Evaluation of Row-wise Manipulations for the Forensic Differentiation of Malaysian Soils based on Ultra-performance Liquid Chromatographic Profiles

Journal of Analytical Chemistry - Soil is useful physical evidence for linking a suspect/victim to a particular crime scene. However, the discrimination of soils from neighboring locations can be a...     

Boundary Layer Flow over a Continuously Moving Thin Needle in a Parallel Free Stream

We investigate the boundary-layer flow on a moving isothermal thin needle parallel to a moving stream. The governing equations are solved numerically by a finite-difference method. Dual solutions are found to exist when the needle and the free stream move in the opposite directions.     

Boundary Layer on a Moving Wall with Suction and Injection

We investigate the boundary-layer flow on a moving permeable plate parallel to a moving stream. The governing equations are solved numerically by a finite-difference method. Dual solutions are found to exist when the plate and the free stream move in the opposite directions.     

In situ small-angle neutron scattering and rheological measurements of shear-induced gelation

The microscopic structure of shear-induced gels for a mixed solution of 2-hydroxyethyl cellulose and nanometer-size spherical droplets has been investigated by in situ small-angle neutron scattering (SANS) with a Couette geometry as a function of shear rate gamma. With increasing gamma, the viscosity increased rapidly at gamma approximately 4.0 s(-1), followed by a shear thinning. After cessation of shear, the system exhibited an extraordinarily large steady viscosity. This phenomenon was observed as a shear-induced sol-gel transition. Real-time SANS measurements showed an increase in the scattering intensity exclusively at low scattering angle region. However, neither orientation of polymer chains nor droplet deformation was detected and the SANS patterns remained isotropic irrespective of gamma. It took about a few days for the gel to recover its original sol state. A possible mechanism of gelation is proposed from the viewpoint of shear-induced percolation transition.     

Mixed Convection Stagnation-Point Flow Over a Vertical Plate with Prescribed Heat Flux Embedded in a Porous Medium: Brinkman-Extended Darcy Formulation

This article considers the problem of mixed convection stagnation-point flow towards a vertical plate embedded in a porous medium with prescribed surface heat flux. It is assumed that the free stream velocity and the surface heat flux vary linearly from the stagnation point. Using a similarity transformation, the governing system of partial differential equations is transformed into a system of ordinary differential equations, before being solved numerically by a finite-difference method. The features of the flow and the heat transfer characteristics are analyzed and discussed. It is found that dual solutions exist for both buoyancy assisting and opposing flows.     

Fixed point and homotopy results for multivalued maps satisfying an implicit relation

We present some common fixed point theorems for multivalued maps satisfying an implicit relation on complete metric spaces. Also a homotopy result is given for multivalued maps.     

Photochrome-coupled metal complexes: molecular processing of photon stimuli

The frontiers of novel photoresponsive materials constructed with photochromes and transition metal complexes are surveyed in this review. Strategies to develop new photofunctions are categorized into four types. In the first category, intramolecular electronic interactions between photochromes and metal complexes produce entangled responses such as redox-regulated photochromic reactions or tristable photochromism. In the second, light-induced molecular structural rearrangements of photochromes induce the transformation of flexible and labile coordination structures, which can be applied to complex photomechanics or photoelectron conversion. In the third, the photochromic moiety also acts as a photonic switch, transmitting a metal-metal interaction when it is located between two metal complex moieties. The last category concerns the development of new photochromic reactions, involving metal-ligand bond rearrangements. These reactions potentially induce drastic electronic tuning of the metal center, and can be used to develop light-driven molecular machines.     

Photoresponsive molecular wires of FeII triazole complexes in organic media and light-induced morphological transformations

A lipophilic linear FeII 1,2,4-triazole complex containing azobenzene chromophores forms molecular wires in organic solvents; photoisomerization of azobenzene units induced morphological changes that lead to reversible, macroscopic gel-to-sol transition phenomena.     

Dual solutions in mixed convection boundary layer flow of micropolar fluids

The steady mixed convection boundary layer flow over a vertical surface immersed in an incompressible micropolar fluid is considered in this paper. Employing suitable similarity transformations, the governing partial differential equations are transformed into ordinary differential equations, and the transformed equations are solved numerically by the Keller-box method. Numerical results are obtained for the skin friction coefficient and the local Nusselt number as well as the velocity, angular velocity and temperature profiles. Both cases of assisting and opposing buoyant flows are considered. It is found that dual solutions exist for the assisting flow, besides that usually reported in the literature for the opposing flow. Moreover, in contrast to the classical boundary layer theory, the separation point of the boundary layer is found to be distinct from the point of vanishing skin friction.     

Experimental investigation on seam geometry,microstructure evolution and microhardness profile of laser welded martensitic stainless steels

This paper investigates the effects of energy density on geometry of the weld seam and development of microstructures at various weld zones. Energy-based local microhardness profiles are made and linked with the formation of the microstructures. Weld resistance at the interface is energy-limited and seam profile only changes from conical to cylindrical after a certain limit of energy input. Microstructures in the fusion zone changes from cellular to columnar dendritic and equiaxed dendritic with increasing energy input. Variation in morphology of microstructures across the fusion zone is evident within the weld. A distinct region exists in between fusion and heat affected zones due to retention of the primary ferrite. Local microhardness reaches its peak in the fusion zone and decreases gradually from fusion zone to base metal of the outer shell. In the inner shell, peak microhardness occurs in HAZ and the local softening relative to fusion zone and HAZ is visible at the fusion boundary.