Medium Filter Research Articles

Filtering of Electronic Speckle Correlation Fringes

Speckle correlation fringes include a large quantity of speckle noise. It is first to consider how to reduce speckle noise before using phase formula to calculate. Filter is usually used to reduce speckle noise. From two aspects of frequency domain and space domain, we adopted mean filter, medium filter, Butterworth low-pass filter and homomorphism filter to process the speckle correlation fringes obtained by experiment. It is shown that the speckle correlation fringes are clearer and more easily interpreted and automatic processed after being filtered.

Two stage filtration for stormwater treatment: a pilot scale study

Abstract This paper presents the results of the granular medium filter and membrane (Ultra Flo membrane) filter experiments conducted with raw stormwater collected from a stormwater canal at Carlton, in Sydney. The filter medium experimented were granular activated carbon (GAC), anthracite and sand. Each was used as a single medium in a 1 m filter column. The filter columns were operated atfiltration velocity 10 m h–1. The GAC filter column was capable of significantly reducing the influent dissolved organic carbon (DOC) concentrations. After GAC filtration of stormwater, the average concentration of DOC was 1.76 mg l–1, measured using LC-OCD, which represents a 70% removal of all types of organic. Membrane filtration removed a small additional amount of organics. The GAC filter as a pre-treatment to membrane filtration performed effectively with significant removals in most heavy metals although their influent concentrations were low. The treatment train of GAC filter column followed by membrane filtrati...

환경시료에 존재하는 미생물 배양을 위한 filter plate micro trap의 개발

난배양성 미생물의 배양과 보다 다양한 미생물의 분리를 위하여 Filter plate microbial trap (FPMT)을 개발하였고, 이 장치를 사용하여 Greenland의 토양에서 세균을 분리하였다. FPMT는 배지와 하단부의 membrane filter(0.45 <TEX>${\mu}m$</TEX> pore size)로 구성되어 있다. 시료에 포함된 세균과 화학물질이 FPMT 내로 이동하고, 세균이 증식하는 원리이다. 그 결과, FPMT를 이용한 새로운 in situ 배양방법을 통해 통상적인 Petri dish 배양방법보다 더 많은 종과 기존의 방법으로는 배양할 수 없는 세균을 분리하였다. 이 장치는 앞으로 다양한 환경에서 난배양성 미생물을 분리하는데 유용함을 확인하였다. Filter plate microbial trap (FPMT) was invented as an in situ cultivation device for the isolation of bacteria from natural environments. FPMT consists of a medium and membrane filters (0.45 <TEX>${\mu}m$</TEX> pore size) and microorganisms and compounds can be moved freely moved into the medium. This device was applied to two soil samples of Greenland. The microbial diversity of both soil samples by FPMT was higher than that by the conventional Petri dish-based method. Moreover, novel bacterial species were isolated by FPMT. The new FPMT is effective for in situ cultivation of natural samples and could be applicable to the isolation of uncultivable microorganism.

Capturing significant events with neural networks

Smartphone video capture and transmission to the Web contributes to data pollution. In contrast, mammalian eyes sense all, capture only significant events, allowing us vividly recall the causalities. Likewise in our videos, we wish to skip redundancies and keep only significantly differences, as determined by real-time local medium filters. We construct a Picture Index (PI) of one's (center of gravity changes) among zeros (no changes) as Motion Organized Sparseness (MOS). Only non-overlapping time-ordered PI pair is admitted in the outer-product Associative Memory (AM). Another outer product between PI and its image builds Hetero-AM (HAM) for fault tolerant retrievals.

Crystal Grain Morphology Evolution over Ti, V, Nb and Ta Surface Heated in N&lt;sub&gt;2&lt;/sub&gt; Gas Environment to 2000&amp;deg;C by Filtered Concentrated Solar Beam in a Solar Furnace at PROMES-CNRS

