Search results for: geomagnetically induced currents

Authors: Djehich Mohamed Yousri

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The national sovereignty of states is now facing a dangerous situation that has witnessed a clear exacerbation of the restrictions that this sovereignty has known for quite some time, if not since the establishment of the sovereign national state in the first place, and things have reached this way to the extent that a group of analysts and commentators are talking about the demise or disappearance of the phenomenon of sovereignty Patriotism, a judgment that some consider exaggerated, although there is agreement on the seriousness of what has afflicted the national sovereignty of medium and small states in particular. In fact, the phenomenon of national sovereignty has not completely ended, as there is still a category of countries that are able to disagree with the American will without disappearing from the world map, as happened with the Soviet Union. China, some European countries, and some countries with leading regional roles are still able to deal with This administration, with rational and complex calculations, makes the restrictions on its sovereignty minimal, or at least draws a red line in front of the vital interests of those countries that the restrictions on sovereignty cannot cross, and it is certain that strengthening internal democratic development in countries will increase their ability to challenge external restrictions. On its sovereignty to the extent that this development creates a cohesive society in the face of external hegemony attempts, as well as to the extent that it eliminates some pretexts for interference in the internal affairs of states, including the claim of a lack of democracy or lack of respect for human rights in it. What led to transformations in the international arena in the wake of globalization and its effects on international aspects, including national sovereignty and the principle of state independence. Which was marred by several currents, which led to affecting it in a negative way, and this is what poor countries suffer from at the expense of rich countries, which led us to research the extent of the presence of national sovereignty on the international arena, and the extent to which the principle of non-interference in affairs is applied or existed. The internal affairs of states, which are stipulated in the Charter of the United Nations in the modern era, the theory of sovereignty has been subjected to substantial criticism and abandonment by many on the grounds that it is inconsistent with the current conditions of the international community. In fact, the theory of sovereignty has been misused to justify internal tyranny and international chaos. This theory has hindered the development of international law, the work of international organizations and the dominance of strong states over weak ones. At the present time, the concept of sovereignty has moved towards direction, as the transformations of the international system in the economic, political and military fields have led to the decline and erosion of the idea of the sovereignty of the national state.

Keywords: sovereignty, intervention, non-interference, globalization, humanitarian intervention

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Authors: Meihua Fang, Yipan Guo, Tao Fei, Pengyu Tian

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Space plasma caused spacecraft surface charging is the major space environment hazard. Particle in cell (PIC) method can be used to simulate the interaction between space plasma and spacecraft. It was proved that surface charging level of spacecraft in Jupiter’s orbits was high for its’ electron-heavy plasma environment. In this paper, Jovian plasma environment is modeled and surface charging analysis is carried out by PIC based software Spacecraft Plasma Interaction System (SPIS). The results show that the spacecraft charging potentials exceed 1000V at 2Rj, 15Rj and 25Rj polar orbits in the dark side at worst case plasma model. Furthermore, the simulation results indicate that the large Jovian magnetic field increases the surface charging level for secondary electron gyration.

Keywords: Jupiter, PIC, space plasma, surface charging

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Authors: Arunporn Itharat, Srisopa Ruangnoo, Pakakrong Thongdeeying

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The rhizomes of Dioscorea membranacea (DM) has long been used in Thai Traditional medicine to treat cancer and inflammatory conditions such as rheumatism. The objective of this study was to investigate anti-inflammatory activity by determining the inhibitory effect on LPS-induced TNF-α from RAW264.7 cells of crude extracts and pure isolated compounds from DM. Three known dihydrophenantrene compounds were isolated by a bioassay guided isolation method from DM ethanolic extract [2,4 dimethoxy-5,6-dihydroxy-9,10-dihydrophenanthrene (1) and 5-hydroxy-2,4,6-trimethoxy-9,10-dihydrophenanthrene(2) and 5,6,2 -trihydroxy 3,4-methoxy, 9,10- dihydrophenanthrene (3)]. 1 showed the highest inhibitory effect on PGE2, followed by 3 and 1 (IC50 = 2.26, 4.97 and >20 μg/ml or 8.31,17.25 and > 20 µM respectively). These findings suggest that this plant showed anti-inflamatory effects by displaying an inhibitory effect on TNF-α release, hence, this result supports the usage of Thai traditional medicine to treat inflammation related diseases.

Keywords: Dioscorea membranacea, anti-inflammatory activity, TNF-Alpha , dihidrophenantrene compound

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Authors: Aliyu Aminu Baba

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Ethnic entrepreneurship is defined as a set of connections and regular patterns of interaction among people sharing common national background or migration experience. The disadvantage faced by ethnic minority on paid labour induced them to become self-employed. Also, enclaves motivates trading, creativity, innovation are all to provide specific service or products to certain people. These ethnic minorities are African –Caribbean, Indians, Pakistanis, Banghaladashi and Chinese. For policy development ethnic diversity was among the problem of developing policy in United Kingdom. The study finds that there is a danger in treating all ethnic minority businesses as homogeneous rather than heterogeneous. The diversity is due to religious beliefs, culture and race. This indicates that there is a wide range have shortfall in addressing the peculiarities of ethnic minority businesses in policy formulation. Also, there are differences between ethnic minorities in accessing finance. It is recommended that diversity and peculiarities between ethnic minorities should be considered in policy formulation.

