Search results for: electrochemical reduction

Authors: Chen Zhang, Nan Chen

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High-dimensional process monitoring becomes increasingly important in many application domains, where usually the process distribution is unknown and much more complicated than the normal distribution, and the between-stream correlation can not be neglected. However, since the process dimension is generally much bigger than the reference sample size, most traditional nonparametric multivariate control charts fail in high-dimensional cases due to the curse of dimensionality. Furthermore, when the process goes out of control, the influenced variables are quite sparse compared with the whole dimension, which increases the detection difficulty. Targeting at these issues, this paper proposes a new nonparametric monitoring scheme for high-dimensional processes. This scheme first projects the high-dimensional process into several subprocesses using random projections for dimension reduction. Then, for every subprocess with the dimension much smaller than the reference sample size, a local nonparametric control chart is constructed based on the spatial rank test to detect changes in this subprocess. Finally, the results of all the local charts are fused together for decision. Furthermore, after an out-of-control (OC) alarm is triggered, a diagnostic framework is proposed. using the square-root LASSO. Numerical studies demonstrate that the chart has satisfactory detection power for sparse OC changes and robust performance for non-normally distributed data, The diagnostic framework is also effective to identify truly changed variables. Finally, a real-data example is presented to demonstrate the application of the proposed method.

Keywords: random projection, high-dimensional process control, spatial rank, sequential change detection

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Authors: Chevon Fernando, Banuka Athuraliya

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The purpose of this research is to provide a solution to the students’ time management, which usually becomes an issue because students must study and manage their personal commitments. "TimeTune," an AI-based study planner that provides an opportunity to maneuver study timeframes by incorporating modern machine learning algorithms with calendar applications, is unveiled as the ideal solution. The research is focused on the development of LSTM models that connect to the Google Calendar API in the process of developing learning paths that would be fit for a unique student's daily life experience and study history. A key finding of this research is the success in building the LSTM model to predict optimal study times, which, integrating with the real-time data of Google Calendar, will generate the timetables automatically in a personalized and customized manner. The methodology encompasses Agile development practices and Object-Oriented Analysis and Design (OOAD) principles, focusing on user-centric design and iterative development. By adopting this method, students can significantly reduce the tension associated with poor study habits and time management. In conclusion, "TimeTune" displays an advanced step in personalized education technology. The fact that its application of ML algorithms and calendar integration is quite innovative is slowly and steadily revolutionizing the lives of students. The excellence of maintaining a balanced academic and personal life is stress reduction, which the applications promise to provide for students when it comes to managing their studies.

Keywords: personalized learning, study planner, time management, calendar integration

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Authors: Walaa G. Hozayen, Osama M. Ahmed, Haidy T. Abo Sree

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The clinical usefulness of anthracycline antineoplastic antibiotic, doxorubicin (DOX) is restricted since it has several acute and chronic side effects. The effect of doxorubicin (4 mg/kg b.w/week) without or with oral administration of purslane (Portulaca oleracea) shoot ethanolic extract (50mg/kg b.w./day) and purslane seed ethanolic extract (50mg/kg b.w./day) co-treatments for 6 weeks was evaluated in adult male rats. Serum testosterone luteinizing hormone (LH), follicle stimulating hormone (FSH) level were assayed. Testis lipid peroxidation (indexed by MDA) and antioxidants like glutathione (GSH), glutathione-S-transferase (GST), peroxidase (POX), superoxide dismutase (SOD), catalase (CAT) levels in testis were assessed. The data revealed a significant decrease in serum levels concentration of testosterone, LH and FSH levels in doxorubicin-injected rats. In addition, testis glutathione, glutathione transferase, peroxidase, SOD and CAT levels were decreased while lipid peroxidation concentration in the testis was increased as a result of doxorubicin injection. Co-administration of ethanolic purslane and seed extracts potentially improved the adverse changes in serum testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH) levels with an increase in testis antioxidants levels and reduction in lipid peroxidation. In conclusion, it can be suggested that dietary purslane extract supplementation may provide a cushion for a prolonged therapeutic option against DOX testicular toxicity without harmful side effects.

Keywords: doxorubicin, purslane, testis function, antioxidants

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Authors: Haleh Dadgostar, Faramarz Akbari, Hosien Vahid Tari, Masoud Solaymani-Dodaran, Mohammad Razi

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Introduction: There are a number of exercises-protocols have been applied to improve low back pain. We compared the effect of supervised exercise therapy and home-based exercise therapy among patients with nonspecific chronic low back pain. Methods: 70 patients with nonspecific chronic low back pain were randomly (using a random number generator, excel) divided into two groups to compare the effects of two types of exercise therapy. After a common educational session to learn how to live with low back pain as well as to use core training protocols to strengthen the muscles, the subjects were randomly assigned to follow supervised exercise therapy (n = 31) or home-based exercise therapy (n = 34) for 20 weeks. Results: Although both types of exercise programs resulted in reduced pain, this factor decreased more significantly in supervised exercise program. All scores of fitness improved significantly in supervised exercise group. But only knee extensor strength score was increased in the home base exercise group. Conclusion: Comparing between two types of exercise, supervised group exercise showed more effective than the other one. Reduction in low back pain severity and improvement in muscle flexibility and strength can be more achieved by using a 20-week supervised exercise program compared to the home-based exercise program in patients with nonspecific chronic low back pain.

