Search results for: frequency selective surface
1379 2D and 3D Breast Cancer Cells Behave Differently to the Applied Free Palbociclib or the Palbociclib-Loaded Nanoparticles
Authors: Maryam Parsian, Pelin Mutlu, Ufuk Gunduz
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Two-dimensional cell culture affords simplicity and low cost, but it has serious limitations; lacking cell-cell and cell-matrix interactions that are present in tissues. Cancer cells grown in 3D culture systems have distinct phenotypes of adhesion, growth, migration, invasion as well as profiles of gene and protein expression. These interactions cause the 3D-cultured cells to acquire morphological and cellular characteristics relevant to in vivo tumors. Palbociclib is a chemotherapeutic agent for the treatment of ER-positive and HER-negative metastatic breast cancer. Poly-amidoamine (PAMAM) dendrimer is a well-defined, special three-dimensional structure and has a multivalent surface and internal cavities that can play an essential role in drug delivery systems. In this study, palbociclib is loaded onto the magnetic PAMAM dendrimer. Hanging droplet method was used in order to form 3D spheroids. The possible toxic effects of both free drug and drug loaded nanoparticles were evaluated in 2D and 3D MCF-7, MD-MB-231 and SKBR-3 breast cancer cell culture models by performing MTT cell viability and Alamar Blue assays. MTT analysis was performed with six different doses from 1000 µg/ml to 25 µg/ml. Drug unloaded PAMAM dendrimer did not demonstrate significant toxicity on all breast cancer cell lines. The results showed that 3D spheroids are clearly less sensitive than 2D cell cultures to free palbociclib. Also, palbociclib loaded PAMAM dendrimers showed more toxic effect than free palbociclib in all cell lines at 2D and 3D cultures. The results suggest that the traditional cell culture method (2D) is insufficient for mimicking the actual tumor tissue. The response of the cancer cells to anticancer drugs is different in the 2D and 3D culture conditions. This study showed that breast cancer cells are more resistant to free palbociclib in 3D cultures than in 2D cultures. However, nanoparticle loaded drugs can be more cytotoxic when compared to free drug.Keywords: 2D and 3D cell culture, breast cancer, palbociclibe, PAMAM magnetic nanoparticles
Procedia PDF Downloads 1491378 Historical Development of Negative Emotive Intensifiers in Hungarian
Authors: Martina Katalin Szabó, Bernadett Lipóczi, Csenge Guba, István Uveges
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In this study, an exhaustive analysis was carried out about the historical development of negative emotive intensifiers in the Hungarian language via NLP methods. Intensifiers are linguistic elements which modify or reinforce a variable character in the lexical unit they apply to. Therefore, intensifiers appear with other lexical items, such as adverbs, adjectives, verbs, infrequently with nouns. Due to the complexity of this phenomenon (set of sociolinguistic, semantic, and historical aspects), there are many lexical items which can operate as intensifiers. The group of intensifiers are admittedly one of the most rapidly changing elements in the language. From a linguistic point of view, particularly interesting are a special group of intensifiers, the so-called negative emotive intensifiers, that, on their own, without context, have semantic content that can be associated with negative emotion, but in particular cases, they may function as intensifiers (e.g.borzasztóanjó ’awfully good’, which means ’excellent’). Despite their special semantic features, negative emotive intensifiers are scarcely examined in literature based on large Historical corpora via NLP methods. In order to become better acquainted with trends over time concerning the intensifiers, The exhaustively analysed a specific historical corpus, namely the Magyar TörténetiSzövegtár (Hungarian Historical Corpus). This corpus (containing 3 millions text words) is a collection of texts of various genres and styles, produced between 1772 and 2010. Since the corpus consists of raw texts and does not contain any additional information about the language features of the data (such as stemming or morphological analysis), a large amount of manual work was required to process the data. Thus, based on a lexicon of negative emotive intensifiers compiled in a previous phase of the research, every occurrence of each intensifier was queried, and the results were stored in a separate data frame. Then, basic linguistic processing (POS-tagging, lemmatization etc.) was carried out automatically with the ‘magyarlanc’ NLP-toolkit. Finally, the frequency and collocation features of all the negative emotive words were automatically analyzed in the corpus. Outcomes of the research revealed in detail how these words have proceeded through grammaticalization over time, i.e., they change from lexical elements to grammatical ones, and they slowly go through a delexicalization process (their negative content diminishes over time). What is more, it was also pointed out which negative emotive intensifiers are at the same stage in this process in the same time period. Giving a closer look to the different domains of the analysed corpus, it also became certain that during this process, the pragmatic role’s importance increases: the newer use expresses the speaker's subjective, evaluative opinion at a certain level.Keywords: historical corpus analysis, historical linguistics, negative emotive intensifiers, semantic changes over time
Procedia PDF Downloads 2331377 Developing Scaffolds for Tissue Regeneration using Low Temperature Plasma (LTP)
Authors: Komal Vig
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Cardiovascular disease (CVD)-related deaths occur in 17.3 million people globally each year, accounting for 30% of all deaths worldwide, with a predicted annual incidence of deaths to reach 23.3 million globally by 2030. Autologous bypass grafts remain an important therapeutic option for the treatment of CVD, but the poor quality of the donor patient’s blood vessels, the invasiveness of the resection surgery, and postoperative movement restrictions create issues. The present study is aimed to improve the endothelialization of intimal surface of graft by using low temperature plasma (LTP) to increase the cell attachment and proliferation. Polytetrafluoroethylene (PTFE) was treated with LTP. Air was used as the feed-gas, and the pressure in the plasma chamber was kept at 800 mTorr. Scaffolds were also modified with gelatin and collagen by dipping method. Human umbilical vein endothelial cells (HUVEC) were plated on the developed scaffolds, and cell proliferation was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and by microscopy. mRNA expressions levels of different cell markers were investigated using quantitative real-time PCR (qPCR). XPS confirmed the introduction of oxygenated functionalities from LTP. HUVEC cells showed 80% seeding efficiency on the scaffold. Microscopic and MTT assays indicated increase in cell viability in LTP treated scaffolds, especially when treated with gelatin or collagen, compared to untreated scaffolds. Gene expression studies shows enhanced expression of cell adhesion marker Integrin- α 5 gene after LTP treatment. LTP treated scaffolds exhibited better cell proliferation and viability compared to untreated scaffolds. Protein treatment of scaffold increased cell proliferation. Based on our initial results, more scaffolds alternatives will be developed and investigated for cell growth and vascularization studies. Acknowledgments: This work is supported by the NSF EPSCoR RII-Track-1 Cooperative Agreement OIA-2148653.Keywords: LTP, HUVEC cells, vascular graft, endothelialization
Procedia PDF Downloads 711376 A Method for Precise Vertical Position of the Implant When Using Computerized Surgical Guides and Bone Reduction
Authors: Abraham Finkelman
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Computerized Surgical Guides have been proven to be a predictable way to perform dental implants, with a relatively high accuracy in comparison to a treatment plan. When using the CSG Bone supported, it allows us to make the necessary changes of the hard tissue prior to the implant placement and after the implant placement. The CSG gives us an accurate position for the drilling, and during the implant placement it allows us to alter the vertical position of the implant altering the final position of the abutment and avoiding any risk of any damage to the adjacent anatomical structures. Any Changes required to the bone level can be done prior to the fixation of the CSG using a reduction guide, which incur extra surgical fees and the need of a second surgical guide. Any changes of the bone level after the implant placement are at the risk of damaging the implant neck surface. The technique consists of a universal system that allows us to remove the excess bone around the implant sockets prior to the implant placement which then enables us to place the implant in the vertical position with accuracy as planned with the CSG. The systems consist of a hollow pin of different sizes and diameters. Depending on the implant system that we are using. Length sizes are from 6mm-16mm and a diameter of 2.6mm-4.8mm. Upon the completion of the drilling, the pin is then inserted into the implant socket-using the insertion tool. Once the insertion tool has unscrewed the pin, we can continue with the bone reduction. The bone reduction can be done using conventional methods upon the removal of all the excess bone around the pin. The insertion tool is then screwed into the pin and the pin is then removed. We now, have the new bone level at the crest of the implant socket which is our mark for the vertical position of the implant. In some cases, when we are locating the implant very close to anatomical structures, any form of deviation to the vertical position of the implant during the surgery, can cause damage to such anatomical structures, creating irreversible damages such as paresthesia or dysesthesia of the mandibular nerve. If we are planning for immediate loading and we have done our temporary restauration in base of our computerized plan, deviation in the vertical position of the implant will affect the position of the abutment, affecting the accuracy of the temporary prosthesis, extending the working time till we adapt the prosthesis to the new position.Keywords: bone reduction, computer aided navigation, dental implant placement, surgical guides
