Preparation and Properties of Biodegradable Polymer Film Based on Polyvinyl Alcohol and Tropical Fruit Waste Flour

In this study, two different types of tropical fruit waste flour, rambutan waste flour (RWF) and banana waste flour (BWF), were blended with polyvinyl alcohol (PVOH) by solution casting method. The structure of the blend film was characterised by Fourier Transform Infrared Spectroscopy. The tensile strength and elongation at break of tropical fruit waste flour-filled polyvinyl alcohol were lower, but the tensile modulus was higher, than that of PVOH film. At a similar blend ratio, the tensile properties of the PVOH/RWF film were higher than the PVOH/BWF film, but the PVOH/BWF film showed higher water uptake than PVOH/RWF film.     

Efficiency of hydrogen internal combustion engine combined with open steam Rankine cycle recovering water and waste heat

A hydrogen internal combustion engine (HICE) wastes more heat, and producing nearly three times more water than a conventional engine. This paper describes the principle behind a novel waste heat recovery sub-system that exploits the water produced by an HICE as the working fluid for an open-cycle power generation system based on the Rankine cycle. Water from the HICE exhaust is superheated by the waste heat from the HICE and used to produce power in a steam expander. A fundamental thermodynamic model shows the contribution of the sub-system to the overall thermal efficiency of the HICE at various engine speeds, with and without a condenser. The results show that the condenser is not cost-effective and that the overall thermal efficiency with the proposed sub-system is 27.2% to 33.6%, representing improvements of 2.9% to 3.7%, at engine speeds of 1500 to 4500 rpm.     

An ANFIS-based approach for predicting the bed load for moderately sized rivers

A total of 346 sets of bed-load data obtained from the Kinta River, Pari River, Kerayong River and Langat River were analyzed using four common bed-load equations. These assessments, based on the median sediment size (d₅₀), show that the existing equations were unable to predict the measured bed load accurately. All existing equations over-predicted the measured values, and none of the existing bed-load equations gave satisfactory performance when tested on local river data. Therefore, the present study applies a new soft computing technique, i.e. an adaptive neuro-fuzzy inference system (ANFIS), to better predict measured bed-load data. Validation of the developed network (ANFIS) was performed using a new set of bed-load data collected at Kulim River. The results show that the recommended network can more accurately predict the measured bed-load data when compared to an equation based on a regression method.     

Spectral analysis methods for vehicle interior vibro-acoustics identification

Noise has various effects on comfort, performance and health of human. Sound are analysed by human brain based on the frequencies and amplitudes. In a dynamic system, transmission of sound and vibrations depend on frequency and direction of the input motion and characteristics of the output. It is imperative that automotive manufacturers invest a lot of effort and money to improve and enhance the vibro-acoustics performance of their products. The enhancement effort may be very difficult and time-consuming if one relies only on ‘trial and error’ method without prior knowledge about the sources itself. Complex noise inside a vehicle cabin originated from various sources and travel through many pathways. First stage of sound quality refinement is to find the source. It is vital for automotive engineers to identify the dominant noise sources such as engine noise, exhaust noise and noise due to vibration transmission inside of vehicle. The purpose of this paper is to find the vibro-acoustical sources of noise in a passenger vehicle compartment. The implementation of spectral analysis method is much faster than the ‘trial and error’ methods in which, parts should be separated to measure the transfer functions. Also by using spectral analysis method, signals can be recorded in real operational conditions which conduce to more consistent results. A multi-channel analyser is utilised to measure and record the vibro-acoustical signals. Computational algorithms are also employed to identify contribution of various sources towards the measured interior signal. These achievements can be utilised to detect, control and optimise interior noise performance of road transport vehicles.     

Thermoeconomic optimization for a finned‐tube evaporator configuration of a roof‐top bus air‐conditioning system

This paper presents a methodology of a design optimization technique that can be useful in assessing the best configuration of a finned‐tube evaporator, using a thermoeconomic approach. The assessment has been carried out on a direct expansion finned‐tube evaporator of a vapor compression cycle for a roof‐top bus air‐conditioning (AC) system at a specified cooling capacity. The methodology has been conducted by studying the effect of some operational and geometrical design parameters for the evaporator on the entire cycle exergy destruction or irreversibility, AC system coefficient of performance (COP), and total annual cost. The heat exchangers for the bus AC system are featured by a very compact frontal area due to the stringent space limitations and structure standard for the system installation. Therefore, the current study also takes in its account the effect of the variation of the design parameters on the evaporator frontal area. The irreversibility due to heat transfer across the stream‐to‐stream temperature difference and due to frictional pressure drops is calculated as a function of the design parameters. A cost function is introduced, defined as the sum of two contributions, the investment expense of the evaporator material and the system compressor, and the operational expense of AC system that is usually driven by an auxiliary engine or coupled with the main bus engine. The optimal trade‐off between investment and operating cost is, therefore, investigated. A numerical example is discussed, in which a comparison between the commercial evaporator design and optimal design configuration has been presented in terms of the system COP and evaporator material cost. The results show that a significant improvement can be obtained for the optimal evaporator design compared with that of the commercial finned‐tube evaporator that is designed based on the conventional values of the design parameters. Copyright © 2007 John Wiley & Sons, Ltd.     

Detection and quantification of palm mid‐fraction in a chocolate model system

The tocopherol and tocotrienol compositions of the genuine cocoa butter (CB) and palm mid‐fraction (PMF) were investigated to introduce a more reliable indicator in detecting PMF in CB. The results suggested that the α‐tocotrienol data presented could be utilised for the detection of the PMF admixture to CB. The PMF was added to CB at different levels. HPLC was used to detect the presence of PMF admixture to CB using α‐tocotrienol as an indicator. The results derived from the model system indicated that increasing the PMF amount at 0–15% to CB resulted in an increase in the concentration of the α‐tocotrienol significantly (P < 0.05). The addition of PMF amount more than 15% did not have any effect on the α‐tocotrienol concentration. A linear plot with a high correlation of 0.9967 was obtained with SE of 1.527. The high correlation obtained indicated good accuracy, reflecting a close relationship between experimental and theoretical predicted value.     

Study of morphology and gas separation properties of polysulfone/titanium dioxide mixed matrix membranes

Polysulfone (PSf)‐based mixed matrix membranes (MMMs) with the incorporation of titanium dioxide (TiO₂) nanoparticles were prepared. Distribution and agglomeration of TiO₂ in polymer matrix and also surface of membranes were observed by scanning electron microscopy, transmission electron microscopy, and energy dispersive X‐ray. Variation in surface roughness of MMMs with different TiO₂ loadings was analyzed by atomic force microscopy. Physical properties of membranes before and after cross‐linking were identified through thermal gravimetric analysis. At low TiO₂ loadings (≤3 wt%), both CO₂ and CH₄ permeabilities decreased and consequently gas selectivity improved and reached to 36.5 at 3 bar pressure. Interestingly, PSf/TiO₂ 3 wt% membrane did not allow to CH₄ molecules to pass through the membrane and this sample just had CO₂ permeability at 1 bar pressure. Gas permeability increased considerably at high filler contents (≥5 wt%) and CO₂ permeance reached to 37.7 GPU for PSf/TiO₂ 7 wt% at 7 bar pressure. It was detected that, critical nanoparticle aggregation has occurred at higher filler loadings (≥5 wt%), which contributed to formation of macrovoids and defects in MMMs. Accordingly, MMMs with higher gas permeance and lower gas selectivity were prepared in higher TiO₂ contents (≥5 wt%). POLYM. ENG. SCI., 55:367–374, 2015. © 2014 Society of Plastics Engineers