363 research outputs found

    Full-field pulsed magneto-photoelasticity – Experimental Implementation

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    This paper contains a description of the experimental procedure employed when using a pulsed-magneto-polariscope (PMP) and some initial full-field through-thickness measurements of the stress distribution present in samples containing 3D stresses. The instrument uses the theory of magneto-photoelasticity (MPE), which is an experimental stress analysis technique that involves the application of a magnetic field to a birefringent model within a polariscope. MPE was developed for through-thickness stress measurement where the integrated through-thickness birefringent measurement disguises the actual stress distribution. MPE is mainly used in toughened glass where the through-thickness distribution can reduce its overall strength and so its determination is important. To date MPE has been a single-point 2D through-thickness measurement and the analysis time is prohibitive for the investigation of an area which may contain high localised stresses. The pulsed-magneto-polariscope (PMP) has been designed to enable the application of full-field 3D MPE [ ]. Using a proof-of concept PMP several experimental measurements were made, these were promising and demonstrate the potential of the new instrument. Further development of this technique presents several exciting possibilities including a tool for the measurement of the distribution of principal stress difference seen in a general 3D model

    Prediction model for pile construction productivity rate utilizing the multiple linear regression technique

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    Productivity is a prevalent requirement in the bridge construction industry. The precision of productivity rate measurement is significantly influenced by the ability to recognize and implement the critical factors that impact the productivity rate. However, the significance of productivity in cost reduction and profit generation is fundamental to every construction industry. Bored piles are critical components in the foundation of transportation bridges. The productivity estimation processes for piles are influenced by a multitude of factors, leading to several challenges for estimators in terms of time and cost. Hence, the present study aims to diagnose these issues and evaluate the rate of productivity in pile construction through the utilization of the multiple linear regression (MLR) Technique. The data for this study was gathered via designated questionnaires, on-site interviews, and telephone inquiries to professionals affiliated with various construction firms. A selection of nine factors that have the greatest influence on the productivity of construction have been identified. These factors are considered autonomous variables that have an impact on the rate of pile productivity. The construction productivity rate, which is impacted by the influencing factors, is the dependent variable. An equal number of 84 questionnaire samples were utilized to construct each of the influencing factors incorporated in this model. The work measurement form was designed to collect real-time primary data from the construction site, six data samples for each factor were obtained from different bridge and overpass projects to verify the effectiveness and performance of the model. The study revealed that the multi-linear regression model has a high level of prediction for productivity, with an accuracy rate of 92.93%. Additionally, the correlation coefficient was determined to be 99%. The results indicated a robust correlation among the independent variables in the constructed model, and the predictions generated by the model matched what was observed

    Development of Parallel Auditory Thalamocortical Pathways for Two Different Behaviors

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    Auditory thalamocortical connections are organized as parallel pathways that originate in different divisions of the medial geniculate body (MGB). These pathways may be involved in different functions. Surprisingly little is known about the development of these connections. Here we review studies of the organization and development of auditory thalamocortical pathways in the pallid bat. The pallid bat depends primarily on passive hearing of prey-generated noise for localizing prey, while reserving echolocation for general orientation and obstacle avoidance. In the inferior colliculus (IC) and the auditory cortex, physiological studies show that noise and echolocation calls are processed in segregated regions. Injection of retrograde tracers in physiologically characterized cortical sites show that the ventral division of the MGB (MGBv) projects to the cortical region selective for noise. The cortical region selective for echolocation calls receives input from the suprageniculate (SG) nucleus in the dorsal MGB, but not from the MGBv. Taken together, these studies reveal parallel IC–MGB–cortex pathways involved in echolocation and passive listening. There is overlap of thalamocortical pathways during development. At 2-weeks postnatal, when the bat begins to exhibit adult-like hearing thresholds, the SG projects to both noise- and echolocation call-selective regions. The MGBv, as in adults, projects only to the noise-selective region. The connections become adult-like only after 2-months postnatal. These data suggest that parallel auditory thalamocortical pathways may segregate in an experience-dependent fashion, a hypothesis that remains to be tested in any species

    Troubles with Reality and Order through the Imagination in a World of Disbelief and Disorder: Wallace Stevens and Supreme Fiction

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    The voice of the intellect is a soft one but it does not rest until it has gained a hearing - Sigmu nd Freud There have been a lot of writers throughout history who praised or criticized the world s beauty and ways They all had their ideas and advice for humanity But America s most celebrated twentiethcentury poet Wallace Stevens did not just rain down his ideas in his writings but took them as his motto for life And he called the sum of his ideas Supreme Fiction This Supreme Fiction according to Stevens is a supreme level of poetry that cleanses the mind and soul of its readers and reduces the hardships they have to face in real life In other words Supreme Fiction is Stevens replacement for the idea of God Deeply influenced by the Nietzschean idea of the Death of God Stevens wants to create a replacement for God for people to find comfort in a world of disbelief and disorder in the twentieth centur

    Assessment of Pro Hepcidin and Related with Iron Profile on Hemodialysis Men Patients

