Search results for: heat stability and PH range

Authors: Qian Yi Ooi

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At present, airfoil parameters are still designed and optimized according to the scale of conventional aircraft, and there are still some slight deviations in terms of scale differences. However, insufficient parameters or poor surface mesh quality is likely to occur if these small deviations are embedded in a future civil aircraft with a size that is quite different from conventional aircraft, such as a blended-wing-body (BWB) aircraft with future potential, resulting in large deviations in geometric similarity in computational fluid dynamics (CFD) simulations. To avoid this situation, the study on the CFD calculation on the geometric similarity of airfoil parameters and the quality of the surface mesh is conducted to obtain the ability of different parameterization methods applied on different airfoil scales. The research objects are three airfoil scales, including the wing root and wingtip of conventional civil aircraft and the wing root of the giant hybrid wing, used by three parameterization methods to compare the calculation differences between different sizes of airfoils. In this study, the constants including NACA 0012, a Reynolds number of 10 million, an angle of attack of zero, a C-grid for meshing, and the k-epsilon (k-ε) turbulence model are used. The experimental variables include three airfoil parameterization methods: point cloud method, B-spline curve method, and class function/shape function transformation (CST) method. The airfoil dimensions are set to 3.98 meters, 17.67 meters, and 48 meters, respectively. In addition, this study also uses different numbers of edge meshing and the same bias factor in the CFD simulation. Studies have shown that with the change of airfoil scales, different parameterization methods, the number of control points, and the meshing number of divisions should be used to improve the accuracy of the aerodynamic performance of the wing. When the airfoil ratio increases, the most basic point cloud parameterization method will require more and larger data to support the accuracy of the airfoil’s aerodynamic performance, which will face the severe test of insufficient computer capacity. On the other hand, when using the B-spline curve method, average number of control points and meshing number of divisions should be set appropriately to obtain higher accuracy; however, the quantitative balance cannot be directly defined, but the decisions should be made repeatedly by adding and subtracting. Lastly, when using the CST method, it is found that limited control points are enough to accurately parameterize the larger-sized wing; a higher degree of accuracy and stability can be obtained by using a lower-performance computer.

Keywords: airfoil, computational fluid dynamics, geometric similarity, surface mesh quality

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Authors: Liliane Ventura, Mauro Masili

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Ultraviolet (UV) protection is critical for sunglasses, and mydriasis, as well as miosis, are relevant parameters to consider. The literature reports that for sunglasses, ultraviolet protection is critical because sunglasses can cause the opposite effect if the lenses do not provide adequate UV protection due to the greater dilation of the pupil when wearing sunglasses. However, the scientific literature does not properly quantify to support this rationale. The reasoning may be misleading by ignoring not only the inherent absorption of UV by the sunglass lens materials but also by ignoring the absorption of the anterior structures of the eye, i.e., the cornea and aqueous humor. Therefore, we estimate the pupil diameter and calculate the solar ultraviolet influx through the pupil of the human eye for two situations of an individual wearing and not wearing sunglasses. We quantify the dilation of the pupil as a function of the luminance of the surrounding. Therefore, we calculate the influx of solar UV through the pupil of the eye for two situations for an individual wearing sunglass and for the eyes free of shade. A typical boundary condition for the calculation is an individual in an upright position wearing sunglasses, staring at the horizon as if the sun is in the zenith. The calculation was done for the latitude of the geographic center of the state of São Paulo (-22º04'11.8'' S) from sunrise to sunset. A model from the literature is used for determining the sky luminance. The initial approach is to obtain pupil diameter as a function of luminance. Therefore, as a preliminary result, we calculate the pupil diameter as a function of the time of day, as the sun moves, for a particular day of the year. The working range for luminance is daylight (10⁻⁴ – 10⁵ cd/m²). We are able to show how the pupil adjusts to brightness change (~2 - ~7.8 mm). At noon, with the sun higher, the direct incidence of light on the pupil is lower if compared to mid-morning or mid-afternoon, when the sun strikes more directly into the eye. Thus, the pupil is larger at midday. As expected, the two situations have opposite behaviors since higher luminance implies a smaller pupil. With these results, we can progress in the short term to obtain the transmittance spectra of sunglasses samples and quantify how light attenuation provided by the spectacles affects pupil diameter.

Keywords: sunglasses, UV protection, pupil diameter, solar irradiance, luminance

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Authors: Merlin Simo Tagne, Romain Rémond

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This study provides the sorption isotherm, its hysteresis and their mass transfer properties of four Central Africa Tropical woods largely used for building construction: frake, lotofa, sapelle and ayous. Characterization of these three species in particular and Central Africa tropical woods, in general, was necessary to develop conservation and treatment of wood after first transformation using the drying. Isotherms were performed using a dynamic vapor sorption apparatus (Surface Measurement Systems) at 20 and 40°C. The mass diffusivity was determined in steady state using a specific vapometer. Permeability was determined using a specialized device developed to measure over a wide range of permeability values. Permeability and mass transfer properties are determined in the tangential direction with a ‘false’ quartersawn cutting (sapelle and lotofa) and in the radial direction with a ‘false’ flatsawn cutting (ayous and frake). The sample of sapelle, ayous and frake are heartwood when lotofa contains as well as heartwood than sapwood. Results obtained showed that the temperature effect on sorption behavior was low than relative humidity effect. We also observed a low difference between the sorption behavior of our woods and hysteresis of sorption decreases when the temperature increases. Hailwood-Horrobin model’s predicts the isotherms of adsorption and desorption of ours woods and parameters of this model are proposed. Results on the characterization of mass transfer properties showed that, in the steady state, mass diffusivity decreases exponentially when basal density increases. In the phase of desorption, mass diffusivity is great than in the phase of adsorption. The permeability of ours woods are greater than Australian hardwoods but lower than temperate woods. It is difficult to define a relationship between permeability and mass diffusivity.

Keywords: tropical woods, sorption isotherm, diffusion coefficient, gas permeability, Central Africa

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Authors: Hardisiswo Soedjana, Inne Caroline

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Deep dermal or full thickness burns are inevitably lead to post-burn contractures. These contractures remain to be one of the most concerning late complications of burn injuries. Surgical management includes releasing the contracture followed by resurfacing the defect accompanied by post-operative rehabilitation. Optimal treatment of post-burn contractures depends on the characteristics of the contractures. This study is aimed to describe clinical characteristics, problems, and management of post-burn contractures in adults and children. A retrospective analysis was conducted from medical records of patients suffered from contractures after burn injuries admitted to Hasan Sadikin general hospital between January 2016 and January 2018. A total of 50 patients with post burn contractures were included in the study. There were 17 adults and 33 children. Most patients were male, whose age range within 15-59 years old and 5-9 years old. Educational background was mostly senior high school among adults, while there was only one third of children who have entered school. Etiology of burns was predominantly flame in adults (82.3%); whereas flame and scald were the leading cause of burn injury in children (11%). Based on anatomical regions, hands were the most common affected both in adults (35.2%) and children (48.5%). Contractures were identified in 6-12 months since the initial burns. Most post-burn hand contractures were resurfaced with full-thickness skin graft (FTSG) both in adults and children. There were 11 patients who presented with recurrent contracture after previous history of contracture release. Post-operative rehabilitation was conducted for all patients; however, it is important to highlight that it is still challenging to control splinting and exercise when patients are discharged and especially the compliance in children. In order to improve quality of life in patients with history of deep burn injuries, prevention of contractures should begin right after acute care has been established. Education for the importance of splinting and exercise should be administered as comprehensible as possible for adult patients and parents of pediatric patients.

