Search results for: density function theory

Authors: Rakibul Islam Sagor, Sadia Ibnat Raisa

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Many nations across the globe, including Dhaka, are facing challenges in meeting the needs for a satisfactory quality of life due to the combination of a growing population and limited land resources. As a result, maximum spaces in modern cities are engulfed by concrete infrastructure, and there are hardly any open spaces in the urban neighborhoods. Although vertical movement has predominantly been employed for residential and commercial applications, the notion of vertical recreational and sports facilities remains unsettled. The primary objective of this study is to explore the feasibility of implementing vertical adaptations in urban recreational spaces, drawing upon the principles of high-rise theory. This article presents an analysis of the open spaces in Gulshan, Dhaka, focusing on the evaluation of the demand for open recreational and sports facilities that adequately cater to the existing population of the region. Initially, the study tried to identify and examine all potential open spaces within the designated area. Following that, an acceptable place is selected utilizing space syntax analysis, which takes into account the most conveniently accessible space for social interactions in the neighborhood. In addition, socioeconomic conditions of the area have been studied in order to determine the feasibility of the area. Finally, the study presented viable options for vertical urban sports facilities in the context of Dhaka, Bangladesh. Additionally, it seeks to develop strategies for maximizing the use of vertical expansions, thereby promoting a healthier and more active lifestyle among the city's residents. This approach aims to effectively handle the issue of limited land availability and enhance the efficiency of recreational areas around the globe.

Keywords: vertical sports, urban open spaces, social interaction, recreational activities

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Authors: Kurniawan Adha, Wan Ismail Wan Yusoff, Luluan Almanna Lubis

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Preventing hazardous events during oil and gas operation is an important contribution of accurate pore pressure data. The availability of pore pressure data also contribute in reducing the operation cost. Suggested methods in pore pressure estimation were mostly complex by the many assumptions and hypothesis used. Basic properties which may have significant impact on estimation model are somehow being neglected. To date, most of pore pressure determinations are estimated by data model analysis and rarely include laboratory analysis, stratigraphy study or core check measurement. Basically, this study developed a model that might be applied to investigate the changes of pore pressure and effective stress due to hydrocarbon production. In general, this paper focused velocity model effect of pore pressure and effective stress changes due to hydrocarbon production with illustrated by changes in saturation. The core samples from Miri field from Sarawak Malaysia ware used in this study, where the formation consists of sandstone reservoir. The study area is divided into sixteen (16) layers and encompassed six facies (A-F) from the outcrop that is used for stratigraphy sequence model. The experimental work was firstly involving data collection through field study and developing stratigraphy sequence model based on outcrop study. Porosity and permeability measurements were then performed after samples were cut into 1.5 inch diameter core samples. Next, velocity was analyzed using SONIC OYO and AutoLab 500. Three (3) scenarios of saturation were also conducted to exhibit the production history of the samples used. Results from this study show the alterations of velocity for different saturation with different actions of effective stress and pore pressure. It was observed that sample with water saturation has the highest velocity while dry sample has the lowest value. In comparison with oil to samples with oil saturation, water saturated sample still leads with the highest value since water has higher fluid density than oil. Furthermore, water saturated sample exhibits velocity derived parameters, such as poisson’s ratio and P-wave velocity over S-wave velocity (Vp/Vs) The result shows that pore pressure value ware reduced due to the decreasing of fluid content. The decreasing of pore pressure result may soften the elastic mineral frame and have tendency to possess high velocity. The alteration of pore pressure by the changes in fluid content or saturation resulted in alteration of velocity value that has proportionate trend with the effective stress.

Keywords: pore pressure, effective stress, production, miri formation

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Authors: Sa'ad M. Ismail, Hung-Hsun Yen, Christina M. Murray, Helen M. S. Davies

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In the dog, the median sacral crest is formed by the fusion of three sacral spinous processes. In greyhounds with standard sacrums, this fusion in the median sacral crest consists of the fusion of three sacral spinous processes while it consists of four in greyhounds with sacrocaudal fusion. In the present study, variations in the angulation of the first sacral spinous process in association with different types of sacrocaudal fusion in the greyhound were investigated. Sacrums were collected from 207 greyhounds (102 sacrums; type A (unfused) and 105 with different types of sacrocaudal fusion; types: B, C and D). Sacrums were cleaned by boiling and dried and then were placed on their ventral surface on a flat surface and photographed from the left side using a digital camera at a fixed distance. The first sacral spinous process angle (1st SPA) was defined as the angle formed between the cranial border of the cranial ridge of the first sacral spinous process and the line extending across the most dorsal surface points of the spinous processes of the S1, S2, and S3. Image-Pro Express Version 5.0 imaging software was used to draw and measure the angles. Two photographs were taken for each sacrum and two repeat measurements were also taken of each angle. The mean value of the 1st SPA in greyhounds with sacrocaudal fusion was less (98.99°, SD ± 11, n = 105) than those in greyhounds with standard sacrums (99.77°, SD ± 9.18, n = 102) but was not significantly different (P < 0.05). Among greyhounds with different types of sacrocaudal fusion the mean value of the 1st SPA was as follows: type B; 97.73°, SD ± 10.94, n = 39, type C: 101.42°, SD ± 10.51, n = 52, and type D: 94.22°, SD ± 11.30, n = 12. For all types of fusion these angles were significantly different from each other (P < 0.05). Comparing the mean value of the1st SPA in standard sacrums (Type A) with that for each type of fusion separately showed that the only significantly different angulation (P < 0.05) was between standard sacrums and sacrums with sacrocaudal fusion sacrum type D (only body fusion between the S1 and Ca1). Different types of sacrocaudal fusion were associated with variations in the angle of the first sacral spinous process. These variations may affect the alignment and biomechanics of the sacral area and the pattern of movement and/or the force produced by both hind limbs to the cranial parts of the body and may alter the loading of other parts of the body. We concluded that any variations in the sacrum anatomical features might change the function of the sacrum or surrounding anatomical structures during movement.

Keywords: angulation of first sacral spinous process, biomechanics, greyhound, locomotion, sacrocaudal fusion

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Authors: Suleyman Karabal, Timothy L. Burnett, Egemen Avcu, Andrew H. Sherry, Philip J. Withers

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SA508 Grade 3 steel is widely used in the construction of nuclear pressure vessels, where its fracture toughness plays a critical role in ensuring operational safety and reliability. Understanding the ductile failure mechanisms in this steel grade is crucial for designing robust pressure vessels that can withstand severe nuclear environment conditions. In the present study, round bar specimens of SA508 Grade 3 steel with four distinct notch geometries were subjected to tensile loading while capturing continuous 2D images at 5-second intervals in order to monitor any alterations in their geometries to construct true stress-strain curves of the specimens. 3D reconstructions of X-ray computed tomography (CT) images at high-resolution (a spatial resolution of 0.82 μm) allowed for a comprehensive assessment of the influences of second-phase particles (i.e., manganese sulfide inclusions and cementite particles) on ductile failure initiation as a function of applied plastic strain. Additionally, based on 2D and 3D images, plasticity modeling was executed, and the results were compared to experimental data. A specific ‘two-parameter criterion’ was established and calibrated based on the correlation between stress triaxiality and equivalent plastic strain at failure initiation. The proposed criterion demonstrated substantial agreement with the experimental results, thus enhancing our knowledge of ductile fracture behavior in this steel grade. The implementation of X-ray CT and fractography analysis provided new insights into the diverse roles played by different populations of second-phase particles in fracture initiation under varying stress triaxiality conditions.