Keywords: low back pain, anthropometric parameters, supervised exercise therapy, home-based exercise therapy

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Authors: Shuangxin Wu

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Superalloy ultra-thin-walled components occupy a considerable proportion of aero engines and play an increasingly important role in structural weight reduction and performance improvement. To solve problems such as high deformation resistance and poor formability at room temperature, the introduction of pulse current in the processing process can improve the plasticity of metal materials, but the influence mechanism of pulse current on the forming limit of superalloy ultra-thin sheet is not clear, which is of great significance for determining the material processing window and improving the micro-forming process. The effect of pulse current on the microstructure evolution of superalloy thin plates was observed by optical microscopy (OM) and X-ray diffraction topography (XRT) by applying pulse current to GH3039 with a thickness of 0.2mm under plane strain and uniaxial tensile states. Compared with the specimen without pulse current applied at the same temperature, the internal void volume fraction is significantly reduced, reflecting the non-thermal effect of pulse current on the growth of micro-pores. ED (electrically deforming) specimens have larger and deeper dimples, but the elongation is not significantly improved because the pulse current promotes the void coalescence process, resulting in material fracture. The electro-plastic phenomenon is more obvious in the plane strain state, which is closely related to the effect of stress triaxial degree on the void evolution under pulsed current.

Keywords: pulse current, superalloy, ductile fracture, void damage

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Authors: Shiji Hu, Lei Li, Wanting Zhou, DaoHong Yang

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The data encryption, is the foundation of today’s communication. On this basis, how to improve the speed of data encryption and decryption is always a problem that scholars work for. In this paper, we proposed an elliptic curve crypto processor architecture based on SM2 prime field. In terms of hardware implementation, we optimized the algorithms in different stages of the structure. In finite field modulo operation, we proposed an optimized improvement of Karatsuba-Ofman multiplication algorithm, and shorten the critical path through pipeline structure in the algorithm implementation. Based on SM2 recommended prime field, a fast modular reduction algorithm is used to reduce 512-bit wide data obtained from the multiplication unit. The radix-4 extended Euclidean algorithm was used to realize the conversion between affine coordinate system and Jacobi projective coordinate system. In the parallel scheduling of point operations on elliptic curves, we proposed a three-level parallel structure of point addition and point double based on the Jacobian projective coordinate system. Combined with the scalar multiplication algorithm, we added mutual pre-operation to the point addition and double point operation to improve the efficiency of the scalar point multiplication. The proposed ECC hardware architecture was verified and implemented on Xilinx Virtex-7 and ZYNQ-7 platforms, and each 256-bit scalar multiplication operation took 0.275ms. The performance for handling scalar multiplication is 32 times that of CPU(dual-core ARM Cortex-A9).

Keywords: Elliptic curve cryptosystems, SM2, modular multiplication, point multiplication.

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Authors: Serpa A. M., Gómez Hoyos C., Velásquez-Cock J. A., Ruiz L. F., Vélez Acosta L. M., Gañan P., Zuluaga R.

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Turmeric (Curcuma Longa L) is an Indian rhizome known for its biological properties, derived from its active compounds such as curcuminoids. Curcumin, the main polyphenol in turmeric, only represents around 3.5% of the dehydrated rhizome and extraction yields between 41 and 90% have been reported. Therefore, for every 1000 tons of turmeric powder used for the extraction of curcumin, around 970 tons of residues are generated. The present study evaluates the effect of different mechanical treatments (waring blender, grinder and high-pressure homogenization) on the physical and chemical properties of turmeric, as an alternative for the transformation of the entire rhizome. Suspensions of turmeric (10, 20 y 30%) were processed by waring blender during 3 min at 12000 rpm, while the samples treated by grinder were processed evaluating two different Gaps (-1 and -1,5). Finally, the process by high-pressure homogenization, was carried out at 500 bar. According to the results, the luminosity of the samples increases with the severity of the mechanical treatment, due to the stabilization of the color associated with the inactivation of the oxidative enzymes. Additionally, according to the microstructure of the samples, the process by grinder (Gap -1,5) and by high-pressure homogenization allowed the largest size reduction, reaching sizes up to 3 m (measured by optical microscopy). This processes disrupts the cells and breaks their fragments into small suspended particles. The infrared spectra obtained from the samples using an attenuated total reflectance accessory indicates changes in the 800-1200 cm⁻¹ region, related mainly to changes in the starch structure. Finally, the thermogravimetric analysis shows the presence of starch, curcumin and some minerals in the suspensions.

Keywords: characterization, mechanical treatments, suspensions, turmeric rhizome

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Authors: Sandrine Andriantsimietry, Hantanirina Ravaosendrasoa

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Madagascar, in 2018, set up the first best available technology, autoclave, to treat the health care waste in public hospitals according the best environmental practices in health care waste management. Incineration of health care waste, frequently through open burning is the most common practice of treatment and elimination of health care waste across the country. Autoclave is a best available technology for non-incineration of health care waste that permits recycling of treated waste and prevents harm in environment through the reduction of unintended persistent organic pollutants from the health sector. A Global Environment Fund project supported the introduction of the non-incineration treatment of health care waste to help countries in Africa to move towards Stockholm Convention objectives in the health sector. Two teaching hospitals in Antananarivo and one district hospital in Manjakandriana were equipped respectively with 1300L, 250L and 80L autoclaves. The capacity of these model hospitals was strengthened by the donation of equipment and materials and the training of the health workers in best environmental practices in health care waste management. Proper segregation of waste in the wards to collect the infectious waste that was treated in the autoclave was the main step guaranteeing a cost-efficient non-incineration of health care waste. Therefore, the start-up of the switch of incineration into non-incineration treatment was carried out progressively in each ward with close supervision of hygienist. Emissions avoided of unintended persistent organic pollutants during these four months of autoclaves use is 9.4 g Toxic Equivalent per year. Public hospitals in low income countries can be model in best environmental practices in health care waste management but efforts must be made internally for sustainment.

