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Articles 181 - 210 of 226

Full-Text Articles in Engineering

The Solvent Effectiveness On Extraction Process Of Seaweed Pigment, Warkoyo Warkoyo, Elfi Anis Saati Apr 2011

The Solvent Effectiveness On Extraction Process Of Seaweed Pigment, Warkoyo Warkoyo, Elfi Anis Saati

Makara Journal of Technology

Eucheuma cottonii seaweed is a species of seaweed cultured in Indonesian waters, because its cultivation is relatively easy and inexpensive. It has a wide variety of colors from green to yellow green, gray, red and brown, indicating photosynthetic pigments, such as chlorophyll and carotenoids. An important factor in the effectiveness of pigment extraction is the choice of solvent. The correct type of solvent in the extraction method of specific natural materials is important so that a pigment with optimum quality that is also benefical to the society can be produced. The target of this research is to obtain a high …


College Of Engineering Senior Design Competition Fall 2010, University Of Nevada, Las Vegas Dec 2010

College Of Engineering Senior Design Competition Fall 2010, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps to focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects …


Performance Of Nevada’S Aggregates In Alkali-Aggregate Reactivity Of Portland Cement Concrete, Mohammad Shahidul Islam May 2010

Performance Of Nevada’S Aggregates In Alkali-Aggregate Reactivity Of Portland Cement Concrete, Mohammad Shahidul Islam

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alkali-aggregate reaction (AAR) is a form of distress that occurs in concrete and results in serviceability problems, cracks, spalling, and other deterioration mechanisms. There are two categories of AAR, namely, alkali-silica reaction (ASR) and alkali-carbonate reaction (ACR). Alkali-silica reaction is one of the most recognized deleterious phenomena in concrete, and has been a major concern since its discovery in the 1940s. The reaction which occurs between reactive silica or silicates present in some aggregates and alkalis of Portland cement produces an alkali-silica gel that expands in the presence of moisture resulting in concrete cracks. ACR is also a chemical reaction …


Exploring Earth-Building Technology For Liberia., Isaac Dompo Mayon Aug 2009

Exploring Earth-Building Technology For Liberia., Isaac Dompo Mayon

Electronic Theses and Dissertations

This paper discusses earth as a building material and the extent to which earth building technology has evolved over the years. In particular it addresses the adobe, compressed and rammed earth techniques of earth building as suitable techniques for Liberia consumption. In addition, the paper investigates the suitability of the Latosols soils of Liberia for earth building construction purposes using standardized earth building principles and requirements. A local Johnson City, Tennessee, earth sample found to have the same physical characteristics of the Latosols of Liberia was used to simulate Liberia soils to produce specimen blocks at different configurations of moisture …


Finite Element Model Of A Tennis Racket, Sayali Shashikant Kapatkar Apr 2009

Finite Element Model Of A Tennis Racket, Sayali Shashikant Kapatkar

Mechanical & Aerospace Engineering Theses & Dissertations

An explicit finite-element (FE) model of a tennis racket and string was produced in NASTRAN/PATRAN. MSC/NASTRAN is a general-purpose FEA program capable of solving a wide variety of engineering problems such as linear static analysis, static analysis with geometric and material with nonlinearities, transient analysis with geometric and material nonlinearities. A finite element racket model was used to study the engineering characteristics that affect the "sweet spot" of a te1mis racket. A similar model was simulated by creating a tennis racket, a tennis ball and a string-bed, and it was validated against MADYMO (Mathematical Dynamic Model) data.

