Treatment of high salinity waste water from shale gas exploitation by forward osmosis processes

© 2015 by the American Society of Civil Engineers. All Rights Reserved. This chapter reviews state-of-the-art treatment of shale-gas-produced water with a focus on the treatment of shale-gas flow-back water (SGW) by forward osmosis (FO). It briefly introduces the origin and chemical/physical characteristics of SGW. Management of shale-gas wastewater depends on multidimensional criteria, e.g., local regulations, site conditions, water quality, and economic feasibility. Approaches used to treat high-salinity wastewater include deep well injection, transport and centralized treatment, treatment and disposal, and reuse. The chapter analyzes the advantages and limitations of potential treatments methods and summarizes the process parameters and selection of membrane and draw solutions. Studies were performed to examine the effectiveness of FO in treating high-salinity wastewater produced from shale-gas exploitation. The chapter discusses the potential for using the FO process to treat SGW on a large scale

Finite-temperature Gutzwiller projection for strongly correlated electron systems

We generalized the Gutzwiller projectional variational method for the ground state of strongly correlated electron systems to the case of finite temperature. Under the Gutzwiller approximation, we show that this maps to a finite temperature renormalized mean-field theory. As one of the key ingredients in the theory, we obtained an explicit expression of the projection entropy or the entropy change due to the projection. We illustrate the application of the theory to the Anderson impurity problem and the half-filled Hubbard model and compare the theory to more elaborate techniques. We find qualitative agreement. The theory can be applied to a wide variety of Hubbard, t-J, and Anderson impurity models. © 2010 The American Physical Society.published_or_final_versio

Open porous hydrophilic supported thin-film composite forward osmosis membrane via co-casting for treatment of high-salinity wastewater

© 2016 High-performance thin film composite (TFC) forward osmosis (FO) membranes with a low degree of internal concentration polarization (ICP) are critical for concentrating high-salinity wastewaters. This report focuses on the preparation of TFC FO membranes via a sacrificial approach. In order to improve the FO flux, hydrophilicity and morphology of the support membrane were mainly investigated. The hydrophilicity of the polysulfone (PSF) substrate was tuned by blending with sulfonated poly (ether ether ketone) (SPEEK), and the resulting SPEEK blended PSF membrane was denoted as SPSF substrate. The pore structure of the SPSF membrane was tailored by the application of a co-casting technique, which yielded a TFC membrane with a structure parameter (S) of 191 μm. In contrast, the TFC membranes based on the PSF and SPSF substrates through single layer casting showed S values of 527 μm and 361 μm, respectively. These results indicate that the combined hydrophilicity and open pore structure are responsible for the lowered S value. Further application of the hydrophilic substrate based TFC membranes in the treatment of high salinity wastewaters (10 wt%) demonstrated the higher initial water flux (28.3 L/m2·h) with a water recovery rate of 53.2% in comparison to the TFC membrane based on the pristine PSF through the single layer casting. This new method paves a way to generate high-performing FO membranes

Achiral phenolic N-oxides as additives: an alternative strategy for asymmetric cyanosilylation of ketones

The activation of chiral titanium(IV) complexes with additives, phenolic N-oxides, is found to provide an alternative strategy for asymmetric cyanosilylation of ketones in excellent yield With LIP to 82%, ee. (C) 2004 Elsevier Ltd. All rights reserved

Concentrating underground brine by FO process: Influence of membrane types and spacer on membrane scaling

© 2015 Elsevier B.V. Forward osmosis (FO) is a low energy process when recovery of the draw solutes is not necessary. This study focused on the performance of the FO process for concentrating underground brine (UGB) with saturated sodium chloride as draw solution (DS) using two membranes: commercialized flat sheet cellulose triacetate (CTA) membrane and tailor-made thin film composite (TFC) FO membrane. Energy dispersive X-ray spectroscopy (EDS) and powder X-ray diffractometry (XRD) analysis indicate that, majority of the scaling components were calcium sulfate and sodium chloride crystals formed both through surface and bulk crystallization. The spacer in the FO test cell also promoted scaling. Without spacer, a sharp flux decline of TFC membrane occurred at a higher concentration factor while no sharp flux drop was observed for CTA membrane. It was hypothesized that the rough TFC membrane surface may initiate nucleation and aggregation of the crystals in the active surface, and eventually resulting in scaling

Graphene oxide incorporated polysulfone substrate for the fabrication of flat-sheet thin-film composite forward osmosis membranes

© 2015 Elsevier B.V. The preparation and performances of the newly synthesized thin film composite (TFC) forward osmosis (FO) membranes with graphene oxide (GO)-modified support layer are presented in this study. GO nanosheets were incorporated in the polysulfone (PSf) to obtain PSf/GO composite membrane support layer. Polyamide (PA) active layer was subsequently formed on the PSf/GO by interfacial polymerization to obtain the TFC-FO membranes. Results reveal that at an optimal amount of GO addition (0.25wt%), a PSf/GO composite support layer with favorable structural property measured in terms of thickness, porosity and pore size can be achieved. The optimum incorporation of GO in the PSF support layer not only significantly improved water permeability but also allowed effective PA layer formation, in comparison to that of pure PSf support layer which had much lower water permeability. Thus, a TFC-FO membrane with high water flux (19.77Lm-2h-1 against 6.08Lm-2h-1 for pure PSf) and reverse flux selectivity (5.75Lg-1 against 3.36Lg-1 for pure PSf) was obtained under the active layer facing the feed solution or AL-FS membrane orientation. Besides the improved structural properties (reduced structural parameter, S) of the support layer, enhanced support hydrophilicity also contributed to the improved water permeability of the membrane. Beyond a certain point of GO addition (≥0.5wt%), the poor dispersion of GO in dope solution and significant structure change resulted in lower water permeation and weaker mechanical properties in support as well as FO flux/selectivity of consequent TFC membrane. Overall, this study suggests that GO modification of membrane supports could be a promising technique to improve the performances of TFC-FO membranes

