Monitoring multivariate process variability when sub-group size is small

The current practice of multivariate process variability monitoring, when sub-group size is small, has nothing to do with probability of false alarm (PFA). Consequently, the reliability of the existing control charts remains undetermined. In this article, we propose a control chart which is reliable, very sensitive to the change in variance for small or moderate correlation, and provides a root causes analysis of an out-of-control signal. To illustrate these advantages, an industrial example is presented and the results are compared with those issued from the existing methods.     

Development of 1D model for the analysis of heat transport in cylindrical micro combustors

A 1D flame model was developed to analyze the heat transport occurring in the cylindrical micro combustors. The one-step global reaction mechanisms were employed for three fuel–air mixtures (H₂–air, CH₄–air and C₃H₈–air) to account for the difference of fuel property in terms of the kinetics. The effects of various parameters such as the combustor size, fuel property, fuel–air equivalence ratio and unburned mixture temperature on the heat loss ratio (defined as Q_l/Q_in) and the heat recirculation ratio (defined as Q_recir/Q_l) were investigated. The results indicated that these parameters have significant effects on the two ratios, and therefore should be carefully managed in order to achieve efficient and stable combustion. After comparing the results of different fuel–air mixtures, it is concluded that hydrogen is superior to methane and propane as the fuel for micro combustion engines owing to its higher flame temperature and thinner flame thickness, which favors the reduction of heat loss from the flame zone.     

Using tchebichef moment for fast and efficient image compression

Orthogonal moment is known as better moment functions compared to the non-orthogonal moment. Among all the orthogonal moments, Tchebichef Moment appear to be the most recent moment functions that still attract the interest among the computer vision researchers. This paper proposes a novel approach based on discrete orthogonal Tchebichef Moment for an efficient image compression. The image compression is useful in many applications especially related to images that are needed to be seen in small devices such as in mobile phone. Meanwhile, the method incorporates simplified mathematical framework techniques using matrices, as well as a block-wise reconstruction technique to eliminate possible occurrences of numerical instabilities at higher moment orders. In addition, a comparison between Tchebichef Moment compression and JPEG compression is conducted. The result shows significant advantages for Tchebichef Moment in terms of its image quality and compression rate. Tchebichef moment provides a more compact support to the image via sub-block reconstruction for compression. Tchebichef Moment Compression is able to perform potentially better for a broader domain on real digital images and graphically generated images.     

Optimization of Photovoltaic Reflector System for Indoor Energy Harvesting

This study proposes a solution for optimizing the distance between a solar module and reflector for an indoor energy harvesting system. It is a process in which energy(ambient light) is captured and converted directly into electricity. Inside a building, this energy could be used to supply power to wide range of portable equipment or offset other electrical energy usage and associated costs. The proposed reflector element was designed and tested in a real indoor environment to confirm its effectiveness. A distance-optimization method for the placement of a polycrystalline photovoltaic (PV) module and a mirror was described, and the performance characteristics of the system were investigated qualitatively through visual observation and quantitatively through measuring voltage and ampere values. The solar PV system with a reflector element displayed a 10% increase in voltage when compared with that without. As the distance between PV module and the reflector increased, the voltage and ampere reading decreased, thus the distance was optimized to gain maximum readings. Various studies employing reflectors have also showed increases in voltage readings with different designs, suggesting that reflectors are economically viable optical elements that can boost the voltage output of a PV module. In practice, the distance-optimized PV module can be placed in buildings with extended indoor lighting duration away from disrupting building activity.     

Kinetics of aspartame precursor synthesis catalysed by Pseudomonas aeruginosa elastase

Elastase isolated from Pseudomonas aeruginosa IFO 3455 was found to be an efficient protease to catalyse the synthesis of N-benzyloxycarbonyl-aspartyl-phenylalanine methyl ester, the precursor of the dipeptide sweetener, aspartame. The influence of methanol as a cosolvent in this synthetic reaction was investigated. It was found that the synthesis of the dipeptide precursor was most efficient in 25% (v/v) methanol, pH 7·0 at about 25°C for a reaction time of about 3 h. However, the activity of the enzyme was greatly reduced in 90% methanol. The values of K and k₂ for N-benzyloxycarbonyl-aspartic acid were 0·17 mol dm^?3 and 11·9 mol dm^?3 s^?1 respectively.     

Formulation and Characterization of Novel Nanostructured Lipid Carriers with Photoprotective Properties Made from Carnauba Wax,Beeswax, Pumpkin Seed Oil,and UV Filters

Pumpkin seed oil (PSO) with carnauba wax and beeswax was used to develop nanostructured lipid carriers (NLC) loaded with a UV filter, Uvinul® A Plus B. The aims of the study were to optimize the concentration of PSO to develop a stable NLC formulation, determine storage stability of the NLC with and without PSO, and the synergistic effect of PSO-NLC with UV filter for photoprotective properties. The physical properties of NLC were optimized based on the mean particle size, polydispersity index, and storage stability. The optimized NLC consisted 10% lipid phase (3.5% carnauba wax, 3.5% beeswax, and 3.0% PSO) and 90% aqueous phase. After optimization, Uvinul® A Plus B was added in the optimized PSO-NLC to produce a photoprotective formulation. Uvinul® A Plus B consisted of both UVA (Diethylamino Hydroxybenzoyl Hexyl Benzoate) and UVB (Ethylhexyl Methoxycinnamate) filters. The NLC produced with PSO and Uvinul® A Plus B had mean particle size of 135 ± 2 nm and showed good physical stability under storage time. Besides that, the NLC produced also proven to have positive effect in enhancing the entrapment efficiency and drug loading, which were 82.86 ± 0.15% and 55.41 ± 0.04%, respectively, and showed sun protection factor value of 16.61 ± 3.45. The results indicated the presence of synergistic effect among the PSO-NLC with Uvinul® A Plus B.     

