Modelling and experimental investigation of magnetic flux leakage distribution for hairline crack detection and characterization

The Magnetic Flux Leakage (MFL) method is a well-established branch of electromagnetic Non-Destructive Evaluation (NDE) extensively used to assess the physical condition of ferromagnetic structures. The main research objective of this research work presented in this thesis is the detection and characterization of the MFL distribution caused by rectangular surface and far-surface hairline cracks. It looks at the use of the direct current and pulsed current techniques to investigate the presence of hairline cracks in ferromagnetic steel pipelines, by comparing the Finite Element Modelling (FEM) technique with practical experiments. First, the expected response of an MFL probe scanned across the area of a hairline crack was predicted using the 3D FEM numerical simulation technique. The axial magnetization technique is employed and the characteristics of the surface and far-surface leakage field profile

Collagen triple-helix repeat containing 1 (CTHRC1) protein in rheumatoid arthritis patients: Relation to disease clinical, radiographic and ultrasound scores

Aim of the work: to study the relationship between collagen triple helix repeat containing 1 (CTHRC1) protein serum levels and disease activity, patients’ well-being, as well as ultrasonographic and radiological scores in patients with rheumatoid arthritis (RA). Patients and methods: The work included 70 RA patients and 70 age and gender matched controls. The disease activity score (DAS28) and health assessment questionnaire (HAQ) were assessed. Modified Larsen's score was used to score the hands and feet digital radiographs and musculoskeletal ultrasound (MSUS) examination using ultrasound-7 score was carried out. Serum CTHRC1 levels were measured by ELISA. Results: Patients were 62 females and 8 males (F: M 7.8:1), their mean age was 42.2 ± 17.7 years and median disease duration 15 years. The median CTHRC1 serum levels were significantly higher in patients (453 ng/dl; 158–688 ng/dl) than control (99 ng/dl; 67–179 ng/dl) (p < 0.001). CTHRC1 was significantly increased in those with high activity (p < 0.001).CTHRC1 levels significantly correlated with DAS28 (r = 0.87,p < 0.001), CRP (r = 0.43,p < 0.001) and total ultrasound-7 score (r = 0.27,p = 0.03). Only total US7 score (p = 0.003) and CTHRC1 (p < 0.001) were significant predictors of activity. Serum CTHRC1 could significantly differentiate between patients and controls at cut off 179 ng/ml; sensitivity 95.7 % and specificity 100 % (p < 0.001) and between patients active and in remission at cut off 324 ng/ml; sensitivity 92.2 % and specificity 94.7 % (p < 0.001). Conclusions: Patients with RA have significantly elevated serum levels of CTHRC1. In the process of structural bone ultrasonographic abnormalities as well as disease activity in RA patients, elevated CTHRC1 levels play a key role

Synthesis and Optical Properties of a Dithiolate/Phosphine-Protected Au₂₈ Nanocluster

While monothiols and simple phosphines are commonly exploited for size-controlled synthesis of atomically precise gold nanoclusters (NCs), dithiols or dithiol-phosphine combinations are seldom applied. Herein, we used a dithiol (benzene-1,3-dithiol, BDT) and a phosphine (triphenylphosphine, TPP) together as ligands and synthesized an atomically precise gold NC with the formula [Au₂₈(BDT)₄(TPP)₉]²⁺. This NC exhibited multiple absorption features and a charge of +2, which are distinctly different from the reported all-thiolated [Au₂₈(SR)₂₀]⁰ NC (SR: monothiolate). The composition of [Au₂₈(BDT)₄(TPP)₉]²⁺ NC was deduced from high-resolution electrospray ionization mass spectrometry (ESI MS) and it was further corroborated by thermogravimetric analysis (TGA). Differential pulse voltammetry (DPV) revealed a HOMO–LUMO gap of 1.27 eV, which is in good agreement with the energy gap of 1.3 eV obtained from its UV–vis spectrum. The successful synthesis of atomically precise, dithiol-protected Au₂₈ NC would stimulate theoretical and experimental research into bidentate ligands as a new path for expanding the library of different metal NCs, which have so far been dominated by monodentate thiols