Search results for: water pipeline model

Authors: N. Gigauri, V. Kukhalashvili, A. Surmava, L. Intskirveli, L. Gverdtsiteli

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Tbilisi, a large city of the South Caucasus, is a junction point connecting Asia and Europe, Russia and republics of the Asia Minor. Over the last years, its atmosphere has been experienced an increasing anthropogenic load. Numerical modeling method is used for study of Tbilisi atmospheric air pollution. By means of 3D non-linear non-steady numerical model a peculiarity of city atmosphere pollution is investigated during background western light air. Dust concentration spatial and time changes are determined. There are identified the zones of high, average and less pollution, dust accumulation areas, transfer directions etc. By numerical modeling, there is shown that the process of air pollution by the dust proceeds in four stages, and they depend on the intensity of motor traffic, the micro-relief of the city, and the location of city mains. In the interval of time 06:00-09:00 the intensive growth, 09:00-15:00 a constancy or weak decrease, 18:00-21:00 an increase, and from 21:00 to 06:00 a reduction of the dust concentrations take place. The highly polluted areas are located in the vicinity of the city center and at some peripherical territories of the city, where the maximum dust concentration at 9PM is equal to 2 maximum allowable concentrations. The similar investigations conducted in case of various meteorological situations will enable us to compile the map of background urban pollution and to elaborate practical measures for ambient air protection.

Keywords: air pollution, dust, numerical modeling, urban

Procedia PDF Downloads 165

Authors: Ira V. Stancheva, Ely G. Zayova, Maria P. Geneva, Marieta G. Hristozkova, Lyudmila I. Dimitrova, Maria I. Petrova

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The study describes a highly efficient and low-cost protocol for rapid and mass in vitro propagation of medicinal and aromatic plant species (Hyssopus officinalis L., Lamiaceae). Hyssop is an important aromatic herb used for its medicinal values because of its antioxidant, anti-inflammatory and antimicrobial properties. The protocol for large-scale multiplication of this aromatic plant was developed using young stem tips explants. The explants were sterilized with 0.04% mercuric chloride (HgCl₂) solution for 20 minutes and washing three times with sterile distilled water in 15 minutes. The cultural media was full and half strength Murashige and Skoog medium containing indole-3-butyric acid. Full and ½ Murashige and Skoog media without auxin were used as controls. For each variant 20 glass tubes with two plants were used. In each tube two tip and nodal explants were inoculated. Maximum shoot and root number were obtained on ½ Murashige and Skoog medium supplemented with 0.1 mg L-1 indole-3-butyric acid at the same time after four weeks of culture. The number of shoots per explant and shoot height were considered. The data on rooting percentage, the number of roots per plant and root length were collected after the same cultural period. The highest percentage of survival 85% for this medicinal plant was recorded in mixture of soil, sand and perlite (2:1:1 v/v/v). This mixture was most suitable for acclimatization of all propagated plants. Ex vitro acclimatization was carried out at 24±1 °C and 70% relative humidity under 16 h illuminations (50 μmol m⁻²s⁻¹). After adaptation period, the all plants were transferred to the field. The plants flowered within three months after transplantation. Phenotypic variations in the acclimatized plants were not observed. An average of 90% of the acclimatized plants survived after transferring into the field. All the in vitro propagated plants displayed normal development under the field conditions. Developed in vitro techniques could provide a promising alternative tool for large-scale propagation that increases the number of homologous plants for field cultivation. Acknowledgments: This study was conducted with financial support from National Science Fund at the Bulgarian Ministry of Education and Science, Project DN06/7 17.12.16.

Keywords: Hyssopus officinalis L., in vitro culture, micro propagation, acclimatization

Procedia PDF Downloads 297

Authors: H. Scholz, P. Kuehne, G. Heckenberger

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Dietary Anion-Cation Balance (DCAB) in grazing systems under German conditions has a tendency to decrease from May until September and often are measured DCAB lower than 100 meq per kg dry matter. Lower DCAB in grass feeding system can change the metabolic status of suckler cows and often are results in acidotic metabolism. Measurement of acid-base excretion in dairy cows has been proved to a method to evaluate the acid-base status. The hypothesis was that metabolic imbalances could be identified by urine measurement in suckler cows. The farm study was conducted during the grazing seasons 2017 and 2018 and involved 7 suckler cow farms in Germany. Suckler cows were grazing during the whole time of the investigation and had no access to other feeding components. Cows had free access to water and salt block and free access to minerals (loose). The dry matter of the grass was determined at 60 °C and were then analysed for energy and nutrient content and for the Dietary Cation-Anion Balance (DCAB). Urine was collected in 50 ml-glasses and analysed for net acid-base excretion (NSBA) and the concentration of creatinine and urea in the laboratory. Statistical analysis took place with ANOVA with fixed effects of farms (1-7), month (May until September), and number of lactations (1, 2, and ≥ 3 lactations) using SPSS Version 25.0 for windows. An alpha of 0.05 was used for all statistical tests. During the grazing periods of years 2017 and 2018, an average DCAB was observed in the grass of 167 meq per kg DM. A very high mean variation could be determined from -42 meq/kg to +439 meq/kg. Reference values in relation to DCAB were described between 150 meq and 400 meq per kg DM. It was found the high chlorine content with reduced potassium level led to this reduction in DCAB at the end of the grazing period. Between the DCAB of the grass and the NSBA in urine of suckler cows was a correlation according to PEARSON of r = 0.478 (p ≤ 0.001) or after SPEARMAN of r = 0.601 (p ≤ 0.001) observed. For the control of urine values of grazing suckler cows, the wide spread of the values poses a challenge of the interpretation, especially since the DCAB is unknown. The influence of several feeding components such as chlorine, sulfur, potassium, and sodium (ions for the DCAB) and dry matter feed intake during the grazing period of suckler cows should be taken into account in further research. The results obtained show that up a decrease in the DCAB is related to a decrease in NSBA in urine of suckler cows. Monitoring of metabolic disturbances should include analysis of urine, blood, milk, and ruminal fluid.