Keywords: burn, contracture, education, exercise, splinting

Procedia PDF Downloads 130

Authors: Paula Lopez-Arce, Hector Altamirano, Dimitrios Rovas, James Berry, Bryan Hindle, Steven Hodgson

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Efficient mould remediation and accurate moisture diagnostics leading to condensation and mould growth in dwellings are largely untapped. Number of factors are contributing to the rising trend of excessive moisture in homes mainly linked with modern living, increased levels of occupation and rising fuel costs, as well as making homes more energy efficient. Environmental monitoring by means of data collection though loggers sensors and survey forms has been performed in a range of buildings from different UK regions. Air and surface temperature and relative humidity values of residential areas affected by condensation and/or mould issues were recorded. Additional measurements were taken through different trials changing type, location, and position of loggers. In some instances, IR thermal images and ventilation rates have also been acquired. Results have been interpreted together with environmental key parameters by processing and connecting data from loggers and survey questionnaires, both in buildings with and without moisture issues. Monitoring exercises carried out during Winter and Spring time show the importance of developing and following accurate protocols for guidance to obtain consistent, repeatable and comparable results and to improve the performance of environmental monitoring. A model and a protocol are being developed to build a diagnostic tool with the goal of performing a simple but precise residential atmospheric moisture diagnostics to distinguish the cause entailing condensation and mould generation, i.e., ventilation, insulation or heating systems issue. This research shows the relevance of monitoring and processing environmental data to assign moisture risk levels and determine the origin of condensation or mould when dealing with a building atmospheric moisture excess.

Keywords: environmental monitoring, atmospheric moisture, protocols, mould

Procedia PDF Downloads 139

Authors: Mathew Wakefield, Matthew Mitchell, Lisa Wise, Christopher McCarthy

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The properties of memory representations in artificial neural networks have cognitive implications. Distributed representations that encode instances as a pattern of activity across layers of nodes afford memory compression and enforce the selection of a single point in instance space. These encoding schemes also appear to distort the representational space, as well as trading off the ability to validate that input information is within the bounds of past experience. In contrast, a localist representation which encodes some meaningful information into individual nodes in a network layer affords less memory compression while retaining the integrity of the representational space. This allows the validity of an input to be determined. The validity (or familiarity) of input along with the capacity of localist representation for multiple instance selections affords a memory sampling approach that dynamically balances the bias-variance trade-off. When the input is familiar, bias may be high by referring only to the most similar instances in memory. When the input is less familiar, variance can be increased by referring to more instances that capture a broader range of features. Using this approach in a localist instance memory network, an experiment demonstrates a relationship between representational conflict, generalization performance, and memorization demand. Relatively small sampling ranges produce the best performance on a classic machine learning dataset of visual objects. Combining memory validity with conflict detection produces a reliable confidence judgement that can separate responses with high and low error rates. Confidence can also be used to signal the need for supervisory input. Using this judgement, the need for supervised learning as well as memory encoding can be substantially reduced with only a trivial detriment to classification performance.

Keywords: artificial neural networks, representation, memory, conflict monitoring, confidence

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Authors: Naveed Ali

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Under the construct of the ‘traditional family’ set-up (male and female parent) in the United Kingdom, the absence of a male parental figure remains a critical factor associated with an elevated risk of criminal behavior among youths. Empirical evidence suggests that father absence significantly correlates with increased rates of juvenile delinquency and criminality. For instance, data reveals that approximately 63% of young offenders in the United Kingdom originate from single-parent households, predominantly those without a father. Moreover, research displays that boys from father-absent homes are three times more likely to exhibit antisocial behavior compared to their peers from two-parent families. This absence can negatively impact educational attainment, with children from fatherless homes being twice as likely to leave school prematurely, thereby increasing their vulnerability to peer influence and gang affiliation- key pathways into criminal activities. Both legal frameworks and social policies in the United Kingdom acknowledge the pivotal role of family stability in crime prevention. Initiatives including parenting support programs, community-based interventions, and targeted youth services seek to address the challenges faced by single-parent families and mitigate the criminogenic effects of father absence. Despite these efforts, persistent challenges remain, including the need to address the broader socioeconomic determinants of family instability and to refine legal strategies that effectively address the root causes of youth offending linked to the absence of a male parental figure. A nuanced understanding of these dynamics is essential for developing more effective legal and social interventions aimed at reducing juvenile delinquency and supporting at-risk populations within the United Kingdom. This paper will highlight the significant impact of the absence of a male parental figure on youth crime rates in the United Kingdom, underlining the need for enhanced legal and social responses. By examining the interplay between family structure and juvenile offending, the paper will underline the importance of developing more comprehensive interventions that address both familial factors and the wider socioeconomic context. The findings aim to guide policymakers and practitioners in creating more effective strategies to reduce youth crime, ultimately strengthening support systems for vulnerable families and mitigating the adverse effects of father absence on young individuals.

Keywords: criminality, family law, legal framework, the united kingdom perspective

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Authors: Uzaira Rafique, Kousar Parveen

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The discharge volume and composition of Textile effluents gains scientific concern due to its hazards and biotoxcity of azo dyes. Azo dyes are non-biodegradable due to its complex molecular structure and recalcitrant nature. Serious attempts have been made to synthesize and develop new materials to combat the environmental problems. The present study is designed for removal of a range of azo dyes (Methyl orange, Congo red and Basic fuchsine) from synthetic aqueous solutions and real textile effluents. For this purpose, Metal (cobalt) doped alumina hybrids are synthesized and applied as adsorbents in the batch experiment. Two different aluminium precursor (aluminium nitrate and spent aluminium foil) and glucose are mixed following sol gel method to get hybrids. The synthesized materials are characterized for surface and bulk properties using FTIR, SEM-EDX and XRD techniques. The characterization of materials under FTIR revealed that –OH (3487-3504 cm-1), C-H (2935-2985 cm-1), Al-O (~ 800 cm-1), Al-O-C (~1380 cm-1), Al-O-Al (659-669 cm-1) groups participates in the binding of dyes onto the surface of hybrids. Amorphous shaped particles and elemental composition of carbon (23%-44%), aluminium (29%-395%), and oxygen (11%-20%) is demonstrated in SEM-EDX micrograph. Time-dependent batch-experiments under identical experimental parameters showed 74% congo red, 68% methyl orange and 85% maximum removal of basic fuchsine onto the surface of cobalt doped alumina hybrids probably through the ion-exchange mechanism. The experimental data when treated with adsorption models is found to have good agreement with pseudo second order kinetic and freundlich isotherm for adsorption process. The present study concludes the successful synthesis of novel and efficient cobalt doped alumina hybrids providing environmental friendly and economical alternative to the commercial adsorbents for the treatment of industrial effluents.

Keywords: alumina hybrid, adsorption, dopant, isotherm, kinetic

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Authors: Eric Awich Ochen

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The end of the conflict in Northern Uganda in 2006 brought about an opportunity for the youth to return to their original home and contribute to the peace building and development process of their communities. Post-conflict is used here to refer to the post-armed conflict situation and activities of rebels of Joseph Kony in northern Uganda. While the rebels remain very much active in the Sudan and Central African Republic, in Uganda the last confrontations occurred around 2006 or earlier, and communities have returned to their homes and began the process of rebuilding their lives. It is argued that socio-economic reconstruction is at the heart of peacebuilding and sustenance of positive peace in the aftermath of conflict, as it has a bearing on post-conflict stability and good governance. We recognize that several post-conflict interventions within Northern Uganda have targeted women and children with a strong emphasis on family socio-economic empowerment and capacity building, including access to micro finance. The aim of this study was to examine the participation of the youth in post-conflict peace building and development in Northern Uganda by assessing the breadth and width of their engagement and the stages of programming cycle that they are involved in, interrogating the space for participation and how they are facilitating or constraining participation. It was further aimed at examining the various dimensions of participation at play in Northern Uganda and where this fits within the conceptual debates on peace building and development in the region. Supporting young people emerging out of protracted conflict to re-establish meaningful socio-economic engagements and livelihoods is fundamental to their participation in the affairs of the community. The study suggests that in the post-conflict development context of Northern Uganda, participation has rarely been disaggregated or differentiated by sectors or groups. Where some disaggregation occurs, then the main emphasis has always been on either women or children. It appears therefore that little meaningful space has thus been created for young people to engage and participate in peace building initiatives within the region. In other cases where some space is created for youth participation, this has been in pre-conceived programs or interventions conceived by the development organizations with the youth or young people only invited to participate at particular stages of the project implementation cycle. Still within the implementation of the intervention, the extent to which young people participate is bounded, with little power to influence the course of the interventions or make major decisions. It is thus visible that even here young people mainly validate and legitimize what are predetermined processes only act as pawns in the major chess games played by development actors (dominant peace building partners). This paper, therefore, concludes that the engagement of the youth in post-conflict peace building has been quite problematic and tokenistic and has not given the adequate youth space within which they could ably participate and express themselves in the ensuing interventions.

