Optimization of an ultrasonic-assisted biodiesel production process from one genotype of rapeseed (TERI (OE) R-983) as a novel feedstock using response surface methodology
- Almasi, Sara, Ghobadian, Barat, Najafi, Gholam, Yusaf, Talal, Soufi, Masoud, Hoseini, Seyed
- Authors: Almasi, Sara , Ghobadian, Barat , Najafi, Gholam , Yusaf, Talal , Soufi, Masoud , Hoseini, Seyed
- Date: 2019
- Type: Text , Journal article
- Relation: Energies Vol. 12, no. 14 (2019), p. 1-14
- Full Text:
- Reviewed:
- Description: In recent years, due to the favorable climate conditions of Iran, the cultivation of rapeseed has increased significantly. The aim of this study was to investigate the possibility of biodiesel production from one genotype of rapeseed (TERI (OE) R-983). An ultrasonic approach was used in order to intensify the reaction. Response surface methodology (RSM) was applied to identify the optimum conditions of the process. The results of this research showed that the conversion of biodiesel was found to be 87.175% under the optimized conditions of a 4.63:1 molar ratio (methanol to oil), 56.50% amplitude, and 0.4 s pulses for a reaction time of 5.22 min. Increasing the operating conditions, such as the molar ratio from 4:1 to 5.5:1, amplitude from 50% to 72.5%, reaction time from 3 min to 7 min, and pulse from 0.4 s to 1 s, increased the FAME (fatty acid methyl esters) yield by approximately 4.5%, 2.3%, 1.2%, and 0.5%, respectively. The properties of the TERI (OE) R-983 methyl ester met the requirements of the biodiesel standard (ASTM D6751), indicating the potential of the produced biodiesel as an alternative fuel.
- Authors: Almasi, Sara , Ghobadian, Barat , Najafi, Gholam , Yusaf, Talal , Soufi, Masoud , Hoseini, Seyed
- Date: 2019
- Type: Text , Journal article
- Relation: Energies Vol. 12, no. 14 (2019), p. 1-14
- Full Text:
- Reviewed:
- Description: In recent years, due to the favorable climate conditions of Iran, the cultivation of rapeseed has increased significantly. The aim of this study was to investigate the possibility of biodiesel production from one genotype of rapeseed (TERI (OE) R-983). An ultrasonic approach was used in order to intensify the reaction. Response surface methodology (RSM) was applied to identify the optimum conditions of the process. The results of this research showed that the conversion of biodiesel was found to be 87.175% under the optimized conditions of a 4.63:1 molar ratio (methanol to oil), 56.50% amplitude, and 0.4 s pulses for a reaction time of 5.22 min. Increasing the operating conditions, such as the molar ratio from 4:1 to 5.5:1, amplitude from 50% to 72.5%, reaction time from 3 min to 7 min, and pulse from 0.4 s to 1 s, increased the FAME (fatty acid methyl esters) yield by approximately 4.5%, 2.3%, 1.2%, and 0.5%, respectively. The properties of the TERI (OE) R-983 methyl ester met the requirements of the biodiesel standard (ASTM D6751), indicating the potential of the produced biodiesel as an alternative fuel.
Decision making processes within educated intercultural marriages in Australia
- Authors: Alnaimi, Suleiman
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: In recent years, the world–wide phenomena of globalization and increasingly flexible social norms have contributed to an increase in intercultural relationships, particularly in multicultural societies. Intercultural relationships have a higher risk of failure and lower marital satisfaction than same-culture marriages. The negotiation of important family decisions are known to lead to marital conflict, however few studies have examined how successful, intercultural couples make important decisions and maintain marital satisfaction. Six intercultural couples who met the criteria were recruited and interviewed (ie.12 individuals).Couples were interviewed longitudinally on how they make important family decisions. The educational levels of participants ranged from college degree to PhD degree. The participants represented diverse cultural backgrounds. The various racial and/or ethnic identifications of the intercultural married couples in this study represented the diversity of the racial and/or ethnic mixes in intercultural marriages within the general population. Prior to completing the conjoint, face to face interviews, each couple completed the Schwartz Value Survey to elicit their individual values. Values are known to motivate and underpin decisions and vary from culture to culture. Interviews revealed that, although cultural differences were clearly evident, these differences did not prevent effective decision making amongst intercultural couples. Instead, couples were successfully turning cultural differences into minor issues or even opportunities. Couples often managed three cultures within the nuclear family as all couples had children being raised in Australia. Couples reported that keys to marital success included developing common values, working towards agreed goals and awareness of their spouse’s culture, support and open communication. Intercultural couples interviewed displayed positive attitudes of commitment to their marriage, each other and family. Couples focused on what was best for the family when making decisions. They held firm beliefs that they were not that different from their partner, despite cultural differences. Themes to emerge from qualitative analysis of the interviews as factors underpinning successful inter-cultural marriages across the participants include shared faith, similar values and the creation of a third culture within an emerging global culture. Cultural differences were not found to be a significant factor when major family decisions were made. This thesis is the first to examine decision making among successful intercultural couples. Qualitative study has investigated couple decision-making from the same cultural background. This current study generates new insights on intercultural couple’s decision making processes, and provides unique perspectives on how successful, well-adjusted and highly educated intercultural couples negotiate important family decisions. The findings of this study have the potential to add to the limited knowledge available on intercultural marriage and cross-cultural adjustment and has implications for counsellors and marriage / family therapists working with cross-cultural couples.
- Description: Doctor of Philosophy
- Authors: Alnaimi, Suleiman
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: In recent years, the world–wide phenomena of globalization and increasingly flexible social norms have contributed to an increase in intercultural relationships, particularly in multicultural societies. Intercultural relationships have a higher risk of failure and lower marital satisfaction than same-culture marriages. The negotiation of important family decisions are known to lead to marital conflict, however few studies have examined how successful, intercultural couples make important decisions and maintain marital satisfaction. Six intercultural couples who met the criteria were recruited and interviewed (ie.12 individuals).Couples were interviewed longitudinally on how they make important family decisions. The educational levels of participants ranged from college degree to PhD degree. The participants represented diverse cultural backgrounds. The various racial and/or ethnic identifications of the intercultural married couples in this study represented the diversity of the racial and/or ethnic mixes in intercultural marriages within the general population. Prior to completing the conjoint, face to face interviews, each couple completed the Schwartz Value Survey to elicit their individual values. Values are known to motivate and underpin decisions and vary from culture to culture. Interviews revealed that, although cultural differences were clearly evident, these differences did not prevent effective decision making amongst intercultural couples. Instead, couples were successfully turning cultural differences into minor issues or even opportunities. Couples often managed three cultures within the nuclear family as all couples had children being raised in Australia. Couples reported that keys to marital success included developing common values, working towards agreed goals and awareness of their spouse’s culture, support and open communication. Intercultural couples interviewed displayed positive attitudes of commitment to their marriage, each other and family. Couples focused on what was best for the family when making decisions. They held firm beliefs that they were not that different from their partner, despite cultural differences. Themes to emerge from qualitative analysis of the interviews as factors underpinning successful inter-cultural marriages across the participants include shared faith, similar values and the creation of a third culture within an emerging global culture. Cultural differences were not found to be a significant factor when major family decisions were made. This thesis is the first to examine decision making among successful intercultural couples. Qualitative study has investigated couple decision-making from the same cultural background. This current study generates new insights on intercultural couple’s decision making processes, and provides unique perspectives on how successful, well-adjusted and highly educated intercultural couples negotiate important family decisions. The findings of this study have the potential to add to the limited knowledge available on intercultural marriage and cross-cultural adjustment and has implications for counsellors and marriage / family therapists working with cross-cultural couples.
