Browsing Khairel Rafezi Ahmad, Associate Prof Dr. by Author "Khairel Rafezi, Ahmad, Dr."

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    • Chitosan pH Sensor 

      Irwana, Nainggolan, Dr.; Khairel Rafezi, Ahmad, Dr.; Tulus Ikhsan, Nasution (Universiti Malaysia Perlis, 2010-01-07)
      Chitosan is a natural biomaterial derived from the alkaline deacetylation of chitin that is present in many crustaceans, insects and mollusk shells.

    • Development of dense hydroxyapatite-ni by modified electroless deposition technique. 

      Sri Asliza, Md Amin; Mohd Zaheruddin, Kasmuin; Azmi, Rahmat, Dr.; Shamsul Baharin, Jamaludin, Prof. Dr.; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2014)
      Ni deposited on HA powder was prepared by electroless plating process without sensitization and activation treatment. The deposited powder obtained was characterized by energy dispersive spectroscopy (EDX) and x-ray ...

    • Dry sliding wear behaviour of A390 hypereutectic (Al–Si) alloy 

      Riyadh A., Al-Samarai; Haftirman, Idrus; Khairel Rafezi, Ahmad, Dr.; Yarub, Al-Douri (Universiti Malaysia Perlis (UniMAP)Pusat Pengajian Kejuruteraan Mekatronik, 2012-02-27)
      The behavior of wear for dry alloy A390 of (aluminum–silicon) casting which constitutes 16% Si is investigated. The lost of the wear rate is weighted and the volume decreases with increasing speed of sliding as well as ...

    • Effect of different nickel content on the mechanical properties of hydroxyapatite-ni composites from coated powders 

      Sri Asliza, Md Amin; Mohd Zaheruddin, Kasmuin; Azmi, Rahmat, Dr.; Shamsul Baharin, Jamaludin, Prof. Dr.; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2014)
      HA-Ni composites were fabricated by uniaxial pressing from coated powders, in which HA particles were successfully coated with nickel precursor by the electroless deposition method. The compacted powders sintered at ...

    • Effect of roughness of hypo-and hyper-eutectic Al-Si piston alloy on wear characteristics under lubrication 

      Riyadh A., Al-Samarai; Haftirman, Dr.; Khairel Rafezi, Ahmad, Dr.; Yarub, Al-Douri, Dr. (Malaysian Technical Universities Network (MTUN), 2012-11-20)
      The tribological behavior of tow AlSi alloys under the influence of surface roughness average was investigated for the present study. The silicon content of these alloys ranged 10 and 16-wt% Si, and includes hypoeutectic ...

    • Effect of roughness of hypo-and hyper-eutectic Al-Si piston alloy on wear characteristics under lubrication 

      Riyadh A., Al-Samarai; Haftirman, Dr.; Khairel Rafezi, Ahmad, Dr.; Yarub, Al-Douri, Assoc. Prof. Dr. (Elsevier B.V., 2013)
      The tribological behavior of tow Al-Si alloys under the influence of surface roughness average was investigated for the present study. The silicon content of these alloys ranged 10 and 16-wt% Si, and includes hypoeutectic ...

    • Effect of spot welding current and cycles on the mechanical properties of welded galvanized steel sheets 

      Shamsul Baharin,  Jamaludin, Prof. Dr.; Mazlee, Mohd Noor, Dr.; Muhammad Rifki, Ismail; Khairel Rafezi, Ahmad, Dr.; Kamarudin, Hussin, Brig. Jen. Dato' Prof. Dr. (Trans Tech Publications, 2013)
      Studies on the effects of welding current and cycles were carried on the galvanized steel sheets using spot welding. The welding currents used were 3 kA, 5 kA 6 kA and the welding cycles were 4, 6 and 8. Tensile shear and ...

    • Effect of temperature of oxalic acid on the fabrication of Porous anodic alumina from Al-Mn alloys 

      Mohd Nazree, Derman, Dr.; Foo, Kai Loong; Khairel Rafezi, Ahmad, Dr.; Uda, Hashim, Prof. Dr.; Voon, Chun Hong (Hindawi Publishing Corporation, 2013)
      The influence of temperature of oxalic acid on the formation of well-ordered porous anodic alumina on Al-0.5 wt% Mn alloys was studied. Porous anodic alumina has been produced on Al-0.5 wt% Mn substrate by single-step ...

    • Electrochemical measurement of PBS using cyclic voltammetry and AAO fabricated at ambient temperature and low potential 

      Alaba Oladeji, Araoyinbo; Mohd Nazree, Derman, Dr.; Azmi, Rahmat, Prof.; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2013)
      Anodic aluminium oxide fabricated at ambient temperature and low potential in phosphoric acid electrolyte was used as the working electrode for the electrochemical measurement of phosphate buffer saline under different pH ...

    • Evaluate the effects of various surface roughness on the tribological characteristics under dry and lubricated conditions for Al-Si alloy 

      Riyadh A., Al-Samarai; Haftirman, Dr.; Khairel Rafezi, Ahmad, Dr.; Yarub, Al-Douri, Assoc. Prof. Dr. (Scientific Research Publishing Inc. All rights reserved., 2012-07)
      The effect of surface roughness average of hypereutectic aluminum silicon alloys (with 16 wt% Si) on the friction and wear was investigated. Various surface roughness average (Ra) of different degrees was verified as well ...

