Mechanical Properties of Low Densities Lightweight Foamed Concrete Strengthen with Raw Empty Fruit Bunch Fibre

Lightweight foamed concrete (LFC) is well known as a low-density concrete with a wide range of applications. LFC is good under compression but very poor in bending and tensile stresses, as it produces multiple microcracks and cannot withstand the additional stress induced by applied forces without supplementary reinforcing components especially in low densities LFC. Hence this study experimentally examined the effectiveness of the inclusion of oil palm empty fruit bunch (EFB) fibre in low densities lightweight foamed concrete (LFC) to enhance its mechanical properties. LFC specimens were reinforced with EFB fibre at volume fractions of 0.15%, 0.30%, 0.45%, and 0.60%. Three low densities LFC had been considered in this study namely 550 kg/m3, 750 kg/m3 and 950 kg/m3 with a constant cement-to-sand ratio of 1:1.5, and cement-to-water ratio of 0.4. The parameters assessed were compressive strength, bending strength and splitting tensile strength. The results revealed that the inclusion of 0.45% of EFB fibre in LFC helps to give the best results for the compressive, bending and splitting tensile strengths. EFB fibre acts as fillers bridging the gaps and micro-cracks within the LFC, resulting in the high strengths. The EFB fibre helped to avoid the promulgation of cracks in the plastic state in the cement matrix when the load was applied. Though, beyond the optimum level of EFB fibre addition, agglomeration, and the non-uniform dispersion of fibres was observed, which results in the lowered performance of the low densities LFC

New CPW-Fed Broadband Circularly Polarized Planar Monopole Antenna Based On A Couple Of Linked Symmetric Square Patches

A new broadband circularly polarized planar monopole antenna with coplanar waveguide feeding (CPW-fed) is proposed. This antenna consists of a couple of linked symmetric square patches (CLSSP), an asymmetric ground plane and two strips connected to the left ground plane by the CLSSP radiator and a straight strip. A broad impedance bandwidth (IBW) is achieved. Moreover, a broad axial ratio bandwidth (ARBW) is obtained by using an asymmetric ground plane and an inverted L-shaped strip. Simulation results demonstrate that IBW reaches 119% (1.56-6.18 GHz) and ARBW is 88.9% (2-5.2 GHz). The latter is completely overlapped by the simulated IBW. In addition, antenna performance is investigated by studying different parameters

Compact CPW-Fed Broadband Circularly Polarized Monopole Antenna With Inverted L-Shaped Strip And Asymmetric Ground Plane

The design of a coplanar waveguide-fed (CPW-fed) broadband circularly polarized printed monopole antenna is proposed. The antenna consists of a simple rectangular radiator monopole, an inverted L-shaped strip, a horizontal stub, and a modified asymmetric ground plane. Simulation results indicate that the impedance bandwidth (IBW) is 121% (1.575-6.4 GHz), and the axial ratio bandwidth (ARBW) is 64.3% (2.85-5.55 GHz). A parametric study is performed for verification. Results: indicate that the proposed antenna is suitable for different wireless communications systems

Pesticide use and opportunities of exposure among farmers and their families: cross-sectional studies 1998-2006 from Hebron governorate, occupied Palestinian territory

<p>Abstract</p> <p>Background</p> <p>Adverse health effects caused by pesticide exposure have been reported in occupied Palestinian territory and the world at large. The objective of this paper is to compare patterns of pesticide use in Beit-U'mmar village, West Bank, between 1998 and 2006.</p> <p>Methods</p> <p>We studied two populations in Beit-U'mmar village, comprised of: 1) 61 male farmers and their wives in 1998 and 2) 250 male farmers in 2006. Both populations completed a structured interview, which included questions about socio-demographic factors, types of farming tasks, as well as compounds, quantities, and handling of pesticides. Using the 1998 population as a reference, we applied generalized linear regression models (GLM) and 95% confidence intervals (CI) in order to estimate prevalence differences (PD) between the two populations.</p> <p>Results</p> <p>In 1998, farmers used 47 formulated pesticides on their crops. In 2006, 16 of these pesticides were still in use, including five internationally banned compounds. There were positive changes with less use of large quantities of pesticides (>40 units/year) (PD -51; CI -0.60, -0.43), in applying the recommended dosage of pesticides (PD +0.57; CI +0.48, +0.68) and complying with the safety period (PD +0.89; CI+0.83, +0.95). Changes also included farmers' habits while applying pesticides, such as less smoking (PD -0.20; CI-0.34, -0.07) and eating at the work place (PD -0.33; CI-0.47, -0.19). No significant changes were found from 1998 to 2006 regarding use of personal protective equipment, pesticide storage, farmers' habits after applying pesticides, and in using some highly hazardous pesticides.</p> <p>Conclusions</p> <p>The results were based on two cross-sectional surveys and should be interpreted with caution due to potential validity problems. The results of the study suggest some positive changes in the handling of pesticides amongst participants in 2006, which could be due to different policy interventions and regulations that were implemented after 1998. However, farm workers in Beit -U'mmar village are still at risk of health effects because of ongoing exposure to pesticides. To the best of our knowledge, no studies on long-term changes in pesticide use have been reported from developing countries.</p

Turner syndrome and sexual differentiation of the brain: implications for understanding male-biased neurodevelopmental disorders