Keywords: ductile fracture, two-parameter criterion, x-ray computed tomography, stress triaxiality

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Authors: Israel Oguche

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Journalism practice has faced several challenges across the globe, particularly in developing countries such as Nigeria. While Nigeria has thrived under democratic experiment for twenty years since the return to democracy in 1999, there is still a great lacuna in freedom of expression, such that the presidents, though elected democratically, have had the tendencies to use military might in clamping down on journalism practices across the country. Under Muhammadu Buhari, it seems Nigeria has returned to the military era when powers were used against who says what, on a media, so today, in Nigeria, there are obvious cases of outright human rights violations and detention of journalists whose offenses were not spelled out. From Abiri Jones to Abba Jalingo and Omoyele Sowore, Nigeria journalists have been placed under the cocoon of the tyrannical administration of Muhammadu Buhari, the president, with subsequent clamping down on the instruments of freedoms such as access to justice and fair hearing. This paper gave vivid analytical and empirical perspectives of journalism practice under the dark days of Muhammadu Buhari as Nigeria’s president. The objectives include; examining the core cases of attacks on journalists since 2015 to date, determining the burden of practicing journalism in a tyrannical government, reeling out the effects of restrictive practices of journalism on freedom of expression among Nigerians and proffering solutions for improvement in the years ahead. Using the cognitive dissonance theory, the survey method was used for the study, with qualitative research analysis as a tool for data presentation. In the findings, the number of journalists in jail for publishing objectively under the Buhari administration remains high while the government has clamped down on freedom of expression among the people. The study concluded that there is a need for repelling of laws made by the Nigeria government in order to save the Nigerian journalism industry from total collapse.

Keywords: communication, developing democracy, press freedom, journalism practices

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Authors: Ramy Bakir

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Advancements in the field of nanoscience and nanotechnology have had a sweeping effect on the manufacturing industry in the last two decades, and have specifically allowed for the enhancement of a multitude of applications in the field of building technology. Research carried out in the architectural field in the past decade highlights how those enhancements have improved the structural and environmental performance of buildings, and/or how they developed the aesthetic value of façade or interior treatments. In developing countries, such as Egypt, the actual use of those nano-enhanced applications and their benefits rarely manifest. Hence this paper investigates the socio-technical relationship between the architectural design process and nanotechnology in Cairo using participant observation within an ethnographic study. The study focused on the socio-cultural context of an environmental design process in a specific design firm, and the role of nano-enhanced applications in it, and provided a thick description of the design decisions made within the preliminary stages of the design process of a residential building in Cairo, Egypt. Using Grounded Theory, and through the analysis and coding of the qualitative data collected, this paper was able to identify specific socio-cultural issues influencing individual architect cognition, clarifying how the context of the design process of the studied project affected the design team members’ responses to nano-enhanced materials. This paper presents those findings within a framework of the three identified statuses of response to nanotechnology and classifies the socio-cultural reasons influencing them. In doing so, the paper aims to shed more light on the relation between nanotechnology and architects in their natural environment, and hence allow both to benefit more from a clearer understanding of how the socio-cultural context, along with the benefits of using nanotechnology, influences the design decisions made.

Keywords: nanotechnology, design process, socio-cultural context, nano-enhanced applications

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Authors: Lovorka Galetic, Zeljko Vukelic

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The advanced concepts of strategic and innovation management in the sphere of company dynamic and innovation capabilities, and achieving their mutual alignment and a synergy effect, are important elements in business today. This paper analyses the theory and empirically investigates the influence of a company’s dynamic capabilities on its innovation capabilities. A new multidimensional model of dynamic capabilities is presented, consisting of five factors appropriate to real time requirements, while innovation capabilities are considered pursuant to the official OECD and Eurostat standards. After examination of dynamic and innovation capabilities indicated their theoretical links, the empirical study testing the model and examining the influence of a company’s dynamic capabilities on its innovation capabilities showed significant results. In the study, a research model was posed to relate company dynamic and innovation capabilities. One side of the model features the variables that are the determinants of dynamic capabilities defined through their factors, while the other side features the determinants of innovation capabilities pursuant to the official standards. With regard to the research model, five hypotheses were set. The study was performed in late 2014 on a representative sample of large and very large Croatian enterprises with a minimum of 250 employees. The research instrument was a questionnaire administered to company top management. For both variables, the position of the company was tested in comparison to industry competitors, on a fivepoint scale. In order to test the hypotheses, correlation tests were performed to determine whether there is a correlation between each individual factor of company dynamic capabilities with the existence of its innovation capabilities, in line with the research model. The results indicate a strong correlation between a company’s possession of dynamic capabilities in terms of their factors, due to the new multi-dimensional model presented in this paper, with its possession of innovation capabilities. Based on the results, all five hypotheses were accepted. Ultimately, it was concluded that there is a strong association between the dynamic and innovation capabilities of a company. 

Keywords: dynamic capabilities, innovation capabilities, competitive advantage, business results

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Authors: Salah Kayed Kayed, Jessica Hong Yang

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This study investigates, whether earnings management in the audited financial statements is associated with tone management in the narrative sections of the annual report in the UK. Earnings management and narrative disclosure are communication strategies used from managers to communicate with investors or other users. Because earnings management and narrative disclosure stem from managers, they can exploit this by doing manipulation in their earnings, and simultaneously disclosing qualitative text (narrative information) in their reports as a tone of words, which will affect users’ perception, and hence users will be misinformed. The association between earnings and tone management can be explained by the self-serving, through cognitive reference points, theory. The sample period lasts from 2010 to 2015, and the sample comprises all non-financial firms that consider under FTSE 350 in any year during the sample period. A list of words from previous research is used to measure the tone in the narrative sections of the annual report. Because this study focuses on the managerial strategic choice and the subjective issues that come from management, it uses the abnormal tone to capture the managerial discretion on tone, and a number of different discretionary accruals proxies to measure earnings management, where accruals management is considered as a manipulation tool from managers to change the users' perception. This research is motivated to fulfil the literature gap by examining the association between earnings and tone management. Moreover, if firms that apply earnings management use tone management to mislead investors, it is beneficial for investors, policy makers, standard setters, or other users to know whether there is an association between earnings management and tone management. Clearly, we believe that this study is fundamental in the accounting context, where it evaluates the communication strategies that are used in firms' financial reports. Consistent with prior research, it is expected that tone management is positively associated with earnings management. This means that firms that use earnings management have incentives to manipulate in their narrative disclosure through tone of words, to reflect a good perception for users, which will conceal the earnings management techniques used in their reporting.

