Search results for: experiment under temperature change
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 15012

Search results for: experiment under temperature change

3222 Revisiting the Link between Corporate Social Performance and Corporate Financial Performance Post 2008 Global Economic Crisis

Authors: Anand Choudhary

Abstract:

Following the global economic crisis in 2008, businesses and more especially the big multinational conglomerates were increasingly viewed by the people world over as one of the major causes of the economic problems faced by millions globally, in terms of job loss and lifetime savings being wiped out as banks and pension funds went bankrupt and people stared at an insecure financial future. This caused a lot of resentment in the public against big businesses and fueled several protest movements by the people such as “Occupy Wall Street” in different parts of the world. This forced the big businesses to respond to the challenge by adopting more people-centric policies and initiatives for local communities in societies where they operate as part of their corporate social responsibility (CSR), in order to regain their social acceptance among the people whilst earning their ‘social license to operate’. The current paper studies many of such large MNCs across the United States of America, India and South Africa, which changed the way they did business earlier, following the global economic crisis in 2008, by incorporating capacity building initiatives for local communities as part of their CSR strategy and explores whether it has contributed to improving their financial performance. It is a conceptual research paper using secondary source data. The findings reveal that there is a positive correlation between the companies’ corporate social performance and corporate financial performance. In addition, the findings also bring to light that the MNCs examined as part of the current paper have improved their image in the eyes of their stakeholders following the change in their CSR strategy and initiatives.

Keywords: corporate social responsibility (CSR), Corporate Social Performance (CSP), Corporate Financial Performance (CFP), local communities

Procedia PDF Downloads 319
3221 Solid State Fermentation Process Development for Trichoderma asperellum Using Inert Support in a Fixed Bed Fermenter

Authors: Mauricio Cruz, Andrés Díaz García, Martha Isabel Gómez, Juan Carlos Serrato Bermúdez

Abstract:

The disadvantages of using natural substrates in SSF processes have been well recognized and mainly are associated to gradual decomposition of the substrate, formation of agglomerates and decrease of porosity bed generating limitations in the mass and heat transfer. Additionally, in several cases, materials with a high agricultural value such as sour milk, beets, rice, beans and corn have been used. Thus, the use of economic inert supports (natural or synthetic) in combination with a nutrient suspension for the production of biocontrol microorganisms is a good alternative in SSF processes, but requires further studies in the fields of modeling and optimization. Therefore, the aim of this work is to compare the performance of two inert supports, a synthetic (polyurethane foam) and a natural one (rice husk), identifying the factors that have the major effects on the productivity of T. asperellum Th204 and the maximum specific growth rate in a PROPHYTA L05® fixed bed bioreactor. For this, the six factors C:N ratio, temperature, inoculation rate, bed height, air moisture content and airflow were evaluated using a fractional design. The factors C:N and air flow were identified as significant on the productivity (expressed as conidia/dry substrate•h). The polyurethane foam showed higher maximum specific growth rate (0.1631 h-1) and productivities of 3.89 x107 conidia/dry substrate•h compared to rice husk (2.83x106) and natural substrate based on rice (8.87x106) used as control. Finally, a quadratic model was generated and validated, obtaining productivities higher than 3.0x107 conidia/dry substrate•h with air flow at 0.9 m3/h and C:N ratio at 18.1.

Keywords: bioprocess, scale up, fractional design, C:N ratio, air flow

Procedia PDF Downloads 491
3220 Ultrasonic Treatment of Baker’s Yeast Effluent

Authors: Emine Yılmaz, Serap Fındık

Abstract:

Baker’s yeast industry uses molasses as a raw material. Molasses is end product of sugar industry. Wastewater from molasses processing presents large amount of coloured substances that give dark brown color and high organic load to the effluents. The main coloured compounds are known as melanoidins. Melanoidins are product of Maillard reaction between amino acid and carbonyl groups in molasses. Dark colour prevents sunlight penetration and reduces photosynthetic activity and dissolved oxygen level of surface waters. Various methods like biological processes (aerobic and anaerobic), ozonation, wet air oxidation, coagulation/flocculation are used to treatment of baker’s yeast effluent. Before effluent is discharged adequate treatment is imperative. In addition to this, increasingly stringent environmental regulations are forcing distilleries to improve existing treatment and also to find alternative methods of effluent management or combination of treatment methods. Sonochemical oxidation is one of the alternative methods. Sonochemical oxidation employs ultrasound resulting in cavitation phenomena. In this study, decolorization of baker’s yeast effluent was investigated by using ultrasound. Baker’s yeast effluent was supplied from a factory which is located in the north of Turkey. An ultrasonic homogenizator used for this study. Its operating frequency is 20 kHz. TiO2-ZnO catalyst has been used as sonocatalyst. The effects of molar proportion of TiO2-ZnO, calcination temperature and time, catalyst amount were investigated on the decolorization of baker’s yeast effluent. The results showed that prepared composite TiO2-ZnO with 4:1 molar proportion treated at 700°C for 90 min provides better result. Initial decolorization rate at 15 min is 3% without catalyst, 14,5% with catalyst treated at 700°C for 90 min respectively.

Keywords: baker’s yeast effluent, decolorization, sonocatalyst, ultrasound

Procedia PDF Downloads 451
3219 Estimation of Carbon Uptake of Seoul City Street Trees in Seoul and Plans for Increase Carbon Uptake by Improving Species

Authors: Min Woo Park, Jin Do Chung, Kyu Yeol Kim, Byoung Uk Im, Jang Woo Kim, Hae Yeul Ryu

Abstract:

Nine representative species of trees among all the street trees were selected to estimate the absorption amount of carbon dioxide emitted from street trees in Seoul calculating the biomass, amount of carbon saved, and annual absorption amount of carbon dioxide in each of the species. Planting distance of street trees in Seoul was 1,851,180 m, the number of planting lines was 1,287, the number of planted trees was 284,498 and 46 species of trees were planted as of 2013. According to the result of plugging the quantity of species of street trees in Seoul on the absorption amount of each of the species, 120,097 ton of biomass, 60,049.8 ton of amount of carbon saved, and 11,294 t CO2/year of annual absorption amount of carbon dioxide were calculated. Street ratio mentioned on the road statistics in Seoul in 2022 is 23.13%. If the street trees are assumed to be increased in the same rate, the number of street trees in Seoul was calculated to be 294,823. The planting distance was estimated to be 1,918,360 m, and the annual absorption amount of carbon dioxide was measured to be 11,704 t CO2/year. Plans for improving the annual absorption amount of carbon dioxide from street trees were established based on the expected amount of absorption. First of all, it is to improve the annual absorption amount of carbon dioxide by increasing the number of planted street trees after adjusting the planting distance of street trees. If adjusting the current planting distance to 6 m, it was turned out that 12,692.7 t CO2/year was absorbed on an annual basis. Secondly, it is to change the species of trees to tulip trees that represent high absorption rate. If increasing the proportion of tulip trees to 30% up to 2022, the annual absorption rate of carbon dioxide was calculated to be 17804.4 t CO2/year.