The MADYMO validation …


Optimal Utilization Of Timber Poles As Structural Members Of Formwork, Ladislaus Lwambuka Jun 2007

Optimal Utilization Of Timber Poles As Structural Members Of Formwork, Ladislaus Lwambuka

Tanzania Journal of Engineering and Technology (TJET)

Timber poles of the type “Mirunda” are commonly used in East Africa as formwork support structures for casting of reinforced concrete slabs, beams and canopies. It is also widely known that the “Mirunda” poles as structural members of formwork are massively used without any structural consideration and guidance. This common practice has resulted into wastage of natural resources and escalated construction costs. This study has attempted to establish the load bearing capacity of randomly selected “Mirunda” poles through laboratory testing. Using an existing construction site as a case study, the results have been used to establish the actual number of …


Humidification Factors From Laboratory Studies Of Fresh Smoke From Biomass Fuels, D. E. Day, J. L. Hand, C. M. Carrico, Guenter Engling, W. C. Malm Nov 2006

Humidification Factors From Laboratory Studies Of Fresh Smoke From Biomass Fuels, D. E. Day, J. L. Hand, C. M. Carrico, Guenter Engling, W. C. Malm

Materials Science and Engineering Faculty Research & Creative Works

Measurements of smoke aerosol humidification factors were performed in a laboratory for different biomass fuel types and burn conditions. Two nephelometers simultaneously measured dry and humidified light scattering coefficients (bsp(dry) and bsp(RH), respectively), providing the first observations of the temporal evolution of the humidification factor (f(RH) = bsp(RH)/bsp(dry)) for fresh (minutes-old) smoke. Hygroscopic characteristics of the smoke aerosols varied with fuel type and fire conditions, with the mean f(RH) ranging from 1.01 to 1.95 for fresh minutes-old smoke for the relative humidity (RH) range of 70-94%. These f(RH) values exhibited temporal variability, with some fuels alternating from hygroscopic to nonhygroscopic …


Processing And Optimization Of Natural Fiber Reinforced Composites Using Date Palm Fibers, Khalifa Musabbeh Suwaidan Hamad Al-Kaabi May 2004

Processing And Optimization Of Natural Fiber Reinforced Composites Using Date Palm Fibers, Khalifa Musabbeh Suwaidan Hamad Al-Kaabi

Theses

During the last twenty years, ecological concerns have resulted in a renewed interest in natural materials. Composite materials usually depend on using man-made fibers as the reinforcing element. The possibility of using natural fibers instead of synthetic fibers is gaining acceptance among users. This work aims to investigate the possibility of extracting natural fibers from date palm trees to be used as reinforcement with polymeric materials. The objective was achieved by characterizing fibers through different chemical, physical and mechanical tests and using different treatment methods in order to modify the fiber properties. Date Palm Fibers (DPF) exhibit a cylindrical shape …


Thermal Assessment Of Silicon-Based Composite Materials Used In Photovoltaics, Pavlos K. Bataglannis Jan 2003

Thermal Assessment Of Silicon-Based Composite Materials Used In Photovoltaics, Pavlos K. Bataglannis

Theses

Photovoltaics are devices that convert sunlight directly to electricity. It is well established that the conversion efficiency of mono and poly-crystalline silicon-based photovoltaic modules is inversely related to their temperature. Substantial improvements in operational performance can thus be achieved if the thermal energy accumulating in the material can be effectively dissipated.

Accurate modelling of modules would allow possible methods of thermal dissipation to be evaluated, and as a crucial component of the model, the thermal properties of the constituent materials of PV modules needed to be known. Special consideration needed to be given to the interfaces between dissimilar materials and …


Assessment Of The Recycled Concrete Aggregates Structural Suitability For Road Construction, Abdulla Yousef Ali Al-Ali Jun 2001

Assessment Of The Recycled Concrete Aggregates Structural Suitability For Road Construction, Abdulla Yousef Ali Al-Ali

Theses

In most aspects of modem life, there is a consensus among practitioners and decision makers of the importance of preserving the environment, and to find alternatives to the scarce natural materials. This can be accomplished by better utilization of the natural materials and/or recycling or reclaiming their waste, specially, if they are of finite resources. The recycled material could be an attractive alternative (both environmentally and economically) if its characteristics are proven to be close to those of the natural material.

