Search results for: transition metal dichalcogenides

Authors: Shuo Tian, Xuepiao Bai, Jianqin Shang, Pengtao Gai, Yuansong Zeng

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Shot peen forming is an essential forming process for aircraft metal wing panel. With the development of computer simulation technology, scholars have proposed a numerical simulation method of shot peen forming based on stress field. Three shot peen forming indexes of crater diameter, shot speed and surface coverage are required as simulation parameters in the stress field method. It is necessary to establish the relationship between simulation and experimental process parameters in order to simulate the deformation under different shot peen forming parameters. The shot peen forming tests of the 2024-T351 aluminum alloy workpieces were carried out using uniform test design method, and three factors of air pressure, feed rate and shot flow were selected. The second-order response surface model between simulation parameters and uniform test factors was established by stepwise regression method using MATLAB software according to the results. The response surface model was combined with the stress field method to simulate the shot peen forming deformation of the workpiece. Compared with the experimental results, the simulated values were smaller than the corresponding test values, the maximum and average errors were 14.8% and 9%, respectively.

Keywords: shot peen forming, process parameter, response surface model, numerical simulation

Procedia PDF Downloads 83

Authors: Li-Xin Shi, Meng-Fei Hu, Song-Chuan Zhao

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Dense particle suspensions composed of mixtures of particles and fluid are omnipresent in natural phenomena and in industrial processes. Dense particle suspension under shear may lose its uniform state to large local density and stress fluctuations which challenge the mean-field description of the suspension system. However, it still remains largely debated and far from fully understood of the internal mechanism. Here, a dynamics of a non-Brownian suspension is explored under horizontal swirling excitations, where high-density patches appear when the excitation frequency is increased beyond a threshold. These density patches are self-assembled into a hexagonal pattern across the system with further increases in frequency. This phenomenon is underlined by the spontaneous growth of density waves (instabilities) along the flow direction, and the motion of these density waves preserves the circular path and the frequency of the oscillation. To investigate the origin of the phenomena, the constitutive relationship calibrated by independent rheological measurements is implemented into a simplified two-phase flow model. And the critical instability frequency in theory calculation matches the experimental measurements quantitatively without free parameters. By further analyzing the model, the instability is found to be closely related to the discontinuous shear thickening transition of the suspension. In addition, the long-standing density waves degenerate into random fluctuations when replacing the free surface with rigid confinement. It indicates that the shear-thickened state is intrinsically heterogeneous, and the boundary conditions are crucial for the development of local disturbance.

Keywords: dense suspension, instability, self-organization, density wave

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Authors: Abigail Parra Parra, Jorge L. Morelos Hernandez, Pedro A. Marquez Agilar, Marina Vlasova, Jesus Colin De La Cruz

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Carbothermal reduction of metal oxides is widely used both in metallurgical processes and in the production of oxygen-free refractory ceramics. As a rule, crushed coke and graphite are used as a reducing agent. The products of carbonization of organic compounds are among the innovative reducing agents. The aim of this work was to study the process of reduction of iron oxide (hematite) down to iron by waste active sludge (WAS) carbonization products. WAS was chosen due to the accumulation of a large amount of this type of waste, soil pollution, and the relevance of the development of technologies for its disposal. The studies have shown that the temperature treatment of mixtures WAS-Fe₂O₃ in the temperature range 900-1000 ºC for 1-5 hours under oxygen deficiency is described by the following scheme: WAS + Fe₂O₃→ C,CO + Fe₂O₃→ C + FexO → Fe (amorphous and crystalline). During the heat treatment of the mixtures, strong samples are formed. The study of the electrical conductive properties of such samples showed that, depending on the ratio of the components in the initial mixtures, it is possible to change the values of electrical resistivity from 5.6 Ω‧m to 151.6 Ω‧m When a current is passed through the samples, they are heated from 240 to 378ºC. Thus, based on WAS-Fe₂O₃ mixtures, heating elements can be created that can be used to heat ceramics and concrete.

Keywords: Fe₂O₃, reduction, waste activate sludge, electroconductivity

Procedia PDF Downloads 132

Authors: M. J. Suriani, F. Mansor, W. Siti Maizurah, I. Nurizwani

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Silicon Carbide (SiC) is one of the Silicon-based materials, which get interested by the researcher. SiC is an emerging semiconductor material, which has received a great deal of attention due to their application in high frequency and high power systems. Although its superior characteristic for a semiconductor material, its outstanding mechanical properties, chemical inertness and thermal stability has gained important aspect for a surface coating for deployment in extreme environments. Very high frequency (VHF)-PECVD technique utilized to deposit nano ns-SiC film in which variation in chamber pressure, substrate temperature, RF power and precursor gases flow rate will be investigated in order to get a good quality of thin film coating. Characterization of the coating performed in order to study the surface morphology, structural information. This performance of coating evaluated through corrosion test to determine the effectiveness of the coating for corrosion prevention. Ns-SiC film expected to possess better corrosion resistance and optical properties, as well as preserving the metal from the marine environment. Through this research project, corrosion protection performance by applying coating will be explored to obtain a great corrosion prevention method to the shipping and oil and gas industry in Malaysia. Besides, the cost of repair and maintenance spending by the government of Malaysia can be reduced through practicing this method.

