Search results for: compact thermal storage

Authors: Tai Yuan Yu, Pei-Jen Wang

Abstract:

Oil-free turbomachinery is considered one of the critical technologies for future green power generation systems as rotor machinery systems. Oil-free technology allows clean, compact, and maintenance-free working, and gas foil bearings, abbreviated as GFBs, are important for the technology. Since the first applications in the auxiliary power units and air cycle machines in the 1970s, obvious improvement has been created to the computational models for dynamic rotor behavior. However, many technical issues are still poorly understood or remain unsolved, and some of those are thermal management and the pattern of how pressure will be distributed in bearing clearance. This paper presents a three-dimensional, abbreviated as 3D, fluid-structure interaction model of single pad foil bearings and three pad foil bearings to predict bearing working behavior that researchers could compare characteristics of those. The coupling analysis model involves dynamic working characteristics applied to all the gas film and mechanical structures. Therefore, the elastic deformation of foil structure and the hydrodynamic pressure of gas film can both be calculated by a finite element method program. As a result, the temperature distribution pattern could also be iteratively solved by coupling analysis. In conclusion, the working fluid state in a gas film of various pad forms of bearings working characteristic at constant rotational speed for both can be solved for comparisons with the experimental results.

Keywords: fluid-structure interaction, multi-physics simulations, gas foil bearing, oil-free, transient thermo-hydrodynamic

Procedia PDF Downloads 157

Authors: Bayarjargal Enkhtaivan, Gao Wei, Zhang Yanping, He Guo Qiang

Abstract:

In our study, traditional cleaning mirror technology with reduced consumption of water in solar thermal power plants is investigated. In developed countries, a significant increase of growth and innovation in solar thermal power sector is evident since over the last decade. These power plants required higher water consumption, however, there are some complications to construct and operate such power plants under severe drought-inflicted areas like deserts where high water-deficit can be seen but sufficient solar energy is available. Designing new experimental equipments is the most important advantage of this study. These equipments can estimate various types of measurements at the mean time. In this study, Glasses were placed for 10 and 20 days at certain positions to deposit dusts on glass surface by using a common method. Dust deposited on glass surface was washed by experimental equipment and measured dust deposition on each glass. After that, experimental results were analyzed and concluded.

Keywords: concentrated solar power (CSP) plant, high-pressure water, test equipment of clean mirror, cleaning technology of glass and mirror

Procedia PDF Downloads 164

Authors: Marjan Javanmard

Abstract:

The rheological properties of dairy products critically depend on the underlying organisation of proteins at multiple length scales. When heated and acidified, milk proteins form particle gel that is viscoelastic, solvent rich, ‘soft’ material. In this work recent developments on the rheology of soft particles suspensions were used to interpret and potentially define the properties of dairy gel structures. It is discovered that at volume fractions below random close packing (RCP), the Maron-Pierce-Quemada (MPQ) model accurately predicts the viscosity of the dairy gel suspensions without fitting parameters; the MPQ model has been shown previously to provide reasonable predictions of the viscosity of hard sphere suspensions from the volume fraction, solvent viscosity and RCP. This surprising finding demonstrates that up to RCP, the dairy gel system behaves as a hard sphere suspension and that the structural aggregates behave as discrete particulates akin to what is observed for microgel suspensions. At effective phase volumes well above RCP, the system is a soft solid. In this region, it is discovered that the storage modulus of the sheared AMG scales with the storage modulus of the set gel. The storage modulus in this regime is reasonably well described as a function of effective phase volume by the Evans and Lips model. Findings of this work has potential to aid in rational design and control of dairy food structure-properties.

Keywords: dairy suspensions, rheology-structure, Maron-Pierce-Quemada Model, Evans and Lips Model

Procedia PDF Downloads 209

Authors: Burak Erkayman

Abstract:

The manufacturing and service organizations are in the need of using ERP systems to integrate many functions from purchasing to storage, production planning to calculation of costs. Using ERP systems by the integration in the level of information provides companies remarkable advantages in terms of profitability, productivity and efficiency in processes. Cloud computing is one of the most significant changes in information and communication technology. The developments in Cloud Computing attract business world to take advantage of this field. Cloud Computing means much more storage area, more cost saving and faster data transfer rate. In addition to these, it presents new business models, new field of study and practicable solutions for anyone’s use. These developments make inevitable the implementation of ERP systems to cloud environment. In this study, the performance of ERP systems in cloud environment is analyzed through various performance criteria and a comparison between traditional and cloud-ERP systems is presented. At the end of study the transformation and the future of ERP systems is discussed.