Novel Nanostructured Lipid Carriers with Photoprotective Properties Made from Carnauba Wax,Beeswax, and Kenaf Seed Oil

This study was aimed to produce a stable kenaf seed oil-nanostructured lipid carrier (KSO-NLC) sunscreen, which can help in the photoprotective effect. The nanostructured lipid carrier (NLC) formulation was optimized and selected based on the results of mean particle size, polydispersity index (PDI), and storage stability of formulas at both chilled (4 ± 2 °C) and room (25 ± 2 °C) temperatures. Uvinul A plus B was added to KSO-NLC with the optimized formula (80% w/w aqueous phase, 20% w/w lipid phase, and 7% w/w of surfactants with a ratio of 70:15:15 of Tween 20: poloxamer 188: lecithin). The mean particle size distribution (224.73 ± 1.56 nm) and PDI (0.41 ± 0.01) of KSO-NLC were determined and were found to be stable against storage without creaming or phase separation. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical-scavenging activities of KSO-NLC were 5.43 ± 1.00 mg Trolox equiv. g⁻¹ of NLC and 6.70 ± 0.31 mg Trolox equiv. g⁻¹ of NLC, respectively. The Sun Protection Factor (SPF) of KSO-NLC, 41.38 ± 6.03 with a UVA/UVB ratio 0.64 ± 0.01, suggested a good photoprotective effect. The sustained release of Univul A plus B from KSO-NLC accompanied by its entrapment efficiency up to 64.09 ± 0.98% and drug loading (DL) of 32.05 ± 0.49% (maximum 50% DL capacity) proved that the degradation of the ultraviolet (UV) filter could be reduced. Therefore, the KSO-NLC sunscreen was a feasible solution for the photoprotective approach by using unconventional plant seed oil with a significant enhancement (P < 0.05) in many aspects compared to the formula without KSO incorporation.     

The relationships between gas production and chemical composition of 23 browses of the genus Sesbania

This study evaluated the differences in the gas produced by Sesbania accessions and related gas production to macro-constituents and tannin content of the browse species. Fresh samples were incubated in triplicate (about 200 mg per syringe) in a medium prepared from sieved rumen liquor harvested from two rumen-fistuiated cows fed native pasture hay ad libitum and 2.0 kg cottonseed cake per head per day. Sesbania species had similar rates of gas production but differed (P < 0.001) in the volume of gas produced. The ranking order for gas production was S grandiflora > S sesban > S keniensis > S goetzei. There was little variation in the gas production parameters within S grandiflora and S goetzei. But the variation was large within S sesban. Regression analysis showed that the rate of gas production was negatively affected (P < 0.025) by the lignin content of the browses, but the volume of gas produced was negatively related to the neutral detergent fibre, hemicellulose, lignin and insoluble proanthocyanidins content of browses. Ouster analysis showed a broad agreement between gas production constants, macro-constituents and tannin contents in classifying accessions into high or low nutritive value groups.     

Multilingual sentiment analysis: from formal to informal and scarce resource languages

The ability to analyse online user-generated content related to sentiments (e.g., thoughts and opinions) on products or policies has become a de-facto skillset for many companies and organisations. Besides the challenge of understanding formal textual content, it is also necessary to take into consideration the informal and mixed linguistic nature of online social media languages, which are often coupled with localised slang as a way to express ‘true’ feelings. Due to the multilingual nature of social media data, analysis based on a single official language may carry the risk of not capturing the overall sentiment of online content. While efforts have been made to understand multilingual sentiment analysis based on a range of informal languages, no significant electronic resource has been built for these localised languages. This paper reviews the various current approaches and tools used for multilingual sentiment analysis, identifies challenges along this line of research, and provides several recommendations including a framework that is particularly applicable for dealing with scarce resource languages.     

A comparative study between intermittent microwave and infrared drying of bioproducts

A systematic experimental study of both intermittent microwave (MW) and infrared (IR) drying was used to compare the efficacy of the two methods when batch drying two bioproducts, namely potato and carrot. The controllable parameters examined in this study were MW power and IR intensity level, MW and IR intermittencies and the transition period from convective to MW drying. A comparison of the drying kinetics showed intermittent MW drying to be an effective method for shortening the drying time that was required to reach a certain moisture content when it was compared with intermittent IR drying and convective‐MW drying. A comparison of the colour degradation of the product showed that step variation of the IR intensity during intermittent drying reduced the colour change of the product less than constant radiative intermittent IR drying.