sheikh ahmad zaki shaikh salim

Universiti Teknologi Malaysia Kuala lumpur

This study examined the mean and turbulent wind speed distribution within the canopy height of a tropical urban campus based on a representative geometry model via wind tunnel experiments. The vertical wind profiles were analysed around two high-rise buildings, Menara Razak (MR) and Residensi Tower (RT) at both wind directions (22.5° and 202.5°). T...

Heat waves continually intensify due to climate change, putting school children’s health and well-being at risk as they spend more time in warm environments. A field study was conducted to investigate the thermal comfort and CO2 concentration in three secondary schools in Malaysia. Field measurements in four classrooms at each school were carried o...

The present experiment is to analyze the effect of blended biodiesel of chicken fat CF10 (10% chicken fat and 90% diesel), waste cooking oil WC10 (10% waste cooking oil and 90% diesel), and combined chicken fat with waste cooking oil CF&WC10 (5% chicken fat + 5% waste cooking oil and 90% diesel) on the performance of diesel engine. The experiment i...

The desk fan as a personal thermal comfort (PTC) device remains an effective thermal adaptation method for office building applications, offering indoor thermal comfort to occupants. However, there are research gaps related to its effect on the skin temperature of office occupants. This study addresses these research gaps by conducting field measur...

Students in naturally ventilated school classrooms are exposed to warmer conditions for extended periods due to intensified heat waves brought on by global warming. This study aims to investigate thermal comfort and assess the overheating risk in three secondary schools in Malaysia. Four classrooms, which consist of students aged 13 to 16 years, we...

The study aims to comprehensively analyze outdoor meteorological conditions and thermal comfort across 592 districts in India, addressing the critical issues of thermal comfort which significantly impacts health, well-being and productivity. Given the anticipated global warming, understanding these factors becomes crucial, particularly for low-inco...

Purpose: This study aimed to explore the impact of empowering society and culinary MSMEs on Sustainable Development Goals (SDGs) in West Java, focusing on Sindangmukti Village, Karawang Regency. While prior research has often used a top-down approach, neglecting direct societal impact, this study takes a bottom-up perspective, aligning with implici...

The quest for efficient dehumidification solutions in modern industries emphasizes the need for advancements in measuring the cleanliness of products and processes, particularly in the context of environmental sustainability. This research explores the potential of natural waste fiber desiccant paper coated with biopolymeric materials. These emergi...

Thermal comfort in the building affects occupants' health, productivity, and electricity use. Predicting occupants' thermal comfort in advance will be helpful. Nowadays, a widely used model for thermal comfort prediction is the predicted mean vote (PMV). However, studies have found discrepancies between PMV and thermal sensation votes. In this pape...

Global warming is mainly triggered by the consumption of fossil fuels and the phenomenon has shaken the global community in the form of climate change resulting in frequent heat waves leading to drought and catastrophic wildfires. At present increase in global average temperature is further increasing energy demands for maintaining thermal comfort...

As the push towards sustainable and eco-friendly solutions intensifies, the valorization of agricultural wastes becomes paramount. Leveraging these wastes not only alleviates environmental concerns but also contributes to value-added applications in various industries. Cellulosic waste fibers, such as empty fruit bunch (EFB) and spent mushroom subs...

The utilization of a desk fan in the personal thermal comfort (PTC) method is a thermal adaptation that provides indoor comfort and energy-saving for office applications due to the high energy consumption of ACs in the HVAC sector. Researchers have conducted numerous studies on this utilization. However, the question of which wind direction provide...

The current study investigated the effect of both the intrinsic and extrinsic parameters of annular flow on the thermal performance of alumina/graphene oxide (Al2O3/GO) for fully developed turbulent flow by A 3-D CFD model. A fully circular annular pipe (the cross-section is a full circle for both the outer pipe and inner rod) and an annular pipe w...

Due to the significant energy consumption of the air conditioner (AC), an alternative energy-saving method is required. To achieve this objective, the design of a building's heating, ventilation, and air conditioning (HVAC) systems must comply to the energy consumption criteria without sacrificing occupant comfort. In this instance, the personal co...

The investigations of flow-induced vibration have been around for decades to solve many engineering problems related to structural element. In a hindsight of advancing technology of microelectronics devices, the implementation of flow-induced vibration for energy harvesting is intrigued. The influence of downstream flat plate to flow-induced vibrat...