Keywords: composite materials, marine corrosion, nano-composite, nano structure–coating

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Authors: Kunthida Kulprateepunya, Napat Boontiam, Bunthita Phuasa, Chatsuda Kankayant, Bantoeng Polsawat, Sumran Poontong

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Frailty is the thin line between good health and illness. The syndrome is more common in the elderly who transition from strong to weak. (Vulnerability). Fragility can prevent and promote healthy recovery before it goes into disability. This research and development aim to analyze the situation analysis of frailty of the elderly, develop a program, and evaluate the effect of a health promotion program to prevent and solve the problem of frailty among the elderly. The research consisted of 3 phases: 1) analysis of the frailty situation, 2) development of a model, 3) evaluation of the effectiveness of the model. Samples were 328, 122 elderlies using the multi-stage random sampling method. The research instrument was a frailty questionnaire use of the five symptoms, the main characteristics were muscle weakness, slow walking, low physical activity. Fatigue and unintentional weight loss, criteria frailty use more than or equal to three or more symptoms are frailty. Data were analyzed by descriptive and t-test dependent test statistics. The findings showed three parts. First, frailty in the elderly was 23.05 percentage and 56.70% pre-frailty. Second, it was development of a health promotion program to prevent and solve the problem of frailty the elderly with a combination of Nine-Square Exercise, Elastic Band Exercise, Elastic Coconut Shell. Third, evaluation of the effectiveness of the model by comparison of the elderly's get up and go test, the average time before using the program was 14.42 and after using the program was 8.57. It was statistically significant at the .05 level. In conclusion, the findings can used to develop guidelines to promote the health of the frailty elderly.

Keywords: elderly, fragile, nine-square exercise, elastic coconut shell

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Authors: Moulay Driss Mellaoui, Abdallah Imjjad, Rachid Boutiddar, Haydar Mohammad-Salim, Nivedita Acharjee, Hassan Bourzi, Souad El Issami, Khalid Abbiche, Hanane Zejli

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We have investigated the underlying molecular processes involved in the [3+2] cycloaddition (32CA) reactions between N-methyl-C-(2-furyl) nitrone and three acetylene derivatives: 4b, 5b, and 6b. For this investigation, we utilized molecular electron density theory (MEDT) and density functional theory (DFT) methods at the B3LYP-D3/6 31G (d) computational level. These 32CA reactions, which exhibit a zwitterionic (zw-type) nature, proceed through a one-step mechanism with activation enthalpies ranging from 8.80 to 14.37 kcal mol−1 in acetonitrile and ethanol solvents. When the nitrone reacts with phenyl methyl propiolate (4b), two regioisomeric pathways lead to the formation of two products: P1,5-4b and P1,4-4b. On the other hand, when the nitrone reacts with dimethyl acetylene dicarboxylate (5b) and acetylene dicarboxylic acid (but-2-ynedioic acid) (6b), it results in the formation of a single product. Through topological analysis, we can categorize the nitrone as a zwitterionic three-atom component (TAC). Furthermore, the analysis of conceptual density functional theory (CDFT) indices classifies the 32CA reactions of the nitrone with 4b, 5b, and 6b as forward electron density flux (FEDF) reactions. The study of bond evolution theory (BET) reveals that the formation of new C-C and C-O covalent bonds does not initiate in the transition states, as the intermediate stages of these reactions display pseudoradical centers of the atoms already involved in bonding.

Keywords: 4-isoxazoline, DFT/B3LYP-D3, regioselectivity, cycloaddition reaction, MEDT, ELF

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Authors: Elizabeth McLean, Katrina Skewes-McFerran, Grace Thompson

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Scholarship highlights the need to further examine and better understand and foster the process of becoming a parent to a premature baby in the neonatal context to support the critical development of the parent-infant relationship. Music therapy research documents significant benefits of music therapy on neonatal physiological and neurodevelopmental function, reduced maternal anxiety and validating parents’ relationship with their premature baby, yet limited studies examine the role of music in supporting parental identity. This was a multi-site study, exploring parents’ musical engagement with their hospitalised baby and parental identity in a NU. In-depth interviews with nine parents of a premature baby across varying time points in their NU journey took place. Data collection and analysis was influenced by Constructive Grounded Theory methodology. Findings in the form of a substantive grounded theory illuminated the contribution of parents’ musical engagement on their sense of parental identity in the NU. Specifically, the significance of their baby’s level and type of response during musical interactions in influencing parents’ capacity to engage in musical dialogue with their baby emerged. Specific conditions that acted as both barriers and fosters in parents’ musical engagement across a high- risk pregnancy and NU admission also emerged. Recommendations for future research into the role of music and music therapy in supporting parental coping and transition to parenthood during a high-risk pregnancy and birth and beyond the NU will be discussed.

Keywords: grounded theory, musical engagement, music therapy, parental identity

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Authors: M. I. Benamrani, H. Benamrani

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In the research to replace silicon and other thin-film semiconductor technologies and to develop long-term technology that is environmentally friendly, low-cost, and abundant, there is growing interest today given to organic materials. Our objective is to prepare polymeric layers containing metal particles deposited on a surface of semiconductor material which can have better electrical properties and which could be applied in the fields of nanotechnology as an alternative to the existing processes involved in the design of electronic circuits. This work consists in the development of composite materials by complexation and electroreduction of copper in a film of poly (pyrrole benzoic acid). The deposition of the polymer film on a monocrystalline silicon substrate is made by electrochemical oxidation in an organic medium. The incorporation of copper particles into the polymer is achieved by dipping the electrode in a solution of copper sulphate to complex the cupric ions, followed by electroreduction in an aqueous solution to precipitate the copper. In order to prepare the monocrystalline silicon substrate as an electrode for electrodeposition, an in-depth study on its surface state was carried out using photoacoustic spectroscopy. An analysis of the optical properties using this technique on the effect of pickling using a chemical solution was carried out. Transmission-photoacoustic and impedance spectroscopic techniques give results in agreement with those of photoacoustic spectroscopy.