Keywords: dietary anion-cation balance, DCAB, net acid-base excretion, NSBA, suckler cow, grazing period

Procedia PDF Downloads 135

Authors: Qiao Mao

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There is a growing number of studies concerning STEM (Science, Technology, Engineering, and Mathematics) and STEAM (Science, Technology, Engineering, Arts, and Mathematics). However, the research is little on STEAM competitions from Arts' perspective. This study takes the annual PowerTech STEAM competition in Taiwan as an example. In this activity, students are asked to make wooden bionic mechanical beasts on the spot and participate in a model and speed competition. This study aims to explore how Arts influences STEM after it involves in the making of mechanical beasts. A case study method is adopted. Through expert sampling, five prize winners in the PowerTech Youth Science and Technology Creation Competition and their supervisors are taken as the research subjects. Relevant data which are collected, sorted out, analyzed and interpreted afterwards, derive from observations, interview and document analyses, etc. The results of the study show that in the PowerTech Youth Science and Technology Creation Competition, when Arts involves in STEM, (1) it has an impact on the athletic performance, balance, stability and symmetry of mechanical beasts; (2) students become more interested and more creative in making STEAM mechanical beasts, which can promote students' learning of STEM; (3) students encounter more difficulties and problems when making STEAM mechanical beasts, and need to have more systematic thinking and design thinking to solve problems.

Keywords: PowerTech, STEAM contest, mechanical beast, arts' role

Procedia PDF Downloads 68

Authors: J. Joy, T. H. New, I. H. Ibrahim

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A computational study on bio-inspired NACA634-021 hydrofoils with leading-edge protuberances has been carried out to investigate their hydrodynamic flow control characteristics at a Reynolds number of 14,000 and different angles-of-attack. The numerical simulations were performed using ANSYS FLUENT and based on Reynolds-Averaged Navier-Stokes (RANS) solver mode incorporated with k-ω Shear Stress Transport (SST) turbulence model. The results obtained indicate varying flow phenomenon along the peaks and troughs over the span of the hydrofoils. Compared to the baseline hydrofoil with no leading-edge protuberances, the leading-edge modified hydrofoils tend to reduce flow separation extents along the peak regions. In contrast, there are increased flow separations in the trough regions of the hydrofoil with leading-edge protuberances. Interestingly, it was observed that dissimilar flow separation behaviour is produced along different peak- or trough-planes along the hydrofoil span, even though the troughs or peaks are physically similar at each interval for a particular hydrofoil. Significant interactions between adjacent flow structures produced by the leading-edge protuberances have also been observed. These flow interactions are believed to be responsible for the dissimilar flow separation behaviour along physically similar peak- or trough-planes.

Keywords: computational fluid dynamics, flow separation control, hydrofoils, leading-edge protuberances

Procedia PDF Downloads 304

Authors: Weicheng Luo, Wenzhi Zhao

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Plants growth in desert often suffered from stresses like water deficit, wind erosion and sand burial. Thus, plants in desert always have unique strategies to adapt these stresses. However, data regarding how clonal shrubs withstand wind erosion and sand burial in natural habitats remain relatively scarce. Therefore, we selected a common clonal shrub Calligonum arborescens to study the adaptive strategies of clonal plants to sand dune environment in a transitional zone of desert and Hexi Oasis of China. Our results show that sand burial is one of the essential prerequisites for the survival of C. arborescens rhizome fragments. Both the time and degrees of sand burial and wind erosion had significantly effects on clonal reproduction and growth of C. arborescens. With increasing burial depth, the number of ramets and biomass production significantly decreased. There is same change trend in severe erosion treatments. However, the number of ramets and biomass production significantly increased in moderate erosion treatments. Rhizome severed greatly decreased ramet number and biomass production under both sand burial and severe erosion treatments. That indicated that both sand burial and severe erosion had negative effects on the clonal growth of C. arborescens, but moderate wind erosion had positive effects. And rhizome connections alleviated the negative effects of sand burial and of severe erosion on the growth and performance of C. arborescens. Most fragments of C. arborescens grew in the directions of northeastern and southwestern. Ramet number and biomass, rhizome length and biomass in these two directions were significantly higher than those found in other directions. Interestingly, these directions were perpendicular to the prevailing wind direction. Distribution of C. arborescens differed in different habitats. The total number of individuals was significantly higher in inter-dune areas and on windward slopes than on the top and leeward slopes of dunes; more clonal ramets were produced on the top of dunes than elsewhere, and a few were found on leeward slopes. The mainly reason is that ramets on windward and top of dunes can easily suffered with moderated wind erosion which promoted clonal growth and reproduction of C. arborescens. These results indicated that C. arborescens adapted sand dune environment through directional growth and patchy distribution, and sand-burial and wind erosion were the key factors which led to the directional growth and patchiness of C. arborescens.

