Search results for: combined inhibition

Authors: Maria Debora Braga, Luigi Riso, Maria Grazia Zoia

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Risk-based approaches to asset allocation are portfolio construction methods that do not rely on the input of expected returns for the asset classes in the investment universe and only use risk information. They include the Minimum Variance Strategy (MV strategy), the traditional (volatility-based) Risk Parity Strategy (SRP strategy), the Most Diversified Portfolio Strategy (MDP strategy) and, for many, the Equally Weighted Strategy (EW strategy). All the mentioned approaches were based on portfolio volatility as a reference risk measure but in 2023, the Kurtosis-based Risk Parity strategy (KRP strategy) and the Minimum Kurtosis strategy (MK strategy) were introduced. Understandably, they used the fourth root of the portfolio-fourth moment as a proxy for portfolio kurtosis to work with a homogeneous function of degree one. This paper contributes mainly theoretically and methodologically to the framework of risk-based asset allocation approaches with two steps forward. First, a new and more flexible objective function considering a linear combination (with positive coefficients that sum to one) of portfolio volatility and portfolio kurtosis is used to alternatively serve a risk minimization goal or a homogeneous risk distribution goal. Hence, the new basic idea consists in extending the achievement of typical risk-based approaches’ goals to a combined risk measure. To give the rationale behind operating with such a risk measure, it is worth remembering that volatility and kurtosis are expressions of uncertainty, to be read as dispersion of returns around the mean and that both preserve adherence to a symmetric framework and consideration for the entire returns distribution as well, but also that they differ from each other in that the former captures the “normal” / “ordinary” dispersion of returns, while the latter is able to catch the huge dispersion. Therefore, the combined risk metric that uses two individual metrics focused on the same phenomena but differently sensitive to its intensity allows the asset manager to express, in the context of an objective function by varying the “relevance coefficient” associated with the individual metrics, alternatively, a wide set of plausible investment goals for the portfolio construction process while serving investors differently concerned with tail risk and traditional risk. Since this is the first study that also implements risk-based approaches using a combined risk measure, it becomes of fundamental importance to investigate the portfolio effects triggered by this innovation. The paper also offers a second contribution. Until the recent advent of the MK strategy and the KRP strategy, efforts to highlight interesting properties of risk-based approaches were inevitably directed towards the traditional MV strategy and SRP strategy. Previous literature established an increasing order in terms of portfolio volatility, starting from the MV strategy, through the SRP strategy, arriving at the EQ strategy and provided the mathematical proof for the “equalization effect” concerning marginal risks when the MV strategy is considered, and concerning risk contributions when the SRP strategy is considered. Regarding the validity of similar conclusions when referring to the MK strategy and KRP strategy, the development of a theoretical demonstration is still pending. This paper fills this gap.

Keywords: risk parity, portfolio kurtosis, risk diversification, asset allocation

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Authors: Florian Engel

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Only with a radical change to an intrinsically motivated project team, through giving the employees the freedom for autonomy, mastery and purpose, it is then possible to develop excellent products. With these changes, combined with using a rapid application development approach, the group of users serves as an important indicator to test the market needs, rather than only as the stakeholders for requirements.

Keywords: intrinsic motivation, requirements elicitation, self-directed work, stakeholder participation

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Authors: Runliang Wang, Jianhua Liu, Duo Jia, Xiaoyu Ding

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The contact between sealing surfaces plays a vital role in guaranteeing the sealing performance of various seals. To date, analyses of sealing structures have rarely considered both structural parameters (macroscale) and surface roughness information (microscale) of sealing surfaces due to the complex modeling process. Meanwhile, most of the contact analyses applied to seals were conducted only under normal loading, which still existssome distance from real loading conditions in engineering. In this paper, a multiscale rough contact model, which took both macrostructural parameters of seals and surface roughness information of sealing surfaces into consideration for the cone-cone seal, was established. By using the finite element method (FEM), the combined normal and tangential loading was applied to the model to simulate the assembly process of the cone-cone seal. The evolution of the contact behaviors during the assembly process, such as the real contact area (RCA), the distribution of contact pressure, and contact status, are studied in detail. The results showed the non-linear relationship between the RCA and the load, which was different from the normal loading cases. In addition, the evolution of the real contact area of cone-cone seals with isotropic and anisotropic rough surfaces are also compared quantitatively.

Keywords: contact mechanics, FEM, randomly rough surface, real contact area, sealing

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Authors: Leonor Varandas, Pedro D. Gaspar, Martim L. Aguiar

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One of the biggest concerns in the field of agriculture is around the energy efficiency of robots that will perform agriculture’s activity and their charging methods. In this paper, two different charging methods for agricultural standalone docking stations are shown that will take into account various variants as field size and its irregularities, work’s nature to which the robot will perform, deadlines that have to be respected, among others. Its features also are dependent on the orchard, season, battery type and its technical specifications and cost. First charging base method focuses on wireless charging, presenting more benefits for small field. The second charging base method relies on battery replacement being more suitable for large fields, thus avoiding the robot stop for recharge. Existing many methods to charge a battery, the CC CV was considered the most appropriate for either simplicity or effectiveness. The choice of the battery for agricultural purposes is if most importance. While the most common battery used is Li-ion battery, this study also discusses the use of graphene-based new type of batteries with 45% over capacity to the Li-ion one. A Battery Management Systems (BMS) is applied for battery balancing. All these approaches combined showed to be a promising method to improve a lot of technical agricultural work, not just in terms of plantation and harvesting but also about every technique to prevent harmful events like plagues and weeds or even to reduce crop time and cost.