Keywords: photoacoustic, spectroscopy, copper sulphate, chemical solution

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Authors: Prima Luna, Afroditi Chatzifragkou, Dimitris Charalampopoulos

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Sorghum byproducts, namely bran, stalk, and panicle are examples of lignocellulosic biomass. These raw materials contain large amounts of polysaccharides, in particular hemicelluloses, celluloses, and lignins, which if efficiently extracted, can be utilised for the development of a range of added value products with potential applications in agriculture and food packaging sectors. The aim of this study was to characterise fractions extracted from sorghum bran and stalk with regards to their physicochemical properties that could determine their applicability as food-packaging materials. A sequential alkaline extraction was applied for the isolation of cellulosic, hemicellulosic and lignin fractions from sorghum stalk and bran. Lignin content, phenolic content and antioxidant capacity were also investigated in the case of the lignin fraction. Thermal analysis using differential scanning calorimetry (DSC) and X-Ray Diffraction (XRD) revealed that the glass transition temperature (T_g) of cellulose fraction of the stalk was ~78.33 ^oC at amorphous state (~65%) and water content of ~5%. In terms of hemicellulose, the T_g value of stalk was slightly lower compared to bran at amorphous state (~54%) and had less water content (~2%). It is evident that hemicelluloses generally showed a lower thermal stability compared to cellulose, probably due to their lack of crystallinity. Additionally, bran had higher arabinose-to-xylose ratio (0.82) than the stalk, a fact that indicated its low crystallinity. Furthermore, lignin fraction had T_g value of ~93 ^oC at amorphous state (~11%). Stalk-derived lignin fraction contained more phenolic compounds (mainly consisting of p-coumaric and ferulic acid) and had higher lignin content and antioxidant capacity compared to bran-derived lignin fraction.

Keywords: alkaline extraction, bran, cellulose, hemicellulose, lignin, stalk

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Authors: Mohamed Djalil Zaafour, Samir Chekchaki, Mohamed Benslama

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The Landfill of El Matrouha is located in El-Tarf town (extreme north east of Algeria), the Landfill is present as a gigantic wild dump. This waste dump occupies an area of over four hectares, tons of rubbish that is sent daily are scattered over kilometers, reaching farmland located west of the town, the landfill is close to a temporary Oued, which supply Oued Guergour the last tributary Oued El Kebir. The landfills are causing serious environmental damage, following the infiltration of leachates, which contribute to the degradation of water quality, in the context of this problem, the purpose of the work is focused on assessing the impact of this landfill on Oued El-Kebir, for this a series of sampling and analysis of the soil and water of this Oued was performed; The results show that the soil collected reveal the sandy texture facilitating infiltration and percolation of leachate from the landfill; the physicochemical analysis of the quality of the river water reveals high levels of sulfates in fact this element is one of the essential constituents of the mineral fraction of the waste presenting a risk of pollution by this element, The recorded values for nutrients are sub-standard, for trace elements analysis shows very low metal load on the river except for lead, which is present at high concentrations exceeding all standard.

Keywords: Algeria, landfill, leachates, Oued El-kebir

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Authors: Rui Lança, Elisa Silva, Fátima Farinha, Miguel José Oliveira, Manuel Duarte Pinheiro, Cátia Miguel

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Tourism has a great potential to bring up progress across the Sustainable Development Goals (SDGs). If well managed and monitored, the tourism sector can create quality jobs, reduce poorness and offer incentives for environmental preservation, helping on the transition towards more inclusive and resilient economies. However, without proper safeguards and investments, expansion of the tourism market will increase pressure on biodiversity and the ecosystems on which the livelihoods of local communities depend. Competitivity is a key dimension in tourism, sustainable tourism challenge new dimensions to competitivity, namely environmental, social, institutional and economic achieve a medium and long-term competitivity. It is undoubtedly clear on the tourism sector, the importance of the region sustainability in the current touristic destinations offer. The basis of a tourism region prosperity will depend on /of it. The OBSERVE project intends to be an instrument for monitoring and evaluating the sustainability levels of the Algarve region. Its main objective is to provide environmental, economic, social-cultural and institutional indicators to support the decision-making process for a sustainable growth of the region. The project´s main goal is a digital portal with the most relevant indicators to allow evaluating and communicating the performance of the region in a sustainable growth perspective. This paper presents the OBSERVE project and highlights the potential contribution to a broad perspective of competitivity and its contribution for different stakeholders and the touristic value chain. Limitations and opportunities are also discussed.

