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Publication

A Comprehensive Evaluation of Pozzolanic Activity of Ancient Brick Powders Wastes—BPW in Cement Based Materials

( 2022-01-01)

Moncea Mihaela-Andreea

;

Deák G.

;

Dumitru F.D.

;

Roshazita Che Amat

;

Norlia Mohamad Ibrahim

The recovery potential of bricks wastes in obtaining environmental friendly materials is sustained by their pozzolanic properties, which can be exploited within a Portland cement—brick powder waste (BPW) system, thus reducing the amount of waste as well as the consumption of raw materials and CO2 emissions from cement factories. These properties were intensively studied and reported in the literature, for their assessment often being used direct analytical methods to highlight the presence of Ca(OH)2 and its subsequent reduction in abundance with time as the pozzolanic reaction proceeds. Since it is more difficult to quantify the pozzolanic activity of calcined clay in a Portland cement /brick powder mixture, for the present work classical determinations, such as thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM) were combined with the individual assessment of BPW in terms of pozzolanicity in order to study the variation of the Ca2+ respectively OH− ions concentration within a BWP—lime saturated solution. SEM analyses showed CH and CSH formation and the DTA curve highlighted a more intense peak around 500 °C after 28 days of hydration, where the Ca(OH)2 decomposition take place. The pozzolanicity test results showed a pronounced decrease of Ca2+ concentration after 28 days.

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Publication

A recent progress on sustainable construction waste management using 3R (Reduce, Reuse, and Recycle) approach in Malaysia

(Springer, 2023)

S. Abbirahmi

;

Mohamad Anuar Kamaruddin

;

Rasyidah Alrozi

;

Mohd. Mustafa Al Bakri Abdullah

Application of 3R (reduce, reuse, and recycle) is important to reduce dependability for dumping C&DW at landfills, a major environmental problem. Limited legal and enforcement measures have been implemented for construction waste management in Malaysia to ensure safety and quality construction while encouraging the use of the best methods in the industry. The fundamental goal of this research is the potential of recyclable materials and the C&DW management plans are assessed using SWOT analysis. The methodology focuses mainly on four parts, database selection and bibliometric search, refining, and sample selection key concepts, and structuring of the review. C&DW is becoming one of the significant waste sources, surpassing municipal solid waste. Concrete, heavy metal, plastic, and glass are among the C&D wastes highlighted. Reduce, reuse, recycle, compost, incinerate, and dump are the six stages of the waste disposal hierarchy, from low to high. Strengths, weaknesses, opportunities, and threats (SWOT) were analyzed for C&DW management. At the end of the research, a lot of information on the application and the benefits of the 3R method for C&DW are determined.

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Publication

A review on applications of particle image velocimetry

(IOP Publishing, 2020)

N H Hassan

;

M H Zawawi

;

Mohd. Mustafa Al Bakri Abdullah

;

Z M R Rozainy

;

M A Kamaruddin

;

W N Y W M Nasir

;

M A N Mazlan

;

Irfan Abd Rahim

Fluid dynamic field is frequently classified and designated into two which are hydrodynamics and aerodynamics. Particle Image Velocimetry (PIV) has been exerted to many flow problems in a broad range. PIV application to the measurement of velocity distributions in fluid flow is represented by the Stokes number. PIV can be executed to practically for any sort of flow if the fluid is transparent to allow suspended particles image. The purpose of this paper is to present some examples of application of PIV in general cases. In the midst of numerous applications of PIV, turbulent flows are the most comprehensively demanding because of their three-dimensionality, naturally large ranges of length and unsteadiness. Sudden flow field measurements of PIV method can be applied for the demotion of turbulence quantities and mean velocities.

