Search results for: dynamics of polymeric liquid

Authors: Zhao Wang, Hong Yan

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In this paper, a unified-gas kinetic scheme (UGKS) for the gas-particle flow is constructed. UGKS is a direct modeling method for both continuum and rarefied flow computations. The dynamics of particle and gas are described as rarefied and continuum flow, respectively. Therefore, we use the Bhatnagar-Gross-Krook (BGK) equation for the particle distribution function. For the gas phase, the gas kinetic scheme for Navier-Stokes equation is solved. The momentum transfer between gas and particle is achieved by the acceleration term added to the BGK equation. The new scheme is tested by a 2cm-in-thickness dense bed comprised of glass particles with 1.5mm in diameter, and reasonable agreement is achieved.

Keywords: gas-particle flow, unified gas-kinetic scheme, momentum transfer, shock-induced fluidization

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Authors: Daniil Chernov

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In the modern world, the number of conventional interstate wars is declining while the number of military interventions is rising. States no longer initiate conflicts by declaring war but actively intervene in existing military confrontations, often using a comparable number of coercive means. According to existing scholarly understanding, the decision to use force in international relations (in any form) is influenced by roughly the same set of factors: the dynamics of domestic political processes, national interests, international law, and ethical considerations. In the database on armed intervention to be presented in the report, the multifactor model of decision-making is developed. The database describes more than 200 different parameters for armed interventions between 1992 and 2022. The report will present the structure of the database, descriptive statistics, and its key advantages over other sources.

Keywords: conflict resolution, international relations, military intervention, database

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Authors: Miroslava Zelinkova, Marcela Ondova

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Fly ash (FA) thanks to the significant presence of SiO2 and Al2O3 as the main components is a potential raw material for geopolymers production. Mechanical activation is a method for improving FA reactivity and also the porosity of final mixture; those parameters can be analysed through sorption properties. They have direct impact on the durability of fly ash based geopolymer mortars. In the paper, effect of FA fineness on sorption properties of geopolymers based on sodium silicate, as well as relationship between fly ash fineness and apparent density, compressive and flexural strength of geopolymers are presented. The best results in the evaluated area reached the sample H1, which contents the highest portion of particle under 20μm (100% of GFA). The interdependence of individual tested properties was confirmed for geopolymer mixtures corresponding to those in the cement based mixtures: higher is portion of fine particles < 20μm, higher is strength, density and lower are sorption properties. The compressive strength as well as sorption parameters of the geopolymer can be reasonably controlled by grinding process and also ensured by the higher share of fine particle (to 20μm) in total mass of the material.

Keywords: alkali activation, geopolymers, fly ash, particle fineness

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Authors: Reza Moloudi, Steve Oh, Charles Chun Yang, Majid Ebrahimi Warkiani, May Win Naing

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Inertial microfluidics has emerged recently as a promising tool for high-throughput manipulation of particles and cells for a wide range of flow cytometric tasks including cell separation/filtration, cell counting, and mechanical phenotyping. Inertial focusing is profoundly reliant on the cross-sectional shape of the channel and its impacts not only on the shear field but also the wall-effect lift force near the wall region. Despite comprehensive experiments and numerical analysis of the lift forces for rectangular and non-rectangular microchannels (half-circular and triangular cross-section), which all possess planes of symmetry, less effort has been made on the 'flow field structure' of trapezoidal straight microchannels and its effects on inertial focusing. On the other hand, a rectilinear channel with trapezoidal cross-sections breaks down all planes of symmetry. In this study, particle focusing dynamics inside trapezoid straight microchannels was first studied systematically for a broad range of channel Re number (20 < Re < 800). The altered axial velocity profile and consequently new shear force arrangement led to a cross-laterally movement of equilibration toward the longer side wall when the rectangular straight channel was changed to a trapezoid; however, the main lateral focusing started to move backward toward the middle and the shorter side wall, depending on particle clogging ratio (K=a/Hmin, a is particle size), channel aspect ratio (AR=W/Hmin, W is channel width, and Hmin is smaller channel height), and slope of slanted wall, as the channel Reynolds number further increased (Re > 50). Increasing the channel aspect ratio (AR) from 2 to 4 and the slope of slanted wall up to Tan(α)≈0.4 (Tan(α)=(Hlonger-sidewall-Hshorter-sidewall)/W) enhanced the off-center lateral focusing position from the middle of channel cross-section, up to ~20 percent of the channel width. It was found that the focusing point was spoiled near the slanted wall due to the dissymmetry; it mainly focused near the bottom wall or fluctuated between the channel center and the bottom wall, depending on the slanted wall and Re (Re < 100, channel aspect ratio 4:1). Eventually, as a proof of principle, a trapezoidal straight microchannel along with a bifurcation was designed and utilized for continuous filtration of a broader range of particle clogging ratio (0.3 < K < 1) exiting through the longer wall outlet with ~99% efficiency (Re < 100) in comparison to the rectangular straight microchannels (W > H, 0.3 ≤ K < 0.5).