Keywords: absorption of carbon dioxide, source of absorbing carbon dioxide, trees in city, improving species

Procedia PDF Downloads 343
3218 Genome Editing in Sorghum: Advancements and Future Possibilities: A Review

Authors: Micheale Yifter Weldemichael, Hailay Mehari Gebremedhn, Teklehaimanot Hailesslasie

Abstract:

The advancement of target-specific genome editing tools, including clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein9 (Cas9), mega-nucleases, base editing (BE), prime editing (PE), transcription activator-like endonucleases (TALENs), and zinc-finger nucleases (ZFNs), have paved the way for a modern era of gene editing. CRISPR/Cas9, as a versatile, simple, cost-effective and robust system for genome editing, has dominated the genome manipulation field over the last few years. The application of CRISPR/Cas9 in sorghum improvement is particularly vital in the context of ecological, environmental and agricultural challenges, as well as global climate change. In this context, gene editing using CRISPR/Cas9 can improve nutritional value, yield, resistance to pests and disease and tolerance to different abiotic stress. Moreover, CRISPR/Cas9 can potentially perform complex editing to reshape already available elite varieties and new genetic variations. However, existing research is targeted at improving even further the effectiveness of the CRISPR/Cas9 genome editing techniques to fruitfully edit endogenous sorghum genes. These findings suggest that genome editing is a feasible and successful venture in sorghum. Newer improvements and developments of CRISPR/Cas9 techniques have further qualified researchers to modify extra genes in sorghum with improved efficiency. The fruitful application and development of CRISPR techniques for genome editing in sorghum will not only help in gene discovery, creating new, improved traits in sorghum regulating gene expression sorghum functional genomics, but also in making site-specific integration events.

Keywords: CRISPR/Cas9, genome editing, quality, sorghum, stress, yield

Procedia PDF Downloads 43
3217 Determining the Sources of Sediment at Different Areas of the Catchment: A Case Study of Welbedacht Reservoir, South Africa

Authors: D. T. Chabalala, J. M. Ndambuki, M. F. Ilunga

Abstract:

Sedimentation includes the processes of erosion, transportation, deposition, and the compaction of sediment. Sedimentation in reservoir results in a decrease in water storage capacity, downstream problems involving aggregation and degradation, blockage of the intake, and change in water quality. A study was conducted in Caledon River catchment in the upstream of Welbedacht Reservoir located in the South Eastern part of Free State province, South Africa. The aim of this research was to investigate and develop a model for an Integrated Catchment Modelling of Sedimentation processes and management for the Welbedacht reservoir. Revised Universal Soil Loss Equation (RUSLE) was applied to determine sources of sediment at different areas of the catchment. The model has been also used to determine the impact of changes from management practice on erosion generation. The results revealed that the main sources of sediment in the watershed are cultivated land (273 ton per hectare), built up and forest (103.3 ton per hectare), and grassland, degraded land, mining and quarry (3.9, 9.8 and 5.3 ton per hectare) respectively. After application of soil conservation practices to developed Revised Universal Soil Loss Equation model, the results revealed that the total average annual soil loss in the catchment decreased by 76% and sediment yield from cultivated land decreased by 75%, while the built up and forest area decreased by 42% and 99% respectively. Thus, results of this study will be used by government departments in order to develop sustainable policies.

Keywords: Welbedacht reservoir, sedimentation, RUSLE, Caledon River

Procedia PDF Downloads 180
3216 Antioxidative Maillard Reaction Products Derived from Gelatin Hydrolysate of Unicorn Leatherjacket Skin

Authors: Supatra Karnjanapratum, Soottawat Benjakul

Abstract:

Gelatin hydrolysate, especially from marine resource, has been known to possess antioxidative activity. Nevertheless, the activity is still lower in comparison with the commercially available antioxidant. Maillard reactions can be use to increase antioxidative activity of gelatin hydrolysate, in which the numerous amino group could be involved in glycation. In the present study, gelatin hydrolysate (GH) from unicorn leatherjacket skin prepared using glycyl endopeptidase with prior autolysis assisted process was used for preparation of Maillard reaction products (MRPs) under dry condition. The impacts of different factors including, types of saccharides, GH to saccharide ratio, incubation temperatures, relative humidity (RH) and times on antioxidative activity of MRPs were investigated. MRPs prepared using the mixture of GH and galactose showed the highest antioxidative activity as determined by both ABTS radical scavenging activity and ferric reducing antioxidant power during heating (0-48 h) at 60 °C with 65% RH, compared with those derived from other saccharide tested. GH to galactose ratio at 2:1 (w/w) yielded the MRPs with the highest antioxidative activity, followed by the ratios of 1:1 and 1:2, respectively. When the effects of incubation temperatures (50, 60, 70 °C) and RH (55, 65, 75%) were examined, the highest browning index and the absorbance at 280 nm were found at 70 °C, regardless of RH. The pH and free amino group content of MRPs were decreased with the concomitant increase in antioxidative activity as the reaction time increased. Antioxidative activity of MRPs generally increased with increasing temperature and the highest antioxidative activity was found when RH of 55% was used. Based on electrophoresis of MRP, the polymerization along with the formation of high molecular weight material was observed. The optimal condition for preparing antioxidative MRPs was heating the mixture of GH and galactose (2:1) at 70 °C and 55% RH for 36 h. Therefore, antioxidative activity of GH was improved by Maillard reaction and the resulting MRP could be used as natural antioxidant in food products.

Keywords: antioxidative activity, gelatin hydrolysate, maillard reaction, unicorn leatherjacket

Procedia PDF Downloads 239
3215 Analyzing Emerging Scientific Domains in Biomedical Discourse: Case Study Comparing Microbiome, Metabolome, and Metagenome Research in Scientific Articles

Authors: Kenneth D. Aiello, M. Simeone, Manfred Laubichler

Abstract:

It is increasingly difficult to analyze emerging scientific fields as contemporary scientific fields are more dynamic, their boundaries are more porous, and the relational possibilities have increased due to Big Data and new information sources. In biomedicine, where funding, medical categories, and medical jurisdiction are determined by distinct boundaries on biomedical research fields and definitions of concepts, ambiguity persists between the microbiome, metabolome, and metagenome research fields. This ambiguity continues despite efforts by institutions and organizations to establish parameters on the core concepts and research discourses. Further, the explosive growth of microbiome, metabolome, and metagenomic research has led to unknown variation and covariation making application of findings across subfields or coming to a consensus difficult. This study explores the evolution and variation of knowledge within the microbiome, metabolome, and metagenome research fields related to ambiguous scholarly language and commensurable theoretical frameworks via a semantic analysis of key concepts and narratives. A computational historical framework of cultural evolution and large-scale publication data highlight the boundaries and overlaps between the competing scientific discourses surrounding the three research areas. The results of this study highlight how discourse and language distribute power within scholarly and scientific networks, specifically the power to set and define norms, central questions, methods, and knowledge.

