Search results for: structure-directing agent
1288 Reconfigurable Consensus Achievement of Multi Agent Systems Subject to Actuator Faults in a Leaderless Architecture
Authors: F. Amirarfaei, K. Khorasani
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In this paper, reconfigurable consensus achievement of a team of agents with marginally stable linear dynamics and single input channel has been considered. The control algorithm is based on a first order linear protocol. After occurrence of a LOE fault in one of the actuators, using the imperfect information of the effectiveness of the actuators from fault detection and identification module, the control gain is redesigned in a way to still reach consensus. The idea is based on the modeling of change in effectiveness as change of Laplacian matrix. Then as special cases of this class of systems, a team of single integrators as well as double integrators are considered and their behavior subject to a LOE fault is considered. The well-known relative measurements consensus protocol is applied to a leaderless team of single integrator as well as double integrator systems, and Gersgorin disk theorem is employed to determine whether fault occurrence has an effect on system stability and team consensus achievement or not. The analyses show that loss of effectiveness fault in actuator(s) of integrator systems affects neither system stability nor consensus achievement.Keywords: multi-agent system, actuator fault, stability analysis, consensus achievement
Procedia PDF Downloads 3371287 The Synthesis and Characterization of Highly Water-Soluble Silane Coupling Agents for Increasing Silica Filler Content in Styrene-Butadiene Rubber
Authors: Jun Choi, Bo Ram Lee, Ji Hye Choi, Jung Soo Kim, No-Hyung Park, Dong Hyun Kim
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The synthetic rubber compound, which is widely used as the core material for automobile tire industry, is manufactured by mixing styrene-butadiene rubber (SBR) and organic/inorganic fillers. It is known that the most important factor for the physical properties of rubber compound is the interaction between the filler and the rubber, which affects the rotational, braking and abrasion resistance. Silica filler has hydrophilic groups such as a silanol group on their surface which has a low affinity with hydrophobic rubbers. In order to solve this problem, researches on an efficient silane coupling agent (SCA) has been continuously carried out. In this study, highly water-soluble SCAs which are expected to show higher hydrolysis efficiency were synthesized. The hydrophobization process of the silica with the prepared SCAs was economical and environment-friendly. The SCAs structures were analysed by gas chromatography-mass spectrometry (GC/MS) and nuclear magnetic resonance (1H-NMR) spectroscopy. In addition, their hydrolysis efficiency and condensation side reaction in SBR wet master batch were examined by Fourier transform infrared spectroscopy (FT-IR) and gel permeation chromatography (GPC), respectively.Keywords: rubber, silane coupling agent, synthesis, water-soluble
Procedia PDF Downloads 2931286 Evaluation of the Integration of a Direct Reduction Process into an Existing Steel Mill
Authors: Nils Mueller, Gregor Herz, Erik Reichelt, Matthias Jahn
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In the context of climate change, the reduction of greenhouse gas emissions in all economic sectors is considered to be an important factor in order to meet the demands of a sustainable energy system. The steel industry as one of the large industrial CO₂ emitters is currently highly dependent on fossil resources. In order to reduce coke consumption and thereby CO₂ emissions while still being able to further utilize existing blast furnaces, the possibility of including a direct reduction process (DRP) into a fully integrated steel mill was investigated. Therefore, a blast furnace model, derived from literature data and implemented in Aspen Plus, was used to analyze the impact of DRI in the blast furnace process. Furthermore, a state-of-the-art DRP was modeled to investigate the possibility of substituting the reducing agent natural gas with hydrogen. A sensitivity analysis was carried out in order to find the boundary percentage of hydrogen as a reducing agent without penalty to the DRI quality. Lastly, the two modeled process steps were combined to form a route of producing pig iron. By varying boundary conditions of the DRP while recording the CO₂ emissions of the two process steps, the overall potential for the reduction of CO₂ emissions was estimated. Within the simulated range, a maximum reduction of CO₂ emissions of 23.5% relative to typical emissions of a blast furnace could be determined.Keywords: blast furnace, CO₂ mitigation, DRI, hydrogen
Procedia PDF Downloads 2841285 Smart Demand Response: A South African Pragmatic, Non-Destructive and Alternative Advanced Metering Infrastructure-Based Maximum Demand Reduction Methodology
Authors: Christo Nicholls
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The National Electricity Grid (NEG) in South Africa has been under strain for the last five years. This overburden of the NEG led Eskom (the State-Owned Entity responsible for the NEG) to implement a blunt methodology to assist them in reducing the maximum demand (MD) on the NEG, when required, called Loadshedding. The challenge of this methodology is that not only does it lead to immense technical issues with the distribution network equipment, e.g., transformers, due to the frequent abrupt off and on switching, it also has a broader negative fiscal impact on the distributors, as their key consumers (commercial & industrial) are now grid defecting due to the lack of Electricity Security Provision (ESP). This paper provides a pragmatic alternative methodology utilizing specific functionalities embedded within direct-connect single and three-phase Advanced Meter Infrastructure (AMI) Solutions deployed within the distribution network, in conjunction with a Multi-Agent Systems Based AI implementation focused on Automated Negotiation Peer-2-Peer trading. The results of this research clearly illustrate, not only does methodology provide a factual percentage contribution towards the NEG MD at the point of consideration, it also allows the distributor to leverage the real-time MD data from key consumers to activate complex, yet impact-measurable Demand Response (DR) programs.Keywords: AI, AMI, demand response, multi-agent
Procedia PDF Downloads 1121284 Preparation, Characterisation, and Antibacterial Activity of Green-Biosynthesised Silver Nanoparticles Using Clinacanthus Nutans Extract
Authors: Salahaedin Waiezi, Nik Ahmad Nizam Nik Malek, Hassan Abdelmagid Elzamzami, Shahrulnizahana Mohammad Din
