Search results for: micro and small enterprises

Authors: Tawanda Mushiri, Charles Mbohwa

Abstract:

When an external load is applied to one of its ends, a pipe’s bends cross section tends to deform significantly both in and out of its end plane. This shell type behaviour characteristic of pipe bends and mainly due to their curves geometry accounts for their greater flexibility. This added flexibility is also accompanied by stressed and strains that are much higher than those present in a straight pipe. The primary goal of this research is to study the elastic-plastic behaviour of pipe bends under out of plane moment loading. It is also required to study the effects of changing the value of the pipe bend factor and the value of the internal pressure on that behaviour and to determine the value of the limit moments in each case. The results of these analyses are presented in the form of load deflection plots for each load case belonging to each model. From the load deflection curves, the limit moments of each case are obtained. The limit loads are then compared to those computed using some of the analytical and empirical equation available in the literature. The effects of modelling parameters are also studied. The results obtained from small displacement and large displacement analyses are compared and the effects of using a strain hardened material model are also investigated. To better understand the behaviour of pipe elbows under out of plane bending and internal pressure, it was deemed important to know how the cross section deforms and to study the distribution of stresses that cause it to deform in a particular manner. An elbow with pipe bend factor h=0.1 to h=1 is considered and the results of the detailed analysis are thereof examined.

Keywords: elasto-plastic, finite element analysis, pipe bends, simulation

Procedia PDF Downloads 325

Authors: Zaid Jamal Saeed Almahmoud

Abstract:

Our increasing reliance on electricity, with inefficient consumption trends, has resulted in several economical and environmental threats. These threats include wasting billions of dollars, draining limited resources, and elevating the impact of climate change. As a solution, the smart grid is emerging as the future power grid, with smart techniques to optimize power consumption and electricity generation. Minimizing the peak power consumption under a fixed delay requirement is a significant problem in the smart grid. In addition, matching demand to supply is a key requirement for the success of the future electricity. In this work, we consider the problem of minimizing the peak demand under appliances constraints by scheduling power jobs with uniform release dates and deadlines. As the problem is known to be NP-Hard, we propose two versions of a heuristic algorithm for solving this problem. Our theoretical analysis and experimental results show that our proposed heuristics outperform existing methods by providing a better approximation to the optimal solution. In addition, we consider dynamic pricing methods to minimize the peak load and match demand to supply in the smart grid. Our contribution is the proposal of generic, as well as customized pricing heuristics to minimize the peak demand and match demand with supply. In addition, we propose optimal pricing algorithms that can be used when the maximum deadline period of the power jobs is relatively small. Finally, we provide theoretical analysis and conduct several experiments to evaluate the performance of the proposed algorithms.

Keywords: heuristics, optimization, smart grid, peak demand, power supply

Procedia PDF Downloads 88

Authors: Malinwo Estone Ayikpa

Abstract:

With the rapid increase of grid-connected PV systems over the last decades, genuine challenges have arisen for engineers and professionals of energy field in the planning and operation of existing distribution networks with the integration of new generation sources. However, the conventional distribution network, in its design was not expected to receive other generation outside the main power supply. The tools generally used to analyze the networks become inefficient and cannot take into account all the constraints related to the operation of grid-connected PV systems. Some of these constraints are voltage control difficulty, reverse power flow, and especially voltage unbalance which could be due to the poor distribution of single-phase PV systems in the network. In order to analyze the impact of the connection of small and large number of PV systems to the distribution networks, this paper presents an efficient optimization tool that minimizes voltage unbalance in three-phase distribution networks with active and reactive power injections from the allocation of single-phase and three-phase PV plants. Reactive power can be generated or absorbed using the available capacity and the adjustable power factor of the inverter. Good reduction of voltage unbalance can be achieved by reactive power control of the PV systems. The presented tool is based on the three-phase current injection method and the PV systems are modeled via an equivalent circuit. The primal-dual interior point method is used to obtain the optimal operating points for the systems.

Keywords: Photovoltaic system, Primal-dual interior point method, Three-phase optimal power flow, Voltage unbalance

Procedia PDF Downloads 332

Authors: Kanika Chowdhary, Satyawati Sharma

Abstract:

Endophytic microbes are hosted inside plants in a symbiotic and hugely benefitting relationship. Exploring agriculturally beneficial endophytes is quite a prospective field of research. In the present work fungal endophytes associated with aromatic plant Ocimum basicilium L. were investigated for biocontrol potential. The anti-plant pathogenic activity of fungal endophytes was tested against causal agent of stem rot Sclerotinia sclerotiorum. 75 endophytic fungi were recovered through culture-dependent approach. Fungal identification was performed both microscopically and by rDNA ITS sequencing. Curvuaria lunata (Sb-6) and Colletotrichum lindemuthianum (Sb-8) inhibited 86% and 72% mycelia growth of S. sclerotinia on Sabouraud dextrose agar medium at 7.4 pH. Small-scale fermentation was carried out on sterilised oatmeal grain medium. In another set of experiment, fungi were grown in oatmeal grain medium amended with certain biostimulants such as aqueous seaweed extract (10% v/w); methanolic seaweed extract (5% v/w); cow urine (20% v/w); biochar (10% w/w) in triplicate along with control of each to ascertain the degree of metabolic difference and anti-plant pathogenic activity induced. Phytochemically extracts of both the fungal isolates showed the presence of flavanoids, phenols, tannins, alkaloids and terpenoids. Ethylacetate extract of C. lunata and C. lindemuthianum suppressed S. sclerotinia conidial germination at IC50 values of 0.514± 0.02 and 0.913± 0.04 mg/ml. Therefore, fungal endophytes of O. basicilium are highly promising bio-resource agent, which can be developed further for sustainable agriculture.