Keywords: cloud-ERP, ERP system performance, information system transformation

Procedia PDF Downloads 521

Authors: N. Demirsoy, N. Uçar, A. Önen, N. Kızıldağ, Ö. F. Vurur, O. Eren, İ. Karacan

Abstract:

Polymer composite nano-fibers including (1, 3 wt %) silver nano-particles have been produced by electrospinning method. Polyacrylonitrile/N,N-dimethylformamide (PAN/DMF) solution has been prepared and the amount of silver nitrate has been adjusted to PAN weight. Silver nano-particles were obtained from reduction of silver ions into silver nano-particles by chemical reduction by hydrazine hydroxide (N2H5OH). The different amount of silver salt was loaded into polymer matrix to obtain polyacrylonitrile composite nano-fiber containing silver nano-particles. The effect of the amount of silver nano-particles on the properties of composite nano-fiber web was investigated. Electrical conductivity, mechanical properties, thermal properties were examined by Microtest LCR Meter 6370 (0.01 mΩ-100 MΩ), tensile tester, differential scanning calorimeter DSC (Q10) and SEM, respectively. Also, antimicrobial efficiency test (ASTM E2149-10) was done against Staphylococcus aureus bacteria. It has been seen that breaking strength, conductivity, antimicrobial effect, enthalpy during cyclization increase by use of silver nano-particles while the diameter of nano-fiber decreases.

Keywords: composite polyacrylonitrile nanofiber, electrical conductivity, electrospinning, mechanical properties, thermal properties, silver nanoparticles

Procedia PDF Downloads 405

Authors: Ismail Rahama Adam Hamid

Abstract:

This paper presents the development of a thermal model for a flat, double-sided linear generator designed for use in free-piston engines. The study conducted in this paper examines the influence of temperature on the performance of the permeant magnet linear generator, an integral and pivotal component within the system. This research places particular emphasis on the Neodymium Iron Boron (NdFeB) permanent magnet, which serves as a source of magnetic field for the linear generator. In this study, an internal combustion engine that tends to produce heat is connected to a generator. Considering the temperatures rise from both the combustion process and the thermal contributions of current-carrying conductors and frictional forces. Utilizing Computational Fluid Dynamics (CFD) method, a thermal model of the (NdFeB) magnet within the linear generator is constructed and analyzed. Furthermore, the temperature field is examined to ensure that the linear generator operates under stable conditions without the risk of demagnetization.

Keywords: free piston engine, permanent magnet, linear generator, demagnetization, simulation

Procedia PDF Downloads 37

Authors: Rajat Jain, Himanshu Pandey, Somesh Mehta, Pravin P. Patil

Abstract:

Formula SAE cars are the student designed and fabricated formula prototype cars, designed according to SAE INTERNATIONAL design rules which compete in the various national and international events. This paper shows a FEM based comparative study of free vibration analysis of different mode shapes of a formula prototype car chassis frame. Tubing sections of different diameters as per the design rules are designed in such a manner that the desired strength can be achieved. Natural frequency of first five mode was determined using finite element analysis method. SOLIDWORKS is used for designing the frame structure and SOLIDWORKS SIMULATION and ANSYS WORKBENCH 16.2 are used for the modal analysis. Mode shape results of ANSYS and SOLIDWORKS were compared. Fixed –fixed boundary conditions are used for fixing the A-arm wishbones. The simulation results were compared for the validation of the study. First five modes were compared and results were found within the permissible limits. The AISI4130 (CROMOLY- chromium molybdenum steel) material is used and the chassis frame is discretized with fine quality QUAD mesh followed by Fixed-fixed boundary conditions. The natural frequency of the chassis frame is 53.92-125.5 Hz as per the results of ANSYS which is found within the permissible limits. The study is concluded with the light weight and compact chassis frame without compensation with strength. This design allows to fabricate an extremely safe driver ergonomics, compact, dynamically stable, simple and light weight tubular chassis frame with higher strength.

Keywords: FEM, modal analysis, formula SAE cars, chassis frame, Ansys

Procedia PDF Downloads 327

Authors: Kelaiaia Mounia Samira, Labar Hocine, Mesbah Tarek, Kelaiaia samia

Abstract:

The photovoltaic panel produces green power, and because of its availability across the globe, it can supply isolated loads (site away of the electrical network or difficult of access). Unfortunately this energy remains very expensive. The most application of these types of power needs storage devices, the Lithium batteries are commonly used because of its powerful storage capability. Using a solar panel or an array of panels without a controller that can perform MPPT will often result in wasted power, which results in the need to install more panels for the same power requirement. For devices that have the battery connected directly to the panel, this will also result in premature battery failure or capacity loss. In this paper it is proposed a modified P&O algorithm for the MPPT which takes in account the battery’s internal resistance vs temperature and stage of charging. Of course the temperature variation and irradiation of the PV panel are also introduced.

