Utility of PCA and Other Data Transformation Techniques in Exoplanet Research

This paper focuses on the utility of various data transformation techniques, which might be under the principal component analysis (PCA) category, on exoplanet research. The first section introduces the methodological background of PCA and related techniques. The second section reviews the studies which utilized these techniques in the exoplanet research field and compiles the focuses in the literature under different items in the overview, with future research direction recommendations at the end.Comment: 15 page

Catalytic fast pyrolysis of biomass

Utilization of biomass offers a potential to sustain the current petro-chemical economy for the production of chemicals and (transportation) fuels on basis of renewable resources. Crude bio-oil derived from fast pyrolysis of lignocellulosic biomass is a mixture of water (15-30 wt.%) and various oxygen containing organic compounds. The presence of oxygen in bio-oils (ca. 35–40 wt.%) is commonly believed to be the origin of problems caused by its high water content (15–30 %), corrosiveness (pH of 2–3), relatively low heating value compared to fossil fuels (ca. 17 MJ/kg), poor volatility, and high viscosity (35–1000 cP at 40 °C). However, not only the level of oxygen in the bio-oil is too high, but also the way it exists (functionality) is a part of the problem. Improving the quality of the bio-oils, whether or not in combination with a certain degree of oxygen removal, would include a selective transformation of certain oxygen functionalities such as acids and aldehydes into ‘desired’ or acceptable ones like alcohols, phenols, and ethers. Application of heterogeneous catalysis in fast pyrolysis (i.e. catalytic fast pyrolysis; CFP) may lead to a liquid product (i.e. catalytic fast pyrolysis oil, CFP-oil) with an improved quality compared to that of crude bio-oil. Here, the improvement in bio-oil quality refers to the production of either high yields of transportation fuel compounds (e.g. aromatics, olefins) and specialty chemicals (e.g. phenolics), or just a drop-in refinery feedstock to be blended with the feed streams of existing petroleum refineries. While the literature on catalytic fast pyrolysis of biomass -mainly focussed on catalyst screening- is rapidly expanding, there is an urgent need for the translation of laboratory results to viable process concepts and bench/pilot plant trials. Together with the development of efficient catalysts, the design and the intensification of the process with efficient heat integration are of significant importance in the catalytic conversion of lignocellulosic biomass to the targeted liquid product. The present thesis discusses the catalytic fast pyrolysis of lignocellulosic biomass in a process oriented way that may initiate a useful process technology development in the near future. The final goal is to come up with recommendations and suggestions on how to realize this technique at a commercial/industrial scale. That requires a better understanding of the precise effects of the essential process parameters (e.g. processing mode; in- or ex situ) and design elements (e.g. reactor type, catalyst type) on the one hand, and definitions and outcomes of possible obstacles (e.g. successive regeneration of the catalyst, effect of biomass ash) on the other. In this work, two types of continuously operated (catalytic) fast pyrolysis reactors were used, viz. an auger reactor and a mechanically stirred bed reactor. In all experiments performed in both setups, pine wood with a particle size range of 1 to 2 mm was pyrolyzed at a constant reactor temperature of 500 °C. In the auger reactor, first the effect of the operation mode on the product yields and compositions has been investigated while using a single type of heterogeneous ZSM-5 based acidic catalyst. Two operation modes were tested. In situ operation includes the mixing of biomass and catalyst inside a single reactor, while ex situ refers to catalytic treatment of the pyrolysis vapours in a secondary reactor. A second study was concerned with the screening of various heterogeneous catalysts (and their metal doped counterparts) in in situ operation. In all experiments, the presence of catalysts led to the production of additional water, coke and gases at the expense of the liquid organics and char. The overall performance of in situ catalysis in terms of oil quality was considerably better than that of ex situ catalysis; more aromatics and phenols were produced in the case of in situ operation. That may be caused by different vapour residence times and vapour-catalyst contact times. Among all eight catalysts tested, the acidic catalyst containing some redox active metal, the basic catalyst with a mixture of two metal oxides (calcined), and a metal oxide doped gamma-alumina catalyst (calcined) were found to be the best performing ones, based on both the deoxygenation requirements and the production of desirable compounds in high yields. In the mechanically stirred bed reactor, we studied i) the effect of a repeated catalyst regeneration (eight cycles in total), and ii) the effects of the pine wood ash on the yields and composition of the products. In all catalytic experiments, a single type of a ZSM-5 based catalyst was used in situ. Along the reaction/regeneration cycles, trends in pyrolysis product yields converging to that of non-catalytic levels were observed. This revealed that the activity, and thus the influence of the catalyst slowly declined, which was confirmed by a BET surface area reduction of 63 %. Ash concentrations as low as ca. 3 wt.% relative to the amount of pine wood fed, and ca. 0.002 wt.% relative to the amount of bed material, were found sufficient to affect the yield and composition of the CFP products unfavourably. Finally, the technical and operational barriers for the implementation of catalytic fast pyrolysis technology are discussed while focusing on the process modes and parameters, economical use of the primary and secondary products, and heat integration. Some process alternatives for an efficient CFP operation are suggested as well. Research has, until now, been focused mainly on screening and small-scale testing of various catalysts. One challenge in developing CFP of biomass is the design and large scale production of such catalysts to enable testing in continuously operated, bench and pilot scale installations. FCC type of catalysts are the only suitable ones commercially available. But they are developed especially for use in a riser reactor and short contact times (differing significantly from typical biomass devolatilization times). The main problem in CFP of biomass was found to be the presence of the biomass originated alkaline ash which eventually poisons any catalyst in case of direct contact. In a commercial process, a solution may be to separate the biomass fast pyrolysis from the catalytic treatment of the vapours (i.e. ex situ processing mode) where the physical contact between the biomass minerals and the catalyst is excluded. Even though this requires significant process adjustments, ex-situ processing allows the catalyst to be re-used in a much larger number of reaction/regeneration cycles than in case of in situ operation

