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Full-Text Articles in Metallurgy

The Role Of Si3n4 Amorphous Phase In Nc-Tin/A-Si3n4 Nanocomposites In Increases The Hardness And Thermal Stability, Keba Moto Aug 2002

The Role Of Si3n4 Amorphous Phase In Nc-Tin/A-Si3n4 Nanocomposites In Increases The Hardness And Thermal Stability, Keba Moto

Makara Journal of Technology

The role of Si3N4 amorphous phase in nc-TiN/a-Si3N4 nanocomposites will be shown and compared with polycrystalline ZrN/Ni which has no such amorphous phase (non-composites). The presence of amorphous phase Si3N4 increases the hardness of film as well as the toughness of the bulk nanocomposites under indentation load. It has been observed that nc-TiN/a-Si3N4 nanocomposites films has higher thermal stability than ZrN/Ni polycrystalline films.


Biodiesel's Characteristics Preparation From Palm Oil, Tilani Hamid. S, Rachman Yusuf Aug 2002

Biodiesel's Characteristics Preparation From Palm Oil, Tilani Hamid. S, Rachman Yusuf

Makara Journal of Technology

Biodiesel’s characteristics preparation from palm oil. Using vegetable oils directly as an alternative diesel fuel has presented engine problems. The problems have been attributed to high viscosity of vegetable oil that causes the poor atomization of fuel in the injector system and pruduces uncomplete combustion. Therefore, it is necessary to convert the vegetable oil into ester (metil ester) by tranesterification process to decrease its viscosity. In this research has made biodiesel by reaction of palm oil and methanol using lye (NaOH) as catalyst with operation conditions: constant temperature at 60 oC in atmosferic pressure, palm oil : methanol volume ratio …


Development Of Hardness Measurement Procedure For Nanocomposite Nc-Tin/A-Si3n4, Keba Moto Aug 2002

Development Of Hardness Measurement Procedure For Nanocomposite Nc-Tin/A-Si3n4, Keba Moto

Makara Journal of Technology

Hardness of nc-TiN/a-Si3N4 nanocomposites which was determined by using two methods of measurements i. e. depth sensing method and remaining plastic indentation area that were magnified by using SEM (Scanning Electron Microscope) lie in the good agreement. The hardness value is not influenced by the biaxial and residual compressive stress. The measurement of the biaxial stress on the substrate shows a very small value of biaxial stress as well as the constant hardness and crystallite size against annealing temperature. Therefore, the reported hardness value here is the intrinsic value that depend on its microstructure properties.


Integrating Passenger And Modulo As Learning Tools For Collaborative Engineering Education, Kalamullah Ramli, Frank Schwarz, Stefan Werner, A Halim Shamsuddin, Axel Hunger Apr 2002

Integrating Passenger And Modulo As Learning Tools For Collaborative Engineering Education, Kalamullah Ramli, Frank Schwarz, Stefan Werner, A Halim Shamsuddin, Axel Hunger

Makara Journal of Technology

The University of Indonesia (UI), Gerhard Mercator University (GMU), the Universiti Kebangsaan Malaysia (UKM) have agreed to cooperate as partners to develop a joint bachelor (3+1) and masters (1+1) degree, and collaborate in the research fi elds of multimedia- and internet-based learning and application level active networks. This paper describes the introduction of the Offshore Project and the extending of information technology applications to the partner institutions in this international cooperation which would very much enhance the operations of the new initiative in engineering education, which could provide students in far distance with more fl exible learning environment.


Study Effect Of Salt Washing Process On Content And Iodium Stability Of Salt, Nelson Saksono Apr 2002

Study Effect Of Salt Washing Process On Content And Iodium Stability Of Salt, Nelson Saksono

Makara Journal of Technology

Effect of Salt Washing Process on Content and Iodium Stability of Salt. Salt washing process should increase the salt quality. It should clean the salt from sludge or clay and also reduce the impurity compound such as Mg, Ca and the reductor content. The objective of these reseach is to assess the effect of washing process on the content og hygroscopic impurities compound (Ca and Mg), and reductor content of salt. The research also investigate the water absorbing, pH, KIO3 content as function of time to obtain effect of washing process on KIO3 stability in salt. The experiment result shows …


