Designing Novel Nanostructured Permanent Magnets

Rare earth element based alloys have been the source of high performance magnetic alloys, and have played a paramount role in the development of various technologies, including: memory devices (such as credit cards, random-access memory), sensors, and various biomedical applications. However, there is a tremendous need to replace rare earth metals with material with powerful magnetic properties. Our group recently found CrTe-based materials that show very promising magnetic properties in nanostructured form. The magnetic modeling of such material in nanostructured form prior to their fabrication demonstrates their magnetic properties in bulk form. In this project, we investigate the behavior of bulk material made out of nanomagnets to predict the magnetic properties using Object Oriented Micromagnetic Framework, which will help screening candidate materials prior to their fabrication. We model a single spherical bulk nanomagnet and a touching bi-layer system with intergranular exchange. We then obtain coercivity as a function of anisotropy constant, and coercivity as a function of intergranular exchange. We show in the case of a single sphere, that coercivity increases when increasing anisotropy, and that small coercivity corresponds to small anisotropy and vortex switching. We further show that in bulk assembled material coercivity increases when increasing anisotropy as well as increasing intergranular exchange energy in the bi-layer system made of granular media

Some statistical methods for dimension reduction

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel UniversityThe aim of the work in this thesis is to carry out dimension reduction (DR) for high dimensional (HD) data by using statistical methods for variable selection, feature extraction and a combination of the two. In Chapter 2, the DR is carried out through robust feature extraction. Robust canonical correlation (RCCA) methods have been proposed. In the correlation matrix of canonical correlation analysis (CCA), we suggest that the Pearson correlation should be substituted by robust correlation measures in order to obtain robust correlation matrices. These matrices have been employed for producing RCCA. Moreover, the classical covariance matrix has been substituted by robust estimators for multivariate location and dispersion in order to get RCCA. In Chapter 3 and 4, the DR is carried out by combining the ideas of variable selection using regularisation methods with feature extraction, through the minimum average variance estimator (MAVE) and single index quantile regression (SIQ) methods, respectively. In particular, we extend the sparse MAVE (SMAVE) reported in (Wang and Yin, 2008) by combining the MAVE loss function with different regularisation penalties in Chapter 3. An extension of the SIQ of Wu et al. (2010) by considering different regularisation penalties is proposed in Chapter 4. In Chapter 5, the DR is done through variable selection under Bayesian framework. A flexible Bayesian framework for regularisation in quantile regression (QR) model has been proposed. This work is different from Bayesian Lasso quantile regression (BLQR), employing the asymmetric Laplace error distribution (ALD). The error distribution is assumed to be an infinite mixture of Gaussian (IMG) densities

Ultrafast and Efficient Scalable Image Compression Algorithm

Wavelet-based image compression algorithms have good performance and produce a rate scalable bitstream that can be decoded efficiently at several bit rates. Unfortunately, the discrete wavelet transform (DWT) has relatively high computational complexity. On the other hand, the discrete cosine transform (DCT) has low complexity and excellent compaction properties. Unfortunately, it is non-local, which necessitates implementing it as a block-based transform leading to the well-known blocking artifacts at the edges of the DCT blocks. This paper proposes a very fast and rate scalable algorithm that exploits the low complexity of DCT and the low complexity of the set partitioning technique used by the wavelet-based algorithms. Like JPEG, the proposed algorithm first transforms the image using block-based DCT. Then, it rearranges the DCT coefficients into a wavelet-like structure. Finally, the rearranged image is coded using a modified version of the SPECK algorithm, which is one of the best well-known wavelet-based algorithms. The modified SPECK consumes slightly less computer memory, has slightly lower complexity and slightly better performance than the original SPECK. The experimental results demonstrated that the proposed algorithm has competitive performance and high processing speed. Consequently, it has the best performance to complexity ratio among all the current rate scalable algorithms

