Investigating the Influence of Confinement Stress and Concrete Type on the Performance of Precast Segmental Dry shear-keyed Joints

This investigative research delves into the correlation between dry joint ultimate load and varied applied confinement stress levels – low at 2 MPa, moderate at 4 MPa, and high at 6 MPa – within structural joints. The focus is on diverse configurations of shear key quantities (single, dual, and triple shear keys) within these joints. Additionally, an examination was conducted on the influence of concrete types –Normal Strength Concrete (NSC) rated at 30 MPa, High Strength Concrete (HSC) at 60 MPa, and Ultra-High Strength Concrete (UHSC) at 120 MPa – alongside the aforementioned confinement stress levels on load capacity. The findings underscore a consistent enhancement in load capacity with escalating concrete strength, notably observed with UHSC exhibiting substantial advancements, particularly under conditions of mild to moderate confinement stresses. The study uncovers a nuanced association between confinement stress and load capacity, with results diverging for HSC and UHSC under scenarios of heightened confinement stresses. Furthermore, an in-depth exploration is conducted into the impact of shear-keyed joint configurations on joint performance, underscoring the pivotal role of shear-key design in ensuring structural resilience. These discoveries furnish invaluable insights for fine-tuning structural performance by judiciously selecting concrete strengths and shear key configurations tailored to specific confinement stress circumstances

Knowledge and practice related to compliance with mass drug administration during the Egyptian national filariasis elimination program

Lymphatic filariasis (LF) has been targeted for global elimination by 2020. The primary tool for the program is mass drug administration (MDA) with antifilarial medications to reduce the source of microfilariae required for mosquito transmission of the parasite. This strategy requires high MDA compliance rates. Egypt initiated a national filariasis elimination program in 2000 that targeted approximately 2.7 million persons in 181 disease-endemic localities. This study assessed factors associated with MDA compliance in year three of the Egyptian LF elimination program. 2,859 subjects were interviewed in six villages. The surveyed compliance rate for MDA in these villages was 85.3% (95% confidence interval = 83.9–86.5%). Compliance with MDA was positively associated with LF knowledge scores, male sex, and older age. Adverse events reported by 18.4% of participants were mild and more common in females. This study has provided new information on factors associated with MDA compliance during Egypt's successful LF elimination program

The effect of compliance on the impact of mass drug administration for elimination of lymphatic filariasis in Egypt

We studied effects of compliance on the impact of mass drug administration (MDA) with diethylcarbamazine and albendazole for lymphatic filariasis (LF) in an Egyptian village. Baseline microfilaremia (mf) and filarial antigenemia rates were 11.5% and 19.0%, respectively. The MDA compliance rates were excellent (> 85%). However, individual compliance was highly variable; 7.4% of those surveyed after five rounds of MDA denied having ever taken the medications and 52.4% reported that they had taken all five doses. The mf and antigenemia rates were 0.2% and 2.7% in those who reported five doses of MDA and 8.3% and 13.8% in those who reported zero doses. There was no significant difference in residual infection rates among those who had taken two or more doses. These results underscore the importance of compliance for LF elimination programs based on MDA and suggest that two ingested doses of MDA are as effective as five doses for reducing filariasis infection rates

Coal and biomass co-pyrolysis in a fluidized-bed reactor: Numerical assessment of fuel type and blending conditions

Co-pyrolysis is one of the most promising options for using coal and biomass because coal is low in hydrogen and biomass can supplement the hydrogen content to make a more valuable and reactive product gas. The mixture of coal and biomass is prepared, with the mass ratio of biomass varying between 0 and 100%. Due to limitations in experimental methods, the data points measured in these studies are coarse and therefore, insufficient for kinetic energy analysis and model comparison. Therefore, a mathematical model has been proposed to combine a study of the influence of experimental parameters with different materials to understand better the effect of these parameters on pyrolysis with the rigorous control of experimental conditions in terms of precision and repeatability. The advantages of mathematical modelling co-pyrolysis make it possible to design a reaction scheme capable of describing this phenomenon and extracting kinetic parameters, making it possible to compare fuels, which can be used for the simulation of this process in thermal power plants. The experimental analysis of measured co-pyrolysis data was taken from literature work to validate the proposed model. The numerical model results are in good agreement with the experimental data for co-pyrolysis. The most significant degree of synergetic effects on the product yields was observed at 600 °C and a biomass blending ratio of 70 wt%. Furthermore, the improvement of char reactivity also identifies the synergies in co-pyrolysis

Rapid accelerated hemodialysis in children with end-stage renal disease: A randomized clinical trial

