Synthesis and optical properties of polyvinylidene difluoride nanocomposites comprising MoO3/g-C3N4

The present study describes the optical properties for prepared polymer nanocomposites of PVDF at different content of MoO3/g-C3N4. The structural properties of polymer films were analysed via XRD, FTIR and ESEM techniques. The XRD diffraction patterns of PVDF with different concentrations of MoO3/g-C3N4 have two characteristic peaks at 2 θ = 18.4° and 20.3° where first peak was assigned to α-phase, while last peak was attributed to β-phase. The ESEM micrographs of PVDF-MoO3/g-C3N4 nanocomposites have shown smooth surface topography. According to the UV–visible absorption spectra, the UV absorption of PVDF was increased when adding MoO3/g-C3N4 nanoparticles where distinct peak was appeared in the UV region at 310 nm and its edges become more intense and moved towards higher wavelength after MoO3/g-C3N4 incorporation. The optical values of (Edir) and (Eind) energies have decreased with increasing the nanoparticle composites content. The optical band gap energy (Eopt) was decreasing from 5.66 eV to 4.56 eV as increasing the content of MoO3/g-C3N4. The refractive index (n) was increased with increasing the concentration of MoO3/g-C3N4 in nanocomposites samples, except for the sample with 0.25 wt%. The distinctive optical characteristics of PVDF-MoO3/g-C3N4 qualify such polymer nanocomposites for optoelectronic applications

Linear and nonlinear optical investigations of polyvinyl chloride modified La2O3 nanocomposite films

In the present work, we report the effect and improvement of PVC polymer blend nanocomposites performance with addition of lanthanum oxide (La2O3) nanofiller. The structural properties of the samples were studied using different characterization techniques such as XRD, FTIR, Ramman and SEM. The X-ray diffraction peaks of La2O3 are with agreement with the pure hexagonal phase. The La2O3 sample was found to have crystallites size with an average about 15 nm. XRD, FTIR and SEM analysis confirmed the interaction of PVC/La2O3 polymer nanocomposites. The obtained band gaps of PVC/La2O3 polymer nanocomposites decreased (5.72 – 5.0 eV) upon increasing the nanofiller content. The obtained values of single oscillator energy (E0) showed a decrease (5.88 – 3.28 eV) while dispersion energy (Ed) increases (5.64 – 7.20 eV) upon increasing the concentration of La2O3. The estimated values of static refractive index (n0) showed an increase (1.40 – 1.79) upon increasing the percentage of La2O3. Moreover, the nonlinear refractive index (n2) value was changed from 1.56 10−13 to 33.56 x 10−13 esu. Finally, the addition of La2O3 nanofillers increase the polarizability of the polymer molecules and hence the nonlinear refractive index

Squint Among Adult Population in Hail City, Saudi Arabia

Background: Strabismus, also known as crossed eyes, is a condition in which the eyes do not properly align with each other when looking at an object. If present during a large part of childhood, it may result in amblyopia. If onset is during adulthood, it is more likely to result in double vision. Objective: The aim of the study was to estimate the prevalence of squint, types and treatment characteristics in the studied adults in Hail city, Saudi Arabia. Methods: A cross-sectional study conducted in Hail city, Saudi Arabia. The study included 294 participants; 95 male and 199 female adults aged >20 years. The study period was from 1 January to 30 April 2018. Data collected by personal interview using a pre-designed questionnaire, which distributed among the participants to be self-reported. Results: The prevalence of squint among the studied population was 9.9%. it was more common in females than males. Squint was right sided in 24.1% of the cases, left sided in 51.7% and in both eyes in 24.1% of the studied cases. About half (44.8%) of cases had inward squint (esotropia) and 10.3% outward squint (exsotropia), 24.1% of the cases had Intermittent squint and 6.9% had permanent squint. Most (55.2%) of squint cases use glasses and 34.5% of cases squint affected their visual acuity. In 6.9%, squint causes psychological troubles. As regards treatment, 20.7% received medical treatment and 17.2% received surgical treatment but 62.1% do not seek medical care. Only 10.3% of cases completely cured and 13.8% had recurrence. There was insignificant relation with age, sex, education, squint in parents, chronic diseases, consanguinity or hereditary diseases (P>0.05). Conclusion: in this study, the prevalence of squint in the adult participants in Hail city, Saudi Arabia was 9.9% but 62.1% do not seek medical care. After treatment, only 10.3% of cases completely cured and 13.8% had recurrence. Health education of the public about importance of early treatment is highly recommended. Keywords: Squint; strabismus; adult population; prevalence; types; Hail; Saudi Arabia