Keywords: adaptive strategy, Calligonum arborescens Litv, clonal fragment, desert-oasis transitional zone, sand burial and wind erosion

Procedia PDF Downloads 218

Authors: Rômulo Eustáquio Martins de Souza, Paulo Alexandre Rodrigues de Vasconcelos Figueiredo

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In recent years, there has been a surge in interest in applying artificial intelligence techniques, particularly machine learning algorithms. Machine learning is a data-analysis technique that automates the creation of analytical models, making it especially useful for designing complex situations. As a result, this technology aids in reducing human intervention while producing accurate results. This methodology is also extensively used in aerospace engineering since this is a field that encompasses several high-complexity operations, such as rocket propulsion. Rocket propulsion is a high-risk operation in which engine failure could result in the loss of life. As a result, it is critical to use computational methods capable of precisely representing the spacecraft's analytical model to guarantee its security and operation. Thus, this paper describes the use of machine learning algorithms for rocket propulsion to aid the realization that this technique is an efficient way to deal with challenging and restrictive aerospace engineering activities. The paper focuses on three machine-learning-aided rocket propulsion applications: set-point control of an expander-bleed rocket engine, supersonic retro-propulsion of a small-scale rocket, and leak detection and isolation on rocket engine data. This paper describes the data-driven methods used for each implementation in depth and presents the obtained results.

Keywords: data analysis, modeling, machine learning, aerospace, rocket propulsion

Procedia PDF Downloads 91

Authors: Vathna Suy, Ki-Il Song

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In order to store highly pressurized gas such as an isothermal compressed air energy storage, Lined Rock Caverns (LRC) are constructed underground and supported by layers of concrete, steel and rock masses. This study aims to numerically investigate the performance of rock masses which serve as a support of Lined Rock Cavern subjected to high cyclic pressure loadings. FLAC3D finite different software is used for the simulation since the software can effectively model the behavior of concrete lining and steel plate with its built-in structural elements. Cyclic pressure loadings are applied onto the inner surface of the cavern which then transmitted to concrete, steel and eventually to the surrounding rock masses. Changes of stress and strain are constantly monitored throughout all the process of loading operations. The results at various monitoring locations are then extracted and analyzed to assess the response of the rock masses, specifically on its ability to absorb energy during loadings induced by the changes of cyclic pressure loadings inside the cavern. By analyzing the obtained data of stress-strain relation and taking into account the behavior of materials under the effect of strain-dependency, conclusions on the performance of rock masses subjected to high cyclic loading conditions are drawn.

Keywords: cyclic loading, FLAC3D, lined rock cavern (LRC), strain-dependency

Procedia PDF Downloads 230

Authors: Micheal O. Alabi

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Additive manufacturing (AM) is the official industry standard term (ASTM F2792) for all applications of the technology which is also known as 3D printing technology. It is defined as the process of joining materials to make objects from 3D model data, and it is usually layer upon layer, as opposed to subtractive manufacturing methodologies. This technology has gained significant interest within the academic, research institute and industry because of its ability to create complex geometries with customizable material properties. Despite the late adoption of the technology, additive manufacturing has been active in South Africa for past 21 years and it is predicted that additive manufacturing technology will play a significant and game-changing role in the fourth industrial revolution and in particular it promises to play an ever-growing role in efforts to re-industrialize the economy of South Africa. At the end of 2006, there are approximately ninety 3D printers in South Africa and in 2015 it was estimated that there are 3500 additive manufacturing systems and 3D printers in circulation in South Africa. A reasonable number of these additive manufacturing machines are in the high end of the market, in science councils and higher education institutions and this shows that the future of additive manufacturing in South Africa is very brighter compared to other African countries. This paper reviews the past and current industrial applications of additive manufacturing in South Africa from the academic research and industry perspective and what are the benefits of this technology to manufacturing companies and industrial sectors in the country.

Keywords: additive manufacturing, 3D printing technology, industrial applications, manufacturing

Procedia PDF Downloads 447

Authors: Xinke Huang, Huan Wang, Lidong Guo, Changbin Ju, Runbiao Liu, Guoen Cao, Yibo Wang, Honghua Xu

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Grid connected photovoltaic (PV) power system is to be developed in the direction of large-scale, clustering. Large-scale PV generation systems connected to HVDC grid have many advantages compared to its counterpart of AC grid, and DC connection is the tendency. DC/DC converter as the most important device in the system, has become one of the hot spots recently. The paper proposes a Quasi Z-Source(QZS) based Boost Full Bridge Isolated DC/DC Converter(BFBIC) topology as a basis power module and combination through input parallel output series(IPOS) method to improve power capacity and output voltage to match with the HVDC grid. The topology has both traditional voltage source and current source advantages, it permit the H-bridge short through and open circuit, which adopt utility duty cycle control and achieved input current and output voltage balancing through input current sharing control strategy. A ±10kV/200kW system model is built in MATLAB/SIMULINK to verify the proposed topology and control strategy.

Keywords: PV Generation System, Cascaded DC/DC converter, HVDC, Quasi Z Source Converter

Procedia PDF Downloads 370

Authors: Ankur P. Sati, Manju Mohan

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The hazardous combination of smoke and pollutant gases, smog, is harmful for health. There are strong evidences that the Agricultural waste burning (AWB) in the Northern India leads to adverse air quality in Delhi and its surrounding regions. A severe smog episode was observed over Delhi, India during November 2012 which resulted in very low visibility and various respiratory problems. Very high values of pollutants (PM10 as high as 989 µg m-3, PM2.5 as high as 585 µg m-3 an NO2 as high as 540 µg m-3) were measured all over Delhi during the smog episode. Ultra Violet Aerosol Index (UVAI) from Aura satellite and Aerosol Optical Depth (AOD) are used in the present study along with the output trajectories from HYSPLIT model and the in-situ data. Satellite data also reveal that AOD, UVAI are always at its highest during the farmfires duration in Punjab region of India and the extent of these farmfires may be increasing. It is observed that during the smog episode all the AOD, UVAI, PM2.5 and PM10 values surpassed those of the Diwali period (one of the most polluted events in the city) by a considerable amount at all stations across Delhi. The parameters used from the remote sensing data and the ground based observations at various stations across Delhi are very well in agreement about the intensity of Smog episode. The analysis clearly shows that regional pollution can have greater contributions in deteriorating the air quality than the local under adverse meteorological conditions.

