Garuda - Garba Rujukan Digital

Effect of sonication to the stability properties of carboxymethyl cellulose/uncaria gambir extract water-based lubricant Rahmadiawan, Dieter; Ilhamsyah, Febrian; Abral, Hairul; Laghari, Imtiaz Ali; A, Yufrizal
Teknomekanik Vol. 5 No. 2 (2022): Regular Issue
Publisher : Universitas Negeri Padang

This study examined the effect of sonication on FTIR and stability at various temperatures in water-based lubricants with a mixture of Carboxymethyl Cellulose (1wt%) and Uncaria Gambir extract (1wt% and 2wt%). The sample was prepared by mixing the two materials into distilled water using a magnetic stirrer and sonicator with time variations of 5 and 10 minutes. Before mixing, the Uncaria Gambir extract solution with water is first centrifuged to remove the dregs in the Uncaria Gambir extract powder. Stability was carried out in an open room (28oC), drying oven (50oC), and refrigerator (5oC). The stability test results showed that the mixture of Carboxymethyl Cellulose and Uncaria Gambir had good stability at all temperatures after sonication for a short duration. The longer sonication duration could fuse the fibrils of Carboxymethyl Cellulose, leading to increasing particle size. FTIR results also show that there is no chemical reaction that occurs. After adding the gambier, there was a new peak at wave 800-1300 cm-1, corresponding to the gambier. The results of this study indicate that the Carboxymethyl Cellulose and Uncaria Gambir solution can be a potential lubricant additive. The Carboxymethyl Cellulose can be a viscosity modifier, while Uncaria Gambir extract for corrosion inhibitor.

Enhancing Current Density and Specific Capacitance of Nata de Coco, TEMPO, and MXene Composites through Boiling Time Variations Yunus, Syukri; Umah, Kuntum Khairah; Abral, Hairul; Ogah, Ogah Anselm; Aulia, Aulia
Andalasian International Journal of Applied Science, Engineering and Technology Vol. 3 No. 3 (2023): November 2023
Publisher : LPPM Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/aijaset.v3i3.110

This research aimed to enhance the current density and specific capacitance of electronic device materials to replace traditional metal materials. Composite materials that include Nata de Coco, TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl), and MXene achieve this improvement. Composite materials that include Nata de Coco, TEMPO, and MXene accomplish this improvement. Initial testing has shown that these materials initially demonstrated lower electrical properties, particularly in current density and specific capacitance, than conventional metals. To enhance their electrical properties, we employed a boiling method with variations in boiling time. The time intervals chosen were 30, 300, and 480 minutes. In the manufacturing process, Nata de Coco, previously oxidized by TEMPO, was boiled in an MXene solution at a temperature of 70°C. We tested the electrical properties of the resulting composite film, focusing on current density and specific capacitance. The measured current density values, corresponding to the different boiling times, were as follows: 0.000239 A/cm² for 30 minutes, 0.000307 A/cm² for 300 minutes, and 0.000320 A/cm² for 480 minutes. The specific capacitance values were 1.7005 F/g for 30 minutes, 1.9707 F/g for 300 minutes, and 2.0364 F/g for 480 minutes. The percentage increase in current density and specific capacitance values from 30 minutes to 300 minutes of boiling was 22% and 13.7%, respectively. For boiling from 300 to 480 minutes, the increase was 4.06% for current density and 3.22% for specific capacitance. These findings suggest that longer boiling times result in improved electrical properties. Subsequently, characteristic tests were performed, including XRD (X-ray diffraction) and SEM (Scanning Electron Microscope) analyses. The XRD results indicated that longer boiling times caused a rightward shift of the diffraction peak with a narrower peak width, signifying increased crystallinity. The highest X-ray intensity was observed in the composite boiled for 480 minutes, with a power of 847.23 counts per second (cps) and a two-theta angle of 21.31°. Additionally, the smallest crystal size was achieved with a 480-minute boiling time, measuring 138.2851 Å. In the SEM analysis, it was evident that longer boiling times led to a higher fraction of MXene within the composite film.

