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Numerical Investigation: Unsteady Flow of an Incompressible Elastico-Viscous Fluid in a Tube of Spherical Cross Section on a Porous Boundary
Sanjay B. Kulkarni,
Hasim Chikte,
Murali Mohan
Issue:
Volume 1, Issue 4, December 2016
Pages:
66-73
Received:
25 October 2016
Accepted:
22 November 2016
Published:
4 January 2017
DOI:
10.11648/j.eas.20160104.11
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Abstract: Exact solution of an unsteady flow of elastico-viscous fluid through a porous media in a tube of spherical cross section under constant pressure gradient has been obtained in this paper. Initially, the flow is generated by a constant pressure gradient. After attaining the steady state, the pressure gradient is suddenly withdrawn and the resulting fluid motion in a tube of spherical cross section by taking into account of the porosity factor of the bounding surface is investigated. The problem is solved in two-stages: the first stage is a steady motion in tube under the influence of a constant pressure gradient, the second stage concern with an unsteady motion. The problem is solved employing separation of variables technique. The results are expressed in terms of a non-dimensional porosity parameter, elastico-viscosity parameter, which depends on the Non-Newtonian coefficient. The flow parameters are found to be identical with that of Newtonian case as elastic-viscosity parameter and porosity tends to infinity. Numerical results were simulated in MATLAB software to analyze the effect of Elastico-viscous parameter, porosity parameter on the velocity profile. Boundary conditions were satisfied. It is seen that the effect of elastico-viscosity parameter, porosity parameter of the bounding surface has significant effect on the velocity parameter.
Abstract: Exact solution of an unsteady flow of elastico-viscous fluid through a porous media in a tube of spherical cross section under constant pressure gradient has been obtained in this paper. Initially, the flow is generated by a constant pressure gradient. After attaining the steady state, the pressure gradient is suddenly withdrawn and the resulting f...
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Detailed Investigation of Index Properties and Rate of Consolidations of Nguzu Edda Lateritic Soils (South-Eastern Nigeria) Used for Road Construction
Nwadike Henry Onyebuchi,
Nweke Obisi Mathias
Issue:
Volume 1, Issue 4, December 2016
Pages:
74-86
Received:
24 July 2016
Accepted:
8 August 2016
Published:
13 January 2017
DOI:
10.11648/j.eas.20160104.12
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Abstract: This research project involves detailed investigation of index properties and rate of consolidations of Nguzu Edda lateritic soil used for road construction so as to give details of soil behaviour in solving engineering and environmental issues. Nguzu Edda lies within the Afikpo Syncline of the Southern Benue Trough, Nigeria. It is located within longitude 7°491 E to 7°541 E and latitude 5°451 N to 5°501 N covering an area extent of about 62km2. Seven (7) samples were collected for the geotechnical analysis. Some geotechnical parameters were used to assess the lateritic soils. All the analyses were carried out in accordance with the British Standard code of practice (BS1377:1990). The results indicated that the particle size gradation for gravel ranged from 58 to 89%, sand ranged from 2 to 10% and fines ranged from 9 to 35%; natural moisture content ranged from 4.95 to 12.03%; specific gravity ranged from 2.49 to 2.64; the bulk density ranged from 1662.1 to 1775.2 kg/m3, dry density from 1498.7 to 1689.2 kg/m3; the liquid limit ranged from 32 to 38%, plastic limit ranged from 21 to 25%, plasticity index ranged from 8 to 13%; linear shrinkage ranged from 10 to 16%; the maximum dry density ranged from 1.78 to 1.95 mg/m3, optimum moisture content ranged from 9.1 to 20%; the undrained triaxial test for cohesion (C) ranged from 130 to 146 kN/m2 and angle of internal friction (Ø) ranged from 15° to 20°; the values of free swell index ranged from 12 to 30.8%; the California bearing ratio values for unsoaked condition ranged from 51.29 to 87.50% while soaked California bearing ratio ranged from 33.48 to 62.50%. According to America Association of State Highway and Transport Officials (AASHTO) soil classification, all the samples can be classified as A-2 materials which consist of silty or clayey-gravel and sand and can be rated as excellent material for road construction. They satisfy Federal Ministry of Works and Housing requirements for subgrade and subbase materials. Samples S2, S6 and S7 may likely be suitable only for sub base course materials. The soil samples tested from the study area are adjudged suitable for sub grade, sub base and base course materials.