Turner syndrome (TS) is one of the most common sex chromosome abnormalities. Affected individuals often show a unique pattern of cognitive strengths and weaknesses and are at increased risk for a number of other neurodevelopmental conditions, many of which are more common in typical males than typical females (e.g., autism and attention-deficit hyperactivity disorder). This phenotype may reflect gonadal steroid deficiency, haploinsufficiency of X chromosome genes, failure to express parentally imprinted genes, and the uncovering of X chromosome mutations. Understanding the contribution of these different mechanisms to outcome has the potential to improve clinical care for individuals with TS and to better our understanding of the differential vulnerability to and expression of neurodevelopmental disorders in males and females. In this paper, we review what is currently known about cognition and brain development in individuals with TS, discuss underlying mechanisms and their relevance to understanding male-biased neurodevelopmental conditions, and suggest directions for future research

The IceCube Neutrino Observatory Part III: Cosmic Rays

Papers on cosmic rays submitted to the 33nd International Cosmic Ray Conference (Rio de Janeiro 2013) by the IceCube Collaboration

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Fatal Granulomatous Amoebic Encephalitis Caused by Acanthamoeba in a Patient With Kidney Transplant: A Case Report Downloaded from

Granulomatous amoebic encephalitis (GAE) due to Acanthamoeba is almost a uniformly fatal infection in immunecompromised hosts despite multidrug combination therapy. We report a case of GAE in a female who received a deceased donor kidney graft. She was treated with a combination of miltefosine, pentamidine, sulfadiazine, fluconazole, flucytosine, and azithromycin. Keywords. Acanthamoeba; encephalitis; granulomatous amoebic; immunosuppression; transplantation. CASE REPORT A 64-year-old woman underwent deceased donor kidney transplantation due to diabetic nephropathy with uneventful recovery postoperatively and who had no known episodes of rejection. Seven months after transplantation, she presented with an episode of confusion that was attributed to a recurrent urinary tract infection and after treatment she was discharged home. A noncontrast computed tomography (CT) head scan and magnetic resonance imaging (MRI) of the brain at this time were normal. She returned 10 days later with intermittent confusion and word-finding difficulty. A physical examination was notable for a nontoxic-appearing woman with stable vital signs. She was awake and alert but oriented to person only. Speech was intact: language evaluation revealed expressive aphasia with impaired naming, intact repetition, and ability to follow simple commands. Cranial nerves and motor function were intact: deep tendon reflexes were 2+ and symmetric. She had downgoing toes bilaterally. Sensory function was intact except for decreased vibration bilaterally in the distal lower extremities. Cerebellar function was intact and gait was normal. Home transplant-related medications included tacrolimus, mycophenolate mofetil, prednisone, and valganciclovir for cytomegalovirus prophylaxis. Noncontrast CT head scan revealed hypodensity with mild mass effect in the left temporal lobe and insular cortex with the radiological differential diagnosis including encephalitis and acute stroke. An MRI of the brain with contrast showed diffuse, T2 hyperintense lesion of the left temporal lobe, and insular cortex. This was associated with patchy cytotoxic edema and focal, subtle enhancement with a tiny single focus of necrosis. There were multiple microhemorrhages within and remote from this region. Appearances were of atypical infectious encephalitis with microhemorrhages secondary to either a necrotizing vasculitis or arising from a central embolic source

A Broadband P-Shaped Circularly Polarized Monopole Antenna With A Single Parasitic Strip

A new broadband circular polarization (CP) monopole antenna with simple structure is proposed. The antenna consists of a P-shaped monopole and modified ground plane with rectangular stub, and results demonstrated that the 10 dB impedance bandwidth (ZBW) is 118.5% (1.6–6.25 GHz) and the 3 dB axial-ratio bandwidth (ARBW) is 104.4% (1.9–6.05 GHz). Procedures to improve the proposed antenna design and the CP mechanism analysis were performed. The performance of different parameters is presented. The advantages of the proposed antenna are broader ZBW and ARBW, simpler structure, and compact size

Potential of Biomass Frond Fiber on Mechanical Properties of Green Foamed Concrete

Currently, the cost of construction rises along with the ongoing impact on the environment, and it has led the researchers to the acceptance of biomass natural fibers, such as biomass frond fiber (BFF), for the improvement of the mechanical properties of cement-based materials. BFF is abundantly accessible, making it relatively pertinent as a reinforcing material in foamed concrete (FC). In addition, natural fiber-reinforced concrete has been progressively employed in construction for several decades to reduce the crack growth under the static load. This paper intends to experimentally investigate the effectiveness of the addition of BFF to FC to improve its mechanical properties. The FC samples were strengthened with BFF at the weight fractions of 0.12%, 0.24%, 0.36%, 0.48%, and 0.60%. This study used three FC densities: 600 kg/m3, 800 kg/m3, and 1000 kg/m3, with fixed constitutions with 0.45 and 1:1.5 cement-to-water and cement-to-sand ratios, respectively. The evaluated strength characteristics included bending, splitting tensile, and compressive strengths. The experimental outcomes indicated that adding 0.36% BFF to FC facilitates optimal splitting tensile, compressive, and bending strength results. BFF enhances material strength by filling the spaces, microcracks, and gaps inside the FC structure. The BFF helped to reduce crack spreading when the plastic state of the FC cementitious matrix was loaded. Furthermore, the optimum level of BFF inclusion and the accumulation and the non-uniform distribution of BFF were detected, which caused the lowering of the strengths of the FC significantly. Beyond the optimum level of BFF, the agglomeration and the non-uniform dispersion of the BFF were seen, which resulted in a drop in mechanical properties. The output from this research will give a better insight into the potential utilization of plant fiber in FC. It is of profound significance to guide the sustainable development and application of FC material and infrastructures