1,204 research outputs found
Experimental investigation on the use of waste elastomeric polymers for bitumen modification
The study described in this paper focused on the possible use of waste products coming from the production of styrene-butadiene rubber (SBR) and polybutadiene rubber (PBR), as bitumen modifiers. Modified binders containing these products were prepared in the laboratory with different polymer dosages and were thereafter subjected to the evaluation of empirical and rheological properties. For comparative purposes, the study also considered SBR and PBR products of premium quality. Ageing effects were also taken into account by means of proper laboratory simulations. Obtained results indicated that the two types of polymer (SBR and PBR) have completely different effects on the rheology and expected performance of the resulting modified binders. In particular, while the two polymers showed similar effects in terms of resistance to permanent deformation, the SBR products proved to be superior from the viewpoint of fatigue resistance. However, only minor differences were found when comparing the effects produced by premium quality and waste polymers. As a result of the experimental findings, it was concluded that the use of waste SBR polymers can be an attractive solution for the production of affordable modified binders
Heat Transfer and Flow on the First Stage Blade Tip of a Power Generation Gas Turbine
A combined experimental and computational study has been performed to investigate the detailed distribution of convective heat transfer coefficients on the first stage blade tip surface for a geometry typical of large power generation turbines (>1OOMW). This paper is concerned with the numerical prediction of the tip surface heat transfer. Good comparison with the experimental measured distribution was achieved through accurate modeling of the most important features of the blade passage and heating arrangement as well as the details of experimental rig likely to affect the tip heat transfer. A sharp edge and a radiused edge tip were considered. The results using the radiused edge tip agreed better with the experimental data. This improved agreement was attributed to the absence of edge separation on the tip of the radiused edge blade
Sudden death due to association between NAFLD and cardiovascular changes in a 37-year-Old Man: A case report
Fatty liver disease (FLD) is the most prevalent form of liver disease worldwide. Overnutrition can induce nonalcoholic fatty liver disease (NAFLD), a spectrum of conditions ranging from simple steatosis or nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis and cirrhosis. Some of the epidemiological and pathological studies have also suggested an association between the presence of fatty liver and sudden death. A 37-year-old man was found dead when he was asleep in the bed at home. According to his family, he was single and a costermonger. He was not an athlete, and there was no history of any physical and mental disorder. He was not addicted and did not use any drugs or alcohol. The positive points, in this case, were: a large heart with mild coronary stenosis and steatohepatitis in autopsy and sudden death. Since steatohepatitis did not have any complication such as fat embolism, it can be concluded that the combination of steatohepatitis and cardiovascular disorder led to sudden unexpected death. Heart more than 450 gr is susceptible to arrhythmia, and fatty liver disease can cause cardiovascular changes. © 2016 Tehran University of Medical Sciences. All rights reserved
Співвідношення понять “складна система” та “складне середовище” у социальній філософії
Исследовано соотношение понятий «сложная система» и «сложная среда», являющихся актуальными в современном социально-философском знании. Обосновано, что в современных условиях развития общества, которые характеризуются изменчивостью, нелинейностью и сложностью, в социальной философии развивается новая исследовательская парадигма – синергетическая, которая позволяет не только по-новому представить системный подход, но и дает иную интерпретацию социальных явлений. На первый план выходит понятие «сложная среда», которое подчеркивает динамические характеристики социальной реальности, указывает на ее процессуальность, многомерность и неравновесность. Также позволяет представить социальную реальность как исходно “психомерную систему / среду”. В частности с позиций психосинергетики (И. В. Ершова-Бабенко) понимание целостности и сложности системы приобретает вид концептуальной модели «целое в целом / целое-в-целом». Показано также применение психосинергетической интерпретации позиции И. Пригожина о неравновесном фазовом переходе нового типа