Search results for: crest factor reduction
8268 Broadband Optical Plasmonic Antennas Using Fano Resonance Effects
Authors: Siamak Dawazdah Emami, Amin Khodaei, Harith Bin Ahmad, Hairul A. Adbul-Rashid
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The Fano resonance effect on plasmonic nanoparticle materials results in such materials possessing a number of unique optical properties, and the potential applicability for sensing, nonlinear devices and slow-light devices. A Fano resonance is a consequence of coherent interference between superradiant and subradiant hybridized plasmon modes. Incident light on subradiant modes will initiate excitation that results in superradiant modes, and these superradient modes possess zero or finite dipole moments alongside a comparable negligible coupling with light. This research work details the derivation of an electrodynamics coupling model for the interaction of dipolar transitions and radiation via plasmonic nanoclusters such as quadrimers, pentamers and heptamers. The directivity calculation is analyzed in order to qualify the redirection of emission. The geometry of a configured array of nanostructures strongly influenced the transmission and reflection properties, which subsequently resulted in the directivity of each antenna being related to the nanosphere size and gap distances between the nanospheres in each model’s structure. A well-separated configuration of nanospheres resulted in the structure behaving similarly to monomers, with spectra peaks of a broad superradiant mode being centered within the vicinity of 560 nm wavelength. Reducing the distance between ring nanospheres in pentamers and heptamers to 20~60 nm caused the coupling factor and charge distributions to increase and invoke a subradiant mode centered within the vicinity of 690 nm. Increasing the outside ring’s nanosphere distance from the centered nanospheres caused the coupling factor to decrease, with the coupling factor being inversely proportional to cubic of the distance between nanospheres. This phenomenon led to a dramatic decrease of the superradiant mode at a 200 nm distance between the central nanosphere and outer rings. Effects from a superradiant mode vanished beyond a 240 nm distance between central and outer ring nanospheres.Keywords: fano resonance, optical antenna, plasmonic, nano-clusters
Procedia PDF Downloads 4308267 Role of von Willebrand Factor Antigen as Non-Invasive Biomarker for the Prediction of Portal Hypertensive Gastropathy in Patients with Liver Cirrhosis
Authors: Mohamed El Horri, Amine Mouden, Reda Messaoudi, Mohamed Chekkal, Driss Benlaldj, Malika Baghdadi, Lahcene Benmahdi, Fatima Seghier
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Background/aim: Recently, the Von Willebrand factor antigen (vWF-Ag)has been identified as a new marker of portal hypertension (PH) and its complications. Few studies talked about its role in the prediction of esophageal varices. VWF-Ag is considered a non-invasive approach, In order to avoid the endoscopic burden, cost, drawbacks, unpleasant and repeated examinations to the patients. In our study, we aimed to evaluate the ability of this marker in the prediction of another complication of portal hypertension, which is portal hypertensive gastropathy (PHG), the one that is diagnosed also by endoscopic tools. Patients and methods: It is about a prospective study, which include 124 cirrhotic patients with no history of bleeding who underwent screening endoscopy for PH-related complications like esophageal varices (EVs) and PHG. Routine biological tests were performed as well as the VWF-Ag testing by both ELFA and Immunoturbidimetric techniques. The diagnostic performance of our marker was assessed using sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and receiver operating characteristic curves. Results: 124 patients were enrolled in this study, with a mean age of 58 years [CI: 55 – 60 years] and a sex ratio of 1.17. Viral etiologies were found in 50% of patients. Screening endoscopy revealed the presence of PHG in 20.2% of cases, while for EVsthey were found in 83.1% of cases. VWF-Ag levels, were significantly increased in patients with PHG compared to those who have not: 441% [CI: 375 – 506], versus 279% [CI: 253 – 304], respectively (p <0.0001). Using the area under the receiver operating characteristic curve (AUC), vWF-Ag was a good predictor for the presence of PHG. With a value higher than 320% and an AUC of 0.824, VWF-Ag had an 84% sensitivity, 74% specificity, 44.7% positive predictive value, 94.8% negative predictive value, and 75.8% diagnostic accuracy. Conclusion: VWF-Ag is a good non-invasive low coast marker for excluding the presence of PHG in patients with liver cirrhosis. Using this marker as part of a selective screening strategy might reduce the need for endoscopic screening and the coast of the management of these kinds of patients.Keywords: von willebrand factor, portal hypertensive gastropathy, prediction, liver cirrhosis
Procedia PDF Downloads 2058266 Downregulation of Epidermal Growth Factor Receptor in Advanced Stage Laryngeal Squamous Cell Carcinoma
Authors: Sarocha Vivatvakin, Thanaporn Ratchataswan, Thiratest Leesutipornchai, Komkrit Ruangritchankul, Somboon Keelawat, Virachai Kerekhanjanarong, Patnarin Mahattanasakul, Saknan Bongsebandhu-Phubhakdi
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In this globalization era, much attention has been drawn to various molecular biomarkers, which may have the potential to predict the progression of cancer. Epidermal growth factor receptor (EGFR) is the classic member of the ErbB family of membrane-associated intrinsic tyrosine kinase receptors. EGFR expression was found in several organs throughout the body as its roles involve in the regulation of cell proliferation, survival, and differentiation in normal physiologic conditions. However, anomalous expression, whether over- or under-expression is believed to be the underlying mechanism of pathologic conditions, including carcinogenesis. Even though numerous discussions regarding the EGFR as a prognostic tool in head and neck cancer have been established, the consensus has not yet been met. The aims of the present study are to assess the correlation between the level of EGFR expression and demographic data as well as clinicopathological features and to evaluate the ability of EGFR as a reliable prognostic marker. Furthermore, another aim of this study is to investigate the probable pathophysiology that explains the finding results. This retrospective study included 30 squamous cell laryngeal carcinoma patients treated at King Chulalongkorn Memorial Hospital from January 1, 2000, to December 31, 2004. EGFR expression level was observed to be significantly downregulated with the progression of the laryngeal cancer stage. (one way ANOVA, p = 0.001) A statistically significant lower EGFR expression in the late stage of the disease compared to the early stage was recorded. (unpaired t-test, p = 0.041) EGFR overexpression also showed the tendency to increase recurrence of cancer (unpaired t-test, p = 0.128). A significant downregulation of EGFR expression was documented in advanced stage laryngeal cancer. The results indicated that EGFR level correlates to prognosis in term of stage progression. Thus, EGFR expression might be used as a prevailing biomarker for laryngeal squamous cell carcinoma prognostic prediction.Keywords: downregulation, epidermal growth factor receptor, immunohistochemistry, laryngeal squamous cell carcinoma
Procedia PDF Downloads 1118265 Inactivation of Rhodotorula spp. 74 with Cold Atmospheric Plasma
Authors: Zoran Herceg, Višnja Stulić, Tomislava Vukušić, Anet Režek Jambrak
