Determination of filler content in rice husk ash and wood-based composites by thermogravimetric analysis

Three new types of fillers for polypropylene are investigated. The first two were derived from burnt rice husk ash (RHA), whereas the third, a wood-based filler, was processed from oil palm trunk. One important characterization of the composites involves the checking for the actual filler content and filler distribution within the matrix. An analytical technique is described here for computation of the filler content in the composites based on a simple expression derives from thermogravimetric analyses. For filler with volatiles such as the black RHA, the derived expression was p _f = 106 ( r _b / m _c ), and for easily burnt fillers (wood-based), the expression was p _f = 156 ( m _d / m _c ). The technique has shown good agreement and consistency between analyzed and actual filler contents and a uniform filler distribution within the polypropylene matrix. © 1994 John Wiley & Sons, Inc.     

Fungal resistance of densified ammonia-impregnated oil palm stem

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Engineering education in rapidly industrialising Malaysia

Malaysia aspires to be a fully industrialised nation by the year 2020. This has brought about a shift from what was predominantly an agriculturally-based economy to a rapidly expanding manufacturing-based one. This shift has brought to the fore the need for a large pool of people, especially engineers, with a strong base in science and technology. The government has embarked on various programmes to launch the bandwagon. This paper describes some of these programmes and measures that have been implemented or are now being planned, with a focus on engineering and engineering education at the tertiary level. Some recommendations are also made for supplementing the programmes already in place     

Production of a diacylglycerol-enriched palm olein using lipase-catalyzed partial hydrolysis: Optimization using response surface methodology

Partial hydrolysis using Lipozyme RMIM lipase in a solvent-free system was used to produce a diacylglycerol (DAG)-enriched palm olein. Response surface methodology (RSM) was applied to model and optimize the reaction conditions namely water content (30–70 wt% of enzyme mass), enzyme load (5–15 wt% of oil mass), reaction temperature (45–85 °C) and reaction time (6–16 h). Well fitting models were successfully established for both DAG yield (R² = 0.8788) and unhydrolysed triacylglycerol (TAG) (R² = 0.8653) through multiple linear regressions with backward elimination. Chi-square test indicated that there were no significant (P > 0.05) differences between the observed and predicted values for both models. All reaction conditions had positive effects on DAG yield and negative effects on unhydrolysed TAG. Optimal reaction conditions were: 50 wt% water content, 10 wt% enzyme load, 65°C of reaction temperature and 12 h of reaction time. The process was further up-scaled to a 9 kg production in a continuous packed bed bioreactor. Results indicated that upscaling was possible with a similar DAG yield (32 wt%) as in lab scale. Purification of the DAG oil using short path distillation yielded a DAG-enriched palm olein with 60 wt% DAG and 40 wt% TAG which is suitable for margarine, spread or shortening applications.     

Stabilizing toxic metal concentrates by using SMITE

Synthetic mineral immobilization technology is an approach for the treatment of heavy-metal concentrates. Although the notion of using synthetic mineral analogs for the stabilization and consolidation of nuclear waste has been discussed for more than 40 years, its application to inorganic hazardous waste, in general, is only now being realized. The advantage of this technology is that high-waste-loaded and high-density waste forms can be fabricated while maintaining excellent chemical durability. These properties translate into considerable savings during transport and disposal.     

A functional approach to redesign

This paper describes a methodology to assist in the identification of possible conceptual design variants during redesign. The approach is based on functional reasoning and involves: (1) the structural and functional analysis of an existing design; (2) the production of abstract representations of functions and design entities using conceptual graphs; and (3) design interrogation based on a functional tree approach. The research reported in this paper also focuses on the definition and the representation of elementary mechanical functions. Extended Backus-Naur Form (EBNF) notations are used to structure in a computable form, the relevant information (or design knowledge) conceptualised in either the conceptual graphs or the functional trees. EBNF syntax is also used to formulate rules which aid the partial automation of the reasoning process. The EBNF notations can be mapped to any programming language. A diaphragm valve is used as a case study to demonstrate the approach.     

Cell arrival modeling and related statistical multiplexer performance in ATM networks

A source is assumed to go through independently distributed ON and OFF periods. During an ON period, cells arrive spaced apart in time by a fixed interval. No cells arrive during an OFF period. The probability distribution of the ON and OFF periods are arbitrary. Traffic from a number of such sources is statistically multiplexed. The related statistical multiplexer performance is studied analytically as follows. A statistical multiplexer is modeled as a discrete-time single-server queueing system where the traffic from a new source (conforming to the cell arrival process described above) joins traffic that is already being statistically multiplexed. The aggregated arrival of cells from existing traffic is assumed to follow a two-state Markov modulated cell arrival process. Numerical examples that relate the performance at the statistical multiplexer to the parameters describing the traffic from the new source and the aggregated traffic are presented.This research was supported in part by the National Science Foundation under Grant No. NCR-9016348, and by the Pacific Bell External Technology Program.     

Bioinspired and Hierarchically Textile-Structured Soft Actuators for Healthcare Wearables

Soft pneumatic actuators possess the increasing potential for various healthcare applications, such as smart wearable devices, safe human-robot interaction, and flexible manipulators. However, it is difficult to translate the existing technologies to commercial applications due to their inefficient volumetric power, sophisticated control with high operation pressure, slow production, and high cost. To overcome these issues, herein, a caterpillar-inspired actuator using hierarchical textile architectures based on simple fabrication and low-cost strategy is designed. Unlike the existing textile-based pneumatic actuators, the designed actuators are constructed by combining boucle fancy yarns with a novel trilayer-knit architecture. The as-prepared actuators concurrently possess fast response (1100° s⁻¹), large bending actuation strain (1080° m⁻¹), high-power density (272 W m⁻³), mechanical robustness, easy-programmable motions, and human-tactile comfort, which outperforms currently reported textile-based pneumatic actuators. Furthermore, due to the geometrical transition of the engineered hierarchical structure, the developed actuators exhibit superior dual-stiffness effect with stress evolution, providing a facile approach to addressing the conflict of flexibility and force output in soft fluidic actuators. This concept as a paradigm provides new insights to develop soft actuators with outstanding design flexibility, adaptability, and multifunctionality using engineered textile-structure, which has great potential for real-world applications in medical rehabilitation, physiotherapy, and soft robotics.