Search results for: switching flux permanent magnet (SFPM) motor

Authors: Emmanuel Kamal Aziz Saba, Hussein Al-Moghazy Sultan

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The aim of this study was to evaluate clinically and electro physiologically the autonomic nervous system changes associated with rheumatoid arthritis (RA). The present study included 25 patients with RA [22 women (88%)] and 30 apparently healthy control subjects [27 women (90%)]. A thorough clinical examination was carried out. Disease activity and functional disability were assessed. Tests for assessment of autonomic functions include active and passive orthostatic stress tests, and sympathetic skin response (SSR). The presence of abnormality in 2 tests or more was a clue for the presence of autonomic neuropathy (AN). Sural sensory nerve conduction study and posterior tibial motor nerve conduction study were done. There was a statistically significant decrease in standing systolic and diastolic blood pressure (BP) components of the active orthostatic stress test and SSR amplitude as well as statistically significant prolongation of SSR latency of RA patients when compared to control. Three patients (12%) had clinical symptoms suggestive of AN; increased to 14 patients (56 %) when orthostatic stress tests and SSR were utilized. There were no statistically significant differences between patients with different disease activity score 28 with 4 variables grades of RA activity and SSR latency and amplitude. There were no statistically significant differences between patients with different Stanford Health Assessment Questionnaire Disability Index grades of RA functional disability and SSR latency and amplitude. In conclusion, autonomic neuropathy is a common extra-articular manifestation of RA affecting sympathetic and parasympathetic fibers.

Keywords: autonomic neuropathy, orthostatic stress test, rheumatoid arthritis, sympathetic skin response

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Authors: Sarayu Vanga, Jorge Galeano-Cabral, Kaya Wei

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Cerebral hypoxia refers to a condition in which there is a decrease in oxygen supply to the brain. Patients suffering from this condition experience a decrease in their body temperature. While there isn't any cure to treat cerebral hypoxia as of date, certain procedures are utilized to help aid in the treatment of the condition. Regulating the body temperature is an example of one of those procedures. Hypoxia is well known to reduce the body temperature of mammals, although the neural origins of this response remain uncertain. In order to speed recovery from this condition, it is necessary to maintain a stable body temperature. In this study, we present an approach to regulating body temperature for patients who suffer from cerebral hypoxia or other similar conditions. After a thorough literature study, we propose the use of thermoelectric blankets, which are temperature-controlled thermal blankets based on thermoelectric devices. These blankets are capable of heating up and cooling down the patient to stabilize body temperature. This feature is possible through the reversible effect that thermoelectric devices offer while behaving as a thermal sensor, and it is an effective way to stabilize temperature. Thermoelectricity is the direct conversion of thermal to electrical energy and vice versa. This effect is now known as the Seebeck effect, and it is characterized by the Seebeck coefficient. In such a configuration, the device has cooling and heating sides with temperatures that can be interchanged by simply switching the direction of the current input in the system. This design integrates various aspects, including a humidifier, ventilation machine, IV-administered medication, air conditioning, circulation device, and a body temperature regulation system. The proposed design includes thermocouples that will trigger the blanket to increase or decrease a set temperature through a medical temperature sensor. Additionally, the proposed design allows an efficient way to control fluctuations in body temperature while being cost-friendly, with an expected cost of 150 dollars. We are currently working on developing a prototype of the design to collect thermal and electrical data under different conditions and also intend to perform an optimization analysis to improve the design even further. While this proposal was developed for treating cerebral hypoxia, it can also aid in the treatment of other related conditions, as fluctuations in body temperature appear to be a common symptom that patients have for many illnesses.

Keywords: body temperature regulation, cerebral hypoxia, thermoelectric, blanket design

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Authors: Wenquan Gan, Peiyu Zhao, Xinyu Zhao

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Under the background of the rapid development of China’s ageing population, ageing-in-place has become a primary strategy to cope with this problem promoted by the Chinese government. However, most older adults currently living in old residential communities are insufficient to support their ageing-in-place. Therefore, exploring how to retrofit existing communities towards ageing-friendly standards to support older adults is essential for healthy ageing. To better cope with this issue, this study aims to shed light on the inter-relationship among the built environment, daily activities, and well-being of older adults in urban China. Using mixed research methods including GPS tracking, structured observation, and in-depth interview to examine: (a) what specific places or facilities are most commonly used by the elderly in the ageing-in-place process; (b) what specific built environment characteristics attract older adults in these frequently used places; (c) how has the use of these spaces impacted the well-being of older adults. Specifically, structured observation and GPS are used to record and map the older residents’ behaviour and movement in Suzhou, China, a city with a highly aged population and suitable as a research case. Subsequently, a follow-up interview is conducted to explore what impact of activities and the built environment on their well-being. Results showed that for the elderly with good functional ability, the facilities promoted by the Chinese government to support ageing-in-place, such as community nursing homes for the aged, day-care centre, and activity centres for the aged, are rarely used by older adults. Additionally, older adults have their preferred activities and built environment characteristics that contribute to their well-being. Our findings indicate that a complex interrelationship between the built environment and activities can influence the well-being of the elderly. Further investigations are needed to understand how to support healthy ageing-in-place, especially in addition to providing permanent elder-ly-care facilities, but to attend to the design interventions that can enhance these particularly built environment characteristics to facilitate a healthy lifestyle in later life.

Keywords: older adults, built environment, spatial behavior, community activity, healthy ageing

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Authors: Qingjin Liu, Jinpeng Niu, Kangjia Chen, Jiao Li, Huafu Chen, Wei Liao

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Functional connectomics is essential in cognitive science and neuropsychiatry, offering insights into the brain's complex network structures and dynamic interactions. Although neuroimaging has uncovered functional connectivity issues in Major Depressive Disorder (MDD) patients, the dynamic shifts in connectome topology and their link to gene expression are yet to be fully understood. To explore the differences in dynamic connectome topology between MDD patients and healthy individuals, we conducted an extensive analysis of resting-state functional magnetic resonance imaging (fMRI) data from 434 participants (226 MDD patients and 208 controls). We used multilayer network models to evaluate brain module dynamics and examined the association between whole-brain gene expression and dynamic module variability in MDD using publicly available transcriptomic data. Our findings revealed that compared to healthy individuals, MDD patients showed lower global mean values and higher standard deviations, indicating unstable patterns and increased regional differentiation. Notably, MDD patients exhibited more frequent module switching, primarily within the executive control network (ECN), particularly in the left dorsolateral prefrontal cortex and right fronto-insular regions, whereas the default mode network (DMN), including the superior frontal gyrus, temporal lobe, and right medial prefrontal cortex, displayed lower variability. These brain dynamics predicted the severity of depressive symptoms. Analyzing human brain gene expression data, we found that the spatial distribution of MDD-related gene expression correlated with dynamic module differences. Cell type-specific gene analyses identified oligodendrocytes (OPCs) as major contributors to the transcriptional relationships underlying module variability in MDD. In conclusion, this study offers the first comprehensive description of altered brain module dynamics in MDD patients linked to depressive symptom severity and changes in whole-brain gene expression profiles.