Keywords: smog, farmfires, AOD, remote sensing

Procedia PDF Downloads 223

Authors: Tempe S. F. Adams, Michael J. Chase, Tracey L. Rogers, Keith E. A. Leggett

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Transfrontier wildlife corridors can be successful conservation tools, connecting protected areas and reducing the impact of habitat fragmentation on mobile species. Urban wildlife corridors have been proposed as a potential mitigation tool to facilitate the passage of elephants through towns without causing conflict with urban communities. However, because such corridors are typically narrow and close to human development, wildlife (particularly large mammals) may be less likely to use them. We used remote-sensor camera traps and global positioning system collars to identify the movement patterns of African elephants Loxondonta africana through narrow, urban corridors in Botswana. The corridors were in three types of human-dominated land-use designations with varying levels of human activity: agricultural, industrial and open space recreational land. We found that elephants used the corridors within all three land-use designations and we identified, using a model selection approach, that season, time of day and rainfall were important factors in determining the presence of elephants in the corridors. Elephants moved more slowly through the narrow corridors compared with their movement patterns through broader, wide-ranging corridors. Our results indicate that urban wildlife corridors are useful for facilitating elephants to pass through urban areas.

Keywords: camera traps, conservation, human-elephant coexistence, land management, urban wildlife corridors

Procedia PDF Downloads 282

Authors: Regina Chua

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To reduce the costs of re-fielding a large survey, a Random Forest classifier was applied to measure the accuracy of classifying individuals into their assigned segments with the fewest possible questions. Given a long survey, one needed to determine the most predictive ten or fewer questions that would accurately assign new individuals to custom segments. Furthermore, the solution needed to be quick in its classification and usable in non-Python environments. In this paper, a supervised Random Forest classifier was modeled on a dataset with 7,000 individuals, 60 questions, and 254 features. The Random Forest consisted of an iterative collection of individual decision trees that result in a predicted segment with robust precision and recall scores compared to a single tree. A random 70-30 stratified sampling for training the algorithm was used, and accuracy trade-offs at different depths for each segment were identified. Ultimately, the Random Forest classifier performed at 87% accuracy at a depth of 10 with 20 instead of 254 features and 10 instead of 60 questions. With an acceptable accuracy in prioritizing feature selection, new tools were developed for non-Python environments: a worksheet with a formulaic version of the algorithm and an embedded function to predict the segment of an individual in real-time. Random Forest was determined to be an optimal classification model by its feature selection, performance, processing speed, and flexible application in other environments.

Keywords: machine learning, supervised learning, data science, random forest, classification, prediction, predictive modeling

Procedia PDF Downloads 75

Authors: Haowen Xi

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We propose and solve exactly a class of non-linear generalization of the Black-Scholes process of stochastic differential equations describing price bubble and crashes dynamics. As a result of nonlinear positive feedback, the faster-than-exponential price positive growth (bubble forming) and negative price growth (crash forming) are found to be the power-law finite-time singularity in which bubbles and crashes price formation ending at finite critical time tc. While most literature on the market bubble and crash process focuses on the nonlinear positive feedback mechanism aspect, very few studies concern the noise level on the same process. The present work adds to the market bubble and crashes literature by studying the external sources noise influence on the critical time tc of the bubble forming and crashes forming. Two main results will be discussed: (1) the analytical expression of expected value of the critical time is found and unexpected critical slowing down due to the coupling external noise is predicted; (2) numerical simulations of the nonlinear stochastic equation is presented, and the probability distribution of Prob(tc) is found to be the inverse gamma function.

Keywords: bubble, crash, finite-time-singular, numerical simulation, price dynamics, stochastic differential equations

Procedia PDF Downloads 110

Authors: Rupam Saikia, Ashim Kanti Dey

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Sonapur is an intense hilly region on the border of Assam and Meghalaya lying in North-East India and is very near to a seismic fault named as Dauki besides which makes the region seismically active. Besides, these recently two earthquakes of magnitude 6.7 and 6.9 have struck North-East India in January and April 2016. Also, the slope concerned for this study is adjacent to NH 44 which for a long time has been a sole important connecting link to the states of Manipur and Mizoram along with some parts of Assam and so has been a cause of considerable loss to life and property since past decades as there has been several recorded incidents of landslide, road-blocks, etc. mostly during the rainy season which comes into news. Based on this issue this paper reports a static and dynamic slope stability analysis of Sonapur which has been carried out in MIDAS GTS NX. The slope being highly unreachable due to terrain and thick vegetation in-situ test was not feasible considering the current scope available so disturbed soil sample was collected from the site for the determination of strength parameters. The strength parameters were so determined for varying relative density with further variation in water content. The slopes were analyzed considering plane strain condition for three slope heights of 5 m, 10 m and 20 m which were then further categorized based on slope angles 30, 40, 50, 60, and 70 considering the possible extent of steepness. Initially static analysis under dry state was performed then considering the worst case that can develop during rainy season the slopes were analyzed for fully saturated condition along with partial degree of saturation with an increase in the waterfront. Furthermore, dynamic analysis was performed considering the El-Centro Earthquake which had a magnitude of 6.7 and peak ground acceleration of 0.3569g at 2.14 sec for the slope which were found to be safe during static analysis under both dry and fully saturated condition. Some of the conclusions were slopes with inclination above 40 onwards were found to be highly vulnerable for slopes of height 10 m and above even under dry static condition. Maximum horizontal displacement showed an exponential increase with an increase in inclination from 30 to 70. The vulnerability of the slopes was seen to be further increased during rainy season as even slopes of minimal steepness of 30 for height 20 m was seen to be on the verge of failure. Also, during dynamic analysis slopes safe during static analysis were found to be highly vulnerable. Lastly, as a part of the study a comparative study on Strength Reduction Method (SRM) versus Limit Equilibrium Method (LEM) was also carried out and some of the advantages and disadvantages were figured out.