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High voltage electrical discharge is a new technology used for inactivation of pathogen microorganisms. Pathogen yeasts can cause diseases in humans if they are ingested. Nowadays new technologies have become the focus of researching all over the world. Rhodotorula is known as yeast that can cause diseases in humans. The aim of this study was to examine whether the high voltage electrical discharge treatment generated in gas phase has an influence on yeast reduction and recovery of Rhodotorula spp 74 in pure culture. Rhodotorula spp. 74 was treated in 200 mL of model solution. Treatment time (5 and 10 min), frequency (60 and 90 Hz) and injected gas (air or argon 99,99%) were changed. Titanium high voltage needle was used as high voltage electrode (positive polarity) through which air or argon was injected at the gas flow of 0.6 L/min. Experimental design and statistical analyses were obtained by Statgraphics Centurion software (StatPoint Technologies, Inc., VA, USA). The best inactivation rate 1.7 log10 reduction was observed after the 10 min of treatment, frequency of 90 Hz and injected air. Also with a longer treatment time inactivation rate was higher. After the 24 h recovery of treated samples was observed. Therefore the further optimization of method is needed to understand the mechanism of yeasts inactivation and cells recovery after the treatment. Acknowledgements: The authors would like to acknowledge the support by Croatian Science Foundation and research project ‘Application of electrical discharge plasma for preservation of liquid foods’.Keywords: rhodotorula spp. 74, electrical discharge plasma, inactivation, stress response
Procedia PDF Downloads 2378264 Simulation of the Flow in a Circular Vertical Spillway Using a Numerical Model
Authors: Mohammad Zamani, Ramin Mansouri
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Spillways are one of the most important hydraulic structures of dams that provide the stability of the dam and downstream areas at the time of flood. A circular vertical spillway with various inlet forms is very effective when there is not enough space for the other spillway. Hydraulic flow in a vertical circular spillway is divided into three groups: free, orifice, and under pressure (submerged). In this research, the hydraulic flow characteristics of a Circular Vertical Spillway are investigated with the CFD model. Two-dimensional unsteady RANS equations were solved numerically using Finite Volume Method. The PISO scheme was applied for the velocity-pressure coupling. The mostly used two-equation turbulence models, k-ε and k-ω, were chosen to model Reynolds shear stress term. The power law scheme was used for the discretization of momentum, k, ε, and ω equations. The VOF method (geometrically reconstruction algorithm) was adopted for interface simulation. In this study, three types of computational grids (coarse, intermediate, and fine) were used to discriminate the simulation environment. In order to simulate the flow, the k-ε (Standard, RNG, Realizable) and k-ω (standard and SST) models were used. Also, in order to find the best wall function, two types, standard wall, and non-equilibrium wall function, were investigated. The laminar model did not produce satisfactory flow depth and velocity along the Morning-Glory spillway. The results of the most commonly used two-equation turbulence models (k-ε and k-ω) were identical. Furthermore, the standard wall function produced better results compared to the non-equilibrium wall function. Thus, for other simulations, the standard k-ε with the standard wall function was preferred. The comparison criterion in this study is also the trajectory profile of jet water. The results show that the fine computational grid, the input speed condition for the flow input boundary, and the output pressure for the boundaries that are in contact with the air provide the best possible results. Also, the standard wall function is chosen for the effect of the wall function, and the turbulent model k-ε (Standard) has the most consistent results with experimental results. When the jet gets closer to the end of the basin, the computational results increase with the numerical results of their differences. The mesh with 10602 nodes, turbulent model k-ε standard and the standard wall function, provide the best results for modeling the flow in a vertical circular Spillway. There was a good agreement between numerical and experimental results in the upper and lower nappe profiles. In the study of water level over crest and discharge, in low water levels, the results of numerical modeling are good agreement with the experimental, but with the increasing water level, the difference between the numerical and experimental discharge is more. In the study of the flow coefficient, by decreasing in P/R ratio, the difference between the numerical and experimental result increases.Keywords: circular vertical, spillway, numerical model, boundary conditions
Procedia PDF Downloads 868263 Implications of Fuel Reloading in Heterogeneous Thorium-Based Fuel Designs for Improved Fuel Cycle Characteristics
Authors: Hendrik Bernard Van Der Walt, Frik Van Niekerk
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Fuel models render a reduction in BOL when thorium is added to a reactor core. Thorium emulates the role of a fertile poison, and is beneficial for reducing beginning of cycle (BOC) excess reactivity. In spite of the build-up of 233U over the duration of a fuel cycle, the effects of fuel reloading have a significant impact on fuel viability, especially in the case of heterogeneous thorium-based fuels. The most common practice of compensating for the reduction of BOC reactivity is the addition of fissile isotopes (uranium fuel with increased enrichment or plutonium). This study introduces a heterogeneous thorium-based fuel with minimal fissile isotope additions. A pseudo reloading scheme was developed for numerical simulations of an infinite reactor based on the North-Anna 1 reactor operating in Virginia, USA. Use of this reloading pattern allows new thorium-based fuel to be loaded into the reactor model as part of a phasing in strategy at the end of any conventional reactor cycle. Results demonstrate the effects of thorium-based fuel on fuel cycle characteristics such as fuel cycle length, neutron economy and material matrix. Application of the above mentioned approach delivered promising results and presents a heterogeneous thorium-based fuel which could replace conventional fuel of typical, currently operating (or future) reactors without the need for expensive reactor redesign or fuel recycling strategies.Keywords: nuclear fuel, nuclear characteristics, nuclear fuel cycle, thorium-based fuel, heterogeneous design, fuel reloading
Procedia PDF Downloads 1358262 Sound Noise Control of a Steam Ejector in a Typical Power Plant: Design, Manufacturing, and Testing a Silencer-Muffler
Authors: Ali Siami, Masoud Asayesh, Asghar Najafi, Amirhosein Hamedanian