Keywords: earnings management, FTSE 350, narrative disclosure, tone management

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Authors: V. U. Onyemauwa

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Conflicts have always been part of human societies. So long as there is interaction amongst individuals or societies, there are bound to be conflicts as a result of the fact that interests among individuals and societies vary. The issue of conflict has become one of the regular headlines in the daily news of the Nigerian and global media today. Nigerian polity has suffered from one conflict or another, ranging from religious, civil, political, cultural, regional and ethnic violence. It has been found out that, the most disturbing part of these acts of conflicts in Nigeria and around the globe is that most of them have traced their roots to religion. Even some perpetrators of these acts of conflicts most of the time justify their actions with religion, thereby wrongly making religion an object of conflict and violence. In this regard, the study seeks to project religion as a potent tool for conflict resolution because it has a way of permeating through the hearts of men. It has a special responsibility of identifying conflicts and proffer solutions. It also has to provide theological reasoning as to why and how these conflicts come about and how they can possibly be solved. Religious actors are known to contribute to the processes of structural reform necessary for the restoration of productive social relations and political stability after a period of conflict and human rights abuses. The study examines the modalities for projecting religious conflict management strategies in Nigeria using an analysis of relevant documents as well as Black’s Social Control Theory and Thomas-Kilmann’s Model of Conflict Management as its theoretical frameworks. It recommends for a religiously-based means of conflict resolution in Nigeria. Religious individuals and faith-based organisations, as carriers of religious ideas are implore to play active roles in conflict resolution and peace-building in Nigeria by creating conducive environment for peaceful talks, mediation and reconciliation. This will enhance social cohesion, provides solid foundation for peace, progress and development in the society.

Keywords: conflict, peace, religion, resolution

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Authors: Chi-Hsuan Cheng

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This research aims to evaluate public-private partnerships against cyberattacks by comparing the UK and Taiwan. First, the study analyses major cyberattacks and factors influencing cybersecurity in both countries. Second, it assesses the effectiveness of current cyber defence strategies in combating cyberattacks by comparing the approaches taken in the UK and Taiwan, while also evaluating the cyber resilience of both nations. Lastly, the research evaluates existing public-private partnerships by comparing those in the UK and Taiwan, and proposes recommendations for enhancing cooperation and collaboration mechanisms in tackling cyberattacks. Grounded theory serves as the core research method. Theoretical sampling is used to recruit participants in both the UK and Taiwan, including investigators, police officers, and professionals from cybersecurity firms. Semi-structured interviews are conducted in English in the UK and Mandarin in Taiwan, recorded with consent, and pseudonymised for privacy. Data analysis involves open coding, grouping excerpts into codes, and categorising codes. Axial coding connects codes into categories, leading to the development of a codebook. The process continues iteratively until theoretical saturation is reached. Finally, selective coding identifies the core topic, evaluating public-private cooperation against cyberattacks and its implications for social and policing strategies in the UK and Taiwan, which highlights the current status of the cybersecurity industry, governmental plans for cybersecurity, and contributions to cybersecurity from both government sectors and cybersecurity firms, with a particular focus on public-private partnerships. In summary, this research aims to offer practical recommendations to law enforcement, private sectors, and academia for reflecting on current strategies and tailoring future approaches in cybersecurity

Keywords: cybersecurity, cybercrime, public private partnerships, cyberattack

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Authors: Avinash Nayak, Debopam Das

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The current work implements the variational principle to find the optimum initial perturbation that provides maximum growth in an impulsively blocked channel flow. The conventional method for studying temporal stability has always been through modal analysis. In most of the transient flows, this modal analysis is still followed with the quasi-steady assumption, i.e. change in base flow is much slower compared to perturbation growth rate. There are other studies where transient analysis on time dependent flows is done by formulating the growth of perturbation as an initial value problem. But the perturbation growth is sensitive to the initial condition. This study intends to find the initial perturbation that provides the maximum growth at a later time. Here, the expression of base flow for blocked channel is derived and the formulation is based on the two dimensional perturbation with stream function representing the perturbation quantity. Hence, the governing equation becomes the Orr-Sommerfeld equation. In the current context, the cost functional is defined as the ratio of disturbance energy at a terminal time 'T' to the initial energy, i.e. G(T) = ||q(T)||2/||q(0)||2 where q is the perturbation and ||.|| defines the norm chosen. The above cost functional needs to be maximized against the initial perturbation distribution. It is achieved with the constraint that perturbation follows the basic governing equation, i.e. Orr-Sommerfeld equation. The corresponding adjoint equation is derived and is solved along with the basic governing equation in an iterative manner to provide the initial spatial shape of the perturbation that provides the maximum growth G (T). The growth rate is plotted against time showing the development of perturbation which achieves an asymptotic shape. The effects of various parameters, e.g. Reynolds number, are studied in the process. Thus, the study emphasizes on the usage of optimal perturbation and its growth to understand the stability characteristics of time dependent flows. The assumption of quasi-steady analysis can be verified against these results for the transient flows like impulsive blocked channel flow.

Keywords: blocked channel flow, calculus of variation, hydrodynamic stability, optimal perturbation

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Authors: Nada Alghali

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Translanguaging pedagogy suggests a new perspective in language education relating to multilingualism; multilingual learners have one linguistic repertoire and not two or more separate language systems (García and Wei, 2014). When learners translanguage, they are able to draw on all their language features in a flexible and integrated way (Otheguy, García, & Reid, 2015). In the Foreign Language Classroom, however, the tendency to use the target language only is still advocated as a pedagogy. This study attempts to enable learners in the English as a foreign language classroom to draw on their full linguistic repertoire through collaborative reading lessons. In observations prior to this study, in a classroom where English only policy prevails, learners still used their first language in group discussions yet were constrained at times by the teacher’s language policies. Through strategically enabling translanguaging in reading lessons (Celic and Seltzer, 2011), this study has revealed that learners showed creative ways of language use for learning and reflected positively on thisexperience. This case study enabled two groups in two different proficiency level classrooms who are learning English as a foreign language in their first year at University in Saudi Arabia. Learners in the two groups wereobserved over six weeks and wereasked to reflect their learning every week. The same learners were also interviewed at the end of translanguaging weeks after completing a modified model of the learning reflection (Ash and Clayton, 2009). This study positions translanguaging as collaborative and agentive within a sociocultural framework of learning, positioning translanguaging as a resource for learning as well as a process of learning. Translanguaging learning episodes are elicited from classroom observations, artefacts, interviews, reflections, and focus groups, where they are analysed qualitatively following the sociocultural discourse analysis (Fairclough &Wodak, 1997; Mercer, 2004). Initial outcomes suggest functions of translanguaging in collaborative reading tasks and recommendations for a collaborative translanguaging pedagogy approach in the EFL classroom.

