78 research outputs found
Traveling Wave Based Fault Location
No full textFull text is available to authenticated members of The University of Auckland only.Transmission grid system plays a key role in the interconnection of large-scale generation of a country’s power system network supplying loads all across. In many faults statistics, it has been unambiguously indicated that around 75% power system faults occur in transmission lines. This fact has increased the need for correct fault identification and location on transmission lines. Many researchers have developed algorithms based on using current, voltage measurements, and line parameters at a single end or multi-end to locate the fault. However, each of these fault location technique has some operational limitation. This thesis presents single-ended traveling wave fault location method based on wavelet transform and practical implementation on a recently released commercial relay utilizing this principle. A sample system was created in MATLAB SimPower System and simulations carried out for assessing the traveling wave from one end for different fault distance on the transmission lines. Traveling wave propagate close to the velocity of light and it is difficult to capture them so sampling rate was kept high enough to record the traveling wave at fault point. In order to decouple three phases, modal transformation is used to carry the independent analysis of each phase. Signal processing application wavelet transform has been used for feature extraction. MATLAB wavelet toolbox is used to decompose the signal by using discrete wavelet transform with appropriate mother wavelet Daubechies at level one which yields detail coefficient and approximation coefficients. Thereafter, Wavelet transform modulus maxima of detail coefficient is used to extract the sample number of the peaks in the signal. Firstly, two consecutive peaks with their respective sample numbers are used along with the velocity of propagation. Sensitivity analysis is carried out to analyse the system performance under different conditions. Extensive simulations are performed by varying the fault inception angle, fault resistance and mother wavelets showing that the traveling wave fault location method is insensitive to these parameters. All the simulations were performed by keeping the sample rate higher since by keeping sampling rate lower it is not possible to capture the realistic traveling wave which thereby impacts on the performance of any practical relay being tested. In addition to this detailed research assessment carried out, a two bus system network has been modelled using ATP/EMTP and the generated fault signal applied to a new commercial relay (M/s Schweitzer Engineering Laboratories, SEL) using a commercial testing system. By use of synchrowave event software, the fault signal is analysed and the fault distance manually calculated. The average error was around 2% for fault location but relay trip indicated correct fault classification. Analysing the various fault cases it is clearly observed that it is difficult to distinguish between the waves reflected from fault point and from the remote end of the line. This is one limitation of traveling wave fault location method. Low sampling rate and velocity of propagation appear to affect the observed results. The velocity of propagation should be calculated by using the line parameters of the transmission line and sampling rate should be kept higher to get estimated results from modelling. In future, this particular relay should be tested in the field by using the double-ended traveling wave fault location method
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Making It Work for Them: A Technology-Enhanced Educational Innovation in Pakistan
No full textMillions of dollars are spent every year to plan and introduce educational innovation initiatives in the developing world with the hope of bringing about economic development, social progress, and educational reform (Kozma, 2008; Kombe, 2016). But the challenges with introducing and maintaining any educational innovation are multifold in developing countries, which are plagued by economic instability and a lack of resources. This situation worsens when the innovation involves any form of technology. The end result in most technology enhanced educational innovations (TEEIs) in such contexts is disillusionment -- either because expected outcomes have not been met or the positive impact is not sustainable. This disillusionment is usually caused by multiple gaps in the planning and implementation of the innovation or the unrealistic expectation that technology is the panacea of all ills. Studies on educational innovation endeavors (Vergara & Grazzi, 2008; Jhurree, 2005; Kozma & Vota, 2014) have identified a significant lack of research in developing countries. Building on these concerns, this dissertation is a qualitative introspective case study exploring different perspectives of the various change agents (Fullan, 2016; Rogers, 2003) involved in facilitating a TEEI project in Pakistan, namely Digital Hall Study (DiSH). Combining the experiences of these change agents, the study attempts to improve understanding of the factors that facilitate and/or hinder the process of designing, planning, implementing, adopting, and sustaining a TEEI project in the low resource educational settings of developing countries like Pakistan. Findings have shown four categories of factors that influence TEEI by offering support and posing challenges to the implementers and users: social context-based, institution-based, teacher-based, and innovation project-based factors. This study has also demonstrated that reevaluating the innovation process in TEEI projects is essential to ensure that needs analyses are conducted before those projects are designed
Coping Strategies of Nursing Student Against Academic and Clinical Stress at Public Sector Lahore
