Search results for: home energy management system (HEMS)
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 30442

Search results for: home energy management system (HEMS)

15862 Meticulous Doxorubicin Release from pH-Responsive Nanoparticles Entrapped within an Injectable Thermoresponsive Depot

Authors: Huayang Yu, Nicola Ingram, David C. Green, Paul D. Thornton

Abstract:

The dual stimuli-controlled release of doxorubicin from gel-embedded nanoparticles is reported. Non-cytotoxic polymer nanoparticles are formed from poly(ethylene glycol)-b-poly(benzyl glutamate) that, uniquely, contain a central ester link. This connection renders the nanoparticles pH-responsive, enabling extensive doxorubicin release in acidic solutions (pH 6.5), but not in solutions of physiological pH (pH 7.4). Doxorubicin loaded nanoparticles were found to be stable for at least 31 days and lethal against the three breast cancer cell lines tested. Furthermore, doxorubicin-loaded nanoparticles could be incorporated within a thermoresponsive poly(2-hydroxypropyl methacrylate) gel depot, which forms immediately upon injection of poly(2-hydroxypropyl methacrylate) into aqueous solution. The combination of the poly(2-hydroxypropyl methacrylate) gel and poly(ethylene glycol)-b-poly(benzyl glutamate) nanoparticles yields an injectable doxorubicin delivery system that facilities near-complete drug release when maintained at elevated temperatures (37 °C) in acidic solution (pH 6.5). In contrast, negligible payload release occurs when the material is stored at room temperature in a non-acidic solution (pH 7.4). The system has great potential as a vehicle for the prolonged, site-specific release of chemotherapeutics.

Keywords: biodegradable, nanoparticle, polymer, thermoresponsive

Procedia PDF Downloads 131
15861 Everolimus Loaded Polyvinyl Alcohol Microspheres for Sustained Drug Delivery in the Treatment of Subependymal Giant Cell Astrocytoma

Authors: Lynn Louis, Bor Shin Chee, Marion McAfee, Michael Nugent

Abstract:

This article aims to develop a sustained release formulation of microspheres containing the mTOR inhibitor Everolimus (EVR) using Polyvinyl alcohol (PVA) to enhance the bioavailability of the drug and to overcome poor solubility characteristics of Everolimus. This paper builds on recent work in the manufacture of microspheres using the sessile droplet technique by freezing the polymer-drug solution by suspending the droplets into pre-cooled ethanol vials immersed in liquid nitrogen. The spheres were subjected to 6 freezing cycles and 3 freezing cycles with thawing to obtain proper geometry, prevent aggregation, and achieve physical cross-linking. The prepared microspheres were characterised for surface morphology by SEM, where a 3-D porous structure was observed. The in vitro release studies showed a 62.17% release over 12.5 days, indicating a sustained release due to good encapsulation. This result is comparatively much more than the 49.06% release achieved within 4 hours from the solvent cast Everolimus film as a control with no freeze-thaw cycles performed. The solvent cast films were made in this work for comparison. A prolonged release of Everolimus using a polymer-based drug delivery system is essential to reach optimal therapeutic concentrations in treating SEGA tumours without systemic exposure. These results suggest that the combination of PVA and Everolimus via a rheological synergism enhanced the bioavailability of the hydrophobic drug Everolimus. Physical-chemical characterisation using DSC and FTIR analysis showed compatibility of the drug with the polymer, and the stability of the drug was maintained owing to the high molecular weight of the PVA. The obtained results indicate that the developed PVA/EVR microsphere is highly suitable as a potential drug delivery system with improved bioavailability in treating Subependymal Giant cell astrocytoma (SEGA).

Keywords: drug delivery system, everolimus, freeze-thaw cycles, polyvinyl alcohol

Procedia PDF Downloads 116
15860 Study of Two MPPTs for Photovoltaic Systems Using Controllers Based in Fuzzy Logic and Sliding Mode

Authors: N. Ould cherchali, M. S. Boucherit, L. Barazane, A. Morsli

Abstract:

Photovoltaic power is widely used to supply isolated or unpopulated areas (lighting, pumping, etc.). Great advantage is that this source is inexhaustible, it offers great safety in use and it is clean. But the dynamic models used to describe a photovoltaic system are complicated and nonlinear and due to nonlinear I-V and P–V characteristics of photovoltaic generators, a maximum power point tracking technique (MPPT) is required to maximize the output power. In this paper, two online techniques of maximum power point tracking using robust controller for photovoltaic systems are proposed, the first technique use fuzzy logic controller (FLC) and the second use sliding mode controller (SMC) for photovoltaic systems. The two maximum power point tracking controllers receive the partial derivative of power as inputs, and the output is the duty cycle corresponding to maximum power. A Photovoltaic generator with Boost converter is developed using MATLAB/Simulink to verify the preferences of the proposed techniques. SMC technique provides a good tracking speed in fast changing irradiation and when the irradiation changes slowly or is constant the panel power of FLC technique presents a much smoother signal with less fluctuations.

Keywords: fuzzy logic controller, maximum power point, photovoltaic system, tracker, sliding mode controller

Procedia PDF Downloads 536
15859 Analyzing Restrictive Refugee Policies in Japan and the United Kingdom: An Examination of Fundamental Causes and Implications

Authors: Shalini Shawari Matharage

Abstract:

The worldwide refugee challenge has arisen as a critical concern, with millions of individuals fleeing their home countries owing to conflict, persecution, and human rights violations. Since the establishment of an international framework in 1951 for tackling the humanitarian needs of refugees and asylum seekers, many developed and developing countries have adopted a refugee admittance framework into their national immigration policy and steadily changed their domestic legislation to assist the resettlement of refugees. However, many developed nations have put forth strict limitations on refugee admission in the midst of the continuing refugee crisis, claiming factors including national sovereignty, security of their borders, and national economy. Two such developed nations that have been restrictive on refugees is Japan and the United Kingdom. Despite their contrasting histories, migration methods, and viewpoints on diversity in modern society, the two notably developed nations have taken similar restrictive approaches in refugee policy in the recent years. This study attempts to investigate the underlying causes that led these countries to adopt strict refugee policies and how those policies have affected their compliance with international human rights responsibilities. The study employs a head-to-head methodology to examine the structural inequities in Japan and the United Kingdom's refugee policies. Using data from the UNHCR Refugee Data Finder, official government policy proposals, statements, and academic works, the study evaluates the contemporary refugee legislations, fundamental causes, and subsequent implications. The study illustrates a combination of economic, security, and demographic issues, as well as political rigidity and negative public perceptions, as major determinants of the two countries' restrictive refugee policies. The findings shed light on the restrictive actions taken by Japan and the UK, raising concerns about potential breaches in obligations to their commitments to international law and human rights obligations. Understanding the underlying issues influencing these policies allows lawmakers and activists to establish more compassionate refugee policies that adhere to international human rights and protect vulnerable individuals fleeing persecution. Ultimately, this study aims to contribute to the development of sensible refugee policies that uphold human rights and humanitarian values.