Abstract: This research project involves detailed investigation of index properties and rate of consolidations of Nguzu Edda lateritic soil used for road construction so as to give details of soil behaviour in solving engineering and environmental issues. Nguzu Edda lies within the Afikpo Syncline of the Southern Benue Trough, Nigeria. It is located within l...
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On the Performance of a Novel Bio-photovoltaic Hydrogen Cell from Green Leaves
Osayed S. M. Abu-Elyazeed,
Mohamed A. El-Sayed,
Youssef A. Attai,
Mohamed A. Nawar,
Hatem M. Sadek
Issue:
Volume 1, Issue 4, December 2016
Pages:
87-98
Received:
12 December 2016
Accepted:
30 December 2016
Published:
23 January 2017
DOI:
10.11648/j.eas.20160104.13
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Abstract: The main objective of this work was the design and construction of a bio-based novel photovoltaic. For this purpose, two prototypes were designed and constructed. The first was an efficient extraction prototype of active pigments, and then the validation of the pureness of the extracted pigments took place by using the Ultra Violet Visible region (UV-V) spectra and Infra-Red (IR) spectrum. And, the second prototype as novel bio-photovoltaic hydrogen cell (NB-PV) was consisting of three glass sections donor, acceptor and membrane. These sections were containing a certain water type dissolved active pigments extracted from spinach (Spinacia Oleracea) by using the first prototype. So, both water dissolved chlorophyll a (Chl a) and chlorophyll b (Chl b), and the water dissolved pheophytin (pheo) were contained in the donor and acceptor sections respectively. In addition, the third section enclosed a precipitated ferredoxin (Fd) on rice straw as membrane. The membrane design allowed only electron transportation from donor section to the acceptor section. This second prototype was used also for water dissociation (2H+ and O-) as byproducts of such novel cell. Hence, the performance of the novel cell was determined based on measuring the average output voltage and lifetime of such cell. The experimental program was designed to investigate different variables that affect the performance of the present cell such as operating pressure, water type and light intensity. The results showed that the average voltage output flux diminishes with any slight increase of the operating pressure above the atmospheric one. The maximum values of the output flux were achieved when the active pigments were dissolved in sea water (SW). The results also, indicated that the light intensity had a minimal effect on the average voltage output flux.
Abstract: The main objective of this work was the design and construction of a bio-based novel photovoltaic. For this purpose, two prototypes were designed and constructed. The first was an efficient extraction prototype of active pigments, and then the validation of the pureness of the extracted pigments took place by using the Ultra Violet Visible region (...
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Recent Results on Sliding Collapse for Masonry Structures Under Static Load Test
Fernando Magdalena,
Antonio Aznar,
Juan F. de la Torre,
José I. Hernando
Issue:
Volume 1, Issue 4, December 2016
Pages:
99-106
Received:
21 October 2016
Accepted:
8 November 2016
Published:
24 January 2017
DOI:
10.11648/j.eas.20160104.14
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Abstract: This paper presents experimental test on sliding collapse. An array of up to fifty three tests on dry masonry specimens has been performed. Each specimen is subjected only to self-weight and to a horizontal load, whose position is chosen from a predefined set of three different locations. For the rest of properties, all specimens are totally equal. For each of the three locations, two sub-arrays of ten specimens and one of thirty-three have been tested. For each specimen, pieces layout is randomly performed so that imperfections randomly spread throughout the specimen as well. The main aim of this work is the comparison of these static tests with the results obtained from several commonly used numerical methods, especially with the ones retrieved under the non-Standard Limit Analysis. This paper shows that when the contribution of mortar to the strength of the structure cannot be taken into account and collapse by sliding occurs, the solution for collapse load and mechanism can be multiple. Hence, and since the solution is not necessarily unique, we should carefully consider the limits under which all methods finding a unique solution can be used.
Abstract: This paper presents experimental test on sliding collapse. An array of up to fifty three tests on dry masonry specimens has been performed. Each specimen is subjected only to self-weight and to a horizontal load, whose position is chosen from a predefined set of three different locations. For the rest of properties, all specimens are totally equal....
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