Keywords: agricultural mobile robot, charging methods, battery replacement method, wireless charging method

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Authors: Atoui Oussama, Maazoun Azer, Belkassem Bachir, Pyl Lincy, Lecompte David

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For many decades, researchers have been focused on understanding the dynamic behavior of different structures and materials subjected to fragment impact or blast loads separately. The explosion mechanics, as well as the impact physics studies dealing with the numerical modeling of the response of protective structures under the synergistic effect of a blast wave and the impact of fragments, are quite limited in the literature. This article numerically evaluates the nonlinear dynamic behavior and damage mechanisms of Aluminum plates EN AW-1050A- H24 under different combined loading scenarios varied by the sequence of the applied loads using the commercial software LS-DYNA. For one hand, with respect to the terminal ballistic field investigations, a Lagrangian (LAG) formulation is used to evaluate the different failure modes of the target material in case of a fragment impact. On the other hand, with respect to the blast field analysis, an Arbitrary Lagrangian-Eulerian (ALE) formulation is considered to study the fluid-structure interaction (FSI) of the shock wave and the plate in case of a blast loading. Four different loading scenarios are considered: (1) only blast loading, (2) only fragment impact, (3) blast loading followed by a fragment impact and (4) a fragment impact followed by blast loading. From the numerical results, it was observed that when the impact load is applied to the plate prior to the blast load, it suffers more severe damage due to the hole enlargement phenomenon and the effects of crack propagation on the circumference of the damaged zone. Moreover, it was found that the hole from the fragment impact loading was enlarged to about three times in diameter as compared to the diameter of the projectile. The validation of the proposed computational model is based in part on previous experimental data obtained by the authors and in the other part on experimental data obtained from the literature. A good correspondence between the numerical and experimental results is found.

Keywords: computational analysis, combined loading, explosion mechanics, hole enlargement phenomenon, impact physics, synergistic effect, terminal ballistic

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Authors: Eri Sulyanti, Trimurti Habazar, Eti Farda Husen, Abdi Dharma, Nasril Nasir

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In this study, combination of some biocontrol agents with different mechanisms was an alternative to improve the effectiveness of the biological control agents. Single and combined applications of indigenous Pseudomonas fluorescens and Arbuscular Mychorrhizae Fungi (AM Fungi) isolates were tested to induce the resistance on susceptible Cavendish banana against F.oxysporum f. sp. cubense race 4 under greenhouse conditions. These isolates originally isolated from healthy banana rhizosphere at endemic Fusarium wilt areas in the centre of production banana in West Sumatra. These researches were conducted with Randomized Block Design with 16 treatments and 10 replications. The treatments were three indigenous isolates of Pseudomonas fluorescens (Par1-Cv, Par4-Rj1, Par2-Jt1) and 3 isolates of AM Fungi (Gl1BuA4, Gl2BuA6, and Gl1KeP3. The biocontrol agents were applied as single agents and combination two of them. This study demonstrated that the application of combination biocontrol organisms Pseudomonas fluorescens and AM Fungi provided were more effective than single application. The combination of Par1-Cv and Gl1BuA4 isolates was the most effective to control Fusarium wilt and followed by the combination of Par1-Cv and Gl2BuA6 and Par2-Jt1 and Gl1P3.

Keywords: pseudomonad fluorescens (Pf), arbuscular mychorrhizae fungi (AM Fungi) indigenous isolates, fusarium oxysporum f. sp. cubense, soil rhizosphere

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Authors: Hilman Agil Satria, Rezky Naufan Hendrawan

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Indonesia is vulnerable to geological hazard because of its location in subduction zone and have tropical climate. Landslide is one of the most happened geological hazard in Indonesia, based on Indonesia Geospasial data, at least 194 landslides recorded in 2013. In fact, research location is placed as the third city that most happened landslide in Indonesia. Landslide caused damage of many houses and wrecked the road. The purpose of this research is to make a landslide zone therefore can be used as one of mitigation consideration. The location is in Bruno, Porworejo district Central Java Province Indonesia at 109.903 – 109.99 and -7.59 – -7.50 with 10 Km x 10 Km wide. Based on geological mapping result, the research location consist of Late Miocene sandstone and claystone, and Pleistocene volcanic breccia and tuff. Those landslide happened in the lithology that close with fault zone. This location has so many geological structures: joints, faults and folds. There are 3 thrust faults, 1 normal faults, 4 strike slip faults and 6 folds. This geological structure movement is interpreted as the main factor that has triggered landslide in this location. This research use field data as well as samples of rock, joint, slicken side and landslide location which is combined with DEM SRTM to analyze geomorphology. As the final result of combined data will be presented as geological map, geological structure map and landslide zone map. From this research we can assume that there is correlation between geological structure and landslide locations.

Keywords: geological structure, landslide, Porworejo, Indonesia

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Authors: Veenu Bala, Yashpal S. Chhonker, Bhavana Kushwaha, Rabi S. Bhatta, Gopal Gupta, Vishnu L. Sharma

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According to UNAIDS 2013 estimate nearly 52% of all individuals living with HIV are now women of reproductive age (15–44 years). Seventy-five percent cases of HIV acquisition are through heterosexual contacts and sexually transmitted infections (STIs), attributable to unsafe sexual behaviour. Each year, an estimated 500 million people acquire atleast one of four STIs: chlamydia, gonorrhoea, syphilis and trichomoniasis. Trichomonas vaginalis (TV) is exclusively sexually transmitted in adults, accounting for 30% of STI cases and associated with pelvic inflammatory disease (PID), vaginitis and pregnancy complications in women. TV infection resulted in impaired vaginal milieu, eventually favoring HIV transmission. In the absence of an effective prophylactic HIV vaccine, prevention of new infections has become a priority. It was thought worthwhile to integrate HIV prevention and reproductive health services including unintended pregnancy protection for women as both are related with unprotected sex. Initially, nonoxynol-9 (N-9) had been proposed as a spermicidal agent with microbicidal activity but on the contrary it increased HIV susceptibility due to surfactant action. Thus, to accomplish an urgent need of novel woman controlled non-detergent microbicidal spermicides benzenepropanamine analogues have been synthesized. At first, five benzenepropanamine-dithiocarbamate hybrids have been synthesized and evaluated for their spermicidal, anti-Trichomonas and anti-fungal activities along with safety profiling to cervicovaginal cells. In order to further enhance the scope of above study benzenepropanamine was hybridized with thiourea as to introduce anti-HIV potential. The synthesized hybrid molecules were evaluated for their reverse transcriptase (RT) inhibition, spermicidal, anti-Trichomonas and antimicrobial activities as well as their safety against vaginal flora and cervical cells. simulated vaginal fluid (SVF) stability and pharmacokinetics of most potent compound versus N-9 was examined in female Newzealand (NZ) rabbits to observe its absorption into systemic circulation and subsequent exposure in blood plasma through vaginal wall. The study resulted in the most promising compound N-butyl-4-(3-oxo-3-phenylpropyl) piperazin-1-carbothioamide (29) exhibiting better activity profile than N-9 as it showed RT inhibition (72.30 %), anti-Trichomonas (MIC, 46.72 µM against MTZ susceptible and MIC, 187.68 µM against resistant strain), spermicidal (MEC, 0.01%) and antifungal activity (MIC, 3.12–50 µg/mL) against four fungal strains. The high safety against vaginal epithelium (HeLa cells) and compatibility with vaginal flora (lactobacillus), SVF stability and least vaginal absorption supported its suitability for topical vaginal application. Docking study was performed to gain an insight into the binding mode and interactions of the most promising compound, N-butyl-4-(3-oxo-3-phenylpropyl) piperazin-1-carbothioamide (29) with HIV-1 Reverse Transcriptase. The docking study has revealed that compound (29) interacted with HIV-1 RT similar to standard drug Nevirapine. It may be concluded that hybridization of benzenepropanamine and thiourea moiety resulted into novel lead with multiple activities including RT inhibition. A further lead optimization may result into effective vaginal microbicides having spermicidal, anti-Trichomonas, antifungal and anti-HIV potential altogether with enhanced safety to cervico-vaginal cells in comparison to Nonoxynol-9.

