ISSN ONLINE(2319-8753)PRINT(2347-6710)

Yakışıklı erkek tatil için bir beldeye gidiyor burada kendisine türk Porno güzel bir seksi kadın ayarlıyor Onunla beraber otel odasına gidiyorlar Otel odasına rokettube giren kadın ilk önce erkekle sohbet ederek işi yavaş halletmeye çalışıyor sex hikayeleri Kocası fabrikatör olan sarışın Rus hatun şehirden biraz uzak olan bir türk porno kasabaya son derece lüks bir villa yaptırıp yerleşiyor Kocasını işe gönderip mobil porno istediği erkeği eve atan Rus hatun son olarak fotoğraf çekimi yapmak üzere türk porno evine gelen genç adamı bahçede azdırıyor Güzel hatun zengin bir iş adamının porno indir dostu olmayı kabul ediyor Adamın kendisine aldığı yazlık evde sikiş kalmaya başlayan hatun bir süre sonra kendi erkek arkadaşlarını bir bir çağırarak onlarla porno izle yapıyor Son olarak çağırdığı arkadaşını kapıda üzerinde beyaz gömleğin açık sikiş düğmelerinden fışkıran dik memeleri ile karşılayıp içeri girer girmez sikiş dudaklarına yapışarak sevişiyor Evin her köşesine yayılan inleme seslerinin eşliğinde yorgun düşerek orgazm oluyor

PREDICTION OF SURFACE ROUGHNESS AND APPLICATION OF RESPONSE SURFACE METHODOLOGY TO DEVELOP A MATHEMATICAL MODEL

N. Biswas1, J. De2, R. S. Sen3, B. Oraon3, G. Majumdar3
  1. Student, Department of Mechanical Engineering, Jadavpur University, Kolkata 700032, India
  2. Assistant Professor, Seacom Engineering College, Howrah, India
  3. Professor, Department of Mechanical Engineering, Jadavpur University, Kolkata 700032, India
Related article at Pubmed, Scholar Google

Visit for more related articles at International Journal of Innovative Research in Science, Engineering and Technology

Abstract

Ni-Cu-P coating was deposited on 99.99% pure Copper substrate electrolessly. The central composite design of experiment has been considered as the statistical analysis tool. The variation in surface roughness is studied by varying three parameters Ni-ion concentration, Cu-ion concentration and reducing agent concentration of the chemical bath. The surface roughness is considered as the response in student‟s t test and it has been observed that the Ni –ion source and Cu-ion source significantly influence the surface roughness at 10% level of significance. Also all the main effects (Ni-ion source, Cu-ion source, reducing ion source) and the interaction of Ni-ion and reducing agent, significantly influence the surface roughness at 20% level of significance. A mathematical model has developed considering second order response surface methodology which further considers the main effects as well as the effects of interaction and the effects of curvatures.

Keywords

Student‟s t test, Electroless Ni-Cu-P coating, RSM, CCD

INTRODUCTION

The term “Surface Roughness” refers to the deviation or undulation of a surface from a mean level on a given length of the surface. The surface roughness of electroless Ni-Cu-P coating is a very important property, as it determines the resistance to corrosion, predicts the wear phenomenon and determines the friction properties which helps to find the micro-hardness values of the coating-substrate combinations. The electroless bath typically consists of an aqueous solution of metal ions, reducing agents, complexing agents and stabilizers operating in a special ion concentration, temperature and pH ranges [12]. The basic chemical reactions for the electroless plating are as follows [12]:
image
Though copper have good mechanical properties and high thermal conductivity but oxidation and wear is a major problem in copper which can be solved by Ni-Cu-P coating without changing the bulk property of the substrate.