Object Classfification In Computer Vision With Discriminant Analysis, Amir Hamzahan Apr 2002

Object Classfification In Computer Vision With Discriminant Analysis, Amir Hamzahan

Makara Journal of Technology

A robotic sensor system is always supported by a computer system called ‘computer vision’. The important concept of computer vision is object classfifi cation. In this study two algorithms for object classifi cation in this system will be compared. Firstly, A simple method that do not need complex computation and that considered as an informal method is called binary tree decision structure. This method is based on modest caracteristic decriptors of an object such as vertical line, horizontal line or ellipse line. Unfortunately this method has weakness in recognize an image that contaminated by a noise. Secondly, a more formal …


Making Alloys (Ti1 - Xalx) N Using Plasma Cvd Technique From Alcl3 Powder, H2 And N2 Gas ,With Solvent Ticl4, Keba Moto Apr 2002

Making Alloys (Ti1 - Xalx) N Using Plasma Cvd Technique From Alcl3 Powder, H2 And N2 Gas ,With Solvent Ticl4, Keba Moto

Makara Journal of Technology

The substitution of Ti atoms by Al atoms in TiN lattice sites to form (Ti1-xAlx)N is clearly demonstrated by the coatings which were deposited on steel substrate and using plasma CVD technique. The presence of Al atoms in TiN lattice site is shown by means of XRD and EDX techniques: lattice parameters decreasing of TiN as the fraction of Al increases (XRD) and precipitation of hexagonal AlN phase (XRD) as the fraction of Al exceeding 0.8 (EDX). The hardness of these coating are just around 30 GPa, which is beyond the values reported in literatures.


Effects Of 0.25 % Mo (Molybdenum) Which Is Contained In The Ductile Cast Iron On Mechanical Properties Of Austempered Ductile Iron (Adi)., Nukman Nukman, Bustanul Arifin, Bambang Sugiarto Apr 2002

Effects Of 0.25 % Mo (Molybdenum) Which Is Contained In The Ductile Cast Iron On Mechanical Properties Of Austempered Ductile Iron (Adi)., Nukman Nukman, Bustanul Arifin, Bambang Sugiarto

Makara Journal of Technology

The aim of this research is to investigate the effects of 0.25 % Mo (Molybdenum) which is contained in the ductile cast iron on mechanical properties of Austempered Ductile Iron (ADI). The various temperatures and the holding times are used in the heat treatment processes. Using a given 0.25 % Mo in the ductile iron, ADI's alloyed developes a higher ultimate tensile stress value and decreases the elongation if we compare with the as cast (non alloy ductile iron). The higher impact energy value obtained at 9000 C austenization and 375o C austempering temperatures during 60 minutes holding times. The …


The Manufacturing Properties Of Galvanised Steel Sheet With Hexagonal And Tetragonal Network Of Circle Holes, Rahmat Saptono Apr 2002

The Manufacturing Properties Of Galvanised Steel Sheet With Hexagonal And Tetragonal Network Of Circle Holes, Rahmat Saptono

Makara Journal of Technology

Galvanized steel sheet of 0.8 mm in thickness was drilled with circle holes of 2.5 mm diameter and spacing arranged in tetragonal and hexagonal pattern. The manufacturing properties of specimen were studied through drawing and stretching simulative test. It was concluded from the results that, at high ratio of punch to hole diameter (40/2.5), the drawing properties (LDR) of both square and hexagonal perforated sheet were slightly lower than that of solid sheet, while hexagonal perforated showing LDR somewhat higher than the square one. The stretching properties (LDH) of sheet, however, were much lower than that of solid sheet while …


Develops The Software Of Dsp Processor For The Cdma Circuitry, Arman Djohan D. Apr 2002

Develops The Software Of Dsp Processor For The Cdma Circuitry, Arman Djohan D.

Makara Journal of Technology

This research develops the software of DSP Processor type TMS320C54X for the CDMA circuitry. This research apply two algorithms namely Mathematic Algorithm and table lookup Algorithm. From both algorithms, the research examine what algorithm have the fasted processing time and the smallest memory occupation. From the examination results the Mathematic Algorithm have 20.62 milliseconds processing time and the Table lookup algorithm have 14.08 milliseconds processing time. The Table lookup algorithm have the fastest processing time because the Matematic algorithm need the rounding process of the fi gure. Eventhough such processing time is not exceed from the 125 millisecond of delay …


Effects Of Oxygen Content Of Admitted Gases In Sulfide Flotation, Brian J. Boyle May 1964

Effects Of Oxygen Content Of Admitted Gases In Sulfide Flotation, Brian J. Boyle

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.