- Description: Doctor of Philosophy
Association between nocturnal activity of the sympathetic nervous system and cognitive dysfunction in obstructive sleep apnoea
- Alomri, Ridwan, Kennedy, Gerard, Wali, Siraj, Alhejaili, Faris, Robinson, Stephen
- Authors: Alomri, Ridwan , Kennedy, Gerard , Wali, Siraj , Alhejaili, Faris , Robinson, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 11, no. 1 (2021), p. 11990-11990.
- Full Text:
- Reviewed:
- Description: Obstructive sleep apnoea (OSA) is associated with repetitive breathing obstructions during sleep. These episodes of hypoxia and associated arousals from sleep induce physiological stress and nocturnal over-activation of the sympathetic nervous system (SNS). One consequence of OSA is impairment in a range of cognitive domains. Previous research into cognitive impairment in OSA have focussed on intermittent hypoxia and disrupted sleep, but not nocturnal over-activation of the SNS. Therefore, we investigated whether nocturnal over-activity of the SNS was associated with cognitive impairments in OSA. The extent of nocturnal SNS activation was estimated from heart rate variability (HRV), pulse wave amplitude (PWA) and stress response biomarkers (cortisol and glucose levels). OSA severity was significantly associated with PWA indices and the HRV low frequency/ high frequency ratio (p < 0.05). Morning blood glucose levels were significantly associated with the duration of a blood oxygen saturation (SaO2) < 90% (p < 0.01). PWA and HRV were significantly associated with the time taken to perform a task involving visuospatial functioning (p < 0.05), but not with impairments in sustained attention, reaction time or autobiographical memory. These results suggest that the visuospatial dysfunction observed in people with OSA is associated with increased nocturnal activity of the SNS. © 2021, The Author(s).
- Authors: Alomri, Ridwan , Kennedy, Gerard , Wali, Siraj , Alhejaili, Faris , Robinson, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 11, no. 1 (2021), p. 11990-11990.
- Full Text:
- Reviewed:
- Description: Obstructive sleep apnoea (OSA) is associated with repetitive breathing obstructions during sleep. These episodes of hypoxia and associated arousals from sleep induce physiological stress and nocturnal over-activation of the sympathetic nervous system (SNS). One consequence of OSA is impairment in a range of cognitive domains. Previous research into cognitive impairment in OSA have focussed on intermittent hypoxia and disrupted sleep, but not nocturnal over-activation of the SNS. Therefore, we investigated whether nocturnal over-activity of the SNS was associated with cognitive impairments in OSA. The extent of nocturnal SNS activation was estimated from heart rate variability (HRV), pulse wave amplitude (PWA) and stress response biomarkers (cortisol and glucose levels). OSA severity was significantly associated with PWA indices and the HRV low frequency/ high frequency ratio (p < 0.05). Morning blood glucose levels were significantly associated with the duration of a blood oxygen saturation (SaO2) < 90% (p < 0.01). PWA and HRV were significantly associated with the time taken to perform a task involving visuospatial functioning (p < 0.05), but not with impairments in sustained attention, reaction time or autobiographical memory. These results suggest that the visuospatial dysfunction observed in people with OSA is associated with increased nocturnal activity of the SNS. © 2021, The Author(s).
Differential associations of hypoxia, sleep fragmentation, and depressive symptoms with cognitive dysfunction in obstructive sleep apnea
- Alomri, Ridwan, Kennedy, Gerard, Wali, Siraj, Ahejaili, Faris, Robinson, Stephen
- Authors: Alomri, Ridwan , Kennedy, Gerard , Wali, Siraj , Ahejaili, Faris , Robinson, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Sleep Vol. 44, no. 4 (2021), p.
- Full Text:
- Reviewed:
- Description: Obstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete cessation of breathing during sleep and increased effort to breathe. This study examined patients who underwent overnight polysomnographic studies in a major sleep laboratory in Saudi Arabia. The study aimed to determine the extent to which intermittent hypoxia, sleep disruption, and depressive symptoms are independently associated with cognitive impairments in OSA. In the sample of 90 participants, 14 had no OSA, 30 mild OSA, 23 moderate OSA, and 23 severe OSA. The findings revealed that hypoxia and sleep fragmentation are independently associated with impairments of sustained attention and reaction time (RT). Sleep fragmentation, but not hypoxia, was independently associated with impairments in visuospatial deficits. Depressive symptoms were independently associated with impairments in the domains of sustained attention, RT, visuospatial ability, and semantic and episodic autobiographical memories. Since the depressive symptoms are independent of hypoxia and sleep fragmentation, effective reversal of cognitive impairment in OSA may require treatment interventions that target each of these factors. © Sleep Research Society 2020. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.
- Authors: Alomri, Ridwan , Kennedy, Gerard , Wali, Siraj , Ahejaili, Faris , Robinson, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Sleep Vol. 44, no. 4 (2021), p.
- Full Text:
- Reviewed:
- Description: Obstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete cessation of breathing during sleep and increased effort to breathe. This study examined patients who underwent overnight polysomnographic studies in a major sleep laboratory in Saudi Arabia. The study aimed to determine the extent to which intermittent hypoxia, sleep disruption, and depressive symptoms are independently associated with cognitive impairments in OSA. In the sample of 90 participants, 14 had no OSA, 30 mild OSA, 23 moderate OSA, and 23 severe OSA. The findings revealed that hypoxia and sleep fragmentation are independently associated with impairments of sustained attention and reaction time (RT). Sleep fragmentation, but not hypoxia, was independently associated with impairments in visuospatial deficits. Depressive symptoms were independently associated with impairments in the domains of sustained attention, RT, visuospatial ability, and semantic and episodic autobiographical memories. Since the depressive symptoms are independent of hypoxia and sleep fragmentation, effective reversal of cognitive impairment in OSA may require treatment interventions that target each of these factors. © Sleep Research Society 2020. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.
Triple Ps and Cs to solve the trouble of transition : A new theoretical model
- Alonaizi, Nafi, Paliadelis, Penny
- Authors: Alonaizi, Nafi , Paliadelis, Penny
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Health Specialties Vol. 3, no. 4 (2015), p. 216-223
- Full Text:
- Reviewed:
- Description: Aims: Aim of the study was to explore the experiences of interns and preceptors to develop a rich conceptual understanding of their experiences during the internship. Settings and Design: Purposeful sampling was used to recruit 22 interns and 11 preceptors during an internship program at a tertiary public hospital in Riyadh. Methods: We used qualitative research based on a phenomenological approach. The data was collected through semistructured interviews. Data Analysis: Interviews were transcribed verbatim and analysed concurrently using thematic analysis. Results: The internship program had a positive impact on interns and their preceptors. However, both groups reported negative issues related to their preparations (training) and emphasised the need for better cooperation between education and practical healthcare services. Conclusions: The findings lead the researchers to develop a new model for clinical education, future healthcare professionals and those who assist them during the internship, “The Triple Ps and Cs to solve the trouble of transition”.
