Adaptive Gradient Assisted Robust Optimization with Applications to LNG Plant Enhancement

About 8% of the natural gas feed to a Liquefied Natural Gas (LNG) plant is consumed for liquefaction. A significant challenge in optimizing engineering systems, including LNG plants, is the issue of uncertainty. To exemplify, each natural gas field has a different gas composition, which imposes an important uncertainty in LNG plant design. One class of optimization techniques that can handle uncertainty is robust optimization. A robust optimum is one that is both optimum and relatively insensitive to the uncertainty. For instance, a mobile LNG plant should be both energy efficient and its performance be insensitive to the natural gas composition. In this dissertation to enhance the energy efficiency of the LNG plants, first, several new options are investigated. These options involve both liquefaction cycle enhancements and driver cycle (i.e., power plant) enhancements. Two new liquefaction cycle enhancement options are proposed and studied. For enhancing the diver cycle performance, ten novel driver cycle configurations for propane pre-cooled mixed refrigerant cycles are proposed, explored and compared with five different conventional driver cycle options. Also, two novel robust optimization techniques applicable to black-box engineering problems are developed. The first method is called gradient assisted robust optimization (GARO) that has a built-in numerical verification scheme. The other method is called quasi-concave gradient assisted robust optimization (QC-GARO). QC-GARO has a built-in robustness verification that is tailored for problems with quasi-concave functions with respect to uncertain variables. The performance of GARO and QC-GARO methods is evaluated by using seventeen numerical and engineering test problems and comparing their results against three previous methods from the literature. Based on the results it was found that, compared to the previous considered methods, GARO was the only one that could solve all test problems but with a higher computational effort compared to QC-GARO. QC-GARO's computational cost was in the same order of magnitude as the fastest previous method from the literature though it was not able to solve all the test problems. Lastly the GARO robust optimization method is used to devise a refrigerant for LNG plants that is relatively insensitive to the uncertainty from natural gas mixture composition

Salivary and serum anti-desmoglein 1 and 3 ELISA and indirect immunofluorescence in pemphigus vulgaris: Correlations with serum ELISA, indirect immunofluorescence and disease severity

Anti-desmoglein (anti-Dsg) ELISA and indirect immunofluorescence (IIF) are used for the diagnosis of pemphigus vulgaris (PV). The value of salivary ELISA, serum ELISA, and IIF in the diagnosis of PV, and the correlation of salivary anti-Dsg1 and anti-Dsg3 ELISA with serum ELISA, serum and salivary IIF titers, and disease severity in patients with PV were evaluated. Fifty newly diagnosed patients with PV were enrolled in the study. Demographic data and disease-severity scores were recorded for each patient. Anti-Dsg1 and anti-Dsg3 ELISA and IIF were performed on both serum and salivary samples. Given the cut-off value of 20 RU/mL for Dsg1 and Dsg3, serum Dsg1 and Dsg3 ELISA were positive in 41 (82%) and 40 (80%) patients, and saliva Dsg1 and the Dsg3 ELISA were positive in 2 (4%) and 3 (6%) patients, respectively. Using the cut-off value of 13.4 RU/mL and 7.7 RU/mL for Dsg3 and Dsg1 salivary ELISA, 25 (50%) and 23 (46%) patients tested positive for Dsg3 and Dsg1, respectively. Serum IIF results were positive in 35 (70%) patients, and salivary IIF results were positive in 16 (32%) patients. Salivary anti-Dsg1 and anti-Dsg3 showed moderate correlations with the total pemphigus disease area index (PDAI) score (r=0.466, P&lt;0.001), (r=0.459, P&lt;0.001), respectively. A moderate correlation between serum IIF and salivary IIF was also detected (r=0.413, P&lt;0.001). Salivary anti-Dsg1 and anti-Dsg3 ELISA could be used as a safe and noninvasive method for the diagnosis of PV under certain circumstances, especially in children or elderly patients. Salivary ELISA is superior to salivary IIF. </p

Immunological cross reaction between cancer cells and hydatid cyst

Background and aims: Hydatid cyst is the larval stage of the tape worm Echinococcu granulosus. Anticancer effects of some parasites have been shown. Moreover, existence of common antigens between some parasites especially hydatid cyst and cancers have been reported. So, immunological cross reaction between hydatid cyst and cancer cell antigens has been investigated in this study. Methods: In this laboratory descriptive study, different hydatid cyst antigens were prepared and antibody raised against them in rabbits. In dot immunoblotting, those antigens were probed with sera of patients with cancers (collected from Imam Hossein Hospital in Isfahan). Also, cross reaction among excretory secretory products of cancer cells and antisera raised against different hydatid cyst antigen was investigated. In order to remove carbohydrate bands of antigens, sodium periodate buffer was used. Results: Antisera raised against laminated & germinal layers of hydatid cyst reacted with excretory secretory products of cancer cells. Also, antigens of hydatid cysts reacted with cancer patients sera. Carbohydrate bands of antigens were involved in some immunological cross reactions. Conclusion: Results of this work emphasis existence of common antigens between hydatid cyst and cancers. Therefore, more study about these common antigens is recommende

Identification and analytical examination of copper alloy pigments applied as golden illuminations on three persian manuscripts

Golden pigments are among the most common colourants used in Persian illuminated manuscripts. In this research, golden pigments were investigated in three eighteenth- to nineteenth-century manuscripts. Initially, scanning electron microscopy-energy dispersive spectrometry analyses showed that different kinds of metallic pigments were present and some of them were ternary alloys made up of copper, zinc and tin, hence copper-based alloys were ascertained as cheap alternatives to gold. Discolouration of the pigment was observable through alteration of the metallic pigments to greenish residues in the manuscripts. Subsequently, the greenish products in the golden pigments were studied by Raman spectroscopy. Copper carboxylates were recognized as degradation products. We inferred that the alteration is a consequence of the interaction between copper alloy pigments and carboxylic acids in conditions of high humidity. Moreover, more progressive degradation has caused the discolouration, brittleness and gradually crumbling of the paper in the painted areas. Signs of damages in the paper were comparable with decomposition of the paper by green copper pigments such as verdigris in historical documents and miniatures

Molecular Docking and Thermodynamic Studies of the Interactions between Aspirinate Complexes of Transition metals and Cyclooxygenase-2 Enzyme: Quantum Chemical Calculations based on the ONIOM method

In the present research, molecular docking and thermodynamic properties of the transition metal complexes of aspirin were calculated against Cyclooxygenase-2 (COX-2) enzyme.  Density functional theory with dispersion function (DFT-D) using LANL2DZ basis set calculation was carried out to study the structural and thermodynamic properties of the interaction between aspirinate complexes of transition metals and COX-2. The ONIOM2 (wB97X-D/LANL2DZ:UFF) method was applied to the interaction of transition metal complexes with COX-2 binding site. The Interaction enthalpies and the Gibbs free energies between aspirinate complexes of Cu(II), Zn(II), Fe(III), and In(III) as anti-inflammatory complexes and COX-2  enzyme in the gas phase were calculated. The structure as well as the thermodynamics of optimized metal complexes was debated from the biological point of view. In the gas phase, the interaction was relatively strong and transition metal complexes could be used as potential anti-inflammatory drugs.</p