Keywords: microbicidal, nonoxynol-9, reverse transcriptase, spermicide

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Authors: Mohamed Hesham Hamdy Abdelmohsen, Ahmed Shawky Abdul Aziz, Mona Fawzy Al-Daghma

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Helical piles are widely used as axially and laterally loaded deep foundations. Once they are required to resist bearing combined loads (BCLs), as axial compression and lateral thrust, different behaviour is expected, necessitating further investigation. The objective of the present article is to clarify the behaviour of a single helical pile of different shaft rigidity embedded in cohesion-less soil and subjected to simultaneous or successive loading patterns of BCLs. The study was first developed analytically and extended numerically. The numerical analysis was further verified through a laboratory experimental program on a set of helical pile models. The results indicate highly interactive effects of the studied parameters, but it is obviously confirmed that the pile performance increases with both the increase of shaft rigidity and the change of BCLs loading pattern from simultaneous to successive. However, it is noted that the increase of vertical load does not always enhance the lateral capacity but may cause a decrement in lateral capacity, as observed with helical piles of flexible shafts. This study provides insightful information for the design of helical piles in structures loaded by complex sequence of forces, wind turbines, and industrial shafts.

Keywords: helical pile, lateral loads, combined loads, cohesion-less soil, analytical, numerical

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Authors: Smita Jauhari, Bhupendra Mistry

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Schiff base (E)-2-methyl-N-(tetrazolo[1,5-a]quinolin-4-ylmethylene)aniline (QMA) was synthesized, and its inhibitive effect for mild steel in 1M HCl solution was investigated by weight loss measurement and electrochemical tests.From the weight loss measurements and electrochemical tests, it was observed that the inhibition efficiency increases with the increase in the Schiff base concentration and reaches a maximum at the optimum concentration. This is further confirmed by the decrease in corrosion rate. It is found that the system follows Langmuir adsorption isotherm.

Keywords: Schiff base, acid corrosion, electrochemical impedance spectroscopy, polarization

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Authors: Sajida Saqira, Anthony Chariton, Grant C. Hose

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The Anthropocene has seen dramatic environmental changes which are affecting every ecosystem on earth. Freshwater ecosystems are particularly vulnerable as they are at risk from the many activities that go on and contaminants that are released in catchments. They are thus subject to many stressors simultaneously. Freshwater ecosystems respond to stress at all levels of biological organization, from subcellular to community structure and ecosystem functioning. The aim of this study was to examine the resistance and resilience of freshwater ecosystems to multiple stressors. Here we explored the individual and combined effects of copper as a chemical stressor and common carp (Cyprinus carpio) as a biological stressor on the health, functioning, and recovery of outdoor experimental pond ecosystems in a long-term, controlled, factorial experiment. Primary productivity, decomposition, and water and sediment quality were analysed at regular intervals for one year to understand the health and functioning of the ecosystems. Changes to benthic biota were quantified using DNA-based and traditional microscopy-based counts of invertebrates. Carp were added to the ponds to copper contaminated sediments (with controls) to explore the combined effects of copper and carp and removed after six months to explore the resilience and recovery of the system. The outcomes of this study will advance our understanding of the impacts of multiple stressors on freshwater ecosystems, and the resilience of these systems to copper and C. carpio, which are both globally significant stressors in freshwater systems.

Keywords: carp, copper, ecosystem health, freshwater ecosystem, multiple stressors

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Authors: Hajer Chaker Ben Hadj Kacem, Thouraya Slama, Néjiba El Yetim Zribi

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This paper analyzes the effects of gender, affiliation, prior work experience, social work, and vicarious learning through family role models on entrepreneurial skills development by students when they have learned through the entrepreneurship method in Tunisia. Authors suggest that these variables enhance the development of students’ entrepreneurial skills when combined with teaching through entrepreneurship. The article assesses the impact of these combinations by comparing their effects on the development of thirteen students’ entrepreneurial competencies, namely entrepreneurial mindset, core self-evaluation, entrepreneurial attitude, entrepreneurial knowledge, creativity, financial literacy, managing ambiguity, marshaling of resources, planning, teaching methods, entrepreneurial teachers, innovative employee, and Entrepreneurial intention. Authors use a two-sample independent t-test to make the comparison, and the results indicate that, when combined with teaching through the entrepreneurship method, students with prior work experience developed better six entrepreneurial skills; students with social work developed better three entrepreneurial skills, men developed better four entrepreneurial skills than women. However, all students developed their entrepreneurial skills through this practical method regardless of their affiliation and their vicarious learning through family role models.