Keywords: autoclave, health care waste management, model hospitals, non-incineration

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Authors: Virgo Sulakatko

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The reduction of energy consumption of the built environment has been one of the topics tackled by European Commission during the last decade. Increased energy efficiency requirements have increased the renovation rate of apartment buildings covered with External Thermal Insulation Composite System (ETICS). Due to fast and optimized application process, a large extent of quality assurance is depending on the specific activities of artisans and are often not controlled. The on-site degradation factors (DF) have the technical influence to the façade and cause future costs to the owner. Besides the thermal conductivity, the building envelope needs to ensure the mechanical resistance and stability, fire-, noise-, corrosion and weather protection, and long-term durability. As the shortcomings of the construction phase become problematic after some years, the common value of the renovation is reduced. Previous work on the subject has identified and rated the relevance of DF to the technical requirements and developed a method to reveal the economic value of repair works. The future costs can be traded off to increased the quality assurance during the construction process. The proposed framework is describing the joint simulation of the technical importance and economic value of the on-site DFs of ETICS. The model is providing new knowledge to improve the resource allocation during the construction process by enabling to identify and diminish the most relevant degradation factors and increase economic value to the owner.

Keywords: ETICS, construction technology, construction management, life cycle costing

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Authors: Nataly De La Pava, Christian S. A. Silva-Torres, Arodí P. Favaris, José Maurício S. Bento

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The lady beetles Tenuisvalve notata and Cryptolaemus montrouzieri are important predators of mealybugs (Hemiptera: Pseudococcidae). Similar to the prey, these lady beetles produce wax filaments that cover their body during the larval stage. It has been hypothesized that lady beetle body wax chemical profiles are similar to their prey as i) a mechanism of camouflage and ii) conveying protection to the lady beetle larvae against aphid-tending predatory ants. In this study, we tested those hypotheses for the predators T. notata and C. montrouzieri and two mealybug prey species, Ferissia dasyrilii, and Planococcus citri. Next, we evaluated the influence of feeding on cuticular chemistry during predator development and identified possible metabolic costs associated with wax production. Cuticular wax samples were analyzed by GC-MS and GC-FID. Also, the metabolic cost linked to wax production was evaluated in the 4th instar larvae of the two predators when subjected to body wax removal from 0 to 4 times. Results showed that predator body wax profiles are not similar to the chemical profile of prey body wax. There was a metabolic cost associated with wax removal; predators (male and female) showed a significant reduction in adult body weight when the wax was removed. This suggests the reallocation of energy to wax replacement instead of growth. In addition, it was detected effects of wax removal on fecundity and egg viability. The results do not support the hypothesis that predators mimic the cuticular wax composition of prey as a means of camouflage.

Keywords: biological control, body wax, coccinellids, cuticular hydrocarbons, metabolism cost, reproduction

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Authors: Lavanya Ratnabala, Robinroy Peter, E. Y. A. Charles

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This research paper addresses the challenges of exploration and navigation in unknown environments from an evolutionary swarm robotics perspective. Path formation plays a crucial role in enabling cooperative swarm robots to accomplish these tasks. The paper presents a method called the sub-goal-based path formation, which establishes a path between two different locations by exploiting visually connected sub-goals. Simulation experiments conducted in the Argos simulator demonstrate the successful formation of paths in the majority of trials. Furthermore, the paper tackles the problem of inter-collision (traffic) among a large number of robots engaged in path formation, which negatively impacts the performance of the sub-goal-based method. To mitigate this issue, a task allocation strategy is proposed, leveraging local communication protocols and light signal-based communication. The strategy evaluates the distance between points and determines the required number of robots for the path formation task, reducing unwanted exploration and traffic congestion. The performance of the sub-goal-based path formation and task allocation strategy is evaluated by comparing path length, time, and resource reduction against the A* algorithm. The simulation experiments demonstrate promising results, showcasing the scalability, robustness, and fault tolerance characteristics of the proposed approach.

Keywords: swarm, path formation, task allocation, Argos, exploration, navigation, sub-goal

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Authors: Xiang Jia, Zhijun Cheng

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The residual lifetime of a product is the operation time between the current time and the time point when the failure happens. The residual lifetime estimation is rather important in reliability analysis. To predict the residual lifetime, it is necessary to assume or verify a particular distribution that the lifetime of the product follows. And the two-parameter Weibull distribution is frequently adopted to describe the lifetime in reliability engineering. Due to the time constraint and cost reduction, a life testing experiment is usually terminated before all the units have failed. Then the censored data is usually collected. In addition, other information could also be obtained for reliability analysis. The expert judgements are considered as it is common that the experts could present some useful information concerning the reliability. Therefore, the residual lifetime is estimated for Weibull distribution by fusing the censored data and expert judgements in this paper. First, the closed-forms concerning the point estimate and confidence interval for the residual lifetime under the Weibull distribution are both presented. Next, the expert judgements are regarded as the prior information and how to determine the prior distribution of Weibull parameters is developed. For completeness, the cases that there is only one, and there are more than two expert judgements are both focused on. Further, the posterior distribution of Weibull parameters is derived. Considering that it is difficult to derive the posterior distribution of residual lifetime, a sample-based method is proposed to generate the posterior samples of Weibull parameters based on the Monte Carlo Markov Chain (MCMC) method. And these samples are used to obtain the Bayes estimation and credible interval for the residual lifetime. Finally, an illustrative example is discussed to show the application. It demonstrates that the proposed method is rather simple, satisfactory, and robust.

Keywords: expert judgements, information fusion, residual lifetime, Weibull distribution

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Authors: S. Gharbi, S. Labidi, M. Mars, M. Chelli, F. Ladeb

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The purpose of this study is to reduce radiation dose for chest CT examination by including Tube Current Modulation (TCM) to a standard CT protocol. A scan of an anthropomorphic male Alderson phantom was performed on a 128-slice scanner. The estimation of effective dose (ED) in both scans with and without mAs modulation was done via multiplication of Dose Length Product (DLP) to a conversion factor. Results were compared to those measured with a CT-Expo software. The size specific dose estimation (SSDE) values were obtained by multiplication of the volume CT dose index (CTDIvol) with a conversion size factor related to the phantom’s effective diameter. Objective assessment of image quality was performed with Signal to Noise Ratio (SNR) measurements in phantom. SPSS software was used for data analysis. Results showed including CARE Dose 4D; ED was lowered by 48.35% and 51.51% using DLP and CT-expo, respectively. In addition, ED ranges between 7.01 mSv and 6.6 mSv in case of standard protocol, while it ranges between 3.62 mSv and 3.2 mSv with TCM. Similar results are found for SSDE; dose was higher without TCM of 16.25 mGy and was lower by 48.8% including TCM. The SNR values calculated were significantly different (p=0.03<0.05). The highest one is measured on images acquired with TCM and reconstructed with Filtered back projection (FBP). In conclusion, this study proves the potential of TCM technique in SSDE and ED reduction and in conserving image quality with high diagnostic reference level for thoracic CT examinations.