Keywords: immigration, Japan, refugee policy, united kingdom

Procedia PDF Downloads 66
15858 Application of Ground Penetrating Radar and Light Falling Weight Deflectometer in Ballast Quality Assessment

Authors: S. Cafiso, B. Capace, A. Di Graziano, C. D’Agostino

Abstract:

Systematic monitoring of the trackbed is necessary to assure safety and quality of service in the railway system. Moreover, to produce effective management of the maintenance treatments, the assessment of bearing capacity of the railway trackbed must include ballast, sub-ballast and subgrade layers at different depths. Consequently, there is an increasing interest in obtaining a consistent measure of ballast bearing capacity with no destructive tests (NDTs) able to work in the physical and time restrictions of railway tracks in operation. Moreover, in the case of the local railway with reduced gauge, the use of the traditional high-speed track monitoring systems is not feasible. In that framework, this paper presents results from in site investigation carried out on ballast and sleepers with Ground Penetrating Radar (GPR) and Light Falling Weight Deflectometer (LWD). These equipment are currently used in road pavement maintenance where they have shown their reliability and effectiveness. Application of such Non-Destructive Tests in railway maintenance is promising but in the early stage of the investigation. More specifically, LWD was used to estimate the stiffness of ballast and sleeper support, as well. LWD, despite the limited load (6 kN in the trial test) applied directly on the sleeper, was able to detect defects in the bearing capacity at the Sleeper/Ballast interface. A dual frequency GPR was applied to detect the presence of layers’ discontinuities at different depths due to fouling phenomena that are the main causes of changing in the layer dielectric proprieties within the ballast thickness. The frequency of 2000Mhz provided high-resolution data to approximately 0.4m depth, while frequency of 600Mhz showed greater depth penetration up to 1.5 m. In the paper literature review and trial in site experience are used to identify Strengths, Weaknesses, Opportunities, and Threats (SWOT analysis) of the application of GPR and LWD for the assessment of bearing capacity of railway track-bed.

Keywords: bearing capacity, GPR, LWD, no destructive test, railway track

Procedia PDF Downloads 124
15857 Development of Colorimetric Based Microfluidic Platform for Quantification of Fluid Contaminants

Authors: Sangeeta Palekar, Mahima Rana, Jayu Kalambe

Abstract:

In this paper, a microfluidic-based platform for the quantification of contaminants in the water is proposed. The proposed system uses microfluidic channels with an embedded environment for contaminants detection in water. Microfluidics-based platforms present an evident stage of innovation for fluid analysis, with different applications advancing minimal efforts and simplicity of fabrication. Polydimethylsiloxane (PDMS)-based microfluidics channel is fabricated using a soft lithography technique. Vertical and horizontal connections for fluid dispensing with the microfluidic channel are explored. The principle of colorimetry, which incorporates the use of Griess reagent for the detection of nitrite, has been adopted. Nitrite has high water solubility and water retention, due to which it has a greater potential to stay in groundwater, endangering aquatic life along with human health, hence taken as a case study in this work. The developed platform also compares the detection methodology, containing photodetectors for measuring absorbance and image sensors for measuring color change for quantification of contaminants like nitrite in water. The utilization of image processing techniques offers the advantage of operational flexibility, as the same system can be used to identify other contaminants present in water by introducing minor software changes.

Keywords: colorimetric, fluid contaminants, nitrite detection, microfluidics

Procedia PDF Downloads 192
15856 Possibilities of Building Regional Migration Governance due to the Venezuelan Diaspora in Ibero-America (2015-2018)

Authors: Jonathan Palatz Cedeño

Abstract:

The paper will seek to examine the scope and limitations of the process of construction of ordinary and extraordinary migration regulatory tools of the countries of Latin America, due to the Venezuelan diaspora in Ibero-America (2015-2018). The analysis methodology will be based on a systematic presentation of the existing advances in the subject under a qualitative approach, in which the results are detailed. We hold that an important part of the Latin American countries that used to be the emitters of migrants have had to generate, with greater or lesser success both nationally and regionally, ordinary and extraordinary migration regulatory tools to respond to the rapid intensification of the current Venezuelan migratory flows. This fact beyond implementing policies for the reception and integration of this population marks a new moment that represents a huge challenge both for the receiving States and for the young Ibero-American institutional migration system. Therefore, we can say that measures to adopt reception and solidarity policies, despite being supported by organs of the multilateral system such as UNHCR and IOM, are not found as guidelines for national and regional action, at the expense of the reactions of the respective public opinions and the influence of what to do of the neighboring countries in the face of the problem.

Keywords: Venezuela, migration, migration policies and governance, Venezuelan diaspora

Procedia PDF Downloads 125
15855 Obesity and Cancer: Current Scientific Evidence and Policy Implications

Authors: Martin Wiseman, Rachel Thompson, Panagiota Mitrou, Kate Allen

Abstract:

Since 1997 World Cancer Research Fund (WCRF) International and the American Institute for Cancer Research (AICR) have been at the forefront of synthesising and interpreting the accumulated scientific literature on the link between diet, nutrition, physical activity and cancer, and deriving evidence-based Cancer Prevention Recommendations. The 2007 WCRF/AICR 2nd Expert Report was a landmark in the analysis of evidence linking diet, body weight and physical activity to cancer and led to the establishment of the Continuous Update Project (CUP). In 2018, as part of the CUP, WCRF/AICR will publish a new synthesis of the current evidence and update the Cancer Prevention Recommendations. This will ensure that everyone - from policymakers and health professionals to members of the public - has access to the most up-to-date information on how to reduce the risk of developing cancer. Overweight and obesity play a significant role in cancer risk, and rates of both are increasing in many parts of the world. This session will give an overview of new evidence relating obesity to cancer since the 2007 report. For example, since the 2007 Report, the number of cancers for which obesity is judged to be a contributory cause has increased from seven to eleven. The session will also shed light on the well-established mechanisms underpinning obesity and cancer links. Additionally, the session will provide an overview of diet and physical activity related factors that promote positive energy imbalance, leading to overweight and obesity. Finally, the session will highlight how policy can be used to address overweight and obesity at a population level, using WCRF International’s NOURISHING Framework. NOURISHING formalises a comprehensive package of policies to promote healthy diets and reduce obesity and non-communicable diseases; it is a tool for policymakers to identify where action is needed and assess if an approach is sufficiently comprehensive. The framework brings together ten policy areas across three domains: food environment, food system, and behaviour change communication. The framework is accompanied by a regularly updated database providing an extensive overview of implemented government policy actions from around the world. In conclusion, the session will provide an overview of obesity and cancer, highlighting the links seen in the epidemiology and exploring the mechanisms underpinning these, as well as the influences that help determine overweight and obesity. Finally, the session will illustrate policy approaches that can be taken to reduce overweight and obesity worldwide.

