scholarly journals Performance of a Fly Ash Geopolymeric Based Binder with Calcium Hydroxide, Portland Cement and Metakaolin as Additives

2018 ◽  
Vol 12 (1) ◽  
pp. 167-186 ◽  
Author(s):  
M. Kheradmand ◽  
Z. Abdollahnejad ◽  
F. Pacheco-Torgal
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Portland Cement ◽  
Calcium Hydroxide ◽  
Circular Economy ◽  
Cost Efficiency ◽  
Efficient Solution ◽  
Mixed Design ◽  
Cost Efficient ◽  
The Cost

Background:Geopolymeric binders are especially indicated when reusing a wide diversity of wastes. This is an important feature, especially in the European context, in which a circular economy and future zero waste are targeted. Still, the cost of these materials, due to the use of high purity activators, prevents their commercialization as they are simply not competitive enough.Objective:The reduction in the amount of activators could be a cost-efficient solution if the associated decrease in the mechanical properties turned not to be excessive. This means that it is important to investigate the manner in which these additives can be used on their composition in order to compensate that mechanical reduction.Results and Conclusion:This paper discloses results concerning the mixed design of fly ash based geopolymeric mixtures using metakaolin, Portland cement (OPC) and calcium hydroxide as additives. Their influence on the mechanical properties, microstructure and cost-efficiency was studied. The results showed that the use of Portland cement as an additive leads to lower compressive strength. Results also show that geopolymers with different additives have different optimum Na2SiO3/NaOH ratios.

scholarly journals Cost efficiency of retrofit measures for typical masonry houses in Kosovo

2019 ◽  
Vol 10 (1) ◽  
pp. 87-91
Author(s):  
Egzon Bajraktari ◽  
Violeta Nushi ◽  
Manuela Almeida
Keyword(s):  
Air Pollution ◽  
Energy Efficiency ◽  
Energy Consumption ◽  
Cost Efficiency ◽  
Efficient Solution ◽  
Building Stock ◽  
Cost Efficient ◽  
The Cost ◽  
The University ◽  
Initial Results

A major challenge our society faces today is the energy consumption of buildings. Building stock is responsible for about 40% of energy consumption worldwide. The same applies to Kosovo, where a large number of houses are poorly weatherized and inefficient in terms of energy consumption. Most of the energy consumption in the household sector in Kosovo is dedicated to the needs for heating purposes. Furthermore, many of these houses use wood or coal for heating, releasing a lot of gases in the air and so contributing to an increased air pollution both indoors and outdoors. The Faculty of Civil Engineering and Architecture at the University of Prishtina “Hasan Prishtina” aims to address the issue of energy efficiency for these houses. Specifically, in this study we intend to evaluate various retrofit measures applicable in the country for typical masonry houses and identify the cost-efficient solution. This paper reports the initial results of the study and discusses related challenges.

scholarly journals Cost Analysis of a Novel Method for Ecological Compensation—A Study of the Translocation of Dead Wood

2021 ◽  
Vol 13 (11) ◽  
pp. 6075
Author(s):  
Ola Lindroos ◽  
Malin Söderlind ◽  
Joel Jensen ◽  
Joakim Hjältén
Keyword(s):  
Cost Efficiency ◽  
Dead Wood ◽  
Road Transportation ◽  
Ecological Value ◽  
Ecological Compensation ◽  
Work Time ◽  
Delivery Times ◽  
Novel Method ◽  
Cost Efficient ◽  
The Cost

Translocation of dead wood is a novel method for ecological compensation and restoration that could, potentially, provide a new important tool for biodiversity conservation. With this method, substrates that normally have long delivery times are instantly created in a compensation area, and ideally many of the associated dead wood dwelling organisms are translocated together with the substrates. However, to a large extent, there is a lack of knowledge about the cost efficiency of different methods of ecological compensation. Therefore, the costs for different parts of a translocation process and its dependency on some influencing factors were studied. The observed cost was 465 SEK per translocated log for the actual compensation measure, with an additional 349 SEK/log for work to enable evaluation of the translocation’s ecological results. Based on time studies, models were developed to predict required work time and costs for different transportation distances and load sizes. Those models indicated that short extraction and insertion distances for logs should be prioritized over road transportation distances to minimize costs. They also highlighted a trade-off between costs and time until a given ecological value is reached in the compensation area. The methodology used can contribute to more cost-efficient operations and, by doing so, increase the use of ecological compensation and the benefits from a given input.

