Volume 34(03) 2022

Table of Contents

Front Page

No. Article Page  
1. E-Procurement Adoption in the Malaysian Construction Sector: Integrating Diffusion of Innovations and Theory of Planned Behaviour Framework

Noorsaidi Mahat, Asmah Alia Mohamad Bohari, Mohd Azrai Azman, Natasha Khalil, Amira Shazlin Adnan & Mohd Iskandar Abd Malek

In recent years, environmental problems have become more prominent in the construction industry. The production and use of building materials are still one of the main reasons for various ecological and environmental challenges in the industry. Compared with traditional building materials, green building materials are environmentally friendly. Therefore, the adoption of green building materials in the construction industry can generally solve the industry’s ecological and environmental problems and promote green and low-carbon development. Research on contractors’ green procurement behaviour can promote the construction industry’s sustainable development. Many scholars discuss and agree that the implementation of e-procurement is a green approach towards sustainable construction. However, current evidence indicates that procurement stakeholders, especially contractors, are struggling to implement e-procurement effectively. Therefore, there is a need to study contractors’ behaviour in relation to green e-procurement. In response, this study investigates the adoption of e-procurement by Malaysian contractors by adopting planned behaviour theories and diffusion of innovations in their decision-making process. Here, a conceptual framework has been developed which focuses on factors influencing contractors’ adoptions. The framework can be used for understanding the contractors’ adoption decision of e-procurement. The result will help to find the critical key factors affecting green procurement behaviour from contractors’ perspectives and extend the theories further. This framework is also in tandem with the Construction Industry Development Board (CIDB), Construction 4.0 Strategic Plan (2021-2025) in identifying critical factors that affect the adoption of green procurement on construction projects.

Keywords : e-Procurement; theory of planned behaviour; diffusion of innovations; conceptual framework

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-01
2. A Review of Chemical Demineralization and Desulphurization of High Ash & High Sulphur Lignite Coal

Mansoor Ahmed Lakhmir, Suhail Ahmed Soomro, Imran Nazir Unar & Faheem Akhter

Globally, large reserves of low grade or lignite coal are available. Low-ranking coal contains high mineral content, moisture content, and low calorific value. The major problem in coal is sulphur and ash When used for combustion, this type of coal imposes harmful impacts on the environment. It results in the production of greenhouse gases and ash, which are hazardous for the environment and human health. Usually, the demineralization and desulphurization process is used to remove the minerals matters before its use in industrial processes such as combustion, carbonization, gasification and liquefication. Which are harmful to the environment if combusted untreated. Therefore, the number of upgrading technology is being used to reduce the mineral matters from coal and save the environment. The current paper reviews the potential of demineralization and desulphurization processes to enhance the usability of lignite coal. Moreover, it focuses on preserving the high-grade coal which is already depleted in abundance.

Keywords: Mineral matters; Demineralization; Desulphurization

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-02
3. Influence of Cutting Fluid on Machining Processes: A Review

Alaba Oladeji Araoyinbo, Mosunmola Bose Edun, Ayuba Ushe Samuel, Azmi Rahmat, Matthew Biola Biodun & Mohammed Mustafa Albakri
Abstrak Bahasa Melayu

Machining process in Manufacturing system is the removal of material to produce a desired shape, size and, or weight of a particular part. This involves the use of cutting, grinding and boring tools as the case maybe, the process itself is not free from challenges that includes reduction in tool life which are usually affected and also the effect of friction which affects machine parts. Therefore, an engineering practice in manufacturing system is required to eliminate or bring to bare minimum the challenges in this machining processes, hence the cutting fluid technology is researched to be a solution solving process. Cutting fluids are widely used and has been majorly seen as a necessary additive to enhance output and increased quality machining operations. The effect of friction leads to sudden rise in cutting temperature and tool wear during machining which impair the quality of the final product. The highly recognized cooling techniques utilized between the several cooling techniques used in metalworking are nanofluids, cryogenic systems, and cooled trodden air. The utilization of cutting fluids cannot be overlooked during machining process as it forms strong defensive films in the contact territories at low speed, making the grip frailer and averting the creation of stores, hence, lowering friction between two mating parts. The resultant effect of good cutting fluid during machining operation enhanced good surface roughness and better service life of the device and suitable finished surface of workpiece that are subjected to machining operations.

