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Fulltext Al/b4c composites with 5 and 10 wt% reinforcement content prepared by powder metallurgy

Yusof Abdullah, Mohd Reusmaazran Yusof, Azali Muhammad, Nadira Kamarudin, Paulus, Wilfred Sylvester, Nurazila Mat Zali, et al.

Journal of Nuclear and Related Technologies, 2012;2012(1):42-47.
MyJurnal

The preparation, physical and mechanical properties of Al/B4C composites with 5 and 10 wt.% reinforcement content were investigated. In order to obtain the feedstock with a low powder loading, B4C mixtures containing fine powders were investigated to obtain the optimal particle packing. The experimental results indicated that the fine containing 5 and 10 wt.% particles are able to prepare the feedstock with a good flowability. The composites fabricated by powder metallurgy have low densities and homogeneous microstructures. Additionally there is no interface reaction observed between the reinforcement and matrix by XRD analysis. The hardness of Al/B4C composites prepared by powder metallurgy was high.

Matched MeSH terms: Hardness
Fulltext The influence of sulphuric acid concentration on hard anodising process on powder metallurgy Al-Mg

Mohd Nazree Derman, Mohd Nasuha Abd Halim, Shaiful Rizam Shamsudin

Journal of Nuclear and Related Technologies, 2009;2009(1):224-229.
MyJurnal

The hardcoat anodising process was done by using different concentration of H2SO4 from 0% to 20%. The 90 volt of anodising process was applied by using Al foil as cathode materials. The surface changes on PM Al-Mg resulted by hardcoat anodising was characterised by XRD measured. Surface hardness was measured by Micro-Vickers hardness machine. The experiment found different XRD pattern between anodised PM Al-Mg samples. The study was found by that the optimum value for H2SO4 concentration was 15 % H2SO4 and result 26 μm thickness, 5.07% of mass changes and HVN 105.4 hardness. The hardcoat anodising was affected to the XRD pattern for PM Al-Mg.

Matched MeSH terms: Hardness
Fulltext Improvement of mechanical properties and fatigue failure of Spot-Welded joint through Pneumatic Impact Treatment (PIT)

Ghazali, F.A., Salleh, Z., Hyie, K.M., Taib, Y.M., Nik Rozlin, N.M.

Pertanika Journal of Science & Technology, 2017;25(108):105-114.
MyJurnal

This study focuses on examining the influence of post weld impact treatment (PWIT) using Pneumatic Impact Treatment (PIT) for spot welded joint on mechanical properties and fatigue failure. PWIT is one of the methods for improving mechanical properties and fatigue strength of welded joints. One of the versatile techniques of PWIT used for this study is PIT. The material investigated in this study was carbon steel with welded single lap shear joint with the constant thickness of 1.2mm. All the welded samples were later performing the tensile shear test, hardness test, and fatigue test. The tensile shear test was conducted on the spot welded both treated and untreated samples using crosshead speed of 2 mm/ min, while hardness test was performed using 1kgf load via Vickers hardness indenter. Fatigue test was conducted using R=0.1 and frequency of 10 Hz. The effects of PIT on tensile-shear properties, hardness, and fatigue failure were evaluated. It was found that the implementation of PIT has increased tensile shear and hardness significantly and prolonged lifetime of spot welded joint.

Matched MeSH terms: Hardness; Hardness Tests
Fulltext Effect of speed and braking load on the wear phenomena of motorcycle

Dafit Feriyanto, Leman, A.M., Achmad Zainuri, Okariawan, I.D.K.

Journal of Occupational Safety and Health, 2015;12(2):49-56.
MyJurnal

In the development of current vehicle capabilities required an effective braking system, has a little wear, and
safety riding. The objective of the research is to determine wear and braking distance because of braking load and
speed motorcycle Honda supra X125 cc. This research used the speed of 50 km/h, 60 km/h, and 70 km/h. Braking load
used to be 4 kg, 5 kg, and 6 kg. The test was done by dynamic method and the research was done in two stages; testing
in the field and measuring brake wear in the lab using a profile projector. Testing the hardness of brake was done to
know hardness brake before and after testing due to the effect of wear, braking time, and braking distance.From testing
it was found that increasing of braking load, resulted in increasing wear. The smallest wear was 6 x 10-5 mm/sea at a
speed of 50 km/h, braking load of 4 kg, and braking time of 15.94 seconds. Increasing the speed resulted in increasing
braking distances with the smallest of braking distance was 55 meters at the breaking load of 6 kg, the speed of 50
km/h and braking time 9.93 seconds. The hardness of brake lining, increased after the brake lining wear testing. The
hardness before the test was 95.8 HRN and after the test was 100.4 HRN.

