Search results for: Anderson Braga Mendes
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 176

Search results for: Anderson Braga Mendes

86 Status of the European Atlas of Natural Radiation

Authors: G. Cinelli, T. Tollefsen, P. Bossew, V. Gruber, R. Braga, M. A. Hernández-Ceballos, M. De Cort

Abstract:

In 2006, the Joint Research Centre (JRC) of the European Commission started the project of the 'European Atlas of Natural Radiation'. The Atlas aims at preparing a collection of maps of Europe displaying the levels of natural radioactivity caused by different sources (indoor and outdoor radon, cosmic radiation, terrestrial radionuclides, terrestrial gamma radiation, etc). The overall goal of the project is to estimate, in geographical resolution, the annual dose that the public may receive from natural radioactivity, combining all the information from the different radiation components. The first map which has been developed is the European map of indoor radon (Rn) since in most cases Rn is the most important contribution to exposure. New versions of the map are realised when new countries join the project or when already participating countries send new data. We show the latest status of this map which currently includes 25 European countries. Second, the JRC has undertaken to map a variable which measures 'what earth delivers' in terms of Rn. The corresponding quantity is called geogenic radon potential (RP). Due to the heterogeneity of data sources across the Europe there is need to develop a harmonized quantity which at the one hand adequately measures or classifies the RP, and on the other hand is suited to accommodate the variety of input data used to estimate this target quantity. Candidates for input quantities which may serve as predictors of the RP, and for which data are available across Europe, to different extent, are Uranium (U) concentration in rocks and soils, soil gas radon and soil permeability, terrestrial gamma dose rate, geological information and indoor data from ground floor. The European Geogenic Radon Map gives the possibility to characterize areas, on European geographical scale, for radon hazard where indoor radon measurements are not available. Parallel to ongoing work on the European Indoor Radon, Geogenic Radon and Cosmic Radiation Maps, we made progress in the development of maps of terrestrial gamma radiation and U, Th and K concentrations in soil and bedrock. We show the first, preliminary map of the terrestrial gamma dose rate, estimated using the data of ambient dose equivalent rate available from the EURDEP system (about 5000 fixed monitoring stations across Europe). Also, the first maps of U, Th, and K concentrations in soil and bedrock are shown in the present work.

Keywords: Europe, natural radiation, mapping, indoor radon

Procedia PDF Downloads 272
85 Frequency Analysis of Minimum Ecological Flow and Gage Height in Indus River Using Maximum Likelihood Estimation

Authors: Tasir Khan, Yejuan Wan, Kalim Ullah

Abstract:

Hydrological frequency analysis has been conducted to estimate the minimum flow elevation of the Indus River in Pakistan to protect the ecosystem. The Maximum likelihood estimation (MLE) technique is used to estimate the best-fitted distribution for Minimum Ecological Flows at nine stations of the Indus River in Pakistan. The four selected distributions, Generalized Extreme Value (GEV) distribution, Generalized Logistics (GLO) distribution, Generalized Pareto (GPA) distribution, and Pearson type 3 (PE3) are fitted in all sites, usually used in hydro frequency analysis. Compare the performance of these distributions by using the goodness of fit tests, such as the Kolmogorov Smirnov test, Anderson darling test, and chi-square test. The study concludes that the Maximum Likelihood Estimation (MLE) method recommended that GEV and GPA are the most suitable distributions which can be effectively applied to all the proposed sites. The quantiles are estimated for the return periods from 5 to 1000 years by using MLE, estimations methods. The MLE is the robust method for larger sample sizes. The results of these analyses can be used for water resources research, including water quality management, designing irrigation systems, determining downstream flow requirements for hydropower, and the impact of long-term drought on the country's aquatic system.

Keywords: minimum ecological flow, frequency distribution, indus river, maximum likelihood estimation

Procedia PDF Downloads 58
84 Theoretical Investigation of the Origin of Interfacial Ferromagnetism of (LaNiO₃)n/(CaMnO₃)m Superlattices

Authors: Jiwuer Jilili, Iogann Tolbatov, Mousumi U. Kahaly

Abstract:

Metal to insulator transition and interfacial magnetism of the LaNiO₃ based superlattice are main interest due to thickness dependent electronic response and tunable magnetic behavior. We investigate the structural, electronic, and magnetic properties of recently experimentally synthesized (LaNiO₃)n/(CaMnO₃)m superlattices with varying LaNiO₃ thickness using density functional theory. The effect of the on-site Coulomb interaction is discussed. In switching from zero to finite U value for Ni atoms, LaNiO₃ shows transitions from half-metallic to metallic character, while spinning ordering changes from paramagnetic to ferromagnetic (FM). For CaMnO₃, U < 3 eV on Mn atoms results in G-type anti-FM spin ordering whereas increasing U value yields FM ordering. In superlattices, metal to insulator transition was achieved with a reduction of LaNiO₃ thickness. The system with one layer of LaNiO₃ yields insulating character. Increasing LaNiO₃ to two layers and above results in the onset of the metallic character with a major contribution from Ni and Mn 3d eg states. Our results for interfacial ferromagnetism, induced Ni magnetic moments and novel antiferromagnetically coupled Ni atoms are consistent with the recent experimental findings. The possible origin of the emergent magnetism is proposed in terms of the exchange interaction and Anderson localization.

Keywords: density functional theory, interfacial magnetism, metal-insulator transition, Ni magnetism.

Procedia PDF Downloads 202
83 Quantitative Seismic Interpretation in the LP3D Concession, Central of the Sirte Basin, Libya

Authors: Tawfig Alghbaili

Abstract:

LP3D Field is located near the center of the Sirt Basin in the Marada Trough approximately 215 km south Marsa Al Braga City. The Marada Trough is bounded on the west by a major fault, which forms the edge of the Beda Platform, while on the east, a bounding fault marks the edge of the Zelten Platform. The main reservoir in the LP3D Field is Upper Paleocene Beda Formation. The Beda Formation is mainly limestone interbedded with shale. The reservoir average thickness is 117.5 feet. To develop a better understanding of the characterization and distribution of the Beda reservoir, quantitative seismic data interpretation has been done, and also, well logs data were analyzed. Six reflectors corresponding to the tops of the Beda, Hagfa Shale, Gir, Kheir Shale, Khalifa Shale, and Zelten Formations were picked and mapped. Special work was done on fault interpretation part because of the complexities of the faults at the structure area. Different attribute analyses were done to build up more understanding of structures lateral extension and to view a clear image of the fault blocks. Time to depth conversion was computed using velocity modeling generated from check shot and sonic data. The simplified stratigraphic cross-section was drawn through the wells A1, A2, A3, and A4-LP3D. The distribution and the thickness variations of the Beda reservoir along the study area had been demonstrating. Petrophysical analysis of wireline logging also was done and Cross plots of some petrophysical parameters are generated to evaluate the lithology of reservoir interval. Structure and Stratigraphic Framework was designed and run to generate different model like faults, facies, and petrophysical models and calculate the reservoir volumetric. This study concluded that the depth structure map of the Beda formation shows the main structure in the area of study, which is north to south faulted anticline. Based on the Beda reservoir models, volumetric for the base case has been calculated and it has STOIIP of 41MMSTB and Recoverable oil of 10MMSTB. Seismic attributes confirm the structure trend and build a better understanding of the fault system in the area.