Keywords: biomedicine, conceptual change, history of science, philosophy of science, science of science, sociolinguistics, sociology of knowledge

Procedia PDF Downloads 107
3214 In vivo Antidiarrheal and ex-vivo Spasmolytic Activities of the Aqueous Extract of the Roots of Echinops kebericho Mesfin in Rodents and Isolated Guinea-Pig Ileum

Authors: Fisseha Shiferie (Bpharm, Mpharm)

Abstract:

Diarrhea is a common gastrointestinal disorder characterized by an increase in stool frequency and a change in stool consistency. Inspite of the availability of many drugs as antidiarrheal agents, the search for a drug with affordable cost and better efficacy is essential to overcome diarrheal problems. The root extract of Echinops kebericho, is used by traditional practitioners for the treatment of diarrhea. However, the scientific basis for this usage has not been yet established. The purpose of the present study was to evaluate the antidiarrheal and spasmolytic activities of the aqueous extract of the roots of E. kebericho in rodents and isolated guinea-pig ileum preparations. In the castor oil induced intestinal transit test, E. kebericho produced a significant (p < 0.01) dose dependent decrease in propulsion with peristaltic index values of 45.05±3.3, 42.71±2.25 and 33.17±3.3%, respectively at doses of 100, 200 and 400 mg/kg compared with 63.43±7.3% for control. In the castor oil-induced diarrhea test, the mean defecation was reduced from 1.81±0.18 to 0.99 ± 0.21 compared with 2.59 ±0.81 for control. The extract (at doses stated above) significantly decreased the volume of intestinal fluid secretion induced by castor oil (2.31±0.1 to 2.01±0.2) in relation to 3.28±0.3 for control. When tested on a guinea-pig ileum, root extract of Echinops kebericho exhibited a dose dependent spasmolytic effect, 23.07 % being its highest inhibitory effect. The results obtained in this study give some scientific support to the use of Echinops kebericho as an antidiarrheal agent due to its inhibitory effects on the different diarrheal parameters used in this study.

Keywords: antidiarrheal activity, E. kebericho, traditional medicine, diarrhea, enteropooling, and intestinal transit

Procedia PDF Downloads 299
3213 Development of Multifunctional Yarns and Fabrics for Interactive Textiles

Authors: Muhammad Bilal Qadir, Danish Umer, Amir Shahzad

Abstract:

The use of conductive materials in smart and interactive textiles is gaining significant importance for creating value addition, innovation, and functional product development. These products find their potential applications in health monitoring, military, protection, communication, sensing, monitoring, actuation, fashion, and lifestyles. The materials which are most commonly employed in such type of interactive textile include intrinsically conducting polymers, conductive inks, and metallic coating on textile fabrics and inherently conducting metallic fibre yarns. In this study, silver coated polyester filament yarn is explored for the development of multifunctional interactive gloves. The composite yarn was developed by covering the silver coated polyester filament around the polyester spun yarn using hollow spindle technique. The electrical and tensile properties of the yarn were studied. This novel yarn was used to manufacture a smart glove to explore the antibacterial, functional, and interactive properties of the yarn. The change in electrical resistance due to finger movement at different bending positions and antimicrobial properties were studied. This glove was also found useful as an interactive tool to operate the commonly used touch screen devices due to its conductive nature. The yarn can also be used to develop the sensing elements like stretch, strain, and piezoresistive sensors. Such sensor can be effectively used in medical and sports textile for performance monitoring, vital signs monitoring and development of antibacterial textile for healthcare and hygiene.

Keywords: conductive yarn, interactive textiles, piezoresistive sensors, smart gloves

Procedia PDF Downloads 226
3212 Response Surface Methodology Approach to Defining Ultrafiltration of Steepwater from Corn Starch Industry

Authors: Zita I. Šereš, Ljubica P. Dokić, Dragana M. Šoronja Simović, Cecilia Hodur, Zsuzsanna Laszlo, Ivana Nikolić, Nikola Maravić

Abstract:

In this work the concentration of steep-water from corn starch industry is monitored using ultrafiltration membrane. The aim was to examine the conditions of ultrafiltration of steep-water by applying the membrane of 2.5nm. The parameters that vary during the course of ultrafiltration, were the transmembrane pressure, flow rate, while the permeate flux and the dry matter content of permeate and retentive were the dependent parameter constantly monitored during the process. Experiments of ultrafiltration are conducted on the samples of steep-water, which were obtained from the starch wet milling plant Jabuka, Pancevo. The procedure of ultrafiltration on a single-channel 250mm length, with inner diameter of 6.8mm and outer diameter of 10mm membrane were carried on. The membrane is made of a-Al2O3 with TiO2 layer obtained from GEA (Germany). The experiments are carried out at a flow rate ranging from 100 to 200lh-1 and transmembrane pressure of 1-3 bars. During the experiments of steep-water ultrafiltration, the change of permeate flux, dry matter content of permeate and retentive, as well as the absorbance changes of the permeate and retentive were monitored. The experimental results showed that the maximum flux reaches about 40lm-2h-1. For responses obtained after experiments, a polynomial model of the second degree is established to evaluate and quantify the influence of the variables. The quadratic equitation fits with the experimental values, where the coefficient of determination for flux is 0.96. The dry matter content of the retentive is increased for about 6%, while the dry matter content of permeate was reduced for about 35-40%, respectively. During steep-water ultrafiltration in permeate stays 40% less dry matter compared to the feed.

