Numerical investigation of a single bubble and a pair of bubbles rising in Newtonian and non Newtonian fluids with interfacial passive scalar transfer

Aquesta tesi explora el comportament de les bombolles i la seva interacció amb fluids en diferents processos industrials. L'estudi es centra en la dinàmica d'elevació d'una bombolla de gas única i d'un parell de bombolle diferents tipus de fluids, i en la transferència de calor/massa de les bombolles als fluids circumdants. La simulació es realitza utilitzant Basilisk, amb tècniques de refinament de malla adaptatives. Els resultats mostren que la dinàmica d'una bombolla única està fortament influïda pel índex de flux i les propietats reològiques del fluid. El camp de viscositat i la forma de la bombolla estan significativament afectats per les propietats reològiques del fluid. La taxa de transferència de massa augmenta amb el nombre de Peclet i depèn molt de l'índex de flux. El comportament de dues bombolles que s'elevin en línia es caracteritza per diferents patrons de moviment. La taxa de transferència de calor/ massa s'optimitza en règims en què les bombolles segueixen escenaris d'escapada lateral o de Drafting-Kissing- Tumbling. La relació de radi entre la bombolla líder i la que la segueix té un impacte significatiu en el comportament de les bombolles durant l'elevació. La constant de temps inelàstica influeix en el comportament de les bombolles durant l'elevació, provocant més inestabilitat i moviment oscil·latori de les bombolles. L'índex de flux és un paràmetre reològic crucial que afecta el comportament de les bom dueix a un augment de les inestabilitats de la bombolla durant l'elevació.Esta tesis explora el comportamiento de burbujas y su interacción con fluidos en diferentes procesos industriales. El estudio se enfoca en la dinámica de ascenso de una sola burbuja de gas y de un par de burbujas en diferentes tipos de fluidos, y la transferencia de calor/masa de las burbujas hacia los fluidos circundantes. La simulación se lleva a cabo utilizando Basilisk, con técnicas de refinamiento de malla adaptativa. Los resultados muestran que la dinámica de una sola burbuja está fuertemente influenciada por el índice de flujo y las propiedades reológicas del fluido. El campo de viscosidad y la forma de la burbuja son significativamente afectados por las propiedades reológicas del fluido. La tasa de transferencia de masa aumenta con el número de Peclet y depende mucho del índice de flujo. El comportamiento de dos burbujas ascendentes en línea se caracteriza por diversos patrones de movimiento. La tasa de transferencia de calor/masa se optimiza en regímenes donde las burbujas siguen patrones de escape lateral o de "Drafting-Kissing-Tumbling". La relación de radio entre la burbuja líder y la burbuja en la retaguardia tiene un impacto significativo en el comportamiento de las burbujas durante su ascenso. La constante de tiempo inelástica influye en el comportamiento de las burbujas durante su ascenso, lo que lleva a una mayor inestabilidad y movimiento oscilatorio de las burbujas. El índice de flujo es un parámetro reológico crucial que afecta el comportamiento de las burbu la disminución del índice de flujo conduce a un aumento en las inestabilidades de la burbuja durante su ascenso.This thesis explores the behavior of bubbles and their interaction with fluids in different industrial processes such as wastewater treatment, and chemical reactions. The study focuses on the rising dynamics of a single gas bubble and a pair of bubbles in different types of fluids, and the heat/mass transfer from the bubbles into the surrounding fluids. The simulation is carried out using Basilisk, with adaptive mesh refinement techniques. The results show that the dynamics of a single bubble are strongly influenced by the flow index and the rheological properties of the fluid. The viscosity field and bubble shape are significantly affected by the rheological properties of the fluid. The mass transfer rate increases with the Peclet number and is highly dependent on the flow index. The behavior of two bubbles rising in-line is characterized by various motion patterns. The heat/mass transfer rate is optimized in regimes where the bubbles follow side escape or Drafting-Kissing-Tumbling scenarios. The radius ratio of the leading to trailing bubble has a significant impact on the behavior of bubbles during rising. The inelastic time constant influences the behavior of bubbles during rising, leading to more instability and oscillatory motion of the bubbles. The flow index is a crucial rheological parameter that affects the behavior of bubbles, and decreasing the flow index leads to an increase in the instabilities of the bubble during rising

Influence of p53 (rs1625895) polymorphism in kidney transplant recipients

Reperfusion injury predisposes the kidney allograft to acute rejection. Apoptosis is a mechanism that results in graft injury, and TP53 is an important involved gene. To determine the association between single nucleotide polymorphism (SNP) in the pro-apoptotic protein p53 (rs1625895) and acute rejection in renal transplants, we studied 100 recipients of kidney allografts and 100 healthy individuals served as controls. The polymorphism was determined by the polymerase chain reaction restriction-fragment length polymorphism (PCR-RFLP) test. Overall, 31 recipients developed rejection. There was no difference in the genotype frequencies between the recipients and the controls. However, we found a difference of genotype and allele frequencies between recipients with and those without rejection. The WW genotype was more frequent in recipients with rejection. Although rejection is a complex immunologic event and functional importance of SNPs has not been confirmed yet, we suggest that wild type p53 may promote apoptosis during inflammation

Earlier Detection of Alzheimer’s Disease Based on a Novel Biomarker <em>cis</em> P-tau by a Label-Free Electrochemical Immunosensor

Early detection of cis phosphorylated tau (cis P-tau) may help as an effective treatment to control the progression of Alzheimer’s disease (AD). Recently, we introduced for the first time a monoclonal antibody (mAb) with high affinity against cis P-tau. In this study, the cis P-tau mAb was utilized to develop a label-free immunosensor. The antibody was immobilized onto a gold electrode and the electrochemical responses to the analyte were acquired by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The immunosensor was capable of selective detection of cis P-tau among non-specific targets like trans P-tau and major plasma proteins. A wide concentration range (10 × 10−14 M–3.0 × 10−9 M) of cis P-tau was measured in PBS and human serum matrices with a limit of detection of 0.02 and 0.05 pM, respectively. Clinical applicability of the immunosensor was suggested by its long-term storage stability and successful detection of cis P-tau in real samples of cerebrospinal fluid (CSF) and blood serum collected from human patients at different stages of AD. These results suggest that this simple immunosensor may find great application in clinical settings for early detection of AD which is an unmet urgent need in today’s healthcare services