Keywords: modeling, battery, MPPT, charging, PV Panel

Procedia PDF Downloads 512

Authors: Simran Kaur, Paul J. Van Geel

Abstract:

A coupled Thermal-Mechanical-Biological (TMB) model was developed for the analysis of impacts of temperatures on waste stabilization at a Municipal Solid Waste (MSW) landfill in Quebec, Canada using COMSOL Multiphysics, a finite element-based software. For waste placed in landfills in Northern climates during winter months, it can take months or even years before the waste approaches ideal temperatures for biodegradation to occur. Therefore, the proposed model links biodegradation induced strain in MSW to waste temperatures and corresponding heat generation rates as a result of anaerobic degradation. This provides a link between the thermal-biological and mechanical behavior of MSW. The thermal properties of MSW are further linked to density which is tracked and updated in the mechanical component of the model, providing a mechanical-thermal link. The settlement of MSW is modelled based on the concept of viscoelasticity. The specific viscoelastic model used is a single Kelvin – Voight viscoelastic body in which the finite element response is controlled by the elastic material parameters – Young’s Modulus and Poisson’s ratio. The numerical model was validated with 10 years of temperature and settlement data collected from a landfill in Ste. Sophie, Quebec. The coupled TMB modelling framework, which simulates placement of waste lifts as they are placed progressively in the landfill, allows for optimization of several thermal and mechanical parameters throughout the depth of the waste profile and helps in better understanding of temperature dependence of MSW stabilization. The model is able to illustrate how waste placed in the winter months can delay biodegradation-induced settlement and generation of landfill gas. A delay in waste stabilization will impact the utilization of the approved airspace prior to the placement of a final cover and impact post-closure maintenance. The model provides a valuable tool to assess different waste placement strategies in order to increase airspace utilization within landfills operating under different climates, in addition to understanding conditions for increased gas generation for recovery as a green and renewable energy source.

Keywords: coupled model, finite element modeling, landfill, municipal solid waste, waste stabilization

Procedia PDF Downloads 122

Authors: Ahmadreza Hakiminejad, Changfeng Fu, Hamideh Mohammadzadeh Titkanlou

Abstract:

For decades, sustainable development has been an imperative concern in the process of urban development of the world’s developed countries. Despite the fact that the concept of sustainability, primarily, emerged by virtue of warning over global environmental catastrophes, it subsequently led to the ongoing debates not only over environmental, but also economic and sociocultural issues involved. This study, particularly, discusses the constituents of social sustainability– as one of the three pillars of sustainable development– and its situation within an urban context. It tries to investigate the interrelationships between the elements of social sustainability and the quality of physical environment. The paper, firstly, depicts a theoretical overview of the notions of social sustainability and urban form. Secondly, it will discuss the interrelationship between the two. And lastly, it will investigate and analyse this interrelationship through the historical transformation of Iranian cities. The research aims to answer this very question that how the urban form within the context of the built environment can influence the social behaviors so as to achieve a more sustainable society. It is to examine how and why compact, high-density and mixed-use urban patterns are environmentally sound, efficient for transport, socially beneficial and economically viable. The methodology used in this paper is desk research. Thus, the documents from different urban related disciplines including urban planning, urban design, urban sociology and urban policy have been reviewed. The research has also applied a comparative approach to discuss and analyse the impacts of different urban forms on the elements of social sustainability within the context of modern and traditional Iranian cities. The paper concludes with an examination of possible future directions of Iranian cities with consideration to socio-cultural concepts and the challenges that will have to be overcome to make progress towards social sustainability.

Keywords: social sustainability, urban form, compact city, Iranian cities

Procedia PDF Downloads 401

Authors: Thomas Weber, Nina Strobel, Thomas Kohne, Eberhard Abele

Abstract:

In context of the energy transition in Germany, the importance of so-called virtual power plants in the energy supply continues to increase. The progressive dismantling of the large power plants and the ongoing construction of many new decentralized plants result in great potential for optimization through synergies between the individual plants. These potentials can be exploited by mathematical optimization algorithms to calculate the optimal application planning of decentralized power and heat generators and storage systems. This also includes linear or linear mixed integer optimization. In this paper, procedures for reducing the number of decision variables to be calculated are explained and validated. On the one hand, this includes combining n similar installation types into one aggregated unit. This aggregated unit is described by the same constraints and target function terms as a single plant. This reduces the number of decision variables per time step and the complexity of the problem to be solved by a factor of n. The exact operating mode of the individual plants can then be calculated in a second optimization in such a way that the output of the individual plants corresponds to the calculated output of the aggregated unit. Another way to reduce the number of decision variables in an optimization problem is to reduce the number of time steps to be calculated. This is useful if a high temporal resolution is not necessary for all time steps. For example, the volatility or the forecast quality of environmental parameters may justify a high or low temporal resolution of the optimization. Both approaches are examined for the resulting calculation time as well as for optimality. Several optimization models for virtual power plants (combined heat and power plants, heat storage, power storage, gas turbine) with different numbers of plants are used as a reference for the investigation of both processes with regard to calculation duration and optimality.

Keywords: CHP, Energy 4.0, energy storage, MILP, optimization, virtual power plant

Procedia PDF Downloads 162

Authors: O. Rahli, N. Mimouni, R. Bennacer, K. Bouhadef

Abstract:

This numerical study investigates the travelling wave’s appearance and the behavior of Poiseuille-Rayleigh-Benard (PRB) flow induced in 3D thermosolutale mixed convection (TSMC) in horizontal rectangular channels. The governing equations are discretized by using a control volume method with third order Quick scheme in approximating the advection terms. Simpler algorithm is used to handle coupling between the momentum and continuity equations. To avoid the excessively high computer time, full approximation storage (FAS) with full multigrid (FMG) method is used to solve the problem. For a broad range of dimensionless controlling parameters, the contribution of this work is to analyzing the flow regimes of the steady longitudinal thermoconvective rolls (noted R//) for both thermal and mass transfer (TSMC). The transition from the opposed volume forces to cooperating ones, considerably affects the birth and the development of the longitudinal rolls. The heat and mass transfers distribution are also examined.