Keywords: ultrafiltration, steep-water, starch industry, ceramic membrane

Procedia PDF Downloads 268
3211 Agricultural Land Suitability Analysis of Kampe-Omi Irrigation Scheme Using Remote Sensing and Geographic Information System

Authors: Olalekan Sunday Alabi, Titus Adeyemi Alonge, Olumuyiwa Idowu Ojo

Abstract:

Agricultural land suitability analysis and mapping play an imperative role for sustainable utilization of scarce physical land resources. The objective of this study was to prepare spatial database of physical land resources for irrigated agriculture and to assess land suitability for irrigation and developing suitable area map of the study area. The study was conducted at Kampe-Omi irrigation scheme located at Yagba West Local Government Area of Kogi State, Nigeria. Temperature and rainfall data of the study area were collected for 10 consecutive years (2005-2014). Geographic Information System (GIS) techniques were used to develop irrigation land suitability map of the study area. Attribute parameters such as the slope, soil properties, topography of the study area were used for the analysis. The available data were arranged, proximity analysis of Arc-GIS was made, and this resulted into five mapping units. The final agricultural land suitability map of the study area was derived after overlay analysis. Based on soil composition, slope, soil properties and topography, it was concluded that; Kampe-Omi has rich sandy loam soil, which is viable for agricultural purpose, the soil composition is made up of 60% sand and 40% loam. The land-use pattern map of Kampe-Omi has vegetal area and water-bodies covering 55.6% and 19.3% of the total assessed area respectively. The landform of Kampe-Omi is made up of 41.2% lowlands, 37.5% normal lands and 21.3% highlands. Kampe-Omi is adequately suitable for agricultural purpose while an extra of 20.2% of the area is highly suitable for agricultural purpose making 72.6% while 18.7% of the area is slightly suitable.

Keywords: remote sensing, GIS, Kampe–Omi, land suitability, mapping

Procedia PDF Downloads 180
3210 A Methodology for the Identification of Technological Gaps and the Measurement of the Level of Technological Acceptance in the Rural Sector in Colombia

Authors: Anyi Katherine Garzon Robles, Luis Carlos Gomez Florez

Abstract:

Since the advent of the Internet, the use of Information Technologies (IT) has increased exponentially. The field of informatics and telecommunications has put on the table countless possibilities for the development of different socio-economic activities, promoting a change of social paradigm and the emergence of the so-called information and knowledge society. For more than a decade, the Colombian government has been working on the incorporation of IT into the public sector through an e-government strategy. However, to date, many technological gaps has not yet been identified in the country to our knowledge, especially in rural areas and far from large cities, where factors such as low investment and the expansion of the armed conflict have led to economic and technological stagnation. This paper presents the research results obtained from the execution of a research project, which was approach from a qualitative approach and a methodological design of a participatory action research type. This design consists of nine fundamental stages divided into four work cycles. For which different strategies for data collection and analysis were established. From which, a methodology was obtained for the identification of technological gaps and the measurement of the level of technological acceptance in the rural sector, based on the TAM (Technology Acceptance Model) model, as a previous activity to the development of IT solutions framed in the e-government strategy in Colombia. The result of this research work represents a contribution from academia for the improvement of the country's technological development and a guide for the proper planning of IT solutions aimed at promoting a close relationship between government and citizens.

Keywords: E-government, knowledge society, level of technological acceptance, technological gaps, technology acceptance model

Procedia PDF Downloads 221
3209 Young Social Beings: An Investigation into the Social Interactions and Relationships of a Year Five Class

Authors: A. Sewell

Abstract:

The paper reports a research project which investigated the social interactions of nine to ten-year-olds in a mainstream primary school. The project implemented an adaption of a whole class, behavioural intervention known as 'The Good Behaviour Game (TGBG)'. TGBG is an evidence-based intervention traditionally used to reduce low-level disruptive behaviours in a classroom setting. TGBG was adapted to encourage pupil’s engagement in pro-social behaviour during lessons. A mixed methods research design was employed to evaluate intervention effects and pupil’s perceptions of their social interactions and relationships with others. Single-case research design was used to evaluate behaviour change, and Personal Construct Psychology (PCP) repertory grids were used to explore pupil’s perceptions. The findings demonstrated that TGBG could be successfully adapted to positively influence pupil’s engagement in pro-social behaviours. The findings from the PCP repertory grid interviews revealed the complexities of how children construct their social interactions and relationships with others, and how an understanding of these could be used to design better social skills interventions. It is concluded that TGBG is a cost-effective, simple to implement intervention for promoting positive social interactions and relationships at the whole class level. The paper presents the aims, design, findings, and conclusions of the study in further detail and relates limitations and potential future extensions of the research. The outcomes have direct application and relevance for practitioners interested in children’s social development and how to promote positive outcomes in this critical aspect of childhood.

Keywords: social skills, social development, social competency, the good behaviour game

Procedia PDF Downloads 152
3208 Safety Testing of Commercial Lithium-Ion Batteries and Failure Modes Analysis

Authors: Romeo Malik, Yashraj Tripathy, Anup Barai

Abstract:

Transportation safety is a major concern for vehicle electrification on a large-scale. The failure cost of lithium-ion batteries is substantial and is significantly impacted by higher liability and replacement cost. With continuous advancement on the material front in terms of higher energy density, upgrading safety characteristics are becoming more crucial for broader integration of lithium-ion batteries. Understanding and impeding thermal runaway is the prime issue for battery safety researchers. In this study, a comprehensive comparison of thermal runaway mechanisms for two different cathode types, Li(Ni₀.₃Co₀.₃Mn₀.₃)O₂ and Li(Ni₀.₈Co₀.₁₅Al₀.₀₅)O₂ is explored. Both the chemistries were studied for different states of charge, and the various abuse scenarios that lead to thermal runaway is investigated. Abuse tests include mechanical abuse, electrical abuse, and thermal abuse. Batteries undergo thermal runaway due to a series of combustible reactions taking place internally; this is observed as multiple jets of flame reaching temperatures of the order of 1000ºC. The physicochemical characterisation was performed on cells, prior to and after abuse. Battery’s state of charge and chemistry have a significant effect on the flame temperature profiles which is otherwise quantified as heat released. Majority of the failures during transportation is due to these external short circuit. Finally, a mitigation approach is proposed to impede the thermal runaway hazard. Transporting lithium-ion batteries under low states of charge is proposed as a way forward. Batteries at low states of charge have demonstrated minimal heat release under thermal runaway reducing the risk of secondary hazards such as thermal runaway propagation.

Keywords: battery reliability, lithium-ion batteries, thermal runaway characterisation, tomography

Procedia PDF Downloads 99
3207 Simulation and Fabrication of Plasmonic Lens for Bacteria Detection

Authors: Sangwoo Oh, Jaewoo Kim, Dongmin Seo, Jaewon Park, Yongha Hwang, Sungkyu Seo

Abstract:

Plasmonics has been regarded one of the most powerful bio-sensing modalities to evaluate bio-molecular interactions in real-time. However, most of the plasmonic sensing methods are based on labeling metallic nanoparticles, e.g. gold or silver, as optical modulation markers, which are non-recyclable and expensive. This plasmonic modulation can be usually achieved through various nano structures, e.g., nano-hole arrays. Among those structures, plasmonic lens has been regarded as a unique plasmonic structure due to its light focusing characteristics. In this study, we introduce a custom designed plasmonic lens array for bio-sensing, which was simulated by finite-difference-time-domain (FDTD) approach and fabricated by top-down approach. In our work, we performed the FDTD simulations of various plasmonic lens designs for bacteria sensor, i.e., Samonella and Hominis. We optimized the design parameters, i.e., radius, shape, and material, of the plasmonic lens. The simulation results showed the change in the peak intensity value with the introduction of each bacteria and antigen i.e., peak intensity 1.8711 a.u. with the introduction of antibody layer of thickness of 15nm. For Salmonella, the peak intensity changed from 1.8711 a.u. to 2.3654 a.u. and for Hominis, the peak intensity changed from 1.8711 a.u. to 3.2355 a.u. This significant shift in the intensity due to the interaction between bacteria and antigen showed a promising sensing capability of the plasmonic lens. With the batch processing and bulk production of this nano scale design, the cost of biological sensing can be significantly reduced, holding great promise in the fields of clinical diagnostics and bio-defense.

