Search results for: gold catalyst
231 Poly(Ethylene Glycol)-Silicone Containing Phase Change Polymer for Thermal Energy Storage
Authors: Swati Sundararajan, , Asit B. Samui, Prashant S. Kulkarni
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The global energy crisis has led to extensive research on alternative sources of energy. The gap between energy supply and demand can be met by thermal energy storage techniques, of which latent heat storage is most effective in the form of phase change materials (PCMs). Phase change materials utilize latent heat absorbed or released over a narrow temperature range of the material undergoing phase transformation, to store energy. The latent heat can be utilized for heating or cooling purposes. It can also be used for converting to electricity. All these actions amount to minimizing the load on electricity demand. These materials retain this property over repeated number of cycles. Different PCMs differ in the phase change temperature and the heat storage capacities. Poly(ethylene glycol) (PEG) was cross-linked to hydroxyl-terminated poly(dimethyl siloxane) (PDMS) in the presence of cross-linker, tetraethyl orthosilicate (TEOS) and catalyst, dibutyltin dilaurate. Four different ratios of PEG and PDMS were reacted together, and the composition with the lowest PEG concentration resulted in the formation of a flexible solid-solid phase change membrane. The other compositions are obtained in powder form. The enthalpy values of the prepared PCMs were studied by using differential scanning calorimetry and the crystallization properties were analyzed by using X-ray diffraction and polarized optical microscopy. The incorporation of silicone moiety was expected to reduce the hydrophilic character of PEG, which was evaluated by measurement of contact angle. The membrane forming ability of this crosslinked polymer can be extended to several smart packaging, building and textile applications. The detailed synthesis, characterization and performance evaluation of the crosslinked polymer blend will be incorporated in the presentation.Keywords: phase change materials, poly(ethylene glycol), poly(dimethyl siloxane), thermal energy storage
Procedia PDF Downloads 354230 Preparation and Characterization of CuFe2O4/TiO2 Photocatalyst for the Conversion of CO2 into Methanol under Visible Light
Authors: Md. Maksudur Rahman Khan, M. Rahim Uddin, Hamidah Abdullah, Kaykobad Md. Rezaul Karim, Abu Yousuf, Chin Kui Cheng, Huei Ruey Ong
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A systematic study was conducted to explore the photocatalytic reduction of carbon dioxide (CO2) into methanol on TiO2 loaded copper ferrite (CuFe2O4) photocatalyst under visible light irradiation. The phases and crystallite size of the photocatalysts were characterized by X-ray diffraction (XRD) and it indicates CuFe2O4 as tetragonal phase incorporation with anatase TiO2 in CuFe2O4/TiO2 hetero-structure. The XRD results confirmed the formation of spinel type tetragonal CuFe2O4 phases along with predominantly anatase phase of TiO2 in the CuFe2O4/TiO2 hetero-structure. UV-Vis absorption spectrum suggested the formation of the hetero-junction with relatively lower band gap than that of TiO2. Photoluminescence (PL) technique was used to study the electron–hole (e−/h+) recombination process. PL spectra analysis confirmed the slow-down of the recombination of electron–hole (e−/h+) pairs in the CuFe2O4/TiO2 hetero-structure. The photocatalytic performance of CuFe2O4/TiO2 was evaluated based on the methanol yield with varying amount of TiO2 over CuFe2O4 (0.5:1, 1:1, and 2:1) and changing light intensity. The mechanism of the photocatalysis was proposed based on the fact that the predominant species of CO2 in aqueous phase were dissolved CO2 and HCO3- at pH ~5.9. It was evident that the CuFe2O4 could harvest the electrons under visible light irradiation, which could further be injected to the conduction band of TiO2 to increase the life time of the electron and facilitating the reactions of CO2 to methanol. The developed catalyst showed good recycle ability up to four cycles where the loss of activity was ~25%. Methanol was observed as the main product over CuFe2O4, but loading with TiO2 remarkably increased the methanol yield. Methanol yield over CuFe2O4/TiO2 was found to be about three times higher (651 μmol/gcat L) than that of CuFe2O4 photocatalyst. This occurs because the energy of the band excited electrons lies above the redox potentials of the reaction products CO2/CH3OH.Keywords: photocatalysis, CuFe2O4/TiO2, band-gap energy, methanol
Procedia PDF Downloads 244229 Reactions of 4-Aryl-1H-1,2,3-Triazoles with Cycloalkenones and Epoxides: Synthesis of 2,4- and 1,4-Disubstituted 1,2,3-Triazoles
Authors: Ujjawal Kumar Bhagat, Kamaluddin, Rama Krishna Peddinti
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The Huisgen’s 1,3-dipolar [3+2] cycloaddition of organic azides and alkynes often give the mixtures of both the regioisomers 1,4- and 1,5- disubstituted 1,2,3-triazoles. Later, in presence of metal salts (click chemistry) such as copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) was used for the synthesis of 1,4-disubstituted 1,2,3-triazoles as a sole products regioselectively. Also, the ‘click reactions’ of Ruthenium-catalyzed azides-alkynes cycloaddition (RuAAC) is used for the synthesis of 1,5-disubstituted 1,2,3-triazoles as a single isomer. The synthesis of 1,4- and 1.5-disubstituted 1,2,3-triazoles has become the gold standard of ‘click chemistry’ due to its reliability, specificity, and biocompatibility. The 1,4- and 1,5-disubstituted 1,2,3-triazoles have emerged as one of the most powerful entities in the varieties of biological properties like antibacterial, antitubercular, antitumor, antifungal and antiprotozoal activities. Some of the 1,4,5-trisubstituted 1,2,3-triazoles exhibit Hsp90 inhibiting properties. The 1,4-disubstituted 1,2,3-triazoles also play a big role in the area of material sciences. The triazole-derived oligomeric, polymeric structures are the potential materials for the preparation of organic optoelectronics, silicon elastomers and unimolecular block copolymers. By the virtue of hydrogen bonding and dipole interactions, the 1,2,3-triazole moiety readily associates with the biological targets. Since, the 4-aryl-1H-1,2,3-triazoles are stable entities, they are chemically robust and very less reactive. In this regard, the addition of 4-aryl-1H-1,2,3-triazoles as nucleophiles to α,β-unsaturated carbonyls and nucleophilic substitution with the epoxides constitutes a powerful and challenging synthetic approach for the generation of disubstituted 1,2,3-triazoles. Herein, we have developed aza-Michael addition of 4-aryl-1H-1,2,3-triazoles to 2-cycloalken-1-ones in the presence of an organic base (DABCO) in acetonotrile solvent leading to the formation of disubstituted 1,2,3-triazoles. The reaction provides 1,4-disubstituted triazoles, 3-(4-aryl-1H-1,2,3-triazol-1-yl)cycloalkanones in major amount along with 1,5-disubstituted 1,2,3-triazoles, minor regioisomers with excellent combined chemical yields (upto99%). The nucleophilic behavior of 4-aryl-1H-1,2,3-triazoles was also tested in the ring opening of meso-epoxides in the presence of organic bases (DABCO/Et3N) in acetonotrile solvent furnishing the two regioisomers1,4- and 1,5-disubstituted 1,2,3-triazoles. Thus, the novelty of this methodology is synthesis of diversified disubstituted 1,2,3-triazoles under metal free condition.The results will be presented in detail.Keywords: aza-Michael addition, cycloalkenones, epoxides, triazoles
Procedia PDF Downloads 322228 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 128227 Clinical Value of 18F-FDG-PET Compared with CT Scan in the Detection of Nodal and Distant Metastasis in Urothelial Carcinoma or Bladder Cancer
Authors: Mohammed Al-Zubaidi, Katherine Ong, Pravin Viswambaram, Steve McCombie, Oliver Oey, Jeremy Ong, Richard Gauci, Ronny Low, Dickon Hayne
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Objective: Lymph node involvement along with distant metastasis in a patient with invasive bladder cancer determines the disease survival, therefeor, it is an essential determinant of the therapeutic management and outcome. This retrospective study aims to determine the accuracy of FDG PET scan in detecting lymphatic involvement and distant metastatic urothelial cancer compared to conventional CT staging. Method: A retrospective review of 76 patients with UC or BC who underwent surgery or confirmatory biopsy that was staged with both CT and 18F-FDG-PET (up to 8 weeks apart) between 2015 and 2020. Fifty-sevenpatients (75%) had formal pelvic LN dissection or biopsy of suspicious metastasis. 18F-FDG-PET reports for positive sites were qualitative depending on SUV Max. On the other hand, enlarged LN by RECIST criteria 1.1 (>10 mm) and other qualitative findings suggesting metastasis were considered positive in CT scan. Histopathological findings from surgical specimens or image-guided biopsies were considered the gold standard in comparison to imaging reports. 18F-FDG-avid or enlarged pelvic LNs with surgically proven nodal metastasis were considered true positives. Performance characteristics of 18F-FDG-PET and CT, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value (PPV), were calculated. Results: Pelvic LN involvement was confirmed histologically in 10/57 (17.5%) patients. Sensitivity, specificity, PPV and NPV of CT for detecting pelvic LN metastases were 41.17% (95% CI:18-67%), 100% (95% CI:90-100%) 100% (95% CI:59-100%) and 78.26% (95% CI:64-89%) respectively. Sensitivity, specificity, PPV and NPV of 18F-FDG-PET for detecting pelvic LN metastases were 62.5% (95% CI:35-85%), 83.78% (95% CI:68-94%), 62.5% (95% CI:35-85%), and 83.78% (95% CI:68-94%) respectively. Pre-operative staging with 18F-FDG-PET identified the distant metastatic disease in 9/76 (11.8%) patients who were occult on CT. This retrospective study suggested that 18F-FDG-PET may be more sensitive than CT for detecting pelvic LN metastases. 7/76 (9.2%) patients avoided cystectomy due to 18F-FDG-PET diagnosed metastases that were not reported on CT. Conclusion: 18F-FDG-PET is more sensitive than CT for pelvic LN metastases, which can be used as the standard modality of bladder cancer staging, as it may change the treatment by detecting lymph node metastasis that was occult in CT. Further research involving randomised controlled trials comparing the diagnostic yield of 18F-FDG-PET and CT in detecting nodal and distant metastasis in UC or BC is warranted to confirm our findings.Keywords: FDG PET, CT scan, urothelial cancer, bladder cancer
