Search results for: 40-storied RC core wall building

Authors: Muizz Sanni-Anibire

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The 21st century has witnessed growing concerns for the protection of built facilities against natural and man-made disasters. Studies in earthquake resistant buildings, fire, and explosion resistant buildings now dominate the arena. To protect people and facilities from the effects of the explosion, reinforced concrete walls have been designed to be blast resistant. Understanding the performance of these walls is a key step in ensuring the safety of built facilities. Blast walls are mostly designed using simple techniques such as single degree of freedom (SDOF) method, despite the increasing use of multi-degree of freedom techniques such as the finite element method. This study is the first stage of a continuous research into the safety and reliability of blast walls. It presents the SDOF approach applied to the analysis of a concrete wall panel under three representative bomb situations. These are motorcycle 50 kg, car 400kg and also van with the capacity of 1500 kg of TNT explosive.

Keywords: blast wall, safety, protection, explosion

Procedia PDF Downloads 244

Authors: Mahrooz Abed, Amir R. Masoodi

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Many structural lateral systems are used in tall buildings such as rigid frames, braced frames, shear walls, tubular structures and core structures. Some efficient structures for drift control and base moment reduction in tall buildings is outrigger and belt truss systems. When adopting outrigger beams in building design, their location should be in an optimum position for an economical design. A range of different strategies has been employed to identify the optimum locations of these outrigger beams under wind load. However, there is an absence of scientific research or case studies dealing with optimum outrigger location using buckling analysis. In this paper, one outrigger system is considered at the middle of height of structure. The optimum location of outrigger will be found based on the buckling load limitation. The core of structure is modeled by a clamped tapered beam. The exact stiffness matrix of tapered beam is formulated based on the Euler-Bernoulli theory. Finally, based on the buckling load of structure, the optimal location of outrigger will be found.

Keywords: tall buildings, outrigger system, buckling load, second-order effects, Euler-Bernoulli beam theory

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Authors: Carmen Viñas Arrebola, Antonio Rodriguez Sanchez, Sheila Varela Lujan, Mariano Gonzalez Cortina, Cesar Porras Amores

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The research group TEMA from the School of Building (UPM) is working in the line of energy efficiency and comfort in building. The need to reduce energy consumption in the building construction implies designing new constructive systems. These systems help to reduce both consumption and energy losses in order to achieve adequate thermal comfort for people in any type of building. In existing buildings the best option is the rehabilitation focused on thermal insulation. The aim of this paper is to design, monitor and analyze the first results of thermal behavior of the ETICS system in façades. This retrofitting solution consists of adding thermal insulation on the outside of the building, helping to create a continuous envelope on the façades. The analysis is done by comparing a rehabilitated part of the building with ETICS system and another part which has not been rehabilitated, and it is taken as reference. Both of them have the same characteristics. Temperature measurements were taken with type K thermocouples according to the previous design of the monitoring and in the same period of time. The pilot building of the study is situated in Benimamet Street, in San Cristobal de Los Ángeles, in the south of Madrid. It was built in the late 50s. The 51st entrance hall, which is restored, and the 47th entrance hall, in original conditions, have been studied.

Keywords: comfort in building, energy efficiency in building, ETICS, thermal properties

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Authors: Wai Ho Darrell Kwok

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Building entities are valuable assets of a society, however, all of them are suffered from the ravages of weather and time. Facilitating onerous maintenance activities is the only way to either maintain or enhance the value and contemporary standard of the premises. By the way, maintenance budget is always bounded by the corresponding threshold limit. In order to optimize the limited resources allocation in carrying out maintenance, there is a substantial need to prioritize maintenance work. This paper reveals the application of Fuzzy AHP in a Facilities Management Company determining the maintenance priorities on the basis of predetermined criteria, viz., Building Status (BS), Effects on Fabrics (EF), Effects on Sustainability (ES), Effects on Users (EU), Importance of Usage (IU) and Physical Condition (PC) in dealing with categorized 8 predominant building components maintenance aspects for building premises. From the case study, it is found that ‘building exterior repainting or re-tiling’, ‘spalling concrete repair works among exterior area’ and ‘lobby renovation’ are the top three maintenance priorities from facilities manager and maintenance expertise personnel. Through the application of the Fuzzy AHP for maintenance priorities decision algorithm, a more systemic and easier comparing scalar linearity factors being explored even in considering other multiple criteria decision scenarios of building maintenance issue.