Keywords: affiliation, entrepreneurial skills, gender, role models, social work, teaching through entrepreneurship, vicarious learning, work experience

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Authors: Afroza Parvin, Md. Mahmudul Hasan, Md. Rokunozzaman, Papon Debnath

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The effluents of textile industries have considerable amounts of heavy metals, causing potential microbial metal loads if discharged into the environment without treatment. Aim: In this present study, both lactose and non-lactose fermenting bacterial isolates were isolated from textile industrial effluents of a specific region of Bangladesh, named Savar, to compare and understand the load of heavy metals in these microorganisms determining the effects of heavy metal resistance properties on antibiotic resistance. Methods: Five different textile industrial canals of Savar were selected, and effluent samples were collected in 2016 between June to August. Total bacterial colony (TBC) was counted for day 1 to day 5 for 10-6 dilution of samples to 10-10 dilution. All the isolates were isolated and selected using 4 differential media, and tested for the determination of minimum inhibitory concentration (MIC) of heavy metals and antibiotic susceptibility test with plate assay method and modified Kirby-Bauer disc diffusion method, respectively. To detect the combined effect of heavy metals and antibiotics, a binary exposure experiment was performed, and to understand the plasmid profiling plasmid DNA was extracted by alkaline lysis method of some selective isolates. Results: Most of the cases, the colony forming units (CFU) per plate for 50 ul diluted sample were uncountable at 10-6 dilution, however, countable for 10-10 dilution and it didn’t vary much from canal to canal. A total of 50 Shigella, 50 Salmonella, and 100 E.coli (Escherichia coli) like bacterial isolates were selected for this study where the MIC was less than or equal to 0.6 mM for 100% Shigella and Salmonella like isolates, however, only 3% E. coli like isolates had the same MIC for nickel (Ni). The MIC for chromium (Cr) was less than or equal to 2.0 mM for 16% Shigella, 20% Salmonella, and 17% E. coli like isolates. Around 60% of both Shigella and Salmonella, but only 20% of E.coli like isolates had a MIC of less than or equal to 1.2 mM for lead (Pb). The most prevalent resistant pattern for azithromycin (AZM) for Shigella and Salmonella like isolates was found 38% and 48%, respectively; however, for E.coli like isolates, the highest pattern (36%) was found for sulfamethoxazole-trimethoprim (SXT). In the binary exposure experiment, antibiotic zone of inhibition was mostly increased in the presence of heavy metals for all types of isolates. The highest sized plasmid was found 21 Kb and 14 Kb for lactose and non-lactose fermenting isolates, respectively. Conclusion: Microbial resistance to antibiotics and metal ions, has potential health hazards because these traits are generally associated with transmissible plasmids. Microorganisms resistant to antibiotics and tolerant to metals appear as a result of exposure to metal-contaminated environments.

Keywords: antibiotics, effluents, heavy metals, minimum inhibitory concentration, resistance

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Authors: Panupong Makvichian

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Global Navigation Satellite System (GNSS) is nowadays a common technology that improves navigation functions in our life. Additionally, GNSS is also being employed on behalf of an accurate atmospheric sensor these times. Meteorology is a practical application of GNSS, which is unnoticeable in the background of people’s life. GNSS Precise Point Positioning (PPP) is a positioning method that requires data from a single dual-frequency receiver and precise information about satellite positions and satellite clocks. In addition, careful attention to mitigate various error sources is required. All the above data are combined in a sophisticated mathematical algorithm. At this point, the research is going to demonstrate how GNSS and PPP method is capable to provide high-precision estimates, such as 3D positions or Zenith tropospheric delays (ZTDs). ZTDs combined with pressure and temperature information allows us to estimate the water vapor in the atmosphere as precipitable water vapor (PWV). If the process is replicated for a network of GNSS sensors, we can create thematic maps that allow extract water content information in any location within the network area. All of the above are possible thanks to the advances in GNSS data processing. Therefore, we are able to use GNSS data for climatic trend analysis and acquisition of the further knowledge about the atmospheric water content.

Keywords: GNSS, precise point positioning, Zenith tropospheric delays, precipitable water vapor

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Authors: Damien Gondre, Hatem Ben Maad, Abdelkrim Trabelsi, Frédéric Kuznik, Joseph Virgone

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The use of a radiant cooling solution would enable to lower cooling needs which is of great interest when the demand is initially high (hot climate). But, radiant systems are not naturally compatibles with humid climates since a low-temperature surface leads to condensation risks as soon as the surface temperature is close to or lower than the dew point temperature. A radiant cooling system combined to a dehumidification system would enable to remove humidity for the space, thereby lowering the dew point temperature. The humidity removal needs to be especially effective near the cooled surface. This requirement could be fulfilled by a system using a single desiccant fluid for the removal of both excessive heat and moisture. This task aims at providing an estimation of the specification requirements of such system in terms of cooling power and dehumidification rate required to fulfill comfort issues and to prevent any condensation risk on the cool panel surface. The present paper develops a preliminary study on the specification requirements, performances and behavior of a combined dehumidifier/cooling ceiling panel for different operating conditions. This study has been carried using the TRNSYS software which allows nodal calculations of thermal systems. It consists of the dynamic modeling of heat and vapor balances of a 5m x 3m x 2.7m office space. In a first design estimation, this room is equipped with an ideal heating, cooling, humidification and dehumidification system so that the room temperature is always maintained in between 21^◦C and 25^◦C with a relative humidity in between 40% and 60%. The room is also equipped with a ventilation system that includes a heat recovery heat exchanger and another heat exchanger connected to a heat sink. Main results show that the system should be designed to meet a cooling power of 42W.m⁻² and a desiccant rate of 45 g_H2O.h⁻¹. In a second time, a parametric study of comfort issues and system performances has been achieved on a more realistic system (that includes a chilled ceiling) under different operating conditions. It enables an estimation of an acceptable range of operating conditions. This preliminary study is intended to provide useful information for the system design.

