Ultrasonic songs and stridulum anatomy of Asiophlugis crystal predatory katydids (Tettigonioidea: Meconematinae: Phlugidini)

The behavioural ecology of ultrasonic-singing katydids is not well understood, and the general bioacoustics, barely known for a few Neotropical Meconematinae, tends to be overlooked for species from Southeast Asia. These include Asiatic species of Phlugidini, commonly known as crystal predatory katydids. One of its genera, Asiophlugis consists of 16 species for which acoustic signals and stridulum anatomy are broadly unknown. These characters can be used to understand species boundaries. Here, we sampled Asiophlugis from five sites in Malay Peninsula and Borneo Island, recorded the acoustic signals of five species plus one subspecies using ultrasound sensitive equipment, and examined their stridulum anatomy. The calling songs of the taxa involved were documented for the first time. We found that the stridulum anatomy (e.g., tooth distributions, tooth length and tooth density) is distinct between species but less so between subspecies. In contrary, songs of different taxa are different based on acoustic parameters (e.g., pulse duration, peak frequency) and descriptive patterns, even between the subspecies. We also did not observe that song signals are more different in sympatry than in allopatry. Whether this can be generalised requires further sampling, highlighting the need for more research on the ultrasonic acoustic communication in Asiatic katydids

Optimización de la cristalización con metanol para una separación altamente eficiente del ácido palmítico en mezclas de ácidos grasos de palma usando metodología de superficie de respuesta

The objective of the current study was to develop parameters for the separation of palmitic acid (PA) from a crude palm oil saturated fatty acid (SFAs) mixture by using the methanol crystallization method. The conditions of methanol crystallization were optimized by the response surface methodology (RSM) with the D-optimal design. The procedure of developing the solvent crystallization method was based on various different parameters. The fatty acid composition was carried out using a gas chromatography flame ionization detector (GC-FID) as fatty acid methyl esters. The highest percentage of SFAs was more than 96% with the percentage yield of 87.5% under the optimal conditions of fatty acids-to-methanol ratio of 1: 20 (w/v), the crystallization temperature of -15 °C, and the crystallization time of 24 hours, respectively. The composition of separated SFAs in the solid fraction contains 96.7% of palmitic acid (C16:0) as a dominant component and 3.3% of stearic acid (C18:0). The results showed that utilizing methanol as a crystallization solvent is recommended because of its high efficiency, low cost, stability, availability, comparative ease of recovery and its ability to form needle-like crystals which have good filtering and washing characteristics.El objetivo del presente estudio fue desarrollar parámetros para la separación de ácido palmítico (PA) en mezclas de ácidos grasos saturados (SFAs) de aceites de palma crudo mediante el método de cristalización con metanol. Las condiciones de cristalización con metanol se optimizaron utilizando la metodología de superficie de respuesta (RSM) con el diseño D-Optimal. El procedimiento de desarrollo del método de cristalización con disolvente se basó en diversos parámetros diferentes. La composición de ácidos grasos se llevó a cabo por cromatografía de gases (GC-FID) como ésteres metílicos de ácidos grasos usando un detector de ionización de llama. El porcentaje más alto de SFAs fue mayor del 96% con un rendimiento porcentual de 87,5% bajo las condiciones óptimas de relación de ácidos grasos:metanol de 1:20 (p/v), una temperatura de cristalización de -15ºC y un tiempo de cristalización de 24 horas. La composición de la fracción de SFAs separada en fracción sólida contiene 96,7% de ácido palmítico (C16:0) como principal componente y 3,3% de ácido esteárico (C18:0). Los resultados mostraron recomendar metanol como disolvente de cristalización debido a su alta eficiencia, bajo coste, estabilidad, disponibilidad, facilidad comparativa de recuperación y su capacidad para formar cristales de aguja que tienen buenas características de filtración y lavado

Optimization of methanol crystallization for highly efficient separation of palmitic acid from palm fatty acid mixture using response surface methodology

The objective of the current study was to develop parameters for the separation of palmitic acid (PA) from a crude palm oil saturated fatty acid (SFAs) mixture by using the methanol crystallization method. The conditions of methanol crystallization were optimized by the response surface methodology (RSM) with the D-optimal design. The procedure of developing the solvent crystallization method was based on various different parameters. The fatty acid composition was carried out using a gas chromatography flame ionization detector (GC-FID) as fatty acid methyl esters. The highest percentage of SFAs was more than 96% with the percentage yield of 87.5% under the optimal conditions of fatty acids-to-methanol ratio of 1: 20 (w/v), the crystallization temperature of -15 °C, and the crystallization time of 24 hours, respectively. The composition of separated SFAs in the solid fraction contains 96.7% of palmitic acid (C16:0) as a dominant component and 3.3% of stearic acid (C18:0). The results showed that utilizing methanol as a crystallization solvent is recommended because of its high efficiency, low cost, stability, availability, comparative ease of recovery and its ability to form needle-like crystals which have good filtering and washing characteristics