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There are so many noise sources in power generation units that these sources can produce high-level sound noise. Therefore, sound noise reduction methods can assist these industries, especially in these days that laws related to environmental issues become more strict. In a typical power plant, so many machines and devices with high-level sound noise are arranged beside of each others. Therefore, the sound source identification and reducing the noise level can be very vital. In this paper, the procedure for designing, manufacturing and testing of a silencer-muffler used for a power plant steam vent is mentioned. This unit is placed near the residential area and so it is very important to reduce the noise emission. For this purpose, in the first step, measurements have done to identify the sound source and the frequency content of noise. The overall level of noise was so high and it was more than 120dB. Then, the appropriate noise control device is designed according to the measurement results and operational conditions. In the next step, the designed silencer-muffler has been manufactured and installed on the steam discharge of the ejector. For validation of the silencer-muffler effect, the acoustic test was done again in operating mode. Finally, the measurement results before and after the installation are compared. The results have confirmed a considerable reduction in noise level resultant of using silencer-muffler in the designed frequency range.Keywords: silencer-muffler, sound noise control, sound measurement, steam ejector
Procedia PDF Downloads 3848261 Mixed Traffic Speed–Flow Behavior under Influence of Road Side Friction and Non-Motorized Vehicles: A Comparative Study of Arterial Roads in India
Authors: Chetan R. Patel, G. J. Joshi
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The present study is carried out on six lane divided urban arterial road in Patna and Pune city of India. Both the road having distinct differences in terms of the vehicle composition and the road side parking. Arterial road in Patan city has 33% of non-motorized mode, whereas Pune arterial road dominated by 65% of Two wheeler. Also road side parking is observed in Patna city. The field studies using vidiographic techniques are carried out for traffic data collection. Data are extracted for one minute duration for vehicle composition, speed variation and flow rate on selected arterial road of the two cities. Speed flow relationship is developed and capacity is determine. Equivalency factor in terms of dynamic car unit is determine to represent the vehicle is single unit. The variation in the capacity due to side friction, presence of non motorized traffic and effective utilization of lane width is compared at concluding remarks.Keywords: arterial road, capacity, dynamic equivalency factor, effect of non motorized mode, side friction
Procedia PDF Downloads 3488260 Prevalence of Seropositivity for Cytomegalovirus in Patients with Hereditary Bleeding Diseases in West Azerbaijan of Iran
Authors: Zakieh Rostamzadeh, Zahra Shirmohammadi
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Human cytomegalovirus is a species of the cytomegalovirus family of viruses, which in turn is a member of the viral family known as herpesviridae or herpesviruses. Although they may be found throughout the body, HCMV infections are frequently associated with the salivary glands. HCMV infection is typically unnoticed in healthy people, but can be life-threatening for the immunocompromised such as HIV-infected persons, organ transplant recipients, or newborn infants. After infection, HCMV has an ability to remain latent within the body over long periods. Cytomegalovirus (CMV) causes infection in immunocompromised, hemophilia patients and those who received blood transfusion frequently. This study aimed at determining the prevalence of cytomegalovirus (CMV) antibodies in hemophilia patients. Materials and Methods: A retrospective observational study was carried out in Urmia, North West of Iran. The study population comprised a sample of 50 hemophilic patients born after 1985 and have received blood factors in West Azerbaijan. The exclusion criteria include: drug abusing, high risk sexual contacts, vertical transmission of mother to fetus and suspicious needling. All samples were evaluated with the method of ELISA, with a certain kind of kit and by a certain laboratory. Results: Fifty hemophiliacs from 250 patients registered with Urmia Hemophilia Society were enrolled in the study including 43 (86%) male, and 7 (14%) female. The mean age of patients was 10.3 years, range 3 to 25 years. None of patients had risk factors mentioned above. Among our studied population, 34(68%) had hemophilia A, 1 (2%) hemophilia B, 8 (16%) VWF, 3(6%) factor VII deficiency, 1 (2%) factor V deficiency, 1 (2%) factor X deficiency, 1 (2%). Sera of 50 Hemodialysis patients were investigated for CMV-specific immunoglobulin G (IgG) and IgM. % 91.89 patients were anti-CMV IgG positive and %40.54 was seropositive for anti-CMV IgM. 37.8% patient had serological evidence of reactivation and 2.7% of patients had the primary infection. Discussion: There was no relationship between the antibody titer and: drug abusing, high risk sexual contacts, vertical transmission of mother to fetus and suspicious needling.Keywords: bioinformatics, biomedicine, cytomegalovirus, immunocompromise
Procedia PDF Downloads 3588259 An Investigation of Interdisciplinary Techniques for Assessment of Water Quality in an Industrial Area
Authors: Priti Saha, Biswajit Paul
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Rapid urbanization and industrialization have increased the demand of groundwater. However, the present era has evident an enormous level of groundwater pollution. Therefore, water quality assessment is paramount importance to evaluate its suitability for drinking, irrigation and industrial use. This study focus to evaluate the groundwater quality of an industrial city in eastern India through interdisciplinary techniques. The multi-purpose Water Quality Index (WQI) assess the suitability for drinking as well as irrigation of forty sampling locations, where 2.5% and 15% of sampling locations have excellent water quality (WQI:0-25) as well as 15% and 40% have good quality (WQI:25-50), which represents its suitability for drinking and irrigation respectively. However, the industrial water quality was assessed through Ryznar Stability Index (LSI), which affirmed that only 2.5% of sampling locations have neither corrosive nor scale forming properties (RSI: 6.2-6.8). These techniques with the integration of geographical information system (GIS) for spatial assessment indorsed its effectiveness to identify the regions where the water bodies are suitable to use for drinking, irrigation as well as industrial activities. Further, the sources of these contaminants were identified through factor analysis (FA), which revealed that both the geogenic as well as anthropogenic sources were responsible for groundwater pollution. This research demonstrates the effectiveness of statistical and GIS techniques for the analysis of environmental contaminants.Keywords: groundwater, water quality analysis, water quality index, WQI, factor analysis, FA, spatial assessment
Procedia PDF Downloads 1958258 Sea Cucumber (Stichopus chloronotus) to Expedite Healing of Minor Wounds
Authors: Isa Naina Mohamed, Mazliadiyana Mazlan, Ahmad Nazrun Shuid
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Stichopus chloronotus (Black Knobby or green fish) is a sea cucumber species commonly found along Malaysia’s coastline. In Malaysia, it is believed that sea cucumber can expedite healing of wounds, provide extra energy and used as an ointment to relieve pain. The aim of this study is to determine the best concentration of Stichopus chlronotus extract to promote wound healing. 12 male Sprague-Dawley rats with wounds created using 6mm disposable punch biopsy were divided into 6 treatment groups. The normal control group (untreated), positive control group (flavin treated only), negative control group (emulsifying ointment only), and group 0.1, group 0.5, group 1 were each treated with 0.1%, 0.5% and 1% of Stichopus chlronotus water extract mixed in emulsifying ointment, respectively. Treatments were administered topically for 10 days. Changes in wound area were measured using caliper and photographs were taken on day 2, 4, 6, 8, and 10 after index wound. Results showed that wound reduction of group 0.5 on day 4, 6, and 8 was significantly higher compared to normal control group and positive control group. Group 0.5 also had higher wound reduction from day 6 until day 10 compared to all other groups. In conclusion, Sea Cucumber (Stichopus chloronotus) extract demonstrated the best minor wound healing properties at concentration 0.5%. The potential of Stichopus chlronotus extract ointment for wound healing shall be investigated further.Keywords: minor wound healing, expedite wound healing, sea cucumber, Stichopus chloronotus
