Search results for: recycle aggregate
190 Inulinase Immobilization on Functionalized Magnetic Nanoparticles Prepared with Soy Protein Isolate Conjugated Bovine Serum Albumin for High Fructose Syrup Production
Authors: Homa Torabizadeh, Mohaddeseh Mikani
Abstract:
Inulinase from Aspergillus niger was covalently immobilized on magnetic nanoparticles (MNPs/Fe3O4) covered with soy protein isolate (SPI/Fe3O4) functionalized by bovine serum albumin (BSA) nanoparticles. MNPs are promising enzyme carriers because they separate easily under external magnetic fields and have enhanced immobilized enzyme reusability. As MNPs aggregate simply, surface coating strategy was employed. SPI functionalized by BSA was a suitable candidate for nanomagnetite coating due to its superior biocompatibility and hydrophilicity. Fe3O4@SPI-BSA nanoparticles were synthesized as a novel carrier with narrow particle size distribution. Step by step fabrication monitoring of Fe3O4@SPI-BSA nanoparticles was performed using field emission scanning electron microscopy and dynamic light scattering. The results illustrated that nanomagnetite with the spherical morphology was well monodispersed with the diameter of about 35 nm. The average size of the SPI-BSA nanoparticles was 80 to 90 nm, and their zeta potential was around −34 mV. Finally, the mean diameter of fabricated Fe3O4@SPI-BSA NPs was less than 120 nm. Inulinase enzyme from Aspergillus niger was covalently immobilized through gluteraldehyde on Fe3O4@SPI-BSA nanoparticles successfully. Fourier transform infrared spectra and field emission scanning electron microscopy images provided sufficient proof for the enzyme immobilization on the nanoparticles with 80% enzyme loading.Keywords: high fructose syrup, inulinase immobilization, functionalized magnetic nanoparticles, soy protein isolate
Procedia PDF Downloads 299189 The Internet of Things: A Survey of Authentication Mechanisms, and Protocols, for the Shifting Paradigm of Communicating, Entities
Authors: Nazli Hardy
Abstract:
Multidisciplinary application of computer science, interactive database-driven web application, the Internet of Things (IoT) represents a digital ecosystem that has pervasive technological, social, and economic, impact on the human population. It is a long-term technology, and its development is built around the connection of everyday objects, to the Internet. It is estimated that by 2020, with billions of people connected to the Internet, the number of connected devices will exceed 50 billion, and thus IoT represents a paradigm shift in in our current interconnected ecosystem, a communication shift that will unavoidably affect people, businesses, consumers, clients, employees. By nature, in order to provide a cohesive and integrated service, connected devices need to collect, aggregate, store, mine, process personal and personalized data on individuals and corporations in a variety of contexts and environments. A significant factor in this paradigm shift is the necessity for secure and appropriate transmission, processing and storage of the data. Thus, while benefits of the applications appear to be boundless, these same opportunities are bounded by concerns such as trust, privacy, security, loss of control, and related issues. This poster and presentation look at a multi-factor authentication (MFA) mechanisms that need to change from the login-password tuple to an Identity and Access Management (IAM) model, to the more cohesive to Identity Relationship Management (IRM) standard. It also compares and contrasts messaging protocols that are appropriate for the IoT ecosystem.Keywords: Internet of Things (IoT), authentication, protocols, survey
Procedia PDF Downloads 299188 Heat Transfer Enhancement of Structural Concretes Made of Macro-Encapsulated Phase Change Materials
Authors: Ehsan Mohseni, Waiching Tang, Shanyong Wang
Abstract:
Low thermal conductivity of phase change materials (PCMs) affects the thermal performance and energy storage efficiency of latent heat thermal energy storage systems. In the current research, a structural lightweight concrete with function of indoor temperature control was developed using thermal energy storage aggregates (TESA) and nano-titanium (NT). The macro-encapsulated technique was served to incorporate the PCM into the lightweight aggregate through vacuum impregnation. The compressive strength was measured, and the thermal performance of concrete panel was evaluated by using a self-designed environmental chamber. The impact of NT on microstructure was also assessed via scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) tests. The test results indicated that NT was able to increase the compressive strength by filling the micro pores and making the microstructure denser and more homogeneous. In addition, the environmental chamber experiment showed that introduction of NT into TESA improved the heat transfer of composites noticeably. The changes were illustrated by the reduction in peak temperatures in the centre, outside and inside surfaces of concrete panels by the inclusion of NT. It can be concluded that NT particles had the capability to decrease the energy consumption and obtain higher energy storage efficiency by the reduction of indoor temperature.Keywords: heat transfer, macro-encapsulation, microstructure properties, nanoparticles, phase change material
Procedia PDF Downloads 105187 Value of Willingness to Pay for a Quality-Adjusted Life Years Gained in Iran; A Modified Chained-Approach
Authors: Seyedeh-Fariba Jahanbin, Hasan Yusefzadeh, Bahram Nabilou, Cyrus Alinia, Cyrus Alinia
Abstract:
Background: Due to the lack of a constant Willingness to Pay per one additional Quality Adjusted Life Years gained based on the preferences of Iran’s general public, the cost-efectiveness of health system interventions is unclear and making it challenging to apply economic evaluation to health resources priority setting. Methods: We have measured this cost-efectiveness threshold with the participation of 2854 individuals from fve provinces, each representing an income quintile, using a modifed Time Trade-Of-based Chained-Approach. In this online-based empirical survey, to extract the health utility value, participants were randomly assigned to one of two green (21121) and yellow (22222) health scenarios designed based on the earlier validated EQ-5D-3L questionnaire. Results: Across the two health state versions, mean values for one QALY gain (rounded) ranged from $6740-$7400 and $6480-$7120, respectively, for aggregate and trimmed models, which are equivalent to 1.35-1.18 times of the GDP per capita. Log-linear Multivariate OLS regression analysis confrmed that respondents were more likely to pay if their income, disutility, and education level were higher than their counterparts. Conclusions: In the health system of Iran, any intervention that is with the incremental cost-efectiveness ratio, equal to and less than 7402.12 USD, will be considered cost-efective.Keywords: willingness to Pay, QALY, chained-approach, cost-efectiveness threshold, Iran
Procedia PDF Downloads 85186 Desulphurization of Waste Tire Pyrolytic Oil (TPO) Using Photodegradation and Adsorption Techniques
Authors: Moshe Mello, Hilary Rutto, Tumisang Seodigeng
Abstract:
The nature of tires makes them extremely challenging to recycle due to the available chemically cross-linked polymer and, therefore, they are neither fusible nor soluble and, consequently, cannot be remolded into other shapes without serious degradation. Open dumping of tires pollutes the soil, contaminates underground water and provides ideal breeding grounds for disease carrying vermins. The thermal decomposition of tires by pyrolysis produce char, gases and oil. The composition of oils derived from waste tires has common properties to commercial diesel fuel. The problem associated with the light oil derived from pyrolysis of waste tires is that it has a high sulfur content (> 1.0 wt.%) and therefore emits harmful sulfur oxide (SOx) gases to the atmosphere when combusted in diesel engines. Desulphurization of TPO is necessary due to the increasing stringent environmental regulations worldwide. Hydrodesulphurization (HDS) is the commonly practiced technique for the removal of sulfur species in liquid hydrocarbons. However, the HDS technique fails in the presence of complex sulfur species such as Dibenzothiopene (DBT) present in TPO. This study aims to investigate the viability of photodegradation (Photocatalytic oxidative desulphurization) and adsorptive desulphurization technologies for efficient removal of complex and non-complex sulfur species in TPO. This study focuses on optimizing the cleaning (removal of impurities and asphaltenes) process by varying process parameters; temperature, stirring speed, acid/oil ratio and time. The treated TPO will then be sent for vacuum distillation to attain the desired diesel like fuel. The effect of temperature, pressure and time will be determined for vacuum distillation of both raw TPO and the acid treated oil for comparison purposes. Polycyclic sulfides present in the distilled (diesel like) light oil will be oxidized dominantly to the corresponding sulfoxides and sulfone via a photo-catalyzed system using TiO2 as a catalyst and hydrogen peroxide as an oxidizing agent and finally acetonitrile will be used as an extraction solvent. Adsorptive desulphurization will be used to adsorb traces of sulfurous compounds which remained during photocatalytic desulphurization step. This desulphurization convoy is expected to give high desulphurization efficiency with reasonable oil recovery.Keywords: adsorption, asphaltenes, photocatalytic oxidation, pyrolysis
Procedia PDF Downloads 272185 Digital Transformation and Digitalization of Public Administration
Authors: Govind Kumar
Abstract:
The concept of ‘e-governance’ that was brought about by the new wave of reforms, namely ‘LPG’ in the early 1990s, has been enabling governments across the globe to digitally transform themselves. Digital transformation is leading the governments with qualitative decisions, optimization in rational use of resources, facilitation of cost-benefit analyses, and elimination of redundancy and corruption with the help of ICT-based applications interface. ICT-based applications/technologies have enormous potential for impacting positive change in the social lives of the global citizenry. Supercomputers test and analyze millions of drug molecules for developing candidate vaccines to combat the global pandemic. Further, e-commerce portals help distribute and supply household items and medicines, while videoconferencing tools provide a visual interface between the clients and hosts. Besides, crop yields are being maximized with the help of drones and machine learning, whereas satellite data, artificial intelligence, and cloud computing help governments with the detection of illegal mining, tackling deforestation, and managing freshwater resources. Such e-applications have the potential to take governance an extra mile by achieving 5 Es (effective, efficient, easy, empower, and equity) of e-governance and six Rs (reduce, reuse, recycle, recover, redesign and remanufacture) of sustainable development. If such digital transformation gains traction within the government framework, it will replace the traditional administration with the digitalization of public administration. On the other hand, it has brought in a new set of challenges, like the digital divide, e-illiteracy, technological divide, etc., and problems like handling e-waste, technological obsolescence, cyber terrorism, e-fraud, hacking, phishing, etc. before the governments. Therefore, it would be essential to bring in a rightful mixture of technological and humanistic interventions for addressing the above issues. This is on account of the reason that technology lacks an emotional quotient, and the administration does not work like technology. Both are self-effacing unless a blend of technology and a humane face are brought in into the administration. The paper will empirically analyze the significance of the technological framework of digital transformation within the government set up for the digitalization of public administration on the basis of the synthesis of two case studies undertaken from two diverse fields of administration and present a future framework of the study.Keywords: digital transformation, electronic governance, public administration, knowledge framework
Procedia PDF Downloads 99184 Suitability Number of Coarse-Grained Soils and Relationships among Fineness Modulus, Density and Strength Parameters
Authors: Khandaker Fariha Ahmed, Md. Noman Munshi, Tarin Sultana, Md. Zoynul Abedin
Abstract:
Suitability number (SN) is perhaps one of the most important parameters of coarse-grained soil in assessing its appropriateness to use as a backfill in retaining structures, sand compaction pile, Vibro compaction, and other similar foundation and ground improvement works. Though determined in an empirical manner, it is imperative to study SN to understand its relation with other aggregate properties like fineness modulus (FM), and strength and density properties of sandy soil. The present paper reports the findings of the study on the examination of the properties of sandy soil, as mentioned. Random numbers were generated to obtain the percent fineness on various sieve sizes, and fineness modulus and suitability numbers were predicted. Sand samples were collected from the field, and test samples were prepared to determine maximum density, minimum density and shear strength parameter φ against particular fineness modulus and corresponding suitability number Five samples of SN value of excellent (0-10) and three samples of SN value fair (20-30) were taken and relevant tests were done. The data obtained from the laboratory tests were statistically analyzed. Results show that with the increase of SN, the value of FM decreases. Within the SN value rated as excellent (0-10), there is a decreasing trend of φ for a higher value of SN. It is found that SN is dependent on various combinations of grain size properties like D10, D30, and D20, D50. Strong linear relationships were obtained between SN and FM (R²=.0.93) and between SN value and φ (R²=.94). Correlation equations are proposed to define relationships among SN, φ, and FM.Keywords: density, fineness modulus, shear strength parameter, suitability number
Procedia PDF Downloads 104183 A Novel Cold Asphalt Concrete Mixture for Heavily Trafficked Binder Course
Authors: Anmar Dulaimi, Hassan Al Nageim, Felicite Ruddock, Linda Seton
Abstract:
Cold bituminous asphalt mixture (CBEM) provide a sustainable, cost effective and energy efficiency alternative to traditional hot mixtures. However, these mixtures have a comparatively low initial strength and as it is considered as evolutionary materials, mainly in the early life where the initial cohesion is low and builds up slowly. On the other hand, asphalt concrete is, by far, the most common mixtures in use as binder course and base in road pavement in the UK having a continuous grade offer a good aggregate interlock results in this material having very good load-spreading properties as well as a high resistance to permanent deformation. This study aims at developing a novel fast curing cold asphalt concrete binder course mixtures by using Ordinary Portland Cement (OPC) as a replacement to conventional mineral filler (0%-100%) while new by-product material (LJMU-A2) was used as a supplementary cementitious material. With this purpose, cold asphalt concrete binder course mixtures with cationic emulsions were studied by means of stiffness modulus whereas water sensitivity was approved by assessing the stiffness modulus ratio before and after sample conditioning. The results indicate that a substantial enhancement in the stiffness modulus and a considerable improvement of water sensitivity resistance by adding of LJMU-A2 to the cold asphalt mixtures as a supplementary cementitious material. Moreover, the addition of LJMU-A2 to those mixtures leads to stiffness modulus after 2- day curing comparable to those obtained with Portland cement after 7-day curing.Keywords: cold mix asphalt, binder course, cement, stiffness modulus, water sensitivity
