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The Impact of Coal and Biomass Co-Firing on the Economy of Power Plant Carbon Capture
Get PDFA detailed economic evaluation was carried out to determine the impact of biomass and coal co-firing on power plant carbon capture by methods of plants equipment designing factors and performance, and the sum up of the associated breakdowns of CAPEX and OPEX. Based on the assumptions of the CO2 neutrality of biomass and likely governmental incentives to reduce CO2 emissions, the study results show that biomass and coal co-firing would result in both lower cost of carbon avoided (carbon capture) and lower incremental cost of electricity generation when MEA solvent carbon capture is applied. Two scenarios for co-firing with carbon capture, 30% biomass blending and 90% or 60% CO2 capture from stack, indicate different preference depending on lower or higher incentives
Examining Failure Behaviour of Commercially Pure Titanium During Tensile Deformation and Hole Expansion Test
Get PDFHole expansion ratio is a material parameter which defines the extent to which sheet metals are formed. Research has shown that, the stress state observed at the hole edge after hole expansion test is similar to those observed during conventional uniaxial tensile test. However, conventional tensile test methods are not efficient in evaluating material edge formability. This work utilised optical non-contact measuring techniques to examine failure behaviour during tensile test and hole expansion test of commercially pure titanium sheet, fabricated with either abrasive water jet cutting or electric discharge machining. The work found that, the deformation mode in conventional tensile testing are governed by localised necking and subsequently diffused necking prior to failure. Deformation mode observed in hole expansion test is characterised by localised necking with no visible occurrence of diffused necking prior to failure. The highest strains are concentrated at the hole edge during hole expansion test due to their sensitivity to the hole preparation method with accompanying multiple localised necking sites resulting in non-uniform deformation. Strains become concentrated in the bulk material microstructure rather than the machined edge during tensile testing resulting in single localised deformation site and a more homogenous deformation
A1- and A2-Milk and Their Effect on Human Health
Get PDFMilk proteins are a heterogeneous group of polymeric compounds that have a wide range of different molecular structures and properties. They occur as caseins, whey proteins, enzymes, minor proteins and nitrogen compounds. Caseins constitute about 80% of the total proteins of cow’s milk. β-casein is an important part of the caseins, which makes up about 37% of the total caseins. Within β-casein, there are a number of variants which are genetically determined. However, there are thirteen genetic variants of β-casein found in cow´s milk. A1 and A2 are the most common variants, which are called A1 β-casein (A1-milk) and A2 β-casein (A2-milk). The only difference between A1- and A2-milk is a difference in the 67th amino acid in the chain. At this position, A2-milk has a proline amino acid, while A1-milk has histidine amino acid. Several studies have reported that cow’s milk with a dominant or singular A2-milk may be healthier than A1-milk. These studies are based on digestion of A1-milk which lead to release β-casomorphin-7 (BCM-7). Subsequently increase inflammation, Type-1-diabetes, heart disease, autism, gastrointestinal discomfort and other disease in the consumer. For this reason, there is a growing global interest in A2-milk. In conclusion, the effects of A1-milk compared to A2-milk on human health show mixed results. On the basis of the available results, we cannot conclusively assess the health effects of A1-milk and A2-milk. Therefore, further investigations are needed
2D Analytical Model of Armature Reaction Magnetic Field Distribution in Slotless Permanent-Magnet Linear Tubular Machines
Get PDFThis paper presents a 2D analytical model for predicting the magnetic flux density distribution in slotless permanent-magnet (PM) linear tubular (PMLT) motors due to armature reaction effects based on the sub-domain method. According to this method, the machine cross-section is divided into the six sub-regions and Maxwell partial differential equations (PDEs) are formed in each sub-region. Solving these PDEs leads to defining the magnetic vector potential in each sub-region and applying curl on the calculated magnetic vector potential results in determining the magnetic flux density components. Eventually, the extracted results are compared with those of the finite-element method (FEM) to confirm the accuracy of the described analytical model. The results reveal that the presented analytical model is a suitable candidate for predicting the magnetic flux density components of the slotless PMLT motors in a shorter time
Studies on Beneficiation of Manganese Ore through High Intensity Magnetic Separator
Get PDFUpgradation techniques like wet sieving and magnetic separation were used to evaluate the beneficiation potential of manganese ore. During wet sieving, manganese content in raw ore was upgraded from 27% to a maximum value of 38% in the concentrate with a recovery of 30%. Size classification was found to have no measurable effect on manganese grade in magnetic separation. In the unsieved ground ore, manganese content of 45% was achieved with a recovery of 23% and Mn/Fe ratio of 19% at a magnetic intensity of 8500 Gauss. At the same operating conditions, SiO2 was reduced from 56% in the raw ore to 30% in the magnetic fraction. So, wet sieving technique leads to a comparatively lower manganese grade but better recovery. Conversely, a magnetic separation technique produced higher manganese grade but relatively lower recovery. Blending of the upgraded manganese ore with high grade iron ore can be done to achieve the required Mn/Fe ratio
Study on Negative Poisson Ratio and Energy Absorption Characteristics of Embedded Arrow Honeycomb Structure
