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The Effect of the Operating Conditions on the Apparent Viscosity of Crude Palm Oil During Oil Clarification
Get PDFThis paper discusses the apparent viscosity of crude palm oil, using rotary viscometer, under different boundary conditions. It was experimentally shown that the apparent viscosity of palm oil drops with increasing of the shear rate and the temperature. However, the effect of temperature on the viscosity tends to fade at temperatures beyond 80 oC. A correlation between the apparent viscosity of crude palm oil and the operating conditions was developed. This correlation can be used in design of crude palm oil settlers and in determining the optimum operating conditions.Key Words: Crude palm oil, apparent viscosity, shear rate, modelling, separation 
Propanoyl(1Z)-N-(2,6-dimethylphenyl)-2-oxopropanehydrazonoate as inhibitor for corrosion of 6061 Al alloy15 % (v) SiC(p) composite in hydrochloric acid media
Get PDFABSTRACT: The corrosion inhibition effect of Propanoyl(1Z)-N-(2,6-dimethylphenyl)-2-oxopropanehydrazonoate (PDOH) in the corrosion of 6061 Aluminium alloy-15%(v) SiC(p) composite in 0.5 and 1M hydrochloric acid medium at four different temperatures (30, 40, 50 and 60 â°C) was investigated using potentio-static polarization (Tafel extrapolation and Linear polarization) and weight loss methods. The results obtained reveal that PDOH is an efficient corrosion inhibitor with around 96% inhibition efficiency within the range of temperature studied. Leftward and downward shifts in Tafel plots were observed with the addition of the inhibitor, indicating that PDOH inhibits the corrosion process effectively, and that it is a cathodic inhibitor. Corrosion rate increases and inhibition efficiency decreases with increase in temperature. Results obtained by Tafel extrapolation, linear polarization, and weight loss methods are in agreement. The adsorption of the inhibitor onto the surface of the 6061 Al alloy 15 % (v) SiC(p) composite is found to obey Temkins' adsorption isotherm that verifies the assumption of mono-layer adsorption on a uniform homogeneous composite surface with an interaction in the adsorption layer. The inhibition is therefore governed by the physisorption mechanism.ABSTRAK: Kesan perencatan kakisan Propanoyl(1Z)-N-(2,6-dimethylphenyl)-2-oxopropanehydrazonoate (PDOH) ke atas kakisan komposit aloi Al 6061-15%(v) SiC(p) dalam media asid hidroklorik 0.5 dan 1M pada suhu-suhu yang berbeza (30, 40, 50 dan 60â°C) telah dikaji menggunakan polarisasi statik-upaya (extrapolarisasi Tafel dan polarisasi Linear) dan kaedah kehilangan berat. Keputusan diperolehi menunjukkan PDOH adalah perencat yang efisien dengan 96 % keupayaan perencatan bagi julat suhu yag dikaji. Anjakan ke kiri dan ke bawah plot Tafel dapat dilihat dengan penambahan perencat, menunjukkan PDOH merencatkan proses kakisan dengan berkesan, dan ia adalah perencat katodik. Dengan peningkatan suhu, kadar kakisan meningkat dan keberkesanan perencatan menurun. Keputusan dari ekstrapolasi Tafel, polarisasi linear dan kehilangan berat.adalah saling bersetuju antara satu sama lain. Penjerapan perencat ke atas permukaan komposit aloi 6061 Al alloy 15 % (v) SiC(p) memenuhi penjerapan Temkins’ isoterma yang mengesahkan andaian penjerapan lapisan-mono ke atas permukaan komposit homogenus yang seragam melalui interaksi pada lapisan penjerapan. Perencatan dikawal oleh mekanisma fizijerapan
Nuclear Energy: An Ethical Use of Resources
Get PDFEnergy is the lifeblood of development, but its amount is finite. It can neither be created nor destroyed; but it can be converted from one form to another. The conversion changes the state of the resources and the change generally is not reversible. Nuclear energy steadily contributes about sixteen percent to global total electricity demand. Its application for electricity production is expected to increase due to dwindling natural resources, concern for greenhouse gaseous emission, and the limited capability of renewable energy and biofuels to be major energy resources. Nuclear energy, however, is plagued with ever presence public perception issues, some are real some are due to misperceptions. The trio of accidents: Three Mile Island, Chernobyl, and most recently, Fukushima, however has slightly dampened the prospect. Nuclear energy makes use of uranium, an element that has no peaceful applications other than to be used in nuclear power reactors to generate heat or neutrons, produce steam, and drive turbo-generators for electricity production. Other resources, such as oil, coal, and gas have multiplicity of uses that cannot be substituted by uranium. On that premise, this paper argues that the use of nuclear energy is an ethical choice. This choice overrides considerations such as waste, complexity, and safety that are often projected as reasons for avoiding it altogether. Those considerations are of scientific and engineering dimensions that mankind has to wrestle and overcome as the khalifah. In so doing, proper education and ethical use of knowledge become imperative. ABSTRAK: Tenaga adalah nadi pembangunan, tetapi jumlahnya