Procedia PDF Downloads 121226 Eco-Products in Day-to-Day Life: A Catalyst for Achieving Sustainability
Authors: Rani Fernandez
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As global concerns regarding environmental degradation and climate change intensify, the imperative for sustainable living has never been more critical. This research delves into the role of eco-products in everyday life as a pivotal strategy for achieving sustainability. The study investigates the awareness, adoption, and impact of eco-friendly products on individual and community levels. The research employs a mixed-methods approach, combining surveys, interviews, and case studies to explore consumer perceptions, behaviours, and motivations surrounding the use of eco-products. Additionally, life cycle assessments are conducted to evaluate the environmental footprint of selected eco-products, shedding light on their tangible contributions to sustainability. The findings reveal the diverse range of eco-products available in the market, from biodegradable packaging to energy-efficient appliances, and the extent to which consumers integrate these products into their daily routines. Moreover, the research examines the challenges and opportunities associated with widespread adoption, considering factors such as cost, accessibility, and efficacy. In addition to individual consumption patterns, the study investigates the broader societal impact of eco-product integration. It explores the potential for eco-products to drive systemic change by influencing supply chains, corporate practices, and government policies. The research highlights successful case studies of communities or businesses that have effectively incorporated eco-products, providing valuable insights into scalable models for sustainability. Ultimately, this research contributes to the discourse on sustainable living by elucidating the pivotal role of eco-products in shaping environmentally conscious behaviours. By understanding the dynamics of eco-product adoption, policymakers, businesses, and individuals can collaboratively work towards a more sustainable future. The implications of this study extend beyond academia, informing practical strategies for fostering a global shift towards sustainable consumption and production.Keywords: eco-friendly, sustainablity, environment, climate change
Procedia PDF Downloads 40225 Linking Access to Land, Tenure Security with Food Sufficiency of Tenants/Landless or Small Holder Farmers of Parsa District
Authors: Subesh Panta
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The land is a one of the major boosting factors of production for the agricultural country like Nepal where access to land has been a major source of livelihood of tenants and small farmers. But there is an absence of secure land tenure arrangement which drastically affect the overall production of farmers leading towards food insecurity. Sharecropping is practiced in Nepal especially in tarai region from early period, but there is the gap in the academic study whether the sharecropping has benefitted tenant farmers and make them food sufficient or not. This study attempts to find out the food sufficiency among the tenant households. The research was carried in the three VDCs of Parsa district -Paterwa (Sugauli), Jitpur and Nirchuta. A total of 111 households were determined as the sample size from each of the three VDCs was randomly visited for interview in the study. The size of land rent-in was found to be very small and fragmented. At the same time, the land tenure security was not found to be secured among the tenants. Due to lack of land tenure security, on one hand tenants and small farmers were not found to be motivated to investment in agriculture as they need to share fifty percent of their production with the land owners, and on other hand land owners were also not interested in investing as they have other alternative sources of livelihood rather than agriculture. In conclusion, the study highpoint that the crop production and food sufficiency level of the tenants’ farmers of the Parsa district are decreasing. Many tenants’ farmers are seeking alternative opportunities for livelihood rather than sharecropping due to insecure land tenure, feudalistic practice, lack of storage for agriculture production, lack of proper agro-market. The situation is such that, if no action is taken timely, there may be a situation that we will have to depend on imports for all the food requirements. Thus, the study discloses that the sharecropping could act as catalyst for ensuring food sufficiency for all, if proper land tenure police are promoted to tenants/small farmers with legal titles to their land or promoted with sustainable agriculture methods.Keywords: agriculture, food sufficiency, land, tenant farmes
Procedia PDF Downloads 235224 Carbon-Encapsulated Iron Nanoparticles for Hydrogen Sulfide Removal
Authors: Meriem Abid, Erika Oliveria-Jardim, Andres Fullana, Joaquin Silvestre-Albero
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The rapid industrial development associated with the increase of volatile organic compounds (VOCs) has seriously impacted the environment. Among VOCs, hydrogen sulfide (H₂S) is known as a highly toxic, malodorous, flammable, and corrosive gas, which is emitted from diverse chemical processes, including industrial waste-gas streams, natural gas processing, and biogas purification. The high toxicity, corrosively, and very characteristic odor threshold of H2S call for urgent development of efficient desulfurization processes from the viewpoint of environmental protection and resource regeneration. In order to reduce H₂S emissions, effective technologies for have been performed. The general method of H₂S removal included amine aqueous solution, adsorption process, biological methods, and fixed-bed solid catalytic oxidation processes. Ecologically and economically, low-temperature direct oxidation of H₂S to elemental sulfur using catalytic oxidation is the preferred approach for removing H₂S-containing gas streams. A large number of catalysts made from carbon, metal oxides, clay, and others, have been studied extensively for this application. In this sense, activated carbon (AC) is an attractive catalyst for H₂S removal because it features a high specific surface area, diverse functional groups, low cost, durability, and high efficiency. It is interesting to stand out that AC is modified using metal oxides to promote the efficiency of H₂S removal and to enhance the catalytic performance. Based on these premises, the main goal of the present study is the evaluation of the H₂S adsorption performance in carbon-encapsulated iron nanoparticles obtained from an olive mill, thermally treated at 600, 800 and 1000 ºC temperatures under anaerobic conditions. These results anticipate that carbon-encapsulated iron nanoparticles exhibit a promising performance for the H₂S removal up to 360 mg/g.Keywords: H₂S removal, catalytic oxidation, carbon encapsulated iron, olive mill wastewater
Procedia PDF Downloads 87223 TiO₂ Deactivation Process during Photocatalytic Ethanol Degradation in the Gas Phase
Authors: W. El-Alami, J. Araña, O. González Díaz, J. M. Doña Rodríguez