Keywords: ethnic entrepreneurship, finance, policy implication, diversity

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Authors: Tahir Saleem, Mohammad Usman, Nadeem Khan

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GPS signals are used for navigation and positioning purposes by a diverse set of users. However, this project intends to utilize the reflected GPS L5 signals for location of target in a region of interest by generating an image that highlights the positions of targets in the area of interest. The principle of bi-static radar is used to detect the targets or any movement or changes. The idea is confirmed by the results obtained during MATLAB simulations. A matched filter based technique is employed in the signal processing to improve the system resolution. The simulation is carried out under different conditions with moving receiver and targets. Noise and attenuation is also induced and atmospheric conditions that affect the direct and reflected GPS signals have been simulated to generate a more practical scenario. A realistic GPS L5 signal has been simulated, the simulation results verify that the detection and imaging of targets is possible by employing reflected GPS using L5 signals and matched filter processing technique with acceptable spatial resolution.

Keywords: GPS, L5 Signal, SAR, spatial resolution

Procedia PDF Downloads 519

Authors: Saiyed M Ishtiaque, Priyal Dixit

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Objectives: An approach is being suggested to design the filter media to maximize the filtration efficiency with minimum possible pressure drop of composite nonwoven by incorporating the layers of different packing densities induced by fibre of different deniers and punching parameters by using the concept of sequential punching technique in specific order in layered composite nonwoven structure. X-ray computed tomography technique is used to measure the packing density along the thickness of layered nonwoven structure composed by placing the layer of differently oriented fibres influenced by fibres of different deniers and punching parameters in various combinations to minimize the pressure drop at maximum possible filtration efficiency. Methodology Used: This work involves preparation of needle punched layered structure with batts 100g/m2 basis weight having fibre denier, punch density and needle penetration depth as variables to produce 300 g/m2 basis weight nonwoven composite. X-ray computed tomography technique is used to measure the packing density along the thickness of layered nonwoven structure composed by placing the layers of differently oriented fibres influenced by considered variables in various combinations. to minimize the pressure drop at maximum possible filtration efficiencyFor developing layered nonwoven fabrics, batts made of fibre of different deniers having 100g/m2 each basis weight were placed in various combinations. For second set of experiment, the composite nonwoven fabrics were prepared by using 3 denier circular cross section polyester fibre having 64 mm length on needle punched nonwoven machine by using the sequential punching technique to prepare the composite nonwoven fabrics. In this technique, three semi punched fabrics of 100 g/m2 each having either different punch densities or needle penetration depths were prepared for first phase of fabric preparation. These fabrics were later punched altogether to obtain the overall basis weight of 300 g/m2. The total punch density of the composite nonwoven fabric was kept at 200 punches/ cm2 with a needle penetration depth of 10 mm. The layered structures so formed were subcategorised into two groups- homogeneous layered structure in which all the three batts comprising the nonwoven fabric were made from same denier of fibre, punch density and needle penetration depth and were placed in different positions in respective fabric and heterogeneous layered structure in which batts were made from fibres of different deniers, punch densities and needle penetration depths and were placed in different positions. Contributions: The results concluded that reduction in pressure drop is not derived by the overall packing density of the layered nonwoven fabric rather sequencing of layers of specific packing density in layered structure decides the pressure drop. Accordingly, creation of inverse gradient of packing density in layered structure provided maximum filtration efficiency with least pressure drop. This study paves the way for the possibility of customising the composite nonwoven fabrics by the incorporation of differently oriented fibres in constituent layers induced by considered variablres for desired filtration properties.

Keywords: filtration efficiency, layered nonwoven structure, packing density, pressure drop

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Authors: Jhoga Parth, T. Nasar, K. V. Anand

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An idealized definition of shoreline is that it is the zone of coincidence of three spheres such as atmosphere, lithosphere, and hydrosphere. Despite its apparent simplicity, this definition in practice a challenge to apply. In reality, the shoreline location deviates continually through time, because of various dynamic factors such as wave characteristics, currents, coastal orientation and the bathymetry, which makes the shoreline volatile. This necessitates us to monitor the shoreline in a temporal basis. If shoreline’s nature is understood at particular coastal stretch, it need not be the same trend at the other location, though belonging to the same sea front. Shoreline change is hence a local phenomenon and has to be studied with great intensity considering as many factors involved as possible. Erosion and accretion of sediment are such natures of a shoreline, which needs to be quantified by comparing with its predeceasing variations and understood before implementing any coastal projects. In recent years, advent of Global Positioning System (GPS) and Geographic Information System (GIS) acts as an emerging tool to quantify the intra and inter annual sediment rate getting accreted or deposited compared to other conventional methods in regards with time was taken and man power. Remote sensing data, on the other hand, paves way to acquire historical sets of data where field data is unavailable with a higher resolution. Short term and long term period shoreline change can be accurately tracked and monitored using a software residing in GIS - Digital Shoreline Analysis System (DSAS) developed by United States Geological Survey (USGS). In the present study, using DSAS, End Point Rate (EPR) is calculated analyze the intra-annual changes, and Linear Rate Regression (LRR) is adopted to study inter annual changes of shoreline. The shoreline changes are quantified for the scenario during the construction of breakwater in Ponnani river inlet along Kerala coast, India. Ponnani is a major fishing and landing center located 10°47’12.81”N and 75°54’38.62”E in Malappuram district of Kerala, India. The rate of erosion and accretion is explored using satellite and field data. The full paper contains the rate of change of shoreline, and its analysis would provide us understanding the behavior of the inlet at the study area during the construction of the training walls.