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    Patients with renal failure in the final stages undergo the treatment by hemodialysis. Hemodialysis is used to reinstate the intracellular and extracellular fluid environment, by propagation of molecules in solution through a semipermeable membrane along an electrochemical concentration gradient. Blood catching in the dialysis machine and the recurrent phlebotomy may lead to losing about 1-3 g of iron per year. Prohepcidin hormone is an acute phase protein (type II) that plays a major role in the systemic iron irregularities as it is a mediator of anemia in inflammation and regulator of iron metabolism. This study aims to evaluate the effect of hemodialysis on iron hemostasis and its relationship with prohepcidin as an inflammatory marker. This study includes forty four adult male patients with end-stage renal failure (in pre and post –treated) by means of chronic hemodialysis-HD with mean age (53.27 ± 13.76 years). The following biochemical investigations have been studied: Prohepcidin, Iron, Ferritin, Transferrin, Total Iron-Binding Capacity (TIBC), The Unsaturated Total Iron Binding Capacity (UIBC), and transferrin saturation (TAST).Decrement of Prohepcidin level on hemodialysis patients in post dialysis with non-significantly compared to pre dialysis, while iron and ferritin was increment in post treated than pre- treated with non-significantly.Hemodialysis affects Prohepcidin levels as it was long duration and Glomerular Filtration rate GFR (cock croft equation) and prohepcidin level affect the iron profile related with the iron store depletion

    Study the Changes of Thyroid Hormones Levels Following Major Urological Surgery

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    This study was designed to evaluate the effect of major surgery on thyroid hormones and thyrotropin in patient undergoing major lower abdominal surgery. The study included fifty patients scheduled for elective major lower abdominal surgery, the serum levels of T3, T4 and TSH were determined one day preoperatively, intraoperative, one day postoperatively, two days postoperatively, and rT3 was determined one day preoperatively, and one day postoperatively. We observed that the levels of (T3, T4, TSH) increased significantly (P0.05). rT3 increased not significant (P>0.05) in one day postoperatively. It has been proposed these changes due to surgical stress that inhibits peripheral conversion of T4 to T3 by inhibiting peripheral 5'-deiodinase activity, also The absence of pituitary response to changes in serum levels of T3 and T4.According to the results of this study there is a transient abnormality in thyroid function tests in patient undergoing elective major surgery and this abnormality due to surgical stress

    Musculoskeletal Disorders and Association with Social Media Use Among University Students at the Quarantine Time Of COVID-19 Outbreak

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    Introduction: COVID-19 period was characterized by lockdown and quarantine, the aim of this cross-sectional analytical study is to investigate the effect of COVID-19 quarantine on social media use, and its association with musculoskeletal disorders (MSD) among university students. Methods: A cross sectional study was conducted among Al-Quds University students. 317 students (average age of 20.34 years) participated in this study. A self-designed questionnaire was used to collect data which was sent to students on social media using a simple random method in almost all academic year phases. Results: There was a statically significant increase in the following variables during quarantine compared to before (P0.05). There was no statistically significant difference in time spent on exercise before and during quarantine with average time before the quarantine of 0.80 hours to 0.7 hours during the quarantine (P>0.05). There was a statistically significant increase of severity of Musculoskeletal disorders (MSD) as measured by a scale of 0-10 during the quarantine (P<0.05) in terms of severity of headache (2 to 2, 78), neck pain (2.06 to 2.80), and back pain (2.17 to 3). This increase in the three dominant MSD was positively correlated with the hours of use of laptops, computers, and mobile phones, for communication and education (P<0.05). Statistically significant negative correlation was found in between night sleeping hours and severity of MSD reported by students (P<0.05). Age was correlated with less use of social media for leisure and with more exercise (P<0.05). StudentsConclusion: Quarantine increased the time of use of social media, and in turn increases the prevalence and severity of MSD among university

    The Reliability of Red Flags in Spinal Cord Compression

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    Background: Acute low back pain is a common cause for presentation to the emergency department (ED). Since benign etiologies account for 95% of cases, red flags are used to identify sinister causes that require prompt management. Objectives: We assessed the effectiveness of red flag signs used in the ED to identify spinal cord and cauda equine compression. Patients and Methods: It was a retrospective cohort study of 206 patients with acute back pain admitted from the ED. The presence or absence of the red flag symptoms was assessed against evidence of spinal cord or cauda equina compression on magnetic resonance imaging (MRI). Results: Overall, 32 (15.5%) patients had compression on MRI. Profound lower limb neurologic examination did not demonstrate a statistically significant association with this finding. The likelihood ratio (LR) for bowel and bladder dysfunction (sensitivity of 0.65 and specificity of 0.73) was 2.45. Saddle sensory disturbance (sensitivity of 0.27 and specificity of 0.87) had a LR of 2.11. When both symptoms were taken together (sensitivity of 0.27 and specificity of 0.92), they gave a LR of 3.46. Conclusions: The predictive value of the two statistically significant red flags only marginally raises the clinical suspicion of spinal cord or cauda equina compression. Effective risk stratification of patients presenting to the ED with acute back pain is crucial; however, this study did not support the use of these red flags in their current form

    A Study Of Corrosion Behavior Of Low Carbon Steel In Acidic And Basic Washing Water Of Crude Oil Solution At Different Temperatures

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    The corrosion behavior of low carbon steel in washing water of crude oil solution has been studied potentiostatically at five temperatures in the range ( 303 –343 )K, at pH ( 4 ) and at pH (4,6,7,9,11 ) at (343K)..The corrosion potential shifted to more negative values with increasing temperature and the corrosion current density increased with increasing temperature, the corrosion current density (icorr) decreased with increasing pH in the rang ( 4 – 7 ) and it increased with increasing pH in the rang ( 9 – 11 ) at ( 343 K ), while the corrosion potential generally variation with increasing pH in the rang (4-11)at(343K. From the general results for this study can be seen that thermodynamic and kinetic function were also calculated (?G, ?S, ?H and Ea
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