Keywords: overweight, obesity, nutrition, cancer, mechanisms, policy

Procedia PDF Downloads 149
15854 Seismic Retrofit of Reinforced Concrete Structures by Highly Dissipative Technologies

Authors: Stefano Sorace, Gloria Terenzi, Giulia Mazzieri, Iacopo Costoli

Abstract:

The prolonged earthquake sequence that struck several urban agglomerations and villages in Central Italy, starting from 24 August 2016 through January 2017, highlighted once again the seismic vulnerability of pre-normative reinforced concrete (R/C) structures. At the same time, considerable damages were surveyed in recently retrofitted R/C buildings too, one of which also by means of a dissipative bracing system. The solution adopted for the latter did not expressly take into account the performance of non-structural elements, and namely of infills and partitions, confirming the importance of their dynamic interaction with the structural skeleton. Based on this consideration, an alternative supplemental damping-based retrofit solution for this representative building, i.e., a school with an R/C structure situated in the municipality of Norcia, is examined in this paper. It consists of the incorporation of dissipative braces equipped with pressurized silicone fluid viscous (FV) dampers, instead of the BRAD system installed in the building, the delayed activation of which -caused by the high stiffness of the constituting metallic dampers- determined the observed non-structural damages. Indeed, the alternative solution proposed herein, characterized by dissipaters with mainly damping mechanical properties, guarantees an earlier activation of the protective system. A careful assessment analysis, preliminarily carried out to simulate and check the case study building performance in originally BRAD-retrofitted conditions, confirms that the interstorey drift demand related to the Norcia earthquake's mainshock and aftershocks is beyond the response capacity of infills. The verification analyses developed on the R/C structure, including the FV-damped braces, highlight their higher performance, giving rise to a completely undamaged response both of structural and non-structural elements up to the basic design earthquake normative level of seismic action.

Keywords: dissipative technologies, performance assessment analysis, concrete structures, seismic retrofit

Procedia PDF Downloads 127
15853 Analyzing Speech Acts in Reddit Posts of Formerly Incarcerated Youths

Authors: Yusra Ibrahim

Abstract:

This study explores the online discourse of justice-involved youth on Reddit, focusing on how anonymity and asynchronicity influence their ability to share and reflect on their incarceration experiences within the "Ask Me Anything" (AMA) community. The study utilizes a quantitative analysis of speech acts to examine the varied communication patterns exhibited by youths and commenters across two AMA threads. The results indicate that, although Reddit is not specifically designed for formerly incarcerated youths, its features provide a supportive environment for them to share their incarceration experiences with non-incarcerated individuals. The level of empathy and support from the audience varies based on the audience’s perspectives on incarceration and related traumatic experiences. Additionally, the study identifies a reciprocal relationship where youths benefit from community support while offering insights into the juvenile justice system and helping the audience understand the experience of incarceration. The study also reveals cultural shocks in physical and digital environments that youth experience after release and when using social media platforms and the internet. The study has implications for juvenile justice personnel, policymakers, and researchers in the juvenile justice system.

Keywords: juvenile justice, online discourse, reddit AMA, anonymity, speech acts taxonomy, reintegration, online community support

Procedia PDF Downloads 33
15852 Non-Conformance Clearance through an Intensified Mentorship towards ISO 15189 Accreditation: The Case of Jimma and Hawassa Hospital Microbiology Laboratories, Ethiopia

Authors: Dawit Assefa, Kassaye Tekie, Gebrie Alebachew, Degefu Beyene, Bikila Alemu, Naji Mohammed, Asnakech Agegnehu, Seble Tsehay, Geremew Tasew

Abstract:

Background: Implementation of a Laboratory Quality Management System (LQMS) is critical to ensure accurate, reliable, and efficient laboratory testing of antimicrobial resistance (AMR). However, limited LQMS implementation and progress toward accreditation in the AMR surveillance laboratory testing setting exist in Ethiopia. By addressing non-conformances (NCs) and working towards accreditation, microbiology laboratories can improve the quality of their services, increase staff competence, and contribute to mitigate the spread of AMR. Methods: Using standard ISO 15189 horizontal and vertical assessment checklists, certified assessors identified NCs at Hawassa and Jimma Hospital microbiology laboratories. The Ethiopian Public Health Institute AMR mentors and IDDS staff prioritized closing the NCs through the implementation of an intensified mentorship program that included ISO 15189 orientation training, resource allocation, and action plan development. Results: For the two facilities to clear their NCs, an intensified mentorship approach was adopted by providing ISO 15189 orientation training, provision of buffer reagents, controls, standards, and axillary equipment, and facilitating equipment maintenance and calibration. Method verification and competency assessment were also conducted along with the implementation of standard operating procedures and recommended corrective actions. This approach enhanced the laboratory's readiness for accreditation. After addressing their NCs, the two laboratories applied to Ethiopian Accreditation Services for ISO 15189 accreditation. Conclusions: Clearing NCs through the implementation of intensified mentorship was crucial in preparing the two laboratories for accreditation and improving quality laboratory test results. This approach can guide other microbiology laboratories’ accreditation attainment efforts.

Keywords: non-conformance clearance, intensified mentorship, accreditation, ISO 15189

Procedia PDF Downloads 73
15851 Recent Developments in E-waste Management in India

Authors: Rajkumar Ghosh, Bhabani Prasad Mukhopadhay, Ananya Mukhopadhyay, Harendra Nath Bhattacharya

Abstract:

