Operational simulation and an economical modelling study on utilizing waste heat energy in a desalination plant and an absorption chiller

PhD ThesisIt is well established that a large proportion of the global emission of greenhouse gases are produced by electricity power stations and that a power plant typically emits about two thirds of its input energy as waste heat into the atmosphere. As such there is a lot of potential for additional applications that utilize this waste heat energy. Utilizing this waste heat energy in a desalination plant to produce low-cost potable water is the key to overcoming three problems at once, namely the water shortage in and and semi-arid areas, the continuing increase in oil prices by being more efficient and global warming. In all waste heat recovery or alternative energy systems based on natural phenomena (solar or wind) a major difficulty is decoupling supply from demand as thermal storage is neither efficient nor practical in many cases. A significant difficulty of gas turbine based power generation systems is the derating caused by high ambient temperatures; typically a 1% change in ambient temperature produces a similar reduction in efficiency. Therefore, by also utilizing this waste heat energy in an absorption chiller to pre-cool the gas turbine's compressor inlet-air, the effect of ambient temperature fluctuations on the gas turbine's performance would be eliminated. The combined cycle described in this study was designed in an attempt to address these issues. A gas turbine based combined heat and power plant was combined further with an absorption refrigeration unit and an MED desalination plant. The absorption unit stabilizes the operation of the gas turbine, reducing the sensitivity to changes in ambient temperature and the desalination plant acts as an energy utilization device that produces a usable product (40,000m3/day of potable water) that is easily stored and distributed as required. The simulation was performed using IPSEpro on the basis of real data obtained from an existing power plant and commercially available plants. The performance of the sub-plants was investigated using energy and exergy analyses, in design and off-design conditions using real weather data obtained from the Presidency of Meteorology and Environment in Saudi Arabia. Two different desalination technologies and two different coupling techniques were examined in four proposed plants. An optimal plant design was chosen from a comparison between all proposed plants' energy and exergy analysis results. The chosen plant was then optimized and simulated in design and off-design conditions. The initial results indicated that the simulated combined power plant's carbon footprint was reduced by 36.8% and its energy utilization factor was improved by 30.97%. This approach also stabilized the effect of ambient temperature fluctuations on the gas turbine's performance. After optimization, the carbon footprint was further reduced by 31.17% and the energy utilization factor was further improved by 6.11%. The energy destroyed through the exhaust stack was reduced by 78% and the proposed plant's overall exergetic efficiency was improved to 49.64%. Furthermore, the desalination plant's concentration factor was reduced by 0.45 and an additional product of a hot water stream at a temperature of 75°C was gained. An economic study was performed that indicated that the optimized plant is economically viable. As part of this analysis, a number of sensitivity studies defined the minimum selling prices of the plant's products and indicated the influence of fuel price, interest rates, capacity factors and project lifetime on the viability of the plant. The results also indicated that the proposed plant is a good investment, offering competitive energy and potable water prices, in regard to the location indicated by this study

Operational simulation and an economical modelling study on utilizing waste heat energy in a desalination plant and an absorption chiller