Keywords: major depressive disorder, module dynamics, magnetic resonance imaging, transcriptomic

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Authors: Sedef Şahin, Meral Huri

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Cerebral Palsy (CP) represents the most frequent cause of physical disability in children with a rate of 2,9 per 1000 live births. The activity-focused intervention is known to improve function and reduce activity limitations and barriers to participation of children with disabilities. The aim of the study was to assess the effects of occupational therapy on level of fatigue, activity performance and satisfaction in children with Unilateral Cerebral Palsy. Twenty-two children with hemiparetic cerebral palsy (mean age: 9,3 ± 2.1years; Gross Motor Function Classification System ( GMFCS) level from I to V (I = 54%, II = 23%, III = 14%, IV= 9%, V= 0%), Manual Ability Classification System (MACS) level from I to V (I = 40%, II = 32%, III = 14%, IV= 10%, V= 4%), were assigned to occupational therapy program for 6 weeks.Visual Analogue Scale (VAS) was used for intensity of the fatigue they experienced at the time on a 10 point Likert scale (1-10).Activity performance and satisfaction were measured with Canadian Occupational Performance Measure (COPM).A client-centered occupational therapy intervention was designed according to results of COPM. The results were compared with nonparametric Wilcoxon test before and after the intervention. Thirteen of the children were right-handed, whereas nine of the children were left handed.Six weeks of intervention showed statistically significant differences in level of fatigue, compared to first assessment(p<0,05). The mean score of first and the second activity performance scores were 4.51 ± 1.70 and 7.35 ± 2.51 respectively. Statistically significant difference between performance scores were found (p<0.01). The mean scores of first and second activity satisfaction scores were of 2.30± 1.05 and 5.51 ± 2.26 respectively. Statistically significant difference between satisfaction assessments were found (p<0.01). Occupational therapy is an evidence-based approach and occupational therapy interventions implemented by therapists were clinically effective on severity of fatigue, activity performance and satisfaction if implemented individually during 6 weeks.

Keywords: activity performance, cerebral palsy, fatigue, occupational therapy

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Authors: M. A. Talha, M. Osman Gani, M. Ferdows

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This paper focuses on the study of two dimensional magnetohydrodynamic (MHD) steady incompressible viscous Williamson nanofluid with exponential internal heat generation containing gyrotactic microorganism over a stretching sheet. The governing equations and auxiliary conditions are reduced to a set of non-linear coupled differential equations with the appropriate boundary conditions using similarity transformation. The transformed equations are solved numerically through spectral relaxation method. The influences of various parameters such as Williamson parameter γ, power constant λ, Prandtl number P_r, magnetic field parameter M, Peclet number P_e, Lewis number Le, Bioconvection Lewis number Lb, Brownian motion parameter Nb, thermophoresis parameter Nt, and bioconvection constant σ are studied to obtain the momentum, heat, mass and microorganism distributions. Moment, heat, mass and gyrotactic microorganism profiles are explored through graphs and tables. We computed the heat transfer rate, mass flux rate and the density number of the motile microorganism near the surface. Our numerical results are in better agreement in comparison with existing calculations. The Residual error of our obtained solutions is determined in order to see the convergence rate against iteration. Faster convergence is achieved when internal heat generation is absent. The effect of magnetic parameter M decreases the momentum boundary layer thickness but increases the thermal boundary layer thickness. It is apparent that bioconvection Lewis number and bioconvection parameter has a pronounced effect on microorganism boundary. Increasing brownian motion parameter and Lewis number decreases the thermal boundary layer. Furthermore, magnetic field parameter and thermophoresis parameter has an induced effect on concentration profiles.

Keywords: convection flow, similarity, numerical analysis, spectral method, Williamson nanofluid, internal heat generation

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Authors: Shih-Tsung Chen, Yenchin Hsiao

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Evergreen Lily is a newly-built school after Morakot Typhoon took place. The school is located on Majia farm, which is surrounded by mountains. The fund in the construction of the school is solely sponsored by Chang Yung-Fa Foundation. There are 483 permanent houses near the school belonging to three tribes, Dashe, Majia, and Haocha. Due to the most ancient heritages of Paiwan and Rukai in these three tribes, the school is full of cultural atmosphere. From modern and traditional perspectives, Evergreen Lily strives to establish and develop a long-lasting educational model to meet the expectation of the tribes, parents, and the public. This study is a case study of how to develop indigenous education in newly established schools after the Morakot Hurricane disaster to meet the concept of environmental education. The systematic curriculum construction of education and cultural integration and the systematic practice of curriculum practice will be discussed, and the concept and practice of tribal education curriculum and sustainable environmental education will be understood. This study found that this school integrates the spirit of natural philosophy, democratic education, ethnic and experimental education, and constructs a knowledge system that includes three levels of spiritual culture, institutional culture, and material culture, as well as six dimensions of life philosophy, natural ecology, organizational system, tribal literature and history, song and dance, and technical and artistic methods. Adhering to the concept of harmonious education and the sustainable common good, the development of school-based tribal academic courses accounts for about one-third of the total number of teaching sessions, and there are different cultural themes in grades one to six, and there are clear teaching modules to effectively enhance students' potential inspiration. The complete curriculum implementation model can be described as a model for the development of indigenous schools to sustainable environmental education.

Keywords: environmental education, indigenous education, sustainable development, school-based curriculum

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Authors: Byrad Yyelland, Robert Bianchi

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No longer the secret mark of outlaw bikers, criminals, and sailors, tattooing has become mainstream in much of the world. The current study showcases data gathered for a video documentary on the triangulated relationship connecting tattoos as a form of body modification, cultural norms, and personal meanings. This research has revealed that some religious belief systems, Buddhism in Thailand, is one example, connect tattooing with spirituality in an intimate manner. Buddhist monks provide tattoos using traditional bamboo implements and processes, and they pray over the tattoo, infusing magic into the tattoo and consequently, into the body of the receiver. In contrast, although there is no direct mention of tattooing in the Qur’an, many Islamic scholars argue that permanent tattooing is considered haram—forbidden for Muslims. Only the temporary henna is acceptable. In fact, tattooing is illegal in Qatar. Some Indigenous belief systems in Canada adopt a similar stance on the basis that we were all created by the Creator and as such, we do not have the right to alter what the Creator has made. Still other belief systems such as Spiritism in Brazil and mainstream Christianity in the West are more inclined to regard tattooing as a matter of personal choice. It is practically impossible for any culture to resist the dual impacts of time and globalization. Long term cultural change has resulted in mainstream acceptance of tattooing in the west and increased acceptance in Japan. Short-term cultural change is seen in Qatar where tattoos are on on public display amongst expats and migrant laborers. This tolerance of tattooed individuals was clearly evident with the choice of David Beckham as ambassador for the FIFA World Cup and during the corresponding tourist celebrations. Themes uncovered in this multicultural research also include individual meanings attributed to tattoo imagery and processes, experiences of personal empowerment, devotion to family, personal philosophy, gender identity, and aesthetics.

