No abstract

Oil palm agriculture has become one of the economic mainstays for biodiversity-rich countries in the tropics. The conversion of native forests to oil palm monoculture plantation has caused unprecedented biodiversity loss in Southeast Asia. Little is known about the effects of oil palm polyculture farming on arthropod diversity. In this study, arthropods were sampled using pitfall traps at 120 sites in Peninsular Malaysia. We examined how arthropod biodiversity responded to different oil palm farming practices and local-scale vegetation structure characteristics. We found that the number of arthropod orders was significantly greater in polyculture than monoculture smallholdings. However, we did not detect a significant difference in arthropod order composition nor abundance between monoculture and polyculture practices. In situ habitat characteristics explained 16% of the variation in arthropod order richness, with key predictor variables including farming practice, height of oil palm stands, and number of immature palm. The findings of this study suggest that polyculture farming together with management for in situ habitat complexity may be a useful strategy in supporting biodiversity within in oil palm plantations.

This paper discussed on the design and analysis of a permanent magnet generator (PMG). Basically, the PMG is a slot-less type topology and operated in a single-phase. The flux direction in the air gap is in radial. It was developed for energizing the linear motor in pruner application. Due to this application, a compact generator that can produce 500W output power is required since the overall size of the PMG is important. Permeance Analysis Method (PAM) and Finite Element Method (FEM) were used to analyzed the PMG performance characteristic in addition of measurement of the PMG prototype. Various numbers of poles and rotor size were considered during this analysis. The results show that the slot-less PMG with stator size of 104 mm will produce maximum power of 650 W when it has 6-poles with rotor radius is 37 mm. Based on the results, the calculation method using PAM shows good agreement with measurement and simulation.

1 In many developing countries, commercial oil palm farming supports the livelihood of millions of small-scale farmers in the rural areas. However, forest conversion into oil palm monocultures has a major impact on tropical biodiversity. In existing oil palm production landscapes, little is known about how different oil palm agricultural practices affect farmland biodiversity, particularly insect biota. 2 We quantified fruit-feeding butterfly species richness and community composition in oil palm areas subject to polyculture and monoculture farming in Peninsular Malaysia.Polyculture smallholdings were predicted to support greater butterfly diversity than monoculture smallholdings because of the greater structural complexity and floristic diversity associated with crop diversity in polyculture smallholdings. 3 We also identified local-scale habitat attributes important for maintaining fruit-feeding butterfly species richness. 4 We found no significant differences in butterfly species richness, abundance and the composition of butterfly assemblages between polyculture and monoculture smallholdings. Local-scale habitat quality explained 32.1% of the variation in fruit-feeding butterfly richness in oil palm smallholdings. 5 We found that polyculture farming failed to increase fruit-feeding butterfly diversity as a result of a limited number of crop species in oil palm smallholdings. To improve current agricultural practices and maintain high levels of butterfly diversity, commercial growers should increase the number of crop species planted in oil palm smallholdings.

nkjet printing has proven to be a promising and flexible process methodology for low cost and drop-on-demand pattern formation in small-scale devices with a functional material. In this paper, micro droplet deposition using 80 micron diameter nozzle with micro piezoelectric printhead was investigated using a mixture of three fluids, distilled water (DW) and solutions of two different percentage of glycerine (G) as an operating fluids. The droplet formation capability and stability was studied according to the influence of pulse amplitude, dwell time and fluid viscosity. The results show that the optimal drop velocity to obtain a stable printing range from 0.5 ~1.5 ms-1 which corresponds to pulse amplitude range of 25 to 100V and dwell time 15 to 35 μs. Respectively droplet formation and dispensing performance give benefit in dispensing application and build a solid background to inkjeting functional polymer material.