Analysis Performance of Modified Tamanu Oil Enhanced with Additives as Potential Green Alternative in Metalworking Fluids

Mineral oils have long been utilized in industries as machining lubricants, which contributed to their depletion and hick in price and being non-biodegradable, harmful to the environment, and risk to health. Plant-based oil is more biodegradable, renewable, and environmentally friendly as a green alternative. However, in their crude state, plant-based oils are not up to par with the standard mineral oil used in lubrication in terms of high acidity, low-temperature performance, and oxidative instability. Further chemical modification and adding additives had to be made to improve the oil properties for industrial applications. This study focused on the performance of transesterification of Tamanu plant-based oil with Trimethylolpropane (MTO) and Pentaerythritol (MTOP), which mixed with 1% of Phosphonium Ionic Liquid (PIL) and 10% of Ammonium Ionic Liquid (AIL), producing a series of oil specimens; MTO, MTO+PIL1%, MTO+AIL%, MTOP, MTOP+PIL1%, and MTOP+AIL%. These samples are then subjected to physical analysis to determine the improvement of their properties in terms of kinematic viscosity and viscosity index as well as undergo a four-ball wear test to the determine the tribology aspects of the lubrication in terms of coefficient of frictions and wear scar diameter, in accordance with ASTM standard method. All the results were compared with commercial MWF which synthetic ester (SE) as reference oil. The result of viscosity index reveals that MTOP+PIL1% had the highest value of 178.76. MTO+AIL10% exhibits the lowest average COF (0.061) compared to other MTOs lubricants. Among MTOP, MTOP+PIL1% also had the lowest average COF which is 0.082. The addition of PIL1% to MTO and MTOP lowered the average scar diameter, 730.77 μm and 674.93μm respectively. With the enhanced properties from chemical modification and additives, Tamanu oil can be proposed as a green alternative for developing the metalworking fluid industries in the future

Analysis Performance of Modified Tamanu Oil Enhanced with Additives as Potential Green Alternative in Metalworking Fluids

Mineral oils have long been utilized in industries as machining lubricants, which contributed to their depletion and hick in price and being non-biodegradable, harmful to the environment, and risk to health. Plant-based oil is more biodegradable, renewable, and environmentally friendly as a green alternative. However, in their crude state, plant-based oils are not up to par with the standard mineral oil used in lubrication in terms of high acidity, low-temperature performance, and oxidative instability. Further chemical modification and adding additives had to be made to improve the oil properties for industrial applications. This study focused on the performance of transesterification of Tamanu plant-based oil with Trimethylolpropane (MTO) and Pentaerythritol (MTOP), which mixed with 1% of Phosphonium Ionic Liquid (PIL) and 10% of Ammonium Ionic Liquid (AIL), producing a series of oil specimens; MTO, MTO+PIL1%, MTO+AIL%, MTOP, MTOP+PIL1%, and MTOP+AIL%. These samples are then subjected to physical analysis to determine the improvement of their properties in terms of kinematic viscosity and viscosity index as well as undergo a four-ball wear test to the determine the tribology aspects of the lubrication in terms of coefficient of frictions and wear scar diameter, in accordance with ASTM standard method. All the results were compared with commercial MWF which synthetic ester (SE) as reference oil. The result of viscosity index reveals that MTOP+PIL1% had the highest value of 178.76. MTO+AIL10% exhibits the lowest average COF (0.061) compared to other MTOs lubricants. Among MTOP, MTOP+PIL1% also had the lowest average COF which is 0.082. The addition of PIL1% to MTO and MTOP lowered the average scar diameter, 730.77 μm and 674.93μm respectively. With the enhanced properties from chemical modification and additives, Tamanu oil can be proposed as a green alternative for developing the metalworking fluid industries in the future