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The efficiency of the semiconductor TiO₂ needs to be improved to be an effective tool for pollutant removal. To improve the efficiency of this semiconductor, it is necessary to deepen the knowledge of the processes that take place on its surface. In this sense, the deactivation of the catalyst is one of the aspects considered relevant. In order to study this point, the processes of deactivation of TiO₂ during the gas phase degradation of ethanol have been studied. For this, catalysts with only the anatase phase (SA and PC100) and catalysts with anatase and rutile phases (P25 and P90) have been selected. In order to force the deactivation processes, different cycles have been performed, adding ethanol gas but avoiding the degradation of acetates to determine their effect on the process. The surface concentration of fluorine on the catalysts was semi-quantitatively determined by EDAX analysis. The photocatalytic experiments were done with four commercial catalysts (P25, SA, P90, and PC100) and the two fluoride catalysts indicated above. The interaction and photocatalytic degradation of ethanol were followed by Fourier transform infrared spectroscopy (FTIR). EDAX analysis has revealed the presence of sodium on the surface of fluorinated catalysts. In FTIR studies, it has been observed that the acetates adsorbed on the anatase phase in P25 and P90 give rise to electron transfer to surface traps that modify the electronic states of the semiconductor. These deactivation studies have also been carried out with fluorinated P25 and SA catalysts (F-P25 and F-SA) which have observed similar electron transfers but in the opposite direction during illumination. In these materials, it has been observed that the electrons present in the surface traps, as a consequence of the interaction Ti-F, react with the holes, causing a change in the electronic states of the semiconductor. In this way, deactivated states of these materials have been detected by different electron transfer routes. It has been identified that acetates produced from the degradation of ethanol in P25 and P90 are probably hydrated on the surface of the rutile phase. In the catalysts with only the anatase phase (SA and PC100), the deactivation is immediate if the acetates are not removed before adsorbing ethanol again. In F-P25 and F-SA has been observed that the acetates formed react with the sodium ions present on the surface and not with the Ti atoms because they are interacting with the fluorine.Keywords: photocatalytic degradation, ethanol, TiO₂, deactivation process, F-P25
Procedia PDF Downloads 74222 Challenges and Prospects of Preservation of Tangible Cultural Heritage Management: A Case Study in Lake Tana Islands, Ethiopia
Authors: Ayele Tamene
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Cultural heritage is the legacy of physical artifacts and intangible attributes of a group or society that are inherited from past generations, maintained in the present and bestowed for the benefit of future generations. Tangible heritage e includes buildings and historic places, monuments, artifacts, etc., which are considered worthy of preservation for the future. These include objects significant to the archaeology, architecture, science or technology of a specific culture. The research addressed the challenges and prospects of preservation of tangible cultural heritage management in Lake Tana islands; Amahara Regional State. Specifically, the research inquired the major factors which affected tangible cultural heritage management, investigated how communities successfully involved in tangible cultural heritage management, and described the contribution of cultural management to tourism development. It employed qualitative research approaches to grasp the existing condition in the study area. Major techniques of data gathering such as in-depth interview, observation/photographing and Focus Group Discussion (FGDs) were used. Related documents collected through secondary sources were examined and analyzed. In Lake Tana Islands precious heritages such as ancient religious manuscripts (written since 9th century), sacral wall paintings, gold and silver Crosses, crowns and prestigious clothes of the various kings of the medieval and the 19th century are found. The study indicated that heritages in Tana islands were affected by both natural and manmade problems. In Lake Tana Islands, movable heritages were looted several times by foreign aggressors, tourists, and local people who serve there. Some heritages were affected by visitors by their camera flash light and hand touch. Most heritages in the Tana islands lacked community ownership and preserved non- professionally which highly affected their originality and authenticity. Therefore, the local community and the regional government should work together in the preservation of these heritage sites and enhance their role for socio-economic development as a center of research and tourist destinations.Keywords: cultural heritages, heritage preservation, lake Tana heritages, non professional preservation tangible heritages
Procedia PDF Downloads 326221 MAOD Is Estimated by Sum of Contributions
Authors: David W. Hill, Linda W. Glass, Jakob L. Vingren
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Maximal accumulated oxygen deficit (MAOD), the gold standard measure of anaerobic capacity, is the difference between the oxygen cost of exhaustive severe intensity exercise and the accumulated oxygen consumption (O2; mL·kg–1). In theory, MAOD can be estimated as the sum of independent estimates of the phosphocreatine and glycolysis contributions, which we refer to as PCr+glycolysis. Purpose: The purpose was to test the hypothesis that PCr+glycolysis provides a valid measure of anaerobic capacity in cycling and running. Methods: The participants were 27 women (mean ± SD, age 22 ±1 y, height 165 ± 7 cm, weight 63.4 ± 9.7 kg) and 25 men (age 22 ± 1 y, height 179 ± 6 cm, weight 80.8 ± 14.8 kg). They performed two exhaustive cycling and running tests, at speeds and work rates that were tolerable for ~5 min. The rate of oxygen consumption (VO2; mL·kg–1·min–1) was measured in warmups, in the tests, and during 7 min of recovery. Fingerprick blood samples obtained after exercise were analysed to determine peak blood lactate concentration (PeakLac). The VO2 response in exercise was fitted to a model, with a fast ‘primary’ phase followed by a delayed ‘slow’ component, from which was calculated the accumulated O2 and the excess O2 attributable to the slow component. The VO2 response in recovery was fitted to a model with a fast phase and slow component, sharing a common time delay. Oxygen demand (in mL·kg–1·min–1) was determined by extrapolation from steady-state VO2 in warmups; the total oxygen cost (in mL·kg–1) was determined by multiplying this demand by time to exhaustion and adding the excess O2; then, MAOD was calculated as total oxygen cost minus accumulated O2. The phosphocreatine contribution (area under the fast phase of the post-exercise VO2) and the glycolytic contribution (converted from PeakLac) were summed to give PCr+glycolysis. There was not an interaction effect involving sex, so values for anaerobic capacity were examined using a two-way ANOVA, with repeated measures across method (PCr+glycolysis vs MAOD) and mode (cycling vs running). Results: There was a significant effect only for exercise mode. There was no difference between MAOD and PCr+glycolysis: values were 59 ± 6 mL·kg–1 and 61 ± 8 mL·kg–1 in cycling and 78 ± 7 mL·kg–1 and 75 ± 8 mL·kg–1 in running. Discussion: PCr+glycolysis is a valid measure of anaerobic capacity in cycling and running, and it is as valid for women as for men.Keywords: alactic, anaerobic, cycling, ergometer, glycolysis, lactic, lactate, oxygen deficit, phosphocreatine, running, treadmill
Procedia PDF Downloads 136220 Psychological Stress As A Catalyst For Multiple Sclerosis Progression: Clarifying Pathways From Neural Activation to Immune Dysregulation
Authors: Noah Emil Glisik
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Multiple sclerosis (MS) is a chronic, immune-mediated disorder characterized by neurodegenerative processes and a highly variable disease course. Recent research highlights a complex interplay between psychological stress and MS progression, with both acute and chronic stressors linked to heightened inflammatory activity, increased relapse risk, and accelerated disability. This review synthesizes findings from systematic analyses, cohort studies, and neuroimaging investigations to examine how stress contributes to disease dynamics in MS. Evidence suggests that psychological stress influences MS progression through neural and physiological pathways, including dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and heightened activity in specific brain regions, such as the insular cortex. Notably, functional MRI studies indicate that stress-induced neural activity may predict future atrophy in gray matter regions implicated in motor and cognitive function, thus supporting a neurobiological link between stress and neurodegeneration in MS. Longitudinal studies further associate chronic stress with reduced quality of life and higher relapse frequency, emphasizing the need for a multifaceted therapeutic approach that addresses both the physical and psychological dimensions of MS. Evidence from intervention studies suggests that stress management strategies, such as cognitive-behavioral therapy and mindfulness-based programs, may reduce relapse rates and mitigate lesion formation in MS patients. These findings underscore the importance of integrating stress-reducing interventions into standard MS care, with potential to improve disease outcomes and patient well-being. Further research is essential to clarify the causal pathways and develop targeted interventions that could modify the stress response in MS, offering an avenue to address disease progression and enhance quality of life.Keywords: multiple sclerosis, psychological stress, disease progression, neuroimaging, stress management