Keywords: sustainable tourism, competitivity, OBSERVE project, Algarve region

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Authors: Hasan Afarnegan, Ali Shahraki, Jafar Shahraki

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Paraquat is widely used as a strong nitrogen-based herbicide for controlling of weeds in agriculture. This poison is extremely toxic for humans which induces several – organ failure by accumulation in cells and many instances of death occurred due to its poisoning. Paraquat metabolized primarily in the liver. The purpose of this study was to assess the effects of aquatic extract of levisticum officinale on oxidative status and biochemical factors in hepatocytes exposed to paraquat. Our results determined that hepatocytes destruction induced by paraquat is mediated by reactive oxygen species (ROS) production, lipid peroxidation and decrease of mitochondrial membrane potential were significantly (P<0.05) prevented by aquatic extract of Levisicum officinale (100, 200 and 300 µg/ml). These effects of paraquat also prevented via antioxidants and ROS scavengers (α-tocopherol, DMSO, manitol), mitochondrial permeability transition (MPT) pore sealing compound (carnitine).MPT pore sealing compound inhibited the hepatotoxicity, indicating that paraquat induced cell death via mithochondrial pathway. Pretreatment of hepatocytes with aquatic extracts of Levisticum officinale, antioxidants and ROS scavengers also blocked hepatic cell death caused by paraquat, suggesting that oxidative stress may be directly induced decline of mithochondrial membrane potential. In conclusion, paraquat hepatotoxicity can be attributed to oxidative stress and continued by mithochondrial membrane potential disruption. Levisticum officinale aquatic extract, presumably due to its strong antoxidant properties, could protect the destructive effects of paraquat on rat hepatocytes.

Keywords: hepatocyte protection, levisticum officinale, oxidative stress, paraquat

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Authors: Priya Bajaj, Baby Tabassum

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Arsenic is a poisonous metalloid, naturally occurring in soil, air, rocks and ground water. This dreadful metalloid commonly exists as inorganic compound, arsenic trioxide. WHO permitted maximum limit for arsenic in water is 0.01 mg/L, but some affected areas show ground water level of arsenic up to 3 mg/L even. Ground water arsenic pollution has created a number of health problems, viz. keratosis, melanosis, lesions and even skin cancers. The key objective of our nested study was to characterize arsenic induced hepatotoxicity and to find out some herbal protection against it. For the purpose, we selected albino rat (Rattus norvegicus) as model for arsenic induced liver injury and wild turmeric (Curcuma aromatica) leaf extract as remedy for it. The study was performed at acute (1 day) and subacute (7, 14 & 21 days) levels. The LD50 estimated for arsenic trioxide was 14.98 mg/kg body weight. In our investigation, we observed a significant restoration of altered hepatic lipid, cholesterol, protein and glycogen contents as well as liver weight, body-weight and hepato-somatic index by Curcuma aromatica leaf extract before arsenic intoxication. The results reveal excellent protective efficacy of Curcuma aromatica leaf extract that further can be exploited in remediation programme in heavy metal affected areas.

Keywords: arsenic, Curcuma aromatica, glycogen, lipids

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Authors: Xin Chen, Xinyong Li, Qidong Zhao, Dong Wang

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A new coupling system was constructed by combining photo-electrochemical cell with electro-fenton cell (PEC-EF). The electrode material in this system was derived from MnyFe₁₋yCo Prussian-Blue-Analog (PBA). Mn₀.₄Fe₀.₆Co₀.₆₇-N@C spin-coated on carbon paper behaved as the gas diffusion cathode and Mn₀.₄Fe₀.₆Co₀.₆₇O₂.₂ spin-coated on fluorine-tin oxide glass (FTO) as anode. The two separated cells could degrade Sulfamethoxazole (SMX) simultaneously and some coupling mechanisms by PEC and EF enhancing the degradation efficiency were investigated. The continuous on-site generation of H₂O₂ at cathode through an oxygen reduction reaction (ORR) was realized over rotating ring-disk electrode (RRDE). The electron transfer number (n) of the ORR with Mn₀.₄Fe₀.₆Co₀.₆₇-N@C was 2.5 in the selected potential and pH range. The photo-electrochemical properties of Mn₀.₄Fe₀.₆Co₀.₆₇O₂.₂ were systematically studied, which displayed good response towards visible light. The photoinduced electrons at anode can transfer to cathode for further use. Efficient photo-electro-catalytic performance was observed in degrading SMX. Almost 100% SMX removal was achieved in 120 min. This work not only provided a highly effective technique for antibiotic treatment but also revealed the synergic effect between PEC and EF.

Keywords: electro-fenton, photo-electrochemical, synergic effect, sulfamethoxazole

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Authors: 李佳翰, CHIA-HAN LEE

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Without energy, the economy would grind to a halt. Germany's prosperity and security depend on a reliable and affordable energy supply. In recent years, Germany's energy policy has undergone major changes. Due to the sharp turn in energy, Germany cannot extend the service of nuclear power plants and can only find a rapid transition energy source: natural gas for a limited time. This study attempts to use processes of decision entrapment behavior and document analysis to explain research questions. Through primary and secondary information such as official reports, parliamentary minutes, media interview records, and speech records, the author sorted out the important events experienced by the three coalition governments (Gerhard Schröder, Angela Merkel, and Olaf Scholz) and the relationship between Nord Stream 1 and Nord Stream 2 with primary and secondary sources. Also, compare it with the processes of decision entrapment behavior, which designed in this study, and divide it into four stages to explore its key elements one by one. In this regard, the following conclusions are drawn: First, from the perspective of processes of decision entrapment behavior, Merkel’s government firmly believes that she can overcome difficulties because of her past experience in crisis management capabilities. However, the outbreak of war between Ukraine and Russia was beyond Merkel's planning. Second, in the face of the crisis, the Scholz’s government increased the import of natural gas from other countries and began to import liquefied natural gas to make up for the energy gap of Russian natural gas.

