Search results for: contrast enhanced ultrasound

Authors: Shu-Chuan Liao, Chia-Ti Chang, Ko-Shao Chen

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Titanium and its alloy are widely used in many fields such as dentistry or orthopaedics. Due to their high strength low elastic modulus that chemical inertness and bio inert. The micro-arc oxidation used to formation a micro porous ceramic oxide layer film on Titanium surface and also to improve the resistance corrosion. For improving the biocompatibility, micro-arc oxidation surfaces bio-inert need to introduce reactive group. We introduced boundary layer by used plasma enhanced chemical vapor deposition of hexamethyldisilazane (HMDS) and organic active layer by UV light graft reactive monomer acrylic acid (AAc) therefore we can immobilize Chondroitin sulphate on surface easily by crosslinking EDC/NHS. The surface properties and composition of the modified layer were measured by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) and water contact angle. Water contact angle of the plasma-treated Ti surface decreases from 60° to 38°, which is an indication of hydrophilicity. The results of electrochemical polarization analysis showed that the sample plasma treated at micro-arc oxidation after plasma treatment has the best corrosion resistance. The result showed that we can immobilize chondroitin sulfate successful by a series of modification and MTT assay indicated the biocompatibility has been improved in this study.

Keywords: MAO, plasma, graft polymerization, biomedical application

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Authors: Heval Serhat Uluk, Sam M. Dakka, Kuldeep Singh, Richard Jefferson-Loveday

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This paper will focus on the suitability of a trapped vortex combustor as a candidate for gas turbine combustor objectives to minimize pressure drop across the combustor and investigate aerodynamic performance. Non-reacting simulation of axisymmetric cavity trapped vortex combustors were simulated to investigate the pressure drop for various cavity aspect ratios of 0.3, 0.6, and 1 and for air mass flow rates of 14 m/s, 28 m/s, and 42 m/s. A numerical study of an axisymmetric trapped vortex combustor was carried out by using two-dimensional and three-dimensional computational domains. A comparison study was conducted between Reynolds Averaged Navier Stokes (RANS) k-ε Realizable with enhanced wall treatment and RANS k-ω Shear Stress Transport (SST) models to find the most suitable turbulence model. It was found that the k-ω SST model gives relatively close results to experimental outcomes. The numerical results were validated and showed good agreement with the experimental data. Pressure drop rises with increasing air mass flow rate, and the lowest pressure drop was observed at 0.6 cavity aspect ratio for all air mass flow rates tested, which agrees with the experimental outcome. A mixing enhancement study showed that 30-degree angle air injectors provide improved fuel-air mixing.

Keywords: aerodynamic, computational fluid dynamics, propulsion, trapped vortex combustor

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Authors: Iftikhar Ahmad, Abulhakim Almajid

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Alumina (Al2O3) is an attractive structural ceramic however; brittleness turns Al2O3 down for advanced applications. Development of multi-phase phase ceramics systems is promising to curtail the brittleness and the incorporation of strong/elastic graphene, as third phase, into dual phase (Al2O3-SiC) is striking for mechanical upgrading purpose. Thin graphene nanosheets (GNS) were prepared by thermal exfoliation process and reinforced into dual phase ceramic system. The hybrid nanocomposite was consolidated by novel HF-IH (high-frequency induction heating) sintering furnace at 1500 °C under 50 MPa in vacuum conditions. Structural features and grain size of the resulting nanocomposite were analyzed by SEM and TEM whilst the mechanical properties were assessed by microhardness and nanoindentation techniques. The fracture toughness of the hybrid nanocomposites was appraised by direct crack measurement method. Electron microscopic investigations confirmed the preparation of thin (< 10 nm) graphene nanosheets (GNS). HF-IH sintering route condensed the three-phase (GNS-Al2O3-SiC) hybrid nanocomposite system to > 99% relative densities. SEM of the hybrid nanocomposites fractured surfaces revealed even distribution of the nanocomposite constituents and changed in fracture-mode. Structurally, 88% grain reduction into hybrid nanocomposite was also obtained. Mechanically, enhanced fracture toughness (50%) and hardness (53%) were also achieved for hybrid nanocomposites were attained against bench marked monolithic Al2O3.

Keywords: alumina, graphene, hybrid nanocomposites, rapid sintering

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Authors: Shreya Saxena

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Background: Choledocholithiasis is a common complication of gallstone disease. Risk scoring systems exist to guide the need for further imaging or endoscopy in managing choledocholithiasis. We completed an audit to review the American Society for Gastrointestinal Endoscopy (ASGE) scoring system for prediction and management of choledocholithiasis against the current practice at a tertiary hospital to assess its utility in resource optimisation. We have now conducted a cost focused sub-analysis on patients categorized high-risk for choledocholithiasis according to the guidelines to determine any associated cost benefits. Method: Data collection from our prior audit was used to retrospectively identify thirteen patients considered high-risk for choledocholithiasis. Their ongoing management was mapped against the guidelines. Individual costs for the key investigations were obtained from our hospital financial data. Total cost for the different management pathways identified in clinical practice were calculated and compared against predicted costs associated with recommendations in the guidelines. We excluded the cost of laparoscopic cholecystectomy and considered a set figure for per day hospital admission related expenses. Results: Based on our previous audit data, we identified a77% positive predictive value for the ASGE risk stratification tool to determine patients at high-risk of choledocholithiasis. 47% (6/13) had an magnetic resonance cholangiopancreatography (MRCP) prior to endoscopic retrograde cholangiopancreatography (ERCP), whilst 53% (7/13) went straight for ERCP. The average length of stay in the hospital was 7 days, with an additional day and cost of £328.00 (£117 for ERCP) for patients awaiting an MRCP prior to ERCP. Per day hospital admission was valued at £838.69. When calculating total cost, we assumed all patients had admission bloods and ultrasound done as the gold standard. In doing an MRCP prior to ERCP, there was a 130% increase in cost incurred (£580.04 vs £252.04) per patient. When also considering hospital admission and the average length of stay, it was an additional £1166.69 per patient. We then calculated the exact costs incurred by the department, over a three-month period, for all patients, for key investigations or procedures done in the management of choledocholithiasis. This was compared to an estimate cost derived from the recommended pathways in the ASGE guidelines. Overall, 81% (£2048.45) saving was associated with following the guidelines compared to clinical practice. Conclusion: MRCP is the most expensive test associated with the diagnosis and management of choledocholithiasis. The ASGE guidelines recommend endoscopy without an MRCP in patients stratified as high-risk for choledocholithiasis. Our audit that focused on assessing the utility of the ASGE risk scoring system showed it to be relatively reliable for identifying high-risk patients. Our cost analysis has shown significant cost savings per patient and when considering the average length of stay associated with direct endoscopy rather than an additional MRCP. Part of this is also because of an increased average length of stay associated with waiting for an MRCP. The above data supports the ASGE guidelines for the management of high-risk for choledocholithiasis patients from a cost perspective. The only caveat is our small data set that may impact the validity of our average length of hospital stay figures and hence total cost calculations.