Keywords: anthropomorphic phantom, computed tomography, CT-expo, radiation dose

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Authors: Emmanuel Dada, Adebayo-Victoria Tobi Dada

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The study evaluates land use and land cover changes in the cocoa belt of Ondo state to quantify its effect on the expanse of land occupied by cocoa plantation as the most suitable region for cocoa raisin in Nigeria. Time series of satellite imagery from Landsat-7 ETM+ and Landsat-8 TIRS covering years 2000 and 2015 respectively were used. The study area was classified into six land use themes of cocoa plantation, settlement, water body, light forest and grassland, forest, and bar surface and rock outcrop. The analyses revealed that out of total land area of 997714 hectares of land of the study area, cocoa plantation land use increased by 10.3% in 2015 from 312260.6 ha in 2000. Forest land use also increased by 6.3% in 2015 from 152144.1 ha in the year 2000, water body reduced from 2954.5 ha in the year 2000 by 0.1% in 2015, settlement land use increased by 3% in 2015 from 15194.6 ha in 2000, light forest and grassland area reduced by 10.4% between 2000 and 2015 and 9.1% reduction in bar surface and rock outcrop land use between the year 2000 and 2015 respectively. The reasons for different ranges in the changes observed in the land use and land cover in the study area could be due to increase in the incentive to cocoa farmers from both government and non-governmental organizations, developed new cocoa breed that thrive better in the light forest, rapid increased in the population of cocoa farmers’ settlements, and government promulgation of forest reserve law.

Keywords: satellite imagery, land use and land cover change, area of land

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Authors: Gaurav Kumar Sinha

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The oil refining industry, significant in its energy consumption and carbon emissions, faces increasing pressure to reduce its environmental footprint. This article explores the application of energy efficiency and sustainability analytics as crucial tools for reducing carbon emissions in oil refineries. Through a comprehensive review of current practices and technologies, this study highlights innovative analytical approaches that can significantly enhance energy efficiency. We focus on the integration of advanced data analytics, including machine learning and predictive modeling, to optimize process controls and energy use. These technologies are examined for their potential to not only lower energy consumption but also reduce greenhouse gas emissions. Additionally, the article discusses the implementation of sustainability analytics to monitor and improve environmental performance across various operational facets of oil refineries. We explore case studies where predictive analytics have successfully identified opportunities for reducing energy use and emissions, providing a template for industry-wide application. The challenges associated with deploying these analytics, such as data integration and the need for skilled personnel, are also addressed. The paper concludes with strategic recommendations for oil refineries aiming to enhance their sustainability practices through the adoption of targeted analytics. By implementing these measures, refineries can achieve significant reductions in carbon emissions, aligning with global environmental goals and regulatory requirements.

Keywords: energy efficiency, sustainability analytics, carbon emissions, oil refineries, data analytics, machine learning, predictive modeling, process optimization, greenhouse gas reduction, environmental performance

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Authors: Abimbola Olaotan Akinsete

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Government all over the world has intensified efforts in making internet and resource centres readily available in public institutions and centres for the advancement of humanity and working processes. Information and communication resource centre will not only help in the reduction of task that are presumed to be herculean. This centres influenced the working rate and productivity of both staffs and students and its benefit. The utilization of the internet and information resource centre will not only speed up service delivery, working time and efficiency of the system. Information and Communication Technology plays significant roles in presenting equalization strategy for developing university community and improving educational service delivery. This equalization will not only advance, accelerate and ensure results are accessed electronically, ensuring the transfer and confirmation of students’ academic records and their results in the world without physically available to request for these services. This study seeks to make Critical Appraisal of Adekunle Ajasin University Policy on Internet Resource Centre in Service Delivery Adekunle Ajasin University, Akungba-Akoko, Ondo State. The study employ descriptive survey design method in identifying hindrances of the non-utilization of technology in the service delivery in the university. Findings revealed that the adoption of internet and resource centre in the Exams and Records unit of the University shall help in delivering more in students’ records/results processing.

Keywords: internet, resource, centre, policy and service delivery

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Authors: Soomal Hamza, Uzma Imran

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Organochlorine pesticides bio-accumulate into the fat of fish, birds, and animals through which it enters the human food cycle. Due to their persistence and stability in the environment, many health impacts are associated with them, most of which are carcinogenic in nature. In this study, the level of organochlorine pesticides has been detected in Keenjhar Lake and remediated using Rhizoremediation technique. 14 OC pesticides namely, Aldrin, Deldrin, Heptachlor, Heptachlor epoxide, Endrin, Endosulfun I and II, DDT, DDE, DDD, Alpha, Beta, Gamma BHC and two plants namely, Water Hyacinth and Slvinia Molesta were used in the system using pot experiment which processed for 11 days. A consortium was inoculated in both plants to increase its efficiency. Water samples were processed using liquide-liquid extraction. Sediments and roots samples were processed using Soxhlet method followed by clean-up and Gas Chromatography. Delta-BHC was the predominantly found in all samples with mean concentration (ppb) and standard deviation of 0.02 ± 0.14, 0.52 ± 0.68, 0.61 ± 0.06, in Water, Sediments and Roots samples respectively. The highest levels were of Endosulfan II in the samples of water, sediments and roots. Water Hyacinth proved to be better bioaccumulaor as compared to Silvinia Molesta. The pattern of compounds reduction rate by the end of experiment was Delta-BHC>DDD > Alpha-BHC > DDT> Heptachlor> H.Epoxide> Deldrin> Aldrin> Endrin> DDE> Endosulfun I > Endosulfun II. Not much significant difference was observed between the pots with the consortium and pots without the consortium addition. Phytoremediation is a promising technique, but more studies are required to assess the bioremediation potential of different aquatic plants and plant-endophyte relationship.