Keywords: translanguaging, EFL, sociocultural theory, discourse analysis

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Authors: Gaelle Candel, David Naccache

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t-SNE is an embedding method that the data science community has widely used. It helps two main tasks: to display results by coloring items according to the item class or feature value; and for forensic, giving a first overview of the dataset distribution. Two interesting characteristics of t-SNE are the structure preservation property and the answer to the crowding problem, where all neighbors in high dimensional space cannot be represented correctly in low dimensional space. t-SNE preserves the local neighborhood, and similar items are nicely spaced by adjusting to the local density. These two characteristics produce a meaningful representation, where the cluster area is proportional to its size in number, and relationships between clusters are materialized by closeness on the embedding. This algorithm is non-parametric. The transformation from a high to low dimensional space is described but not learned. Two initializations of the algorithm would lead to two different embeddings. In a forensic approach, analysts would like to compare two or more datasets using their embedding. A naive approach would be to embed all datasets together. However, this process is costly as the complexity of t-SNE is quadratic and would be infeasible for too many datasets. Another approach would be to learn a parametric model over an embedding built with a subset of data. While this approach is highly scalable, points could be mapped at the same exact position, making them indistinguishable. This type of model would be unable to adapt to new outliers nor concept drift. This paper presents a methodology to reuse an embedding to create a new one, where cluster positions are preserved. The optimization process minimizes two costs, one relative to the embedding shape and the second relative to the support embedding’ match. The embedding with the support process can be repeated more than once, with the newly obtained embedding. The successive embedding can be used to study the impact of one variable over the dataset distribution or monitor changes over time. This method has the same complexity as t-SNE per embedding, and memory requirements are only doubled. For a dataset of n elements sorted and split into k subsets, the total embedding complexity would be reduced from O(n²) to O(n²=k), and the memory requirement from n² to 2(n=k)², which enables computation on recent laptops. The method showed promising results on a real-world dataset, allowing to observe the birth, evolution, and death of clusters. The proposed approach facilitates identifying significant trends and changes, which empowers the monitoring high dimensional datasets’ dynamics.

Keywords: concept drift, data visualization, dimension reduction, embedding, monitoring, reusability, t-SNE, unsupervised learning

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Authors: P. Moskal, T. Bednarski, P. Bialas, E. Czerwinski, A. Gajos, A. Gruntowski, D. Kaminska, L. Kaplon, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemien, E. Kubicz, Sz. Niedzwiecki, M. Palka, L. Raczynski, Z. Rudy, P. Salabura, N. G. Sharma, M. Silarski, A. Slomski, J. Smyrski, A. Strzelecki, A. Wieczorek, W. Wislicki, M. Zielinski, N. Zon

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A new concept and results of the performance tests of the TOF-PET detection system developed at the Jagiellonian University will be presented. The novelty of the concept lies in employing long strips of polymer scintillators instead of crystals as detectors of annihilation quanta, and in using predominantly the timing of signals instead of their amplitudes for the reconstruction of Lines-of-Response. The diagnostic chamber consists of plastic scintillator strips readout by pairs of photo multipliers arranged axially around a cylindrical surface. To take advantage of the superior timing properties of plastic scintillators the signals are probed in the voltage domain with the accuracy of 20 ps by a newly developed electronics, and the data are collected by the novel trigger-less and reconfigurable data acquisition system. The hit-position and hit-time are reconstructed by the dedicated reconstruction methods based on the compressing sensing theory and the library of synchronized model signals. The solutions are subject to twelve patent applications. So far a time-of-flight resolution of ~120 ps (sigma) was achieved for a double-strip prototype with 30 cm field-of-view (FOV). It is by more than a factor of two better than TOF resolution achievable in current TOF-PET modalities and at the same time the FOV of 30 cm long prototype is significantly larger with respect to typical commercial PET devices. The Jagiellonian PET (J-PET) detector with plastic scintillators arranged axially possesses also another advantage. Its diagnostic chamber is free of any electronic devices and magnetic materials thus giving unique possibilities of combining J-PET with CT and J-PET with MRI for scanning the same part of a patient at the same time with both methods.

Keywords: PET-CT, PET-MRI, TOF-PET, scintillator

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Authors: Liliana Rytel, Jarosław Całka

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One of the diseases that are very common health problem of modern man is the stomach hyperacidity. It is well known that this pathological state, during which gastric glands secrete too much of hydrochloric acid can be caused due to various factors such as stress, eating habits, alcohol, smoking and some, especially anti-inflammatory drugs. Moreover, hyperacidity is recognized as one of factors leading to development of peptic ulcer disease. Therefore, we analyzed expression of substance P (SP) and neuronal isoform of nitric oxide synthase (nNOS) in the porcine nodose ganglion sensory neurons innervating prepyloric stomach region in physiological state and following intragastric infusion of hydrochloric acid. The study was performed on 8 immature gilts of the Large White Polish breed. All animals were injected retrograde marker Fast Blue (FB) into the anterior prepyloric stomach wall. After injections of FB, pigs were divided into two groups: control (group C; n = 4) and experimental (HCL group, n = 4) and after convalescence period of 23 days, animals of HCL group were subjected to renewed anaesthesia. Then, 0.25 M aqueous solution of hydrochloric acid with a dose of 5 ml/kg body weight was administered intragastrically with use of a stomach tube. On 28th day, all control and HCL pigs were euthanized and bilateral reght (rNG) and left (lNG) were collected. Cryostat sections were processed for double immunofluorescence using anibodies against SP and NOS. Immunofluorescence staining in the even-numbered ganglia nodes showed the presence of FB-positive cells expressing SP (45,9 ± 3,38% in rNG and 60,4 ± 1,71% in lNG), and nNOS (34,9 ± 6,83% in rNG and 49,9 ± 9,32% in lNG). In HCL group increased expression of both SP (54,8 ± 5,34% in rNG and 56,9 ± 3,28 % in lNG) as well as nNOS (54,9 ± 4,45% in rNG and 52,5 ± 2,17 % in lNG) in FB+ perikaria was found. The acquired results suggest that SP and nNOS are neurotransmitters and/ or neuromodulators participating in the sensory regulation of the prepyloric region of porcine stomach function as well as their potential role in development of the stomach inflamatory state.