Enhancing Current Density and Specific Capacitance of Nata de Coco, TEMPO, and MXene Composites through Boiling Time Variations Yunus, Syukri; Umah, Kuntum Khairah; Abral, Hairul; Ogah, Ogah Anselm; Aulia, Aulia
Andalasian International Journal of Applied Science, Engineering and Technology Vol. 3 No. 3 (2023): November 2023
Publisher : LPPM Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/aijaset.v3i3.110

This research aimed to enhance the current density and specific capacitance of electronic device materials to replace traditional metal materials. Composite materials that include Nata de Coco, TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl), and MXene achieve this improvement. Composite materials that include Nata de Coco, TEMPO, and MXene accomplish this improvement. Initial testing has shown that these materials initially demonstrated lower electrical properties, particularly in current density and specific capacitance, than conventional metals. To enhance their electrical properties, we employed a boiling method with variations in boiling time. The time intervals chosen were 30, 300, and 480 minutes. In the manufacturing process, Nata de Coco, previously oxidized by TEMPO, was boiled in an MXene solution at a temperature of 70°C. We tested the electrical properties of the resulting composite film, focusing on current density and specific capacitance. The measured current density values, corresponding to the different boiling times, were as follows: 0.000239 A/cm² for 30 minutes, 0.000307 A/cm² for 300 minutes, and 0.000320 A/cm² for 480 minutes. The specific capacitance values were 1.7005 F/g for 30 minutes, 1.9707 F/g for 300 minutes, and 2.0364 F/g for 480 minutes. The percentage increase in current density and specific capacitance values from 30 minutes to 300 minutes of boiling was 22% and 13.7%, respectively. For boiling from 300 to 480 minutes, the increase was 4.06% for current density and 3.22% for specific capacitance. These findings suggest that longer boiling times result in improved electrical properties. Subsequently, characteristic tests were performed, including XRD (X-ray diffraction) and SEM (Scanning Electron Microscope) analyses. The XRD results indicated that longer boiling times caused a rightward shift of the diffraction peak with a narrower peak width, signifying increased crystallinity. The highest X-ray intensity was observed in the composite boiled for 480 minutes, with a power of 847.23 counts per second (cps) and a two-theta angle of 21.31°. Additionally, the smallest crystal size was achieved with a 480-minute boiling time, measuring 138.2851 Å. In the SEM analysis, it was evident that longer boiling times led to a higher fraction of MXene within the composite film.

Loading-dependent mechanical performance of alkali-treated areca nut husk fiber reinforced polyester composites modified with Uncaria gambir extract Nabawi, Rahmat Azis; Syahril, Syahril; Abral, Hairul
Teknomekanik Vol. 8 No. 2 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i2.52472

Natural fiber-reinforced polymer composites often experience mechanical performance limitations due to weak interfacial bonds between hydrophilic fibers and hydrophobic matrices. This study experimentally examined the effect of alkali treatment and modification using Uncaria gambir extract (UGE) on the mechanical properties and interface morphology of polyester composites reinforced with areca nut husk fiber (ANHF). Four composite configurations were prepared with a constant fiber weight fraction of 40 wt.% after alkali treatment using 6% NaOH for 24 hours, while the remaining 2 wt.% UGE was selectively applied as a fiber surface treatment, matrix additive, or a combination of both. Tensile and flexural properties were evaluated in accordance with ASTM standards, while interface morphology was examined using scanning electron microscopy (SEM). The results showed that alkali-treated composites without UGE addition had the highest tensile strength, which was attributed to increased fiber surface roughness and mechanical interlocking mechanisms. Conversely, fiber surface modification using UGE significantly increased flexural strength, indicating better stress distribution under flexural loading due to increased interface continuity. However, the addition of UGE to the matrix caused a decrease in tensile strength, which was thought to be related to a reduction in matrix stiffness. SEM observations confirm the presence of distinct interface morphology differences according to the treatment applied. These findings indicate that UGE serves primarily as a bio-based interfacial modifier, enhancing flexural performance, while its effectiveness is strongly governed by the mechanical loading mode.

Harnessing Rotating Heat Pipes for Passive Electric Motor Cooling: Enhancing Electric Vehicle Efficiency Siregar, Yasmine Karenita; Rezqi, Khairu; Putra, Gerardo Janitra Puriadi; Fathoni, Andhy M; Putra, Nandy; Abral, Hairul
Journal of Engineering and Technological Sciences Vol. 58 No. 1 (2026): Vol. 58 No. 1(2026): February
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2028.58.1.7

Electric vehicles are equipped with electric motors that convert electrical energy into mechanical energy to propel the vehicle. The motor experiences an increase in temperature during operation due to various losses that cause the motor temperature to rise. The performance of the electric motor will be reduced or even damaged if the heat continues to increase and the temperature exceeds 60°C. Therefore, there is a need for a cooling system that can maintain the electric motor's temperature within its working range. This study aims to investigate and test the rotating heat pipe (RHP) as a passive cooling system for electric motors. The objective of this research is to examine the performance of the RHP. The study employs a RHP with installed thermocouples on its surface. Additionally, a slip ring is utilized to serve as interface between the data acquisition module and the thermocouple sensor. In this investigation, the Rotating Heat Pipe was equipped with two slip rings to measure temperature in rotary conditions. This study proves that using RHP can reduce thermal resistance by 30-66% compared to stationary heat pipes.

