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In recent years, it has been shown that high pressurized solidification has been impeding cooling rate measurement in semisolid forging of aluminum alloys. This has restricted the establishment of ...

Instant coffee powder is a downstream product of coffee processing. The purpose of this research was to study the effect of fillers on the physical, chemical, and sensory properties of instant coffee powder. This study was used Robusta coffee which was roasted at medium to dark level. The fillers used were maltodextrin and dextrin. The instant coffee powder was made by crystallization and drying techniques with a cabinet dryer. The results showed that the difference between the two fillers did not affect the physical properties of instant coffee powder such as yield, pH, solubility, brightness (L*), and yellowishness (b*). Meanwhile, the chemical properties of water content showed a significant difference between the two treatments. The sensory properties of the two treatments have a description of the color tends to be bright, slightly brown, the taste was quite bitter, slightly sweet, quite sour, the aftertaste was medium sour, the aftertaste was low in smoke, the aftertaste was quite detectable, the aroma of coffee was medium, slightly sweet, and slightly caramel-flavored. The instant coffee powder has the potential to be developed as a coffee flavoring preparation for food products.

In this study, the influence of different contents of Ba additions on the microstructure evolution, phase reaction characteristic, and mechanical property of Al–Mg–Si alloy was investigated. Microstructural characterization was conducted by means of scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) facility, X-ray diffraction (XRD), and electron backscatter diffraction (EBSD). The mechanical property was examined using hardness test. The results revealed that cubic primary Mg2Si crystals shaped by {100} facets with an average particle size of 35 μm were successfully fabricated through the addition of 0.2 wt. % Ba element to Al–Mg–Si melts. For the first time, it is revealed that the Al4Ba compound can act as the nuclei for the primary Mg2Si during solidification, which leads to the refining of the primary Mg2Si particle size extensively. Furthermore, the formation of Al2Si2Ba and AlSiBa intermetallic compounds (IMCs) are liable for the Mg2Si particle refinement; hence, the hardness of the alloy increased from 60.21 to 67.83 Hv. Besides, thermal analysis showed that the nucleation temperatures of the primary Mg2Si phase increased with the addition of Ba. Ba additions perform a substantial role in determining the shapes of primary Mg2Si crystals, which can be altered from coarse dendritic structure (0 wt. %) to crystals with a combination of eight {111} and four {100} facets (0.08 wt. %), then to truncated cube (0.1 wt. %), and finally to a cube fully bounded by {100} facets (0.2 wt. %) with increasing Ba concentrations. This study revealed that the growth process of the cubic primary Mg2Si is due to the absorption and poisoning effect of Ba atoms, which leads to the fading of the growth rates of {100} faces of primary Mg2Si and as a result the {100} faces are exposed. Furthermore, in the modified alloy, the skeleton-type growth process of the cubic primary Mg2Si was found, in which growth steps with some hillocks were detected.

Manajemen bengkel/laboratorium di Sekolah Menengah Kejuruan secara fungsinya belum dimanfaatkan secara maksimal, hanya terpaku sebatas penggunaan tempat praktikum siswa dan belum banyak dimanfaatkan oleh para pengelola dalam meningkatkan kulitas bengkel/laboratorium di sekolah. Manajemen fasilitas bengkel/laboratorium sangat penting dalam peningkatan kulitas guru dan siswa dalam memenuhi mutu pembelajaran dan hasil dari kulitas pembelajaran guna meningkatkan kualitas lulusan. Sekolah Menengah Kejuruan pada dasarnya tidak hanya diperuntukkan untuk memahami penguasaan teori saja, namun harus juga memiliki kompetensi teori dan praktik dalam memenuhi kriteria unjuk kerja. Dengan demikian guru memiliki peranan sangat penting dalam penguasaan dan pengeloaan bengkel. Pelatihan Manajemen Bengkel/Laboratorium Bagi Guru Mata Pelajaran Praktik di SMK Wilayah Kabupaten Pandeglang dilakukan untuk meningkatkan manajemen guru dalam melakukan pengelolaan fasilitas bengkel/laboratorium di SMK.

One of the high potential material, lanthanum zirconate (LZ) is deposited on superalloy 625 due to its excellent phase stability, low thermal conductivity as well as the high melting point. However, microstructural defects were detected due to lamellar structure behaviour exhibited from the plasma-sprayed coating techniques. This paper investigated the effect of surface modification on LZ thermal barrier coating (TBC) by using laser glazing method. The double ceramic layer (DCL) TBCs are composed of NiCoCrAlYTa bond coating formed via the HVOF process while 8YSZ ceramic top coat and La2Zr2O7 as the third layer were produced by utilizing the APS technique. Nd:YAG pulsed laser has been used to modify the surface layer of plasma-sprayed LZ coatings. The microstructural morphologies of both as-sprayed and laser glazed samples were investigated using Scanning Electron Microscopy (SEM). The phases of the coatings were analysed with X-ray Diffractometry (XRD). The results showed that the laser glazing process reduced surface roughness attributed to the sealing of porosities and other structural defects of the coating. Finally, the impacts of laser energy input and laser distance on the characterization of the glazed layer are discussed.