Keywords: cost-analysis, choledocholithiasis, risk stratification tool, general surgery

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Authors: Florence Malongane, Lyndy J. McGaw, Legesse K. Debusho, Fhatuwani N. Mudau

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Rooibos (Aspalathus linearis (Burm.f.) R.Dahlgren), honeybush (Cyclopia Vent. species), bush tea (Athrixia phylicoides DC.) and special tea (Monsonia burkeana) are traditionally consumed herbal teas in South Africa. The volatile and sensory qualities of rooibos and honeybush tea have previously been described although there is a dearth of information regarding the sensory attributes and volatile compounds analysis of special tea and bush tea. The objective of this study was to describe the sensory properties, compare the differences in descriptive sensory analysis (DSA) and volatile compounds of bush tea, special, rooibos, honeybush and the blend of bush tea with special, honeybush and rooibos in a 1:1 ratio and subsequently to determine the influence of blending bush tea with other herbal teas. DSA was used to assess the sensory attributes of the teas while gas chromatography–mass spectrometry (GC-MS) was used to quantitatively determine the volatile components of the teas. Rooibos tea and honeybush tea had an overall sweet-caramel, honey-sweet, perfume floral and woody aroma with slight astringency, consistent with the taste and aftertaste attributes. In contrast, bush tea and special tea depicted green-cut grass, dry green herbal, cooked spinach aroma as well as taste and aftertaste characteristics. GC-MS analyses revealed that the seven tea samples had similar major volatiles, including 2-furanmethanol, 2-methoxy-4-vinylphenol, acetic acid, D-limonene terpene and phytol. Cluster analysis revealed that the sweet and woody flavour of honeybush and rooibos were ascribed to the presence of á-myrcene, phenylethyl alcohol, phytol and vanillin. The bitter, medicinal flavour attributes of special tea were attributed to (-)-carvone. Blending of bush tea with rooibos and honeybush tea toned down its aversive flavour components, typically the bitter, green-cut grass and herbal properties, thus minimising the possibility of consumer aversion.

Keywords: bush tea, rooibos tea, honeybush tea, sensory, volatile compounds

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Authors: Bal Chandra Yadav, Rakesh K. Sonker, Anjali Sharma, Punit Tyagi, Vinay Gupta, Monika Tomar

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In the present study, ZnO doped SnO2 thin films of various compositions were deposited on the surface of a corning substrate by dropping the two sols containing the precursors for composite (ZSO) with subsequent heat treatment. The sensor materials used for selective detection of nitrogen dioxide (NO2) were designed from the correlation between the sensor composition and gas response. The available NO2 sensors are operative at very high temperature (150-800 °C) with low sensing response (2-100) even in higher concentrations. Efforts are continuing towards the development of NO2 gas sensor aiming with an enhanced response along with a reduction in operating temperature by incorporating some catalysts or dopants. Thus in this work, a novel sensor structure based on ZSO nanocomposite has been fabricated using chemical route for the detection of NO2 gas. The structural, surface morphological and optical properties of prepared films have been studied by using X-ray diffraction (XRD), Atomic force microscopy (AFM), Transmission electron microscope (TEM) and UV-visible spectroscopy respectively. The effect of thickness variation from 230 nm to 644 nm of ZSO composite thin film has been studied and the ZSO thin film of thickness ~ 460 nm was found to exhibit the maximum gas sensing response ~ 2.1×103 towards 20 ppm NO2 gas at an operating temperature of 90 °C. The average response and recovery times of the sensor were observed to be 3.51 and 6.91 min respectively. Selectivity of the sensor was checked with the cross-exposure of vapour CO, acetone, IPA, CH4, NH3 and CO2 gases. It was found that besides the higher sensing response towards NO2 gas, the prepared ZSO thin film was also highly selective towards NO2 gas.

Keywords: ZSO nanocomposite thin film, ZnO tetrapod structure, NO2 gas sensor, sol-gel method

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Authors: A. Asgharzadeh, M. Maroufi

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5G mobile communication system has drawn more and more attention. The 5G system needs to provide three different types of services, including enhanced Mobile BroadBand (eMBB), massive machine-type communication (mMTC), and ultra-reliable and low-latency communication (URLLC). Universal Filtered Multi-Carrier (UFMC), Filter Bank Multicarrier (FBMC), and Filtered Orthogonal Frequency Division Multiplexing (f-OFDM) are suggested as a well-known candidate waveform for the coming 5G system. Themachine-to-machine (M2M) communications are one of the essential applications in 5G, and it involves exchanging of concise messages with a very short latency. However, in UFMC systems, the subcarriers are grouped into subbands but f-OFDM only one subband covers the entire band. Furthermore, in FBMC, a subband includes only one subcarrier, and the number of subbands is the same as the number of subcarriers. This paper mainly discusses the performance of UFMC with different parameters for the UFMC system. Also, paper shows that UFMC is the best choice outperforming OFDM in any case and FBMC in case of very short packets while performing similarly for long sequences with channel estimation techniques for Interleave Division Multiple Access (IDMA) systems.

