Characteristics of micro incremental in-plane bending of sheet metal using tiltable punch

Incremental forming methods have gained interest in recent years as a forming technique for micro and fine components. This paper presents a newly developed incremental in-plane bending with tiltable punch for micro-metal sheets whose thickness is less than 1mm. The punch has two unique points. Firstly, it has a joint which enables the punch tilt freely according to the contact pressure. Secondly, the punch "sole" has a trapezoidal shape, where the toe is thin and the heel is wide. With increase of indentation, the toe bites deeper into metal than the heel resulting in the thickness distribution. As a result, the thin sheet metal is bent without any difficulty of punch positioning. Among the conditions of incremental bending, the effects of the toe angle of the punch sole during contact on the bending radius are examined by experiments, calculations and analysis. As a result, incremental forming with a tool with a toe angle of 30 degrees results in the largest sheet-metal curvature

Analisis Pelaksanaan Penagihan Pajak Penghasilan Terhadap Penunggak Pajak Di Kantor Pelayanan Pajak Pratama Jakarta Gambir Tiga

Taxes are the biggest source of state revenue. The Jakarta Pratama Tax Office Gambir Tiga has the highest target slogan in second place at 98.53% in 2019 but drops significantly to the lowest in second from bottom at 81.12% in 2020. The purpose of this study is to find out more regarding the tax collection process and how it impacts on tax revenues. This study uses library research research methods by processing data through a qualitative descriptive analysis approach. Based on the data analysis conducted, it was concluded that the most effective and efficient billing process during the Covid-19 pandemic was the process of blocking taxpayer accounts. Factors that cause tax arrears against the biggest tax arrears at the Jakarta Primary Tax Service Gambir Tiga are taxpayer ignorance, lack of oversight, and negligence of taxpayers

Valorization of bambangan (Mangifera pajang) by-product by extraction of mangiferin using ultrasonic assisted extraction

Bambangan (Mangifera pajang) is a fruit belonging to the Anacardiaceae family, which is a lesser-known member of the mango family. It is native to East Malaysia, namely in Sabah and Sarawak. This fruit possesses a significant amount of dietary fibre, is rich in juice, and emits a strong smell. Typically, around 35 – 40% of the fruit's total weight, which includes the peel and seed, is discarded as waste. Mangiferin, a xanthone Cglucoside possessing notable antioxidant and antibacterial characteristics, is predominantly present in the foliage of mango plants. This study employed ultrasonicassisted extraction (UAE) to extract mangiferin from bambangan peels and seeds. The study specifically investigated the impact of ethanol concentration (ranging from 40% to 60%), temperature (ranging from 40 °C to 60°C), extraction time (ranging from 5 to 15 minutes), and sample-solvent ratio (ranging from 1:10 to 1:30 w/v) on the concentration of mangiferin. Mangiferin was quantified using high-performance liquid chromatography (HPLC). The optimal conditions for extracting mangiferin using UAE were determined to be 50% ethanol concentration, temperature of 50°C, extraction time of 10 min, and a sample-solvent ratio of 1:20. The seeds of the bambangan fruit had the highest concentration of mangiferin at 264.89 ± 5.67 mg/mL, whereas the peels had a value of 94.82 ± 1.49 mg/mL. These findings indicate that the peels and seeds of bambangan have potential as alternate sources of mangiferin for the food and pharmaceutical industries

Solubility of Rosmarinic Acid in Supercritical Carbon Dioxide Extraction from Orthosiphon stamineus Leaves

Rosmarinic acid (RA) is present in a broad variety of plants, including those in the Lamiaceae family, and has a wide range of pharmacological effects, particularly antioxidant activity. To extract RA from Orthosiphon stamineus (OS) leaves, a Lamiaceae plant, a suitable extraction process is necessary. The present study used a green extraction method of supercritical carbon dioxide (SCCO2 ) extraction with the addition of ethanol as a modifier to objectively measure and correlate the solubility of RA from OS leaves. The solubility of RA in SCCO2 was determined using a dynamic extraction approach, and the solubility data were correlated using three density-based semi-empirical models developed by Chrastil, del Valle-Aguilera, and Gonzalez. Temperatures of 40, 60, and 80 ◦C and pressures of 10, 20, and 30 MPa were used in the experiments. The maximum RA solubility was found at 80 ◦C and 10 MPa with 2.004 mg of rosmarinic acid/L solvent. The RA solubility data correlated strongly with the three semi-empirical models with less than 10% AARD. Furthermore, the fastest RA extraction rate of 0.0061 mg/g min−1 was recorded at 80 ◦C and 10 MPa, and the correlation using the Patricelli model was in strong agreement with experimental results with less than 15% AARD

Effect of silver nanopowder on mechanical, thermal and antimicrobial properties of kenaf/HDPE composites

This study aims to investigate the effect of AgNPs on the mechanical, thermal and antimicrobial activity of kenaf/HDPE composites. AgNP material was prepared at different contents, from 0, 2, 4, 6, 8 to 10 wt%, by an internal mixer and hot compression at a temperature of 150 °C. Mechanical (tensile, modulus and elongation at break), thermal (TGA and DSC) and antimicrobial tests were performed to analyze behavior and inhibitory effects. The obtained results indicate that the effect of AgNP content displays improved tensile and modulus properties, as well as thermal and antimicrobial properties. The highest tensile stress is 5.07 MPa and was obtained at 10wt, TGA showed 10 wt% and had improved thermal stability and DSC showed improved stability with increased AgNP content. The findings of this study show the potential of incorporating AgNP concentrations as a secondary substitute to improve the performance in terms of mechanical, thermal and antimicrobial properties without treatment. The addition of AgNP content in polymer composite can be used as a secondary filler to improve the properties