Keywords: DSAS, end point rate, field measurements, geo-informatics, shoreline variation

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Authors: Tayebeh Sahraeibelverdi, Ahmad Shirazi Hadi Veladi, Mazdak Radmalekshah

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Optical sensors became attractive due to preciseness, low power consumption, and intrinsic electromagnetic interference-free characteristic. Among the waveguide optical sensors, cavity-based ones attended for the high Q-factor. Micro ring resonators as a potential platform have been investigated for various applications as biosensors to pressure sensors thanks to their sensitive ring structure responding to any small change in the refractive index. Furthermore, these small micron size structures can come in an array, bringing the opportunity to have any of the resonance in a specific wavelength and be addressed in this way. Another exciting application is applying a strain to the ring and making them an optical strain gauge where the traditional ones are based on the piezoelectric material. Making them in arrays needs electrical wiring and about fifty times bigger in size. Any physical element that impacts the waveguide cross-section, Waveguide elastic-optic property change, or ring circumference can play a role. In comparison, ring size change has a larger effect than others. Here an engineered ring structure is investigated to study the strain effect on the ring resonance wavelength shift and its potential for more sensitive strain devices. At the same time, these devices can measure any strain by mounting on the surface of interest. The idea is to change the" O" shape ring to a "C" shape ring with a small opening starting from 2π/360 or one degree. We used the Mode solution of Lumbrical software to investigate the effect of changing the ring's opening and the shift induced by applied strain. The designed ring radius is a three Micron silicon on isolator ring which can be fabricated by standard complementary metal-oxide-semiconductor (CMOS) micromachining. The measured wavelength shifts from1-degree opening of the ring to a 6-degree opening have been investigated. Opening the ring for 1-degree affects the ring's quality factor from 3000 to 300, showing an order of magnitude Q-factor reduction. Assuming a strain making the ring-opening from 1 degree to 6 degrees, our simulation results showing negligible Q-factor reduction from 300 to 280. A ring resonator quality factor can reach up to 108 where an order of magnitude reduction is negligible. The resonance wavelength shift showed a blue shift and was obtained to be 1581, 1579,1578,1575nm for 1-, 2-, 4- and 6-degree ring-opening, respectively. This design can find the direction of the strain-induced by applying the opening on different parts of the ring. Moreover, by addressing the specified wavelength, we can precisely find the direction. We can open a significant opportunity to find cracks and any surface mechanical property very specifically and precisely. This idea can be implemented on polymer ring resonators while they can come with a flexible substrate and can be very sensitive to any strain making the two ends of the ring in the slit part come closer or further.

Keywords: optical ring resonator, strain gauge, strain sensor, surface mechanical property analysis

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Authors: Pankaj Dinesh Baviskar

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This study examines the impact of curcumin-loaded nano-spheres in the form of emulsions on fish eye cataracts. Curcumin nanoemulsions were prepared by using phenethyl isothiocyanate. Nanoemulsions were synthesized by ultrasound-assisted method at 150 Watt. A zeta potential measurement for curcumin-loaded nanoemulsions was found to be -30.7eV, -13.4eV, and -9.55eV, and particle size was found to be 149.3 nm, 245.3 and nm 403.5 nm using particle size analyzer respectively for different conditions. The surface morphology of nano-spheres was examined by FE-SEM analysis. The zeta potential measured indicates its stability for corresponding nano-spheres. The anti-cataract application was studied by using isolated fish eye lenses. The cataract was induced using high glucose concentrated solution. The biochemical parameters in the form of reduced glutathione were measured to interpret the anti-cataract ability of curcumin-loaded nanoemulsions.

Keywords: curcumin, nano, cataract, nanoemulsion

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Authors: A. Shaygani, R. Saifi, M. S. Saidi, M. Sani

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Particle size distribution, the most important characteristics of aerosols, is obtained through electrical characterization techniques. The dynamics of charged nano-particles under the influence of electric field in electrical mobility spectrometer (EMS) reveals the size distribution of these particles. The accuracy of this measurement is influenced by flow conditions, geometry, electric field and particle charging process, therefore by the transfer function (transfer matrix) of the instrument. In this work, a wire-cylinder corona charger was designed and the combined field-diffusion charging process of injected poly-disperse aerosol particles was numerically simulated as a prerequisite for the study of a multi-channel EMS. The result, a cloud of particles with non-uniform charge distribution, was introduced to the EMS. The flow pattern and electric field in the EMS were simulated using computational fluid dynamics (CFD) to obtain particle trajectories in the device and therefore to calculate the reported signal by each electrometer. According to the output signals (resulted from bombardment of particles and transferring their charges as currents), we proposed a modification to the size of detecting rings (which are connected to electrometers) in order to evaluate particle size distributions more accurately. Based on the capability of the system to transfer information contents about size distribution of the injected particles, we proposed a benchmark for the assessment of optimality of the design. This method applies the concept of Von Neumann entropy and borrows the definition of entropy from information theory (Shannon entropy) to measure optimality. Entropy, according to the Shannon entropy, is the ''average amount of information contained in an event, sample or character extracted from a data stream''. Evaluating the responses (signals) which were obtained via various configurations of detecting rings, the best configuration which gave the best predictions about the size distributions of injected particles, was the modified configuration. It was also the one that had the maximum amount of entropy. A reasonable consistency was also observed between the accuracy of the predictions and the entropy content of each configuration. In this method, entropy is extracted from the transfer matrix of the instrument for each configuration. Ultimately, various clouds of particles were introduced to the simulations and predicted size distributions were compared to the exact size distributions.

Keywords: aerosol nano-particle, CFD, electrical mobility spectrometer, von neumann entropy

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Authors: Bharat Kumar, Deepak Kumar, Vijay Chaudhry

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Zirconium alloys are generally used for designing the core components of nuclear reactors due to their good mechanical and tribological properties. Some core components are subjected to flow-induced vibrations resulting in wear of these components due to their interaction with one another. To simulate these conditions, low amplitude reciprocating wear tests are conducted at room temperature and high temperature (260 degrees Celsius) between Zr-2.5Nb alloy and SS-410. The tests are conducted at a frequency range of 5 Hz to 25 Hz and an amplitude range of 200 µm to 600 µm. Friction and wear responses were recorded and correlated with the change in parameters. Worn surfaces are analysed using scanning electron microscopy (SEM) and optical profilometer. Elemental changes on the worn surfaces were determined using energy dispersive spectroscopy (EDS). The coefficient of friction (COF) increases with increasing temperature and decreases with increasing frequency. Adhesive wear is found to be the dominant wear mechanism which increases at high temperature.

