Full Text Available
Access Full Text at Repository
Access Full Text at Repository
Search Results - (code OR (made OR model)) shells
Search alternatives:
- Go to Previous Page
- Showing 181 - 183 results of 183
-
Mining for specialized metabolism genes in Red Sea brine pool prokaryotic metagenomes for antibacterial and anticancer activities by Ziko, Laila
Published 2019“…A subset of specialized metabolites (SMs) produced by microbes confer activities of pharmaceutical importance, such as antibacterial and anticancer effects, and are coded by specialized metabolism gene clusters (SMGCs) in the organisms’ genomes. …”
Get full text
Get full text
Thesis -
A feasibility study of the (3He,8He) reaction with the K600 magnetic spectrometer by Swartz, Jacobus Andreas
Published 2010Get full text
ThesisFull Text AvailableAccess Full Text at Repository -
Pyrolysis, ignition, and fire behaviour of agricultural food grains by Oguaka, Anene Basil Chukwuzubelu
Published 2023Get full text
ThesisFull Text AvailableAccess Full Text at Repository
Search Tools:
Refine Results
Page will reload when a filter is selected or excluded.- ASME 3 results 3
- FE Modeling 3 results 3
- Pressure drop 3 results 3
- "This research work investigated the modeling of Von Mises stress in LNG Spherical Carbon Steel Storage tank using assumed displacement Finite Element analysis based on shallow shell triangular elements. Using equations of elasticity, constant thickness carbon steel spherical storage tanks were subjected to different loading conditions. This paper stresses the need for proper definition of shallow element using sector angles to obtain the shallowness. The shallow spherical triangular element has five degrees of freedom at each of its corner node, which are the essential external degrees of freedom. The assumed displacement fields of these shallow triangular elements satisfied the exact requirement of rigid body modes of motion. The FORTRAN 90 programming language was used for the programme coding to solve finite element equations resulting from the model while Von Mises stresses distribution within the spherical storage tank shell subjected to different internal pressures were determined. The results showed that the use of non-shallow elements due to improper sector angles resulted in unreliable results while real shallow elements produced results that tallied with ASME Section VIII Div 1, Part UG values. " 2 results 2
- ASCE 2 results 2
- Clay Silo 2 results 2
- FEM 2 results 2
- General 2 results 2
- Grain Quality 2 results 2
- LNG 2 results 2
- Level of Fill 2 results 2
- Maize 2 results 2
- Modeling 2 results 2
- Postharvest losses 2 results 2
- Shell-and-tube heat exchanger 2 results 2
- Shell-and-tube heat exchangers 2 results 2
- Silos have a fixed volume at the time of construction; harvests however vary from season to season. Complaints about severe postharvest losses in grains in the humid tropics of southern Nigeria necessitated a study into the effect of fill volume on quality of stored maize. Three clay silos labelled S1 to S3 of the same dimension and capacity (3.5 metric tonnes) were used. The silo walls were painted externally with gloss paint to reduce water absorption and filled with shelled maize. The first silo (S1) was filled with 3 tonnes, the second silo (S2) with 2 tonnes and the third (S3) filled with a tonne of maize for 6 months. Data was collected on microclimatic conditions within the silo and grain quality with increasing time of storage. Temperature, relative humidity (RH) and equilibrium moisture content (EMC) were recorded three times daily for each silo, focusing on the air between the grains and the headspace above the grains. Temperature fluctuations within S1 were smaller as indicated by the statistical range of 2 oC compared to S2 and S3 at 7 and 8 oC respectively. S3 showed high values of RH toward the end of storage, ranging between 65% to 80% at the top level and 76% at the bottom. EMC at the airspace above the grains in S1 increased from 12.0% at the beginning of storage in the dry season to 15.6% at the end of storage in the rainy season compared with S2 and S3 which increased from 12.0 to 17% and 12.0 to 17.2% respectively. Grains were found to be more prone to deterioration with decreasing level of fill because and increase in microbial activity was observed with a decreasing level of fill. Recommendations were made to farmers and grain aggregators on proper actions to take during grain storage given the peculiarities of the humid tropics. 2 results 2
