Imaging spontaneous imbibition in full Darcy‐scale samples at pore‐scale resolution by fast X‐ray tomography

Spontaneous imbibition is a process occurring in a porous medium which describes wetting phase replacing nonwetting phase spontaneously due to capillary forces. This process is conventionally investigated by standardized, well-established spontaneous imbibition tests. In these tests, for instance, a rock sample is surrounded by wetting fluid. The following cumulative production of nonwetting phase versus time is used as a qualitative measure for wettability. However, these test results are difficult to interpret, because many rocks do not show a homogeneous but a mixed wettability in which the wetting preference of a rock varies from location to location. Moreover, during the test the flow regime typically changes from countercurrent to cocurrent flow and no phase pressure or pressure drop can be recorded. To help interpretation, we complement Darcy-scale production curves with X-ray imaging to describe the differences in imbibition processes between water-wet and mixed-wet systems. We found that the formation of a spontaneous imbibition front occurs only for water-wet systems; mixed-wet systems show localized imbibition events only. The asymmetry of the front depends on the occurrence of preferred production sites, which influences interpretation. Fluid layers on the outside of mixed-wet samples increase connectivity of the drained phase and the effect of buoyancy on spontaneous imbibition. The wider implication of our study is the demonstration of the capability of benchtop laboratory equipment to image a full Darcy-scale experiment while at the same time obtaining pore-scale information, resolving the natural length and time scale of the underlying processes

All Glass Enclosure with Transparently Bonded Glass Frames

This case study describes the path to an all glass enclosure that was recently built atthe Leibniz Institute for Solid State and Material Research in Dresden. The idea ofa fully transparent structure without distracting metal bolts or clamps was developedfrom the first idea to final solution in close collaboration between the client,the design team, researchers and industrial partners. Four glass frames, joined bytransparent acrylate adhesives at their edges, support the outer walls and the ceilingof the glass enclosure. Regular loading scenarios as well as different failure scenarioswere analysed to evaluate redundancy of the structural system. Comprehensivetesting was carried out, based on previous research on acrylate adhesives

The effects of a magnetic barrier and a nonmagnetic spacer in tunnel structures

The spin-polarized transport is investigated in a new type of magnetic tunnel junction which consists of two ferromagnetic electrodes separated by a magnetic barrier and a nonmagnetic metallic spacer. Based on the transfer matrix method and the nearly-free-electron-approximation the dependence of the tunnel magnetoresistance (TMR) and electron-spin polarization on the nonmagnetic layer thickness and the applied bias voltage are studied theoretically. The TMR and spin polarization show an oscillatory behavior as a function of the spacer thickness and the bias voltage. The oscillations originate from the quantum well states in the spacer, while the existence of the magnetic barrier gives rise to a strong spin polarization and high values of the TMR. Our results may be useful for the development of spin electronic devices based on coherent transport.Comment: 15 pages, 5 figure

Ultrasonic techniques to obtain dental pulp from impacted third molars

In the dental clinic impacted teeth are frequent findings, especially upper and lower third molars, leading to their exodontia. Among surgical techniques piezosurgery is advantageous for delicate structures in the oral cavity. Extracted teeth, usually di

The Complexity of Flat Freeze LTL

We consider the model-checking problem for freeze LTL on one-counter automata (OCAs). Freeze LTL extends LTL with the freeze quantifier, which allows one to store different counter values of a run in registers so that they can be compared with one another. As the model-checking problem is undecidable in general, we focus on the flat fragment of freeze LTL, in which the usage of the freeze quantifier is restricted. Recently, Lechner et al. showed that model checking for flat freeze LTL on OCAs with binary encoding of counter updates is decidable and in 2NEXPTIME. In this paper, we prove that the problem is, in fact, NEXPTIME-complete no matter whether counter updates are encoded in unary or binary. Like Lechner et al., we rely on a reduction to the reachability problem in OCAs with parameterized tests (OCAPs). The new aspect is that we simulate OCAPs by alternating two-way automata over words. This implies an exponential upper bound on the parameter values that we exploit towards an NP algorithm for reachability in OCAPs with unary updates. We obtain our main result as a corollary

ACONDICIONAMENTO E ROTULAGEM DO CHÁ DE CAPIM-LIMÃO (Cymbo-pogon citratus (D.C.) Stapf) COMERCIALIZADO PELO SEGMENTO SUPERMERCADO NA CIDADE DE CURITIBA1

Introduce informations about packaging and labelling of lemon grass , Cymbopogon citratus (D.C.) Stapf tea trademarks commercialized by supermarkets in Curitiba city. These informations were obtained between august and december of 2001, through field research, participative observation and legal documents. On totality, were identified and analysed 19 trademarks of lemon grass tea, 47,36% of them were from Paraná State. It was verified that 68,4% of trademarks were packed in secondary or terciary packages and 35,6% showed primary packages, as the package was in direct contact with food. About the labelling, the majority of trademarks analysed were suitable with the actual legislation in almost totality of considerated questions. The more frequent mistake was about the sale designation. It was registered the lack of nutritional information in two third parts of avaliated trademarks, by the time of the research. Later analyses allowed to evidence the adequation of near 56% of this trademarks about that question. Key-words: food, quality, labelling.Apresentam-se informações sobre acondicionamento e rotulagem das marcas de chá de capim- limão (Cymbopogon citratus (D.C.) Stapf), comercializadas pelo segmento supermercado na cidade de Curitiba. Tais informações foram obtidas, no período de agosto a outubro de 2001, por meio de pesquisa de campo, observação participante e documentação legal. No total, foram identificadas e analisadas 19 marcas de chá de capim-limão, sendo 47,36% de procedência paranaense. Constatou-se que 68,4% das marcas estavam acondicionadas em embalagens secundárias ou terciárias e 35,6% apresentavam-se em embalagens primárias, ou seja, a embalagem em contato direto com o alimento. Quanto à rotulagem, a maioria das marcas analisadas apresentava-se adequada à legislação vigente no que concerne à quase totalidade dos parâmetros considerados. A incorreção mais freqüente foi com relação à denominação de venda. Registrou-se ausência de rotulagem nutricional em cerca de dois terços das marcas analisadas, na época da pesquisa. Constatou-se por meio de análise comprobatória posterior, a adequação de cerca de 56% destas marcas, quanto à rotulagem correta da embalagem. Palavras-chave: alimento, qualidade, embalagem

