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Dynamic Modelling, Simulation, and Sensitive Analysis of Lead Removal in a Fixed-Bed Adsorption Column using Waste-Based Materials
Get PDFThis study focuses on dynamic modelling and numerical simulation of lead removal from contaminated water using a fixed-bed adsorption column packed with waste-based
adsorbents. The pressing need for efficient and sustainable water treatment methods, particularly for heavy metal removal, underscores the significance of this research. Lead contamination in water sources poses severe health risks, necessitating the development of effective removal
strategies. The present investigation centres on a comprehensive mathematical model that considers critical parameters, including the column's physical dimensions, flow rate, initial lead concentration, adsorption rate constant, and adsorbent density. This model is expressed as a
partial differential equation (PDE) describing the temporal and spatial evolution of lead concentration along the fixed-bed column. To solve the PDE, the method of lines, a powerful numerical technique that discretises the spatial domain and handles the resulting system of ordinary differential equations (ODEs) using an adaptive solver, is employed. Following that, the effect factors of the simulation process are evaluated by sensitive analysis approach. Simulations are conducted to elucidate the intricate dynamics of lead removal over time and
column height. The numerical approach enables the prediction of lead concentration profiles within the column at various time intervals, providing crucial insights into the behavior of the adsorption process
Enhancement of Big Data Security in Cloud Computing Using RSA Algorithm
Get PDFThe enhancement of big data security in cloud computing has become inevitable due to factors such as the volume, velocity, veracity, Value, and velocity of the big data. These enhancements of big data and cloud technologies have computing enabled a wide range of vulnerabilities in applications in organizational business environments leading to various attacks such as denial-of-service attacks, injection attacks, and Phishing among others. Deploying big data in cloud computing environments is a rapidly growing technology that significantly impacts organizations and provides benefits such as demand-driven access to computational services, a distorted version of infinite computing capacity, and assistance with demand-driven scaling up, scaling down, and scaling out. To secure cloud computing for big data processing, a variety of encryption techniques such as RSA, and AES can be applied. However, there are several vulnerabilities during processing. The paper aims to explore the enhancement of big data security in cloud computing using the RSA algorithm to improve the deployment and processing of the variety, volume, veracity, velocity and value of the data utilizing RSA encryptions. The novelty contribution of the paper is threefold: First, explore the current challenges and vulnerabilities in securing big data in cloud computing and how the RSA algorithm can be used to address them. Secondly, we implement the RSA algorithm in a cloud computing environment using the AWS cloud platform to secure big data to improve the performance and scalability of the RSA algorithm for big data security in cloud computing. We compare the RSA algorithm to other cryptographic algorithms in terms of its ability to enhance big data security in cloud computing. Finally, we recommend control mechanisms to improve security in the cloud platform. The results show that the RSA algorithm can be used to improve Cloud Security in a network environment
The impact of physical activity on household out-of-pocket medical expenditure among adults aged 45 and over in urban China: The mediating role of spousal health behaviour
Get PDFBackground: Increasing medical expenditure is viewed as one of the critical challenges in the context of population
ageing. Physical activity (PA), as a primary prevention strategy for promoting health, is considered as an
effective way to curb the excessive growth in medical expenditure. This study aimed to analyze the association
between PA and the household out-of-pocket medical expenditure (HOPME) among Chinese urban adults aged
45 and over, and to explore the mediating role of spousal health behaviour.
Methods: This study analyzed a nationally longitudinal survey: 2014–2018 China Family Panel Studies (CFPS).
Fixed effects regression model was applied to estimate the association between PA and annual HOPME. Sobel
model was utilized to test the mediating effect.
Results: (1) PA was negatively associated with the annual HOPME among urban resident aged 45 and over in
China. Exercising 1–5 times per week and maintaining the duration of each exercise session at 31–60 min were
effective in reducing annual HOPME. (2) Spousal PA played a significant mediating role in the relationship
between respondent’s PA and annual HOPME. (3) The negative association between the respondent’s PA and
HOPME were found among women and those aged between 45 and 65, so was the mediating effect of spouse’s
PA.