Keywords: building maintenance, fuzzy AHP, maintenance priority, multi-criteria decision making

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Authors: C. Lanzerstorfer, M. Hinterberger

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The iron content of the ore used is crucial for the productivity and coke consumption rate in blast furnace pig iron production. Therefore, most iron ore deposits are processed in beneficiation plants to increase the iron content and remove impurities. In several comminution stages, the particle size of the ore is reduced to ensure that the iron oxides are physically liberated from the gangue. Subsequently, physical separation processes are applied to concentrate the iron ore. The fine-grained ore concentrates produced need to be transported, stored, and processed. For smooth operation of these processes, the flow properties of the material are crucial. The flowability of powders depends on several properties of the material: grain size, grain size distribution, grain shape, and moisture content of the material. The flowability of powders can be measured using ring shear testers. In this study, the influence of the moisture content on the flowability for the Krivoy Rog magnetite iron ore concentrate was investigated. Dry iron ore concentrate was mixed with varying amounts of water to produce samples with a moisture content in the range of 0.2 to 12.2%. The flowability of the samples was investigated using a Schulze ring shear tester. At all measured values of the normal stress (1.0 kPa – 20 kPa), the flowability decreased significantly from dry ore to a moisture content of approximately 3-5%. At higher moisture contents, the flowability was nearly constant, while at the maximum moisture content the flowability improved for high values of the normal stress only. The results also showed an improving flowability with increasing consolidation stress for all moisture content levels investigated. The wall friction angle of the dust with carbon steel (S235JR), and an ultra-high molecule low-pressure polyethylene (Robalon) was also investigated. The wall friction angle increased significantly from dry ore to a moisture content of approximately 3%. For higher moisture content levels, the wall friction angles were nearly constant. Generally, the wall friction angle was approximately 4° lower at the higher wall normal stress.

Keywords: iron ore concentrate, flowability, moisture content, wall friction angle

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Authors: Mohammad Zamani, Ramin Mansouri

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Spillways are one of the most important hydraulic structures of dams that provide the stability of the dam and downstream areas at the time of flood. A circular vertical spillway with various inlet forms is very effective when there is not enough space for the other spillway. Hydraulic flow in a vertical circular spillway is divided into three groups: free, orifice, and under pressure (submerged). In this research, the hydraulic flow characteristics of a Circular Vertical Spillway are investigated with the CFD model. Two-dimensional unsteady RANS equations were solved numerically using Finite Volume Method. The PISO scheme was applied for the velocity-pressure coupling. The mostly used two-equation turbulence models, k-ε and k-ω, were chosen to model Reynolds shear stress term. The power law scheme was used for the discretization of momentum, k, ε, and ω equations. The VOF method (geometrically reconstruction algorithm) was adopted for interface simulation. In this study, three types of computational grids (coarse, intermediate, and fine) were used to discriminate the simulation environment. In order to simulate the flow, the k-ε (Standard, RNG, Realizable) and k-ω (standard and SST) models were used. Also, in order to find the best wall function, two types, standard wall, and non-equilibrium wall function, were investigated. The laminar model did not produce satisfactory flow depth and velocity along the Morning-Glory spillway. The results of the most commonly used two-equation turbulence models (k-ε and k-ω) were identical. Furthermore, the standard wall function produced better results compared to the non-equilibrium wall function. Thus, for other simulations, the standard k-ε with the standard wall function was preferred. The comparison criterion in this study is also the trajectory profile of jet water. The results show that the fine computational grid, the input speed condition for the flow input boundary, and the output pressure for the boundaries that are in contact with the air provide the best possible results. Also, the standard wall function is chosen for the effect of the wall function, and the turbulent model k-ε (Standard) has the most consistent results with experimental results. When the jet gets closer to the end of the basin, the computational results increase with the numerical results of their differences. The mesh with 10602 nodes, turbulent model k-ε standard and the standard wall function, provide the best results for modeling the flow in a vertical circular Spillway. There was a good agreement between numerical and experimental results in the upper and lower nappe profiles. In the study of water level over crest and discharge, in low water levels, the results of numerical modeling are good agreement with the experimental, but with the increasing water level, the difference between the numerical and experimental discharge is more. In the study of the flow coefficient, by decreasing in P/R ratio, the difference between the numerical and experimental result increases.

Keywords: circular vertical, spillway, numerical model, boundary conditions

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Authors: Margarida Plana

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One of the most important energy challenge of the European policies is the transition to a Net Zero Energy Building (NZEB) model. A NZEB is a new concept of building that has the aim of reducing both the energy consumption and the carbon emissions to nearly zero of the course of a year. To achieve this nearly zero consumption, apart from being buildings with high efficiency levels, the energy consumed by the building has to be produced on-site. This paper is focused on presenting the results of the analysis developed on basis of real projects’ data in order to quantify the impact of end-users behavior. The analysis is focused on how the behavior of building’s occupants can vary the achievement of the energy savings targets and how they can be limited. The results obtained show that on this kind of project, with very high energy performance, is required to limit the end-users interaction with the system operation to be able to reach the targets fixed.