Keywords: heat and mass transfer, mixed convection, poiseuille-rayleigh-benard flow, rectangular duct

Procedia PDF Downloads 290

Authors: Anvesh Rajak

Abstract:

This is a new innovation that can be developed. Here I am going to use the waste heat of air conditioner so as to produce the electricity by using the Stirling engine because this waste heat creates the thermal pollution in the environment. The waste heat from the air conditioners has caused a temperature rise of 1°–2°C or more on weekdays in the Tokyo office areas. This heating promotes the heat-island phenomenon in Tokyo on weekdays. Now these air conditioners creates the thermal pollution in the environment and hence rising the temperature of the environment. Air conditioner generally emit the waste heat air whose temperature is about 50°C which heat the environment. Today the demand of energy is increasing tremendously, but available energy lacks in supply. Hence, there is no option for proper and efficient utilization and conservation of energy. In this paper the main stress is given on energy conservation by using technique of utilizing waste heat from Air-conditioning system. Actually the focus is on the use of the waste heat rather than improving the COP of the air- conditioners; if also we improve the COP of air conditioners gradually it would emit some waste heat so I want that waste heat to be used up. As I have used air conditioner’s waste heat to produce electricity so similarly there are various other appliances which emit the waste heat in the surrounding so here also we could use the Stirling engines and Geothermal heat pump concept to produce the electricity and hence can reduce the thermal pollution in the environment.

Keywords: stirling engine, geothermal heat pumps, waste heat, air conditioners

Procedia PDF Downloads 346

Authors: Mohammad B. HabibiNajafi, Saeideh Sadat Fatemizadeh, Maryam Tavakoli

Abstract:

In recent years, the consumption of functional foods, including foods containing probiotic bacteria, has come to notice. Milk proteins have been identified as a source of angiotensin-I-converting enzyme )ACE( inhibitory peptides and are currently the best-known class of bioactive peptides. In this study, the effects of adding prebiotic ingredients (inulin and wheat fiber) and fat percentage (0%, 2% and 3.5%) in yogurt containing probiotic Lactobacillus casei on physicochemical properties, degree of proteolysis, antioxidant and ACE-inhibitory activity within 21 days of storage at 5 ± 1 °C were evaluated. The results of statistical analysis showed that the application of prebiotic compounds led to a significant increase in water holding capacity, proteolysis and ACE-inhibitory of samples. The degree of proteolysis in yogurt increases as storage time elapses (P < 0.05) but when proteolysis exceeds a certain threshold, this trend begins to decline. Also, during storage time, water holding capacity reduced initially but increased thereafter. Moreover, based on our findings, the survival of Lactobacillus casei in samples treated with inulin and wheat fiber increased significantly in comparison to the control sample (P < 0.05) whereas the effect of fat percentage on the survival of probiotic bacteria was not significant (P = 0.095). Furthermore, the effect of prebiotic ingredients and the presence of probiotic cultures on the antioxidant activity of samples was significant (P < 0.05).

Keywords: probiotic yogurt, proteolysis, ACE-inhibitory, antioxidant activity

Procedia PDF Downloads 239

Authors: Omid Saligheh

Abstract:

Poly (tri methylene terephthalate) (PTT) nanofibers were prepared by electrospinning, being directly deposited in the form of a random fibers web. The effect of changing processing parameters such as solution concentration and electrospinning voltage on the morphology of the electrospun PTT nanofibers was investigated with scanning electron microscopy (SEM). The electrospun fibers diameter increased with rising concentration and decreased by increasing the electrospinning voltage, thermal and mechanical properties of electrospun fibers were characterized by DSC and tensile testing, respectively.

Keywords: poly tri methylene terephthalate, electrospinning, morphology, thermal behavior, mechanical properties

Procedia PDF Downloads 79

Authors: Yuri Zinchenko

Abstract:

Recently, distributed storage systems have been used more and more in various aspects of everyday life. They provide such necessary properties as Scalability, Fault Tolerance, Durability, and others. At the same time, not only reliable but also fast data storage remains one of the most pressing issues in this area. That brings us to the consensus algorithm as one of the most important components that has a great impact on the functionality of a distributed system. This paper is the result of an analysis of several well-known consensus algorithms, such as Paxos and Raft. The algorithm it offers, called Sync, promotes, but does not insist on simultaneous writing to the nodes (which positively affects the overall writing speed) and tries to minimize the system's inactive time. This allows nodes to reach agreement on the system state in a shorter period, which is a critical factor for distributed systems. Also when developing Sync, a lot of attention was paid to such criteria as simplicity and intuitiveness, the importance of which is difficult to overestimate.

Keywords: sync, consensus algorithm, distributed system, leader-based, synchronization.

