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  • Open access
  • 11 Reads
Study on Affect by Calculation Algorithm for Material Probability Curve on Roughness Parameters of Plateau Surface

Industry requires effective evaluation methods for quality control of automobile parts and bearings. The ISO standard defines the calculation of roughness parameters from material ratio curve ("MRC") and material ratio curve on normal probability paper ("MPC") as effective methods for evaluating surfaces with excellent lubrication and frictional characteristics. ISO 4287 specifies the slice method as a calculation method for MRC. The analysis time of the slice method is lengthy owing to the large amount of calculation. Therefore, ISO 21920-2 specifies the sort method as a calculation method for MRC. The Sort method significantly reduces analysis time owing to the small amount of calculation. A previous study revealed that errors occurred in the MRC by the sort method compared to the slice method. However, the previous study concluded that the errors were acceptable compared to the time cost. In addition, a plateau surface is a surface with excellent sliding property. The roughness parameters of a plateau surface have to be calculated from MPC. However, in the case of expression on normal probability paper, the difference between MRCs calculated using the sort and slice methods increases as both ends approach. Therefore, the roughness parameters calculated by each MPC are expected to be different results. This study reports the affect that increasing differences have on the roughness parameters. We aim to contribute to the establishment of a highly effective evaluation method by verifying the validity of calculating MPC by the sort method.

  • Open access
  • 98 Reads
A Review on Recent Developments in Plasma Separators Lab-on-Chip Microfluidics Devices and the Experimental Analysis of FFF 3D Printed Surfaces
Published: 02 December 2022 by MDPI in 3rd International Electronic Conference on Applied Sciences session Student Session

Viruses like COVID-19 need faster detection and sampling than the rate at which they spread to ensure the country’s sustainable health recovery. Blood plasma has proven to be a crtitical and better clinical sample for the detection of various medical conditions as compared to whole blood. For in-situ and in-vivo health monitoring, plasma can be easily processed through Microfluidics Lab-On-Chip (LOC) Devices without clotting that shortens the turnaround time with minimum sample and reagents. The presented work discusses key properties of Blood Plasma, its suitability to Microfluidics LOC applications and the importance of Passive Plasma Separators as an embedded unit within any kind of LOC Device. The Passive LOC Plasma Separators offer rapid extraction without external forces in the form of miniaturized automated unit. The article compares various plasma separators on the basis of plasma extraction efficiency, fabrication techniques, and separation science utilised for haemolysis free extraction. Recent development in the area of membrane based [1]; sedimentation-assisted [2], gravitational assisted [3], self-driven [4], and recently emerging plasma separators are discussed in detail. The article also gives an insight into the possible future developments towards the faster and more economical fabrication of such disposable devices and their economic extension. To further support our vision, we fabricated some Fused Filament Fabricated (FFF) 3D Printed parts and reported the minimum average roughness of 1.466µm and the contact angle 76.5°. The factorial analysis for two factor ANOVA without replication give a variance of σ2=0.175, and FESEM analysis of surfaces also depicts optimum surface quality.


  1. Amasia and Madau, “Large-volume centrifugal microfluidic device for blood plasma separation”, Bioanalysis 2010,
  2. Su, X.; Zhang, J.; Zhang, D.; Wang, Y.; Chen, M.; Weng, Z.; Wang, J.; Zeng, J.; Zhang, Y.; Zhang, S.; Ge, S.; Zhang, J.; Xia, N. High-Efficiency Plasma Separator Based on Immunocapture and Filtration. Micromachines 2020, 11, 352.
  3. Sanghoon Park, Roxana Shabani, Mark Schumacher, Yoon Seoung Kim, Young Min Bae, Kyeong Hee Lee, Hyoung Jin Cho, “On chip whole blood plasma separator based on microfiltration, sedimentation and wetting contrast”, Microsyst Technol, 2015;
  4. Wang, Y.; Nunna, B.B.; Talukder, N.; Etienne, E.E.; Lee, E.S. “Blood Plasma Self-Separation Technologies during the Self-Driven Flow in Microfluidic Platforms”, Bioengineering 2021, 8, 94.
  • Open access
  • 47 Reads
Weatherability of bio- versus fossil-based polyurethane coatings