Keywords: end-users impacts, energy efficiency, energy savings, NZEB model

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Authors: Poonam Yadav, Dong Bok Lee

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Raman spectroscopy was used for characterization of multi-wall carbon nanotube (MWNT) and Polycarbonate/multi-wall carbon nanotube (PC/MWNT) based fibers with 0.55% and 0.75% of MWNT (PC/MWNT55 and PC/MWNT75). PC/MWNT55 and PC/MWNT75 fibers was prepared by melt spinning device using nanocomposites made by two different route, viz., solvent casting and melt extrusion. Fibers prepared from melt extruded nanocomposites showed smooth and uniform morphology as compared to solvent casting based nanocomposites. The Raman mapping confirmed that the melt extruded based nanocomposites had better dispersion of MWNT in Polycarbonate (PC) than solvent casting carbon nanotube.

Keywords: dispersion, melt extrusion, multi-wall carbon nanotube, mapping

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Authors: F. Fernandes, C. Poleto

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This paper aims at assessing the concentrations of heavy metals and the isotopic composition of lead ²¹⁰Pb in different fractions of sediment produced in the watershed that makes up the Mãe d'água dam and thus characterizing the distribution of metals along the sedimentary column and inferencing in the urbanization of the same process. Sample collection was carried out in June 2014; eight sediment cores were sampled in the lake of the dam. For extraction of the sediments core, a core sampler “Piston Core” was used. The trace metal concentrations were determined by conventional atomic absorption spectrophotometric methods. The samples were subjected to radiochemical analysis of ²¹⁰Po. ²¹⁰Pb activity was obtained by measuring ²¹⁰Po activity. The chronology was calculated using the constant rate of supply (CRS). ²¹⁰Pb is used to estimate the sedimentation rate.

Keywords: ²¹⁰Pb dating method, heavy metal, lakes urban, pollution history

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Authors: Yun-na Wu, Zhen Wang

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Due to the economic downturn and the deterioration of the living environment, the development of residential buildings as high energy consuming building is gradually changing from “extensive” to green building in China. So, the evaluation system of green building is continuously improved, but the current evaluation work has the following problems: (1) There are differences in the cost of the actual investment and the purchasing power of residents, also construction target of green residential building is single and lacks multi-objective performance development. (2) Green building evaluation lacks regional characteristics and cannot reflect the different regional residents demand. (3) In the process of determining the criteria weight, the experts’ judgment matrix is difficult to meet the requirement of consistency. Therefore, to solve those problems, questionnaires which are about the green residential building for Ningxia area are distributed, and the results of questionnaires can feedback the purchasing power of residents and the acceptance of the green building cost. Secondly, combined with the geographical features of Ningxia minority areas, the evaluation criteria system of green residential building is constructed. Finally, using the improved group AHP method and the grey clustering method, the criteria weight is determined, and a real case is evaluated, which is located in Xing Qing district, Ningxia. A conclusion can be obtained that the professional evaluation for this project and good social recognition is basically the same.

Keywords: evaluation, green residential building, grey clustering method, group AHP

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Authors: Samuel David Dunstan

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An elementary observation of a laminar cylindrical Poiseulle-Couette flow profile reveals no distinction in the parabolic streamwise profile from one without a cross-stream flow in whatever reference frame the observation is made. This is because the laminar flow is in solid-body rotation, and there is no intrinsic fluid rotation. Hence the main streamwise Poiseuille flow is unaffected. However, in turbulent (unsteady) cylindrical Poiseuille-Couette flow, the rotational reference frame must be considered, and any observation from an external inertial reference frame can give outright incorrect results. A common misconception in the study of fluid mechanics is the position of the observer does not matter. In this DNS (direct numerical simulation) study, firstly, turbulent flow in a pipe with axial rotation is established. Then in turbulent flow in the concentric pipe, with inner wall rotation, it is shown how the wall streak direction is oriented by the rotational reference frame. The Coriolis force here is not so fictitious after all!