Keywords: plasmonic lens, FDTD, fabrication, bacteria sensor, salmonella, hominis

Procedia PDF Downloads 254
3206 Language Development and Learning about Violence

Authors: Karen V. Lee

Abstract:

The background and significance of this study involves research about a music teacher discovering how language development and learning can help her overcome harmful and lasting consequences from sexual violence. Education about intervention resources from language development that helps her cope with consequences influencing her career as teacher. Basic methodology involves the qualitative method of research as theoretical framework where the author is drawn into a deep storied reflection about political issues surrounding teachers who need to overcome social, psychological, and health risk behaviors from violence. Sub-themes involve available education from learning resources to ensure teachers receive social, emotional, physical, spiritual, and intervention resources that evoke visceral, emotional responses from the audience. Major findings share how language development and learning provide helpful resources to victims of violence. It is hoped the research dramatizes an episodic yet incomplete story that highlights the circumstances surrounding the protagonist’s life. In conclusion, the research has a reflexive storied framework that embraces harmful and lasting consequences from sexual violence. The reflexive story of the sensory experience critically seeks verisimilitude by evoking lifelike and believable feelings from others. Thus, the scholarly importance of using language development and learning for intervention resources can provide transformative aspects that contribute to social change. Overall, the circumstance surrounding the story about sexual violence is not uncommon in society. Language development and learning supports the moral mission to help teachers overcome sexual violence that socially impacts their professional lives as victims.

Keywords: intervention, language development and learning, sexual violence, story

Procedia PDF Downloads 321
3205 Powder Assisted Sheet Forming to Fabricate Ti Capsule Magnetic Hyperthermia Implant

Authors: Keigo Nishitani, Kohei Mizuta Mizuta, Kazuyoshi Kurita, Yukinori Taniguchi

Abstract:

To establish mass production process of Ti capsule which has Fe powder inside as magnetic hyperthermia implant, we assumed that Ti thin sheet can be drawn into a φ1.0 mm die hole through the medium of Fe Powder and becomes outer shell of capsule. This study discusses mechanism of powder assisted deep drawing process by both of numerical simulation and experiment. Ti thin sheet blank was placed on die, and was covered by Fe powder layer without pressurizing. Then upper punch was indented on the Fe powder layer, and the blank can be drawn into die cavity as pressurized powder particles were extruded into die cavity from behind of the drawn blank. Distinct Element Method (DEM) has been used to demonstrate the process. To identify bonding parameters on Fe particles which are cohesion, tensile bond stress and inter particle friction angle, axial and diametrical compression failure test of Fe powder compact was conducted. Several density ratios of powder compacts in range of 0.70 - 0.85 were investigated and relationship between mean stress and equivalent stress was calculated with consideration of critical state line which rules failure criterion in consolidation of Fe powder. Since variation of bonding parameters with density ratio has been experimentally identified, and good agreement has been recognized between several failure tests and its simulation, demonstration of powder assisted sheet forming by using DEM becomes applicable. Results of simulation indicated that indent/drawing length of Ti thin sheet is promoted by smaller Fe particle size, larger indent punch diameter, lower friction coefficient between die surface and Ti sheet and certain degrees of die inlet taper angle. In the deep drawing test, we have made die-set with φ2.4 mm punch and φ1.0 mm die bore diameter. Pure Ti sheet with 100 μm thickness, annealed at 650 deg. C has been tested. After indentation, indented/drawn capsule has been observed by microscope, and its length was measured to discuss the feasibility of this capsulation process. Longer drawing length exists on progressive loading pass comparing with the case of single stroke loading. It is expected that progressive loading has an advantage of which extrusion of powder particle into die cavity with Ti sheet is promoted since powder particle layer can be rebuilt while the punch is withdrawn from the layer in each loading steps. This capsulation phenomenon is qualitatively demonstrated by DEM simulation. Finally, we have fabricated Ti capsule which has Fe powder inside for magnetic hyperthermia cancer care treatment. It is concluded that suggested method is possible to use the manufacturing of Ti capsule implant for magnetic hyperthermia cancer care.

Keywords: metal powder compaction, metal forming, distinct element method, cancer care, magnetic hyperthermia

Procedia PDF Downloads 272
3204 A Two-Phase Flow Interface Tracking Algorithm Using a Fully Coupled Pressure-Based Finite Volume Method

Authors: Shidvash Vakilipour, Scott Ormiston, Masoud Mohammadi, Rouzbeh Riazi, Kimia Amiri, Sahar Barati

Abstract:

Two-phase and multi-phase flows are common flow types in fluid mechanics engineering. Among the basic and applied problems of these flow types, two-phase parallel flow is the one that two immiscible fluids flow in the vicinity of each other. In this type of flow, fluid properties (e.g. density, viscosity, and temperature) are different at the two sides of the interface of the two fluids. The most challenging part of the numerical simulation of two-phase flow is to determine the location of interface accurately. In the present work, a coupled interface tracking algorithm is developed based on Arbitrary Lagrangian-Eulerian (ALE) approach using a cell-centered, pressure-based, coupled solver. To validate this algorithm, an analytical solution for fully developed two-phase flow in presence of gravity is derived, and then, the results of the numerical simulation of this flow are compared with analytical solution at various flow conditions. The results of the simulations show good accuracy of the algorithm despite using a nearly coarse and uniform grid. Temporal variations of interface profile toward the steady-state solution show that a greater difference between fluids properties (especially dynamic viscosity) will result in larger traveling waves. Gravity effect studies also show that favorable gravity will result in a reduction of heavier fluid thickness and adverse gravity leads to increasing it with respect to the zero gravity condition. However, the magnitude of variation in favorable gravity is much more than adverse gravity.