Conclusion: Individual PA not only directly reduces HOPME but also indirectly contributes to this reduction by
enhancing the PA levels of their spouses. To capitalize on these benefits, more actions should be taken to increase
the availability of PA facilities, enhance the public awareness of PA’s benefits, and encourage residents to
consistently engage in regular PA
An exploration of how specialist dementia nurses perceive and maintain the skills and competencies that frame their specialism: A qualitative survey
Get PDFBackground
UK policy for complex and long-term health conditions including dementia has recommended that specialist nursing intervention is offered across the trajectory of the condition, but there is a lack of agreement regarding the skills and competencies that specialist nurses are expected to possess. Admiral Nurses are the largest UK group of specialist dementia nurses.
Objective
To explore how Admiral Nurses met and were supported to meet competencies as defined in the Admiral Nurse Competency Framework, and to develop and maintain skills as dementia specialists.
Design
Cross-sectional, semi-structured survey.
Setting
Online national survey.
Participants
Admiral (specialist dementia) Nurses.
Methods
We co-designed our survey with Admiral Nurses; then invited Admiral Nurses to complete it in 2022-23 Data were analysed thematically.
Results
68 (20% of all Admiral Nurses) completed the survey; most were female (85.2%), from a white ethnic group (88.2%); they reported on average 24 years of nursing experience. We identified three themes in responses: 1. Having time and skills for meaningful support, explored how participants were resourced with time and skills to understand and address family carer client needs by active listening, tailoring person-centred support, and “walking alongside” families. 2. Partnering family carers, concerned how they co-designed interventions with family carers, learning from these collaborative partnerships where expertise was shared. 3. Practice and peer-based learning, explored how participants took responsibility for using available training, peer learning and self-reflection to develop their practice.
Conclusions
Admiral Nurse roles enabled respondents to develop as autonomous practitioners and to access resources that supported them to build and sustain their dementia specialist practice. Learning was practice based, through partnerships with family carer clients, peer support and self-directed learning. Specialist nursing models may help address the global health workforce emergency, through enabling creative practice development and valued roles that support retention of experienced nurses
Hyperacetylated histone H4 is a source of carbon contributing to lipid synthesis
Get PDFHistone modifications commonly integrate environmental cues with cellular metabolic outputs by affecting gene expression. However, chromatin modifications such as acetylation do not always correlate with transcription, pointing towards an alternative role of histone modifications in cellular metabolism. Using an approach that integrates mass spectrometry-based histone modification mapping and metabolomics with stable isotope tracers, we demonstrate that elevated lipids in acetyltransferase-depleted hepatocytes result from carbon atoms derived from deacetylation of hyperacetylated histone H4 flowing towards fatty acids. Consistently, enhanced lipid synthesis in acetyltransferase-depleted hepatocytes is dependent on histone deacetylases and acetyl-CoA synthetase ACSS2, but not on the substrate specificity of the acetyltransferases. Furthermore, we show that during diet-induced lipid synthesis the levels of hyperacetylated histone H4 decrease in hepatocytes and in mouse liver. In addition, overexpression of acetyltransferases can reverse diet-induced lipogenesis by blocking lipid droplet accumulation and maintaining the levels of hyperacetylated histone H4. Overall, these findings highlight hyperacetylated histones as a metabolite reservoir that can directly contribute carbon to lipid synthesis, constituting a novel function of chromatin in cellular metabolism
Mobile apps for health surveillance: Balancing public health needs with the privacy of personal data
Get PDFThe privacy of personal information is aimed at protecting human rights both under
the international human rights regime and the Saudi Arabian constitution and other statutes and