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A green and safe approach to the synthesis of silver nanoparticles (AgNP) can be performed using plant leaf extract as the reducing agent. Hence, this paper reports the biosynthesis of AgNP using Clinacanthus nutans plant extract. C. nutans is known as belalai gajah in Malaysia and is widely used as a medicinal herb locally. The biosynthesized AgNP, using C. nutans aqueous extract at pH 10, with the reaction temperature of 70°C and 48 h reaction time, was characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), and transmission electron microscope (TEM). A peak appeared in the UV-Vis spectra at around 400 nm, while XRD confirmed the crystal structure of AgNP, with the average size between 20 to 30 nm, as shown in FESEM and TEM. The antibacterial activity of the biosynthesized AgNP, which was performed using the disc diffusion technique (DDT) indicated effective inhibition against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. In contrast, minimal antibacterial activity was detected against Enterococcus faecalis and methicillin-resistant Staphylococcus aureus (MRSA). In general, AgNP produced using C. nutans leaf extract possesses potential antibacterial activity.Keywords: silver nanoparticles, Clinacanthus nutans, antibacterial agent, biosynthesis
Procedia PDF Downloads 2041283 Effect of Surface-Modification of Indium Tin Oxide Particles on Their Electrical Conductivity
Authors: Y. Kobayashi, T. Kurosaka, K. Yamamura, T. Yonezawa, K. Yamasaki
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The present work reports an effect of surface- modification of indium tin oxide (ITO) particles with chemicals on their electronic conductivity properties. Examined chemicals were polyvinyl alcohol (nonionic polymer), poly(diallyl dimethyl ammonium chloride) (cationic polymer), poly(sodium 4-styrene-sulfonate) (anionic polymer), (2-aminopropyl) trimethoxy silane (APMS) (silane coupling agent with amino group), and (3-mercaptopropyl) trimethoxy silane (MPS) (silane coupling agent with thiol group). For all the examined chemicals, volume resistivities of surface-modified ITO particles did not increase much when they were aged in air at 80 oC, compared to a volume resistivity of un-surface-modified ITO particles. Increases in volume resistivities of ITO particles surface-modified with the silane coupling agents were smaller than those with the polymers, since hydrolysis of the silane coupling agents and condensation of generated silanol and OH groups on ITO particles took place to provide efficient immobilization of them on particles. The APMS gave an increase in volume resistivity smaller than the MPS, since a larger solubility in water of APMS providing a larger amount of APMS immobilized on particles.Keywords: indium tin oxide, particles, surface-modification, volume resistivity
Procedia PDF Downloads 2531282 A Validated UPLC-MS/MS Assay Using Negative Ionization Mode for High-Throughput Determination of Pomalidomide in Rat Plasma
Authors: Muzaffar Iqbal, Essam Ezzeldin, Khalid A. Al-Rashood
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Pomalidomide is a second generation oral immunomodulatory agent, being used for the treatment of multiple myeloma in patients with disease refractory to lenalidomide and bortezomib. In this study, a sensitive UPLC-MS/MS assay was developed and validated for high-throughput determination of pomalidomide in rat plasma using celecoxib as an internal standard (IS). Liquid liquid extraction using dichloromethane as extracting agent was employed to extract pomalidomide and IS from 200 µL of plasma. Chromatographic separation was carried on Acquity BEHTM C18 column (50 × 2.1 mm, 1.7 µm) using an isocratic mobile phase of acetonitrile:10 mM ammonium acetate (80:20, v/v), at a flow rate of 0.250 mL/min. Both pomalidomide and IS were eluted at 0.66 ± 0.03 and 0.80 ± 0.03 min, respectively with a total run time of 1.5 min only. Detection was performed on a triple quadrupole tandem mass spectrometer using electrospray ionization in negative mode. The precursor to product ion transitions of m/z 272.01 → 160.89 for pomalidomide and m/z 380.08 → 316.01 for IS were used to quantify them respectively, using multiple reaction monitoring mode. The developed method was validated according to regulatory guideline for bioanalytical method validation. The linearity in plasma sample was achieved in the concentration range of 0.47–400 ng/mL (r2 ≥ 0.997). The intra and inter-day precision values were ≤ 11.1% (RSD, %) whereas accuracy values ranged from - 6.8 – 8.5% (RE, %). In addition, other validation results were within the acceptance criteria and the method was successfully applied in a pharmacokinetic study of pomalidomide in rats.Keywords: pomalidomide, pharmacokinetics, LC-MS/MS, celecoxib
Procedia PDF Downloads 3911281 Surviral: An Agent-Based Simulation Framework for Sars-Cov-2 Outcome Prediction
Authors: Sabrina Neururer, Marco Schweitzer, Werner Hackl, Bernhard Tilg, Patrick Raudaschl, Andreas Huber, Bernhard Pfeifer
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History and the current outbreak of Covid-19 have shown the deadly potential of infectious diseases. However, infectious diseases also have a serious impact on areas other than health and healthcare, such as the economy or social life. These areas are strongly codependent. Therefore, disease control measures, such as social distancing, quarantines, curfews, or lockdowns, have to be adopted in a very considerate manner. Infectious disease modeling can support policy and decision-makers with adequate information regarding the dynamics of the pandemic and therefore assist in planning and enforcing appropriate measures that will prevent the healthcare system from collapsing. In this work, an agent-based simulation package named “survival” for simulating infectious diseases is presented. A special focus is put on SARS-Cov-2. The presented simulation package was used in Austria to model the SARS-Cov-2 outbreak from the beginning of 2020. Agent-based modeling is a relatively recent modeling approach. Since our world is getting more and more complex, the complexity of the underlying systems is also increasing. The development of tools and frameworks and increasing computational power advance the application of agent-based models. For parametrizing the presented model, different data sources, such as known infections, wastewater virus load, blood donor antibodies, circulating virus variants and the used capacity for hospitalization, as well as the availability of medical materials like ventilators, were integrated with a database system and used. The simulation result of the model was used for predicting the dynamics and the possible outcomes and was used by the health authorities to decide on the measures to be taken in order to control the pandemic situation. The survival package was implemented in the programming language Java and the analytics were performed with R Studio. During the first run in March 2020, the simulation showed that without measures other than individual personal behavior and appropriate medication, the death toll would have been about 27 million people worldwide within the first year. The model predicted the hospitalization rates (standard and intensive care) for Tyrol and South Tyrol with an accuracy of about 1.5% average error. They were calculated to provide 10-days forecasts. The state government and the hospitals were provided with the 10-days models to support their decision-making. This ensured that standard care was maintained for as long as possible without restrictions. Furthermore, various measures were estimated and thereafter enforced. Among other things, communities were quarantined based on the calculations while, in accordance with the calculations, the curfews for the entire population were reduced. With this framework, which is used in the national crisis team of the Austrian province of Tyrol, a very accurate model could be created on the federal state level as well as on the district and municipal level, which was able to provide decision-makers with a solid information basis. This framework can be transferred to various infectious diseases and thus can be used as a basis for future monitoring.Keywords: modelling, simulation, agent-based, SARS-Cov-2, COVID-19