Keywords: aquatic plant, bio remediation, gas chromatography, liquid liquid extraction

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Authors: S. Shanthi

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Catalyzed oxidation processes show extraordinary guarantee for application in numerous wastewater treatment ranges. Advanced oxidation processes are emerging innovation that might be utilized for particular objectives in wastewater treatment. This research work provides a solution for removal a refractory organic compound 2,4-dichlorophenoxyaceticacid a common water pollutant. All studies were done in batch mode in a constantly stirred reactor. Alternative ozonation processes catalysed by transition metals or granular activated carbon have been investigated for degradation of organics. Catalytic ozonation under study are homogeneous catalytic ozonation, which is based on ozone activation by transition metal ions present in aqueous solution, and secondly as heterogeneous catalytic ozonation in the presence of Granular Activated Carbon (GAC). The present studies reveal that heterogeneous catalytic ozonation using GAC favour the ozonation of 2,4-dichlorophenoxyaceticacid by increasing the rate of ozonation and a much higher degradation of substrates were obtained in a given time. Be that it may, Fe2+and Fe3+ ions decreased the rate of degradation of 2,4-dichlorophenoxyaceticacid indicating that it acts as a negative catalyst. In case of heterogeneous catalytic ozonation using GAC catalyst it was found that during the initial 5 minutes of contact solution concentration decreased significantly as the pollutants were adsorbed initially. Thereafter the substrate started getting oxidized and ozonation became a dominates the treatment process. The exhausted GAC was found to be regenerated in situ. The percentage reduction of the substrate was maximum achieved in minimum possible time when GAC catalyst is employed.

Keywords: ozonation, homogeneous catalysis, heterogeneous catalysis, granular activated carbon

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Authors: Sterling C. DeVerter

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In recent decades, there has been continually growing concern amongst scholars and political leaders towards the global resurgence of nationalism, particularly in Europe, the United States, and China. However, very few studies have attempted to empirically examine the relationship between religion and nationalism at the level of the individual, and none are known to have done so quantitatively. Building on Tajfel's and Turner's (1978) Social Identity Theory (SIT), and Anderson (1991) and Marx (2003), this study will employ SIT and regression analysis to compare the sources and patterns of nationalistic sentiment among European respondents in eight countries to the average levels of self-reported religiosity, religious participation, age, education, and income levels. Survey reports from the International Social Survey Programme were the primary quantitative data sources. It was hypothesized that the increase in nationalism across Europe follows this same evolution as first identified by Anderson, and is positively correlated to the reduction in reported religiosity. However, this study failed to reject the null, there was no substantial ( < .035) correlation between nationalistic sentiment and any of the measures of religiosity, nor were there any substantial correlations between nationalistic sentiment and either of the three control variables ( < .008). Across all countries examined, it was discovered that inclusionary nationalism has slightly declined (-5.08%), while exclusionary nationalism had increased substantially (+17.25%). The combined trend reflected an overall rise in nationalism across the time period and a forecast that suggests the current levels are also elevated. The primary implications include the demand to readdress the notion of religion and nationalism, and the correlation between the two, as well as the current nationalism trends in terms of support or non-support for future political and social movements.

Keywords: European Union, secularization, nationalism, social identity theory

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Authors: Ling Ai, Ziyu Zhao, Zeyu Zhou, Xiaochen Yang, Heng Zhai, Stuart Holmes

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Optimizing the catalyst layer structure is crucial for enhancing the performance of proton exchange membrane fuel cells (PEMFCs) with low Platinum (Pt) loading. Current works focused on the utilization, durability, and site activity of Pt particles on support, and performance enhancement has been achieved by loading Pt onto porous support with different morphology, such as graphene, carbon fiber, and carbon black. Some schemes have also incorporated cost considerations to achieve lower Pt loading. However, the design of the catalyst layer (CL) structure in the membrane electrode assembly (MEA) must consider the interactions between the layers. Addressing the crucial aspects of water management, low contact resistance, and the establishment of effective three-phase boundary for MEA, multi-walled carbon nanotubes (MWCNTs) are promising CL support due to their intrinsically high hydrophobicity, high axial electrical conductivity, and potential for ordered alignment. However, the drawbacks of MWCNTs, such as strong agglomeration, wall surface chemical inertness, and unopened ends, are unfavorable for Pt nanoparticle loading, which is detrimental to MEA processing and leads to inhomogeneous CL surfaces. This further deteriorates the utilization of Pt and increases the contact resistance. Robust chemical oxidation or nitrogen doping can introduce polar functional groups onto the surface of MWCNTs, facilitating the creation of open tube ends and inducing defects in tube walls. This improves dispersibility and load capacity but reduces length and conductivity. Consequently, a trade-off exists between maintaining the intrinsic properties and the degree of functionalization of MWCNTs. In this work, MWCNTs were modified based on the operational requirements of the MEA from the viewpoint of interlayer interactions, including the search for the optimal degree of oxidation, N-doping, and micro-arrangement. MWCNT were functionalized by oxidizing, N-doping, as well as micro-alignment to achieve lower contact resistance between CL and proton exchange membrane (PEM), better hydrophobicity, and enhanced performance. Furthermore, this work expects to construct a more continuously distributed three-phase boundary by aligning MWCNT to form a locally ordered structure, which is essential for the efficient utilization of Pt active sites. Different from other chemical oxidation schemes that used HNO3:H2SO4 (1:3) mixed acid to strongly oxidize MWCNT, this scheme adopted pure HNO3 to partially oxidize MWCNT at a lower reflux temperature (80 ℃) and a shorter treatment time (0 to 10 h) to preserve the morphology and intrinsic conductivity of MWCNT. The maximum power density of 979.81 mw cm-2 was achieved by Pt loading on 6h MWCNT oxidation time (Pt-MWCNT6h). This represented a 59.53% improvement over the commercial Pt/C catalyst of 614.17 (mw cm-2). In addition, due to the stronger electrical conductivity, the charge transfer resistance of Pt-MWCNT6h in the electrochemical impedance spectroscopy (EIS) test was 0.09 Ohm cm-2, which was 48.86% lower than that of Pt/C. This study will discuss the developed catalysts and their efficacy in a working fuel cell system. This research will validate the impact of low-functionalization modification of MWCNTs on the performance of PEMFC, which simplifies the preparation challenges of CL and contributing for the widespread commercial application of PEMFCs on a larger scale.