terbatas. Ia tidak boleh dicipta atau dimusnahkan; tetapi ia boleh ditukar dari satu bentuk ke bentuk lain. Pertukaran bentuk ini mengubah keadaan sumber tenaga dan perubahan tersebut tidak boleh ditukarbalik. Tenaga nuklear menyumbang kira-kira enam belas peratus kepada jumlah permintaan elektrik global. Keperluan tenaga elektrik dijangka meningkat kerana pengurangan sumber asli, kebimbangan atas pelepasan gas rumah hijau, dan keupayaan biofuel dan tenaga boleh diperbaharui untuk menjadi sumber tenaga utama. Namun begitu, tenaga nuklear sentiasa dibelenggu oleh isu-isu persepsi umum, sebahagiannya benar dan sebahagian lagi disebabkan oleh salah anggap. Ketiga-tiga kemalangan nuklear: Three Mile Island, Chernobyl, dan baharu-baharu ini, Fukushima, bagaimanapun menjejaskan sedikit prospek berkenaan. Tenaga nuklear menggunakan uranium, suatu unsur yang tidak mempunyai sebarang kegunaan aman selain daripada digunakan dalam reaktor nuklear untuk menjana neutron atau haba, menghasilkan wap, dan memacu turbo-generator yang mengeluarkan elektrik. Sumber-sumber lain seperti minyak, arang batu dan gas mempunyai pelbagai kegunaan yang tidak boleh digantikan oleh uranium. Atas hujjah itu, rencana ini mengutarakan bahawa penggunaan tenaga nuklear adalah pilihan yang beretika. Pilihan ini mengatasi pertimbangan-pertimbangan seperti sisa, kerumitan teknologi, dan keselamatan yang sering ditonjolkan sebagai alasan untuk mengelakkan sama sekali kegunaan tenaga nuklear. Pertimbangan-pertimbangan tersebut adalah dalam dimensi saintifik dan kejuruteraan yang manusia, sebagai khalifah, perlu tangani dan atasi. Dalam berbuat demikian, pendidikan yang sempurna dan penggunaan pengetahuan yang beretika menjadi penting. Keywords-nuclear energy;greenhouse gas; renewable energy;ethical energy use; nuclear fuel; uranium; nuclear reactor
SURFACE EFFECT DUE TO INCIDENT PLANE SURFACE HORIZONTAL WAVES
Get PDFSurface effect due to incident plane surface horizontal waves through anisotropic elastic materials is studied. Mathematical formulation over the modeled earth's alluvial valley is transformed into integral equations. These integral equations altogether with the boundary condition and continuity equation are then solved numerically. The solution of these amplification effects over the half circular inhomogeneous alluvial valley are shown graphically.Keywords- surface effect; surface horizontal wave; inhomoge neous anisotropic material
Knowledge-Based Trajectory Error Pattern Method Applied to an Active Force Control Scheme
Get PDFThe active force control (AFC) method is known as a robust control scheme that dramatically enhances the performance of a robot arm particularly in compensating the disturbance effects. The main task of the AFC method is to estimate the inertia matrix in the feedback loop to provide the correct (motor) torque required to cancel out these disturbances. Several intelligent control schemes have already been introduced to enhance the estimation methods of acquiring the inertia matrix such as those using neural network, iterative learning and fuzzy logic. In this paper, we propose an alternative scheme called Knowledge-Based Trajectory Error Pattern Method (KBTEPM) to suppress the trajectory track error of the AFC scheme. The knowledge is developed from the trajectory track error characteristic based on the previous experimental results of the crude approximation method. It produces a unique, new and desirable error pattern when a trajectory command is forced. An experimental study was performed using simulation work on the AFC scheme with KBTEPM applied to a two-planar manipulator in which a set of rule-based algorithm is derived. A number of previous AFC schemes are also reviewed as benchmark. The simulation results show that the AFC-KBTEPM scheme successfully reduces the trajectory track error significantly even in the presence of the introduced disturbances.Key Words: Active force control, estimated inertia matrix, robot arm, trajectory error pattern, knowledge-based
Kinetics of Selective Catalytic Reduction of Nitric Oxide over Pt-Cu-Zsm5 Catalyst
Get PDFKinetics for the selective catalytic reduction (SCR) of nitric oxide (NO) using i-C4H10 as the reducing agent over Pt-Cu-ZSM5 has been investigated in the temperature range of 200 ?C – 450 oC. Langmuir-Hinshelwood-Hougen-Watson model was proposed for kinetics of the reaction and reaction parameters were evaluated. The heat of adsorption of NO was found to be considerably high, attributed to strong covalent bond between NO gas molecules and metal active sites. Using reaction parameters obtained from the experiment, the heterogeneous model could form a good correlation between experimental and simulated values of NO reduction. Key Words: Reaction kinetics, Selective catalytic reduction, NO reduction, Bimetallic catalyst, H-ZSM-5 zeolite
The Effect of Catalyst Support on the Decomposition of Methane to Hydrogen and Carbon