- Spherical Storage Tank 2 results 2
- Von Mises Stress 2 results 2
- Weighted heat transfer coefficient 2 results 2
- Weighted performance factor 2 results 2
- " Road tankers are the most used means of transporting petroleum product to end users due to its cost effectiveness and energy-efficiency. The cylindrical tank has been well designed for by ASME VIII divisions 1 and 2 using analytical equations. Petrol tankers are not circular but elliptical probably for stability during transportation. This paper has used the finite element method to investigate in-plane displacements and Von-Mises stresses in both circular and elliptical cylindrical tanks under full loading. An elliptical OANDO? tanker of 66.78 m3volume and shell thickness of0.2 mmand an equivalent volume circular cylindrical tank was used for the simulation. MATLAB? was used to generate geometrical mesh model of the petroleum tankers, extract element coordinates and conduct the finite element analysis. Plane strain condition was used in analyzing a section of the petroleum tanker. It was observed that an equivalent volume circular cylindrical tank was under a higher internal pressure (16,858 N/m2) compared to the elliptical cylinder (14,480 N/m2). Von-Mises stress and in-plane displacements showed direct linear relationships with internal fluid pressure. Von-Mises stress in the elliptical tank was found to be lower (5.7 × 106 N/m2) than for the circular tank (8 × 106 N/m2). In plane displacements was zero in the longitudinal direction for both tanks and of the order of 10-4 mm in the y-direction for both tanks with the circular larger by about 2.5 × 10-3 cm. So in addition to tank stability on the lorry, the Von-Mises stresses were lower as well for the elliptical tank. It was also observed that Von-Mises stresses were far below the yield stress of the steel plate. However, the effect of weldment area on lowering of yield stress was not studied. Stress values were validated using analytical method and found to be insignificantly different (P > 0.05). " 1 results 1
- "Combustion characteristics of coconut shell (CS) samples in an experimental model bubbling fluidized bed combustor (BFBC) was investigated with special focus on effect of particle size of the CS CS waste obtained from farm were crushed and classified into three sizes; Size X (12-50mm), SizeY (2-l2mm) and Size Z (<2mm). For overbed feeding of the feedstock, the impact of the particle size on emission and combustion performance were examined. in a 150mm diameter experimental model BFBC. Throughout the investigation inert bed temperature was fixed to a constant value of 750°C by means of electronic based inert bed temperature regulating unit (ITRU). Results showed that CS particle size have pronounced impact on combustion characteristics and the pollutants emission from the BFBC. It was observed that the Pollutants' emission was within acceptable limits for Size Y at about 310ppm for CO, <200PPM for NOx and almost zero for SOx. The results indicate that CS could be used as combustion feedstock for environmentally energy generation in a BFBC. " 1 results 1
- "Heat flow patterns in two salt bath furnaces were studied in this work using finite element(FE) analysis. The implications of the heat flows on long term stability of furnace performance were evaluated. One design had a purely silica brick back-up after the embedded heating element with asbestos and glass-wool fiber insulation just before the outer steel shell. The other had an additional air-gap insulation formed by cylindrical steel belts with spacers placed after the silica back-up. It was observed that the design with additional air-gap insulation had tremendous insulation effect, necessitating a drastic thinning down of the silica brick thickness and glass wool fiber. " 1 results 1