Methods Of Studying The Effects Of Frothers, Frank L. Bazzanella May 1964

Methods Of Studying The Effects Of Frothers, Frank L. Bazzanella

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.


Studies In Modulation Of Interfacial Reactions For Certain Sulphide Minerals, Robert Owen Beyaert May 1963

Studies In Modulation Of Interfacial Reactions For Certain Sulphide Minerals, Robert Owen Beyaert

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.


Habit Modification Of Naclo3 With Nai, William A. Coghlan May 1963

Habit Modification Of Naclo3 With Nai, William A. Coghlan

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.


Production Of Standard-Grade Ferromanganese In An Electric Arc Furnace, Force F. Baney Jr. May 1963

Production Of Standard-Grade Ferromanganese In An Electric Arc Furnace, Force F. Baney Jr.

Bachelors Theses and Reports, 1928 - 1970

The investigations conducted in this project were essentially concerned with the effects of various compositions of two different slag systems upon the increased recovery of manganese in a standard-grade ferromanganese.


Investigation Of The Ternary System Silver-Aluminum-Indium (Ag-Al-In), Elvin H. Beardslee May 1963

Investigation Of The Ternary System Silver-Aluminum-Indium (Ag-Al-In), Elvin H. Beardslee

Bachelors Theses and Reports, 1928 - 1970

This thesis paper contains material pertaining to & preliminary investigation of the ternary system Ag-Al-In. Procedures in this preliminary investigation are discussed in detail.


Preliminary Examination Of The Aluminum Corner Of The Ternary System Aluminum-Silver-Indium (A1-Ag-In), Jerome J. Blake May 1963

Preliminary Examination Of The Aluminum Corner Of The Ternary System Aluminum-Silver-Indium (A1-Ag-In), Jerome J. Blake

Bachelors Theses and Reports, 1928 - 1970

In this paper the author attempts to lay the groundwork for future work on the Al-Ag-In system.


Increased Corrosion Of A 304 Stainless Steel Upon Bending, William C. Tiddy May 1963

Increased Corrosion Of A 304 Stainless Steel Upon Bending, William C. Tiddy

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.


Identification Of Nonmetallic Inclusions In Armco Ingot Iron With Polarized Light, Frank E. Panisko May 1963

Identification Of Nonmetallic Inclusions In Armco Ingot Iron With Polarized Light, Frank E. Panisko

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.


The Hydrometallurgy Of Uranium, John E. Cesarani Jan 1963

The Hydrometallurgy Of Uranium, John E. Cesarani

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.


Crystal Habit Modification Of Sodium Chlorate, Michael R. Keegan May 1962

Crystal Habit Modification Of Sodium Chlorate, Michael R. Keegan

Bachelors Theses and Reports, 1928 - 1970

All single crystals have a particular habit or morphology. The crystal habit refers to the relative degree of development of crystallographic planes into surfaces which make up the external appearance of the single crystal.

In this paper, NaClO3 is used as a parent crystal. Its simple cubic habit is modified to tetrahedral by the use of impurities of SO4=, S2O3=, Cr2O7=, and NO3-. The degree of habit change is studied as a function of impurity concentration and temperature. The problem and phenomena are explained in terms of surface chemistry and thermodynamics.


Physico-Chemical Principles Of Sixteenth Century Metallurgy, Robert E. Johnson May 1962

Physico-Chemical Principles Of Sixteenth Century Metallurgy, Robert E. Johnson

Bachelors Theses and Reports, 1928 - 1970

Following a review of sixteenth century metallurgical literature and a discussion of Gibbs free energy, this thesis discusses thermodynamic considerations of galena (PbS) reduction by iron from a lead assay of this period. The importance of fluxes in this assay is emphasized. The discussion covers both equilibrium and non-equilibrium conditions at 1100 degrees Celsius. Possible substitutes for iron are also covered.

Information from twenty-one small controlled lead assays is correlated with the thermodynamic discussion to determine the purpose of each constituent in the assay.


