178 research outputs found
The Effect of Deposition Time on Filtration Efficiency of Electrospun Nanofibre Water Filters
Growing concern over turbidity of river waters due to high presence of solid suspensions has encouraged the development of new type of efficient water filters. In this study, a new type of water filter was developed by incorporating electrospun nanofibres. The relationship between the amount of incorporated nanofibres in term of deposition time and filtration efficiency was studied. Nylon 6 solution at 20 wt.% concentration was electrospun onto standard glass fibre filters. A high voltage of 14 kV was supplied at the spinneret and electrospinning distance was set at 10 cm. Suspended solid retention test was conducted on the glass fibre filters using a vacuum filtration system based on BS EN 872 standard. The morphology of the filters was studied using scanning electron microscopy and ImageJ software. From the results, the suspended solid retention capability increased linearly with nanofibre deposition time. Due to small size of the nanofibres, the addition of nanofibre layer has increased the total porosity of the filter. Findings from this study could open up further understanding in new generation of water filters
Simulation of Robot Navigation for Hospitalâs Confined Space Areas Using Fuzzy Control
The atmospheric hazards that may be present in confined space pose a serious threat to human while carrying special task in the respective location. Among the areas that are considered as confined space are utility tunnel, boiler, storage tank, sewage lines, utility holes and underground electrical fault. This study is concerned with hospitalâs enclosed space areas which include mechanical room and medicine storage area. Currently, there is no specific technique to replace worker for a task such as navigation and collecting air sample in the confined space for monitoring the hazards. A mobile robot integrated with CCD camera can be used to manoeuvre through the environment and at the same time monitor the situation in confined space. This paper discusses simulation of robot navigation for hospitalâs confined space areas. Fuzzy control was implemented to allow the robot to perform semiautonomous obstacle avoidance in the simulated environment. The result shows that the robot was able to manoeuvre around without any collision
Preparation, Characterization, and Electrical Conductivity Investigation of Multi-walled Carbon Nanotube-filled Composite Nanofibres
There is a growing interest in carbon nanofibre materials especially for applications that require high surface area, excellent chemical inertness, and good electrical conductivity. However, in certain applications a much higher electric conductivity is required before one can take the full advantage of the nanofibre network. Therefore, incorporating superconductive materials such carbon nanotubes is thought to be a feasible approach to enhance the electrical properties of the carbon nanofibres. The objectives of this study were to prepare and characterize multi-walled carbon nanotube-filled composite nanofibres. Carbon nanofibres were produced via electrospinning technique using precursor solutions of polyacrylonitrile in dimethylformamide loaded with different amount of multi-walled carbon nanotubes (MWCNT). The electrospun fibre samples were then pyrolyzed in a nitrogen-filled laboratory tube furnace. Characterization process was performed using scanning electron microscope (SEM), transmission electron microscope (TEM), and four-point probe method. It was found that the incorporation of MWCNT into the carbon nanofibre structures could significantly increase the electric properties of the nanofibres. The composite nanofibres with 0.1 wt.% of MWCNT loading has the highest electrical conductivity of 155.90 S/cm compared to just 10.71 S/cm of the pure carbon nanofibres. However, the electrical conductivity of the composite fibres reduced drastically when higher weight percentages of MWCNT were used. This was caused by agglomeration of MWCNT causing premature percolation, and broken fibre network as evidenced by SEM and TEM examinations. The results obtained from this study may facilitate improvements in the development of superconductive high surface area materials for electronic applications
Efficacy of hypertonic saline versus isotonic saline among children with cystic fibrosis: A systematic review and meta-analysis
Background: Inhaled hypertonic saline (HS) reduces pulmonary exacerbations in patients with cystic fibrosis (CF) aged 6 or more years. However, the effectiveness of HS in improving clinical outcomes in younger children aged 6 or less years is not established. This study examines the efficacy of HS in younger CF patients.
Methods: Searches were conducted across three databases (Medline, Cochrane Central and EMBASE) from inception through July 2022. Randomized controlled trials assessing the impact of HS in younger CF patients were included. Trials involving only patients greater than 6 years or control group other than isotonic saline (IS) were excluded. Outcomes measured included lung clearance index (LCI), cystic fibrosis questionnaire (CFQ-R) score, spirometry measures, oxygen saturation, respiratory rate, height and weight. Outcomes were reported as mean differences (MDs) with 95% confidence intervals.