Partial purification and characterization of polyhenol oxidase from thermophilic Bacillus sp.

Thesis (Master)--Izmir Institute of Technology, Biotechnology, Izmir, 2009Includes bibliographical references (leaves: 41-47)Text in English; Abstract: Turkish and Englishx, 54 leavesPolyphenol oxidases are enzymes that catalyze the oxidation of phenolic compounds using molecular oxygen. The ability of polyphenol oxidases to act on phenolic compounds makes them highly useful biocatalysts for various biotechnological applications. They are commonly found in animals, plants and fungi. Recent genome analysis have shown that polyphenol oxidases are also widespread in bacterial species. In this study, detection, partial purification and characterization of polyphenol oxidase from thermophilic Bacillus sp., which was isolated from a geothermal region was achieved. The samples from bacterial culture were boiled and compared with not boiled ones in order to prove the existence of enzyme in bacterium. The existence was also supported with the appearance of dark bands on polyacrylamide gel after staining with catechol solution. Results of activity staining and activity measurements of samples from intracellular and extracellular extract revealed that the enzyme was intracellular. Partial purification was performed by acetone precipitation and gel filtration chromatography with 35% yield and 1.24 purification fold. Characterization studies indicated that the enzyme showed highest activity at pH 7.0 and 60C, was stable at temperatures between 30 and 60C and more than 80% of activity was retained in the pH range of 5-8. The results of agent and metal ion effect on enzyme activity revealed that the enzyme was totally inhibited in the presence of DTT and sodium diethyldithiocarbamate and highly activated with copper ions whereas other agents or metal ions did not have significant effect on activity. Km and Vmax values for the enzyme were determined as 91mM and 2.25 .abs/min/ml, respectively

Recognition of dynamic objects from UGVs using Interconnected Neuralnetwork-based Computer Vision system

In this study, moving object recognition is performed by using images from a camera mounted on an unmanned ground vehicle. A GPS coordinate-based algorithm has been developed to obtain moving object silhouettes. In order to classify these silhouettes, an interconnected artificial neural network (ICANN) architecture consisting of two stages has been developed. The method consists of two phases. In the first phase, real-time images are converted to binary images at the end of the GPS-assisted image registration process. Then, the silhouettes are extracted from the background of the images using connected component labelling. In the second phase, two interconnected neural networks are used. The first neural network classifies silhouettes as objects or noise. The second neural network divides objects into seven subclasses as pedestrians, potholes, cars, etc. Compared to CNN-based techniques, a simpler NN architecture was employed in the research, and better accuracy rates were achieved with fewer samples. Another contribution of the research is simultaneous localization and mapping (SLAM) applications can be performed in non-GPS environments using pre-recorded images containing GPS information. In experimental studies, maximum success rates of 96,1% in object classification were obtained. The results obtained were compared to YOLO, the recently popular algorithm for object recognition

QCD Sum Rules study of meson-baryon sigma terms

The pion-baryon sigma terms and the strange-quark condensates of the octet and the decuplet baryons are calculated by employing the method of quantum chromodynamics (QCD) sum rules. We evaluate the vacuum-to-vacuum transition matrix elements of two baryon interpolating fields in an external isoscalar-scalar field and use a Monte Carlo-based approach to systematically analyze the sum rules and the uncertainties in the results. We extract the ratios of the sigma terms, which have rather high accuracy and minimal dependence on QCD parameters. We discuss the sources of uncertainties and comment on possible strangeness content of the nucleon and the Delta.Comment: 17 pages, 10 figures, to be published in Phys. Rev.