Procedia PDF Downloads 9219 Preparation and Characterization of Supported Metal Nanocrystal Using Simple Heating Method for Renewable Diesel Synthesis from Nyamplung Oil (Calophyllum inophyllum Oil)
Authors: Aida Safiera, Andika Dwi Rubyantoro, Muhammad Bagus Prakasa
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Indonesia’s needs of diesel oil each year are increasing and getting urge. However, that problems are not supported by the amount of oil production that still low and also influenced by the fact of oil reserve is reduced. Because of that, the government prefers to import from other countries than fulfill the needs of diesel. To anticipate that problem, development of fuel based on renewable diesel is started. Renewable diesel is renewable alternative fuel that is hydrocarbon derivative from decarbonylation of non-edible oil. Indonesia is rich with natural resources, including nyamplung oil (Calophyllum inophyllum oil) and zeolite. Nyamplung oil (Calophyllum inophyllum oil) has many stearic acids which are useful on renewable diesel synthesis meanwhile zeolite is cheap. Zeolite is many used on high temperature reaction and cracking process on oil industry. Zeolite also has advantages which are a high crystallization, surface area and pores. In this research, the main focus that becomes our attention is on preparation and characterization of metal nanocrystal. Active site that used in this research is Nickel Molybdenum (NiMo). The advantage of nanocrystal with nano scale is having larger surface area. The synthesis of metal nanocrystal will be done with conventional preparation modification method that is called simple heating. Simple heating method is a metal nanocrystal synthesis method using continuous media which is polymer liquid. This method is a simple method and produces a small particles size in a short time. Influence of metal nanocrystal growth on this method is the heating profile. On the synthesis of nanocrystal, the manipulated variables are temperature and calcination time. Results to achieve from this research are diameter size on nano scale (< 100 nm) and uniform size without any agglomeration. Besides that, the conversion of synthesis of renewable diesel is high and has an equal specification with petroleum diesel. Catalyst activities are tested by FT-IR and GC-TCD on decarbonylation process with a pressure 15 bar and temperature 375 °C. The highest conversion from this reaction is 35% with selectivity around 43%.Keywords: renewable diesel, simple heating, metal nanocrystal, NiMo, zeolite
Procedia PDF Downloads 230218 Exploring the Potential of Reduced Graphene Oxide/Polyaniline (rGo/PANI) Nanocomposites for High-Performance Supercapacitor Application
Authors: Ahmad Umar, Ahmed A. Ibrahim, Mohsen A. Alhamami
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This study introduces a facile synthesis method for synthesizing reduced graphene oxide (rGO) nanosheets with surface decoration of polyaniline (PANI). The resultant rGO@PANI nanocomposite (NC) exhibit substantial potential as advanced electrode materials for high-performance supercapacitors. The strategic integration of PANI onto the rGO surface serves dual purposes, effectively mitigating the agglomeration of rGO films and augmenting their utility in supercapacitor applications. The PANI coating manifests a highly porous and nanosized morphology, fostering increased surface area and optimized mass transport by reducing diffusion kinetics. The nanosized structure of PANI contributes to the maximization of active sites, thereby bolstering the efficacy of the nanocomposites for diverse applications. The inherent conductive nature of the rGO surface significantly expedites electron transport, thereby amplifying the overall electrochemical performance of the nanocomposites. To systematically evaluate the influence of PANI concentration on the electrode performance, varying concentrations of PANI were incorporated. Notably, an elevated PANI concentration was found to enhance the response owing to the unique morphology of PANI. Remarkably, the 5% rGO@PANI NC emerged as the most promising candidate, demonstrating exceptional response characteristics with a specific capacitance of 314.2 F/g at a current density of 1 A/g. Furthermore, this catalyst exhibits outstanding long-term stability, retaining approximately 92% of its capacitance even after enduring 4000 cycles. This research underscores the significance of the synergistic integration of rGO and PANI in the design of high-performance supercapacitors. The elucidation of the underlying mechanisms governing the improved electrochemical properties contributes to the fundamental understanding of nanocomposite behavior, thereby paving the way for the rational design of next-generation energy storage materials.Keywords: reduced graphene oxide, polyaniline, nanocomposites, supercapacitors, energy storage
Procedia PDF Downloads 59217 Quantitative Polymerase Chain Reaction Analysis of Phytoplankton Composition and Abundance to Assess Eutrophication: A Multi-Year Study in Twelve Large Rivers across the United States
Authors: Chiqian Zhang, Kyle D. McIntosh, Nathan Sienkiewicz, Ian Struewing, Erin A. Stelzer, Jennifer L. Graham, Jingrang Lu
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Phytoplankton plays an essential role in freshwater aquatic ecosystems and is the primary group synthesizing organic carbon and providing food sources or energy to ecosystems. Therefore, the identification and quantification of phytoplankton are important for estimating and assessing ecosystem productivity (carbon fixation), water quality, and eutrophication. Microscopy is the current gold standard for identifying and quantifying phytoplankton composition and abundance. However, microscopic analysis of phytoplankton is time-consuming, has a low sample throughput, and requires deep knowledge and rich experience in microbial morphology to implement. To improve this situation, quantitative polymerase chain reaction (qPCR) was considered for phytoplankton identification and quantification. Using qPCR to assess phytoplankton composition and abundance, however, has not been comprehensively evaluated. This study focused on: 1) conducting a comprehensive performance comparison of qPCR and microscopy techniques in identifying and quantifying phytoplankton and 2) examining the use of qPCR as a tool for assessing eutrophication. Twelve large rivers located throughout the United States were evaluated using data collected from 2017 to 2019 to understand the relation between qPCR-based phytoplankton abundance and eutrophication. This study revealed that temporal variation of phytoplankton abundance in the twelve rivers was limited within years (from late spring to late fall) and among different years (2017, 2018, and 2019). Midcontinent rivers had moderately greater phytoplankton abundance than eastern and western rivers, presumably because midcontinent rivers were more eutrophic. The study also showed that qPCR- and microscope-determined phytoplankton abundance had a significant positive linear correlation (adjusted R² 0.772, p-value < 0.001). In addition, phytoplankton abundance assessed via qPCR showed promise as an indicator of the eutrophication status of those rivers, with oligotrophic rivers having low phytoplankton abundance and eutrophic rivers having (relatively) high phytoplankton abundance. This study demonstrated that qPCR could serve as an alternative tool to traditional microscopy for phytoplankton quantification and eutrophication assessment in freshwater rivers.Keywords: phytoplankton, eutrophication, river, qPCR, microscopy, spatiotemporal variation
Procedia PDF Downloads 101216 Improving Fluid Catalytic Cracking Unit Performance through Low Cost Debottlenecking
Authors: Saidulu Gadari, Manoj Kumar Yadav, V. K. Satheesh, Debasis Bhattacharyya, S. S. V. Ramakumar, Subhajit Sarkar
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Most Fluid Catalytic Cracking Units (FCCUs) are big profit makers and hence, always operated with several constraints. It is the primary source for production of gasoline, light olefins as petrochemical feedstocks, feedstock for alkylate & oxygenates, LPG, etc. in a refinery. Increasing unit capacity and improving product yields as well as qualities such as gasoline RON have dramatic impact on the refinery economics. FCCUs are often debottlenecked significantly beyond their original design capacities. Depending upon the unit configuration, operating conditions, and feedstock quality, the FCC unit can have a variety of bottlenecks. While some of these are aimed to increase the feed rate, improve the conversion, etc., the others are aimed to improve the reliability of the equipment or overall unit. Apart from investment cost, the other factors considered generally while evaluating the debottlenecking options are shutdown days, faster payback, risk on investment, etc. A low-cost solution such as replacement of feed injectors, air distributor, steam distributors, spent catalyst distributor, efficient cyclone system, etc. are the preferred way of upgrading FCCU. It also has lower lead time from idea inception to implementation. This paper discusses various bottlenecks generally encountered in FCCU and presents a case study on improvement of performance of one of the FCCUs in IndianOil through implementation of cost-effective technical solution including use of improved internals in Reactor-Regeneration (R-R) section. After implementation reduction in regenerator air, gas superficial velocity in regenerator and cyclone velocities by about 10% and improvement of CLO yield from 10 to 6 wt% have been achieved. By ensuring proper pressure balance and optimum immersion of cyclone dipleg in the standpipe, frequent formation of perforations in regenerator cyclones could be addressed which in turn improved the unit on-stream factor.Keywords: FCC, low-cost, revamp, debottleneck, internals, distributors, cyclone, dipleg