Keywords: Chip; Cutting Fluids; Lubricant; Machining; Metalworking; Productivity

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-03
4. A Review Study on Theoretical Comparison Between Time-Dependent Analysis Models for Prestressed Concrete Bridges

Ali Fadhil Naser

Particularly, concrete material involvements creep under a continuous load and practices shrinkage due to variations in humidity proportion. These physical properties variations growth over time. Prestressed losses according to concrete creep and shrinkage will lead to loss of compression strength for concrete. Time-dependent analysis is important and essential for two types of prestressed concrete which are pretensioned and posttensioned with the effect of time, variations in the structural pattern, and high erection loads influence the structural performance and protection of structure for the duration of erection and when complete. Creep and shrinkage are the main time-dependent parameters of concrete. They are important parameters in the design of prestressed concrete structures such as bridges. The objective of this study is to review the analysis models of time-dependent parameters for prestressed concrete bridges by using shrinkage and creep factors equations to determine the strain of time-dependent parameters. Creep and shrinkage parameters were selected to review the effect of these parameters on the properties of prestressed concrete. Nine analysis methods for creep and shrinkage of concrete were reviewed in this study. These models include ACI-209 model, PCI-BDM model, CEB-FIP-90 model, AASHTO-LRDF model, Shams and Kahan model, NCHRP-496 model, B3 model, GL2000 model, and AFREM model. It was recommended that using this methodology to determine shrinkage and creep factors for prestresssed concrete bridge and comparing between the results of analysis models.

Keywords: Time-dependent; model; creep; shrinkage; moisture; prestressed concrete

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-04
5. Toughening Mechanisms in Particulate Dental Resin-Based Composites: A Short Review

Fathie Kundie & Zainal Arifin Ahmad

Resin-based composites represent a unique class of restorative dental materials; however, these composites have severe shortcomings such as low wear resistance which is mainly responsible for the short life-span of the materials. Composites characteristics such as strength, stiffness, resistance to abrasion, polymerisation shrinkage, thermal expansion coefficients and moisture absorption depend on the filler particles and coupling agents used. Fortunately, these composites have been the focus of attention for numerous researches in recent years which aim to improve the performance of the restorations in several ways. Using several types of coupling agents, and different particle sizes and types have gained the great interest of researchers. The latter plays a critical role in the toughening mechanisms in resin-based composites. Therefore, the purpose of this review is to discuss the literature regarding the toughening mechanisms in particulate dental resin composites since these mechanisms are also crucial factors for the improvement of mechanical properties. The four main types of toughening mechanisms discussed are: crack deflection, pinning, bridging and particle-matrix interface. The current review indicates an improvement in mechanical properties of particle-filled dental composites due to the presence of various toughening mechanisms. The dental resin composites’ fracture toughness is mainly contributed by crack deflection, pinning and bridging that take place in micro- and nanocomposites, in addition to the hybrid composites. Filler–matrix interphase plays an important role in improving the mechanical properties, in addition to its positive effect on crack deflection and bridging. In reality, all these mechanisms could occur simultaneously at different intensities, respectively.

Keywords: Particulate dental composites; crack deflection; crack pinning; particle/matrix interactions; crack bridging; toughening mechanisms

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-05
6. Determination of Thermal Expansion Coefficient for Ball Grid Array using Digital Image Correlation

Yat Sheng Kong & Liam Crosbie

This paper presents the analysis of coefficient of thermal expansion (CTE) of solder ball on a ball grid array (BGA) through digital image correlation (DIC) technique. The assessment of thermal mechanical properties of semiconductor component is a main challenge due to the sensitivity of micro-scale components to heat. However, the CTE analysis of BGA is significant to address the issues of thermal mismatch strains which lead to failure. Meanwhile, the measurement of solder ball heat expansion is in microscale and heated conditions where the traditional method of strain measurements is ineffective. In this analysis, a micro DIC system was used to measure the strain value of solder balls when it was subjected to temperature loading in a heating stage. The actual temperature of the solder ball was measured using a thermocouple inside the heating stage to ensure uniformity of the temperature. The measured strain during the specific temperature was obtained and plotted for CTE using linear analysis. The average value of CTE for the measured solder ball was 27.33 × 106 / oC. The results indicated that the measurement was close to the reference value of solder ball CTE. This analysis provides a reliable analysis of BGA using a developed DIC method.

