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Preparation and Characterization of a Dye Sensitized Solar Cell used Liquid Electrolyte
(2022-06-06) Amal Musaad Ghannam Al-Mutairi; Fikria Zoghbi Jabli
Dye-Sensitized Solar Cell (DSSC) is a third-generation solar cell, consisting of a semiconductor electrode, a sensitizer, an electrolyte, and a counter electrode. This work aims to verify the use of various plant extracts as a natural dye inducer to improve the performance efficiency of DSSCs associated with the interaction between the dye and the TiO2 surface. Natural dyes have become more popular as an alternative to expensive and rare organic catalysts due to their low cost, non-toxicity, high performance, abundant supply of raw materials, various colours, and eco-friendly nature. In this work six natural dyes were used as photosensitizers for DSSCs which were extracted from raspberries, blackberries, spinach, red cabbage, blood orange, and beetroot. Subsequently, its optical properties were studied. During preparation of the cells, we used two types of titanium dioxide: the commercial TiO2 and laboratory–prepared meso-TiO2 as photoelectrode and the platinum as counter electrode. In this research, two different types of natural dye solar cells were adopted based on blackberry dye and another dye which is a mixture of natural dyes consisting of red cabbage + spinach + blackberry. Additionally, the photoelectrode was prepared by Electrophoretic Deposition (EPD) method that used to deposit the TiO2 layer on the FTO glass, and the counter electrode was prepared from Chloroplatinic Acid through thin layers of platinum which were deposited on the glass slides using the spin–coating method. Also, we studied the optical and structural properties of titanium dioxide powder. After several experiments, three cells were prepared (two with meso-TiO2 and one with Commercial TiO2). We collected the cells by using a liquid electrolyte, i.e., an iodine solution and tested them under illumination and in the dark then studied their electrical properties and obtained their characteristic curves. In the cell of meso- TiO2 with mix dye we got the highest value and curve of current density compared to the other cell, which is about 2.93 mA/cm2 with values of VOC = 0.76V (the open circuit voltage), FF = 62.98% (the fill factor) and the power conversion efficiency η = 1.4%. The other highest value of the power conversion efficiency was also in meso-TiO2 photoelectrode cell with blackberry dye; it equals η = 0.72 with values VOC = 0.64V, Jsc =2.29 mA/cm2, FF = 49.1%. It is hoped that this work will contribute to the exploitation of sunlight and the development of greener energy generation.
Students' Engagmentin Independent Learning and Personal Development: Issues, Attitudes and difficulties from the Female learners Experinces in the Context of Sauid Higher Education
(Saudi Digital Library, ) SAHAR MOHAMMED ALKHATHLAN; Dr. Judith Kleine-Staarm and Dr. Shirley Larkinan
Personal access to digital information affects all situations in life, from lifelong learning and careers to teaching and learning practices. Recently, there has been interest in individuals’ uses of social media, its association with personal and academic development, and its extensive use in both formal and informal educational contexts. In the Kingdom of Saudi Arabia (KSA), particular research attention has been given to females’ use of social media due to the significance of such easy access to their learning and development in the broader cultural context. However, little is known about the educational implications of such extended personal learning practices. For instance, the issues, attitudes and difficulties of students’ engagement, and the students’ changing needs and expectations under current social media influence, are still not fully understood. This research employs an Interpretive Phenomenological Analysis (IPA) to investigate the lived learning experiences of female university students, focusing on their personal use of social media to examine current issues in students’ experiences in Saudi higher education. A group of female undergraduate learners in a Saudi higher education context were selected to offer the learners’ voice and perspective on educational issues related to their own engagement. Students’ personal accounts and different stories of engagement in independent learning and personal development from their use of social media have been collected through two phases. In the first phase, 20 female students participated in in-depth individual interviews and reflective diary reports. In the second phase, 12 female students participated in two focus group discussions to elicit their attitudes and opinions. The (IPA) analysis of the data drawing from different educational theories in the literature was used to understand factors related to students’ engagement and non-engagement from their different attitudes and stories of success and failure when using social media independently. Themes that emerged as drivers and motivations leading to students’ engagement in learning and personal development included self-efficacy and reflection, personal values and beliefs, awareness of opportunity, challenges and transitions, social inclusion and empowerment with learning choice. Several themes were also revealed from the personal accounts as barriers and difficulties for students’ engagement, including personal negative attitudes and experiences, understanding of social media risk, information overload and distraction, organisational, pedagogical and curriculum barriers, lack of social inclusion, technical problems, and time and cost issues. The research concludes with several recommendations for improving all students’ engagement under the current themes of personal and self-directed lifelong learning with matching curriculum and pedagogies adopted in this context to meet current student learning needs.  
