Environmental factors can play important roles in influencing waterbird communities. In particular, weather may have various biological and ecological impacts on the breeding activities of waterbirds, though most studies have investigated the effect of weather on the late stages of waterbird breeding (e.g., hatching rate, chick mortality). Conversely, the present study attempts to highlight the influence of weather on the early nesting activities of waterbirds by evaluating a recently established mixed-species colony in Putrajaya Wetlands, Malaysia. The results show that only rainfall and temperature have a significant influence on the species' nesting activities. Rainfall activity is significantly correlated with the Grey Heron's rate of establishment (rainfall: rs = 0.558, p = 0.03, n = 72) whereas both temperature and rainfall are associated with Painted Stork's nesting density (temperature: rs = 0.573, p = 0.013; rainfall: rs = -0.662, p = 0.03, n = 48). There is a possibility that variations in the rainfall and temperature provide a cue for the birds to initiate their nesting. Regardless, this paper addresses concerns on the limitations faced in the study and suggests long-term studies for confirmation.
Microalgae are a promising feedstock for carbon-neutral biofuel production due to their superior cellular composition. Alternatively, oxidative torrefaction has been recognized as a potential thermochemical technique for microalgal solid biofuel upgrading. Herein, by using microalga N. oceanica as a feedstock, several characterizations are adopted for evaluating the potential of oxidative torrefaction towards microalgal solid biofuel production. The oxidatively torrefied microalgae can be upgraded as lignite. After in-depth analysis, significant change in the surface microstructure of oxidatively torrefied microalgae is largely changed (via wrinkle and fragmentation) The hydrophobicity, thermal decomposition, thermal stability, and aromatization of oxidatively torrefied microalgae can be largely enhanced as the oxidative torrefaction severity increase. With the increasing torrefaction temperature, the hydrophobicity of oxidative torrefied microalgae gradually improved. The decomposition of C-2/3/5, and -OCH3, the CO bonds of CH3CO-, and the aromatization occurs via oxidative torrefaction according to the NMR analysis. For XPS analysis, torrefaction operation significantly decreases the carbide carbon and enhances the graphitization. As a result, the thermal stability of oxidatively torrefied microalgae is improved. Conclusively, the information obtained in this study can provide insights into the evaluation of oxidative torrefaction performance and fuel properties of microalgal solid biofuel, which may help accelerate the advancement of oxidative torrefaction industrialization.
Lycopene and total phenolics of pink guava puree industry by-products (refiner, siever and decanter)
were evaluated after steam blanching at selected temperatures and times. Lycopene content was in the order of decanter > siever > refiner (7.3, 6.3 and 1.5 mg/100 g, respectively), and the content of total phenolics was in the order of refiner > siever > decanter (4434.1, 2881.3 and 1529.3 mg GAE/100 g, respectively). Regression coefficients for temperatures (x1) and times (x2) from multiple linear regression models of siever and decanter showed significant (p
A study was carried out to determine the effect of enzyme concentration, temperature and incubation time of bromelain on nitrogen content (NC) and degree of hydrolysis (DH) of hydrolysate from cockle (Anadara granosa) meat wash water. Protein precipitation of cockle meat wash water was conducted at pH 4. The precipitate was then hydrolyzed using bromelain at concentrations of 0.5, 1.5 and 2.5% (enzyme/substrate). The best enzyme concentration was subsequently used to study the effect of incubation temperature at 30, 45 and 60°C. The best temperature was then used to determine the effect of incubation time at 0, 24 and 48 hours. Increasing bromelain concentration from 0 to 2.5% produced an increase in NC and DH. Similarly, increasing the incubation time from 0 to 48 hours also increased the value of NC and DH. However, while the increasing of incubation temperature from 30 to 60°C produced an increase in NC, no significant difference was observed for DH.
We demonstrate a multi-wavelength light source using a semiconductor optical amplifier (SOA) in conjunction with an array waveguide grating (AWG). The experimental results showed more than 20 channels with a wavelength separation of 0.8 nm and an optical signal-to-noise ratio of more than 10 dB under room temperature. The channels operated at the wavelength region from 1530.4 nm to 1548.6 nm, which corresponded to AWG filtering wavelengths with SOA drive current of 350 mA. The proposed light source had the advantages of a simple and compact structure, multi-wavelength operation and the system could be upgraded to generate more wavelengths.
α Cordierite is very important phase in MgO-Al2O3-SiO2 system because of their very outstanding thermal, chemical and electrical properties. In this presents study nonstoichiometry cordierite (MgO:Al2O3:SiO2 = 3:1.5:5) using 2 different initial raw materials ( (i)mixture of pure oxide, and ii) mainly mixture of minerals) were fabricated and compared in terms of phase transformation and physical properties. Cordierite was prepared by glass method at low melting temperature (1350°C). Low melting temperature has resulted in partly crystalline glass which has possesses higher hardness, required longer milling time and result in contamination from grinding media. However, α-cordierite has successfully crystallized and fully densified at 850°C/2h. Activation energy for densification was investigated from thermal expansion coefficient (TCE) results. Other properties that were discussed included thermal properties using DTA/TGA.
