Estimating the Benefits of Beach Recreation: An Application of the Contingent Valuation Method

This study presents an application of the dichotomous choice contingent valuation method to estimate the benefits of beach recreation in Port Dickson. The logit and probit models were used to analyse the data and the willingness-to-pay values were computed from the maximum likelihood estimates. The median willingnessto- pay value for beach recreation in Port Dickson ranged from RM55.01 to RM534.80 for mean income of RM404.56 to RM3933.30, respectively. These values can be used by policy-makers to compute the annual total benefits obtainable from this multiple-use resource

Investigation of the Effects of Inlet System Configuration on the Airflow Characteristics

The effort towards the development of an engine that is efficient and green has become one of the biggest efforts of the major part of the automotive industry. The contribution of air quality to the engine plays an important role to increase power while minimizing the exhaust emission. The main purpose of this article is to investigate the characteristic of the air intake system of a naturally aspirated engine on a steady flow bench. The experiment was conducted using an industrial flow bench apparatus where the pressure different test pressures can be set and, at every test pressure, the valve is lifted at an increment of 1mm until the maximum possible valve lift where the flow rate is obtained in terms of cubic foot per minute or CFM. The experiment process was then repeated at different configuration. The experimental result shows that the flow rate increases with each valve lift in a linear pattern until at a certain point where the value becomes constant. The result also indicated that the flow rate increases as the different pressure increases

Effects of Pilot Injection Timing and EGR on a Modern V6 Common Rail Direct Injection Diesel Engine

Nitric oxide and smoke emissions in diesel engine can be controlled by optimising the air/fuel mixture and combustion temperature. Early in-cylinder diesel injection that produces premixed charge can simultaneously reduce NOx and smoke emissions. However, there could be an increase in hydrocarbons and CO emissions due to fuel impinged to the cylinder wall. The focus of the present work is on the effects of a variation of pilot injection timing with EGR to NOx and smoke level of a modern V6 common rail direct injection. This study is carried out at two different engine load conditions of 30 Nm and 55 Nm, at constant engine speed of 2000 rpm. Emissions of NOx are measured from the exhaust sample line by an exhaust gas analyzer (Horiba MEXA-7100EGR). Smoke level is measured by using an AVL 415S smoke meter which provides results directly as a Filter Smoke Number (FSN) unit. The results show that the early pilot injection timing contributed to the lower smoke level and higher NOx emissions. The higher level of NOx is due to higher combustion temperatures resulting from the complete combustion. Meanwhile, the lower smoke level is due to complete fuel combustion and soot oxidation. The early pilot injection timing produces an intermediate main ignition delay which also contributed to complete combustion. The formation of smoke is higher at a high engine load compared with low engine load is due to the higher amount of fuel being injected, resulting in higher smoke formatio

Effect of particle discretisation and horizon size on the displacement and damage plot using bond-based peridynamics

Peridynamics (PD) represents a new non-local theory of continuum mechanics which uses integro differential equations instead of the typical local partial differential equations in its formulation. Thus, it is suitable for modelling fracture mechanics, where a continuum domain is modelled through particles connected via physical interactions. The PD formulation allows us to model spontaneous crack initiation, and crack branching without the need for special mathematical treatment. The value of parameters such as particle discretisation and horizon size will be checked to make sure that it agreed to the result from Finite Element Method (FEM) in elastic deformation before proceed to the failure mode. In PD, failure criterion is established when its stretch value exceeds a prescribed critical stretch value. In the classical bond model or Prototype Microelastic Brittle (PMB), the bond force grows linearly with the bond stretch, and the value suddenly goes down to zero when the bond stretch exceeds its critical value. This study will focus on the effect of horizon size and particle discretisation on PD displacement of elastic analysis, and damage patterns with PMB damage model. The proposed study leads to a better understanding of how horizon size and particle disretisation affect the damage patterns in PD frameworks

A quasi-brittle damage model in the framework of bond-based peridynamics with adaptive dynamic relaxation method

Peridynamics (PD) is a new tool, based on the non-local theory for modelling fracture mechanics, where particles connected through physical interaction used to represent a domain. By using the PD theory, damage or crack in a material domain can be shown in much practical representation. This study compares between Prototype Microelastic Brittle (PMB) damage model and a new Quasi-Brittle (QBR) damage model in the framework of the Bond-based Peridynamics (BBPD) in terms of the damage plot. An in-house code using Matlab was developed for BBPD with inclusion of both damage models, and tested for a quasi-static problem with the implementation of Adaptive Dynamic Relaxation (ADR) method in the theory in order to get a faster steady state solutions. This paper is the first attempt to include ADR method in the framework of BBPD for QBR damage model. This paper analysed a numerical problem with the absence of failure and compared the displacement with literature result that used Finite Element Method (FEM). The obtained numerical results are in good agreement with the result from FEM. The same problem was used with the allowance of the failure to happen for both of the damage models; PMB and QBR, to observe the damage pattern between these two damage models. PMB damage model produced damage value of roughly twice compared to the damage value from QBR damage model. It is found that the QBR damage model with ADR under quasi-static loading significantly improves the prediction of the progressive failure process, and managed to model a more realistic damage model with respect to the PMB damage model