II. EXPERIMENTAL DETAILS

In this present work electroless Ni-Cu-P coating has been deposited on 20 × 15 × 0.1 ����3 99.99% pure Copper samples by Electrolessly. The samples are cut from 99.99% pure Copper strips and first rinsed in distilled water for cleaning and then the samples are acid pickled in dilute HCL. Then again they are rinsed in distilled water. Then the samples are kept to dry. The electroless bath comprised of the following chemical as shown in table 1. The bath is alkaline.
image
After the deposition of coating for 30 mins the samples are rinsed in distilled water and then properly dried. Then The surface roughness measurements are done by TalySurf machine by Taylor Hobson Precision Instrument Surtronic 3+. Both Horizontal Magnification (around 100) and Vertical Magnification (around 10000) are done by the instrument accordingly. The surface roughness measurements are taken over a standard sample-length of 25 mm.
image
image
image

III. STATISTICAL ANALYSIS

The Central Composite Design (CCD) is used for modelling a second-order response surface, A CCD consists of lk factorial or fractional factorial points, nf (usually coded ±1 rotation), 2k axial points [(±a,0,0, . . ., 0), (0,±a, 0, . . ., 0), (0, 0,±a, . . ., 0), . . ., (0, 0, . . .,±a)] and nc central points [(0, 0, 0,. . ., 0)] and central points, nc (to make CCD orthogonal or uniform precision design). The uniform precision design means that the variance of the response at origin is equal to the variance of the response at a unit distance from the origin. A uniform precision design ensures more protection against bias in the coefficients than an orthogonal design. A CCD can be made rotatable by selecting the appropriate value of α and for a rotatable CCD, α =± nf 4 . Therefore,
image
image\

IV. MATHEMATICAL MODEL FOR SECOND ORDER RESPONSE SURFACE

Response Surface Methodology (RSM) consists of statistical and mathematical techniques which are useful for developing, improving, and optimizing processes. The most extensive applications of RSM can be found in situations when several input variables potentially influence some performance measure or quality characteristic of a process. Thus performance measure or quality characteristic is called the response. This input variables are independent variables. Response Surface method develops a model that describes a continuous surface which connects the measured data taken at strategically important places in the experimental window. It also models the effects of parameters at different levels. RSM uses a least square curve-fit to develop a mathematical model tests its validity and analyze the developed model. RSM has the ability to predict, with statistical limits, the behaviour of the process at any point within the design window. The independent variables (denoted by X1, X2…Xk) are assumed to be continuous and can be controlled with negligible error. The response is postulated to be a random variable. The response is postulated to be a random variable. For three independent variables X1, X2 and X3, the response Ra can be represented as a function of X1, X2 and X3 as follows [14]:
image
E = a mathematical expectation The co-efficients of the fitted equations are obtained through the Response Surface Analysis in MINITAB Release 13.1 statistical software. The Second Order Response Surface Equation for Surface Roughness (Ra μm) is as follows: Ra = 0.51985 + 0.04932X1 + 0.02736X2 + 0.04925X3 + 0.01101X1X1 − 0.00490X2X2 − 0.00695X3X3 + 0.01040X1X2 + 0.02840X1X3 − 0.00055X2X3
image
image
image
image'

V. CONCLUSION

The surface roughness is considered as the response in student‟s test and it can be concluded that the Ni –ion source and Cu-ion source significantly influence the surface roughness at 10% level of significance. Also all the main effects (Ni-ion source, Cu-ion source, reducing ion source) and the interaction of Ni-ion and reducing agent, significantly influence the surface roughness at 20% level of significance. Fig 3-5 shows the surface plots and contour plots for�� a = f(X1, X2), �� a = f(X2, X3), and �� a = f(X1, X3). From fig 3 it can be observed that, keeping X3=0, for constant values of Copper source concentration (X2), the Surface Roughness of the samples increases with the increase in Nickel source concentration (X1).For constant values of X1, the Surface Roughness of the samples increases with the increase in copper concentration (X1) From fig 4 it can be observed that, keeping X1=0, for constant values of Copper source (X3), the Surface Roughness of the samples increases with the increase in copper concentration (X1) and then again decreases moderately. And for constant values of X2, the Surface Roughness increases upto a certain value of Copper source concentration (X2) and then again decreases moderately. From Fig 5 it can be observed that keeping X2 = 0, for constant values of reducing agent concentration (X3), the Surface Roughness decreases moderately and then again increases moderately upto a certain value of Nickel source concentration (X1). And for constant values of X1, the Surface Roughness increases moderately upto a certain value of reducing agent concentration (X3) and then again increases.

