Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Box


Experimental Analysis of Several Variables Influencing Formed Thickness in Two-Point Incremental Forming Process

A.K. Ibrahim; W.K. Hamdan

Engineering and Technology Journal, 2017, Volume 35, Issue 7, Pages 749-755

In the current paper, an experimental analysis on Al-sheet (AA 1050) with thickness 0.9 mm to reveal the effect of relevant forming factors on the formed thickness in two-point incremental forming (TPIF) process has been conducted. The formed thickness of pyramid-like shapes was analyzed by studying seven variables: die geometry, tool diameter, tool path, stepover, tool shape, lubricant and slope angle. The proposed analysis utilizes Box-Behnken design of experiment (BBD), main effects plot (MEP) and analysis of variance (ANOVA) for sake of studying the influences of the seven forming factors on the resulted thickness. The results of these analyses have indicated that the most significant factor affecting the formed thickness is the die geometry followed by tool shape, lubricant and stepover respectively for both slope angles of the pyramid. In addition, it has been found that the other variables have also significant effects on the formed thickness at both slopes of the pyramids produced.

Improvement Majority Function in A5/1 stream cipher Algorithm

Hala Bahjat; Mohanad Ali

Engineering and Technology Journal, 2016, Volume 34, Issue 1, Pages 16-25

Security is an important issue, especially in today’s technologically advanced society. Global System for Mobile Communications (GSM) is a world-wide standard for digital wireless communication. GSM uses A5/1 stream cipher in order to provide privacy on air communication. This paper introduce new improvements to the A5/1 stream cipher in order overcome the weakness that appear in clocking mechanism that used in A5/1 stream cipher. New S-box generation is proposed to increase the efficient for A5/1 majority function and improve randomness features. The randomness results confirm that the output bit-stream generated by the proposed stream cipher has improved the randomness performance.

Proposal New S-box for AES Algorithm Depend on A.I Bee Colony

Alaa Kadhim; Sura Khalaf

Engineering and Technology Journal, 2015, Volume 33, Issue 1, Pages 12-24

The AES algorithm, also called the Rijndael algorithm, is a symmetric block cipher, where the data are encrypted/ decrypted in blocks of 128 bits. Each data block is modified by several rounds of processing, where each round involves four steps. Three different key sizes are allowed: 128 bits, 192 bits, or 256 bits, and the corresponding number of rounds for each is 10 rounds, 12 rounds, or 14 rounds, respectively. From the original key, a different “round key” is computed for each of these rounds. The single nonlinear step is the Sub Bytes step, where each byte of the input is replaced by the result of applying the “S-box” function to that byte. This nonlinear function involves finding the inverse of the 8-bit number, considered as an element of the Galois field GF (216). The Galois inverse is not a simple calculation, and so many current implementations use a table of the S-box function output. This table look-up method is fast and easy to implement. S-box is influenced by linear and differential cryptanalysis and also interpolation attacks. In this paper intended a new approach for the design of s-box based on the bee colony algorithm to increase the power of s-box and enhanced resistance against attacks through the use of artificial intelligence algorithms.

Optimum Effect of Factors Influencing on Sacrificial Cathodic Protection for Steel Wall

Mohammad H. Hafiz; Wissam K. Hamdan; Saad E. Kaskah

Engineering and Technology Journal, 2012, Volume 30, Issue 18, Pages 3154-3163

The Box-Behnken Design (BBD) is used to model the sacrificial Cathodic
Protection System (SCPS) to find the factors effectiveness behaviour. For protection
potential assessment the BBD receives (resistivity of environment, sacrificial anode
alloy, distance between anode and cathode and surface area for the structure to be
protected) as input and gives the protection potential as output. By applying BBD
with their analysis tools we get many results. The important results which are the
factors individual effectiveness on the sacrificial cathodic protection (SCP) process
are the resistivity which has the greatest effect on the potential protection (rank=1)
followed by sacrificial anode alloy type (rank=2), surface area for structure protected
required (rank=3) and distance between anode and cathode (rank=4). The interaction
of sacrificial anode alloy and cathode area (χ2χ4) has significant effect on CP process
with the limits which are used in this work while the other factors interaction (χ1χ2,
χ1χ3, χ1χ4,χ2χ3, χ3χ4) has insignificant effect on the limits which used in this work.