Phase composition of calcium phosphate ceramic is a characteristic directly related to the biological response of implants due to the differences in mechanical and biochemical properties of these compounds. The biodegradation rate of biphasic calcium phosphate (BCP) can be controlled by altering the HA to β-TCP ratios. In this study the crystalline phase evolution of BCP synthesized via precipitation from aqueous solution of (NH4)2PO4 titrated into heated solution of Ca (NO3)2 was evaluated. The resulting powder was fabricated into porous scaffold using polyurethane foam method. Bulk powders were sintered from 700 - 1400°C to determine the most significant sintering temperature to obtain a stable and well crystallize BCP phases. The porous scaffolds were then sintered at selected temperature and the effects of various sintering times from 5,7,9,11,13 and 15 h were investigated. Bulk powders were characterized by dilatometer, IR analysis and XRD and porous scaffolds were analyzed by XRD and SEMEdx. RIR method was performed to show that the HA to β-TCP ratios were increased with increasing of sintering time and reached the maximum HA value at 11h. It is found that, the possibilities to manipulate the HA to β-TCP ratios in BCP porous scaffold by just controlling the sintering time of the scaffold without controlling the starting powder characteristics.
CaCu3Ti4O12 was synthesized starting from a solution of TiO2 to which Ca and Cu nitrates were added. Due to the differences in the solubilities of the Ca, Cu and Ti, initial variations from ideal stoichiometry and a high solution pH was necessary to obtain stoichiometric CaCu3Ti4O12 precipitates. As precipitated samples were amorphous with CuO phases observed after drying of the precipitates at 300 oC. CaCu3Ti4O12 phases were observed after heat treatment at 1000 oC. XRD studies show the presence of CuO and TiO2 in addition to the CaCu3Ti4O12 for non stoichiometric samples. Observations under the SEM show the presence of Cu rich and Ti rich phases in addition to the CaCu3Ti4O12.
Environmental factors such as temperature, lighting and noise have very significant impact to workers’ health, safety, comfort, performance and productivity. In an ergonomically design industrial work environment, these factors need to be control at their optimum levels. The main objective of this study is to find the effect of temperature, illuminance and sound pressure level on workers’ productivity in automotive industry. To perform this study a workstation in an automotive component manufacturing was selected as the location of the study. Results of data analysis showed there were relationships between temperature, illuminance and noise on workers’ productivity. Later, the authors’ developed multiple linear equation models to represent the relationships between temperature, illuminance and noise on the workers’ productivity. These multiple linear equation models could be used to predict the production rate for the workstation by referring to the value of temperature, illuminance and noise level.
Supercritical carbon dioxide extraction (SC-CO2) of bioactive flavonoid from Strobilanthes crispus (Pecah Kaca) was performed to study the effects of various parameters such as pressure, temperature and dynamic extraction time on the yield and composition of bioactive flavonoid. The results were also compared with those obtained by conventional Soxhlet extraction in lab conditions. The results from SFE showed that the effect of extraction variables on extraction yields decreased in the following order: pressure, temperature and dynamic extraction time. The extraction pressure played a dominant role in the yield of the sample while the effect of time could be ignored. This study also revealed that both Soxhlet extraction and SC-CO2 extraction can be used to obtain flavonoid compound. Under the optimum conditions, the highest bioactive flavonoid compound content was obtained at 3.98% and eight flavonoid compounds were identified by HPLC.
Cassava chips that exist in the current market have no standardisation and cannot be stacked
nicely into cylindrical container. The objectives of this work are to determine the different dimension of cassava chips produced with different thickness and to develop stackable chips during mass production. Fresh cassava tubers were harvested, washed, peeled and sliced. The thickness measurements used were 1.0 mm, 1.5 mm, 1.75 mm and 2.0 mm and 1.27 mm thickness was measured from commercial potato chips as a controlled sample. Then, it was fried in deep fat fryer with the temperature of 170°C. For each thickness studied, different
numbers of slice (10, 20, 30 and 40 slices) were fried simultaneously. Results showed that there
are 6 shapes of fried chips produced during the frying. To conclude, thickness of the slice and
number of slices fried simultaneously give impact towards the shape of fried chip.
The importance of zeolite surface area and pore volume in adsorption processes has been much reported in literature. In addition to that, structural framework and pore network system may also influence the adsorption capacity and selectivity of methane on zeolite. This paper discusses the characteristics of methane adsorption based on several physical properties of the adsorbents such as surface area, pore volume, pore network system and its interaction with adsorbate. The study, using FTIR spectroscopy showed that the adsorbed methane at room temperature was detected in the FTIR region between 3200 cm–1 – 1200 cm–1. Based on the physical properties of the adsorbents and the FTIR spectra of adsorbed methane, the surface area was not the only factor that determined methane adsorption; in fact the type of pore network system of the adsorbent also affected the interaction, thus affecting the adsorption of methane in zeolite.