Keywords: dehumidification, nodal calculation, radiant cooling panel, system sizing

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Authors: Jichan Jang

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Mycobacterium abscessus is a rapidly growing life-threatening mycobacterium with multiple drug-resistance mechanisms. In this study, we screened the library to identify active molecules targeting Mycobacterium abscessus using resazurin live/dead assays. In this screening assay, the Z-factor was 0.7, as an indication of the statistical confidence of the assay. A cut-off of 80% growth inhibition in the screening resulted in the identification of four different compounds at a single concentration (20 μM). Dose-response curves identified three different hit candidates, which generated good inhibitory curves. All hit candidates were expected to have different molecular targets. Thus, we found that compound X, identified, may be a promising candidate in the M. abscessus drug discovery pipeline.

Keywords: Mycobacterium abscessus, antibiotics, drug discovery, emerging Pathogen

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Authors: Samira Ghizellaoui, Manel Boumagoura

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The municipality of Constantine in eastern Algeria draws water from the Hamma groundwater source. The high fouling capacity is due to the high content of bicarbonate (442 mg/L) and calcium (136 mg/L). This work focuses on the use of three new green inhibitors for reducing calcium carbonate scale formation: gallic acid, quercetin and alginate, and on the comparison between them. These inhibitors have proven to be green antiscalants because they have no impact on the environment. Electrochemical methods (chronoamperometry and impedancemetry) were used to evaluate their performance. According to the study, these inhibitors are excellent green chemical inhibitors of scaling, and the best inhibitor is quercetin because it gave a good result with a lower concentration (2mg/L) compared to others inhibitors.

Keywords: scaling, green inhibitor, chronoamperometry, impedancemetry

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Authors: Lea Boidin, Martha Baydoun, Bertrand Leroux, Olivier Morales, Samir Acherar, Celine Frochot, Nadira Delhem

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Ovarian cancer (OC) is one of the most defying diseases in gynecologic oncology. Even though surgery remains crucial in the therapy of patients with primary ovarian cancer, recurrent recidivism calls for the development of new therapy protocols to propose for patients dealing with this cancer. FRα is described as a tumor‐associated antigen in OC, where FRα expression is usually linked with more poorly differentiated, aggressive tumors. The Photodynamic treatment (PDT) available data have shown improvements in the uptake of small tumors and in the induction of a proper anti-tumoral immune response. In order to target specifically peritoneal metastatis, which overexpress FRα, a new-patented PS coupled with folic acid has been developed in our team. Herein we propose PDT using this new patented PS for PDT applied in an in vivo mice model. The efficacy of the treatment was evaluated in mice without and with PBMC reconstitution. Mice were divided into four groups: Non-Treated, PS, Light Only, and PDT Treated and subjected to illumination by laser set at 668nm with a duration of illumination of 45 minutes (or 1 min of illumination followed by 2 minutes of pause repeated 45 times). When mice were not reconstituted and after fractionized PDT protocol, a significant decrease in the tumor volume was noticed. An induction in the anti-tumoral cytokine IFNγ chaperoned this decrease while a subsequent inhibition in the cytokine TGFβ. Even more crucial, when mice were reconstituted and upon PDT, the fold of tumor decrease was even higher. An immune response was activated decoded with an increase in NK, CD3 +, LT helper and Cytotoxic T cells. Thereafter, an increase in the expression of the cytokines IFNγ and TNFα were noticed while an inhibition in TGFβ, IL8 and IL10 accompanied this immune response activation. Therefore, our work has shown for the first time that a fractionized PDT protocol using a folate-targeted PDT is effective for treatment of ovarian cancer. The interest in using PDT in this case, goes beyond the local induction of tumor apoptosis only, but can promote subsequent anti-tumor response. Most of the therapies currently used to treat ovarian cancer, have an uncooperative outcomes on the host immune response. The readiness of a tumor adjuvant treatment like PDT adequate in eliminating the tumor and in concert stimulating anti-tumor immunity would be weighty.

Keywords: folate receptor, ovarian cancer, photodynamic therapy, humanized mice model

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Authors: R. L. Shirole, N. L. Shirole, R. B. Patil, M. N. Saraf

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The present investigation aimed to elucidate the probable mechanism of antiasthmatic action of essential oil of Pistacia integerrima J.L. Stewart ex Brandis galls (EOPI). EOPI was investigated for its potential antiasthmatic action using in vitro antiallergic assays mast cell degranulation and soyabean lipoxidase enzyme activit, and spasmolytic action using isolated guinea pig ileum preparation. In vivo studies included lipopolysaccharide-induced bronchial inflammation in rats and airway hyperresponsiveness in ovalbumin in sensitized guinea pigs using spirometry. Data was analysed by GraphPad Prism 5.01 and results were expressed as means ± SEM. P < 0.05 was considered to be significant. EOPI inhibits 5-lipoxidase enzyme activity, DPPH scavenging activity and erythropoietin- induced angiogenesis. It showed dose dependent anti-allergic activity by inhibiting compound 48/80 induced mast cell degranulation. The finding that essential oil induced inhibition of transient contraction of acetylcholine in calcium free medium, and relaxation of S-(-)-Bay 8644-precontracted isolated guinea pig ileum jointly suggest that suggesting that the L-subtype Cav channel is involved in spasmolytic action of EOPI. Treatment with EOPI dose dependently (7.5, 15 and 30 mg/kg i.p.) inhibited lipopolysaccharide- induced increased in total cell count, neutrophil count, nitrate-nitrite, total protein, albumin levels in bronchoalveolar fluid and myeloperoxidase levels in lung homogenates. Mild diffused lesions involving focal interalveolar septal, intraluminal infiltration of neutrophils were observed in EOPI (7.5 &15 mg/kg) pretreated while no abnormality was detected in EOPI (30 mg/kg) and roflumilast (1mg/kg) pretreated rats. Roflumilast was used as standard. EOPI reduced the respiratory flow due to gasping in ovalbumin sensitized guinea pigs. The study demonstrates the effectiveness of EOPI in bronchial asthma possibly related to its ability to inhibit L-subtype Cav channel, mast cell stabilization, antioxidant, angiostatic and through inhibition of 5-lipoxygenase enzyme.