Keywords: Digital image correlation, Coefficient of Thermal Expansion, Solder ball, Thermal-mechanical

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-06
7. Mathematical Model to Predict Split Tensile Strength of Concretes in Crude Oil Contaminated Environments

J. C. Ezihe, O. O. Ugwu & F. O. Okafor

Few concrete components used for constructions within the Niger Delta region of Nigeria are contaminated with crude oil to varying ranges. An investigation into the split tensile behaviour of concretes to crude oil when cured in 10% crude oil/water medium is carried out in this work. In this work, crude oil was used as a fifth ingredient of concrete mix which replaced 5% to 20% of the w/c. The four other components were cement, sand, granite, and water. A designed mix ratio of 1:2:4 with w/c of 0.5 was utilized as the initial component mix design. Scheffe’s simplex theory was used for the five mix ratios in a {5,2} experimental design. This gave rise to ten additional mix ratios and fifteen other additional mix ratios were generated for control purposes. These thirty concrete mix ratios were subjected to laboratory experiments to determine the 7 and 28 days split tensile strengths. The results of the first fifteen split tensile strengths were used for the calibration of the model constant coefficients, while the results from the second fifteen were used as control. A mathematical regression model was derived from the results, with which the split tensile strengths were developed. The derived model was subjected to a two-tailed t-test with 5% significance, which ascertained the model to be adequate with an R2 value of 0.9616 and 0.9227. The study revealed that crude oil presence in a concrete mix can be harmful as it reduces the split tensile strength of concretes.

Keywords: Crude oil; Scheffe’s simplex lattice design; Split Tensile

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-07
8. Penghasilan Model 3D Tapak Parking Menggunakan Terrestrial Laser Scanner
Generating a 3D Model Parking Lot by using Terrestrial Laser Scanner

Sharifah Lailaton Khadijah binti Syed Abdullah & Siti Kamisah binti Mohd Yusof

Nowadays, the usages of Terrestrial Laser Scanner (TLS) have been practise widely use in the mapping and modelling of varies field. This is because of the advantages that TLS provided; such as speed in data collecting, high accuracy as well as saving time. One of the main technologies of TLS is by producing a 3 Dimension (3D) that can be analysed from a surface of an object and form of the real world. TLS is practically use in Civil Engineering or Geographic Information System (GIS) for objects modelling and reviewing tunnels volume whereas for Archaeology it be used by maintaining the details of cultural heritage. However, TLS has not been analysed in 3D for the parking area. The main purpose of this study took place is to prove the ability of TLS in producing and analysing into 3D modelling for this particular area. The study has been done at the parking lot of the Department of Survey and Mapping (JUPEM), Kuala Lumpur. The methods that been used for this study are by using a 3D Terrestrial Laser scanner (TLS), Leica Scan Station C10, image point cloud registration, 3D modelling, Cyclone software, parametric modelling 3D and Autodesk Revit. From this study, it helps the JUPEM department in producing 3D detailing plan as well as speed up the outcome of retrieving details for an object and can be presented in tangible form without physically going to the particular area or a site. Therefore, with this introduction of 3D modelling technology towards the relevant fields, it can help others in solving problems for internal infrastructure for buildings and structures.

Keywords : Terrestial Laser Scanning; Autodesk Revit; modelling 3D

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-08
9. Evaluating the Performance of Traffic Flow using SIDRA for Roundabouts in Ipoh, Perak