The use of bio-based feedstock for formulation of protective coatings has been implemented in the supply of building blocks synthesized from biomass. Polyurethanes are of great interest due to their wide range of applications such as elastomers, fibers, foams, adhesives, coatings, or sealants. The alternation of traditional polyurethane coatings by bio-based polyurethanes focussed on the replacement of the polyisocyanate component in combination with polyester or polyacrylate polyols. In this research, the performance of an aliphatic isocyanate synthesized from crude oil (i.e., HDI or hexamethylenediisocyanate) has compared to an alternative synthesized through fermentation of biomass (i.e., PDI or pentamethylenediisocyante). As the chemical structure of the bio-based PDI is slightly different with an aliphatic chain of five compared to six carbon atoms, similar or better performance as protective coating is demonstrated. The application of the bio-based PU coatings on steel coupons resulted in lower drying times and higher hardness with similar gloss, chemical resistance and scratch resistance. In particular, the resistance of bio-based coatings after QUV accelerated weathering testing was improved owing to the better hydrophobicity of bio-based polyurethane coatings. There was a gradual trend in evolution of the performance with stepwise replacing fossil-based into bio-based content up to a maximum bio-content of 25% in the coating.

  • Open access
  • 21 Reads
Curing characteristics of urethane-dimethacrylate homopolymers and their composites for potential application in bone cement

The polymerization of methacrylate compositions used in bone cement is often accompanied by a strong exothermic effect. The polymerizing mass heats up to very high temperatures at the cement application site, irritating the adjacent tissues and even cell death. On the other hand, a bone cement composition should have optimal curing time, which should be long enough to allow for proper preparation of the cement and short enough to prevent leaking of the cement out of the restoration place. Therefore, new compositions are sought to reduce the curing temperature of bone cement and maintain a sufficiently long curing time. Our proposal is based on using five homopolymers obtained by polymerizing urethane-dimethacrylates. They were composed of diisocyanate cores: tolylene 2,4 diisocyanate (TDI), isophorone diisocyanate (IPDI), 4,4′-methylenebis(cyclohexyl isocyanate) (CHMDI), and wings: di-, tri-, and tetraethylene glycol monomethacrylate (respectively DEGMMA, TEGMMA, TTEGMMA). The following monomers were obtained: DEGMMA/CHMDI, TEGMMA/IPDI, TEGMMA/TDI, TEGMMA/CHMDI, and TTEGMMA/CHMDI. Neat homopolymers as well as their composites with barium sulfate and hydroxyapatite were tested for curing temperature and time. All proposed systems were characterized by appropriate values of both parameters. The presence of fillers positively affected the studied parameters by lowering the polymerization temperature and time.

  • Open access
  • 45 Reads
Influence of the Characterization Methodology on the Repair Performance of Self-Healing Materials
Published: 02 December 2022 by MDPI in 3rd International Electronic Conference on Applied Sciences session Student Session

Covalent Adaptable Network (CAN) chemistry has been extensively introduced in thermoset resins in order to achieve self-healing properties. These vitrimeric polymers are composed of dynamic covalent bonds that break and re-form reversibly when subjected to an external stimulus, such as an increase of the temperature, pH variations, or UV induction. Among the different self-healing mechanisms, aromatic disulfide bridges have attracted much attention on recent works. These CANs are based on exchange reactions between adjacent S–S bonds that trigger a decrease of the viscosity that permits the polymer gain a high molecular mobility state and flow to recover from distortions, being able to restore the original properties of the material, i.e, self-healing.

Although repair phenomena have been demonstrated in previous investigations by healing cracks from a scratched surface, this kind of damage leads to material loss. Consequently, the restored material volume may not be the same as the original, so that the self-healing performance is expected to be degraded.