Procedia PDF Downloads 3311375 Impact Evaluation and Technical Efficiency in Ethiopia: Correcting for Selectivity Bias in Stochastic Frontier Analysis
Authors: Tefera Kebede Leyu
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The purpose of this study was to estimate the impact of LIVES project participation on the level of technical efficiency of farm households in three regions of Ethiopia. We used household-level data gathered by IRLI between February and April 2014 for the year 2013(retroactive). Data on 1,905 (754 intervention and 1, 151 control groups) sample households were analyzed using STATA software package version 14. Efforts were made to combine stochastic frontier modeling with impact evaluation methodology using the Heckman (1979) two-stage model to deal with possible selectivity bias arising from unobservable characteristics in the stochastic frontier model. Results indicate that farmers in the two groups are not efficient and operate below their potential frontiers i.e., there is a potential to increase crop productivity through efficiency improvements in both groups. In addition, the empirical results revealed selection bias in both groups of farmers confirming the justification for the use of selection bias corrected stochastic frontier model. It was also found that intervention farmers achieved higher technical efficiency scores than the control group of farmers. Furthermore, the selectivity bias-corrected model showed a different technical efficiency score for the intervention farmers while it more or less remained the same for that of control group farmers. However, the control group of farmers shows a higher dispersion as measured by the coefficient of variation compared to the intervention counterparts. Among the explanatory variables, the study found that farmer’s age (proxy to farm experience), land certification, frequency of visit to improved seed center, farmer’s education and row planting are important contributing factors for participation decisions and hence technical efficiency of farmers in the study areas. We recommend that policies targeting the design of development intervention programs in the agricultural sector focus more on providing farmers with on-farm visits by extension workers, provision of credit services, establishment of farmers’ training centers and adoption of modern farm technologies. Finally, we recommend further research to deal with this kind of methodological framework using a panel data set to test whether technical efficiency starts to increase or decrease with the length of time that farmers participate in development programs.Keywords: impact evaluation, efficiency analysis and selection bias, stochastic frontier model, Heckman-two step
Procedia PDF Downloads 751374 Media Framing of Media Regulators in Ghana: A Content Analysis of Selected News Articles on Four Ghanaian Online Newspapers
Authors: Elizabeth Owusu Asiamah
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The Ghanaian news media play a crucial role in shaping people's thinking patterns through the nature of the coverage they give to issues, events and personalities. Since the media do not work in a vacuum but within a broader spectrum, which is society, whatever stories they cover and the nature of frames used to narrate such stories go a long way to influence how citizens perceive issues in the country. Consequently, the National Media Commission and the National Communications Authority were instituted to monitor and direct the activities of the media to ensure professionalism that prioritizes society's interest over commercial interest. As the two media regulators go about their routine task of monitoring the operations of the media, they receive coverage from various media outlets (newspapers, radio, television and online). Some people believe that the kind of approach the regulators adopt depends on the nature of coverage the media give them in their reportage. This situation demands an investigation into how the media, regulated by these regulatory bodies, are representing the regulators in the public's eye and the issues arising from such coverage. Extant literature indicates that studies on media framing have centered on politics, environmental issues, public health issues, conflict and wars, etc. However, there appear to be no studies on media framing of media regulators, especially in the Ghanaian context. Since online newspapers have assumed more mainstream positions in the Ghanaian media and have attracted more audiences in recent times, this study investigates the nature of coverage given to media regulators by four purposively sampled online newspapers in Ghana. 96 news articles are extracted from the websites of the Daily Graphic, Ghanaian Times, Daily Guide and Chronicle newspapers within a five-year period to identify the prominence given to stories about the two media regulators and the frames used to narrate stories about them. Data collected are thematically analyzed through the lens of agenda-setting and media-framing theories. The findings of the study revealed that the two regulators were not given much coverage by way of frequency; however, much prominence was given to them in terms of enhancements such as images. The study further disclosed that most of the news articles framed the regulators as weak and incompetent, which is likely to affect how the public also views the regulators. The study concludes that since frames around the supportive nature of the regulators to issues of the media were not hammered by the online newspapers, the public will not perceive the regulators as playing their roles effectively. Thus, a need for more positive frames to be used to narrate stories about the National Media Commission and the National Communication Authority to promote a cordial relationship between the two institutions and a good image to the public.Keywords: agenda setting, media framing, media regulators, online newspapers
Procedia PDF Downloads 691373 Insight into the Electrocatalytic Activities of Nitrogen-Doped Graphyne and Graphdiyne Families: A First-Principles Study
Authors: Bikram K. Das, Kalyan K. Chattopadhyay
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The advent of 2-D materials in the last decade has induced a fresh spur of growth in fuel cell technology as these materials have some highly promising traits that can be exploited to felicitate Oxygen Reduction Reaction (ORR) in an efficient way. Among the various 2-D carbon materials, graphyne (Gy) and graphdiyne (Gdy)1 with their intrinsic non-uniform charge distribution holds promises in this purpose and it is expected2 that substitutional Nitrogen (N) doping could further enhance their efficiency. In this regard, dispersive force corrected density functional theory is used to map the oxygen reduction reaction (ORR) kinetics of five different kinds of N doped graphyne and graphdiyne systems (namely αGy, βGy, γGy, RGy and 6,6,12Gy and Gdy) in alkaline medium. The best doping site for each of the Gy/ Gdy system is determined comparing the formation energies of the possible doping configurations. Similarly, the best di-oxygen (O₂) adsorption sites for the doped systems are identified by comparing the adsorption energies. O₂ adsorption on all N doped Gy/ Gdy systems is found to be energetically favorable. ORR on a catalyst surface may occur either via the Eley-Rideal (ER) or the Langmuir–Hinschelwood (LH) pathway. Systematic studies performed on the considered systems reveal that all of them favor the ER pathway. Further, depending on the nature of di-oxygen adsorption ORR can follow either associative or dissociative mechanism; the possibility of occurrence of both the mechanisms is tested thoroughly for each N doped Gy/ Gdy. For the ORR process, all the Gy/Gdy systems are observed to prefer the efficient four-electron pathway but the expected monotonically exothermic reaction pathway is found only for N doped 6,6,12Gy and RGy following the associative pathway and for N doped βGy, γGy and Gdy following the dissociative pathway. Further computation performed for these systems reveals that for N doped 6,6,12Gy, RGy, βGy, γGy and Gdy the overpotentials are 1.08 V, 0.94 V, 1.17 V, 1.21 V and 1.04 V respectively depicting N doped RGy is the most promising material, to carry out ORR in alkaline medium, among the considered ones. The stability of the ORR intermediate states with the variation of pH and electrode potentials is further explored with Pourbiax diagrams and the activities of these systems in the alkaline medium are compared with the prior reported B/N doped identical systems for ORR in an acidic medium in terms of a common descriptor.Keywords: graphdiyne, graphyne, nitrogen-doped, ORR
Procedia PDF Downloads 1281372 Dietary Patterns and Hearing Loss in Older People
Authors: N. E. Gallagher, C. E. Neville, N. Lyner, J. Yarnell, C. C. Patterson, J. E. Gallacher, Y. Ben-Shlomo, A. Fehily, J. V. Woodside