Keywords: universal filtered multi-carrier technique, UFMC, interleave division multiple access, IDMA, fifth-generation, subband

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Authors: Shashank Kumar, Mansi Chandra, Ujjawal Singh, Parth Gupta, Rishi Ram, Arnab Sarkar

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Milk is one of the basic and primary sources of food and energy as we start consuming milk from birth. Hence, milk quality and purity and checking the concentration of its constituents become necessary steps. Considering the importance of the purity of milk for human health, the following study has been carried out to simultaneously detect and quantify the different adulterants like urea and starch in milk with the help of a paper-based microfluidic device integrated with a smartphone. The detection of the concentration of urea and starch is based on the principle of colorimetry. In contrast, the fluid flow in the device is based on the capillary action of porous media. The microfluidic channel proposed in the study is equipped with a specialized detection zone, and it employs a colorimetric indicator undergoing a visible color change when the milk gets in touch or reacts with a set of reagents which confirms the presence of different adulterants in the milk. In our proposed work, we have used iodine to detect the percentage of starch in the milk, whereas, in the case of urea, we have used the p-DMAB. A direct correlation has been found between the color change intensity and the concentration of adulterants. A calibration curve was constructed to find color intensity and subsequent starch and urea concentration. The device has low-cost production and easy disposability, which make it highly suitable for widespread adoption, especially in resource-constrained settings. Moreover, a smartphone application has been developed to detect, capture, and analyze the change in color intensity due to the presence of adulterants in the milk. The low-cost nature of the smartphone-integrated paper-based sensor, coupled with its integration with smartphones, makes it an attractive solution for widespread use. They are affordable, simple to use, and do not require specialized training, making them ideal tools for regulatory bodies and concerned consumers.

Keywords: paper based microfluidic device, milk adulteration, urea detection, starch detection, smartphone application

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Authors: Liat Kulik

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The main goal of the present study was to examine gender differences in the variables that explain the experience of role conflict and well-being among Jewish working fathers and mothers in the Israel. The experience of work-family conflict arises from simultaneous pressures from the work and family domains that are mutually incompatible. In light of the expansion of women's role set following the addition of paid employment outside of the home, most of the studies dealing with the impact of multiple roles on well-being have been conducted among women. However, changes in gender roles in recent years have also affected men's role set, as reflected in the terms ‘new men’ and ‘new fathers’. Based on structural equation modeling, the study examined gender differences in variables that explain the experience of two types of role conflict – family interferes with work (FIW) and work interferes with family (WIF), as well as with the sense of well-being (positive and negative affect) among 611 employed Jewish mothers and fathers in Israel. The findings revealed that for women, both FIW and WIF conflict correlated negatively with well-being, whereas for men, a negative correlation with well-being was found only in the case of FIW conflict. For both men and women, egalitarian gender role ideology correlated with the dimension of positive effect, but the correlation was stronger for men. The findings highlight the contribution of egalitarian gender role ideology to alleviating the experience of role conflict and improving the emotional well-being of both men and women. Contrary to expectations, social support contributed more to mitigating negative effect among men than women. On the whole, the findings highlight the changes that men have experienced in the work-family system. In sum, the research findings shed new light on the masculine image in terms of the experience of FIW conflict. In contrast to the prevailing assumption that FIW role conflict is predominant among women, the findings of this study indicate that today, this type of role conflict is experienced equally by men and women whereas WIF conflict is predominant among men. Furthermore, contrary to expectations, levels of perceived social support were found to be similar for men and women, and men benefited from it even more than women did.

Keywords: FIW conflict, WIF conflict, social support, egalitarian gender role ideology, overload

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Authors: Rara Wulan Anggareni, Narita Putri, Riski Septianing Astuti

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Breastfeeding is a key to prevent mortality and morbidity in children. It is also the second highest risk responsible for Disability Adjusted Life Years (DALYs) among children below five years old. UNICEF estimates that during 1995 – 2003, there are only about 38% infants in developing countries who get to be exclusively breastfed during the first six months of their lives. According to Demography and Health Survey in Indonesia 2007, breastfeed practice rate still considered as low which is about 41%. One of the factors causing the low breastfeed practice rate in Indonesia is the anxiety and postpartum depression, and also the weanling dilemma in which mother feels that her breastmilk cannot suffice infant needs. Those factors finally resulting into low or even stopped production of breastmilk. Breastmilk production can be enhanced by consuming food containing phytosterol and lactogoga effect. Food with the highest phytosterol level is Sauropus androgynus (L.) Merr leaf (merr leaf). In this study, we made alternative food which named Chocomerr for breastfeeding mothers. Chocomerr consists of merr leaves which have lactogoga effect and chocolate for relaxation. Based on organoleptic tests conducted towards 2 age groups, which are 18 – 21 and 25 – 40 years old, this product gets good acceptance in taste, texture, and colour categories. Chocomerr can be used as an alternative way for increasing breastmilk production to aim for the decreasing number of DALYs among children aged under 5 years old.

Keywords: breastfeeding, increasing, chocolate, merr leaves

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Authors: Poteet Frances, Glovinski Ira

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INTRODUCTION: The interoceptive nervous system continuously senses chemical and anatomical changes and helps you recognize, understand, and feel what’s going on inside your body so it is important for energy regulation, memory, affect, and sense of self. A newborn needs predictable routines rather than confusion/chaos to make connections between internal experiences and emotions. AIM: Current legal protocols of removing babies from drug-addicted mothers impact the critical window of bonding. The newborn’s brain is social and the attachment process influences a child’s development which begins immediately after birth through nourishment, comfort, and protection. DESCRIPTION: Our project aims to educate drug-addicted mothers, and medical, nursing, and social work professionals on interoceptive concepts and practices to sustain the mother/newborn relationship. A mother’s interoceptive knowledge predicts children’s emotion regulation and social skills in middle childhood. CONCLUSION: When mothers develop an awareness of their inner bodily sensations, they can self-regulate and be emotionally available to co-regulate (support their newborn during distressing emotions and sensations). Our project has enhanced relationship preservation (mothers understand how their presence matters) and the overall mother/newborn connection.

