Develop Processing Techniques Research Articles

Effects of pearling on proximate composition, dough rheology, bread-making quality and health-promoting components of elite wheat cultivars

Though the health benefits of whole wheat products have been widely recognized, their less desirable processing qualities limited consumers’ acceptance. Thus, it is imperative to develop processing techniques for balanced nutritional and processing qualities. In this study, we investigated impacts of two grain pearling (debranning) levels on proximate composition, dough rheological properties, food-making quality, arabinoxylans (AXs), alkylresorcinols (ARs) and phenolic acids composition of two elite bread wheat cultivars. Pearled flour (PF) of Zhongmai 175 retained very good dough extensibility (190.7–195.5 mm), while PF of Zhongmai 578 retained medium-to-strong gluten strength and acceptable bread-making quality. Compared to whole wheat flour, PF preserved major portion of the health-promoting components in wheat grains, i.e., 71.4–94.0 % for water-extractable AXs, 68.1–86.3 % for total AXs, 71.4–92.7 % for alkylresorcinols, 85.5–98.9 % for soluble ferulic acid and 67.3–83.3 % for insoluble-bound ferulic acid. Further investigation is needed to understand the effects of different kernel sizes and debranning rates on nutritional profiles of pearled grains. Taken together, our results suggested that grain pearling can be used to produce wheat products with balanced nutritional and processing quality for improved human health.

Case study: 4D consistent receiver coupling corrections applied to deep‐water ocean bottom cable data

ABSTRACTWe develop processing techniques to attenuate S‐wave noise observed on the vertical component while also correcting for poor coupling between sensors and the seabed on deep‐water ocean bottom cable seismic data from offshore Brazil. To study these techniques, we simulate the effects of poor sensor coupling with synthetic ocean bottom cable data by introducing transfer functions that characterize the coupling system. Furthermore, by combining surveys from the deep‐water time‐lapse (4 dimensions) seismic project using an interleaving process, we can analyse coupling coefficient changes over time and obtain an S‐wave noise model that is more statistically accurate. This noise model can then be adaptively subtracted from the field data, leading to an improved normalized root mean square between surveys.

Comparison of enhancement techniques based on neural networks for attenuated voice signal captured by flexible vibration sensors on throats

Wearable flexible sensors attached on the neck have been developed to measure the vibration of vocal cords during speech. However, high-frequency attenuation caused by the frequency response of the flexible sensors and absorption of high-frequency sound by the skin are obstacles to the practical application of these sensors in speech capture based on bone conduction. In this paper, speech enhancement techniques for enhancing the intelligibility of sensor signals are developed and compared. Four kinds of speech enhancement algorithms based on a fully connected neural network (FCNN), a long short-term memory (LSTM), a bidirectional long short-term memory (BLSTM), and a convolutional-recurrent neural network (CRNN) are adopted to enhance the sensor signals, and their performance after deployment on four kinds of edge and cloud platforms is also investigated. Experimental results show that the BLSTM performs best in improving speech quality, but is poorest with regard to hardware deployment. It improves short-time objective intelligibility (STOI) by 0.18 to nearly 0.80, which corresponds to a good intelligibility level, but it introduces latency as well as being a large model. The CRNN, which improves STOI to about 0.75, ranks second among the four neural networks. It is also the only model that is able to achieves real-time processing with all four hardware platforms, demonstrating its great potential for deployment on mobile platforms. To the best of our knowledge, this is one of the first trials to systematically and specifically develop processing techniques for bone-conduction speed signals captured by flexible sensors. The results demonstrate the possibility of realizing a wearable lightweight speech collection system based on flexible vibration sensors and real-time speech enhancement to compensate for high-frequency attenuation.

The effects of metal particle size and distributions on dimensional accuracy for micro parts in micro metal injection molding

This study aims to develop processing techniques to improve dimensional accuracy of micro-size parts produced by micro metal injection molding (μ-MIM). Micro dumbbell specimens were molded by a micro injection molding machine, which can monitor the cavity pressure in injection molding process. The effects of particle size and distribution of metal powder on dimensional accuracy of micro dumbbell specimens at both grip parts were investigated. As the results, it is confirmed that the powder properties and sintering conditions to improve the dimensional accuracy of micro-MIM parts.