Data Equity: Foundational Concepts for Generative AI

This briefing paper focuses on data equity within foundation models, both in terms of the impact of Generative AI (genAI) on society and on the further development of genAI tools. GenAI promises immense potential to drive digital and social innovation, such as improving efficiency, enhancing creativity and augmenting existing data. GenAI has the potential to democratize access and usage of technologies. However, left unchecked, it could deepen inequities. With the advent of genAI significantly increasing the rate at which AI is deployed and developed, exploring frameworks for data equity is more urgent than ever. The goals of the briefing paper are threefold: to establish a shared vocabulary to facilitate collaboration and dialogue; to scope initial concerns to establish a framework for inquiry on which stakeholders can focus; and to shape future development of promising technologies. The paper represents a first step in exploring and promoting data equity in the context of genAI. The proposed definitions, framework and recommendations are intended to proactively shape the development of promising genAI technologies

Optimised power harvesting by controlling the pressure applied to molecular junctions

A major potential advantage of creating thermoelectric devices using self-assembled molecular layers is their mechanical flexibility. Previous reports have discussed the advantage of this flexibility from the perspective of facile skin attachment and the ability to avoid mechanical deformation. In this work, we demonstrate that the thermoelectric properties of such molecular devices can be controlled by taking advantage of their mechanical flexibility. The thermoelectric properties of self-assembled monolayers (SAMs) fabricated from thiol terminated molecules were measured with a modified AFM system, and the conformation of the SAMs was controlled by regulating the loading force between the organic thin film and the probe, which changes the tilt angle at the metal-molecule interface. We tracked the thermopower shift vs. the tilt angle of the SAM and showed that changes in both the electrical conductivity and Seebeck coefficient combine to optimize the power factor at a specific angle. This optimization of thermoelectric performance via applied pressure is confirmed through the use of theoretical calculations and is expected to be a general method for optimising the power factor of SAMs

Assessing Bone Mineral Density in Sickle Cell Disease Patients and linking it to Admission Rates: A Prospective Uni-center Study

INTRODUCTION: Sickle cell disease (SCD) is an inherited autosomal recessive disorder with bone mineral density (BMD) as a common clinical manifestation of SCD. With a prevalence of 2.6%, Saudi Arabia is among the highest incidence of SCD worldwide. The purpose of this research was to examine how SCD evolves and how it affects bone density in Saudi patients from an Eastern Province tertiary hospital. METHODS: This was an observational prospective study conducted in the tertiary care hospital among 119 SCD patients. Patients were divided into two groups: Group A – severe SCD patients requiring hospital care ≥3/year; and Group B included patients with a smooth course of SCD who did not require frequent hospitalization (<3 hospitalizations per year), with a milder course of the disease. Analysis was based on the frequency of hospitalizations with pain crises and measuring BMD. RESULTS: Of 119 patients, 73.1% had low bone density. Compared to the femur (47.9%), the spine (62.2%) had a higher prevalence of low bone density. The prevalence of low BMD did not significantly differ between the two groups (64.8 vs. 79.9%, P = 0.081). Patients with more frequent hospital visits had significantly higher Mg concentrations (2.30 vs. 0.84, P = 0.001), higher gamma-glutamyl transferase (59.44 vs. 39.49, P = 0.030), and significantly lower 25-hydroxy Vitamin D (34.82 vs. 49.48, P = 0.004). CONCLUSIONS: Patients with SCD had a generally higher prevalence of low BMD. Further research is needed to answer the proposed debate about the accuracy of DXA scanning in patients with SCD