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Hearing loss is highly prevalent in older people and can reduce quality of life substantially. Emerging research suggests that potentially modifiable risk factors, including risk factors previously related to cardiovascular disease risk, may be associated with a decreased or increased incidence of hearing loss. This has prompted investigation into the possibility that certain nutrients, foods or dietary patterns may also be associated with incidence of hearing loss. The aim of this study was to determine any associations between dietary patterns and hearing loss in men enrolled in the Caerphilly study. The Caerphilly prospective cohort study began in 1979-1983 with recruitment of 2512 men aged 45-59 years. Dietary data was collected using a self-administered, semi-quantitative, 56-item food frequency questionnaire (FFQ) at baseline (1979-1983), and 7-day weighed food intake (WI) in a 30% sub-sample, while pure-tone unaided audiometric threshold was assessed at 0.5, 1, 2 and 4 kHz, between 1984 and 1988. Principal components analysis (PCA) was carried out to determine a posteriori dietary patterns and multivariate linear and logistic regression models were used to examine associations with hearing level (pure tone average (PTA) of frequencies 0.5, 1, 2 and 4 kHz in decibels (dB)) for linear regression and with hearing loss (PTA>25dB) for logistic regression. Three dietary patterns were determined using PCA on the FFQ data- Traditional, Healthy, High sugar/Alcohol avoider. After adjustment for potential confounding factors, both linear and logistic regression analyses showed a significant and inverse association between the Healthy pattern and hearing loss (P<0.001) and linear regression analysis showed a significant association between the High sugar/Alcohol avoider pattern and hearing loss (P=0.04). Three similar dietary patterns were determined using PCA on the WI data- Traditional, Healthy, High sugar/Alcohol avoider. After adjustment for potential confounding factors, logistic regression analyses showed a significant and inverse association between the Healthy pattern and hearing loss (P=0.02) and a significant association between the Traditional pattern and hearing loss (P=0.04). A Healthy dietary pattern was found to be significantly inversely associated with hearing loss in middle-aged men in the Caerphilly study. Furthermore, a High sugar/Alcohol avoider pattern (FFQ) and a Traditional pattern (WI) were associated with poorer hearing levels. Consequently, the role of dietary factors in hearing loss remains to be fully established and warrants further investigation.Keywords: ageing, diet, dietary patterns, hearing loss
Procedia PDF Downloads 2301371 Avifauna of Bara Gali Summer Campus, University of Peshawar, Khyber Pakhtunkhwa
Authors: Saif Ullah, Zaigham Hasan, Muhammad Ali, Qaisar Jamal, Kiran Salahuddin, Muhammad Awais
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Survey of avian fauna of Bara Gali Summer Campus, University of Peshawar situated in Abbottabad was conducted from April to October, 2013. A total of 21 species belonging to 5 orders and 15 families were recorded. Out of these, 6 were resident, 12 summer visitor and 3 rare. Order Passeriformes was represented by 16 species which are Certhia himalayana, Megalaima virens, Phylloscopus trochiloides, Garrulax lineatus, Passer rutilans, Corvus macrorhynchos, Hypsipetes leucocephalus, Acridotheres tristis, Delichon dasypus cashmeriensis, Hirundo rustica, Muscicapa thalassina, Saxicola ferrea, Myiophoneus caeruleus, Parus melonolophus, Parus rufonuchalis, Parus monticolus, belonging to 11 families. Two species Dendrocopos himalayansis and Picus squamatus belong to only one family Picidae of order Piciformes. Among rest of the three orders each is represented by only a single species; Accipitriformes by Accipiter virgatus, Coraciformes by Upupa epops while order Psittaciformes has been represented by Psittacula himalayana. The distribution and abundance varied with season and maximum number of species were found during the monsoon season when most of the birds migrate for breeding. Some habits and behaviors like nesting, feeding, breeding and vocalizations were also studied which are very unique from other birds found at lower elevations. Among bird species adapted to diverse habitat in the field, Himalayan Jungle Crow, Common Mynas, Bulbuls, Barn Swallows, barbets were prominent. Interesting feature of the avian fauna is its familiarity with flora, was also observed during the present studies that some birds are very quick and active in their movement on a tree surface i.e Certhia himalayana.Keywords: avifauna diversity, distribution, Bara Gali, Abbottabad
Procedia PDF Downloads 3781370 RPM-Synchronous Non-Circular Grinding: An Approach to Enhance Efficiency in Grinding of Non-Circular Workpieces
Authors: Matthias Steffan, Franz Haas
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The production process grinding is one of the latest steps in a value-added manufacturing chain. Within this step, workpiece geometry and surface roughness are determined. Up to this process stage, considerable costs and energy have already been spent on components. According to the current state of the art, therefore, large safety reserves are calculated in order to guarantee a process capability. Especially for non-circular grinding, this fact leads to considerable losses of process efficiency. With present technology, various non-circular geometries on a workpiece must be grinded subsequently in an oscillating process where X- and Q-axis of the machine are coupled. With the approach of RPM-Synchronous Noncircular Grinding, such workpieces can be machined in an ordinary plung grinding process. Therefore, the workpieces and the grinding wheels revolutionary rate are in a fixed ratio. A non-circular grinding wheel is used to transfer its geometry onto the workpiece. The authors use a worldwide unique machine tool that was especially designed for this technology. Highest revolution rates on the workpiece spindle (up to 4500 rpm) are mandatory for the success of this grinding process. This grinding approach is performed in a two-step process. For roughing, a highly porous vitrified bonded grinding wheel with medium grain size is used. It ensures high specific material removal rates for efficiently producing the non-circular geometry on the workpiece. This process step is adapted by a force control algorithm, which uses acquired data from a three-component force sensor located in the dead centre of the tailstock. For finishing, a grinding wheel with a fine grain size is used. Roughing and finishing are performed consecutively among the same clamping of the workpiece with two locally separated grinding spindles. The approach of RPM-Synchronous Noncircular Grinding shows great efficiency enhancement in non-circular grinding. For the first time, three-dimensional non-circular shapes can be grinded that opens up various fields of application. Especially automotive industries show big interest in the emerging trend in finishing machining.Keywords: efficiency enhancement, finishing machining, non-circular grinding, rpm-synchronous grinding
Procedia PDF Downloads 2831369 Geophysical Mapping of Anomalies Associated with Sediments of Gwandu Formation Around Argungu and Its Environs NW, Nigeria
Authors: Adamu Abubakar, Abdulganiyu Yunusa, Likkason Othniel Kamfani, Abdulrahman Idris Augie
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This research study is being carried out in accordance with the Gwandu formation's potential exploratory activities in the inland basin of northwest Nigeria.The present research aims to identify and characterize subsurface anomalies within Gwandu formation using electrical resistivity tomography (ERT) and magnetic surveys, providing valuable insights for mineral exploration. The study utilizes various data enhancement techniques like derivatives, upward continuation, and spectral analysis alongside 2D modeling of electrical imaging profiles to analyze subsurface structures and anomalies. Data was collected through ERT and magnetic surveys, with subsequent processing including derivatives, spectral analysis, and 2D modeling. The results indicate significant subsurface structures such as faults, folds, and sedimentary layers. The study area's geoelectric and magnetic sections illustrate the depth and distribution of sedimentary formations, enhancing understanding of the geological framework. Thus, showed that the entire formations of Eocene sediment of Gwandu are overprinted by the study area's Tertiary strata. The NE to SW and E to W cross-profile for the pseudo geoelectric sections beneath the study area were generated using a two-dimensional (2D) electrical resistivity imaging. 2D magnetic modelling, upward continuation, and derivative analysis are used to delineate the signatures of subsurface magnetic anomalies. The results also revealed The sediment thickness by surface depth ranges from ∼4.06 km and ∼23.31 km. The Moho interface, the lower and upper mantle crusts boundary, and magnetic crust are all located at depths of around ∼10.23 km. The vertical distance between the local models of the foundation rocks to the north and south of the Sokoto Group was approximately ∼6 to ∼8 km and ∼4.5 km, respectively.Keywords: high-resolution aeromagnetic data, electrical resistivity imaging, subsurface anomalies, 2d dorward modeling
Procedia PDF Downloads 141368 Linkage Disequilibrium and Haplotype Blocks Study from Two High-Density Panels and a Combined Panel in Nelore Beef Cattle
Authors: Priscila A. Bernardes, Marcos E. Buzanskas, Luciana C. A. Regitano, Ricardo V. Ventura, Danisio P. Munari
