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1

Accuracy of Potential Flow Methods to Solve Real-time Ship-Tug Interaction Effects within Ship Handling Simulators

Jayarathne B. N., Ranmuthugala D., Fei J.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2014

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Vol. 8 no. 4

497--504

EN

The hydrodynamic interaction effects between two vessels that are significantly different in size operating in close proximity can adversely affect the safety and handling of these vessels. Many ship handling simulator designers implement Potential Flow (PF) solvers to calculate real-time interaction effects. However, these PF solvers struggle to accurately predict the complicated flow regimes that can occur, for example as the flow passes a wet transom hull or one with a drift angle. When it comes to predicting the interaction effects on a tug during a ship assist, it is essential to consider the rapid changes of the tug’s drift angle, as the hull acts against the inflow creating a complicated flow regime. This paper investigates the ability of the commercial PF solver, Futureship®, to predict the accurate interaction effects acting on tugs operating at a drift angle during ship handling operations through a case study. This includes a comparison against Computation Fluid Dynamics (CFD) simulations and captive model tests to examine the suitability of the PF method for such duties. Although the PF solver can be tuned to solve streamline bodies, it needs further improvement to deal with hulls at drift angles.

2

EL and ITG Characterization of Large Areas Black Silicon Solar Cells VIA Screen Printing

Tang Y., Zhou C., Wang W., Zhou S., Zhao Y., Fei J., Cao H.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 3b

95--97

EN

A simple process of texturing silicon (Si) surfaces using gold (Au)-catalyzed wet chemical etching was used to form black Si (BS) on a (100) p-type substrate. The surface became uniformly black after 6 min, with a resulting reflectivity of < 2% over the 400 nm to 1100 nm wavelength range. Large areas (153.18 cm2) of black Si solar cells (BSSCs) with an n+-p-p+ structure were also fabricated using conventional processes, including POCl3 diffusion, screen printing, and co-firing. The resulting cells were divided into two groups according to the emitter (46 and 37 [omega]/􀀀), and their output parameters were studied. The best convention efficiency (Eff) was < 10%. The open-circuit voltage (Voc) was particularly low because of poor surface passivation, and the shunt resistance (Rsh) linearly decreased with the series resistance (Rs). Electroluminescence (EL) and infrared thermography (ITG) measurements were conducted to characterize the BSSCs. Both the emissivity and temperature were low and nonuniform. Optimizing the fabrication process by reducing the etching depth and lowering the dopant sheet resistance led to significant improvement in Voc (~48 mV) and Eff (~3.8% absolute). EL and ITG measurements indicate that Rs is another important factor that accounts for the poor properties of the BSSCs.

PL

W artykule opisano proces teksturowania powierzchni krzemowej w procesie wytrawiania chemicznego z katalizatorem w formie złota, na potrzeby produkcji czarnego krzemu (BS) na podłożu p. Zastosowane rozwiązanie m. in. optymalizacji procesu teksturowania, poprzez redukcję głębokości wytrawiania dało znaczącą poprawę napięcia Voc oraz Eff. Wykonane badania wskazują, że rezystancja szeregowa Rs stanowi ważny czynnik wpływający na działanie ogniw słonecznych, zbudowanych z czarnego krzemu.

3

EL and ITG Characterization of Large Areas Black Silicon Solar Cells VIA Screen Painting

Tang Y., Zhou C., Wang W., Zhou S., Zhao Y., Liu X., Zhao L., Li H., Chen J., Yan B., Fei J., Cao H., Wu X.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

151--154

EN

A simple process of texturing silicon (Si) surfaces using gold (Au)-catalyzed wet chemical etching was used to form black Si (BS) on a (100) p-type substrate. The surface became uniformly black after 6 min, with a resulting reflectivity of < 2% over the 400 nm to 1100 nm wavelength range. Large areas (153.18 cm 2) of black Si solar cells (BSSCs) with an n + -p-p + structure were also fabricated using conventional processes, including POCl3 diffusion, screen printing, and co-firing. The resulting cells were divided into two groups according to the emitter (46 and 37 Ω/), and their output parameters were studied. The best convention efficiency (Eff) was < 10%. The open-circuit voltage (Voc) was particularly low because of poor surface passivation, and the shunt resistance (Rsh) linearly decreased with the series resistance (Rs). Electroluminescence (EL) and infrared thermography (ITG) measurements were conducted to characterize the BSSCs. Both the emissivity and temperature were low and nonuniform. Optimizing the fabrication process by reducing the etching depth and lowering the dopant sheet resistance led to significant improvement in Voc (~48 mV) and Eff (~3.8% absolute). EL and ITG measurements indicate that Rs is another important factor that accounts for the poor properties of the BSSCs.