Keywords: endophytic fungi, ocimum basicilium, sclerotinia sclerotiorum, biostimulants

Procedia PDF Downloads 176

Authors: Devanjan Bhattacharya, Jitka Komarkova

Abstract:

The research describes the implementation of a novel and stand-alone system for dynamic hazard warning. The system uses all existing infrastructure already in place like mobile networks, a laptop/PC and the small installation software. The geospatial dataset are the maps of a region which are again frugal. Hence there is no need to invest and it reaches everyone with a mobile. A novel architecture of hazard assessment and warning introduced where major technologies in ICT interfaced to give a unique WebGIS based dynamic real time geohazard warning communication system. A never before architecture introduced for integrating WebGIS with telecommunication technology. Existing technologies interfaced in a novel architectural design to address a neglected domain in a way never done before–through dynamically updatable WebGIS based warning communication. The work publishes new architecture and novelty in addressing hazard warning techniques in sustainable way and user friendly manner. Coupling of hazard zonation and hazard warning procedures into a single system has been shown. Generalized architecture for deciphering a range of geo-hazards has been developed. Hence the developmental work presented here can be summarized as the development of internet-SMS based automated geo-hazard warning communication system; integrating a warning communication system with a hazard evaluation system; interfacing different open-source technologies towards design and development of a warning system; modularization of different technologies towards development of a warning communication system; automated data creation, transformation and dissemination over different interfaces. The architecture of the developed warning system has been functionally automated as well as generalized enough that can be used for any hazard and setup requirement has been kept to a minimum.

Keywords: geospatial, web-based GIS, geohazard, warning system

Procedia PDF Downloads 408

Authors: Hanan Al-Jabri

Abstract:

Simultaneous interpreting is deemed to be the most challenging mode of interpreting by many scholars. The special constraints involved in this task including time constraints, different linguistic systems, and stress pose a great challenge to most interpreters. These constraints are likely to maximise when the interpreting task is done live on TV. The TV interpreter is exposed to a wide variety of audiences with different backgrounds and needs and is mostly asked to interpret high profile tasks which raise his/her levels of stress, which further complicate the task. Under these constraints, which require fast and efficient performance, TV interpreters of four TV channels were asked to render Trump's victory speech into Arabic. However, they had also to deal with the burden of rendering English emotive overtones employed by the speaker into a whole different linguistic system. The current study aims at investigating the way TV interpreters, who worked in the simultaneous mode, handled this task; it aims at exploring and evaluating the TV interpreters’ linguistic choices and whether the original emotive effect was maintained, upgraded, downgraded or abandoned in their renditions. It also aims at exploring the possible difficulties and challenges that emerged during this process and might have influenced the interpreters’ linguistic choices. To achieve its aims, the study analysed Trump’s victory speech delivered on November 6, 2016, along with four Arabic simultaneous interpretations produced by four TV channels: Al-Jazeera, RT, CBC News, and France 24. The analysis of the study relied on two frameworks: a macro and a micro framework. The former presents an overview of the wider context of the English speech as well as an overview of the speaker and his political background to help understand the linguistic choices he made in the speech, and the latter framework investigates the linguistic tools which were employed by the speaker to stir people’s emotions. These tools were investigated based on Shamaa’s (1978) classification of emotive meaning according to their linguistic level: phonological, morphological, syntactic, and semantic and lexical levels. Moreover, this level investigates the patterns of rendition which were detected in the Arabic deliveries. The results of the study identified different rendition patterns in the Arabic deliveries, including parallel rendition, approximation, condensation, elaboration, transformation, expansion, generalisation, explicitation, paraphrase, and omission. The emerging patterns, as suggested by the analysis, were influenced by factors such as speedy and continuous delivery of some stretches, and highly-dense segments among other factors. The study aims to contribute to a better understanding of TV simultaneous interpreting between English and Arabic, as well as the practices of TV interpreters when rendering emotiveness especially that little is known about interpreting practices in the field of TV, particularly between Arabic and English.

Keywords: emotive overtones, interpreting strategies, political speeches, TV interpreting

Procedia PDF Downloads 159

Authors: S. Arabnejad, D. W. C. Cheong, H. Chaobin, V. P. W. Shim

Abstract:

Debonding is the one of the fundamental damage mechanisms in particle field composites. This phenomenon gains more importance in nano composites because of the extensive interfacial region present in these materials. Understanding the debonding mechanism accurately, can help in understanding and predicting the response of nano composites as the interface deteriorates. The small length scale of the phenomenon makes the experimental characterization complicated and the results of it, far from real physical behavior. In this study the damage process in nylon-6/silica interface is examined through Molecular Dynamics (MD) modeling and simulations. The silica has been modeled with three forms of surfaces – without any surface treatment, with the surface treatment of 3-aminopropyltriethoxysilane (APTES) and with Hexamethyldisilazane (HMDZ) surface treatment. The APTES surface modification used to create functional groups on the silica surface, reacts and form covalent bonds with nylon 6 chains while the HMDZ surface treatment only interacts with both particle and polymer by non-bond interaction. The MD model in this study uses a PCFF force field. The atomic model is generated in a periodic box with a layer of vacuum on top of the polymer layer. This layer of vacuum is large enough that assures us from not having any interaction between particle and substrate after debonding. Results show that each of these three models show a different traction separation behavior. However, all of them show an almost bilinear traction separation behavior. The study also reveals a strong correlation between the length of APTES surface treatment and the cohesive strength of the interface.

Keywords: debonding, surface treatment, cohesive response, separation behaviour

Procedia PDF Downloads 460

Authors: Qing Cao, Fei Wang, Yu-Qiang Wang, Li-Ya Huang, Tian-Tian Sang, Shu-Yan Chen

Abstract:

Aims: TNF Receptor-Associated Factor 6 (TRAF6) acts as a multifunctional regulator of the Transforming Growth Factor (TGF)-β signaling pathway, and mediates Smad-independent JNK and p38 activation via TGF-β. This study was performed to test the hypothesis that TGF-β/TRAF6 is essential for angiotensin-II (Ang II)-induced differentiation of rat c-kit+ Cardiac Stem Cells (CSCs). Methods and Results: c-kit+ CSCs were isolated from neonatal Sprague Dawley (SD) rats, and their c-kit status was confirmed with immunofluorescence staining. A TGF-β type I receptor inhibitor (SB431542) or the small interfering RNA (siRNA)-mediated knockdown of TRAF6 were used to investigate the role of TRAF6 in TGF-β signaling. Rescue of TRAF6 siRNA transfected cells with a 3'UTR deleted siRNA insensitive construct was conducted to rule out the off target effects of the siRNA. TRAF6 dominant negative (TRAF6DN) vector was constructed and used to infect c-kit+ CSCs, and western blotting was used to assess the expression of TRAF6, JNK, p38, cardiac-specific proteins, and Wnt signaling proteins. Physical interactions between TRAF6 and TGFβ receptors were studied by coimmunoprecipitation. Cardiac differentiation was suppressed in the absence of TRAF6. Forced expression of TRAF6 enhanced the expression of TGF-β-activated kinase1 (TAK1), and inhibited Wnt signaling. Furthermore, TRAF6 increased the expression of cardiac-specific proteins (cTnT and Cx-43) but inhibited the expression of Wnt3a. Conclusions: Our data suggest that TRAF6 plays an important role in Ang II induced differentiation of c-kit+ CSCs via the non-canonical signaling pathway.