Keywords: cell/particle sorting, filtration, inertial microfluidics, straight microchannel, trapezoid

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Authors: V. Cesaroni, C. Girometta, A. Bernicchia, M. Brusoni, F. Corana, R. M. Baiguera, C. M. Cusaro, M. L. Guglielminetti, B. Mannucci, H. Kawagishi, C. Perini, A. M. Picco, P. Rossi, E. Salerni, E. Savino

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Fungi of the genus Hericium contain various compounds with antibacterial activity, cytotoxic effect on cancer cells and bioactive molecules. Some of the active metabolites stimulate the synthesis of the Nerve Growth Factor (NGF). Recently, the effect of dietary supplement based on Hericium erinaceus on recognition memory and on hippocampal mossy fiber-CA3 neurotransmission was published. The aim of this study was to investigate the presence of Hericium species on Italian territory in order to isolate the strains for further studies and applications. The first step was to collect Hericium sporophores in Tuscany: H. alpestre Pers., H. coralloides (Scop.) Pers. and H. erinaceus (Bull.) Pers. were the species present. The strains of H. alpestre (H.a.1), H. coralloides (H.c.1) and H. erinaceus (H.e.1 & H.e.2) have been isolated in pure culture and preserved in the collection of the University of Pavia (MicUNIPV). The DNA sequences obtained from the strains were compared to other sequences found in international databases. Therefore, it was possible to construct a phylogenetic tree that highlights the clear separation in clades of the sequences and the molecular identification of our strains with the species of Hericium considered. The second step was to cultivate indoor and outdoor H. erinaceus in order to obtain as many sporophores as possible for further chemical analysis. All the procedures for H. erinaceus cultivation have been followed. Among the available recipes for indoor H. erinaceus cultivation, it was used a substrate formulation contained 70% oak sawdust, 20% rice bran, 10% wheat straw, 1% CaCO3 and 1% sucrose. The bioactive compounds present in the mycelia and in the sporophores of H. erinaceus were chemically analyzed in collaboration with the Centro Grandi Strumenti of the University of Pavia using high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS). The materials to be analyzed were previously freeze-dried and then extracted with an alcoholic procedure. Preliminary chromatographic analysis revealed the presence of potentially bioactive and structurally different secondary metabolites such as polysaccharides, erinacins, ericenones, steroids and other terpenoids. Ericenones C and D (in sporophores) and erinacin A (in mycelium) have been identified by comparison with the respective standards. These molecules are known to have effects on the Central Nervous System (CNS) cells, which is the main objective of our studies. Thanks to the high sensitivity in the detection of bioactive compounds of H. erinaceus, it will be possible to use the To obtain lyophilized mycelium and the respective culture broth, 4 small pieces (about 5 mm2) of the respective H.e.1 or H.c.1 strains, taken from the margin of growing cultures (MEA), were inoculated into 1 liter of 2% ME (malt extract, Biokar Diagnostics). The static liquid cultures were kept at 24 °C in the dark chamber and fungi grew for one month. 10 replicates for each strain have been done. The method proposed as an analytical screening protocol to determine the optimal growth conditions of the fungus and to improve the production chain of H. erinaceus. These results encourage to carry out chemical analyzes also on H. alpestre and H. coralloides in order to evaluate the presence of bioactive compounds in these two species.

Keywords: Hericium species, Hercium erinaceus bioactive compounds, medicinal mushrooms, mushroom cultivation

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Authors: Sophio Kobauri, Tengiz Kantaria, Temur Kantaria, David Tugushi, Nina Kulikova, Ramaz Katsarava

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Polymeric disperse systems such as nanoparticles (NPs) are of high interest for numerous applications in contemporary medicine and nanobiotechnology to a considerable potential for treatment of many human diseases. The important technological advantages of NPs usage as drug carriers (nanocontainers) are their high stability, high carrier capacity, feasibility of encapsulation of both hydrophilic or hydrophobic substances, as well as a high variety of possible administration routes, including oral application and inhalation. NPs can also be designed to allow controlled (sustained) drug release from the matrix. These properties of NPs enable improvement of drug bioavailability and might allow drug dosage decrease. The targeted and controlled administration of drugs using NPs might also help to overcome drug resistance, which is one of the major obstacles in the control of epidemics. Various degradable and non-degradable polymers of both natural and synthetic origin have been used for NPs construction. One of the most promising for the design of NPs are amino acid-based biodegradable polymers (AABBPs) which can clear from the body after the fulfillment of their function. The AABBPs are composed of naturally occurring and non-toxic building blocks such as α-amino acids, fatty diols and dicarboxylic acids. The particles designed from these polymers are expected to have an improved bioavailability along with a high biocompatibility. The present work deals with a systematic study of the preparation of NPs by cost-effective polymer deposition/solvent displacement method using AABBPs. The influence of the nature and concentration of surfactants, concentration of organic phase (polymer solution), and the ratio organic phase/inorganic(water) phase, as well as of some other factors on the size of the fabricated NPs have been studied. It was established that depending on the used conditions the NPs size could be tuned within 40-330 nm. At the next step of this research was carried out an evaluation of biocompability and bioavailability of the synthesized NPs using a stable human cell culture line – A549. It was established that the obtained NPs are not only biocompatible but they stimulate the cell growth.