Keywords: LP3D Field, Beda Formation, reservoir models, Seismic attributes

Procedia PDF Downloads 183
82 Engineered Biopolymers as Novel Sustainable Resin Binder for Wood Composites

Authors: Somaieh Salehpour, Douglas Ireland, Chris Anderson, Charles Markessini

Abstract:

Over the last few years, advancements have been made around improving sustainability for wood composite boards. One of the last and most challenging sustainability hurdles is finding a viable alternative to petroleum-based resin binders. In today’s market, no longer is formaldehyde emission control sufficient to meet the requirements of many architects and end-use consumers. Even the use of highly reactive isocyanates is considered by many as not sustainable enough since these chemicals are manufactured from classical fossil fuel sources. The emergence of biopolymers specifically engineered for usage as wood composite binders has been successfully demonstrated in this paper as a viable option towards a truly renewable wood composite board. Recent technology advancements driven by EcoSynthetix and CHIMAR have exploited the advantages of using an engineered biopolymer. The evidence shows that this renewable technology has the potential to be used as a partial up to full replacement of classical formaldehyde technologies. Numerous trials, both in the lab and at industrial scale, have shown that a renewable binder of the proposed technology can produce a commercially viable board in a traditional industrial setting. The ultimate goal of this work is to provide evidence that a sustainable binder alternative can be used to make a commercial board while at the same time improving the total cost of manufacturing.

Keywords: no added formaldehyde, renewable, biopolymers, sustainable wood composites, engineered biopolymers

Procedia PDF Downloads 377
81 The Complementary Explanations of Institutional and Feminist Perspectives for Female Social Enterprise in Pakistan

Authors: Mohammad Sohail Yunis, Hina Hashim, Alistair R. Anderson

Abstract:

Entrepreneurship is gendered with masculine qualities, yet social enterprise epitomizes caring a feminine quality. However enterprising practices may have little to do with gender. Consequently, the purpose of this paper is to examine practices using two very different explanatory theories, feminist and institutional theory, to establish the role played by gender. This study is situated in KP, the poor but traditional north of Pakistan. Utilising on an interpretive qualitative research approach, this research collected data through in-depth interviews with ten women social entrepreneurs of KP, Pakistan and analyzed using thematic analysis. Empirically, this paper identifies and describes on a number of interesting themes that relate to the women entrepreneurship such as 'women empowerment, patriarchal culture, role of culture and societal norms, religious extremism and terrorism, forced entrepreneurs, change creators, institutional corruption, and security issues'. In addition, female social enterprise in KP is set in a patriarchal, masculine culture, but the practices negotiate institutional obstacles to bring benefits to the disenfranchised. Finally, this research claims to present an original insight into female social entrepreneurship in a developing country context and provide fresh theoretical and empirical perspectives to advance knowledge and scholarship.

Keywords: female social entrepreneurship, institutional theory, feminist theory, developing countries

Procedia PDF Downloads 188
80 Effect of Institution Volume on Mortality and Outcomes in Osteoporotic Hip Fracture Care

Authors: J. Milton, C. Uzoigwe, O. Ayeko, B. Offorha, K. Anderson, R. G. Middleton

Abstract:

Background: We used the UK National Hip Fracture database to determine the effect of institution hip fracture case volume on hip fracture healthcare outcomes in 2019. Using logistic regression for each healthcare outcome, we compared the best performing 50 units with the poorest performing 50 units in order to determine if the unit volume was associated with performance for each particular outcome. Method: We analysed 175 institutions treating a total of 67,673 patients over the course of a year. Results: The number of hip fractures seen per unit ranged between 86 and 952. Larger units tendered to perform health assessments more consistently and mobilise patients more expeditiously post-operatively. Patients treated at large institutions had shorter lengths of stay. With regard to most other outcomes, there was no association between unit case volume and performance, notably compliance with the Best Practice Tariff, time to surgery, proportion of eligible patients undergoing total hip arthroplasty, length of stay, delirium risk, and pressure sore risk assessments. Conclusion: There is no relationship between unit volume and the majority of health care outcomes. It would seem that larger institutions tend to perform better at parameters that are dependent upon personnel numbers. However, where the outcome is contingent, even partially, on physical infrastructure capacity, there was no difference between larger and smaller units.

Keywords: institution volume, mortality, neck of femur fractures, osteoporosis

Procedia PDF Downloads 69
79 Multi-Criteria Evaluation of IDS Architectures in Cloud Computing

Authors: Elmahdi Khalil, Saad Enniari, Mostapha Zbakh

Abstract:

Cloud computing promises to increase innovation and the velocity with witch applications are deployed, all while helping any enterprise meet most IT service needs at a lower total cost of ownership and higher return investment. As the march of cloud continues, it brings both new opportunities and new security challenges. To take advantages of those opportunities while minimizing risks, we think that Intrusion Detection Systems (IDS) integrated in the cloud is one of the best existing solutions nowadays in the field. The concept of intrusion detection was known since past and was first proposed by a well-known researcher named Anderson in 1980's. Since that time IDS's are evolving. Although, several efforts has been made in the area of Intrusion Detection systems for cloud computing environment, many attacks still prevail. Therefore, the work presented in this paper proposes a multi criteria analysis and a comparative study between several IDS architectures designated to work in a cloud computing environments. To achieve this objective, in the first place we will search in the state of the art of several consistent IDS architectures designed to work in a cloud environment. Whereas, in a second step we will establish the criteria that will be useful for the evaluation of architectures. Later, using the approach of multi criteria decision analysis Mac Beth (Measuring Attractiveness by a Categorical Based Evaluation Technique we will evaluate the criteria and assign to each one the appropriate weight according to their importance in the field of IDS architectures in cloud computing. The last step is to evaluate architectures against the criteria and collecting results of the model constructed in the previous steps.