Procedia PDF Downloads 311182 Investigating the Properties of Asphalt Concrete Containing Recycled Fillers
Authors: Hasan Taherkhani
Abstract:
Increasingly accumulation of the solid waste materials has become a major environmental problem of communities. In addition to the protection of environment, the recycling and reusing of the waste materials are financially beneficial. Waste materials can be used in highway construction. This study aimed to investigate the applicability of recycled concrete, asphalt and steel slag powder, as a replacement of the primary mineral filler in asphalt concrete has been investigated. The primary natural siliceous aggregate filler, as control, has been replaced with the secondary recycled concrete, asphalt and steel slag powders, and some engineering properties of the mixtures have been evaluated. Marshal Stability, flow, indirect tensile strength, moisture damage, static creep and volumetric properties of the mixtures have been evaluated. The results show that, the Marshal Stability of the mixtures containing recycled powders is higher than that of the control mixture. The flow of the mixtures containing recycled steel slag is lower, and that of the mixtures containing recycled asphalt and cement concrete powder is found to be higher than that of the control mixture. It is also found that the resistance against moisture damage and permanent deformation of the mixture can be improved by replacing the natural filler with the recycled powders. The volumetric properties of the mixtures are not significantly influenced by replacing the natural filler with the recycled powders.Keywords: filler, steel slag, recycled concrete, recycled asphalt concrete, tensile strength, moisture damage, creep
Procedia PDF Downloads 277181 Application of Recycled Paper Mill Sludge on the Growth of Khaya Senegalensis and Its Effect on Soil Properties, Nutrients and Heavy Metals
Authors: A. Rosazlin Abdullah, I. Che Fauziah, K. Wan Rasidah, A. B. Rosenani
Abstract:
The paper industry performs an essential role in the global economy of the world. A study was conducted on the paper mill sludge that is applied on the Khaya senegalensis for 1 year planning period at University Agriculture Park, Puchong, Selangor, Malaysia to determine the growth of Khaya senegalensis, soil properties, nutrients concentrations and effects on the status of heavy metals. Paper Mill Sludge (PMS) and composted Recycled Paper Mill Sludge (RPMS) were used with different rates of nitrogen (0, 150, 300 and 600 kg ha-1) at the ratio of 1:1 (Recycled Paper Mill Sludge (RPMS) : Empty Fruit Brunch (EFB). The growth parameters were measured twice a month for 1 year. Plant nutrients and heavy metal uptake were determined. The paper mill sludge has the potential to be a supplementary N fertilizer as well as a soil amendment. The application of RPMS with N, significantly contributed to the improvement in plant growth parameters such as plant height (4.24 m), basal diameter (10.30 cm), total plant biomass and improved soil physical and chemical properties. The pH, EC, available P and total C in soil were varied among the treatments during the planting period. The treatments with raw and RPM compost had higher pH values than those applied with inorganic fertilizer and control. Nevertheless, there was no salinity problem recorded during the planting period and available P in soil treated with raw and RPMS compost was higher than the control plots that reflects the mineralization of organic P from the decomposition of pulp sludge. The weight of the free and occluded light fractions of carbon concentration was significantly higher in the soils treated with raw and RPMS compost. The application of raw and composted RPMS gave significantly higher concentration of the heavy metals, but the total concentrations of heavy metals in the soils were below the critical values. Hence, the paper mill sludge can be successfully used as soil amendment in acidic soil without any serious threat. The use of paper mill sludge for the soil fertility, shows improvement in land application signifies a unique opportunity to recycle sludge back to the land to alleviate the potential waste management problem.Keywords: growth, heavy metals, nutrients uptake, production, waste management
Procedia PDF Downloads 368180 Evaluation of Modulus of Elasticity by Non-Destructive Method of Hybrid Fiber Reinforced Concrete
Authors: Erjola Reufi, Thomas Beer
Abstract:
Plain, unreinforced concrete is a brittle material, with a low tensile strength, limited ductility and little resistance to cracking. In order to improve the inherent tensile strength of concrete there is a need of multi directional and closely spaced reinforcement, which can be provided in the form of randomly distributed fibers. Fiber reinforced concrete (FRC) is a composite material consisting of cement, sand, coarse aggregate, water and fibers. In this composite material, short discrete fibers are randomly distributed throughout the concrete mass. The behavioral efficiency of this composite material is far superior to that of plain concrete and many other construction materials of equal cost. The present experimental study considers the effect of steel fibers and polypropylene fiber on the modulus of elasticity of concrete. Hook end steel fibers of length 5 cm and 3 cm at volume fraction of 0.25%, 0.5% and 1.% were used. Also polypropylene fiber of length 12, 6, 3 mm at volume fraction 0.1, 0.25, and 0.4 % were used. Fifteen mixtures has been prepared to evaluate the effect of fiber on modulus of elasticity of concrete. Ultrasonic pulse velocity (UPV) and resonant frequency methods which are two non-destructive testing techniques have been used to measure the elastic properties of fiber reinforced concrete. This study found that ultrasonic wave propagation is the most reliable, easy and cost effective testing technique to use in the determination of the elastic properties of the FRC mix used in this study.Keywords: fiber reinforced concrete(FRC), polypropylene fiber, resonance, ultrasonic pulse velocity, steel fiber
Procedia PDF Downloads 302179 Valorization of Plastic and Cork Wastes in Design of Composite Materials
Authors: Svetlana Petlitckaia, Toussaint Barboni, Paul-Antoine Santoni
Abstract:
Plastic is a revolutionary material. However, the pollution caused by plastics damages the environment, human health and the economy of different countries. It is important to find new ways to recycle and reuse plastic material. The use of waste materials as filler and as a matrix for composite materials is receiving increasing attention as an approach to increasing the economic value of streams. In this study, a new composite material based on high-density polyethylene (HDPE) and polypropylene (PP) wastes from bottle caps and cork powder from unused cork (virgin cork), which has a high capacity for thermal insulation, was developed. The composites were prepared with virgin and modified cork. The composite materials were obtained through twin-screw extrusion and injection molding. The composites were produced with proportions of 0 %, 5 %, 10 %, 15 %, and 20 % of cork powder in a polymer matrix with and without coupling agent and flame retardant. These composites were investigated in terms of mechanical, structural and thermal properties. The effect of cork fraction, particle size and the use of flame retardant on the properties of composites were investigated. The properties of samples elaborated with the polymer and the cork were compared to them with the coupling agent and commercial flame retardant. It was observed that the morphology of HDPE/cork and PP/cork composites revealed good distribution and dispersion of cork particles without agglomeration. The results showed that the addition of cork powder in the polymer matrix reduced the density of the composites. However, the incorporation of natural additives doesn’t have a significant effect on water adsorption. Regarding the mechanical properties, the value of tensile strength decreases with the addition of cork powder, ranging from 30 MPa to 19 MPa for PP composites and from 19 MPa to 17 MPa for HDPE composites. The value of thermal conductivity of composites HDPE/cork and PP/ cork is about 0.230 W/mK and 0.170 W/mK, respectively. Evaluation of the flammability of the composites was performed using a cone calorimeter. The results of thermal analysis and fire tests show that it is important to add flame retardants to improve fire resistance. The samples elaborated with the coupling agent and flame retardant have better mechanical properties and fire resistance. The feasibility of the composites based on cork and PP and HDPE wastes opens new ways of valorizing plastic waste and virgin cork. The formulation of composite materials must be optimized.Keywords: composite materials, cork and polymer wastes, flammability, modificated cork
Procedia PDF Downloads 88178 Modeling and Estimating Reserve of the Ali Javad Porphyry Copper-Gold Deposit, East Azerbaijan, Iran
Authors: Behzad Hajalilou, Nasim Hajalilou, Saeid Ansari
Abstract:
The study area is located in East Azerbaijan province, north of Ahar city, and 1/100000 geological map of Varzgan. This region is located in the middle of Iran zone. Ali Javad Porphyry copper-gold ore deposit has been created in a magmatic complex containing intrusive masses, combining Granodiorite and quartz Monzonite that penetrates into the Eocene volcanic aggregate. The most important mineralization includes primary oxides minerals (magnetite), sulfide (pyrite, chalcopyrite, Molybdenite, Bornite, Chalcocite, Covollite), secondary oxide or hydroxide minerals (hematite, goethite, limonite), and carbonate (malachite and Azurite). The mineralization forms into the vein-veinlets and scattered system. The alterations observed in the region include intermediate Argillic, advanced Argillic, Phyllic, silica, Propylitic, chlorite and Potassic. The 3D model of mineralization of the Alijavad is provided by Data DATAMINE software and based on the study of 700 polished sections of 32 drilled boreholes in the region. This model is completely compatible with the model provided by Lowell and Gilbert for the mineralization of porphyry copper deposits of quartz Monzonite type. The estimated cumulative residual value of copper for Ali Javad deposit is 81.5 million tons with 0.75 percent of copper, and for gold is 8.37 million tons with 1.8 ppm.Keywords: porphyry copper, mineralization, Ali Javad, modeling, reserve estimation
Procedia PDF Downloads 220177 Effect of Permeability Reducing Admixture Utilization on Sulfate Resistance of Self-Consolidating Concrete Mixture
Authors: Ali Mardani-Aghabaglou, Zia Ahmad Faqiri, Semsi Yazici
Abstract:
In this study, the effect of permeability reducing admixture (PRA) utilization on fresh properties, compressive strength and sulfate resistance of self-consolidating concrete (SSC) were investigated. For this aim, two different commercial PRA were used at two utilization ratios as %0.1 and %0.2 wt. CEM I 42.5 R type cement and crushed limestone aggregate having Dmax of 15 mm were used for preparing of SCC mixtures. In all mixtures, cement content, water/cement ratio, and flow value were kept constant as 450 kg, 0.40 and 65 ± 2 cm, respectively. In order to obtain desired flow value, a polycarboxylate ether-based high range water reducing admixture was used at different content. T50 flow time, flow value, L-box, and U-funnel of SCC mixture were measured as fresh properties. 1, 3, 7 and 28-day compressive strength of SCC mixture were obtained on 150 mm cubic specimens. To investigate the sulfate resistance of SCC mixture 75x75x285 mm prismatic specimens were produced. After 28-day water curing, specimens were immersed in %5 sodium sulfate solution during 210 days. The length change of specimens was measured at 5-day time intervals up to 210 days. According to the test results, all fresh properties of SCC mixtures were in accordance with the European federation of specialist construction chemicals and concrete systems (EFNARC) critter for SCC mixtures. The utilization of PRA had no significant effect on compressive strength and fresh properties of SCC mixtures. Regardless of PRA type, sulfate resistance of SCC mixture increased by adding of PRA into the SCC mixtures. The length changes of the SCC mixtures containing %1 and %2 PRA were measured as %8 and %14 less than that of control mixture containing no PRA, respectively.Keywords: permeability reducing admixture, self-consolidating concrete, fresh properties, sulfate resistance
Procedia PDF Downloads 157176 Biogeography Based CO2 and Cost Optimization of RC Cantilever Retaining Walls
Authors: Ibrahim Aydogdu, Alper Akin
Abstract:
In this study, the development of minimizing the cost and the CO2 emission of the RC retaining wall design has been performed by Biogeography Based Optimization (BBO) algorithm. This has been achieved by developing computer programs utilizing BBO algorithm which minimize the cost and the CO2 emission of the RC retaining walls. Objective functions of the optimization problem are defined as the minimized cost, the CO2 emission and weighted aggregate of the cost and the CO2 functions of the RC retaining walls. In the formulation of the optimum design problem, the height and thickness of the stem, the length of the toe projection, the thickness of the stem at base level, the length and thickness of the base, the depth and thickness of the key, the distance from the toe to the key, the number and diameter of the reinforcement bars are treated as design variables. In the formulation of the optimization problem, flexural and shear strength constraints and minimum/maximum limitations for the reinforcement bar areas are derived from American Concrete Institute (ACI 318-14) design code. Moreover, the development length conditions for suitable detailing of reinforcement are treated as a constraint. The obtained optimum designs must satisfy the factor of safety for failure modes (overturning, sliding and bearing), strength, serviceability and other required limitations to attain practically acceptable shapes. To demonstrate the efficiency and robustness of the presented BBO algorithm, the optimum design example for retaining walls is presented and the results are compared to the previously obtained results available in the literature.Keywords: bio geography, meta-heuristic search, optimization, retaining wall
Procedia PDF Downloads 400175 Integrating Circular Economy Framework into Life Cycle Analysis: An Exploratory Study Applied to Geothermal Power Generation Technologies
Authors: Jingyi Li, Laurence Stamford, Alejandro Gallego-Schmid
Abstract:
Renewable electricity has become an indispensable contributor to achieving net-zero by the mid-century to tackle climate change. Unlike solar, wind, or hydro, geothermal was stagnant in its electricity production development for decades. However, with the significant breakthrough made in recent years, especially the implementation of enhanced geothermal systems (EGS) in various regions globally, geothermal electricity could play a pivotal role in alleviating greenhouse gas emissions. Life cycle assessment has been applied to analyze specific geothermal power generation technologies, which proposed suggestions to optimize its environmental performance. For instance, selecting a high heat gradient region enables a higher flow rate from the production well and extends the technical lifespan. Although such process-level improvements have been made, the significance of geothermal power generation technologies so far has not explicitly displayed its competitiveness on a broader horizon. Therefore, this review-based study integrates a circular economy framework into life cycle assessment, clarifying the underlying added values for geothermal power plants to complete the sustainability profile. The derived results have provided an enlarged platform to discuss geothermal power generation technologies: (i) recover the heat and electricity from the process to reduce the fossil fuel requirements; (ii) recycle the construction materials, such as copper, steel, and aluminum for future projects; (iii) extract the lithium ions from geothermal brine and make geothermal reservoir become a potential supplier of the lithium battery industry; (iv) repurpose the abandoned oil and gas wells to build geothermal power plants; (v) integrate geothermal energy with other available renewable energies (e.g., solar and wind) to provide heat and electricity as a hybrid system at different weather; (vi) rethink the fluids used in stimulation process (EGS only), replace water with CO2 to achieve negative emissions from the system. These results provided a new perspective to the researchers, investors, and policymakers to rethink the role of geothermal in the energy supply network.Keywords: climate, renewable energy, R strategies, sustainability
Procedia PDF Downloads 137174 Islamophobia, Years After 9/11: An Assessment of the American Media
Authors: Nasa'i Muhammad Gwadabe
Abstract:
This study seeks to find the extent to which the old Islamophobic prejudice was tilted towards a more negative direction in the United States following the 9/11 terrorist attacks. It is hypothesized that, the 9/11 attacks in the United States reshaped the old Islamophobic prejudice through the reinforcement of a strong social identity construction of Muslims as “out-group”. The “social identity” and “discourse representation” theories are used as framework for analysis. To test the hypothesis, two categories were created: the prejudice (out-group) and the tolerance (in-group) categories. The Prejudice (out-group) against Muslims category was coded to include six attributes: (Terrorist, Threat, Women's Rights violation, Undemocratic, Backward and Intolerant); while the tolerance (In-group) for Muslims category was also coded to include six attributes: (Peaceful, civilized, educated, partners trustworthy and honest). Data are generated from the archives of three American newspapers: The Los Angeles Times, New York Times and USA Today using specific search terms and specific date range; from 9/11/1996 to 9/11/2006, that is five years before and five years after the 9/11. An aggregate of 20595 articles were generated from the search of the three newspapers throughout the search periods. Conclusively, for both pre and post 9/11 periods, the articles generated under the category of prejudice (out-group) against Muslims revealed a higher frequency, against that of tolerance (in-group) for them, which is lesser. Finally, The comparison between the pre and post 9/11 periods showed that, the increased Prejudice (out-group) against Muslims was most influenced through libeling them as terrorist, which signaled a skyrocketed increase from pre to post 9/11.Keywords: in-group, Islam, Islamophobia, Muslims, out-group, prejudice, terrorism, the 9/11 and tolerance
Procedia PDF Downloads 305173 Regression Approach for Optimal Purchase of Hosts Cluster in Fixed Fund for Hadoop Big Data Platform
Authors: Haitao Yang, Jianming Lv, Fei Xu, Xintong Wang, Yilin Huang, Lanting Xia, Xuewu Zhu
Abstract:
Given a fixed fund, purchasing fewer hosts of higher capability or inversely more of lower capability is a must-be-made trade-off in practices for building a Hadoop big data platform. An exploratory study is presented for a Housing Big Data Platform project (HBDP), where typical big data computing is with SQL queries of aggregate, join, and space-time condition selections executed upon massive data from more than 10 million housing units. In HBDP, an empirical formula was introduced to predict the performance of host clusters potential for the intended typical big data computing, and it was shaped via a regression approach. With this empirical formula, it is easy to suggest an optimal cluster configuration. The investigation was based on a typical Hadoop computing ecosystem HDFS+Hive+Spark. A proper metric was raised to measure the performance of Hadoop clusters in HBDP, which was tested and compared with its predicted counterpart, on executing three kinds of typical SQL query tasks. Tests were conducted with respect to factors of CPU benchmark, memory size, virtual host division, and the number of element physical host in cluster. The research has been applied to practical cluster procurement for housing big data computing.Keywords: Hadoop platform planning, optimal cluster scheme at fixed-fund, performance predicting formula, typical SQL query tasks
Procedia PDF Downloads 232172 Analysis of Trends and Challenges of Using Renewable Biomass for Bioplastics
Authors: Namasivayam Navaranjan, Eric Dimla
Abstract:
The world needs more quality food, shelter and transportation to meet the demands of growing population and improving living standard of those who currently live below the poverty line. Materials are essential commodities for various applications including food and pharmaceutical packaging, building and automobile. Petroleum based plastics are widely used materials amongst others for these applications and their demand is expected to increase. Use of plastics has environment related issues because considerable amount of plastic used worldwide is disposed in landfills, where its resources are wasted, the material takes up valuable space and blights communities. Some countries have been implementing regulations and/or legislations to increase reuse, recycle, renew and remanufacture materials as well as to minimise the use of non-environmentally friendly materials such as petroleum plastics. However, issue of material waste is still a concern in the countries who have low environmental regulations. Development of materials, mostly bioplastics from renewable biomass resources has become popular in the last decade. It is widely believed that the potential for up to 90% substitution of total plastics consumption by bioplastics is technically possible. The global demand for bioplastics is estimated to be approximately six times larger than in 2010. Recently, standard polymers like polyethylene (PE), polypropylene (PP), Polyvinyl Chloride (PVC) or Polyethylene terephthalate (PET), but also high-performance polymers such as polyamides or polyesters have been totally or partially substituted by their renewable equivalents. An example is Polylactide (PLA) being used as a substitute in films and injection moulded products made of petroleum plastics, e.g. PET. The starting raw materials for bio-based materials are usually sugars or starches that are mostly derived from food resources, partially also recycled materials from food or wood processing. The risk in lower food availability by increasing price of basic grains as a result of competition with biomass-based product sectors for feedstock also needs to be considered for the future bioplastic production. Manufacturing of bioplastic materials is often still reliant upon petroleum as an energy and materials source. Life Cycle Assessment (LCA) of bioplastic products has being conducted to determine the sustainability of a production route. However, the accuracy of LCA depends on several factors and needs improvement. Low oil price and high production cost may also limit the technically possible growth of these plastics in the coming years.Keywords: bioplastics, plastics, renewable resources, biomass