Keywords: concentric pipe, rotational and inertial frames, frame invariance, wall streaks, flow orientation

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Authors: K. A. Sudjatmi, Endiah Puji Hastuti, Surip Widodo, Reinaldy Nazar

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Any pretensions to stop the production of TRIGA fuel elements by TRIGA reactor fuel elements manufacturer should be anticipated by the operating agency of TRIGA reactor to replace the cylinder type fuel element with plate type fuel element, that available on the market. This away was performed the calculation on U3Si2Al fuel with uranium enrichment of 19.75% and a load level of 2.96 gU/cm3. Maximum power that can be operated on free convection cooling mode at the BANDUNG TRIGA reactor fuel plate was 600 kW. This study has been conducted thermalhydraulic characteristic calculation model of the reactor core power 2MW. BANDUNG TRIGA reactor core fueled plate type is composed of 16 fuel elements, 4 control elements and one irradiation facility which is located right in the middle of the core. The reactor core is cooled using a pump which is already available with flow rate 900 gpm. Analysis on forced convection cooling mode with flow from the top down from 10%, 20%, 30% and so on up to a 100% rate of coolant flow. performed using the COOLOD-N2 code. The calculations result showed that the 2 MW power with inlet coolant temperature at 37 °C and cooling rate percentage of 50%, then the coolant temperature, maximum cladding and meat respectively 64.96 oC, 124.81 oC, and 125.08 oC, DNBR (departure from nucleate boiling ratio)=1.23 and OFIR (onset of flow instability ratio)=1:00. The results are expected to be used as a reference for determining the power and cooling rate level of the BANDUNG TRIGA reactor core plate types fueled.

Keywords: TRIGA, COOLOD-N2, plate type fuel element, force convection, thermal hydraulic characteristic

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Authors: Jianliang Xu, Zhenghua Dai, Zhongjie Shen, Haifeng Liu, Fuchen Wang

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In an entrained flow gasifier, the combustible components are converted into the gas phase, and the mineral content is converted into ash. Most of the ash particles or droplets are deposited on the refractory or membrane wall and form a slag layer that flows down to the quenching system. The captured particle reaction process and slag flow and phase transformation play an important role in gasifier performance and safe and stable operation. The reaction characteristic of captured char particles on the molten slag had been studied by applied a high-temperature stage microscope. The gasification process of captured chars with CO2 on the slag surface was observed and recorded, compared to the original char gasification. The particle size evolution, heat transfer process are discussed, and the gasification reaction index of the capture char particle are modeled. Molten slag layer promoted the char reactivity from the analysis of reaction index, Coupled with heat transfer analysis, shrinking particle model (SPM) was applied and modified to predict the gasification time at carbon conversion of 0.9, and results showed an agreement with the experimental data. A comprehensive model with gas-particle-slag flow and reaction models was used to model the different industry gasifier. The carbon conversion information in the spatial space and slag layer surface are investigated. The slag flow characteristic, such as slag velocity, molten slag thickness, slag temperature distribution on the membrane wall and refractory brick are discussed.

Keywords: char, slag, numerical simulation, gasification, wall reaction, membrane wall

Procedia PDF Downloads 279

Authors: Ik–Tae Im, H. M. Abdelmotalib, M. A. Youssef, S. B. Young

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In this study the flow characteristics and bed-to-wall heat transfer in a gas-solid conical fluidized bed combustor were investigated using both experimental and numerical methods. The computational fluid dynamic (CFD) simulations were carried out using a commercial software, Fluent V6.3. A two-fluid Eulerian-Eulerian model was applied in order to simulate the gas–solid flow and heat transfer in a conical sand-air bed with 30o con angle and 22 cm static bed height. Effect of different fluidizing number varying in the range of 1.5 - 2.3, drag models namely (Syamlal-O’Brien and Gidaspow), and friction viscosity on flow and bed-to-wall heat transfer were analyzed. Both bed pressure drop and heat transfer coefficient increased with increasing inlet gas velocity. The Gidaspow drag model showed a better agreement with experimental results than other drag model. The friction viscosity had no clear effect on both hydrodynamics and heat transfer.

Keywords: computational fluid dynamics, heat transfer coefficient, hydrodynamics, renewable energy

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Authors: Paula Marín, Mohammad Saffari, Alvaro de Gracia, Luisa F. Cabeza, Svetlana Ushak