Keywords: cardiac stem cells, differentiation, TGF-β, TRAF6, ubiquitination, Wnt

Procedia PDF Downloads 401

Authors: Trung Le Thanh

Abstract:

Bored piles are always the optimal solution for high-rise building foundations. They have many advantages, such as large diameter, large pile length and construction in all different geological conditions. However, due to construction characteristics, the load-bearing capacity of bored piles is not optimal because wall friction is reduced due to poor contact between the pile and the surrounding soil. Therefore, grouting technology along the pile body helps improve the load-bearing capacity of bored piles significantly through increasing the skin resistance of the pile and surrounding soil. The improvement of pile skin resistance depends on the parameters of grouting technology, especially grouting volume, mortar viscosity, mortar strength,... and different geological conditions. Studies show that the technology of grouting piles on sandy soil is more effective than on clay. This article presents an experimental model to determine the load-bearing capacity of bored piles with a diameter of 400 mm and a length of 3 m on sand with different slurry volume in Tan Uyen city, Binh Duong province. On that basis, analyze the correlation between the increase in load-bearing capacity of bored piles without and with shaft grouting pile. Research results show that the wall resistance of shaft grouted piles increases 2-3 times compared to piles without grouting, and the pile's load-bearing capacity increases significantly. The article's research provides scientific value for consulting work on the design of bored piles when grouted along the pile body.

Keywords: bored pile, shaft grouting, bearing capacity, pile shaft resistance

Procedia PDF Downloads 65

Authors: Douglas J. Kube

Abstract:

At the beginning of the COVID-19 pandemic, the Canadian Red Cross deployed workers into long-term care homes across Canada to support our most vulnerable citizens. It began by recruiting and training small teams of workers to provide non-clinical services for facilities in outbreak. Deployed workers were trained on an approach based on successful Red Cross deployments used with Ebola in which zones were established, levels of protection used, and strict protocols followed to prevent exposure. This paper addresses aspects of human performance through a safety culture lens. The Red Cross deployments highlight valuable insights and are an excellent case study in the principles of human performance and organizational culture. This paper looks at human performance principles, including human fallibility, predictability of error-likely situations, avoiding events by understanding reasons mistakes occur, and the influence on behaviour by organizational factors. This study demonstrates how the Red Cross’s organizational culture and work design positively influenced performance to protect workers and residents/clients. Lastly, this paper shares lessons that can be applied in many workplaces to improve worker health and safety and safety culture. This critical examination is based on the author’s experience as a Senior Occupational Health and Safety Advisor with the Red Cross during the pandemic as part of the team responsible for developing and implementing biological safety practices in long-term care deployments.

Keywords: COVID, human performance, organizational culture, work design

Procedia PDF Downloads 58

Authors: Nourmalita Safitri Ningsih, Ridwan, Iqri Puspa Yunanda

Abstract:

The aim of this study was to utilize the waste from slaughterhouses for chicken feed ingredients is probiotic. Livestock waste produced by livestock activities such as feces, urine, food remains, as well as water from livestock and cage cleaning. The process starts with the isolation of bacteria. Rumen fluid is taken at Slaughterhouse Giwangan, Yogyakarta. Isolation of Lactobacillus ruminus is done by using de Mann Rogosa Sharpe (MRS) medium. In the sample showed a rod-shaped bacteria are streaked onto an agar plates. After it was incubated at 37ºC for 48 hours, after which it is observed. The observation of these lactic acid bacteria it will show a clear zone at about the colony. These bacterial colonies are white, round, small, shiny on the agar plate mikroenkapsul In the manufacturing process carried out by the method of freeze dried using skim milk in addition capsulated material. Then the results of these capsulated bacteria are mixed with feed for livestock. The results from the mixing of capsulated bacteria in feed are to increase the quality of animal feed so as to provide a good effect on livestock. Scanning electron microscope testing we have done show the results of bacteria have been shrouded in skim milk. It can protect the bacteria so it is more durable in use. The observation of the bacteria showed a sheath on Lactobacillus sp. Preservation of bacteria in this way makes the bacteria more durable for use. As well as skim milk can protect bacteria that are resistant to the outside environment. Results of probiotics in chicken feed showed significant weight gain in chickens. Calculation Anova (P <0.005) shows the average chicken given probiotics her weight increased.

Keywords: chicken, probiotics, waste, Lactobacillus sp, bacteria

Procedia PDF Downloads 319

Authors: Novie Nuraini, Sari Hanifa, Yetty Ramli

Abstract:

Chronic subdural hematoma (cSDH) is a common condition after head trauma. Although the size of the thickness of cSDH has an important role in the decision to perform surgery, but the size limit of the thickness is not absolute. In this serial case report, we evaluate three case report of cSDH that indicated to get the surgical procedure because of deficit neurologic and neuroimaging finding with subfalcine herniation more than 0.5 cm and hematoma thickness more than one cm. On the first case, the patient got evacuation hematoma procedure, but the second and third case, we did nonsurgical treatment because the patient and family refused to do the operation. We did the conservative treatment with bed rest and mannitol. Serial radiologic evaluation is done when we found worsening condition. We also reevaluated radiologic examination two weeks after the treatment. The results in this serial case report, the first and second case have a good outcome. On the third case, there was a worsening condition, which in this patient there was a comorbid with type two diabetic mellitus, pneumonie and chronic kidney disease. Some conservative treatment such as bed rest, corticosteroid, mannitol or the other hyperosmolar has a good outcome in patient without neurologic deficits, small hematoma, and or patient without comorbid disease. Evacuate hematome is the best choice in cSDH treatment with deficit neurologic finding. Afterall, there is some condition that we can not do the surgical procedure. Serial radiologic examination needed after two weeks to evaluate the treatment or if there is any worsening condition.