Keywords: nNOS, nodose ganglion, pig, SP

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Authors: Lakdar Sadi-Haddad

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The past few years study of very high speed electrical drives have seen a resurgence of interest. An inventory of the number of scientific papers and patents dealing with the subject makes it relevant. In fact democratization of magnetic bearing technology is at the origin of recent developments in high speed applications. These machines have as main advantage a much higher power density than the state of the art. Nevertheless particular attention should be paid to the design of the inverter as well as control and command. Surface mounted permanent magnet synchronous machine is the most appropriate technology to address high speed issues. However, it has the drawback of using a carbon sleeve to contain magnets that could tear because of the centrifugal forces generated in rotor periphery. Carbon fiber is well known for its mechanical properties but it has poor heat conduction. It results in a very bad evacuation of eddy current losses induce in the magnets by time and space stator harmonics. The three-phase inverter is the main harmonic source causing eddy currents in the magnets. In high speed applications such harmonics are harmful because on the one hand the characteristic impedance is very low and on the other hand the ratio between the switching frequency and that of the fundamental is much lower than that of the state of the art. To minimize the impact of these harmonics a first lever is to use strategy of modulation producing low harmonic distortion while the second is to introduce a sinus filter between the inverter and the machine to smooth voltage and current waveforms applied to the machine. Nevertheless, in very high speed machine the interaction of the processes mentioned above may introduce particular harmonics that can irreversibly damage the system: harmonics at the resonant frequency, harmonics at the shaft mode frequency, subharmonics etc. Some studies address these issues but treat these phenomena with separate solutions (specific strategy of modulation, active damping methods ...). The purpose of this paper is to present a complete new active harmonic compensation algorithm based on an improvement of the standard vector control as a global solution to all these issues. This presentation will be based on a complete theoretical analysis of the processes leading to the generation of such undesired harmonics. Then a state of the art of available solutions will be provided before developing the content of a new active harmonic compensation algorithm. The study will be completed by a validation study using simulations and practical case on a high speed machine.

Keywords: active harmonic compensation, eddy current losses, high speed machine

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Authors: Girish Chandran, Milu Tigi

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Brian O'Doherty's seminal essay, Inside the white Cube theorized and named the dominant mode of display and exhibition of Modern Art museums. Ever since the advent of Biennales and other site-specific public art projects we have seen a departure from the white cube mode of exhibition. The physicality, materiality and context within which an artwork is framed has a role in the production of meaning of public art. Equally, artworks contribute to the meaning and identity of a place. This to and fro relationship between the site and artwork and its influence on the sense of place and production of meaning is being explored in this paper in the context of Kochi Muziris Biennale (KMB). Known as the Peoples biennale with over 5 lakh visitors, it is India's first Biennale and its largest art exhibition of contemporary art. The paper employs place theory and contemporary curatorial theories to present the case. The KMB has an interesting mix of exhibition spaces which includes existing galleries and halls, site-specific projects in public spaces, infill developments and adaptive reuse of heritage and other unused architecture. The biennale was envisioned as an event connecting to the history, socio-political peculiarities of the cultural landscape of Kerala and more specifically Kochi. The paper explains the role of spatial elements in forming a curatorial narrative connected to the above mentioned ambitions.The site-specific nature of exhibition and its use of unused architecture helps in the formation of exhibition spaces unique in type and materiality. The paper argues how this helps in the creation of an 'archeology of the place'. The research elucidates how a composite nature of experience helps connect with the thematic ambitions of the Biennale and how it brings about an aesthetics distinct to KMB.

Keywords: public art, curatorial practice, architecture, place, contemporary art, site specificity

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Authors: Marianna Maiaru, Gregory M. Odegard

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During the processing of high-performance thermoset polymer matrix composites, chemical reactions occur during elevated pressure and temperature cycles, causing the constituent monomers to crosslink and form a molecular network that gradually can sustain stress. As the crosslinking process progresses, the material naturally experiences a gradual shrinkage due to the increase in covalent bonds in the network. Once the cured composite completes the cure cycle and is brought to room temperature, the thermal expansion mismatch of the fibers and matrix cause additional residual stresses to form. These compounded residual stresses can compromise the reliability of the composite material and affect the composite strength. Composite process modeling is greatly complicated by the multiscale nature of the composite architecture. At the molecular level, the degree of cure controls the local shrinkage and thermal-mechanical properties of the thermoset. At the microscopic level, the local fiber architecture and packing affect the magnitudes and locations of residual stress concentrations. At the macroscopic level, the layup sequence controls the nature of crack initiation and propagation due to residual stresses. The goal of this research is use molecular dynamics (MD) and finite element analysis (FEA) to predict the residual stresses in composite laminates and the corresponding effect on composite failure. MD is used to predict the polymer shrinkage and thermomechanical properties as a function of degree of cure. This information is used as input into FEA to predict the residual stresses on the microscopic level resulting from the complete cure process. Virtual testing is subsequently conducted to predict strength allowables. Experimental characterization is used to validate the modeling.

Keywords: molecular dynamics, finite element analysis, processing modeling, multiscale modeling

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Authors: B.J. Khoza, B. Kembo

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Global socioeconomic developments and ever-growing technological advancements of the art and design industry indicate the pivotal importance of lifelong learning. There exists a discrepancy between competencies, personal ambition, and workplace requirements. There are few , if at all, institutions of higher learning in South Africa which offer Short Learning Programmes (SLP) in Art and Design Education. Traditionally, Art and Design education is delivered face to face via a hands-on approach. In this way the enduring perception among educators is that art and design education does not lend itself to online delivery. Short Learning programmes (SLP) are a concentrated approach to make revenue and lure potential prospective students to embark on further education study, this is often of weighted value to both students and employers. SLPs are used by Higher Education institutions to generate income in support of the core academic programmes. However, there is a gap in terms of the translation of art and design studio pedagogy into SLPs which provide quality education, are adaptable and delivered via a blended mode. In our paper, we propose a conceptual framework drawing on secondary research to analyse existing research to SLPs for arts and design education. We aim to indicate a new dimension to the process of using a design-based research approach for short learning programmes in art and design education. The study draws on a conceptual framework, a qualitative analysis through the lenses of Herrington, McKenney, Reeves and Oliver (2005) principles of the design-based research approach. The results of this study indicate that design-based research is not only an effective methodological approach for developing and deploying arts and design education curriculum for 1st years in Higher Education context but it also has the potential to guide future research. The findings of this study propose that the design-based research approach could bring theory and praxis together regarding a common purpose to design context-based solutions to educational problems.