Keywords: drug-addiction, interoception, legal, mothers, newborn, self-regulation

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Authors: L. P. Gomes, G. F. Araújo, Y. M. L. Cordeiro, C. T. Andrade, E. M. Del Aguila, V. M. F. Paschoalin

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The application of nanoscale materials and nanostructures is an emerging area, these since materials may provide solutions to technological and environmental challenges in order to preserve the environment and natural resources. To reach this goal, the increasing demand must be accompanied by 'green' synthesis methods. Chitosan is a natural, nontoxic, biopolymer derived by the deacetylation of chitin and has great potential for a wide range of applications in the biological and biomedical areas, due to its biodegradability, biocompatibility, non-toxicity and versatile chemical and physical properties. Chitosan also presents high antimicrobial activities against a wide variety of pathogenic and spoilage microorganisms. Ultrasonication is a common tool for the preparation and processing of polymer nanoparticles. It is particularly effective in breaking up aggregates and in reducing the size and polydispersity of nanoparticles. High-intensity ultrasonication has the potential to modify chitosan molecular weight and, thus, alter or improve chitosan functional properties. The aim of this study was to evaluate the influence of sonication intensity and time on the changes of commercial chitosan characteristics, such as molecular weight and its potential antibacterial activity against Gram-negative bacteria. The nanoparticles (NPs) were produced from two commercial chitosans, of medium molecular weight (CS-MMW) and low molecular weight (CS-LMW) from Sigma-Aldrich®. These samples (2%) were solubilized in 100 mM sodium acetate pH 4.0, placed on ice and irradiated with an ultrasound SONIC ultrasonic probe (model 750 W), equipped with a 1/2" microtip during 30 min at 4°C. It was used on constant duty cycle and 40% amplitude with 1/1s intervals. The ultrasonic degradation of CS-MMW and CS-LMW were followed up by means of ζ-potential (Brookhaven Instruments, model 90Plus) and dynamic light scattering (DLS) measurements. After sonication, the concentrated samples were diluted 100 times and placed in fluorescence quartz cuvettes (Hellma 111-QS, 10 mm light path). The distributions of the colloidal particles were calculated from the DLS and ζ-potential are measurements taken for the CS-MMW and CS-LMW solutions before and after (CS-MMW30 and CS-LMW30) sonication for 30 min. Regarding the results for the chitosan sample, the major bands can be distinguished centered at Radius hydrodynamic (Rh), showed different distributions for CS-MMW (Rh=690.0 nm, ζ=26.52±2.4), CS-LMW (Rh=607.4 and 2805.4 nm, ζ=24.51±1.29), CS-MMW30 (Rh=201.5 and 1064.1 nm, ζ=24.78±2.4) and CS-LMW30 (Rh=492.5, ζ=26.12±0.85). The minimal inhibitory concentration (MIC) was determined using different chitosan samples concentrations. MIC values were determined against to E. coli (106 cells) harvested from an LB medium (Luria-Bertani BD™) after 18h growth at 37 ºC. Subsequently, the cell suspension was serially diluted in saline solution (0.8% NaCl) and plated on solid LB at 37°C for 18 h. Colony-forming units were counted. The samples showed different MICs against E. coli for CS-LMW (1.5mg), CS-MMW30 (1.5 mg/mL) and CS-LMW30 (1.0 mg/mL). The results demonstrate that the production of nanoparticles by modification of their molecular weight by ultrasonication is simple to be performed and dispense acid solvent addition. Molecular weight modifications are enough to provoke changes in the antimicrobial potential of the nanoparticles produced in this way.

Keywords: antimicrobial agent, chitosan, green production, nanoparticles

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Authors: Natascha Reich

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In colonial Peru, the Spanish crown relied on religious orders, most notably Dominicans, Franciscans, and Jesuits, for accelerating processes of colonization. The dissemination of Christian art, architecture, and music, and most of all, the agency of indigenous people in their production played a key role in facilitating the acceptance of the new religious and political system. Current research on Peruvian colonial music culture and its role as a vehicle for colonization focus on practices in urban centers. The lack of (written) primary sources seems to turn rural areas into a less attractive research territory for musicologists. This paper advocates for a more inclusive approach. By investigating seventeenth-century pipe organs as material remains of Franciscan missionary music culture, it shows how reactions to colonial forces and Christianization in rural Andean locations could follow tendencies different from those in urban areas. Indigenous musicians in cities tried to 'fit' into the European system in order to be accepted by the ruling Spanish elite. By contrast, the indigenous-built pipe organs in the rural Peruvian Colca-Valley show distinctly native-Andean influences. This paper argues that this syncretism can be interpreted as hybridity in Homi K. Bhabha’s sense, as a means of the colonized to undermine the power of the colonizer and to advance reactionary politics. Not only will it show the necessity of considering rural Peruvian music history in modern scholarship for arriving at a more complete picture of colonial culture, but it will also evidence the advantages of a mixed-methodology approach. Historical organology, combined with concepts from ethnomusicology and post-colonial studies, proves as a useful tool in the absence or scarcity of written primary sources.

Keywords: cultural hybridity, music as reactionary politics, Latin American pipe organs, Peruvian colonial music

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Authors: Ji-Won Park, Jong-Wha Kim

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Triploid L. lancifolium have a wide geographic distribution. By contrast, diploid L. lancifolium have limited distributions in the islands and coastal regions of the South and West Korean Peninsula and northern Tsushima Island, Japan. L. lancifolium diploids and triploids are not sympatrically distributed with other lily species or ploidy lines in West Sea and South Sea Islands of the Korean Peninsula. This observation raises the following questions: 'Why have autotriploid L. lancifolium never been observed in those isolated islands?', 'What mechanism excludes the occurrence of autotriploids, if they arise?'. To determine the occurrence and survival of triploid plants in natural diploid populations of tiger lily (Lilium lancifolium), ploidy analysis was conducted on natural open-pollinated seeds produced from plants grown on isolated islands, and on hybrid seeds produced by artificial crossing between plant populations originating on different Korean islands. Normal seeds were classified into five grades depending on the ratio of embryo/endosperm lengths, including 5/5, 4/5, 3/5, 2/5, and 1/5. Triploids were not observed among seedlings produced from natural open pollinations on isolated islands. Triploids were detected only in seedlings of underdeveloped seed grades(3/5 and 2/5) from artificial crosses between populations from different isolated islands. The triploid occurrence frequency was calculated as 0.0 for natural open-pollinated seedlings and 0.000582 for artificial crosses(6 triploids from 10,303 seedlings). Triploids were produced from crosses between isolated populations located at least 70 km apart; no triploids were detected in inter-population crosses of plants originating on the same islands. Triploid seedlings have very low viability in soil. We analyzed factors affecting triploid occurrence and survival in natural diploid populations of L. lancifolium. The results suggest that triploids originate from fertilization between plants that are genetically isolated due to geographical isolation and/or genotypic differences.