Keywords: dynamic analysis, factor of safety, slope stability, strength reduction method

Procedia PDF Downloads 246

Authors: Rachit Marwaha, Rahul Dev Gupta, Vivek Jain, Krishan Kant Sharma

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Metal matrix hybrid composites (MMHCs) are now gaining their usage in aerospace, automotive and other industries because of their inherent properties like high strength to weight ratio, hardness and wear resistance, good creep behaviour, light weight, design flexibility and low wear rate etc. Al alloy base matrix reinforced with silicon carbide (10%) and graphite (5%) particles was fabricated by stir casting process. The wear and frictional properties of metal matrix hybrid composites were studied by performing dry sliding wear test using pin on disc wear test apparatus. Experiments were conducted based on the plan of experiments generated through Taguchi’s technique. A L9 Orthogonal array was selected for analysis of data. Investigation to find the influence of applied load, sliding speed and track diameter on wear rate as well as coefficient of friction during wearing process was carried out using ANOVA. Objective of the model was chosen as smaller the better characteristics to analyse the dry sliding wear resistance. Results show that track diameter has highest influence followed by load and sliding speed.

Keywords: Taguchi method, orthogonal array, ANOVA, metal matrix hybrid composites

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Authors: Pei-Ying Lo, Jing-Hao Ciou, Kai-Cheng Yang, Jia-Huei Zheng, Shih-Hsiang Huang, Kuen-Chan Lee, Er-Chieh Cho

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As-produced CNTs are insoluble in all organic solvents and aqueous solutions have imposed limitations to the use of CNTs. Therefore, how to debundle carbon nanotubes and to modify them for further uses is an important issue. There are several methods for the dispersion of CNTs in water using covalent attachment of hydrophilic groups to the surface of tubes. These methods, however, alter the electronic structure of the nanotubes by disrupting the network of sp2 hybridized carbons. In order to keep the nanotubes’ intrinsic mechanical and electrical properties intact, non-covalent interactions are increasingly being explored as an alternative route for dispersion. Apart from conventional surfactants such as sodium dodecylsulfate (SDS) or sodium dodecylbenzenesulfonate (SDBS) which are highly effective in dispersing CNTs, biopolymers have received much attention as dispersing agents due to the anticipated biocompatibility of the dispersed CNTs. Also, The pyrenyl group is known to interact strongly with the basal plane of graphene via π-stacking. In this study, a highly re-dispersible biopolymer is reported for the synthesis of pyrene-modified poly-L-lysine (PBPL) and poly(D-Glu, D-Lys) (PGLP). To provide the evidence of the safety of the PBPL/CNT & PGLP/CNT materials we use in this study, H1299 and HCT116 cells were incubated with PBPL/CNT & PGLP/CNT materials for toxicity analysis, MTS assays. The results from MTS assays indicated that no significant cellular toxicity was shown in H1299 and HCT116 cells. Furthermore, the fluorescence marker fluorescein isothiocyanate (FITC) was added to PBPL & PGLP dispersions. From the fluorescent measurements showed that the chemical functionalisation of the PBPL/CNT & PGLP/CNT conjugates with the fluorescence marker were successful. The fluorescent PBPL/CNT & PGLP/CNT conjugates could find application in medical imaging. In the next step, the GFP gene is immobilized onto PBPL/CNT conjugates by introducing electrostatic interaction. GFP-transfected cells that emitted fluorescence were imaged and counted under a fluorescence microscope. Due to the unique biocompatibility of PBPL modified CNTs, the GFP gene could be transported into H1299 cells without using antibodies. The applicability of such soluble and chemically functionalised polypeptide/CNT conjugates in biomedicine is currently investigated. We expect that this polypeptide/CNT system will be a safe and multi-functional nanomedical delivery platform and contribute to future medical therapy.

Keywords: carbon nanotube, nanotoxicology, GFP transfection, polypeptide/CNT hybrids

Procedia PDF Downloads 323

Authors: Qin Zhu

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Under the development concept of Park City, Tianfu Greenway system, as the basic and pre-configuration element of Chengdu Global Park construction, connects urban open space with linear and circular structures and undertakes and exerts the ecological, cultural and recreational functions of the park system. Chengdu greenway construction is in full swing. In the process of greenway planning and construction, the landscape effect of greenway on urban quality improvement is more valued, and the long-term impact of crowd experience on the sustainable development of greenway is often ignored. Therefore, it is very important to test the effectiveness of greenway construction from the perspective of users. Taking Jincheng Greenway in Chengdu as an example, this paper attempts to introduce multi-source data to construct a post-occupancy evaluation model of greenway and adopts behavior mapping method, questionnaire survey method, web text analysis and IPA analysis method to comprehensively evaluate the user 's behavior characteristics and satisfaction. According to the evaluation results, we can grasp the actual behavior rules and comprehensive needs of users so that the experience of building greenways can be fed back in time and provide guidance for the optimization and improvement of built greenways and the planning and construction of future greenways.