Keywords: culture, norms, tattooing, spirituality, personal motivations and personal meanings

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Authors: Pedro Esteban

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Most installations nowadays are exposed to many power quality problems, and they also face numerous challenges to comply with grid code and energy efficiency requirements. The reason behind this is that they are not designed to support nonlinear, non-balanced, and variable loads and generators that make up a large percentage of modern electric power systems. These problems and challenges become especially critical when designing green buildings and smart cities. These problems and challenges are caused by equipment that can be typically found in these installations like variable speed drives (VSD), transformers, lighting, battery chargers, double-conversion UPS (uninterruptible power supply) systems, highly dynamic loads, single-phase loads, fossil fuel generators and renewable generation sources, to name a few. Moreover, events like capacitor switching (from existing capacitor banks or passive harmonic filters), auto-reclose operations of transmission and distribution lines, or the starting of large motors also contribute to these problems and challenges. Active power filters (APF) are one of the fastest-growing power electronics technologies for solving power quality problems and meeting grid code and energy efficiency requirements for a wide range of segments and applications. They are a high performance, flexible, compact, modular, and cost-effective type of power electronics solutions that provide an instantaneous and effective response in low or high voltage electric power systems. They enable longer equipment lifetime, higher process reliability, improved power system capacity and stability, and reduced energy losses, complying with most demanding power quality and energy efficiency standards and grid codes. There can be found several types of active power filters, including active harmonic filters (AHF), static var generators (SVG), active load balancers (ALB), hybrid var compensators (HVC), and low harmonic drives (LHD) nowadays. All these devices can be used in applications in Smart Cities bringing several technical and economic benefits.

Keywords: power quality improvement, energy efficiency, grid code compliance, green buildings, smart cities

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Authors: F. Ruiz-Navarro, M. Matzner, G. Kobinia

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Background: Cerebral palsy (CP) encompasses the largest group of childhood movement disorders, the patterns and severity varies widely. Today, the management focuses only on a rehabilitation therapy that tries to secure the functions remained and prevents complications. However the treatments are not aimed to cure the disease. Stem cells (SCs) transplant via intrathecal is a new approach to the disease. Method: Our aim was to performed a pilot study under the condition of unproven treatment on clinical practice to assessed the safety and efficacy of Neuron Point-of-care Stem cell Therapy (N-POCST), an ambulatory procedure of autologous bone marrow derived SCs (BM-SCs) harvested from the posterior superior iliac crest undergo an on-site cell separation for intrathecal infusion via lumbar puncture. Results: 82 patients were treated in a period of 28 months, with a follow-up after 6 months. They had a mean age of 6,2 years old and male predominance (65,9%). Our preliminary results show that: A. No patient had any major side effects, B. Only 20% presented mild headache due to LP, C. 53% of the patients had an improvement in spasticity, D. 61% improved the coordination abilities, 23% improved the motor function, 15% improved the speech, 23% reduced the number of convulsive events with the same doses or less doses of anti-convulsive medication and 94% of the patients report a subjective general improvement. Conclusions: These results support previous worldwide publications that described the safety and effectiveness of autologous BM-SCs transplant for patients wit CP.

Keywords: autologous transplant, cerebral palsy, point of care, childhood movement disorders

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Authors: Jose Flores, Nadia Gamboa

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A proper water quality management requires the establishment of a monitoring network. Therefore, evaluation of the efficiency of water quality monitoring networks is needed to ensure high-quality data collection of critical quality chemical parameters. Unfortunately, in some Latin American countries water quality monitoring programs are not sustainable in terms of recording historical data or environmentally representative sites wasting time, money and valuable information. In this study, multivariate statistical techniques, such as principal components analysis (PCA) and hierarchical cluster analysis (HCA), are applied for identifying the most significant monitoring sites as well as critical water quality parameters in the monitoring network of the Jequetepeque River basin, in northern Peru. The Jequetepeque River basin, like others in Peru, shows socio-environmental conflicts due to economical activities developed in this area. Water pollution by trace elements in the upper part of the basin is mainly related with mining activity, and agricultural land lost due to salinization is caused by the extensive use of groundwater in the lower part of the basin. Since the 1980s, the water quality in the basin has been non-continuously assessed by public and private organizations, and recently the National Water Authority had established permanent water quality networks in 45 basins in Peru. Despite many countries use multivariate statistical techniques for assessing water quality monitoring networks, those instruments have never been applied for that purpose in Peru. For this reason, the main contribution of this study is to demonstrate that application of the multivariate statistical techniques could serve as an instrument that allows the optimization of monitoring networks using least number of monitoring sites as well as the most significant water quality parameters, which would reduce costs concerns and improve the water quality management in Peru. Main socio-economical activities developed and the principal stakeholders related to the water management in the basin are also identified. Finally, water quality management programs will also be discussed in terms of their efficiency and sustainability.

Keywords: PCA, HCA, Jequetepeque, multivariate statistical

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Authors: Allen Seylani

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Lysosome-dependent autophagy is a nutrient-deprivation-induced evolutionarily conserved intracellular recycling program that sequestrates intracellular cargo into autophagosomes (AP), which then fuse with lysosomes to form autolysosomes (ALs) for cargo digestion. To restore free lysosomes, autophagic lysosome reformation (ALR) is initiated by extrusion of tubular structures from autolysosomes at the final stage of autophagy, in a process called lysosomal tubulation (LT). This project aimed to investigate the molecular mechanism of GCN5L1 in LT and the following lysosomal signaling. GCN5L1 belongs to the BORC multiprotein complexes and is involved in controlling lysosomal trafficking; however, the effect of GCN5L1 on lysosome tubulation remains largely unknown. Genetic ablation of GCN5L1 in the mouse primary hepatocytes showed dramatically increased autolysosomes (ALs), decreased lysosome regeneration and absence of lysosomal tubulation. This phenotype suggests the possibility of disruption in lysosome tubulation, which results in the disturbance of the overall lysosome homeostasis. The formation of tubulars from ALs requires kinesin motor protein KIF5B. Immunoprecipitation was employed and confirmed the interaction of GCN5L1 with the ARL8B-KIF5B complex, which recruited KIF5B to ALs. At the same time, GCN5L1 interacted with WHAMM, which promotes the actin nucleation factor, which brings actin cytoskeleton to ALs and initiates LT. Furthermore, impaired LT in GCN5L1 deficient hepatocytes was restored by overexpression of GCN5L1, and this rescue effect was attenuated by knockdown of KIF5B. Additionally, lysosomal mTORC1 activity was upregulated in GCN5L1-/- hepatocytes, while inhibition of mTORC1 abrogated the GCN5L1 mediated rescue of LT in knockout hepatocytes. Altogether these findings revealed a novel mechanism of ALR, in which a simultaneous interaction of GCN5L1 with KIF5B and WHAMM is required for LT and downstream mTORC1 signaling.