Keywords: youth, conflict, peace building, participation

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Authors: Bolysbek Utelbayev, Tasmagambetova Aigerim, Toktasyn Raila, Markayev Yergali, Myrzakhanov Maxat

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Intensive development of secondary processes of destructive processing of crude oil has led to the occurrence of oil refining factories resources of C2-C4 hydrocarbons. Except for oil gases also contain basically C2-C4 hydrocarbon gases where some of the amounts are burned. All these data has induced interest to the study of producing alkylate from hydrocarbons С2-С4 which being as components of motor fuels. The purpose of this work was studying transformation propane-propene, butane-butene fractions at the presence of the ruthenium-chromic support catalyst whereas the carrier is served pillar - structural montmorillonite containing in native bentonite clay. In this work is considered condition and structure of the bentonite clay from the South-Kazakhstan area of the Republic Kazakhstan. For preparation rhodium support catalyst (0,5-1,0 mass. % Rh) was used chloride of rhodium-RhCl3∙3H2O, as a carrier was used modified bentonite clay. For modifying natural clay to pillar structural form were used polyhydroxy complexes of chromium. To aqueous solution of chloride chromium gradually flowed the solution of sodium hydroxide at gradual hashing up to pH~3-4. The concentration of chloride chromium was paid off proceeding from calculation 5-30 mmole Cr3+ per gram clay. Suspension bentonite (~1,0 mass. %) received by intensive washing it in water during 4 h, pH-water extract of clay makes -8-9. The acidity of environment supervised by means of digital pH meter OP-208/1. In order to prevent coagulation of a solution polyhydroxy complexes of chromium, it was slowly added to a suspension of clay. "Reserve of basicity" Cr3+:/OH-allowing to prevent coagulation chloride of rhodium made 1/3. After endurance processed suspensions of clay during 24 h, a deposit was washed by water and condensed. The sample, after separate from a liquid phase, dried at first at the room temperature, and then at 110°C (2h) with the subsequent rise the temperature up to 180°C (4h). After cooling the firm mass was pounded to a powder, it was shifted infractions with the certain sizes of particles. Fractions of particles modifying clay in the further were impregnated with an aqueous solution with rhodium-RhCl3∙3H2O (0,5-1,0 mаss % Rh ). Obtained pillar structural bentonite approaches heat resistance and its porous structure above the 773K. Pillar structural bentonite was used for preparation 1.0% Ru/Carrier (modifying bentonite) support catalysts where is realised alkylation of C2-C4 hydrocarbons. The process of alkylation is carried out at a partial pressure of hydrogen 0.5-1.0MPa. Outcome 2.2.4 three methyl pentane and 2.2.3 trimethylpentane achieved 40%. At alkylation butane-butene mixture outcome of the isooctane is achieved 60%. In this condition of studying the ethene is not undergoing to alkylation.

Keywords: alkylation, butene, pillar structure, ruthenium catalyst

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Authors: Shiv Jyoti Pandey, Shveta Puri, G. M. Bhat, Neha Raina

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The Jammu and Kashmir (J&K) region of Northwest Himalaya has a long history of earthquake activity which falls within Seismic Zones IV and V. To know the crustal structure beneath this region, we utilized teleseismic receiver function method. This paper presents the results of the analyses of the teleseismic earthquake waves recorded by 10 seismic observatories installed in the vicinity of major thrusts and faults. The teleseismic waves at epicentral distance between 30o and 90o with moment magnitudes greater than or equal to 5.5 that contains large amount of information about the crust and upper mantle structure directly beneath a receiver has been used. The receiver function (RF) technique has been widely applied to investigate crustal structures using P-to-S converted (Ps) phases from velocity discontinuities. The arrival time of the Ps, PpPs and PpSs+ PsPs converted and reverberated phases from the Moho can be combined to constrain the mean crustal thickness and Vp/Vs ratio. Over 500 receiver functions from 10 broadband stations located in the Jammu & Kashmir region of Northwest Himalaya were analyzed. With the help of H-K stacking method, we determined the crustal thickness (H) and average crustal Vp/Vs ratio (K) in this region. We also used Neighbourhood algorithm technique to verify our results. The receiver function results for these stations show that the crustal thickness under Jammu & Kashmir ranges from 45.0 to 53.6 km with an average value of 50.01 km. The Vp/Vs ratio varies from 1.63 to 1.99 with an average value of 1.784 which corresponds to an average Poisson’s ratio of 0.266 with a range from 0.198 to 0.331. High Poisson’s ratios under some stations may be related to partial melting in the crust near the uppermost mantle. The crustal structure model developed from this study can be used to refine the velocity model used in the precise epicenter location in the region, thereby increasing the knowledge to understand current seismicity in the region.

Keywords: H-K stacking, Poisson’s ratios, receiver function, teleseismic

Procedia PDF Downloads 248

Authors: Ravi Prakash Maurya, Munaswamyreddygari Sreedhar

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The present studies on ecological engineering through soil amendments in cabbage crops for insect pests regulation were conducted at G. B. Pant University of Agriculture and Technology, Pantnagar, Udham Singh Nagar, Uttarakhand, India. Ten treatments viz., Farm Yard Manure (FYM), Neem cake (NC), Vermicompost (VC), Poultry manure (PM), PM+FYM, NC+VC, NC+PM, VC+FYM, Urea+ SSP+MOP (Standard Check) and Untreated Check were evaluated to study the effect of these amendments on the population of insect pests, natural enemies and the microbial community of the rhizosphere in the cabbage crop ecosystem. The results revealed that most of the cabbage pests, viz., aphids, head borer, gram pod borer, and armyworm, were more prevalent in FYM, followed by PM and NC-treated plots. The best cost-benefit ratio was found in PM + FYM treatment, which was 1: 3.62, while the lowest, 1: 0.97, was found in the VC plot. The population of natural enemies like spiders, coccinellids, syrphids, and other hymenopterans and dipterans was also found to be prominent in organic plots, namely FYM, followed by VC and PM plots. Diversity studies on organic manure-treated plots were also carried out, which revealed a total of nine insect orders (Hymenoptera, Hemiptera, Lepidoptera, Coleoptera, Neuroptera, Diptera, Orthoptera, Dermaptera, Thysanoptera, and one arthropodan class, Arachnida) in different treatments. The Simpson Diversity Index was also studied and found to be maximum in FYM plots. The metagenomic analysis of the rhizosphere microbial community revealed that the highest bacterial count was found in NC+PM plot as compared to standard check and untreated check. The diverse microbial population contributes to soil aggregation and stability. Healthier soil structures can improve water retention, aeration, and root penetration, which are all crucial for crop health. The further analysis also identified a total of 39 bacterial phyla, among which the most abundant were Actinobacteria, Firmicutes, and the SAR324 clade. Actinobacteria and Firmicutes are known for their roles in decomposing organic matter and mineralizing nutrients. Their highest abundance suggests improved nutrient cycling and availability, which can directly enhance plant growth. Hence, organic amendments in cabbage farming can transform the rhizosphere microbiome, reduce pest pressure, and foster populations of beneficial insects, leading to healthier crops and a more sustainable agricultural ecosystem.