Keywords: Lilium lancifolium, autotriploid, natural population, genetic distance, 2n female gamete

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Authors: Vera Sovkova, Andrea Mickova, Matej Buzgo, Karolina Vocetkova, Eva Filova, Evzen Amler

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PCL (poly-ε-caprolactone) nanofibrous scaffolds with adhered liposomes were prepared and tested as a possible drug delivery system for various synthetic growth factors. TGFβ, bFGF, and IGF-I have been shown to increase hMSC (human mesenchymal stem cells) proliferation and to induce hMSC differentiation. Functionalized PCL nanofibers were prepared with synthetic growth factors encapsulated in liposomes adhered to them in three different concentrations. Other samples contained PCL nanofibers with adhered, free synthetic growth factors. The synthetic growth factors free medium served as a control. The interaction of liposomes with the PCL nanofibers was visualized by SEM, and the release kinetics were determined by ELISA testing. The potential of liposomes, immobilized on the biodegradable scaffolds, as a delivery system for synthetic growth factors, and as a suitable system for MSCs adhesion, proliferation and differentiation in vitro was evaluated by MTS assay, dsDNA amount determination, confocal microscopy, flow cytometry and real-time PCR. The results showed that the growth factors adhered to the PCL nanofibers stimulated cell proliferation mainly up to day 11 and that subsequently their effect was lower. By contrast, the release of the lowest concentration of growth factors from liposomes resulted in gradual proliferation of MSCs throughout the experiment. Moreover, liposomes, as well as free growth factors, stimulated type II collagen production, which was confirmed by immunohistochemical staining using monoclonal antibody against type II collagen. The results of this study indicate that growth factors enriched liposomes adhered to surface of PCL nanofibers could be useful as a drug delivery instrument for application in short timescales, be combined with nanofiber scaffolds to promote local and persistent delivery while mimicking the local microenvironment. This work was supported by project LO1508 from the Ministry of Education, Youth and Sports of the Czech Republic

Keywords: drug delivery, growth factors, hMSC, liposomes, nanofibres

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Authors: M. Tomaschko

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The integration of technology in educational settings has gained a lot of interest. Especially the use of mobile devices and accompanying mobile applications can offer great potentials to complement traditional education with new technologies and enrich students’ learning in various ways. Nevertheless, the usability of the deployed mathematics application is an indicative factor to exploit the full potential of technology enhanced learning because directing cognitive load toward using an application will likely inhibit effective learning. For this reason, the purpose of this research study is the identification of possible usability issues of the mobile GeoGebra Graphing Calculator application. Therefore, eye tracking in combination with task scenarios, think aloud method, and a SUS questionnaire were used. Based on the revealed usability issues, the mobile application was iteratively redesigned and assessed in order to verify the success of the usability improvements. In this paper, the identified usability issues are presented, and recommendations on how to overcome these concerns are provided. The main findings relate to the conception of a mathematics keyboard and the interaction design in relation to an equation editor, as well as the representation of geometrical construction tools. In total, 12 recommendations were formed to improve the usability of a mobile graphing calculator application. The benefit to be gained from this research study is not only the improvement of the usability of the existing GeoGebra Graphing Calculator application but also to provide helpful hints that could be considered from designers and developers of mobile math applications.

Keywords: GeoGebra, graphing calculator, math education, smartphone, usability

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Authors: Rosalie Menon, Angela Reid

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Building integrated photovoltaic systems with air collectors (hybrid PV-T) have proved successful however there are few examples of their application in the UK. The opportunity to pull heat from behind the PV system to contribute to a building’s heating system is an efficient use of waste energy and its potential to improve the performance of the PV array is well documented. As part of Glasgow School of Art’s estate expansion, the purchase and redevelopment of an existing 1950’s college building was used as a testing vehicle for the hybrid PV-T system as an integrated element of the upper floor and roof. The primary objective of the feasibility study was to determine if hybrid PV-T was technically and financially suitable for the refurbished building. The key consideration was whether the heat recovered from the PV panels (to increase the electrical efficiency) can be usefully deployed as a heat source within the building. Dynamic thermal modelling (IES) and RetScreen Software were used to carry out the feasibility study not only to simulate overshadowing and optimise the PV-T locations but also to predict the atrium temperature profile; predict the air load for the proposed new 4 No. roof mounted air handling units and to predict the dynamic electrical efficiency of the PV element. The feasibility study demonstrates that there is an energy reduction and carbon saving to be achieved with each hybrid PV-T option however the systems are subject to lengthy payback periods and highlights the need for enhanced government subsidy schemes to reward innovation with this technology in the UK.

Keywords: building integrated, photovoltatic thermal, pre-heat air, ventilation

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Authors: Akram Boubakri, Fethi Choubeni, Tan Hoa Vuong, Jacques David

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The control of electromagnetic waves is a key aim of several researches over the past decade. In this regard, Metamaterials have shown a strong ability to manipulate the electromagnetic waves on a subwavelength scales thanks to its unconventional properties that are not available in natural materials such as negative refraction index, super imaging and invisibility cloaking. Metalenses were used to avoid some drawbacks presented by conventional lenses since focusing with conventional lenses suffered from the limited resolution because they were only able to focus the propagating wave component. Nevertheless, Metalenses were able to go beyond the diffraction limit and enhance the resolution not only by collecting the propagating waves but also by restoring the amplitude of evanescent waves that decay rapidly when going far from the source and that contains the finest details of the image. Metasurfaces have many mechanical advantages over three-dimensional metamaterial structures especially the ease of fabrication and a smaller required volume. Those structures have been widely used for antenna performance improvement and to build flat metalenses. In this work, we showed that a well-designed metasurface lens operating at the frequency of 5.9GHz, has efficiently enhanced the radiation characteristics of a patch antenna and can be used for WLAN applications (IEEE 802.11 a). The proposed metasurface lens is built with a geometrically modified unit cells which lead to a change in the response of the lens at different position and allow the control of the wavefront beam of the incident wave thanks to the gradient refractive index.