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Genotype imputation has been used to reduce genomic selections costs. In order to increase haplotype detection accuracy in methods that considers the linkage disequilibrium, another approach could be used, such as combined genotype data from different panels. Therefore, this study aimed to evaluate the linkage disequilibrium and haplotype blocks in two high-density panels before and after the imputation to a combined panel in Nelore beef cattle. A total of 814 animals were genotyped with the Illumina BovineHD BeadChip (IHD), wherein 93 animals (23 bulls and 70 progenies) were also genotyped with the Affymetrix Axion Genome-Wide BOS 1 Array Plate (AHD). After the quality control, 809 IHD animals (509,107 SNPs) and 93 AHD (427,875 SNPs) remained for analyses. The combined genotype panel (CP) was constructed by merging both panels after quality control, resulting in 880,336 SNPs. Imputation analysis was conducted using software FImpute v.2.2b. The reference (CP) and target (IHD) populations consisted of 23 bulls and 786 animals, respectively. The linkage disequilibrium and haplotype blocks studies were carried out for IHD, AHD, and imputed CP. Two linkage disequilibrium measures were considered; the correlation coefficient between alleles from two loci (r²) and the |D’|. Both measures were calculated using the software PLINK. The haplotypes' blocks were estimated using the software Haploview. The r² measurement presented different decay when compared to |D’|, wherein AHD and IHD had almost the same decay. For r², even with possible overestimation by the sample size for AHD (93 animals), the IHD presented higher values when compared to AHD for shorter distances, but with the increase of distance, both panels presented similar values. The r² measurement is influenced by the minor allele frequency of the pair of SNPs, which can cause the observed difference comparing the r² decay and |D’| decay. As a sum of the combinations between Illumina and Affymetrix panels, the CP presented a decay equivalent to a mean of these combinations. The estimated haplotype blocks detected for IHD, AHD, and CP were 84,529, 63,967, and 140,336, respectively. The IHD were composed by haplotype blocks with mean of 137.70 ± 219.05kb, the AHD with mean of 102.10kb ± 155.47, and the CP with mean of 107.10kb ± 169.14. The majority of the haplotype blocks of these three panels were composed by less than 10 SNPs, with only 3,882 (IHD), 193 (AHD) and 8,462 (CP) haplotype blocks composed by 10 SNPs or more. There was an increase in the number of chromosomes covered with long haplotypes when CP was used as well as an increase in haplotype coverage for short chromosomes (23-29), which can contribute for studies that explore haplotype blocks. In general, using CP could be an alternative to increase density and number of haplotype blocks, increasing the probability to obtain a marker close to a quantitative trait loci of interest.Keywords: Bos taurus indicus, decay, genotype imputation, single nucleotide polymorphism
Procedia PDF Downloads 2801367 Effects of Sintering Temperature on Microstructure and Mechanical Properties of Nanostructured Ni-17Cr Alloy
Authors: B. J. Babalola, M. B. Shongwe
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Spark Plasma Sintering technique is a novel processing method that produces limited grain growth and highly dense variety of materials; alloys, superalloys, and carbides just to mention a few. However, initial particle size and spark plasma sintering parameters are factors which influence the grain growth and mechanical properties of sintered materials. Ni-Cr alloys are regarded as the most promising alloys for aerospace turbine blades, owing to the fact that they meet the basic requirements of desirable mechanical strength at high temperatures and good resistance to oxidation. The conventional method of producing this alloy often results in excessive grain growth and porosity levels that are detrimental to its mechanical properties. The effect of sintering temperature was evaluated on the microstructure and mechanical properties of the nanostructured Ni-17Cr alloy. Nickel and chromium powder were milled using high energy ball milling independently for 30 hours, milling speed of 400 revs/min and ball to powder ratio (BPR) of 10:1. The milled powders were mixed in the composition of Nickel having 83 wt % and chromium, 17 wt %. This was sintered at varied temperatures from 800°C, 900°C, 1000°C, 1100°C and 1200°C. The structural characteristics such as porosity, grain size, fracture surface and hardness were analyzed by scan electron microscopy and X-ray diffraction, Archimedes densitometry, micro-hardness tester. The corresponding results indicated an increase in the densification and hardness property of the alloy as the temperature increases. The residual porosity of the alloy reduces with respect to the sintering temperature and in contrast, the grain size was enhanced. The study of the mechanical properties, including hardness, densification shows that optimum properties were obtained for the sintering temperature of 1100°C. The advantages of high sinterability of Ni-17Cr alloy using milled powders and microstructural details were discussed.Keywords: densification, grain growth, milling, nanostructured materials, sintering temperature
Procedia PDF Downloads 4021366 Basal Cell Carcinoma Excision Intraoperative Frozen Section for Tumor Clearance and Reconstructive Surgery: A Prospective Open Label Interventional Study
Authors: Moizza Tahir, Uzma Bashir, Aisha Akhtar, Zainab Ansari, Sameen Ansari, Muhammad Ali Tahir
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Cancer burden has globally increased. Among cutaneous cancers basal cell carcinoma constitute vast majority of skin cancer. There is need for appropriate diagnostic, therapeutic and prognostic significance evaluation for skin cancers Present study report intraoperative frozen section (FS) histopathological clearance for excision of BCC in a tertiary care center and find the frequency of involvement of surgical margin with reference to anatomical site, with size and surgical technique. It was prospective open label interventional study conducted at Dermatology department of tertiary care hospital Rawalpindi Pakistan in lais on with histopathology department from January 2023 to April 2024. Total of thirty-six (n = 36) patients between age 45-80 years with basal cell carcinoma of 10-20mm on face were included following inclusion exclusion criteria by purposive sampling technique. Informed consent was taken. Surgical excision was performed and intraoperative frozen section histopathology clearance of tumor margin was taken from histopathologist on telephone. Surgical reconstruction was done. Final Histopathology report was reexamined on day 10th for margin and depth clearance. Descriptive statistics were calculated for age, gender, sun exposure, reconstructive technique, anatomical site, and tumor free margin report on frozen section analysis. Chi square test was employed for statistical significance of involvement of surgical margin with reference to anatomical site, size and decision on reconstructive surgical technique, p value of <0.05 was considered significant. Total of 36 patients of BCC were enrolled, males 12 (33.3%) and females were 24 (66.6%). Age ranged from 45 year to 80 year mean of 58.36 ±SD7.8. Size of BCC ranged from 10mm to 35mm mean of 25mm ±SD 0.63. Morphology was nodular 18 (50%), superficial spreading 11(30.6%), morphoeic 1 (2.8%) and ulcerative in 6(16.7%) cases. Intraoperative frozen section for histopathological margin clearance with 2-3 mm safety margin and surgical technique has p-value0.51, for anatomical site p value 0.24 and size p-0.84. Intraoperative frozen section (FS) histopathological clearance for BCC face with 2-3mm safety margin with reference to reconstructive technique, anatomical site and size of BCC were insignificant.Keywords: basal cell carcinoma, tumor free amrgin, basal cell carcinoma and frozen section, safety margin
Procedia PDF Downloads 551365 Effect of Fast Fashion on Urban Indian Consumer
Authors: Neha Dimri, Varsha Gupta
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Purpose: Fast Fashion trend promotes consumption of low cost high fashion garments at a rapid rate. Frequent change in fashion trend results in higher disposability of Fast Fashion products. To cater for the Fast Fashion appetite of the present day consumer, fashion giants have ramped up production of garments, thus imposing a massive strain on the planet’s natural resources. Also, ethical issues related to cheaper methods of production are of concern. India being a large consumer base has a major role to play in proliferation of the Fast Fashion trend. This paper is an attempt to study the effect of fast fashion trends on the Indian consumer’s behaviour. It also attempts to ascertain the awareness of the consumer about the detrimental effect that the fast fashion trends manifest on the environment. Design /methodology/approach: The survey was conducted using a questionnaire targeted at a set of urban Indian consumers of varied age, profession and socio economic backgrounds. Trends regarding frequency of purchase, expenditure on clothing, disposal methods and awareness about environmental issues were analyzed using the obtained data. Findings: The result of the study indicates that urban Indian consumer has a strong affinity towards fast fashion trends, but is largely unaware of its detrimental effect on the environment and strain on natural resources. Research Limitation/implications: The sample size for survey was only of a hundred consumers, and the same could be expanded for a better estimate of trends. Also, the sample consumers were mostly urban. A big chunk of Indian fashion consumers reside in small towns and the same could be included in the survey. Practical implications: As the true cost of Fast Fashion in terms of environmental and ethical aspects is getting realized worldwide, a big market like India cannot remain isolated from this phenomenon. Globally there has been an increase in demand of ethically produced clothing. It is imperative that the Indian consumer be made aware about the unsustainable nature of Fast Fashion so that he can contribute towards conservation of natural resources and ethical production of garments. Originality/value The research attempts to ascertain consumption pattern of the Indian fashion consumer and also his awareness about the true cost and consequences of Fast Fashion. The inferences may be used by fashion giants to use ‘Green Marketing’ and ‘Social Marketing’ techniques to make the Indian consumer more aware about sustainable fashion and to market their own products as ‘Sustainable, Green and Ethical’.Keywords: consumption, disposable, fast fashion, Indian consumer