Keywords: design education, design-based research, digital literacies, multi-literacies, short learning programme

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Authors: Reem Alsager, James Milton

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Coxhead’s (2000) Academic Word List (AWL) believed to be essential for students pursuing higher education and helps differentiate English for Academic Purposes (EAP) from General English as a course of study, and it is thought to be important for comprehending English academic texts. It has been described that AWL is an infrequent, discrete set of vocabulary items unreachable from general language. On the other hand, it has been known for a period of time that general vocabulary knowledge is a good predictor of academic achievement. This study, however, is an attempt to measure and compare the contribution of academic knowledge and general vocabulary knowledge to learners’ GPA and examine what knowledge is a better predictor of academic achievement and investigate whether AWL as a specialised list of infrequent words relates to the frequency effect. The participants were comprised of 44 international postgraduate students in Swansea University, all from the School of Management, following the taught MSc (Master of Science). The study employed the Academic Vocabulary Size Test (AVST) and the XK_Lex vocabulary size test. The findings indicate that AWL is a list based on word frequency rather than a discrete and unique word list and that the AWL performs the same function as general vocabulary, with tests of each found to measure largely the same quality of knowledge. The findings also suggest that the contribution that AWL knowledge provides for academic success is not sufficient and that general vocabulary knowledge is better in predicting academic achievement. Furthermore, the contribution that academic knowledge added above the contribution of general vocabulary knowledge when combined is really small and noteworthy. This study’s results are in line with the argument and suggest that it is the development of general vocabulary size is an essential quality for academic success and acquiring the words of the AWL will form part of this process. The AWL by itself does not provide sufficient coverage, and is probably not specialised enough, for knowledge of this list to influence this general process. It can be concluded that AWL as an academic word list epitomizes only a fraction of words that are actually needed for academic success in English and that knowledge of academic vocabulary combined with general vocabulary knowledge above the most frequent 3000 words is what matters most to ultimate academic success.

Keywords: academic achievement, academic vocabulary, general vocabulary, vocabulary size

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Authors: Caiwei Zhu, Remke Klapwijk

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Spatial thinking, a way of thinking based on the understanding and reasoning of spatial concepts and representations, is embedded in science, technology, engineering, arts, and mathematics (STEAM) learning. Aside from many studies that successfully used targeted training to improve students’ spatial thinking skills, few have closely examined how spatial thinking can be trained in classroom settings. Design and technology education, which receives increasing attention towards its integration into formal curriculums, inherently encompasses a wide range of spatial activities, such as constructing mental representations of design ideas, mentally transforming objects and materials to form designs, visually communicating design plans through annotated drawings, and creating 2D and 3D design artifacts. Among different design topics, biomimicry offers a unique avenue for students to recognize and analyze the shapes and structures in nature. By mapping the forms of plants and animals onto functions, students gain inspiration to solve human design challenges. This study is one of the first to highlight opportunities for training spatial thinking in a biomimicry design project for primary school students. Embracing methodological principles of educational design-based research, this case study is conducted along with iterations in the design of the intervention and collaboration with teachers. Data are harvested from small groups of 10- to 12-year-olds at an international school in the Netherlands. Classroom videos, semi-structured interviews with students, design drawings and artifacts, formative assessment, and the pre- and post-intervention spatial test triangulate evidence for students' spatial thinking. In addition to contributing to a theory of integrating spatial thinking in the primary curriculum, mechanisms underlying such improvement in spatial thinking are explored and discussed.

Keywords: biomimicry, design and technology education, primary education, spatial thinking

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Authors: Igor Vishnevskyi

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Introduction: The urinary bladder undergoes repeated strain during its working cycle, suggesting the presence of an efficient support system, force transmission, and mechanical amplification. The concept of a "hydrostatic skeleton" (HS) could contribute to our understanding of the functional relationships among bladder constituents. Methods: A multidisciplinary literature review was conducted to identify key features of the HS and to gather evidence supporting its applicability in urinary bladder biomechanics. The collected evidence was synthesized to propose a framework for understanding the potential hydrostatic properties of the urinary bladder based on existing knowledge and HS principles. Results: Our analysis revealed similarities in biomechanical features between living fluid-filled structures and the urinary bladder. These similarities include the geodesic arrangement of fibres, the role of enclosed fluid (urine) in force transmission, prestress as a determinant of stiffness, and the ability to maintain shape integrity during various activities. From a biomechanical perspective, urine may be considered an essential component of the bladder. The hydrostatic skeleton, with its autonomy and flexibility, may provide insights for researchers involved in bladder engineering. Discussion: The concept of a hydrostatic skeleton offers a holistic perspective for understanding bladder function by considering multiple mechanical factors as a single structure with emergent properties. Incorporating viewpoints from various fields on HS can help identify how this concept applies to live fluid-filled structures or organs and reveal its broader relevance to biological systems, both natural and artificial. Conclusion: The hydrostatic skeleton (HS) design principle can be applied to the urinary bladder. Understanding the bladder as a structure with HS can be instrumental in biomechanical modelling and engineering. Further research is required to fully elucidate the cellular and molecular mechanisms underlying HS in the bladder.

Keywords: hydrostatic skeleton, urinary bladder morphology, shape integrity, prestress, biomechanical modelling

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Authors: Karl Gerrard Tiu See

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Military bases are an indelible mark of prolonged US defense relationships in the Pacific. Bases like the Subic Naval Base in Olongapo City have irreversible consequences for their host communities, not all of which are positive. One consequence the Subic Naval Base had for Olongapo City was the rise of vibrant sex industry. While the Philippine Senate voted to remove US bases like Subic in 1991, the question remains as to why did prostitution not end after the bases pull-out? To answer this question, the study used an institutionalist lens coupled with focus group discussions from the sex industry. It found that prostitution persisted due to two main reasons. The first was that like Olongapo City; the sex industry successfully shifted its reliance from the military to foreign tourism. The second was that agreements such as the 1996 Visiting Forces Agreement (VFA) ensured that the sex industry continued to receive US military clientele. With the contextual factors as the backdrop, this study used the Theory of Institutional Change to study institutions pivotal in altering Olongapo City and its sex industry after Subic Naval Base. These include local government, civil society actors such as NGOs, and the city’s economic base. The study found that policy such as the VFA allowed the bases period status quo to revive (Symbionts). This led to renewed exploitation from the military presence coupled with foreign tourism (Opportunists). The local government, however, shifted focus away from base reliance which allowed a reinvigorated civil society to effect a gradual change (Subversives). Furthermore, uncertainties like rising HIV incidence, abandoned children born from US soldiers, and the Enhanced Defence Cooperation Agreement (EDCA) remain to change the sex industry’s future, for better or worse.