Keywords: amino acids, biodegradable polymers, bioavailability, nanoparticles

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Authors: Radha H. R., Krupakara P. V.

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Metal matrix composites are attracting today's manufacturers of many automobile parts so that they lost longer and their properties can be tailored according to the requirement. In this paper an attempt has been made to study the corrosion characteristics of Aluminium 6061 / quartz metal matrix composites in alkali medium like sodium hydroxide solutions. Metal matrix composites are heterogeneous mixtures of a matrix and reinforcement. In this work the matrix selected is Aluminium 6061 alloy which is commercially available and the reinforcement selected is quartz particulates of 50-80 micron size which is available in plenty in and around Bangalore district, India. Composites containing Aluminium 6061 with 2, 4 and 6 weight percent of quartz are manufactured by liquid melt metallurgy technique using vortex method. Corrosion tests like static weight loss and open circuit potential tests are conducted in different concentrated solutions of sodium hydroxide. To compare the results the matrix Aluminium 6061 is also casted in the same way. Specimens for the test are prepared according to ASTM standards. In all the tests the metal matrix composites showed better corrosion resistance than matrix alloy.

Keywords: aluminium 6061, corrosion, quartz, vortex

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Authors: Magdi M. E. Zumrawi, Khalid A. Eltayeb

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Chemical stabilization is a technique commonly used to improve the expansive soil properties. In this regard, an attempt has been made to evaluate the influence of Calcium Chloride (CaCl2) stabilizer on the engineering properties of expansive soil. A series of laboratory experiments including consistency limits, free swell, compaction, and shear strength tests were performed to investigate the effect of CaCl2 additive with various percentages 0%, 2%, 5%, 10% and 15% for improving expansive soil. The results obtained shows that the increase in the percentage of CaCl2 decreased the liquid limit and plasticity index leading to significant reduction in the free swell index. This, in turn, increased the maximum dry density and decreased the optimum moisture content which results in greater strength. The unconfined compressive strength of soil stabilized with 5% CaCl2 increased approximately by 50% as compared to virgin soil. It can be concluded that CaCl2 had shown promising influence on the strength and swelling properties of expansive soil, thereby giving an advantage in improving problematic expansive soil.

Keywords: calcium chloride, chemical stabilization, expansive soil, improving

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Authors: Esayas Geleta

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Within the last two decades in many sub-Saharan African countries, a large-scale acquisition (lease, concession, outright purchase) of extensive areas of farmland commonly labeled as ‘idle’ and ‘under-utilized’ has resulted in displacement and dispossession and dispossession without ‘compensation.’ This paper seeks to critically illustrate the processes and the consequences of the ‘land grabbing project’ in Ethiopia. Drawing on the theory of participatory development and empirical studies undertaken in Ethiopia, the paper elucidates the power dynamics that influence how and why dislocation and dispossession occur. The paper then demonstrates why the land-grabbing project, which was hugely supported by many international organizations, has largely failed in Ethiopia. Through a critical analysis of the process of ‘land grabbing’ in Ethiopia, the paper contributes to a more adequate and critical understanding of contemporary land deals and their social and environmental consequences.

Keywords: land grabbing, human rights, dispossession, resistance, governance

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Authors: Han Ding, Wang Xiaoliang, Duan Dengping

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During the process of airship design, the layout and the geometric shape of the hull and fins are crucial to the motion characteristics of the airship. In this paper, we obtained the quantification motion sensitivity of the airship to geometric parameters through turning circles and horizontal/vertical zigzag maneuvers by the parameterization of airship shape and building the dynamic model using Lagrangian approach and MATLAB Simulink program. In the dynamics simulation program, the affection of geometric parameters to the mass, center of gravity, moments of inertia, product of inertia, added mass and the aerodynamic forces and moments have been considered.