It is well established that a large proportion of the global emission of greenhouse gases are produced by electricity power stations and that a power plant typically emits about two thirds of its input energy as waste heat into the atmosphere. As such there is a lot of potential for additional applications that utilize this waste heat energy. Utilizing this waste heat energy in a desalination plant to produce low-cost potable water is the key to overcoming three problems at once, namely the water shortage in and and semi-arid areas, the continuing increase in oil prices by being more efficient and global warming. In all waste heat recovery or alternative energy systems based on natural phenomena (solar or wind) a major difficulty is decoupling supply from demand as thermal storage is neither efficient nor practical in many cases. A significant difficulty of gas turbine based power generation systems is the derating caused by high ambient temperatures; typically a 1% change in ambient temperature produces a similar reduction in efficiency. Therefore, by also utilizing this waste heat energy in an absorption chiller to pre-cool the gas turbine's compressor inlet-air, the effect of ambient temperature fluctuations on the gas turbine's performance would be eliminated. The combined cycle described in this study was designed in an attempt to address these issues. A gas turbine based combined heat and power plant was combined further with an absorption refrigeration unit and an MED desalination plant. The absorption unit stabilizes the operation of the gas turbine, reducing the sensitivity to changes in ambient temperature and the desalination plant acts as an energy utilization device that produces a usable product (40,000m3/day of potable water) that is easily stored and distributed as required. The simulation was performed using IPSEpro on the basis of real data obtained from an existing power plant and commercially available plants. The performance of the sub-plants was investigated using energy and exergy analyses, in design and off-design conditions using real weather data obtained from the Presidency of Meteorology and Environment in Saudi Arabia. Two different desalination technologies and two different coupling techniques were examined in four proposed plants. An optimal plant design was chosen from a comparison between all proposed plants' energy and exergy analysis results. The chosen plant was then optimized and simulated in design and off-design conditions. The initial results indicated that the simulated combined power plant's carbon footprint was reduced by 36.8% and its energy utilization factor was improved by 30.97%. This approach also stabilized the effect of ambient temperature fluctuations on the gas turbine's performance. After optimization, the carbon footprint was further reduced by 31.17% and the energy utilization factor was further improved by 6.11%. The energy destroyed through the exhaust stack was reduced by 78% and the proposed plant's overall exergetic efficiency was improved to 49.64%. Furthermore, the desalination plant's concentration factor was reduced by 0.45 and an additional product of a hot water stream at a temperature of 75°C was gained. An economic study was performed that indicated that the optimized plant is economically viable. As part of this analysis, a number of sensitivity studies defined the minimum selling prices of the plant's products and indicated the influence of fuel price, interest rates, capacity factors and project lifetime on the viability of the plant. The results also indicated that the proposed plant is a good investment, offering competitive energy and potable water prices, in regard to the location indicated by this study.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The Metaphorical Character in the Poetry of Abdullah Al-Bardouni: A Semiotic Study