Keywords: cloud computing, cloud security, intrusion detection/prevention system, multi-criteria decision analysis

Procedia PDF Downloads 444
78 Natural and Construction/Demolition Waste Aggregates: A Comparative Study

Authors: Debora C. Mendes, Matthias Eckert, Claudia S. Moço, Helio Martins, Jean-Pierre Gonçalves, Miguel Oliveira, Jose P. Da Silva

Abstract:

Disposal of construction and demolition waste (C&DW) in embankments in the periphery of cities causes both environmental and social problems. To achieve the management of C&DW, a detailed analysis of the properties of these materials should be done. In this work we report a comparative study of the physical, chemical and environmental properties of natural and C&DW aggregates from 25 different origins. Assays were performed according to European Standards. Analysis of heavy metals and organic compounds, namely polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), were performed. Finally, properties of concrete prepared with C&DW aggregates are reported. Physical analyses of C&DW aggregates indicated lower quality properties than natural aggregates, particularly for concrete preparation and unbound layers of road pavements. Chemical properties showed that most samples (80%) meet the values required by European regulations for concrete and unbound layers of road pavements. Analyses of heavy metals Cd, Cr, Cu, Pb, Ni, Mo and Zn in the C&DW leachates showed levels below the limits established by the Council Decision of 19 December 2002. Identification and quantification of PCBs and PAHs indicated that few samples shows the presence of these compounds. The measured levels of PCBs and PAHs are also below the limits. Other compounds identified in the C&DW leachates include phthalates and diphenylmethanol. The characterized C&DW aggregates show lower quality properties than natural aggregates but most samples showed to be environmentally safe. A continuous monitoring of the presence of heavy metals and organic compounds should be made to trial safe C&DW aggregates. C&DW aggregates provide a good economic and environmental alternative to natural aggregates.

Keywords: concrete preparation, construction and demolition waste, heavy metals, organic pollutants

Procedia PDF Downloads 330
77 Woodcast is Ecologically Sound and Tolerated by a Majority of Patients

Authors: R. Hassan, J. Duncombe, E. Darke, A. Dias, K. Anderson, R. G. Middleton

Abstract:

NHS England has set itself the task of delivering a “Net Zero” National Health service by 2040. It is incumbent upon all health care practioners to work towards this goal. Orthopaedic surgeons are no exception. Distal radial fractures are the most common fractures sustained by the adult population. However, studies are shortcoming on individual patient experience. The aim of this study was to assess the patient’s satisfaction and outcomes with woodcast used in the conservative management of distal radius fractures. For all patients managed with woodcast in our unit, we undertook a structured questionnaire that included the Patient Rated Wrist Evaluation (PRWE) score, The EQ-5D-5L score and the pain numerical score at the time of injury and six weeks after. 30 patients were initially managed with woodcast. 80% of patients tolerated woodcast for the full duration of their treatment. Of these, 20% didn’t tolerate woodcast and had their casts removed within 48 hours. Of the remaining, 79.1% were satisfied about woodcast comfort, 66% were very satisfied about woodcast weight, 70% were satisfied with temperature and sweatiness, 62.5% were very satisfied about the smell/odour, and 75% were satisfied about the level of support woodcast provided. During their treatment, 83.3% of patients rated their pain as five or less. For those who completed their treatment in woodcast, none required any further intervention or utilised the open appointment because of ongoing wrist problems. In conclusion, when woodcast is tolerated, patients’ satisfaction and outcome levels were good. However, we acknowledged 20% of patients in our series were not able to tolerate woodacst, Therefore, we suggest a comparison between the widely used synthetic plaster of Paris casting and woodcast to come in order.

Keywords: distal radius fractures, ecological cast, sustainability, woodcast

Procedia PDF Downloads 69
76 Quasiperiodic Magnetic Chains as Spin Filters

Authors: Arunava Chakrabarti

Abstract:

A one-dimensional chain of magnetic atoms, representative of a quantum gas in an artificial quasi-periodic potential and modeled by the well-known Aubry-Andre function and its variants are studied in respect of its capability of working as a spin filter for arbitrary spins. The basic formulation is explained in terms of a perfectly periodic chain first, where it is shown that a definite correlation between the spin S of the incoming particles and the magnetic moment h of the substrate atoms can open up a gap in the energy spectrum. This is crucial for a spin filtering action. The simple one-dimensional chain is shown to be equivalent to a 2S+1 strand ladder network. This equivalence is exploited to work out the condition for the opening of gaps. The formulation is then applied for a one-dimensional chain with quasi-periodic variation in the site potentials, the magnetic moments and their orientations following an Aubry-Andre modulation and its variants. In addition, we show that a certain correlation between the system parameters can generate absolutely continuous bands in such systems populated by Bloch like extended wave functions only, signaling the possibility of a metal-insulator transition. This is a case of correlated disorder (a deterministic one), and the results provide a non-trivial variation to the famous Anderson localization problem. We have worked within a tight binding formalism and have presented explicit results for the spin half, spin one, three halves and spin five half particles incident on the magnetic chain to explain our scheme and the central results.

Keywords: Aubry-Andre model, correlated disorder, localization, spin filter

Procedia PDF Downloads 328
75 Woodcast Is Ecologically Sound and Tolerated by Majority of Patients

Authors: R. Hassan, J. Duncombe, E. Darke, A. Dias, K. Anderson, R. G. Middleton

Abstract:

Background: NHS England has set itself the task of delivering a “Net Zero” National Health service by 2040. It is incumbent upon all health care practioners to work towards this goal. Orthopaedic surgeons are no exception. Distal radial fractures are the most common fractures sustained by the adult population. However, studiesare shortcoming on individual patient experience. The aim of this study was to assess the patient’ssatisfaction and outcomes with woodcast used in the conservative management of distal radius fractures. Methods: For all patients managed with woodcast in our unit, we undertook a structured questionnairethat included the Patient Rated Wrist Evaluation (PRWE) score, The EQ-5D-5L score, and the pain numerical score at the time of injury and six weeks after. Results: 30 patients were initially managed with woodcast.80% of patients tolerated woodcast for the full duration of their treatment. Of these, 20% didn’t tolerate woodcast and had their casts removed within 48 hours. Of the remaining, 79.1% were satisfied about woodcast comfort, 66% were very satisfied about woodcast weight, 70% were satisfied with temperature and sweatiness, 62.5% were very satisfied about the smell/odour, and 75% were satisfied about the level of support woodcast provided. During their treatment, 83.3% of patients rated their pain as five or less. Conclusion: For those who completed their treatment in woodcast, none required any further intervention or utilised the open appointment because of ongoing wrist problems. In conclusion, when woodcast is tolerated, patients’ satisfaction and outcome levels were good. However, we acknowledged 20% of patients in our series were not able to tolerate woodacst, Therefore, we suggest a comparison between the widely used synthetic plaster of Pariscasting and woodcast to come in order.