Behavior of High Strength Hybrid Reinforcement Concrete Beams

Six proposed simply supported high strength-steel fiber reinforced concrete (HS-SFRC) beams reinforced with FRP (fiber reinforced polymer) rebars were numerically tested by finite element method using ABAQUS software to investigate their behavior under the flexural failure. The beams were divided into two groups depending on their cross sectional shape. Group A consisted of four trapezoidal beams with dimensions of (height 200 mm, top width 250 mm, and bottom width 125 mm), while group B consisted of two rectangular beams with dimensions of (125 ×200) mm. All specimens have same total length of 1500 mm, and they were also considered to be made of same high strength concrete designed material with 1% volume fraction of steel fiber. Different types and ratios of FRP rebar were used to reinforce these test beams. The study’s principle variables were the amount and type of flexural reinforcement (glass FRP and basalt FRP) and beam cross-sectional shape (rectangular and trapezoidal). The load-deflection behavior and ultimate load capacity of the beams were studied and compared with one another under flexural test with symmetrical two-point loading. The results show that increasing the reinforcement ratio resulted in higher post cracking flexural stiffness, and higher residual strength, as well as caused an increase in the first cracking load and ultimate load capacity ranged from 3 to 16.9%, and 4.6 to 7.3% respectively. When the GFRP rebars replaced by BFRP, the overall beams flexural performance showed outstanding improvements. Moreover the results indicate that increasing the top width of the beam cross section led to a significant enhancement in the first crack load ranged from 16 to 32.4%, also a remarkable increases in the ultimate load capacity in the range of 35.5 to 35.8% were indicated in the trapezoidal beams compared to rectangular beams. However the results show that the deflections were similar and were approximately 1.07–1.54 mm for all test beams. It is worth noting that the general flexural behavior of all the test beams indicated a ductile behavior with a gradual reduction in strength and high residual strength pre to failure due to proposing steel fiber presence

Enhancement of Pavement Condition and Its Impact on Pavement Sustainability: Environmental and Economic Assessments

The cost saving regarding vehicles operation, travel time and road maintenance has one eye-catching benefit via increasing pavement sustainability through maintaining the material sources and reducing the emissions of gases resulted from the processing of derivative products. Furthermore, the rate of increase of traffic on unpaved road is considered as a strong indicator to construct paved roads over this area.  In the present paper, the Nasiriya-Abu Ghar road was studied. It is one of the important unpaved roads. Its importance lies in the transport of construction materials from Abu Ghar quarries to the near provinces in Iraq, such as Dhi Qar Province. Abu Ghar quarries are considered as one of the most important quarries because it contains different construction materials such as gravel, limestone and sand. These materials have high engineering properties. Thus, the absence of a paved road linking Abu Ghar quarries with the surrounding areas, especially the province of Dhi Qar, encouraged to conduct a technical and economic feasibility study to highlight it and to help the decision-makers to implement the project. The present study contributes in statement of the economic and environmental feasibility of the construction of a new suggested road over the old unpaved one. The study depends on the hypothesis that the old road has a bad condition while the new one is an asphaltic concrete pavement with a good condition. The manual counting method of traffic volume was used from 7:00 am to 4:00 pm for 7 days to determine the peak hour volume and average daily traffic. Road's construction and maintenance costs were estimated. Saving in the road user costs for both existing (old) and new-suggested roads were calculated to be considered as benefits. The economic study is achieved by comparing the discounted total road costs and their benefits to the basic year (starting year of the project). In the present study, the adopted discount rate is 8%. To find the economic feasibility, some criteria were tested. These criteria are: Net Present Value (NPV), Benefit–Cost Ratio (B/C) and Internal Rate of Return (IRR). The results show that NPV has a positive value equals to 40,269,371 US$, which means that benefits are greater than costs. Furthermore, B/C ratio was 2.54; comparing with a value of 1.0, which is encouraging. Finally, the IRR was located between discount rates of 20% and 25 %, with a value of 22.9% which is higher than 8% "the recommended in the road projects". Keywords: Pavement Condition, Road User Costs, Economic Feasibility, Benefit –Cost Ratio (B/C), Pavement Sustainability