Get PDF Impact collision exists widely in people's daily life and threatens people's life safety. Negative Poisson's ratio structure has good mechanical properties. Therefore, it is of great significance to design and study the energy absorption structure with negative Poisson's ratio effect. Based on the traditional symmetrical concave honeycomb structure (SCHS) with negative Poisson's ratio, two modified negative Poisson's ratio honeycomb structures are proposed by adding embedded straight rib arrow structure and embedded curved rib arrow structure, which are respectively called embedded straight rib arrow honeycomb structure (SRAH) and embedded curved rib arrow honeycomb structure (CRAH). Through finite element simulation experiment, the negative Poisson's ratio characteristics of two cellular cells were studied and the influence of structural parameters of the cells on the Poisson's ratio was discussed. ANSYS/LS-DYNA was used to analyze the energy absorption of the proposed three cellular structures at different impact velocities. Numerical simulation results show that the SRHS and CRAH have greater stress platform value, specific energy absorption and impact force efficiency than SCHS, indicating that the SRAH and CRAH exhibited better energy absorption efficiency and impact resistance performance
Numerical Simulation of Air Shock Wave Propagation Effects in Reinforced Concrete Columns
Get PDFReinforced concrete has been shown to be a desirable material of choice in blast resistant structures due to its availability, relatively low cost, and its inherent ability to absorb energy produced by explosions. Most research work investigating the behaviour of reinforced concrete columns to blast loading have concentrated on their response to planar loading from far-field explosions. Limited amount of work is available on the effects of near-field explosion on the behaviour of reinforced concrete columns. This study is aimed to investigate effects of explosive loads on RC column by using ALE method. Commercial finite element package, LS-DYNA is used to simulate the behavior of blast wave on RC columns. Numerical simulation is validated against experimental work done in literature. The experience gained from this research provides valuable information for the development of the finite element modeling of real blast load effects on RC columns
Prediction of Hole Expansion Ratio of Titanium Alloys Using R Programming
Get PDFThe hole expansion ratio (HER) is an important material property which defines the extent of edge formability of sheet metals. The stress states observed at the hole edge after the hole expansion test are similar to those seen during traditional uniaxial tensile deformation. This observation has provoked research, directed at ascertaining a correlation between the HER and tensile properties. In order to account for the forming behaviour of complex materials like titanium, a highly robust model that takes into account the material formability in all sheet-processing directions must be considered. The R programming language was used in this research to build a model fitting expression capable of predicting the HER as well as generating a regression model equation for titanium alloys, based on their thickness and Erichsen index number. The proposed regression model equation for predicting HER of titanium alloys exhibited an excellent statistical significance (p= 0.00076), indicating the robustness of the model fitting expression to predict HER values of titanium alloys. An accompanying adjusted R squared value of 0.9987 for the generated regression model equation also shows how well the regression line fits the data for accurate prediction of the HER of titanium alloys. A numerical validation analysis of the strength of the relationship derived between the predicted and the experimental HERs gave a correlation coefficient of 0.9884. This result shows a strong linear relationship between the experimental and predicted HER values of the titanium alloys with an average absolute error of 8.8%
Pre-processing Protocol for Nonlinear Regression of Uneven Spaced-Data
Get PDFRegression of experimental or simulated data has important implications in sensitivity studies, uncertainty analysis, and prediction accuracy. The fitness of a model is highly dependent on the number of data points and the locations of the chosen points on the curve. The objective of the research is to find the best scheme for a nonlinear regression model using a fraction of total data points without losing any features or trends in the data. Six different schemes are developed by setting criteria such as equal spacing along axes, equal distance between two consecutive points, constraint in the angle of curvature, etc. A workflow is provided to summarize the entire protocol of data preprocessing, training and testing nonlinear regression models with various schemes using a simulated temperature profile from an enhanced geothermal system. It is shown that only 5% of data points are sufficient to represent the entire curve using a regression model with a proper scheme
Verifying Moisture Damage Impact in Asphalt Concrete with the Aid of Nondestructive Test NDT
Get PDFOne of the major concerns of pavement durability is its susceptibility to moisture damage. In this investigation, non-destructive test NDT has been implemented to detect the moisture damage issue. Asphalt concrete specimens were prepared using the traditional Marshall method for wearing, binder and asphalt stabilized base course. Specimens were traversed by ultrasound pulse velocity before and after practicing the moisture damage procedure. The variation of dynamic and elastic modulus before and after the moisture damage was considered and related to tensile strength ratio TSR. It was noted that the pulse velocity decline by (11, 11.2 and 16.4) % and the dynamic modulus declines by (28, 6.6 and 28.5) % for asphalt concrete wearing, binder and base courses respectively after moisture damage. The elastic modulus exhibits no significant variation after moisture damage for wearing course while it declines by (9 and 11.7) % for binder and base courses respectively after moisture damage. It was concluded that the elastic and dynamic moduli were unable to clearly distinguish the impact of moisture damage, whereas the Seismic modulus calculated from the Ultrasonic Pulse Velocity test was effective in distinguishing such impact. The linear equation obtained with good coefficient of determination can explain 74 % of the variation in the seismic modulus after moisture damage