the global principles of pangenome evolution, quantified the influence of habitat, and phylogenetic inertia on the evolution of pangenomes and identified criteria governing species ubiquity and habitat specificity

Classe de Mathématiques, réalité et communication

This study focuses on an inquiry-based teaching experience in mathematics, with 5th grade students in which we have established a strong connection with reality and intensified student’s ability to communicate, while promoting problem solving and mathematical reasoning. Mathematics lessons are organized into four phases: (i) Launching the task for students; (ii) Development of the task; (iii) Discussion of the task; and (iv) Systematization of mathematical learning. To prepare task discussion, the teacher implements a “gallery of tasks” through which students have their first contact with their colleague’s resolutions: they can ask questions and make comments in the presented sheets. This article presents the results of a lesson on percentages, in which students worked on the task entitled “Discount at Bit- @ - Byte”. The analysis of this task and the results of similar tasks of reality made throughout the school year shows that the inquiry-based teaching allows improvements in mathematics, namely learning concepts and capabilities such as reasoning, communication and problem solving

Strings on conifolds from strong coupling dynamics, part I

A method to solve various aspects of the strong coupling expansion of the superconformal field theory duals of AdS_5 x X geometries from first principles is proposed. The main idea is that at strong coupling the configurations that dominate the low energy dynamics of the field theory compactified on a three sphere are given by certain non-trivial semi-classical configurations in the moduli space of vacua. We show that this approach is self-consistent and permits one to express most of the dynamics in terms of an effective N=4 SYM dynamics. This has the advantage that some degrees of freedom that move the configurations away from moduli space can be treated perturbatively, unifying the essential low energy dynamics of all of these theories. We show that with this formalism one can compute the energies of strings in the BMN limit in the Klebanov-Witten theory from field theory considerations, matching the functional form of results found using AdS geometry. This paper also presents various other technical results for the semiclassical treatment of superconformal field theories.Comment: 52 pages, JHEP3 styl

Facilitators of and barriers to lifestyle support and eHealth solutions: interview study among health care professionals working in cardiac care

Background: Cardiovascular diseases (CVDs) pose a significant health threat and reduce both people's life expectancy and quality of life. Healthy living is a key component in the effective prevention and treatment of CVD. However, health care professionals (HCPs) experience difficulties in supporting lifestyle changes among their patients. eHealth can provide a solution to these barriers.Objective: This study aims to provide insights into the factors HCPs find important in the support of patients with CVD in the uptake of and adherence to a healthy lifestyle and the perceived facilitators of and barriers to using eHealth to provide lifestyle support to patients with CVD.Methods: In-depth interviews were conducted with 16 Dutch HCPs specializing in lifestyle support in cardiac care.Results: We identified 13 themes, of which the first 12 concerned lifestyle support in general and were related to intervention, patient, or health care. Throughout these themes, the use of eHealth reoccurred as a potential facilitator of or solution to barriers to lifestyle support. Our final theme specifically concerned barriers to the adoption and usability of eHealth.Conclusions: HCPs do recognize the potential advantages of eHealth while experiencing barriers to using digital tools. Incorporating their needs and values in the development of lifestyle support programs, especially eHealth, could increase their use and lead to a more widespread adoption of eHealth into health care.Cardiolog