Procedia PDF Downloads 1741280 Dynamic Capabilities and Disorganization: A Conceptual Exploration
Authors: Dinuka Herath, Shelley Harrington
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This paper prompts debate about whether disorganization can be positioned as a mechanism that facilitates the creation and enactment of important dynamic capabilities within an organization. This particular article is a conceptual exploration of the link between dynamic capabilities and disorganization and presents the case for agent-based modelling as a viable methodological tool which can be used to explore this link. Dynamic capabilities are those capabilities that an organization needs to sustain competitive advantage in complex environments. Disorganization is the process of breaking down restrictive organizational structures and routines that commonly reside in organizations in order to increase organizational performance. In the 20th century, disorganization was largely viewed as an undesirable phenomenon within an organization. However, the concept of disorganization has been revitalized and garnered research interest in the recent years due to studies which demonstrate some of the advantages of disorganization to an organization. Furthermore, recent Agent-based simulation studies have shown the capability of disorganization to be managed and argue for disorganization to be viewed as an enabler of organizational productivity. Given the natural state of disorganization and resulting fear this can create, this paper argues that instead of trying to ‘correct’ disorganization, it should be actively encouraged to have functional purpose. The study of dynamic capabilities emerged as a result of heightened dynamism and consequentially the very nature of dynamism denotes a level of fluidity and flexibility, something which this paper argues many organizations do not truly foster due to a constrained commitment to organization and order. We argue in this paper that the very state of disorganization is a state that should be encouraged to develop dynamic capabilities needed to not only deal with the complexities of the modern business environment but also to sustain competitive success. The significance of this paper stems from the fact that both dynamic capabilities and disorganization are two concepts that are gaining prominence in their respective academic genres. Despite the attention each concept has received individually, no conceptual link has been established to depict how they actually interact with each other. We argue that the link between these two concepts present a novel way of looking at organizational performance. By doing so, we explore the potential of these two concepts working in tandem in order to increase organizational productivity which has significant implications for both academics and practitioners alike.Keywords: agent-based modelling, disorganization, dynamic capabilities, performance
Procedia PDF Downloads 3171279 Combined Treatment of Estrogen-Receptor Positive Breast Microtumors with 4-Hydroxytamoxifen and Novel Non-Steroidal Diethyl Stilbestrol-Like Analog Produces Enhanced Preclinical Treatment Response and Decreased Drug Resistance
Authors: Sarah Crawford, Gerry Lesley
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This research is a pre-clinical assessment of anti-cancer effects of novel non-steroidal diethyl stilbestrol-like estrogen analogs in estrogen-receptor positive/ progesterone-receptor positive human breast cancer microtumors of MCF 7 cell line. Tamoxifen analog formulation (Tam A1) was used as a single agent or in combination with therapeutic concentrations of 4-hydroxytamoxifen, currently used as a long-term treatment for the prevention of breast cancer recurrence in women with estrogen receptor positive/ progesterone receptor positive malignancies. At concentrations ranging from 30-50 microM, Tam A1 induced microtumor disaggregation and cell death. Incremental cytotoxic effects correlated with increasing concentrations of Tam A1. Live tumor microscopy showed that microtumos displayed diffuse borders and substrate-attached cells were rounded-up and poorly adherent. A complete cytotoxic effect was observed using 40-50 microM Tam A1 with time course kinetics similar to 4-hydroxytamoxifen. Combined treatment with TamA1 (30-50 microM) and 4-hydroxytamoxifen (10-15 microM) induced a highly cytotoxic, synergistic combined treatment response that was more rapid and complete than using 4-hydroxytamoxifen as a single agent therapeutic. Microtumors completely dispersed or formed necrotic foci indicating a highly cytotoxic combined treatment response. Moreover, breast cancer microtumors treated with both 4-hydroxytamoxifen and Tam A1 displayed lower levels of long-term post-treatment regrowth, a critical parameter of primary drug resistance, than observed for 4-hydroxytamoxifen when used as a single agent therapeutic. Tumor regrowth at 6 weeks post-treatment with either single agent 4-hydroxy tamoxifen, Tam A1 or a combined treatment was assessed for the development of drug resistance. Breast cancer cells treated with both 4-hydroxytamoxifen and Tam A1 displayed significantly lower levels of post-treatment regrowth, indicative of decreased drug resistance, than observed for either single treatment modality. The preclinical data suggest that combined treatment involving the use of tamoxifen analogs may be a novel clinical approach for long-term maintenance therapy in patients with estrogen-receptor positive/progesterone-receptor positive breast cancer receiving hormonal therapy to prevent disease recurrence. Detailed data on time-course, IC50 and tumor regrowth assays post- treatment as well as a proposed mechanism of action to account for observed synergistic drug effects will be presented.Keywords: 4-hydroxytamoxifen, tamoxifen analog, drug-resistance, microtumors
Procedia PDF Downloads 681278 Optimizing Fire Suppression Time in Buildings by Forming a Fire Feedback Loop
Authors: Zhdanova A. O., Volkov R. S., Kuznetsov G. V., Strizhak P. A.
