Using Peripheral Venous Pressure Waveforms to Predict Key Hemodynamic Parameters

Analysis of peripheral venous pressure (PVP) waveforms is a novel method of monitoring intravascular volume. Two cohorts were used to study the hemodynamics change of the body state and its influence on the PVP using (1) dehydration setting with infants suffering from pyloric stenosis and (2) hemorrhage setting during a craniosynostosis elective surgery. The goal of this research is to develop a minimally invasive method of analyzing the PVP waveforms and find correlations with volume loss. Twenty-three pyloric stenosis patients PVP were acquired at five stages and were divided into euvolemic, normal fluid volume, and hypovolemic, significant fluid loss. Seven craniosynostosis patients were enrolled and the PVP was acquired at the intervention to explore if the isoflurane dosage influences the PVP. A multivariate analysis of variances (MANOVA) was used to test if the PVP was influenced by the volume change and the anesthetic drugs effect. Prediction algorithms based on Fast Fourier Transform were utilized at the two cohort patients analyses to classify an arbitrary PVP into its correct classification. Our research found that PVP signal is influenced by the different hemodynamics states of the body. Based on MANOVA outcomes, we built prediction systems and they were able to categorize an arbitrary PVP signal into its correct classification. The k-nearest neighbor (k-NN) model correctly predicted 77% of the data in the euvolemic and hypovolemic groups. The k-NN models of the anesthetic drugs were able to correctly predict correctly at least 85% of the preoperative and intraoperative signals of the pyloric stenosis patients and the different isoflurane dosages of the craniosynostosis patients. Analyzing the PVP signal is a promising tool for measuring the dehydration level in acute settings. Our results imply that the subsequent changes in vascular resistance due to inhaled and infused anesthetics are reflected in the peripheral veins. A technology that would accurately assess the volume status of a patient to guide triage and treatment would be a significant improvement in various care settings. This minimally invasive technology utilizes a standard peripheral intravenous line and a commercial pressure-monitoring transducer, which exist today and requires no new clinical skills

Amorphous phase formation in InxGa1-xAs, InxGa1-xP and Si1-xGex

Amorphous semiconductors have found uses in an increasing variety of electronic and photonic devices over the last few decades, many of which are now commonplace. The ubiquitous Thin Film Transistor (TFT) LCD/LED flat panel display is a multibillion dollar per annum industry. Other examples include photovoltaic cells and night vision systems. A thorough understanding of the physical characteristics of this class of materials is of commercial, military, scientific and technological interest. In particular, a deeper understanding of the amorphisation process may assist in accelerating the uptake of this technology. This thesis investigates the amorphisation kinetics of three semiconducting materials, InxGa1-xAs, InxGa1-xP and Si1-xGex, to gain an understanding of the damage production process in these materials via ion implantation. Ion implantation is a commonly used technique in the semiconductor industry for rendering materials amorphous due to the precise control it offers over the implanted ion fluence and ion species. All three of these materials are of technological importance for their use and development in fields such as solar cells for space applications, quantum well FETs, wireless LAN and GPS applications. Ion implantation was performed using Ge ions to render InxGa1-xAs, InxGa1-xP and Si1-xGex amorphous. Implantation induced disorder was quantified with Rutherford backscattering spectroscopy in the channelling configuration (RBS-C). EXAFS measurements were preformed to study the local atomic structure of the crystalline material. Parameters such as bond length, bond angle and structural disorder were deduced from the EXAFS measurements. These results were then correlated to RBSC to help explain the amorphisation behaviour observed in InxGa1-xAs, InxGa1-xP and Si1-xGex. It was found that distortion in both bond length and bond angle distribution was apparent for both InxGa1-xAs and InxGa1-xP with the structural disorder primarily being accommodated by bond angle distribution. This leads to the presence of local regions of strain acting as preferential sites for stimulated amorphisation. The amorphisation kinetics observed in InxGa1-xAs and InxGa1-xP are attributed to these pre-existing local strain regions. The structural disorder observed in crystalline Si1-xGex was much reduced in comparison to the InxGa1-xAs and InxGa1-xP. Hence, amorphisation kinetics observed in Si1-xGex differ from those observed in InxGa1-xAs and InxGa1-xP. It is hoped that the insights gained by this thesis into the amorphisation kinetics of these materials will help open up more avenues and application for the use of these and materials similar to these in the electronics industry

