Introduction: Heart failure remains a major public health problem, with recent estimates indicating that end-stage heart failure with two-year mortality rates of 70-80% affects over 60,000 patients in the US each year. Medical management can be used but success declines for patients with end stage heart failure. Although cardiac transplantation is optimal, less than 2500 cardiac transplants are performed annually due to the severely limited supply of donor organs. Mechanical circulatory support (MCS) devices are now routinely used to bridge patients with end-stage heart failure who become critically ill until a donor heart is available. The use of stem cell therapy to treat heart failure has been gaining significant ground in recent years, specifically due to its regenerative properties, and both animal and human models have shown significant improvements in ventricular mass, ejection fraction, vascularization, wall thickness, and infarct size reduction. Using the patients' HeartWare HVAD device diagnostics, we were able to acquire our response variable; pulsatility. Pulsatility is a variable measure of the differential between minimum and maximum flow and is dependent on device motor speed, power, current, and fluid viscosity. This measurement is important as it relates to the contractility of the heart and could potentially be used as an end point in determining when a patient is healthy enough to have their HVAD explanted. We set out to develop a low cost and effective predictive model to determine amniotic mesenchymal stem cell's ability to repair compromised cardiac tissue of patients using the Total Artificial Heart (TAH) and Donovan Mock Circulation Tank (DMC). Methods: Predictive modelling was performed using the TAH and DMC. The system was set to a range from critical heart failure to a normal operating conditions through the variation of preload, afterload, and ventricular drive pressures with the intent of comparing the results to our patient population. Patients (n=7, 3 dilated, 4 ischemic) received intravenous and intra-myocardial injections of a heterogeneous amniotic mesenchymal stem cells mixture and liquid matrix (MSCs+LM) at HVAD implant. Groups were analyzed based on treatment; control (HVAD only, n=7) versus stem cells (HVAD + MSCs+LM). HeartWare log files were acquired from patients' devices and analyzed in SAS and Matlab. Results from the patient study were compared to the predictive model to determine levels of stem cell response. Results: Pulsatility was found to increase with left drive pressure and afterload. Lower drive pressures resulted in a drop off in pulsatility at higher afterloads while higher drive pressures were able to compensate for any afterload. Pulsatility also increased with preload but lower drive pressures were unable to fully eject at the highest preloads, resulting in a reduced pulsatility. We observed the effects of the stem cell injections on pulsatility and found that patients receiving therapy demonstrated statistically significant increases in pulsatility at 15-20 (p=.0487), 25-30 (p=.0131), 35-40 (p=.0333), and 75-80 (p=0.0476) days post implant. At minimum, when comparing the patient results to the in vitro model, the therapy resulted in a progression from end stage HF conditions to medium cardiac function conditions. At maximum, the therapy resulted in a progression from end stage HF to normal healthy operating cardiac function. Conclusions: Stem cells demonstrated a significantly increased rate of change in pulsatility within the first 40 days and at 80 days post implant when compared to control. They also demonstrated progression from end stage HF to normal healthy cardiac function at two time periods (Days 40, 90). These results justify expansion of the study to encompass a larger patient population to verify the results of the in vitro model to predict cardiac regeneration with multiple functional status indicators.

This research study investigates the effect of micronized copper azole type C (MCA-C) preservative system on the rolling shear (RS) properties of CLT. In the first part of research, bonding performance of CLT panels treated at two retention levels, 0.96 kg/m3 and 2.5 kg/m3, were evaluated. Three structural adhesive systems, melamine formaldehyde (MF), resorcinol formaldehyde (RF) and one-component polyurethane (1C-PUR) were used to assemble visually graded No. 2 2×6 southern yellow pine (SYP) lumber while manufacturing CLT panels. For treated CLT panels, 1C-PUR provides better bonding performance test results. The RS properties of MCA-C treated CLT panels were studied in the second part of the research. The CLT panels were subjected to out-of-plane loading according to the EN 16351 standard. The mean values of RS strength and modulus of treated CLT were 1.89 MPa and 289.4 MPa respectively.