Procedia PDF Downloads 215215 Production and Purification of Monosaccharides by Hydrolysis of Sugar Cane Bagasse in an Ionic Liquid Medium
Authors: T. R. Bandara, H. Jaelani, G. J. Griffin
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The conversion of lignocellulosic waste materials, such as sugar cane bagasse, to biofuels such as ethanol has attracted significant interest as a potential element for transforming transport fuel supplies to totally renewable sources. However, the refractory nature of the cellulosic structure of lignocellulosic materials has impeded progress on developing an economic process, whereby the cellulose component may be effectively broken down to glucose monosaccharides and then purified to allow downstream fermentation. Ionic liquid (IL) treatment of lignocellulosic biomass has been shown to disrupt the crystalline structure of cellulose thus potentially enabling the cellulose to be more readily hydrolysed to monosaccharides. Furthermore, conventional hydrolysis of lignocellulosic materials yields byproducts that are inhibitors for efficient fermentation of the monosaccharides. However, selective extraction of monosaccharides from an aqueous/IL phase into an organic phase utilizing a combination of boronic acids and quaternary amines has shown promise as a purification process. Hydrolysis of sugar cane bagasse immersed in an aqueous solution with IL (1-ethyl-3-methylimidazolium acetate) was conducted at different pH and temperature below 100 ºC. It was found that the use of a high concentration of hydrochloric acid to acidify the solution inhibited the hydrolysis of bagasse. At high pH (i.e. basic conditions), using sodium hydroxide, catalyst yields were reduced for total reducing sugars (TRS) due to the rapid degradation of the sugars formed. For purification trials, a supported liquid membrane (SLM) apparatus was constructed, whereby a synthetic solution containing xylose and glucose in an aqueous IL phase was transported across a membrane impregnated with phenyl boronic acid/Aliquat 336 to an aqueous phase. The transport rate of xylose was generally higher than that of glucose indicating that a SLM scheme may not only be useful for purifying sugars from undesirable toxic compounds, but also for fractionating sugars to improve fermentation efficiency.Keywords: biomass, bagasse, hydrolysis, monosaccharide, supported liquid membrane, purification
Procedia PDF Downloads 254214 The Analgesic Impact of Adding Intrathecal Ketamine to Spinal Anaesthesia for Hip or Knee Arthroplasty: A Clinical Audit
Authors: Carl Ashworth, Matthys Campher
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Spinal anaesthesia has been identified as the “gold standard” for primary elective total hip and knee arthroplasty, which is most commonly performed using longer-acting local anaesthetics, such as hyperbaric bupivacaine, to prolong the duration of anaesthesia and analgesia suitable for these procedures. Ketamine is known to have local anaesthetic effects with potent analgesic properties and has been evaluated as a sole anaesthetic agent via intrathecal administration; however, the use of intrathecal ketamine as an adjunct to intrathecal hyperbaric bupivacaine, morphine, and fentanyl has not been extensively studied. The objective of this study was to identify the potential analgesic effects of the addition of intrathecal ketamine to spinal anaesthesia and to compare the efficacy and safety of adding intrathecal ketamine to spinal anaesthesia for hip- or knee arthroplasty with spinal anaesthesia for hip- or knee arthroplasty without intrathecal ketamine. The medical records of patients who underwent elective hip- or knee arthroplasty under spinal anaesthesia performed by an individual anaesthetist with either intrathecal hyperbaric bupivacaine, morphine and fentanyl or intrathecal hyperbaric bupivacaine, morphine, fentanyl and ketamine between June 4, 2020, and June 4, 2022, were retrospectively reviewed. These encounters were reviewed and analyzed from a perioperative pain perspective, with the primary outcome measure as the oral morphine equivalent (OME) usage in the 48 hours post-spinal anaesthesia, and secondary outcome measures including time to breakthrough analgesia, self-reported pain scores at rest and during movement at 24 and 48 hours after surgery, adverse effects of analgesia, complications, and length of stay. There were 26 patients identified who underwent TKR between June 4, 2020, and June 4, 2022, and 25 patients who underwent THR with the same conditions. It was identified that patients who underwent traditional spinal anaesthesia with the addition of ketamine for elective hip- or knee arthroplasty had a lower mean total OME in the 48 hours immediately post-spinal anaesthesia yet had a shorter time to breakthrough analgesia administration. The proposed mechanism of action for intrathecal ketamine as an additive to traditional spinal anaesthesia for elective hip- or knee arthroplasty is that it may prolong and attenuate the analgesic effect of traditional spinal anaesthesia. There were no significant differences identified in comparing the efficacy and safety of adding intrathecal ketamine to spinal anaesthesia for hip- or knee arthroplasty with spinal anaesthesia for hip- or knee arthroplasty without intrathecal ketamine.Keywords: anaesthesia, spinal, intra-thecal, ketamine, spinal-morphine, bupivacaine
Procedia PDF Downloads 52213 Ultrastructural Study of Surface Topography of Trematode Parasites of Domestic Buffalo (Bubalus bubalis) in Udaipur, India
Authors: Gayatri Swarnakar
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Paramphistomiasis and fascioliasis diseases have been prevalent due to presence of trematode parasites in the rumen and liver of domestic buffalo (Bubalus bubalis) in Udaipur, India. The trematode parasites such as Paramphistomum cervi, Gastrothylax crumenifer, Cotylophoron cotylophorum, Orthocoelium scoliocoelium, Fasciola hepatica and Fasciola gigantica were collected from infected rumen and liver of the freshly slaughtered buffaloes (Bubalus bubalis) at local zoo abattoir in Udaipur. Live trematodes were washed in normal saline, fixed in 0.2M cacodylate fixative, post fixed in osmium tetraoxide, dehydrated, dried, coated with gold sputter and observed under scanning electronic microscope (SEM). The surface tegument of Paramphistomum cervi was spineless with transverse folds, discontinuous with ridges and grooves. Two types of sensory papillae such as knob like and button shaped were also observed. The oral opening of Cotylophoron cotylophorum was surrounded by wrinkled and ridged tegument which formed concentric elevated rings. Tegument of Cotylophoron cotylophorum in acetabulum region was observed to be rough and bee-comb like structure. Genital sucker of this worm was surrounded by a tyre- shaped elevation of the tegument. Orthocoelium scoliocoelium showed circular and concentric rings of tegumental folds around the oral sucker. Genital pore had knob like papillae with radial tegumental folds. Surface topography of Fasciola gigantica and Fasciola hepatica were found to be rough due to occurrence of different types of spines, three types of sensory papillae, transverse folds and grooves. Oral and ventral suckers were spineless and covered with thick rims of transverse folds. Genital pore showed small scattered spines. Present research work would provide knowledge for ultrastructural characteristics of trematode parasites for chemotherapeutic measures and help us to evolve suitable strategy for the eradication of trematode parasites from the domestic buffalo (Bubalus bubalis).Keywords: Domestic buffalo, tegument, trematode parasites, ultrastructure
Procedia PDF Downloads 308212 Using Rainfall Simulators to Design and Assess the Post-Mining Erosional Stability
Authors: Ashraf M. Khalifa, Hwat Bing So, Greg Maddocks