Kajian pembelajaran alternatif kursus pengurusan pelabuhan melalui board game

Kaedah pengajaran tradisional iaitu secara syarahan dan pembelajaran melalui nota kuliah untuk kursus PMG3073 Pengurusan Pelabuhan perlu digantikan dengan idea pembelajaran aktif yang memberi tumpuan kepada menggalakkan penemuan pengetahuan oleh pelajar melalui alat dan kaedah yang lebih inovatif.Salah satu alat inovatif yang boleh digunakan ialah board game.Tumpuan kajian ini ialah membangunkan model aliran proses hasil daripada pemerhatian aktiviti yang berlaku di pelabuhan, uji main board game yang berada di pasaran dan semakan silibus kursus PMG3073 Pengurusan Pelabuhan.Hasil daripada model yang dibangunkan sebuah prototaip board game dihasilkan dengan menyesuaikan mekanik-mekanik permainan untuk proses yang diwakilkan. Uji main telah dilakukan untuk memastikan board game mencangkupi kandungan silibus kursus. Secara keseluruhannya, kajian ini mencadangkan penggunaan board game di dalam kuliah dapat membantu meningkatkan pemahaman pelajar

Nonlinear characterisation of reconfigurable antennas

The lack of references on nonlinearity issue faced in reconfigurable antennas has motivated the work described in this thesis. The nonlinear behaviour is caused by active switches introduced on the radiating structure of the reconfigurable antennas. Depending on the type of active switches deployed on the antenna, the nonlinearity could be severe, which could have serious implications for antenna operation. Thus, the issue of nonlinearity in reconfigurable antennas should not be ignored and nonlinearity measurements should be performed to ensure the nonlinear performance is within an acceptable level. A set of nonlinearity measurements has been identified and performed on the proposed reconfigurable PIFAs. Prototypes are presented with PIN diode and E-PHEMT switches. For the purpose of comparison, measurements were also made with the active switch replaced with a copper bridge for linear interconnection. The nonlinearity performance can be evaluated from the measurement values of third-order intermodulation distortion (IMD3) products, ratio of IMD3 products to carrier, IMD3 products asymmetry, third-order input intercept point (IIP3) and 1-dB gain compression point (P$_1$$_-$$_d$$_B$). The measurements are performed when the antenna is transmitting signals. All measurements are performed on the state-of-the-art, 4-port ZVA67 Rohde & Schwarz VNA. Based on the nonlinearity measurements, it can be concluded that the presence of active switches has compromised the nonlinearity of the reconfigurable antennas. This is evident from the appearance of strong IMD3 products at the frequency of interest. In addition, the power-series-based approximation of 10 dB difference between the measured P$_1$$_-$$_d$$_B$ and IIP3 is shown to be reasonable. Moreover, this work has demonstrated that the ratio of the IMD3 products to carrier does not vary significantly with radiation angles

Modified Tamanu Plant-Based Oil from Pahang Malaysia as biodegradable metalworking fluids

Metalworking fluid (MWF) is a cooling and lubrication agent for the machining process. It is used as a coolant for rapid heat removal and provides a lubrication mechanism at the cutting zone. However, commercial MWFs such as synthetic ester and mineral oil give negative effects on human health and the environment. Therefore, the manufacturing industry should substitute commercial oil with vegetable-based oil. Calophyllum Inophyllum or also known as Tamanu is one of the feasible plant that has abundant oil quantity. In this study, modified Tamanu based oil with Trimethylolpropane ester (MTO) and modified Tamanu based oil with Pentaerythritol ester (MTOP) have been prepared and tested for their physical and tribological properties. Two types of ionic liquids; Phosphonium-based ionic liquid (PIL) and Ammonium-based ionic liquid (AIL) were added to each Tamanu-based oil (MTO and MTOP) to enhance their physical and tribological properties. Physical tests and Fourier Transform Infrared spectrometry (FTIR) were performed on each lubricant samples. The obtained results have shown that there is high viscosity index in MTOP + PIL 1 % and a lower double bond value in MTOP oil. MTOP + PIL 1 % has shown improvement in its tribological properties and can be comparable with commercial oil. Thus, it is suitable to be used as a substitute for commercial metalworking fluid in corresponding to green manufacturing activity