Get PDFDecomposition of methane into carbon and hydrogen over Cu/Ni supported catalysts was investigated. The catalytic activities and the lifetimes of the catalysts were studied. Cu/Ni supported on TiO2 showed high activity and long lifetime for the reaction. Transmission electron microscopy (TEM) studies revealed the relationship between the catalyst activity and the formation of the filamentous carbon over the catalyst after methane decomposition. While different types of filamentous carbon formed on the various Cu/Ni supported catalysts, an attractive carbon nanotubes was observed in the Cu/Ni supported on TiO2. Key Words: Methane decomposition, carbon nanotube, Cu/Ni supported catalysts
Esterification of Palmitic Acid with Methanol in the Presence of Macroporous Ion Exchange Resin as Catalyst
Get PDFThe esterification of palmitic acid with methanol was studied in a batch reactor using macro porous ion exchange resin Amberlyst 15 as a catalyst. Methyl palmitate was produced from the reaction between palmitic acid and methanol in the presence of catalyst. The effects of processing parameters, molar ratio of alcohol to acid M, (4-10), catalyst loading (0-10 g cat/liter), water inhibition (0-2 mol/liter), agitator speed (200-800 rpm) and reaction temperature (343-373K) were studied. The experimental kinetic data were correlated using homogenous as well as heterogeneous models (based on single as well as dual site mechanisms). The activation energy of the reaction was 11.552 kJ/mol for forward reaction whilst 5.464 kJ/mol for backward reaction. The experimental data fitted well with the simulated data obtained from the kinetic models. Keywords: Palmitic Acid, Methanol, Esterification, Ion Exchange Resin, Kinetics
Convection Heat Transfer Modeling of Ag Nanofluid Using Different Viscosity Theories
Get PDFABSTRACT: In this paper, the effects of adding nanoparticles (including Ag) to a fluid media for improving free convection heat transfer were analysed. The free convective heat transfer was assumed to be in laminar flow regime, and the corresponding calculations and solutions were all done by the integral method. Water, as a Newtonian fluid, was considered as the base and all relevant thermo physical properties of the nanofluids were considered to be unvarying. The calculations performed and the graphs generated showed that, in general, the addition of nanoparticles to the fluid media resulted in an increment or improvement of its heat transfer coefficient. With increase in the concentration of the nanoparticles, the heat transfer rate of the fluid also increased. The increment in heat transfer is also dependent on the nanoparticles’ thermal conductivity and the viscosity theory which was utilized in the calculations. In this study, four different theories were used to calculate the viscosities of the nanofluids. The effects of viscosity on the nanofluids’ thermal conductivity were apparent from the calculations which were performed for nanoparticle concentrations of 4% or less. ABSTRAK: Kajian ini menganalisis kesan penambahan nanopartikel Ag ke dalam media bendalir bagi tujuan pembaikkan pemindahan haba perolakan bebas. Perolakan bebas diandaikan berada di zon aliran laminar, di mana penyelesaian dan pengiraan telah dilakukan mengunakan kaedah kamilan. Air yang merupakan cecair Newtonian, dianggap sebagai asas dan sifat terma fizikal nanocecair dianggapkan tidak berubah. Mengikut pengiraan yang dilakukan dan graf yang diplotkan, umumnya penambahan nanopartikel kepada media bendalir menyebabkan peningkatan dan pengembangan pekali pemindahan haba. Kadar pemindahan haba meningkat dengan nanopartikel. Peningkatan pemindahan haba juga bergantung kepada pengalir haba nanopartikel dan teori kelikatan yang digunakan. Di dalam kajian ini, empat jenis teori telah digunakan bagi pengiraan kelikatan nanopartikel. Kesan kelikatan ke atas pengalir haba nanocecair sangat jelas kelihatan. Kesemua pengiraan telah dilakukan ke atas kepekatan kurang dari 4%.KEYWORDS: Ag nanofluid, heat transfer, natural convection
Singular Vector For A Shallow Water Model
Get PDFThe atmosphere is a chaotic dynamical system, small errors in the initial condition of an atmospheric model can lead to growing errors in the forecast. In order to reduce uncertainty in the forecast which occur from using only one initial condition from many possible initial conditions, more initial conditions are required. In practice, however, there is only single observation available for the initial condition. In this paper the singular vector has been applied to a single level shallow water model of the atmosphere to generate more initial conditions from one observation. ABSTRAK: Atmosfera ialah satu sistem dinamik yang huru-hara. Kesilapan kecil dalam kondisi awal model atmosfera boleh membawa kepada kesilapan yang semakin meningkat di dalam ramalan. Dalam usaha untuk mengurangkan ketidakpastian dalam ramalan yang berlaku dari menggunakan hanya satu kondisi awal, lebih banyak kondisi awal diperlukan. Secara praktikalnya, walau bagaimanapun, hanya terdapat satu pemerhatian yang sedia ada untuk kondisi awal. Kajian ini menerangkan vektor tunggal telah digunakan untuk model air cetek tahap atmosfera untuk menghasilkan lebih banyak kondisi awal dari satu pemerhatian.KEYWORDS: shallow water model; tangent linear model; adjoint linear model; singular vecto