- Authors: Alonaizi, Nafi , Paliadelis, Penny
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Health Specialties Vol. 3, no. 4 (2015), p. 216-223
- Full Text:
- Reviewed:
- Description: Aims: Aim of the study was to explore the experiences of interns and preceptors to develop a rich conceptual understanding of their experiences during the internship. Settings and Design: Purposeful sampling was used to recruit 22 interns and 11 preceptors during an internship program at a tertiary public hospital in Riyadh. Methods: We used qualitative research based on a phenomenological approach. The data was collected through semistructured interviews. Data Analysis: Interviews were transcribed verbatim and analysed concurrently using thematic analysis. Results: The internship program had a positive impact on interns and their preceptors. However, both groups reported negative issues related to their preparations (training) and emphasised the need for better cooperation between education and practical healthcare services. Conclusions: The findings lead the researchers to develop a new model for clinical education, future healthcare professionals and those who assist them during the internship, “The Triple Ps and Cs to solve the trouble of transition”.
Fitting Voronoi diagrams to planar tesselations
- Aloupis, Greg, Pérez-Rosés, Hebert, Pineda-Villavicencio, Guillermo, Taslakian, Perouz, Trinchet-Almaguer, Dannier
- Authors: Aloupis, Greg , Pérez-Rosés, Hebert , Pineda-Villavicencio, Guillermo , Taslakian, Perouz , Trinchet-Almaguer, Dannier
- Date: 2013
- Type: Text , Conference paper
- Relation: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) Vol. 8288 LNCS, p. 349-361
- Full Text:
- Reviewed:
- Description: Given a tesselation of the plane, defined by a planar straight-line graph G, we want to find a minimal set S of points in the plane, such that the Voronoi diagram associated with S 'fits' G. This is the Generalized Inverse Voronoi Problem (GIVP), defined in [12] and rediscovered recently in [3]. Here we give an algorithm that solves this problem with a number of points that is linear in the size of G, assuming that the smallest angle in G is constant. © 2013 Springer-Verlag.
- Authors: Aloupis, Greg , Pérez-Rosés, Hebert , Pineda-Villavicencio, Guillermo , Taslakian, Perouz , Trinchet-Almaguer, Dannier
- Date: 2013
- Type: Text , Conference paper
- Relation: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) Vol. 8288 LNCS, p. 349-361
- Full Text:
- Reviewed:
- Description: Given a tesselation of the plane, defined by a planar straight-line graph G, we want to find a minimal set S of points in the plane, such that the Voronoi diagram associated with S 'fits' G. This is the Generalized Inverse Voronoi Problem (GIVP), defined in [12] and rediscovered recently in [3]. Here we give an algorithm that solves this problem with a number of points that is linear in the size of G, assuming that the smallest angle in G is constant. © 2013 Springer-Verlag.
Evidence of subdivisions on evolutionary timescales in a large, declining marsupial distributed across a phylogeographic barrier
- Alpers, Deryn, Walker, Faith, Taylor, Andrea, Sunnucks, Paul, Bellman, Steven, Hansen, Birgita, Sherwin, William
- Authors: Alpers, Deryn , Walker, Faith , Taylor, Andrea , Sunnucks, Paul , Bellman, Steven , Hansen, Birgita , Sherwin, William
- Date: 2016
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 11, no. 10 (2016), p. 1-22
- Full Text:
- Reviewed:
- Description: Major prehistoric forces, such as the climatic shifts of the Pleistocene, can remain visible in a species' population genetics. Inference of refuges via genetic tools is useful for conservation management as it can identify populations whose preservation may help retain a species' adaptive potential. Such investigation is needed for Australia's southern hairy-nosed wombat (Lasiorhinus latifrons), whose conservation status has recently deteriorated, and whose phylogeographic history during the Pleistocene may be atypical compared to other species. Its contemporary range spans approximately 2000 km of diverse habitat on either side of the Spencer Gulf, which was a land bridge during periods of Pleistocene aridity that may have allowed for migration circumventing the arid Eyrean barrier. We sampled from animals in nearly all known sites within the species' current distribution, mainly using non-invasive methods, and employed nuclear and mitochondrial DNA analyses to assess alternative scenarios for Pleistocene impacts on population structure. We found evidence for mildly differentiated populations at the range extremes on either side of Spencer Gulf, with secondary contact between locations neighbouring each side of the barrier. These extreme western and eastern regions, and four other regions in between, were genetically distinct in genotypic clustering analyses. Estimates indicate modest, but complex gene flow patterns among some of these regions, in some cases possibly restricted for several thousand years. Prior to this study there was little information to aid risk assessment and prioritization of conservation interventions facilitating gene flow among populations of this species. The contributions of this study to that issue are outlined. © 2016 Alpers et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
- Authors: Alpers, Deryn , Walker, Faith , Taylor, Andrea , Sunnucks, Paul , Bellman, Steven , Hansen, Birgita , Sherwin, William
- Date: 2016
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 11, no. 10 (2016), p. 1-22
- Full Text:
- Reviewed:
- Description: Major prehistoric forces, such as the climatic shifts of the Pleistocene, can remain visible in a species' population genetics. Inference of refuges via genetic tools is useful for conservation management as it can identify populations whose preservation may help retain a species' adaptive potential. Such investigation is needed for Australia's southern hairy-nosed wombat (Lasiorhinus latifrons), whose conservation status has recently deteriorated, and whose phylogeographic history during the Pleistocene may be atypical compared to other species. Its contemporary range spans approximately 2000 km of diverse habitat on either side of the Spencer Gulf, which was a land bridge during periods of Pleistocene aridity that may have allowed for migration circumventing the arid Eyrean barrier. We sampled from animals in nearly all known sites within the species' current distribution, mainly using non-invasive methods, and employed nuclear and mitochondrial DNA analyses to assess alternative scenarios for Pleistocene impacts on population structure. We found evidence for mildly differentiated populations at the range extremes on either side of Spencer Gulf, with secondary contact between locations neighbouring each side of the barrier. These extreme western and eastern regions, and four other regions in between, were genetically distinct in genotypic clustering analyses. Estimates indicate modest, but complex gene flow patterns among some of these regions, in some cases possibly restricted for several thousand years. Prior to this study there was little information to aid risk assessment and prioritization of conservation interventions facilitating gene flow among populations of this species. The contributions of this study to that issue are outlined. © 2016 Alpers et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Organisational barriers to effective pain management amongst oncology nurses in Saudi Arabia
- Alqahtani, Mohammed, Jones, Linda, Holroyd, Eleanor
- Authors: Alqahtani, Mohammed , Jones, Linda , Holroyd, Eleanor
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Hospital Administration Vol. 5, no. 1 (2015), p. 81-89
- Full Text:
- Reviewed:
- Description: Cancer pain is a multi-dimensional syndrome with a combination of acute and chronic pain that causes physical, psycho-social, behavioural, emotional and spiritual problems resulting in adverse effects on patients’ quality of life. Nurses need to be well prepared with knowledge on pain assessment and management techniques in oncology units, due to their vital role in the decision-making process regarding pain management. However, limited research has been conducted regarding nurses’ barriers regarding pain management in oncology units, especially in Saudi Arabia. The overall aim of this study was to explore the nurses’ perceived barriers that hinder the delivery of effective pain management to cancer patients. Five focus group discussions were conducted using a purposive sampling of six to eight nurses in each group, with a total of 35 oncology nurses. The results of focus group analysis revealed two main thematic categories with associated sub themes, being nurses’ workloads, and the absence of health team collaboration. This study provides an increased awareness of the barriers that may hinder the efficacy of pain management provided to cancer patients in Saudi Arabia context. Significant implications will benefit nursing practice, administration and education, in addition to identifying potential future research.
