Physics-based prognostic modelling of filter clogging phenomena

In industry, contaminant filtration is a common process to achieve a desired level of purification, since contaminants in liquids such as fuel may lead to performance drop and rapid wear propagation. Generally, clogging of filter phenomena is the primary failure mode leading to the replacement or cleansing of filter. Cascading failures and weak performance of the system are the unfortunate outcomes due to a clogged filter. Even though filtration and clogging phenomena and their effects of several observable parameters have been studied for quite some time in the literature, progression of clogging and its use for prognostics purposes have not been addressed yet. In this work, a physics based clogging progression model is presented. The proposed model that bases on a well-known pressure drop equation is able to model three phases of the clogging phenomena, last of which has not been modelled in the literature yet. In addition, the presented model is integrated with particle filters to predict the future clogging levels and to estimate the remaining useful life of fuel filters. The presented model has been implemented on the data collected from an experimental rig in the lab environment. In the rig, pressure drop across the filter, flow rate, and filter mesh images are recorded throughout the accelerated degradation experiments. The presented physics based model has been applied to the data obtained from the rig. The remaining useful lives of the filters used in the experimental rig have been reported in the paper. The results show that the presented methodology provides significantly accurate and precise prognostic results

A Similarity-Based Prognostics Approach for Remaining Useful Life Prediction

Physics-based and data-driven models are the two major prognostic approaches in the literature with their own advantages and disadvantages. This paper presents a similarity-based data-driven prognostic methodology and efficiency analysis study on remaining useful life estimation results. A similarity-based prognostic model is modified to employ the most similar training samples for RUL estimations on each time instance. The presented model is tested on; Virkler’s fatigue crack growth dataset, a drilling process degradation dataset, and a sliding chair degradation of a turnout system dataset. Prediction performances are compared utilizing an evaluation metric. Efficiency analysis of optimization results show that the modified similarity-based model performs better than the original definition

Major challenges in prognostics: study on benchmarking prognostic datasets

Even though prognostics has been defined to be one of the most difficult tasks in Condition Based Maintenance (CBM), many studies have reported promising results in recent years. The nature of the prognostics problem is different from diagnostics with its own challenges. There exist two major approaches to prognostics: data-driven and physics-based models. This paper aims to present the major challenges in both of these approaches by examining a number of published datasets for their suitability for analysis. Data-driven methods require sufficient samples that were run until failure whereas physics-based methods need physics of failure progression

Prognostics with autoregressive moving average for railway turnouts

Turnout systems are one of the most critical systems on railway infrastructure. Diagnostics and prognostics on turnout system have ability to increase the reliability & availability and reduce the downtime of the railway infrastructure. Even though diagnostics on railway turnout systems have been reported in the literature, reported studies on prognostics in railway turnout system is very sparse. This paper presents autoregressive moving average model based prognostics on railway turnouts. The model is applied to data collected from real turnout systems. The failure progression is obtained manually using the exponential degradation model. Remaining Useful Life of ten turnout systems have been reported and results are very promising