A Microsoft-Excel-based tool for running and critically appraising network meta-analyses--an overview and application of NetMetaXL.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.BACKGROUND: The use of network meta-analysis has increased dramatically in recent years. WinBUGS, a freely available Bayesian software package, has been the most widely used software package to conduct network meta-analyses. However, the learning curve for WinBUGS can be daunting, especially for new users. Furthermore, critical appraisal of network meta-analyses conducted in WinBUGS can be challenging given its limited data manipulation capabilities and the fact that generation of graphical output from network meta-analyses often relies on different software packages than the analyses themselves. METHODS: We developed a freely available Microsoft-Excel-based tool called NetMetaXL, programmed in Visual Basic for Applications, which provides an interface for conducting a Bayesian network meta-analysis using WinBUGS from within Microsoft Excel. . This tool allows the user to easily prepare and enter data, set model assumptions, and run the network meta-analysis, with results being automatically displayed in an Excel spreadsheet. It also contains macros that use NetMetaXL's interface to generate evidence network diagrams, forest plots, league tables of pairwise comparisons, probability plots (rankograms), and inconsistency plots within Microsoft Excel. All figures generated are publication quality, thereby increasing the efficiency of knowledge transfer and manuscript preparation. RESULTS: We demonstrate the application of NetMetaXL using data from a network meta-analysis published previously which compares combined resynchronization and implantable defibrillator therapy in left ventricular dysfunction. We replicate results from the previous publication while demonstrating result summaries generated by the software. CONCLUSIONS: Use of the freely available NetMetaXL successfully demonstrated its ability to make running network meta-analyses more accessible to novice WinBUGS users by allowing analyses to be conducted entirely within Microsoft Excel. NetMetaXL also allows for more efficient and transparent critical appraisal of network meta-analyses, enhanced standardization of reporting, and integration with health economic evaluations which are frequently Excel-based.CC is a recipient of a Vanier Canada Graduate Scholarship from the Canadian Institutes of Health Research (funding reference number—CGV 121171) and is a trainee on the Canadian Institutes of Health Research Drug Safety and Effectiveness Network team grant (funding reference number—116573). BH is funded by a New Investigator award from the Canadian Institutes of Health Research and the Drug Safety and Effectiveness Network. This research was partly supported by funding from CADTH as part of a project to develop Excel-based tools to support the conduct of health technology assessments. This research was also supported by Cornerstone Research Group

Reconstrucción funcional buco-maxilofacial: nuevas perspectivas

Dado que diversas funciones vitales dependen del área buco-maxilofacial, la misma posee un rol central en el organismo humano y, si eventualmente sufre alteraciones por lesiones o patologías, plantea un gran desafío restituir su integridad en los pacientes. Desde la ingeniería tisular se han propuesto terapias de regeneración o reemplazo de tejidos u órganos para devolver la morfología y la funcionalidad a las estructuras afectadas. Las células madre han adquirido relevancia creciente debido a que sustentan muchos de estos enfoques terapéuticos. El potencial de aplicación clínica de las células madre en el complejo orofacial sería fundamental para la regeneración de tejidos que devuelva el bienestar a los pacientes A fin de reparar el área comprometida se pueden emplear variedad de materiales y técnicas quirúrgicas reconstructivas. Es factible recurrir a dispositivos protésicos personalizados según la lesión o el daño que presenta cada paciente, lo cual implica el desarrollo de protocolos para el abordaje integral de cada caso, desde su etapa de diseño, respetando los parámetros anatómicos, hasta su colocación y seguimiento.En la práctica clínica odontológica la implementación de estas nuevas perspectivas de abordaje terapéutico impactaría en la atención de los pacientes, repercutiendo positivamente en el estado de salud oral de la población

Screening of brazilian plants for the presence of peroxides

Extratos clorofórmicos ou diclorometânicos de 357 espécies vegetais de ocorrência no sul do Brasil foram testados quanto à presença de peróxidos, através de cromatografia em camada delgada, utilizando o reagente de detecção de Huber & Fröhlke. Das espécies testadas, 71 (20%) apresentaram resultado positivo, a maioria delas (56%) pertencentes à família Asteraceae. A maioria das espécies testadas pertencia a Asteraceae, mas outras 55 famílias foram também testadas, abrangendo um total de 77 gêneros.Chloroform or dichloromethane extracts of 357 southern Brazilian plant species were tested for the presence of peroxides by thinlayer chromatography, using the spray reagent from Huber & Fröhlke. From the species tested, 71 (20%) showed positive results and most of them (56%) are Asteraceae species. The species tested were mainly from Asteraceae, but 55 more families were screened, in a total of 77 genera surveyed