Utilizing recycled mineral aggregates in the construction field in general and in highway pavement in specific is somehow governed …


Evaluation Of Unified Interaction Parameter Model Parameters For Calculating Activities Of Ferromanganese Alloys: Mn-Fe-C, Mn-Fe-Si, Mn-C-Si, And Mn-Fe-C-Si Systems, L. I. Hongjie, Arthur E. Morris Jan 1997

Evaluation Of Unified Interaction Parameter Model Parameters For Calculating Activities Of Ferromanganese Alloys: Mn-Fe-C, Mn-Fe-Si, Mn-C-Si, And Mn-Fe-C-Si Systems, L. I. Hongjie, Arthur E. Morris

Materials Science and Engineering Faculty Research & Creative Works

Interaction parameters for Mn-based alloys were evaluated using both carbon solubility and activity data for species in binary and ternary manganese alloys. The parameters at 1400 °C are the following εcc = -4.5; εccc = 58.8; εFeCC = 1.5; εFeCC = 2.5; In γC0 = -1.15 . εsisi = 15.5; εsisisi = 2.69; εFeSi = 2.5; εcsi = 12.4; εccsi = 27.5; In γSi0 = -7.46 The unified interaction parameter model (UIPM) was used to calculate the activity coefficients of species and the solubility of carbon in ferromanganese alloys (up to quaternary Mn-Fe-C-Si). The results were in good agreement with …


The Use Of Solid Waste Materials As Alternative Compositions In The Development Of Wood/Cement Blocks, Haig Mamas Vahradian Jan 1997

The Use Of Solid Waste Materials As Alternative Compositions In The Development Of Wood/Cement Blocks, Haig Mamas Vahradian

Dissertations and Theses @ UNI

As the population of the planet Earth increases, the need for affordable housing becomes a paramount issue in construction. This need is further complicated by the rising cost of basic building materials due to the depletion of natural resources throughout the world. These problems have caused the construction industry to refocus its attention on the elimination of waste through a comprehensive strategy to: (a) reclaim and recycle these resources into usable materials, and (b) develop products and markets in construction for recycled materials through research and testing to prove their integrity.

The purpose of this study is to determine the …


Long-Term Effects Of Neutron Absorber And Fuel Matrix Corrosion On Criticality, William Culbreth, P. Zielinski May 1994

Long-Term Effects Of Neutron Absorber And Fuel Matrix Corrosion On Criticality, William Culbreth, P. Zielinski

Mechanical Engineering Faculty Research

Proposed waste package designs will require the addition of neutron absorbing material to prevent the possibility of a sustained chain reaction occurring in the fuel in the event of water intrusion. Due to the low corrosion rates of the fuel matrix and the Zircaloy cladding, there is a possibility that the neutron absorbing material will corrode and leak from the waste container long before the subsequent release of fuel matrix material. An analysis of the release of fuel matrix and neutron absorber material based on a probabilistic model was conducted and the results were used to prepare input to KENO-V, …


Development Of An Automated Ultrasonic Inspection Cell For Detecting Subsurface Discontinuities In Cast Iron, John Scott Burningham Jan 1992

Development Of An Automated Ultrasonic Inspection Cell For Detecting Subsurface Discontinuities In Cast Iron, John Scott Burningham

Dissertations and Theses @ UNI

Manufacturing of value added products by companies in todays global marketplace requires the vendors to meet certain minimum standards, SAE, ASTM, ISO, etc. In a global economy, as a manufacturer for the year 2000 and beyond, preferred vendors will become ISO 9000 certified to maintain a market share of produced goods.

An automated inspection cell was developed for the inspection of cast iron ports to detect subsurface discontinuities. The cell consists of an ultrasonic flaw detector (UFD), transducer, robot, immersion tank, computer, and software. Normal beam pulse-echo ultrasonic nondestructive testing is performed on each rough casting.

Using test blocks and …


Using Living Materials To Intervene In The Natural Succession Process To Accelerate The Re-Development Of A Self-Sustaining Ecosystem That Has Been Damaged By Human Intervention, Eric Jorgensen Jan 1989

Using Living Materials To Intervene In The Natural Succession Process To Accelerate The Re-Development Of A Self-Sustaining Ecosystem That Has Been Damaged By Human Intervention, Eric Jorgensen

Materials Engineering

No abstract provided.