Matched MeSH terms: Hardness
Experimental data for effect of carbon black loading on tensile, hardness and rebound of magnetic iron filled natural rubber composites

Ismail R

Data Brief, 2019 Aug;25:104166.
PMID: 31516921 DOI: 10.1016/j.dib.2019.104166

Generally, a base isolator is made up of alternate layers of steel and rubber. The idea of adopting magnetoreological elastomers (MREs) in base isolator systems was introduced in the past few years in order to improve the efficiency of base isolator systems. The article provides information on the mechanical corresponding to different carbon black loading loadings of 20 parts per hundred rubber (pphr), 40 pphr and 60 pphr in natural rubber compound. The mechanical dataset described the data from tensile, hardness and rebound test.

Matched MeSH terms: Hardness
Fulltext Groundwater from fractured granite and metasedimentary rocks in the west coast of Peninsular Malaysia

Nasiman Sapari, Raja Zainariah Raja Azie, Hisyam Jusoh

Pertanika Journal of Science & Technology, 2012;20(2):371-379.
MyJurnal

Hard rock formations consisting of granite and metasedimentary rocks in Peninsular Malaysia, have beenconsidered to be of poor aquifers. The map of shows the area underlain by hard rock as having poorto moderate potential for groundwater production (

Matched MeSH terms: Hardness
Fulltext New recursive circular algorithm for listing all permutations

Sharmila Karim, Zurni Omar, Haslinda Ibrahim, Khairil Iskandar Othman, Mohamed Suleiman

Pertanika Journal of Science & Technology, 2014;22(1):25-33.
MyJurnal

Linear array of permutations is hard to be factorised. However, by using a starter set, the process of listing the permutations becomes easy. Once the starter sets are obtained, the circular and reverse of circular operations are easily employed to produce distinct permutations from each starter set. However, a problem arises when the equivalence starter sets generate similar permutations and, therefore, willneed to be discarded. In this paper, a new recursive strategy is proposed to generate starter sets that will not incur equivalence by circular operation. Computational advantages are presented that compare the results obtained by the new algorithm with those obtained using two other existing methods. The result indicates that the new algorithm is faster than the other two in time execution.

Matched MeSH terms: Hardness
Fulltext Enhancement of mechanical and corrosion resistance properties of electrodeposited Ni-P-TiC composite coatings

Fayyaz O, Khan A, Shakoor RA, Hasan A, Yusuf MM, Montemor MF, et al.

Sci Rep, 2021 Mar 05;11(1):5327.
PMID: 33674680 DOI: 10.1038/s41598-021-84716-6

In the present study, the effect of concentration of titanium carbide (TiC) particles on the structural, mechanical, and electrochemical properties of Ni-P composite coatings was investigated. Various amounts of TiC particles (0, 0.5, 1.0, 1.5, and 2.0 g L-1) were co-electrodeposited in the Ni-P matrix under optimized conditions and then characterized by employing various techniques. The structural analysis of prepared coatings indicates uniform, compact, and nodular structured coatings without any noticeable defects. Vickers microhardness and nanoindentation results demonstrate the increase in the hardness with an increasing amount of TiC particles attaining its terminal value (593HV100) at the concentration of 1.5 g L-1. Further increase in the concentration of TiC particles results in a decrease in hardness, which can be ascribed to their accumulation in the Ni-P matrix. The electrochemical results indicate the improvement in corrosion protection efficiency of coatings with an increasing amount of TiC particles reaching to ~ 92% at 2.0 g L-1, which can be ascribed to a reduction in the active area of the Ni-P matrix by the presence of inactive ceramic particles. The favorable structural, mechanical, and corrosion protection characteristics of Ni-P-TiC composite coatings suggest their potential applications in many industrial applications.

Matched MeSH terms: Hardness
Fulltext A study of microstructure and hardness on Fe-Co/SiC composites

Noraziana Parimin, Linus, Andy

Journal of Nuclear and Related Technologies, 2009;2009(1):65-70.
MyJurnal

This research was conducted to study the effect of reinforcement particles on iron-cobalt (FeCo) composites. The composition of silicon carbide (SiC) was varied from 0 to 20 wt%. The composite was fabricated via powder metallurgy (PM) method, which consists of mixing, compaction and sintering processes. The powder was mixed for 2 hours to obtain uniformity between SiC and Fe-Co matrix and compacted to a cylindrical shape at 250 MPa. Samples were sintered for 2 hours at 900 o C with 10 o C/minute heating rate in argon atmosphere. The influences of reinforcement particle on the sintered samples were characterized in terms of microstructure and hardness testing. The Fe-Co/20wt%SiC composites show highest hardness value.

