Low velocity impact response of rc beam with artificial polyethylene aggregate as concrete block infill

In structural design, an ideal situation for saving materials would be to reduce the weight of the structure without having to compromise on its strength and serviceability. A new lightweight composite reinforced concrete section was developed with a novel use of a lightweight concrete block as infill utilizing Artificial Polyethylene Aggregate (APEA and MAPEA). The concrete near the neutral axis acts as a stress transfer medium between the compression and tension zones. Partial replacement of the concrete near the neutral axis could create a reduction in weight and savings in the use of materials. In this experimental work, APEA and MAPEA were utilized as replacement for normal aggregates (NA) at percentages of 0%, 3%, 6%, and 9%, 12%, and 100% in the concrete mix. In this study, the concrete block infill uses the 100% MAPEA as a replacement for coarse aggregate. A total of sixteen beams were prepared measuring 170 mm × 250 mm × 1000 mm, in which four specimens were used as control samples (NRC) and twelve specimens were the reinforced concrete beam incorporated with different size of concrete block infill (RCAI) consisting of 100% MAPEA. All beams were tested with 100 kg steel weight dropped vertically from a height of 0.6 m and 1.54 m, which was equivalent to 3.5 m/s and 5.5 m/s respectively. Based on the experimental results, the impact force, displacement and crack patterns were affected by the impact load. For RCAI specimens, the impact force was larger but smaller displacement value was observed, compared to the NRC specimens. Furthermore, the width of the cracks generated in the RCAI specimens near the mid-span was less than that on the NRC specimen. All experiment results were validated against FEM. The transient impact force histories, displacement and crack patterns obtained from FEM matched reasonably well with the experiment results. The error reported a range of 1% to 15%. The results showed that the proposed use of concrete block infill produced desirable results under the impact loads. The main advantages of the concrete block infill that utilized MAPEA from waste plastic bags due to the weight reduction about 6% in the concrete beams

Approximate Expressions for the Magnetic Potential and Fields of Two-Dimensional, Asymmetrical Magnetic Recording Heads

Two-dimensional asymmetrical magnetic head are characterised by parallel inclination of the semi-infinite, inner gap walls, and where the gap length and head-to-underlayer separation are small compared to the other dimensions in the head. With head corner inclination, these structures contribute to reduction in the effective gap length of the head and therefore increase in the field magnitude and narrowing of the field distributions near the acute gap corner. Asymmetrical heads were therefore proposed for increasing the writing and readout resolutions in gapped magnetic head structures. There are currently no explicit or approximate analytical solutions for the potential and fields from two-dimensional asymmetrical magnetic heads. This paper is concerned with the detailed theoretical derivation of relatively simple closed-form approximations for the scalar magnetic potential and fields from twodimensional asymmetrical magnetic heads and their Fourier transforms, applicable to any arbitrary corner inclination angle. A general theory based on the translated Sine Fourier series is developed to model and study the reaction of a soft magnetic underlayer (SUL) on the surface potential of any magnetic head structure, and applied to the asymmetrical head. The approximate potential and field expressions derived in this paper demonstrated very good agreement with finite-element calculations of two-dimensional asymmetrical heads.Copyright © 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works

Invasive fungal infections and patients with malignancies in upper Egypt

The incidence of invasive fungal infections has increased considerably in recent years. The aim of this study was to present a suitable early diagnostic procedure in immune compromised patients, using detection of fungal infection of urine samples collected from 33 patients with malignancies (from 2-89 years old), during the period from December 2012 to February 2014, from South Egypt. Fifty-three fungal species representing 14 genera were collected during this investigation from urine samples on Sabouraoud’s Dextrose Chloramphenicol Agar (46 species and 12 genera) and Rose Bengal Chloramphenicol Agar media (41 species and 11 genera). Aspergillus (16 species), Penicillium (14 species), Yeasts (5 species) and Cladosporium (5 species) contributed the broadest spectra of species in all samples tested on two types of media used. Other species were represented by 13 species belonging to 10 genera. The results indicate that immune compromised patient is a suitable habitat for the growth and sporulation of different groups of fungi, both saprophytic and pathogenic. A variety of types of filamentous fungi were obtained from malignancies patients. Immunosuppressant patient’s exposure for fungal infection so should be in especial care from food, drinking and air. Published by the International journal of Microbiology and Mycology (IJMM