Keywords: asthma, lipopolysaccharide, spirometry, Pistacia integerrima J.L. Stewart ex Brandis, essential oil

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Authors: Ildiko Fekete-Kertesz, Jade Chaker, Sylvain Berthelot, Viktoria Feigl, Monika Molnar, Lidia Favier

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There has been growing concern about emerging micropollutants in recent years, because of the possible environmental and health risk posed by these substances, which are released into the environment as a consequence of anthropogenic activities. Among them pharmaceuticals are currently not considered under water quality regulations; however, their potential effect on the environment have become more frequent in recent years. Due to the fact that these compounds can be detected in natural water matrices, it can be concluded, that the currently applied water treatment processes are not efficient enough for their effective elimination. To date, advanced oxidation processes (AOPs) are considered as highly competitive water treatment technologies for the removal of those organic micropollutants not treatable by conventional techniques due to their high chemical stability and/or low biodegradability. AOPs such as (photo)chemical oxidation and heterogeneous photocatalysis have proven their potential in degrading harmful organic compounds from aqueous matrices. However, some of these technologies generate reaction by-products, which can even be more toxic to aquatic organisms than the parent compounds. Thus, target compound removal does not necessarily result in the removal of toxicity. Therefore, to evaluate process efficiency the determination of the toxicity and ecotoxicity of the reaction intermediates is crucial to estimate the environmental risk of such techniques. In this context, the present study investigates the effectiveness of TiO2 assisted photodegradation for the removal of emerging water contaminants. Two drugs named losartan (used in high blood pressure medication) and levetiracetam (used to treat epilepsy) were considered in this work. The photocatalytic reactions were carried out with a commercial catalyst usually employed in photocatalysis. Moreover, the toxicity of the by-products generated during the process was assessed with various ecotoxicological methods applying aquatic test organisms from different trophic levels. A series of experiments were performed to evaluate the toxicity of untreated and treated solutions applying the Aliivibrio fischeri bioluminescence inhibition test, the Tetrahymena pyriformis proliferation inhibition test, the Daphnia magna lethality and immobilization tests and the Lemna minor growth inhibition test. The applied ecotoxicological methodology indicated sensitively the toxic effects of the treated and untreated water samples, hence the applied test battery is suitable for the ecotoxicological characterization of TiO2 based photocatalytic water treatment technologies and the indication of the formation of toxic by-products from the parent chemical compounds. Obtained results clearly showed that the TiO2 assisted photodegradation was more efficient in the elimination of losartan than levetiracetam. It was also observed that the treated levetiracetam solutions had more severe effect on the applied test organisms. A possible explanation would be the production of levetiracetam by-products, which are more toxic than the parent compound. The increased toxicity and the risk of formation of toxic metabolites represent one possible limitation to the implementation of photocatalytic treatment using TiO2 for the removal of losartan and levetiracetam. Our results proved that, the battery of ecotoxicity tests used in this work can be a promising investigation tool for the environmental risk assessment of photocatalytic processes.

Keywords: aquatic micropollutants, ecotoxicology, nano titanium dioxide, photocatalysis, water treatment

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Authors: Faizul Azly Abd Dzubir, Muhammad F. Othman

Abstract:

Conventional structural health monitoring approach for mechanical equipment uses inspection data from Non-Destructive Testing (NDT) during plant shut down window and fitness for service evaluation to estimate the integrity of the equipment that is prone to crack damage. Yet, this forecast is fraught with uncertainty because it is often based on assumptions of future operational parameters, and the prediction is not continuous or online. Advanced Diagnostic and Prognostic Technology (ADaPT) uses Acoustic Emission (AE) technology and a stochastic prognostic model to provide real-time monitoring and prediction of mechanical defects or cracks. The forecast can help the plant authority handle their cracked equipment before it ruptures, causing an unscheduled shutdown of the facility. The ADaPT employs process historical data trending, finite element analysis, fitness for service, and probabilistic statistical analysis to develop a prediction model for crack initiation and growth due to mechanical damage. The prediction model is combined with live equipment operating data for real-time prediction of the remaining life span owing to fracture. ADaPT was devised at a hot combined feed exchanger (HCFE) that had suffered creep crack damage. The ADaPT tool predicts the initiation of a crack at the top weldment area by April 2019. During the shutdown window in April 2019, a crack was discovered and repaired. Furthermore, ADaPT successfully advised the plant owner to run at full capacity and improve output by up to 7% by April 2019. ADaPT was also used on a coke drum that had extensive fatigue cracking. The initial cracks are declared safe with ADaPT, with remaining crack lifetimes extended another five (5) months, just in time for another planned facility downtime to execute repair. The prediction model, when combined with plant information data, allows plant operators to continuously monitor crack propagation caused by mechanical damage for improved maintenance planning and to avoid costly shutdowns to repair immediately.

Keywords: mechanical damage, cracks, continuous monitoring tool, remaining life, acoustic emission, prognostic model

Procedia PDF Downloads 62

Authors: Vani Chintapally

Abstract:

The expansion of modest and minimized Global Positioning System (GPS) beneficiaries has prompted most Automatic Vehicle Location (AVL) frameworks today depending solely on satellite-based finding frameworks, as GPS is the most stable usage of these. This paper shows the attributes of a proposed framework for following and dissecting open transport in a run of the mill medium-sized city and complexities the qualities of such a framework to those of broadly useful AVL frameworks. Particular properties of the courses broke down by the AVL framework utilized for the examination of open transport in our study incorporate cyclic vehicle courses, the requirement for particular execution reports, and so forth. This paper particularly manages vehicle movement forecasts and the estimation of station landing time, combined with consequently produced reports on timetable conformance and other execution measures. Another side of the watched issue is proficient exchange of information from the vehicles to the control focus. The pervasiveness of GSM bundle information exchange advancements combined with decreased information exchange expenses have brought on today's AVL frameworks to depend predominantly on parcel information exchange administrations from portable administrators as the correspondences channel in the middle of vehicles and the control focus. This methodology brings numerous security issues up in this conceivably touchy application field.

