Identifikasi Molekuler Rotifer Brachionus SP. Asal Perairan Tumpaan, Minahasa Selatan

Rotifer yang digunakan dalam penelitian ini berasal dari Tumpaan, Minahasa Selatan dan telah dikultur massal selama beberapa generasi. DNA genom rotifer diekstraksi mengikuti prosedur qiagen DNeasy Blood & Tissue kit; amplifikasi gen COI (Cytochrome oxidase sub unit 1) dilakukan dengan bantuan mesin PCR (Polymerase chain reaction) menggunakan primer universal (LCO1490 (forward) dan HCO2198 (reverse));dan dilanjutkan dengan pengurutan nukleotida produk PCR. Pengolahan data hasil sekuens dilakukan dengan menggunakan program ABsequens dan MEGA (Molecular Evolutionary Genetics Analysis) Identifikasi spesies dilakukan dengan menggunakan teknik BLAST (Basic Local Alignment Search Tool) di situs Genbank. Hasil amplifikasi gen COI menggunakan DNA template ekstrak DNA genom rotifer terobservasi adanya pita DNA pada posisi sekitar 700 bp.Kualitas hasil pengurutan nukeotida menggunakan produk PCR menunjukan nilai CRL (contignous read length) dan QV20+(quality value lebih besar dari 20) yang tinggi (>600 nukleotida).Hasil BLAST menunjukkan bahwa rotifer dalam penelitian ini merujuk pada rotifer Brachionus plicatilis complex spesies.Maximum dan total score, prosentase query cover dan prosentase identity masing-masing pada nilai1003-1116, 87-96% dan 96-97%

Physico-chemical and thermal properties of starch derived from sugar palm tree (arenga pinnata)

Petroleum based polymers are extremely stable and commonly used in various industries include food packaging, furniture and automotive. However, the waste that come from petroleum based polymer material has brought negative impact not only for human being, but also create the serious environmental problems. Hence, biopolymers that come from natural source such as starches are now being considered as an alternative to the existing petrochemical based polymers. This study was aimed to examine the potential of sugar palm starch extracted from sugar palm tree (Arenga pinnata) as a new biopolymer. The important properties of sugar palm starch studied were the chemical properties, thermal properties, particle size and morphological surface. The starches isolated from sugar palm tree contained comparable amounts of amylose (37.60 %) which were higher than tapioca, sago, potato, wheat and maize. The results showed significant differences in the chemical content as well as in the granule sizes of sugar palm starch. Thermal characteristic studies using thermogravimetry analysis and differential scanning calorimetry showed that sugar palm starch was thermally stable than other starches. Study on morphological surface indicated that sugar palm starch were rounded and oval-shaped

Development and characterization of sugar palm starch and poly(lactic acid) bilayer films

The development and characterization of environmentally friendly bilayer films from sugar palm starch (SPS) and poly(lactic acid) (PLA) were conducted in this study. The SPS-PLA bilayer films and their individual components were characterized for their physical, mechanical, thermal and water barrier properties. Addition of 50% PLA layer onto 50% SPS layer (SPS50-PLA50) increased the tensile strength of neat SPS film from 7.74 to 13.65MPa but reduced their elongation at break from 46.66 to 15.53%. The incorporation of PLA layer significantly reduced the water vapor permeability as well as the water uptake and solubility of bilayer films which was attributed to the hydrophobic characteristic of the PLA layer. Furthermore, scanning electron microscopy (SEM) image of SPS50-PLA50 revealed lack of strong interfacial adhesion between the SPS and PLA. Overall, the incorporation of PLA layer onto SPS films enhances the suitability of SPS based films for food packaging

A review of gelatin: properties, sources, process, applications, and commercialisation

This review begins with a discussion of the general properties of gelatin and its sources, particularly in the food and health industries, and then briefly address the status quo of gelatin in today’s market. Apart from the basic chemical compounds and gelatin types, this paper also discussed the commercialisation of gelatin. This study also highlights the production of conventional gelatin and its current method of processing, i.e. enzymatic hydrolysis. In addition, the variety of raw materials of collagen is outlined and briefly broached the plant hydrocolloids which have been labeled as ’veggie-gelatin’. With regard to the potential and market stability of gelatin, its recent studies are summarised in this paper. Accordingly, this paper focuses on assessing the general utilities of the various sources of collagen as gelatin derivatives. At that basis, the aim of this review is to provide an insight into gelatin in current applications, market value and progress in gelatin extraction

Development and properties of sugar palm fibre reinforced polymer composites

Natural fibers have recently become attractive as an alternative reinforcement for fiber reinforced polymer composites. They are gaining more attention due to their low cost, easy availability, less health hazards, fairly good mechanical properties, high specific strength, nonabrasive, ecofriendly and bio-degradability characteristics. Polymers from renewable resources have attracted tremendous amount of attention to researchers and engineers over two decades. The increasing appreciation for biopolymers is mainly due to environmental concerns, and the rapid petroleum resources depletion. Sugar palm fiber (SPF) reinforcement of a novel biodegradable sugar palm starch (SPS) has been studied in this chapter. The result shows that the mechanical properties of plasticized SPS improved with the incorporation of fibers. Fiber loading also increased the thermal stability of the biocomposite. Water uptake and moisture content of SPF/SPS biocomposites decreased with the incorporation of fibers, which is due to better interfacial bonding between the matrix and fibers as well as the hindrance to absorption caused by the fibers. It can be seen that tensile strength and impact strength of biocomposites increase with increasing fiber content. This enhancement indicates the effectiveness of the SPF act as reinforcement. SPF reinforcement of epoxy and high impact polystyrene (HIPS) have also been looked into. Overall, SPF treatments enhanced the mechanical properties of both polymers (epoxy and high impact polystyrene). Thus, indicating that SPF has a promising potential to be used as reinforcement in polymer composites