ASSESSMENT OF VITAMIN D THERAPY EFFECT ON INFLAMMATORY MARKERS IN PEDIATRIC PATIENTS WITH TYPE I DIABETIC

Objective: The objective of this study is to estimate the effect of Vitamin D3 supplementation on endogenous Vitamin D3 level and inflammatory biomarkers in newly diagnosed pediatric patients.Methods: The patients were given oral Vitamin D3, and they divided into three groups: The first group (25 healthy pediatrics), the second group (25 newly diagnosed pediatric patients) treated with daily insulin regimen only, and the third group (25 newly diagnosed pediatric patients) treated with Vitamin D3 (2000 IU/day) with daily insulin regimen; all patients were treated for 90 days; and blood samples were taken at baseline and after 45 days and 90 days of starting Vitamin D3 to assess its potential effect on the levels of Vitamin D, serum calcium, serum alkaline phosphatase levels, and other inflammatory markers.Results: The results of the current study showed that serum IL-1β significantly declined in patients receiving Vitamin D3, while serum Vitamin D3, serum calcium, and interleukins-4 were significantly increased in patients receiving Vitamin D3.Conclusion: Vitamin D3 in a daily dose of 2000 IU/day for 90 days results in favorable immune response and increase of serum Vitamin D3 for pediatric new diagnosed Type 1 diabetes mellitus patients

The Elk1 gene effect on prostate cancer cell line wound healing ability

In this study prostate cancer cell line model was used selecting three type of them (Pc3, DU145 & LNCaP) , gene transfecting was done by using the liposome into the cell culture cells then detecting the healing ability by the Wound Healing or (scratching) test that shows clear effect of ELK1 gene in this cells comparing with the control cell transfected with the knock down gene, using for each type of cells 6 repeats ,for each type there was two groups 1st for control ELK1 and the 2nd was knock down or (sh) ELK1, all works was done in Johns Hopkins University / School of Medicine / Pathology Department ( MD, USA

ELK1 Gene Transfection Effect in Prostate Cancer Cell Line Proliferation Activity

Three type of prostate cancer cell line was selected for this study (PC3, DU145 & LNCaP) as a model, transfected by liposome with the ELK1 gene ( control & knock down) , then detecting the proliferation ability of the cultured cell lines by the Mtt or (proliferation) assay that shows clear effect of ELK1 gene in this cells comparing with the control cell transfected with the knock down gene, using for each type of cells 6 repeats ,for each type there was two groups 1st for control ELK1 and the 2nd was knock down or (sh) ELK1, all works was done in Johns Hopkins University / School of Medicine / Pathology Department ( MD, USA

Experimental study for elastic deformation under isolated footing

The results of field studies of elastic deformations in the footing base, composed of loses soils. Elastic deformation is the result of compression partially bound water at the contacts between the mineral particles, the value of which depends on the wetness soil environment. It was found that deformation depends on the molecular moisture capacity of the soil while elastic settlement increases in proportion to pressur

An Experimental Study on Behavior of Sustainable Rubberized Concrete Mixes

In terms of recycling and reuse, today's global generation of waste tire well exceeds its consumption. This has resulted in the accumulation of large stocks of toxic rubber waste that raise health and safety risks. The use of waste tire rubber for the construction of the concrete structure was suggested to combat this challenge. This paper explores tests that were performed with samples of waste tire rubber concrete to evaluate compressive strength, flexural tensile strength, modulus of rupture, and impacts resistance. The main parameters investigated were the rubber ratio as a partial volumetric replacement with fine and coarse aggregate. Chip and crumb rubbers were used to replace coarse and fine aggregate respectively in four different amounts by volume (5%, 10%, 15%, and 20%). Even if the inclusion of waste tire rubber in concrete has specific apparent degradations, the potential benefit seems to overlook the adverse effects and also meet the primary significant value of resolution for rubber waste utilization problems. The results show that the substitution of natural fine or coarse aggregates with crump-chip tier rubber will reduce mechanical properties (compressive, flexural and splitting tensile strength), but increase the impacts resistance to 426% and 396% when 20% coarse aggregates and 20% fine aggregates are replaced by rubber respectively. The proposed mix shows an ability to replace 20% of the aggregate (coarse or fine), and the producing, rubcrete, still structural concrete