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Mikroalglerden katı katalizörler üzerinde biyoyakıt ve biyokimyasal üretimi
No full textThesis (Doctoral)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2020Includes bibliographical references (leaves: 68-76)Text in English; Abstract: Turkish and EnglishThe target of this study was the investigation of biofuel and/or biochemical production from microalgae in growth medium or its lipids over heterogenous catalyst. The primary aim was to study the conversion of 6 wt. % N. Oculata into biofuels without harvesting and dewatering over Ni-Al2O3-SiO2 catalyst at 80oC and 1 atm for 24 h. Solgel method was used to synthesize the catalyst by using the acids of H2SO4, HCl, and HNO3 to investigate the effect of acid type on catalytic activity. The catalyst prepared with H2SO4 yielded the highest conversion. The treatment of the catalyst prepared by H2SO4, with NaCl increased the conversion from 74 % to 91.5 % under same reaction conditions. The products included poly- or monosaccharides, esters and fatty acids. To achieve this conversion, Ni presence was significant beside total acidity of 25 μmol per gram of catalyst, and acidic strength ranging between 130-380oC. A new industrial application was proposed for direct conversion of 6 wt. % N. Oculata into biofuels at 80oC and 1 atm. The capacity of the plant was 1669 liters biofuel per year from 1064 liters microalgae solution per hour. The catalyst prepared with H2SO4 was used to coat either inner surface of tubes or 1-meter pluggable monoliths in tubular reactor having 20 m length and 1000 tubes each of which had 4 cm diameter. The microalgae solution was heated with Therminol®66 heated via parabolic troughs. For operation continuity, ~46000 kg of oil was stored in the tank at 120 o C for 12 h. The production of ethyl ester biodiesel from Spirulina sp. and N. Oculata lipids over 60 % CaO/Al2O3 was studied at 50oC and 1 atm. Ethanol: lipid molar ratio, catalyst amount and reaction time were investigated parameters to identify their effects on catalytic activity. The study showed that ~59 % biodiesel yield was obtained in the presence of the catalyst which was 6 wt. % of lipids, in 30 min. at ethanol: lipid molar ratio of 12 while 90 %-99 % yield was acquired at ethanol: lipid molar ratios of 24 and 48. To achieve these yields, weak basic strength in the form of bicarbonate was necessary while high basicity was not essential. Pure alumina and CaO did not yield any lipid conversion. Glycerolysis of triacylglycerol took place in series with reverse transesterification of triacylglycerol at catalyst amount which was 6 wt. % of lipids, ethanol: lipid molar ratio of 24 and 48, and 60 min. reaction time.Bu çalışmanın amacı mikroalglerden katı katalizörler üzerinde biyoyakıt ve biyokimyasalların elde edilmesidir. Yapılan çalışmada mikroalglerin biyoyakıta dönüştürülmesi üç ayrı kısımda incelenmiştir. İlk bölümde büyüme ortamında kütlece 6% olan N.Oculata mikroalginin hasatlama ve kurutma olmadan katı katalizör üzerinde direkt biyoyakıt ve biyokimyasallara dönüştürülmesi 80oC ve 1 atm çalışma koşullarında ve 24 saat reaksiyon süresinde gerçekleştirilmiştir. Bu amaçla katalizörlerin asitlik ve asit bölgelerinin kuvvetlerinin reaksiyon üzerindeki etkilerini incelemek amacıyla sol-jel yöntemi kullanılarak farklı asitler (H2SO4, HCl ve HNO3) ile alümina-silika destekli nikel katalizörleri sentezlenmiştir. Yapılan reaksiyon çalışmaları sonucunda en yüksek mikroalg dönüşümü sülfürik asit ile sentezlenen katalizör üzerinde elde edilmiştir. Ayrıca bu katalizör NaCl ile muamele edilmiş ve elde edilen katalizör kullanılarak aynı koşullarda gerçekleştirilen reaksiyonların sonucunda mikroalg dönüşümünün %74 'den %91,5'e yükseldiği gözlemlenmiştir. Reaksiyon sonucunda elde edilen ürün dağılımının içerisinde yağ asidi, polisakkarit, monosakkarit ve esterlerin olduğu görülmüştür. Yüksek mikroalg dönüşümünün elde edilmesi için nikel varlığının yanı sıra toplam katalizör asitliğinin gram katalizör başına 25 μmol olması ve asitlik kuvvetinin 130-380 oC arasında olması gerektiği bulunmuştur. Bunun yanı sıra, büyüme ortamındaki N.Oculata mikroalginin hasatlama ve kurutma olmadan direkt olarak biyoyakıtlara çevrilmesinin endüstriyel uygulanma yöntemi ile ilgili bir öneri sunulmuştur. Bu önerinin temelinde reaktörde bulunan tüplerin veya monolitlerin sentezlenen katalizörler ile kaplanması prensibi yatmaktadır. Bir diğer yapılan çalışmada ise Spirulina sp. ve N.Oculata mikroalg lipitlerinden 60 % CaO/Al2O3 katalizörü üzerinde etil ester biyodizel üretimi gerçekleştirilmiştir. Yapılan çalışmalarda 12 etanol: lipit oranında ve lipidin kütlece 6%'sı kadar katalizör miktarında, %59 biyodizel verimi 30 dakikalık reaksiyon sonucunda elde edilirken 90- 99% biyodizel verimi 24 ve 48 etanol: lipit oranlarında elde edilmiştir. Yüksek verimleri elde edebilmek için katalizör üzerinde bikarbonat fazında düşük bazik kuvvetinin olması gerektiği bulunmuştur. Ayrıca saf alümina ve ticari kalsiyum oksit katalizörleri üzerinde herhangi bir lipit dönüşümü elde edilmemiştir
