Performance Evaluation of Hollow Fiber Membrane for Carbon Dioxide Separation: An Experimental Approach

This report outlines the background of the project "Perfonnance Evaluation of Hollow Fiber Membrane for Carbon Dioxide Separation: An Experimental Approach". Due to the fact that carbon dioxide ( C02) is present in all natural gas sources worldwide, there is much attention placed on the efficiency in separating C02 from natural gas. Recent developments have discovered the benefits of utilizing membrane for this purpose. The scope of this study is on the performance of hollow fiber in removing carbon dioxide with respect to the variations in pressure, composition, feed gas flow and membrane area or better represented as number of hollow fibers used in a membrane module. The procedures are conducted in the Research Centre for Carbon Dioxide Capture (RCC02C) with the Carbon Dioxide Separation Membrane Unit (COzSMU). The perfonnance is evaluated based on experimental approach and the results are to be analyzed and discussed with reference to previous works as well as separation theories and principles. In the first chapter, a general introduction is given on the separation techniques available in the current market which is followed by the problem statement on the drawbacks of the conventional separation techniques, of which supports the use of membrane for C02 capture. Next, the objectives and the scope of this study are defined. In the following chapter, literature review is conducted to find out on membrane separation technology including general principles, key characteristics of membrane, its classifications, separation theories and principles, as well as the benefits of membrane for separation processes. In Chapter 3, the general approach on the conduct of this study is illustrated, which generally summarizes the scope of work for this project. Also, the experimental procedures are illustrated in a detailed manner to ensure that the steps are that required to obtain satisfacatory results. Besides, all the chemicals required are also listed while each the equipments in the setup are defined for its function and purpose. Next, reports on the findings of the experiments are illustrated. The experimental parameters conducted in the study includes pressure, feed composition, feed gas flow as well as membrane area. It was found that the stage cut and the selectivity of the membrane increases with pressure and feed composition while these two parameters shows a decrease when the feed gas flow rate is increased. Generally, the number of fibers used does not affect the selectivity of the membrane but the stage cut of the membrane is largely increased when the number of fibers used is increased. In terms of permeance, it was found that the gas permeance increases with increasing feed composition, feed gas flow rate as well as number of fibers or membrane area but decreases with increasing feed pressure. Last but not least, the conclusion of this report summarizes the document as a whole together with the obtained results of this experimental work, in terms of the focus of this study, which is the effect of pressure, feed gas flow, COz composition, and unmber of fibers in a module on the performance of the hollow fiber membrane

Performance Evaluation of Hollow Fiber Membrane for Carbon Dioxide Separation: An Experimental Approach

This report outlines the background of the project "Perfonnance Evaluation of Hollow Fiber Membrane for Carbon Dioxide Separation: An Experimental Approach". Due to the fact that carbon dioxide ( C02) is present in all natural gas sources worldwide, there is much attention placed on the efficiency in separating C02 from natural gas. Recent developments have discovered the benefits of utilizing membrane for this purpose. The scope of this study is on the performance of hollow fiber in removing carbon dioxide with respect to the variations in pressure, composition, feed gas flow and membrane area or better represented as number of hollow fibers used in a membrane module. The procedures are conducted in the Research Centre for Carbon Dioxide Capture (RCC02C) with the Carbon Dioxide Separation Membrane Unit (COzSMU). The perfonnance is evaluated based on experimental approach and the results are to be analyzed and discussed with reference to previous works as well as separation theories and principles. In the first chapter, a general introduction is given on the separation techniques available in the current market which is followed by the problem statement on the drawbacks of the conventional separation techniques, of which supports the use of membrane for C02 capture. Next, the objectives and the scope of this study are defined. In the following chapter, literature review is conducted to find out on membrane separation technology including general principles, key characteristics of membrane, its classifications, separation theories and principles, as well as the benefits of membrane for separation processes. In Chapter 3, the general approach on the conduct of this study is illustrated, which generally summarizes the scope of work for this project. Also, the experimental procedures are illustrated in a detailed manner to ensure that the steps are that required to obtain satisfacatory results. Besides, all the chemicals required are also listed while each the equipments in the setup are defined for its function and purpose. Next, reports on the findings of the experiments are illustrated. The experimental parameters conducted in the study includes pressure, feed composition, feed gas flow as well as membrane area. It was found that the stage cut and the selectivity of the membrane increases with pressure and feed composition while these two parameters shows a decrease when the feed gas flow rate is increased. Generally, the number of fibers used does not affect the selectivity of the membrane but the stage cut of the membrane is largely increased when the number of fibers used is increased. In terms of permeance, it was found that the gas permeance increases with increasing feed composition, feed gas flow rate as well as number of fibers or membrane area but decreases with increasing feed pressure. Last but not least, the conclusion of this report summarizes the document as a whole together with the obtained results of this experimental work, in terms of the focus of this study, which is the effect of pressure, feed gas flow, COz composition, and unmber of fibers in a module on the performance of the hollow fiber membrane