Procedia PDF Downloads 49

Authors: Mohd Zamri Che Wanik

Abstract:

This paper presents the management of the Fault Ride Through event within a Solar Farm during a grid fault. The modeling and simulation of a photovoltaic (PV) with battery energy storage connected to the power network will be described. The modeling approach and the study analysis performed are described. The model and operation scenarios are simulated using a digital simulator for different scenarios. The dynamic response of the system when subjected to sudden self-clearance temporary fault is presented. The capability of the PV system and battery storage riding through the power system fault and, at the same time, supporting the local grid by injecting fault current is demonstrated. For each case, the different control methods to achieve the objective of supporting the grid according to grid code requirements are presented and explained. The inverter modeling approach is presented and described.

Keywords: faut ride through, solar farm, grid code, power network

Procedia PDF Downloads 42

Authors: Prajakta Katti, Suryasarathi Bose, S. Kumar

Abstract:

In this work, carboxyl functionalized multiwall carbon nanotubes (a-MWNTs) covalently grafted with hydroxylated functionalized poly (ether ether ketone), HPEEK, which is miscible with the pre-polymer (epoxy) through the esterification reaction. The functionalized MWNTs were systematically characterized using spectroscopic techniques. The epoxy composites containing a-MWNTs and HPEEK grafted multiwall carbon nanotubes (HPEEK-g-MWNTs) were formulated using mechanical stirring coupled with a bath sonicator to improve the dispersion property of the nanoparticles and were subsequently cured at 80 ̊C and post cured at 180 ̊C. With the addition of 0.5 wt% of HPEEK-g-MWNTs, an impressive 44% enhancement in the storage modulus, 22% increase in tensile strength and 38% increase in fracture toughness was observed with respect to neat epoxy. In addition to these mechanical properties, the epoxy composites displayed significant enhancement in the hardness without reducing thermal stability. These improved properties were attributed to the tailored interface between HPEEK-MWNTs and epoxy matrix.

Keywords: epoxy, MWNTs, HPEEK-g-MWNTs, tensile properties, nanoindentation, fracture toughness

Procedia PDF Downloads 295

Authors: E. Cuevas, M. Feigel'man, L. Ioffe, M. Mezard

Abstract:

The origin of continuous energy spectrum in large disordered interacting quantum systems is one of the key unsolved problems in quantum physics. While small quantum systems with discrete energy levels are noiseless and stay coherent forever in the absence of any coupling to external world, most large-scale quantum systems are able to produce thermal bath, thermal transport and excitation decay. This intrinsic decoherence is manifested by a broadening of energy levels which acquire a finite width. The important question is: What is the driving force and mechanism of transition(s) between two different types of many-body systems - with and without decoherence and thermal transport? Here, we address this question via two complementary approaches applied to the same model of quantum spin-1/2 system with XY-type exchange interaction and random transverse field. Namely, we develop analytical theory for this spin model on a Bethe lattice and implement numerical study of exact level statistics for the same spin model on random graph. This spin model is relevant to the study of pseudogaped superconductivity and S-I transition in some amorphous materials.

Keywords: strongly correlated electrons, quantum phase transitions, superconductor, insulator

Procedia PDF Downloads 570

Authors: Iftikhar Hussain, Muhammad Ahmad, Xi Chen, Li Yuxiang

Abstract:

Transition metal phosphides and phosphates are newly emerged electrode material candidates in energy storage devices. For the first time, we report uniformly distributed, interconnected, and well-aligned two-dimensional nanosheets made from trimetallic Zn-Co-Ga phosphate (ZCGP) electrode materials with preserved crystal phase. It is found that the ZCGP electrode material exhibits about 2.85 and 1.66 times higher specific capacity than mono- and bimetallic phosphate electrode materials at the same current density. The trimetallic ZCGP electrode exhibits superior conductivity, lower internal resistance (IR) drop, and high Coulombic efficiency compared to mono- and bimetallic phosphate. The charge storage mechanism is studied for mono- bi- and trimetallic electrode materials, which illustrate the diffusion-dominated battery-type behavior. By means of density functional theory (DFT) calculations, ZCGP shows superior metallic conductivity due to the modified exchange splitting originating from 3d-orbitals of Co atoms in the presence of Zn and Ga. Moreover, a hybrid supercapacitor (ZCGP//rGO) device is engineered, which delivered a high energy density (ED) of 40 W h kg⁻¹ and a high-power density (PD) of 7,745 W kg⁻¹, lighting 5 different colors of light emitting diodes (LEDs). These outstanding results confirm the promising battery-type electrode materials for energy storage applications.