In recent attempts of reacting d-group transition metals with N2 gas under irradiation of concentrated solar beam at temperatures around 2000°C using a standard setup with graphite specimen holder, reaction products obtained were carbo-nitrides rather than targeted nitrides on account of yield of C2 radical plume from the graphite crucible. To suppress the interference of C2 radical possessing high carbon chemical activity a(C) in nitriding d-group transition elements in solar furnace, we investigated effectiveness of inserting colour filters in the solar beam path. Two readily available colour filters, Sky blue and Medium yellow filters, were tested for this purpose. As reported in our earlier publications, XRD (X-ray diffraction) phase identification results indicated that insertion of the Sky blue filter was effective for suppressing C2 radical yield under solar beam radiation to synthesize carbo-nitride with comparatively high N content. On the other hand, insertion of the Medium yellow filter did not result in so remarkable effect for suppressing carburization as the one detected with the Sky blue filter. In the present work, aspects of microstructures developed for Ti, V, Nb and Ta surfaces heated to 2000°C under exposure to colour-filtered solar beam in N2 gas environment are reviewed. The present experimental evidences indicated that, by insertion of the Sky blue filter, appreciable crystallite grain size refinement was realized for the synthesized M(C,N) with high N content while, by insertion of the Medium yellow filter, certain extent of influence on the morphological development, that varied depending on the substrate material, was unmistakably discernible. [doi:10.2320/matertrans.M2011299]

Biofiltration of Nitrous Oxide Using Cow-Manure Based Compost as Medium Filter

Nitrous oxide (N2O) gas is a fourth contributor in the greenhouse effect after CO2, CH4, and water vapor. Although its concentration is relatively low, but very difficult to be decomposed in the atmosphere. A laboratory-scale biofilter was used to evaluate the effects of flow rate, medium depth, and water content of filter medium on the N2O removal efficiency and the growth of microorganisms in the compost. The biofilter was operated using cow-manure based compost medium with husk and coco peat as bulking agent. Research was carried out by batch flow system for 9 hours. The result indicates that the highest N2O removal efficiency is obtained under flow rate of 88 cm3/min with a depth of 50 cm and water content 50% (w/w) by 61%, and elimination capacity for 14078 g/(m3·h) was achieved.

Biotemplate synthesis of porous titanium oxide fiber and study on its photocatalytic performance

Medium speed filter paper is applied as biotemplates to synthesize biogenic-TiO2. Through one step infiltration process in titanium-chloride-ethanol solution, followed by washing with ethanol, white sheets was obtained after calcination. Unique bio-morphic film-anatase-titania with diameter of ca. 1-3 μm were synthesized and characterized by Field Emission Scanning Electron Microscope (FESEM), High Resolution Transmission Electron Microscopy (HRTEM), X-ray Diffraction Spectroscopy (XRD) and so forth. The results showed that the products were composed 2-6 nm piled pores stacked by polycrystalline nanoparticles with sizes about 10 nm which arranged on the surface of biomorphic titania. The specific area of the sample was 71 m2/g. While the concentration of helianthine solution is 20 mg/L, catalyst amount 0.1 g/L, the reaction had a higher decoloring rate following irradiation with a UV light source, the decoloring rate can reach over 100% after 150 min.

Application of Oxygen-Releasing Material to Enhance &lt;i&gt;In Situ &lt;/i&gt;Aerobic Bioremediation

Contamination of groundwater by petroleum-hydrocarbons is a widespread environmental problem. Generally in plumes of petroleum-hydrocarbon contamination, the dissolved oxygen (DO) demand imposed by biodegradation of organic contaminants exceeds the DO available creating anaerobic conditions within the plume core and mid-plume areas. The objectives of this bench-scale study were to (1) develop oxygen-releasing materials for continuous oxygen supplement, (2) determine the optimal components of the studied oxygen release material, and (3) evaluate the oxygen release rate and lifetime of this material. Moreover, the potential of using a passive oxygen release material to clean up aquifers contaminated by petroleum hydrocarbons was also studied. Bench experiments were conducted to design and identify the components of the oxygen-releasing materials. The mixtures of the oxygen release material were prepared by blending gypsum, calcium peroxide (CaO2), sand, and water together at a ratio of 1：0.5：0.14：0.75 by weight. Cement was used as a binder and regular medium filter sand was used to increase the permeability of the mixture. Calcium peroxide releases oxygen upon contact water (2CaO2 + 2H2O → O2 + 2Ca(OH) 2). The designed material with a density of 1.1 g/cm3 was made of 3.5-cm cube for the batch experiment. Results show that the oxygen release rate of the material is 0.025 mg/day/g. The oxygen release material is able to remain active in oxygen release for more than three months. With the application of this developed oxygen release material, the contaminated subsurface can remain an aerobic environment for subsequent aerobic bioremediation. For the future field application, the developed materials can be placed in remediation wells, trenches, horizontal wells, or barriers. Thus, the passive biobarrier system has advantages over conventional system including less maintenance, cost-effectiveness, no above-ground facilities, no groundwater pumping and reinjection, no air pollution problems, and groundwater remediation in situ. The proposed treatment system would be expected to provide a more cost-effective alternative to remediate petroleum-hydrocarbon contaminated aquifers. This technology can also be applied for other hazardous waste contaminated sites.