Procedia PDF Downloads 3948257 The Ludic Exception and the Permanent Emergency: Understanding the Emergency Regimes with the Concept of Play
Authors: Mete Ulaş Aksoy
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In contemporary politics, the state of emergency has become a permanent and salient feature of politics. This study aims to clarify the anthropological and ontological dimensions of the permanent state of emergency. It pays special attention to the structural relation between the exception and play. Focusing on the play in the context of emergency and exception enables the recognition of the difference and sometimes the discrepancy between the exception and emergency, which has passed into oblivion because of the frequency and normalization of emergency situations. This study coins the term “ludic exception” in order to highlight the difference between the exceptions in which exuberance and paroxysm rule over the socio-political life and the permanent emergency that protects the authority with a sort of extra-legality. The main thesis of the study is that the ludic elements such as risk, conspicuous consumption, sacrificial gestures, agonism, etc. circumscribe the exceptional moments temporarily, preventing them from being routine and normal. The study also emphasizes the decline of ludic elements in modernity as the main factor in the transformation of the exceptions into permanent emergency situations. In the introduction, the relationship between play and exception is taken into consideration. In the second part, the study elucidates the concept of ludic exceptions and dwells on the anthropological examples of the ludic exceptions. In the last part, the decline of ludic elements in modernity is addressed as the main factor for the permanent emergency.Keywords: emergency, exception, ludic exception, play, sovereignty
Procedia PDF Downloads 908256 Breast Cancer in Very Young (Less Than 25 Yeras) Women: An Institutional Analysis from Developing Country
Authors: Ajay Gogia, Svs Deo, Dn Sharma, Atul Batra, Ashutash Mishra
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Background and Aims: Breast cancer in women aged less than 25 years (defined as very young breast cancer, VYBC) is rare and accounts for 0.25% of all breast cancer in the West. There is no data available on VYBC from developing countries. The aim of this study was to analyze the clinical, pathological, and prognostic factors and outcomes in VYBC. Methods: This retrospective analysis was performed on 80 patients aged 25 years or less (screened 8000 files of female BC) who were registered at All India Institute of Medical Sciences (AIIMS), New Delhi, India, over a 15-year period between 2011 and 2023. Results: The median age was 21.5 years (range 16-25). A positive family history (siblings and parents) was elicited in 30% of cases, and breast cancer gene (BRCA1/2) mutation was found in 33% of cases patients. Ten patients (12.5%) patients have pregnancy-associated breast cancer (BC detected during pregnancy or 1 year after postpartum period). The TNM stage distribution was Stage I was 0, stage II -30%, stage III –60% and Stage IV -10 %patients. Seventy percent of tumors were high grade, and 90% had pathological node-positive disease. Estrogen, Progesterone, and human epidermal growth factor receptor 2 (HER2)/neu positivity were 25%,25% and 35%, respectively. Triple-negative breast cancer constituted 40% of patients. With a median follow-up of 42 months, 3 years, relapse-free survival (nonmetastatic disease), progression-free survival (metastatic disease) and overall survival were 30%, 15% and 50%, respectively. Conclusions: Very young women constituted 1% of all breast cancer cases. Advanced disease at presentation and high-risk pathological features result in poor outcomes. One-third of VYBCs are associated with BRCA mutation, which requires genetic counseling and risk reduction surgery if required. Due to the aggressive behavior of BC in this age group, need early diagnosis and prompt treatmentKeywords: very young, breast cancer, outcome, developing country, India
Procedia PDF Downloads 298255 Inflammatory Alleviation on Microglia Cells by an Apoptotic Mimicry
Authors: Yi-Feng Kao, Huey-Jine Chai, Chin-I Chang, Yi-Chen Chen, June-Ru Chen
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Microglia is a macrophage that resides in brain, and overactive microglia may result in brain neuron damage or inflammation. In this study, the phospholipids was extracted from squid skin and manufactured into a liposome (SQ liposome) to mimic apoptotic body. We then evaluated anti-inflammatory effects of SQ liposome on mouse microglial cell line (BV-2) by lipopolysaccharide (LPS) induction. First, the major phospholipid constituents in the squid skin extract were including 46.2% of phosphatidylcholine, 18.4% of phosphatidylethanolamine, 7.7% of phosphatidylserine, 3.5% of phosphatidylinositol, 4.9% of Lysophosphatidylcholine and 19.3% of other phospholipids by HPLC-UV analysis. The contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the squid skin extract were 11.8 and 28.7%, respectively. The microscopic images showed that microglia cells can engulf apoptotic cells or SQ-liposome. In cell based studies, there was no cytotoxicity to BV-2 as the concentration of SQ-liposome was less than 2.5 mg/mL. The LPS induced pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), were significant suppressed (P < 0.05) by pretreated 0.03~2.5mg/ml SQ liposome. Oppositely, the anti-inflammatory cytokines transforming growth factor-beta (TGF-β) and interleukin-10 (IL-10) secretion were enhanced (P < 0.05). The results suggested that SQ-liposome possess anti-inflammatory properties on BV-2 and may be a good strategy for against neuro-inflammatory disease.Keywords: apoptotic mimicry, neuroinflammation, microglia, squid processing by-products
Procedia PDF Downloads 4838254 Upsetting of Tri-Metallic St-Cu-Al and St-Cu60Zn-Al Cylindrical Billets
Authors: Isik Cetintav, Cenk Misirli, Yilmaz Can
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This work investigates upsetting of the tri-metallic cylindrical billets both experimentally and analytically with a reduction ratio 30%. Steel, brass, and copper are used for the outer and outmost rings and aluminum for the inner core. Two different models have been designed to show material flow and the cavity took place over the two interfaces during forming after this reduction ratio. Each model has an outmost ring material as steel. Model 1 has an outer ring between the outmost ring and the solid core material as copper and Model 2 has a material as brass. Solid core is aluminum for each model. Billets were upset in press machine by using parallel flat dies. Upsetting load was recorded and compared for models and single billets. To extend the tests and compare with experimental procedure to a wider range of inner core and outer ring geometries, finite element model was performed. ABAQUS software was used for the simulations. The aim is to show how contact between outmost ring, outer ring and the inner core are carried on throughout the upsetting process. Results have shown that, with changing in height, between outmost ring, outer ring and inner core, the Model 1 and Model 2 had very good interaction, and the contact surfaces of models had various interface behaviour. It is also observed that tri-metallic materials have lower weight but better mechanical properties than single materials. This can give an idea for using and producing these new materials for different purposes.Keywords: tri-metallic, upsetting, copper, brass, steel, aluminum
