THERMAL BEHAVIOR IMPROVEMENT OF BIODEGRADABLE FIBER POLYMER COMPOSITES POLYLACTIC ACID (PLA)/COIR USING ACEH’S BENTONITE

Research has been conducted on the manufacture of PLA Coir Bentonite composites. This study aims to examine the effect of PLA on mechanical strength with the addition of coir and bentonite fillers from North Aceh and Central Aceh. The sample formulations used were single polymer PLA/Coir and PLA/Coir with variations of filler Bentonite Aceh Utara and Aceh Tengah with 2, 4, 6 and 8% respectively. The combination of PCa samples showed the highest bacterial colony growth rate, which was more than 100 colonies/gram during the 1 week testing period. In the PBATd filler mixture sample, the maximum bacterial test value was 65 colonies/gram and the minimum value contained in the PBAUa sample was 105 colonies/gram. The best tensile strength was obtained in the PBATc sample, namely 65 MPa. PBATd samples began to degrade at 370.15oC compared to PCa samples degraded at 280.21oC. While the PBAUa sample began to degrade at a temperature of 282.11oC. The surface structure of the PCa sample is more homogeneous because there is no bentonite filler mixture, but it is brittle and crumbles easily. For the PBATd sample, the surface structure is smoother and more homogeneous compared to the PBAUa sample.

A label-free and sensitive fluorescence assay for hyaluronidase activity through electrostatic-controlled quantum dots self-assembly

A label-free fluorescence assay for hyaluronidase (HAase) activity based on self-assembly of quantum dots is developed. A cationic polymer (polycation) can induce aggregation of the negatively charged quantum dots through electrostatic interactions and the fluorescence of the quantum dots is quenched. When the polycation is mixed with hyaluronic acid (HA), intense binding of HA to the polycation makes the quantum dots free and recovery of the fluorescence of the quantum dots is observed. However, in the presence of HAase, HA is hydrolyzed into small fragments and the polycation induces reaggregation of the quantum dots. A simple and rapid fluorescence sensor with high sensitivity and selectivity for HAase activity detection is therefore successfully established with a detection limit of 0.01 U/mL. Moreover, we have demonstrated an assay that can be applied to detect HAase activity in a complex mixture sample including 1% human serum.

Amino Acid Profiling with Chemometric Analysis as a Feasible Tool for the Discrimination of Marine-Derived Peptide Powders

Marine-derived peptide powders have suffered from adulteration via the substitution of lower-price peptides or the addition of adulterants in the market. This study aims to establish an effective approach for the discrimination and detection of adulterants for four representative categories of marine-derived peptide powders, namely, oyster peptides, sea cucumber peptides, Antarctic krill peptides, and fish skin peptides, based on amino acid profiling alongside chemometric analysis. The principal component analysis and orthogonal partial least squares discriminant analysis results indicate that four categories of marine-derived peptides could be distinctly classified into four clusters and aggregated with the respective raw materials. Taurine, glycine, lysine, and protein contents were the major discriminants. A reliable classification model was constructed and validated by the prediction dataset, mixture sample dataset, and unclassified sample dataset with accuracy values of 100%, 100%, and 100%, respectively.

Evaluation of the Effects of Filler Fineness on the Properties of an Epoxy Asphalt Mixture

The type and fineness of a filler significantly affect the performance of an asphalt mixture. There is a lack of specific research on the effects of filler fineness and dust from aggregates on the properties of epoxy asphalt (EA) mixtures. The effects of aggregate dust and mineral powder on the properties of an EA mixture were evaluated. These filler were tested to determine their fineness, specific surface area and mineral composition. The effects of these fillers on the EA mastic sample and mixture were evaluated. The morphology of the EA mastic samples was analyzed using scanning electron microscopy (SEM). The effects of the fillers on the Marshall stability, tensile strength and fatigue performance of the EA mixture were evaluated. The dust from the aggregates exhibited an even particle size distribution, and its average particle size was approximately 20% of that of the mineral powder. The SEM microanalysis showed that the EA mastic sample containing relatively fine dust formed a tight and dense interfacial bonding structure with the aggregate. The EA mixture sample containing filler composed of dust from aggregate had a significantly higher strength and longer fatigue life than that of the EA sample containing filler composed of mineral powder.