Keywords: airship, Lagrangian approach, turning circles, horizontal/vertical zigzag maneuvers

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Authors: Jacob Lewis Watts, Adam F. A. Pellegrini

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Prairies, grasslands, and forests cover an expansive portion of the world’s surface and contribute significantly to Earth’s carbon cycle. The largest driver of carbon dynamics in some of these ecosystems is fire. As the global climate changes, most fire-dominated ecosystems will experience increased fire frequency and intensity, leading to increased carbon flux into the atmosphere and soil nutrient depletion. The plant communities associated with different fire regimes are important for reassimilation of carbon lost during fire and soil recovery. More frequent fires promote conservative plant functional traits aboveground; however, belowground fine root traits are poorly explored and arguably more important drivers of ecosystem function as the primary interface between the soil and plant. The root economic spectrum (RES) hypothesis describes single-dimensional covariation between important fine-root traits along a range of plant strategies from acquisitive to conservative – parallel to the well-established leaf economic spectrum (LES). However, because of the paucity of root trait data, the complex nature of the rhizosphere, and the phylogenetic conservatism of root traits, it is unknown whether the RES hypothesis accurately describes plant nutrient and water acquisition strategies. This project utilizesplants grown in common garden conditions in the Cambridge University Botanic Garden and a meta-analysis of long-term fire manipulation experiments to examine the belowground physiological traits of fire-adapted and non-fire-adapted herbaceous species to 1) test the RES hypothesis and 2) describe the effect of fire regimes on fine root functional traits – which in turn affect carbon and nutrient cycling. A suite of morphological, chemical, and biological root traits (e.g. root diameter, specific root length, percent N, percent mycorrhizal colonization, etc.) of 50 herbaceous species were measuredand tested for phylogenetic conservatism and RES dimensionality. Fire-adapted and non-fire-adapted plants traits were compared using phylogenetic PCA techniques. Preliminary evidence suggests that phylogenetic conservatism may weaken the single-dimensionality of the RES, suggesting that there may not be a single way that plants optimize nutrient and water acquisition and storage in the complex rhizosphere; additionally, fire-adapted species are expected to be more conservative than non-fire-adapted species, which may be indicative of slower carbon cycling with increasing fire frequency and intensity.

Keywords: climate change, fire regimes, root economic spectrum, fine roots

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Authors: Sofia Lazareva, Artem Smolentsev

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Fluorescent photochromic materials collect strong interest due to their possible application in organic photonics such as optical logic systems, optical memory, visualizing sensors, as well as characterization of polymers and biological systems. In photochromic fluorescence switching systems the emission of fluorophore is modulated between ‘on’ and ‘off’ via the photoisomerization of photochromic moieties resulting in effective resonance energy transfer (FRET). In current work, we have studied both photochromic and fluorescent properties of several diarylethenes. It was found that coloured forms of these compounds are not fluorescent because of the efficient intramolecular energy transfer. Spectral and photochromic parameters of investigated substances have been measured in five solvents having different polarity. Quantum yields of photochromic transformation A↔B ΦA→B and ΦB→A as well as B isomer extinction coefficients were determined by kinetic method. It was found that the photocyclization reaction quantum yield of all compounds decreases with the increase of solvent polarity. In addition, the solvent polarity is revealed to affect fluorescence significantly. Increasing of the solvent dielectric constant was found to result in a strong shift of emission band position from 450 nm (nhexane) to 550 nm (DMSO and ethanol) for all three compounds. Moreover, the emission intensive in polar solvents becomes weak and hardly detectable in n-hexane. The only one exception in the described dependence is abnormally low fluorescence quantum yield in ethanol presumably caused by the loss of electron-donating properties of nitrogen atom due to the protonation. An effect of the protonation was also confirmed by the addition of concentrated HCl in solution resulting in a complete disappearance of the fluorescent band. Excited state dynamics were investigated by ultrafast optical spectroscopy methods. Kinetic curves of excited states absorption and fluorescence decays were measured. Lifetimes of transient states were calculated from the data measured. The mechanism of ring opening reaction was found to be polarity dependent. Comparative analysis of kinetics measured in acetonitrile and hexane reveals differences in relaxation dynamics after the laser pulse. The most important fact is the presence of two decay processes in acetonitrile, whereas only one is present in hexane. This fact supports an assumption made on the basis of steady-state preliminary experiments that in polar solvents occur stabilization of TICT state. Thus, results achieved prove the hypothesis of two channel mechanism of energy relaxation of compounds studied.

Keywords: diarylethenes, fluorescence switching, FRET, photochromism, TICT state

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Authors: Aymen Laadhari, Gábor Székely

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In this work, the hemodynamics in the sinuses of Valsalva after Transcatheter Aortic Valve Implantation is numerically examined. We focus on the physical results in the two-dimensional case. We use a finite element methodology based on a Lagrange multiplier technique that enables to couple the dynamics of blood flow and the leaflets’ movement. A massively parallel implementation of a monolithic and fully implicit solver allows more accuracy and significant computational savings. The elastic properties of the aortic valve are disregarded, and the numerical computations are performed under physiologically correct pressure loads. Computational results depict that blood flow may be subject to stagnation in the lower domain of the sinuses of Valsalva after Transcatheter Aortic Valve Implantation.