In rapid accelerated hemodialysis (R-AHD), blood partially recirculates from the venous (outflow) to the arterial (inflow) line through a recirculation line (R) to selectively increase the filter blood flow rate (BFR). R-AHD PR uses two blood pump segments at the patient segment of the arterial line and at (R). To determine the effectiveness of R-AHD with regard to increasing anticoagulation and dialysis efficiency, we studied ten children with end-stage renal disease in two stages: stage 1 with 10 routine heparin R-AHD, then 10 half-dose heparin R-AHD, then 145 routine heparin R-AHD sessions for 1 month and then routine heparin double needle hemodialysis (DNHD) for one month (control). In stage 2, we dialyzed the patients with 10 routine heparin-mixed AHD PR and DNHD sessions, then eight low-dose heparin R-AHD PR" sessions, then one of the children with 10 no-heparin R-AHD PR sessions and then 10 routine heparin DNHD sessions" (control). Signs of blood clotting and dialysis efficiency were monitored. Blood clots appeared in four out of 165 R-AHD 0 (one pump circuit) sessions but in none of the 28 R-AHD PR sessions. In stage 1, the mean urea reduction rate was 0.60, 0.60 and 0.70 for the R-AHD protocols, compared with 0.71 for the control (P >0.05). In stage 2, the arterial blood urea nitrogen was reduced by 0.66 ± 0.15 after an R-AHD PR period, compared with 0.79 ± 0.18 after a DNHD period (P = 0.059). In conclusion, R-AHD PR allowed successful low heparin and no heparin hemodialysis in children without increasing the patients′ BFR. However, the technique did not increase the efficiency of dialysis

Safety and efficacy of transcatheter left atrial appendage closure using the Watchman device in Egyptian patients with nonvalvular atrial fibrillation

Background: Atrial fibrillation (AF) is considered the major cause of stroke in the elderly. Alternative therapies to the anticoagulant therapy are warranted, particularly in patients who are ineligible or at high risk of bleeding. The left atrial appendage (LAA) is a prominent source of thrombi in nonvalvular AF, accounting for 90% of thrombi. As a result, surgical and transcatheter techniques have been explored to reduce the risk of stroke in patients with AF by occluding the LAA. Objectives: To assess the safety and efficacy of LAA closure in patients with nonvalvular atrial fibrillation (AF) ineligible for warfarin therapy. Methods: A prospective study that evaluated LAA closure with the Watchman device (Boston Scientific, Natick, MA; group A) in fifteen patients with nonvalvular AF and CHADS2 (congestive heart failure, hypertension, age ⩾75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score ⩾1, who were considered ineligible for warfarin therapy. The primary efficacy endpoint was the combined events of ischemic/hemorrhagic stroke, systemic embolism and cardiovascular/unexplained death during a period of six months follow-up. Results: Successful closure of the LAA using the Watchman device was achieved in 15 patients (100%). The mean age was found to be 67.9 ± 9 years with 40% of them being males. No device or procedure related adverse events were detected. The mean CHADS2 score was 2.4 ± 0.8, while the mean CHA2DS2-VASC score was 4.4 ± 1.0. After a mean period of 8 ± 2 months of follow-up, no device dislodgement or device-related thrombi were documented. The all-cause stroke (ischemic and hemorrhagic) and systemic embolism were 0%. The device and procedure related mortality was found to be 0%. Only one patient died after 8 months of device implantation from pneumonia. Conclusion: LAA closure with the Watchman device can be safely performed, and may be a reasonable alternative to consider for patients at high risk for stroke but with contraindications to systemic oral anticoagulation or with high risk of bleeding

Energy recovery system in small reverse osmosis desalination plant: Experimental and theoretical investigations

The shortage of potable water, especially in developing countries has attracted researchers to try and overcome this problem. Desalination is one of the most effective methods used to solve this problem. Among desalination techniques, Reverse Osmosis (RO) has higher priority than thermal desalination methods, on account of its comparatively limited energy consumption. Different methods were introduced to enhance the performance of RO desalination plants. This study focused on employing an Energy Recovery System (ERS) to enhance the performance of the small RO plant for remote areas. The unit capacity was 2.4 m3/day, occupied with two double-acting cylinders with their control elements working as an ERS. An experimental setup is used to verify the effectiveness of the proposed ERS. A simulation model is designed and implemented to enable changing system parameters of the plant. The different system pressure experimental and model results were exposed and compared. The obtained results showed good agreement between experimental and simulation model values. The effect of recovery ratio on the power saving is highlighted. The ERS saved power consumption by 80%. The cost analysis of the small RO desalination plant with and without ERS was evaluated and showed a significant reduction in total cost