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Publication

A short review: properties of superconducting solder

(IOP Publishing Ltd, 2020)

M.S. Chang

;

Mohd Arif Anuar Mohd Salleh

;

Dewi Suriyani Che Halin

Development of electronic devices were moving towards miniaturization, multifunction and increasingly specific service environment of solder interconnects, where this drive to the higher requirements on the solder properties. Without solder, it would be impossible to produce the infinite electronic devices that define the 21st century. Hence, solder is important in the design and engineering process. This review paper was summarized on the literature of the low-temperature solder systems for superconducting solder materials, which provide further theoretical basis for the study of superconducting solder of electronic and aerospace applications. Pb-Bi system is the most satisfactory solder as a superconducting solder, but due to the restrictions of the lead usage, so new Pb-free superconducting solder need to be invented. Of those Pb-free superconducting materials had been studied, the Sn-In-Bi ternary solder system show the greatest superconducting properties as compared to other Pb-free superconducting solder where TC = 6.9 K, HC2 (4.2 K) = 0.18 T and JC (4.2 K, 0.01 T) = 1.3 × 108 A/m2 respectively. © Published under licence by IOP Publishing Ltd.

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Publication

A short review: reliability issues of lead-free Sn-based alloys for superconducting applications

(Springer, 2023)

Y. P. Tan

;

Flora Somidin

As the trends of electronic devices are moving to miniaturization which requires high-density electronic packaging and high-speed performance, superconducting solder alloy has attracted considerable interest to fulfill the requirements of advanced electronic packaging as it provides sufficient superconductivity which minimizing the loss of current densities carried by superconductors. In the past few decades, leaded superconducting solder alloy were widely used in the industry due to its satisfied performance. However, development of lead-free solder alloy for superconducting applications is initiated to replace leaded solder alloy due to its toxicity. Sn-based solder alloy is the most popular candidate for replacing leaded solder alloy in the industry, but the reliability of Sn-based solder alloy is concerned. This paper reviewed the reliability issues of lead-free Sn-based superconducting interconnects when subjected to high current stressing. Electromigration, thermo-migration, and the subsequence issues caused by high current stressing are covered. This article also summarized the studies done on minimizing the reliability issues of potential Sn-based superconducting solder alloy caused by high current stressing.

Publication

An integration between information systems engineering and software engineering theories towards engineering a novel instrument and framework of web-based systems success: results of the pilot test

(IOP Publishing, 2020)

Ibrahim Eskandar Ibrahim Fadhel

;

Syed Zulkarnain Syed Idrus

;

Mohd Syukri Yeoh Abdullah

;

Amani Ali Elmetwaly Ali Ibrahim

;

Mazni Omar

;

Alaan Ghazi

Due to globalization and speedy of ICT and systems development, more emphasis needs to be on quality of systems and it requires an accurate, fast, effective system so that the success measure of system is essential. Currently systems rate of fall is still a high one of the reasons behind that is the weakness of the available instruments that being used for systems success measurement. This study aims to come out with a successful instrument for successfully system quality measuring. In this article, the results of the pilot test have been illustrated.

Publication

Assessing the applicability of ecological materials obtained with CRT glass

(IOP Publishing, 2020)

Florina-Diana Dumitru

;

Mihaela-Andreea Moncea

;

Andreea-Georgiana Baraitaru

;

Petrache-Ionut Gheorghe

;

Silvius Stanciu

;

György Deák

;

Romisuhani Ahmad

Recovery and recycling of cathode ray tube (CRT) waste glasses has been the focus of research in the last decade, due to their environmental and economie issues (such as leaching of lead ions, high disposal costs). A sustainable method of valorizing this hazardous waste is to embed it in cement, as a substitute for the natural aggregate. Therefore, within the present study, ecological materials with cementitious matrix were synthesized by using glass waste recovered from cathode ray tube monitors (CRT glass), which replaced the aggregate in different proportions (varying from 10 to 30%), and by substituting 25% of cement with lime paste. The compression strength of the obtained specimens was determined after 1, 2, 7 and 28 days of hardening and highlighted that the samples with lower CRT glass substitution percentage performed relatively similar to the reference sample. This behavior can be explained by scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS). The samples microstructure revealed the presence of ettringite, calcium hydroxides, hydrosilicates and hydroaluminates, calcite and some unreacted particles. The opportunity of using these materials in practical applications was assessed by developing masonry specimens - the obtained mortar paste was interposed between two brick slabs, which were mechanically tested after 7 days of hardening. Both splitting tensile strength and flexural strength varied with the increase of CRT glass in the composition.