More than one billion vehicle tires reach the end of their useful service life annually. Less than a quarter of rubber waste is reused or recycled in some way. Interest has grown in working to discover means by which to incorporate rubber tire waste into construction materials. This study sought to delve into the use of micronized rubber powder (MRP) as an acoustic agent within particleboard and concrete. In addition, work was conducted to characterize the effect that MRP has on the strength and flexural properties of concrete. Furthermore, research sought to provide insight into how pine biomass, a forest products industry waste, would interact with MRP in concrete as it relates to strength and acoustic properties. As expected, particleboard that contained MRP resulted in lower strength but higher flexibility. Acoustic testing revealed that there was minimal sound absorption improvement at some frequencies and less absorption at low and high frequencies. Sound transmission loss was slightly improved by the addition of MRP to the particleboard. Adding pine biomass and MRP to concrete yielded much lower compressive strength as compared to plain concrete. Visual inspection of the sound absorption coefficient curves over the full range of test frequencies identified limited, if any, advantage for the addition of MRP or biomass. Some ranges of frequencies offered minimal improvement. There appeared to be no appreciable sound absorption advantage to adding MRP, pine biomass, or the combination of the two into concrete mix proportions. Modulus of rigidity was decreased as compared to plain concrete when MRP, pine biomass, or a combination of both were incorporated into the concrete mixture as volume replacement for aggregate. Visual observation revealed that flexural failure for the MRP or pine beams were less sudden and less catastrophic than the plain concrete samples. Modulus of elasticity was decreased as compared to plain concrete when MRP, pine biomass, or a combination of both were incorporated into the concrete mixture as volume replacement for aggregate. The more flexible and ductile concrete produced with MRP and biomass provides a combination of properties that serve to lessen the propagation of cracks throughout the specimen.

Specially designed non-damaging lost circulation pills (LCP) are being effectively applied for drilling depleted zones worldwide. Optimizing the LCP compositions stop the lost circulation effectively and protect the production zone from liquid and solids invasion significantly. Shape, particle size distribution and concentration of the lost circulation materials (LCM) are key parameters determining the effectiveness of LCP. In this study, the Permeability Plugging Apparatus (PPA) is utilized to evaluate effectiveness of various LCM&rsquo / s in curing the lost circulation. Sized calcium carbonates are used as LCM in different concentrations and in different particle size distribution. Lost circulation zones are simulated using the ceramic disks and slotted disks. Ceramic disks with nominal pore sizes 20, 35, 60, 90, and 150 microns are characterized in terms of pore size distribution using the computerized image analysis technique. Filter cake quality, spurt loss and filtrate volume are basic parameters to be evaluated in this study. Tests are performed at 75 F and 300 psi of differential.

La poudre de polyuréthane à base de déchets de mousse de polyuréthane a des capacités de liant classique sous certaines conditions. Ceci est très intéressant du point de vue écologique car cela permet de rallonger le cycle de vie du polyuréthane et d’économiser le premier substituant de la colle classique qui est produit à partir de 100% de matière première. Le but de cette étude était d’améliorer l’application de la poudre de polyuréthane, comme substituant de la colle pMDI, dans la production des panneaux OSB. Une importante partie de ce travail était de mieux comprendre la réactivation de la poudre de polyuréthane et les conditions nécessaires pour que la poudre puisse fonctionner de façon optimale. Des résultats de recherche ont montré que l’uréthane est dégradé à une température de 165°C en groupements d’isocyanate et de polyols. La formation d’isocyanate à pu être démontrée par plusieurs méthodes. Le savoir a été généré dans des laboratoires et confirmé avec des essais pratiques sur des lignes industrielles. Un des objectifs principaux de ce travail était de baisser la température de décomposition de la poudre de polyuréthane à un niveau suffisamment bas pour que la poudre puisse être utilisée non seulement dans les couches externes mais aussi dans la couche médiane du panneau. Dans la première phase de ce travail la poudre de polyuréthane sans additifs a été analysée. Ensuite une sélection entre différents catalyseurs utilisés dans la production de mousse de polyuréthane a été effectuée. Pour pouvoir quantifier la capacité du catalyseur une machine permettant de produire des disques à base de polyuréthane pur a été développée. Cette machine a fourni la base pour pouvoir sélectionner le catalyseur le plus performant. Ainsi cette machine donne à l’entreprise Mobius Technologies une très bonne et simple solution pour déterminer les propriétés de la poudre de polyuréthane traitée ou non traitée et pour en déterminer la qualité. Enfin, les résultats de la recherche ont pu être mis en application à l’échelle industrielle sur des lignes industrielles d’OSB chez les entreprises Kronoply, Kronofrance et chez un producteur d’outre-mer qui reste anonyme dans ce document pour des raisons de discrétion liée à l’entreprise Mobius Technologies. Il a été possible de baisser la température de décomposition de la poudre jusqu’à 147°C, grâce au catalyseur employé. L’objectif de 120°C comme température de décomposition n’a donc pas été atteint / The polyurethane powder based on recycled material or polyurethane slab stocks shows bonding properties under certain circumstances. This is interesting from the ecological point of view, because the product life cycle of the polyurethane is prolonged. In addition to that the powder can be used as substitute for standard adhesives which are produced on 100% non renewable recourses. The goal of this project was the improvement of the application of polyurethane powder, as substitute of pMDI-adhesives, which are used in the production of OSB boards. One mayor aspect of the study was the understanding of the reactivation of the polyurethane powder and to find out the conditions for an optimized use of the powder. The results of the research demonstrated that at the degradation temperature of about 165°C the urethane bond is decomposed in to isocyanates and polyols, which is already well known in polyurethane chemistry. The reverse reaction to polyurethanes could be proved by several methods. This was than in lab scale and also under industrial conditions. The main objective of the present study was to lower the activation temperature of the polyurethane powder as pMDI adhesive substitute in the core and the surface layer of wood based panels. In the start-up phase the polyurethane powder was used an analysed without any additives. Later on a selection of different typical polyurethane catalysts were used. To quantify the efficiency of different catalysts a special machine was constructed. This new developed machine provided us with the results to select the most performing catalyst. In addition this machine was used as an easy and efficient quality control tool of Mobius Technologies. The results were used to apply the polyurethane powder on industrial production units of Kronoply (Germany), Kronofrance (France) and unstated OSB-producer in overseas. It was possible to lower the activation temperature by the use of a catalyst to about 147°C. The ambitious intent to reach a temperature of 120°C was not achieved