Keywords: trimetallic phosphate, nanosheets, DFT calculations, hybrid supercapacitor, binder-free, synergistic effect

Procedia PDF Downloads 197

Authors: Khairul Bariah Sulaiman, Tajul Aris Yang

Abstract:

Malaysian dried cocoa beans have been reported to have low quality flavour and are often sold at discounted prices. Various efforts have been made to improve the Malaysian beans quality. Among these efforts is introduction of the shallow box fermentation technique and pulp preconditioned through pods storage. However, after nearly four decades of the effort was done, Malaysian cocoa farmers still received lower prices for their beans. So, this study was carried out in order to assess the flavour quality of dried cocoa beans produced by shallow box fermentation techniques, combination of shallow box fermentation with pods storage and compared to dried cocoa beans obtained from Ghana. A total of eight samples of dried cocoa was used in this study, which one of the samples was Ghanaian beans (coded with no.8), while the rest were Malaysian cocoa beans with different post-harvest processing (coded with no. 1, 2, 3, 4, 5, 6 and 7). Cocoa liquor was prepared from all samples in the prescribed techniques and sensory evaluation was carried out using Quantitative Descriptive Analysis (QDA) Method with 0-10 scale by Malaysian Cocoa Board trained panelist. Sensory evaluation showed that cocoa attributes for all cocoa liquors ranging from 3.5 to 5.3, whereas bitterness was ranging from 3.4 to 4.6 and astringent attribute ranging from 3.9 to 5.5, respectively. Meanwhile, all cocoa liquors were having acid or sourness attribute ranging from 1.6 to 3.6, respectively. In general cocoa liquor prepared from sample coded no 4 has almost similar flavour profile and no significantly different at p < 0.05 with Ghana, in term of most flavour attributes as compared to the other six samples.

Keywords: cocoa beans, flavour, fermentation, shallow box, pods storage

Procedia PDF Downloads 378

Authors: Steffen Illig, Alexander S. Eggeman, Alessandro Troisi, Stephen G. Yeates, John E. Anthony, Henning Sirringhaus

Abstract:

Large-amplitude intermolecular vibrations in combination with complex shaped transfer integrals generate a thermally fluctuating energetic landscape. The resulting dynamic disorder and its intrinsic presence in organic semiconductors is one of the most fundamental differences to their inorganic counterparts. Dynamic disorder is believed to govern many of the unique electrical and optical properties of organic systems. However, the low energy nature of these vibrations makes it difficult to access them experimentally and because of this we still lack clear molecular design rules to control and reduce dynamic disorder. Applying a novel technique based on electron diffraction we encountered strong intermolecular, thermal vibrations in every single organic material we studied (14 up to date), indicating that a large degree of dynamic disorder is a universal phenomenon in organic crystals. In this paper a new molecular design strategy will be presented to avoid dynamic disorder. We found that small molecules that have their side chains attached to the long axis of their conjugated core have been found to be less likely to suffer from dynamic disorder effects. In particular, we demonstrate that 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothio-phene (C8-BTBT) and 2,9-di-decyl-dinaphtho-[2,3-b:20,30-f]-thieno-[3,2-b]-thiophene (C10DNTT) exhibit strongly reduced thermal vibrations in comparison to other molecules and relate their outstanding performance to their lower dynamic disorder. We rationalize the low degree of dynamic disorder in C8-BTBT and C10-DNTT with a better encapsulation of the conjugated cores in the crystal structure which helps reduce large amplitude thermal motions. The work presented in this paper provides a general strategy for the design of new classes of very high mobility organic semiconductors with low dynamic disorder.

Keywords: charge transport, C8-BTBT, C10-DNTT, dynamic disorder, organic semiconductors, thermal vibrations

Procedia PDF Downloads 390

Authors: F. Pottmeyer, M. Weispfenning, K. A. Weidenmann

Abstract:

Continuous carbon fiber reinforced plastics (CFRP) exhibit a high application potential for lightweight structures due to their outstanding specific mechanical properties. Embedded metal elements, so-called inserts, can be used to join structural CFRP parts. Drilling of the components to be joined can be avoided using inserts. In consequence, no bearing stress is anticipated. This is a distinctive benefit of embedded inserts, since continuous CFRP have low shear and bearing strength. This paper aims at the investigation of the load bearing capacity after preinduced damages from impact tests and thermal-cycling. In addition, characterization of mechanical properties during dynamic high speed pull-out testing under different loading velocities was conducted. It has been shown that the load bearing capacity increases up to 100% for very high velocities (15 m/s) in comparison with quasi-static loading conditions (1.5 mm/min). Residual strength measurements identified the influence of thermal loading and preinduced mechanical damage. For both, the residual strength was evaluated afterwards by quasi-static pull-out tests. Taking into account the DIN EN 6038 a high decrease of force occurs at impact energy of 16 J with significant damage of the laminate. Lower impact energies of 6 J, 9 J, and 12 J do not decrease the measured residual strength, although the laminate is visibly damaged - distinguished by cracks on the rear side. To evaluate the influence of thermal loading, the specimens were placed in a climate chamber and were exposed to various numbers of temperature cycles. One cycle took 1.5 hours from -40 °C to +80 °C. It could be shown that already 10 temperature cycles decrease the load bearing capacity up to 20%. Further reduction of the residual strength with increasing number of thermal cycles was not observed. Thus, it implies that the maximum damage of the composite is already induced after 10 temperature cycles.