- Authors: Alqahtani, Mohammed , Jones, Linda , Holroyd, Eleanor
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Hospital Administration Vol. 5, no. 1 (2015), p. 81-89
- Full Text:
- Reviewed:
- Description: Cancer pain is a multi-dimensional syndrome with a combination of acute and chronic pain that causes physical, psycho-social, behavioural, emotional and spiritual problems resulting in adverse effects on patients’ quality of life. Nurses need to be well prepared with knowledge on pain assessment and management techniques in oncology units, due to their vital role in the decision-making process regarding pain management. However, limited research has been conducted regarding nurses’ barriers regarding pain management in oncology units, especially in Saudi Arabia. The overall aim of this study was to explore the nurses’ perceived barriers that hinder the delivery of effective pain management to cancer patients. Five focus group discussions were conducted using a purposive sampling of six to eight nurses in each group, with a total of 35 oncology nurses. The results of focus group analysis revealed two main thematic categories with associated sub themes, being nurses’ workloads, and the absence of health team collaboration. This study provides an increased awareness of the barriers that may hinder the efficacy of pain management provided to cancer patients in Saudi Arabia context. Significant implications will benefit nursing practice, administration and education, in addition to identifying potential future research.
A robust consistency model of crowd workers in text labeling tasks
- Alqershi, Fattoh, Al-Qurishi, Muhammad, Aksoy, Mehmet, Alrubaian, Majed, Imran, Muhammad
- Authors: Alqershi, Fattoh , Al-Qurishi, Muhammad , Aksoy, Mehmet , Alrubaian, Majed , Imran, Muhammad
- Date: 2020
- Type: Text , Journal article
- Relation: IEEE Access Vol. 8, no. (2020), p. 168381-168393
- Full Text:
- Reviewed:
- Description: Crowdsourcing is a popular human-based model to acquire labeled data. Despite its ability to generate huge amounts of labelled data at moderate costs, it is susceptible to low quality labels. This can happen through unintentional or intentional errors by the crowd workers. Consistency is an important attribute of reliability. It is a practical metric that evaluates a crowd workers' reliability based on their ability to conform to themselves by yielding the same output when repeatedly given a particular input. Consistency has not yet been sufficiently explored in the literature. In this work, we propose a novel consistency model based on the pairwise comparisons method. We apply this model on unpaid workers. We measure the workers' consistency on tasks of labeling political text-based claims and study the effects of different duplicate task characteristics on their consistency. Our results show that the proposed model outperforms the current state-of-the-art models in terms of accuracy. This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/
- Authors: Alqershi, Fattoh , Al-Qurishi, Muhammad , Aksoy, Mehmet , Alrubaian, Majed , Imran, Muhammad
- Date: 2020
- Type: Text , Journal article
- Relation: IEEE Access Vol. 8, no. (2020), p. 168381-168393
- Full Text:
- Reviewed:
- Description: Crowdsourcing is a popular human-based model to acquire labeled data. Despite its ability to generate huge amounts of labelled data at moderate costs, it is susceptible to low quality labels. This can happen through unintentional or intentional errors by the crowd workers. Consistency is an important attribute of reliability. It is a practical metric that evaluates a crowd workers' reliability based on their ability to conform to themselves by yielding the same output when repeatedly given a particular input. Consistency has not yet been sufficiently explored in the literature. In this work, we propose a novel consistency model based on the pairwise comparisons method. We apply this model on unpaid workers. We measure the workers' consistency on tasks of labeling political text-based claims and study the effects of different duplicate task characteristics on their consistency. Our results show that the proposed model outperforms the current state-of-the-art models in terms of accuracy. This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/
Children and their parent's perceptions of overweight and obesity in Kuwait children
- Alrashidi, Mohammed, Shahwan-Akl, Lina, Jones, Linda, Jones, Katherine, James, Jennifer
- Authors: Alrashidi, Mohammed , Shahwan-Akl, Lina , Jones, Linda , Jones, Katherine , James, Jennifer
- Date: 2015
- Type: Text , Journal article
- Relation: International Journal of Current Research Vol. 7, no. 8 (2015), p. 19661-19666
- Full Text:
- Reviewed:
- Description: Background: The prevalence of overweight and obesity among children are a major public health concern internationally. Recognition of overweight and obesity status is an important step to prevent unhealthy weight. This study was designed to assess the prevalence and to explore the perceptions of children and their parents towards overweight and obesity in children. Methods: A cross-sectional study approach was utilized surveying 635 children aged 11 to 14 years (males and females) in 12 randomly selected public schools in Kuwait. Trained nurses performed measurements of children’s height and weight to determine their Body Mass Index.Valid questionnaire were used to assess children and their parent perception of child’s weight. Results: One quarter of the surveyed children 25.5% (N = 162) were overweight. Over one third of the participants 36.5% (N = 232) were classified as obese. The nurses’ measurements did not coincide with the children’s perceptions but were better aligned with parents’ perceptions of overweight and obesity. Conclusion: The results indicated that there is high prevalence of overweight and obesity among Kuwaiti children. Furthermore, both the children and their parents underestimate the child weight status. Health education programs are highly recommended.
- Authors: Alrashidi, Mohammed , Shahwan-Akl, Lina , Jones, Linda , Jones, Katherine , James, Jennifer
- Date: 2015
- Type: Text , Journal article
- Relation: International Journal of Current Research Vol. 7, no. 8 (2015), p. 19661-19666
- Full Text:
- Reviewed:
- Description: Background: The prevalence of overweight and obesity among children are a major public health concern internationally. Recognition of overweight and obesity status is an important step to prevent unhealthy weight. This study was designed to assess the prevalence and to explore the perceptions of children and their parents towards overweight and obesity in children. Methods: A cross-sectional study approach was utilized surveying 635 children aged 11 to 14 years (males and females) in 12 randomly selected public schools in Kuwait. Trained nurses performed measurements of children’s height and weight to determine their Body Mass Index.Valid questionnaire were used to assess children and their parent perception of child’s weight. Results: One quarter of the surveyed children 25.5% (N = 162) were overweight. Over one third of the participants 36.5% (N = 232) were classified as obese. The nurses’ measurements did not coincide with the children’s perceptions but were better aligned with parents’ perceptions of overweight and obesity. Conclusion: The results indicated that there is high prevalence of overweight and obesity among Kuwaiti children. Furthermore, both the children and their parents underestimate the child weight status. Health education programs are highly recommended.