Keywords: coupled solver, gravitational force, interface tracking, Reynolds number to Froude number, two-phase flow

Procedia PDF Downloads 296
3203 Functional Role of Tyr12 in the Catalytic Activity of Zeta-Like Glutathione S-Transferase from Acidovorax sp. KKS102

Authors: D. Shehu, Z. Alias

Abstract:

Glutathione S-transferases (GSTs) are family of enzymes that function in the detoxification of variety of electrophilic substrates. In the present work, we report a novel zeta-like GST (designated as KKSG9) from the biphenyl/polychlorobiphenyl degrading organism Acidovorax sp. KKS102. KKSG9 possessed low sequence similarity but similar biochemical properties to zeta class GSTs. The gene for KKSG9 was cloned, purified and biochemically characterized. Functional analysis showed that the enzyme exhibits wider substrate specificity compared to most zeta class GSTs by reacting with 1-chloro-2,4-dinitrobenzene (CDNB), p-nitrobenzyl chloride (NBC), ethacrynic acid (EA), hydrogen peroxide, and cumene hydroperoxide (CuOOH). The enzyme also displayed dehalogenation function against dichloroacetate (a common substrate for zeta class GSTs) in addition to permethrin, and dieldrin. The functional role of Tyr12 was also investigated by site-directed mutagenesis. The mutant (Y12C) displayed low catalytic activity and dehalogenation function against all the substrates when compared with the wild type. Kinetic analysis using NBC and GSH as substrates showed that the mutant (Y12C) displayed a higher affinity for NBC when compared with the wild type, however, no significant change in GSH affinity was observed. These findings suggest that the presence of tyrosine residue in the motif might represent an evolutionary trend toward improving the catalytic activity of the enzyme. The enzyme as well could be useful in the bioremediation of various types of organochlorine pollutants.

Keywords: Acidovorax sp. KKS102, bioremediation, glutathione s-transferase, site-directed mutagenesis, zeta

Procedia PDF Downloads 138
3202 Multi-Index Performance Investigation of Rubberized Reclaimed Asphalt Mixture

Authors: Ling Xu, Giuseppe Loprencipe, Antonio D'Andrea

Abstract:

Asphalt pavement with recycled and sustainable materials has become the most commonly adopted strategy for road construction, including reclaimed asphalt pavement (RAP) and crumb rubber (CR) from waste tires. However, the adhesion and cohesion characteristics of rubberized reclaimed asphalt pavement were still ambiguous, resulting in deteriorated adhesion behavior and life performance. This research investigated the effect of bonding characteristics on rutting resistance and moisture susceptibility of rubberized reclaimed asphalt pavement in terms of two RAP sources with different oxidation levels and two tire rubber with different particle sizes. Firstly, the binder bond strength (BBS) test and bonding failure distinguishment were conducted to analyze the surface behaviors of binder-aggregate interaction. Then, the compatibility and penetration grade of rubberized RAP binder were evaluated by rotational viscosity test and penetration test, respectively. Hamburg wheel track (HWT) test with high-temperature viscoelastic deformation analysis was adopted, which illustrated the rutting resistance. Additionally, a water boiling test was employed to evaluate the moisture susceptibility of the mixture and the texture features were characterized with the statistical parameters of image colors. Finally, the colloid structure model of rubberized RAP binder with surface interaction was proposed, and statistical analysis was established to release the correlation among various indexes. This study concluded that the gel-phase colloid structure and molecular diffusion of the free light fraction would affect the surface interpretation with aggregate, determining the bonding characteristic of rubberized RAP asphalt.

Keywords: bonding characteristics, reclaimed asphalt pavement, rubberized asphalt, sustainable material

Procedia PDF Downloads 44
3201 Assessment of Physical and Mechanical Properties of Perlite Mortars with Recycled Cement

Authors: Saca Nastasia, Radu Lidia, Dobre Daniela, Calotă Razvan

Abstract:

In order to achieve the European Union's sustainable and circular economy goals, strategies for reducing raw material consumption, reusing waste, and lowering CO₂ emissions have been developed. In this study, expanded perlite mortars with recycled cement (RC) were obtained and characterized. The recycled cement was obtained from demolition concrete waste. The concrete waste was crushed in a jaw and grinded in a horizontal ball mill to reduce the material's average grain size. Finally, the fine particles were sieved through a 125 µm sieve. The recycled cement was prepared by heating demolition concrete waste at 550°C for 3 hours. At this temperature, the decarbonization does not occur. The utilization of recycled cement can minimize the negative environmental effects of demolished concrete landfills as well as the demand for natural resources used in cement manufacturing. Commercial cement CEM II/A-LL 42.5R was substituted by 10%, 20%, and 30% recycled cement. By substituting reference cement (CEM II/A-LL 42.5R) by RC, a decrease in cement aqueous suspension pH, electrical conductivity, and Ca²⁺ concentration was observed for all measurements (2 hours, 6 hours, 24 hours, 4 days, and 7 days). After 2 hours, pH value was 12.42 for reference and conductivity of 2220 µS/cm and decreased to 12.27, respectively 1570 µS/cm for 30% RC. The concentration of Ca²⁺ estimated by complexometric titration was 20% lower in suspension with 30% RC in comparison to reference for 2 hours. The difference significantly diminishes over time. The mortars have cement: expanded perlite volume ratio of 1:3 and consistency between 140 mm and 200 mm. The density of fresh mortar was about 1400 kg/m3. The density, flexural and compressive strengths, water absorption, and thermal conductivity of hardened mortars were tested. Due to its properties, expanded perlite mortar is a good thermal insulation material.

Keywords: concrete waste, expanded perlite, mortar, recycled cement, thermal conductivity, mechanical strength

Procedia PDF Downloads 70
3200 Performance Evaluation of Solid Lubricant Characteristics at Different Sliding Conditions

Authors: Suresh Kumar Reddy Narala, Rakesh Kumar Gunda

Abstract:

In modern industry, mechanical parts are subjected to friction and wear, leading to heat generation, which affects the reliability, life and power consumption of machinery. To overcome the tribological losses due to friction and wear, a significant portion of lubricant with high viscous properties allows very smooth relative motion between two sliding surfaces. Advancement in modern tribology has facilitated the use of applying solid lubricants in various industrial applications. Solid lubricant additives with high viscous thin film formation between the sliding surfaces can adequately wet and adhere to a work surface. In the present investigation, an attempt has been made to investigate and evaluate the tribological studies of various solid lubricants like MoS¬2, graphite, and boric acid at different sliding conditions. The base oil used in this study was SAE 40 oil with a viscosity of 220 cSt at 400C. The tribological properties were measured on pin-on-disc tribometer. An experimental set-up has been developed for effective supply of solid lubricants to the pin-disc interface zone. The results obtained from the experiments show that the friction coefficient increases with increase in applied load for all the considered environments. The tribological properties with MoS2 solid lubricant exhibit larger load carrying capacity than that of graphite and boric acid. The present research work also contributes to the understanding of the behavior of film thickness distribution of solid lubricant using potential contact technique under different sliding conditions. The results presented in this research work are expected to form a scientific basis for selecting the best solid lubricant in various industrial applications for possible minimization of friction and wear.

