94 research outputs found
Properties of close-to-convex functions and special functions / Jonathan Aaron Azlan Mosiun
No full textLet S be the class of functions of the form f(z) = z + 1P n=2 anzn that are univalent and analytic in the unit disc U = fz 2 C : jzj < 1g. Study on functions derived via geometric properties such as S_, C and K, which are subclasses of S, has been ongoing for many
decades and has been done extensively and exhaustively. Among the many subclasses
of K, Sakaguchi introduced the class of starlike functions with respect to symmetric
point, denoted by S_
s . Since its introduction in 1959, many authors have introduced
generalizations of S_
s or classes resembling it. Inspired by this, Gao & Zhou introduced
another subclass of K which was denoted as Ks which was further generalized by Wang,
Gao, & Yuan. Following their inspirations, this dissertation introduces a subclass of
close-to-convex functions, denoted by Kk;N
s , where k;N 2 N, that combines the concepts
of S_ s and Ks and investigates them for their properties which include, but not limited to,
coefficient estimates, distortion and growth theorems, and radius of convexity. Moreover,
we also introduce the class of p-valent functions, denoted by Kk;N
s;p , in this dissertation which further generalizes the class Kk;N s and investigate it for its properties. In addition to investigating properties of geometric functions, many other mathematicians have also
expressed interest in finding sufficient conditions such that certain special functions has
certain geometric properties, such as univalency, starlikeness or convexity. Examples
of special functions that have undergone this investigation include Bessel and Struve
functions. Motivated by this, this dissertation also investigates sufficient conditions for
the function Tp;b;c(z) = (f _ gp;b;c)(z), a convolution between f(z) = z +
1P n=2 anzn and gp;b;c(z) = z + 1P
n=2
The effect of voids on the flexural fatigue properties of carbon/epoxy composites
No full textThe role of voids in composite failures has not been well understood or been characterized. This study presents the result of an investigation aimed at examining the mechanical behaviour of unidirectional carbon fibre-reinforced polymer matrix materials as used by the wind turbine industry. The experimental program investigates the effect of the void content, different manufacturing methods, type of loading (the three-point bending vs. the four-point bending) on the static strength and fatigue life under a flexural load.The four ply unidirectional carbon/epoxy composites were manufactured using the SPRINT and prepreg manufacturing methods. Manufacturing by these methods has successfully produced the composite materials with varied void contents and the voids are found to concentrate primarily in the area where the adjacent plies meet. The SPRINT materials contain voids in the range of 1.63- 2.89% while the prepreg laminates have an average void content of 3.6% for thedebaulked laminates and 6.8% for the non-debaulked laminates. The voids in the SPRINT laminate are small and they are distributed inhomogeneously. The majority of the voids are less than 0.04 mm2 in size with a shape between a circle and an ellipse.The three point bending tests show that the flexural strength exponentially decrease as much as 6.4% for the SPRINT and 6% for the prepreg for every 1% increase of the void content. The similar void effect for both materials may be due to their similar microstructures. There is a similar effect on the increase in the void content for the flexural strength and the flexural fatigue sensitivity for both the three and four point bending tests. This means that the voids do not play any large role in the three-point bending as compared to the four point bending.The mechanism of failure is observed using the optical microscopy and the X-ray tomography of the polished edge and cross section of the area near the failure. The voids are found to interact with the cracks in both the static and fatigue failures. The image of the cross section near the failure area of the static test samples seem to suggest that the voids coalesce to each other under loading. By using the acoustic emission, it can be confirmed that a major failure occurs due to the fibre breakage. In addition, the acoustic emission results also show that the failure behaviour of the low and high void content specimens is significantly different
Efficiency study on vertical-finned crystalliser for concentration of carrot juice
No full textVertical-Finned Crystalliser (VFC) is a new innovation of the progressive freeze concentration method which is applied in concentration of carrot juice. The aim of this research is to observe the efficiency of this newly designed crystalliser in preserving the beta carotene content in the carrot juice concentrate. The crystalliser is equipped with a cooling jacket and extended surface of heat transfer area which makes it possible to obtain high efficiency operation, highly concentrated carrot juice and pure ice layer in the process. The process started with feeding the carrot juice into the crystalliser and the ethylene glycol coolant was pumped into the cooling jacket. Both carrot juice and coolant were circulated in the crystalliser and cooling jacket using two different pumps, until a layer of ice was formed on the inner wall of the crystalliser, including the extended surface/fins. The range of coolant temperature investigated was -6 °C to -12 °C and circulation flowrate of 1,600 mL/min to 2,800 mL/min at constant operation time of 50 min. The efficiency of the process was observed based on the average concentration efficiency value, η (%) and effective partition constant, K using concentration value from the sample absorbance analysis result of UV-Vis spectrophotometer. It was found that the increase in freezing rate (-8 °C) brought about the increase in average concentration efficiency value, η and lower K-value. Meanwhile, the best circulation flow rate was 2,800 mL/min giving higher value of efficiency and lower K-value. The present concentration method using PFC with VFC will be applicable in the industry especially to produce a variety of concentrated liquid food.