Samikhah Muhammad & Sharinatol Akmanida Jamaludin

Due to rapid development and urbanisation, the traffic systems in Perak are developing and continuously growing in numbers. Evaluation of junction concerning capacity and safety is very important since it is directly related to delay, level of service, accident, operation cost and environmental issues. Traffic congestion happens due to delay and reduction of average speed during AM Peak hours at two roundabouts. This study aims to improve the traffic flow by determining the LOS at two different roundabouts. A traffic study was conducted at “Bulatan Bahagia” and “Bulatan Sultan Iskandar” in Ipoh. Sidra 5.0 application was used as an alternative to Highway Capacity Manual to analyze the junction and LOS performances. This analysis was carried out using SIDRA Software 5.0 to determine the LOS at “Bulatan Bahagia” and “Bulatan Sultan Iskandar” in Ipoh. This study provides recommendations to improve the roundabout performance. The result shows the improvement in the level of service from LOS F to LOS B and from LOS F to LOS D. The percentages of reduction for delay were 2 % and 5% respectively. The finding shows that speed on road has a direct correlation with traffic congestion. The speed improves up to 57 % and 20 %. The analysis indicates that Sidra application utilisation gives the best alternative design for intersections and improve the LOS due to sustainable traffic demand on both upstream and downstream roundabouts.

Keywords: Sidra Application 5.0; roundabout; level of service; delay; speed

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-09
10. Experimental Analysis for Performance of Concrete with Addition of Steel Fibres, SBR and Polypropylene Fibres

Mohd. Gulfam Pathan, Rajan L. Wankhade, A.M. Shende, Ajay Swaroop & Nuha Mashaan

Sufficient experimentation is observed in literature to examine the brittle behaviour of concrete. Presently, addition of different modified polymer and fibres can be treated as an effective way for improving the behaviour of concrete. Steel fibres are now generally mixed with concrete as because of such fibres sufficient strengths are gained. Fibre Reinforced Concrete acquires high stiffness, strength and durability subjected to different environment. In this experimental investigation it is mixed steel fibres with concrete with various percentages (0.35% to 0.85%) with addition of Polypropylene fibre. The primary objective is first to check whether the employment of steel fibres allows the improvement in strength. Next objective is to verify the effect of a mixing of steel fibres and modified polymer namely SBR. The third objective of the present study deals with the combination of steel fibres with synthetic polypropylene fibres in varying percentages. Preparation of specimen is performed in lab for different contents% of styrene butadiene rubber polymer with the hooked end SF. The experimental program includes cube, cylinder and beam specimens with fabricated in 1% to 10% steel fibres. Further 15% modified polymer-SBR is added in the different mixes. After this 0.15% to 0.25% polypropylene is mixed to M30 and M40 grade of concrete. The volume fraction for fibre having 100 kg/m3 of steel fibres (1.27% Vf) may be effectively employed. It is seen that by varying the %contents of SF’s and SBR; strong bond is developed leading to bridge of micro cracks by the polypropylene in RC members.

Keywords: Steel fibres, SBR, polypropylene fibres, flexure strength

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-10
11. Rainfall Analysis for Rainwater Harvesting in Politeknik Ungku Omar

Mazlina Alang Othman & Hasliza Zulkifli

Rainwater Harvesting System (RWHS) is a collection and storage of rainwater for future use and have many benefits related to the economy, environment, technology, and society. Malaysia is well positioned to harvest rainwater because of number of rainy days in Malaysia is high and average of rainfall amount 2500 mm annually. Because of the effects of the topography of Peninsular Malaysia, rainfall distribution varies significantly. Thus, rainfall data analysis for rainwater harvesting potential should be made based on local climate and influences from the monsoon. The objective of this study was to analyse the rainfall data for rainwater harvesting potential in Politeknik Ungku Omar (PUO). To simplify analysis, rainfall distribution is discussed within two monsoons which is Southwest monsoon and Northeast monsoon while rainfall trend is determined under the year 2000 to 2019. The result indicates that PUO will be potential for RWHS regarding to high number of rainfalls event and increasing trend in annual rainfall amount in that area. Further research is clearly needed to investigate the roof size and water consumption to increase the effectiveness of the RWHS.