The objective of this study was to optimise the extraction conditions for phenolic compounds from limau purut (Citrus hystrix) peels using response surface methodology (RSM). A central composite rotatable design (CCRD) was applied to determine the effects of ethanol concentration (%), extraction temperature (oC), and extraction time (min) on total phenolic content (TPC) from limau purut (Citrus hystrix) peels. The independent variables were coded at five levels and their actual values were selected based on the results of single factor experiments. Results showed that ethanol concentration was the most significant (p
Extraction of lemongrass oleoresin was successfully optimised using Pressurised Liquid Extraction (PLE). Character impact compounds; neral, geranial and geraniol which constituted 72% oleoresin, were monitored during this optimisation study by using GCMSD. Based on maximum extraction of these compounds, the optimised operating conditions for PLE were a temperature of 167°C, a pressure of 1203 psi and a static time of 20.43 min. The quality of PLE extract were compared with conventional extraction methods, hydrodistillation and Soxhlet extraction. The proposed method was found to be better in term of quantity of the targeted character impact compounds.
The emulsifying properties of extracted okra (Abelmoschus esculentus L.) mucilage at different maturity indices (1, 2 and 3) were studied. The okra mucilage was prepared using water extraction method and was determined their viscosity at different temperature (10, 30, 50 and 70°C), water holding capacity (WHC), oil holding capacity (OHC), as well as their emulsion capacity (EC) and emulsion stability (ES). Results found that okra with maturity index 2 produced the highest percentage yield of mucilage (1.46%) and followed by index 1 (1.10%) and index 3 (0.31%) (p
Hempedu bumi (Andrographis paniculata, AP), also known as the king of bitters, is an herb commonly found in Asian communities for medicinal usage. The drying behaviour of AP at temperatures of 40, 50, and 60oC with vacuum pressures of 10 and 30 kPa was investigated in this study. The data were then fitted with semi-theoretical and theoretical thin-layer drying models. The results reveal that the drying time is significantly (p
Changes of physico-chemical properties such as size, weight, moisture content, total soluble solid
(TSS), colour, pH, total acidity and sugar content of red seedless watermelon during storage at room temperature (± 28ºC; 70-80% RH) were investigated. The average weight, diameter and length of red seedless watermelon were 5.94 kg, 22.0 cm and 21.8 cm respectively. The length to diameter ratio was 1.02. The statistical analysis indicated that total soluble solids of fruit decreased significantly (p
Storage study of mengkudu (Morinda citrifolia L.) extract was carried out to determine the effects
of canning and storage period on pH, total polyphenol content, antioxidant activity, intensity of off-odour and aroma acceptance. Uncanned (control) and canned extract were stored for 0, 8, 16 and 24 weeks under room temperature. Results showed canning resulted in a significant (p
Magnesol XL concentration (0.5, 1, 3 and 5%), heating temperature (25, 50, 70 and 90 ˚C) and time (5, 10, 15 and 20 mnt) during purification to the color properties (Lightness L*, redness a* and yellowness b*) of Sardinella lemuru oil were evaluated. Purification using Magnesol XL in any condition effectively increase the L* and a* value but reduced the b* value of the lemuru oil. Highest L* value (96.57) was achieved at the treatment temperature 90 ˚C, 5 % level of Magnesol XL concentration and 5 minutes process. Lowest a* value (more green color) was obtained at treatment 70 ˚C temperature, 5% level of concentration and 15 minutes, then lowest b* value was obtained at treatment 90 ˚C temperature, 5 % concentration and 5 minutes process. All the refined lemuru oil’s result had a hue angle higher than 90˚ representing the light greenish-yellow color.
This study aimed to optimise potential extraction conditions using response surface methodology (RSM) for yielding maximum levels of total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging capacity of henna (Lawsonia inermis) stems. The ranges for selected independent variables, namely acetone concentration (20−90%, v/v), extraction time (10−90 min), and extraction temperature (25−45°C) were identified by screening tests. Optimum conditions obtained for extraction of TPC were 47.0% acetone, extraction time of 47.6 min and extraction temperature of 37.3oC. The result also showed that 75.8% acetone, extraction time of 26.2 min and extraction temperature of 41oC yielded the highest DPPH• scavenging capacity. The optimized extraction conditions have resulted in TPC and DPPH• scavenging capacity of 5232.4 mg GAE/100 g DW and 6085.7 mg TE/100 g DW, respectively which similar to the predicted values. Therefore, RSM has successfully optimized the extraction conditions for TPC and radical scavenging capacity of henna stems.