81 research outputs found
Quantitative seismic attribute analysis using artificial neural networks and seismic stratigraphic interpretation of lower to middle Miocene sediments offshore New Jersey
No full textThis study comprises two parts intended to improve understanding of the lower and middle Miocene depositional history of the New Jersey continental shelf. The first, lower Miocene-based part, aims to determine lateral variations in lithofacies between holes drilled by IODP Expedition 313 using seismic attributes and artificial neural networks. The second provides detailed seismic sequence stratigraphy of mid-Miocene successions. Neural networks are used in the first part to search for a relationship between seismic attributes and gamma log measurements of the lower Miocene section. Using this relationship, the networks generate 'pseudo gamma logs' that predict lateral changes in lithofacies based on accompanying changes in seismic attributes. A successful test of the technique is demonstrated using 3D seismic data and 6 closely-spaced gamma raylogs from the Denver Basin. A similar application to lower Miocene successions offshore NJ is unsuccessful, most likely due to an insufficient number of wells, complexity of lithofacies variations between wells up to 12 km apart, and/or an incorrect selection of attributes. In the second part, candidate sequence boundaries are identified in a grid of high- resolution, densely spaced profiles. In addition to a more detailed history than derived from prior studies, this part reveals previously unreported records of sediment erosion and possible global climate influence on the middle Miocene stratigraphic evolution offshore New Jersey. Eleven candidate sequence boundaries, three not documented by previous studies, are identified. System tract positions of each sequence are determined, while only one transgressive system tract and no lowstand fans are observed. Age estimates based on published studies show that the 11 mid Miocene sequences reported here span the interval between ~11.8-12.9 Ma, suggesting an average interval between each of 100 kyr. Clinoform rollovers prograded SE during the development of the oldest sequence of the study area beginning at a time that coincides with a major shift in !18O towards heavier values (represented by Mi4) and at about the time of the permanent East Antarctic ice sheet development. Grain size distribution of the prograding clinoforms is predicted by extrapolating IODP Expedition 313’s lithostratigraphic analysis of lower Miocene succession.M.S.Includes bibliographical referencesby Sarp Karakay
Selim İleri’nin Yarın Yapayalnız Romanında Farklı Bir Başkarakter: Handan Sarp
No full textSelim İleri is an important author distinguished with his novels stories, senarioes and the studies in Turkish Literature. In his lost novel, Yarın Yapayalnız, he has introduced a different character to us. This novel has dealt with a love, between oparate artist Handan Sarp and Elem, who is dress-maker. İleri has given us this love from many different aspects.</p
Principle and theoretical background of pressure-retarded osmosis process
No full textPressure-retarded osmosis (PRO) uses a semipermeable membrane to control the osmotic mixing to generate renewable osmotic power from a salinity gradient. The main goal of a PRO system is to economically provide an appropriate amount of green energy. Furthermore, one of the key factors for a successful PRO system is the selection of a suitable draw solution that possesses a greater osmotic pressure than that of the feed solute to drag water through the membrane. Therefore quantifying the osmotic pressure and the extractable mixing energy is required. In this chapter, we discuss the general principles of PRO, before addressing modeling of the osmotic pressure associated with the osmotic power generation
Bio-inspired fabrication of adsorptive ultrafiltration membrane for water purification: Simultaneous removal of natural organic matters, lead ion and organic dyes
No full textConventional ultrafiltration membrane is difficult to achieve the multi-component removal of water contaminants including macromolecules and small ions. Meanwhile, a large number of petrochemical-based polymers as membrane material is raising concerns about environmental risk. In this study, we present a feasible way for the manufacture of multifunctional cellulose-based nanocomposite membranes via bio-fabrication by Acetobacter xylinus for water purification. The harvested bacterial cellulose (BC) pellicle was coated by polydopamine (PDA) as a functional layer and molecular linker to immobilize carboxylated cellulose nanocrystals (C-CNCs) to prepare BC/PDA14h/CNCs membrane (BCM/PDA14h/CNCs). The composited PDA and C-CNCs on the BC nanofibers endowed the membrane with a maximum adsorption capacity of up to 167.80 mg g−1 for Pb2+, and 251.58 mg g−1 for methylene blue (MB). Multiple contaminants (heavy metals, organic dyes, and natural organic matter (NOM)) can also be treated by BCM/PDA14h/CNCs simultaneously during the dynamic filtration process. The removal efficiency of BCM/PDA14h/CNCs against the mixture of metal ions is inversely proportional to the radius of hydrated ions. The selective separation studies on binary dye mixtures showed that the separation efficiency of the membrane is mainly related to the electronegativity of dyes. The BCM/PDA14h/CNCs exhibited preferential adsorption for cationic dyes, with a separation efficiency was up to 98%. Dynamic fouling experiments confirmed that the BCM/PDA14h/CNCs presented excellent antifouling performance and showed a high flux recovery ratio. The multifunctional characteristic, high removal efficiency, excellent reusability and stability as well as environmentally friendly feature of the prepared membrane in the present study provide a sustainable approach for membrane fabrication and promising application in water purification
An overview of oil–water separation using gas flotation systems
No full textOil concentration levels in municipal waste water effluent streams are stringently regulated in most parts of the world. Apart from municipal waste, stricter oil/grease discharge limits are also enforced in oil and gas sectors as large volumes of produced water is being discharged to open ocean. One of the feasible, practical and established methods to remove oil substances from waste water sources is by gas flotation. In this overview, gas flotation technologies, namely dissolved and induced flotation systems, are discussed. Physico-chemical interaction between oil–water-gas during flotation is also summarized. In addition to a brief review on design advancements in flotation systems, enhancement of flotation efficiency by using pre-treatment methods, particularly coagulation-flocculation, is also presented