Keywords: autophagy, autolysosome, GCN5L1, lysosome

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Authors: Lucija Pustahija, Christine Bandl, Wolfgang Kern, Christian Mitterer

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Concerning today´s ecological demands, producing reliable materials from sustainable resources is a continuously developing topic. Such an example is the production of carbon materials via pyrolysis of natural gases or biomass. The amazing properties of pyrolytic carbon are utilized in various fields, where in particular the application in building industry is a promising way towards the utilization of pyrolytic carbon and composites based on pyrolytic carbon. For many applications, surface modification of carbon is an important step in tailoring its properties. Therefore, in this paper, an investigation of different oxidation methods was performed to prepare the carbon surface before functionalizing it with organosilanes, which act as coupling agents for epoxy and polyurethane resins. Made in such a way, a building material based on carbon composites could be used as a lightweight, durable material that can be applied where water or air filtration / purification is needed. In this work, both wet and dry oxidation were investigated. Wet oxidation was first performed in solutions of nitric acid (at 120 °C and 150 °C) followed by oxidation in hydrogen peroxide (80 °C) for 3 and 6 h. Moreover, a hydrothermal method (under oxygen gas) in autoclaves was investigated. Dry oxidation was performed under plasma and corona discharges, using different power values to elaborate optimum conditions. Selected samples were then (in preliminary experiments) subjected to a silanization of the surface with amino and glycidoxy organosilanes. The functionalized surfaces were examined by X-ray photon spectroscopy and Fourier transform infrared spectroscopy spectroscopy, and by scanning electron microscopy. The results of wet and dry oxidation methods indicated that the creation of functionalities was influenced by temperature, the concentration of the reagents (and gases) and the duration of the treatment. Sequential oxidation in aq. HNO₃ and H₂O₂ results in a higher content of oxygen functionalities at lower concentrations of oxidizing agents, when compared to oxidizing the carbon with concentrated nitric acid. Plasma oxidation results in non-permanent functionalization on the carbon surface, by which it´s necessary to find adequate parameters of oxidation treatments that could enable longer stability of functionalities. Results of the functionalization of the carbon surfaces with organosilanes will be presented as well.

Keywords: building materials, dry oxidation, organosilanes, pyrolytic carbon, resins, surface functionalization, wet oxidation

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Authors: María Dolores Caro, Eugenio M. Fedriani, Ángel F. Tenorio

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When lorries transport dangerous goods, there exist some legal stipulations in the European Union for assuring the security of the rest of road users as well as of those goods being transported. At this respect, lorry drivers cannot park in usual parking areas, because they must use parking areas with special conditions, including permanent supervision of security personnel. Moreover, drivers are compelled to satisfy additional regulations about resting and driving times, which involve in the practical possibility of reaching the suitable parking areas under these time parameters. The “European Agreement concerning the International Carriage of Dangerous Goods by Road” (ADR) is the basic regulation on transportation of dangerous goods imposed under the recommendations of the United Nations Economic Commission for Europe. Indeed, nowadays there are no enough parking areas adapted for dangerous goods and no complete study have suggested the best locations to build new areas or to adapt others already existing to provide the areas being necessary so that lorry drivers can follow all the regulations. The goal of this paper is to show how many additional parking areas should be built in the Iberian Peninsula to allow that lorry drivers may park in such areas under their restrictions in resting and driving time. To do so, we have modeled the problem via graph theory and we have applied a new efficient algorithm which determines an optimal solution for the problem of locating new parking areas to complement those already existing in the ADR for the Iberian Peninsula. The solution can be considered minimal since the number of additional parking areas returned by the algorithm is minimal in quantity. Obviously, graph theory is a natural way to model and solve the problem here proposed because we have considered as nodes: the already-existing parking areas, the loading-and-unloading locations and the bifurcations of roads; while each edge between two nodes represents the existence of a road between both nodes (the distance between nodes is the edge's weight). Except for bifurcations, all the nodes correspond to parking areas already existing and, hence, the problem corresponds to determining the additional nodes in the graph such that there are less up to 100 km between two nodes representing parking areas. (maximal distance allowed by the European regulations).

Keywords: dangerous goods, parking areas, Iberian peninsula, graph-based modeling

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Authors: Hussien Ali, Mesfin Menza, Fitsum Hagos, Amare Haileslassie

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Climate change has perverse effects on agricultural productivity and natural resource base, negatively affecting the well-being of the households and communities. The government and NGOs promote climate smart agricultural (CSA) practices to help farmers adapt to and mitigate the negative effects of climate change. This study aims to identify widely available CSA practices and examine their impacts on food security and multi-dimensional poverty of rural farm households in the Central Rift Valley, Ethiopia. Using three-stage proportional to size sampling procedure, the study randomly selected 278 households from two kebeles from four districts each. A cross-sectional data of 2020/21 cropping season was collected using structured and pretested survey questionnaire. Food consumption score, dietary diversity score, food insecurity experience scale, and multidimensional poverty index were calculated to measure households’ welfare indicators. Multinomial endogenous switching regression model was used to assess average treatment effects of CSA on these outcome indicators on adopter and non-adopter households. The results indicate that the widely adopted CSA practices in the area are conservation agriculture, soil fertility management, crop diversification, and small-scale irrigation. Adopter households have, on average, statistically higher food consumption score, dietary diversity score and lower food insecurity access scale than non-adopters. Moreover, adopter households, on average, have lower deprivation score in multidimensional poverty compared to non-adopter households. Up scaling the adoption of CSA practices through the improvement of households’ implementation capacity and better information, technical advice, and innovative financing mechanisms is advised. Up scaling CSA practices can further promote achieving global goals such as SDG 1, SDG 2, and SDG 13 targets, aimed to end poverty and hunger and mitigate the adverse impacts of climate change, respectively.