Results: Seven studies (n = 390 patients) were included in this review. HS significantly reduced the LCI (MD: -0.67; 95%CI, -1.05 to 0.29, P = 0.0006)
compared to IS. In addition, HS was associated with significant improvements in height (MD: 2.23; 95%CI, -0.00 to 4.46, P = 0.05) and CFQ-R (MD: 4.30; 95%CI, 0.65â7.95, P = 0.02), but not in oxygen saturation (MD: -0.15; 95%CI, -0.54 to 0.25, P = 0.47), respiratory rate (MD: -0.21; 95%CI, -2.19 to 1.77, P = 0.83) or weight (MD: 0.70; 95%CI, -0.47 to 1.87, P = 0.24). Furthermore, HS did not significantly improve spirometry measures, including FEV1 (MD: -0.11; 95%CI, -0.21 to 0.43, P = 0.51) and forced vital capacity (MD: 0.27; 95%CI, -0.49 to 1.04, P = 0.48), but significantly improved FEF25-75 (MD: 0.12; 95% CI, 0.05â0.20; P = 0.002).
Discussion: Treatment with HS in younger children with CF improves lung clearance, symptoms and quality of life. FEF25-75 may prove a more sensitive measure for assessing intervention related improvements in pediatric CF trials.
Conclusion: The findings support HS as a therapeutic method in CF-affected children
Robust control of a wind energy conversion system: FPGA real-time implementation
This study employs an FPGA board to implement a robust control technique for wind energy conversion systems (WECS). This approach facilitates extensive testing and validation of the control system across diverse wind conditions, utilizing the FPGA's parallel processing capabilities and advanced control algorithms. This method ensures robustness against nonlinearities and system uncertainties. FPGA-in-the-loop (FIL) testing provides precise and effective simulation results, enabling rapid prototyping and iterative modifications of control algorithms. The effectiveness of the robust control strategy is confirmed by FIL findings, demonstrating significant improvements in WECS stability and efficiency. Furthermore, the study highlights the strategy's potential to enhance WECS reliability and efficiency in real-world applications
Prevalence and correlates of autism spectrum disorder in Qatar: a national study
Background
Few epidemiological data on autism spectrum disorders (ASD) exist for Arabic countries. We conducted the first survey of ASD in Qatar, a population with high consanguinity level.
Methods
This crossâsectional survey was conducted from 2015 to 2018 in Qatar schoolâage children (N = 176,960) from national and immigrant families. Children diagnosed with ASD were identified through medical centers and special needs schools. Records were abstracted and supplemented by parental interviews. Additionally, children attending 93 schools were screened; ASD case status was confirmed in random samples of screenâpositive and screenânegative children. Prevalence was estimated after taking into account different sampling fractions and participation rates at each survey phase.
Results
One thousand three hundred and ninetyâthree children already diagnosed with ASD were identified. Among 9,074 school survey participants, 760 screenânegative children and 163 screenâpositive children were evaluated; 17 were confirmed to have ASD including five children newly diagnosed. Prevalence was 1.14% (95% CI: 0.89â1.46) among 6â to 11âyearâolds. ASD was reported in full siblings/extended relatives in 5.9% (95% CI: 0.042â0.080)/11.8% (95% CI: 0.095â0.146) families. Firstâdegree consanguinity in Qatari cases (45%) was comparable to known population levels. Among 844 ASD cases (mean age: 7.2 years; 81% male), most children experienced language delay (words: 75.1%; phrase speech: 91.4%), and 19.4% reported developmental regression. At the time of the survey, persisting deficits in expressive language (19.4%) and peer interactions (14.0%) were reported in conjunction with behavioral problems (ADHD: 30.2%; anxiety: 11.0%). In multivariate logistic regression, ASD severity was associated with parental consanguinity, gestational diabetes, delay in walking, and developmental regression.
