A Simple Heliodon System for Horizontal Placed Models

Most probably, all our buildings are affected by sunlight. Hence, the ignorance of the sun’s impact results in overheating, glare, and missed opportunities for the positive use of daylight, leading to wasted energy. Heliodon is considered to be a powerful tool that can aid students, professionals, building developers and users to better understand the relationship between the sun’s path and its effects on the architectural model(s). Most of the heliodons are relatively expensive and complex in operation. Thus, the need to design and build a simple and relatively inexpensive one emerged. It was proposed to work on this heliodon as a team project in the environmental control class “fall-2016”. The authors put the design concept and introduced a mathematical calculations table to be used with the physical heliodon, while nine students participated in the manufacturing process. The design concept is based on determining the sun’s position by converting the Altitude and Azimuth angels to their corresponding measurements on the (X, Y & Z) coordinates (in relation to the observer’s location). One light source can be moved on a set of graded tubes assembled in the shape of a wireframe box (thus the X, Y & Z distances could be measured) to simulate the sun’s position and its lighting conditions for any latitude, at any time for any chosen day

A Simple Heliodon System for Horizontal Placed Models

Most probably, all our buildings are affected by sunlight. Hence, the ignorance of the sun's impact results in overheating, glare, and missed opportunities for the positive use of daylight, leading to wasted energy. Heliodon is considered to be a powerful tool that can aid students, professionals, building developers and users to better understand the relationship between the sun's path and its effects on the architectural model(s). Most of the heliodons are relatively expensive and complex in operation. Thus, the need to design and build a simple and relatively inexpensive one emerged. It was proposed to work on this heliodon as a team project in the environmental control class “fall-2016”. The authors put the design concept and introduced a mathematical calculations table to be used with the physical heliodon, while nine students participated in the manufacturing process. The design concept is based on determining the sun's position by converting the Altitude and Azimuth angels to their corresponding measurements on the (X, Y & Z) coordinates (in relation to the observer's location). One light source can be moved on a set of graded tubes assembled in the shape of a wire frame box (thus the X, Y & Z distances could be measured) to simulate the sun's position and its lighting conditions for any latitude, at any time for any chosen day

Durability Performance of One-Part Geopolymer Versus Two-Part Geopolymer and Portland Cement Mortar

The investigations in the field of geopolymer binders indicated that this new material has a great potential to be an alternative to cement to reduce the carbon dioxide emissions. On the other hand, it was found that the traditional geopolymer has multiple defects, including the presence of viscous corrosive solutions. Researchers were interested in solving this problem and the traditional type was developed into one-part geopolymer and the need for solutions became in its composition and it became possible for this material to be an alternative to cement. But until now there are unexplained issues about one part geopolymers. In this instance, this study aims towards the investigated the fresh and hardened properties of one-part geopolymer mortar versus two-part geopolymer mortar and PC. The fresh and hardened properties that include workability, compressive strength, sulfate resistance, acid resistance and heat resistance were studied for samples cured at 30 OC and compared to PC samples cured by immersing in water. Moreover scanning electron microscopy (SEM) was investigated to support the test results. The results showed that, workability of one-part geopolymer mortar was enhanced by adding fly ash (FA). Moreover, the results revealed that higher compressive strength was achieved by adding ground granulated blast furnace slag (GGBS) and one-part geopolymer mortar exhibited superior resistance to sulfate, acid and heat by compared to PC. According to a SEM test one-part geopolymer mixes including GGBS were found to be more homogenous and dense than those containing F

Durability Performance of One-Part Geopolymer Versus Two-Part Geopolymer and Portland Cement Mortar

The investigations in the field of geopolymer binders indicated that this new material has a great potential to be an alternative to cement to reduce the carbon dioxide emissions. On the other hand, it was found that the traditional geopolymer has multiple defects, including the presence of viscous corrosive solutions. Researchers were interested in solving this problem and the traditional type was developed into one-part geopolymer and the need for solutions became in its composition and it became possible for this material to be an alternative to cement. But until now there are unexplained issues about one part geopolymers. In this instance, this study aims towards the investigated the fresh and hardened properties of one-part geopolymer mortar versus two-part geopolymer mortar and PC. The fresh and hardened properties that include workability, compressive strength, sulfate resistance, acid resistance and heat resistance were studied for samples cured at 30 OC and compared to PC samples cured by immersing in water. Moreover scanning electron microscopy (SEM) was investigated to support the test results. The results showed that, workability of one-part geopolymer mortar was enhanced by adding fly ash (FA). Moreover, the results revealed that higher compressive strength was achieved by adding ground granulated blast furnace slag (GGBS) and one-part geopolymer mortar exhibited superior resistance to sulfate, acid and heat by compared to PC. According to a SEM test one-part geopolymer mixes including GGBS were found to be more homogenous and dense than those containing F

ADHD desynchronizes brain activity during watching a distracted multi-talker conversation