- "Low cost and minimum emission of green house gases are two of the key advantages of using agricultural wastes as fuel in a bubbling fluidized bed combustor; however this advantage could be neutralized if significant cost and energy is spent on processing prior to usage of the waste, therefore if processing stage could be. circumvented without compromising effectiveness and efficiency, a substantial operational cost saving could be achieved when using biomass as fuel in a commercial scale bubbling fluidized bed combustor (BFBC). This research focus on use of 'as received' Palm kernel shell (PKS) in an experimental model bubbling fluidized bed combustor (BFBC). PKS feedstock received from the farm were cornbusted in several experiments in a 150mm diameter experimental model BFBC. The effect of large particle size feedstock of the 'as received'(4-22mm) on thermal profile and emission characteristics during the combustion process were examined. Operational chalienges such as fuel feeding, start-up and de-fluidization is examined and compare to situation when pulverized biomass is used. An electronic based inert bed temperature regulating unit ensure that the bed temperature is maintained at the pre-set value of 750°C in all the experiments. It was noted that combustion and emission characteristics with 'as received' PKS compare favourably with that of pulverized, however it was discovered that for specific feed rate( fd) and fluidizing air velocity.) the frequency at which the inert bed temperature regulating unit cut-off is higher for the 'as received'. The results indicate that PKS sample obtainable from Nigeria farms could be fired directly to generate energy in bubbling fluidized bed combustor. " 1 results 1
- "This work investigated the distribution of Von Misses stress in LNG Spherical Carbon Steel Storage tanks. Using the Finite Element Method and equations of elasticity, constant thickness carbon steel spherical storage tanks of 40 in. dia. 70in. dia of 1 in. shell thickness were subjected to different loading conditions from 500 to 4000Psi in incremental of 500 Psi. Spherical triangular elements based on shallow shell formulation were used for the model. The element has five degrees of freedom at each corner node, which are the essential external degrees of freedom without the degree of freedom associated with the in-plane shell rotation. The displacement fields of the element satisfy the exact requirement of rigid body modes of motion. The FORTRAN 90 coding was developed to obtain maximum Von Misses stress distribution with the tank subjected to different internal pressure and wind loadings. The results were then compared with the yield stress of the material of the tank. Von Misses stress is used as yield criteria whether to change tank material or increase the shell material thickness if yield stress is higher than the Von-Misses Stress. Results showed Von Mises stresses for a 40 in dia. Spherical shell with 1 in shell thickness able to withstand internal pressure loading alone up to 3500 Psi after which the shell thickness will no longer be able to withstand the loading. The 70in. dia. Vessel could only withstand internal pressure loading up to 2000 Psi. Validation of Finite Element modeling was done using ASME Section VIII Div 1 standard. Modeled results were observed not to be significantly different from ASME values (P>0.05). External wind effects alone on small dia. vessels was seen to be constant for all sides of the pressure vessel. 1 results 1
- A solar-powered adsorption refrigerator using activated carbon/methanol pair was designed and fabricated. The refrigerator has three major components: collector-condenser, and evaporator. A 3 mm thick flat glass was used as flat plate collector. The condenser was made of spirally coiled copper tube immersed in pool of stagnant water contained in a reinforced sancrete tank. The .evaporator was fabricated from standard 15.6 mm diameter copper tubing. The activated carbon used as adsorbent was manufactured locally from shells of a palm kernel. The maximum temperature of 108°C attained in the solar collector was adequate for methanol generation, while maximum received insolation of 1000 kW/m2 was sufficient for methanol desorption. The solar coefficient of performance (COP) of the refrigerator ranged from 0.0339 to 0.0345 compared to 0.03 to 0.055 recorded in the literature. The study shows that a solar powered adsorption refrigerator will operate In Nigeria's tropical climate with satisfactory coefficient of performance. 1 results 1
- ANOVA 1 results 1
- Activated carbon, 1 results 1
- Adsorption, 1 results 1
- see all…
- SUNScholar — Stellenbosch University Repository 60 results 60
- UCTD — University of Cape Town Open Access Repository 57 results 57
- UPSpace — University of Pretoria Institutional Repository 24 results 24
- AUC Knowledge Fountain — bepress 8 results 8
- KNUSTSpace — Kwame Nkrumah University of Science & Technology (Ghana) 1 results 1