Keywords: distal radius fractures, ecological cast, sustainability, woodcast

Procedia PDF Downloads 66
74 Knowledge, Attitude and Practice Towards the Attendance of Antenatal Care Services at Mukono General Hospital

Authors: Nabaweesi Josephine, Namwanje Regina Germina

Abstract:

Antenatal care is referred to as the totality of care given to pregnant women from conception to delivery from a certified health care setting. A number of 8 contacts is recommended throughout pregnancy, according to WHO, 2016. Antenatal services are free in Uganda courtesy of the government of Uganda, though attendance is still very low, which has continued to cause maternal and infant mortality and morbidity from preventable causes. Early booking has an advantage for proper pregnancy information sharing and pregnancy monitoring. The purpose of this study was to determine pregnant women's knowledge, attitudes, and practices towards attendance of antenatal care at Mukono General Hospital. A sample of 60 pregnant women was used, and a descriptive quantitative design was employed. Data was collected using a structured questionnaire consisting of questions about socio-demographic factors, knowledge, attitude, and practice, and this was affected using the structured interview method. Pregnant women had good practice at 90.2%, a positive attitude of 94.6%, and slightly less knowledge of 66.7%. Only 12% were knowledgeable about the number of antenatal care visits recommended, 45% had knowledge about when to initiate first antenatal care visit, and 79% had a positive attitude towards the early booking. We recommend that pregnant women are given all the necessary information regarding antenatal care with special emphasis on the recommended number of visits and when to initiate their first visit and encourage early booking in order to achieve the 8 contacts WHO policy for antenatal care since when we increase knowledge, we increase antenatal care utilization according to Anderson's behavioral model.

Keywords: ANC- antenatal care, contacts, mortality, morbidity

Procedia PDF Downloads 80
73 Deployment of Beyond 4G Wireless Communication Networks with Carrier Aggregation

Authors: Bahram Khan, Anderson Rocha Ramos, Rui R. Paulo, Fernando J. Velez

Abstract:

With the growing demand for a new blend of applications, the users dependency on the internet is increasing day by day. Mobile internet users are giving more attention to their own experiences, especially in terms of communication reliability, high data rates and service stability on move. This increase in the demand is causing saturation of existing radio frequency bands. To address these challenges, researchers are investigating the best approaches, Carrier Aggregation (CA) is one of the newest innovations, which seems to fulfill the demands of the future spectrum, also CA is one the most important feature for Long Term Evolution - Advanced (LTE-Advanced). For this purpose to get the upcoming International Mobile Telecommunication Advanced (IMT-Advanced) mobile requirements (1 Gb/s peak data rate), the CA scheme is presented by 3GPP, which would sustain a high data rate using widespread frequency bandwidth up to 100 MHz. Technical issues such as aggregation structure, its implementations, deployment scenarios, control signal techniques, and challenges for CA technique in LTE-Advanced, with consideration of backward compatibility, are highlighted in this paper. Also, performance evaluation in macro-cellular scenarios through a simulation approach is presented, which shows the benefits of applying CA, low-complexity multi-band schedulers in service quality, system capacity enhancement and concluded that enhanced multi-band scheduler is less complex than the general multi-band scheduler, which performs better for a cell radius longer than 1800 m (and a PLR threshold of 2%).

Keywords: component carrier, carrier aggregation, LTE-advanced, scheduling

Procedia PDF Downloads 160
72 Soil Salinity from Wastewater Irrigation in Urban Greenery

Authors: H. Nouri, S. Chavoshi Borujeni, S. Anderson, S. Beecham, P. Sutton

Abstract:

The potential risk of salt leaching through wastewater irrigation is of concern for most local governments and city councils. Despite the necessity of salinity monitoring and management in urban greenery, most attention has been on agricultural fields. This study was defined to investigate the capability and feasibility of monitoring and predicting soil salinity using near sensing and remote sensing approaches using EM38 surveys, and high-resolution multispectral image of WorldView3. Veale Gardens within the Adelaide Parklands was selected as the experimental site. The results of the near sensing investigation were validated by testing soil salinity samples in the laboratory. Over 30 band combinations forming salinity indices were tested using image processing techniques. The outcomes of the remote sensing and near sensing approaches were compared to examine whether remotely sensed salinity indicators could map and predict the spatial variation of soil salinity through a potential statistical model. Statistical analysis was undertaken using the Stata 13 statistical package on over 52,000 points. Several regression models were fitted to the data, and the mixed effect modelling was selected the most appropriate one as it takes to account the systematic observation-specific unobserved heterogeneity. Results showed that SAVI (Soil Adjusted Vegetation Index) was the only salinity index that could be considered as a predictor for soil salinity but further investigation is needed. However, near sensing was found as a rapid, practical and realistically accurate approach for salinity mapping of heterogeneous urban vegetation.

Keywords: WorldView3, remote sensing, EM38, near sensing, urban green spaces, green smart cities

Procedia PDF Downloads 133
71 Prospects in Development of Ecofriendly Biopesticides in Management of Postharvest Fungal Deterioration of Cassava (Manihot esculenta Crantz)

Authors: Anderson Chidi Amadioha, Promise Chidi Kenkwo, A. A. Markson

Abstract:

Cassava (Manihot esculenta Crantz) is an important food and cash crop that provide cheap source of carbohydrate for food, feed and raw material for industries hence a commodity for feature economic development of developing countries. Despite the importance, its production potentials is undermined by disease agents that greatly reduce yield and render it unfit for human consumption and industrial use. Pathogenicity tests on fungal isolates from infected cassava revealed Aspergillus flavus, Rhizopus stolonifer, Aspergillus niger, and Trichodderma viride as rot-causing organisms. Water and ethanol extracts of Piper guineense, Ocimum graticimum, Cassia alata, and Tagetes erecta at 50% concentration significantly inhibited the radial growth of the pathogens in vitro and their development and spread in vivo. Low cassava rot incidence and severity was recorded when the extracts were applied before than after spray inoculating with spore suspension (1x105 spores/ml of distilled water) of the pathogenic organisms. The plant materials are readily available, and their extracts are biodegradable and cost effective. The fungitoxic potentials of extracts of these plant materials could be exploited as potent biopesticides in the management of postharvest fungal deterioration of cassava especially in developing countries where synthetic fungicides are not only scarce but also expensive for resource poor farmers who produce over 95% of the food consumed.