Keywords: carbon nanotubes, electrocatalyst, membrane electrode assembly, proton exchange membrane fuel cell

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Authors: Lusine Tadevosyan, Natella Mirzoyan, Anna Yeritsyan, Narek Avetisyan

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Due to high quality, the artesian groundwater is the main source of water supply for the fisheries in Ararat Valley, Armenia. From 1.6 billion m3 abstracted groundwater in 2016, half was used by fish farms. Yet, the inefficient water use, typical for low-intensity aquaculture systems in Ararat Valley, has become a key environmental issue in Armenia. In addition to excessive pure groundwater exploitation, which along with other sectors of groundwater use in this area resulted in the reduction of artesian zone by approximately 67% during last 20 years, the negative environmental impact of these productions is magnified by the discharge of large volumes of wastewater into receiving water bodies. In turn, unsustainable use of artesian groundwater in Ararat Valley along with increasingly strict policy measures on water use had a devastating impact on small and/or medium scale aquaculture: over the last two years approximately 100 fish farms have permanently seized their operations. The current project aims at the introduction of efficient and environmentally friendly fish farming practices (e.g., Recirculating Aquaculture Systems) in Ararat Valley fisheries in order to support current levels of fish production and simultaneously reduce the negative environmental pressure of aquaculture facilities in Armenia. Economic and environmental analysis of current small and medium scale operational systems and subsequently developed environmentally–friendly and economically sustainable system configurations will be presented.

Keywords: aquaculture, groundwater, recirculation, sustainability

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Authors: P. Dey, S. K. Pal

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Ceramics or glass ceramics with the property of bone bonding at the nearby tissues and producing possible bone in growth are known to be bioactive. The most extensively used glass in this context is 45S5 which is a silica based bioglass mostly explored in the field of tissue engineering as scaffolds for bone repair. Nowadays, the borate based bioglass are being utilized in orthopedic area largely due to its superior bioactivity with the formation of bone bonding. An attempt has been made, in the present study, to observe the effect of B2O3 addition in 45S5 glass and perceive its consequences on the thermal, mechanical and biological properties. The B2O3 was added in 1, 2.5, and 5 wt% with simultaneous reduction in the silica content of the 45S5 composition. The borate based bioglass has been synthesized by the means of sol-gel route. The synthesized powders were then thermally analyzed by DSC-TG. The as synthesized powders were then calcined at 600ºC for 2hrs. The calcined powders were then pressed into pellets followed by sintering at 850ºC with a holding time of 2hrs. The phase analysis and the microstructural analysis of the as synthesized and calcined powder glass samples and the sintered glass samples were being carried out using XRD and FESEM respectively. The formation of hydroxyapatite layer was performed by immersing the sintered samples in the simulated body fluid (SBF) and mechanical property has been tested for the sintered samples by universal testing machine (UTM). The sintered samples showed the presence of sodium calcium silicate phase while the formation of hydroxyapaptite takes place for SBF immersed samples. The formation of hydroxyapatite is more pronounced in case of borated based glass samples instead of 45S5.

Keywords: 45S5 bioglass, bioactive, borate, hydroxyapatite, sol-gel synthesis

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Authors: Laura Dembovska, Diana Bajare, Ina Pundiene, Daira Erdmane

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The aim of this research is to estimate effect of pozzolanic substitutes and their combination on the hydration heat and final strength of high performance concrete. Ternary cementitious systems with different ratios of ordinary Portland cement, silica fume and calcined clay were investigated. Local illite clay was calcined at temperature 700oC in rotary furnace for 20 min. It has been well recognized that the use of pozzolanic materials such as silica fume or calcined clay are recommended for high performance concrete for reduction of porosity, increasing density and as a consequence raising the chemical durability of the concrete. It has been found, that silica fume has a superior influence on the strength development of concrete, but calcined clay increase density and decrease size of dominating pores. Additionally it was found that the rates of pozzolanic reaction and calcium hydroxide consumption in the silica fume-blended cement pastes are higher than in the illite clay-blended cement pastes, it strongly depends from the amount of pozzolanic substitutes which are used. If the pozzolanic reaction is dominating then amount of Ca(OH)2 is decreasing. The identity and the amount of the phases present were determined from the thermal analysis (DTA) data. The hydration temperature of blended cement pastes was measured during the first 24 hours. Fresh and hardened concrete properties were tested. Compressive strength was determined and differential thermal analysis (DTA) was conducted of specimens at the age of 3, 14, 28 and 56 days.