Keywords: nuclear reactor, Zr-2.5Nb, SS-410, friction and wear

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Authors: Ali Fadhel Ahmed, Tuqa Abdulkareem Hameed

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Moringa oleifera (leaves and seeds) ethanolic and aqueous extracts were tested for antibacterial activity. The effect of plant extracts on three types of bacterial species: Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae, was investigated. Using the agar well diffusion method, ethanolic extracts of Moringa oleifera demonstrated a significant antibacterial effect on the forty tested bacterial strains. Seed-induced inhibition zones (ethanolic extracts)were ranged from16 to 24 mm in diameter against S. aureus, respectively, whileE. coli and K. pneumonia had no effect. Gram-positive and Gram-negative bacteria were not affected by alcoholic and aqueous plant leaf extracts. The purpose of this present study was to look at the cytotoxic effects of M.Oleifera plant (alcoholic extracts).

Keywords: moringa oleifera, escherichia coli, klebsiella pneumoniae, staphylococcus aureus

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Authors: Thomas Rowan, Mohammed Seaid

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A fast finite volume solver for multi-layered shallow water flows with mass exchange and an erodible bed is developed. This enables the user to solve a number of complex sediment-based problems including (but not limited to), dam-break over an erodible bed, recirculation currents and bed evolution as well as levy and dyke failure. This research develops methodologies crucial to the under-standing of multi-sediment fluvial mechanics and waterway design. In this model mass exchange between the layers is allowed and, in contrast to previous models, sediment and fluid are able to transfer between layers. In the current study we use a two-step finite volume method to avoid the solution of the Riemann problem. Entrainment and deposition rates are calculated for the first time in a model of this nature. In the first step the governing equations are rewritten in a non-conservative form and the intermediate solutions are calculated using the method of characteristics. In the second stage, the numerical fluxes are reconstructed in conservative form and are used to calculate a solution that satisfies the conservation property. This method is found to be considerably faster than other comparative finite volume methods, it also exhibits good shock capturing. For most entrainment and deposition equations a bed level concentration factor is used. This leads to inaccuracies in both near bed level concentration and total scour. To account for diffusion, as no vertical velocities are calculated, a capacity limited diffusion coefficient is used. The additional advantage of this multilayer approach is that there is a variation (from single layer models) in bottom layer fluid velocity: this dramatically reduces erosion, which is often overestimated in simulations of this nature using single layer flows. The model is used to simulate a standard dam break. In the dam break simulation, as expected, the number of fluid layers utilised creates variation in the resultant bed profile, with more layers offering a higher deviation in fluid velocity . These results showed a marked variation in erosion profiles from standard models. The overall the model provides new insight into the problems presented at minimal computational cost.

Keywords: erosion, finite volume method, sediment transport, shallow water equations

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Authors: Werner Grommes

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Intelligent wearables (illuminated vests or hand and foot-bands, smart watches with a laser diode, Bluetooth smart glasses) overflow the market today. They are integrated with complex electronics and are worn very close to the body. Optical measurements and limitation of the maximum light density are needed. Smart watches are equipped with a laser diode or control different body currents. Special glasses generate readable text information that is received via radio transmission. Small high-performance batteries (lithium-ion/polymer) supply the electronics. All these products have been tested and evaluated for risk. These products must, for example, meet the requirements for electromagnetic compatibility as well as the requirements for electromagnetic fields affecting humans or implant wearers. Extensive analyses and measurements were carried out for this purpose. Many users are not aware of these risks. The result of this study should serve as a suggestion to do it better in the future or simply to point out these risks. Commercial LED warning vests, LED hand and foot-bands, illuminated surfaces with inverter (high voltage), flashlights, smart watches, and Bluetooth smart glasses were checked for risks. The luminance, the electromagnetic emissions in the low-frequency as well as in the high-frequency range, audible noises, and nervous flashing frequencies were checked by measurements and analyzed. Rechargeable lithium-ion or lithium-polymer batteries can burn or explode under special conditions like overheating, overcharging, deep discharge or using out of the temperature specification. Some risk analysis becomes necessary. The result of this study is that many smart wearables are worn very close to the body, and an extensive risk analysis becomes necessary. Wearers of active implants like a pacemaker or implantable cardiac defibrillator must be considered. If the wearable electronics include switching regulators or inverter circuits, active medical implants in the near field can be disturbed. A risk analysis is necessary.

Keywords: safety and hazards, electrical safety, EMC, EMF, active medical implants, optical radiation, illuminated warning vest, electric luminescent, hand and head lamps, LED, e-light, safety batteries, light density, optical glare effects

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Authors: Khaled Saeed Ali

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This study was conducted with 3 week old domestic chicken to determine the effect of supplementation of cadmium to dietary. 10 mg/kg Cadmium chloride added to maize- sesame cake meal diet for 4 weeks. The additional cadmium to the diet induced a decreasing body weight and changes in biochemical parameters of chicken. Chicken were divided into two groups. The first group was given a diet containing the concentration of 10 mg cadmium /kg daily for a period of 30 days and the second group was given diet without cadmium and used as a control group. The result revealed decrease in the body weight of treated chicken by 12.7 % compared to control group, whose body weight increased. The plasma glucose concentration, creatinine, aspartate aminotranseferase (AST), and alanine aminotransferase (ALT) were increased significantly (P<0.05) in Cd treated chicken in comparison to the control group. Cadmium accumulation was observed in the intestine, kidney, liver and bone. The accumulation of cadmium was markedly higher (3-4 times) in cadmium-treated animals compared to the control.

