269 research outputs found
A novel lightweight cement composite incorporating micro-sized silica aerogel / Syed Nasir Shah
No full textLightweight cement composite (LCC) has gained more interest and is increasingly
explored by researchers due to its many advantageous properties. Silica aerogel (SA), a
synthetic ultralightweight material with a nano-porous structure and remarkable
insulation properties, makes it a potential option to be incorporated in LCC. LCC
incorporating SA (SA-LCC) would be an ideal insulating building material and could
promote energy efficiency in buildings since the building sector consumes about 30-40%
of global energy consumption. However, there are some challenges when it comes to
incorporating SA into LCC. One of the difficulties is mixing SA with cement composite
due to its ultra-lightweight and hydrophobic nature. Thus, this research aims to develop
a chemical treatment for SA to ease its mixing and assess the influence of micro-sized SA
on the properties of LCC. Therefore, a detailed study was conducted on both untreated
and treated SA-LCC. The study was divided into 3 phases; where phase 1 focuses on
developing chemical treatment for SA, characterizing untreated and treated SA, and
evaluating the effect of different content of untreated/treated SA (20-80% of sand
replacement) on the basic properties of LCC. The results of phase 1 revealed that the
treated SA became temporarily hydrophilic and eased the mixing. In addition, the
chemical treatment did not affect the pore structure, particle size distribution, chemical
bonds, and crystallographic structure of SA. A significant reduction in the oven-dry
density (up to 50%) and compressive strength (up to 80%) of SA-LCC was observed,
while the porosity was increased (up to 260%). Phase 2 emphasizes the insulating
properties, dimensional stability, durability performance, and microstructure
characteristics of SA-LCC. Despite the increase in water absorption (140/290%) and
decrease in water resistance (11/19%), the increase in porosity of LCC due to
incorporation of untreated/treated SA improved the insulating properties. The noise reduction coefficient (NRC) improved up to 15%, whereas the thermal conductivity was
improved up to 80%. Despite the beneficial insulating properties, the limitations of the
SA-LCC include the higher shrinkage (10 times) and lower resistance to elevated
temperatures, in addition to increased water absorption. Nevertheless, in overall, LCC
with a low oven-dry density of about 1190 kg/m3 and adequate compressive strength (6.38
MPa) can be produced by incorporating treated SA, which has a low thermal conductivity
(0.220 W/m.K) and good NRC (0.261). Therefore, in phase 3, in view of the observed
limitations of the SA-LCC, a scaled lightweight sandwich wall panel (SWP) was
introduced, which utilized calcium silicate board (CSB) as the skin. This is intended for
wall application to suit the benefits of the SA-LCC. The practical application of treated
SA-LCC as core for SWP shows that non-load bearing SWP can be produced with treated
SA-LCC and 6 mm CSB as the skin with unit weight, compressive, and flexural strength
of 1570 kg/m3, 2.4 MPa, and 4.7 MPa, respectively. The SWP also has good impact load
resistance (70 J) and direct flame resistance. Furthermore, the SWP has satisfactory
insulating properties with NRC and thermal conductivity of 0.259 and 0.561 W/m.K,
respectively
Algebraic Representation of Social Capital Matrix
No full textThis paper proposes a mathematical model based on a Boolean algebra involving a 4×4 social capital matrix [Shah (2008)], that emerges through interaction within and across individuals, communities, institutions and state. The framework provides a coding system for the existence or otherwise of various categories of social interaction. The model illustrates that social interaction can be neatly described in a format that facilitates the interpretation of social intra- and interactions among the four types of players in generating economic activity.Social Capital (Matrix), Linear Space, Interactive Systems, Boolean Algebra
Algebraic Representation of Social Capital Matrix
No full textThis paper proposes a mathematical model based on a Boolean algebra involving a 44 social capital matrix [Shah (2008)], that emerges through interaction within and across individuals, communities, institutions and state. The framework provides a coding system for the existence or otherwise of various categories of social interaction. The model illustrates that social interaction can be neatly described in a format that facilitates the interpretation of social intra- and interactions among the four types of players in generating economic activity.Social Capital (Matrix), Linear Space, Interactive Systems, Boolean Algebra
Analysis of Machine Learning Based Imputation of Missing Data
No full textData analysis and classification can be affected by the availability of missing data
in datasets. To deal with missing data, either deletion-based or imputation-based
methods are used that results in the reduction of data records or wrong predicted
value imputed by means/median respectively. A significant improvement can be
done if missing values are imputed more accurately with less computation cost.
In this work, a flow for analysis of machine learning-based algorithms for
missing data imputation is proposed. The K-nearest neighbors (KNN) and
Sequential KNN (SKNN) algorithms are used to impute missing values in
datasets using machine learning. Missing values handled using statistical
deletion approach (List-wise Deletion) and ML-based imputation methods (KNN
and SKNN) is then tested and compared using different ML classifiers (Support
Vector Machine and Decision Tree) to evaluate effectiveness of imputed data.