Matched MeSH terms: Hardness; Hardness Tests
Fulltext Nanomechanical Behavior of Multi-Walled Carbon Nanotubes Particulate Reinforced Aluminum Nanocomposites Prepared by Ball Milling

Ostovan F, Matori KA, Toozandehjani M, Oskoueian A, Yusoff HM, Yunus R, et al.

Materials (Basel), 2016 Feb 26;9(3).
PMID: 28773261 DOI: 10.3390/ma9030140

The nanomechanical properties of carbon nanotubes particulate-reinforced aluminum matrix nanocomposites (Al-CNTs) have been characterized using nanoindentation. Bulk nanocomposite specimens containing 2 wt % multiwalled CNTs (MWCNTs) were synthesized by a combination of ball milling and powder metallurgy route. It has been tried to understand the correlation between microstructural evolution particularly carbon nanotubes (CNTs) dispersion during milling and mechanical properties of Al-2 wt % nanocomposites. Maximum enhancement of +23% and +44% has been found in Young's modulus and hardness respectively, owing to well homogenous dispersion of CNTs within the aluminum matrix at longer milling time.

Matched MeSH terms: Hardness
Fulltext Application of various mechanical treatments for meat tenderization

Mohamad Afifi Ismail, Gun Hean Chon, Mohammad Rashedi Ismail-Fitry

Journal of Advanced Research Design, 2018;45(1):43-51.
MyJurnal

Meat tenderness is an important quality attribute that influences consumer acceptance. The application of mechanical treatment by mean to reduce toughness of meat cuts has gained much interest recently, with an intention to make use the lower grade meat cuts. This review deliberates the function, mechanism and numerous types of mechanical work in meat tenderization. The mechanical work employs to make meat softer by loosening the muscle structure and disrupting muscle cell. Previous studies have thoroughly examined the use of mechanical treatment (such as massaging, tumbling, and grinding) as an effective meat tenderization technique. Besides that, current research on newly emerging processing technology such as highpressure process (HPP) also shows potential to be explored. The application of mechanical work has shown impressive outcomes by reducing the shear force value that represents hardness of meat. The present paper also described the physical, biochemical and the structural changes of the meat. Finally, the improvements in the meat tenderness by using various type of mechanical work are presented in this paper.

Matched MeSH terms: Hardness
Effect of phosphite loading on the mechanical and fire properties of palm-based polyurethane

Khairiah Badri, Amamer Musbah Redwan

Sains Malaysiana, 2010;39.

Fire-retarding polyurethane (PU) composite was produced by adding 2,4-ditert-butylphenyl phosphite (FR) to palm-based monoester resin with loading percentage of 0, 2, 4, and 6 wt%. The Shore D hardness index increased marginally with increasing FR content. However, the impact and flexural strengths decreased with increasing FR loading attributed to the weak interfacial bonding between FR and PU matrix. The fire test indicated lowering of burning rate (from 5.30 mm.s-1 to 2.80 mm.s-1) as the loading percentage of FR increased. The combustion enthalpy of the composites also decreased with higher loading percentage of FR.

Matched MeSH terms: Hardness
Effect of electron beam irradiation on natural rubber/linear low density polyethylene blends with m-phenylenebismaleimide

Nor Hayati Muhammad, Ibrahim Abdullah, Dahlan Mohd

Sains Malaysiana, 2011;40:1179-1186.

The effects of HVA-2 on radiation-induced cross-linkings in 60/40 natural rubber/ linear low density polyethylene (NR/LLDPE) blends was studied. NR/LLDPE was irradiated by using a 3.0 MeV electron beam machine with doses ranging from 0 to 250 kGy. Results showed that under the irradiation employed, the blends NR/LLDPE were cross-linked by the electron beam irradiation. The presence of HVA-2 in the blends caused the optimum dose to decrease and the blends to exhibit higher tensile properties. Further, within the dose range studied, the degradation caused by electron beam irradiation was found to be minimal. The optimized processing conditions were 120oC, 50 rpm rotor speed and 13 min processing time. The gel content, tensile strength, elongation at break, hardness and impact test studies were used to follow the irradiation-induced cross-linkings in the blend. For blends of 60/40 NR/LLDPE with 2.0 phr HVA-2, the optimum tensile strength and dose, were 19 MPa and 100 kGy, respectively. Blends of 60/40 NR/LLDPE without HVA-2, the optimum tensile strength and dose were 17.2 MPa and 200 kGy, respectively.