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Changes to the mining environmental approvals process in Queensland have been rolled out under the MERFP Act (2018). This includes requirements for a Progressive Rehabilitation and Closure Plan (PRC Plan). Key considerations of the landform design report within the PRC Plan must include: (i) identification of materials available for landform rehabilitation, including their ability to achieve the required landform design outcomes, (ii) erosion assessments to determine landform heights, gradients, profiles, and material placement, (iii) slope profile design considering the interactions between soil erodibility, rainfall erosivity, landform height, gradient, and vegetation cover to identify acceptable erosion rates over a long-term average, (iv) an analysis of future stability based on the factors described above e.g., erosion and /or landform evolution modelling. ACARP funded an extensive and thorough erosion assessment program using rainfall simulators from 1998 to 2010. The ACARP program included laboratory assessment of 35 soil and spoil samples from 16 coal mines and samples from a gold mine in Queensland using 3 x 0.8 m laboratory rainfall simulator. The reliability of the laboratory rainfall simulator was verified through field measurements using larger flumes 20 x 5 meters and catchment scale measurements at three sites (3 different catchments, average area of 2.5 ha each). Soil cover systems are a primary component of a constructed mine landform. The primary functions of a soil cover system are to sustain vegetation and limit the infiltration of water and oxygen into underlying reactive mine waste. If the external surface of the landform erodes, the functions of the cover system cannot be maintained, and the cover system will most likely fail. Assessing a constructed landform’s potential ‘long-term’ erosion stability requires defensible erosion rate thresholds below which rehabilitation landform designs are considered acceptably erosion-resistant or ‘stable’. The process used to quantify erosion rates using rainfall simulators (flumes) to measure rill and inter-rill erosion on bulk samples under laboratory conditions or on in-situ material under field conditions will be explained.Keywords: open-cut, mining, erosion, rainfall simulator
Procedia PDF Downloads 101211 Microbial Fuel Cells and Their Applications in Electricity Generating and Wastewater Treatment
Authors: Shima Fasahat
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This research is an experimental research which was done about microbial fuel cells in order to study them for electricity generating and wastewater treatment. These days, it is very important to find new, clean and sustainable ways for energy supplying. Because of this reason there are many researchers around the world who are studying about new and sustainable energies. There are different ways to produce these kind of energies like: solar cells, wind turbines, geothermal energy, fuel cells and many other ways. Fuel cells have different types one of these types is microbial fuel cell. In this research, an MFC was built in order to study how it can be used for electricity generating and wastewater treatment. The microbial fuel cell which was used in this research is a reactor that has two tanks with a catalyst solution. The chemical reaction in microbial fuel cells is a redox reaction. The microbial fuel cell in this research is a two chamber MFC. Anode chamber is an anaerobic one (ABR reactor) and the other chamber is a cathode chamber. Anode chamber consists of stabilized sludge which is the source of microorganisms that do redox reaction. The main microorganisms here are: Propionibacterium and Clostridium. The electrodes of anode chamber are graphite pages. Cathode chamber consists of graphite page electrodes and catalysts like: O2, KMnO4 and C6N6FeK4. The membrane which separates the chambers is Nafion117. The reason of choosing this membrane is explained in the complete paper. The main goal of this research is to generate electricity and treating wastewater. It was found that when you use electron receptor compounds like: O2, MnO4, C6N6FeK4 the velocity of electron receiving speeds up and in a less time more current will be achieved. It was found that the best compounds for this purpose are compounds which have iron in their chemical formula. It is also important to pay attention to the amount of nutrients which enters to bacteria chamber. By adding extra nutrients in some cases the result will be reverse. By using ABR the amount of chemical oxidation demand reduces per day till it arrives to a stable amount.Keywords: anaerobic baffled reactor, bioenergy, electrode, energy efficient, microbial fuel cell, renewable chemicals, sustainable
Procedia PDF Downloads 227210 Shoulder Range of Motion Measurements using Computer Vision Compared to Hand-Held Goniometric Measurements
Authors: Lakshmi Sujeesh, Aaron Ramzeen, Ricky Ziming Guo, Abhishek Agrawal
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Introduction: Range of motion (ROM) is often measured by physiotherapists using hand-held goniometer as part of mobility assessment for diagnosis. Due to the nature of hand-held goniometer measurement procedure, readings often tend to have some variations depending on the physical therapist taking the measurements (Riddle et al.). This study aims to validate computer vision software readings against goniometric measurements for quick and consistent ROM measurements to be taken by clinicians. The use of this computer vision software hopes to improve the future of musculoskeletal space with more efficient diagnosis from recording of patient’s ROM with minimal human error across different physical therapists. Methods: Using the hand-held long arm goniometer measurements as the “gold-standard”, healthy study participants (n = 20) were made to perform 4 exercises: Front elevation, Abduction, Internal Rotation, and External Rotation, using both arms. Assessment of active ROM using computer vision software at different angles set by goniometer for each exercise was done. Interclass Correlation Coefficient (ICC) using 2-way random effects model, Box-Whisker plots, and Root Mean Square error (RMSE) were used to find the degree of correlation and absolute error measured between set and recorded angles across the repeated trials by the same rater. Results: ICC (2,1) values for all 4 exercises are above 0.9, indicating excellent reliability. Lowest overall RMSE was for external rotation (5.67°) and highest for front elevation (8.00°). Box-whisker plots showed have showed that there is a potential zero error in the measurements done by the computer vision software for abduction, where absolute error for measurements taken at 0 degree are shifted away from the ideal 0 line, with its lowest recorded error being 8°. Conclusion: Our results indicate that the use of computer vision software is valid and reliable to use in clinical settings by physiotherapists for measuring shoulder ROM. Overall, computer vision helps improve accessibility to quality care provided for individual patients, with the ability to assess ROM for their condition at home throughout a full cycle of musculoskeletal care (American Academy of Orthopaedic Surgeons) without the need for a trained therapist.Keywords: physiotherapy, frozen shoulder, joint range of motion, computer vision
Procedia PDF Downloads 107209 Rethinking Classical Concerts in the Digital Era: Transforming Sound, Experience, and Engagement for the New Generation
Authors: Orit Wolf
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Classical music confronts a crucial challenge: updating cherished concert traditions for the digital age. This paper is a journey, and a quest to make classical concerts resonate with a new generation. It's not just about asking questions; it's about exploring the future of classical concerts and their potential to captivate and connect with today's audience in an era defined by change. The younger generation, known for their love of diversity, interactive experiences, and multi-sensory immersion, cannot be overlooked. This paper explores innovative strategies that forge deep connections with audiences whose relationship with classical music differs from the past. The urgency of this challenge drives the transformation of classical concerts. Examining classical concerts is necessary to understand how they can harmonize with contemporary sensibilities. New dimensions in audiovisual experiences that enchant the emerging generation are sought. Classical music must embrace the technological era while staying open to fusion and cross-cultural collaboration possibilities. The role of technology and Artificial Intelligence (AI) in reshaping classical concerts is under research. The fusion of classical music with digital experiences and dynamic interdisciplinary collaborations breathes new life into the concert experience. It aligns classical music with the expectations of modern audiences, making it more relevant and engaging. Exploration extends to the structure of classical concerts. Conventions are challenged, and ways to make classical concerts more accessible and captivating are sought. Inspired by innovative artistic collaborations, musical genres and styles are redefined, transforming the relationship between performers and the audience. This paper, therefore, aims to be a catalyst for dialogue and a beacon of innovation. A set of critical inquiries integral to reshaping classical concerts for the digital age is presented. As the world embraces digital transformation, classical music seeks resonance with contemporary audiences, redefining the concert experience while remaining true to its roots and embracing revolutions in the digital age.Keywords: new concert formats, reception of classical music, interdiscplinary concerts, innovation in the new musical era, mash-up, cross culture, innovative concerts, engaging musical performances
Procedia PDF Downloads 64208 Mechanical and Tribological Performances of (Nb: H-D: a-C) Thin Films for Biomedical Applications
Authors: Sara Khamseh, Kambiz Javanruee, Hamid Khorsand