Keywords: cabbage ecosystem, organic amendments, rhizosphere microbiome, pest and natural enemy diversity

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Authors: Amit Sarkar, Jayanta K. Mahato, Tushar Bhattacharya, Amrita Kundu, P. C. Chakraborti

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With increasing the demand for safety and fuel efficiency of automobiles, automotive manufacturers are looking for light weight, high strength steel with excellent formability and corrosion resistance. Dual-phase steel is finding applications in automotive sectors, because of its high strength, good formability, and high corrosion resistance. During service automotive components suffer from environmental attack and thereby gradual degradation of the components occurs reducing the service life of the components. The objective of the present investigation is to assess the effect of deformation on corrosion behaviour of DP590 grade dual phase steel which is used in automotive industries. The material was received from TATA Steel Jamshedpur, India in the form of 1 mm thick sheet. Tensile properties of the steel at strain rate of 10-3 sec-1: 0.2 % Yield Stress is 382 MPa, Ultimate Tensile Strength is 629 MPa, Uniform Strain is 16.30% and Ductility is 29%. Rectangular strips of 100x10x1 mm were machined keeping the long axis of the strips parallel to rolling direction of the sheet. These strips were longitudinally deformed at a strain rate at 10-3 sec-1 to a different percentage of strain, e.g. 2.5, 5, 7.5,10 and 12.5%, and then slowly unloaded. Small specimens were extracted from the mid region of the unclamped portion of these deformed strips. These small specimens were metallographic polished, and corrosion behaviour has been studied by potentiodynamic polarization, electrochemical impedance spectra, and cyclic polarization and potentiostatic tests. Present results show that among three different environments, the 3.5 pct NaCl solution is most aggressive in case of DP 590 dual-phase steel. It is observed that with the increase in the amount of deformation, corrosion rate increases. With deformation, the stored energy increases and leads to enhanced corrosion rate. Cyclic polarization results revealed highly deformed specimen are more prone to pitting corrosion as compared to the condition when amount of deformation is less. It is also observed that stability of the passive layer decreases with the amount of deformation. With the increase of deformation, current density increases in a passive zone and passive zone is also decreased. From Electrochemical impedance spectroscopy study it is found that with increasing amount of deformation polarization resistance (Rp) decreases. EBSD results showed that average geometrically necessary dislocation density increases with increasing strain which in term increased galvanic corrosion as dislocation areas act as the less noble metal.

Keywords: dual phase 590 steel, prestrain, potentiodynamic polarization, cyclic polarization, electrochemical impedance spectra

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Authors: Fatima Zahra Falah, Touria El. Ghailassi, Samia Yousfi, Ahmed Moussaif, Hasna Hamdane, Mouna Latifa Bouamrani

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The management and treatment of radioactive wastewater pose significant challenges to environmental safety and public health. This study presents an innovative approach to optimizing radioactive wastewater treatment using a novel biosorbent: chitosan-argan nutshell beads. By employing Response Surface Methodology (RSM), we aimed to determine the optimal conditions for maximum removal efficiency of radioactive contaminants. Chitosan, a biodegradable and non-toxic biopolymer, was combined with argan nutshell powder to create composite beads. The argan nutshell, a waste product from argan oil production, provides additional adsorption sites and mechanical stability to the biosorbent. The beads were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD) to confirm their structure and composition. A three-factor, three-level Box-Behnken design was utilized to investigate the effects of pH (3-9), contact time (30-150 minutes), and adsorbent dosage (0.5-2.5 g/L) on the removal efficiency of radioactive isotopes, primarily focusing on cesium-137. Batch adsorption experiments were conducted using synthetic radioactive wastewater with known concentrations of these isotopes. The RSM analysis revealed that all three factors significantly influenced the adsorption process. A quadratic model was developed to describe the relationship between the factors and the removal efficiency. The model's adequacy was confirmed through analysis of variance (ANOVA) and various diagnostic plots. Optimal conditions for maximum removal efficiency were pH 6.8, a contact time of 120 minutes, and an adsorbent dosage of 0.8 g/L. Under these conditions, the experimental removal efficiency for cesium-137 was 94.7%, closely matching the model's predictions. Adsorption isotherms and kinetics were also investigated to elucidate the mechanism of the process. The Langmuir isotherm and pseudo-second-order kinetic model best described the adsorption behavior, indicating a monolayer adsorption process on a homogeneous surface. This study demonstrates the potential of chitosan-argan nutshell beads as an effective and sustainable biosorbent for radioactive wastewater treatment. The use of RSM allowed for the efficient optimization of the process parameters, potentially reducing the time and resources required for large-scale implementation. Future work will focus on testing the biosorbent's performance with real radioactive wastewater samples and investigating its regeneration and reusability for long-term applications.

Keywords: adsorption, argan nutshell, beads, chitosan, mechanism, optimization, radioactive wastewater, response surface methodology

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Authors: Yu-Ju Tsai, Ching-Chun Wang, Wen-Tzu Tang, Huei-Ming Chai

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A pronated foot is frequently associated with a hypermobile first ray, then developing further severe foot problems. Low-Dye taping with athletic tape has been widely used to restrict excessive first ray motion and re-build height of the medial longitudinal arch in general population with pronated foot. It is not the case, however, for sprinters since they feel too much restriction of foot motions. Currently, the kinesio tape, more elastic than the athletic tape, has been widely used to re-adjust joint positions. It was interesting whether modified low-Dye taping using kinesio tape was beneficial for altering first ray mobility and still giving enough arch support. The purpose of this study was to investigate the effect of modified low-Dye taping on first ray mobility test and 60-m sprint time for sprinters with pronated foot. The significance of this study provides new insight into a treatment alternative of modified low-Dye taping for sprinter with pronated foot. Ten young male sprinters, aged 20.8±1.6 years, with pronated foot were recruited for this study. The pronated foot was defined as the foot that the navicular drop test was greater than 1.0 cm. Three optic shutters were placed at the start, 30-m, and 60-m sites to record sprint time. All participants were asked to complete 3 trials of the 60-m dash with both taping and non-taping conditions in a random order. The low-Dye taping was applied using the method postulated by Ralph Dye in 1939 except the kinesio tape was used instead. All outcome variables were recorded for taping and non-taping conditions. Paired t-tests were used to analyze all outcome variables between 2 conditions. Although there were no statistically significant differences in dorsal and plantar mobility between taping and non-taping conditions, a statistical significance was found in a total range of motion (dorsiflexion plus plantarflexion angle) of the first ray when a modified low-Dye taping was applied (p < 0.05). Time to complete 60-m sprint was significantly increased with low-Dye taping (p < 0.05) while no significance was found for time to 30-m. it indicated that modified low-Dye taping changed maximum sprint speed of 60-m dash. Conclusively, modified low-Dye taping was capable of increasing first ray mobility and further altered maximum sprint speed.