Contributing factors to childhood overweight and obesity in Kuwait
- Alrashidi, Mohammed, Shahwan-Akl, Lina, James, Jennifer, Jones, Linda
- Authors: Alrashidi, Mohammed , Shahwan-Akl, Lina , James, Jennifer , Jones, Linda
- Date: 2015
- Type: Text , Journal article
- Relation: International Journal of Health Sciences (IJHS) Vol. 3, no. 1 (2015), p. 133-155
- Full Text:
- Reviewed:
- Description: The increasing prevalence of overweight and obesity in children is a major public health concern in Kuwait. Understanding the contributing factors is key to the development of an effective intervention strategy. This study was designed to identify what factors contribute to overweight and obesity in school-aged children. Method: A cross-sectional study, using questionnaires, was conducted with public intermediate school children (girls and boys) and their parents to elicit information related to the children’s daily lifestyle. A total of 635 children aged 11-14 years and their parents (N=635) were surveyed and children’s height and weight were measured by school nurses to identify their Body Mass Index. Results: When classified by BMI, about one quarter of the children (25.5%) were overweight and over one third (36.5%) were classified as obese. Multiple regression model found that the BMI of the male children increased significantly with respect to age if they had overweight siblings, spent time on sedentary activities, and regularly ate food from fast food restaurants. The BMI of the female children also increased significantly with respect to age, having overweight siblings, eating at fast food restaurants and for every time not actively travelling to school. Conclusion: The rate of childhood overweight and obesity in Kuwait is currently still high, and Kuwaiti children have been found to be leading unhealthy lifestyles. Involving parents as a part of the solution is an important step in promoting a healthy lifestyle.
- Authors: Alrashidi, Mohammed , Shahwan-Akl, Lina , James, Jennifer , Jones, Linda
- Date: 2015
- Type: Text , Journal article
- Relation: International Journal of Health Sciences (IJHS) Vol. 3, no. 1 (2015), p. 133-155
- Full Text:
- Reviewed:
- Description: The increasing prevalence of overweight and obesity in children is a major public health concern in Kuwait. Understanding the contributing factors is key to the development of an effective intervention strategy. This study was designed to identify what factors contribute to overweight and obesity in school-aged children. Method: A cross-sectional study, using questionnaires, was conducted with public intermediate school children (girls and boys) and their parents to elicit information related to the children’s daily lifestyle. A total of 635 children aged 11-14 years and their parents (N=635) were surveyed and children’s height and weight were measured by school nurses to identify their Body Mass Index. Results: When classified by BMI, about one quarter of the children (25.5%) were overweight and over one third (36.5%) were classified as obese. Multiple regression model found that the BMI of the male children increased significantly with respect to age if they had overweight siblings, spent time on sedentary activities, and regularly ate food from fast food restaurants. The BMI of the female children also increased significantly with respect to age, having overweight siblings, eating at fast food restaurants and for every time not actively travelling to school. Conclusion: The rate of childhood overweight and obesity in Kuwait is currently still high, and Kuwaiti children have been found to be leading unhealthy lifestyles. Involving parents as a part of the solution is an important step in promoting a healthy lifestyle.
Modeling cyclic crack propagation in concrete using the scaled boundary finite element method coupled with the cumulative damage-plasticity constitutive law
- Alrayes, Omar, Könke, Carsten, Ooi, Ean Tat, Hamdia, Khader
- Authors: Alrayes, Omar , Könke, Carsten , Ooi, Ean Tat , Hamdia, Khader
- Date: 2023
- Type: Text , Journal article
- Relation: Materials Vol. 16, no. 2 (2023), p.
- Full Text:
- Reviewed:
- Description: Many concrete structures, such as bridges and wind turbine towers, fail mostly due to the fatigue rapture and bending, where the cracks are initiated and propagate under cyclic loading. Modeling the fracture process zone (FPZ) is essential to understanding the cracking behavior of heterogeneous, quasi-brittle materials such as concrete under monotonic and cyclic actions. The paper aims to present a numerical modeling approach for simulating crack growth using a scaled boundary finite element model (SBFEM). The cohesive traction law is explored to model the stress field under monotonic and cyclic loading conditions. In doing so, a new constitutive law is applied within the cohesive response. The cyclic damage accumulation during loading and unloading is formulated within the thermodynamic framework of the constitutive concrete model. We consider two common problems of three-point bending of a single-edge-notched concrete beam subjected to different loading conditions to validate the developed method. The simulation results show good agreement with experimental test measurements from the literature. The presented analysis can provide a further understanding of crack growth and damage accumulation within the cohesive response, and the SBFEM makes it possible to identify the fracture behavior of cyclic crack propagation in concrete members. © 2023 by the authors.
- Authors: Alrayes, Omar , Könke, Carsten , Ooi, Ean Tat , Hamdia, Khader
- Date: 2023
- Type: Text , Journal article
- Relation: Materials Vol. 16, no. 2 (2023), p.
- Full Text:
- Reviewed:
- Description: Many concrete structures, such as bridges and wind turbine towers, fail mostly due to the fatigue rapture and bending, where the cracks are initiated and propagate under cyclic loading. Modeling the fracture process zone (FPZ) is essential to understanding the cracking behavior of heterogeneous, quasi-brittle materials such as concrete under monotonic and cyclic actions. The paper aims to present a numerical modeling approach for simulating crack growth using a scaled boundary finite element model (SBFEM). The cohesive traction law is explored to model the stress field under monotonic and cyclic loading conditions. In doing so, a new constitutive law is applied within the cohesive response. The cyclic damage accumulation during loading and unloading is formulated within the thermodynamic framework of the constitutive concrete model. We consider two common problems of three-point bending of a single-edge-notched concrete beam subjected to different loading conditions to validate the developed method. The simulation results show good agreement with experimental test measurements from the literature. The presented analysis can provide a further understanding of crack growth and damage accumulation within the cohesive response, and the SBFEM makes it possible to identify the fracture behavior of cyclic crack propagation in concrete members. © 2023 by the authors.
A new global index for short term voltage stability assessment
- Alshareef, Abdulrhman, Shah, Rakibuzzaman, Mithulananthan, Nadarajah, Alzahrani, Saeed
- Authors: Alshareef, Abdulrhman , Shah, Rakibuzzaman , Mithulananthan, Nadarajah , Alzahrani, Saeed
- Date: 2021
- Type: Text , Journal article
- Relation: IEEE Access Vol. 9, no. (2021), p. 36114-36124
- Full Text:
- Reviewed:
- Description: The utility scale of non-conventional generators (NCGs), such as wind and photovoltaic (PV) plants, are competitive alternatives to synchronous machines (SMs) for power generation. Higher penetration of NCGs has been respondent of causing several recent incidents leading up to voltage collapse in power systems due to the distinct characteristics of NCGs under different operating conditions. Consequently, the so-called system strength has been reduced with higher NCGs penetration. A number of indices have been developed to quantify system strength from the short-term voltage stability (STVS) perspective. None of the indices capture the overall performances of power systems on dynamic voltage recovery. In this paper, an improvement in one of the STVS indices namely, the Voltage Recovery Index (VRI), is proposed to overcome shortcomings in the original index. Moreover, the improved index is globalized to establish a new index defined as system voltage recovery index (VRIsys) to quantify STVS at the system level. The amended VRI and developed VRIsys are used in systematic simulations to quantify the impact and interaction of various factors that could affect system strength. The assessment was conducted using time-domain simulation with direct connected induction motors (DCIMs) and a proliferation of converter-based technologies on both the generation and load sides, namely, NCGs and Variable Speed Drives (VSDs), respectively. © 2013 IEEE.