Keywords: german research, nord stream gas pipeline, energy policy, processes of decision entrapment behavior

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Authors: Si Yin Tee

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Bimetallic nanostructures have received tremendous interests as a new class of nanomaterials which may have better technological usefulness with distinct properties from those of individual atoms and molecules or bulk matter. They excelled over the monometallic counterparts because of their improved electronic, optical and catalytic performances. The properties and the applicability of these bimetallic nanostructures not only depend on their size and shape, but also on the composition and their fine structure. These bimetallic nanostructures are potential candidates for bio-applications such as biosensing, bioimaging, biodiagnostics, drug delivery, targeted therapeutics, and tissue engineering. Herein, gold-incorporated copper (Cu/Au) nanostructures were synthesized through the controlled disproportionation of Cu⁺-oleylamine complex at 220 ºC to form copper nanowires and the subsequent reaction with Au³⁺ at different temperatures of 140, 220 and 300 ºC. This is to achieve their synergistic effect through the combined use of the merits of low-cost transition and high-stability noble metals. Of these Cu/Au nanostructures, Cu/Au nanotubes display the best performance towards electrochemical non-enzymatic glucose sensing, originating from the high conductivity of gold and the high aspect ratio copper nanotubes with high surface area so as to optimise the electroactive sites and facilitate mass transport. In addition to high sensitivity and fast response, the Cu/Au nanotubes possess high selectivity against interferences from other potential interfering species and excellent reproducibility with long-term stability. By introducing gold into copper nanostructures at a low level of 3, 1 and 0.1 mol% relative to initial copper precursor, a significant electrocatalytic enhancement of the resulting bimetallic Cu/Au nanostructures starts to occur at 1 mol%. Overall, the present fabrication of stable Cu/Au nanostructures offers a promising low-cost platform for sensitive, selective, reproducible and reusable electrochemical sensing of glucose.

Keywords: bimetallic, electrochemical sensing, glucose oxidation, gold-incorporated copper nanostructures

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Authors: Iuliia Riabenko, Konstantin Beloshenko, Sergey Shulga, Valeriy Shulga

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An optical system has been developed consisting of a TIR lens and an aspherical surface designed to collect Stokes radiation from biomolecules. The freeform material is SYLGARD-184, which provides a low level of noise associated with the luminescence of the substrate. The refractive index of SYLGARD-184 is 1.4028 for a wavelength of 632 nm, the Abbe number is 72, these material parameters make it possible to design the desired shape for the wavelength range of 640-700 nm. The system consists of a TIR lens, inside which is placed a high-quality resonant system consisting of a biomolecule and a metal colloid. This system can be described using the coupled oscillator model. The laser excitation radiation was fed through the base of the TIR lens. The sample was mounted inside the TIR lens at a distance of 8 mm from the base. As a result of Raman scattering of laser radiation, a Stokes bend appeared from the biolayer. The task of this work was that it was necessary to collect this radiation emitted at a 4π steradian angle. For this, an internal aspherical surface was used, which made it possible to defocus the beam emanating from the biolayer and direct its radiation to the borders of the TIR lens at the Brewster angle. The collated beam of Stokes radiation contains 97% of the energy scattered by the biolayer. Thus, a simple scheme was proposed for collecting and collimating the Stokes radiation of biomolecules.

Keywords: TIR lens, freeform material, raman scattering, biolayer, brewster angle

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Authors: Morsli Mourad, Tahiri Mohamed, Samdi Azzeddine

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Casablanca is the biggest city in Morocco. It concentrates more than 60% of the economic and industrial activity of the kingdom. Its building and public works (BTP) sector is the leading source of inert waste scattered in open areas. This inert waste is a major challenge for the city of Casablanca, as it is not properly managed, thus causing a significant nuisance for the environment and the health of the population. Hence the vision of our project is to recycle and valorize concrete waste. In this work, we present concrete results in the exploitation of this abundant and permanent deposit. Typical wastes are concrete, clay and concrete bricks, ceramic tiles, marble panels, gypsum, scrap metal, wood . The work performed included: geolocation with a combination of artificial intelligence and Google Earth, estimation of the amount of waste per site, sorting, crushing, grinding, and physicochemical characterization of the samples. Then, we proceeded to the exploitation of the types of substrates to be developed: light cement, coating, and glue for ceramics... The said products were tested and characterized by X-ray fluorescence, specific surface, resistance to bending and crushing, etc. We will present in detail the main results of our research work and also describe the specific properties of each material developed.

Keywords: déchets de démolition et des chantiers de construction, logiciels de combinaison SIG, valorisation de déchets inertes, enduits, ciment leger, casablanca

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Authors: Cangir Uyarlar, E. Eren Gultepe, I. Sadi Cetingul, Ismail Bayram

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This study was conducted to investigate the effect of humic acid (Potassium Humate) at different levels on rations on the effects of both maternal and offspring health, metabolic parameters and immunity levels in transition dairy cows. For this purpose, 50 Holstein dairy cows divided 5 trial groups. Experimental groups were designed as follows: A) Control (0% Humas); B) 0.5 Humas (0,5% in concentrated diet); C) 1 Humas (1% in concentrated diet), D) 1,5 Humas (1,5% in concentrated diet), E) 2 Humas (2% in concentrated diet), respectively. The study lasted from the first day of the dry period to postpartum 30th day. Diets were prepared as isocaloric and isonitrogenic. In the experiment, the day on which the animals gave birth was accepted as ‘0 (zero)’ and blood was taken from tail vein (v. coccygea) at -60, -53, -46, -39, -32, -25, -18, -11, -4, 0, ; Colostrum samples were taken on days 0, 1 and 2; Blood samples were taken on days 0, 1, 2, 15 and 30 from the juguler vein (v. jugularis) of the new born calves. Total blood leukocyte, Lymphocyte, Monocyte, granulocytes, Hemoglobin, Hematocrit, MCV, MCH, MWC, RDW, PLT, MPV, PDW, PCT, NEFA, BHBA, Glucose, Total Cholesterol , Triglyceride, LDL, HDL, VLDL, ALT, AST, ALP, GGT and Total IgG levels and colostrum IgG levels were determined in this experiment. The results suggest that although the supplementation of humic acid at 2% level adversely affected to production parameters, the addition of humic acid (potassium humate) to the concentrate mix during the dry period (particularly 0.5 and 1% levels) may provide an increasing on mother and the offspring immunity, some improving on serum metabolism parameters and enhancing the milk production.