Procedia PDF Downloads 3428253 Comparative Functional Analysis of Two Major Sterol-Biosynthesis Regulating Transcription Factors, Hob1 and Sre1, in Pathogenic Cryptococcus Species Complex
Authors: Dong-Gi Lee, Suyeon Cha, Yong-Sun Bahn
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Sterol lipid is essential for cell membrane structure in eukaryotic cells. In mammalian cells, sterol regulatory element binding proteins (SREBPs) act as principal regulators of cellular cholesterol which is essential for proper cell membrane fluidity and structure. SREBP and sterol regulation are related to levels of cellular oxygen because it is a major substrate for sterol synthesis. Upon cellular sterol and oxygen levels are depleted, SREBP is translocated to the Golgi where it undergoes proteolytic cleavage of N terminus, then it travels to the nucleus to play a role as transcription factor. In yeast cells, synthesis of ergosterol is also highly oxygen consumptive, and Sre1 is a transcription factor known to play a central role in adaptation to growth under low oxygen condition and sterol homeostasis in Cryptococcus neoformans. In this study, we observed phenotypes in other strains of Cryptococcus species by constructing hob1Δ and sre1Δ mutants to confirm whether the functions of both genes are conserved in most serotypes. As a result, hob1Δ showed no noticeable phenotype under treatment of antifungal drugs and most environmental stresses in R265 (C. gattii) and XL280 (C. neoformans), suggesting that Hob1 is related to sterol regulation only in H99 (serotype A). On the other hand, the function of Sre1 was found to be conserved in most serotypes. Furthermore, mating experiment of hob1Δ or sre1Δ showed dramatic defects in serotype A (H99) and D (XL280). It revealed that Hob1 and Sre1 related to mating ability in Cryptococcus species, especially cell fusion efficiency. In conclusion, HOB1 and SRE1 play crucial role in regulating sterol-homeostasis and differentiation in C. neoformans, moreover, Hob1 is specific gene in Cryptococcus neoformans. It suggests that Hob1 is considered as potent factor-targeted new safety antifungal drug.Keywords: cryptococcus neoformans, Hob1, Sre1, sterol regulatory element binding proteins
Procedia PDF Downloads 2508252 Cluster Analysis and Benchmarking for Performance Optimization of a Pyrochlore Processing Unit
Authors: Ana C. R. P. Ferreira, Adriano H. P. Pereira
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Given the frequent variation of mineral properties throughout the Araxá pyrochlore deposit, even if a good homogenization work has been carried out before feeding the processing plants, an operation with quality and performance’s high variety standard is expected. These results could be improved and standardized if the blend composition parameters that most influence the processing route are determined, and then the types of raw materials are grouped by them, finally presenting a great reference with operational settings for each group. Associating the physical and chemical parameters of a unit operation through benchmarking or even an optimal reference of metallurgical recovery and product quality reflects in the reduction of the production costs, optimization of the mineral resource, and guarantee of greater stability in the subsequent processes of the production chain that uses the mineral of interest. Conducting a comprehensive exploratory data analysis to identify which characteristics of the ore are most relevant to the process route, associated with the use of Machine Learning algorithms for grouping the raw material (ore) and associating these with reference variables in the process’ benchmark is a reasonable alternative for the standardization and improvement of mineral processing units. Clustering methods through Decision Tree and K-Means were employed, associated with algorithms based on the theory of benchmarking, with criteria defined by the process team in order to reference the best adjustments for processing the ore piles of each cluster. A clean user interface was created to obtain the outputs of the created algorithm. The results were measured through the average time of adjustment and stabilization of the process after a new pile of homogenized ore enters the plant, as well as the average time needed to achieve the best processing result. Direct gains from the metallurgical recovery of the process were also measured. The results were promising, with a reduction in the adjustment time and stabilization when starting the processing of a new ore pile, as well as reaching the benchmark. Also noteworthy are the gains in metallurgical recovery, which reflect a significant saving in ore consumption and a consequent reduction in production costs, hence a more rational use of the tailings dams and life optimization of the mineral deposit.Keywords: mineral clustering, machine learning, process optimization, pyrochlore processing
Procedia PDF Downloads 1438251 Investigation of Existing Guidelines for Four-Legged Angular Telecommunication Tower
Authors: Sankara Ganesh Dhoopam, Phaneendra Aduri
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Lattice towers are light weight structures which are primarily governed by the effects of wind loading. Ensuring a precise assessment of wind loads on the tower structure, antennas, and associated equipment is vital for the safety and efficiency of tower design. Earlier, the Indian standards are not available for design of telecom towers. Instead, the industry conventionally relied on the general building wind loading standard for calculating loads on tower components and the transmission line tower design standard for designing the angular members of the towers. Subsequently, the Bureau of Indian Standards (BIS) revised these standards and angular member design standard. While the transmission line towers are designed using the above standard, a full-scale model test will be done to prove the design. Telecom angular towers are also designed using the same with overload factor/factor of safety without full scale tower model testing. General construction in steel design code is available with limit state design approach and is applicable to the design of general structures involving angles and tubes but not used for angle member design of towers. Recently, in response to the evolving industry needs, the Bureau of Indian Standards (BIS) introduced a new standard titled “Isolated Towers, Masts, and Poles using structural steel -Code of practice” for the design of telecom towers. This study focuses on a 40m four legged angular tower to compare loading calculations and member designs between old and new standards. Additionally, a comparative analysis aligning with the new code provisions with international loading and design standards with a specific focus on American standards has been carried out. This paper elaborates code-based provisions used for load and member design calculations, including the influence of "ka" area averaging factor introduced in new wind load case.Keywords: telecom, angular tower, PLS tower, GSM antenna, microwave antenna, IS 875(Part-3):2015, IS 802(Part-1/sec-2):2016, IS 800:2007, IS 17740:2022, ANSI/TIA-222G, ANSI/TIA-222H.