Widespread GLI expression but limited canonical hedgehog signaling restricted to the ductular reaction in human chronic liver disease

Canonical Hedgehog (Hh) signaling in vertebrate cells occurs following Smoothened activation/translocation into the primary cilia (Pc), followed by a GLI transcriptional response. Nonetheless, GLI activation can occur independently of the canonical Hh pathway. Using a murine model of liver injury, we previously identified the importance of canonical Hh signaling within the Pc+ liver progenitor cell (LPC) population and noted that SMO-independent, GLI-mediated signals were important in multiple Pc-ve GLI2+ intrahepatic populations. This study extends these observations to human liver tissue, and analyses the effect of GLI inhibition on LPC viability/gene expression. Human donor and cirrhotic liver tissue specimens were evaluated for SHH, GLI2 and Pc expression using immunofluorescence and qRT-PCR. Changes to viability and gene expression in LPCs in vitro were assessed following GLI inhibition. Identification of Pc (as a marker of canonical Hh signaling) in human cirrhosis was predominantly confined to the ductular reaction and LPCs. In contrast, GLI2 was expressed in multiple cell populations including Pc-ve endothelium, hepatocytes, and leukocytes. HSCs/myofibroblasts (gt;99%) expressed GLI2, with only 1.92% displaying Pc. In vitro GLI signals maintained proliferation/viability within LPCs and GLI inhibition affected the expression of genes related to stemness, hepatocyte/biliary differentiation and Hh/Wnt signaling. At least two mechanisms of GLI signaling (Pc/SMOdependent and Pc/SMO-independent) mediate chronic liver disease pathogenesis. This may have significant ramifications for the choice of Hh inhibitor (anti-SMO or anti-GLI) suitable for clinical trials. We also postulate GLI delivers a pro-survival signal to LPCs whilst maintaining stemness

Elevated p62/SQSTM1 determines the fate of autophagy-deficient neural stem cells by increasing superoxide

Autophagy plays important roles in many biological processes, but our understanding of the mechanisms regulating stem cells by autophagy is limited. Interpretations of earlier studies of autophagy using knockouts of single genes are confounded by accumulating evidence for other functions of many autophagy genes. Here, we show that, in contrast to Fip200 deletion, inhibition of autophagy by deletion of Atg5, Atg16L1, or Atg7 does not impair the maintenance and differentiation of postnatal neural stem cells (NSCs). Only Fip200 deletion, but not Atg5, Atg16L1, or Atg7 deletion, caused p62/sequestome1 aggregates to accumulate in NSCs. Fip200 and p62 double conditional knockout mice demonstrated that p62 aggregate formation triggers aberrant superoxide increases by impairing superoxide dismutase functions. By comparing the inhibition of autophagy by deletion of Atg5, Atg16L1, or Atg7 with Fip200 deletion, we revealed a critical role of increased p62 in determining the fate of autophagy-deficient NSCs through intracellular superoxide control

Mesenchymal stromal cell engagement in cancer cell epithelial to mesenchymal transition