в смысловом поле социальной философии. Впервые использовано явление «неучтенный субъект / продукт» в отношении анализа социальной реальности.The relationship between the concepts of «complex system» and «complex environment», which are relevant in modern socio-philosophical knowledge, is investigated. It has been substantiated that in modern conditions of the development of society, which are characterized by variability, non-linearity and complexity, a new research paradigm develops in social philosophy, which allows not only to introduce a systemic approach, but also gives a different interpretation of social phenomena. As a result, the systematic approach has been complemented and, even to some extent, is supplanted by the emerging synergistic approach, which presents social reality as a process of continuous changes and phase transitions. The emerging new view on social reality as an unstable integrity has confirmed that it is necessary to study events and processes. In particular, from the standpoint of psychosynergy (I.V. Yershova-Babenko), an understanding of the integrity and complexity of the system takes the form of a conceptual model of the “whole as a whole / whole-in-whole”. Therefore, the concept of «complex system» in social philosophy can be replaced by the concept of «complex environment», which indicates that emphasizes the dynamic characteristics of social reality, indicates its procedurality and disequilibrium.Also there was an appeal to the subject of social reality, which is a person. Focusing on the person and his social activities allows us to consider social reality as a “psychodimensioned environment” (the term of I.V. Ershova-Babenko), implying that it develops and transforms as a result of human mental activity, group, community of people in different scales of space and time, as well as the scale of individual cultures and civilizations.The use of the psycho-synergetic interpretation of the position of I. Prigogine on the non-equilibrium phase transition of a new type in the semantic field of social philosophy is also shown. For the first time, the phenomenon of “unaccounted subject / product”, related to the analysis of social reality, was used.Досліджено співвідношення понять «складна система» і «складне середовище», що є актуальними у сучасному соціально-філософському знанні. Обґрунтовано, що в сучасних умовах розвитку суспільства, які характеризуються мінливістю, нелінійністю і складністю, в соціальній філософії розвивається нова дослідницька парадигма – синергетична, яка дозволяє не тільки по-новому представити системний підхід, а й дає іншу інтерпретацію соціальних явищ. На перший план виходить поняття «складне середовище», яке підкреслює динамічні характеристики соціальної реальності, вказує на її процесуальність, багатовимірність і нерівноважність. А також представляє соціальну реальність як «психомірну систему / середовище» за походженням. Зокрема, з позицій психосинергетики (І. В. Ершова-Бабенко) розуміння цілісності і складності системи набуває вигляду концептуальної моделі «ціле в цілому / ціле-в-цілому». Показано також доцільність застосування психосинергетиченої інтерпретації позиції І. Пригожина про нерівноважний фазовий перехід нового типу у смисловому полі соціальної філософії. Вперше використано явище «неврахований суб’єкт / продукт», що відноситься до аналізу соціальної реальності
Characteristics of traumatic brain injury among accident and falling down cases
Motor vehicle and falling down are responsible for the most number of traumatic injuries. This study aimed to compare the characteristics of traumatic brain injury among accident and falling down cases. In this analytical cross- sectional study, data were collected from the records of cadavers who died due to accident or falling down and referred to Kahrizak dissection hall, Tehran forensic medicine organization during 2013. A total of 237 subjects (183 (77.2) accident and 54 (22.8) falling down) with a mean age of 35.62 (SD=15.75) were evaluated. A number of 213 (89.9) were male. From accident group, scalp injury was seen in 146 (79.8), scalp abrasion in 122 (66.7), scalp laceration in 104 (56.8), sub skull bruising in 176 (96.3), skull fracture in 119 (65), hemorrhage in 166 (90.7), Subdural hemorrhage (SDH) in 155 (84.7), Subarachnoid hemorrhage (SAH) in 161 (88), Epidural hemorrhage (EDH) in 41 (22.4), contusion in 140 (76.5), and skull base fracture in 140 (76.5) of cases. In falling down group scalp injury was seen in 42 (77.8) cadavers, scalp abrasion in 38 (70.4), scalp laceration in 30 (55.6), sub skull bruising in 49 (90.7), skull fracture in 39 (72.2), Hemorrhage in 49 (90.7), SDH in 43 (79.6), SAH in 47 (87), EDH in 10 (18.5), contusion in 33 (61.1), and skull base fracture in 39 (72.2) of cases. There was no significant difference between these two groups (P Value> 0.05). Accident and falling down had no difference in terms of any injury or hemorrhage. © 2015 Tehran University of Medical Sciences. All rights reserved