Matched MeSH terms: Hardness
Case study on deformation control of upper-soft and lower-hard large span tunnel station using combined control technology and monitoring demonstration

Yanliang Shang, Shouji Du, Biao Shao, Tongyin Han

Sains Malaysiana, 2017;46:2091-2099.

A large number of shallow buried tunnels are built in the city nowadays and the special strata such as large upper-soft and lower-hard ground often encountered. Deformation control of strata is the focus issue related to the construction safety. Based on Dalian metro Hing Street station with the classical geological condition of upper-soft and lower-hard ground, this paper fully used a combined control method including six different support measures to control the deformation of surrounding rock. 3D finite element model was setup to analyze the construction effect of combined control measures and the monitoring in-site was carried out to verify the deformation control effect of combined control method. It shows that the maximum surface subsidence value is gradually reduced with the support measures gradually increasing. In the case of various supports the maximum sedimentation value is 2.67 cm, which is 42. 1% lower than that of not using control method and the control effect is obvious. In addition, it can be seen that the two-layer initial support and additional large arch foot have the best effect on controlling the ground surface settlement with reduction of 11.7% and 20.2%, respectively. The research results can provide practical experience for the construction of such tunnels, and guide the design and construction of the tunnel in the future.

Matched MeSH terms: Hardness
Effect of grain size and grain content on the hardness and drillability of rock

Mou Y, Yingfeng-Meng, Gao L, Lin H, Yufei-Li

Sains Malaysiana, 2014;43:81-87.

It is well-known that the characteristics of hardness and drillability are influenced by microstructure of rock. In this study, rock properties were analyzed on grain size and grain content. Coarse-grain and fine-grain sandstones were tested under successive indentation condition. Eighteen groups of sandstone and shale were employed for the drillability test. Indentation tests results showed that grain size influenced the low point of residual hardness, the crushing depth and volume and grain content influenced the peak point of hardness. The drillability values of shale increased with increasing contents of clay and quartz. Meanwhile, drillability values of sandstone increased with increasing content of quartz, but decreased with increasing content of clay. Therefore, these preliminary studies show great potential applications for selecting suitable bit type and formulating drilling program as a function of rock microstructure and crushing rock method for bit in the oil drilling.

Matched MeSH terms: Hardness
Fulltext Effect of MgO Addition on the Mechanical and Dynamic Properties of Zirconia Toughened Alumina (ZTA) Ceramics

Arab A, Sktani ZDI, Zhou Q, Ahmad ZA, Chen P

Materials (Basel), 2019 Jul 31;12(15).
PMID: 31370216 DOI: 10.3390/ma12152440

Zirconia toughened alumina (ZTA) is a promising advanced ceramic material for a wide range of applications that are subjected to dynamic loading. Therefore, the investigation of dynamic compressive strength, fracture toughness and hardness is essential for ZTA ceramics. However, the relationship between these mechanical properties in ZTA has not yet been established. An example of this relationship is demonstrated using ZTA samples added with MgO prepared through conventional sintering. The microstructure and mechanical properties of ZTA composites were characterized. The hardness of ZTA composites increased for ≤0.7 wt.% MgO due to the pinning effect of MgO and decrease of the porosity in the microstructure. Oppositely, the fracture toughness of ZTA composites continuously decreased due to the size reduction of Al2O3 grains. This is the main reason of deteriorate of dynamic compressive strength more than 0.2 wt.% of MgO addition. Therefore, the SHPB test shows the improvement of the dynamic compressive strength only up to a tiny amount (0.2 wt.% of MgO addition) into ZTA ceramics.

Matched MeSH terms: Hardness
Fulltext Antioxidative and Quality Properties of Full-Fat Date Seeds Brew as Influenced by the Roasting Conditions

Fikry M, Yusof YA, M Al-Awaadh A, Abdul Rahman R, Chin NL, Ghazali HM

Antioxidants (Basel), 2019 Jul 18;8(7).
PMID: 31323854 DOI: 10.3390/antiox8070226

Full-fat roasted date seeds are considered an excellent source of antioxidants which can treat many diseases. The specific objectives were to investigate the effect of roasting temperature and time on the hardness of whole seeds, moisture content of the roasted date seeds powder, DPPH radical scavenging activity, total phenolic contents, extraction yield, pH, browning index and sensory properties of the brew prepared from the full-fat roasted date seeds and to construct descriptive models that could describe this effect. Date seeds were roasted at three temperatures (160, 180 and 200 °C) for different period of times (10, 20 and 30 min) using a natural conventional oven; then grinded and next brewed. Hardness of whole seeds, moisture content of the seeds powder, DPPH radical scavenging activity and total phenolic contents, extraction yield, pH and browning index and sensory properties of the brew were significantly affected by the roasting conditions. The statistical results indicated that the proposed model could adequately describe the measured properties. Strong correlations have been found among the properties of the brew as well. The producers of the date seeds brew can utilize these results for controlling the roasting process.