Using Inorganic Nanoparticle-Based Drug Delivery Systems against Human Colon Cancer Cells: Effect of Particle Size on Anticancer Activity
No full textToday's nanoparticle technology enables the synthesis of nanoparticle-based drug delivery systems with desired size, shape, and materials especially for the applications of cancer nanomedicine. Thereby, understanding impact of particle sizes on anticancer activity will contribute to development of new drug delivery systems in cancer therapy. For this reason, in this study, two different sized nanoparticles (with -55 and 314 nm) were used as drug delivery systems and the effects of their size on the cellular uptake, cytotoxicity and apoptosis were investigated against the human colon carcinoma Caco-2 and HCT-116 cells. The results demonstrated that small nanoparticles promoted fast nanoparticle accumulation in both cancer cells in comparison to large particles. Small nanoparticles exhibited higher cytotoxicity in cancer cells with lower half maximal inhibitory concentration (IC50) values than large nanoparticles in 48 h. On the other hand, both nanoparticles showed similar IC50 values after 72 h prolonged exposure. Moreover, it was found that small nanoparticles increased the number of apoptotic cells in 24 h, whereas large nanoparticles induced apoptosis when exposure time increased to 72 h. These observations show that small sized drug delivery systems could be more efficient for improving the anticancer effects of chemotherapeutic drugs against human colon carcinoma as compared to large sized drug delivery systems
Fast pyrolysis with fractional condensation of lignin-rich digested stillage from second-generation bioethanol production
No full textYildiz, Guray/0000-0001-7399-0605; Heeres, Hero Jan/0000-0002-1249-543XPoplar-derived lignin-rich feedstock (i.e. stillage) obtained from bioethanol production was subjected to fast pyrolysis in a modified fluidised bed reactor at 430 degrees C, 480 degrees C, and 530 degrees C. The stillage was pretreated by enzymatic digestion prior to fast pyrolysis. Pyrolysis vapors were collected by fractional condensation to separate the heavy organic and aqueous phase liquids. The intention of this study was to assess the potential utilization of lignin-rich digested stillage as a fast pyrolysis feedstock. Heavy organic and aqueous phase pyrolysis liquids were obtained in yields ranging from 15.1-18.1 wt.% and 9.7-13.4 wt.% respectively. The rest of the feedstock material was converted to char (37.1-44.7 wt.%) and non-condensable gases (27.1-31.5 wt.%). Detailed liquid analysis indicated that the heavy organic phase fractions contain compounds arising from the degradation of lignin, residual microbial biomass and remaining polysaccharides. Fast pyrolysis adds 26.8 wt.% to the conversion of this otherwise recalcitrant feedstock material, thereby reducing waste generation and enhancing the value of second-generation bioethanol production
Performance of the reconstruction and identification of high-momentum muons in proton-proton collisions at √s=13 TeV
No full textThe CMS detector at the LHC has recorded events from proton-proton collisions, with muon momenta reaching up to 1.8 TeV in the collected dimuon samples. These high-momentum muons allow direct access to new regimes in physics beyond the standard model. Because the physics and reconstruction of these muons are different from those of their lower-momentum counterparts, this paper presents for the first time dedicated studies of efficiencies, momentum assignment, resolution, scale, and showering of very high momentum muons produced at the LHC. These studies are performed using the 2016 and 2017 data sets of proton-proton collisions at root s = 13 TeV with integrated luminosities of 36.3 and 42.1 fb(-1), respectively
