Year
Publisher
Journal
1
Institution
Institution Country
Publication Type
Field Of Study
Topics
Open Access
Language
Filter 1
Year
Publisher
Journal
1
Institution
Institution Country
Publication Type
Field Of Study
Topics
Open Access
Language
Filter 1
Export
Sort by: Relevance
Potential Red Algae Fibre Waste as a Raw Material for Biocomposite

Red algae are abundant worldwide, and their exploitation for the development of agar products has developed into a significant industry in recent years. Industrial processing of red algae produces a significant amount of solid fibre waste, which contributes to substantial environmental problems. Agar from red algae is mostly used in the food, cosmetic, and pharmaceutical industries. There has been very limited research on the use of red algae in lignocellulosic composites so far. As such, this project aims to fabricate red algae reinforced with polylactic acid (PLA) as composite materials and to investigate the composite's mechanical, physical, and durability properties, as well as its characterization. The composite is fabricated using an extruder and a hydraulic hot press machine in three different composition ratios: 200:0, 180:20, and 160:40 (PLA: fibre (g)). Each sample was subjected to tensile testing for mechanical properties, melt flow index (MFI), scanning electron microscopy (SEM) testing for physical properties, and thermogravimetric analysis (TGA) testing for thermal properties. For durability testing, the samples were buried underground to determine the weight loss of composites over two weeks. The results indicate that while red algae have exceptional thermal properties, however, the strength and durability of the composite decrease with the inclusion of fibre. It is recommended that fibres be treated with an alkaline solution to improve their characteristics before being used as a composite.

Read full abstract
Open Access
Zero-Biasing Split Ring Resonator using Metamaterial Element for High Gain Superstrates Ultra-Wideband Antenna

Complex materials with artificial structures known as metamaterials (MTM) have unique properties that draw several scientists to use them in a variety of research fields. In addition, MTM can go beyond some of the restrictions placed on tools used in technical practise while improving the characteristics of microwaves. The Internet of Things (IoT) application calls for the construction of zero-index Split Ring Resonator (SRR) MTM element superstrates with an ultra-wideband antenna. Keep in mind that the MTM simulates behaviour that is not found in nature, namely the zero-reflection phase (dB) on the resonance frequency. For this project, an antenna with an SRR MTM unit cell operating at 2.70 GHz is built. The SRR has four inductance-related loops (r1, r2, r3, and r4), and gaps (slots) are added to the ring to produce the capacitance effect. Parametric research has been done for the SSR in the interim to identify the best design with zero indexes, permittivity and permeability at the desired frequency. The MTM unit cells array design's 7 x 4 and 10 x 5 dimensions achieved a dB of 0° at the 2.70 GHz frequency range. A 7 x 4 MTM unit cell makes up the first design, MTM Antenna Design 1, which at 2.70 GHz recorded a gain of 5.70 dB and a return loss (S11) of -20.007 dB. The return loss (S11) at a frequency of 2.70 GHz was -19.734 dB in the second design, an MTM antenna consisting of 10 x 5 MTM unit cells, which recorded a gain of 5.66 dB.

Read full abstract
Open Access
Influence of Palm Kernel Shell on Mechanical Properties on The Achievement of Kernelrazzo Concrete Floor Finish Production

The purpose of this research report is to disseminate the findings of a study on the consequences of palm kernel shell on the mechanical properties of kernelrazzo concrete floor finishes made using the Department of Environment (DoE) design method combinations of cement, quarry dust, as well as palm kernel shell in place of some marble chippings. The use of palm kernel shell, which is readily available as a coarse aggregate substitute, is the only option allowed for this research project to minimize the self-weight or dead load of the floors and to cut the cost of construction. Quarry dust was used as a fine aggregate, while marble chips and palm kernel shell were used as coarse aggregates. There were six distinct concrete mixtures created, and it is significant to note that, when considering the degree of workability values, the results of their slump tests are quite good. The possible significance of this research is that just 19 mm granite with a water-cement ratio of 0.5 was obtained at 28 days, the compressive strength grade of 30.50 N/mm2, 22.32N/mm2, 26.46 N/mm2, 19.72N/mm2, 16.47N/mm2 and 12.96N/mm2 respectively while flexural strength concrete grade of 5.44 N/mm2, 3.85N/mm2, 4.56 N/mm2, 3.01N/mm2 and 2.46N/mm2. There is no result at 50% palm kernel shells, concrete is good in compression but weak in tension. The research work's contribution to knowledge is in the awareness it provides regarding the potential use of agro-waste materials, prevention of epidemic and other related diseases that may arise from waste palm kernel shells and source of income generation and reduction of economic loss that may result from early kernelrazzo concrete floor finishes failure in urban and rural communities, in yards for offices and factories due to incorrect concrete proportioning with a maximum of 33% quarry dust and 20% palm kernel shell replacement with marble chippings.

Read full abstract
Open Access
Comparing the Effects of Gamification to User Engagement in Stress Management Application

The increasing accessibility of mobile technology makes it easier for users to use health related applications to combat health issues. In addition to this, gamification has been widely used to increase the engagement between user and application. This study provides an insight into how gamification affects user engagement when using stress management application. Two versions of stress management application were developed, one with gamification element, and the other one without. These two applications were then evaluated by 20 participants using the UES-SF questionnaire, where data on the engagement level of the participants were collected and analysed. The results showed that all participants (100%) prefer the application with gamification to help them manage their stress level better. Statistical tests done revealed that the stress management application with gamification was also found to be significantly more engaging compared to stress management application without gamification (given p ≤ .05). A Wilcoxon Signed-Ranks test indicated that gamified stress management application was rated more favourably than the non-gamified stress management application, with Z score = -3.92, and p = 0.00. The results demonstrated the significance of gamification in increasing user engagement among users when using stress management application.

Read full abstract
Open Access
Phytochemical Properties, Antioxidant Activity and α- Amilase Inhibitory of Curcuma Caesia

Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia, which produces free radicals, particularly reactive oxygen species (ROS), through glucose auto-oxidation and glycosylation. Administration of antioxidants and polyphenolic compound components can capture free radicals and reduce oxidative stress. Polyphenols are also able to reduce blood glucose levels by inhibiting the action of amylase enzymes as carbohydrate catabolism so that glucose absorption does not occur. One of the plants that contain polyphenols is Black Turmeric (Curcuma caesia). Some studies on the rhizomes of this plant include methanol extracts containing phenolics, Flavonoids, alkaloids, triterpenoids, saponins, and tannins. Dry powders and wet rhizome powders were studied to have antioxidant activity. Research on the inhibition of the enzyme alfa amylase is still lacking. This study aims to determine the content of chemical compounds using 70% ethanol solvent. The total phenolic and flavonoid assay with spectrophotometry, determine antioxidant activity using DPPH (2,2-diphenyl-1-picrylhydrazyl) at 490 nm and inhibition of α-amylase enzyme using 3,5- dinitro salicylic acid (DNS) at 529 nm. The results showed that phenolic levels were 235 mgGAE/100gr, flavonoids were 61 mg QE/100gr, Alkaloids 30 mg Quinine /100gr and saponin 158 mg Quillaja bark/100gr, dan tannin 535mg tannic acid/100gr. DPPH antioxidant activity obtained IC50 value of 299,18 µg/mLµg/mL and α- amylase inhibitory 50,26 µg/mLµg/mL. The research showed that 70% ethanol extract Curcuma caesia roxb contains phenolic, flavonoids, alkaloids, quinine, and saponins constituents and have been antioxidant activity and high α-amylase inhibitory

Read full abstract
Open Access