301 research outputs found
Community Health Nursing in Saudi Arabia: Practices and Learning Needs
Get PDFKhalid Abdullah Aljohani Nursing College, Taibah University, Madinah, Saudi ArabiaCorrespondence: Khalid Abdullah Aljohani, Email [email protected]: This study investigated the daily practices of community nurses working in Primary Health Care Centers (PHCCs) and their learning needs.Participants and Methods: This descriptive cross-sectional correlational study was guided by the eight sections of the Canadian Community Health Nursing Standards of Practice 2019 expressing daily clinical activities and learning needs based on a five-point Likert scale. Participants were recruited from three Saudi Arabian cities. Descriptive data were processed regarding mean and Confidence Intervals for items, subscales, and the entire instrument. Comparisons for subgroups’ mean scores were assessed using one-way ANOVA followed by a Tukey HSD pairwise comparison.Results: 318 nurses participated in the study (75.5% response rate). The top practiced nursing activities were health education and supporting those who are unable to take action for themselves. On the other hand, the least practiced were participating in research invitations and research groups. Participants expressed their learning needs in utilizing health education theories and strategies and using Health informatics to support optimum nursing care.Conclusion: Saudi Arabia has a young community health nursing taskforce that needs to upgrade its knowledge and skills to match international standards. Understanding the real-life activities and learning needs of community health nurses in comparison to international standards will help health policymakers support the optimal contribution of nursing to patients outcomes and healthcare system utilization.Keywords: community health nursing, Saudi Arabia, learning needs, nursing practic
Joint decoding and estimation of spatio-temporally correlated binary sources
No full textIn the context of distributed joint source-channelcoding, we conceive a joint decoding and estimation scheme forbinary Markov sources exhibiting spatio-temporal correlation.The proposed scheme is designed based on the serial concatenation of a trellis coded modulation (TCM) scheme and a unityrate code. The symbol-based maximum a posteriori algorithm employed for TCM decoding is modified in order to exploit the source correlation. The estimation of both the spatial and temporal correlation parameters is performed jointly with the iterative decoding, hence allowing the estimated parameters to be updated after each iteration. Our simulation results reveal that when both the spatial and temporal correlation parameters are unknown, the proposed joint decoding and estimation scheme approaches the performance to the ideal system relying on perfectly known correlation parameters, therefore demonstrating the superiority of the proposed scheme
Autoignition characteristics and kinetic modeling of an oxygenated gasoline
No full textEthanol-containing gasoline offers a renewable and cleaner-burning alternative to traditional gasoline, thereby promoting a more sustainable and environmentally friendly transportation system. The shift towards ethanol-enhanced fuels aligns with global efforts to transition towards a low-carbon future in the transportation industry. This work explores ignition delay times of a certification oxygenated gasoline (Euro 6 E10) using a high-pressure shock tube (HPST) and a rapid compression machine (RCM) across a wide range of temperatures (658–1445 K), equivalence ratios (φ = 0.45, 1, 1.5), and pressures (20, 30, and 40 bar). The experimental results demonstrate that ethanol-containing gasolines exhibits similar reactivity as non-oxygenated gasolines at the high-temperature regime. However, at intermediate temperatures and up to the onset of NTC, gasolines with higher ethanol content display longer ignition delays compared to those with lower ethanol content and non-oxygenated gasolines, regardless of the octane characteristics of the fuel. At lower temperatures, Euro 6 E10 reactivity is influenced by the octane characteristics of the fuel. The measured data are compared to simulations using various surrogates, containing three to nine components, developed in the current work. A compact gasoline surrogate model is assembled, comprising of a comprehensive kinetic model (NUIGMech1.2) augmented with recent updates and appropriate sub-mechanisms from the literature. The proposed model is capable of reproducing the autoignition behavior of various oxygenated gasolines across a range of conditions. Sensitivity analyses were performed to elaborate the differences of various surrogates and to highlight the effect of fuel composition on oxygenated gasoline reactivity characteristics.Research reported in this publication was supported by the King Abdullah University of Science and Technology (KAUST). Khalid Aljohani acknowledges support from Prince Sattam bin Abdulaziz University under project number PSAU/2025/R/1446. We acknowledge that OpenAI's ChatGPT was used to support language refinement during the preparation of this manuscript
Mechanical Footstep power generator
Get PDFMechanical Footstep Power generator
By Author: Mohammed Aljohani
Abstract
Modern technology is focusing on newer and better sources of energy. Among the important areas are power generation methods since electricity has become part of our lives. Various researchers have conducted surveys to find out the feasibility of converting renewable kinetic energy into electricity. Some of the works done in the past emphasized the selection of suitable materials and power generation systems designs that appear complicated and expensive. To ensure there is cost efficiency and energy efficiency better power generation systems need to be embraced.
