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An Assessment of Time Performance Metrics of Lift Systems in Selected Public High-Rise Buildings in Abuja, Nigeria
Emmanuel Chongcicimmi Ibrahim,
Olugbenga Ayeni,
Ibrahim Isah,
Buhari Mohammed Manzuma,
Andrew Mhya Stanley
Issue:
Volume 6, Issue 1, June 2022
Pages:
1-6
Received:
4 February 2022
Accepted:
21 February 2022
Published:
18 March 2022
DOI:
10.11648/j.ijaos.20220601.11
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Abstract: Lift systems in high-rise buildings are often confronted with problems associated with optimum service delivery. The optimum performance of these systems in public high-rise buildings enhances the efficiency of vertical transportation systems. Time performance parameters like the Average Waiting Time (AWT), Transit Time (TRT), and Time to Destination (TTD) are amongst the key performance indicators for examining the performance of lift systems in high-rise buildings. This study assessed the performance times of lift systems of selected high-rise buildings in Abuja city with the view to enhancing the efficiency of vertical transport systems in buildings. Field measurements on the AWT, TRT, and TTD were performed and a well-structured checklist was used for the collection of relevant data on 14 selected high-rise buildings and 41 lift systems in the Central Business District (CBD) of Abuja city. A digital stopwatch was used to measure the AWT and TRT while TTD was derived from the simple computation of AWT and TRT. All the measured parameters were evaluated against the standard performance requirements for an ideal lift system. Findings from the study show that 100% of the lifts installed in these buildings are traction lift types with 90% having an average rated speed of 1.0m/s. Results from the analysis showed that 85.7% of the buildings have lift systems with AWT above the minimum standard requirement. Significant differences (p<0.05) in the mean values of AWT, TRT, TTD were observed. Based on the findings, the assessed lift systems were considered to perform below the expected standard as the majority of buildings experienced long waiting times. This study has provided performance data for optimizing the service delivery of lift systems in high-rise buildings in Nigeria.
Abstract: Lift systems in high-rise buildings are often confronted with problems associated with optimum service delivery. The optimum performance of these systems in public high-rise buildings enhances the efficiency of vertical transportation systems. Time performance parameters like the Average Waiting Time (AWT), Transit Time (TRT), and Time to Destinati...
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Solution to the Problem of Gas Impurities Distribution in the Surface Layer of the Atmosphere with Stationary Modeling Methods Applied
Gennadiy Kotov,
Tatiana Sidorovich,
Sergey Fisenko
Issue:
Volume 6, Issue 1, June 2022
Pages:
7-12
Received:
7 December 2021
Accepted:
30 December 2021
Published:
9 April 2022
DOI:
10.11648/j.ijaos.20220601.12
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Abstract: The greatest threat of the hazardous chemical release is posed by a cloud of contaminated air that spreads under the influence of wind near the soil surface. There is a problem of predicting the contaminated zone parameters in order to ensure safety. Normally, various methods are used to calculate the concentration of a hazardous impurity for this purpose. However, the obtained results correlate poorly often with each other and with the available experimental data. The purpose of this work is to assess the applicability of theoretical methods for calculating the parameters of the contamination zone formed as a result of the hazardous substance evaporation from the liquid strait surface. Several methods are used in this work: field tests, calculations using Gaussian distribution, solving a two-dimensional equation of turbulent diffusion with wind speed varying in height, and a computational experiment using the ANSYS software package. Results. The article presents the data of field tests with the spill of liquid chlorine, showing the distribution of impurities with the wind flow in the horizontal and vertical directions. It presents calculation results of the concentration of impurities entering the atmosphere from the surface of a liquid strait under conditions close to field tests. The applicability of the methods used to calculate the parameters of the contaminated zone are assessed taking into account the data of field tests. The correlation between the experimental and calculated data have been established to be observed in the range of specific concentrations only. The spectrum of high concentrations is better described by solving the two-dimensional equation of turbulent diffusion. The spectrum of average concentration values – by Gaussian distribution and computational experiment using the ANSYS software package. Conclusion. Understanding the specifics of computational methods application allows to predict the distribution of impurities in the surface air layer more accurately, taking into account the intensity of the emission, wind speed and surface roughness.
Abstract: The greatest threat of the hazardous chemical release is posed by a cloud of contaminated air that spreads under the influence of wind near the soil surface. There is a problem of predicting the contaminated zone parameters in order to ensure safety. Normally, various methods are used to calculate the concentration of a hazardous impurity for this ...
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Temperature, Carbon Dioxide and Methane May Be Linked Through Sea Ice Dynamics
Clive Hambler,
Peter Alan Henderson
Issue:
Volume 6, Issue 1, June 2022
Pages:
13-34
Received:
26 May 2022
Accepted:
17 June 2022
Published:
27 June 2022
Abstract: Background: The seasonal cycle of atmospheric carbon dioxide is usually ascribed to the seasonality of Northern Hemisphere vegetation, and the seasonal cycle of methane is usually ascribed to seasonal removal by the hydroxyl radical. Objective: We test an alternative, that the cycles of these greenhouse gases might be linked to sea ice dynamics. Method: Time-series analysis of carbon dioxide, methane, sea ice parameters, vegetation greenness (NDVI), and temperature. We consider a variable that lags another can not be causal of the leading variable. Results: Carbon dioxide is very strongly correlated with sea ice dynamics, with the carbon dioxide rate at Mauna Loa lagging sea ice extent rate by 7 months. Methane is very strongly correlated with sea ice dynamics, with the global (and Mauna Loa) methane rate lagging sea ice extent rate by 5 months. Sea ice melt rate peaks in very tight synchrony with temperature in each Hemisphere. The very high synchrony of the two gases is most parsimoniously explained by a common causality acting in both Hemispheres. Conclusion: Time lags between variables indicate primary drivers of the gas dynamics are due to solar action on the polar regions, not mid-latitudes as is conventionally believed. Our results are consistent with a proposed role of a high-latitude temperature-dependent abiotic variable such as sea ice in the annual cycles of carbon dioxide and methane. If sea ice does not drive the net flux of these gases, it is a highly precise proxy for whatever does. Potential mechanisms should be investigated urgently.
Abstract: Background: The seasonal cycle of atmospheric carbon dioxide is usually ascribed to the seasonality of Northern Hemisphere vegetation, and the seasonal cycle of methane is usually ascribed to seasonal removal by the hydroxyl radical. Objective: We test an alternative, that the cycles of these greenhouse gases might be linked to sea ice dynamics. Me...
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