Matched MeSH terms: Hardness
Influence of Weather on Hardness and Surface Roughness of Maxillofacial Elastomeric Materials

Mousa MA

J Contemp Dent Pract, 2020 Jun 01;21(6):678-682.
PMID: 33025938

AIMS: The purpose of this study was to assess the influence of hot and dry weather on the hardness and surface roughness of four different maxillofacial silicone elastomeric materials (MFSEM) including two room-temperature vulcanized (RTV) and two high-temperature vulcanized (HTV) materials.
MATERIALS AND METHODS: Eighty test specimens were fabricated according to the manufacturer's instructions into rectangular test specimens. The hardness and surface roughness were tested, after 6 months of exposure to natural hot and dry weather. The hardness was measured through the International Rubber Hardness Degree (IRHD) scale using an automated hardness tester. The surface roughness was measured using a novel 3D optical noncontact technique using a combination of a light sectioning microscope and a computer vision system. Statistical Package for Social Sciences software SPSS/version 24 was used for analysis and a comparison between two independent variables was done using an independent t test, while more than two variables were analyzed, F test (ANOVA) to be used followed by a post hoc test to determine the level of significance between every two groups.
RESULTS: The hot and dry weather statistically influenced the hardness and surface roughness of MFSEM. Cosmesil M-511 showed the least hardness in test groups while A-2000 showed the hardest material (p < 0.05). A-2000 showed significant changes from rough in case of nonweathered to become smoother in weather followed by A-2186 (p < 0.05). Cosmesil M-511 showed the roughest material.
CONCLUSION: Cosmesil M-511 showed the least hard MFSEM after outdoor weathering while A-2000, the highest and least material showed hardness and surface roughness, respectively.
CLINICAL IMPLICATION: A-2000 had a high IRHD scale hardness. This makes this material more suitable for the replacement of ear and nose defects. Cosmesil M-511 is soft and easily adaptable material that makes the material more appropriate for the replacement of small facial defect with undercut area to be easily inserted and removed. Whilst A-2000 is smoother and finer in test specimens after weathering, Cosmesil M-511 became rougher after weathering.

Matched MeSH terms: Hardness
High mechanical strength and broad optical absorption in underexplored group IV nitride chalcogenides

Chang YHR

Chem Commun (Camb), 2020 Sep 17;56(74):10962-10965.
PMID: 32789397 DOI: 10.1039/d0cc04123h

While lab-scale synthesis of trigonal-Zr2N2S, hexagonal-Zr2N2S and hexagonal-Zr2N2Se has been reported, meaningful data on the photophysical properties of IV-nitride chalcogenides in general are scarcely available. The first-principles calculations and genetic algorithm modeling in our work reveal the existence of remarkably stable, indirect gap trigonal-Zr2N2Se and trigonal-Hf2N2Se phases, which progress to direct gap, monoclinic materials in monolayer form. These structures display the desired optoelectronic properties, such as exceptionally high visible-UV absorption spectra (105-106 cm-1) and exciton binding energy below 0.02 eV. Strong hybridization between the Zr-d, N-p and Se-p orbitals is accounted for by the polysilicon comparable Vickers hardness (10.64-12.77 GPa), while retaining ductile nature.

Matched MeSH terms: Hardness
Fulltext Development and physical analysis of high fiber bread incorporated with cocoa (Theobroma cacao sp.) pod husk powder

Amir, I.Z., Hanida, H.S., Syafiq, A.

International Food Research Journal, 2013;20(3):1301-1305.
MyJurnal

The main approach of this study is to develop high fiber bread by utilizing the cocoa-by products, namely cocoa pod husk which is incorporated into whole meal bread. The cocoa pod husk can be classified as one of the source of high fiber. The cocoa pod husk was dried and milled in order to produce the cocoa pod husk powder (CPHP). There were five different percentages of CPHP level incorporated into the high fiber bread which were formulation A (0% CPHP), formulation B (5% CPHP), formulation C (10% CPHP), formulation D (15% CPHP) and formulation E (20% CPHP). All of the samples undergone physical analysis and sensory evaluation. The incorporation of CPHP give significant effects towards bread volume and hardness attribute where the bread became denser and harder in texture as compared to the control. The color of bread crumb and crust was also changed to darker color. For the overall acceptance, formulation B has the highest mean score among the composite breads (formulation B to E) studied.

Matched MeSH terms: Hardness

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