Keywords: climate-smart agriculture, food security, multidimensional poverty, upscaling CSA, Ethiopia

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Authors: Percy Galvez, Anatoly Petukhin, Paul Somerville, Ken Miyakoshi, Kojiro Irikura, Daniel Peter

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Physics-based dynamic rupture modelling is necessary for estimating parameters such as rupture velocity and slip rate function that are important for ground motion simulation, but poorly resolved by observations, e.g. by seismic source inversion. In order to generate a large number of physically self-consistent rupture models, whose rupture process is consistent with the spatio-temporal heterogeneity of past earthquakes, we use multicycle simulations under the heterogeneous rate-and-state (RS) friction law for a 45deg dip-slip fault. We performed a parametrization study by fully dynamic rupture modeling, and then, a set of spontaneous source models was generated in a large magnitude range (Mw > 7.0). In order to validate rupture models, we compare the source scaling relations vs. seismic moment Mo for the modeled rupture area S, as well as average slip Dave and the slip asperity area Sa, with similar scaling relations from the source inversions. Ground motions were also computed from our models. Their peak ground velocities (PGV) agree well with the GMPE values. We obtained good agreement of the permanent surface offset values with empirical relations. From the heterogeneous rupture models, we analyzed parameters, which are critical for ground motion simulations, i.e. distributions of slip, slip rate, rupture initiation points, rupture velocities, and source time functions. We studied cross-correlations between them and with the friction weakening distance Dc value, the only initial heterogeneity parameter in our modeling. The main findings are: (1) high slip-rate areas coincide with or are located on an outer edge of the large slip areas, (2) ruptures have a tendency to initiate in small Dc areas, and (3) high slip-rate areas correlate with areas of small Dc, large rupture velocity and short rise-time.

Keywords: earthquake dynamics, strong ground motion prediction, seismic engineering, source characterization

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Authors: Evangelia Tsampali, Evangelos Yfantidis, Andreas Ioakim, Maria Stefanidou

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The purpose of this paper is the characterization of the effects of crystalline admixtures on concrete. Crystallites, aided by the presence of humidity, form idiomorphic crystals that block cracks and pores resulting in reduced porosity. In this project, two types of crystallines have been employed. The hydrophilic nature of crystalline admixtures helps the components to react with water and cement particles in the concrete to form calcium silicate hydrates and pore-blocking precipitates in the existing micro-cracks and capillaries. The underlying mechanism relies on the formation of calcium silicate hydrates and the resulting deposits of these crystals become integrally bound with the hydrated cement paste. The crystalline admixtures continue to activate throughout the life of the composite material when in the presence of moisture entering the concrete through hairline cracks, sealing additional gaps. The resulting concrete exhibits significantly increased resistance to water penetration under stress. Admixtures of calcium aluminates can also contribute to this healing mechanism in the same manner. However, this contribution is negligible compared to the calcium silicate hydrates due to the abundance of the latter. These crystalline deposits occur throughout the concrete volume and are a permanent part of the concrete mass. High-performance fibre reinforced cementitious composite (HPFRCC) were produced in the laboratory. The specimens were exposed in three healing conditions: water immersion until testing at 15 °C, sea water immersion until testing at 15 °C, and wet/dry cycles (immersion in tap water for 3 days and drying for 4 days). Specimens were pre-cracked at 28 days, and the achieved cracks width were in the range of 0.10–0.50 mm. Furthermore, microstructure observations and Ultrasonic Pulse Velocity tests have been conducted. Based on the outcomes, self-healing related indicators have also been defined. The results show almost perfect healing capability for specimens healed under seawater, better than for specimens healed in water while inadequate for the wet/dry exposure in both of the crystalline types.

Keywords: autogenous self-healing, concrete, crystalline admixtures, ultrasonic pulse velocity test

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Authors: Bulcha Belay Etana, Benny Malengier, Janarthanan Krishnamoorthy, Timothy Kwa, Lieva Vanlangenhove

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Electromyography measures the electrical activity of muscles using surface electrodes or needle electrodes to monitor various disease conditions. Recent developments in the signal acquisition of electromyograms using textile electrodes facilitate wearable devices, enabling patients to monitor and control their health status outside of healthcare facilities. Here, we have developed and tested wearable textile electrodes to acquire electromyography signals from patients suffering from Parkinson’s disease and incorporated a feedback-control system to relieve muscle cramping through thermal stimulus. In brief, the textile electrodes made of stainless steel was knitted into a textile fabric as a sleeve, and their electrical characteristic, such as signal-to-noise ratio, was compared with traditional electrodes. To relieve muscle cramping, a heating element made of stainless-steel conductive yarn sewn onto a cotton fabric, coupled with a vibration system, was developed. The system integrated a microcontroller and a Myoware muscle sensor to activate the heating element as well as the vibration motor when cramping occurred. At the same time, the element gets deactivated when the muscle cramping subsides. An optimum therapeutic temperature of 35.5°C is regulated and maintained continuously by a heating device. The textile electrode exhibited a signal-to-noise ratio of 6.38dB, comparable to that of the traditional electrode’s value of 7.05 dB. For a given 9 V power supply, the rise time for the developed heating element was about 6 minutes to reach an optimum temperature.

Keywords: smart textile system, wearable electronic textile, electromyography, heating textile, vibration therapy, Parkinson’s disease

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Authors: Rachida Gherbi-Salmi, Abdelkarim Si Bachir, Salah Eddine Doumandji

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The Cattle Egret is a predatory bird with an insectivorous diet. It feeds in open environments (wetlands, meadows, farmland and cultivated land). Few studies have determined the status of its prey (useful or harmful species for agriculture). Hence, our study was carried out in the Bejaia region (Algeria). It consisted of examining adult rejection pellets collected in a heronry located in the lower Soummam Valley (El-Kseur), which has been a permanent habitat for over 30 years. Field sampling was carried out during the juvenile rearing period in 1998 (wet spring) and 2020 (almost dry spring). Examination of 50 pellets at a rate of 10 per month (May - September) in 1998 revealed the presence of 2,661 prey belonging to 170 species, i.e., an average of 53.36 prey per pellet. The results reveal that the diet of this Ardeidae consists mainly of Insecta (95.09%). Arachnida was a distant second (4.05%). Vertebrates (Reptilia and Rodentia) (0.82%) and myriapods (0.04%) are rare prey. We counted 2,154 plant pests (80.27%), of which 2,138 were insects (99.27%) and 0.73% rodents (Mus spretus). Of the plant-pest insects identified, 1385 were Orthoptera (64.78%). Fourmicidae came second (13.05%), and Coleoptera third (12.82%). Dermaptera, on the other hand, accounted for only 7.86%. Analysis of 30 rejection pellets, 10 per month (May - July) in 2020, identified 1,330 prey belonging to 80 species, an average of 44.33 prey per pellet. The results reveal that its diet is essentially made up of Insecta (94.81%). These are followed by Vertebrata (3.01%) and Arachnida (2.18%). We counted 1156 plant pests (86.82%), of which 86.02% are Insecta. Orthoptera are the most frequent (45.72%). They are followed by Dermaptera (33.74%) and Coleoptera (18.44%). The present study highlighted the importance of plant pests consumed by the Cattle Egret (80.27% in 1998 and 86.82% in 2020), which are far more numerous and diverse than auxiliary prey and pollinators. This confirms the bird's status as a biological control agent in the lower Soummam valley. It is, therefore, worth pointing out that this species deserves to be protected.