, N., Azlan, N., Amran, N.A., Zakaria, Z.Y., Ngadi, N., Hashim, R., Jusoh, M
Optimal injection process parameter analysis for front panel housing using response surface methodology
No full text
Properties of Functions Involving Struve Function
No full textLet f (z) = z + ∑n=2 ∞ anzn and gp,b,c(z) = z + ∑n=2 ∞ (-c4)n-1/(3/2)n-1(k)n-1zn with p, b, c ∈ C, k = p + b+2/2 ≠ 0,-1,-2, . . . be two analytic functions in the unit disk U = (z:|z| < 1). This paper gives conditions so that the function Tp,b,c(z) = ( f * g)(z), a function associated with the Struve function, is univalent, starlike, or convex in the unit disk
Amber filter with self-administered near vision screening card / Saiful Azlan Rosli … [et al.]
No full textVisibility is defined as the greatest distance at which an object can be seen and recognized in either daylight or at night when the general illumination is increased to a daylight level. Visibility can be influenced by several factors, which include colour and contrast. Previous studies, which investigates the effects of colour combinations to level of visibility and visual performance on road signs, found that there is a significant difference in the level of visibility with different colour combinations (p< 0.05). It is clearly understood that in our nature environment and work tasks, each factors described above are variable, which in turn varies the level of visibility. Based on the supportive evidence from previous studies, visual aid such as amber lens can be used as an application to improve the level of visibility of a person in his/her daily work tasks. The amber filters with the near vision screening card can improve people’s eyesight, thus generate substantial economic benefits, and can make a major contribution to Malaysian development. In addition to the filter, the card also consists a modified near vision test that can be selfadministered. This test acts as a simple do-it-yourself screening for near vision. This eventually leads to the users awareness of their own near vision problem. This is inline with the nation’s recommendations in GTP, to drive the high-income countries as well as generate the health and work performance. Previous Study: Ahmad, A., Chen, A., Zulkifli, S., & Rosli, S. A. (2013). UiTM study on road signs in Malaysia : The impact of information volume of road sign on level of visibility. International Journal of Enhanced Research in Science Technology & Engineering, 2(6), 38–41. Aladin, A. Z., Rosli, S. A., & Chen, A. (2012). Visibility Comparison of Colour Combinations Used in Road Sign Design. Universiti Teknologi MARA (UiTM). Publication in reviewed. Iranian Journal of Ophthalmology (IrJO). Rudin, A. M. A., Saliman, N. H., Rosli, S. A., & Ahmad, A. (2011). Enhancement of contrast sensitivity by wearing amber tinted lens between youth hockey player and non-hockey player. 2011 IEEE Colloquium on Humanities Science and Engineering, 902–906. doi:10.1109/CHUSER.2011.6163868
Exploring the Islamic Perspective on Tissue Engineering Principles and Practice
No full textTissue engineering is related to the replacement,
restoration, repair and/or regeneration of
tissues/organs that are tailored to the needs
of the individual patient. The potential
applications of tissue engineering are being
unveiled with much hype and expectations
among the scientists and the public at large. The
demand for engineered tissues may increase
considerably, but the progress has been slow
due to scientific and technical challenges
that linked to moral, religious, philosophical,
political and economic aspects. There are ongoing
debates on certain aspects that seem to
indicate that scientists maybe “playing God”.
This article briefly analyses tissue engineering
principles and the discourse surrounding it.
Subsequently, the author briefly reflects on the
Islamic perspectives, both for and against the
technology. The discussions serve to provide
a platform on how best to achieve a consensus
that adequately deals with the scientific reality
and the Islamic moral and legal jurisprudence
that surrounds the technology
FAT based Adaptive Impedance Control for Unknown Environment Position
No full textThis paper presents the Function Approximation
Technique (FAT) based adaptive impedance control for a robotic
finger. The force based impedance control is developed so that the
robotic finger tracks the desired force while following the reference
position trajectory, under unknown environment position and
uncertainties in finger parameters. The control strategy is divided into
two phases, which are the free and contact phases. Force error
feedback is utilized in updating the uncertain environment position
during contact phase. Computer simulations results are presented to
demonstrate the effectiveness of the proposed technique
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