Emerging forward osmosis and membrane distillation for liquid food concentration: A review
No full textAs emerging membrane technologies, forward osmosis (FO) and membrane distillation (MD), which work with novel driving forces, show great potential for liquid food concentration, owing to their low fouling propensity and great driving force. In the last decades, they have attracted the attention of food industry scientists in global scope. However, discussions of the FO and MD in liquid food concentration advancement, membrane fouling, and economic assessment have been scant. This review aims to provide an up‐to‐date knowledge about liquid food concentration by FO and MD. First, we introduce the principle and applications of FO and MD in liquid food concentration, and highlight the effect of process on liquid food composition, membrane fouling mechanism, and strategies for fouling mitigation. Besides, economic assessment of FO and MD processes is reviewed. Moreover, the challenges as well as future prospects of FO and MD applied in liquid food concentration are proposed and discussed. Comparing with conventional membrane‐based or thermal‐based technologies, FO and MD show outstanding advantages in high concentration rate, good concentrate quality, low fouling propensity, and low cost. Future efforts for liquid food concentration by FO and MD include (1) development of novel FO draw solution (DS); (2) understanding the effects of liquid food complex compositions on membrane fouling in FO and MD concentration process; and (3) fabrication of novel membranes and innovation of membrane module and process configuration for liquid food processing
Direct and Indirect Seawater Desalination by Forward Osmosis
No full textForward osmosis (FO) is an emerging membrane technology with a range of possible water treatment applications including desalination. The FO process itself can directly desalt seawater as a feed solution by employing a draw solution with higher osmotic pressure than seawater. However, the energetics of product water recovery and draw solution reuse is not favorable. Alternatively, the FO process using seawater as a natural draw solution and quality-impaired water as the feed can potentially couple with low-pressure reverse osmosis as a hybrid to be a lower-energy desalination process, in which indirect desalination is achieved. Most organic fouling in FO desalination process is reversible. However, the mechanism of scaling formation in FO desalination is more complicated than the conventional RO process. Both feed and draw solution can influence the scaling formation and its reversibility. The economic feasibility of FO desalination process depends on the operational mode (direct and indirect) as well as the plant scale and level of commercialization. Although there are still some choke points in the current deployment of FO desalination, the future development of efficient draw solution and novel FO membrane will significantly promote FO desalination technology
Pressure Retarded Osmosis (PRO): Past experiences, current developments, and future prospects
No full textPressure Retarded Osmosis (PRO) has attracted worldwide attention with respect to its salinity gradient energy production potential, and low energy desalination applications. PRO processes, which use Seawater Reverse Osmosis (SWRO) brine as draw solutions, have a higher potential of being applied to any new, and existing membrane based seawater desalination systems, as an energy production and/or conservation process. Hydraulic pressure is applied on a high salinity draw solution, and the hydraulic pressure of the high salinity draw solution can be kept relatively constant during operation, even though the volumetric flow rate is to be increased. Therefore, the draw side of the PRO process can be considered near-isobaric, in most cases. The harvested Gibbs free energy of mixing, and the volumetric expansion can explain this near-isobaric behavior of the draw side in the PRO process. Thus, PRO can be used to multiply the internal energy of the draw solution with respect to the ratio of the permeated water flux. Even though PRO has very high theoretical potential for energy production and/or recovery, there are several shortcomings, which should be answered before the realization of the scale up applications, such as; thermodynamic process optimization, high power density membranes, and high efficiency hydraulic pressure conversion and recovery systems. This review gives detailed information about the PRO process including; (1) theoretical background, (2) membranes for PRO, (3) experimental and large scale applications, and (4) economic feasibility of PRO applications
Nanofiltration and ultrafiltration of endocrine-disrupting compounds
No full textEndocrine disrupting compounds (EDCs) have been considered emerging pollutants and have been found in various water sources around the world. Two of the main issues in removing EDCs from water sources are the size and the functionality (functional groups, charge, etc.) of the EDCs, which makes them harder to remove with loose membrane processes and low oxidation potential oxidants. Specialized ultrafiltration (UF) and tight nanofiltrations (NF) could offer a more economical and less energy dependent solution to EDCCs removals from water sources. In this chapter we have looked at the current developments in UF and NF membranes and how they could be used to remove EDCs
How about nano? Impact of size of plastics on plastic pollution and the magnitude of the problem
Get PDFIn the last decade we have realized that the plastics we use every day, and for practically everything, may be the biggest environmental polluters humans have ever released to the environment (EU DG, 2011). Since the first reports of plastic pollutions, we have learned so much about the issue. Macro and micro plastic pollution topics have been extensively studied, investigated, regulated, and in some cases litigated (Uren Webster et al., 2020)(Barnes, Galgani, Thompson, Barlaz, 2009)(Environment Agency, 2018). As it happened in most of the past cases, we have started with the most obvious and visible problem: macro plastics
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