Pasteurellosis vaccine commercialization: Physiochemical factors for optimum production

Pasteurella spp. are Gram-negative facultative bacteria that cause severe economic and animal losses. Pasteurella-based vaccines are the most promising solution for controlling Pasteurella spp. outbreaks. Remarkably, insufficient biomass cultivation (low cell viability and productivity) and lack of knowledge about the cultivation process have impacted the bulk production of animal vaccines. Bioprocess optimization in the shake flask and bioreactor is required to improve process efficiency while lowering production costs. However, its state of the art is limited in providing insights on its biomass upscaling, preventing a cost-effective vaccine with mass-produced bacteria from being developed. In general, in the optimum cultivation of Pasteurella spp., production factors such as pH (6.0–8.2), agitation speed (90–500 rpm), and temperature (35–40 °C) are used to improve production yield. Hence, this review discusses the production strategy of Pasteurella and Mannheimia species that can potentially be used in the vaccines for controlling pasteurellosis. The physicochemical factors related to operational parameter process conditions from a bioprocess engineering perspective that maximize yields with minimized production cost are also covered, with the expectation of facilitating the commercialization process

Synthesis of ZnO Nanorods at Very Low Temperatures Using Ultrasonically Pre-Treated Growth Solution

This paper investigates how the pre-treatment of the growth solution with ultrasonic energy affects the annealing temperatures and the growth temperatures of zinc oxide (ZnO) nanorods. The ultrasonic pre-treatment of the growth solution resulted in the successful growth of ZnO nanorods at a very low annealing temperature of 40 ◦C. The size and density of ZnO nanorods were found to increase proportionally with the increasing duration of pre-ultrasonic treatment, as indicated by characterisations performed with a scanning electron microscope (SEM). At an annealing temperature of 40 ◦C, coupled with ultrasonic waves, the SEM results showed that ZnO nanorods’ length and diameter increased by 37 and 25%. A similar pattern was also observed at an annealing temperature of 60 and 80 ◦C, where the length and diameter of ZnO nanorods increased. In addition, the conductivity and acidity of the aqueous solution that had been sonicated were measured. The results showed that solution conductivity and acidity increased as the ultrasonic treatment continued for longer periods. After 3 min of sonication, the final conductivity and acidity of the solutions were found to be 9164 µS/cm and 6.64, respectively. The results also indicated that the ultrasonic pre-treatment of the growth solution increased the zinc nutrient concentration, which would affect the formation of ZnO nanorods. In addition to the ultrasonic effect, the annealing temperature influenced the active nucleation sites essential to the ZnO nanorods’ expansion

Non-functionalized oil palm waste-derived reduced graphene oxide for methylene blue removal: Isotherm, kinetics, thermodynamics, and mass transfer mechanism

The discharge of colored effluents from industries is one of the significant sources of water pollution. Therefore, there is a growing demand for efficient and low-cost treatment methods. An adsorption process with reduced graphene oxide (rGO) synthesized using a novel double carbonization and oxidation method from the natural precursor of oil palm empty fruit bunch (OPEFB) as adsorbent is a promising approach for addressing the problem. In this study, OPEFB biochar was mixed with ferrocene with a ratio of 5:1 (m/m) and oxidized under nitrogen flow at a temperature of 300 �C for 20 min, which resulted in 75.8 wt% of yield. The potential of the synthesized rGO as an effective adsorbent for dye removal from water and wastewater was explored using methylene blue (MB) as a model. Several factors were investigated, including adsorbent dosage, initial concentration, contact time, and pH, to obtain the optimum adsorption condition through batch studies. The physical and chemical characteristics of the rGO in terms of functional groups

A review on the kenaf/glass hybrid composites with limitations on mechanical and low velocity impact properties

Environmental awareness and trends to develop sustainable resources have directed much research attention towards kenaf fibre as an alternative reinforcement in composite manufacturing. Numerous studies have been conducted on kenaf and its hybrid composites. Most studies were conducted on kenaf/glass hybrid composites compared to other kenaf/synthetic hybrid composites. Similar with other materials, mechanical properties were the fundamental knowledge identified by the researcher. Limited studies conducted on other properties have restricted the use of kenaf composites to non-structural applications. To extend the potential of kenaf composites to automotive exterior or other critical applications, studies on impact properties can be a valuable contribution in the material field. This review discusses the mechanical and low velocity impact properties of kenaf/glass hybrid composites reported previously. Percentage loading of fibre, the angle of orientation in woven fibres and the chemical treatment applied to the fibre before compounding are the three major parameters that affect the mechanical and impact properties of the composites. This review provides insights into the mechanical and impact properties of kenaf/glass hybrid composites for future research

A Review on the Kenaf/Glass Hybrid Composites with Limitations on Mechanical and Low Velocity Impact Properties

Environmental awareness and trends to develop sustainable resources have directed much research attention towards kenaf fibre as an alternative reinforcement in composite manufacturing. Numerous studies have been conducted on kenaf and its hybrid composites. Most studies were conducted on kenaf/glass hybrid composites compared to other kenaf/synthetic hybrid composites. Similar with other materials, mechanical properties were the fundamental knowledge identified by the researcher. Limited studies conducted on other properties have restricted the use of kenaf composites to non-structural applications. To extend the potential of kenaf composites to automotive exterior or other critical applications, studies on impact properties can be a valuable contribution in the material field. This review discusses the mechanical and low velocity impact properties of kenaf/glass hybrid composites reported previously. Percentage loading of fibre, the angle of orientation in woven fibres and the chemical treatment applied to the fibre before compounding are the three major parameters that affect the mechanical and impact properties of the composites. This review provides insights into the mechanical and impact properties of kenaf/glass hybrid composites for future research