Keywords: cassava, biopesticides, in vitro, in vivo, pathogens, plant extracts

Procedia PDF Downloads 150
70 Role of Vocational Education and Training in Economic Excellence and Social Inclusion

Authors: Muhammad Ali Asadullah, Zafarullah Amir

Abstract:

In recent years, Vocational Education and Training (VET) has been under discussion by the academic researchers and remained in focus in the political grounds. Due to potential contribution of VET, the World Bank and United Nations Educational, Scientific and Cultural Organization (UNESCO) support vocational education to reduce poverty, enhance economic growth and increase competitiveness. This paper examines the impact of Vocational Education and Training on the Economic Growth and Social Inclusion with direct and mediation effect of Social Inclusion. The basic purpose of this study is to assess economic pay-offs as a result of long term investments in VET. Based on the review of Anderson Nilsson, initially we explored the increasing or decreasing trend in investment on VET. Further, the study explores that the countries which invest more on VET, tend to get more economic growth and are socially more ‘inclusive’. It is a longitudinal / panel data study with 12 years of registered data which involves 24 OECD countries. The results of the study indicate the VET has positive association with Social Inclusion and Economic Growth. Further, there is also a positive association of VET and Economic Growth through mediation of Social Inclusion. The current study considers not only issue and challenges in developing VET systems but also contributes to develop the theoretical framework for considering how VET can directly and indirectly improve economic growth and social inclusion. A wider appreciation of how VET’s benefits operate may influence a country’s decisions to invest in it. If policy makers increase investment on VET, the result would be positive in Economic Growth and Social Inclusion. It is also recommended that the same OECD model may be implemented in developing countries like Pakistan.

Keywords: Vocational Education and Training (VET), Social Inclusion, Economic Growth, OECD countries

Procedia PDF Downloads 285
69 Hip Resurfacing Makes for Easier Surgery with Better Functional Outcomes at Time of Revision: A Case Controlled Study

Authors: O. O. Onafowokan, K. Anderson, M. R. Norton, R. G. Middleton

Abstract:

Revision total hip arthroplasty (THA) is known to be a challenging procedure with potential for poor outcomes. Due to its lack of metaphyseal encroachment, hip resurfacing arthroplasty (HRA) is classified as a bone conserving procedure. Although the literature postulates that this is an advantage at time of revision surgery, there is no evidence to either support or refute this claim. We identified 129 hips that had undergone HRA and 129 controls undergoing first revision THA. We recorded the clinical assessment and survivorship of implants in a multi-surgeon, single centre, retrospective case control series for both arms. These were matched for age and sex. Data collected included demographics, indications for surgery, Oxford Hip Score (OHS), length of surgery, length of hospital stay, blood transfusion, implant complexity and further surgical procedures. Significance was taken as p < 0.05. Mean follow up was 7.5 years (1 to 15). There was a significant 6 point difference in postoperative OHS in favour of the revision resurfacing group (p=0.0001). The revision HRA group recorded 48 minutes less length of surgery (p<0.0001), 2 days less in length of hospital stay (p=0.018), a reduced need for blood transfusion (p=0.0001), a need for less complexity in revision implants (p=0.001) and a reduced probability of further surgery being required (P=0.003). Whilst we acknowledge the limitations of this study our results suggest that, in contrast to THA, the bone conservation element of HRA may make for a less traumatic revision procedure with better functional outcomes. Use of HRA has seen a dramatic decline as a result of concerns regarding metallosis. However, this information remains of relevance when counselling young active patients about their arthroplasty options and may become pertinent in the future if the promise of ceramic hip resurfacing is ever realized.

Keywords: hip resurfacing, metallosis, revision surgery, total hip arthroplasty

Procedia PDF Downloads 62
68 Some Considerations about the Theory of Spatial-Motor Thinking Applied to a Traditional Fife Band in Brazil

Authors: Murilo G. Mendes

Abstract:

This text presents part of the results presented in the Ph.D. thesis that has used John Baily's theory and method as well as its ethnographic application in the context of the fife flutes of the Banda Cabaçal dos Irmãos Aniceto in the state of Ceará, northeast of Brazil. John Baily is a British ethnomusicologist dedicated to studying the relationships between music, musical gesture, and embodied cognition. His methodology became a useful tool to highlight historical-social aspects present in the group's instrumental music. Remaining indigenous and illiterate, these musicians played and transmitted their music from generation to generation, for almost two hundred years, without any nomenclature or systematization of the fingering performed on the flute. In other words, his music, free from any theorization, is learned, felt, perceived, and processed directly through hearing and through the relationship between the instrument's motor skills and its sound result. For this reason, Baily's assumptions became fundamental in the analysis processes. As the author's methodology recommends, classes were held with the natives and provided technical musical learning and some important concepts. Then, transcriptions and analyses of musical aspects were made from patterns of movement on the instrument incorporated by repetitions and/or by the intrinsic facility of the instrument. As a result, it was discovered how the group reconciled its indigenous origins with the demand requested by the public power and the interests of the local financial elite from the mid-twentieth century. The article is structured from the cultural context of the group, where local historical and social aspects influence the social and musical practices of the group. Then, will be present the methodological conceptions of John Baily and, finally, their application in the music of the Irmãos Aniceto. The conclusion points to the good results of identifying, through this methodology and analysis, approximations between discourse, historical-social factors, and musical text. Still, questions are raised about its application in other contexts.

Keywords: Banda Cabaçal dos Irmãos Aniceto, John Baily, pífano, spatial-motor thinking

Procedia PDF Downloads 103
67 Cost Benefit Analysis: Evaluation among the Millimetre Wavebands and SHF Bands of Small Cell 5G Networks

Authors: Emanuel Teixeira, Anderson Ramos, Marisa Lourenço, Fernando J. Velez, Jon M. Peha

Abstract:

This article discusses the benefit cost analysis aspects of millimetre wavebands (mmWaves) and Super High Frequency (SHF). The devaluation along the distance of the carrier-to-noise-plus-interference ratio with the coverage distance is assessed by considering two different path loss models, the two-slope urban micro Line-of-Sight (UMiLoS) for the SHF band and the modified Friis propagation model, for frequencies above 24 GHz. The equivalent supported throughput is estimated at the 5.62, 28, 38, 60 and 73 GHz frequency bands and the influence of carrier-to-noise-plus-interference ratio in the radio and network optimization process is explored. Mostly owing to the lessening caused by the behaviour of the two-slope propagation model for SHF band, the supported throughput at this band is higher than at the millimetre wavebands only for the longest cell lengths. The benefit cost analysis of these pico-cellular networks was analysed for regular cellular topologies, by considering the unlicensed spectrum. For shortest distances, we can distinguish an optimal of the revenue in percentage terms for values of the cell length, R ≈ 10 m for the millimeter wavebands and for longest distances an optimal of the revenue can be observed at R ≈ 550 m for the 5.62 GHz. It is possible to observe that, for the 5.62 GHz band, the profit is slightly inferior than for millimetre wavebands, for the shortest Rs, and starts to increase for cell lengths approximately equal to the ratio between the break-point distance and the co-channel reuse factor, achieving a maximum for values of R approximately equal to 550 m.