Keywords: Rainwater harvesting system; rainfall distribution; rainfall trend

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-11
12. The Weightage of Environmental Elements for Malaysia State Green Road Index of Rural Area

Nurul Ashikin Shuhaimi, Noraziah Hamid & Rozana Zakaria

“Green road” is a concept introduced to meet the requirements of economic, societal, and environmental aspects in road construction and its operation. Towards the responsive efforts of sustainable development, many countries had established their environmentally friendly green road assessment tools including for highways and roads. However, the application of the tools is somehow limited to specific project life cycle such for design and planning assessment and/or only for the higher cluster of the road such as toll road or federal highway, but rarely focus on road in rural area. This paper therefore aims to identify the appropriate environmental criteria and elements as proposal for Malaysia State Road Index for the rural area. The weightage of environmental elements for the Malaysia State Road Index for the rural area was established in the discussion of this paper. The environmental criteria and elements were reviewed via critical literature review of content analysis were of ‘green tools’. The confirmation of weightage was conducted via questionnaires development and responded by the focus group discussion (FGD) and validation survey. The FGD were the experts involved in road infrastructure development. The data is analysed using the Statistical Package for the Social Sciences (SPSS) software. This study discovered ten sub-criteria and thirty-three elements under ‘green road’ of significant environmental sustainability elements. The result showcases a fair distribution of weightage for each element within their sub-criteria.

Keywords: Green roads; green tools; environmental sustainability; criteria; weightage

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-12
13. A Study of Left Ventricular (LV) Segmentation on Cardiac Cine-MR Images

Md Atiqur Rahman Ahad & Israt Jahan

Left ventricular segmentation from cardiac images has high impact to have early diagnosis of various cardiovascular disorders. However, it is really a challenging task to segment left ventricular images from magnetic resonance image (MRI). In this paper, we explore several state-of-the-art segmentation algorithms applied on left ventricular (LV) segmentation on cardiac cine-MR images. Both adaptive and global thresholding algorithms along with region-based segmentation algorithm have been explored. Edge-based segmentation is disregard due to the absence of edge information in the employed dataset. For evaluation, we explored a benchmark dataset that was used for the MICCAI 3D segmentation challenge. We found that the cardiac MRI global thresholding has proved to be much efficient and robust than the adaptive thresholding. We achieved more than 92% accuracy for global thresholding, whereas, about 78% accuracy for the adaptive thresholding approach. The use of entropy or histogram to characterize segmentation in place of the intensity value of the pixel has a vital effect on segmentation efficiency. It is evident that the intensity information is corrupted by acquisition procedure, as well as the structure of organs. Due to the lack of boundary information in cardiac cine-MRI, clustering and region-based segmentation have produced more than 93% segmentation accuracy. For the case of soft clustering, the increased accuracy is found as 96%. However, more explorations are required, specially based on deep learning approaches on very large datasets.

Keywords: MRI; cine-MRI; Left Ventricular Segmentation; cMRI; Medical Imaging

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-13
14. Predictive Analysis of Azure Machine Learning for the Rheological Behaviour of Unaged and Polymer Modified Bitumen

Abdalrhman Milad, Sia Zhen Xian, Sayf A. Majeed, Abobaker G. F. Ahmeda, Munder Bilema, Naeem Aziz Memon, Ahmed Elmesh, Atef Abu Salim, Qadir Bux alias Imran Latif & Nur Izzi Md Yusoff

Rheology can be defined as the primary measurement associated with bitumen flow and deformation characteristics. In the long term, DSR testing consumes a long time, expensive cost and skilled labour to operate equipment or machines in the laboratory. The complex modulus, G* and phase angle, δ, are essential parameters for characterising and predicting the rheological behaviour of unaged bitumen (UB) and polymer-modified bitumen (PMB) in the model. This study developed three regression models using Azure machine learning (AML) to predict the rheological behaviour of UB and PMB. There are three types of data used as input data to develop the regression model: temperature, frequency, and modified material content. Regression models were developed with three processes or steps that need to be prioritised: data collection, model preparation, and model validation. Algorithms used in model development are decision tree regression (DFR), boosted decision tree regression (BDTR) and linear regression (LR). The results show G* and δ values. The R2 values in the G* and δ predictions obtained from the DFR models are 0.8199 and 0.9480, respectively. Moreover, the R2 values in the G* and δ predictions obtained from the LR models are 0.4219 and 0.7836, respectively.