In this paper, two coating techniques, the high velocity oxy-fuel (HVOF) and air plasma spray (APS) techniques, were used to deposit a bond coat of NiCoCrAlYTa on the Inconel 625 substrate, followed by applying a topcoat of yttria-stabilized zirconia (YSZ). The samples were preoxidized in an argon-controlled furnace at a temperature of 1000 °C for 12 and 24 h to characterize the microstructure of a thermally grown oxide (TGO) using the two coating techniques. The most suitable preoxidized samples were further tested for isothermal oxidation at 1000 °C for up to 120 h, and a hot corrosion test was performed at 1000 °C for up to 52 h or until spalling occurred. As-sprayed and oxidized samples prepared with different coating techniques were evaluated in terms of their microstructure using different characterization methods, such as field emission scanning electron microscopy (FESEM), variable pressure scanning electron microscopy (VPSEM), energy dispersive X-ray spectroscopy (EDS) equipped with energy dispersive X-ray and X-ray diffraction (XRD) analyses. In addition, the mechanical properties of these samples were evaluated using adhesion tests. The results show that the YSZ/NiCoCrAlYTa coating applied with the HVOF technique forms a more thin and continuous layer of TGO than that obtained when applying a YSZ/NiCoCrAlYTa coating using the APS technique, indicating that a severe brittle oxidation interface exists between the two layers. The results also indicate that the mechanical strength obtained from the adhesion test of the coated samples is observably affected by the oxidation behaviors obtained with the different deposition techniques chosen.

This work is focused on developing zinc-doped hydroxyapatite—zeolite (ZnHA—Zeo) and polycaprolactone (PCL) composite coatings on magnesium (Mg) substrate to improve the corrosion resistance and antimicrobial properties. Dip-coating technique was used to coat ZnHA—Zeo/PCL on the Mg substrate at room temperature. The samples were subjected to field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), energy dispersive X-ray spectroscopy (EDX) and antimicrobial potential. Results demonstrated that composite coatings consist of HA, scholzite, zeolite, and PCL phases. EDX spectra indicated the presence of calcium (Ca), silicon (Si), aluminum (Al), zinc (Zn), phosphorus (P) and oxygen (O). The composite surface appeared in spherical-like microstructure on coating with thickness ranging 226–260 μm. Zinc-doped HA—Zeo composite coating had a high corrosion resistance and provided sufficient protection to the Mg surface against galvanic corrosion. Doped ZnHA—Zeo coating samples exhibited superior disc inhibition by confirming antimicrobial activity against the E. coli as compared to HA—Zeo sample. Altogether these results showed that the ZnHA—Zeo coatings not only improved the corrosion resistance, but also enhanced the antimicrobial property and hence they can be used as suitable candidates for implant applications.

Cobalt chromium alloys constitutes the base of one important group of biometallic with excellent mechanical properties. However, due to its non-bioactive and non-antimicrobial surface, cobalt chromium alloys are vulnerable to wear corrosive attack and bacterial infection. Hence, coating cobalt chromium alloys surface with superior biomaterials is the best proven techniques. In this work, nanostructure silver adopted titanium dioxide coating was deposited on cobalt chromium alloys using air plasma spray (APS) and high velocity oxy-fuel (HVOF) techniques. Nanostructure TiO2–Ag coating demonstrated superior hardness, wear resistance and lower coefficient of friction when compared to bare CoCr alloys. Reduced plastic deformation detected by microstructural analysis indicate that the interference of nano-structure coating in metallic matrix help lower the wear rate of the sample. Meanwhile, low porosity of the coating produced by HVOF technique shown a better wear resistance result than APS technique. Keywords: Cobalt–chromium alloy, Nanostructure TiO2–Ag coating, Thermal spray coating method, Surface properties, Wear performance

The high cost of health services in low-income countries has caused them to produce implants and medical devices at low cost. This research highlights a preliminary study of the design concept, mould design, and fabrication of horizontal type centrifugal casting machines for the manufacture of dynamic compression plates materials. Normally, dynamic compression plate is produced from materials such as 316L stainless steel, cobalt, and titanium alloys. In this work, aluminium-silicon alloy was used in this preliminary study. Aluminium-silicon alloy was melted at a temperature of 730 °C and poured into a mould with a rotational speed of 1500 rpm. Tensile, hardness and microstructure investigation were carried out to discern the mechanical properties of the cast product from the horizontal type centrifugal casting machine. Results showed the measured value of tensile strength is not significantly different in the two zones of cast pipe, the butt zone of fall of molten metal (specimen A) was 147 MPa, and the butt-end zone (specimen B) was 142 MPa. The hardness value for the as-cast pipe obtained from the outside, middle, and inside, was 104.0, 92.9, and 80.3 HV, respectively. Evaluation of microporosity in fractures (from tensile test) results from horizontal type centrifugal castings showed a small distribution. Meanwhile, the calculation of the contour hole processing time for DCP with eight holes is 38 minutes per implant.

Soils of the tropics are highly weathered, acidic, and low in phosphorus (P) because of high contents of Al and Fe. Satisfactory P supply is essential to ensure optimum soil and crop productivity. Thus, there is a need for amending soils with zeolite to improve availability of P in acid soils as this mineral can fix Fe and Al instead of P. This study was undertaken to determine the transformations of P fertilizers in acid soils following application of Clinoptilolite zeolite (CZ) in laboratory (incubation) and pot trials. An acid soil was incubated with a recommended fertilization rate and a reduced amount of the existing recommended fertilization by 25% but substituting this reduction with an equivalent amount of CZ. Triple superphosphate (TSP), Egypt Rock phosphate (ERP), and Christmas Island Rock phosphate (CIRP) were used as P sources. Selected soil chemical properties, inorganic P fractions, available P, and total P of the native soil were determined before and after the laboratory and pot trials. Zea mays L. (test crop) plant dry matter production, P concentration, P uptake, and P use efficiency were also determined using standard procedures. Effects of the treatments with CZ compared to the recommended fertilization on P fixation were similar. In the laboratory study, the treatments with TSP showed lower dominance of Fe&ndash, P but more pronounced in Al&ndash, P, whereas for the RPs, Ca&ndash, P was dominant. In the pot study, Al&ndash, P, Ca&ndash, P, and Fe&ndash, P were rather pronounced in the treatments with TSP, ERP, and CIRP, respectively. There was a decrease in exchangeable Al and soil titratable acidity because of the ability of the CZ to increase soil pH. Although the availability of P was not significant with the inclusion of CZ in the incubation study, dry matter production, P concentration, P uptake, and P use efficiency in the pot trial were comparable with that of the existing/recommended fertilization, suggesting that the CZ is beneficial and could be used to reduce the P fertilizer requirement for Zea mays L. cultivation on acid soils. Regardless of type of P fertilizer, prevalence of the moderately labile P fractions (Al&ndash, P, Fe&ndash, P, and Ca&ndash, P) of the incubation and pot studies acted as slow-release P sources to contribute to long-term P release. Further studies on the potential of CZ to reduce fertilization and its effects on soil and crop productivity are essential. It is also important to determine the economic benefits of including CZ in Zea mays L. cultivation.