Get PDFBackground: Nursing is an emotionally demanding and a highly stressful profession as nurses has to deal with different people, in various situations and different times of the day. During their everyday work, they have to cope with extremely emotionally charged and rapidly changing circumstances (Forouzanfar et al., 2015). It is a universally accepted fact that human nature is prone to wears and tears associated with daily activities. These manifest in the form of stress and strains as witnessed in everyday life. Nurses and other healthcare professionals are exposed on daily basis to different levels of stress and burnout arising from the demand for their jobs(Roberts & Grubb1, 2014).Objectives: To explore the coping strategies of nursing student against clinical and academic stress.Methodology: A quantitative, descriptive cross-sectional study design was used to explore coping strategies of nursing students against academic and clinical stress at public hospital Lahore. The instrument use for the data collection was adopted questioner and convenient sampling technique was used.Results: The mean difference is significant at the 0.05 level. It is observed that academic and clinical stress sources and coping mechanisms are statistically significant, as p-value < 0.05.Conclusion: The present study was considered as a cornerstone that gives strong support towards coping strategies of nursing student against academic and clinical stress. It highlighted there are number of clinical and academic stress that hinder good performance of student. These results substantiate the belief that aspects of the practice environment affect student nurse academic performance and most importantly, the quality of care delivered on clinical placement to the patien
Exploring Convolutional Neural Network Architectures for Image Classification: A Comprehensive Analysis and Implications for Deep Learning Applications
No full textEngineering of P450cam for fine chemical synthesis
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Need Assessment for Integrating Self-Regulation Practice in Teaching and Learning of English at Secondary School level in Islamabad, Pakistan
Get PDFThis research attempts to assess the current knowledge and practices of students and teachers regarding the use of Self-Regulated Learning (SRL) in urban secondary schools of Islamabad. In the context of secondary school English learning, the study specifically examines the use of SRL strategies employed by low-achieving students in their learning endeavours and the role of teachers in promoting SRL among their students. It is a mixed-methods approach that combines qualitative data from structured interviews with quantitative evaluation through a rubric-based scoring system. A total of 40 low-achieving students and 20 English teachers from 10 randomly selected schools participated in the study. The low achievers scored poorly across all six SRL domains, showing significant deficiencies in using SRL strategies. Teacher interviews indicated that while lesson planning was somewhat effective, there were notable gaps in providing guidance for homework and guidance for improving students\u27 performance. These findings emphasise the need for targeted interventions to enhance SRL among low-achieving students and highlight the importance of professional development for teachers to support student self-regulation better. This study calls for comprehensive SRL integration into student learning strategies and teacher training to improve academic outcomes in English learning at the secondary level in Islamabad
Level of awareness on environment and energy; a survey of the freshmen at Habib University
No full textBehavioral, Cognitive, and Biochemical Consequences of Early Life Stress in Later Life: Insights from an Animal Model
No full textAdverse experiences during early life contribute to the development of psychiatric conditions in later life. In fact, young children who directly experience or witness traumatic event(s) during early life, a sensitive developmental period, are considered highly vulnerable to psychiatric disorders during adult life. Interestingly, not all children who experience traumatic events are equally at risk of developing later life psychiatric disorders. Some are resilient despite being exposed to the same risk factors, while others are susceptible. The relationship between early life trauma exposure and development of later life psychiatric symptoms is not fully understood, and the mechanistic basis for resilience is also not clear. Clinical and preclinical studies have suggested that defects in stress-adaptive mechanisms potentially contribute to etiology of later life psychiatric conditions. Preclinical data from our laboratory has indicated poor oxidative/antioxidative balance as a critical component of maladaptive stress responsiveness in rodents. Our published work has demonstrated that induction of psychological stress leads to behavioral and cognitive deficits in rats. These impairments correlate with an increase in oxidative stress markers in the periphery as well as in selected regions of the brain including the hippocampus, amygdala, and the prefrontal cortex. Moreover, heightened oxidative stress was associated with decreased levels of key antioxidant enzymes. It seems like that early life stress causes behavioral and cognitive deficits via an oxidative stress-mediated weakening of neuronal connections.
The central hypothesis of this Dissertation is that the ability to acquire susceptibility or resistance to stress-induced behavioral and cognitive deficits resides in oxidative-antioxidative balance within the CNS. This balance is maintained by transcriptional and epigenetic mechanisms. Therefore, our long-term goal is to investigate a) the role of early life stress on behavior and cognition across different ages in rats, b) reveal resilience and susceptible phenotypes and c) to identify the role of oxidative mechanisms in the regulation of behavioral and cognitive function and resilience. We propose to utilize a comprehensive approach to address our goals.