Keywords: humic acid, dairy cow, calf, immunity

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Authors: Sheba Akhtar

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The profound importance that Islam places on knowledge has directly influenced the architectural development of the mosque throughout the Muslim world. The masjid is the most important religious building type in Islamic society because, as a place of worship and social interaction, it is the center of both spiritual knowledge and secular guidance. The Quran begins with the emphatic injunction, “Iqra”, establishing the central importance of the pursuit of the sacred ilm that is offered to man by Allah. Similarly, numerous hadiths of the Prophet Muhammad emphasize the profound importance of the acquisition and dissemination of knowledge, both spiritual and temporal. The Muslim worshipper must enter the sacred space of the masjid to receive spiritual knowledge, but the transition from the profane realm outside the mosque to that of spirituality within is not merely physical; it is also deeply psychological and emotional. To this end, the architecture of the masjid, from the plan and geometry to the design elements and intricate ornamental details, plays a vital role in creating the environment within which the ritual acts of wudu and salat are enacted to foster the transformative journey, from the mundane reality of this world to the realm of spirituality beyond, in the heart, mind, and soul of the worshipper. It is expected that the paper will provide a better understanding of the ways in which sacred Islamic knowledge has influenced the architectural design of the mosque. The research will draw upon Islamic epistemology, Islamic architecture history, and compositional analysis to demonstrate this philosophical, historical, and formal relationship. In this way, the paper will provide a meaningful bridge between the existing knowledge related to mosque design and the expanding academic discourse about the religious architecture of Islam.

Keywords: Islamic architecture, mosque architecture, religious architecture, sacred architecture

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Authors: L. Siva Rama Krishna, Sriram Venkatesh, M. Sastish Kumar, M. Uma Maheswara Chary

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Rapid Prototyping (RP) is a technology that produces models and prototype parts from 3D CAD model data, CT/MRI scan data, and model data created from 3D object digitizing systems. There are several RP process like Stereolithography (SLA), Solid Ground Curing (SGC), Selective Laser Sintering (SLS), Fused Deposition Modelling (FDM), 3D Printing (3DP) among them SLS and FDM RP processes are used to fabricate pattern of custom cranial implant. RP technology is useful in engineering and biomedical application. This is helpful in engineering for product design, tooling and manufacture etc. RP biomedical applications are design and development of medical devices, instruments, prosthetics and implantation; it is also helpful in planning complex surgical operation. The traditional approach limits the full appreciation of various bony structure movements and therefore the custom implants produced are difficult to measure the anatomy of parts and analyse the changes in facial appearances accurately. Cranioplasty surgery is a surgical correction of a defect in cranial bone by implanting a metal or plastic replacement to restore the missing part. This paper aims to do a comparative study on the dimensional error of CAD and SLS RP Models for reconstruction of cranial defect by comparing the virtual CAD with the physical RP model of a cranial defect.

Keywords: rapid prototyping, selective laser sintering, cranial defect, dimensional error

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Authors: Ying Li, Zaisheng Hong, Weihong Wang

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With the rapid enlargement of the size of Chinese universities, newly built campuses are springing up everywhere in recent years. It is urged to build eco-green campus because the role of higher education institutions in the transition to a more sustainable society has been highlighted for almost three decades. On condition that a new campus is usually built on an undeveloped site, where the basic infrastructure is not completed, finding proper strategies in planning and design of the campus becomes a primary concern. Low Impact Development (LID) options have been proposed as an alternative approach to make better use of rainwater in planning and design of an undeveloped site. On the basis of analyzing the natural circumstance, geographic condition, and other relative information, four main LID approaches are coordinated in this study of Hebei Union University, which are ‘Storage’, ‘Retaining’, ‘Infiltration’ and ‘Purification’. ‘Storage’ refers to a big central lake in the campus for rainwater harvesting. ‘Retaining’ means rainwater gardens scattered in the campus, also being known as bioretention areas which mimic the naturally created pools of water, to decrease surface flow runoff. ‘Infiltration’ is designed of grassed swales, which also play a part of floodway channel. ‘Purification’ is known as either natural or artificial wetland to reduce pollutants such as nitrogen and phosphorous in the waterbody. With above mentioned measures dealing with the synthetic use of rainwater in the acid & alkali area in the coastal district, an eco-green campus construction and an ecological sustainability will be realized, which will give us more enlightenment and reference.