Procedia PDF Downloads 3111364 Localized and Time-Resolved Velocity Measurements of Pulsatile Flow in a Rectangular Channel
Authors: R. Blythman, N. Jeffers, T. Persoons, D. B. Murray
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The exploitation of flow pulsation in micro- and mini-channels is a potentially useful technique for enhancing cooling of high-end photonics and electronics systems. It is thought that pulsation alters the thickness of the hydrodynamic and thermal boundary layers, and hence affects the overall thermal resistance of the heat sink. Although the fluid mechanics and heat transfer are inextricably linked, it can be useful to decouple the parameters to better understand the mechanisms underlying any heat transfer enhancement. Using two-dimensional, two-component particle image velocimetry, the current work intends to characterize the heat transfer mechanisms in pulsating flow with a mean Reynolds number of 48 by experimentally quantifying the hydrodynamics of a generic liquid-cooled channel geometry. Flows circulated through the test section by a gear pump are modulated using a controller to achieve sinusoidal flow pulsations with Womersley numbers of 7.45 and 2.36 and an amplitude ratio of 0.75. It is found that the transient characteristics of the measured velocity profiles are dependent on the speed of oscillation, in accordance with the analytical solution for flow in a rectangular channel. A large velocity overshoot is observed close to the wall at high frequencies, resulting from the interaction of near-wall viscous stresses and inertial effects of the main fluid body. The steep velocity gradients at the wall are indicative of augmented heat transfer, although the local flow reversal may reduce the upstream temperature difference in heat transfer applications. While unsteady effects remain evident at the lower frequency, the annular effect subsides and retreats from the wall. The shear rate at the wall is increased during the accelerating half-cycle and decreased during deceleration compared to steady flow, suggesting that the flow may experience both enhanced and diminished heat transfer during a single period. Hence, the thickness of the hydrodynamic boundary layer is reduced for positively moving flow during one half of the pulsation cycle at the investigated frequencies. It is expected that the size of the thermal boundary layer is similarly reduced during the cycle, leading to intervals of heat transfer enhancement.Keywords: Heat transfer enhancement, particle image velocimetry, localized and time-resolved velocity, photonics and electronics cooling, pulsating flow, Richardson’s annular effect
Procedia PDF Downloads 3461363 Study of Surface Water Quality in the Wadi El Harrach for Its Use in the Artificial Groundwater Recharge of the Mitidja, North Algeria
Authors: M. Meddi, A. Boufekane
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The Mitidja coastal groundwater which extends over an area of 1450 km2 is a strategic resource in the Algiers region. The high dependence of the regional economy on the use of this groundwater forces us to have recourse to its artificial recharge from the Wadi El Harrach in its upstream part. This system of artificial recharge has shown its effectiveness in the development of water resource mentioned in the succeeding works in several regions of the world. The objective of this study is to: Increase the reserves of water inputs by infiltration, raise the water level and its good quality in wells and boreholes, reduce losses to the sea, and address seawater intrusion by maintaining balance in the freshwater-saltwater interface in the downstream part of the groundwater basin. After analyzing the situation, it was noticed that a qualitative monitoring of the Wadi water for the groundwater recharge has to be done. For this purpose, we proceeded during three successive years (2010, 2011, and 2012) to the monthly sampling of water in the upstream part of the Wadi El Harrach for chemical analysis. The variation of the sediment transport concentration will be also measured. This monitoring aims to characterize the water quality and avoid clogging in the proposed recharge area. The results of these analyses showed the good chemical quality according to the analyses we performed in the laboratory during the three years, but they are too loaded with suspended matters. We noticed that these fine particles come from the grinding of limestone of sandpit located upstream of the area of the proposed recharge system. This problem can be solved by a water supply upstream of sandpit. For the recharge, we propose the method of using two wells for dual use, which means that it can be used for water supply and extraction. This solution is inexpensive in our case and could easily be used as wells are already drilled in the upstream part. This solution increases over time the piezometric level and also reduce groundwater contamination by saltwater in the downstream part.Keywords: water quality, artificial groundwater recharge, Mitidja, North Algeria
Procedia PDF Downloads 2871362 Integration, a Tool to Develop Critical Thinking Skills of Undergraduate Veterinary Students
Authors: M. L. W. P. De Silva, R. A. C. Rabel, N. Smith, L. McIntyre, T. J Parkinson, K. A. N. Wijayawardhane
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Curricular integration is an important concept in medical education for developing students’ ability to create connections between different medical disciplines. Problem-Based Learning (PBL) is one of the vehicles through which such integration can be achieved. During the recent review of the veterinary curriculum at the University of Peradeniya, a series of courses in Integrative Veterinary Science (IVS) were introduced, in which PBL was the primary teaching methodology. The objectives of this study were to evaluate students’ opinions on PBL as a teaching method: it should be noted that, within the context of secondary and tertiary education in Sri Lanka, this would be an entirely novel learning experience for the students. Opinions were sought at the conclusion of IVS sessions where students of semesters 2, 4, 6, and 7 (of an 8-semester program) were exposed to a two, 2-hour PBL-based case scenario. The PBL-based case scenario in semesters 2, 4, and 7 were delivered using material previously developed by an experienced PBL practitioner, whilst material for semester 6 was prepared de novo by a less experienced practitioner. Each student (semesters 2: n=38, 4: n=37, 6: n=55, and 7: n=40) completed a questionnaire which asked whether: (i) the course had improved their critical thinking skills; (ii) the learning environment was sufficiently comfortable to express/share student’s opinion; (iii) there was sufficient facilitator guidance; (iv) the online study environment enhanced learning; and (v) the students were overall satisfied with the PBL approach and IVS concept. Responses were given on a 5-point Likert-scale (strongly agree (SA), agree (A), neutral (N), disagree (D), and strongly disagree (SD)). SA and A responses were summed to provide an overall ‘satisfactory’ response. Results were subjected to frequency-distribution statistical analysis. A total of 88.5% of students gave SA+A scores to their overall satisfaction. The proportion of SA+A scores differed between different semesters, such that 95% of semester 2, 4, and 7 students gave SA+A scores, whereas only 69% of semester 6 students did so for their respective sessions. Overall, 96% of the students gave SA+A scores to the question relating to the improvement of critical thinking skills: semester 6 students’ scores were marginally, but not significantly, lower (91% SA+A) than those in other semesters. The difference of scores between semester 6 and the other semesters may be attributed to the different PBL-material used and/or the different experience levels of the practitioners that developed the study material. The use of PBL as a means of teaching IVS curriculum-integration courses was well-received by the students in terms of their overall satisfaction and their perceptions of improved critical thinking skills. Importantly, this was achieved in the face of a methodology that was entirely novel to the students. Finally, the delivery of the PBL medium was readily mastered by the practitioner to whom it was also a novel methodology.Keywords: critical thinking skills, integration, problem based learning, veterinary education
Procedia PDF Downloads 1331361 Developing a Thermo-Sensitive Conductive Stretchable Film to Allow Cell Sheet Harvest after Mechanical and Electrical Treatments
Authors: Wei-Wen Hu, Yong-Zhi Zhong