Electrochemical Behavior of Chemical Conversion of Coated Aluminum 1100Al in a Neutral Tartrate Solution

Khalid H. Rashid

Engineering and Technology Journal, 2010, Volume 28, Issue 18, Pages 5640-5650

1100 Al specimens were anodically oxidized in different concentrations of
tartaric acid-tartrate solution (pH=7) in 1, 1.75, 3.25 and 4 wt % at temperatures of
30, 37.5, 52.5 and 60 ºC by applying a range of potentials of 30, 37.5, 52.5 and 60
V at exposure times of 40, 47.5, 62.5 and 70 min.. These four variables are
manipulated through the experimental work using Box – Wilson experimental
design where second order polynomial model was proposed to correlate the studied
variables with the thickness of anodic film of aluminum alloy (1100) to estimate
the coefficients of the proposed polynomial adopted via statistica software.
Optimum conditions for achieving the maximum film thickness are obtained from
optimizing the above correlation and are found as follows: temp. = 44ºC, acid conc.
= 2.8 wt %, voltage = 43.6 V, time = 54.6 min.. Stagnate Solutions of 3, 5, 10 and
25 wt % Nacl at 25ºC have been investigated using polarization technique at
optimum conditions for anodizing. The most important feature achieved was the
great difference in behavior between the anodic polarization curves for bare and
anodized aluminum in different concentrations of Nacl solutions. The corrosion
rates for anodized specimens are lower than those for unanodized ones. The
polarization behavior of anodizing specimens shows that the breakdown potentials
are shifted to more noble direction than bare specimens which is more pronounced
in 25 wt % Nacl solution due to anodizing.

The Determination of Optimum Conditions for Anodizing Aluminum Alloy (6063)

Uday Sami Mohammad; Sami A.Ajeel

Engineering and Technology Journal, 2008, Volume 26, Issue 11, Pages 1341-1354

Aluminum alloy (6063) has been anodized using sulfuric acid as an
electrolyte. To study the characteristic of the anodic film, four variables, were
considered as the most dominant variables. These variables are: current density in the
range of 1- 4 A/dm2, electrolyte concentration in the range of 6 - 20 vol.%, electrolyte
temperature in the range of 10- 30oC and anodizing time between 12- 60 min.
These four variables are manipulated through the experimental work using Box –
Wilson experimental design where second order polynomial model was proposed to
correlate the studied variables with the thickness of anodic film of aluminum alloy
(6063) to estimate the coefficients of the proposed polynomial adopted via statistica
software.
The predicated models are found after statistically analyzing the significance as
follows:
Y= 27.7800 + 8.0737X1 - 0.8037X3 + 8.2078X4 - 0.6994X2
1 - 0.8882X2
2
- 1.5582X2
3 - 1.1231X1X2 + 2.6225X1X4 - 1.7931X2X3 - 1.6956X2X4
- 1.0581X3X4
where Y is the objective function (thickness of anodic film), X1 is the current density;
X2 is the electrolyte concentration; X3 is the temperature of electrolyte and X4 is the
anodizing time.
The study shows that the anodizing time and current density had shown positive
dependence of great significance on the anodic film thickness while the other two
studied variables (i.e. concentration and temperature of electrolyte) had shown small
dependence on the film thickness of aluminum alloy (6063).
Optimum conditions for achieving the maximum film thickness are obtained from
optimizing the above correlation and are found as follow: 4 A /dm2 Current
density, 6 vol. % Acid concentration, 19.5 oC Electrolyte temperature and 60 min.
time of anodizing.