Testing and Modeling of Granular Medium Filters to Decrease Capital, Operational, and Maintenance Requirements and Comply with Effluent Requirements

Testing and Modeling of Granular Medium Filters to Decrease Capital, Operational, and Maintenance Requirements and Comply with Effluent RequirementsMethods of determining the optimum granular filter medium properties are discussed in this paper. Optimized design of granular medium filtration systems result in significant capital and operational savings while achieving the desired effluent quality. Filter design criteria are optimized utilizing a granular medium depth filtration model and results obtained from pilot studies or similar plants.Author(s)Onder CaliskanerKapil VermaGeorge TchobanoglousSourceProceedings of the Water Environment FederationDocument typeConference PaperPublisherWater Environment FederationPrint publication date Sep, 2012ISSN1938-6478DOI10.2175/193864712811703982Volume / Issue2012 / 7Content sourceWEFTECCopyright2012Word count74

Formaldehyde Removal Efficiency Using Nano-size Carbon Colloids

The purpose of this study was to assess the removal efficiency of formaldehyde using nano-size carbon colloid (NCC), which was produced by a comparatively easy and cheap method. In this study, nano-size carbon colloid based on water was produced by an electro-chemical method. The particles which have mostly a spherical shape with a diameter of, what is called, “nano-size” were produced. Non-woven fabric filter, which is currently on the market as a medium filter, was used for the removal efficiency test. Known concentration (0.5 ppm) of formaldehyde standard gas was used as a pollutant. The overall results indicate that: (1) nano-size carbon colloid which has a stable dispersibility, and of which diameter is approximately 10 nm or less was produced; (2) filters treated with nano-size carbon colloids showed a higher removal efficiency, 44.47 µg of HCHO removed/g of carbon and 19.28 µg of HCHO removed/g of carbon when compared to the control experiment using a normal carbon filter. The normal carbon filter system could only achieve 1.45 µg of HCHO removed/g of carbon.

Development of Ultrasonic Automatic Testing System for Flaws of Rotary Parts

In order to conquer the disadvantages of undetection, misjudgment and low-efficiency in ultrasonic A-scan testing for rotary parts, an ultrasonic automatic imaging system was developed, and automatic scan device was specially designed for rotary parts. Moreover, the testing software was programmed by LabWindows/CVI, which achieves the acquisition and processing of ultrasonic signals, and displays A, B, C, D and P-scan image. On the basis of storing A-scan data and transforming non-isotropic resolution B-scan image into isotropic one, P-scan imaging is realized. Medium filtering was applied to A-scan signal and C-scan image and the Signal-to-Noise is improved. The experimental results show that this system has well achieved numeralization, automatization and imaging of ultrasonic testing.

PHASE NOISE FILTERINGS IN INSAR INTERFEROGRAM

There exist a lot of phase noises in interferogram, which will adversely affect the product precision of interferometric synthetic aperture radar (INSAR). It is therefore very important to reduce the phase noise before phase unwrapping. In this paper, the authors deal with four noise filtering methods, namely multi-look processing, medium filtering, gradient-based adaptive filtering and additive filtering. In practice, the combination of these filtering methods would yield even better result.

DETECTION OF BROWN DWARF LIKE OBJECTS IN THE CORE OF NGC 3603

We use near-infrared data obtained with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope to identify objects having the colors of brown dwarfs (BDs) in the field of the massive galactic cluster NGC 3603. These are identified through use of a combination of narrow and medium band filters spanning the J and H bands, and which are particularly sensitive to the presence of the 1.3-1.5{\mu}m H2O molecular band - unique to BDs. We provide a calibration of the relationship between effective temperature and color for both field stars and for BDs. This photometric method provides effective temperatures for BDs to an accuracy of {\pm}350K relative to spectroscopic techniques. This accuracy is shown to be not significantly affected by either stellar surface gravity or uncertainties in the interstellar extinction. We identify nine objects having effective temperature between 1700 and 2200 K, typical of BDs, observed J-band magnitudes in the range 19.5-21.5, and that are strongly clustered towards the luminous core of NGC 3603. However, if these are located at the distance of the cluster, they are far too luminous to be normal BDs. We argue that it is unlikely that these objects are either artifacts of our dataset, normal field BDs/M-type giants or extra-galactic contaminants and, therefore, might represent a new class of stars having the effective temperatures of BDs but with luminosities of more massive stars. We explore the interesting scenario in which these objects would be normal stars that have recently tidally ingested a Hot Jupiter, the remnants of which are providing a short-lived extended photosphere to the central star. In this case, we would expect them to show the signature of fast rotation.