Keywords: bubulcus ibis, diet, lower soummam valley, insect crop pests

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Authors: Maliha Ahmed Suleman, Sidra Ahmed Suleman

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Introduction: The use of pacifiers is common amongst infants and young children as a comforting behavior. These non-nutritive sucking habits can be detrimental to the developing occlusion should they persist while the permanent dentition is established. Orthodontic pacifiers have been recommended as an alternative to conventional pacifiers as they are considered to have less interference with orofacial development. However, there is a lack of consensus on whether this is true. Aim and objectives: To review the prevalence of malocclusion associated with the use of orthodontic pacifiers. Methodology: Literature was identified through a rigorous search of the Embase, Pubmed, CINAHL, and Cochrane Library databases. Articles published from 2000 onwards were included. In total, 5 suitable papers were identified. Results: One study showed that the use of orthodontic pacifiers increased the risk of malocclusion, as seen through a greater prevalence of accentuated overjet, posterior crossbites, and anterior open bites in comparison to individuals who did not use pacifiers. However, this study found that there was a clinically significant reduction in the prevalence of anterior open bites amongst orthodontic pacifier users in comparison to conventional pacifier users. Another study found that both types of pacifiers lead to malocclusion; however, they found no difference in the mean overjet and prevalence of anterior open bites amongst conventional and orthodontic pacifier users. In contrast, one study suggested that orthodontic pacifiers do not seem to be related to the development of malocclusions in the primary dentitions, and using them between the ages of 0-3 months was actually beneficial as it prevents thumb-sucking habits. One of the systemic reviews concluded that orthodontic pacifiers do not seem to reduce the occurrence of posterior crossbites; however, they could reduce the development of open bites by virtue of their thin neck design. Whereas another systematic review concluded that there were no differences as to the effects on the stomatognathic system when comparing conventional and orthodontic pacifiers. Conclusion: There is limited and conflicting evidence to support the notion that orthodontic pacifiers can reduce the prevalence of malocclusion when compared to conventional pacifiers. Well-designed randomized controlled trials are required in the future in order to thoroughly assess the effects of orthodontic pacifiers on the developing occlusion and orofacial structures.

Keywords: orthodontics, pacifier, malocclusion, review

Procedia PDF Downloads 76

Authors: Tukur Daiyabu Abdulkadir, Wan Ishak Wan Ismail, Muhammad Saufi Mohd Kassim

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Seed singulation and accuracy in seed spacing are the major challenges associated with the adoption of mechanical seeder for system of rice intensification. In this research the metering system of a pneumatic planter was modified and automated for increase precision to meet the demand of system of rice intensification SRI. The chain and sprocket mechanism of a conventional vacuum planter were now replaced with an electro mechanical system made up of a set of servo motors, limit switch, micro controller and a wheel divided into 10 equal angles. The circumference of the planter wheel was determined based on which seed spacing was computed and mapped to the angles of the metering wheel. A program was then written and uploaded to arduino micro controller and it automatically turns the seed plates for seeding upon covering the required distance. The servo motor was calibrated with the aid of labVIEW. The machine was then calibrated using a grease belt and varying the servo rpm through voltage variation between 37 rpm to 47 rpm until an optimum value of 40 rpm was obtained with a forward speed of 5 kilometers per hour. A pressure of 1.5 kpa was found to be optimum under which no skip or double was recorded. Precision in spacing (coefficient of variation), miss index, multiple index, doubles and skips were investigated. No skip or double was recorded both at laboratory and field levels. The operational parameters under consideration were both evaluated at laboratory and field. Even though there was little variation between the laboratory and field values of precision in spacing, multiple index and miss index, the different is not significant as both laboratory and field values fall within the acceptable range.

Keywords: automation, calibration, pneumatic seed planter, system of rice intensification

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Authors: Muluken Biadgelegn Wollele, Mebratu Assaye Mengistu

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Nanotechnology has created new opportunities for improving industrial efficiency and performance. One of the proposed approaches to improving the effectiveness of temperature exchangers is the use of nanofluids to improve heat transfer performance. The thermal conductivity of nanoparticles, as well as their size, diameter, and volume concentration, all played a role in influencing the rate of heat transfer. Nanofluids are commonly used in automobiles, energy storage, electronic component cooling, solar absorbers, and nuclear reactors. Convective heat transfer must be improved when designing thermal systems in order to reduce heat exchanger size, weight, and cost. Using roughened surfaces to promote heat transfer has been tried several times. Thus, both active and passive heat transfer methods show potential in terms of heat transfer improvement. There will be an added advantage of enhanced heat transfer due to the two methods adopted; however, pressure drop must be considered during flow. Thus, the current research aims to increase heat transfer by adding a twisted tap insert in a plain tube using a working fluid hybrid nanofluid (Al₂O₃-Cu) with a base fluid of water. A circular duct with inserts, a tube length of 3 meters, a hydraulic diameter of 0.01 meters, and tube walls with a constant heat flux of 20 kW/m² and a twist ratio of 125 was used to investigate Al₂O₃-Cu/H₂O hybrid nanofluid with inserts. The temperature distribution is better than with conventional tube designs due to stronger tangential contact and swirls in the twisted tape. The Nusselt number values of plain twisted tape tubes are 1.5–2.0 percent higher than those of plain tubes. When twisted tape is used instead of plain tube, performance evaluation criteria improve by 1.01 times. A heat exchanger that is useful for a number of heat exchanger applications can be built utilizing a mixed flow of analysis that incorporates passive and active methodologies.

Keywords: nanofluids, active method, passive method, Nusselt number, performance evaluation criteria

Procedia PDF Downloads 69

Authors: Alexandros Lioulemes, Michail Theofanidis, Varun Kanal, Konstantinos Tsiakas, Maher Abujelala, Chris Collander, William B. Townsend, Angie Boisselle, Fillia Makedon

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This paper presents a home-based robot-rehabilitation instrument, called ”MAGNI Dynamics”, that utilized a vision-based kinematic/dynamic module and an adaptive haptic feedback controller. The system is expected to provide personalized rehabilitation by adjusting its resistive and supportive behavior according to a fuzzy intelligence controller that acts as an inference system, which correlates the user’s performance to different stiffness factors. The vision module uses the Kinect’s skeletal tracking to monitor the user’s effort in an unobtrusive and safe way, by estimating the torque that affects the user’s arm. The system’s torque estimations are justified by capturing electromyographic data from primitive hand motions (Shoulder Abduction and Shoulder Forward Flexion). Moreover, we present and analyze how the Barrett WAM generates a force-field with a haptic controller to support or challenge the users. Experiments show that by shifting the proportional value, that corresponds to different stiffness factors of the haptic path, can potentially help the user to improve his/her motor skills. Finally, potential areas for future research are discussed, that address how a rehabilitation robotic framework may include multisensing data, to improve the user’s recovery process.