This diploma thesis deals with the issue of using fine powder of concrete recyclate. In this thesis, the theoretical expectations of milling are summarized as well as high energy milling. Afterwards professional articles, in which fine powder of concrete recyclate is successfully activated, are described and commented on. In the experimental part, there are 11 recipes of cement mortar and 3 recipes of concrete mixed. The benefit of using fine powder of concrete recyclate as a possible substitute for part of the cement is evaluated.

The diploma thesis describes admixtures for concrete. It deals with the influence of admixtures on the properties of cement composites in the fresh and hardened state. The theoretical part described the individual components of concrete, where the main attention was focused to inert admixtures and their effect on mechanical properties, shrinkage, resistance of cement composites to aggressive medium. Furthermore, the effect of admixtures on concretes with recycled aggregates was described. In the first stage of the practical part, cement mortars with 25, 35 and 50% replacement of cement admixtures were created. In the second stage, concretes with admixtures and a minimum strength class of C30/37 and C50/60 were created. Finely ground granulated slag, micronized limestone and granite stone dust were used as admixtures in mortars and concretes. The change of properties in the fresh and hardened state was observed on cement composites.

This thesis focuses on collecting all available data on mixing Portland cements and especially on Portland cements with limestone. In the experimental part are compare the rheological properities of mixing Portland cements with limestone, their compatibility with plasticizing additives, witch depends on the type of additives, dosage and time, then in experimental part they are summarized monitoring of physical-mechanical properties and volume changes of concrete.

Interest in the use of mass timber in building and construction is growing worldwide, this is due to the structural integrity and reduced environmental footprint of timber-based structures. Concerns associated with the biological and environmental degradation of mass timber necessitate the development of adequate protection strategies to ensure the durability of these products. Preservative treatment is a proven technique that increases the durability and performance of wood in-service and can also be applied to large-sized timber panels such as cross-laminated timber (CLT). Therefore, this study focused on investigating the feasibility of treating prefabricated 3- and 5-layer CLT panels with Copper-azole type C (CA-C) and micronized copper azole (MCA) preservatives. Further, we studied the effects of panel layup and thickness on the preservative impregnation in CLT. Based on the experimental results, we found adequate preservative penetration and retention in the treated 3- and 5-layer CLT panels, particularly in CA-C treated panels. Also, the lengthwise layup shows better treatment results in both CA-C and MCA-treated panels. In addition to the preservative-treatment of CLT panels, this dissertation covers the development of lignin-reinforced polyurethane adhesive (PUR) for bonding glue-laminated timber (Glulam). Herein, the glulam were fabricated and bonded using lignin-reinforced PUR at different wt% (1, 2, and 3) and tested for shear strength, wood failure and delamination. The lignin-treated PUR samples showed improved adhesion properties via high shear strength and reduced delamination compared to the control specimens. Thus, the lignin-reinforced PUR adhesive shows great potential as a bio-based and environment-friendly wood adhesive for producing glulam used in structural applications.