Review-Supercritical deposition: A powerful technique for synthesis of functional materials for electrochemical energy conversion and storage
No full textWOS:000520534400001Supercritical fluid-based technologies are increasingly being used to develop novel functional nanostructured materials or improve the properties of existing ones. Among these, supercritical deposition (SCD) is an emerging technique to incorporate metals on supports. It has been used to deposit a wide variety of single or multi-metallic morphologies such as highly dispersed species, nanoparticles, nanorods and conformal films on high surface area supports, polymers and crystalline substrates. SCD is also attracting increasing attention for preparation of micro or nano-architectured functional materials in a highly controllable manner for electrochemical energy conversion and storage systems. Increasing number of studies in the literature demonstrates that materials synthesized using SCD are comparable or superior in performance as compared to their conventional counterparts. In this review, an overview of the fundamentals of the SCD technique is presented. Properties of a wide variety of nanostructured functional materials such as supported nanoparticles and films prepared using SCD for electrochemical applications are summarized. The electrochemical performance of these materials in electrochemical tests and also in fuel cells, electrolyzers and Li-ion batteries are also presented. (C) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited
Irrigation of world agricultural lands: Evolution through the Millennia
No full textMany agricultural production areas worldwide are characterized by high variability of water supply conditions, or simply lack of water, creating a dependence on irrigation since Neolithic times. The aim of this paper is to provide an overview of the evolution of irrigation of agricultural lands worldwide, based on bibliographical research focusing on ancient water management techniques and ingenious irrigation practices and their associated land management practices. In ancient Egypt, regular flooding by the Nile River meant that early agriculture probably consisted of planting seeds in soils that had been recently covered and fertilized with floodwater and silt deposits. On the other hand, in arid and semi-arid regions farmers made use of perennial springs and seasonal runoff under circumstances altogether different from the river civilizations of Mesopotamia, Egypt, India, and early dynasties in China. We review irrigation practices in all major irrigation regions through the centuries. Emphasis is given to the Bronze Age civilizations (Minoans, Egyptians, and Indus valley), pre-Columbian, civilizations from the historic times (e.g., Chinese, Hellenic, and Roman), late-Columbians (e.g., Aztecs and Incas) and Byzantines, as well as to Ottomans and Arabs. The implications and impacts of irrigation techniques on modern management of water resources, as well as on irrigated agriculture, are also considered and discussed. Finally, some current major agricultural water management challenges are outlined, concluding that ancient practices could be adapted to cope with present challenges in irrigated agriculture for increasing productivity and sustainability. © 2020 by the authors
Effect of urban transformation on the values of historic sites around mosques: Two cases in Manisa, Turkey
No full textThis study presents a framework for assessing the cultural asset values of historic sites around mosques. Case studies are selected from provinces of Manisa, Turkey, namely, Çarşı in Salihli with its new urban development and Pazaryeri in Gördes that is abandoned and currently considered as an archaeological site. Literature review, archive research, historical research, comparative study, and site survey are carried out to evaluate the urban development of site neighborhoods with a retrospective perspective. An approach presenting the effects of urban transformations on the cultural asset values of the historic neighborhood centers is proposed. The cases reveal that the urban aesthetic is nearly all lost today, but the holiness of each site preserves its authenticity while the historic land use is sustained. Their preservation problems are lack of maintenance and abandonment due to disasters, illegal interventions, inappropriate development plans, and unsuitable restoration approaches. The principles proposed for managing these historic environments consider their cultural asset values in relation to urban history, development of coherent strategies for their presentation, and participation of all actors to their preservation and development. © 2020 The Author
