Life Table, Dessication Tolerance, Breeding Habitats And Midgut Lactobacillus Identification In Dengue Vectors In Penang Island, Malaysia

Virus denggi menjangkiti lebih 100 juta orang setiap tahun dan kemungkinan untuk mengurangkan insiden denggi dikaji di seluruh dunia. Kawalan vektor adalah salah satu pilihan, kerana gangguan penyebaran parasit denggi adala strategi kawalan penyakit yang paling berkesan Dengue viruses infect over 100 million people every year and possibilities to reduce dengue incidence are studied world-wide. Vector control is one of the options, as interruption of transmission of dengue parasites is clearly the most effective disease control strateg

An implicit 2-point block extended backward differentiation formula for integration of stiff initial value problems

A class of implicit 2-point block extended backward differentiation formula (BEBDF) of order 4 is presented. The stability region of the method is constructed and shown to be A – stable. Results obtained are compared with an existing block backward differentiation formula (BBDF). The comparison shows that using constant step size and the same number of integration steps, our method achieves greater accuracy than the 2-point BBDF and is suitable for solving stiff initial value problems

A-stable 2-point block extended backward differentiation formula for solving stiff ordinary differential equations

This paper focuses on derivation of a 2-point block extended backward differentiation formula (BEBDF) for the integration of stiff ordinary differential equations. The formula derived computes two solution values simultaneously in a block and uses an extra future point, thereby having more advantage than the conventional block backward differentiation formula (BBDF). The stability region covered the entire negative half plane, proving that the method constructed is A-stable. To validate the method derived, some problems known to be stiff were solved and the results obtained are compared with the existing BBDF in terms of maximum error and computation time. The comparison shows that the error growth for the new method is smaller compared to 2-point BBDF

Convergence properties of a 2-point using block of 4 backvalues backward differentiation formula

In this paper, we consider the 2-point using block of 4 backvalues Block Backward Differentiation Formula Method (2P4BBDF) that has been developed in [1]. We investigate the convergence properties namely; the order and zero stability of the 2P4BBDF. Zero stability and consistency conditions of the method are established. The order is shown to be 5

Hyper-Erlang Battery-Life Energy Scheme in IEEE 802.16e Networks

IEEE 802.16e networks is one of the broadband wireless technologies that support multimedia services while users are in mobility. Although these users use devices that have limited battery capacity, several energy schemes were proposed to improve the battery-life. However, these schemes inappropriately capture the traffic characteristics, which lead to waste of energy and high response delay. In this paper, a Hyper-Erlang Battery-Life Energy Scheme (HBLES) is proposed to enhance energy efficiency and reduce the delay. The scheme analytically modifies idle threshold, initial sleep window and final sleep window based on the remaining battery power and the traffic pattern. It also employs a Hyper-Erlang distribution to determine the real traffic characteristics. Several simulations are carried out to evaluate the performance of the HBLES scheme and the compared scheme.  The results show that the HBLES scheme out performs the existing scheme in terms of energy consumption and response delay

A new variable step size block backward differentiation formula for solving stiff initial value problems

A new block backward differentiation formula of order 4 with variable step size is formulated. By varying a parameter in the formula, different sets of formulae with A-stability property can be generated. At the cost of an additional function evaluation, the accuracy of the method is seen to outperform some existing backward differentiation formula algorithms. The strategy involved in controlling the step size ratio is also described. The problems tested with the method show its efficiency in solving stiff initial value problems

PEO-hBN-NaClO4 Polymer Composite Electrolyte for Sodium Ion Batteries

A new polymer electrolyte (conducting sodium-ion) based on Polyethylene oxide (PEO) matrix comprising NaClO4 and nano sized hexagonal boron nitride was fabricated via the technique of solution casting for use in sodium ion batteries. Interaction of PEO with Na-ion was investigated with fourier transform infrared (FT-IR) which reveals the extend of Na-ion solvation by PEO (EO:Na). The crystallinity of the polymer electrolyte was investigated with X-ray diffraction (XRD) and thermal properties of the composites were studied with differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DSC results show that the melting temperature (Tm) of PEO decreases addition of both NaClO4 and hBN. TGA results showed that all the composites membranes were thermally stable till 300 oC. Surface morphology of the composite was examined using scanning electron microscopy (SEM) which also reveals the homogeneous dispersion of nano hBN in the polymer matrix. Ionic conductivity of the polymer composite was studied with impedance spectroscopy and PEO5hBN10Na sample showed maximum ion conductivity of approximately 1.4 × 10-3 S/cm at 100 oC

A new fifth order implicit block method for solving first order stiff ordinary differential equations

A new implicit block backward differentiation formula that computes 3–points simultaneously is derived. The method is of order 5 and solves system of stiff ordinary differential equations (ODEs). The stability analysis indicates that the method is A–stable. Numerical results show that the method outperformed some existing block and non-block methodsfor solving stiff ODEs

An improved 2-point block backward differentiation formula for solving stiff initial value problems

A new block method that generates two values simultaneously is developed for the integration of stiff initial value problems. The method is proven to be A – stable and is a super class of the 2 – point block backward differentiation formula (BBDF). A comparison is made between the method, 1 point backward differentiation formula (BDF) and the 2 point BBDF methods. The numerical results indicate that the new method outperformed the 1 point BDF and the 2 point BBDF methods in terms of accuracy and stability. The total number of steps to complete the integration by the 1 point BDF method is reduced to half. Computation time for the method is also competitive

A new superclass of block backward differentiation formula for stiff ordinary differential equations

A superclass of block backward differentiation formula (BBDF) suitable for solving stiff ordinary differential equations is developed. The method is of order 3, with smaller error constant than the conventional BBDF. It is A-stable and generates two points at each step of the integration. A comparison is made between the new method, the 2-point block backward differentiation formula (2BBDF) and 1-point backward differentiation formula (1BDF). The numerical results show that the method developed outperformed the 2BBDF and 1BDF methods in terms of accuracy. It also reduces the integration steps when compared with the 1BDF method