Keywords: hemodynamics, simulations, stagnation, valve

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Authors: S. P. Jordan, G. Christian, S. P. Jeffs

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Modern composite materials are increasingly being chosen in replacement of heavier metallic material systems within many engineering fields including aerospace and automotive industries. The increasing push towards satisfying environmental targets are fuelling new material technologies and manufacturing processes. This paper will introduce materials and manufacturing processes using metal matrix composites along with manufacturing processes optimized at Alvant Ltd., based in Basingstoke in the UK which offers modern, cost effective, selectively reinforced composites for light-weighting applications within engineering. An overview and introduction into modern optimized manufacturing methods capable of producing viable replacements for heavier metallic and lower temperature capable polymer composites are offered. A review of the capabilities and future applications of this viable material is discussed to highlight the potential involved in further optimization of old manufacturing techniques, to fully realize the potential to lightweight material using cost-effective methods.

Keywords: aluminium matrix composites, light-weighting, hybrid squeeze casting, strategically placed reinforcements

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Authors: Ellana Boada, Eric Santos-Clotas, Alba Cabrera-Codony, Maria Martin, Lluis Baneras, Frederic Gich

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Volatile methylsiloxanes (VMS) are a group of manmade silicone compounds widely used in household and industrial applications that end up on the biogas produced through the anaerobic digestion of organic matter in landfills and wastewater treatment plants. The presence of VMS during the biogas energy conversion can cause damage on the engines, reducing the efficiency of this renewable energy source. Non regenerative adsorption onto activated carbon is the most widely used technology to remove siloxanes from biogas, while new trends point out that biotechnology offers a low-cost and environmentally friendly alternative to conventional technologies. The first objective of this research was to enrich, isolate and identify bacterial species able to grow using siloxane molecules as a sole carbon source: anoxic wastewater sludge was used as initial inoculum in liquid anoxic enrichments, adding D4 (as representative siloxane compound) previously adsorbed on activated carbon. After several months of acclimatization, liquid enrichments were plated onto solid media containing D4 and thirty-four bacterial isolates were obtained. 16S rRNA gene sequencing allowed the identification of strains belonging to the following species: Ciceribacter lividus, Alicycliphilus denitrificans, Pseudomonas aeruginosa and Pseudomonas citronellolis which are described to be capable to degrade toxic volatile organic compounds. Kinetic assays with 8 representative strains revealed higher cell growth in the presence of D4 compared to the control. Our second objective was to characterize the community composition and diversity of the microbial community present in the enrichments and to elucidate whether the isolated strains were representative members of the community or not. DNA samples were extracted, the 16S rRNA gene was amplified (515F & 806R primer pair), and the microbiome analyzed from sequences obtained with a MiSeq PE250 platform. Results showed that the retrieved isolates only represented a minor fraction of the microorganisms present in the enrichment samples, which were represented by Alpha, Beta, and Gamma proteobacteria as dominant groups in the category class thus suggesting that other microbial species and/or consortia may be important for D4 biodegradation. These results highlight the need of additional protocols for the isolation of relevant D4 degraders. Currently, we are developing molecular tools targeting key genes involved in siloxane biodegradation to identify and quantify the capacity of the isolates to metabolize D4 in batch cultures supplied with a synthetic gas stream of air containing 60 mg m⁻³ of D4 together with other volatile organic compounds found in the biogas mixture (i.e. toluene, hexane and limonene). The isolates were used as inoculum in a biotrickling filter containing lava rocks and activated carbon to assess their capacity for siloxane removal. Preliminary results of biotrickling filter performance showed 35% of siloxane biodegradation in a contact time of 14 minutes, denoting that biological siloxane removal is a promising technology for biogas upgrading.

Keywords: bacterial cultivation, biogas upgrading, microbiome, siloxanes

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Authors: Simon Peter Wafula, Ziporah Nakabazzi Kitooke

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Graphene is a carbon allotrope made of a two-dimensional shape. This material has got a number of materials researchers’ interest due to its properties that are special compared to ordinary material. Graphene is thought to enhance a number of material properties in the manufacturing, energy, and construction industries. Many studies consider graphene to be a wonder material, just like plastic in the 21st century. This shows how much should be invested in graphene research. This review highlights the status of graphene extracted from various biomass sources together with their appropriate extraction techniques, including the pretreatment methods for a better product. The functional groups and structure of graphene extracted using several common methods of synthesis are in this paper as well. The review explores methods like chemical vapor deposition (CVD), hydrothermal, chemical exfoliation method, liquid exfoliation, and Hummers. Comparative analysis of the various extraction techniques gives an insight into each of their advantages, challenges, and potential scalability. The review also highlights the pretreatment process for biomass before carbonation for better quality of bio-graphene. The various graphene modes, as well as their applications, are in this study. Recommendations for future research for improving the efficiency and sustainability of bio-graphene are highlighted.