Low Cement/High Fly Ash Concretes: Their Properties and Response to Chemical Admixtures

1987 ◽  
Vol 113 ◽  
Author(s):  
V. H. Dodson
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Calcium Hydroxide ◽  
Pozzolanic Reaction ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Fly Ashes ◽  
Chemical Admixtures ◽  
Reaction With Water

ABSTRACTIn practice, the amount of fly ash added to portland cement concrete varies depending upon the desired end properties of the concrete. Generally, when a given portland cement concrete is redesigned to include fly ash, between 10 and 50% of the cement is replaced by a volume of fly ash equal to that of the cement. Sometimes as much as twice the volume of the cement replaced, although 45.4 kg (100 lbs) of cement will only produce enough calcium hydroxide during its reaction with water to react with about 9 kg (20 lbs) of a typical fly ash. The combination of large amounts of certain fly ashes with small amounts of portland cement in concrete has been found to produce surprisingly high compressive strengths, which cannot be accounted for by the conventional “pozzolanic reaction”. Ratios of cement to fly ash as high as 1:15 by weight can produce compressive strengths of 20.7 MPa (3,000 psi) at I day and over 41.4 MPa (6,000 psi) at 28 days. Methods of identifying these “hyperactive” fly ashes along with some of the startling results, with and without chemical admixtures are described.

scholarly journals Cost efficiency of the Czech and Slovak banking sectors: an application of the data envelopment analysis

2016 ◽  
Author(s):  
Iveta Palecková
Keyword(s):  
Data Envelopment Analysis ◽  
Cost Efficiency ◽  
Commercial Banks ◽  
Banking Sector ◽  
Banking Industry ◽  
Returns To Scale ◽  
Data Envelopment ◽  
Cost Efficient ◽  
The Cost ◽  
Variable Returns To Scale

The aim of the paper is to estimate the cost efficiency of the Czech and Slovak commercial banks within the period 2010-2014. For empirical analysis the Data Envelopment Analysis input-oriented model with variable returns to scale is applied on the data of the commercial banks. The intermediation approach is adopted to define the inputs and outputs. The Czech commercial banks are more cost efficient than Slovak commercial banks. The development of average cost efficiency is similar in the Czech and Slovak banking industry. The most efficient Czech banks are Ceská sporitelna and Sberbank in the Czech banking sector, the most efficient Slovak bank is Privatbanka with 100% efficiency.

scholarly journals Global Prospects of the Cost-Efficiency of Broiler Welfare in Middle-Segment Production Systems

Animals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 473 ◽  
Author(s):  
Luuk S.M. Vissers ◽  
Ingrid C. de Jong ◽  
Peter L.M. van Horne ◽  
Helmut W. Saatkamp
Keyword(s):  
United States ◽  
The Netherlands ◽  
Animal Welfare ◽  
Cost Efficiency ◽  
Production Systems ◽  
Production Costs ◽  
Middle Segment ◽  
Efficient Manner ◽  
Cost Efficient ◽  
The Cost

In the 2000s, the idea of a so-called middle-segment arose in North-West Europe to address the criticism on intensive broiler production systems. Middle-segment systems being indoor housing of slower-growing broiler strains at a stocking density ≤38 kg/m2. Previous literature showed that Dutch middle-segment systems entail a relatively large gain in animal welfare at a relatively low increase in costs, i.e., have a high cost-efficiency. The question is to what extent these findings are applicable to other countries. Therefore, the aim of this study is to gain insight in the global prospects of middle-segment systems by exploring the cost-efficiency of these systems in other parts of the world. A set of representative countries, containing the Netherlands, United States and Brazil were selected. Cost-efficiency was defined as the ratio of the change in the level of animal welfare and the change in production costs. The level of animal welfare was measured by the Welfare Quality (WQ) index score. Data was collected from literature and consulting experts. Results show that in the Netherlands, United States and Brazil a change from conventional towards a middle-segment system improves animal welfare in a cost-efficient manner (the Netherlands 9.1, United States 24.2 and Brazil 12.1). Overall, it can be concluded that in general middle-segment production systems provide a considerable increase in animal welfare at a relatively small increase in production costs and therefore offer good prospects for a cost-efficient improvement of broiler welfare.

scholarly journals Cost-efficient inter-robot delivery for resource-constrained and interdependent multi-robot schedules

2019 ◽  
Vol 16 (1) ◽  
pp. 172988141982804 ◽  
Author(s):  
Yin Chen ◽  
Xinjun Mao ◽  
Shuo Yang ◽  
Qiuzhen Wang
Keyword(s):  
Cost Efficiency ◽  
Resource Constrained ◽  
Task Execution ◽  
Robot System ◽  
Sequential Execution ◽  
Constrained Environments ◽  
Cost Efficient ◽  
The Cost ◽  
Multi Robot

A multi-robot system in resource-constrained environments needs to obtain resources for task execution. Typically, resources can be fetched from fixed stations, which, however, can be costly and even impossible when fixed stations are unavailable, depleted or distant from task execution locations. We present a method that allows robots to acquire urgently required resources from those robots with superfluous residual resources, by conducting rendezvouses with these robots. We consider a scenario where tasks are organised into a schedule on each robot for sequential execution, with cross-schedule dependencies for inter-robot collaboration. We design an algorithm to systematically generate such rendezvouses for entire multi-robot system to increase the proportion of tasks whose resource demands are satisfied. We also design an algorithm that periodically reallocates tasks among robots to improve the cost-efficiency of schedules. Our experiment shows the synergetic effectiveness of both algorithms, when fixed stations are unavailable and all resources are fetched through inter-robot delivery. We also investigate the effectiveness of inter-robot delivery in scenarios where fixed stations are existent but distant from the locations of tasks.