This work proposes a process for the fabrication of a silica aerogel (SA)–polyvinyl alcohol (PVA) core–shell structure using the fluidized bed method. First, nearly spherical hydrophobic SA particles with a diameter between 0.5 mm and 3.0 mm were prepared from rice husk ash via a sodium silicate route and ambient-pressure drying. Subsequently, a specific batch size of the SA particles was suspended in a heated air stream and sprayed with aqueous PVA using a bottom nozzle via the fluidized bed process. Coating of an individual SA particle is possible for large particle sizes and hydrophobization of the SA surface prevents penetration of PVA into its pores. The core–shell structured material showed a combination of high thermal insulation and good mechanical stability, rendering it suitable for use as filler in polymer resin, paints, and coatings. The core–shell structured material had an average density of 0.09 g cm−3 with well-preserved SA pores. The average shell volume fraction was 2.5%; the shell thickness varied below 50 μm, and was mostly approximately 20 ± 5 μm. Thermal analysis using transient plane hot-disk method and thermogravimetric analysis showed that the SA–PVA/core–shell structure exhibited lower thermal conductivity (0.035 W/mK) and higher thermal stability than uncoated SA.

This study investigates the effect of hot extrusion on microstructure and tensile properties of Al–15 wt %Mg2Si in-situ composite in unmodified and modified with (0.5–5.0 wt %) Gd addition. Furthermore, the morphology evolution of primary and eutectic Mg2Si particles in both unmodified and modified with 1.0 wt % Gd prepared by hot extrusion were examined in detail. The results showed that hot-extrusion process was efficient in transforming truncated octahedral primary and rod-like eutectic Mg2Si particles into near spherical and dot-like morphology, respectively in the modified alloy in which the particle fragmentation and thermal disintegration are the main mechanisms responsible for refinement/modification of primary and eutectic Mg2Si particles. It was suggested that the alteration of Mg2Si particles as well as fragmentation of Gd intermetallic compounds (IMCs) by hot extrusion played a significant role in strengthening the composite, i.e., the ultimate tensile strength (UTS) and elongation (%) values increased from ∼224.62 MPa to 3.75% in the 1.0 wt % modified composite to ∼245.83 MPa and 7.65% in the extruded modified one, respectively. In fact, a higher fracture stress can be established by fine near spherical primary Mg2Si particles through impeding dislocation motions and freeing stress concentrations. Furthermore, fragmentation of eutectic Mg2Si and Gd (IMCs) after extrusion lead to enhancement in ductility. This study demonstrated that combination of Gd addition and hot extrusion is a promising approach in modifying the microstructure and enhancing the tensile properties of in-situ Al-15%Mg2Si composite for industrial applications.

Floods can cause damage to homes. Some houses which have been significantly damaged, destroyed, or inhabitable. Inherently, victims should be given temporary or permanent houses depending on the degree of damage to their houses. Therefore, an assessment of the degree of house damage must be carried out as a direction for the recovery effort. Thus, this research seeks to design a House Damage Assessment Form. This form has been established by having an in-depth interview with experts involved in MERCY Malaysia and a literature review of the evaluation forms used by other countries to assess the degree of house damage post-disaster.Keywords: flood; degree of house damage; damage assessment; post floodingeISSN 2398-4279 © 2018. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. https://doi.org/10.21834/ajqol.v3i11.121Â

This paper presents the results of experimental investigation on microstructure (size and morphology of eutectic Si), impact toughness and sliding wear properties of A356 Al-Si alloy and composites containing 10, 20 and 25 wt% of SiCp reinforcement produced by semisolid stirring technique. The results revealed that an increase in SiCp content leads to a reduction in the size of eutectic Si and also changes its morphology from plate-like to equiaxed. Furthermore, addition of 10 and 20 wt% silicon carbide reinforcement decreased the impact toughness by 6 and 18%, respectively. A356/25wt%SiCp composite registered the lowest impact toughness with reduction of 33% due to debonding and agglomeration of SiCp in the matrix. The sliding wear results showed that the wear resistance of the composites was significantly higher than that of the matrix alloy due to the increase in hardness as well as reduction in the size and also morphology transformation of eutectic silicon with increase in SiCp content. However, the existence of particle-porosity clustering with increasing the SiCp content to 25 wt% played a significant role in deteriorating the wear behavior of the composite.

Cities are naturally the center of attention when innovation and its geography are discussed. This paper seeks to elucidate the knowledge structures of the city innovation systems of Hong Kong and ...

A family of TiMn alloys having a comparable mechanical property to Ti6Al4V alloy was developed for biomedical applications. Addition of 3–4 wt% Mo was found to improve corrosion resistance of the alloys to a level of that of commercial pure Ti. The effect of Mo to the electrochemical parameters of the passive film was not yet clarified. This work evaluated the effect of Mo on pitting resistance of Ti6Mn4Mo (TiMnMo) alloy in Hanks’ solution using electrochemical techniques combined with SEM, AFM and XPS analyses. Electrochemically, the TiMnMo demonstrated a higher resistance to uniform corrosion than Ti6Mn (TiMn) with a re-passivation and restoration ability against pitting corrosion which was not observed on TiMn. The TiMnMo showed a non-diffusional corrosion characteristic due to a denser passive film than that of TiMn. The SEM and AFM observation revealed a more severe pitting formation on TiMn than on TiMnMo. The XPS analysis confirmed the presence of Mo and Mn oxides that reinforced the TiO2 matrix. The mechanism of the different passivation behaviors of the two alloys is described according to the point defect model that based on the balance of kinetics of the oxide layer growth and dissolution reactions.