General disease resistance loci against biotrophic pathogens in wheat

Dissertação de Mestrado Integrado em Arquitectura, apresentada ao Departamento de Arquitectura da Faculdade de Ciências e Tecnologia da Universidade de Coimbra, sob a orientação do Prof. Doutor Walter Rossa.Um ano depois de a UNESCO inscrever a “Universidade de Coimbra - Alta e Sofia” na lista do Património Mundial da Humanidade e face ao desafio académico de Coimbra Capital Europeia da Cultura em 2027, este trabalho tem como objectivo analisar e perceber como se alterou a imagem urbana da cidade e de que maneira o branding que proponho para a mesma vai clarificar essa imagem, de forma a criar uma linguagem coerente e clara, que traga valor para Coimbra. O trabalho divide-se em quatro partes. A primeira exibe a importância do branding para as cidades, entendendo que este conceito é fundamental para que Coimbra construa uma visão de futuro, com uma melhoria no espaço público e com uma linguagem coerente entre a Universidade a tudo o que a dinamiza. A segunda parte, analisa a evolução da imagem e do sistema urbano do espaço que escolhi como exemplo de trabalho, a antiga Quinta de Santa Cruz, onde foi criado o “boulevard” da cidade, a Avenida Sá da Bandeira e a Praça da República. Na terceira parte, vou analisar criticamente estes dois espaços de maneira a perceber como alterar a imagem suja que a cidade tem hoje, clarificando-a e sabendo que esta zona tem tudo para ser o verdadeiro centro cosmopolita de Coimbra. Por último, associo a esse exemplo um de outra natureza, mas com ele coerente no compto geral do processo, a criação de um logótipo que vai qualificar a cidade e que vai estar presente na mudança do sistema urbano, ajudando a clarificar a imagem da cidade.One year later that UNESCO aggregated “Universidade de Coimbra - Alta e Sofia” at the list of World Heritage Site and the academic challenge of Coimbra European Capital of Culture in 2027, this work aims to analyze and understand how changed the image of urban city , and that way, how the branding that i’ll propose for the city, will clarify this image in order to create a coherent and clear language that bring value to Coimbra. The work is divided into four parts. A first that displays the importance of branding for cities, and how these concept is fundamental to Coimbra build a vision of future, with an improvement in public space and with identical language between the University and everything that surrounds it. The second part examines the evolution of the urban system and the image of the space that i found as an example to work, the old Quinta de Santa Cruz, where the “boulevard” of the city with the Avenue Sá da Bandeira and Republic Square was created. In the third part i will analyze and criticize these two spaces so that you can understand how to clean the soiled image that the city transpires today, in order to make clear that this space has everything to be the true cosmopolitan center of Coimbra. Finally i will associate this example to other of a diferent nature, but coherent in the overall process, the creation of a logo that will qualify the city and that will be present in the changing of urban system helping to clarify the city’s image

Dehydration of forward osmosis membranes in treating high salinity wastewaters: Performance and implications

© 2015 Elsevier B.V. Forward osmosis (FO) is a promising technique for desalinating high salinity wastewaters, and membrane performance is critical for its successful application. In this work, the dehydration of FO membranes was demonstrated for both commercial cellulose triacetate and tailor-made thin-film composite membranes. A significant loss of FO flux was observed after membrane dehydration, but the pure water permeability and rejection properties remained about the same. Dehydrated membrane showed opaque/white spots on the initially homogeneous membrane. Once dehydrated, a membrane with a much lower water flux will be resulting in. It was demonstrated that when the active skin layer was in contact with the saline solution before the support layer was brought into contact with an aqueous solution, membrane dehydration took place. The dehydration was ascribed to osmosis gradient across the active layer that caused water flow from membrane support layer to the active layer, resulting in support dehydration. The dehydrated membrane could be rewetted again by low surface tension liquid or reverse osmosis, illustrating that membrane dehydration is reversible. Precaution should be addressed when operating large FO system to prevent the membrane dehydration for high salinity water treatment

Malondialdehyde level and some enzymatic activities in subclinical mastitis milk

The purpose of this study was to evaluate the changes occurring in milk malondialdehyde (MDA) level and some enzymatic activities as a result of subclinical mastitis (SCM) in dairy cows. A total of 124 milk samples were collected from 124 lactating cows from the same herd in the period between the 2nd week after calving and the 10th week postpartum. They were classified by bacterial culture and the California mastitis test (CMT) as positive were deemed to have glands with SCM, and the periodic incidence rate of SCM was 26.6%. The most common bacterial isolates from SCM cases were Staphylococcus aureus (47%) and coagulase negative Staphylococci (CNS) (27%). The mean level of MDA and activities of lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) were significantly higher in SCM milk than in normal milk, while the mean activity of glutathione peroxidase (GPx) was significantly lower in SCM milk than in normal milk. There were no differences in the activities of superoxide dismutase (SOD) and aspartate aminotransferase (AST) between normal milk and SCM milk. Therefore, the measurement of milk MDA level and GPx, LDH and ALP activities, appears to be a suitable diagnostic method for identifying SCM in dairy cows.Key words: Subclinical mastitis, mastitis diagnostic, etiology, malonaldehyde (MDA), enzym