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Publication

Assessing the recovery opportunities of different types of wastes by their embedment in inorganic binders

(IOP Publishing, 2020)

Mihaela-Andreea Moncea

;

Florina-Diana Dumitru

;

Andreea-Georgiana Baraitaru

;

Mădălina Georgiana Boboc

;

György Deák

;

Rafiza Abd Razak

The use of wastes in the architecture of new binders for construction domain is the key for the success of the progress regarding environmental, technical and economical issues. For instance, bricks wastes have huge recycling value but are often discarded for worthless junk. The wastes glasses which are difficult to be recovered are regularly disposed in landfflls although they successfully could replace the fine and coarse aggregates in concrete. More than that the glass aggregates can be used for decoration of concrete structure floors, patio, entrances etc. Paper slag ash has a similar chemical composition to that of cement, but the mineral phase composition significantly differs and is no reactive with water. Therefore she can be used in the production of concrete, a beneficial idea regarding exhaustible resources and intelligent recycling within circular economy and durable development context. Although the large paper producers fight with this challenge, until now the construction industry didn’t find the courage to tackle these opportunities, continuing to adopt classical methods for designing construction materials. In this context the paper presents reuse potential of different types of wastes as supplementary addition for cement based materials obtaining. In order to demonstrate their functionality the new mortars specimens were mechanically tested. The obtained results highlighted of many times similar properties with that of the classical compositions, sustaining thus the idea of sustainable development within civil industry domain.

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Publication

Assessing the self-healings properties of nano -Ca(OH)₂ - TiO₂ - ZnO materials used in monuments conservation works

(IOP Publishing, 2023)

Moncea Mihaela-Andreea

;

Deak Gyogy

;

Gheorghe (Dumitru) Florina-Diana

;

Norazian Mohamed Noor

;

Nur Liza Rahim

Consolidates based on Ca(OH)₂ have been prepared as macro- and/or nanoparticles dispersed in different alcohols, regardless of the precursor nature. Their efficiency is related to the small dimensions of the particles and the dispersion media, which allows their penetration into the deteriorated material substrates, as well as to an increased reactivity towards CO₂. Besides the consolidating effect there is a strong need for the newly developed materials to also tackle other properties like self cleaning and antimicrobial activity, especially with regards to white monuments. In this context the present work highlights the effect of treating with stable alcoholic suspension containing nano - Ca(OH)₂ - TiO₂ - ZnO the physical support models consisting of mortar cubic samples from hydraulic / aerial lime, a commonly used materials in consolidation works.

Publication

Biotechnology of water treatment based on Algae cultures

(IOP Publishing, 2020)

Cristina Ileana Covaliu

;

Ancuta Nedelcu

;

Gyorgy Deak

;

Oana Stoian

;

Norazian Mohamed Noor

In the current article, we will highlight on the role of algae in the treatment of wastewater. Algae cultures are an interesting solution to tertiary and quandary treatments because of their capacity to use inorganic nitrogen and phosphorus for their growth and to remove heavy metals, as well as some toxic organic compounds, thus, avoiding a secondary pollution. Our experiments were conducted using Chlorella algae for removing lead ions from wastewater. The wastewater treatment efficiency reached a maximum of 86.67% after 80 minutes.