Procedia PDF Downloads 308171 Hydraulic Conductivity Prediction of Cement Stabilized Pavement Base Incorporating Recycled Plastics and Recycled Aggregates
Authors: Md. Shams Razi Shopnil, Tanvir Imtiaz, Sabrina Mahjabin, Md. Sahadat Hossain
Abstract:
Saturated hydraulic conductivity is one of the most significant attributes of pavement base course. Determination of hydraulic conductivity is a routine procedure for regular aggregate base courses. However, in many cases, a cement-stabilized base course is used with compromised drainage ability. Traditional hydraulic conductivity testing procedure is a readily available option which leads to two consequential drawbacks, i.e., the time required for the specimen to be saturated and extruding the sample after completion of the laboratory test. To overcome these complications, this study aims at formulating an empirical approach to predicting hydraulic conductivity based on Unconfined Compressive Strength test results. To do so, this study comprises two separate experiments (Constant Head Permeability test and Unconfined Compressive Strength test) conducted concurrently on a specimen having the same physical credentials. Data obtained from the two experiments were then used to devise a correlation between hydraulic conductivity and unconfined compressive strength. This correlation in the form of a polynomial equation helps to predict the hydraulic conductivity of cement-treated pavement base course, bypassing the cumbrous process of traditional permeability and less commonly used horizontal permeability tests. The correlation was further corroborated by a different set of data, and it has been found that the derived polynomial equation is deemed to be a viable tool to predict hydraulic conductivity.Keywords: hydraulic conductivity, unconfined compressive strength, recycled plastics, recycled concrete aggregates
Procedia PDF Downloads 90170 3G or 4G: A Predilection for Millennial Generation of Indian Society
Authors: Rishi Prajapati
Abstract:
3G is the abbreviation of third generation of wireless mobile telecommunication technologies. 3G is a mode that finds application in wireless voice telephony, mobile internet access, fixed wireless internet access, video calls and mobile TV. It also provides mobile broadband access to smartphones and mobile modems in laptops and computers. The first 3G networks were introduced in 1998, followed by 4G networks in 2008. 4G is the abbreviation of fourth generation of wireless mobile telecommunication technologies. 4G is termed to be the advanced form of 3G. 4G was firstly introduced in South Korea in 2007. Many abstracts have floated researches that depicted the diversity and similarity between the third and the fourth generation of wireless mobile telecommunications technology, whereas this abstract reflects the study that focuses on analyzing the preference between 3G versus 4G given by the elite group of the Indian society who are known as adolescents or the Millennial Generation aging from 18 years to 25 years. The Millennial Generation was chosen for this study as they have the easiest access to the latest technology. A sample size of 200 adolescents was selected and a structured survey was carried out which had several closed ended as well as open ended questions, to aggregate the result of this study. It was made sure that the effect of environmental factors on the subjects was as minimal as possible. The data analysis comprised of primary data collection reflecting it as quantitative research. The rationale behind this research is to give brief idea of how 3G and 4G are accepted by the Millennial Generation in India. The findings of this research would materialize a framework which depicts whether Millennial Generation would prefer 4G over 3G or vice versa.Keywords: fourth generation, wireless telecommunication technology, Indian society, millennial generation, market research, third generation
Procedia PDF Downloads 270169 Households’ Willingness to Pay for Watershed Management Practices in Lake Hawassa Watershed, Southern Ethiopia
Authors: Mulugeta Fola, Mengistu Ketema, Kumilachew Alamerie
Abstract:
Watershed provides vast economic benefits within and beyond the management area of interest. But most watersheds in Ethiopia are increasingly facing the threats of degradation due to both natural and man-made causes. To reverse these problems, communities’ participation in sustainable management programs is among the necessary measures. Hence, this study assessed the households’ willingness to pay for watershed management practices through a contingent valuation study approach. Double bounded dichotomous choice with open-ended follow-up format was used to elicit the households’ willingness to pay. Based on data collected from 275 randomly selected households, descriptive statistics results indicated that most households (79.64%) were willing to pay for watershed management practices. A bivariate Probit model was employed to identify determinants of households’ willingness to pay and estimate mean willingness to pay. Its result shows that age, gender, income, livestock size, perception of watershed degradation, social position, and offered bids were important variables affecting willingness to pay for watershed management practices. The study also revealed that the mean willingness to pay for watershed management practices was calculated to be 58.41 Birr and 47.27 Birr per year from the double bounded and open-ended format, respectively. The study revealed that the aggregate welfare gains from watershed management practices were calculated to be 931581.09 Birr and 753909.23 Birr per year from double bounded dichotomous choice and open-ended format, respectively. Therefore, the policymakers should make households to pay for the services of watershed management practices in the study area.Keywords: bivariate probit model, contingent valuation, watershed management practices, willingness to pay
Procedia PDF Downloads 224168 Estimation of Asphalt Pavement Surfaces Using Image Analysis Technique
Authors: Mohammad A. Khasawneh
Abstract:
Asphalt concrete pavements gradually lose their skid resistance causing safety problems especially under wet conditions and high driving speeds. In order to enact the actual field polishing and wearing process of asphalt pavement surfaces in a laboratory setting, several laboratory-scale accelerated polishing devices were developed by different agencies. To mimic the actual process, friction and texture measuring devices are needed to quantify surface deterioration at different polishing intervals that reflect different stages of the pavement life. The test could still be considered lengthy and to some extent labor-intensive. Therefore, there is a need to come up with another method that can assist in investigating the bituminous pavement surface characteristics in a practical and time-efficient test procedure. The purpose of this paper is to utilize a well-developed image analysis technique to characterize asphalt pavement surfaces without the need to use conventional friction and texture measuring devices in an attempt to shorten and simplify the polishing procedure in the lab. Promising findings showed the possibility of using image analysis in lieu of the labor-sensitive-variable-in-nature friction and texture measurements. It was found that the exposed aggregate surface area of asphalt specimens made from limestone and gravel aggregates produced solid evidence of the validity of this method in describing asphalt pavement surfaces. Image analysis results correlated well with the British Pendulum Numbers (BPN), Polish Values (PV) and Mean Texture Depth (MTD) values.Keywords: friction, image analysis, polishing, statistical analysis, texture