The attainment of program outcomes for Solid Mechanic course offered to the Diploma in Civil Engineering students is evaluated. It was found that most of the students were incapable to demonstrate graduate attributes which applying knowledge of mathematics, natural science and engineering fundamentals and the ability to analyse engineering problems. Therefore, this study investigates the impact of physics and maths scores on the students’ performance of solid mechanics. Analysis of the previous results in physics and maths shows that there is a clear link between students’ fundamentals knowledge and the understanding of solid mechanics. Meanwhile, this study also aims to find out the root causes that led to the high failure rate of solid mechanics. A quantitative method was employed and a total of 180 students responded to the survey. Results of survey indicate that most of the students perceived that they had limited time to gain deep understanding of the course and they could not visualise the complex problems in solid mechanics. Majority of the students admitted that they did not manage to solve all questions during their final exam, and they were indeed not well prepared for it. Hence, the problem of high failure rate is feasible to be solved provided both lecturers and students making efforts in striving the success of this course. Keywords: Solid mechanics, Program outcomes, Failure rate, Problem solving, Applying knowledge

Chitosan nanoparticles (CNP) is a biopolymer with good antioxidant and blood compatibility. However, its haemostatic nature limits its use for blood-contacting applications. This study aimed to investigate the antioxidant and anti-thrombogenic properties of complexes composed of CNP and diallyl disulfide (DADS). The formation of intramolecular hydrogen bonds proved possible bonding between CNP and DADS to form complexes. XRD spectra showed the complexes were amorphous. The in-vitro study revealed that CNP/DADS exhibits 29.5% NO and 32.8% HP inhibition which proved its antioxidant properties. APTT and PT test results proved that CNP/DADS's antithrombogenic properties (P

Cobalt chrome molybdenum alloy is considered as one of the advanced materials which is widely gaining popularity in various engineering and medical applications. However, it is categorized as difficult to machine material due to its unique combination of properties which include high strength, toughness, wear resistance and low thermal conductivity. These properties tend to hinder the machinability of this alloy which results in rapid tool wear and shorter tool life. This paper presents a general review of the materials’ characteristics and properties together with their machinability assessment under various machining conditions. The trend of machining and future researches on cobalt-based and cobalt chromium molybdenum alloys are also discussed adequately.

In this study, different types of calcium-phosphate phases were coated on NaOH pre-treated pure magnesium. The coating was applied by electrodeposition method in order to provide higher corrosion resistance and improve biocompatibility for magnesium. Thickness, surface morphology and topography of the coatings were analyzed using optical, scanning electron and atomic-force microscopies, respectively. Composition and chemical bonding, crystalline structures and wettability of the coatings were characterized using energy-dispersive and attenuated total reflectance-Fourier transform infrared spectroscopies, grazing incidence X-ray diffraction and contact angle measurement, respectively. Degradation behavior of the coated specimens was also investigated by potentiodynamic polarization and immersion tests. The experiments proved the presence of a porous coating dominated by dicalcium-phosphate dehydrate on the specimens. It was also verified that the developed hydroxyapatite was crystallized by alkali post-treatment. Addition of supplemental fluoride to the coating electrolyte resulted in stable and highly crystallized structures of fluoridated hydroxyapatite. The coatings were found effective to improve biocompatibility combined with corrosion resistance of the specimens. Noticeably, the fluoride supplemented layer was efficient in lowering corrosion rate and increasing surface roughness of the specimens compared to hydroxyapatite and dicalcium-phosphate dehydrates layers.

Thermally grown oxide (TGO) plays important roles in thermal barrier coating system (TBC) for high temperature application such as in aircraft gas turbine engine blades (GTE). The TGO formed between the bond coat and topcoat interface can increase oxidation resistance to creep of GTE blades by minimizing oxygen diffusion into the metal substrate. In this research a NiCoCrAlYTa metallic bond coat was deposited on Inconel 625 substrate using two methods of deposition namely; high velocity oxy-fuel (HVOF) and atmospheric plasma spray (APS). After coating process, both types of samples underwent pre-oxidation in argon furnace for 12-24 hours at 1000 °C. Results showed that the TGO formation for samples in which the bond coat deposited via HVOF method produced much thinner and continuous TGO formation compared to APS deposition. This TGO characteristic is very useful to lengthen the lifetime of the metals substrate.

Waste is the outcome and activities of human beings. Its existence cannot be avoided so that it has to be managed well because unhygienic waste will cause environmental pollution. There are 126 cubic meters of waste per day transported to the garbage dump in Subulussalam with 42% of services of the total of 542 cubic meters per day. The objective of the research was to analyze Waste Management in Subulussalam, in 2017.The research used descriptive method by conducting in-depth interviews with 10 respondents. The data were obtained from the Sanitation Agency and gathered by using questionnaires, observation, and documentary study.The result of the research showed that organic waste (70%) was more than the waste from batteries (0.02%). The income and retribution obtained from waste management in Subulussalam increased to 25.2% each year. Facility and infrastructure indicated that waste transportation from the people’s homes used pushcarts (69.2%) since their houses were far from the main street and served by workers manually, while 30.7% were transported by garbage trucks.It is recommended that the City Administration promote the program which encourages waste recycling in order to decrease the waste volumes to the garbage dump and encourage compost making program, the stem of discriminating, collecting, transporting, and dumping waste by adding garbage trucks and workers. Keywords: Analysis, Waste Management, Landfill