Keywords: high performance concrete, pozzolanic additives, silica fume, ternary systems

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Authors: Carla Idely Palencia-Aguilar

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Mining in Colombia represents around 2% of the GDP (USD 8 billion in 2018), with main productions represented by coal, nickel, gold, silver, emeralds, iron, limestone, gypsum, among others. Sand and Gravel had been decreasing its participation of the GDP with a reduction of 33.2 million m3 in 2015, to 27.4 in 2016, 22.7 in 2017 and 15.8 in 2018, with a consumption of approximately 3 tons/inhabitant. However, with the new government policies it is expected to increase in the following years. Mining causes temporary environmental impacts, once restoration and rehabilitation takes place, social, environmental and economic benefits are higher than the initial state. A way to demonstrate how the mining interventions had contributed to improve the characteristics of the region after sand and gravel mining, the NDVI (Normalized Difference Vegetation Index) from MODIS and ASTER were employed. The histograms show not only increments of vegetation in the area (8 times higher), but also topographies similar to the ones before the intervention, according to the application for sustainable development selected: either agriculture, forestry, cattle raising, artificial wetlands or do nothing. The decision was based upon a Multicriteria analysis for optimal land use, with three main variables: geostatistics, evapotranspiration and groundwater characteristics. The use of remote sensing, meteorological stations, piezometers, sunphotometers, geoelectric analysis among others; provide the information required for the multicriteria decision. For cattle raising and agricultural applications (where various crops were implemented), conservation of products were tested by means of nanotechnology. The results showed a duration of 2 years with no chemicals added for preservation and concentration of vitamins of the tested products.

Keywords: ASTER, Geostatistics, MODIS, Multicriteria

Procedia PDF Downloads 126

Authors: Mohamed A. Hammad, Dzul Azri Mohamed Noor, Syed Azhar Syed Sulaiman, Majed Ahmed Al-Mansoub, Muhammad Qamar

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There is a progressive increase in the prevalence of early onset Type 2 diabetes mellitus. Early detection of Type 2 diabetes enhances the length and/or quality of life which might result from a reduction in the severity, frequency or prevent or delay of its long-term complications. The study aims to determine the onset age for the first diagnosis of Type 2 diabetes mellitus. A retrospective study conducted in the endocrine clinic at Hospital Pulau Pinang in Penang, Malaysia, January- December 2016. Records of 519 patients with Type 2 diabetes mellitus were screened to collect demographic data and determine the age of first-time diabetes mellitus diagnosis. Patients classified according to the age of diagnosis, gender, and ethnicity. The study included 519 patients with age (55.6±13.7) years, female 265 (51.1%) and male 254 (48.9%). The ethnicity distribution was Malay 191 (36.8%), Chinese 189 (36.4%) and Indian 139 (26.8%). The age of Type 2 diabetes diagnosis was (42±14.8) years. The female onset of diabetes mellitus was at age (41.5±13.7) years, while male (42.6±13.7) years. Distribution of diabetic onset by ethnicity was Malay at age (40.7±13.7) years, Chinese (43.2±13.7) years and Indian (42.3±13.7) years. Diabetic onset was classified by age as follow; ≤20 years’ cohort was 33 (6.4%) cases. Group >20- ≤40 years was 190 (36.6%) patients, and category >40- ≤60 years was 270 (52%) subjects. On the other hand, the group >60 years was 22 (4.2%) patients. The range of diagnosis was between 10 and 73 years old. Conclusion: Malay and female have an earlier onset of diabetes than Indian, Chinese and male. More than half of the patients had diabetes between 40 and 60 years old. Diabetes mellitus is becoming more common in younger age <40 years. The age at diagnosis of Type 2 diabetes mellitus has decreased with time.

Keywords: age of onset, diabetes diagnosis, diabetes mellitus, Malaysia, outpatients, type 2 diabetes, retrospective study

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Authors: Yohtahe Woldegerima Berhe, Tadesse Belayneh Melkie, Girmay Fitiwi Lema, Marye Getnet, Wubie Birlie Chekol

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Introduction: Anxiety was repeatedly reported as the worst aspect of the perioperative time. The objective of this study was to assess the prevalence of preoperative anxiety among adult surgical patients at the University of Gondar Comprehensive Specialized Hospital (UoGCSH), Northwest Ethiopia. Methodology: Hospital-based cross-sectional study was conducted among surgical patients at the university hospital. After obtaining ethical approval, 407 surgical patients were approached during the preoperative period. Preoperative anxiety was assessed by the State-Trait Anxiety Inventory. The association between variables was determined by using binary logistic regression analysis. The strength of association was described in adjusted odds ratio (AOR) and a p-value < 0.05 at a 95% confidence interval which was considered statistically significant. Results: A total of 400 patients were included in this study, with a 98.3% response rate. Preoperative anxiety was observed among 237 (59.3%) patients, and the median (IQR) STAI score was 50 (40 – 56.7). age ≥ 60 years (AOR: 5.7, CI: 1.6 – 20.4, P: 0.007), emergency surgery (AOR: 2.5, CI: 1.3 – 4.7, P: 0.005), preoperative pain (AOR: 2.6, CI: 1.2 – 5.4, P: 0.005), and rural residency (AOR: 1.8, CI: 1.1 – 2.9, P: 0.031) were found significantly associated with preoperative anxiety. Conclusions: The prevalence of preoperative anxiety among surgical patients was high. Older age (≥ 60 years), emergency surgery, preoperative pain, and rural residency were found to be significantly associated with preoperative anxiety. Assessment for preoperative anxiety should be a routine component of preoperative assessment of both elective and emergency surgical patients. Preoperative pain should be appropriately managed as it can help to reduce preoperative anxiety. Optimal anxiety reduction methods should be investigated and implemented in the hospital.