Implementation of a mobile platform based on Fiber Bragg Grating sensors for automotive traffic monitoring
No full textPubMed: 32168970Instrumentation techniques, implementation and installation methods are major concerns in today's distributed and quasi-distributed monitoring applications using fiber optic sensors. Although many successful traffic monitoring experiments have been reported using Fiber Bragg Gratings (FBGs), there has been no standardized solution proposed so far to have FBG seamlessly implemented in roads. In this work, we investigate a mobile platform including FBG sensors that can be positioned on roads for the purpose of vehicle speed measurements. The experimental results prove the efficiency of the proposed platform, providing a perspective toward weigh-in-motion systems
Search for supersymmetry with a compressed mass spectrum in events with a soft τ lepton, a highly energetic jet, and large missing transverse momentum in proton-proton collisions at √s=13 TeV
No full textPubMed: 32058742The first search for supersymmetry in events with an experimental signature of one soft, hadronically decaying tau lepton, one energetic jet from initial-state radiation, and large transverse momentum imbalance is presented. These event signatures are consistent with direct or indirect production of scalar tau leptons ((tau) over tilde) in supersymmetric models that exhibit coannihilation between the (tau) over tilde and the lightest neutralino ((chi) over tilde (0)(1)), and that could generate the observed relic density of dark matter. The data correspond to an integrated luminosity of 77.2 fb(-1) of proton-proton collisions at root s = 13 TeV collected with the CMS detector at the LHC in 2016 and 2017. The results are interpreted in a supersymmetric scenario with a small mass difference (Delta m) between the chargino ((chi) over tilde (+/-)(1)) or next-to-lightest neutralino ((chi) over tilde (0)(2)), and the (chi) over tilde (0)(1). The mass of the (tau) over tilde is assumed to be the average of the (chi) over tilde (1)(+/-) and (chi) over tilde (0)(1) masses. The data are consistent with standard model background predictions. Upper limits at 95% confidence level are set on the sum of the (chi) over tilde (+/-)(1). (chi) over tilde (0)(2), and (tau) over tilde production cross sections for Delta m ((chi) over tilde (+/-)(1),(chi) over tilde (0)(1)) = 50 GeV, resulting in a lower limit of 290 GeVon the mass of the (chi) over tilde (+/-)(1), which is the most stringent to date and surpasses the bounds from the LEP experiments
Search for high mass dijet resonances with a new background prediction method in proton-proton collisions at √s = 13 TeV
No full textA search for narrow and broad resonances with masses greater than 1.8 TeV decaying to a pair of jets is presented. The search uses proton-proton collision data at s = 13 TeV collected at the LHC, corresponding to an integrated luminosity of 137 fb?1. The background arising from standard model processes is predicted with the fit method used in previous publications and with a new method. The dijet invariant mass spectrum is well described by both data-driven methods, and no significant evidence for the production of new particles is observed. Model independent upper limits are reported on the production cross sections of narrow resonances, and broad resonances with widths up to 55% of the resonance mass. Limits are presented on the masses of narrow resonances from various models: string resonances, scalar diquarks, axigluons, colorons, excited quarks, color-octet scalars, W? and Z? bosons, Randall-Sundrum gravitons, and dark matter mediators. The limits on narrow resonances are improved by 200 to 800 GeV relative to those reported in previous CMS dijet resonance searches. The limits on dark matter mediators are presented as a function of the resonance mass and width, and on the associated coupling strength as a function of the mediator mass. These limits exclude at 95% confidence level a dark matter mediator with a mass of 1.8 TeV and width 1% of its mass or higher, up to one with a mass of 4.8 TeV and a width 45% of its mass or higher. [Figure not available: see fulltext.] © 2020, The Author(s)