Keywords: exfoliation, nanomaterials, biochar, large-scale, two-dimension

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Authors: U. Amin, A. Talib, S. A. Qureshi, M. J. Hossain, G. Ahmad

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The choice evaluation between oil-immersed and dry-type transformers is often controlled by cost, location, and application. This paper compares the electrical performance of liquid- filled and dry-type transformers, which will assist the customer to choose the right and efficient ones for particular applications. An accurate assessment of the time-average flux density, electric field intensity and voltage distribution in an oil-insulated and a dry-type transformer have been computed and investigated. The detailed transformer modeling and analysis has been carried out to determine electrical parameter distributions. The models of oil-immersed and dry-type transformers are developed and solved by using the finite element method (FEM) to compare the electrical parameters. The effects of non-uniform and non-coherent voltage gradient, flux density and electric field distribution on the power losses and insulation properties of transformers are studied in detail. The results show that, for the same voltage and kilo-volt-ampere (kVA) rating, oil-immersed transformers have better insulation properties and less hysteresis losses than the dry-type.

Keywords: finite element method, flux density, transformer, voltage gradient

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Authors: Mohammad Hadi Jalali, Behrooz Shahriari, Mostafa Ghayour, Saeed Ziaei-Rad, Shahram Yousefi

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Most flexible rotors can be considered as beam-like structures. In many cases, rotors are modeled as one-dimensional bodies, made basically of beam-like shafts with rigid bodies attached to them. This approach is typical of rotor dynamics, both analytical and numerical, and several rotor dynamic codes, based on the finite element method, follow this trend. In this paper, a finite element model based on Timoshenko beam elements is utilized to analyze the lateral dynamic behavior of a certain rotor-bearing system in operating conditions.

Keywords: finite element method, Timoshenko beam elements, operational deflection shape, unbalance response

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Authors: Romany Wagih Farag Zaky

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The relationship between development and human rights has long been the subject of academic debate. To understand the dynamics between these two concepts, various principles are adopted, from the right to development to development-based human rights. Despite the initiatives taken, the relationship between development and human rights remains unclear. However, the overlap between these two views and the idea that efforts should be made in the field of human rights have increased in recent years. It is then evaluated whether the right to sustainable development is acceptable or not. The article concludes that the principles of sustainable development are directly or indirectly recognized in various human rights instruments, which is a good answer to the question posed above. This book therefore cites regional and international human rights agreements such as , as well as the jurisprudence and interpretative guidelines of human rights institutions, to prove this hypothesis.

Keywords: sustainable development, human rights, the right to development, the human rights-based approach to development, environmental rights, economic development, social sustainability human rights protection, human rights violations, workers’ rights, justice, security

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Authors: Nkongho Ayuketang Arreyndip, Ebobenow Joseph

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In this paper, to model a real life wind turbine, a probabilistic approach is proposed to model the dynamics of the blade elements of a small axial wind turbine under extreme stochastic wind speeds conditions. It was found that the power and the torque probability density functions even though decreases at these extreme wind speeds but are not infinite. Moreover, we also found that it is possible to stabilize the power coefficient (stabilizing the output power) above rated wind speeds by turning some control parameters. This method helps to explain the effect of turbulence on the quality and quantity of the harness power and aerodynamic torque.

Keywords: probability, probability density function, stochastic, turbulence

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Authors: Shipra Shukla, Gaurav Chaudhary, S. K. Tewari, Mahesh Pal, D. K. Upreti

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Cassia tora L. is widely distributed in tropical Asian countries, commonly known as sickle pod. Various parts of the plant are reported for their medicinal value due to presence of anthraquinones, phenolic compounds, emodin, β-sitosterol, and chrysophanol. Therefore a sensitive analytical procedure using UHPLC-ESI-MS/MS was developed and validated for simultaneous quantification of five phenolic compounds in leaf, stem and root extracts of Cassia tora. Rapid chromatographic separation of compounds was achieved on Acquity UHPLC BEH C18 column (50 mm×2.1 mm id, 1.7µm) column in 2.5 min. Quantification was carried out using negative electrospray ionization in multiple-reaction monitoring mode. The method was validated as per ICH guidelines and showed good linearity (r2 ≥ 0.9985) over the concentration range of 0.5-200 ng/mL. The intra- and inter-day precisions and accuracy were within RSDs ≤ 1.93% and ≤ 1.90%, respectively. The developed method was applied to investigate variation of five phenolic compounds in the three geographical collections. Results indicated significant variation among analyzed samples collected from different locations in India.

Keywords: Cassia tora, phenolic compounds, quantification, UHPLC-ESI-MS/MS

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Authors: Mezghiche Kamel

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We present solitary wave solutions for the perturbed nonlinear Schrodinger (PNLS) equation describing propagation of femtosecond light pulses through the fiber Bragg grating structure where the pulse dynamics is governed by the nonlinear-coupled mode (NLCM) equations. Using the multiple scale analysis, we reduce the NLCM equations into the perturbed nonlinear Schrodinger (PNLS) type equation. Unlike the reported solitary wave solutions of the PNLS equation, the novel ones can describe W shaped of solitons and their properties.