Keywords: multi-source data, greenway, IPA analysis, post -occupancy evaluation (POE)

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Authors: Sanaa Bardaweel

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Inorganic polyphosphate (poly P) is present in all living forms tested to date, from each of the three kingdoms of life. Studied mainly in prokaryotes, poly P and its associated enzymes are vital in diverse basic metabolism, in at least some structural functions and, notably, in stress responses. These plentiful and unrelated roles for poly P are probably the consequence of its presence in life-forms early in evolution. The genomes of many bacterial species, including pathogens, encode a homologue of a major poly P synthetic enzyme, poly P kinase 1 (PPK1). Genetic deletion of ppk1 results in reduced poly P levels and loss of pathogens virulence towards protozoa and animals. Thus far, no PPK1 homologue has been identified in higher-order eukaryotes and, therefore, PPK1 represents a novel target for chemotherapy. The idea of the current study is to purify the PPK1 from Escherichia coli to homogeneity in order to study the effect of active site point mutations on PPK1 catalysis via the application of site-directed mutagenesis strategy. The knowledge obtained about the active site of PPK1 will be utilized to characterize the catalytic and kinetic mechanism of PPK1 with model substrates. Comprehensive understanding of the enzyme kinetic mechanism and catalysis will be used to design and screen a library of synthetic compounds for potential discovery of selective PPK1-inhibitors.

Keywords: antimicobial, Escherichia coli, inorganic polyphosphate, PPK1-inhibitors

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Authors: Joseph Paul Chunga

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The investment universe is awash with a myriad of financial choices that investors have to opt for, which principally culminates into a duality between aggressive or conservative approaches. Howbeit, it is pertinent to emphasize that the investment vehicles with an aggressive approach tend to take on more risk than the latter group in an effort to generate higher future returns for their respective investors. This study examines the conditionality effect that such partiality in financing has on the High-Tech and Public Utility companies listed on the Shenzhen Stock Exchange (SSE). Specifically, it examines the significance of the relationship between capitalization ratios of Total Debt Ratio (TDR), Degree of Financial Leverage (DFL) and profitability ratios of Earnings per Share (EPS) and Returns on Equity (ROE) on the Financial Risk of the two industries. We employ a modified version of the Panel Regression Model used by Rahman (2017) to estimate the relationship. The study finds that there is a significant positive relationship between the capitalization ratios on the financial risk of Public Utility companies more than High-Tech companies and a substantial negative relationship between the profitability ratios and the financial risk of the former than the latter companies. This then spells an important insight for prospective investors with regards to the volatility of earnings of such companies.

Keywords: financial leverage, debt financing, conservative firms, aggressive firms

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Authors: Suarez-Puello Alejandro, Baquero-Ruiz Andrés F, Suarez-Puello Rodrigo

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This paper discusses the results of a foresight exercise which analyzes Bogota’s fruit, vegetable and tuber supply chain strategy- described at the Food Supply and Security Master Plan (FSSMP)-to provide the inhabitants of Bogotá, Colombia, with basic food products at a fair price. The methodology consisted of using quantitative and qualitative foresight tools such as system dynamics and variable selection methods to better represent interactions among stakeholders and obtain more integral results that could shed light on this complex situation. At first, the Master Plan is an input to establish the objectives and scope of the exercise. Then, stakeholders and their relationships are identified. Later, system dynamics is used to model product, information and money flow along the fruit, vegetable and tuber supply chain. Two scenarios are presented, discussing actions by the public sector and the reactions that could be expected from the whole food supply system. Finally, these impacts are compared to the Food Supply and Security Master Plan’s objectives suggesting recommendations that could improve its execution. This foresight exercise performed at a governmental level is intended to promote the widen the use of foresight as an anticipatory, decision-making tool that offers solutions to complex problems.

Keywords: decision making, foresight, public policies, supply chain, system dynamics

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Authors: Mai Nguyen-Phuong-Mai

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This paper incorporates insight from various models, studies and disciplines to construct a framework called the Inverted Pyramid Model. It is argued that such a framework has several advantages: (1) it reduces the shortcomings of the problem-focused approach that dominates the mainstream theories of cross-cultural management. With contributing insight from neuroscience, it suggests that training in business cross-cultural awareness should start with potential synergy emerged from differences instead of the traditional approach that focuses on the liability of foreigners and negative consequences of cultural distance. (2) The framework supports a dynamic and holistic way of analyzing cultural diversity by analyzing four major cultural units (global, national, organizational and group culture). (3) The framework emphasizes the role of individuals –an aspect of culture that is often ignored or regarded as a non-issue in the traditional approach. It is based on the notion that people don’t do business with a country, but work (in)directly with a unique person. And it is at this individual level that culture is made, personally, dynamically, and contextually. Insight from neuroscience provides significant evidence that a person can develop a multicultural mind, confirm and contradict, follow and reshape a culture, even when (s)he was previously an outsider to this culture. With this insight, the paper proposes a revision of the old adage (Think global – Act local) and change it into Think global – Plan local – Act individual.

