L. Lau, T. Siu, J. Fan, L.Y.C. Siu and E. Newton
Two groups of fabric samples: six 100% cotton twill fabrics with different level of wrinklefree treatment, and six 100% cotton twill fabrics without wrinkle-free treatment were…
Abstract
Two groups of fabric samples: six 100% cotton twill fabrics with different level of wrinklefree treatment, and six 100% cotton twill fabrics without wrinkle-free treatment were experimentally studied. These fabrics were tested in terms of nitrogen content, swelling index (water retention), tear strength and dynamic water absorption rate. The nitrogen content was considered as a probably better indicator of the level of wrinkle-free treatment than the swelling index (water retention) commonly used in the industry. In this work, the relationship between the nitrogen content and swelling index (water retention) were studied. The effects of nitrogen content and swelling index (water retention) on the tear strength and the dynamic water absorbency were investigated
The results showed that
The swelling index (water retention) has a strong linear relationship with the total nitrogen content in the fabric. The higher nitrogen content, the lower the swelling index (water retention).
The fabric tear strength is highly correlated with the total nitrogen content or the swelling index (water retention). High nitrogen content or low swelling index (water retention), which may be resulted from the wrinkle-free treatment, causes low tear strength
High nitrogen content or low swelling index (water retention) reduces the water absorption rate of the fabric and increases the contact angle when the water drop is in initial contact of the fabric.
In general, the study showed that swelling index (water retention), a simple test commonly used in the industry, is as good a parameter as the nitrogen content, which is difficult to measure, for evaluating the level of wrinkle-free treatment. Wrinkle-free treatment can generally reduce the tear strength and the dynamic water absorption rate. The former is a property important to fabric durability and the latter is a property important to clothing comfort.
Senthil Kumar B., Anita Rachel D. and Sentil Kumar C.B.
Eri silk fiber has superior thermal insulation behavior, better softness than cotton fiber. However, Eri silk’s use in the commercial arena has not yet taken off. The purpose of…
Abstract
Purpose
Eri silk fiber has superior thermal insulation behavior, better softness than cotton fiber. However, Eri silk’s use in the commercial arena has not yet taken off. The purpose of the study is to explore the comfort properties of the fabric, which enhances the commercial acceptance of Eri silk clothing.
Design/methodology/approach
In this investigation, three different single knit Eri silk structures were produced with different loop lengths and yarn counts to analyze the influence of process variables on low-stress mechanical properties. To execute the research work, Eri silk spun yarn of three different linear densities (15 tex, 20 tex, 25 tex) were chosen. Three different knitted structures were produced, such as single jersey, popcorn and cellular blister, and two different loop lengths were also selected.
Findings
The cellular blister structure has shown appreciable low-stress properties next highest position was attained by the popcorn structure. Yarn fineness and loop length were significant with most of the low-stress properties.
Research limitations/implications
The findings of this research will contribute to a greater awareness of Eri silk knitted fabric and its process parameters in relation to its commercial utility.
Originality/value
This study was conducted to explore the influence of knit structure, loop length and yarn count on the low-stress properties of Eri silk-based thermal clothing.
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Shiu Hong Choi and James Siu Lung Lee
Minimising makespan aims to achieve high utilisation of equipment and resources by getting all jobs out quickly. This is an important scheduling criterion, especially for…
Abstract
Minimising makespan aims to achieve high utilisation of equipment and resources by getting all jobs out quickly. This is an important scheduling criterion, especially for automated systems, because of the high investment cost. The problem, however, becomes complex when many parts and machines are involved. This is because different parts may require different numbers of operations, and there are many possible schedules. For small problems, a mathematical programming model for minimising makespan is formulated. For large problems, a sequencing algorithm based on decomposition and pairwise comparison is proposed. The idea of “total overlapping time” in the sequencing algorithm is introduced to determine the solution of each sub‐schedule. It maximises the number of jobs working at different machines at the same time, while satisfying the parts’ operation precedence and machine constraints. The differences between this method and the traditional graphical method are discussed. The sequencing algorithm significantly reduces the number of schedules for consideration and hence, the computational power required.
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The paper includes characterizing Ramsey policy in a cash-in-advance monetary model, under flexible and sticky prices, and with different fiscal instruments.
Abstract
Purpose
The paper includes characterizing Ramsey policy in a cash-in-advance monetary model, under flexible and sticky prices, and with different fiscal instruments.
Design/methodology/approach
The paper analytically and numerically characterizes the dynamic properties of Ramsey allocations. The author computes dynamics by solving second-order approximations to the Ramsey planner’s policy functions around a non-stochastic Ramsey steady state.
Findings
The Friedman rule is not mainly optimal in a cash-in-advance model with distorting taxes. The Ramsey-optimal policy with both taxes on income and consumption calls for a high inflation rate that is extremely volatile, despite the fact that changing prices is costly.
Practical implications
The optimality of zero nominal interest rate under flexible prices in monetary models is not mainly the case and quite depends on the preferences. The optimality of a zero inflation rate under sticky prices also very much depends on the assumed set of fiscal instruments.
Originality/value
The non-optimality of the Friedman rule under flexible prices is quite new. Moreover, studying the optimal fiscal and monetary policy in a New Keynesian model with a rich set of fiscal instruments is also quite original.
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Robert J. Elliott, Tak Kuen Siu and Alex Badescu
The purpose of this paper is to consider a discrete‐time, Markov, regime‐switching, affine term‐structure model for valuing bonds and other interest rate securities. The proposed…
Abstract
Purpose
The purpose of this paper is to consider a discrete‐time, Markov, regime‐switching, affine term‐structure model for valuing bonds and other interest rate securities. The proposed model incorporates the impact of structural changes in (macro)‐economic conditions on interest‐rate dynamics. The market in the proposed model is, in general, incomplete. A modified version of the Esscher transform, namely, a double Esscher transform, is used to specify a price kernel so that both market and economic risks are taken into account.
Design/methodology/approach
The market in the proposed model is, in general, incomplete. A modified version of the Esscher transform, namely, a double Esscher transform, is used to specify a price kernel so that both market and economic risks are taken into account.
Findings
The authors derive a simple way to give exponential affine forms of bond prices using backward induction. The authors also consider a continuous‐time extension of the model and derive exponential affine forms of bond prices using the concept of stochastic flows.
Originality/value
The methods and results presented in the paper are new.
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Noel Scott, Brent Moyle, Ana Cláudia Campos, Liubov Skavronskaya and Biqiang Liu
Frances Mary D’Andrea and Yue-Ting Siu
For students who are blind or visually impaired, technology enables greater access to the educational curriculum, immediate and independent access to information, and full…
Abstract
For students who are blind or visually impaired, technology enables greater access to the educational curriculum, immediate and independent access to information, and full participation in community and citizenship. This chapter reviews research on technology use by students with visual impairments, and highlights effective practices, promising developments, and ongoing challenges. The authors discuss the implications of these advancements on policy, instruction, professional development, and future research.