- Authors: Alshareef, Abdulrhman , Shah, Rakibuzzaman , Mithulananthan, Nadarajah , Alzahrani, Saeed
- Date: 2021
- Type: Text , Journal article
- Relation: IEEE Access Vol. 9, no. (2021), p. 36114-36124
- Full Text:
- Reviewed:
- Description: The utility scale of non-conventional generators (NCGs), such as wind and photovoltaic (PV) plants, are competitive alternatives to synchronous machines (SMs) for power generation. Higher penetration of NCGs has been respondent of causing several recent incidents leading up to voltage collapse in power systems due to the distinct characteristics of NCGs under different operating conditions. Consequently, the so-called system strength has been reduced with higher NCGs penetration. A number of indices have been developed to quantify system strength from the short-term voltage stability (STVS) perspective. None of the indices capture the overall performances of power systems on dynamic voltage recovery. In this paper, an improvement in one of the STVS indices namely, the Voltage Recovery Index (VRI), is proposed to overcome shortcomings in the original index. Moreover, the improved index is globalized to establish a new index defined as system voltage recovery index (VRIsys) to quantify STVS at the system level. The amended VRI and developed VRIsys are used in systematic simulations to quantify the impact and interaction of various factors that could affect system strength. The assessment was conducted using time-domain simulation with direct connected induction motors (DCIMs) and a proliferation of converter-based technologies on both the generation and load sides, namely, NCGs and Variable Speed Drives (VSDs), respectively. © 2013 IEEE.
Impact of PV plant and load models on system strength and voltage recovery of power systems
- Alshareef, Abdulrhman, Shah, Rakibuzzaman, Mithulananthan, Nadarajah
- Authors: Alshareef, Abdulrhman , Shah, Rakibuzzaman , Mithulananthan, Nadarajah
- Date: 2020
- Type: Text , Conference proceedings
- Relation: 2nd International Conference on Smart Power and Internet Energy Systems, SPIES 2020; Bangkok, Thailand; 15th-18th September 2020 p. 263-268
- Full Text:
- Reviewed:
- Description: In recent years, non-conventional inverter-based sources, namely, wind, PV, and others have emerged as excellent alternatives to the traditional synchronous machine for power generation. It has also been reported that the so-called system strength may be reduced with high penetration of non-conventional generations (NCGs). A number of methods have been used to assess system strength which may not reflect the interdependency or reciprocal influence of various factors affecting it. This paper presents a thorough assessment to quantify the implications of and the interaction of various factors affecting system strength, with the voltage recovery index being used as a quantification tool. © 2020 IEEE.
- Authors: Alshareef, Abdulrhman , Shah, Rakibuzzaman , Mithulananthan, Nadarajah
- Date: 2020
- Type: Text , Conference proceedings
- Relation: 2nd International Conference on Smart Power and Internet Energy Systems, SPIES 2020; Bangkok, Thailand; 15th-18th September 2020 p. 263-268
- Full Text:
- Reviewed:
- Description: In recent years, non-conventional inverter-based sources, namely, wind, PV, and others have emerged as excellent alternatives to the traditional synchronous machine for power generation. It has also been reported that the so-called system strength may be reduced with high penetration of non-conventional generations (NCGs). A number of methods have been used to assess system strength which may not reflect the interdependency or reciprocal influence of various factors affecting it. This paper presents a thorough assessment to quantify the implications of and the interaction of various factors affecting system strength, with the voltage recovery index being used as a quantification tool. © 2020 IEEE.
Influence of induction motor in stability of power system with high penetration of large-scale PV
- Alshareef, Abdulrhman, Nadarajah, Mithulananthan, Shah, Rakibuzzaman
- Authors: Alshareef, Abdulrhman , Nadarajah, Mithulananthan , Shah, Rakibuzzaman
- Date: 2020
- Type: Text , Conference proceedings
- Relation: 2nd International Conference on Smart Power and Internet Energy Systems, SPIES 2020; Bangkok, Thailand; 15th-18th September 2020 p. 269-274
- Full Text:
- Reviewed:
- Description: Inverter-Based Energy Resources (IBERs) have become an ordinary portion of the generation mix in power systems. Furthermore, converter-based technology has come to dominate modern motor loads on the consumption side. This transition in components towards accommodating power electronic devices alters the dynamic response of the power system. This paper investigates the impact of these elements on the dynamic stability of the power system. Firstly, this study successes to optimize a suitable model for converter-based motor loads. Secondly, indices of transient and voltage stabilities are used to quantify the strength of the power system at different circumstances incorporating the induction motor loads. Finally, this analysis provides an insight into the mutual interactions between transient and voltage stabilities. It is concluded that converter-based motor loads improve the voltage recovery when compared with direct-connected induction motors. However, the system is vulnerable to transient stability with the proliferation of inverter-based motor loads when IBERs dominant in the generation mix. © 2020 IEEE.
- Authors: Alshareef, Abdulrhman , Nadarajah, Mithulananthan , Shah, Rakibuzzaman
- Date: 2020
- Type: Text , Conference proceedings
- Relation: 2nd International Conference on Smart Power and Internet Energy Systems, SPIES 2020; Bangkok, Thailand; 15th-18th September 2020 p. 269-274
- Full Text:
- Reviewed:
- Description: Inverter-Based Energy Resources (IBERs) have become an ordinary portion of the generation mix in power systems. Furthermore, converter-based technology has come to dominate modern motor loads on the consumption side. This transition in components towards accommodating power electronic devices alters the dynamic response of the power system. This paper investigates the impact of these elements on the dynamic stability of the power system. Firstly, this study successes to optimize a suitable model for converter-based motor loads. Secondly, indices of transient and voltage stabilities are used to quantify the strength of the power system at different circumstances incorporating the induction motor loads. Finally, this analysis provides an insight into the mutual interactions between transient and voltage stabilities. It is concluded that converter-based motor loads improve the voltage recovery when compared with direct-connected induction motors. However, the system is vulnerable to transient stability with the proliferation of inverter-based motor loads when IBERs dominant in the generation mix. © 2020 IEEE.
An analysis of autonomic nervous system fuctioning in panic disorder and its relation to negative affect / Marles E. Alvarenga
- Authors: Alvarenga, Marlies
- Date: 2002
- Type: Text , Thesis , PhD
- Full Text:
- Description: "The present studies investigated the issue of potential explanatory mechanisms for the observed association between panic disorder (PD) and the development of cardiovascular disease (CVD). Specifically, this research aimed to elucidate more clearly the contribution of psychological variables. physical processes and social relations to the onset of cardiopathology."