تقف هذه الدراسة على مدونة الشاعر عبد الله البردوني الشعرية عبر زاوية محددة، تنظر إلى تجربته وواقعه الذي جسده في النص على أسس إنسانية يستمدها من استعارة الشاعر للشخصيات الإنسانية؛ والشاعر حين يقيم نصه على أسس إنسانية لا يختلقها من العدم، وإنما هو يستمدها من تجربته الإنسانية ومن واقعه بوصفه مصدرا يستدعي منه مادته الإنسانية والاستدعاء ليس غاية في ذاته، والشاعر حين يستدعي شخصية من التراث مثلا لا يستهدف مجرد الاستدعاء؛ فالاستدعاء هنا يكون بمثابة تغيير للسياق حيث ينقل الشاعر الشخصية من سياقها السابق لسياق جديد مستهدفا تخصيب دلالة جديدة تنضاف إلى الدلالة القائمة في السياق السابق.  الشخصيات المستعارة شخصيات جاهزة الوجود فالشاعر لم يبتكرها الشاعر من العدم، وإنما هي شخصيات حققت وجودها في الواقع واستقرت في الذهن الجمعي لذا فالشاعر ليس في حاجة  إلى تعريفها أو تقديم بطاقة تعريف بها إذ هو يستعيرها من منطقة الشهرة، وجاهزية الشخصية سلاح ذو حدين، فليست هي المجهولة التي يتشوق المتلقي لمعرفتها، وهو ما يحسب للمتلقي، وإنما هي المعروفة التي قد تجعل المتلقي يحجم عن معرفتها فاقدا التشوق لما يطرحه الشاعر لها من سمات فنية تجعلها في صورة قابلة للتشوق، أي إن الشاعر يقاوم  جاهزية الشخصية بتقديم جاهزية جديدة. ولكون الإنسان موضوعاً للخطاب الأدبي، وكونه منتجاً للخطاب بوظيفته الجمالية التي يؤديها وتوظيفها عبر آلية محددة تتقدم هذه الدراسة لتحقيق أهدافها في ثلاث خطوات أساسية: الكشف عن مفهوم الاستعارة وكيف تحققت لدى الشاعر. أنماط الشخصيات المستعارة، واختيار ثلاث شخصيات تبيانا لمساحة ظهورها. الوقوف على أربعة وظائف حققتها استعارة الشخصية: اللغوية، البلاغية، السردية، الدلالية.    This study deals with the poetic blog of the poet Abdullah Al Bardony from a certain perspective. It deals with his experience and the reality he embodied in the text based on human bases which the poet extracts from recalling previous human characters. Upon doing that, the poet does not create these human bases from the beginning but he extracts them from his human experience and from his reality which he considers a source from which he recalls his human material. Recalling that is not an end. The poet does not intend only such recall such as when he recalls a character from heritage. The recall here is a change of context where the poet removes the character from a context to another with the intention to target the enrichment of a new meaning to be added to the outstanding meaning in the previous context. Recalling previous characters is like borrowing characters that were ready in existence. The poet did not create them from nothing. They are characters that were realized in reality and felt by the minds of the people. The poet does not need to define such characters or to identify them to the society. He borrows these characters as they are famous everywhere. The preparation of characters is a double-edged weapon. They are not unknown so that recipients are eager to know them but they are already known so that recipients may be reluctant to know them as they are losing passion to what artistic features the poet may cover them with to make these characters appear appalling. In short, the poet resists the preparedness of characters with the presentation of a new preparedness. Since man is the main theme of the art work, and since man is producing the dialogue through its whole function that he may perform and employ through a certain mechanism, this study aims at achieving its objectives through three main steps: Defining the term of borrowing (recalling previous characters) and how did the poet realize it. Types of recalled (borrowed) characters and choosing three of them to identify the size of their presence. Identifying four functions realized by recalling (borrowing) characters: linguistic, rhetoric, narrative and semantic functions. &nbsp

Studies on Polybenzimidazole and Methanesulfonate Protic-Ionic-Liquids-Based Composite Polymer Electrolyte Membranes

Funding Information: This project was funded by the National Plan for Science, Technology and Innovation (MAARIFAH), King Abdulaziz City for Science and Technology, Kingdom of Saudi Arabia, Award Number (2-17-01-001-0042). Publisher Copyright: © 2023 by the authors.In the present work, different methanesulfonate-based protic ionic liquids (PILs) were synthesized and their structural characterization was performed using FTIR, 1H, and 13C NMR spectroscopy. Their thermal behavior and stability were studied using DSC and TGA, respectively, and EIS was used to study the ionic conductivity of these PILs. The PIL, which was diethanolammonium-methanesulfonate-based due to its compatibility with polybenzimidazole (PBI) to form composite membranes, was used to prepare proton-conducting polymer electrolyte membranes (PEMs) for prospective high-temperature fuel cell application. The prepared PEMs were further characterized using FTIR, DSC, TGA, SEM, and EIS. The FTIR results indicated good interaction among the PEM components and the DSC results suggested good miscibility and a plasticizing effect of the incorporated PIL in the PBI polymer matrix. All the PEMs showed good thermal stability and good proton conductivity for prospective high-temperature fuel cell application.publishersversionpublishe

Cervical cancer in Saudi Arabia: trends in survival by stage at diagnosis and geographic region