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Climate control represents an important issue when referring to energy consumption of buildings and associated expenses, both in installation or operation periods. The climate control of a building relies on several factors. Among them, localization, orientation, architectural elements, sources of energy used, are considered. In order to study the thermal behaviour of a building set up, the present study proposes the use of energy simulation program Energy Plus. In recent years, energy simulation programs have become important tools for evaluation of thermal/energy performance of buildings and facilities. Besides, the need to find new forms of passive conditioning in buildings for energy saving is a critical component. The use of phase change materials (PCMs) for heat storage applications has grown in importance due to its high efficiency. Therefore, the climatic conditions of Northern Chile: high solar radiation and extreme temperature fluctuations ranging from -10°C to 30°C (Calama city), low index of cloudy days during the year are appropriate to take advantage of solar energy and use passive systems in buildings. Also, the extensive mining activities in northern Chile encourage the use of large numbers of containers to harbour workers during shifts. These containers are constructed with lightweight construction systems, requiring heating during night and cooling during day, increasing the HVAC electricity consumption. The use of PCM can improve thermal comfort and reduce the energy consumption. The objective of this study was to evaluate the thermal and energy performance of containers of 2.5×2.5×2.5 m3, located in four cities of Chile: Antofagasta, Calama, Santiago, and Concepción. Lightweight envelopes, typically used in these building prototypes, were evaluated considering a container without PCM inclusion as the reference building and another container with PCM-enhanced envelopes as a test case, both of which have a door and a window in the same wall, orientated in two directions: North and South. To see the thermal response of these containers in different seasons, the simulations were performed considering a period of one year. The results show that higher energy savings for the four cities studied are obtained when the distribution of door and window in the container is in the north direction because of higher solar radiation incidence. The comparison of HVAC consumption and energy savings in % for north direction of door and window are summarised. Simulation results show that in the city of Antofagasta 47% of heating energy could be saved and in the cities of Calama and Concepción the biggest savings in terms of cooling could be achieved since PCM reduces almost all the cooling demand. Currently, based on simulation results, four containers have been constructed and sized with the same structural characteristics carried out in simulations, that are, containers with/without PCM, with door and window in one wall. Two of these containers will be placed in Antofagasta and two containers in a copper mine near to Calama, all of them will be monitored for a period of one year. The simulation results will be validated with experimental measurements and will be reported in the future.

Keywords: energy saving, lightweight construction, PCM, simulation

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Authors: Zhongzhong Zeng, Zichen Liang

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In recent years, Beijing courtyards have been facing the problem of renewal and renovation, and the residents are faced with the problems of small house areas, large household sizes, old and dangerous houses, etc. Among the many renovation methods, the authors note two more common practices of using the front porch to expand the floor area and adding a loft. Residents and architects, however, did not give the ventilation performance of the significant interior consideration before beginning the remodeling. The aim of this article is to explore the good or negative impacts of both front porch and loft structures on the manner of interior ventilation in the courtyard. Ventilation, in turn, is crucial to the indoor environmental quality of a home. The major method utilized in this study is the comparative analysis method, in which the authors create four alternative house models with or without a front porch and an attic as two variables and examine internal ventilation using the CFD(Computational Fluid Dynamics) technique. The authors compare the indoor ventilation of four different architectural models with or without front porches and lofts as two variables. The results obtained from the analysis of the sectional airflow and the plane 1.5m height cloud are the existence of the loft, to a certain extent, disrupts the airflow organization of the building and makes the rear wall high windows of the building less effective. Occupying the front porch to become the area of the house has no significant effect on ventilation, but try not to occupy the front porch and add the loft at the same time in the building renovation. The findings of this study led to the following recommendations: strive to preserve the courtyard building's original architectural design and make adjustments to only the inappropriate elements or constructions. The ventilation in the loft portion is inadequate, and the inhabitants typically use the loft as a living area. This may lead to the building relying more on air conditioning in the summer, which would raise energy demand. The front porch serves as a transition place as well as a source of shade, weather protection, and inside ventilation. In conclusion, the examination of interior environments in upcoming studies should concentrate on cross-disciplinary, multi-angle, and multi-level research topics.

Keywords: Beijing courtyard renewal, CFD, indoor environment, ventilation analysis

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Authors: Jarwa Prasetya Sih Handoko

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The issue of energy crisis for big cities in Indonesia are issues raised in line with the development of the city is rapidly increasing. Various attempts were made by the government in overcoming problems of energy needs in Indonesia. In addition to the efforts of the government required the efforts made by the public to solve this problem. The concept of green building in the design of the building with efforts to use energy efficiently can be one of the efforts that can be applied to solve this problem. Jakarta is capital and the one of the major cities in Indonesia with high economic growth. This leads to increased demand for office space for the people. So that the construction of office buildings in big cities like Jakarta very numerous. Office building is one of the buildings that require large energy consumption. As a building that could potentially require huge amounts of energy, the design should consider the use of energy to help provide solutions to problems of energy crisis in Indonesia. The concept of energy efficient is one of the concepts addressed in an effort to use energy in buildings to save energy needs of the building operations. Therefore, it is necessary to have a study that explores the application of the concept of energy efficiency and conservation in office buildings in Jakarta. In this study using two (2) buildings case study that Sequis Center Building and Sampoerna Strategic Square. Both are office buildings in Jakarta have earned the Green Building Certificate of Green Building Council Indonesia (GBCI). The study used literature review methods to address issues raised earlier. Whether it's related to a literature review on the study of office buildings and green building. With this paper is expected to be obtained on the application of the concept of energy efficiency and conservation in office buildings that have earned recognition as a green building by GBCI. The result could be a reference to the architect in designing the next office buildings, especially related to the concept of energy use in buildings. From this study, it can be concluded that the concept of energy efficiency and conservation in the design of office buildings can be applied to its orientation, the openings, the use shade in buildings, vegetation and building material selection and efficient use of water. So that it can reduce energy requirements needed to meet the needs of the building user activity. So the concept of energy efficiency and conservation in office buildings can be one of the efforts to realize the Green Office Building. Recommendations from this study is that the design of office buildings should be able to apply the concept of energy utilization in the design office. This is to meet the energy needs of the office buildings in an effort to realize the Green Building.