Molding technology for improvement on dimensional accuracy in micro metal injection molding

This study aims to develop processing techniques to improve dimensional accuracy of fine metal parts produced by metal injection molding. Micro dumbbell specimens were molded by the micro injection molding machine, which monitor the cavity pressure during injection molding. Among various injection molding conditions, the influences of injection volume on the cavity pressure, and dimension of both green compacts and sintered parts were investigated. For dimension control, the importance of monitoring cavity pressure at each shot was verified.

Trends in composite materials: the challenge of single-polymer composites

vation and energy saving may come from our ability to recover, recycle and/or reuse the materials. Consumer consciousness, waste management regulations and environmental legislation are all pushing the manufacturers of raw-materials and end-products to carefully consider the environmental impact of their products at all stages of the life cycle, including ultimate disposal. This scenario obviously involves also composite materials, increasingly used in several industrial sectors. In fact, there is a marked interest to improve the methods for recycling and reusing the existing composites, or to develop new ones intrinsically more suitable to be recycled and reused. In this framework, a great deal of efforts has been expended for the development of the so called ‘single-polymer’ composite (SPC) materials, in which both the reinforcing and the continuous phases are polymers with the same chemical composition. These materials have been also denoted as onepolymer composites, homocomposites, all-(the same) polymer composites, or homogeneity composites. The main advantage of SPCs is that, unlike traditional heterogeneous composites (such as glassor carbon reinforced polymer composites), they can be entirely melted down at the end of the product life for recycling. The first example of this kind of composites was reported by Capiati and Porter in 1975, who introduced the concept of single-polymer composites by successfully preparing polyethylene/polyethylene composites. More recently, the preparation of polypropylene, poly(ethylene-terephthalate), poly(ethylene-naphthalate), and liquid-crystalline copolyesters single-polymer composites has been extensively studied. In most cases, SPCs have been obtained through the so called ‘hot compaction’ technique. The use of temperature and pressure to control the melting of the outer surface layer of polymeric fibres implies that the processing window for the hotcompaction process is quite narrow. Other processing techniques include film or fibres stacking, powder impregnation, solution impregnation, etc. An intriguing challenge for materials scientists and engineers is to explore new materials combinations to extend the processing window and to develop processing techniques sufficiently versatile to be scaled up at an industrial level.

Processing-structure-multi-functional property relationship in carbon nanotube/epoxy composites

The novel properties of carbon nanotubes have generated scientific and technical interest in the development of nanotube-reinforced polymer composites. In order to utilize nanotubes in multi-functional material systems it is crucial to develop processing techniques that are amenable to scale-up for high volume, high rate production. In this research we investigate a scalable calendering approach for achieving dispersion of CVD-grown multi-walled carbon nanotubes through intense shear mixing. Electron microscopy was utilized to study the micro and nanoscale structure evolution during the manufacturing process and optimize the processing conditions for producing highly-dispersed nanocomposites. After processing protocols were established, nanotube/epoxy composites were processed with varying reinforcement fractions and the fracture toughness and electrical/thermal transport properties were evaluated. The as-processed nanocomposites exhibited significantly enhanced fracture toughness at low nanotube concentrations. The high aspect ratios of the carbon nanotubes in the as-processed composites enabled the formation of a conductive percolating network at concentrations below 0.1% by weight. The thermal conductivity increased linearly with nanotube concentration to a maximum increase of 60% at 5 wt.% carbon nanotubes.

2201 マイクロ金属粉末射出成形品の寸法精度向上のための製造技術(S28-1 粉末成形とその評価(1),S28 粉末成形とその評価)

This study aims to develop processing techniques to improve dimensional accuracy of tiny parts produced by micro metal injection molding (μ-MIM). Micro dumbbell specimens were molded by a micro injection molding machine, which can be monitored with the mold pressure in injection process measured at the both side chucking portions. The effects of particle size distribution of stainless steel powders on the mold pressure and dimension in green compacts and sintered bodies were investigated. The reduction of the difference in dimension of chucking parts of micro dumbbell specimens to 5μm was achieved by using the powder undercut below 5μm in particle diameter.