The mechanical performance of sugar palm fibres (Ijuk) reinforced phenolic composites

Sugar palm fibres are one of the natural fibres which have many features and need further study to understand their properties. The aim of this work is to investigate the flexural, compressive and impact properties of sugar palm fibres reinforced phenolic composites. Sugar palm fibres were used as a filler (particle size 150 μm) and with loading of 0, 10, 20, 30, and 40 vol.%. The fibres were treated by sea water and then fabricated into composites by hot press technique. Flexural, compressive, and impact tests were carried out as per ASTM D790, ASTM D695-08a, and ASTM D256 standards, respectively. Scanning electron microscopy (SEM) was used to investigate the morphology and the interfacial bonding of the fibres-matrix in composites. The results show that the mechanical properties of the composites improve with the incorporation of fibres. The composite of 30 vol.% particle loading exhibit optimum values which are 32.23 MPa, 61.66 MPa, and 4.12 kJ/m2 for flexural, compressive, and impact strength, respectively. This was because good compatibility of fibre-matrix bonding. Consequently, sugar palm fibre is one of the prospective fibres and could be used as a potential resource to reinforcement polymer composite

Physical and chemical properties of different morphological parts of sugar palm fibres.

Recently, due to increased environmental concerns, scientists and technologists have placed great importance on the application of natural fibres, especially in biocomposites. The sugar palm tree is one of the most popular natural fibres used in engineering applications. A study on the fundamental properties of fibres from different morphological parts of the sugar palm plant, which are bunch, black sugar palm fibre, locally known as ijuk, trunk and frond was carried out in order to evaluate their potential as eventual raw materials for reinforced polymer composites. From this study, it was found that sugar palm frond (SPF)gives the highest tensile strength compared to the other parts, which is 421.4 N/mm2. The tensile strength for sugar palm bunch (SPB), ijuk and sugar palm trunk (SPT) is 365.1,276.6 and 198.3 N/mm2, respectively. These results have been proven using those for their chemical compositions, where the highest cellulose content was obtained from SPF (66.5%), followed by SPB (61.8%), ijuk (52.3%), and SPT (40.6%). For water absorption testing, it was found that SPF also gave the highest percentage - 132.8%, followed by SPB, ijuk and SPT. Fourier transform infrared (FT-IR) spectroscopy was used in order to detect the presence of functional groups existing in sugar palm fibre

Characteristics of thermoplastic sugar palm starch/agar blend: thermal, tensile, and physical properties

The aim of this work is to study the behavior of biodegradable sugar palm starch (SPS) based thermoplastic containing agar in the range of 10–40 wt%. The thermoplastics were melt-mixed and then hot pressed at 140◦C for 10 min. SEM investigation showed good miscibility between SPS and agar. FT-IR analysis confirmed that SPS and agar were compatible and inter-molecular hydrogen bonds existed between them. Incorporation of agar increased the thermoplastic starch tensile properties (Young’s modulus and tensile strength). The thermal stability and moisture uptake increased with increasing agar content. The present work shows that starch-based thermoplastics with 30 wt% agar content have the highest tensile strength. Higher content of agar (40 wt%) resulted to more rough cleavage fracture and slight decrease in the tensile strength. In conclusion, the addition of agar improved the thermal and tensile properties of thermoplastic SPS which widened the potential application of this eco-friendly material. The most promising applications for this eco-friendly material are short-life products such as packaging, container, tray, etc

On child head injury criteria (HIC) and stress due to frontal fall impact on rigid floor

Head Injury Criteria (HIC) during an accident is an important criterion in car crashworthiness assessment. HIC values for driver, adult occupant and child occupant need to be assessed and their values need to be limited. For child occupant, 1 year old (1YO), 3YO and 6YO dummies are used. In developing the child dummies, respective child age dummy heads are subjected to drop impact at particular point on the head. In this paper, the HIC values for 1, 3 and 6 year-old child heads falling on a rigid floor for -5.5o, 0o, 45o and 90o impact angle and drop heights of 150 mm, 300 mm and 450 mm are presented. Ls-Dyna suite of program was used. The results show that HIC depends on age, drop height and angle of impact. It is also found that, 3YO gives the lowest HIC value with against age at all drop height. This could be due to for 1YO, tissues are weaker and fontanel exist, compared to 3YO, and for 6YO, although the tissues are stronger, it is heavier compared to 3YO that contributes to its higher HIC values

Factorial validity and invariance of the MUET essay writing rating scale: empirical and theoretical correspondence

Purpose – The validity of any performance assessment depends substantially on the rating scale used in the assessment procedure. It delineates the theoretical construct being measured and influences how performances are judged and interpreted. This study examined the factorial validity and invariance of the rating scale used for the assessment of the essay writing component of the Malaysian University English Test (MUET) in terms of the correspondence to empirical data and the theoretical construct of ESL writing. Methodology – To determine the factorial validity of the MUET essay writing rating scale, a measurement model was developed based on the criteria description of the scale. Model-data ft was tested using CFA. The data comprised 392 essays, taken from a university English profciency examination. Factorial invariance was tested through consecutively more restrictive models. Results – A 3-factor structure model was found to produce the best ft to the data. Factorial invariance was tested by examining the comparability of the structure and values of parameters within the model across two groups. A more restrictive model was subsequently tested, where variances and covariances of the latent constructs together with factor loadings were constrained to be equal for the two groups. The resultant goodness-of-ft indices showed a better ft to the data, providing support for the factorial invariance of the 3-factor structure model. Significance – The results support a 3-factor structure model,congruent with the theory of ESL writing. However, further validation needs to be carried out across different ESL populations to ensure accurate representation and assessment of ESL writing performance