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Plenty of metallic materials are used for biomedical applications like hip joints and screws. Besides, it is reported that metal platforms such as stainless steel show significant deterioration because of wear and friction. The surface of metal substrates has been coated with a variety of multicomponent coatings to prevail these problems. The carbon-based multicomponent coatings such as metal-added amorphous carbon and diamond coatings are crucially important because of their remarkable tribological performance and chemical stability. In the current study, H-D contained Nb: (a-C) multicomponent coatings (H-D: hexagonal diamond, a-C: amorphous carbon) coated on A 304 steel substrates using an unbalanced magnetron (UBM) sputtering system. The effects of Nb and H-D content and ID/IG ratio on microstructure, mechanical and tribological characteristics of (Nb: H-D: a-C) composite coatings were investigated. The results of Raman spectroscopy represented that a-C phase with a Graphite-like structure (GLC with high value of sp2 carbon bonding) is formed, and its domain size increased with increasing Nb content of the coatings. Moreover, the Nb played a catalyst for the formation of the H-D phase. The nanoindentation hardness value of the coatings ranged between ~17 to ~35 GPa and (Nb: H-D: a-C) composite coatings with more H-D content represented higher hardness and plasticity index. It seems that the existence of extra-hard H-D particles straightly increased hardness. The tribological performance of the coatings was evaluated using the pin-on-disc method under the wet environment of SBF (Simulated Body Fluid). The COF value of the (Nb: H-D: a-C) coatings decreased with an increasing ID/IG ratio. The lower coefficient of friction is a result of the lamelliform array of graphitic domains. Also, the wear rate of the coatings decreased with increasing H-D content of the coatings. Based on the literature, a-C coatings with high hardness and H3/E2 ratio represent lower wear rates and better tribological performance. According to the nanoindentation analysis, hardness and H3/E2 ratio of (Nb: H-D: a-C) multicomponent coatings increased with increasing H-D content, which in turn decreased the wear rate of the coatings. The mechanical and tribological potency of (Nb: H-D: a-C) composite coatings on A 304 steel substrates paved the way for the development of innovative advanced coatings to ameliorate the performance of A 304 steel for biomedical applications.Keywords: COF, mechanical properties, (Nb: H-D: a-C) coatings, wear rate
Procedia PDF Downloads 103207 Analyzing the Contamination of Some Food Crops Due to Mineral Deposits in Ondo State, Nigeria
Authors: Alexander Chinyere Nwankpa, Nneka Ngozi Nwankpa
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In Nigeria, the Federal government is trying to make sure that everyone has access to enough food that is nutritiously adequate and safe. But in the southwest of Nigeria, notably in Ondo State, the most valuable minerals such as oil and gas, bitumen, kaolin, limestone talc, columbite, tin, gold, coal, and phosphate are abundant. Therefore, some regions of Ondo State are now linked to large quantities of natural radioactivity as a result of the mineral presence. In this work, the baseline radioactivity levels in some of the most important food crops in Ondo State were analyzed, allowing for the prediction of probable radiological health impacts. To this effect, maize (Zea mays), yam (Dioscorea alata) and cassava (Manihot esculenta) tubers were collected from the farmlands in the State because they make up the majority of food's nutritional needs. Ondo State was divided into eight zones in order to provide comprehensive coverage of the research region. At room temperature, the maize (Zea mays), yam (Dioscorea alata), and cassava (Manihot esculenta) samples were dried until they reached a consistent weight. They were pulverized, homogenized, and 250 g packed in a 1-liter Marinelli beaker and kept for 28 days to achieve secular equilibrium. The activity concentrations of Radium-226 (Ra-226), Thorium-232 (Th-232), and Potassium-40 (K-40) were determined in the food samples using Gamma-ray spectrometry. Firstly, the Hyper Pure Germanium detector was calibrated using standard radioactive sources. The gamma counting, which lasted for 36000s for each sample, was carried out in the Centre for Energy Research and Development, Obafemi Awolowo University, Ile-Ife, Nigeria. The mean activity concentration of Ra-226, Th-232 and K-40 for yam were 1.91 ± 0.10 Bq/kg, 2.34 ± 0.21 Bq/kg and 48.84 ± 3.14 Bq/kg, respectively. The content of the radionuclides in maize gave a mean value of 2.83 ± 0.21 Bq/kg for Ra-226, 2.19 ± 0.07 Bq/kg for Th-232 and 41.11 ± 2.16 Bq/kg for K-40. The mean activity concentrations in cassava were 2.52 ± 0.31 Bq/kg for Ra-226, 1.94 ± 0.21 Bq/kg for Th-232 and 45.12 ± 3.31 Bq/kg for K-40. The average committed effective doses in zones 6-8 were 0.55 µSv/y for the consumption of yam, 0.39 µSv/y for maize, and 0.49 µSv/y for cassava. These values are higher than the annual dose guideline of 0.35 µSv/y for the general public. Therefore, the values obtained in this work show that there is radiological contamination of some foodstuffs consumed in some parts of Ondo State. However, we recommend that systematic and appropriate methods also need to be established for the measurement of gamma-emitting radionuclides since these constitute important contributors to the internal exposure of man through ingestion, inhalation, or wound on the body.Keywords: contamination, environment, radioactivity, radionuclides
Procedia PDF Downloads 104206 Rapid Fetal MRI Using SSFSE, FIESTA and FSPGR Techniques
Authors: Chen-Chang Lee, Po-Chou Chen, Jo-Chi Jao, Chun-Chung Lui, Leung-Chit Tsang, Lain-Chyr Hwang
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Fetal Magnetic Resonance Imaging (MRI) is a challenge task because the fetal movements could cause motion artifact in MR images. The remedy to overcome this problem is to use fast scanning pulse sequences. The Single-Shot Fast Spin-Echo (SSFSE) T2-weighted imaging technique is routinely performed and often used as a gold standard in clinical examinations. Fast spoiled gradient-echo (FSPGR) T1-Weighted Imaging (T1WI) is often used to identify fat, calcification and hemorrhage. Fast Imaging Employing Steady-State Acquisition (FIESTA) is commonly used to identify fetal structures as well as the heart and vessels. The contrast of FIESTA image is related to T1/T2 and is different from that of SSFSE. The advantages and disadvantages of these two scanning sequences for fetal imaging have not been clearly demonstrated yet. This study aimed to compare these three rapid MRI techniques (SSFSE, FIESTA, and FSPGR) for fetal MRI examinations. The image qualities and influencing factors among these three techniques were explored. A 1.5T GE Discovery 450 clinical MR scanner with an eight-channel high-resolution abdominal coil was used in this study. Twenty-five pregnant women were recruited to enroll fetal MRI examination with SSFSE, FIESTA and FSPGR scanning. Multi-oriented and multi-slice images were acquired. Afterwards, MR images were interpreted and scored by two senior radiologists. The results showed that both SSFSE and T2W-FIESTA can provide good image quality among these three rapid imaging techniques. Vessel signals on FIESTA images are higher than those on SSFSE images. The Specific Absorption Rate (SAR) of FIESTA is lower than that of the others two techniques, but it is prone to cause banding artifacts. FSPGR-T1WI renders lower Signal-to-Noise Ratio (SNR) because it severely suffers from the impact of maternal and fetal movements. The scan times for these three scanning sequences were 25 sec (T2W-SSFSE), 20 sec (FIESTA) and 18 sec (FSPGR). In conclusion, all these three rapid MR scanning sequences can produce high contrast and high spatial resolution images. The scan time can be shortened by incorporating parallel imaging techniques so that the motion artifacts caused by fetal movements can be reduced. Having good understanding of the characteristics of these three rapid MRI techniques is helpful for technologists to obtain reproducible fetal anatomy images with high quality for prenatal diagnosis.Keywords: fetal MRI, FIESTA, FSPGR, motion artifact, SSFSE
Procedia PDF Downloads 530205 Effects of Application of Rice Husk Charcoal-Coated Urea and Rice Straw Compost on Growth, Yield, and Soil Properties of Rice
Authors: D. A. S. Gamage, B. F. A Basnayake, W. A. J. M. de Costa