Keywords: chronic subdural hematoma, traumatic brain injury, surgical treatment, nonsurgical treatment, outcome

Procedia PDF Downloads 332

Authors: Claudia Cedeno Nadal, Mei-Ling Villafana, Griela Rodriguez, Jessica Martin, Jennifer Martin, Megan Patel

Abstract:

This study systematically examines the impact of Transcendental Mindfulness Meditation on anxiety symptoms in young females aged 18-25. Through a comprehensive literature review, we found consistent evidence supporting the positive influence of Transcendental Mindfulness Meditation on reducing anxiety, enhancing overall well-being, and decreasing perceived stress levels within this demographic. The mechanisms underlying these effects include heightened self-awareness, improved emotional regulation, and the development of effective stress-coping strategies. These findings have significant implications for mental health interventions targeting young females. However, the reviewed studies had some limitations, such as small sample sizes and reliance on self-report measures. To advance this field, future research should focus on larger sample sizes and utilize a broader range of measurement methods, including neuroscience assessments. Additionally, investigating the temporal relationships between Transcendental Mindfulness Meditation, proposed mediators, and anxiety symptoms will help establish causal specificity and a deeper understanding of the precise mechanisms of action. The development of integrative models based on these mechanisms can further enhance the effectiveness of Transcendental Mindfulness Meditation as an intervention for anxiety in this demographic. This study contributes to the current knowledge on the potential benefits of Transcendental Mindfulness Meditation for reducing anxiety in young females, paving the way for more targeted and effective mental health interventions in this population.

Keywords: mindfulness, meditation, anxiety, transcendental mindfulness

Procedia PDF Downloads 70

Authors: Sharda Nara, Bansi Dhar Malhotra

Abstract:

Investigation of the vitamins as an electron transfer mediator could significantly assist in merging the area of tissue engineering and electronics required for the implantable therapeutic devices. The present study report that the molecules of folic acid released by Providencia rettgeri via fermentation route under the anoxic condition of the microbial fuel cell (MFC) exhibit characteristic electrochemical and optical properties, as indicated by absorption spectroscopy, photoluminescence (PL), and cyclic voltammetry studies. The absorption spectroscopy has depicted an absorption peak at 263 nm with a small bulge around 293 nm on day two of bacterial culture, whereas an additional peak was observed at 365 nm on the twentieth day. Furthermore, the PL spectra has indicated that the maximum emission occurred at various wavelengths 420, 425, 440, and 445 nm when excited by 310, 325, 350, and 365 nm. The change of emission spectra with varying excitation wavelength might be indicating the presence of tunable optical bands in the folic acid molecules co-related with the redox activity of the molecules. The results of cyclic voltammetry studies revealed that the oxidation and reduction occurred at 0.25V and 0.12V, respectively, indicating the electrochemical behavior of the folic acid. This could be inferred that the released folic acid molecules in a MFC might undergo inter as well as intra molecular electron transfer forming different intermediate states while transferring electrons to the electrode surface. Synchronization of electrochemical and optical properties of folic acid molecules could be potentially promising for the designing of electroactive scaffold and biocompatible conductive surface for the applications of tissue engineering and biofuel cells, respectively.

Keywords: biofuel cell, electroactivity, folic acid, tissue engineering

Procedia PDF Downloads 131

Authors: Tugba Metinyurt

Abstract:

Microaggressions are small, everyday verbal and behavioral slights that communicate derogatory messages to individuals on the basis of their group membership. They are often unintentional and not intended to do harm, and yet research has shown that their cumulative effect can be quite detrimental. The current pilot study focuses on the role of bystanders disrupting gender microaggressions and potential barriers of challenging them in the academic workplace at University of Massachusetts Lowell (UML). The participants in this study included 9 male and 20 female from faculty of different disciplines at UML. A Barriers to Intervening Questionnaire asks respondents 1) to rate barriers to intervening in situations described in three short vignettes and 2) to identify more general factors that make it more or less likely that UML faculty will intervene in microaggressions as bystanders through response to an open-ended question. Responses to the questionnaire scales that ask about respondents’ own reactions to the vignettes indicated that faculty may hesitate to interrupt gender microaggressions to avoid being perceived as offensive, losing their relationship with their coworkers, and engaging possible arguments. Responses to the open-ended question, which asked more generally about perceived barriers, revealed a few additional barriers; lack of interpersonal and institutional support, repercussion to self, personal orientation/personality, and privilege. Interestingly, participants tended to describe the obstacles presented in the questionnaire as unlikely to prevent them from intervening, yet the same barriers were suggested to be issues for others on the open-ended questions. Limitations and future directions are discussed. The barriers identified in this research can inform efforts to create bystander trainings to interrupt microaggressions in the academic workplaces.

Keywords: academic workplace, bystander behavior, implicit bias, microaggressions

Procedia PDF Downloads 151

Authors: Armin Solemanifar, Arthur Wilkinson, Kinjalkumar Patel

Abstract:

Carbon fibre (CF) - polymer laminate composites have very low densities (approximately 40% lower than aluminium), high strength and high stiffness but in terms of toughness properties they often require modifications. For example, adding rubbers or thermoplastics toughening agents are common ways of improving the interlaminar fracture toughness of initially brittle thermoset composite matrices. The main aim of this project was to toughen CF-epoxy resin laminate composites using hybrid CF-fabrics incorporating Innegra™ a commercial highly-oriented polypropylene (PP) fibre, in which more than 90% of its crystal orientation is parallel to the fibre axis. In this study, the damage tolerance of hybrid (carbon-Innegra, CI) composites was investigated. Laminate composites were produced by resin-infusion using: pure CF fabric; fabrics with different ratios of commingled CI, and two different types of pure Innegra fabrics (Innegra 1 and Innegra 2). Dynamic mechanical thermal analysis (DMTA) was used to measure the glass transition temperature (Tg) of the composite matrix and values of flexural storage modulus versus temperature. Mechanical testing included drop-weight impact, compression-after-impact (CAI), and interlaminar (short-beam) shear strength (ILSS). Ultrasonic C-Scan imaging was used to determine the impact damage area and scanning electron microscopy (SEM) to observe the fracture mechanisms that occur during failure of the composites. For all composites, 8 layers of fabrics were used with a quasi-isotropic sequence of [-45°, 0°, +45°, 90°]s. DMTA showed the Tg of all composites to be approximately same (123 ±3°C) and that flexural storage modulus (before the onset of Tg) was the highest for the pure CF composite while the lowest were for the Innegra 1 and 2 composites. Short-beam shear strength of the commingled composites was higher than other composites, while for Innegra 1 and 2 composites only inelastic deformation failure was observed during the short-beam test. During impact, the Innegra 1 composite withstood up to 40 J without any perforation while for the CF perforation occurred at 10 J. The rate of reduction in compression strength upon increasing the impact energy was lowest for the Innegra 1 and 2 composites, while CF showed the highest rate. On the other hand, the compressive strength of the CF composite was highest of all the composites at all impacted energy levels. The predominant failure modes for Innegra composites observed in cross-sections of fractured specimens were fibre pull-out, micro-buckling, and fibre plastic deformation; while fibre breakage and matrix delamination were a major failure observed in the commingled composites due to the more brittle behaviour of CF. Thus, Innegra fibres toughened the CF composites but only at the expense of reducing compressive strength.

Keywords: hybrid composite, thermoplastic fibre, compression strength, damage tolerance

Procedia PDF Downloads 295

Authors: Neeraj Kumar, J. P. Narayan

Abstract:

The effects of multiple Structure-Soil-Structure Interactions (SSSI) on the seismic wave-field is generally disregarded by earthquake engineers, particularly the surface waves which cause more damage to buildings. Closely built high rise buildings exchange substantial seismic energy with each other and act as a full-coupled dynamic system. In this paper, SSI effects on the building responses and the free field motion due to a small city consisting 25- homogenous buildings blocks of 10-storey are quantified. The rocking and translational behavior of building under Rayleigh wave loading is studied for different dimensions of the building. The obtained dynamic parameters of buildings revealed a reduction in building roof drift with an increase in number of buildings ahead of the considered building. The strain developed by vertical component of Rayleigh may cause tension in structural components of building. A matching of fundamental frequency of building for the horizontal component of Rayleigh wave with that for vertically incident SV-wave is obtained. Further, the fundamental frequency of building for the vertical vibration is approximately twice to that for horizontal vibration. The city insulation has caused a reduction of amplitude of Rayleigh wave up to 19.3% and 21.6% in the horizontal and vertical components, respectively just outside the city. Further, the insulating effect of city was very large at fundamental frequency of buildings for both the horizontal and vertical components. Therefore, it is recommended to consider the insulating effects of city falling in the path of Rayleigh wave propagation in seismic hazard assessment for an area.

Keywords: structure-soil-structure interactions, Rayleigh wave propagation, finite difference simulation, dynamic response of buildings

Procedia PDF Downloads 215

Authors: Orod Zarrin, Mohesn Ramezan Shirazi, Hassan Moniri

Abstract:

The use of pile foundations technique is developed to support structures and buildings on soft soil. The most important dynamic load that can affect the pile structure is earthquake vibrations. Pile foundations during earthquake excitation indicate that piles are subject to damage by affecting the superstructure integrity and serviceability. During an earthquake, two types of stresses can damage the pile head, inertial load that is caused by superstructure and deformation which caused by the surrounding soil. Soil deformation and inertial load are associated with the acceleration developed in an earthquake. The acceleration amplitude at the ground surface depends on the magnitude of earthquakes, soil properties and seismic source distance. According to the investigation, the damage is between the liquefiable and non-liquefiable layers and also soft and stiff layers. This damage crushes the pile head by increasing the inertial load which is applied by the superstructure. On the other hand, the cracks on the piles due to the surrounding soil are directly related to the soil profile and causes cracks from small to large. However, the large cracks reason have been listed such as liquefaction, lateral spreading, and inertial load. In the field of designing, elastic response of piles is always a challenge for designer in liquefaction soil, by allowing deflection at top of piles. Moreover, absence of plastic hinges in piles should be insured, because the damage in the piles is not observed directly. In this study, the performance and behavior of pile foundations during liquefaction and lateral spreading are investigated. In addition, emphasize on the soil behavior in the liquefiable and non-liquefiable layers by different aspect of piles damage such as ranking, location and degree of damage are going to discuss.

Keywords: pile, earthquake, liquefaction, non-liquefiable, damage

Procedia PDF Downloads 301

Authors: Musa Ogah Ari

Abstract:

Poverty has engaged the attention of the global community. Both the rich and poor countries are concerned about its prevalence and impacts. This phenomenon is more pervasive among developing countries with the greater challenges manifesting among African countries. In Nigeria people live with very low income, and so decent three-square meals, clothes, shelter and other basic necessities are very difficult to come by for most of the population. Qualitative health facilities are seriously lacking to over 160 million population in the state. Equally lacking are educational and social infrastructures that can be available to the people at affordable rates. Roads linking the interior parts of the state are generally in deplorable conditions, particularly in the rainy season. Safe drinking water is hard to come by as the state is not properly placed and equipped to function in full capacity to serve the interest of the people. The challenges of poverty is definitely enormous for both the national and state governments consequently, debilitating scourge of poverty. As the ruling elites in Nigeria claim to reduce the rising profile of poverty through series of policies and programmes, food production, promotion and funding of co-operatives for agriculture, improvement of infrastructures at the rural areas to guaranteeing employment through skill acquisition, assistance of rural women to break away from poverty and the provision of small scale credit facilities to poor members of the public were abysmally low. It is observed that the poverty alleviation programmes and policies failed because they were by nature, character and implementation pro-elites and anti-masses. None of the programmes or policies engaged the rural poor either in terms of formulation or implementation.