Keywords: cadmium, biochemical parameters, body weight, chicken

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Authors: Robin Molinier

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Industrial symbiosis (I.S) deals with the exchange of waste materials, fatal energy and utilities as resources for production. While it brings environmental benefits from resource conservation its economic profitability is one of the main barriers to its implementation. I.S involves several actors with their own objectives and resources so that each actor must be satisfied by ex-ante arrangements to commit toward investments and transactions. Regarding I.S Transaction cost economics helps to identify hybrid forms of governance for transactions governance due to I.S projects specificities induced by the need for customization (asset specificity, non-homogeneity). Thus we propose a framework to analyze the best contractual practices tailored to address I.S specific risks that we identified as threefold (load profiles and quality mismatch, value fluctuations). Schemes from cooperative game theory and contracting management are integrated to analyze value flows between actors. Contractual guidelines are then proposed to address the identified risks and to split the value for a set of I.S archetypes drawn from actual experiences.

Keywords: contracts, economics, industrial symbiosis, risks

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Authors: Huseyin Apdik, Aysegul Dogan, Selami Demirci, Ezgi Avsar Apdik, Fikrettin Sahin

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Mesenchymal stem cells (MSCs) are crucial cell types for bone maintenance and growth along with resident bone progenitor cells providing bone tissue integrity during osteogenesis and skeletal growth. Any deficiency in this regulation would result in vital bone diseases. Of those, osteoporosis, characterized by a reduction in bone mass and mineral density, is a critical skeletal disease for especially elderly people. The commonly used drugs for the osteoporosis treatment are bisphosphonates (BPs). The most prominent role of BPs is to prevent bone resorption arisen from high osteoclast activity. However, administrations of bisphosphonates may also cause bisphosphonate-induced osteonecrosis of the jaw (BIONJ). Up to the present, the researchers have proposed several circumstances for BIONJ. However, effects of long-term and/or high dose usage of BPs on stem cell’s proliferation, survival, differentiation or maintenance capacity have not been evaluated yet. The present study will be held to; figure out BPs’ effects on MSCs in vitro in the aspect of cell proliferation and toxicity, migration, angiogenic activity, lineage specific gene and protein expression levels, mesenchymal stem cell properties and potential signaling pathways affected by BP treatment. Firstly, mesenchymal stem cell characteristics of Dental Pulp Stem Cells (DPSCs) and Periodontal Ligament Stem Cells (PDLSCs) were proved using flow cytometry analysis. Cell viability analysis was completed to determine the cytotoxic effects of BPs (Zoledronate (Zol), Alendronate (Ale) and Risedronate (Ris)) on DPSCs and PDLSCs by the 3-(4,5-di-methyl-thiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfo-phenyl)-2H-tetrazolium (MTS) assay. Non-toxic concentrations of BPs were determined at 24 h under growth condition, and at 21 days under osteogenic differentiation condition for both cells. The scratch assay was performed to evaluate their migration capacity under the usage of determined of BPs concentrations at 24 h. The results revealed that while the scratch closure is 70% in the control group for DPSCs, it was 57%, 66% and 66% in Zol, Ale and Ris groups, respectively. For PDLSs, while wound closure is 71% in control group, it was 65%, 66% and 66% in Zol, Ale and Ris groups, respectively. As future experiments, tube formation assay and aortic ring assay will be done to determinate angiogenesis abilities of DPSCs and PDLSCs treated with BPs. Expression levels of osteogenic differentiation marker genes involved in bone development will be determined using real time-polymerase change reaction (RT-PCR) assay and expression profiles of important proteins involved in osteogenesis will be evaluated using western blotting assay for osteogenically differentiated MSCs treated with or without BPs. In addition to these, von Kossa staining will be performed to measure calcium mineralization status of MSCs.

Keywords: bisphosphonates, bisphosphonate-induced osteonecrosis of the jaw, mesenchymal stem cells, osteogenesis

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Authors: T. C. Bera, A. Bansal, D. Nema

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During performing turning operation, cutting force plays a significant role in metal cutting process affecting tool-work piece deflection, vibration and eventually part quality. The present research work aims to develop a mechanistic cutting force model and to study the mechanistic constants used in the force model in case of turning operation. The proposed model can be used for the reliable and accurate estimation of the cutting forces establishing relationship of various force components (cutting force and feed force) with uncut chip thickness. The accurate estimation of cutting force is required to improve thin-walled part accuracy by controlling the tool-work piece deflection induced surface errors and tool-work piece vibration.

Keywords: turning, cutting forces, cutting constants, uncut chip thickness

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Authors: Chih-Chang Yeh, Min-Fang Yang, Hsin-I Chang

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Chitosan is a cationic polysaccharide derived from the partial deacetylation of chitin. Hyaluronic acid (HA), chondroitin sulfate (CS) and heparin (HP) are anionic glycosaminoglycans (GCGs) which can regulate osteogenic activity. In this study, chitosan membranes were prepared by glutaraldehyde crosslinking reaction and then complexed with three different types of GCGs. 7F2 osteoblasts-like cells and macrophages Raw264.7 were used as models to study the influence of chitosan membranes on osteometabolism. Although chitosan membranes are highly hydrophilic, the membranes associated with GCG-chitosan complexes showed about 60-70% cell attachment. Furthermore, the membranes associated with HP-chitosan complexes could increase ALP activity in comparison with chitosan films only. Three types of the membranes associated with GCG-chitosan complexes could significantly inhibit LPS induced-nitric oxide expression. In addition, chitosan membranes associated with HP and HA can down-regulate tartrate-resistant acid phosphatase (TRAP) activity but not CS-chitosan complexes. Based on these results, we conclude that chitosan membranes associated with HP can increase ALP activity in osteoblasts and chitosan membranes associated with HP and HA reduce TRAP activity in osteoclasts.