National Cost Efficiency of Supported Employees With Intellectual Disabilities: 2002 to 2007

2010 ◽  
Vol 115 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Robert E. Cimera
Keyword(s):  
United States ◽  
Intellectual Disabilities ◽  
Vocational Rehabilitation ◽  
Cost Efficiency ◽  
The United States ◽  
Considerable Variability ◽  
United State ◽  
Cost Efficient ◽  
The Cost

Abstract The cost efficiency of supported employees with intellectual disabilities who were served by vocational rehabilitation agencies throughout the United State from 2002 to 2007 was explored. Findings indicate that, on average, supported employees with intellectual disabilities were cost-efficient from the taxpayers' perspective regardless of whether they had secondary disabilities. In addition, no changes in cost efficiency were found during the period investigated. The data, however, did demonstrate considerable variability in cost efficiency throughout the United States and its territories.

Mechanical Properties of Class C High Volume Fly Ash Concrete with Lime Water as Mixing Water

2014 ◽  
Vol 660 ◽  
pp. 312-316
Author(s):  
Mochamad Solikin ◽  
Budi Setiawan
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Flexural Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
High Volume ◽  
Fly Ash Concrete ◽  
Lime Water ◽  
High Volume Fly Ash ◽  
Mixing Water

This paper reports an investigation on mechanical properties of high volume fly ash (HVFA) concrete produced using different types of mixing water i.e. tap water and saturated lime water. The mechanical properties of ordinary Portland cement concrete are also investigated as control tests. The concrete were tested for their compressive strength, flexural strength and splitting tensile strength at the curing ages of 56 days. The results showed that strength development of high volume fly ash concrete up to 56 days is lower than ordinary portal cement. In addition, the flexural strength and splitting strength of concrete are lower than ordinary Portland cement. Moreover, the use of saturated lime water as mixing water reduces the mechanical properties of class C high volume fly ash concrete.

Microstructure and Mechanical Properties of Cement/Fly Ash/Natural Rubber Composites

2017 ◽  
Vol 866 ◽  
pp. 195-198
Author(s):  
Rakchanok Promudom ◽  
Suparut Narksitipan ◽  
Nittaya Jaitanong
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Portland Cement ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Physical And Mechanical Properties ◽  
Ammonia Solution ◽  
Rubber Latex ◽  
Water To Cement Ratio ◽  
Natural Rubber Composites

The physical and mechanical properties of Portland cement (PC) - natural rubber latex (NRL) - fly ash (FA) composites have been investigated. The latex per cement ratios that use in this experiment are 0, 5, 7.5 and 10% by weight of cement. Portland cement (PC) was partially replaced with fly ash 0-40% by weight of binder. Water to cement ratio were used in range of 0.305-0.385 (by weight not include water in latex). Nonionic surfactant was added in cement before mixed with natural rubber latex. In addition, to provide latex from natural rubber latex, the ammonia solution is added into natural rubber. The specimens were packing into an iron mold which sample size of 4x4x16 cm3. Moreover, the PC-NRL-FA composites were cured in water for 7 and 28 days at room temperature before measurement. Then, mechanical properties (flexural strength) and microstructure were studied.

scholarly journals Analysis of Circular Development and Investment Possibilities (Transport, Energy and Building) Related to International Sports Event Planning

2017 ◽  
Vol 5 (1) ◽  
pp. 58-72 ◽  
Author(s):  
Bálint Horváth ◽  
Csaba Fogarassy
Keyword(s):  
Development Strategy ◽  
Circular Economy ◽  
Ghg Emissions ◽  
Low Carbon ◽  
Sports Events ◽  
Electric Scooter ◽  
Traffic Systems ◽  
Cost Efficient ◽  
Economic Perspectives ◽  
The Cost

Abstract This study investigates the possibilities of various development areas (transport, energy, building) to make the cost-efficient realisation of high-profile investments, and organising and holding international sports events possible. Using a case study, the paper introduces development routes based on the evaluation of environmental and economic perspectives. The current research introduces the investment characteristics based on the development of the Hungarian building, energy and transport sectors for the 2017-2030 period. The main criterion is the integration of ‘circular economy’. For sectors which operate with high material and energy consumption, the consideration of circular economy principles may prove to be important for sustainable development. Through planning highvolume sports and worldwide events, the usual development strategy for traffic systems focuses on public transport and rentable vehicles (f. e. electric scooter, or bicycle) which can decrease CO2 emissions via modern technological solutions. Regarding the buildings, sports arenas and related facilities, besides the existing low-carbon solutions, the functions of buildings must be expanded and their usage prolonged. The management of waste left after the life cycle is expended has to be pre-planned. These are the options for making the sector’s GHG emissions decrease apart from circular tenders, which can be further combined with SMART energetic solutions.

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