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Fires in different types of facilities are a serious problem worldwide.It is still an unaccomplished science and technology objective to establish the minimum number and type of sensors in automatic systems of compartment fire suppression which would turn the fire-extinguishing agent spraying on and off in real time depending on the state of the fire, minimize the amount of agent applied, delay time in fire suppression and system response, as well as the time of combustion suppression. Based on the results of experimental studies, the conclusion was made that it is reasonable to use a gas analysis system and heat sensors (in the event of their prior activation) to determine the effectiveness of fire suppression (fire-extinguishing composition interacts with the fire). Thus, the concentration of CO in the interaction of the firefighting liquid with the fire increases to 0.7–1.2%, which indicates a slowdown in the flame combustion, and heat sensors stop responding at a gas medium temperature below 80 ºC, which shows a gradual decrease in the heat release from the fire. The evidence from this study suggests that the information received from the video recording equipment (video camera) should be used in real time as an additional parameter confirming fire suppression. Research was supported by Russian Science Foundation (project No 21-19-00009, https://rscf.ru/en/project/21-19-00009/).Keywords: compartment fires, fire suppression, continuous control of fire behavior, feedback systems
Procedia PDF Downloads 1291277 A Multimodal Dialogue Management System for Achieving Natural Interaction with Embodied Conversational Agents
Authors: Ozge Nilay Yalcin
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Dialogue has been proposed to be the natural basis for the human-computer interaction, which is behaviorally rich and includes different modalities such as gestures, posture changes, gaze, para-linguistic parameters and linguistic context. However, equipping the system with these capabilities might have consequences on the usability of the system. One issue is to be able to find a good balance between rich behavior and fluent behavior, as planning and generating these behaviors is computationally expensive. In this work, we propose a multi-modal dialogue management system that automates the conversational flow from text-based dialogue examples and uses synchronized verbal and non-verbal conversational cues to achieve a fluent interaction. Our system is integrated with Smartbody behavior realizer to provide real-time interaction with embodied agent. The nonverbal behaviors are used according to turn-taking behavior, emotions, and personality of the user and linguistic analysis of the dialogue. The verbal behaviors are responsive to the emotional value of the utterance and the feedback from the user. Our system is aimed for online planning of these affective multi-modal components, in order to achieve enhanced user experience with richer and more natural interaction.Keywords: affect, embodied conversational agents, human-agent interaction, multimodal interaction, natural interfaces
Procedia PDF Downloads 1761276 Biotransformation Process for the Enhanced Production of the Pharmaceutical Agents Sakuranetin and Genkwanin: Poised to be Potent Therapeuctic Drugs
Authors: Niranjan Koirala, Sumangala Darsandhari, Hye Jin Jung, Jae Kyung Sohng
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Sakuranetin, an antifungal agent and genkwanin, an anti-inflammatory agent, are flavonoids with several potential pharmaceutical applications. To produce such valuable flavonoids in large quantity, an Escherichia coli cell factory has been created. E. coli harboring O-methyltransferase (SaOMT2) derived from Streptomyces avermitilis was employed for regiospecific methylation of naringenin and apigenin. In order to increase the production via biotransformation, metK gene was overexpressed and the conditions were optimized. The maximum yield of sakuranetin and genkwanin under optimized conditions was 197 µM and 170 µM respectively when 200 µM of naringenin and apigenin were supplemented in the separate cultures. Furthermore, sakuranetin was purified in large scale and used as a substrate for in vitro glycosylation by YjiC to produce glucose and galactose derivatives of sakuranetin for improved solubility. We also found that unlike naringenin, sakuranetin effectively inhibits α-melanocyte stimulating hormone (α-MSH)-stimulated melanogenesis in B16F10 melanoma cells. In addition, genkwanin more potently inhibited angiogenesis than apigenin. Based on our findings, we speculate that these compounds warrant further investigation in vivo as potential new therapeutic anti-carcinogenic, anti-melanogenic and anti-angiogenic agents.Keywords: anti-carcinogenic, anti-melanogenic, glycosylation, methylation
Procedia PDF Downloads 6091275 Effect of Natural Molecular Crowding on the Structure and Stability of DNA Duplex
Authors: Chaudhari S. G., Saxena, S.
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We systematically and quantitatively investigated the effect of glucose as a model of natural molecular crowding agent on the structure and thermodynamics of Watson-Crick base paired three duplexes (named as D1, D2 and D3) of different base compositions and lengths. Structural analyses demonstrated that duplexes (D1 and D2) folded into B-form with different cations in the absence and presence of glucose while duplex (D3) folded into mixed A and B-form. Moreover, we demonstrated that the duplex was more stable in the absence of glucose, and marginally destabilized in its presence because glucose act as a weak structure breaker on the tetrahedral network of water. In the absence of glucose, the values of ΔG°25 for duplex (D1) were -13.56, -13.76, -12.46, and -12.36 kcal/mol, for duplex (D2) were -13.64, -12.93, -12.86, and -12.30 kcal/mol, for duplex (D3) were -10.05, -11.76, -9.91, -9.70 kcal/mol in the presence of Na+, K+, Na+ + Mg++ and K+ + Mg++ respectively. At high concentration of glucose (1:10000), there was increase in ΔG°25 for duplex (D1) -12.47, -12.37, -11.96, -11.55 kcal/mol, for duplex (D2) -12.37, -11.47, -11.98, -11.01 kcal/mol and for duplex (D3) -8.47, -9.17, -9.16, -8.66 kcal/mol. Our results provide the information that structure and stability of DNA duplex depends on the structure of molecular crowding agent present in its close vicinity. In this study, I have taken the hydration of simple sugar as an essential model for understanding interactions between hydrophilic groups and interfacial water molecules and its effect on hydrogen bonded DNA duplexes. On the basis of these relatively simple building blocks I hope to gain some insights for understanding more generally the properties of sugar–water–salt systems with DNA duplexes.Keywords: natural molecular crowding, DNA Duplex, structure of DNA, bioengineering and life sciences
Procedia PDF Downloads 4661274 Travel Behavior Simulation of Bike-Sharing System Users in Kaoshiung City
Authors: Hong-Yi Lin, Feng-Tyan Lin
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In a Bike-sharing system (BSS), users can easily rent bikes from any station in the city for mid-range or short-range trips. BSS can also be integrated with other types of transport system, especially Green Transportation system, such as rail transport, bus etc. Since BSS records time and place of each pickup and return, the operational data can reflect more authentic and dynamic state of user behaviors. Furthermore, land uses around docking stations are highly associated with origins and destinations for the BSS users. As urban researchers, what concerns us more is to take BSS into consideration during the urban planning process and enhance the quality of urban life. This research focuses on the simulation of travel behavior of BSS users in Kaohsiung. First, rules of users’ behavior were derived by analyzing operational data and land use patterns nearby docking stations. Then, integrating with Monte Carlo method, these rules were embedded into a travel behavior simulation model, which was implemented by NetLogo, an agent-based modeling tool. The simulation model allows us to foresee the rent-return behaviour of BSS in order to choose potential locations of the docking stations. Also, it can provide insights and recommendations about planning and policies for the future BSS.Keywords: agent-based model, bike-sharing system, BSS operational data, simulation