Background: Regional differences in cervical cancer survival have been reported in several countries. They may result from disparities in access to early diagnostic services, timely referral or appropriate treatment. Estimates of survival by stage at diagnosis could help to distinguish whether lower-than-expected survival is due to late-stage diagnosis or sub-optimal management, and to inform health-policy makers for resource allocation. In this retrospective cohort study, we aim to provide a detailed and up-to-date analysis of cervical cancer survival in Saudi Arabia by stage and region, and to explore whether any differences in survival between regions are due to differences in stage at diagnosis. Methods: Data on all women diagnosed with invasive cervical cancer during 2005–2016 were obtained from the Saudi Cancer Registry (SCR). Vital status and date of death if dead were ascertained by linking the registry records to vital registration data in the National Information Centre (NIC) of the Ministry of Interior. Women for whom no death record existed on the day of record linkage were considered to be alive. We estimated age-standardised five-year net survival using the Pohar-Perme estimator for women diagnosed during 2005–2010 and 2011–2016. Survival was also estimated by region and stage at diagnosis, and by region stratified by stage. Results: Age-standardised 5-year net survival did not change in Saudi Arabia between 2005–2010 [59.2%; 95% confidence interval (CI) 52.7–65.7%] and 2011–2016 (59.7%; 54.7–64.6%), or in any of the regions, except Makkah, where there was a 19% increase in survival for women diagnosed during 2011–2016 compared to 2005–2010. Survival for women diagnosed at a distant stage was substantially lower in the Eastern Region than in other regions. Conclusions: Cervical cancer survival has remained largely unchanged. Higher survival could be achieved by improving early diagnosis and access to high-quality treatment

Mechanical, thermal and morphological studies of microfibrillated jute/PLA biocomposites

In the present study, biocomposites based on microfibrillated jute (MFJ) fibre and polylactic acid (PLA) have been prepared by solvent-assisted compression moulding techniques. The MFJ is obtained by a sequence of alkali, chlorite and acid treatments of jute fibre. The biocomposites are fabricated by loading of 10, 20 and 30 wt% of MFJ fibre into the PLA matrix. The effect of MFJ fibre loading on the mechanical, thermal, and morphological properties of the composites is also studied. Among these composites, it is observed that 10 wt% fibre-filled biocomposite shows improved tensile strength andtensile modulus compared to virgin PLA film. Similarly, storage modulus and loss modulus are also found improved for the composites. These composites exhibit higher water absorption capacity and lower thermal stability than virgin PLA. The fibre-matrix adhesion is evaluated by scanning electron microscopy. The results are attributed to the improved interfacial adhesion between MFJ and PLA matrix for 10 wt% fibre-filled biocomposites

Characterization of Thermal, Ionic Conductivity and Electrochemical Properties of Some p-Tosylate Anions-Based Protic Ionic Compounds

Kingdom of Saudi Arabia, Award Number (2-17-01-001-0042In the present work, six protic ionic liquid (PIL) compounds based on p-toluene sulfonic acid [PTSA] anion along with different cations viz. tetraethylenepentammonium [TEPA], triethy-lammonium [TEA], pyridinium [Py], N-methylpiperidinium [Pip], 1-methylimidazolium [Im], and N-methylpyrrolidinium [Pyrr] were synthesized using the standard neutralization reaction method. The structural characterization of these compounds was achieved using FTIR,1H and13C NMR spectroscopies. Thermal behavior was studied using differential scanning calorimetry to determine the melting point (Tm) and crystallization (Tc ) temperatures. Thermogravimetric analysis was carried out to determine the thermal stability and degradation temperatures (Tdec) and to ascertain the hygroscopic or hydrophobic nature of the synthesized compounds. Structural effects on the outcome of various properties were witnessed and discussed in detail. Electrochemical impedance spectroscopy was utilized to study the electrical transport properties of the PILs at different temperatures. Cyclic voltammetry was performed to analyze the electrochemical stability of these PILs. Low values of activation energy indicating easy proton transportation along with good electrochemical stability make the PILs a potential candidate for use in the preparation of polymer electrolytes membranes for fuel cell applications.publishersversionpublishe

Literature review on the efficacy of near-infrared device in improving peripheral venous access time and number of attempts in pediatric patients