Understanding the Metabolic Regulation of the Transcription Factor c-Maf in Human CD4+ T Cells
(Saudi Digital Library, ) LAULWA NASSER MOHAMMAD ALSALLUM; Esperanza Perucha SpLab
c-Maf is a member of the Activator Protein-1 transcription factor superfamily and has been characterized as a master regulator of IL-10 expression in T cells. It plays key roles in the differentiation and function of various effector T cell lineages. In purified human CD4+ T cells, IL-10 has been proven to be metabolically regulated by cellular metabolism, as was c-Maf. Considering the above, we aimed to characterize the way in which c-Maf expression is regulated by the cholesterol biosynthesis pathway, particularly focusing on the stimulation signals that would upregulate the transcription factor and on the effects the perturbation of the cholesterol pathway would have on c-Maf. Through analyses by quantitative real-time PCR and flow cytometry, it was proven that stimulation via anti-CD3 and recombinant human interleukin-2 upregulated c-Maf expression. Inhibition of the cholesterol biosynthesis pathway with 25-hydroxycholesterol significantly decreased the levels of c-Maf, both at the protein and mRNA level and analysing the CD4+ T cells post inhibition via flow cytometry revealed decreased staining for phosphorylated STAT5. Introducing cholesterol to our cell cultures restored the pathway back to homeostasis and regained c-Maf expression, implying a link between sterol metabolism and the regulation of c-Maf. Our data also reveals IL-2 to be crucial in regulating c-Maf via its signalling through the IL-2 receptor and phosphorylated STAT5.
(Saudi Digital Library, ) FAHAD MUNAYZIL FAHAD ALANAZI; Mr. Mike Kelleher
Objective: To perform a systematic appraisal to compare the effectiveness of the use of endotracheal tube with continuous and intermittent suction drainage system on the rate of VAP, length of stay in ICU, and mortality rate. Methods: PubMed, CINAHL, MIDLINE, and Cochrane databases were used to find relevant articles. Peer-reviewed, full-text, and original article that were written in English-language and published between 2000 to May 2019 included in the study. The articles must be randomized control trial and used either continuous and/or intermittent suction drainage system as an intervention and ventilator-associated pneumonia rate, length of stay in intensive care unit, and/or mortality rate as an outcome. Data were analyzed using secondary analysis. Findings: 10 primary studies met the inclusion criteria of this study. These studies were summarized and criticized. Out of 10 studies, 7 studies supported that the two types of subglottic suction drainage can be used to reduce ventilator associated pneumonia. 7 studies from the 10 also examined the effect of intensive care unit length of stay and mortality rate and only 3 studies found reduction on the length of stay, whereas reduction on the mortality rate was found only on 2 studies. Conclusion: This systematic appraisal concluded that both intermittent and continuous subglottic suction drainage appears to be an effective intervention on reducing the rate of ventilator associated pneumonia, but not necessarily the length of stay in the intensive care unit and mortality rate.
Investigating Domestic Violence through Human Rights Lens in the Kingdom of Saudi Arabiar
(Saudi Digital Library, ) SALEH EWAIDH ALOSAIMI; Prof. Niaz Shah
Domestic violence can happen to anyone, but women and children in most cases of abuse are the victims. Despite considerable scholarship on domestic violence, Saudi Arabia remains an anomaly in terms of the Kingdom’s approach to domestic violence from both a social and legal perspective. In 2013 a new law was introduced in Saudi Arabia that outlawed all forms of domestic violence. Also, in 2000 the Kingdom ratified the Convention on the Elimination of All Forms of Discrimination (CEDAW) with a general reservation on the basis that precedence is given to Islamic law in the situation of conflict between CEDAW’s provisions and those of Islamic law. This research has taken the challenge of assessing the effectiveness of the 2013 Saudi domestic violence law; and investigates the compatibility of the new law with the rights mentioned in CEDAW and its complementary instruments. Through using a qualitative research approach based on textual legal analysis and conducting interviews with those involved in both the prevention and treatment of domestic violence, this thesis aims at offering an insight as to how the renaissance in outlawing domestic abuse works in practice. The thesis employs an interpretive approach aimed at understanding and reconciling Saudi domestic violence law and International Human Rights Law. The outcomes of the research reveal deficiencies in the legal text of the new Saudi Law; And highlight the performance of the Ministry of labour and Social Development . The thesis suggests that the differences between International Human Rights Law and Islamic law view with regard to combatting domestic violence are minimal, although there is some conceptual divergence regarding women’s rights. Finally, this thesis contends that there is an urgent need to reform the provisions of the Saudi domestic violence law; and a need to provide an additional legal framework that bridges the gender inequality gap and challenges gender discrimination in Saudi Arabia.