Autoantibodies Status of Leishmanial Patients in Iraq
A total of 145 leishmaniasis Iraqi patients were collected from suspected cases and 30 healthy control. Based on skin smear examination and serum samples analysis, the patients were distributed into two clinical groups: 30 cutaneous leishmaniasis and 30 visceral leishmaniasis patients. The study was conducted for the detection of 17 types of antinuclear autoantibodies (ANA) in studied groups, 10 types including (anti-ds-DNA, anti-Nucleosome, anti-SmD1, anti-PCNA, anti-SS-A/Ro60kD, anti-SS-A/Ro52kD, anti-SS-B/La, anti-CENP-B, anti-Mi-2 and anti-Ku antibodies), showed significant differences (P?0.05), (P?0.01) in the two groups, while 7 types which were non-significant included (anti-histones, anti-ribosomal P0, anti-Scl70, anti-U1-snRNP, anti-AMA M2, anti-Jo1 and anti-PM-Scl antibodies). With respect to the Anti-cardiolipin IgG antibodies (aCL), it showed a significant increased level in the serum of VL patients (P?0.01) as compared with control group (8.123 vs. 1.959), also as compared with CL patients (8.123 vs. 2.402). As for CL patients, also there was a significant difference (P?0.01) (2.402 vs. 8.123) when compared with VL patients, but no significant variations (2.402 vs. 1.959) were observed in compare with control group. We conclude that Leishmaniasis in iraqi patients may be considered as a cause autoimmune diseases as in case of inflammatory myopathies (IM), and the pathgenesis of human myositis, especially in VL which contributes in the immunological alterations associated with muscle damage. Keywords: Leishmania species, autoantibodies, antinuclear antibodies, anticardiolipin
Site effects “on the rock”: the case of Castelvecchio Subequo (L’Aquila, central Italy)
The April 6, 2009 L’Aquila earthquake was responsible for an “anomalous”, relatively high degree of
damage (i.e. Is 7 MCS scale) at Castelvecchio Subequo (CS). Indeed, the village is located at source-to-site
distance of about 40 km, and it is surrounded by other inhabited centres to which considerably lower
intensities, i.e. Is 5-6, have been attributed. Moreover, the damage was irregularly distributed within CS,
being mainly concentrated in the uppermost portion of the old village. Geophysical investigations (ambient
seismic noise and weak ground motions analyses) revealed that site effects occurred at CS. Amplifications of
the ground motion, mainly striking NE-SW, have been detected at the uppermost portion of the carbonate
ridge on which the village is built. Geological/structural and geomechanical field surveys defined that the CS
ridge is affected by sets of fractures, joints and shear planes – mainly roughly NW-SE and N-S trending –
that are related to the deformation zone of the Subequana valley fault system and to transfer faults linking
northward the mentioned tectonic feature with the Middle Aterno Valley fault system. In particular, our
investigations highlight that seismic amplifications occur where joints set NW-SE trending are open. On the
other hand, no amplification is seen in portions of the ridge where the bedrock is densely fractured but no
open joints occur. The fracture opening seems related to the toppling tendency of the bedrock slabs, owing to
the local geomorphic setting. These investigations suggest that the detected amplification of the ground
motion is probably related to the polarization of the seismic waves along the Castelvecchio Subequo ridge,
with the consequent oscillation of the rock slabs perpendicularly to the fractures azimuth
Scanned Imaging Techniques for Surface NDE
A phase sensitive laser probe in which the focussed spot is small, as compared with the acoustic wavelength, is capable of measuring the complex distributions of a SAW field along prescribed scan lines. Using the probe, it is possible, on a defect free sample, to measure the SAW velocity surface with an accuracy of a few parts in 105. Such accuracy suggests that the technique is sufficiently sensitive to detect small changes in surface characteristics; the presence of a defect is revealed by perturbations in the relationship between various scans. The scattered radiation patterns from a surface crack irradiated by acoustic surface waves can be utilised to determine the defect size and location with improved accuracy. Results on deliberate and real cracks are presented
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