Procedia PDF Downloads 3331273 Motherhood Practices and Symbolic Capital: A Study of Teen Mothers in Northeastern Thailand
Authors: Ampai Muensit, Maniemai Thongyou, Patcharin Lapanun
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Teen mothers have been viewed as ‘a powerless’ facing numerous pressures including poverty, immaturity of motherhood, and especially social blame.This paper argues that, to endure as an agent, they keep struggling to overcome all difficulties in their everyday life by using certain symbols to negotiate the situations they encounter, and to obtain a social position without surrendering to the dominating socio-cultural structure. Guided by Bourdieu’s theory of practice, this study looks at how teen mothers use symbolic capital in their motherhood practices. Although motherhood practices can be found in different contexts with various types of capital utilization, this paper focuses on the use of symbolic capitals in teen mothers’ practices within the contexts of the community. The study employs a qualitative methodology; data was collected from 12 informants through life history, in-depth interview, observation and the content analytical method was employed for data analysis. The findings show that child and motherhood were key symbolic capitals in motherhood practices. Employing such capitals teen mothers can achieve an acceptance from community – particularly from the new community. These symbolic capitals were the important sources of teen mothers’ power to turn the tide by changing their status – from “the powerless” to be “the agent”. The use of symbolic capitals also related to habitus of teen mothers in better compromising for an appropriate social position.Keywords: teen mother, motherhood practice, symbolic capital, community
Procedia PDF Downloads 2671272 Production, Quality Control, and Biodistribution Studies of 141ce-Edtmp as a Potential Bone Pain Palliation Agent
Authors: Fatemeh Soltani, Simindokht Shirvani Arani, Ali Bahrami Samani, Mahdi Sadeghi, Kamal Yavari
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Cerium-141 [T1/2 = 32.501 days, Eβ (max) = 0.580 (29.8%) and 0.435(70.2%) MeV, Eγ=145.44 (48.2%) keV] possesses radionuclidic properties suitable for use in palliative therapy of bone metastases. 141Ce also has gamma energy of 145.44 keV, which resembles that of 99mTc. Therefore, the energy window is adjustable on the Tc-99m energy because of imaging studies. 141Ce can be produced through a relatively easy route that involves thermal neutron bombardment on natural CeO2 in medium flux research reactors (4–5×1013 neutrons/cm2•s). The requirement for an enriched target does not arise. Ethylenediamine tetramethylene phosphonic acid (EDTMP) was synthesized and radiolabeled with 141Ce. Complexation parameters were optimized to achieve maximum yields (>99%). The radiochemical purity of 141Ce-EDTMP was evaluated by radio-thin layer chromatography. The stability of the prepared formulation was monitored for one week at room temperature, and results showed that the preparation was stable during this period (>99%). Biodistribution studies of the complexes carried out in wild-type rats exhibited significant bone uptake with rapid clearance from blood. The properties of produced 141Ce-EDTMP suggest applying a new efficient bone pain palliative therapeutic agent to overcome metastatic bone pains.Keywords: bone pain palliative, cerium-141, EDTMP, radiopharmaceutical
Procedia PDF Downloads 4891271 Passivization: as Syntactic Argument Decreasing Parameter in Boro
Authors: Ganga Brahma
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Boro employs verbs hooked up with morphemes which lead verbs to adjust with their arguments and hence, affecting the whole of sentence structures. This paper is based on few such syntactic parameters which are usually considered as argument decreasing parameters in linguistic works. Passivizing of few transitive clauses which are usually construed from the verbs occurring with certain morphemes and representation in middle constructions are few of such strategies which lead to conceptualizing of decreasing of syntactic arguments from a sentence. This paper focuses on the mentioned linguistic strategies and attempts to describe the linguistic processes as for how these parameters work in languages especially by concentrating on a particular Tibeto-Burman language i.e. Boro. Boro is a Tibeto-Burman language widely spoken in parts of the north-eastern regions of India. It has an agglutinative nature in forming words as well as clauses. There is a morpheme ‘za’ which means ‘to happen, become’ in Boro whose appearances with verb roots denotes an idea of the subject being passivized. Passivization, usually has notions that it is a reversed representation of its active sentence forms in the terms of argument placements. (However, it is not accountably true as passives and actives have some distinct features of their own and independent of one and the other.) This particular work will concentrate on the semantics of passivization at the same time along with its syntactic reality. The verb khɑo meaning ‘to steal’ offers a sense of passivization with the appearance of the morpheme zɑ which means ‘to happen, become’ (e.g Zunu-ɑ lama-ɑo phɯisɑ khɑo-zɑ-bɑi; Junu-NOM road-LOC money steal-PASS-PRES: Junu got her money stolen on the road). The focus, here, is more on the argument placed at the subject position (i.e. Zunu) and the event taken place. The semantics of such construction asks for the agent because without an agent the event could not have taken place. However, the syntactic elements fill the slots of relegated or temporarily deleted agent which, infact, is the actual subject cum agent in its active representation. Due to the event marker ‘zɑ’ in this presentation it affords to reduce one participant from such a situation which in actual is made up of three participants. Hence, the structure of di-transitive construction here reduces to mono-transitive structure. Unlike passivization, middle construction does not allow relegation of the agents. It permanently deletes agents. However, it also focuses on the fore-grounded subject and highlighting on the changed states on the subjects which happens to be the underlying objects of their respective transitive structures (with agents). This work intends to describe how these two parameters which are different at their semantic realization can meet together at a syntactic level in order to create a linguistic parameter that decreases participants from their actual structures which are with more than one participant.Keywords: argument-decrease, middle-construction, passivization, transitivity-intransitivity
Procedia PDF Downloads 2371270 An Inquiry into the Usage of Complex Systems Models to Examine the Effects of the Agent Interaction in a Political Economic Environment
Authors: Ujjwall Sai Sunder Uppuluri