The potential of binary Mg-Ca alloy as biodegradable material is considerable interest in implant application among researchers. This research was conducted to investigate the effect of different forging temperature and forging speed on the hardness, microstructure and corrosion rate of Mg-0.7%Ca. The experiment was established by preparing the alloy sample with 0.7%wt calcium content. The forging process was carried out under four different temperature variations of 140°C, 180°C, 220°C, and 260°C (±10°C) with two different speed;25 and 45 strokes per minute (spm). The samples microstructure was examined by optical microscope and scanning electron microscope (SEM) equipped with energy dispersive X-ray (EDX). The mechanical properties of the forged samples were measured in its hardness and plastic deformation ability along with samples cold-working percentage. The corrosion rate was determined by performing the electrochemical test in simulated body fluid. This research found that increases of forging temperature and forging speed provide a higher rate of recrystallization and Mg2Ca compound precipitation results in greater hardness, increase deformation and reduce the cold-working percentage. However, the investigated factors still led to a high corrosion rate compared to a previous study and consequently, reduce the feasibility of the alloy in implant application for biodegradable material.

The resurgence of local knowledge by using natural colourant in textile dyeing has gaining popularity due to the eco-friendly advantages and benefits. Textile dyeing process is keen as both art and science that has been practiced since human development. This paper aim to identify the process practiced in local textile dyeing with adaption of environmental catalysis. The methodology used in this study is reviewing the content by referring the previous study, text documentation and discussions. There are three (3) types of dyeing process identified in local textile production which are natural dyeing, naphthol dyeing and Remazol dyeing. The dyeing technology change with time and consumer demand by considering the economic purposes but neglecting the environment and vicinity safety. Therefore, the introduction towards environmental catalysis substances in the process of natural dyeing has led the eco-friendly chain process practices for local textile production, besides it is an initiative to create awareness and acknowledge about eco-friendly dyeing and local knowledge on textile dyeing process.

Natural dyeing is one of the indigenous pieces of knowledge that has been explored on its potential since prehistoric decade. The process and materials used revolves nature-friendly essential, which are safe to the environment in comparison to the chemical dyeing materials. Currently, the Adonidia Merillii or also known as betel nut tree, is only used as an ornamental tree such as in landscaping. However, it has potentials of being more than an ornament and can be utilized as dyes for local textile industries. Thus, this study focused on extracting dye from young Adonidia Merillii fruits husk. Traditional boiling method was applied to extract the natural colours from the fruits. Colour testing was conducted on four (4) types of fabrics which were rayon, Crepe de Chine (CDC), China Cotton and jacquard by using post-mordanting treatment. The mordants used were aqueous lime water, alum, and ashes. The colour on the textile samples was tested and evaluated via colour fastness properties. The tests conducted include exposing textile samples to artificial light, washing, rubbing, water and perspiration. Adonidia Merillii fruits husk have given hues of brown colour staining on the textiles, but the colour changed after the test, surprisingly on the artificial light exposure. The bright colour of the initial samples appeared to be less bright than those exposed to artificial light. The brightness of the samples was determined using blue scale grading. The findings from this experimental study may contribute to the palette colour of natural dyeing on textile and extended future research about the brightness change would be significant for the Malaysia local textile industries.

This study aims to analyze the effect of the stirrer model, stirring rotation (400, 500, 600 rpm), for 20 seconds, and pouring temperature (565, 570, and 5750C) on the microstructure and mechanical properties of the aluminum alloy ADC12. The methods of research are a) preparing material aluminum alloy ADC12, b) making molds, c) casting, d) making specimens for testing, e) micro structure testing and hardness testing, f) analyzing data using Microsoft excel applications. Results of the study show that the smallest grain size occurs in casting parameters: stirrer angle 00, 600 rpm rotation, and pouring temperature 5650C with a value of 27.715 µm. The biggest shape factor occurs in casting parameters: stirrer angle 00, rotation 600 rpm, and pouring temperature 5650C with a value 0.76. The highest hardness occurs in casting parameters: stirrer angle 00, rotation 600 rpm, and pouring temperature 5650C with a value 88.0 HB.

This research was conducted to evaluate the effectiveness of in-house design for horizontal true centrifugal casting machine of aluminium alloy. Various G (ranging from 50G to 100G) were investigated to produce cylinder tube with 30 mm in outer diameter, 15 mm in inner diameter and 100 mm in length. The machine was analyzed and calculated according to theoretical requirements to ensure the efficiency of casting performance. The cylinder mild steel mould with cantilever support was designed to receive the molten metal under the controlled speed of rotation. The melted aluminium casting alloy (LM6) at 750 °C was poured to preheated mould under differences centrifugal force until completed solidification via air cooling. The physical and hardness properties of the casting were characterized and analyzed after the casting process to verify the effect of G factors under the different centrifugal force. The results showed that the horizontal true centrifugal casting machine has potential to cast small dimensional cylinder tubes and exhibit a good physical dimension and hardness properties of the casting. Different rotation has shown a significant impact in physical dimension and mechanical property of cast tubes.