Keywords: millimetre wavebands, SHF band, SINR, cost benefit analysis, 5G

Procedia PDF Downloads 121
66 Physical, Chemical and Environmental Properties of Natural and Construction/Demolition Recycled Aggregates

Authors: Débora C. Mendes, Matthias Eckert, Cláudia S. Moço, Hélio Martins, Jean-Pierre P. Gonçalves, Miguel Oliveira, José P. Da Silva

Abstract:

Uncontrolled disposal of construction and demolition waste (C & DW) in embankments in the periphery of cities causes both environmental and social problems, namely erosion, deforestation, water contamination and human conflicts. One of the milestones of EU Horizon 2020 Programme is the management of waste as a resource. To achieve this purpose for C & DW, a detailed analysis of the properties of these materials should be done. In this work we report the physical, chemical and environmental properties of C & DW aggregates from 25 different origins. The results are compared with those of common natural aggregates used in construction. Assays were performed according to European Standards. Additional analysis of heavy metals and organic compounds such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), were performed to evaluate their environmental impact. Finally, properties of concrete prepared with C & DW aggregates are also reported. Physical analyses of C & DW aggregates indicated lower quality properties than natural aggregates, particularly for concrete preparation and unbound layers of road pavements. Chemical properties showed that most samples (80%) meet the values required by European regulations for concrete and unbound layers of road pavements. Analyses of heavy metals Cd, Cr, Cu, Pb, Ni, Mo and Zn in the C&DW leachates showed levels below the limits established by the Council Decision of 19 December 2002. Identification and quantification of PCBs and PAHs indicated that few samples shows the presence of these compounds. The measured levels of PCBs and PAHs are also below the limits. Other compounds identified in the C&DW leachates include phthalates and diphenylmethanol. In conclusion, the characterized C&DW aggregates show lower quality properties than natural aggregates but most samples showed to be environmentally safe. A continuous monitoring of the presence of heavy metals and organic compounds should be made to trial safe C&DW aggregates. C&DW aggregates provide a good economic and environmental alternative to natural aggregates.

Keywords: concrete preparation, construction and demolition waste, heavy metals, organic pollutants

Procedia PDF Downloads 324
65 Lateral Sural Artery Perforators: A Cadaveric Dissection Study to Assess Perforator Surface Anatomy Variability and Average Pedicle Length for Flap Reconstruction

Authors: L. Sun, O. Bloom, K. Anderson

Abstract:

The medial and lateral sural artery perforator flaps (MSAP and LSAP, respectively) are two recently described flaps that are less commonly used in lower limb trauma reconstructive surgeries compared to flaps such as the anterolateral thigh (ALT) flap or the gastrocnemius flap. The LSAP flap has several theoretical benefits over the MSAP, including the ability to be sensate and being more easily manoeuvred into position as a local flap for coverage of lateral knee or leg defects. It is less commonly used in part due to a lack of documented studies of the anatomical reliability of the perforator, and an unquantified average length of the pedicle used for microsurgical anastomosis (if used as a free flap) or flap rotation (if used as a pedicled flap). It has been shown to have significantly lower donor site morbidity compared to other flaps such as the ALT, due to the decreased need for intramuscular dissection and resulting in less muscle loss at the donor site. 11 cadaveric lower limbs were dissected, with a mean of 1.6 perforators per leg, with an average pedicle length of 45mm to the sural artery and 70mm to the popliteal artery. While the majority of perforating arteries lay close to the midline (average of 19mm lateral to the midline), there were patients whose artery was significantly lateral and would have been likely injured by the initial incision during an operation. Adding to the literature base of documented LSAP dissections provides a greater understanding of the anatomical basis of these perforator flaps, and the authors hope this will establish them as a more commonly used and discussed option when managing complicated lower limb trauma requiring soft tissue reconstruction.

Keywords: cadaveric, dissection, lateral, perforator flap, sural artery, surface anatomy

Procedia PDF Downloads 134
64 Predicting High-Risk Endometrioid Endometrial Carcinomas Using Protein Markers

Authors: Yuexin Liu, Gordon B. Mills, Russell R. Broaddus, John N. Weinstein

Abstract:

The lethality of endometrioid endometrial cancer (EEC) is primarily attributable to the high-stage diseases. However, there are no available biomarkers that predict EEC patient staging at the time of diagnosis. We aim to develop a predictive scheme to help in this regards. Using reverse-phase protein array expression profiles for 210 EEC cases from The Cancer Genome Atlas (TCGA), we constructed a Protein Scoring of EEC Staging (PSES) scheme for surgical stage prediction. We validated and evaluated its diagnostic potential in an independent cohort of 184 EEC cases obtained at MD Anderson Cancer Center (MDACC) using receiver operating characteristic curve analyses. Kaplan-Meier survival analysis was used to examine the association of PSES score with patient outcome, and Ingenuity pathway analysis was used to identify relevant signaling pathways. Two-sided statistical tests were used. PSES robustly distinguished high- from low-stage tumors in the TCGA cohort (area under the ROC curve [AUC]=0.74; 95% confidence interval [CI], 0.68 to 0.82) and in the validation cohort (AUC=0.67; 95% CI, 0.58 to 0.76). Even among grade 1 or 2 tumors, PSES was significantly higher in high- than in low-stage tumors in both the TCGA (P = 0.005) and MDACC (P = 0.006) cohorts. Patients with positive PSES score had significantly shorter progression-free survival than those with negative PSES in the TCGA (hazard ratio [HR], 2.033; 95% CI, 1.031 to 3.809; P = 0.04) and validation (HR, 3.306; 95% CI, 1.836 to 9.436; P = 0.0007) cohorts. The ErbB signaling pathway was most significantly enriched in the PSES proteins and downregulated in high-stage tumors. PSES may provide clinically useful prediction of high-risk tumors and offer new insights into tumor biology in EEC.