Keywords: energy crisis, energy efficiency, energy conservation, green building, office building

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Authors: Tan Dexian Arthur, James Wei Ming Kwek, Ian Loh, Lee Tee Sin

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Statement of the Problem: Mucoceles most commonly affect the frontal sinus, which results from chronic obstruction of the sinus ostium or cystic dilatation of mucous glands with ductal obstruction. They are known to cause bony erosion of the sinus walls, which can lead to large defects. These defects were typically managed by obliteration or cranialization of the frontal sinus. Although short term outcomes of conservative management of significant posterior table defects from fractures are promising, there have been no studies on the long-term outcomes of large dehiscences in the posterior wall of the frontal sinus. Methodology & Findings : Computed Tomography (CT) Paranasal Sinuses images were analyzed and found complete spontaneous osteogenesis of a large dehiscent frontal sinus posterior wall, secondary to a large mucocele, 9 years from functional endoscopic sinus surgery with the defect managed conservatively. Conclusion & Significance: The dura is well known for its osteogenic properties. Prior studies have showed that dura could induce osteogenesis in cutaneous tissue in the absence of other central nervous system structures. It was also demonstrated that osteogenesis and chondrogenesis were possible in zygomatic fractures by transplanting neonatal dura grafts to the bony defects in rats. Extrapolating from these studies, the authors postulate that the presence of dura beneath the bony deformity of the posterior frontal sinus wall had likely initiated the osteogenesis and restored the bony defect in the patient. In our literature review, we did not find any reports of spontaneous osteogenesis of large frontal sinus defects. While our experience is incidental, it reinforces the osteogenetic potential of an intact dura and further highlights that selected large defects of the posterior wall of the frontal sinus can be conservatively managed.

Keywords: paranasal sinus mucocele, mucocele, osteogenesis, dehiscence

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Authors: Khaled R. Khater

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this paper is an extension to previously published two papers; all share the first part of their titles. The papers theme is soil-structure interaction in the ground of soil retaining structures. The secant pile wall is the concern, while the focus is its capping beam. The earlier papers suggested a technique to structurally analyze capping beam. It has been proved that; pile rigidity shares the capping beam rigidity to resist the wall deformations. The current paper explains how the beam-pile integration re-distributes the pile’s bending moment for the benefits of wall deformations. It is concluded that re-distribution of pile bending moment is completely different than the calculated by plain strain analysis, values, and distributions. The pile diameter, beam rigidity, pile spacing, and the 3D-analysis-effect individually or all together affect the pile bending moment. The Plaxis-2D and STAAD-Pro 3D are the used software’s. Throughout this study, three sand densities, various pile and beam rigidities, and three excavation depths, i.e., 3.0-m, 4.0-m and 5.0-m have been considered.

Keywords: bending moment, capping beam, numerical analysis, secant pile, sandy soil

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Authors: Azzam Alosaimi

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Different countries attempt to reduce energy demands and Greenhouse Gas (GHG) emissions to mitigate global warming potential. They set different building codes to regulate excessive building’s energy losses. Energy losses occur due to pressure difference between the indoor and outdoor environments, and thus, heat transfers from one region to another. One major sources of energy loss is known as building airtightness. Building airtightness is the fundamental feature of the building envelope that directly impacts infiltration. Most of international building codes require minimum performance for new construction to ensure acceptable airtightness. The execution of airtightness required standards has become more challenging in recent years due to a lack of expertise and equipment, making it costly and time-consuming. Hence, researchers have developed predictive models to predict buildings infiltration rates to meet building codes and to reduce energy and cost. This research applies a theoretical modeling approach using Matlab software to predict mean infiltration rate distributions and total heat loss of Saudi Arabia’s housing stock.

