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Fulltext Using energy time-frequency of Hilbert Huang transform to analyze the performance of the variable valve timing engine

Mohammed AA, Haris SM

Sci Rep, 2022 Feb 11;12(1):2382.
PMID: 35149750 DOI: 10.1038/s41598-022-06404-3

In this study, a diagnosis method was successfully implemented to identify different sounds coming from individual mechanical parts within a group of engine moving parts controlled through a variable valve timing system. The novelty of this diagnosis method is in the determination of specific sounds coming from each part within this group when they are in good working condition and without any defects. This will facilitate in early detection of faults occurring on the parts, identified through changes in the sound wave energy. Through this study, this diagnosis method was validated in three ways, namely the consistency of the results with previous studies, the synchronization of sounds from mechanical parts in overlapping cases, and the cross-correlation of engine sound modes that results from analysis using the Hilbert Huang Transform. In this paper, the distribution of sound energy according to its frequencies was utilized to distinguish which of the engine combustion chambers of a Dodge Journey 2.4 was faulty. To conduct that, the noise-based test technique was selected to record the engine sound. The results show that there is a link between the RMS energy of the engine sound and the engine output torque.
Using the pressure transmission coefficient of a transmitted wave to evaluate some of the mechanical properties of refractory metals

Mohammed AA, Haris SM, Nuawi MZ

Ultrasonics, 2015 Jan;55:133-40.
PMID: 25096851 DOI: 10.1016/j.ultras.2014.07.001

Refractory metals have attracted increasing interest in recent years because of their use in many high-temperature applications. However, the characteristics of these metals calculated using loaded tests (such as tensile strength tests) differ considerably from those calculated using one of the most famous methods in NDT which is called time of flying of the wave (TOF).The present study presents two solutions based on calculating the pressure transmission coefficient (PTC) of the transmitted wave between the test sample and magnesium metal. The first is based on the development of a highly accurate algorithm that lowers the cost by determining the acoustic impedance of the test specimen to calculating mechanical properties. Up to 26 theoretical tests were done (10 of these tests for refractory materials) according to their known mechanical properties to verify the accuracy of the algorithm. The convergence in results ranged from 92% to 99%. The second solution was designed to solve the same problem for specimens with a thickness of less than 1mm. Eight experimental tests were done (five using refractory materials) to verify the accuracy of the second solution, with the convergence in the results ranging from 94% to 97%. The relationships of the Vrms measured from the oscilloscope with the PTC and with the Fourier transform spectrum were derived. The results of this research were closer to the standard mechanical properties for refractory metals compared with several recent acoustic tests.
Fulltext Estimation of the ultimate tensile strength and yield strength for the pure metals and alloys by using the acoustic wave properties

Mohammed AA, Haris SM, Al Azzawi W

Sci Rep, 2020 Jul 29;10(1):12676.
PMID: 32728209 DOI: 10.1038/s41598-020-69387-z

In this paper, the acoustic impedance property has been employed to predict the ultimate tensile strength (UTS) and yield strength (YS) of pure metals and alloys. Novel algorithms were developed, depending on three experimentally measured parameters, and programmed in a MATLAB code. The measured parameters are longitudinal wave velocity of the metal, density, and crystal structure. 19-samples were considered in the study and divided into 3-groups according to their crystal structure; 7-FCC, 6-BCC, and 6-HCB. X-ray diffraction was used to examine the crystal structure of each sample of each group, while longitudinal wave velocity and metals' density were measured experimentally. A comparison between mechanical properties predicted by the model and the ASTM standards was done to investigate the validity of the model. Furthermore, predicted stress-strain curves were compared with corresponding curves in the pieces literature as an additional validation check. The results revealed the excellence of the model with 85-99% prediction accuracy. The study also proved that if metals are grouped according to their crystal structure, a relation between UTS, YS, and modulus of elasticity (E) properties and wave pressure transmission coefficient (Tr) could be formulated.
Systematic Literature Review of Climate Change Governance Activities of Environmental Nongovernmental Organizations in Southeast Asia