Organogenesis and encapsulation of in vitro-derived propagules of Carrizo citrange [Citrus sinensis (L.) Osb. × Poncirius trifoliata (L.) Raf

Due to widespread polyembryony, Citrus rootstocks are usually propagated by open-pollinated seed germination, although micropropagation offers many advantages. Encapsulation technology has recently attracted the interest of researchers in the field of plant propagation because it combines the advantages of zygotic or gamic seeds with those of micropropagation. In this study, we examined the encapsulation of Carrizo citrange uninodal microcuttings (3–4 mm long) and evaluated the influence of the calcium alginate coating, a short time storage at cold temperature, and different sowing substrates on the viability and regrowth of the explants. A secondary aim was to develop an efficient protocol to induce root formation in the microcuttings. The results showed that encapsulation did not negatively affect the viability, providing a satisfactory regrowth, and storage potential for 30 days at low temperature. No differences in viability and regrowth were detected between the two different sowing substrates tested (agar-solidified medium and paper filter). To optimize the production of microcuttings required to perform the encapsulation experiments, in a preliminary experiment we assessed different factors affecting the in vitro shoot regeneration from epicotyl segments (obtained from seeds of Carrizo citrange germinated in vitro), including the influence of in vitro organogenesis, explant orientation, cut surface contact with the medium, treatments with different growth regulators, and distance of the organogenic explants from the cotyledonary node. The highest organogenic response was obtained from segments horizontally cultured (particularly from the basal portion), from segments with the cut surface in contact with the medium and from explants cultured on medium supplemented with 6-benzyladenine. No significant difference in regeneration efficiency was found in response to the distance of the epicotyl portions from the cotyledonary node.

Quantitative relation between "defects" distribution on optics and near-field quality in high power solid-state laser system

Based on beam propagation theory, the quantitative relation between PSD (power spectral density) of "defects" distribution on optics and that of near field intensity was studied. Its validity was discussed on linear medium, nonlinear medium and spatial filter. The results show that PSD of "defects" distribution on optics and PSD of near field intensity are connected by a system propagation factor when the modulation is weak, which is determined by system architecture and operation state. These results provide a theoretical basis for specifications of "defects" distribution on optics, and also a guidance to enhancing the power of high power solid-state laser system.

Impact of smoking on the frequencies of micronuclei and other nuclear abnormalities in exfoliated oral cells: a comparative study with different cigarette types

The primary aim of the study was to investigate the impact of tar and nicotine contents of cigarettes on chromosomal damage in oral mucosa cells of smokers. We monitored the effect of smoking different cigarette types (i.e., of ultralight filter, light filter, medium filter and unfiltered cigarettes) on induction of nuclear anomalies including micronuclei (MN), broken eggs (BE), binucleates (BN), condensed chromatin (CC), karyorrhexis (KR), karyolysis (KL) and pyknosis (P) in exfoliated buccal cells. The cells were collected from 83 healthy heavy smokers (n=15-25/group) consuming a similar number of cigarettes (26-33) per day and from never smokers as controls (n=20). The frequencies of KR, CC, KL, BE and BN were increased significantly only in smokers of medium (MF) and non-filtered (NF) types of cigarettes while MN levels were only elevated (p < 0.0001) in the group that smoked NF cigarettes. Since BN and BE were increased (p < 00001) as a consequence of exposure to lower levels of toxic constituents in tobacco, it suggests that these endpoints, which both reflect DNA damage, are more sensitive than MN, which is the only parameter scored in most earlier studies. The induction of MN, BN, KR and KL increased significantly with daily tar exposure and decreased simultaneously with daily nicotine uptake (in all cases, P was < 0.0001). These findings also suggest that nicotine potentially protects cells against DNA reactive carcinogens contained in tobacco smoke although earlier in vitro and animal studies showed that the alkaloid induces DNA damage per se. A significant inverse correlation between the frequencies of endpoints such as cells with MN (- 1.56), MN (-1.69), BN (-1.36), KR (-1.10) and KL (-1.87) with the nicotine levels in cigarettes was found. However, this observation requires further verification by a controlled intervention study. In case it can be substantiated it will have an impact on the ongoing discussion of the health risks associated with nicotine replacement therapy.

