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1

Controlled-release urea encapsulated by ethyl cellulose/butyl acrylate/vinyl acetate hybrid latex

Li Y., Zhen D., Liao S., Zhu D., Yang X.

Polish Journal of Chemical Technology

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2018

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Vol. 20, nr 4

108--112

EN

Fertilizer encapsulation through polymer membranes can reduce fertilizer losses and minimize environmental pollution. In this paper, an emulsion of ethyl cellulose (EC)/vinyl acetate (VAc)/butyl acrylate (BA) was successfully prepared by pre-emulsified semi-continuous seed emulsion polymerization. EC/BA/VAc films showed biodegradability. The influence of the EC content on the properties of EC/BA/VAc films was also investigated by DSC, a water absorbency analysis, etc. Controlled-release urea encapsulated by EC/BA/VAc latex was prepared in a film coating machine and conformed to the standards for slow-release fertilizers of the Committee of European Normalization. The release of urea from controlled-release urea encapsulated by EC/BA/VAc latex containing 0%, 5%, 10%, and 15% EC was 75.1%, 65.8%, 70.1% and 84.1%, respectively, after 42 days, and controlled-release urea encapsulated by EC/BA/VAc latex (5% EC) had the best controlled-release ability. Therefore, controlled-release urea encapsulated by EC/BA/VAc latex has many potential applications in agricultural industry.

2

Dynamic Garment Simulation based on Hybrid Bounding Volume Hierarchy

Zhu D., Li Z., Xia F., Xu Y.

Autex Research Journal

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2016

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Vol. 16, no. 4

241--249

EN

In order to solve the computing speed and efficiency problem of existing dynamic clothing simulation, this paper presents a dynamic garment simulation based on a hybrid bounding volume hierarchy. It firstly uses MCASG graph theory to do the primary segmentation for a given three-dimensional human body model. And then it applies K-means cluster to do the secondary segmentation to collect the human body’s upper arms, lower arms, upper legs, lower legs, trunk, hip and woman’s chest as the elementary units of dynamic clothing simulation. According to different shapes of these elementary units, it chooses the closest and most efficient hybrid bounding box to specify these units, such as cylinder bounding box and elliptic cylinder bounding box. During the process of constructing these bounding boxes, it uses the least squares method and slices of the human body to get the related parameters. This approach makes it possible to use the least amount of bounding boxes to create close collision detection regions for the appearance of the human body. A spring-mass model based on a triangular mesh of the clothing model is finally constructed for dynamic simulation. The simulation result shows the feasibility and superiority of the method described.

3

Measuring Thread Densities of Woven Fabric Using the Fourier Transform

Pan R., Gao W., Li Z., Gou J., Zhang J., Zhu D.

Fibres & Textiles in Eastern Europe

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2015

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Vol. 23, no. 1 (109)

35--40

EN

To replace time-consuming and lab-intensive of manual inspection, a Fourier transform is proposed to detect the thread densities of woven fabric in this paper. First, theories of the Fourier transform, yarn image reconstruction and the threshold method are introduced. Then the steps of fabric image acquisition, the Fourier transform of the fabric image, feature analysis in the frequency domain, image construction of fabric yarns, and threshold processing are analysed. Lastly, after locating and counting the yarns in the fabric segmentation results, thread densities of the woven fabric are calculated. The experimental results prove that the method proposed can detect the thread densities of woven fabric correctly and it can be used to replace the current manual analysis.

PL

W celu zastąpienia pracochłonnego i czasochłonnego ręcznego sprawdzania zaproponowano specjalny system dla oznaczania gęstości nitek w tkaninie. Przedstawiono teorię transformacji Fouriera, rekonstrukcję wyglądu przędzy wraz z metodą progową. Określono stopnie akwizycji obrazu tkaniny, zastosowanie transformacji Fouriera, analizę częstotliwościową właściwości, konstrukcję obrazu nitek tkaniny i zastosowanie metody progowej. Pod koniec, po lokalizacji i zliczeniu nitek obliczono gęstość nitek w tkaninie. Wyniki pomiarów potwierdzają, że zaproponowana metoda automatycznej detekcji nitek jest prawidłowa.

4

Yarn-Dyed Fabric Defect Detection Based On Autocorrelation Function And GLCM

Zhu D., Pan R., Gao W., Zhang J.

Autex Research Journal

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2015

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Vol. 15, no. 3

226--232

EN

In this study, a new detection algorithm for yarn-dyed fabric defect based on autocorrelation function and grey level co-occurrence matrix (GLCM) is put forward. First, autocorrelation function is used to determine the pattern period of yarn-dyed fabric and according to this, the size of detection window can be obtained. Second, GLCMs are calculated with the specified parameters to characterise the original image. Third, Euclidean distances of GLCMs between being detected images and template image, which is selected from the defect-free fabric, are computed and then the threshold value is given to realise the defect detection. Experimental results show that the algorithm proposed in this study can achieve accurate detection of common defects of yarn-dyed fabric, such as the wrong weft, weft crackiness, stretched warp, oil stain and holes.