Haris SM, Mustafa FB, Raja Ariffin RN

Environ Manage, 2020 11;66(5):816-825.
PMID: 32893336 DOI: 10.1007/s00267-020-01355-9

Environmental nongovernmental organizations (ENGOs) are considered key players for engendering good climate change governance to address both climate change and sustainable development. The participation of ENGOs in climate change governance occurs in a four-phase policy cycle. They include (1) identification of policy options, (2) policy formulation, (3) policy implementation, and (4) policy monitoring and evaluation. The ENGOs, however, have been criticized for their lack of effectiveness, and their roles in tackling climate change remain unclear. To date, the study on the roles and activities of Southeast Asian ENGOs in climate change governance has been under-researched. This study, therefore, applies a systematic literature review of 19 published articles from Scopus and Web of Science-indexed journal to understand the current state of the Southeast Asian ENGOs participation in climate change governance based on the four-phase policy cycle. The findings show that the ENGOs in Southeast Asia are involved directly and indirectly in climate change governance. They are significant actors in the implementation of the climate change policy, but they play a minimal role in the formulation of said policy. It implies that they could also be a vital partner to the government in the climate change governance process as they can bring effective policy improvements. Lastly, this review will recommend future avenues of research for scholars.
We're making it work! UKM'S Speech Sciences Programs' teleclinic experience in the time of COVID-19

Ahmad Rusli Y, Hassan FH, Haris SM, Mohd Azraai H, Md Almi SN

Med J Malaysia, 2021 08;76(Suppl 4):52-54.
PMID: 34558561

This paper highlights issues, challenges, and lessons learnt from implementing a speech-language therapy teleclinic service delivery model by the Speech Sciences Program, Universiti Kebangsaan Malaysia (UKM) during the wake of the recent COVID-19 pandemic. The teleclinic service provision was initially started to help our student cohorts attain and complete the required direct contact speechlanguage therapy clinical hours for graduation during the pandemic. It has since evolved to be an integral part of the clinical practicum curriculum and a service delivery model that is here to stay. Although far from perfect, the program hopes to systematically continue our endeavours in telerehabilitation as one of our niche areas, realising the wealth of benefits that this service delivery model has to offer.
Fulltext Comparisons of Clients' and Caregivers' Satisfaction Across Conventional, Virtual, and Hybrid Speech-Language Therapy Services in Malaysia

Hassan FH, Zakaria AS, Ahmad Rusli Y, Haris SM, Mohd Azraai H

Patient Prefer Adherence, 2023;17:1731-1740.
PMID: 37492636 DOI: 10.2147/PPA.S407347

PURPOSE: This study compared the satisfaction of recipients of conventional speech-language therapy (C-SLT), speech-language teletherapy (SLTT), and hybrid speech-language therapy (H-SLT), and determined sociodemographic factors that affect their satisfaction.
PATIENTS AND METHODS: Participants were clients and caregivers of a speech-language clinic at a public university. Services were primarily provided by student clinicians, who were undergoing supervised clinical training. An online survey was distributed, which consisted of three sections: Background Information, Overall Satisfaction in SLT, and Satisfaction in SLTT. All participants completed the first two sections, while the third section was completed only by those who experienced SLTT or H-SLT.
RESULTS: Most of the respondents were caregivers (89.7%), female (79.4%), of Malay ethnicity (80.9%), have received tertiary education (77.9%), within the low-income category (66.2%), held a job (76.5%), and resided in central West Malaysia (83.8%). Many participants experienced C-SLT (51%), followed by H-SLT (34%), and SLTT (15%). There were no significant differences in the overall satisfaction of the participants across three modes of services delivery (F[2,67] = 0.02, p = 0.95), and in the satisfaction with teletherapy between the H-SLT and SLTT groups (t = 0.90, p = 0.38). Income was the only sociodemographic factor that was correlated with the satisfaction level in teletherapy (r = 0.37, p = 0.04).