Catalytic fast pyrolysis of biomass: from lab-scale research to industrial applications

In recent years, catalytic fast pyrolysis (CFP) of biomass as a means of producing bio-oil with improved physico-chemical properties, has received a lot of attention. This technique, either by adding catalyst particles to the pyrolysis reactor (in situ) or by ex situ vapour treatment, is meant for removal of the oxygen and cracking of the high molecular weight compounds in the primary pyrolysis vapours. So far, various projects have tried/are trying to push catalytic fast pyrolysis to the pilot scale, or even to the commercial scale, but have met varying levels of success. This work therefore tries to answer various research questions that would improve the future strategies related to this technology. These contain the optimal properties of a catalyst for CFP, the consequences of long-term usage of catalysis, and the presence of biomass originated ash in large scale CFP systems. The objective of this research is to investigate possible beneficial effects on the bio-oil quality, of various catalysts applied inside the pyrolysis reactor or in the vapour-product stream, in relationship with the applied process conditions. The catalysts (in total eight proprietary catalysts) were tested in two dedicated lab-scale reactors (with intakes of 500 g/h and 200 g/h) that allow variation of the catalyst loading and contact times while producing larger samples in continuous operation. The effects of successive catalyst regeneration and the presence of biomass ash in catalytic fast pyrolysis of pine wood were investigated, as well. The results consist of a combined summary of three individual research studies, which were extensively studied in a PhD project: i) Screening metal doped catalysts in situ for continuous catalytic fast pyrolysis of pine wood, ii) Catalytic fast pyrolysis of pine wood: Effect of successive catalyst regeneration, and iii) Effect of biomass ash in catalytic fast pyrolysis of pine wood. Some technical recommendations for an ideal, industrial-scale CFP process and our view regarding the future direction of the topic will be included as well

Surgical principles in posterior transpedicular screw fixation and fusion for treatment of spondylolisthesis: Retrospective evaluation of 77 cases

Aim: This study aimed to report our surgical principles and outcomes in patients who had posterior transpedicular screw fixation and fusion operation with a diagnosis of spondylolisthesis at our department between 2014 and 2017. Method: Seventy-seven patients who had internal fixation and posterolateral fusion operation using lumbar posterior transpedicular screw systems were retrospectively evaluated. All patients were assessed by dynamic lumbar graphics, computerized tomography and magnetic resonance imaging prior to surgery. Posterior decompression, internal fixation with posterior interpeduncular screw, and posterolateral fusion were applied to all patients. Stabilization systems were evaluated by lumbar graphics and computerized tomography at the postoperative first day. Results: All patients who had clinical and radiological evidences of lumbar spinal instability also had lumbar and/or leg pain and varying levels of neurological deficits. Mean age of the patients was 52.6 (19-74) years, of whom 10 were male and 67 were females. Sixty-nine patients had grade I, and 8 patients had grade II spondylolisthesis according to the Meyerding classification. Nine patients were operated for L3-4, 36 were operated for L4-5, 30 were operated for L5-S1 spondylolisthesis, and 2 patients had 2 levels of spondylolisthesis. Complaints were decreased postoperatively in all patients. One patient was reoperated due to a screw on L5, which was out of the pedicle and caused symptoms. Another 3 patients were reoperated due to breaking of a unilateral S1 screw. Conclusion: Internal fixation with posterior transpedicular screw and posterolateral fusion applications should be preferred for surgical treatment of patients who have symptomatic and neurologic-deficit causing lumbar spondylolisthesis

Weight–strength optimization of wooden household chairs based on member section size

Weight-strength optimization of wooden household chairs was performed based on the member section size in this study. Member section sizes of the Scotch pine (Pinus sylvestris) and Oriental beech (Fagus orientalis) chairs were optimized and resulting re-manufactured optimized chairs were tested under the cyclic “front to back”, “back to front” and “backrest” loads according to American Library Association (ALA) specification. Finite element method (FEM) and MATLAB nonlinear programming were utilized for the optimization. Firstly, the internal forces and moments acting on each member were analyzed by FEM in order to obtain the maximum critical stresses in each type of member; then, optimized cross-sectional sizes of the members were determined by Gradient Descent method, and all constraints were treated with Logarithmic Barrier Functioning. As a result, the minimum section sizes of members were determined, and cyclic performance tests were performed to determine whether the optimized chairs were strong enough to carry the acceptable loads. According to the results, member section size of both beech and pine chairs could be significantly reduced. The reduction was 32 % in the total weight and volume for beech chairs while 16 % for pine chairs without sacrificing the performance required for domestic usage by ALA. In conclusion, the method used is suitable for the optimization of furniture frames, making it lighter and reducing the material costs.&nbsp

Transfusion in Transplantation

Hematopoietic stem cell transplantation is increasingly performed in several diseases; majority of them are hematologic malignancies. Hematopoietic stem cell transplantation is not an instant procedure; contrarily, its unique clinical and laboratorial consequences may take life‐long time. Blood product transfusion is an inevitable and critical component for the management. Hematopoietic stem cell transplant patients have different requirements regarding blood products transfusion because of their immune status, long‐term cytopenias and especially HLA and ABO incompatibilities. Health‐care staff who take a part in the management of those patients should be aware of specific and specialized transfusion requirements