Effect of MXene Loading on the Structure and Electrochemical Performance of Biodegradable PVA/ZnO/MXene/CNC Composite Films Fernandez, Rudy; Hairul Abral; Ikhwana Elfitri; Syukri Yunus
JURNAL NASIONAL TEKNIK ELEKTRO Vol 15, No 1: March 2026
Publisher : Jurusan Teknik Elektro Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jnte.v15n1.1555.2026

The growing demand for sustainable materials for flexible electronics and energy storage applications has driven the development of biodegradable composite films with enhanced electrochemical functionality. This study systematically investigates the effect of MXene loading on the structure, morphology, and electrochemical performance of biodegradable PVA/ZnO/MXene/CNC composite films fabricated by aqueous solution casting. The main contribution of this work is the explicit establishment of a relationship between loading, structure, and electrochemical performance for this multicomponent biodegradable film system under controlled processing conditions. Films containing 20%, 25%, and 30% MXene were prepared with constant ZnO and CNC contents and characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and cyclic voltammetry in 1 M KOH. The crystallinity increased from 20.06% to 27.58% and 44.74% with increasing MXene loading, while FESEM revealed progressively more homogeneous morphology and improved filler dispersion. These structural changes were accompanied by a marked enhancement in electrochemical response, with current density increasing from 425.18 to 876.71 and 1480.25 A/m², and specific capacitance rising from 0.921966 to 1.682536 and 2.860035 F/g for 20%, 25%, and 30% MXene, respectively. The 30% MXene film exhibited the best overall performance, indicating that higher MXene loading within the investigated range promotes more continuous conductive pathways and greater electroactive surface accessibility. These findings provide useful insight for designing biodegradable composite films for sustainable flexible energy-storage applications.

TAGUCHI EXPERIMENTAL STUDY: THE EFFECT OF BAY LEAF EXTRACT WEIGHT PERCENTAGE AND SAMPLE SIZE ON THE CHARACTERISTICS OF POLYVINYL ALCOHOL FILMS Hery Sunarsono; Hairul Abral; Adjar Pratoto; Elisabeth Feberlian Gulo; Melbi Mahardika; Mat Uzir Wahit; Vitri Aprila Handayani
Analit : Analytical and Environmental Chemistry Vol. 10, No. 02 October (2025) Analit : Analytical and Environmental Chemistry
Publisher : Jurusan Kimia FMIPA Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/analit.v10i02.231

This research aims to determine the optimum parameters for incorporating Indonesian bay leaf extract (DS) into a polyvinyl alcohol (PVA) matrix to form a new polymer, PVA/DS. Taguchi's experimental method was employed to obtain the anti-UV properties and optimal mechanical characteristics of the PVA/DS polymer. Factors studied include DS concentration and sample size. The experimental design was prepared using an orthogonal array L16. The ability to block UV radiation (anti-UV) and the mechanical properties of polymer films are determined using UV Vis spectra and tensile testing (ASTM D638). The results of the Signal-to-Noise Ratio analysis show that the DS concentration factor is the most dominant variable in the anti-UV response, with a DS concentration influence factor (delta) value of 72.261, compared to a sample thickness of 1.605. Likewise, for elongation at break, the delta value of DS concentration is 2.43, which is higher than the cross-sectional area of 1.31. Meanwhile, for the tensile strength performance, neither factor was significant; however, the cross-sectional area factor was more dominant than the DS concentration, with a cross-sectional area delta value of 3.29, which is higher than the DS concentration of 2.77. The addition of DS concentration to the anti-UV response is able to block 100% of UV rays compared to PVA, which is only 16%. Meanwhile, for tensile strength, there was a 50.98% increase. The tensile strength of PVA/DS1 reached 75.67 MPa compared to PVA, which was only 50.12 MPa. Meanwhile, elongation at break increased by 14.71% in PVA/DS0.5 (304.43%) compared to PVA (265.40%). Thus, this research successfully applied the Taguchi method to identify the optimum factor combination with a minimum number of experiments. PVA/DS1 film (1% DS) is a film with optimum conditions that can provide superior performance, making it an alternative to conventional plastics that do not decompose easily