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Publication

Bonding and phases analysis of geopolymer materials

(IOP Publishing, 2020)

Nor Shida Dalila Mohd Azhar

;

Farah Farhana Zainal

;

Mohd. Mustafa Al Bakri Abdullah

This paper presents the bondings and mineral phases exist in geopolymer material consist of raw fly ash, raw metakaolin and also fly ash and metakaolin blend geopolymer. Fly ash used is a waste materials from Lumut power plant by combusting coal while metakaolin was obtained by calcining the kaolin at 750 C for 4 hours. Alkaline activators that act as binder were sodium silicate (Na2SiO3) solution and sodium hydroxide (NaOH) solution with the ratio of Na2SiO3/NaOH is 2.5 to 1. The samples undergo Functional Group Identification (FTIR) and Phase Analysis (XRD). FTIR results show that after geopolymerization process, the band shifted to lower wavenumber (776 cm-1 ) due to interaction of Al atoms in the silicate geopolymer network because of higher cross-linking. XRD results show mineral phases of quartz and mullite in geopolymer after geopolymerization process and it can be said that not all mineral phases from raw material participating in formation of geopolymer matrix.

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Publication

Captive growth analysis of Siberian sturgeon juveniles (Acipenser baerii J. F. Brandt, 1869) fed on a commercial fodder and its importance to a sustainable development of the aquaculture sector

(IOP Publishing, 2023)

György Deák

;

Laurențiu Burlacu

;

Lucian Lumânăroiu

;

Abdulhusein Jawdhari

;

Petrache Ionuț Gheorghe

;

Marius Raischi

;

Elena Holban

;

Irnis Azura Zakaria

Sturgeon aquaculture is an important continuously developing sector within freshwater aquaculture and its sustainability is one of the most pressing matters nowadays. Thus, the urge to apprehend the mechanics of sturgeon growth in captivity as well as in nature is of immediate importance, considering the increase in customers' requests for captive-grown sturgeon meat, caviar, and adjacent by-products. The present study evaluates several canonical growth indices in a controlled, indoor environment that included fluctuations in temperature, dissolved oxygen saturation, and ponderal density (g/L), known to affect sturgeon growth performance. Over the 91 days of evaluation, no significant correlation was found between the weight gain and the ponderal density, dissolved oxygen values, and temperature, among the 4 tanks used in the experiment setup, indicating, along with the lack of significant variance for the RCI per tank, that the growth observed is correlated only with the fodder fed to the fish.

Publication

Characterization and qualitative analysis of pectin from kepok banana peels

(AIP Publishing, 2020)

Halifah Pagarra

;

Anna Y. Hartati

;

Andi Bida Purnamasari

;

Noorhafiza Muhammad

The purpose of this study was to determine the quality and characteristics of pectin in Kepok banana peel using extraction methods. The study refers to the results of optimization (CCD) of pectin with optimum conditions for pectin extraction results predicted at pH (2.5), time and temperature (100 °C). Under optimal conditions, the actual pectin yield was 22.57%. The parameters used are equivalent weight, methoxyl content, galacturonase levels and degree of esterification, qualitative analysis of simple sugars and FTIR characteristics. The results obtained the equivalent weight level of 862.07g/mol, methoxyl content of 3.6% and galacturonic levels or pectin purity of 77.44% and esterification degrees 37.17%. The results of the qualitative analysis of monosaccharides from kepok banana peels pectin showed the presence of arabinose, cellulose, maltose, galactose, fructose and glucose. FTIR characterization results show that functional groups consisting of alcohol groups at 3437cm-1, C-H groups at 2920.32cm-1, C=O groups at 1735.99cm-1, cyclic C-C groups at 1145.75cm-1 and C-O groups at 1016.52cm-1. FTIR spectroscopy with each absorption at a certain wave number shows conformity to the structure of pectin.