The Beneficiation Of Titaniferous-Magnetite Sands, Ronald Lloyd Nordwick May 1962

The Beneficiation Of Titaniferous-Magnetite Sands, Ronald Lloyd Nordwick

Bachelors Theses and Reports, 1928 - 1970

The purpose of this investigation of beneficiation methods is to develop and study possible economic methods for recovering an iron-titanium concentrate of sufficient purity to meet metallurgical requirements for subsequent direct reduction to pig iron and a high titanium slag.


Stress-Corrosion Cracking Of Brass, Paul A. Fossey May 1962

Stress-Corrosion Cracking Of Brass, Paul A. Fossey

Bachelors Theses and Reports, 1928 - 1970

the mechanism of stress-corrosion cracking of brass has been sought for many years. Investigators have proposed many mechanisms, but each of these mechanisms has always had several drawbacks. This paper presents an account of experimental work done in the laboratory on this subject and compares it to the work of previous investigations. It evaluates the mechanisms presented by investigators and shows the failures of these mechanisms. A theory of Nitrogen Embrittlement is presented and an evaluation of this theory with experimental work follows.


Experimental Arc Furnace Smelting Of Titaniferous Iron Sands From The Northern Oregon Coast, Allan P. Herring May 1962

Experimental Arc Furnace Smelting Of Titaniferous Iron Sands From The Northern Oregon Coast, Allan P. Herring

Bachelors Theses and Reports, 1928 - 1970

This investigation is an attempt to experimentally smelt titaniferous iron sands from the Northern Oregon Coast in a laboratory arc furnace.


The Effect Of Ph Upon Chelation Reactions In Montmorillonite Clays, Joseph Michael Keane May 1962

The Effect Of Ph Upon Chelation Reactions In Montmorillonite Clays, Joseph Michael Keane

Bachelors Theses and Reports, 1928 - 1970

The purpose of this thesis is to investigate several chelation reactions and determine the effect of variable pH upon these reactions.


An Investigation Of The Sintering Of Iron-Wire Compacts, George L. Vivian May 1962

An Investigation Of The Sintering Of Iron-Wire Compacts, George L. Vivian

Bachelors Theses and Reports, 1928 - 1970

A study of the sintering of iron has been made by observing the rate of bonding of iron wires wound on iron spools. The specimens were sintered at a constant temperature of 850c in vacuum furnaces capable of producing pressures of 10-5 to 10-4 mm of mercury, and the growth of the bond between wires was observed as a function of time.

It has been concluded that the volume-diffusion mechanism is strongly operating in the sintering of iron at 850c, but in an evacuated system, the evaporation-condensation mechanism also contributes to the sintering process.


The Identification Of Montana Clays By X-Ray Analysis, David Stephen Malyevac May 1959

The Identification Of Montana Clays By X-Ray Analysis, David Stephen Malyevac

Bachelors Theses and Reports, 1928 - 1970

The purpose of this study is to identify the various Montana clay minerals by means of X-ray diffraction. The ultimate aim of this investigation is to identify the different clay mixtures through an analysis of their respective diffraction patterns, and diffraction patterns obtained after various chemical and thermal treatments.


The Design And Construction Of An Electrolytic Cell For Aluminum Reduction, Thomas H. Melrose Jun 1954

The Design And Construction Of An Electrolytic Cell For Aluminum Reduction, Thomas H. Melrose

Bachelors Theses and Reports, 1928 - 1970

The purpose of this investigation was to design and construct a laboratory size electrolytic cell in which to reduce alumina, using the same basic materials that are used in a commercial size cell. The cell was designed to have a capacity of approxi­mately 100 grams of metallic aluminum produced every 8 hours. The cell was constructed so it could be operated continuously.


Investigation Of Inclusions In Armco Ingot Iron, Edwin J. Duncan Jun 1954

Investigation Of Inclusions In Armco Ingot Iron, Edwin J. Duncan

Bachelors Theses and Reports, 1928 - 1970

Various chemical and electrolytic separation methods were investigated in an attempt to separate the in­clusions in Armco ingot iron. Residues obtained were X-rayed for identification purposes. The microstruc­tures of this iron were studied with the object of de­termining the relative sizes, locations, and possible compositions of the inclusions.