Effect of sonication to the stability properties of carboxymethyl cellulose/uncaria gambir extract water-based lubricant Dieter Rahmadiawan; Febrian Ilhamsyah; Hairul Abral; Imtiaz Ali Laghari; Yufrizal A
Teknomekanik Vol. 5 No. 2 (2022): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v5i2.16972

This study examined the effect of sonication on FTIR and stability at various temperatures in water-based lubricants with a mixture of Carboxymethyl Cellulose (1wt%) and Uncaria Gambir extract (1wt% and 2wt%). The sample was prepared by mixing the two materials into distilled water using a magnetic stirrer and sonicator with time variations of 5 and 10 minutes. Before mixing, the Uncaria Gambir extract solution with water is first centrifuged to remove the dregs in the Uncaria Gambir extract powder. Stability was carried out in an open room (28oC), drying oven (50oC), and refrigerator (5oC). The stability test results showed that the mixture of Carboxymethyl Cellulose and Uncaria Gambir had good stability at all temperatures after sonication for a short duration. The longer sonication duration could fuse the fibrils of Carboxymethyl Cellulose, leading to increasing particle size. FTIR results also show that there is no chemical reaction that occurs. After adding the gambier, there was a new peak at wave 800-1300 cm-1, corresponding to the gambier. The results of this study indicate that the Carboxymethyl Cellulose and Uncaria Gambir solution can be a potential lubricant additive. The Carboxymethyl Cellulose can be a viscosity modifier, while Uncaria Gambir extract for corrosion inhibitor.

Loading-dependent mechanical performance of alkali-treated areca nut husk fiber reinforced polyester composites modified with Uncaria gambir extract Rahmat Azis Nabawi; Syahril Syahril; Hairul Abral
Teknomekanik Vol. 8 No. 2 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i2.52472

Natural fiber-reinforced polymer composites often experience mechanical performance limitations due to weak interfacial bonds between hydrophilic fibers and hydrophobic matrices. This study experimentally examined the effect of alkali treatment and modification using Uncaria gambir extract (UGE) on the mechanical properties and interface morphology of polyester composites reinforced with areca nut husk fiber (ANHF). Four composite configurations were prepared with a constant fiber weight fraction of 40 wt.% after alkali treatment using 6% NaOH for 24 hours, while the remaining 2 wt.% UGE was selectively applied as a fiber surface treatment, matrix additive, or a combination of both. Tensile and flexural properties were evaluated in accordance with ASTM standards, while interface morphology was examined using scanning electron microscopy (SEM). The results showed that alkali-treated composites without UGE addition had the highest tensile strength, which was attributed to increased fiber surface roughness and mechanical interlocking mechanisms. Conversely, fiber surface modification using UGE significantly increased flexural strength, indicating better stress distribution under flexural loading due to increased interface continuity. However, the addition of UGE to the matrix caused a decrease in tensile strength, which was thought to be related to a reduction in matrix stiffness. SEM observations confirm the presence of distinct interface morphology differences according to the treatment applied. These findings indicate that UGE serves primarily as a bio-based interfacial modifier, enhancing flexural performance, while its effectiveness is strongly governed by the mechanical loading mode.

Trade-offs in thermal and mechanical properties of cellulose films from bacterial cellulose powder induced by ultrasonication duration Dieter Rahmadiawan; Tio Baskara; Hairul Abral; Eni Sugiarti; Ahmad Novi Muslimin; Shih-Chen Shi; Thiago F. Santos; Imtiaz Ali Laghari
Teknomekanik Vol. 9 No. 2 (2026): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v9i2.57372

Understanding the trade-offs between thermal and mechanical properties is crucial for optimizing the performance of cellulose films from bacterial cellulose powders (BCP). This study leverages ultrasonication as an eco-friendly method to enhance these properties in BCP-based films while investigating the consequences of varying ultrasonication durations. BCP was sonicated at 250 W for 15 and 30 minutes. Results demonstrated that increasing ultrasonication duration significantly improves tensile strength, toughness, and transparency. The 30-minute sonication yielded the most robust and transparent films, with the highest mechanical strength and toughness. Conversely, while a shorter sonication of 15 minutes slightly improved the thermal stability of the films, increasing Tmax from 317°C for non-sonicated films to 351°C, a longer duration of 30 minutes reduced Tmax to 323°C. This illustrates a clear trade-off between enhancing mechanical properties and maintaining thermal stability. The findings provide insights into a simple yet effective approach for producing environmentally friendly, non-wood-based BC films, emphasizing the need to balance both thermal and mechanical enhancements through controlled ultrasonication.

Title

Found 23 Documents
Search

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Title Search

Found 23 Documents Search

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Title

Found 23 Documents
Search