Keywords: endometrial carcinoma, protein, protein scoring of EEC staging (PSES), stage

Procedia PDF Downloads 198
63 Comparison of Adsorbents for Ammonia Removal from Mining Wastewater

Authors: F. Al-Sheikh, C. Moralejo, M. Pritzker, W. A. Anderson, A. Elkamel

Abstract:

Ammonia in mining wastewater is a significant problem, and treatment can be especially difficult in cold climates where biological treatment is not feasible. An adsorption process is one of the alternative processes that can be used to reduce ammonia concentrations to acceptable limits, and therefore a LEWATIT resin strongly acidic H+ form ion exchange resin and a Bowie Chabazite Na form AZLB-Na zeolite were tested to assess their effectiveness. For these adsorption tests, two packed bed columns (a mini-column constructed from a 32-cm long x 1-cm diameter piece of glass tubing, and a 60-cm long x 2.5-cm diameter Ace Glass chromatography column) were used containing varying quantities of the adsorbents. A mining wastewater with ammonia concentrations of 22.7 mg/L was fed through the columns at controlled flowrates. In the experimental work, maximum capacities of the LEWATIT ion exchange resin were 0.438, 0.448, and 1.472 mg/g for 3, 6, and 9 g respectively in a mini column and 1.739 mg/g for 141.5 g in a larger Ace column while the capacities for the AZLB-Na zeolite were 0.424, and 0.784 mg/g for 3, and 6 g respectively in the mini column and 1.1636 mg/g for 38.5 g in the Ace column. In the theoretical work, Thomas, Adams-Bohart, and Yoon-Nelson models were constructed to describe a breakthrough curve of the adsorption process and find the constants of the above-mentioned models. In the regeneration tests, 5% hydrochloric acid, HCl (v/v) and 10% sodium hydroxide, NaOH (w/v) were used to regenerate the LEWATIT resin and AZLB-Na zeolite with 44 and 63.8% recovery, respectively. In conclusion, continuous flow adsorption using a LEWATIT ion exchange resin and an AZLB-Na zeolite is efficient when using a co-flow technique for removal of the ammonia from wastewater. Thomas, Adams-Bohart, and Yoon-Nelson models satisfactorily fit the data with R2 closer to 1 in all cases.

Keywords: AZLB-Na zeolite, continuous adsorption, Lewatit resin, models, regeneration

Procedia PDF Downloads 351
62 Analysis of Genic Expression of Honey Bees Exposed to Sublethal Pesticides Doses Using the Transcriptome Technique

Authors: Ricardo de Oliveira Orsi, Aline Astolfi, Daniel Diego Mendes, Isabella Cristina de Castro Lippi, Jaine da Luz Scheffer, Yan Souza Lima, Juliana Lunardi, Giovanna do Padro Ribeiro, Samir Moura Kadri

Abstract:

NECTAR Brazilian group (Center of Education, Science, and Technology in Rational Beekeeping) conducted studies on the pesticides honey bees effects using the transcriptome sequencing (RNA-Seq) analyzes for gene expression studies. In this way, we analyzed the effects of Pyraclostrobin and Fipronil on the honey bees with 21 old-days (forager) in laboratory conditions. For this, frames containing sealed brood were removed from the beehives and maintenance on the stove (32°C and 75% humidity) until the bees were born. So, newly emerged workers were marked on the pronotum with a non-toxic pen and reintroduced into their original hives. After 21 days, 120 marked bees were collected with an entomological forces and immediately stored in Petri dishes, perforated to ensure ventilation, and kept fasted for 3 hours. These honeybees were exposed to food contaminated or not with the sublethal dose of Pyraclostrobin (850 ppb/bee) or Fipronil (2.5 ppb/bee). After four hours of exposure, 15 bees from each treatment were referred to transcriptome analysis. Total RNA analysis was extracted from the brain pools (03 brains per pool) using the TRIzol® reagent protocol according to the manufacturer's instructions. cDNA libraries were constructed, and the FASTQC program was used to check adapter content and assess the quality of raw reads. Differential expression analysis was performed with the DESeq2 package. Genes that had an adjusted value of less than 0.05 were considered to be significantly up-regulated. Regarding the Pyraclostrobin, alterations were observed in the pattern of 17 gene related to of antioxidant system, cellular respiration, glucose metabolism, and regulation of juvenile hormone and the hormone insulin. Glyphosate altered the 10 gene related to the digestive system, exoskeleton composition, vitamin E transport, and antioxidant system. The results indicate that the necessity of studies using the sublethal doses to evaluate the pesticides uses and risks on crops and its effects on the honey bees.

Keywords: beekeeping, honey bees, pesticides, transcriptome

Procedia PDF Downloads 105
61 In vitro Skin Model for Enhanced Testing of Antimicrobial Textiles

Authors: Steven Arcidiacono, Robert Stote, Erin Anderson, Molly Richards

Abstract:

There are numerous standard test methods for antimicrobial textiles that measure activity against specific microorganisms. However, many times these results do not translate to the performance of treated textiles when worn by individuals. Standard test methods apply a single target organism grown under optimal conditions to a textile, then recover the organism to quantitate and determine activity; this does not reflect the actual performance environment that consists of polymicrobial communities in less than optimal conditions or interaction of the textile with the skin substrate. Here we propose the development of in vitro skin model method to bridge the gap between lab testing and wear studies. The model will consist of a defined polymicrobial community of 5-7 commensal microbes simulating the skin microbiome, seeded onto a solid tissue platform to represent the skin. The protocol would entail adding a non-commensal test organism of interest to the defined community and applying a textile sample to the solid substrate. Following incubation, the textile would be removed and the organisms recovered, which would then be quantitated to determine antimicrobial activity. Important parameters to consider include identification and assembly of the defined polymicrobial community, growth conditions to allow the establishment of a stable community, and choice of skin surrogate. This model could answer the following questions: 1) is the treated textile effective against the target organism? 2) How is the defined community affected? And 3) does the textile cause unwanted effects toward the skin simulant? The proposed model would determine activity under conditions comparable to the intended application and provide expanded knowledge relative to current test methods.