IntroductionThe process of peripheral venous access (PVA) in children can be challenging for the patient and the clinician, as failed attempts often exceed the recommended two insertions, which can be painful. To speed up the process and increase success, near-infrared device (NIR) device technology has been introduced. This literature review aimed to investigate and critically evaluate the impact of NIR devices on the number of attempts and the time of the catheterization procedure in pediatric patients from 2015 to 2022.MethodsAn electronic search was performed to identify studies in PubMed, Web of Science, Cochrane Library, and CINAHL Plus, from 2015 to 2022. After applying eligibility criteria, seven studies were considered for further review and evaluation.ResultsThe number of successful venipuncture attempts ranged from 1 to 2.41 in control groups and from 1 to 2 in NIR groups. The procedural time required for success ranged from 37.5 s to 252 s in the control group and from 28.47 s to 200 s in the NIR groups. The NIR assistive device could be successfully used in preterm infants and children with special health care needs.ConclusionsWhile more research is needed to examine the training and application of NIR in preterm infants, some studies have shown improvement in placement success. The number of attempts and time required for a successful PVA may depend on several alternative factors, including general health, age, ethnicity, and knowledge and skills of healthcare providers. Future studies are expected to investigate how the level of experience of a healthcare provider performing venipuncture influences the outcome. More research is needed to explore additional factors that predict the success rate

The Role of Family Physicians in Mental Health Care: Screening, Diagnosis, and Treatment Options

amily physicians play a pivotal role in the early detection, diagnosis, and management of mental health disorders within the community. This review article delves into the multifaceted responsibilities of family physicians in the realm of mental health care. Emphasizing the importance of primary care settings as the first point of contact for many patients, the article underscores the need for effective screening tools and methodologies tailored for these environments. The diagnostic precision of family physicians, often challenged by the broad spectrum of mental health symptoms, is explored alongside the potential implications of misdiagnoses. Furthermore, the article evaluates various treatment options, from pharmacological interventions to psychotherapy, and their applicability in primary care settings. The integration of technological advancements, such as electronic health records and telemedicine, is also discussed in the context of enhancing patient care. The review concludes by highlighting the importance of educating primary care physicians to not only pay close attention to the mental health of their patients, but also to be able to accurately screen and diagnose mental health issues using various diagnostic tools. Moreover, it is critical to develop more useful tools that can be used in the context of primary care settings

Neuroprotective effect of ranolazine improves behavioral discrepancies in a rat model of scopolamine-induced dementia

BackgroundRanolazine (Rn), an antianginal agent, acts in the central nervous system and has been used as a potential treatment agent for pain and epileptic disorders. Alzheimer’s disease (AD) is one of the most prevalent neurodegenerative diseases and the leading factor in dementia in the elderly.AimWe examined the impact of Rn on scopolamine (Sco)-induced dementia in rats.MethodsThirty-two albino male rats were divided into four groups: control, Rn, Sco, and Rn + Sco.ResultsA significant decrease in the escape latency in the Morris water maze test after pre-treatment with Rn explained better learning and memory in rats. Additionally, Rn significantly upregulated the activities of the antioxidant enzymes in the treated group compared to the Sco group but substantially reduced acetylcholinesterase activity levels in the hippocampus. Moreover, Rn dramatically reduced interleukin-1 β (IL-1β) and IL-6 and upregulated the gene expression of brain-derived neurotrophic factor (BDNF). Furthermore, in the Sco group, the hippocampal tissue’s immunohistochemical reaction of Tau and glial factor activating protein (GFAP) was significantly increased in addition to the upregulation of the Caspase-3 gene expression, which was markedly improved by pre-treatment with Rn. The majority of pyramidal neurons had large vesicular nuclei with prominent nucleoli and appeared to be more or less normal, reflecting the all-beneficial effects of Rn when the hippocampal tissue was examined under a microscope.ConclusionOur findings indicated that Rn, through its antioxidative, anti-inflammatory, and anti-apoptotic effects, as well as the control of the expression of GFAP, BDNF, and Tau proteins, has a novel neuroprotective impact against scopolamine-induced dementia in rats