This study investigates the global issue of electronic waste (e-waste), focusing on its prevalence in India and other regions. E-waste has emerged as a significant worldwide problem, with India contributing a substantial share of annual e-waste generation. The primary sources of e-waste in India are computer equipment and mobile phones. Many developed nations utilize India as a dumping ground for their e-waste, with major contributions from the United States, China, Europe, Taiwan, South Korea, and Japan. The study identifies Maharashtra, Tamil Nadu, Mumbai, and Delhi as prominent contributors to India's e-waste crisis. This issue is contextualized within the broader framework of the United Nations' 2030 Agenda for Sustainable Development, which encompasses 17 Sustainable Development Goals (SDGs) and 169 associated targets to address poverty, environmental preservation, and universal prosperity. The study underscores the interconnectedness of e-waste management with several SDGs, including health, clean water, economic growth, sustainable cities, responsible consumption, and ocean conservation. Central Pollution Control Board (CPCB) data reveals that e-waste generation surpasses that of plastic waste, increasing annually at a rate of 31%. However, only 20% of electronic waste is recycled through organized and regulated methods in underdeveloped nations. In Europe, efficient e-waste management stands at just 35%. E-waste pollution poses serious threats to soil, groundwater, and public health due to toxic components such as mercury, lead, bromine, and arsenic. Long-term exposure to these toxins, notably arsenic in microchips, has been linked to severe health issues, including cancer, neurological damage, and skin disorders. Lead exposure, particularly concerning for children, can result in brain damage, kidney problems, and blood disorders. The study highlights the problematic transboundary movement of e-waste, with approximately 352,474 metric tonnes of electronic waste illegally shipped from Europe to developing nations annually, mainly to Africa, including Nigeria, Ghana, and Tanzania. Effective e-waste management, underpinned by appropriate infrastructure, regulations, and policies, offers opportunities for job creation and aligns with the objectives of the 2030 Agenda for SDGs, especially in the realms of decent work, economic growth, and responsible production and consumption. E-waste represents hazardous pollutants and valuable secondary resources, making it a focal point for anthropogenic resource exploitation. The United Nations estimates that e-waste holds potential secondary raw materials worth around 55 billion Euros. The study also identifies numerous challenges in e-waste management, encompassing the sheer volume of e-waste, child labor, inadequate legislation, insufficient infrastructure, health concerns, lack of incentive schemes, limited awareness, e-waste imports, high costs associated with recycling plant establishment, and more. To mitigate these issues, the study offers several solutions, such as providing tax incentives for scrap dealers, implementing reward and reprimand systems for e-waste management compliance, offering training on e-waste handling, promoting responsible e-waste disposal, advancing recycling technologies, regulating e-waste imports, and ensuring the safe disposal of domestic e-waste. A mechanism, Buy-Back programs, will compensate customers in cash when they deposit unwanted digital products. This E-waste could contain any portable electronic device, such as cell phones, computers, tablets, etc. Addressing the e-waste predicament necessitates a multi-faceted approach involving government regulations, industry initiatives, public awareness campaigns, and international cooperation to minimize environmental and health repercussions while harnessing the economic potential of recycling and responsible management.

Keywords: e-waste management, sustainable development goal, e-waste disposal, recycling technology, buy-back policy

Procedia PDF Downloads 74
15850 Changes in Consumption Pattern of Western Consumers and Its Effect to the Ottoman Oriental Carpet-Making Industry

Authors: Emine Zeytinli

Abstract:

Ottoman carpets were depicted in Renaissance painting while they were exported commercially. The carpets were highly demanded and used by the middle and upper classes of Western European countries. The motifs, designs, patterns, and ornamentation of these carpets were decorative objects of luxury for Western European residences as well as paintings. Oriental carpets found their way into European market already from the medieval times to the present century. They were considered as luxury items first, however, demanded by middle classes in Europe and North America within the nineteenth century. This century brought unprecedented changes in production and consumption in the world. Expanding industries created quick urbanization, changed the city life and new types of goods dominated the entire century. Increases in income allowed Europeans to spend on luxury items, consumers taste changed in number of ways including furniture and decoration. Use of a carpet in the orient lifestyle often considered as an art object with Western aesthetic sensibility. A carpet with an oriental character, an essential part of home decoration, was highly appreciated for floor, table covering and wall hanging. Turkish carpets with distinctive classical style, patterns, and colours were changed for the tastes of European consumers. This paper attempts to analyse how the taste and preferences of European and American consumers increased their buying of oriental objects namely carpets. The production of local hand woven carpet industry developed, carpet factories were set up and special weaving schools were opened in some major waving centres, and carpet weaving became one of the main manufacturing and export commodity of the empire. All of these attempts increased the reputation and market share in international market. The industry flourished, commercially operated carpet looms, sales revenues and export increased unprecedentedly. British and Ottoman archival documents, parliamentary papers and travel notes were used to analysed above mention effect on how the foreign demand changed designs of carpets and the business itself, how the production in households moved to the commercial premises and a flourished the industry.

Keywords: consumption patterns, carpet weaving, ottoman oriental carpets, commercialisation

Procedia PDF Downloads 130
15849 Comparison of Multivariate Adaptive Regression Splines and Random Forest Regression in Predicting Forced Expiratory Volume in One Second

Authors: P. V. Pramila , V. Mahesh

Abstract:

Pulmonary Function Tests are important non-invasive diagnostic tests to assess respiratory impairments and provides quantifiable measures of lung function. Spirometry is the most frequently used measure of lung function and plays an essential role in the diagnosis and management of pulmonary diseases. However, the test requires considerable patient effort and cooperation, markedly related to the age of patients esulting in incomplete data sets. This paper presents, a nonlinear model built using Multivariate adaptive regression splines and Random forest regression model to predict the missing spirometric features. Random forest based feature selection is used to enhance both the generalization capability and the model interpretability. In the present study, flow-volume data are recorded for N= 198 subjects. The ranked order of feature importance index calculated by the random forests model shows that the spirometric features FVC, FEF 25, PEF,FEF 25-75, FEF50, and the demographic parameter height are the important descriptors. A comparison of performance assessment of both models prove that, the prediction ability of MARS with the `top two ranked features namely the FVC and FEF 25 is higher, yielding a model fit of R2= 0.96 and R2= 0.99 for normal and abnormal subjects. The Root Mean Square Error analysis of the RF model and the MARS model also shows that the latter is capable of predicting the missing values of FEV1 with a notably lower error value of 0.0191 (normal subjects) and 0.0106 (abnormal subjects). It is concluded that combining feature selection with a prediction model provides a minimum subset of predominant features to train the model, yielding better prediction performance. This analysis can assist clinicians with a intelligence support system in the medical diagnosis and improvement of clinical care.

Keywords: FEV, multivariate adaptive regression splines pulmonary function test, random forest

Procedia PDF Downloads 304
15848 Combustion Analysis of Suspended Sodium Droplet

Authors: T. Watanabe

Abstract:

Combustion analysis of suspended sodium droplet is performed by solving numerically the Navier-Stokes equations and the energy conservation equations. The combustion model consists of the pre-ignition and post-ignition models. The reaction rate for the pre-ignition model is based on the chemical kinetics, while that for the post-ignition model is based on the mass transfer rate of oxygen. The calculated droplet temperature is shown to be in good agreement with the existing experimental data. The temperature field in and around the droplet is obtained as well as the droplet shape variation, and the present numerical model is confirmed to be effective for the combustion analysis.