Ultrasonic songs and stridulum anatomy of Asiophlugis crystal predatory katydids (Tettigonioidea: Meconematinae: Phlugidini)

The behavioural ecology of ultrasonic-singing katydids is not well understood, and the general bioacoustics, barely known for a few Neotropical Meconematinae, tends to be overlooked for species from Southeast Asia. These include Asiatic species of Phlugidini, commonly known as crystal predatory katydids. One of its genera, Asiophlugis consists of 16 species for which acoustic signals and stridulum anatomy are broadly unknown. These characters can be used to understand species boundaries. Here, we sampled Asiophlugis from five sites in Malay Peninsula and Borneo Island, recorded the acoustic signals of five species plus one subspecies using ultrasound sensitive equipment, and examined their stridulum anatomy. The calling songs of the taxa involved were documented for the first time. We found that the stridulum anatomy (e.g., tooth distributions, tooth length and tooth density) is distinct between species but less so between subspecies. In contrary, songs of different taxa are different based on acoustic parameters (e.g., pulse duration, peak frequency) and descriptive patterns, even between the subspecies. We also did not observe that song signals are more different in sympatry than in allopatry. Whether this can be generalised requires further sampling, highlighting the need for more research on the ultrasonic acoustic communication in Asiatic katydids

Comparison of Insect Assemblages (butterfly, dragonfly and moth) in Different Lowland Forest Types in Sabah, Malaysia

A comparative study on butterfly, dragonfly and moth assemblages was conducted in different lowland forest types (mangrove, plantation and dipterocarp forests) in Sandakan, eastern Sabah. The family and species composition of the three insect orders in various sites are highlighted. Highest insect diversity was recorded in the dipterocarp forest, followed by plantation forest and mangrove forest. The variety and abundance of food sources for insects are higher in the dipterocarp forest compared to the other forests due to the higher plant diversity. However, the presence and abundance of host-specific insects depend on the availability of their host plant in the habitat. Of the three insect orders, moth was the most diverse, followed by butterfly and dragonfly in all the study sites. The similarity among species for the three insect orders among the forests was relatively low although they were located within the same district. This could have been affected by the adjacent land-use changes as well as forest fragmentation. Inventories from this study on insect assemblages have identified some species with conservation interest, nature tourism potential and insects that can be detrimental to the habitat. Such information would contribute towards best practices in sustainable forest management in Sabah

Combustion performance and exhaust emission analysis of spent bleaching earth (SBE) oil as burner's fuel

Spent bleaching earth (SBE) is a type of hazardous solid waste generated during the bleaching process of crude palm oil (CPO). Despite years of studies being done on how best to manage the waste, the issue is still largely unsolved and has created massive economic and environmental problems. SBE is generally disposed by dumping onto landfills because it is by far the cheapest method. However, due to the high quantities of water insoluble substance; mostly free fatty acids (FFA) and peroxide as well as heavy metals, the waste decomposes very slowly and thus becoming a serious hazard to the environment that can cause water and soil pollution as well as fire risk. Recent breakthrough in studies have allowed significant amount of residual oil contained in SBE to be extracted and this has opened up new avenues to tackle the SBE dumping issue. By extracting the oil, it can be used as an alternative fuel in lieu of fossil fuels in power generation. This will inadvertently create a value added product that can mitigate the environmental hazards of SBE dumping but also reduce the cost of handling and disposing the waste. However, at present the research on SBE is limited to the advancement of residual oil extraction technique. There is no research that focus on the evaluation of SBE oil as a substitute to fossil fuels. As such this paper will evaluate and determine the combustion performance and exhaust emission of SBE oil as a source of fuel for burner. The combustion performance in terms of CO2, CO, NOx and flame temperature will be compared with neat diesel under the same conditions. SBE oil shows some promising combustion performance, since it produces no SOx due to the absence of Sulphur, emits lower CO2 than diesel, while releases higher CO than diesel. The higher amount of CO produced by SBE oil can be largely attributed by the high viscosity of the oil. The high viscosity and density of SBE oil greatly affects the fuel spray which in turns causing a poor atomization and combustion hence the high amount of CO emission