The usage of an air–conditioning (AC) system in any building is necessary to maintain its indoor thermal comfort and health. However, this system consumes a lot of energy, while the usage of refrigerant causes irreversible damage to the ozone layer. To solve this problem, a solar thermoelectric radiant panel (PV-TERP) system has a high potential in...

For decades wind tunnel has been utilized to generate a quasi-atmospheric boundary layer to observe the wake flow around objects submerged within the Atmospheric Boundary Layer. The quarter elliptic-wedge spire is the most commonly used as a vortex generator among other passive devices. However, despite numerous past studies that utilize rows of sp...

Personal comfort models were developed to circumvent most of the constraints imposed by the Predicted Mean Vote (PMV) and present adaptive models, which consider the average response of a large population. Although there has been a lot of research into new input features for personal comfort models, the spatial data of the building, such as windows...

There is significant evidence that the COVID-19 virus may be spread by inhaling aerosols leading to risk of infections across indoor environments. Having said that, it is clear that the formulation of indoor air quality (IAQ) needs to be carefully examined. In general, IAQ can be controlled by proper ventilation system across buildings. Nevertheles...

Apart from indoor environmental and personal factors, contextual factors have significantly influenced several thermal comfort studies. In air-conditioned spaces, thermal comfort is conveniently attainable by adjusting the temperature settings, but indoor design elements might alter thermal perceptions and provide adaptive opportunities. This study...

The purpose of this study is to investigate the potential mitigation strategies to overcome the overheating issue at the attic of the landed residential house located in a hot and humid climate area. An existing terrace house with 178 m ² was selected for this research. A building simulation model was created and calibrated by using the previous si...

Natural fibres have remained increasingly applied as reinforcement filler in polymer matrix for fabrication of composites for a long time. Environmentally friendly and sustainable fibres offer the possibility of a feasible substitute and alternative materials to synthetic fibres for a diverse range of products from composite materials. In this rese...

The generator-sets have been widely used as a secondary or an emergency standby power by the society. Despite their several benefits such as their simplicity and reliability, they meet a stability and efficiency decrease when they produce the power. Referring to the above reason, this experimental study is aimed to investigate the potential benefit...

The interest in recovering waste heat has resurged in recent years due to growing concerns about the energy crisis and global warming. A thermoelectric generator (TEG) is regarded as an environmentally-friendly technology for capturing and recovering waste heat by directly converting heat to electrical energy via the Seebeck effect. The critical ch...

Plastic trash has become a huge environmental concern due to the large volumes produced, inflicting substantial harm to both the ecology and its inhabitants. This hazard has a huge impact on the maritime environment. The plastic garbage produced on land eventually makes its way to water bodies, where it has negative consequences such as floods and...

The study evaluated the effect of adding different proportions (3/7, 1/1, and 7/3) of pineapple leaf fiber to composites reinforced with olive trunk leaves powder by measuring tensile properties, moisture absorption, and thermal stability. The results showed that the proportion of pineapple leaf fiber in the hybrid composites strongly influenced te...

IAQ is a crucial factor affecting the health, comfort, and productivity of workers, particularly those working in enclosed spaces like bank offices. This study aimed to evaluate the IAQ of a bank office’s operational area and vault by analyzing concentrations of CO2, TVOC, PM10, and PM2.5, as well as temperature, relative humidity, and air movement...

The use of an air conditioner (AC) becomes essential, particularly in a hot and humid climate, to provide a comfortable environment for human activities. The setpoint is the agreed temperature that the building will meet, and the use of the lowest setpoint temperature to accelerate the cooling of indoor spaces should be avoided. A comprehensive fie...

Malaysia is experiencing rapid population growth and development, which can greatly affect outdoor thermal environments. Therefore, the influence of roadside trees and road orientation on outdoor thermal environment were studied on four different roads in Kuala Lumpur, Malaysia. Field measurements were carried out to evaluate outdoor thermal enviro...

Residential buildings instigate a vital role in creating a safe and comfortable indoor living environment. The phenomenon of overheating, an impact of climate change, can cause a negative effect on residents’ productiveness and heat-related illnesses and can even force high pressure on electricity generation by increasing the risk of power outages...