Keywords: osteoblast, osteoclast, chitosan, glycosaminoglycan

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Authors: Balwinder Singh, Veerpaul Kaur Mann

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The COVID-19 had a dramatic impact on several countries across the world. National governments have imposed widespread restrictions to prevent the growth of this pandemic. The new health competitive scenario induced by the COVID-19 crisis raised many issues on how business activities should be reorganized due to the difficulties of physical interactions with distributors, suppliers and customers. The pandemic has particularly affected the whole marketing processes because of the relevant issues emerged in managing physical sale channels and interactions with one another, both in the Business-to-Consumer and in the Business-to-Business markets. Recent research about the appropriate actions and strategies that could help firms overcome the crisis has highlighted the key role of digital technologies that may ensure connections and, thus, help business activities to run smoothly. This could be true, especially with the emergence of strong limitations on physical interactions during the COVID-19 pandemic. In such a scenario, the online channel becomes the most important conducive for online customers to get in contact with the firm and carry out online purchasing activities.

Keywords: COVID-19, business, digital marketing, online customers

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Authors: M. Al Azri, M. Elzain, K. Bouziane, S. M. Chérif

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n-Type 6H-SiC(0001) substrates were implanted with three fluencies of Mn+ 5x1015 Mn/cm2 (Mn content: 0.7%), 1x1016 (~2 %), and 5x1016 cm–2 (7%) with implantation energy of 80 keV and substrate temperature of 365ºC. The samples were characterized using Rutherford Backscattering and Channeling Spectroscopy (RBS/C), High-Resolution X-Ray Diffraction technique (HRXRD), micro-Raman Spectroscopy (μRS), and Superconducting Quantum Interference Device (SQUID) techniques. The aim of our work is to investigate implantation induced defects with dose and to study any correlation between disorder-composition and magnetic properties. In addition, ab-initio calculations were used to investigate the structural and magnetic properties of Mn-doped 6H-SiC. Various configurations of Mn sites and vacancy types were considered. The calculations showed that a substitutional Mn atom at Si site possesses larger magnetic moment than Mn atom at C site. A model is introduced to explain the dependence of the magnetic structure on site occupation. The magnetic properties of ferromagnetically (FM) and antiferromagnetically (AFM) coupled pairs of Mn atoms with and without neighboring vacancies have also been explored.

Keywords: ab-initio calculations, diluted magnetic semiconductors, magnetic properties, silicon carbide

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Authors: Alvarez Barrantes, Robert Dorrell, Christopher Hackney, Anne Baar, Roberto Fernandez, Daniel Parsons

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Microplastic particles entering fluvial environments are deposited with natural sediments. Their settling properties can change by the absorption or adsorption of contaminants, organic matter, and organisms. These deposits include positively, neutrally, and negatively buoyant particles. This study aims to understand how plastic particles of different densities interact with natural sediments as they settle and how they are stored within the sediment deposit. The results of this study contribute to a better understanding of the deposition of microplastic particles and associated pollution in rivers. A set of 48 experiments was designed to investigate the settling process of microplastic particles in freshwater. The experimental work describes the vertical variation of cohesive and/or non-cohesive sediment versus microplastic densities in deposited sediment. The experiment consisted of adding microplastic particles, sediment, and water in a waterproof carton tube of a height of 24 cm and a diameter of 5 cm. The plastic selected is positively, neutrally, and negatively buoyant. The sediments consist of sand and clay with four different concentrations. The mixture of materials was shaken until is thoroughly mixed and left to settle for 24 hours. After the settlement, the tubes were frozen at -20 °C to be able to cut them and measure the thickness of the deposits and analyze the sediment and plastic distribution. The most representative experiments were repeated in a glass tube of the same size; to analyse the influences of current flows and depositional process. Finally, the glass tube experiments were used to study organic materials adsorption in plastic, settling the sample for four months. Defined microplastic layers were identified as the density of the plastic change. Preliminary results show that most of the positive buoyancy particles floated, neutral buoyancy particles form a layer above the sediment and negative buoyancy particles mixed with the sediment. The vertical grain size distribution of the deposits was analysed to determine deposition variation with and without plastic. It is expected that the positively buoyant particles are trapped in the sediment by the currents flows and sink due to organic material adsorption. Finally, the experiments will explain how microplastic particles, including positively buoyant ones, are stored in natural sediment deposits.

Keywords: microplastic adsorption process, microplastic deposition in natural sediment, microplastic pollution in rivers, storages of positive buoyancy microplastic particles

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Authors: Maria Fatima Almeida, Rodrigo Calili, George Soares, João Krause, Myrthes Marcele Dos Santos, Anna Carolina Suzano E. Silva, Marcos Alexandre Da

