Biopolymers

Significant progress has been made on biopolymers in recent years. Biopolymers are preferred to other materials because they have specific physical, chemical, biological, biomechanical, and degradation properties. Many natural or synthetic biopolymers can degrade hydrolytically or enzymatically and are used for many applications

Understanding associations between rheumatoid arthritis and associated biomarkers with brain and psychological health in the UK Biobank

Rheumatoid arthritis (RA) is the most prevalent chronic inflammatory condition affecting the joints, that if left untreated can result in permanent damage and reduced quality of life. The general focus of RA literature and treatment has been on pain, inflammation and maintaining joint function, with limited research on psychological factors such as mental health, sleep and cognition, and an almost complete gap for structural brain differences (vs. people without RA). Similarly, more research is needed to understand the role of rheumatoid factor (RF), an autoantibody that is used in the official classification criteria for RA. This thesis aimed to fill in these gaps in the literature, with the overall aim of investigating whether RA/RF positive (RF+) are associated with differences in mental health, sleep, cognition, and structural brain health. This thesis used data from a relatively large cohort, the UK Biobank, covering approximately 500,000 people for the baseline visit and around 40,000 participants for the imaging visit to test for associations between RA/RF and mental health, sleep, and cognition in Chapter 3; associations between RA/RF and structural brain phenotypes in Chapter 4; and associations between increased polygenic risk for RF with structural brain and cognitive differences in Chapter 5. Compared to previous studies, the current thesis had the advantage of using a very large cohort that also enabled me to control for a variety of confounders that have largely been neglected in previous literature. Chapter 3 provides evidence that self-reported RA is associated with higher neuroticism, worse sleep, and worse performance on cognitive tests for reaction time and fluid intelligence while RF+ status was associated with worse sleep. Chapter 4 suggested that self-reported RA is associated with a higher volume of white matter lesions, higher volume of the caudate, and a smaller volume for the amygdala. Chapter 5 found that a polygenic risk score (PRS) for RF was associated with markers of healthier white matter, more specifically lower volume of lesions and lower mean diffusivity, and better performance on a cognitive test for visuo-spatial processing and short-term memory. This thesis provided evidence that people with RA/RF+ status might present with differences in psychological and brain structure health that are currently unaddressed and untreated in the clinic despite being important contributors to overall health, as well as health-related quality of life. Considering that it is still unclear what exactly causes RA, as well as why some people respond well to treatments while others do not benefit from medication at all, this thesis suggests that future research should further aim for a better understanding of blood biomarkers, genetic risk factors, and psychological and brain health differences associated with RA. This could aid diagnosis, disease stratification, treatment, and health interventions, as well as a better understanding of comorbid risk factors

Soil Treatment Technologies through Bioremediation

Bioremediation includes processes such as bioventing, bioaugmentation, phytoremediation, biopiles, and composting. In this chapter, we details the characteristics, utilization and operating conditions of each process. Bioremediation is understood, according to the general definition, as the use of living organisms (microorganisms, plants, etc.) to improve and restore the ecological condition of a polluted or degraded substrate (area, land, aquifer, etc.) to better, favorable quality parameters life, harmless, non-polluting or to return it to its previous state. Soil treatment technologies through bioremediation include two types of treatments: in situ biological treatments (bioventilation, bioaugmentation, phytoremediation in soil) and ex situ biological treatments of polluted soils (biopiles and soil cultivation)

Evolution of the Rheological Behavior of Palm Oil

Palm oil is dark yellow to red with a sweet taste and violet scent. Under the action of oxygen in the air, palm oil discolors due to the oxidation of carotene. The sample at different temperatures was recorded at different shear rates. Based on the rheograms (graph of the average shear stress versus shear rate), the studied ones proved to be Newtonian fluid. The shear range used did not significantly affect the absolute viscosities of the palm oil at different temperatures. The absolute viscosities of palm oil have decreased with increasing temperature and can be equipped with an Arrhenius-type relationship

Increased cognitive demands boost the spatial interference effect in bimanual pointing

Peer reviewedPublisher PD

Self-compacting concrete: a comparison between the workability properties, density, porosity and mechanical properties

This paper highlights some connections between the workability properties of self-compacting concrete and the density of the concrete mass and between mechanical properties of compression strength and porosity of concrete samples investigated at 28 days of free curing. Also are presented properties of raw materials used in this study

Polymer concrete, correlations between properties

Has been adopted new method for determining the fluidity concrete with polymers. In the research were used three types of polymer: epoxy resin - at a rate of 10%; polyurethane - at a rate of 10% methylcellulose - at a rate of 0.6%. The experimental results showed that the same water/cement material behaves differently depending on the polymer used. Moreover, epoxy resin gives significant improvements in workability and strength. It was found that the polymer influence positively the mechanical properties and concrete workability. Were performed mycroscopical investigations on reinforced concrete structures

Properties of polymer modified concrete in fresh and hardened state

It was carried out a study on the properties of polymer modified concrete (PCM) in fresh and hardened state. It was used three types of polymers: epoxy resins, polyurethane and methylcellulose in different percentages and different water cement ratio. The main objectives was to improve workability and rheological behavior of these mixtures in fresh state and mechanical strength tests on hard concrete. Has been investigated the polymer influence on compression strength and flexural strength and analyzing the time evolution of these strengths and participation of polymer in the microstructure formation.This work was partly financed by the European Social Fund through the POSDRU/CPP107/DMI1.5/S/77497 Program for PhD. Studen