Synthesis and optical properties of europium doped zinc silicate prepared using low cost solid state reaction method

This paper presents a study on synthesis and optical properties of Zn₂SiO₄:1 wt% Eu³⁺ at different heat treatments. The objective of the research is to synthesize Zn₂SiO₄:1 wt% Eu³⁺ phosphor by using low cost solid state reaction method with recycled waste bottle glasses as the silicate source. The X-ray diffraction results showed that the prepared Zn₂SiO₄:1 wt% Eu³⁺ phosphors have a sharp diffraction peak as the heat treatment temperatures were increased from 600 to 1000 °C. Furthermore, the morphology from the Field emission scanning electron microscope analysis were shown the formation of well crystalline samples with dense packed grains due to the increment of heat treatment temperatures. Fourier transform infrared spectra has confirmed the present elements in Zn₂SiO₄:1 wt% Eu³⁺ phosphors while the narrow width of Raman line spectra were observed at temperatures ranging from 700 to 1000 °C indicates good homogeneity and crystallinity of synthesized powders. In addition, the energy band gap of europium doped zinc silicate increased dramatically up to 3.62 eV at temperature of 1000 °C. Photoluminescence measurements has also exhibited the red emission corresponding to the ⁵D₀ → ⁷F₂ (600 nm) when viewed under blue excitation.     

Characterization of Magnesium Orotate‐Loaded Chitosan Polymer Nanoparticles for a Drug Delivery System

The drug release properties of magnesium orotate (MgOr) encapsulated in the chitosan (CS) cavity and the complexation behavior between MgOr and CS were investigated. The MgOr‐loaded CS nanoparticles (MgOrCSNPs) were characterized by differential scanning calorimetry, Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, and scanning electron microscopy with energy‐dispersive X‐ray spectroscopy. MgOr was successfully encapsulated into the CS cavity. Results with 3‐(4,5‐dimethylthiazol‐2‐yl)2,5‐diphenyl tetrazolium bromide indicated that MgOrCSNPs retained their cytotoxic activity against the liver cancer cell line (HepG2) and breast cancer cell line (MCF‐7), and low toxicity against the human cell line (3T3) and human retinal epithelial cell line (ARPE‐19).     

Production of bacterial endoglucanase from pretreated oil palm empty fruit bunch by bacillus pumilus EB3

In this study, endoglucanase was produced from oil palm empty fruit bunch (OPEFB) by a locally isolated aerobic bacterium, Bacillus pumilus EB3. The effects of the fermentation parameters such as initial pH, temperature, and nitrogen source on the endoglucanase production were studied using carboxymethyl cellulose (CMC) as the carbon source. Endoglucanase from B. pumilus EB3 was maximally secreted at 37 degrees C, initial pH 7.0 with 10 g/l of CMC as carbon source, and 2 g/l of yeast extract as organic nitrogen source. The activity recorded during the fermentation was 0.076 U/ml. The productivity of the enzyme increased twofold when 2 g/l of yeast extract was used as the organic nitrogen supplement as compared to the non-supplemented medium. An interesting finding from this study is that pretreated OPEFB medium showed comparable results to CMC medium in terms of enzyme production with an activity of 0.063 U/ml. As OPEFB is an abundant solid waste at palm oil mills, it has the potential of acting as a substrate in cellulase production.     

Potentially probiotic acetic acid bacteria isolation and identification from traditional dairies microbiota

Among probiotics, acetic acid bacteria (AAB) can be used as preservative agents because of their high fermentation and acidification activities. This study aimed to isolate, identify and biologically characterise Acetobacter strains from traditional Iranian dairy products. Acetobacter strains were identified by catalase assay, Gram staining, and combined repetitive sequence‐based PCR [(GTG)₅‐PCR fingerprints] and 16S rDNA gene sequencing. We identified eight strains belonging to four species, including Acetobacter aceti, Acetobacter indonesiensis, Acetobacter cibinongensis and Acetobacter syzygii. The molecular techniques could be used as an effective and rapid alternative tool to identify and characterise dairy‐associated AAB. Primary probiotic assessments, including low pH and high bile salt tolerance tests, antagonistic activity test against pathogens, and antibiotic susceptibility confirmed the probiotic properties of these AAB, particularly A. cibinongensis 34L strain, which was isolated from curd. Therefore, this strain can be introduced as novel candidate probiotics that could be used in the food industry.     

Effect of particle geometry on the properties of binderless particleboard manufactured from oil palm trunk

Experimental binderless composite panels were manufactured using fine particles and strands of oil palm (Elaeis guineensis) trunks. Modulus of rupture (MOR), internal bond strength (IB), dimensional stability, and surface roughness of the panels made with a target density of 0.80 g/cm³ were evaluated. Strand type samples had MOR and IB values of 24.95 and 0.95 MPa, respectively. Corresponding values for the fine particle type samples were 4.04 and 0.49 MPa. Panels made from strands met MOR requirement stated in Japanese Industrial Standard (JIS). Enhanced bonding between strands observed by micrographs taken using scanning electron microscopy (SEM) also supported the findings. However, the samples having fine particles had lower MOR values than minimum requirement listed in JIS. Strand type panels had 41.6% thickness swelling which is only 4.6% lower than that of the panels made from fine particles. It appears that dimensional stability of both types of panels exhibited insufficient results according to JIS. Surface roughness quality of the samples made from fine particles had average surface roughness values comparable to those of panels made in past studies. Based on initial results of this work, raw material from oil palm trunks can have some potential to be used to manufacture binderless panels without using any adhesives. This study revealed that mechanical and physical properties of such experimental panels were influenced by the particle geometry. It would be important to consider possible addition of chemical or wax in the particles to improve their dimensional stability in further studies.