ACKNOWLEDGMENT

The authors gratefully wish to express deep gratitude to Metrology lab, Jadavpur University, India, for providing facility to carry out the experiment.

References

[1] N. Parvini-Ahmadi, M. A. Khosravipour, “Electroless Deposition of Ni-Cu-P Alloy on 304 Stainless Steel by Using Thiourea and Gelatin as Additives and Investigation of Some Properties of Deposits", International Journal of ISSI, Vol.1, No. 1, pp. 29-34, 2004.

[2] Zhang Bangwei and Xie Haowen, “Effect of alloying elements on the amorphous formation and corrosion resistance of electroless Ni–P based alloys”, Materials Science and Engineering, A281, pp. 286–291, 2000.

[3] Y. Liu and Q. Zhao, “Study of electroless Ni–Cu–P coatings and their anti-corrosion properties”, Applied Surface Science, 228, pp. 57–62, 2004.

[4] Guichang Liu, Lijun Yang, Lida Wang, Suilin Wang, Liu Chongyang and Jing Wang, “Corrosion behavior of electroless deposited Ni–Cu–P coating in flue gas condensate”, Surface & Coatings Technology, 204, pp. 3382–3386, 2010.

[5] E. Valova, J. Georgieva, S. Armyanov, I. Avramova , J. Dille, O. Kubova and M.-P. Delplancke-Ogletree, “Corrosion behavior of hybrid coatings: Electroless Ni–Cu–P and sputtered TiN”, Surface & Coatings Technology, 204, pp. 2775–2781, 2010.

[6] Q. Zhao and Y. Liu, “Electroless Ni–Cu–P–PTFE composite coatings and their anticorrosion properties”, Surface & Coatings Technology, 200, pp. 2510– 2514, 2005.

[7] Hui-Sheng Yu, Shou-Fu Luo and Yong-Rui Wang, “A comparative study on the crystallization behavior of electroless Ni–P and Ni–Cu–P deposits”, Surface and Coatings Technology, 148, pp. 143–148, 2001.

[8] E. Valovaa, J. Dilleb, S. Armyanova, J. Georgievaa, D. Tatcheva, M. Marinova, J.-L. Delplanckeb, O. Steenhautc and A. Hubinc, “Interface between electroless amorphous Ni–Cu–P coatings and Al substrate”, Surface & Coatings Technology, 190, pp. 336– 344, 2005.

[9] Q. Zhao, Y. Liu and E.W. Abel, “Effect of Cu content in electroless Ni–Cu–P–PTFE composite coatings on their anti-corrosion properties”, Materials Chemistry and Physics, 87, pp. 332–335, 2004.

[10] Liu Zhu, Laima Luo, Juan Luo, Yucheng Wu and Jian Li, “Effect of electroless plating Ni–Cu–P layer on brazability of cemented carbide to steel”, Surface & Coatings Technology, 206, pp. 2521–2524, 2012.

[11] Jen-Che Hsu and Kwang-Lung Lin, “The effect of saccharin addition on the mechanical properties and fracture behavior of electroless Ni–Cu– P deposit on Al”, Thin Solid Films, 471, pp. 186– 193, 2005.

[12] Reidel W, Electroless Ni Plating, Finishing Publications Ltd.UK, 1991.

[13] B. Oraon , G. Majumdar, B. Ghosh, “Parametric optimization and prediction of electroless Ni–B deposition”, Materials & Design, 28, pp. 2138-2147.

[14] B. Oraon, G. Majumdar, B. Ghosh, “Application of response surface method for predicting electroless nickel plating” , Materials & Design, 2006, 27, pp. 1035-1045, 2007.

[15] B. S. Choudhury, R. S. Sen, B. Oraon and G. Majumdar, “Statistical study of nickel and phosphorus contents in electroless Ni–P coatings”, Surface Engineering, 2007.