Keywords: static–dynamic paradigm, cultural diversity, multicultural mind, neuroscience

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Authors: Jakub Bartus

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In general, composite steel and concrete structures present an effective structural solution utilizing full potential of both materials. As they have a numerous advantages on the construction side, they can reduce greatly the overall cost of construction, which is the main objective of the last decade, highlighted by the current economic and social crisis. The study represents not only an analysis of composite beams’ behaviour having web openings but emphasizes the influence of these openings on the total strain distribution at the level of steel bottom flange as well. The major investigation was focused on a change of structural performance with respect to various layouts of openings. Examining this structural modification, an improvement of load carrying capacity of composite beams was a prime object. The study is devided into analytical and numerical part. The analytical part served as an initial step into the design process of composite beam samples, in which optimal dimensions and specific levels of utilization in individual stress states were taken into account. The numerical part covered description of imposed structural issue in a form of a finite element model (FEM) using strut and shell elements accounting for material non-linearities. As an outcome, a number of conclusions were drawn describing and explaining an effect of web opening presence on the structural performance of composite beams.

Keywords: composite beam, web opening, steel flange, totalstrain, finite element analysis

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Authors: Sasirin Srisomkiew, Sireewan Ratsadornasai, Tanomkwan Tipvong, Isariya Meesing

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Cassava is an important food source in the tropics and has recently gained attention as a potential source of biofuel that can replace limited fossil fuel sources. As a result, the demand for cassava production to support industries both within the country and abroad has increased. In Thailand, most farmers prefer to grow cassava in sandy and sandy loam areas where the soil has low natural fertility. Cassava is a tuber plant that has large roots to store food, resulting in the absorption of large amounts of nutrients from the soil, such as nitrogen, phosphorus, and potassium. Therefore, planting cassava in the same area for a long period causes soil erosion and decreases soil fertility. The loss of soil fertility affects the economy, society, and food and energy security of the country. Therefore, it is necessary to know the level of soil fertility and the amount of nutrients in the soil. To address this problem, this study applies geo-informatics technology and mathematical equations to assess erosion and soil fertility and to analyze factors affecting the amount of cassava production in Maha Sarakham Province. The results show that the area for cassava cultivation has increased in every district of Maha Sarakham Province between 2015-2022, with the total area increasing to 180,922 rai or 5.47% of the province’s total area during this period. Furthermore, it was found that it is possible to assess areas with soil erosion problems that had a moderate level of erosion in areas with high erosion rates ranging from 5-15 T/rai/year. Soil fertility assessment and information obtained from the soil nutrient map for 2015–2023 reveal that farmers in the area have improved the soil by adding chemical fertilizers along with organic fertilizers, such as manure and green manure, to increase the amount of nutrients in the soil. This is because the soil resources of Maha Sarakham Province mostly have relatively low agricultural potential due to the soil texture being sand and sandy loam. In this scenario, the ability to absorb nutrients is low, and the soil holds little water, so it is naturally low in fertility. Moreover, agricultural soil problems were found, including the presence of saline soil, sandy soil, and acidic soil, which is a serious restriction on land use because it affects the release of nutrients into the soil. The results of this study may be used as a guideline for managing soil resources and improving soil quality to prevent soil degradation problems that may occur in the future.

Keywords: Cassava, geoinformatics, soil erosion, soil fertility, land use change

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Authors: Christina Tay

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This paper investigates the impact of Information and Communication Technology (ICT) on bilateral trade in goods. Empirical analysis is performed on the United States and 34 partnering countries from 2000 to 2013. Our econometric model fits the data well, explaining 52% of the variation in trade flows for goods trade, 53.2% of the variation in trade flows for goods export and 48% of the variation in trade flows for goods import. For every 10% increase in fixed broadband Internet subscribers per 100 people increases, goods trade by 7.9% and for every 5% increase in fixed broadband Internet subscribers per 100 people, goods export increases by 11%. For every 1% increase in fixed telephone line penetration per 100 people, goods trade increases by 26.3%, goods export increases by 24.4% and goods import increases by 24.8%. For every 1% increase in mobile-cellular telephone subscriptions, goods trade decreases by 29.6% and goods export decreases by 27.1%, whilst for every 0.01% increase in mobile-cellular telephone subscriptions, goods import decreases by 34.3%. For every 1% increase in the percentage of population who used the Internet from any location in the last 12 months Internet, goods trade increases by 32.5%, goods export increases by 38.9%, goods import increases by 33%. All our trade determinants as well as our ICT variables have significances on goods exports for the US. We can also draw from our study that the US relies more rather heavily on ICT for its goods export compared to goods import.

Keywords: bilateral trade, fixed broadband, fixed telephone, goods trade, information and communicative technologies, Internet, mobile-cellular phone

Procedia PDF Downloads 264

Authors: Siti N. I. Mat Kamal, Othman Ibrahim, Mehrbakhsh Nilashi, Jafalizan M. Jali

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The use of digital forensics (DF) is nowadays essential for law enforcement agencies to identify analysis and interpret the digital information derived from digital sources. In Malaysia, the engagement of Malaysian Law Enforcement Agencies (MLEA) with this new technology is not evenly distributed. To investigate the factors influencing the adoption of DF in Malaysia law enforcement agencies’ operational environment, this study proposed the initial theoretical framework based on the integration of technology organization environment (TOE), institutional theory, and human organization technology (HOT) fit model. A questionnaire survey was conducted on selected law enforcement agencies in Malaysia to verify the validity of the initial integrated framework. Relative advantage, compatibility, coercive pressure, normative pressure, vendor support and perceived technical competence of technical staff were found as the influential factors on digital forensics adoption. In addition to the only moderator of this study (agency size), any significant moderating effect on the perceived technical competence and the decision to adopt digital forensics by Malaysian law enforcement agencies was found insignificant. Thus, these results indicated that the developed integrated framework provides an effective prediction of the digital forensics adoption by Malaysian law enforcement agencies.