Keywords: first ray mobility, kinesio taping, pronated foot, sprint time

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Authors: Guanyu Jiang, Donghai Xu, Huanteng Liu

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After the Fukushima-Daiichi accident, the development of accident tolerant fuel cladding materials to improve reactor safety has become a hot topic in the field of nuclear industry. ZrO₂ has a satisfactory neutron economy and can guarantee the fission chain reaction process, which enables it to be a promising coating for zirconium alloy cladding. Maintaining a good corrosion resistance in primary coolant loop during normal operations of Pressurized Water Reactors is a prerequisite for ZrO₂ as a protective coating on zirconium alloy cladding. Research on the corrosion performance of ZrO₂ coating in nuclear water chemistry is relatively scarce, and existing reports failed to provide an in-depth explanation for the failure causes of ZrO₂ coating. Herein, a detailed corrosion process of ZrO₂ coating in lithiated water at 360 °C and 18.5 MPa was proposed based on experimental research and molecular dynamics simulation. Lithiated water with different LiOH solutions in the present work was deaerated and had a dissolved oxygen concentration of < 10 ppb. The concentration of Li (as LiOH) was determined to be 2.3 ppm, 70 ppm, and 500 ppm, respectively. Corrosion tests were conducted in a static autoclave. Modeling and corresponding calculations were operated on Materials Studio software. The calculation of adsorption energy and dynamics parameters were undertaken by the Energy task and Dynamics task of the Forcite module, respectively. The protective effect and failure mechanism of ZrO₂ coating on Zry-4 under varied LiOH concentrations was further revealed by comparison with the coating corrosion performance in pure water (namely 0 ppm Li). ZrO₂ coating provided a favorable corrosion protection with the occurrence of localized corrosion at low LiOH concentrations. Factors influencing corrosion resistance mainly include pitting corrosion extension, enhanced Li+ permeation, short-circuit diffusion of O²⁻ and ZrO₂ phase transformation. In highly-concentrated LiOH solutions, intergranular corrosion, internal oxidation, and perforation resulted in coating failure. Zr ions were released to coating surface to form flocculent ZrO₂ and ZrO₂ clusters due to the strong diffusion and dissolution tendency of α-Zr in the Zry-4 substrate. Considering that primary water of Pressurized Water Reactors usually includes 2.3 ppm Li, the stability of ZrO₂ make itself a candidate fuel cladding coating material. Under unfavorable conditions with high Li concentrations, more boric acid should be added to alleviate caustic corrosion of ZrO₂ coating once it is used. This work can provide some references to understand the service behavior of nuclear coatings under variable water chemistry conditions and promote the in-pile application of ZrO₂ coating.

Keywords: ZrO₂ coating, Zry-4, corrosion behavior, failure mechanism, LiOH concentration

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Authors: Dorna Kargar, Mehrasa Masih

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Due to its special geological and geographical conditions, Iran has always been exposed to various natural hazards. Earthquake is one of the natural hazards with random nature that can cause significant financial damages and casualties. This is a serious threat, especially in areas with active faults. Therefore, considering the population density in some parts of the country, locating and zoning high-risk areas are necessary and significant. In the present study, seismic hazard assessment via probabilistic and deterministic method for Tehran, the capital of Iran, which is located in Alborz-Azerbaijan province, has been done. The seismicity study covers a range of 200 km from the north of Tehran (X=35.74° and Y= 51.37° in LAT-LONG coordinate system) to identify the seismic sources and seismicity parameters of the study region. In order to identify the seismic sources, geological maps at the scale of 1: 250,000 are used. In this study, we used Kijko-Sellevoll's method (1992) to estimate seismicity parameters. The maximum likelihood estimation of earthquake hazard parameters (maximum regional magnitude Mmax, activity rate λ, and the Gutenberg-Richter parameter b) from incomplete data files is extended to the case of uncertain magnitude values. By the combination of seismicity and seismotectonic studies of the site, the acceleration with antiseptic probability may happen during the useful life of the structure is calculated with probabilistic and deterministic methods. Applying the results of performed seismicity and seismotectonic studies in the project and applying proper weights in used attenuation relationship, maximum horizontal and vertical acceleration for return periods of 50, 475, 950 and 2475 years are calculated. Horizontal peak ground acceleration on the seismic bedrock for 50, 475, 950 and 2475 return periods are 0.12g, 0.30g, 0.37g and 0.50, and Vertical peak ground acceleration on the seismic bedrock for 50, 475, 950 and 2475 return periods are 0.08g, 0.21g, 0.27g and 0.36g.

Keywords: peak ground acceleration, probabilistic and deterministic, seismic hazard assessment, seismicity parameters

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Authors: Shabnam Sarwar, Franck Lacoeuille, Nadia Withofs, Roland Hustinx

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After the development of a potential surrogate of MAA, and its successful application for the diagnosis of pulmonary embolism in artificially embolized rats’ lungs, this microparticulate system were radiolabelled with gallium-68 to synthesize 68Ga-SBMP with high radiochemical purity >99%. As a prerequisite step of clinical trials, 68Ga- labelled starch based microparticles (SBMP) were analysed for their in-vivo behavior in small animals. The purpose of the presented work includes the ex-vivo biodistribution studies of 68Ga-SBMP in order to assess the activity uptake in target organs with respect to time, excretion pathways of the radiopharmaceutical, %ID/g in major organs, T/NT ratios, in-vivo stability of the radiotracer and subsequently the microparticles in the target organs. Radiolabelling of starch based microparticles was performed by incubating it with 68Ga generator eluate (430±26 MBq) at room temperature and pressure without using any harsh reaction condition. For Ex-vivo biodistribution studies healthy White Wistar rats weighing between 345-460 g were injected intravenously 68Ga-SBMP 20±8 MBq, containing about 2,00,000-6,00,000 SBMP particles in a volume of 700µL. The rats were euthanized at predefined time intervals (5min, 30min, 60min and 120min) and their organ parts were cut, washed, and put in the pre-weighed tubes and measured for radioactivity counts through automatic Gamma counter. The 68Ga-SBMP produced >99% RCP just after 10-20 min incubation through a simple and robust procedure. Biodistribution of 68Ga-SBMP showed that initially just after 5 min post injection major uptake was observed in the lungs following by blood, heart, liver, kidneys, bladder, urine, spleen, stomach, small intestine, colon, skin and skeleton, thymus and at last the smallest activity was found in brain. Radioactivity counts stayed stable in lungs with gradual decrease with the passage of time, and after 2h post injection, almost half of the activity were seen in lungs. This is a sufficient time to perform PET/CT lungs scanning in humans while activity in the liver, spleen, gut and urinary system decreased with time. The results showed that urinary system is the excretion pathways instead of hepatobiliary excretion. There was a high value of T/NT ratios which suggest fine tune images for PET/CT lung perfusion studies henceforth further pre-clinical studies and then clinical trials should be planned in order to utilize this potential lung perfusion agent.

Keywords: starch based microparticles, gallium-68, biodistribution, target organs, excretion pathways

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Authors: Maya Saade, Rafic Younes, Pascal Lafon

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This paper explores the transformative impact of smartphones on pedagogy and presents a smartphone application developed specifically for engineering problem-solving and educational purposes. The widespread availability and advanced capabilities of smartphones have revolutionized the way we interact with technology, including in education. The ubiquity of smartphones allows learners to access educational resources anytime and anywhere, promoting personalized and self-directed learning. The first part of this paper discusses the overall influence of smartphones on pedagogy, emphasizing their potential to improve learning experiences through mobile technology. In the context of engineering education, this paper focuses on the development of a dedicated smartphone application that serves as a powerful tool for both engineering problem-solving and education. The application features an intuitive and user-friendly interface, allowing engineering students and professionals to perform complex calculations and analyses on their smartphones. The smartphone application primarily focuses on beam calculations and serves as a comprehensive beam calculator tailored to engineering education. It caters to various engineering disciplines by offering interactive modules that allow students to learn key concepts through hands-on activities and simulations. With a primary emphasis on beam analysis, this application empowers users to perform calculations for statically determinate beams, statically indeterminate beams, and beam buckling phenomena. Furthermore, the app includes a comprehensive library of engineering formulas and reference materials, facilitating a deeper understanding and practical application of the fundamental principles in beam analysis. By offering a wide range of features specifically tailored for beam calculation, this application provides an invaluable tool for engineering students and professionals looking to enhance their understanding and proficiency in this crucial aspect of a structural engineer.