Keywords: newly built campus, low impact development, planning design, rainwater reuse

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Authors: Zong-Sheng Chen

Abstract:

With the advancement of technology, human activities have increased greenhouse gas emissions and fossil fuel energy production, leading to increasingly severe global warming. To mitigate global warming, energy conservation and carbon reduction have become global goals. Solar energy, a renewable energy source, not only helps achieve energy conservation and carbon reduction but also serves as an efficient energy generation method. Solar energy, derived from sunlight, is an endless and promising energy source capable of meeting high energy demands sustainably. In recent years, many countries around the world have been developing the solar energy industry, and Taiwan is no exception. Positioned in the subtropical region, Taiwan possesses geographical advantages conducive to solar energy utilization. Furthermore, Taiwan's well-developed semiconductor technology and sophisticated equipment make it highly suitable for the development of high-efficiency solar cells. This study focuses on investigating the anti-reflection properties of solar cells. Through metal-assisted chemical etching, pyramid structures are etched to allow sunlight to pass through, achieving secondary or higher-order reflections on the surface of these structures. This trapping of light within the substrate reduces reflection rates and increases conversion efficiency.

Keywords: solar cell, reflectance, pyramidal structure, potassium hydroxide

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Authors: Lifar M. S., Tereshchenko A. A., Bulgakov A. N., Guda S. A., Guda A. A., Soldatov A. V.

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Metal nanoparticles are widely used as heterogeneous catalysts to activate adsorbed molecules and reduce the energy barrier of the reaction. Reaction product yield depends on the interplay between elementary processes - adsorption, activation, reaction, and desorption. These processes, in turn, depend on the inlet feed concentrations, temperature, and pressure. At stationary conditions, the active surface sites may be poisoned by reaction byproducts or blocked by thermodynamically adsorbed gaseous reagents. Thus, the yield of reaction products can significantly drop. On the contrary, the dynamic control accounts for the changes in the surface properties and adjusts reaction parameters accordingly. Therefore dynamic control may be more efficient than stationary control. In this work, a reinforcement learning algorithm has been applied to control the simulation of CO oxidation on a catalyst. The policy gradient algorithm is learned to maximize the CO₂ production rate based on the CO and O₂ flows at a given time step. Nonstationary solutions were found for the regime with surface deactivation. The maximal product yield was achieved for periodic variations of the gas flows, ensuring a balance between available adsorption sites and the concentration of activated intermediates. This methodology opens a perspective for the optimization of catalytic reactions under nonstationary conditions.

Keywords: artificial intelligence, catalyst, co oxidation, reinforcement learning, dynamic control

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Authors: Chongtham Jiten, K. Chandramani Singh, Radhapiyari Laishram

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Nanocrystalline powders of the lead-free piezoelectric material, tantalum-substituted potassium sodium niobate (K0.5Na0.5)(Nb0.9Ta0.1)O3 (KNNT), were produced using a Retsch PM100 planetary ball mill by setting the milling time to 15h, 20h, 25h, 30h, 35h and 40h, at a fixed speed of 250rpm. The average particle size of the milled powders was found to decrease from 12nm to 3nm as the milling time increases from 15h to 25h, which is in agreement with the existing theoretical model. An anomalous increase to 98nm and then a drop to 3nm in the particle size were observed as the milling time further increases to 30h and 40h respectively. Various sizes of these starting KNNT powders were used to investigate the effect of milling time on the microstructure, dielectric properties, phase transitions and piezoelectric properties of the resulting KNNT ceramics. The particle size of starting KNNT was somewhat proportional to the grain size. As the milling time increases from 15h to 25h, the resulting ceramics exhibit enhancement in the values of relative density from 94.8% to 95.8%, room temperature dielectric constant (εRT) from 878 to 1213, and piezoelectric charge coefficient (d33) from 108pC/N to 128pC/N. For this range of ceramic samples, grain size refinement suppresses the maximum dielectric constant (εmax), shifts the Curie temperature (Tc) to a lower temperature and the orthorhombic-tetragonal phase transition (Tot) to a higher temperature. Further increase of milling time from 25h to 40h produces a gradual degradation in the values of relative density, εRT, and d33 of the resulting ceramics.

Keywords: perovskite, dielectric, ceramics, high-energy milling

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Authors: Syed Atif Hassan, Luv Mehta, Syed Asif Hassan

Abstract:

Hit song science is a field of investigation wherein machine learning techniques are applied to music tracks in order to extract such features from audio signals which can capture information that could explain the popularity of respective tracks. Record companies invest huge amounts of money into recruiting fresh talents and churning out new music each year. Gaining insight into the basis of why a song becomes popular will result in tremendous benefits for the music industry. This paper aims to extract basic musical and more advanced, acoustic features from songs while also taking into account external factors that play a role in making a particular song popular. We use a dataset derived from popular Spotify playlists divided by genre. We use ten genres (blues, classical, country, disco, hip-hop, jazz, metal, pop, reggae, rock), chosen on the basis of clear to ambiguous delineation in the typical sound of their genres. We feed these features into three different classifiers, namely, SVM with RBF kernel, a deep neural network, and a recurring neural network, to build separate predictive models and choosing the best performing model at the end. Predicting song popularity is particularly important for the music industry as it would allow record companies to produce better content for the masses resulting in a more competitive market.