regulations, subject only to some exceptions that include the protection of public health. The
coronavirus disease 2019 (COVID-19) pandemic has brought about certain challenges that
necessitate strategies to augment the conventional surveillance of infectious diseases, contact
tracing, isolation, reporting and vaccination. Several governments institutions, and agencies
presently adopt mobile applications for collecting, analyzing, managing, and sharing critical
personal data of individuals infected with or exposed to COVID-19. While the benefits of
sharing private information for achieving public health needs may not be disputed, the risk of
breach of personal privacy is enormous. This had forced the national governments into a
dilemma of either succumbing to public health needs, strictly respecting and protecting the
privacy of individuals, or alternatively, balancing the two conflicting demands. There is a
massive body of literature on the security and privacy of such mobile applications, but none
has adequately explored and discussed public interest justifications under Saudi Arabian laws
for alleged privacy breaches. We examined the health surveillance mobile app technologies
currently in use in Saudi Arabia with the aim of determining the potential risks of data breaches
under extant data protection laws. The paper recommends, among others, that any potential
risk of breach to right to privacy of personal information under the law must be (justified by)
the public health needs to protect society during the COVID-19 pandemic
Biochar-Enhanced Carbon-Negative and Sustainable Cement Composites: A Scientometric Review
Get PDFThe increasing demand for cement, driven by global urbanization and infrastructure expansion, necessitates the adoption of sustainable alternatives as construction materials. Cement-based composites, a prevalent construction material, are known for their high carbon footprint. Consequently, exploring sustainable alternatives is urgently needed to mitigate the environmental impact of the construction sector by capturing carbon dioxide (CO₂). Utilizing biochar (BC) in cement-based composites—either as an additive, cement replacement, or aggregate replacement—could be a green approach to producing enhanced composites with CO₂ sequestration capabilities.
This review investigates BC-modified cement composites by performing a scientometric assessment of the Scopus database, supplemented by a thorough manual review. A scientometric analysis of Scopus-indexed publications (2010–2024) was conducted to highlight key research trends, including influential authors, frequently cited works, contributing countries, and institutions. The findings provide a comprehensive overview of the current state of BC research and applications in cement-based composites for sustainable construction.
The assessment revealed that the Construction and Building Materials journal was the most prolific source of publications (n = 34), followed by Gupta (n = 11) as the most prolific author, and China (n = 56) as the leading country in the field. Emerging areas for the use of BC in the construction sector for CO₂ sequestration and potential future directions are also highlighted. Additionally, the review discusses BC sources, production technologies, and characteristics, as well as the influence of BC inclusion on fresh properties, mechanical properties, durability characteristics, carbon capture capabilities, and the environmental impacts of modified cement-based composites.
Notably, BC addition to cement-based composites at 1%–2% levels can enhance mechanical performance. However, replacements beyond 5%–6% resulted in declines compared to non-modified composites. BC addition reduced the flow characteristics of modified composites due to its porous morphology and hydrophobic nature but demonstrated improved internal curing and reduced shrinkage. The microstructure of the cement-based composite was also enhanced through pore refinement, attributed to the filling ability of BC particles, which is related to their specific surface area and size.
Moreover, the carbon sequestration potential of BC can be exploited in cement-based composites to create low-carbon or carbon-negative building materials with improved mechanical and durability characteristics. This study highlights future directions for further research and large-scale implementation strategies for BC as a sustainable construction material.
