A perspective on systems and controls engineering in the earth moving and construction industry

1998 ◽  
Author(s):  
J.D. Duffy
Keyword(s):  
Construction Industry ◽  
The Earth ◽  
Controls Engineering

Influence of Rice Husk Ash on Characteristics of Earth Cement Blocks

MRS Advances ◽  
2020 ◽  
Vol 5 (54-55) ◽  
pp. 2793-2805
Author(s):  
Vasanthan Seevaratnam ◽  
Dilukshan Uthayakumar ◽  
Navaratnarajah Sathiparan
Keyword(s):  
Tensile Strength ◽  
Construction Industry ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Partial Replacement ◽  
Allowable Limit ◽  
Flexural Tensile Strength ◽  
The Earth ◽  
Cement Block ◽  
Great Reactivity

AbstractThis paper presents an experimental study on the characteristics of earth cement blocks with Rice Husk Ash (RHA) as a partial replacement to cement. The replacement of RHA content is limited to 0%, 5%, 10%, 15% and 20% by mass of the total binder in the earth cement block. The experiments on earth cement blocks investigate the compressive strength and flexural tensile strength for mechanical properties and water absorption, sorption rate and erosion against water spray for its durability. Due to the high content of SiO2 in RHA with great reactivity, a significant increase in the compressive and flexural tensile strength of earth cement blocks was observed up to 10% RHA content. However, the durability of earth cement blocks becomes adverse with the increasing percentage of RHA replacement, but within the allowable limit. The experimental results indicate that to some extent, RHA based earth cement blocks have a significant potential for reduction in cement used in the construction industry.

scholarly journals A STAKEHOLDER PERSPECTIVE ON THE IMPLEMENTATION OF SUSTAINABLE CONSTRUCTION PRACTICES

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Nokulunga Xolile Mashwama ◽  
Didibhuku Thwala ◽  
Clinton Aigbavboa ◽  
Mansur Hamma-Adama
Keyword(s):  
Construction Industry ◽  
South African ◽  
Carbon Dioxide Emission ◽  
Sustainable Construction ◽  
Survey Questionnaire ◽  
System Construction ◽  
The Earth ◽  
Greenhouse Emissions ◽  
Stakeholder Perspective ◽  
Emission Of Greenhouse Gases

The South African construction industry accounts for 23% of the greenhouse emissions, while manufactured materials amount to 4% of carbon dioxide emission. The human emission of greenhouse gases is the reason why the earth is warming up and making climate change a serious problem. The study adopted a quantitative approach in order to investigate on a stakeholder’s perspective on level of implementation and awareness of Sustainable Construction Practices (SCPS). A structured survey questionnaire was used as a tool for data collection where the questionnaires were distributed to construction industry stakeholders. Out of the 75 distributed questionnaires, 60 were retrieved and all were valid and usable. The study revealed that sustainable construction practices is partially implemented and the responded are aware of Industrialization building system; construction ecology; life cycle costing; design for the environment; lean construction as the best construction practices that when fully adopted they would contribute greatly to the ecosystem we live in. This study contributes to a wider awareness of SCPs to the professional in the industry.

scholarly journals The Impact of COVID-19 on the GCC Construction Industry

2022 ◽  
Vol 13 (2) ◽  
pp. 1-17
Author(s):  
Tariq Umar
Keyword(s):  
Construction Industry ◽  
Health And Safety ◽  
Legal Issues ◽  
Workforce Management ◽  
Face To Face ◽  
Global Recession ◽  
The Earth ◽  
Construction Organizations ◽  
The Impact ◽  
Industry Professionals