Keywords: Philippine-USA defence relations, overseas USA basing, 1991 Philippine-USA bases pull-out, Olongapo city, Subic naval base, institutional change

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Authors: Jakia Rajoana

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The key aim of this research is to achieve Sustainable Rural Tourism (SRT) through women’s empowerment in the Sundarbans area of Bangladesh. Women in rural areas in developing countries depend on biomass for their survival and that of their family. Yet they have an unequal access to resources as well as decision making, thus making them more vulnerable to any changes in the environment. Women in the developing countries experience gender inequality which is culturally embedded resulting into women having less access to and control over financial and material resources, information, and also a lack of recognition of their contribution as compared to men. Their disadvantaged social position is augmented by their extreme poverty, little or no power they have over their own lives vis-à-vis the disproportionate burden they bear in reproduction and child-raising. Despite the significance of the need to pay attention to gender related issues in sustainable rural tourism (SRT), research remains rather scant. For instance, there is very little research that illustrates the role of women in tourism in the Sundarbans area. Thus empirically, this research seeks to fill a significant gap by focusing on rural areas and in particular focus on considerably under-researched area, namely the Sundarbans women’s role in tourism. In order to fully comprehend their experiences and life stories, this research will apply the empowerment theory and consider it along with the research on sustainable rural tourism. Since, women’s empowerment can act as a potential tool for SRT development and also examine the role tourism plays in the lives of Sundarbans’ women. Methodologically, this study will follow a qualitative research design using an ethnographic approach. Participant observation, semi- structured interviews, and documentation will be the primary data collection instruments in four communities – Shayamnagar, Koyra, Mongla and Sarankhola – in the Sundarbans area. It is hoped that by focusing on the life stories of these invisible women, research is better able to engage with nuances inherent in marginal and significantly under-researched communities.

Keywords: gender, sustainable rural tourism, women empowerment, Sundarbans

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Authors: Bernice Badal

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This article addresses a persistent challenge related to teacher agency in knowledge acquisition in professional development (PD) workshops in contexts of educational change, given that scholarship identifies a need for more teacher involvement and amplification of teacher's voices. Theoretical concepts are drawn from Bandura’s Social cognitive theory, incorporating the triadic causation model of agency to examine the reciprocal nature of the context, teacher characteristics, and systemic influences that shape how knowledge is transmitted and acquired in PD workshops. This qualitative study, using a mix of classroom observations and interviews, explored the political, contextual, and personal characteristics of teacher agency in PD through an analysis of data extracted from a PhD study. The narratives of six teachers from three township schools are examined to show how PD efforts in South Africa have failed to take account of the holistic development of teacher agency in knowledge dissemination and how this shapes teacher self-efficacy beliefs about being able to masterfully apply the tenets of the reform. Agency, teacher voice, and contextual considerations were used as markers of the quality of the training provided to understand how knowledge is acquired and meaning is made. The findings suggest that systemic influences of institutionally imposed PD offer partial understandings of the reform, which is offered in traditional formats that do not consider teacher empowerment in knowledge production and the development of teacher agency. Common in all the participants’ responses is the need for more information and training on the prescribed approach for teaching English as a second language; however, this paper holds the view that more information may not solve teachers’ dilemmas. Accordingly, it recommends a restructuring of the programme with facilitators being more cognisant of teacher agency for the development of transformative teachers. The findings of the study contribute to the field of teacher knowledge, teacher training, and professional development in the context of educational reforms.

Keywords: teacher professional development, teacher voice, teacher agency, educational reforms, teacher knowledge

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Authors: Tom Hickey

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It is difficult to conceive of a case that might more starkly bring the arguments concerning judicial review to the fore than State (Ryan) v Lennon. Small wonder that it has attracted so much scholarly attention, although the fact that almost all of it has been in an Irish setting is perhaps surprising, given the illustrative value of the case in respect of a philosophical quandary that continues to command attention in all developed constitutional democracies. Should judges have power to invalidate legislation? This article revisits Ryan v Lennon with an eye on the importance of the idea of “democracy” in the case. It assesses the meaning of democracy: what its purpose might be and what practical implications might follow, specifically in respect of judicial review. Based on this assessment, it argues for a particular institutional model for the vindication of constitutional rights. In the context of calls for the drafting of a new constitution for Ireland, however forlorn these calls might be for the moment, it makes a broad and general case for the abandonment of judicial supremacy and for the taking up of a model in which judges have a constrained rights reviewing role that informs a more robust role that legislators would play, thereby enhancing the quality of the control that citizens have over their own laws. The article is in three parts. Part I assesses the exercise of judicial power over legislation in Ireland, with the primary emphasis on Ryan v Lennon. It considers the role played by the idea of democracy in that case and relates it to certain apparently intractable dilemmas that emerged in later Irish constitutional jurisprudence. Part II considers the concept of democracy more generally, with an eye on overall implications for judicial power. It argues for an account of democracy based on the idea of equally shared popular control over government. Part III assesses how this understanding might inform a new constitutional arrangement in the Irish setting for the vindication of fundamental rights.

Keywords: constitutional rights, democracy as popular control, Ireland, judicial power, republican theory, Ryan v Lennon

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Authors: Nahed M. M. Ismail, Bayoumy B. Mostafa, Ahmed Abdel-Kader, Khalil M. El-Said, Asmaa Abdel-Motleb, Hoda M. Abu Taleb

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This study was carried out in lined and unlined watercourses in Beheira and Giza governorates to investigate the effect of water canals lining on water quality and aquatic vegetations. Samples of water and aquatic plants were collected from the examining sites during four seasons in two successive years. The main ecological parameters were recorded and water quality was measured. Results showed that the mean value of water conductivity and total dissolved salts in lined sites was significantly lower than those of unlined ones (p < 0.01, p < 0.05). In Beheira, the dissolved oxygen concentrations during autumn and winter were higher in lined sites (3.93±1.3 and 9.6±1.1 ppm, respectively) than those of unlined ones (the same values of 1.2±0.6 ppm). However, it represented by lower values of 5.77±6.05 and 4.9±1.8 ppm in lined watercourses in spring and summer, respectively, comparing with those in unlined ones (14.05±5.59 and 5.83±0.8 ppm, respectively). Generally, Zn, Pb, Fe, Cd were higher in both lined and unlined sites during summer than the other seasons. However, Zn and Fe were higher in lined sites (0.78±0.37 and 17.4±4.3 ppb, respectively) during summer than that of unlined ones (0.4±0.1 and 10.95±1.93 ppb, respectively). Cu was absent during summer in lined and unlined sites and only in unlined ones during spring. Regarding to Giza sites, Cu and Pb were absent in both lined and unlined sites during summer and only in unlined ones during spring. Whereas, Fe recorded higher values in autumn in both lined (8.8±20.1 ppb) and unlined sites (15.16±3 ppb) than the other seasons. Present survey study revealed that 13 species of aquatic plants were collected from lined and unlined sites in Beheira and Giza governorates. Eichhornia crassipes, Ceratophyllum demersum, and Potamogeton sp. were the only plant species infested the examined sites during autumn and winter in Beheira. In autumn C. demersum was the only plant found in lined sites represented by highly lower significant percentage (12.5% of the all examined sites) compared to the unlined sites (50%). E. crassipes was completely absent in the lined sites during the two seasons. In spring, there is only 3 plant species in lined sites compared to 6 ones in unlined. Also, in summer, there is only 2 species in lined sites comparing with 5 in unlined. The percentage of occurrence and density of these plants was highly significant (p < 0.01, p < 0.001) higher in unlined sites compared to the lined ones during all seasons. A diversity of plant species, E. crassipes, C. demersum, Jussias repens, Lemma giba, and Polygonum serr were the most abundant in many examined sites during all seasons in Giza. In summer, the percentage of sites containing the two plants E. crassipes (83.3%) and C. demersum (50%) was highly significant (p < 0.001) higher in unlined sites compared to the lined ones (50% and 0.0%, respectively). It concluded from the results that watercourses lining may play a significant role in preserving water with a good quality and reduces the distribution of aquatic vegetation which rendered the current of water.