Keywords: human-robot interaction, kinect, kinematics, dynamics, haptic control, rehabilitation robotics, artificial intelligence

Procedia PDF Downloads 321

Authors: Sarah K. Amer, Walaa Alaa

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Epilepsy is an important cause of mortality and morbidity, according to WHO statistics. It is characterized by the presence of frequent seizures occurring more than 24 hours apart. Carbamazepine (CBZ) is considered first-line treatment for epilepsy. However, reports have shown that CBZ oral formulations failed to achieve optimum systemic delivery, minimize side effects, and enhance patient compliance. Besides, the literature has signified the lack of therapeutically efficient CBZ transdermal formulation and the urge for its existence owing to its ease and convenient method of application and highlighted capability to attain higher bioavailability and more extended-release profiles compared to conventional oral CBZ tablets. This work aims to prepare CBZ microspheres (MS) that are embedded in a transdermal gel containing Vitamin B to be co-delivered. MS were prepared by emulsion-solvent diffusion method using Eudragit S as core forming polymer and hydroxypropyl methylcellulose (HPMC) polymer. The MS appeared to be spherical and porous in nature, offering a large surface area and high entrapment efficiency of CBZ. The transdermal gel was prepared by solvent-evaporation technique using HPMC that, offered high entrapment efficiency and Eudragit S that provided an extended-release profile. Polyethylene glycol, Span 80 and Pyridoxine were also added. Data indicated that combinations of CBZ with pyridoxine can reduce epileptic seizures without affecting motor coordination. Extended-release profiles were evident for this system. The patches were furthermore tested for thickness, moisture content, folding endurance, spreadability and viscosity measurements. This novel pharmaceutical formulation would be of great influence on seizure control, offering better therapeutic effects.

Keywords: epilepsy, carbamazepine, pyridoxine, transdermal

Procedia PDF Downloads 50

Authors: Kodo Sektani, Apostolos Tsouvalas, Andrei Metrikine

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The reassessment of existing movable bridges in The Netherlands has created the need for acceptance/rejection criteria to assess whether the machineries are meet certain design demands. However, the existing design code defines a different limit state design, meant for new machineries which is based on a simple linear spring-mass model. Observations show that existing bridges do not confirm the model predictions. In fact, movable bridges are nonlinear systems consisting of mechanical components, such as, gears, electric motors and brakes. Next to that, each movable bridge is characterized by a unique set of parameters. However, in the existing code various variables that describe the physical characteristics of the bridge are neglected or replaced by partial factors. For instance, the damping ratio ζ, which is different for drawbridges compared to bascule bridges, is taken as a constant for all bridge types. In this paper, a model is developed that overcomes some of the limitations of existing modelling approaches to capture the dynamics of the powertrain of a class of bridge machineries First, a semidefinite dynamic model is proposed, which accounts for stiffness, damping, and some additional variables of the physical system, which are neglected by the code, such as nonlinear braking torques. The model gives an upper bound of the peak forces/torques occurring in the powertrain during emergency braking. Second, a discrete nonlinear dynamic model is discussed, with realistic motor torque characteristics during normal operation. This model succeeds to accurately predict the full time history of the occurred stress state of the opening and closing cycle for fatigue purposes.

Keywords: Dynamics of movable bridges, Bridge machinery, Powertrains, Torque measurements

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Authors: S. Sandri, G. M. Contessa, C. Poggi

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An experimental nuclear fusion device could be seen as a step toward the development of the future nuclear fusion power plant. If compared with other possible solutions to the energy problem, nuclear fusion has advantages that ensure sustainability and security. In particular considering the radioactivity and the radioactive waste produced, in a nuclear fusion plant the component materials could be selected in order to limit the decay period, making it possible the recycling in a new reactor after about 100 years from the beginning of the decommissioning. To achieve this and other pertinent goals many experimental machines have been developed and operated worldwide in the last decades, underlining that radiation protection and workers exposure are critical aspects of these facilities due to the high flux, high energy neutrons produced in the fusion reactions. Direct radiation, material activation, tritium diffusion and other related issues pose a real challenge to the demonstration that these devices are safer than the nuclear fission facilities. In Italy, a limited number of fusion facilities have been constructed and operated since 30 years ago, mainly at the ENEA Frascati Center, and the radiation protection approach, addressed by the national licensing requirements, shows that it is not always easy to respect the constraints for the workers' exposure to ionizing radiation. In the current analysis, the main radiation protection issues encountered in the Italian Fusion facilities are considered and discussed, and the technical and legal requirements are described. The licensing process for these kinds of devices is outlined and compared with that of other European countries. The following aspects are considered throughout the current study: i) description of the installation, plant and systems, ii) suitability of the area, buildings, and structures, iii) radioprotection structures and organization, iv) exposure of personnel, v) accident analysis and relevant radiological consequences, vi) radioactive wastes assessment and management. In conclusion, the analysis points out the needing of a special attention to the radiological exposure of the workers in order to demonstrate at least the same level of safety as that reached at the nuclear fission facilities.

Keywords: fusion facilities, high energy neutrons, licensing process, radiation protection

Procedia PDF Downloads 349

Authors: Radwa Talaat Mohammed El-Shorbagy, Alaa El-Din Balbaa, Khaled Ayad, Waleed Red

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Introduction: Ankle sprain is a common lower limb injury that is complicated by high recurrence rate. The cause of recurrence is not clear; however, changes in motor control have been postulated. Objective: To determine the contribution of proximal hip strategy to dynamic balance control in patients with recurrent ankle sprain. Methods: Fifteen subjects with recurrent ankle sprain (group A) and fifteen healthy control subjects (group B) participated in this study. Abductor-adductors as well as flexor-extensor hip musculatures control was abolished by fatigue using the Biodex Isokinetic system. Dynamic balance was measured before and after fatigue by the Biodex Balance system Results: Repeated measures MANOVA was used to compare between and within group differences. In group A fatiguing of hip muscles (flexors-extensors and abductors-adductors) increased overall stability index (OASI), anteroposterior stability index (APSI) and mediolateral stability index (MLSI) significantly (p=0.00) whereas; in group B fatiguing of hip flexors-extensors increased significantly OASI and APSI only (p= 0.017, 0.010; respectively) while fatiguing of hip abductors-adductors has no significant effect on these variables. Moreover, patients with ankle sprain had significantly lower dynamic balance after hip muscles fatigue compared to the control group. Specifically, after hip flexor-extensor fatigue, the OASI, APSI and MLSI were increased significantly than those of the control values (p=0.002, 0.011, and 0.003, respectively) whereas fatiguing of hip abductors-adductors increased significantly in OASI and APSI only (p=0.012, 0.026, respectively). Conclusion: To maintain dynamic balance, patients with recurrent ankle sprain seem to relay more on the hip strategy.