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Depositing conductive polypyrrole (PPy) onto elastic polydimethylsiloxane (PDMS) substrate can obtain a highly stretchable conductive film, which can be used to construct a bioreactor to cyclically stretch and electrically stimulate surface cells. However, how to completely harvest these stimulated muscle tissue to repair damaged muscle is a challenge. To address this concern, N-isopropylacrylamide (NIPAAm), a monomer of temperature-sensitive polymer, was added during the polymerization of pyrrole on PDMS so that the resulting P(Py-co-NIPAAm)/PDMS should own both conductivity and thermo-sensitivity. Therefore, cells after stimulation can be completely harvested as cell sheets by reducing temperature. Mouse skeletal myoblast, C2C12 cells, were applied to examine our hypothesis. In electrical stimulation, C2C12 cells on P(Py-co-NIPAAm)/PDMS demonstrated the best myo-differentiation under the electric field of 1 V/cm. Regarding cyclic stretching, the strain equal to or higher than 9% can highly align C2C12 perpendicular to the stretching direction. The Western blotting experiments demonstrated that the cell sheets harvested by cooling reserved more extracellular matrix (ECM) than cells collected by the traditional trypsin digestion method. Immunostaining of myosin heavy chain protein (MHC) indicated that both mechanical and electrical stimuli effectively increased the number of myotubes and the differentiation ratio, and the myotubes can be aligned by cyclic stretching. Stimulated cell sheets can be harvested by cooling, and the alignment of myotubes was still maintained. These results suggested that the deposition of P(Py-co-NIPAAm) on PDMS can be applied to harvest intact cell sheets after cyclic stretching and electrical stimulation, which increased the feasibility of bioreactor for the application of tissue engineering and regenerative medicine.Keywords: bioreactor, cell sheet, conductive polymer, cyclic stretching, electrical stimulation, muscle tissue engineering, myogenesis, thermosensitive hydrophobicity
Procedia PDF Downloads 951360 Pale, Soft, Exudative (PSE) Turkey Meat in a Brazilian Commercial Processing Plant
Authors: Danielle C. B. Honorato, Rafael H. Carvalho, Adriana L. Soares, Ana Paula F. R. L. Bracarense, Paulo D. Guarnieri, Massami Shimokomaki, Elza I. Ida
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Over the past decade, the Brazilian production of turkey meat increased by more than 50%, indicating that the turkey meat is considered a great potential for the Brazilian economy contributing to the growth of agribusiness at the marketing international scenario. However, significant color changes may occur during its processing leading to the pale, soft and exudative (PSE) appearance on the surface of breast meat due to the low water holding capacity (WHC). Changes in PSE meat functional properties occur due to the myofibrils proteins denaturation caused by a rapid postmortem glycolysis resulting in a rapid pH decline while the carcass temperature is still warm. The aim of this study was to analyze the physical, chemical and histological characteristics of PSE turkey meat obtained from a Brazilian commercial processing plant. The turkey breasts samples were collected (n=64) at the processing line and classified as PSE at L* ≥ 53 value. The pH was also analyzed after L* measurement. In sequence, PSE meat samples were evaluated for WHC, cooking loss (CL), shear force (SF), myofibril fragmentation index (MFI), protein denaturation (PD) and histological evaluation. The abnormal color samples presented lower pH values, 16% lower fiber diameter, 11% lower SF and 2% lower WHC than those classified as normal. The CL, PD and MFI were, respectively, 9%, 18% and 4% higher in PSE samples. The Pearson correlation between the L* values and CL, PD and MFI was positive, while that SF and pH values presented negative correlation. Under light microscopy, a shrinking of PSE muscle cell diameter was approximately 16% shorter in relation to normal samples and an extracellular enlargement of endomysium and perimysium sheaths as the consequence of higher water contents lost as observed previously by lower WHC values. Thus, the results showed that PSE turkey breast meat presented significant changes in their physical, chemical and histological characteristics that may impair its functional properties.Keywords: functional properties, histological evaluation, meat quality, PSE
Procedia PDF Downloads 4601359 Nanopriming Potential of Metal Nanoparticles against Internally Seed Borne Pathogen Ustilago triciti
Authors: Anjali Sidhu, Anju Bala, Amit Kumar
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Metal nanoparticles have the potential to revolutionize the agriculture owing to sizzling interdisciplinary nano-technological application domain. Numerous patents and products incorporating engineered nanoparticles (NPs) entered into agro-applications with the collective goal to promote proficiency as well as sustainability with lower input and generating meager waste than conventional products and approaches. Loose smut of wheat caused by Ustilago segetum tritici is an internally seed-borne pathogen. It is dormant in the seed unless the seed germinates and its symptoms are expressed at the reproductive stage of the plant only. Various seed treatment agents are recommended for this disease but due to the inappropriate methods of seed treatments used by farmers, each and every seed may not get treated, and the infected seeds escape the fungicidal action. The antimicrobial potential and small size of nanoparticles made them the material of choice as they could enter each seed and restrict the pathogen inside the seed due to the availability of more number of nanoparticles per unit volume of the nanoformulations. Nanoparticles of diverse nature known for their in vitro antimicrobial activity viz. ZnO, MgO, CuS and AgNPs were synthesized, surface modified and characterized by traditional methods. They were applied on infected wheat seeds which were then grown in pot conditions, and their mycelium was tracked in the shoot and leaf region of the seedlings by microscopic staining techniques. Mixed responses of inhibition of this internal mycelium were observed. The time and method of application concluded to be critical for application, which was optimised in the present work. The results implicated that there should be field trails to get final fate of these pot trails up to commercial level. The success of their field trials could be interpreted as a revolution to replace high dose organic fungicides of high residue behaviour.Keywords: metal nanoparticles, nanopriming, seed borne pathogen, Ustilago segetum tritici
Procedia PDF Downloads 1441358 Aerial Photogrammetry-Based Techniques to Rebuild the 30-Years Landform Changes of a Landslide-Dominated Watershed in Taiwan
Authors: Yichin Chen
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Taiwan is an island characterized by an active tectonics and high erosion rates. Monitoring the dynamic landscape of Taiwan is an important issue for disaster mitigation, geomorphological research, and watershed management. Long-term and high spatiotemporal landform data is essential for quantifying and simulating the geomorphological processes and developing warning systems. Recently, the advances in unmanned aerial vehicle (UAV) and computational photogrammetry technology have provided an effective way to rebuild and monitor the topography changes in high spatio-temporal resolutions. This study rebuilds the 30-years landform change in the Aiyuzi watershed in 1986-2017 by using the aerial photogrammetry-based techniques. The Aiyuzi watershed, located in central Taiwan and has an area of 3.99 Km², is famous for its frequent landslide and debris flow disasters. This study took the aerial photos by using UAV and collected multi-temporal historical, stereo photographs, taken by the Aerial Survey Office of Taiwan’s Forestry Bureau. To rebuild the orthoimages and digital surface models (DSMs), Pix4DMapper, a photogrammetry software, was used. Furthermore, to control model accuracy, a set of ground control points was surveyed by using eGPS. The results show that the generated DSMs have the ground sampling distance (GSD) of ~10 cm and ~0.3 cm from the UAV’s and historical photographs, respectively, and vertical error of ~1 m. By comparing the DSMs, there are many deep-seated landslides (with depth over 20 m) occurred on the upstream in the Aiyuzi watershed. Even though a large amount of sediment is delivered from the landslides, the steep main channel has sufficient capacity to transport sediment from the channel and to erode the river bed to ~20 m in depth. Most sediments are transported to the outlet of watershed and deposits on the downstream channel. This case study shows that UAV and photogrammetry technology are useful for topography change monitoring effectively.Keywords: aerial photogrammetry, landslide, landform change, Taiwan
Procedia PDF Downloads 1571357 A Low-Cost of Foot Plantar Shoes for Gait Analysis
Authors: Zulkifli Ahmad, Mohd Razlan Azizan, Nasrul Hadi Johari
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This paper presents a study on development and conducting of a wearable sensor system for gait analysis measurement. For validation, the method of plantar surface measurement by force plate was prepared. In general gait analysis, force plate generally represents a studies about barefoot in whole steps and do not allow analysis of repeating movement step in normal walking and running. The measurements that were usually perform do not represent the whole daily plantar pressures in the shoe insole and only obtain the ground reaction force. The force plate measurement is usually limited a few step and it is done indoor and obtaining coupling information from both feet during walking is not easily obtained. Nowadays, in order to measure pressure for a large number of steps and obtain pressure in each insole part, it could be done by placing sensors within an insole. With this method, it will provide a method for determine the plantar pressures while standing, walking or running of a shoe wearing subject. Inserting pressure sensors in the insole will provide specific information and therefore the point of the sensor placement will result in obtaining the critical part under the insole. In the wearable shoe sensor project, the device consists left and right shoe insole with ten FSR. Arduino Mega was used as a micro-controller that read the analog input from FSR. The analog inputs were transmitted via bluetooth data transmission that gains the force data in real time on smartphone. Blueterm software which is an android application was used as an interface to read the FSR reading on the shoe wearing subject. The subject consist of two healthy men with different age and weight doing test while standing, walking (1.5 m/s), jogging (5 m/s) and running (9 m/s) on treadmill. The data obtain will be saved on the android device and for making an analysis and comparison graph.Keywords: gait analysis, plantar pressure, force plate, earable sensor