Keywords: preoperative anxiety, anxiety, anxiety of anesthesia and surgery, state-trait anxiety inventory, preoperative care

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Authors: Kolja Them, Johannes Salamon, Harald Ittrich, Michael Kaul, Tobias Knopp

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Superparamagnetic iron oxide nanoparticles (SPIONs) are nanoscale magnets which can be biologically functionalized for biomedical applications. Stem cell therapies to repair damaged tissue, magnetic fluid hyperthermia for cancer therapy and targeted drug delivery based on SPIONs are prominent examples where the visualization of a preferably low concentrated SPION distribution is essential. In 2005 a new method for tomographic SPION imaging has been introduced. The method named magnetic particle imaging (MPI) takes advantage of the nanoparticles magnetization change caused by an oscillating, external magnetic field and allows to directly image the time-dependent nanoparticle distribution. The SPION magnetization can be changed by the electron spin dynamics as well as by a mechanical rotation of the nanoparticle. In this work different calibration methods in MPI are investigated for image reconstruction of magnetically labeled stem cells. It is shown that a calibration using rotationally immobilized SPIONs provides a higher quality of stem cell images with fewer artifacts than a calibration using mobile SPIONs. The enhancement of the image quality and the reduction of artifacts enables the localization and identification of a smaller number of magnetically labeled stem cells. This is important for future medical applications where low concentrations of functionalized SPIONs interacting with biological matter have to be localized.

Keywords: biomedical imaging, iron oxide nanoparticles, magnetic particle imaging, stem cell imaging

Procedia PDF Downloads 465

Authors: A. Alhusban, M. Alqawasmeh, F. Alfawares

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Introduction: Despite improvements in stroke management, it remains the leading cause of disability worldwide. It has been suggested that enhancing brain angiogenesis after stroke will improve stroke outcome. Promoting post stroke angiogenesis requires the upregulation of angiogenic factors with a simultaneous reduction of anti-angiogenic factors. Thrombospondin-1 is the main anti-angiogenic protein in the living cells. Counterintuitively, it has been shown that animals with Thrombospondin-1 knockdown will have better stroke outcome. Data about the clinical significance of Thrombspondin-1 levels at the time of admission is still lacking. The objective of this work is to assess the association between serum Thrombospondin-1 levels measured at the time of admission and baseline neurologic severity after stroke. Patients and Methods: Blood samples were collected from patients admitted to the King Abdullah University Hospital (KAUH) with ischemic stroke at the time of admission and serum Thrombopsondin-1 levels were measured using ELISA. Patients neurologic severity was evaluated using the National Institute of Health Stroke Scale (NIHSS). Results: Samples from 50 patients admitted between January 2016 and December 2016 were collected. The median age of participants was 68 years and the median NIHSS was 3. Multinomial regression identified serum Thrombospondin-1 as an independent predictor of stroke outcome (p=0.003). Baseline serum Thrombsopondin-1 was negatively associated with NIHSS at the time of admission (spearman rho correlation coefficient=0.272, p=0.032). Conclusion: Serum Thrombospondin-1 at the time of admission may be a useful marker of stroke severity that predicts more severe neurologic severity.

Keywords: thrombospondin, stroke, neuroprotection, biomarkers

Procedia PDF Downloads 137

Authors: A. Jéglot, F. Plauborg, M. K. Schnorr, R. S. Sørensen, L. Elsgaard

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Artificial wetlands such as woodchip bioreactors are efficient tools to remove nitrate from agricultural wastewater with a minimized environmental impact. However, the temperature dependence of the microbiological nitrate removal prevents the woodchip bioreactors from being an efficient system when the water temperature drops below 8℃. To quantify and describe the temperature effects on nitrate removal efficiency, we studied nitrate-reducing enrichments from a woodchip bioreactor in Denmark based on samples collected in Spring and Fall. Growth was quantified as optical density, and nitrate and nitrous oxide concentrations were measured in time-course experiments to compare the growth of the microbial population and the nitrate conversion efficiencies at different temperatures. Ammonia was measured to indicate the importance of dissimilatory nitrate reduction to ammonia (DNRA) in nitrate conversion for the given denitrifying community. The temperature responses observed followed the increasing trend proposed by the Arrhenius equation, indicating higher nitrate removal efficiencies at higher temperatures. However, the growth and the nitrous oxide production observed at low temperature provided evidence of the psychrotolerance of the microbial community under study. The assays conducted showed higher nitrate removal from the microbial community extracted from the woodchip bioreactor at the cold season compared to the ones extracted during the warmer season. This indicated the ability of the bacterial populations in the bioreactor to evolve and adapt to different seasonal temperatures.

Keywords: agricultural waste water treatment, artificial wetland, denitrification, psychrophilic conditions

Procedia PDF Downloads 122

Authors: Kohtaroh Miyamoto

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As enterprise computing becomes more and more complex, the costs and technical challenges of IT system maintenance and support are increasing rapidly. One popular approach to managing IT system maintenance is to prepare and use an FAQ (Frequently Asked Questions) system to manage and reuse systems knowledge. Such an FAQ system can help reduce the resolution time for each service incident ticket. However, there is a major problem where over time the knowledge in such FAQs tends to become outdated. Much of the knowledge captured in the FAQ requires periodic updates in response to new insights or new trends in the problems addressed in order to maintain its usefulness for problem resolution. These updates require a systematic approach to define the exact portion of the FAQ and its content. Therefore, we are working on a novel method to hierarchically structure the FAQ and automate the updates of its structure and content. We use structured information and the unstructured text information with the timelines of the information in the service incident tickets. We cluster the tickets by structured category information, by keywords, and by keyword modifiers for the unstructured text information. We also calculate an urgency score based on trends, resolution times, and priorities. We carefully studied the tickets of one of our projects over a 2.5-year time period. After the first 6 months, we started to create FAQs and confirmed they improved the resolution times. We continued observing over the next 2 years to assess the ongoing effectiveness of our method for the automatic FAQ updates. We improved the ratio of tickets covered by the FAQ from 32.3% to 68.9% during this time. Also, the average time reduction of ticket resolution was between 31.6% and 43.9%. Subjective analysis showed more than 75% reported that the FAQ system was useful in reducing ticket resolution times.

Keywords: FAQ system, resolution time, service incident tickets, IT system maintenance

Procedia PDF Downloads 338