Water absorption and salt attack resistance of coal ash brick made of different percentage of foam content

Coal ash which constitute of fly ash and bottom ash were proved to be used as main component in brick production. However, published work on the coal ash brick with addition of foam in order to produce lightweight brick is still lacking. This thesis reports the effect of variation in foam content in coal ash brick on the density, water absorption and salt attack resistance. Comparison of those parameters was made between the coal ash bricks and conventional brick. The coal ash brick mixes were formulated using industrial by-product, ground granulated blastfurnace slag (GGBS) which is activated with an alkaline (hydrated lime or Portland cement) combined with coal ash from coal-fired thermal power plant. The blended binder comprising of hydrated lime (HL) – GGBS and Portland cement (PC) –GGBS were used to stabilize the coal ash brick. Foam was used to produce lightweight brick. The percentage of foam added to the brick mixes are 25%, 50% and 75%. A total of sixty (60) brick specimen subjected to ten (10) series of mix proportion were cast and put in air curing condition for at least 28 days before testing. The density measurement in accordance with AS/NZS 4456.8, water absorption test in accordance with BS EN 772-21 and salt attack resistance in accordance with AS/NZS 4456.10 were evaluated on the brick specimens. The results indicated that the density of coal ash brick decreases with the increase in foam content. Also for bricks composed of both blended binder, the water absorption were directly proportional to the amount of foam. Thus, the water absorption of foam brick increases with the reduction in density. Higher foam content leads increase of pores and capillaries in brick structure, therefore the brick become weaker to resist on salt attack. XRD pattern of formed brick with 75% of foam addition on HL-GGBS coal ash brick portrays ettringite formation were attributed to disruption of brick structure. The use of coal ash with HL–GGBS and PC-GGBS combination as binder agent has been observed to be lightweight, low in water absorption, and advantageous in protection to salt attack compare to the conventional brick. The optimum proportion respected to the foam content is 50% in balance condition with approximately 1-2% of mass loss due to salt attack, 12-13% of water absorption and density significantly reduced to 1600kg/m3 . Keywords – fly ash; bottom ash; hydrated lime; Portland cement; ground granulated blastfurnace slag (GGBS); foam; brick; density; water absorption; salt attack resistanc

The issue is... the occupational therapist’s role in addressing the silent sequelae associated with cancer-related cognitive dysfunction among survivors of cancer

The National Comprehensive Cancer Network identified occupational therapy as a first line of intervention for the treatment of cancer-related cognitive dysfunction (CRCD) (National Comprehensive Cancer Network [NCCN], 2016). Thus, occupational therapists have an opportunity to develop interventions that facilitate participation in meaningful occupations for survivors of cancer living with CRCD. In this article, we argue for occupational therapists to create occupation- and evidence-based, client-centered interventions for survivors of cancer with CRCD that address the multidimensional presentation of CRCD. One survivor’s story illustrates the affect of CRCD on occupational performance and the features to consider when developing interventions to meet the unique needs of survivors of cancer with CRCD. We recommend that interventions can be provided through self-paced home programming, community settings, or delivered through modes such as tele-rehabilitation to reach the growing population of survivors of cancer

Utilizing Computer-Assisted Vocabulary Learning Tools in English Language Teaching: Examining In-Service Teachers' Perceptions of the Usability of Digital Flashcards

This study explores five in-service teachers' perceptions with regards to the technical and pedagogical usability of digital flashcards in English language teaching. All the teachers were enrolled in a one-year Masters of Art in English Language Teaching program at Coventry University and had previous teaching experience ranging from elementary to university level. The study adopted a quan?QUAL mixed-method research design, combining elements of surveys and case studies, to examine the factors that affected the teachers' perceptions in addition to how they view three specific websites: Cram, Quizlet, and StudyStack. Participants explored these websites and created sets of flashcards in a computer lab, then completed a survey and participated in a focus group interview. Findings suggest that although the teachers were willing to integrate digital flashcards in their future teaching, it is dependent on several factors, including: learners' age, the quality of graphics in the websites, and the teachers' prior experience as students on their MA program. Nonetheless, the “wow” factor seemed to influence their perceptions of the usability of these websites, which can either be extreme positive or negative initial reactions as a result of the websites' presentational scheme.</jats:p

Improving thermal conductivity of fired clay brick using sawdust waste

The demand for energy efficient design and construction has become progressively important with the growing energy costs and increasing awareness on the effects of global warming. Global warming causes a higher temperature of the surrounding, which will give significant effect to the energy consumption in commercial and residential building. Therefore, this study aims to investigate the possibility of incorporating sawdust as an additive material to improve thermal insulation properties of clay brick through lowering its thermal conductivity value. This study uses three types of soils with the proportion of clay soil (80%), laterite soil (10%) and grey soil (10%). The percentages of sawdust waste used as an additive are 2.5%, 5% and 7.5% by weight. The laboratory works performed involve the geotechnical gradation, physical, mechanical, chemical composition and thermal conductivity of fired clay brick. There are two types of brick that were produced in this study, which are control brick (CB) and sawdust brick (SB). The results show that the thermal conductivity of fire clay brick improves with the increasing percentage of waste material. Therefore, in this study, it appears that the brick incorporated with 5% of the sawdust waste is the optimum value that can achieve 7.5 MPa of compressive strength, 23.01.56% of water absorption and 0.384 W/m˚C of thermal conductivity. Thus, 5% of sawdust waste is chosen as the optimum percentage that yields better fired clay brick. This study reveals that the sawdust is a potential waste material that can be used to improve the thermal property and as a sustainable construction material

The size of maximal systems of brick islands

For integers $m_1,...,m_d>0$ and a cuboid $M=[0,m_1]\times ... \times [0,m_d]\subset \mathbb{R}^d$, a brick of $M$ is a closed cuboid whose vertices have integer coordinates. A set $H$ of bricks in $M$ is a system of brick islands if for each pair of bricks in $H$ one contains the other or they are disjoint. Such a system is maximal if it cannot be extended to a larger system of brick islands. Extending the work of Lengv\'{a}rszky, we show that the minimum size of a maximal system of brick islands in $M$ is $\sum_{i=1}^d m_i - (d-1)$. Also, in a cube $C=[0,m]^d$ we define the corresponding notion of a system of cubic islands, and prove bounds on the sizes of maximal systems of cubic islands.Comment: 12 page

Teaching Library History: Engaging the Academic Community

The author provides an overview of an upper-level undergraduate course on library history he has created and taught at a small Bible college. He reviews the lessons learned from the experience as well as the opportunities this course provided for information literacy instruction