Procedia PDF Downloads 4531356 Developing a Self-Healing Concrete Filler Using Poly(Methyl Methacrylate) Based Two-Part Adhesive
Authors: Shima Taheri, Simon Clark
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Concrete is an essential building material used in the majority of structures. Degradation of concrete over time increases the life-cycle cost of an asset with an estimated annual cost of billions of dollars to national economies. Most of the concrete failure occurs due to cracks, which propagate through a structure and cause weakening leading to failure. Stopping crack propagation is thus the key to protecting concrete structures from failure and is the best way to prevent inconveniences and catastrophes. Furthermore, the majority of cracks occur deep within the concrete in inaccessible areas and are invisible to normal inspection. Few materials intrinsically possess self-healing ability, but one that does is concrete. However, self-healing in concrete is limited to small dormant cracks in a moist environment and is difficult to control. In this project, we developed a method for self-healing of nascent fractures in concrete components through the automatic release of self-curing healing agents encapsulated in breakable nano- and micro-structures. The Poly(methyl methacrylate) (PMMA) based two-part adhesive is encapsulated in core-shell structures with brittle/weak inert shell, synthesized via miniemulsion/solvent evaporation polymerization. Stress fields associated with propagating cracks can break these capsules releasing the healing agents at the point where they are needed. The shell thickness is playing an important role in preserving the content until the final setting of concrete. The capsules can also be surface functionalized with carboxyl groups to overcome the homogenous mixing issues. Currently, this formulated self-healing system can replace up to 1% of cement in a concrete formulation. Increasing this amount to 5-7% in the concrete formulation without compromising compression strength and shrinkage properties, is still under investigation. This self-healing system will not only increase the durability of structures by stopping crack propagation but also allow the use of less cement in concrete construction, thereby adding to the global effort for CO2 emission reduction.Keywords: self-healing concrete, concrete crack, concrete deterioration, durability
Procedia PDF Downloads 1181355 The Fantasy of the Media and the Sexual World of Adolescents: The Relationship between Viewing Sexual Content on Television and Sexual Behaviour of Adolescents
Authors: Ifeanyi Adigwe
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The influence of television on adolescents is prevalent and widespread because television is a powerful sex educator for adolescents. This study examined the relationship between viewing sexual content on television and sexual behaviour of adolescents in public senior secondary schools in Lagos, Nigeria. The study employed a survey research design with a structured questionnaire as instrument. The multi-stage sampling technique was adopted. Firstly, purposive sampling was adopted in selecting 3 educational districts namely: Agege, Maryland, and Agboju. These educational districts were chosen for convenience and its wide coverage area of public senior secondary schools in Lagos State. Secondly, the researcher adopted systematic sampling to select the schools. The schools were listed in alphabetical order in each district and every 10th school were selected, yielding 13 schools altogether. A total of 501 copies of questionnaire were administered to the students and a total 491 copies of the questionnaire were retrieved. Only 453 copies of the questionnaire met the inclusion criteria and were used for analysis. Data were analyzed using descriptive statistics, Pearson Correlation, Principal components analysis, and regression analysis. Results of correlation analysis showed a positive and significant relationship between adolescent sexual belief and their preference for sexual content in television (r =0.117, N =453, p=0.13), viewing sexual content on television and adolescent sexual behavior, (r =-0.112, N =453, p<0.05), adolescent television preference and their preference for sexual content in television (r =0.328, N =453, p<0.05), adolescent television preference and adolescent’s sexual behavior (r=0.093, N =453, p<0.05). However, a negative but significant relationship exists between adolescent’s sexual knowledge and their sexual behavior (r=-122, N=453, p=0.0009). Pearson’s correlation between adolescents’ sexual knowledge and sexual behavior shows that there is a positive significant but strong relationship between adolescent’s sexual knowledge and their sexual behavior (r=0.967, N=453, p<0.05). The results also show that adolescent’s preference for sexual content in television informs them about their sexuality, development and sexual health. The descriptive and inferential analysis of data revealed that the interaction among adolescent sexual belief, knowledge and adolescents’ preference of sexual in television and its resultant effect on adolescent sexual behavior is apparent because sexual belief and norms about sex of an adolescent can induce his television preference of sexual content on television. The study concludes that exposure to sexual content in television can impact on adolescent sexual behaviour. There is no doubt that the actual outcome of television viewing and adolescent sexual behavior remains controversial because adolescent sexual behavior is multifaceted and multi-dimensional. Since behavior is learned overtime, the frequency of exposure and nature of sexual content viewed overtime induces and hastens sexual activity.Keywords: adolescent sexual behavior, Nigeria, sexual belief, sexual content, sexual knowledge, television preference
Procedia PDF Downloads 3921354 Increment of Panel Flutter Margin Using Adaptive Stiffeners
Authors: S. Raja, K. M. Parammasivam, V. Aghilesh
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Fluid-structure interaction is a crucial consideration in the design of many engineering systems such as flight vehicles and bridges. Aircraft lifting surfaces and turbine blades can fail due to oscillations caused by fluid-structure interaction. Hence, it is focussed to study the fluid-structure interaction in the present research. First, the effect of free vibration over the panel is studied. It is well known that the deformation of a panel and flow induced forces affects one another. The selected panel has a span 300mm, chord 300mm and thickness 2 mm. The project is to study, the effect of cross-sectional area and the stiffener location is carried out for the same panel. The stiffener spacing is varied along both the chordwise and span-wise direction. Then for that optimal location the ideal stiffener length is identified. The effect of stiffener cross-section shapes (T, I, Hat, Z) over flutter velocity has been conducted. The flutter velocities of the selected panel with two rectangular stiffeners of cantilever configuration are estimated using MSC NASTRAN software package. As the flow passes over the panel, deformation takes place which further changes the flow structure over it. With increasing velocity, the deformation goes on increasing, but the stiffness of the system tries to dampen the excitation and maintain equilibrium. But beyond a critical velocity, the system damping suddenly becomes ineffective, so it loses its equilibrium. This estimated in NASTRAN using PK method. The first 10 modal frequencies of a simple panel and stiffened panel are estimated numerically and are validated with open literature. A grid independence study is also carried out and the modal frequency values remain the same for element lengths less than 20 mm. The current investigation concludes that the span-wise stiffener placement is more effective than the chord-wise placement. The maximum flutter velocity achieved for chord-wise placement is 204 m/s while for a span-wise arrangement it is augmented to 963 m/s for the stiffeners location of ¼ and ¾ of the chord from the panel edge (50% of chord from either side of the mid-chord line). The flutter velocity is directly proportional to the stiffener cross-sectional area. A significant increment in flutter velocity from 218m/s to 1024m/s is observed for the stiffener lengths varying from 50% to 60% of the span. The maximum flutter velocity above Mach 3 is achieved. It is also observed that for a stiffened panel, the full effect of stiffener can be achieved only when the stiffener end is clamped. Stiffeners with Z cross section incremented the flutter velocity from 142m/s (Panel with no stiffener) to 328 m/s, which is 2.3 times that of simple panel.Keywords: stiffener placement, stiffener cross-sectional area, stiffener length, stiffener cross sectional area shape
Procedia PDF Downloads 2921353 Projects and Limits of Memory Engineering: A Case of Lithuanian Partisan War
Authors: Mingaile Jurkute, Vilnius University
