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1

System Design for Evenness Measurement of Raw Silk

Pan Q., Chen M., Hu Y., Zuo B.

Fibres & Textiles in Eastern Europe

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2018

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Vol. 26, no. 1 (127)

21--24

EN

The evenness of raw silk is one of its most valuable qualities. Seriplane inspection is a common test for raw silk evenness but is prone to human error and lacks accurate repeatability; the Uster evenness tester is another common approach but is costly and vulnerable to environmental factors. An image-based raw silk evenness detection system is proposed in this paper. The system is comprised of an image acquisition segment with a CCD image sensor, telecentric lens, light source, over feeding device, and raw silk winding device, plus an image processing segment tasked with threshold segmentation and morphology operations. Images of the raw silk are first captured with the image acquisition segment, then the images are processed by threshold segmentation and morphology processing; the diameters obtained in this segment are then used to calculate the variation coefficient (CV), which characterises the evenness of the raw silk. We conducted three experiments to test the stability, repeatability, and accuracy of the system. The results showed that the system proposed is stable, repeatable, and accurate.

PL

Równomierność surowego jedwabiu jest jedną z jego najcenniejszych zalet. Dotychczas powszechnie stosowane systemy kontroli równomierności jedwabiu są podatne na błąd człowieka i nie mają dokładnej powtarzalności, są kosztowne i wrażliwe na czynniki środowiskowe. W artykule zaproponowano system oceny równomierności jedwabiu oparty na analizie obrazu. Zaproponowany system składa się z segmentu akwizycji obrazu z przetwornikiem obrazu CCD, soczewką telecentryczną, źródłem światła, urządzeniem nadawczym i urządzeniem do nawijania surowego jedwabiu oraz segmentu przetwarzania obrazu, którego zadaniem jest progowa segmentacja i operacje morfologiczne. Obrazy surowego jedwabiu są najpierw przechwytywane przez segment pozyskiwania obrazu, następnie obrazy są przetwarzane przez segmentację progową i przetwarzanie morfologiczne; średnice uzyskane w tym segmencie są następnie wykorzystywane do obliczenia współczynnika zmienności (CV), który charakteryzuje równomierność surowego jedwabiu. Analiza otrzymanych wyników pokazała, że zaproponowany system jest stabilny, powtarzalny i dokładny.

2

Al-doped ZnO films deposited by magnetron sputtering: effect of sputtering parameters on the electrical and optical properties

Pan Q., Song X.

Materials Science Poland

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2017

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Vol. 35, No. 2

374--381

EN

Aluminum-doped zinc oxide (AZO) thin films were prepared by magnetron sputtering method. The influences of deposition pressure, substrate temperature, Ar flow rate and film thickness on optical and electrical properties were investigated using ultraviolet-visible (UV-Vis) spectrometer and Hall measurements. The experimental results revealed that a low resistivity, smaller than 4 × 10-4 Ω·cm, was obtained when the deposition pressure was smaller than 0.67 Pa and substrate temperature about 200 °C. Ar flow rate had a small influence on the resistivity but a big influence on the transparency at near infrared range (NIR). We obtained optimized AZO thin films with high ponductivity and transparency at low deposition pressure, small Ar flow and appropriate temperature (around 200 °C). The etching behavior of the AZO thin films deposited at the different Ar flow rates was also studied in this paper. The results show that Ar flow rate is a very important factor affecting the etching behavior.

3

A management on mesh modelling for finite element analysis in casting simulation

Cho C., Kim W., Choi B., Kwak S., Pan Q.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

335-338

EN

Purpose: In this paper we present a finite element mesh management technique applied to analyze thermal stress distribution of mushy region including molten materials and solidifying shell. Design/methodology/approach: In this study we terminated and eliminated the finite elements representing molten materials on the element list. When they became cooler than the liquidus temperature, the deleted elements were recreated. Findings: We considered temperature-dependent material properties during simulation and adopted hybrid FDM/FEM method for enhancing accuracy: We validated the proposed technique by comparing with other methods. As results, the proposed method is found to effectively simulate real-time casting process. Research limitations/implications: The resulting simulation of conventional methods should induce errors on estimating residual stress of the cast subjected to non-uniform cooling. For the stress analysis study of casting process before complete solidification, we introduce a special technique to treat molten parts in the numerical procedure. This study proposes a method reducing by several orders the elastic modulus of molten material through employing a reduction factor. Practical implications: Conventional casting process simulations don't consider stress due to complex rheological behavior of molten metals until the cast completely solidifies. Achieving uniform cooling rate in a whole cast body while solidifying must be an ideal casting process to avoid undesirable thermal distortion and stress in product which may induce hot tear and crack. Conventionally many prototyping tests should be conducted to this end and necessitate expensive costs. Originality/value: In this study we propose a new technique of "Element Creation and Termination" which terminates (or removes) molten elements and creates them just after they cool down to lower than liquidus temperature. Notice that the previous methods do not remove but deactivate molten elements.