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Conversion of Carbon Dioxide from Air to Methanol, Formaldehyde, Formic Acid and Ammonium Pentaborate Tetrahydrate
Jesus Christus,
Michael Arden Madson
Issue:
Volume 4, Issue 2, June 2020
Pages:
13-16
Received:
22 July 2019
Accepted:
14 August 2019
Published:
28 May 2020
Abstract: A process for sequestering CO2 from air by sparging air through an NH4OH solution and adding NaBH4 produces formic acid, formaldehyde, methanol and ammonium pentaborate tetrahydrate in appreciable yields. This sparging chemistry centers around the well-known phenomenon of carbonate in strong bases. The newly discovered chemistry is based on H- as a nucleophile that can attack a nucleofuge, the carbonyl in carbonate in strong base. NaHCO3 was used as a positive control for the sparging method giving nearly identical IR spectra for sparged NH4OH and, NaHCO3 added NH4OH. This novel chemistry can be shown to produce H- substitution products of sulfate and phosphate esters of carbohydrates. The H- nucleophile adds one, two and three H atoms to carbonate, for formic acid, formaldehyde and methanol, respectively, two H atoms to sulfate esters and one H atom to phosphate. In this way phosphate versus sulfate substitution can be discerned by mass spectrometry using this chemistry. The pH profile of the reaction mixture for the NaHCO3 dissolved in 1 N NH4OH first dropped below starting pH possibly because the reaction vessel was capped, allowing NH3(g) to evolve and possibly drive the reaction forward. But then the pH returned to a slight lower pH than the starting pH 11.4. This novel chemistry may allow a sustainable reduction in the green-house gas, CO2, worldwide, to relieve pressure on food uses for corn and thereby avert food shortages throughout the world.
Abstract: A process for sequestering CO2 from air by sparging air through an NH4OH solution and adding NaBH4 produces formic acid, formaldehyde, methanol and ammonium pentaborate tetrahydrate in appreciable yields. This sparging chemistry centers around the well-known phenomenon of carbonate in strong bases. The newly discovered chemistry is based on H- as a...
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Assessment and Simulation of Gaseous Dispersion by Computational Fluid Dynamics (CFD): A Case Study of Shiraz Oil Refining Company
Shiva Hashemi,
Dariush Mowla,
Fereidoun Esmaeilzadeh
Issue:
Volume 4, Issue 2, June 2020
Pages:
17-23
Received:
13 January 2020
Accepted:
24 February 2020
Published:
29 May 2020
Abstract: Air pollution is simply defined as the presence of any substances such as solids, liquids and gases in the atmosphere, in the adequate amount and time that endangers the life of humans and other living creatures, or damages monuments or properties. In recent years, rapid development of industries including oil and gas industries has led to emit a considerable amount of various gaseous pollutants into the atmosphere. Therefore, developing a reliable model to predict distribution of gaseous pollutants in urban and industrial zones has become an interesting subject among environmental experts. In this study, the distribution of gaseous pollutants emitted from twenty-three stacks of different units located in Shiraz oil refining company is simulated based on the principles of Computational Fluid Dynamics (CFD). To obtain a pattern of pollutants dispersion around the Shiraz refinery, pollutants such as CO, HC, SO2 and NO are considered. To validate the proposed model, concentration of some pollutants is measured at several points of inside and outside of the refinery area and compared with the corresponding values predicted by the proposed model. Results show that there is a good agreement between the measured data and those obtained from the CFD simulation within 6.3% accuracy. Additionally, the concentrations of SO2 and HC in outside of refinery are sometimes more than their standard concentrations.
Abstract: Air pollution is simply defined as the presence of any substances such as solids, liquids and gases in the atmosphere, in the adequate amount and time that endangers the life of humans and other living creatures, or damages monuments or properties. In recent years, rapid development of industries including oil and gas industries has led to emit a c...
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Factors Affecting Labor Productivity in the Construction Industry
Rabia Almamlook,
Mohamed Bzizi,
Maha Al-Kbisbeh,
Tgarid Ali,
Ekbal Almajiri
Issue:
Volume 4, Issue 2, June 2020
Pages:
24-30
Received:
23 September 2019
Accepted:
19 November 2019
Published:
29 May 2020
Abstract: Labor productivity is gaining growing attention as the construction industry faces many challenges related to workforce, but one of the most important is poor labor productivity. Several construction projects were suffering from various problems, including poor management, declining fertility, and thus causing projects delay, and cost overruns. The main goals of this study, therefore, is to identify and rank the factors affecting labor productivity in the construction industry in Libya. To realize this objective, a statistically demonstrative sample of contractors and embassies were demanded to contribute to a structured questionnaire survey. The questionnaire contained 30 productivity factors that were secret under the following three primary categories: (1) Management, (2) Technological, (3) and Human/labor. The Management Group was ranked the first, followed by the Technological and Human/labors group. This study demonstrates that the following five factors, listed in descending order, are the most significant in their effects on construction labor productivity: (1) Lack of labor supervision; (2) Experience and skill of labor; (3) Construction technology; (4) Coordination among construction industry disciplines; (5) Errors in design drawings. The results obtained to fill a gap in knowledge of factors affecting labor productivity in Libya to develop a more in-depth perspective of the factors influencing the efficiency of operatives. This study also has provided some recommendations to be implemented by construction managers at the early stage of the construction project to achieve more effective management of construction labor forces.
Abstract: Labor productivity is gaining growing attention as the construction industry faces many challenges related to workforce, but one of the most important is poor labor productivity. Several construction projects were suffering from various problems, including poor management, declining fertility, and thus causing projects delay, and cost overruns. The...
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