The footstep power generator is a system that utilizes the energy from people movement and transforms this movement into electricity. The system is efficient in the conversion of kinetic energy to electrical energy through placement of mechanical footstep power generator on the hind of footpaths. This project entails the conversion of the kinetic energy to electrical energy. The control mechanism carries the rack & pinion, D.C generator, battery and inverter control. The generator provides a simple and low-cost electricity production.
The mechanical footstep generator produces 1.56 kW for one down and up cycle without causing pollution which is an added advantage over other systems. Mechanical footstep power generator produces power on small scale therefore; the power generated applies to low power consuming gadgets. For instance, it can be used in lighting and running low power consuming devices.
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From Traditional Use to Modern Evidence: The Medicinal Chemistry of Antimalarials from Genus Artemisia
No full textWhile the use of plants in traditional medicine dates back to 1500 B.C., modern advancements led to the development of innovative therapeutic techniques. On the other hand, in the field of anti-infective agents, lack of efficacy and the onset of resistance stimulate the search for novel agents. Genus Artemisia is one of the most diverse among perennial plants with a variety of species, properties, and chemical components. The genus is known for its therapeutic values and, in particular, for its role in the origin of antimalarial agents derived from artemisinin. In this review, we aim to provide an updated overview of the evolution of natural and natureinspired compounds related to the genus Artemisia that have been proven, in vitro and in vivo, to possess antimalarial properties. An overview of the chemical composition and a description of the ethnopharmacological aspects will be presented, as well as an updated report on in vitro and in vivo evidence that allowed the translation of artemisinin and its derivatives from traditional chemistry into modern medicinal chemistry. The biological and structural properties will be discussed, also dedicating attention to the challenging tasks that still are open, such as the identification of optimal combination strategies, the routes of administration, and the full assessment of the mechanism of action
Self-directed learning readiness and learning styles among Taibah nursing students
No full textBackground: Advancements in nursing education programs stimulate the modifications in teaching and learning approaches to enhance nursing students' capabilities. Assessing students' learning styles and readiness to learn are essential components to guide such changes. Aim: This study aims to determine the nursing students' readiness for self-directed learning (SDL) and their learning styles. Methods: A cross-sectional descriptive, analytical research design was utilized in the present study. Two-hundred and thirteen nursing students studying two programs (regular and bridging) responded to the study instruments: demographics, SDL readiness (SDLR), and student-recorded responses to an online visual, aural/auditory, read/write, and kinesthetic (VARK) survey. Statistical analysis was performed using SPSS (version 20) to identify the descriptive and bivariate outcomes. Results: The response rate was 76%. Learning style results showed that aural, read-write, visual, and kinesthetic learning styles accounted for 19.7%, 8.5%, 6.6%, and 25.8% of participants, respectively. Desire for learning subscales were statistically significant for gender (t = 1.985, P = 0.048), academic level (F = 2.969, P = 0.033), and mode (t = 3.610, P = 0.001). The overall SDLR scale scores were significant for residence (t = 4.938, P = 0.001) and learning style (F = 5.197, P = 0.002). Conclusion: The study revealed that participants prefer to learn using unimodal VARK modalities, and the dominant learning style was kinesthetic. The participants' level of readiness for SDL and their self-control were high compared to the other SDLR subscales. The results showed a significant connection between the participants' learning styles and the variables of their readiness for SDL
The medicinal chemistry of Urtica dioica L.: from preliminary evidence to clinical studies supporting its neuroprotective activity
No full textUrtica dioica is a perennial herb from the family of Urticaceae that is commonly known as stinging nettle. This plant is widespread in Europe, Africa, America, and a part of Asia, as it adapts to different environments and climatic conditions. The leaves, stalk, and bark of U. dioica found applications in the field of nutrition, cosmetics, textile, pest control and pharmacology. In this connection, bioactive chemical constituents such as flavonoids, phenolic acids, amino acids, carotenoids, and fatty acids have been isolated from the plant. With this review, we aim at providing an updated and comprehensive overview of the contributions in literature reporting computational, in vitro, pre-clinical and clinical data supporting the therapeutic applications of U. dioica. Experimental evidence shows that U. dioica constituents and extracts can provide neuroprotective effects by acting through a combination of different molecular mechanisms, that are discussed in the review. These findings could lay the basis for the identification and design of more effective tools against neurodegenerative diseases
Advanced signal processing techniques for single-carrier Multi-user MIMO Wireless communications
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Role of Carboxylate ligands in the Synthesis of AuNPs: Size Control, Molecular Interaction and Catalytic Activity
No full textNanoparticles (NPs) are the basis of nanotechnology and finding
numerous applications in various fields such as health, electronics, environment, personal care products, transportation, and catalysis. To fulfill these functions, the nanoparticles must be synthesized, passivated to control their chemical reactivity, stabilized against aggregation and functionalized to achieve specific performances. The chemistry of metal nanoparticles especially that of noble metals (Gold, Platinum…) is a growing field. The nanoparticles have indeed different properties from those of the corresponding bulk material. These properties are largely influenced by several parameters; the most important are the size, shape, and the local environment of the nanoparticles.
