Prediction of Nickel Removal using Diffusion Model in Flat Sheet Supported Liquid Membrane

Supported liquid membrane (SLM) is one of the potential extraction methods for the treatment of wastewater containing various toxic heavy metal ions. Advantageously, this process offers simultaneous removal and recovery, as well as low energy consumption and operational cost. In this study, the prediction of nickel removal was investigated using a diffusion model developed through MATLAB.

Bioactivity Evaluation of Leucas zeylanica and its Phytochemicals

Leucas zeylanica belongs to the Lamiaceae family has high medicinal value. The phytochemicals screening results showed that terpenoids, flavonoids, tannins, saponins, phenols and alkaloids are present in aerial part of L. zeylanica.Vacuum liquid chromatography (VLC) and column chromatography (CC) techniques were used in fractionation and purification of the crude extracts.

Two-Stage Adsorber Design for Methylene Blue Removal by Coconut Shell Activated Carbon

The present work was aimed at evaluating the performance of two-stage adsorber for methylene blue removal by coconut shell activated carbon in minimizing the adsorbent mass and contact time. The Langmuir constants were used to evaluate the optimum mass, while the pseudo-second-order constants for contact time. Results show that the adsorbent mass can only be minimized by 0.01 % due to the high adsorbent affinity towards methylene blue, while the contact time has been optimized to 12.2 min at the studied conditions. The effect of adsorbent affinity in two-stage adsorber was analyzed to shed some light about its importance in the design of two-stage adsorber. The performance evaluation was also discussed to bring insight into wastewater treatment applications.

Extraction and Solubility Modeling of Anthocyanins Rich Extract from Hibiscus sabdariffa L. using Supercritical Carbon Dioxide

This study aimed to evaluate the extraction yield, and anthocyanins content of Hibiscus sabdariffa L. calyces extract using different temperatures (T) at 50 - 70°C, pressure (P) at 8 - 12 MPa, and modifier ratio at 5 - 10%.

Nitrogen Tailored Activated Carbon via Microwave Synthesis Method for High Removal of Hydrogen Sulfide

In this work, commercialized palm shell activated carbon was modified into nitrogen-functionalized carbon via urea impregnation method, followed by heat treatment via microwave irradiation at 950 °C.

Physio-biochemical Responses of In Vitro Cooking Banana Musa paradisiaca cv Lang towards Pseudo Induced Drought Stress by Polyethylene Glycol (PEG)

Musa paradisiaca cv Lang belongs to cooking banana group, and it has high potential to be used in banana chips production. Like other cultivars, M. paradisiaca cv Lang is susceptible towards water shortage, therefore affecting banana growth and productivity. In this study, to mimic the drought condition, pseudo-drought stress was given to in vitro Lang banana seedlings by adding polyethylene glycol (PEG). Overall, decrement of roots length and chlorophyll (Chl) content was displayed by the seedlings exposed to 1%, 2%, 3%, 4%, and 5% (w/v) of PEG after three weeks of exposure. The proline content, total soluble protein content, and antioxidant capacity in leaf and roots, however, countered differently towards different levels of drought. Proline content showed the highest in leaf of 2% (w/v) PEG-treated seedling (12.66±0.38 µmoles/g) while the total soluble protein content showed the highest in roots of 5% (w/v) of PEG-treated seedling (30.65±1.07 mg/g FW). Antioxidant capacity of stressed seedlings revealed the catalase (CAT), guaiacol peroxidase (POD), and ascorbate peroxidase (APX) activities were the highest in the leaf of 1% (w/v) (10.69±5.06 µmol/min/mg), 4% (w/v), (0.079±0.03 µmol/min/mg), and 5% (w/v) (9.11±8.47 µmol/min/mg) of PEG- treated seedlings, respectively. Meanwhile, the highest CAT, POD, and APX activities in the roots were determined in 3% (w/v) (0.49±0.04 µmol/min/mg), 2% (w/v) (0.03±0.02 µmol/min/mg), and 3% (w/v) (16.69±0.5 µmol/min/mg) of PEG-treated seedlings, respectively. These data show that PEG can be a priming agent to induce defense system at seedling stage of banana, which could enhance their survivability during ex vitro acclimatization.