Keywords: fiber bragg grating, nonlinear-coupled mode equations, w shaped of solitons, PNLS

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Authors: Zhaoyang Liu

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It has been highly desired to develop a high-performance membrane for separating oil/water emulsions with the combined features of high water flux, high oil separation efficiency, and high mechanical stability. Here, we demonstrated a design for high-performance membranes constructed with ultra-long titanate nanofibers (over 30 µm in length)/cellulose microfibers. An integrated network membrane was achieved with these ultra-long nano/microfibers, contrast to the non-integrated membrane constructed with carbon nanotubes (5 µm in length)/cellulose microfibers. The morphological properties of the prepared membranes were characterized by A FEI Quanta 400 (Hillsboro, OR, United States) environmental scanning electron microscope (ESEM). The hydrophilicity, underwater oleophobicity and oil adhesion property of the membranes were examined using an advanced goniometer (Rame-hart model 500, Succasunna, NJ, USA). More specifically, the hydrophilicity of membranes was investigated by analyzing the spreading process of water into membranes. A filtration device (Nalgene 300-4050, Rochester, NY, USA) with an effective membrane area of 11.3 cm² was used for evaluating the separation properties of the fabricated membranes. The prepared oil-in-water emulsions were poured into the filtration device. The separation process was driven under vacuum with a constant pressure of 5 kPa. The filtrate was collected, and the oil content in water was detected by a Shimadzu total organic carbon (TOC) analyzer (Nakagyo-ku, Kyoto, Japan) to examine the separation efficiency. Water flux (J) of the membrane was calculated by measuring the time needed to collect some volume of permeate. This network membrane demonstrated good mechanical flexibility and robustness, which are critical for practical applications. This network membrane also showed high separation efficiency (99.9%) for oil/water emulsions with oil droplet size down to 3 µm, and meanwhile, has high water permeation flux (6.8 × 10³ L m⁻² h⁻¹ bar⁻¹) at low operation pressure. The high water flux is attributed to the interconnected scaffold-like structure throughout the whole membrane, while the high oil separation efficiency is attributed to the nanofiber-made nanoporous selective layer. Moreover, the economic materials and low-cost fabrication process of this membrane indicate its great potential for large-scale industrial applications.

Keywords: membrane, inorganic nanofibers, oil/water separation, emulsions

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Authors: Kumaresh Selvakumar, Man Young Kim

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Wet scrubbers have found widespread use in cleaning contaminated gas streams because of their ability to remove particulates and based on the applications of scrubbing of marine engine exhaust gases by spraying sea-water. In order to examine the flow characteristics inside the scrubber, the model is designated with flow properties of hot air and water sprayer. The flow dynamics of evaporation of hot air by the injection of water droplets is the key factor considered in this paper. The flow behavior inside the scrubber was investigated from the previous works and to sum up the evaporation rate with respect to the concentration of water droplets are predicted to bring out the competent modelling. The numerical analysis using CFD facilitates in understanding the problem better and empathies the behavior of the model over its entire operating envelope.

Keywords: concentration of water droplets, evaporation rate, scrubber, water sprayer

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Authors: Önder M. Özdem

Abstract:

Producing and circulating films of professional standards have become technically easier with the development and widespread use of digital recording and distribution technologies. Additionally, film festivals on common platforms have rapidly increased in numbers and diversity. On the one hand, no-charge applications result in excessive submissions; thus, it complicates the evaluation and selection process. On the other hand, festival’s high submission fees may make the distribution of films with a limited budget very difficult. Inspired by the author’s engagement with the film industry as both a pre-jury member of an international film festival and an applicant to many festivals, this study discusses the causes and consequences of the increasing commercialization of film festivals. The author’s double identity, both as a jury and an applicant, provides a comparative perspective through which one can unfold the different dimensions and dynamics in the film production and distribution processes.

Keywords: commercialization, film distribution, film festivals, film production

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Authors: Clara Voyvodic

Abstract:

Transitions from conflict to peace are by no means smooth nor linear, particularly from the perspective of those living through them. Over the last few decades, the changing focus in peacebuilding studies has come to appreciate the everyday experience of communities and how that provides a lens through which the relative success or efficacy of these transitions can be understood. In particular, the demobilization of a significant conflict actor is not without consequences, not just for the macro-view of state stabilization and peace, but for the communities who find themselves without a clear authority of territorial control. In Colombia, the demobilization and disarmament of the FARC guerilla group provided a brief respite to the conflict and a major political win for President Manuel Santos. However, this victory has proven short-lived. Drawing from extensive field research in Colombia within the last year, including interviews with local communities and actors operating in these regions, field observations, and other primary resources, this paper examines the post-accord transitions in Colombia and the everyday security experiences of local communities in regions formerly controlled by the FARC. In order to do so, the research focused on a semi-ethnographic approach in the northern region of the department of Antioquia and the coastal area of the border department of Nariño that documented how individuals within these marginalized communities have come to understand and negotiate their security in the years following the accord and the demobilization of the FARC. This presentation will argue that the removal of the FARC as an informal governance actor opened a space for multiple actors to attempt to control the same territory, including the state. This shift has had a clear impact on the everyday security experiences of the local communities. With an exploration of the dynamics of local governance and its impact on lived security experiences, this research seeks to demonstrate how distinct patterns of armed group behavior are emerging not only from a vacuum of control left by the FARC but from an increase in state presence that nonetheless remains inconsistent and unpersuasive as a monopoly of force in the region. The increased multiplicity of actors, particularly the state, has meant that the normal (informal) rules for communities to navigate these territories are no longer in play as the identities, actions, and intentions of different competing groups have become frustratingly opaque. This research provides a prescient analysis on how the shifting dynamics of territorial control in a post-peace accord landscape produce uncertain realities that affect the daily lives of the local communities and endanger the long-term prospect of human-centered security.