Keywords: infiltration rate, energy demands, heating loss, cooling loss, carbon emissions

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Authors: Maria Khan

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Framing good core Human Resource Management (HRM) functions like recruitment, selection, training and development, which if executed effectively, can become a strategic advantage for a company. HRM policies related to mid-level managers can depend on the type of top management. This may be due to the difference in perception of effective HRM policies of an expatriate and local leadership. This comparative case study assesses how local mid-level managers are managed in leading multinational telecom companies in Pakistan. Core HRM functions related to managers were analysed through field research based on semi-structured interviews with relevant Human Resource Managers. Results suggest that recruitment and selection practices are not too different and are in compliance with best HRM practices. However, there is a difference in the effective implementation of Training and Development policies. Changing global management trends and skill development dictate that MNCs continuously develop the local talent effectively for local and international success.

Keywords: recruitment, selection, training, development, core HRM, human resource management, subsidiary, international staffing, managers, MNC, expatriate

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Authors: S. Roman

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This qualitative study used semi-structured interviews with three Canadian educators to examine peace-based pedagogies used in varied teaching contexts and the degree to which the teaching strategies implemented were aligned with goals of peace-keeping, peace-making or peace-building in the classroom. In this research, the teachers’ peace-oriented pedagogy was influenced by various strands of peace education theory, and as such shaped their conceptualization of ‘peace’. The study’s result shows that when educators implemented government-mandated curriculum, they worked around it and/or added content that increased opportunities for democratic peacebuilding. In addition, all three teachers also strengthened their peace-oriented practice by incorporating conflict resolution skills in and outside the classroom to augment a common social-justice oriented goal for peace-making and peace-keeping and made various distinctions around the conditions necessary for peace-building.

Keywords: citizenship, peace-building education, peace-building curriculum, pedagogy

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Authors: Sandile Daniel Ngidi

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Masonry structures often crack due to different factors, which include differential movement of structures, thermal expansion, and seismic waves. Retrofitting is introduced to ensure that these cracks do not expand to a point of making the wall fail. Crack stitching is one of many repairing methods used to repair cracked masonry walls. It is done by stitching helical stainless steel reinforcement bars to reconnect and stabilize the wall. The basic element of this reinforcing system is the mechanical interlink between the helical stainless-steel bar and the grout, which makes it such a flexible and well-known masonry repair system. The objective of this review was to use previous experimental work done by different authors to check the efficiency and effectiveness of using the crack stitching technique to repair and stabilize masonry walls. The technique was found to be effective to rejuvenate the strength of a masonry structure to be stronger than initial strength. Different factors were investigated, which include economic features, sustainability, buildability, and suitability of this technique for application in developing communities.

Keywords: brickforce, crack-stitching, masonry concrete, reinforcement, wall panels

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Authors: Jenan Abu Qadourah

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The suitable surface areas for the ST and PV installation are determined based on incident solar irradiation on different surfaces, shading analysis and suitable architectural area for integration considering limitations due to the constructions, available surfaces area and use of the available surfaces for other purposes. The incident solar radiation on the building surfaces and the building solar exposure analysis of the location of Amman, Jordan, is performed with Autodesk Ecotect analysis 2011 simulation software. The building model geometry within the typical urban context is created in “SketchUp,” which is then imported into Ecotect. The hourly climatic data of Amman, Jordan selected are the same ones used for the building simulation in IDA ICE and Polysun simulation software.

Keywords: photovoltaic, solar thermal, solar incident, simulation, building façade, solar potential

Procedia PDF Downloads 113

Authors: Valeriya Tyo, Serikbolat Yessengabulov

Abstract:

Regions with extreme climate conditions such as Astana city require energy saving measures to increase the energy performance of buildings which are responsible for more than 40% of total energy consumption. Identification of optimal building geometry is one of the key factors to be considered. The architectural form of a building has the impact on space heating and cooling energy use, however, the interrelationship between the geometry and resultant energy use is not always readily apparent. This paper presents a comparative case study of two prototypical buildings with compact building shape to assess its impact on energy performance.

Keywords: building geometry, energy efficiency, heat gain, heat loss

Procedia PDF Downloads 476

Authors: Yasser A. Khalifa, Michael J. Tait, A. M. Asce, Wael W. El-Dakhakhni, M. Asce

Abstract:

The quasi-static resistance functions for orthogonal corrugated core sandwich panels were determined experimentally. According to the American and Canadian codes for blast resistant designs of buildings UFC 3-340-02, ASCE/SEI 59-11, and CSA/ S850-12 the dynamic behavior is related to the static behavior under uniform loading. The target was to design a lightweight, relatively cheap, and quick sandwich panel to be employed as a sacrificial cladding for important buildings. For that an available corrugated cold formed steel sheet profile in North America was used as a core for the sandwich panel, in addition to using a quick, relatively low cost fabrication technique in the construction process. Six orthogonal corrugated core sandwich panels were tested and the influence of core sheet gauge on the behavior of the sandwich panels was explored using two different gauges. Failure modes, yield forces, ultimate forces, and corresponding deformations were determined and discussed.