Keywords: mobile devices in education, solving engineering problems, smartphone application, engineering education

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Authors: A. Cervantes-Diaz, B. Sevilla-Moran, Manuel Alcami, Al Mokhtar Lamsabhi, J. L. Alonso-Prados, P. Sandin-España

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Profoxydim is a post-emergence herbicide belonging to the cyclohexanedione oxime family, used to control weeds in rice crops. The use of soil organic amendments has increased significantly in the last decades, and their effects on the behavior of many herbicides are still unknown. Additionally, it is known that photolysis is an important degradation process to be considered when evaluating the persistence of this family of herbicides in the environment. In this work, the photodegradation of profoxydim in an amended paddy soil-water system with alperujo compost was studied. Photodegradation experiments were carried out under laboratory conditions using simulated solar light (Suntest equipment) in order to evaluate the reaction kinetics of the active substance. The photochemical behavior of profoxydim was investigated in soil with and without alperujo amendment. Furthermore, due to the rice crop characteristics, profoxydim photodegradation in water in contact with these types of soils was also studied. Determination of profoxydim degradation kinetics was performed by High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD). Furthermore, we followed the evolution of resulting transformation by-products, and their tentative identification was achieved by mass spectrometry. All the experiments allowed us to fit the data of profoxydim photodegradation to a first-order kinetic. Photodegradation of profoxydim was very rapid in all cases. The half-lives in aqueous matrices were in the range of 86±0.3 to 103±0.5 min. The addition of alperujo amendment to the soil produced an increase in the half-life from 62±0.2 min (soil) to 75±0.3 min (amended soil). In addition, a comparison to other organic amendments was also performed. Results showed that the presence of the organic amendment retarded the photodegradation in paddy soil and water. Regarding degradation products, the main process involved was the cleavage of the oxime moiety giving rise to the formation of the corresponding imine compound.

Keywords: by-products, herbicide, organic amendment, photodegradation, profoxydim

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Authors: Robert Wimmer, Soeren Eikemeier, Michael Berger, Anita Preisler

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A relatively large percentage of energy and resource consumption occurs in the building sector. This concerns the production of building materials, the construction of buildings and also the energy consumption during the use phase. Therefore, the overall objective of this EU LIFE project “LIFE Cycle Habitation” (LIFE13 ENV/AT/000741) is to demonstrate innovative building concepts that significantly reduce CO₂emissions, mitigate climate change and contain a minimum of grey energy over their entire life cycle. The project is being realised with the contribution of the LIFE financial instrument of the European Union. The ultimate goal is to design and build prototypes for carbon-neutral and “LIFE cycle”-oriented residential buildings and make energy-efficient settlements the standard of tomorrow in line with the EU 2020 objectives. To this end, a resource and energy-efficient building compound is being built in Böheimkirchen, Lower Austria, which includes 6 living units and a community area as well as 2 single family houses with a total usable floor surface of approximately 740 m². Different innovative straw bale construction types (load bearing and pre-fabricated non loadbearing modules) together with a highly innovative energy-supply system, which is based on the maximum use of thermal energy for thermal energy services, are going to be implemented. Therefore only renewable resources and alternative energies are used to generate thermal as well as electrical energy. This includes the use of solar energy for space heating, hot water and household appliances like dishwasher or washing machine, but also a cooking place for the community area operated with thermal oil as heat transfer medium on a higher temperature level. Solar collectors in combination with a biomass cogeneration unit and photovoltaic panels are used to provide thermal and electric energy for the living units according to the seasonal demand. The building concepts are optimised by support of dynamic simulations. A particular focus is on the production and use of modular prefabricated components and building parts made of regionally available, highly energy-efficient, CO₂-storing renewable materials like straw bales. The building components will be produced in collaboration by local SMEs that are organised in an efficient way. The whole building process and results are monitored and prepared for knowledge transfer and dissemination including a trial living in the residential units to test and monitor the energy supply system and to involve stakeholders into evaluation and dissemination of the applied technologies and building concepts. The realised building concepts should then be used as templates for a further modular extension of the settlement in a second phase.

Keywords: energy-efficiency, green architecture, renewable resources, sustainable building

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Authors: Agbana Olaseinde Julius, Opadere Olaolu Stephen

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The concept of cross carpeting is as old as politics itself. Basically, it entails an individual leaving a political party/group, to join another. The reasons for which cross carpeting is embarked upon are diverse: ideological differences; ethnic and/or religious differences; access to actual or perceived better political opportunities; liberty of association; rancor; etc. The current democratic dispensation in Nigeria has experienced renewed and rather alarming rate of cross carpeting, for reasons including those enumerated above and others. Right to cross carpet is inherent in a democratic setting as well as the political stakeholder; so does it also comprise of the constitutional right of ‘freedom of association’. However, the current species of cross carpeting in Nigeria requires scrutiny, in view of some potential legal and moral challenges it poses for both the present and the future. Cross carpeting is considered both legal and constitutional, but the current spate raises the question of expediency, particularly in a nascent democracy. It is considered to have a propensity of negatively impacting political stability in a polity with fragile nerves. Importantly too, cross carpeting is considered a potential damage to the psyche of posterity with regards to a warped disposition to promises, honour and integrity. The perceived peculiar dimension of cross carpeting in Nigeria raises questions on the quality of leadership presently obtainable in the country, vis-à-vis greed, self-centeredness, disregard for the concern and interest of avowed followers/fans, entrenchment of distrust, etc. Thus, the study made use of primary and secondary sources of information. The primary sources included the Constitutions of the Federal Republic of Nigeria 1999 (as amended); judicial decisions; and the Electoral Act, 2010 (as Amended). The secondary sources comprised of information from books, journals, newspapers, magazines and Internet documents. Data obtained from these sources were subjected to content analysis. Findings of this study show that though the act of cross carpeting may not be in breach of any Statute or Law, it however, in most cases, breaches the morals of expediency. The morality thereof is far from justifiable, and should be condemned in the interest of the present and posterity. There is a great and urgent need to embark on a re-entrenchment of the culture of political ideology in the Nigerian polity, as obtainable in developed democracies. In conclusion, the need to exercise the right of cross carpeting with caution cannot be overemphasized. Membership of a political group/party should be backed by commitment to well defined ideologies and values. Commitment to them should be regarded akin to that found in the family, which is not easily or flippantly jettisoned.

Keywords: cross-carpeting, Nigeria, legal, moral issues, politics

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Authors: M. Moncef Khaddar

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This paper focuses mainly on a contextualized understanding of ‘autocratic authoritarianism’ in Tunisia without approaching its peculiarities in reference to the ideal type of capitalist-liberal democracy but rather analysing it as a Tunisian ‘civilian dictatorship’. This is reminiscent, to some extent, of the French ‘colonial authoritarianism’ in parallel with the legacy of the traditional formal monarchic absolutism. The Tunisian autocratic political system is here construed as a state manufactured nationalist-populist authoritarianism associated with a de facto presidential single party, two successive autocratic presidents and their subservient autocratic elites who ruled with an iron fist the de-colonialized ‘liberated nation’ that came to be subjected to a large scale oppression and domination under the new Tunisian Republic. The diachronic survey of Tunisia’s autocratic authoritarian system covers the early years of autocracy, under the first autocratic president Bourguiba, 1957-1987, as well as the different stages of its consolidation into a police-security state under the second autocratic president, Ben Ali, 1987-2011. Comparing the policies of authoritarian regimes, within what is identified synchronically as a bi-cephalous autocratic system, entails an in-depth study of the two autocrats, who ruled Tunisia for more than half a century, as modern adaptable autocrats. This is further supported by an exploration of the ruling authoritarian autocratic elites who played a decisive role in shaping the undemocratic state-society relations, under the 1st and 2nd President, and left an indelible mark, structurally and ideologically, on Tunisian polity. Emphasis is also put on the members of the governmental and state-party institutions and apparatuses that kept circulating and recycling from one authoritarian regime to another, and from the first ‘founding’ autocrat to his putschist successor who consolidated authoritarian stability, political continuity and autocratic governance. The reconfiguration of Tunisian political life, in the post-autocratic era, since 2011 will be analysed. This will be scrutinized, especially in light of the unexpected return of many high-profile figures and old guards of the autocratic authoritarian apparatchiks. How and why were, these public figures, from an autocratic era, able to return in a supposedly post-revolutionary moment? Finally, while some continue to celebrate the putative exceptional success of ‘democratic transition’ in Tunisia, within a context of ‘unfinished revolution’, others remain perplexed in the face of a creeping ‘oligarchic transition’ to a ‘hybrid regime’, characterized rather by elites’ reformist tradition than a bottom-up genuine democratic ‘change’. This latter is far from answering the 2010 ordinary people’s ‘uprisings’ and ‘aspirations, for ‘Dignity, Liberty and Social Justice’.