Due to coexistence of stromal and epithelial tumor cells, their dynamic interactions have been widely recognized as significant cellular components to the tumor tissue integrity. Initiation and outcome of epithelial to mesenchymal transition (EMT) in tumor cells are dependent on their interaction with adjacent or recruited mesenchymal stromal cells (MSCs). A plethora of mechanisms are involved in MSCs-controlled employment of the developmental processes of EMT that contribute to loss of epithelial cell phenotype and acquisition of stemness, invasiveness and chemoresistance of tumor cells. Interplay of MSCs with tumor cells, including interchange of soluble biomolecules, plasma membrane structures, cytoplasmic content, and organelles, is established through cell-cell contact and/or by means of paracrine signaling. The main focus of this review is to summarize knowledge about involvement of MSCs in cancer cell EMT. Understanding the underlying cellular and molecular mechanism involved in the interplay between MSCs and cancer EMT is essential for development of effective therapy approaches, which in combination with current treatments may improve the control of tumor progression. Developmental Dynamics 247:359-367, 2018

Cre-ativity in the liver:Transgenic approaches to targeting hepatic nonparenchymal cells

Rapid evolution in transgenic (Tg) mouse technology now permits cell-specific and temporal control of fluorescent cell-labeling and gene inactivation. Here, we discuss the principal strategies that have been utilized to target, label, and manipulate hepatic nonparenchymal cells, with emphasis on the utility of constitutive and inducible Cre-lox systems. We summarize key findings of studies employing Tg technology to target hepatic stellate cells, myofibroblasts, liver sinusoidal endothelial cells, and macrophages to illustrate the power of these approaches in identifying cell-specific molecular mechanisms critical to the pathophysiology of liver disease. Increasing adoption of Tg techniques will help to answer fundamental questions regarding the pathogenesis of hepatic diseases and provide the mechanistic rationale to allow identification of novel drug targets, ultimately translating into effective therapies for patients with liver disease. (Hepatology 2015;61:2091–2099

Modifikasi Pencerna Anaerobic

Research on renewable energy process is carried out nowadays. The renewable energies include solar energy, wind energy, biomass energy and nuclear energy. Biomass sources estimated about 1800 billion tonnes[Biomass Handbook, Osamu Kitani & Carl 1989] is an efficient altenative energy. It has been used by human for a long time ago. Biomass is an organic matter consists of domestic waste, industrial waste and etc. biomass can be converted into fuel for generating electricity, heat and etc. Anaerobic digestion is a process to produce methane gas from biomass. Anaerobic digestion is process of bacteria digestion in the absence of oxygen. This method becomes popular in Malaysia since there are a lot of biomass sources like rubish, kitchen waste, animals waste and etc. This method can produce high quality of biogas contain about 55-65% of methane and it can be widely used for cooking, operating engine and etc. The main objective of this project is to modified the existing anaerobik digester to increase biogas production. The existing digester can produce up to 48.5% of methane. Modifications include biogas recirculation of biogas, heating the digester slurry and to make mixing process more efficient. Biogas storing tank has to be prepared for biogas storing

Mechanism of n-butane Isomerization over Superacidic Sulfated Metal Oxides

[[abstract]]Superacidic sulfated metal oxides were prepared by impregnating different metal oxides (or hydroxides) with sulfuric acids. The superacidic strength of prepared samples were compared by temperature-programmed desorption of ammonia (NH3-TPD) and showed a trend of HS/ZrO2>HS/MgAl2O4>HS/Al2O3>HS/Fe2O3. Catalytic properties of these superacidic samples towards isomerization of n-butane to isobutane were subsequently pursued. Both the activity and the isobutane selectivity increased with the superacidic strength of catalysts. Observed variation in the selectivity was interpreted with a difference in the reaction mechanism: A high selectivity was obtained from strong superacid sites that catalyze the isomerization through a revised monomolecular mechanism; while a low selectivity became dominated on weak superacid sites that favored a bimolecular mechanism. The relative importance of these two mechanisms was kinetically controlled by formation of different butyl carbenium ions (primary or secondary) while the n-butane reactant adsorbed on superacidic sites