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Publication

Chemically chitosan modified with methyl methacrylate and its effect on mechanical and thermal properties of polypropylene composites

( 2013)

Faisal Amri Tanjung

;

Salmah Husseinsyah

;

Kamarudin Hussin

;

Iqmal Tahir

Effects of methyl methacrylate on the properties of chitosan-filled polypropylene (PP) composites has been investigated. Mechanical and thermal properties of the composites were analyzed according to ASTM D 638-91, thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC). The results showed that tensile strength of PP composites decreased upon the addition of chitosan, while Young's modulus improved. At a similar filler loading, the treated PP/chitosan composites were found to have higher tensile strength and Young's modulus as compared with the untreated composites. Thermal analysis results showed that thermal stability and crystallinity of the treated composites were higher than the untreated ones. Scanning electron microscopy (SEM) and Fourier transforms infrared (FTIR) studies revealed less detached filler from matrix on tensile surface of the treated composites as an evidence of enhanced filler-matrix interfacial adhesion due to formation of ester-bridge between the chitosan and the methyl methacrylate.

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Publication

Circular economy-waste reuse into a spongy oxide material with photocatalytic activity for a sustainable development

(IOP Publishing, 2020)

Iasmina- Florina Burlacu

;

György Deák

;

Ecaterina Marcu

;

Ingrid Proriol Serre

;

David Balloy

;

Dewi Suriyani Che Halin

The most recent studies in the field of heterogenous catalysis are directed towards the diffrent anchoring supports for immobilising commonly employed photocatalysts for the degradation of emergent organic compounds from wastewater. The technique of immobilisation of the catalytic semiconductors helps to avoid one of the main technical issue which concerns the post- recovery process of the classical particles in suspension after the water treatment. In the context of the transition towards a circular economy and sustainable development, this paper presents the results regarding a novel catalyst immobilized on fix support starting from some general waste and its photo catalytically functionalization through deposition of various concentrations of zinc oxide on its surface. The morphological and structural characterization of the synthetized oxide spongy materials was performed. This new oxide material presents a great potential as a low-cost, environmental friendly and sustainable water treatment technology.

1 21

Publication

Computational fluid dynamics analysis of gravitational filter based on origami concept (G-Filtro) acted as water filtration device in water tank

(IOP Publisihing Ltd., 2020)

M H Zawawi

;

Mohd. Mustafa Al Bakri Abdullah

;

M A Nazmi

;

W N Yusairah

;

N H Hassan

;

Elyssa Shahira Jupri

;

Mohammad Azam Afiq

;

M A Kamaruddin

;

Mohd Remy Rozainy Mohd Arif Zainol

;

Irfan Abd Rahim

Water is the most demanding resource in the world especially in the era of the rapid growth of population and development. Therefore, delivering good quality water to consumers is important for their security of lives. Gravitational Filter Based on Origami Concept (G-Filtro) is a water filtration device that will be placed in a water tank at the residential area before people consumed it for everyday used. The specialty of this device, it does not necessarily attach to any power source. The objective of this project is to design and develop 3D G-Filtro using 3D CAD software and CFD analysis is used to determine the efficiency of the G-Filtro by simulating and model the pressure, velocity and streamline. Based on the result, the maximum water velocity for simulation without the filter is 0.266 m/s and the maximum velocity for first and second designed filter are 0.254 m/s and 0.243 m/s respectively. From the CFD simulation, the G-Filtro can remove the contaminants in water tank efficiently. Hence, it is proven that G-Filtro can be added as a new water filtration device.

17 1

Publication

Content validity of construction quality management of industrialised building system (IBS) related project in Malaysia

(AIP Publishing, 2020)

Mohd Hafiz Zawawi

;

Nor Syahirah Azman

;

Mohd Zakwan Ramli

;

Nursyadzatul Tasnim Roslin

Construction industry is one of the key players in developing a country. However, the industry is often plagued with the same problem which is maintaining the quality. Industrialized Building System (IBS) has been identified as a potential method to improve overall construction performance in term of quality, cost effectiveness, safety and health, waste reduction and productivity. This paper is to focus on highlighted the success factors and validate the content of an instrument for factors that affect the quality of construction projects in Malaysia. A panel of 37 experts was used to validate the instrument through Content Validity Index (CVI). It was found that the highest kappa coefficient value is 1.000 for item; 'Consideration for the selection and position of special equipment for the transportation and handling of IBS components', 'Site layout has storage areas for materials', and 'Comprehensible structure of process planning and control'.