Physical measurement of the expansion rate of anisotropic tissue expander in the skin of the horse

Tissue expansion technique is one of the most important innovations in skin reconstructive surgery. In this study, anisotropic self-inflating hydrogel tissue expanders were implanted subcutaneously at different anatomical locations; frontal, right shoulder and right forelimb of horses. The resulting skin expansion were observed and recorded daily for the duration of 28 days by manual physical measurements. The rate of height growth and swelling that were recorded are 164.25% at the frontal region of the head, 189.13% at the shoulder region and 122.42% at the forelimb region. The growth of the tissue expander in the three sites could be summarized in three phases; biodegradable in week one, the peak of anisotropic expansion in week two and three, and final degree of swelling in week four

Characteristics and young's modulus of collagen fibrils from expanded skin using anisotropic controlled rate self-inflating tissue expander

Mechanical properties of expanded skin tissue are different from normal skin, which is dependent mainly on the structural and functional integrity of dermal collagen fibrils. In the present study, mechanical properties and surface topography of both expanded and nonexpanded skin collagen fibrils were evaluated. Anisotropic controlled rate self-inflating tissue expanders were placed beneath the skin of sheep's forelimbs. The tissue expanders gradually increased in height and reached equilibrium in 2 weeks. They were left in situ for another 2 weeks before explantation. Expanded and normal skin samples were surgically harvested from the sheep (n = 5). Young's modulus and surface topography of collagen fibrils were measured using an atomic force microscope. A surface topographic scan showed organized hierarchical structural levels: collagen molecules, fibrils and fibers. No significant difference was detected for the D-banding pattern: 63.5 ± 2.6 nm (normal skin) and 63.7 ± 2.7 nm (expanded skin). Fibrils from expanded tissues consisted of loosely packed collagen fibrils and the width of the fibrils was significantly narrower compared to those from normal skin: 153.9 ± 25.3 and 106.7 ± 28.5 nm, respectively. Young's modulus of the collagen fibrils in the expanded and normal skin was not statistically significant: 46.5 ± 19.4 and 35.2 ± 27.0 MPa, respectively. In conclusion, the anisotropic controlled rate self-inflating tissue expander produced a loosely packed collagen network and the fibrils exhibited similar D-banding characteristics as the control group in a sheep model. However, the fibrils from the expanded skin were significantly narrower. The stiffness of the fibrils from the expanded skin was higher but it was not statistically different

Subcutaneous implantation of unidirectional self-inflating anisotropic tissue expander has no effect on the physiological parameters and behaviours of horses

The tissue expansion technique is one of the most important innovations in skin reconstructive surgery in human and veterinary medicine. This study investigated horses’ physiological and behavioural responses to subcutaneous implantation of a unidirectional self-inflating anisotropic tissue expander. The tissue expanders were subcutaneously implanted on six horses at three different locations: the frontal region of the head, the lateral side of the right shoulder, and the dorsomedial part of the cannon region of the right forelimb. Prior to the tissue expander implantation, each horse was clinically examined, and the observed vital parameters and behaviour were recorded as baseline data. For six days post implantations, the horses were clinically examined, implantation sites monitored, and the horse’s behaviour was recorded both during the day by visual observation and at night with a video camera. The results showed that all horses tolerated the subcutaneous gradual skin expansion by implantation of the tissue expanders, and all surgical sites healed without any complications. The implantation of the tissue expanders does not affect the vital parameters or overall horse behaviour either during the day or at night. In conclusion, the subcutaneous implantation of unidirectional anisotropic tissue expanders in horses resulted in successful skin growth with no physiological and psychological discomfort; hence skin expansion is a good option to be considered when pursuing equine skin reconstructive surgery