Cementitious composites reinforced with polypropylene, nylon and polyacrylonitile fibres

This paper compares the adhesion strength between three polymeric fibres (polypropylene (PP), nylon66 (N66) and polyacrylonitrile (PAN)) embedded in a cement paste. The specimens were prepared at a water to cement ratio (w/c) of 0.5, and tested after 7, 14 and 28 curing days. It was found that although the adhesion between the polymeric fibres to the cement matrix is an important factor, the energy absorption capacity or energy dissipation ability of the fibres plays a more important role in the improvement of the cementitious composites fracture toughness. Scanning electron micrographs was used to characterize the fibres surface before and after the Pullout tests

Evaluation of adhesion in polymeric fibre reinforced cementitious composites

In this study adhesion of some polymeric fibres to a cement matrix was evaluated both by a theoretical and by an experimental approach. In common methods adhesion of the fibres to the cementitious materials is determined by pull-out test. This test evaluates the energy failure during the fibre drawing out. This paper analyzes the adhesion theory for fibre reinforced cementitious composites to separate the share of the chemical and mechanical adhesion expressing new parameters, which are effective in the adhesion behaviour. Explanations about how the different fibres, matrix properties, test factors and environmental conditions can affect the adhesion results are given. It was found that for fibre/cement composites the fracture energy due to the interfacial interactions is for several orders of magnitude smaller that the polymeric fibre losses function. By employing adhesion theory, fibre/cement interac- tions are better described by a simple relationship of their surface free energy. Determination of the loss function (energy dissipation) leads us to predict the fibre behaviour in the cement matrix and the selection of the appropriate reinforcement

Simultaneous lidar and airglow temperature measurements in the mesopause region

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94970/1/grl5512.pd

The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) Scoring: the Diagnostic and Potential Prognostic Role

BACKGROUND: Necrotizing fasciitis (NF) is a devastating soft tissue infection associated with potentially poor outcomes. The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score has been introduced as a diagnostic tool for NF. We aimed to evaluate the prognostic value of LRINEC scoring in NF patients. METHODS: A retrospective analysis was conducted for patients who were admitted with NF between 2000 and 2013. Based on LRINEC points, patients were classified into (Group 1: LRINEC /= 6). The 2 groups were analyzed and compared. Primary outcomes were hospital length of stay, septic shock and hospital death. RESULTS: A total of 294 NF cases were identified with a mean age 50.9 +/- 15 years. When compared to Group1, patients in Group 2 were 5 years older (p = 0.009), more likely to have diabetes mellitus (61 vs 41%, p \u3c 0.001), Pseudomonas aeruginosa infection (p = 0.004), greater Sequential Organ Failure Assessment (SOFA) score (11.5 +/- 3 vs 8 +/- 2, p = 0.001), and prolonged intensive care (median 7 vs 5 days) and hospital length of stay (22 vs 11 days, p = 0.001). Septic shock (37 vs. 15%, p = 0.001) and mortality (28.8 vs. 15.0%, p = 0.005) were also significantly higher in Group 2 patients. Using Receiver operating curve, cutoff LRINEC point for mortality was 8.5 with area under the curve of 0.64. Pearson correlation analysis showed a significant correlation between LRINEC and SOFA scorings (r = 0.51, p \u3c 0.002). DISCUSSION: Early diagnosis, simplified risk stratification and on-time management are vital to achieve better outcomes in patients with NF. CONCLUSIONS: Beside its diagnostic role, LRINEC scoring could predict worse hospital outcomes in patients with NF and simply identify the high-risk patients. However, further prospective studies are needed to support this finding

Unusual Presentation of a Rare Tumor of the Dorsal Surface of the Foot

Calcifying aponeurotic fibroma (CAF) was originally described by Keasbey in 1953 as juvenile aponeurotic fibroma, most commonly occurring in the palms of the hands and soles of the feet in children and adolescents. It usually presents as a firm, painless mass without preceding trauma. We report a case of this rare condition with an unusual presentation in a 60-year-old woman affecting the dorsal surface of the foot. It is a relatively benign condition with a good prognosis following complete surgical excision. It may have a slightly increased incidence in males. The accurate diagnosis is based only on histology but it is essential to differentiate it from other sinister lesions such as fibrosarcoma that may lead to amputation

Kovalevski exponents and integrability properties in class A homogeneous cosmological models

Qualitative approach to homogeneous anisotropic Bianchi class A models in terms of dynamical systems reveals a hierarchy of invariant manifolds. By calculating the Kovalevski Exponents according to Adler - van Moerbecke method we discuss how algebraic integrability property is distributed in this class of models. In particular we find that algebraic nonintegrability of vacuum Bianchi VII_0 model is inherited by more general Bianchi VIII and Bianchi IX vacuum types. Matter terms (cosmological constant, dust and radiation) in the Einstein equations typically generate irrational or complex Kovalevski exponents in class A homogeneous models thus introducing an element of nonintegrability even though the respective vacuum models are integrable.Comment: arxiv version is already officia