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Group theory is a powerful tool that researchers can use to provide a structural foundation for their Agent Based Models. These Agent Based models are argued by this paper to be the future of the Social Science Disciplines. More specifically, researchers can use them to apply evolutionary theory to the study of complex social systems. This paper illustrates one such example of how theoretically an Agent Based Model can be formulated from the application of Group Theory, Systems Dynamics, and Evolutionary Biology to analyze the strategies pursued by states to mitigate risk and maximize usage of resources to achieve the objective of economic growth. This example can be applied to other social phenomena and this makes group theory so useful to the analysis of complex systems, because the theory provides the mathematical formulaic proof for validating the complex system models that researchers build and this will be discussed by the paper. The aim of this research, is to also provide researchers with a framework that can be used to model political entities such as states on a 3-dimensional plane. The x-axis representing resources (tangible and intangible) available to them, y the risks, and z the objective. There also exist other states with different constraints pursuing different strategies to climb the mountain. This mountain’s environment is made up of risks the state faces and resource endowments. This mountain is also layered in the sense that it has multiple peaks that must be overcome to reach the tallest peak. A state that sticks to a single strategy or pursues a strategy that is not conducive to the climbing of that specific peak it has reached is not able to continue advancement. To overcome the obstacle in the state’s path, it must innovate. Based on the definition of a group, we can categorize each state as being its own group. Each state is a closed system, one which is made up of micro level agents who have their own vectors and pursue strategies (actions) to achieve some sub objectives. The state also has an identity, the inverse being anarchy and/or inaction. Finally, the agents making up a state interact with each other through competition and collaboration to mitigate risks and achieve sub objectives that fall within the primary objective. Thus, researchers can categorize the state as an organism that reflects the sum of the output of the interactions pursued by agents at the micro level. When states compete, they employ a strategy and that state which has the better strategy (reflected by the strategies pursued by her parts) is able to out-compete her counterpart to acquire some resource, mitigate some risk or fulfil some objective. This paper will attempt to illustrate how group theory combined with evolutionary theory and systems dynamics can allow researchers to model the long run development, evolution, and growth of political entities through the use of a bottom up approach.Keywords: complex systems, evolutionary theory, group theory, international political economy
Procedia PDF Downloads 1391269 Preparation of Biomedical Hydrogels Using Phenolic Compounds and Electron Beam Irradiation
Authors: Farnaz Sadeghi, Moslem Tavakol
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In this study, an attempt has been made to prepare a physically cross-linked gel by cooling of tannic acid (TA)-polyvinyl alcohol (PVA) solution that subsequently convert to antibacterial chemically cross-linked hydrogel by using electron beam irradiation. PVA is known for its biocompatibility and hydrophilicity, and TA is known for being a natural compound which can serve as a cross-linking agent and a therapeutic agent. Swelling behavior, gel content, pore size, and mechanical properties of hydrogels which prepared at 14, 28, and 56 (kGy) with different ratios of polymers were investigated. PVA-TA hydrogel showed sustained release of tannic acid as approximately 20% and 50% of loaded TA released from the hydrogel after 4 and 72 h release time. We found that gel content decreased and the moisture retention capability increased by an increase in TA composition. In addition, PVA-TA hydrogels showed a good antibacterial activity against S.aureus. MTT analysis indicated that close to 83% of fibroblast cells remained viable after 48 h exposure to hydrogel extract. Moreover, the cooling of 10% PVA solution containing 0.5 and 0.75% w/v tannic acid to room and refrigerator, respectively, led to formation of physical gel that did not present any flow index after inversion of hydrogel cast. According to the results, the hydrogel prepared by electron beam irradiation of blended PVA-TA solution could be further investigated as a promising candidate for wound healing.Keywords: poly vinyl alcohol, tannic acid, electron beam irradiation, hydrogel wound dressing
Procedia PDF Downloads 1541268 The 6Rs of Radiobiology in Photodynamic Therapy: Review
Authors: Kave Moloudi, Heidi Abrahamse, Blassan P. George
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Radiotherapy (RT) and photodynamic therapy (PDT) are both forms of cancer treatment that aim to kill cancer cells while minimizing damage to healthy tissue. The similarity between RT and PDT lies in their mechanism of action. Both treatments use energy to damage cancer cells. RT uses high-energy radiation to damage the DNA of cancer cells, while PDT uses light energy to activate a photosensitizing agent, which produces reactive oxygen species (ROS) that damage the cancer cells. Both treatments require careful planning and monitoring to ensure the correct dose is delivered to the tumor while minimizing damage to surrounding healthy tissue. They are also often used in combination with other treatments, such as surgery or chemotherapy, to improve overall outcomes. However, there are also significant differences between RT and PDT. For example, RT is a non-invasive treatment that can be delivered externally or internally, while PDT requires the injection of a photosensitizing agent and the use of a specialized light source to activate it. Additionally, the side effects and risks associated with each treatment can vary. In this review, we focus on generalizing the 6Rs of radiobiology in PDT, which can open a window for the clinical application of Radio-photodynamic therapy with minimum side effects. Furthermore, this review can open new insight to work on and design new radio-photosensitizer agents in Radio-photodynamic therapy.Keywords: radiobiology, photodynamic therapy, radiotherapy, 6Rs in radiobiology, ROS, DNA damages, cellular and molecular mechanism, clinical application.
Procedia PDF Downloads 1021267 Microwave and Ultrasound Assisted Extraction of Pectin from Mandarin and Lemon Peel: Comparisons between Sources and Methods
Authors: Pınar Karbuz, A. Seyhun Kıpcak, Mehmet B. Piskin, Emek Derun, Nurcan Tugrul
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Pectin is a complex colloidal polysaccharide, found on the cell walls of all young plants such as fruit and vegetables. It acts as a thickening, stabilizing and gelling agent in foods. Pectin was extracted from mandarin and lemon peels using ultrasound and microwave assisted extraction methods to compare with these two different sources and methods of pectin production. In this work, the effect of microwave power (360, 600 W) and irradiation time (1, 2, 3 min) on the yield of extracted pectin from mandarin and lemon peels for microwave assisted extraction (MAE) were investigated. For ultrasound assisted extraction (UAE), parameters were determined as temperature (60, 75 °C) and sonication time (15, 30, 45 min) and hydrochloric acid (HCl) was used as an extracting agent for both extraction methods. The highest yields of extracted pectin from lemon peels were found to be 8.16 % (w/w) for 75 °C, 45 min by UAE and 8.58 % (w/w) for 360 W, 1 min by MAE. Additionally, the highest yields of extracted pectin from mandarin peels were found to be 11.29 % (w/w) for 75 °C, 45 min by UAE and 16.44 % (w/w) for 600 W, 1 min by MAE. The results showed that the use of microwave assisted extraction promoted a better yield when compared to the two extraction methods. On the other hand, according to the results of experiments, mandarin peels contain more pectin than lemon peels when the compared to the pectin product values of two sources. Therefore, these results suggested that MAE could be used as an efficient and rapid method for extraction of pectin and mandarin peels should be preferred as sources of pectin production compared to lemon peels.Keywords: mandarin peel, lemon peel, pectin, ultrasound, microwave, extraction
Procedia PDF Downloads 2341266 Determination of Foaming Behavior in Thermoplastic Composite Nonwoven Structures for Automotive Applications
Authors: Zulfiye Ahan, Mustafa Dogu, Elcin Yilmaz