Kırklareli-vize Çizgiselliğinin Ve Sergen Fayının Karakteri

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Avrasya Yer Bilimleri Enstitüsü , 2002Thesis (M.Sc.) -- İstanbul Technical University, Eurasia Institute of Earth Sciences , 2002Yüksek lisans tezi olarak hazırlanan bu çalışma da Trakya havzasının kuzey sınırını oluşturan bir çizgisel yapı ve bu çizgisel yapıyla aynı açıda gelişmiş olan bir fay incelenmiş ve bu iki çizgisel yapının birbirleriyle ve havza sınırıyla olan ilişkisi açıklanmaya çalışılmıştır. Bu iki yapıdan Kırklareli ilinin kuzeydoğusunda bulunan Sergen Fayı tamamen metamorfik birimlerin hakim olduğu bir arazide gelişimştir. Bu fay genişlemeyi gösteren normal karakterli bir faydır. Sergen fayının olduğu bölgede toplanan veriler ve bölgedeki ölçümler incelendiğinde bu fayda bir hareket tespit edilememiştir. Daha güneyde yeralan diğer yapı bir kaç segmentten oluşur. İncelenen en kuzeydeki bölümde Kırklareli ilinin içinden geçen bir normal fay bulunmaktadır. Fayla iligili arazi gözlemleri ve ölçümler yapılmış ve çeşitli sondaj loğları incelenmiş ve daha önceden tesbit edilememiş bu fay saptanmıştır. Yapının Pınarhisar, Vize, Binkılıç arasındaki bölümünde yüzeyde hiç bir fay saptanamamış, ancak alınmış olan sismik kesitlerin incelenmesi ile gömülü olan Kuzey Osmancık fayının Pınarhisar-Vize arasında yüzeye yaklaştığı anlaşılmıştır. Bu yapının en güneydeki kesimi İstanbul ilinin Binkılıç köyü ile Çatalca ilçesi arasındaki kesimidir. Bu kesimdeki arazi çalışmalarında Çatalca ilçesinin batısındaki sırt içerisinde Çatalca fayı olarak adlandırılmış olan fay tesbit edilmiş fayla ilgili çeşitli ölçümler alınmış ve çizgiselliğin üstündeki diğer yapılar ve Sergen fayı gibi normal bileşenli açılmayı gösteren bir yapı olduğu anlaşılmıştır. Ayrıca sırtın ve fayın morfolojik yapışma dayanarak bu sırtın kuzeydoğu yamacının hemen önünde gömülü bir fay daha bulunduğu da öne sürülmüştür. Bölgeyle ilgili yapılan ölçümler, toplanan veriler ve yapılan çalışmalar sonucunda bu yapının şu anda aktivitesini kaybetmiş, yer yer kalıntı niteliğinde hareketler gözlenen ve Trakya havzasının kuzey sınırının oluşumunda etkili olan bir transform fay ve bu faya bağlı gelişmiş bir normal fayın yüzeydeki izi olduğu anlaşılmıştır. vm In this study, which is prepared as the master thesis, a linear structure that is formed northern border of the Thrace Basin and the fault which is developed with the same angle with that linear structure is searched. The relationship of this to linear structure that is related with the each other and the border of the basin has been studied to explain. The fault Sergen which is located northeastward of city of Kırklareli has been formed in the metamorfic area. This fault is showing the normal character and extension. When we investigated the measurements and datum about this area, it hadn't been found any motion at this fault. The other structure located at more southern area contents of some segments. In most northern area of the research area, there has been a normal fault passed through Kırklareli City. An area! observations and measurements has been applied. The some drill logs have been examined. At the last of this study, a fault which hasn't been defined before that study, is found. There hasn't any fault segment in surface of the linear structure is between Pinarhisar Vize and Binkılıç. But the seismic profiles have been investigated. The buried North Osmancık fault has been approached to the surface between Pinarhisar and Vize. The most southern part of that linear structure is located between village Binkılıç and Çatalca town of İstanbul. In that area a fault which is called Çatalca fault is found at westward of Çatalca ridge has been define. Some measurements has been collected and at the end of it, a structure that is showed the normal component and extension like Sergen fault and some structures of the northern area. In addition to it, by relying on the morphological structure of the fault and ridge, that there is a buried fault which is located in front of the northeast slope of the ridge has been put forward in that study, also. In conclusion of the measurements, collected datum and studies about that area, that this structure now has been lost its activity, local motions have been observed as relic and a transform fault which is affected from formed the northern border of Thrace IXYüksek LisansM.Sc

Quantifying population-specific growth in benthic bacterial communities under low oxygen using H218O

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in ISME Journal (2019), doi:10.1038/s41396-019-0373-4.The benthos in estuarine environments often experiences periods of regularly occurring hypoxic and anoxic conditions, dramatically impacting biogeochemical cycles. How oxygen depletion affects the growth of specific uncultivated microbial populations within these diverse benthic communities, however, remains poorly understood. Here, we applied H218O quantitative stable isotope probing (qSIP) in order to quantify the growth of diverse, uncultured bacterial populations in response to low oxygen concentrations in estuarine sediments. Over the course of 7- and 28-day incubations with redox conditions spanning from hypoxia to euxinia (sulfidic), 18O labeling of bacterial populations exhibited different patterns consistent with micro-aerophilic, anaerobic, facultative anaerobic, and aerotolerant anaerobic growth. 18O-labeled populations displaying anaerobic growth had a significantly non-random phylogenetic distribution, exhibited by numerous clades currently lacking cultured representatives within the Planctomycetes, Actinobacteria, Latescibacteria, Verrucomicrobia, and Acidobacteria. Genes encoding the beta-subunit of the dissimilatory sulfate reductase (dsrB) became 18O labeled only during euxinic conditions. Sequencing of these 18O-labeled dsrB genes showed that Acidobacteria were the dominant group of growing sulfate-reducing bacteria, highlighting their importance for sulfur cycling in estuarine sediments. Our findings provide the first experimental constraints on the redox conditions underlying increased growth in several groups of “microbial dark matter”, validating hypotheses put forth by earlier metagenomic studies.This work was supported by a grant OR 417/1-1 from the Deutsche Forschungsgemeinschaft, and a Junior Researcher Fund grant from LMU Munich to WDO. This work was performed in part, through the Master’s Program in Geobiology and Paleontology (MGAP) at LMU Munich

Effect of heparin in the intraocular irrigating solution on postoperative inflammation in the pediatric cataract surgery