Keywords: Rheology; complex modulus, phase angle, δ and Azure machine learning, regression models

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-14
15. Image Watermarking Technique for Digital Al-Quran based on Fibonacci Transform via DWT

Nasharuddin Zainal, Seri Mastura Mustaza & Wan Noormaheran Wan Hussin

Advent growth in information and communication technologies has accelerated the needs to secure digital media. Demands for digital media when on the move urged Quran readers to install the Quran mobile apps on their device. However, there is no secure mechanism to legalize its content credential. On the other hand, mobile developer finds difficulty in getting access to readily authentic Quran database sources. Malaysia government has introduced Smart Quran mobile apps without any counterfeit protection. Correspondingly, the contents are vulnerable to hacking, falsification which consequently endangering Islamic institutional prestige. There is also a lack of credible authorization institutions to verify authenticity of the digital Quran that could possibly deviate the Muslim faith by reciting falsified content and meaning. To fill the void, this paper explores the utilization of an image watermarking to preserve the Quran digital image. The study presents new blind RGB image watermarking using Fibonacci Transform via Discrete Wavelet Transform (DWT) and manipulates the R component of the Al-Quran image. The second level of LL decomposition of the cover image will then be substituted by the Fibonacci-transformed watermarked version. DWT embedding is achieved through alpha blending technique. Final watermarked image is obtained once RGB conversion is performed. The efficiency of the method is assessed towards 10 samples. Verification is conducted via the extraction of the endorsed license image. The results demonstrate enhanced robustness and imperceptibility with average PSNR and SSIM of 92.13 dB and 0.99 respectively. Forgery cases of digital Quran applications are therefore tackled.

Keywords: Image Watermarking; Digital Al-Quran; Fibonacci Transform; Discrete Wavelet Transform (DWT)

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-15
16. Techno Economic Analysis of Cotton Stalk Biomass Based Bio-Oil Production Using Slow Pyrolysis Process

Jinesh B. Shah & Janak B. Valaki

In Indian context, green energy mission can be fulfilled through harvesting green energy from agriculture residue which is available abundantly. Slow pyrolysis may be a prominent technology to convert these low value agricultural biomasses into high value products such as Bio-oils, Pyro- gas and Bio-char, which finds vast applications as energy sources. Authors in this paper have presented a Techno-economic analysis of cotton stalk through slow pyrolysis process .Lab scale slow pyrolysis process was performed in batch scale Pyrolyzer at 500 °C temperature, 10 C°/min heating rate and 1-hour residence time as input parameters and Bio-Oil, Bio-Char and Pyro-Gas were obtained as output of slow pyrolysis process having process yields of 36.60 %, 37.78% and 25.25% respectively. Bio-oil and bio-char can be used to generate direct revenue, while pyro-gas may be used as energy source for process heating. Entire plant was assessed economically by considering nth process plant assumption and 20 Tone/day capacities. Techno economic viability of plant was assessed by evaluating plant capital investment and operating cost. Plant capital investment was calculated based on total purchased equipment cost where as Total purchased equipment cost was calculated using equipment scale factor. Operating cost of entire plant was analyzed based on fixed capital investment. Plant economic evaluation was carried out by evaluating Minimum fuel selling price; Payback period and net present value. Estimated Minimum fuel selling price of the plant was ₹66.30/Liter ($ 0.068/liter), payback period of the plant was 3 years and Positive cash flow in Net Present Value.

Keywords: Techno Economic Analysis (TEA), slow pyrolysis, Cotton stalk, Payback period, Net Present Value (NPV)

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-16
17. Influence of Pelletizing Conditions on Fabricated System Performance, Physical and Mechanical Properties of a Cassava Flour Based Fish Feed

Oduntan, Oluwafemi Babatunde*, Bamgboye, Adeleke Isaac & Oladimeji, Olumide Joshua