Keywords: analysis, combustion, droplet, sodium

Procedia PDF Downloads 205
15847 Risk Mitigation of Data Causality Analysis Requirements AI Act

Authors: Raphaël Weuts, Mykyta Petik, Anton Vedder

Abstract:

Artificial Intelligence has the potential to create and already creates enormous value in healthcare. Prescriptive systems might be able to make the use of healthcare capacity more efficient. Such systems might entail interpretations that exclude the effect of confounders that brings risks with it. Those risks might be mitigated by regulation that prevents systems entailing such risks to come to market. One modality of regulation is that of legislation, and the European AI Act is an example of such a regulatory instrument that might mitigate these risks. To assess the risk mitigation potential of the AI Act for those risks, this research focusses on a case study of a hypothetical application of medical device software that entails the aforementioned risks. The AI Act refers to the harmonised norms for already existing legislation, here being the European medical device regulation. The issue at hand is a causal link between a confounder and the value the algorithm optimises for by proxy. The research identifies where the AI Act already looks at confounders (i.a. feedback loops in systems that continue to learn after being placed on the market). The research identifies where the current proposal by parliament leaves legal uncertainty on the necessity to check for confounders that do not influence the input of the system, when the system does not continue to learn after being placed on the market. The authors propose an amendment to article 15 of the AI Act that would require high-risk systems to be developed in such a way as to mitigate risks from those aforementioned confounders.

Keywords: AI Act, healthcare, confounders, risks

Procedia PDF Downloads 253
15846 Practical Software for Optimum Bore Hole Cleaning Using Drilling Hydraulics Techniques

Authors: Abdulaziz F. Ettir, Ghait Bashir, Tarek S. Duzan

Abstract:

A proper well planning is very vital to achieve any successful drilling program on the basis of preventing, overcome all drilling problems and minimize cost operations. Since the hydraulic system plays an active role during the drilling operations, that will lead to accelerate the drilling effort and lower the overall well cost. Likewise, an improperly designed hydraulic system can slow drill rate, fail to clean the hole of cuttings, and cause kicks. In most cases, common sense and commercially available computer programs are the only elements required to design the hydraulic system. Drilling optimization is the logical process of analyzing effects and interactions of drilling variables through applied drilling and hydraulic equations and mathematical modeling to achieve maximum drilling efficiency with minimize drilling cost. In this paper, practical software adopted in this paper to define drilling optimization models including four different optimum keys, namely Opti-flow, Opti-clean, Opti-slip and Opti-nozzle that can help to achieve high drilling efficiency with lower cost. The used data in this research from vertical and horizontal wells were recently drilled in Waha Oil Company fields. The input data are: Formation type, Geopressures, Hole Geometry, Bottom hole assembly and Mud reghology. Upon data analysis, all the results from wells show that the proposed program provides a high accuracy than that proposed from the company in terms of hole cleaning efficiency, and cost break down if we consider that the actual data as a reference base for all wells. Finally, it is recommended to use the established Optimization calculations software at drilling design to achieve correct drilling parameters that can provide high drilling efficiency, borehole cleaning and all other hydraulic parameters which assist to minimize hole problems and control drilling operation costs.

Keywords: optimum keys, namely opti-flow, opti-clean, opti-slip and opti-nozzle

Procedia PDF Downloads 316
15845 Microalgae Hydrothermal Liquefaction Process Optimization and Comprehension to Produce High Quality Biofuel

Authors: Lucie Matricon, Anne Roubaud, Geert Haarlemmer, Christophe Geantet

Abstract:

Introduction: This case discusses the management of two floor of mouth (FOM) Squamous Cell Carcinomas (SCC) not identified upon initial biopsy. Case Report: A 51 year-old male presented with right FOM erythroleukoplakia. Relevant medical history included alcoholic dependence syndrome and alcoholic liver disease. Relevant drug therapy encompassed acamprosate, folic acid, hydroxocobalamin and thiamine. The patient had a 55.5 pack-year smoking history and alcohol dependence from age 14, drinking 16 units/day. FOM incisional biopsy and histopathological analysis diagnosed Carcinoma in situ. Treatment involved wide local excision. Specimen analysis revealed two separate foci of pT1 moderately differentiated SCCs. Carcinoma staging scans revealed no pathological lymphadenopathy, no local invasion or metastasis. SCCs had been excised in completion with narrow margins. MDT discussion concluded that in view of the field changes it would be difficult to identify specific areas needing further excision, although techniques such as Lugol’s Iodine were considered. Further surgical resection, surgical neck management and sentinel lymph node biopsy was offered. The patient declined intervention, primary management involved close monitoring alongside alcohol and smoking cessation referral. Discussion: Narrow excisional margins can increase carcinoma recurrence risk. Biopsy failed to identify SCCs, despite sampling an area of clinical concern. For gross field change multiple incisional biopsies should be considered to increase chance of accurate diagnosis and appropriate treatment. Coupling of tobacco and alcohol has a synergistic effect, exponentially increasing the relative risk of oral carcinoma development. Tobacco and alcoholic control is fundamental in reducing treatment‑related side effects, recurrence risk, and second primary cancer development.

Keywords: microalgae, biofuels, hydrothermal liquefaction, biomass

Procedia PDF Downloads 127
15844 Three or Four Tonics and a Wave: The Trajectory of Health Insurance Regulation in Brazil

Authors: João Boaventura Branco De Matos

Abstract:

Currently, in Brazil, there is a considerable collection of publications on the supplementary health sector, but the vast majority is limited to retrospective examination of the sector. The present contribution starts from the diagnosis of an overwhelming change in the role of the State and its institutions, as well as an accelerated and no less forceful change in the way of producing goods and services, resulting in a clash between these different waves (state and market). This shock produces unique energy, capable of imposing major changes in the most varied sectors. Based on this diagnosis, there was an opportunity to offer the perspective and propositional study of regulatory measures relevant to the best conduct and performance of this sector in the future.