Floods are among the most destructive natural disasters, and they are extremely difficult to model. Over the last two decades, machine learning (ML) methods have made significant contributions to the advancement of prediction systems that provide better performance and cost-effective solutions by mimicking the complex mathematical expressions of ph...

The biodiesel industry is expanding rapidly in accordance with the high energy demand and environmental deterioration related to the combustion of fossil fuel. However, poor physicochemical properties and the malperformance of biodiesel fuel still concern the researchers. In this flow, polymers were introduced in biodiesel industry to overcome such...

Wind speed in urban areas is influenced by the interaction between wind flow and building geometry; at the pedestrian level, the interaction is more complex, particularly with high building density. This study investigated the wind velocity distribution and the mean velocity ratio at the pedestrian level using the large-eddy simulation (LES) databa...

An H-rotor vertical axis wind turbine (VAWTs) can operate independently in any wind direction, making it aerodynamically efficient and suitable to harness wind energy in low wind speed areas. The aerodynamic efficiency of VAWTs is highly dependent on the blade geometry, especially the blade tip. Tip vortices produced at the blade tips can negativel...

Overcooling indoor spaces in hot-and-humid regions indicate excessive usage of air conditioner (AC). Understanding the occupants' thermal perception in AC settings helps navigate the cooling energy required. This study investigated thermal comfort in biased and non-biased environments and examined the occupants’ preferences. Four set-point temperat...

Rapid population growth and urbanization contribute to an ever-increasing global energy demand, of which the building sector accounts for one-third. The increasing average height and density of buildings escalate the need for vertical transportation, expanding elevator usage and energy needs. This phenomenon accounts for a significant amount of the...

Natural-fiber-reinforced composites, especially bamboo, are an alternative material to compete with conventional materials. Their environmentally friendly, renewable, low-cost, low-density, non-toxic, and fully biodegradable properties are concerning for researchers because of their advantages over synthetic polymers. This comprehensive review pres...

Thermoelectric device is a transformative technology for renewable energy generation. It is designed in a small compact feature with a quiet mechanism and has no gas emission, enabling it to conserve energy and preserve the global environment. Iron disilicide (β-FeSi2/Si) composite materials prepared by eutectoid reaction is found promising for the...

Over the last few years, archaeologist have started to look at automated object detection for searching of potential historical sites, using object identification methods that includes neural network-based and non-neural network-based approaches. However, there is a scarcity of reviews on Convolutional Neural Networks (CNN) based Deep Learning (DL)...

Remote work (working from home) became a norm rather than an exception for the global workforce during the COVID-19 pandemic, influencing every facet of life in both positive and negative ways. The stringent action of the Malaysian government in enacting the Movement Control Order (MCO) motivated the investigation of its impact on the energy consum...

The aim of this study was to clarify the effects of high-rise buildings on the mean and turbulent wind speeds within the canopy layer of an urban university campus in Malaysia. We investigated the characteristics of both mean and exceeding wind speeds by deriving probability density functions of wind speed at a selected canopy height. First, mean w...

Energy-saving strategies are required to address the increasing global CO2 and electrical energy consumption problems. Therefore, the determinant factors of electrical energy consumption consist of socio-demographic changes, occupant behavior, house and appliance characteristics, or so-called techno-socioeconomic factors, which all need to be asses...

This study investigates the mechanical, thermal, and chemical properties of basalt/woven glass fiber reinforced polymer (BGRP) hybrid polyester composites. The Fourier transform infrared spectroscopy (FTIR) was used to explore the chemical aspect, whereas the dynamic mechanical analysis (DMA) and thermomechanical analysis (TMA) were performed to de...

Comfort temperature and sleep quality involving 20 participants were determined in two cases: Case A (arbitrary, controlled air-conditioner setting) and Case B (adjustment of 3 °C higher than the setting of Case A with cool bed linen). Data of indoor thermal comfort and electricity consumption were collected every night throughout the measurement p...

In residential buildings, accurate forecast of time-varying electricity demands is important for the estimation and prediction of electricity consumption. Information of the end user's electricity consumption patterns is necessary as it has a significant impact on the load curve in the utility grid. Thus, this study aims to provide detailed informa...