- Description: Doctor of Clinical Psychology
- Authors: Alvarenga, Marlies
- Date: 2002
- Type: Text , Thesis , PhD
- Full Text:
- Description: "The present studies investigated the issue of potential explanatory mechanisms for the observed association between panic disorder (PD) and the development of cardiovascular disease (CVD). Specifically, this research aimed to elucidate more clearly the contribution of psychological variables. physical processes and social relations to the onset of cardiopathology."
- Description: Doctor of Clinical Psychology
The global burden of adolescent and young adult cancer in 2019 : a systematic analysis for the Global Burden of Disease Study 2019
- Alvarez, Elysia, Force, Lisa, Xu, Rixing, Compton, Kelly, Lu, Dan, Henrikson, Hannah, Kocarnik, Jonathan, Harvey, James, Pennini, Alyssa, Dean, Frances, Fu, Weijia, Vargas, Martina, Keegan, Theresa, Ariffin, Hany, Barr, Ronald, Erdomaeva, Yana, Gunasekera, D. Sanjeeva, John-Akinola, Yetunde, Ketterl, Tyler, Kutluk, Tezer, Malogolowkin, Marcio, Mathur, Prashan, Radhakrishnan, Venkatraman, Ries, Lynn, Rodriguez-Galindo, Carlos, Sagoyan, Garik, Sultan, Iyad, Abbasi, Behzad, Abbasi-Kangevari, Mohsen, Rahman, Monsiur
- Authors: Alvarez, Elysia , Force, Lisa , Xu, Rixing , Compton, Kelly , Lu, Dan , Henrikson, Hannah , Kocarnik, Jonathan , Harvey, James , Pennini, Alyssa , Dean, Frances , Fu, Weijia , Vargas, Martina , Keegan, Theresa , Ariffin, Hany , Barr, Ronald , Erdomaeva, Yana , Gunasekera, D. Sanjeeva , John-Akinola, Yetunde , Ketterl, Tyler , Kutluk, Tezer , Malogolowkin, Marcio , Mathur, Prashan , Radhakrishnan, Venkatraman , Ries, Lynn , Rodriguez-Galindo, Carlos , Sagoyan, Garik , Sultan, Iyad , Abbasi, Behzad , Abbasi-Kangevari, Mohsen , Rahman, Monsiur
- Date: 2022
- Type: Text , Journal article
- Relation: The Lancet Oncology Vol. 23, no. 1 (2022), p. 27-52
- Full Text:
- Reviewed:
- Description: Background: In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15–39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods: Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15–39 years to define adolescents and young adults. Findings: There were 1·19 million (95% UI 1·11–1·28) incident cancer cases and 396 000 (370 000–425 000) deaths due to cancer among people aged 15–39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59·6 [54·5–65·7] per 100 000 person-years) and high-middle SDI countries (53·2 [48·8–57·9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14·2 [12·9–15·6] per 100 000 person-years) and middle SDI (13·6 [12·6–14·8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23·5 million (21·9–25·2) DALYs to the global burden of disease, of which 2·7% (1·9–3·6) came from YLDs and 97·3% (96·4–98·1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation: Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Funding: Bill & Melinda Gates Foundation, American Lebanese Syrian Associated Charities, St Baldrick's Foundation, and the National Cancer Institute. © 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. **Please note that there are multiple authors for this article therefore only the name of the first 30 including Federation University Australia affiliate “Rahman, Monsiur" are provided in this record**
- Authors: Alvarez, Elysia , Force, Lisa , Xu, Rixing , Compton, Kelly , Lu, Dan , Henrikson, Hannah , Kocarnik, Jonathan , Harvey, James , Pennini, Alyssa , Dean, Frances , Fu, Weijia , Vargas, Martina , Keegan, Theresa , Ariffin, Hany , Barr, Ronald , Erdomaeva, Yana , Gunasekera, D. Sanjeeva , John-Akinola, Yetunde , Ketterl, Tyler , Kutluk, Tezer , Malogolowkin, Marcio , Mathur, Prashan , Radhakrishnan, Venkatraman , Ries, Lynn , Rodriguez-Galindo, Carlos , Sagoyan, Garik , Sultan, Iyad , Abbasi, Behzad , Abbasi-Kangevari, Mohsen , Rahman, Monsiur
- Date: 2022
- Type: Text , Journal article
- Relation: The Lancet Oncology Vol. 23, no. 1 (2022), p. 27-52
- Full Text:
- Reviewed:
- Description: Background: In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15–39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods: Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15–39 years to define adolescents and young adults. Findings: There were 1·19 million (95% UI 1·11–1·28) incident cancer cases and 396 000 (370 000–425 000) deaths due to cancer among people aged 15–39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59·6 [54·5–65·7] per 100 000 person-years) and high-middle SDI countries (53·2 [48·8–57·9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14·2 [12·9–15·6] per 100 000 person-years) and middle SDI (13·6 [12·6–14·8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23·5 million (21·9–25·2) DALYs to the global burden of disease, of which 2·7% (1·9–3·6) came from YLDs and 97·3% (96·4–98·1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation: Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Funding: Bill & Melinda Gates Foundation, American Lebanese Syrian Associated Charities, St Baldrick's Foundation, and the National Cancer Institute. © 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. **Please note that there are multiple authors for this article therefore only the name of the first 30 including Federation University Australia affiliate “Rahman, Monsiur" are provided in this record**
Exploring the Dynamic Voltage Signature of Renewable Rich Weak Power System
- Alzahrani, S., Shah, Rakibuzzaman, Mithulananthan, N.
- Authors: Alzahrani, S. , Shah, Rakibuzzaman , Mithulananthan, N.
- Date: 2020
- Type: Text , Journal article
- Relation: IEEE Access Vol. 8, no. (2020), p. 216529-216542
- Full Text:
- Reviewed:
- Description: Large-scale renewable energy-based power plants are becoming attractive technically and economically for generation mix around the world. Nevertheless, network operation has significantly changed due to the rapid integration of renewable energy in supply side. The integration of more renewable resources, especially inverter-based generation, deteriorates power system resilience to disturbances and substantially affects stable operations. The dynamic voltage stability becomes one of the major concerns for the transmission system operators (TSOs) due to the limited capabilities of inverter-based resources (IBRs). A heavily loaded and stressed renewable rich grid is susceptible to fault-induced delayed voltage recovery. Hence, it is crucial to examine the system response upon disturbances, to understand the voltage signature, to determine the optimal location and sizing of grid-connected IBRs. Moreover, the IBRs fault contribution mechanism investigation is essential in adopting additional grid support devices, control coordination, and the selection of appropriate corrective control schemes. This article utilizes a comprehensive assessment framework to assess power systems' dynamic voltage signature with large-scale PV under different realistic operating conditions. Several indices quantifying load bus voltage recovery have been used to explore the system' s steady-state, transient response, and voltage trajectories. The recovery indices help extricate the signature and influence of IBRs. The proposed framework's applicability is carried out on the New England IEEE-39 bus test system using the DIgSILENT platform. © 2013 IEEE.
- Authors: Alzahrani, S. , Shah, Rakibuzzaman , Mithulananthan, N.