The Coronavirus pandemic has badly affected everyone on the earth. Apart from losing thousands of lives, businesses and individuals are going to be affected by the long-lasting financial effects due to an expected global recession. The impact of the financial crises can, however, be reduced if proper measured are put in place. This article aims to investigate the impact of Coronavirus on the construction industry in the Gulf Cooperation Council (GCC) member countries and provide recommendations to help the industry to sustain during this period of crisis. A qualitative research method involving face-to-face online interviews held with the construction industry professionals was adopted to achieve the aims and objectives of the research. Four main aspects of the impact on the construction industry are derived from analysis of interviews: 1) delays, 2) workforce management, 3) health and safety, and 4) legal issues. Recommendations are provided so that construction organizations in the GCC region can reduce the impact of Coronavirus on its businesses.

scholarly journals Assessment Risk in Construction Projects in Iraq Using COPRAS-SWARA Combined Method

2019 ◽  
Vol 54 (4) ◽  
Author(s):  
Ahmed Zghair Jaber
Keyword(s):  
Risk Assessment ◽  
Risk Management ◽  
Construction Industry ◽  
Preliminary Data ◽  
Construction Projects ◽  
Combined Method ◽  
Project Risk ◽  
The Earth ◽  
Copras Method ◽  
Constant Element

Risk in the age of globalization has become part of everyday life. Risk exists everywhere, in every area of life. One of these is the construction industry, where risk is a constant element in a big puzzle. This is true for construction projects in Iraq too, where official statistics indicate that most construction projects in Iraq always suffer from delay during the completion period and a significant increase in cost. Therefore, it is necessary to find a way to deal with this certain mater, meaning risk management. Risk management does not mean that the project is without risk, but means that dealing with the risk in different measures to ensure the success of the construction project. Risk management consists of several stages, the most important of which is the identification and assessment of the risks of the project. The objective of this paper is to identify and assess the risks in construction projects in Iraq by combining SWARA and COPRAS methods. To achieve the objective of the study, ten criteria for risk assessment were identified. Later the weights of criteria was determined using the SWARA method. The next step was identification and ranking of risks by using the COPRAS method. The result showed that mismatched plans with documentation, inaccurate surveys and preliminary data of the project, unqualified contractors, unexpected nature of the earth, and delayed implementation due to the contractor's capital deficiency were most important risk in construction projects in Iraq. Therefore, in order to tackle risks in Iraqi projects, there must be consideration of these risks, so as to achieve the goals of the project.

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

The Origin of the Moon and its Relationship to the Origin of the Solar System

1962 ◽  
Vol 14 ◽  
pp. 133-148 ◽  
Author(s):  
Harold C. Urey
Keyword(s):  
Solar System ◽  
The Moon ◽  
The Past ◽  
The Earth ◽  
Short Period ◽  
Origin Of The Moon

During the last 10 years, the writer has presented evidence indicating that the Moon was captured by the Earth and that the large collisions with its surface occurred within a surprisingly short period of time. These observations have been a continuous preoccupation during the past years and some explanation that seemed physically possible and reasonably probable has been sought.

Probable Structure and Nature of the Formations on the Reverse Side of the Moon According to Photometric Measurements of Lunar Photographs

1962 ◽  
Vol 14 ◽  
pp. 39-44
Author(s):  
A. V. Markov
Keyword(s):  
The Moon ◽  
Probable Structure ◽  
The Earth ◽  
Interplanetary Station ◽  
Photometric Measurements ◽  
Automatic Interplanetary Station

Notwithstanding the fact that a number of defects and distortions, introduced in transmission of the images of the latter to the Earth, mar the negatives of the reverse side of the Moon, indirectly obtained on 7 October 1959 by the automatic interplanetary station (AIS), it was possible to use the photometric measurements of the secondary (terrestrial) positives of the reverse side of the Moon in the experiment of the first comparison of the characteristics of the surfaces of the visible and invisible hemispheres of the Moon.

Seti Space Missions

1997 ◽  
Vol 161 ◽  
pp. 761-776 ◽  
Author(s):  
Claudio Maccone
Keyword(s):  
Electromagnetic Waves ◽  
Space Missions ◽  
Gravitational Lens ◽  
The Sun ◽  
Space Antenna ◽  
Focal Distance ◽  
Large Space ◽  
The Earth ◽  
Space Antennas ◽  
New Space

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.

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