One of the most common synthetic methods for the preparation of gold nanoparticles (AuNPs) is based on stabilization by citrate. Since it was reported first by Turkevich et al. in 1951, this synthetic scheme has been widely used, studied and a substantial amount of important information regarding this system has been reported in the literature. The most popular method developed by Frens for controlling the size of the noble gold nanoparticles based on citrate was achieved by varying the concentration of sodium citrate. Despite a large number of investigations focused on utilizing Cit-AuNPs, the structural details of citrate anions adsorbed on the AuNP surface are still unknown. It is known only that citrate anions “coordinate” to the metal surface by inner sphere complexation of the carboxylate groups and there are trace amounts of AuCl4−, Cl−, and OH− on the metal surface.
Moreover, it is generally accepted that the ligand shell morphology of Au nanoparticles can be partly responsible for important properties such as oxidation of carbon monoxide. The use of Au-NPs in heterogeneous catalysis started mostly with Haruta who discovered the effect of particle size on the activity for carbon monoxide oxidation at low temperature.
The structure of the citrate layer on the AuNP surface may be a key factor in gaining a more detailed understanding of nanoparticle formation and stabilization. This can be affecting the catalytic activity.
These thoughts invited us to systematically examine the role of sodium citrate as a stabilizer of gold nanoparticles, which is the main theme of this thesis. This research is focused on three main objectives, controlling the size of the gold nanoparticles based on citrate (and other carboxylate ligands Trisodium citrate dihydrate, Isocitric Acid, Citric acid, Trimesic acid, Succinic Acid, Phthalic acid, Disodium glutarate, Tartaric Acid, Sodium acetate, Acetic Acid and Formic Acid by varying the concentration of Gold/sodium citrate, investigating the interaction of the citrate layer on the AuNP surface, and testing the activity of the Au/TiO2 catalysts for the oxidation of carbon monoxide.
This thesis will be divided into five chapters.
In Chapter 1, a general literature study on the various applications and methods of synthesis of Au nanoparticles is described. Then we present the main synthetic pathways of Au nanoparticles we selected. A part of the bibliographic study was given to the use of Au nanoparticles in catalysis.
In Chapter 2, we give a brief description of the different experimental procedures and characterization techniques utilized over the course of the present work. The study of the size control and the interaction between gold nanoparticles and the stabilizer (carboxylate groups) was achieved by using various characterization techniques such as UV-visible spectroscopy, Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Nuclear Magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FTIR).
In Chapter 3, we discuss the synthesis and size control of Au nanoparticles by following the growth of these nanoparticles by UV-Visible spectroscopy and TEM. We then describe the effect of the concentrations and of various type of the stabilizer, and the post-synthesis treatment on gold nanoparticles size.
In Chapter 4, we focus on determining the nature of the interactions at molecular level between citrate (and other carboxylate-containing ligands) and AuNP in terms of the mode of coordination at the surface, and the formal oxidation state of Au when interacting with these negatively charged carboxylate ligands (i.e., LX- in the Green formalism). We achieve this by combining very advanced 13C CP/MAS, 23Na MAS and low-temperature SSNMR, high-resolution transmission electron microscopy (HRTEM) and density functional theory (DFT) calculations. A particular emphasis will be based on SS-NMR.
In Chapter 5, we study the influence of pretreatment of 1% Au/TiO2 catalysts on the resulting activity in the oxidation of carbon monoxide, the effect of the concentration and the type of the ligands on the catalytic activity. The catalysts were characterized by TPO, XRD, and TEM spectroscopy
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