Keywords: authoritarianism, autocracy, democratization, democracy, populism, transition, Tunisia

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Authors: Fangfei Li

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Studies on teacher feedback have produced a wide range of findings in aspects of characteristics of good feedback, factors influencing the quality of feedback and teachers’ perspectives on teacher feedback. However, perspectives from students on how they perceive and respond to teacher feedback are still under scrutiny. Especially for Chinese overseas students who come from a feedback-sparse educational context in China, they might have different experiences when engaging with teacher feedback in the UK Higher Education. Therefore, the research aims to investigate and shed some new light on how Chinese students engage with teacher feedback in the UK higher education and how teacher feedback could enhance their learning. Research questions of this study are 1) What are Chinese overseas students’ perceptions of teacher feedback in courses of the UK higher education? 2) How do they respond to the teacher feedback they obtained? 3) What factors might influence their’ engagement with teacher feedback? Qualitative case studies of five Chinese postgraduate students in a UK university have been conducted by employing various types of interviews, such as background interviews, scenario-based interviews, stimulated recall interviews and retrospective interviews to address the research inquiries. Data collection lasted seven months, covering two phases – the pre-sessional language programme and the first semester of the Master’s degree programme. Research findings until now indicate that some factors, such as tutors’ handwriting, implicit instruction and value comments, influence students understanding and internalizing tutor feedback. Except for difficulties in understanding tutor feedback, students’ responses to tutor feedback are also influenced by quantity and quality of tutor-student communication, time constraints and trust to tutor feedback, etc. Findings also reveal that tutor feedback is able to improve students’ learning in aspects of promoting reflection on professional knowledge, promoting students’ communication with peers and tutors, increasing problem awareness and writing with the reader in mind. This paper will mainly introduce the research topic, the methodological procedure and research findings gained until now.

Keywords: Chinese students, students’ perceptions, teacher feedback, the UK higher education

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Authors: Salma H. Abu Hafsa, A. Mendonca, B. Brehm-Stecher, A. A. Hassan, S. A. Ibrahim

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Enterococci are important inhabitants of the animal intestine and are widely used in probiotic products. A probiotic strain is expected to possess several desirable properties in order to exert beneficial effects. Therefore, the objective of this study was to isolate and characterize strains of Enterococcus sp. from chicken cecal and fecal samples to determine potential probiotic properties. Enterococci were isolated from thirty one chicken cecal and fecal samples collected from a local farm. In vitro studies were performed to assess antibacterial activity (using agar well diffusion and cell free supernatant broth technique against Salmonella enterica serotype Enteritidis), susceptibility to antibiotics (amoxycillin, cotrimoxazole, chloramphenicol, cefuroxime, ceftriaxone, ciprofloxacin, and nalidixic acid), survival in acidic conditions, resistance to bile salts, and their survival during simulated gastric juice conditions at pH 2.5. Isolates were identified using biochemical and molecular assays (API 50 CHL, and API ZYM kits followed by 16S rDNA gene sequence analysis). Two strains were identified, of which, Enteroccocus faecium was capable of inhibiting the growth of S. enteritidis and was susceptible to a wide range of antibiotics. In addition, the isolated strain exhibited significant resistance under highly acidic conditions (pH=2.5) for 8 hours and survived well in bile salt at 0.2% for 24 hours and showing ability to survive in the presence of simulated gastric juice at pH 2.5. Based on these results, the E. faecium isolate fulfills some of the criteria to be considered as a probiotic strain and therefore, could be used as a feed additive with good potential for controlling S. enteritidis in chickens. However, in vivo studies are needed to determine the safety of the strain.

Keywords: acid tolerance, antimicrobial activity, Enterococcus faecium, probiotic

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Authors: Vladimir Messerle, Alfred Mosse, Alexandr Ustimenko, Oleg Lavrichshev

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Hygiene and sanitary study of typical medical-biological waste made in Kazakhstan, Russia, Belarus and other countries show that their risk to the environment is much higher than that of most chemical wastes. For example, toxicity of solid waste (SW) containing cytotoxic drugs and antibiotics is comparable to toxicity of radioactive waste of high and medium level activity. This report presents the results of the thermodynamic analysis of thermal processing of SW and experiments at the developed plasma unit for SW processing. Thermodynamic calculations showed that the maximum yield of the synthesis gas at plasma gasification of SW in air and steam mediums is achieved at a temperature of 1600K. At the air plasma gasification of SW high-calorific synthesis gas with a concentration of 82.4% (СO – 31.7%, H2 – 50.7%) can be obtained, and at the steam plasma gasification – with a concentration of 94.5% (СO – 33.6%, H2 – 60.9%). Specific heat of combustion of the synthesis gas produced by air gasification amounts to 14267 kJ/kg, while by steam gasification - 19414 kJ/kg. At the optimal temperature (1600 K), the specific power consumption for air gasification of SW constitutes 1.92 kWh/kg, while for steam gasification - 2.44 kWh/kg. Experimental study was carried out in a plasma reactor. This is device of periodic action. The arc plasma torch of 70 kW electric power is used for SW processing. Consumption of SW was 30 kg/h. Flow of plasma-forming air was 12 kg/h. Under the influence of air plasma flame weight average temperature in the chamber reaches 1800 K. Gaseous products are taken out of the reactor into the flue gas cooling unit, and the condensed products accumulate in the slag formation zone. The cooled gaseous products enter the gas purification unit, after which via gas sampling system is supplied to the analyzer. Ventilation system provides a negative pressure in the reactor up to 10 mm of water column. Condensed products of SW processing are removed from the reactor after its stopping. By the results of experiments on SW plasma gasification the reactor operating conditions were determined, the exhaust gas analysis was performed and the residual carbon content in the slag was determined. Gas analysis showed the following composition of the gas at the exit of gas purification unit, (vol.%): СO – 26.5, H2 – 44.6, N2–28.9. The total concentration of the syngas was 71.1%, which agreed well with the thermodynamic calculations. The discrepancy between experiment and calculation by the yield of the target syngas did not exceed 16%. Specific power consumption for SW gasification in the plasma reactor according to the results of experiments amounted to 2.25 kWh/kg of working substance. No harmful impurities were found in both gas and condensed products of SW plasma gasification. Comparison of experimental results and calculations showed good agreement. Acknowledgement—This work was supported by Ministry of Education and Science of the Republic of Kazakhstan and Ministry of Education and Science of the Russian Federation (Agreement on grant No. 14.607.21.0118, project RFMEF160715X0118).