Procedia PDF Downloads 306167 Functionalized Titanium Dioxide Nanoparticles for Targeting and Disrupting Amyloid Fibrils
Authors: Elad Arad, Raz Jelinek, Hanna Rapaport
Abstract:
Amyloidoses are a family of diseases characterized by abnormal protein folding that leads to aggregation. They accumulate to form fibrillar plaques which are implicated in the pathogenesis of Alzheimer, prion, diabetes type II and other diseases. To the best of our knowledge, despite extensive research efforts devoted to plaque aggregates inhibition, there is yet no cure for this phenomenon. Titanium and its alloys are found in growing interest for biomedical applications. Variety of surface modifications enable porous, adhesive, bioactive coatings for its surface. Titanium oxides (titania) are also being developed for photothermal and photodynamic treatments. Inspired by this, we set to explore the effect of functionalized titania nanoparticles in combination with external stimuli, as potential photothermal ablating agents against amyloids. Titania nanoparticles were coated with bi-functional catechol derivatives (dihydroxy-phenylalanine propanoic acid, noted DPA) to gain targeting properties. In conjunction with UV-radiation, these nanoparticles may selectively destroy the vicinity of their target. Titania modified 5 nm nanoparticles coated with DPA were further conjugated to the amyloid-targeting Congo Red (CR). These Titania-DPA-CR nanoparticles were found to target mature amyloid fibril of both amyloid-β (Aβ 1-42 a.a). Moreover, irradiation of the peptides in presence of the modified nanoparticles decreased the aggregate content and oligomer fraction. This work provides insights into the use of modified titania nanoparticles for amyloid plaque targeting and photothermal destruction. It may shed light on future modifications and functionalization of titania nanoparticles for different applications.Keywords: titanium dioxide, amyloids, photothermal treatment, catechol, Congo-red
Procedia PDF Downloads 146166 Sensitivity Analysis of the Heat Exchanger Design in Net Power Oxy-Combustion Cycle for Carbon Capture
Authors: Hirbod Varasteh, Hamidreza Gohari Darabkhani
Abstract:
The global warming and its impact on climate change is one of main challenges for current century. Global warming is mainly due to the emission of greenhouse gases (GHG) and carbon dioxide (CO2) is known to be the major contributor to the GHG emission profile. Whilst the energy sector is the primary source for CO2 emission, Carbon Capture and Storage (CCS) are believed to be the solution for controlling this emission. Oxyfuel combustion (Oxy-combustion) is one of the major technologies for capturing CO2 from power plants. For gas turbines, several Oxy-combustion power cycles (Oxyturbine cycles) have been investigated by means of thermodynamic analysis. NetPower cycle is one of the leading oxyturbine power cycles with almost full carbon capture capability from a natural gas fired power plant. In this manuscript, sensitivity analysis of the heat exchanger design in NetPower cycle is completed by means of process modelling. The heat capacity variation and supercritical CO2 with gaseous admixtures are considered for multi-zone analysis with Aspen Plus software. It is found that the heat exchanger design has a major role to increase the efficiency of NetPower cycle. The pinch-point analysis is done to extract the composite and grand composite curve for the heat exchanger. In this paper, relationship between the cycle efficiency and the minimum approach temperature (∆Tmin) of the heat exchanger has also been evaluated. Increase in ∆Tmin causes a decrease in the temperature of the recycle flue gases (RFG) and an overall decrease in the required power for the recycled gas compressor. The main challenge in the design of heat exchangers in power plants is a tradeoff between the capital and operational costs. To achieve lower ∆Tmin, larger size of heat exchanger is required. This means a higher capital cost but leading to a better heat recovery and lower operational cost. To achieve this, ∆Tmin is selected from the minimum point in the diagrams of capital and operational costs. This study provides an insight into the NetPower Oxy-combustion cycle’s performance analysis and operational condition based on its heat exchanger design.Keywords: carbon capture and storage, oxy-combustion, netpower cycle, oxy turbine cycles, zero emission, heat exchanger design, supercritical carbon dioxide, oxy-fuel power plant, pinch point analysis
Procedia PDF Downloads 204165 Co-Alignment of Comfort and Energy Saving Objectives for U.S. Office Buildings and Restaurants
Authors: Lourdes Gutierrez, Eric Williams
Abstract:
Post-occupancy research shows that only 11% of commercial buildings met the ASHRAE thermal comfort standard. Many buildings are too warm in winter and/or too cool in summer, wasting energy and not providing comfort. In this paper, potential energy savings in U.S. offices and restaurants if thermostat settings are calculated according the updated ASHRAE 55-2013 comfort model that accounts for outdoor temperature and clothing choice for different climate zones. eQUEST building models are calibrated to reproduce aggregate energy consumption as reported in the U.S. Commercial Building Energy Consumption Survey. Changes in energy consumption due to the new settings are analyzed for 14 cities in different climate zones and then the results are extrapolated to estimate potential national savings. It is found that, depending on the climate zone, each degree increase in the summer saves 0.6 to 1.0% of total building electricity consumption. Each degree the winter setting is lowered saves 1.2% to 8.7% of total building natural gas consumption. With new thermostat settings, national savings are 2.5% of the total consumed in all office buildings and restaurants, summing up to national savings of 69.6 million GJ annually, comparable to all 2015 total solar PV generation in US. The goals of improved comfort and energy/economic savings are thus co-aligned, raising the importance of thermostat management as an energy efficiency strategy.Keywords: energy savings quantifications, commercial building stocks, dynamic clothing insulation model, operation-focused interventions, energy management, thermal comfort, thermostat settings
Procedia PDF Downloads 302164 Value Generation of Construction and Demolition Waste Originated in the Building Rehabilitation to Improve Energy Efficiency; From Waste to Resources
Authors: Mercedes Del Rio Merino, Jaime Santacruz Astorqui, Paola Villoria Saez, Carmen Viñas Arrebola
Abstract:
The lack of treatment of the waste from construction and demolition waste (CDW) is a problem that must be solved immediately. It is estimated that in the world not to use CDW generates an increase in the use of new materials close to 20% of the total value of the materials used. The problem is even greater in case these wastes are considered hazardous because the final deposition of them may also generate significant contamination. Therefore, the possibility of including CDW in the manufacturing of building materials, represents an interesting alternative to ensure their use and to reduce their possible risk. In this context and in the last years, many researches are being carried out in order to analyze the viability of using CDW as a substitute for the traditional raw material of high environmental impact. Even though it is true, much remains to be done, because these works generally characterize materials but not specific applications that allow the agents of the construction to have the guarantees required by the projects. Therefore, it is necessary the involvement of all the actors included in the life cycle of these new construction materials, and also to promote its use for, for example, definition of standards, tax advantages or market intervention is necessary. This paper presents the main findings