Keywords: aquatic plants, lining of watercourses, physicochemical parameters, water quality

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Authors: Michael K. O. Ayomoh, Oyindamola A. Omotuyi

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Autonomous mobile robots deployed to explore or operate in a never explored or an abandoned sub-surface mine requires extreme effectiveness in coordination and communication. In a bid to transmit information from the depth of the mine to the external surface in real-time and amidst diverse physical, chemical and virtual impediments, the concept of unified cooperative robots is seen to be a proficient approach. This paper presents an effective [human → robot → task] coordination framework for effective exploration of an abandoned underground mine. The problem addressed in this research is basically the development of a globalized optimization model premised on time series differentiation and geometrical configurations for effective positioning of the two classes of robots in the cooperation namely the outermost stationary master (OSM) robots and the innermost dynamic task (IDT) robots for effective bi-directional signal transmission. In addition, the synchronization of a vision system and wireless communication system for both categories of robots, fiber optics system for the OSM robots in cases of highly sloppy or vertical mine channels and an autonomous battery recharging capability for the IDT robots further enhanced the proposed concept. The OSM robots are the master robots which are positioned at strategic locations starting from the mine open surface down to its base using a fiber-optic cable or a wireless communication medium all subject to the identified mine geometrical configuration. The OSM robots are usually stationary and function by coordinating the transmission of signals from the IDT robots at the base of the mine to the surface and in a reverse order based on human decisions at the surface control station. The proposed scheme also presents an optimized number of robots required to form the cooperation in a bid to reduce overall operational cost and system complexity.

Keywords: sub-surface mine, wireless communication, outermost stationary master robots, inner-most dynamic robots, fiber optic

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Authors: Begum Rokeya, Rahelee Zinnat, Fatema Jebunnesa, Israt Ara Hossain, A. Rahman

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Background and Aims: Arsenic in drinking water is a global environmental health problem, and the exposure may increase dyslipidemia and cerebrovascular diseases mortalities, most likely through causing atherosclerosis. However, the mechanism of lipid metabolism, atherosclerosis formation, arsenic exposure and impact in pregnancy is still unclear. Recent epidemiological evidences indicate close association between inorganic arsenic exposure via drinking water and Dyslipidemia. However, the exact mechanism of this arsenic-mediated increase in atherosclerosis risk factors remains enigmatic. We explore the association of the effect of arsenic on serum lipid profile in pregnant subjects. Methods: A total 200 pregnant mother screened in this study from arsenic exposed area. Our study group included 100 exposed subjects were cases and 100 Non exposed healthy pregnant were controls requited by a cross-sectional study. Clinical and anthropometric measurements were done by standard techniques. Lipidemic status was assessed by enzymatic endpoint method. Urinary As was measured by inductively coupled plasma-mass spectrometry and adjusted with specific gravity and Arsenic exposure was assessed by the level of urinary arsenic level > 100 μg/L was categorized as arsenic exposed and < 100 μg/L were categorized as non-exposed. Multivariate logistic regression and Student’s t - test was used for statistical analysis. Results: Systolic and diastolic blood pressure both were significantly higher in the Arsenic exposed pregnant subjects compared to the Non-exposed group (p<0.001). Arsenic exposed subjects had 2 times higher chance of developing hypertensive pregnancy (Odds Ratio 2.2). In parallel to the findings in Ar exposed subjects showed significantly higher proportion of triglyceride and total cholesterol and low density of lipo protein when compare to non- arsenic exposed pregnant subjects. Significant correlation of urinary arsenic level was also found with SBP, DBP, TG, T chol and serum LDL-Cholesterol. On multivariate logistic regression showed urinary arsenic had a positive association with DBP, SBP, Triglyceride and LDL-c. Conclusion: In conclusion, arsenic exposure may induce dyslipidemia like atherosclerosis through modifying reverse cholesterol transport in cholesterol metabolism. For decreasing atherosclerosis related mortality associated with arsenic, preventing exposure from environmental sources in early life is an important element.

Keywords: Arsenic Exposure, Dyslipidemia, Gestational Diabetes Mellitus, Serum lipid profile

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Authors: Rui Li, Min Wen, Kim Bang Salling

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For the modern railways, maintenance is critical for ensuring safety, train punctuality and overall capacity utilization. The cost of railway maintenance in Europe is high, on average between 30,000 – 100,000 Euros per kilometer per year. In order to reduce such maintenance expenditures, this paper presents a mixed 0-1 linear mathematical model designed to optimize the predictive railway tamping activities for ballast track in the planning horizon of three to four years. The objective function is to minimize the tamping machine actual costs. The approach of the research is using the simple dynamic model for modelling condition-based tamping process and the solution method for finding optimal condition-based tamping schedule. Seven technical and practical aspects are taken into account to schedule tamping: (1) track degradation of the standard deviation of the longitudinal level over time; (2) track geometrical alignment; (3) track quality thresholds based on the train speed limits; (4) the dependency of the track quality recovery on the track quality after tamping operation; (5) Tamping machine operation practices (6) tamping budgets and (7) differentiating the open track from the station sections. A Danish railway track between Odense and Fredericia with 42.6 km of length is applied for a time period of three and four years in the proposed maintenance model. The generated tamping schedule is reasonable and robust. Based on the result from the Danish railway corridor, the total costs can be reduced significantly (50%) than the previous model which is based on optimizing the number of tamping. The different maintenance strategies have been discussed in the paper. The analysis from the results obtained from the model also shows a longer period of predictive tamping planning has more optimal scheduling of maintenance actions than continuous short term preventive maintenance, namely yearly condition-based planning.

Keywords: integer programming, railway tamping, predictive maintenance model, preventive condition-based maintenance

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