Keywords: focusing, gradient index, metasurface, metalens, WLAN Applications

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Authors: Ororho Maureen Ekpelezie

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This study investigates language educators' perceptions and experiences regarding AI-driven personalized teacher training modules in Awka South, Anambra State, Nigeria. Utilizing a stratified random sampling technique, 25 schools across various educational levels were selected to ensure a representative sample. A total of 1000 questionnaires were distributed among language teachers in these schools, focusing on assessing their perceptions and experiences related to AI-driven personalized teacher training. With an impressive response rate of 99.1%, the study garnered valuable insights into language teachers' attitudes towards AI-driven personalized teacher training and its effectiveness in enhancing language teaching competence. The quantitative analysis revealed predominantly positive perceptions towards AI-driven personalized training modules, indicating their efficacy in addressing individual learning needs. However, challenges were identified in the long-term retention and transfer of AI-enhanced skills, underscoring the necessity for further refinement of personalized training approaches. Recommendations stemming from these findings emphasize the need for continued refinement of training methodologies and the development of tailored professional development programs to alleviate educators' concerns. Overall, this research enriches discussions on the integration of AI technology in teacher training and professional development, with the aim of bolstering language teaching competence and effectiveness in educational settings.

Keywords: language teacher training, AI-driven personalized learning, professional development, language teaching competence, personalized teacher training

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Authors: Maryam Kiani

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In order to enhance the efficiency and stability of an electrocatalyst for formic acid electro-oxidation reaction (FAOR), we developed a method to create Pt/Ni nanoparticles with carbon black. These nanoparticles were prepared using a simple impregnation reduction technique. During the observation, it was found that the nanoparticles had a spherical shape. Additionally, the average particle size remained consistent, falling within the range of about 4 nm. This approach aimed to obtain a loaded Pt-based electrocatalyst that would exhibit improved performance and stability when used in FAOR applications. By utilizing the impregnation reduction method and incorporating Ni nanoparticles along with Pt, we sought to enhance the catalytic properties of the material. By incorporating Ni atoms into the Pt structure, the electronic properties of Pt are modified, resulting in a delay in the chemisorption of harmful CO intermediate species. This modification also promotes the dehydrogenation pathway of the formic acid oxidation reaction (FAOR). Through electrochemical analysis, it has been observed that the Pt3Ni-C catalyst exhibits enhanced performance in FAOR compared to traditional Pt catalysts. This means that the addition of Ni atoms improves the efficiency and effectiveness of the Pt3Ni-C catalyst in facilitating the FAOR process. Overall, the utilization of these alloy nanoparticles as electrocatalysts represents a significant advancement in fuel cell technology.

Keywords: electrocatalyst, impregnation reduction method, formic acid electro-oxidation reaction, fuel cells

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Authors: F. Z. Benabid, F. Zouai, A. Douibi, D. Benachour

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These Fluorinated polymers and polyacrylics have known a wide use in the field of historical monuments. PVDF provides a great easiness to processing, a good UV resistance and good chemical inertia. Although the quality of physical characteristics of the PMMA and its low price with a respect to PVDF, its deterioration against UV radiations limits its use as protector agent for the stones. On the other hand, PVDF/PMMA blend is a compromise of a great development in the field of architectural restoration, since it is the best method in term of quality and price to make new polymeric materials having enhanced properties. Films of different compositions based on the two polymers within an adequate solvent (DMF) were obtained to perform an exposition to artificial ageing and to the salted fog, a spectroscopic analysis (FTIR and UV) and optical analysis (refractive index). Based on its great interest in the field of building, a variety of standard tests has been elaborated for the first time at the central laboratory of ENAP (Souk-Ahras) in order to evaluate our blend performance. The obtained results have allowed observing the behavior of the different compositions of the blend under various tests. The addition of PVDF to PMMA enhances the properties of this last to know the exhibition to the natural and artificial ageing and to the saline fog. On the other hand, PMMA enhances the optical properties of the blend. Finally, 70/30 composition of the blend is in concordance with results of previous works and it is the adequate proportion for an eventual application.

Keywords: blend, PVDF, PMMA, preservation, historic monuments

Procedia PDF Downloads 295

Authors: D. Anderlini, G. Wallis

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Background: The number of people experiencing stroke is steadily increasing due to changes in diet and lifestyle, to longer life expectancy resulting in older population, to higher survival rates as a consequence of improvements during the acute phase. This study considers what risk factors might contribute to delayed entry to hospital for treatment. Methods: We analyzed data from 2472 patients admitted to the Stroke Unit of the Royal Brisbane Women's Hospital, Australia, between 2002 to 2011. Results: Previous studies have reported that factors which can contribute to delay include the patient’s age, the time of day, physical location, visit the GP instead of going to the emergency, means of transport, severity of symptoms and type of stroke. Contrary to findings of other studies, we found a strong correlation between side of lesion and delay in admission: patients with right hemisphere lesions had an average delay of 3.78 days, while patients with left hemisphere lesions had an average delay of 1.49 days. Damage to the right hemisphere generally ends in motor impairment in the non-dominant hand and no speech impediment. In contrast, left hemisphere lesions can result in deficit to; dominant hand function and aphasia which will be noticed even if their impact on performance is relatively minor. A finding which goes against many previous studies, is the fact that women get to the hospital much sooner than men, showing an average delay of 0.92 days in women vs. 3.36 days in men. Conclusion: Acute surgical-pharmacological therapies are most effective if applied immediately after stroke. Hence delays to admission can be crucial to the degree of recovery. The tendency of patients to overlook symptoms of right hemisphere lesion should be the target of information campaigns both for the general public and GPs. Why do men go to hospital so late? We don't know yet! Nevertheless an awareness plan specifically direct to male population should be on the agenda of Health Departments.