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The use of nonwoven textile materials in many application areas is rapidly increasing thanks to their versatile performance properties. The automotive industry is one of the largest sectors in the world with a potential market of more than 2 billion euros for nonwoven textile materials applications. Lightweight materials having higher mechanical performance, better sound and heat insulation properties are of interest in many applications. Since the usage of nonwoven surfaces provides many of these advantages, the demand for this kind of materials is gradually growing especially in the automotive industry. Nonwoven materials used in lightweight vehicles can contain economical and high strength thermoplastics as well as durable components such as glass fiber. By bringing these composite materials into foam structure containing micro or nanopores, products with high absorption ability, light and mechanically stronger can be fabricated. In this respect, our goal is to produce thermoplastic composite nonwoven by using nonwoven glass fiber fabric reinforced polypropylene (PP). Azodicarbonamide (ADC) was selected as a foaming agent and a thermal process was applied to obtain porous structure. Various foaming temperature ranges and residence times were studied to examine the foaming behaviour of the thermoplastic composite nonwoven. Physicochemical and mechanical tests were applied in order to analyze the characteristics of composite foams.Keywords: composite nonwoven, thermoplastic foams, foaming agent, foaming behavior
Procedia PDF Downloads 2351265 Determination of Foaming Behavior in thermoplastic Composite Nonwoven Structures for Automotive Applications
Authors: Zulfiye Ahan, Mustafa Dogu, Elcin Yilmaz
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The use of nonwoven textile materials in many application areas is rapidly increasing thanks to their versatile performance properties. The automotive industry is one of the largest sectors in the world, with a potential market of more than 2 billion euros for nonwoven textile materials applications. Lightweight materials having higher mechanical performance, better sound and heat insulation properties are of interest in many applications. Since the usage of nonwoven surfaces provides many of these advantages, the demand for this kind of material is gradually growing, especially in the automotive industry. Nonwoven materials used in lightweight vehicles can contain economical and high strength thermoplastics as well as durable components such as glass fiber. By bringing these composite materials into foam structure containing micro or nanopores, products with high absorption ability, light and mechanically stronger can be fabricated. In this respect, our goal is to produce thermoplastic composite nonwoven by using nonwoven glass fiber fabric reinforced polypropylene (PP). Azodicarbonamide (ADC) was selected as a foaming agent, and a thermal process was applied to obtain a porous structure. Various foaming temperature ranges and residence times were studied to examine the foaming behaviour of the thermoplastic composite nonwoven. Physicochemical and mechanical tests were applied in order to analyze the characteristics of composite foams.Keywords: composite nonwoven, thermoplastic foams, foaming agent, foaming behavior
Procedia PDF Downloads 2381264 A Fast Parallel and Distributed Type-2 Fuzzy Algorithm Based on Cooperative Mobile Agents Model for High Performance Image Processing
Authors: Fatéma Zahra Benchara, Mohamed Youssfi, Omar Bouattane, Hassan Ouajji, Mohamed Ouadi Bensalah
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The aim of this paper is to present a distributed implementation of the Type-2 Fuzzy algorithm in a parallel and distributed computing environment based on mobile agents. The proposed algorithm is assigned to be implemented on a SPMD (Single Program Multiple Data) architecture which is based on cooperative mobile agents as AVPE (Agent Virtual Processing Element) model in order to improve the processing resources needed for performing the big data image segmentation. In this work we focused on the application of this algorithm in order to process the big data MRI (Magnetic Resonance Images) image of size (n x m). It is encapsulated on the Mobile agent team leader in order to be split into (m x n) pixels one per AVPE. Each AVPE perform and exchange the segmentation results and maintain asynchronous communication with their team leader until the convergence of this algorithm. Some interesting experimental results are obtained in terms of accuracy and efficiency analysis of the proposed implementation, thanks to the mobile agents several interesting skills introduced in this distributed computational model.Keywords: distributed type-2 fuzzy algorithm, image processing, mobile agents, parallel and distributed computing
Procedia PDF Downloads 4291263 Analysis of Complex Business Negotiations: Contributions from Agency-Theory
Authors: Jan Van Uden
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The paper reviews classical agency-theory and its contributions to the analysis of complex business negotiations and gives an approach for the modification of the basic agency-model in order to examine the negotiation specific dimensions of agency-problems. By illustrating fundamental potentials for the modification of agency-theory in context of business negotiations the paper highlights recent empirical research that investigates agent-based negotiations and inter-team constellations. A general theoretical analysis of complex negotiation would be based on a two-level approach. First, the modification of the basic agency-model in order to illustrate the organizational context of business negotiations (i.e., multi-agent issues, common-agencies, multi-period models and the concept of bounded rationality). Second, the application of the modified agency-model on complex business negotiations to identify agency-problems and relating areas of risk in the negotiation process. The paper is placed on the first level of analysis – the modification. The method builds on the one hand on insights from behavior decision research (BRD) and on the other hand on findings from agency-theory as normative directives to the modification of the basic model. Through neoclassical assumptions concerning the fundamental aspects of agency-relationships in business negotiations (i.e., asymmetric information, self-interest, risk preferences and conflict of interests), agency-theory helps to draw solutions on stated worst-case-scenarios taken from the daily negotiation routine. As agency-theory is the only universal approach able to identify trade-offs between certain aspects of economic cooperation, insights obtained provide a deeper understanding of the forces that shape business negotiation complexity. The need for a modification of the basic model is illustrated by highlighting selected issues of business negotiations from agency-theory perspective: Negotiation Teams require a multi-agent approach under the condition that often decision-makers as superior-agents are part of the team. The diversity of competences and decision-making authority is a phenomenon that overrides the assumptions of classical agency-theory and varies greatly in context of certain forms of business negotiations. Further, the basic model is bound to dyadic relationships preceded by the delegation of decision-making authority and builds on a contractual created (vertical) hierarchy. As a result, horizontal dynamics within the negotiation team playing an important role for negotiation success are therefore not considered in the investigation of agency-problems. Also, the trade-off between short-term relationships within the negotiation sphere and the long-term relationships of the corporate sphere calls for a multi-period perspective taking into account the sphere-specific governance-mechanisms already established (i.e., reward and monitoring systems). Within the analysis, the implementation of bounded rationality is closely related to findings from BRD to assess the impact of negotiation behavior on underlying principal-agent-relationships. As empirical findings show, the disclosure and reservation of information to the agent affect his negotiation behavior as well as final negotiation outcomes. Last, in context of business negotiations, asymmetric information is often intended by decision-makers acting as superior-agents or principals which calls for a bilateral risk-approach to agency-relations.Keywords: business negotiations, agency-theory, negotiation analysis, interteam negotiations
Procedia PDF Downloads 1391262 Agent-Based Modeling Investigating Self-Organization in Open, Non-equilibrium Thermodynamic Systems