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The memory of the Lithuanian partisan war (1944-1953) underwent extremely dramatic transformations. During this war, the image of the resistance and a partisan was one of the key elements of Lithuanian identity. Its importance is evidenced by the extremely large legacy of songs about partisans, no other topic has collected so much folklore in Lithuania. In the Soviet years, this resistance was practically forced to be forgotten. Terror and Soviet laws have forced people to stop talking about the events, even in the family circle. In addition, the Soviets created their own propaganda story, reinterpreting the Lithuanian partisan war, presenting partisans as bandits who brutally tortured and murdered locals. But even in the Soviet years, the memory could neither be completely suppressed, nor completely transformed into wishful shape. The analysis of fiction and cinema shows that the traumatic memory of real events rushed to the surface, thus transforming the very propagandistic narrative. After the restoration of the Republic of Lithuania in 1990, the Lithuanian partisan war was gradually returned to the central place of Lithuanian history. After 2014 the nationalist heroic narrative about Lithuanian partisans became the central narrative of modern Lithuanian history. Nevertheless, interviews I conducted in Lithuanian villages reveal that the memory of local communities and families preserves quite different experiences that do not fit into neither the Soviet narrative nor the heroic one. Such experiences include, for example, partisan violence against local families. This paper is about the efforts of two political ideologies (the Soviet and the Lithuanian patriotic) to use the history of the Lithuanian partisans for their own needs, and the attempts of small communities (mostly families) to resist these efforts. The research reveals that family memory, even when opposed to aggressive state memory policies, can preserve counter-narratives by exploiting unexpected objects beyond the control of the state, such as nature and wildlife. Basically, the paper analyses the limits of the instrumentalization of memory, even by extremely aggressive political regimes.Keywords: collective memory, post-memory, violence, military conflict, family memory
Procedia PDF Downloads 921352 Transport Properties of Alkali Nitrites
Authors: Y. Mateyshina, A.Ulihin, N.Uvarov
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Electrolytes with different type of charge carrier can find widely application in different using, e.g. sensors, electrochemical equipments, batteries and others. One of important components ensuring stable functioning of the equipment is electrolyte. Electrolyte has to be characterized by high conductivity, thermal stability, and wide electrochemical window. In addition to many advantageous characteristic for liquid electrolytes, the solid state electrolytes have good mechanical stability, wide working range of temperature range. Thus search of new system of solid electrolytes with high conductivity is an actual task of solid state chemistry. Families of alkali perchlorates and nitrates have been investigated by us earlier. In literature data about transport properties of alkali nitrites are absent. Nevertheless, alkali nitrites MeNO2 (Me= Li+, Na+, K+, Rb+ and Cs+), except for the lithium salt, have high-temperature phases with crystal structure of the NaCl-type. High-temperature phases of nitrites are orientationally disordered, i.e. non-spherical anions are reoriented over several equivalents directions in the crystal lattice. Pure lithium nitrite LiNO2 is characterized by ionic conductivity near 10-4 S/cm at 180°C and more stable as compared with lithium nitrate and can be used as a component for synthesis of composite electrolytes. In this work composite solid electrolytes in the binary system LiNO2 - A (A= MgO, -Al2O3, Fe2O3, CeO2, SnO2, SiO2) were synthesized and their structural, thermodynamic and electrical properties investigated. Alkali nitrite was obtained by exchange reaction from water solutions of barium nitrite and alkali sulfate. The synthesized salt was characterized by X-ray powder diffraction technique using D8 Advance X-Ray Diffractometer with Cu K radiation. Using thermal analysis, the temperatures of dehydration and thermal decomposition of salt were determined.. The conductivity was measured using a two electrode scheme in a forevacuum (6.7 Pa) with an HP 4284A (Precision LCR meter) in a frequency range 20 Hz < ν < 1 MHz. Solid composite electrolytes LiNO2 - A A (A= MgO, -Al2O3, Fe2O3, CeO2, SnO2, SiO2) have been synthesized by mixing of preliminary dehydrated components followed by sintering at 250°C. In the series of nitrite of alkaline metals Li+-Cs+, the conductivity varies not monotonically with increasing radius of cation. The minimum conductivity is observed for KNO2; however, with further increase in the radius of cation in the series, the conductivity tends to increase. The work was supported by the Russian Foundation for Basic research, grant #14-03-31442.Keywords: conductivity, alkali nitrites, composite electrolytes, transport properties
Procedia PDF Downloads 3191351 A Molecular Dynamic Simulation Study to Explore Role of Chain Length in Predicting Useful Characteristic Properties of Commodity and Engineering Polymers
Authors: Lokesh Soni, Sushanta Kumar Sethi, Gaurav Manik
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This work attempts to use molecular simulations to create equilibrated structures of a range of commercially used polymers. Generated equilibrated structures for polyvinyl acetate (isotactic), polyvinyl alcohol (atactic), polystyrene, polyethylene, polyamide 66, poly dimethyl siloxane, poly carbonate, poly ethylene oxide, poly amide 12, natural rubber, poly urethane, and polycarbonate (bisphenol-A) and poly ethylene terephthalate are employed to estimate the correct chain length that will correctly predict the chain parameters and properties. Further, the equilibrated structures are used to predict some properties like density, solubility parameter, cohesive energy density, surface energy, and Flory-Huggins interaction parameter. The simulated densities for polyvinyl acetate, polyvinyl alcohol, polystyrene, polypropylene, and polycarbonate are 1.15 g/cm3, 1.125 g/cm3, 1.02 g/cm3, 0.84 g/cm3 and 1.223 g/cm3 respectively are found to be in good agreement with the available literature estimates. However, the critical repeating units or the degree of polymerization after which the solubility parameter showed saturation were 15, 20, 25, 10 and 20 respectively. This also indicates that such properties that dictate the miscibility of two or more polymers in their blends are strongly dependent on the chosen polymer or its characteristic properties. An attempt has been made to correlate such properties with polymer properties like Kuhn length, free volume and the energy term which plays a vital role in predicting the mentioned properties. These results help us to screen and propose a useful library which may be used by the research groups in estimating the polymer properties using the molecular simulations of chains with the predicted critical lengths. The library shall help to obviate the need for researchers to spend efforts in finding the critical chain length needed for simulating the mentioned polymer properties.Keywords: Kuhn length, Flory Huggins interaction parameter, cohesive energy density, free volume
Procedia PDF Downloads 1931350 Approaching the Spatial Multi-Objective Land Use Planning Problems at Mountain Areas by a Hybrid Meta-Heuristic Optimization Technique
Authors: Konstantinos Tolidis
Abstract:
The mountains are amongst the most fragile environments in the world. The world’s mountain areas cover 24% of the Earth’s land surface and are home to 12% of the global population. A further 14% of the global population is estimated to live in the vicinity of their surrounding areas. As urbanization continues to increase in the world, the mountains are also key centers for recreation and tourism; their attraction is often heightened by their remarkably high levels of biodiversity. Due to the fact that the features in mountain areas vary spatially (development degree, human geography, socio-economic reality, relations of dependency and interaction with other areas-regions), the spatial planning on these areas consists of a crucial process for preserving the natural, cultural and human environment and consists of one of the major processes of an integrated spatial policy. This research has been focused on the spatial decision problem of land use allocation optimization which is an ordinary planning problem on the mountain areas. It is a matter of fact that such decisions must be made not only on what to do, how much to do, but also on where to do, adding a whole extra class of decision variables to the problem when combined with the consideration of spatial optimization. The utility of optimization as a normative tool for spatial problem is widely recognized. However, it is very difficult for planners to quantify the weights of the objectives especially when these are related to mountain areas. Furthermore, the land use allocation optimization problems at mountain areas must be addressed not only by taking into account the general development objectives but also the spatial objectives (e.g. compactness, compatibility and accessibility, etc). Therefore, the main research’s objective was to approach the land use allocation problem by utilizing a hybrid meta-heuristic optimization technique tailored to the mountain areas’ spatial characteristics. The results indicates that the proposed methodological approach is very promising and useful for both generating land use alternatives for further consideration in land use allocation decision-making and supporting spatial management plans at mountain areas.Keywords: multiobjective land use allocation, mountain areas, spatial planning, spatial decision making, meta-heuristic methods
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