Nanoengineered materials are becoming a focus and being utilized in a wide range of applications, especially for water and wastewater treatments. The presences of these materials have brought various pronounced advantages and great deal of improvement to the environment and industries. Generally, nanoengineered materials can be categorized as carbon (organic) and noncarbon (inorganic) materials. Among carbon based materials are carbon nanotube and graphene, while noncarbon materials include metal and metals oxides. Various forms of nanomaterial have been developed such as nanowires, nanotubes and nanoparticles to showcase the advancement of the technology for water treatments. The chapter begins by outlining the merits and limitations of nanoengineered materials for wastewater treatment in numerous applications. The problems and challenges when utilizing nanoengineered materials as nanosorbents, nanometals/metals oxides, nanocarbon and in membrane process are described in details. Although there are many advantages, some challenges are still present, especially in membrane preparation involving nanomaterials. Agglomeration, low dispersity, easily oxidizes and leakages into contact water are some of the major limitations of nanoengineered materials. These issues ultimately will contribute to adverse effects imposed on human health and the ecosystem. Therefore, methods to overcome the inherent limitation of nanomaterials are presented here. Some of the potential solutions to the problems that are discussed in this chapter are encapsulation, grafting, crosslinking, coating, and composite membrane.

In this work, thermal degradation behavior of six local biomasses such as empty fruit bunch, rice husk, coconut pulp, saw dust, coconut shell, and sugarcane bagasse in Malaysia via pyrolysis was studied. The pyrolysis process was carried out from 25 to 700 °C under nitrogen atmosphere flowing at 150 ml/min via a thermogravimetric analyzer. The effect of biomass type was investigated on pyrolysis behavior. The particle size of biomass was in the range of 0.3 ≤ dp1 < 0.5 mm, whereas the heating rate was fixed at 80 °C/min. The thermogravimetric analysis (TGA) data were divided into three phases of degradation: moisture evolution, hemicellulose-cellulose degradation, and lignin degradation. The results showed that all biomass samples degraded between 25 and 170 °C in Phase I of moisture evolution. Among the biomass samples, coconut pulp achieved the highest mass loss (81.9%) in Phase II of hemicellulose-cellulose degradation. Lignin in all biomass samples gradually degraded from 450 to 700 °C in Phase III of lignin degradation. This study provides an important basis in understanding the intrinsic thermochemistry behind degradation reactions.

In this study, sol-gel dip-coating method was used to coat nano-hydroxyapatite on specimens of Ti-14Zr-13Nb alloy for orthopedic applications. The coated specimens were sintered at three different temperatures and time spans to evaluate the impact of sintering process on microstructure, mechanical, bio-corrosion, and bioactivity properties of the coating. Field-emission scanning electron microscopy and x-ray diffraction were used to analyze the coating microstructure. Coating adhesion and mechanical performance were also investigated by scratch testing. Besides, electrochemical corrosion and immersion tests were performed in simulated body fluid to examine the sintering effect on corrosion performance and bioactivity of the coatings, respectively. The evaluations of coated specimens displayed that sintering at elevated temperatures leads to higher surface integrity and improves crystallinity of the nano-hydroxyapatite to approximately 89% which brings about distinctively enhanced mechanical properties. Similarly, it improved the corrosion rate for about 17 times through sintering at 700 °C. Immersion test proved that the coating increased the bioactivity resulted from the dissolution of calcium phosphates into the corresponding environment. It is noticeable that sintering the dip-coated specimens in the nano-hydroxyapatite improves corrosion performance and maintains bioactive behaviors as well.

The mechanical properties and bio-corrosion behaviours of T4 solid solution heat-treated Mg–1.5Zn and Mg–9Zn alloys at 340°C under different heat treatment durations were investigated. In vitro corrosion behaviour of the heat-treated alloys immersed in simulated body fluid (SBF) were measured by electrochemical, hydrogen evolution and mass loss tests. Surface examination and analytical studies were carried out using optical and scanning electron microscopy, EDX, and X-ray diffractometry. The results show that the grains size of both the alloys apparently remained unchanged after T4 treatment. T4 treatment at 340°C for 6 h slightly increased the strength and elongation of Mg–1.5Zn alloy while it significantly improved the strength and elongation of the Mg–9Zn alloy because of the presence of residual Mg51Zn20 and Mg12Zn13 secondary phase at the grain boundary. The results of electrochemical tests show that the corrosion rate of both the alloys decrease with increasing treatment temperature. The result also...

Formation of thin and continuous layer of thermally grown oxide (TGO) in thermal barrier coating (TBC) are essential in order to avoid coating failure for high temperature applications. As-sprayed high velocity oxy-fuel (HVOF) bond coat can provide more uniform TGO layer in TBC system and much less oxide compare to air plasma spray (APS). In this paper, both APS and HVOF method are used to deposit NiCoCrAlYTa bond coat on Inconel 625 substrate followed by topcoat, YSZ deposition. Pre-oxidation process was done in normal oxygen furnace at 1000°C for 12 to 24 hours to study the characteristic of TGO formation via these two different methods. From the result obtained, it shows that HVOF method provide better TGO formation as compared to APS.

Dry sliding wear and friction behavior of cast A356 Al-Si alloy and composite containing 5wt. % ZrO2 particles were studied by means of a pins-on-disk apparatus over loads of 5N, 20N and a sliding speed of 0.628m/s. The experimental results showed that the composites exhibited a higher wear resistance in comparison to that of the unreinforced A356 alloy. The friction coefficient of tested materials increased with increasing applied load from 5 to 20 N. FESEM investigations revealed that the wear mechanism of the A356 matrix alloy changed from sever abrasive, adhesive wear into mild abrasion and adhesive wear with addition of 5wt. % ZrO2 reinforcement particles.

Successful business enterprises are to a great extent determined by strong sales and overall low operational cost; as a result, improving quality and reducing cost have been one of the important tasks for any business enterprise. These will help in achieving high quality products at reasonable price. Thus, due to the effectiveness ofSix Sigmain improving quality and reducing cost, it has become an excellent initiative that is gaining momentum in the business world. However, academics have conducted little research regarding this phenomenon, especially on it applicability in manufacturing industries. Therefore, this paper seeks the knowledge regarding howP-Diagram Model(Taguchi Method) can be applied in product development stage to achieve Design for Six Sigma (DFSS). The paper illuminates on “Process” as the basic unit for Six Sigma and how production process can be enhanced usingP-diagram. Following this understanding, the paper demonstrates how P-diagram can be applied in conceptualizing and developing product ideas that put into consideration users intent (User-centred design), reduce variations and thus, lower the risk of product failing.