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Rice is one of the world’s most important cereals. Increasing food production both to meet in-country requirements and to help overcome food crises is one of the major issues facing Sri Lanka today. However, productive land is limited and has mostly been utilized either for food crop production or other uses. Agriculture plays an important and strategic role in the performance of Sri Lankan national economy. A variety of modern agricultural inputs have been introduced, namely ploughs and harvesters, pesticides, fertilizers and lime. Besides, there are several agricultural institutions developing and updating the management of agricultural sector. Modern agricultural inputs cooperate as a catalyst in raising the productivity. However, in the eagerness of gaining profits from the efficient and productive techniques, this modern agricultural input has affected the environment and living things especially those which have been blended from various chemical substance. The increased pressure to maintain a high level of rice output for consumption has resulted in increased use of pesticides and inorganic fertilizer on rice fields in Sri Lanka. The application of inorganic fertilizer has become a burdened to the country in many ways. The excessive reuse of the ground water resources with a considerable application of organic and chemical fertilizers will lead to a deterioration of the quality and quantity of water. Biochar is a form of charcoal produced through the heating of natural organic materials. It has received significant attention recently for its potential as a soil conditioner, a fertilizer and as a means of storing carbon in a sustainable manner. It is the best solution for managing the agricultural wastes while providing a useful product for increasing agricultural productivity and protecting the environment. The objective of this study was to evaluate rice husk charcoal coated urea as a slow releasing fertilizer and compare the total N, P, K, organic matter in soil and yield of rice production.Keywords: biochar, paddy husk, soil conditioner, rice straw compost
Procedia PDF Downloads 351204 One-Step Synthesis and Characterization of Biodegradable ‘Click-Able’ Polyester Polymer for Biomedical Applications
Authors: Wadha Alqahtani
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In recent times, polymers have seen a great surge in interest in the field of medicine, particularly chemotherapeutics. One recent innovation is the conversion of polymeric materials into “polymeric nanoparticles”. These nanoparticles can be designed and modified to encapsulate and transport drugs selectively to cancer cells, minimizing collateral damage to surrounding healthy tissues, and improve patient quality of life. In this study, we have synthesized pseudo-branched polyester polymers from bio-based small molecules, including sorbitol, glutaric acid and a propargylic acid derivative to further modify the polymer to make it “click-able" with an azide-modified target ligand. Melt polymerization technique was used for this polymerization reaction, using lipase enzyme catalyst NOVO 435. This reaction was conducted between 90- 95 °C for 72 hours. The polymer samples were collected in 24-hour increments for characterization and to monitor reaction progress. The resulting polymer was purified with the help of methanol dissolving and filtering with filter paper then characterized via NMR, GPC, FTIR, DSC, TGA and MALDI-TOF. Following characterization, these polymers were converted to a polymeric nanoparticle drug delivery system using solvent diffusion method, wherein DiI optical dye and chemotherapeutic drug Taxol can be encapsulated simultaneously. The efficacy of the nanoparticle’s apoptotic effects were analyzed in-vitro by incubation with prostate cancer (LNCaP) and healthy (CHO) cells. MTT assays and fluorescence microscopy were used to assess the cellular uptake and viability of the cells after 24 hours at 37 °C and 5% CO2 atmosphere. Results of the assays and fluorescence imaging confirmed that the nanoparticles were successful in both selectively targeting and inducing apoptosis in 80% of the LNCaP cells within 24 hours without affecting the viability of the CHO cells. These results show the potential of using biodegradable polymers as a vehicle for receptor-specific drug delivery and a potential alternative for traditional systemic chemotherapy. Detailed experimental results will be discussed in the e-poster.Keywords: chemotherapeutic drug, click chemistry, nanoparticle, prostat cancer
Procedia PDF Downloads 115203 Petrology and Petrochemistry of Basement Rocks in Ila Orangun Area, Southwestern Nigeria
Authors: Jayeola A. O., Ayodele O. S., Olususi J. I.
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From field studies, six (6) lithological units were identified to be common around the study area, which includes quartzites, granites, granite gneiss, porphyritic granites, amphibolite and pegmatites. Petrographical analysis was done to establish the major mineral assemblages and accessory minerals present in selected rock samples, which represents the major rock types in the area. For the purpose of this study, twenty (20) pulverized rock samples were taken to the laboratory for geochemical analysis with their results used in the classification, as well as suggest the geochemical attributes of the rocks. Results from petrographical studies of the rocks under both plane and cross polarized lights revealed the major minerals identified under thin sections to include quartz, feldspar, biotite, hornblende, plagioclase and muscovite with opaque other accessory minerals, which include actinolite, spinel and myrmekite. Geochemical results obtained and interpreted using various geochemical plots or discrimination plots all classified the rocks in the area as belonging to both the peralkaline metaluminous and peraluminous types. Results for the major oxides ratios produced for Na₂O/K₂O, Al₂O₃/Na₂O + CaO + K₂O and Na₂O + CaO + K₂O/Al₂O₃ show the excess of alumina, Al₂O₃ over the alkaline Na₂O +CaO +K₂O thus suggesting peraluminous rocks. While the excess of the alkali over the alumina suggests the peralkaline metaluminous rock type. The results of correlation coefficient show a perfect strong positive correlation, which shows that they are of same geogenic sources, while negative correlation coefficient values indicate a perfect weak negative correlation, suggesting that they are of heterogeneous geogenic sources. From factor analysis, five component groups were identified as Group 1 consists of Ag-Cr-Ni elemental associations suggesting Ag, Cr, and Ni mineralization, predicting the possibility of sulphide mineralization. in the study area. Group ll and lll consist of As-Ni-Hg-Fe-Sn-Co-Pb-Hg element association, which are pathfinder elements to the mineralization of gold. Group 1V and V consist of Cd-Cu-Ag-Co-Zn, which concentrations are significant to elemental associations and mineralization. In conclusion, from the potassium radiometric anomaly map produced, the eastern section (northeastern and southeastern) is observed to be the hot spot and mineralization zone for the study area.Keywords: petrography, Ila Orangun, petrochemistry, pegmatites, peraluminous
Procedia PDF Downloads 61202 Surgical Hip Dislocation of Femoroacetabular Impingement: Survivorship and Functional Outcomes at 10 Years
Authors: L. Hoade, O. O. Onafowokan, K. Anderson, G. E. Bartlett, E. D. Fern, M. R. Norton, R. G. Middleton
Abstract:
Aims: Femoroacetabular impingement (FAI) was first recognised as a potential driver for hip pain at the turn of the last millennium. While there is an increasing trend towards surgical management of FAI by arthroscopic means, open surgical hip dislocation and debridement (SHD) remains the Gold Standard of care in terms of reported outcome measures. (1) Long-term functional and survivorship outcomes of SHD as a treatment for FAI are yet to be sufficiently reported in the literature. This study sets out to help address this imbalance. Methods: We undertook a retrospective review of our institutional database for all patients who underwent SHD for FAI between January 2003 and December 2008. A total of 223 patients (241 hips) were identified and underwent a ten year review with a standardised radiograph and patient-reported outcome measures questionnaire. The primary outcome measure of interest was survivorship, defined as progression to total hip arthroplasty (THA). Negative predictive factors were analysed. Secondary outcome measures of interest were survivorship to further (non-arthroplasty) surgery, functional outcomes as reflected by patient reported outcome measure scores (PROMS) scores, and whether a learning curve could be identified. Results: The final cohort consisted of 131 females and 110 males, with a mean age of 34 years. There was an overall native hip joint survival rate of 85.4% at ten years. Those who underwent a THA were significantly older at initial surgery, had radiographic evidence of preoperative osteoarthritis and pre- and post-operative acetabular undercoverage. In those whom had not progressed to THA, the average Non-arthritic Hip Score and Oxford Hip Score at ten year follow-up were 72.3% and 36/48, respectively, and 84% still deemed their surgery worthwhile. A learning curve was found to exist that was predicated on case selection rather than surgical technique. Conclusion: This is only the second study to evaluate the long-term outcomes (beyond ten years) of SHD for FAI and the first outside the originating centre. Our results suggest that, with correct patient selection, this remains an operation with worthwhile outcomes at ten years. How the results of open surgery compared to those of arthroscopy remains to be answered. While these results precede the advent of collison software modelling tools, this data helps set a benchmark for future comparison of other techniques effectiveness at the ten year mark.Keywords: femoroacetabular impingement, hip pain, surgical hip dislocation, hip debridement
Procedia PDF Downloads 84