Keywords: gender, admission delay, stroke location, bioinformatics, biomedicine

Procedia PDF Downloads 213

Authors: Mina Mortazavi

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The common approach in the construction industry for restraint requirements in existing structures or new constructions is to have Non-Structural Components (NSCs) assembled and installed on-site by different MEP subcontractors. This leads to a lack of coordination and higher costs, construction time, and complications due to inaccurate building information modelling (BIM) systems. Introducing NSCs to a consistent BIM system from the beginning of the design process and considering their seismic loads in the analysis and design process can improve coordination and reduce costs and time. One solution is to use prefabricated mounts with attached MEPs delivered as an integral module. This eliminates the majority of coordination complications and reduces design and installation costs and time. An advanced approach is to have as many NSCs as possible installed in the same prefabricated module, which gives the structural engineer the opportunity to consider the involved component weights and locations in the analysis and design of the prefabricated support. This efficient approach eliminates coordination and access issues, leading to enhanced quality control. This research will focus on the existing literature on modular sub-assemblies that are integrated with architectural and structural components. Modular MEP systems take advantage of the precision provided by BIM tools to meet exact requirements and achieve a buildable design every time. Modular installations that include MEP systems provide efficient solutions for the installation of MEP services or components.

Keywords: building services, modularisation, prefabrication, integral building design

Procedia PDF Downloads 56

Authors: Mei Teng Woo, Keith Davids, Jarmo Liukkonen, Jia Yi Chow, Timo Jaakkola

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Wearable garments such as tapes, compression garments, and braces could improve proprioception and reduced postural sway. The aim of this study was to examine the effects of wearable garments on postural regulation in a sample of community-dwelling elderly individuals, aged 65 years. It was hypothesized that wearable garments such as socks would provide stimulation to lower leg mechanoreceptors, and help participants achieve better postural regulation. Participants (N=63) performed a 30-s Romberg balance test protocol under four conditions (barefoot; wearing commercial socks; wearing clinical compression socks; wearing non-clinical compression socks), in a counterbalanced order, with four levels of performance difficulty: (1) standing on a stable surface with open eyes (SO); (2) a stable surface with closed eyes (SC); (3) a foam surface with open eyes (FO); and (4) a foam surface with closed eyes (FC). Centre of pressure (CoP) measurements included postural sway area (C90 area), trace length (TL) and sway velocity. Thirty-five participants (55.6%) showed positive effects of wearing the socks (responded group). In the responded group, it was revealed that socks showed significant differences in SO, SC and FO conditions for the two CoP measurements - TL and sway velocity (p < 0.05). In contrast, in the non-responded group, barefoot condition significantly decreased the TL and velocity in the SO condition. From the positive effects observed in the responded group, it is possible that wearable garments provide sensory cues that could interact with a biological cueing system to enhance performance in the postural regulation system. This study suggests that individuals respond to the socks treatments differently and future research should be undertaken to examine the factors that benefited the responded group of participants.

Keywords: community-dwelling, elderly adults, postural regulation, wearable garments

Procedia PDF Downloads 322

Authors: Saksham

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Concrete's versatility and affordability make it a highly competitive building material capable of meeting diverse requirements. However, the increasing demands placed on structures and the need for enhanced durability and performance have driven the development of distinct cementitious materials and concrete composites. One significant aspect of this advancement is the utilization of waste materials from industries, such as fly ash, to improve concrete's properties. Fly ash, a byproduct of coal combustion can enhance concrete's strength and durability while reducing environmental impact. Additionally, steel fibers can enhance concrete's toughness and crack resistance, contributing to improved structural performance. The experimental study aims to optimize the proportion of ingredients in M30-grade concrete, incorporating fly ash and steel fibers. By varying fly ash content (10% to 30%) and steel fiber dosage (0% to 1.5%), the research seeks to determine the optimal combination for achieving the desired compressive strength. Two sets of experiments are conducted: one focusing on varying fly ash content while keeping steel fiber dosage constant, and the other focusing on varying steel fiber dosage while keeping other parameters fixed. Through systematic testing, molding, curing, and evaluation according to specified standards, the research aims to analyze the impact of fly ash and steel fibers on concrete's compressive strength. The findings have the potential to inform engineers about optimized concrete mix designs that balance performance, cost-effectiveness, and sustainability, advancing toward more resilient and environmentally friendly building practices.

Keywords: concrete, sustainability, durability, compressive strength

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Authors: Mohammad H. Al-Sayah, Khalid Jarrah, Soleiman Hisaindee

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Hydrophobic sorbents are usually used to remove oil spills from water surfaces. In this study, the hydrophilic fibers of natural cotton were chemically modified with a solvent-free process to modify them into hydrophobic fibers that can remove oil from water surfaces. The cellulose-based fibers of cotton were reacted with trichlorosilanes through gas-solid reaction in a dry chamber. Cotton fibers were exposed to vapors of four different chloroalkylsilanes at room temperature for 24 hours. The chlorosilanes were namely trichloromethylsilane, dichlorodimethyl silane, butyltrichlorosilane, and trichloro (3,3,3-trifluoropropyl) silane. The modified cotton fibers were characterized by IR-spectroscopy, thermogravimetric analysis (TGA) and Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy (SEM-EDS). The degree of substitution for each of the grafted alkyl groups was in the range between 0.1 and 0.3 per glucose residue. As a result of sialylation, the cotton fibers became hydrophobic; this was reflected by water contact-angle measurements of the fibers which increased from zero for the unmodified cotton to above 100 degrees for the modified fibers. In addition, the adsorption capacity of the fibers for oil from water surfaces increased by about five times that of the unmodified cotton reaching 18 g oil/g of cotton modified by dimethyl substituted silyl ethers. The optimal fiber-oil contact time and temperature for adsorption were 10 mins at 25°C, respectively. Therefore, the efficacy of cotton fibers to remove oil spills from contaminated water surfaces was significantly enhanced by using a simple solvent-free and environment-friendly process.