Various methods for retrofitting prestressed concrete members: A critical review

Structures of a building can get exposed to adverse conditions resulting from overloading situations, which would eventually contribute to massive building degradation. The choice to repair the building structures seems to be very costly. The possible step that could be taken is by implementing a method of reinforcing and strengthening the building structures. For the past years, strengthening methods by implementing various innovative technologies has been seen to become a modern scientific topic in the fields of environmental and civil engineering study. Previous related studies on the reinforcement of pre-stressed concrete beams (PSC) by adding different elements have been observed by past researchers. The tests were carried out to evaluate the shear and flexural capacities of the building structures after the mechanisms were installed. A large number of scholars have conducted such studies with different types of interacting factors. In this study, a review will be presented by analyzing various techniques that have been implemented by multiple researchers for strengthening pre-stressed concrete beams, as well as their shear and flexure performances of the beams

Flexural strengthening of the continuous unbonded post -tensioned HSC beams by precast SIFCON laminates

Slurry Infiltrated Fiber Concrete (SIFCON) is a cementitious composite with outstanding durability and mechanical characteristics. Accordingly, the current research studies the behavior of continuous unbonded post-tensioned HSC beams that were flexural strengthened with precast SIFCON laminates. Four prestressed concrete beams with dimensions (200x300) mm and 4300 mm length were fabricated have been strengthened with 30 mm thick precast SIFCON laminates gluing with epoxy and were tested to understand the influence of their strengthening with using the various length of the laminates. The results showed that the use of precast SIFCON laminates is an effective method in enhancing the capacity of load-carrying and stiffness of continuous unbonded post-tensioned HSC beams. Used various lengths of precast SIFCON laminates in hogging and sagging regions led to positively affected by delaying the first crack appearance time of the tested beams between (56.1%-60%), Increased the ultimate flexural capacity of the test beams (36.9%-43.6%), and improving in stiffness about (153.7%-243.6%). When comparing specimens unstrengthened and strengthened, the strengthening generally leads to a reduction in the crack width in central support and mid-span regions. In other words, the crack behavior was enhanced

Ultrasonography of fetal kidney length as the approach for estimation of gestational age in Sudanese

A true estimation of gestational age (GA) plays an important role in quality maternity care and scheduling the labor date. This study was to evaluate the  application of kidney length (KL) measurement to the determine GA between the 14th and 40th weeks and to compare its accuracy with that of other  fetal biometric indices. This study has been designed as a prospective descriptive cross-sectional study in Khartoum and Gezira states - Sudan. 389  Sudanese healthy pregnant women, age between 15 – 45 years were examined by ultrasound with normal and wellbeing fetuses. Linear regression  models for estimation of GA were derived from the biometric indices and kidney length. Also, stepwise regression models were constructed to detect the  best model for determining GA between 14 and 40 weeks. Comparisons were then made between the accuracy of these models in the determination of  GA. The equations derived from linear regression analysis when the individual variables were considered separately. Among the variable parameters  considered in this study, the most accurate was the kidney length with a standard error (SE) of (0.04) day, after that the biparietal diameter with (SE=0.10  day) and femur length, (SE=0.13 day). While the least accurate one was the abdominal circumference with an SE of 1.35 days. A significant correlation was  found between GA and KL (r=0.72, P<0.002). The Kidney length is the easy to identify and measure. It is the most accurate parameter for estimating  GA than other biometric indices in late 2nd and 3rd trimesters.&nbsp

Bis{2-[2-(1H-indol-3-yl)ethyl­imino­meth­yl]phenolato-κ2 N,O}nickel(II) N,N-dimethyl­formamide disolvate

The Ni atom in the title compound, [Ni(C17H15N2O)2]·2C3H7NO, lies on a twofold rotation axis. It is N,O-chelated by the deprotonated Schiff base 2-[2-(1H-indol-3-yl)ethyl­imino­meth­yl]phenolate ligand in a square-planar coordination environment. The mol­ecule is linked to a solvent mol­ecule by an indole–dimethyl­formamide N—H⋯O hydrogen bond

a collaboration among refugee newcomers, migrants, activists and anthropologists in Berlin

In 2015, Germany entered what would later become known as the ‘refugee crisis’. The Willkommenskultur (welcoming culture) trope gained political prominence and met with signifi cant challenges. In this article, we focus on a series of encounters in Berlin, bringing together refugee newcomers, migrants, activists and anthropologists. As we thought and wrote together about shared experiences, we discovered the limitations of the normative assumptions of refugee work. One aim of this article is to destabilise terms such as refugee, refugee work, success and failure with our engagements in the aftermath of the ‘crisis’. Refugee work is not exclusively humanitarian aid directed towards the alleviation of suff ering but includes being and doing together. Through productive failures and emergent lessons, the collaboration enhanced our understandings of social categories and the role of anthropology