Conclusions
ASD prevalence in Qatar is consistent with recent international studies. The methods employed in this study should help designing comparable surveys in the region. We estimated that 187,000 youths under age 20 have ASD in Gulf countries. This figure should assist in planning health and educational services for a young, fastâgrowing population.The study was supported by the Qatar National Research Fund. The sponsor had no role in the design and conduct of the study, or the collection, management, analysis, and interpretation of the data, or in the preparation, review, or approval of the manuscript, and in the decision to submit the manuscript for publication. The authors thank all the independent and private schools that have participated in the SCQ screening phase. The authors thank the Ministry of Public Health and the Ministry of Education for providing their team with the data required throughout the study. The authors would like to express our gratitude to the psychological services team at the Shafallah Center for Children with Disabilities, as well as Dr. Irshad Shafeullah and Dr. Zakariah Al-Sayed for their support in patient recruitment. The authors also thank our colleagues from QBRI: Dr. Hatem Al-Shanti for his assistance in patient phenotyping, and Mr. Yasser Al-Sarraj and Ms. Hamda AlMutawwa for their support with patient recruitment. The authors thank Dr. Hanaa Massoud for assisting with patient recruitment through the clinic at the Child Development Center in Rumailah Hospital. The authors would also like to express their appreciation to the QBRI administration team for their assistance with planning and logistics pertaining to research-related training sessions and research collaborator visits. Additionally, the authors would like to thank all of the special needs centers and clinics which collaborated with us to provide data needed for the high probability cases; Shafallah Center for Children with Disabilities, Hamad Medical Corporation, Child Development Center ? Rumailah Hospital, Child Development Center-Private, Renad Academy, Al-Tamakun school, Step by Step Center, Qatar Institute for Speech and Hearing, and Hope Center. The authors also thank the HBKU Sponsored Research Office for the support provided throughout the research funding period.?K.R. and the OHSU Biostatistics & Design Program was partially supported by the Oregon Clinical and Translational Research Institute (OCTRI) through OHSU Clinical & Translational Science Awards (CTSA UL1TR0002369) National Consortium. The authors are immensely grateful to the families and their children for their time and participation in any of the phases of the research. F.A. and E.F. designed the research plan. F.A., M.A., and E.F. applied for funding. F.A., H.A., S.E., I.G., M.T., M.A., M.K., N.A.A., M.A., A.H.S., and L.D. organized the data collection. F.A., H.A., S.E., and I.G. completed data entry and cleaning, and performed initial data analyses with M.A. E.F. performed data and statistical analyses. K.R. provided biostatistical advice. E.F., F.A., and I.G. wrote the manuscript. All authors reviewed and approved the manuscript. The authors have declared that they have no competing or potential conflicts of interest.Scopu
Analyze Of Process Parameter Variance In 19nm Wsi2/Tio2 NMOS Device Using 2k-Factorial Design
This project investigates and analyzes the impact of process parameter variance on the drive current (ION) and leakage current (IOFF) for 19nm WSi2/TiO2 NMOS device using 2k-factorial design. The four process parameter, namely halo implant dose, halo implant energy, source/drain (S/D) implant dose and S/D implant energy will be investigated and adjusted to improve the results. The simulated of the device was performed by using ATHENA module. Meanwhile the electrical characterization of the device was implemented by using ATLAS module. These two modules will be combined with 2kfactorial to aid design and optimize the process parameters. The most effective process parameter with respect ION and IOFF were chosen depending on the percentage of the factor effect on S/N ratio that indicates the relative power of factor to reduce variation. The most dominant or significant factors in S/N Ratio are pocket halo implant dose and S/D implant energy. Meanwhile, the values of ION and IOFF values for 19nm WSi2/SiO2 NMOS device after optimization approaches are 591.38 ”A/”m and 2.217 pA/”m respectively. The results obtained are meet the requirement of International Technology Roadmap Semiconductor (ITRS) 2013 prediction
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
CVD-MPFA full pressure support, coupled unstructured discrete fractureâmatrix Darcy-flux approximations
Two novel control-volume methods are presented for flow in fractured porous media, involving coupling the control-volume distributed multi-point flux approximation (CVD-MPFA (c.f. Edwards et al.)) constructed with full pressure support (FPS), to two types of discrete fracture-matrix approximation for flow simulation on unstructured grids; (i) involving hybrid grids and (ii) a lower dimensional fracture model. Flow is governed by Darcy's law together with mass conservation both in the rock matrix and in fractures, where large discontinuous permeability tensors can occur. Finite-volume FPS schemes are more robust than the earlier CVD-MPFA triangular pressure support (TPS) schemes for problems involving strongly anisotropic homogeneous and heterogeneous full-tensor permeability fields. We use a cell-centred hybrid-grid method, where fractures are represented by lower-dimensional interfaces between matrix grid cells in the physical mesh, and expanded to equi-dimensional cells in the computational domain. We present a simple procedure to form a consistent hybrid-grid locally for a dual-cell. We also propose a novel hybrid-grid for intersecting fractures, for the FPS method, which improves the condition number of the global linear system and permits larger time steps for tracer transport. The tracer flow transport equation is coupled with the pressure equation and the results provide flow parameter assessment of the fracture models. Transport results obtained via TPS and FPS hybrid-grid formulations are compared with corresponding results of fine-scale explicit equi-dimensional formulations. The results show that the hybrid-grid FPS method applies to general full-tensor fields and provides improved robust approximations compared to the hybrid-grid TPS method for fractured domains, for both weakly anisotropic permeability fields and in particular for very strong anisotropic full-tensor permeability fields where the TPS scheme exhibits spurious oscillations. The hybrid-grid FPS formulation is extended to compressible flow and the results demonstrate the method is also robust for transient flow. Furthermore, FPS is coupled with a lower-dimensional fracture model, where fractures are strictly lower-dimensional in the physical mesh. Comparisons of the hybrid-grid FPS method and the FPS lower-dimensional fracture model are presented for several cases of isotropic and strongly anisotropic fractured media which illustrate the benefits of the respective methods
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