Keywords: the state, poverty, government policies, strategies, social amenities, corruption

Procedia PDF Downloads 355

Authors: Zahra Khan

Abstract:

Surface-Enhanced Raman Spectroscopy (SERS) has received increased attention in recent years, focusing on biological and medical applications due to its great sensitivity as well as molecular specificity. In the context of biological samples, there are generally two methodologies for SERS based applications: label-free detection and the use of SERS tags. The necessity of tagging can make the process slower and limits the use for real life. Label-free detection offers the advantage that it reports direct spectroscopic evidence associated with the target molecule rather than the label. Reproducible, highly monodisperse gold nanoparticles (Au NPs) were synthesized using a relatively facile seed-mediated growth method. Different capping agents (TRIS, citrate, and CTAB) were used during synthesis, and characterization was performed. They were then mixed with different analyte solutions before drop-casting onto a glass slide prior to Raman measurements to see which NPs displayed the highest SERS activity as well as their stability. A host of different analytes were tested, both non-biomolecules and biomolecules, which were all successfully detected using this method at concentrations as low as 10-3M with salicylic acid reaching a detection limit in the nanomolar range. SERS was also performed on samples with a mixture of analytes present, whereby peaks from both target molecules were distinctly observed. This is a fast and effective rapid way of testing samples and offers potential applications in the biomedical field as a tool for diagnostic and treatment purposes.

Keywords: gold nanoparticles, label free, seed-mediated growth, SERS

Procedia PDF Downloads 125

Authors: Gregory E. Ofili

Abstract:

Introduction and Objective: Climate change and a global economy mean farmers must adapt and gain access to affordable and reliable automation technologies. Key barriers include a lack of transportation, electricity, and internet service, coupled with costly enabling technologies and limited local subject matter expertise. Methodology/Approach: Resourcefulness is essential to mechanization on a farm. This runs contrary to the tech industry practice of planned obsolescence and disposal. One solution is plug-and-play hardware that allows farmer to assemble, repair, program, and service their own fleet of industrial machines. To that end, we developed a method of manufacturing low-cost utility robots, transport vehicles, and solar/wind energy harvesting systems, all running on an open-source Robot Operating System (ROS). We demonstrate this technology by fabricating a utility robot and an all-terrain (4X4) utility vehicle. Constructed of aluminum trusses and weighing just 40 pounds, yet capable of transporting 200 pounds of cargo, on sale for less than $2,000. Conclusions & Policy Implications: Electricity, internet, and automation are essential for productivity and competitiveness. With planned obsolescence, the priorities of technology suppliers are not aligned with the farmer’s realities. This patent-pending method of manufacturing low-cost industrial robots and electric vehicles has met its objective. To create low-cost machines, the farmer can assemble, program, and repair with basic hand tools.

Keywords: automation, robotics, utility robot, small-hold farm, robot operating system

Procedia PDF Downloads 70

Authors: Veronika Lesáková, Silvia Slezáková, František Štěpánek

Abstract:

Drug dosage forms consisting of multi-unit particle systems (MUPS) for modified drug release provide a promising route for overcoming the limitation of conventional tablets. Despite the conventional use of pellets as units for MUP systems, 3D printed polymers loaded with a drug seem like an interesting candidate due to the control over dosing that 3D printing mechanisms offer. Further, 3D printing offers high flexibility and control over the spatial structuring of a printed object. The final MUPS tablets include PVP and HPC as granulate with other excipients, enabling the compaction process of this mixture with 3D printed inclusions, also termed minitablets. In this study, we have developed the multi-step production process for MUPS tablets, including the 3D printing technology. The MUPS tablets with incorporated 3D printed minitablets are a complex system for drug delivery, providing modified drug release. Such structured tablets promise to reduce drug fluctuations in blood, risk of local toxicity, and increase bioavailability, resulting in an improved therapeutic effect due to the fast transfer into the small intestine, where particles are evenly distributed. Drug loaded 3D printed minitablets were compacted into the excipient mixture, influencing drug release through varying parameters, such as minitablets size, matrix composition, and compaction parameters. Further, the mechanical properties and morphology of the final MUPS tablets were analyzed as many properties, such as plasticity and elasticity, can significantly influence the dissolution profile of the drug.

Keywords: 3D printing, dissolution kinetics, drug delivery, hot-melt extrusion

Procedia PDF Downloads 92

Authors: Shahin A. Abdel-Naby, Asad T. Hassan

Abstract:

Astrophysical plasma environments can be classified into collisionally ionized (CP) and photoionizedplasmas (PP). In the PP, ionization is caused by an external radiation field, while it is caused by electron collision in the CP. Accurate and reliable laboratory astrophysical data for electron-ion recombination is needed for plasma modeling for low and high-temperatures. Dielectronic recombination (DR) is the dominant recombination process for the CP for most of the ions. When a free electron is captured by an ion with simultaneous excitation of its core, a doubly-exited intermediate state may be formed. The doubly excited state relaxes either by electron emission (autoionization) or by radiative decay (photon emission). DR process takes place when the relaxation occurs to a bound state by a photon emission. DR calculations at low-temperatures are problematic and challenging since small uncertaintiesin the low-energy DR resonance positions can produce huge uncertainties in DR rate coefficients.DR rate coefficients for N²⁺ and O³⁺ ions are calculated using state-of-the-art multi-configurationBreit-Pauli atomic structure AUTOSTRUCTURE collisional package within the generalized collisional-radiative framework. Level-resolved calculations for RR and DR rate coefficients from the ground and metastable initial states are produced in an intermediate coupling scheme associated withn = 0 and n = 1 core-excitations. DR cross sections for these ions are convoluted with the experimental electron-cooler temperatures to produce DR rate coefficients. Good agreements are foundbetween these rate coefficients and theexperimental measurements performed at CRYRING heavy-ionstorage ring for both ions.