Keywords: friction, wear, temperature, solid lubricant

Procedia PDF Downloads 327
3199 Improving the Feeding Value of Straws with Pleurotus Ostreatus

Authors: S. Hussain, N. Ahmad, S. Alam, M. Bezabhi, W. H. Hendriks, P. Yu, J. W. Cone

Abstract:

The high content of lignin in cell walls is the major limiting factor in the digestion and utilisation of cereal crop residues by ruminants. The aim of this study was to evaluate the effectiveness of the white rot fungus, Pleurotus ostreatus (P. ostreatus), to degrade lignin and to enhance the rumen degradability of maize stover, rice straw, wheat straw and their mixture in equal proportion on a dry-matter (DM) basis. Four samples of each substrate were incubated aerobically in triplicate with P. ostreatus for 0 (Control), 21, 28 and 35 days under solid-state conditions (temperature, 24 ͦ C; humidity, 70± 5%). The changes in chemical composition, DM and nutrient losses, and rumen fermentation characteristics using in vitro DM digestibility (DMD) and the in vitro gas production (GP) technique were measured. The results showed that incubation with P. ostreatus decreased (P < 0.001) the contents of neutral detergent fibre and lignin with a concomitant increase (P < 0.001) in the contents of ash and crude protein. The losses of nutrients differed (P < 0.001) among the straw types, with rice straw and maize stover showing the largest (P < 0.05) lignin degradation compared to wheat and mixed straws. The DMD and 72-h cumulative GP increased (P < 0.001) consistently with increasing fungal incubation period and for all substrates the highest values of DMD and GP were measured after 35 days of incubation with P. ostreatus. The lignin degradation was strongly associated with hemicellulose degradation (r = 0.71) across the various straws. Results of the present study demonstrated that incubation of low-quality crop residues with P. ostreatus under solid-state conditions upgrades their feeding value by reducing the content of lignin and increasing the content of crude protein and ruminal degradation.

Keywords: crop residues, lignin degradation, maize stovers, wheat straws, white rot fungi

Procedia PDF Downloads 42
3198 Evaluation of Two Functional Food Products: Tortillas and Yogurt Based on Spirulina platensis and Haematococcus pluvialis

Authors: Raul Alexis Sanchez Cornejo, Elena Ivonne Mancera Andrade, Gibran Sidney Aleman Nava, Angel Josue Arteaga Garces, Roberto Parra Saldivar

Abstract:

An unhealthy diet is one of the main factors for a wide range of chronical diseases such as diabetes, obesity, cancer, cardiovascular diseases, among others. Nowadays, there is a current need to provide innovate healthy products to people in order to decrease the number of people with unhealthy diet. This study focuses on the production of two food products based on two microalgae strains: Tortillas with powder of Haematococcus pluvialis and Spirulina platensis biomass and yogurt with microencapsulated biomass of the same strains. S. platensis has been used widely as food supplements in a form of powder and pills due to its high content in proteins and fatty acids. Haematococcus pluvialis has been recognized for its ability to produce high-added value products under stressful conditions such as antioxidants (astaxanthin). Despite the benefits that those microalgae have, few efforts have been done to use them in food products. The main objective of this work is to evaluate the nutritional properties such as protein content, lipid fraction, carbohydrates, antioxidants,, and vitamins, that these microalgae strains provide to the food product. Additionally, physicochemical, and sensory evaluation were assessed to evaluate the quality of the product. The results obtained will dictate the feasibility of the product to be commercialized. These novel products will have the ability to change the nutritional intake and strength the health of the consumers.

Keywords: functional food, Haematococcus pluvialis, microalgae, Spirulina platensis, tortilla, yogurt

Procedia PDF Downloads 296
3197 Synthesis and Characterization of CNPs Coated Carbon Nanorods for Cd2+ Ion Adsorption from Industrial Waste Water and Reusable for Latent Fingerprint Detection

Authors: Bienvenu Gael Fouda Mbanga

Abstract:

This study reports a new approach of preparation of carbon nanoparticles coated cerium oxide nanorods (CNPs/CeONRs) nanocomposite and reusing the spent adsorbent of Cd2+- CNPs/CeONRs nanocomposite for latent fingerprint detection (LFP) after removing Cd2+ ions from aqueous solution. CNPs/CeONRs nanocomposite was prepared by using CNPs and CeONRs with adsorption processes. The prepared nanocomposite was then characterized by using UV-visible spectroscopy (UV-visible), Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction pattern (XRD), scanning electron microscope (SEM), Transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDS), Zeta potential, X-ray photoelectron spectroscopy (XPS). The average size of the CNPs was 7.84nm. The synthesized CNPs/CeONRs nanocomposite has proven to be a good adsorbent for Cd2+ removal from water with optimum pH 8, dosage 0. 5 g / L. The results were best described by the Langmuir model, which indicated a linear fit (R2 = 0.8539-0.9969). The adsorption capacity of CNPs/CeONRs nanocomposite showed the best removal of Cd2+ ions with qm = (32.28-59.92 mg/g), when compared to previous reports. This adsorption followed pseudo-second order kinetics and intra particle diffusion processes. ∆G and ∆H values indicated spontaneity at high temperature (40oC) and the endothermic nature of the adsorption process. CNPs/CeONRs nanocomposite therefore showed potential as an effective adsorbent. Furthermore, the metal loaded on the adsorbent Cd2+- CNPs/CeONRs has proven to be sensitive and selective for LFP detection on various porous substrates. Hence Cd2+-CNPs/CeONRs nanocomposite can be reused as a good fingerprint labelling agent in LFP detection so as to avoid secondary environmental pollution by disposal of the spent adsorbent.

Keywords: Cd2+-CNPs/CeONRs nanocomposite, cadmium adsorption, isotherm, kinetics, thermodynamics, reusable for latent fingerprint detection

Procedia PDF Downloads 96
3196 Investigation on Reducing the Bandgap in Nanocomposite Polymers by Doping

Authors: Sharvare Palwai, Padmaja Guggilla

Abstract:

Smart materials, also called as responsive materials, undergo reversible physical or chemical changes in their properties as a consequence of small environmental variations. They can respond to a single or multiple stimuli such as stress, temperature, moist, electric or magnetic fields, light, or chemical compounds. Hence smart materials are the basis of many applications, including biosensors and transducers, particularly electroactive polymers. As the polymers exhibit good flexibility, high transparency, easy processing, and low cost, they would be promising for the sensor material. Polyvinylidene Fluoride (PVDF), being a ferroelectric polymer, exhibits piezoelectric and pyro electric properties. Pyroelectric materials convert heat directly into electricity, while piezoelectric materials convert mechanical energy into electricity. These characteristics of PVDF make it useful in biosensor devices and batteries. However, the influence of nanoparticle fillers such as Lithium Tantalate (LiTaO₃/LT), Potassium Niobate (KNbO₃/PN), and Zinc Titanate (ZnTiO₃/ZT) in polymer films will be studied comprehensively. Developing advanced and cost-effective biosensors is pivotal to foresee the fullest potential of polymer based wireless sensor networks, which will further enable new types of self-powered applications. Finally, nanocomposites films with best set of properties; the sensory elements will be designed and tested for their performance as electric generators under laboratory conditions. By characterizing the materials for their optical properties and investigate the effects of doping on the bandgap energies, the science in the next-generation biosensor technologies can be advanced.