Keywords: antimicrobial textiles, defined polymicrobial community, in vitro skin model, skin microbiome

Procedia PDF Downloads 114
60 The Human Process of Trust in Automated Decisions and Algorithmic Explainability as a Fundamental Right in the Exercise of Brazilian Citizenship

Authors: Paloma Mendes Saldanha

Abstract:

Access to information is a prerequisite for democracy while also guiding the material construction of fundamental rights. The exercise of citizenship requires knowing, understanding, questioning, advocating for, and securing rights and responsibilities. In other words, it goes beyond mere active electoral participation and materializes through awareness and the struggle for rights and responsibilities in the various spaces occupied by the population in their daily lives. In times of hyper-cultural connectivity, active citizenship is shaped through ethical trust processes, most often established between humans and algorithms. Automated decisions, so prevalent in various everyday situations, such as purchase preference predictions, virtual voice assistants, reduction of accidents in autonomous vehicles, content removal, resume selection, etc., have already found their place as a normalized discourse that sometimes does not reveal or make clear what violations of fundamental rights may occur when algorithmic explainability is lacking. In other words, technological and market development promotes a normalization for the use of automated decisions while silencing possible restrictions and/or breaches of rights through a culturally modeled, unethical, and unexplained trust process, which hinders the possibility of the right to a healthy, transparent, and complete exercise of citizenship. In this context, the article aims to identify the violations caused by the absence of algorithmic explainability in the exercise of citizenship through the construction of an unethical and silent trust process between humans and algorithms in automated decisions. As a result, it is expected to find violations of constitutionally protected rights such as privacy, data protection, and transparency, as well as the stipulation of algorithmic explainability as a fundamental right in the exercise of Brazilian citizenship in the era of virtualization, facing a threefold foundation called trust: culture, rules, and systems. To do so, the author will use a bibliographic review in the legal and information technology fields, as well as the analysis of legal and official documents, including national documents such as the Brazilian Federal Constitution, as well as international guidelines and resolutions that address the topic in a specific and necessary manner for appropriate regulation based on a sustainable trust process for a hyperconnected world.

Keywords: artificial intelligence, ethics, citizenship, trust

Procedia PDF Downloads 37
59 Benchmarking Machine Learning Approaches for Forecasting Hotel Revenue

Authors: Rachel Y. Zhang, Christopher K. Anderson

Abstract:

A critical aspect of revenue management is a firm’s ability to predict demand as a function of price. Historically hotels have used simple time series models (regression and/or pick-up based models) owing to the complexities of trying to build casual models of demands. Machine learning approaches are slowly attracting attention owing to their flexibility in modeling relationships. This study provides an overview of approaches to forecasting hospitality demand – focusing on the opportunities created by machine learning approaches, including K-Nearest-Neighbors, Support vector machine, Regression Tree, and Artificial Neural Network algorithms. The out-of-sample performances of above approaches to forecasting hotel demand are illustrated by using a proprietary sample of the market level (24 properties) transactional data for Las Vegas NV. Causal predictive models can be built and evaluated owing to the availability of market level (versus firm level) data. This research also compares and contrast model accuracy of firm-level models (i.e. predictive models for hotel A only using hotel A’s data) to models using market level data (prices, review scores, location, chain scale, etc… for all hotels within the market). The prospected models will be valuable for hotel revenue prediction given the basic characters of a hotel property or can be applied in performance evaluation for an existed hotel. The findings will unveil the features that play key roles in a hotel’s revenue performance, which would have considerable potential usefulness in both revenue prediction and evaluation.

Keywords: hotel revenue, k-nearest-neighbors, machine learning, neural network, prediction model, regression tree, support vector machine

Procedia PDF Downloads 108
58 Interpersonal Variation of Salivary Microbiota Using Denaturing Gradient Gel Electrophoresis

Authors: Manjula Weerasekera, Chris Sissons, Lisa Wong, Sally Anderson, Ann Holmes, Richard Cannon

Abstract:

The aim of this study was to characterize bacterial population and yeasts in saliva by Polymerase chain reaction followed by denaturing gradient gel electrophoresis (PCR-DGGE) and measure yeast levels by culture. PCR-DGGE was performed to identify oral bacteria and yeasts in 24 saliva samples. DNA was extracted and used to generate DNA amplicons of the V2–V3 hypervariable region of the bacterial 16S rDNA gene using PCR. Further universal primers targeting the large subunit rDNA gene (25S-28S) of fungi were used to amplify yeasts present in human saliva. Resulting PCR products were subjected to denaturing gradient gel electrophoresis using Universal mutation detection system. DGGE bands were extracted and sequenced using Sanger method. A potential relationship was evaluated between groups of bacteria identified by cluster analysis of DGGE fingerprints with the yeast levels and with their diversity. Significant interpersonal variation of salivary microbiome was observed. Cluster and principal component analysis of the bacterial DGGE patterns yielded three significant major clusters, and outliers. Seventeen of the 24 (71%) saliva samples were yeast positive going up to 10³ cfu/mL. Predominately, C. albicans, and six other species of yeast were detected. The presence, amount and species of yeast showed no clear relationship to the bacterial clusters. Microbial community in saliva showed a significant variation between individuals. A lack of association between yeasts and the bacterial fingerprints in saliva suggests the significant ecological person-specific independence in highly complex oral biofilm systems under normal oral conditions.

Keywords: bacteria, denaturing gradient gel electrophoresis, oral biofilm, yeasts

Procedia PDF Downloads 200
57 Comparison of FNTD and OSLD Detectors' Responses to Light Ion Beams Using Monte Carlo Simulations and Exprimental Data

Authors: M. R. Akbari, H. Yousefnia, A. Ghasemi

Abstract:

Al2O3:C,Mg fluorescent nuclear track detector (FNTD) and Al2O3:C optically stimulated luminescence detector (OSLD) are becoming two of the applied detectors in ion dosimetry. Therefore, the response of these detectors to hadron beams is highly of interest in radiation therapy (RT) using ion beams. In this study, these detectors' responses to proton and Helium-4 ion beams were compared using Monte Carlo simulations. The calculated data for proton beams were compared with Markus ionization chamber (IC) measurement (in water phantom) from M.D. Anderson proton therapy center. Monte Carlo simulations were performed via the FLUKA code (version 2011.2-17). The detectors were modeled in cylindrical shape at various depths of the water phantom without shading each other for obtaining relative depth dose in the phantom. Mono-energetic parallel ion beams in different incident energies (100 MeV/n to 250 MeV/n) were collided perpendicularly on the phantom surface. For proton beams, the results showed that the simulated detectors have over response relative to IC measurements in water phantom. In all cases, there were good agreements between simulated ion ranges in the water with calculated and experimental results reported by the literature. For proton, maximum peak to entrance dose ratio in the simulated water phantom was 4.3 compared with about 3 obtained from IC measurements. For He-4 ion beams, maximum peak to entrance ratio calculated by both detectors was less than 3.6 in all energies. Generally, it can be said that FLUKA is a good tool to calculate Al2O3:C,Mg FNTD and Al2O3:C OSLD detectors responses to therapeutic proton and He-4 ion beams. It can also calculate proton and He-4 ion ranges with a reasonable accuracy.

Keywords: comparison, FNTD and OSLD detectors response, light ion beams, Monte Carlo simulations

Procedia PDF Downloads 313