The suspension system is required in an automobile in order to absorb shock that comes from various type of disturbances such as irregular road profile, engine vibrations and wheel. Besides, the suspension plays an important part in enhancing the passenger ride comfort. The suspension will make sure that the tire is always contacted with the road f...

Utilizing agro-waste material such as rice husk (RH) and coco peat (CP) reinforced with thermoplastic resin to produce low-cost green composites is a fascinating discovery. In this study, the effectiveness of these blended biocomposites was evaluated for their physical, mechanical, and thermal properties. Initially, the samples were fabricated by u...

A rectangular cylinder in a fluid flow is known to show complicated cross-flow vibration behavior due to the interaction between the Kármán vortex-induced vibration and galloping. Wind tunnel experiments were carried out to investigate the cross-flow vibration behavior of several rectangular cylinders for which different stream-wise lengths, B and...

We investigated the displacement and lift time series of a circular cylinder - strip plate cruciform system for energy harvesting in the Reynolds number range 1.1×103≤Re≤14.6×103, numerically using the open source C++ library: OpenFOAM. The Karman vortex-induced vibration (KVIV) regime was identified between reduced velocity, U*, 2.3 and 13.6, whil...

Mathematical model representing the dynamic indoor air temperature of a building is important for reducing the time and cost required to test any proposed thermal comfort control algorithm and strategy for that building through computer simulation. There are many types of mathematical model, and each type has its strength(s) and weakness(es). An au...

Electricity consumption by air-conditioners in residential buildings significantly affects the electrical grid. The stability of the grid can be improved by a precise prediction of air-conditioning (AC) variations. Therefore, more information about the electricity usage patterns specifically on AC load is important. This paper aims to determine the...

The use of an air conditioner (AC) becomes essential in residential buildings, particularly in a hot and humid climate to optimize indoor thermal comfort. To accelerate the process of space cooling, occupants tend to use the lowest set point of the AC thermostat setting to achieve the desired thermal comfort in the indoor environment. A field study...

Accuracy and verification of instruments for thermal environment measurement are important to determine the reliability of measured parameters. The purpose of this study is to propose simple procedures for consistency check on four groups of instruments used in thermal environment measurement: indoor air temperature, outdoor air temperature, relati...

Electricity-saving strategies are an essential solution to overcoming increasing global CO2 emission and electricity consumption problems; therefore, the determinant factors of electricity consumption in households need to be assessed. Most previous studies were conducted in developed countries of subtropical regions that had different household ch...

Understanding the characteristics of natural, wind-induced ventilation of buildings is essential for accurate predictions of ventilation flow rates; however, indoor ventilation is significantly influenced by surrounding buildings. Therefore, a series of wind-tunnel experiments were performed to clarify the relationship between outdoor and indoor ai...

Difficulties in controlling the effects of outdoor thermal environment on the human body are attracting considerable research attention. This study investigated the outdoor thermal comfort of urban pedestrians by assessing their perceptions of the tropical, micrometeorological, and physical conditions via a questionnaire survey. Evaluation of the o...

With rapid urbanization, massive amount of energy is required to compensate the electricity usage thus calls for a need to Malaysian government issuing standard MS1525:2014 for temperature settings in office buildings to meet energy efficiency goal. In co-sharing spaces, personal thermal comfort is often not met due to the different thermal sensati...

Many studies have been conducted to assess the effects of indoor air quality (IAQ) on human health. However, there is still a lack of studies available about the adverse health effects on children’s respiratory health at Child Care Centers (CCC). The aim of this paper was to investigate the risk factors for respiratory symptoms and identify the roo...

As a Malay Agricultural Settlement established in 1900, Kampung Baru which is located in Kuala Lumpur, has become a subject of prolonged national interests in terms of economic, social, environment, and political issues along with the pressure of modern and future development. This study investigated the urban morphological impact of Kampung Baru o...

Over time, urban dwellers have become increasingly concerned with the thermal characteristics in their neighbourhood. Modern Asian cities with their environmental diversity have introduced complexity to urban heat island (UHI) predictions. This research aimed to discover the relative contribution of different environmental and anthropogenic paramet...

Modelling and simulation of the dynamic indoor relative humidity behaviour of a building is essential to test any proposed thermal comfort controller and strategy in the building. Like other plants, the dynamic indoor relative humidity behaviour of a building can be developed based on the white box model, black box model, and grey box model. This r...