Conventional screw press fish pelleting machines are commonly used as a method of producing fish feed, but often affect the product properties. Manual pelletizers using hydraulic press instead of screw in a cassava flour-based diet can be easily processed, which can improve handling and storage. The influence of the pelletization parameters on some properties of cassava-based pellets was the focus of this study. The conditioning factors analyzed were: die size (4, 6 and 8mm), temperature (30, 60 and 90oC), cassava inclusion (5, 10, 15 and 20%) and the influence of the mash moisture content (35, 40 and 45%) on the process and product responses. The quality of the pellets was evaluated in view of current standards. Second-order polynomials were applied to demonstrate the responses as a function of process factors. The studied factors had significant effects on the process response (throughput) and pellet properties (durability and bulk density). Majority of the values of throughput, bulk density and durability of the produced pellets attained the standard limits. Pelletizer operated optimally with processing parameter at 6.0 mm die size, 60°C temperature, 40% moisture content and 20% cassava inclusion rate resulted in pellet temperature (64.4°C), moisture content (34.21%), throughput (932.26 g h-1), bulk density (0.36 g cm-1), durability (99.1%) and hardness (0.30 kN). Pelleted feed using a manual press device under high cassava containment improves the properties of the product. Therefore, the applicability of the response surface method to optimize the process variables is sufficient.

Keywords: Conditioning; Throughput; Product responses; Optimally; Quality

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-17
18. Characterization of Chemical-Physical Properties on a Dried Waste of Sago Pith

Nur Tantiyani Ali Othman & Norhafizah Mohd Asnari

Sago palm is the oldest tropical plant that has been explored to get starch. However, untreated sago waste is often disposed to the nearest river, and it will contribute to the environmental problem. Since it still has a high content of starch, namely amylose and amylopectin, it has the potential to be turned into other high value-added products such as poultry feed, bioassay, and substrate in laccase production. However, before it can be converted, it must be dried to the desired moisture level. Its chemical-physical properties must be evaluated before it can be applied to ensure its composition fulfils the substrate specification for other usages. After it has undergone the drying process via the fluidized bed dryer, the analysis of its chemical-physical properties, determination of its moisture content, fat content and solubility in a distilled water must be performed. The results showed the final moisture content of samples were MCf=9.2-10.9 w/w% that fulfil the minimum specification; MCf≤12 w/w%. In addition, the fat content of samples was <1%, and the water solubility increased at a higher temperature. This occurred due to the gelatinization process when the water bath temperature exceeded 60oC. Besides, it was determined that the optimum drying temperature was achieved at T=106.6oC with the optimum drying time was t=56 minutes, and the optimal temperature of the water bath was at T=60oC. These optimal conditions are very crucial and should be considered as the sago pith tends to be retrograded.

Keywords: Sago; Moisture content; Fat; Water solubility; Poultry feed

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-18
19. Numerical Investigation of the Effect of Uniform Cutout on Performance of Ultrasonic Horn for Machining Nomex Honeycomb Core Material

Khurram Hameed Mughal, Muhammad Asif Mahmood Qureshi, Asif Ali Qaiser, Fazal Ahmad Khalid, Syed Farhan Raza, Adnan Maqbool, Shehzad Ahmad & Jianfu Zhang

Ultrasonic horn is utilized in order to enhance the amplitude of vibration transmitted by the transducer in an ultrasonic machining system. It plays a vital role in vibration amplification to a magnitude suitable for efficient machining of materials. Ultrasonic machining system has to operate at a frequency of at least . Therefore, horn may be subjected to high magnitude of stresses leading to failure. Mechanical horn is designed to get optimum vibration amplification while keeping stresses in acceptable limits. In this research an ultrasonic compound horn was designed with through cutout of uniform diameter. The performance of ultrasonic horn was observed by varying the cutout diameter by modelling horns of four different materials: titanium, aluminum, steel and stainless steel respectively. Modal analysis was performed for computing modal frequencies in the axial direction, whereas harmonic analysis was carried out in order to determine vibration amplitude, stresses and factor of safety. The effect of varying frequency ratio on vibration magnification, stresses, and factor of safety were also investigated. The axial modal frequency was observed to increase, whereas amplitude of vibration and stresses were observed to decrease by increasing the cutout size. Titanium was found to be the most suitable material for ultrasonic horns, because it provided up to 159.4 % more amplitude of vibration and 3 times higher safety factor thus operating life as compared to other materials.

Keywords: harmonic analysis; magnification; modal analysis; stresses; ultrasonic horn; uniform cutout

DOI : dx.doi.org/10.17576/jkukm-2022-34(3)-19