Keywords: automatic vehicle location (AVL), expectation of landing times, AVL security, data administrations, wise transport frameworks (ITS), guide coordinating

Procedia PDF Downloads 364

Authors: Scott Ashby, Emily Granger, Mark Connellan

Abstract:

Background: In-hospital management of Out-of-Hospital Cardiac Arrest (OHCA) is complex as the aetiologies are varied. Acute coronary angiography has been shown to improve outcomes for patients with coronary occlusion as the cause; however, these patients are difficult to identify. ECG results may help identify these patients, but the accuracy of this diagnostic test is under debate, and requires further investigation. Methods: Arrest and hospital management information was collated retrospectively for OHCA patients who presented to a single clinical site between 2009 and 2013. Angiography results were then collected and checked for significance with survival to discharge. The presence of a severe lesion (>70%) was then compared to categorised ECG findings, and the accuracy of the test was calculated. Results: 104 patients were included in this study, 44 survived to discharge, 52 died and 8 were transferred to other clinical sites. Angiography appears to significantly correlate with survival to discharge. ECG showed 54.8% sensitivity for detecting the presence of a severe lesion within the group that received angiography. A combined criterion including any ECG pathology showed 100% sensitivity and negative predictive value, however, a low specificity and positive predictive value. Conclusion: In the cohort investigated, ST elevation on ECG is not a sensitive enough screening test to be used to determine whether OHCA patients have coronary stenosis as the likely cause of their arrest, and more investigation into whether screening with a combined ECG criterion, or whether all patients should receive angiography routinely following OHCA is needed.

Keywords: out of hospital cardiac arrest, coronary angiography, resuscitation, emergency medicine

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Authors: L. F. Tamele Jr., G. Buonocore, H. F. Muiambo

Abstract:

Asphalt binders play an essential role in the performance and properties of asphalt mixtures. The increase in heavy loads, greater traffic volume, and high tire pressure, combined with a substantial variation in daily and seasonal pavement temperatures, are the main responsible for the failure of asphalt pavements. To avoid or mitigate these failures, the present research proposes the use of thermoplastic polymers, HDPE and LLDPE, and nanoclay Dellite 43B for modification of asphalt in order to improve its thermomechanical and rheological properties. The nanocomposites were prepared by the solution intercalation method in a high shear mixer for a mixing time of 2 h, at 180℃ and 5000 rpm. The addition of Dellite 43B improved the physical, rheological, and thermal properties of asphalt, either separated or in the form of polymer/bitumen blends. The results of the physical characterization showed a decrease in penetration and an increase in softening point, thermal susceptibility, viscosity, and stiffness. On the other hand, thermal characterization showed that the nanocomposites have greater stability at higher temperatures by exhibiting greater amounts of residues and improved initial and final decomposition temperatures. Thus, the modification of asphalt by polymers and nanoclays seems to be a suitable solution for road pavement in countries which experiment with high temperatures combined with long heavy rain seasons.

Keywords: asphalt, nanoclay dellite 43B, polymer modified asphalt, thermal and rheological properties

Procedia PDF Downloads 133

Authors: Carlos Y. Soto, Camila A. Lota, G. Astrid Garzón

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Bacterial biofilms cause an ongoing problem for food safety. They are formed when microorganisms aggregate to form a community that attaches to solid surfaces. Biofilms increase the resistance of pathogens to cleaning, disinfection and antibacterial products. This resistance gives rise to problems for human health, industry, and agriculture. At present, plant extracts rich in polyphenolics are being investigated as natural alternatives to degrade bacterial biofilms. The pomace of the tropical Berry Vaccinium meridionale S. contains high amounts of phenolic compounds. Therefore, in the current study, the antimicrobial and antibiofilm effects of extracts from the pomace of Vaccinium meridionale S. were tested on three foodborne pathogens: Enterohaemorrhagic Escherichia coli O157:H7 (ATCC®700728TM), Staphylococcus aureus subsp. aureus (ATCC® 6538TM), and Salmonella enterica serovar Enteritidis (ATCC® 13076TM). Microwave-assisted extraction was used to extract polyphenols with aqueous methanol (80% v/v) at a solid to solvent ratio of 1:10 (w/v) for 20 min. The magnetic stirring was set at 400 rpm, and the microwave power was adjusted to 400 W. The antimicrobial effect of the extract was assessed by determining the half maximal inhibitory concentration (IC50) against the three food poisoning pathogens at concentrations ranging from 50 to 2,850 μg gallic acid equivalents (GAE)/mL of the extract. Biofilm inhibition was assessed using a crystal violet assay applying the same range of concentration. Three replications of the experiments were carried out, and all analyses were run in triplicate. IC50 values were determined using the GraphPad Prism8® program. Significant differences (P<0.05) among means were identified using one-factor analysis of variance (ANOVA) and the post-hoc least significant difference (LSD) test using the Statgraphics plus program, version 2.1.There was significant difference among the mean IC50 values for the tested bacteria. The IC50 for S. aureus was 48 ± 9 μg GAE/mL, followed by 123 ± 49 μg GAE/mL for Salmonella and 376 ± 32 μg GAE/mL for E. coli. The percent inhibition of the extract on biofilm formation was significantly higher for S. aureus (85.8  0.3), followed by E. coli (74.5  1.0) and Salmonella (53.6  9.7). These findings suggest that polyphenolic extracts obtained from the pomace of V. meridionale S. might be used as natural antimicrobial and anti-biofilm natural agents, effective against S. aureus, E. coli and Salmonella enterica.

Keywords: antibiofilm, antimicrobial, E. coli, S. aureus, salmonella, IC50, pomace, V. meridionale