5

Forest fire monitoring system structure and node design based on wireless sensor network

Zhu D., Cai D.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

64--66

EN

Wireless sensor network is a new research field of computer sciences. Introduced some applications of wireless sensor networks in environmental monitoring; proposed a three-tier forest fire monitoring system and defined the main function of each layer; designed a portable wireless sensor network node, the module had advantages of volume small, portable, low energy consumption, easy maintenance, it’s very suitable for the application in forest fire monitoring.

PL

Nowym polem badań w informatyce są bezprzewodowe sieci czujnikowe (WSN). Znalazły one szereg zastosowań w badaniach środowiska. W opracowaniu zaproponowano trój-poziomowy system monitoringu pożaru lasu oraz zdefiniowano główną funkcję każdej warstwy. Opracowano przenośną stację węzłową WSN. Posiada ona szereg zalet: małe wymiary i pobór mocy, łatwość transportu i konserwacji. Jest bardzo odpowiednia do wykorzystania w monitoringu pożaru lasu.

6

Optimal Power Assignment and Coordinated Control Strategy for a Small-Scale Residential DC Microgrid

Xue G., Zhang Y., Zhu D.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 12a

226-232

EN

This paper focuses on control and operation of a small-scale residential dc microgrid supplied by photovoltaic array (PVA), fuel cell (FC) and super-capacitor (SC). The control scheme aims to realize the optimal power allocation, protect FC from fuel starvation, and stabilize dc bus voltage. The dc microgrid can operate in both islanded and grid-connected mode. To make the system work properly during islanding operation, power control and energy management strategy are proposed. When system is grid-connected, power balance is achieved by controlling the threephase voltage source rectifier (VSR). The effectiveness of the proposed control method is verified through simulations.

PL

W artykule skupiono się na zagadnieniu sterowania mikro-siecią DC małej skali w zastosowaniu mieszkaniowym, zasilanej z systemu złożonego z paneli fotowoltaicznych (ang. photovoltaic array), ogniw paliwowych (ang. fuel cell) oraz super-kondensatora (ang. super-capacitor), z naciskiem na optymalizację rozpływu mocy, zapewnienie dopływu paliwa dla ogniw paliwowych i stabilizację napięcia DC. Przeprowadzono analizę symulacyjną algorytmu, gdzie rozważono przypadki pracy wyspowej i podłączenia do sieci energetycznej.

7

Winter methane emission from an alpine open fen on Tibetan Plateau

Zhu D., Chen H., Wu N., Wang Y., Luo P.

Polish Journal of Ecology

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2011

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Vol. 59, nr 1

87-94

EN

Methane (CH4) emission was measured from an open fen on the Zoige Plateau (3500 m a.s.l.) (the eastern edge of the QinghaiTibetan Plateau) during two winters of 2006 and 2007. Three dominant plant stands, including Carex muliensis Hand-Mazz. (CM), Eleocharis valleculosa Ohwif. setosa (Ohwi) Kitagawa.(EV) and Kobresia tibetica Maxim (KT) were chosen to be monitored. Winter CH4 emissions were roughly estimated to be 0.94 mg CH4 m[^-2] h[^-1]. High spatialtemporal variations of the emission were found in this fen (the sequence of CM> EV> KT; 0.63 and 1.24 mg CH4 m[^-2] h[^-1] for 2006 and 2007, respectively). Factors involved in the spatial-temporal variation were: 1) water table in summer determining the winter amount of "old" CH4 stored in peat; 2) ice layer determining the release of CH4; 3) plant growth determining both the quantity of CH4 stored in peat and available substrates for CH4 production in winter. However, due to the homogeneity of freezing in winters, predictive factors such as plant growth and water table in summer could contribute more to winter CH4 emission than in situ freezing conditions. Considering that plant growth and water table are also the key factors controlling the spatial-temporal variation of CH4 emission in summer, we therefore suggested that winter CH4 emission represents the "inertia" of summer CH4 emission.

8

Synthesis, Characterization and Crystal Structure of (Z)-1-[2-(Tri-o-tolylstannyl)vinyl]-1-cyclopentanol and Its o-Tolylhalostannyl Derivatives

Zhu D., Lu S., Mei Z., Gao W., Zhang Y., Mu Y., Wang Z.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 1

63-70

EN

(Z)-1-[2-(Tri-o-tolylstannyl)vinyl]-1-cyclopentanol (1) was synthesized by the additive reaction of 1-ethynylcyclopentanol with tri-o-tolyltin hydride. One or two of the o-tolyl groups of compound 1 was substituted by I, Br or Cl to yield derivatives of the type CH2(CH2)3CH(OH)CH=CHSn(o-tol)3-nXn [n = 1, X = I (2), Br (3), Cl (4); n = 2, X = Br (5)]. The compounds 1-5 were characterized by elemental analysis, 1H NMR and FT-IR spectroscopy. The crystal and molecular structures of 1 and 2 have been determined by single crystal X-ray diffraction analysis. The Sn atom in 1exhibits a tetrahedral geometry distorted towards trigonal bipyramid, due to a weak intramolecular interaction between Sn and hydroxyl O atoms [2.813(4) A], while the Sn atom in 2 adopts a trigonal bipyramidal geometry with a significant Sn(1) O(1) interaction [2.553(4) A].