Procedia PDF Downloads 838250 Analysis of Energy Efficiency Behavior with the Use of Train Dynamics Simulator and Statistical Tools: Case Study of Vitoria Minas Railway, Brazil
Authors: Eric Wilson Santos Cabral, Marta Monteiro Da Costa Cruz, Fabio Luis Maciel Machado, Henrique Andrade, Rodrigo Pirola Pestana, Vivian Andrea Parreira
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The large variation in the price of diesel in Brazil directly affects the variable cost of companies operating in the transportation sector. In rail transport, the great challenge is to overcome the annual budget, cargo and ore transported with cost reduction in relation to previous years, becoming more efficient every year. Some effective measures are necessary to achieve the reduction of the liter ratio consumed by KTKB (Gross Ton per Kilometer multiplied by thousand). This acronym represents the indicator of energy efficiency of some railroads in the world. This study is divided into two parts: the first, to identify using statistical tools, part of the controlled variables in the railways, which have a correlation with the energy efficiency indicator, seeking to aid decision-making. The second, with the use of the train dynamics simulator, within scenarios defined in the operational reality of a railroad, seeks to optimize the train formations and the train stop model for the change of train drivers. With the completion of the study, companies in the rail sector are expected to be able to reduce some of their transportation costs.Keywords: railway transport, railway simulation, energy efficiency, fuel consumption
Procedia PDF Downloads 3358249 Environmental Impacts on the British Era Structures of Faisalabad-a Detailed Study of the Clock Tower of Faisalabad
Authors: Bazla Manzoor, Aqsa Yasin
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Pakistan is the country which is progressing by leaps and bounds through agricultural and industrial growth. The main area, which presents the largest income rate through industrial activities, is Faisalabad from the Province of Punjab. Faisalabad’s main occupations include agriculture and industry. As these sectors i.e. agriculture and industry is developing day by day, they are earning much income for the country and generating thousands of job vacancies. On one hand the city, i.e. Faisalabad is on the way of development through industrial growth, while on the other hand this industrial growth is producing a bad impact on the environment. In return, that damaged environment is affecting badly on the people and built environment. This research is chiefly based on one of the above-mentioned factors i.e. adverse environmental impacts on the built structures. Faisalabad is an old city, therefore; it is having many old structures especially from British Era. Many of those structures are still surviving and are functioning as the government, private and public buildings. However, these structures are getting in a poor condition with the passage of time due to bad maintenance and adverse environmental impacts. Bad maintenance is a factor, which can be controlled by financial assistance and management. The factor needs to be seriously considered is the other one i.e. adverse environmental impacts on British Era structures of the city because this factor requires controlled and refined human activities and actions. For this reason, a research was required to conserve the British Era structures of Faisalabad so that these structures can function well. The other reason to conserve them is that these structures are historically important and are the heritage of the city. For doing this research, literature has been reviewed which was present in the libraries of the city. Department of Environment, Town Municipal Administration, Faisalabad Development Authority and Lyallpur Heritage Foundation were visited to collect the existing data available. Various British Era structures were also visited to note down the environmental impacts on them. From all the structures “Clock Tower,” was deeply studied as it is one of the oldest and most important heritage structures of the city because the earlier settlements of the city were planned based on its location by The British Government. The architectural and environmental analyses were done for The Clock Tower. This research study found the deterioration factors of the tower according to which suggestions have been made.Keywords: lyallpur, heritage, architecture, environment
Procedia PDF Downloads 3028248 Peformance of Bali Cattles Fed with Various Levels of Oil Palm Frond Ammoniated
Authors: Mardiati Zain, Ryanto Khasrad, I. Elihasridas, J. Juliantoni
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The research objective was to determine the productivity of cattle fed a complete ration with ammoniated based of oil palm-frond supplemented by Rumen Microbes Growth Factor (RMGF). The research used Randomized Block Design applying 4 rations as treatment and 4 groups cattle. The treatments were: A (60% oil palm frond ammoniated + 40% concentrate + RMGF); B (50% oil palm frond ammoniated + 50% concentrate + RMGF); C (40% oil palm frond ammoniated + 60% concentrate + RMGF); and D (30% oil palm frond ammoniated + 70% concentrate + RMGF). The measured parameters were dry matter (DM) and organic matter (OM) intake, daily weight gain (DWG), feed efficiency, total digestible nutrient (TDN), and digestibility of crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose, hemicellulose. Statistical analysis showed that the treatment had no significant effect (P > 0.05) on DM intake, OM intake, daily weight gain, feed efficiency, digestibility of DM, OM, CP, TDN, NDF, hemicellulose but had a highly significant effect (P < 0.01) on digestibility of ADF and cellulose. All treatments with different ratio (oil palm frond ammoniated: concentrate : RMGF) had no different effect on cattle productivities.Keywords: oil palm frond ammoniated, digestibility, rumen microba growth factor, Bali cattle
Procedia PDF Downloads 3878247 Cognitive Mechanisms of Mindfulness-Based Cognitive Therapy on Depressed Older Adults: The Mediating Role of Rumination and Autobiographical Memory Specificity
Authors: Wai Yan Shih, Sau Man Wong, Wing Chung Chang, Wai Chi Chan
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Background: Late-life depression is associated with significant consequences. Although symptomatic reduction is achievable through pharmacological interventions, older adults are more vulnerable to the side effects than their younger counterparts. In addition, drugs do not address underlying cognitive dysfunctions such as rumination and reduced autobiographical memory specificity (AMS), both shown to be maladaptive coping styles that are associated with a poorer prognosis in depression. Considering how aging is accompanied by cognitive, psychological and physical changes, the interplay of these age-related factors may potentially aggravate and interfere with these depressive cognitive dysfunctions in late-life depression. Special care should, therefore, be drawn to ensure these cognitive dysfunctions are adequately addressed. Aim: This randomized controlled trial aims to examine the effect of mindfulness-based cognitive therapy (MBCT) on depressed older adults, and whether the potential benefits of MBCT are mediated by improvements in rumination and AMS. Method: Fifty-seven participants with an average age of 70 years old were recruited from multiple elderly centers and online mailing lists. Participants were assessed with: (1) Hamilton depression scale, (2) ruminative response scale, (3) autobiographical memory test, (4) mindful attention awareness scale, and (5) Montreal cognitive assessment. Eligible participants with mild to moderate depressive symptoms and normal cognitive functioning were randomly allocated to an 8-week MBCT group or active control group consisting of a low-intensity exercise program and health education. Post-intervention assessments were conducted after the 8-week program. Ethics approval was given by the Institutional Review Board of the University of Hong Kong/Hospital Authority. Results: Mixed-factorials ANOVAs demonstrated significant time x group interaction effects for depressive symptoms, AMS, and dispositional mindfulness. A marginally significant interaction effect was found for rumination. Simple effect analyses revealed a significant reduction in depressive symptoms for the both the MBCT group (mean difference = 7.1, p = .000), and control group (mean difference = 2.7, p = .023). However, only participants in the MBCT group demonstrated improvements in rumination, AMS, and dispositional mindfulness. Bootstrapping-based mediation analyses showed that the effect of MBCT in alleviating depressive symptoms was only mediated by the reduction in rumination. Conclusions: The findings support the use of MBCT as an effective intervention for depressed older adults, considering the improvements in depressive symptoms, rumination, AMS and dispositional mindfulness despite their age. Reduction in ruminative tendencies plays a major role in the cognitive mechanism of MBCT.Keywords: mindfulness-based cognitive therapy, depression, older adults, rumination, autobiographical memory specificity