PL

Do wytworzenia czarnego krzemu (BS) na podłożu typu p-Si(100) zastosowano prosty sposób teksturowania powierzchni krzemowej metodą chemicznej akwaforty na mokro z zastosowaniem, jako katalizatora, nanocząstek złota (Au). Podłoże staje się jednolicie czarne po 6 min, osiągając współczynnik odbicia < 2% w zakresie długości fali od 400 nm do 1100 nm. Wykonano również dużą powierzchnię czarnych krzemowych ogniw słonecznych (BSSC), ze strukturą n + - p -n +, konwencjonalnymi metodami obejmującymi dyfuzję POC13,drukowanie maski i wyżarzanie. Otrzymane ogniwa dzielą się na dwie grupy w zależności od emitera (46 i 37Ω/): zbadano ich wyjściowe parametry. Najlepsza uzyskana wydajność wynosi < 10%. Napięcie obwodu otwartego (Voc) jest szczególnie niskie z powodu słabej pasywacji powierzchni, a rezystancja równoległa (Rsh) liniowo maleje z rezystancją szeregową (Rs). Charakterystykę BSSC określają pomiary elektroluminescencji (EL) i tomografii w podczerwieni (ITG).Zarówno emisyjność jak i temperatura są niskie i niejednorodne. Optymalizacja procesu wykonana przez zmniejszenie głębokości akwaforty i obniżenie rezystancji warstwy domieszkowania prowadzi do znaczącej poprawy Voc (ok. 48mV) i Eff (ok. 3,8%).

4

Application of carbon glacy electrode coated with multi-wall nanotube film for determination of bisphenol A in plastic waste samples

Lü S., Fei J., He Q., Hu S.

Chemia Analityczna

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2004

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Vol. 49, No. 5

607-617

EN

A sensitive electroanalytical procedure for determination of bisphenol A at a glassy carbon electrode (GCE) modified with a multi-wall carbon nanotube (MWCNT) film has been developed. MWCNT film modified GCE exhibited excellent electrochemical behavior towards the oxidation of bisphenol A. At the accumulating potential of 0.3 V, it was preconcentrated at the electrode surface. After 10 s quiescent time the potential was linearly scanned to the anodic direction from 0.3 V to 0.9 V. The oxidation peak was recorded at approximately 0.58 V. Experimental parameters, such as the amount of MWCNT on GCE surface, the pH of the supporting electrolyte, and the scan rate have been optimised, since they might have influenced oxidation current of bisphenol A. Under the optimum conditions the magnitude of the current response of bisphenol A changed linearly with its concentration from 5.0 × 10-8 to 2.0 × 10-5 mol L-1. A detection limit of 2.0 × 10-8 mol L-1 was found. The proposed procedure was applied to the determination of bisphenol A in various samples of plastic wastes.

PL

Opracowano czułą metodę elektroanalityczną do oznaczania bisfenolu A przy pomocy elektrody z węgla szklistego zmodyfikowanej błonkązwielościanowych węglowych nano-rurek. Elektroda ta wykazuje bardzo dobrą zdolność utleniania bisfenolu, który przy potencjale 0,3 V można zatężyć na jej powierzchni. Po zatężeniu bisfenolu A i zarejestrowaniu woltamperogramu w kierunku potencjałów dodatnich, pojawia się pik anodowy przy ok. 0,58 V. W pracy zoptymalizowano takie parametry jak: grubość błonki, pH roztworu i szybkość zmian potencjału. W warunkach optymalnych pik bisfenolu A zmienia się liniowo ze stężeniem w zakresie od 5.0 * 10(-8) do 2.0 x 1O(5) mol L(-1).Granicę wykrywalności określono na 2.0 x 10(-8) mol L(-1). Opracowaną metodę zastosowano do oznaczania bisfenolu A w odpadach plastikowych.