é?á The purpose of this activity is to increase of people?óÔé¼Ôäós income through local food processing and its marketing by empowerment of communities. Participants of these activities include member of RT 05 RW IX, Kelurahan Krobokan, sub-district of West Semarang, Semarang City. The method are discussion, practice, and simulation. Implementation of activities is to encourage community to be entrepreneurs in increasing family incomes not only just relying on the income from the work as laborers or workers. Training activities of local food into a healthy diet has a positive response from family group in RT 05 RW IX, Kelurahan Krobokan, sub-district of West Semarang, Semarang City. ?é?á Keywords : family income, local food, entrepreneur, marketing

An unconsolidated undrained (UU) test is one type of triaxial compression tests based on the nature of loading and drainage conditions. In order to imitate the UU triaxial compression tests, a UU triaxial emulator with a graphical user interface (GUI) was developed. It has 5 deformation sensors (4 radial deformations and one vertical deformation) and one axial pressure sensor. In addition, other inputs of the emulator are the cell pressure, the height of sample, and the diameter of sample, which are provided by the user. The emulator also facilitates the analysis and storage of measurement data. Deformation data fed to the emulator were obtained from real measurements [H. Nawir, Viscous effects on yielding characteristics of sand in triaxial compression, Dissertation, Civil Eng. Dept., The University of Tokyo, 2002]. Using the measurement data, the stress vs radial strain, stress vs vertical strain, and Mohr-Coulomb circle curves were obtained and displayed by the emulator.

A binary Mg–6Zn biodegradable alloy was solution treated to evaluate the effects of resulting microstructure changes on the alloy's degradation rate and mechanisms in-vitro. The treatment was conducted at 350 °C for 6–48 h. Optical and scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction were used to analyze the as-cast and treated samples. Immersion and electrochemical tests were performed in simulated body fluid at 37 °C to assess the samples corrosion resistance. To confirm the results of the corrosion tests, pH measurement was carried out. It is found that over 24 h solution treatment dissolves intermetallic phases in matrix and produces an almost single phase microstructure. Decreasing the intermetallic phases results in lower cathode/anode region ratios and lowers corrosion rates. The results of the electrochemical and mass loss tests reveal that extended solution treatment improves the corrosion resistance of the alloy. The results also show that solution at 350 °C for 24 h enhances the corrosion resistance of the as-cast alloy more than 60%. In addition, decreasing intermetallic phases in the microstructure accompanied a lower pH rise reduced corrosion rate. Solution treatment is suggested as a corrosion improving process for the application of Mg–Zn alloys as biodegradable implant materials.

The influence of grain refinement—with the addition of 6 mass% Al–5Ti–B and 10 mass% Al–3Ti–B master alloys—on the temperature-based parameters of a commercial ADC12 die-casting alloy, modified with 0.04 mass% Sr, was investigated using computer-aided cooling curve thermal analysis. Results show that the addition of grain refiners caused the reaction area of the aluminium dendrite to shift up. With the addition of refiner reagents, the nucleation temperature and growth temperature for the evolution of the primary Al dendrite increased, while the recalescence temperature decreased. The dendrite coherency temperature (TDCP), time (tDCP), temperature (TN–TDCP), and time (tN–tDCP) interval for dendrite coherency and solid fraction at coherency point increased with the addition of Al–3Ti–B and Al–5Ti–B grain refiners. Nevertheless, the growth temperature of the eutectic aluminium–silicon phase remained at the modified range (563.5–565 °C) even after the addition of grain refiners. A grain-refined and modified structure was obtained after the addition of refiners, but no obvious mutual effect was found in terms of the coarsening of grain size or silicon demodification in the range of concentrations used in this study.

Hydroxyapatite bioactive coating was deposited on treated medical grade stainless steel 316L by electrophoretic deposition. Two independent variables including deposition voltage and time span were evaluated in order to investigate their effect on substrates’ corrosion potential and coating mass. After deposition, coated substrates were post-treated in a vacuum furnace at 800 \({^{\circ}}\)C. The experimental plan was based on a central composite design to create a precision of the mathematical models. The precision of mathematical model and relative parameters were evaluated by variance analysis. Optimum parameters value, considered as simultaneous minimum ion release and maximum coating mass, were predicted at the deposition voltage of 25.93 V and deposition time span of 159 s. The validity of the model generated by response surface methodology was evaluated by comparing the predicted and experimental results. In addition, close agreement between experimental and predicted results was observed.

This study aims to identify factors that influence the effectiveness of practical woodworking and determine the effectiveness of woodworking practical from the perspective of students of secondary vocational schools in the province of Aceh. Factors - factors studied were the workshop equipment, workshop environment. This study was designed to investigate the significant differences concerning factors woodworking practical effectiveness based on demographic factors. A total of 130 respondents were randomly selected from six vocational schools in the province of Aceh. The instrument consists of a set of questionnaire consisting of 49 items and distributed second level students. The results showed there is no significant difference between factors - factors woodworking practical effectiveness based on demographic factors except the income level of the parents and the parents’ workplace. This shows there is a significant effect of the four factors, the effectiveness of practical woodworking, accounting for 60.6% (R2 = 0.606) changes in the variance in effectiveness of hands-on woodworking, and between the two of these factors, the workshop environment is the factor that most influences the effectiveness of the practical work wood, contributing 43.3% (R2 = 0.433) of the variance in effectiveness of woodworking practical.