Keywords:
biochar; biochar-based composites; scientometric analysis; mechanical properties; durability; carbon sequestration; sustainabilit
A Survey on AI-Driven Energy Optimization in Terrestrial Next Generation Radio Access Networks
Get PDFThis survey uncovers the tension between AI techniques designed for energy saving in
mobile networks and the energy demands those same techniques create. We compare modeling approaches
that estimate power usage cost of current commercial terrestrial next-generation radio access network
deployments. We then categorize emerging methods for reducing power usage by domain: time, frequency,
power, and spatial. Next, we conduct a timely review of studies that attempt to estimate the power usage
of the AI techniques themselves. We identify several gaps in the literature. Notably, real-world data for
the power consumption is difficult to source due to commercial sensitivity. Comparing methods to reduce
energy consumption is beyond challenging because of the diversity of system models and metrics. Crucially,
the energy cost of AI techniques is often overlooked, though some studies provide estimates of algorithmic
complexity or run-time. We find that extracting even rough estimates of the operational energy cost of AI
models and data processing pipelines is complex. Overall, we find the current literature hinders a meaningful
comparison between the energy savings from AI techniques and their associated energy costs. Finally,
we discuss future research opportunities to uncover the utility of AI for energy saving
Analysing the Swing Equation using MATLAB Simulink for Primary Resonance, Subharmonic Resonance and for the case of Quasiperiodicity.
Get PDFThe swing equation plays a significant role in the analysis of stability and frequency response various power systems and mechanical systems. MATLAB Simulink simulates and analyses different systems, including synchronous generators with various excitation methods. This research aims to study the swing equation by modelling the system in Simulink. Swing equation analysis can be applied to tackle power instabilities in the electrical grid, to avoid power outages by monitoring the small disturbances that occur within the system. This paper shows the time series, phase portraits, and Poincar´e maps generated using data from the simulated model. It highlights the occurrence of period doublings which lead to loss of synchronisation and the resulting instability in the system that descends into chaos when the variables are changed in the Simulink model. The integrity diagrams were also identified for primary resonance, subharmonic resonance, and quasiperiodicity, offering valuable information to understand the system’s nonlinear behaviour. Using the swing equation in MATLAB Simulink provides a robust tool for analysing, simulating, and optimising systems. Hence this study provides an enhanced understanding of the system’s behaviour in Simulink for primary resonance, subharmonic resonance and for the case of quasiperiodicity. Additionally, it validates the analytical and numerical findings from prior works by the same authors
Impact of Wetting and Drying Cycles on the Hydromechanical Properties of Soil and Implications on Slope Stability
Get PDFThe soil-based infrastructure is the backbone of the global economy, connecting people, enhancing quality of life, and promoting health and safety. However, its vulnerabilities are becoming apparent due to climate change, mainly through frequent wetting and drying (wd) cycles. Despite few studies in the past, research showing the stability of flood embankments in the long term, incorporating the impact of wetting and drying cycles on the hydromechanical characteristics of soil, is scarce. This study aimed to assess the impact of controlled wd cycles on the hydromechanical properties of clay and silty sand soils and its implications for the stability of a typical flood embankment. Volumetric changes were monitored during the wd cycles. The soil water characteristic curve (SWCC), saturated hydraulic conductivity (ksat), effective cohesion (c′), and effective angle of internal friction (ϕ′) were measured at 1 and 10 wd cycles. The results indicated that the 10 wd cycles decreased the saturated moisture content and resulted in a flatter SWCC compared to the 1 wd cycle for clayey soil. The ksat value was also significantly higher at 10 wd cycles than 1 wd cycle for clayey soil. An insignificant difference was found in both the SWCC and ksat at 1 and 10 wd cycles for silty sand soil. The ϕ′ value for the clayey soil decreased from 28.5 to 20.1 as the wd cycles increased from 1 to 10, while c′ remained unchanged at 10 kN/m2. On the other hand, for the silty sand soil, ϕ′ increased from 34.6 to 37.5 with an increase in wd cycles from 1 to 10, and c′ remained constant at 1 kN/m2. Numerical modelling of transient water flow coupled with a slope stability analysis revealed that the stability of a flood embankment depends on the evolution of soil hydromechanical properties due to wd cycles and the duration of flooding. These findings underscore the need for proactive measures to mitigate landslide risks in regions prone to frequent wd cycles, thereby ensuring the safety and resilience of slopes and associated infrastructure