Keywords: digital forensics, digital forensics adoption, digital information, law enforcement agency

Procedia PDF Downloads 125

Authors: Constance Kirker

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While there is general agreement that food itself can be beautiful, thousands of still-life masterpieces over the years attest to this, depicting the act of eating, actually placing food in one’s mouth and chewing is seemingly taboo. The environment created around consumption -dining rooms, linens, china, flowers- is consciously choreographed to provide a pleasing aesthetic experience. Yet artists, from Roman frescoes painters to contemporary photographers, create images from feasts to solitary subjects that rarely show food or drink touching lips, chewing, or swallowing. Of the countless paintings of the Last Supper, the food remains on the table. Rarely is Adam or Eve shown taking a bite of the apple, initiating Original Sin. In the few examples that do depict food-in-mouth, Goya’s Saturn Devouring His Son, or the ubiquitous photos of the “wedding smash” with brides and grooms pushing wedding cake into each other’s mouths, the images are seemingly intended to be particularly ugly or humorous in a distasteful way. This paper will explore theories that include the rules of etiquette, some determined hundreds of years ago and still followed today, that imply eating is a metaphor for gluttony, implicit sexuality of eating, the distortion of the face while eating and the simple practicality of the difficulty of an artist’s model maintaining a chewing position. If art is a reflection of society, what drives the universal impulse to hide this very human function?

Keywords: aesthetics, senses, taboo, consumption

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Authors: R. Mehta, M. Ghogomu, B. Schoel

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Reports appeared in 2020 about China detecting SARS-Cov-2 (Covid-19) on frozen meat, shrimp, and food packaging material. In this study, we examined the use of swabs for the detection of Covid-19 on meat samples, and chicken breast (CB) was used as a model. Methods: Heat inactivated SARS-Cov-2 virus (IV) from Microbiologics was loaded onto the CB, swabbing was done, and the recovered inactivated virus was subjected to the Machery & Nagel NucleoSpin RNAVirus kit for RNA isolation according to manufacturer's instructions. For RT-PCR, the IDT 2019-nCoV RUO Covid-19 test kit was used with the Taqman Fast Virus 1-step master mix. The limit of detection (LOD) of viral load recovered from the CB was determined under various conditions: first on frozen CB where the IV was introduced on a defined area, then on frozen CB, with IV spread-out, and finally, on thawed CB. Results: The lowest amount of IV which can be reliably detected on frozen CB was a load of 1,000 - 2,000 IV copies where the IV was loaded on one spot of about 1 square inch. Next, the IV was spread out over a whole frozen CB about 16 square inches. The IV could be recovered at a lowest load of 4,000 to 8,000 copies. Furthermore, the effects of temperature change on viral load recovery was investigated i.e., if raw unfrozen meat became contaminated and remains for 1 hour at 4°C or gets refrozen. The amount of IV recovered successfully from CB kept at 4°C and the refrozen CB was similar to the recovery gotten from loading the IV directly on the frozen CB. In conclusion, an assay using swabs was successfully established for the detection of SARS-Cov-2 on frozen or raw (unfrozen) CB with a minimal load of up to 8,000 copies spread over 16 square inches.

Keywords: assay, COVID-19, meat, SARS-Cov-2

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Authors: Ralph Barnes

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The internationalization and globalization of education are now a huge, multi-million dollar industry. The movement of international students across the globe has provided a rich vein of revenue for universities and institutions of higher learning to exploit and harvest. A concerted effort has been made by universities worldwide to court students from overseas, with some countries relying up to one-third of student fees, coming from international students. Australian universities and English Language Centres are coming under increased government scrutiny in respect to such areas as the academic progression of international students, management and understanding of student visa requirements and the design of higher education courses and effective assessment regimes. As such, universities and other higher education institutions are restructuring themselves more as service providers rather than as strictly education providers. In this paper, the high-touch, tailored academic model currently followed by some Australian educational institutions to support international students, is examined and challenged. Academic support services offered to international students need to be coordinated, sustained and reviewed regularly, in order to assess their effectiveness. Maintaining the delivery of high-quality educational programs and learning outcomes for this high income-generating student cohort is vital, in order to continue the successful academic and social engagement by international students across the Australian university and higher education landscape.

Keywords: ESL, engagement, tertiary, learning

Procedia PDF Downloads 183

Authors: Hosamuddin Hamza

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The major concept of 4D printing is self-folding under thermal and humidity changes. This concept relies on understanding how the microstructures of 3D-printed models can undergo spontaneous shape transformation under thermal and moisture changes. The transformation mechanism could be achieved by mixing, in a controllable pattern, a number of materials within the printed model, each with known strain/shrinkage properties. 4D printing has a strong potential to be applied in dentistry as the technology could produce dynamic and adaptable materials to be used as functional objects in the oral environment under the continuously changing thermal and humidity conditions. The motion criteria could override the undesired dimensional changes, thermal instability, polymerization shrinkage and microleakage. 4D printing could produce restorative materials being self-adjusted spontaneously without further intervention from the dentist or patient; that is, the materials could be capable of fixing its failed portions, compensating for some lost tooth structure, while avoiding microleakage or overhangs at the margins. In prosthetic dentistry, 4D printing could provide an option to manage the influence of bone and soft tissue imbalance during mastication (and at rest) with high predictability of the type/direction of forces. It can also produce materials with better fitting and retention characteristics than conventional or 3D-printed materials. Nevertheless, it is important to highlight that 4D-printed objects, having dynamic properties, could provide some cushion as they undergo self-folding compensating for any thermal changes or mechanical forces such as traumatic forces.

Keywords: functional material, self-folding material, 3D printing, 4D printing

Procedia PDF Downloads 453