    • Fire resistance of biomass ash panels used for internal partitions in buildings 

      Roshazita, Che Amat; Norlia, Mohamad Ibrahim; Nur Liza, Rahim; Nur Saidatul Balqish, Ahmad Tajudin; Khairel Rafezi, Ahmad, Dr. (Malaysian Technical Universities Network (MTUN), 2012-11-20)
      constructions. This study develop new products made of by biomass ash from industry waste for the internal partitions panel. Modifying the internal partition panel of wall with addition of biomass ash (EFB) and clay soils ...

    • Fire resistance of biomass ash panels used for internal partitions in buildings 

      Roshazita, Che Amat; Norlia, Mohamad Ibrahim; Nur Liza, Rahim; Nur Saidatul Balqish, Ahmad Tajudin; Khairel Rafezi, Ahmad, Dr. (Elsevier B.V., 2013)
      This study was to develop fire-resistant panels with a high biomass ash ratio from the combustion of EFB at an industrial scale to be used in different fire-resistant internal partitions in buildings and industrial ...

    • Intermetallic compound formation on solder alloy/cu-substrate interface using lead-free sn-0.7cu/recycled-aluminum composite solder 

      Flora Somidin; Mohd Arif Anuar, Mohd Salleh; Khairel Rafezi, Ahmad, Dr. (Scientific.Net, 2012-12)
      Feasibility of using recycled-Aluminum (re-Al) as reinforcement particulates in Sn-0.7Cu is assessed by powder technology method, whereby re-Al particulates are produced from discarded aluminum beverage cans. This paper ...

    • Kinetic and thermodynamic studies on adsorption of copper ions onto pomelo peel (citrus grandis) 

      Mst. Noorzahan, Begum, Dr.; Aimi Noorliyana, Hashim; Md Fazlul, Bari, Dr.; Norzilah, Abdul Halif, Dr.; Nur Hidayah, Ahmad Zaidi; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2013)
      The ability of pomelo peel (PP) as natural adsorbent to remove Cu (II) ions from aqueous solution was investigated. The influence of solution pH, contact time and temperature were evaluated. Cu (II) removal increased as ...

    • Mechanical properties of dissimilar welds between stainless steel and mild steel 

      Shamsul Baharin,  Jamaludin, Prof. Dr.; Mazlee, Mohd Noor, Dr.; Shahzan Kamarul, A. Kadir; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2013)
      Joining of stainless steel type 304 to mild steel was carried out using a gas tungsten arc welding (GTAW). Samples were welded using stainless steel welding electrode: (AWS: E308l-16) and mild steel welding electrode: (AWS: ...

    • Novel of Binary Metal-Non Metal Material for Chair Flower Product (Novel AI - PP for Chair Flower Product) 

      Mohd Ichwan, Nasution, Prof. Madya Ir.; Kamarudin, Hussin, Brig. Jen. Dato' Prof. Dr.; Shamsul Baharin, Jamaludin, Prof. Dr.; Che Mohd Ruzaidi, Ghazali, Prof. Madya; Khairel Rafezi, Ahmad, Dr.; Chek Idrus, Omar; Mohamed Faisol, Mohamed Nor; Mohamad Safwan, Isa (Universiti Malaysia Perlis, 2009)
      Material for aluminium product usually made from aliminium scrap. Nowadays, the price of aluminium scrap is increased. The idea is how to minimize the cost of production via minimize the weight of the product without ...

    • Organic dye degradation with TiO2 catalyst/AAO template in the presence of H2O2 

      Alaba Oladeji, Araoyinbo; Mohd Nazree, Derman, Dr.; Azmi, Rahmat, Prof.; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2013)
      In this study, anodic aluminum oxide (AAO) fabricated from phosphoric acid electrolyte at ambient temperature was used as the porous template, while a sol gel procedure was used for the preparation of the TiO2 sol with the ...

    • Preparation and characterization of Co-HA powder using modified electroless method 

      Mohd Zaheruddin, Kasmuin; Sri Asliza, Md Amin; Azmi, Rahmat, Prof. Madya Dr.; Shamsul Baharin, Jamaludin, Prof. Dr.; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2014)
      C0-HA composite produced by simple electroless deposition method was studied. From the particle size analysis by Malvern particles analyzer its shows that 19% increment in average of the particle size powder increase after ...

    • Preparation and characterization of silica aerogel immobilized with cyanex 301 for extraction of Zn(II) 

      Mst. Noorzahan, Begum, Dr.; Md Fazlul, Bari, Dr.; Salmie Suhana, Che Abdullah; Khairel Rafezi, Ahmad, Dr.; Nasim, Ahmed, Dr. (Trans Tech Publications, 2013)
      A new solid phase extractant silica aerogel immobilized with Cyanex 301 {bis(2,4,4- trimethylpentyl) dithiophosphinic acid} (SAWC) was prepared via a sol- gel method and investigated for the extraction of Zn(II) from aqueous ...

    • Preparation of colossal magnetoresistance ploycrystalline via sol-gel technique: a short review 

      Mohd Zaki, Ruhiyuddin; Abdullah, Chik, Assoc. Prof. Dr.; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2013)
      This paper presents a short review of research work on the development of synthesizing the colossal magnetoresistance materials through sol-gel method. Although there are a lot number of methods available, sol-gel method ...