Graph Arrowing: Constructions and Complexity

Graph arrowing is concerned with determining which monochromatic subgraphs are unavoidable when coloring a given graph. There are two main avenues of research concerning arrowing: finding extremal Ramsey/Folkman graphs and categorizing the complexity of arrowing problems. Both avenues have been studied extensively for decades. In this thesis, we focus on graph arrowing problems where one of the monochromatic subgraphs being avoided is the path on three vertices, denoted as P3. Our main contributions involve computing Folkman numbers by generating graphs up to 13 vertices and proving the coNP-completeness of some arrowing problems using a novel reduction framework geared towards avoiding P3\u27s. The (P3,H)-Arrowing Problem asks whether a given graph can be colored using two colors (red and blue) such that there are no red P3\u27s and no blue H\u27s, where H is a fixed graph. The few previous hardness proofs for arrowing problems relied on ad-hoc, laborious constructions of gadgets. We introduce a general framework that can be used to prove the coNP-completeness of (P3,H)-arrowing problems. We search for gadgets computationally. These gadgets allow us to simulate variants of SAT, thus showing coNP-hardness. Finally, we use our (P3,H)-Arrowing hardness reductions to gain insight into variants of Monotone SAT. For fixed k in {4,5,6}, we show that Monotone SAT remains NP-complete under the following constraints: 1) each clause consists of exactly two unnegated literals or exactly k negated literals, 2) the variables in each clause are distinct, and 3) the number of times a variable occurs in the formula is bounded by a constant. For future work, we expect that the insight gained by our computationally assisted reductions will help us prove the complexity of other elusive arrowing problems

Allocation of dump load in islanded microgrid using the mixed-integer distributed ant colony optimization with robust backward\forward sweep load flow

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonReliable planning and operation of droop-controlled islanded microgrids (DCIMGs) is fundamental to expand microgrids (MGs) scalability and maximize renewable energy potential. Employing dump loads (DLs) is a promising solution to absorb excess generation during off-peak hours while keeping voltage and frequency within acceptable limits to meet international standards. Considering wind power and demand forecast uncertainties in DCIMG during off-peak hours, the allocation of DL problem was modelled as two problems, viz., deterministic and stochastic. The former problem was tackled using four highly probable deterministic generation and demand mismatch scenarios, while the latter problem was formulated within scenario based stochastic framework for uncertainty modelling. The mixed-integer distributed ant colony optimization (MIDACO) was introduced as a novel application in microgrids to find the optimal location and size of DL as well as the optimal droop setting for distributed generation (DG). Furthermore, to enhance the convergence of the proposed optimization technique, three robust and derivative free load flow methods were developed as novel extensions of the original backward\forward sweep (BFS) for grid-connected MGs. The three load flow methods are called special BFS, improved special BFS, and general BFS. The first two methods rely on one global voltage variable distributed among all DGs, while the latter has more general approach by adopting local voltage at each generating bus. The deterministic multi-objective optimization problem was formulated to minimize voltage and frequency deviation as well as power losses. Inversely, the stochastic multi-objective problem with uncertainty was formulated to minimize total microgrid cost, maximum voltage error, frequency deviation, and total energy loss. The proposed method was applied to the IEEE 33-, 69-, and 118-test systems as modelled in MATLAB environment and further validated against competitive swarm and evolutionary metaheuristics. Various convergence tests were considered to demonstrate the efficacy of the proposed load flow methods with MIDACO’s non-dominated solution. Likewise, different optimization parameters were utilized to investigate their impact on the solution. Moreover, the advantage of multi-objective optimization against single objective was provided for the deterministic optimization problem, while the effect of load model and droop response were also investigated. The obtained results in chapter 5 and 6 further demonstrate the fundamental role of DL in voltage and frequency regulation while minimizing costs and energy losses associated with DCIMG operation. Accordingly, an improved voltage and frequency profiles for the system after DL inclusion were attained in Figure 6.9 and Figure 6.10, respectively. To demonstrate the competitiveness of DL-based energy management system (EMS) against storage-based EMS, a brief cost benefit analysis considering hot water demand was also provided