Keywords: composite, joining, inserts, dynamic loading, thermal loading, residual strength, impact

Procedia PDF Downloads 270

Authors: A. Alharbi, R. Boukhanouf, T. Habeebullah, H. Ibrahim

Abstract:

This paper presents a detailed description of evaporative cooling systems used for space cooling in Mina Valley, Saudi Arabia. The thermal performance and environmental impact of the evaporative coolers were evaluated. It was found that the evaporative cooling systems used for space cooling in pilgrims’ accommodations and in the train stations could reduce energy consumption by as much as 75% and cut carbon dioxide emission by 78% compared to traditional vapour compression systems.

Keywords: evaporative cooling, vapor compression, electricity consumption, CO2 emission

Procedia PDF Downloads 419

Authors: Johannes Bibinger, Sebastian Eibl, Hans-Joachim Gudladt

Abstract:

This study considers the influence of different irradiation scenarios on the thermal degradation of carbon fiber-reinforced polymers (CFRP). Real threats are simulated, such as fires with long-lasting low heat fluxes and nuclear heat flashes with short-lasting high heat fluxes. For this purpose, coated and uncoated quasi-isotropic samples of the commercially available CFRP HexPly® 8552/IM7 are thermally irradiated from one side by a cone calorimeter and a xenon short-arc lamp with heat fluxes between 5 and 175 W/cm² at varying time intervals. The specimen temperature is recorded on the front and backside as well as at different laminate depths. The CFRP is non-destructively tested with ultrasonic testing, infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and micro-focused computed X-Ray tomography (μCT). Destructive tests are performed to evaluate the mechanical properties in terms of interlaminar shear strength (ILSS), compressive and tensile strength. The irradiation scenarios vary significantly in heat flux and exposure time. Thus, different heating rates, radiation effects, and temperature distributions occur. This leads to unequal decomposition processes, which affect the sensitivity of the strength type and damage behaviour of the specimens. However, with the use of surface coatings, thermal degradation of composite materials can be delayed.

Keywords: CFRP, one-sided thermal damage, high heat flux, heating rate, non-destructive and destructive testing

Procedia PDF Downloads 99

Authors: Michel A. Thomet

Abstract:

A discrete-event simulation model was used to perform a Reliability-Availability-Maintainability (RAM) study of a large petrochemical complex which included sixteen process units, and seven feeds and intermediate streams. All the feeds and intermediate streams have associated storage tanks, so that if a processing unit fails and shuts down, the downstream units can keep producing their outputs. This also helps the upstream units which do not have to reduce their outputs, but can store their excess production until the failed unit restart. Each process unit and each pipe section carrying the feeds and intermediate streams has a probability of failure with an associated distribution and a Mean Time Between Failure (MTBF), as well as a distribution of the time to restore and a Mean Time To Restore (MTTR). The utilities supporting the process units can also fail and have their own distributions with specific MTBF and MTTR. The model runs are for ten years or more and the runs are repeated several times to obtain statistically relevant results. One of the main results is the On-Stream factor (OSF) of each process unit (percent of hours in a year when the unit is running in nominal conditions). One of the objectives of the study was to investigate if the storage capacity of each of the feeds and the intermediate stream was adequate. This was done by increasing the storage capacities in several steps and through running the simulation to see if the OSF were improved and by how much. Other objectives were to see if the failure of the utilities were an important factor in the overall OSF, and what could be done to reduce their failure rates through redundant equipment.

Keywords: business continuity, on-stream factor, petrochemical, RAM study, simulation, MTBF

Procedia PDF Downloads 208

Authors: U. Farooq, A. Samson, V. Thangadurai, R. Edwards

Abstract:

In recent years, an impressive research has been conducted to introduce the solid-state electrolytes for the future energy storage devices like Li-ion batteries more specifically. In this work we tried to prepare a ceramic electrolyte (Li6.5 La2.5 Ba0.5 Nb Zr O12(LLBNZO)) and sintered the pallets of as-prepared material at elevated temperature like 1050, 1100, 1150 and 1200 °C. The objective to carry out this research was to observe the effect of temperature on porosity, density and transport properties of materials. Preliminary results suggest that the material sintered at higher temperature could show enhanced performance in terms of fast ionic transport. This enhancement in performance can be attributed to low porosity of materials which is result of high temperature sintering.

Keywords: solid state battery, electrolyte, garnet structures, Li-ion battery

Procedia PDF Downloads 262

Authors: Miguel Angel Calvo Salve

Abstract:

Building enclosures and façades not only have an aesthetic component they must also ensure thermal comfort and improve the acoustics and air quality in buildings. The role of facades design, its assemblies, and construction are key in developing a greener future in architecture. This research and study focus on the design of a multi-leaves building envelope, with a self-supporting wall of granite slabs. The study will demonstrate the advantages of its use in compare with the hanging stone veneer in a vented cladding system. Using the Design of the School of Music and Theatre of the Atlantic Area in Spain as a case study where the multi-leaves enclosure system consists in a self-supported outer leaf of large granite slabs of 15cm. of thickness, a vent cavity with thermal isolation, a brick wall, and a series of internal layers. The methodology used were simulations and data collected in building. The advantages of the self-supporting wall of granite slabs in the outer leaf (15cm). compared with a hanging stone veneer in a vented cladding system can summarize the goals as follows: Using the stone in more natural way, by compression. The weight of the stone slabs goes directly to a strip-footing and don't overload the reinforced concrete structure of the building. The weight of the stone slabs provides an external aerial soundproofing, preventing the sound transmission to the structure. The thickness of the stone slabs is enough to provide the external waterproofing of the building envelope. The self-supporting system with minimum anchorages allows having a continuous and external thermal isolation without thermal bridges. The thickness of ashlars masonry provides a thermal inertia that balances the temperatures between day and night in the external thermal insulation layer. The absence of open joints gives the quality of a continuous envelope transmitting the sensations of the stone, the heaviness in the facade, the rhythm of the music and the sequence of the theatre. The main cost of stone due his bigger thickness is more than compensated with the reduction in assembly costs. Don´t need any substructure systems for hanging stone veneers.

Keywords: self-supporting wall, stone cladding systems, hanging veneer cladding systems, sustainability of facade systems

Procedia PDF Downloads 48

Authors: Sanchita Baitalik, Nijhuma Kayal, Omprakash Chakrabarti

Abstract:

Recently SiC ceramics have been a focus of interest in the field of porous materials due to their unique combination of properties and hence they are considered as an ideal candidate for catalyst supports, thermal insulators, high-temperature structural materials, hot gas particulate separation systems etc. in different industrial processes. Several processing methods are followed for fabrication of porous SiC at low temperatures but all these methods are associated with several disadvantages. Therefore processing of porous SiC ceramics at low temperatures is still challenging. Concerning that of incorporation of secondary bond phase additives by an infiltration technique should result in a homogenous distribution of bond phase in the final ceramics. Present work is aimed to synthesis cordierite (2MgO.2Al2O3.5SiO2) bonded porous SiC ceramics following incorporation of sol-gel bond phase precursor into powder compacts of SiC and heat treating the infiltrated body at 1400 °C. In this paper the primary aim was to study the effect of infiltration of a precursor sol of cordierite into a porous SiC powder compact prepared with pore former of different particle sizes on the porosity, pore size, microstructure and the mechanical properties of the porous SiC ceramics. Cordierite sol was prepared by mixing a solution of magnesium nitrate hexahydrate and aluminium nitrate nonahydrate in 2:4 molar ratio in ethanol another solution containing tetra-ethyl orthosilicate and ethanol in 1:3 molar ratio followed by stirring for several hours. Powders of SiC (α-SiC; d50 =22.5 μm) and 10 wt. % polymer microbead of two sizes 8 and 50µm as the pore former were mixed in a suitable liquid medium, dried and pressed in the form of bars (50×20×16 mm3) at 23 MPa pressure. The well-dried bars were heat treated at 1100° C for 4 h with a hold at 750 °C for 2 h to remove the pore former. Bars were evacuated for 2 hr upto 0.3 mm Hg pressure into a vacuum chamber and infiltrated with cordierite precursor sol. The infiltrated samples were dried and the infiltration process was repeated until the weight gain became constant. Finally the infiltrated samples were sintered at 1400 °C to prepare cordierite bonded porous SiC ceramics. Porous ceramics prepared with 8 and 50 µm sized microbead exhibited lower oxidation degrees of respectively 7.8 and 4.8 % than the sample (23 %) prepared with no microbead. Depending on the size of pore former, the porosity of the final ceramic varied in the range of 36 to 40 vol. % with a variation of flexural strength from 33.7 to 24.6 MPa. XRD analysis showed major crystalline phases of the ceramics as SiC, SiO2 and cordierite. Two forms of cordierite, α-(hexagonal) and µ-(cubic), were detected by the XRD analysis. The SiC particles were observed to be bonded both by cristobalite with fish scale morphology and cordierite with rod shape morphology and thereby formed a porous network. The material and mechanical properties of cordierite bonded porous SiC ceramics are good in agreement to carry out further studies like thermal shock, corrosion resistance etc.

Keywords: cordierite, infiltration technique, porous ceramics, sol-gel

Procedia PDF Downloads 267

Authors: Ilham ihoume, Rachid Tadili, Nora Arbaoui

Abstract:

This study examines the manner in which a solar copper coil heating system performs in a North-South-oriented greenhouse environment. In order to retain heat during the day and release it back ‎into the greenhouse environment at night, this system relies on the circulation of water in a closed ‎loop under the roof of the greenhouse. Experimental research ‎was conducted to compare the results in two identical greenhouses. The first one has a heating system, whilst the second one ‎has not and is regarded as a control. We determined the mass of the heat transfer fluid, which ‎makes up the storage system, needed to heat the greenhouse during the night to be equivalent to ‎‎689 Kg using the heat balance of the greenhouse equipped with a heating system. The findings ‎demonstrated that when compared to a controlled greenhouse without a heating system, the climatic ‎conditions within the experimental greenhouse were greatly enhanced by the solar heating system. ‎‎

Keywords: renewable energy, storage, enviromental impact, heating, agricultural greenhouse

Procedia PDF Downloads 68