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In Brazil, the building sector accounts for 1/6 of energy consumption and 50% of electricity consumption. A complex sector with several driving actors plays an essential role in the country's economy. Currently, the digitalization readiness in this sector is still low, mainly due to the high investment costs and the difficulty of estimating the benefits of digital technologies in buildings. Nevertheless, the potential contribution of digitalization for increasing energy efficiency in the building sector in Brazil has been pointed out as relevant in the political and sectoral contexts, both in the medium and long-term horizons. To contribute to the debate on the possible evolving trajectories of digitalization in the building sector in Brazil and to subsidize the formulation or revision of current public policies and managerial decisions, three future scenarios were created to anticipate the potential energy efficiency in the building sector in Brazil due to digitalization by 2050. This work aims to present these scenarios as a basis to foresight the potential energy efficiency in this sector, according to different digitalization paces - slow, moderate, or fast in the 2050 horizon. A methodological approach was proposed to create alternative prospective scenarios, combining the Global Business Network (GBN) and the Laboratory for Investigation in Prospective Strategy and Organisation (LIPSOR) methods. This approach consists of seven steps: (i) definition of the question to be foresighted and time horizon to be considered (2050); (ii) definition and classification of a set of key variables, using the prospective structural analysis; (iii) identification of the main actors with an active role in the digital and energy spheres; (iv) characterization of the current situation (2021) and identification of main uncertainties that were considered critical in the development of alternative future scenarios; (v) scanning possible futures using morphological analysis; (vi) selection and description of the most likely scenarios; (vii) foresighting the potential energy efficiency in each of the three scenarios, namely slow digitalization; moderate digitalization, and fast digitalization. Each scenario begins with a core logic and then encompasses potentially related elements, including potential energy efficiency. Then, the first scenario refers to digitalization at a slow pace, with induction by the government limited to public buildings. In the second scenario, digitalization is implemented at a moderate pace, induced by the government in public, commercial, and service buildings, through regulation integrating digitalization and energy efficiency mechanisms. Finally, in the third scenario, digitalization in the building sector is implemented at a fast pace in the country and is strongly induced by the government, but with broad participation of private investments and accelerated adoption of digital technologies. As a result of the slow pace of digitalization in the sector, the potential for energy efficiency stands at levels below 10% of the total of 161TWh by 2050. In the moderate digitalization scenario, the potential reaches 20 to 30% of the total 161TWh by 2050. Furthermore, in the rapid digitalization scenario, it will reach 30 to 40% of the total 161TWh by 2050.

Keywords: building digitalization, energy efficiency, scenario building, prospective structural analysis, morphological analysis

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Authors: Ahmed Boujdad

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‎ Morocco, a North African nation known for its rich culture and diverse landscapes, is facing evolving challenges related to cardiovascular health and behavioral well-being. Against this backdrop, the paper aims to spotlight the insights emerging from Moroccan research into the impacts of aerobic exercise on cardiovascular physiology and psychological outcomes. Presentations will encompass a range of topics, including exercise-induced adaptations in heart function, blood pressure management, and vascular health specific to the Moroccan population. A notable focus of the paper will be the examination of how aerobic exercise intertwines with Moroccan behavioral patterns and sociocultural factors. The research will delve into the links between regular exercise and its potential to alleviate stress, anxiety, and depression in the Moroccan context. This exploration extends to the role of exercise in bolstering the cultural fabric of Moroccan society, enhancing community engagement, and promoting a sense of well-being.

Keywords: event-related potential‎, executive function, physical activity, kinesiology

Procedia PDF Downloads 69

Authors: G. Balogh, I. A. Szabó, P.Z. Kovács

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Mechanical stress has a strong effect on the magnitude of the Barkhausen-noise in structural steels. Because the measurements are performed at the surface of the material, for a sample sheet, the full effect can be described by a biaxial stress field. The measured Barkhausen-noise is dependent on the orientation of the exciting magnetic field relative to the axis of the stress tensor. The sample inhomogenities including the residual stress also modifies the angular dependence of the measured Barkhausen-noise. We have developed a laboratory device with a cross like specimen for bi-axial bending. The measuring head allowed performing excitations in two orthogonal directions. We could excite the two directions independently or simultaneously with different amplitudes. The simultaneous excitation of the two coils could be performed in phase or with a 90 degree phase shift. In principle this allows to measure the Barkhausen-noise at an arbitrary direction without moving the head, or to measure the Barkhausen-noise induced by a rotating magnetic field if a linear superposition of the two fields can be assumed.

Keywords: Barkhausen-noise, bi-axial stress, stress measuring, stress dependency

Procedia PDF Downloads 279

Authors: Elkedrouci Lotfi, Diao Bo, Pang Sen, Li Yi

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Deterioration of reinforced concrete structures is a serious concern in the construction engineering, largely due to chloride induced corrosion of reinforcement. Chloride penetration is markedly influenced by one or several major factors at the same time such as cuing in combination with different crack widths which have spectacular effect on reinforced concrete structures. This research presents the results of an experimental investigation involving reinforced concrete beams with three different crack widths ranging from 0 to 0.2mm, curing temperatures of 20°C or 40°C and water-to-cement of 0.5. Chloride content profiles were determined under non-steady state diffusion at 20°C. Based on the obtained results, higher chloride content was obtained under condition of high curing temperature in combination with large crack more than 0.1mm and there are no significant differences between narrow crack width (less than 0.1 mm) and beams without crack (0mm).

Keywords: crack width, high curing temperature, rapid chloride migration, reinforced concrete beam

Procedia PDF Downloads 189

Authors: Gerd Wilsch, Tobias Guenther, Tobias Voelker

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In view of the ageing of vital infrastructure facilities, a reliable condition assessment of concrete structures is becoming of increasing interest for asset owners to plan timely and appropriate maintenance and repair interventions. For concrete structures, reinforcement corrosion induced by penetrating chlorides is the dominant deterioration mechanism affecting the serviceability and, eventually, structural performance. The determination of the quantitative chloride ingress is required not only to provide valuable information on the present condition of a structure, but the data obtained can also be used for the prediction of its future development and associated risks. At present, wet chemical analysis of ground concrete samples by a laboratory is the most common test procedure for the determination of the chloride content. As the chloride content is expressed by the mass of the binder, the analysis should involve determination of both the amount of binder and the amount of chloride contained in a concrete sample. This procedure is laborious, time-consuming, and costly. The chloride profile obtained is based on depth intervals of 10 mm. LIBS is an economically viable alternative providing chloride contents at depth intervals of 1 mm or less. It provides two-dimensional maps of quantitative element distributions and can locate spots of higher concentrations like in a crack. The results are correlated directly to the mass of the binder, and it can be applied on-site to deliver instantaneous results for the evaluation of the structure. Examples for the application of the method in the laboratory for the investigation of diffusion and migration of chlorides, sulfates, and alkalis are presented. An example for the visualization of the Li transport in concrete is also shown. These examples show the potential of the method for a fast, reliable, and automated two-dimensional investigation of transport processes. Due to the better spatial resolution, more accurate input parameters for model calculations are determined. By the simultaneous detection of elements such as carbon, chlorine, sodium, and potassium, the mutual influence of the different processes can be determined in only one measurement. Furthermore, the application of a mobile LIBS system in a parking garage is demonstrated. It uses a diode-pumped low energy laser (3 mJ, 1.5 ns, 100 Hz) and a compact NIR spectrometer. A portable scanner allows a two-dimensional quantitative element mapping. Results show the quantitative chloride analysis on wall and floor surfaces. To determine the 2-D distribution of harmful elements (Cl, C), concrete cores were drilled, split, and analyzed directly on-site. Results obtained were compared and verified with laboratory measurements. The results presented show that the LIBS method is a valuable addition to the standard procedures - the wet chemical analysis of ground concrete samples. Currently, work is underway to develop a technical code of practice for the application of the method for the determination of chloride concentration in concrete.