Bank of Canada Communication, Media Coverage, and Financial Market Reactions

In the literature, central bank communication is identified via either (i) the written content of original communications or (ii) newswire reports. We examine how (i) Bank of Canada communications and (ii) media reporting on them impacts Canadian bond and stock market returns using a GARCH model over the period 1998–2006. Official communications exert a relatively larger influence on the bond market, whereas media coverage is more relevant for the stock market. In general, media filtering does not appear to play a prominent role.

A Perceptually Tuned Watermarking Scheme for Color Images

Transparency and robustness are two conflicting requirements demanded by digital image watermarking for copyright protection and many other purposes. A feasible way to simultaneously satisfy the two conflicting requirements is to embed high-strength watermark signals in the host signals that can accommodate the distortion due to watermark insertion as part of perceptual redundancy. The search of distortion-tolerable host signals for watermark insertion and the determination of watermark strength are hence crucial to the realization of a transparent yet robust watermark. This paper presents a color image watermarking scheme that hides watermark signals in most distortion-tolerable signals within three color channels of the host image without resulting in perceivable distortion. The distortion-tolerable host signals or the signals that possess high perceptual redundancy are sought in the wavelet domain for watermark insertion. A visual model based on the CIEDE2000 color difference equation is used to measure the perceptual redundancy inherent in each wavelet coefficient of the host image. By means of quantization index modulation, binary watermark signals are embedded in qualified wavelet coefficients. To reinforce the robustness, the watermark signals are repeated and permuted before embedding, and restored by the majority-vote decision making process in watermark extraction. Original images are not required in watermark extraction. Only a small amount of information including locations of qualified coefficients and the data associated with coefficient quantization is needed for watermark extraction. Experimental results show that the embedded watermark is transparent and quite robust in face of various attacks such as cropping, low-pass filtering, scaling, media filtering, white-noise addition as well as the JPEG and JPEG2000 coding at high compression ratios.

Cultures of human tracheal gland cells of mucous or serous phenotype

There are two main epithelial cell types in the secretory tubules of mammalian glands: serous and mucous. The former is believed to secrete predominantly water and antimicrobials, the latter mucins. Primary cultures of human airway gland epithelium have been available for almost 20 yr, but they are poorly differentiated and lack clear features of either serous or mucous cells. In this study, by varying growth supports and media, we have produced cultures from human airway glands that in terms of their ultrastructure and secretory products resemble either mucous or serous cells. Of four types of porous-bottomed insert tested, polycarbonate filters (Transwells) most strongly promoted the mucous phenotype. Coupled with the addition of epidermal growth factor (EGF), this growth support produced “mucous” cells that contained the large electron-lucent granules characteristic of native mucous cells, but lacked the small electron-dense granules characteristic of serous cells. Furthermore, they showed high levels of mucin secretion and low levels of release of lactoferrin and lysozyme (markers of native serous cells). By contrast, growth on polyethylene terephthalate filters (Cyclopore) in medium lacking EGF produced “serous” cells in which small electron-dense granules replaced the electron-lucent ones, and the cells had high levels of lactoferrin and lysozyme but low levels of mucins. Measurements of transepithelial resistance and short-circuit current showed that both “serous” and “mucous” cell cultures possessed tight junctions, had become polarized, and were actively secreting Cl.

In-line flocculation–filtration as pre-treatment to reverse osmosis desalination

In this paper the performance of single and dual media filters with in-line flocculation have been examined as pretreatment to seawater reverse osmosis (SWRO). A comparison of filter performance was made between single medium filter (80 cm) consisting of sand or anthracite, and dual media filter consisting of sand (40 cm at the bottom) and anthracite (40 cm on top). Short term (6 hours) experiments were conducted with in-line coagulation followed by direct filtration. Filtration velocities of 5 m/h and 10 m/h were used. The performances of these filters were assessed in terms of turbidity removal, head loss build-up, and organic compound removal in terms of molecular weight distribution (MWD). The efficiency of the filter as pretreatment was evaluated in terms of silt density index (SDI) and modified fouling index (MFI). It was found that the turbidity removal was high and all the filters produced more or less same quality water. There was a slower buildup of head loss for coarser filter medium. A post treatment of reverse osmosis after an inline-flocculation-dual media filtration showed lower normalized flux decline ( J/ J 0) (0.35 to 0.22 during the first 20 hours operation) while, seawater without any pretreatment showed steeper flux decline (0.18 to 0.11 at first 20 hours operation) in RO.