Keywords: polyvinylidene fluoride, PVDF, lithium tantalate, potassium niobate, zinc titanate

Procedia PDF Downloads 110
3195 Hydrogen Production from Solid Waste of Sago Processing Industries in Indonesia: Effect of Chemical and Biological Pretreatment

Authors: Pratikno Hidayat, Khamdan Cahyari

Abstract:

Hydrogen is the ultimate choice of energy carriers in future. It contents high energy density (42 kJ/g), emits only water vapor during combustion and has high energy conversion up to 50% in fuel cell application. One of the promising methods to produce hydrogen is from organic waste through dark fermentation method. It utilizes sugar-rich organic waste as substrate and hydrogen-producing microorganisms to generate the hydrogen. Solid waste of sago processing industries in Indonesia is one of the promising raw materials for both producing biofuel hydrogen and mitigating the environmental impact due to the waste disposal. This research was meant to investigate the effect of chemical and biological pretreatment i.e. acid treatment and mushroom cultivation toward lignocellulosic waste of these sago industries. Chemical pretreatment was conducted through exposing the waste into acid condition using sulfuric acid (H2SO4) (various molar i.e. 0.2, 0.3, and 0.4 M and various duration of exposure i.e. 30, 60 and 90 minutes). Meanwhile, biological treatment was conducted through utilization of the solid waste as growth media of mushroom (Oyster and Ling-zhi) for 3 months. Dark fermentation was conducted at pH 5.0, temperature 27℃ and atmospheric pressure. It was noticed that chemical and biological pretreatment could improve hydrogen yield with the highest yield at 3.8 ml/g VS (31%v H2). The hydrogen production was successfully performed to generate high percentage of hydrogen, although the yield was still low. This result indicated that the explosion of acid chemical and biological method might need to be extended to improve degradability of the solid waste. However, high percentage of hydrogen was resulted from proper pretreatment of residual sludge of biogas plant to generate hydrogen-producing inoculum.

Keywords: hydrogen, sago waste, chemical, biological, dark fermentation, Indonesia

Procedia PDF Downloads 351
3194 Stabilization of Pb, Cr, Cd, Cu and Zn in Solid Waste and Sludge Pyrolysis by Modified Vermiculite

Authors: Yuxuan Yang, Zhaoping Zhong

Abstract:

Municipal solid waste and sludge are important sources of waste energy and their proper disposal is of great importance. Pyrolysis can fully decompose solid wastes and sludge, and the pyrolysis products (charcoal, oil and gas) have important recovery values. Due to the complex composition of solid wastes and sludge, the pyrolysis process at high temperatures is prone to heavy metal emissions, which are harmful to humans and the environment and reduce the safety of pyrolysis products. In this paper, heavy metal emissions during pyrolysis of municipal sewage sludge, paper mill sludge, municipal domestic waste, and aged refuse at 450-650°C were investigated and the emissions and hazards of heavy metals (Pb, Cr, Cd, Cu and Zn) were effectively reduced by adding modified vermiculite as an additive. The vermiculite was modified by intercalation with cetyltrimethylammonium bromide, which resulted in more than twice the original layer spacing of the vermiculite. Afterward, the interpolated vermiculite was made into vermiculite flakes by exfoliation modification. After that, the expansion rate of vermiculite flakes was increased by Mg2+ modification and thermal activation. The expanded vermiculite flakes were acidified to improve the textural characteristics of the vermiculite. The modified vermiculite was analysed by XRD, FT-IR, BET and SEM to clarify the modification effect. The incorporation of modified vermiculite resulted in more than 80% retention of all heavy metals at 450°C. Cr, Cu and Zn were better retained than Pb and Cd. The incorporation of modified vermiculite effectively reduced the risk of heavy metals, and all risks were low for Pb, Cr, Cu and Zn. The toxicity of all heavy metals was greatly reduced by the incorporation of modified vermiculite and the morphology of heavy metals was transformed from Exchangeable and acid-soluble (F1) and Reducible (F2) to Oxidizable (F3) and Residual (F4). In addition, the increase in temperature favored the stabilization of heavy metal forms. This study provides a new insight into the cleaner use of energy and the safe management of solid waste.

Keywords: heavy metal, pyrolysis, vermiculite, solid waste

Procedia PDF Downloads 49
3193 Influence of CA, SR and BA Substitution on lafeo3Performances During Chemical Looping Processes

Authors: Rong Sun, Laihong Shen

Abstract:

La-based perovskite oxygen carriers, especially the doped-La(M)FeO₃, showed excellent performances during chemical looping processes. However, the mechanisms of the undoped and doped La(M)FeO₃ are not clear at present, making the mechanisms clear may help the development of chemical looping technologies. In this paper, the method based on the density function theory (DFT) was used to analysis the influence of Ca, Sr, and Ba doping of La on the electronic structure, while the CO oxidation mechanisms on the surface of LaFeO₃ and Ca-doped LaFeO₃ oxygen carriers were also analyzed. The results showed that the band gap was decreased by the doping of low valence. While the doping of low valence element Ca, Sr, and Ba at La site simultaneously resulted to the moving of the valence band toward high energy and made the valence band cross the Fermi energy level. This was resulted from the holes generated by divalent ion substitution. The holes can change the total magnetization from antiferromagnet to weakly ferromagnetism. The calculation results about the formation of oxygen vacancy showed that substitutions of Ca, Sr, and Ba caused a large drop in oxygen vacancy formation energy, indicating that the bulk oxygen transport was improved. Based on the optimized bulk of the undoped and Ca-doped LaFeO₃(010) surface, the CO adsorption was analyzed. The results indicated that the adsorption energy increased by divalent ion substitution, meaning that the adsorption stability decreased. The results can provide a certain theoretical basis for the development of perovskite oxides in chemical looping technologies.

Keywords: chemical looping technologies, lanthanum ferrate (LaFeO₃), divalent ion substitution, CO oxidation

Procedia PDF Downloads 90