Procedia PDF Downloads 2118246 Comparing Student Performance on Standardized Tests at Test Center versus through Online-Proctored Delivery
Authors: Jin Koo
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The main purpose of this study is to investigate the comparability of student scores obtained from Test Center (TC) vs. Online-Proctored (OP) Delivery in the three subject areas of Verbal, Reading, and Mathematics for each level (Middle and Upper). Also, this study examines whether there is an interaction effect between test deliveries (TC vs. OP) and gender/ethnicity/ability level in each subject area. The test used in this study is a multiple-choice standardized test for students in grades 5-11. For this study, data were collected during the 2022-23 test administration. This research used a one-factor between-subjects ANOVA and Cohen’s d to compare the TC and OP groups’ test means for each level and each subject area. Also, 2-factor between-subjects ANOVAs were conducted to investigate examinee characteristics: gender (male and female), ethnicity (African-American, Asian, Hispanic, Multi-racial, and White), and ability level (low, average, and high-ability groups). The author found that students’ test scores in some subject areas varied between TC and OP test deliveries by gender, ethnicity, and ability level, meaning that gender, ethnicity, and ability level were related to the score difference. These results will be discussed according to the current testing systems.Keywords: ability level, ethnicity, gender, online-proctored delivery, standardized test, test center
Procedia PDF Downloads 558245 Understanding Factor Influence in Mask-Wearing Intention Onboard Airplanes during COVID-19: Attitude as a Mediator
Authors: Jing Yu Pan, Dahai Liu
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Airlines in the US have taken protective measures to battle the COVID-19 pandemic, with a mask mandate being the most important one, especially in the aircraft cabin. As the industry is recovering from the pandemic, mask-wearing will eventually become a personal choice during flight. Nevertheless, COVID-19 will continue to create uncertainty for a long time into the future, making it necessary to understand the attitude and voluntary use of masks by air travelers on airplanes even after masks are no longer mandatory. This study aimed to understand the relationship between demographic characteristics and mask-wearing intention in the US. For age, gender, income, educational, and ethnicity groups, this study examined three factors – subjective norms, risk avoidance, and information seeking and their influence on the mask-wearing intention onboard airplanes during COVID-19 and whether or not attitude toward masks was an important mediator. The results show that all demographic factors except gender could help to explain the group variations in factor impact and the mediating effect in mask-wearing intentions. In particular, Asian travelers had mask-wearing intentions that were not affected by attitude either directly or indirectly. These findings provide useful implications to enhance the health and safety of air travelers, especially in the US, where opposing views toward mask-wearing still widely exist.Keywords: COVID-19, passenger demographics, aircraft cabin, mask-wearing intention, attitude as mediator
Procedia PDF Downloads 898244 A Fuzzy-Rough Feature Selection Based on Binary Shuffled Frog Leaping Algorithm
Authors: Javad Rahimipour Anaraki, Saeed Samet, Mahdi Eftekhari, Chang Wook Ahn
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Feature selection and attribute reduction are crucial problems, and widely used techniques in the field of machine learning, data mining and pattern recognition to overcome the well-known phenomenon of the Curse of Dimensionality. This paper presents a feature selection method that efficiently carries out attribute reduction, thereby selecting the most informative features of a dataset. It consists of two components: 1) a measure for feature subset evaluation, and 2) a search strategy. For the evaluation measure, we have employed the fuzzy-rough dependency degree (FRFDD) of the lower approximation-based fuzzy-rough feature selection (L-FRFS) due to its effectiveness in feature selection. As for the search strategy, a modified version of a binary shuffled frog leaping algorithm is proposed (B-SFLA). The proposed feature selection method is obtained by hybridizing the B-SFLA with the FRDD. Nine classifiers have been employed to compare the proposed approach with several existing methods over twenty two datasets, including nine high dimensional and large ones, from the UCI repository. The experimental results demonstrate that the B-SFLA approach significantly outperforms other metaheuristic methods in terms of the number of selected features and the classification accuracy.Keywords: binary shuffled frog leaping algorithm, feature selection, fuzzy-rough set, minimal reduct
Procedia PDF Downloads 2268243 A First-Principles Molecular Dynamics Study on Li+ Solvation Structures in THF/MTHF Containing Electrolytes for Lithium Metal Batteries.
Authors: Chiu-Neng Su, Santhanamoorthi Nachimuthu, Jyh-Chiang Jiang
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In lithium-ion batteries (LIBs) the solid–electrolyte interphase (SEI) layer, which forms on the anode surface, plays a crucial role in stabilizing battery performance. Over the past two decades, efforts to enhance LIB electrolytes have primarily focused on refining the quality of SEI components. Despite these endeavors, several observed phenomena remain inadequately improved the SEI layer. Consequently, there has been a significant surge in research interest regarding the behavior of electrolyte solvation structures to elucidate improvements in battery performance. Thus, in this study, we aimed to explore the solvation structures of LiPF₆ in a mixture of organic solvents, tetrahydrofuran (THF) and 2-methyl-tetrahydrofuran (MTHF) using ab-initio molecular dynamics (AIMD) simulations. Our work investigated the solvation structure of electrolytes with different salt concentrations: low-concentration electrolyte (1.0M LiPF6 in 1:1v/v mixture of THF and MTHF), and high-concentration electrolyte (2.0M LiPF₆ in 1:1v/v mixture of THF and MTHF) and compared them with that of conventional electrolyte (1.0M LiPF₆ in 1:1v/v mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC)). Furthermore, the reduction stability of Li+ solvation structures in these electrolyte systems are investigated. It is found that the first solvation shell of Li+ primary consists of THF. We also analyzed the molecular orbital energy levels to understand the reducing stability of these solvents. Compared with the solvation sheath of commercial electrolyte, the THF/MTHF-containing electrolytes have a higher lowest unoccupied molecular orbital (LUMO) energy level, resulting in improved reduction and interface stability. It has been shown that Li-Al alloy can significantly improve cycle life and promote the formation of a dense SEI layer. Therefore, this study aims to construct the solvation structures obtained from calculations of the pure electrolyte system on the surface of Al-Li alloy. Additionally, AIMD simulations will be conducted to investigate chemical reactions at the interface. This investigation aims to elucidate the composition of the SEI layer formed. Furthermore, Bader charges are used to determine the origin and flow of electrons, thereby revealing the sequence of reduction reactions for generating SEI layers.Keywords: lithium, aluminum, alloy, battery, solvation structure
Procedia PDF Downloads 238242 Perception of Indoor Environmental Qualities in Residential Buildings: A Quantitative Case Survey for Turkey and Iran
Authors: Majid Bahramian, Kaan Yetilmezsoy