Wood Finishing For Tree Samples Of Five Honduran Species, Amilcar A. Cruz Apr 1979

Wood Finishing For Tree Samples Of Five Honduran Species, Amilcar A. Cruz

Graduate Research Papers

This research report will study the application of four wood finishing techniques to samples of each of five species of Honduran hardwood.

These four wood finishing methods are: The varnish-method, the lacquer method, the antiquing method and the oil-rub method. The researcher will attempt to determine which is the best method for each of the five species.


Non-Ferrous Metal Mining And Smelting In Australia, H. R. Hanley Jan 1963

Non-Ferrous Metal Mining And Smelting In Australia, H. R. Hanley

Missouri School of Mines and Metallurgy Bulletins

No abstract provided.


Autoclave Leaching Of Montana Chromite, Leonard S. Greely Feb 1960

Autoclave Leaching Of Montana Chromite, Leonard S. Greely

Bachelors Theses and Reports, 1928 - 1970

The purpose of this investigation was to determine the feasibility of caustic autoclaving of Montana chromite in order to recover the chromium in a relatively pure solution of sodium chromate.


Segregation Method As Possible Process To Beneficiate Oxidized Lead Ores, Jose Molfino Tomasio Jan 1960

Segregation Method As Possible Process To Beneficiate Oxidized Lead Ores, Jose Molfino Tomasio

Masters Theses

"In this investigation it has been demonstrated that the Segregation Process has merit for treating oxidized lead ores.

The process comprises heating the crushed ore with salt and coal at about 750° C. to produce metallic lead attached to the carbon particles, which then is recovered by conventional flotation methods.

The quantities of sodium chloride and coal required for the best segregation of lead obtained in this work was 1.0 percent of coal and 1.0 percent of salt by weight.

Good segregation was obtained by using salt and coal as fine as 65 or 48 mesh. Segregation varied with the …


An Investigation Of The Effectiveness Of Certain Organic Compounds In The Flotation Of Manganese Oxide Minerals, Johannes P. Dreyer May 1959

An Investigation Of The Effectiveness Of Certain Organic Compounds In The Flotation Of Manganese Oxide Minerals, Johannes P. Dreyer

Bachelors Theses and Reports, 1928 - 1970

This thesis has to do with the selective flotation of the manganese oxide minerals in an ore from Charco Redondo Mine, Oriente Province, Cuba. Since a sound knowledge of the nature of the emulsion-induced flotation process of these minerals does not exist, experimental research constitutes the most valuable resource for determining the extent to which different reagents influence the process. Moreover, a correlation of experimental results with the chemical and physical properties of the minerals and reagents can lead to the improvement of existing theories regarding the mechanism of a process.


Magma 1959, Associated Students Of The Montana State School Of Mines. Apr 1959

Magma 1959, Associated Students Of The Montana State School Of Mines.

Magma 1948-1997

Any year book has as its prime purpose the depiction of a school year in a manner that will recall the maximum of memories in future years. The Magma this year utilizes memories as a theme, but places a slight accent on those of the graduating seniors.


Some Properties Of Chrome-Magnesite Mixtures And Calcium Aluminate Cement-Magnesite Mixtures, Edward Charles Duderstadt Jan 1959

Some Properties Of Chrome-Magnesite Mixtures And Calcium Aluminate Cement-Magnesite Mixtures, Edward Charles Duderstadt

Masters Theses

"The knowledge of the physical and chemical properties of refractories is of great importance in determining their usefulness and application. The thermal expansion of refractories is of particular importance in that it affects the thermal stability of the product. A high coefficient of thermal expansion leads to greater spalling and destruction of the bricks in use. It is, therefore, desirable to develop compositions having low coefficients of thermal expansion. This investigation was undertaken (1) to determine some of the properties of chromite-magnesite refractory mixtures in an attempt to determine the optimum composition of these mixtures, the specific properties including thermal …


Methods To Improve The Metallurgy Of Bolivian Tin Ores, Oscar Davila-Michel Jan 1958

Methods To Improve The Metallurgy Of Bolivian Tin Ores, Oscar Davila-Michel

Masters Theses

"Tin is a rare element; among the base metals it is one of the rarest. Although it was one of the first metals used by man and has been used since prehistoric time, the ore-dressing and metallurgical methods of tin are inefficient and very wasteful.