UPM Pemacu Pertania Lestari - Pertukaran nama universiti selaras perkembangan disiplin pengajian

Daripada Universiti Petanian Malaysia kepada Universiti Putra Malaysia (UPM), UPM sudah mengambil langkah berani menukar nama dan identitinya pada 1997. Namun, hampir sedekad UPM menukar nama, masih ada desas-desus kekesalan terhadap langkah berani ini - kononnyaa ia mengalih arah dan mengeluarkan UPM daripada tonggak disiplin utamanya iaitu pertanian

An Overview of Spark Ignition Engine Operating on Lower-Higher Molecular Mass Alcohol Blended Gasoline Fuels

This paper reviews the utilization of lower and higher molecular weight alcohols as fuel for spark ignition engine. As an alternative fuel for spark ignition engine, alcohol is widely accepted as comparable to gasolin. It is due to its ability that can be produced from biological matter through the current available and new processes. Moreover, alcohol is also considered as fuel additive due to its physical and chemical properties compatible with the requirements of modern engines. The objective of this paper is to provide an overview of these fuels by highlighting on the fuel properties and spark ignition engine responses. The first part of this review explains the important of alcohol fuel properties related to the engine performance and emissions, and the difference of these properties for each type of alcohol. The second part discusses recent advancements in research involving lower and higher molecular weight alcohols mainly responses from spark ignition engine

COMMERCIAL AND SYNTHESIZED ADDITIVES FOR BIODIESEL FUEL: A REVIEW

ABSTRACT In this paper a classification and analysing of commercial and synthesized additives used with biodiesel by different researchers was conducted. Biodiesel is widely accepted as an alternative fuel comparable to petroleum diesel in compression ignition engines. It is relatively poor cold flow property is a characteristic which limits its application. Here, fuel additives become the most viable choice not only to decrease this drawback but also to produce specified products that meet international and regional standards. This article covers a deep and through literature review of the effect of different additives on biodiesel properties, engine performance, and emission characteristics. The additives usage in biodiesel is inseparable both for improving the cold flow properties and for better engine performance and emission control. It can be concluded from the literature that specific additives for biodiesel remain at their infancy. Further research is needed to develop biodiesel specific additives

A sensitive acoustic sensor using fiber bragg grating based on strain compensation

An acoustic sensitivity single ring fiber sensor with enhanced pressure sensitivity is designed by using Fiber Bragg Grating (FBG). Measurement sensitivity of the this fiber sensor is 0.3714 με/Hz. This sensor exhibited a good acoustic sensitivity, showing that the sensor has good sensing properties for the detection of the acoustic signals

Visual Thinking Process and Emotions Through Expressive Art

Background: Drawing has a therapeutic function in the lives of people with special needs.These people need additional support for communication and learning.Researchers believed that drawing is an effective way for these people to show their self-esteem, emotions, social competence, and other hidden personalities. Art therapy teaches knowledge of visual art (drawing and painting). It is also known as expressive art because it assists in dealing with some emotions that are difficult for verbal communication. Furthermore, art therapy is beneficial for fine motor skill development. The aim of this study was to explore the use of expressive art in a group of autistic people. Subjects and Method: This was a qualitative study. A series of art therapy workshop were conducted in University of Malaya in collaboration with Malaysian Rehabilitation Council, and Maybank Foundation. A number of 18 people aged 8-17 years old with autism from Malaysian Rehabilitation Council were invited to University of Malaya for the art therapy workshop. They consisted of Malays, Chinese, and Indians. These peoplehad some level of communication problems. Art therapy workshop was conducted twice a month for 6 month with each session lasted for 4 hours. Art template, art materials, and a list of activities were given to each participant. Before the session, the participants informed the researchers verbally the scope of art that they would be drawing. The researchers observed the thinking process and emotions of the participants through the art activities. Results: Some of the art work was not related to what they have mentioned earlier. We found that art demonstrated their thought process. Drawing was more accurate in visualizing their thinking process rather than verbal communication. Besides, we detected a range of emotions illustrated from their final art work. Some of the emotions were psychological distress, happiness, and sadness. Conclusion: Expressive artis useful for visualizing thinking process of autistic people. Keywords: art therapy, autistic, visual thinking, emotions, expressive ar