Keywords: gas-solid silyl reaction, modified cellulose, solvent-free, oil pollution, cotton

Procedia PDF Downloads 153

Authors: T. N. M. El Sebai, A. A. Khattab, Wafaa M. Abd-El Rahim, H. Moawad

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Fungal mutant strains have produced cellulase and xylanase enzymes, and have induced high hydrolysis with enhanced of rice straw. The mutants were obtained by exposing Penicillium strain to UV-light treatments. Screening and selection after treatment with UV-light were carried out using cellulolytic and xylanolytic clear zones method to select the hypercellulolytic and hyperxylanolytic mutants. These mutants were evaluated for their cellulase and xylanase enzyme production as well as their abilities for biodegradation of rice straw. The mutant 12 UV/1 produced 306.21% and 209.91% cellulase and xylanase, respectively, as compared with the original wild type strain. This mutant showed high capacity of rice straw degradation. The effectiveness of tested mutant strain and that of wild strain was compared in relation to enhancing the composting process of rice straw and animal manures mixture. The results obtained showed that the compost product of inoculated mixture with mutant strain (12 UV/1) was the best compared to the wild strain and un-inoculated mixture. Analysis of the composted materials showed that the characteristics of the produced compost were close to those of the high quality standard compost. The results obtained in the present work suggest that the combination between rice straw and animal manure could be used for enhancing the composting process of rice straw and particularly when applied with fungal decomposer accelerating the composting process.

Keywords: rice straw, composting, UV mutants, Penicillium

Procedia PDF Downloads 265

Authors: Fatima Muhammad Shitu

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This study seeks to investigate the effect of the keyword strategy on lexico–semantic acquisition, recognition, retention and comprehension in an ESL context. The aim of the study is to determine whether the keyword strategy can be used to enhance acquisition. As a quasi- experimental research, the objectives of the study include: To determine the extent to which the scores obtained by the subjects, who were trained on the use of the keyword strategy for acquisition, differ at the pre-tests and the post–tests and also to find out the relationship in the scores obtained at these tests levels. The sample for the study consists of 300 hundred undergraduate ESL Students in the Federal College of Education, Kano. The seventy-five lexical items for acquisition belong to the lexical field category known as register, and they include Medical, Agriculture and Photography registers (MAP). These were divided in the ratio twenty-five (25) lexical items in each lexical field. The testing technique was used to collect the data while the descriptive and inferential statistics were employed for data analysis. For the purpose of testing, the two kinds of tests administered at each test level include the WARRT (Word Acquisition, Recognition, and Retention Test) and the CCPT (Cloze Comprehension Passage Test). The results of the study revealed that there are significant differences in the scores obtained between the pre-tests, and the post–tests and there are no correlations in the scores obtained as well. This implies that the keyword strategy has effectively enhanced the acquisition of the lexical items studied.

Keywords: keyword, lexical, semantics, strategy

Procedia PDF Downloads 293

Authors: M. Varmaziar

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Magnesium (Mg) is an essential mineral that plays a crucial role in the human body. Certain types of foods, including nuts, grains, fruits, vegetables, and whole grains, are rich sources of magnesium. Mg serves as an essential cofactor for numerous enzymatic reactions, including energy metabolism, cellular growth, glycolysis, and protein synthesis. The Mg-ATP complex serves as an energy source and is vital for many physiological functions, including nerve conduction, muscle contraction, and blood pressure regulation. Despite the vital role of magnesium in energy metabolism, maintaining adequate magnesium intake is often overlooked among the general population and athletes. The aim of this study was to investigate the effect of magnesium supplementation on the physical activities of field athletes. Field athletes were divided into two groups: those who consumed magnesium supplements and those who received a placebo. These two groups received either 500 mg of magnesium oxide or a placebo daily for 8 weeks. At the beginning and end of the study, athletes completed ISI questionnaires and physical activity assessments. Nutritional analyses were performed using N4 software, and statistical analyses were conducted using SPSS19 software. The results of this study revealed a significant difference between the two study groups. Athletes who received magnesium supplements experienced less fatigue related to field athletic activities and muscle soreness. In contrast, athletes who received the placebo reported more significant fatigue and muscle soreness. A concerning finding in these results is that the performance of athletic activities may be at risk with low magnesium levels. Therefore, magnesium is essential for maintaining health and plays a crucial role in athletic performance. Consuming a variety of magnesium-rich foods ensures that individuals receive an adequate amount of this essential nutrient in their diet. The consumption of these foods improves performance parameters in athletic exercises.

Keywords: athletic performance, effect, field athletes, magnesium supplement

Procedia PDF Downloads 66

Authors: Evridiki Papachristou, Nikolaos Bilalis

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Imagine an apparel industry where fashion design does not begin with a paper-and-pen drawing which is then translated into pattern and later to a 3D model where the designer tries out different fabrics, colours and contrasts. Instead, imagine a fashion designer in the future who produces that initial fashion drawing in a three-dimensional space and won’t leave that environment until the product is done, communicating his/her ideas with the entire development team in true to life 3D. Three-dimensional (3D) technology - while well established in many other industrial sectors like automotive, aerospace, architecture and industrial design, has only just started to open up a whole range of new opportunities for apparel designers. The paper will discuss the process of 3D simulation technology enhanced by high quality visualization of data and its capability to ensure a massive competitiveness in the market. Secondly, it will underline the most frequent problems & challenges that occur in the process chain when various partners in the production of textiles and apparel are working together. Finally, it will offer a perspective of how the Virtual Prototyping Technology will make the global textile and apparel industry change to a level where designs will be visualized on a computer and various scenarios modeled without even having to produce a physical prototype. This state-of-the-art 3D technology has been described as transformative and“disruptive”comparing to the process of the way apparel companies develop their fashion products today. It provides the benefit of virtual sampling not only for quick testing of design ideas, but also reducing process steps and having more visibility.A so called“digital asset” that can be used for other purposes such as merchandising or marketing.

Keywords: 3D visualization, apparel, virtual prototyping, prototyping technology

Procedia PDF Downloads 562