Publication

Copper alloy reinforced by graphene by powder metallurgy technique

(AIP Publishing, 2020)

M. Yusoff

;

Mohamad M.

;

M. B. Abu Bakar

;

M. N. Masri

;

Nik Noriman Zulkepli

;

Omar S. Dahham

;

M. U. Umar

In this study, the effect of milling speed and compaction pressure on the densification and morphology of CuZn-Gr composite was evaluated. The composite was prepared by using powder metallurgy technique. The effect of the microstructural and compaction were determined based on different milling speed in thus research. The different milling speeds that involved were 175 rpm, 200 rpm, 225 rpm, and 250 rpm. Meanwhile, the different compaction pressures that used in this study were 127.53, 250, 374.67, and 500 MPa. The properties of the milled powder gave the result to green density and densification parameter. The peak XRD of Cu and Zn broadened as milling time increased. The milled powder at 250 rpm has lowest crystallite size and highest internal strain. As the milling speed is increase, the pattern of powder mixture diminished and become smaller due to the well homogenizing powders during milling. Besides, after compaction, 200 rpm and 250 rpm have optimum green density and densification parameter with increasing compaction pressure.

Publication

Corrosion Investigation of Sn-0.7Cu Pb-Free solder in open-circuit and polarized conditions

(IOP Publishing, 2020)

Mohd Zohirul Haziq Aziz

;

Nasihah Zainon

;

Ahmad Azmin Mohamad

;

Muhammad Firdaus Mohd Nazeri

The corrosion performance of Sn-0.7Cu solder alloy was investigated in 1 M hydrochloride acid by means of open-circuit potential and potentiodynamic polarization techniques. In open-circuit potential measurement, the potential showed almost constant reading after achieving potential -550 mV, consistent with single dissolution peak observed in potentiodynamic polarization. This revealed single element dissolution process of Sn took place. Supporting morphological and phase analyses were done by using scanning electron microscope and X-ray diffraction. Phase analysis confirmed the corrosion product are SnO and SnO2. Morphological analysis showed two type of oxide layer formed as corrosion product, which are compact oxide layer and loose rod-like oxide layer after polarization, while rod-like corrosion product was diminished in open-circuit condition. This indicate that complete protection from further corrosion was impossible due to the incomplete passivation layer formation in potentiodynamic polarization.

1 15

Publication

Corrosion studies of fly ash and fly ash-slag based geopolymer

( 2017-06)

F F Zainal

;

S F M Amli

;

K Hussin

;

A Rahmat

;

M M A B Abdullah

This paper presents the results of corrosion studies between Fly Ash Geopolymer (FG) paste and Fly Ash-Slag Geopolymer (FSG) paste. Geopolymer was made from aluminosilicate inorganic polymers mixed with the alkaline activator in order to reduce the carbon dioxide (CO₂) to the ecosystem. Samples then were cured at 60ºC for 24 hours in the oven. Reinforcement bar is placed at the center of the paste. The samples were examined after 7, 14 and 28 days in terms of Open Circuit Potential (OCP) test, phase analysis and morphology analysis. The potential values regarding OCP test for FSG paste from 7 days until 28 days are 0.464 V, 0.474 V and 0.498 V more positive than FG paste which the potential values are 0.087 V, 0.133 V and 0.206 V respectively. From the Pourbaix diagram, all the potential values for FG paste and FSG paste were located in the same Fe₂O₃, passivity region. Passive layer which is the oxide form exists in this region to protect the reinforcement bar from corrosion agents. It can be proved from phase analysis results which iron oxide hydroxide (FeOOH), hematite (Fe₂O₃) and magnetite (Fe₃O₄) peaks exist. The differences of morphological structures of these pastes were observed by Scanning Electron Microscope (SEM). It shows that FSG paste had good corrosion resistance and low corrosion rate compared to FG paste.

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