Keywords: coal, efficiency, ignition, numerical modeling, plasma-fuel system, plasma generator

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Authors: Anca Dinischiotu, Sorina Nicoleta Voicu

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Silica nanoparticles (SiO2-NPs) are widely used in consumer products such as paints, plastics, insulation materials, tires, concrete production, as well as in gene delivery systems and imaging procedures. Environmental human exposure to them occurs during utilization of these products, in a time-dependent manner, the uptake being by topic and inhalation route especially. SiO2-NPs enter cells and induce membrane damage, oxidative stress and inflammatory reactions in a concentration-dependent manner. In this study, MRC-5 cells (human fetal lung fibroblasts) were exposed to amorphous SiO2-NPs at a dose of 62.5 μg/ml for 24, 48 and 72 hours. The size distribution of NPs was a lognormal function, in the range 3-14 nm. A time-dependent decrease of total reduced glutathione concentration by 36%, 50%, and 78% and an increase of NO level by 62%, 32%, respectively 24% compared to control were noticed. An up-regulation of NF-kB expression by 20%, 50% respectively 10% and of Nrf-2 by 139%, 58%, and 16% compared to control after 24, 48 and 72 hours was noticed also. The expression of IL-1β, IL-6, IL-8, and COX-2 was up-regulated in a time-dependent manner. Also, the expression of MMP-2 and MMP-9 were down-regulated after 48 and 72 hours, whereas their activities raised in a time-dependent manner. Exposure of cells to NPs up-regulated the expression of inducible NO synthase, as previously was shown, and probably this is the reason for the increased level of NO, that can react with the thiol groups of reduced glutathione molecules, diminishing its concentration Nrf2 is a transcription factor translocated in nucleus, under oxidative stress, where downstream gene expression activates in order to modulate the adaptive intracellular response against oxidative stress. The cross-talk between Nrf2 and NF-kB activities regulates the inflammatory processes. The activation of NF-kB could activate up-regulation of IL-1β, IL-6, and IL-8. The increase of COX-2 expression could be correlated with IL-1β one. Also, probably in response to the pro-inflammatory cytokines, MMP-2 and MMP-9 were induced and activated. In conclusion, the exposure of MRC-5 cells to SiO2-NPs generated inflammation in a time-dependent manner.

Keywords: inflammation, MRC-5 cells, oxidative stress, silica nanoparticles

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Authors: Gunta Resevica, Nikita Zrelovs, Ivars Silamikelis, Ieva Kalnciema, Helvijs Niedra, Gunārs Lācis, Toms Bartulsons, Inga Moročko-Bičevska, Arturs Stalažs, Kristīne Drevinska, Andris Zeltins, Ina Balke

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Newly discovered viruses provide novel knowledge for basic phytovirus research, serve as tools for biotechnology and can be helpful in identification of epidemic outbreaks. Blackcurrant-associated rhabdovirus (BCaRV) have been discovered in USA germplasm collection samples from Russia and France. As it was reported in one accession originating from France it is unclear whether the material was already infected when it entered in the USA or it became infected while in collection in the USA. Due to that BCaRV was definite as non-EU viruses. According to ICTV classification BCaRV is representative of Blackcurrant betanucleorhabdovirus specie in genus Betanucleorhabdovirus (family Rhabdoviridae). Nevertheless, BCaRV impact on the host, transmission mechanisms and vectors are still unknown. In RNA-seq data pool from Ribes plants resistance gene study by high throughput sequencing (HTS) we observed differences between sample group gene transcript heat maps. Additional analysis of the whole data pool (total 393660492 of 150 bp long read pairs) by rnaSPAdes v 3.13.1 resulted into 14424 bases long contig with an average coverage of 684x with shared 99.5% identity to the previously reported first complete genome of BCaRV (MF543022.1) using EMBOSS Needle. This finding proved BCaRV presence in EU and indicated that it might be relevant pathogen. In this study leaf tissue from twelve asymptomatic blackcurrant cv. Mara Eglite plants (negatively tested for blackcurrant reversion virus (BRV)) from Dobele, Latvia (56°36'31.9"N, 23°18'13.6"E) was collected and used for total RNA isolation with RNeasy Plant Mini Kit with minor modifications, followed by plant rRNA removal by a RiboMinus Plant Kit for RNA-Seq. HTS libraries were prepared using MGI Easy RNA Directional Library Prep Set for 16 reactions to obtain 150 bp pair-end reads. Libraries were pooled, circularized and cleaned and sequenced on DNBSEQ-G400 using PE150 flow cell. Additionally, all samples were tested by RT-PCR, and amplicons were directly sequenced by Sanger-based method. The contig representing the genome of BCaRV isolate Mara Eglite was deposited at European Nucleotide Archive under accession number OU015520. Those findings indicate a second evidence on the presence of this particular virus in the EU and further research on BCaRV prevalence in Ribes from other geographical areas should be performed. As there are no information on BCaRV impact on the host this should be investigated, regarding the fact that mixed infections with BRV and nucleorhabdoviruses are reported.

Keywords: BCaRV, Betanucleorhabdovirus, Ribes, RNA-seq

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Authors: Giovanna Grosso, Martien A. Hulsen, Arash Sarhangi Fard, Andrew Overend, Patrick. D. Anderson

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In many industrial applications and, in particular in polymer industry, the quality of mixing between different materials is fundamental to guarantee the desired properties of finished products. However, properly modelling and understanding polymer mixing often presents noticeable difficulties, because of the variety and complexity of the physical phenomena involved. This is the case of the Cavity Transfer Mixer (CTM), for which a clear understanding of mixing mechanisms is still missing, as well as clear guidelines for the system optimization. This device, invented and patented by Gale at Rapra Technology Limited, is an add-on to be mounted downstream of existing extruders, in order to improve distributive mixing. It consists of two concentric cylinders, the rotor and stator, both provided with staggered rows of hemispherical cavities. The inner cylinder (rotor) rotates, while the outer (stator) remains still. At the same time, the pressure load imposed upstream, pushes the fluid through the CTM. Mixing processes are driven by the flow field generated by the complex interaction between the moving geometry, the imposed pressure load and the rheology of the fluid. In such a context, the present work proposes a complete and accurate three dimensional modelling of the CTM and results of a broad range of simulations assessing the impact on mixing of several geometrical and functioning parameters. Among them, we find: the number of cavities per row, the number of rows, the size of the mixer, the rheology of the fluid and the ratio between the rotation speed and the fluid throughput. The model is composed of a flow part and a mixing part: a finite element solver computes the transient velocity field, which is used in the mapping method implementation in order to simulate the concentration field evolution. Results of simulations are summarized in guidelines for the device optimization.

Keywords: Mixing, non-Newtonian fluids, polymers, rheology.

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Authors: M. Alkhalidi, S. Neelamani, Z. Al-Zaqah

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This paper investigates the interaction of single and twin offshore rubble mound breakwaters with regular and random water waves through physical modeling to assess their reflection, transmission and energy dissipation characteristics. Various combinations of wave heights and wave periods were utilized in a series of experiments, along with three different water depths. The single and twin permeable breakwater models were both constructed with one layer of rubbles. Both models had the same total volume; however, the single breakwater was of trapezoidal type while the twin breakwaters were of triangular type. Physical modeling experiments were carried out in the wave flume of the coastal engineering laboratory of Kuwait Institute for Scientific Research (KISR). Measurements of the six wave probes which were fixed in the two-dimensional wave flume were collected and used to determine the generated incident wave heights, as well as the reflected and transmitted wave heights resulting from the wave-breakwater interaction. The possible factors affecting the wave attenuation efficiency of the breakwater models are the relative water depth (d/L), wave steepness (H/L), relative wave height ((h-d)/Hi), relative height of the breakwater (h/d), and relative clear spacing between the twin breakwaters (S/h). The results indicated that the single and double breakwaters show different responds to the change in their relative height as well as the relative wave height which demonstrates that the effect of the relative water depth on wave reflection, transmission, and energy dissipation is highly influenced by the change in the relative breakwater height, the relative wave height and the relative breakwater spacing. In general, within the range of the relative water depth tested in this study, and under both regular and random waves, it is found that the single breakwater allows for lower wave transmission and shows higher energy dissipation effect than both of the tested twin breakwaters, and hence has the best overall performance.

Keywords: random waves, regular waves, relative water depth, relative wave height, single breakwater, twin breakwater, wave steepness

Procedia PDF Downloads 327