The only tin deposits of importance in the Americas are located in Bolivia, South America, and it is in Bolivia that the problems of tin metallurgy are greatest. More than 50% of the tin that is mined in Bolivia is lost in the tailing dumps of the beneficiation plants. In a country where the export …


Investigation To Improve Recovery Of Copper And Gold From A Refractory Ore, Raymond Franklin Cathcart Jan 1951

Investigation To Improve Recovery Of Copper And Gold From A Refractory Ore, Raymond Franklin Cathcart

Masters Theses

"Results of tests presented in this paper indicate that the Santa Maria del Oro ores might be processed by a method which should yield a gold recovery of 96 to 98 percent and a copper recovery of about 78 percent, both figures subject to an increase with further work and study of the problem.

In the method of processing outlined in Figure IX, the ores, mixed as under present operating procedure, would be crushed to minus 20-mesh and roasted with ten pounds of sodium chloride per ton of feed in a multiple-hearth, down-draft roaster at temperatures varying to a maximum …


A Study Of Some Raw Materials For The Manufacture Of Silica Brick, Charles E. Shulze Jan 1951

A Study Of Some Raw Materials For The Manufacture Of Silica Brick, Charles E. Shulze

Masters Theses

"The ability of silica to carry a load to within a few degrees of its melting point and its tolerance for comparatively high concentrations of iron oxide and lime, have enabled it to maintain its position as the number one steelplant refractory. It is estimated that at least half of the volume of refractories used in the steel plant are silica bricks. Consequently the manufacture of silica refractories forms an industry of considerable importance.

Raw materials suitable for the manufacture of silica brick are widely distributed, but only a small number of deposits are used commercially for one reason or …


Montana Talc; Problems In Physical Properties, E. C. Armstrong Jun 1950

Montana Talc; Problems In Physical Properties, E. C. Armstrong

Bachelors Theses and Reports, 1928 - 1970

General information on talc, including foreign and United States occurrences, origin, and uses is covered. Montana deposits are discussed in greater detail as to location, geology, mineralogy, and mining. Studies of talc by petrographic and x-ray methods and an experiment to determine the porosity are described and discussed.


A Preliminary Study Of The Benefication Of Montana Corundum, John L. Brown May 1950

A Preliminary Study Of The Benefication Of Montana Corundum, John L. Brown

Bachelors Theses and Reports, 1928 - 1970

The objective of this thesis was to affect an effic­ient and economical recovery of corundum. The corundum oc­curs as a crude ore admixed with quartz and other diluents. Yet, this material is a potential Montana resource of a val­uable non-metallic mineral. In view of the strategic import­ance and the relatively small production of this mineral in the United States, it seems advisable at this time in world affairs to investigate every possible source of this mineral.


Caustic Leaching Of Montana Chromite, Chester Freshour May 1949

Caustic Leaching Of Montana Chromite, Chester Freshour

Bachelors Theses and Reports, 1928 - 1970

Chromite is the most important ore used for the production of chromium and chromium alloys. At present, the domestic production is insignificant as compared with the amount of chromite consumed in the United States.


Roasting And Leaching Of Montana Chromite, Jerry D. Murphy May 1948

Roasting And Leaching Of Montana Chromite, Jerry D. Murphy

Bachelors Theses and Reports, 1928 - 1970

The United States, although the leading consumer of chromite, depends almost entirely on imports for its supply. Domestic production of chromite is limited, because high-grade imported ore is plentiful and inexpensive in normal times. There are several large deposits of chromite in the United States, representing millions of tons of low grade ore. These deposits form a strategic reserve that must be used in time of national emergency.


Geology Of Montana, Stanley G. Olson May 1948

Geology Of Montana, Stanley G. Olson

Bachelors Theses and Reports, 1928 - 1970

A vast amount of information has been published by many workers on particular features of the geology of the state of Montana, as well as on local geology of many smaller divi­sions. However, a satisfactory summary of the geology in general, which would include all phases of geology as they apply to the greater area of the entire state, has not been published.