Authenticity green coffee bean species and geographical origin using near-infrared spectroscopy combined with chemometrics

To prevent the adulteration of agricultural resources and provide a solution to enhance the green coffee bean supply chain, authentication using the near-infrared spectroscopy (NIRS) technique was investigated. Partial least square with discrimination analysis (PLS-DA) models combined with various preprocessing methods were built from NIR spectra of 153 Vietnamese green coffee samples. The model combined with the standard normal variate and the first order of derivative yielded excellent performance in predicting coffee species with the error cross-validation of 0.0261. PLS-DA model of mean centre and first-order derivative spectra also yielded good performance in verifying geographical indication of green coffee with the error of 0.0656. By contrast, the predicting abilities of post-harvest methods were poor. The overall results showed a high potential of the NIRS in online authentication practices.     

Smartphone-based bulky waste classification using convolutional neural networks

Multimedia Tools and Applications - The rapid urbanization process is escalating the urban waste problem, and ineffective management has worsened the issue, leading to severe consequences to the...     

Experimental and Modeling Studies on the Chemical Vapor Infiltration with Respect to the Effects of Thermal Gradient and Other Operating Parameters

Effects of operating parameters in the thermal gradient chemical vapor infiltration of propane such as thermal gradient, diffusion, infiltrations time, and concentration of propane were studied by focusing on the visualizations of the intrinsic effects of these parameters. A uniform deposition in the preform was obtained with a gradually increasing temperature along the gas flow. The uniformity of deposition through the preform got improved with increasing deposition time. Results of numerical modeling estimated the experimental data very well when the pre-exponential factor of the overall rate of carbon deposition from propane reported by Vaidyaraman[1] was multiplied by 4. The average density of a preform increased by about 3 times from 0.38 to 1.15 g/cm3 after 60 hr deposition with a thermal gradient under the conditions of 3% propane in nitrogen and 840 to 900 ℃.     

下荆江熊家洲至城陵矶弯曲型河段河床调整规律

三峡水库运用后, 坝下游水沙过程发生了较大调整, 对下荆江熊家洲至城陵矶弯曲型河段河床冲淤演变造成较大影响, 从而对本河段河势稳定、防洪、航运等可能造成不利的影响, 基于此, 根据最新实测资料分析水沙条件变 化及其对本河段河床调整规律的影响。研究成果显示: 三峡水库运用后, 水流含沙量大幅减小, 且水库调蓄导致熊 家洲至城陵矶河段在枯水期径流量明显增加, 使弯道主流长期偏向于凸岸, 引起凸岸边滩大幅冲刷, 这是近期该河段发生“撇弯切滩”的主要原因之一; 随着三峡上游干支流水库群陆续建成运用, 坝下游河道将会长期遭受清水冲 刷, 河床仍将呈单向冲刷下切的趋势, 弯顶段主流平面摆动仍将较大, 弯道顶冲点也将相应下移, 导致主流贴岸距离 进一步下延, 引起河道岸线的崩退, 未来一段时期内典型弯曲型河道的局部河势变化仍将明显。     

Optimal Energy Harvesting Strategy in Relaying Networks: Dynamic Allocation Scheme and Performance Analysis

Wireless Personal Communications - This paper evaluates the performance of a wireless powered communications system, where an energy-aware relay can ability of controlling proper energy harvesting...     

Tactile colour pictogram to improve artwork appreciation of people with visual impairments

A recent development in tactile technology enables an improvement in the appreciation of the visual arts for people with visual impairment (PVI). The tactile sense, in conjunction with, or a possibly as an alternative to, the auditory sense, would allow PVIs to approach artwork in a more self‐driven and engaging way that would be difficult to achieve with just an auditory stimulus. Tactile colour pictograms (TCPs), which are raised geometric patterns, are ideographic characters that are designed to enable PVIs to identify colours and interpret information by touch. In this article, three TCPs are introduced to code colours in the Munsell colour system. Each colour pattern consists of a basic cell size of 10 mm × 10 mm to represent the patterns consistently in terms of regular shape. Each TCP consists of basic geometric patterns that are combined to create primary, secondary, and tertiary colour pictograms of shapes indicating colour hue, intensity and lightness. Each TCP represents 29 colours including six hues; they were then further expanded to represent 53 colours. Two of them did not increase the cell size, the other increased the cell size 1.5 times for some colours, such as yellow‐orange, yellow, blue, and blue‐purple. Our proposed TCPs use a slightly larger cell size compared to most tactile patterns currently used to indicate colour, but code for more colours. With user experience and identification tests, conducted with 23 visually impaired adults, the effectiveness of the TCPs suggests that they were helpful for the participants.     

Impact of defects on the decomposition of chemical warfare agent simulants in Zr-based metal organic frameworks

Metal organic frameworks (MOFs) containing zirconium secondary building units (SBUs) in UiO-67 and related MOFs, are highly active for neutralizing both the chemical warfare agents and simulants, such as dimethyl methylphosphonate (DMMP). However, two recent publications gave conflicting reports of DMMP reaction with UiO-67 under ultra high vacuum (UHV) conditions, with one reporting chemisorption and reaction (Wang et al., J Phys Chem C, 2017, 121, 11261–11272) and the other reporting only physisorption and reversible desorption (Ruffley et al., J Phys Chem C, 2019, 123, 19748–19758) from very similar temperature programmed desorption experiments. We show that the discrepancy between these experiments may be explained by different levels of missing linker defects in the UiO-67 samples. We present density functional theory calculations showing that SBU sites having two-adjacent missing linkers exhibit reaction barriers that are about 30 kJ/mol lower than SBU sites having a single missing linker. We also show that topology of the undercoordinated sites plays an important role in the reaction barrier under UHV conditions.     

Quantitative determination of kokumi compounds, γ-glutamyl peptides,in Korean traditional fermented foods,ganjang and doenjang,by LC-MS/MS

Food Science and Biotechnology - Recent studies have shown that γ-glutamyl peptides (GGPs) are recognized by the calcium-sensing receptor and induce kokumi taste. The contents of GGP have been...