Keywords: cold formed steel, lightweight structure, sandwich panel, sacrificial cladding, uniform loading

Procedia PDF Downloads 468

Authors: Huei Chu Weng

Abstract:

This paper presents a study on the effect of second-order slip on forced convection through a long isoflux heated or cooled planar microchannel. The fully developed solutions of flow and thermal fields are analytically obtained on the basis of the second-order Maxwell-Burnett slip and local heat flux boundary conditions. Results reveal that when the average flow velocity increases or the wall heat flux amount decreases, the role of thermal creep becomes more insignificant, while the effect of second-order slip becomes larger. The second-order term in the Deissler slip boundary condition is found to contribute a positive velocity slip and then to lead to a lower pressure drop as well as a lower temperature rise for the heated-wall case or to a higher temperature rise for the cooled-wall case. These findings are contrary to predictions made by the Karniadakis slip model.

Keywords: microfluidics, forced convection, thermal creep, second-order boundary conditions

Procedia PDF Downloads 284

Authors: Hankun Lin, Yiqiang Xiao, Qiaosheng Zhan

Abstract:

Shading devices (SDs) are widely used in buildings in the hot-humid climate areas for reducing cooling energy consumption for interior temperature, as the result of reducing the solar radiation directly. Contrasting the surface temperature of materials of SDs to the glass on the building façade could give more analysis for the shading effect. On the other side, SDs are much more used as the independence system on building façade in hot-humid area. This typical construction could have some impacts on building ventilation as well. This paper discusses the outdoor SDs’ effects on the building thermal environment and ventilation, through a set of measurements on a 2-floors office building in Guangzhou, China, which install a dynamic aluminum SD-system around the façade on 2^nd-floor. The measurements recorded the in/outdoor temperature, relative humidity, velocity, and the surface temperature of the aluminum panel and the glaze. After that, a CFD simulation was conducted for deeper discussion of ventilation. In conclusion, this paper reveals the temperature differences on the different material of the façade, and finds that the velocity of indoor environment could be reduced by the outdoor SDs.

Keywords: outdoor shading devices, hot-humid area, temperature, ventilation, measurement, CFD

Procedia PDF Downloads 427

Authors: Abdulhakeem Yusuf, Yomi Monday Aiyesimi, Mohammed Jiya

Abstract:

The failure in an ordinary heat transfer fluid to meet up with today’s industrial cooling rate has resulted in the development of high thermal conductivity fluid which nanofluids belongs. In this work, the problem of unsteady one dimensional laminar flow of an incompressible fluid within a parallel wall is considered with one wall assumed to be wavy. The model is presented in its rectangular coordinate system and incorporates the effects of thermophoresis and Brownian motion. The local similarity solutions were also obtained which depends on Soret number, Dufour number, Biot number, Lewis number, and heat generation parameter. The analytical solution is obtained in a closed form via the Adomian decomposition method. It was found that the method has a good agreement with the numerical method, and it is also established that the heat generation parameter has to be kept low so that heat energy are easily evacuated from the system.

Keywords: Adomian decomposition method, Biot number, Dufour number, nanofluid

Procedia PDF Downloads 304

Authors: Sameer Ansari, Suhas Nitsure

Abstract:

Biomimicry has made a big move into the built environment by adapting nature's solutions to human designs and inventions. We can examine numerous aspects of the built environment right from generating energy, fed by rainwater and powered by sun to over all land use impacts. This paper discusses the potential of a man made building which will work for the welfare of humans and reduce the impact of the harmful environment on us which we ourselves created for us. Building services inspired by nature such as building walls from homeostasis in organisms, natural ventilation from termites, artificial aggregates from natural aggregates, solar panels from photosynthesis and building structure itself compared to tree as a cantilever. Environmental services such as using CO2 as a feedstock for construction related activities, using Ornilux glasses and  saving birds from collision with buildings, using prefabricated steel for fast building members- save time and also negligible waste as no formwork is used. Maglev inspired car elevators in building which is unique and giving all together new direction to technology.

Keywords: biomimicry, green technology, maglev car elevator, civil engineering

Procedia PDF Downloads 554