Individuals with attention-deficit/hyperactivity disorder (ADHD) have difficulties navigating dynamic everyday situations that contain multiple sensory inputs that need to either be attended to or ignored. As conventional experimental tasks lack this type of everyday complexity, we administered a film-based multi-talker condition with auditory distractors in the background. ADHD-related aberrant brain responses to this naturalistic stimulus were identified using intersubject correlations (ISCs) in functional magnetic resonance imaging (fMRI) data collected from 51 adults with ADHD and 29 healthy controls. A novel permutation-based approach introducing studentized statistics and subject-wise voxel-level null-distributions revealed that several areas in cerebral attention networks and sensory cortices were desynchronized in participants with ADHD (n = 20) relative to healthy controls (n = 20). Specifically, desynchronization of the posterior parietal cortex occurred when irrelevant speech or music was presented in the background, but not when irrelevant white noise was presented, or when there were no distractors. We also show regionally distinct ISC signatures for inattention and impulsivity. Finally, post-scan recall of the film contents was associated with stronger ISCs in the default-mode network for the ADHD and in the dorsal attention network for healthy controls. The present study shows that ISCs can further our understanding of how a complex environment influences brain states in ADHD.Peer reviewe

ADHD desynchronizes brain activity during watching a distracted multi-talker conversation

Individuals with attention-deficit/hyperactivity disorder (ADHD) have difficulties navigating dynamic everyday situations that contain multiple sensory inputs that need to either be attended to or ignored. As conventional experimental tasks lack this type of everyday complexity, we administered a film-based multi-talker condition with auditory distractors in the background. ADHD-related aberrant brain responses to this naturalistic stimulus were identified using intersubject correlations (ISCs) in functional magnetic resonance imaging (fMRI) data collected from 51 adults with ADHD and 29 healthy controls. A novel permutation-based approach introducing studentized statistics and subject-wise voxel-level null-distributions revealed that several areas in cerebral attention networks and sensory cortices were desynchronized in participants with ADHD (n = 20) relative to healthy controls (n = 20). Specifically, desynchronization of the posterior parietal cortex occurred when irrelevant speech or music was presented in the background, but not when irrelevant white noise was presented, or when there were no distractors. We also show regionally distinct ISC signatures for inattention and impulsivity. Finally, post-scan recall of the film contents was associated with stronger ISCs in the default-mode network for the ADHD and in the dorsal attention network for healthy controls. The present study shows that ISCs can further our understanding of how a complex environment influences brain states in ADHD.</p

Avascular bone necrosis of the femoral head after renal transplantation: Is it avoidable?

Background: Avascular osteonecrosis (AVN) is a seriousosseous complication after renal transplantation (RT). Itsprevalence clearly decreased from 20% to 4% possiblydue to the use of calcinurin inhibitors (CNI), reduction ofsteroid doses and use of steroid free regimens. The aimof our study was to evaluate the frequency of AVNamong our kidney transplant recipients and to determinethe risk factors for its occurrence.Patients and methods: Among 1785 kidney transplantrecipients who received renal allografts between March1976 and December 2005, 40 patients (2.24%) developedAVN with a mean age of 31.3 10.2 years. Eightykidney transplant recipients without AVN were selectedto be a matched control group. The localization of AVNwas the femoral head in all cases.Results: AVN was diagnosed at a mean of 20.4 monthsafter transplantation. The following risk factors werestatistically significant; sirolimus-based regimen,hypercholesterolemia, overweight with body mass index(BMI)&gt;26 and those with HLA A9, HLA B35 and DRB15.Conclusions: We concluded that the proper managementof hypercholesterolemia, maintenance of ideal bodyweight as well as avoidance of sirolimus-basedimmunosuppressive regimen in genetically predisposedpatients may be an effective preventive strategy to avoidAVN

Experimental and analytical investigation of the lateral load response of confined masonry walls

This paper investigates the behavior of confined masonry walls subjected to lateral loads. Six full-scale wall assembles, consisting of a clay masonry panel, two confining columns and a tie beam, were tested under a combination of vertical load and monotonic pushover up to failure. Wall panels had various configurations, namely, solid and perforated walls with window and door openings, variable longitudinal and transverse reinforcement ratios for the confining elements and different brick types, namely, cored clay and solid concrete masonry units. Key experimental results showed that the walls in general experienced a shear failure at the end of the lightly reinforced confining elements after the failure of the diagonal struts formed in the brick wall due to transversal diagonal tension. Stepped bed joint cracks formed in the masonry panel either diagonally or around the perforations. A numerical model was built using the finite element method and was validated in light of the experimental results. The model showed acceptable correlation and was used to conduct a thorough parametric study on various design configurations. The conducted parametric study involved the assessment of the load/displacement response for walls with different aspect ratios, axial load ratios, number of confining elements as well as the size and orientation of perforations. It was found that the strength of the bricks and the number of confining elements play a significant role in increasing the walls’ ultimate resistance and displacement ductility