Eye Blink Artefact Removal of Single Frontal EEG Channel Algorithm using Ensemble Empirical Mode Decomposition and Outlier Detection

Recently, the emergence of various applications to use EEG has evolved the EEG device to become wearable with fewer electrodes. Unfortunately, the process of removing artefact becomes challenging since the conventional method requires an additional artefact reference channel or multichannel recording to be working. By focusing on frontal EEG channel recording, this paper proposed an alternative single-channel eye blink artefact removal method based on the ensemble empirical mode decomposition and outlier detection technique. The method removes the segment of the potential eyeblinks artefact on the residual of a pre-determined level of decomposition. An outlier detection technique is introduced to identify the peak of the eyeblink based on the extreme value of the residual signal. The results showed that the corrected EEG signal achieved high correlation, low RMSE and have small differences in PSD when compared to the reference clean EEG. Comparing with an adaptive Wiener filter technique, the corrected EEG signal by the proposed method had better signal-to-artefact ratio.

Effects of Microbiological and Physicochemical Properties of Cow’s Milk and Goat’s Milk Dadih Inoculated with Various Lactobacillus Species

Dadih is a dairy-based product and it is one of the most popular desserts among Malaysians and Indonesians. It is made from raw milk which naturally contains various types of microorganisms. This study was conducted to develop cultured dadih by inoculating various Lactobacillus species such as Lactobacillus acidophilus, Lactobacillus plantarum and Lactobacillus paracasei into dadih made from cow’s milk and goat’s milk. Prior to isolation of LAB from control dadih (dadih without inoculation with LAB), the dadih was stored at 4˚C for 48 hours. The microbiological (general microbial load, viability of and LAB, mould and yeast count) and physicochemical properties (pH, lactic acid content, total soluble solid, colour, texture and proximate composition) of dadih with different LAB strains and without LAB strain were determined. Results showed that L. paracasei spp. paracasei, Lactobacillus brevis, Lactobacillus casei were isolated from cow’s milk dadih while only L. paracasei spp. paracasei was isolated from goat’s milk dadih. The number of LAB ranged from 5.73 to 6.06 log10 CFU/g for cow’s milk dadih and 5.19 to 5.88 log10 CFU/g for goat’s milk dadih. Results revealed that dadih inoculated with LAB has lower pH and greater amount of lactic acid produced than control dadih. Total soluble solid for dadih with LAB also decreased. Hardness of dadih without LAB culture was higher compared to the inoculated dadih with LAB cultures. Proximate compositions (moisture, ash, crude fat, crude protein and total carbohydrate) showed variations due to differential formulations and incorporations of different LAB strains. Findings showed that L. acidophilus was chosen as the best starter culture for both types of dadih because it has significant effects on pH, titratable acidity, total soluble solid and texture of the dadih.

A Rudimentary X band CW-EPR Spectrometer Based on FPGA

A rudimentary Electron Paramagnetic Resonance (EPR) spectrometer is design using a field programmable gate array (FPGA) equipped with two digital-to-analog (DAC) and two analog-to-digital (ADC) channels. The single stage heterodyne setup operates at X band frequencies and is used to detect EPR signals from 2,2-diphenyl-1-picrylhydrazyl (DPPH) in a loop-gap resonator. We design the loop gap resonator with 3 loops 2 gaps for high field homogeneity and moderate Q-factor. The resonator is coupled capacitively to the coaxial cable and is designed to have an unloaded resonant frequency of 8.856 GHz with a Q-factor of 646.0 when critically coupled. The loaded resonant frequency is reported to be 8.668 GHz with a Q-factor of 615.8. Using this setup, EPR signal is successfully detected at 311.4 mT and 8.688 GHz with an experimental g-factor of 1.99450.0012, which is very near to the standard value for DPPH.

Empirical Correlation of Emulsion Size Prediction for Zinc Extraction Using Flat Blade Impeller System in Emulsion Liquid Membrane Process

In this study, determination of droplets in the presence of blended mixture of surfactants (Span 80 and Tween 80) and nanoparticles, iron (III) oxide (Fe2O3) were investigated using a single stage mixer-settler extractor with 4-pitched flat blade impeller on one shaft employment. Additionally, the influence of Fe2O3 and blended surfactant mixture of Span 80 and Tween 80 on the dispersion of emulsion in terms of Sauter diameter (D32) measurement was compared with new correlations. Results indicate that the presence of Fe2O3 in the blended mixture of surfactant simultaneously decreased in D32 by 79 % and the stability of the emulsion system was enhanced. Overall, empirical correlation for droplet size at different conditions are obtained, and the modified correlation for D32 is presented. The correlation found is D32/DI =0.02265(3.419Φi−1)We-0.6. The calculated average absolute relative deviation (%AARD) is 2.69 %, thus indicating a good accuracy and acceptability between the presented correlation and experimental data.