Keywords: private health regulation, state and market, forecasts in Brazilian regulation, political economy

Procedia PDF Downloads 142
15843 Comparison of Regional and Local Indwelling Catheter Techniques to Prolong Analgesia in Total Knee Arthroplasty Procedures: Continuous Peripheral Nerve Block and Continuous Periarticular Infiltration

Authors: Jared Cheves, Amanda DeChent, Joyce Pan

Abstract:

Total knee replacements (TKAs) are one of the most common but painful surgical procedures performed in the United States. Currently, the gold standard for postoperative pain management is the utilization of opioids. However, in the wake of the opioid epidemic, the healthcare system is attempting to reduce opioid consumption by trialing innovative opioid sparing analgesic techniques such as continuous peripheral nerve blocks (CPNB) and continuous periarticular infiltration (CPAI). The alleviation of pain, particularly during the first 72 hours postoperatively, is of utmost importance due to its association with delayed recovery, impaired rehabilitation, immunosuppression, the development of chronic pain, the development of rebound pain, and decreased patient satisfaction. While both CPNB and CPAI are being used today, there is limited evidence comparing the two to the current standard of care or to each other. An extensive literature review was performed to explore the safety profiles and effectiveness of CPNB and CPAI in reducing reported pain scores and decreasing opioid consumption. The literature revealed the usage of CPNB contributed to lower pain scores and decreased opioid use when compared to opioid-only control groups. Additionally, CPAI did not improve pain scores or decrease opioid consumption when combined with a multimodal analgesic (MMA) regimen. When comparing CPNB and CPAI to each other, neither unanimously lowered pain scores to a greater degree, but the literature indicates that CPNB decreased opioid consumption more than CPAI. More research is needed to further cement the efficacy of CPNB and CPAI as standard components of MMA in TKA procedures. In addition, future research can also focus on novel catheter-free applications to reduce the complications of continuous catheter analgesics.

Keywords: total knee arthroplasty, continuous peripheral nerve blocks, continuous periarticular infiltration, opioid, multimodal analgesia

Procedia PDF Downloads 84
15842 Haemoperitoneum in a Case of Dengue Fever

Authors: Sagarjyoti Roy

Abstract:

Dengue is an arboviral infection, belonging to family flaviviridae, comprising of four serotypes; DENV1, DENV2, DENV3 and DENV4. All four serotypes are capable of causing full-spectrum of clinical features, ranging from self-limiting fever to severe dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Complications may affect any organ system, including those involving gastrointestinal system and serositis. We report a case, of a 28 years, non-alcoholic male, presenting with a 7 day history of fever and malaise followed by abdominal pain and distension, from 4th day of fever. He was admitted in medicine department of RG KAR medical college hospital. Dengue fever was confirmed by NS1 and dengue IgM positivity. Platelet count was 30,000/cc (1.5- 4 lac/cc) and haematocrit was 52% (38- 50% for men). Clinicoradiological findings revealed bilateral pleural effusion, ascites and splenomegaly. Ascitic fluid was hemorrhagic in nature, with a high protein and RBC content. Liver function tests revealed mild transaminitis with normal coagulation profile. Patient was managed conservatively. A diagnosis of dengue fever complicated by serositis and spontaneous haemoperitoneum was made. The symptoms subsided after a hospital stay of 10 days. The case highlights haemorrhage into peritoneal cavity as a possible complication of dengue fever. Although a definite explanation requires more detailed studies, platelet or endothelial cell dysfunction might be contributory.

Keywords: ascites, dengue, haemoperitoneum, serositis

Procedia PDF Downloads 256
15841 Kinetics and Mechanism of Oxidation of Some Amino Acids by Peroxodisulphate

Authors: Abdelmahmod Saad

Abstract:

In this study two amino acids were chosen (DL.alanine,DL.serine) to determine their effect on dissociation of S2O8-2 ino. As the reaction was very slow, Ag+ ino was used as a catalyst. The kinetics measurement showed that the reactions in both cases were found in the first order with respect to S2O8-2, half order with respect to Ag+ and zero order with respect to substrates. Mechanisms were proposed for these reactions according to the determined orders. The energy of activation (AE) was determined for each reaction, and was found to by 30.50 k JmoI-1 in case of DL. Serine and 24.40 k JmoI-1 in case of DL.alanine.

Keywords: mechanism, oxidation, amino acids, peroxodisulphate

Procedia PDF Downloads 505
15840 An Experimental Study on the Coupled Heat Source and Heat Sink Effects on Solid Rockets

Authors: Vinayak Malhotra, Samanyu Raina, Ajinkya Vajurkar

Abstract:

Enhancing the rocket efficiency by controlling the external factors in solid rockets motors has been an active area of research for most of the terrestrial and extra-terrestrial system operations. Appreciable work has been done, but the complexity of the problem has prevented thorough understanding due to heterogenous heat and mass transfer. On record, severe issues have surfaced amounting to irreplaceable loss of mankind, instruments, facilities, and huge amount of money being invested every year. The coupled effect of an external heat source and external heat sink is an aspect yet to be articulated in combustion. Better understanding of this coupled phenomenon will induce higher safety standards, efficient missions, reduced hazard risks, with better designing, validation, and testing. The experiment will help in understanding the coupled effect of an external heat sink and heat source on the burning process, contributing in better combustion and fire safety, which are very important for efficient and safer rocket flights and space missions. Safety is the most prevalent issue in rockets, which assisted by poor combustion efficiency, emphasizes research efforts to evolve superior rockets. This signifies real, engineering, scientific, practical, systems and applications. One potential application is Solid Rocket Motors (S.R.M). The study may help in: (i) Understanding the effect on efficiency of core engines due to the primary boosters if considered as source, (ii) Choosing suitable heat sink materials for space missions so as to vary the efficiency of the solid rocket depending on the mission, (iii) Giving an idea about how the preheating of the successive stage due to previous stage acting as a source may affect the mission. The present work governs the temperature (resultant) and thus the heat transfer which is expected to be non-linear because of heterogeneous heat and mass transfer. The study will deepen the understanding of controlled inter-energy conversions and the coupled effect of external source/sink(s) surrounding the burning fuel eventually leading to better combustion thus, better propulsion. The work is motivated by the need to have enhanced fire safety and better rocket efficiency. The specific objective of the work is to understand the coupled effect of external heat source and sink on propellant burning and to investigate the role of key controlling parameters. Results as of now indicate that there exists a singularity in the coupled effect. The dominance of the external heat sink and heat source decides the relative rocket flight in Solid Rocket Motors (S.R.M).

Keywords: coupled effect, heat transfer, sink, solid rocket motors, source

Procedia PDF Downloads 217
15839 In-situ Raman Spectroscopy of Flexible Graphene Oxide Films Containing Pt Nanoparticles in The Presense of Atomic Hydrogen

Authors: Ali Moafi, Kourosh Kalantarzadeh, Richard Kaner, Parviz Parvin, Ebrahim Asl Soleimani, Dougal McCulloch

Abstract:

In-situ Raman spectroscopy of flexible graphene-oxide films examined upon exposure to hydrogen gas, air, and synthetic air. The changes in D and G peaks are attributed to defects responding to atomic hydrogen spilled over from the catalytic behavior of Pt nanoparticles distributed all over the film. High-resolution transmission electron microscopy images (HRTEM) as well as electron energy loss spectroscopy (EELS) were carried out to define the density of the samples.