Responding to physical and psychological health impacts of disasters: Case study of the Iranian disaster rehabilitation plan Agir en réponse aux conséquences physiques et psychologiques des catastrophes naturelles: �tude de cas du plan de relèvement post-catastrophe en Iran

This paper describes the process of developing a national pre-disaster plan for physical health and psychological rehabilitation of disaster-stricken communities. Data gathered from a literature review and expert panel discussions informed the process of drawing up unified definitions of physical and psychological health rehabilitation, carrying out stakeholder and STEEP-V analyses, and assigning the responsible organization and the collaborative organizations for each task. The Ministry of Health and the Welfare Organization were selected as the two responsible organizations. Integrated management at all levels, and sharing information, education and funding, were identified as ways to improve stakeholders� participation and collaboration. A system is needed for evaluating the implementation of the disaster rehabilitation plan, using valid and reliable indicators. © 2016, World Health Organization. All rights reserved

Assessment of geostatistical and interpolation methods for mapping forest dieback intensity in Zagros forests

During recent years, oak decline has been widely spread across Brant’s oak (Quercus brantii Lindl.) stands in the Zagros Mountains, Western Iran, which caused large-area forest dieback in several sites. Mapping the intensity and spatial distribution of forest dieback is essential for developing management and control strategies. This study evaluated a range of geostatistical and interpolation methods to explore the spatial structure and provide areabased maps of the intensity of forest dieback across a representative test site - Ilam Province - that was severely affected by Oak decline. The geostatistical analysis provided in-depth measures of the spatial structure amongst the selective sampling units (120 quadratic sample plots of 1200 m2), which eventually resulted in an area-based maps of dieback intensity. The accuracy of the applied methods was assessed by mean error percentage (%ME), root mean squared error percentage (%RMSE) and coefficient of determination (R2). Results showed moderate spatial structure within the sampling units. Moreover, cokriging (associated with soil humidity and aspect as independent variables) approach resulted in the highest accuracy, followed by two other methods of kriging and Radial Basis Function. Results suggested that cokriging can accurately estimate the intensity of dieback and its spatial distribution in the study area. According to this, an average dieback intensity of 18.12 % was estimated within the study area

Determining the best form factor formula for Loblolly Pine (Pinus taeda L.) plantations at the age of 18, in Guilan- northern Iran

In order to determine the best form factor formula for Loblolly Pine (Pinus taeda L.) plantations in Talesh (Western Guilan province-Iran), a number of 110 trees were selected based on their distribution in diameter classes, from 12 to 34 cm (in a two- cm diameter interval). First, several quantitative factors including diameter at breast height, diameter at 0.65 m of height, and diameter at stump were measured using a diameter tape, just before the trees being felled. After cutting the trees, the heights and diameter from breast height up to the height where diameter is 5 cm was measured using a diameter tape in a two meter interval. Finally, diameter at 0.1, 0.3, 0.5, 0.7, and 0.9 meter of the total height was measured respectively. As a consequent, each tree's volume was precisely calculated as the real volume. Next, the real form factor was calculated and its average was statistically compared to the averages of Natural , Artificial , and Hohenadl?s form factors using pair sample T-test. Results showed that there is no significant difference between the averages of real and Hohenadl?s form factors (at = 0.01 level). Furthermore, the averages of real and artificial form factors were not significantly different. Hence, both artificial and Hohenadl?s form factors are capable to replace the real form factor of Loblolly Pine over the study area

Non-integrability of the mixmaster universe

We comment on an analysis by Contopoulos et al. which demonstrates that the governing six-dimensional Einstein equations for the mixmaster space-time metric pass the ARS or reduced Painlev\'{e} test. We note that this is the case irrespective of the value, $I$, of the generating Hamiltonian which is a constant of motion. For $I < 0$ we find numerous closed orbits with two unstable eigenvalues strongly indicating that there cannot exist two additional first integrals apart from the Hamiltonian and thus that the system, at least for this case, is very likely not integrable. In addition, we present numerical evidence that the average Lyapunov exponent nevertheless vanishes. The model is thus a very interesting example of a Hamiltonian dynamical system, which is likely non-integrable yet passes the reduced Painlev\'{e} test.Comment: 11 pages LaTeX in J.Phys.A style (ioplppt.sty) + 6 PostScript figures compressed and uuencoded with uufiles. Revised version to appear in J Phys.