Keywords: classifier, machine learning, music tracks, popularity, prediction

Procedia PDF Downloads 655

Authors: Sridhar S, Govinda Raj Mandela, Aruna Mangalpady

Abstract:

In the present day scenario, Indian underground mines are moving towards full scale mechanisation for improvement of production and productivity levels. These mines are employing a wide variety of earth moving machines for the transportation of ore and overburden (waste). Low Profile Dump Trucks (LPDTs) have proven more advantageous towards improvement of production levels in underground mines through quick transportation. During the operation of LPDT, different kinds of vibrations are generated which can affect the health condition of the operator. Keeping this in view, the present research work focuses on measurement and evaluation of Hand Arm Vibrations (HAVs) from the steering system of LPDTs. The study also aims to evaluate the HAVs of different job components of a work cycle in operating LPDTs. The HAVs were measured and evaluated according to ISO 5349-2: 2001 standards, and the daily vibration exposures A(8) were calculated. The evaluated A(8) results show that LPDTs of 60 and 50 tons capacity have vibration levels more than that of the Exposure Action Value (EAV) of 2.5 m/s2 in every job component of the work cycle. Further, the results show that the vibration levels were more during empty haulage especially during descending journey when compared to other job components in all LPDTs considered for the study.

Keywords: low profile dump trucks, hand arm vibrations, exposure action value, underground mines

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Authors: Mehak Munjal, Raj Kishore Sharma, Gurmeet Singh

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Microbial Fuel Cells (MFCs) are an alternative sustainable approach that utilize bacteria present in waste water as a bio-catalyst for the production of energy. It is a promising growing technology with minimal requirement for chemical supplements. Here electrode material plays a vital role in its performance. The present study represents CoFe2O4 spinel as a novel anode material in the MFC. It not only improve the bacterial metabolics but also enhance the power output. Generally, biocompatible conductive carbon paper/cloth, graphite and stainless steel are utilised as anode in MFCs. However, these materials lack electrochemical activity for anodic microbial reaction. Therefore, we developed CoFe2O4 on graphite sheet which enhanced the anodic charge transfer process. Redox pair in CoFe2O4 helped in improvement of extracellular electron transfer, thereby enhancing the performance. The physical characterizations (FT-IR, XRD, Raman) and electrochemical measurements demonstrate the strong interaction with E.coli bacteria and thus providing an excellent power density i.e. 1850 mW/m2 .The maximum anode half -cell potential is measured to be 0.65V. Therefore, use of noble metal free anodic material further decrease the cost and the long term cell stability makes it an effective material for practical applications.

Keywords: microbial fuel cell, cobalt ferrite, E. coli, bioelectricity

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Authors: Jianguo Chen, Fenggang Zang, Yu Yang, Liangang Zheng

Abstract:

Reactor Pressure Vessel (RPV) is an important security barrier in nuclear power plant. Crack like defects may be produced on RPV during the whole operation lifetime due to the harsh operation condition and irradiation embrittlement. During the severe loss of coolant accident, thermal shock happened as the injection of emergency cooling water into RPV, which results in re-pressurization of the vessel and very high tension stress on the vessel wall, this event called Pressurized Thermal Shock (PTS). Crack on the vessel wall may propagate even penetrate the vessel, so the safety of the RPV would undergo great challenge. Many assumptions in structure integrity evaluation make the result of deterministic fracture mechanics very conservative, which affect the operation lifetime of the plant. Actually, many parameters in the evaluation process, such as fracture toughness and nil-ductility transition temperature, have statistical distribution characteristics. So it is necessary to assess the structural integrity of RPV subjected to PTS event by means of Probabilistic Fracture Mechanics (PFM). Structure integrity evaluation methods of RPV subjected to PTS event are summarized firstly, then evaluation method based on probabilistic fracture mechanics are presented by considering the probabilistic characteristics of material and structure parameters. A comprehensive analysis example is carried out at last. The results show that the probability of crack penetrates through wall increases gradually with the growth of fast neutron irradiation flux. The results give advice for reactor life extension.

Keywords: fracture toughness, integrity evaluation, pressurized thermal shock, probabilistic fracture mechanics, reactor pressure vessel

Procedia PDF Downloads 247

Authors: F. Zouai, F. Z. Benabid, S. Bouhelal, D. Benachour

Abstract:

Reinforced plastics or nanocomposites have attracted considerable attention in scientific and industrial fields because a very small amount of clay can significantly improve the properties of the polymer. The polymeric matrices used in this work are two saturated polyesters, i.e., polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). The success of processing compatible blends, based on poly(ethylene terephthalate) (PET)/poly(ethylene naphthalene) (PEN)/clay nanocomposites in one step by reactive melt extrusion is described. Untreated clay was first purified and functionalized ‘in situ’ with a compound based on an organic peroxide/ sulfur mixture and (tetramethylthiuram disulfide) as the activator for sulfur. The PET and PEN materials were first separately mixed in the molten state with functionalized clay. The PET/4 wt% clay and PEN/7.5 wt% clay compositions showed total exfoliation. These compositions, denoted nPET and nPEN, respectively, were used to prepare new n(PET/PEN) nanoblends in the same mixing batch. The n(PET/PEN) nanoblends were compared to neat PET/PEN blends. The blends and nanocomposites were characterized using various techniques. Microstructural and nanostructural properties were investigated. Fourier transform infrared spectroscopy (FTIR) results showed that the exfoliation of tetrahedral clay nanolayers is complete, and the octahedral structure totally disappears. It was shown that total exfoliation, confirmed by wide-angle X-ray scattering (WAXS) measurements, contributes to the enhancement of impact strength and tensile modulus. In addition, WAXS results indicated that all samples are amorphous. The differential scanning calorimetry (DSC) study indicated the occurrence of one glass transition temperature Tg, one crystallization temperature Tc and one melting temperature Tm for every composition.

Keywords: exfoliation, DRX, DSC, montmorillonite, nanocomposites, PEN, PET, plastograph, reactive melt-mixing

Procedia PDF Downloads 322