Keywords: armed actors, conflict transitions, informal governance, post-accord, security experiences

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Authors: Moustafa Osman

Abstract:

Modeling of air pollutants from the accidental release is performed for quantifying the impact of industrial facilities into the ambient air. The mathematical methods are requiring for the prediction of the accidental scenario in probability of failure-safe mode and analysis consequences to quantify the environmental damage upon human health. The initial statement of mitigation plan is supporting implementation during production and maintenance periods. In a number of mathematical methods, the flow rate at which gaseous and liquid pollutants might be accidentally released is determined from various types in term of point, line and area sources. These emissions are integrated meteorological conditions in simplified stability parameters to compare dispersion coefficients from non-continuous air pollution plumes. The differences are reflected in concentrations levels and greenhouse effect to transport the parcel load in both urban and rural areas. This research reveals that the elevation effect nearby buildings with other structure is higher 5 times more than open terrains. These results are agreed with Sutton suggestion for dispersion coefficients in different stability classes.

Keywords: air pollutants, dispersion modeling, GIS, health effect, urban planning

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Authors: A. Morsli, A. Tlemçani, N. Ould Cherchali, M. S. Boucherit

Abstract:

This article presents two methods for the compensation of harmonics generated by a nonlinear load. The first is the classic method P-Q. The second is the controller by modern method of artificial intelligence specifically fuzzy logic. Both methods are applied to an Active Power Filter shunt (APFs) based on a three-phase voltage converter at five levels NPC topology. In calculating the harmonic currents of reference, we use the algorithm P-Q and pulse generation, we use the intersective PWM. For flexibility and dynamics, we use fuzzy logic. The results give us clear that the rate of Harmonic Distortion issued by fuzzy logic is better than P-Q.

Keywords: fuzzy logic controller, P-Q method, pulse width modulation (PWM), shunt active power filter (sAPF), total harmonic distortion (THD)

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Authors: M. H. Alhajeri, Hamad M. Alhajeri, A. H. Alenezi

Abstract:

This paper reports a Computational Fluid Dynamics (CFD) investigation for a high-temperature high-pressure filtration (ceramic candle filter). However, parallel flow to the filter is considered in this study. Different face (filtration) velocities are examined using the CFD code, FLUENT. Different sizes of particles are tracked through the domain to find the height at which the particles will impinge on the filter surface. Furthermore, particle distribution around the filter (or filter cake) is studied to design efficient cleaning mechanisms. Gravity effect to the particles with various inlet velocities and pressure drop are both considered. In the CFD study, it is found that the gravity influence should not be ignored if the particle sizes exceed 1 micron.

Keywords: fluid flow, CFD, filtration, HTHP

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Authors: Mohamed Hashelaf, Ahmed Al-Osdody

Abstract:

In this paper, we focused our efforts on one of the vaguest subjects in astrophysics that is the formation and evolution of the universe until the arrival of humans. Through an in-depth exploration of the origins of the universe, understanding what has happened since the Big Bang until now and checking the history of creation, we can answer questions about the future of life, the possibility of its existence elsewhere in the universe and to be able to understand how we came, what our role in the circle of life is and what the future of our development will be. Here is where we used systematic steps that allowed us first and foremost to identify the reason behind the big bang itself that formed a large cloud of cosmic dust. Then after a period of time from the expansion of the universe and its coolness, the initial molecules of gases from the cosmic cloud began to condense, forming a very dense field of gravity that after millions of years led to the formation of stars, galaxies, even earth and the else planets. Finally, it became clear before us that after the earth has formed, the existence of liquid water made it possible for life to form, starting from the bacteria all the way until the appearance of the humans that we know today. But it does not stop here. If we look and contemplate in ourselves as humans, we will understand that the universe is inside us and that’s what makes us exceptional. All of this means that just as life on earth was created, it could have been on other planets as well. It also means that we are the universe’s key to understand itself.

Keywords: Big Bang, cosmic dust, primary elements, universe

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