Yelda B Özkurt, Arzu Taskiran, Nadire Erdogan, Baran Kandemir, Ömer K Dog?anDepartment of Ophthalmology, Kartal Training and Research Hospital, Istanbul, TurkeyPurpose: To evaluate the influence of irrigation of the anterior chamber with heparin sodium on postoperative inflammation after pediatric cataract surgery. Setting: Kartal Training and Research Hospital, First Eye Clinic, Istanbul, Turkey.Design: Randomized prospective double-blind study.Methods: Fourteen consecutive eyes from 14 patients aged 8.9 ± 5.9 years, (range 3–18 years) (group 1) and 19 eyes from 19 patients aged 9.1 ± 5.2 (range 1.5–18 years) (group 2) underwent pediatric cataract surgery. Five patients in group 1 were between three and five years old. One patient was 1.5 years old and six patients in group 2 were between three and five years old. During the procedure, group 1 received anterior chamber irrigation with heparin sodium (5 IU/cc) and 1 ml of heparin sodium (concentration 10 IU/ml) added to the irrigating balanced salt solution (BSS Plus; Alcon Laboratories, Inc., Fort Worth, TX, USA) while group 2 received BSS without heparin sodium only. Cases aged under three years received anterior vitrectomy in addition to posterior capsulorrhexis. One eye received anterior vitrectomy in group 1 and two eyes received anterior vitrectomy in group 2. Cases with preoperative complications were not included in the study. Early and late postoperative inflammatory complications, including fibrin formation, anterior and posterior synechia, cyclitic and pupillary membrane formation were recorded and compared.Results: Mild anterior chamber reaction was observed in three patients in Group 1, while nine cases in group 2 experienced marked anterior chamber reaction. In four of nine patients from group 2, anterior chamber reaction was severe and resulted in pupillary membrane and synechia despite treatment in the postoperative 7th day, while in all three cases in group 1, reaction disappeared by the 7th day.Conclusion: Anterior chamber irrigation with heparin during pediatric cataract surgery may minimize early inflammatory reaction and decrease the number of postoperative inflammatory related complications.Keywords: pediatric, cataract, surgery, inflammatio

Linking Uncultivated Microbial Populations and Benthic Carbon Turnover by Using Quantitative Stable Isotope Probing

Benthic environments harbor highly diverse and complex microbial communities that control carbon fluxes, but the role of specific uncultivated microbial groups in organic matter turnover is poorly understood. In this study, quantitative DNA stable isotope probing (DNA-qSIP) was used for the first time to link uncultivated populations of bacteria and archaea to carbon turnover in lacustrine surface sediments. After 1-week incubations in the dark with [C-13]bicarbonate, DNA-qSIP showed that ammoniaoxidizing archaea (AOA) were the dominant active chemolithoautotrophs involved in the production of new organic matter. Natural C-13-labeled organic matter was then obtained by incubating sediments in the dark for 2.5 months with [C-13] bicarbonate, followed by extraction and concentration of high-molecular-weight (HMW) (> 50-kDa) organic matter. qSIP showed that the labeled organic matter was turned over within 1 week by 823 microbial populations (operational taxonomic units [OTUs]) affiliated primarily with heterotrophic Proteobacteria, Chloroflexi, Verrucomicrobia, and Bacteroidetes. However, several OTUs affiliated with the candidate microbial taxa Latescibacteria, Omnitrophica, Aminicentantes, Cloacimonates, AC1, Bathyarchaeota, and Woesearchaeota, groups known only from genomic signatures, also contributed to biomass turnover. Of these 823 labeled OTUs, 52% (primarily affiliated with Proteobacteria) also became labeled in 1-week incubations with [C-13] bicarbonate, indicating that they turned over carbon faster than OTUs that were labeled only in incubations with C-13-labeled HMW organic matter. These taxa consisted primarily of uncultivated populations within the Firmicutes, Bacteroidetes, Verrucomicrobia, and Chloroflexi, highlighting their ecological importance. Our study helps define the role of several poorly understood, uncultivated microbial groups in the turnover of benthic carbon derived from "dark" primary production. IMPORTANCE Little is known about the ecological role of uncultivated microbial populations in carbon turnover in benthic environments. To better understand this, we used quantitative stable isotope probing (qSIP) to quantify the abundance of diverse, specific groups of uncultivated bacteria and archaea involved in autotrophy and heterotrophy in a benthic lacustrine habitat. Our results provide quantitative evidence for active heterotrophic and autotrophic metabolism of several poorly understood microbial groups, thus demonstrating their relevance for carbon turnover in benthic settings. Archaeal ammonia oxidizers were significant drivers of in situ "dark" primary production supporting the growth of heterotrophic bacteria. These findings expand our understanding of the microbial populations within benthic food webs and the role of uncultivated microbes in benthic carbon turnover

Spin dynamics with non-abelian Berry gauge fields as a semiclassical constrained hamiltonian system

The dynamics of observables which are matrices depending on \hbar and taking values in classical phase space is defined retaining the terms up to the first order in \hbar of the Moyal bracket. Within this semiclassical approach a first order lagrangian involving gauge fields is studied as a constrained hamiltonian system. This provides a systematic study of spin dynamics in the presence of non-abelian Berry gauge fields. We applied the method to various types of dynamical spin systems and clarified some persisting discussions. In particular employing the Berry gauge field which generates the Thomas precession, we calculated the force exerted on an electron in the external electric and magnetic fields. Moreover, a simple semiclassical formulation of the spin Hall effect is accomplished.Comment: References and some clarification added. Published versio