In this regard, this research is focused on the study of the effect of the characterization methodology on the repair performance of self-healing materials. In this work, disulfide bonds were incorporated into an epoxy monomer with 2-Aminophenyl disulfide (AFD). The surface of the specimens was cut to generate cracks of different controlled depths. The self-healing efficiency was calculated from the relation between the volume of the damaged zone prior and after being repaired via thermal convective stimulus. The creep volumes were calculated and characterized from the images obtained with an optical profilometer. In addition, a comparative analysis between the volumes obtained via the optical profilometer and a Field Emission Gun – Scanning Electron Microscope (FEG-SEM) is included in order to ensure that acceptable measurement tolerances were accomplished.

  • Open access
  • 23 Reads
MEMS vibrating ring gyroscope with worm-shaped support springs for space applications.

Microelectromechanical systems (MEMS) devices have gained tremendous attention in the field of smart electronics applications. MEMS vibrating gyroscope is a rotational inertial sensor that is exhaustively used in many applications from GPS, household, smart appliances to space applications. The reliability of MEMS devices for space applications is a big concern. The devices need to be robust against harsh environments. In this paper, we report a double-ring MEMS vibrating ring gyroscope with sixteen worm-shaped support springs. The inclusion of the two rings with sixteen worm-shaped springs enhances the sensitivity of the gyroscope. The design symmetry and the worm-shaped springs increase the robustness, better mode matching, and gyroscopic sensitivity against harsh environments. The design modeling of the gyroscope is investigated on the ANSYSTM software. The design of the vibrating ring gyroscope incorporates two 10 µm thick rings, an outer ring radius is 1000 µm and the inner ring radius is 750 µm. Both the rings are attached with sixteen worm-shaped springs and the whole structure is supported by a centrally placed anchor with a radius of 260 µm. The proposed gyroscope operates at two identical shapes of wine glass modes. The first targeted resonant mode was recorded at 29.02 kHz frequency and the second resonant mode of the same shape was recorded at 29.32 kHz. There is a low mode mismatch of 0.3 kHz observed between the two resonant frequencies which can be resolved with tuning electrodes. The initial modeling results show a good prospect design of a vibrating gyroscope for space applications.

  • Open access
  • 29 Reads
Fruit fly chemical communication with gut bacteria

Relationships between tephritids and microorganisms have been a focus of entomological research particularly due to the potential use of microbial emissions in pest control. Symbiotic interactions between fruit flies and their associated gut bacteria have been well-studied, however,the composition of volatile chemicals from these gut bacterial emissions and their role as mediators of fruit fly behaviour is still underexplored. Here we hypothesise that the volatile emissions from fruit flies gut microbionts may attract host flies. To this end, we isolated culturable bacterial species, mostly belonging to the family Enterobacteriaceae,from the midgut of wild adult Bactrocera tryoni, one of the most damaging horticultural pests in Australia. In a screening trap assay with more than 80 isolates, both male and female adult B. tryoni were attracted to the odors emitted by most cultured isolates and a few significantly deterred adult male and female flies. Gas Chromatography-Mass Spectroscopyanalyses revealed a number of microbial volatile organic chemicals (mVOCs) in the headspace of liquid cultures of isolated bacteria,including ketones, carboxylic acids, alcohols and esters. Electrophysiological assays of selected isolates with highest attraction identified a number of chemicals that elicit olfactory responses to adult Qflies. Behavioural assay determined the attraction potential of a few chemicals among these mVOCs. This is an important step in understanding fruit fly-bacteria chemical relationships and its potential to develop attractants and potentially repellents for fruit fly pest management.