Keywords: chemical analysis, concrete, LIBS, spectroscopy

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Authors: Baby Tabassum, Priya Bajaj

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Cadmium is the second most hazardous heavy metal occurring in both elemental as well as compound forms. It is a highly toxic metal with a very high bio-concentration factor (BCF>100). WHO permitted groundwater cadmium concentration is 0.005 mg/L only, but reality is far away from this limit. A number of natural and anthropogenic industrial activities contribute to the spread of cadmium into the environment. The present study had been designated to find out the renal changes at functional level after cadmium intoxication and protection against these changes offered by Mentha piperata. For the purpose, albino rats were selected as the model organism. Cadmium significantly increases the serum level of serum proteins and nitrogenous wastes showing reduced filtration rate of kidneys. Pretreatment with Mentha piperata leaf extract causes significant retention of these levels to normalcy. These findings conclude that Cadmium exposure affects renal functioning but Mentha could prevent it, proving its nephro-protective potential against heavy metal toxicity.

Keywords: albino rat, cadmium, Mentha piperata, nephrotoxicity

Procedia PDF Downloads 377

Authors: Carmen E. Zapata, Juan Bautista, Olga Montoya, Claudia Moreno, Marisol Suarez, Alejandra Betancur, Duvan Nanclares, Natalia A. Cano

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This study aims to evaluate the diversity of microorganisms in filters PM2.5 and PM10; and determine the genotoxic and cytotoxic activity of the complex mixture present in PM2.5 filters used in the Aburrá Valley Air Quality Monitoring Network (Colombia). The research results indicate that particulate matter PM2.5 of different monitoring stations are bacteria; however, this study of detection of bacteria and their phylogenetic relationship is not complete evidence to connect the microorganisms with pathogenic or degrading activities of compounds present in the air. Additionally, it was demonstrated the damage induced by the particulate material in the cell membrane, lysosomal and endosomal membrane and in the mitochondrial metabolism; this damage was independent of the PM2.5 concentrations in almost all the cases.

Keywords: cytotoxic, genotoxic, microbiological analysis, PM10, PM2.5

Procedia PDF Downloads 329

Authors: Tomas Makaras, Julija Razumienė, Vidutė Gurevičienė, Gintarė Sauliutė, Milda Stankevičiūtė

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Stress responses represent animal’s natural reactions to various challenging conditions and could be used as a welfare indicator. Regardless of the wide use of glucose measurements in stress evaluation, there are some inconsistencies in its acceptance as a stress marker, especially when it comes to comparison with non-invasive cortisol measurements in the fish challenging stress. To meet the challenge and to test the reliability and applicability of glucose measurement in practice, in this study, different environmental/anthropogenic exposure scenarios were simulated to provoke chemical-induced stress in fish (14-days exposure to landfill leachate) followed by a 14-days stress recovery period and under the cumulative effect of leachate fish subsequently exposed to pathogenic oomycetes (Saprolegnia parasitica) to represent a possible infection in fish. It is endemic to all freshwater habitats worldwide and is partly responsible for the decline of natural freshwater fish populations. Brown trout (Salmo trutta fario) and sea trout (Salmo trutta trutta) juveniles were chosen because of a large amount of literature on physiological stress responses in these species was known. Glucose content in fish by applying invasive and non-invasive glucose measurement procedures in different test mediums such as fish blood, gill tissues and fish-holding water were analysed. The results indicated that the quantity of glucose released in the holding water of stressed fish increased considerably (approx. 3.5- to 8-fold) and remained substantially higher (approx. 2- to 4-fold) throughout the stress recovery period than the control level suggesting that fish did not recover from chemical-induced stress. The circulating levels of glucose in blood and gills decreased over time in fish exposed to different stressors. However, the gill glucose level in fish showed a decrease similar to the control levels measured at the same time points, which was found to be insignificant. The data analysis showed that concentrations of β-D glucose measured in gills of fish treated with S. parasitica differed significantly from the control recovery, but did not differ from the leachate recovery group showing that S. parasitica presence in water had no additive effects. In contrast, a positive correlation between blood and gills glucose were determined. Parallel trends in blood and water glucose changes suggest that water glucose measurement has much potency in predicting stress. This study demonstrated that measuring β-D-glucose in fish-holding water is not stressful as it involves no handling and manipulation of an organism and has critical technical advantages concerning current (invasive) methods, mainly using blood samples or specific tissues. The quantification of glucose could be essential for studies examining the stress physiology/aquaculture studies interested in the assessment or long-term monitoring of fish health.

Keywords: brown trout, landfill leachate, sea trout, pathogenic oomycetes, β-D-glucose

Procedia PDF Downloads 160