Procedia PDF Downloads 47

Authors: Abderahim Ahmadou, Alfredo Napoli, Noel Durand, Didier Montet

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Biochar is a microporous and adsorbent solid carbon product obtained from the pyrolysis of various organic materials (biomass, agricultural waste). Biochar is distinguished from vegetable charcoal by its manufacture methods. Biochar is used as the amendment in soils to give them favorable characteristics under certain conditions, i.e., absorption of water and its release at low speed. Cashew nuts shell from Mali is usually discarded on land by local processors or burnt as a mean for waste management. The burning of this biomass poses serious socio-environmental problems including greenhouse gas emission and accumulation of tars and soot on houses closed to factories, leading to neighbor complaints. Some mycotoxins as aflatoxins are carcinogenic compounds resulting from the secondary metabolism of molds that develop on plants in the field and during their conservation. They are found at high level on some seeds and nuts in Africa. Ochratoxin A, member of mycotoxins, is produced by various species of Aspergillus and Penicillium. Human exposure to Ochratoxin A can occur through consumption of contaminated food products, particularly contaminated grain, as well as coffee, wine grapes. We showed that cashew shell biochars produced at 400, 600 and 800°C adsorbed aflatoxins (B1, B2, G1, G2) at 100% by filtration (rapid contact) as well as by stirring (long contact). The average percentage of adsorption of Ochratoxin A was 35% by filtration and 80% by stirring. The duration of the biochar-mycotoxin contact was a significant parameter. The effect of biochar was also tested on two strains of toxigenic molds: Aspergillus parasiticus (producers of Aflatoxins) and Aspergillus carbonarius (producers of Ochratoxins). The growth of the strain Aspergillus carbonarius was inhibited at up to 60% by the biochar at 600°C. An opposite effect to the inhibition was observed on Aspergillus parasiticus using the same biochar. In conclusion, we observed that biochar adsorbs mycotoxins: Aflatoxins and Ochratoxin A to different degrees; 100% adsorption of aflatoxins under all conditions (filtration and stirring) and adsorption of Ochratoxin A varied depending on the type of biochar and the experiment conditions (35% by filtration and 85% by stirring). The effects of biochar at 600 °C on the toxigenic molds: Aspergillus parasiticus and Aspergillus carbonarius, varied according to the experimental conditions and the strains. We observed an opposite effect on the growth with an inhibition of Aspergillus carbonarius up to 60% and a stimulated growth of Aspergillus parasiticus.

Keywords: biochar, cashew nut shell, mycotoxins, toxicogenic molds

Procedia PDF Downloads 159

Authors: Aravind G., Arshinder Kaur, Pushpavanam S.

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There is a strong emphasis on shifting to electric vehicles (EVs) throughout the globe for reducing the impact on global warming following the Paris climate accord. Lithium-ion batteries (LIBs) are predominantly used in EVs, and these can be a significant threat to the environment if not disposed of safely. Lithium is also a valuable resource not widely available. There are several research groups working on developing an efficient recycling process for LIBs. Two routes - pyrometallurgical and hydrometallurgical processes have been proposed for recycling LIBs. In this paper, we focus on life cycle assessment (LCA) as a tool to quantify the environmental impact of these recycling processes. We have defined the boundary of the LCA to include only the recycling phase of the end-of-life (EoL) of the battery life cycle. The analysis is done assuming ideal conditions for the hydrometallurgical and a combined hydrometallurgical and pyrometallurgical process in the inventory analysis. CML-IA method is used for quantifying the impact assessment across eleven indicators. Our results show that cathode, anode, and foil contribute significantly to the impact. The environmental impacts of both hydrometallurgical and combined recycling processes are similar across all the indicators. Further, the results of LCA are used in developing a multi-objective optimization model for the design of lithium-ion battery recycling network. Greenhouse gas emissions and cost are the two parameters minimized for the optimization study.

Keywords: life cycle assessment, lithium-ion battery recycling, multi-objective optimization, network design, reverse supply chain

Procedia PDF Downloads 135

Authors: Boukli Hacene Faiza, Soufi Wassila, Ghalem Said

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The oral antidiabetics drugs such as alpha glucosidase inhibitors present undesirable effects like acarbose. Flavonoids are class of molecules widely distributed in plants, for this reason we are interested in our work to study the inhibition in silico of alpha glucosidase by natural ligands ( flavonoids analogues) using molecular modeling methods using MOE (Molecular Operating Environment) software to predict their interaction with this enzyme with score energy, ADME /T tests and druglikeness properties experiments. Two flavonoids Beicalein and Apigenin have high binding affinity with alpha glucosidase with lower IC50 supposed potent inhibitors.

Keywords: alpha glucosidase, flavonoides analogues, drug research, molecular modeling

Procedia PDF Downloads 92

Authors: Soumya Bhattacharjya, Avinandan Sahoo, Gaurav Datta

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Wind fragility analysis of chimney is often carried out disregarding temperature effect. However, the combined effect of wind and temperature is the most critical limit state for chimney design. Hence, in the present paper, an efficient fragility analysis for concrete chimney is explored under combined wind and temperature effect. Wind time histories are generated by Davenports Power Spectral Density Function and using Weighed Amplitude Wave Superposition Technique. Fragility analysis is often carried out in full Monte Carlo Simulation framework, which requires extensive computational time. Thus, in the present paper, an efficient adaptive metamodelling technique is adopted to judiciously approximate limit state function, which will be subsequently used in the simulation framework. This will save substantial computational time and make the approach computationally efficient. Uncertainty in wind speed, wind load related parameters, and resistance-related parameters is considered. The results by the full simulation approach, conventional metamodelling approach and proposed adaptive metamodelling approach will be compared. Effect of disregarding temperature in wind fragility analysis will be highlighted.

Keywords: adaptive metamodelling technique, concrete chimney, fragility analysis, stochastic extreme wind load, temperature effect

Procedia PDF Downloads 201

Authors: Saeed Karimi, Ali Behbahaninia

Abstract:

In this study, the design and optimization of combined cooling, heating, and power system (CCHP) for a sustainable building are dealt with. Sustainable buildings are environmentally responsible and help us to save energy also reducing waste, pollution and environmental degradation. CCHP systems are widely used to save energy sources. In these systems, electricity, cooling, and heating are generating using just one primary energy source. The selection of the size of components based on the maximum demand of users will lead to an increase in the total cost of energy and equipment for the building complex. For this purpose, a system was designed in which the prime mover (gas turbine), heat recovery boiler, and absorption chiller are lower than the needed maximum. The difference in months with peak consumption is supplied with the help of electrical absorption chiller and auxiliary boiler (and the national electricity network). In this study, the optimum capacities of each of the equipment are determined based on Thermo economic method, in a way that the annual capital cost and energy consumption will be the lowest. The design was done for a gas turbine prime mover, and finally, the optimum designs were investigated using exergy analysis and were compared with a traditional energy supply system.

Keywords: sustainable building, CCHP, energy optimization, gas turbine, exergy, thermo-economic

Procedia PDF Downloads 74