A principled approach for engineering privacy by design

Privacy is a multi-faceted concept that has several aspects. It is subjective in nature, not least because it is influenced by a variety of factors, including societal demands, which evolve over time, and technological developments. With the advent of information technologies, legal frameworks and standards alone are not sufficient to preserve the privacy of data subjects. As a response, Privacy by Design (PbD) has emerged as a proactive approach for embedding privacy into the early stages of the design process. Challenges involved in engineering PbD include a lack of holistic methodologies that address the plurality and contextuality of privacy and support the translation of its principles into engineering activities. In this dissertation, we investigate various methods for engineering PbD that capture and address privacy issues in the early stages of the design process. We also investigate how to model the key aspects of abstract privacy principles stated in legal frameworks and standards to bridge the semantic gap between technical and normative concepts. This gives rise to the Abstract Personal Data Lifecycle (APDL) model, which serves as an abstract model for personal data lifecycles. We also define a UML profile for the APDL model to represent data-processing activities in a way that is amenable to risk analysis and compliance checking. In addition, we develop a privacy risk model that defines the main factors that have impacts on privacy risks along with their assessable attributes and conceptual relationships. Based on this, we develop analysis and assessment approaches that illustrate how combinations of these factors are analysed and used as inputs to assess the levels of risk. Furthermore, we characterise privacy protection as a quality attribute by means of a general quality attribute scenario to avoid non-operational or overlapping definitions. Based on this, we develop a tactical approach that identifies privacy architectural strategies as collections of tactics, which are described through design patterns, to support the adoption of Privacy-Enhancing Technologies (PETs), and to specify, implement and justify various levels of privacy protection. Together, these contributions give rise to a principled approach for engineering PbD that captures privacy concerns in a comprehensive manner; addresses these concerns at an architectural level; and reasons about the compliance of architectural choices with legal frameworks and standards. It is aided by techniques and tools, which provide procedures with a prescribed language and notation, to accomplish its activities.</p

A principled approach for engineering privacy by design

Privacy is a multi-faceted concept that has several aspects. It is subjective in nature, not least because it is influenced by a variety of factors, including societal demands, which evolve over time, and technological developments. With the advent of information technologies, legal frameworks and standards alone are not sufficient to preserve the privacy of data subjects. As a response, Privacy by Design (PbD) has emerged as a proactive approach for embedding privacy into the early stages of the design process. Challenges involved in engineering PbD include a lack of holistic methodologies that address the plurality and contextuality of privacy and support the translation of its principles into engineering activities. In this dissertation, we investigate various methods for engineering PbD that capture and address privacy issues in the early stages of the design process. We also investigate how to model the key aspects of abstract privacy principles stated in legal frameworks and standards to bridge the semantic gap between technical and normative concepts. This gives rise to the Abstract Personal Data Lifecycle (APDL) model, which serves as an abstract model for personal data lifecycles. We also define a UML profile for the APDL model to represent data-processing activities in a way that is amenable to risk analysis and compliance checking. In addition, we develop a privacy risk model that defines the main factors that have impacts on privacy risks along with their assessable attributes and conceptual relationships. Based on this, we develop analysis and assessment approaches that illustrate how combinations of these factors are analysed and used as inputs to assess the levels of risk. Furthermore, we characterise privacy protection as a quality attribute by means of a general quality attribute scenario to avoid non-operational or overlapping definitions. Based on this, we develop a tactical approach that identifies privacy architectural strategies as collections of tactics, which are described through design patterns, to support the adoption of Privacy-Enhancing Technologies (PETs), and to specify, implement and justify various levels of privacy protection. Together, these contributions give rise to a principled approach for engineering PbD that captures privacy concerns in a comprehensive manner; addresses these concerns at an architectural level; and reasons about the compliance of architectural choices with legal frameworks and standards. It is aided by techniques and tools, which provide procedures with a prescribed language and notation, to accomplish its activities.</p