  • Open access
  • 26 Reads
Use of H2O2 for the Morphology Control of Silver Nanostructures

Nanotechnology is a field that has advanced significantly in the last decades. Nanomaterials, as a result of their nanometric dimensions, exhibit unique properties that enhance their technological and biomedical applications. Metallic nanoparticles, like silver nanoparticles (AgNPs), have stood out due to their intrinsic properties, such as the localized surface plasmon resonance, which can be controlled by their size and shape. Thus, in this work, we developed a practical synthetic procedure to obtain AgNPs with controlled morphology. AgNPs were prepared in water by the chemical reduction methodology, using different stabilizers under room temperature or with heating, and sodium borohydride as the reducing agent. The results obtained showed that the AgNPs were successfully prepared, using polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) as the stabilizing agents. The AgNPs' shape could be controlled by the absence or presence of H2O2, forming nanospheres or nanoprisms, respectively. The nanomaterials prepared exhibited colloidal stability with a negative surface charge, and TEM images confirmed their spherical and prismatic morphology. Furthermore, the results showed that the two synthesis conditions, room temperature and heating, afforded AgNPs in spherical and prismatic shapes, however, with temperature the size distribution was lower. Thus, this methodology has the potential to be expanded to other stabilizing agents as a simple and practical method to prepare silver nanostructures with controlled morphology.

  • Open access
  • 159 Reads
Kurdish Music Genre Recognition Using CNN and DNN

Music has different styles, and they are categorized into genres by musicologists. Nonetheless, non-musicologists categorize music differently, for example, by finding similarities and patterns in instruments, harmony, and style of the music. For instance, in addition to popular music genre categorization, such as classic, pop, and modern folkloric Kurdish music is categorized by Kurdish music lovers according to the type of dance that could go with a particular piece of music. Due to technological advancements, technologies such as Artificial Intelligence (AI) can help in music genre recognition. Using AI to recognize music genres has been growing lately. Computational musicology uses AI in various sectors of studying music. However, the literature shows no evidence of addressing any computational musicology research focusing on Kurdish music. Particularly, we have not been able to find any work that indicates the usage of AI in the classification of Kurdish music genres. In this research, we compiled a dataset that comprises 880 samples of eight Kurdish music genres. We used two machine learning models in our experiments, a Convolutional Neural Network (CNN) and a Deep Neural Network (DNN). According to the evaluations, the CNN model achieved 92% accuracy, while DNN achieved 90%. Therefore, we developed an application that uses the CNN model to identify Kurdish music genres by uploading or listening to Kurdish music.

  • Open access
  • 36 Reads
Effective corrosion inhibition of mild steel in an acidic environment using an aqueous extract of macadamia nut green peel biowaste

Improving the corrosion resistance of mild steel in an acidic aqueous environment is an important industrial consideration due to the use of acids for descaling and cleaning. The application of corrosion inhibitors is one of the most effective, simple and economical means of protecting metals against corrosion. Plant-derived compounds have recently gained attention due to their low cost, non-toxic, and environmentally friendly properties. Biowastes are recognized as a potential cheap source of green corrosion inhibitors, and their use can help reduce the wastes discharged to the environment. Green peel biowaste (GPBW) generated from macadamia nut processing is typically dumped into the environment, posing a disposal concern. This research, we investigated the use of GPBW as a source of useful organic compounds with green chemistry attributes for mild steel corrosion inhibition in an acidic solution (2 M HCl) using gasometric and optical methods. Results showed that mild steel corrosion rates decreased as extract concentrations increased. As a result, mild steel corrosion inhibition increased with increasing inhibitor concentration and reached a peak value of 81% at 0.5 g/L extract concentration. The optical images showed that the inhibitor molecules adsorb on the metal surface to form a protective film that isolates the mild steel from the corrosive solution. The adsorption of inhibitor molecules on the mild steel surface followed the Langmuir adsorption isotherm, indicating the formation of a monolayer film with a homogeneous distribution of adsorbed molecules. A Gibbs free energy (G°ads) of 24 kJ/mol indicated the inhibition process is mainly characterized by physical adsorption. The results of this study suggest that aqueous GPBW extract could serve as an inexpensive, non-toxic, and renewable corrosion inhibitor of mild steel in acidic solutions.