This study aims to identify factors that influence the effectiveness of practical woodworking and determine the effectiveness of practical woodworking from the perspective of students of secondary vocational schools in the province of Aceh. Factors studied were the workshop equipment, safety workshops, teaching skills, the workshop environment and student interest. This study was designed to investigate the significant differences concerning factors woodworking practical effectiveness based on demographic factors. A total of 130 respondents were randomly selected from six vocational schools in the province of Aceh. The instrument consists of a set of questionnaire consisting of 49 items and distributed to second level students. Data analysis using the two types of statistics, namely descriptive statistics and statistical inference. The results showed no significant difference between factors woodworking practical effectiveness based on demographic factors except the income level of parents and the parents of the respondents work. The results of multiple linear regression analysis stepwise method found that only four factors (environmental factors workshops, the students interest, the skills of teachers and workshop equipment factors) that affect the practical effectiveness of woodworking with the correlation coefficient R = 0.779. This shows there is a significant effect of the four factors, the effectiveness of practical woodworking, accounting for 60.6% (R2 = 0.606) changes in the variance in effectiveness of hands-on woodworking, and between the four factors, the workshop environment is the factor that most influences the effectiveness practical woodworking by contributing 43.3% (R2 = 0.433) of the variance in effectiveness of practical woodworking. The main implication of this study is the need for attention from the authorities to be more serious in efforts to improve the facilities and infrastructure in the workshop as well as security issues in practical workshops so that the effectiveness of the woodwork to be more robust.

Biocomposite has been widely used as plastics replacement for its biodegradability. However, the water absorptivity defeats its purpose as food packaging. The water absorption analysis for pineapple peel fiber (PAPF) was done according to ASTM D570-98 and it has been proven that the water content increases to 7.2% with the 50% content of PAPF in the bio-composite (50% PAPF). For that matter, hydrophobic coating was synthesized and applied on PAPF based bio-composite. The bio-composite was produced using Low Density Polyethylene (LDPE), pineapple peel fibre (PAPF), Linear LDPE grafted maleic anhydride (LLDPE-g-MA) as compatibilizer and Refined, Bleached Deodorized Olein (RBDOL) as plasticizer. The coating was synthesized by using polydimethylsiloxane (PDMS) and decamethylcyclopentasiloxane as hydrophobic component, silica nano-particles as nanostructured particles and non-organic solvent and non-ionic surfactant p-octyl polyethylene glycol phenyl ether as surfactant. The emulsion was homogenized and after that sprayed onto the surface of PAPF bio-composite and dried in the oven at 50-60˚C for 24 hours. Through the 100µm magnification using field emission scanning electron microscope (FESEM), the hydrophobic coating was proven to conform the Cassie-Baxter hydrophobic property. C-O bond from the PAPF disintegrates after the production of bio-composite from the Attenuated Total Reflectance Fourier Transform Infrared (ATR FTIR) spectrometry transmittance. The application of the coating onto the surface of PAPF bio-composite gave the surface hydrophobic property where the contact angle changes from 82.27±2.66˚ which is hydrophilic to 122.63±2.17˚ which is hydrophobic. The bio-composite with the highest PAPF content will also exhibit self-cleaning ability which makes it suitable for the usage of hydrophobic food packaging material.

The phase transformation sequence and solidification behaviour of an Al–13Mg–7Si–2Cu in-situ composite was examined using a combination of computer-aided cooling curve thermal analysis and interrupted quenching techniques. Five different phases were identified by analysing the derivative cooling curves, the X-ray diffraction profile, optical and scanning electron microscopy images and the corresponding energy dispersive spectroscopy. It has been found that the solidification of this alloy begins with primary Mg 2 Si precipitation and continues with the formation of eutectic Al–Mg 2 Si, followed by Al 5 FeSi and simultaneous precipitation of Al 5 Cu 2 Mg 8 Si 6 and Al 2 Cu complex intermetallic phases. The formation of the last three intermetallic compounds changes the solidification behaviour of these composites remarkably due to their complex eutectic formation reactions. The solidification of the alloy, calculated using the Factsage thermochemical analysis software, has demonstrated a good agreement with the experiments in terms of compound prediction, their weight fractions and reaction temperatures.

In this paper, an experimental investigation on shape replication and surface roughness of Al-12 wt% Si alloy casting produced by lost foam casting process was conducted. 5-step shape patterns incorporated with top and bottom gates were used. Four top gating systems with different pouring cup configurations namely single-middle, single-side, double and single-wide and a simple bottom gate design were investigated to appropriate filling to produces sound casting. Three sand vibration times of 1, 2 and 3 min were used for the moulding process. Molten metal was poured at five different temperatures of 660, 680, 700, 720 and 740 °C. Shape replication and surface roughness of the cast samples were analysed visually and by roughness tester, respectively. The results showed that pouring cup design has a significant effect on the replication and surface integrity of the castings. It was also found that single top-wide pouring cup as well as lower vibration time and higher pouring temperature provided castings with better shape replication and smoother surface finish with a surface roughness of 19–20 μm compared to 25–31 μm for castings produced with other cup configurations.

The effect of nanohydroxyapatite (HA) coating on corrosion resistance of 316L stainless steel was investigated. The stainless steel samples were pretreated in different volume concentrations of H2SO4 solution and were electrophoretically coated for various coating time spans and voltages. The coated samples were sintered in a vacuum furnace at different temperatures to modify the coating structure. The quality and morphology of the pretreated samples and the coating were microscopically characterised, and the compounds presented in the coatings were determined. The electrochemical corrosion test was performed in simulated body fluid to evaluate the coating impact on corrosion behaviour of the samples. The results showed that the deposition of nano-HA using moderate voltage and appropriate time span provides a smooth and almost cracked free coating, improving the corrosion resistance of the samples. Increasing the temperature of sintering modified the HA structure, resulting in the formation of denser coating and enhanced corrosion resistance of the samples.