Optimised protocol of QIAamp® DNA mini Kit for bacteria genomic DNA extraction from both pure and mixture sample

As the sequencing technology developed, Next Generation Sequencing (NGS) has been used by more and more microbiology lab from different fields. Meanwhile , the quality of DNA will highly influence the sequencing result. Recently, there is an increasingly requirement for effective DNA extraction protocol to get high quality DNA from both pure and mixture cultures. Especially for researchers who what to study the microorganisms from complex mixture samples from food and environment. In this protocol, we modified the protocol of a commercial DNA extraction kit from Qiagen, and made it suitable for DNA extraction of different sample sources. The optimized protocol is proved to be effective. The DNA extracted with this protocol has been sent for NGS and get many interesting result.

Ternary Gas Mixture Quantification Using Field Asymmetric Ion Mobility Spectrometry (FAIMS)

Gas mixture quantification is essential for the recording and reproducing odors, because an odor consists of multiple chemical compounds. Gas mixture quantification using field asymmetric ion mobility spectrometry (FAIMS) was studied. Acetone, ethanol, and diethyl ether were selected as components of a ternary gas mixture sample as representatives of the ketone, alcohol, and ether chemical classes, respectively. One hundred and twenty-five points with different concentrations were measured. The results were evaluated by error hypersurface, variance, and the coefficient of variation. The error hypersurface showed that it is possible to reach the target composition by following the error-hypersurface gradient. Successful convergence was achieved with the gradient descent method in a simulation based on the measurement data. This result verified the feasibility of the quantification of a gas mixture using FAIMS.

Photocatalytic Efficiency of TiO2-Biomass Loaded Mixture for Wastewater Treatment

The objective of this study was to assess the efficiency of a novel TiO2/modified sago bark (TiO2/MSB) mixture for the degradation of sago wastewater effluent by employing response surface methodology (RSM) using chemical oxygen demand (COD) removal as the target parameter. The highest COD removal of 64.92% was obtained using TiO2/MSB mixture sample prepared by combining 0.2 g/L TiO2and 1 w/w% MSB. Given that the highest removal was produced using this mixture sample, further optimisation of sago wastewater treatment was conducted by varying the independent variables, namely, dosage and contact time. Under this optimum condition, 0.10 g of 0.2 g/L TiO2/1% MSB had successfully reduced 52.83% COD in 120 min. Surface morphology, functional groups, and elemental analysis supported observations of the ability of TiO2/MSB mixture to remove COD. Additionally, aeration had further improved COD removal by 11%. The regression value (R2>0.99) of the model indicated a high degree of correlation between the evaluated parameters. These results proved the feasibility of TiO2photocatalysis as an appealing alternative protocol for sago wastewater treatment and solid waste from the industry can be utilised for wastewater degradation.

An electrochemical sensor based on DNA polymerase and HRP-SiO2 nanoparticles for the ultrasensitive detection of K-ras gene point mutation

We developed a DNA sensor for the precise detection of point mutation of K-ras gene. The sensor was based on DNA replication, which employed the DNA polymerase I and the principle of base pairing, and can detect target DNA in mixture sample.

3-D Permeability Model of Porous Asphalt Mixture

3-D permeability model is set up through image analysis of porous asphalt mixture sample slice by cosmos image technique on the basis of 2-D permeability model of porous asphalt mixture. The result shows that the numerical simulation permeability outcome is consistent with the indoor permeability test outcome. The model can simulate any maximum congregate diameter in different water surface level and the permeability coefficient of any open-graded porous asphalt mixture. The model offers an effective method for the designing of the porous asphalt mixture.