reached in "Waste to resources (W2R)" project since it began in October 2014. The main goal of the project is to develop new materials, elements and construction systems, manufactured from CDW, to be used in improving the energy efficiency of buildings. Other objectives of the project are: to quantify the CDW generated in the energy rehabilitation works, specifically wastes from the building envelope; and to study the traceability of CDW generated and promote CDW reuse and recycle in order to get close to the life cycle of buildings, generating zero waste and reducing the ecological footprint of the construction sector. This paper determines the most important aspects to consider during the design of new constructive solutions, which improve the energy efficiency of buildings and what materials made with CDW would be the most suitable for that. Also, a survey to select best practices for reducing "close to zero waste" in refurbishment was done. Finally, several pilot rehabilitation works conform the parameters analyzed in the project were selected, in order to apply the results and thus compare the theoretical with reality. Acknowledgements: This research was supported by the Spanish State Secretariat for Research, Development and Innovation of the Ministry of Economy and Competitiveness under "Waste 2 Resources" Project (BIA2013-43061-R).Keywords: building waste, construction and demolition waste, recycling, resources
Procedia PDF Downloads 250163 Multi-Stream Graph Attention Network for Recommendation with Knowledge Graph
Abstract:
In recent years, Graph neural network has been widely used in knowledge graph recommendation. The existing recommendation methods based on graph neural network extract information from knowledge graph through entity and relation, which may not be efficient in the way of information extraction. In order to better propose useful entity information for the current recommendation task in the knowledge graph, we propose an end-to-end Neural network Model based on multi-stream graph attentional Mechanism (MSGAT), which can effectively integrate the knowledge graph into the recommendation system by evaluating the importance of entities from both users and items. Specifically, we use the attention mechanism from the user's perspective to distil the domain nodes information of the predicted item in the knowledge graph, to enhance the user's information on items, and generate the feature representation of the predicted item. Due to user history, click items can reflect the user's interest distribution, we propose a multi-stream attention mechanism, based on the user's preference for entities and relationships, and the similarity between items to be predicted and entities, aggregate user history click item's neighborhood entity information in the knowledge graph and generate the user's feature representation. We evaluate our model on three real recommendation datasets: Movielens-1M (ML-1M), LFM-1B 2015 (LFM-1B), and Amazon-Book (AZ-book). Experimental results show that compared with the most advanced models, our proposed model can better capture the entity information in the knowledge graph, which proves the validity and accuracy of the model.Keywords: graph attention network, knowledge graph, recommendation, information propagation
Procedia PDF Downloads 117162 Experimental Study on Heat and Mass Transfer of Humidifier for Fuel Cell
Authors: You-Kai Jhang, Yang-Cheng Lu
Abstract:
Major contributions of this study are threefold: designing a new model of planar-membrane humidifier for Proton Exchange Membrane Fuel Cell (PEMFC), an index to measure the Effectiveness (εT) of that humidifier, and an air compressor system to replicate related planar-membrane humidifier experiments. PEMFC as a kind of renewable energy has become more and more important in recent years due to its reliability and durability. To maintain the efficiency of the fuel cell, the membrane of PEMFC need to be controlled in a good hydration condition. How to maintain proper membrane humidity is one of the key issues to optimize PEMFC. We developed new humidifier to recycle water vapor from cathode air outlet so as to keep the moisture content of cathode air inlet in a PEMFC. By measuring parameters such as dry side air outlet dew point temperature, dry side air inlet temperature and humidity, wet side air inlet temperature and humidity, and differential pressure between dry side and wet side, we calculated indices obtained by dew point approach temperature (DPAT), water flux (J), water recovery ratio (WRR), effectiveness (εT), and differential pressure (ΔP). We discussed six topics including sealing effect, flow rate effect, flow direction effect, channel effect, temperature effect, and humidity effect by using these indices. Gas cylinders are used as sources of air supply in many studies of humidifiers. Gas cylinder depletes quickly during experiment at 1kW air flow rate, and it causes replication difficult. In order to ensure high stable air quality and better replication of experimental data, this study designs an air supply system to overcome this difficulty. The experimental result shows that the best rate of pressure loss of humidifier is 0.133×10³ Pa(g)/min at the torque of 25 (N.m). The best humidifier performance ranges from 30-40 (LPM) of air flow rates. The counter flow configured humidifies moisturizes the dry side inlet air more effectively than the parallel flow humidifier. From the performance measurements of the channel plates various rib widths studied in this study, it is found that the narrower the rib width is, the more the performance of humidifier improves. Raising channel width in same hydraulic diameter (Dh ) will obtain higher εT and lower ΔP. Moreover, increasing the dry side air inlet temperature or humidity will lead to lower εT. In addition, when the dry side air inlet temperature exceeds 50°C, the effect becomes even more obvious.Keywords: PEM fuel cell, water management, membrane humidifier, heat and mass transfer, humidifier performance
Procedia PDF Downloads 176161 Soil Degradation Processes in Marginal Uplands of Samar Island, Philippines
Authors: Dernie Taganna Olguera
Abstract:
Marginal uplands are fragile ecosystems in the tropics that need to be evaluated for sustainable utilization and land degradation mitigation. Thus, this study evaluated the dominant soil degradation processes in selected marginal uplands of Samar Island, Philippines; evaluated the important factors influencing soil degradation in the selected sites and identified the indicators of soil degradation in marginal uplands of the tropical landscape of Samar Island, Philippines. Two (2) sites were selected (Sta. Rita, Samar and Salcedo, Eastern, Samar) representing the western and eastern sides of Samar Island respectively. These marginal uplands represent different agro-climatic zones suitable for the study. Soil erosion is the major soil degradation process in the marginal uplands studied. It resulted in not only considerable soil losses but nutrient losses as well. Soil erosion varied with vegetation cover and site. It was much higher in the sweetpotato, cassava, and gabi crops than under natural vegetation. In addition, soil erosion was higher in Salcedo than in Sta. Rita, which is related to climatic and soil characteristics. Bulk density, porosity, aggregate stability, soil pH, organic matter, and carbon dioxide evolution are good indicators of soil degradation. The dominance of Saccharum spontaneum Linn., Imperata cylindrica Linn, Melastoma malabathricum Linn. and Psidium guajava Linn indicated degraded soil condition. Farmer’s practices particularly clean culture and organic fertilizer application influenced the degree of soil degradation in the marginal uplands of Samar Island, Philippines.Keywords: soil degradation, soil erosion, marginal uplands, Samar island, Philippines
Procedia PDF Downloads 419