Authors: Georgi Y. Georgiev, Matthew Brouillet
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This research applies the power of agent-based modeling to a pivotal question at the intersection of biology, computer science, physics, and complex systems theory about the self-organization processes in open, complex, non-equilibrium thermodynamic systems. Central to this investigation is the principle of Maximum Entropy Production (MEP). This principle suggests that such systems evolve toward states that optimize entropy production, leading to the formation of structured environments. It is hypothesized that guided by the least action principle, open thermodynamic systems identify and follow the shortest paths to transmit energy and matter, resulting in maximal entropy production, internal structure formation, and a decrease in internal entropy. Concurrently, it is predicted that there will be an increase in system information as more information is required to describe the developing structure. To test this, an agent-based model is developed simulating an ant colony's formation of a path between a food source and its nest. Utilizing the Netlogo software for modeling and Python for data analysis and visualization, self-organization is quantified by calculating the decrease in system entropy based on the potential states and distribution of the ants within the simulated environment. External entropy production is also evaluated for information increase and efficiency improvements in the system's action. Simulations demonstrated that the system begins at maximal entropy, which decreases as the ants form paths over time. A range of system behaviors contingent upon the number of ants are observed. Notably, no path formation occurred with fewer than five ants, whereas clear paths were established by 200 ants, and saturation of path formation and entropy state was reached at populations exceeding 1000 ants. This analytical approach identified the inflection point marking the transition from disorder to order and computed the slope at this point. Combined with extrapolation to the final path entropy, these parameters yield important insights into the eventual entropy state of the system and the timeframe for its establishment, enabling the estimation of the self-organization rate. This study provides a novel perspective on the exploration of self-organization in thermodynamic systems, establishing a correlation between internal entropy decrease rate and external entropy production rate. Moreover, it presents a flexible framework for assessing the impact of external factors like changes in world size, path obstacles, and friction. Overall, this research offers a robust, replicable model for studying self-organization processes in any open thermodynamic system. As such, it provides a foundation for further in-depth exploration of the complex behaviors of these systems and contributes to the development of more efficient self-organizing systems across various scientific fields.Keywords: complexity, self-organization, agent based modelling, efficiency
Procedia PDF Downloads 681261 Natural Honey and Effect on the Activity of the Cells
Authors: Abujnah Dukali
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Natural honey was assessed in cell culture system for its anticancer activity. Human leukemic cell line HL 60 was treated with honey and cultured for 5 days and cytotoxicity was calculated by MTT assay. Honey showed cytotoxicity with CC50 value of 174.20 µg/ml. Radical modulation activities was assessed by lipid peroxidation assay using egg lecithin. Honey showed antioxidant activity with EC50 value of 159.73 µg/ml. In addition, treatment with HL60 cells also resulted in nuclear DNA fragmentation, as seen in agarose gel electrophoresis. This is a hallmark of cells undergoing apoptosis. Confirmation of apoptosis was performed by staining the cells with Annexin V and FACS analysis. Apoptosis is an active, genetically regulated disassembly of the cell form within. Disassembly creates changes in the phospholipid content of the cytoplasmic membrane outer leaflet. Phosphatidylserine (PS) is translocated from the inner to the outer surface of the cell for phagocytic cell recognition. The human anticoagulant, annexin V, is a Ca2+-dependent phospholipid protein with a high affinity for PS. Annexin V labeled with fluorescein can identify apoptotic cells in the population It is a confirmatory test for apoptosis. Annexin V-positive cells were defined as apoptotic cells. Since honey shows both antioxidant activity and cytotoxicity at almost the same concentration, it can prevent the free radical induced cancer as prophylactic agent and kill the cancer cells by apoptotic process as a chemotherapeutic agent. Everyday intake of honey can prevent the cancer induction.Keywords: anticancer, cells, DNA, honey
Procedia PDF Downloads 2061260 Deep Reinforcement Learning Approach for Optimal Control of Industrial Smart Grids
Authors: Niklas Panten, Eberhard Abele
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This paper presents a novel approach for real-time and near-optimal control of industrial smart grids by deep reinforcement learning (DRL). To achieve highly energy-efficient factory systems, the energetic linkage of machines, technical building equipment and the building itself is desirable. However, the increased complexity of the interacting sub-systems, multiple time-variant target values and stochastic influences by the production environment, weather and energy markets make it difficult to efficiently control the energy production, storage and consumption in the hybrid industrial smart grids. The studied deep reinforcement learning approach allows to explore the solution space for proper control policies which minimize a cost function. The deep neural network of the DRL agent is based on a multilayer perceptron (MLP), Long Short-Term Memory (LSTM) and convolutional layers. The agent is trained within multiple Modelica-based factory simulation environments by the Advantage Actor Critic algorithm (A2C). The DRL controller is evaluated by means of the simulation and then compared to a conventional, rule-based approach. Finally, the results indicate that the DRL approach is able to improve the control performance and significantly reduce energy respectively operating costs of industrial smart grids.Keywords: industrial smart grids, energy efficiency, deep reinforcement learning, optimal control
Procedia PDF Downloads 1951259 Sesamol Decreases Melanin Biosynthesis via Melanogenesis-Related Gene Expressions in Melan-a Cells
Authors: Seung-Hwa Baek, In-Jung Nam, Sang-Han Lee
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The development of anti-melanogenic agents is important for the prevention of serious esthetic problem like a melasma, freckle, age spots, and chloasma. The aim of this study was to investigate the anti-melanogenic effect of sesamol, an active lignan isolated from sesame seed, by mushroom and cellular tyrosinase assay, melanin content and the analysis of melanogensis-related mRNA expressions in melana cells. Sesamol showed strong inhibitory activity against the mushroom tyrosinase in a dose-dependent manner. Intracellular tyrosinase inhibition activity was also confirmed by zymography. At a concentration of 50 μM, sesamol inhibited melanin production in melan-a cells with no cytoxicity while those of phenylthiourea (PTU) as a positive control were the same condition. Sesamol significantly inhibited the expression of melanogensis-related genes, such as tyrosinase, tyrosinase-related protein-1 (TRP-1), dopachrome tautomerase (Dct), microphthalmia-associated transcription factor (MITF) and melanocortin 1 receptor (MC1R). These findings indicate that sesamol could reduce melanin biosynthesis via the downregulation of tyrosinase activity and melanin production via subsequent gene expression of melanogenesis-related proteins. Together, these results suggest that the sesamol have strong potential in inhibiting melanin biosynthesis, in that the substance may be used as a new skin-whitening agent of cosmetic materials.Keywords: sesamol, sesame seed, melanin biosynthesis, melanogenesis-related gene, skin-whitening agent
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