Keywords: atomic data, atomic process, electron-ion collision, plasmas

Procedia PDF Downloads 95

Authors: Chen Yuan, Nick Green, Stuart Blackburn

Abstract:

The investment casting process offers a great freedom of design combined with the economic advantage of near net shape manufacturing. It is widely used for the production of high value precision cast parts in particularly in the aerospace sector. Various combinations of materials have been used to produce the ceramic moulds, but most investment foundries use a silica based binder system in conjunction with fused silica, zircon, and alumino-silicate refractories as both filler and coarse stucco materials. However, in the context of advancing alloy technologies, silica based systems are struggling to keep pace, especially when net-shape casting titanium alloys. Study has shown that the casting of titanium based alloys presents considerable problems, including the extensive interactions between the metal and refractory, and the majority of metal-mould interaction is due to reduction of silica, present as binder and filler phases, by titanium in the molten state. Cleaner, more refractory systems are being devised to accommodate these changes. Although yttria has excellent chemical inertness to titanium alloy, it is not very practical in a production environment combining high material cost, short slurry life, and poor sintering properties. There needs to be a cost effective solution to these issues. With limited options for using pure oxides, in this work, a silica-free magnesia spinel MgAl₂O₄ was used as a primary coat filler and alumina as a binder material to produce facecoat in the investment casting mould. A comparison system was also studied with a fraction of the rare earth oxide Y₂O₃ adding into the filler to increase the inertness. The stability of the MgAl₂O₄/Al₂O₃ and MgAl₂O₄/Y₂O₃/Al₂O₃ slurries was assessed by tests, including pH, viscosity, zeta-potential and plate weight measurement, and mould properties such as friability were also measured. The interaction between the face coat and titanium alloy was studied by both a flash re-melting technique and a centrifugal investment casting method. The interaction products between metal and mould were characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS). The depth of the oxygen hardened layer was evaluated by micro hardness measurement. Results reveal that introducing a fraction of Y₂O₃ into magnesia spinel can significantly increase the slurry life and reduce the thickness of hardened layer during centrifugal casting.

Keywords: titanium alloy, mould, MgAl₂O₄, Y₂O₃, interaction, investment casting

Procedia PDF Downloads 113

Authors: Segun Steven Bodunde

Abstract:

Mudlogging is the continuous analysis of rock cuttings and drilling fluids to ascertain the presence or absence of oil and gas from the formation penetrated by the drilling bit. This research highlighted a case study of Well BSS-99ST from ‘Bisas Field’, Niger Delta, with depth extending from 1950m to 3640m (Measured Depth). It was focused on identifying the lithologies encountered at specified depth intervals and to accurately delineate the targeted potential reservoir on the field and prepare the lithology and Master log. Equipment such as the Microscope, Fluoroscope, spin drier, oven, and chemicals, which includes: hydrochloric acid, chloroethene, and phenolphthalein, were used to check the cuttings for their calcareous nature, for oil show and for the presence of Cement respectively. Gas analysis was done using the gas chromatograph and the Flame Ionization Detector, which was connected to the Total Hydrocarbon Analyzer (THA). Drilling Parameters and Gas concentration logs were used alongside the lithology log to predict and accurately delineate the targeted reservoir on the field. The result showed continuous intercalation of sand and shale, with the presence of small quantities of siltstone at a depth of 2300m. The lithology log was generated using Log Plot software. The targeted reservoir was identified between 3478m to 3510m after inspection of the gas analysis, lithology log, electric logs, and the drilling parameters. Total gas of about 345 units and five Alkane Gas components were identified in the specific depth range. A comparative check with the Gamma ray log from the well further confirmed the lithologic sequence and the accurate delineation of the targeted potential reservoir using mudlogging.

Keywords: mudlogging, chromatograph, drilling fluids, calcareous

Procedia PDF Downloads 150

Authors: M. Beusink, E. W. C. Coenen

Abstract:

The increased application of novel structural materials, such as high grade asphalt, concrete and laminated composites, has sparked the need for a better understanding of the often complex, non-linear mechanical behavior of such materials. The effective macroscopic mechanical response is generally dependent on the applied load path. Moreover, it is also significantly influenced by the microstructure of the material, e.g. embedded fibers, voids and/or grain morphology. At present, multiscale techniques are widely adopted to assess micro-macro interactions in a numerically efficient way. Computational homogenization techniques have been successfully applied over a wide range of engineering cases, e.g. cases involving first order and second order continua, thin shells and cohesive zone models. Most of these homogenization methods rely on Representative Volume Elements (RVE), which model the relevant microstructural details in a confined volume. Imposed through kinematical constraints or boundary conditions, a RVE can be subjected to a microscopic load sequence. This provides the RVE's effective stress-strain response, which can serve as constitutive input for macroscale analyses. Simultaneously, such a study of a RVE gives insight into fine scale phenomena such as microstructural damage and its evolution. It has been reported by several authors that the type of boundary conditions applied to the RVE affect the resulting homogenized stress-strain response. As a consequence, dedicated boundary conditions have been proposed to appropriately deal with this concern. For the specific case of a planar assumption for the analyzed structure, e.g. plane strain, axisymmetric or plane stress, this assumption needs to be addressed consistently in all considered scales. Although in many multiscale studies a planar condition has been employed, the related impact on the multiscale solution has not been explicitly investigated. This work therefore focuses on the influence of the planar assumption for multiscale modeling. In particular the plane stress case is highlighted, by proposing three different implementation strategies which are compatible with a first-order computational homogenization framework. The first method consists of applying classical plane stress theory at the microscale, whereas with the second method a generalized plane stress condition is assumed at the RVE level. For the third method, the plane stress condition is applied at the macroscale by requiring that the resulting macroscopic out-of-plane forces are equal to zero. These strategies are assessed through a numerical study of a thin walled structure and the resulting effective macroscale stress-strain response is compared. It is shown that there is a clear influence of the length scale at which the planar condition is applied.

Keywords: first-order computational homogenization, planar analysis, multiscale, microstrucutures

Procedia PDF Downloads 233

Authors: Julia Wong, Hua Beng Lim, Cheryl Ho, Gin Jen Gwee, Rachel Tay

Abstract:

In Singapore, a few hospitals and non-governmental social service agencies have been utilising animal-assisted therapy (AAT) in their practice in recent years, although the animals used (e.g., dogs, cats, and horses) and program modality may differ due to the different practice settings, client profiles, and intervention goals. This pilot study explores dog owners’ perceptions of AAT with a focus on examining the enablers and barriers towards volunteering with their dogs in AAT programs in Singapore. A qualitative, thematic analysis study was conducted using in-depth, semi-structured interviews with 16 dog owners. 3 of the dog owners had previous experience volunteering with their dogs serving elderly patients in a community hospital, while the rest of the dog owners had no previous experience volunteering with their dogs. The former group was recruited with the help of the hospital, while the latter group was recruited via word-of-mouth. Dog owners who had volunteering experiences in AAT program versus those who had none differed in their perceptions towards AAT. Dog owners who had volunteered with their dogs in an AAT program in a hospital felt that their volunteering experience were meaningful to patients and to themselves, as they were intrinsically motivated by the desire to serve the community. Those who had not volunteered were hesitant to volunteer with their dogs as they were not comfortable with strangers touching their dogs. They also felt that it would be a huge commitment in terms of time and money; most of them do not own a car as it is uneconomical, and pets are not allowed on Singapore’s public transport systems. This study is limited by its small sample size, and its findings are not generalisable. However, given that volunteers are an invaluable resource in healthcare settings, future studies can examine more stakeholders’ perceptions towards AAT.