The used algorithms are compared in terms of accuracy, and results yielded that
the ML-based imputation method (SKNN) outperforms LD-based approach and
KNN method in terms of effectiveness of handling missing data in almost every dataset with both classification algorithms (SVM and DT)
Hydraulic simulations to evaluate and predict design and operation of the Chashma Right Bank Canal
No full textIrrigation systems / Irrigation canals / Flow control / Velocity / Canal regulation techniques / Hydraulics / Simulation models / Design / Operations / Crop-based irrigation / Distributary canals / Water delivery / Policy / Protective irrigation / Water allocation / Water requirements / Sedimentation / Water distribution / Equity / Water conveyance / Pakistan / Chashma Right Bank Canal
Organizational learning capability and organizational innovativeness: the mediating effect of transformational leadership style of academic managers / Shahri Abu Seman and Syed Jamal Abdul Nasir Syed Mohamad
No full textThe role of organizational learning in enhancing firm’s innovativeness has become important to secure a sustainable competitive edge. This study attempts to explore this relationship by introducing a transformational leadership style as a mediator. The data were collected from 220 participants belonging to private higher education institutions in Malaysia through survey research using the structured interview schedule. The findings confirm organizational learning to be an important factor in promoting creativity in innovative organization. Transformational leadership Managers with learning ability improves their leadership skill and understanding to accumulate knowledge and experience to use it productively in challenging and competitive environment. This accumulated knowledge can further be utilized to enhance ability to anticipate the future and respond to customers’ demands through products based on their innovation capability. The implications of the results for academics and practitioners are discussed
Fertility transition in Pakistan: neglected dimensions and policy implications
No full textThis research addresses some of the neglected non-program dimensions related to stagnant fertility transition in Pakistan. Previous research identified a range of factors influencing fertility in Pakistan, particularly the effect of distortions in reported ages, fertility inhibiting variables, timing of first marriage and first birth, and birth intervals. The literature provides evidence that there is no systematic analysis of these dimensions particularly at the regional levels. This research addresses these dimensions by evaluating the fertility and reproductive health data in particular using the cross-sectional data from the 1990 and 2006 Pakistan Demographic and Health Survey, and 2000-01 Pakistan Reproductive Health and Family Planning Survey.Based on the application of relevant demographic and statistical techniques, the study demonstrates evidence of clear discrepancies in age reporting among married females across the seven geographic regions. This had influence on the estimated marital fertility rates which tend to be significantly higher when the reporting effects were adjusted. The analysis of fertility inhibiting factors reveals that timing of marriage and contraceptive use are crucial determinants associated with fertility reduction in Pakistan. By far, the strongest factor driving increase at first marriage in Pakistan is the level of female education which tends to vary significantly across different geographic regions. The analysis of the duration between marriage and first conception shows rather unexpected complex hazard functions with two peaks suggesting the behaviour of two different groups of women: those adhering to the traditional pattern in which conception take place soon after marriage; and those who postpone conception after marriage. Punjab, Baluchistan and urban regions are ahead of the fertility transition at the national level, confirming the effect of longer birth intervals. Based on the analysis of the proximate determinants framework, it can be concluded that Pakistan has entered the early third phase of the fertility transition. Urban Punjab and Baluchistan have also showed convergence to the third phase of the fertility transition. Breastfeeding and amenorrhea have emerged as significant determinants of birth interval duration.The results of this study highlight various areas for programme intervention and policy development. There is a dire need for a policy to improve the levels of female literacy and education especially in poorly developed regions which are in the second phase of fertility transition. A cost-effective intervention would be using mass media, for example radio broadcasting as the medium to disseminate reproductive health and family planning information. Pakistan needs specific policy interventions aimed at empowering girls with education for delaying marriage and encouraging contraceptive use. In formal education programmes, the syllabus should include the introduction to contraception, sexual health education as well as information on sexually transmitted diseases
The enhancers and barriers to the development of Malaysian lifelong learning communities: a case study in Shah Alam / Mohd Rashidee Alwi … [et.al.]
No full textThis paper discusses the factors that facilitate and hinder communities in lifelong learning activities in Shah Alam city. Using qualitative approach 16 informants
from various backgrounds were interviewed to identify the meaning of lifelong learning, learning opportunities, and enhancers and barriers to the development
of lifelong learning in Shah Alam. The study found that lifelong learning was defined as a continuous learning process that included formal, non-formal and
informal education. The informants also revealed that there were very wide learning opportunities provided by various parties in Shah Alam
Women’s Autonomy and Happiness: The Case of Pakistan
No full textIt is generally believed that “autonomy” brings happiness and satisfaction in women’s lives. In this study we examine whether or not the established autonomy indicators are a source of “happiness” for Pakistani women. By using the nationally representative data, only two indicators, i.e., “women’s education” and “decisionmaking authority”, prove to be important factors in finding “very happy” status in women’s life. Additionally, “possession of assets” also proves to be an important factor in providing the “very happy” status in a women’s life. However, the “possession and utilisation of assets” and “going alone outside the house” are not important indicators of a “very happy” status in women’s life in Pakistan and “Labour force participation” is indicative of unhappiness. The results of this study show that not all established indicators of autonomy bring about happiness in the lives of Pakistani women. This is because Pakistani society differs from other societies, in particular the western society, and hence the concept of “autonomy” in bringing about “happiness” in the lives of Pakistani women yields effects different from those in other societies. Thus, there is a need to focus on the advocacy of only those autonomy variables which lead to happiness in a woman’s life, which is the end-goal for women, who form a vital part of the society.Women
Comments on “Estimating Income Variances by Probability Sampling: A Case Study by Shah and Aleem”
No full textIn this article, we wish to write comments on recently published article “Shah, A.A. and Aleem, M. (2010). Estimating income variances by probability sampling: a case study. Pakistan Journal of Commerce and Social Sciences, 4(2), 194-201”, which suggest improvement as well as criticism on the paper and also contribute effectively towardsjournal repute and ranking
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