Keywords: in situ Raman Spectroscopy, EELS, TEM, graphene oxide, graphene, atomic hydrogen

Procedia PDF Downloads 443
15838 Ancient Malay and Spice Trade Routes: A Study of Ancient Malay from the Perspectives of Linguistics and Archaeology

Authors: Totok Suhardijanto, Ninie Susanti Tedjowasono

Abstract:

This paper discusses the relationship between the distribution of Ancient Malay inscriptions and Spice Trade Route, especially in the relation with material cultures that accompany them, to understand how Malay could spread out around the archipelago beyond its original native-speakers’ region. The archipelago was known as the Spice Islands from the very beginning of the first century due to mace, cloves, and nutmeg that were originally exclusively found there. According to the Indian record, since the 2nd century, there has been a contact established between Indian and Indonesian people. A Chinese document from 3rd Century has mentioned Wangka (now widely known as Bangka) an island near Sumatra where some Chinese expeditions had visited. All of these records supported the existence of a maritime trade system and route between the archipelago and other countries during the first millennium. This paper will discuss first the Ancient Malay inscription spread around the archipelago from the perspectives of language variation and writing system style. Analyzing language variations of inscriptions certainly is not as easy as studying current spoken language variations in modern sociolinguistics. A huge amount of data is available for such kind of studies. On the contrary, in language variation research with inscription texts as an object, data is insufficient. Other resources will be needed to support the linguistic analysis. For this reason, this research made use of epigraphical evidence in the surrounding areas of the inscriptions to explain the variation of language and writing style. The research next expands the analysis to figure out the relationship between language variation and inscriptions distribution to the Spice Trade Route that spreads from the Molucca Sea to Mediterranian Sea. Data in this research consists of six different inscriptions: Kedukan Bukit, Koto Kapur, Dapunta Salendra, Sang Hyang Wintang, Ligor, and Laguna from the 7th-9th Century and found in Sumatra, Jawa, and the Philippines. In addition, as a comparative resource, this research also used Hikayat Tanjung Tanah, the first-founded Ancient Malay manuscript. In language analysis, we conduct a sociolinguistic method to explore the language variation and writing style of the inscriptions. For dealing with archaeological data, we conducted a hermeneutic method to analyze the possible meaning and social uses of the data. Language variations and writing system style in this research can be classified into two main groups. The language, epigraphical, and archaeological evidence explain that Ancient Malay had been widely used in the Eastern area of Spice Trade Route because it played an important role in the region as a lingua franca between people from different ethnic groups with different languages.

Keywords: Ancient Malay, Spice trade route, language variation, writing system variation

Procedia PDF Downloads 185
15837 Israeli Households Caring for Children and Adults with Intellectual and Developmental Disabilities: An Explorative Study

Authors: Ayelet Gur

Abstract:

Background: In recent years we are witnessing a welcome trend in which more children/persons with disabilities are living at home with their families and within their communities. This trend is related to various policy innovations as the UN Convention on the Rights of People with Disabilities that reflect a shift from the medical-institutional model to a human rights approach. We also witness the emergence of family centered approaches that perceive the family and not just the individual with the disability as a worthy target of policy planning, implementation and evaluation efforts. The current investigation aims to explore economic, psychological and social factors among households of families of children or adults with intellectual disabilities in Israel and to present policy recommendation. Methods: A national sample of 301 households was recruited through the education and employment settings of persons with intellectual disability. The main caregiver of the person with the disability (a parent) was interviewed. Measurements included the income and expense surveys; assets and debts questionnaire; the questionnaire on resources and stress; the social involvement questionnaire and Personal Wellbeing Index. Results: Findings indicate significant gaps in financial circumstances between households of families of children with intellectual disabilities and households of the general Israeli society. Households of families of children with intellectual disabilities report lower income and higher expenditures and loans than the general society. They experience difficulties in saving and coping with unexpected expenses. Caregivers (the parents) experience high stress, low social participation, low financial support from family, friend and non-governmental organizations and decreased well-being. They are highly dependent on social security allowances which constituted 40% of the household's income. Conclusions: Households' dependency on social security allowances may seem contradictory to the encouragement of persons with intellectual disabilities to favor independent living in light of the human rights approach to disability. New policy should aim at reducing caregivers' stress and enhance their social participation and support, with special emphasis on families of lower socio-economic status. Finally, there is a need to continue monitoring the economic and psycho-social needs of households of families of children with intellectual disabilities and other developmental disabilities.

Keywords: disability policy, family policy, intellectual and developmental disabilities, Israel, households study, parents of children with disabilities

Procedia PDF Downloads 151
15836 Maternity Care Model during Natural Disaster or Humanitarian Emegerncy Setting in Rural Pakistan

Authors: Humaira Maheen, Elizabeth Hoban, Catherine Bennette

Abstract:

Background: Globally, role of Community Health Workers (CHW) as front line disaster health work force is underutilized. Developing countries which are at risk of natural disasters or humanitarian emergencies should lay down effective strategies especially to ensure adequate access to maternity care during crisis situation by using CHW as they are local, trained, and most of them possess a good relationship with the community. The Minimum Initial Service Package (MISP) is a set of universal guidelines that addresses women’s reproductive health needs during the first phase of an emergency. According to the MISP, pregnant women should have access to a skilled birth attendant and adequate transportation arrangements so they can access a maternity care facility. Pakistan is one of the few countries which has been severely affected by a number of natural disaster as well as humanitarian emergencies in last decade. Pakistan has a young and structured National Disaster Management System in place, where District Authorities play a vital role in disaster management. The District Health Department develops the contingency health plan for an emergency situation and implements it under the existing district health human resources (health workers and medical staff at the health facility) and infrastructure (health care facilities). Methods: A mixed methods study was conducted in rural villages of Sindh adjacent to the river Indus, and included in-depth interviews with 15 women who gave birth during the floods, structured interviews with 668 women who were pregnant during 2010-2014, and in-depth interviews with 25 community health workers (CHW) and 30 key informants. Results: Women said that giving birth in the relief camps during the floods was one of the most challenging times of their life. The district health department didn’t make transportation arrangement for labouring women from relief camp to the nearest health care facility. As a result 91.2% women gave birth in temporary shelters with the help of a traditional birth attendant (Dai) with no clean physical space available to birth. Of the 332 women who were pregnant at the time of the floods, 26 had adverse birth outcomes; 10 had miscarriages, 14 had stillbirths and there were four neonatal deaths. Conclusion: The district health department was not able to provide access to adequate maternity care during according to the international standard during the floods in 2011. We propose a model where CHWs will be used as frontline maternity care providers during any emergency or disaster situations in Pakistan. A separate "birthing station" should be mandatory in all district relief camps, managed by CHWs. Community midwives (CMW) would and the Lady Health Workers (LHW) would provide antenatal and postnatal care alongside, vaccination for pregnant women, neonates and children under five. There must be an ambulance facility for emergency obstetric cases and all district health facilities should have at least two medical staff identified and trained for emergency obstetric management. The District Health Department must provide clean birthing kits and regular and emergency contraceptives in the relief camps. Methods: A mixed methods study was conducted in rural villages of Sindh adjacent to the river Indus, and included in-depth interviews with 15 women who gave birth during the floods, structured interviews with 668 women who were pregnant during 2010-2014, and in-depth interviews with 25 community health workers (CHW) and 30 key informants. Results: Women said that giving birth in the relief camps during the floods was one of the most challenging times of their life. Nearly 91.2% women gave birth in temporary shelters with the help of a traditional birth attendant (Dai) with no clean physical space available to birth, and the health camp was mostly accessed by men and always overcrowded. There was no obstetric trained medical staff in the health camps or transportation provided to take women with complications to the nearest health facility. The rate of adverse outcome following disaster was 22.2% (95% CI: 8.62% – 42.2%) amongst 27 women who did not evacuate as compare to 7.91% (95% CI: 5.03% – 11.8%) among 278 women who lived in relief camp study participants. There were 27 women who evacuated on pre-flood warning and had 0% rate of adverse outcome. Conclusion: We propose a model where CHWs will be used as frontline maternity care providers during any emergency or disaster situations in Pakistan. A separate "birthing station" should be mandatory in all district relief camps, managed by CHWs. Community midwives (CMW) would and the Lady Health Workers (LHW) would provide antenatal and postnatal care alongside, vaccination for pregnant women, neonates and children under five. There must be an ambulance facility for emergency obstetric cases and all district health facilities should have at least two medical staff identified and trained for emergency obstetric management. The District Health Department must provide clean birthing kits and regular and emergency contraceptives in the relief camps.

Keywords: natural disaster, maternity care model, rural, Pakistan, community health workers

Procedia PDF Downloads 258
15835 Effect of Spatially Correlated Disorder on Electronic Transport Properties of Aperiodic Superlattices (GaAs/AlxGa1-xAs)

Authors: F. Bendahma, S. Bentata, S. Cherid, A. Zitouni, S. Terkhi, T. Lantri, Y. Sefir, Z. F. Meghoufel

Abstract:

We examine the electronic transport properties in AlxGa1-xAs/GaAs superlattices. Using the transfer-matrix technique and the exact Airy function formalism, we investigate theoretically the effect of structural parameters on the electronic energy spectra of trimer thickness barrier (TTB). Our numerical calculations showed that the localization length of the states becomes more extended when the disorder is correlated (trimer case). We have also found that the resonant tunneling time (RTT) is of the order of several femtoseconds.

Keywords: electronic transport properties, structural parameters, superlattices, transfer-matrix technique

Procedia PDF Downloads 280
15834 Empirical Orthogonal Functions Analysis of Hydrophysical Characteristics in the Shira Lake in Southern Siberia

Authors: Olga S. Volodko, Lidiya A. Kompaniets, Ludmila V. Gavrilova

Abstract:

The method of empirical orthogonal functions is the method of data analysis with a complex spatial-temporal structure. This method allows us to decompose the data into a finite number of modes determined by empirically finding the eigenfunctions of data correlation matrix. The modes have different scales and can be associated with various physical processes. The empirical orthogonal function method has been widely used for the analysis of hydrophysical characteristics, for example, the analysis of sea surface temperatures in the Western North Atlantic, ocean surface currents in the North Carolina, the study of tropical wave disturbances etc. The method used in this study has been applied to the analysis of temperature and velocity measurements in saline Lake Shira (Southern Siberia, Russia). Shira is a shallow lake with the maximum depth of 25 m. The lake Shira can be considered as a closed water site because of it has one small river providing inflow and but it has no outflows. The main factor that causes the motion of fluid is variable wind flows. In summer the lake is strongly stratified by temperature and saline. Long-term measurements of the temperatures and currents were conducted at several points during summer 2014-2015. The temperature has been measured with an accuracy of 0.1 ºC. The data were analyzed using the empirical orthogonal function method in the real version. The first empirical eigenmode accounts for 70-80 % of the energy and can be interpreted as temperature distribution with a thermocline. A thermocline is a thermal layer where the temperature decreases rapidly from the mixed upper layer of the lake to much colder deep water. The higher order modes can be interpreted as oscillations induced by internal waves. The currents measurements were recorded using Acoustic Doppler Current Profilers 600 kHz and 1200 kHz. The data were analyzed using the empirical orthogonal function method in the complex version. The first empirical eigenmode accounts for about 40 % of the energy and corresponds to the Ekman spiral occurring in the case of a stationary homogeneous fluid. Other modes describe the effects associated with the stratification of fluids. The second and next empirical eigenmodes were associated with dynamical modes. These modes were obtained for a simplified model of inhomogeneous three-level fluid at a water site with a flat bottom.

Keywords: Ekman spiral, empirical orthogonal functions, data analysis, stratified fluid, thermocline

Procedia PDF Downloads 132
15833 Improved Multilevel Inverter with Hybrid Power Selector and Solar Panel Cleaner in a Solar System

Authors: S. Oladoyinbo, A. A. Tijani

Abstract:

Multilevel inverters (MLI) are used at high power application based on their operation. There are 3 main types of multilevel inverters (MLI); diode clamped, flying capacitor and cascaded MLI. A cascaded MLI requires the least number of components to achieve same number of voltage levels when compared to other types of MLI while the flying capacitor has the minimum harmonic distortion. However, maximizing the advantage of cascaded H-bridge MLI and flying capacitor MLI, an improved MLI can be achieved with fewer components and better performance. In this paper an improved MLI is presented by asymmetrically integrating a flying capacitor to a cascaded H-bridge MLI also integrating an auxiliary transformer to the main transformer to decrease the total harmonics distortion (THD) with increased number of output voltage levels. Furthermore, the system is incorporated with a hybrid time and climate based solar panel cleaner and power selector which intelligently manage the input of the MLI and clean the solar panel weekly ensuring the environmental factor effect on the panel is reduced to minimum.

Keywords: multilevel inverter, total harmonics distortion, cascaded h-bridge inverter, flying capacitor

Procedia PDF Downloads 354