Keywords: animal-assisted therapy, dog-assisted therapy, volunteers, complementary therapy

Procedia PDF Downloads 100

Authors: S. V. Kuznetsov, M. N. Mayakova, V. Yu. Proydakova, V. V. Pavlov, A. S. Nizamutdinov, O. A. Morozov, V. V. Voronov, P. P. Fedorov

Abstract:

Increase in the share of electricity received by conversion of solar energy results in the reduction of the industrial impact on the environment from the use of the hydrocarbon energy sources. One way to increase said share is to improve the efficiency of solar energy conversion in silicon-based solar panels. Such efficiency increase can be achieved by transferring energy from sunlight-insensitive areas of work of silicon solar panels to the area of their photoresistivity. To achieve this goal, a transition to new luminescent materials with the high quantum yield of luminescence is necessary. Improvement in the quantum yield can be achieved by quantum cutting, which allows obtaining a quantum yield of down conversion of more than 150% due to the splitting of high-energy photons of the UV spectral range into lower-energy photons of the visible and near infrared spectral ranges. The goal of present work is to test approach of excitation through sensibilization of 4f-4f fluorescence of Yb3+ by various RE ions absorbing in UV and Vis spectral ranges. One of promising materials for quantum cutting luminophores are fluorides. In our investigation we have developed synthesis of nano- and submicron powders of calcium fluoride and strontium doped with rare-earth elements (Yb: Ce, Yb: Pr, Yb: Eu) of controlled dimensions and shape by co-precipitation from water solution technique. We have used Ca(NO3)2*4H2O, Sr(NO3)2, HF, NH4F as precursors. After initial solutions of nitrates were prepared they have been mixed with fluorine containing solution by dropwise manner. According to XRD data, the synthesis resulted in single phase samples with fluorite structure. By means of SEM measurements, we have confirmed spherical morphology and have determined sizes of particles (50-100 nm after synthesis and 150-300 nm after calcination). Temperature of calcination appeared to be 600°C. We have investigated the spectral-kinetic characteristics of above mentioned compounds. Here the diffuse reflection and laser induced fluorescence spectra of Yb3+ ions excited at around 4f-4f and 4f-5d transitions of Pr3+, Eu3+ and Ce3+ ions in the synthesized powders are reported. The investigation of down conversion luminescence capability of synthesized compounds included measurements of fluorescence decays and quantum yield of 2F5/2-2F7/2 fluorescence of Yb3+ ions as function of Yb3+ and sensitizer contents. An optimal chemical composition of CaF2-YbF3- LnF3 (Ln=Ce, Eu, Pr), SrF2-YbF3-LnF3 (Ln=Ce, Eu, Pr) micro- and nano- powders according to criteria of maximal IR fluorescence yield is proposed. We suppose that investigated materials are prospective in solar panels improvement applications. Work was supported by Russian Science Foundation grant #17-73- 20352.

Keywords: solar cell, fluorides, down-conversion luminescence, maximum quantum yield

Procedia PDF Downloads 272

Authors: Salam Kodsi

Abstract:

In this research, we sought to focus on constructive play and examine its components in the context of two different educational approaches: Waldorf and normative schools. When they are free to choose, construction is one of the forms of play most favored by children. Its short-term and long-term cognitive contributions are apparent in various areas of development. The lack of empirical studies about play in Waldorf schools, which addresses the possibility of this incidental learning inspired the need to enrich the body of existing knowledge. 90 children (4-6 yrs.old) four preschools ( two normative, two Waldorf) participated in a small homogeneous city. Naturalistic observations documented the time frame, physical space, and construction materials related to the freeform building; processes of construction among focal representative children and its products. The study’s main finding with respect to the construction output points to a connection between educational approach and level of construction sophistication. Higher levels of sophistication were found at the Waldorf preschools than at the mainstream preschools. This finding emerged due to the differences in the level of sophistication among the older children in the two types of preschools, while practically no differences emerged among the younger children. Discussion of the research findings considered the differences between the play environments in terms of time, physical space, and construction materials. The construction processes were characterized according to the design model stages. The construction output was characterized according to the sophistication scale dimensions and the connections between approach, age and gender, and sophistication level.

Keywords: constructive play, preschool, design process model, complexity

Procedia PDF Downloads 118

Authors: Andre F. A. Cyrino

Abstract:

Knowing that the technological advance is the focus on the efficient extraction of energy from wind, and therefore in the design of wind turbine structures, this work aims the study of the fluid-structure interaction of an idealized wind turbine. The blade was studied as a beam attached to a cylindrical Hub with rotation axis pointing the air flow that passes through the rotor. Using the calculus of variations and the finite difference method the blade will be simulated by a discrete number of nodes and the aerodynamic forces were evaluated. The study presented here was written on Matlab and performs a numeric simulation of a simplified model of windmill containing a Hub and three blades modeled as Euler-Bernoulli beams for small strains and under the constant and uniform wind. The mathematical approach is done by Hamilton’s Extended Principle with the aerodynamic loads applied on the nodes considering the local relative wind speed, angle of attack and aerodynamic lift and drag coefficients. Due to the wide range of angles of attack, a wind turbine blade operates, the airfoil used on the model was NREL SERI S809 which allowed obtaining equations for Cl and Cd as functions of the angle of attack, based on a NASA study. Tridimensional flow effects were no taken in part, as well as torsion of the beam, which only bends. The results showed the dynamic response of the system in terms of displacement and rotational speed as the turbine reached the final speed. Although the results were not compared to real windmills or more complete models, the resulting values were consistent with the size of the system and wind speed.

Keywords: blade aerodynamics, fluid–structure interaction, wind turbine aerodynamics, wind turbine blade

Procedia PDF Downloads 268