Aerodynamic Performances of MAV Wing Shapes / N. I. Ismail...[et al.]

In general, there are four common Low Reynolds Number wing’s designs for fixed wing Micro Air Vehicle (MAV) which known as Rectangular, Zimmerman, Inverse Zimmerman and Ellipse wing. However, each wing design produces diverse performance and in fact the aerodynamic comparison study among the wings is still lack. Thus, the objective of this study is to evaluate the basic aerodynamic performance found on Rectangular, Zimmerman, Inverse Zimmerman and Ellipse wing designs with view to find the optimal wing shape for Micro Air Vehicle (MAV) configuration. Here, each design was analysed based on simulation works. The results show that at stall angle, the Ellipse wing has maximum lift coefficient ( ) recorded at 1.12 which is at least 4.33% higher than the other wing designs. Based on drag coefficient ( ) analysis, the Inverse Zimmerman Wing exhibited the lowest minimum drag value at 0.033 which is 8.45% lower than the other wing’s designs. In moment coefficient analysis, the results reveal that the Inverse Zimmerman Wing has produced the steepest curve slope value at -0.36 which is 17.39% higher than the other wings. The aerodynamic efficiency ( ⁄) study has also revealed that Zimmerman Wing recorded the highest ⁄value at 6.80 and at least 1.35% higher than to the other wing. Based on these results, it was concluded that Zimmerman wing has the highest potential to be adopted as MAV wing due to its optimal aerodynamic efficiency

Child and parent outcomes following parent interventions for child emotional and behavioral problems in autism spectrum disorders: A systematic review and meta-analysis

There is growing interest in the development of behavioral parent interventions targeting emotional and behavioral problems in children with autism spectrum disorders. Such interventions have potential to improve a number of child and parental well-being outcomes beyond disruptive child behavior. This systematic review and meta-analysis assesses evidence for the efficacy of behavioral parent interventions for disruptive and hyperactive child behavior in autism spectrum disorders, as well as parenting efficacy and stress. A total of 11 articles from nine randomized controlled trials were included. Sufficient data were available to calculate standardized mean difference and show favorable effects of behavioral parent interventions on parent-reported measures of child disruptive behavior (standardized mean difference = 0.67), hyperactivity (standardized mean difference = 0.31) and parent stress (standardized mean difference = 0.37); effects on parent efficacy are less clear (standardized mean difference = 0.39, p = 0.17). There were insufficient data to explore intervention effects on internalizing behavior in autism spectrum disorders, parenting behaviors, or observational and teacher-reported outcomes, providing important avenues for future research. This review adds to growing evidence of the efficacy of behavioral parent interventions for child behavior and parental well-being in autism spectrum disorders (Prospero: CRD42016033979)

Optimization of Pulsed Nd:YAG Laser Melting of Gray Cast Iron At Different Spot Sizes for Enhanced Surface Properties

This paper presents a laser surface modification process of gray cast iron using different laser spot size with an aims to eliminate graphite phase and achieve minimum surface roughness and maximum depth of molten zone and microhardness properties. The laser processing was conducted using JK300HPS Nd:YAG twin lamp laser source pulse TEM 00 mode, 50 W average power, 1064 nm wavelength and different laser spot sizes of 1.0 mm, 1.2 mm, 1.4 mm and 1.7 mm. Three controlled parameter were peak power (Pp), pulse repetition frequency (PRF) and traverse speed (v). Increasing spot size the parameter setting where peak power is increased and pulse repetition frequency and traverse speed is decreased. The modified surface of laser surface melting was characterized for metallographic study, surface roughness and hardness. Metallographic study and surface morphology were conducted using optical microscope while hardness properties were measured using Vickers scale. Surface roughness was measured using a 2D stylus profilometer. From metallographic study, the graphite phase was totally eliminated from the molten zone and formed white zone. This phenomenon affected hardness properties of the modified surface where maximum hardness of 955.8 HV0.1 achieved. Optimization of laser surface modification was conducted for minimum surface roughness and maximum depth of modified layer and hardness properties. From the optimization, the higher desirability is 0.902. The highest depth of molten zone obtain from spot size 1.4 mm at 132 µm and the highest hardness is 989 HV0.1 at laser’s spot size 1.0 mm. The surface roughness increased when the spot size increased from 3.10 µm to 7.31 µm. These finding indicate potential application of enhanced gray cast iron in high wear resistance automotive components such as cylinder liner and break disc

Measuring product sustainability using fuzzy method

Sustainable conscious product is a product that has little or no impact on the environment during its life cycle. Hence, designing and developing a sustainable product with consideration of three main elements such as environment, social and economic aspects are needed. Within these elements, there are many sub-sustainability parameters need to be considered when sustainability analysis is carried out which include pollution, cost, energy, health, acidification and others. The inclusion of these parameters and the uncertainty data increases the complexity in decision making process with respect to sustainable development as it not only evaluates the current situation but also the prediction and strategic decision for the future. Therefore, a methods and tools are required in assisting the designers and decision makers to develop sustainable product. Hence, this paper presents a developed methodology of product sustainability analysis using fuzzy technique. The fuzzy logic approach is embedded into the evaluation process as it has a capability to handle severe uncertainty and ability to evaluate multi criteria data simultaneously. A case study of automotive components is presented to demonstrate the capability of fuzzy technique in sustainability evaluation

Managing the front office department: staffing issues in Malaysian hotels

This study examined hotel staffing issues with a focus on the front office department. Although there are numerous studies reporting high employee turnover in the hospitality industry, few have examined issues that contribute to this turnover or broader related staffing issues. To address this gap, this study conducted semi-structured interviews with 14 front office managers from hotels with various levels of service in the northern region of Malaysia. Results identified a number of poorly studied issues that contribute to staff turnover. The findings indicate that hotel staff turnover and the consequences for hotel performance are due to a complex series of causal factors. Results may be used by hotel managers in addressing their staffing issues and in improving performance. © 201