- Date: 2020
- Type: Text , Journal article
- Relation: IEEE Access Vol. 8, no. (2020), p. 216529-216542
- Full Text:
- Reviewed:
- Description: Large-scale renewable energy-based power plants are becoming attractive technically and economically for generation mix around the world. Nevertheless, network operation has significantly changed due to the rapid integration of renewable energy in supply side. The integration of more renewable resources, especially inverter-based generation, deteriorates power system resilience to disturbances and substantially affects stable operations. The dynamic voltage stability becomes one of the major concerns for the transmission system operators (TSOs) due to the limited capabilities of inverter-based resources (IBRs). A heavily loaded and stressed renewable rich grid is susceptible to fault-induced delayed voltage recovery. Hence, it is crucial to examine the system response upon disturbances, to understand the voltage signature, to determine the optimal location and sizing of grid-connected IBRs. Moreover, the IBRs fault contribution mechanism investigation is essential in adopting additional grid support devices, control coordination, and the selection of appropriate corrective control schemes. This article utilizes a comprehensive assessment framework to assess power systems' dynamic voltage signature with large-scale PV under different realistic operating conditions. Several indices quantifying load bus voltage recovery have been used to explore the system' s steady-state, transient response, and voltage trajectories. The recovery indices help extricate the signature and influence of IBRs. The proposed framework's applicability is carried out on the New England IEEE-39 bus test system using the DIgSILENT platform. © 2013 IEEE.
Examination of effective VAr with respect to dynamic voltage stability in renewable rich power grids
- Alzahrani, Saeed, Shah, Rakibuzzaman, Mithulananthan, N.
- Authors: Alzahrani, Saeed , Shah, Rakibuzzaman , Mithulananthan, N.
- Date: 2021
- Type: Text , Journal article
- Relation: IEEE Access Vol. 9, no. (2021), p. 75494-75508
- Full Text:
- Reviewed:
- Description: High penetrations of inverter-based renewable resources (IBRs) diminish the resilience that traditional power systems had due to constant research and developments for many years. In particular, dynamic voltage stability becomes one of the major concerns for transmission system operators due to the limited capabilities of IBRs (i.e., voltage and frequency regulation). A heavily loaded renewable-rich network is susceptible to fault-induced delayed voltage recovery (FIDVR) due to insufficient effective reactive power (E-VAr) in power grids. Hence, it is crucial to thoroughly scrutinize each VAr resources' participation in E-VAr under various operating conditions. Moreover, it is essential to investigate the influence of E-VAr on system post-fault performance. The E-VAr investigation would help in determining the optimal location and sizing of grid-connected IBRs and allow more renewable energy integration. Furthermore, it would enrich decision-making about adopting additional grid support devices. In this paper, a comprehensive assessment framework is utilized to assess the E-VAr of a power system with a large-scale photovoltaic power. Plant under different realistic operating conditions. Several indices quantifying the contribution of VAr resources and load bus voltage recovery assists to explore the transient response and voltage trajectories. The recovery indices help have a better understanding of the factors affecting E-VAr. The proposed framework has been tested in the New England (IEEE 39 bus system) through simulation by DIgSILENT Power Factory. © 2013 IEEE.
Examination of effective VAr with respect to dynamic voltage stability in renewable rich power grids
- Authors: Alzahrani, Saeed , Shah, Rakibuzzaman , Mithulananthan, N.
- Date: 2021
- Type: Text , Journal article
- Relation: IEEE Access Vol. 9, no. (2021), p. 75494-75508
- Full Text:
- Reviewed:
- Description: High penetrations of inverter-based renewable resources (IBRs) diminish the resilience that traditional power systems had due to constant research and developments for many years. In particular, dynamic voltage stability becomes one of the major concerns for transmission system operators due to the limited capabilities of IBRs (i.e., voltage and frequency regulation). A heavily loaded renewable-rich network is susceptible to fault-induced delayed voltage recovery (FIDVR) due to insufficient effective reactive power (E-VAr) in power grids. Hence, it is crucial to thoroughly scrutinize each VAr resources' participation in E-VAr under various operating conditions. Moreover, it is essential to investigate the influence of E-VAr on system post-fault performance. The E-VAr investigation would help in determining the optimal location and sizing of grid-connected IBRs and allow more renewable energy integration. Furthermore, it would enrich decision-making about adopting additional grid support devices. In this paper, a comprehensive assessment framework is utilized to assess the E-VAr of a power system with a large-scale photovoltaic power. Plant under different realistic operating conditions. Several indices quantifying the contribution of VAr resources and load bus voltage recovery assists to explore the transient response and voltage trajectories. The recovery indices help have a better understanding of the factors affecting E-VAr. The proposed framework has been tested in the New England (IEEE 39 bus system) through simulation by DIgSILENT Power Factory. © 2013 IEEE.
Dynamic voltage signature of large scale PV enriched streesed power system
- Alzahrani, Saeed, Shah, Rakibuzzaman, Mithulananthan, Nadarajah, Sode-Yome, Arthit
- Authors: Alzahrani, Saeed , Shah, Rakibuzzaman , Mithulananthan, Nadarajah , Sode-Yome, Arthit
- Date: 2020
- Type: Text , Conference proceedings
- Relation: 2nd International Conference on Smart Power and Internet Energy Systems, SPIES 2020; Bangkok, Thailand; 15th-18th September 2020 p. 275-280
- Full Text:
- Reviewed:
- Description: Renewable power generations including flexible demand and energy storage systems leverage significant changes in network operation. Thereby, power systems with high renewable penetration manifest deteriorated resilience to disturbances. Hence, the stable operation of the system could be affected. With a paradigm shift, dynamic voltage stability becomes one of the major concerns for the transmission system operators (TSOs). Predicting the dynamic voltage signature for the transmission system with high penetration of renewables is essential to assist in selecting appropriate corrective control. This paper utilized a comprehensive assessment framework to identify the dynamic voltage signature of the power system with PV and various loads. The voltage recovery index has been chosen as the quantifiable index to extricate the dynamic voltage signature. The applicability of the proposed framework is discussed using simulation studies on the IEEE-39 bus test system. © 2020 IEEE.
- Authors: Alzahrani, Saeed , Shah, Rakibuzzaman , Mithulananthan, Nadarajah , Sode-Yome, Arthit
- Date: 2020
- Type: Text , Conference proceedings
- Relation: 2nd International Conference on Smart Power and Internet Energy Systems, SPIES 2020; Bangkok, Thailand; 15th-18th September 2020 p. 275-280
- Full Text:
- Reviewed:
- Description: Renewable power generations including flexible demand and energy storage systems leverage significant changes in network operation. Thereby, power systems with high renewable penetration manifest deteriorated resilience to disturbances. Hence, the stable operation of the system could be affected. With a paradigm shift, dynamic voltage stability becomes one of the major concerns for the transmission system operators (TSOs). Predicting the dynamic voltage signature for the transmission system with high penetration of renewables is essential to assist in selecting appropriate corrective control. This paper utilized a comprehensive assessment framework to identify the dynamic voltage signature of the power system with PV and various loads. The voltage recovery index has been chosen as the quantifiable index to extricate the dynamic voltage signature. The applicability of the proposed framework is discussed using simulation studies on the IEEE-39 bus test system. © 2020 IEEE.