Triple line-scan camera measurement for efficient and accurate narrow-space 3-D scanning with motion estimation.

Vision-based three-dimensional (3-D) shape measurement plays a crucial role in the inspection of vehicles and trains in the field of transportation. Consequently, the demand for more comprehensive narrow-space inspection has become an inevitable necessity and presents a great challenge to conventional vision methods. We propose the following efficient and accurate narrow-space 3-D scanning method based on triple line-scan cameras. First, the structure of coplanar dual line-scan cameras with a narrow reflector is proposed, making it easy for the optical path to enter a narrow space and obtain 3-D shape information. Efficient in-motion measurement with a large field of view is thereby achieved without the worries that often accompany narrow-space constraints. Secondly, an additional line-scan camera is attached to the coplanar dual cameras and creates a time-space constraint in point cloud stitching direction through the triple line-scan camera structure. With an efficient algorithm template including matching and motion estimation, accurate point cloud stitching is ensured. Lastly, point cloud texture mapping and light source optimization are realized. Our experimental results prove that the method realizes low-distortion in-motion reconstruction in narrow space despite motion variation.

Polyvinyl alcohol/kappa-carrageenan-based package film with simultaneous incorporation of ferric ion and polyphenols from Capsicum annuum leaves for fruit shelf-life extension.

Bio-based food packaging materials have elicited growing interests due to their great degradability, high safety and active biofunctions. In this work, by simultaneously introducing the polyphenolic extracts from Capsicum annuum leaves and ferric ion (Fe3+) into the Polyvinyl alcohol/kappa-carrageenan (PVA/κ-carrageenan)-based film-forming matrix, an active package film was developed, with the purpose to improve the food shelf life. The experimental results indicated that the existence of Fe3+ can not only improve the mechanical properties owing to the multiple dynamic coordinated interactions, but also endow the composite films with excellent fire-retardancy. Moreover, the composite films could display excellent UV resistant performance, water vapor/oxygen gas barrier properties and antioxidant activities with the corporation of polyphenols. In particular, the highest DPPH and ABTS radical scavenging capacities for composite film (PC-PLP7 sample) were evaluated to be 82.5 % and 91.1 %, respectively. Higher polyphenol concentration is favorable to the bio-functions of the materials. Benefitting from these features, this novel kind of films with a dense and steady micro-structure could be further applicated in fruit preservations, where the ripening bananas were ensured with the high storage quality. This integration as a prospective food packaging material provides an economic and eco-friendly approach to excavate the high added-values of biomass.

Multiple accounting and driving factors of water resources use: A case study of Shanghai.

Previous research papers on urban water resources accounting were confined to the perspectives of production and consumption, ignoring the perspective of income. This paper proposes a systems framework to analyze the income, production, and consumption-based water uses and underlying driving forces of a city based on the methods of multi-scale input-output analysis and structural decomposition analysis. A case study is performed for Shanghai as a megacity. The results show that the income, production and consumption-based water uses of Shanghai had decreased from 5.70 billion m3, 10.85 billion m3 and 28.45 billion m3 in 2007 to 2.80 billion m3, 6.20 billion m3 and 24.10 billion m3 in 2017, respectively. Domestic imported primary inputs had emerged as an important virtual water supplier of Shanghai and its share of total supply-side water use had increased from 23.92% in 2007 to 42.95% in 2017. Meanwhile, about 46% and 40% of Shanghai's total consumption-based water use had been imported from other Chinese regions and foreign countries in 2017, respectively. It is revealed that trade played an important role in relieving water use pressure in Shanghai. The factors that had increased the uses of water resources in Shanghai include population, per capita value-added, per capita output, final consumption structure, and per capita final consumption. The factors that had reduced the water uses in Shanghai include technology, value added mix, output structure, value added structure, domestic import, commodity mix, and foreign import. It is suggested that in addition to curbing urban water use from the production side, more targeted water-saving measures should be devised from the supply (e.g., restricting loan to heavy water-consuming enterprises) and consumption sides (e.g., encouraging residents to buy low-water products).