Evaluation of Paroxonase and Interleukin-35, in Iraqi Female Patients with Multiple Sclerosis (MS) Disease

The present study was carried out to evaluate the effective role of PON and Il- 35 in serum female patients  with multiple sclerosis (MS). In this study , 30 females were enrolled , the duration of the disease was from 3 months to 2 years (Group2 G2) were taken from Baghdad teaching hospital through the period from April-2013 to – Dec.2013. They were compared with 30 apparently healthy females with the same range of age (20 to 30) years (Group 1 G1) .Results Showed high significant decrease of PON in Group 2 compared with Group 1 , while high significant increase in IL- 35 was noted in Group 2 compared with Group 1 .Besides , high significant positive Correlation was observed between PON and IL- 35 in both of Group 1 and Group 2. It was conclude that PON and IL -35 may be used as a clinical marker In Multiple Sclerosis disease. Keywords: Paroxonase, Multiple Sclerosis, Interleukine -35

Chipping, failure load and fatigue resistance of anterior veneers manufactured with CAD/CAM technology

OBJECTIVES: To evaluate the marginal chipping of anterior veneers made with CAD/CAM by calculating the chipping factor, to evaluate the failure load of different veneering materials and thicknesses under static loading and cyclic loading. MATERIALS AND METHODS: An ivorine central incisor was prepared to receive a traditional veneer. Using epoxy resin, 120 replication dies were made of the prepared tooth. Four ceramic materials were used; IPS Empress CAD, IPS e.max CAD, VITA ENAMIC and Lava Ultimate. Veneers were milled using a Sirona InLab MCXL at three different thicknesses, 0.4mm, 0.7mm and 1.0mm, n=10 for each group. Veneers were inspected under the light microscope to calculate the chipping factor (CF). All veneers were cemented to their tooth replicas using Variolink Veneer resin cement. Five specimens/group were loaded under compression using an Instron universal testing machine at a rate of 0.5 mm/minute until fracture. Another five specimens were subjected to cyclic loading at 30% of the mean fracture load for 30,000 cycles at frequency rate of 1 Hz, and then were loaded under compression to fracture. Modes of failure were recorded after each test. RESULTS: IPS Empress CAD 0.4mm CF was higher than all other groups, and VITA ENAMIC and Lava Ultimate 1.0mm CF were the lowest. There was a significant difference in the failure load of the IPS Empress CAD and IPS e.max CAD groups under static loading but not in VITA EANMIC and Lava Ultimate groups. Cyclic fatigue had no significant effect on the failure load of different veneering materials and thicknesses. CONCLUSIONS: Chipping factor decreases as the material thickness increases and can be used as an indicator of material machinability. IPS e.max CAD at 1.0mm had the highest static failure load value when compared to other materials. Cyclic fatigue did not affect the failure load values within the groups tested.2019-09-26T00:00:00

The Role of Social Capital on Customers Knowledge Sharing Outcomes and CRM Success

Customer knowledge sharing (CKS) is a new dimension of knowledge sharing themes and interaction practices between firms and their customers. This study explores substantial involvement of social capital theory to customer knowledge sharing and CRM success. Proposed model integrates ideologies capital of relational, cognitive and others i.e. (trustworthiness, shared norms, shared language, customer experience, and degree of customer loyalty) potentially effect on sharing customers knowledge to improved CRM success. Structural equation modeling used to analyze exploratory and confirmatory factor analysis. The findings of this study indicate that there is a positive responsiveness of CRM success by the social capital dimensions. Keywords: Social capital, customers knowledge sharing, CRM, SEM