In Aim 1, the effect of induction of early life trauma was examined using a rat model of early-life stress on later life behaviors. Sprague Dawley (SD) rats were exposed to single prolonged stress (SPS) at postnatal day (PND) 25. Behavior tests to assess anxiety-like behavior, depression-like behavior, and learning and memory function were performed at different stages of development during PND 32, 60 and 90. Resilience and susceptibility phenotypes also were examined. In Aim 2 we examined the effect of early life stress on oxidative stress mechanisms as well as transcriptional and epigenetic regulation of specific genes that presumably control antioxidative capacity. We focused explicitly on Keap1-Nrf2 and NF-κB pathway. SD rats were exposed to SPS at PND25. One group of rats were sacrificed at PND32, the other group of rats was sacrificed at PND90. Blood was collected, and plasma was used to examine systemic markers of oxidative stress and physiological stress. Brains were harvested, and specific brain areas were isolated, and homogenates were prepared for conducting biochemical analysis to determine the effect of early life SPS on oxidative-antioxidant balance, and activation of redox-sensitive pathways such as Nrf2 and NF-κB pathways. Studies proposed in aim 1 revealed that rats exposed to SPS exhibited both anxiety- and depression-like behavior at PND32. Moreover, short-term (STM) but not long-term memory (LTM) was impaired. Rats exposed to SPS at PND60 exhibited anxiety- but not depression-like behavior. STM but not LTM was impaired. Rats exposed to SPS at PND90 exhibited fearful (as indicated by elevated plus maze test) but not an overall anxiety-like behavior (in light and dark test). These rats also displayed significant depression-like behavior with no changes in STM or LTM. Interestingly, when data was further analyzed, two subsets of PND90 rats exposed to SPS were identified, “susceptible”: with depression-like behavior and “resilient”: without depression-like behavior. Importantly, while resilient group expressed early signs of anxiety- (at PND32 and PND60) and depression-like behavior (at PND32), these behavioral deficits were absent at PND90. On the other hand, susceptible PND90 rats exposed to SPS expressed later onset of anxiety-like behavior (at PND60), while depression-like phenotype was evident only later on at PND90. At the biochemical level, SPS exposure at PND25 led to an increase in oxidative stress in specific regions of the brain (pre-frontal cortex), as indicated by the increased level of oxidative stress marker at PND32 and PND90. SPS exposure at PND25 also led to an initial increase in antioxidant enzyme expression at PND32 and a decrease in antioxidant enzyme expression at PND90. The increase in oxidative stress and the decrease in antioxidant enzymes at PND90 correlates with the depressive phenotypes in SPS rats at PND90. Further biochemical studies revealed a state of a compromised Nrf2 pathway and activated NF-κB pathway in the pre-frontal cortex (PFC) homogenates. The state of compromised Nrf2 pathway and activated NF-κB pathway was indicated by a decrease in the levels of Nrf2 and increased levels of NF-κB, as well as NF-κB-mediated increased levels of interleukin-6 (IL-6) and tumor necrosis factor α (TNFα) in PFC.
In summary, our findings suggest that early life stress caused co-occurrence of anxiety and depression-like behavior at PND32 (mimics human early-adolescent period). This co-occurrence was lost at PND60 with a demonstration of anxiety- but not depression-like behavior. Later, depression but not the anxiety-like behavior was observed at PND90. It seems that behavioral adaptations occur at the critical PND60 stage (mimics human late-adolescent period) (Sengupta 2013), where behavioral and cognitive switching occurs, thereby, expressing susceptible and resilient phenotypes. Moreover, susceptible phenotype correlates with an increase in oxidative stress and a decrease in antioxidant enzymes in the emotion-regulating brain region of the PFC. The correlation between susceptible phenotype and increased oxidative stress markers suggests that the early life stress causes a buildup of oxidative stress, which negatively affects neuronal circuitry that contributes to depressive phenotypes. The increase in oxidative stress induced by early life stress activates NF-κB pathway, which triggers cellular inflammatory responses.Pharmacological and Pharmaceutical Sciences, Department o
Left out: essays on suburbia
Get PDFThis collection of essays examines the aesthetic of uniformity and order prevalent in planned, suburban housing developments. It utilizes both personal experience and research to examine the effect this aesthetic has on the suburbanite. It relates stories from the author�s childhood that attempt to illustrate the homogenizing effects of the suburban aesthetic and relates the author�s current sensibilities, attempting to relate them to his upbringing.Autobiographical essays
عنایت اللہ مشرقی اور ڈارون کا نظریہ ارتقاء: Inayat Ullah al-Mashriqi and Darwin’s Theory of Evolution
No full textThere are two major influential and prominent theories about the origin of life in this universe: One is theistic theory of “Divine Creation” or “Intelligent Design” which emphasizes that there is a “Supernatural Power” or an “Intelligent Designer” Who has created this universe along with all its living creatures including human beings.
The other theory is based on atheistic approach of Darwinism. It asserts that all living beings have a common, individual ancestor. Life was emerged in simple organism in the sea by the process of evolution and it evolved and diversified into different species which finally culminated in man various epochal times.
During this era, only those species survived who adapted to their environment.
Inayatullah Mashriqi has advocated this theory of Darwin and claimed it as “the climax of human knowledge”. In his re-markable book “Tazkira”, he insists that by following the Darwin’s concept of “Survival for the Fittest”, Man can not only touch the apex of humanity but also share “Godly Features and Traits”.
This theory basically denies God as the Creator and Originator of the universe and its creation. It also opens the new ways of false interpretations and suppositions in Quran which influence the young minds of new generation in a wrong direction. That’s why I feel a need to analyze these aspects of Allama Mashraqi’s concept to eradicate these delusions and fallacies.
 
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