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Environmental performance of residential buildings been a hotspot for the research community, however, the indoor environmental quality significantly overlooked in the literature. The paper is motivated by the understanding of the occupants from the indoor environmental qualities and seeks to find the satisfaction level in two high-rise green-certified residential buildings. Views of more than 250 respondents in each building were solicited on 15 Indoor Environmental Qualities (IEQ) parameters. Findings suggest that occupants are generally satisfied with five critical aspects of IEQ, but some unsatisfaction exists during operation phase. The results also indicate that the green build certification systems for new buildings have some deficiencies which affect the actual environmental performance of green buildings during operation. Some reasons were suggested by the occupants of which the design-focus construction and lack of monitoring after certification were the most critical factors. Among the crucial criteria for environmental performance assessment of green buildings, energy saving, reduction of Greenhouse Gases (GHG) emissions, environmental impacts on neighborhood area, waste reduction and IEQs, were the most critical factors dominating the performance, in a descending order. This study provides valuable information on the performance of IEQ parameters of green building and gives a deeper understanding for stakeholders and companies involved in construction sector with the relevant feedback for their decision-making on current and future projects.Keywords: indoor environmental qualities, green buildings, occupant satisfaction, environmental performance
Procedia PDF Downloads 878241 Controlled Synthesis of Pt₃Sn-SnOx/C Electrocatalysts for Polymer Electrolyte Membrane Fuel Cells
Authors: Dorottya Guban, Irina Borbath, Istvan Bakos, Peter Nemeth, Andras Tompos
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One of the greatest challenges of the implementation of polymer electrolyte membrane fuel cells (PEMFCs) is to find active and durable electrocatalysts. The cell performance is always limited by the oxygen reduction reaction (ORR) on the cathode since it is at least 6 orders of magnitude slower than the hydrogen oxidation on the anode. Therefore high loading of Pt is required. Catalyst corrosion is also more significant on the cathode, especially in case of mobile applications, where rapid changes of loading have to be tolerated. Pt-Sn bulk alloys and SnO2-decorated Pt3Sn nanostructures are among the most studied bimetallic systems for fuel cell applications. Exclusive formation of supported Sn-Pt alloy phases with different Pt/Sn ratios can be achieved by using controlled surface reactions (CSRs) between hydrogen adsorbed on Pt sites and tetraethyl tin. In this contribution our results for commercial and a home-made 20 wt.% Pt/C catalysts modified by tin anchoring via CSRs are presented. The parent Pt/C catalysts were synthesized by modified NaBH4-assisted ethylene-glycol reduction method using ethanol as a solvent, which resulted either in dispersed and highly stable Pt nanoparticles or evenly distributed raspberry-like agglomerates according to the chosen synthesis parameters. The 20 wt.% Pt/C catalysts prepared that way showed improved electrocatalytic performance in the ORR and stability in comparison to the commercial 20 wt.% Pt/C catalysts. Then, in order to obtain Sn-Pt/C catalysts with Pt/Sn= 3 ratio, the Pt/C catalysts were modified with tetraethyl tin (SnEt4) using three and five consecutive tin anchoring periods. According to in situ XPS studies in case of catalysts with highly dispersed Pt nanoparticles, pre-treatment in hydrogen even at 170°C resulted in complete reduction of the ionic tin to Sn0. No evidence of the presence of SnO2 phase was found by means of the XRD and EDS analysis. These results demonstrate that the method of CSRs is a powerful tool to create Pt-Sn bimetallic nanoparticles exclusively, without tin deposition onto the carbon support. On the contrary, the XPS results revealed that the tin-modified catalysts with raspberry-like Pt agglomerates always contained a fraction of non-reducible tin oxide. At the same time, they showed increased activity and long-term stability in the ORR than Pt/C, which was assigned to the presence of SnO2 in close proximity/contact with Pt-Sn alloy phase. It has been demonstrated that the content and dispersion of the fcc Pt3Sn phase within the electrocatalysts can be controlled by tuning the reaction conditions of CSRs. The bimetallic catalysts displayed an outstanding performance in the ORR. The preparation of a highly dispersed 20Pt/C catalyst permits to decrease the Pt content without relevant decline in the electrocatalytic performance of the catalysts.Keywords: anode catalyst, cathode catalyst, controlled surface reactions, oxygen reduction reaction, PtSn/C electrocatalyst
Procedia PDF Downloads 2358240 Exploring Exposed Political Economy in Disaster Risk Reduction Efforts in Bangladesh
Authors: Shafiqul Islam, Cordia Chu
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Bangladesh is one of the most vulnerable countries to climate related disasters such as flood and cyclone. Exploring from the semi-structured in-depth interviews of 38 stakeholders and literature review, this study examined the public spending distribution process in DRR. This paper demonstrates how the processes of political economy-enclosure, exclusion, encroachment, and entrenchment hinder the Disaster Risk Reduction (DRR) efforts of Department of Disaster Management (DDM) such as distribution of flood centres, cyclone centres and 40 days employment generation programs. Enclosure refers to when DRR projects allocated to less vulnerable areas or expand the roles of influencing actors into the public sphere. Exclusion refers to when DRR projects limit affected people’s access to resources or marginalize particular stakeholders in decision-making activities. Encroachment refers to when allocation of DRR projects and selection of location and issues degrade the environmental affect or contribute to other forms of disaster risk. Entrenchment refers to when DRR projects aggravate the disempowerment of common people worsen the concentrations of wealth and income inequality within a community. In line with United Nations (UN) Sustainable Development Goals (SDGs), Hyogo and Sendai Frameworks, in the case of Bangladesh, DRR policies implemented under the country’s national five-year plan, disaster-related acts and rules. These policies and practices have somehow enabled influential-elites to mobilize and distribute resources through bureaucracies. Exclusionary forms of fund distribution of DRR exist at both the national and local scales. DRR related allocations have encroached through the low land areas development project without consulting local needs. Most severely, DRR related unequal allocations have entrenched social class trapping the backward communities vulnerable to climate related disasters. Planners and practitioners of DRR need to take necessary steps to eliminate the potential risks from the processes of enclosure, exclusion, encroachment, and entrenchment happens in project fund allocations.Keywords: Bangladesh, disaster risk reduction, fund distribution, political economy
Procedia PDF Downloads 1308239 Interactive of Calcium, Potassium, and Dynamic Unequal Salt Distribution on the Growth of Tomato in Hydroponic System
Authors: Mohammad Koushafar, Amir Hossein Khoshgoftarmanesh
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Due to water shortage, application of saline water for irrigation is an urgent requirement in agriculture. Thus, this study, the effect of calcium and potassium application as additive in saline root media for reduce salinity adverse effects was investigated on tomato growth in a hydroponic system with unequal distribution of salts in the root media, which was divided into two equal parts containing full Johnson nutrient solution and 40 mM NaCl solution, alone or in combination with KCl (6 mM), CaCl2 (4 mM), K+Ca (3+2 mM) or half-strength Johnson nutrient solution. The root splits were exchanged every 7 days. Results showed that addition of calcium, calcium-potassium and nutrition elements equivalent to half the concentration of Johnson formula to the saline-half of culture media minimized the reduction in plant growth caused by NaCl, although the addition of potassium to culture media was not effective. The greatest concentration of sodium was observed at the shoot of treatments which had the smallest growth. According to the results of this study, in the case of dynamic and non-uniform distribution of salts in the root media, by the addition of additive to the saline solution, it would be possible to use of saline water with no significant growth reduction.Keywords: calcium, hydroponic, local salinity, potassium, salin water, tomato
Procedia PDF Downloads 443