Keywords: ankle sprain, hip muscles fatigue, dynamic balance

Procedia PDF Downloads 482

Authors: Abdulkarim Yusuf

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Motivation: A crucial but difficult goal for governments and policymakers in Nigeria in recent years has been the sustainability of economic growth. This goal must be accomplished by regulating or lowering greenhouse gas emissions, which calls for switching to a low- or zero-carbon production system. The lack of in-depth empirical studies on the environmental impact of socioeconomic variables on Nigeria and a number of unresolved issues from earlier research is what led to the current study. Objective: This study fills an important empirical gap by investigating the existence of an Environmental Kuznets Curve hypothesis and the long and short-run dynamic impact of socioeconomic variables on ecological sustainability in Nigeria. Data and method: Annual time series data covering the period 1980 to 2020 and the Autoregressive Distributed Lag technique in the presence of structural breaks were adopted for this study. Results: The empirical findings support the existence of the environmental Kuznets curve hypothesis for Nigeria in the long and short run. Energy consumption and total import exacerbate environmental deterioration in the long and short run, whereas total export improves environmental quality in the long and short run. Financial development, which contributed to a conspicuous decrease in the level of environmental destruction in the long run, escalated it in the short run. In contrast, urbanization caused a significant increase in environmental damage in the long run but motivated a decrease in biodiversity loss in the short run. Implications: The government, policymakers, and all energy stakeholders should take additional measures to ensure the implementation and diversification of energy sources to accommodate more renewable energy sources that emit less carbon in order to promote efficiency in Nigeria's production processes and lower carbon emissions. In order to promote the production and trade of environmentally friendly goods, they should also revise and strengthen environmental policies. With affordable, dependable, and sustainable energy use for higher productivity and inclusive growth, Nigeria will be able to achieve its long-term development goals of good health and wellbeing.

Keywords: economic growth, energy consumption, environmental degradation, environmental Kuznets curve, urbanization, Nigeria

Procedia PDF Downloads 46

Authors: Timine Suoware, Sylvester Edelugo, Charles Amgbari

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The susceptibility of natural fibre polymer composites to flame has necessitated research to improve and develop flame retardant (FR) to delay the escape of combustible volatiles. Previous approaches relied mostly on FR such as aluminium tri-hydroxide (ATH) and ammonium polyphosphate (APP) to improve fire performances of wood sawdust polymer composites (WSPC) with emphasis on non-structural building applications. In this paper, APP was modified with gum Arabic powder (GAP) and then hybridized with ATH at 0, 12 and 18% loading ratio to form new FR species; WSPC12%APP-GAP and WSPC18%ATH/APP-GAP. The FR species were incorporated in wood sawdust waste reinforced in polyester resin to form panels for fireproof doors. The panels were produced using hand lay compression moulding technique and cured at room temperature. Specimen cut from panels were then tested for tensile strength (TS), flexural strength (FS) and impact strength (IS) using universal testing machine and impact tester; thermal stability using (TGA/DSC 1: Metler Toledo); time-to-ignition (Tig), heat release rates (HRR); peak HRR (HRRp), average HRR (HRRavg), total HRR (THR), peak mass loss rate (MLRp), average smoke production rate (SPRavg) and carbon monoxide production (COP ) were obtained using the cone calorimeter apparatus. From the mechanical properties obtained, improvements of IS for the panels were not noticeable whereas TS and FS for WSPC12%APP-GAP respectively stood at 12.44 MPa and 85.58 MPa more than those without FR (WSPC0%). For WSC18%ATH/APP-GAP TS and FS respectively stood at 16.45 MPa and 50.49 MPa more compared to (WSPC0%). From the thermal analysis, the panels did not exhibit any significant change as early degradation was observed. At 900 OC, the char residues improved by 15% for WSPC12%APP-GAP and 19% for WSPC18%ATH/APP-GAP more than (WSC0%) at 5%, confirming the APP-GAP to be a good FR. At 50 kW/m2 heat flux (HF), WSPC12%APP-GAP improved better the fire behaviour of the panels when compared to WSC0% as follows; Tig = 46 s, HRRp = 56.1 kW/2, HRRavg = 32.8 kW/m2, THR = 66.6 MJ/m2, MLRp = 0.103 g/s, TSR = 0.04 m2/s and COP = 0.051 kg/kg. These were respectively more than WSC0%. It can be concluded that the new concept of modifying FR with GAP in WSC could meet the requirement of a fireproof door for building applications.

Keywords: composite, flame retardant, wood sawdust, fireproof doors

Procedia PDF Downloads 105

Authors: Taleb L., Benarbia M., Boutira F. M., Allam H., Boukerche A.

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Introduction and purpose of the study: Meningiomas are the most common non-glial intracranial tumors in adults, accounting for approximately 30% of all central nervous system tumors. The aim of our study is to determine the epidemiological, clinical, therapeutic, and evolutionary characteristics of a cohort of patients with intracranial meningioma treated with radiotherapy at the Emir Abdelkader Cancer Center in Oran. Material and methods: This is a retrospective study of 44 patients during the period from 2014 to 2020. The overall survival and relapse-free survival curves were calculated using the Kaplan-Meier method. Results and statistical analysis: The median age of the patients was 49 years [21-76 years] with a clear female predominance (sex ratio=2.4). The average diagnostic delay was seven months [2 to 24 months], the circumstances of the discovery of which were dominated by headaches in 54.5% of cases (n=24), visual disturbances in 40.9% (n=18), and motor disorders in 15.9% (n=7). The seat of the tumor was essentially at the level of the base of the skull in 52.3% of patients (n=23), including 29.5% (n=13) at the level of the cavernous sinus, 27.3% (n=12) at the parasagittal level and 20.5% (n=9) at the convexity. The diagnosis was confirmed surgically in 36 patients (81.8%) whose anatomopathological study returned in favor of grades I, II, and III in respectively 40.9%, 29.5%, and 11.4% of the cases. Radiotherapy was indicated postoperatively in 45.5% of patients (n=20), exclusive in 27.3% (n=12) and after tumor recurrence in 27.3% of cases (n=18). The irradiation doses delivered were as follows: 50 Gy (20.5%), 54 Gy (65.9%), and 60 Gy (13.6%). With a median follow-up of 69 months, the probabilities of relapse-free survival and overall survival at three years are 93.2% and 95.4%, respectively, whereas they are 71.2% and 80.7% at five years. Conclusion: Meningiomas are common primary brain tumors. Most often benign but can also progress aggressively. Their treatment is essentially surgical, but radiotherapy retains its place in specific situations, allowing good tumor control and overall survival.

Keywords: diagnosis, meningioma, surgery, radiotherapy, survival

Procedia PDF Downloads 95